X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/e557416818242c2e8b14ec03d321740fd83619e4..7e78000d8966255e919e3d8753fd784f4559ee55:/ssh.c diff --git a/ssh.c b/ssh.c index ae41a80e..3af4ba94 100644 --- a/ssh.c +++ b/ssh.c @@ -1,12 +1,12 @@ +#include #include #include #include #include -#include #include "putty.h" +#include "tree234.h" #include "ssh.h" -#include "scp.h" #ifndef FALSE #define FALSE 0 @@ -16,44 +16,117 @@ #endif #define logevent(s) { logevent(s); \ - if (IS_SCP && (scp_flags & SCP_VERBOSE) != 0) \ + if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ fprintf(stderr, "%s\n", s); } -#define SSH1_MSG_DISCONNECT 1 -#define SSH1_SMSG_PUBLIC_KEY 2 -#define SSH1_CMSG_SESSION_KEY 3 -#define SSH1_CMSG_USER 4 -#define SSH1_CMSG_AUTH_PASSWORD 9 -#define SSH1_CMSG_REQUEST_PTY 10 -#define SSH1_CMSG_WINDOW_SIZE 11 -#define SSH1_CMSG_EXEC_SHELL 12 -#define SSH1_CMSG_EXEC_CMD 13 -#define SSH1_SMSG_SUCCESS 14 -#define SSH1_SMSG_FAILURE 15 -#define SSH1_CMSG_STDIN_DATA 16 -#define SSH1_SMSG_STDOUT_DATA 17 -#define SSH1_SMSG_STDERR_DATA 18 -#define SSH1_CMSG_EOF 19 -#define SSH1_SMSG_EXIT_STATUS 20 -#define SSH1_CMSG_EXIT_CONFIRMATION 33 -#define SSH1_MSG_IGNORE 32 -#define SSH1_MSG_DEBUG 36 -#define SSH1_CMSG_AUTH_TIS 39 -#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 -#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 - -#define SSH1_AUTH_TIS 5 - -#define SSH2_MSG_DISCONNECT 1 -#define SSH2_MSG_IGNORE 2 -#define SSH2_MSG_UNIMPLEMENTED 3 -#define SSH2_MSG_DEBUG 4 -#define SSH2_MSG_SERVICE_REQUEST 5 -#define SSH2_MSG_SERVICE_ACCEPT 6 -#define SSH2_MSG_KEXINIT 20 -#define SSH2_MSG_NEWKEYS 21 -#define SSH2_MSG_KEXDH_INIT 30 -#define SSH2_MSG_KEXDH_REPLY 31 +#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \ + (s ? sk_close(s), s = NULL : 0), \ + connection_fatal msg ) + +#define SSH1_MSG_DISCONNECT 1 /* 0x1 */ +#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ +#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ +#define SSH1_CMSG_USER 4 /* 0x4 */ +#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ +#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ +#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ +#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ +#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ +#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ +#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ +#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ +#define SSH1_SMSG_SUCCESS 14 /* 0xe */ +#define SSH1_SMSG_FAILURE 15 /* 0xf */ +#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ +#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ +#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ +#define SSH1_CMSG_EOF 19 /* 0x13 */ +#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ +#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ +#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ +#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ +#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ +#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ +#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ +#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ +#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ +#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ +#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ +#define SSH1_MSG_IGNORE 32 /* 0x20 */ +#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ +#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ +#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ +#define SSH1_MSG_DEBUG 36 /* 0x24 */ +#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ +#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ +#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ +#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ +#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ +#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ +#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ + +#define SSH1_AUTH_TIS 5 /* 0x5 */ +#define SSH1_AUTH_CCARD 16 /* 0x10 */ + +#define SSH2_MSG_DISCONNECT 1 /* 0x1 */ +#define SSH2_MSG_IGNORE 2 /* 0x2 */ +#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ +#define SSH2_MSG_DEBUG 4 /* 0x4 */ +#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ +#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ +#define SSH2_MSG_KEXINIT 20 /* 0x14 */ +#define SSH2_MSG_NEWKEYS 21 /* 0x15 */ +#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ +#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ +#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ +#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ +#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ +#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ +#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ +#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ +#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ +#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ +#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ +#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ +#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ +#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ +#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ +#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ +#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ +#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ +#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ +#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ +#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ +#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ +#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ +#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ +#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ +#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ + +#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ +#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ +#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ +#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ +#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ +#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ +#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ +#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ +#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ +#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ +#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ + +#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ +#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ +#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ +#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ + +#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ + +/* + * Various remote-bug flags. + */ +#define BUG_CHOKES_ON_SSH1_IGNORE 1 +#define BUG_SSH2_HMAC 2 #define GET_32BIT(cp) \ (((unsigned long)(unsigned char)(cp)[0] << 24) | \ @@ -67,7 +140,7 @@ (cp)[2] = (unsigned char)((value) >> 8); \ (cp)[3] = (unsigned char)(value); } -enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR }; +enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; /* Coroutine mechanics for the sillier bits of the code */ #define crBegin1 static int crLine = 0; @@ -86,120 +159,198 @@ enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR }; #define crStop(z) do{ crLine = 0; return (z); }while(0) #define crStopV do{ crLine = 0; return; }while(0) #define crWaitUntil(c) do { crReturn(0); } while (!(c)) +#define crWaitUntilV(c) do { crReturnV; } while (!(c)) -extern struct ssh_cipher ssh_3des; -extern struct ssh_cipher ssh_des; -extern struct ssh_cipher ssh_blowfish; - -/* for ssh 2; we miss out single-DES because it isn't supported */ -struct ssh_cipher *ciphers[] = { &ssh_3des, &ssh_blowfish }; +extern char *x11_init (Socket *, char *, void *); +extern void x11_close (Socket); +extern void x11_send (Socket , char *, int); +extern void x11_invent_auth(char *, int, char *, int); -extern struct ssh_kex ssh_diffiehellman; -struct ssh_kex *kex_algs[] = { &ssh_diffiehellman }; - -extern struct ssh_hostkey ssh_dss; -struct ssh_hostkey *hostkey_algs[] = { &ssh_dss }; +/* + * Ciphers for SSH2. We miss out single-DES because it isn't + * supported; also 3DES and Blowfish are both done differently from + * SSH1. (3DES uses outer chaining; Blowfish has the opposite + * endianness and different-sized keys.) + */ +const static struct ssh2_ciphers *ciphers[] = { + &ssh2_aes, + &ssh2_blowfish, + &ssh2_3des, +}; -extern struct ssh_mac ssh_sha1; +const static struct ssh_kex *kex_algs[] = { + &ssh_diffiehellman_gex, + &ssh_diffiehellman }; -SHA_State exhash; +const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; -static void nullmac_sesskey(unsigned char *key, int len) { } +static void nullmac_key(unsigned char *key) { } static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { } static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; } -struct ssh_mac ssh_mac_none = { - nullmac_sesskey, nullmac_generate, nullmac_verify, "none", 0 +const static struct ssh_mac ssh_mac_none = { + nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 +}; +const static struct ssh_mac *macs[] = { + &ssh_sha1, &ssh_md5, &ssh_mac_none }; +const static struct ssh_mac *buggymacs[] = { + &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none }; + +static void ssh_comp_none_init(void) { } +static int ssh_comp_none_block(unsigned char *block, int len, + unsigned char **outblock, int *outlen) { + return 0; +} +static int ssh_comp_none_disable(void) { return 0; } +const static struct ssh_compress ssh_comp_none = { + "none", + ssh_comp_none_init, ssh_comp_none_block, + ssh_comp_none_init, ssh_comp_none_block, + ssh_comp_none_disable +}; +extern const struct ssh_compress ssh_zlib; +const static struct ssh_compress *compressions[] = { + &ssh_zlib, &ssh_comp_none }; + +enum { /* channel types */ + CHAN_MAINSESSION, + CHAN_X11, + CHAN_AGENT, +}; + +/* + * 2-3-4 tree storing channels. + */ +struct ssh_channel { + unsigned remoteid, localid; + int type; + int closes; + struct ssh2_data_channel { + unsigned char *outbuffer; + unsigned outbuflen, outbufsize; + unsigned remwindow, remmaxpkt; + } v2; + union { + struct ssh_agent_channel { + unsigned char *message; + unsigned char msglen[4]; + int lensofar, totallen; + } a; + struct ssh_x11_channel { + Socket s; + } x11; + } u; }; -struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none }; -struct ssh_compress ssh_comp_none = { - "none" +struct Packet { + long length; + int type; + unsigned char *data; + unsigned char *body; + long savedpos; + long maxlen; }; -struct ssh_compress *compressions[] = { &ssh_comp_none }; -static SOCKET s = INVALID_SOCKET; +static SHA_State exhash, exhashbase; + +static Socket s = NULL; static unsigned char session_key[32]; -static struct ssh_cipher *cipher = NULL; -static struct ssh_cipher *cscipher = NULL; -static struct ssh_cipher *sccipher = NULL; -static struct ssh_mac *csmac = NULL; -static struct ssh_mac *scmac = NULL; -static struct ssh_compress *cscomp = NULL; -static struct ssh_compress *sccomp = NULL; -static struct ssh_kex *kex = NULL; -static struct ssh_hostkey *hostkey = NULL; -int scp_flags = 0; -int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL; +static int ssh1_compressing; +static int ssh_agentfwd_enabled; +static int ssh_X11_fwd_enabled; +static int ssh_remote_bugs; +static const struct ssh_cipher *cipher = NULL; +static const struct ssh2_cipher *cscipher = NULL; +static const struct ssh2_cipher *sccipher = NULL; +static const struct ssh_mac *csmac = NULL; +static const struct ssh_mac *scmac = NULL; +static const struct ssh_compress *cscomp = NULL; +static const struct ssh_compress *sccomp = NULL; +static const struct ssh_kex *kex = NULL; +static const struct ssh_signkey *hostkey = NULL; +static unsigned char ssh2_session_id[20]; +int (*ssh_get_line)(const char *prompt, char *str, int maxlen, + int is_pw) = NULL; static char *savedhost; +static int savedport; +static int ssh_send_ok; +static int ssh_echoing, ssh_editing; + +static tree234 *ssh_channels; /* indexed by local id */ +static struct ssh_channel *mainchan; /* primary session channel */ static enum { + SSH_STATE_PREPACKET, SSH_STATE_BEFORE_SIZE, SSH_STATE_INTERMED, SSH_STATE_SESSION, SSH_STATE_CLOSED -} ssh_state = SSH_STATE_BEFORE_SIZE; - -static int size_needed = FALSE; - -static void s_write (char *buf, int len) { - while (len > 0) { - int i = send (s, buf, len, 0); - if (IS_SCP) { - noise_ultralight(i); - if (i <= 0) - fatalbox("Lost connection while sending"); - } - if (i > 0) - len -= i, buf += i; - } -} - -static int s_read (char *buf, int len) { - int ret = 0; - while (len > 0) { - int i = recv (s, buf, len, 0); - if (IS_SCP) - noise_ultralight(i); - if (i > 0) - len -= i, buf += i, ret += i; - else - return i; - } - return ret; -} - -static void c_write (char *buf, int len) { - if (IS_SCP) { - if (len > 0 && buf[len-1] == '\n') len--; - if (len > 0 && buf[len-1] == '\r') len--; - if (len > 0) { fwrite(buf, len, 1, stderr); fputc('\n', stderr); } - return; - } - while (len--) - c_write1(*buf++); -} +} ssh_state = SSH_STATE_PREPACKET; -struct Packet { - long length; - int type; - unsigned char *data; - unsigned char *body; - long savedpos; - long maxlen; -}; +static int size_needed = FALSE, eof_needed = FALSE; static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; +static unsigned char *deferred_send_data = NULL; +static int deferred_len = 0, deferred_size = 0; +static int ssh_version; static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt); static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); static void ssh_size(void); +static void ssh_special (Telnet_Special); +static void ssh2_try_send(struct ssh_channel *c); +static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); static int (*s_rdpkt)(unsigned char **data, int *datalen); +static struct rdpkt1_state_tag { + long len, pad, biglen, to_read; + unsigned long realcrc, gotcrc; + unsigned char *p; + int i; + int chunk; +} rdpkt1_state; + +static struct rdpkt2_state_tag { + long len, pad, payload, packetlen, maclen; + int i; + int cipherblk; + unsigned long incoming_sequence; +} rdpkt2_state; + +static int ssh_channelcmp(void *av, void *bv) { + struct ssh_channel *a = (struct ssh_channel *)av; + struct ssh_channel *b = (struct ssh_channel *)bv; + if (a->localid < b->localid) return -1; + if (a->localid > b->localid) return +1; + return 0; +} +static int ssh_channelfind(void *av, void *bv) { + unsigned *a = (unsigned *)av; + struct ssh_channel *b = (struct ssh_channel *)bv; + if (*a < b->localid) return -1; + if (*a > b->localid) return +1; + return 0; +} + +static void c_write (char *buf, int len) { + if ((flags & FLAG_STDERR)) { + int i; + for (i = 0; i < len; i++) + if (buf[i] != '\r') + fputc(buf[i], stderr); + return; + } + from_backend(1, buf, len); +} + +static void c_write_str (char *buf) { + c_write(buf, strlen(buf)); +} + /* * Collect incoming data in the incoming packet buffer. * Decipher and verify the packet when it is completely read. @@ -210,10 +361,7 @@ static int (*s_rdpkt)(unsigned char **data, int *datalen); */ static int ssh1_rdpkt(unsigned char **data, int *datalen) { - static long len, pad, biglen, to_read; - static unsigned long realcrc, gotcrc; - static unsigned char *p; - static int i; + struct rdpkt1_state_tag *st = &rdpkt1_state; crBegin; @@ -222,68 +370,110 @@ next_packet: pktin.type = 0; pktin.length = 0; - for (i = len = 0; i < 4; i++) { + for (st->i = st->len = 0; st->i < 4; st->i++) { while ((*datalen) == 0) - crReturn(4-i); - len = (len << 8) + **data; + crReturn(4-st->i); + st->len = (st->len << 8) + **data; (*data)++, (*datalen)--; } #ifdef FWHACK - if (len == 0x52656d6f) { /* "Remo"te server has closed ... */ - len = 0x300; /* big enough to carry to end */ + if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */ + st->len = 0x300; /* big enough to carry to end */ } #endif - pad = 8 - (len % 8); - biglen = len + pad; - pktin.length = len - 5; + st->pad = 8 - (st->len % 8); + st->biglen = st->len + st->pad; + pktin.length = st->len - 5; - if (pktin.maxlen < biglen) { - pktin.maxlen = biglen; - pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) : - realloc(pktin.data, biglen+APIEXTRA)); + if (pktin.maxlen < st->biglen) { + pktin.maxlen = st->biglen; + pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) : + srealloc(pktin.data, st->biglen+APIEXTRA)); if (!pktin.data) fatalbox("Out of memory"); } - to_read = biglen; - p = pktin.data; - while (to_read > 0) { - static int chunk; - chunk = to_read; + st->to_read = st->biglen; + st->p = pktin.data; + while (st->to_read > 0) { + st->chunk = st->to_read; while ((*datalen) == 0) - crReturn(to_read); - if (chunk > (*datalen)) - chunk = (*datalen); - memcpy(p, *data, chunk); - *data += chunk; - *datalen -= chunk; - p += chunk; - to_read -= chunk; + crReturn(st->to_read); + if (st->chunk > (*datalen)) + st->chunk = (*datalen); + memcpy(st->p, *data, st->chunk); + *data += st->chunk; + *datalen -= st->chunk; + st->p += st->chunk; + st->to_read -= st->chunk; } if (cipher) - cipher->decrypt(pktin.data, biglen); + cipher->decrypt(pktin.data, st->biglen); +#if 0 + debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); + for (st->i = 0; st->i < st->biglen; st->i++) + debug((" %02x", (unsigned char)pktin.data[st->i])); + debug(("\r\n")); +#endif + + st->realcrc = crc32(pktin.data, st->biglen-4); + st->gotcrc = GET_32BIT(pktin.data+st->biglen-4); + if (st->gotcrc != st->realcrc) { + bombout(("Incorrect CRC received on packet")); + crReturn(0); + } + + pktin.body = pktin.data + st->pad + 1; - pktin.type = pktin.data[pad]; - pktin.body = pktin.data + pad + 1; + if (ssh1_compressing) { + unsigned char *decompblk; + int decomplen; +#if 0 + int i; + debug(("Packet payload pre-decompression:\n")); + for (i = -1; i < pktin.length; i++) + debug((" %02x", (unsigned char)pktin.body[i])); + debug(("\r\n")); +#endif + zlib_decompress_block(pktin.body-1, pktin.length+1, + &decompblk, &decomplen); + + if (pktin.maxlen < st->pad + decomplen) { + pktin.maxlen = st->pad + decomplen; + pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA); + pktin.body = pktin.data + st->pad + 1; + if (!pktin.data) + fatalbox("Out of memory"); + } - realcrc = crc32(pktin.data, biglen-4); - gotcrc = GET_32BIT(pktin.data+biglen-4); - if (gotcrc != realcrc) { - fatalbox("Incorrect CRC received on packet"); + memcpy(pktin.body-1, decompblk, decomplen); + sfree(decompblk); + pktin.length = decomplen-1; +#if 0 + debug(("Packet payload post-decompression:\n")); + for (i = -1; i < pktin.length; i++) + debug((" %02x", (unsigned char)pktin.body[i])); + debug(("\r\n")); +#endif } if (pktin.type == SSH1_SMSG_STDOUT_DATA || pktin.type == SSH1_SMSG_STDERR_DATA || pktin.type == SSH1_MSG_DEBUG || - pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE) { + pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || + pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { long strlen = GET_32BIT(pktin.body); - if (strlen + 4 != pktin.length) - fatalbox("Received data packet with bogus string length"); + if (strlen + 4 != pktin.length) { + bombout(("Received data packet with bogus string length")); + crReturn(0); + } } + pktin.type = pktin.body[-1]; + if (pktin.type == SSH1_MSG_DEBUG) { /* log debug message */ char buf[80]; @@ -304,29 +494,24 @@ next_packet: static int ssh2_rdpkt(unsigned char **data, int *datalen) { - static long len, pad, payload, packetlen, maclen; - static int i; - static int cipherblk; - static unsigned long incoming_sequence = 0; + struct rdpkt2_state_tag *st = &rdpkt2_state; crBegin; next_packet: - pktin.type = 0; pktin.length = 0; - - if (cipher) - cipherblk = cipher->blksize; + if (sccipher) + st->cipherblk = sccipher->blksize; else - cipherblk = 8; - if (cipherblk < 8) - cipherblk = 8; - - if (pktin.maxlen < cipherblk) { - pktin.maxlen = cipherblk; - pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) : - realloc(pktin.data, cipherblk+APIEXTRA)); + st->cipherblk = 8; + if (st->cipherblk < 8) + st->cipherblk = 8; + + if (pktin.maxlen < st->cipherblk) { + pktin.maxlen = st->cipherblk; + pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) : + srealloc(pktin.data, st->cipherblk+APIEXTRA)); if (!pktin.data) fatalbox("Out of memory"); } @@ -335,10 +520,10 @@ next_packet: * Acquire and decrypt the first block of the packet. This will * contain the length and padding details. */ - for (i = len = 0; i < cipherblk; i++) { + for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { while ((*datalen) == 0) - crReturn(cipherblk-i); - pktin.data[i] = *(*data)++; + crReturn(st->cipherblk-st->i); + pktin.data[st->i] = *(*data)++; (*datalen)--; } #ifdef FWHACK @@ -347,34 +532,34 @@ next_packet: } #endif if (sccipher) - sccipher->decrypt(pktin.data, cipherblk); + sccipher->decrypt(pktin.data, st->cipherblk); /* * Now get the length and padding figures. */ - len = GET_32BIT(pktin.data); - pad = pktin.data[4]; + st->len = GET_32BIT(pktin.data); + st->pad = pktin.data[4]; /* * This enables us to deduce the payload length. */ - payload = len - pad - 1; + st->payload = st->len - st->pad - 1; - pktin.length = payload + 5; + pktin.length = st->payload + 5; /* * So now we can work out the total packet length. */ - packetlen = len + 4; - maclen = scmac ? scmac->len : 0; + st->packetlen = st->len + 4; + st->maclen = scmac ? scmac->len : 0; /* * Adjust memory allocation if packet is too big. */ - if (pktin.maxlen < packetlen) { - pktin.maxlen = packetlen; - pktin.data = (pktin.data == NULL ? malloc(packetlen+APIEXTRA) : - realloc(pktin.data, packetlen+APIEXTRA)); + if (pktin.maxlen < st->packetlen+st->maclen) { + pktin.maxlen = st->packetlen+st->maclen; + pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : + srealloc(pktin.data, pktin.maxlen+APIEXTRA)); if (!pktin.data) fatalbox("Out of memory"); } @@ -382,52 +567,71 @@ next_packet: /* * Read and decrypt the remainder of the packet. */ - for (i = cipherblk; i < packetlen + maclen; i++) { + for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) { while ((*datalen) == 0) - crReturn(packetlen + maclen - i); - pktin.data[i] = *(*data)++; + crReturn(st->packetlen + st->maclen - st->i); + pktin.data[st->i] = *(*data)++; (*datalen)--; } /* Decrypt everything _except_ the MAC. */ if (sccipher) - sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk); - - /* - * Check the MAC. - */ - if (scmac && !scmac->verify(pktin.data, incoming_sequence++, len+4)) - fatalbox("Incorrect MAC received on packet"); + sccipher->decrypt(pktin.data + st->cipherblk, + st->packetlen - st->cipherblk); - pktin.savedpos = 6; - pktin.type = pktin.data[5]; #if 0 - debug(("Got packet len=%d pad=%d\r\n", len, pad)); - for (i = 0; i < payload; i++) - debug((" %02x", (unsigned char)pktin.data[i])); + debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); + for (st->i = 0; st->i < st->packetlen; st->i++) + debug((" %02x", (unsigned char)pktin.data[st->i])); debug(("\r\n")); #endif /* - * FIXME: handle IGNORE and DEBUG messages. + * Check the MAC. */ + if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) { + bombout(("Incorrect MAC received on packet")); + crReturn(0); + } + st->incoming_sequence++; /* whether or not we MACed */ - crFinish(0); -} + /* + * Decompress packet payload. + */ + { + unsigned char *newpayload; + int newlen; + if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5, + &newpayload, &newlen)) { + if (pktin.maxlen < newlen+5) { + pktin.maxlen = newlen+5; + pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : + srealloc(pktin.data, pktin.maxlen+APIEXTRA)); + if (!pktin.data) + fatalbox("Out of memory"); + } + pktin.length = 5 + newlen; + memcpy(pktin.data+5, newpayload, newlen); +#if 0 + debug(("Post-decompression payload:\r\n")); + for (st->i = 0; st->i < newlen; st->i++) + debug((" %02x", (unsigned char)pktin.data[5+st->i])); + debug(("\r\n")); +#endif -static void ssh_gotdata(unsigned char *data, int datalen) -{ - while (datalen > 0) { - if ( s_rdpkt(&data, &datalen) == 0 ) { - ssh_protocol(NULL, 0, 1); - if (ssh_state == SSH_STATE_CLOSED) { - return; - } - } + sfree(newpayload); + } } -} + pktin.savedpos = 6; + pktin.type = pktin.data[5]; -static void s_wrpkt_start(int type, int len) { + if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) + goto next_packet; /* FIXME: print DEBUG message */ + + crFinish(0); +} + +static void ssh1_pktout_size(int len) { int pad, biglen; len += 5; /* type and CRC */ @@ -440,216 +644,181 @@ static void s_wrpkt_start(int type, int len) { #ifdef MSCRYPTOAPI /* Allocate enough buffer space for extra block * for MS CryptEncrypt() */ - pktout.data = (pktout.data == NULL ? malloc(biglen+12) : - realloc(pktout.data, biglen+12)); + pktout.data = (pktout.data == NULL ? smalloc(biglen+12) : + srealloc(pktout.data, biglen+12)); #else - pktout.data = (pktout.data == NULL ? malloc(biglen+4) : - realloc(pktout.data, biglen+4)); + pktout.data = (pktout.data == NULL ? smalloc(biglen+4) : + srealloc(pktout.data, biglen+4)); #endif if (!pktout.data) fatalbox("Out of memory"); } + pktout.body = pktout.data+4+pad+1; +} +static void s_wrpkt_start(int type, int len) { + ssh1_pktout_size(len); pktout.type = type; - pktout.body = pktout.data+4+pad+1; } -static void s_wrpkt(void) { +static int s_wrpkt_prepare(void) { int pad, len, biglen, i; unsigned long crc; + pktout.body[-1] = pktout.type; + +#if 0 + debug(("Packet payload pre-compression:\n")); + for (i = -1; i < pktout.length; i++) + debug((" %02x", (unsigned char)pktout.body[i])); + debug(("\r\n")); +#endif + + if (ssh1_compressing) { + unsigned char *compblk; + int complen; + zlib_compress_block(pktout.body-1, pktout.length+1, + &compblk, &complen); + ssh1_pktout_size(complen-1); + memcpy(pktout.body-1, compblk, complen); + sfree(compblk); +#if 0 + debug(("Packet payload post-compression:\n")); + for (i = -1; i < pktout.length; i++) + debug((" %02x", (unsigned char)pktout.body[i])); + debug(("\r\n")); +#endif + } + len = pktout.length + 5; /* type and CRC */ pad = 8 - (len%8); biglen = len + pad; - pktout.body[-1] = pktout.type; for (i=0; iencrypt(pktout.data+4, biglen); - s_write(pktout.data, biglen+4); + return biglen+4; +} + +static void s_wrpkt(void) { + int len; + len = s_wrpkt_prepare(); + sk_write(s, pktout.data, len); +} + +static void s_wrpkt_defer(void) { + int len; + len = s_wrpkt_prepare(); + if (deferred_len + len > deferred_size) { + deferred_size = deferred_len + len + 128; + deferred_send_data = srealloc(deferred_send_data, deferred_size); + } + memcpy(deferred_send_data+deferred_len, pktout.data, len); + deferred_len += len; } /* - * Construct a packet with the specified contents and - * send it to the server. + * Construct a packet with the specified contents. */ -static void send_packet(int pkttype, ...) +static void construct_packet(int pkttype, va_list ap1, va_list ap2) { - va_list args; unsigned char *p, *argp, argchar; unsigned long argint; int pktlen, argtype, arglen; + Bignum bn; pktlen = 0; - va_start(args, pkttype); - while ((argtype = va_arg(args, int)) != PKT_END) { + while ((argtype = va_arg(ap1, int)) != PKT_END) { switch (argtype) { case PKT_INT: - (void) va_arg(args, int); + (void) va_arg(ap1, int); pktlen += 4; break; case PKT_CHAR: - (void) va_arg(args, char); + (void) va_arg(ap1, char); pktlen++; break; case PKT_DATA: - (void) va_arg(args, unsigned char *); - arglen = va_arg(args, int); + (void) va_arg(ap1, unsigned char *); + arglen = va_arg(ap1, int); pktlen += arglen; break; case PKT_STR: - argp = va_arg(args, unsigned char *); + argp = va_arg(ap1, unsigned char *); arglen = strlen(argp); pktlen += 4 + arglen; break; + case PKT_BIGNUM: + bn = va_arg(ap1, Bignum); + pktlen += ssh1_bignum_length(bn); + break; default: assert(0); } } - va_end(args); s_wrpkt_start(pkttype, pktlen); p = pktout.body; - va_start(args, pkttype); - while ((argtype = va_arg(args, int)) != PKT_END) { + while ((argtype = va_arg(ap2, int)) != PKT_END) { switch (argtype) { case PKT_INT: - argint = va_arg(args, int); + argint = va_arg(ap2, int); PUT_32BIT(p, argint); p += 4; break; case PKT_CHAR: - argchar = va_arg(args, unsigned char); + argchar = va_arg(ap2, unsigned char); *p = argchar; p++; break; case PKT_DATA: - argp = va_arg(args, unsigned char *); - arglen = va_arg(args, int); + argp = va_arg(ap2, unsigned char *); + arglen = va_arg(ap2, int); memcpy(p, argp, arglen); p += arglen; break; case PKT_STR: - argp = va_arg(args, unsigned char *); + argp = va_arg(ap2, unsigned char *); arglen = strlen(argp); PUT_32BIT(p, arglen); memcpy(p + 4, argp, arglen); p += 4 + arglen; break; + case PKT_BIGNUM: + bn = va_arg(ap2, Bignum); + p += ssh1_write_bignum(p, bn); + break; } } - va_end(args); +} +static void send_packet(int pkttype, ...) { + va_list ap1, ap2; + va_start(ap1, pkttype); + va_start(ap2, pkttype); + construct_packet(pkttype, ap1, ap2); s_wrpkt(); } - -/* - * Connect to specified host and port. - * Returns an error message, or NULL on success. - * Also places the canonical host name into `realhost'. - */ -static char *connect_to_host(char *host, int port, char **realhost) -{ - SOCKADDR_IN addr; - struct hostent *h; - unsigned long a; -#ifdef FWHACK - char *FWhost; - int FWport; -#endif - - savedhost = malloc(1+strlen(host)); - if (!savedhost) - fatalbox("Out of memory"); - strcpy(savedhost, host); - - if (port < 0) - port = 22; /* default ssh port */ - -#ifdef FWHACK - FWhost = host; - FWport = port; - host = FWSTR; - port = 23; -#endif - - /* - * Try to find host. - */ - if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) { - if ( (h = gethostbyname(host)) == NULL) - switch (WSAGetLastError()) { - case WSAENETDOWN: return "Network is down"; - case WSAHOST_NOT_FOUND: case WSANO_DATA: - return "Host does not exist"; - case WSATRY_AGAIN: return "Host not found"; - default: return "gethostbyname: unknown error"; - } - memcpy (&a, h->h_addr, sizeof(a)); - *realhost = h->h_name; - } else - *realhost = host; -#ifdef FWHACK - *realhost = FWhost; -#endif - a = ntohl(a); - - /* - * Open socket. - */ - s = socket(AF_INET, SOCK_STREAM, 0); - if (s == INVALID_SOCKET) - switch (WSAGetLastError()) { - case WSAENETDOWN: return "Network is down"; - case WSAEAFNOSUPPORT: return "TCP/IP support not present"; - default: return "socket(): unknown error"; - } - - /* - * Bind to local address. - */ - addr.sin_family = AF_INET; - addr.sin_addr.s_addr = htonl(INADDR_ANY); - addr.sin_port = htons(0); - if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR) - switch (WSAGetLastError()) { - case WSAENETDOWN: return "Network is down"; - default: return "bind(): unknown error"; - } - - /* - * Connect to remote address. - */ - addr.sin_addr.s_addr = htonl(a); - addr.sin_port = htons((short)port); - if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR) - switch (WSAGetLastError()) { - case WSAENETDOWN: return "Network is down"; - case WSAECONNREFUSED: return "Connection refused"; - case WSAENETUNREACH: return "Network is unreachable"; - case WSAEHOSTUNREACH: return "No route to host"; - default: return "connect(): unknown error"; - } - -#ifdef FWHACK - send(s, "connect ", 8, 0); - send(s, FWhost, strlen(FWhost), 0); - { - char buf[20]; - sprintf(buf, " %d\n", FWport); - send (s, buf, strlen(buf), 0); - } -#endif - - return NULL; +static void defer_packet(int pkttype, ...) { + va_list ap1, ap2; + va_start(ap1, pkttype); + va_start(ap2, pkttype); + construct_packet(pkttype, ap1, ap2); + s_wrpkt_defer(); } static int ssh_versioncmp(char *a, char *b) { @@ -669,884 +838,3005 @@ static int ssh_versioncmp(char *a, char *b) { /* - * Utility routine for putting an SSH-protocol `string' into a SHA - * state. + * Utility routines for putting an SSH-protocol `string' and + * `uint32' into a SHA state. */ #include -void sha_string(SHA_State *s, void *str, int len) { +static void sha_string(SHA_State *s, void *str, int len) { unsigned char lenblk[4]; -static FILE *fp; PUT_32BIT(lenblk, len); -if (!fp) fp = fopen("h:\\statham\\windows\\putty\\data","wb"); -fwrite(lenblk, 4, 1, fp); SHA_Bytes(s, lenblk, 4); -fwrite(str, len, 1, fp); -fflush(fp); SHA_Bytes(s, str, len); } -static int do_ssh_init(void) { - char c, *vsp; - char version[10]; - char vstring[80]; - char vlog[sizeof(vstring)+20]; - int i; - -#ifdef FWHACK - i = 0; - while (s_read(&c, 1) == 1) { - if (c == 'S' && i < 2) i++; - else if (c == 'S' && i == 2) i = 2; - else if (c == 'H' && i == 2) break; - else i = 0; - } -#else - if (s_read(&c,1) != 1 || c != 'S') return 0; - if (s_read(&c,1) != 1 || c != 'S') return 0; - if (s_read(&c,1) != 1 || c != 'H') return 0; -#endif - strcpy(vstring, "SSH-"); - vsp = vstring+4; - if (s_read(&c,1) != 1 || c != '-') return 0; - i = 0; - while (1) { - if (s_read(&c,1) != 1) - return 0; - if (vsp < vstring+sizeof(vstring)-1) - *vsp++ = c; - if (i >= 0) { - if (c == '-') { - version[i] = '\0'; - i = -1; - } else if (i < sizeof(version)-1) - version[i++] = c; - } - else if (c == '\n') - break; - } - - *vsp = 0; - sprintf(vlog, "Server version: %s", vstring); - vlog[strcspn(vlog, "\r\n")] = '\0'; - logevent(vlog); - - if (ssh_versioncmp(version, "1.99") >= 0) { - /* - * This is a v2 server. Begin v2 protocol. - */ - char *verstring = "SSH-2.0-PuTTY"; - SHA_Init(&exhash); - /* - * Hash our version string and their version string. - */ - sha_string(&exhash, verstring, strlen(verstring)); - sha_string(&exhash, vstring, strcspn(vstring, "\r\n")); - sprintf(vstring, "%s\n", verstring); - sprintf(vlog, "We claim version: %s", verstring); - logevent(vlog); - logevent("Using SSH protocol version 2"); - s_write(vstring, strlen(vstring)); - ssh_protocol = ssh2_protocol; - s_rdpkt = ssh2_rdpkt; - } else { - /* - * This is a v1 server. Begin v1 protocol. - */ - sprintf(vstring, "SSH-%s-PuTTY\n", - (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5")); - sprintf(vlog, "We claim version: %s", vstring); - vlog[strcspn(vlog, "\r\n")] = '\0'; - logevent(vlog); - logevent("Using SSH protocol version 1"); - s_write(vstring, strlen(vstring)); - ssh_protocol = ssh1_protocol; - s_rdpkt = ssh1_rdpkt; - } - return 1; +static void sha_uint32(SHA_State *s, unsigned i) { + unsigned char intblk[4]; + PUT_32BIT(intblk, i); + SHA_Bytes(s, intblk, 4); } /* - * Handle the key exchange and user authentication phases. + * SSH2 packet construction functions. */ -static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) -{ - int i, j, len; - unsigned char session_id[16]; - unsigned char *rsabuf, *keystr1, *keystr2; - unsigned char cookie[8]; - struct RSAKey servkey, hostkey; - struct MD5Context md5c; - static unsigned long supported_ciphers_mask, supported_auths_mask; - int cipher_type; - - crBegin; - - if (!ispkt) crWaitUntil(ispkt); - - if (pktin.type != SSH1_SMSG_PUBLIC_KEY) - fatalbox("Public key packet not received"); - - logevent("Received public keys"); - - memcpy(cookie, pktin.body, 8); +static void ssh2_pkt_ensure(int length) { + if (pktout.maxlen < length) { + pktout.maxlen = length + 256; + pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) : + srealloc(pktout.data, pktout.maxlen+APIEXTRA)); + if (!pktout.data) + fatalbox("Out of memory"); + } +} +static void ssh2_pkt_adddata(void *data, int len) { + pktout.length += len; + ssh2_pkt_ensure(pktout.length); + memcpy(pktout.data+pktout.length-len, data, len); +} +static void ssh2_pkt_addbyte(unsigned char byte) { + ssh2_pkt_adddata(&byte, 1); +} +static void ssh2_pkt_init(int pkt_type) { + pktout.length = 5; + ssh2_pkt_addbyte((unsigned char)pkt_type); +} +static void ssh2_pkt_addbool(unsigned char value) { + ssh2_pkt_adddata(&value, 1); +} +static void ssh2_pkt_adduint32(unsigned long value) { + unsigned char x[4]; + PUT_32BIT(x, value); + ssh2_pkt_adddata(x, 4); +} +static void ssh2_pkt_addstring_start(void) { + ssh2_pkt_adduint32(0); + pktout.savedpos = pktout.length; +} +static void ssh2_pkt_addstring_str(char *data) { + ssh2_pkt_adddata(data, strlen(data)); + PUT_32BIT(pktout.data + pktout.savedpos - 4, + pktout.length - pktout.savedpos); +} +static void ssh2_pkt_addstring_data(char *data, int len) { + ssh2_pkt_adddata(data, len); + PUT_32BIT(pktout.data + pktout.savedpos - 4, + pktout.length - pktout.savedpos); +} +static void ssh2_pkt_addstring(char *data) { + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_str(data); +} +static char *ssh2_mpint_fmt(Bignum b, int *len) { + unsigned char *p; + int i, n = (ssh1_bignum_bitcount(b)+7)/8; + p = smalloc(n + 1); + if (!p) + fatalbox("out of memory"); + p[0] = 0; + for (i = 1; i <= n; i++) + p[i] = bignum_byte(b, n-i); + i = 0; + while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0) + i++; + memmove(p, p+i, n+1-i); + *len = n+1-i; + return p; +} +static void ssh2_pkt_addmp(Bignum b) { + unsigned char *p; + int len; + p = ssh2_mpint_fmt(b, &len); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(p, len); + sfree(p); +} - i = makekey(pktin.body+8, &servkey, &keystr1); - j = makekey(pktin.body+8+i, &hostkey, &keystr2); +/* + * Construct an SSH2 final-form packet: compress it, encrypt it, + * put the MAC on it. Final packet, ready to be sent, is stored in + * pktout.data. Total length is returned. + */ +static int ssh2_pkt_construct(void) { + int cipherblk, maclen, padding, i; + static unsigned long outgoing_sequence = 0; /* - * Hash the host key and print the hash in the log box. Just as - * a last resort in case the registry's host key checking is - * compromised, we'll allow the user some ability to verify - * host keys by eye. + * Compress packet payload. */ - MD5Init(&md5c); - MD5Update(&md5c, keystr2, hostkey.bytes); - MD5Final(session_id, &md5c); +#if 0 + debug(("Pre-compression payload:\r\n")); + for (i = 5; i < pktout.length; i++) + debug((" %02x", (unsigned char)pktout.data[i])); + debug(("\r\n")); +#endif { - char logmsg[80]; - int i; - logevent("Host key MD5 is:"); - strcpy(logmsg, " "); - for (i = 0; i < 16; i++) - sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]); - logevent(logmsg); + unsigned char *newpayload; + int newlen; + if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5, + &newpayload, &newlen)) { + pktout.length = 5; + ssh2_pkt_adddata(newpayload, newlen); + sfree(newpayload); + } } - supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j); - supported_auths_mask = GET_32BIT(pktin.body+16+i+j); - - MD5Init(&md5c); - MD5Update(&md5c, keystr2, hostkey.bytes); - MD5Update(&md5c, keystr1, servkey.bytes); - MD5Update(&md5c, pktin.body, 8); - MD5Final(session_id, &md5c); - - for (i=0; i<32; i++) - session_key[i] = random_byte(); - - len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); - - rsabuf = malloc(len); - if (!rsabuf) - fatalbox("Out of memory"); - /* - * Verify the host key. + * Add padding. At least four bytes, and must also bring total + * length (minus MAC) up to a multiple of the block size. */ - { - /* - * First format the key into a string. - */ - int len = rsastr_len(&hostkey); - char *keystr = malloc(len); - if (!keystr) - fatalbox("Out of memory"); - rsastr_fmt(keystr, &hostkey); - verify_ssh_host_key(savedhost, keystr); - free(keystr); - } + cipherblk = cscipher ? cscipher->blksize : 8; /* block size */ + cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ + padding = 4; + padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; + maclen = csmac ? csmac->len : 0; + ssh2_pkt_ensure(pktout.length + padding + maclen); + pktout.data[4] = padding; + for (i = 0; i < padding; i++) + pktout.data[pktout.length + i] = random_byte(); + PUT_32BIT(pktout.data, pktout.length + padding - 4); + if (csmac) + csmac->generate(pktout.data, pktout.length + padding, + outgoing_sequence); + outgoing_sequence++; /* whether or not we MACed */ - for (i=0; i<32; i++) { - rsabuf[i] = session_key[i]; - if (i < 16) - rsabuf[i] ^= session_id[i]; - } +#if 0 + debug(("Sending packet len=%d\r\n", pktout.length+padding)); + for (i = 0; i < pktout.length+padding; i++) + debug((" %02x", (unsigned char)pktout.data[i])); + debug(("\r\n")); +#endif - if (hostkey.bytes > servkey.bytes) { - rsaencrypt(rsabuf, 32, &servkey); - rsaencrypt(rsabuf, servkey.bytes, &hostkey); - } else { - rsaencrypt(rsabuf, 32, &hostkey); - rsaencrypt(rsabuf, hostkey.bytes, &servkey); - } + if (cscipher) + cscipher->encrypt(pktout.data, pktout.length + padding); - logevent("Encrypted session key"); + /* Ready-to-send packet starts at pktout.data. We return length. */ + return pktout.length + padding + maclen; +} - cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH : - cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES : - SSH_CIPHER_3DES; - if ((supported_ciphers_mask & (1 << cipher_type)) == 0) { - c_write("Selected cipher not supported, falling back to 3DES\r\n", 53); - cipher_type = SSH_CIPHER_3DES; - } - switch (cipher_type) { - case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break; - case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break; - case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break; - } +/* + * Construct and send an SSH2 packet immediately. + */ +static void ssh2_pkt_send(void) { + int len = ssh2_pkt_construct(); + sk_write(s, pktout.data, len); +} - send_packet(SSH1_CMSG_SESSION_KEY, - PKT_CHAR, cipher_type, - PKT_DATA, cookie, 8, - PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF, - PKT_DATA, rsabuf, len, - PKT_INT, 0, - PKT_END); +/* + * Construct an SSH2 packet and add it to a deferred data block. + * Useful for sending multiple packets in a single sk_write() call, + * to prevent a traffic-analysing listener from being able to work + * out the length of any particular packet (such as the password + * packet). + * + * Note that because SSH2 sequence-numbers its packets, this can + * NOT be used as an m4-style `defer' allowing packets to be + * constructed in one order and sent in another. + */ +static void ssh2_pkt_defer(void) { + int len = ssh2_pkt_construct(); + if (deferred_len + len > deferred_size) { + deferred_size = deferred_len + len + 128; + deferred_send_data = srealloc(deferred_send_data, deferred_size); + } + memcpy(deferred_send_data+deferred_len, pktout.data, len); + deferred_len += len; +} - logevent("Trying to enable encryption..."); +/* + * Send the whole deferred data block constructed by + * ssh2_pkt_defer() or SSH1's defer_packet(). + */ +static void ssh_pkt_defersend(void) { + sk_write(s, deferred_send_data, deferred_len); + deferred_len = deferred_size = 0; + sfree(deferred_send_data); + deferred_send_data = NULL; +} - free(rsabuf); +#if 0 +void bndebug(char *string, Bignum b) { + unsigned char *p; + int i, len; + p = ssh2_mpint_fmt(b, &len); + debug(("%s", string)); + for (i = 0; i < len; i++) + debug((" %02x", p[i])); + debug(("\r\n")); + sfree(p); +} +#endif - cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish : - cipher_type == SSH_CIPHER_DES ? &ssh_des : - &ssh_3des; - cipher->sesskey(session_key); +static void sha_mpint(SHA_State *s, Bignum b) { + unsigned char *p; + int len; + p = ssh2_mpint_fmt(b, &len); + sha_string(s, p, len); + sfree(p); +} - crWaitUntil(ispkt); +/* + * SSH2 packet decode functions. + */ +static unsigned long ssh2_pkt_getuint32(void) { + unsigned long value; + if (pktin.length - pktin.savedpos < 4) + return 0; /* arrgh, no way to decline (FIXME?) */ + value = GET_32BIT(pktin.data+pktin.savedpos); + pktin.savedpos += 4; + return value; +} +static int ssh2_pkt_getbool(void) { + unsigned long value; + if (pktin.length - pktin.savedpos < 1) + return 0; /* arrgh, no way to decline (FIXME?) */ + value = pktin.data[pktin.savedpos] != 0; + pktin.savedpos++; + return value; +} +static void ssh2_pkt_getstring(char **p, int *length) { + *p = NULL; + if (pktin.length - pktin.savedpos < 4) + return; + *length = GET_32BIT(pktin.data+pktin.savedpos); + pktin.savedpos += 4; + if (pktin.length - pktin.savedpos < *length) + return; + *p = pktin.data+pktin.savedpos; + pktin.savedpos += *length; +} +static Bignum ssh2_pkt_getmp(void) { + char *p; + int length; + Bignum b; - if (pktin.type != SSH1_SMSG_SUCCESS) - fatalbox("Encryption not successfully enabled"); + ssh2_pkt_getstring(&p, &length); + if (!p) + return NULL; + if (p[0] & 0x80) { + bombout(("internal error: Can't handle negative mpints")); + return NULL; + } + b = bignum_from_bytes(p, length); + return b; +} - logevent("Successfully started encryption"); +/* + * Examine the remote side's version string and compare it against + * a list of known buggy implementations. + */ +static void ssh_detect_bugs(char *vstring) { + char *imp; /* pointer to implementation part */ + imp = vstring; + imp += strcspn(imp, "-"); + imp += strcspn(imp, "-"); - fflush(stdout); - { - static char username[100]; - static int pos = 0; - static char c; - if (!IS_SCP && !*cfg.username) { - c_write("login as: ", 10); - while (pos >= 0) { - crWaitUntil(!ispkt); - while (inlen--) switch (c = *in++) { - case 10: case 13: - username[pos] = 0; - pos = -1; - break; - case 8: case 127: - if (pos > 0) { - c_write("\b \b", 3); - pos--; - } - break; - case 21: case 27: - while (pos > 0) { - c_write("\b \b", 3); - pos--; - } - break; - case 3: case 4: - random_save_seed(); - exit(0); - break; - default: - if (((c >= ' ' && c <= '~') || - ((unsigned char)c >= 160)) && pos < 40) { - username[pos++] = c; - c_write(&c, 1); - } - break; - } - } - c_write("\r\n", 2); - username[strcspn(username, "\n\r")] = '\0'; - } else { - char stuff[200]; - strncpy(username, cfg.username, 99); - username[99] = '\0'; - if (!IS_SCP) { - sprintf(stuff, "Sent username \"%s\".\r\n", username); - c_write(stuff, strlen(stuff)); - } - } + ssh_remote_bugs = 0; - send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); - { - char userlog[20+sizeof(username)]; - sprintf(userlog, "Sent username \"%s\"", username); - logevent(userlog); - } + if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || + !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || + !strcmp(imp, "1.2.22")) { + /* + * These versions don't support SSH1_MSG_IGNORE, so we have + * to use a different defence against password length + * sniffing. + */ + ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; + logevent("We believe remote version has SSH1 ignore bug"); } - crWaitUntil(ispkt); - - while (pktin.type == SSH1_SMSG_FAILURE) { - static char password[100]; - static int pos; - static char c; - static int pwpkt_type; - + if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) || + !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) || + !strncmp(imp, "2.1 ", 4)) { /* - * Show password prompt, having first obtained it via a TIS - * exchange if we're doing TIS authentication. + * These versions have the HMAC bug. */ - pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; + ssh_remote_bugs |= BUG_SSH2_HMAC; + logevent("We believe remote version has SSH2 HMAC bug"); + } +} - if (IS_SCP) { - char prompt[200]; - sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost); - if (!ssh_get_password(prompt, password, sizeof(password))) { - /* - * get_password failed to get a password (for - * example because one was supplied on the command - * line which has already failed to work). - * Terminate. - */ - logevent("No more passwords to try"); - ssh_state = SSH_STATE_CLOSED; - crReturn(1); - } - } else { +static int do_ssh_init(unsigned char c) { + static char *vsp; + static char version[10]; + static char vstring[80]; + static char vlog[sizeof(vstring)+20]; + static int i; - if (pktin.type == SSH1_SMSG_FAILURE && + crBegin; + + /* Search for the string "SSH-" in the input. */ + 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') i = transS[i]; + else if (c == 'H') i = transH[i]; + else if (c == '-') i = transminus[i]; + else i = 0; + if (i < 0) + break; + crReturn(1); /* get another character */ + } + + strcpy(vstring, "SSH-"); + vsp = vstring+4; + i = 0; + while (1) { + crReturn(1); /* get another char */ + if (vsp < vstring+sizeof(vstring)-1) + *vsp++ = c; + if (i >= 0) { + if (c == '-') { + version[i] = '\0'; + i = -1; + } else if (i < sizeof(version)-1) + version[i++] = c; + } + else if (c == '\n') + break; + } + + ssh_agentfwd_enabled = FALSE; + rdpkt2_state.incoming_sequence = 0; + + *vsp = 0; + sprintf(vlog, "Server version: %s", vstring); + ssh_detect_bugs(vstring); + vlog[strcspn(vlog, "\r\n")] = '\0'; + logevent(vlog); + + /* + * Server version "1.99" means we can choose whether we use v1 + * or v2 protocol. Choice is based on cfg.sshprot. + */ + if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) { + /* + * This is a v2 server. Begin v2 protocol. + */ + char *verstring = "SSH-2.0-PuTTY"; + SHA_Init(&exhashbase); + /* + * Hash our version string and their version string. + */ + sha_string(&exhashbase, verstring, strlen(verstring)); + sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n")); + sprintf(vstring, "%s\n", verstring); + sprintf(vlog, "We claim version: %s", verstring); + logevent(vlog); + logevent("Using SSH protocol version 2"); + sk_write(s, vstring, strlen(vstring)); + ssh_protocol = ssh2_protocol; + ssh_version = 2; + s_rdpkt = ssh2_rdpkt; + } else { + /* + * This is a v1 server. Begin v1 protocol. + */ + sprintf(vstring, "SSH-%s-PuTTY\n", + (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5")); + sprintf(vlog, "We claim version: %s", vstring); + vlog[strcspn(vlog, "\r\n")] = '\0'; + logevent(vlog); + logevent("Using SSH protocol version 1"); + sk_write(s, vstring, strlen(vstring)); + ssh_protocol = ssh1_protocol; + ssh_version = 1; + s_rdpkt = ssh1_rdpkt; + } + ssh_state = SSH_STATE_BEFORE_SIZE; + + crFinish(0); +} + +static void ssh_gotdata(unsigned char *data, int datalen) +{ + crBegin; + + /* + * To begin with, feed the characters one by one to the + * protocol initialisation / selection function do_ssh_init(). + * When that returns 0, we're done with the initial greeting + * exchange and can move on to packet discipline. + */ + while (1) { + int ret; + if (datalen == 0) + crReturnV; /* more data please */ + ret = do_ssh_init(*data); + data++; datalen--; + if (ret == 0) + break; + } + + /* + * We emerge from that loop when the initial negotiation is + * over and we have selected an s_rdpkt function. Now pass + * everything to s_rdpkt, and then pass the resulting packets + * to the proper protocol handler. + */ + if (datalen == 0) + crReturnV; + while (1) { + while (datalen > 0) { + if ( s_rdpkt(&data, &datalen) == 0 ) { + ssh_protocol(NULL, 0, 1); + if (ssh_state == SSH_STATE_CLOSED) { + return; + } + } + } + crReturnV; + } + crFinishV; +} + +static int ssh_closing (Plug plug, char *error_msg, int error_code, int calling_back) { + ssh_state = SSH_STATE_CLOSED; + sk_close(s); + s = NULL; + if (error_msg) { + /* A socket error has occurred. */ + connection_fatal (error_msg); + } else { + /* Otherwise, the remote side closed the connection normally. */ + } + return 0; +} + +static int ssh_receive(Plug plug, int urgent, char *data, int len) { + ssh_gotdata (data, len); + if (ssh_state == SSH_STATE_CLOSED) { + if (s) { + sk_close(s); + s = NULL; + } + return 0; + } + return 1; +} + +/* + * Connect to specified host and port. + * Returns an error message, or NULL on success. + * Also places the canonical host name into `realhost'. + */ +static char *connect_to_host(char *host, int port, char **realhost) +{ + static struct plug_function_table fn_table = { + ssh_closing, + ssh_receive + }, *fn_table_ptr = &fn_table; + + SockAddr addr; + char *err; +#ifdef FWHACK + char *FWhost; + int FWport; +#endif + + savedhost = smalloc(1+strlen(host)); + if (!savedhost) + fatalbox("Out of memory"); + strcpy(savedhost, host); + + if (port < 0) + port = 22; /* default ssh port */ + savedport = port; + +#ifdef FWHACK + FWhost = host; + FWport = port; + host = FWSTR; + port = 23; +#endif + + /* + * Try to find host. + */ + addr = sk_namelookup(host, realhost); + if ( (err = sk_addr_error(addr)) ) + return err; + +#ifdef FWHACK + *realhost = FWhost; +#endif + + /* + * Open socket. + */ + s = sk_new(addr, port, 0, 1, &fn_table_ptr); + if ( (err = sk_socket_error(s)) ) + return err; + +#ifdef FWHACK + sk_write(s, "connect ", 8); + sk_write(s, FWhost, strlen(FWhost)); + { + char buf[20]; + sprintf(buf, " %d\n", FWport); + sk_write(s, buf, strlen(buf)); + } +#endif + + return NULL; +} + +/* + * Handle the key exchange and user authentication phases. + */ +static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) +{ + int i, j, len; + unsigned char *rsabuf, *keystr1, *keystr2; + unsigned char cookie[8]; + struct RSAKey servkey, hostkey; + struct MD5Context md5c; + static unsigned long supported_ciphers_mask, supported_auths_mask; + static int tried_publickey; + static unsigned char session_id[16]; + int cipher_type; + static char username[100]; + + crBegin; + + if (!ispkt) crWaitUntil(ispkt); + + if (pktin.type != SSH1_SMSG_PUBLIC_KEY) { + bombout(("Public key packet not received")); + crReturn(0); + } + + logevent("Received public keys"); + + memcpy(cookie, pktin.body, 8); + + i = makekey(pktin.body+8, &servkey, &keystr1, 0); + j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0); + + /* + * Log the host key fingerprint. + */ + { + char logmsg[80]; + logevent("Host key fingerprint is:"); + strcpy(logmsg, " "); + hostkey.comment = NULL; + rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg), + &hostkey); + logevent(logmsg); + } + + supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j); + supported_auths_mask = GET_32BIT(pktin.body+16+i+j); + + MD5Init(&md5c); + MD5Update(&md5c, keystr2, hostkey.bytes); + MD5Update(&md5c, keystr1, servkey.bytes); + MD5Update(&md5c, pktin.body, 8); + MD5Final(session_id, &md5c); + + for (i=0; i<32; i++) + session_key[i] = random_byte(); + + len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); + + rsabuf = smalloc(len); + if (!rsabuf) + fatalbox("Out of memory"); + + /* + * Verify the host key. + */ + { + /* + * First format the key into a string. + */ + int len = rsastr_len(&hostkey); + char fingerprint[100]; + char *keystr = smalloc(len); + if (!keystr) + fatalbox("Out of memory"); + rsastr_fmt(keystr, &hostkey); + rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); + verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint); + sfree(keystr); + } + + for (i=0; i<32; i++) { + rsabuf[i] = session_key[i]; + if (i < 16) + rsabuf[i] ^= session_id[i]; + } + + if (hostkey.bytes > servkey.bytes) { + rsaencrypt(rsabuf, 32, &servkey); + rsaencrypt(rsabuf, servkey.bytes, &hostkey); + } else { + rsaencrypt(rsabuf, 32, &hostkey); + rsaencrypt(rsabuf, hostkey.bytes, &servkey); + } + + logevent("Encrypted session key"); + + switch (cfg.cipher) { + case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break; + case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break; + case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break; + case CIPHER_AES: + c_write_str("AES not supported in SSH1, falling back to 3DES\r\n"); + cipher_type = SSH_CIPHER_3DES; + break; + } + if ((supported_ciphers_mask & (1 << cipher_type)) == 0) { + c_write_str("Selected cipher not supported, falling back to 3DES\r\n"); + cipher_type = SSH_CIPHER_3DES; + } + switch (cipher_type) { + case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break; + case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break; + case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break; + } + + send_packet(SSH1_CMSG_SESSION_KEY, + PKT_CHAR, cipher_type, + PKT_DATA, cookie, 8, + PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF, + PKT_DATA, rsabuf, len, + PKT_INT, 0, + PKT_END); + + logevent("Trying to enable encryption..."); + + sfree(rsabuf); + + cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : + cipher_type == SSH_CIPHER_DES ? &ssh_des : + &ssh_3des; + cipher->sesskey(session_key); + + crWaitUntil(ispkt); + + if (pktin.type != SSH1_SMSG_SUCCESS) { + bombout(("Encryption not successfully enabled")); + crReturn(0); + } + + logevent("Successfully started encryption"); + + fflush(stdout); + { + static int pos = 0; + static char c; + if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { + if (ssh_get_line) { + if (!ssh_get_line("login as: ", + username, sizeof(username), FALSE)) { + /* + * get_line failed to get a username. + * Terminate. + */ + logevent("No username provided. Abandoning session."); + ssh_state = SSH_STATE_CLOSED; + crReturn(1); + } + } else { + c_write_str("login as: "); + ssh_send_ok = 1; + while (pos >= 0) { + crWaitUntil(!ispkt); + while (inlen--) switch (c = *in++) { + case 10: case 13: + username[pos] = 0; + pos = -1; + break; + case 8: case 127: + if (pos > 0) { + c_write_str("\b \b"); + pos--; + } + break; + case 21: case 27: + while (pos > 0) { + c_write_str("\b \b"); + pos--; + } + break; + case 3: case 4: + random_save_seed(); + exit(0); + break; + default: + if (((c >= ' ' && c <= '~') || + ((unsigned char)c >= 160)) && pos < 40) { + username[pos++] = c; + c_write(&c, 1); + } + break; + } + } + c_write_str("\r\n"); + username[strcspn(username, "\n\r")] = '\0'; + } + } else { + strncpy(username, cfg.username, 99); + username[99] = '\0'; + } + + send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); + { + char userlog[22+sizeof(username)]; + sprintf(userlog, "Sent username \"%s\"", username); + logevent(userlog); + if (flags & FLAG_INTERACTIVE && + (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { + strcat(userlog, "\r\n"); + c_write_str(userlog); + } + } + } + + crWaitUntil(ispkt); + + tried_publickey = 0; + + while (pktin.type == SSH1_SMSG_FAILURE) { + static char password[100]; + static char prompt[200]; + static int pos; + static char c; + static int pwpkt_type; + /* + * Show password prompt, having first obtained it via a TIS + * or CryptoCard exchange if we're doing TIS or CryptoCard + * authentication. + */ + pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; + if (agent_exists()) { + /* + * Attempt RSA authentication using Pageant. + */ + static unsigned char request[5], *response, *p; + static int responselen; + static int i, nkeys; + static int authed = FALSE; + void *r; + + logevent("Pageant is running. Requesting keys."); + + /* Request the keys held by the agent. */ + PUT_32BIT(request, 1); + request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; + agent_query(request, 5, &r, &responselen); + response = (unsigned char *)r; + if (response) { + p = response + 5; + nkeys = GET_32BIT(p); p += 4; + { char buf[64]; sprintf(buf, "Pageant has %d SSH1 keys", nkeys); + logevent(buf); } + for (i = 0; i < nkeys; i++) { + static struct RSAKey key; + static Bignum challenge; + static char *commentp; + static int commentlen; + + { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i); + logevent(buf); } + p += 4; + p += ssh1_read_bignum(p, &key.exponent); + p += ssh1_read_bignum(p, &key.modulus); + commentlen = GET_32BIT(p); p += 4; + commentp = p; p += commentlen; + send_packet(SSH1_CMSG_AUTH_RSA, + PKT_BIGNUM, key.modulus, PKT_END); + crWaitUntil(ispkt); + if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { + logevent("Key refused"); + continue; + } + logevent("Received RSA challenge"); + ssh1_read_bignum(pktin.body, &challenge); + { + char *agentreq, *q, *ret; + int len, retlen; + len = 1 + 4; /* message type, bit count */ + len += ssh1_bignum_length(key.exponent); + len += ssh1_bignum_length(key.modulus); + len += ssh1_bignum_length(challenge); + len += 16; /* session id */ + len += 4; /* response format */ + agentreq = smalloc(4 + len); + PUT_32BIT(agentreq, len); + q = agentreq + 4; + *q++ = SSH1_AGENTC_RSA_CHALLENGE; + PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus)); + q += 4; + q += ssh1_write_bignum(q, key.exponent); + q += ssh1_write_bignum(q, key.modulus); + q += ssh1_write_bignum(q, challenge); + memcpy(q, session_id, 16); q += 16; + PUT_32BIT(q, 1); /* response format */ + agent_query(agentreq, len+4, &ret, &retlen); + sfree(agentreq); + if (ret) { + if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { + logevent("Sending Pageant's response"); + send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, + PKT_DATA, ret+5, 16, PKT_END); + sfree(ret); + crWaitUntil(ispkt); + if (pktin.type == SSH1_SMSG_SUCCESS) { + logevent("Pageant's response accepted"); + if (flags & FLAG_VERBOSE) { + c_write_str("Authenticated using RSA key \""); + c_write(commentp, commentlen); + c_write_str("\" from agent\r\n"); + } + authed = TRUE; + } else + logevent("Pageant's response not accepted"); + } else { + logevent("Pageant failed to answer challenge"); + sfree(ret); + } + } else { + logevent("No reply received from Pageant"); + } + } + freebn(key.exponent); + freebn(key.modulus); + freebn(challenge); + if (authed) + break; + } + } + if (authed) + break; + } + if (*cfg.keyfile && !tried_publickey) + pwpkt_type = SSH1_CMSG_AUTH_RSA; + + if (pktin.type == SSH1_SMSG_FAILURE && cfg.try_tis_auth && (supported_auths_mask & (1< sizeof(prompt)-1) + challengelen = sizeof(prompt)-1; /* prevent overrun */ + memcpy(prompt, pktin.body+4, challengelen); + prompt[challengelen] = '\0'; + } + } + if (pktin.type == SSH1_SMSG_FAILURE && + cfg.try_tis_auth && + (supported_auths_mask & (1< sizeof(prompt)-1) + challengelen = sizeof(prompt)-1; /* prevent overrun */ + memcpy(prompt, pktin.body+4, challengelen); + strncpy(prompt + challengelen, "\r\nResponse : ", + sizeof(prompt)-challengelen); + prompt[sizeof(prompt)-1] = '\0'; } } - if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) - c_write("password: ", 10); + if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { + sprintf(prompt, "%.90s@%.90s's password: ", + username, savedhost); + } + if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { + char *comment = NULL; + if (flags & FLAG_VERBOSE) + c_write_str("Trying public key authentication.\r\n"); + if (!rsakey_encrypted(cfg.keyfile, &comment)) { + if (flags & FLAG_VERBOSE) + c_write_str("No passphrase required.\r\n"); + goto tryauth; + } + sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); + sfree(comment); + } - pos = 0; - while (pos >= 0) { - crWaitUntil(!ispkt); - while (inlen--) switch (c = *in++) { - case 10: case 13: - password[pos] = 0; - pos = -1; - break; - case 8: case 127: - if (pos > 0) - pos--; - break; - case 21: case 27: - pos = 0; - break; - case 3: case 4: - random_save_seed(); - exit(0); - break; - default: - if (((c >= ' ' && c <= '~') || - ((unsigned char)c >= 160)) && pos < 40) - password[pos++] = c; - break; - } + if (ssh_get_line) { + if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) { + /* + * get_line failed to get a password (for example + * because one was supplied on the command line + * which has already failed to work). Terminate. + */ + logevent("No more passwords to try"); + ssh_state = SSH_STATE_CLOSED; + crReturn(1); + } + } else { + c_write_str(prompt); + pos = 0; + ssh_send_ok = 1; + while (pos >= 0) { + crWaitUntil(!ispkt); + while (inlen--) switch (c = *in++) { + case 10: case 13: + password[pos] = 0; + pos = -1; + break; + case 8: case 127: + if (pos > 0) + pos--; + break; + case 21: case 27: + pos = 0; + break; + case 3: case 4: + random_save_seed(); + exit(0); + break; + default: + if (((c >= ' ' && c <= '~') || + ((unsigned char)c >= 160)) && pos < sizeof(password)) + password[pos++] = c; + break; + } + } + c_write_str("\r\n"); + } + + tryauth: + if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { + /* + * Try public key authentication with the specified + * key file. + */ + static struct RSAKey pubkey; + static Bignum challenge, response; + static int i; + static unsigned char buffer[32]; + + tried_publickey = 1; + i = loadrsakey(cfg.keyfile, &pubkey, password); + if (i == 0) { + c_write_str("Couldn't load public key from "); + c_write_str(cfg.keyfile); + c_write_str(".\r\n"); + continue; /* go and try password */ + } + if (i == -1) { + c_write_str("Wrong passphrase.\r\n"); + tried_publickey = 0; + continue; /* try again */ + } + + /* + * Send a public key attempt. + */ + send_packet(SSH1_CMSG_AUTH_RSA, + PKT_BIGNUM, pubkey.modulus, PKT_END); + + crWaitUntil(ispkt); + if (pktin.type == SSH1_SMSG_FAILURE) { + c_write_str("Server refused our public key.\r\n"); + continue; /* go and try password */ + } + if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { + bombout(("Bizarre response to offer of public key")); + crReturn(0); + } + ssh1_read_bignum(pktin.body, &challenge); + response = rsadecrypt(challenge, &pubkey); + freebn(pubkey.private_exponent); /* burn the evidence */ + + for (i = 0; i < 32; i++) { + buffer[i] = bignum_byte(response, 31-i); + } + + MD5Init(&md5c); + MD5Update(&md5c, buffer, 32); + MD5Update(&md5c, session_id, 16); + MD5Final(buffer, &md5c); + + send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, + PKT_DATA, buffer, 16, PKT_END); + + crWaitUntil(ispkt); + if (pktin.type == SSH1_SMSG_FAILURE) { + if (flags & FLAG_VERBOSE) + c_write_str("Failed to authenticate with our public key.\r\n"); + continue; /* go and try password */ + } else if (pktin.type != SSH1_SMSG_SUCCESS) { + bombout(("Bizarre response to RSA authentication response")); + crReturn(0); + } + + break; /* we're through! */ + } else { + if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { + /* + * Defence against traffic analysis: we send a + * whole bunch of packets containing strings of + * different lengths. One of these strings is the + * password, in a SSH1_CMSG_AUTH_PASSWORD packet. + * The others are all random data in + * SSH1_MSG_IGNORE packets. This way a passive + * listener can't tell which is the password, and + * hence can't deduce the password length. + * + * Anybody with a password length greater than 16 + * bytes is going to have enough entropy in their + * password that a listener won't find it _that_ + * much help to know how long it is. So what we'll + * do is: + * + * - if password length < 16, we send 15 packets + * containing string lengths 1 through 15 + * + * - otherwise, we let N be the nearest multiple + * of 8 below the password length, and send 8 + * packets containing string lengths N through + * N+7. This won't obscure the order of + * magnitude of the password length, but it will + * introduce a bit of extra uncertainty. + * + * A few servers (the old 1.2.18 through 1.2.22) + * can't deal with SSH1_MSG_IGNORE. For these + * servers, we need an alternative defence. We make + * use of the fact that the password is interpreted + * as a C string: so we can append a NUL, then some + * random data. + */ + if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) { + char string[64]; + char *s; + int len; + + len = strlen(password); + if (len < sizeof(string)) { + s = string; + strcpy(string, password); + len++; /* cover the zero byte */ + while (len < sizeof(string)) { + string[len++] = (char)random_byte(); + } + } else { + s = password; + } + send_packet(pwpkt_type, PKT_INT, len, + PKT_DATA, s, len, PKT_END); + } else { + int bottom, top, pwlen, i; + char *randomstr; + + pwlen = strlen(password); + if (pwlen < 16) { + bottom = 0; /* zero length passwords are OK! :-) */ + top = 15; + } else { + bottom = pwlen &~ 7; + top = bottom + 7; + } + + assert(pwlen >= bottom && pwlen <= top); + + randomstr = smalloc(top+1); + + for (i = bottom; i <= top; i++) { + if (i == pwlen) + defer_packet(pwpkt_type, PKT_STR, password, PKT_END); + else { + for (j = 0; j < i; j++) { + do { + randomstr[j] = random_byte(); + } while (randomstr[j] == '\0'); + } + randomstr[i] = '\0'; + defer_packet(SSH1_MSG_IGNORE, + PKT_STR, randomstr, PKT_END); + } + } + ssh_pkt_defersend(); + } + } else { + send_packet(pwpkt_type, PKT_STR, password, PKT_END); + } + } + logevent("Sent password"); + memset(password, 0, strlen(password)); + crWaitUntil(ispkt); + if (pktin.type == SSH1_SMSG_FAILURE) { + if (flags & FLAG_VERBOSE) + c_write_str("Access denied\r\n"); + logevent("Authentication refused"); + } else if (pktin.type == SSH1_MSG_DISCONNECT) { + logevent("Received disconnect request"); + ssh_state = SSH_STATE_CLOSED; + crReturn(1); + } else if (pktin.type != SSH1_SMSG_SUCCESS) { + bombout(("Strange packet received, type %d", pktin.type)); + crReturn(0); + } + } + + logevent("Authentication successful"); + + crFinish(1); +} + +void sshfwd_close(struct ssh_channel *c) { + if (c) { + if (ssh_version == 1) { + send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END); + } else { + ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_send(); + } + c->closes = 1; + if (c->type == CHAN_X11) { + c->u.x11.s = NULL; + logevent("X11 connection terminated"); + } + } +} + +void sshfwd_write(struct ssh_channel *c, char *buf, int len) { + if (ssh_version == 1) { + send_packet(SSH1_MSG_CHANNEL_DATA, + PKT_INT, c->remoteid, + PKT_INT, len, + PKT_DATA, buf, len, + PKT_END); + } else { + ssh2_add_channel_data(c, buf, len); + ssh2_try_send(c); + } +} + +static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { + crBegin; + + random_init(); + + while (!do_ssh1_login(in, inlen, ispkt)) { + crReturnV; + } + if (ssh_state == SSH_STATE_CLOSED) + crReturnV; + + if (cfg.agentfwd && agent_exists()) { + logevent("Requesting agent forwarding"); + send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); + do { crReturnV; } while (!ispkt); + if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crReturnV; + } else if (pktin.type == SSH1_SMSG_FAILURE) { + logevent("Agent forwarding refused"); + } else { + logevent("Agent forwarding enabled"); + ssh_agentfwd_enabled = TRUE; } - c_write("\r\n", 2); + } + if (cfg.x11_forward) { + char proto[20], data[64]; + logevent("Requesting X11 forwarding"); + x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); + send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, + PKT_STR, proto, PKT_STR, data, + PKT_INT, 0, + PKT_END); + do { crReturnV; } while (!ispkt); + if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crReturnV; + } else if (pktin.type == SSH1_SMSG_FAILURE) { + logevent("X11 forwarding refused"); + } else { + logevent("X11 forwarding enabled"); + ssh_X11_fwd_enabled = TRUE; } + } - send_packet(pwpkt_type, PKT_STR, password, PKT_END); - logevent("Sent password"); - memset(password, 0, strlen(password)); - crWaitUntil(ispkt); - if (pktin.type == SSH1_SMSG_FAILURE) { - c_write("Access denied\r\n", 15); - logevent("Authentication refused"); - } else if (pktin.type == SSH1_MSG_DISCONNECT) { - logevent("Received disconnect request"); - ssh_state = SSH_STATE_CLOSED; - crReturn(1); - } else if (pktin.type != SSH1_SMSG_SUCCESS) { - fatalbox("Strange packet received, type %d", pktin.type); + if (!cfg.nopty) { + send_packet(SSH1_CMSG_REQUEST_PTY, + PKT_STR, cfg.termtype, + PKT_INT, rows, PKT_INT, cols, + PKT_INT, 0, PKT_INT, 0, + PKT_CHAR, 0, + PKT_END); + ssh_state = SSH_STATE_INTERMED; + do { crReturnV; } while (!ispkt); + if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crReturnV; + } else if (pktin.type == SSH1_SMSG_FAILURE) { + c_write_str("Server refused to allocate pty\r\n"); + ssh_editing = ssh_echoing = 1; + } + logevent("Allocated pty"); + } else { + ssh_editing = ssh_echoing = 1; + } + + if (cfg.compression) { + send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); + do { crReturnV; } while (!ispkt); + if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crReturnV; + } else if (pktin.type == SSH1_SMSG_FAILURE) { + c_write_str("Server refused to compress\r\n"); + } + logevent("Started compression"); + ssh1_compressing = TRUE; + zlib_compress_init(); + zlib_decompress_init(); + } + + if (*cfg.remote_cmd) + send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END); + else + send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); + logevent("Started session"); + + ssh_state = SSH_STATE_SESSION; + if (size_needed) + ssh_size(); + if (eof_needed) + ssh_special(TS_EOF); + + ldisc_send(NULL, 0); /* cause ldisc to notice changes */ + ssh_send_ok = 1; + ssh_channels = newtree234(ssh_channelcmp); + while (1) { + crReturnV; + if (ispkt) { + if (pktin.type == SSH1_SMSG_STDOUT_DATA || + pktin.type == SSH1_SMSG_STDERR_DATA) { + long len = GET_32BIT(pktin.body); + from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, + pktin.body+4, len); + } else if (pktin.type == SSH1_MSG_DISCONNECT) { + ssh_state = SSH_STATE_CLOSED; + logevent("Received disconnect request"); + crReturnV; + } 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. */ + unsigned i; + struct ssh_channel *c, *d; + enum234 e; + + logevent("Received X11 connect request"); + /* Refuse if X11 forwarding is disabled. */ + if (!ssh_X11_fwd_enabled) { + send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, GET_32BIT(pktin.body), + PKT_END); + logevent("Rejected X11 connect request"); + } else { + c = smalloc(sizeof(struct ssh_channel)); + + if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) { + logevent("opening X11 forward connection failed"); + sfree(c); + send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, GET_32BIT(pktin.body), + PKT_END); + } else { + logevent("opening X11 forward connection succeeded"); + for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) { + if (d->localid > i) + break; /* found a free number */ + i = d->localid + 1; + } + c->remoteid = GET_32BIT(pktin.body); + c->localid = i; + c->closes = 0; + c->type = CHAN_X11; /* identify channel type */ + add234(ssh_channels, c); + send_packet(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. */ + unsigned i; + struct ssh_channel *c; + enum234 e; + + /* Refuse if agent forwarding is disabled. */ + if (!ssh_agentfwd_enabled) { + send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, GET_32BIT(pktin.body), + PKT_END); + } else { + i = 1; + for (c = first234(ssh_channels, &e); c; c = next234(&e)) { + if (c->localid > i) + break; /* found a free number */ + i = c->localid + 1; + } + c = smalloc(sizeof(struct ssh_channel)); + c->remoteid = GET_32BIT(pktin.body); + c->localid = i; + c->closes = 0; + c->type = CHAN_AGENT; /* identify channel type */ + c->u.a.lensofar = 0; + add234(ssh_channels, c); + send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, + PKT_INT, c->remoteid, PKT_INT, c->localid, + PKT_END); + } + } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE || + pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { + /* Remote side closes a channel. */ + unsigned i = GET_32BIT(pktin.body); + struct ssh_channel *c; + c = find234(ssh_channels, &i, ssh_channelfind); + if (c) { + int closetype; + closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); + send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END); + if ((c->closes == 0) && (c->type == CHAN_X11)) { + logevent("X11 connection closed"); + assert(c->u.x11.s != NULL); + x11_close(c->u.x11.s); + c->u.x11.s = NULL; + } + c->closes |= closetype; + if (c->closes == 3) { + del234(ssh_channels, c); + sfree(c); + } + } + } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { + /* Data sent down one of our channels. */ + int i = GET_32BIT(pktin.body); + int len = GET_32BIT(pktin.body+4); + unsigned char *p = pktin.body+8; + struct ssh_channel *c; + c = find234(ssh_channels, &i, ssh_channelfind); + if (c) { + switch(c->type) { + case CHAN_X11: + x11_send(c->u.x11.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 = smalloc(c->u.a.totallen); + 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, *sentreply; + int replylen; + agent_query(c->u.a.message, c->u.a.totallen, + &reply, &replylen); + if (reply) + sentreply = reply; + else { + /* Fake SSH_AGENT_FAILURE. */ + sentreply = "\0\0\0\1\5"; + replylen = 5; + } + send_packet(SSH1_MSG_CHANNEL_DATA, + PKT_INT, c->remoteid, + PKT_INT, replylen, + PKT_DATA, sentreply, replylen, + PKT_END); + if (reply) + sfree(reply); + sfree(c->u.a.message); + c->u.a.lensofar = 0; + } + } + break; + } + } + } else 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) { + send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); + } else { + bombout(("Strange packet received: type %d", pktin.type)); + crReturnV; + } + } else { + while (inlen > 0) { + int len = min(inlen, 512); + send_packet(SSH1_CMSG_STDIN_DATA, + PKT_INT, len, PKT_DATA, in, len, PKT_END); + in += len; + inlen -= len; + } } } - logevent("Authentication successful"); + crFinishV; +} - crFinish(1); +/* + * Utility routine for decoding comma-separated strings in KEXINIT. + */ +static int in_commasep_string(char *needle, char *haystack, int haylen) { + int needlen = strlen(needle); + while (1) { + /* + * 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; + /* + * If not, search for the next comma and resume after that. + * If no comma found, terminate. + */ + while (haylen > 0 && *haystack != ',') + haylen--, haystack++; + if (haylen == 0) + return 0; + haylen--, haystack++; /* skip over comma itself */ + } } -static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { - crBegin; +/* + * SSH2 key creation method. + */ +static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) { + SHA_State s; + /* First 20 bytes. */ + SHA_Init(&s); + 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); + sha_mpint(&s, K); + SHA_Bytes(&s, H, 20); + SHA_Bytes(&s, keyspace, 20); + SHA_Final(&s, keyspace+20); +} + +/* + * Handle the SSH2 transport layer. + */ +static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) +{ + static int i, j, len, nbits, pbits; + static char *str; + static Bignum p, g, e, f, K; + static int kex_init_value, kex_reply_value; + static const struct ssh_mac **maclist; + static int nmacs; + static const struct ssh2_cipher *cscipher_tobe = NULL; + static const struct ssh2_cipher *sccipher_tobe = NULL; + static const struct ssh_mac *csmac_tobe = NULL; + static const struct ssh_mac *scmac_tobe = NULL; + static const struct ssh_compress *cscomp_tobe = NULL; + static const struct ssh_compress *sccomp_tobe = NULL; + static char *hostkeydata, *sigdata, *keystr, *fingerprint; + static int hostkeylen, siglen; + static void *hkey; /* actual host key */ + static unsigned char exchange_hash[20]; + static unsigned char keyspace[40]; + static const struct ssh2_ciphers *preferred_cipher; + static const struct ssh_compress *preferred_comp; + static int first_kex; + crBegin; random_init(); + first_kex = 1; - while (!do_ssh1_login(in, inlen, ispkt)) { - crReturnV; + /* + * Set up the preferred cipher and compression. + */ + if (cfg.cipher == CIPHER_BLOWFISH) { + preferred_cipher = &ssh2_blowfish; + } else if (cfg.cipher == CIPHER_DES) { + logevent("Single DES not supported in SSH2; using 3DES"); + preferred_cipher = &ssh2_3des; + } else if (cfg.cipher == CIPHER_3DES) { + preferred_cipher = &ssh2_3des; + } else if (cfg.cipher == CIPHER_AES) { + preferred_cipher = &ssh2_aes; + } else { + /* Shouldn't happen, but we do want to initialise to _something_. */ + preferred_cipher = &ssh2_3des; + } + if (cfg.compression) + preferred_comp = &ssh_zlib; + else + preferred_comp = &ssh_comp_none; + + /* + * Be prepared to work around the buggy MAC problem. + */ + if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC)) + maclist = buggymacs, nmacs = lenof(buggymacs); + else + maclist = macs, nmacs = lenof(macs); + + begin_key_exchange: + /* + * Construct and send our key exchange packet. + */ + ssh2_pkt_init(SSH2_MSG_KEXINIT); + for (i = 0; i < 16; i++) + ssh2_pkt_addbyte((unsigned char)random_byte()); + /* List key exchange algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < lenof(kex_algs); i++) { + ssh2_pkt_addstring_str(kex_algs[i]->name); + if (i < lenof(kex_algs)-1) + ssh2_pkt_addstring_str(","); + } + /* List server host key algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < lenof(hostkey_algs); i++) { + ssh2_pkt_addstring_str(hostkey_algs[i]->name); + if (i < lenof(hostkey_algs)-1) + ssh2_pkt_addstring_str(","); + } + /* List client->server encryption algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < lenof(ciphers)+1; i++) { + const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; + for (j = 0; j < c->nciphers; j++) { + ssh2_pkt_addstring_str(c->list[j]->name); + if (i < lenof(ciphers) || j < c->nciphers-1) + ssh2_pkt_addstring_str(","); + } + } + /* List server->client encryption algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < lenof(ciphers)+1; i++) { + const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; + for (j = 0; j < c->nciphers; j++) { + ssh2_pkt_addstring_str(c->list[j]->name); + if (i < lenof(ciphers) || j < c->nciphers-1) + ssh2_pkt_addstring_str(","); + } + } + /* List client->server MAC algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < nmacs; i++) { + ssh2_pkt_addstring_str(maclist[i]->name); + if (i < nmacs-1) + ssh2_pkt_addstring_str(","); + } + /* List server->client MAC algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < nmacs; i++) { + ssh2_pkt_addstring_str(maclist[i]->name); + if (i < nmacs-1) + ssh2_pkt_addstring_str(","); + } + /* List client->server compression algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < lenof(compressions)+1; i++) { + const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; + ssh2_pkt_addstring_str(c->name); + if (i < lenof(compressions)) + ssh2_pkt_addstring_str(","); + } + /* List server->client compression algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < lenof(compressions)+1; i++) { + const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; + ssh2_pkt_addstring_str(c->name); + if (i < lenof(compressions)) + ssh2_pkt_addstring_str(","); + } + /* List client->server languages. Empty list. */ + ssh2_pkt_addstring_start(); + /* List server->client languages. Empty list. */ + ssh2_pkt_addstring_start(); + /* First KEX packet does _not_ follow, because we're not that brave. */ + ssh2_pkt_addbool(FALSE); + /* Reserved. */ + ssh2_pkt_adduint32(0); + + exhash = exhashbase; + sha_string(&exhash, pktout.data+5, pktout.length-5); + + ssh2_pkt_send(); + + if (!ispkt) crWaitUntil(ispkt); + sha_string(&exhash, pktin.data+5, pktin.length-5); + + /* + * Now examine the other side's KEXINIT to see what we're up + * to. + */ + if (pktin.type != SSH2_MSG_KEXINIT) { + bombout(("expected key exchange packet from server")); + crReturn(0); + } + kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL; + csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL; + pktin.savedpos += 16; /* skip garbage cookie */ + ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ + for (i = 0; i < lenof(kex_algs); i++) { + if (in_commasep_string(kex_algs[i]->name, str, len)) { + kex = kex_algs[i]; + break; + } + } + ssh2_pkt_getstring(&str, &len); /* host key algorithms */ + for (i = 0; i < lenof(hostkey_algs); i++) { + if (in_commasep_string(hostkey_algs[i]->name, str, len)) { + hostkey = hostkey_algs[i]; + break; + } + } + ssh2_pkt_getstring(&str, &len); /* client->server cipher */ + for (i = 0; i < lenof(ciphers)+1; i++) { + const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; + for (j = 0; j < c->nciphers; j++) { + if (in_commasep_string(c->list[j]->name, str, len)) { + cscipher_tobe = c->list[j]; + break; + } + } + if (cscipher_tobe) + break; + } + ssh2_pkt_getstring(&str, &len); /* server->client cipher */ + for (i = 0; i < lenof(ciphers)+1; i++) { + const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; + for (j = 0; j < c->nciphers; j++) { + if (in_commasep_string(c->list[j]->name, str, len)) { + sccipher_tobe = c->list[j]; + break; + } + } + if (sccipher_tobe) + break; + } + ssh2_pkt_getstring(&str, &len); /* client->server mac */ + for (i = 0; i < nmacs; i++) { + if (in_commasep_string(maclist[i]->name, str, len)) { + csmac_tobe = maclist[i]; + break; + } + } + ssh2_pkt_getstring(&str, &len); /* server->client mac */ + for (i = 0; i < nmacs; i++) { + if (in_commasep_string(maclist[i]->name, str, len)) { + scmac_tobe = maclist[i]; + break; + } + } + ssh2_pkt_getstring(&str, &len); /* client->server compression */ + for (i = 0; i < lenof(compressions)+1; i++) { + const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; + if (in_commasep_string(c->name, str, len)) { + cscomp_tobe = c; + break; + } + } + ssh2_pkt_getstring(&str, &len); /* server->client compression */ + for (i = 0; i < lenof(compressions)+1; i++) { + const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; + if (in_commasep_string(c->name, str, len)) { + sccomp_tobe = c; + break; + } + } + + /* + * Work out the number of bits of key we will need from the key + * exchange. We start with the maximum key length of either + * cipher... + */ + { + int csbits, scbits; + + csbits = cscipher_tobe->keylen; + scbits = sccipher_tobe->keylen; + 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 (nbits > 160) nbits = 160; + + /* + * If we're doing Diffie-Hellman group exchange, start by + * requesting a group. + */ + if (kex == &ssh_diffiehellman_gex) { + logevent("Doing Diffie-Hellman group exchange"); + /* + * Work out how big a DH group we will need to allow that + * much data. + */ + pbits = 512 << ((nbits-1) / 64); + ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); + ssh2_pkt_adduint32(pbits); + ssh2_pkt_send(); + + crWaitUntil(ispkt); + if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) { + bombout(("expected key exchange group packet from server")); + crReturn(0); + } + p = ssh2_pkt_getmp(); + g = ssh2_pkt_getmp(); + dh_setup_group(p, g); + kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; + kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; + } else { + dh_setup_group1(); + kex_init_value = SSH2_MSG_KEXDH_INIT; + kex_reply_value = SSH2_MSG_KEXDH_REPLY; + } + + logevent("Doing Diffie-Hellman key exchange"); + /* + * Now generate and send e for Diffie-Hellman. + */ + e = dh_create_e(nbits*2); + ssh2_pkt_init(kex_init_value); + ssh2_pkt_addmp(e); + ssh2_pkt_send(); + + crWaitUntil(ispkt); + if (pktin.type != kex_reply_value) { + bombout(("expected key exchange reply packet from server")); + crReturn(0); } - if (ssh_state == SSH_STATE_CLOSED) - crReturnV; + ssh2_pkt_getstring(&hostkeydata, &hostkeylen); + f = ssh2_pkt_getmp(); + ssh2_pkt_getstring(&sigdata, &siglen); - if (!cfg.nopty) { - send_packet(SSH1_CMSG_REQUEST_PTY, - PKT_STR, cfg.termtype, - PKT_INT, rows, PKT_INT, cols, - PKT_INT, 0, PKT_INT, 0, - PKT_CHAR, 0, - PKT_END); - ssh_state = SSH_STATE_INTERMED; - do { crReturnV; } while (!ispkt); - if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { - fatalbox("Protocol confusion"); - } else if (pktin.type == SSH1_SMSG_FAILURE) { - c_write("Server refused to allocate pty\r\n", 32); - } - logevent("Allocated pty"); + K = dh_find_K(f); + + sha_string(&exhash, hostkeydata, hostkeylen); + if (kex == &ssh_diffiehellman_gex) { + sha_uint32(&exhash, pbits); + sha_mpint(&exhash, p); + sha_mpint(&exhash, g); } + sha_mpint(&exhash, e); + sha_mpint(&exhash, f); + sha_mpint(&exhash, K); + SHA_Final(&exhash, exchange_hash); - send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); - logevent("Started session"); + dh_cleanup(); - ssh_state = SSH_STATE_SESSION; - if (size_needed) - ssh_size(); +#if 0 + debug(("Exchange hash is:\r\n")); + for (i = 0; i < 20; i++) + debug((" %02x", exchange_hash[i])); + debug(("\r\n")); +#endif - while (1) { - crReturnV; - if (ispkt) { - if (pktin.type == SSH1_SMSG_STDOUT_DATA || - pktin.type == SSH1_SMSG_STDERR_DATA) { - long len = GET_32BIT(pktin.body); - c_write(pktin.body+4, len); - } else if (pktin.type == SSH1_MSG_DISCONNECT) { - ssh_state = SSH_STATE_CLOSED; - logevent("Received disconnect request"); - } else 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) { - send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); - } else { - fatalbox("Strange packet received: type %d", pktin.type); - } - } else { - send_packet(SSH1_CMSG_STDIN_DATA, - PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END); - } + hkey = hostkey->newkey(hostkeydata, hostkeylen); + if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { + bombout(("Server failed host key check")); + crReturn(0); } - crFinishV; -} + /* + * Expect SSH2_MSG_NEWKEYS from server. + */ + crWaitUntil(ispkt); + if (pktin.type != SSH2_MSG_NEWKEYS) { + bombout(("expected new-keys packet from server")); + crReturn(0); + } -/* - * SSH2 packet construction functions. - */ -void ssh2_pkt_adddata(void *data, int len) { - pktout.length += len; - if (pktout.maxlen < pktout.length) { - pktout.maxlen = pktout.length + 256; - pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) : - realloc(pktout.data, pktout.maxlen+APIEXTRA)); - if (!pktout.data) - fatalbox("Out of memory"); + /* + * Authenticate remote host: verify host key. (We've already + * checked the signature of the exchange hash.) + */ + keystr = hostkey->fmtkey(hkey); + fingerprint = hostkey->fingerprint(hkey); + verify_ssh_host_key(savedhost, savedport, hostkey->keytype, + keystr, fingerprint); + if (first_kex) { /* don't bother logging this in rekeys */ + logevent("Host key fingerprint is:"); + logevent(fingerprint); } - memcpy(pktout.data+pktout.length-len, data, len); -} -void ssh2_pkt_addbyte(unsigned char byte) { - ssh2_pkt_adddata(&byte, 1); -} -void ssh2_pkt_init(int pkt_type) { - pktout.length = 5; - ssh2_pkt_addbyte((unsigned char)pkt_type); -} -void ssh2_pkt_addbool(unsigned char value) { - ssh2_pkt_adddata(&value, 1); -} -void ssh2_pkt_adduint32(unsigned long value) { - unsigned char x[4]; - PUT_32BIT(x, value); - ssh2_pkt_adddata(x, 4); -} -void ssh2_pkt_addstring_start(void) { - ssh2_pkt_adduint32(0); - pktout.savedpos = pktout.length; -} -void ssh2_pkt_addstring_str(char *data) { - ssh2_pkt_adddata(data, strlen(data)); - PUT_32BIT(pktout.data + pktout.savedpos - 4, - pktout.length - pktout.savedpos); -} -void ssh2_pkt_addstring_data(char *data, int len) { - ssh2_pkt_adddata(data, len); - PUT_32BIT(pktout.data + pktout.savedpos - 4, - pktout.length - pktout.savedpos); -} -void ssh2_pkt_addstring(char *data) { - ssh2_pkt_addstring_start(); - ssh2_pkt_addstring_str(data); -} -char *ssh2_mpint_fmt(Bignum b, int *len) { - unsigned char *p; - int i, n = b[0]; - p = malloc(n * 2 + 1); - if (!p) - fatalbox("out of memory"); - p[0] = 0; - for (i = 0; i < n; i++) { - p[i*2+1] = (b[n-i] >> 8) & 0xFF; - p[i*2+2] = (b[n-i] ) & 0xFF; + sfree(fingerprint); + sfree(keystr); + hostkey->freekey(hkey); + + /* + * Send SSH2_MSG_NEWKEYS. + */ + ssh2_pkt_init(SSH2_MSG_NEWKEYS); + ssh2_pkt_send(); + + /* + * Create and initialise session keys. + */ + cscipher = cscipher_tobe; + sccipher = sccipher_tobe; + csmac = csmac_tobe; + scmac = scmac_tobe; + cscomp = cscomp_tobe; + sccomp = sccomp_tobe; + cscomp->compress_init(); + sccomp->decompress_init(); + /* + * Set IVs after keys. Here we use the exchange hash from the + * _first_ key exchange. + */ + if (first_kex) + memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash)); + ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace); + cscipher->setcskey(keyspace); + ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace); + sccipher->setsckey(keyspace); + ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace); + cscipher->setcsiv(keyspace); + ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace); + sccipher->setsciv(keyspace); + ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace); + csmac->setcskey(keyspace); + ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace); + scmac->setsckey(keyspace); + + /* + * If this is the first key exchange phase, we must pass the + * SSH2_MSG_NEWKEYS packet to the next layer, not because it + * wants to see it but because it will need time to initialise + * itself before it sees an actual packet. In subsequent key + * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because + * it would only confuse the layer above. + */ + if (!first_kex) { + crReturn(0); } - i = 0; - while (p[i] == 0 && (p[i+1] & 0x80) == 0) - i++; - memmove(p, p+i, n*2+1-i); - *len = n*2+1-i; - return p; -} -void ssh2_pkt_addmp(Bignum b) { - unsigned char *p; - int len; - p = ssh2_mpint_fmt(b, &len); - ssh2_pkt_addstring_start(); - ssh2_pkt_addstring_data(p, len); - free(p); -} -void ssh2_pkt_send(void) { - int cipherblk, maclen, padding, i; - unsigned long outgoing_sequence = 0; + first_kex = 0; /* - * Add padding. At least four bytes, and must also bring total - * length (minus MAC) up to a multiple of the block size. + * 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. */ - cipherblk = cipher ? cipher->blksize : 8; /* block size */ - cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ - padding = 4; - padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; - pktout.data[4] = padding; - for (i = 0; i < padding; i++) - pktout.data[pktout.length + i] = random_byte(); - PUT_32BIT(pktout.data, pktout.length + padding - 4); - if (csmac) - csmac->generate(pktout.data, outgoing_sequence++, - pktout.length + padding); - if (cscipher) - cscipher->encrypt(pktout.data, pktout.length + padding); - maclen = csmac ? csmac->len : 0; -#if 0 - debug(("Sending packet len=%d\r\n", pktout.length+padding+maclen)); - for (i = 0; i < pktout.length+padding+maclen; i++) - debug((" %02x", (unsigned char)pktout.data[i])); - debug(("\r\n")); -#endif - s_write(pktout.data, pktout.length + padding + maclen); -} + while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) { + crReturn(1); + } + logevent("Server initiated key re-exchange"); + goto begin_key_exchange; -void sha_mpint(SHA_State *s, Bignum b) { - unsigned char *p; - int len; - p = ssh2_mpint_fmt(b, &len); - sha_string(s, p, len); - free(p); + crFinish(1); } /* - * SSH2 packet decode functions. + * Add data to an SSH2 channel output buffer. */ -void ssh2_pkt_getstring(char **p, int *length) { - *p = NULL; - if (pktin.length - pktin.savedpos < 4) - return; - *length = GET_32BIT(pktin.data+pktin.savedpos); - pktin.savedpos += 4; - if (pktin.length - pktin.savedpos < *length) - return; - *p = pktin.data+pktin.savedpos; - pktin.savedpos += *length; -} -Bignum ssh2_pkt_getmp(void) { - char *p; - int i, j, length; - Bignum b; - - ssh2_pkt_getstring(&p, &length); - if (!p) - return NULL; - if (p[0] & 0x80) - fatalbox("internal error: Can't handle negative mpints"); - b = newbn((length+1)/2); - for (i = 0; i < length; i++) { - j = length - 1 - i; - if (j & 1) - b[j/2+1] |= ((unsigned char)p[i]) << 8; - else - b[j/2+1] |= ((unsigned char)p[i]); +static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) { + if (c->v2.outbufsize < + c->v2.outbuflen + len) { + c->v2.outbufsize = + c->v2.outbuflen + len + 1024; + c->v2.outbuffer = srealloc(c->v2.outbuffer, + c->v2.outbufsize); } - return b; -} - -void bndebug(char *string, Bignum b) { - unsigned char *p; - int i, len; - p = ssh2_mpint_fmt(b, &len); - debug(("%s", string)); - for (i = 0; i < len; i++) - debug((" %02x", p[i])); - debug(("\r\n")); - free(p); + memcpy(c->v2.outbuffer + c->v2.outbuflen, + buf, len); + c->v2.outbuflen += len; } /* - * Utility routine for decoding comma-separated strings in KEXINIT. + * Attempt to send data on an SSH2 channel. */ -int in_commasep_string(char *needle, char *haystack, int haylen) { - int needlen = strlen(needle); - while (1) { - /* - * 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; - /* - * If not, search for the next comma and resume after that. - * If no comma found, terminate. - */ - while (haylen > 0 && *haystack != ',') - haylen--, haystack++; - if (haylen == 0) - return 0; - haylen--, haystack++; /* skip over comma itself */ +static void ssh2_try_send(struct ssh_channel *c) { + while (c->v2.remwindow > 0 && + c->v2.outbuflen > 0) { + unsigned len = c->v2.remwindow; + if (len > c->v2.outbuflen) + len = c->v2.outbuflen; + if (len > c->v2.remmaxpkt) + len = c->v2.remmaxpkt; + ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(c->v2.outbuffer, len); + ssh2_pkt_send(); + c->v2.outbuflen -= len; + memmove(c->v2.outbuffer, c->v2.outbuffer+len, + c->v2.outbuflen); + c->v2.remwindow -= len; } } /* - * Handle the SSH2 key exchange phase. + * Handle the SSH2 userauth and connection layers. */ -static int do_ssh2_kex(unsigned char *in, int inlen, int ispkt) +static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) { - static int i, len; - static char *str; - static Bignum e, f, K; - static struct ssh_cipher *cscipher_tobe = NULL; - static struct ssh_cipher *sccipher_tobe = NULL; - static struct ssh_mac *csmac_tobe = NULL; - static struct ssh_mac *scmac_tobe = NULL; - static struct ssh_compress *cscomp_tobe = NULL; - static struct ssh_compress *sccomp_tobe = NULL; - static char *hostkeydata, *sigdata; - static int hostkeylen, siglen; - static unsigned char exchange_hash[20]; + static unsigned long remote_winsize; + static unsigned long remote_maxpkt; + static enum { + AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD + } method; + static enum { + AUTH_TYPE_NONE, + AUTH_TYPE_PUBLICKEY, + AUTH_TYPE_PUBLICKEY_OFFER_LOUD, + AUTH_TYPE_PUBLICKEY_OFFER_QUIET, + AUTH_TYPE_PASSWORD + } type; + static int gotit, need_pw, can_pubkey, can_passwd; + static int tried_pubkey_config, tried_agent; + static int we_are_in; + static char username[100]; + static char pwprompt[200]; + static char password[100]; + + crBegin; + + /* + * Request userauth protocol, and await a response to it. + */ + ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); + ssh2_pkt_addstring("ssh-userauth"); + ssh2_pkt_send(); + crWaitUntilV(ispkt); + if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) { + bombout(("Server refused user authentication protocol")); + crReturnV; + } + + /* + * We repeat this whole loop, including the username prompt, + * until we manage a successful authentication. If the user + * types the wrong _password_, they are sent back to the + * beginning to try another username. (If they specify a + * username in the config, they are never asked, even if they + * do give a wrong password.) + * + * I think this best serves the needs of + * + * - the people who have no configuration, no keys, and just + * want to try repeated (username,password) pairs until they + * type both correctly + * + * - people who have keys and configuration but occasionally + * need to fall back to passwords + * + * - people with a key held in Pageant, who might not have + * logged in to a particular machine before; so they want to + * type a username, and then _either_ their key will be + * accepted, _or_ they will type a password. If they mistype + * the username they will want to be able to get back and + * retype it! + */ + do { + static int pos; + static char c; + + /* + * Get a username. + */ + pos = 0; + if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { + if (ssh_get_line) { + if (!ssh_get_line("login as: ", + username, sizeof(username), FALSE)) { + /* + * get_line failed to get a username. + * Terminate. + */ + logevent("No username provided. Abandoning session."); + ssh_state = SSH_STATE_CLOSED; + crReturn(1); + } + } else { + c_write_str("login as: "); + ssh_send_ok = 1; + while (pos >= 0) { + crWaitUntilV(!ispkt); + while (inlen--) switch (c = *in++) { + case 10: case 13: + username[pos] = 0; + pos = -1; + break; + case 8: case 127: + if (pos > 0) { + c_write_str("\b \b"); + pos--; + } + break; + case 21: case 27: + while (pos > 0) { + c_write_str("\b \b"); + pos--; + } + break; + case 3: case 4: + random_save_seed(); + exit(0); + break; + default: + if (((c >= ' ' && c <= '~') || + ((unsigned char)c >= 160)) && pos < 40) { + username[pos++] = c; + c_write(&c, 1); + } + break; + } + } + } + c_write_str("\r\n"); + username[strcspn(username, "\n\r")] = '\0'; + } else { + char stuff[200]; + strncpy(username, cfg.username, 99); + username[99] = '\0'; + if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { + sprintf(stuff, "Using username \"%s\".\r\n", username); + c_write_str(stuff); + } + } + + /* + * Send an authentication request using method "none": (a) + * just in case it succeeds, and (b) so that we know what + * authentication methods we can usefully try next. + */ + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("none"); /* method */ + ssh2_pkt_send(); + type = AUTH_TYPE_NONE; + gotit = FALSE; + we_are_in = FALSE; + + tried_pubkey_config = FALSE; + tried_agent = FALSE; + + while (1) { + /* + * Wait for the result of the last authentication request. + */ + if (!gotit) + crWaitUntilV(ispkt); + while (pktin.type == SSH2_MSG_USERAUTH_BANNER) { + /* FIXME: should support this */ + crWaitUntilV(ispkt); + } + if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { + logevent("Access granted"); + we_are_in = TRUE; + break; + } + + if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) { + bombout(("Strange packet received during authentication: type %d", + pktin.type)); + } + + gotit = FALSE; + + /* + * OK, we're now sitting on a USERAUTH_FAILURE message, so + * we can look at the string in it and know what we can + * helpfully try next. + */ + { + char *methods; + int methlen; + ssh2_pkt_getstring(&methods, &methlen); + if (!ssh2_pkt_getbool()) { + /* + * We have received an unequivocal Access + * Denied. This can translate to a variety of + * messages: + * + * - if we'd just tried "none" authentication, + * it's not worth printing anything at all + * + * - if we'd just tried a public key _offer_, + * the message should be "Server refused our + * key" (or no message at all if the key + * came from Pageant) + * + * - if we'd just tried anything else, the + * message really should be "Access denied". + * + * Additionally, if we'd just tried password + * authentication, we should break out of this + * whole loop so as to go back to the username + * prompt. + */ + if (type == AUTH_TYPE_NONE) { + /* do nothing */ + } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || + type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { + if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) + c_write_str("Server refused our key\r\n"); + logevent("Server refused public key"); + } else { + c_write_str("Access denied\r\n"); + logevent("Access denied"); + if (type == AUTH_TYPE_PASSWORD) { + we_are_in = FALSE; + break; + } + } + } else { + c_write_str("Further authentication required\r\n"); + logevent("Further authentication required"); + } + + can_pubkey = in_commasep_string("publickey", methods, methlen); + can_passwd = in_commasep_string("password", methods, methlen); + } + + method = 0; + + if (!method && can_pubkey && agent_exists && !tried_agent) { + /* + * Attempt public-key authentication using Pageant. + */ + static unsigned char request[5], *response, *p; + static int responselen; + static int i, nkeys; + static int authed = FALSE; + void *r; + + tried_agent = TRUE; + + logevent("Pageant is running. Requesting keys."); + + /* Request the keys held by the agent. */ + PUT_32BIT(request, 1); + request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; + agent_query(request, 5, &r, &responselen); + response = (unsigned char *)r; + if (response) { + p = response + 5; + nkeys = GET_32BIT(p); p += 4; + { char buf[64]; sprintf(buf, "Pageant has %d SSH2 keys", nkeys); + logevent(buf); } + for (i = 0; i < nkeys; i++) { + static char *pkblob, *alg, *commentp; + static int pklen, alglen, commentlen; + static int siglen, retlen, len; + static char *q, *agentreq, *ret; + + { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i); + logevent(buf); } + pklen = GET_32BIT(p); p += 4; + pkblob = p; p += pklen; + alglen = GET_32BIT(pkblob); + alg = pkblob + 4; + commentlen = GET_32BIT(p); p += 4; + commentp = p; p += commentlen; + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection");/* service requested */ + ssh2_pkt_addstring("publickey");/* method */ + ssh2_pkt_addbool(FALSE); /* no signature included */ + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(alg, alglen); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(pkblob, pklen); + ssh2_pkt_send(); + + crWaitUntilV(ispkt); + if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { + logevent("Key refused"); + continue; + } + + c_write_str("Authenticating with public key \""); + c_write(commentp, commentlen); + c_write_str("\" from agent\r\n"); + + /* + * Server is willing to accept the key. + * Construct a SIGN_REQUEST. + */ + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("publickey"); /* method */ + ssh2_pkt_addbool(TRUE); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(alg, alglen); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(pkblob, pklen); + + siglen = pktout.length - 5 + 4 + 20; + len = 1; /* message type */ + len += 4 + pklen; /* key blob */ + len += 4 + siglen; /* data to sign */ + len += 4; /* flags */ + agentreq = smalloc(4 + len); + PUT_32BIT(agentreq, len); + q = agentreq + 4; + *q++ = SSH2_AGENTC_SIGN_REQUEST; + PUT_32BIT(q, pklen); q += 4; + memcpy(q, pkblob, pklen); q += pklen; + PUT_32BIT(q, siglen); q += 4; + /* Now the data to be signed... */ + PUT_32BIT(q, 20); q += 4; + memcpy(q, ssh2_session_id, 20); q += 20; + memcpy(q, pktout.data+5, pktout.length-5); + q += pktout.length-5; + /* And finally the (zero) flags word. */ + PUT_32BIT(q, 0); + agent_query(agentreq, len+4, &ret, &retlen); + sfree(agentreq); + if (ret) { + if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) { + logevent("Sending Pageant's response"); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5)); + ssh2_pkt_send(); + authed = TRUE; + break; + } else { + logevent("Pageant failed to answer challenge"); + sfree(ret); + } + } + } + if (authed) + continue; + } + } + + if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) { + unsigned char *pub_blob; + char *algorithm, *comment; + int pub_blob_len; + + tried_pubkey_config = TRUE; + + /* + * Try the public key supplied in the configuration. + * + * First, offer the public blob to see if the server is + * willing to accept it. + */ + pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm, + &pub_blob_len); + if (pub_blob) { + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("publickey");/* method */ + ssh2_pkt_addbool(FALSE); /* no signature included */ + ssh2_pkt_addstring(algorithm); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(pub_blob, pub_blob_len); + ssh2_pkt_send(); + logevent("Offered public key"); /* FIXME */ + + crWaitUntilV(ispkt); + if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { + gotit = TRUE; + type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; + continue; /* key refused; give up on it */ + } + + logevent("Offer of public key accepted"); + /* + * Actually attempt a serious authentication using + * the key. + */ + if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) { + sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment); + need_pw = TRUE; + } else { + need_pw = FALSE; + } + c_write_str("Authenticating with public key \""); + c_write_str(comment); + c_write_str("\"\r\n"); + method = AUTH_PUBLICKEY_FILE; + } + } + + if (!method && can_passwd) { + method = AUTH_PASSWORD; + sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost); + need_pw = TRUE; + } + + if (need_pw) { + if (ssh_get_line) { + if (!ssh_get_line(pwprompt, password, + sizeof(password), TRUE)) { + /* + * get_line failed to get a password (for + * example because one was supplied on the + * command line which has already failed to + * work). Terminate. + */ + logevent("No more passwords to try"); + ssh_state = SSH_STATE_CLOSED; + crReturnV; + } + } else { + static int pos = 0; + static char c; + + c_write_str(pwprompt); + ssh_send_ok = 1; + + pos = 0; + while (pos >= 0) { + crWaitUntilV(!ispkt); + while (inlen--) switch (c = *in++) { + case 10: case 13: + password[pos] = 0; + pos = -1; + break; + case 8: case 127: + if (pos > 0) + pos--; + break; + case 21: case 27: + pos = 0; + break; + case 3: case 4: + random_save_seed(); + exit(0); + break; + default: + if (((c >= ' ' && c <= '~') || + ((unsigned char)c >= 160)) && pos < 40) + password[pos++] = c; + break; + } + } + c_write_str("\r\n"); + } + } + + if (method == AUTH_PUBLICKEY_FILE) { + /* + * We have our passphrase. Now try the actual authentication. + */ + struct ssh2_userkey *key; + + key = ssh2_load_userkey(cfg.keyfile, password); + if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { + if (key == SSH2_WRONG_PASSPHRASE) { + c_write_str("Wrong passphrase\r\n"); + tried_pubkey_config = FALSE; + } else { + c_write_str("Unable to load private key\r\n"); + tried_pubkey_config = TRUE; + } + /* Send a spurious AUTH_NONE to return to the top. */ + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("none"); /* method */ + ssh2_pkt_send(); + type = AUTH_TYPE_NONE; + } else { + unsigned char *blob, *sigdata; + int blob_len, sigdata_len; + + /* + * We have loaded the private key and the server + * has announced that it's willing to accept it. + * Hallelujah. Generate a signature and send it. + */ + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("publickey"); /* method */ + ssh2_pkt_addbool(TRUE); + ssh2_pkt_addstring(key->alg->name); + blob = key->alg->public_blob(key->data, &blob_len); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(blob, blob_len); + sfree(blob); + + /* + * The data to be signed is: + * + * string session-id + * + * followed by everything so far placed in the + * outgoing packet. + */ + sigdata_len = pktout.length - 5 + 4 + 20; + sigdata = smalloc(sigdata_len); + PUT_32BIT(sigdata, 20); + memcpy(sigdata+4, ssh2_session_id, 20); + memcpy(sigdata+24, pktout.data+5, pktout.length-5); + blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(blob, blob_len); + sfree(blob); + sfree(sigdata); + + ssh2_pkt_send(); + type = AUTH_TYPE_PUBLICKEY; + } + } else if (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. + * + * 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 + * people who find out how long their password is! + */ + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("password"); + ssh2_pkt_addbool(FALSE); + ssh2_pkt_addstring(password); + ssh2_pkt_defer(); + /* + * 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 (cscipher) { + int stringlen, i; + + stringlen = (256 - deferred_len); + stringlen += cscipher->blksize - 1; + stringlen -= (stringlen % cscipher->blksize); + if (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 -= cscomp->disable_compression(); + } + ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(); + for (i = 0; i < stringlen; i++) { + char c = (char)random_byte(); + ssh2_pkt_addstring_data(&c, 1); + } + ssh2_pkt_defer(); + } + ssh_pkt_defersend(); + logevent("Sent password"); + type = AUTH_TYPE_PASSWORD; + } else { + c_write_str("No supported authentication methods left to try!\r\n"); + logevent("No supported authentications offered. Disconnecting"); + ssh2_pkt_init(SSH2_MSG_DISCONNECT); + ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); + ssh2_pkt_addstring("No supported authentication methods available"); + ssh2_pkt_addstring("en"); /* language tag */ + ssh2_pkt_send(); + ssh_state = SSH_STATE_CLOSED; + crReturnV; + } + } + } while (!we_are_in); - crBegin; + /* + * 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. + */ /* - * Construct and send our key exchange packet. + * So now create a channel with a session in it. */ - ssh2_pkt_init(SSH2_MSG_KEXINIT); - for (i = 0; i < 16; i++) - ssh2_pkt_addbyte((unsigned char)random_byte()); - /* List key exchange algorithms. */ - ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(kex_algs); i++) { - ssh2_pkt_addstring_str(kex_algs[i]->name); - if (i < lenof(kex_algs)-1) - ssh2_pkt_addstring_str(","); - } - /* List server host key algorithms. */ - ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(hostkey_algs); i++) { - ssh2_pkt_addstring_str(hostkey_algs[i]->name); - if (i < lenof(hostkey_algs)-1) - ssh2_pkt_addstring_str(","); - } - /* List client->server encryption algorithms. */ - ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(ciphers); i++) { - ssh2_pkt_addstring_str(ciphers[i]->name); - if (i < lenof(ciphers)-1) - ssh2_pkt_addstring_str(","); - } - /* List server->client encryption algorithms. */ - ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(ciphers); i++) { - ssh2_pkt_addstring_str(ciphers[i]->name); - if (i < lenof(ciphers)-1) - ssh2_pkt_addstring_str(","); - } - /* List client->server MAC algorithms. */ - ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(macs); i++) { - ssh2_pkt_addstring_str(macs[i]->name); - if (i < lenof(macs)-1) - ssh2_pkt_addstring_str(","); - } - /* List server->client MAC algorithms. */ - ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(macs); i++) { - ssh2_pkt_addstring_str(macs[i]->name); - if (i < lenof(macs)-1) - ssh2_pkt_addstring_str(","); - } - /* List client->server compression algorithms. */ - ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(compressions); i++) { - ssh2_pkt_addstring_str(compressions[i]->name); - if (i < lenof(compressions)-1) - ssh2_pkt_addstring_str(","); + mainchan = smalloc(sizeof(struct ssh_channel)); + mainchan->localid = 100; /* as good as any */ + ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); + ssh2_pkt_addstring("session"); + ssh2_pkt_adduint32(mainchan->localid); + ssh2_pkt_adduint32(0x8000UL); /* our window size */ + ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ + ssh2_pkt_send(); + crWaitUntilV(ispkt); + if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { + bombout(("Server refused to open a session")); + crReturnV; + /* FIXME: error data comes back in FAILURE packet */ } - /* List server->client compression algorithms. */ - ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(compressions); i++) { - ssh2_pkt_addstring_str(compressions[i]->name); - if (i < lenof(compressions)-1) - ssh2_pkt_addstring_str(","); + if (ssh2_pkt_getuint32() != mainchan->localid) { + bombout(("Server's channel confirmation cited wrong channel")); + crReturnV; } - /* List client->server languages. Empty list. */ - ssh2_pkt_addstring_start(); - /* List server->client languages. Empty list. */ - ssh2_pkt_addstring_start(); - /* First KEX packet does _not_ follow, because we're not that brave. */ - ssh2_pkt_addbool(FALSE); - /* Reserved. */ - ssh2_pkt_adduint32(0); - sha_string(&exhash, pktout.data+5, pktout.length-5); - ssh2_pkt_send(); - - if (!ispkt) crWaitUntil(ispkt); - sha_string(&exhash, pktin.data+5, pktin.length-5); + mainchan->remoteid = ssh2_pkt_getuint32(); + mainchan->type = CHAN_MAINSESSION; + mainchan->closes = 0; + mainchan->v2.remwindow = ssh2_pkt_getuint32(); + mainchan->v2.remmaxpkt = ssh2_pkt_getuint32(); + mainchan->v2.outbuffer = NULL; + mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0; + ssh_channels = newtree234(ssh_channelcmp); + add234(ssh_channels, mainchan); + logevent("Opened channel for session"); /* - * Now examine the other side's KEXINIT to see what we're up - * to. + * Potentially enable X11 forwarding. */ - if (pktin.type != SSH2_MSG_KEXINIT) - fatalbox("expected key exchange packet from server"); - kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL; - csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL; - pktin.savedpos += 16; /* skip garbage cookie */ - ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ - for (i = 0; i < lenof(kex_algs); i++) { - if (in_commasep_string(kex_algs[i]->name, str, len)) { - kex = kex_algs[i]; - break; - } - } - ssh2_pkt_getstring(&str, &len); /* host key algorithms */ - for (i = 0; i < lenof(hostkey_algs); i++) { - if (in_commasep_string(hostkey_algs[i]->name, str, len)) { - hostkey = hostkey_algs[i]; - break; - } - } - ssh2_pkt_getstring(&str, &len); /* client->server cipher */ - for (i = 0; i < lenof(ciphers); i++) { - if (in_commasep_string(ciphers[i]->name, str, len)) { - cscipher_tobe = ciphers[i]; - break; - } - } - ssh2_pkt_getstring(&str, &len); /* server->client cipher */ - for (i = 0; i < lenof(ciphers); i++) { - if (in_commasep_string(ciphers[i]->name, str, len)) { - sccipher_tobe = ciphers[i]; - break; - } - } - ssh2_pkt_getstring(&str, &len); /* client->server mac */ - for (i = 0; i < lenof(macs); i++) { - if (in_commasep_string(macs[i]->name, str, len)) { - csmac_tobe = macs[i]; - break; - } - } - ssh2_pkt_getstring(&str, &len); /* server->client mac */ - for (i = 0; i < lenof(macs); i++) { - if (in_commasep_string(macs[i]->name, str, len)) { - scmac_tobe = macs[i]; - break; - } - } - ssh2_pkt_getstring(&str, &len); /* client->server compression */ - for (i = 0; i < lenof(compressions); i++) { - if (in_commasep_string(compressions[i]->name, str, len)) { - cscomp_tobe = compressions[i]; - break; - } - } - ssh2_pkt_getstring(&str, &len); /* server->client compression */ - for (i = 0; i < lenof(compressions); i++) { - if (in_commasep_string(compressions[i]->name, str, len)) { - sccomp_tobe = compressions[i]; - break; + if (cfg.x11_forward) { + char proto[20], data[64]; + logevent("Requesting X11 forwarding"); + x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); + ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); + ssh2_pkt_adduint32(mainchan->remoteid); + ssh2_pkt_addstring("x11-req"); + ssh2_pkt_addbool(1); /* want reply */ + ssh2_pkt_addbool(0); /* many connections */ + ssh2_pkt_addstring(proto); + ssh2_pkt_addstring(data); + ssh2_pkt_adduint32(0); /* screen number */ + ssh2_pkt_send(); + + do { + crWaitUntilV(ispkt); + if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { + unsigned i = ssh2_pkt_getuint32(); + struct ssh_channel *c; + c = find234(ssh_channels, &i, ssh_channelfind); + if (!c) + continue; /* nonexistent channel */ + c->v2.remwindow += ssh2_pkt_getuint32(); + } + } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); + + if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Server got confused by X11 forwarding request")); + crReturnV; + } + logevent("X11 forwarding refused"); + } else { + logevent("X11 forwarding enabled"); + ssh_X11_fwd_enabled = TRUE; } } - debug(("key exchange is %s\r\n", kex ? kex->name : NULL)); - debug(("host key alg is %s\r\n", hostkey ? hostkey->name : NULL)); - debug(("cscipher alg is %s\r\n", cscipher_tobe ? cscipher_tobe->name : NULL)); - debug(("sccipher alg is %s\r\n", sccipher_tobe ? sccipher_tobe->name : NULL)); - debug(("csmac alg is %s\r\n", csmac_tobe ? csmac_tobe->name : NULL)); - debug(("scmac alg is %s\r\n", scmac_tobe ? scmac_tobe->name : NULL)); - debug(("cscomp alg is %s\r\n", cscomp_tobe ? cscomp_tobe->name : NULL)); - debug(("sccomp alg is %s\r\n", sccomp_tobe ? sccomp_tobe->name : NULL)); /* - * Currently we only support Diffie-Hellman and DSS, so let's - * bomb out if those aren't selected. + * Potentially enable agent forwarding. */ - if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) - fatalbox("internal fault: chaos in SSH 2 transport layer"); + if (cfg.agentfwd && agent_exists()) { + char proto[20], data[64]; + logevent("Requesting OpenSSH-style agent forwarding"); + x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); + ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); + ssh2_pkt_adduint32(mainchan->remoteid); + ssh2_pkt_addstring("auth-agent-req@openssh.com"); + ssh2_pkt_addbool(1); /* want reply */ + ssh2_pkt_send(); + + do { + crWaitUntilV(ispkt); + if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { + unsigned i = ssh2_pkt_getuint32(); + struct ssh_channel *c; + c = find234(ssh_channels, &i, ssh_channelfind); + if (!c) + continue; /* nonexistent channel */ + c->v2.remwindow += ssh2_pkt_getuint32(); + } + } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); + + if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Server got confused by agent forwarding request")); + crReturnV; + } + logevent("Agent forwarding refused"); + } else { + logevent("Agent forwarding enabled"); + ssh_agentfwd_enabled = TRUE; + } + } /* - * Now we begin the fun. Generate and send e for Diffie-Hellman. + * Now allocate a pty for the session. */ - e = dh_create_e(); - bndebug("e=", e); - ssh2_pkt_init(SSH2_MSG_KEXDH_INIT); - ssh2_pkt_addmp(e); - ssh2_pkt_send(); - - crWaitUntil(ispkt); - if (pktin.type != SSH2_MSG_KEXDH_REPLY) - fatalbox("expected key exchange packet from server"); - ssh2_pkt_getstring(&hostkeydata, &hostkeylen); - f = ssh2_pkt_getmp(); - bndebug("f=", f); - ssh2_pkt_getstring(&sigdata, &siglen); - - K = dh_find_K(f); - bndebug("K=", K); + if (!cfg.nopty) { + ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); + ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ + ssh2_pkt_addstring("pty-req"); + ssh2_pkt_addbool(1); /* want reply */ + ssh2_pkt_addstring(cfg.termtype); + ssh2_pkt_adduint32(cols); + ssh2_pkt_adduint32(rows); + ssh2_pkt_adduint32(0); /* pixel width */ + ssh2_pkt_adduint32(0); /* pixel height */ + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */ + ssh2_pkt_send(); + ssh_state = SSH_STATE_INTERMED; - sha_string(&exhash, hostkeydata, hostkeylen); - sha_mpint(&exhash, e); - sha_mpint(&exhash, f); - sha_mpint(&exhash, K); - SHA_Final(&exhash, exchange_hash); + do { + crWaitUntilV(ispkt); + if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { + unsigned i = ssh2_pkt_getuint32(); + struct ssh_channel *c; + c = find234(ssh_channels, &i, ssh_channelfind); + if (!c) + continue; /* nonexistent channel */ + c->v2.remwindow += ssh2_pkt_getuint32(); + } + } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); - debug(("Exchange hash is:\r\n")); - for (i = 0; i < 20; i++) - debug((" %02x", exchange_hash[i])); - debug(("\r\n")); + if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Server got confused by pty request")); + crReturnV; + } + c_write_str("Server refused to allocate pty\r\n"); + ssh_editing = ssh_echoing = 1; + } else { + logevent("Allocated pty"); + } + } else { + ssh_editing = ssh_echoing = 1; + } /* - * FIXME: verify hostkeydata and sigdata. + * Start a shell or a remote command. */ - - crWaitUntil(0); - - crFinish(1); -} - -static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) { - crBegin; + ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); + ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ + if (cfg.ssh_subsys) { + ssh2_pkt_addstring("subsystem"); + ssh2_pkt_addbool(1); /* want reply */ + ssh2_pkt_addstring(cfg.remote_cmd); + } else if (*cfg.remote_cmd) { + ssh2_pkt_addstring("exec"); + ssh2_pkt_addbool(1); /* want reply */ + ssh2_pkt_addstring(cfg.remote_cmd); + } else { + ssh2_pkt_addstring("shell"); + ssh2_pkt_addbool(1); /* want reply */ + } + ssh2_pkt_send(); + do { + crWaitUntilV(ispkt); + if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { + unsigned i = ssh2_pkt_getuint32(); + struct ssh_channel *c; + c = find234(ssh_channels, &i, ssh_channelfind); + if (!c) + continue; /* nonexistent channel */ + c->v2.remwindow += ssh2_pkt_getuint32(); + } + } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); + if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Server got confused by shell/command request")); + crReturnV; + } + bombout(("Server refused to start a shell/command")); + crReturnV; + } else { + logevent("Started a shell/command"); + } - random_init(); + ssh_state = SSH_STATE_SESSION; + if (size_needed) + ssh_size(); + if (eof_needed) + ssh_special(TS_EOF); - while (!do_ssh2_kex(in, inlen, ispkt)) { + /* + * Transfer data! + */ + ldisc_send(NULL, 0); /* cause ldisc to notice changes */ + ssh_send_ok = 1; + while (1) { + static int try_send; crReturnV; + try_send = FALSE; + if (ispkt) { + if (pktin.type == SSH2_MSG_CHANNEL_DATA || + pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { + char *data; + int length; + unsigned i = ssh2_pkt_getuint32(); + struct ssh_channel *c; + c = find234(ssh_channels, &i, ssh_channelfind); + if (!c) + continue; /* nonexistent channel */ + if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && + ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) + continue; /* extended but not stderr */ + ssh2_pkt_getstring(&data, &length); + if (data) { + switch (c->type) { + case CHAN_MAINSESSION: + from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA, + data, length); + break; + case CHAN_X11: + x11_send(c->u.x11.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 = smalloc(c->u.a.totallen); + 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, *sentreply; + int replylen; + agent_query(c->u.a.message, c->u.a.totallen, + &reply, &replylen); + if (reply) + sentreply = reply; + else { + /* Fake SSH_AGENT_FAILURE. */ + sentreply = "\0\0\0\1\5"; + replylen = 5; + } + ssh2_add_channel_data(c, sentreply, replylen); + try_send = TRUE; + if (reply) + sfree(reply); + sfree(c->u.a.message); + c->u.a.lensofar = 0; + } + } + break; + } + /* + * Enlarge the window again at the remote + * side, just in case it ever runs down and + * they fail to send us any more data. + */ + ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_adduint32(length); + ssh2_pkt_send(); + } + } else if (pktin.type == SSH2_MSG_DISCONNECT) { + ssh_state = SSH_STATE_CLOSED; + logevent("Received disconnect message"); + crReturnV; + } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { + continue; /* exit status et al; ignore (FIXME?) */ + } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { + unsigned i = ssh2_pkt_getuint32(); + 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 (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { + unsigned i = ssh2_pkt_getuint32(); + struct ssh_channel *c; + enum234 e; + + c = find234(ssh_channels, &i, ssh_channelfind); + if (!c) + continue; /* nonexistent channel */ + if (c->closes == 0) { + ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_send(); + } + /* Do pre-close processing on the channel. */ + switch (c->type) { + case CHAN_MAINSESSION: + break; /* nothing to see here, move along */ + case CHAN_X11: + break; + case CHAN_AGENT: + break; + } + del234(ssh_channels, c); + sfree(c->v2.outbuffer); + sfree(c); + + /* + * See if that was the last channel left open. + */ + c = first234(ssh_channels, &e); + if (!c) { + logevent("All channels closed. Disconnecting"); + ssh2_pkt_init(SSH2_MSG_DISCONNECT); + ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); + ssh2_pkt_addstring("All open channels closed"); + ssh2_pkt_addstring("en"); /* language tag */ + ssh2_pkt_send(); + ssh_state = SSH_STATE_CLOSED; + crReturnV; + } + continue; /* remote sends close; ignore (FIXME) */ + } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { + unsigned i = ssh2_pkt_getuint32(); + struct ssh_channel *c; + c = find234(ssh_channels, &i, ssh_channelfind); + if (!c) + continue; /* nonexistent channel */ + mainchan->v2.remwindow += ssh2_pkt_getuint32(); + try_send = TRUE; + } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { + char *type; + int typelen; + char *error = NULL; + struct ssh_channel *c; + ssh2_pkt_getstring(&type, &typelen); + c = smalloc(sizeof(struct ssh_channel)); + + if (typelen == 3 && !memcmp(type, "x11", 3)) { + if (!ssh_X11_fwd_enabled) + error = "X11 forwarding is not enabled"; + else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) { + error = "Unable to open an X11 connection"; + } else { + c->type = CHAN_X11; + } + } 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"; + } + + c->remoteid = ssh2_pkt_getuint32(); + if (error) { + ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED); + ssh2_pkt_addstring(error); + ssh2_pkt_addstring("en"); /* language tag */ + ssh2_pkt_send(); + sfree(c); + } else { + struct ssh_channel *d; + unsigned i; + enum234 e; + + for (i=1, d = first234(ssh_channels, &e); d; + d = next234(&e)) { + if (d->localid > i) + break; /* found a free number */ + i = d->localid + 1; + } + c->localid = i; + c->closes = 0; + c->v2.remwindow = ssh2_pkt_getuint32(); + c->v2.remmaxpkt = ssh2_pkt_getuint32(); + c->v2.outbuffer = NULL; + c->v2.outbuflen = c->v2.outbufsize = 0; + add234(ssh_channels, c); + ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_adduint32(c->localid); + ssh2_pkt_adduint32(0x8000UL); /* our window size */ + ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ + ssh2_pkt_send(); + } + } else { + bombout(("Strange packet received: type %d", pktin.type)); + crReturnV; + } + } else { + /* + * We have spare data. Add it to the channel buffer. + */ + ssh2_add_channel_data(mainchan, in, inlen); + try_send = TRUE; + } + if (try_send) { + enum234 e; + struct ssh_channel *c; + /* + * Try to send data on all channels if we can. + */ + for (c = first234(ssh_channels, &e); c; c = next234(&e)) + ssh2_try_send(c); + } } crFinishV; } /* - * Called to set up the connection. Will arrange for WM_NETEVENT - * messages to be passed to the specified window, whose window - * procedure should then call telnet_msg(). + * Handle the top-level SSH2 protocol. + */ +static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) +{ + if (do_ssh2_transport(in, inlen, ispkt) == 0) + return; + do_ssh2_authconn(in, inlen, ispkt); +} + +/* + * Called to set up the connection. * * Returns an error message, or NULL on success. */ -static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) { +static char *ssh_init (char *host, int port, char **realhost) { char *p; #ifdef MSCRYPTOAPI @@ -1554,82 +3844,34 @@ static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) { return "Microsoft high encryption pack not installed!"; #endif + ssh_send_ok = 0; + ssh_editing = 0; + ssh_echoing = 0; + p = connect_to_host(host, port, realhost); if (p != NULL) return p; - if (!do_ssh_init()) - return "Protocol initialisation error"; - - if (WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR) - switch (WSAGetLastError()) { - case WSAENETDOWN: return "Network is down"; - default: return "WSAAsyncSelect(): unknown error"; - } - return NULL; } /* - * Process a WM_NETEVENT message. Will return 0 if the connection - * has closed, or <0 for a socket error. - */ -static int ssh_msg (WPARAM wParam, LPARAM lParam) { - int ret; - char buf[256]; - - /* - * Because reading less than the whole of the available pending - * data can generate an FD_READ event, we need to allow for the - * possibility that FD_READ may arrive with FD_CLOSE already in - * the queue; so it's possible that we can get here even with s - * invalid. If so, we return 1 and don't worry about it. - */ - if (s == INVALID_SOCKET) - return 1; - - if (WSAGETSELECTERROR(lParam) != 0) - return -WSAGETSELECTERROR(lParam); - - switch (WSAGETSELECTEVENT(lParam)) { - case FD_READ: - case FD_CLOSE: - ret = recv(s, buf, sizeof(buf), 0); - if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK) - return 1; - if (ret < 0) /* any _other_ error */ - return -10000-WSAGetLastError(); - if (ret == 0) { - s = INVALID_SOCKET; - return 0; - } - ssh_gotdata (buf, ret); - if (ssh_state == SSH_STATE_CLOSED) { - closesocket(s); - s = INVALID_SOCKET; - return 0; - } - return 1; - } - return 1; /* shouldn't happen, but WTF */ -} - -/* * Called to send data down the Telnet connection. */ static void ssh_send (char *buf, int len) { - if (s == INVALID_SOCKET) + if (s == NULL || ssh_protocol == NULL) return; ssh_protocol(buf, len, 0); } /* - * Called to set the size of the window from Telnet's POV. + * Called to set the size of the window from SSH's POV. */ static void ssh_size(void) { switch (ssh_state) { case SSH_STATE_BEFORE_SIZE: + case SSH_STATE_PREPACKET: case SSH_STATE_CLOSED: break; /* do nothing */ case SSH_STATE_INTERMED: @@ -1637,198 +3879,82 @@ static void ssh_size(void) { break; case SSH_STATE_SESSION: if (!cfg.nopty) { - send_packet(SSH1_CMSG_WINDOW_SIZE, - PKT_INT, rows, PKT_INT, cols, - PKT_INT, 0, PKT_INT, 0, PKT_END); + if (ssh_version == 1) { + send_packet(SSH1_CMSG_WINDOW_SIZE, + PKT_INT, rows, PKT_INT, cols, + PKT_INT, 0, PKT_INT, 0, PKT_END); + } else { + ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); + ssh2_pkt_adduint32(mainchan->remoteid); + ssh2_pkt_addstring("window-change"); + ssh2_pkt_addbool(0); + ssh2_pkt_adduint32(cols); + ssh2_pkt_adduint32(rows); + ssh2_pkt_adduint32(0); + ssh2_pkt_adduint32(0); + ssh2_pkt_send(); + } } + break; } } /* - * (Send Telnet special codes) + * Send Telnet special codes. TS_EOF is useful for `plink', so you + * can send an EOF and collect resulting output (e.g. `plink + * hostname sort'). */ static void ssh_special (Telnet_Special code) { - /* do nothing */ -} - - -/* - * Read and decrypt one incoming SSH packet. - * (only used by pSCP) - */ -static void get_packet(void) -{ - unsigned char buf[4096], *p; - long to_read; - int len; - - assert(IS_SCP); - - p = NULL; - len = 0; - - while ((to_read = s_rdpkt(&p, &len)) > 0) { - if (to_read > sizeof(buf)) to_read = sizeof(buf); - len = s_read(buf, to_read); - if (len != to_read) { - closesocket(s); - s = INVALID_SOCKET; - return; - } - p = buf; - } - - assert(len == 0); -} - -/* - * Receive a block of data over the SSH link. Block until - * all data is available. Return nr of bytes read (0 if lost connection). - * (only used by pSCP) - */ -int ssh_scp_recv(unsigned char *buf, int len) -{ - static int pending_input_len = 0; - static unsigned char *pending_input_ptr; - int to_read = len; - - assert(IS_SCP); - - if (pending_input_len >= to_read) { - memcpy(buf, pending_input_ptr, to_read); - pending_input_ptr += to_read; - pending_input_len -= to_read; - return len; - } - - if (pending_input_len > 0) { - memcpy(buf, pending_input_ptr, pending_input_len); - buf += pending_input_len; - to_read -= pending_input_len; - pending_input_len = 0; - } - - if (s == INVALID_SOCKET) - return 0; - while (to_read > 0) { - get_packet(); - if (s == INVALID_SOCKET) - return 0; - if (pktin.type == SSH1_SMSG_STDOUT_DATA) { - int plen = GET_32BIT(pktin.body); - if (plen <= to_read) { - memcpy(buf, pktin.body + 4, plen); - buf += plen; - to_read -= plen; - } else { - memcpy(buf, pktin.body + 4, to_read); - pending_input_len = plen - to_read; - pending_input_ptr = pktin.body + 4 + to_read; - to_read = 0; - } - } else if (pktin.type == SSH1_SMSG_STDERR_DATA) { - int plen = GET_32BIT(pktin.body); - fwrite(pktin.body + 4, plen, 1, stderr); - } else if (pktin.type == SSH1_MSG_DISCONNECT) { - logevent("Received disconnect request"); - } else if (pktin.type == SSH1_SMSG_SUCCESS || - pktin.type == SSH1_SMSG_FAILURE) { - /* ignore */ - } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { - char logbuf[100]; - sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body)); - logevent(logbuf); - send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); - logevent("Closing connection"); - closesocket(s); - s = INVALID_SOCKET; - } else { - fatalbox("Strange packet received: type %d", pktin.type); - } + if (code == TS_EOF) { + if (ssh_state != SSH_STATE_SESSION) { + /* + * Buffer the EOF in case we are pre-SESSION, so we can + * send it as soon as we reach SESSION. + */ + if (code == TS_EOF) + eof_needed = TRUE; + return; + } + if (ssh_version == 1) { + send_packet(SSH1_CMSG_EOF, PKT_END); + } else { + ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); + ssh2_pkt_adduint32(mainchan->remoteid); + ssh2_pkt_send(); + } + logevent("Sent EOF message"); + } else if (code == TS_PING) { + if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET) + return; + if (ssh_version == 1) { + send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); + } else { + ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(); + ssh2_pkt_send(); + } + } else { + /* do nothing */ } - - return len; -} - -/* - * Send a block of data over the SSH link. - * Block until all data is sent. - * (only used by pSCP) - */ -void ssh_scp_send(unsigned char *buf, int len) -{ - assert(IS_SCP); - if (s == INVALID_SOCKET) - return; - send_packet(SSH1_CMSG_STDIN_DATA, - PKT_INT, len, PKT_DATA, buf, len, PKT_END); -} - -/* - * Send an EOF notification to the server. - * (only used by pSCP) - */ -void ssh_scp_send_eof(void) -{ - assert(IS_SCP); - if (s == INVALID_SOCKET) - return; - send_packet(SSH1_CMSG_EOF, PKT_END); } -/* - * Set up the connection, login on the remote host and - * start execution of a command. - * Returns an error message, or NULL on success. - * (only used by pSCP) - */ -char *ssh_scp_init(char *host, int port, char *cmd, char **realhost) -{ - char buf[160], *p; - - assert(IS_SCP); - -#ifdef MSCRYPTOAPI - if (crypto_startup() == 0) - return "Microsoft high encryption pack not installed!"; -#endif - - p = connect_to_host(host, port, realhost); - if (p != NULL) - return p; - - random_init(); - - if (!do_ssh_init()) - return "Protocol initialisation error"; +static Socket ssh_socket(void) { return s; } - /* Exchange keys and login */ - do { - get_packet(); - if (s == INVALID_SOCKET) - return "Connection closed by remote host"; - } while (!do_ssh1_login(NULL, 0, 1)); - - if (ssh_state == SSH_STATE_CLOSED) { - closesocket(s); - s = INVALID_SOCKET; - return "Session initialisation error"; - } +static int ssh_sendok(void) { return ssh_send_ok; } - /* Execute command */ - sprintf(buf, "Sending command: %.100s", cmd); - logevent(buf); - send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); - - return NULL; +static int ssh_ldisc(int option) { + if (option == LD_ECHO) return ssh_echoing; + if (option == LD_EDIT) return ssh_editing; + return FALSE; } - Backend ssh_backend = { ssh_init, - ssh_msg, ssh_send, ssh_size, - ssh_special + ssh_special, + ssh_socket, + ssh_sendok, + ssh_ldisc, + 22 }; -