X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/39934deb5202149f98198c111a35c21cb4d0d0f8..2ccb2fc83a62d8ded4b0287b72384ce22a83000c:/ssh.c diff --git a/ssh.c b/ssh.c index 1d8e6b8d..75610c67 100644 --- a/ssh.c +++ b/ssh.c @@ -104,8 +104,9 @@ * 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_DHGROUP 0x0001 #define SSH2_PKTCTX_DHGEX 0x0002 +#define SSH2_PKTCTX_KEX_MASK 0x000F #define SSH2_PKTCTX_PUBLICKEY 0x0010 #define SSH2_PKTCTX_PASSWORD 0x0020 #define SSH2_PKTCTX_KBDINTER 0x0040 @@ -162,9 +163,113 @@ 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 +/* + * Codes for terminal modes. + * Most of these are the same in SSH-1 and SSH-2. + * This list is derived from draft-ietf-secsh-connect-25 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 static char *ssh1_pkt_type(int type) @@ -222,8 +327,8 @@ 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_KEXDH_INIT, SSH2_PKTCTX_DHGROUP); + translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP); 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); @@ -255,18 +360,6 @@ 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); } - /* Enumeration values for fields in SSH-1 packets */ enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM, @@ -318,14 +411,19 @@ enum { typedef struct ssh_tag *Ssh; 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 ssh2_pkt_adduint32(struct Packet *, unsigned long value); -static void ssh2_pkt_addstring_start(struct Packet *); -static void ssh2_pkt_addstring_str(struct Packet *, char *data); -static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len); -static void ssh2_pkt_addstring(struct Packet *, char *data); +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 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 *); @@ -341,60 +439,33 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * * - 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. */ #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_MAXPKT 0x4000UL 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_sha1, &ssh_hmac_md5 }; const static struct ssh_mac *buggymacs[] = { - &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none + &ssh_hmac_sha1_buggy, &ssh_hmac_md5 }; static void *ssh_comp_none_init(void) @@ -439,8 +510,10 @@ 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. @@ -476,11 +549,11 @@ 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 @@ -492,31 +565,58 @@ 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 long sequence; - 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 @@ -526,9 +626,9 @@ struct Packet { struct logblank_t *blanks; }; -static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, +static void ssh1_protocol(Ssh ssh, void *vin, int inlen, struct Packet *pktin); -static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, +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); @@ -539,10 +639,13 @@ 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 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, long now); +static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, + struct Packet *pktin); struct rdpkt1_state_tag { long len, pad, biglen, to_read; @@ -562,12 +665,22 @@ struct rdpkt2_state_tag { }; typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin); +typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx); + +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; @@ -592,7 +705,8 @@ 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[32]; + int v2_session_id_len; void *kex_ctx; char *savedhost; @@ -608,8 +722,10 @@ struct ssh_tag { tree234 *channels; /* indexed by local id */ struct ssh_channel *mainchan; /* primary session channel */ int exitcode; + int close_expected; + int clean_exit; - tree234 *rportfwds; + tree234 *rportfwds, *portfwds; enum { SSH_STATE_PREPACKET, @@ -635,6 +751,7 @@ struct ssh_tag { */ int fallback_cmd; + bufchain banner; /* accumulates banners during do_ssh2_authconn */ /* * Used for username and password input. */ @@ -643,7 +760,6 @@ struct ssh_tag { int userpass_input_bufpos; int userpass_input_echo; - char *portfwd_strptr; int pkt_ctx; void *x11auth; @@ -653,7 +769,7 @@ struct ssh_tag { 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; @@ -672,10 +788,10 @@ struct ssh_tag { struct rdpkt1_state_tag rdpkt1_state; struct rdpkt2_state_tag rdpkt2_state; - /* ssh1 and ssh2 use this for different things, but both use it */ + /* SSH-1 and SSH-2 use this for different things, but both use it */ int protocol_initial_phase_done; - void (*protocol) (Ssh ssh, unsigned char *in, int inlen, + void (*protocol) (Ssh ssh, void *vin, int inlen, struct Packet *pkt); struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen); @@ -688,10 +804,23 @@ struct ssh_tag { Config cfg; /* - * Used to transfer data back from async agent callbacks. + * 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 @@ -700,9 +829,25 @@ struct ssh_tag { handler_fn_t packet_dispatch[256]; /* + * Queues of one-off handler functions for success/failure + * indications from a request. + */ + struct queued_handler *qhead, *qtail; + + /* * 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; + long next_rekey, last_rekey; + char *deferred_rekey_reason; /* points to STATIC string; don't free */ }; #define logevent(s) logevent(ssh->frontend, s) @@ -723,7 +868,7 @@ static void logeventf(Ssh ssh, const char *fmt, ...) #define bombout(msg) \ do { \ char *text = dupprintf msg; \ - ssh_do_close(ssh); \ + ssh_do_close(ssh, FALSE); \ logevent(text); \ connection_fatal(ssh->frontend, "%s", text); \ sfree(text); \ @@ -748,6 +893,29 @@ static void end_log_omission(Ssh ssh, struct Packet *pkt) pkt->logmode = PKTLOG_EMIT; } +/* Helper function for common bits of parsing cfg.ttymodes. */ +static void parse_ttymodes(Ssh ssh, char *modes, + void (*do_mode)(void *data, char *mode, char *val), + void *data) +{ + while (*modes) { + char *t = strchr(modes, '\t'); + char *m = snewn(t-modes+1, char); + char *val; + strncpy(m, modes, t-modes); + m[t-modes] = '\0'; + if (*(t+1) == 'A') + val = get_ttymode(ssh->frontend, m); + else + val = dupstr(t+2); + if (val) + do_mode(data, m, val); + sfree(m); + sfree(val); + modes += strlen(modes) + 1; + } +} + static int ssh_channelcmp(void *av, void *bv) { struct ssh_channel *a = (struct ssh_channel *) av; @@ -795,6 +963,51 @@ 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; @@ -870,7 +1083,7 @@ static struct Packet *ssh_new_packet(void) { struct Packet *pkt = snew(struct Packet); - pkt->data = NULL; + pkt->body = pkt->data = NULL; pkt->maxlen = 0; pkt->logmode = PKTLOG_EMIT; pkt->nblanks = 0; @@ -1056,7 +1269,8 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) * _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) { + if (st->len < 0 || st->len > 35000 || st->pad < 4 || + st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) { bombout(("Incoming packet was garbled on decryption")); ssh_free_packet(st->pktin); crStop(NULL); @@ -1099,6 +1313,8 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) st->pktin->data + st->cipherblk, st->packetlen - st->cipherblk); + st->pktin->encrypted_len = st->packetlen; + /* * Check the MAC. */ @@ -1168,36 +1384,9 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) crFinish(st->pktin); } -static void ssh1_pktout_size(struct Packet *pkt, int len) -{ - int pad, biglen; - - len += 5; /* type and CRC */ - pad = 8 - (len % 8); - biglen = len + pad; - - pkt->length = len - 5; - if (pkt->maxlen < biglen) { - pkt->maxlen = biglen; - pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char); - } - pkt->body = pkt->data + 4 + pad + 1; -} - -static struct Packet *s_wrpkt_start(int type, int len) +static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p) { - struct Packet *pkt = ssh_new_packet(); - ssh1_pktout_size(pkt, len); - pkt->type = type; - /* Initialise log omission state */ - pkt->nblanks = 0; - pkt->blanks = NULL; - return pkt; -} - -static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt) -{ - int pad, biglen, i; + int pad, biglen, i, pktoffs; unsigned long crc; #ifdef __SC__ /* @@ -1210,12 +1399,10 @@ static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt) #endif int len; - pkt->body[-1] = pkt->type; - if (ssh->logctx) - log_packet(ssh->logctx, PKT_OUTGOING, pkt->type, - ssh1_pkt_type(pkt->type), - pkt->body, pkt->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); sfree(pkt->blanks); pkt->blanks = NULL; pkt->nblanks = 0; @@ -1224,132 +1411,99 @@ static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt) unsigned char *compblk; int complen; zlib_compress_block(ssh->cs_comp_ctx, - pkt->body - 1, pkt->length + 1, + pkt->data + 12, pkt->length - 12, &compblk, &complen); - ssh1_pktout_size(pkt, complen - 1); - memcpy(pkt->body - 1, compblk, complen); + memcpy(pkt->data + 12, compblk, complen); sfree(compblk); + pkt->length = complen + 12; } - len = pkt->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++) - pkt->data[i + 4] = random_byte(); - crc = crc32_compute(pkt->data + 4, biglen - 4); - PUT_32BIT(pkt->data + biglen, crc); - PUT_32BIT(pkt->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, pkt->data + 4, biglen); + ssh->cipher->encrypt(ssh->v1_cipher_ctx, + pkt->data + pktoffs + 4, biglen); - return biglen + 4; + if (offset_p) *offset_p = pktoffs; + return biglen + 4; /* len(length+padding+type+data+CRC) */ } static void s_wrpkt(Ssh ssh, struct Packet *pkt) { - int len, backlog; - len = s_wrpkt_prepare(ssh, pkt); - backlog = sk_write(ssh->s, (char *)pkt->data, len); + int len, backlog, offset; + len = s_wrpkt_prepare(ssh, pkt, &offset); + backlog = sk_write(ssh->s, (char *)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, struct Packet *pkt) { - int len; - len = s_wrpkt_prepare(ssh, pkt); + 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, pkt->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 struct Packet *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) { - switch (argtype) { - case PKT_INT: - (void) va_arg(ap1, int); - pktlen += 4; - break; - case PKT_CHAR: - (void) va_arg(ap1, int); - pktlen++; - break; - case PKT_DATA: - (void) va_arg(ap1, unsigned char *); - arglen = va_arg(ap1, int); - pktlen += arglen; - break; - case PKT_STR: - argp = va_arg(ap1, unsigned char *); - arglen = strlen((char *)argp); - pktlen += 4 + arglen; - break; - case PKT_BIGNUM: - bn = va_arg(ap1, Bignum); - pktlen += ssh1_bignum_length(bn); - break; - case PKTT_PASSWORD: - case PKTT_DATA: - case PKTT_OTHER: - /* ignore this pass */ - break; - default: - assert(0); - } - } - - pkt = s_wrpkt_start(pkttype, pktlen); - p = pkt->body; + pkt = ssh1_pkt_init(pkttype); - while ((argtype = va_arg(ap2, int)) != PKT_END) { - int offset = p - pkt->body, len = 0; + while ((argtype = va_arg(ap, int)) != PKT_END) { + unsigned char *argp, argchar; + unsigned long argint; + int arglen; switch (argtype) { /* Actual fields in the packet */ case PKT_INT: - argint = va_arg(ap2, int); - PUT_32BIT(p, argint); - len = 4; + argint = va_arg(ap, int); + ssh_pkt_adduint32(pkt, argint); break; case PKT_CHAR: - argchar = (unsigned char) va_arg(ap2, int); - *p = argchar; - len = 1; + argchar = (unsigned char) va_arg(ap, int); + ssh_pkt_addbyte(pkt, argchar); break; case PKT_DATA: - argp = va_arg(ap2, unsigned char *); - arglen = va_arg(ap2, int); - memcpy(p, argp, arglen); - len = 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(ap2, unsigned char *); - arglen = strlen((char *)argp); - PUT_32BIT(p, arglen); - memcpy(p + 4, argp, arglen); - len = arglen + 4; + argp = va_arg(ap, unsigned char *); + ssh_pkt_addstring(pkt, argp); break; case PKT_BIGNUM: - bn = va_arg(ap2, Bignum); - len = ssh1_write_bignum(p, bn); + bn = va_arg(ap, Bignum); + ssh1_pkt_addmp(pkt, bn); break; /* Tokens for modifications to packet logging */ case PKTT_PASSWORD: @@ -1362,16 +1516,6 @@ static struct Packet *construct_packet(Ssh ssh, int pkttype, end_log_omission(ssh, pkt); break; } - p += len; - /* Deal with logfile omission, if required. */ - if (len && (pkt->logmode != PKTLOG_EMIT)) { - pkt->nblanks++; - pkt->blanks = sresize(pkt->blanks, pkt->nblanks, - struct logblank_t); - pkt->blanks[pkt->nblanks-1].offset = offset; - pkt->blanks[pkt->nblanks-1].len = len; - pkt->blanks[pkt->nblanks-1].type = pkt->logmode; - } } return pkt; @@ -1380,27 +1524,21 @@ static struct Packet *construct_packet(Ssh ssh, int pkttype, static void send_packet(Ssh ssh, int pkttype, ...) { struct Packet *pkt; - va_list ap1, ap2; - va_start(ap1, pkttype); - va_start(ap2, pkttype); - pkt = construct_packet(ssh, pkttype, ap1, ap2); - va_end(ap2); - va_end(ap1); + va_list ap; + va_start(ap, pkttype); + pkt = construct_packet(ssh, pkttype, ap); + va_end(ap); s_wrpkt(ssh, pkt); - ssh_free_packet(pkt); } static void defer_packet(Ssh ssh, int pkttype, ...) { struct Packet *pkt; - va_list ap1, ap2; - va_start(ap1, pkttype); - va_start(ap2, pkttype); - pkt = construct_packet(ssh, pkttype, ap1, ap2); - va_end(ap2); - va_end(ap1); + va_list ap; + va_start(ap, pkttype); + pkt = construct_packet(ssh, pkttype, ap); + va_end(ap); s_wrpkt_defer(ssh, pkt); - ssh_free_packet(pkt); } static int ssh_versioncmp(char *a, char *b) @@ -1425,95 +1563,98 @@ 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(struct Packet *pkt, int length) +static void ssh_pkt_ensure(struct Packet *pkt, int length) { if (pkt->maxlen < length) { + unsigned char *body = pkt->body; + int offset = body ? pkt->data - body : 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(struct Packet *pkt, void *data, int len) +static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len) { if (pkt->logmode != PKTLOG_EMIT) { pkt->nblanks++; pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t); - pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6; + 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; - ssh2_pkt_ensure(pkt, pkt->length); + ssh_pkt_ensure(pkt, pkt->length); memcpy(pkt->data + pkt->length - len, data, len); } -static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte) +static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte) { - ssh2_pkt_adddata(pkt, &byte, 1); -} -static struct Packet *ssh2_pkt_init(int pkt_type) -{ - struct Packet *pkt = ssh_new_packet(); - pkt->length = 5; - ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type); - return pkt; + ssh_pkt_adddata(pkt, &byte, 1); } static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value) { - ssh2_pkt_adddata(pkt, &value, 1); + ssh_pkt_adddata(pkt, &value, 1); } -static void ssh2_pkt_adduint32(struct Packet *pkt, 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(pkt, x, 4); + ssh_pkt_adddata(pkt, x, 4); } -static void ssh2_pkt_addstring_start(struct Packet *pkt) +static void ssh_pkt_addstring_start(struct Packet *pkt) { - ssh2_pkt_adduint32(pkt, 0); + ssh_pkt_adduint32(pkt, 0); pkt->savedpos = pkt->length; } -static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data) +static void ssh_pkt_addstring_str(struct Packet *pkt, char *data) { - ssh2_pkt_adddata(pkt, data, strlen(data)); + ssh_pkt_adddata(pkt, data, strlen(data)); PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); } -static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len) +static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len) { - ssh2_pkt_adddata(pkt, data, len); + ssh_pkt_adddata(pkt, data, len); PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); } -static void ssh2_pkt_addstring(struct Packet *pkt, char *data) +static void ssh_pkt_addstring(struct Packet *pkt, char *data) { - ssh2_pkt_addstring_start(pkt); - ssh2_pkt_addstring_str(pkt, data); + ssh_pkt_addstring_start(pkt); + ssh_pkt_addstring_str(pkt, data); +} +static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b) +{ + int len = ssh1_bignum_length(b); + unsigned char *data = snewn(len, 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); @@ -1529,13 +1670,42 @@ 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(pkt); - ssh2_pkt_addstring_data(pkt, (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; + pkt->forcepad = 0; + ssh_pkt_addbyte(pkt, (unsigned char) pkt_type); + pkt->body = pkt->data + pkt->length; + 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 * pkt->data. Total length is returned. */ @@ -1546,7 +1716,7 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) if (ssh->logctx) log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5], ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]), - pkt->data + 6, pkt->length - 6, + pkt->body, pkt->length - (pkt->body - pkt->data), pkt->nblanks, pkt->blanks); sfree(pkt->blanks); pkt->blanks = NULL; pkt->nblanks = 0; @@ -1570,12 +1740,17 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) /* * 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 - (pkt->length + padding) % cipherblk) % cipherblk; + assert(padding <= 255); maclen = ssh->csmac ? ssh->csmac->len : 0; ssh2_pkt_ensure(pkt, pkt->length + padding + maclen); pkt->data[4] = padding; @@ -1592,6 +1767,8 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) ssh->cscipher->encrypt(ssh->cs_cipher_ctx, pkt->data, pkt->length + padding); + pkt->encrypted_len = pkt->length + padding; + /* Ready-to-send packet starts at pkt->data. We return length. */ return pkt->length + padding + maclen; } @@ -1623,28 +1800,62 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) * 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 SSH2 packet immediately, without queuing or deferring. + * Send an SSH-2 packet immediately, without queuing or deferring. */ static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) { int len; int backlog; + 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 = sk_write(ssh->s, (char *)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); } /* - * Defer an SSH2 packet. + * Defer an SSH-2 packet. */ -static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt) +static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore) { - int len = ssh2_pkt_construct(ssh, pkt); + int len; + if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) && + ssh->deferred_len == 0 && !noignore) { + /* + * 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_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, @@ -1653,11 +1864,12 @@ static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt) } 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 SSH2 packet. + * Queue an SSH-2 packet. */ static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt) { @@ -1683,6 +1895,7 @@ static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt) ssh2_pkt_send_noqueue(ssh, pkt); } +#if 0 /* disused */ /* * Either queue or defer a packet, depending on whether queueing is * set. @@ -1692,12 +1905,13 @@ 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); + ssh2_pkt_defer_noqueue(ssh, pkt, FALSE); } +#endif /* * 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 @@ -1718,10 +1932,17 @@ static void ssh_pkt_defersend(Ssh ssh) 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 all queued SSH2 packets. We send them by means of + * 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. */ @@ -1732,7 +1953,7 @@ static void ssh2_pkt_queuesend(Ssh ssh) assert(!ssh->queueing); for (i = 0; i < ssh->queuelen; i++) - ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]); + ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE); ssh->queuelen = 0; ssh_pkt_defersend(ssh); @@ -1752,17 +1973,17 @@ 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); } /* - * Packet decode functions for both SSH1 and SSH2. + * Packet decode functions for both SSH-1 and SSH-2. */ static unsigned long ssh_pkt_getuint32(struct Packet *pkt) { @@ -1853,7 +2074,7 @@ static Bignum ssh2_pkt_getmp(struct Packet *pkt) } /* - * 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 @@ -1949,7 +2170,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * 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 || @@ -1961,7 +2182,7 @@ 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 || @@ -1973,7 +2194,7 @@ 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 || @@ -1986,7 +2207,7 @@ 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 || @@ -1999,7 +2220,7 @@ 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 || @@ -2007,29 +2228,60 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) (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 && 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"); - } - - if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) { + logevent("We believe remote version has SSH-2 public-key-session-ID bug"); + } + + if (ssh->cfg.sshbug_rekey2 == FORCE_ON || + (ssh->cfg.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)))) { /* - * User specified the SSH2 DH GEX bug. + * These versions have the SSH-2 rekey bug. */ - ssh->remote_bugs |= BUG_SSH2_DH_GEX; - logevent("We believe remote version has SSH2 DH group exchange bug"); + ssh->remote_bugs |= BUG_SSH2_REKEY; + logevent("We believe remote version has SSH-2 rekey 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++; } } @@ -2047,23 +2299,20 @@ static int do_ssh_init(Ssh ssh, unsigned char c) 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; @@ -2092,14 +2341,8 @@ 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); /* @@ -2120,46 +2363,66 @@ static int do_ssh_init(Ssh ssh, unsigned char c) crStop(0); } - if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) { - /* - * Use v2 protocol. - */ - char verstring[80], vlog[100]; - sprintf(verstring, "SSH-2.0-%s", sshver); - SHA_Init(&ssh->exhashbase); - /* - * Hash our version string and their version string. - */ - 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; - ssh2_protocol_setup(ssh); - ssh->version = 2; - ssh->s_rdpkt = ssh2_rdpkt; - } else { - /* - * Use v1 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"); + { + char *verstring; + + if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) { + /* + * Construct a v2 version string. + */ + verstring = dupprintf("SSH-2.0-%s\015\012", sshver); + ssh->version = 2; + } else { + /* + * Construct a v1 version string. + */ + verstring = dupprintf("SSH-%s-%s\012", + (ssh_versioncmp(s->version, "1.5") <= 0 ? + s->version : "1.5"), + sshver); + ssh->version = 1; + } + + ssh_fix_verstring(verstring); + + if (ssh->version == 2) { + size_t len; + /* + * Hash our version string and their version string. + */ + len = strcspn(verstring, "\015\012"); + ssh->v_c = snewn(len + 1, char); + memcpy(ssh->v_c, verstring, len); + ssh->v_c[len] = 0; + 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; + + /* + * Initialise SSH-2 protocol. + */ + ssh->protocol = ssh2_protocol; + ssh2_protocol_setup(ssh); + ssh->s_rdpkt = ssh2_rdpkt; + } else { + /* + * Initialise SSH-1 protocol. + */ + ssh->protocol = ssh1_protocol; + ssh1_protocol_setup(ssh); + ssh->s_rdpkt = ssh1_rdpkt; + } + logeventf(ssh, "We claim version: %.*s", + strcspn(verstring, "\015\012"), verstring); sk_write(ssh->s, verstring, strlen(verstring)); - ssh->protocol = ssh1_protocol; - ssh1_protocol_setup(ssh); - ssh->version = 1; - ssh->s_rdpkt = ssh1_rdpkt; + sfree(verstring); + if (ssh->version == 2) + do_ssh2_transport(ssh, NULL, -1, NULL); } + + logeventf(ssh, "Using SSH protocol version %d", ssh->version); + update_specials_menu(ssh->frontend); ssh->state = SSH_STATE_BEFORE_SIZE; ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh); @@ -2169,6 +2432,50 @@ static int do_ssh_init(Ssh ssh, unsigned char c) crFinish(0); } +static void ssh_process_incoming_data(Ssh ssh, + unsigned char **data, int *datalen) +{ + struct Packet *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) { crBegin(ssh->ssh_gotdata_crstate); @@ -2196,40 +2503,55 @@ 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) { - struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen); - if (pktin) { - ssh->protocol(ssh, NULL, 0, pktin); - ssh_free_packet(pktin); + 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; - notify_remote_exit(ssh->frontend); + 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); @@ -2238,26 +2560,67 @@ static void ssh_do_close(Ssh ssh) 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); + } + } + + return ret; +} + +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 (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; } @@ -2266,7 +2629,7 @@ 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; @@ -2293,6 +2656,7 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, char **realhost, int nodelay, int keepalive) { static const struct plug_function_table fn_table = { + ssh_log, ssh_closing, ssh_receive, ssh_sent, @@ -2303,8 +2667,6 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, const char *err; ssh->savedhost = snewn(1 + strlen(host), char); - if (!ssh->savedhost) - fatalbox("Out of memory"); strcpy(ssh->savedhost, host); if (port < 0) @@ -2314,8 +2676,11 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, /* * Try to find host. */ - logeventf(ssh, "Looking up host \"%s\"", host); - addr = name_lookup(host, port, realhost, &ssh->cfg); + logeventf(ssh, "Looking up host \"%s\"%s", host, + (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" : + (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : ""))); + addr = name_lookup(host, port, realhost, &ssh->cfg, + ssh->cfg.addressfamily); if ((err = sk_addr_error(addr)) != NULL) { sk_addr_free(addr); return err; @@ -2324,11 +2689,6 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, /* * 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, keepalive, (Plug) ssh, &ssh->cfg); @@ -2350,9 +2710,9 @@ static void ssh1_throttle(Ssh ssh, int adjust) ssh->v1_throttle_count += adjust; assert(ssh->v1_throttle_count >= 0); if (ssh->v1_throttle_count && !old_count) { - sk_set_frozen(ssh->s, 1); + ssh_set_frozen(ssh, 1); } else if (!ssh->v1_throttle_count && old_count) { - sk_set_frozen(ssh->s, 0); + ssh_set_frozen(ssh, 0); } } @@ -2393,7 +2753,7 @@ 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. + * reusable in several places - even between SSH-1 and SSH-2. */ /* Set up a username or password input loop on a given buffer. */ @@ -2476,18 +2836,36 @@ static void ssh_agent_callback(void *sshv, void *reply, int replylen) do_ssh2_authconn(ssh, NULL, -1, NULL); } -static void ssh_agentf_callback(void *cv, void *reply, int replylen) +static void ssh_dialog_callback(void *sshv, int ret) { - struct ssh_channel *c = (struct ssh_channel *)cv; - Ssh ssh = c->ssh; - void *sentreply = reply; + Ssh ssh = (Ssh) sshv; - if (!sentreply) { - /* Fake SSH_AGENT_FAILURE. */ - sentreply = "\0\0\0\1\5"; - replylen = 5; - } - if (ssh->version == 2) { + ssh->user_response = ret; + + if (ssh->version == 1) + do_ssh1_login(ssh, NULL, -1, NULL); + else + 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) +{ + struct ssh_channel *c = (struct ssh_channel *)cv; + Ssh ssh = c->ssh; + void *sentreply = reply; + + if (!sentreply) { + /* Fake SSH_AGENT_FAILURE. */ + sentreply = "\0\0\0\1\5"; + replylen = 5; + } + if (ssh->version == 2) { ssh2_add_channel_data(c, sentreply, replylen); ssh2_try_send(c); } else { @@ -2504,6 +2882,39 @@ static void ssh_agentf_callback(void *cv, void *reply, int replylen) } /* + * 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, @@ -2537,13 +2948,12 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, Bignum challenge; char *commentp; int commentlen; + int dlgret; }; crState(do_ssh1_login_state); crBegin(ssh->do_ssh1_login_crstate); - random_init(); - if (!pktin) crWaitUntil(pktin); @@ -2556,14 +2966,14 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ptr = ssh_pkt_getdata(pktin, 8); if (!ptr) { - bombout(("SSH1 public key packet stopped before random cookie")); + bombout(("SSH-1 public key packet stopped before random cookie")); crStop(0); } memcpy(cookie, ptr, 8); if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) || !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) { - bombout(("Failed to read SSH1 public keys from public key packet")); + bombout(("Failed to read SSH-1 public keys from public key packet")); crStop(0); } @@ -2602,15 +3012,13 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, */ if (hostkey.bits > hostkey.bytes * 8 || servkey.bits > servkey.bytes * 8) { - bombout(("SSH1 public keys were badly formatted")); + bombout(("SSH-1 public keys were badly formatted")); crStop(0); } s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); s->rsabuf = snewn(s->len, unsigned char); - if (!s->rsabuf) - fatalbox("Out of memory"); /* * Verify the host key. @@ -2622,14 +3030,33 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int len = rsastr_len(&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); + + 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++) { @@ -2648,7 +3075,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey); } if (!ret) { - bombout(("SSH1 public key encryptions failed due to bad formatting")); + bombout(("SSH-1 public key encryptions failed due to bad formatting")); crStop(0); } @@ -2665,7 +3092,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, 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; @@ -2681,7 +3108,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } 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 */ @@ -2690,8 +3117,28 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } /* 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) { @@ -2762,8 +3209,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, * get_line failed to get a username. * Terminate. */ - logevent("No username provided. Abandoning session."); - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); crStop(1); } } else { @@ -2850,17 +3296,9 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->p = s->response + 5; s->nkeys = GET_32BIT(s->p); 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++) { - { - char buf[64]; - sprintf(buf, "Trying Pageant key #%d", s->keyi); - logevent(buf); - } + logeventf(ssh, "Trying Pageant key #%d", s->keyi); if (s->publickey_blob && !memcmp(s->p, s->publickey_blob, s->publickey_bloblen)) { @@ -3018,6 +3456,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, bombout(("TIS challenge packet was badly formed")); crStop(0); } + c_write_str(ssh, "Using TIS authentication.\r\n"); logevent("Received TIS challenge"); if (challengelen > sizeof(s->prompt) - 1) challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ @@ -3051,6 +3490,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, bombout(("CryptoCard challenge packet was badly formed")); crStop(0); } + c_write_str(ssh, "Using CryptoCard authentication.\r\n"); logevent("Received CryptoCard challenge"); if (challengelen > sizeof(s->prompt) - 1) challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ @@ -3069,18 +3509,18 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, 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); + char *msg = dupprintf("Key is of wrong type (%s)", + key_type_to_str(type)); + logevent(msg); + c_write_str(ssh, msg); c_write_str(ssh, "\r\n"); + sfree(msg); s->tried_publickey = 1; continue; } @@ -3106,12 +3546,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, * 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); + ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, FALSE); crStop(1); } } else { @@ -3362,20 +3797,18 @@ void sshfwd_close(struct ssh_channel *c) { Ssh ssh = c->ssh; - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); + if (ssh->state == SSH_STATE_CLOSED) return; - } if (c && !c->closes) { /* - * If the channel's remoteid is -1, we have sent + * If halfopen is true, 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 (!c->halfopen) { if (ssh->version == 1) { send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END); @@ -3402,10 +3835,8 @@ 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, @@ -3414,7 +3845,7 @@ int sshfwd_write(struct ssh_channel *c, char *buf, int len) PKT_INT, len, 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 @@ -3431,10 +3862,8 @@ void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) { Ssh ssh = c->ssh; - 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) { @@ -3446,275 +3875,900 @@ void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) } } -static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, - struct Packet *pktin) +static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin) { - crBegin(ssh->do_ssh1_connection_crstate); + struct queued_handler *qh = ssh->qhead; - if (ssh->cfg.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; + assert(qh != NULL); + + 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] = NULL; + } + if (qh->msg2 > 0) { + assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler); + ssh->packet_dispatch[qh->msg2] = NULL; + } + + if (qh->next) { + ssh->qhead = qh->next; + + if (ssh->qhead->msg1 > 0) { + assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL); + ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler; } + if (ssh->qhead->msg2 > 0) { + assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL); + ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler; + } + } else { + ssh->qhead = ssh->qtail = NULL; + ssh->packet_dispatch[pktin->type] = 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) { + assert(ssh->packet_dispatch[qh->msg1] == NULL); + ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler; } - 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; + if (qh->msg2 > 0) { + assert(ssh->packet_dispatch[qh->msg2] == NULL); + 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); + free_rportfwd(pf); + } +} + +static void ssh_setup_portfwd(Ssh ssh, const Config *cfg) +{ + const char *portfwd_strptr = cfg->portfwd; + struct ssh_portfwd *epf; + int i; + + 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; + } + + while (*portfwd_strptr) { + char address_family, type; int sport,dport,sserv,dserv; char sports[256], dports[256], saddr[256], host[256]; + int n; - 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'; + address_family = 'A'; + type = 'L'; + if (*portfwd_strptr == 'A' || + *portfwd_strptr == '4' || + *portfwd_strptr == '6') + address_family = *portfwd_strptr++; + if (*portfwd_strptr == 'L' || + *portfwd_strptr == 'R' || + *portfwd_strptr == 'D') + type = *portfwd_strptr++; + + saddr[0] = '\0'; + + n = 0; + while (*portfwd_strptr && *portfwd_strptr != '\t') { + if (*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. + */ + portfwd_strptr++; + sports[n] = '\0'; + if (ssh->version == 1 && type == 'R') { + logeventf(ssh, "SSH-1 cannot handle remote source address " + "spec \"%s\"; ignoring", sports); + } else 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); - } + } + if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++; + } + sports[n] = 0; + if (type != 'D') { + if (*portfwd_strptr == '\t') + portfwd_strptr++; + n = 0; + while (*portfwd_strptr && *portfwd_strptr != ':') { + if (n < lenof(host)-1) host[n++] = *portfwd_strptr++; + } + host[n] = 0; + if (*portfwd_strptr == ':') + portfwd_strptr++; + n = 0; + while (*portfwd_strptr) { + if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++; + } + dports[n] = 0; + 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 (*portfwd_strptr) portfwd_strptr++; + host[0] = 0; + dports[0] = 0; + dport = dserv = -1; + portfwd_strptr++; /* eat the NUL and move to next one */ + } + 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) { + /* Set up a description of the source port. */ + struct ssh_portfwd *pfrec, *epfrec; + + pfrec = snew(struct ssh_portfwd); + pfrec->type = type; + pfrec->saddr = *saddr ? dupstr(saddr) : NULL; + pfrec->sserv = sserv ? dupstr(sports) : NULL; + pfrec->sport = sport; + pfrec->daddr = *host ? dupstr(host) : NULL; + 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) { + /* + * We already have a port forwarding with precisely + * these parameters. Hence, no need to do anything; + * simply tag the existing one as KEEP. + */ + epfrec->status = KEEP; + free_portfwd(pfrec); } else { - while (*ssh->portfwd_strptr) ssh->portfwd_strptr++; - dport = dserv = -1; - ssh->portfwd_strptr++; /* eat the NUL and move to next one */ + 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); - } + } + } + + /* + * 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) { - /* Set up a description of the source port. */ - static char *sportdesc; - sportdesc = dupprintf("%.*s%.*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, ")"); - if (type == 'L') { - /* Verbose description of the destination port */ - char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s", - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - const char *err = pfd_addforward(host, dport, - *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - if (err) { - logeventf(ssh, "Local port %s forward to %s" - " failed: %s", sportdesc, dportdesc, err); - } else { - logeventf(ssh, "Local port %s forwarding to %s", - sportdesc, dportdesc); - } - sfree(dportdesc); - } else if (type == 'D') { - const char *err = pfd_addforward(NULL, -1, - *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - if (err) { - logeventf(ssh, "Local port %s SOCKS dynamic forward" - " setup failed: %s", sportdesc, err); + + logeventf(ssh, "Cancelling %s", message); + sfree(message); + + 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 { + 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 (ssh->cfg.rport_acceptall) { + /* XXX: ssh->cfg.rport_acceptall may not represent + * what was used to open the original connection, + * since it's reconfigurable. */ + ssh2_pkt_addstring(pktout, "0.0.0.0"); } else { - logeventf(ssh, "Local port %s doing SOCKS" - " dynamic forwarding", sportdesc); + ssh2_pkt_addstring(pktout, "127.0.0.1"); } + ssh2_pkt_adduint32(pktout, epf->sport); + ssh2_pkt_send(ssh, pktout); + } + + del234(ssh->rportfwds, rpf); + free_rportfwd(rpf); + } else if (epf->local) { + pfd_terminate(epf->local); + } + + delpos234(ssh->portfwds, i); + free_portfwd(epf); + i--; /* so we don't skip one in the list */ + } + + /* + * And finally, set up any new port forwardings (status==CREATE). + */ + 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 ? ")" : ""); + } + + if (epf->type == 'L') { + const char *err = pfd_addforward(epf->daddr, epf->dport, + epf->saddr, epf->sport, + ssh, cfg, + &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, cfg, + &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; + + /* + * 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); + } + + 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 { - 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); - } 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, ")"); + 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, sport, - PKT_STR, host, - PKT_INT, dport, + PKT_INT, epf->sport, + PKT_STR, epf->daddr, + PKT_INT, epf->dport, 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 port" - " forwarding\r\n"); + ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS, + SSH1_SMSG_FAILURE, + ssh_rportfwd_succfail, pf); + } else { + 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 (cfg->rport_acceptall) { + ssh2_pkt_addstring(pktout, "0.0.0.0"); + } else { + ssh2_pkt_addstring(pktout, "127.0.0.1"); } - logevent("Remote port forwarding enabled"); + ssh2_pkt_adduint32(pktout, epf->sport); + ssh2_pkt_send(ssh, pktout); + + ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, + SSH2_MSG_REQUEST_FAILURE, + ssh_rportfwd_succfail, pf); } } - sfree(sportdesc); } + sfree(sportdesc); + sfree(dportdesc); } +} + +static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin) +{ + char *string; + int stringlen, bufsize; + + ssh_pkt_getstring(pktin, &string, &stringlen); + if (string == NULL) { + bombout(("Incoming terminal data packet was badly formed")); + return; } - if (!ssh->cfg.nopty) { - /* 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(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed); - /* Send the pty request. */ - 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, /* width,height in pixels */ - PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */ - PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */ - PKT_CHAR, 0, PKT_END); - 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; - } - logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", - ssh->ospeed, ssh->ispeed); - } else { - ssh->editing = ssh->echoing = 1; + 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; + ssh1_throttle(ssh, +1); } +} - if (ssh->cfg.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"); +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; + + 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, 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->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"); } - 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. +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->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); + } +} + +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_channel *c; + struct ssh_rportfwd pf, *pfp; + int remoteid; + int hostsize, port; + char *host; + const char *e; + c = snew(struct ssh_channel); + c->ssh = ssh; + + 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 { + 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->cfg, 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->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"); + } + } +} + +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->v.v1.throttling = 0; + pfd_confirm(c->u.pfd.s); + } + + 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_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) { + int closetype; + closetype = + (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; + } + + c->closes |= (closetype << 2); /* seen this message */ + if (!(c->closes & closetype)) { + send_packet(ssh, pktin->type, PKT_INT, c->remoteid, + PKT_END); + c->closes |= closetype; /* sent it too */ + } + + if (c->closes == 15) { + del234(ssh->channels, c); + sfree(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, 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) { + unsigned 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); + } + } +} + +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 (ssh->cfg.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 (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); + /* + * 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, proto, + PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, + PKT_INT, x11_get_screen_number(ssh->cfg.x11_display), + PKT_END); + } else { + send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, + PKT_STR, proto, + PKTT_PASSWORD, PKT_STR, data, 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->cfg); + ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open; + + if (!ssh->cfg.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(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed); + /* Send the pty request. */ + pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY); + ssh_pkt_addstring(pkt, ssh->cfg.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, ssh->cfg.ttymodes, + 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; + } + logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", + ssh->ospeed, ssh->ispeed); + } else { + ssh->editing = ssh->echoing = 1; + } + + if (ssh->cfg.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 SSH2 + * 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 = ssh->cfg.remote_cmd_ptr; + + if (!cmd) cmd = ssh->cfg.remote_cmd; if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) { cmd = ssh->cfg.remote_cmd_ptr2; @@ -3738,313 +4792,20 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, ssh->send_ok = 1; ssh->channels = newtree234(ssh_channelcmp); while (1) { - crReturnV; - if (pktin) { - if (pktin->type == SSH1_SMSG_STDOUT_DATA || - pktin->type == SSH1_SMSG_STDERR_DATA) { - char *string; - int stringlen, bufsize; - - ssh_pkt_getstring(pktin, &string, &stringlen); - if (string == NULL) { - bombout(("Incoming terminal data packet was badly formed")); - crStopV; - } - - 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; - ssh1_throttle(ssh, +1); - } - } else if (pktin->type == SSH1_MSG_DISCONNECT) { - ssh_closing((Plug)ssh, NULL, 0, 0); - logevent("Received disconnect request"); - crStopV; - } else if (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; - 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; - - 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, remoteid, PKT_END); - } else { - logevent - ("Opening X11 forward connection succeeded"); - c->remoteid = remoteid; - 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 (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; - 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->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 (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 remoteid; - int hostsize, port; - char *host, buf[1024]; - const char *e; - c = snew(struct ssh_channel); - c->ssh = ssh; - - 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; - - if (find234(ssh->rportfwds, &pf, NULL) == NULL) { - sprintf(buf, "Rejected remote port open request for %s:%d", - pf.dhost, port); - logevent(buf); - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, - PKT_INT, remoteid, PKT_END); - } else { - sprintf(buf, "Received remote port open request for %s:%d", - pf.dhost, port); - logevent(buf); - e = pfd_newconnect(&c->u.pfd.s, pf.dhost, 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, remoteid, PKT_END); - } else { - c->remoteid = remoteid; - 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"); - } - } - - } else if (pktin->type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) { - 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->type = CHAN_SOCKDATA; - c->v.v1.throttling = 0; - pfd_confirm(c->u.pfd.s); - } - - 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); - } - - } else if (pktin->type == SSH1_MSG_CHANNEL_OPEN_FAILURE) { - 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); - } - - } else if (pktin->type == SSH1_MSG_CHANNEL_CLOSE || - pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { - /* Remote side closes a channel. */ - unsigned i = ssh_pkt_getuint32(pktin); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (c && ((int)c->remoteid) != -1) { - int closetype; - closetype = - (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; - } - c->closes |= (closetype << 2); /* seen this message */ - if (!(c->closes & closetype)) { - send_packet(ssh, pktin->type, PKT_INT, c->remoteid, - PKT_END); - c->closes |= closetype; /* sent it too */ - } + /* + * By this point, most incoming packets are already being + * handled by the dispatch table, and we need only pay + * attention to the unusual ones. + */ - if (c->closes == 15) { - del234(ssh->channels, c); - sfree(c); - } - } else { - bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n", - pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" : - "_CONFIRMATION", c ? "half-open" : "nonexistent", - i)); - crStopV; - } - } else if (pktin->type == SSH1_MSG_CHANNEL_DATA) { - /* 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) { - 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); - } - } - } else if (pktin->type == SSH1_SMSG_SUCCESS) { + crReturnV; + if (pktin) { + if (pktin->type == SSH1_SMSG_SUCCESS) { /* may be from EXEC_SHELL on some servers */ } 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 (pktin->type == SSH1_SMSG_EXIT_STATUS) { - char buf[100]; - ssh->exitcode = ssh_pkt_getuint32(pktin); - 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", pktin->type)); crStopV; @@ -4065,17 +4826,15 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, } /* - * Handle the top-level SSH2 protocol. + * Handle the top-level SSH-2 protocol. */ static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin) { - char *buf, *msg; + char *msg; int msglen; ssh_pkt_getstring(pktin, &msg, &msglen); - buf = dupprintf("Remote debug message: %.*s", msglen, msg); - logevent(buf); - sfree(buf); + logeventf(ssh, "Remote debug message: %.*s", msglen, msg); } static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) @@ -4088,7 +4847,7 @@ static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg)); } -void ssh_msg_ignore(Ssh ssh, struct Packet *pktin) +static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin) { /* Do nothing, because we're ignoring it! Duhh. */ } @@ -4111,9 +4870,10 @@ static void ssh1_protocol_setup(Ssh ssh) ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug; } -static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, +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; @@ -4164,39 +4924,64 @@ 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 int first_in_commasep_string(char *needle, char *haystack, int haylen) +{ + 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. */ -static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, - unsigned char *sessid, char chr, +static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr, unsigned char *keyspace) { - SHA_State s; - /* First 20 bytes. */ - SHA_Init(&s); + const struct ssh_hash *h = ssh->kex->hash; + void *s; + /* First hlen bytes. */ + s = h->init(); 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); + 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)) - sha_mpint(&s, K); - SHA_Bytes(&s, H, 20); - SHA_Bytes(&s, keyspace, 20); - SHA_Final(&s, keyspace + 20); + 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, +static int 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 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; @@ -4209,12 +4994,17 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, char *hostkeydata, *sigdata, *keystr, *fingerprint; int hostkeylen, siglen; void *hkey; /* actual host key */ - unsigned char exchange_hash[20]; + unsigned char exchange_hash[32]; + 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 got_session_id, activated_authconn; struct Packet *pktout; + int dlgret; + int guessok; + int ignorepkt; }; crState(do_ssh2_transport_state); @@ -4224,11 +5014,49 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, 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; + /* + * 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_ctx &= ~SSH2_PKTCTX_KEX_MASK; { - int i; + int i, j, 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 (ssh->cfg.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 CIPHER_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) */ @@ -4249,6 +5077,9 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, 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. */ @@ -4258,27 +5089,14 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, break; } } - } - - /* - * Set up preferred compression. - */ - if (ssh->cfg.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); - begin_key_exchange: - { - int i, j, cipherstr_started; + /* + * Set up preferred compression. + */ + if (ssh->cfg.compression) + s->preferred_comp = &ssh_zlib; + else + s->preferred_comp = &ssh_comp_none; /* * Enable queueing of outgoing auth- or connection-layer @@ -4287,6 +5105,11 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, ssh->queueing = TRUE; /* + * Flag that KEX is in progress. + */ + ssh->kex_in_progress = TRUE; + + /* * Construct and send our key exchange packet. */ s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT); @@ -4294,13 +5117,16 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte()); /* List key exchange algorithms. */ ssh2_pkt_addstring_start(s->pktout); - 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(s->pktout, kex_algs[i]->name); - if (i < lenof(kex_algs) - 1) - ssh2_pkt_addstring_str(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(s->pktout); @@ -4311,28 +5137,28 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } /* List client->server encryption algorithms. */ ssh2_pkt_addstring_start(s->pktout); - cipherstr_started = 0; + 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 (cipherstr_started) + if (commalist_started) ssh2_pkt_addstring_str(s->pktout, ","); ssh2_pkt_addstring_str(s->pktout, c->list[j]->name); - cipherstr_started = 1; + commalist_started = 1; } } /* List server->client encryption algorithms. */ ssh2_pkt_addstring_start(s->pktout); - cipherstr_started = 0; + 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 (cipherstr_started) + if (commalist_started) ssh2_pkt_addstring_str(s->pktout, ","); ssh2_pkt_addstring_str(s->pktout, c->list[j]->name); - cipherstr_started = 1; + commalist_started = 1; } } /* List client->server MAC algorithms. */ @@ -4381,22 +5207,21 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_adduint32(s->pktout, 0); } - ssh->exhash = ssh->exhashbase; - sha_string(&ssh->exhash, s->pktout->data + 5, s->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_noqueue(ssh, s->pktout); if (!pktin) crWaitUntil(pktin); - if (pktin->length > 5) - sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5); /* * Now examine the other side's KEXINIT to see what we're up * to. */ { - char *str; + char *str, *preferred; int i, j, len; if (pktin->type != SSH2_MSG_KEXINIT) { @@ -4411,17 +5236,39 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, s->scmac_tobe = NULL; s->cscomp_tobe = NULL; s->sccomp_tobe = NULL; + 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 */ - 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; + + 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)")); + crStop(0); } + /* + * 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)) { @@ -4429,12 +5276,13 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, break; } } + s->guessok = s->guessok && + first_in_commasep_string(hostkey_algs[0]->name, str, len); ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */ - s->warn = 0; 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)) { @@ -4443,11 +5291,8 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } } } - 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)", @@ -4456,11 +5301,10 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */ - s->warn = 0; 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)) { @@ -4469,11 +5313,8 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } } } - 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)", @@ -4513,6 +5354,96 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, break; } } + 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; + + 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 { + 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 kex warning", NULL, + 0, TRUE); + crStop(0); + } + } + + 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 { + 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); + } + } + + 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 { + 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); + } + } + + 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->ignorepkt) /* first_kex_packet_follows */ + crWaitUntil(pktin); /* Ignore packet */ } /* @@ -4527,16 +5458,16 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, scbits = s->sccipher_tobe->keylen; s->nbits = (csbits > scbits ? csbits : scbits); } - /* 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; + /* 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 == &ssh_diffiehellman_gex) { + if (!ssh->kex->pdata) { logevent("Doing Diffie-Hellman group exchange"); ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX; /* @@ -4559,30 +5490,35 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, bombout(("unable to read mp-ints from incoming group packet")); crStop(0); } - ssh->kex_ctx = dh_setup_group(s->p, s->g); + 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_ctx |= SSH2_PKTCTX_DHGROUP1; - ssh->kex_ctx = dh_setup_group1(); + ssh->pkt_ctx |= 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); } logevent("Doing Diffie-Hellman key exchange"); /* * 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 */ crWaitUntil(pktin); if (pktin->type != s->kex_reply_value) { bombout(("expected key exchange reply packet from server")); crStop(0); } + set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */ ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); s->f = ssh2_pkt_getmp(pktin); if (!s->f) { @@ -4593,55 +5529,137 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, s->K = dh_find_K(ssh->kex_ctx, s->f); - 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); + /* 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); } - 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); + hash_mpint(ssh->kex->hash, ssh->exhash, s->e); + hash_mpint(ssh->kex->hash, ssh->exhash, s->f); + 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); dh_cleanup(ssh->kex_ctx); ssh->kex_ctx = NULL; #if 0 debug(("Exchange hash is:\n")); - dmemdump(s->exchange_hash, 20); + dmemdump(s->exchange_hash, ssh->kex->hash->hlen); #endif 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)) { + (char *)s->exchange_hash, + ssh->kex->hash->hlen)) { bombout(("Server's host key did not match the signature supplied")); crStop(0); } /* - * Authenticate remote host: verify host key. (We've already - * checked the signature of the exchange hash.) + * 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 { + 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); + } + 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. */ - 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); + { + unsigned char keyspace[40]; + ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace); + ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace); + ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace); + ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); } - sfree(s->fingerprint); - sfree(s->keystr); - ssh->hostkey->freekey(s->hkey); - /* - * Send SSH2_MSG_NEWKEYS. - */ - s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS); - ssh2_pkt_send_noqueue(ssh, s->pktout); + 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 @@ -4658,84 +5676,79 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, bombout(("expected new-keys packet from server")); crStop(0); } + ssh->incoming_data_size = 0; /* start counting from here */ /* - * Create and initialise session keys. + * We've seen server NEWKEYS, so create and initialise + * server-to-client 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->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->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->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->cs_comp_ctx) - ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); - ssh->cscomp = s->cscomp_tobe; - ssh->cs_comp_ctx = ssh->cscomp->compress_init(); - 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(); /* - * Set IVs after keys. Here we use the exchange hash from the - * _first_ key exchange. + * Set IVs on server-to-client keys. Here we use the exchange + * hash from the _first_ key exchange. */ { 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); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'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); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'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); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace); ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); } - logeventf(ssh, "Initialised %.200s client->server encryption", - ssh->cscipher->text_name); logeventf(ssh, "Initialised %.200s server->client encryption", ssh->sccipher->text_name); - logeventf(ssh, "Initialised %.200s client->server MAC algorithm", - ssh->csmac->text_name); logeventf(ssh, "Initialised %.200s server->client MAC algorithm", ssh->scmac->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); + + /* + * Free key exchange data. + */ freebn(s->f); freebn(s->K); - if (ssh->kex == &ssh_diffiehellman_gex) { + if (!ssh->kex->pdata) { freebn(s->g); freebn(s->p); } /* + * 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 (ssh->cfg.ssh_rekey_time != 0) + ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC, + ssh2_timer, ssh); + + /* * 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 @@ -4743,28 +5756,60 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because * it would only confuse the layer above. */ - if (!s->first_kex) { - crReturn(1); + if (s->activated_authconn) { + crReturn(0); } - s->first_kex = 0; + s->activated_authconn = TRUE; /* * 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==-1, because this is a special signal meaning + * `initiate client-driven rekey', and `in' contains a message + * giving the reason for the rekey. */ - while (!(pktin && pktin->type == SSH2_MSG_KEXINIT)) { + while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) || + (!pktin && inlen == -1))) { + wait_for_rekey: crReturn(1); } - logevent("Server initiated key re-exchange"); + if (pktin) { + logevent("Server initiated key re-exchange"); + } else { + /* + * 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 (ssh->cfg.ssh_rekey_time != 0) { + ssh->next_rekey = + schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC, + ssh2_timer, ssh); + } + goto wait_for_rekey; /* this is utterly horrid */ + } else { + logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in); + } + } goto begin_key_exchange; crFinish(1); } /* - * Add data to an SSH2 channel output buffer. + * Add data to an SSH-2 channel output buffer. */ static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) @@ -4773,7 +5818,7 @@ static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, } /* - * Attempt to send data on an SSH2 channel. + * Attempt to send data on an SSH-2 channel. */ static int ssh2_try_send(struct ssh_channel *c) { @@ -4806,8 +5851,34 @@ static int ssh2_try_send(struct ssh_channel *c) return bufchain_size(&c->v.v2.outbuffer); } +static void ssh2_try_send_and_unthrottle(struct ssh_channel *c) +{ + int bufsize; + if (c->closes) + return; /* 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; + } + } +} + /* - * Potentially enlarge the window on an SSH2 channel. + * Potentially enlarge the window on an SSH-2 channel. */ static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) { @@ -4821,28 +5892,573 @@ static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) if (c->closes != 0) return; - if (newwin > c->v.v2.locwindow) { + /* + * 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 > c->v.v2.locwindow * 2) { struct Packet *pktout; 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_adduint32(pktout, newwin - c->v.v2.locwindow); + ssh2_pkt_send(ssh, pktout); + c->v.v2.locwindow = newwin; + } +} + +static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) +{ + unsigned i = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + c = find234(ssh->channels, &i, ssh_channelfind); + if (c && !c->closes) { + c->v.v2.remwindow += ssh_pkt_getuint32(pktin); + ssh2_try_send_and_unthrottle(c); + } +} + +static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) +{ + char *data; + int length; + unsigned i = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + c = find234(ssh->channels, &i, ssh_channelfind); + if (!c) + return; /* nonexistent channel */ + 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; + 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, 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, + 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); + } +} + +static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin) +{ + unsigned i = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + + c = find234(ssh->channels, &i, ssh_channelfind); + if (!c) + return; /* 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); + } +} + +static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) +{ + unsigned i = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + struct Packet *pktout; + + c = find234(ssh->channels, &i, ssh_channelfind); + if (!c || c->halfopen) { + bombout(("Received CHANNEL_CLOSE for %s channel %d\n", + c ? "half-open" : "nonexistent", i)); + return; + } + /* Do pre-close processing on the channel. */ + 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); + 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) { + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + } + del234(ssh->channels, c); + bufchain_clear(&c->v.v2.outbuffer); + 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->cfg.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_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) +{ + unsigned i = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + struct Packet *pktout; + + c = find234(ssh->channels, &i, ssh_channelfind); + if (!c) + return; /* nonexistent channel */ + 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->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. + */ + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + } +} + +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 i = ssh_pkt_getuint32(pktin); + unsigned reason_code; + char *reason_string; + int reason_length; + struct ssh_channel *c; + c = find234(ssh->channels, &i, ssh_channelfind); + if (!c) + return; /* nonexistent channel */ + if (c->type != CHAN_SOCKDATA_DORMANT) + return; /* dunno why they're failing this */ + + 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); + + pfd_close(c->u.pfd.s); + + del234(ssh->channels, c); + sfree(c); +} + +static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) +{ + unsigned localid; + char *type; + int typelen, want_reply; + int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */ + struct ssh_channel *c; + struct Packet *pktout; + + localid = ssh_pkt_getuint32(pktin); + ssh_pkt_getstring(pktin, &type, &typelen); + want_reply = ssh2_pkt_getbool(pktin); + + /* + * 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 = dupprintf("Received channel request for nonexistent" + " channel %d", localid); + ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); + sfree(buf); + return; + } + + /* + * Having got the channel number, we now look at + * the request type string to see if it's something + * we recognise. + */ + 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 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 { \ + long q = offset; \ + if (q >= 0 && q+4 <= len) { \ + q = q + 4 + GET_32BIT(p+q); \ + if (q >= 0 && q+4 <= len && \ + ((q = 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; + } + } + if (is_plausible) { + if (is_int) { + /* Old non-standard OpenSSH. */ + int signum = ssh_pkt_getuint32(pktin); + fmt_sig = dupprintf(" %d", signum); + } else { + /* As per the drafts. */ + 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); + } + } + 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; + } + 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); + + /* + * 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) { + pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE); + ssh2_pkt_send(ssh, pktout); + } +} + +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; + + 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 (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 { + 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->cfg, + 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; + } + } else { + error = "Unsupported channel type requested"; + } + + 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 { + 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); + 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); - c->v.v2.locwindow = newwin; } } -void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) +/* + * Buffer banner messages for later display at some convenient point. + */ +static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin) { - unsigned i = ssh_pkt_getuint32(pktin); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (c && !c->closes) - c->v.v2.remwindow += ssh_pkt_getuint32(pktin); + /* Arbitrary limit to prevent unbounded inflation of buffer */ + if (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); + } +} + +/* 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); } /* - * 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, struct Packet *pktin) @@ -4862,9 +6478,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, 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 tried_pubkey_config, tried_agent; + int kbd_inter_running, kbd_inter_refused; int we_are_in; int num_prompts, curr_prompt, echo; char username[100]; @@ -4889,16 +6506,33 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, crBegin(ssh->do_ssh2_authconn_crstate); - /* - * 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) { - bombout(("Server refused user authentication protocol")); - crStopV; + s->done_service_req = FALSE; + s->we_are_in = FALSE; + if (!ssh->cfg.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; + } } /* @@ -4927,7 +6561,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ s->username[0] = '\0'; s->got_username = FALSE; - do { + bufchain_init(&ssh->banner); + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = + ssh2_msg_userauth_banner; + while (!s->we_are_in) { /* * Get a username. */ @@ -4945,8 +6582,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * get_line failed to get a username. * Terminate. */ - logevent("No username provided. Abandoning session."); - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); crStopV; } } else { @@ -4993,8 +6629,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->tried_pubkey_config = FALSE; s->tried_agent = FALSE; - s->tried_keyb_inter = FALSE; s->kbd_inter_running = FALSE; + s->kbd_inter_refused = 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; @@ -5026,9 +6662,14 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ if (!s->gotit) crWaitUntilV(pktin); - while (pktin->type == SSH2_MSG_USERAUTH_BANNER) { - char *banner; - int size; + /* + * 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 @@ -5037,12 +6678,13 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * the banner will screw up processing on the * output of (say) plink.) */ - if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) { - ssh_pkt_getstring(pktin, &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(pktin); + bufchain_clear(&ssh->banner); } if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) { logevent("Access granted"); @@ -5061,6 +6703,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ if (!s->gotit) s->curr_prompt = 0; + } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) { + /* FIXME: perhaps we should support this? */ + bombout(("PASSWD_CHANGEREQ not yet supported")); + crStopV; } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) { bombout(("Strange packet received during authentication: type %d", pktin->type)); @@ -5184,19 +6830,11 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, 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); - } + logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); 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); - } + logeventf(ssh, "Trying Pageant key #%d", s->keyi); s->pklen = GET_32BIT(s->p); s->p += 4; if (s->publickey_blob && @@ -5252,7 +6890,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_addstring_start(s->pktout); ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); - s->siglen = s->pktout->length - 5 + 4 + 20; + 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 */ @@ -5271,11 +6910,12 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->q += 4; /* Now the data to be signed... */ if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { - PUT_32BIT(s->q, 20); + PUT_32BIT(s->q, ssh->v2_session_id_len); s->q += 4; } - memcpy(s->q, ssh->v2_session_id, 20); - s->q += 20; + 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; @@ -5385,10 +7025,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } } - if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) { + if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused && + !s->kbd_inter_running) { 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; @@ -5407,9 +7047,11 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->gotit = TRUE; logevent("Keyboard-interactive authentication refused"); s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; + s->kbd_inter_refused = TRUE; /* don't try it again */ continue; } + c_write_str(ssh, "Using keyboard-interactive authentication.\r\n"); s->kbd_inter_running = TRUE; s->curr_prompt = 0; } @@ -5417,7 +7059,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, if (s->kbd_inter_running) { 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; @@ -5494,16 +7135,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * command line which has already failed to * work). Terminate. */ - s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(s->pktout, "No more passwords available" - " to try"); - ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ - ssh2_pkt_send_noqueue(ssh, s->pktout); - logevent("Unable to authenticate"); - connection_fatal(ssh->frontend, - "Unable to authenticate"); - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + FALSE); crStopV; } } else { @@ -5577,16 +7211,19 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * followed by everything so far placed in the * outgoing packet. */ - sigdata_len = s->pktout->length - 5 + 4 + 20; + 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, 20); + PUT_32BIT(sigdata+p, ssh->v2_session_id_len); p += 4; } - memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20; + 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; @@ -5605,20 +7242,16 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } } 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. + * 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! */ s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + s->pktout->forcepad = 256; ssh2_pkt_addstring(s->pktout, s->username); ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */ ssh2_pkt_addstring(s->pktout, "password"); @@ -5627,46 +7260,13 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_addstring(s->pktout, s->password); memset(s->password, 0, sizeof(s->password)); end_log_omission(ssh, s->pktout); - ssh2_pkt_defer(ssh, s->pktout); - /* - * 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. - */ - if (ssh->cscipher) { - 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); - } - s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE); - ssh2_pkt_addstring_start(s->pktout); - for (i = 0; i < stringlen; i++) { - char c = (char) random_byte(); - ssh2_pkt_addstring_data(s->pktout, &c, 1); - } - ssh2_pkt_defer(ssh, s->pktout); - } - ssh_pkt_defersend(ssh); + ssh2_pkt_send(ssh, s->pktout); logevent("Sent password"); s->type = AUTH_TYPE_PASSWORD; } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) { if (s->curr_prompt == 0) { s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); + s->pktout->forcepad = 256; ssh2_pkt_adduint32(s->pktout, s->num_prompts); } if (s->need_pw) { /* only add pw if we just got one! */ @@ -5691,26 +7291,18 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; } else { - c_write_str(ssh, "No supported authentication methods" - " left to try!\r\n"); - logevent("No supported authentications offered." - " Disconnecting"); - s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(s->pktout, "No supported authentication" - " methods available"); - ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ - ssh2_pkt_send_noqueue(ssh, s->pktout); - ssh_closing((Plug)ssh, NULL, 0, 0); + ssh_disconnect(ssh, NULL, + "No supported authentication methods available", + SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE, + FALSE); 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. + * Now the connection protocol has started, one way or another. */ ssh->channels = newtree234(ssh_channelcmp); @@ -5721,6 +7313,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_channel_window_adjust; + ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = + ssh2_msg_global_request; /* * Create the main session channel. @@ -5734,7 +7328,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid); ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE; ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */ - ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */ + ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */ ssh2_pkt_send(ssh, s->pktout); crWaitUntilV(pktin); if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { @@ -5747,6 +7341,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, crStopV; } ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin); + ssh->mainchan->halfopen = FALSE; ssh->mainchan->type = CHAN_MAINSESSION; ssh->mainchan->closes = 0; ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); @@ -5759,6 +7354,24 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh->mainchan = NULL; /* + * Now we have a channel, make dispatch table entries for + * general channel-based messages. + */ + 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; + + /* * Potentially enable X11 forwarding. */ if (ssh->mainchan && ssh->cfg.x11_forward) { @@ -5773,7 +7386,16 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_addbool(s->pktout, 1); /* want reply */ ssh2_pkt_addbool(s->pktout, 0); /* many connections */ ssh2_pkt_addstring(s->pktout, proto); + /* + * 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. + */ + dont_log_password(ssh, s->pktout, PKTLOG_BLANK); ssh2_pkt_addstring(s->pktout, data); + end_log_omission(ssh, s->pktout); ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display)); ssh2_pkt_send(ssh, s->pktout); @@ -5795,163 +7417,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* * Enable port forwardings. */ - { - 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; - ssh->portfwd_strptr++; /* eat the NUL and move to next one */ - } - 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) { - /* Set up a description of the source port. */ - static char *sportdesc; - sportdesc = dupprintf("%.*s%.*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, ")"); - if (type == 'L') { - /* Verbose description of the destination port */ - char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s", - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - const char *err = pfd_addforward(host, dport, - *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - if (err) { - logeventf(ssh, "Local port %s forward to %s" - " failed: %s", sportdesc, dportdesc, err); - } else { - logeventf(ssh, "Local port %s forwarding to %s", - sportdesc, dportdesc); - } - sfree(dportdesc); - } else if (type == 'D') { - const char *err = pfd_addforward(NULL, -1, - *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - if (err) { - logeventf(ssh, "Local port %s SOCKS dynamic forward" - " setup failed: %s", sportdesc, err); - } else { - logeventf(ssh, "Local port %s doing SOCKS" - " dynamic forwarding", sportdesc); - } - } 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" - " forward to %s:%.*s%.*s%d%.*s", - sportdesc, - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - s->pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); - ssh2_pkt_addstring(s->pktout, "tcpip-forward"); - ssh2_pkt_addbool(s->pktout, 1);/* want reply */ - if (*saddr) { - ssh2_pkt_addstring(s->pktout, saddr); - } else if (ssh->cfg.rport_acceptall) { - ssh2_pkt_addstring(s->pktout, "0.0.0.0"); - } else { - ssh2_pkt_addstring(s->pktout, "127.0.0.1"); - } - ssh2_pkt_adduint32(s->pktout, sport); - ssh2_pkt_send(ssh, s->pktout); - - crWaitUntilV(pktin); - - if (pktin->type != SSH2_MSG_REQUEST_SUCCESS) { - if (pktin->type != SSH2_MSG_REQUEST_FAILURE) { - bombout(("Unexpected response to port " - "forwarding request: packet type %d", - pktin->type)); - crStopV; - } - logevent("Server refused this port forwarding"); - } else { - logevent("Remote port forwarding enabled"); - } - } - } - sfree(sportdesc); - } - } - } + ssh_setup_portfwd(ssh, &ssh->cfg); /* * Potentially enable agent forwarding. @@ -5998,9 +7464,11 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */ ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */ ssh2_pkt_addstring_start(s->pktout); - ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */ + parse_ttymodes(ssh, ssh->cfg.ttymodes, + ssh2_send_ttymode, (void *)s->pktout); + ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED); ssh2_pkt_adduint32(s->pktout, ssh->ispeed); - ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */ + ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED); ssh2_pkt_adduint32(s->pktout, ssh->ospeed); ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */ ssh2_pkt_send(ssh, s->pktout); @@ -6105,6 +7573,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } else { subsys = ssh->cfg.ssh_subsys; cmd = ssh->cfg.remote_cmd_ptr; + if (!cmd) cmd = ssh->cfg.remote_cmd; } s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); @@ -6167,499 +7636,15 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, crReturnV; s->try_send = FALSE; if (pktin) { - if (pktin->type == SSH2_MSG_CHANNEL_DATA || - pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { - char *data; - int length; - unsigned i = ssh_pkt_getuint32(pktin); - struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c) - continue; /* nonexistent channel */ - if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA && - ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR) - continue; /* extended but not stderr */ - ssh_pkt_getstring(pktin, &data, &length); - if (data) { - int bufsize = 0; - c->v.v2.locwindow -= 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) { - 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 (pktin->type == SSH2_MSG_CHANNEL_EOF) { - unsigned i = ssh_pkt_getuint32(pktin); - 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 (pktin->type == SSH2_MSG_CHANNEL_CLOSE) { - unsigned i = ssh_pkt_getuint32(pktin); - 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: - ssh->mainchan = NULL; - update_specials_menu(ssh->frontend); - break; - 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) { - s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); - ssh2_pkt_adduint32(s->pktout, c->remoteid); - ssh2_pkt_send(ssh, s->pktout); - } - del234(ssh->channels, c); - bufchain_clear(&c->v.v2.outbuffer); - 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->cfg.ssh_no_shell && 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. - */ - s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(s->pktout, "All open channels closed"); - ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ - ssh2_pkt_send_noqueue(ssh, s->pktout); -#endif - ssh_closing((Plug)ssh, NULL, 0, 0); - crStopV; - } - continue; /* remote sends close; ignore (FIXME) */ - } else if (pktin->type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { - unsigned i = ssh_pkt_getuint32(pktin); - 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 = ssh_pkt_getuint32(pktin); - 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->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. - */ - s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); - ssh2_pkt_adduint32(s->pktout, c->remoteid); - ssh2_pkt_send(ssh, s->pktout); - } - } else if (pktin->type == SSH2_MSG_CHANNEL_OPEN_FAILURE) { - static const char *const reasons[] = { - "", - "Administratively prohibited", - "Connect failed", - "Unknown channel type", - "Resource shortage", - }; - unsigned i = ssh_pkt_getuint32(pktin); - unsigned reason_code; - char *reason_string; - int reason_length; - char *message; - 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 */ - - 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); - message = dupprintf("Forwarded connection refused by" - " server: %s [%.*s]", reasons[reason_code], - reason_length, reason_string); - logevent(message); - sfree(message); - - pfd_close(c->u.pfd.s); - - del234(ssh->channels, c); - sfree(c); - } else if (pktin->type == SSH2_MSG_CHANNEL_REQUEST) { - unsigned localid; - char *type; - int typelen, want_reply; - int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */ - struct ssh_channel *c; - - localid = ssh_pkt_getuint32(pktin); - ssh_pkt_getstring(pktin, &type, &typelen); - want_reply = ssh2_pkt_getbool(pktin); - - /* - * 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); - s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring(s->pktout, buf); - ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ - ssh2_pkt_send_noqueue(ssh, s->pktout); - 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 (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 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 { \ - long q = offset; \ - if (q >= 0 && q+4 <= len) { \ - q = q + 4 + GET_32BIT(p+q); \ - if (q >= 0 && q+4 <= len && \ - (q = q + 4 + GET_32BIT(p+q)) && 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; - } - } - if (is_plausible) { - if (is_int) { - /* Old non-standard OpenSSH. */ - int signum = ssh_pkt_getuint32(pktin); - fmt_sig = dupprintf(" %d", signum); - } else { - /* As per the drafts. */ - 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); - } - } - 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; - } - if (want_reply) { - s->pktout = ssh2_pkt_init(reply); - ssh2_pkt_adduint32(s->pktout, c->remoteid); - ssh2_pkt_send(ssh, s->pktout); - } - } else if (pktin->type == SSH2_MSG_GLOBAL_REQUEST) { - char *type; - int typelen, want_reply; - - ssh_pkt_getstring(pktin, &type, &typelen); - want_reply = ssh2_pkt_getbool(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) { - s->pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE); - ssh2_pkt_send(ssh, s->pktout); - } - } else if (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; - 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; - - 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 (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 { - 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->cfg); - 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", 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) { - s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); - ssh2_pkt_adduint32(s->pktout, c->remoteid); - ssh2_pkt_adduint32(s->pktout, SSH2_OPEN_CONNECT_FAILED); - ssh2_pkt_addstring(s->pktout, error); - ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ - ssh2_pkt_send(ssh, s->pktout); - logeventf(ssh, "Rejected channel open: %s", error); - 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); - s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); - ssh2_pkt_adduint32(s->pktout, c->remoteid); - ssh2_pkt_adduint32(s->pktout, c->localid); - ssh2_pkt_adduint32(s->pktout, c->v.v2.locwindow); - ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */ - ssh2_pkt_send(ssh, s->pktout); - } - } else { - bombout(("Strange packet received: type %d", pktin->type)); - crStopV; - } + bombout(("Strange packet received: type %d", pktin->type)); + crStopV; } else if (ssh->mainchan) { /* * We have spare data. Add it to the channel buffer. @@ -6673,30 +7658,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* * 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(c); } } @@ -6704,9 +7667,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } /* - * Handlers for SSH2 messages that might arrive at any moment. + * Handlers for SSH-2 messages that might arrive at any moment. */ -void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) +static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) { /* log reason code in disconnect message */ char *buf, *msg; @@ -6735,10 +7698,10 @@ void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) sfree(buf); } -void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) +static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) { /* log the debug message */ - char *buf, *msg; + char *msg; int msglen; int always_display; @@ -6746,12 +7709,10 @@ void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) always_display = ssh2_pkt_getbool(pktin); ssh_pkt_getstring(pktin, &msg, &msglen); - buf = dupprintf("Remote debug message: %.*s", msglen, msg); - logevent(buf); - sfree(buf); + logeventf(ssh, "Remote debug message: %.*s", msglen, msg); } -void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) +static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) { struct Packet *pktout; pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED); @@ -6764,7 +7725,7 @@ void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) } /* - * Handle the top-level SSH2 protocol. + * Handle the top-level SSH-2 protocol. */ static void ssh2_protocol_setup(Ssh ssh) { @@ -6818,16 +7779,38 @@ static void ssh2_protocol_setup(Ssh ssh) * These special message types we install handlers for. */ ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect; - ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */ + 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_protocol(Ssh ssh, unsigned char *in, int inlen, +static void ssh2_timer(void *ctx, long now) +{ + Ssh ssh = (Ssh)ctx; + + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 && + now - ssh->next_rekey >= 0) { + do_ssh2_transport(ssh, "timeout", -1, NULL); + } +} + +static void ssh2_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->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->packet_dispatch[pktin->type](ssh, pktin); return; @@ -6884,6 +7867,8 @@ 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; @@ -6909,12 +7894,18 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, 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; *backend_handle = ssh; @@ -6929,6 +7920,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->channels = NULL; ssh->rportfwds = NULL; + ssh->portfwds = NULL; ssh->send_ok = 0; ssh->editing = 0; @@ -6943,10 +7935,17 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->pinger = NULL; + ssh->incoming_data_size = ssh->outgoing_data_size = + ssh->deferred_data_size = 0L; + ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data); + ssh->kex_in_progress = FALSE; + p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive); if (p != NULL) return p; + random_ref(); + return NULL; } @@ -6986,6 +7985,13 @@ static void ssh_free(void *handle) ssh_free_packet(ssh->queue[ssh->queuelen]); sfree(ssh->queue); + while (ssh->qhead) { + struct queued_handler *qh = ssh->qhead; + ssh->qhead = qh->next; + sfree(ssh->qhead); + } + ssh->qhead = ssh->qtail = NULL; + if (ssh->channels) { while ((c = delpos234(ssh->channels, 0)) != NULL) { switch (c->type) { @@ -7001,12 +8007,14 @@ static void ssh_free(void *handle) sfree(c); } freetree234(ssh->channels); + ssh->channels = NULL; } if (ssh->rportfwds) { while ((pf = delpos234(ssh->rportfwds, 0)) != NULL) sfree(pf); freetree234(ssh->rportfwds); + ssh->rportfwds = NULL; } sfree(ssh->deferred_send_data); if (ssh->x11auth) @@ -7015,35 +8023,82 @@ static void ssh_free(void *handle) 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); if (ssh->crcda_ctx) { crcda_free_context(ssh->crcda_ctx); ssh->crcda_ctx = NULL; } if (ssh->s) - ssh_do_close(ssh); - sfree(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); + + 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) { Ssh ssh = (Ssh) handle; + char *rekeying = NULL, rekey_mandatory = FALSE; + unsigned long old_max_data_size; + pinger_reconfig(ssh->pinger, &ssh->cfg, cfg); + if (ssh->portfwds) + ssh_setup_portfwd(ssh, cfg); + + if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time && + cfg->ssh_rekey_time != 0) { + long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC; + long now = GETTICKCOUNT(); + + if (new_next - now < 0) { + 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(cfg->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 (ssh->cfg.compression != cfg->compression) { + rekeying = "compression setting changed"; + rekey_mandatory = TRUE; + } + + if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc || + memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist, + sizeof(ssh->cfg.ssh_cipherlist))) { + rekeying = "cipher settings changed"; + rekey_mandatory = TRUE; + } + ssh->cfg = *cfg; /* STRUCTURE COPY */ + + 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) { @@ -7137,13 +8192,17 @@ 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 ignore_special[] = { + static const struct telnet_special ssh1_ignore_special[] = { + {"IGNORE message", TS_NOP} + }; + static const struct telnet_special ssh2_transport_specials[] = { {"IGNORE message", TS_NOP}, + {"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 draft-ietf-secsh-connect-19. + /* These are the signal names defined by draft-ietf-secsh-connect-23. * They include all the ISO C signals, but are a subset of the POSIX * required signals. */ {"SIGINT (Interrupt)", TS_SIGINT}, @@ -7161,7 +8220,8 @@ static const struct telnet_special *ssh_get_specials(void *handle) static const struct telnet_special specials_end[] = { {NULL, TS_EXITMENU} }; - static struct telnet_special ssh_specials[lenof(ignore_special) + + /* XXX review this length for any changes: */ + static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) + lenof(ssh2_session_specials) + lenof(specials_end)]; Ssh ssh = (Ssh) handle; @@ -7178,10 +8238,9 @@ static const struct telnet_special *ssh_get_specials(void *handle) * 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(ignore_special); + ADD_SPECIALS(ssh1_ignore_special); } else if (ssh->version == 2) { - /* XXX add rekey, when implemented */ - ADD_SPECIALS(ignore_special); + ADD_SPECIALS(ssh2_transport_specials); if (ssh->mainchan) ADD_SPECIALS(ssh2_session_specials); } /* else we're not ready yet */ @@ -7196,7 +8255,7 @@ static const struct telnet_special *ssh_get_specials(void *handle) } /* - * 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'). */ @@ -7221,6 +8280,7 @@ static void ssh_special(void *handle, Telnet_Special code) struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); ssh2_pkt_send(ssh, pktout); + ssh->send_ok = 0; /* now stop trying to read from stdin */ } logevent("Sent EOF message"); } else if (code == TS_PING || code == TS_NOP) { @@ -7234,11 +8294,15 @@ static void ssh_special(void *handle, Telnet_Special code) 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"); + logevent("Unable to send BREAK signal in SSH-1"); } else if (ssh->mainchan) { pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); @@ -7290,7 +8354,7 @@ void *new_sock_channel(void *handle, Socket s) c->ssh = ssh; if (c) { - c->remoteid = -1; /* to be set when open confirmed */ + c->halfopen = TRUE; c->localid = alloc_channel_id(ssh); c->closes = 0; c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ @@ -7332,7 +8396,7 @@ void ssh_send_port_open(void *channel, char *hostname, int port, char *org) PKT_INT, c->localid, PKT_STR, hostname, PKT_INT, port, - //PKT_STR, , + /* PKT_STR, , */ PKT_END); } else { pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); @@ -7340,7 +8404,7 @@ void ssh_send_port_open(void *channel, char *hostname, int port, char *org) ssh2_pkt_adduint32(pktout, c->localid); c->v.v2.locwindow = OUR_V2_WINSIZE; ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */ - ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */ + ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ ssh2_pkt_addstring(pktout, hostname); ssh2_pkt_adduint32(pktout, port); /* @@ -7399,6 +8463,16 @@ static int ssh_return_exitcode(void *handle) } /* + * 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; +} + +/* * Gross hack: pscp will try to start SFTP but fall back to scp1 if * that fails. This variable is the means by which scp.c can reach * into the SSH code and find out which one it got. @@ -7425,5 +8499,6 @@ Backend ssh_backend = { ssh_provide_ldisc, ssh_provide_logctx, ssh_unthrottle, + ssh_cfg_info, 22 };