18 /* uncomment this for packet level debugging */
19 /* #define DUMP_PACKETS */
21 #define logevent(s) { logevent(s); \
22 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
23 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
25 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
26 (s ? sk_close(s), s = NULL : 0), \
27 connection_fatal msg )
29 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
30 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
31 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
32 #define SSH1_CMSG_USER 4 /* 0x4 */
33 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
34 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
35 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
36 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
37 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
38 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
39 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
40 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
41 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
42 #define SSH1_SMSG_FAILURE 15 /* 0xf */
43 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
44 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
45 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
46 #define SSH1_CMSG_EOF 19 /* 0x13 */
47 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
48 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
49 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
50 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
51 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
52 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
53 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
54 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
55 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
56 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
57 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
58 #define SSH1_MSG_IGNORE 32 /* 0x20 */
59 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
60 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
61 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
62 #define SSH1_MSG_DEBUG 36 /* 0x24 */
63 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
64 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
65 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
66 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
67 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
68 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
69 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
71 #define SSH1_AUTH_TIS 5 /* 0x5 */
72 #define SSH1_AUTH_CCARD 16 /* 0x10 */
74 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
75 /* Mask for protoflags we will echo back to server if seen */
76 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
78 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
79 #define SSH2_MSG_IGNORE 2 /* 0x2 */
80 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
81 #define SSH2_MSG_DEBUG 4 /* 0x4 */
82 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
83 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
84 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
85 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
86 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
87 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
88 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
89 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
90 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
91 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
92 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
93 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
94 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
95 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
96 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
97 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
98 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
99 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
100 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
101 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
102 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
103 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
104 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
105 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
106 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
107 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
108 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
109 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
110 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
111 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
113 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
114 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
115 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
116 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
117 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
118 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
119 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
120 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
121 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
122 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
123 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
124 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
125 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
126 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
127 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
129 static const char *const ssh2_disconnect_reasons[] = {
131 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
132 "SSH_DISCONNECT_PROTOCOL_ERROR",
133 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
134 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
135 "SSH_DISCONNECT_MAC_ERROR",
136 "SSH_DISCONNECT_COMPRESSION_ERROR",
137 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
138 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
139 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
140 "SSH_DISCONNECT_CONNECTION_LOST",
141 "SSH_DISCONNECT_BY_APPLICATION",
142 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
143 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
144 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
145 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
148 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
149 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
150 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
151 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
153 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
156 * Various remote-bug flags.
158 #define BUG_CHOKES_ON_SSH1_IGNORE 1
159 #define BUG_SSH2_HMAC 2
161 #define GET_32BIT(cp) \
162 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
163 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
164 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
165 ((unsigned long)(unsigned char)(cp)[3]))
167 #define PUT_32BIT(cp, value) { \
168 (cp)[0] = (unsigned char)((value) >> 24); \
169 (cp)[1] = (unsigned char)((value) >> 16); \
170 (cp)[2] = (unsigned char)((value) >> 8); \
171 (cp)[3] = (unsigned char)(value); }
173 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
175 /* Coroutine mechanics for the sillier bits of the code */
176 #define crBegin1 static int crLine = 0;
177 #define crBegin2 switch(crLine) { case 0:;
178 #define crBegin crBegin1; crBegin2;
179 #define crFinish(z) } crLine = 0; return (z)
180 #define crFinishV } crLine = 0; return
181 #define crReturn(z) \
183 crLine=__LINE__; return (z); case __LINE__:;\
187 crLine=__LINE__; return; case __LINE__:;\
189 #define crStop(z) do{ crLine = 0; return (z); }while(0)
190 #define crStopV do{ crLine = 0; return; }while(0)
191 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
192 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
194 extern char *x11_init(Socket *, char *, void *);
195 extern void x11_close(Socket);
196 extern void x11_send(Socket, char *, int);
197 extern void x11_invent_auth(char *, int, char *, int);
199 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
200 extern char *pfd_addforward(char *desthost, int destport, int port);
201 extern void pfd_close(Socket s);
202 extern void pfd_send(Socket s, char *data, int len);
203 extern void pfd_confirm(Socket s);
206 * Ciphers for SSH2. We miss out single-DES because it isn't
207 * supported; also 3DES and Blowfish are both done differently from
208 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
209 * endianness and different-sized keys.)
211 const static struct ssh2_ciphers *ciphers[] = {
217 const static struct ssh_kex *kex_algs[] = {
218 &ssh_diffiehellman_gex,
222 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
224 static void nullmac_key(unsigned char *key)
227 static void nullmac_generate(unsigned char *blk, int len,
231 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
235 const static struct ssh_mac ssh_mac_none = {
236 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
238 const static struct ssh_mac *macs[] = {
239 &ssh_sha1, &ssh_md5, &ssh_mac_none
241 const static struct ssh_mac *buggymacs[] = {
242 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
245 static void ssh_comp_none_init(void)
248 static int ssh_comp_none_block(unsigned char *block, int len,
249 unsigned char **outblock, int *outlen)
253 static int ssh_comp_none_disable(void)
257 const static struct ssh_compress ssh_comp_none = {
259 ssh_comp_none_init, ssh_comp_none_block,
260 ssh_comp_none_init, ssh_comp_none_block,
261 ssh_comp_none_disable
263 extern const struct ssh_compress ssh_zlib;
264 const static struct ssh_compress *compressions[] = {
265 &ssh_zlib, &ssh_comp_none
268 enum { /* channel types */
276 * 2-3-4 tree storing channels.
279 unsigned remoteid, localid;
282 struct ssh2_data_channel {
283 unsigned char *outbuffer;
284 unsigned outbuflen, outbufsize;
285 unsigned remwindow, remmaxpkt;
288 struct ssh_agent_channel {
289 unsigned char *message;
290 unsigned char msglen[4];
291 int lensofar, totallen;
293 struct ssh_x11_channel {
296 struct ssh_pfd_channel {
303 * 2-3-4 tree storing remote->local port forwardings (so we can
304 * reject any attempt to open a port we didn't explicitly ask to
307 struct ssh_rportfwd {
321 static SHA_State exhash, exhashbase;
323 static Socket s = NULL;
325 static unsigned char session_key[32];
326 static int ssh1_compressing;
327 static int ssh1_remote_protoflags;
328 static int ssh1_local_protoflags;
329 static int ssh_agentfwd_enabled;
330 static int ssh_X11_fwd_enabled;
331 static int ssh_remote_bugs;
332 static const struct ssh_cipher *cipher = NULL;
333 static const struct ssh2_cipher *cscipher = NULL;
334 static const struct ssh2_cipher *sccipher = NULL;
335 static const struct ssh_mac *csmac = NULL;
336 static const struct ssh_mac *scmac = NULL;
337 static const struct ssh_compress *cscomp = NULL;
338 static const struct ssh_compress *sccomp = NULL;
339 static const struct ssh_kex *kex = NULL;
340 static const struct ssh_signkey *hostkey = NULL;
341 static unsigned char ssh2_session_id[20];
342 int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
345 static char *savedhost;
346 static int savedport;
347 static int ssh_send_ok;
348 static int ssh_echoing, ssh_editing;
350 static tree234 *ssh_channels; /* indexed by local id */
351 static struct ssh_channel *mainchan; /* primary session channel */
353 static tree234 *ssh_rportfwds;
357 SSH_STATE_BEFORE_SIZE,
361 } ssh_state = SSH_STATE_PREPACKET;
363 static int size_needed = FALSE, eof_needed = FALSE;
365 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
366 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
367 static unsigned char *deferred_send_data = NULL;
368 static int deferred_len = 0, deferred_size = 0;
370 static int ssh_version;
371 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
372 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
373 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
374 static void ssh_size(void);
375 static void ssh_special(Telnet_Special);
376 static void ssh2_try_send(struct ssh_channel *c);
377 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
380 static int (*s_rdpkt) (unsigned char **data, int *datalen);
382 static struct rdpkt1_state_tag {
383 long len, pad, biglen, to_read;
384 unsigned long realcrc, gotcrc;
390 static struct rdpkt2_state_tag {
391 long len, pad, payload, packetlen, maclen;
394 unsigned long incoming_sequence;
397 static int ssh_channelcmp(void *av, void *bv)
399 struct ssh_channel *a = (struct ssh_channel *) av;
400 struct ssh_channel *b = (struct ssh_channel *) bv;
401 if (a->localid < b->localid)
403 if (a->localid > b->localid)
407 static int ssh_channelfind(void *av, void *bv)
409 unsigned *a = (unsigned *) av;
410 struct ssh_channel *b = (struct ssh_channel *) bv;
418 static int ssh_rportcmp(void *av, void *bv)
420 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
421 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
423 if ( (i = strcmp(a->host, b->host)) != 0)
424 return i < 0 ? -1 : +1;
425 if (a->port > b->port)
430 static int alloc_channel_id(void)
432 const unsigned CHANNEL_NUMBER_OFFSET = 256;
433 unsigned low, high, mid;
435 struct ssh_channel *c;
438 * First-fit allocation of channel numbers: always pick the
439 * lowest unused one. To do this, binary-search using the
440 * counted B-tree to find the largest channel ID which is in a
441 * contiguous sequence from the beginning. (Precisely
442 * everything in that sequence must have ID equal to its tree
443 * index plus CHANNEL_NUMBER_OFFSET.)
445 tsize = count234(ssh_channels);
449 while (high - low > 1) {
450 mid = (high + low) / 2;
451 c = index234(ssh_channels, mid);
452 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
453 low = mid; /* this one is fine */
455 high = mid; /* this one is past it */
458 * Now low points to either -1, or the tree index of the
459 * largest ID in the initial sequence.
462 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
463 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
465 return low + 1 + CHANNEL_NUMBER_OFFSET;
468 static void c_write(char *buf, int len)
470 if ((flags & FLAG_STDERR)) {
472 for (i = 0; i < len; i++)
474 fputc(buf[i], stderr);
477 from_backend(1, buf, len);
480 static void c_write_untrusted(char *buf, int len)
483 for (i = 0; i < len; i++) {
486 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
491 static void c_write_str(char *buf)
493 c_write(buf, strlen(buf));
497 * Collect incoming data in the incoming packet buffer.
498 * Decipher and verify the packet when it is completely read.
499 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
500 * Update the *data and *datalen variables.
501 * Return the additional nr of bytes needed, or 0 when
502 * a complete packet is available.
504 static int ssh1_rdpkt(unsigned char **data, int *datalen)
506 struct rdpkt1_state_tag *st = &rdpkt1_state;
515 for (st->i = st->len = 0; st->i < 4; st->i++) {
516 while ((*datalen) == 0)
518 st->len = (st->len << 8) + **data;
519 (*data)++, (*datalen)--;
523 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
524 st->len = 0x300; /* big enough to carry to end */
528 st->pad = 8 - (st->len % 8);
529 st->biglen = st->len + st->pad;
530 pktin.length = st->len - 5;
532 if (pktin.maxlen < st->biglen) {
533 pktin.maxlen = st->biglen;
534 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
535 srealloc(pktin.data, st->biglen + APIEXTRA));
537 fatalbox("Out of memory");
540 st->to_read = st->biglen;
542 while (st->to_read > 0) {
543 st->chunk = st->to_read;
544 while ((*datalen) == 0)
545 crReturn(st->to_read);
546 if (st->chunk > (*datalen))
547 st->chunk = (*datalen);
548 memcpy(st->p, *data, st->chunk);
550 *datalen -= st->chunk;
552 st->to_read -= st->chunk;
556 cipher->decrypt(pktin.data, st->biglen);
558 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
559 dmemdump(pktin.data, st->biglen);
562 st->realcrc = crc32(pktin.data, st->biglen - 4);
563 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
564 if (st->gotcrc != st->realcrc) {
565 bombout(("Incorrect CRC received on packet"));
569 pktin.body = pktin.data + st->pad + 1;
571 if (ssh1_compressing) {
572 unsigned char *decompblk;
575 debug(("Packet payload pre-decompression:\n"));
576 dmemdump(pktin.body - 1, pktin.length + 1);
578 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
579 &decompblk, &decomplen);
581 if (pktin.maxlen < st->pad + decomplen) {
582 pktin.maxlen = st->pad + decomplen;
583 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
584 pktin.body = pktin.data + st->pad + 1;
586 fatalbox("Out of memory");
589 memcpy(pktin.body - 1, decompblk, decomplen);
591 pktin.length = decomplen - 1;
593 debug(("Packet payload post-decompression:\n"));
594 dmemdump(pktin.body - 1, pktin.length + 1);
598 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
599 pktin.type == SSH1_SMSG_STDERR_DATA ||
600 pktin.type == SSH1_MSG_DEBUG ||
601 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
602 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
603 long strlen = GET_32BIT(pktin.body);
604 if (strlen + 4 != pktin.length) {
605 bombout(("Received data packet with bogus string length"));
610 pktin.type = pktin.body[-1];
612 if (pktin.type == SSH1_MSG_DEBUG) {
613 /* log debug message */
615 int strlen = GET_32BIT(pktin.body);
616 strcpy(buf, "Remote: ");
619 memcpy(buf + 8, pktin.body + 4, strlen);
620 buf[8 + strlen] = '\0';
623 } else if (pktin.type == SSH1_MSG_IGNORE) {
628 if (pktin.type == SSH1_MSG_DISCONNECT) {
629 /* log reason code in disconnect message */
631 unsigned msglen = GET_32BIT(pktin.body);
633 strcpy(buf, "Remote sent disconnect: ");
634 nowlen = strlen(buf);
635 if (msglen > sizeof(buf) - nowlen - 1)
636 msglen = sizeof(buf) - nowlen - 1;
637 memcpy(buf + nowlen, pktin.body + 4, msglen);
638 buf[nowlen + msglen] = '\0';
645 static int ssh2_rdpkt(unsigned char **data, int *datalen)
647 struct rdpkt2_state_tag *st = &rdpkt2_state;
655 st->cipherblk = sccipher->blksize;
658 if (st->cipherblk < 8)
661 if (pktin.maxlen < st->cipherblk) {
662 pktin.maxlen = st->cipherblk;
665 NULL ? smalloc(st->cipherblk +
666 APIEXTRA) : srealloc(pktin.data,
670 fatalbox("Out of memory");
674 * Acquire and decrypt the first block of the packet. This will
675 * contain the length and padding details.
677 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
678 while ((*datalen) == 0)
679 crReturn(st->cipherblk - st->i);
680 pktin.data[st->i] = *(*data)++;
684 if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */
689 sccipher->decrypt(pktin.data, st->cipherblk);
692 * Now get the length and padding figures.
694 st->len = GET_32BIT(pktin.data);
695 st->pad = pktin.data[4];
698 * This enables us to deduce the payload length.
700 st->payload = st->len - st->pad - 1;
702 pktin.length = st->payload + 5;
705 * So now we can work out the total packet length.
707 st->packetlen = st->len + 4;
708 st->maclen = scmac ? scmac->len : 0;
711 * Adjust memory allocation if packet is too big.
713 if (pktin.maxlen < st->packetlen + st->maclen) {
714 pktin.maxlen = st->packetlen + st->maclen;
717 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
722 fatalbox("Out of memory");
726 * Read and decrypt the remainder of the packet.
728 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
730 while ((*datalen) == 0)
731 crReturn(st->packetlen + st->maclen - st->i);
732 pktin.data[st->i] = *(*data)++;
735 /* Decrypt everything _except_ the MAC. */
737 sccipher->decrypt(pktin.data + st->cipherblk,
738 st->packetlen - st->cipherblk);
741 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
742 dmemdump(pktin.data, st->packetlen);
749 && !scmac->verify(pktin.data, st->len + 4,
750 st->incoming_sequence)) {
751 bombout(("Incorrect MAC received on packet"));
754 st->incoming_sequence++; /* whether or not we MACed */
757 * Decompress packet payload.
760 unsigned char *newpayload;
762 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
763 &newpayload, &newlen)) {
764 if (pktin.maxlen < newlen + 5) {
765 pktin.maxlen = newlen + 5;
768 NULL ? smalloc(pktin.maxlen +
769 APIEXTRA) : srealloc(pktin.data,
773 fatalbox("Out of memory");
775 pktin.length = 5 + newlen;
776 memcpy(pktin.data + 5, newpayload, newlen);
778 debug(("Post-decompression payload:\n"));
779 dmemdump(pktin.data + 5, newlen);
787 pktin.type = pktin.data[5];
789 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
790 goto next_packet; /* FIXME: print DEBUG message */
792 if (pktin.type == SSH2_MSG_DISCONNECT) {
793 /* log reason code in disconnect message */
795 int reason = GET_32BIT(pktin.data + 6);
796 unsigned msglen = GET_32BIT(pktin.data + 10);
798 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
799 sprintf(buf, "Received disconnect message (%s)",
800 ssh2_disconnect_reasons[reason]);
802 sprintf(buf, "Received disconnect message (unknown type %d)",
806 strcpy(buf, "Disconnection message text: ");
807 nowlen = strlen(buf);
808 if (msglen > sizeof(buf) - nowlen - 1)
809 msglen = sizeof(buf) - nowlen - 1;
810 memcpy(buf + nowlen, pktin.data + 14, msglen);
811 buf[nowlen + msglen] = '\0';
818 static void ssh1_pktout_size(int len)
822 len += 5; /* type and CRC */
826 pktout.length = len - 5;
827 if (pktout.maxlen < biglen) {
828 pktout.maxlen = biglen;
830 /* Allocate enough buffer space for extra block
831 * for MS CryptEncrypt() */
832 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
833 srealloc(pktout.data, biglen + 12));
835 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
836 srealloc(pktout.data, biglen + 4));
839 fatalbox("Out of memory");
841 pktout.body = pktout.data + 4 + pad + 1;
844 static void s_wrpkt_start(int type, int len)
846 ssh1_pktout_size(len);
850 static int s_wrpkt_prepare(void)
852 int pad, len, biglen, i;
855 pktout.body[-1] = pktout.type;
858 debug(("Packet payload pre-compression:\n"));
859 dmemdump(pktout.body - 1, pktout.length + 1);
862 if (ssh1_compressing) {
863 unsigned char *compblk;
865 zlib_compress_block(pktout.body - 1, pktout.length + 1,
867 ssh1_pktout_size(complen - 1);
868 memcpy(pktout.body - 1, compblk, complen);
871 debug(("Packet payload post-compression:\n"));
872 dmemdump(pktout.body - 1, pktout.length + 1);
876 len = pktout.length + 5; /* type and CRC */
880 for (i = 0; i < pad; i++)
881 pktout.data[i + 4] = random_byte();
882 crc = crc32(pktout.data + 4, biglen - 4);
883 PUT_32BIT(pktout.data + biglen, crc);
884 PUT_32BIT(pktout.data, len);
887 debug(("Sending packet len=%d\n", biglen + 4));
888 dmemdump(pktout.data, biglen + 4);
891 cipher->encrypt(pktout.data + 4, biglen);
896 static void s_wrpkt(void)
899 len = s_wrpkt_prepare();
900 sk_write(s, pktout.data, len);
903 static void s_wrpkt_defer(void)
906 len = s_wrpkt_prepare();
907 if (deferred_len + len > deferred_size) {
908 deferred_size = deferred_len + len + 128;
909 deferred_send_data = srealloc(deferred_send_data, deferred_size);
911 memcpy(deferred_send_data + deferred_len, pktout.data, len);
916 * Construct a packet with the specified contents.
918 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
920 unsigned char *p, *argp, argchar;
921 unsigned long argint;
922 int pktlen, argtype, arglen;
926 while ((argtype = va_arg(ap1, int)) != PKT_END) {
929 (void) va_arg(ap1, int);
933 (void) va_arg(ap1, char);
937 (void) va_arg(ap1, unsigned char *);
938 arglen = va_arg(ap1, int);
942 argp = va_arg(ap1, unsigned char *);
943 arglen = strlen(argp);
944 pktlen += 4 + arglen;
947 bn = va_arg(ap1, Bignum);
948 pktlen += ssh1_bignum_length(bn);
955 s_wrpkt_start(pkttype, pktlen);
958 while ((argtype = va_arg(ap2, int)) != PKT_END) {
961 argint = va_arg(ap2, int);
962 PUT_32BIT(p, argint);
966 argchar = va_arg(ap2, unsigned char);
971 argp = va_arg(ap2, unsigned char *);
972 arglen = va_arg(ap2, int);
973 memcpy(p, argp, arglen);
977 argp = va_arg(ap2, unsigned char *);
978 arglen = strlen(argp);
979 PUT_32BIT(p, arglen);
980 memcpy(p + 4, argp, arglen);
984 bn = va_arg(ap2, Bignum);
985 p += ssh1_write_bignum(p, bn);
991 static void send_packet(int pkttype, ...)
994 va_start(ap1, pkttype);
995 va_start(ap2, pkttype);
996 construct_packet(pkttype, ap1, ap2);
1000 static void defer_packet(int pkttype, ...)
1003 va_start(ap1, pkttype);
1004 va_start(ap2, pkttype);
1005 construct_packet(pkttype, ap1, ap2);
1009 static int ssh_versioncmp(char *a, char *b)
1012 unsigned long av, bv;
1014 av = strtoul(a, &ae, 10);
1015 bv = strtoul(b, &be, 10);
1017 return (av < bv ? -1 : +1);
1022 av = strtoul(ae, &ae, 10);
1023 bv = strtoul(be, &be, 10);
1025 return (av < bv ? -1 : +1);
1031 * Utility routines for putting an SSH-protocol `string' and
1032 * `uint32' into a SHA state.
1035 static void sha_string(SHA_State * s, void *str, int len)
1037 unsigned char lenblk[4];
1038 PUT_32BIT(lenblk, len);
1039 SHA_Bytes(s, lenblk, 4);
1040 SHA_Bytes(s, str, len);
1043 static void sha_uint32(SHA_State * s, unsigned i)
1045 unsigned char intblk[4];
1046 PUT_32BIT(intblk, i);
1047 SHA_Bytes(s, intblk, 4);
1051 * SSH2 packet construction functions.
1053 static void ssh2_pkt_ensure(int length)
1055 if (pktout.maxlen < length) {
1056 pktout.maxlen = length + 256;
1059 NULL ? smalloc(pktout.maxlen +
1060 APIEXTRA) : srealloc(pktout.data,
1064 fatalbox("Out of memory");
1067 static void ssh2_pkt_adddata(void *data, int len)
1069 pktout.length += len;
1070 ssh2_pkt_ensure(pktout.length);
1071 memcpy(pktout.data + pktout.length - len, data, len);
1073 static void ssh2_pkt_addbyte(unsigned char byte)
1075 ssh2_pkt_adddata(&byte, 1);
1077 static void ssh2_pkt_init(int pkt_type)
1080 ssh2_pkt_addbyte((unsigned char) pkt_type);
1082 static void ssh2_pkt_addbool(unsigned char value)
1084 ssh2_pkt_adddata(&value, 1);
1086 static void ssh2_pkt_adduint32(unsigned long value)
1089 PUT_32BIT(x, value);
1090 ssh2_pkt_adddata(x, 4);
1092 static void ssh2_pkt_addstring_start(void)
1094 ssh2_pkt_adduint32(0);
1095 pktout.savedpos = pktout.length;
1097 static void ssh2_pkt_addstring_str(char *data)
1099 ssh2_pkt_adddata(data, strlen(data));
1100 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1101 pktout.length - pktout.savedpos);
1103 static void ssh2_pkt_addstring_data(char *data, int len)
1105 ssh2_pkt_adddata(data, len);
1106 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1107 pktout.length - pktout.savedpos);
1109 static void ssh2_pkt_addstring(char *data)
1111 ssh2_pkt_addstring_start();
1112 ssh2_pkt_addstring_str(data);
1114 static char *ssh2_mpint_fmt(Bignum b, int *len)
1117 int i, n = (bignum_bitcount(b) + 7) / 8;
1120 fatalbox("out of memory");
1122 for (i = 1; i <= n; i++)
1123 p[i] = bignum_byte(b, n - i);
1125 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1127 memmove(p, p + i, n + 1 - i);
1131 static void ssh2_pkt_addmp(Bignum b)
1135 p = ssh2_mpint_fmt(b, &len);
1136 ssh2_pkt_addstring_start();
1137 ssh2_pkt_addstring_data(p, len);
1142 * Construct an SSH2 final-form packet: compress it, encrypt it,
1143 * put the MAC on it. Final packet, ready to be sent, is stored in
1144 * pktout.data. Total length is returned.
1146 static int ssh2_pkt_construct(void)
1148 int cipherblk, maclen, padding, i;
1149 static unsigned long outgoing_sequence = 0;
1152 * Compress packet payload.
1155 debug(("Pre-compression payload:\n"));
1156 dmemdump(pktout.data + 5, pktout.length - 5);
1159 unsigned char *newpayload;
1161 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1162 &newpayload, &newlen)) {
1164 ssh2_pkt_adddata(newpayload, newlen);
1170 * Add padding. At least four bytes, and must also bring total
1171 * length (minus MAC) up to a multiple of the block size.
1173 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1174 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1177 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1178 maclen = csmac ? csmac->len : 0;
1179 ssh2_pkt_ensure(pktout.length + padding + maclen);
1180 pktout.data[4] = padding;
1181 for (i = 0; i < padding; i++)
1182 pktout.data[pktout.length + i] = random_byte();
1183 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1185 csmac->generate(pktout.data, pktout.length + padding,
1187 outgoing_sequence++; /* whether or not we MACed */
1190 debug(("Sending packet len=%d\n", pktout.length + padding));
1191 dmemdump(pktout.data, pktout.length + padding);
1195 cscipher->encrypt(pktout.data, pktout.length + padding);
1197 /* Ready-to-send packet starts at pktout.data. We return length. */
1198 return pktout.length + padding + maclen;
1202 * Construct and send an SSH2 packet immediately.
1204 static void ssh2_pkt_send(void)
1206 int len = ssh2_pkt_construct();
1207 sk_write(s, pktout.data, len);
1211 * Construct an SSH2 packet and add it to a deferred data block.
1212 * Useful for sending multiple packets in a single sk_write() call,
1213 * to prevent a traffic-analysing listener from being able to work
1214 * out the length of any particular packet (such as the password
1217 * Note that because SSH2 sequence-numbers its packets, this can
1218 * NOT be used as an m4-style `defer' allowing packets to be
1219 * constructed in one order and sent in another.
1221 static void ssh2_pkt_defer(void)
1223 int len = ssh2_pkt_construct();
1224 if (deferred_len + len > deferred_size) {
1225 deferred_size = deferred_len + len + 128;
1226 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1228 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1229 deferred_len += len;
1233 * Send the whole deferred data block constructed by
1234 * ssh2_pkt_defer() or SSH1's defer_packet().
1236 static void ssh_pkt_defersend(void)
1238 sk_write(s, deferred_send_data, deferred_len);
1239 deferred_len = deferred_size = 0;
1240 sfree(deferred_send_data);
1241 deferred_send_data = NULL;
1245 void bndebug(char *string, Bignum b)
1249 p = ssh2_mpint_fmt(b, &len);
1250 debug(("%s", string));
1251 for (i = 0; i < len; i++)
1252 debug((" %02x", p[i]));
1258 static void sha_mpint(SHA_State * s, Bignum b)
1262 p = ssh2_mpint_fmt(b, &len);
1263 sha_string(s, p, len);
1268 * SSH2 packet decode functions.
1270 static unsigned long ssh2_pkt_getuint32(void)
1272 unsigned long value;
1273 if (pktin.length - pktin.savedpos < 4)
1274 return 0; /* arrgh, no way to decline (FIXME?) */
1275 value = GET_32BIT(pktin.data + pktin.savedpos);
1276 pktin.savedpos += 4;
1279 static int ssh2_pkt_getbool(void)
1281 unsigned long value;
1282 if (pktin.length - pktin.savedpos < 1)
1283 return 0; /* arrgh, no way to decline (FIXME?) */
1284 value = pktin.data[pktin.savedpos] != 0;
1288 static void ssh2_pkt_getstring(char **p, int *length)
1291 if (pktin.length - pktin.savedpos < 4)
1293 *length = GET_32BIT(pktin.data + pktin.savedpos);
1294 pktin.savedpos += 4;
1295 if (pktin.length - pktin.savedpos < *length)
1297 *p = pktin.data + pktin.savedpos;
1298 pktin.savedpos += *length;
1300 static Bignum ssh2_pkt_getmp(void)
1306 ssh2_pkt_getstring(&p, &length);
1310 bombout(("internal error: Can't handle negative mpints"));
1313 b = bignum_from_bytes(p, length);
1318 * Examine the remote side's version string and compare it against
1319 * a list of known buggy implementations.
1321 static void ssh_detect_bugs(char *vstring)
1323 char *imp; /* pointer to implementation part */
1325 imp += strcspn(imp, "-");
1328 imp += strcspn(imp, "-");
1332 ssh_remote_bugs = 0;
1334 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1335 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1336 !strcmp(imp, "1.2.22")) {
1338 * These versions don't support SSH1_MSG_IGNORE, so we have
1339 * to use a different defence against password length
1342 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1343 logevent("We believe remote version has SSH1 ignore bug");
1346 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1347 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1348 !strncmp(imp, "2.1 ", 4)) {
1350 * These versions have the HMAC bug.
1352 ssh_remote_bugs |= BUG_SSH2_HMAC;
1353 logevent("We believe remote version has SSH2 HMAC bug");
1357 static int do_ssh_init(unsigned char c)
1360 static char version[10];
1361 static char *vstring;
1362 static int vstrsize;
1368 /* Search for the string "SSH-" in the input. */
1371 static const int transS[] = { 1, 2, 2, 1 };
1372 static const int transH[] = { 0, 0, 3, 0 };
1373 static const int transminus[] = { 0, 0, 0, -1 };
1384 crReturn(1); /* get another character */
1387 vstring = smalloc(16);
1389 strcpy(vstring, "SSH-");
1393 crReturn(1); /* get another char */
1394 if (vslen >= vstrsize - 1) {
1396 vstring = srealloc(vstring, vstrsize);
1398 vstring[vslen++] = c;
1403 } else if (i < sizeof(version) - 1)
1405 } else if (c == '\n')
1409 ssh_agentfwd_enabled = FALSE;
1410 rdpkt2_state.incoming_sequence = 0;
1413 vlog = smalloc(20 + vslen);
1414 sprintf(vlog, "Server version: %s", vstring);
1415 ssh_detect_bugs(vstring);
1416 vlog[strcspn(vlog, "\r\n")] = '\0';
1421 * Server version "1.99" means we can choose whether we use v1
1422 * or v2 protocol. Choice is based on cfg.sshprot.
1424 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1426 * This is a v2 server. Begin v2 protocol.
1428 char verstring[80], vlog[100];
1429 sprintf(verstring, "SSH-2.0-%s", sshver);
1430 SHA_Init(&exhashbase);
1432 * Hash our version string and their version string.
1434 sha_string(&exhashbase, verstring, strlen(verstring));
1435 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1436 sprintf(vlog, "We claim version: %s", verstring);
1438 strcat(verstring, "\n");
1439 logevent("Using SSH protocol version 2");
1440 sk_write(s, verstring, strlen(verstring));
1441 ssh_protocol = ssh2_protocol;
1443 s_rdpkt = ssh2_rdpkt;
1446 * This is a v1 server. Begin v1 protocol.
1448 char verstring[80], vlog[100];
1449 sprintf(verstring, "SSH-%s-%s",
1450 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1452 sprintf(vlog, "We claim version: %s", verstring);
1454 strcat(verstring, "\n");
1455 logevent("Using SSH protocol version 1");
1456 sk_write(s, verstring, strlen(verstring));
1457 ssh_protocol = ssh1_protocol;
1459 s_rdpkt = ssh1_rdpkt;
1461 ssh_state = SSH_STATE_BEFORE_SIZE;
1468 static void ssh_gotdata(unsigned char *data, int datalen)
1473 * To begin with, feed the characters one by one to the
1474 * protocol initialisation / selection function do_ssh_init().
1475 * When that returns 0, we're done with the initial greeting
1476 * exchange and can move on to packet discipline.
1481 crReturnV; /* more data please */
1482 ret = do_ssh_init(*data);
1490 * We emerge from that loop when the initial negotiation is
1491 * over and we have selected an s_rdpkt function. Now pass
1492 * everything to s_rdpkt, and then pass the resulting packets
1493 * to the proper protocol handler.
1498 while (datalen > 0) {
1499 if (s_rdpkt(&data, &datalen) == 0) {
1500 ssh_protocol(NULL, 0, 1);
1501 if (ssh_state == SSH_STATE_CLOSED) {
1511 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1514 ssh_state = SSH_STATE_CLOSED;
1520 /* A socket error has occurred. */
1521 connection_fatal(error_msg);
1523 /* Otherwise, the remote side closed the connection normally. */
1528 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1530 ssh_gotdata(data, len);
1531 if (ssh_state == SSH_STATE_CLOSED) {
1542 * Connect to specified host and port.
1543 * Returns an error message, or NULL on success.
1544 * Also places the canonical host name into `realhost'. It must be
1545 * freed by the caller.
1547 static char *connect_to_host(char *host, int port, char **realhost)
1549 static struct plug_function_table fn_table = {
1552 }, *fn_table_ptr = &fn_table;
1561 savedhost = smalloc(1 + strlen(host));
1563 fatalbox("Out of memory");
1564 strcpy(savedhost, host);
1567 port = 22; /* default ssh port */
1580 addr = sk_namelookup(host, realhost);
1581 if ((err = sk_addr_error(addr)))
1585 *realhost = strdup(FWhost);
1591 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1592 if ((err = sk_socket_error(s)))
1596 sk_write(s, "connect ", 8);
1597 sk_write(s, FWhost, strlen(FWhost));
1600 sprintf(buf, " %d\n", FWport);
1601 sk_write(s, buf, strlen(buf));
1609 * Handle the key exchange and user authentication phases.
1611 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1615 static unsigned char *rsabuf, *keystr1, *keystr2;
1616 unsigned char cookie[8];
1617 struct RSAKey servkey, hostkey;
1618 struct MD5Context md5c;
1619 static unsigned long supported_ciphers_mask, supported_auths_mask;
1620 static int tried_publickey;
1621 static unsigned char session_id[16];
1622 static int cipher_type;
1623 static char username[100];
1630 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1631 bombout(("Public key packet not received"));
1635 logevent("Received public keys");
1637 memcpy(cookie, pktin.body, 8);
1639 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1640 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1643 * Log the host key fingerprint.
1647 logevent("Host key fingerprint is:");
1648 strcpy(logmsg, " ");
1649 hostkey.comment = NULL;
1650 rsa_fingerprint(logmsg + strlen(logmsg),
1651 sizeof(logmsg) - strlen(logmsg), &hostkey);
1655 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1656 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1657 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1659 ssh1_local_protoflags =
1660 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1661 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1664 MD5Update(&md5c, keystr2, hostkey.bytes);
1665 MD5Update(&md5c, keystr1, servkey.bytes);
1666 MD5Update(&md5c, pktin.body, 8);
1667 MD5Final(session_id, &md5c);
1669 for (i = 0; i < 32; i++)
1670 session_key[i] = random_byte();
1672 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1674 rsabuf = smalloc(len);
1676 fatalbox("Out of memory");
1679 * Verify the host key.
1683 * First format the key into a string.
1685 int len = rsastr_len(&hostkey);
1686 char fingerprint[100];
1687 char *keystr = smalloc(len);
1689 fatalbox("Out of memory");
1690 rsastr_fmt(keystr, &hostkey);
1691 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1692 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1697 for (i = 0; i < 32; i++) {
1698 rsabuf[i] = session_key[i];
1700 rsabuf[i] ^= session_id[i];
1703 if (hostkey.bytes > servkey.bytes) {
1704 rsaencrypt(rsabuf, 32, &servkey);
1705 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1707 rsaencrypt(rsabuf, 32, &hostkey);
1708 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1711 logevent("Encrypted session key");
1713 switch (cfg.cipher) {
1714 case CIPHER_BLOWFISH:
1715 cipher_type = SSH_CIPHER_BLOWFISH;
1718 cipher_type = SSH_CIPHER_DES;
1721 cipher_type = SSH_CIPHER_3DES;
1724 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1725 cipher_type = SSH_CIPHER_3DES;
1728 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1730 ("Selected cipher not supported, falling back to 3DES\r\n");
1731 cipher_type = SSH_CIPHER_3DES;
1732 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1733 bombout(("Server violates SSH 1 protocol by "
1734 "not supporting 3DES encryption"));
1738 switch (cipher_type) {
1739 case SSH_CIPHER_3DES:
1740 logevent("Using 3DES encryption");
1742 case SSH_CIPHER_DES:
1743 logevent("Using single-DES encryption");
1745 case SSH_CIPHER_BLOWFISH:
1746 logevent("Using Blowfish encryption");
1750 send_packet(SSH1_CMSG_SESSION_KEY,
1751 PKT_CHAR, cipher_type,
1752 PKT_DATA, cookie, 8,
1753 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1754 PKT_DATA, rsabuf, len,
1755 PKT_INT, ssh1_local_protoflags, PKT_END);
1757 logevent("Trying to enable encryption...");
1761 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1762 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
1763 cipher->sesskey(session_key);
1767 if (pktin.type != SSH1_SMSG_SUCCESS) {
1768 bombout(("Encryption not successfully enabled"));
1772 logevent("Successfully started encryption");
1778 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1780 if (!ssh_get_line("login as: ",
1781 username, sizeof(username), FALSE)) {
1783 * get_line failed to get a username.
1786 logevent("No username provided. Abandoning session.");
1787 ssh_state = SSH_STATE_CLOSED;
1791 c_write_str("login as: ");
1794 crWaitUntil(!ispkt);
1796 switch (c = *in++) {
1805 c_write_str("\b \b");
1812 c_write_str("\b \b");
1822 if (((c >= ' ' && c <= '~') ||
1823 ((unsigned char) c >= 160))
1824 && pos < sizeof(username)-1) {
1825 username[pos++] = c;
1831 c_write_str("\r\n");
1832 username[strcspn(username, "\n\r")] = '\0';
1835 strncpy(username, cfg.username, 99);
1836 username[99] = '\0';
1839 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1841 char userlog[22 + sizeof(username)];
1842 sprintf(userlog, "Sent username \"%s\"", username);
1844 if (flags & FLAG_INTERACTIVE &&
1845 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1846 strcat(userlog, "\r\n");
1847 c_write_str(userlog);
1854 tried_publickey = 0;
1856 while (pktin.type == SSH1_SMSG_FAILURE) {
1857 static char password[100];
1858 static char prompt[200];
1861 static int pwpkt_type;
1863 * Show password prompt, having first obtained it via a TIS
1864 * or CryptoCard exchange if we're doing TIS or CryptoCard
1867 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1868 if (agent_exists()) {
1870 * Attempt RSA authentication using Pageant.
1872 static unsigned char request[5], *response, *p;
1873 static int responselen;
1874 static int i, nkeys;
1875 static int authed = FALSE;
1878 logevent("Pageant is running. Requesting keys.");
1880 /* Request the keys held by the agent. */
1881 PUT_32BIT(request, 1);
1882 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1883 agent_query(request, 5, &r, &responselen);
1884 response = (unsigned char *) r;
1885 if (response && responselen >= 5 &&
1886 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
1888 nkeys = GET_32BIT(p);
1892 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1895 for (i = 0; i < nkeys; i++) {
1896 static struct RSAKey key;
1897 static Bignum challenge;
1898 static char *commentp;
1899 static int commentlen;
1903 sprintf(buf, "Trying Pageant key #%d", i);
1907 p += ssh1_read_bignum(p, &key.exponent);
1908 p += ssh1_read_bignum(p, &key.modulus);
1909 commentlen = GET_32BIT(p);
1913 send_packet(SSH1_CMSG_AUTH_RSA,
1914 PKT_BIGNUM, key.modulus, PKT_END);
1916 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1917 logevent("Key refused");
1920 logevent("Received RSA challenge");
1921 ssh1_read_bignum(pktin.body, &challenge);
1923 char *agentreq, *q, *ret;
1926 len = 1 + 4; /* message type, bit count */
1927 len += ssh1_bignum_length(key.exponent);
1928 len += ssh1_bignum_length(key.modulus);
1929 len += ssh1_bignum_length(challenge);
1930 len += 16; /* session id */
1931 len += 4; /* response format */
1932 agentreq = smalloc(4 + len);
1933 PUT_32BIT(agentreq, len);
1935 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1936 PUT_32BIT(q, bignum_bitcount(key.modulus));
1938 q += ssh1_write_bignum(q, key.exponent);
1939 q += ssh1_write_bignum(q, key.modulus);
1940 q += ssh1_write_bignum(q, challenge);
1941 memcpy(q, session_id, 16);
1943 PUT_32BIT(q, 1); /* response format */
1944 agent_query(agentreq, len + 4, &vret, &retlen);
1948 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1949 logevent("Sending Pageant's response");
1950 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1951 PKT_DATA, ret + 5, 16,
1955 if (pktin.type == SSH1_SMSG_SUCCESS) {
1957 ("Pageant's response accepted");
1958 if (flags & FLAG_VERBOSE) {
1960 ("Authenticated using RSA key \"");
1961 c_write(commentp, commentlen);
1962 c_write_str("\" from agent\r\n");
1967 ("Pageant's response not accepted");
1970 ("Pageant failed to answer challenge");
1974 logevent("No reply received from Pageant");
1977 freebn(key.exponent);
1978 freebn(key.modulus);
1987 if (*cfg.keyfile && !tried_publickey)
1988 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1990 if (pktin.type == SSH1_SMSG_FAILURE &&
1992 (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
1993 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1994 logevent("Requested TIS authentication");
1995 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1997 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1998 logevent("TIS authentication declined");
1999 if (flags & FLAG_INTERACTIVE)
2000 c_write_str("TIS authentication refused.\r\n");
2002 int challengelen = ((pktin.body[0] << 24) |
2003 (pktin.body[1] << 16) |
2004 (pktin.body[2] << 8) |
2006 logevent("Received TIS challenge");
2007 if (challengelen > sizeof(prompt) - 1)
2008 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2009 memcpy(prompt, pktin.body + 4, challengelen);
2010 prompt[challengelen] = '\0';
2013 if (pktin.type == SSH1_SMSG_FAILURE &&
2015 (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
2016 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2017 logevent("Requested CryptoCard authentication");
2018 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2020 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2021 logevent("CryptoCard authentication declined");
2022 c_write_str("CryptoCard authentication refused.\r\n");
2024 int challengelen = ((pktin.body[0] << 24) |
2025 (pktin.body[1] << 16) |
2026 (pktin.body[2] << 8) |
2028 logevent("Received CryptoCard challenge");
2029 if (challengelen > sizeof(prompt) - 1)
2030 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2031 memcpy(prompt, pktin.body + 4, challengelen);
2032 strncpy(prompt + challengelen, "\r\nResponse : ",
2033 sizeof(prompt) - challengelen);
2034 prompt[sizeof(prompt) - 1] = '\0';
2037 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2038 sprintf(prompt, "%.90s@%.90s's password: ",
2039 username, savedhost);
2041 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2042 char *comment = NULL;
2043 if (flags & FLAG_VERBOSE)
2044 c_write_str("Trying public key authentication.\r\n");
2045 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2046 if (flags & FLAG_VERBOSE)
2047 c_write_str("No passphrase required.\r\n");
2050 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2055 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2057 * get_line failed to get a password (for example
2058 * because one was supplied on the command line
2059 * which has already failed to work). Terminate.
2061 send_packet(SSH1_MSG_DISCONNECT,
2062 PKT_STR, "No more passwords available to try",
2064 connection_fatal("Unable to authenticate");
2065 ssh_state = SSH_STATE_CLOSED;
2069 c_write_str(prompt);
2073 crWaitUntil(!ispkt);
2075 switch (c = *in++) {
2096 if (pos < sizeof(password)-1)
2097 password[pos++] = c;
2101 c_write_str("\r\n");
2105 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2107 * Try public key authentication with the specified
2110 static struct RSAKey pubkey;
2111 static Bignum challenge, response;
2113 static unsigned char buffer[32];
2115 tried_publickey = 1;
2116 i = loadrsakey(cfg.keyfile, &pubkey, password);
2118 c_write_str("Couldn't load public key from ");
2119 c_write_str(cfg.keyfile);
2120 c_write_str(".\r\n");
2121 continue; /* go and try password */
2124 c_write_str("Wrong passphrase.\r\n");
2125 tried_publickey = 0;
2126 continue; /* try again */
2130 * Send a public key attempt.
2132 send_packet(SSH1_CMSG_AUTH_RSA,
2133 PKT_BIGNUM, pubkey.modulus, PKT_END);
2136 if (pktin.type == SSH1_SMSG_FAILURE) {
2137 c_write_str("Server refused our public key.\r\n");
2138 continue; /* go and try password */
2140 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2141 bombout(("Bizarre response to offer of public key"));
2144 ssh1_read_bignum(pktin.body, &challenge);
2145 response = rsadecrypt(challenge, &pubkey);
2146 freebn(pubkey.private_exponent); /* burn the evidence */
2148 for (i = 0; i < 32; i++) {
2149 buffer[i] = bignum_byte(response, 31 - i);
2153 MD5Update(&md5c, buffer, 32);
2154 MD5Update(&md5c, session_id, 16);
2155 MD5Final(buffer, &md5c);
2157 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2158 PKT_DATA, buffer, 16, PKT_END);
2161 if (pktin.type == SSH1_SMSG_FAILURE) {
2162 if (flags & FLAG_VERBOSE)
2164 ("Failed to authenticate with our public key.\r\n");
2165 continue; /* go and try password */
2166 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2168 ("Bizarre response to RSA authentication response"));
2172 break; /* we're through! */
2174 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2176 * Defence against traffic analysis: we send a
2177 * whole bunch of packets containing strings of
2178 * different lengths. One of these strings is the
2179 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2180 * The others are all random data in
2181 * SSH1_MSG_IGNORE packets. This way a passive
2182 * listener can't tell which is the password, and
2183 * hence can't deduce the password length.
2185 * Anybody with a password length greater than 16
2186 * bytes is going to have enough entropy in their
2187 * password that a listener won't find it _that_
2188 * much help to know how long it is. So what we'll
2191 * - if password length < 16, we send 15 packets
2192 * containing string lengths 1 through 15
2194 * - otherwise, we let N be the nearest multiple
2195 * of 8 below the password length, and send 8
2196 * packets containing string lengths N through
2197 * N+7. This won't obscure the order of
2198 * magnitude of the password length, but it will
2199 * introduce a bit of extra uncertainty.
2201 * A few servers (the old 1.2.18 through 1.2.22)
2202 * can't deal with SSH1_MSG_IGNORE. For these
2203 * servers, we need an alternative defence. We make
2204 * use of the fact that the password is interpreted
2205 * as a C string: so we can append a NUL, then some
2208 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2213 len = strlen(password);
2214 if (len < sizeof(string)) {
2216 strcpy(string, password);
2217 len++; /* cover the zero byte */
2218 while (len < sizeof(string)) {
2219 string[len++] = (char) random_byte();
2224 send_packet(pwpkt_type, PKT_INT, len,
2225 PKT_DATA, s, len, PKT_END);
2227 int bottom, top, pwlen, i;
2230 pwlen = strlen(password);
2232 bottom = 0; /* zero length passwords are OK! :-) */
2235 bottom = pwlen & ~7;
2239 assert(pwlen >= bottom && pwlen <= top);
2241 randomstr = smalloc(top + 1);
2243 for (i = bottom; i <= top; i++) {
2245 defer_packet(pwpkt_type, PKT_STR, password,
2248 for (j = 0; j < i; j++) {
2250 randomstr[j] = random_byte();
2251 } while (randomstr[j] == '\0');
2253 randomstr[i] = '\0';
2254 defer_packet(SSH1_MSG_IGNORE,
2255 PKT_STR, randomstr, PKT_END);
2258 ssh_pkt_defersend();
2261 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2264 logevent("Sent password");
2265 memset(password, 0, strlen(password));
2267 if (pktin.type == SSH1_SMSG_FAILURE) {
2268 if (flags & FLAG_VERBOSE)
2269 c_write_str("Access denied\r\n");
2270 logevent("Authentication refused");
2271 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2272 logevent("Received disconnect request");
2273 ssh_state = SSH_STATE_CLOSED;
2275 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2276 bombout(("Strange packet received, type %d", pktin.type));
2281 logevent("Authentication successful");
2286 void sshfwd_close(struct ssh_channel *c)
2288 if (c && !c->closes) {
2289 if (ssh_version == 1) {
2290 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2293 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2294 ssh2_pkt_adduint32(c->remoteid);
2298 if (c->type == CHAN_X11) {
2300 logevent("Forwarded X11 connection terminated");
2301 } else if (c->type == CHAN_SOCKDATA) {
2303 logevent("Forwarded port closed");
2308 void sshfwd_write(struct ssh_channel *c, char *buf, int len)
2310 if (ssh_version == 1) {
2311 send_packet(SSH1_MSG_CHANNEL_DATA,
2312 PKT_INT, c->remoteid,
2313 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2315 ssh2_add_channel_data(c, buf, len);
2320 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2326 while (!do_ssh1_login(in, inlen, ispkt)) {
2329 if (ssh_state == SSH_STATE_CLOSED)
2332 if (cfg.agentfwd && agent_exists()) {
2333 logevent("Requesting agent forwarding");
2334 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2338 if (pktin.type != SSH1_SMSG_SUCCESS
2339 && pktin.type != SSH1_SMSG_FAILURE) {
2340 bombout(("Protocol confusion"));
2342 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2343 logevent("Agent forwarding refused");
2345 logevent("Agent forwarding enabled");
2346 ssh_agentfwd_enabled = TRUE;
2350 if (cfg.x11_forward) {
2351 char proto[20], data[64];
2352 logevent("Requesting X11 forwarding");
2353 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2354 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2355 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2356 PKT_STR, proto, PKT_STR, data,
2357 PKT_INT, 0, PKT_END);
2359 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2360 PKT_STR, proto, PKT_STR, data, PKT_END);
2365 if (pktin.type != SSH1_SMSG_SUCCESS
2366 && pktin.type != SSH1_SMSG_FAILURE) {
2367 bombout(("Protocol confusion"));
2369 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2370 logevent("X11 forwarding refused");
2372 logevent("X11 forwarding enabled");
2373 ssh_X11_fwd_enabled = TRUE;
2381 char sports[256], dports[256], host[256];
2384 ssh_rportfwds = newtree234(ssh_rportcmp);
2385 /* Add port forwardings. */
2390 while (*e && *e != '\t')
2396 while (*e && *e != ':')
2406 dport = atoi(dports);
2407 sport = atoi(sports);
2408 if (sport && dport) {
2410 pfd_addforward(host, dport, sport);
2411 sprintf(buf, "Local port %d forwarding to %s:%d",
2412 sport, host, dport);
2415 struct ssh_rportfwd *pf;
2416 pf = smalloc(sizeof(*pf));
2417 strcpy(pf->host, host);
2419 if (add234(ssh_rportfwds, pf) != pf) {
2421 "Duplicate remote port forwarding to %s:%s",
2425 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2426 sport, host, dport);
2428 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2440 send_packet(SSH1_CMSG_REQUEST_PTY,
2441 PKT_STR, cfg.termtype,
2442 PKT_INT, rows, PKT_INT, cols,
2443 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2444 ssh_state = SSH_STATE_INTERMED;
2448 if (pktin.type != SSH1_SMSG_SUCCESS
2449 && pktin.type != SSH1_SMSG_FAILURE) {
2450 bombout(("Protocol confusion"));
2452 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2453 c_write_str("Server refused to allocate pty\r\n");
2454 ssh_editing = ssh_echoing = 1;
2456 logevent("Allocated pty");
2458 ssh_editing = ssh_echoing = 1;
2461 if (cfg.compression) {
2462 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2466 if (pktin.type != SSH1_SMSG_SUCCESS
2467 && pktin.type != SSH1_SMSG_FAILURE) {
2468 bombout(("Protocol confusion"));
2470 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2471 c_write_str("Server refused to compress\r\n");
2473 logevent("Started compression");
2474 ssh1_compressing = TRUE;
2475 zlib_compress_init();
2476 zlib_decompress_init();
2479 if (*cfg.remote_cmd_ptr)
2480 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr,
2483 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2484 logevent("Started session");
2486 ssh_state = SSH_STATE_SESSION;
2490 ssh_special(TS_EOF);
2492 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2494 ssh_channels = newtree234(ssh_channelcmp);
2498 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2499 pktin.type == SSH1_SMSG_STDERR_DATA) {
2500 long len = GET_32BIT(pktin.body);
2501 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2502 pktin.body + 4, len);
2503 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2504 ssh_state = SSH_STATE_CLOSED;
2505 logevent("Received disconnect request");
2507 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2508 /* Remote side is trying to open a channel to talk to our
2509 * X-Server. Give them back a local channel number. */
2510 struct ssh_channel *c;
2512 logevent("Received X11 connect request");
2513 /* Refuse if X11 forwarding is disabled. */
2514 if (!ssh_X11_fwd_enabled) {
2515 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2516 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2517 logevent("Rejected X11 connect request");
2519 c = smalloc(sizeof(struct ssh_channel));
2521 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2522 logevent("opening X11 forward connection failed");
2524 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2525 PKT_INT, GET_32BIT(pktin.body),
2529 ("opening X11 forward connection succeeded");
2530 c->remoteid = GET_32BIT(pktin.body);
2531 c->localid = alloc_channel_id();
2533 c->type = CHAN_X11; /* identify channel type */
2534 add234(ssh_channels, c);
2535 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2536 PKT_INT, c->remoteid, PKT_INT,
2537 c->localid, PKT_END);
2538 logevent("Opened X11 forward channel");
2541 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2542 /* Remote side is trying to open a channel to talk to our
2543 * agent. Give them back a local channel number. */
2544 struct ssh_channel *c;
2546 /* Refuse if agent forwarding is disabled. */
2547 if (!ssh_agentfwd_enabled) {
2548 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2549 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2551 c = smalloc(sizeof(struct ssh_channel));
2552 c->remoteid = GET_32BIT(pktin.body);
2553 c->localid = alloc_channel_id();
2555 c->type = CHAN_AGENT; /* identify channel type */
2556 c->u.a.lensofar = 0;
2557 add234(ssh_channels, c);
2558 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2559 PKT_INT, c->remoteid, PKT_INT, c->localid,
2562 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2563 /* Remote side is trying to open a channel to talk to a
2564 * forwarded port. Give them back a local channel number. */
2565 struct ssh_channel *c;
2566 struct ssh_rportfwd pf;
2568 char host[256], buf[1024];
2570 c = smalloc(sizeof(struct ssh_channel));
2572 hostsize = GET_32BIT(pktin.body+4);
2573 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2574 if (h+1 < host+sizeof(host))
2579 port = GET_32BIT(p);
2581 strcpy(pf.host, host);
2584 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2585 sprintf(buf, "Rejected remote port open request for %s:%d",
2588 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2589 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2591 sprintf(buf, "Received remote port open request for %s:%d",
2594 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2597 sprintf(buf, "Port open failed: %s", e);
2600 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2601 PKT_INT, GET_32BIT(pktin.body),
2604 c->remoteid = GET_32BIT(pktin.body);
2605 c->localid = alloc_channel_id();
2607 c->type = CHAN_SOCKDATA; /* identify channel type */
2608 add234(ssh_channels, c);
2609 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2610 PKT_INT, c->remoteid, PKT_INT,
2611 c->localid, PKT_END);
2612 logevent("Forwarded port opened successfully");
2616 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
2617 unsigned int remoteid = GET_32BIT(pktin.body);
2618 unsigned int localid = GET_32BIT(pktin.body+4);
2619 struct ssh_channel *c;
2621 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2623 c->remoteid = localid;
2624 pfd_confirm(c->u.pfd.s);
2629 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2630 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2631 /* Remote side closes a channel. */
2632 unsigned i = GET_32BIT(pktin.body);
2633 struct ssh_channel *c;
2634 c = find234(ssh_channels, &i, ssh_channelfind);
2638 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2639 if (!(c->closes & closetype))
2640 send_packet(pktin.type, PKT_INT, c->remoteid,
2642 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2643 logevent("Forwarded X11 connection terminated");
2644 assert(c->u.x11.s != NULL);
2645 x11_close(c->u.x11.s);
2648 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
2649 logevent("Forwarded port closed");
2650 assert(c->u.pfd.s != NULL);
2651 pfd_close(c->u.pfd.s);
2654 c->closes |= closetype;
2655 if (c->closes == 3) {
2656 del234(ssh_channels, c);
2660 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2661 /* Data sent down one of our channels. */
2662 int i = GET_32BIT(pktin.body);
2663 int len = GET_32BIT(pktin.body + 4);
2664 unsigned char *p = pktin.body + 8;
2665 struct ssh_channel *c;
2666 c = find234(ssh_channels, &i, ssh_channelfind);
2670 x11_send(c->u.x11.s, p, len);
2673 pfd_send(c->u.pfd.s, p, len);
2676 /* Data for an agent message. Buffer it. */
2678 if (c->u.a.lensofar < 4) {
2679 int l = min(4 - c->u.a.lensofar, len);
2680 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2684 c->u.a.lensofar += l;
2686 if (c->u.a.lensofar == 4) {
2688 4 + GET_32BIT(c->u.a.msglen);
2689 c->u.a.message = smalloc(c->u.a.totallen);
2690 memcpy(c->u.a.message, c->u.a.msglen, 4);
2692 if (c->u.a.lensofar >= 4 && len > 0) {
2694 min(c->u.a.totallen - c->u.a.lensofar,
2696 memcpy(c->u.a.message + c->u.a.lensofar, p,
2700 c->u.a.lensofar += l;
2702 if (c->u.a.lensofar == c->u.a.totallen) {
2703 void *reply, *sentreply;
2705 agent_query(c->u.a.message,
2706 c->u.a.totallen, &reply,
2711 /* Fake SSH_AGENT_FAILURE. */
2712 sentreply = "\0\0\0\1\5";
2715 send_packet(SSH1_MSG_CHANNEL_DATA,
2716 PKT_INT, c->remoteid,
2718 PKT_DATA, sentreply, replylen,
2722 sfree(c->u.a.message);
2723 c->u.a.lensofar = 0;
2729 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2730 /* may be from EXEC_SHELL on some servers */
2731 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2732 /* may be from EXEC_SHELL on some servers
2733 * if no pty is available or in other odd cases. Ignore */
2734 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2735 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2737 bombout(("Strange packet received: type %d", pktin.type));
2742 int len = min(inlen, 512);
2743 send_packet(SSH1_CMSG_STDIN_DATA,
2744 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2755 * Utility routine for decoding comma-separated strings in KEXINIT.
2757 static int in_commasep_string(char *needle, char *haystack, int haylen)
2759 int needlen = strlen(needle);
2762 * Is it at the start of the string?
2764 if (haylen >= needlen && /* haystack is long enough */
2765 !memcmp(needle, haystack, needlen) && /* initial match */
2766 (haylen == needlen || haystack[needlen] == ',')
2767 /* either , or EOS follows */
2771 * If not, search for the next comma and resume after that.
2772 * If no comma found, terminate.
2774 while (haylen > 0 && *haystack != ',')
2775 haylen--, haystack++;
2778 haylen--, haystack++; /* skip over comma itself */
2783 * SSH2 key creation method.
2785 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
2789 /* First 20 bytes. */
2792 SHA_Bytes(&s, H, 20);
2793 SHA_Bytes(&s, &chr, 1);
2794 SHA_Bytes(&s, sessid, 20);
2795 SHA_Final(&s, keyspace);
2796 /* Next 20 bytes. */
2799 SHA_Bytes(&s, H, 20);
2800 SHA_Bytes(&s, keyspace, 20);
2801 SHA_Final(&s, keyspace + 20);
2805 * Handle the SSH2 transport layer.
2807 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2809 static int i, j, len, nbits, pbits;
2811 static Bignum p, g, e, f, K;
2812 static int kex_init_value, kex_reply_value;
2813 static const struct ssh_mac **maclist;
2815 static const struct ssh2_cipher *cscipher_tobe = NULL;
2816 static const struct ssh2_cipher *sccipher_tobe = NULL;
2817 static const struct ssh_mac *csmac_tobe = NULL;
2818 static const struct ssh_mac *scmac_tobe = NULL;
2819 static const struct ssh_compress *cscomp_tobe = NULL;
2820 static const struct ssh_compress *sccomp_tobe = NULL;
2821 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2822 static int hostkeylen, siglen;
2823 static void *hkey; /* actual host key */
2824 static unsigned char exchange_hash[20];
2825 static unsigned char keyspace[40];
2826 static const struct ssh2_ciphers *preferred_cipher;
2827 static const struct ssh_compress *preferred_comp;
2828 static int first_kex;
2835 * Set up the preferred cipher and compression.
2837 if (cfg.cipher == CIPHER_BLOWFISH) {
2838 preferred_cipher = &ssh2_blowfish;
2839 } else if (cfg.cipher == CIPHER_DES) {
2840 logevent("Single DES not supported in SSH2; using 3DES");
2841 preferred_cipher = &ssh2_3des;
2842 } else if (cfg.cipher == CIPHER_3DES) {
2843 preferred_cipher = &ssh2_3des;
2844 } else if (cfg.cipher == CIPHER_AES) {
2845 preferred_cipher = &ssh2_aes;
2847 /* Shouldn't happen, but we do want to initialise to _something_. */
2848 preferred_cipher = &ssh2_3des;
2850 if (cfg.compression)
2851 preferred_comp = &ssh_zlib;
2853 preferred_comp = &ssh_comp_none;
2856 * Be prepared to work around the buggy MAC problem.
2858 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
2859 maclist = buggymacs, nmacs = lenof(buggymacs);
2861 maclist = macs, nmacs = lenof(macs);
2865 * Construct and send our key exchange packet.
2867 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2868 for (i = 0; i < 16; i++)
2869 ssh2_pkt_addbyte((unsigned char) random_byte());
2870 /* List key exchange algorithms. */
2871 ssh2_pkt_addstring_start();
2872 for (i = 0; i < lenof(kex_algs); i++) {
2873 ssh2_pkt_addstring_str(kex_algs[i]->name);
2874 if (i < lenof(kex_algs) - 1)
2875 ssh2_pkt_addstring_str(",");
2877 /* List server host key algorithms. */
2878 ssh2_pkt_addstring_start();
2879 for (i = 0; i < lenof(hostkey_algs); i++) {
2880 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2881 if (i < lenof(hostkey_algs) - 1)
2882 ssh2_pkt_addstring_str(",");
2884 /* List client->server encryption algorithms. */
2885 ssh2_pkt_addstring_start();
2886 for (i = 0; i < lenof(ciphers) + 1; i++) {
2887 const struct ssh2_ciphers *c =
2888 i == 0 ? preferred_cipher : ciphers[i - 1];
2889 for (j = 0; j < c->nciphers; j++) {
2890 ssh2_pkt_addstring_str(c->list[j]->name);
2891 if (i < lenof(ciphers) || j < c->nciphers - 1)
2892 ssh2_pkt_addstring_str(",");
2895 /* List server->client encryption algorithms. */
2896 ssh2_pkt_addstring_start();
2897 for (i = 0; i < lenof(ciphers) + 1; i++) {
2898 const struct ssh2_ciphers *c =
2899 i == 0 ? preferred_cipher : ciphers[i - 1];
2900 for (j = 0; j < c->nciphers; j++) {
2901 ssh2_pkt_addstring_str(c->list[j]->name);
2902 if (i < lenof(ciphers) || j < c->nciphers - 1)
2903 ssh2_pkt_addstring_str(",");
2906 /* List client->server MAC algorithms. */
2907 ssh2_pkt_addstring_start();
2908 for (i = 0; i < nmacs; i++) {
2909 ssh2_pkt_addstring_str(maclist[i]->name);
2911 ssh2_pkt_addstring_str(",");
2913 /* List server->client MAC algorithms. */
2914 ssh2_pkt_addstring_start();
2915 for (i = 0; i < nmacs; i++) {
2916 ssh2_pkt_addstring_str(maclist[i]->name);
2918 ssh2_pkt_addstring_str(",");
2920 /* List client->server compression algorithms. */
2921 ssh2_pkt_addstring_start();
2922 for (i = 0; i < lenof(compressions) + 1; i++) {
2923 const struct ssh_compress *c =
2924 i == 0 ? preferred_comp : compressions[i - 1];
2925 ssh2_pkt_addstring_str(c->name);
2926 if (i < lenof(compressions))
2927 ssh2_pkt_addstring_str(",");
2929 /* List server->client compression algorithms. */
2930 ssh2_pkt_addstring_start();
2931 for (i = 0; i < lenof(compressions) + 1; i++) {
2932 const struct ssh_compress *c =
2933 i == 0 ? preferred_comp : compressions[i - 1];
2934 ssh2_pkt_addstring_str(c->name);
2935 if (i < lenof(compressions))
2936 ssh2_pkt_addstring_str(",");
2938 /* List client->server languages. Empty list. */
2939 ssh2_pkt_addstring_start();
2940 /* List server->client languages. Empty list. */
2941 ssh2_pkt_addstring_start();
2942 /* First KEX packet does _not_ follow, because we're not that brave. */
2943 ssh2_pkt_addbool(FALSE);
2945 ssh2_pkt_adduint32(0);
2947 exhash = exhashbase;
2948 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
2954 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
2957 * Now examine the other side's KEXINIT to see what we're up
2960 if (pktin.type != SSH2_MSG_KEXINIT) {
2961 bombout(("expected key exchange packet from server"));
2966 cscipher_tobe = NULL;
2967 sccipher_tobe = NULL;
2972 pktin.savedpos += 16; /* skip garbage cookie */
2973 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2974 for (i = 0; i < lenof(kex_algs); i++) {
2975 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2980 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2981 for (i = 0; i < lenof(hostkey_algs); i++) {
2982 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2983 hostkey = hostkey_algs[i];
2987 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2988 for (i = 0; i < lenof(ciphers) + 1; i++) {
2989 const struct ssh2_ciphers *c =
2990 i == 0 ? preferred_cipher : ciphers[i - 1];
2991 for (j = 0; j < c->nciphers; j++) {
2992 if (in_commasep_string(c->list[j]->name, str, len)) {
2993 cscipher_tobe = c->list[j];
3000 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3001 for (i = 0; i < lenof(ciphers) + 1; i++) {
3002 const struct ssh2_ciphers *c =
3003 i == 0 ? preferred_cipher : ciphers[i - 1];
3004 for (j = 0; j < c->nciphers; j++) {
3005 if (in_commasep_string(c->list[j]->name, str, len)) {
3006 sccipher_tobe = c->list[j];
3013 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3014 for (i = 0; i < nmacs; i++) {
3015 if (in_commasep_string(maclist[i]->name, str, len)) {
3016 csmac_tobe = maclist[i];
3020 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3021 for (i = 0; i < nmacs; i++) {
3022 if (in_commasep_string(maclist[i]->name, str, len)) {
3023 scmac_tobe = maclist[i];
3027 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3028 for (i = 0; i < lenof(compressions) + 1; i++) {
3029 const struct ssh_compress *c =
3030 i == 0 ? preferred_comp : compressions[i - 1];
3031 if (in_commasep_string(c->name, str, len)) {
3036 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3037 for (i = 0; i < lenof(compressions) + 1; i++) {
3038 const struct ssh_compress *c =
3039 i == 0 ? preferred_comp : compressions[i - 1];
3040 if (in_commasep_string(c->name, str, len)) {
3047 * Work out the number of bits of key we will need from the key
3048 * exchange. We start with the maximum key length of either
3054 csbits = cscipher_tobe->keylen;
3055 scbits = sccipher_tobe->keylen;
3056 nbits = (csbits > scbits ? csbits : scbits);
3058 /* The keys only have 160-bit entropy, since they're based on
3059 * a SHA-1 hash. So cap the key size at 160 bits. */
3064 * If we're doing Diffie-Hellman group exchange, start by
3065 * requesting a group.
3067 if (kex == &ssh_diffiehellman_gex) {
3068 logevent("Doing Diffie-Hellman group exchange");
3070 * Work out how big a DH group we will need to allow that
3073 pbits = 512 << ((nbits - 1) / 64);
3074 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3075 ssh2_pkt_adduint32(pbits);
3079 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3080 bombout(("expected key exchange group packet from server"));
3083 p = ssh2_pkt_getmp();
3084 g = ssh2_pkt_getmp();
3085 dh_setup_group(p, g);
3086 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3087 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3090 kex_init_value = SSH2_MSG_KEXDH_INIT;
3091 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3094 logevent("Doing Diffie-Hellman key exchange");
3096 * Now generate and send e for Diffie-Hellman.
3098 e = dh_create_e(nbits * 2);
3099 ssh2_pkt_init(kex_init_value);
3104 if (pktin.type != kex_reply_value) {
3105 bombout(("expected key exchange reply packet from server"));
3108 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3109 f = ssh2_pkt_getmp();
3110 ssh2_pkt_getstring(&sigdata, &siglen);
3114 sha_string(&exhash, hostkeydata, hostkeylen);
3115 if (kex == &ssh_diffiehellman_gex) {
3116 sha_uint32(&exhash, pbits);
3117 sha_mpint(&exhash, p);
3118 sha_mpint(&exhash, g);
3120 sha_mpint(&exhash, e);
3121 sha_mpint(&exhash, f);
3122 sha_mpint(&exhash, K);
3123 SHA_Final(&exhash, exchange_hash);
3128 debug(("Exchange hash is:\n"));
3129 dmemdump(exchange_hash, 20);
3132 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3134 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3135 bombout(("Server's host key did not match the signature supplied"));
3140 * Expect SSH2_MSG_NEWKEYS from server.
3143 if (pktin.type != SSH2_MSG_NEWKEYS) {
3144 bombout(("expected new-keys packet from server"));
3149 * Authenticate remote host: verify host key. (We've already
3150 * checked the signature of the exchange hash.)
3152 keystr = hostkey->fmtkey(hkey);
3153 fingerprint = hostkey->fingerprint(hkey);
3154 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3155 keystr, fingerprint);
3156 if (first_kex) { /* don't bother logging this in rekeys */
3157 logevent("Host key fingerprint is:");
3158 logevent(fingerprint);
3162 hostkey->freekey(hkey);
3165 * Send SSH2_MSG_NEWKEYS.
3167 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3171 * Create and initialise session keys.
3173 cscipher = cscipher_tobe;
3174 sccipher = sccipher_tobe;
3177 cscomp = cscomp_tobe;
3178 sccomp = sccomp_tobe;
3179 cscomp->compress_init();
3180 sccomp->decompress_init();
3182 * Set IVs after keys. Here we use the exchange hash from the
3183 * _first_ key exchange.
3186 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3187 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3188 cscipher->setcskey(keyspace);
3189 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3190 sccipher->setsckey(keyspace);
3191 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3192 cscipher->setcsiv(keyspace);
3193 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3194 sccipher->setsciv(keyspace);
3195 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3196 csmac->setcskey(keyspace);
3197 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3198 scmac->setsckey(keyspace);
3201 * If this is the first key exchange phase, we must pass the
3202 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3203 * wants to see it but because it will need time to initialise
3204 * itself before it sees an actual packet. In subsequent key
3205 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3206 * it would only confuse the layer above.
3214 * Now we're encrypting. Begin returning 1 to the protocol main
3215 * function so that other things can run on top of the
3216 * transport. If we ever see a KEXINIT, we must go back to the
3219 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3222 logevent("Server initiated key re-exchange");
3223 goto begin_key_exchange;
3229 * Add data to an SSH2 channel output buffer.
3231 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3234 if (c->v2.outbufsize < c->v2.outbuflen + len) {
3235 c->v2.outbufsize = c->v2.outbuflen + len + 1024;
3236 c->v2.outbuffer = srealloc(c->v2.outbuffer, c->v2.outbufsize);
3238 memcpy(c->v2.outbuffer + c->v2.outbuflen, buf, len);
3239 c->v2.outbuflen += len;
3243 * Attempt to send data on an SSH2 channel.
3245 static void ssh2_try_send(struct ssh_channel *c)
3247 while (c->v2.remwindow > 0 && c->v2.outbuflen > 0) {
3248 unsigned len = c->v2.remwindow;
3249 if (len > c->v2.outbuflen)
3250 len = c->v2.outbuflen;
3251 if (len > c->v2.remmaxpkt)
3252 len = c->v2.remmaxpkt;
3253 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3254 ssh2_pkt_adduint32(c->remoteid);
3255 ssh2_pkt_addstring_start();
3256 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
3258 c->v2.outbuflen -= len;
3259 memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
3260 c->v2.remwindow -= len;
3265 * Handle the SSH2 userauth and connection layers.
3267 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3270 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3275 AUTH_TYPE_PUBLICKEY,
3276 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3277 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3280 static int gotit, need_pw, can_pubkey, can_passwd;
3281 static int tried_pubkey_config, tried_agent;
3282 static int we_are_in;
3283 static char username[100];
3284 static char pwprompt[200];
3285 static char password[100];
3290 * Request userauth protocol, and await a response to it.
3292 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3293 ssh2_pkt_addstring("ssh-userauth");
3295 crWaitUntilV(ispkt);
3296 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3297 bombout(("Server refused user authentication protocol"));
3302 * We repeat this whole loop, including the username prompt,
3303 * until we manage a successful authentication. If the user
3304 * types the wrong _password_, they are sent back to the
3305 * beginning to try another username. (If they specify a
3306 * username in the config, they are never asked, even if they
3307 * do give a wrong password.)
3309 * I think this best serves the needs of
3311 * - the people who have no configuration, no keys, and just
3312 * want to try repeated (username,password) pairs until they
3313 * type both correctly
3315 * - people who have keys and configuration but occasionally
3316 * need to fall back to passwords
3318 * - people with a key held in Pageant, who might not have
3319 * logged in to a particular machine before; so they want to
3320 * type a username, and then _either_ their key will be
3321 * accepted, _or_ they will type a password. If they mistype
3322 * the username they will want to be able to get back and
3333 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3335 if (!ssh_get_line("login as: ",
3336 username, sizeof(username), FALSE)) {
3338 * get_line failed to get a username.
3341 logevent("No username provided. Abandoning session.");
3342 ssh_state = SSH_STATE_CLOSED;
3346 c_write_str("login as: ");
3349 crWaitUntilV(!ispkt);
3351 switch (c = *in++) {
3360 c_write_str("\b \b");
3367 c_write_str("\b \b");
3377 if (((c >= ' ' && c <= '~') ||
3378 ((unsigned char) c >= 160))
3379 && pos < sizeof(username)-1) {
3380 username[pos++] = c;
3387 c_write_str("\r\n");
3388 username[strcspn(username, "\n\r")] = '\0';
3391 strncpy(username, cfg.username, 99);
3392 username[99] = '\0';
3393 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3394 sprintf(stuff, "Using username \"%s\".\r\n", username);
3400 * Send an authentication request using method "none": (a)
3401 * just in case it succeeds, and (b) so that we know what
3402 * authentication methods we can usefully try next.
3404 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3405 ssh2_pkt_addstring(username);
3406 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3407 ssh2_pkt_addstring("none"); /* method */
3409 type = AUTH_TYPE_NONE;
3413 tried_pubkey_config = FALSE;
3414 tried_agent = FALSE;
3418 * Wait for the result of the last authentication request.
3421 crWaitUntilV(ispkt);
3422 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3426 * Don't show the banner if we're operating in
3427 * non-verbose non-interactive mode. (It's probably
3428 * a script, which means nobody will read the
3429 * banner _anyway_, and moreover the printing of
3430 * the banner will screw up processing on the
3431 * output of (say) plink.)
3433 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3434 ssh2_pkt_getstring(&banner, &size);
3436 c_write_untrusted(banner, size);
3438 crWaitUntilV(ispkt);
3440 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3441 logevent("Access granted");
3446 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3448 ("Strange packet received during authentication: type %d",
3456 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3457 * we can look at the string in it and know what we can
3458 * helpfully try next.
3463 ssh2_pkt_getstring(&methods, &methlen);
3464 if (!ssh2_pkt_getbool()) {
3466 * We have received an unequivocal Access
3467 * Denied. This can translate to a variety of
3470 * - if we'd just tried "none" authentication,
3471 * it's not worth printing anything at all
3473 * - if we'd just tried a public key _offer_,
3474 * the message should be "Server refused our
3475 * key" (or no message at all if the key
3476 * came from Pageant)
3478 * - if we'd just tried anything else, the
3479 * message really should be "Access denied".
3481 * Additionally, if we'd just tried password
3482 * authentication, we should break out of this
3483 * whole loop so as to go back to the username
3486 if (type == AUTH_TYPE_NONE) {
3488 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3489 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3490 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3491 c_write_str("Server refused our key\r\n");
3492 logevent("Server refused public key");
3494 c_write_str("Access denied\r\n");
3495 logevent("Access denied");
3496 if (type == AUTH_TYPE_PASSWORD) {
3502 c_write_str("Further authentication required\r\n");
3503 logevent("Further authentication required");
3507 in_commasep_string("publickey", methods, methlen);
3509 in_commasep_string("password", methods, methlen);
3514 if (!method && can_pubkey && agent_exists() && !tried_agent) {
3516 * Attempt public-key authentication using Pageant.
3518 static unsigned char request[5], *response, *p;
3519 static int responselen;
3520 static int i, nkeys;
3521 static int authed = FALSE;
3526 logevent("Pageant is running. Requesting keys.");
3528 /* Request the keys held by the agent. */
3529 PUT_32BIT(request, 1);
3530 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3531 agent_query(request, 5, &r, &responselen);
3532 response = (unsigned char *) r;
3533 if (response && responselen >= 5 &&
3534 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3536 nkeys = GET_32BIT(p);
3540 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3543 for (i = 0; i < nkeys; i++) {
3544 static char *pkblob, *alg, *commentp;
3545 static int pklen, alglen, commentlen;
3546 static int siglen, retlen, len;
3547 static char *q, *agentreq, *ret;
3552 sprintf(buf, "Trying Pageant key #%d", i);
3555 pklen = GET_32BIT(p);
3559 alglen = GET_32BIT(pkblob);
3561 commentlen = GET_32BIT(p);
3565 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3566 ssh2_pkt_addstring(username);
3567 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3568 ssh2_pkt_addstring("publickey"); /* method */
3569 ssh2_pkt_addbool(FALSE); /* no signature included */
3570 ssh2_pkt_addstring_start();
3571 ssh2_pkt_addstring_data(alg, alglen);
3572 ssh2_pkt_addstring_start();
3573 ssh2_pkt_addstring_data(pkblob, pklen);
3576 crWaitUntilV(ispkt);
3577 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3578 logevent("Key refused");
3582 if (flags & FLAG_VERBOSE) {
3584 ("Authenticating with public key \"");
3585 c_write(commentp, commentlen);
3586 c_write_str("\" from agent\r\n");
3590 * Server is willing to accept the key.
3591 * Construct a SIGN_REQUEST.
3593 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3594 ssh2_pkt_addstring(username);
3595 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3596 ssh2_pkt_addstring("publickey"); /* method */
3597 ssh2_pkt_addbool(TRUE);
3598 ssh2_pkt_addstring_start();
3599 ssh2_pkt_addstring_data(alg, alglen);
3600 ssh2_pkt_addstring_start();
3601 ssh2_pkt_addstring_data(pkblob, pklen);
3603 siglen = pktout.length - 5 + 4 + 20;
3604 len = 1; /* message type */
3605 len += 4 + pklen; /* key blob */
3606 len += 4 + siglen; /* data to sign */
3607 len += 4; /* flags */
3608 agentreq = smalloc(4 + len);
3609 PUT_32BIT(agentreq, len);
3611 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3612 PUT_32BIT(q, pklen);
3614 memcpy(q, pkblob, pklen);
3616 PUT_32BIT(q, siglen);
3618 /* Now the data to be signed... */
3621 memcpy(q, ssh2_session_id, 20);
3623 memcpy(q, pktout.data + 5, pktout.length - 5);
3624 q += pktout.length - 5;
3625 /* And finally the (zero) flags word. */
3627 agent_query(agentreq, len + 4, &vret, &retlen);
3631 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3632 logevent("Sending Pageant's response");
3633 ssh2_pkt_addstring_start();
3634 ssh2_pkt_addstring_data(ret + 9,
3642 ("Pageant failed to answer challenge");
3652 if (!method && can_pubkey && *cfg.keyfile
3653 && !tried_pubkey_config) {
3654 unsigned char *pub_blob;
3655 char *algorithm, *comment;
3658 tried_pubkey_config = TRUE;
3661 * Try the public key supplied in the configuration.
3663 * First, offer the public blob to see if the server is
3664 * willing to accept it.
3666 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3669 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3670 ssh2_pkt_addstring(username);
3671 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3672 ssh2_pkt_addstring("publickey"); /* method */
3673 ssh2_pkt_addbool(FALSE); /* no signature included */
3674 ssh2_pkt_addstring(algorithm);
3675 ssh2_pkt_addstring_start();
3676 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3678 logevent("Offered public key"); /* FIXME */
3680 crWaitUntilV(ispkt);
3681 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3683 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3684 continue; /* key refused; give up on it */
3687 logevent("Offer of public key accepted");
3689 * Actually attempt a serious authentication using
3692 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3694 "Passphrase for key \"%.100s\": ",
3700 c_write_str("Authenticating with public key \"");
3701 c_write_str(comment);
3702 c_write_str("\"\r\n");
3703 method = AUTH_PUBLICKEY_FILE;
3707 if (!method && can_passwd) {
3708 method = AUTH_PASSWORD;
3709 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
3716 if (!ssh_get_line(pwprompt, password,
3717 sizeof(password), TRUE)) {
3719 * get_line failed to get a password (for
3720 * example because one was supplied on the
3721 * command line which has already failed to
3724 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3725 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3727 ("No more passwords available to try");
3728 ssh2_pkt_addstring("en"); /* language tag */
3730 connection_fatal("Unable to authenticate");
3731 ssh_state = SSH_STATE_CLOSED;
3738 c_write_str(pwprompt);
3743 crWaitUntilV(!ispkt);
3745 switch (c = *in++) {
3766 if (pos < sizeof(password)-1)
3767 password[pos++] = c;
3771 c_write_str("\r\n");
3775 if (method == AUTH_PUBLICKEY_FILE) {
3777 * We have our passphrase. Now try the actual authentication.
3779 struct ssh2_userkey *key;
3781 key = ssh2_load_userkey(cfg.keyfile, password);
3782 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3783 if (key == SSH2_WRONG_PASSPHRASE) {
3784 c_write_str("Wrong passphrase\r\n");
3785 tried_pubkey_config = FALSE;
3787 c_write_str("Unable to load private key\r\n");
3788 tried_pubkey_config = TRUE;
3790 /* Send a spurious AUTH_NONE to return to the top. */
3791 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3792 ssh2_pkt_addstring(username);
3793 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3794 ssh2_pkt_addstring("none"); /* method */
3796 type = AUTH_TYPE_NONE;
3798 unsigned char *blob, *sigdata;
3799 int blob_len, sigdata_len;
3802 * We have loaded the private key and the server
3803 * has announced that it's willing to accept it.
3804 * Hallelujah. Generate a signature and send it.
3806 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3807 ssh2_pkt_addstring(username);
3808 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3809 ssh2_pkt_addstring("publickey"); /* method */
3810 ssh2_pkt_addbool(TRUE);
3811 ssh2_pkt_addstring(key->alg->name);
3812 blob = key->alg->public_blob(key->data, &blob_len);
3813 ssh2_pkt_addstring_start();
3814 ssh2_pkt_addstring_data(blob, blob_len);
3818 * The data to be signed is:
3822 * followed by everything so far placed in the
3825 sigdata_len = pktout.length - 5 + 4 + 20;
3826 sigdata = smalloc(sigdata_len);
3827 PUT_32BIT(sigdata, 20);
3828 memcpy(sigdata + 4, ssh2_session_id, 20);
3829 memcpy(sigdata + 24, pktout.data + 5,
3832 key->alg->sign(key->data, sigdata, sigdata_len,
3834 ssh2_pkt_addstring_start();
3835 ssh2_pkt_addstring_data(blob, blob_len);
3840 type = AUTH_TYPE_PUBLICKEY;
3842 } else if (method == AUTH_PASSWORD) {
3844 * We send the password packet lumped tightly together with
3845 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3846 * string long enough to make the total length of the two
3847 * packets constant. This should ensure that a passive
3848 * listener doing traffic analyis can't work out the length
3851 * For this to work, we need an assumption about the
3852 * maximum length of the password packet. I think 256 is
3853 * pretty conservative. Anyone using a password longer than
3854 * that probably doesn't have much to worry about from
3855 * people who find out how long their password is!
3857 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3858 ssh2_pkt_addstring(username);
3859 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3860 ssh2_pkt_addstring("password");
3861 ssh2_pkt_addbool(FALSE);
3862 ssh2_pkt_addstring(password);
3865 * We'll include a string that's an exact multiple of the
3866 * cipher block size. If the cipher is NULL for some
3867 * reason, we don't do this trick at all because we gain
3873 stringlen = (256 - deferred_len);
3874 stringlen += cscipher->blksize - 1;
3875 stringlen -= (stringlen % cscipher->blksize);
3878 * Temporarily disable actual compression,
3879 * so we can guarantee to get this string
3880 * exactly the length we want it. The
3881 * compression-disabling routine should
3882 * return an integer indicating how many
3883 * bytes we should adjust our string length
3886 stringlen -= cscomp->disable_compression();
3888 ssh2_pkt_init(SSH2_MSG_IGNORE);
3889 ssh2_pkt_addstring_start();
3890 for (i = 0; i < stringlen; i++) {
3891 char c = (char) random_byte();
3892 ssh2_pkt_addstring_data(&c, 1);
3896 ssh_pkt_defersend();
3897 logevent("Sent password");
3898 type = AUTH_TYPE_PASSWORD;
3901 ("No supported authentication methods left to try!\r\n");
3903 ("No supported authentications offered. Disconnecting");
3904 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3905 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3907 ("No supported authentication methods available");
3908 ssh2_pkt_addstring("en"); /* language tag */
3910 ssh_state = SSH_STATE_CLOSED;
3914 } while (!we_are_in);
3917 * Now we're authenticated for the connection protocol. The
3918 * connection protocol will automatically have started at this
3919 * point; there's no need to send SERVICE_REQUEST.
3923 * So now create a channel with a session in it.
3925 ssh_channels = newtree234(ssh_channelcmp);
3926 mainchan = smalloc(sizeof(struct ssh_channel));
3927 mainchan->localid = alloc_channel_id();
3928 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3929 ssh2_pkt_addstring("session");
3930 ssh2_pkt_adduint32(mainchan->localid);
3931 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3932 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3934 crWaitUntilV(ispkt);
3935 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
3936 bombout(("Server refused to open a session"));
3938 /* FIXME: error data comes back in FAILURE packet */
3940 if (ssh2_pkt_getuint32() != mainchan->localid) {
3941 bombout(("Server's channel confirmation cited wrong channel"));
3944 mainchan->remoteid = ssh2_pkt_getuint32();
3945 mainchan->type = CHAN_MAINSESSION;
3946 mainchan->closes = 0;
3947 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3948 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3949 mainchan->v2.outbuffer = NULL;
3950 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3951 add234(ssh_channels, mainchan);
3952 logevent("Opened channel for session");
3955 * Potentially enable X11 forwarding.
3957 if (cfg.x11_forward) {
3958 char proto[20], data[64];
3959 logevent("Requesting X11 forwarding");
3960 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3961 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3962 ssh2_pkt_adduint32(mainchan->remoteid);
3963 ssh2_pkt_addstring("x11-req");
3964 ssh2_pkt_addbool(1); /* want reply */
3965 ssh2_pkt_addbool(0); /* many connections */
3966 ssh2_pkt_addstring(proto);
3967 ssh2_pkt_addstring(data);
3968 ssh2_pkt_adduint32(0); /* screen number */
3972 crWaitUntilV(ispkt);
3973 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3974 unsigned i = ssh2_pkt_getuint32();
3975 struct ssh_channel *c;
3976 c = find234(ssh_channels, &i, ssh_channelfind);
3978 continue; /* nonexistent channel */
3979 c->v2.remwindow += ssh2_pkt_getuint32();
3981 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3983 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3984 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3985 bombout(("Server got confused by X11 forwarding request"));
3988 logevent("X11 forwarding refused");
3990 logevent("X11 forwarding enabled");
3991 ssh_X11_fwd_enabled = TRUE;
3996 * Potentially enable agent forwarding.
3998 if (cfg.agentfwd && agent_exists()) {
3999 logevent("Requesting OpenSSH-style agent forwarding");
4000 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4001 ssh2_pkt_adduint32(mainchan->remoteid);
4002 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4003 ssh2_pkt_addbool(1); /* want reply */
4007 crWaitUntilV(ispkt);
4008 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4009 unsigned i = ssh2_pkt_getuint32();
4010 struct ssh_channel *c;
4011 c = find234(ssh_channels, &i, ssh_channelfind);
4013 continue; /* nonexistent channel */
4014 c->v2.remwindow += ssh2_pkt_getuint32();
4016 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4018 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4019 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4021 ("Server got confused by agent forwarding request"));
4024 logevent("Agent forwarding refused");
4026 logevent("Agent forwarding enabled");
4027 ssh_agentfwd_enabled = TRUE;
4032 * Now allocate a pty for the session.
4035 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4036 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4037 ssh2_pkt_addstring("pty-req");
4038 ssh2_pkt_addbool(1); /* want reply */
4039 ssh2_pkt_addstring(cfg.termtype);
4040 ssh2_pkt_adduint32(cols);
4041 ssh2_pkt_adduint32(rows);
4042 ssh2_pkt_adduint32(0); /* pixel width */
4043 ssh2_pkt_adduint32(0); /* pixel height */
4044 ssh2_pkt_addstring_start();
4045 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4047 ssh_state = SSH_STATE_INTERMED;
4050 crWaitUntilV(ispkt);
4051 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4052 unsigned i = ssh2_pkt_getuint32();
4053 struct ssh_channel *c;
4054 c = find234(ssh_channels, &i, ssh_channelfind);
4056 continue; /* nonexistent channel */
4057 c->v2.remwindow += ssh2_pkt_getuint32();
4059 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4061 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4062 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4063 bombout(("Server got confused by pty request"));
4066 c_write_str("Server refused to allocate pty\r\n");
4067 ssh_editing = ssh_echoing = 1;
4069 logevent("Allocated pty");
4072 ssh_editing = ssh_echoing = 1;
4076 * Start a shell or a remote command.
4078 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4079 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4080 if (cfg.ssh_subsys) {
4081 ssh2_pkt_addstring("subsystem");
4082 ssh2_pkt_addbool(1); /* want reply */
4083 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
4084 } else if (*cfg.remote_cmd_ptr) {
4085 ssh2_pkt_addstring("exec");
4086 ssh2_pkt_addbool(1); /* want reply */
4087 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
4089 ssh2_pkt_addstring("shell");
4090 ssh2_pkt_addbool(1); /* want reply */
4094 crWaitUntilV(ispkt);
4095 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4096 unsigned i = ssh2_pkt_getuint32();
4097 struct ssh_channel *c;
4098 c = find234(ssh_channels, &i, ssh_channelfind);
4100 continue; /* nonexistent channel */
4101 c->v2.remwindow += ssh2_pkt_getuint32();
4103 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4104 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4105 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4106 bombout(("Server got confused by shell/command request"));
4109 bombout(("Server refused to start a shell/command"));
4112 logevent("Started a shell/command");
4115 ssh_state = SSH_STATE_SESSION;
4119 ssh_special(TS_EOF);
4124 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
4127 static int try_send;
4131 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
4132 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4135 unsigned i = ssh2_pkt_getuint32();
4136 struct ssh_channel *c;
4137 c = find234(ssh_channels, &i, ssh_channelfind);
4139 continue; /* nonexistent channel */
4140 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4141 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4142 continue; /* extended but not stderr */
4143 ssh2_pkt_getstring(&data, &length);
4146 case CHAN_MAINSESSION:
4147 from_backend(pktin.type ==
4148 SSH2_MSG_CHANNEL_EXTENDED_DATA, data,
4152 x11_send(c->u.x11.s, data, length);
4155 pfd_send(c->u.pfd.s, data, length);
4158 while (length > 0) {
4159 if (c->u.a.lensofar < 4) {
4160 int l = min(4 - c->u.a.lensofar, length);
4161 memcpy(c->u.a.msglen + c->u.a.lensofar,
4165 c->u.a.lensofar += l;
4167 if (c->u.a.lensofar == 4) {
4169 4 + GET_32BIT(c->u.a.msglen);
4170 c->u.a.message = smalloc(c->u.a.totallen);
4171 memcpy(c->u.a.message, c->u.a.msglen, 4);
4173 if (c->u.a.lensofar >= 4 && length > 0) {
4175 min(c->u.a.totallen - c->u.a.lensofar,
4177 memcpy(c->u.a.message + c->u.a.lensofar,
4181 c->u.a.lensofar += l;
4183 if (c->u.a.lensofar == c->u.a.totallen) {
4184 void *reply, *sentreply;
4186 agent_query(c->u.a.message,
4187 c->u.a.totallen, &reply,
4192 /* Fake SSH_AGENT_FAILURE. */
4193 sentreply = "\0\0\0\1\5";
4196 ssh2_add_channel_data(c, sentreply,
4201 sfree(c->u.a.message);
4202 c->u.a.lensofar = 0;
4208 * Enlarge the window again at the remote
4209 * side, just in case it ever runs down and
4210 * they fail to send us any more data.
4212 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4213 ssh2_pkt_adduint32(c->remoteid);
4214 ssh2_pkt_adduint32(length);
4217 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4218 ssh_state = SSH_STATE_CLOSED;
4219 logevent("Received disconnect message");
4221 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
4222 continue; /* exit status et al; ignore (FIXME?) */
4223 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4224 unsigned i = ssh2_pkt_getuint32();
4225 struct ssh_channel *c;
4227 c = find234(ssh_channels, &i, ssh_channelfind);
4229 continue; /* nonexistent channel */
4231 if (c->type == CHAN_X11) {
4233 * Remote EOF on an X11 channel means we should
4234 * wrap up and close the channel ourselves.
4236 x11_close(c->u.x11.s);
4238 } else if (c->type == CHAN_AGENT) {
4240 } else if (c->type == CHAN_SOCKDATA) {
4241 pfd_close(c->u.pfd.s);
4244 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4245 unsigned i = ssh2_pkt_getuint32();
4246 struct ssh_channel *c;
4248 c = find234(ssh_channels, &i, ssh_channelfind);
4250 continue; /* nonexistent channel */
4251 if (c->closes == 0) {
4252 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4253 ssh2_pkt_adduint32(c->remoteid);
4256 /* Do pre-close processing on the channel. */
4258 case CHAN_MAINSESSION:
4259 break; /* nothing to see here, move along */
4267 del234(ssh_channels, c);
4268 sfree(c->v2.outbuffer);
4272 * See if that was the last channel left open.
4274 if (count234(ssh_channels) == 0) {
4275 logevent("All channels closed. Disconnecting");
4276 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4277 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4278 ssh2_pkt_addstring("All open channels closed");
4279 ssh2_pkt_addstring("en"); /* language tag */
4281 ssh_state = SSH_STATE_CLOSED;
4284 continue; /* remote sends close; ignore (FIXME) */
4285 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4286 unsigned i = ssh2_pkt_getuint32();
4287 struct ssh_channel *c;
4288 c = find234(ssh_channels, &i, ssh_channelfind);
4290 continue; /* nonexistent channel */
4291 c->v2.remwindow += ssh2_pkt_getuint32();
4293 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
4297 struct ssh_channel *c;
4298 ssh2_pkt_getstring(&type, &typelen);
4299 c = smalloc(sizeof(struct ssh_channel));
4301 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4302 if (!ssh_X11_fwd_enabled)
4303 error = "X11 forwarding is not enabled";
4304 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4306 error = "Unable to open an X11 connection";
4310 } else if (typelen == 22 &&
4311 !memcmp(type, "auth-agent@openssh.com", 3)) {
4312 if (!ssh_agentfwd_enabled)
4313 error = "Agent forwarding is not enabled";
4315 c->type = CHAN_AGENT; /* identify channel type */
4316 c->u.a.lensofar = 0;
4319 error = "Unsupported channel type requested";
4322 c->remoteid = ssh2_pkt_getuint32();
4324 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4325 ssh2_pkt_adduint32(c->remoteid);
4326 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4327 ssh2_pkt_addstring(error);
4328 ssh2_pkt_addstring("en"); /* language tag */
4332 c->localid = alloc_channel_id();
4334 c->v2.remwindow = ssh2_pkt_getuint32();
4335 c->v2.remmaxpkt = ssh2_pkt_getuint32();
4336 c->v2.outbuffer = NULL;
4337 c->v2.outbuflen = c->v2.outbufsize = 0;
4338 add234(ssh_channels, c);
4339 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4340 ssh2_pkt_adduint32(c->remoteid);
4341 ssh2_pkt_adduint32(c->localid);
4342 ssh2_pkt_adduint32(0x8000UL); /* our window size */
4343 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4347 bombout(("Strange packet received: type %d", pktin.type));
4352 * We have spare data. Add it to the channel buffer.
4354 ssh2_add_channel_data(mainchan, in, inlen);
4359 struct ssh_channel *c;
4361 * Try to send data on all channels if we can.
4363 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
4372 * Handle the top-level SSH2 protocol.
4374 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4376 if (do_ssh2_transport(in, inlen, ispkt) == 0)
4378 do_ssh2_authconn(in, inlen, ispkt);
4382 * Called to set up the connection.
4384 * Returns an error message, or NULL on success.
4386 static char *ssh_init(char *host, int port, char **realhost)
4391 if (crypto_startup() == 0)
4392 return "Microsoft high encryption pack not installed!";
4399 p = connect_to_host(host, port, realhost);
4407 * Called to send data down the Telnet connection.
4409 static void ssh_send(char *buf, int len)
4411 if (s == NULL || ssh_protocol == NULL)
4414 ssh_protocol(buf, len, 0);
4418 * Called to set the size of the window from SSH's POV.
4420 static void ssh_size(void)
4422 switch (ssh_state) {
4423 case SSH_STATE_BEFORE_SIZE:
4424 case SSH_STATE_PREPACKET:
4425 case SSH_STATE_CLOSED:
4426 break; /* do nothing */
4427 case SSH_STATE_INTERMED:
4428 size_needed = TRUE; /* buffer for later */
4430 case SSH_STATE_SESSION:
4432 if (ssh_version == 1) {
4433 send_packet(SSH1_CMSG_WINDOW_SIZE,
4434 PKT_INT, rows, PKT_INT, cols,
4435 PKT_INT, 0, PKT_INT, 0, PKT_END);
4437 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4438 ssh2_pkt_adduint32(mainchan->remoteid);
4439 ssh2_pkt_addstring("window-change");
4440 ssh2_pkt_addbool(0);
4441 ssh2_pkt_adduint32(cols);
4442 ssh2_pkt_adduint32(rows);
4443 ssh2_pkt_adduint32(0);
4444 ssh2_pkt_adduint32(0);
4453 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4454 * can send an EOF and collect resulting output (e.g. `plink
4457 static void ssh_special(Telnet_Special code)
4459 if (code == TS_EOF) {
4460 if (ssh_state != SSH_STATE_SESSION) {
4462 * Buffer the EOF in case we are pre-SESSION, so we can
4463 * send it as soon as we reach SESSION.
4469 if (ssh_version == 1) {
4470 send_packet(SSH1_CMSG_EOF, PKT_END);
4472 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4473 ssh2_pkt_adduint32(mainchan->remoteid);
4476 logevent("Sent EOF message");
4477 } else if (code == TS_PING) {
4478 if (ssh_state == SSH_STATE_CLOSED
4479 || ssh_state == SSH_STATE_PREPACKET) return;
4480 if (ssh_version == 1) {
4481 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
4483 ssh2_pkt_init(SSH2_MSG_IGNORE);
4484 ssh2_pkt_addstring_start();
4492 void *new_sock_channel(Socket s)
4494 struct ssh_channel *c;
4495 c = smalloc(sizeof(struct ssh_channel));
4498 c->remoteid = GET_32BIT(pktin.body);
4499 c->localid = alloc_channel_id();
4501 c->type = CHAN_SOCKDATA; /* identify channel type */
4503 add234(ssh_channels, c);
4508 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
4510 struct ssh_channel *c = (struct ssh_channel *)channel;
4513 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
4516 send_packet(SSH1_MSG_PORT_OPEN,
4517 PKT_INT, c->localid,
4525 static Socket ssh_socket(void)
4530 static int ssh_sendok(void)
4535 static int ssh_ldisc(int option)
4537 if (option == LD_ECHO)
4539 if (option == LD_EDIT)
4544 Backend ssh_backend = {