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;
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 */
260 SSH_STATE_BEFORE_SIZE,
264 } ssh_state = SSH_STATE_BEFORE_SIZE;
266 static int size_needed = FALSE;
268 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
269 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
271 static int ssh_version;
272 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
273 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
274 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
275 static void ssh_size(void);
277 static int (*s_rdpkt)(unsigned char **data, int *datalen);
279 static struct rdpkt1_state_tag {
280 long len, pad, biglen, to_read;
281 unsigned long realcrc, gotcrc;
287 static struct rdpkt2_state_tag {
288 long len, pad, payload, packetlen, maclen;
291 unsigned long incoming_sequence;
294 static int ssh_channelcmp(void *av, void *bv) {
295 struct ssh_channel *a = (struct ssh_channel *)av;
296 struct ssh_channel *b = (struct ssh_channel *)bv;
297 if (a->localid < b->localid) return -1;
298 if (a->localid > b->localid) return +1;
301 static int ssh_channelfind(void *av, void *bv) {
302 unsigned *a = (unsigned *)av;
303 struct ssh_channel *b = (struct ssh_channel *)bv;
304 if (*a < b->localid) return -1;
305 if (*a > b->localid) return +1;
309 static void c_write (char *buf, int len) {
310 if ((flags & FLAG_STDERR)) {
312 for (i = 0; i < len; i++)
314 fputc(buf[i], stderr);
317 from_backend(1, buf, len);
321 * Collect incoming data in the incoming packet buffer.
322 * Decipher and verify the packet when it is completely read.
323 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
324 * Update the *data and *datalen variables.
325 * Return the additional nr of bytes needed, or 0 when
326 * a complete packet is available.
328 static int ssh1_rdpkt(unsigned char **data, int *datalen)
330 struct rdpkt1_state_tag *st = &rdpkt1_state;
339 for (st->i = st->len = 0; st->i < 4; st->i++) {
340 while ((*datalen) == 0)
342 st->len = (st->len << 8) + **data;
343 (*data)++, (*datalen)--;
347 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
348 st->len = 0x300; /* big enough to carry to end */
352 st->pad = 8 - (st->len % 8);
353 st->biglen = st->len + st->pad;
354 pktin.length = st->len - 5;
356 if (pktin.maxlen < st->biglen) {
357 pktin.maxlen = st->biglen;
358 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
359 srealloc(pktin.data, st->biglen+APIEXTRA));
361 fatalbox("Out of memory");
364 st->to_read = st->biglen;
366 while (st->to_read > 0) {
367 st->chunk = st->to_read;
368 while ((*datalen) == 0)
369 crReturn(st->to_read);
370 if (st->chunk > (*datalen))
371 st->chunk = (*datalen);
372 memcpy(st->p, *data, st->chunk);
374 *datalen -= st->chunk;
376 st->to_read -= st->chunk;
380 cipher->decrypt(pktin.data, st->biglen);
382 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
383 for (st->i = 0; st->i < st->biglen; st->i++)
384 debug((" %02x", (unsigned char)pktin.data[st->i]));
388 st->realcrc = crc32(pktin.data, st->biglen-4);
389 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
390 if (st->gotcrc != st->realcrc) {
391 bombout(("Incorrect CRC received on packet"));
395 pktin.body = pktin.data + st->pad + 1;
397 if (ssh1_compressing) {
398 unsigned char *decompblk;
402 debug(("Packet payload pre-decompression:\n"));
403 for (i = -1; i < pktin.length; i++)
404 debug((" %02x", (unsigned char)pktin.body[i]));
407 zlib_decompress_block(pktin.body-1, pktin.length+1,
408 &decompblk, &decomplen);
410 if (pktin.maxlen < st->pad + decomplen) {
411 pktin.maxlen = st->pad + decomplen;
412 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
413 pktin.body = pktin.data + st->pad + 1;
415 fatalbox("Out of memory");
418 memcpy(pktin.body-1, decompblk, decomplen);
420 pktin.length = decomplen-1;
422 debug(("Packet payload post-decompression:\n"));
423 for (i = -1; i < pktin.length; i++)
424 debug((" %02x", (unsigned char)pktin.body[i]));
429 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
430 pktin.type == SSH1_SMSG_STDERR_DATA ||
431 pktin.type == SSH1_MSG_DEBUG ||
432 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
433 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
434 long strlen = GET_32BIT(pktin.body);
435 if (strlen + 4 != pktin.length) {
436 bombout(("Received data packet with bogus string length"));
441 pktin.type = pktin.body[-1];
443 if (pktin.type == SSH1_MSG_DEBUG) {
444 /* log debug message */
446 int strlen = GET_32BIT(pktin.body);
447 strcpy(buf, "Remote: ");
448 if (strlen > 70) strlen = 70;
449 memcpy(buf+8, pktin.body+4, strlen);
450 buf[8+strlen] = '\0';
453 } else if (pktin.type == SSH1_MSG_IGNORE) {
461 static int ssh2_rdpkt(unsigned char **data, int *datalen)
463 struct rdpkt2_state_tag *st = &rdpkt2_state;
471 st->cipherblk = sccipher->blksize;
474 if (st->cipherblk < 8)
477 if (pktin.maxlen < st->cipherblk) {
478 pktin.maxlen = st->cipherblk;
479 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
480 srealloc(pktin.data, st->cipherblk+APIEXTRA));
482 fatalbox("Out of memory");
486 * Acquire and decrypt the first block of the packet. This will
487 * contain the length and padding details.
489 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
490 while ((*datalen) == 0)
491 crReturn(st->cipherblk-st->i);
492 pktin.data[st->i] = *(*data)++;
496 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
501 sccipher->decrypt(pktin.data, st->cipherblk);
504 * Now get the length and padding figures.
506 st->len = GET_32BIT(pktin.data);
507 st->pad = pktin.data[4];
510 * This enables us to deduce the payload length.
512 st->payload = st->len - st->pad - 1;
514 pktin.length = st->payload + 5;
517 * So now we can work out the total packet length.
519 st->packetlen = st->len + 4;
520 st->maclen = scmac ? scmac->len : 0;
523 * Adjust memory allocation if packet is too big.
525 if (pktin.maxlen < st->packetlen+st->maclen) {
526 pktin.maxlen = st->packetlen+st->maclen;
527 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
528 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
530 fatalbox("Out of memory");
534 * Read and decrypt the remainder of the packet.
536 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
537 while ((*datalen) == 0)
538 crReturn(st->packetlen + st->maclen - st->i);
539 pktin.data[st->i] = *(*data)++;
542 /* Decrypt everything _except_ the MAC. */
544 sccipher->decrypt(pktin.data + st->cipherblk,
545 st->packetlen - st->cipherblk);
548 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
549 for (st->i = 0; st->i < st->packetlen; st->i++)
550 debug((" %02x", (unsigned char)pktin.data[st->i]));
557 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
558 bombout(("Incorrect MAC received on packet"));
561 st->incoming_sequence++; /* whether or not we MACed */
564 * Decompress packet payload.
567 unsigned char *newpayload;
569 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
570 &newpayload, &newlen)) {
571 if (pktin.maxlen < newlen+5) {
572 pktin.maxlen = newlen+5;
573 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
574 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
576 fatalbox("Out of memory");
578 pktin.length = 5 + newlen;
579 memcpy(pktin.data+5, newpayload, newlen);
581 debug(("Post-decompression payload:\r\n"));
582 for (st->i = 0; st->i < newlen; st->i++)
583 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
592 pktin.type = pktin.data[5];
594 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
595 goto next_packet; /* FIXME: print DEBUG message */
600 static void ssh1_pktout_size(int len) {
603 len += 5; /* type and CRC */
607 pktout.length = len-5;
608 if (pktout.maxlen < biglen) {
609 pktout.maxlen = biglen;
611 /* Allocate enough buffer space for extra block
612 * for MS CryptEncrypt() */
613 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
614 srealloc(pktout.data, biglen+12));
616 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
617 srealloc(pktout.data, biglen+4));
620 fatalbox("Out of memory");
622 pktout.body = pktout.data+4+pad+1;
625 static void s_wrpkt_start(int type, int len) {
626 ssh1_pktout_size(len);
630 static void s_wrpkt(void) {
631 int pad, len, biglen, i;
634 pktout.body[-1] = pktout.type;
636 if (ssh1_compressing) {
637 unsigned char *compblk;
640 debug(("Packet payload pre-compression:\n"));
641 for (i = -1; i < pktout.length; i++)
642 debug((" %02x", (unsigned char)pktout.body[i]));
645 zlib_compress_block(pktout.body-1, pktout.length+1,
647 ssh1_pktout_size(complen-1);
648 memcpy(pktout.body-1, compblk, complen);
651 debug(("Packet payload post-compression:\n"));
652 for (i = -1; i < pktout.length; i++)
653 debug((" %02x", (unsigned char)pktout.body[i]));
658 len = pktout.length + 5; /* type and CRC */
662 for (i=0; i<pad; i++)
663 pktout.data[i+4] = random_byte();
664 crc = crc32(pktout.data+4, biglen-4);
665 PUT_32BIT(pktout.data+biglen, crc);
666 PUT_32BIT(pktout.data, len);
669 debug(("Sending packet len=%d\r\n", biglen+4));
670 for (i = 0; i < biglen+4; i++)
671 debug((" %02x", (unsigned char)pktout.data[i]));
675 cipher->encrypt(pktout.data+4, biglen);
677 sk_write(s, pktout.data, biglen+4);
681 * Construct a packet with the specified contents and
682 * send it to the server.
684 static void send_packet(int pkttype, ...)
687 unsigned char *p, *argp, argchar;
688 unsigned long argint;
689 int pktlen, argtype, arglen;
693 va_start(args, pkttype);
694 while ((argtype = va_arg(args, int)) != PKT_END) {
697 (void) va_arg(args, int);
701 (void) va_arg(args, char);
705 (void) va_arg(args, unsigned char *);
706 arglen = va_arg(args, int);
710 argp = va_arg(args, unsigned char *);
711 arglen = strlen(argp);
712 pktlen += 4 + arglen;
715 bn = va_arg(args, Bignum);
716 pktlen += ssh1_bignum_length(bn);
724 s_wrpkt_start(pkttype, pktlen);
727 va_start(args, pkttype);
728 while ((argtype = va_arg(args, int)) != PKT_END) {
731 argint = va_arg(args, int);
732 PUT_32BIT(p, argint);
736 argchar = va_arg(args, unsigned char);
741 argp = va_arg(args, unsigned char *);
742 arglen = va_arg(args, int);
743 memcpy(p, argp, arglen);
747 argp = va_arg(args, unsigned char *);
748 arglen = strlen(argp);
749 PUT_32BIT(p, arglen);
750 memcpy(p + 4, argp, arglen);
754 bn = va_arg(args, Bignum);
755 p += ssh1_write_bignum(p, bn);
764 static int ssh_versioncmp(char *a, char *b) {
766 unsigned long av, bv;
768 av = strtoul(a, &ae, 10);
769 bv = strtoul(b, &be, 10);
770 if (av != bv) return (av < bv ? -1 : +1);
771 if (*ae == '.') ae++;
772 if (*be == '.') be++;
773 av = strtoul(ae, &ae, 10);
774 bv = strtoul(be, &be, 10);
775 if (av != bv) return (av < bv ? -1 : +1);
781 * Utility routine for putting an SSH-protocol `string' into a SHA
785 static void sha_string(SHA_State *s, void *str, int len) {
786 unsigned char lenblk[4];
787 PUT_32BIT(lenblk, len);
788 SHA_Bytes(s, lenblk, 4);
789 SHA_Bytes(s, str, len);
793 * SSH2 packet construction functions.
795 static void ssh2_pkt_adddata(void *data, int len) {
796 pktout.length += len;
797 if (pktout.maxlen < pktout.length) {
798 pktout.maxlen = pktout.length + 256;
799 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
800 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
802 fatalbox("Out of memory");
804 memcpy(pktout.data+pktout.length-len, data, len);
806 static void ssh2_pkt_addbyte(unsigned char byte) {
807 ssh2_pkt_adddata(&byte, 1);
809 static void ssh2_pkt_init(int pkt_type) {
811 ssh2_pkt_addbyte((unsigned char)pkt_type);
813 static void ssh2_pkt_addbool(unsigned char value) {
814 ssh2_pkt_adddata(&value, 1);
816 static void ssh2_pkt_adduint32(unsigned long value) {
819 ssh2_pkt_adddata(x, 4);
821 static void ssh2_pkt_addstring_start(void) {
822 ssh2_pkt_adduint32(0);
823 pktout.savedpos = pktout.length;
825 static void ssh2_pkt_addstring_str(char *data) {
826 ssh2_pkt_adddata(data, strlen(data));
827 PUT_32BIT(pktout.data + pktout.savedpos - 4,
828 pktout.length - pktout.savedpos);
830 static void ssh2_pkt_addstring_data(char *data, int len) {
831 ssh2_pkt_adddata(data, len);
832 PUT_32BIT(pktout.data + pktout.savedpos - 4,
833 pktout.length - pktout.savedpos);
835 static void ssh2_pkt_addstring(char *data) {
836 ssh2_pkt_addstring_start();
837 ssh2_pkt_addstring_str(data);
839 static char *ssh2_mpint_fmt(Bignum b, int *len) {
842 p = smalloc(n * 2 + 1);
844 fatalbox("out of memory");
846 for (i = 0; i < n; i++) {
847 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
848 p[i*2+2] = (b[n-i] ) & 0xFF;
851 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
853 memmove(p, p+i, n*2+1-i);
857 static void ssh2_pkt_addmp(Bignum b) {
860 p = ssh2_mpint_fmt(b, &len);
861 ssh2_pkt_addstring_start();
862 ssh2_pkt_addstring_data(p, len);
865 static void ssh2_pkt_send(void) {
866 int cipherblk, maclen, padding, i;
867 static unsigned long outgoing_sequence = 0;
870 * Compress packet payload.
873 debug(("Pre-compression payload:\r\n"));
874 for (i = 5; i < pktout.length; i++)
875 debug((" %02x", (unsigned char)pktout.data[i]));
879 unsigned char *newpayload;
881 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
882 &newpayload, &newlen)) {
884 ssh2_pkt_adddata(newpayload, newlen);
890 * Add padding. At least four bytes, and must also bring total
891 * length (minus MAC) up to a multiple of the block size.
893 cipherblk = cipher ? cipher->blksize : 8; /* block size */
894 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
896 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
897 pktout.data[4] = padding;
898 for (i = 0; i < padding; i++)
899 pktout.data[pktout.length + i] = random_byte();
900 PUT_32BIT(pktout.data, pktout.length + padding - 4);
902 csmac->generate(pktout.data, pktout.length + padding,
904 outgoing_sequence++; /* whether or not we MACed */
907 debug(("Sending packet len=%d\r\n", pktout.length+padding));
908 for (i = 0; i < pktout.length+padding; i++)
909 debug((" %02x", (unsigned char)pktout.data[i]));
914 cscipher->encrypt(pktout.data, pktout.length + padding);
915 maclen = csmac ? csmac->len : 0;
917 sk_write(s, pktout.data, pktout.length + padding + maclen);
921 void bndebug(char *string, Bignum b) {
924 p = ssh2_mpint_fmt(b, &len);
925 debug(("%s", string));
926 for (i = 0; i < len; i++)
927 debug((" %02x", p[i]));
933 static void sha_mpint(SHA_State *s, Bignum b) {
936 p = ssh2_mpint_fmt(b, &len);
937 sha_string(s, p, len);
942 * SSH2 packet decode functions.
944 static unsigned long ssh2_pkt_getuint32(void) {
946 if (pktin.length - pktin.savedpos < 4)
947 return 0; /* arrgh, no way to decline (FIXME?) */
948 value = GET_32BIT(pktin.data+pktin.savedpos);
952 static void ssh2_pkt_getstring(char **p, int *length) {
954 if (pktin.length - pktin.savedpos < 4)
956 *length = GET_32BIT(pktin.data+pktin.savedpos);
958 if (pktin.length - pktin.savedpos < *length)
960 *p = pktin.data+pktin.savedpos;
961 pktin.savedpos += *length;
963 static Bignum ssh2_pkt_getmp(void) {
968 ssh2_pkt_getstring(&p, &length);
972 bombout(("internal error: Can't handle negative mpints"));
975 b = newbn((length+1)/2);
976 for (i = 0; i < length; i++) {
979 b[j/2+1] |= ((unsigned char)p[i]) << 8;
981 b[j/2+1] |= ((unsigned char)p[i]);
983 while (b[0] > 1 && b[b[0]] == 0) b[0]--;
987 static int do_ssh_init(unsigned char c) {
989 static char version[10];
990 static char vstring[80];
991 static char vlog[sizeof(vstring)+20];
996 /* Search for the string "SSH-" in the input. */
999 static const int transS[] = { 1, 2, 2, 1 };
1000 static const int transH[] = { 0, 0, 3, 0 };
1001 static const int transminus[] = { 0, 0, 0, -1 };
1002 if (c == 'S') i = transS[i];
1003 else if (c == 'H') i = transH[i];
1004 else if (c == '-') i = transminus[i];
1008 crReturn(1); /* get another character */
1011 strcpy(vstring, "SSH-");
1015 crReturn(1); /* get another char */
1016 if (vsp < vstring+sizeof(vstring)-1)
1022 } else if (i < sizeof(version)-1)
1029 ssh_agentfwd_enabled = FALSE;
1030 rdpkt2_state.incoming_sequence = 0;
1033 sprintf(vlog, "Server version: %s", vstring);
1034 vlog[strcspn(vlog, "\r\n")] = '\0';
1038 * Server version "1.99" means we can choose whether we use v1
1039 * or v2 protocol. Choice is based on cfg.sshprot.
1041 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1043 * This is a v2 server. Begin v2 protocol.
1045 char *verstring = "SSH-2.0-PuTTY";
1048 * Hash our version string and their version string.
1050 sha_string(&exhash, verstring, strlen(verstring));
1051 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
1052 sprintf(vstring, "%s\n", verstring);
1053 sprintf(vlog, "We claim version: %s", verstring);
1055 logevent("Using SSH protocol version 2");
1056 sk_write(s, vstring, strlen(vstring));
1057 ssh_protocol = ssh2_protocol;
1059 s_rdpkt = ssh2_rdpkt;
1062 * This is a v1 server. Begin v1 protocol.
1064 sprintf(vstring, "SSH-%s-PuTTY\n",
1065 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1066 sprintf(vlog, "We claim version: %s", vstring);
1067 vlog[strcspn(vlog, "\r\n")] = '\0';
1069 logevent("Using SSH protocol version 1");
1070 sk_write(s, vstring, strlen(vstring));
1071 ssh_protocol = ssh1_protocol;
1073 s_rdpkt = ssh1_rdpkt;
1079 static void ssh_gotdata(unsigned char *data, int datalen)
1084 * To begin with, feed the characters one by one to the
1085 * protocol initialisation / selection function do_ssh_init().
1086 * When that returns 0, we're done with the initial greeting
1087 * exchange and can move on to packet discipline.
1092 crReturnV; /* more data please */
1093 ret = do_ssh_init(*data);
1100 * We emerge from that loop when the initial negotiation is
1101 * over and we have selected an s_rdpkt function. Now pass
1102 * everything to s_rdpkt, and then pass the resulting packets
1103 * to the proper protocol handler.
1108 while (datalen > 0) {
1109 if ( s_rdpkt(&data, &datalen) == 0 ) {
1110 ssh_protocol(NULL, 0, 1);
1111 if (ssh_state == SSH_STATE_CLOSED) {
1121 static int ssh_receive(Socket skt, int urgent, char *data, int len) {
1123 /* Connection has closed. */
1128 ssh_gotdata (data, len);
1129 if (ssh_state == SSH_STATE_CLOSED) {
1140 * Connect to specified host and port.
1141 * Returns an error message, or NULL on success.
1142 * Also places the canonical host name into `realhost'.
1144 static char *connect_to_host(char *host, int port, char **realhost)
1153 savedhost = smalloc(1+strlen(host));
1155 fatalbox("Out of memory");
1156 strcpy(savedhost, host);
1159 port = 22; /* default ssh port */
1172 addr = sk_namelookup(host, realhost);
1173 if ( (err = sk_addr_error(addr)) )
1183 s = sk_new(addr, port, ssh_receive);
1184 if ( (err = sk_socket_error(s)) )
1188 sk_write(s, "connect ", 8);
1189 sk_write(s, FWhost, strlen(FWhost));
1192 sprintf(buf, " %d\n", FWport);
1193 sk_write(s, buf, strlen(buf));
1201 * Handle the key exchange and user authentication phases.
1203 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1206 unsigned char *rsabuf, *keystr1, *keystr2;
1207 unsigned char cookie[8];
1208 struct RSAKey servkey, hostkey;
1209 struct MD5Context md5c;
1210 static unsigned long supported_ciphers_mask, supported_auths_mask;
1211 static int tried_publickey;
1212 static unsigned char session_id[16];
1214 static char username[100];
1218 if (!ispkt) crWaitUntil(ispkt);
1220 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1221 bombout(("Public key packet not received"));
1225 logevent("Received public keys");
1227 memcpy(cookie, pktin.body, 8);
1229 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1230 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1233 * Log the host key fingerprint.
1237 logevent("Host key fingerprint is:");
1238 strcpy(logmsg, " ");
1239 hostkey.comment = NULL;
1240 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1245 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1246 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1249 MD5Update(&md5c, keystr2, hostkey.bytes);
1250 MD5Update(&md5c, keystr1, servkey.bytes);
1251 MD5Update(&md5c, pktin.body, 8);
1252 MD5Final(session_id, &md5c);
1254 for (i=0; i<32; i++)
1255 session_key[i] = random_byte();
1257 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1259 rsabuf = smalloc(len);
1261 fatalbox("Out of memory");
1264 * Verify the host key.
1268 * First format the key into a string.
1270 int len = rsastr_len(&hostkey);
1271 char fingerprint[100];
1272 char *keystr = smalloc(len);
1274 fatalbox("Out of memory");
1275 rsastr_fmt(keystr, &hostkey);
1276 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1277 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1281 for (i=0; i<32; i++) {
1282 rsabuf[i] = session_key[i];
1284 rsabuf[i] ^= session_id[i];
1287 if (hostkey.bytes > servkey.bytes) {
1288 rsaencrypt(rsabuf, 32, &servkey);
1289 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1291 rsaencrypt(rsabuf, 32, &hostkey);
1292 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1295 logevent("Encrypted session key");
1297 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
1298 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
1300 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1301 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1302 cipher_type = SSH_CIPHER_3DES;
1304 switch (cipher_type) {
1305 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1306 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1307 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1310 send_packet(SSH1_CMSG_SESSION_KEY,
1311 PKT_CHAR, cipher_type,
1312 PKT_DATA, cookie, 8,
1313 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1314 PKT_DATA, rsabuf, len,
1318 logevent("Trying to enable encryption...");
1322 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1323 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1325 cipher->sesskey(session_key);
1329 if (pktin.type != SSH1_SMSG_SUCCESS) {
1330 bombout(("Encryption not successfully enabled"));
1334 logevent("Successfully started encryption");
1340 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1341 c_write("login as: ", 10);
1344 crWaitUntil(!ispkt);
1345 while (inlen--) switch (c = *in++) {
1352 c_write("\b \b", 3);
1358 c_write("\b \b", 3);
1367 if (((c >= ' ' && c <= '~') ||
1368 ((unsigned char)c >= 160)) && pos < 40) {
1369 username[pos++] = c;
1376 username[strcspn(username, "\n\r")] = '\0';
1378 strncpy(username, cfg.username, 99);
1379 username[99] = '\0';
1382 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1384 char userlog[22+sizeof(username)];
1385 sprintf(userlog, "Sent username \"%s\"", username);
1387 if (flags & FLAG_INTERACTIVE &&
1388 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1389 strcat(userlog, "\r\n");
1390 c_write(userlog, strlen(userlog));
1397 tried_publickey = 0;
1399 while (pktin.type == SSH1_SMSG_FAILURE) {
1400 static char password[100];
1401 static char prompt[200];
1404 static int pwpkt_type;
1406 * Show password prompt, having first obtained it via a TIS
1407 * or CryptoCard exchange if we're doing TIS or CryptoCard
1410 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1411 if (agent_exists()) {
1413 * Attempt RSA authentication using Pageant.
1415 static unsigned char request[5], *response, *p;
1416 static int responselen;
1417 static int i, nkeys;
1418 static int authed = FALSE;
1421 logevent("Pageant is running. Requesting keys.");
1423 /* Request the keys held by the agent. */
1424 PUT_32BIT(request, 1);
1425 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1426 agent_query(request, 5, &r, &responselen);
1427 response = (unsigned char *)r;
1430 nkeys = GET_32BIT(p); p += 4;
1431 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1433 for (i = 0; i < nkeys; i++) {
1434 static struct RSAKey key;
1435 static Bignum challenge;
1436 static char *commentp;
1437 static int commentlen;
1439 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1442 p += ssh1_read_bignum(p, &key.exponent);
1443 p += ssh1_read_bignum(p, &key.modulus);
1444 commentlen = GET_32BIT(p); p += 4;
1445 commentp = p; p += commentlen;
1446 send_packet(SSH1_CMSG_AUTH_RSA,
1447 PKT_BIGNUM, key.modulus, PKT_END);
1449 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1450 logevent("Key refused");
1453 logevent("Received RSA challenge");
1454 ssh1_read_bignum(pktin.body, &challenge);
1456 char *agentreq, *q, *ret;
1458 len = 1 + 4; /* message type, bit count */
1459 len += ssh1_bignum_length(key.exponent);
1460 len += ssh1_bignum_length(key.modulus);
1461 len += ssh1_bignum_length(challenge);
1462 len += 16; /* session id */
1463 len += 4; /* response format */
1464 agentreq = smalloc(4 + len);
1465 PUT_32BIT(agentreq, len);
1467 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1468 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1470 q += ssh1_write_bignum(q, key.exponent);
1471 q += ssh1_write_bignum(q, key.modulus);
1472 q += ssh1_write_bignum(q, challenge);
1473 memcpy(q, session_id, 16); q += 16;
1474 PUT_32BIT(q, 1); /* response format */
1475 agent_query(agentreq, len+4, &ret, &retlen);
1478 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1479 logevent("Sending Pageant's response");
1480 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1481 PKT_DATA, ret+5, 16, PKT_END);
1484 if (pktin.type == SSH1_SMSG_SUCCESS) {
1485 logevent("Pageant's response accepted");
1486 if (flags & FLAG_VERBOSE) {
1487 c_write("Authenticated using RSA key \"",
1489 c_write(commentp, commentlen);
1490 c_write("\" from agent\r\n", 14);
1494 logevent("Pageant's response not accepted");
1496 logevent("Pageant failed to answer challenge");
1500 logevent("No reply received from Pageant");
1503 freebn(key.exponent);
1504 freebn(key.modulus);
1513 if (*cfg.keyfile && !tried_publickey)
1514 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1516 if (pktin.type == SSH1_SMSG_FAILURE &&
1518 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1519 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1520 logevent("Requested TIS authentication");
1521 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1523 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1524 logevent("TIS authentication declined");
1525 if (flags & FLAG_INTERACTIVE)
1526 c_write("TIS authentication refused.\r\n", 29);
1528 int challengelen = ((pktin.body[0] << 24) |
1529 (pktin.body[1] << 16) |
1530 (pktin.body[2] << 8) |
1532 logevent("Received TIS challenge");
1533 if (challengelen > sizeof(prompt)-1)
1534 challengelen = sizeof(prompt)-1; /* prevent overrun */
1535 memcpy(prompt, pktin.body+4, challengelen);
1536 prompt[challengelen] = '\0';
1539 if (pktin.type == SSH1_SMSG_FAILURE &&
1541 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1542 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1543 logevent("Requested CryptoCard authentication");
1544 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1546 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1547 logevent("CryptoCard authentication declined");
1548 c_write("CryptoCard authentication refused.\r\n", 29);
1550 int challengelen = ((pktin.body[0] << 24) |
1551 (pktin.body[1] << 16) |
1552 (pktin.body[2] << 8) |
1554 logevent("Received CryptoCard challenge");
1555 if (challengelen > sizeof(prompt)-1)
1556 challengelen = sizeof(prompt)-1; /* prevent overrun */
1557 memcpy(prompt, pktin.body+4, challengelen);
1558 strncpy(prompt + challengelen, "\r\nResponse : ",
1559 sizeof(prompt)-challengelen);
1560 prompt[sizeof(prompt)-1] = '\0';
1563 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1564 sprintf(prompt, "%.90s@%.90s's password: ",
1565 username, savedhost);
1567 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1568 char *comment = NULL;
1569 if (flags & FLAG_VERBOSE)
1570 c_write("Trying public key authentication.\r\n", 35);
1571 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1572 if (flags & FLAG_VERBOSE)
1573 c_write("No passphrase required.\r\n", 25);
1576 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1580 if (ssh_get_password) {
1581 if (!ssh_get_password(prompt, password, sizeof(password))) {
1583 * get_password failed to get a password (for
1584 * example because one was supplied on the command
1585 * line which has already failed to work).
1588 logevent("No more passwords to try");
1589 ssh_state = SSH_STATE_CLOSED;
1593 c_write(prompt, strlen(prompt));
1597 crWaitUntil(!ispkt);
1598 while (inlen--) switch (c = *in++) {
1615 if (((c >= ' ' && c <= '~') ||
1616 ((unsigned char)c >= 160)) && pos < sizeof(password))
1617 password[pos++] = c;
1625 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1627 * Try public key authentication with the specified
1630 static struct RSAKey pubkey;
1631 static Bignum challenge, response;
1633 static unsigned char buffer[32];
1635 tried_publickey = 1;
1636 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
1638 c_write("Couldn't load public key from ", 30);
1639 c_write(cfg.keyfile, strlen(cfg.keyfile));
1640 c_write(".\r\n", 3);
1641 continue; /* go and try password */
1644 c_write("Wrong passphrase.\r\n", 19);
1645 tried_publickey = 0;
1646 continue; /* try again */
1650 * Send a public key attempt.
1652 send_packet(SSH1_CMSG_AUTH_RSA,
1653 PKT_BIGNUM, pubkey.modulus, PKT_END);
1656 if (pktin.type == SSH1_SMSG_FAILURE) {
1657 c_write("Server refused our public key.\r\n", 32);
1658 continue; /* go and try password */
1660 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1661 bombout(("Bizarre response to offer of public key"));
1664 ssh1_read_bignum(pktin.body, &challenge);
1665 response = rsadecrypt(challenge, &pubkey);
1666 freebn(pubkey.private_exponent); /* burn the evidence */
1668 for (i = 0; i < 32; i += 2) {
1669 buffer[i] = response[16-i/2] >> 8;
1670 buffer[i+1] = response[16-i/2] & 0xFF;
1674 MD5Update(&md5c, buffer, 32);
1675 MD5Update(&md5c, session_id, 16);
1676 MD5Final(buffer, &md5c);
1678 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1679 PKT_DATA, buffer, 16, PKT_END);
1682 if (pktin.type == SSH1_SMSG_FAILURE) {
1683 if (flags & FLAG_VERBOSE)
1684 c_write("Failed to authenticate with our public key.\r\n",
1686 continue; /* go and try password */
1687 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1688 bombout(("Bizarre response to RSA authentication response"));
1692 break; /* we're through! */
1694 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1696 logevent("Sent password");
1697 memset(password, 0, strlen(password));
1699 if (pktin.type == SSH1_SMSG_FAILURE) {
1700 if (flags & FLAG_VERBOSE)
1701 c_write("Access denied\r\n", 15);
1702 logevent("Authentication refused");
1703 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1704 logevent("Received disconnect request");
1705 ssh_state = SSH_STATE_CLOSED;
1707 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1708 bombout(("Strange packet received, type %d", pktin.type));
1713 logevent("Authentication successful");
1718 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1723 while (!do_ssh1_login(in, inlen, ispkt)) {
1726 if (ssh_state == SSH_STATE_CLOSED)
1729 if (cfg.agentfwd && agent_exists()) {
1730 logevent("Requesting agent forwarding");
1731 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1732 do { crReturnV; } while (!ispkt);
1733 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1734 bombout(("Protocol confusion"));
1736 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1737 logevent("Agent forwarding refused");
1739 logevent("Agent forwarding enabled");
1740 ssh_agentfwd_enabled = TRUE;
1745 send_packet(SSH1_CMSG_REQUEST_PTY,
1746 PKT_STR, cfg.termtype,
1747 PKT_INT, rows, PKT_INT, cols,
1748 PKT_INT, 0, PKT_INT, 0,
1751 ssh_state = SSH_STATE_INTERMED;
1752 do { crReturnV; } while (!ispkt);
1753 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1754 bombout(("Protocol confusion"));
1756 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1757 c_write("Server refused to allocate pty\r\n", 32);
1759 logevent("Allocated pty");
1762 if (cfg.compression) {
1763 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1764 do { crReturnV; } while (!ispkt);
1765 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1766 bombout(("Protocol confusion"));
1768 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1769 c_write("Server refused to compress\r\n", 32);
1771 logevent("Started compression");
1772 ssh1_compressing = TRUE;
1773 zlib_compress_init();
1774 zlib_decompress_init();
1777 if (*cfg.remote_cmd)
1778 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1780 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1781 logevent("Started session");
1783 ssh_state = SSH_STATE_SESSION;
1788 ssh_channels = newtree234(ssh_channelcmp);
1793 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1794 pktin.type == SSH1_SMSG_STDERR_DATA) {
1795 long len = GET_32BIT(pktin.body);
1796 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1798 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1799 ssh_state = SSH_STATE_CLOSED;
1800 logevent("Received disconnect request");
1802 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1803 /* Remote side is trying to open a channel to talk to our
1804 * agent. Give them back a local channel number. */
1806 struct ssh_channel *c;
1809 /* Refuse if agent forwarding is disabled. */
1810 if (!ssh_agentfwd_enabled) {
1811 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1812 PKT_INT, GET_32BIT(pktin.body),
1816 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1818 break; /* found a free number */
1821 c = smalloc(sizeof(struct ssh_channel));
1822 c->remoteid = GET_32BIT(pktin.body);
1825 c->type = SSH1_SMSG_AGENT_OPEN;/* identify channel type */
1826 c->u.a.lensofar = 0;
1827 add234(ssh_channels, c);
1828 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1829 PKT_INT, c->remoteid, PKT_INT, c->localid,
1832 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1833 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1834 /* Remote side closes a channel. */
1835 unsigned i = GET_32BIT(pktin.body);
1836 struct ssh_channel *c;
1837 c = find234(ssh_channels, &i, ssh_channelfind);
1840 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1841 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1842 c->closes |= closetype;
1843 if (c->closes == 3) {
1844 del234(ssh_channels, c);
1848 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1849 /* Data sent down one of our channels. */
1850 int i = GET_32BIT(pktin.body);
1851 int len = GET_32BIT(pktin.body+4);
1852 unsigned char *p = pktin.body+8;
1853 struct ssh_channel *c;
1854 c = find234(ssh_channels, &i, ssh_channelfind);
1857 case SSH1_SMSG_AGENT_OPEN:
1858 /* Data for an agent message. Buffer it. */
1860 if (c->u.a.lensofar < 4) {
1861 int l = min(4 - c->u.a.lensofar, len);
1862 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1863 p += l; len -= l; c->u.a.lensofar += l;
1865 if (c->u.a.lensofar == 4) {
1866 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1867 c->u.a.message = smalloc(c->u.a.totallen);
1868 memcpy(c->u.a.message, c->u.a.msglen, 4);
1870 if (c->u.a.lensofar >= 4 && len > 0) {
1871 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1872 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1873 p += l; len -= l; c->u.a.lensofar += l;
1875 if (c->u.a.lensofar == c->u.a.totallen) {
1876 void *reply, *sentreply;
1878 agent_query(c->u.a.message, c->u.a.totallen,
1883 /* Fake SSH_AGENT_FAILURE. */
1884 sentreply = "\0\0\0\1\5";
1887 send_packet(SSH1_MSG_CHANNEL_DATA,
1888 PKT_INT, c->remoteid,
1890 PKT_DATA, sentreply, replylen,
1894 sfree(c->u.a.message);
1895 c->u.a.lensofar = 0;
1901 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
1902 /* may be from EXEC_SHELL on some servers */
1903 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1904 /* may be from EXEC_SHELL on some servers
1905 * if no pty is available or in other odd cases. Ignore */
1906 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1907 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
1909 bombout(("Strange packet received: type %d", pktin.type));
1914 int len = min(inlen, 512);
1915 send_packet(SSH1_CMSG_STDIN_DATA,
1916 PKT_INT, len, PKT_DATA, in, len, PKT_END);
1927 * Utility routine for decoding comma-separated strings in KEXINIT.
1929 static int in_commasep_string(char *needle, char *haystack, int haylen) {
1930 int needlen = strlen(needle);
1933 * Is it at the start of the string?
1935 if (haylen >= needlen && /* haystack is long enough */
1936 !memcmp(needle, haystack, needlen) && /* initial match */
1937 (haylen == needlen || haystack[needlen] == ',')
1938 /* either , or EOS follows */
1942 * If not, search for the next comma and resume after that.
1943 * If no comma found, terminate.
1945 while (haylen > 0 && *haystack != ',')
1946 haylen--, haystack++;
1949 haylen--, haystack++; /* skip over comma itself */
1954 * SSH2 key creation method.
1956 static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1958 /* First 20 bytes. */
1961 SHA_Bytes(&s, H, 20);
1962 SHA_Bytes(&s, &chr, 1);
1963 SHA_Bytes(&s, H, 20);
1964 SHA_Final(&s, keyspace);
1965 /* Next 20 bytes. */
1968 SHA_Bytes(&s, H, 20);
1969 SHA_Bytes(&s, keyspace, 20);
1970 SHA_Final(&s, keyspace+20);
1974 * Handle the SSH2 transport layer.
1976 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
1980 static Bignum e, f, K;
1981 static const struct ssh_mac **maclist;
1983 static const struct ssh_cipher *cscipher_tobe = NULL;
1984 static const struct ssh_cipher *sccipher_tobe = NULL;
1985 static const struct ssh_mac *csmac_tobe = NULL;
1986 static const struct ssh_mac *scmac_tobe = NULL;
1987 static const struct ssh_compress *cscomp_tobe = NULL;
1988 static const struct ssh_compress *sccomp_tobe = NULL;
1989 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
1990 static int hostkeylen, siglen;
1991 static void *hkey; /* actual host key */
1992 static unsigned char exchange_hash[20];
1993 static unsigned char keyspace[40];
1994 static const struct ssh_cipher *preferred_cipher;
1995 static const struct ssh_compress *preferred_comp;
2001 * Set up the preferred cipher and compression.
2003 if (cfg.cipher == CIPHER_BLOWFISH) {
2004 preferred_cipher = &ssh_blowfish_ssh2;
2005 } else if (cfg.cipher == CIPHER_DES) {
2006 logevent("Single DES not supported in SSH2; using 3DES");
2007 preferred_cipher = &ssh_3des_ssh2;
2008 } else if (cfg.cipher == CIPHER_3DES) {
2009 preferred_cipher = &ssh_3des_ssh2;
2011 /* Shouldn't happen, but we do want to initialise to _something_. */
2012 preferred_cipher = &ssh_3des_ssh2;
2014 if (cfg.compression)
2015 preferred_comp = &ssh_zlib;
2017 preferred_comp = &ssh_comp_none;
2020 * Be prepared to work around the buggy MAC problem.
2023 maclist = buggymacs, nmacs = lenof(buggymacs);
2025 maclist = macs, nmacs = lenof(macs);
2029 * Construct and send our key exchange packet.
2031 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2032 for (i = 0; i < 16; i++)
2033 ssh2_pkt_addbyte((unsigned char)random_byte());
2034 /* List key exchange algorithms. */
2035 ssh2_pkt_addstring_start();
2036 for (i = 0; i < lenof(kex_algs); i++) {
2037 ssh2_pkt_addstring_str(kex_algs[i]->name);
2038 if (i < lenof(kex_algs)-1)
2039 ssh2_pkt_addstring_str(",");
2041 /* List server host key algorithms. */
2042 ssh2_pkt_addstring_start();
2043 for (i = 0; i < lenof(hostkey_algs); i++) {
2044 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2045 if (i < lenof(hostkey_algs)-1)
2046 ssh2_pkt_addstring_str(",");
2048 /* List client->server encryption algorithms. */
2049 ssh2_pkt_addstring_start();
2050 for (i = 0; i < lenof(ciphers)+1; i++) {
2051 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2052 ssh2_pkt_addstring_str(c->name);
2053 if (i < lenof(ciphers))
2054 ssh2_pkt_addstring_str(",");
2056 /* List server->client 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 client->server MAC algorithms. */
2065 ssh2_pkt_addstring_start();
2066 for (i = 0; i < nmacs; i++) {
2067 ssh2_pkt_addstring_str(maclist[i]->name);
2069 ssh2_pkt_addstring_str(",");
2071 /* List server->client MAC algorithms. */
2072 ssh2_pkt_addstring_start();
2073 for (i = 0; i < nmacs; i++) {
2074 ssh2_pkt_addstring_str(maclist[i]->name);
2076 ssh2_pkt_addstring_str(",");
2078 /* List client->server compression algorithms. */
2079 ssh2_pkt_addstring_start();
2080 for (i = 0; i < lenof(compressions)+1; i++) {
2081 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2082 ssh2_pkt_addstring_str(c->name);
2083 if (i < lenof(compressions))
2084 ssh2_pkt_addstring_str(",");
2086 /* List server->client 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 client->server languages. Empty list. */
2095 ssh2_pkt_addstring_start();
2096 /* List server->client languages. Empty list. */
2097 ssh2_pkt_addstring_start();
2098 /* First KEX packet does _not_ follow, because we're not that brave. */
2099 ssh2_pkt_addbool(FALSE);
2101 ssh2_pkt_adduint32(0);
2102 sha_string(&exhash, pktout.data+5, pktout.length-5);
2105 if (!ispkt) crWaitUntil(ispkt);
2106 sha_string(&exhash, pktin.data+5, pktin.length-5);
2109 * Now examine the other side's KEXINIT to see what we're up
2112 if (pktin.type != SSH2_MSG_KEXINIT) {
2113 bombout(("expected key exchange packet from server"));
2116 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2117 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2118 pktin.savedpos += 16; /* skip garbage cookie */
2119 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2120 for (i = 0; i < lenof(kex_algs); i++) {
2121 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2126 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2127 for (i = 0; i < lenof(hostkey_algs); i++) {
2128 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2129 hostkey = hostkey_algs[i];
2133 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2134 for (i = 0; i < lenof(ciphers)+1; i++) {
2135 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2136 if (in_commasep_string(c->name, str, len)) {
2141 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2142 for (i = 0; i < lenof(ciphers)+1; i++) {
2143 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2144 if (in_commasep_string(c->name, str, len)) {
2149 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2150 for (i = 0; i < nmacs; i++) {
2151 if (in_commasep_string(maclist[i]->name, str, len)) {
2152 csmac_tobe = maclist[i];
2156 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2157 for (i = 0; i < nmacs; i++) {
2158 if (in_commasep_string(maclist[i]->name, str, len)) {
2159 scmac_tobe = maclist[i];
2163 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2164 for (i = 0; i < lenof(compressions)+1; i++) {
2165 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2166 if (in_commasep_string(c->name, str, len)) {
2171 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2172 for (i = 0; i < lenof(compressions)+1; i++) {
2173 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2174 if (in_commasep_string(c->name, str, len)) {
2181 * Currently we only support Diffie-Hellman and DSS, so let's
2182 * bomb out if those aren't selected.
2184 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2185 bombout(("internal fault: chaos in SSH 2 transport layer"));
2190 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2193 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2198 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
2199 bombout(("expected key exchange packet from server"));
2202 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2203 f = ssh2_pkt_getmp();
2204 ssh2_pkt_getstring(&sigdata, &siglen);
2208 sha_string(&exhash, hostkeydata, hostkeylen);
2209 sha_mpint(&exhash, e);
2210 sha_mpint(&exhash, f);
2211 sha_mpint(&exhash, K);
2212 SHA_Final(&exhash, exchange_hash);
2215 debug(("Exchange hash is:\r\n"));
2216 for (i = 0; i < 20; i++)
2217 debug((" %02x", exchange_hash[i]));
2221 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2222 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2223 bombout(("Server failed host key check"));
2228 * Expect SSH2_MSG_NEWKEYS from server.
2231 if (pktin.type != SSH2_MSG_NEWKEYS) {
2232 bombout(("expected new-keys packet from server"));
2237 * Authenticate remote host: verify host key. (We've already
2238 * checked the signature of the exchange hash.)
2240 keystr = hostkey->fmtkey(hkey);
2241 fingerprint = hostkey->fingerprint(hkey);
2242 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2243 keystr, fingerprint);
2244 logevent("Host key fingerprint is:");
2245 logevent(fingerprint);
2248 hostkey->freekey(hkey);
2251 * Send SSH2_MSG_NEWKEYS.
2253 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2257 * Create and initialise session keys.
2259 cscipher = cscipher_tobe;
2260 sccipher = sccipher_tobe;
2263 cscomp = cscomp_tobe;
2264 sccomp = sccomp_tobe;
2265 cscomp->compress_init();
2266 sccomp->decompress_init();
2268 * Set IVs after keys.
2270 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2271 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2272 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2273 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2274 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2275 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2278 * Now we're encrypting. Begin returning 1 to the protocol main
2279 * function so that other things can run on top of the
2280 * transport. If we ever see a KEXINIT, we must go back to the
2285 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2286 goto begin_key_exchange;
2292 * Handle the SSH2 userauth and connection layers.
2294 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2296 static unsigned long remote_winsize;
2297 static unsigned long remote_maxpkt;
2302 * Request userauth protocol, and await a response to it.
2304 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2305 ssh2_pkt_addstring("ssh-userauth");
2307 crWaitUntilV(ispkt);
2308 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2309 bombout(("Server refused user authentication protocol"));
2314 * FIXME: currently we support only password authentication.
2315 * (This places us technically in violation of the SSH2 spec.
2316 * We must fix this.)
2320 * Get a username and a password.
2322 static char username[100];
2323 static char password[100];
2327 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2328 c_write("login as: ", 10);
2331 crWaitUntilV(!ispkt);
2332 while (inlen--) switch (c = *in++) {
2339 c_write("\b \b", 3);
2345 c_write("\b \b", 3);
2354 if (((c >= ' ' && c <= '~') ||
2355 ((unsigned char)c >= 160)) && pos < 40) {
2356 username[pos++] = c;
2363 username[strcspn(username, "\n\r")] = '\0';
2366 strncpy(username, cfg.username, 99);
2367 username[99] = '\0';
2368 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2369 sprintf(stuff, "Using username \"%s\".\r\n", username);
2370 c_write(stuff, strlen(stuff));
2374 if (ssh_get_password) {
2376 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
2377 if (!ssh_get_password(prompt, password, sizeof(password))) {
2379 * get_password failed to get a password (for
2380 * example because one was supplied on the command
2381 * line which has already failed to work).
2384 logevent("No more passwords to try");
2385 ssh_state = SSH_STATE_CLOSED;
2389 c_write("password: ", 10);
2394 crWaitUntilV(!ispkt);
2395 while (inlen--) switch (c = *in++) {
2412 if (((c >= ' ' && c <= '~') ||
2413 ((unsigned char)c >= 160)) && pos < 40)
2414 password[pos++] = c;
2421 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2422 ssh2_pkt_addstring(username);
2423 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2424 ssh2_pkt_addstring("password");
2425 ssh2_pkt_addbool(FALSE);
2426 ssh2_pkt_addstring(password);
2429 crWaitUntilV(ispkt);
2430 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2431 c_write("Access denied\r\n", 15);
2432 logevent("Authentication refused");
2438 * Now we're authenticated for the connection protocol. The
2439 * connection protocol will automatically have started at this
2440 * point; there's no need to send SERVICE_REQUEST.
2444 * So now create a channel with a session in it.
2446 mainchan = smalloc(sizeof(struct ssh_channel));
2447 mainchan->localid = 100; /* as good as any */
2448 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2449 ssh2_pkt_addstring("session");
2450 ssh2_pkt_adduint32(mainchan->localid);
2451 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2452 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2454 crWaitUntilV(ispkt);
2455 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
2456 bombout(("Server refused to open a session"));
2458 /* FIXME: error data comes back in FAILURE packet */
2460 if (ssh2_pkt_getuint32() != mainchan->localid) {
2461 bombout(("Server's channel confirmation cited wrong channel"));
2464 mainchan->remoteid = ssh2_pkt_getuint32();
2465 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2466 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2467 mainchan->u.v2.outbuffer = NULL;
2468 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
2469 logevent("Opened channel for session");
2472 * Now allocate a pty for the session.
2475 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2476 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2477 ssh2_pkt_addstring("pty-req");
2478 ssh2_pkt_addbool(1); /* want reply */
2479 ssh2_pkt_addstring(cfg.termtype);
2480 ssh2_pkt_adduint32(cols);
2481 ssh2_pkt_adduint32(rows);
2482 ssh2_pkt_adduint32(0); /* pixel width */
2483 ssh2_pkt_adduint32(0); /* pixel height */
2484 ssh2_pkt_addstring_start();
2485 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2487 ssh_state = SSH_STATE_INTERMED;
2490 crWaitUntilV(ispkt);
2491 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2492 /* FIXME: be able to handle other channels here */
2493 if (ssh2_pkt_getuint32() != mainchan->localid)
2494 continue; /* wrong channel */
2495 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2497 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2499 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2500 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2501 bombout(("Server got confused by pty request"));
2504 c_write("Server refused to allocate pty\r\n", 32);
2506 logevent("Allocated pty");
2511 * Start a shell or a remote command.
2513 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2514 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2515 if (*cfg.remote_cmd) {
2516 ssh2_pkt_addstring("exec");
2517 ssh2_pkt_addbool(1); /* want reply */
2518 ssh2_pkt_addstring(cfg.remote_cmd);
2520 ssh2_pkt_addstring("shell");
2521 ssh2_pkt_addbool(1); /* want reply */
2525 crWaitUntilV(ispkt);
2526 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2527 /* FIXME: be able to handle other channels here */
2528 if (ssh2_pkt_getuint32() != mainchan->localid)
2529 continue; /* wrong channel */
2530 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2532 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2533 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2534 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2535 bombout(("Server got confused by shell/command request"));
2538 bombout(("Server refused to start a shell/command"));
2541 logevent("Started a shell/command");
2544 ssh_state = SSH_STATE_SESSION;
2554 static int try_send;
2558 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2559 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2562 /* FIXME: be able to handle other channels here */
2563 if (ssh2_pkt_getuint32() != mainchan->localid)
2564 continue; /* wrong channel */
2565 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2566 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2567 continue; /* extended but not stderr */
2568 ssh2_pkt_getstring(&data, &length);
2570 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2573 * Enlarge the window again at the remote side,
2574 * just in case it ever runs down and they fail
2575 * to send us any more data.
2577 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2578 ssh2_pkt_adduint32(mainchan->remoteid);
2579 ssh2_pkt_adduint32(length);
2582 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2583 ssh_state = SSH_STATE_CLOSED;
2584 logevent("Received disconnect message");
2586 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2587 continue; /* exit status et al; ignore (FIXME?) */
2588 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2589 continue; /* remote sends EOF; ignore */
2590 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2591 /* FIXME: be able to handle other channels here */
2592 if (ssh2_pkt_getuint32() != mainchan->localid)
2593 continue; /* wrong channel */
2594 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2595 ssh2_pkt_adduint32(mainchan->remoteid);
2597 /* FIXME: mark the channel as closed */
2598 if (1 /* FIXME: "all channels are closed" */) {
2599 logevent("All channels closed. Disconnecting");
2600 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2601 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
2602 ssh2_pkt_addstring("All open channels closed");
2603 ssh2_pkt_addstring("en"); /* language tag */
2605 ssh_state = SSH_STATE_CLOSED;
2608 continue; /* remote sends close; ignore (FIXME) */
2609 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2610 /* FIXME: be able to handle other channels here */
2611 if (ssh2_pkt_getuint32() != mainchan->localid)
2612 continue; /* wrong channel */
2613 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2616 bombout(("Strange packet received: type %d", pktin.type));
2621 * We have spare data. Add it to the channel buffer.
2623 if (mainchan->u.v2.outbufsize <
2624 mainchan->u.v2.outbuflen + inlen) {
2625 mainchan->u.v2.outbufsize =
2626 mainchan->u.v2.outbuflen + inlen + 1024;
2627 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2628 mainchan->u.v2.outbufsize);
2630 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2632 mainchan->u.v2.outbuflen += inlen;
2637 * Try to send data on the channel if we can. (FIXME:
2638 * on _all_ channels.)
2640 while (mainchan->u.v2.remwindow > 0 &&
2641 mainchan->u.v2.outbuflen > 0) {
2642 unsigned len = mainchan->u.v2.remwindow;
2643 if (len > mainchan->u.v2.outbuflen)
2644 len = mainchan->u.v2.outbuflen;
2645 if (len > mainchan->u.v2.remmaxpkt)
2646 len = mainchan->u.v2.remmaxpkt;
2647 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2648 ssh2_pkt_adduint32(mainchan->remoteid);
2649 ssh2_pkt_addstring_start();
2650 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2652 mainchan->u.v2.outbuflen -= len;
2653 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2654 mainchan->u.v2.outbuflen);
2655 mainchan->u.v2.remwindow -= len;
2664 * Handle the top-level SSH2 protocol.
2666 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2668 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2670 do_ssh2_authconn(in, inlen, ispkt);
2674 * Called to set up the connection.
2676 * Returns an error message, or NULL on success.
2678 static char *ssh_init (char *host, int port, char **realhost) {
2682 if(crypto_startup() == 0)
2683 return "Microsoft high encryption pack not installed!";
2688 p = connect_to_host(host, port, realhost);
2696 * Called to send data down the Telnet connection.
2698 static void ssh_send (char *buf, int len) {
2699 if (s == NULL || ssh_protocol == NULL)
2702 ssh_protocol(buf, len, 0);
2706 * Called to set the size of the window from SSH's POV.
2708 static void ssh_size(void) {
2709 switch (ssh_state) {
2710 case SSH_STATE_BEFORE_SIZE:
2711 case SSH_STATE_CLOSED:
2712 break; /* do nothing */
2713 case SSH_STATE_INTERMED:
2714 size_needed = TRUE; /* buffer for later */
2716 case SSH_STATE_SESSION:
2718 if (ssh_version == 1) {
2719 send_packet(SSH1_CMSG_WINDOW_SIZE,
2720 PKT_INT, rows, PKT_INT, cols,
2721 PKT_INT, 0, PKT_INT, 0, PKT_END);
2723 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2724 ssh2_pkt_adduint32(mainchan->remoteid);
2725 ssh2_pkt_addstring("window-change");
2726 ssh2_pkt_addbool(0);
2727 ssh2_pkt_adduint32(cols);
2728 ssh2_pkt_adduint32(rows);
2729 ssh2_pkt_adduint32(0);
2730 ssh2_pkt_adduint32(0);
2738 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2739 * can send an EOF and collect resulting output (e.g. `plink
2742 static void ssh_special (Telnet_Special code) {
2743 if (code == TS_EOF) {
2744 if (ssh_version == 1) {
2745 send_packet(SSH1_CMSG_EOF, PKT_END);
2747 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
2748 ssh2_pkt_adduint32(mainchan->remoteid);
2751 logevent("Sent EOF message");
2752 } else if (code == TS_PING) {
2753 if (ssh_version == 1) {
2754 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
2756 ssh2_pkt_init(SSH2_MSG_IGNORE);
2757 ssh2_pkt_addstring_start();
2765 static Socket ssh_socket(void) { return s; }
2767 static int ssh_sendok(void) { return ssh_send_ok; }
2769 Backend ssh_backend = {