X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/222d54dc209210b6e43589c798e35e21273b4082..88ea89339783ee587180b645981967f6cb8bcd20:/ssh.c diff --git a/ssh.c b/ssh.c index 33da9930..a3255a85 100644 --- a/ssh.c +++ b/ssh.c @@ -1,11 +1,21 @@ +/* + * SSH backend. + */ + #include #include #include #include +#include +#include #include "putty.h" #include "tree234.h" #include "ssh.h" +#ifndef NO_GSSAPI +#include "sshgssc.h" +#include "sshgss.h" +#endif #ifndef FALSE #define FALSE 0 @@ -56,6 +66,10 @@ #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ +#define SSH1_AUTH_RHOSTS 1 /* 0x1 */ +#define SSH1_AUTH_RSA 2 /* 0x2 */ +#define SSH1_AUTH_PASSWORD 3 /* 0x3 */ +#define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */ #define SSH1_AUTH_TIS 5 /* 0x5 */ #define SSH1_AUTH_CCARD 16 /* 0x10 */ @@ -77,6 +91,9 @@ #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ +#define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */ +#define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */ +#define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */ #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ @@ -99,17 +116,30 @@ #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ +#define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60 +#define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61 +#define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63 +#define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64 +#define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65 +#define SSH2_MSG_USERAUTH_GSSAPI_MIC 66 /* * Packet type contexts, so that ssh2_pkt_type can correctly decode * the ambiguous type numbers back into the correct type strings. */ -#define SSH2_PKTCTX_DHGROUP1 0x0001 -#define SSH2_PKTCTX_DHGEX 0x0002 -#define SSH2_PKTCTX_PUBLICKEY 0x0010 -#define SSH2_PKTCTX_PASSWORD 0x0020 -#define SSH2_PKTCTX_KBDINTER 0x0040 -#define SSH2_PKTCTX_AUTH_MASK 0x00F0 +typedef enum { + SSH2_PKTCTX_NOKEX, + SSH2_PKTCTX_DHGROUP, + SSH2_PKTCTX_DHGEX, + SSH2_PKTCTX_RSAKEX +} Pkt_KCtx; +typedef enum { + SSH2_PKTCTX_NOAUTH, + SSH2_PKTCTX_PUBLICKEY, + SSH2_PKTCTX_PASSWORD, + SSH2_PKTCTX_GSSAPI, + SSH2_PKTCTX_KBDINTER +} Pkt_ACtx; #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ @@ -129,21 +159,21 @@ static const char *const ssh2_disconnect_reasons[] = { NULL, - "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT", - "SSH_DISCONNECT_PROTOCOL_ERROR", - "SSH_DISCONNECT_KEY_EXCHANGE_FAILED", - "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED", - "SSH_DISCONNECT_MAC_ERROR", - "SSH_DISCONNECT_COMPRESSION_ERROR", - "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE", - "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED", - "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE", - "SSH_DISCONNECT_CONNECTION_LOST", - "SSH_DISCONNECT_BY_APPLICATION", - "SSH_DISCONNECT_TOO_MANY_CONNECTIONS", - "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER", - "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE", - "SSH_DISCONNECT_ILLEGAL_USER_NAME", + "host not allowed to connect", + "protocol error", + "key exchange failed", + "host authentication failed", + "MAC error", + "compression error", + "service not available", + "protocol version not supported", + "host key not verifiable", + "connection lost", + "by application", + "too many connections", + "auth cancelled by user", + "no more auth methods available", + "illegal user name", }; #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ @@ -162,11 +192,119 @@ static const char *const ssh2_disconnect_reasons[] = { #define BUG_CHOKES_ON_RSA 8 #define BUG_SSH2_RSA_PADDING 16 #define BUG_SSH2_DERIVEKEY 32 -#define BUG_SSH2_DH_GEX 64 +#define BUG_SSH2_REKEY 64 #define BUG_SSH2_PK_SESSIONID 128 +#define BUG_SSH2_MAXPKT 256 +#define BUG_CHOKES_ON_SSH2_IGNORE 512 +#define BUG_CHOKES_ON_WINADJ 1024 + +/* + * Codes for terminal modes. + * Most of these are the same in SSH-1 and SSH-2. + * This list is derived from RFC 4254 and + * SSH-1 RFC-1.2.31. + */ +static const struct { + const char* const mode; + int opcode; + enum { TTY_OP_CHAR, TTY_OP_BOOL } type; +} ssh_ttymodes[] = { + /* "V" prefix discarded for special characters relative to SSH specs */ + { "INTR", 1, TTY_OP_CHAR }, + { "QUIT", 2, TTY_OP_CHAR }, + { "ERASE", 3, TTY_OP_CHAR }, + { "KILL", 4, TTY_OP_CHAR }, + { "EOF", 5, TTY_OP_CHAR }, + { "EOL", 6, TTY_OP_CHAR }, + { "EOL2", 7, TTY_OP_CHAR }, + { "START", 8, TTY_OP_CHAR }, + { "STOP", 9, TTY_OP_CHAR }, + { "SUSP", 10, TTY_OP_CHAR }, + { "DSUSP", 11, TTY_OP_CHAR }, + { "REPRINT", 12, TTY_OP_CHAR }, + { "WERASE", 13, TTY_OP_CHAR }, + { "LNEXT", 14, TTY_OP_CHAR }, + { "FLUSH", 15, TTY_OP_CHAR }, + { "SWTCH", 16, TTY_OP_CHAR }, + { "STATUS", 17, TTY_OP_CHAR }, + { "DISCARD", 18, TTY_OP_CHAR }, + { "IGNPAR", 30, TTY_OP_BOOL }, + { "PARMRK", 31, TTY_OP_BOOL }, + { "INPCK", 32, TTY_OP_BOOL }, + { "ISTRIP", 33, TTY_OP_BOOL }, + { "INLCR", 34, TTY_OP_BOOL }, + { "IGNCR", 35, TTY_OP_BOOL }, + { "ICRNL", 36, TTY_OP_BOOL }, + { "IUCLC", 37, TTY_OP_BOOL }, + { "IXON", 38, TTY_OP_BOOL }, + { "IXANY", 39, TTY_OP_BOOL }, + { "IXOFF", 40, TTY_OP_BOOL }, + { "IMAXBEL", 41, TTY_OP_BOOL }, + { "ISIG", 50, TTY_OP_BOOL }, + { "ICANON", 51, TTY_OP_BOOL }, + { "XCASE", 52, TTY_OP_BOOL }, + { "ECHO", 53, TTY_OP_BOOL }, + { "ECHOE", 54, TTY_OP_BOOL }, + { "ECHOK", 55, TTY_OP_BOOL }, + { "ECHONL", 56, TTY_OP_BOOL }, + { "NOFLSH", 57, TTY_OP_BOOL }, + { "TOSTOP", 58, TTY_OP_BOOL }, + { "IEXTEN", 59, TTY_OP_BOOL }, + { "ECHOCTL", 60, TTY_OP_BOOL }, + { "ECHOKE", 61, TTY_OP_BOOL }, + { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */ + { "OPOST", 70, TTY_OP_BOOL }, + { "OLCUC", 71, TTY_OP_BOOL }, + { "ONLCR", 72, TTY_OP_BOOL }, + { "OCRNL", 73, TTY_OP_BOOL }, + { "ONOCR", 74, TTY_OP_BOOL }, + { "ONLRET", 75, TTY_OP_BOOL }, + { "CS7", 90, TTY_OP_BOOL }, + { "CS8", 91, TTY_OP_BOOL }, + { "PARENB", 92, TTY_OP_BOOL }, + { "PARODD", 93, TTY_OP_BOOL } +}; + +/* Miscellaneous other tty-related constants. */ +#define SSH_TTY_OP_END 0 +/* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */ +#define SSH1_TTY_OP_ISPEED 192 +#define SSH1_TTY_OP_OSPEED 193 +#define SSH2_TTY_OP_ISPEED 128 +#define SSH2_TTY_OP_OSPEED 129 + +/* Helper functions for parsing tty-related config. */ +static unsigned int ssh_tty_parse_specchar(char *s) +{ + unsigned int ret; + if (*s) { + char *next = NULL; + ret = ctrlparse(s, &next); + if (!next) ret = s[0]; + } else { + ret = 255; /* special value meaning "don't set" */ + } + return ret; +} +static unsigned int ssh_tty_parse_boolean(char *s) +{ + if (stricmp(s, "yes") == 0 || + stricmp(s, "on") == 0 || + stricmp(s, "true") == 0 || + stricmp(s, "+") == 0) + return 1; /* true */ + else if (stricmp(s, "no") == 0 || + stricmp(s, "off") == 0 || + stricmp(s, "false") == 0 || + stricmp(s, "-") == 0) + return 0; /* false */ + else + return (atoi(s) != 0); +} #define translate(x) if (type == x) return #x -#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x +#define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x +#define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x static char *ssh1_pkt_type(int type) { translate(SSH1_MSG_DISCONNECT); @@ -212,8 +350,14 @@ static char *ssh1_pkt_type(int type) translate(SSH1_CMSG_AUTH_CCARD_RESPONSE); return "unknown"; } -static char *ssh2_pkt_type(int pkt_ctx, int type) +static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type) { + translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI); translate(SSH2_MSG_DISCONNECT); translate(SSH2_MSG_IGNORE); translate(SSH2_MSG_UNIMPLEMENTED); @@ -222,20 +366,23 @@ static char *ssh2_pkt_type(int pkt_ctx, int type) translate(SSH2_MSG_SERVICE_ACCEPT); translate(SSH2_MSG_KEXINIT); translate(SSH2_MSG_NEWKEYS); - translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1); - translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1); - translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); - translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); - translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); - translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); + translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP); + translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP); + translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); + translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); + translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); + translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); + translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX); + translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX); + translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX); translate(SSH2_MSG_USERAUTH_REQUEST); translate(SSH2_MSG_USERAUTH_FAILURE); translate(SSH2_MSG_USERAUTH_SUCCESS); translate(SSH2_MSG_USERAUTH_BANNER); - translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); - translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); - translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); - translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER); + translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); + translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); + translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); + translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER); translate(SSH2_MSG_GLOBAL_REQUEST); translate(SSH2_MSG_REQUEST_SUCCESS); translate(SSH2_MSG_REQUEST_FAILURE); @@ -255,19 +402,13 @@ static char *ssh2_pkt_type(int pkt_ctx, int type) #undef translate #undef translatec -#define GET_32BIT(cp) \ - (((unsigned long)(unsigned char)(cp)[0] << 24) | \ - ((unsigned long)(unsigned char)(cp)[1] << 16) | \ - ((unsigned long)(unsigned char)(cp)[2] << 8) | \ - ((unsigned long)(unsigned char)(cp)[3])) - -#define PUT_32BIT(cp, value) { \ - (cp)[0] = (unsigned char)((value) >> 24); \ - (cp)[1] = (unsigned char)((value) >> 16); \ - (cp)[2] = (unsigned char)((value) >> 8); \ - (cp)[3] = (unsigned char)(value); } - -enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; +/* Enumeration values for fields in SSH-1 packets */ +enum { + PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM, + /* These values are for communicating relevant semantics of + * fields to the packet logging code. */ + PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA +}; /* * Coroutine mechanics for the sillier bits of the code. If these @@ -290,12 +431,16 @@ enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; * Database for Edit and Continue'. */ #define crBegin(v) { int *crLine = &v; switch(v) { case 0:; -#define crState(t) \ - struct t *s; \ - if (!ssh->t) ssh->t = snew(struct t); \ - s = ssh->t; +#define crBeginState crBegin(s->crLine) +#define crStateP(t, v) \ + struct t *s; \ + if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \ + s = (v); +#define crState(t) crStateP(t, ssh->t) #define crFinish(z) } *crLine = 0; return (z); } #define crFinishV } *crLine = 0; return; } +#define crFinishFree(z) } sfree(s); return (z); } +#define crFinishFreeV } sfree(s); return; } #define crReturn(z) \ do {\ *crLine =__LINE__; return (z); case __LINE__:;\ @@ -310,20 +455,31 @@ enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; #define crWaitUntilV(c) do { crReturnV; } while (!(c)) typedef struct ssh_tag *Ssh; - -static void ssh2_pkt_init(Ssh, int pkt_type); -static void ssh2_pkt_addbool(Ssh, unsigned char value); -static void ssh2_pkt_adduint32(Ssh, unsigned long value); -static void ssh2_pkt_addstring_start(Ssh); -static void ssh2_pkt_addstring_str(Ssh, char *data); -static void ssh2_pkt_addstring_data(Ssh, char *data, int len); -static void ssh2_pkt_addstring(Ssh, char *data); +struct Packet; + +static struct Packet *ssh1_pkt_init(int pkt_type); +static struct Packet *ssh2_pkt_init(int pkt_type); +static void ssh_pkt_ensure(struct Packet *, int length); +static void ssh_pkt_adddata(struct Packet *, void *data, int len); +static void ssh_pkt_addbyte(struct Packet *, unsigned char value); +static void ssh2_pkt_addbool(struct Packet *, unsigned char value); +static void ssh_pkt_adduint32(struct Packet *, unsigned long value); +static void ssh_pkt_addstring_start(struct Packet *); +static void ssh_pkt_addstring_str(struct Packet *, char *data); +static void ssh_pkt_addstring_data(struct Packet *, char *data, int len); +static void ssh_pkt_addstring(struct Packet *, char *data); static unsigned char *ssh2_mpint_fmt(Bignum b, int *len); -static void ssh2_pkt_addmp(Ssh, Bignum b); -static int ssh2_pkt_construct(Ssh); -static void ssh2_pkt_send(Ssh); -static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt); -static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt); +static void ssh1_pkt_addmp(struct Packet *, Bignum b); +static void ssh2_pkt_addmp(struct Packet *, Bignum b); +static int ssh2_pkt_construct(Ssh, struct Packet *); +static void ssh2_pkt_send(Ssh, struct Packet *); +static void ssh2_pkt_send_noqueue(Ssh, struct Packet *); +static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin); +static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin); +static void ssh2_channel_check_close(struct ssh_channel *c); +static void ssh_channel_destroy(struct ssh_channel *c); /* * Buffer management constants. There are several of these for @@ -331,60 +487,48 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt); * * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up * on a local data stream before we throttle the whole SSH - * connection (in SSH1 only). Throttling the whole connection is + * connection (in SSH-1 only). Throttling the whole connection is * pretty drastic so we set this high in the hope it won't * happen very often. * * - SSH_MAX_BACKLOG is the amount of backlog that must build up * on the SSH connection itself before we defensively throttle * _all_ local data streams. This is pretty drastic too (though - * thankfully unlikely in SSH2 since the window mechanism should + * thankfully unlikely in SSH-2 since the window mechanism should * ensure that the server never has any need to throttle its end * of the connection), so we set this high as well. * - * - OUR_V2_WINSIZE is the maximum window size we present on SSH2 + * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2 * channels. + * + * - OUR_V2_BIGWIN is the window size we advertise for the only + * channel in a simple connection. It must be <= INT_MAX. + * + * - OUR_V2_MAXPKT is the official "maximum packet size" we send + * to the remote side. This actually has nothing to do with the + * size of the _packet_, but is instead a limit on the amount + * of data we're willing to receive in a single SSH2 channel + * data message. + * + * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH + * _packet_ we're prepared to cope with. It must be a multiple + * of the cipher block size, and must be at least 35000. */ #define SSH1_BUFFER_LIMIT 32768 #define SSH_MAX_BACKLOG 32768 #define OUR_V2_WINSIZE 16384 - -const static struct ssh_kex *kex_algs[] = { - &ssh_diffiehellman_gex, - &ssh_diffiehellman -}; +#define OUR_V2_BIGWIN 0x7fffffff +#define OUR_V2_MAXPKT 0x4000UL +#define OUR_V2_PACKETLIMIT 0x9000UL const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; -static void *nullmac_make_context(void) -{ - return NULL; -} -static void nullmac_free_context(void *handle) -{ -} -static void nullmac_key(void *handle, unsigned char *key) -{ -} -static void nullmac_generate(void *handle, unsigned char *blk, int len, - unsigned long seq) -{ -} -static int nullmac_verify(void *handle, unsigned char *blk, int len, - unsigned long seq) -{ - return 1; -} -const static struct ssh_mac ssh_mac_none = { - nullmac_make_context, nullmac_free_context, nullmac_key, - nullmac_generate, nullmac_verify, "none", 0 -}; const static struct ssh_mac *macs[] = { - &ssh_sha1, &ssh_md5, &ssh_mac_none + &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5 }; const static struct ssh_mac *buggymacs[] = { - &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none + &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5 }; static void *ssh_comp_none_init(void) @@ -404,7 +548,7 @@ static int ssh_comp_none_disable(void *handle) return 0; } const static struct ssh_compress ssh_comp_none = { - "none", + "none", NULL, ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, ssh_comp_none_disable, NULL @@ -419,7 +563,29 @@ enum { /* channel types */ CHAN_X11, CHAN_AGENT, CHAN_SOCKDATA, - CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */ + CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */ + /* + * CHAN_ZOMBIE is used to indicate a channel for which we've + * already destroyed the local data source: for instance, if a + * forwarded port experiences a socket error on the local side, we + * immediately destroy its local socket and turn the SSH channel + * into CHAN_ZOMBIE. + */ + CHAN_ZOMBIE +}; + +typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin); +typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx); +typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *); + +/* + * Each channel has a queue of outstanding CHANNEL_REQUESTS and their + * handlers. + */ +struct outstanding_channel_request { + cchandler_fn_t handler; + void *ctx; + struct outstanding_channel_request *next; }; /* @@ -429,8 +595,10 @@ struct ssh_channel { Ssh ssh; /* pointer back to main context */ unsigned remoteid, localid; int type; + /* True if we opened this channel but server hasn't confirmed. */ + int halfopen; /* - * In SSH1, this value contains four bits: + * In SSH-1, this value contains four bits: * * 1 We have sent SSH1_MSG_CHANNEL_CLOSE. * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. @@ -438,23 +606,67 @@ struct ssh_channel { * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. * * A channel is completely finished with when all four bits are set. + * + * In SSH-2, the four bits mean: + * + * 1 We have sent SSH2_MSG_CHANNEL_EOF. + * 2 We have sent SSH2_MSG_CHANNEL_CLOSE. + * 4 We have received SSH2_MSG_CHANNEL_EOF. + * 8 We have received SSH2_MSG_CHANNEL_CLOSE. + * + * A channel is completely finished with when we have both sent + * and received CLOSE. + * + * The symbolic constants below use the SSH-2 terminology, which + * is a bit confusing in SSH-1, but we have to use _something_. */ +#define CLOSES_SENT_EOF 1 +#define CLOSES_SENT_CLOSE 2 +#define CLOSES_RCVD_EOF 4 +#define CLOSES_RCVD_CLOSE 8 int closes; + + /* + * This flag indicates that an EOF is pending on the outgoing side + * of the channel: that is, wherever we're getting the data for + * this channel has sent us some data followed by EOF. We can't + * actually send the EOF until we've finished sending the data, so + * we set this flag instead to remind us to do so once our buffer + * is clear. + */ + int pending_eof; + + /* + * True if this channel is causing the underlying connection to be + * throttled. + */ + int throttling_conn; union { - struct ssh1_data_channel { - int throttling; - } v1; struct ssh2_data_channel { bufchain outbuffer; unsigned remwindow, remmaxpkt; - unsigned locwindow; + /* locwindow is signed so we can cope with excess data. */ + int locwindow, locmaxwin; + /* + * remlocwin is the amount of local window that we think + * the remote end had available to it after it sent the + * last data packet or window adjust ack. + */ + int remlocwin; + /* + * These store the list of channel requests that haven't + * been acked. + */ + struct outstanding_channel_request *chanreq_head, *chanreq_tail; + enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state; } v2; } v; union { struct ssh_agent_channel { unsigned char *message; unsigned char msglen[4]; - int lensofar, totallen; + unsigned lensofar, totallen; + int outstanding_requests; } a; struct ssh_x11_channel { Socket s; @@ -466,11 +678,11 @@ struct ssh_channel { }; /* - * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH - * 2 use this structure in different ways, reflecting SSH 2's + * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2 + * use this structure in different ways, reflecting SSH-2's * altogether saner approach to port forwarding. * - * In SSH 1, you arrange a remote forwarding by sending the server + * In SSH-1, you arrange a remote forwarding by sending the server * the remote port number, and the local destination host:port. * When a connection comes in, the server sends you back that * host:port pair, and you connect to it. This is a ready-made @@ -482,42 +694,88 @@ struct ssh_channel { * host:port pairs we _are_ trying to forward to, and reject a * connection request from the server if it's not in the list. * - * In SSH 2, each side of the connection minds its own business and + * In SSH-2, each side of the connection minds its own business and * doesn't send unnecessary information to the other. You arrange a * remote forwarding by sending the server just the remote port * number. When a connection comes in, the server tells you which * of its ports was connected to; and _you_ have to remember what * local host:port pair went with that port number. * - * Hence: in SSH 1 this structure stores host:port pairs we intend - * to allow connections to, and is indexed by those host:port - * pairs. In SSH 2 it stores a mapping from source port to - * destination host:port pair, and is indexed by source port. + * Hence, in SSH-1 this structure is indexed by destination + * host:port pair, whereas in SSH-2 it is indexed by source port. */ +struct ssh_portfwd; /* forward declaration */ + struct ssh_rportfwd { unsigned sport, dport; char dhost[256]; + char *sportdesc; + struct ssh_portfwd *pfrec; }; +#define free_rportfwd(pf) ( \ + ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) ) -struct Packet { - long length; +/* + * Separately to the rportfwd tree (which is for looking up port + * open requests from the server), a tree of _these_ structures is + * used to keep track of all the currently open port forwardings, + * so that we can reconfigure in mid-session if the user requests + * it. + */ +struct ssh_portfwd { + enum { DESTROY, KEEP, CREATE } status; int type; - unsigned char *data; - unsigned char *body; - long savedpos; - long maxlen; + unsigned sport, dport; + char *saddr, *daddr; + char *sserv, *dserv; + struct ssh_rportfwd *remote; + int addressfamily; + void *local; +}; +#define free_portfwd(pf) ( \ + ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \ + sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) ) + +struct Packet { + long length; /* length of `data' actually used */ + long forcepad; /* SSH-2: force padding to at least this length */ + int type; /* only used for incoming packets */ + unsigned long sequence; /* SSH-2 incoming sequence number */ + unsigned char *data; /* allocated storage */ + unsigned char *body; /* offset of payload within `data' */ + long savedpos; /* temporary index into `data' (for strings) */ + long maxlen; /* amount of storage allocated for `data' */ + long encrypted_len; /* for SSH-2 total-size counting */ + + /* + * State associated with packet logging + */ + int logmode; + int nblanks; + struct logblank_t *blanks; }; -static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt); -static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt); +static void ssh1_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin); +static void ssh2_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin); +static void ssh1_protocol_setup(Ssh ssh); +static void ssh2_protocol_setup(Ssh ssh); static void ssh_size(void *handle, int width, int height); static void ssh_special(void *handle, Telnet_Special); static int ssh2_try_send(struct ssh_channel *c); static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); static void ssh_throttle_all(Ssh ssh, int enable, int bufsize); -static void ssh2_set_window(struct ssh_channel *c, unsigned newwin); +static void ssh2_set_window(struct ssh_channel *c, int newwin); static int ssh_sendbuffer(void *handle); -static void ssh_do_close(Ssh ssh); +static int ssh_do_close(Ssh ssh, int notify_exit); +static unsigned long ssh_pkt_getuint32(struct Packet *pkt); +static int ssh2_pkt_getbool(struct Packet *pkt); +static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length); +static void ssh2_timer(void *ctx, unsigned long now); +static void do_ssh2_transport(Ssh ssh, void *vin, int inlen, + struct Packet *pktin); +static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin); struct rdpkt1_state_tag { long len, pad, biglen, to_read; @@ -525,6 +783,7 @@ struct rdpkt1_state_tag { unsigned char *p; int i; int chunk; + struct Packet *pktin; }; struct rdpkt2_state_tag { @@ -532,13 +791,23 @@ struct rdpkt2_state_tag { int i; int cipherblk; unsigned long incoming_sequence; + struct Packet *pktin; +}; + +struct queued_handler; +struct queued_handler { + int msg1, msg2; + chandler_fn_t handler; + void *ctx; + struct queued_handler *next; }; struct ssh_tag { const struct plug_function_table *fn; /* the above field _must_ be first in the structure */ - SHA_State exhash, exhashbase; + char *v_c, *v_s; + void *exhash; Socket s; @@ -563,7 +832,8 @@ struct ssh_tag { void *cs_comp_ctx, *sc_comp_ctx; const struct ssh_kex *kex; const struct ssh_signkey *hostkey; - unsigned char v2_session_id[20]; + unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN]; + int v2_session_id_len; void *kex_ctx; char *savedhost; @@ -573,13 +843,17 @@ struct ssh_tag { void *frontend; + int ospeed, ispeed; /* temporaries */ int term_width, term_height; tree234 *channels; /* indexed by local id */ struct ssh_channel *mainchan; /* primary session channel */ + int ncmode; /* is primary channel direct-tcpip? */ int exitcode; + int close_expected; + int clean_exit; - tree234 *rportfwds; + tree234 *rportfwds, *portfwds; enum { SSH_STATE_PREPACKET, @@ -590,9 +864,12 @@ struct ssh_tag { } state; int size_needed, eof_needed; + int sent_console_eof; + int got_pty; /* affects EOF behaviour on main channel */ - struct Packet pktin; - struct Packet pktout; + struct Packet **queue; + int queuelen, queuesize; + int queueing; unsigned char *deferred_send_data; int deferred_len, deferred_size; @@ -604,34 +881,24 @@ struct ssh_tag { */ int fallback_cmd; - /* - * Used for username and password input. - */ - char *userpass_input_buffer; - int userpass_input_buflen; - int userpass_input_bufpos; - int userpass_input_echo; + bufchain banner; /* accumulates banners during do_ssh2_authconn */ - char *portfwd_strptr; - int pkt_ctx; + Pkt_KCtx pkt_kctx; + Pkt_ACtx pkt_actx; - void *x11auth; + struct X11Display *x11disp; int version; - int v1_throttle_count; + int conn_throttle_count; int overall_bufsize; int throttled_all; int v1_stdout_throttling; - int v2_outgoing_sequence; + unsigned long v2_outgoing_sequence; int ssh1_rdpkt_crstate; int ssh2_rdpkt_crstate; - int do_ssh_init_crstate; int ssh_gotdata_crstate; - int ssh1_protocol_crstate; - int do_ssh1_login_crstate; - int do_ssh2_transport_crstate; - int do_ssh2_authconn_crstate; + int do_ssh1_connection_crstate; void *do_ssh_init_state; void *do_ssh1_login_state; @@ -641,22 +908,93 @@ struct ssh_tag { struct rdpkt1_state_tag rdpkt1_state; struct rdpkt2_state_tag rdpkt2_state; - void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt); - int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen); + /* SSH-1 and SSH-2 use this for different things, but both use it */ + int protocol_initial_phase_done; + + void (*protocol) (Ssh ssh, void *vin, int inlen, + struct Packet *pkt); + struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen); + + /* + * We maintain our own copy of a Conf structure here. That way, + * when we're passed a new one for reconfiguration, we can check + * the differences and potentially reconfigure port forwardings + * etc in mid-session. + */ + Conf *conf; /* - * We maintain a full _copy_ of a Config structure here, not - * merely a pointer to it. That way, when we're passed a new - * one for reconfiguration, we can check the differences and - * potentially reconfigure port forwardings etc in mid-session. + * Values cached out of conf so as to avoid the tree234 lookup + * cost every time they're used. */ - Config cfg; + int logomitdata; /* - * Used to transfer data back from async agent callbacks. + * Dynamically allocated username string created during SSH + * login. Stored in here rather than in the coroutine state so + * that it'll be reliably freed if we shut down the SSH session + * at some unexpected moment. + */ + char *username; + + /* + * Used to transfer data back from async callbacks. */ void *agent_response; int agent_response_len; + int user_response; + + /* + * The SSH connection can be set as `frozen', meaning we are + * not currently accepting incoming data from the network. This + * is slightly more serious than setting the _socket_ as + * frozen, because we may already have had data passed to us + * from the network which we need to delay processing until + * after the freeze is lifted, so we also need a bufchain to + * store that data. + */ + int frozen; + bufchain queued_incoming_data; + + /* + * Dispatch table for packet types that we may have to deal + * with at any time. + */ + handler_fn_t packet_dispatch[256]; + + /* + * Queues of one-off handler functions for success/failure + * indications from a request. + */ + struct queued_handler *qhead, *qtail; + handler_fn_t q_saved_handler1, q_saved_handler2; + + /* + * This module deals with sending keepalives. + */ + Pinger pinger; + + /* + * Track incoming and outgoing data sizes and time, for + * size-based rekeys. + */ + unsigned long incoming_data_size, outgoing_data_size, deferred_data_size; + unsigned long max_data_size; + int kex_in_progress; + unsigned long next_rekey, last_rekey; + char *deferred_rekey_reason; /* points to STATIC string; don't free */ + + /* + * Fully qualified host name, which we need if doing GSSAPI. + */ + char *fullhostname; + +#ifndef NO_GSSAPI + /* + * GSSAPI libraries for this session. + */ + struct ssh_gss_liblist *gsslibs; +#endif }; #define logevent(s) logevent(ssh->frontend, s) @@ -674,14 +1012,60 @@ static void logeventf(Ssh ssh, const char *fmt, ...) sfree(buf); } -#define bombout(msg) \ - do { \ - char *text = dupprintf msg; \ - ssh_do_close(ssh); \ - logevent(text); \ - connection_fatal(ssh->frontend, "%s", text); \ - sfree(text); \ - } while (0) +static void bomb_out(Ssh ssh, char *text) +{ + ssh_do_close(ssh, FALSE); + logevent(text); + connection_fatal(ssh->frontend, "%s", text); + sfree(text); +} + +#define bombout(msg) bomb_out(ssh, dupprintf msg) + +/* Functions to leave bits out of the SSH packet log file. */ + +static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype) +{ + if (conf_get_int(ssh->conf, CONF_logomitpass)) + pkt->logmode = blanktype; +} + +static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype) +{ + if (ssh->logomitdata) + pkt->logmode = blanktype; +} + +static void end_log_omission(Ssh ssh, struct Packet *pkt) +{ + pkt->logmode = PKTLOG_EMIT; +} + +/* Helper function for common bits of parsing ttymodes. */ +static void parse_ttymodes(Ssh ssh, + void (*do_mode)(void *data, char *mode, char *val), + void *data) +{ + char *key, *val; + + for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key); + val != NULL; + val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) { + /* + * val[0] is either 'V', indicating that an explicit value + * follows it, or 'A' indicating that we should pass the + * value through from the local environment via get_ttymode. + */ + if (val[0] == 'A') { + val = get_ttymode(ssh->frontend, key); + if (val) { + do_mode(data, key, val); + sfree(val); + } + } else + do_mode(data, key, val + 1); /* skip the 'V' */ + } +} static int ssh_channelcmp(void *av, void *bv) { @@ -730,6 +1114,51 @@ static int ssh_rportcmp_ssh2(void *av, void *bv) return 0; } +/* + * Special form of strcmp which can cope with NULL inputs. NULL is + * defined to sort before even the empty string. + */ +static int nullstrcmp(const char *a, const char *b) +{ + if (a == NULL && b == NULL) + return 0; + if (a == NULL) + return -1; + if (b == NULL) + return +1; + return strcmp(a, b); +} + +static int ssh_portcmp(void *av, void *bv) +{ + struct ssh_portfwd *a = (struct ssh_portfwd *) av; + struct ssh_portfwd *b = (struct ssh_portfwd *) bv; + int i; + if (a->type > b->type) + return +1; + if (a->type < b->type) + return -1; + if (a->addressfamily > b->addressfamily) + return +1; + if (a->addressfamily < b->addressfamily) + return -1; + if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0) + return i < 0 ? -1 : +1; + if (a->sport > b->sport) + return +1; + if (a->sport < b->sport) + return -1; + if (a->type != 'D') { + if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0) + return i < 0 ? -1 : +1; + if (a->dport > b->dport) + return +1; + if (a->dport < b->dport) + return -1; + } + return 0; +} + static int alloc_channel_id(Ssh ssh) { const unsigned CHANNEL_NUMBER_OFFSET = 256; @@ -768,27 +1197,28 @@ static int alloc_channel_id(Ssh ssh) return low + 1 + CHANNEL_NUMBER_OFFSET; } +static void c_write_stderr(int trusted, const char *buf, int len) +{ + int i; + for (i = 0; i < len; i++) + if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60))) + fputc(buf[i], stderr); +} + static void c_write(Ssh ssh, const char *buf, int len) { - if ((flags & FLAG_STDERR)) { - int i; - for (i = 0; i < len; i++) - if (buf[i] != '\r') - fputc(buf[i], stderr); - return; - } - from_backend(ssh->frontend, 1, buf, len); + if (flags & FLAG_STDERR) + c_write_stderr(1, buf, len); + else + from_backend(ssh->frontend, 1, buf, len); } static void c_write_untrusted(Ssh ssh, const char *buf, int len) { - int i; - for (i = 0; i < len; i++) { - if (buf[i] == '\n') - c_write(ssh, "\r\n", 2); - else if ((buf[i] & 0x60) || (buf[i] == '\r')) - c_write(ssh, buf + i, 1); - } + if (flags & FLAG_STDERR) + c_write_stderr(0, buf, len); + else + from_backend_untrusted(ssh->frontend, buf, len); } static void c_write_str(Ssh ssh, const char *buf) @@ -796,48 +1226,69 @@ static void c_write_str(Ssh ssh, const char *buf) c_write(ssh, buf, strlen(buf)); } +static void ssh_free_packet(struct Packet *pkt) +{ + sfree(pkt->data); + sfree(pkt); +} +static struct Packet *ssh_new_packet(void) +{ + struct Packet *pkt = snew(struct Packet); + + pkt->body = pkt->data = NULL; + pkt->maxlen = 0; + pkt->logmode = PKTLOG_EMIT; + pkt->nblanks = 0; + pkt->blanks = NULL; + + return pkt; +} + /* * Collect incoming data in the incoming packet buffer. * Decipher and verify the packet when it is completely read. * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. * Update the *data and *datalen variables. - * Return the additional nr of bytes needed, or 0 when - * a complete packet is available. + * Return a Packet structure when a packet is completed. */ -static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) +static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) { struct rdpkt1_state_tag *st = &ssh->rdpkt1_state; crBegin(ssh->ssh1_rdpkt_crstate); - next_packet: + st->pktin = ssh_new_packet(); - ssh->pktin.type = 0; - ssh->pktin.length = 0; + st->pktin->type = 0; + st->pktin->length = 0; for (st->i = st->len = 0; st->i < 4; st->i++) { while ((*datalen) == 0) - crReturn(4 - st->i); + crReturn(NULL); st->len = (st->len << 8) + **data; (*data)++, (*datalen)--; } st->pad = 8 - (st->len % 8); st->biglen = st->len + st->pad; - ssh->pktin.length = st->len - 5; + st->pktin->length = st->len - 5; - if (ssh->pktin.maxlen < st->biglen) { - ssh->pktin.maxlen = st->biglen; - ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA, - unsigned char); + if (st->biglen < 0) { + bombout(("Extremely large packet length from server suggests" + " data stream corruption")); + ssh_free_packet(st->pktin); + crStop(NULL); } + st->pktin->maxlen = st->biglen; + st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char); + st->to_read = st->biglen; - st->p = ssh->pktin.data; + st->p = st->pktin->data; while (st->to_read > 0) { st->chunk = st->to_read; while ((*datalen) == 0) - crReturn(st->to_read); + crReturn(NULL); if (st->chunk > (*datalen)) st->chunk = (*datalen); memcpy(st->p, *data, st->chunk); @@ -847,203 +1298,260 @@ static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) st->to_read -= st->chunk; } - if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data, + if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data, st->biglen, NULL)) { bombout(("Network attack (CRC compensation) detected!")); - crStop(0); + ssh_free_packet(st->pktin); + crStop(NULL); } if (ssh->cipher) - ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen); + ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen); - st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4); - st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4); + st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4); + st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4); if (st->gotcrc != st->realcrc) { bombout(("Incorrect CRC received on packet")); - crStop(0); + ssh_free_packet(st->pktin); + crStop(NULL); } - ssh->pktin.body = ssh->pktin.data + st->pad + 1; + st->pktin->body = st->pktin->data + st->pad + 1; + st->pktin->savedpos = 0; if (ssh->v1_compressing) { unsigned char *decompblk; int decomplen; if (!zlib_decompress_block(ssh->sc_comp_ctx, - ssh->pktin.body - 1, ssh->pktin.length + 1, + st->pktin->body - 1, st->pktin->length + 1, &decompblk, &decomplen)) { bombout(("Zlib decompression encountered invalid data")); - crStop(0); + ssh_free_packet(st->pktin); + crStop(NULL); } - if (ssh->pktin.maxlen < st->pad + decomplen) { - ssh->pktin.maxlen = st->pad + decomplen; - ssh->pktin.data = sresize(ssh->pktin.data, - ssh->pktin.maxlen + APIEXTRA, + if (st->pktin->maxlen < st->pad + decomplen) { + st->pktin->maxlen = st->pad + decomplen; + st->pktin->data = sresize(st->pktin->data, + st->pktin->maxlen + APIEXTRA, unsigned char); - ssh->pktin.body = ssh->pktin.data + st->pad + 1; + st->pktin->body = st->pktin->data + st->pad + 1; } - memcpy(ssh->pktin.body - 1, decompblk, decomplen); + memcpy(st->pktin->body - 1, decompblk, decomplen); sfree(decompblk); - ssh->pktin.length = decomplen - 1; + st->pktin->length = decomplen - 1; } - ssh->pktin.type = ssh->pktin.body[-1]; + st->pktin->type = st->pktin->body[-1]; - if (ssh->logctx) - log_packet(ssh->logctx, - PKT_INCOMING, ssh->pktin.type, - ssh1_pkt_type(ssh->pktin.type), - ssh->pktin.body, ssh->pktin.length); - - if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA || - ssh->pktin.type == SSH1_SMSG_STDERR_DATA || - ssh->pktin.type == SSH1_MSG_DEBUG || - ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || - ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { - long stringlen = GET_32BIT(ssh->pktin.body); - if (stringlen + 4 != ssh->pktin.length) { - bombout(("Received data packet with bogus string length")); - crStop(0); + /* + * Log incoming packet, possibly omitting sensitive fields. + */ + if (ssh->logctx) { + int nblanks = 0; + struct logblank_t blank; + if (ssh->logomitdata) { + int do_blank = FALSE, blank_prefix = 0; + /* "Session data" packets - omit the data field */ + if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) || + (st->pktin->type == SSH1_SMSG_STDERR_DATA)) { + do_blank = TRUE; blank_prefix = 4; + } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) { + do_blank = TRUE; blank_prefix = 8; + } + if (do_blank) { + blank.offset = blank_prefix; + blank.len = st->pktin->length; + blank.type = PKTLOG_OMIT; + nblanks = 1; + } } + log_packet(ssh->logctx, + PKT_INCOMING, st->pktin->type, + ssh1_pkt_type(st->pktin->type), + st->pktin->body, st->pktin->length, + nblanks, &blank, NULL); } - if (ssh->pktin.type == SSH1_MSG_DEBUG) { - /* log debug message */ - char buf[512]; - int stringlen = GET_32BIT(ssh->pktin.body); - strcpy(buf, "Remote debug message: "); - if (stringlen > 480) - stringlen = 480; - memcpy(buf + 8, ssh->pktin.body + 4, stringlen); - buf[8 + stringlen] = '\0'; - logevent(buf); - goto next_packet; - } else if (ssh->pktin.type == SSH1_MSG_IGNORE) { - /* do nothing */ - goto next_packet; - } - - if (ssh->pktin.type == SSH1_MSG_DISCONNECT) { - /* log reason code in disconnect message */ - char buf[256]; - unsigned msglen = GET_32BIT(ssh->pktin.body); - unsigned nowlen; - strcpy(buf, "Remote sent disconnect: "); - nowlen = strlen(buf); - if (msglen > sizeof(buf) - nowlen - 1) - msglen = sizeof(buf) - nowlen - 1; - memcpy(buf + nowlen, ssh->pktin.body + 4, msglen); - buf[nowlen + msglen] = '\0'; - /* logevent(buf); (this is now done within the bombout macro) */ - bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen)); - crStop(0); - } - - crFinish(0); + crFinish(st->pktin); } -static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) +static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) { struct rdpkt2_state_tag *st = &ssh->rdpkt2_state; crBegin(ssh->ssh2_rdpkt_crstate); - next_packet: - ssh->pktin.type = 0; - ssh->pktin.length = 0; + st->pktin = ssh_new_packet(); + + st->pktin->type = 0; + st->pktin->length = 0; if (ssh->sccipher) st->cipherblk = ssh->sccipher->blksize; else st->cipherblk = 8; if (st->cipherblk < 8) st->cipherblk = 8; + st->maclen = ssh->scmac ? ssh->scmac->len : 0; - if (ssh->pktin.maxlen < st->cipherblk) { - ssh->pktin.maxlen = st->cipherblk; - ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA, - unsigned char); - } + if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) && + ssh->scmac) { + /* + * When dealing with a CBC-mode cipher, we want to avoid the + * possibility of an attacker's tweaking the ciphertext stream + * so as to cause us to feed the same block to the block + * cipher more than once and thus leak information + * (VU#958563). The way we do this is not to take any + * decisions on the basis of anything we've decrypted until + * we've verified it with a MAC. That includes the packet + * length, so we just read data and check the MAC repeatedly, + * and when the MAC passes, see if the length we've got is + * plausible. + */ - /* - * Acquire and decrypt the first block of the packet. This will - * contain the length and padding details. - */ - for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { - while ((*datalen) == 0) - crReturn(st->cipherblk - st->i); - ssh->pktin.data[st->i] = *(*data)++; - (*datalen)--; - } + /* May as well allocate the whole lot now. */ + st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA, + unsigned char); - if (ssh->sccipher) - ssh->sccipher->decrypt(ssh->sc_cipher_ctx, - ssh->pktin.data, st->cipherblk); + /* Read an amount corresponding to the MAC. */ + for (st->i = 0; st->i < st->maclen; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; + } - /* - * Now get the length and padding figures. - */ - st->len = GET_32BIT(ssh->pktin.data); - st->pad = ssh->pktin.data[4]; + st->packetlen = 0; + { + unsigned char seq[4]; + ssh->scmac->start(ssh->sc_mac_ctx); + PUT_32BIT(seq, st->incoming_sequence); + ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4); + } - /* - * _Completely_ silly lengths should be stomped on before they - * do us any more damage. - */ - if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) { - bombout(("Incoming packet was garbled on decryption")); - crStop(0); - } + for (;;) { /* Once around this loop per cipher block. */ + /* Read another cipher-block's worth, and tack it onto the end. */ + for (st->i = 0; st->i < st->cipherblk; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++; + (*datalen)--; + } + /* Decrypt one more block (a little further back in the stream). */ + ssh->sccipher->decrypt(ssh->sc_cipher_ctx, + st->pktin->data + st->packetlen, + st->cipherblk); + /* Feed that block to the MAC. */ + ssh->scmac->bytes(ssh->sc_mac_ctx, + st->pktin->data + st->packetlen, st->cipherblk); + st->packetlen += st->cipherblk; + /* See if that gives us a valid packet. */ + if (ssh->scmac->verresult(ssh->sc_mac_ctx, + st->pktin->data + st->packetlen) && + ((st->len = toint(GET_32BIT(st->pktin->data))) == + st->packetlen-4)) + break; + if (st->packetlen >= OUR_V2_PACKETLIMIT) { + bombout(("No valid incoming packet found")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + } + st->pktin->maxlen = st->packetlen + st->maclen; + st->pktin->data = sresize(st->pktin->data, + st->pktin->maxlen + APIEXTRA, + unsigned char); + } else { + st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char); - /* - * This enables us to deduce the payload length. - */ - st->payload = st->len - st->pad - 1; + /* + * Acquire and decrypt the first block of the packet. This will + * contain the length and padding details. + */ + for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; + } - ssh->pktin.length = st->payload + 5; + if (ssh->sccipher) + ssh->sccipher->decrypt(ssh->sc_cipher_ctx, + st->pktin->data, st->cipherblk); - /* - * So now we can work out the total packet length. - */ - st->packetlen = st->len + 4; - st->maclen = ssh->scmac ? ssh->scmac->len : 0; + /* + * Now get the length figure. + */ + st->len = toint(GET_32BIT(st->pktin->data)); - /* - * Adjust memory allocation if packet is too big. - */ - if (ssh->pktin.maxlen < st->packetlen + st->maclen) { - ssh->pktin.maxlen = st->packetlen + st->maclen; - ssh->pktin.data = sresize(ssh->pktin.data, - ssh->pktin.maxlen + APIEXTRA, + /* + * _Completely_ silly lengths should be stomped on before they + * do us any more damage. + */ + if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT || + (st->len + 4) % st->cipherblk != 0) { + bombout(("Incoming packet was garbled on decryption")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + + /* + * So now we can work out the total packet length. + */ + st->packetlen = st->len + 4; + + /* + * Allocate memory for the rest of the packet. + */ + st->pktin->maxlen = st->packetlen + st->maclen; + st->pktin->data = sresize(st->pktin->data, + st->pktin->maxlen + APIEXTRA, unsigned char); - } - /* - * Read and decrypt the remainder of the packet. - */ - for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; - st->i++) { - while ((*datalen) == 0) - crReturn(st->packetlen + st->maclen - st->i); - ssh->pktin.data[st->i] = *(*data)++; - (*datalen)--; - } - /* Decrypt everything _except_ the MAC. */ - if (ssh->sccipher) - ssh->sccipher->decrypt(ssh->sc_cipher_ctx, - ssh->pktin.data + st->cipherblk, - st->packetlen - st->cipherblk); + /* + * Read and decrypt the remainder of the packet. + */ + for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; + st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; + } + /* Decrypt everything _except_ the MAC. */ + if (ssh->sccipher) + ssh->sccipher->decrypt(ssh->sc_cipher_ctx, + st->pktin->data + st->cipherblk, + st->packetlen - st->cipherblk); + /* + * Check the MAC. + */ + if (ssh->scmac + && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, + st->len + 4, st->incoming_sequence)) { + bombout(("Incorrect MAC received on packet")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + } + /* Get and sanity-check the amount of random padding. */ + st->pad = st->pktin->data[4]; + if (st->pad < 4 || st->len - st->pad < 1) { + bombout(("Invalid padding length on received packet")); + ssh_free_packet(st->pktin); + crStop(NULL); + } /* - * Check the MAC. + * This enables us to deduce the payload length. */ - if (ssh->scmac - && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4, - st->incoming_sequence)) { - bombout(("Incorrect MAC received on packet")); - crStop(0); - } - st->incoming_sequence++; /* whether or not we MACed */ + st->payload = st->len - st->pad - 1; + + st->pktin->length = st->payload + 5; + st->pktin->encrypted_len = st->packetlen; + + st->pktin->sequence = st->incoming_sequence++; /* * Decompress packet payload. @@ -1053,164 +1561,58 @@ static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) int newlen; if (ssh->sccomp && ssh->sccomp->decompress(ssh->sc_comp_ctx, - ssh->pktin.data + 5, ssh->pktin.length - 5, + st->pktin->data + 5, st->pktin->length - 5, &newpayload, &newlen)) { - if (ssh->pktin.maxlen < newlen + 5) { - ssh->pktin.maxlen = newlen + 5; - ssh->pktin.data = sresize(ssh->pktin.data, - ssh->pktin.maxlen + APIEXTRA, + if (st->pktin->maxlen < newlen + 5) { + st->pktin->maxlen = newlen + 5; + st->pktin->data = sresize(st->pktin->data, + st->pktin->maxlen + APIEXTRA, unsigned char); } - ssh->pktin.length = 5 + newlen; - memcpy(ssh->pktin.data + 5, newpayload, newlen); + st->pktin->length = 5 + newlen; + memcpy(st->pktin->data + 5, newpayload, newlen); sfree(newpayload); } } - ssh->pktin.savedpos = 6; - ssh->pktin.type = ssh->pktin.data[5]; + st->pktin->savedpos = 6; + st->pktin->body = st->pktin->data; + st->pktin->type = st->pktin->data[5]; - if (ssh->logctx) - log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type, - ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type), - ssh->pktin.data+6, ssh->pktin.length-6); - - switch (ssh->pktin.type) { - /* - * These packets we must handle instantly. - */ - case SSH2_MSG_DISCONNECT: - { - /* log reason code in disconnect message */ - char *buf; - int nowlen; - int reason = GET_32BIT(ssh->pktin.data + 6); - unsigned msglen = GET_32BIT(ssh->pktin.data + 10); - - if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { - buf = dupprintf("Received disconnect message (%s)", - ssh2_disconnect_reasons[reason]); - } else { - buf = dupprintf("Received disconnect message (unknown" - " type %d)", reason); - } - logevent(buf); - sfree(buf); - buf = dupprintf("Disconnection message text: %n%.*s", - &nowlen, msglen, ssh->pktin.data + 14); - logevent(buf); - bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"", - reason, - (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? - ssh2_disconnect_reasons[reason] : "unknown", - buf+nowlen)); - sfree(buf); - crStop(0); - } - break; - case SSH2_MSG_IGNORE: - goto next_packet; - case SSH2_MSG_DEBUG: - { - /* log the debug message */ - char buf[512]; - /* int display = ssh->pktin.body[6]; */ - int stringlen = GET_32BIT(ssh->pktin.data+7); - int prefix; - strcpy(buf, "Remote debug message: "); - prefix = strlen(buf); - if (stringlen > (int)(sizeof(buf)-prefix-1)) - stringlen = sizeof(buf)-prefix-1; - memcpy(buf + prefix, ssh->pktin.data + 11, stringlen); - buf[prefix + stringlen] = '\0'; - logevent(buf); + /* + * Log incoming packet, possibly omitting sensitive fields. + */ + if (ssh->logctx) { + int nblanks = 0; + struct logblank_t blank; + if (ssh->logomitdata) { + int do_blank = FALSE, blank_prefix = 0; + /* "Session data" packets - omit the data field */ + if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) { + do_blank = TRUE; blank_prefix = 8; + } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { + do_blank = TRUE; blank_prefix = 12; + } + if (do_blank) { + blank.offset = blank_prefix; + blank.len = (st->pktin->length-6) - blank_prefix; + blank.type = PKTLOG_OMIT; + nblanks = 1; + } } - goto next_packet; /* FIXME: print the debug message */ - - /* - * These packets we need do nothing about here. - */ - case SSH2_MSG_UNIMPLEMENTED: - case SSH2_MSG_SERVICE_REQUEST: - case SSH2_MSG_SERVICE_ACCEPT: - case SSH2_MSG_KEXINIT: - case SSH2_MSG_NEWKEYS: - case SSH2_MSG_KEXDH_INIT: - case SSH2_MSG_KEXDH_REPLY: - /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */ - /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */ - case SSH2_MSG_KEX_DH_GEX_INIT: - case SSH2_MSG_KEX_DH_GEX_REPLY: - case SSH2_MSG_USERAUTH_REQUEST: - case SSH2_MSG_USERAUTH_FAILURE: - case SSH2_MSG_USERAUTH_SUCCESS: - case SSH2_MSG_USERAUTH_BANNER: - case SSH2_MSG_USERAUTH_PK_OK: - /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */ - /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */ - case SSH2_MSG_USERAUTH_INFO_RESPONSE: - case SSH2_MSG_GLOBAL_REQUEST: - case SSH2_MSG_REQUEST_SUCCESS: - case SSH2_MSG_REQUEST_FAILURE: - case SSH2_MSG_CHANNEL_OPEN: - case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION: - case SSH2_MSG_CHANNEL_OPEN_FAILURE: - case SSH2_MSG_CHANNEL_WINDOW_ADJUST: - case SSH2_MSG_CHANNEL_DATA: - case SSH2_MSG_CHANNEL_EXTENDED_DATA: - case SSH2_MSG_CHANNEL_EOF: - case SSH2_MSG_CHANNEL_CLOSE: - case SSH2_MSG_CHANNEL_REQUEST: - case SSH2_MSG_CHANNEL_SUCCESS: - case SSH2_MSG_CHANNEL_FAILURE: - break; - - /* - * For anything else we send SSH2_MSG_UNIMPLEMENTED. - */ - default: - ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED); - ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1); - ssh2_pkt_send(ssh); - break; - } - - crFinish(0); -} - -static void ssh1_pktout_size(Ssh ssh, int len) -{ - int pad, biglen; - - len += 5; /* type and CRC */ - pad = 8 - (len % 8); - biglen = len + pad; - - ssh->pktout.length = len - 5; - if (ssh->pktout.maxlen < biglen) { - ssh->pktout.maxlen = biglen; -#ifdef MSCRYPTOAPI - /* Allocate enough buffer space for extra block - * for MS CryptEncrypt() */ - ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12, - unsigned char); -#else - ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4, - unsigned char); -#endif + log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type, + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, + st->pktin->type), + st->pktin->data+6, st->pktin->length-6, + nblanks, &blank, &st->pktin->sequence); } - ssh->pktout.body = ssh->pktout.data + 4 + pad + 1; -} -static void s_wrpkt_start(Ssh ssh, int type, int len) -{ - ssh1_pktout_size(ssh, len); - ssh->pktout.type = type; + crFinish(st->pktin); } -static int s_wrpkt_prepare(Ssh ssh) +static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p) { - int pad, biglen, i; + int pad, biglen, i, pktoffs; unsigned long crc; #ifdef __SC__ /* @@ -1223,155 +1625,156 @@ static int s_wrpkt_prepare(Ssh ssh) #endif int len; - ssh->pktout.body[-1] = ssh->pktout.type; - if (ssh->logctx) - log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type, - ssh1_pkt_type(ssh->pktout.type), - ssh->pktout.body, ssh->pktout.length); + log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12], + ssh1_pkt_type(pkt->data[12]), + pkt->body, pkt->length - (pkt->body - pkt->data), + pkt->nblanks, pkt->blanks, NULL); + sfree(pkt->blanks); pkt->blanks = NULL; + pkt->nblanks = 0; if (ssh->v1_compressing) { unsigned char *compblk; int complen; zlib_compress_block(ssh->cs_comp_ctx, - ssh->pktout.body - 1, ssh->pktout.length + 1, + pkt->data + 12, pkt->length - 12, &compblk, &complen); - ssh1_pktout_size(ssh, complen - 1); - memcpy(ssh->pktout.body - 1, compblk, complen); + ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */ + memcpy(pkt->data + 12, compblk, complen); sfree(compblk); + pkt->length = complen + 12; } - len = ssh->pktout.length + 5; /* type and CRC */ + ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */ + pkt->length += 4; + len = pkt->length - 4 - 8; /* len(type+data+CRC) */ pad = 8 - (len % 8); - biglen = len + pad; + pktoffs = 8 - pad; + biglen = len + pad; /* len(padding+type+data+CRC) */ - for (i = 0; i < pad; i++) - ssh->pktout.data[i + 4] = random_byte(); - crc = crc32_compute(ssh->pktout.data + 4, biglen - 4); - PUT_32BIT(ssh->pktout.data + biglen, crc); - PUT_32BIT(ssh->pktout.data, len); + for (i = pktoffs; i < 4+8; i++) + pkt->data[i] = random_byte(); + crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */ + PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc); + PUT_32BIT(pkt->data + pktoffs, len); if (ssh->cipher) - ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen); + ssh->cipher->encrypt(ssh->v1_cipher_ctx, + pkt->data + pktoffs + 4, biglen); + + if (offset_p) *offset_p = pktoffs; + return biglen + 4; /* len(length+padding+type+data+CRC) */ +} - return biglen + 4; +static int s_write(Ssh ssh, void *data, int len) +{ + if (ssh->logctx) + log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len, + 0, NULL, NULL); + return sk_write(ssh->s, (char *)data, len); } -static void s_wrpkt(Ssh ssh) +static void s_wrpkt(Ssh ssh, struct Packet *pkt) { - int len, backlog; - len = s_wrpkt_prepare(ssh); - backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len); + int len, backlog, offset; + len = s_wrpkt_prepare(ssh, pkt, &offset); + backlog = s_write(ssh, pkt->data + offset, len); if (backlog > SSH_MAX_BACKLOG) ssh_throttle_all(ssh, 1, backlog); + ssh_free_packet(pkt); } -static void s_wrpkt_defer(Ssh ssh) +static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt) { - int len; - len = s_wrpkt_prepare(ssh); + int len, offset; + len = s_wrpkt_prepare(ssh, pkt, &offset); if (ssh->deferred_len + len > ssh->deferred_size) { ssh->deferred_size = ssh->deferred_len + len + 128; ssh->deferred_send_data = sresize(ssh->deferred_send_data, ssh->deferred_size, unsigned char); } - memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len); + memcpy(ssh->deferred_send_data + ssh->deferred_len, + pkt->data + offset, len); ssh->deferred_len += len; + ssh_free_packet(pkt); } /* - * Construct a packet with the specified contents. + * Construct a SSH-1 packet with the specified contents. + * (This all-at-once interface used to be the only one, but now SSH-1 + * packets can also be constructed incrementally.) */ -static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2) +static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap) { - unsigned char *p, *argp, argchar; - unsigned long argint; - int pktlen, argtype, arglen; + int argtype; Bignum bn; + struct Packet *pkt; - pktlen = 0; - while ((argtype = va_arg(ap1, int)) != PKT_END) { + pkt = ssh1_pkt_init(pkttype); + + while ((argtype = va_arg(ap, int)) != PKT_END) { + unsigned char *argp, argchar; + char *sargp; + unsigned long argint; + int arglen; switch (argtype) { + /* Actual fields in the packet */ case PKT_INT: - (void) va_arg(ap1, int); - pktlen += 4; + argint = va_arg(ap, int); + ssh_pkt_adduint32(pkt, argint); break; case PKT_CHAR: - (void) va_arg(ap1, int); - pktlen++; + argchar = (unsigned char) va_arg(ap, int); + ssh_pkt_addbyte(pkt, argchar); break; case PKT_DATA: - (void) va_arg(ap1, unsigned char *); - arglen = va_arg(ap1, int); - pktlen += arglen; + argp = va_arg(ap, unsigned char *); + arglen = va_arg(ap, int); + ssh_pkt_adddata(pkt, argp, arglen); break; case PKT_STR: - argp = va_arg(ap1, unsigned char *); - arglen = strlen((char *)argp); - pktlen += 4 + arglen; + sargp = va_arg(ap, char *); + ssh_pkt_addstring(pkt, sargp); break; case PKT_BIGNUM: - bn = va_arg(ap1, Bignum); - pktlen += ssh1_bignum_length(bn); - break; - default: - assert(0); - } - } - - s_wrpkt_start(ssh, pkttype, pktlen); - p = ssh->pktout.body; - - while ((argtype = va_arg(ap2, int)) != PKT_END) { - switch (argtype) { - case PKT_INT: - argint = va_arg(ap2, int); - PUT_32BIT(p, argint); - p += 4; + bn = va_arg(ap, Bignum); + ssh1_pkt_addmp(pkt, bn); break; - case PKT_CHAR: - argchar = (unsigned char) va_arg(ap2, int); - *p = argchar; - p++; - break; - case PKT_DATA: - argp = va_arg(ap2, unsigned char *); - arglen = va_arg(ap2, int); - memcpy(p, argp, arglen); - p += arglen; + /* Tokens for modifications to packet logging */ + case PKTT_PASSWORD: + dont_log_password(ssh, pkt, PKTLOG_BLANK); break; - case PKT_STR: - argp = va_arg(ap2, unsigned char *); - arglen = strlen((char *)argp); - PUT_32BIT(p, arglen); - memcpy(p + 4, argp, arglen); - p += 4 + arglen; + case PKTT_DATA: + dont_log_data(ssh, pkt, PKTLOG_OMIT); break; - case PKT_BIGNUM: - bn = va_arg(ap2, Bignum); - p += ssh1_write_bignum(p, bn); + case PKTT_OTHER: + end_log_omission(ssh, pkt); break; } } + + return pkt; } static void send_packet(Ssh ssh, int pkttype, ...) { - va_list ap1, ap2; - va_start(ap1, pkttype); - va_start(ap2, pkttype); - construct_packet(ssh, pkttype, ap1, ap2); - s_wrpkt(ssh); + struct Packet *pkt; + va_list ap; + va_start(ap, pkttype); + pkt = construct_packet(ssh, pkttype, ap); + va_end(ap); + s_wrpkt(ssh, pkt); } static void defer_packet(Ssh ssh, int pkttype, ...) { - va_list ap1, ap2; - va_start(ap1, pkttype); - va_start(ap2, pkttype); - construct_packet(ssh, pkttype, ap1, ap2); - s_wrpkt_defer(ssh); + struct Packet *pkt; + va_list ap; + va_start(ap, pkttype); + pkt = construct_packet(ssh, pkttype, ap); + va_end(ap); + s_wrpkt_defer(ssh, pkt); } static int ssh_versioncmp(char *a, char *b) @@ -1396,92 +1799,98 @@ static int ssh_versioncmp(char *a, char *b) /* * Utility routines for putting an SSH-protocol `string' and - * `uint32' into a SHA state. + * `uint32' into a hash state. */ -#include -static void sha_string(SHA_State * s, void *str, int len) +static void hash_string(const struct ssh_hash *h, void *s, void *str, int len) { unsigned char lenblk[4]; PUT_32BIT(lenblk, len); - SHA_Bytes(s, lenblk, 4); - SHA_Bytes(s, str, len); + h->bytes(s, lenblk, 4); + h->bytes(s, str, len); } -static void sha_uint32(SHA_State * s, unsigned i) +static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i) { unsigned char intblk[4]; PUT_32BIT(intblk, i); - SHA_Bytes(s, intblk, 4); + h->bytes(s, intblk, 4); } /* - * SSH2 packet construction functions. + * Packet construction functions. Mostly shared between SSH-1 and SSH-2. */ -static void ssh2_pkt_ensure(Ssh ssh, int length) +static void ssh_pkt_ensure(struct Packet *pkt, int length) { - if (ssh->pktout.maxlen < length) { - ssh->pktout.maxlen = length + 256; - ssh->pktout.data = sresize(ssh->pktout.data, - ssh->pktout.maxlen + APIEXTRA, - unsigned char); - if (!ssh->pktout.data) - fatalbox("Out of memory"); + if (pkt->maxlen < length) { + unsigned char *body = pkt->body; + int offset = body ? body - pkt->data : 0; + pkt->maxlen = length + 256; + pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char); + if (body) pkt->body = pkt->data + offset; } } -static void ssh2_pkt_adddata(Ssh ssh, void *data, int len) -{ - ssh->pktout.length += len; - ssh2_pkt_ensure(ssh, ssh->pktout.length); - memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len); -} -static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte) +static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len) { - ssh2_pkt_adddata(ssh, &byte, 1); + if (pkt->logmode != PKTLOG_EMIT) { + pkt->nblanks++; + pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t); + assert(pkt->body); + pkt->blanks[pkt->nblanks-1].offset = pkt->length - + (pkt->body - pkt->data); + pkt->blanks[pkt->nblanks-1].len = len; + pkt->blanks[pkt->nblanks-1].type = pkt->logmode; + } + pkt->length += len; + ssh_pkt_ensure(pkt, pkt->length); + memcpy(pkt->data + pkt->length - len, data, len); } -static void ssh2_pkt_init(Ssh ssh, int pkt_type) +static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte) { - ssh->pktout.length = 5; - ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type); + ssh_pkt_adddata(pkt, &byte, 1); } -static void ssh2_pkt_addbool(Ssh ssh, unsigned char value) +static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value) { - ssh2_pkt_adddata(ssh, &value, 1); + ssh_pkt_adddata(pkt, &value, 1); } -static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value) +static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value) { unsigned char x[4]; PUT_32BIT(x, value); - ssh2_pkt_adddata(ssh, x, 4); + ssh_pkt_adddata(pkt, x, 4); +} +static void ssh_pkt_addstring_start(struct Packet *pkt) +{ + ssh_pkt_adduint32(pkt, 0); + pkt->savedpos = pkt->length; } -static void ssh2_pkt_addstring_start(Ssh ssh) +static void ssh_pkt_addstring_str(struct Packet *pkt, char *data) { - ssh2_pkt_adduint32(ssh, 0); - ssh->pktout.savedpos = ssh->pktout.length; + ssh_pkt_adddata(pkt, data, strlen(data)); + PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); } -static void ssh2_pkt_addstring_str(Ssh ssh, char *data) +static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len) { - ssh2_pkt_adddata(ssh, data, strlen(data)); - PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4, - ssh->pktout.length - ssh->pktout.savedpos); + ssh_pkt_adddata(pkt, data, len); + PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); } -static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len) +static void ssh_pkt_addstring(struct Packet *pkt, char *data) { - ssh2_pkt_adddata(ssh, data, len); - PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4, - ssh->pktout.length - ssh->pktout.savedpos); + ssh_pkt_addstring_start(pkt); + ssh_pkt_addstring_str(pkt, data); } -static void ssh2_pkt_addstring(Ssh ssh, char *data) +static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b) { - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_str(ssh, data); + int len = ssh1_bignum_length(b); + unsigned char *data = snewn(len, unsigned char); + (void) ssh1_write_bignum(data, b); + ssh_pkt_adddata(pkt, data, len); + sfree(data); } static unsigned char *ssh2_mpint_fmt(Bignum b, int *len) { unsigned char *p; int i, n = (bignum_bitcount(b) + 7) / 8; p = snewn(n + 1, unsigned char); - if (!p) - fatalbox("out of memory"); p[0] = 0; for (i = 1; i <= n; i++) p[i] = bignum_byte(b, n - i); @@ -1492,29 +1901,61 @@ static unsigned char *ssh2_mpint_fmt(Bignum b, int *len) *len = n + 1 - i; return p; } -static void ssh2_pkt_addmp(Ssh ssh, Bignum b) +static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b) { unsigned char *p; int len; p = ssh2_mpint_fmt(b, &len); - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, (char *)p, len); + ssh_pkt_addstring_start(pkt); + ssh_pkt_addstring_data(pkt, (char *)p, len); sfree(p); } +static struct Packet *ssh1_pkt_init(int pkt_type) +{ + struct Packet *pkt = ssh_new_packet(); + pkt->length = 4 + 8; /* space for length + max padding */ + ssh_pkt_addbyte(pkt, pkt_type); + pkt->body = pkt->data + pkt->length; + return pkt; +} + +/* For legacy code (SSH-1 and -2 packet construction used to be separate) */ +#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length) +#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len) +#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte) +#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value) +#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt) +#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data) +#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len) +#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data) + +static struct Packet *ssh2_pkt_init(int pkt_type) +{ + struct Packet *pkt = ssh_new_packet(); + pkt->length = 5; /* space for packet length + padding length */ + pkt->forcepad = 0; + ssh_pkt_addbyte(pkt, (unsigned char) pkt_type); + pkt->body = pkt->data + pkt->length; /* after packet type */ + return pkt; +} + /* - * Construct an SSH2 final-form packet: compress it, encrypt it, + * Construct an SSH-2 final-form packet: compress it, encrypt it, * put the MAC on it. Final packet, ready to be sent, is stored in - * ssh->pktout.data. Total length is returned. + * pkt->data. Total length is returned. */ -static int ssh2_pkt_construct(Ssh ssh) +static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) { int cipherblk, maclen, padding, i; if (ssh->logctx) - log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5], - ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]), - ssh->pktout.data + 6, ssh->pktout.length - 6); + log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5], + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]), + pkt->body, pkt->length - (pkt->body - pkt->data), + pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence); + sfree(pkt->blanks); pkt->blanks = NULL; + pkt->nblanks = 0; /* * Compress packet payload. @@ -1523,11 +1964,11 @@ static int ssh2_pkt_construct(Ssh ssh) unsigned char *newpayload; int newlen; if (ssh->cscomp && - ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5, - ssh->pktout.length - 5, + ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5, + pkt->length - 5, &newpayload, &newlen)) { - ssh->pktout.length = 5; - ssh2_pkt_adddata(ssh, newpayload, newlen); + pkt->length = 5; + ssh2_pkt_adddata(pkt, newpayload, newlen); sfree(newpayload); } } @@ -1535,83 +1976,291 @@ static int ssh2_pkt_construct(Ssh ssh) /* * Add padding. At least four bytes, and must also bring total * length (minus MAC) up to a multiple of the block size. + * If pkt->forcepad is set, make sure the packet is at least that size + * after padding. */ cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */ cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ padding = 4; + if (pkt->length + padding < pkt->forcepad) + padding = pkt->forcepad - pkt->length; padding += - (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk; + (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk; + assert(padding <= 255); maclen = ssh->csmac ? ssh->csmac->len : 0; - ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen); - ssh->pktout.data[4] = padding; + ssh2_pkt_ensure(pkt, pkt->length + padding + maclen); + pkt->data[4] = padding; for (i = 0; i < padding; i++) - ssh->pktout.data[ssh->pktout.length + i] = random_byte(); - PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4); + pkt->data[pkt->length + i] = random_byte(); + PUT_32BIT(pkt->data, pkt->length + padding - 4); if (ssh->csmac) - ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data, - ssh->pktout.length + padding, + ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data, + pkt->length + padding, ssh->v2_outgoing_sequence); ssh->v2_outgoing_sequence++; /* whether or not we MACed */ if (ssh->cscipher) ssh->cscipher->encrypt(ssh->cs_cipher_ctx, - ssh->pktout.data, ssh->pktout.length + padding); + pkt->data, pkt->length + padding); + + pkt->encrypted_len = pkt->length + padding; - /* Ready-to-send packet starts at ssh->pktout.data. We return length. */ - return ssh->pktout.length + padding + maclen; + /* Ready-to-send packet starts at pkt->data. We return length. */ + return pkt->length + padding + maclen; } /* - * Construct and send an SSH2 packet immediately. + * Routines called from the main SSH code to send packets. There + * are quite a few of these, because we have two separate + * mechanisms for delaying the sending of packets: + * + * - In order to send an IGNORE message and a password message in + * a single fixed-length blob, we require the ability to + * concatenate the encrypted forms of those two packets _into_ a + * single blob and then pass it to our transport + * layer in one go. Hence, there's a deferment mechanism which + * works after packet encryption. + * + * - In order to avoid sending any connection-layer messages + * during repeat key exchange, we have to queue up any such + * outgoing messages _before_ they are encrypted (and in + * particular before they're allocated sequence numbers), and + * then send them once we've finished. + * + * I call these mechanisms `defer' and `queue' respectively, so as + * to distinguish them reasonably easily. + * + * The functions send_noqueue() and defer_noqueue() free the packet + * structure they are passed. Every outgoing packet goes through + * precisely one of these functions in its life; packets passed to + * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of + * these or get queued, and then when the queue is later emptied + * the packets are all passed to defer_noqueue(). + * + * When using a CBC-mode cipher, it's necessary to ensure that an + * attacker can't provide data to be encrypted using an IV that they + * know. We ensure this by prefixing each packet that might contain + * user data with an SSH_MSG_IGNORE. This is done using the deferral + * mechanism, so in this case send_noqueue() ends up redirecting to + * defer_noqueue(). If you don't like this inefficiency, don't use + * CBC. + */ + +static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int); +static void ssh_pkt_defersend(Ssh); + +/* + * Send an SSH-2 packet immediately, without queuing or deferring. */ -static void ssh2_pkt_send(Ssh ssh) +static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) { int len; int backlog; - len = ssh2_pkt_construct(ssh); - backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len); + if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) { + /* We need to send two packets, so use the deferral mechanism. */ + ssh2_pkt_defer_noqueue(ssh, pkt, FALSE); + ssh_pkt_defersend(ssh); + return; + } + len = ssh2_pkt_construct(ssh, pkt); + backlog = s_write(ssh, pkt->data, len); if (backlog > SSH_MAX_BACKLOG) ssh_throttle_all(ssh, 1, backlog); + + ssh->outgoing_data_size += pkt->encrypted_len; + if (!ssh->kex_in_progress && + ssh->max_data_size != 0 && + ssh->outgoing_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data sent", -1, NULL); + + ssh_free_packet(pkt); } /* - * Construct an SSH2 packet and add it to a deferred data block. - * Useful for sending multiple packets in a single sk_write() call, - * to prevent a traffic-analysing listener from being able to work - * out the length of any particular packet (such as the password - * packet). - * - * Note that because SSH2 sequence-numbers its packets, this can - * NOT be used as an m4-style `defer' allowing packets to be - * constructed in one order and sent in another. + * Defer an SSH-2 packet. */ -static void ssh2_pkt_defer(Ssh ssh) +static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore) { - int len = ssh2_pkt_construct(ssh); + int len; + if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) && + ssh->deferred_len == 0 && !noignore && + !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { + /* + * Interpose an SSH_MSG_IGNORE to ensure that user data don't + * get encrypted with a known IV. + */ + struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(ipkt); + ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE); + } + len = ssh2_pkt_construct(ssh, pkt); if (ssh->deferred_len + len > ssh->deferred_size) { ssh->deferred_size = ssh->deferred_len + len + 128; ssh->deferred_send_data = sresize(ssh->deferred_send_data, ssh->deferred_size, unsigned char); } - memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len); + memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len); ssh->deferred_len += len; + ssh->deferred_data_size += pkt->encrypted_len; + ssh_free_packet(pkt); +} + +/* + * Queue an SSH-2 packet. + */ +static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt) +{ + assert(ssh->queueing); + + if (ssh->queuelen >= ssh->queuesize) { + ssh->queuesize = ssh->queuelen + 32; + ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *); + } + + ssh->queue[ssh->queuelen++] = pkt; +} + +/* + * Either queue or send a packet, depending on whether queueing is + * set. + */ +static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt) +{ + if (ssh->queueing) + ssh2_pkt_queue(ssh, pkt); + else + ssh2_pkt_send_noqueue(ssh, pkt); +} + +/* + * Either queue or defer a packet, depending on whether queueing is + * set. + */ +static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt) +{ + if (ssh->queueing) + ssh2_pkt_queue(ssh, pkt); + else + ssh2_pkt_defer_noqueue(ssh, pkt, FALSE); } /* * Send the whole deferred data block constructed by - * ssh2_pkt_defer() or SSH1's defer_packet(). + * ssh2_pkt_defer() or SSH-1's defer_packet(). + * + * The expected use of the defer mechanism is that you call + * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If + * not currently queueing, this simply sets up deferred_send_data + * and then sends it. If we _are_ currently queueing, the calls to + * ssh2_pkt_defer() put the deferred packets on to the queue + * instead, and therefore ssh_pkt_defersend() has no deferred data + * to send. Hence, there's no need to make it conditional on + * ssh->queueing. */ static void ssh_pkt_defersend(Ssh ssh) { int backlog; - backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data, - ssh->deferred_len); + backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len); ssh->deferred_len = ssh->deferred_size = 0; sfree(ssh->deferred_send_data); ssh->deferred_send_data = NULL; if (backlog > SSH_MAX_BACKLOG) ssh_throttle_all(ssh, 1, backlog); + + ssh->outgoing_data_size += ssh->deferred_data_size; + if (!ssh->kex_in_progress && + ssh->max_data_size != 0 && + ssh->outgoing_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data sent", -1, NULL); + ssh->deferred_data_size = 0; +} + +/* + * Send a packet whose length needs to be disguised (typically + * passwords or keyboard-interactive responses). + */ +static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt, + int padsize) +{ +#if 0 + if (0) { + /* + * The simplest way to do this is to adjust the + * variable-length padding field in the outgoing packet. + * + * Currently compiled out, because some Cisco SSH servers + * don't like excessively padded packets (bah, why's it + * always Cisco?) + */ + pkt->forcepad = padsize; + ssh2_pkt_send(ssh, pkt); + } else +#endif + { + /* + * If we can't do that, however, an alternative approach is + * to use the pkt_defer mechanism to bundle the packet + * tightly together with an SSH_MSG_IGNORE such that their + * combined length is a constant. So first we construct the + * final form of this packet and defer its sending. + */ + ssh2_pkt_defer(ssh, pkt); + + /* + * Now construct an SSH_MSG_IGNORE which includes a string + * that's an exact multiple of the cipher block size. (If + * the cipher is NULL so that the block size is + * unavailable, we don't do this trick at all, because we + * gain nothing by it.) + */ + if (ssh->cscipher && + !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { + int stringlen, i; + + stringlen = (256 - ssh->deferred_len); + stringlen += ssh->cscipher->blksize - 1; + stringlen -= (stringlen % ssh->cscipher->blksize); + if (ssh->cscomp) { + /* + * Temporarily disable actual compression, so we + * can guarantee to get this string exactly the + * length we want it. The compression-disabling + * routine should return an integer indicating how + * many bytes we should adjust our string length + * by. + */ + stringlen -= + ssh->cscomp->disable_compression(ssh->cs_comp_ctx); + } + pkt = ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(pkt); + for (i = 0; i < stringlen; i++) { + char c = (char) random_byte(); + ssh2_pkt_addstring_data(pkt, &c, 1); + } + ssh2_pkt_defer(ssh, pkt); + } + ssh_pkt_defersend(ssh); + } +} + +/* + * Send all queued SSH-2 packets. We send them by means of + * ssh2_pkt_defer_noqueue(), in case they included a pair of + * packets that needed to be lumped together. + */ +static void ssh2_pkt_queuesend(Ssh ssh) +{ + int i; + + assert(!ssh->queueing); + + for (i = 0; i < ssh->queuelen; i++) + ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE); + ssh->queuelen = 0; + + ssh_pkt_defersend(ssh); } #if 0 @@ -1628,78 +2277,115 @@ void bndebug(char *string, Bignum b) } #endif -static void sha_mpint(SHA_State * s, Bignum b) +static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b) { unsigned char *p; int len; p = ssh2_mpint_fmt(b, &len); - sha_string(s, p, len); + hash_string(h, s, p, len); sfree(p); } /* - * SSH2 packet decode functions. + * Packet decode functions for both SSH-1 and SSH-2. */ -static unsigned long ssh2_pkt_getuint32(Ssh ssh) +static unsigned long ssh_pkt_getuint32(struct Packet *pkt) { unsigned long value; - if (ssh->pktin.length - ssh->pktin.savedpos < 4) + if (pkt->length - pkt->savedpos < 4) return 0; /* arrgh, no way to decline (FIXME?) */ - value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos); - ssh->pktin.savedpos += 4; + value = GET_32BIT(pkt->body + pkt->savedpos); + pkt->savedpos += 4; return value; } -static int ssh2_pkt_getbool(Ssh ssh) +static int ssh2_pkt_getbool(struct Packet *pkt) { unsigned long value; - if (ssh->pktin.length - ssh->pktin.savedpos < 1) + if (pkt->length - pkt->savedpos < 1) return 0; /* arrgh, no way to decline (FIXME?) */ - value = ssh->pktin.data[ssh->pktin.savedpos] != 0; - ssh->pktin.savedpos++; + value = pkt->body[pkt->savedpos] != 0; + pkt->savedpos++; return value; } -static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length) +static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length) { int len; *p = NULL; *length = 0; - if (ssh->pktin.length - ssh->pktin.savedpos < 4) + if (pkt->length - pkt->savedpos < 4) return; - len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos); + len = toint(GET_32BIT(pkt->body + pkt->savedpos)); if (len < 0) return; *length = len; - ssh->pktin.savedpos += 4; - if (ssh->pktin.length - ssh->pktin.savedpos < *length) + pkt->savedpos += 4; + if (pkt->length - pkt->savedpos < *length) return; - *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos); - ssh->pktin.savedpos += *length; + *p = (char *)(pkt->body + pkt->savedpos); + pkt->savedpos += *length; +} +static void *ssh_pkt_getdata(struct Packet *pkt, int length) +{ + if (pkt->length - pkt->savedpos < length) + return NULL; + pkt->savedpos += length; + return pkt->body + (pkt->savedpos - length); +} +static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key, + unsigned char **keystr) +{ + int j; + + j = makekey(pkt->body + pkt->savedpos, + pkt->length - pkt->savedpos, + key, keystr, 0); + + if (j < 0) + return FALSE; + + pkt->savedpos += j; + assert(pkt->savedpos < pkt->length); + + return TRUE; +} +static Bignum ssh1_pkt_getmp(struct Packet *pkt) +{ + int j; + Bignum b; + + j = ssh1_read_bignum(pkt->body + pkt->savedpos, + pkt->length - pkt->savedpos, &b); + + if (j < 0) + return NULL; + + pkt->savedpos += j; + return b; } -static Bignum ssh2_pkt_getmp(Ssh ssh) +static Bignum ssh2_pkt_getmp(struct Packet *pkt) { char *p; int length; Bignum b; - ssh2_pkt_getstring(ssh, &p, &length); + ssh_pkt_getstring(pkt, &p, &length); if (!p) return NULL; - if (p[0] & 0x80) { - bombout(("internal error: Can't handle negative mpints")); + if (p[0] & 0x80) return NULL; - } b = bignum_from_bytes((unsigned char *)p, length); return b; } /* - * Helper function to add an SSH2 signature blob to a packet. + * Helper function to add an SSH-2 signature blob to a packet. * Expects to be shown the public key blob as well as the signature * blob. Normally works just like ssh2_pkt_addstring, but will * fiddle with the signature packet if necessary for * BUG_SSH2_RSA_PADDING. */ -static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len, +static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt, + void *pkblob_v, int pkblob_len, void *sigblob_v, int sigblob_len) { unsigned char *pkblob = (unsigned char *)pkblob_v; @@ -1712,7 +2398,7 @@ static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len, * See if this is in fact an ssh-rsa signature and a buggy * server; otherwise we can just do this the easy way. */ - if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && + if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 && (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) { int pos, len, siglen; @@ -1721,8 +2407,15 @@ static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len, */ pos = 4+7; /* skip over "ssh-rsa" */ - pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */ - len = GET_32BIT(pkblob+pos); /* find length of modulus */ + len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */ + if (len < 0 || len > pkblob_len - pos - 4) + goto give_up; + pos += 4 + len; /* skip over exponent */ + if (pkblob_len - pos < 4) + goto give_up; + len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */ + if (len < 0 || len > pkblob_len - pos - 4) + goto give_up; pos += 4; /* find modulus itself */ while (len > 0 && pkblob[pos] == 0) len--, pos++; @@ -1732,33 +2425,40 @@ static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len, * Now find the signature integer. */ pos = 4+7; /* skip over "ssh-rsa" */ - siglen = GET_32BIT(sigblob+pos); + if (sigblob_len < pos+4) + goto give_up; + siglen = toint(GET_32BIT(sigblob+pos)); + if (siglen != sigblob_len - pos - 4) + goto give_up; /* debug(("signature length is %d\n", siglen)); */ if (len != siglen) { unsigned char newlen[4]; - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos); + ssh2_pkt_addstring_start(pkt); + ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos); /* dmemdump(sigblob, pos); */ pos += 4; /* point to start of actual sig */ PUT_32BIT(newlen, len); - ssh2_pkt_addstring_data(ssh, (char *)newlen, 4); + ssh2_pkt_addstring_data(pkt, (char *)newlen, 4); /* dmemdump(newlen, 4); */ newlen[0] = 0; while (len-- > siglen) { - ssh2_pkt_addstring_data(ssh, (char *)newlen, 1); + ssh2_pkt_addstring_data(pkt, (char *)newlen, 1); /* dmemdump(newlen, 1); */ } - ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen); + ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen); /* dmemdump(sigblob+pos, siglen); */ return; } - /* Otherwise fall through and do it the easy way. */ + /* Otherwise fall through and do it the easy way. We also come + * here as a fallback if we discover above that the key blob + * is misformatted in some way. */ + give_up:; } - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len); + ssh2_pkt_addstring_start(pkt); + ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len); } /* @@ -1776,23 +2476,30 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) ssh->remote_bugs = 0; - if (ssh->cfg.sshbug_ignore1 == FORCE_ON || - (ssh->cfg.sshbug_ignore1 == AUTO && + /* + * General notes on server version strings: + * - Not all servers reporting "Cisco-1.25" have all the bugs listed + * here -- in particular, we've heard of one that's perfectly happy + * with SSH1_MSG_IGNOREs -- but this string never seems to change, + * so we can't distinguish them. + */ + if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO && (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") || - !strcmp(imp, "OSU_1.4alpha3")))) { + !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) { /* * These versions don't support SSH1_MSG_IGNORE, so we have * to use a different defence against password length * sniffing. */ ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; - logevent("We believe remote version has SSH1 ignore bug"); + logevent("We believe remote version has SSH-1 ignore bug"); } - if (ssh->cfg.sshbug_plainpw1 == FORCE_ON || - (ssh->cfg.sshbug_plainpw1 == AUTO && + if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO && (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) { /* * These versions need a plain password sent; they can't @@ -1800,11 +2507,11 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * the password. */ ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; - logevent("We believe remote version needs a plain SSH1 password"); + logevent("We believe remote version needs a plain SSH-1 password"); } - if (ssh->cfg.sshbug_rsa1 == FORCE_ON || - (ssh->cfg.sshbug_rsa1 == AUTO && + if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO && (!strcmp(imp, "Cisco-1.25")))) { /* * These versions apparently have no clue whatever about @@ -1812,11 +2519,11 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * an AUTH_RSA message. */ ssh->remote_bugs |= BUG_CHOKES_ON_RSA; - logevent("We believe remote version can't handle RSA authentication"); + logevent("We believe remote version can't handle SSH-1 RSA authentication"); } - if (ssh->cfg.sshbug_hmac2 == FORCE_ON || - (ssh->cfg.sshbug_hmac2 == AUTO && + if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO && !wc_match("* VShell", imp) && (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) || wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) || @@ -1825,11 +2532,11 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * These versions have the HMAC bug. */ ssh->remote_bugs |= BUG_SSH2_HMAC; - logevent("We believe remote version has SSH2 HMAC bug"); + logevent("We believe remote version has SSH-2 HMAC bug"); } - if (ssh->cfg.sshbug_derivekey2 == FORCE_ON || - (ssh->cfg.sshbug_derivekey2 == AUTO && + if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO && !wc_match("* VShell", imp) && (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) { /* @@ -1838,43 +2545,145 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * generate the keys). */ ssh->remote_bugs |= BUG_SSH2_DERIVEKEY; - logevent("We believe remote version has SSH2 key-derivation bug"); + logevent("We believe remote version has SSH-2 key-derivation bug"); } - if (ssh->cfg.sshbug_rsapad2 == FORCE_ON || - (ssh->cfg.sshbug_rsapad2 == AUTO && + if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO && (wc_match("OpenSSH_2.[5-9]*", imp) || wc_match("OpenSSH_3.[0-2]*", imp)))) { /* - * These versions have the SSH2 RSA padding bug. + * These versions have the SSH-2 RSA padding bug. */ ssh->remote_bugs |= BUG_SSH2_RSA_PADDING; - logevent("We believe remote version has SSH2 RSA padding bug"); + logevent("We believe remote version has SSH-2 RSA padding bug"); } - if (ssh->cfg.sshbug_pksessid2 == FORCE_ON || - (ssh->cfg.sshbug_pksessid2 == AUTO && + if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO && wc_match("OpenSSH_2.[0-2]*", imp))) { /* - * These versions have the SSH2 session-ID bug in + * These versions have the SSH-2 session-ID bug in * public-key authentication. */ ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID; - logevent("We believe remote version has SSH2 public-key-session-ID bug"); + logevent("We believe remote version has SSH-2 public-key-session-ID bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO && + (wc_match("DigiSSH_2.0", imp) || + wc_match("OpenSSH_2.[0-4]*", imp) || + wc_match("OpenSSH_2.5.[0-3]*", imp) || + wc_match("Sun_SSH_1.0", imp) || + wc_match("Sun_SSH_1.0.1", imp) || + /* All versions <= 1.2.6 (they changed their format in 1.2.7) */ + wc_match("WeOnlyDo-*", imp)))) { + /* + * These versions have the SSH-2 rekey bug. + */ + ssh->remote_bugs |= BUG_SSH2_REKEY; + logevent("We believe remote version has SSH-2 rekey bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO && + (wc_match("1.36_sshlib GlobalSCAPE", imp) || + wc_match("1.36 sshlib: GlobalScape", imp)))) { + /* + * This version ignores our makpkt and needs to be throttled. + */ + ssh->remote_bugs |= BUG_SSH2_MAXPKT; + logevent("We believe remote version ignores SSH-2 maximum packet size"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) { + /* + * Servers that don't support SSH2_MSG_IGNORE. Currently, + * none detected automatically. + */ + ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE; + logevent("We believe remote version has SSH-2 ignore bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) { + /* + * Servers that don't support our winadj request for one + * reason or another. Currently, none detected automatically. + */ + ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ; + logevent("We believe remote version has winadj bug"); + } +} + +/* + * The `software version' part of an SSH version string is required + * to contain no spaces or minus signs. + */ +static void ssh_fix_verstring(char *str) +{ + /* Eat "SSH--". */ + assert(*str == 'S'); str++; + assert(*str == 'S'); str++; + assert(*str == 'H'); str++; + assert(*str == '-'); str++; + while (*str && *str != '-') str++; + assert(*str == '-'); str++; + + /* Convert minus signs and spaces in the remaining string into + * underscores. */ + while (*str) { + if (*str == '-' || *str == ' ') + *str = '_'; + str++; + } +} + +/* + * Send an appropriate SSH version string. + */ +static void ssh_send_verstring(Ssh ssh, char *svers) +{ + char *verstring; + + if (ssh->version == 2) { + /* + * Construct a v2 version string. + */ + verstring = dupprintf("SSH-2.0-%s\015\012", sshver); + } else { + /* + * Construct a v1 version string. + */ + verstring = dupprintf("SSH-%s-%s\012", + (ssh_versioncmp(svers, "1.5") <= 0 ? + svers : "1.5"), + sshver); } - if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) { + ssh_fix_verstring(verstring); + + if (ssh->version == 2) { + size_t len; /* - * User specified the SSH2 DH GEX bug. + * Record our version string. */ - ssh->remote_bugs |= BUG_SSH2_DH_GEX; - logevent("We believe remote version has SSH2 DH group exchange bug"); + len = strcspn(verstring, "\015\012"); + ssh->v_c = snewn(len + 1, char); + memcpy(ssh->v_c, verstring, len); + ssh->v_c[len] = 0; } + + logeventf(ssh, "We claim version: %.*s", + strcspn(verstring, "\015\012"), verstring); + s_write(ssh, verstring, strlen(verstring)); + sfree(verstring); } static int do_ssh_init(Ssh ssh, unsigned char c) { struct do_ssh_init_state { + int crLine; int vslen; char version[10]; char *vstring; @@ -1883,26 +2692,23 @@ static int do_ssh_init(Ssh ssh, unsigned char c) int proto1, proto2; }; crState(do_ssh_init_state); + + crBeginState; - crBegin(ssh->do_ssh_init_crstate); - - /* Search for the string "SSH-" in the input. */ - s->i = 0; - while (1) { - static const int transS[] = { 1, 2, 2, 1 }; - static const int transH[] = { 0, 0, 3, 0 }; - static const int transminus[] = { 0, 0, 0, -1 }; - if (c == 'S') - s->i = transS[s->i]; - else if (c == 'H') - s->i = transH[s->i]; - else if (c == '-') - s->i = transminus[s->i]; - else - s->i = 0; - if (s->i < 0) - break; - crReturn(1); /* get another character */ + /* Search for a line beginning with the string "SSH-" in the input. */ + for (;;) { + if (c != 'S') goto no; + crReturn(1); + if (c != 'S') goto no; + crReturn(1); + if (c != 'H') goto no; + crReturn(1); + if (c != '-') goto no; + break; + no: + while (c != '\012') + crReturn(1); + crReturn(1); } s->vstrsize = 16; @@ -1931,14 +2737,8 @@ static int do_ssh_init(Ssh ssh, unsigned char c) ssh->rdpkt2_state.incoming_sequence = 0; s->vstring[s->vslen] = 0; - s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */ - { - char *vlog; - vlog = snewn(20 + s->vslen, char); - sprintf(vlog, "Server version: %s", s->vstring); - logevent(vlog); - sfree(vlog); - } + s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */ + logeventf(ssh, "Server version: %s", s->vstring); ssh_detect_bugs(ssh, s->vstring); /* @@ -1950,63 +2750,115 @@ static int do_ssh_init(Ssh ssh, unsigned char c) /* Anything greater or equal to "1.99" means protocol 2 is supported. */ s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0; - if (ssh->cfg.sshprot == 0 && !s->proto1) { + if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) { bombout(("SSH protocol version 1 required by user but not provided by server")); crStop(0); } - if (ssh->cfg.sshprot == 3 && !s->proto2) { + if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) { bombout(("SSH protocol version 2 required by user but not provided by server")); crStop(0); } - if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) { + if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1)) + ssh->version = 2; + else + ssh->version = 1; + + logeventf(ssh, "Using SSH protocol version %d", ssh->version); + + /* Send the version string, if we haven't already */ + if (conf_get_int(ssh->conf, CONF_sshprot) != 3) + ssh_send_verstring(ssh, s->version); + + if (ssh->version == 2) { + size_t len; /* - * Use v2 protocol. + * Record their version string. */ - char verstring[80], vlog[100]; - sprintf(verstring, "SSH-2.0-%s", sshver); - SHA_Init(&ssh->exhashbase); + len = strcspn(s->vstring, "\015\012"); + ssh->v_s = snewn(len + 1, char); + memcpy(ssh->v_s, s->vstring, len); + ssh->v_s[len] = 0; + /* - * Hash our version string and their version string. + * Initialise SSH-2 protocol. */ - sha_string(&ssh->exhashbase, verstring, strlen(verstring)); - sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n")); - sprintf(vlog, "We claim version: %s", verstring); - logevent(vlog); - strcat(verstring, "\012"); - logevent("Using SSH protocol version 2"); - sk_write(ssh->s, verstring, strlen(verstring)); ssh->protocol = ssh2_protocol; - ssh->version = 2; + ssh2_protocol_setup(ssh); ssh->s_rdpkt = ssh2_rdpkt; } else { /* - * Use v1 protocol. + * Initialise SSH-1 protocol. */ - char verstring[80], vlog[100]; - sprintf(verstring, "SSH-%s-%s", - (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"), - sshver); - sprintf(vlog, "We claim version: %s", verstring); - logevent(vlog); - strcat(verstring, "\012"); - - logevent("Using SSH protocol version 1"); - sk_write(ssh->s, verstring, strlen(verstring)); ssh->protocol = ssh1_protocol; - ssh->version = 1; + ssh1_protocol_setup(ssh); ssh->s_rdpkt = ssh1_rdpkt; } + if (ssh->version == 2) + do_ssh2_transport(ssh, NULL, -1, NULL); + update_specials_menu(ssh->frontend); ssh->state = SSH_STATE_BEFORE_SIZE; + ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh); sfree(s->vstring); crFinish(0); } +static void ssh_process_incoming_data(Ssh ssh, + unsigned char **data, int *datalen) +{ + struct Packet *pktin; + + pktin = ssh->s_rdpkt(ssh, data, datalen); + if (pktin) { + ssh->protocol(ssh, NULL, 0, pktin); + ssh_free_packet(pktin); + } +} + +static void ssh_queue_incoming_data(Ssh ssh, + unsigned char **data, int *datalen) +{ + bufchain_add(&ssh->queued_incoming_data, *data, *datalen); + *data += *datalen; + *datalen = 0; +} + +static void ssh_process_queued_incoming_data(Ssh ssh) +{ + void *vdata; + unsigned char *data; + int len, origlen; + + while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) { + bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len); + data = vdata; + origlen = len; + + while (!ssh->frozen && len > 0) + ssh_process_incoming_data(ssh, &data, &len); + + if (origlen > len) + bufchain_consume(&ssh->queued_incoming_data, origlen - len); + } +} + +static void ssh_set_frozen(Ssh ssh, int frozen) +{ + if (ssh->s) + sk_set_frozen(ssh->s, frozen); + ssh->frozen = frozen; +} + static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) { + /* Log raw data, if we're in that mode. */ + if (ssh->logctx) + log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen, + 0, NULL, NULL); + crBegin(ssh->ssh_gotdata_crstate); /* @@ -2032,69 +2884,130 @@ static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) * everything to s_rdpkt, and then pass the resulting packets * to the proper protocol handler. */ - if (datalen == 0) - crReturnV; + while (1) { - while (datalen > 0) { - if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) { - if (ssh->state == SSH_STATE_CLOSED) { - return; - } - ssh->protocol(ssh, NULL, 0, 1); - if (ssh->state == SSH_STATE_CLOSED) { - return; - } + while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) { + if (ssh->frozen) { + ssh_queue_incoming_data(ssh, &data, &datalen); + /* This uses up all data and cannot cause anything interesting + * to happen; indeed, for anything to happen at all, we must + * return, so break out. */ + break; + } else if (bufchain_size(&ssh->queued_incoming_data) > 0) { + /* This uses up some or all data, and may freeze the + * session. */ + ssh_process_queued_incoming_data(ssh); + } else { + /* This uses up some or all data, and may freeze the + * session. */ + ssh_process_incoming_data(ssh, &data, &datalen); } + /* FIXME this is probably EBW. */ + if (ssh->state == SSH_STATE_CLOSED) + return; } + /* We're out of data. Go and get some more. */ crReturnV; } crFinishV; } -static void ssh_do_close(Ssh ssh) +static int ssh_do_close(Ssh ssh, int notify_exit) { - int i; + int ret = 0; struct ssh_channel *c; ssh->state = SSH_STATE_CLOSED; + expire_timer_context(ssh); if (ssh->s) { sk_close(ssh->s); ssh->s = NULL; + if (notify_exit) + notify_remote_exit(ssh->frontend); + else + ret = 1; } /* - * Now we must shut down any port and X forwardings going + * Now we must shut down any port- and X-forwarded channels going * through this connection. */ if (ssh->channels) { - for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { + while (NULL != (c = index234(ssh->channels, 0))) { switch (c->type) { case CHAN_X11: x11_close(c->u.x11.s); break; case CHAN_SOCKDATA: + case CHAN_SOCKDATA_DORMANT: pfd_close(c->u.pfd.s); break; } - del234(ssh->channels, c); + del234(ssh->channels, c); /* moving next one to index 0 */ if (ssh->version == 2) bufchain_clear(&c->v.v2.outbuffer); sfree(c); } } + /* + * Go through port-forwardings, and close any associated + * listening sockets. + */ + if (ssh->portfwds) { + struct ssh_portfwd *pf; + while (NULL != (pf = index234(ssh->portfwds, 0))) { + /* Dispose of any listening socket. */ + if (pf->local) + pfd_terminate(pf->local); + del234(ssh->portfwds, pf); /* moving next one to index 0 */ + free_portfwd(pf); + } + freetree234(ssh->portfwds); + ssh->portfwds = NULL; + } + + return ret; } -static int ssh_closing(Plug plug, const char *error_msg, int error_code, +static void ssh_log(Plug plug, int type, SockAddr addr, int port, + const char *error_msg, int error_code) +{ + Ssh ssh = (Ssh) plug; + char addrbuf[256], *msg; + + sk_getaddr(addr, addrbuf, lenof(addrbuf)); + + if (type == 0) + msg = dupprintf("Connecting to %s port %d", addrbuf, port); + else + msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg); + + logevent(msg); + sfree(msg); +} + +static int ssh_closing(Plug plug, const char *error_msg, int error_code, int calling_back) { Ssh ssh = (Ssh) plug; - ssh_do_close(ssh); - if (error_msg) { - /* A socket error has occurred. */ + int need_notify = ssh_do_close(ssh, FALSE); + + if (!error_msg) { + if (!ssh->close_expected) + error_msg = "Server unexpectedly closed network connection"; + else + error_msg = "Server closed network connection"; + } + + if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0) + ssh->exitcode = 0; + + if (need_notify) + notify_remote_exit(ssh->frontend); + + if (error_msg) logevent(error_msg); + if (!ssh->close_expected || !ssh->clean_exit) connection_fatal(ssh->frontend, "%s", error_msg); - } else { - /* Otherwise, the remote side closed the connection normally. */ - } return 0; } @@ -2103,7 +3016,7 @@ static int ssh_receive(Plug plug, int urgent, char *data, int len) Ssh ssh = (Ssh) plug; ssh_gotdata(ssh, (unsigned char *)data, len); if (ssh->state == SSH_STATE_CLOSED) { - ssh_do_close(ssh); + ssh_do_close(ssh, TRUE); return 0; } return 1; @@ -2127,9 +3040,10 @@ static void ssh_sent(Plug plug, int bufsize) * freed by the caller. */ static const char *connect_to_host(Ssh ssh, char *host, int port, - char **realhost, int nodelay) + char **realhost, int nodelay, int keepalive) { static const struct plug_function_table fn_table = { + ssh_log, ssh_closing, ssh_receive, ssh_sent, @@ -2138,57 +3052,96 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, SockAddr addr; const char *err; + char *loghost; + int addressfamily, sshprot; + + loghost = conf_get_str(ssh->conf, CONF_loghost); + if (*loghost) { + char *colon; - ssh->savedhost = snewn(1 + strlen(host), char); - if (!ssh->savedhost) - fatalbox("Out of memory"); - strcpy(ssh->savedhost, host); + ssh->savedhost = dupstr(loghost); + ssh->savedport = 22; /* default ssh port */ - if (port < 0) - port = 22; /* default ssh port */ - ssh->savedport = port; + /* + * A colon suffix on savedhost also lets us affect + * savedport. + * + * (FIXME: do something about IPv6 address literals here.) + */ + colon = strrchr(ssh->savedhost, ':'); + if (colon) { + *colon++ = '\0'; + if (*colon) + ssh->savedport = atoi(colon); + } + } else { + ssh->savedhost = dupstr(host); + if (port < 0) + port = 22; /* default ssh port */ + ssh->savedport = port; + } /* * Try to find host. */ - logeventf(ssh, "Looking up host \"%s\"", host); - addr = name_lookup(host, port, realhost, &ssh->cfg); + addressfamily = conf_get_int(ssh->conf, CONF_addressfamily); + logeventf(ssh, "Looking up host \"%s\"%s", host, + (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" : + (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : ""))); + addr = name_lookup(host, port, realhost, ssh->conf, addressfamily); if ((err = sk_addr_error(addr)) != NULL) { sk_addr_free(addr); return err; } + ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */ /* * Open socket. */ - { - char addrbuf[100]; - sk_getaddr(addr, addrbuf, 100); - logeventf(ssh, "Connecting to %s port %d", addrbuf, port); - } ssh->fn = &fn_table; ssh->s = new_connection(addr, *realhost, port, - 0, 1, nodelay, (Plug) ssh, &ssh->cfg); + 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf); if ((err = sk_socket_error(ssh->s)) != NULL) { ssh->s = NULL; + notify_remote_exit(ssh->frontend); return err; } + /* + * If the SSH version number's fixed, set it now, and if it's SSH-2, + * send the version string too. + */ + sshprot = conf_get_int(ssh->conf, CONF_sshprot); + if (sshprot == 0) + ssh->version = 1; + if (sshprot == 3) { + ssh->version = 2; + ssh_send_verstring(ssh, NULL); + } + + /* + * loghost, if configured, overrides realhost. + */ + if (*loghost) { + sfree(*realhost); + *realhost = dupstr(loghost); + } + return NULL; } /* * Throttle or unthrottle the SSH connection. */ -static void ssh1_throttle(Ssh ssh, int adjust) +static void ssh_throttle_conn(Ssh ssh, int adjust) { - int old_count = ssh->v1_throttle_count; - ssh->v1_throttle_count += adjust; - assert(ssh->v1_throttle_count >= 0); - if (ssh->v1_throttle_count && !old_count) { - sk_set_frozen(ssh->s, 1); - } else if (!ssh->v1_throttle_count && old_count) { - sk_set_frozen(ssh->s, 0); + int old_count = ssh->conn_throttle_count; + ssh->conn_throttle_count += adjust; + assert(ssh->conn_throttle_count >= 0); + if (ssh->conn_throttle_count && !old_count) { + ssh_set_frozen(ssh, 1); + } else if (!ssh->conn_throttle_count && old_count) { + ssh_set_frozen(ssh, 0); } } @@ -2227,89 +3180,35 @@ static void ssh_throttle_all(Ssh ssh, int enable, int bufsize) } } -/* - * Username and password input, abstracted off into routines - * reusable in several places - even between SSH1 and SSH2. - */ - -/* Set up a username or password input loop on a given buffer. */ -static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo) +static void ssh_agent_callback(void *sshv, void *reply, int replylen) { - ssh->userpass_input_buffer = buffer; - ssh->userpass_input_buflen = buflen; - ssh->userpass_input_bufpos = 0; - ssh->userpass_input_echo = echo; -} + Ssh ssh = (Ssh) sshv; -/* - * Process some terminal data in the course of username/password - * input. Returns >0 for success (line of input returned in - * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0 - * for inconclusive (keep waiting for more input please). - */ -static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen) -{ - char c; + ssh->agent_response = reply; + ssh->agent_response_len = replylen; - while (inlen--) { - switch (c = *in++) { - case 10: - case 13: - ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0; - ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0; - return +1; - break; - case 8: - case 127: - if (ssh->userpass_input_bufpos > 0) { - if (ssh->userpass_input_echo) - c_write_str(ssh, "\b \b"); - ssh->userpass_input_bufpos--; - } - break; - case 21: - case 27: - while (ssh->userpass_input_bufpos > 0) { - if (ssh->userpass_input_echo) - c_write_str(ssh, "\b \b"); - ssh->userpass_input_bufpos--; - } - break; - case 3: - case 4: - return -1; - break; - default: - /* - * This simplistic check for printability is disabled - * when we're doing password input, because some people - * have control characters in their passwords.o - */ - if ((!ssh->userpass_input_echo || - (c >= ' ' && c <= '~') || - ((unsigned char) c >= 160)) - && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) { - ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c; - if (ssh->userpass_input_echo) - c_write(ssh, &c, 1); - } - break; - } - } - return 0; + if (ssh->version == 1) + do_ssh1_login(ssh, NULL, -1, NULL); + else + do_ssh2_authconn(ssh, NULL, -1, NULL); } -static void ssh_agent_callback(void *sshv, void *reply, int replylen) +static void ssh_dialog_callback(void *sshv, int ret) { Ssh ssh = (Ssh) sshv; - ssh->agent_response = reply; - ssh->agent_response_len = replylen; + ssh->user_response = ret; if (ssh->version == 1) - do_ssh1_login(ssh, NULL, -1, 0); + do_ssh1_login(ssh, NULL, -1, NULL); else - do_ssh2_authconn(ssh, NULL, -1, 0); + do_ssh2_transport(ssh, NULL, -1, NULL); + + /* + * This may have unfrozen the SSH connection, so do a + * queued-data run. + */ + ssh_process_queued_incoming_data(ssh); } static void ssh_agentf_callback(void *cv, void *reply, int replylen) @@ -2318,6 +3217,7 @@ static void ssh_agentf_callback(void *cv, void *reply, int replylen) Ssh ssh = c->ssh; void *sentreply = reply; + c->u.a.outstanding_requests--; if (!sentreply) { /* Fake SSH_AGENT_FAILURE. */ sentreply = "\0\0\0\1\5"; @@ -2330,23 +3230,65 @@ static void ssh_agentf_callback(void *cv, void *reply, int replylen) send_packet(ssh, SSH1_MSG_CHANNEL_DATA, PKT_INT, c->remoteid, PKT_INT, replylen, + PKTT_DATA, PKT_DATA, sentreply, replylen, + PKTT_OTHER, PKT_END); } if (reply) sfree(reply); + /* + * If we've already seen an incoming EOF but haven't sent an + * outgoing one, this may be the moment to send it. + */ + if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF)) + sshfwd_write_eof(c); +} + +/* + * Client-initiated disconnection. Send a DISCONNECT if `wire_reason' + * non-NULL, otherwise just close the connection. `client_reason' == NULL + * => log `wire_reason'. + */ +static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason, + int code, int clean_exit) +{ + char *error; + if (!client_reason) + client_reason = wire_reason; + if (client_reason) + error = dupprintf("Disconnected: %s", client_reason); + else + error = dupstr("Disconnected"); + if (wire_reason) { + if (ssh->version == 1) { + send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason, + PKT_END); + } else if (ssh->version == 2) { + struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); + ssh2_pkt_adduint32(pktout, code); + ssh2_pkt_addstring(pktout, wire_reason); + ssh2_pkt_addstring(pktout, "en"); /* language tag */ + ssh2_pkt_send_noqueue(ssh, pktout); + } + } + ssh->close_expected = TRUE; + ssh->clean_exit = clean_exit; + ssh_closing((Plug)ssh, error, 0, 0); + sfree(error); } /* * Handle the key exchange and user authentication phases. */ -static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) +static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin) { - int i, j; - unsigned char cookie[8]; - struct RSAKey servkey, hostkey; + int i, j, ret; + unsigned char cookie[8], *ptr; struct MD5Context md5c; struct do_ssh1_login_state { + int crLine; int len; unsigned char *rsabuf, *keystr1, *keystr2; unsigned long supported_ciphers_mask, supported_auths_mask; @@ -2354,12 +3296,11 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) int tis_auth_refused, ccard_auth_refused; unsigned char session_id[16]; int cipher_type; - char username[100]; void *publickey_blob; int publickey_bloblen; - char password[100]; - char prompt[200]; - int pos; + char *publickey_comment; + int publickey_encrypted; + prompts_t *cur_prompt; char c; int pwpkt_type; unsigned char request[5], *response, *p; @@ -2370,25 +3311,36 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) Bignum challenge; char *commentp; int commentlen; + int dlgret; + Filename *keyfile; + struct RSAKey servkey, hostkey; }; crState(do_ssh1_login_state); - crBegin(ssh->do_ssh1_login_crstate); + crBeginState; - if (!ispkt) - crWaitUntil(ispkt); + if (!pktin) + crWaitUntil(pktin); - if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) { + if (pktin->type != SSH1_SMSG_PUBLIC_KEY) { bombout(("Public key packet not received")); crStop(0); } logevent("Received public keys"); - memcpy(cookie, ssh->pktin.body, 8); + ptr = ssh_pkt_getdata(pktin, 8); + if (!ptr) { + bombout(("SSH-1 public key packet stopped before random cookie")); + crStop(0); + } + memcpy(cookie, ptr, 8); - i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0); - j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0); + if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) || + !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) { + bombout(("Failed to read SSH-1 public keys from public key packet")); + crStop(0); + } /* * Log the host key fingerprint. @@ -2397,34 +3349,44 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) char logmsg[80]; logevent("Host key fingerprint is:"); strcpy(logmsg, " "); - hostkey.comment = NULL; + s->hostkey.comment = NULL; rsa_fingerprint(logmsg + strlen(logmsg), - sizeof(logmsg) - strlen(logmsg), &hostkey); + sizeof(logmsg) - strlen(logmsg), &s->hostkey); logevent(logmsg); } - ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j); - s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j); - s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j); + ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin); + s->supported_ciphers_mask = ssh_pkt_getuint32(pktin); + s->supported_auths_mask = ssh_pkt_getuint32(pktin); + if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) + s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA); ssh->v1_local_protoflags = ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; MD5Init(&md5c); - MD5Update(&md5c, s->keystr2, hostkey.bytes); - MD5Update(&md5c, s->keystr1, servkey.bytes); - MD5Update(&md5c, ssh->pktin.body, 8); + MD5Update(&md5c, s->keystr2, s->hostkey.bytes); + MD5Update(&md5c, s->keystr1, s->servkey.bytes); + MD5Update(&md5c, cookie, 8); MD5Final(s->session_id, &md5c); for (i = 0; i < 32; i++) ssh->session_key[i] = random_byte(); - s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); + /* + * Verify that the `bits' and `bytes' parameters match. + */ + if (s->hostkey.bits > s->hostkey.bytes * 8 || + s->servkey.bits > s->servkey.bytes * 8) { + bombout(("SSH-1 public keys were badly formatted")); + crStop(0); + } + + s->len = (s->hostkey.bytes > s->servkey.bytes ? + s->hostkey.bytes : s->servkey.bytes); s->rsabuf = snewn(s->len, unsigned char); - if (!s->rsabuf) - fatalbox("Out of memory"); /* * Verify the host key. @@ -2433,17 +3395,36 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) /* * First format the key into a string. */ - int len = rsastr_len(&hostkey); + int len = rsastr_len(&s->hostkey); char fingerprint[100]; char *keystr = snewn(len, char); - if (!keystr) - fatalbox("Out of memory"); - rsastr_fmt(keystr, &hostkey); - rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); - verify_ssh_host_key(ssh->frontend, - ssh->savedhost, ssh->savedport, "rsa", keystr, - fingerprint); + rsastr_fmt(keystr, &s->hostkey); + rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey); + + ssh_set_frozen(ssh, 1); + s->dlgret = verify_ssh_host_key(ssh->frontend, + ssh->savedhost, ssh->savedport, + "rsa", keystr, fingerprint, + ssh_dialog_callback, ssh); sfree(keystr); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user host key response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at host key verification", + NULL, 0, TRUE); + crStop(0); + } } for (i = 0; i < 32; i++) { @@ -2452,12 +3433,18 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) s->rsabuf[i] ^= s->session_id[i]; } - if (hostkey.bytes > servkey.bytes) { - rsaencrypt(s->rsabuf, 32, &servkey); - rsaencrypt(s->rsabuf, servkey.bytes, &hostkey); + if (s->hostkey.bytes > s->servkey.bytes) { + ret = rsaencrypt(s->rsabuf, 32, &s->servkey); + if (ret) + ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey); } else { - rsaencrypt(s->rsabuf, 32, &hostkey); - rsaencrypt(s->rsabuf, hostkey.bytes, &servkey); + ret = rsaencrypt(s->rsabuf, 32, &s->hostkey); + if (ret) + ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey); + } + if (!ret) { + bombout(("SSH-1 public key encryptions failed due to bad formatting")); + crStop(0); } logevent("Encrypted session key"); @@ -2467,13 +3454,14 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) char *cipher_string = NULL; int i; for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { - int next_cipher = ssh->cfg.ssh_cipherlist[i]; + int next_cipher = conf_get_int_int(ssh->conf, + CONF_ssh_cipherlist, i); if (next_cipher == CIPHER_WARN) { /* If/when we choose a cipher, warn about it */ warn = 1; } else if (next_cipher == CIPHER_AES) { /* XXX Probably don't need to mention this. */ - logevent("AES not supported in SSH1, skipping"); + logevent("AES not supported in SSH-1, skipping"); } else { switch (next_cipher) { case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES; @@ -2489,7 +3477,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) } if (!cipher_chosen) { if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) - bombout(("Server violates SSH 1 protocol by not " + bombout(("Server violates SSH-1 protocol by not " "supporting 3DES encryption")); else /* shouldn't happen */ @@ -2498,8 +3486,28 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) } /* Warn about chosen cipher if necessary. */ - if (warn) - askcipher(ssh->frontend, cipher_string, 0); + if (warn) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, "cipher", cipher_string, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at cipher warning", NULL, + 0, TRUE); + crStop(0); + } + } } switch (s->cipher_type) { @@ -2535,82 +3543,126 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) ssh->crcda_ctx = crcda_make_context(); logevent("Installing CRC compensation attack detector"); - crWaitUntil(ispkt); + if (s->servkey.modulus) { + sfree(s->servkey.modulus); + s->servkey.modulus = NULL; + } + if (s->servkey.exponent) { + sfree(s->servkey.exponent); + s->servkey.exponent = NULL; + } + if (s->hostkey.modulus) { + sfree(s->hostkey.modulus); + s->hostkey.modulus = NULL; + } + if (s->hostkey.exponent) { + sfree(s->hostkey.exponent); + s->hostkey.exponent = NULL; + } + crWaitUntil(pktin); - if (ssh->pktin.type != SSH1_SMSG_SUCCESS) { + if (pktin->type != SSH1_SMSG_SUCCESS) { bombout(("Encryption not successfully enabled")); crStop(0); } logevent("Successfully started encryption"); - fflush(stdout); + fflush(stdout); /* FIXME eh? */ { - if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) { - if (ssh_get_line && !ssh_getline_pw_only) { - if (!ssh_get_line("login as: ", - s->username, sizeof(s->username), FALSE)) { - /* - * get_line failed to get a username. - * Terminate. - */ - logevent("No username provided. Abandoning session."); - ssh_closing((Plug)ssh, NULL, 0, 0); - crStop(1); - } - } else { - int ret; /* need not be kept over crReturn */ - c_write_str(ssh, "login as: "); + if ((ssh->username = get_remote_username(ssh->conf)) == NULL) { + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH login name"); + add_prompt(s->cur_prompt, dupstr("login as: "), TRUE); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { ssh->send_ok = 1; - - setup_userpass_input(ssh, s->username, sizeof(s->username), 1); - do { - crWaitUntil(!ispkt); - ret = process_userpass_input(ssh, in, inlen); - } while (ret == 0); - if (ret < 0) - cleanup_exit(0); - c_write_str(ssh, "\r\n"); + crWaitUntil(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; } - } else { - strncpy(s->username, ssh->cfg.username, sizeof(s->username)); - s->username[sizeof(s->username)-1] = '\0'; + if (!ret) { + /* + * Failed to get a username. Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); + crStop(0); + } + ssh->username = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); } - send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END); + send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END); { - char userlog[22 + sizeof(s->username)]; - sprintf(userlog, "Sent username \"%s\"", s->username); + char *userlog = dupprintf("Sent username \"%s\"", ssh->username); logevent(userlog); if (flags & FLAG_INTERACTIVE && (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { - strcat(userlog, "\r\n"); c_write_str(ssh, userlog); + c_write_str(ssh, "\r\n"); } + sfree(userlog); } } - crWaitUntil(ispkt); + crWaitUntil(pktin); - if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) { + if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) { /* We must not attempt PK auth. Pretend we've already tried it. */ s->tried_publickey = s->tried_agent = 1; } else { s->tried_publickey = s->tried_agent = 0; } s->tis_auth_refused = s->ccard_auth_refused = 0; - /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */ - if (!filename_is_null(ssh->cfg.keyfile)) { - if (!rsakey_pubblob(&ssh->cfg.keyfile, - &s->publickey_blob, &s->publickey_bloblen, NULL)) + /* + * Load the public half of any configured keyfile for later use. + */ + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + if (!filename_is_null(s->keyfile)) { + int keytype; + logeventf(ssh, "Reading private key file \"%.150s\"", + filename_to_str(s->keyfile)); + keytype = key_type(s->keyfile); + if (keytype == SSH_KEYTYPE_SSH1) { + const char *error; + if (rsakey_pubblob(s->keyfile, + &s->publickey_blob, &s->publickey_bloblen, + &s->publickey_comment, &error)) { + s->publickey_encrypted = rsakey_encrypted(s->keyfile, + NULL); + } else { + char *msgbuf; + logeventf(ssh, "Unable to load private key (%s)", error); + msgbuf = dupprintf("Unable to load private key file " + "\"%.150s\" (%s)\r\n", + filename_to_str(s->keyfile), + error); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + s->publickey_blob = NULL; + } + } else { + char *msgbuf; + logeventf(ssh, "Unable to use this key file (%s)", + key_type_to_str(keytype)); + msgbuf = dupprintf("Unable to use key file \"%.150s\"" + " (%s)\r\n", + filename_to_str(s->keyfile), + key_type_to_str(keytype)); + c_write_str(ssh, msgbuf); + sfree(msgbuf); s->publickey_blob = NULL; + } } else s->publickey_blob = NULL; - while (ssh->pktin.type == SSH1_SMSG_FAILURE) { + while (pktin->type == SSH1_SMSG_FAILURE) { s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; - if (agent_exists() && !s->tried_agent) { + if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) { /* * Attempt RSA authentication using Pageant. */ @@ -2627,12 +3679,12 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) ssh_agent_callback, ssh)) { do { crReturn(0); - if (ispkt) { + if (pktin) { bombout(("Unexpected data from server while waiting" " for agent response")); crStop(0); } - } while (ispkt || inlen > 0); + } while (pktin || inlen > 0); r = ssh->agent_response; s->responselen = ssh->agent_response_len; } @@ -2640,41 +3692,73 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) if (s->response && s->responselen >= 5 && s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { s->p = s->response + 5; - s->nkeys = GET_32BIT(s->p); + s->nkeys = toint(GET_32BIT(s->p)); + if (s->nkeys < 0) { + logeventf(ssh, "Pageant reported negative key count %d", + s->nkeys); + s->nkeys = 0; + } s->p += 4; - { - char buf[64]; - sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys); - logevent(buf); - } + logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys); for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { + unsigned char *pkblob = s->p; + s->p += 4; { - char buf[64]; - sprintf(buf, "Trying Pageant key #%d", s->keyi); - logevent(buf); + int n, ok = FALSE; + do { /* do while (0) to make breaking easy */ + n = ssh1_read_bignum + (s->p, toint(s->responselen-(s->p-s->response)), + &s->key.exponent); + if (n < 0) + break; + s->p += n; + n = ssh1_read_bignum + (s->p, toint(s->responselen-(s->p-s->response)), + &s->key.modulus); + if (n < 0) + break; + s->p += n; + if (s->responselen - (s->p-s->response) < 4) + break; + s->commentlen = toint(GET_32BIT(s->p)); + s->p += 4; + if (s->commentlen < 0 || + toint(s->responselen - (s->p-s->response)) < + s->commentlen) + break; + s->commentp = (char *)s->p; + s->p += s->commentlen; + ok = TRUE; + } while (0); + if (!ok) { + logevent("Pageant key list packet was truncated"); + break; + } } - if (s->publickey_blob && - !memcmp(s->p, s->publickey_blob, - s->publickey_bloblen)) { - logevent("This key matches configured key file"); - s->tried_publickey = 1; + if (s->publickey_blob) { + if (!memcmp(pkblob, s->publickey_blob, + s->publickey_bloblen)) { + logeventf(ssh, "Pageant key #%d matches " + "configured key file", s->keyi); + s->tried_publickey = 1; + } else + /* Skip non-configured key */ + continue; } - s->p += 4; - s->p += ssh1_read_bignum(s->p, &s->key.exponent); - s->p += ssh1_read_bignum(s->p, &s->key.modulus); - s->commentlen = GET_32BIT(s->p); - s->p += 4; - s->commentp = (char *)s->p; - s->p += s->commentlen; + logeventf(ssh, "Trying Pageant key #%d", s->keyi); send_packet(ssh, SSH1_CMSG_AUTH_RSA, PKT_BIGNUM, s->key.modulus, PKT_END); - crWaitUntil(ispkt); - if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { + crWaitUntil(pktin); + if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { logevent("Key refused"); continue; } logevent("Received RSA challenge"); - ssh1_read_bignum(ssh->pktin.body, &s->challenge); + if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) { + bombout(("Server's RSA challenge was badly formatted")); + crStop(0); + } + { char *agentreq, *q, *ret; void *vret; @@ -2702,13 +3786,13 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) sfree(agentreq); do { crReturn(0); - if (ispkt) { + if (pktin) { bombout(("Unexpected data from server" " while waiting for agent" " response")); crStop(0); } - } while (ispkt || inlen > 0); + } while (pktin || inlen > 0); vret = ssh->agent_response; retlen = ssh->agent_response_len; } else @@ -2721,8 +3805,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) PKT_DATA, ret + 5, 16, PKT_END); sfree(ret); - crWaitUntil(ispkt); - if (ssh->pktin.type == SSH1_SMSG_SUCCESS) { + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_SUCCESS) { logevent ("Pageant's response accepted"); if (flags & FLAG_VERBOSE) { @@ -2751,94 +3835,257 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) if (s->authed) break; } - } + sfree(s->response); + if (s->publickey_blob && !s->tried_publickey) + logevent("Configured key file not in Pageant"); + } else { + logevent("Failed to get reply from Pageant"); + } if (s->authed) break; } - if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey) - s->pwpkt_type = SSH1_CMSG_AUTH_RSA; + if (s->publickey_blob && !s->tried_publickey) { + /* + * Try public key authentication with the specified + * key file. + */ + int got_passphrase; /* need not be kept over crReturn */ + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "Trying public key authentication.\r\n"); + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + logeventf(ssh, "Trying public key \"%s\"", + filename_to_str(s->keyfile)); + s->tried_publickey = 1; + got_passphrase = FALSE; + while (!got_passphrase) { + /* + * Get a passphrase, if necessary. + */ + char *passphrase = NULL; /* only written after crReturn */ + const char *error; + if (!s->publickey_encrypted) { + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "No passphrase required.\r\n"); + passphrase = NULL; + } else { + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = FALSE; + s->cur_prompt->name = dupstr("SSH key passphrase"); + add_prompt(s->cur_prompt, + dupprintf("Passphrase for key \"%.100s\": ", + s->publickey_comment), FALSE); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntil(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* Failed to get a passphrase. Terminate. */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + 0, TRUE); + crStop(0); + } + passphrase = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + } + /* + * Try decrypting key with passphrase. + */ + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + ret = loadrsakey(s->keyfile, &s->key, passphrase, + &error); + if (passphrase) { + smemclr(passphrase, strlen(passphrase)); + sfree(passphrase); + } + if (ret == 1) { + /* Correct passphrase. */ + got_passphrase = TRUE; + } else if (ret == 0) { + c_write_str(ssh, "Couldn't load private key from "); + c_write_str(ssh, filename_to_str(s->keyfile)); + c_write_str(ssh, " ("); + c_write_str(ssh, error); + c_write_str(ssh, ").\r\n"); + got_passphrase = FALSE; + break; /* go and try something else */ + } else if (ret == -1) { + c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */ + got_passphrase = FALSE; + /* and try again */ + } else { + assert(0 && "unexpected return from loadrsakey()"); + got_passphrase = FALSE; /* placate optimisers */ + } + } + + if (got_passphrase) { + + /* + * Send a public key attempt. + */ + send_packet(ssh, SSH1_CMSG_AUTH_RSA, + PKT_BIGNUM, s->key.modulus, PKT_END); + + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_FAILURE) { + c_write_str(ssh, "Server refused our public key.\r\n"); + continue; /* go and try something else */ + } + if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { + bombout(("Bizarre response to offer of public key")); + crStop(0); + } + + { + int i; + unsigned char buffer[32]; + Bignum challenge, response; + + if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) { + bombout(("Server's RSA challenge was badly formatted")); + crStop(0); + } + response = rsadecrypt(challenge, &s->key); + freebn(s->key.private_exponent);/* burn the evidence */ + + for (i = 0; i < 32; i++) { + buffer[i] = bignum_byte(response, 31 - i); + } + + MD5Init(&md5c); + MD5Update(&md5c, buffer, 32); + MD5Update(&md5c, s->session_id, 16); + MD5Final(buffer, &md5c); + + send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, + PKT_DATA, buffer, 16, PKT_END); + + freebn(challenge); + freebn(response); + } + + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_FAILURE) { + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "Failed to authenticate with" + " our public key.\r\n"); + continue; /* go and try something else */ + } else if (pktin->type != SSH1_SMSG_SUCCESS) { + bombout(("Bizarre response to RSA authentication response")); + crStop(0); + } + + break; /* we're through! */ + } + + } - if (ssh->cfg.try_tis_auth && + /* + * Otherwise, try various forms of password-like authentication. + */ + s->cur_prompt = new_prompts(ssh->frontend); + + if (conf_get_int(ssh->conf, CONF_try_tis_auth) && (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) && !s->tis_auth_refused) { s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; logevent("Requested TIS authentication"); send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END); - crWaitUntil(ispkt); - if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { + crWaitUntil(pktin); + if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { logevent("TIS authentication declined"); if (flags & FLAG_INTERACTIVE) c_write_str(ssh, "TIS authentication refused.\r\n"); s->tis_auth_refused = 1; continue; } else { - int challengelen = GET_32BIT(ssh->pktin.body); + char *challenge; + int challengelen; + char *instr_suf, *prompt; + + ssh_pkt_getstring(pktin, &challenge, &challengelen); + if (!challenge) { + bombout(("TIS challenge packet was badly formed")); + crStop(0); + } logevent("Received TIS challenge"); - if (challengelen > sizeof(s->prompt) - 1) - challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ - memcpy(s->prompt, ssh->pktin.body + 4, challengelen); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH TIS authentication"); /* Prompt heuristic comes from OpenSSH */ - strncpy(s->prompt + challengelen, - memchr(s->prompt, '\n', challengelen) ? - "": "\r\nResponse: ", - (sizeof s->prompt) - challengelen); - s->prompt[(sizeof s->prompt) - 1] = '\0'; + if (memchr(challenge, '\n', challengelen)) { + instr_suf = dupstr(""); + prompt = dupprintf("%.*s", challengelen, challenge); + } else { + instr_suf = dupprintf("%.*s", challengelen, challenge); + prompt = dupstr("Response: "); + } + s->cur_prompt->instruction = + dupprintf("Using TIS authentication.%s%s", + (*instr_suf) ? "\n" : "", + instr_suf); + s->cur_prompt->instr_reqd = TRUE; + add_prompt(s->cur_prompt, prompt, FALSE); + sfree(instr_suf); } } - if (ssh->cfg.try_tis_auth && + if (conf_get_int(ssh->conf, CONF_try_tis_auth) && (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) && !s->ccard_auth_refused) { s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; logevent("Requested CryptoCard authentication"); send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END); - crWaitUntil(ispkt); - if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { + crWaitUntil(pktin); + if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { logevent("CryptoCard authentication declined"); c_write_str(ssh, "CryptoCard authentication refused.\r\n"); s->ccard_auth_refused = 1; continue; } else { - int challengelen = GET_32BIT(ssh->pktin.body); + char *challenge; + int challengelen; + char *instr_suf, *prompt; + + ssh_pkt_getstring(pktin, &challenge, &challengelen); + if (!challenge) { + bombout(("CryptoCard challenge packet was badly formed")); + crStop(0); + } logevent("Received CryptoCard challenge"); - if (challengelen > sizeof(s->prompt) - 1) - challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ - memcpy(s->prompt, ssh->pktin.body + 4, challengelen); - strncpy(s->prompt + challengelen, - memchr(s->prompt, '\n', challengelen) ? - "" : "\r\nResponse: ", - sizeof(s->prompt) - challengelen); - s->prompt[sizeof(s->prompt) - 1] = '\0'; + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH CryptoCard authentication"); + s->cur_prompt->name_reqd = FALSE; + /* Prompt heuristic comes from OpenSSH */ + if (memchr(challenge, '\n', challengelen)) { + instr_suf = dupstr(""); + prompt = dupprintf("%.*s", challengelen, challenge); + } else { + instr_suf = dupprintf("%.*s", challengelen, challenge); + prompt = dupstr("Response: "); + } + s->cur_prompt->instruction = + dupprintf("Using CryptoCard authentication.%s%s", + (*instr_suf) ? "\n" : "", + instr_suf); + s->cur_prompt->instr_reqd = TRUE; + add_prompt(s->cur_prompt, prompt, FALSE); + sfree(instr_suf); } } if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { - sprintf(s->prompt, "%.90s@%.90s's password: ", - s->username, ssh->savedhost); - } - if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) { - char *comment = NULL; - int type; - char msgbuf[256]; - if (flags & FLAG_VERBOSE) - c_write_str(ssh, "Trying public key authentication.\r\n"); - logeventf(ssh, "Trying public key \"%s\"", - filename_to_str(&ssh->cfg.keyfile)); - type = key_type(&ssh->cfg.keyfile); - if (type != SSH_KEYTYPE_SSH1) { - sprintf(msgbuf, "Key is of wrong type (%s)", - key_type_to_str(type)); - logevent(msgbuf); - c_write_str(ssh, msgbuf); - c_write_str(ssh, "\r\n"); - s->tried_publickey = 1; - continue; - } - if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) { - if (flags & FLAG_VERBOSE) - c_write_str(ssh, "No passphrase required.\r\n"); - goto tryauth; + if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) { + bombout(("No supported authentication methods available")); + crStop(0); } - sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment); - sfree(comment); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH password"); + add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ", + ssh->username, ssh->savedhost), + FALSE); } /* @@ -2846,311 +4093,250 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) * or CryptoCard exchange if we're doing TIS or CryptoCard * authentication. */ - if (ssh_get_line) { - if (!ssh_get_line(s->prompt, s->password, - sizeof(s->password), TRUE)) { + { + int ret; /* need not be kept over crReturn */ + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntil(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { /* - * get_line failed to get a password (for example + * Failed to get a password (for example * because one was supplied on the command line * which has already failed to work). Terminate. */ - send_packet(ssh, SSH1_MSG_DISCONNECT, - PKT_STR, "No more passwords available to try", - PKT_END); - logevent("Unable to authenticate"); - connection_fatal(ssh->frontend, "Unable to authenticate"); - ssh_closing((Plug)ssh, NULL, 0, 0); - crStop(1); + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE); + crStop(0); } - } else { - /* Prompt may have come from server. We've munged it a bit, so - * we know it to be zero-terminated at least once. */ - int ret; /* need not be saved over crReturn */ - c_write_untrusted(ssh, s->prompt, strlen(s->prompt)); - s->pos = 0; - - setup_userpass_input(ssh, s->password, sizeof(s->password), 0); - do { - crWaitUntil(!ispkt); - ret = process_userpass_input(ssh, in, inlen); - } while (ret == 0); - if (ret < 0) - cleanup_exit(0); - c_write_str(ssh, "\r\n"); } - tryauth: - if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) { - /* - * Try public key authentication with the specified - * key file. - */ - s->tried_publickey = 1; - - { - const char *error = NULL; - int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password, - &error); - if (ret == 0) { - c_write_str(ssh, "Couldn't load private key from "); - c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile)); - c_write_str(ssh, " ("); - c_write_str(ssh, error); - c_write_str(ssh, ").\r\n"); - continue; /* go and try password */ - } - if (ret == -1) { - c_write_str(ssh, "Wrong passphrase.\r\n"); - s->tried_publickey = 0; - continue; /* try again */ - } - } - + if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { /* - * Send a public key attempt. + * Defence against traffic analysis: we send a + * whole bunch of packets containing strings of + * different lengths. One of these strings is the + * password, in a SSH1_CMSG_AUTH_PASSWORD packet. + * The others are all random data in + * SSH1_MSG_IGNORE packets. This way a passive + * listener can't tell which is the password, and + * hence can't deduce the password length. + * + * Anybody with a password length greater than 16 + * bytes is going to have enough entropy in their + * password that a listener won't find it _that_ + * much help to know how long it is. So what we'll + * do is: + * + * - if password length < 16, we send 15 packets + * containing string lengths 1 through 15 + * + * - otherwise, we let N be the nearest multiple + * of 8 below the password length, and send 8 + * packets containing string lengths N through + * N+7. This won't obscure the order of + * magnitude of the password length, but it will + * introduce a bit of extra uncertainty. + * + * A few servers can't deal with SSH1_MSG_IGNORE, at + * least in this context. For these servers, we need + * an alternative defence. We make use of the fact + * that the password is interpreted as a C string: + * so we can append a NUL, then some random data. + * + * A few servers can deal with neither SSH1_MSG_IGNORE + * here _nor_ a padded password string. + * For these servers we are left with no defences + * against password length sniffing. */ - send_packet(ssh, SSH1_CMSG_AUTH_RSA, - PKT_BIGNUM, s->key.modulus, PKT_END); - - crWaitUntil(ispkt); - if (ssh->pktin.type == SSH1_SMSG_FAILURE) { - c_write_str(ssh, "Server refused our public key.\r\n"); - continue; /* go and try password */ - } - if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { - bombout(("Bizarre response to offer of public key")); - crStop(0); - } - - { - int i; - unsigned char buffer[32]; - Bignum challenge, response; - - ssh1_read_bignum(ssh->pktin.body, &challenge); - response = rsadecrypt(challenge, &s->key); - freebn(s->key.private_exponent);/* burn the evidence */ + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) && + !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { + /* + * The server can deal with SSH1_MSG_IGNORE, so + * we can use the primary defence. + */ + int bottom, top, pwlen, i; + char *randomstr; - for (i = 0; i < 32; i++) { - buffer[i] = bignum_byte(response, 31 - i); + pwlen = strlen(s->cur_prompt->prompts[0]->result); + if (pwlen < 16) { + bottom = 0; /* zero length passwords are OK! :-) */ + top = 15; + } else { + bottom = pwlen & ~7; + top = bottom + 7; } - MD5Init(&md5c); - MD5Update(&md5c, buffer, 32); - MD5Update(&md5c, s->session_id, 16); - MD5Final(buffer, &md5c); - - send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, - PKT_DATA, buffer, 16, PKT_END); - - freebn(challenge); - freebn(response); - } + assert(pwlen >= bottom && pwlen <= top); - crWaitUntil(ispkt); - if (ssh->pktin.type == SSH1_SMSG_FAILURE) { - if (flags & FLAG_VERBOSE) - c_write_str(ssh, "Failed to authenticate with" - " our public key.\r\n"); - continue; /* go and try password */ - } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) { - bombout(("Bizarre response to RSA authentication response")); - crStop(0); - } + randomstr = snewn(top + 1, char); - break; /* we're through! */ - } else { - if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { - /* - * Defence against traffic analysis: we send a - * whole bunch of packets containing strings of - * different lengths. One of these strings is the - * password, in a SSH1_CMSG_AUTH_PASSWORD packet. - * The others are all random data in - * SSH1_MSG_IGNORE packets. This way a passive - * listener can't tell which is the password, and - * hence can't deduce the password length. - * - * Anybody with a password length greater than 16 - * bytes is going to have enough entropy in their - * password that a listener won't find it _that_ - * much help to know how long it is. So what we'll - * do is: - * - * - if password length < 16, we send 15 packets - * containing string lengths 1 through 15 - * - * - otherwise, we let N be the nearest multiple - * of 8 below the password length, and send 8 - * packets containing string lengths N through - * N+7. This won't obscure the order of - * magnitude of the password length, but it will - * introduce a bit of extra uncertainty. - * - * A few servers (the old 1.2.18 through 1.2.22) - * can't deal with SSH1_MSG_IGNORE. For these - * servers, we need an alternative defence. We make - * use of the fact that the password is interpreted - * as a C string: so we can append a NUL, then some - * random data. - * - * One server (a Cisco one) can deal with neither - * SSH1_MSG_IGNORE _nor_ a padded password string. - * For this server we are left with no defences - * against password length sniffing. - */ - if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) { - /* - * The server can deal with SSH1_MSG_IGNORE, so - * we can use the primary defence. - */ - int bottom, top, pwlen, i; - char *randomstr; - - pwlen = strlen(s->password); - if (pwlen < 16) { - bottom = 0; /* zero length passwords are OK! :-) */ - top = 15; + for (i = bottom; i <= top; i++) { + if (i == pwlen) { + defer_packet(ssh, s->pwpkt_type, + PKTT_PASSWORD, PKT_STR, + s->cur_prompt->prompts[0]->result, + PKTT_OTHER, PKT_END); } else { - bottom = pwlen & ~7; - top = bottom + 7; - } - - assert(pwlen >= bottom && pwlen <= top); - - randomstr = snewn(top + 1, char); - - for (i = bottom; i <= top; i++) { - if (i == pwlen) - defer_packet(ssh, s->pwpkt_type, - PKT_STR, s->password, PKT_END); - else { - for (j = 0; j < i; j++) { - do { - randomstr[j] = random_byte(); - } while (randomstr[j] == '\0'); - } - randomstr[i] = '\0'; - defer_packet(ssh, SSH1_MSG_IGNORE, - PKT_STR, randomstr, PKT_END); + for (j = 0; j < i; j++) { + do { + randomstr[j] = random_byte(); + } while (randomstr[j] == '\0'); } + randomstr[i] = '\0'; + defer_packet(ssh, SSH1_MSG_IGNORE, + PKT_STR, randomstr, PKT_END); } - logevent("Sending password with camouflage packets"); - ssh_pkt_defersend(ssh); - } - else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { - /* - * The server can't deal with SSH1_MSG_IGNORE - * but can deal with padded passwords, so we - * can use the secondary defence. - */ - char string[64]; - char *ss; - int len; - - len = strlen(s->password); - if (len < sizeof(string)) { - ss = string; - strcpy(string, s->password); - len++; /* cover the zero byte */ - while (len < sizeof(string)) { - string[len++] = (char) random_byte(); - } - } else { - ss = s->password; + } + logevent("Sending password with camouflage packets"); + ssh_pkt_defersend(ssh); + sfree(randomstr); + } + else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { + /* + * The server can't deal with SSH1_MSG_IGNORE + * but can deal with padded passwords, so we + * can use the secondary defence. + */ + char string[64]; + char *ss; + int len; + + len = strlen(s->cur_prompt->prompts[0]->result); + if (len < sizeof(string)) { + ss = string; + strcpy(string, s->cur_prompt->prompts[0]->result); + len++; /* cover the zero byte */ + while (len < sizeof(string)) { + string[len++] = (char) random_byte(); } - logevent("Sending length-padded password"); - send_packet(ssh, s->pwpkt_type, PKT_INT, len, - PKT_DATA, ss, len, PKT_END); } else { - /* - * The server has _both_ - * BUG_CHOKES_ON_SSH1_IGNORE and - * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is - * therefore nothing we can do. - */ - int len; - len = strlen(s->password); - logevent("Sending unpadded password"); - send_packet(ssh, s->pwpkt_type, PKT_INT, len, - PKT_DATA, s->password, len, PKT_END); + ss = s->cur_prompt->prompts[0]->result; } + logevent("Sending length-padded password"); + send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, + PKT_INT, len, PKT_DATA, ss, len, + PKTT_OTHER, PKT_END); } else { - send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END); + /* + * The server is believed unable to cope with + * any of our password camouflage methods. + */ + int len; + len = strlen(s->cur_prompt->prompts[0]->result); + logevent("Sending unpadded password"); + send_packet(ssh, s->pwpkt_type, + PKTT_PASSWORD, PKT_INT, len, + PKT_DATA, s->cur_prompt->prompts[0]->result, len, + PKTT_OTHER, PKT_END); } + } else { + send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, + PKT_STR, s->cur_prompt->prompts[0]->result, + PKTT_OTHER, PKT_END); } logevent("Sent password"); - memset(s->password, 0, strlen(s->password)); - crWaitUntil(ispkt); - if (ssh->pktin.type == SSH1_SMSG_FAILURE) { + free_prompts(s->cur_prompt); + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_FAILURE) { if (flags & FLAG_VERBOSE) c_write_str(ssh, "Access denied\r\n"); logevent("Authentication refused"); - } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) { - bombout(("Strange packet received, type %d", ssh->pktin.type)); + } else if (pktin->type != SSH1_SMSG_SUCCESS) { + bombout(("Strange packet received, type %d", pktin->type)); crStop(0); } } + /* Clear up */ + if (s->publickey_blob) { + sfree(s->publickey_blob); + sfree(s->publickey_comment); + } + logevent("Authentication successful"); crFinish(1); } -void sshfwd_close(struct ssh_channel *c) +static void ssh_channel_try_eof(struct ssh_channel *c) { Ssh ssh = c->ssh; + assert(c->pending_eof); /* precondition for calling us */ + if (c->halfopen) + return; /* can't close: not even opened yet */ + if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0) + return; /* can't send EOF: pending outgoing data */ - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); - return; + c->pending_eof = FALSE; /* we're about to send it */ + if (ssh->version == 1) { + send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, + PKT_END); + c->closes |= CLOSES_SENT_EOF; + } else { + struct Packet *pktout; + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + c->closes |= CLOSES_SENT_EOF; + ssh2_channel_check_close(c); } +} - if (c && !c->closes) { - /* - * If the channel's remoteid is -1, we have sent - * CHANNEL_OPEN for this channel, but it hasn't even been - * acknowledged by the server. So we must set a close flag - * on it now, and then when the server acks the channel - * open, we can close it then. - */ - if (((int)c->remoteid) != -1) { - if (ssh->version == 1) { - send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, - PKT_END); - } else { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE); - ssh2_pkt_adduint32(ssh, c->remoteid); - ssh2_pkt_send(ssh); - } - } - c->closes = 1; /* sent MSG_CLOSE */ - if (c->type == CHAN_X11) { - c->u.x11.s = NULL; - logevent("Forwarded X11 connection terminated"); - } else if (c->type == CHAN_SOCKDATA || - c->type == CHAN_SOCKDATA_DORMANT) { - c->u.pfd.s = NULL; - logevent("Forwarded port closed"); - } +void sshfwd_write_eof(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (c->closes & CLOSES_SENT_EOF) + return; + + c->pending_eof = TRUE; + ssh_channel_try_eof(c); +} + +void sshfwd_unclean_close(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + + if (ssh->state == SSH_STATE_CLOSED) + return; + + switch (c->type) { + case CHAN_X11: + x11_close(c->u.x11.s); + logevent("Forwarded X11 connection terminated due to local error"); + break; + case CHAN_SOCKDATA: + case CHAN_SOCKDATA_DORMANT: + pfd_close(c->u.pfd.s); + logevent("Forwarded port closed due to local error"); + break; } + c->type = CHAN_ZOMBIE; + + ssh2_channel_check_close(c); } int sshfwd_write(struct ssh_channel *c, char *buf, int len) { Ssh ssh = c->ssh; - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); + if (ssh->state == SSH_STATE_CLOSED) return 0; - } if (ssh->version == 1) { send_packet(ssh, SSH1_MSG_CHANNEL_DATA, PKT_INT, c->remoteid, - PKT_INT, len, PKT_DATA, buf, len, PKT_END); + PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len, + PKTT_OTHER, PKT_END); /* - * In SSH1 we can return 0 here - implying that forwarded + * In SSH-1 we can return 0 here - implying that forwarded * connections are never individually throttled - because * the only circumstance that can cause throttling will be * the whole SSH connection backing up, in which case @@ -3166,603 +4352,994 @@ int sshfwd_write(struct ssh_channel *c, char *buf, int len) void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) { Ssh ssh = c->ssh; + int buflimit; - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); + if (ssh->state == SSH_STATE_CLOSED) return; - } if (ssh->version == 1) { - if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) { - c->v.v1.throttling = 0; - ssh1_throttle(ssh, -1); - } + buflimit = SSH1_BUFFER_LIMIT; } else { - ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); + buflimit = c->v.v2.locmaxwin; + ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0); + } + if (c->throttling_conn && bufsize <= buflimit) { + c->throttling_conn = 0; + ssh_throttle_conn(ssh, -1); } } -static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt) +static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin) { - crBegin(ssh->ssh1_protocol_crstate); + struct queued_handler *qh = ssh->qhead; - random_init(); + assert(qh != NULL); - while (!do_ssh1_login(ssh, in, inlen, ispkt)) { - crReturnV; + assert(pktin->type == qh->msg1 || pktin->type == qh->msg2); + + if (qh->msg1 > 0) { + assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler); + ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1; + } + if (qh->msg2 > 0) { + assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler); + ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2; } - if (ssh->state == SSH_STATE_CLOSED) - crReturnV; - if (ssh->cfg.agentfwd && agent_exists()) { - logevent("Requesting agent forwarding"); - send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); - do { - crReturnV; - } while (!ispkt); - if (ssh->pktin.type != SSH1_SMSG_SUCCESS - && ssh->pktin.type != SSH1_SMSG_FAILURE) { - bombout(("Protocol confusion")); - crStopV; - } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { - logevent("Agent forwarding refused"); - } else { - logevent("Agent forwarding enabled"); - ssh->agentfwd_enabled = TRUE; + if (qh->next) { + ssh->qhead = qh->next; + + if (ssh->qhead->msg1 > 0) { + ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1]; + ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler; + } + if (ssh->qhead->msg2 > 0) { + ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2]; + ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler; } + } else { + ssh->qhead = ssh->qtail = NULL; } - if (ssh->cfg.x11_forward) { - char proto[20], data[64]; - logevent("Requesting X11 forwarding"); - ssh->x11auth = x11_invent_auth(proto, sizeof(proto), - data, sizeof(data), ssh->cfg.x11_auth); - x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display); - if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { - send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, - PKT_STR, proto, PKT_STR, data, - PKT_INT, x11_get_screen_number(ssh->cfg.x11_display), - PKT_END); - } else { - send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, - PKT_STR, proto, PKT_STR, data, PKT_END); + qh->handler(ssh, pktin, qh->ctx); + + sfree(qh); +} + +static void ssh_queue_handler(Ssh ssh, int msg1, int msg2, + chandler_fn_t handler, void *ctx) +{ + struct queued_handler *qh; + + qh = snew(struct queued_handler); + qh->msg1 = msg1; + qh->msg2 = msg2; + qh->handler = handler; + qh->ctx = ctx; + qh->next = NULL; + + if (ssh->qtail == NULL) { + ssh->qhead = qh; + + if (qh->msg1 > 0) { + ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1]; + ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler; } - do { - crReturnV; - } while (!ispkt); - if (ssh->pktin.type != SSH1_SMSG_SUCCESS - && ssh->pktin.type != SSH1_SMSG_FAILURE) { - bombout(("Protocol confusion")); - crStopV; - } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { - logevent("X11 forwarding refused"); - } else { - logevent("X11 forwarding enabled"); - ssh->X11_fwd_enabled = TRUE; + if (qh->msg2 > 0) { + ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2]; + ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler; } + } else { + ssh->qtail->next = qh; } + ssh->qtail = qh; +} - { - char type; - int n; +static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx) +{ + struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx; + + if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS : + SSH2_MSG_REQUEST_SUCCESS)) { + logeventf(ssh, "Remote port forwarding from %s enabled", + pf->sportdesc); + } else { + logeventf(ssh, "Remote port forwarding from %s refused", + pf->sportdesc); + + rpf = del234(ssh->rportfwds, pf); + assert(rpf == pf); + pf->pfrec->remote = NULL; + free_rportfwd(pf); + } +} + +static void ssh_setup_portfwd(Ssh ssh, Conf *conf) +{ + struct ssh_portfwd *epf; + int i; + char *key, *val; + + if (!ssh->portfwds) { + ssh->portfwds = newtree234(ssh_portcmp); + } else { + /* + * Go through the existing port forwardings and tag them + * with status==DESTROY. Any that we want to keep will be + * re-enabled (status==KEEP) as we go through the + * configuration and find out which bits are the same as + * they were before. + */ + struct ssh_portfwd *epf; + int i; + for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) + epf->status = DESTROY; + } + + for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key); + val != NULL; + val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) { + char *kp, *kp2, *vp, *vp2; + char address_family, type; int sport,dport,sserv,dserv; - char sports[256], dports[256], saddr[256], host[256]; - - ssh->rportfwds = newtree234(ssh_rportcmp_ssh1); - /* Add port forwardings. */ - ssh->portfwd_strptr = ssh->cfg.portfwd; - while (*ssh->portfwd_strptr) { - type = *ssh->portfwd_strptr++; - saddr[0] = '\0'; - n = 0; - while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') { - if (*ssh->portfwd_strptr == ':') { - /* - * We've seen a colon in the middle of the - * source port number. This means that - * everything we've seen until now is the - * source _address_, so we'll move it into - * saddr and start sports from the beginning - * again. - */ - ssh->portfwd_strptr++; - sports[n] = '\0'; - strcpy(saddr, sports); - n = 0; - } - if (n < 255) sports[n++] = *ssh->portfwd_strptr++; + char *sports, *dports, *saddr, *host; + + kp = key; + + address_family = 'A'; + type = 'L'; + if (*kp == 'A' || *kp == '4' || *kp == '6') + address_family = *kp++; + if (*kp == 'L' || *kp == 'R') + type = *kp++; + + if ((kp2 = strchr(kp, ':')) != NULL) { + /* + * There's a colon in the middle of the source port + * string, which means that the part before it is + * actually a source address. + */ + saddr = dupprintf("%.*s", (int)(kp2 - kp), kp); + sports = kp2+1; + } else { + saddr = NULL; + sports = kp; + } + sport = atoi(sports); + sserv = 0; + if (sport == 0) { + sserv = 1; + sport = net_service_lookup(sports); + if (!sport) { + logeventf(ssh, "Service lookup failed for source" + " port \"%s\"", sports); } - sports[n] = 0; - if (type != 'D') { - if (*ssh->portfwd_strptr == '\t') - ssh->portfwd_strptr++; - n = 0; - while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') { - if (n < 255) host[n++] = *ssh->portfwd_strptr++; - } - host[n] = 0; - if (*ssh->portfwd_strptr == ':') - ssh->portfwd_strptr++; - n = 0; - while (*ssh->portfwd_strptr) { - if (n < 255) dports[n++] = *ssh->portfwd_strptr++; + } + + if (type == 'L' && !strcmp(val, "D")) { + /* dynamic forwarding */ + host = NULL; + dports = NULL; + dport = -1; + dserv = 0; + type = 'D'; + } else { + /* ordinary forwarding */ + vp = val; + vp2 = vp + strcspn(vp, ":"); + host = dupprintf("%.*s", (int)(vp2 - vp), vp); + if (vp2) + vp2++; + dports = vp2; + dport = atoi(dports); + dserv = 0; + if (dport == 0) { + dserv = 1; + dport = net_service_lookup(dports); + if (!dport) { + logeventf(ssh, "Service lookup failed for destination" + " port \"%s\"", dports); } - dports[n] = 0; - ssh->portfwd_strptr++; - dport = atoi(dports); - dserv = 0; - if (dport == 0) { - dserv = 1; - dport = net_service_lookup(dports); - if (!dport) { - logeventf(ssh, "Service lookup failed for" - " destination port \"%s\"", dports); - } + } + } + + if (sport && dport) { + /* Set up a description of the source port. */ + struct ssh_portfwd *pfrec, *epfrec; + + pfrec = snew(struct ssh_portfwd); + pfrec->type = type; + pfrec->saddr = saddr; + pfrec->sserv = sserv ? dupstr(sports) : NULL; + pfrec->sport = sport; + pfrec->daddr = host; + pfrec->dserv = dserv ? dupstr(dports) : NULL; + pfrec->dport = dport; + pfrec->local = NULL; + pfrec->remote = NULL; + pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 : + address_family == '6' ? ADDRTYPE_IPV6 : + ADDRTYPE_UNSPEC); + + epfrec = add234(ssh->portfwds, pfrec); + if (epfrec != pfrec) { + if (epfrec->status == DESTROY) { + /* + * We already have a port forwarding up and running + * with precisely these parameters. Hence, no need + * to do anything; simply re-tag the existing one + * as KEEP. + */ + epfrec->status = KEEP; } + /* + * Anything else indicates that there was a duplicate + * in our input, which we'll silently ignore. + */ + free_portfwd(pfrec); } else { - while (*ssh->portfwd_strptr) ssh->portfwd_strptr++; - dport = dserv = -1; + pfrec->status = CREATE; } - sport = atoi(sports); - sserv = 0; - if (sport == 0) { - sserv = 1; - sport = net_service_lookup(sports); - if (!sport) { - logeventf(ssh, "Service lookup failed for source" - " port \"%s\"", sports); - } + } else { + sfree(saddr); + sfree(host); + } + } + + /* + * Now go through and destroy any port forwardings which were + * not re-enabled. + */ + for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) + if (epf->status == DESTROY) { + char *message; + + message = dupprintf("%s port forwarding from %s%s%d", + epf->type == 'L' ? "local" : + epf->type == 'R' ? "remote" : "dynamic", + epf->saddr ? epf->saddr : "", + epf->saddr ? ":" : "", + epf->sport); + + if (epf->type != 'D') { + char *msg2 = dupprintf("%s to %s:%d", message, + epf->daddr, epf->dport); + sfree(message); + message = msg2; } - if (sport && dport) { - if (type == 'L') { - pfd_addforward(host, dport, *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s" - " forwarding to %s:%.*s%.*s%d%.*s", - (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL, - (int)(*saddr?1:0), ":", - (int)(sserv ? strlen(sports) : 0), sports, - sserv, "(", sport, sserv, ")", - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - } else if (type == 'D') { - pfd_addforward(NULL, -1, *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s" - " doing SOCKS dynamic forwarding", - (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL, - (int)(*saddr?1:0), ":", - (int)(sserv ? strlen(sports) : 0), sports, - sserv, "(", sport, sserv, ")"); + + logeventf(ssh, "Cancelling %s", message); + sfree(message); + + /* epf->remote or epf->local may be NULL if setting up a + * forwarding failed. */ + if (epf->remote) { + struct ssh_rportfwd *rpf = epf->remote; + struct Packet *pktout; + + /* + * Cancel the port forwarding at the server + * end. + */ + if (ssh->version == 1) { + /* + * We cannot cancel listening ports on the + * server side in SSH-1! There's no message + * to support it. Instead, we simply remove + * the rportfwd record from the local end + * so that any connections the server tries + * to make on it are rejected. + */ } else { - struct ssh_rportfwd *pf; - pf = snew(struct ssh_rportfwd); - strcpy(pf->dhost, host); - pf->dport = dport; - if (saddr) { - logeventf(ssh, - "SSH1 cannot handle source address spec \"%s:%d\"; ignoring", - saddr, sport); - } - if (add234(ssh->rportfwds, pf) != pf) { - logeventf(ssh, - "Duplicate remote port forwarding to %s:%d", - host, dport); - sfree(pf); + pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); + ssh2_pkt_addstring(pktout, "cancel-tcpip-forward"); + ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */ + if (epf->saddr) { + ssh2_pkt_addstring(pktout, epf->saddr); + } else if (conf_get_int(conf, CONF_rport_acceptall)) { + /* XXX: rport_acceptall may not represent + * what was used to open the original connection, + * since it's reconfigurable. */ + ssh2_pkt_addstring(pktout, ""); } else { - logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s" - " forward to %s:%.*s%.*s%d%.*s", - (int)(sserv ? strlen(sports) : 0), sports, - sserv, "(", sport, sserv, ")", - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST, - PKT_INT, sport, - PKT_STR, host, - PKT_INT, dport, - PKT_END); - do { - crReturnV; - } while (!ispkt); - if (ssh->pktin.type != SSH1_SMSG_SUCCESS - && ssh->pktin.type != SSH1_SMSG_FAILURE) { - bombout(("Protocol confusion")); - crStopV; - } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { - c_write_str(ssh, "Server refused port" - " forwarding\r\n"); - } - logevent("Remote port forwarding enabled"); + ssh2_pkt_addstring(pktout, "localhost"); } + ssh2_pkt_adduint32(pktout, epf->sport); + ssh2_pkt_send(ssh, pktout); } - } - } - } - if (!ssh->cfg.nopty) { - send_packet(ssh, SSH1_CMSG_REQUEST_PTY, - PKT_STR, ssh->cfg.termtype, - PKT_INT, ssh->term_height, - PKT_INT, ssh->term_width, - PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END); - ssh->state = SSH_STATE_INTERMED; - do { - crReturnV; - } while (!ispkt); - if (ssh->pktin.type != SSH1_SMSG_SUCCESS - && ssh->pktin.type != SSH1_SMSG_FAILURE) { - bombout(("Protocol confusion")); - crStopV; - } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { - c_write_str(ssh, "Server refused to allocate pty\r\n"); - ssh->editing = ssh->echoing = 1; - } - logevent("Allocated pty"); - } else { - ssh->editing = ssh->echoing = 1; - } + del234(ssh->rportfwds, rpf); + free_rportfwd(rpf); + } else if (epf->local) { + pfd_terminate(epf->local); + } - if (ssh->cfg.compression) { - send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); - do { - crReturnV; - } while (!ispkt); - if (ssh->pktin.type != SSH1_SMSG_SUCCESS - && ssh->pktin.type != SSH1_SMSG_FAILURE) { - bombout(("Protocol confusion")); - crStopV; - } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { - c_write_str(ssh, "Server refused to compress\r\n"); + delpos234(ssh->portfwds, i); + free_portfwd(epf); + i--; /* so we don't skip one in the list */ } - logevent("Started compression"); - ssh->v1_compressing = TRUE; - ssh->cs_comp_ctx = zlib_compress_init(); - logevent("Initialised zlib (RFC1950) compression"); - ssh->sc_comp_ctx = zlib_decompress_init(); - logevent("Initialised zlib (RFC1950) decompression"); - } /* - * Start the shell or command. - * - * Special case: if the first-choice command is an SSH2 - * subsystem (hence not usable here) and the second choice - * exists, we fall straight back to that. + * And finally, set up any new port forwardings (status==CREATE). */ - { - char *cmd = ssh->cfg.remote_cmd_ptr; - - if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) { - cmd = ssh->cfg.remote_cmd_ptr2; - ssh->fallback_cmd = TRUE; - } - if (*cmd) - send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); - else - send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END); - logevent("Started session"); - } + for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) + if (epf->status == CREATE) { + char *sportdesc, *dportdesc; + sportdesc = dupprintf("%s%s%s%s%d%s", + epf->saddr ? epf->saddr : "", + epf->saddr ? ":" : "", + epf->sserv ? epf->sserv : "", + epf->sserv ? "(" : "", + epf->sport, + epf->sserv ? ")" : ""); + if (epf->type == 'D') { + dportdesc = NULL; + } else { + dportdesc = dupprintf("%s:%s%s%d%s", + epf->daddr, + epf->dserv ? epf->dserv : "", + epf->dserv ? "(" : "", + epf->dport, + epf->dserv ? ")" : ""); + } - ssh->state = SSH_STATE_SESSION; - if (ssh->size_needed) - ssh_size(ssh, ssh->term_width, ssh->term_height); - if (ssh->eof_needed) - ssh_special(ssh, TS_EOF); + if (epf->type == 'L') { + const char *err = pfd_addforward(epf->daddr, epf->dport, + epf->saddr, epf->sport, + ssh, conf, + &epf->local, + epf->addressfamily); + + logeventf(ssh, "Local %sport %s forwarding to %s%s%s", + epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : + epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", + sportdesc, dportdesc, + err ? " failed: " : "", err ? err : ""); + } else if (epf->type == 'D') { + const char *err = pfd_addforward(NULL, -1, + epf->saddr, epf->sport, + ssh, conf, + &epf->local, + epf->addressfamily); + + logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s", + epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : + epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", + sportdesc, + err ? " failed: " : "", err ? err : ""); + } else { + struct ssh_rportfwd *pf; - if (ssh->ldisc) - ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ - ssh->send_ok = 1; - ssh->channels = newtree234(ssh_channelcmp); - while (1) { - crReturnV; - if (ispkt) { - if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA || - ssh->pktin.type == SSH1_SMSG_STDERR_DATA) { - long len = GET_32BIT(ssh->pktin.body); - int bufsize = - from_backend(ssh->frontend, - ssh->pktin.type == SSH1_SMSG_STDERR_DATA, - (char *)(ssh->pktin.body) + 4, len); - if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { - ssh->v1_stdout_throttling = 1; - ssh1_throttle(ssh, +1); - } - } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) { - ssh_closing((Plug)ssh, NULL, 0, 0); - logevent("Received disconnect request"); - crStopV; - } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) { - /* Remote side is trying to open a channel to talk to our - * X-Server. Give them back a local channel number. */ - struct ssh_channel *c; - - logevent("Received X11 connect request"); - /* Refuse if X11 forwarding is disabled. */ - if (!ssh->X11_fwd_enabled) { - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, - PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END); - logevent("Rejected X11 connect request"); - } else { - c = snew(struct ssh_channel); - c->ssh = ssh; - - if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c, - ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) { - logevent("opening X11 forward connection failed"); - sfree(c); - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, - PKT_INT, GET_32BIT(ssh->pktin.body), - PKT_END); - } else { - logevent - ("opening X11 forward connection succeeded"); - c->remoteid = GET_32BIT(ssh->pktin.body); - c->localid = alloc_channel_id(ssh); - c->closes = 0; - c->v.v1.throttling = 0; - c->type = CHAN_X11; /* identify channel type */ - add234(ssh->channels, c); - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, - PKT_INT, c->remoteid, PKT_INT, - c->localid, PKT_END); - logevent("Opened X11 forward channel"); - } - } - } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) { - /* Remote side is trying to open a channel to talk to our - * agent. Give them back a local channel number. */ - struct ssh_channel *c; - - /* Refuse if agent forwarding is disabled. */ - if (!ssh->agentfwd_enabled) { - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, - PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END); - } else { - c = snew(struct ssh_channel); - c->ssh = ssh; - c->remoteid = GET_32BIT(ssh->pktin.body); - c->localid = alloc_channel_id(ssh); - c->closes = 0; - c->v.v1.throttling = 0; - c->type = CHAN_AGENT; /* identify channel type */ - c->u.a.lensofar = 0; - add234(ssh->channels, c); - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, - PKT_INT, c->remoteid, PKT_INT, c->localid, - PKT_END); - } - } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) { - /* Remote side is trying to open a channel to talk to a - * forwarded port. Give them back a local channel number. */ - struct ssh_channel *c; - struct ssh_rportfwd pf; - int hostsize, port; - char host[256], buf[1024]; - char *p, *h; - const char *e; - c = snew(struct ssh_channel); - c->ssh = ssh; - - hostsize = GET_32BIT(ssh->pktin.body+4); - for (h = host, p = (char *)(ssh->pktin.body+8); - hostsize != 0; hostsize--) { - if (h+1 < host+sizeof(host)) - *h++ = *p; - p++; + /* + * Ensure the remote port forwardings tree exists. + */ + if (!ssh->rportfwds) { + if (ssh->version == 1) + ssh->rportfwds = newtree234(ssh_rportcmp_ssh1); + else + ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); } - *h = 0; - port = GET_32BIT(p); - - strcpy(pf.dhost, host); - pf.dport = port; - - if (find234(ssh->rportfwds, &pf, NULL) == NULL) { - sprintf(buf, "Rejected remote port open request for %s:%d", - host, port); - logevent(buf); - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, - PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END); + + pf = snew(struct ssh_rportfwd); + strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1); + pf->dhost[lenof(pf->dhost)-1] = '\0'; + pf->dport = epf->dport; + pf->sport = epf->sport; + if (add234(ssh->rportfwds, pf) != pf) { + logeventf(ssh, "Duplicate remote port forwarding to %s:%d", + epf->daddr, epf->dport); + sfree(pf); } else { - sprintf(buf, "Received remote port open request for %s:%d", - host, port); - logevent(buf); - e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg); - if (e != NULL) { - char buf[256]; - sprintf(buf, "Port open failed: %s", e); - logevent(buf); - sfree(c); - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, - PKT_INT, GET_32BIT(ssh->pktin.body), + logeventf(ssh, "Requesting remote port %s" + " forward to %s", sportdesc, dportdesc); + + pf->sportdesc = sportdesc; + sportdesc = NULL; + epf->remote = pf; + pf->pfrec = epf; + + if (ssh->version == 1) { + send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST, + PKT_INT, epf->sport, + PKT_STR, epf->daddr, + PKT_INT, epf->dport, PKT_END); + ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS, + SSH1_SMSG_FAILURE, + ssh_rportfwd_succfail, pf); } else { - c->remoteid = GET_32BIT(ssh->pktin.body); - c->localid = alloc_channel_id(ssh); - c->closes = 0; - c->v.v1.throttling = 0; - c->type = CHAN_SOCKDATA; /* identify channel type */ - add234(ssh->channels, c); - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, - PKT_INT, c->remoteid, PKT_INT, - c->localid, PKT_END); - logevent("Forwarded port opened successfully"); - } - } + struct Packet *pktout; + pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); + ssh2_pkt_addstring(pktout, "tcpip-forward"); + ssh2_pkt_addbool(pktout, 1);/* want reply */ + if (epf->saddr) { + ssh2_pkt_addstring(pktout, epf->saddr); + } else if (conf_get_int(conf, CONF_rport_acceptall)) { + ssh2_pkt_addstring(pktout, ""); + } else { + ssh2_pkt_addstring(pktout, "localhost"); + } + ssh2_pkt_adduint32(pktout, epf->sport); + ssh2_pkt_send(ssh, pktout); - } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) { - unsigned int remoteid = GET_32BIT(ssh->pktin.body); - unsigned int localid = GET_32BIT(ssh->pktin.body+4); - struct ssh_channel *c; - - c = find234(ssh->channels, &remoteid, ssh_channelfind); - if (c && c->type == CHAN_SOCKDATA_DORMANT) { - c->remoteid = localid; - c->type = CHAN_SOCKDATA; - c->v.v1.throttling = 0; - pfd_confirm(c->u.pfd.s); + ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, + SSH2_MSG_REQUEST_FAILURE, + ssh_rportfwd_succfail, pf); + } } + } + sfree(sportdesc); + sfree(dportdesc); + } +} - if (c && c->closes) { - /* - * We have a pending close on this channel, - * which we decided on before the server acked - * the channel open. So now we know the - * remoteid, we can close it again. - */ - send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, - PKT_INT, c->remoteid, PKT_END); - } +static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin) +{ + char *string; + int stringlen, bufsize; - } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) { - unsigned int remoteid = GET_32BIT(ssh->pktin.body); - struct ssh_channel *c; + ssh_pkt_getstring(pktin, &string, &stringlen); + if (string == NULL) { + bombout(("Incoming terminal data packet was badly formed")); + return; + } - c = find234(ssh->channels, &remoteid, ssh_channelfind); - if (c && c->type == CHAN_SOCKDATA_DORMANT) { - logevent("Forwarded connection refused by server"); - pfd_close(c->u.pfd.s); - del234(ssh->channels, c); - sfree(c); - } + bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA, + string, stringlen); + if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { + ssh->v1_stdout_throttling = 1; + ssh_throttle_conn(ssh, +1); + } +} - } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE || - ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { - /* Remote side closes a channel. */ - unsigned i = GET_32BIT(ssh->pktin.body); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (c && ((int)c->remoteid) != -1) { - int closetype; - closetype = - (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); - - if ((c->closes == 0) && (c->type == CHAN_X11)) { - logevent("Forwarded X11 connection terminated"); - assert(c->u.x11.s != NULL); - x11_close(c->u.x11.s); - c->u.x11.s = NULL; - } - if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) { - logevent("Forwarded port closed"); - assert(c->u.pfd.s != NULL); - pfd_close(c->u.pfd.s); - c->u.pfd.s = NULL; - } +static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin) +{ + /* Remote side is trying to open a channel to talk to our + * X-Server. Give them back a local channel number. */ + struct ssh_channel *c; + int remoteid = ssh_pkt_getuint32(pktin); + + logevent("Received X11 connect request"); + /* Refuse if X11 forwarding is disabled. */ + if (!ssh->X11_fwd_enabled) { + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, remoteid, PKT_END); + logevent("Rejected X11 connect request"); + } else { + c = snew(struct ssh_channel); + c->ssh = ssh; - c->closes |= (closetype << 2); /* seen this message */ - if (!(c->closes & closetype)) { - send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid, - PKT_END); - c->closes |= closetype; /* sent it too */ - } + if (x11_init(&c->u.x11.s, ssh->x11disp, c, + NULL, -1, ssh->conf) != NULL) { + logevent("Opening X11 forward connection failed"); + sfree(c); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, remoteid, PKT_END); + } else { + logevent + ("Opening X11 forward connection succeeded"); + c->remoteid = remoteid; + c->halfopen = FALSE; + c->localid = alloc_channel_id(ssh); + c->closes = 0; + c->pending_eof = FALSE; + c->throttling_conn = 0; + c->type = CHAN_X11; /* identify channel type */ + add234(ssh->channels, c); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, + PKT_INT, c->remoteid, PKT_INT, + c->localid, PKT_END); + logevent("Opened X11 forward channel"); + } + } +} - if (c->closes == 15) { - del234(ssh->channels, c); - sfree(c); - } - } else { - bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n", - ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" : - "_CONFIRMATION", c ? "half-open" : "nonexistent", - i)); - crStopV; +static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin) +{ + /* Remote side is trying to open a channel to talk to our + * agent. Give them back a local channel number. */ + struct ssh_channel *c; + int remoteid = ssh_pkt_getuint32(pktin); + + /* Refuse if agent forwarding is disabled. */ + if (!ssh->agentfwd_enabled) { + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, remoteid, PKT_END); + } else { + c = snew(struct ssh_channel); + c->ssh = ssh; + c->remoteid = remoteid; + c->halfopen = FALSE; + c->localid = alloc_channel_id(ssh); + c->closes = 0; + c->pending_eof = FALSE; + c->throttling_conn = 0; + c->type = CHAN_AGENT; /* identify channel type */ + c->u.a.lensofar = 0; + c->u.a.message = NULL; + c->u.a.outstanding_requests = 0; + add234(ssh->channels, c); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, + PKT_INT, c->remoteid, PKT_INT, c->localid, + PKT_END); + } +} + +static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin) +{ + /* Remote side is trying to open a channel to talk to a + * forwarded port. Give them back a local channel number. */ + struct ssh_rportfwd pf, *pfp; + int remoteid; + int hostsize, port; + char *host; + const char *e; + + remoteid = ssh_pkt_getuint32(pktin); + ssh_pkt_getstring(pktin, &host, &hostsize); + port = ssh_pkt_getuint32(pktin); + + if (hostsize >= lenof(pf.dhost)) + hostsize = lenof(pf.dhost)-1; + memcpy(pf.dhost, host, hostsize); + pf.dhost[hostsize] = '\0'; + pf.dport = port; + pfp = find234(ssh->rportfwds, &pf, NULL); + + if (pfp == NULL) { + logeventf(ssh, "Rejected remote port open request for %s:%d", + pf.dhost, port); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, remoteid, PKT_END); + } else { + struct ssh_channel *c = snew(struct ssh_channel); + c->ssh = ssh; + + logeventf(ssh, "Received remote port open request for %s:%d", + pf.dhost, port); + e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port, + c, ssh->conf, pfp->pfrec->addressfamily); + if (e != NULL) { + logeventf(ssh, "Port open failed: %s", e); + sfree(c); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, remoteid, PKT_END); + } else { + c->remoteid = remoteid; + c->halfopen = FALSE; + c->localid = alloc_channel_id(ssh); + c->closes = 0; + c->pending_eof = FALSE; + c->throttling_conn = 0; + c->type = CHAN_SOCKDATA; /* identify channel type */ + add234(ssh->channels, c); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, + PKT_INT, c->remoteid, PKT_INT, + c->localid, PKT_END); + logevent("Forwarded port opened successfully"); + } + } +} + +static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) +{ + unsigned int remoteid = ssh_pkt_getuint32(pktin); + unsigned int localid = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + + c = find234(ssh->channels, &remoteid, ssh_channelfind); + if (c && c->type == CHAN_SOCKDATA_DORMANT) { + c->remoteid = localid; + c->halfopen = FALSE; + c->type = CHAN_SOCKDATA; + c->throttling_conn = 0; + pfd_confirm(c->u.pfd.s); + } + + if (c && c->pending_eof) { + /* + * We have a pending close on this channel, + * which we decided on before the server acked + * the channel open. So now we know the + * remoteid, we can close it again. + */ + ssh_channel_try_eof(c); + } +} + +static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) +{ + unsigned int remoteid = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + + c = find234(ssh->channels, &remoteid, ssh_channelfind); + if (c && c->type == CHAN_SOCKDATA_DORMANT) { + logevent("Forwarded connection refused by server"); + pfd_close(c->u.pfd.s); + del234(ssh->channels, c); + sfree(c); + } +} + +static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin) +{ + /* Remote side closes a channel. */ + unsigned i = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + c = find234(ssh->channels, &i, ssh_channelfind); + if (c && !c->halfopen) { + + if (pktin->type == SSH1_MSG_CHANNEL_CLOSE && + !(c->closes & CLOSES_RCVD_EOF)) { + /* + * Received CHANNEL_CLOSE, which we translate into + * outgoing EOF. + */ + int send_close = FALSE; + + c->closes |= CLOSES_RCVD_EOF; + + switch (c->type) { + case CHAN_X11: + if (c->u.x11.s) + x11_send_eof(c->u.x11.s); + else + send_close = TRUE; + break; + case CHAN_SOCKDATA: + if (c->u.pfd.s) + pfd_send_eof(c->u.pfd.s); + else + send_close = TRUE; + break; + case CHAN_AGENT: + send_close = TRUE; + break; + } + + if (send_close && !(c->closes & CLOSES_SENT_EOF)) { + send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, + PKT_END); + c->closes |= CLOSES_SENT_EOF; + } + } + + if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION && + !(c->closes & CLOSES_RCVD_CLOSE)) { + + if (!(c->closes & CLOSES_SENT_EOF)) { + bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d" + " for which we never sent CHANNEL_CLOSE\n", i)); + } + + c->closes |= CLOSES_RCVD_CLOSE; + } + + if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) && + !(c->closes & CLOSES_SENT_CLOSE)) { + send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION, + PKT_INT, c->remoteid, PKT_END); + c->closes |= CLOSES_SENT_CLOSE; + } + + if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) + ssh_channel_destroy(c); + } else { + bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n", + pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" : + "_CONFIRMATION", c ? "half-open" : "nonexistent", + i)); + } +} + +static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin) +{ + /* Data sent down one of our channels. */ + int i = ssh_pkt_getuint32(pktin); + char *p; + int len; + struct ssh_channel *c; + + ssh_pkt_getstring(pktin, &p, &len); + + c = find234(ssh->channels, &i, ssh_channelfind); + if (c) { + int bufsize = 0; + switch (c->type) { + case CHAN_X11: + bufsize = x11_send(c->u.x11.s, p, len); + break; + case CHAN_SOCKDATA: + bufsize = pfd_send(c->u.pfd.s, p, len); + break; + case CHAN_AGENT: + /* Data for an agent message. Buffer it. */ + while (len > 0) { + if (c->u.a.lensofar < 4) { + unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len); + memcpy(c->u.a.msglen + c->u.a.lensofar, p, + l); + p += l; + len -= l; + c->u.a.lensofar += l; } - } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) { - /* Data sent down one of our channels. */ - int i = GET_32BIT(ssh->pktin.body); - int len = GET_32BIT(ssh->pktin.body + 4); - unsigned char *p = ssh->pktin.body + 8; - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (c) { - int bufsize = 0; - switch (c->type) { - case CHAN_X11: - bufsize = x11_send(c->u.x11.s, (char *)p, len); - break; - case CHAN_SOCKDATA: - bufsize = pfd_send(c->u.pfd.s, (char *)p, len); - break; - case CHAN_AGENT: - /* Data for an agent message. Buffer it. */ - while (len > 0) { - if (c->u.a.lensofar < 4) { - int l = min(4 - c->u.a.lensofar, len); - memcpy(c->u.a.msglen + c->u.a.lensofar, p, - l); - p += l; - len -= l; - c->u.a.lensofar += l; - } - if (c->u.a.lensofar == 4) { - c->u.a.totallen = - 4 + GET_32BIT(c->u.a.msglen); - c->u.a.message = snewn(c->u.a.totallen, - unsigned char); - memcpy(c->u.a.message, c->u.a.msglen, 4); - } - if (c->u.a.lensofar >= 4 && len > 0) { - int l = - min(c->u.a.totallen - c->u.a.lensofar, - len); - memcpy(c->u.a.message + c->u.a.lensofar, p, - l); - p += l; - len -= l; - c->u.a.lensofar += l; - } - if (c->u.a.lensofar == c->u.a.totallen) { - void *reply; - int replylen; - if (agent_query(c->u.a.message, - c->u.a.totallen, - &reply, &replylen, - ssh_agentf_callback, c)) - ssh_agentf_callback(c, reply, replylen); - sfree(c->u.a.message); - c->u.a.lensofar = 0; - } - } - bufsize = 0; /* agent channels never back up */ - break; - } - if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) { - c->v.v1.throttling = 1; - ssh1_throttle(ssh, +1); - } + if (c->u.a.lensofar == 4) { + c->u.a.totallen = + 4 + GET_32BIT(c->u.a.msglen); + c->u.a.message = snewn(c->u.a.totallen, + unsigned char); + memcpy(c->u.a.message, c->u.a.msglen, 4); + } + if (c->u.a.lensofar >= 4 && len > 0) { + unsigned int l = + min(c->u.a.totallen - c->u.a.lensofar, + (unsigned)len); + memcpy(c->u.a.message + c->u.a.lensofar, p, + l); + p += l; + len -= l; + c->u.a.lensofar += l; + } + if (c->u.a.lensofar == c->u.a.totallen) { + void *reply; + int replylen; + c->u.a.outstanding_requests++; + if (agent_query(c->u.a.message, + c->u.a.totallen, + &reply, &replylen, + ssh_agentf_callback, c)) + ssh_agentf_callback(c, reply, replylen); + sfree(c->u.a.message); + c->u.a.lensofar = 0; } - } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) { + } + bufsize = 0; /* agent channels never back up */ + break; + } + if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) { + c->throttling_conn = 1; + ssh_throttle_conn(ssh, +1); + } + } +} + +static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin) +{ + ssh->exitcode = ssh_pkt_getuint32(pktin); + logeventf(ssh, "Server sent command exit status %d", ssh->exitcode); + send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); + /* + * In case `helpful' firewalls or proxies tack + * extra human-readable text on the end of the + * session which we might mistake for another + * encrypted packet, we close the session once + * we've sent EXIT_CONFIRMATION. + */ + ssh_disconnect(ssh, NULL, NULL, 0, TRUE); +} + +/* Helper function to deal with sending tty modes for REQUEST_PTY */ +static void ssh1_send_ttymode(void *data, char *mode, char *val) +{ + struct Packet *pktout = (struct Packet *)data; + int i = 0; + unsigned int arg = 0; + while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; + if (i == lenof(ssh_ttymodes)) return; + switch (ssh_ttymodes[i].type) { + case TTY_OP_CHAR: + arg = ssh_tty_parse_specchar(val); + break; + case TTY_OP_BOOL: + arg = ssh_tty_parse_boolean(val); + break; + } + ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); + ssh2_pkt_addbyte(pktout, arg); +} + + +static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin) +{ + crBegin(ssh->do_ssh1_connection_crstate); + + ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] = + ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] = + ssh1_smsg_stdout_stderr_data; + + ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] = + ssh1_msg_channel_open_confirmation; + ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] = + ssh1_msg_channel_open_failure; + ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] = + ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] = + ssh1_msg_channel_close; + ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data; + ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status; + + if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) { + logevent("Requesting agent forwarding"); + send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); + do { + crReturnV; + } while (!pktin); + if (pktin->type != SSH1_SMSG_SUCCESS + && pktin->type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crStopV; + } else if (pktin->type == SSH1_SMSG_FAILURE) { + logevent("Agent forwarding refused"); + } else { + logevent("Agent forwarding enabled"); + ssh->agentfwd_enabled = TRUE; + ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open; + } + } + + if (conf_get_int(ssh->conf, CONF_x11_forward) && + (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), + conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) { + logevent("Requesting X11 forwarding"); + /* + * Note that while we blank the X authentication data here, we don't + * take any special action to blank the start of an X11 channel, + * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection + * without having session blanking enabled is likely to leak your + * cookie into the log. + */ + if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { + send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, + PKT_STR, ssh->x11disp->remoteauthprotoname, + PKTT_PASSWORD, + PKT_STR, ssh->x11disp->remoteauthdatastring, + PKTT_OTHER, + PKT_INT, ssh->x11disp->screennum, + PKT_END); + } else { + send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, + PKT_STR, ssh->x11disp->remoteauthprotoname, + PKTT_PASSWORD, + PKT_STR, ssh->x11disp->remoteauthdatastring, + PKTT_OTHER, + PKT_END); + } + do { + crReturnV; + } while (!pktin); + if (pktin->type != SSH1_SMSG_SUCCESS + && pktin->type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crStopV; + } else if (pktin->type == SSH1_SMSG_FAILURE) { + logevent("X11 forwarding refused"); + } else { + logevent("X11 forwarding enabled"); + ssh->X11_fwd_enabled = TRUE; + ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open; + } + } + + ssh_setup_portfwd(ssh, ssh->conf); + ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open; + + if (!conf_get_int(ssh->conf, CONF_nopty)) { + struct Packet *pkt; + /* Unpick the terminal-speed string. */ + /* XXX perhaps we should allow no speeds to be sent. */ + ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ + sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed); + /* Send the pty request. */ + pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY); + ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype)); + ssh_pkt_adduint32(pkt, ssh->term_height); + ssh_pkt_adduint32(pkt, ssh->term_width); + ssh_pkt_adduint32(pkt, 0); /* width in pixels */ + ssh_pkt_adduint32(pkt, 0); /* height in pixels */ + parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt); + ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED); + ssh_pkt_adduint32(pkt, ssh->ispeed); + ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED); + ssh_pkt_adduint32(pkt, ssh->ospeed); + ssh_pkt_addbyte(pkt, SSH_TTY_OP_END); + s_wrpkt(ssh, pkt); + ssh->state = SSH_STATE_INTERMED; + do { + crReturnV; + } while (!pktin); + if (pktin->type != SSH1_SMSG_SUCCESS + && pktin->type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crStopV; + } else if (pktin->type == SSH1_SMSG_FAILURE) { + c_write_str(ssh, "Server refused to allocate pty\r\n"); + ssh->editing = ssh->echoing = 1; + } else { + logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", + ssh->ospeed, ssh->ispeed); + ssh->got_pty = TRUE; + } + } else { + ssh->editing = ssh->echoing = 1; + } + + if (conf_get_int(ssh->conf, CONF_compression)) { + send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); + do { + crReturnV; + } while (!pktin); + if (pktin->type != SSH1_SMSG_SUCCESS + && pktin->type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crStopV; + } else if (pktin->type == SSH1_SMSG_FAILURE) { + c_write_str(ssh, "Server refused to compress\r\n"); + } + logevent("Started compression"); + ssh->v1_compressing = TRUE; + ssh->cs_comp_ctx = zlib_compress_init(); + logevent("Initialised zlib (RFC1950) compression"); + ssh->sc_comp_ctx = zlib_decompress_init(); + logevent("Initialised zlib (RFC1950) decompression"); + } + + /* + * Start the shell or command. + * + * Special case: if the first-choice command is an SSH-2 + * subsystem (hence not usable here) and the second choice + * exists, we fall straight back to that. + */ + { + char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd); + + if (conf_get_int(ssh->conf, CONF_ssh_subsys) && + conf_get_str(ssh->conf, CONF_remote_cmd2)) { + cmd = conf_get_str(ssh->conf, CONF_remote_cmd2); + ssh->fallback_cmd = TRUE; + } + if (*cmd) + send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); + else + send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END); + logevent("Started session"); + } + + ssh->state = SSH_STATE_SESSION; + if (ssh->size_needed) + ssh_size(ssh, ssh->term_width, ssh->term_height); + if (ssh->eof_needed) + ssh_special(ssh, TS_EOF); + + if (ssh->ldisc) + ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ + ssh->send_ok = 1; + ssh->channels = newtree234(ssh_channelcmp); + while (1) { + + /* + * By this point, most incoming packets are already being + * handled by the dispatch table, and we need only pay + * attention to the unusual ones. + */ + + crReturnV; + if (pktin) { + if (pktin->type == SSH1_SMSG_SUCCESS) { /* may be from EXEC_SHELL on some servers */ - } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { + } else if (pktin->type == SSH1_SMSG_FAILURE) { /* may be from EXEC_SHELL on some servers * if no pty is available or in other odd cases. Ignore */ - } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) { - char buf[100]; - ssh->exitcode = GET_32BIT(ssh->pktin.body); - sprintf(buf, "Server sent command exit status %d", - ssh->exitcode); - logevent(buf); - send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); - /* - * In case `helpful' firewalls or proxies tack - * extra human-readable text on the end of the - * session which we might mistake for another - * encrypted packet, we close the session once - * we've sent EXIT_CONFIRMATION. - */ - ssh_closing((Plug)ssh, NULL, 0, 0); - crStopV; } else { - bombout(("Strange packet received: type %d", ssh->pktin.type)); + bombout(("Strange packet received: type %d", pktin->type)); crStopV; } } else { while (inlen > 0) { int len = min(inlen, 512); send_packet(ssh, SSH1_CMSG_STDIN_DATA, - PKT_INT, len, PKT_DATA, in, len, PKT_END); + PKT_INT, len, PKTT_DATA, PKT_DATA, in, len, + PKTT_OTHER, PKT_END); in += len; inlen -= len; } @@ -3773,6 +5350,73 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt) } /* + * Handle the top-level SSH-2 protocol. + */ +static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin) +{ + char *msg; + int msglen; + + ssh_pkt_getstring(pktin, &msg, &msglen); + logeventf(ssh, "Remote debug message: %.*s", msglen, msg); +} + +static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) +{ + /* log reason code in disconnect message */ + char *msg; + int msglen; + + ssh_pkt_getstring(pktin, &msg, &msglen); + bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg)); +} + +static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin) +{ + /* Do nothing, because we're ignoring it! Duhh. */ +} + +static void ssh1_protocol_setup(Ssh ssh) +{ + int i; + + /* + * Most messages are handled by the coroutines. + */ + for (i = 0; i < 256; i++) + ssh->packet_dispatch[i] = NULL; + + /* + * These special message types we install handlers for. + */ + ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect; + ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore; + ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug; +} + +static void ssh1_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin) +{ + unsigned char *in=(unsigned char*)vin; + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (pktin && ssh->packet_dispatch[pktin->type]) { + ssh->packet_dispatch[pktin->type](ssh, pktin); + return; + } + + if (!ssh->protocol_initial_phase_done) { + if (do_ssh1_login(ssh, in, inlen, pktin)) + ssh->protocol_initial_phase_done = TRUE; + else + return; + } + + do_ssh1_connection(ssh, in, inlen, pktin); +} + +/* * Utility routine for decoding comma-separated strings in KEXINIT. */ static int in_commasep_string(char *needle, char *haystack, int haylen) @@ -3804,38 +5448,68 @@ static int in_commasep_string(char *needle, char *haystack, int haylen) } /* - * SSH2 key creation method. + * Similar routine for checking whether we have the first string in a list. */ -static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, - unsigned char *sessid, char chr, - unsigned char *keyspace) +static int first_in_commasep_string(char *needle, char *haystack, int haylen) { - SHA_State s; - /* First 20 bytes. */ - SHA_Init(&s); - if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) - sha_mpint(&s, K); - SHA_Bytes(&s, H, 20); - SHA_Bytes(&s, &chr, 1); - SHA_Bytes(&s, sessid, 20); - SHA_Final(&s, keyspace); - /* Next 20 bytes. */ - SHA_Init(&s); - if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) - sha_mpint(&s, K); - SHA_Bytes(&s, H, 20); - SHA_Bytes(&s, keyspace, 20); - SHA_Final(&s, keyspace + 20); + int needlen; + if (!needle || !haystack) /* protect against null pointers */ + return 0; + needlen = strlen(needle); + /* + * Is it at the start of the string? + */ + if (haylen >= needlen && /* haystack is long enough */ + !memcmp(needle, haystack, needlen) && /* initial match */ + (haylen == needlen || haystack[needlen] == ',') + /* either , or EOS follows */ + ) + return 1; + return 0; +} + + +/* + * SSH-2 key creation method. + * (Currently assumes 2 lots of any hash are sufficient to generate + * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.) + */ +#define SSH2_MKKEY_ITERS (2) +static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr, + unsigned char *keyspace) +{ + const struct ssh_hash *h = ssh->kex->hash; + void *s; + /* First hlen bytes. */ + s = h->init(); + if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) + hash_mpint(h, s, K); + h->bytes(s, H, h->hlen); + h->bytes(s, &chr, 1); + h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len); + h->final(s, keyspace); + /* Next hlen bytes. */ + s = h->init(); + if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) + hash_mpint(h, s, K); + h->bytes(s, H, h->hlen); + h->bytes(s, keyspace, h->hlen); + h->final(s, keyspace + h->hlen); } /* - * Handle the SSH2 transport layer. + * Handle the SSH-2 transport layer. */ -static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt) +static void do_ssh2_transport(Ssh ssh, void *vin, int inlen, + struct Packet *pktin) { + unsigned char *in = (unsigned char *)vin; struct do_ssh2_transport_state { - int nbits, pbits, warn; + int crLine; + int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher; Bignum p, g, e, f, K; + void *our_kexinit; + int our_kexinitlen; int kex_init_value, kex_reply_value; const struct ssh_mac **maclist; int nmacs; @@ -3845,39 +5519,92 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt) const struct ssh_mac *scmac_tobe; const struct ssh_compress *cscomp_tobe; const struct ssh_compress *sccomp_tobe; - char *hostkeydata, *sigdata, *keystr, *fingerprint; - int hostkeylen, siglen; + char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint; + int hostkeylen, siglen, rsakeylen; void *hkey; /* actual host key */ - unsigned char exchange_hash[20]; + void *rsakey; /* for RSA kex */ + unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN]; + int n_preferred_kex; + const struct ssh_kexes *preferred_kex[KEX_MAX]; int n_preferred_ciphers; const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; const struct ssh_compress *preferred_comp; - int first_kex; + int userauth_succeeded; /* for delayed compression */ + int pending_compression; + int got_session_id, activated_authconn; + struct Packet *pktout; + int dlgret; + int guessok; + int ignorepkt; }; crState(do_ssh2_transport_state); - crBegin(ssh->do_ssh2_transport_crstate); + crBeginState; s->cscipher_tobe = s->sccipher_tobe = NULL; s->csmac_tobe = s->scmac_tobe = NULL; s->cscomp_tobe = s->sccomp_tobe = NULL; - random_init(); - s->first_kex = 1; + s->got_session_id = s->activated_authconn = FALSE; + s->userauth_succeeded = FALSE; + s->pending_compression = FALSE; + + /* + * Be prepared to work around the buggy MAC problem. + */ + if (ssh->remote_bugs & BUG_SSH2_HMAC) + s->maclist = buggymacs, s->nmacs = lenof(buggymacs); + else + s->maclist = macs, s->nmacs = lenof(macs); + begin_key_exchange: + ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; { - int i; + int i, j, k, commalist_started; + + /* + * Set up the preferred key exchange. (NULL => warn below here) + */ + s->n_preferred_kex = 0; + for (i = 0; i < KEX_MAX; i++) { + switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) { + case KEX_DHGEX: + s->preferred_kex[s->n_preferred_kex++] = + &ssh_diffiehellman_gex; + break; + case KEX_DHGROUP14: + s->preferred_kex[s->n_preferred_kex++] = + &ssh_diffiehellman_group14; + break; + case KEX_DHGROUP1: + s->preferred_kex[s->n_preferred_kex++] = + &ssh_diffiehellman_group1; + break; + case KEX_RSA: + s->preferred_kex[s->n_preferred_kex++] = + &ssh_rsa_kex; + break; + case KEX_WARN: + /* Flag for later. Don't bother if it's the last in + * the list. */ + if (i < KEX_MAX - 1) { + s->preferred_kex[s->n_preferred_kex++] = NULL; + } + break; + } + } + /* * Set up the preferred ciphers. (NULL => warn below here) */ s->n_preferred_ciphers = 0; for (i = 0; i < CIPHER_MAX; i++) { - switch (ssh->cfg.ssh_cipherlist[i]) { + switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) { case CIPHER_BLOWFISH: s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish; break; case CIPHER_DES: - if (ssh->cfg.ssh2_des_cbc) { + if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) { s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des; } break; @@ -3887,6 +5614,9 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt) case CIPHER_AES: s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes; break; + case CIPHER_ARCFOUR: + s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour; + break; case CIPHER_WARN: /* Flag for later. Don't bother if it's the last in * the list. */ @@ -3896,140 +5626,134 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt) break; } } - } - /* - * Set up preferred compression. - */ - if (ssh->cfg.compression) - s->preferred_comp = &ssh_zlib; - else - s->preferred_comp = &ssh_comp_none; + /* + * Set up preferred compression. + */ + if (conf_get_int(ssh->conf, CONF_compression)) + s->preferred_comp = &ssh_zlib; + else + s->preferred_comp = &ssh_comp_none; - /* - * Be prepared to work around the buggy MAC problem. - */ - if (ssh->remote_bugs & BUG_SSH2_HMAC) - s->maclist = buggymacs, s->nmacs = lenof(buggymacs); - else - s->maclist = macs, s->nmacs = lenof(macs); + /* + * Enable queueing of outgoing auth- or connection-layer + * packets while we are in the middle of a key exchange. + */ + ssh->queueing = TRUE; - begin_key_exchange: - { - int i, j, cipherstr_started; + /* + * Flag that KEX is in progress. + */ + ssh->kex_in_progress = TRUE; /* * Construct and send our key exchange packet. */ - ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT); + s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT); for (i = 0; i < 16; i++) - ssh2_pkt_addbyte(ssh, (unsigned char) random_byte()); + ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte()); /* List key exchange algorithms. */ - ssh2_pkt_addstring_start(ssh); - for (i = 0; i < lenof(kex_algs); i++) { - if (kex_algs[i] == &ssh_diffiehellman_gex && - (ssh->remote_bugs & BUG_SSH2_DH_GEX)) - continue; - ssh2_pkt_addstring_str(ssh, kex_algs[i]->name); - if (i < lenof(kex_algs) - 1) - ssh2_pkt_addstring_str(ssh, ","); + ssh2_pkt_addstring_start(s->pktout); + commalist_started = 0; + for (i = 0; i < s->n_preferred_kex; i++) { + const struct ssh_kexes *k = s->preferred_kex[i]; + if (!k) continue; /* warning flag */ + for (j = 0; j < k->nkexes; j++) { + if (commalist_started) + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, k->list[j]->name); + commalist_started = 1; + } } /* List server host key algorithms. */ - ssh2_pkt_addstring_start(ssh); + ssh2_pkt_addstring_start(s->pktout); for (i = 0; i < lenof(hostkey_algs); i++) { - ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name); + ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name); if (i < lenof(hostkey_algs) - 1) - ssh2_pkt_addstring_str(ssh, ","); + ssh2_pkt_addstring_str(s->pktout, ","); } - /* List client->server encryption algorithms. */ - ssh2_pkt_addstring_start(ssh); - cipherstr_started = 0; - for (i = 0; i < s->n_preferred_ciphers; i++) { - const struct ssh2_ciphers *c = s->preferred_ciphers[i]; - if (!c) continue; /* warning flag */ - for (j = 0; j < c->nciphers; j++) { - if (cipherstr_started) - ssh2_pkt_addstring_str(ssh, ","); - ssh2_pkt_addstring_str(ssh, c->list[j]->name); - cipherstr_started = 1; + /* List encryption algorithms (client->server then server->client). */ + for (k = 0; k < 2; k++) { + ssh2_pkt_addstring_start(s->pktout); + commalist_started = 0; + for (i = 0; i < s->n_preferred_ciphers; i++) { + const struct ssh2_ciphers *c = s->preferred_ciphers[i]; + if (!c) continue; /* warning flag */ + for (j = 0; j < c->nciphers; j++) { + if (commalist_started) + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, c->list[j]->name); + commalist_started = 1; + } } } - /* List server->client encryption algorithms. */ - ssh2_pkt_addstring_start(ssh); - cipherstr_started = 0; - for (i = 0; i < s->n_preferred_ciphers; i++) { - const struct ssh2_ciphers *c = s->preferred_ciphers[i]; - if (!c) continue; /* warning flag */ - for (j = 0; j < c->nciphers; j++) { - if (cipherstr_started) - ssh2_pkt_addstring_str(ssh, ","); - ssh2_pkt_addstring_str(ssh, c->list[j]->name); - cipherstr_started = 1; + /* List MAC algorithms (client->server then server->client). */ + for (j = 0; j < 2; j++) { + ssh2_pkt_addstring_start(s->pktout); + for (i = 0; i < s->nmacs; i++) { + ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name); + if (i < s->nmacs - 1) + ssh2_pkt_addstring_str(s->pktout, ","); } } - /* List client->server MAC algorithms. */ - ssh2_pkt_addstring_start(ssh); - for (i = 0; i < s->nmacs; i++) { - ssh2_pkt_addstring_str(ssh, s->maclist[i]->name); - if (i < s->nmacs - 1) - ssh2_pkt_addstring_str(ssh, ","); - } - /* List server->client MAC algorithms. */ - ssh2_pkt_addstring_start(ssh); - for (i = 0; i < s->nmacs; i++) { - ssh2_pkt_addstring_str(ssh, s->maclist[i]->name); - if (i < s->nmacs - 1) - ssh2_pkt_addstring_str(ssh, ","); - } - /* List client->server compression algorithms. */ - ssh2_pkt_addstring_start(ssh); - for (i = 0; i < lenof(compressions) + 1; i++) { - const struct ssh_compress *c = - i == 0 ? s->preferred_comp : compressions[i - 1]; - ssh2_pkt_addstring_str(ssh, c->name); - if (i < lenof(compressions)) - ssh2_pkt_addstring_str(ssh, ","); - } - /* List server->client compression algorithms. */ - ssh2_pkt_addstring_start(ssh); - for (i = 0; i < lenof(compressions) + 1; i++) { - const struct ssh_compress *c = - i == 0 ? s->preferred_comp : compressions[i - 1]; - ssh2_pkt_addstring_str(ssh, c->name); - if (i < lenof(compressions)) - ssh2_pkt_addstring_str(ssh, ","); + /* List client->server compression algorithms, + * then server->client compression algorithms. (We use the + * same set twice.) */ + for (j = 0; j < 2; j++) { + ssh2_pkt_addstring_start(s->pktout); + assert(lenof(compressions) > 1); + /* Prefer non-delayed versions */ + ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name); + /* We don't even list delayed versions of algorithms until + * they're allowed to be used, to avoid a race. See the end of + * this function. */ + if (s->userauth_succeeded && s->preferred_comp->delayed_name) { + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, + s->preferred_comp->delayed_name); + } + for (i = 0; i < lenof(compressions); i++) { + const struct ssh_compress *c = compressions[i]; + if (c != s->preferred_comp) { + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, c->name); + if (s->userauth_succeeded && c->delayed_name) { + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, c->delayed_name); + } + } + } } /* List client->server languages. Empty list. */ - ssh2_pkt_addstring_start(ssh); + ssh2_pkt_addstring_start(s->pktout); /* List server->client languages. Empty list. */ - ssh2_pkt_addstring_start(ssh); + ssh2_pkt_addstring_start(s->pktout); /* First KEX packet does _not_ follow, because we're not that brave. */ - ssh2_pkt_addbool(ssh, FALSE); + ssh2_pkt_addbool(s->pktout, FALSE); /* Reserved. */ - ssh2_pkt_adduint32(ssh, 0); + ssh2_pkt_adduint32(s->pktout, 0); } - ssh->exhash = ssh->exhashbase; - sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5); + s->our_kexinitlen = s->pktout->length - 5; + s->our_kexinit = snewn(s->our_kexinitlen, unsigned char); + memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen); - ssh2_pkt_send(ssh); + ssh2_pkt_send_noqueue(ssh, s->pktout); - if (!ispkt) - crWaitUntil(ispkt); - if (ssh->pktin.length > 5) - sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5); + if (!pktin) + crWaitUntilV(pktin); /* * Now examine the other side's KEXINIT to see what we're up * to. */ { - char *str; + char *str, *preferred; int i, j, len; - if (ssh->pktin.type != SSH2_MSG_KEXINIT) { + if (pktin->type != SSH2_MSG_KEXINIT) { bombout(("expected key exchange packet from server")); - crStop(0); + crStopV; } ssh->kex = NULL; ssh->hostkey = NULL; @@ -4039,30 +5763,59 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt) s->scmac_tobe = NULL; s->cscomp_tobe = NULL; s->sccomp_tobe = NULL; - ssh->pktin.savedpos += 16; /* skip garbage cookie */ - ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */ - for (i = 0; i < lenof(kex_algs); i++) { - if (kex_algs[i] == &ssh_diffiehellman_gex && - (ssh->remote_bugs & BUG_SSH2_DH_GEX)) - continue; - if (in_commasep_string(kex_algs[i]->name, str, len)) { - ssh->kex = kex_algs[i]; - break; + s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE; + + pktin->savedpos += 16; /* skip garbage cookie */ + ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */ + + preferred = NULL; + for (i = 0; i < s->n_preferred_kex; i++) { + const struct ssh_kexes *k = s->preferred_kex[i]; + if (!k) { + s->warn_kex = TRUE; + } else { + for (j = 0; j < k->nkexes; j++) { + if (!preferred) preferred = k->list[j]->name; + if (in_commasep_string(k->list[j]->name, str, len)) { + ssh->kex = k->list[j]; + break; + } + } } + if (ssh->kex) + break; + } + if (!ssh->kex) { + bombout(("Couldn't agree a key exchange algorithm (available: %s)", + str ? str : "(null)")); + crStopV; } - ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */ + /* + * Note that the server's guess is considered wrong if it doesn't match + * the first algorithm in our list, even if it's still the algorithm + * we end up using. + */ + s->guessok = first_in_commasep_string(preferred, str, len); + ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */ for (i = 0; i < lenof(hostkey_algs); i++) { if (in_commasep_string(hostkey_algs[i]->name, str, len)) { ssh->hostkey = hostkey_algs[i]; break; } } - ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */ - s->warn = 0; + if (!ssh->hostkey) { + bombout(("Couldn't agree a host key algorithm (available: %s)", + str ? str : "(null)")); + crStopV; + } + + s->guessok = s->guessok && + first_in_commasep_string(hostkey_algs[0]->name, str, len); + ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */ for (i = 0; i < s->n_preferred_ciphers; i++) { const struct ssh2_ciphers *c = s->preferred_ciphers[i]; if (!c) { - s->warn = 1; + s->warn_cscipher = TRUE; } else { for (j = 0; j < c->nciphers; j++) { if (in_commasep_string(c->list[j]->name, str, len)) { @@ -4071,24 +5824,20 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt) } } } - if (s->cscipher_tobe) { - if (s->warn) - askcipher(ssh->frontend, s->cscipher_tobe->name, 1); + if (s->cscipher_tobe) break; - } } if (!s->cscipher_tobe) { bombout(("Couldn't agree a client-to-server cipher (available: %s)", str ? str : "(null)")); - crStop(0); + crStopV; } - ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */ - s->warn = 0; + ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */ for (i = 0; i < s->n_preferred_ciphers; i++) { const struct ssh2_ciphers *c = s->preferred_ciphers[i]; if (!c) { - s->warn = 1; + s->warn_sccipher = TRUE; } else { for (j = 0; j < c->nciphers; j++) { if (in_commasep_string(c->list[j]->name, str, len)) { @@ -4097,394 +5846,2166 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt) } } } - if (s->sccipher_tobe) { - if (s->warn) - askcipher(ssh->frontend, s->sccipher_tobe->name, 2); + if (s->sccipher_tobe) break; - } } if (!s->sccipher_tobe) { bombout(("Couldn't agree a server-to-client cipher (available: %s)", str ? str : "(null)")); - crStop(0); + crStopV; } - ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */ + ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */ for (i = 0; i < s->nmacs; i++) { if (in_commasep_string(s->maclist[i]->name, str, len)) { s->csmac_tobe = s->maclist[i]; break; } } - ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */ + ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */ for (i = 0; i < s->nmacs; i++) { if (in_commasep_string(s->maclist[i]->name, str, len)) { s->scmac_tobe = s->maclist[i]; break; } } - ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */ + ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */ for (i = 0; i < lenof(compressions) + 1; i++) { const struct ssh_compress *c = i == 0 ? s->preferred_comp : compressions[i - 1]; if (in_commasep_string(c->name, str, len)) { s->cscomp_tobe = c; break; + } else if (in_commasep_string(c->delayed_name, str, len)) { + if (s->userauth_succeeded) { + s->cscomp_tobe = c; + break; + } else { + s->pending_compression = TRUE; /* try this later */ + } } } - ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */ + ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */ for (i = 0; i < lenof(compressions) + 1; i++) { const struct ssh_compress *c = i == 0 ? s->preferred_comp : compressions[i - 1]; if (in_commasep_string(c->name, str, len)) { s->sccomp_tobe = c; break; + } else if (in_commasep_string(c->delayed_name, str, len)) { + if (s->userauth_succeeded) { + s->sccomp_tobe = c; + break; + } else { + s->pending_compression = TRUE; /* try this later */ + } + } + } + if (s->pending_compression) { + logevent("Server supports delayed compression; " + "will try this later"); + } + ssh_pkt_getstring(pktin, &str, &len); /* client->server language */ + ssh_pkt_getstring(pktin, &str, &len); /* server->client language */ + s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok; + + ssh->exhash = ssh->kex->hash->init(); + hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c)); + hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s)); + hash_string(ssh->kex->hash, ssh->exhash, + s->our_kexinit, s->our_kexinitlen); + sfree(s->our_kexinit); + if (pktin->length > 5) + hash_string(ssh->kex->hash, ssh->exhash, + pktin->data + 5, pktin->length - 5); + + if (s->warn_kex) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, "key-exchange algorithm", + ssh->kex->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at kex warning", NULL, + 0, TRUE); + crStopV; + } + } + + if (s->warn_cscipher) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, + "client-to-server cipher", + s->cscipher_tobe->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at cipher warning", NULL, + 0, TRUE); + crStopV; + } + } + + if (s->warn_sccipher) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, + "server-to-client cipher", + s->sccipher_tobe->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at cipher warning", NULL, + 0, TRUE); + crStopV; } } + + if (s->ignorepkt) /* first_kex_packet_follows */ + crWaitUntilV(pktin); /* Ignore packet */ + } + + if (ssh->kex->main_type == KEXTYPE_DH) { + /* + * Work out the number of bits of key we will need from the + * key exchange. We start with the maximum key length of + * either cipher... + */ + { + int csbits, scbits; + + csbits = s->cscipher_tobe->keylen; + scbits = s->sccipher_tobe->keylen; + s->nbits = (csbits > scbits ? csbits : scbits); + } + /* The keys only have hlen-bit entropy, since they're based on + * a hash. So cap the key size at hlen bits. */ + if (s->nbits > ssh->kex->hash->hlen * 8) + s->nbits = ssh->kex->hash->hlen * 8; + + /* + * If we're doing Diffie-Hellman group exchange, start by + * requesting a group. + */ + if (!ssh->kex->pdata) { + logevent("Doing Diffie-Hellman group exchange"); + ssh->pkt_kctx = SSH2_PKTCTX_DHGEX; + /* + * Work out how big a DH group we will need to allow that + * much data. + */ + s->pbits = 512 << ((s->nbits - 1) / 64); + s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); + ssh2_pkt_adduint32(s->pktout, s->pbits); + ssh2_pkt_send_noqueue(ssh, s->pktout); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) { + bombout(("expected key exchange group packet from server")); + crStopV; + } + s->p = ssh2_pkt_getmp(pktin); + s->g = ssh2_pkt_getmp(pktin); + if (!s->p || !s->g) { + bombout(("unable to read mp-ints from incoming group packet")); + crStopV; + } + ssh->kex_ctx = dh_setup_gex(s->p, s->g); + s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; + s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; + } else { + ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP; + ssh->kex_ctx = dh_setup_group(ssh->kex); + s->kex_init_value = SSH2_MSG_KEXDH_INIT; + s->kex_reply_value = SSH2_MSG_KEXDH_REPLY; + logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"", + ssh->kex->groupname); + } + + logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s", + ssh->kex->hash->text_name); + /* + * Now generate and send e for Diffie-Hellman. + */ + set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */ + s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2); + s->pktout = ssh2_pkt_init(s->kex_init_value); + ssh2_pkt_addmp(s->pktout, s->e); + ssh2_pkt_send_noqueue(ssh, s->pktout); + + set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */ + crWaitUntilV(pktin); + if (pktin->type != s->kex_reply_value) { + bombout(("expected key exchange reply packet from server")); + crStopV; + } + set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */ + ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); + s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); + s->f = ssh2_pkt_getmp(pktin); + if (!s->f) { + bombout(("unable to parse key exchange reply packet")); + crStopV; + } + ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); + + s->K = dh_find_K(ssh->kex_ctx, s->f); + + /* We assume everything from now on will be quick, and it might + * involve user interaction. */ + set_busy_status(ssh->frontend, BUSY_NOT); + + hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen); + if (!ssh->kex->pdata) { + hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits); + hash_mpint(ssh->kex->hash, ssh->exhash, s->p); + hash_mpint(ssh->kex->hash, ssh->exhash, s->g); + } + hash_mpint(ssh->kex->hash, ssh->exhash, s->e); + hash_mpint(ssh->kex->hash, ssh->exhash, s->f); + + dh_cleanup(ssh->kex_ctx); + freebn(s->f); + if (!ssh->kex->pdata) { + freebn(s->g); + freebn(s->p); + } + } else { + logeventf(ssh, "Doing RSA key exchange with hash %s", + ssh->kex->hash->text_name); + ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX; + /* + * RSA key exchange. First expect a KEXRSA_PUBKEY packet + * from the server. + */ + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) { + bombout(("expected RSA public key packet from server")); + crStopV; + } + + ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); + hash_string(ssh->kex->hash, ssh->exhash, + s->hostkeydata, s->hostkeylen); + s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); + + { + char *keydata; + ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen); + s->rsakeydata = snewn(s->rsakeylen, char); + memcpy(s->rsakeydata, keydata, s->rsakeylen); + } + + s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen); + if (!s->rsakey) { + sfree(s->rsakeydata); + bombout(("unable to parse RSA public key from server")); + crStopV; + } + + hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen); + + /* + * Next, set up a shared secret K, of precisely KLEN - + * 2*HLEN - 49 bits, where KLEN is the bit length of the + * RSA key modulus and HLEN is the bit length of the hash + * we're using. + */ + { + int klen = ssh_rsakex_klen(s->rsakey); + int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49); + int i, byte = 0; + unsigned char *kstr1, *kstr2, *outstr; + int kstr1len, kstr2len, outstrlen; + + s->K = bn_power_2(nbits - 1); + + for (i = 0; i < nbits; i++) { + if ((i & 7) == 0) { + byte = random_byte(); + } + bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1); + } + + /* + * Encode this as an mpint. + */ + kstr1 = ssh2_mpint_fmt(s->K, &kstr1len); + kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char); + PUT_32BIT(kstr2, kstr1len); + memcpy(kstr2 + 4, kstr1, kstr1len); + + /* + * Encrypt it with the given RSA key. + */ + outstrlen = (klen + 7) / 8; + outstr = snewn(outstrlen, unsigned char); + ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len, + outstr, outstrlen, s->rsakey); + + /* + * And send it off in a return packet. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen); + ssh2_pkt_send_noqueue(ssh, s->pktout); + + hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen); + + sfree(kstr2); + sfree(kstr1); + sfree(outstr); + } + + ssh_rsakex_freekey(s->rsakey); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_KEXRSA_DONE) { + sfree(s->rsakeydata); + bombout(("expected signature packet from server")); + crStopV; + } + + ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); + + sfree(s->rsakeydata); + } + + hash_mpint(ssh->kex->hash, ssh->exhash, s->K); + assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash)); + ssh->kex->hash->final(ssh->exhash, s->exchange_hash); + + ssh->kex_ctx = NULL; + +#if 0 + debug(("Exchange hash is:\n")); + dmemdump(s->exchange_hash, ssh->kex->hash->hlen); +#endif + + if (!s->hkey || + !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen, + (char *)s->exchange_hash, + ssh->kex->hash->hlen)) { + bombout(("Server's host key did not match the signature supplied")); + crStopV; + } + + /* + * Authenticate remote host: verify host key. (We've already + * checked the signature of the exchange hash.) + */ + s->keystr = ssh->hostkey->fmtkey(s->hkey); + s->fingerprint = ssh->hostkey->fingerprint(s->hkey); + ssh_set_frozen(ssh, 1); + s->dlgret = verify_ssh_host_key(ssh->frontend, + ssh->savedhost, ssh->savedport, + ssh->hostkey->keytype, s->keystr, + s->fingerprint, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user host key response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at host key verification", NULL, + 0, TRUE); + crStopV; + } + if (!s->got_session_id) { /* don't bother logging this in rekeys */ + logevent("Host key fingerprint is:"); + logevent(s->fingerprint); + } + sfree(s->fingerprint); + sfree(s->keystr); + ssh->hostkey->freekey(s->hkey); + + /* + * The exchange hash from the very first key exchange is also + * the session id, used in session key construction and + * authentication. + */ + if (!s->got_session_id) { + assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id)); + memcpy(ssh->v2_session_id, s->exchange_hash, + sizeof(s->exchange_hash)); + ssh->v2_session_id_len = ssh->kex->hash->hlen; + assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id)); + s->got_session_id = TRUE; + } + + /* + * Send SSH2_MSG_NEWKEYS. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS); + ssh2_pkt_send_noqueue(ssh, s->pktout); + ssh->outgoing_data_size = 0; /* start counting from here */ + + /* + * We've sent client NEWKEYS, so create and initialise + * client-to-server session keys. + */ + if (ssh->cs_cipher_ctx) + ssh->cscipher->free_context(ssh->cs_cipher_ctx); + ssh->cscipher = s->cscipher_tobe; + ssh->cs_cipher_ctx = ssh->cscipher->make_context(); + + if (ssh->cs_mac_ctx) + ssh->csmac->free_context(ssh->cs_mac_ctx); + ssh->csmac = s->csmac_tobe; + ssh->cs_mac_ctx = ssh->csmac->make_context(); + + if (ssh->cs_comp_ctx) + ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); + ssh->cscomp = s->cscomp_tobe; + ssh->cs_comp_ctx = ssh->cscomp->compress_init(); + + /* + * Set IVs on client-to-server keys. Here we use the exchange + * hash from the _first_ key exchange. + */ + { + unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; + assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace); + assert((ssh->cscipher->keylen+7) / 8 <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace); + assert(ssh->cscipher->blksize <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace); + assert(ssh->csmac->len <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); + smemclr(keyspace, sizeof(keyspace)); + } + + logeventf(ssh, "Initialised %.200s client->server encryption", + ssh->cscipher->text_name); + logeventf(ssh, "Initialised %.200s client->server MAC algorithm", + ssh->csmac->text_name); + if (ssh->cscomp->text_name) + logeventf(ssh, "Initialised %s compression", + ssh->cscomp->text_name); + + /* + * Now our end of the key exchange is complete, we can send all + * our queued higher-layer packets. + */ + ssh->queueing = FALSE; + ssh2_pkt_queuesend(ssh); + + /* + * Expect SSH2_MSG_NEWKEYS from server. + */ + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_NEWKEYS) { + bombout(("expected new-keys packet from server")); + crStopV; } + ssh->incoming_data_size = 0; /* start counting from here */ + + /* + * We've seen server NEWKEYS, so create and initialise + * server-to-client session keys. + */ + if (ssh->sc_cipher_ctx) + ssh->sccipher->free_context(ssh->sc_cipher_ctx); + ssh->sccipher = s->sccipher_tobe; + ssh->sc_cipher_ctx = ssh->sccipher->make_context(); + + if (ssh->sc_mac_ctx) + ssh->scmac->free_context(ssh->sc_mac_ctx); + ssh->scmac = s->scmac_tobe; + ssh->sc_mac_ctx = ssh->scmac->make_context(); + + if (ssh->sc_comp_ctx) + ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); + ssh->sccomp = s->sccomp_tobe; + ssh->sc_comp_ctx = ssh->sccomp->decompress_init(); /* - * Work out the number of bits of key we will need from the key - * exchange. We start with the maximum key length of either - * cipher... + * Set IVs on server-to-client keys. Here we use the exchange + * hash from the _first_ key exchange. */ { - int csbits, scbits; + unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; + assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace); + assert((ssh->sccipher->keylen+7) / 8 <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace); + assert(ssh->sccipher->blksize <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace); + assert(ssh->scmac->len <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); + smemclr(keyspace, sizeof(keyspace)); + } + logeventf(ssh, "Initialised %.200s server->client encryption", + ssh->sccipher->text_name); + logeventf(ssh, "Initialised %.200s server->client MAC algorithm", + ssh->scmac->text_name); + if (ssh->sccomp->text_name) + logeventf(ssh, "Initialised %s decompression", + ssh->sccomp->text_name); + + /* + * Free shared secret. + */ + freebn(s->K); + + /* + * Key exchange is over. Loop straight back round if we have a + * deferred rekey reason. + */ + if (ssh->deferred_rekey_reason) { + logevent(ssh->deferred_rekey_reason); + pktin = NULL; + ssh->deferred_rekey_reason = NULL; + goto begin_key_exchange; + } + + /* + * Otherwise, schedule a timer for our next rekey. + */ + ssh->kex_in_progress = FALSE; + ssh->last_rekey = GETTICKCOUNT(); + if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) + ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC, + ssh2_timer, ssh); + + /* + * Now we're encrypting. Begin returning 1 to the protocol main + * function so that other things can run on top of the + * transport. If we ever see a KEXINIT, we must go back to the + * start. + * + * We _also_ go back to the start if we see pktin==NULL and + * inlen negative, because this is a special signal meaning + * `initiate client-driven rekey', and `in' contains a message + * giving the reason for the rekey. + * + * inlen==-1 means always initiate a rekey; + * inlen==-2 means that userauth has completed successfully and + * we should consider rekeying (for delayed compression). + */ + while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) || + (!pktin && inlen < 0))) { + wait_for_rekey: + if (!ssh->protocol_initial_phase_done) { + ssh->protocol_initial_phase_done = TRUE; + /* + * Allow authconn to initialise itself. + */ + do_ssh2_authconn(ssh, NULL, 0, NULL); + } + crReturnV; + } + if (pktin) { + logevent("Server initiated key re-exchange"); + } else { + if (inlen == -2) { + /* + * authconn has seen a USERAUTH_SUCCEEDED. Time to enable + * delayed compression, if it's available. + * + * draft-miller-secsh-compression-delayed-00 says that you + * negotiate delayed compression in the first key exchange, and + * both sides start compressing when the server has sent + * USERAUTH_SUCCESS. This has a race condition -- the server + * can't know when the client has seen it, and thus which incoming + * packets it should treat as compressed. + * + * Instead, we do the initial key exchange without offering the + * delayed methods, but note if the server offers them; when we + * get here, if a delayed method was available that was higher + * on our list than what we got, we initiate a rekey in which we + * _do_ list the delayed methods (and hopefully get it as a + * result). Subsequent rekeys will do the same. + */ + assert(!s->userauth_succeeded); /* should only happen once */ + s->userauth_succeeded = TRUE; + if (!s->pending_compression) + /* Can't see any point rekeying. */ + goto wait_for_rekey; /* this is utterly horrid */ + /* else fall through to rekey... */ + s->pending_compression = FALSE; + } + /* + * Now we've decided to rekey. + * + * Special case: if the server bug is set that doesn't + * allow rekeying, we give a different log message and + * continue waiting. (If such a server _initiates_ a rekey, + * we process it anyway!) + */ + if ((ssh->remote_bugs & BUG_SSH2_REKEY)) { + logeventf(ssh, "Server bug prevents key re-exchange (%s)", + (char *)in); + /* Reset the counters, so that at least this message doesn't + * hit the event log _too_ often. */ + ssh->outgoing_data_size = 0; + ssh->incoming_data_size = 0; + if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) { + ssh->next_rekey = + schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC, + ssh2_timer, ssh); + } + goto wait_for_rekey; /* this is still utterly horrid */ + } else { + logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in); + } + } + goto begin_key_exchange; + + crFinishV; +} + +/* + * Add data to an SSH-2 channel output buffer. + */ +static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, + int len) +{ + bufchain_add(&c->v.v2.outbuffer, buf, len); +} + +/* + * Attempt to send data on an SSH-2 channel. + */ +static int ssh2_try_send(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + struct Packet *pktout; + int ret; + + while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { + int len; + void *data; + bufchain_prefix(&c->v.v2.outbuffer, &data, &len); + if ((unsigned)len > c->v.v2.remwindow) + len = c->v.v2.remwindow; + if ((unsigned)len > c->v.v2.remmaxpkt) + len = c->v.v2.remmaxpkt; + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_addstring_start(pktout); + dont_log_data(ssh, pktout, PKTLOG_OMIT); + ssh2_pkt_addstring_data(pktout, data, len); + end_log_omission(ssh, pktout); + ssh2_pkt_send(ssh, pktout); + bufchain_consume(&c->v.v2.outbuffer, len); + c->v.v2.remwindow -= len; + } + + /* + * After having sent as much data as we can, return the amount + * still buffered. + */ + ret = bufchain_size(&c->v.v2.outbuffer); + + /* + * And if there's no data pending but we need to send an EOF, send + * it. + */ + if (!ret && c->pending_eof) + ssh_channel_try_eof(c); + + return ret; +} + +static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c) +{ + int bufsize; + if (c->closes & CLOSES_SENT_EOF) + return; /* don't send on channels we've EOFed */ + bufsize = ssh2_try_send(c); + if (bufsize == 0) { + switch (c->type) { + case CHAN_MAINSESSION: + /* stdin need not receive an unthrottle + * notification since it will be polled */ + break; + case CHAN_X11: + x11_unthrottle(c->u.x11.s); + break; + case CHAN_AGENT: + /* agent sockets are request/response and need no + * buffer management */ + break; + case CHAN_SOCKDATA: + pfd_unthrottle(c->u.pfd.s); + break; + } + } +} + +/* + * Set up most of a new ssh_channel for SSH-2. + */ +static void ssh2_channel_init(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + c->localid = alloc_channel_id(ssh); + c->closes = 0; + c->pending_eof = FALSE; + c->throttling_conn = FALSE; + c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin = + conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE; + c->v.v2.chanreq_head = NULL; + c->v.v2.throttle_state = UNTHROTTLED; + bufchain_init(&c->v.v2.outbuffer); +} + +/* + * Construct the common parts of a CHANNEL_OPEN. + */ +static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type) +{ + struct Packet *pktout; + + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); + ssh2_pkt_addstring(pktout, type); + ssh2_pkt_adduint32(pktout, c->localid); + ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */ + ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ + return pktout; +} + +/* + * CHANNEL_FAILURE doesn't come with any indication of what message + * caused it, so we have to keep track of the outstanding + * CHANNEL_REQUESTs ourselves. + */ +static void ssh2_queue_chanreq_handler(struct ssh_channel *c, + cchandler_fn_t handler, void *ctx) +{ + struct outstanding_channel_request *ocr = + snew(struct outstanding_channel_request); + + assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE))); + ocr->handler = handler; + ocr->ctx = ctx; + ocr->next = NULL; + if (!c->v.v2.chanreq_head) + c->v.v2.chanreq_head = ocr; + else + c->v.v2.chanreq_tail->next = ocr; + c->v.v2.chanreq_tail = ocr; +} + +/* + * Construct the common parts of a CHANNEL_REQUEST. If handler is not + * NULL then a reply will be requested and the handler will be called + * when it arrives. The returned packet is ready to have any + * request-specific data added and be sent. Note that if a handler is + * provided, it's essential that the request actually be sent. + * + * The handler will usually be passed the response packet in pktin. + * If pktin is NULL, this means that no reply will ever be forthcoming + * (e.g. because the entire connection is being destroyed) and the + * handler should free any storage it's holding. + */ +static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type, + cchandler_fn_t handler, void *ctx) +{ + struct Packet *pktout; + + assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE))); + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_addstring(pktout, type); + ssh2_pkt_addbool(pktout, handler != NULL); + if (handler != NULL) + ssh2_queue_chanreq_handler(c, handler, ctx); + return pktout; +} + +/* + * Potentially enlarge the window on an SSH-2 channel. + */ +static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *, + void *); +static void ssh2_set_window(struct ssh_channel *c, int newwin) +{ + Ssh ssh = c->ssh; + + /* + * Never send WINDOW_ADJUST for a channel that the remote side has + * already sent EOF on; there's no point, since it won't be + * sending any more data anyway. Ditto if _we've_ already sent + * CLOSE. + */ + if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE)) + return; + + /* + * If the remote end has a habit of ignoring maxpkt, limit the + * window so that it has no choice (assuming it doesn't ignore the + * window as well). + */ + if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT) + newwin = OUR_V2_MAXPKT; + + /* + * Only send a WINDOW_ADJUST if there's significantly more window + * available than the other end thinks there is. This saves us + * sending a WINDOW_ADJUST for every character in a shell session. + * + * "Significant" is arbitrarily defined as half the window size. + */ + if (newwin / 2 >= c->v.v2.locwindow) { + struct Packet *pktout; + unsigned *up; + + /* + * In order to keep track of how much window the client + * actually has available, we'd like it to acknowledge each + * WINDOW_ADJUST. We can't do that directly, so we accompany + * it with a CHANNEL_REQUEST that has to be acknowledged. + * + * This is only necessary if we're opening the window wide. + * If we're not, then throughput is being constrained by + * something other than the maximum window size anyway. + */ + if (newwin == c->v.v2.locmaxwin && + !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) { + up = snew(unsigned); + *up = newwin - c->v.v2.locwindow; + pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org", + ssh2_handle_winadj_response, up); + ssh2_pkt_send(ssh, pktout); + + if (c->v.v2.throttle_state != UNTHROTTLED) + c->v.v2.throttle_state = UNTHROTTLING; + } else { + /* Pretend the WINDOW_ADJUST was acked immediately. */ + c->v.v2.remlocwin = newwin; + c->v.v2.throttle_state = THROTTLED; + } + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow); + ssh2_pkt_send(ssh, pktout); + c->v.v2.locwindow = newwin; + } +} + +/* + * Find the channel associated with a message. If there's no channel, + * or it's not properly open, make a noise about it and return NULL. + */ +static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin) +{ + unsigned localid = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + + c = find234(ssh->channels, &localid, ssh_channelfind); + if (!c || + (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION && + pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) { + char *buf = dupprintf("Received %s for %s channel %u", + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, + pktin->type), + c ? "half-open" : "nonexistent", localid); + ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); + sfree(buf); + return NULL; + } + return c; +} + +static void ssh2_handle_winadj_response(struct ssh_channel *c, + struct Packet *pktin, void *ctx) +{ + unsigned *sizep = ctx; + + /* + * Winadj responses should always be failures. However, at least + * one server ("boks_sshd") is known to return SUCCESS for channel + * requests it's never heard of, such as "winadj@putty". Raised + * with foxt.com as bug 090916-090424, but for the sake of a quiet + * life, we don't worry about what kind of response we got. + */ + + c->v.v2.remlocwin += *sizep; + sfree(sizep); + /* + * winadj messages are only sent when the window is fully open, so + * if we get an ack of one, we know any pending unthrottle is + * complete. + */ + if (c->v.v2.throttle_state == UNTHROTTLING) + c->v.v2.throttle_state = UNTHROTTLED; +} + +static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c = ssh2_channel_msg(ssh, pktin); + struct outstanding_channel_request *ocr; + + if (!c) return; + ocr = c->v.v2.chanreq_head; + if (!ocr) { + ssh2_msg_unexpected(ssh, pktin); + return; + } + ocr->handler(c, pktin, ocr->ctx); + c->v.v2.chanreq_head = ocr->next; + sfree(ocr); + /* + * We may now initiate channel-closing procedures, if that + * CHANNEL_REQUEST was the last thing outstanding before we send + * CHANNEL_CLOSE. + */ + ssh2_channel_check_close(c); +} + +static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c; + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (!(c->closes & CLOSES_SENT_EOF)) { + c->v.v2.remwindow += ssh_pkt_getuint32(pktin); + ssh2_try_send_and_unthrottle(ssh, c); + } +} - csbits = s->cscipher_tobe->keylen; - scbits = s->sccipher_tobe->keylen; - s->nbits = (csbits > scbits ? csbits : scbits); +static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) +{ + char *data; + int length; + struct ssh_channel *c; + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA && + ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR) + return; /* extended but not stderr */ + ssh_pkt_getstring(pktin, &data, &length); + if (data) { + int bufsize = 0; + c->v.v2.locwindow -= length; + c->v.v2.remlocwin -= length; + switch (c->type) { + case CHAN_MAINSESSION: + bufsize = + from_backend(ssh->frontend, pktin->type == + SSH2_MSG_CHANNEL_EXTENDED_DATA, + data, length); + break; + case CHAN_X11: + bufsize = x11_send(c->u.x11.s, data, length); + break; + case CHAN_SOCKDATA: + bufsize = pfd_send(c->u.pfd.s, data, length); + break; + case CHAN_AGENT: + while (length > 0) { + if (c->u.a.lensofar < 4) { + unsigned int l = min(4 - c->u.a.lensofar, + (unsigned)length); + memcpy(c->u.a.msglen + c->u.a.lensofar, + data, l); + data += l; + length -= l; + c->u.a.lensofar += l; + } + if (c->u.a.lensofar == 4) { + c->u.a.totallen = + 4 + GET_32BIT(c->u.a.msglen); + c->u.a.message = snewn(c->u.a.totallen, + unsigned char); + memcpy(c->u.a.message, c->u.a.msglen, 4); + } + if (c->u.a.lensofar >= 4 && length > 0) { + unsigned int l = + min(c->u.a.totallen - c->u.a.lensofar, + (unsigned)length); + memcpy(c->u.a.message + c->u.a.lensofar, + data, l); + data += l; + length -= l; + c->u.a.lensofar += l; + } + if (c->u.a.lensofar == c->u.a.totallen) { + void *reply; + int replylen; + c->u.a.outstanding_requests++; + if (agent_query(c->u.a.message, + c->u.a.totallen, + &reply, &replylen, + ssh_agentf_callback, c)) + ssh_agentf_callback(c, reply, replylen); + sfree(c->u.a.message); + c->u.a.message = NULL; + c->u.a.lensofar = 0; + } + } + bufsize = 0; + break; + } + /* + * If it looks like the remote end hit the end of its window, + * and we didn't want it to do that, think about using a + * larger window. + */ + if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED && + c->v.v2.locmaxwin < 0x40000000) + c->v.v2.locmaxwin += OUR_V2_WINSIZE; + /* + * If we are not buffering too much data, + * enlarge the window again at the remote side. + * If we are buffering too much, we may still + * need to adjust the window if the server's + * sent excess data. + */ + ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ? + c->v.v2.locmaxwin - bufsize : 0); + /* + * If we're either buffering way too much data, or if we're + * buffering anything at all and we're in "simple" mode, + * throttle the whole channel. + */ + if ((bufsize > c->v.v2.locmaxwin || + (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) && + !c->throttling_conn) { + c->throttling_conn = 1; + ssh_throttle_conn(ssh, +1); + } + } +} + +static void ssh_channel_destroy(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + + switch (c->type) { + case CHAN_MAINSESSION: + ssh->mainchan = NULL; + update_specials_menu(ssh->frontend); + break; + case CHAN_X11: + if (c->u.x11.s != NULL) + x11_close(c->u.x11.s); + logevent("Forwarded X11 connection terminated"); + break; + case CHAN_AGENT: + sfree(c->u.a.message); + break; + case CHAN_SOCKDATA: + if (c->u.pfd.s != NULL) + pfd_close(c->u.pfd.s); + logevent("Forwarded port closed"); + break; + } + + del234(ssh->channels, c); + if (ssh->version == 2) { + bufchain_clear(&c->v.v2.outbuffer); + assert(c->v.v2.chanreq_head == NULL); + } + sfree(c); + + /* + * See if that was the last channel left open. + * (This is only our termination condition if we're + * not running in -N mode.) + */ + if (ssh->version == 2 && + !conf_get_int(ssh->conf, CONF_ssh_no_shell) && + count234(ssh->channels) == 0) { + /* + * We used to send SSH_MSG_DISCONNECT here, + * because I'd believed that _every_ conforming + * SSH-2 connection had to end with a disconnect + * being sent by at least one side; apparently + * I was wrong and it's perfectly OK to + * unceremoniously slam the connection shut + * when you're done, and indeed OpenSSH feels + * this is more polite than sending a + * DISCONNECT. So now we don't. + */ + ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE); + } +} + +static void ssh2_channel_check_close(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + struct Packet *pktout; + + if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) || + c->type == CHAN_ZOMBIE) && + !c->v.v2.chanreq_head && + !(c->closes & CLOSES_SENT_CLOSE)) { + /* + * We have both sent and received EOF (or the channel is a + * zombie), and we have no outstanding channel requests, which + * means the channel is in final wind-up. But we haven't sent + * CLOSE, so let's do so now. + */ + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE; } - /* The keys only have 160-bit entropy, since they're based on - * a SHA-1 hash. So cap the key size at 160 bits. */ - if (s->nbits > 160) - s->nbits = 160; - /* - * If we're doing Diffie-Hellman group exchange, start by - * requesting a group. - */ - if (ssh->kex == &ssh_diffiehellman_gex) { - logevent("Doing Diffie-Hellman group exchange"); - ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX; - /* - * Work out how big a DH group we will need to allow that - * much data. - */ - s->pbits = 512 << ((s->nbits - 1) / 64); - ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST); - ssh2_pkt_adduint32(ssh, s->pbits); - ssh2_pkt_send(ssh); - - crWaitUntil(ispkt); - if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) { - bombout(("expected key exchange group packet from server")); - crStop(0); - } - s->p = ssh2_pkt_getmp(ssh); - s->g = ssh2_pkt_getmp(ssh); - ssh->kex_ctx = dh_setup_group(s->p, s->g); - s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; - s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; - } else { - ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1; - ssh->kex_ctx = dh_setup_group1(); - s->kex_init_value = SSH2_MSG_KEXDH_INIT; - s->kex_reply_value = SSH2_MSG_KEXDH_REPLY; + if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) { + assert(c->v.v2.chanreq_head == NULL); + /* + * We have both sent and received CLOSE, which means we're + * completely done with the channel. + */ + ssh_channel_destroy(c); } +} - logevent("Doing Diffie-Hellman key exchange"); - /* - * Now generate and send e for Diffie-Hellman. - */ - s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2); - ssh2_pkt_init(ssh, s->kex_init_value); - ssh2_pkt_addmp(ssh, s->e); - ssh2_pkt_send(ssh); - - crWaitUntil(ispkt); - if (ssh->pktin.type != s->kex_reply_value) { - bombout(("expected key exchange reply packet from server")); - crStop(0); +static void ssh2_channel_got_eof(struct ssh_channel *c) +{ + if (c->closes & CLOSES_RCVD_EOF) + return; /* already seen EOF */ + c->closes |= CLOSES_RCVD_EOF; + + if (c->type == CHAN_X11) { + x11_send_eof(c->u.x11.s); + } else if (c->type == CHAN_AGENT) { + if (c->u.a.outstanding_requests == 0) { + /* Manufacture an outgoing EOF in response to the incoming one. */ + sshfwd_write_eof(c); + } + } else if (c->type == CHAN_SOCKDATA) { + pfd_send_eof(c->u.pfd.s); + } else if (c->type == CHAN_MAINSESSION) { + Ssh ssh = c->ssh; + + if (!ssh->sent_console_eof && + (from_backend_eof(ssh->frontend) || ssh->got_pty)) { + /* + * Either from_backend_eof told us that the front end + * wants us to close the outgoing side of the connection + * as soon as we see EOF from the far end, or else we've + * unilaterally decided to do that because we've allocated + * a remote pty and hence EOF isn't a particularly + * meaningful concept. + */ + sshfwd_write_eof(c); + } + ssh->sent_console_eof = TRUE; } - ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen); - s->f = ssh2_pkt_getmp(ssh); - ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen); - s->K = dh_find_K(ssh->kex_ctx, s->f); + ssh2_channel_check_close(c); +} - sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen); - if (ssh->kex == &ssh_diffiehellman_gex) { - sha_uint32(&ssh->exhash, s->pbits); - sha_mpint(&ssh->exhash, s->p); - sha_mpint(&ssh->exhash, s->g); - } - sha_mpint(&ssh->exhash, s->e); - sha_mpint(&ssh->exhash, s->f); - sha_mpint(&ssh->exhash, s->K); - SHA_Final(&ssh->exhash, s->exchange_hash); +static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c; - dh_cleanup(ssh->kex_ctx); - ssh->kex_ctx = NULL; + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + ssh2_channel_got_eof(c); +} -#if 0 - debug(("Exchange hash is:\n")); - dmemdump(s->exchange_hash, 20); -#endif +static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c; - s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); - if (!s->hkey || - !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen, - (char *)s->exchange_hash, 20)) { - bombout(("Server's host key did not match the signature supplied")); - crStop(0); - } + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; /* - * Authenticate remote host: verify host key. (We've already - * checked the signature of the exchange hash.) + * When we receive CLOSE on a channel, we assume it comes with an + * implied EOF if we haven't seen EOF yet. */ - s->keystr = ssh->hostkey->fmtkey(s->hkey); - s->fingerprint = ssh->hostkey->fingerprint(s->hkey); - verify_ssh_host_key(ssh->frontend, - ssh->savedhost, ssh->savedport, ssh->hostkey->keytype, - s->keystr, s->fingerprint); - if (s->first_kex) { /* don't bother logging this in rekeys */ - logevent("Host key fingerprint is:"); - logevent(s->fingerprint); - } - sfree(s->fingerprint); - sfree(s->keystr); - ssh->hostkey->freekey(s->hkey); + ssh2_channel_got_eof(c); /* - * Send SSH2_MSG_NEWKEYS. + * And we also send an outgoing EOF, if we haven't already, on the + * assumption that CLOSE is a pretty forceful announcement that + * the remote side is doing away with the entire channel. (If it + * had wanted to send us EOF and continue receiving data from us, + * it would have just sent CHANNEL_EOF.) */ - ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS); - ssh2_pkt_send(ssh); + if (!(c->closes & CLOSES_SENT_EOF)) { + /* + * Make sure we don't read any more from whatever our local + * data source is for this channel. + */ + switch (c->type) { + case CHAN_MAINSESSION: + ssh->send_ok = 0; /* stop trying to read from stdin */ + break; + case CHAN_X11: + x11_override_throttle(c->u.x11.s, 1); + break; + case CHAN_SOCKDATA: + pfd_override_throttle(c->u.pfd.s, 1); + break; + } - /* - * Expect SSH2_MSG_NEWKEYS from server. - */ - crWaitUntil(ispkt); - if (ssh->pktin.type != SSH2_MSG_NEWKEYS) { - bombout(("expected new-keys packet from server")); - crStop(0); + /* + * Abandon any buffered data we still wanted to send to this + * channel. Receiving a CHANNEL_CLOSE is an indication that + * the server really wants to get on and _destroy_ this + * channel, and it isn't going to send us any further + * WINDOW_ADJUSTs to permit us to send pending stuff. + */ + bufchain_clear(&c->v.v2.outbuffer); + + /* + * Send outgoing EOF. + */ + sshfwd_write_eof(c); } /* - * Create and initialise session keys. + * Now process the actual close. */ - if (ssh->cs_cipher_ctx) - ssh->cscipher->free_context(ssh->cs_cipher_ctx); - ssh->cscipher = s->cscipher_tobe; - ssh->cs_cipher_ctx = ssh->cscipher->make_context(); + if (!(c->closes & CLOSES_RCVD_CLOSE)) { + c->closes |= CLOSES_RCVD_CLOSE; + ssh2_channel_check_close(c); + } +} - if (ssh->sc_cipher_ctx) - ssh->sccipher->free_context(ssh->sc_cipher_ctx); - ssh->sccipher = s->sccipher_tobe; - ssh->sc_cipher_ctx = ssh->sccipher->make_context(); +static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c; - if (ssh->cs_mac_ctx) - ssh->csmac->free_context(ssh->cs_mac_ctx); - ssh->csmac = s->csmac_tobe; - ssh->cs_mac_ctx = ssh->csmac->make_context(); + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (c->type != CHAN_SOCKDATA_DORMANT) + return; /* dunno why they're confirming this */ + c->remoteid = ssh_pkt_getuint32(pktin); + c->halfopen = FALSE; + c->type = CHAN_SOCKDATA; + c->v.v2.remwindow = ssh_pkt_getuint32(pktin); + c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); + if (c->u.pfd.s) + pfd_confirm(c->u.pfd.s); + if (c->pending_eof) + ssh_channel_try_eof(c); +} - if (ssh->sc_mac_ctx) - ssh->scmac->free_context(ssh->sc_mac_ctx); - ssh->scmac = s->scmac_tobe; - ssh->sc_mac_ctx = ssh->scmac->make_context(); +static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) +{ + static const char *const reasons[] = { + "", + "Administratively prohibited", + "Connect failed", + "Unknown channel type", + "Resource shortage", + }; + unsigned reason_code; + char *reason_string; + int reason_length; + struct ssh_channel *c; + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (c->type != CHAN_SOCKDATA_DORMANT) + return; /* dunno why they're failing this */ - if (ssh->cs_comp_ctx) - ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); - ssh->cscomp = s->cscomp_tobe; - ssh->cs_comp_ctx = ssh->cscomp->compress_init(); + reason_code = ssh_pkt_getuint32(pktin); + if (reason_code >= lenof(reasons)) + reason_code = 0; /* ensure reasons[reason_code] in range */ + ssh_pkt_getstring(pktin, &reason_string, &reason_length); + logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]", + reasons[reason_code], reason_length, reason_string); - if (ssh->sc_comp_ctx) - ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); - ssh->sccomp = s->sccomp_tobe; - ssh->sc_comp_ctx = ssh->sccomp->decompress_init(); + pfd_close(c->u.pfd.s); + + del234(ssh->channels, c); + sfree(c); +} + +static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) +{ + char *type; + int typelen, want_reply; + int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */ + struct ssh_channel *c; + struct Packet *pktout; + + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + ssh_pkt_getstring(pktin, &type, &typelen); + want_reply = ssh2_pkt_getbool(pktin); /* - * Set IVs after keys. Here we use the exchange hash from the - * _first_ key exchange. + * Having got the channel number, we now look at + * the request type string to see if it's something + * we recognise. */ - { - unsigned char keyspace[40]; - if (s->first_kex) - memcpy(ssh->v2_session_id, s->exchange_hash, - sizeof(s->exchange_hash)); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace); - ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace); - ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace); - ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace); - ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace); - ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace); - ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); + if (c == ssh->mainchan) { + /* + * We recognise "exit-status" and "exit-signal" on + * the primary channel. + */ + if (typelen == 11 && + !memcmp(type, "exit-status", 11)) { + + ssh->exitcode = ssh_pkt_getuint32(pktin); + logeventf(ssh, "Server sent command exit status %d", + ssh->exitcode); + reply = SSH2_MSG_CHANNEL_SUCCESS; + + } else if (typelen == 11 && + !memcmp(type, "exit-signal", 11)) { + + int is_plausible = TRUE, is_int = FALSE; + char *fmt_sig = "", *fmt_msg = ""; + char *msg; + int msglen = 0, core = FALSE; + /* ICK: older versions of OpenSSH (e.g. 3.4p1) + * provide an `int' for the signal, despite its + * having been a `string' in the drafts of RFC 4254 since at + * least 2001. (Fixed in session.c 1.147.) Try to + * infer which we can safely parse it as. */ + { + unsigned char *p = pktin->body + + pktin->savedpos; + long len = pktin->length - pktin->savedpos; + unsigned long num = GET_32BIT(p); /* what is it? */ + /* If it's 0, it hardly matters; assume string */ + if (num == 0) { + is_int = FALSE; + } else { + int maybe_int = FALSE, maybe_str = FALSE; +#define CHECK_HYPOTHESIS(offset, result) \ + do \ + { \ + int q = toint(offset); \ + if (q >= 0 && q+4 <= len) { \ + q = toint(q + 4 + GET_32BIT(p+q)); \ + if (q >= 0 && q+4 <= len && \ + ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \ + q == len) \ + result = TRUE; \ + } \ + } while(0) + CHECK_HYPOTHESIS(4+1, maybe_int); + CHECK_HYPOTHESIS(4+num+1, maybe_str); +#undef CHECK_HYPOTHESIS + if (maybe_int && !maybe_str) + is_int = TRUE; + else if (!maybe_int && maybe_str) + is_int = FALSE; + else + /* Crikey. Either or neither. Panic. */ + is_plausible = FALSE; + } + } + ssh->exitcode = 128; /* means `unknown signal' */ + if (is_plausible) { + if (is_int) { + /* Old non-standard OpenSSH. */ + int signum = ssh_pkt_getuint32(pktin); + fmt_sig = dupprintf(" %d", signum); + ssh->exitcode = 128 + signum; + } else { + /* As per RFC 4254. */ + char *sig; + int siglen; + ssh_pkt_getstring(pktin, &sig, &siglen); + /* Signal name isn't supposed to be blank, but + * let's cope gracefully if it is. */ + if (siglen) { + fmt_sig = dupprintf(" \"%.*s\"", + siglen, sig); + } + + /* + * Really hideous method of translating the + * signal description back into a locally + * meaningful number. + */ + + if (0) + ; +#define TRANSLATE_SIGNAL(s) \ + else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \ + ssh->exitcode = 128 + SIG ## s +#ifdef SIGABRT + TRANSLATE_SIGNAL(ABRT); +#endif +#ifdef SIGALRM + TRANSLATE_SIGNAL(ALRM); +#endif +#ifdef SIGFPE + TRANSLATE_SIGNAL(FPE); +#endif +#ifdef SIGHUP + TRANSLATE_SIGNAL(HUP); +#endif +#ifdef SIGILL + TRANSLATE_SIGNAL(ILL); +#endif +#ifdef SIGINT + TRANSLATE_SIGNAL(INT); +#endif +#ifdef SIGKILL + TRANSLATE_SIGNAL(KILL); +#endif +#ifdef SIGPIPE + TRANSLATE_SIGNAL(PIPE); +#endif +#ifdef SIGQUIT + TRANSLATE_SIGNAL(QUIT); +#endif +#ifdef SIGSEGV + TRANSLATE_SIGNAL(SEGV); +#endif +#ifdef SIGTERM + TRANSLATE_SIGNAL(TERM); +#endif +#ifdef SIGUSR1 + TRANSLATE_SIGNAL(USR1); +#endif +#ifdef SIGUSR2 + TRANSLATE_SIGNAL(USR2); +#endif +#undef TRANSLATE_SIGNAL + else + ssh->exitcode = 128; + } + core = ssh2_pkt_getbool(pktin); + ssh_pkt_getstring(pktin, &msg, &msglen); + if (msglen) { + fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg); + } + /* ignore lang tag */ + } /* else don't attempt to parse */ + logeventf(ssh, "Server exited on signal%s%s%s", + fmt_sig, core ? " (core dumped)" : "", + fmt_msg); + if (*fmt_sig) sfree(fmt_sig); + if (*fmt_msg) sfree(fmt_msg); + reply = SSH2_MSG_CHANNEL_SUCCESS; + + } + } else { + /* + * This is a channel request we don't know + * about, so we now either ignore the request + * or respond with CHANNEL_FAILURE, depending + * on want_reply. + */ + reply = SSH2_MSG_CHANNEL_FAILURE; } - logeventf(ssh, "Initialised %.200s client->server encryption", - ssh->cscipher->text_name); - logeventf(ssh, "Initialised %.200s server->client encryption", - ssh->sccipher->text_name); - if (ssh->cscomp->text_name) - logeventf(ssh, "Initialised %s compression", - ssh->cscomp->text_name); - if (ssh->sccomp->text_name) - logeventf(ssh, "Initialised %s decompression", - ssh->sccomp->text_name); + if (want_reply) { + pktout = ssh2_pkt_init(reply); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + } +} + +static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin) +{ + char *type; + int typelen, want_reply; + struct Packet *pktout; + + ssh_pkt_getstring(pktin, &type, &typelen); + want_reply = ssh2_pkt_getbool(pktin); /* - * If this is the first key exchange phase, we must pass the - * SSH2_MSG_NEWKEYS packet to the next layer, not because it - * wants to see it but because it will need time to initialise - * itself before it sees an actual packet. In subsequent key - * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because - * it would only confuse the layer above. + * We currently don't support any global requests + * at all, so we either ignore the request or + * respond with REQUEST_FAILURE, depending on + * want_reply. */ - if (!s->first_kex) { - crReturn(0); + if (want_reply) { + pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE); + ssh2_pkt_send(ssh, pktout); } - s->first_kex = 0; +} - /* - * Now we're encrypting. Begin returning 1 to the protocol main - * function so that other things can run on top of the - * transport. If we ever see a KEXINIT, we must go back to the - * start. - */ - while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) { - crReturn(1); +static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) +{ + char *type; + int typelen; + char *peeraddr; + int peeraddrlen; + int peerport; + char *error = NULL; + struct ssh_channel *c; + unsigned remid, winsize, pktsize; + struct Packet *pktout; + + ssh_pkt_getstring(pktin, &type, &typelen); + c = snew(struct ssh_channel); + c->ssh = ssh; + + remid = ssh_pkt_getuint32(pktin); + winsize = ssh_pkt_getuint32(pktin); + pktsize = ssh_pkt_getuint32(pktin); + + if (typelen == 3 && !memcmp(type, "x11", 3)) { + char *addrstr; + const char *x11err; + + ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); + addrstr = snewn(peeraddrlen+1, char); + memcpy(addrstr, peeraddr, peeraddrlen); + addrstr[peeraddrlen] = '\0'; + peerport = ssh_pkt_getuint32(pktin); + + logeventf(ssh, "Received X11 connect request from %s:%d", + addrstr, peerport); + + if (!ssh->X11_fwd_enabled) + error = "X11 forwarding is not enabled"; + else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c, + addrstr, peerport, ssh->conf)) != NULL) { + logeventf(ssh, "Local X11 connection failed: %s", x11err); + error = "Unable to open an X11 connection"; + } else { + logevent("Opening X11 forward connection succeeded"); + c->type = CHAN_X11; + } + + sfree(addrstr); + } else if (typelen == 15 && + !memcmp(type, "forwarded-tcpip", 15)) { + struct ssh_rportfwd pf, *realpf; + char *dummy; + int dummylen; + ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */ + pf.sport = ssh_pkt_getuint32(pktin); + ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); + peerport = ssh_pkt_getuint32(pktin); + realpf = find234(ssh->rportfwds, &pf, NULL); + logeventf(ssh, "Received remote port %d open request " + "from %s:%d", pf.sport, peeraddr, peerport); + if (realpf == NULL) { + error = "Remote port is not recognised"; + } else { + const char *e = pfd_newconnect(&c->u.pfd.s, + realpf->dhost, + realpf->dport, c, + ssh->conf, + realpf->pfrec->addressfamily); + logeventf(ssh, "Attempting to forward remote port to " + "%s:%d", realpf->dhost, realpf->dport); + if (e != NULL) { + logeventf(ssh, "Port open failed: %s", e); + error = "Port open failed"; + } else { + logevent("Forwarded port opened successfully"); + c->type = CHAN_SOCKDATA; + } + } + } else if (typelen == 22 && + !memcmp(type, "auth-agent@openssh.com", 22)) { + if (!ssh->agentfwd_enabled) + error = "Agent forwarding is not enabled"; + else { + c->type = CHAN_AGENT; /* identify channel type */ + c->u.a.lensofar = 0; + c->u.a.outstanding_requests = 0; + } + } else { + error = "Unsupported channel type requested"; } - logevent("Server initiated key re-exchange"); - goto begin_key_exchange; - crFinish(1); + c->remoteid = remid; + c->halfopen = FALSE; + if (error) { + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED); + ssh2_pkt_addstring(pktout, error); + ssh2_pkt_addstring(pktout, "en"); /* language tag */ + ssh2_pkt_send(ssh, pktout); + logeventf(ssh, "Rejected channel open: %s", error); + sfree(c); + } else { + ssh2_channel_init(c); + c->v.v2.remwindow = winsize; + c->v.v2.remmaxpkt = pktsize; + add234(ssh->channels, c); + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_adduint32(pktout, c->localid); + ssh2_pkt_adduint32(pktout, c->v.v2.locwindow); + ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ + ssh2_pkt_send(ssh, pktout); + } } /* - * Add data to an SSH2 channel output buffer. + * Buffer banner messages for later display at some convenient point, + * if we're going to display them. */ -static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, - int len) +static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin) { - bufchain_add(&c->v.v2.outbuffer, buf, len); + /* Arbitrary limit to prevent unbounded inflation of buffer */ + if (conf_get_int(ssh->conf, CONF_ssh_show_banner) && + bufchain_size(&ssh->banner) <= 131072) { + char *banner = NULL; + int size = 0; + ssh_pkt_getstring(pktin, &banner, &size); + if (banner) + bufchain_add(&ssh->banner, banner, size); + } } -/* - * Attempt to send data on an SSH2 channel. - */ -static int ssh2_try_send(struct ssh_channel *c) +/* Helper function to deal with sending tty modes for "pty-req" */ +static void ssh2_send_ttymode(void *data, char *mode, char *val) { + struct Packet *pktout = (struct Packet *)data; + int i = 0; + unsigned int arg = 0; + while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; + if (i == lenof(ssh_ttymodes)) return; + switch (ssh_ttymodes[i].type) { + case TTY_OP_CHAR: + arg = ssh_tty_parse_specchar(val); + break; + case TTY_OP_BOOL: + arg = ssh_tty_parse_boolean(val); + break; + } + ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); + ssh2_pkt_adduint32(pktout, arg); +} + +static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin, + void *ctx) +{ + struct ssh2_setup_x11_state { + int crLine; + }; Ssh ssh = c->ssh; + struct Packet *pktout; + crStateP(ssh2_setup_x11_state, ctx); - while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { - int len; - void *data; - bufchain_prefix(&c->v.v2.outbuffer, &data, &len); - if ((unsigned)len > c->v.v2.remwindow) - len = c->v.v2.remwindow; - if ((unsigned)len > c->v.v2.remmaxpkt) - len = c->v.v2.remmaxpkt; - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA); - ssh2_pkt_adduint32(ssh, c->remoteid); - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, data, len); - ssh2_pkt_send(ssh); - bufchain_consume(&c->v.v2.outbuffer, len); - c->v.v2.remwindow -= len; - } + crBeginState; + logevent("Requesting X11 forwarding"); + pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req", + ssh2_setup_x11, s); + ssh2_pkt_addbool(pktout, 0); /* many connections */ + ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname); /* - * After having sent as much data as we can, return the amount - * still buffered. + * Note that while we blank the X authentication data here, we don't + * take any special action to blank the start of an X11 channel, + * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection + * without having session blanking enabled is likely to leak your + * cookie into the log. */ - return bufchain_size(&c->v.v2.outbuffer); + dont_log_password(ssh, pktout, PKTLOG_BLANK); + ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring); + end_log_omission(ssh, pktout); + ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum); + ssh2_pkt_send(ssh, pktout); + + /* Wait to be called back with either a response packet, or NULL + * meaning clean up and free our data */ + crReturnV; + + if (pktin) { + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { + logevent("X11 forwarding enabled"); + ssh->X11_fwd_enabled = TRUE; + } else + logevent("X11 forwarding refused"); + } + + crFinishFreeV; } -/* - * Potentially enlarge the window on an SSH2 channel. - */ -static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) +static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin, + void *ctx) +{ + struct ssh2_setup_agent_state { + int crLine; + }; + Ssh ssh = c->ssh; + struct Packet *pktout; + crStateP(ssh2_setup_agent_state, ctx); + + crBeginState; + + logevent("Requesting OpenSSH-style agent forwarding"); + pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com", + ssh2_setup_agent, s); + ssh2_pkt_send(ssh, pktout); + + /* Wait to be called back with either a response packet, or NULL + * meaning clean up and free our data */ + crReturnV; + + if (pktin) { + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { + logevent("Agent forwarding enabled"); + ssh->agentfwd_enabled = TRUE; + } else + logevent("Agent forwarding refused"); + } + + crFinishFreeV; +} + +static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin, + void *ctx) +{ + struct ssh2_setup_pty_state { + int crLine; + }; + Ssh ssh = c->ssh; + struct Packet *pktout; + crStateP(ssh2_setup_pty_state, ctx); + + crBeginState; + + /* Unpick the terminal-speed string. */ + /* XXX perhaps we should allow no speeds to be sent. */ + ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ + sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed); + /* Build the pty request. */ + pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req", + ssh2_setup_pty, s); + ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype)); + ssh2_pkt_adduint32(pktout, ssh->term_width); + ssh2_pkt_adduint32(pktout, ssh->term_height); + ssh2_pkt_adduint32(pktout, 0); /* pixel width */ + ssh2_pkt_adduint32(pktout, 0); /* pixel height */ + ssh2_pkt_addstring_start(pktout); + parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout); + ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED); + ssh2_pkt_adduint32(pktout, ssh->ispeed); + ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED); + ssh2_pkt_adduint32(pktout, ssh->ospeed); + ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */ + ssh2_pkt_send(ssh, pktout); + ssh->state = SSH_STATE_INTERMED; + + /* Wait to be called back with either a response packet, or NULL + * meaning clean up and free our data */ + crReturnV; + + if (pktin) { + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { + logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", + ssh->ospeed, ssh->ispeed); + ssh->got_pty = TRUE; + } else { + c_write_str(ssh, "Server refused to allocate pty\r\n"); + ssh->editing = ssh->echoing = 1; + } + } + + crFinishFreeV; +} + +static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin, + void *ctx) { + struct ssh2_setup_env_state { + int crLine; + int num_env, env_left, env_ok; + }; Ssh ssh = c->ssh; + struct Packet *pktout; + crStateP(ssh2_setup_env_state, ctx); + + crBeginState; /* - * Never send WINDOW_ADJUST for a channel that the remote side - * already thinks it's closed; there's no point, since it won't - * be sending any more data anyway. + * Send environment variables. + * + * Simplest thing here is to send all the requests at once, and + * then wait for a whole bunch of successes or failures. */ - if (c->closes != 0) - return; + s->num_env = 0; + { + char *key, *val; - if (newwin > c->v.v2.locwindow) { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST); - ssh2_pkt_adduint32(ssh, c->remoteid); - ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow); - ssh2_pkt_send(ssh); - c->v.v2.locwindow = newwin; + for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key); + val != NULL; + val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) { + pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s); + ssh2_pkt_addstring(pktout, key); + ssh2_pkt_addstring(pktout, val); + ssh2_pkt_send(ssh, pktout); + + s->num_env++; + } + if (s->num_env) + logeventf(ssh, "Sent %d environment variables", s->num_env); + } + + if (s->num_env) { + s->env_ok = 0; + s->env_left = s->num_env; + + while (s->env_left > 0) { + /* Wait to be called back with either a response packet, + * or NULL meaning clean up and free our data */ + crReturnV; + if (!pktin) goto out; + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) + s->env_ok++; + s->env_left--; + } + + if (s->env_ok == s->num_env) { + logevent("All environment variables successfully set"); + } else if (s->env_ok == 0) { + logevent("All environment variables refused"); + c_write_str(ssh, "Server refused to set environment variables\r\n"); + } else { + logeventf(ssh, "%d environment variables refused", + s->num_env - s->env_ok); + c_write_str(ssh, "Server refused to set all environment variables\r\n"); + } } + out:; + crFinishFreeV; } /* - * Handle the SSH2 userauth and connection layers. + * Handle the SSH-2 userauth and connection layers. */ -static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) +static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin) +{ + do_ssh2_authconn(ssh, NULL, 0, pktin); +} + +static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin, + void *ctx) +{ + do_ssh2_authconn(c->ssh, NULL, 0, pktin); +} + +static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin) { struct do_ssh2_authconn_state { - enum { - AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, - AUTH_PASSWORD, - AUTH_KEYBOARD_INTERACTIVE - } method; + int crLine; enum { AUTH_TYPE_NONE, AUTH_TYPE_PUBLICKEY, AUTH_TYPE_PUBLICKEY_OFFER_LOUD, AUTH_TYPE_PUBLICKEY_OFFER_QUIET, AUTH_TYPE_PASSWORD, + AUTH_TYPE_GSSAPI, /* always QUIET */ AUTH_TYPE_KEYBOARD_INTERACTIVE, AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET } type; + int done_service_req; int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; - int tried_pubkey_config, tried_agent, tried_keyb_inter; - int kbd_inter_running; - int we_are_in; - int num_prompts, curr_prompt, echo; - char username[100]; + int tried_pubkey_config, done_agent; +#ifndef NO_GSSAPI + int can_gssapi; + int tried_gssapi; +#endif + int kbd_inter_refused; + int we_are_in, userauth_success; + prompts_t *cur_prompt; + int num_prompts; + char *username; + char *password; int got_username; - char pwprompt[200]; - char password[100]; void *publickey_blob; int publickey_bloblen; - unsigned char request[5], *response, *p; - int responselen; + int publickey_encrypted; + char *publickey_algorithm; + char *publickey_comment; + unsigned char agent_request[5], *agent_response, *agentp; + int agent_responselen; + unsigned char *pkblob_in_agent; int keyi, nkeys; - int authed; char *pkblob, *alg, *commentp; int pklen, alglen, commentlen; int siglen, retlen, len; char *q, *agentreq, *ret; int try_send; + struct Packet *pktout; + Filename *keyfile; +#ifndef NO_GSSAPI + struct ssh_gss_library *gsslib; + Ssh_gss_ctx gss_ctx; + Ssh_gss_buf gss_buf; + Ssh_gss_buf gss_rcvtok, gss_sndtok; + Ssh_gss_name gss_srv_name; + Ssh_gss_stat gss_stat; +#endif }; crState(do_ssh2_authconn_state); - crBegin(ssh->do_ssh2_authconn_crstate); + crBeginState; + + /* Register as a handler for all the messages this coroutine handles. */ + ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn; + /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */ + /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */ + ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn; + + s->done_service_req = FALSE; + s->we_are_in = s->userauth_success = FALSE; +#ifndef NO_GSSAPI + s->tried_gssapi = FALSE; +#endif + + if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) { + /* + * Request userauth protocol, and await a response to it. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); + ssh2_pkt_addstring(s->pktout, "ssh-userauth"); + ssh2_pkt_send(ssh, s->pktout); + crWaitUntilV(pktin); + if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) + s->done_service_req = TRUE; + } + if (!s->done_service_req) { + /* + * Request connection protocol directly, without authentication. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + ssh2_pkt_send(ssh, s->pktout); + crWaitUntilV(pktin); + if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) { + s->we_are_in = TRUE; /* no auth required */ + } else { + bombout(("Server refused service request")); + crStopV; + } + } + + /* Arrange to be able to deal with any BANNERs that come in. + * (We do this now as packets may come in during the next bit.) */ + bufchain_init(&ssh->banner); + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = + ssh2_msg_userauth_banner; /* - * Request userauth protocol, and await a response to it. + * Misc one-time setup for authentication. */ - ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST); - ssh2_pkt_addstring(ssh, "ssh-userauth"); - ssh2_pkt_send(ssh); - crWaitUntilV(ispkt); - if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) { - bombout(("Server refused user authentication protocol")); - crStopV; + s->publickey_blob = NULL; + if (!s->we_are_in) { + + /* + * Load the public half of any configured public key file + * for later use. + */ + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + if (!filename_is_null(s->keyfile)) { + int keytype; + logeventf(ssh, "Reading private key file \"%.150s\"", + filename_to_str(s->keyfile)); + keytype = key_type(s->keyfile); + if (keytype == SSH_KEYTYPE_SSH2) { + const char *error; + s->publickey_blob = + ssh2_userkey_loadpub(s->keyfile, + &s->publickey_algorithm, + &s->publickey_bloblen, + &s->publickey_comment, &error); + if (s->publickey_blob) { + s->publickey_encrypted = + ssh2_userkey_encrypted(s->keyfile, NULL); + } else { + char *msgbuf; + logeventf(ssh, "Unable to load private key (%s)", + error); + msgbuf = dupprintf("Unable to load private key file " + "\"%.150s\" (%s)\r\n", + filename_to_str(s->keyfile), + error); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + } + } else { + char *msgbuf; + logeventf(ssh, "Unable to use this key file (%s)", + key_type_to_str(keytype)); + msgbuf = dupprintf("Unable to use key file \"%.150s\"" + " (%s)\r\n", + filename_to_str(s->keyfile), + key_type_to_str(keytype)); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + s->publickey_blob = NULL; + } + } + + /* + * Find out about any keys Pageant has (but if there's a + * public key configured, filter out all others). + */ + s->nkeys = 0; + s->agent_response = NULL; + s->pkblob_in_agent = NULL; + if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) { + + void *r; + + logevent("Pageant is running. Requesting keys."); + + /* Request the keys held by the agent. */ + PUT_32BIT(s->agent_request, 1); + s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; + if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen, + ssh_agent_callback, ssh)) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for agent response")); + crStopV; + } + } while (pktin || inlen > 0); + r = ssh->agent_response; + s->agent_responselen = ssh->agent_response_len; + } + s->agent_response = (unsigned char *) r; + if (s->agent_response && s->agent_responselen >= 5 && + s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { + int keyi; + unsigned char *p; + p = s->agent_response + 5; + s->nkeys = toint(GET_32BIT(p)); + + /* + * Vet the Pageant response to ensure that the key + * count and blob lengths make sense. + */ + if (s->nkeys < 0) { + logeventf(ssh, "Pageant response contained a negative" + " key count %d", s->nkeys); + s->nkeys = 0; + goto done_agent_query; + } else { + unsigned char *q = p + 4; + int lenleft = s->agent_responselen - 5 - 4; + + for (keyi = 0; keyi < s->nkeys; keyi++) { + int bloblen, commentlen; + if (lenleft < 4) { + logeventf(ssh, "Pageant response was truncated"); + s->nkeys = 0; + goto done_agent_query; + } + bloblen = toint(GET_32BIT(q)); + if (bloblen < 0 || bloblen > lenleft) { + logeventf(ssh, "Pageant response was truncated"); + s->nkeys = 0; + goto done_agent_query; + } + lenleft -= 4 + bloblen; + q += 4 + bloblen; + commentlen = toint(GET_32BIT(q)); + if (commentlen < 0 || commentlen > lenleft) { + logeventf(ssh, "Pageant response was truncated"); + s->nkeys = 0; + goto done_agent_query; + } + lenleft -= 4 + commentlen; + q += 4 + commentlen; + } + } + + p += 4; + logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); + if (s->publickey_blob) { + /* See if configured key is in agent. */ + for (keyi = 0; keyi < s->nkeys; keyi++) { + s->pklen = toint(GET_32BIT(p)); + if (s->pklen == s->publickey_bloblen && + !memcmp(p+4, s->publickey_blob, + s->publickey_bloblen)) { + logeventf(ssh, "Pageant key #%d matches " + "configured key file", keyi); + s->keyi = keyi; + s->pkblob_in_agent = p; + break; + } + p += 4 + s->pklen; + p += toint(GET_32BIT(p)) + 4; /* comment */ + } + if (!s->pkblob_in_agent) { + logevent("Configured key file not in Pageant"); + s->nkeys = 0; + } + } + } else { + logevent("Failed to get reply from Pageant"); + } + done_agent_query:; + } + } /* @@ -4511,50 +8032,45 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) * the username they will want to be able to get back and * retype it! */ - s->username[0] = '\0'; s->got_username = FALSE; - do { + while (!s->we_are_in) { /* * Get a username. */ - if (s->got_username && !ssh->cfg.change_username) { + if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) { /* * We got a username last time round this loop, and * with change_username turned off we don't try to get * it again. */ - } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) { - if (ssh_get_line && !ssh_getline_pw_only) { - if (!ssh_get_line("login as: ", - s->username, sizeof(s->username), FALSE)) { - /* - * get_line failed to get a username. - * Terminate. - */ - logevent("No username provided. Abandoning session."); - ssh_closing((Plug)ssh, NULL, 0, 0); - crStopV; - } - } else { - int ret; /* need not be saved across crReturn */ - c_write_str(ssh, "login as: "); + } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) { + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH login name"); + add_prompt(s->cur_prompt, dupstr("login as: "), TRUE); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { ssh->send_ok = 1; - setup_userpass_input(ssh, s->username, sizeof(s->username), 1); - do { - crWaitUntilV(!ispkt); - ret = process_userpass_input(ssh, in, inlen); - } while (ret == 0); - if (ret < 0) - cleanup_exit(0); - c_write_str(ssh, "\r\n"); + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * get_userpass_input() failed to get a username. + * Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); + crStopV; } - s->username[strcspn(s->username, "\n\r")] = '\0'; + ssh->username = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); } else { char *stuff; - strncpy(s->username, ssh->cfg.username, sizeof(s->username)); - s->username[sizeof(s->username)-1] = '\0'; if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { - stuff = dupprintf("Using username \"%s\".\r\n", s->username); + stuff = dupprintf("Using username \"%s\".\r\n", ssh->username); c_write_str(ssh, stuff); sfree(stuff); } @@ -4566,55 +8082,48 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) * just in case it succeeds, and (b) so that we know what * authentication methods we can usefully try next. */ - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; + ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; - ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(ssh, s->username); - ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */ - ssh2_pkt_addstring(ssh, "none"); /* method */ - ssh2_pkt_send(ssh); + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */ + ssh2_pkt_addstring(s->pktout, "none"); /* method */ + ssh2_pkt_send(ssh, s->pktout); s->type = AUTH_TYPE_NONE; s->gotit = FALSE; s->we_are_in = FALSE; s->tried_pubkey_config = FALSE; - s->tried_agent = FALSE; - s->tried_keyb_inter = FALSE; - s->kbd_inter_running = FALSE; - /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */ - if (!filename_is_null(ssh->cfg.keyfile)) { - int keytype; - logeventf(ssh, "Reading private key file \"%.150s\"", - filename_to_str(&ssh->cfg.keyfile)); - keytype = key_type(&ssh->cfg.keyfile); - if (keytype == SSH_KEYTYPE_SSH2) { - s->publickey_blob = - ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL, - &s->publickey_bloblen, NULL); + s->kbd_inter_refused = FALSE; + + /* Reset agent request state. */ + s->done_agent = FALSE; + if (s->agent_response) { + if (s->pkblob_in_agent) { + s->agentp = s->pkblob_in_agent; } else { - char *msgbuf; - logeventf(ssh, "Unable to use this key file (%s)", - key_type_to_str(keytype)); - msgbuf = dupprintf("Unable to use key file \"%.150s\"" - " (%s)\r\n", - filename_to_str(&ssh->cfg.keyfile), - key_type_to_str(keytype)); - c_write_str(ssh, msgbuf); - sfree(msgbuf); - s->publickey_blob = NULL; + s->agentp = s->agent_response + 5 + 4; + s->keyi = 0; } - } else - s->publickey_blob = NULL; + } while (1) { + char *methods = NULL; + int methlen = 0; + /* * Wait for the result of the last authentication request. */ if (!s->gotit) - crWaitUntilV(ispkt); - while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) { - char *banner; - int size; + crWaitUntilV(pktin); + /* + * Now is a convenient point to spew any banner material + * that we've accumulated. (This should ensure that when + * we exit the auth loop, we haven't any left to deal + * with.) + */ + { + int size = bufchain_size(&ssh->banner); /* * Don't show the banner if we're operating in * non-verbose non-interactive mode. (It's probably @@ -4623,33 +8132,23 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) * the banner will screw up processing on the * output of (say) plink.) */ - if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) { - ssh2_pkt_getstring(ssh, &banner, &size); - if (banner) - c_write_untrusted(ssh, banner, size); + if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) { + char *banner = snewn(size, char); + bufchain_fetch(&ssh->banner, banner, size); + c_write_untrusted(ssh, banner, size); + sfree(banner); } - crWaitUntilV(ispkt); + bufchain_clear(&ssh->banner); } - if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { + if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) { logevent("Access granted"); - s->we_are_in = TRUE; + s->we_are_in = s->userauth_success = TRUE; break; } - if (s->kbd_inter_running && - ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) { - /* - * This is either a further set-of-prompts packet - * in keyboard-interactive authentication, or it's - * the same one and we came back here with `gotit' - * set. In the former case, we must reset the - * curr_prompt variable. - */ - if (!s->gotit) - s->curr_prompt = 0; - } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) { - bombout(("Strange packet received during authentication: type %d", - ssh->pktin.type)); + if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) { + bombout(("Strange packet received during authentication: " + "type %d", pktin->type)); crStopV; } @@ -4660,32 +8159,31 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) * we can look at the string in it and know what we can * helpfully try next. */ - if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) { - char *methods; - int methlen; - ssh2_pkt_getstring(ssh, &methods, &methlen); - s->kbd_inter_running = FALSE; - if (!ssh2_pkt_getbool(ssh)) { + if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) { + ssh_pkt_getstring(pktin, &methods, &methlen); + if (!ssh2_pkt_getbool(pktin)) { /* * We have received an unequivocal Access * Denied. This can translate to a variety of - * messages: - * - * - if we'd just tried "none" authentication, - * it's not worth printing anything at all - * - * - if we'd just tried a public key _offer_, - * the message should be "Server refused our - * key" (or no message at all if the key - * came from Pageant) - * - * - if we'd just tried anything else, the - * message really should be "Access denied". - * + * messages, or no message at all. + * + * For forms of authentication which are attempted + * implicitly, by which I mean without printing + * anything in the window indicating that we're + * trying them, we should never print 'Access + * denied'. + * + * If we do print a message saying that we're + * attempting some kind of authentication, it's OK + * to print a followup message saying it failed - + * but the message may sometimes be more specific + * than simply 'Access denied'. + * * Additionally, if we'd just tried password * authentication, we should break out of this * whole loop so as to go back to the username - * prompt. + * prompt (iff we're configured to allow + * username change attempts). */ if (s->type == AUTH_TYPE_NONE) { /* do nothing */ @@ -4693,13 +8191,33 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) c_write_str(ssh, "Server refused our key\r\n"); - logevent("Server refused public key"); + logevent("Server refused our key"); + } else if (s->type == AUTH_TYPE_PUBLICKEY) { + /* This _shouldn't_ happen except by a + * protocol bug causing client and server to + * disagree on what is a correct signature. */ + c_write_str(ssh, "Server refused public-key signature" + " despite accepting key!\r\n"); + logevent("Server refused public-key signature" + " despite accepting key!"); } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) { - /* server declined keyboard-interactive; ignore */ - } else { + /* quiet, so no c_write */ + logevent("Server refused keyboard-interactive authentication"); + } else if (s->type==AUTH_TYPE_GSSAPI) { + /* always quiet, so no c_write */ + /* also, the code down in the GSSAPI block has + * already logged this in the Event Log */ + } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) { + logevent("Keyboard-interactive authentication failed"); + c_write_str(ssh, "Access denied\r\n"); + } else { + assert(s->type == AUTH_TYPE_PASSWORD); + logevent("Password authentication failed"); c_write_str(ssh, "Access denied\r\n"); - logevent("Access denied"); - if (s->type == AUTH_TYPE_PASSWORD) { + + if (conf_get_int(ssh->conf, CONF_change_username)) { + /* XXX perhaps we should allow + * keyboard-interactive to do this too? */ s->we_are_in = FALSE; break; } @@ -4713,954 +8231,1155 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) in_commasep_string("publickey", methods, methlen); s->can_passwd = in_commasep_string("password", methods, methlen); - s->can_keyb_inter = ssh->cfg.try_ki_auth && + s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) && in_commasep_string("keyboard-interactive", methods, methlen); +#ifndef NO_GSSAPI + if (!ssh->gsslibs) + ssh->gsslibs = ssh_gss_setup(ssh->conf); + s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) && + in_commasep_string("gssapi-with-mic", methods, methlen) && + ssh->gsslibs->nlibraries > 0; +#endif } - s->method = 0; - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; + ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; - /* - * Most password/passphrase prompts will be - * non-echoing, so we set this to 0 by default. - * Exception is that some keyboard-interactive prompts - * can be echoing, in which case we'll set this to 1. - */ - s->echo = 0; + if (s->can_pubkey && !s->done_agent && s->nkeys) { - if (!s->method && s->can_pubkey && - agent_exists() && !s->tried_agent) { /* - * Attempt public-key authentication using Pageant. + * Attempt public-key authentication using a key from Pageant. */ - void *r; - s->authed = FALSE; - - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; - ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; - - s->tried_agent = TRUE; - - logevent("Pageant is running. Requesting keys."); - - /* Request the keys held by the agent. */ - PUT_32BIT(s->request, 1); - s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; - if (!agent_query(s->request, 5, &r, &s->responselen, - ssh_agent_callback, ssh)) { - do { - crReturnV; - if (ispkt) { - bombout(("Unexpected data from server while" - " waiting for agent response")); + + ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY; + + logeventf(ssh, "Trying Pageant key #%d", s->keyi); + + /* Unpack key from agent response */ + s->pklen = toint(GET_32BIT(s->agentp)); + s->agentp += 4; + s->pkblob = (char *)s->agentp; + s->agentp += s->pklen; + s->alglen = toint(GET_32BIT(s->pkblob)); + s->alg = s->pkblob + 4; + s->commentlen = toint(GET_32BIT(s->agentp)); + s->agentp += 4; + s->commentp = (char *)s->agentp; + s->agentp += s->commentlen; + /* s->agentp now points at next key, if any */ + + /* See if server will accept it */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); + /* method */ + ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */ + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); + ssh2_pkt_send(ssh, s->pktout); + s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET; + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { + + /* Offer of key refused. */ + s->gotit = TRUE; + + } else { + + void *vret; + + if (flags & FLAG_VERBOSE) { + c_write_str(ssh, "Authenticating with " + "public key \""); + c_write(ssh, s->commentp, s->commentlen); + c_write_str(ssh, "\" from agent\r\n"); + } + + /* + * Server is willing to accept the key. + * Construct a SIGN_REQUEST. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); + /* method */ + ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */ + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); + + /* Ask agent for signature. */ + s->siglen = s->pktout->length - 5 + 4 + + ssh->v2_session_id_len; + if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) + s->siglen -= 4; + s->len = 1; /* message type */ + s->len += 4 + s->pklen; /* key blob */ + s->len += 4 + s->siglen; /* data to sign */ + s->len += 4; /* flags */ + s->agentreq = snewn(4 + s->len, char); + PUT_32BIT(s->agentreq, s->len); + s->q = s->agentreq + 4; + *s->q++ = SSH2_AGENTC_SIGN_REQUEST; + PUT_32BIT(s->q, s->pklen); + s->q += 4; + memcpy(s->q, s->pkblob, s->pklen); + s->q += s->pklen; + PUT_32BIT(s->q, s->siglen); + s->q += 4; + /* Now the data to be signed... */ + if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { + PUT_32BIT(s->q, ssh->v2_session_id_len); + s->q += 4; + } + memcpy(s->q, ssh->v2_session_id, + ssh->v2_session_id_len); + s->q += ssh->v2_session_id_len; + memcpy(s->q, s->pktout->data + 5, + s->pktout->length - 5); + s->q += s->pktout->length - 5; + /* And finally the (zero) flags word. */ + PUT_32BIT(s->q, 0); + if (!agent_query(s->agentreq, s->len + 4, + &vret, &s->retlen, + ssh_agent_callback, ssh)) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server" + " while waiting for agent" + " response")); + crStopV; + } + } while (pktin || inlen > 0); + vret = ssh->agent_response; + s->retlen = ssh->agent_response_len; + } + s->ret = vret; + sfree(s->agentreq); + if (s->ret) { + if (s->retlen >= 9 && + s->ret[4] == SSH2_AGENT_SIGN_RESPONSE && + GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) { + logevent("Sending Pageant's response"); + ssh2_add_sigblob(ssh, s->pktout, + s->pkblob, s->pklen, + s->ret + 9, + GET_32BIT(s->ret + 5)); + ssh2_pkt_send(ssh, s->pktout); + s->type = AUTH_TYPE_PUBLICKEY; + } else { + /* FIXME: less drastic response */ + bombout(("Pageant failed to answer challenge")); crStopV; } - } while (ispkt || inlen > 0); - r = ssh->agent_response; - s->responselen = ssh->agent_response_len; - } - s->response = (unsigned char *) r; - if (s->response && s->responselen >= 5 && - s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { - s->p = s->response + 5; - s->nkeys = GET_32BIT(s->p); - s->p += 4; - { - char buf[64]; - sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys); - logevent(buf); } - for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { - void *vret; + } - { - char buf[64]; - sprintf(buf, "Trying Pageant key #%d", s->keyi); - logevent(buf); - } - s->pklen = GET_32BIT(s->p); - s->p += 4; - if (s->publickey_blob && - s->pklen == s->publickey_bloblen && - !memcmp(s->p, s->publickey_blob, - s->publickey_bloblen)) { - logevent("This key matches configured key file"); - s->tried_pubkey_config = 1; - } - s->pkblob = (char *)s->p; - s->p += s->pklen; - s->alglen = GET_32BIT(s->pkblob); - s->alg = s->pkblob + 4; - s->commentlen = GET_32BIT(s->p); - s->p += 4; - s->commentp = (char *)s->p; - s->p += s->commentlen; - ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(ssh, s->username); - ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(ssh, "publickey"); /* method */ - ssh2_pkt_addbool(ssh, FALSE); /* no signature included */ - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, s->alg, s->alglen); - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen); - ssh2_pkt_send(ssh); - - crWaitUntilV(ispkt); - if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) { - logevent("Key refused"); - continue; - } + /* Do we have any keys left to try? */ + if (s->pkblob_in_agent) { + s->done_agent = TRUE; + s->tried_pubkey_config = TRUE; + } else { + s->keyi++; + if (s->keyi >= s->nkeys) + s->done_agent = TRUE; + } - if (flags & FLAG_VERBOSE) { - c_write_str(ssh, "Authenticating with " - "public key \""); - c_write(ssh, s->commentp, s->commentlen); - c_write_str(ssh, "\" from agent\r\n"); - } + } else if (s->can_pubkey && s->publickey_blob && + !s->tried_pubkey_config) { + + struct ssh2_userkey *key; /* not live over crReturn */ + char *passphrase; /* not live over crReturn */ + + ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY; + + s->tried_pubkey_config = TRUE; + + /* + * Try the public key supplied in the configuration. + * + * First, offer the public blob to see if the server is + * willing to accept it. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); /* method */ + ssh2_pkt_addbool(s->pktout, FALSE); + /* no signature included */ + ssh2_pkt_addstring(s->pktout, s->publickey_algorithm); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, + (char *)s->publickey_blob, + s->publickey_bloblen); + ssh2_pkt_send(ssh, s->pktout); + logevent("Offered public key"); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { + /* Key refused. Give up. */ + s->gotit = TRUE; /* reconsider message next loop */ + s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; + continue; /* process this new message */ + } + logevent("Offer of public key accepted"); + /* + * Actually attempt a serious authentication using + * the key. + */ + if (flags & FLAG_VERBOSE) { + c_write_str(ssh, "Authenticating with public key \""); + c_write_str(ssh, s->publickey_comment); + c_write_str(ssh, "\"\r\n"); + } + key = NULL; + while (!key) { + const char *error; /* not live over crReturn */ + if (s->publickey_encrypted) { /* - * Server is willing to accept the key. - * Construct a SIGN_REQUEST. + * Get a passphrase from the user. */ - ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(ssh, s->username); - ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(ssh, "publickey"); /* method */ - ssh2_pkt_addbool(ssh, TRUE); - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, s->alg, s->alglen); - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen); - - s->siglen = ssh->pktout.length - 5 + 4 + 20; - if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) - s->siglen -= 4; - s->len = 1; /* message type */ - s->len += 4 + s->pklen; /* key blob */ - s->len += 4 + s->siglen; /* data to sign */ - s->len += 4; /* flags */ - s->agentreq = snewn(4 + s->len, char); - PUT_32BIT(s->agentreq, s->len); - s->q = s->agentreq + 4; - *s->q++ = SSH2_AGENTC_SIGN_REQUEST; - PUT_32BIT(s->q, s->pklen); - s->q += 4; - memcpy(s->q, s->pkblob, s->pklen); - s->q += s->pklen; - PUT_32BIT(s->q, s->siglen); - s->q += 4; - /* Now the data to be signed... */ - if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { - PUT_32BIT(s->q, 20); - s->q += 4; - } - memcpy(s->q, ssh->v2_session_id, 20); - s->q += 20; - memcpy(s->q, ssh->pktout.data + 5, - ssh->pktout.length - 5); - s->q += ssh->pktout.length - 5; - /* And finally the (zero) flags word. */ - PUT_32BIT(s->q, 0); - if (!agent_query(s->agentreq, s->len + 4, - &vret, &s->retlen, - ssh_agent_callback, ssh)) { - do { - crReturnV; - if (ispkt) { - bombout(("Unexpected data from server" - " while waiting for agent" - " response")); - crStopV; - } - } while (ispkt || inlen > 0); - vret = ssh->agent_response; - s->retlen = ssh->agent_response_len; + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = FALSE; + s->cur_prompt->name = dupstr("SSH key passphrase"); + add_prompt(s->cur_prompt, + dupprintf("Passphrase for key \"%.100s\": ", + s->publickey_comment), + FALSE); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, + in, inlen); + ssh->send_ok = 0; } - s->ret = vret; - sfree(s->agentreq); - if (s->ret) { - if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) { - logevent("Sending Pageant's response"); - ssh2_add_sigblob(ssh, s->pkblob, s->pklen, - s->ret + 9, - GET_32BIT(s->ret + 5)); - ssh2_pkt_send(ssh); - s->authed = TRUE; - break; - } else { - logevent - ("Pageant failed to answer challenge"); - sfree(s->ret); + if (!ret) { + /* Failed to get a passphrase. Terminate. */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, + "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + passphrase = + dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + } else { + passphrase = NULL; /* no passphrase needed */ + } + + /* + * Try decrypting the key. + */ + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + key = ssh2_load_userkey(s->keyfile, passphrase, &error); + if (passphrase) { + /* burn the evidence */ + smemclr(passphrase, strlen(passphrase)); + sfree(passphrase); + } + if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { + if (passphrase && + (key == SSH2_WRONG_PASSPHRASE)) { + c_write_str(ssh, "Wrong passphrase\r\n"); + key = NULL; + /* and loop again */ + } else { + c_write_str(ssh, "Unable to load private key ("); + c_write_str(ssh, error); + c_write_str(ssh, ")\r\n"); + key = NULL; + break; /* try something else */ + } + } + } + + if (key) { + unsigned char *pkblob, *sigblob, *sigdata; + int pkblob_len, sigblob_len, sigdata_len; + int p; + + /* + * We have loaded the private key and the server + * has announced that it's willing to accept it. + * Hallelujah. Generate a signature and send it. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); + /* method */ + ssh2_pkt_addbool(s->pktout, TRUE); + /* signature follows */ + ssh2_pkt_addstring(s->pktout, key->alg->name); + pkblob = key->alg->public_blob(key->data, + &pkblob_len); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, + pkblob_len); + + /* + * The data to be signed is: + * + * string session-id + * + * followed by everything so far placed in the + * outgoing packet. + */ + sigdata_len = s->pktout->length - 5 + 4 + + ssh->v2_session_id_len; + if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) + sigdata_len -= 4; + sigdata = snewn(sigdata_len, unsigned char); + p = 0; + if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { + PUT_32BIT(sigdata+p, ssh->v2_session_id_len); + p += 4; + } + memcpy(sigdata+p, ssh->v2_session_id, + ssh->v2_session_id_len); + p += ssh->v2_session_id_len; + memcpy(sigdata+p, s->pktout->data + 5, + s->pktout->length - 5); + p += s->pktout->length - 5; + assert(p == sigdata_len); + sigblob = key->alg->sign(key->data, (char *)sigdata, + sigdata_len, &sigblob_len); + ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len, + sigblob, sigblob_len); + sfree(pkblob); + sfree(sigblob); + sfree(sigdata); + + ssh2_pkt_send(ssh, s->pktout); + logevent("Sent public key signature"); + s->type = AUTH_TYPE_PUBLICKEY; + key->alg->freekey(key->data); + } + +#ifndef NO_GSSAPI + } else if (s->can_gssapi && !s->tried_gssapi) { + + /* GSSAPI Authentication */ + + int micoffset, len; + char *data; + Ssh_gss_buf mic; + s->type = AUTH_TYPE_GSSAPI; + s->tried_gssapi = TRUE; + s->gotit = TRUE; + ssh->pkt_actx = SSH2_PKTCTX_GSSAPI; + + /* + * Pick the highest GSS library on the preference + * list. + */ + { + int i, j; + s->gsslib = NULL; + for (i = 0; i < ngsslibs; i++) { + int want_id = conf_get_int_int(ssh->conf, + CONF_ssh_gsslist, i); + for (j = 0; j < ssh->gsslibs->nlibraries; j++) + if (ssh->gsslibs->libraries[j].id == want_id) { + s->gsslib = &ssh->gsslibs->libraries[j]; + goto got_gsslib; /* double break */ } + } + got_gsslib: + /* + * We always expect to have found something in + * the above loop: we only came here if there + * was at least one viable GSS library, and the + * preference list should always mention + * everything and only change the order. + */ + assert(s->gsslib); + } + + if (s->gsslib->gsslogmsg) + logevent(s->gsslib->gsslogmsg); + + /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + ssh2_pkt_addstring(s->pktout, "gssapi-with-mic"); + logevent("Attempting GSSAPI authentication"); + + /* add mechanism info */ + s->gsslib->indicate_mech(s->gsslib, &s->gss_buf); + + /* number of GSSAPI mechanisms */ + ssh2_pkt_adduint32(s->pktout,1); + + /* length of OID + 2 */ + ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2); + ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE); + + /* length of OID */ + ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length); + + ssh_pkt_adddata(s->pktout, s->gss_buf.value, + s->gss_buf.length); + ssh2_pkt_send(ssh, s->pktout); + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) { + logevent("GSSAPI authentication request refused"); + continue; + } + + /* check returned packet ... */ + + ssh_pkt_getstring(pktin, &data, &len); + s->gss_rcvtok.value = data; + s->gss_rcvtok.length = len; + if (s->gss_rcvtok.length != s->gss_buf.length + 2 || + ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE || + ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length || + memcmp((char *)s->gss_rcvtok.value + 2, + s->gss_buf.value,s->gss_buf.length) ) { + logevent("GSSAPI authentication - wrong response from server"); + continue; + } + + /* now start running */ + s->gss_stat = s->gsslib->import_name(s->gsslib, + ssh->fullhostname, + &s->gss_srv_name); + if (s->gss_stat != SSH_GSS_OK) { + if (s->gss_stat == SSH_GSS_BAD_HOST_NAME) + logevent("GSSAPI import name failed - Bad service name"); + else + logevent("GSSAPI import name failed"); + continue; + } + + /* fetch TGT into GSS engine */ + s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx); + + if (s->gss_stat != SSH_GSS_OK) { + logevent("GSSAPI authentication failed to get credentials"); + s->gsslib->release_name(s->gsslib, &s->gss_srv_name); + continue; + } + + /* initial tokens are empty */ + SSH_GSS_CLEAR_BUF(&s->gss_rcvtok); + SSH_GSS_CLEAR_BUF(&s->gss_sndtok); + + /* now enter the loop */ + do { + s->gss_stat = s->gsslib->init_sec_context + (s->gsslib, + &s->gss_ctx, + s->gss_srv_name, + conf_get_int(ssh->conf, CONF_gssapifwd), + &s->gss_rcvtok, + &s->gss_sndtok); + + if (s->gss_stat!=SSH_GSS_S_COMPLETE && + s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) { + logevent("GSSAPI authentication initialisation failed"); + + if (s->gsslib->display_status(s->gsslib, s->gss_ctx, + &s->gss_buf) == SSH_GSS_OK) { + logevent(s->gss_buf.value); + sfree(s->gss_buf.value); } + + break; } - if (s->authed) - continue; + logevent("GSSAPI authentication initialised"); + + /* Client and server now exchange tokens until GSSAPI + * no longer says CONTINUE_NEEDED */ + + if (s->gss_sndtok.length != 0) { + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); + ssh_pkt_addstring_start(s->pktout); + ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length); + ssh2_pkt_send(ssh, s->pktout); + s->gsslib->free_tok(s->gsslib, &s->gss_sndtok); + } + + if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) { + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) { + logevent("GSSAPI authentication - bad server response"); + s->gss_stat = SSH_GSS_FAILURE; + break; + } + ssh_pkt_getstring(pktin, &data, &len); + s->gss_rcvtok.value = data; + s->gss_rcvtok.length = len; + } + } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED); + + if (s->gss_stat != SSH_GSS_OK) { + s->gsslib->release_name(s->gsslib, &s->gss_srv_name); + s->gsslib->release_cred(s->gsslib, &s->gss_ctx); + continue; } - } + logevent("GSSAPI authentication loop finished OK"); - if (!s->method && s->can_pubkey && s->publickey_blob - && !s->tried_pubkey_config) { - unsigned char *pub_blob; - char *algorithm, *comment; - int pub_blob_len; + /* Now send the MIC */ - s->tried_pubkey_config = TRUE; + s->pktout = ssh2_pkt_init(0); + micoffset = s->pktout->length; + ssh_pkt_addstring_start(s->pktout); + ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len); + ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST); + ssh_pkt_addstring(s->pktout, ssh->username); + ssh_pkt_addstring(s->pktout, "ssh-connection"); + ssh_pkt_addstring(s->pktout, "gssapi-with-mic"); + + s->gss_buf.value = (char *)s->pktout->data + micoffset; + s->gss_buf.length = s->pktout->length - micoffset; - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; - ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; + s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic); + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC); + ssh_pkt_addstring_start(s->pktout); + ssh_pkt_addstring_data(s->pktout, mic.value, mic.length); + ssh2_pkt_send(ssh, s->pktout); + s->gsslib->free_mic(s->gsslib, &mic); + + s->gotit = FALSE; + + s->gsslib->release_name(s->gsslib, &s->gss_srv_name); + s->gsslib->release_cred(s->gsslib, &s->gss_ctx); + continue; +#endif + } else if (s->can_keyb_inter && !s->kbd_inter_refused) { /* - * Try the public key supplied in the configuration. - * - * First, offer the public blob to see if the server is - * willing to accept it. + * Keyboard-interactive authentication. */ - pub_blob = - (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile, - &algorithm, - &pub_blob_len, - NULL); - if (pub_blob) { - ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(ssh, s->username); - ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(ssh, "publickey"); /* method */ - ssh2_pkt_addbool(ssh, FALSE); /* no signature included */ - ssh2_pkt_addstring(ssh, algorithm); - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, (char *)pub_blob, - pub_blob_len); - ssh2_pkt_send(ssh); - logevent("Offered public key"); /* FIXME */ - - crWaitUntilV(ispkt); - if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) { - s->gotit = TRUE; - s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; - continue; /* key refused; give up on it */ - } - - logevent("Offer of public key accepted"); - /* - * Actually attempt a serious authentication using - * the key. - */ - if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) { - sprintf(s->pwprompt, - "Passphrase for key \"%.100s\": ", - comment); - s->need_pw = TRUE; - } else { - s->need_pw = FALSE; - } - c_write_str(ssh, "Authenticating with public key \""); - c_write_str(ssh, comment); - c_write_str(ssh, "\"\r\n"); - s->method = AUTH_PUBLICKEY_FILE; - } - } - if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) { - s->method = AUTH_KEYBOARD_INTERACTIVE; s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; - s->tried_keyb_inter = TRUE; - - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; - ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER; - - ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(ssh, s->username); - ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */ - ssh2_pkt_addstring(ssh, ""); /* lang */ - ssh2_pkt_addstring(ssh, ""); - ssh2_pkt_send(ssh); - - crWaitUntilV(ispkt); - if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) { - if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) - s->gotit = TRUE; - logevent("Keyboard-interactive authentication refused"); + + ssh->pkt_actx = SSH2_PKTCTX_KBDINTER; + + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); + /* method */ + ssh2_pkt_addstring(s->pktout, ""); /* lang */ + ssh2_pkt_addstring(s->pktout, ""); /* submethods */ + ssh2_pkt_send(ssh, s->pktout); + + logevent("Attempting keyboard-interactive authentication"); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) { + /* Server is not willing to do keyboard-interactive + * at all (or, bizarrely but legally, accepts the + * user without actually issuing any prompts). + * Give up on it entirely. */ + s->gotit = TRUE; s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; + s->kbd_inter_refused = TRUE; /* don't try it again */ continue; } - s->kbd_inter_running = TRUE; - s->curr_prompt = 0; - } - - if (s->kbd_inter_running) { - s->method = AUTH_KEYBOARD_INTERACTIVE; - s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; - s->tried_keyb_inter = TRUE; + /* + * Loop while the server continues to send INFO_REQUESTs. + */ + while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) { - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; - ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER; + char *name, *inst, *lang; + int name_len, inst_len, lang_len; + int i; - if (s->curr_prompt == 0) { /* * We've got a fresh USERAUTH_INFO_REQUEST. - * Display header data, and start going through - * the prompts. + * Get the preamble and start building a prompt. */ - char *name, *inst, *lang; - int name_len, inst_len, lang_len; + ssh_pkt_getstring(pktin, &name, &name_len); + ssh_pkt_getstring(pktin, &inst, &inst_len); + ssh_pkt_getstring(pktin, &lang, &lang_len); + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; - ssh2_pkt_getstring(ssh, &name, &name_len); - ssh2_pkt_getstring(ssh, &inst, &inst_len); - ssh2_pkt_getstring(ssh, &lang, &lang_len); - if (name_len > 0) { - c_write_untrusted(ssh, name, name_len); - c_write_str(ssh, "\r\n"); - } - if (inst_len > 0) { - c_write_untrusted(ssh, inst, inst_len); - c_write_str(ssh, "\r\n"); + /* + * Get any prompt(s) from the packet. + */ + s->num_prompts = ssh_pkt_getuint32(pktin); + for (i = 0; i < s->num_prompts; i++) { + char *prompt; + int prompt_len; + int echo; + static char noprompt[] = + ": "; + + ssh_pkt_getstring(pktin, &prompt, &prompt_len); + echo = ssh2_pkt_getbool(pktin); + if (!prompt_len) { + prompt = noprompt; + prompt_len = lenof(noprompt)-1; + } + add_prompt(s->cur_prompt, + dupprintf("%.*s", prompt_len, prompt), + echo); } - s->num_prompts = ssh2_pkt_getuint32(ssh); - } - /* - * If there are prompts remaining in the packet, - * display one and get a response. - */ - if (s->curr_prompt < s->num_prompts) { - char *prompt; - int prompt_len; - - ssh2_pkt_getstring(ssh, &prompt, &prompt_len); - if (prompt_len > 0) { - strncpy(s->pwprompt, prompt, sizeof(s->pwprompt)); - s->pwprompt[prompt_len < sizeof(s->pwprompt) ? - prompt_len : sizeof(s->pwprompt)-1] = '\0'; + if (name_len) { + /* FIXME: better prefix to distinguish from + * local prompts? */ + s->cur_prompt->name = + dupprintf("SSH server: %.*s", name_len, name); + s->cur_prompt->name_reqd = TRUE; } else { - strcpy(s->pwprompt, - ": "); + s->cur_prompt->name = + dupstr("SSH server authentication"); + s->cur_prompt->name_reqd = FALSE; + } + /* We add a prefix to try to make it clear that a prompt + * has come from the server. + * FIXME: ugly to print "Using..." in prompt _every_ + * time round. Can this be done more subtly? */ + /* Special case: for reasons best known to themselves, + * some servers send k-i requests with no prompts and + * nothing to display. Keep quiet in this case. */ + if (s->num_prompts || name_len || inst_len) { + s->cur_prompt->instruction = + dupprintf("Using keyboard-interactive authentication.%s%.*s", + inst_len ? "\n" : "", inst_len, inst); + s->cur_prompt->instr_reqd = TRUE; + } else { + s->cur_prompt->instr_reqd = FALSE; } - s->echo = ssh2_pkt_getbool(ssh); - s->need_pw = TRUE; - } else - s->need_pw = FALSE; - } - if (!s->method && s->can_passwd) { - s->method = AUTH_PASSWORD; - ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; - ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD; - sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username, - ssh->savedhost); - s->need_pw = TRUE; - } + /* + * Display any instructions, and get the user's + * response(s). + */ + { + int ret; /* not live over crReturn */ + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get responses. Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + } - if (s->need_pw) { - if (ssh_get_line) { - if (!ssh_get_line(s->pwprompt, s->password, - sizeof(s->password), TRUE)) { - /* - * get_line failed to get a password (for - * example because one was supplied on the - * command line which has already failed to - * work). Terminate. - */ - ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(ssh, "No more passwords available" - " to try"); - ssh2_pkt_addstring(ssh, "en"); /* language tag */ - ssh2_pkt_send(ssh); - logevent("Unable to authenticate"); - connection_fatal(ssh->frontend, - "Unable to authenticate"); - ssh_closing((Plug)ssh, NULL, 0, 0); - crStopV; + /* + * Send the response(s) to the server. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); + ssh2_pkt_adduint32(s->pktout, s->num_prompts); + for (i=0; i < s->num_prompts; i++) { + dont_log_password(ssh, s->pktout, PKTLOG_BLANK); + ssh2_pkt_addstring(s->pktout, + s->cur_prompt->prompts[i]->result); + end_log_omission(ssh, s->pktout); } - } else { - int ret; /* need not be saved across crReturn */ - c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt)); - ssh->send_ok = 1; + ssh2_pkt_send_with_padding(ssh, s->pktout, 256); + + /* + * Free the prompts structure from this iteration. + * If there's another, a new one will be allocated + * when we return to the top of this while loop. + */ + free_prompts(s->cur_prompt); + + /* + * Get the next packet in case it's another + * INFO_REQUEST. + */ + crWaitUntilV(pktin); - setup_userpass_input(ssh, s->password, - sizeof(s->password), s->echo); - do { - crWaitUntilV(!ispkt); - ret = process_userpass_input(ssh, in, inlen); - } while (ret == 0); - if (ret < 0) - cleanup_exit(0); - c_write_str(ssh, "\r\n"); } - } - if (s->method == AUTH_PUBLICKEY_FILE) { /* - * We have our passphrase. Now try the actual authentication. + * We should have SUCCESS or FAILURE now. */ - struct ssh2_userkey *key; - const char *error = NULL; - - key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password, - &error); - if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { - if (key == SSH2_WRONG_PASSPHRASE) { - c_write_str(ssh, "Wrong passphrase\r\n"); - s->tried_pubkey_config = FALSE; - } else { - c_write_str(ssh, "Unable to load private key ("); - c_write_str(ssh, error); - c_write_str(ssh, ")\r\n"); - s->tried_pubkey_config = TRUE; - } - /* Send a spurious AUTH_NONE to return to the top. */ - ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(ssh, s->username); - ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(ssh, "none"); /* method */ - ssh2_pkt_send(ssh); - s->type = AUTH_TYPE_NONE; - } else { - unsigned char *pkblob, *sigblob, *sigdata; - int pkblob_len, sigblob_len, sigdata_len; - int p; + s->gotit = TRUE; - /* - * We have loaded the private key and the server - * has announced that it's willing to accept it. - * Hallelujah. Generate a signature and send it. - */ - ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(ssh, s->username); - ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(ssh, "publickey"); /* method */ - ssh2_pkt_addbool(ssh, TRUE); - ssh2_pkt_addstring(ssh, key->alg->name); - pkblob = key->alg->public_blob(key->data, &pkblob_len); - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len); + } else if (s->can_passwd) { + + /* + * Plain old password authentication. + */ + int ret; /* not live over crReturn */ + int changereq_first_time; /* not live over crReturn */ + + ssh->pkt_actx = SSH2_PKTCTX_PASSWORD; + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH password"); + add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ", + ssh->username, + ssh->savedhost), + FALSE); + + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { /* - * The data to be signed is: - * - * string session-id - * - * followed by everything so far placed in the - * outgoing packet. + * Failed to get responses. Terminate. */ - sigdata_len = ssh->pktout.length - 5 + 4 + 20; - if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) - sigdata_len -= 4; - sigdata = snewn(sigdata_len, unsigned char); - p = 0; - if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { - PUT_32BIT(sigdata+p, 20); - p += 4; - } - memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20; - memcpy(sigdata+p, ssh->pktout.data + 5, - ssh->pktout.length - 5); - p += ssh->pktout.length - 5; - assert(p == sigdata_len); - sigblob = key->alg->sign(key->data, (char *)sigdata, - sigdata_len, &sigblob_len); - ssh2_add_sigblob(ssh, pkblob, pkblob_len, - sigblob, sigblob_len); - sfree(pkblob); - sfree(sigblob); - sfree(sigdata); - - ssh2_pkt_send(ssh); - s->type = AUTH_TYPE_PUBLICKEY; + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; } - } else if (s->method == AUTH_PASSWORD) { /* - * We send the password packet lumped tightly together with - * an SSH_MSG_IGNORE packet. The IGNORE packet contains a - * string long enough to make the total length of the two - * packets constant. This should ensure that a passive - * listener doing traffic analyis can't work out the length - * of the password. + * Squirrel away the password. (We may need it later if + * asked to change it.) + */ + s->password = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + + /* + * Send the password packet. + * + * We pad out the password packet to 256 bytes to make + * it harder for an attacker to find the length of the + * user's password. * - * For this to work, we need an assumption about the - * maximum length of the password packet. I think 256 is - * pretty conservative. Anyone using a password longer than - * that probably doesn't have much to worry about from + * Anyone using a password longer than 256 bytes + * probably doesn't have much to worry about from * people who find out how long their password is! */ - ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(ssh, s->username); - ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ - ssh2_pkt_addstring(ssh, "password"); - ssh2_pkt_addbool(ssh, FALSE); - ssh2_pkt_addstring(ssh, s->password); - memset(s->password, 0, sizeof(s->password)); - ssh2_pkt_defer(ssh); + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "password"); + ssh2_pkt_addbool(s->pktout, FALSE); + dont_log_password(ssh, s->pktout, PKTLOG_BLANK); + ssh2_pkt_addstring(s->pktout, s->password); + end_log_omission(ssh, s->pktout); + ssh2_pkt_send_with_padding(ssh, s->pktout, 256); + logevent("Sent password"); + s->type = AUTH_TYPE_PASSWORD; + /* - * We'll include a string that's an exact multiple of the - * cipher block size. If the cipher is NULL for some - * reason, we don't do this trick at all because we gain - * nothing by it. + * Wait for next packet, in case it's a password change + * request. */ - if (ssh->cscipher) { - int stringlen, i; + crWaitUntilV(pktin); + changereq_first_time = TRUE; + + while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) { + + /* + * We're being asked for a new password + * (perhaps not for the first time). + * Loop until the server accepts it. + */ + + int got_new = FALSE; /* not live over crReturn */ + char *prompt; /* not live over crReturn */ + int prompt_len; /* not live over crReturn */ + + { + char *msg; + if (changereq_first_time) + msg = "Server requested password change"; + else + msg = "Server rejected new password"; + logevent(msg); + c_write_str(ssh, msg); + c_write_str(ssh, "\r\n"); + } + + ssh_pkt_getstring(pktin, &prompt, &prompt_len); + + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("New SSH password"); + s->cur_prompt->instruction = + dupprintf("%.*s", prompt_len, prompt); + s->cur_prompt->instr_reqd = TRUE; + /* + * There's no explicit requirement in the protocol + * for the "old" passwords in the original and + * password-change messages to be the same, and + * apparently some Cisco kit supports password change + * by the user entering a blank password originally + * and the real password subsequently, so, + * reluctantly, we prompt for the old password again. + * + * (On the other hand, some servers don't even bother + * to check this field.) + */ + add_prompt(s->cur_prompt, + dupstr("Current password (blank for previously entered password): "), + FALSE); + add_prompt(s->cur_prompt, dupstr("Enter new password: "), + FALSE); + add_prompt(s->cur_prompt, dupstr("Confirm new password: "), + FALSE); + + /* + * Loop until the user manages to enter the same + * password twice. + */ + while (!got_new) { + + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get responses. Terminate. + */ + /* burn the evidence */ + free_prompts(s->cur_prompt); + smemclr(s->password, strlen(s->password)); + sfree(s->password); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } - stringlen = (256 - ssh->deferred_len); - stringlen += ssh->cscipher->blksize - 1; - stringlen -= (stringlen % ssh->cscipher->blksize); - if (ssh->cscomp) { /* - * Temporarily disable actual compression, - * so we can guarantee to get this string - * exactly the length we want it. The - * compression-disabling routine should - * return an integer indicating how many - * bytes we should adjust our string length - * by. + * If the user specified a new original password + * (IYSWIM), overwrite any previously specified + * one. + * (A side effect is that the user doesn't have to + * re-enter it if they louse up the new password.) */ - stringlen -= - ssh->cscomp->disable_compression(ssh->cs_comp_ctx); - } - ssh2_pkt_init(ssh, SSH2_MSG_IGNORE); - ssh2_pkt_addstring_start(ssh); - for (i = 0; i < stringlen; i++) { - char c = (char) random_byte(); - ssh2_pkt_addstring_data(ssh, &c, 1); + if (s->cur_prompt->prompts[0]->result[0]) { + smemclr(s->password, strlen(s->password)); + /* burn the evidence */ + sfree(s->password); + s->password = + dupstr(s->cur_prompt->prompts[0]->result); + } + + /* + * Check the two new passwords match. + */ + got_new = (strcmp(s->cur_prompt->prompts[1]->result, + s->cur_prompt->prompts[2]->result) + == 0); + if (!got_new) + /* They don't. Silly user. */ + c_write_str(ssh, "Passwords do not match\r\n"); + } - ssh2_pkt_defer(ssh); - } - ssh_pkt_defersend(ssh); - logevent("Sent password"); - s->type = AUTH_TYPE_PASSWORD; - } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) { - if (s->curr_prompt == 0) { - ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE); - ssh2_pkt_adduint32(ssh, s->num_prompts); - } - if (s->need_pw) { /* only add pw if we just got one! */ - ssh2_pkt_addstring(ssh, s->password); - memset(s->password, 0, sizeof(s->password)); - s->curr_prompt++; - } - if (s->curr_prompt >= s->num_prompts) { - ssh2_pkt_send(ssh); - } else { + /* - * If there are prompts remaining, we set - * `gotit' so that we won't attempt to get - * another packet. Then we go back round the - * loop and will end up retrieving another - * prompt out of the existing packet. Funky or - * what? + * Send the new password (along with the old one). + * (see above for padding rationale) */ - s->gotit = TRUE; + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "password"); + ssh2_pkt_addbool(s->pktout, TRUE); + dont_log_password(ssh, s->pktout, PKTLOG_BLANK); + ssh2_pkt_addstring(s->pktout, s->password); + ssh2_pkt_addstring(s->pktout, + s->cur_prompt->prompts[1]->result); + free_prompts(s->cur_prompt); + end_log_omission(ssh, s->pktout); + ssh2_pkt_send_with_padding(ssh, s->pktout, 256); + logevent("Sent new password"); + + /* + * Now see what the server has to say about it. + * (If it's CHANGEREQ again, it's not happy with the + * new password.) + */ + crWaitUntilV(pktin); + changereq_first_time = FALSE; + } - s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; + + /* + * We need to reexamine the current pktin at the top + * of the loop. Either: + * - we weren't asked to change password at all, in + * which case it's a SUCCESS or FAILURE with the + * usual meaning + * - we sent a new password, and the server was + * either OK with it (SUCCESS or FAILURE w/partial + * success) or unhappy with the _old_ password + * (FAILURE w/o partial success) + * In any of these cases, we go back to the top of + * the loop and start again. + */ + s->gotit = TRUE; + + /* + * We don't need the old password any more, in any + * case. Burn the evidence. + */ + smemclr(s->password, strlen(s->password)); + sfree(s->password); + } else { - c_write_str(ssh, "No supported authentication methods" - " left to try!\r\n"); - logevent("No supported authentications offered." - " Disconnecting"); - ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(ssh, "No supported authentication" - " methods available"); - ssh2_pkt_addstring(ssh, "en"); /* language tag */ - ssh2_pkt_send(ssh); - ssh_closing((Plug)ssh, NULL, 0, 0); + char *str = dupprintf("No supported authentication methods available" + " (server sent: %.*s)", + methlen, methods); + + ssh_disconnect(ssh, str, + "No supported authentication methods available", + SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE, + FALSE); + sfree(str); + crStopV; + } + } - } while (!s->we_are_in); + } + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL; - /* - * Now we're authenticated for the connection protocol. The - * connection protocol will automatically have started at this - * point; there's no need to send SERVICE_REQUEST. - */ + /* Clear up various bits and pieces from authentication. */ + if (s->publickey_blob) { + sfree(s->publickey_blob); + sfree(s->publickey_comment); + } + if (s->agent_response) + sfree(s->agent_response); + + if (s->userauth_success) { + /* + * We've just received USERAUTH_SUCCESS, and we haven't sent any + * packets since. Signal the transport layer to consider enacting + * delayed compression. + * + * (Relying on we_are_in is not sufficient, as + * draft-miller-secsh-compression-delayed is quite clear that it + * triggers on USERAUTH_SUCCESS specifically, and we_are_in can + * become set for other reasons.) + */ + do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL); + } /* - * So now create a channel with a session in it. + * Now the connection protocol has started, one way or another. */ + ssh->channels = newtree234(ssh_channelcmp); - ssh->mainchan = snew(struct ssh_channel); - ssh->mainchan->ssh = ssh; - ssh->mainchan->localid = alloc_channel_id(ssh); - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN); - ssh2_pkt_addstring(ssh, "session"); - ssh2_pkt_adduint32(ssh, ssh->mainchan->localid); - ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE; - ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */ - ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */ - ssh2_pkt_send(ssh); - crWaitUntilV(ispkt); - if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { - bombout(("Server refused to open a session")); - crStopV; - /* FIXME: error data comes back in FAILURE packet */ - } - if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) { - bombout(("Server's channel confirmation cited wrong channel")); - crStopV; - } - ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh); - ssh->mainchan->type = CHAN_MAINSESSION; - ssh->mainchan->closes = 0; - ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh); - ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh); - bufchain_init(&ssh->mainchan->v.v2.outbuffer); - add234(ssh->channels, ssh->mainchan); - logevent("Opened channel for session"); /* - * Potentially enable X11 forwarding. + * Set up handlers for some connection protocol messages, so we + * don't have to handle them repeatedly in this coroutine. */ - if (ssh->cfg.x11_forward) { - char proto[20], data[64]; - logevent("Requesting X11 forwarding"); - ssh->x11auth = x11_invent_auth(proto, sizeof(proto), - data, sizeof(data), ssh->cfg.x11_auth); - x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display); - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); - ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); - ssh2_pkt_addstring(ssh, "x11-req"); - ssh2_pkt_addbool(ssh, 1); /* want reply */ - ssh2_pkt_addbool(ssh, 0); /* many connections */ - ssh2_pkt_addstring(ssh, proto); - ssh2_pkt_addstring(ssh, data); - ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display)); - ssh2_pkt_send(ssh); + ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = + ssh2_msg_channel_window_adjust; + ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = + ssh2_msg_global_request; - do { - crWaitUntilV(ispkt); - if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue; /* nonexistent channel */ - c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); - } - } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); + /* + * Create the main session channel. + */ + if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) { + ssh->mainchan = NULL; + } else { + ssh->mainchan = snew(struct ssh_channel); + ssh->mainchan->ssh = ssh; + ssh2_channel_init(ssh->mainchan); - if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { - if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Unexpected response to X11 forwarding request:" - " packet type %d", ssh->pktin.type)); - crStopV; - } - logevent("X11 forwarding refused"); + if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) { + /* + * Just start a direct-tcpip channel and use it as the main + * channel. + */ + ssh_send_port_open(ssh->mainchan, + conf_get_str(ssh->conf, CONF_ssh_nc_host), + conf_get_int(ssh->conf, CONF_ssh_nc_port), + "main channel"); + ssh->ncmode = TRUE; } else { - logevent("X11 forwarding enabled"); - ssh->X11_fwd_enabled = TRUE; + s->pktout = ssh2_chanopen_init(ssh->mainchan, "session"); + logevent("Opening session as main channel"); + ssh2_pkt_send(ssh, s->pktout); + ssh->ncmode = FALSE; } + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { + bombout(("Server refused to open channel")); + crStopV; + /* FIXME: error data comes back in FAILURE packet */ + } + if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) { + bombout(("Server's channel confirmation cited wrong channel")); + crStopV; + } + ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin); + ssh->mainchan->halfopen = FALSE; + ssh->mainchan->type = CHAN_MAINSESSION; + ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); + ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); + add234(ssh->channels, ssh->mainchan); + update_specials_menu(ssh->frontend); + logevent("Opened main channel"); } /* - * Enable port forwardings. + * Now we have a channel, make dispatch table entries for + * general channel-based messages. */ - { - char type; - int n; - int sport,dport,sserv,dserv; - char sports[256], dports[256], saddr[256], host[256]; - - ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); - /* Add port forwardings. */ - ssh->portfwd_strptr = ssh->cfg.portfwd; - while (*ssh->portfwd_strptr) { - type = *ssh->portfwd_strptr++; - saddr[0] = '\0'; - n = 0; - while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') { - if (*ssh->portfwd_strptr == ':') { - /* - * We've seen a colon in the middle of the - * source port number. This means that - * everything we've seen until now is the - * source _address_, so we'll move it into - * saddr and start sports from the beginning - * again. - */ - ssh->portfwd_strptr++; - sports[n] = '\0'; - strcpy(saddr, sports); - n = 0; - } - if (n < 255) sports[n++] = *ssh->portfwd_strptr++; - } - sports[n] = 0; - if (type != 'D') { - if (*ssh->portfwd_strptr == '\t') - ssh->portfwd_strptr++; - n = 0; - while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') { - if (n < 255) host[n++] = *ssh->portfwd_strptr++; - } - host[n] = 0; - if (*ssh->portfwd_strptr == ':') - ssh->portfwd_strptr++; - n = 0; - while (*ssh->portfwd_strptr) { - if (n < 255) dports[n++] = *ssh->portfwd_strptr++; - } - dports[n] = 0; - ssh->portfwd_strptr++; - dport = atoi(dports); - dserv = 0; - if (dport == 0) { - dserv = 1; - dport = net_service_lookup(dports); - if (!dport) { - logeventf(ssh, "Service lookup failed for destination" - " port \"%s\"", dports); - } - } - } else { - while (*ssh->portfwd_strptr) ssh->portfwd_strptr++; - dport = dserv = -1; - } - sport = atoi(sports); - sserv = 0; - if (sport == 0) { - sserv = 1; - sport = net_service_lookup(sports); - if (!sport) { - logeventf(ssh, "Service lookup failed for source" - " port \"%s\"", sports); - } - } - if (sport && dport) { - if (type == 'L') { - pfd_addforward(host, dport, *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s" - " forwarding to %s:%.*s%.*s%d%.*s", - (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL, - (int)(*saddr?1:0), ":", - (int)(sserv ? strlen(sports) : 0), sports, - sserv, "(", sport, sserv, ")", - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - } else if (type == 'D') { - pfd_addforward(NULL, -1, *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s" - " doing SOCKS dynamic forwarding", - (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL, - (int)(*saddr?1:0), ":", - (int)(sserv ? strlen(sports) : 0), sports, - sserv, "(", sport, sserv, ")"); - } else { - struct ssh_rportfwd *pf; - pf = snew(struct ssh_rportfwd); - strcpy(pf->dhost, host); - pf->dport = dport; - pf->sport = sport; - if (add234(ssh->rportfwds, pf) != pf) { - logeventf(ssh, "Duplicate remote port forwarding" - " to %s:%d", host, dport); - sfree(pf); - } else { - logeventf(ssh, "Requesting remote port " - "%.*s%.*s%.*s%.*s%d%.*s" - " forward to %s:%.*s%.*s%d%.*s", - (int)(*saddr?strlen(saddr):0), - *saddr?saddr:NULL, - (int)(*saddr?1:0), ":", - (int)(sserv ? strlen(sports) : 0), sports, - sserv, "(", sport, sserv, ")", - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST); - ssh2_pkt_addstring(ssh, "tcpip-forward"); - ssh2_pkt_addbool(ssh, 1);/* want reply */ - if (*saddr) - ssh2_pkt_addstring(ssh, saddr); - if (ssh->cfg.rport_acceptall) - ssh2_pkt_addstring(ssh, "0.0.0.0"); - else - ssh2_pkt_addstring(ssh, "127.0.0.1"); - ssh2_pkt_adduint32(ssh, sport); - ssh2_pkt_send(ssh); - - do { - crWaitUntilV(ispkt); - if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue;/* nonexistent channel */ - c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); - } - } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); - - if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) { - if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) { - bombout(("Unexpected response to port " - "forwarding request: packet type %d", - ssh->pktin.type)); - crStopV; - } - logevent("Server refused this port forwarding"); - } else { - logevent("Remote port forwarding enabled"); - } - } - } - } - } + ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = + ssh2_msg_channel_data; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = + ssh2_msg_channel_open_confirmation; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = + ssh2_msg_channel_open_failure; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = + ssh2_msg_channel_request; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = + ssh2_msg_channel_open; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response; + + + if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) { + /* + * This message indicates to the server that we promise + * not to try to run any other channel in parallel with + * this one, so it's safe for it to advertise a very large + * window and leave the flow control to TCP. + */ + s->pktout = ssh2_chanreq_init(ssh->mainchan, + "simple@putty.projects.tartarus.org", + NULL, NULL); + ssh2_pkt_send(ssh, s->pktout); } /* - * Potentially enable agent forwarding. + * Enable port forwardings. */ - if (ssh->cfg.agentfwd && agent_exists()) { - logevent("Requesting OpenSSH-style agent forwarding"); - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); - ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); - ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com"); - ssh2_pkt_addbool(ssh, 1); /* want reply */ - ssh2_pkt_send(ssh); - - do { - crWaitUntilV(ispkt); - if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue; /* nonexistent channel */ - c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); - } - } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); + ssh_setup_portfwd(ssh, ssh->conf); - if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { - if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Unexpected response to agent forwarding request:" - " packet type %d", ssh->pktin.type)); - crStopV; - } - logevent("Agent forwarding refused"); - } else { - logevent("Agent forwarding enabled"); - ssh->agentfwd_enabled = TRUE; - } - } + if (ssh->mainchan && !ssh->ncmode) { + /* + * Send the CHANNEL_REQUESTS for the main session channel. + * Each one is handled by its own little asynchronous + * co-routine. + */ - /* - * Now allocate a pty for the session. - */ - if (!ssh->cfg.nopty) { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); - ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */ - ssh2_pkt_addstring(ssh, "pty-req"); - ssh2_pkt_addbool(ssh, 1); /* want reply */ - ssh2_pkt_addstring(ssh, ssh->cfg.termtype); - ssh2_pkt_adduint32(ssh, ssh->term_width); - ssh2_pkt_adduint32(ssh, ssh->term_height); - ssh2_pkt_adduint32(ssh, 0); /* pixel width */ - ssh2_pkt_adduint32(ssh, 0); /* pixel height */ - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */ - ssh2_pkt_send(ssh); - ssh->state = SSH_STATE_INTERMED; + /* Potentially enable X11 forwarding. */ + if (conf_get_int(ssh->conf, CONF_x11_forward) && + (ssh->x11disp = + x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), + conf_get_int(ssh->conf, CONF_x11_auth), + ssh->conf))) + ssh2_setup_x11(ssh->mainchan, NULL, NULL); - do { - crWaitUntilV(ispkt); - if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue; /* nonexistent channel */ - c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); - } - } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); + /* Potentially enable agent forwarding. */ + if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) + ssh2_setup_agent(ssh->mainchan, NULL, NULL); - if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { - if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Unexpected response to pty request:" - " packet type %d", ssh->pktin.type)); - crStopV; - } - c_write_str(ssh, "Server refused to allocate pty\r\n"); - ssh->editing = ssh->echoing = 1; - } else { - logevent("Allocated pty"); - } - } else { - ssh->editing = ssh->echoing = 1; - } + /* Now allocate a pty for the session. */ + if (!conf_get_int(ssh->conf, CONF_nopty)) + ssh2_setup_pty(ssh->mainchan, NULL, NULL); - /* - * Start a shell or a remote command. We may have to attempt - * this twice if the config data has provided a second choice - * of command. - */ - while (1) { - int subsys; - char *cmd; + /* Send environment variables. */ + ssh2_setup_env(ssh->mainchan, NULL, NULL); - if (ssh->fallback_cmd) { - subsys = ssh->cfg.ssh_subsys2; - cmd = ssh->cfg.remote_cmd_ptr2; - } else { - subsys = ssh->cfg.ssh_subsys; - cmd = ssh->cfg.remote_cmd_ptr; - } + /* + * Start a shell or a remote command. We may have to attempt + * this twice if the config data has provided a second choice + * of command. + */ + while (1) { + int subsys; + char *cmd; - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); - ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */ - if (subsys) { - ssh2_pkt_addstring(ssh, "subsystem"); - ssh2_pkt_addbool(ssh, 1); /* want reply */ - ssh2_pkt_addstring(ssh, cmd); - } else if (*cmd) { - ssh2_pkt_addstring(ssh, "exec"); - ssh2_pkt_addbool(ssh, 1); /* want reply */ - ssh2_pkt_addstring(ssh, cmd); - } else { - ssh2_pkt_addstring(ssh, "shell"); - ssh2_pkt_addbool(ssh, 1); /* want reply */ - } - ssh2_pkt_send(ssh); - do { - crWaitUntilV(ispkt); - if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue; /* nonexistent channel */ - c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); + if (ssh->fallback_cmd) { + subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2); + cmd = conf_get_str(ssh->conf, CONF_remote_cmd2); + } else { + subsys = conf_get_int(ssh->conf, CONF_ssh_subsys); + cmd = conf_get_str(ssh->conf, CONF_remote_cmd); } - } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); - if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { - if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Unexpected response to shell/command request:" - " packet type %d", ssh->pktin.type)); - crStopV; + + if (subsys) { + s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem", + ssh2_response_authconn, NULL); + ssh2_pkt_addstring(s->pktout, cmd); + } else if (*cmd) { + s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec", + ssh2_response_authconn, NULL); + ssh2_pkt_addstring(s->pktout, cmd); + } else { + s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell", + ssh2_response_authconn, NULL); } - /* - * We failed to start the command. If this is the - * fallback command, we really are finished; if it's - * not, and if the fallback command exists, try falling - * back to it before complaining. - */ - if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) { - logevent("Primary command failed; attempting fallback"); - ssh->fallback_cmd = TRUE; - continue; + ssh2_pkt_send(ssh, s->pktout); + + crWaitUntilV(pktin); + + if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Unexpected response to shell/command request:" + " packet type %d", pktin->type)); + crStopV; + } + /* + * We failed to start the command. If this is the + * fallback command, we really are finished; if it's + * not, and if the fallback command exists, try falling + * back to it before complaining. + */ + if (!ssh->fallback_cmd && + *conf_get_str(ssh->conf, CONF_remote_cmd2)) { + logevent("Primary command failed; attempting fallback"); + ssh->fallback_cmd = TRUE; + continue; + } + bombout(("Server refused to start a shell/command")); + crStopV; + } else { + logevent("Started a shell/command"); } - bombout(("Server refused to start a shell/command")); - crStopV; - } else { - logevent("Started a shell/command"); + break; } - break; + } else { + ssh->editing = ssh->echoing = TRUE; } ssh->state = SSH_STATE_SESSION; @@ -5674,405 +9393,22 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) */ if (ssh->ldisc) ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ - ssh->send_ok = 1; + if (ssh->mainchan) + ssh->send_ok = 1; while (1) { crReturnV; s->try_send = FALSE; - if (ispkt) { - if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA || - ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { - char *data; - int length; - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue; /* nonexistent channel */ - if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && - ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR) - continue; /* extended but not stderr */ - ssh2_pkt_getstring(ssh, &data, &length); - if (data) { - int bufsize = 0; - c->v.v2.locwindow -= length; - switch (c->type) { - case CHAN_MAINSESSION: - bufsize = - from_backend(ssh->frontend, ssh->pktin.type == - SSH2_MSG_CHANNEL_EXTENDED_DATA, - data, length); - break; - case CHAN_X11: - bufsize = x11_send(c->u.x11.s, data, length); - break; - case CHAN_SOCKDATA: - bufsize = pfd_send(c->u.pfd.s, data, length); - break; - case CHAN_AGENT: - while (length > 0) { - if (c->u.a.lensofar < 4) { - int l = min(4 - c->u.a.lensofar, length); - memcpy(c->u.a.msglen + c->u.a.lensofar, - data, l); - data += l; - length -= l; - c->u.a.lensofar += l; - } - if (c->u.a.lensofar == 4) { - c->u.a.totallen = - 4 + GET_32BIT(c->u.a.msglen); - c->u.a.message = snewn(c->u.a.totallen, - unsigned char); - memcpy(c->u.a.message, c->u.a.msglen, 4); - } - if (c->u.a.lensofar >= 4 && length > 0) { - int l = - min(c->u.a.totallen - c->u.a.lensofar, - length); - memcpy(c->u.a.message + c->u.a.lensofar, - data, l); - data += l; - length -= l; - c->u.a.lensofar += l; - } - if (c->u.a.lensofar == c->u.a.totallen) { - void *reply; - int replylen; - if (agent_query(c->u.a.message, - c->u.a.totallen, - &reply, &replylen, - ssh_agentf_callback, c)) - ssh_agentf_callback(c, reply, replylen); - sfree(c->u.a.message); - c->u.a.lensofar = 0; - } - } - bufsize = 0; - break; - } - /* - * If we are not buffering too much data, - * enlarge the window again at the remote side. - */ - if (bufsize < OUR_V2_WINSIZE) - ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); - } - } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue; /* nonexistent channel */ - - if (c->type == CHAN_X11) { - /* - * Remote EOF on an X11 channel means we should - * wrap up and close the channel ourselves. - */ - x11_close(c->u.x11.s); - sshfwd_close(c); - } else if (c->type == CHAN_AGENT) { - sshfwd_close(c); - } else if (c->type == CHAN_SOCKDATA) { - pfd_close(c->u.pfd.s); - sshfwd_close(c); - } - } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c || ((int)c->remoteid) == -1) { - bombout(("Received CHANNEL_CLOSE for %s channel %d\n", - c ? "half-open" : "nonexistent", i)); - crStopV; - } - /* Do pre-close processing on the channel. */ - switch (c->type) { - case CHAN_MAINSESSION: - break; /* nothing to see here, move along */ - case CHAN_X11: - if (c->u.x11.s != NULL) - x11_close(c->u.x11.s); - sshfwd_close(c); - break; - case CHAN_AGENT: - sshfwd_close(c); - break; - case CHAN_SOCKDATA: - if (c->u.pfd.s != NULL) - pfd_close(c->u.pfd.s); - sshfwd_close(c); - break; - } - if (c->closes == 0) { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE); - ssh2_pkt_adduint32(ssh, c->remoteid); - ssh2_pkt_send(ssh); - } - del234(ssh->channels, c); - bufchain_clear(&c->v.v2.outbuffer); - sfree(c); - - /* - * See if that was the last channel left open. - */ - if (count234(ssh->channels) == 0) { - logevent("All channels closed. Disconnecting"); -#if 0 - /* - * We used to send SSH_MSG_DISCONNECT here, - * because I'd believed that _every_ conforming - * SSH2 connection had to end with a disconnect - * being sent by at least one side; apparently - * I was wrong and it's perfectly OK to - * unceremoniously slam the connection shut - * when you're done, and indeed OpenSSH feels - * this is more polite than sending a - * DISCONNECT. So now we don't. - */ - ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(ssh, "All open channels closed"); - ssh2_pkt_addstring(ssh, "en"); /* language tag */ - ssh2_pkt_send(ssh); -#endif - ssh_closing((Plug)ssh, NULL, 0, 0); - crStopV; - } - continue; /* remote sends close; ignore (FIXME) */ - } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c || c->closes) - continue; /* nonexistent or closing channel */ - c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); - s->try_send = TRUE; - } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue; /* nonexistent channel */ - if (c->type != CHAN_SOCKDATA_DORMANT) - continue; /* dunno why they're confirming this */ - c->remoteid = ssh2_pkt_getuint32(ssh); - c->type = CHAN_SOCKDATA; - c->v.v2.remwindow = ssh2_pkt_getuint32(ssh); - c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh); - if (c->u.pfd.s) - pfd_confirm(c->u.pfd.s); - if (c->closes) { - /* - * We have a pending close on this channel, - * which we decided on before the server acked - * the channel open. So now we know the - * remoteid, we can close it again. - */ - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE); - ssh2_pkt_adduint32(ssh, c->remoteid); - ssh2_pkt_send(ssh); - } - } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) { - unsigned i = ssh2_pkt_getuint32(ssh); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue; /* nonexistent channel */ - if (c->type != CHAN_SOCKDATA_DORMANT) - continue; /* dunno why they're failing this */ - - logevent("Forwarded connection refused by server"); - - pfd_close(c->u.pfd.s); - - del234(ssh->channels, c); - sfree(c); - } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) { - unsigned localid; - char *type; - int typelen, want_reply; - struct ssh_channel *c; - - localid = ssh2_pkt_getuint32(ssh); - ssh2_pkt_getstring(ssh, &type, &typelen); - want_reply = ssh2_pkt_getbool(ssh); - - /* - * First, check that the channel exists. Otherwise, - * we can instantly disconnect with a rude message. - */ - c = find234(ssh->channels, &localid, ssh_channelfind); - if (!c) { - char buf[80]; - sprintf(buf, "Received channel request for nonexistent" - " channel %d", localid); - logevent(buf); - ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(ssh, buf); - ssh2_pkt_addstring(ssh, "en"); /* language tag */ - ssh2_pkt_send(ssh); - connection_fatal(ssh->frontend, "%s", buf); - ssh_closing((Plug)ssh, NULL, 0, 0); - crStopV; - } - - /* - * Having got the channel number, we now look at - * the request type string to see if it's something - * we recognise. - */ - if (typelen == 11 && !memcmp(type, "exit-status", 11) && - c == ssh->mainchan) { - /* We recognise "exit-status" on the primary channel. */ - char buf[100]; - ssh->exitcode = ssh2_pkt_getuint32(ssh); - sprintf(buf, "Server sent command exit status %d", - ssh->exitcode); - logevent(buf); - if (want_reply) { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS); - ssh2_pkt_adduint32(ssh, c->remoteid); - ssh2_pkt_send(ssh); - } - } else { - /* - * This is a channel request we don't know - * about, so we now either ignore the request - * or respond with CHANNEL_FAILURE, depending - * on want_reply. - */ - if (want_reply) { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE); - ssh2_pkt_adduint32(ssh, c->remoteid); - ssh2_pkt_send(ssh); - } - } - } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) { - char *type; - int typelen, want_reply; - - ssh2_pkt_getstring(ssh, &type, &typelen); - want_reply = ssh2_pkt_getbool(ssh); + if (pktin) { - /* - * We currently don't support any global requests - * at all, so we either ignore the request or - * respond with REQUEST_FAILURE, depending on - * want_reply. - */ - if (want_reply) { - ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE); - ssh2_pkt_send(ssh); - } - } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) { - char *type; - int typelen; - char *peeraddr; - int peeraddrlen; - int peerport; - char *error = NULL; - struct ssh_channel *c; - unsigned remid, winsize, pktsize; - ssh2_pkt_getstring(ssh, &type, &typelen); - c = snew(struct ssh_channel); - c->ssh = ssh; - - remid = ssh2_pkt_getuint32(ssh); - winsize = ssh2_pkt_getuint32(ssh); - pktsize = ssh2_pkt_getuint32(ssh); - - if (typelen == 3 && !memcmp(type, "x11", 3)) { - char *addrstr; - - ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen); - addrstr = snewn(peeraddrlen+1, char); - memcpy(addrstr, peeraddr, peeraddrlen); - peeraddr[peeraddrlen] = '\0'; - peerport = ssh2_pkt_getuint32(ssh); - - if (!ssh->X11_fwd_enabled) - error = "X11 forwarding is not enabled"; - else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c, - ssh->x11auth, addrstr, peerport, - &ssh->cfg) != NULL) { - error = "Unable to open an X11 connection"; - } else { - c->type = CHAN_X11; - } - - sfree(addrstr); - } else if (typelen == 15 && - !memcmp(type, "forwarded-tcpip", 15)) { - struct ssh_rportfwd pf, *realpf; - char *dummy; - int dummylen; - ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */ - pf.sport = ssh2_pkt_getuint32(ssh); - ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen); - peerport = ssh2_pkt_getuint32(ssh); - realpf = find234(ssh->rportfwds, &pf, NULL); - if (realpf == NULL) { - error = "Remote port is not recognised"; - } else { - const char *e = pfd_newconnect(&c->u.pfd.s, - realpf->dhost, - realpf->dport, c, - &ssh->cfg); - logeventf(ssh, "Received remote port open request" - " for %s:%d", realpf->dhost, realpf->dport); - if (e != NULL) { - logeventf(ssh, "Port open failed: %s", e); - error = "Port open failed"; - } else { - logevent("Forwarded port opened successfully"); - c->type = CHAN_SOCKDATA; - } - } - } else if (typelen == 22 && - !memcmp(type, "auth-agent@openssh.com", 3)) { - if (!ssh->agentfwd_enabled) - error = "Agent forwarding is not enabled"; - else { - c->type = CHAN_AGENT; /* identify channel type */ - c->u.a.lensofar = 0; - } - } else { - error = "Unsupported channel type requested"; - } + /* + * _All_ the connection-layer packets we expect to + * receive are now handled by the dispatch table. + * Anything that reaches here must be bogus. + */ - c->remoteid = remid; - if (error) { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE); - ssh2_pkt_adduint32(ssh, c->remoteid); - ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED); - ssh2_pkt_addstring(ssh, error); - ssh2_pkt_addstring(ssh, "en"); /* language tag */ - ssh2_pkt_send(ssh); - sfree(c); - } else { - c->localid = alloc_channel_id(ssh); - c->closes = 0; - c->v.v2.locwindow = OUR_V2_WINSIZE; - c->v.v2.remwindow = winsize; - c->v.v2.remmaxpkt = pktsize; - bufchain_init(&c->v.v2.outbuffer); - add234(ssh->channels, c); - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); - ssh2_pkt_adduint32(ssh, c->remoteid); - ssh2_pkt_adduint32(ssh, c->localid); - ssh2_pkt_adduint32(ssh, c->v.v2.locwindow); - ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */ - ssh2_pkt_send(ssh); - } - } else { - bombout(("Strange packet received: type %d", ssh->pktin.type)); - crStopV; - } - } else { + bombout(("Strange packet received: type %d", pktin->type)); + crStopV; + } else if (ssh->mainchan) { /* * We have spare data. Add it to the channel buffer. */ @@ -6085,30 +9421,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) /* * Try to send data on all channels if we can. */ - for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { - int bufsize; - if (c->closes) - continue; /* don't send on closing channels */ - bufsize = ssh2_try_send(c); - if (bufsize == 0) { - switch (c->type) { - case CHAN_MAINSESSION: - /* stdin need not receive an unthrottle - * notification since it will be polled */ - break; - case CHAN_X11: - x11_unthrottle(c->u.x11.s); - break; - case CHAN_AGENT: - /* agent sockets are request/response and need no - * buffer management */ - break; - case CHAN_SOCKDATA: - pfd_unthrottle(c->u.pfd.s); - break; - } - } - } + for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) + ssh2_try_send_and_unthrottle(ssh, c); } } @@ -6116,13 +9430,181 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) } /* - * Handle the top-level SSH2 protocol. + * Handlers for SSH-2 messages that might arrive at any moment. + */ +static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) +{ + /* log reason code in disconnect message */ + char *buf, *msg; + int reason, msglen; + + reason = ssh_pkt_getuint32(pktin); + ssh_pkt_getstring(pktin, &msg, &msglen); + + if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { + buf = dupprintf("Received disconnect message (%s)", + ssh2_disconnect_reasons[reason]); + } else { + buf = dupprintf("Received disconnect message (unknown" + " type %d)", reason); + } + logevent(buf); + sfree(buf); + buf = dupprintf("Disconnection message text: %.*s", + msglen, msg); + logevent(buf); + bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"", + reason, + (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? + ssh2_disconnect_reasons[reason] : "unknown", + msglen, msg)); + sfree(buf); +} + +static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) +{ + /* log the debug message */ + char *msg; + int msglen; + + /* XXX maybe we should actually take notice of the return value */ + ssh2_pkt_getbool(pktin); + ssh_pkt_getstring(pktin, &msg, &msglen); + + logeventf(ssh, "Remote debug message: %.*s", msglen, msg); +} + +static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin) +{ + do_ssh2_transport(ssh, NULL, 0, pktin); +} + +/* + * Called if we receive a packet that isn't allowed by the protocol. + * This only applies to packets whose meaning PuTTY understands. + * Entirely unknown packets are handled below. + */ +static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin) +{ + char *buf = dupprintf("Server protocol violation: unexpected %s packet", + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, + pktin->type)); + ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); + sfree(buf); +} + +static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) +{ + struct Packet *pktout; + pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED); + ssh2_pkt_adduint32(pktout, pktin->sequence); + /* + * UNIMPLEMENTED messages MUST appear in the same order as the + * messages they respond to. Hence, never queue them. + */ + ssh2_pkt_send_noqueue(ssh, pktout); +} + +/* + * Handle the top-level SSH-2 protocol. */ -static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt) +static void ssh2_protocol_setup(Ssh ssh) +{ + int i; + + /* + * Most messages cause SSH2_MSG_UNIMPLEMENTED. + */ + for (i = 0; i < 256; i++) + ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented; + + /* + * Initially, we only accept transport messages (and a few generic + * ones). do_ssh2_authconn will add more when it starts. + * Messages that are understood but not currently acceptable go to + * ssh2_msg_unexpected. + */ + ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport; + /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */ + /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */ + ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected; + /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */ + /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */ + ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected; + + /* + * These messages have a special handler from the start. + */ + ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect; + ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */ + ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug; +} + +static void ssh2_timer(void *ctx, unsigned long now) +{ + Ssh ssh = (Ssh)ctx; + + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 && + now == ssh->next_rekey) { + do_ssh2_transport(ssh, "timeout", -1, NULL); + } +} + +static void ssh2_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin) { - if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0) + unsigned char *in = (unsigned char *)vin; + if (ssh->state == SSH_STATE_CLOSED) return; - do_ssh2_authconn(ssh, in, inlen, ispkt); + + if (pktin) { + ssh->incoming_data_size += pktin->encrypted_len; + if (!ssh->kex_in_progress && + ssh->max_data_size != 0 && + ssh->incoming_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data received", -1, NULL); + } + + if (pktin) + ssh->packet_dispatch[pktin->type](ssh, pktin); + else if (!ssh->protocol_initial_phase_done) + do_ssh2_transport(ssh, in, inlen, pktin); + else + do_ssh2_authconn(ssh, in, inlen, pktin); +} + +static void ssh_cache_conf_values(Ssh ssh) +{ + ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata); } /* @@ -6131,14 +9613,15 @@ static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt) * Returns an error message, or NULL on success. */ static const char *ssh_init(void *frontend_handle, void **backend_handle, - Config *cfg, - char *host, int port, char **realhost, int nodelay) + Conf *conf, char *host, int port, char **realhost, + int nodelay, int keepalive) { const char *p; Ssh ssh; ssh = snew(struct ssh_tag); - ssh->cfg = *cfg; /* STRUCTURE COPY */ + ssh->conf = conf_copy(conf); + ssh_cache_conf_values(ssh); ssh->version = 0; /* when not ready yet */ ssh->s = NULL; ssh->cipher = NULL; @@ -6160,38 +9643,45 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->kex_ctx = NULL; ssh->hostkey = NULL; ssh->exitcode = -1; + ssh->close_expected = FALSE; + ssh->clean_exit = FALSE; ssh->state = SSH_STATE_PREPACKET; ssh->size_needed = FALSE; ssh->eof_needed = FALSE; ssh->ldisc = NULL; ssh->logctx = NULL; - { - static const struct Packet empty = { 0, 0, NULL, NULL, 0 }; - ssh->pktin = ssh->pktout = empty; - } ssh->deferred_send_data = NULL; ssh->deferred_len = 0; ssh->deferred_size = 0; ssh->fallback_cmd = 0; - ssh->pkt_ctx = 0; - ssh->x11auth = NULL; + ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; + ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; + ssh->x11disp = NULL; ssh->v1_compressing = FALSE; ssh->v2_outgoing_sequence = 0; ssh->ssh1_rdpkt_crstate = 0; ssh->ssh2_rdpkt_crstate = 0; - ssh->do_ssh_init_crstate = 0; ssh->ssh_gotdata_crstate = 0; - ssh->ssh1_protocol_crstate = 0; - ssh->do_ssh1_login_crstate = 0; - ssh->do_ssh2_transport_crstate = 0; - ssh->do_ssh2_authconn_crstate = 0; + ssh->do_ssh1_connection_crstate = 0; ssh->do_ssh_init_state = NULL; ssh->do_ssh1_login_state = NULL; ssh->do_ssh2_transport_state = NULL; ssh->do_ssh2_authconn_state = NULL; + ssh->v_c = NULL; + ssh->v_s = NULL; ssh->mainchan = NULL; ssh->throttled_all = 0; ssh->v1_stdout_throttling = 0; + ssh->queue = NULL; + ssh->queuelen = ssh->queuesize = 0; + ssh->queueing = FALSE; + ssh->qhead = ssh->qtail = NULL; + ssh->deferred_rekey_reason = NULL; + bufchain_init(&ssh->queued_incoming_data); + ssh->frozen = FALSE; + ssh->username = NULL; + ssh->sent_console_eof = FALSE; + ssh->got_pty = FALSE; *backend_handle = ssh; @@ -6201,25 +9691,42 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, #endif ssh->frontend = frontend_handle; - ssh->term_width = ssh->cfg.width; - ssh->term_height = ssh->cfg.height; + ssh->term_width = conf_get_int(ssh->conf, CONF_width); + ssh->term_height = conf_get_int(ssh->conf, CONF_height); ssh->channels = NULL; ssh->rportfwds = NULL; + ssh->portfwds = NULL; ssh->send_ok = 0; ssh->editing = 0; ssh->echoing = 0; - ssh->v1_throttle_count = 0; + ssh->conn_throttle_count = 0; ssh->overall_bufsize = 0; ssh->fallback_cmd = 0; ssh->protocol = NULL; - p = connect_to_host(ssh, host, port, realhost, nodelay); + ssh->protocol_initial_phase_done = FALSE; + + ssh->pinger = NULL; + + ssh->incoming_data_size = ssh->outgoing_data_size = + ssh->deferred_data_size = 0L; + ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf, + CONF_ssh_rekey_data)); + ssh->kex_in_progress = FALSE; + +#ifndef NO_GSSAPI + ssh->gsslibs = NULL; +#endif + + p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive); if (p != NULL) return p; + random_ref(); + return NULL; } @@ -6239,14 +9746,33 @@ static void ssh_free(void *handle) ssh->csmac->free_context(ssh->cs_mac_ctx); if (ssh->sc_mac_ctx) ssh->scmac->free_context(ssh->sc_mac_ctx); - if (ssh->cs_comp_ctx) - ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); - if (ssh->sc_comp_ctx) - ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx); + if (ssh->cs_comp_ctx) { + if (ssh->cscomp) + ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); + else + zlib_compress_cleanup(ssh->cs_comp_ctx); + } + if (ssh->sc_comp_ctx) { + if (ssh->sccomp) + ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); + else + zlib_decompress_cleanup(ssh->sc_comp_ctx); + } if (ssh->kex_ctx) dh_cleanup(ssh->kex_ctx); sfree(ssh->savedhost); + while (ssh->queuelen-- > 0) + ssh_free_packet(ssh->queue[ssh->queuelen]); + sfree(ssh->queue); + + while (ssh->qhead) { + struct queued_handler *qh = ssh->qhead; + ssh->qhead = qh->next; + sfree(qh); + } + ssh->qhead = ssh->qtail = NULL; + if (ssh->channels) { while ((c = delpos234(ssh->channels, 0)) != NULL) { switch (c->type) { @@ -6255,50 +9781,135 @@ static void ssh_free(void *handle) x11_close(c->u.x11.s); break; case CHAN_SOCKDATA: + case CHAN_SOCKDATA_DORMANT: if (c->u.pfd.s != NULL) pfd_close(c->u.pfd.s); break; } + if (ssh->version == 2) { + struct outstanding_channel_request *ocr, *nocr; + ocr = c->v.v2.chanreq_head; + while (ocr) { + ocr->handler(c, NULL, ocr->ctx); + nocr = ocr->next; + sfree(ocr); + ocr = nocr; + } + bufchain_clear(&c->v.v2.outbuffer); + } sfree(c); } freetree234(ssh->channels); + ssh->channels = NULL; } if (ssh->rportfwds) { while ((pf = delpos234(ssh->rportfwds, 0)) != NULL) - sfree(pf); + free_rportfwd(pf); freetree234(ssh->rportfwds); + ssh->rportfwds = NULL; } sfree(ssh->deferred_send_data); - if (ssh->x11auth) - x11_free_auth(ssh->x11auth); + if (ssh->x11disp) + x11_free_display(ssh->x11disp); sfree(ssh->do_ssh_init_state); sfree(ssh->do_ssh1_login_state); sfree(ssh->do_ssh2_transport_state); sfree(ssh->do_ssh2_authconn_state); - + sfree(ssh->v_c); + sfree(ssh->v_s); + sfree(ssh->fullhostname); + if (ssh->crcda_ctx) { + crcda_free_context(ssh->crcda_ctx); + ssh->crcda_ctx = NULL; + } if (ssh->s) - ssh_do_close(ssh); + ssh_do_close(ssh, TRUE); + expire_timer_context(ssh); + if (ssh->pinger) + pinger_free(ssh->pinger); + bufchain_clear(&ssh->queued_incoming_data); + sfree(ssh->username); + conf_free(ssh->conf); +#ifndef NO_GSSAPI + if (ssh->gsslibs) + ssh_gss_cleanup(ssh->gsslibs); +#endif sfree(ssh); + + random_unref(); } /* * Reconfigure the SSH backend. - * - * Currently, this function does nothing very useful. In future, - * however, we could do some handy things with it. For example, we - * could make the port forwarding configurer active in the Change - * Settings box, and this routine could close down existing - * forwardings and open up new ones in response to changes. */ -static void ssh_reconfig(void *handle, Config *cfg) +static void ssh_reconfig(void *handle, Conf *conf) { Ssh ssh = (Ssh) handle; - ssh->cfg = *cfg; /* STRUCTURE COPY */ + char *rekeying = NULL, rekey_mandatory = FALSE; + unsigned long old_max_data_size; + int i, rekey_time; + + pinger_reconfig(ssh->pinger, ssh->conf, conf); + if (ssh->portfwds) + ssh_setup_portfwd(ssh, conf); + + rekey_time = conf_get_int(conf, CONF_ssh_rekey_time); + if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time && + rekey_time != 0) { + unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC; + unsigned long now = GETTICKCOUNT(); + + if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) { + rekeying = "timeout shortened"; + } else { + ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh); + } + } + + old_max_data_size = ssh->max_data_size; + ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf, + CONF_ssh_rekey_data)); + if (old_max_data_size != ssh->max_data_size && + ssh->max_data_size != 0) { + if (ssh->outgoing_data_size > ssh->max_data_size || + ssh->incoming_data_size > ssh->max_data_size) + rekeying = "data limit lowered"; + } + + if (conf_get_int(ssh->conf, CONF_compression) != + conf_get_int(conf, CONF_compression)) { + rekeying = "compression setting changed"; + rekey_mandatory = TRUE; + } + + for (i = 0; i < CIPHER_MAX; i++) + if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) != + conf_get_int_int(conf, CONF_ssh_cipherlist, i)) { + rekeying = "cipher settings changed"; + rekey_mandatory = TRUE; + } + if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) != + conf_get_int(conf, CONF_ssh2_des_cbc)) { + rekeying = "cipher settings changed"; + rekey_mandatory = TRUE; + } + + conf_free(ssh->conf); + ssh->conf = conf_copy(conf); + ssh_cache_conf_values(ssh); + + if (rekeying) { + if (!ssh->kex_in_progress) { + do_ssh2_transport(ssh, rekeying, -1, NULL); + } else if (rekey_mandatory) { + ssh->deferred_rekey_reason = rekeying; + } + } } /* - * Called to send data down the Telnet connection. + * Called to send data down the SSH connection. */ static int ssh_send(void *handle, char *buf, int len) { @@ -6334,7 +9945,7 @@ static int ssh_sendbuffer(void *handle) if (ssh->version == 1) { return override_value; } else if (ssh->version == 2) { - if (!ssh->mainchan || ssh->mainchan->closes > 0) + if (!ssh->mainchan) return override_value; else return (override_value + @@ -6350,6 +9961,7 @@ static int ssh_sendbuffer(void *handle) static void ssh_size(void *handle, int width, int height) { Ssh ssh = (Ssh) handle; + struct Packet *pktout; ssh->term_width = width; ssh->term_height = height; @@ -6363,22 +9975,20 @@ static void ssh_size(void *handle, int width, int height) ssh->size_needed = TRUE; /* buffer for later */ break; case SSH_STATE_SESSION: - if (!ssh->cfg.nopty) { + if (!conf_get_int(ssh->conf, CONF_nopty)) { if (ssh->version == 1) { send_packet(ssh, SSH1_CMSG_WINDOW_SIZE, PKT_INT, ssh->term_height, PKT_INT, ssh->term_width, PKT_INT, 0, PKT_INT, 0, PKT_END); - } else { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); - ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); - ssh2_pkt_addstring(ssh, "window-change"); - ssh2_pkt_addbool(ssh, 0); - ssh2_pkt_adduint32(ssh, ssh->term_width); - ssh2_pkt_adduint32(ssh, ssh->term_height); - ssh2_pkt_adduint32(ssh, 0); - ssh2_pkt_adduint32(ssh, 0); - ssh2_pkt_send(ssh); + } else if (ssh->mainchan) { + pktout = ssh2_chanreq_init(ssh->mainchan, "window-change", + NULL, NULL); + ssh2_pkt_adduint32(pktout, ssh->term_width); + ssh2_pkt_adduint32(pktout, ssh->term_height); + ssh2_pkt_adduint32(pktout, 0); + ssh2_pkt_adduint32(pktout, 0); + ssh2_pkt_send(ssh, pktout); } } break; @@ -6391,33 +10001,83 @@ static void ssh_size(void *handle, int width, int height) */ static const struct telnet_special *ssh_get_specials(void *handle) { + static const struct telnet_special ssh1_ignore_special[] = { + {"IGNORE message", TS_NOP} + }; + static const struct telnet_special ssh2_ignore_special[] = { + {"IGNORE message", TS_NOP}, + }; + static const struct telnet_special ssh2_rekey_special[] = { + {"Repeat key exchange", TS_REKEY}, + }; + static const struct telnet_special ssh2_session_specials[] = { + {NULL, TS_SEP}, + {"Break", TS_BRK}, + /* These are the signal names defined by RFC 4254. + * They include all the ISO C signals, but are a subset of the POSIX + * required signals. */ + {"SIGINT (Interrupt)", TS_SIGINT}, + {"SIGTERM (Terminate)", TS_SIGTERM}, + {"SIGKILL (Kill)", TS_SIGKILL}, + {"SIGQUIT (Quit)", TS_SIGQUIT}, + {"SIGHUP (Hangup)", TS_SIGHUP}, + {"More signals", TS_SUBMENU}, + {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM}, + {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL}, + {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV}, + {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2}, + {NULL, TS_EXITMENU} + }; + static const struct telnet_special specials_end[] = { + {NULL, TS_EXITMENU} + }; + /* XXX review this length for any changes: */ + static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) + + lenof(ssh2_rekey_special) + + lenof(ssh2_session_specials) + + lenof(specials_end)]; Ssh ssh = (Ssh) handle; + int i = 0; +#define ADD_SPECIALS(name) \ + do { \ + assert((i + lenof(name)) <= lenof(ssh_specials)); \ + memcpy(&ssh_specials[i], name, sizeof name); \ + i += lenof(name); \ + } while(0) if (ssh->version == 1) { - static const struct telnet_special ssh1_specials[] = { - {"IGNORE message", TS_NOP}, - {NULL, 0} - }; - return ssh1_specials; + /* Don't bother offering IGNORE if we've decided the remote + * won't cope with it, since we wouldn't bother sending it if + * asked anyway. */ + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) + ADD_SPECIALS(ssh1_ignore_special); } else if (ssh->version == 2) { - static const struct telnet_special ssh2_specials[] = { - {"Break", TS_BRK}, - {"IGNORE message", TS_NOP}, - {NULL, 0} - }; - return ssh2_specials; - } else + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) + ADD_SPECIALS(ssh2_ignore_special); + if (!(ssh->remote_bugs & BUG_SSH2_REKEY)) + ADD_SPECIALS(ssh2_rekey_special); + if (ssh->mainchan) + ADD_SPECIALS(ssh2_session_specials); + } /* else we're not ready yet */ + + if (i) { + ADD_SPECIALS(specials_end); + return ssh_specials; + } else { return NULL; + } +#undef ADD_SPECIALS } /* - * Send Telnet special codes. TS_EOF is useful for `plink', so you + * Send special codes. TS_EOF is useful for `plink', so you * can send an EOF and collect resulting output (e.g. `plink * hostname sort'). */ static void ssh_special(void *handle, Telnet_Special code) { Ssh ssh = (Ssh) handle; + struct Packet *pktout; if (code == TS_EOF) { if (ssh->state != SSH_STATE_SESSION) { @@ -6431,10 +10091,9 @@ static void ssh_special(void *handle, Telnet_Special code) } if (ssh->version == 1) { send_packet(ssh, SSH1_CMSG_EOF, PKT_END); - } else { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF); - ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); - ssh2_pkt_send(ssh); + } else if (ssh->mainchan) { + sshfwd_write_eof(ssh->mainchan); + ssh->send_ok = 0; /* now stop trying to read from stdin */ } logevent("Sent EOF message"); } else if (code == TS_PING || code == TS_NOP) { @@ -6444,25 +10103,55 @@ static void ssh_special(void *handle, Telnet_Special code) if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); } else { - ssh2_pkt_init(ssh, SSH2_MSG_IGNORE); - ssh2_pkt_addstring_start(ssh); - ssh2_pkt_send(ssh); + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { + pktout = ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(pktout); + ssh2_pkt_send_noqueue(ssh, pktout); + } + } + } else if (code == TS_REKEY) { + if (!ssh->kex_in_progress && ssh->version == 2) { + do_ssh2_transport(ssh, "at user request", -1, NULL); } } else if (code == TS_BRK) { if (ssh->state == SSH_STATE_CLOSED || ssh->state == SSH_STATE_PREPACKET) return; if (ssh->version == 1) { - logevent("Unable to send BREAK signal in SSH1"); - } else { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); - ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); - ssh2_pkt_addstring(ssh, "break"); - ssh2_pkt_addbool(ssh, 0); - ssh2_pkt_adduint32(ssh, 0); /* default break length */ - ssh2_pkt_send(ssh); + logevent("Unable to send BREAK signal in SSH-1"); + } else if (ssh->mainchan) { + pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL); + ssh2_pkt_adduint32(pktout, 0); /* default break length */ + ssh2_pkt_send(ssh, pktout); } } else { - /* do nothing */ + /* Is is a POSIX signal? */ + char *signame = NULL; + if (code == TS_SIGABRT) signame = "ABRT"; + if (code == TS_SIGALRM) signame = "ALRM"; + if (code == TS_SIGFPE) signame = "FPE"; + if (code == TS_SIGHUP) signame = "HUP"; + if (code == TS_SIGILL) signame = "ILL"; + if (code == TS_SIGINT) signame = "INT"; + if (code == TS_SIGKILL) signame = "KILL"; + if (code == TS_SIGPIPE) signame = "PIPE"; + if (code == TS_SIGQUIT) signame = "QUIT"; + if (code == TS_SIGSEGV) signame = "SEGV"; + if (code == TS_SIGTERM) signame = "TERM"; + if (code == TS_SIGUSR1) signame = "USR1"; + if (code == TS_SIGUSR2) signame = "USR2"; + /* The SSH-2 protocol does in principle support arbitrary named + * signals, including signame@domain, but we don't support those. */ + if (signame) { + /* It's a signal. */ + if (ssh->version == 2 && ssh->mainchan) { + pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL); + ssh2_pkt_addstring(pktout, signame); + ssh2_pkt_send(ssh, pktout); + logeventf(ssh, "Sent signal SIG%s", signame); + } + } else { + /* Never heard of it. Do nothing */ + } } } @@ -6471,17 +10160,13 @@ void *new_sock_channel(void *handle, Socket s) Ssh ssh = (Ssh) handle; struct ssh_channel *c; c = snew(struct ssh_channel); - c->ssh = ssh; - if (c) { - c->remoteid = -1; /* to be set when open confirmed */ - c->localid = alloc_channel_id(ssh); - c->closes = 0; - c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ - c->u.pfd.s = s; - bufchain_init(&c->v.v2.outbuffer); - add234(ssh->channels, c); - } + c->ssh = ssh; + ssh2_channel_init(c); + c->halfopen = TRUE; + c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ + c->u.pfd.s = s; + add234(ssh->channels, c); return c; } @@ -6492,57 +10177,74 @@ void *new_sock_channel(void *handle, Socket s) static void ssh_unthrottle(void *handle, int bufsize) { Ssh ssh = (Ssh) handle; + int buflimit; + if (ssh->version == 1) { if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { ssh->v1_stdout_throttling = 0; - ssh1_throttle(ssh, -1); + ssh_throttle_conn(ssh, -1); } } else { - if (ssh->mainchan && ssh->mainchan->closes == 0) - ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize); + if (ssh->mainchan) { + ssh2_set_window(ssh->mainchan, + bufsize < ssh->mainchan->v.v2.locmaxwin ? + ssh->mainchan->v.v2.locmaxwin - bufsize : 0); + if (conf_get_int(ssh->conf, CONF_ssh_simple)) + buflimit = 0; + else + buflimit = ssh->mainchan->v.v2.locmaxwin; + if (ssh->mainchan->throttling_conn && bufsize <= buflimit) { + ssh->mainchan->throttling_conn = 0; + ssh_throttle_conn(ssh, -1); + } + } } + + /* + * Now process any SSH connection data that was stashed in our + * queue while we were frozen. + */ + ssh_process_queued_incoming_data(ssh); } void ssh_send_port_open(void *channel, char *hostname, int port, char *org) { struct ssh_channel *c = (struct ssh_channel *)channel; Ssh ssh = c->ssh; + struct Packet *pktout; - logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port); + logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org); if (ssh->version == 1) { send_packet(ssh, SSH1_MSG_PORT_OPEN, PKT_INT, c->localid, PKT_STR, hostname, PKT_INT, port, - //PKT_STR, , + /* PKT_STR, , */ PKT_END); } else { - ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN); - ssh2_pkt_addstring(ssh, "direct-tcpip"); - ssh2_pkt_adduint32(ssh, c->localid); - c->v.v2.locwindow = OUR_V2_WINSIZE; - ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */ - ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */ - ssh2_pkt_addstring(ssh, hostname); - ssh2_pkt_adduint32(ssh, port); + pktout = ssh2_chanopen_init(c, "direct-tcpip"); + ssh2_pkt_addstring(pktout, hostname); + ssh2_pkt_adduint32(pktout, port); /* * We make up values for the originator data; partly it's * too much hassle to keep track, and partly I'm not * convinced the server should be told details like that * about my local network configuration. + * The "originator IP address" is syntactically a numeric + * IP address, and some servers (e.g., Tectia) get upset + * if it doesn't match this syntax. */ - ssh2_pkt_addstring(ssh, "client-side-connection"); - ssh2_pkt_adduint32(ssh, 0); - ssh2_pkt_send(ssh); + ssh2_pkt_addstring(pktout, "0.0.0.0"); + ssh2_pkt_adduint32(pktout, 0); + ssh2_pkt_send(ssh, pktout); } } - -static Socket ssh_socket(void *handle) +static int ssh_connected(void *handle) { Ssh ssh = (Ssh) handle; - return ssh->s; + return ssh->s != NULL; } static int ssh_sendok(void *handle) @@ -6579,7 +10281,17 @@ static int ssh_return_exitcode(void *handle) if (ssh->s != NULL) return -1; else - return (ssh->exitcode >= 0 ? ssh->exitcode : 0); + return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX); +} + +/* + * cfg_info for SSH is the currently running version of the + * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.) + */ +static int ssh_cfg_info(void *handle) +{ + Ssh ssh = (Ssh) handle; + return ssh->version; } /* @@ -6602,12 +10314,15 @@ Backend ssh_backend = { ssh_size, ssh_special, ssh_get_specials, - ssh_socket, + ssh_connected, ssh_return_exitcode, ssh_sendok, ssh_ldisc, ssh_provide_ldisc, ssh_provide_logctx, ssh_unthrottle, + ssh_cfg_info, + "ssh", + PROT_SSH, 22 };