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, \
23 (s ? sk_close(s), s = NULL : (void)0), \
24 connection_fatal msg )
26 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29 #define SSH1_CMSG_USER 4 /* 0x4 */
30 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
39 #define SSH1_SMSG_FAILURE 15 /* 0xf */
40 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43 #define SSH1_CMSG_EOF 19 /* 0x13 */
44 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
50 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
53 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
55 #define SSH1_MSG_IGNORE 32 /* 0x20 */
56 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
59 #define SSH1_MSG_DEBUG 36 /* 0x24 */
60 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
61 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
68 #define SSH1_AUTH_TIS 5 /* 0x5 */
69 #define SSH1_AUTH_CCARD 16 /* 0x10 */
71 #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
72 #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
73 #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
74 #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
75 #define SSH_AGENT_FAILURE 5 /* 0x5 */
76 #define SSH_AGENT_SUCCESS 6 /* 0x6 */
77 #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
78 #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
80 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
81 #define SSH2_MSG_IGNORE 2 /* 0x2 */
82 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
83 #define SSH2_MSG_DEBUG 4 /* 0x4 */
84 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
85 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
86 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
87 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
88 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
89 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
90 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
91 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
92 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
93 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
94 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
95 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
96 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
97 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
98 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
99 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
100 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
101 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
102 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
103 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
104 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
105 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
106 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
107 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
108 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
109 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
111 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
112 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
113 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
114 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
115 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
116 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
117 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
118 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
119 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
120 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
121 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
123 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
124 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
125 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
126 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
128 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
130 #define GET_32BIT(cp) \
131 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
132 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
133 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
134 ((unsigned long)(unsigned char)(cp)[3]))
136 #define PUT_32BIT(cp, value) { \
137 (cp)[0] = (unsigned char)((value) >> 24); \
138 (cp)[1] = (unsigned char)((value) >> 16); \
139 (cp)[2] = (unsigned char)((value) >> 8); \
140 (cp)[3] = (unsigned char)(value); }
142 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
144 /* Coroutine mechanics for the sillier bits of the code */
145 #define crBegin1 static int crLine = 0;
146 #define crBegin2 switch(crLine) { case 0:;
147 #define crBegin crBegin1; crBegin2;
148 #define crFinish(z) } crLine = 0; return (z)
149 #define crFinishV } crLine = 0; return
150 #define crReturn(z) \
152 crLine=__LINE__; return (z); case __LINE__:;\
156 crLine=__LINE__; return; case __LINE__:;\
158 #define crStop(z) do{ crLine = 0; return (z); }while(0)
159 #define crStopV do{ crLine = 0; return; }while(0)
160 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
161 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
163 extern const struct ssh_cipher ssh_3des;
164 extern const struct ssh_cipher ssh_3des_ssh2;
165 extern const struct ssh_cipher ssh_des;
166 extern const struct ssh_cipher ssh_blowfish_ssh1;
167 extern const struct ssh_cipher ssh_blowfish_ssh2;
169 extern char *x11_init (Socket *, char *, void *);
170 extern void x11_close (Socket);
171 extern void x11_send (Socket , char *, int);
172 extern void x11_invent_auth(char *, int, char *, int);
175 * Ciphers for SSH2. We miss out single-DES because it isn't
176 * supported; also 3DES and Blowfish are both done differently from
177 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
178 * endianness and different-sized keys.)
180 const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
182 extern const struct ssh_kex ssh_diffiehellman;
183 const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
185 extern const struct ssh_signkey ssh_dss;
186 const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss };
188 extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
190 static void nullmac_key(unsigned char *key) { }
191 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
192 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
193 const static struct ssh_mac ssh_mac_none = {
194 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
196 const static struct ssh_mac *macs[] = {
197 &ssh_sha1, &ssh_md5, &ssh_mac_none };
198 const static struct ssh_mac *buggymacs[] = {
199 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
201 static void ssh_comp_none_init(void) { }
202 static int ssh_comp_none_block(unsigned char *block, int len,
203 unsigned char **outblock, int *outlen) {
206 const static struct ssh_compress ssh_comp_none = {
208 ssh_comp_none_init, ssh_comp_none_block,
209 ssh_comp_none_init, ssh_comp_none_block
211 extern const struct ssh_compress ssh_zlib;
212 const static struct ssh_compress *compressions[] = {
213 &ssh_zlib, &ssh_comp_none };
215 enum { /* channel types */
222 * 2-3-4 tree storing channels.
225 unsigned remoteid, localid;
228 struct ssh2_data_channel {
229 unsigned char *outbuffer;
230 unsigned outbuflen, outbufsize;
231 unsigned remwindow, remmaxpkt;
234 struct ssh_agent_channel {
235 unsigned char *message;
236 unsigned char msglen[4];
237 int lensofar, totallen;
239 struct ssh_x11_channel {
254 static SHA_State exhash, exhashbase;
256 static Socket s = NULL;
258 static unsigned char session_key[32];
259 static int ssh1_compressing;
260 static int ssh_agentfwd_enabled;
261 static int ssh_X11_fwd_enabled;
262 static const struct ssh_cipher *cipher = NULL;
263 static const struct ssh_cipher *cscipher = NULL;
264 static const struct ssh_cipher *sccipher = NULL;
265 static const struct ssh_mac *csmac = NULL;
266 static const struct ssh_mac *scmac = NULL;
267 static const struct ssh_compress *cscomp = NULL;
268 static const struct ssh_compress *sccomp = NULL;
269 static const struct ssh_kex *kex = NULL;
270 static const struct ssh_signkey *hostkey = NULL;
271 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
273 static char *savedhost;
274 static int savedport;
275 static int ssh_send_ok;
276 static int ssh_echoing, ssh_editing;
278 static tree234 *ssh_channels; /* indexed by local id */
279 static struct ssh_channel *mainchan; /* primary session channel */
283 SSH_STATE_BEFORE_SIZE,
287 } ssh_state = SSH_STATE_PREPACKET;
289 static int size_needed = FALSE, eof_needed = FALSE;
291 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
292 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
294 static int ssh_version;
295 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
296 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
297 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
298 static void ssh_size(void);
299 static void ssh_special (Telnet_Special);
300 static void ssh2_try_send(struct ssh_channel *c);
301 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
303 static int (*s_rdpkt)(unsigned char **data, int *datalen);
305 static struct rdpkt1_state_tag {
306 long len, pad, biglen, to_read;
307 unsigned long realcrc, gotcrc;
313 static struct rdpkt2_state_tag {
314 long len, pad, payload, packetlen, maclen;
317 unsigned long incoming_sequence;
320 static int ssh_channelcmp(void *av, void *bv) {
321 struct ssh_channel *a = (struct ssh_channel *)av;
322 struct ssh_channel *b = (struct ssh_channel *)bv;
323 if (a->localid < b->localid) return -1;
324 if (a->localid > b->localid) return +1;
327 static int ssh_channelfind(void *av, void *bv) {
328 unsigned *a = (unsigned *)av;
329 struct ssh_channel *b = (struct ssh_channel *)bv;
330 if (*a < b->localid) return -1;
331 if (*a > b->localid) return +1;
335 static void c_write (char *buf, int len) {
336 if ((flags & FLAG_STDERR)) {
338 for (i = 0; i < len; i++)
340 fputc(buf[i], stderr);
343 from_backend(1, buf, len);
347 * Collect incoming data in the incoming packet buffer.
348 * Decipher and verify the packet when it is completely read.
349 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
350 * Update the *data and *datalen variables.
351 * Return the additional nr of bytes needed, or 0 when
352 * a complete packet is available.
354 static int ssh1_rdpkt(unsigned char **data, int *datalen)
356 struct rdpkt1_state_tag *st = &rdpkt1_state;
365 for (st->i = st->len = 0; st->i < 4; st->i++) {
366 while ((*datalen) == 0)
368 st->len = (st->len << 8) + **data;
369 (*data)++, (*datalen)--;
373 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
374 st->len = 0x300; /* big enough to carry to end */
378 st->pad = 8 - (st->len % 8);
379 st->biglen = st->len + st->pad;
380 pktin.length = st->len - 5;
382 if (pktin.maxlen < st->biglen) {
383 pktin.maxlen = st->biglen;
384 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
385 srealloc(pktin.data, st->biglen+APIEXTRA));
387 fatalbox("Out of memory");
390 st->to_read = st->biglen;
392 while (st->to_read > 0) {
393 st->chunk = st->to_read;
394 while ((*datalen) == 0)
395 crReturn(st->to_read);
396 if (st->chunk > (*datalen))
397 st->chunk = (*datalen);
398 memcpy(st->p, *data, st->chunk);
400 *datalen -= st->chunk;
402 st->to_read -= st->chunk;
406 cipher->decrypt(pktin.data, st->biglen);
408 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
409 for (st->i = 0; st->i < st->biglen; st->i++)
410 debug((" %02x", (unsigned char)pktin.data[st->i]));
414 st->realcrc = crc32(pktin.data, st->biglen-4);
415 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
416 if (st->gotcrc != st->realcrc) {
417 bombout(("Incorrect CRC received on packet"));
421 pktin.body = pktin.data + st->pad + 1;
423 if (ssh1_compressing) {
424 unsigned char *decompblk;
428 debug(("Packet payload pre-decompression:\n"));
429 for (i = -1; i < pktin.length; i++)
430 debug((" %02x", (unsigned char)pktin.body[i]));
433 zlib_decompress_block(pktin.body-1, pktin.length+1,
434 &decompblk, &decomplen);
436 if (pktin.maxlen < st->pad + decomplen) {
437 pktin.maxlen = st->pad + decomplen;
438 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
439 pktin.body = pktin.data + st->pad + 1;
441 fatalbox("Out of memory");
444 memcpy(pktin.body-1, decompblk, decomplen);
446 pktin.length = decomplen-1;
448 debug(("Packet payload post-decompression:\n"));
449 for (i = -1; i < pktin.length; i++)
450 debug((" %02x", (unsigned char)pktin.body[i]));
455 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
456 pktin.type == SSH1_SMSG_STDERR_DATA ||
457 pktin.type == SSH1_MSG_DEBUG ||
458 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
459 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
460 long strlen = GET_32BIT(pktin.body);
461 if (strlen + 4 != pktin.length) {
462 bombout(("Received data packet with bogus string length"));
467 pktin.type = pktin.body[-1];
469 if (pktin.type == SSH1_MSG_DEBUG) {
470 /* log debug message */
472 int strlen = GET_32BIT(pktin.body);
473 strcpy(buf, "Remote: ");
474 if (strlen > 70) strlen = 70;
475 memcpy(buf+8, pktin.body+4, strlen);
476 buf[8+strlen] = '\0';
479 } else if (pktin.type == SSH1_MSG_IGNORE) {
487 static int ssh2_rdpkt(unsigned char **data, int *datalen)
489 struct rdpkt2_state_tag *st = &rdpkt2_state;
497 st->cipherblk = sccipher->blksize;
500 if (st->cipherblk < 8)
503 if (pktin.maxlen < st->cipherblk) {
504 pktin.maxlen = st->cipherblk;
505 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
506 srealloc(pktin.data, st->cipherblk+APIEXTRA));
508 fatalbox("Out of memory");
512 * Acquire and decrypt the first block of the packet. This will
513 * contain the length and padding details.
515 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
516 while ((*datalen) == 0)
517 crReturn(st->cipherblk-st->i);
518 pktin.data[st->i] = *(*data)++;
522 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
527 sccipher->decrypt(pktin.data, st->cipherblk);
530 * Now get the length and padding figures.
532 st->len = GET_32BIT(pktin.data);
533 st->pad = pktin.data[4];
536 * This enables us to deduce the payload length.
538 st->payload = st->len - st->pad - 1;
540 pktin.length = st->payload + 5;
543 * So now we can work out the total packet length.
545 st->packetlen = st->len + 4;
546 st->maclen = scmac ? scmac->len : 0;
549 * Adjust memory allocation if packet is too big.
551 if (pktin.maxlen < st->packetlen+st->maclen) {
552 pktin.maxlen = st->packetlen+st->maclen;
553 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
554 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
556 fatalbox("Out of memory");
560 * Read and decrypt the remainder of the packet.
562 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
563 while ((*datalen) == 0)
564 crReturn(st->packetlen + st->maclen - st->i);
565 pktin.data[st->i] = *(*data)++;
568 /* Decrypt everything _except_ the MAC. */
570 sccipher->decrypt(pktin.data + st->cipherblk,
571 st->packetlen - st->cipherblk);
574 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
575 for (st->i = 0; st->i < st->packetlen; st->i++)
576 debug((" %02x", (unsigned char)pktin.data[st->i]));
583 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
584 bombout(("Incorrect MAC received on packet"));
587 st->incoming_sequence++; /* whether or not we MACed */
590 * Decompress packet payload.
593 unsigned char *newpayload;
595 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
596 &newpayload, &newlen)) {
597 if (pktin.maxlen < newlen+5) {
598 pktin.maxlen = newlen+5;
599 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
600 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
602 fatalbox("Out of memory");
604 pktin.length = 5 + newlen;
605 memcpy(pktin.data+5, newpayload, newlen);
607 debug(("Post-decompression payload:\r\n"));
608 for (st->i = 0; st->i < newlen; st->i++)
609 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
618 pktin.type = pktin.data[5];
620 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
621 goto next_packet; /* FIXME: print DEBUG message */
626 static void ssh1_pktout_size(int len) {
629 len += 5; /* type and CRC */
633 pktout.length = len-5;
634 if (pktout.maxlen < biglen) {
635 pktout.maxlen = biglen;
637 /* Allocate enough buffer space for extra block
638 * for MS CryptEncrypt() */
639 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
640 srealloc(pktout.data, biglen+12));
642 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
643 srealloc(pktout.data, biglen+4));
646 fatalbox("Out of memory");
648 pktout.body = pktout.data+4+pad+1;
651 static void s_wrpkt_start(int type, int len) {
652 ssh1_pktout_size(len);
656 static void s_wrpkt(void) {
657 int pad, len, biglen, i;
660 pktout.body[-1] = pktout.type;
662 if (ssh1_compressing) {
663 unsigned char *compblk;
666 debug(("Packet payload pre-compression:\n"));
667 for (i = -1; i < pktout.length; i++)
668 debug((" %02x", (unsigned char)pktout.body[i]));
671 zlib_compress_block(pktout.body-1, pktout.length+1,
673 ssh1_pktout_size(complen-1);
674 memcpy(pktout.body-1, compblk, complen);
677 debug(("Packet payload post-compression:\n"));
678 for (i = -1; i < pktout.length; i++)
679 debug((" %02x", (unsigned char)pktout.body[i]));
684 len = pktout.length + 5; /* type and CRC */
688 for (i=0; i<pad; i++)
689 pktout.data[i+4] = random_byte();
690 crc = crc32(pktout.data+4, biglen-4);
691 PUT_32BIT(pktout.data+biglen, crc);
692 PUT_32BIT(pktout.data, len);
695 debug(("Sending packet len=%d\r\n", biglen+4));
696 for (i = 0; i < biglen+4; i++)
697 debug((" %02x", (unsigned char)pktout.data[i]));
701 cipher->encrypt(pktout.data+4, biglen);
703 sk_write(s, pktout.data, biglen+4);
707 * Construct a packet with the specified contents and
708 * send it to the server.
710 static void send_packet(int pkttype, ...)
713 unsigned char *p, *argp, argchar;
714 unsigned long argint;
715 int pktlen, argtype, arglen;
719 va_start(args, pkttype);
720 while ((argtype = va_arg(args, int)) != PKT_END) {
723 (void) va_arg(args, int);
727 (void) va_arg(args, char);
731 (void) va_arg(args, unsigned char *);
732 arglen = va_arg(args, int);
736 argp = va_arg(args, unsigned char *);
737 arglen = strlen(argp);
738 pktlen += 4 + arglen;
741 bn = va_arg(args, Bignum);
742 pktlen += ssh1_bignum_length(bn);
750 s_wrpkt_start(pkttype, pktlen);
753 va_start(args, pkttype);
754 while ((argtype = va_arg(args, int)) != PKT_END) {
757 argint = va_arg(args, int);
758 PUT_32BIT(p, argint);
762 argchar = va_arg(args, unsigned char);
767 argp = va_arg(args, unsigned char *);
768 arglen = va_arg(args, int);
769 memcpy(p, argp, arglen);
773 argp = va_arg(args, unsigned char *);
774 arglen = strlen(argp);
775 PUT_32BIT(p, arglen);
776 memcpy(p + 4, argp, arglen);
780 bn = va_arg(args, Bignum);
781 p += ssh1_write_bignum(p, bn);
790 static int ssh_versioncmp(char *a, char *b) {
792 unsigned long av, bv;
794 av = strtoul(a, &ae, 10);
795 bv = strtoul(b, &be, 10);
796 if (av != bv) return (av < bv ? -1 : +1);
797 if (*ae == '.') ae++;
798 if (*be == '.') be++;
799 av = strtoul(ae, &ae, 10);
800 bv = strtoul(be, &be, 10);
801 if (av != bv) return (av < bv ? -1 : +1);
807 * Utility routine for putting an SSH-protocol `string' into a SHA
811 static void sha_string(SHA_State *s, void *str, int len) {
812 unsigned char lenblk[4];
813 PUT_32BIT(lenblk, len);
814 SHA_Bytes(s, lenblk, 4);
815 SHA_Bytes(s, str, len);
819 * SSH2 packet construction functions.
821 static void ssh2_pkt_ensure(int length) {
822 if (pktout.maxlen < length) {
823 pktout.maxlen = length + 256;
824 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
825 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
827 fatalbox("Out of memory");
830 static void ssh2_pkt_adddata(void *data, int len) {
831 pktout.length += len;
832 ssh2_pkt_ensure(pktout.length);
833 memcpy(pktout.data+pktout.length-len, data, len);
835 static void ssh2_pkt_addbyte(unsigned char byte) {
836 ssh2_pkt_adddata(&byte, 1);
838 static void ssh2_pkt_init(int pkt_type) {
840 ssh2_pkt_addbyte((unsigned char)pkt_type);
842 static void ssh2_pkt_addbool(unsigned char value) {
843 ssh2_pkt_adddata(&value, 1);
845 static void ssh2_pkt_adduint32(unsigned long value) {
848 ssh2_pkt_adddata(x, 4);
850 static void ssh2_pkt_addstring_start(void) {
851 ssh2_pkt_adduint32(0);
852 pktout.savedpos = pktout.length;
854 static void ssh2_pkt_addstring_str(char *data) {
855 ssh2_pkt_adddata(data, strlen(data));
856 PUT_32BIT(pktout.data + pktout.savedpos - 4,
857 pktout.length - pktout.savedpos);
859 static void ssh2_pkt_addstring_data(char *data, int len) {
860 ssh2_pkt_adddata(data, len);
861 PUT_32BIT(pktout.data + pktout.savedpos - 4,
862 pktout.length - pktout.savedpos);
864 static void ssh2_pkt_addstring(char *data) {
865 ssh2_pkt_addstring_start();
866 ssh2_pkt_addstring_str(data);
868 static char *ssh2_mpint_fmt(Bignum b, int *len) {
871 p = smalloc(n * 2 + 1);
873 fatalbox("out of memory");
875 for (i = 0; i < n; i++) {
876 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
877 p[i*2+2] = (b[n-i] ) & 0xFF;
880 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
882 memmove(p, p+i, n*2+1-i);
886 static void ssh2_pkt_addmp(Bignum b) {
889 p = ssh2_mpint_fmt(b, &len);
890 ssh2_pkt_addstring_start();
891 ssh2_pkt_addstring_data(p, len);
894 static void ssh2_pkt_send(void) {
895 int cipherblk, maclen, padding, i;
896 static unsigned long outgoing_sequence = 0;
899 * Compress packet payload.
902 debug(("Pre-compression payload:\r\n"));
903 for (i = 5; i < pktout.length; i++)
904 debug((" %02x", (unsigned char)pktout.data[i]));
908 unsigned char *newpayload;
910 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
911 &newpayload, &newlen)) {
913 ssh2_pkt_adddata(newpayload, newlen);
919 * Add padding. At least four bytes, and must also bring total
920 * length (minus MAC) up to a multiple of the block size.
922 cipherblk = cipher ? cipher->blksize : 8; /* block size */
923 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
925 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
926 maclen = csmac ? csmac->len : 0;
927 ssh2_pkt_ensure(pktout.length + padding + maclen);
928 pktout.data[4] = padding;
929 for (i = 0; i < padding; i++)
930 pktout.data[pktout.length + i] = random_byte();
931 PUT_32BIT(pktout.data, pktout.length + padding - 4);
933 csmac->generate(pktout.data, pktout.length + padding,
935 outgoing_sequence++; /* whether or not we MACed */
938 debug(("Sending packet len=%d\r\n", pktout.length+padding));
939 for (i = 0; i < pktout.length+padding; i++)
940 debug((" %02x", (unsigned char)pktout.data[i]));
945 cscipher->encrypt(pktout.data, pktout.length + padding);
947 sk_write(s, pktout.data, pktout.length + padding + maclen);
951 void bndebug(char *string, Bignum b) {
954 p = ssh2_mpint_fmt(b, &len);
955 debug(("%s", string));
956 for (i = 0; i < len; i++)
957 debug((" %02x", p[i]));
963 static void sha_mpint(SHA_State *s, Bignum b) {
966 p = ssh2_mpint_fmt(b, &len);
967 sha_string(s, p, len);
972 * SSH2 packet decode functions.
974 static unsigned long ssh2_pkt_getuint32(void) {
976 if (pktin.length - pktin.savedpos < 4)
977 return 0; /* arrgh, no way to decline (FIXME?) */
978 value = GET_32BIT(pktin.data+pktin.savedpos);
982 static void ssh2_pkt_getstring(char **p, int *length) {
984 if (pktin.length - pktin.savedpos < 4)
986 *length = GET_32BIT(pktin.data+pktin.savedpos);
988 if (pktin.length - pktin.savedpos < *length)
990 *p = pktin.data+pktin.savedpos;
991 pktin.savedpos += *length;
993 static Bignum ssh2_pkt_getmp(void) {
998 ssh2_pkt_getstring(&p, &length);
1002 bombout(("internal error: Can't handle negative mpints"));
1005 b = newbn((length+1)/2);
1006 for (i = 0; i < length; i++) {
1009 b[j/2+1] |= ((unsigned char)p[i]) << 8;
1011 b[j/2+1] |= ((unsigned char)p[i]);
1013 while (b[0] > 1 && b[b[0]] == 0) b[0]--;
1017 static int do_ssh_init(unsigned char c) {
1019 static char version[10];
1020 static char vstring[80];
1021 static char vlog[sizeof(vstring)+20];
1026 /* Search for the string "SSH-" in the input. */
1029 static const int transS[] = { 1, 2, 2, 1 };
1030 static const int transH[] = { 0, 0, 3, 0 };
1031 static const int transminus[] = { 0, 0, 0, -1 };
1032 if (c == 'S') i = transS[i];
1033 else if (c == 'H') i = transH[i];
1034 else if (c == '-') i = transminus[i];
1038 crReturn(1); /* get another character */
1041 strcpy(vstring, "SSH-");
1045 crReturn(1); /* get another char */
1046 if (vsp < vstring+sizeof(vstring)-1)
1052 } else if (i < sizeof(version)-1)
1059 ssh_agentfwd_enabled = FALSE;
1060 rdpkt2_state.incoming_sequence = 0;
1063 sprintf(vlog, "Server version: %s", vstring);
1064 vlog[strcspn(vlog, "\r\n")] = '\0';
1068 * Server version "1.99" means we can choose whether we use v1
1069 * or v2 protocol. Choice is based on cfg.sshprot.
1071 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1073 * This is a v2 server. Begin v2 protocol.
1075 char *verstring = "SSH-2.0-PuTTY";
1076 SHA_Init(&exhashbase);
1078 * Hash our version string and their version string.
1080 sha_string(&exhashbase, verstring, strlen(verstring));
1081 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1082 sprintf(vstring, "%s\n", verstring);
1083 sprintf(vlog, "We claim version: %s", verstring);
1085 logevent("Using SSH protocol version 2");
1086 sk_write(s, vstring, strlen(vstring));
1087 ssh_protocol = ssh2_protocol;
1089 s_rdpkt = ssh2_rdpkt;
1092 * This is a v1 server. Begin v1 protocol.
1094 sprintf(vstring, "SSH-%s-PuTTY\n",
1095 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1096 sprintf(vlog, "We claim version: %s", vstring);
1097 vlog[strcspn(vlog, "\r\n")] = '\0';
1099 logevent("Using SSH protocol version 1");
1100 sk_write(s, vstring, strlen(vstring));
1101 ssh_protocol = ssh1_protocol;
1103 s_rdpkt = ssh1_rdpkt;
1105 ssh_state = SSH_STATE_BEFORE_SIZE;
1110 static void ssh_gotdata(unsigned char *data, int datalen)
1115 * To begin with, feed the characters one by one to the
1116 * protocol initialisation / selection function do_ssh_init().
1117 * When that returns 0, we're done with the initial greeting
1118 * exchange and can move on to packet discipline.
1123 crReturnV; /* more data please */
1124 ret = do_ssh_init(*data);
1131 * We emerge from that loop when the initial negotiation is
1132 * over and we have selected an s_rdpkt function. Now pass
1133 * everything to s_rdpkt, and then pass the resulting packets
1134 * to the proper protocol handler.
1139 while (datalen > 0) {
1140 if ( s_rdpkt(&data, &datalen) == 0 ) {
1141 ssh_protocol(NULL, 0, 1);
1142 if (ssh_state == SSH_STATE_CLOSED) {
1152 static int ssh_receive(Socket skt, int urgent, char *data, int len) {
1154 /* A socket error has occurred. */
1155 ssh_state = SSH_STATE_CLOSED;
1158 connection_fatal(data);
1161 /* Connection has closed. */
1162 ssh_state = SSH_STATE_CLOSED;
1167 ssh_gotdata (data, len);
1168 if (ssh_state == SSH_STATE_CLOSED) {
1179 * Connect to specified host and port.
1180 * Returns an error message, or NULL on success.
1181 * Also places the canonical host name into `realhost'.
1183 static char *connect_to_host(char *host, int port, char **realhost)
1192 savedhost = smalloc(1+strlen(host));
1194 fatalbox("Out of memory");
1195 strcpy(savedhost, host);
1198 port = 22; /* default ssh port */
1211 addr = sk_namelookup(host, realhost);
1212 if ( (err = sk_addr_error(addr)) )
1222 s = sk_new(addr, port, 0, ssh_receive);
1223 if ( (err = sk_socket_error(s)) )
1227 sk_write(s, "connect ", 8);
1228 sk_write(s, FWhost, strlen(FWhost));
1231 sprintf(buf, " %d\n", FWport);
1232 sk_write(s, buf, strlen(buf));
1240 * Handle the key exchange and user authentication phases.
1242 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1245 unsigned char *rsabuf, *keystr1, *keystr2;
1246 unsigned char cookie[8];
1247 struct RSAKey servkey, hostkey;
1248 struct MD5Context md5c;
1249 static unsigned long supported_ciphers_mask, supported_auths_mask;
1250 static int tried_publickey;
1251 static unsigned char session_id[16];
1253 static char username[100];
1257 if (!ispkt) crWaitUntil(ispkt);
1259 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1260 bombout(("Public key packet not received"));
1264 logevent("Received public keys");
1266 memcpy(cookie, pktin.body, 8);
1268 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1269 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1272 * Log the host key fingerprint.
1276 logevent("Host key fingerprint is:");
1277 strcpy(logmsg, " ");
1278 hostkey.comment = NULL;
1279 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1284 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1285 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1288 MD5Update(&md5c, keystr2, hostkey.bytes);
1289 MD5Update(&md5c, keystr1, servkey.bytes);
1290 MD5Update(&md5c, pktin.body, 8);
1291 MD5Final(session_id, &md5c);
1293 for (i=0; i<32; i++)
1294 session_key[i] = random_byte();
1296 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1298 rsabuf = smalloc(len);
1300 fatalbox("Out of memory");
1303 * Verify the host key.
1307 * First format the key into a string.
1309 int len = rsastr_len(&hostkey);
1310 char fingerprint[100];
1311 char *keystr = smalloc(len);
1313 fatalbox("Out of memory");
1314 rsastr_fmt(keystr, &hostkey);
1315 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1316 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1320 for (i=0; i<32; i++) {
1321 rsabuf[i] = session_key[i];
1323 rsabuf[i] ^= session_id[i];
1326 if (hostkey.bytes > servkey.bytes) {
1327 rsaencrypt(rsabuf, 32, &servkey);
1328 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1330 rsaencrypt(rsabuf, 32, &hostkey);
1331 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1334 logevent("Encrypted session key");
1336 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
1337 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
1339 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1340 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1341 cipher_type = SSH_CIPHER_3DES;
1343 switch (cipher_type) {
1344 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1345 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1346 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1349 send_packet(SSH1_CMSG_SESSION_KEY,
1350 PKT_CHAR, cipher_type,
1351 PKT_DATA, cookie, 8,
1352 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1353 PKT_DATA, rsabuf, len,
1357 logevent("Trying to enable encryption...");
1361 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1362 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1364 cipher->sesskey(session_key);
1368 if (pktin.type != SSH1_SMSG_SUCCESS) {
1369 bombout(("Encryption not successfully enabled"));
1373 logevent("Successfully started encryption");
1379 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1380 c_write("login as: ", 10);
1383 crWaitUntil(!ispkt);
1384 while (inlen--) switch (c = *in++) {
1391 c_write("\b \b", 3);
1397 c_write("\b \b", 3);
1406 if (((c >= ' ' && c <= '~') ||
1407 ((unsigned char)c >= 160)) && pos < 40) {
1408 username[pos++] = c;
1415 username[strcspn(username, "\n\r")] = '\0';
1417 strncpy(username, cfg.username, 99);
1418 username[99] = '\0';
1421 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1423 char userlog[22+sizeof(username)];
1424 sprintf(userlog, "Sent username \"%s\"", username);
1426 if (flags & FLAG_INTERACTIVE &&
1427 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1428 strcat(userlog, "\r\n");
1429 c_write(userlog, strlen(userlog));
1436 tried_publickey = 0;
1438 while (pktin.type == SSH1_SMSG_FAILURE) {
1439 static char password[100];
1440 static char prompt[200];
1443 static int pwpkt_type;
1445 * Show password prompt, having first obtained it via a TIS
1446 * or CryptoCard exchange if we're doing TIS or CryptoCard
1449 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1450 if (agent_exists()) {
1452 * Attempt RSA authentication using Pageant.
1454 static unsigned char request[5], *response, *p;
1455 static int responselen;
1456 static int i, nkeys;
1457 static int authed = FALSE;
1460 logevent("Pageant is running. Requesting keys.");
1462 /* Request the keys held by the agent. */
1463 PUT_32BIT(request, 1);
1464 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1465 agent_query(request, 5, &r, &responselen);
1466 response = (unsigned char *)r;
1469 nkeys = GET_32BIT(p); p += 4;
1470 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1472 for (i = 0; i < nkeys; i++) {
1473 static struct RSAKey key;
1474 static Bignum challenge;
1475 static char *commentp;
1476 static int commentlen;
1478 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1481 p += ssh1_read_bignum(p, &key.exponent);
1482 p += ssh1_read_bignum(p, &key.modulus);
1483 commentlen = GET_32BIT(p); p += 4;
1484 commentp = p; p += commentlen;
1485 send_packet(SSH1_CMSG_AUTH_RSA,
1486 PKT_BIGNUM, key.modulus, PKT_END);
1488 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1489 logevent("Key refused");
1492 logevent("Received RSA challenge");
1493 ssh1_read_bignum(pktin.body, &challenge);
1495 char *agentreq, *q, *ret;
1497 len = 1 + 4; /* message type, bit count */
1498 len += ssh1_bignum_length(key.exponent);
1499 len += ssh1_bignum_length(key.modulus);
1500 len += ssh1_bignum_length(challenge);
1501 len += 16; /* session id */
1502 len += 4; /* response format */
1503 agentreq = smalloc(4 + len);
1504 PUT_32BIT(agentreq, len);
1506 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1507 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1509 q += ssh1_write_bignum(q, key.exponent);
1510 q += ssh1_write_bignum(q, key.modulus);
1511 q += ssh1_write_bignum(q, challenge);
1512 memcpy(q, session_id, 16); q += 16;
1513 PUT_32BIT(q, 1); /* response format */
1514 agent_query(agentreq, len+4, &ret, &retlen);
1517 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1518 logevent("Sending Pageant's response");
1519 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1520 PKT_DATA, ret+5, 16, PKT_END);
1523 if (pktin.type == SSH1_SMSG_SUCCESS) {
1524 logevent("Pageant's response accepted");
1525 if (flags & FLAG_VERBOSE) {
1526 c_write("Authenticated using RSA key \"",
1528 c_write(commentp, commentlen);
1529 c_write("\" from agent\r\n", 14);
1533 logevent("Pageant's response not accepted");
1535 logevent("Pageant failed to answer challenge");
1539 logevent("No reply received from Pageant");
1542 freebn(key.exponent);
1543 freebn(key.modulus);
1552 if (*cfg.keyfile && !tried_publickey)
1553 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1555 if (pktin.type == SSH1_SMSG_FAILURE &&
1557 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1558 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1559 logevent("Requested TIS authentication");
1560 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1562 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1563 logevent("TIS authentication declined");
1564 if (flags & FLAG_INTERACTIVE)
1565 c_write("TIS authentication refused.\r\n", 29);
1567 int challengelen = ((pktin.body[0] << 24) |
1568 (pktin.body[1] << 16) |
1569 (pktin.body[2] << 8) |
1571 logevent("Received TIS challenge");
1572 if (challengelen > sizeof(prompt)-1)
1573 challengelen = sizeof(prompt)-1; /* prevent overrun */
1574 memcpy(prompt, pktin.body+4, challengelen);
1575 prompt[challengelen] = '\0';
1578 if (pktin.type == SSH1_SMSG_FAILURE &&
1580 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1581 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1582 logevent("Requested CryptoCard authentication");
1583 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1585 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1586 logevent("CryptoCard authentication declined");
1587 c_write("CryptoCard authentication refused.\r\n", 29);
1589 int challengelen = ((pktin.body[0] << 24) |
1590 (pktin.body[1] << 16) |
1591 (pktin.body[2] << 8) |
1593 logevent("Received CryptoCard challenge");
1594 if (challengelen > sizeof(prompt)-1)
1595 challengelen = sizeof(prompt)-1; /* prevent overrun */
1596 memcpy(prompt, pktin.body+4, challengelen);
1597 strncpy(prompt + challengelen, "\r\nResponse : ",
1598 sizeof(prompt)-challengelen);
1599 prompt[sizeof(prompt)-1] = '\0';
1602 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1603 sprintf(prompt, "%.90s@%.90s's password: ",
1604 username, savedhost);
1606 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1607 char *comment = NULL;
1608 if (flags & FLAG_VERBOSE)
1609 c_write("Trying public key authentication.\r\n", 35);
1610 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1611 if (flags & FLAG_VERBOSE)
1612 c_write("No passphrase required.\r\n", 25);
1615 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1619 if (ssh_get_password) {
1620 if (!ssh_get_password(prompt, password, sizeof(password))) {
1622 * get_password failed to get a password (for
1623 * example because one was supplied on the command
1624 * line which has already failed to work).
1627 logevent("No more passwords to try");
1628 ssh_state = SSH_STATE_CLOSED;
1632 c_write(prompt, strlen(prompt));
1636 crWaitUntil(!ispkt);
1637 while (inlen--) switch (c = *in++) {
1654 if (((c >= ' ' && c <= '~') ||
1655 ((unsigned char)c >= 160)) && pos < sizeof(password))
1656 password[pos++] = c;
1664 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1666 * Try public key authentication with the specified
1669 static struct RSAKey pubkey;
1670 static Bignum challenge, response;
1672 static unsigned char buffer[32];
1674 tried_publickey = 1;
1675 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
1677 c_write("Couldn't load public key from ", 30);
1678 c_write(cfg.keyfile, strlen(cfg.keyfile));
1679 c_write(".\r\n", 3);
1680 continue; /* go and try password */
1683 c_write("Wrong passphrase.\r\n", 19);
1684 tried_publickey = 0;
1685 continue; /* try again */
1689 * Send a public key attempt.
1691 send_packet(SSH1_CMSG_AUTH_RSA,
1692 PKT_BIGNUM, pubkey.modulus, PKT_END);
1695 if (pktin.type == SSH1_SMSG_FAILURE) {
1696 c_write("Server refused our public key.\r\n", 32);
1697 continue; /* go and try password */
1699 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1700 bombout(("Bizarre response to offer of public key"));
1703 ssh1_read_bignum(pktin.body, &challenge);
1704 response = rsadecrypt(challenge, &pubkey);
1705 freebn(pubkey.private_exponent); /* burn the evidence */
1707 for (i = 0; i < 32; i += 2) {
1708 buffer[i] = response[16-i/2] >> 8;
1709 buffer[i+1] = response[16-i/2] & 0xFF;
1713 MD5Update(&md5c, buffer, 32);
1714 MD5Update(&md5c, session_id, 16);
1715 MD5Final(buffer, &md5c);
1717 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1718 PKT_DATA, buffer, 16, PKT_END);
1721 if (pktin.type == SSH1_SMSG_FAILURE) {
1722 if (flags & FLAG_VERBOSE)
1723 c_write("Failed to authenticate with our public key.\r\n",
1725 continue; /* go and try password */
1726 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1727 bombout(("Bizarre response to RSA authentication response"));
1731 break; /* we're through! */
1733 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1735 logevent("Sent password");
1736 memset(password, 0, strlen(password));
1738 if (pktin.type == SSH1_SMSG_FAILURE) {
1739 if (flags & FLAG_VERBOSE)
1740 c_write("Access denied\r\n", 15);
1741 logevent("Authentication refused");
1742 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1743 logevent("Received disconnect request");
1744 ssh_state = SSH_STATE_CLOSED;
1746 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1747 bombout(("Strange packet received, type %d", pktin.type));
1752 logevent("Authentication successful");
1757 void sshfwd_close(struct ssh_channel *c) {
1759 if (ssh_version == 1) {
1760 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1762 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1763 ssh2_pkt_adduint32(c->remoteid);
1767 if (c->type == CHAN_X11) {
1769 logevent("X11 connection terminated");
1774 void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
1775 if (ssh_version == 1) {
1776 send_packet(SSH1_MSG_CHANNEL_DATA,
1777 PKT_INT, c->remoteid,
1782 ssh2_add_channel_data(c, buf, len);
1787 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1792 while (!do_ssh1_login(in, inlen, ispkt)) {
1795 if (ssh_state == SSH_STATE_CLOSED)
1798 if (cfg.agentfwd && agent_exists()) {
1799 logevent("Requesting agent forwarding");
1800 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1801 do { crReturnV; } while (!ispkt);
1802 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1803 bombout(("Protocol confusion"));
1805 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1806 logevent("Agent forwarding refused");
1808 logevent("Agent forwarding enabled");
1809 ssh_agentfwd_enabled = TRUE;
1813 if (cfg.x11_forward) {
1814 char proto[20], data[64];
1815 logevent("Requesting X11 forwarding");
1816 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
1817 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
1818 PKT_STR, proto, PKT_STR, data,
1821 do { crReturnV; } while (!ispkt);
1822 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1823 bombout(("Protocol confusion"));
1825 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1826 logevent("X11 forwarding refused");
1828 logevent("X11 forwarding enabled");
1829 ssh_X11_fwd_enabled = TRUE;
1834 send_packet(SSH1_CMSG_REQUEST_PTY,
1835 PKT_STR, cfg.termtype,
1836 PKT_INT, rows, PKT_INT, cols,
1837 PKT_INT, 0, PKT_INT, 0,
1840 ssh_state = SSH_STATE_INTERMED;
1841 do { crReturnV; } while (!ispkt);
1842 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1843 bombout(("Protocol confusion"));
1845 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1846 c_write("Server refused to allocate pty\r\n", 32);
1847 ssh_editing = ssh_echoing = 1;
1849 logevent("Allocated pty");
1851 ssh_editing = ssh_echoing = 1;
1854 if (cfg.compression) {
1855 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1856 do { crReturnV; } while (!ispkt);
1857 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1858 bombout(("Protocol confusion"));
1860 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1861 c_write("Server refused to compress\r\n", 32);
1863 logevent("Started compression");
1864 ssh1_compressing = TRUE;
1865 zlib_compress_init();
1866 zlib_decompress_init();
1869 if (*cfg.remote_cmd)
1870 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1872 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1873 logevent("Started session");
1875 ssh_state = SSH_STATE_SESSION;
1879 ssh_special(TS_EOF);
1881 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
1883 ssh_channels = newtree234(ssh_channelcmp);
1887 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1888 pktin.type == SSH1_SMSG_STDERR_DATA) {
1889 long len = GET_32BIT(pktin.body);
1890 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1892 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1893 ssh_state = SSH_STATE_CLOSED;
1894 logevent("Received disconnect request");
1896 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
1897 /* Remote side is trying to open a channel to talk to our
1898 * X-Server. Give them back a local channel number. */
1900 struct ssh_channel *c, *d;
1903 logevent("Received X11 connect request");
1904 /* Refuse if X11 forwarding is disabled. */
1905 if (!ssh_X11_fwd_enabled) {
1906 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1907 PKT_INT, GET_32BIT(pktin.body),
1909 logevent("Rejected X11 connect request");
1911 c = smalloc(sizeof(struct ssh_channel));
1913 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
1914 logevent("opening X11 forward connection failed");
1916 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1917 PKT_INT, GET_32BIT(pktin.body),
1920 logevent("opening X11 forward connection succeeded");
1921 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
1923 break; /* found a free number */
1926 c->remoteid = GET_32BIT(pktin.body);
1929 c->type = CHAN_X11; /* identify channel type */
1930 add234(ssh_channels, c);
1931 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1932 PKT_INT, c->remoteid, PKT_INT, c->localid,
1934 logevent("Opened X11 forward channel");
1937 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1938 /* Remote side is trying to open a channel to talk to our
1939 * agent. Give them back a local channel number. */
1941 struct ssh_channel *c;
1944 /* Refuse if agent forwarding is disabled. */
1945 if (!ssh_agentfwd_enabled) {
1946 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1947 PKT_INT, GET_32BIT(pktin.body),
1951 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1953 break; /* found a free number */
1956 c = smalloc(sizeof(struct ssh_channel));
1957 c->remoteid = GET_32BIT(pktin.body);
1960 c->type = CHAN_AGENT; /* identify channel type */
1961 c->u.a.lensofar = 0;
1962 add234(ssh_channels, c);
1963 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1964 PKT_INT, c->remoteid, PKT_INT, c->localid,
1967 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1968 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1969 /* Remote side closes a channel. */
1970 unsigned i = GET_32BIT(pktin.body);
1971 struct ssh_channel *c;
1972 c = find234(ssh_channels, &i, ssh_channelfind);
1975 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1976 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1977 if ((c->closes == 0) && (c->type == CHAN_X11)) {
1978 logevent("X11 connection closed");
1979 assert(c->u.x11.s != NULL);
1980 x11_close(c->u.x11.s);
1983 c->closes |= closetype;
1984 if (c->closes == 3) {
1985 del234(ssh_channels, c);
1989 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1990 /* Data sent down one of our channels. */
1991 int i = GET_32BIT(pktin.body);
1992 int len = GET_32BIT(pktin.body+4);
1993 unsigned char *p = pktin.body+8;
1994 struct ssh_channel *c;
1995 c = find234(ssh_channels, &i, ssh_channelfind);
1999 x11_send(c->u.x11.s, p, len);
2002 /* Data for an agent message. Buffer it. */
2004 if (c->u.a.lensofar < 4) {
2005 int l = min(4 - c->u.a.lensofar, len);
2006 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2007 p += l; len -= l; c->u.a.lensofar += l;
2009 if (c->u.a.lensofar == 4) {
2010 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
2011 c->u.a.message = smalloc(c->u.a.totallen);
2012 memcpy(c->u.a.message, c->u.a.msglen, 4);
2014 if (c->u.a.lensofar >= 4 && len > 0) {
2015 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2016 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2017 p += l; len -= l; c->u.a.lensofar += l;
2019 if (c->u.a.lensofar == c->u.a.totallen) {
2020 void *reply, *sentreply;
2022 agent_query(c->u.a.message, c->u.a.totallen,
2027 /* Fake SSH_AGENT_FAILURE. */
2028 sentreply = "\0\0\0\1\5";
2031 send_packet(SSH1_MSG_CHANNEL_DATA,
2032 PKT_INT, c->remoteid,
2034 PKT_DATA, sentreply, replylen,
2038 sfree(c->u.a.message);
2039 c->u.a.lensofar = 0;
2045 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2046 /* may be from EXEC_SHELL on some servers */
2047 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2048 /* may be from EXEC_SHELL on some servers
2049 * if no pty is available or in other odd cases. Ignore */
2050 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2051 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2053 bombout(("Strange packet received: type %d", pktin.type));
2058 int len = min(inlen, 512);
2059 send_packet(SSH1_CMSG_STDIN_DATA,
2060 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2071 * Utility routine for decoding comma-separated strings in KEXINIT.
2073 static int in_commasep_string(char *needle, char *haystack, int haylen) {
2074 int needlen = strlen(needle);
2077 * Is it at the start of the string?
2079 if (haylen >= needlen && /* haystack is long enough */
2080 !memcmp(needle, haystack, needlen) && /* initial match */
2081 (haylen == needlen || haystack[needlen] == ',')
2082 /* either , or EOS follows */
2086 * If not, search for the next comma and resume after that.
2087 * If no comma found, terminate.
2089 while (haylen > 0 && *haystack != ',')
2090 haylen--, haystack++;
2093 haylen--, haystack++; /* skip over comma itself */
2098 * SSH2 key creation method.
2100 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
2102 /* First 20 bytes. */
2105 SHA_Bytes(&s, H, 20);
2106 SHA_Bytes(&s, &chr, 1);
2107 SHA_Bytes(&s, sessid, 20);
2108 SHA_Final(&s, keyspace);
2109 /* Next 20 bytes. */
2112 SHA_Bytes(&s, H, 20);
2113 SHA_Bytes(&s, keyspace, 20);
2114 SHA_Final(&s, keyspace+20);
2118 * Handle the SSH2 transport layer.
2120 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2124 static Bignum e, f, K;
2125 static const struct ssh_mac **maclist;
2127 static const struct ssh_cipher *cscipher_tobe = NULL;
2128 static const struct ssh_cipher *sccipher_tobe = NULL;
2129 static const struct ssh_mac *csmac_tobe = NULL;
2130 static const struct ssh_mac *scmac_tobe = NULL;
2131 static const struct ssh_compress *cscomp_tobe = NULL;
2132 static const struct ssh_compress *sccomp_tobe = NULL;
2133 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2134 static int hostkeylen, siglen;
2135 static void *hkey; /* actual host key */
2136 static unsigned char exchange_hash[20];
2137 static unsigned char first_exchange_hash[20];
2138 static unsigned char keyspace[40];
2139 static const struct ssh_cipher *preferred_cipher;
2140 static const struct ssh_compress *preferred_comp;
2141 static int first_kex;
2148 * Set up the preferred cipher and compression.
2150 if (cfg.cipher == CIPHER_BLOWFISH) {
2151 preferred_cipher = &ssh_blowfish_ssh2;
2152 } else if (cfg.cipher == CIPHER_DES) {
2153 logevent("Single DES not supported in SSH2; using 3DES");
2154 preferred_cipher = &ssh_3des_ssh2;
2155 } else if (cfg.cipher == CIPHER_3DES) {
2156 preferred_cipher = &ssh_3des_ssh2;
2158 /* Shouldn't happen, but we do want to initialise to _something_. */
2159 preferred_cipher = &ssh_3des_ssh2;
2161 if (cfg.compression)
2162 preferred_comp = &ssh_zlib;
2164 preferred_comp = &ssh_comp_none;
2167 * Be prepared to work around the buggy MAC problem.
2170 maclist = buggymacs, nmacs = lenof(buggymacs);
2172 maclist = macs, nmacs = lenof(macs);
2176 * Construct and send our key exchange packet.
2178 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2179 for (i = 0; i < 16; i++)
2180 ssh2_pkt_addbyte((unsigned char)random_byte());
2181 /* List key exchange algorithms. */
2182 ssh2_pkt_addstring_start();
2183 for (i = 0; i < lenof(kex_algs); i++) {
2184 ssh2_pkt_addstring_str(kex_algs[i]->name);
2185 if (i < lenof(kex_algs)-1)
2186 ssh2_pkt_addstring_str(",");
2188 /* List server host key algorithms. */
2189 ssh2_pkt_addstring_start();
2190 for (i = 0; i < lenof(hostkey_algs); i++) {
2191 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2192 if (i < lenof(hostkey_algs)-1)
2193 ssh2_pkt_addstring_str(",");
2195 /* List client->server encryption algorithms. */
2196 ssh2_pkt_addstring_start();
2197 for (i = 0; i < lenof(ciphers)+1; i++) {
2198 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2199 ssh2_pkt_addstring_str(c->name);
2200 if (i < lenof(ciphers))
2201 ssh2_pkt_addstring_str(",");
2203 /* List server->client encryption algorithms. */
2204 ssh2_pkt_addstring_start();
2205 for (i = 0; i < lenof(ciphers)+1; i++) {
2206 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2207 ssh2_pkt_addstring_str(c->name);
2208 if (i < lenof(ciphers))
2209 ssh2_pkt_addstring_str(",");
2211 /* List client->server MAC algorithms. */
2212 ssh2_pkt_addstring_start();
2213 for (i = 0; i < nmacs; i++) {
2214 ssh2_pkt_addstring_str(maclist[i]->name);
2216 ssh2_pkt_addstring_str(",");
2218 /* List server->client MAC algorithms. */
2219 ssh2_pkt_addstring_start();
2220 for (i = 0; i < nmacs; i++) {
2221 ssh2_pkt_addstring_str(maclist[i]->name);
2223 ssh2_pkt_addstring_str(",");
2225 /* List client->server compression algorithms. */
2226 ssh2_pkt_addstring_start();
2227 for (i = 0; i < lenof(compressions)+1; i++) {
2228 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2229 ssh2_pkt_addstring_str(c->name);
2230 if (i < lenof(compressions))
2231 ssh2_pkt_addstring_str(",");
2233 /* List server->client compression algorithms. */
2234 ssh2_pkt_addstring_start();
2235 for (i = 0; i < lenof(compressions)+1; i++) {
2236 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2237 ssh2_pkt_addstring_str(c->name);
2238 if (i < lenof(compressions))
2239 ssh2_pkt_addstring_str(",");
2241 /* List client->server languages. Empty list. */
2242 ssh2_pkt_addstring_start();
2243 /* List server->client languages. Empty list. */
2244 ssh2_pkt_addstring_start();
2245 /* First KEX packet does _not_ follow, because we're not that brave. */
2246 ssh2_pkt_addbool(FALSE);
2248 ssh2_pkt_adduint32(0);
2250 exhash = exhashbase;
2251 sha_string(&exhash, pktout.data+5, pktout.length-5);
2255 if (!ispkt) crWaitUntil(ispkt);
2256 sha_string(&exhash, pktin.data+5, pktin.length-5);
2259 * Now examine the other side's KEXINIT to see what we're up
2262 if (pktin.type != SSH2_MSG_KEXINIT) {
2263 bombout(("expected key exchange packet from server"));
2266 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2267 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2268 pktin.savedpos += 16; /* skip garbage cookie */
2269 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2270 for (i = 0; i < lenof(kex_algs); i++) {
2271 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2276 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2277 for (i = 0; i < lenof(hostkey_algs); i++) {
2278 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2279 hostkey = hostkey_algs[i];
2283 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2284 for (i = 0; i < lenof(ciphers)+1; i++) {
2285 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2286 if (in_commasep_string(c->name, str, len)) {
2291 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2292 for (i = 0; i < lenof(ciphers)+1; i++) {
2293 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2294 if (in_commasep_string(c->name, str, len)) {
2299 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2300 for (i = 0; i < nmacs; i++) {
2301 if (in_commasep_string(maclist[i]->name, str, len)) {
2302 csmac_tobe = maclist[i];
2306 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2307 for (i = 0; i < nmacs; i++) {
2308 if (in_commasep_string(maclist[i]->name, str, len)) {
2309 scmac_tobe = maclist[i];
2313 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2314 for (i = 0; i < lenof(compressions)+1; i++) {
2315 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2316 if (in_commasep_string(c->name, str, len)) {
2321 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2322 for (i = 0; i < lenof(compressions)+1; i++) {
2323 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2324 if (in_commasep_string(c->name, str, len)) {
2331 * Currently we only support Diffie-Hellman and DSS, so let's
2332 * bomb out if those aren't selected.
2334 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2335 bombout(("internal fault: chaos in SSH 2 transport layer"));
2340 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2343 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2348 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
2349 bombout(("expected key exchange packet from server"));
2352 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2353 f = ssh2_pkt_getmp();
2354 ssh2_pkt_getstring(&sigdata, &siglen);
2358 sha_string(&exhash, hostkeydata, hostkeylen);
2359 sha_mpint(&exhash, e);
2360 sha_mpint(&exhash, f);
2361 sha_mpint(&exhash, K);
2362 SHA_Final(&exhash, exchange_hash);
2365 debug(("Exchange hash is:\r\n"));
2366 for (i = 0; i < 20; i++)
2367 debug((" %02x", exchange_hash[i]));
2371 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2372 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2373 bombout(("Server failed host key check"));
2378 * Expect SSH2_MSG_NEWKEYS from server.
2381 if (pktin.type != SSH2_MSG_NEWKEYS) {
2382 bombout(("expected new-keys packet from server"));
2387 * Authenticate remote host: verify host key. (We've already
2388 * checked the signature of the exchange hash.)
2390 keystr = hostkey->fmtkey(hkey);
2391 fingerprint = hostkey->fingerprint(hkey);
2392 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2393 keystr, fingerprint);
2394 if (first_kex) { /* don't bother logging this in rekeys */
2395 logevent("Host key fingerprint is:");
2396 logevent(fingerprint);
2400 hostkey->freekey(hkey);
2403 * Send SSH2_MSG_NEWKEYS.
2405 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2409 * Create and initialise session keys.
2411 cscipher = cscipher_tobe;
2412 sccipher = sccipher_tobe;
2415 cscomp = cscomp_tobe;
2416 sccomp = sccomp_tobe;
2417 cscomp->compress_init();
2418 sccomp->decompress_init();
2420 * Set IVs after keys. Here we use the exchange hash from the
2421 * _first_ key exchange.
2424 memcpy(first_exchange_hash, exchange_hash, sizeof(exchange_hash));
2425 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'C', keyspace);
2426 cscipher->setcskey(keyspace);
2427 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'D', keyspace);
2428 sccipher->setsckey(keyspace);
2429 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'A', keyspace);
2430 cscipher->setcsiv(keyspace);
2431 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'B', keyspace);
2432 sccipher->setsciv(keyspace);
2433 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'E', keyspace);
2434 csmac->setcskey(keyspace);
2435 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'F', keyspace);
2436 scmac->setsckey(keyspace);
2439 * If this is the first key exchange phase, we must pass the
2440 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2441 * wants to see it but because it will need time to initialise
2442 * itself before it sees an actual packet. In subsequent key
2443 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2444 * it would only confuse the layer above.
2452 * Now we're encrypting. Begin returning 1 to the protocol main
2453 * function so that other things can run on top of the
2454 * transport. If we ever see a KEXINIT, we must go back to the
2459 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2460 logevent("Server initiated key re-exchange");
2461 goto begin_key_exchange;
2467 * Add data to an SSH2 channel output buffer.
2469 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2470 if (c->v2.outbufsize <
2471 c->v2.outbuflen + len) {
2473 c->v2.outbuflen + len + 1024;
2474 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2477 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2479 c->v2.outbuflen += len;
2483 * Attempt to send data on an SSH2 channel.
2485 static void ssh2_try_send(struct ssh_channel *c) {
2486 while (c->v2.remwindow > 0 &&
2487 c->v2.outbuflen > 0) {
2488 unsigned len = c->v2.remwindow;
2489 if (len > c->v2.outbuflen)
2490 len = c->v2.outbuflen;
2491 if (len > c->v2.remmaxpkt)
2492 len = c->v2.remmaxpkt;
2493 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2494 ssh2_pkt_adduint32(c->remoteid);
2495 ssh2_pkt_addstring_start();
2496 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2498 c->v2.outbuflen -= len;
2499 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2501 c->v2.remwindow -= len;
2506 * Handle the SSH2 userauth and connection layers.
2508 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2510 static unsigned long remote_winsize;
2511 static unsigned long remote_maxpkt;
2516 * Request userauth protocol, and await a response to it.
2518 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2519 ssh2_pkt_addstring("ssh-userauth");
2521 crWaitUntilV(ispkt);
2522 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2523 bombout(("Server refused user authentication protocol"));
2528 * FIXME: currently we support only password authentication.
2529 * (This places us technically in violation of the SSH2 spec.
2530 * We must fix this.)
2534 * Get a username and a password.
2536 static char username[100];
2537 static char password[100];
2541 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2542 c_write("login as: ", 10);
2545 crWaitUntilV(!ispkt);
2546 while (inlen--) switch (c = *in++) {
2553 c_write("\b \b", 3);
2559 c_write("\b \b", 3);
2568 if (((c >= ' ' && c <= '~') ||
2569 ((unsigned char)c >= 160)) && pos < 40) {
2570 username[pos++] = c;
2577 username[strcspn(username, "\n\r")] = '\0';
2580 strncpy(username, cfg.username, 99);
2581 username[99] = '\0';
2582 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2583 sprintf(stuff, "Using username \"%s\".\r\n", username);
2584 c_write(stuff, strlen(stuff));
2588 if (ssh_get_password) {
2590 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
2591 if (!ssh_get_password(prompt, password, sizeof(password))) {
2593 * get_password failed to get a password (for
2594 * example because one was supplied on the command
2595 * line which has already failed to work).
2598 logevent("No more passwords to try");
2599 ssh_state = SSH_STATE_CLOSED;
2603 c_write("password: ", 10);
2608 crWaitUntilV(!ispkt);
2609 while (inlen--) switch (c = *in++) {
2626 if (((c >= ' ' && c <= '~') ||
2627 ((unsigned char)c >= 160)) && pos < 40)
2628 password[pos++] = c;
2635 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2636 ssh2_pkt_addstring(username);
2637 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2638 ssh2_pkt_addstring("password");
2639 ssh2_pkt_addbool(FALSE);
2640 ssh2_pkt_addstring(password);
2643 crWaitUntilV(ispkt);
2644 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2645 c_write("Access denied\r\n", 15);
2646 logevent("Authentication refused");
2652 * Now we're authenticated for the connection protocol. The
2653 * connection protocol will automatically have started at this
2654 * point; there's no need to send SERVICE_REQUEST.
2658 * So now create a channel with a session in it.
2660 mainchan = smalloc(sizeof(struct ssh_channel));
2661 mainchan->localid = 100; /* as good as any */
2662 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2663 ssh2_pkt_addstring("session");
2664 ssh2_pkt_adduint32(mainchan->localid);
2665 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2666 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2668 crWaitUntilV(ispkt);
2669 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
2670 bombout(("Server refused to open a session"));
2672 /* FIXME: error data comes back in FAILURE packet */
2674 if (ssh2_pkt_getuint32() != mainchan->localid) {
2675 bombout(("Server's channel confirmation cited wrong channel"));
2678 mainchan->remoteid = ssh2_pkt_getuint32();
2679 mainchan->type = CHAN_MAINSESSION;
2680 mainchan->closes = 0;
2681 mainchan->v2.remwindow = ssh2_pkt_getuint32();
2682 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
2683 mainchan->v2.outbuffer = NULL;
2684 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
2685 ssh_channels = newtree234(ssh_channelcmp);
2686 add234(ssh_channels, mainchan);
2687 logevent("Opened channel for session");
2690 * Potentially enable X11 forwarding.
2692 if (cfg.x11_forward) {
2693 char proto[20], data[64];
2694 logevent("Requesting X11 forwarding");
2695 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2696 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2697 ssh2_pkt_adduint32(mainchan->remoteid);
2698 ssh2_pkt_addstring("x11-req");
2699 ssh2_pkt_addbool(1); /* want reply */
2700 ssh2_pkt_addbool(0); /* many connections */
2701 ssh2_pkt_addstring(proto);
2702 ssh2_pkt_addstring(data);
2703 ssh2_pkt_adduint32(0); /* screen number */
2707 crWaitUntilV(ispkt);
2708 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2709 unsigned i = ssh2_pkt_getuint32();
2710 struct ssh_channel *c;
2711 c = find234(ssh_channels, &i, ssh_channelfind);
2713 continue; /* nonexistent channel */
2714 c->v2.remwindow += ssh2_pkt_getuint32();
2716 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2718 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2719 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2720 bombout(("Server got confused by X11 forwarding request"));
2723 logevent("X11 forwarding refused");
2725 logevent("X11 forwarding enabled");
2726 ssh_X11_fwd_enabled = TRUE;
2731 * Now allocate a pty for the session.
2734 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2735 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2736 ssh2_pkt_addstring("pty-req");
2737 ssh2_pkt_addbool(1); /* want reply */
2738 ssh2_pkt_addstring(cfg.termtype);
2739 ssh2_pkt_adduint32(cols);
2740 ssh2_pkt_adduint32(rows);
2741 ssh2_pkt_adduint32(0); /* pixel width */
2742 ssh2_pkt_adduint32(0); /* pixel height */
2743 ssh2_pkt_addstring_start();
2744 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2746 ssh_state = SSH_STATE_INTERMED;
2749 crWaitUntilV(ispkt);
2750 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2751 unsigned i = ssh2_pkt_getuint32();
2752 struct ssh_channel *c;
2753 c = find234(ssh_channels, &i, ssh_channelfind);
2755 continue; /* nonexistent channel */
2756 c->v2.remwindow += ssh2_pkt_getuint32();
2758 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2760 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2761 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2762 bombout(("Server got confused by pty request"));
2765 c_write("Server refused to allocate pty\r\n", 32);
2766 ssh_editing = ssh_echoing = 1;
2768 logevent("Allocated pty");
2771 ssh_editing = ssh_echoing = 1;
2775 * Start a shell or a remote command.
2777 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2778 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2779 if (*cfg.remote_cmd) {
2780 ssh2_pkt_addstring("exec");
2781 ssh2_pkt_addbool(1); /* want reply */
2782 ssh2_pkt_addstring(cfg.remote_cmd);
2784 ssh2_pkt_addstring("shell");
2785 ssh2_pkt_addbool(1); /* want reply */
2789 crWaitUntilV(ispkt);
2790 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2791 unsigned i = ssh2_pkt_getuint32();
2792 struct ssh_channel *c;
2793 c = find234(ssh_channels, &i, ssh_channelfind);
2795 continue; /* nonexistent channel */
2796 c->v2.remwindow += ssh2_pkt_getuint32();
2798 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2799 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2800 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2801 bombout(("Server got confused by shell/command request"));
2804 bombout(("Server refused to start a shell/command"));
2807 logevent("Started a shell/command");
2810 ssh_state = SSH_STATE_SESSION;
2814 ssh_special(TS_EOF);
2819 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2822 static int try_send;
2826 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2827 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2830 unsigned i = ssh2_pkt_getuint32();
2831 struct ssh_channel *c;
2832 c = find234(ssh_channels, &i, ssh_channelfind);
2834 continue; /* nonexistent channel */
2835 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2836 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2837 continue; /* extended but not stderr */
2838 ssh2_pkt_getstring(&data, &length);
2841 case CHAN_MAINSESSION:
2842 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2846 x11_send(c->u.x11.s, data, length);
2850 * Enlarge the window again at the remote
2851 * side, just in case it ever runs down and
2852 * they fail to send us any more data.
2854 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2855 ssh2_pkt_adduint32(c->remoteid);
2856 ssh2_pkt_adduint32(length);
2859 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2860 ssh_state = SSH_STATE_CLOSED;
2861 logevent("Received disconnect message");
2863 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2864 continue; /* exit status et al; ignore (FIXME?) */
2865 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2866 unsigned i = ssh2_pkt_getuint32();
2867 struct ssh_channel *c;
2869 c = find234(ssh_channels, &i, ssh_channelfind);
2871 continue; /* nonexistent channel */
2873 if (c->type == CHAN_X11) {
2875 * Remote EOF on an X11 channel means we should
2876 * wrap up and close the channel ourselves.
2878 x11_close(c->u.x11.s);
2881 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2882 unsigned i = ssh2_pkt_getuint32();
2883 struct ssh_channel *c;
2886 c = find234(ssh_channels, &i, ssh_channelfind);
2888 continue; /* nonexistent channel */
2889 if (c->closes == 0) {
2890 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2891 ssh2_pkt_adduint32(c->remoteid);
2894 /* Do pre-close processing on the channel. */
2896 case CHAN_MAINSESSION:
2897 break; /* nothing to see here, move along */
2901 del234(ssh_channels, c);
2902 sfree(c->v2.outbuffer);
2906 * See if that was the last channel left open.
2908 c = first234(ssh_channels, &e);
2910 logevent("All channels closed. Disconnecting");
2911 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2912 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
2913 ssh2_pkt_addstring("All open channels closed");
2914 ssh2_pkt_addstring("en"); /* language tag */
2916 ssh_state = SSH_STATE_CLOSED;
2919 continue; /* remote sends close; ignore (FIXME) */
2920 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2921 unsigned i = ssh2_pkt_getuint32();
2922 struct ssh_channel *c;
2923 c = find234(ssh_channels, &i, ssh_channelfind);
2925 continue; /* nonexistent channel */
2926 mainchan->v2.remwindow += ssh2_pkt_getuint32();
2928 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
2932 struct ssh_channel *c;
2933 ssh2_pkt_getstring(&type, &typelen);
2934 c = smalloc(sizeof(struct ssh_channel));
2936 if (typelen == 3 && !memcmp(type, "x11", 3)) {
2937 if (!ssh_X11_fwd_enabled)
2938 error = "X11 forwarding is not enabled";
2939 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
2940 error = "Unable to open an X11 connection";
2945 error = "Unsupported channel type requested";
2948 c->remoteid = ssh2_pkt_getuint32();
2950 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
2951 ssh2_pkt_adduint32(c->remoteid);
2952 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
2953 ssh2_pkt_addstring(error);
2954 ssh2_pkt_addstring("en"); /* language tag */
2958 struct ssh_channel *d;
2962 for (i=1, d = first234(ssh_channels, &e); d;
2965 break; /* found a free number */
2970 c->v2.remwindow = ssh2_pkt_getuint32();
2971 c->v2.remmaxpkt = ssh2_pkt_getuint32();
2972 c->v2.outbuffer = NULL;
2973 c->v2.outbuflen = c->v2.outbufsize = 0;
2974 add234(ssh_channels, c);
2975 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
2976 ssh2_pkt_adduint32(c->remoteid);
2977 ssh2_pkt_adduint32(c->localid);
2978 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2979 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2983 bombout(("Strange packet received: type %d", pktin.type));
2988 * We have spare data. Add it to the channel buffer.
2990 ssh2_add_channel_data(mainchan, in, inlen);
2995 struct ssh_channel *c;
2997 * Try to send data on all channels if we can.
2999 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3008 * Handle the top-level SSH2 protocol.
3010 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3012 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3014 do_ssh2_authconn(in, inlen, ispkt);
3018 * Called to set up the connection.
3020 * Returns an error message, or NULL on success.
3022 static char *ssh_init (char *host, int port, char **realhost) {
3026 if(crypto_startup() == 0)
3027 return "Microsoft high encryption pack not installed!";
3034 p = connect_to_host(host, port, realhost);
3042 * Called to send data down the Telnet connection.
3044 static void ssh_send (char *buf, int len) {
3045 if (s == NULL || ssh_protocol == NULL)
3048 ssh_protocol(buf, len, 0);
3052 * Called to set the size of the window from SSH's POV.
3054 static void ssh_size(void) {
3055 switch (ssh_state) {
3056 case SSH_STATE_BEFORE_SIZE:
3057 case SSH_STATE_PREPACKET:
3058 case SSH_STATE_CLOSED:
3059 break; /* do nothing */
3060 case SSH_STATE_INTERMED:
3061 size_needed = TRUE; /* buffer for later */
3063 case SSH_STATE_SESSION:
3065 if (ssh_version == 1) {
3066 send_packet(SSH1_CMSG_WINDOW_SIZE,
3067 PKT_INT, rows, PKT_INT, cols,
3068 PKT_INT, 0, PKT_INT, 0, PKT_END);
3070 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3071 ssh2_pkt_adduint32(mainchan->remoteid);
3072 ssh2_pkt_addstring("window-change");
3073 ssh2_pkt_addbool(0);
3074 ssh2_pkt_adduint32(cols);
3075 ssh2_pkt_adduint32(rows);
3076 ssh2_pkt_adduint32(0);
3077 ssh2_pkt_adduint32(0);
3086 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3087 * can send an EOF and collect resulting output (e.g. `plink
3090 static void ssh_special (Telnet_Special code) {
3091 if (code == TS_EOF) {
3092 if (ssh_state != SSH_STATE_SESSION) {
3094 * Buffer the EOF in case we are pre-SESSION, so we can
3095 * send it as soon as we reach SESSION.
3101 if (ssh_version == 1) {
3102 send_packet(SSH1_CMSG_EOF, PKT_END);
3104 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
3105 ssh2_pkt_adduint32(mainchan->remoteid);
3108 logevent("Sent EOF message");
3109 } else if (code == TS_PING) {
3110 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3112 if (ssh_version == 1) {
3113 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3115 ssh2_pkt_init(SSH2_MSG_IGNORE);
3116 ssh2_pkt_addstring_start();
3124 static Socket ssh_socket(void) { return s; }
3126 static int ssh_sendok(void) { return ssh_send_ok; }
3128 static int ssh_ldisc(int option) {
3129 if (option == LD_ECHO) return ssh_echoing;
3130 if (option == LD_EDIT) return ssh_editing;
3134 Backend ssh_backend = {