18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 fprintf(stderr, "%s\n", s); }
22 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, sk_close(s), \
23 s = NULL, connection_fatal msg )
25 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
26 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
27 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
28 #define SSH1_CMSG_USER 4 /* 0x4 */
29 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
30 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
31 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
32 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
33 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
34 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
35 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
36 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
37 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
38 #define SSH1_SMSG_FAILURE 15 /* 0xf */
39 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
40 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
41 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
42 #define SSH1_CMSG_EOF 19 /* 0x13 */
43 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
44 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
45 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
46 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
47 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
48 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
49 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
50 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
51 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
52 #define SSH1_MSG_IGNORE 32 /* 0x20 */
53 #define SSH1_MSG_DEBUG 36 /* 0x24 */
54 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
55 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
56 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
57 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
58 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
59 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
60 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
62 #define SSH1_AUTH_TIS 5 /* 0x5 */
63 #define SSH1_AUTH_CCARD 16 /* 0x10 */
65 #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
66 #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
67 #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
68 #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
69 #define SSH_AGENT_FAILURE 5 /* 0x5 */
70 #define SSH_AGENT_SUCCESS 6 /* 0x6 */
71 #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
72 #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
74 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
75 #define SSH2_MSG_IGNORE 2 /* 0x2 */
76 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
77 #define SSH2_MSG_DEBUG 4 /* 0x4 */
78 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
79 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
80 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
81 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
82 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
83 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
84 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
85 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
86 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
87 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
88 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
89 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
90 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
91 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
92 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
93 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
94 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
95 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
96 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
97 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
98 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
99 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
100 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
101 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
102 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
103 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
105 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
106 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
107 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
108 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
109 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
110 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
111 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
112 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
113 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
114 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
115 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
117 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
118 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
119 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
120 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
122 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
124 #define GET_32BIT(cp) \
125 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
126 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
127 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
128 ((unsigned long)(unsigned char)(cp)[3]))
130 #define PUT_32BIT(cp, value) { \
131 (cp)[0] = (unsigned char)((value) >> 24); \
132 (cp)[1] = (unsigned char)((value) >> 16); \
133 (cp)[2] = (unsigned char)((value) >> 8); \
134 (cp)[3] = (unsigned char)(value); }
136 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
138 /* Coroutine mechanics for the sillier bits of the code */
139 #define crBegin1 static int crLine = 0;
140 #define crBegin2 switch(crLine) { case 0:;
141 #define crBegin crBegin1; crBegin2;
142 #define crFinish(z) } crLine = 0; return (z)
143 #define crFinishV } crLine = 0; return
144 #define crReturn(z) \
146 crLine=__LINE__; return (z); case __LINE__:;\
150 crLine=__LINE__; return; case __LINE__:;\
152 #define crStop(z) do{ crLine = 0; return (z); }while(0)
153 #define crStopV do{ crLine = 0; return; }while(0)
154 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
155 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
157 extern const struct ssh_cipher ssh_3des;
158 extern const struct ssh_cipher ssh_3des_ssh2;
159 extern const struct ssh_cipher ssh_des;
160 extern const struct ssh_cipher ssh_blowfish_ssh1;
161 extern const struct ssh_cipher ssh_blowfish_ssh2;
164 * Ciphers for SSH2. We miss out single-DES because it isn't
165 * supported; also 3DES and Blowfish are both done differently from
166 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
167 * endianness and different-sized keys.)
169 const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
171 extern const struct ssh_kex ssh_diffiehellman;
172 const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
174 extern const struct ssh_signkey ssh_dss;
175 const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss };
177 extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
179 static void nullmac_key(unsigned char *key) { }
180 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
181 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
182 const static struct ssh_mac ssh_mac_none = {
183 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
185 const static struct ssh_mac *macs[] = {
186 &ssh_sha1, &ssh_md5, &ssh_mac_none };
187 const static struct ssh_mac *buggymacs[] = {
188 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
190 static void ssh_comp_none_init(void) { }
191 static int ssh_comp_none_block(unsigned char *block, int len,
192 unsigned char **outblock, int *outlen) {
195 const static struct ssh_compress ssh_comp_none = {
197 ssh_comp_none_init, ssh_comp_none_block,
198 ssh_comp_none_init, ssh_comp_none_block
200 extern const struct ssh_compress ssh_zlib;
201 const static struct ssh_compress *compressions[] = {
202 &ssh_zlib, &ssh_comp_none };
205 * 2-3-4 tree storing channels.
208 unsigned remoteid, localid;
212 struct ssh_agent_channel {
213 unsigned char *message;
214 unsigned char msglen[4];
215 int lensofar, totallen;
217 struct ssh2_data_channel {
218 unsigned char *outbuffer;
219 unsigned outbuflen, outbufsize;
220 unsigned remwindow, remmaxpkt;
234 static SHA_State exhash, exhashbase;
236 static Socket s = NULL;
238 static unsigned char session_key[32];
239 static int ssh1_compressing;
240 static int ssh_agentfwd_enabled;
241 static const struct ssh_cipher *cipher = NULL;
242 static const struct ssh_cipher *cscipher = NULL;
243 static const struct ssh_cipher *sccipher = NULL;
244 static const struct ssh_mac *csmac = NULL;
245 static const struct ssh_mac *scmac = NULL;
246 static const struct ssh_compress *cscomp = NULL;
247 static const struct ssh_compress *sccomp = NULL;
248 static const struct ssh_kex *kex = NULL;
249 static const struct ssh_signkey *hostkey = NULL;
250 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
252 static char *savedhost;
253 static int savedport;
254 static int ssh_send_ok;
256 static tree234 *ssh_channels; /* indexed by local id */
257 static struct ssh_channel *mainchan; /* primary session channel */
261 SSH_STATE_BEFORE_SIZE,
265 } ssh_state = SSH_STATE_PREPACKET;
267 static int size_needed = FALSE, eof_needed = FALSE;
269 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
270 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
272 static int ssh_version;
273 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
274 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
275 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
276 static void ssh_size(void);
277 static void ssh_special (Telnet_Special);
279 static int (*s_rdpkt)(unsigned char **data, int *datalen);
281 static struct rdpkt1_state_tag {
282 long len, pad, biglen, to_read;
283 unsigned long realcrc, gotcrc;
289 static struct rdpkt2_state_tag {
290 long len, pad, payload, packetlen, maclen;
293 unsigned long incoming_sequence;
296 static int ssh_channelcmp(void *av, void *bv) {
297 struct ssh_channel *a = (struct ssh_channel *)av;
298 struct ssh_channel *b = (struct ssh_channel *)bv;
299 if (a->localid < b->localid) return -1;
300 if (a->localid > b->localid) return +1;
303 static int ssh_channelfind(void *av, void *bv) {
304 unsigned *a = (unsigned *)av;
305 struct ssh_channel *b = (struct ssh_channel *)bv;
306 if (*a < b->localid) return -1;
307 if (*a > b->localid) return +1;
311 static void c_write (char *buf, int len) {
312 if ((flags & FLAG_STDERR)) {
314 for (i = 0; i < len; i++)
316 fputc(buf[i], stderr);
319 from_backend(1, buf, len);
323 * Collect incoming data in the incoming packet buffer.
324 * Decipher and verify the packet when it is completely read.
325 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
326 * Update the *data and *datalen variables.
327 * Return the additional nr of bytes needed, or 0 when
328 * a complete packet is available.
330 static int ssh1_rdpkt(unsigned char **data, int *datalen)
332 struct rdpkt1_state_tag *st = &rdpkt1_state;
341 for (st->i = st->len = 0; st->i < 4; st->i++) {
342 while ((*datalen) == 0)
344 st->len = (st->len << 8) + **data;
345 (*data)++, (*datalen)--;
349 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
350 st->len = 0x300; /* big enough to carry to end */
354 st->pad = 8 - (st->len % 8);
355 st->biglen = st->len + st->pad;
356 pktin.length = st->len - 5;
358 if (pktin.maxlen < st->biglen) {
359 pktin.maxlen = st->biglen;
360 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
361 srealloc(pktin.data, st->biglen+APIEXTRA));
363 fatalbox("Out of memory");
366 st->to_read = st->biglen;
368 while (st->to_read > 0) {
369 st->chunk = st->to_read;
370 while ((*datalen) == 0)
371 crReturn(st->to_read);
372 if (st->chunk > (*datalen))
373 st->chunk = (*datalen);
374 memcpy(st->p, *data, st->chunk);
376 *datalen -= st->chunk;
378 st->to_read -= st->chunk;
382 cipher->decrypt(pktin.data, st->biglen);
384 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
385 for (st->i = 0; st->i < st->biglen; st->i++)
386 debug((" %02x", (unsigned char)pktin.data[st->i]));
390 st->realcrc = crc32(pktin.data, st->biglen-4);
391 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
392 if (st->gotcrc != st->realcrc) {
393 bombout(("Incorrect CRC received on packet"));
397 pktin.body = pktin.data + st->pad + 1;
399 if (ssh1_compressing) {
400 unsigned char *decompblk;
404 debug(("Packet payload pre-decompression:\n"));
405 for (i = -1; i < pktin.length; i++)
406 debug((" %02x", (unsigned char)pktin.body[i]));
409 zlib_decompress_block(pktin.body-1, pktin.length+1,
410 &decompblk, &decomplen);
412 if (pktin.maxlen < st->pad + decomplen) {
413 pktin.maxlen = st->pad + decomplen;
414 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
415 pktin.body = pktin.data + st->pad + 1;
417 fatalbox("Out of memory");
420 memcpy(pktin.body-1, decompblk, decomplen);
422 pktin.length = decomplen-1;
424 debug(("Packet payload post-decompression:\n"));
425 for (i = -1; i < pktin.length; i++)
426 debug((" %02x", (unsigned char)pktin.body[i]));
431 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
432 pktin.type == SSH1_SMSG_STDERR_DATA ||
433 pktin.type == SSH1_MSG_DEBUG ||
434 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
435 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
436 long strlen = GET_32BIT(pktin.body);
437 if (strlen + 4 != pktin.length) {
438 bombout(("Received data packet with bogus string length"));
443 pktin.type = pktin.body[-1];
445 if (pktin.type == SSH1_MSG_DEBUG) {
446 /* log debug message */
448 int strlen = GET_32BIT(pktin.body);
449 strcpy(buf, "Remote: ");
450 if (strlen > 70) strlen = 70;
451 memcpy(buf+8, pktin.body+4, strlen);
452 buf[8+strlen] = '\0';
455 } else if (pktin.type == SSH1_MSG_IGNORE) {
463 static int ssh2_rdpkt(unsigned char **data, int *datalen)
465 struct rdpkt2_state_tag *st = &rdpkt2_state;
473 st->cipherblk = sccipher->blksize;
476 if (st->cipherblk < 8)
479 if (pktin.maxlen < st->cipherblk) {
480 pktin.maxlen = st->cipherblk;
481 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
482 srealloc(pktin.data, st->cipherblk+APIEXTRA));
484 fatalbox("Out of memory");
488 * Acquire and decrypt the first block of the packet. This will
489 * contain the length and padding details.
491 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
492 while ((*datalen) == 0)
493 crReturn(st->cipherblk-st->i);
494 pktin.data[st->i] = *(*data)++;
498 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
503 sccipher->decrypt(pktin.data, st->cipherblk);
506 * Now get the length and padding figures.
508 st->len = GET_32BIT(pktin.data);
509 st->pad = pktin.data[4];
512 * This enables us to deduce the payload length.
514 st->payload = st->len - st->pad - 1;
516 pktin.length = st->payload + 5;
519 * So now we can work out the total packet length.
521 st->packetlen = st->len + 4;
522 st->maclen = scmac ? scmac->len : 0;
525 * Adjust memory allocation if packet is too big.
527 if (pktin.maxlen < st->packetlen+st->maclen) {
528 pktin.maxlen = st->packetlen+st->maclen;
529 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
530 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
532 fatalbox("Out of memory");
536 * Read and decrypt the remainder of the packet.
538 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
539 while ((*datalen) == 0)
540 crReturn(st->packetlen + st->maclen - st->i);
541 pktin.data[st->i] = *(*data)++;
544 /* Decrypt everything _except_ the MAC. */
546 sccipher->decrypt(pktin.data + st->cipherblk,
547 st->packetlen - st->cipherblk);
550 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
551 for (st->i = 0; st->i < st->packetlen; st->i++)
552 debug((" %02x", (unsigned char)pktin.data[st->i]));
559 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
560 bombout(("Incorrect MAC received on packet"));
563 st->incoming_sequence++; /* whether or not we MACed */
566 * Decompress packet payload.
569 unsigned char *newpayload;
571 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
572 &newpayload, &newlen)) {
573 if (pktin.maxlen < newlen+5) {
574 pktin.maxlen = newlen+5;
575 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
576 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
578 fatalbox("Out of memory");
580 pktin.length = 5 + newlen;
581 memcpy(pktin.data+5, newpayload, newlen);
583 debug(("Post-decompression payload:\r\n"));
584 for (st->i = 0; st->i < newlen; st->i++)
585 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
594 pktin.type = pktin.data[5];
596 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
597 goto next_packet; /* FIXME: print DEBUG message */
602 static void ssh1_pktout_size(int len) {
605 len += 5; /* type and CRC */
609 pktout.length = len-5;
610 if (pktout.maxlen < biglen) {
611 pktout.maxlen = biglen;
613 /* Allocate enough buffer space for extra block
614 * for MS CryptEncrypt() */
615 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
616 srealloc(pktout.data, biglen+12));
618 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
619 srealloc(pktout.data, biglen+4));
622 fatalbox("Out of memory");
624 pktout.body = pktout.data+4+pad+1;
627 static void s_wrpkt_start(int type, int len) {
628 ssh1_pktout_size(len);
632 static void s_wrpkt(void) {
633 int pad, len, biglen, i;
636 pktout.body[-1] = pktout.type;
638 if (ssh1_compressing) {
639 unsigned char *compblk;
642 debug(("Packet payload pre-compression:\n"));
643 for (i = -1; i < pktout.length; i++)
644 debug((" %02x", (unsigned char)pktout.body[i]));
647 zlib_compress_block(pktout.body-1, pktout.length+1,
649 ssh1_pktout_size(complen-1);
650 memcpy(pktout.body-1, compblk, complen);
653 debug(("Packet payload post-compression:\n"));
654 for (i = -1; i < pktout.length; i++)
655 debug((" %02x", (unsigned char)pktout.body[i]));
660 len = pktout.length + 5; /* type and CRC */
664 for (i=0; i<pad; i++)
665 pktout.data[i+4] = random_byte();
666 crc = crc32(pktout.data+4, biglen-4);
667 PUT_32BIT(pktout.data+biglen, crc);
668 PUT_32BIT(pktout.data, len);
671 debug(("Sending packet len=%d\r\n", biglen+4));
672 for (i = 0; i < biglen+4; i++)
673 debug((" %02x", (unsigned char)pktout.data[i]));
677 cipher->encrypt(pktout.data+4, biglen);
679 sk_write(s, pktout.data, biglen+4);
683 * Construct a packet with the specified contents and
684 * send it to the server.
686 static void send_packet(int pkttype, ...)
689 unsigned char *p, *argp, argchar;
690 unsigned long argint;
691 int pktlen, argtype, arglen;
695 va_start(args, pkttype);
696 while ((argtype = va_arg(args, int)) != PKT_END) {
699 (void) va_arg(args, int);
703 (void) va_arg(args, char);
707 (void) va_arg(args, unsigned char *);
708 arglen = va_arg(args, int);
712 argp = va_arg(args, unsigned char *);
713 arglen = strlen(argp);
714 pktlen += 4 + arglen;
717 bn = va_arg(args, Bignum);
718 pktlen += ssh1_bignum_length(bn);
726 s_wrpkt_start(pkttype, pktlen);
729 va_start(args, pkttype);
730 while ((argtype = va_arg(args, int)) != PKT_END) {
733 argint = va_arg(args, int);
734 PUT_32BIT(p, argint);
738 argchar = va_arg(args, unsigned char);
743 argp = va_arg(args, unsigned char *);
744 arglen = va_arg(args, int);
745 memcpy(p, argp, arglen);
749 argp = va_arg(args, unsigned char *);
750 arglen = strlen(argp);
751 PUT_32BIT(p, arglen);
752 memcpy(p + 4, argp, arglen);
756 bn = va_arg(args, Bignum);
757 p += ssh1_write_bignum(p, bn);
766 static int ssh_versioncmp(char *a, char *b) {
768 unsigned long av, bv;
770 av = strtoul(a, &ae, 10);
771 bv = strtoul(b, &be, 10);
772 if (av != bv) return (av < bv ? -1 : +1);
773 if (*ae == '.') ae++;
774 if (*be == '.') be++;
775 av = strtoul(ae, &ae, 10);
776 bv = strtoul(be, &be, 10);
777 if (av != bv) return (av < bv ? -1 : +1);
783 * Utility routine for putting an SSH-protocol `string' into a SHA
787 static void sha_string(SHA_State *s, void *str, int len) {
788 unsigned char lenblk[4];
789 PUT_32BIT(lenblk, len);
790 SHA_Bytes(s, lenblk, 4);
791 SHA_Bytes(s, str, len);
795 * SSH2 packet construction functions.
797 static void ssh2_pkt_adddata(void *data, int len) {
798 pktout.length += len;
799 if (pktout.maxlen < pktout.length) {
800 pktout.maxlen = pktout.length + 256;
801 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
802 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
804 fatalbox("Out of memory");
806 memcpy(pktout.data+pktout.length-len, data, len);
808 static void ssh2_pkt_addbyte(unsigned char byte) {
809 ssh2_pkt_adddata(&byte, 1);
811 static void ssh2_pkt_init(int pkt_type) {
813 ssh2_pkt_addbyte((unsigned char)pkt_type);
815 static void ssh2_pkt_addbool(unsigned char value) {
816 ssh2_pkt_adddata(&value, 1);
818 static void ssh2_pkt_adduint32(unsigned long value) {
821 ssh2_pkt_adddata(x, 4);
823 static void ssh2_pkt_addstring_start(void) {
824 ssh2_pkt_adduint32(0);
825 pktout.savedpos = pktout.length;
827 static void ssh2_pkt_addstring_str(char *data) {
828 ssh2_pkt_adddata(data, strlen(data));
829 PUT_32BIT(pktout.data + pktout.savedpos - 4,
830 pktout.length - pktout.savedpos);
832 static void ssh2_pkt_addstring_data(char *data, int len) {
833 ssh2_pkt_adddata(data, len);
834 PUT_32BIT(pktout.data + pktout.savedpos - 4,
835 pktout.length - pktout.savedpos);
837 static void ssh2_pkt_addstring(char *data) {
838 ssh2_pkt_addstring_start();
839 ssh2_pkt_addstring_str(data);
841 static char *ssh2_mpint_fmt(Bignum b, int *len) {
844 p = smalloc(n * 2 + 1);
846 fatalbox("out of memory");
848 for (i = 0; i < n; i++) {
849 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
850 p[i*2+2] = (b[n-i] ) & 0xFF;
853 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
855 memmove(p, p+i, n*2+1-i);
859 static void ssh2_pkt_addmp(Bignum b) {
862 p = ssh2_mpint_fmt(b, &len);
863 ssh2_pkt_addstring_start();
864 ssh2_pkt_addstring_data(p, len);
867 static void ssh2_pkt_send(void) {
868 int cipherblk, maclen, padding, i;
869 static unsigned long outgoing_sequence = 0;
872 * Compress packet payload.
875 debug(("Pre-compression payload:\r\n"));
876 for (i = 5; i < pktout.length; i++)
877 debug((" %02x", (unsigned char)pktout.data[i]));
881 unsigned char *newpayload;
883 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
884 &newpayload, &newlen)) {
886 ssh2_pkt_adddata(newpayload, newlen);
892 * Add padding. At least four bytes, and must also bring total
893 * length (minus MAC) up to a multiple of the block size.
895 cipherblk = cipher ? cipher->blksize : 8; /* block size */
896 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
898 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
899 pktout.data[4] = padding;
900 for (i = 0; i < padding; i++)
901 pktout.data[pktout.length + i] = random_byte();
902 PUT_32BIT(pktout.data, pktout.length + padding - 4);
904 csmac->generate(pktout.data, pktout.length + padding,
906 outgoing_sequence++; /* whether or not we MACed */
909 debug(("Sending packet len=%d\r\n", pktout.length+padding));
910 for (i = 0; i < pktout.length+padding; i++)
911 debug((" %02x", (unsigned char)pktout.data[i]));
916 cscipher->encrypt(pktout.data, pktout.length + padding);
917 maclen = csmac ? csmac->len : 0;
919 sk_write(s, pktout.data, pktout.length + padding + maclen);
923 void bndebug(char *string, Bignum b) {
926 p = ssh2_mpint_fmt(b, &len);
927 debug(("%s", string));
928 for (i = 0; i < len; i++)
929 debug((" %02x", p[i]));
935 static void sha_mpint(SHA_State *s, Bignum b) {
938 p = ssh2_mpint_fmt(b, &len);
939 sha_string(s, p, len);
944 * SSH2 packet decode functions.
946 static unsigned long ssh2_pkt_getuint32(void) {
948 if (pktin.length - pktin.savedpos < 4)
949 return 0; /* arrgh, no way to decline (FIXME?) */
950 value = GET_32BIT(pktin.data+pktin.savedpos);
954 static void ssh2_pkt_getstring(char **p, int *length) {
956 if (pktin.length - pktin.savedpos < 4)
958 *length = GET_32BIT(pktin.data+pktin.savedpos);
960 if (pktin.length - pktin.savedpos < *length)
962 *p = pktin.data+pktin.savedpos;
963 pktin.savedpos += *length;
965 static Bignum ssh2_pkt_getmp(void) {
970 ssh2_pkt_getstring(&p, &length);
974 bombout(("internal error: Can't handle negative mpints"));
977 b = newbn((length+1)/2);
978 for (i = 0; i < length; i++) {
981 b[j/2+1] |= ((unsigned char)p[i]) << 8;
983 b[j/2+1] |= ((unsigned char)p[i]);
985 while (b[0] > 1 && b[b[0]] == 0) b[0]--;
989 static int do_ssh_init(unsigned char c) {
991 static char version[10];
992 static char vstring[80];
993 static char vlog[sizeof(vstring)+20];
998 /* Search for the string "SSH-" in the input. */
1001 static const int transS[] = { 1, 2, 2, 1 };
1002 static const int transH[] = { 0, 0, 3, 0 };
1003 static const int transminus[] = { 0, 0, 0, -1 };
1004 if (c == 'S') i = transS[i];
1005 else if (c == 'H') i = transH[i];
1006 else if (c == '-') i = transminus[i];
1010 crReturn(1); /* get another character */
1013 strcpy(vstring, "SSH-");
1017 crReturn(1); /* get another char */
1018 if (vsp < vstring+sizeof(vstring)-1)
1024 } else if (i < sizeof(version)-1)
1031 ssh_agentfwd_enabled = FALSE;
1032 rdpkt2_state.incoming_sequence = 0;
1035 sprintf(vlog, "Server version: %s", vstring);
1036 vlog[strcspn(vlog, "\r\n")] = '\0';
1040 * Server version "1.99" means we can choose whether we use v1
1041 * or v2 protocol. Choice is based on cfg.sshprot.
1043 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1045 * This is a v2 server. Begin v2 protocol.
1047 char *verstring = "SSH-2.0-PuTTY";
1048 SHA_Init(&exhashbase);
1050 * Hash our version string and their version string.
1052 sha_string(&exhashbase, verstring, strlen(verstring));
1053 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1054 sprintf(vstring, "%s\n", verstring);
1055 sprintf(vlog, "We claim version: %s", verstring);
1057 logevent("Using SSH protocol version 2");
1058 sk_write(s, vstring, strlen(vstring));
1059 ssh_protocol = ssh2_protocol;
1061 s_rdpkt = ssh2_rdpkt;
1064 * This is a v1 server. Begin v1 protocol.
1066 sprintf(vstring, "SSH-%s-PuTTY\n",
1067 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1068 sprintf(vlog, "We claim version: %s", vstring);
1069 vlog[strcspn(vlog, "\r\n")] = '\0';
1071 logevent("Using SSH protocol version 1");
1072 sk_write(s, vstring, strlen(vstring));
1073 ssh_protocol = ssh1_protocol;
1075 s_rdpkt = ssh1_rdpkt;
1077 ssh_state = SSH_STATE_BEFORE_SIZE;
1082 static void ssh_gotdata(unsigned char *data, int datalen)
1087 * To begin with, feed the characters one by one to the
1088 * protocol initialisation / selection function do_ssh_init().
1089 * When that returns 0, we're done with the initial greeting
1090 * exchange and can move on to packet discipline.
1095 crReturnV; /* more data please */
1096 ret = do_ssh_init(*data);
1103 * We emerge from that loop when the initial negotiation is
1104 * over and we have selected an s_rdpkt function. Now pass
1105 * everything to s_rdpkt, and then pass the resulting packets
1106 * to the proper protocol handler.
1111 while (datalen > 0) {
1112 if ( s_rdpkt(&data, &datalen) == 0 ) {
1113 ssh_protocol(NULL, 0, 1);
1114 if (ssh_state == SSH_STATE_CLOSED) {
1124 static int ssh_receive(Socket skt, int urgent, char *data, int len) {
1126 /* Connection has closed. */
1127 ssh_state = SSH_STATE_CLOSED;
1132 ssh_gotdata (data, len);
1133 if (ssh_state == SSH_STATE_CLOSED) {
1144 * Connect to specified host and port.
1145 * Returns an error message, or NULL on success.
1146 * Also places the canonical host name into `realhost'.
1148 static char *connect_to_host(char *host, int port, char **realhost)
1157 savedhost = smalloc(1+strlen(host));
1159 fatalbox("Out of memory");
1160 strcpy(savedhost, host);
1163 port = 22; /* default ssh port */
1176 addr = sk_namelookup(host, realhost);
1177 if ( (err = sk_addr_error(addr)) )
1187 s = sk_new(addr, port, ssh_receive);
1188 if ( (err = sk_socket_error(s)) )
1192 sk_write(s, "connect ", 8);
1193 sk_write(s, FWhost, strlen(FWhost));
1196 sprintf(buf, " %d\n", FWport);
1197 sk_write(s, buf, strlen(buf));
1205 * Handle the key exchange and user authentication phases.
1207 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1210 unsigned char *rsabuf, *keystr1, *keystr2;
1211 unsigned char cookie[8];
1212 struct RSAKey servkey, hostkey;
1213 struct MD5Context md5c;
1214 static unsigned long supported_ciphers_mask, supported_auths_mask;
1215 static int tried_publickey;
1216 static unsigned char session_id[16];
1218 static char username[100];
1222 if (!ispkt) crWaitUntil(ispkt);
1224 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1225 bombout(("Public key packet not received"));
1229 logevent("Received public keys");
1231 memcpy(cookie, pktin.body, 8);
1233 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1234 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1237 * Log the host key fingerprint.
1241 logevent("Host key fingerprint is:");
1242 strcpy(logmsg, " ");
1243 hostkey.comment = NULL;
1244 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1249 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1250 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1253 MD5Update(&md5c, keystr2, hostkey.bytes);
1254 MD5Update(&md5c, keystr1, servkey.bytes);
1255 MD5Update(&md5c, pktin.body, 8);
1256 MD5Final(session_id, &md5c);
1258 for (i=0; i<32; i++)
1259 session_key[i] = random_byte();
1261 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1263 rsabuf = smalloc(len);
1265 fatalbox("Out of memory");
1268 * Verify the host key.
1272 * First format the key into a string.
1274 int len = rsastr_len(&hostkey);
1275 char fingerprint[100];
1276 char *keystr = smalloc(len);
1278 fatalbox("Out of memory");
1279 rsastr_fmt(keystr, &hostkey);
1280 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1281 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1285 for (i=0; i<32; i++) {
1286 rsabuf[i] = session_key[i];
1288 rsabuf[i] ^= session_id[i];
1291 if (hostkey.bytes > servkey.bytes) {
1292 rsaencrypt(rsabuf, 32, &servkey);
1293 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1295 rsaencrypt(rsabuf, 32, &hostkey);
1296 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1299 logevent("Encrypted session key");
1301 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
1302 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
1304 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1305 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1306 cipher_type = SSH_CIPHER_3DES;
1308 switch (cipher_type) {
1309 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1310 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1311 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1314 send_packet(SSH1_CMSG_SESSION_KEY,
1315 PKT_CHAR, cipher_type,
1316 PKT_DATA, cookie, 8,
1317 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1318 PKT_DATA, rsabuf, len,
1322 logevent("Trying to enable encryption...");
1326 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1327 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1329 cipher->sesskey(session_key);
1333 if (pktin.type != SSH1_SMSG_SUCCESS) {
1334 bombout(("Encryption not successfully enabled"));
1338 logevent("Successfully started encryption");
1344 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1345 c_write("login as: ", 10);
1348 crWaitUntil(!ispkt);
1349 while (inlen--) switch (c = *in++) {
1356 c_write("\b \b", 3);
1362 c_write("\b \b", 3);
1371 if (((c >= ' ' && c <= '~') ||
1372 ((unsigned char)c >= 160)) && pos < 40) {
1373 username[pos++] = c;
1380 username[strcspn(username, "\n\r")] = '\0';
1382 strncpy(username, cfg.username, 99);
1383 username[99] = '\0';
1386 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1388 char userlog[22+sizeof(username)];
1389 sprintf(userlog, "Sent username \"%s\"", username);
1391 if (flags & FLAG_INTERACTIVE &&
1392 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1393 strcat(userlog, "\r\n");
1394 c_write(userlog, strlen(userlog));
1401 tried_publickey = 0;
1403 while (pktin.type == SSH1_SMSG_FAILURE) {
1404 static char password[100];
1405 static char prompt[200];
1408 static int pwpkt_type;
1410 * Show password prompt, having first obtained it via a TIS
1411 * or CryptoCard exchange if we're doing TIS or CryptoCard
1414 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1415 if (agent_exists()) {
1417 * Attempt RSA authentication using Pageant.
1419 static unsigned char request[5], *response, *p;
1420 static int responselen;
1421 static int i, nkeys;
1422 static int authed = FALSE;
1425 logevent("Pageant is running. Requesting keys.");
1427 /* Request the keys held by the agent. */
1428 PUT_32BIT(request, 1);
1429 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1430 agent_query(request, 5, &r, &responselen);
1431 response = (unsigned char *)r;
1434 nkeys = GET_32BIT(p); p += 4;
1435 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1437 for (i = 0; i < nkeys; i++) {
1438 static struct RSAKey key;
1439 static Bignum challenge;
1440 static char *commentp;
1441 static int commentlen;
1443 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1446 p += ssh1_read_bignum(p, &key.exponent);
1447 p += ssh1_read_bignum(p, &key.modulus);
1448 commentlen = GET_32BIT(p); p += 4;
1449 commentp = p; p += commentlen;
1450 send_packet(SSH1_CMSG_AUTH_RSA,
1451 PKT_BIGNUM, key.modulus, PKT_END);
1453 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1454 logevent("Key refused");
1457 logevent("Received RSA challenge");
1458 ssh1_read_bignum(pktin.body, &challenge);
1460 char *agentreq, *q, *ret;
1462 len = 1 + 4; /* message type, bit count */
1463 len += ssh1_bignum_length(key.exponent);
1464 len += ssh1_bignum_length(key.modulus);
1465 len += ssh1_bignum_length(challenge);
1466 len += 16; /* session id */
1467 len += 4; /* response format */
1468 agentreq = smalloc(4 + len);
1469 PUT_32BIT(agentreq, len);
1471 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1472 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1474 q += ssh1_write_bignum(q, key.exponent);
1475 q += ssh1_write_bignum(q, key.modulus);
1476 q += ssh1_write_bignum(q, challenge);
1477 memcpy(q, session_id, 16); q += 16;
1478 PUT_32BIT(q, 1); /* response format */
1479 agent_query(agentreq, len+4, &ret, &retlen);
1482 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1483 logevent("Sending Pageant's response");
1484 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1485 PKT_DATA, ret+5, 16, PKT_END);
1488 if (pktin.type == SSH1_SMSG_SUCCESS) {
1489 logevent("Pageant's response accepted");
1490 if (flags & FLAG_VERBOSE) {
1491 c_write("Authenticated using RSA key \"",
1493 c_write(commentp, commentlen);
1494 c_write("\" from agent\r\n", 14);
1498 logevent("Pageant's response not accepted");
1500 logevent("Pageant failed to answer challenge");
1504 logevent("No reply received from Pageant");
1507 freebn(key.exponent);
1508 freebn(key.modulus);
1517 if (*cfg.keyfile && !tried_publickey)
1518 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1520 if (pktin.type == SSH1_SMSG_FAILURE &&
1522 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1523 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1524 logevent("Requested TIS authentication");
1525 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1527 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1528 logevent("TIS authentication declined");
1529 if (flags & FLAG_INTERACTIVE)
1530 c_write("TIS authentication refused.\r\n", 29);
1532 int challengelen = ((pktin.body[0] << 24) |
1533 (pktin.body[1] << 16) |
1534 (pktin.body[2] << 8) |
1536 logevent("Received TIS challenge");
1537 if (challengelen > sizeof(prompt)-1)
1538 challengelen = sizeof(prompt)-1; /* prevent overrun */
1539 memcpy(prompt, pktin.body+4, challengelen);
1540 prompt[challengelen] = '\0';
1543 if (pktin.type == SSH1_SMSG_FAILURE &&
1545 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1546 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1547 logevent("Requested CryptoCard authentication");
1548 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1550 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1551 logevent("CryptoCard authentication declined");
1552 c_write("CryptoCard authentication refused.\r\n", 29);
1554 int challengelen = ((pktin.body[0] << 24) |
1555 (pktin.body[1] << 16) |
1556 (pktin.body[2] << 8) |
1558 logevent("Received CryptoCard challenge");
1559 if (challengelen > sizeof(prompt)-1)
1560 challengelen = sizeof(prompt)-1; /* prevent overrun */
1561 memcpy(prompt, pktin.body+4, challengelen);
1562 strncpy(prompt + challengelen, "\r\nResponse : ",
1563 sizeof(prompt)-challengelen);
1564 prompt[sizeof(prompt)-1] = '\0';
1567 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1568 sprintf(prompt, "%.90s@%.90s's password: ",
1569 username, savedhost);
1571 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1572 char *comment = NULL;
1573 if (flags & FLAG_VERBOSE)
1574 c_write("Trying public key authentication.\r\n", 35);
1575 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1576 if (flags & FLAG_VERBOSE)
1577 c_write("No passphrase required.\r\n", 25);
1580 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1584 if (ssh_get_password) {
1585 if (!ssh_get_password(prompt, password, sizeof(password))) {
1587 * get_password failed to get a password (for
1588 * example because one was supplied on the command
1589 * line which has already failed to work).
1592 logevent("No more passwords to try");
1593 ssh_state = SSH_STATE_CLOSED;
1597 c_write(prompt, strlen(prompt));
1601 crWaitUntil(!ispkt);
1602 while (inlen--) switch (c = *in++) {
1619 if (((c >= ' ' && c <= '~') ||
1620 ((unsigned char)c >= 160)) && pos < sizeof(password))
1621 password[pos++] = c;
1629 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1631 * Try public key authentication with the specified
1634 static struct RSAKey pubkey;
1635 static Bignum challenge, response;
1637 static unsigned char buffer[32];
1639 tried_publickey = 1;
1640 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
1642 c_write("Couldn't load public key from ", 30);
1643 c_write(cfg.keyfile, strlen(cfg.keyfile));
1644 c_write(".\r\n", 3);
1645 continue; /* go and try password */
1648 c_write("Wrong passphrase.\r\n", 19);
1649 tried_publickey = 0;
1650 continue; /* try again */
1654 * Send a public key attempt.
1656 send_packet(SSH1_CMSG_AUTH_RSA,
1657 PKT_BIGNUM, pubkey.modulus, PKT_END);
1660 if (pktin.type == SSH1_SMSG_FAILURE) {
1661 c_write("Server refused our public key.\r\n", 32);
1662 continue; /* go and try password */
1664 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1665 bombout(("Bizarre response to offer of public key"));
1668 ssh1_read_bignum(pktin.body, &challenge);
1669 response = rsadecrypt(challenge, &pubkey);
1670 freebn(pubkey.private_exponent); /* burn the evidence */
1672 for (i = 0; i < 32; i += 2) {
1673 buffer[i] = response[16-i/2] >> 8;
1674 buffer[i+1] = response[16-i/2] & 0xFF;
1678 MD5Update(&md5c, buffer, 32);
1679 MD5Update(&md5c, session_id, 16);
1680 MD5Final(buffer, &md5c);
1682 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1683 PKT_DATA, buffer, 16, PKT_END);
1686 if (pktin.type == SSH1_SMSG_FAILURE) {
1687 if (flags & FLAG_VERBOSE)
1688 c_write("Failed to authenticate with our public key.\r\n",
1690 continue; /* go and try password */
1691 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1692 bombout(("Bizarre response to RSA authentication response"));
1696 break; /* we're through! */
1698 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1700 logevent("Sent password");
1701 memset(password, 0, strlen(password));
1703 if (pktin.type == SSH1_SMSG_FAILURE) {
1704 if (flags & FLAG_VERBOSE)
1705 c_write("Access denied\r\n", 15);
1706 logevent("Authentication refused");
1707 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1708 logevent("Received disconnect request");
1709 ssh_state = SSH_STATE_CLOSED;
1711 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1712 bombout(("Strange packet received, type %d", pktin.type));
1717 logevent("Authentication successful");
1722 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1727 while (!do_ssh1_login(in, inlen, ispkt)) {
1730 if (ssh_state == SSH_STATE_CLOSED)
1733 if (cfg.agentfwd && agent_exists()) {
1734 logevent("Requesting agent forwarding");
1735 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1736 do { crReturnV; } while (!ispkt);
1737 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1738 bombout(("Protocol confusion"));
1740 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1741 logevent("Agent forwarding refused");
1743 logevent("Agent forwarding enabled");
1744 ssh_agentfwd_enabled = TRUE;
1749 send_packet(SSH1_CMSG_REQUEST_PTY,
1750 PKT_STR, cfg.termtype,
1751 PKT_INT, rows, PKT_INT, cols,
1752 PKT_INT, 0, PKT_INT, 0,
1755 ssh_state = SSH_STATE_INTERMED;
1756 do { crReturnV; } while (!ispkt);
1757 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1758 bombout(("Protocol confusion"));
1760 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1761 c_write("Server refused to allocate pty\r\n", 32);
1763 logevent("Allocated pty");
1766 if (cfg.compression) {
1767 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1768 do { crReturnV; } while (!ispkt);
1769 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1770 bombout(("Protocol confusion"));
1772 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1773 c_write("Server refused to compress\r\n", 32);
1775 logevent("Started compression");
1776 ssh1_compressing = TRUE;
1777 zlib_compress_init();
1778 zlib_decompress_init();
1781 if (*cfg.remote_cmd)
1782 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1784 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1785 logevent("Started session");
1787 ssh_state = SSH_STATE_SESSION;
1791 ssh_special(TS_EOF);
1794 ssh_channels = newtree234(ssh_channelcmp);
1799 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1800 pktin.type == SSH1_SMSG_STDERR_DATA) {
1801 long len = GET_32BIT(pktin.body);
1802 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1804 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1805 ssh_state = SSH_STATE_CLOSED;
1806 logevent("Received disconnect request");
1808 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1809 /* Remote side is trying to open a channel to talk to our
1810 * agent. Give them back a local channel number. */
1812 struct ssh_channel *c;
1815 /* Refuse if agent forwarding is disabled. */
1816 if (!ssh_agentfwd_enabled) {
1817 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1818 PKT_INT, GET_32BIT(pktin.body),
1822 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1824 break; /* found a free number */
1827 c = smalloc(sizeof(struct ssh_channel));
1828 c->remoteid = GET_32BIT(pktin.body);
1831 c->type = SSH1_SMSG_AGENT_OPEN;/* identify channel type */
1832 c->u.a.lensofar = 0;
1833 add234(ssh_channels, c);
1834 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1835 PKT_INT, c->remoteid, PKT_INT, c->localid,
1838 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1839 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1840 /* Remote side closes a channel. */
1841 unsigned i = GET_32BIT(pktin.body);
1842 struct ssh_channel *c;
1843 c = find234(ssh_channels, &i, ssh_channelfind);
1846 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1847 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1848 c->closes |= closetype;
1849 if (c->closes == 3) {
1850 del234(ssh_channels, c);
1854 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1855 /* Data sent down one of our channels. */
1856 int i = GET_32BIT(pktin.body);
1857 int len = GET_32BIT(pktin.body+4);
1858 unsigned char *p = pktin.body+8;
1859 struct ssh_channel *c;
1860 c = find234(ssh_channels, &i, ssh_channelfind);
1863 case SSH1_SMSG_AGENT_OPEN:
1864 /* Data for an agent message. Buffer it. */
1866 if (c->u.a.lensofar < 4) {
1867 int l = min(4 - c->u.a.lensofar, len);
1868 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1869 p += l; len -= l; c->u.a.lensofar += l;
1871 if (c->u.a.lensofar == 4) {
1872 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1873 c->u.a.message = smalloc(c->u.a.totallen);
1874 memcpy(c->u.a.message, c->u.a.msglen, 4);
1876 if (c->u.a.lensofar >= 4 && len > 0) {
1877 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1878 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1879 p += l; len -= l; c->u.a.lensofar += l;
1881 if (c->u.a.lensofar == c->u.a.totallen) {
1882 void *reply, *sentreply;
1884 agent_query(c->u.a.message, c->u.a.totallen,
1889 /* Fake SSH_AGENT_FAILURE. */
1890 sentreply = "\0\0\0\1\5";
1893 send_packet(SSH1_MSG_CHANNEL_DATA,
1894 PKT_INT, c->remoteid,
1896 PKT_DATA, sentreply, replylen,
1900 sfree(c->u.a.message);
1901 c->u.a.lensofar = 0;
1907 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
1908 /* may be from EXEC_SHELL on some servers */
1909 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1910 /* may be from EXEC_SHELL on some servers
1911 * if no pty is available or in other odd cases. Ignore */
1912 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1913 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
1915 bombout(("Strange packet received: type %d", pktin.type));
1920 int len = min(inlen, 512);
1921 send_packet(SSH1_CMSG_STDIN_DATA,
1922 PKT_INT, len, PKT_DATA, in, len, PKT_END);
1933 * Utility routine for decoding comma-separated strings in KEXINIT.
1935 static int in_commasep_string(char *needle, char *haystack, int haylen) {
1936 int needlen = strlen(needle);
1939 * Is it at the start of the string?
1941 if (haylen >= needlen && /* haystack is long enough */
1942 !memcmp(needle, haystack, needlen) && /* initial match */
1943 (haylen == needlen || haystack[needlen] == ',')
1944 /* either , or EOS follows */
1948 * If not, search for the next comma and resume after that.
1949 * If no comma found, terminate.
1951 while (haylen > 0 && *haystack != ',')
1952 haylen--, haystack++;
1955 haylen--, haystack++; /* skip over comma itself */
1960 * SSH2 key creation method.
1962 static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1964 /* First 20 bytes. */
1967 SHA_Bytes(&s, H, 20);
1968 SHA_Bytes(&s, &chr, 1);
1969 SHA_Bytes(&s, H, 20);
1970 SHA_Final(&s, keyspace);
1971 /* Next 20 bytes. */
1974 SHA_Bytes(&s, H, 20);
1975 SHA_Bytes(&s, keyspace, 20);
1976 SHA_Final(&s, keyspace+20);
1980 * Handle the SSH2 transport layer.
1982 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
1986 static Bignum e, f, K;
1987 static const struct ssh_mac **maclist;
1989 static const struct ssh_cipher *cscipher_tobe = NULL;
1990 static const struct ssh_cipher *sccipher_tobe = NULL;
1991 static const struct ssh_mac *csmac_tobe = NULL;
1992 static const struct ssh_mac *scmac_tobe = NULL;
1993 static const struct ssh_compress *cscomp_tobe = NULL;
1994 static const struct ssh_compress *sccomp_tobe = NULL;
1995 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
1996 static int hostkeylen, siglen;
1997 static void *hkey; /* actual host key */
1998 static unsigned char exchange_hash[20];
1999 static unsigned char keyspace[40];
2000 static const struct ssh_cipher *preferred_cipher;
2001 static const struct ssh_compress *preferred_comp;
2002 static int first_kex;
2009 * Set up the preferred cipher and compression.
2011 if (cfg.cipher == CIPHER_BLOWFISH) {
2012 preferred_cipher = &ssh_blowfish_ssh2;
2013 } else if (cfg.cipher == CIPHER_DES) {
2014 logevent("Single DES not supported in SSH2; using 3DES");
2015 preferred_cipher = &ssh_3des_ssh2;
2016 } else if (cfg.cipher == CIPHER_3DES) {
2017 preferred_cipher = &ssh_3des_ssh2;
2019 /* Shouldn't happen, but we do want to initialise to _something_. */
2020 preferred_cipher = &ssh_3des_ssh2;
2022 if (cfg.compression)
2023 preferred_comp = &ssh_zlib;
2025 preferred_comp = &ssh_comp_none;
2028 * Be prepared to work around the buggy MAC problem.
2031 maclist = buggymacs, nmacs = lenof(buggymacs);
2033 maclist = macs, nmacs = lenof(macs);
2037 * Construct and send our key exchange packet.
2039 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2040 for (i = 0; i < 16; i++)
2041 ssh2_pkt_addbyte((unsigned char)random_byte());
2042 /* List key exchange algorithms. */
2043 ssh2_pkt_addstring_start();
2044 for (i = 0; i < lenof(kex_algs); i++) {
2045 ssh2_pkt_addstring_str(kex_algs[i]->name);
2046 if (i < lenof(kex_algs)-1)
2047 ssh2_pkt_addstring_str(",");
2049 /* List server host key algorithms. */
2050 ssh2_pkt_addstring_start();
2051 for (i = 0; i < lenof(hostkey_algs); i++) {
2052 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2053 if (i < lenof(hostkey_algs)-1)
2054 ssh2_pkt_addstring_str(",");
2056 /* List client->server encryption algorithms. */
2057 ssh2_pkt_addstring_start();
2058 for (i = 0; i < lenof(ciphers)+1; i++) {
2059 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2060 ssh2_pkt_addstring_str(c->name);
2061 if (i < lenof(ciphers))
2062 ssh2_pkt_addstring_str(",");
2064 /* List server->client encryption algorithms. */
2065 ssh2_pkt_addstring_start();
2066 for (i = 0; i < lenof(ciphers)+1; i++) {
2067 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2068 ssh2_pkt_addstring_str(c->name);
2069 if (i < lenof(ciphers))
2070 ssh2_pkt_addstring_str(",");
2072 /* List client->server MAC algorithms. */
2073 ssh2_pkt_addstring_start();
2074 for (i = 0; i < nmacs; i++) {
2075 ssh2_pkt_addstring_str(maclist[i]->name);
2077 ssh2_pkt_addstring_str(",");
2079 /* List server->client MAC algorithms. */
2080 ssh2_pkt_addstring_start();
2081 for (i = 0; i < nmacs; i++) {
2082 ssh2_pkt_addstring_str(maclist[i]->name);
2084 ssh2_pkt_addstring_str(",");
2086 /* List client->server compression algorithms. */
2087 ssh2_pkt_addstring_start();
2088 for (i = 0; i < lenof(compressions)+1; i++) {
2089 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2090 ssh2_pkt_addstring_str(c->name);
2091 if (i < lenof(compressions))
2092 ssh2_pkt_addstring_str(",");
2094 /* List server->client compression algorithms. */
2095 ssh2_pkt_addstring_start();
2096 for (i = 0; i < lenof(compressions)+1; i++) {
2097 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2098 ssh2_pkt_addstring_str(c->name);
2099 if (i < lenof(compressions))
2100 ssh2_pkt_addstring_str(",");
2102 /* List client->server languages. Empty list. */
2103 ssh2_pkt_addstring_start();
2104 /* List server->client languages. Empty list. */
2105 ssh2_pkt_addstring_start();
2106 /* First KEX packet does _not_ follow, because we're not that brave. */
2107 ssh2_pkt_addbool(FALSE);
2109 ssh2_pkt_adduint32(0);
2111 exhash = exhashbase;
2112 sha_string(&exhash, pktout.data+5, pktout.length-5);
2116 if (!ispkt) crWaitUntil(ispkt);
2117 sha_string(&exhash, pktin.data+5, pktin.length-5);
2120 * Now examine the other side's KEXINIT to see what we're up
2123 if (pktin.type != SSH2_MSG_KEXINIT) {
2124 bombout(("expected key exchange packet from server"));
2127 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2128 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2129 pktin.savedpos += 16; /* skip garbage cookie */
2130 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2131 for (i = 0; i < lenof(kex_algs); i++) {
2132 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2137 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2138 for (i = 0; i < lenof(hostkey_algs); i++) {
2139 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2140 hostkey = hostkey_algs[i];
2144 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2145 for (i = 0; i < lenof(ciphers)+1; i++) {
2146 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2147 if (in_commasep_string(c->name, str, len)) {
2152 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2153 for (i = 0; i < lenof(ciphers)+1; i++) {
2154 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2155 if (in_commasep_string(c->name, str, len)) {
2160 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2161 for (i = 0; i < nmacs; i++) {
2162 if (in_commasep_string(maclist[i]->name, str, len)) {
2163 csmac_tobe = maclist[i];
2167 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2168 for (i = 0; i < nmacs; i++) {
2169 if (in_commasep_string(maclist[i]->name, str, len)) {
2170 scmac_tobe = maclist[i];
2174 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2175 for (i = 0; i < lenof(compressions)+1; i++) {
2176 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2177 if (in_commasep_string(c->name, str, len)) {
2182 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2183 for (i = 0; i < lenof(compressions)+1; i++) {
2184 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2185 if (in_commasep_string(c->name, str, len)) {
2192 * Currently we only support Diffie-Hellman and DSS, so let's
2193 * bomb out if those aren't selected.
2195 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2196 bombout(("internal fault: chaos in SSH 2 transport layer"));
2201 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2204 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2209 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
2210 bombout(("expected key exchange packet from server"));
2213 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2214 f = ssh2_pkt_getmp();
2215 ssh2_pkt_getstring(&sigdata, &siglen);
2219 sha_string(&exhash, hostkeydata, hostkeylen);
2220 sha_mpint(&exhash, e);
2221 sha_mpint(&exhash, f);
2222 sha_mpint(&exhash, K);
2223 SHA_Final(&exhash, exchange_hash);
2226 debug(("Exchange hash is:\r\n"));
2227 for (i = 0; i < 20; i++)
2228 debug((" %02x", exchange_hash[i]));
2232 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2233 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2234 bombout(("Server failed host key check"));
2239 * Expect SSH2_MSG_NEWKEYS from server.
2242 if (pktin.type != SSH2_MSG_NEWKEYS) {
2243 bombout(("expected new-keys packet from server"));
2248 * Authenticate remote host: verify host key. (We've already
2249 * checked the signature of the exchange hash.)
2251 keystr = hostkey->fmtkey(hkey);
2252 fingerprint = hostkey->fingerprint(hkey);
2253 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2254 keystr, fingerprint);
2255 logevent("Host key fingerprint is:");
2256 logevent(fingerprint);
2259 hostkey->freekey(hkey);
2262 * Send SSH2_MSG_NEWKEYS.
2264 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2268 * Create and initialise session keys.
2270 cscipher = cscipher_tobe;
2271 sccipher = sccipher_tobe;
2274 cscomp = cscomp_tobe;
2275 sccomp = sccomp_tobe;
2276 cscomp->compress_init();
2277 sccomp->decompress_init();
2279 * Set IVs after keys.
2281 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2282 ssh2_mkkey(K, exchange_hash, 'D', keyspace); sccipher->setsckey(keyspace);
2283 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2284 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2285 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2286 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2289 * If this is the first key exchange phase, we must pass the
2290 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2291 * wants to see it but because it will need time to initialise
2292 * itself before it sees an actual packet. In subsequent key
2293 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2294 * it would only confuse the layer above.
2302 * Now we're encrypting. Begin returning 1 to the protocol main
2303 * function so that other things can run on top of the
2304 * transport. If we ever see a KEXINIT, we must go back to the
2309 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2310 goto begin_key_exchange;
2316 * Handle the SSH2 userauth and connection layers.
2318 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2320 static unsigned long remote_winsize;
2321 static unsigned long remote_maxpkt;
2326 * Request userauth protocol, and await a response to it.
2328 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2329 ssh2_pkt_addstring("ssh-userauth");
2331 crWaitUntilV(ispkt);
2332 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2333 bombout(("Server refused user authentication protocol"));
2338 * FIXME: currently we support only password authentication.
2339 * (This places us technically in violation of the SSH2 spec.
2340 * We must fix this.)
2344 * Get a username and a password.
2346 static char username[100];
2347 static char password[100];
2351 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2352 c_write("login as: ", 10);
2355 crWaitUntilV(!ispkt);
2356 while (inlen--) switch (c = *in++) {
2363 c_write("\b \b", 3);
2369 c_write("\b \b", 3);
2378 if (((c >= ' ' && c <= '~') ||
2379 ((unsigned char)c >= 160)) && pos < 40) {
2380 username[pos++] = c;
2387 username[strcspn(username, "\n\r")] = '\0';
2390 strncpy(username, cfg.username, 99);
2391 username[99] = '\0';
2392 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2393 sprintf(stuff, "Using username \"%s\".\r\n", username);
2394 c_write(stuff, strlen(stuff));
2398 if (ssh_get_password) {
2400 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
2401 if (!ssh_get_password(prompt, password, sizeof(password))) {
2403 * get_password failed to get a password (for
2404 * example because one was supplied on the command
2405 * line which has already failed to work).
2408 logevent("No more passwords to try");
2409 ssh_state = SSH_STATE_CLOSED;
2413 c_write("password: ", 10);
2418 crWaitUntilV(!ispkt);
2419 while (inlen--) switch (c = *in++) {
2436 if (((c >= ' ' && c <= '~') ||
2437 ((unsigned char)c >= 160)) && pos < 40)
2438 password[pos++] = c;
2445 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2446 ssh2_pkt_addstring(username);
2447 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2448 ssh2_pkt_addstring("password");
2449 ssh2_pkt_addbool(FALSE);
2450 ssh2_pkt_addstring(password);
2453 crWaitUntilV(ispkt);
2454 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2455 c_write("Access denied\r\n", 15);
2456 logevent("Authentication refused");
2462 * Now we're authenticated for the connection protocol. The
2463 * connection protocol will automatically have started at this
2464 * point; there's no need to send SERVICE_REQUEST.
2468 * So now create a channel with a session in it.
2470 mainchan = smalloc(sizeof(struct ssh_channel));
2471 mainchan->localid = 100; /* as good as any */
2472 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2473 ssh2_pkt_addstring("session");
2474 ssh2_pkt_adduint32(mainchan->localid);
2475 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2476 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2478 crWaitUntilV(ispkt);
2479 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
2480 bombout(("Server refused to open a session"));
2482 /* FIXME: error data comes back in FAILURE packet */
2484 if (ssh2_pkt_getuint32() != mainchan->localid) {
2485 bombout(("Server's channel confirmation cited wrong channel"));
2488 mainchan->remoteid = ssh2_pkt_getuint32();
2489 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2490 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2491 mainchan->u.v2.outbuffer = NULL;
2492 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
2493 logevent("Opened channel for session");
2496 * Now allocate a pty for the session.
2499 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2500 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2501 ssh2_pkt_addstring("pty-req");
2502 ssh2_pkt_addbool(1); /* want reply */
2503 ssh2_pkt_addstring(cfg.termtype);
2504 ssh2_pkt_adduint32(cols);
2505 ssh2_pkt_adduint32(rows);
2506 ssh2_pkt_adduint32(0); /* pixel width */
2507 ssh2_pkt_adduint32(0); /* pixel height */
2508 ssh2_pkt_addstring_start();
2509 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2511 ssh_state = SSH_STATE_INTERMED;
2514 crWaitUntilV(ispkt);
2515 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2516 /* FIXME: be able to handle other channels here */
2517 if (ssh2_pkt_getuint32() != mainchan->localid)
2518 continue; /* wrong channel */
2519 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2521 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2523 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2524 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2525 bombout(("Server got confused by pty request"));
2528 c_write("Server refused to allocate pty\r\n", 32);
2530 logevent("Allocated pty");
2535 * Start a shell or a remote command.
2537 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2538 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2539 if (*cfg.remote_cmd) {
2540 ssh2_pkt_addstring("exec");
2541 ssh2_pkt_addbool(1); /* want reply */
2542 ssh2_pkt_addstring(cfg.remote_cmd);
2544 ssh2_pkt_addstring("shell");
2545 ssh2_pkt_addbool(1); /* want reply */
2549 crWaitUntilV(ispkt);
2550 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2551 /* FIXME: be able to handle other channels here */
2552 if (ssh2_pkt_getuint32() != mainchan->localid)
2553 continue; /* wrong channel */
2554 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2556 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2557 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2558 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2559 bombout(("Server got confused by shell/command request"));
2562 bombout(("Server refused to start a shell/command"));
2565 logevent("Started a shell/command");
2568 ssh_state = SSH_STATE_SESSION;
2572 ssh_special(TS_EOF);
2580 static int try_send;
2584 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2585 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2588 /* FIXME: be able to handle other channels here */
2589 if (ssh2_pkt_getuint32() != mainchan->localid)
2590 continue; /* wrong channel */
2591 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2592 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2593 continue; /* extended but not stderr */
2594 ssh2_pkt_getstring(&data, &length);
2596 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2599 * Enlarge the window again at the remote side,
2600 * just in case it ever runs down and they fail
2601 * to send us any more data.
2603 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2604 ssh2_pkt_adduint32(mainchan->remoteid);
2605 ssh2_pkt_adduint32(length);
2608 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2609 ssh_state = SSH_STATE_CLOSED;
2610 logevent("Received disconnect message");
2612 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2613 continue; /* exit status et al; ignore (FIXME?) */
2614 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2615 continue; /* remote sends EOF; ignore */
2616 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2617 /* FIXME: be able to handle other channels here */
2618 if (ssh2_pkt_getuint32() != mainchan->localid)
2619 continue; /* wrong channel */
2620 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2621 ssh2_pkt_adduint32(mainchan->remoteid);
2623 /* FIXME: mark the channel as closed */
2624 if (1 /* FIXME: "all channels are closed" */) {
2625 logevent("All channels closed. Disconnecting");
2626 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2627 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
2628 ssh2_pkt_addstring("All open channels closed");
2629 ssh2_pkt_addstring("en"); /* language tag */
2631 ssh_state = SSH_STATE_CLOSED;
2634 continue; /* remote sends close; ignore (FIXME) */
2635 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2636 /* FIXME: be able to handle other channels here */
2637 if (ssh2_pkt_getuint32() != mainchan->localid)
2638 continue; /* wrong channel */
2639 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2642 bombout(("Strange packet received: type %d", pktin.type));
2647 * We have spare data. Add it to the channel buffer.
2649 if (mainchan->u.v2.outbufsize <
2650 mainchan->u.v2.outbuflen + inlen) {
2651 mainchan->u.v2.outbufsize =
2652 mainchan->u.v2.outbuflen + inlen + 1024;
2653 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2654 mainchan->u.v2.outbufsize);
2656 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2658 mainchan->u.v2.outbuflen += inlen;
2663 * Try to send data on the channel if we can. (FIXME:
2664 * on _all_ channels.)
2666 while (mainchan->u.v2.remwindow > 0 &&
2667 mainchan->u.v2.outbuflen > 0) {
2668 unsigned len = mainchan->u.v2.remwindow;
2669 if (len > mainchan->u.v2.outbuflen)
2670 len = mainchan->u.v2.outbuflen;
2671 if (len > mainchan->u.v2.remmaxpkt)
2672 len = mainchan->u.v2.remmaxpkt;
2673 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2674 ssh2_pkt_adduint32(mainchan->remoteid);
2675 ssh2_pkt_addstring_start();
2676 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2678 mainchan->u.v2.outbuflen -= len;
2679 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2680 mainchan->u.v2.outbuflen);
2681 mainchan->u.v2.remwindow -= len;
2690 * Handle the top-level SSH2 protocol.
2692 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2694 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2696 do_ssh2_authconn(in, inlen, ispkt);
2700 * Called to set up the connection.
2702 * Returns an error message, or NULL on success.
2704 static char *ssh_init (char *host, int port, char **realhost) {
2708 if(crypto_startup() == 0)
2709 return "Microsoft high encryption pack not installed!";
2714 p = connect_to_host(host, port, realhost);
2722 * Called to send data down the Telnet connection.
2724 static void ssh_send (char *buf, int len) {
2725 if (s == NULL || ssh_protocol == NULL)
2728 ssh_protocol(buf, len, 0);
2732 * Called to set the size of the window from SSH's POV.
2734 static void ssh_size(void) {
2735 switch (ssh_state) {
2736 case SSH_STATE_BEFORE_SIZE:
2737 case SSH_STATE_PREPACKET:
2738 case SSH_STATE_CLOSED:
2739 break; /* do nothing */
2740 case SSH_STATE_INTERMED:
2741 size_needed = TRUE; /* buffer for later */
2743 case SSH_STATE_SESSION:
2745 if (ssh_version == 1) {
2746 send_packet(SSH1_CMSG_WINDOW_SIZE,
2747 PKT_INT, rows, PKT_INT, cols,
2748 PKT_INT, 0, PKT_INT, 0, PKT_END);
2750 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2751 ssh2_pkt_adduint32(mainchan->remoteid);
2752 ssh2_pkt_addstring("window-change");
2753 ssh2_pkt_addbool(0);
2754 ssh2_pkt_adduint32(cols);
2755 ssh2_pkt_adduint32(rows);
2756 ssh2_pkt_adduint32(0);
2757 ssh2_pkt_adduint32(0);
2766 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2767 * can send an EOF and collect resulting output (e.g. `plink
2770 static void ssh_special (Telnet_Special code) {
2771 if (code == TS_EOF) {
2772 if (ssh_state != SSH_STATE_SESSION) {
2774 * Buffer the EOF in case we are pre-SESSION, so we can
2775 * send it as soon as we reach SESSION.
2781 if (ssh_version == 1) {
2782 send_packet(SSH1_CMSG_EOF, PKT_END);
2784 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
2785 ssh2_pkt_adduint32(mainchan->remoteid);
2788 logevent("Sent EOF message");
2789 } else if (code == TS_PING) {
2790 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
2792 if (ssh_version == 1) {
2793 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
2795 ssh2_pkt_init(SSH2_MSG_IGNORE);
2796 ssh2_pkt_addstring_start();
2804 static Socket ssh_socket(void) { return s; }
2806 static int ssh_sendok(void) { return ssh_send_ok; }
2808 Backend ssh_backend = {