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 : 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_KEX_DH_GEX_REQUEST 30 /* 0x1e */
91 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
92 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
93 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
94 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
95 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
96 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
97 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
98 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
99 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
100 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
101 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
102 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
103 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
104 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
105 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
106 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
107 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
108 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
109 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
110 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
111 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
112 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
113 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
127 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
128 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
129 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
130 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
132 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
134 #define GET_32BIT(cp) \
135 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
136 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
137 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
138 ((unsigned long)(unsigned char)(cp)[3]))
140 #define PUT_32BIT(cp, value) { \
141 (cp)[0] = (unsigned char)((value) >> 24); \
142 (cp)[1] = (unsigned char)((value) >> 16); \
143 (cp)[2] = (unsigned char)((value) >> 8); \
144 (cp)[3] = (unsigned char)(value); }
146 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
148 /* Coroutine mechanics for the sillier bits of the code */
149 #define crBegin1 static int crLine = 0;
150 #define crBegin2 switch(crLine) { case 0:;
151 #define crBegin crBegin1; crBegin2;
152 #define crFinish(z) } crLine = 0; return (z)
153 #define crFinishV } crLine = 0; return
154 #define crReturn(z) \
156 crLine=__LINE__; return (z); case __LINE__:;\
160 crLine=__LINE__; return; case __LINE__:;\
162 #define crStop(z) do{ crLine = 0; return (z); }while(0)
163 #define crStopV do{ crLine = 0; return; }while(0)
164 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
165 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
167 extern const struct ssh_cipher ssh_3des;
168 extern const struct ssh_cipher ssh_3des_ssh2;
169 extern const struct ssh_cipher ssh_des;
170 extern const struct ssh_cipher ssh_blowfish_ssh1;
171 extern const struct ssh_cipher ssh_blowfish_ssh2;
173 extern char *x11_init (Socket *, char *, void *);
174 extern void x11_close (Socket);
175 extern void x11_send (Socket , char *, int);
176 extern void x11_invent_auth(char *, int, char *, int);
179 * Ciphers for SSH2. We miss out single-DES because it isn't
180 * supported; also 3DES and Blowfish are both done differently from
181 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
182 * endianness and different-sized keys.)
184 const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
186 extern const struct ssh_kex ssh_diffiehellman;
187 extern const struct ssh_kex ssh_diffiehellman_gex;
188 const static struct ssh_kex *kex_algs[] = {
189 #ifdef DO_DIFFIE_HELLMAN_GEX
190 &ssh_diffiehellman_gex,
192 &ssh_diffiehellman };
194 extern const struct ssh_signkey ssh_dss;
195 const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss };
197 extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
199 static void nullmac_key(unsigned char *key) { }
200 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
201 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
202 const static struct ssh_mac ssh_mac_none = {
203 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
205 const static struct ssh_mac *macs[] = {
206 &ssh_sha1, &ssh_md5, &ssh_mac_none };
207 const static struct ssh_mac *buggymacs[] = {
208 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
210 static void ssh_comp_none_init(void) { }
211 static int ssh_comp_none_block(unsigned char *block, int len,
212 unsigned char **outblock, int *outlen) {
215 const static struct ssh_compress ssh_comp_none = {
217 ssh_comp_none_init, ssh_comp_none_block,
218 ssh_comp_none_init, ssh_comp_none_block
220 extern const struct ssh_compress ssh_zlib;
221 const static struct ssh_compress *compressions[] = {
222 &ssh_zlib, &ssh_comp_none };
224 enum { /* channel types */
231 * 2-3-4 tree storing channels.
234 unsigned remoteid, localid;
237 struct ssh2_data_channel {
238 unsigned char *outbuffer;
239 unsigned outbuflen, outbufsize;
240 unsigned remwindow, remmaxpkt;
243 struct ssh_agent_channel {
244 unsigned char *message;
245 unsigned char msglen[4];
246 int lensofar, totallen;
248 struct ssh_x11_channel {
263 static SHA_State exhash, exhashbase;
265 static Socket s = NULL;
267 static unsigned char session_key[32];
268 static int ssh1_compressing;
269 static int ssh_agentfwd_enabled;
270 static int ssh_X11_fwd_enabled;
271 static const struct ssh_cipher *cipher = NULL;
272 static const struct ssh_cipher *cscipher = NULL;
273 static const struct ssh_cipher *sccipher = NULL;
274 static const struct ssh_mac *csmac = NULL;
275 static const struct ssh_mac *scmac = NULL;
276 static const struct ssh_compress *cscomp = NULL;
277 static const struct ssh_compress *sccomp = NULL;
278 static const struct ssh_kex *kex = NULL;
279 static const struct ssh_signkey *hostkey = NULL;
280 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
282 static char *savedhost;
283 static int savedport;
284 static int ssh_send_ok;
285 static int ssh_echoing, ssh_editing;
287 static tree234 *ssh_channels; /* indexed by local id */
288 static struct ssh_channel *mainchan; /* primary session channel */
292 SSH_STATE_BEFORE_SIZE,
296 } ssh_state = SSH_STATE_PREPACKET;
298 static int size_needed = FALSE, eof_needed = FALSE;
300 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
301 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
302 static unsigned char *deferred_send_data = NULL;
303 static int deferred_len = 0, deferred_size = 0;
305 static int ssh_version;
306 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
307 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
308 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
309 static void ssh_size(void);
310 static void ssh_special (Telnet_Special);
311 static void ssh2_try_send(struct ssh_channel *c);
312 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
314 static int (*s_rdpkt)(unsigned char **data, int *datalen);
316 static struct rdpkt1_state_tag {
317 long len, pad, biglen, to_read;
318 unsigned long realcrc, gotcrc;
324 static struct rdpkt2_state_tag {
325 long len, pad, payload, packetlen, maclen;
328 unsigned long incoming_sequence;
331 static int ssh_channelcmp(void *av, void *bv) {
332 struct ssh_channel *a = (struct ssh_channel *)av;
333 struct ssh_channel *b = (struct ssh_channel *)bv;
334 if (a->localid < b->localid) return -1;
335 if (a->localid > b->localid) return +1;
338 static int ssh_channelfind(void *av, void *bv) {
339 unsigned *a = (unsigned *)av;
340 struct ssh_channel *b = (struct ssh_channel *)bv;
341 if (*a < b->localid) return -1;
342 if (*a > b->localid) return +1;
346 static void c_write (char *buf, int len) {
347 if ((flags & FLAG_STDERR)) {
349 for (i = 0; i < len; i++)
351 fputc(buf[i], stderr);
354 from_backend(1, buf, len);
358 * Collect incoming data in the incoming packet buffer.
359 * Decipher and verify the packet when it is completely read.
360 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
361 * Update the *data and *datalen variables.
362 * Return the additional nr of bytes needed, or 0 when
363 * a complete packet is available.
365 static int ssh1_rdpkt(unsigned char **data, int *datalen)
367 struct rdpkt1_state_tag *st = &rdpkt1_state;
376 for (st->i = st->len = 0; st->i < 4; st->i++) {
377 while ((*datalen) == 0)
379 st->len = (st->len << 8) + **data;
380 (*data)++, (*datalen)--;
384 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
385 st->len = 0x300; /* big enough to carry to end */
389 st->pad = 8 - (st->len % 8);
390 st->biglen = st->len + st->pad;
391 pktin.length = st->len - 5;
393 if (pktin.maxlen < st->biglen) {
394 pktin.maxlen = st->biglen;
395 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
396 srealloc(pktin.data, st->biglen+APIEXTRA));
398 fatalbox("Out of memory");
401 st->to_read = st->biglen;
403 while (st->to_read > 0) {
404 st->chunk = st->to_read;
405 while ((*datalen) == 0)
406 crReturn(st->to_read);
407 if (st->chunk > (*datalen))
408 st->chunk = (*datalen);
409 memcpy(st->p, *data, st->chunk);
411 *datalen -= st->chunk;
413 st->to_read -= st->chunk;
417 cipher->decrypt(pktin.data, st->biglen);
419 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
420 for (st->i = 0; st->i < st->biglen; st->i++)
421 debug((" %02x", (unsigned char)pktin.data[st->i]));
425 st->realcrc = crc32(pktin.data, st->biglen-4);
426 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
427 if (st->gotcrc != st->realcrc) {
428 bombout(("Incorrect CRC received on packet"));
432 pktin.body = pktin.data + st->pad + 1;
434 if (ssh1_compressing) {
435 unsigned char *decompblk;
439 debug(("Packet payload pre-decompression:\n"));
440 for (i = -1; i < pktin.length; i++)
441 debug((" %02x", (unsigned char)pktin.body[i]));
444 zlib_decompress_block(pktin.body-1, pktin.length+1,
445 &decompblk, &decomplen);
447 if (pktin.maxlen < st->pad + decomplen) {
448 pktin.maxlen = st->pad + decomplen;
449 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
450 pktin.body = pktin.data + st->pad + 1;
452 fatalbox("Out of memory");
455 memcpy(pktin.body-1, decompblk, decomplen);
457 pktin.length = decomplen-1;
459 debug(("Packet payload post-decompression:\n"));
460 for (i = -1; i < pktin.length; i++)
461 debug((" %02x", (unsigned char)pktin.body[i]));
466 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
467 pktin.type == SSH1_SMSG_STDERR_DATA ||
468 pktin.type == SSH1_MSG_DEBUG ||
469 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
470 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
471 long strlen = GET_32BIT(pktin.body);
472 if (strlen + 4 != pktin.length) {
473 bombout(("Received data packet with bogus string length"));
478 pktin.type = pktin.body[-1];
480 if (pktin.type == SSH1_MSG_DEBUG) {
481 /* log debug message */
483 int strlen = GET_32BIT(pktin.body);
484 strcpy(buf, "Remote: ");
485 if (strlen > 70) strlen = 70;
486 memcpy(buf+8, pktin.body+4, strlen);
487 buf[8+strlen] = '\0';
490 } else if (pktin.type == SSH1_MSG_IGNORE) {
498 static int ssh2_rdpkt(unsigned char **data, int *datalen)
500 struct rdpkt2_state_tag *st = &rdpkt2_state;
508 st->cipherblk = sccipher->blksize;
511 if (st->cipherblk < 8)
514 if (pktin.maxlen < st->cipherblk) {
515 pktin.maxlen = st->cipherblk;
516 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
517 srealloc(pktin.data, st->cipherblk+APIEXTRA));
519 fatalbox("Out of memory");
523 * Acquire and decrypt the first block of the packet. This will
524 * contain the length and padding details.
526 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
527 while ((*datalen) == 0)
528 crReturn(st->cipherblk-st->i);
529 pktin.data[st->i] = *(*data)++;
533 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
538 sccipher->decrypt(pktin.data, st->cipherblk);
541 * Now get the length and padding figures.
543 st->len = GET_32BIT(pktin.data);
544 st->pad = pktin.data[4];
547 * This enables us to deduce the payload length.
549 st->payload = st->len - st->pad - 1;
551 pktin.length = st->payload + 5;
554 * So now we can work out the total packet length.
556 st->packetlen = st->len + 4;
557 st->maclen = scmac ? scmac->len : 0;
560 * Adjust memory allocation if packet is too big.
562 if (pktin.maxlen < st->packetlen+st->maclen) {
563 pktin.maxlen = st->packetlen+st->maclen;
564 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
565 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
567 fatalbox("Out of memory");
571 * Read and decrypt the remainder of the packet.
573 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
574 while ((*datalen) == 0)
575 crReturn(st->packetlen + st->maclen - st->i);
576 pktin.data[st->i] = *(*data)++;
579 /* Decrypt everything _except_ the MAC. */
581 sccipher->decrypt(pktin.data + st->cipherblk,
582 st->packetlen - st->cipherblk);
585 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
586 for (st->i = 0; st->i < st->packetlen; st->i++)
587 debug((" %02x", (unsigned char)pktin.data[st->i]));
594 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
595 bombout(("Incorrect MAC received on packet"));
598 st->incoming_sequence++; /* whether or not we MACed */
601 * Decompress packet payload.
604 unsigned char *newpayload;
606 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
607 &newpayload, &newlen)) {
608 if (pktin.maxlen < newlen+5) {
609 pktin.maxlen = newlen+5;
610 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
611 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
613 fatalbox("Out of memory");
615 pktin.length = 5 + newlen;
616 memcpy(pktin.data+5, newpayload, newlen);
618 debug(("Post-decompression payload:\r\n"));
619 for (st->i = 0; st->i < newlen; st->i++)
620 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
629 pktin.type = pktin.data[5];
631 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
632 goto next_packet; /* FIXME: print DEBUG message */
637 static void ssh1_pktout_size(int len) {
640 len += 5; /* type and CRC */
644 pktout.length = len-5;
645 if (pktout.maxlen < biglen) {
646 pktout.maxlen = biglen;
648 /* Allocate enough buffer space for extra block
649 * for MS CryptEncrypt() */
650 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
651 srealloc(pktout.data, biglen+12));
653 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
654 srealloc(pktout.data, biglen+4));
657 fatalbox("Out of memory");
659 pktout.body = pktout.data+4+pad+1;
662 static void s_wrpkt_start(int type, int len) {
663 ssh1_pktout_size(len);
667 static void s_wrpkt(void) {
668 int pad, len, biglen, i;
671 pktout.body[-1] = pktout.type;
673 if (ssh1_compressing) {
674 unsigned char *compblk;
677 debug(("Packet payload pre-compression:\n"));
678 for (i = -1; i < pktout.length; i++)
679 debug((" %02x", (unsigned char)pktout.body[i]));
682 zlib_compress_block(pktout.body-1, pktout.length+1,
684 ssh1_pktout_size(complen-1);
685 memcpy(pktout.body-1, compblk, complen);
688 debug(("Packet payload post-compression:\n"));
689 for (i = -1; i < pktout.length; i++)
690 debug((" %02x", (unsigned char)pktout.body[i]));
695 len = pktout.length + 5; /* type and CRC */
699 for (i=0; i<pad; i++)
700 pktout.data[i+4] = random_byte();
701 crc = crc32(pktout.data+4, biglen-4);
702 PUT_32BIT(pktout.data+biglen, crc);
703 PUT_32BIT(pktout.data, len);
706 debug(("Sending packet len=%d\r\n", biglen+4));
707 for (i = 0; i < biglen+4; i++)
708 debug((" %02x", (unsigned char)pktout.data[i]));
712 cipher->encrypt(pktout.data+4, biglen);
714 sk_write(s, pktout.data, biglen+4);
718 * Construct a packet with the specified contents and
719 * send it to the server.
721 static void send_packet(int pkttype, ...)
724 unsigned char *p, *argp, argchar;
725 unsigned long argint;
726 int pktlen, argtype, arglen;
730 va_start(args, pkttype);
731 while ((argtype = va_arg(args, int)) != PKT_END) {
734 (void) va_arg(args, int);
738 (void) va_arg(args, char);
742 (void) va_arg(args, unsigned char *);
743 arglen = va_arg(args, int);
747 argp = va_arg(args, unsigned char *);
748 arglen = strlen(argp);
749 pktlen += 4 + arglen;
752 bn = va_arg(args, Bignum);
753 pktlen += ssh1_bignum_length(bn);
761 s_wrpkt_start(pkttype, pktlen);
764 va_start(args, pkttype);
765 while ((argtype = va_arg(args, int)) != PKT_END) {
768 argint = va_arg(args, int);
769 PUT_32BIT(p, argint);
773 argchar = va_arg(args, unsigned char);
778 argp = va_arg(args, unsigned char *);
779 arglen = va_arg(args, int);
780 memcpy(p, argp, arglen);
784 argp = va_arg(args, unsigned char *);
785 arglen = strlen(argp);
786 PUT_32BIT(p, arglen);
787 memcpy(p + 4, argp, arglen);
791 bn = va_arg(args, Bignum);
792 p += ssh1_write_bignum(p, bn);
801 static int ssh_versioncmp(char *a, char *b) {
803 unsigned long av, bv;
805 av = strtoul(a, &ae, 10);
806 bv = strtoul(b, &be, 10);
807 if (av != bv) return (av < bv ? -1 : +1);
808 if (*ae == '.') ae++;
809 if (*be == '.') be++;
810 av = strtoul(ae, &ae, 10);
811 bv = strtoul(be, &be, 10);
812 if (av != bv) return (av < bv ? -1 : +1);
818 * Utility routines for putting an SSH-protocol `string' and
819 * `uint32' into a SHA state.
822 static void sha_string(SHA_State *s, void *str, int len) {
823 unsigned char lenblk[4];
824 PUT_32BIT(lenblk, len);
825 SHA_Bytes(s, lenblk, 4);
826 SHA_Bytes(s, str, len);
829 static void sha_uint32(SHA_State *s, unsigned i) {
830 unsigned char intblk[4];
831 PUT_32BIT(intblk, i);
832 SHA_Bytes(s, intblk, 4);
836 * SSH2 packet construction functions.
838 static void ssh2_pkt_ensure(int length) {
839 if (pktout.maxlen < length) {
840 pktout.maxlen = length + 256;
841 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
842 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
844 fatalbox("Out of memory");
847 static void ssh2_pkt_adddata(void *data, int len) {
848 pktout.length += len;
849 ssh2_pkt_ensure(pktout.length);
850 memcpy(pktout.data+pktout.length-len, data, len);
852 static void ssh2_pkt_addbyte(unsigned char byte) {
853 ssh2_pkt_adddata(&byte, 1);
855 static void ssh2_pkt_init(int pkt_type) {
857 ssh2_pkt_addbyte((unsigned char)pkt_type);
859 static void ssh2_pkt_addbool(unsigned char value) {
860 ssh2_pkt_adddata(&value, 1);
862 static void ssh2_pkt_adduint32(unsigned long value) {
865 ssh2_pkt_adddata(x, 4);
867 static void ssh2_pkt_addstring_start(void) {
868 ssh2_pkt_adduint32(0);
869 pktout.savedpos = pktout.length;
871 static void ssh2_pkt_addstring_str(char *data) {
872 ssh2_pkt_adddata(data, strlen(data));
873 PUT_32BIT(pktout.data + pktout.savedpos - 4,
874 pktout.length - pktout.savedpos);
876 static void ssh2_pkt_addstring_data(char *data, int len) {
877 ssh2_pkt_adddata(data, len);
878 PUT_32BIT(pktout.data + pktout.savedpos - 4,
879 pktout.length - pktout.savedpos);
881 static void ssh2_pkt_addstring(char *data) {
882 ssh2_pkt_addstring_start();
883 ssh2_pkt_addstring_str(data);
885 static char *ssh2_mpint_fmt(Bignum b, int *len) {
887 int i, n = (ssh1_bignum_bitcount(b)+7)/8;
890 fatalbox("out of memory");
892 for (i = 1; i <= n; i++)
893 p[i] = bignum_byte(b, n-i);
895 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
897 memmove(p, p+i, n+1-i);
901 static void ssh2_pkt_addmp(Bignum b) {
904 p = ssh2_mpint_fmt(b, &len);
905 ssh2_pkt_addstring_start();
906 ssh2_pkt_addstring_data(p, len);
911 * Construct an SSH2 final-form packet: compress it, encrypt it,
912 * put the MAC on it. Final packet, ready to be sent, is stored in
913 * pktout.data. Total length is returned.
915 static int ssh2_pkt_construct(void) {
916 int cipherblk, maclen, padding, i;
917 static unsigned long outgoing_sequence = 0;
920 * Compress packet payload.
923 debug(("Pre-compression payload:\r\n"));
924 for (i = 5; i < pktout.length; i++)
925 debug((" %02x", (unsigned char)pktout.data[i]));
929 unsigned char *newpayload;
931 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
932 &newpayload, &newlen)) {
934 ssh2_pkt_adddata(newpayload, newlen);
940 * Add padding. At least four bytes, and must also bring total
941 * length (minus MAC) up to a multiple of the block size.
943 cipherblk = cipher ? cipher->blksize : 8; /* block size */
944 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
946 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
947 maclen = csmac ? csmac->len : 0;
948 ssh2_pkt_ensure(pktout.length + padding + maclen);
949 pktout.data[4] = padding;
950 for (i = 0; i < padding; i++)
951 pktout.data[pktout.length + i] = random_byte();
952 PUT_32BIT(pktout.data, pktout.length + padding - 4);
954 csmac->generate(pktout.data, pktout.length + padding,
956 outgoing_sequence++; /* whether or not we MACed */
959 debug(("Sending packet len=%d\r\n", pktout.length+padding));
960 for (i = 0; i < pktout.length+padding; i++)
961 debug((" %02x", (unsigned char)pktout.data[i]));
966 cscipher->encrypt(pktout.data, pktout.length + padding);
968 /* Ready-to-send packet starts at pktout.data. We return length. */
969 return pktout.length + padding + maclen;
973 * Construct and send an SSH2 packet immediately.
975 static void ssh2_pkt_send(void) {
976 int len = ssh2_pkt_construct();
977 sk_write(s, pktout.data, len);
981 * Construct an SSH2 packet and add it to a deferred data block.
982 * Useful for sending multiple packets in a single sk_write() call,
983 * to prevent a traffic-analysing listener from being able to work
984 * out the length of any particular packet (such as the password
987 * Note that because SSH2 sequence-numbers its packets, this can
988 * NOT be used as an m4-style `defer' allowing packets to be
989 * constructed in one order and sent in another.
991 static void ssh2_pkt_defer(void) {
992 int len = ssh2_pkt_construct();
993 if (deferred_len + len > deferred_size) {
994 deferred_size = deferred_len + len + 128;
995 deferred_send_data = srealloc(deferred_send_data, deferred_size);
997 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1002 * Send the whole deferred data block constructed by
1005 static void ssh2_pkt_defersend(void) {
1006 sk_write(s, deferred_send_data, deferred_len);
1007 deferred_len = deferred_size = 0;
1008 sfree(deferred_send_data);
1009 deferred_send_data = NULL;
1013 void bndebug(char *string, Bignum b) {
1016 p = ssh2_mpint_fmt(b, &len);
1017 debug(("%s", string));
1018 for (i = 0; i < len; i++)
1019 debug((" %02x", p[i]));
1025 static void sha_mpint(SHA_State *s, Bignum b) {
1028 p = ssh2_mpint_fmt(b, &len);
1029 sha_string(s, p, len);
1034 * SSH2 packet decode functions.
1036 static unsigned long ssh2_pkt_getuint32(void) {
1037 unsigned long value;
1038 if (pktin.length - pktin.savedpos < 4)
1039 return 0; /* arrgh, no way to decline (FIXME?) */
1040 value = GET_32BIT(pktin.data+pktin.savedpos);
1041 pktin.savedpos += 4;
1044 static void ssh2_pkt_getstring(char **p, int *length) {
1046 if (pktin.length - pktin.savedpos < 4)
1048 *length = GET_32BIT(pktin.data+pktin.savedpos);
1049 pktin.savedpos += 4;
1050 if (pktin.length - pktin.savedpos < *length)
1052 *p = pktin.data+pktin.savedpos;
1053 pktin.savedpos += *length;
1055 static Bignum ssh2_pkt_getmp(void) {
1060 ssh2_pkt_getstring(&p, &length);
1064 bombout(("internal error: Can't handle negative mpints"));
1067 b = bignum_from_bytes(p, length);
1071 static int do_ssh_init(unsigned char c) {
1073 static char version[10];
1074 static char vstring[80];
1075 static char vlog[sizeof(vstring)+20];
1080 /* Search for the string "SSH-" in the input. */
1083 static const int transS[] = { 1, 2, 2, 1 };
1084 static const int transH[] = { 0, 0, 3, 0 };
1085 static const int transminus[] = { 0, 0, 0, -1 };
1086 if (c == 'S') i = transS[i];
1087 else if (c == 'H') i = transH[i];
1088 else if (c == '-') i = transminus[i];
1092 crReturn(1); /* get another character */
1095 strcpy(vstring, "SSH-");
1099 crReturn(1); /* get another char */
1100 if (vsp < vstring+sizeof(vstring)-1)
1106 } else if (i < sizeof(version)-1)
1113 ssh_agentfwd_enabled = FALSE;
1114 rdpkt2_state.incoming_sequence = 0;
1117 sprintf(vlog, "Server version: %s", vstring);
1118 vlog[strcspn(vlog, "\r\n")] = '\0';
1122 * Server version "1.99" means we can choose whether we use v1
1123 * or v2 protocol. Choice is based on cfg.sshprot.
1125 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1127 * This is a v2 server. Begin v2 protocol.
1129 char *verstring = "SSH-2.0-PuTTY";
1130 SHA_Init(&exhashbase);
1132 * Hash our version string and their version string.
1134 sha_string(&exhashbase, verstring, strlen(verstring));
1135 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1136 sprintf(vstring, "%s\n", verstring);
1137 sprintf(vlog, "We claim version: %s", verstring);
1139 logevent("Using SSH protocol version 2");
1140 sk_write(s, vstring, strlen(vstring));
1141 ssh_protocol = ssh2_protocol;
1143 s_rdpkt = ssh2_rdpkt;
1146 * This is a v1 server. Begin v1 protocol.
1148 sprintf(vstring, "SSH-%s-PuTTY\n",
1149 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1150 sprintf(vlog, "We claim version: %s", vstring);
1151 vlog[strcspn(vlog, "\r\n")] = '\0';
1153 logevent("Using SSH protocol version 1");
1154 sk_write(s, vstring, strlen(vstring));
1155 ssh_protocol = ssh1_protocol;
1157 s_rdpkt = ssh1_rdpkt;
1159 ssh_state = SSH_STATE_BEFORE_SIZE;
1164 static void ssh_gotdata(unsigned char *data, int datalen)
1169 * To begin with, feed the characters one by one to the
1170 * protocol initialisation / selection function do_ssh_init().
1171 * When that returns 0, we're done with the initial greeting
1172 * exchange and can move on to packet discipline.
1177 crReturnV; /* more data please */
1178 ret = do_ssh_init(*data);
1185 * We emerge from that loop when the initial negotiation is
1186 * over and we have selected an s_rdpkt function. Now pass
1187 * everything to s_rdpkt, and then pass the resulting packets
1188 * to the proper protocol handler.
1193 while (datalen > 0) {
1194 if ( s_rdpkt(&data, &datalen) == 0 ) {
1195 ssh_protocol(NULL, 0, 1);
1196 if (ssh_state == SSH_STATE_CLOSED) {
1206 static int ssh_receive(Socket skt, int urgent, char *data, int len) {
1208 /* A socket error has occurred. */
1209 ssh_state = SSH_STATE_CLOSED;
1212 connection_fatal(data);
1215 /* Connection has closed. */
1216 ssh_state = SSH_STATE_CLOSED;
1221 ssh_gotdata (data, len);
1222 if (ssh_state == SSH_STATE_CLOSED) {
1233 * Connect to specified host and port.
1234 * Returns an error message, or NULL on success.
1235 * Also places the canonical host name into `realhost'.
1237 static char *connect_to_host(char *host, int port, char **realhost)
1246 savedhost = smalloc(1+strlen(host));
1248 fatalbox("Out of memory");
1249 strcpy(savedhost, host);
1252 port = 22; /* default ssh port */
1265 addr = sk_namelookup(host, realhost);
1266 if ( (err = sk_addr_error(addr)) )
1276 s = sk_new(addr, port, 0, 1, ssh_receive);
1277 if ( (err = sk_socket_error(s)) )
1281 sk_write(s, "connect ", 8);
1282 sk_write(s, FWhost, strlen(FWhost));
1285 sprintf(buf, " %d\n", FWport);
1286 sk_write(s, buf, strlen(buf));
1294 * Handle the key exchange and user authentication phases.
1296 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1299 unsigned char *rsabuf, *keystr1, *keystr2;
1300 unsigned char cookie[8];
1301 struct RSAKey servkey, hostkey;
1302 struct MD5Context md5c;
1303 static unsigned long supported_ciphers_mask, supported_auths_mask;
1304 static int tried_publickey;
1305 static unsigned char session_id[16];
1307 static char username[100];
1311 if (!ispkt) crWaitUntil(ispkt);
1313 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1314 bombout(("Public key packet not received"));
1318 logevent("Received public keys");
1320 memcpy(cookie, pktin.body, 8);
1322 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1323 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1326 * Log the host key fingerprint.
1330 logevent("Host key fingerprint is:");
1331 strcpy(logmsg, " ");
1332 hostkey.comment = NULL;
1333 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1338 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1339 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1342 MD5Update(&md5c, keystr2, hostkey.bytes);
1343 MD5Update(&md5c, keystr1, servkey.bytes);
1344 MD5Update(&md5c, pktin.body, 8);
1345 MD5Final(session_id, &md5c);
1347 for (i=0; i<32; i++)
1348 session_key[i] = random_byte();
1350 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1352 rsabuf = smalloc(len);
1354 fatalbox("Out of memory");
1357 * Verify the host key.
1361 * First format the key into a string.
1363 int len = rsastr_len(&hostkey);
1364 char fingerprint[100];
1365 char *keystr = smalloc(len);
1367 fatalbox("Out of memory");
1368 rsastr_fmt(keystr, &hostkey);
1369 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1370 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1374 for (i=0; i<32; i++) {
1375 rsabuf[i] = session_key[i];
1377 rsabuf[i] ^= session_id[i];
1380 if (hostkey.bytes > servkey.bytes) {
1381 rsaencrypt(rsabuf, 32, &servkey);
1382 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1384 rsaencrypt(rsabuf, 32, &hostkey);
1385 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1388 logevent("Encrypted session key");
1390 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
1391 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
1393 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1394 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1395 cipher_type = SSH_CIPHER_3DES;
1397 switch (cipher_type) {
1398 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1399 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1400 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1403 send_packet(SSH1_CMSG_SESSION_KEY,
1404 PKT_CHAR, cipher_type,
1405 PKT_DATA, cookie, 8,
1406 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1407 PKT_DATA, rsabuf, len,
1411 logevent("Trying to enable encryption...");
1415 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1416 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1418 cipher->sesskey(session_key);
1422 if (pktin.type != SSH1_SMSG_SUCCESS) {
1423 bombout(("Encryption not successfully enabled"));
1427 logevent("Successfully started encryption");
1433 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1434 c_write("login as: ", 10);
1437 crWaitUntil(!ispkt);
1438 while (inlen--) switch (c = *in++) {
1445 c_write("\b \b", 3);
1451 c_write("\b \b", 3);
1460 if (((c >= ' ' && c <= '~') ||
1461 ((unsigned char)c >= 160)) && pos < 40) {
1462 username[pos++] = c;
1469 username[strcspn(username, "\n\r")] = '\0';
1471 strncpy(username, cfg.username, 99);
1472 username[99] = '\0';
1475 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1477 char userlog[22+sizeof(username)];
1478 sprintf(userlog, "Sent username \"%s\"", username);
1480 if (flags & FLAG_INTERACTIVE &&
1481 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1482 strcat(userlog, "\r\n");
1483 c_write(userlog, strlen(userlog));
1490 tried_publickey = 0;
1492 while (pktin.type == SSH1_SMSG_FAILURE) {
1493 static char password[100];
1494 static char prompt[200];
1497 static int pwpkt_type;
1499 * Show password prompt, having first obtained it via a TIS
1500 * or CryptoCard exchange if we're doing TIS or CryptoCard
1503 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1504 if (agent_exists()) {
1506 * Attempt RSA authentication using Pageant.
1508 static unsigned char request[5], *response, *p;
1509 static int responselen;
1510 static int i, nkeys;
1511 static int authed = FALSE;
1514 logevent("Pageant is running. Requesting keys.");
1516 /* Request the keys held by the agent. */
1517 PUT_32BIT(request, 1);
1518 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1519 agent_query(request, 5, &r, &responselen);
1520 response = (unsigned char *)r;
1523 nkeys = GET_32BIT(p); p += 4;
1524 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1526 for (i = 0; i < nkeys; i++) {
1527 static struct RSAKey key;
1528 static Bignum challenge;
1529 static char *commentp;
1530 static int commentlen;
1532 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1535 p += ssh1_read_bignum(p, &key.exponent);
1536 p += ssh1_read_bignum(p, &key.modulus);
1537 commentlen = GET_32BIT(p); p += 4;
1538 commentp = p; p += commentlen;
1539 send_packet(SSH1_CMSG_AUTH_RSA,
1540 PKT_BIGNUM, key.modulus, PKT_END);
1542 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1543 logevent("Key refused");
1546 logevent("Received RSA challenge");
1547 ssh1_read_bignum(pktin.body, &challenge);
1549 char *agentreq, *q, *ret;
1551 len = 1 + 4; /* message type, bit count */
1552 len += ssh1_bignum_length(key.exponent);
1553 len += ssh1_bignum_length(key.modulus);
1554 len += ssh1_bignum_length(challenge);
1555 len += 16; /* session id */
1556 len += 4; /* response format */
1557 agentreq = smalloc(4 + len);
1558 PUT_32BIT(agentreq, len);
1560 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1561 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1563 q += ssh1_write_bignum(q, key.exponent);
1564 q += ssh1_write_bignum(q, key.modulus);
1565 q += ssh1_write_bignum(q, challenge);
1566 memcpy(q, session_id, 16); q += 16;
1567 PUT_32BIT(q, 1); /* response format */
1568 agent_query(agentreq, len+4, &ret, &retlen);
1571 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1572 logevent("Sending Pageant's response");
1573 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1574 PKT_DATA, ret+5, 16, PKT_END);
1577 if (pktin.type == SSH1_SMSG_SUCCESS) {
1578 logevent("Pageant's response accepted");
1579 if (flags & FLAG_VERBOSE) {
1580 c_write("Authenticated using RSA key \"",
1582 c_write(commentp, commentlen);
1583 c_write("\" from agent\r\n", 14);
1587 logevent("Pageant's response not accepted");
1589 logevent("Pageant failed to answer challenge");
1593 logevent("No reply received from Pageant");
1596 freebn(key.exponent);
1597 freebn(key.modulus);
1606 if (*cfg.keyfile && !tried_publickey)
1607 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1609 if (pktin.type == SSH1_SMSG_FAILURE &&
1611 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1612 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1613 logevent("Requested TIS authentication");
1614 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1616 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1617 logevent("TIS authentication declined");
1618 if (flags & FLAG_INTERACTIVE)
1619 c_write("TIS authentication refused.\r\n", 29);
1621 int challengelen = ((pktin.body[0] << 24) |
1622 (pktin.body[1] << 16) |
1623 (pktin.body[2] << 8) |
1625 logevent("Received TIS challenge");
1626 if (challengelen > sizeof(prompt)-1)
1627 challengelen = sizeof(prompt)-1; /* prevent overrun */
1628 memcpy(prompt, pktin.body+4, challengelen);
1629 prompt[challengelen] = '\0';
1632 if (pktin.type == SSH1_SMSG_FAILURE &&
1634 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1635 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1636 logevent("Requested CryptoCard authentication");
1637 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1639 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1640 logevent("CryptoCard authentication declined");
1641 c_write("CryptoCard authentication refused.\r\n", 29);
1643 int challengelen = ((pktin.body[0] << 24) |
1644 (pktin.body[1] << 16) |
1645 (pktin.body[2] << 8) |
1647 logevent("Received CryptoCard challenge");
1648 if (challengelen > sizeof(prompt)-1)
1649 challengelen = sizeof(prompt)-1; /* prevent overrun */
1650 memcpy(prompt, pktin.body+4, challengelen);
1651 strncpy(prompt + challengelen, "\r\nResponse : ",
1652 sizeof(prompt)-challengelen);
1653 prompt[sizeof(prompt)-1] = '\0';
1656 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1657 sprintf(prompt, "%.90s@%.90s's password: ",
1658 username, savedhost);
1660 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1661 char *comment = NULL;
1662 if (flags & FLAG_VERBOSE)
1663 c_write("Trying public key authentication.\r\n", 35);
1664 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1665 if (flags & FLAG_VERBOSE)
1666 c_write("No passphrase required.\r\n", 25);
1669 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1673 if (ssh_get_password) {
1674 if (!ssh_get_password(prompt, password, sizeof(password))) {
1676 * get_password failed to get a password (for
1677 * example because one was supplied on the command
1678 * line which has already failed to work).
1681 logevent("No more passwords to try");
1682 ssh_state = SSH_STATE_CLOSED;
1686 c_write(prompt, strlen(prompt));
1690 crWaitUntil(!ispkt);
1691 while (inlen--) switch (c = *in++) {
1708 if (((c >= ' ' && c <= '~') ||
1709 ((unsigned char)c >= 160)) && pos < sizeof(password))
1710 password[pos++] = c;
1718 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1720 * Try public key authentication with the specified
1723 static struct RSAKey pubkey;
1724 static Bignum challenge, response;
1726 static unsigned char buffer[32];
1728 tried_publickey = 1;
1729 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
1731 c_write("Couldn't load public key from ", 30);
1732 c_write(cfg.keyfile, strlen(cfg.keyfile));
1733 c_write(".\r\n", 3);
1734 continue; /* go and try password */
1737 c_write("Wrong passphrase.\r\n", 19);
1738 tried_publickey = 0;
1739 continue; /* try again */
1743 * Send a public key attempt.
1745 send_packet(SSH1_CMSG_AUTH_RSA,
1746 PKT_BIGNUM, pubkey.modulus, PKT_END);
1749 if (pktin.type == SSH1_SMSG_FAILURE) {
1750 c_write("Server refused our public key.\r\n", 32);
1751 continue; /* go and try password */
1753 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1754 bombout(("Bizarre response to offer of public key"));
1757 ssh1_read_bignum(pktin.body, &challenge);
1758 response = rsadecrypt(challenge, &pubkey);
1759 freebn(pubkey.private_exponent); /* burn the evidence */
1761 for (i = 0; i < 32; i++) {
1762 buffer[i] = bignum_byte(response, 31-i);
1766 MD5Update(&md5c, buffer, 32);
1767 MD5Update(&md5c, session_id, 16);
1768 MD5Final(buffer, &md5c);
1770 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1771 PKT_DATA, buffer, 16, PKT_END);
1774 if (pktin.type == SSH1_SMSG_FAILURE) {
1775 if (flags & FLAG_VERBOSE)
1776 c_write("Failed to authenticate with our public key.\r\n",
1778 continue; /* go and try password */
1779 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1780 bombout(("Bizarre response to RSA authentication response"));
1784 break; /* we're through! */
1786 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1788 logevent("Sent password");
1789 memset(password, 0, strlen(password));
1791 if (pktin.type == SSH1_SMSG_FAILURE) {
1792 if (flags & FLAG_VERBOSE)
1793 c_write("Access denied\r\n", 15);
1794 logevent("Authentication refused");
1795 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1796 logevent("Received disconnect request");
1797 ssh_state = SSH_STATE_CLOSED;
1799 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1800 bombout(("Strange packet received, type %d", pktin.type));
1805 logevent("Authentication successful");
1810 void sshfwd_close(struct ssh_channel *c) {
1812 if (ssh_version == 1) {
1813 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1815 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1816 ssh2_pkt_adduint32(c->remoteid);
1820 if (c->type == CHAN_X11) {
1822 logevent("X11 connection terminated");
1827 void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
1828 if (ssh_version == 1) {
1829 send_packet(SSH1_MSG_CHANNEL_DATA,
1830 PKT_INT, c->remoteid,
1835 ssh2_add_channel_data(c, buf, len);
1840 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1845 while (!do_ssh1_login(in, inlen, ispkt)) {
1848 if (ssh_state == SSH_STATE_CLOSED)
1851 if (cfg.agentfwd && agent_exists()) {
1852 logevent("Requesting agent forwarding");
1853 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1854 do { crReturnV; } while (!ispkt);
1855 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1856 bombout(("Protocol confusion"));
1858 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1859 logevent("Agent forwarding refused");
1861 logevent("Agent forwarding enabled");
1862 ssh_agentfwd_enabled = TRUE;
1866 if (cfg.x11_forward) {
1867 char proto[20], data[64];
1868 logevent("Requesting X11 forwarding");
1869 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
1870 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
1871 PKT_STR, proto, PKT_STR, data,
1874 do { crReturnV; } while (!ispkt);
1875 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1876 bombout(("Protocol confusion"));
1878 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1879 logevent("X11 forwarding refused");
1881 logevent("X11 forwarding enabled");
1882 ssh_X11_fwd_enabled = TRUE;
1887 send_packet(SSH1_CMSG_REQUEST_PTY,
1888 PKT_STR, cfg.termtype,
1889 PKT_INT, rows, PKT_INT, cols,
1890 PKT_INT, 0, PKT_INT, 0,
1893 ssh_state = SSH_STATE_INTERMED;
1894 do { crReturnV; } while (!ispkt);
1895 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1896 bombout(("Protocol confusion"));
1898 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1899 c_write("Server refused to allocate pty\r\n", 32);
1900 ssh_editing = ssh_echoing = 1;
1902 logevent("Allocated pty");
1904 ssh_editing = ssh_echoing = 1;
1907 if (cfg.compression) {
1908 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1909 do { crReturnV; } while (!ispkt);
1910 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1911 bombout(("Protocol confusion"));
1913 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1914 c_write("Server refused to compress\r\n", 32);
1916 logevent("Started compression");
1917 ssh1_compressing = TRUE;
1918 zlib_compress_init();
1919 zlib_decompress_init();
1922 if (*cfg.remote_cmd)
1923 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1925 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1926 logevent("Started session");
1928 ssh_state = SSH_STATE_SESSION;
1932 ssh_special(TS_EOF);
1934 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
1936 ssh_channels = newtree234(ssh_channelcmp);
1940 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1941 pktin.type == SSH1_SMSG_STDERR_DATA) {
1942 long len = GET_32BIT(pktin.body);
1943 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1945 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1946 ssh_state = SSH_STATE_CLOSED;
1947 logevent("Received disconnect request");
1949 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
1950 /* Remote side is trying to open a channel to talk to our
1951 * X-Server. Give them back a local channel number. */
1953 struct ssh_channel *c, *d;
1956 logevent("Received X11 connect request");
1957 /* Refuse if X11 forwarding is disabled. */
1958 if (!ssh_X11_fwd_enabled) {
1959 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1960 PKT_INT, GET_32BIT(pktin.body),
1962 logevent("Rejected X11 connect request");
1964 c = smalloc(sizeof(struct ssh_channel));
1966 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
1967 logevent("opening X11 forward connection failed");
1969 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1970 PKT_INT, GET_32BIT(pktin.body),
1973 logevent("opening X11 forward connection succeeded");
1974 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
1976 break; /* found a free number */
1979 c->remoteid = GET_32BIT(pktin.body);
1982 c->type = CHAN_X11; /* identify channel type */
1983 add234(ssh_channels, c);
1984 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1985 PKT_INT, c->remoteid, PKT_INT, c->localid,
1987 logevent("Opened X11 forward channel");
1990 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1991 /* Remote side is trying to open a channel to talk to our
1992 * agent. Give them back a local channel number. */
1994 struct ssh_channel *c;
1997 /* Refuse if agent forwarding is disabled. */
1998 if (!ssh_agentfwd_enabled) {
1999 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2000 PKT_INT, GET_32BIT(pktin.body),
2004 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
2006 break; /* found a free number */
2009 c = smalloc(sizeof(struct ssh_channel));
2010 c->remoteid = GET_32BIT(pktin.body);
2013 c->type = CHAN_AGENT; /* identify channel type */
2014 c->u.a.lensofar = 0;
2015 add234(ssh_channels, c);
2016 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2017 PKT_INT, c->remoteid, PKT_INT, c->localid,
2020 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2021 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2022 /* Remote side closes a channel. */
2023 unsigned i = GET_32BIT(pktin.body);
2024 struct ssh_channel *c;
2025 c = find234(ssh_channels, &i, ssh_channelfind);
2028 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2029 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
2030 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2031 logevent("X11 connection closed");
2032 assert(c->u.x11.s != NULL);
2033 x11_close(c->u.x11.s);
2036 c->closes |= closetype;
2037 if (c->closes == 3) {
2038 del234(ssh_channels, c);
2042 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2043 /* Data sent down one of our channels. */
2044 int i = GET_32BIT(pktin.body);
2045 int len = GET_32BIT(pktin.body+4);
2046 unsigned char *p = pktin.body+8;
2047 struct ssh_channel *c;
2048 c = find234(ssh_channels, &i, ssh_channelfind);
2052 x11_send(c->u.x11.s, p, len);
2055 /* Data for an agent message. Buffer it. */
2057 if (c->u.a.lensofar < 4) {
2058 int l = min(4 - c->u.a.lensofar, len);
2059 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2060 p += l; len -= l; c->u.a.lensofar += l;
2062 if (c->u.a.lensofar == 4) {
2063 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
2064 c->u.a.message = smalloc(c->u.a.totallen);
2065 memcpy(c->u.a.message, c->u.a.msglen, 4);
2067 if (c->u.a.lensofar >= 4 && len > 0) {
2068 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2069 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2070 p += l; len -= l; c->u.a.lensofar += l;
2072 if (c->u.a.lensofar == c->u.a.totallen) {
2073 void *reply, *sentreply;
2075 agent_query(c->u.a.message, c->u.a.totallen,
2080 /* Fake SSH_AGENT_FAILURE. */
2081 sentreply = "\0\0\0\1\5";
2084 send_packet(SSH1_MSG_CHANNEL_DATA,
2085 PKT_INT, c->remoteid,
2087 PKT_DATA, sentreply, replylen,
2091 sfree(c->u.a.message);
2092 c->u.a.lensofar = 0;
2098 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2099 /* may be from EXEC_SHELL on some servers */
2100 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2101 /* may be from EXEC_SHELL on some servers
2102 * if no pty is available or in other odd cases. Ignore */
2103 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2104 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2106 bombout(("Strange packet received: type %d", pktin.type));
2111 int len = min(inlen, 512);
2112 send_packet(SSH1_CMSG_STDIN_DATA,
2113 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2124 * Utility routine for decoding comma-separated strings in KEXINIT.
2126 static int in_commasep_string(char *needle, char *haystack, int haylen) {
2127 int needlen = strlen(needle);
2130 * Is it at the start of the string?
2132 if (haylen >= needlen && /* haystack is long enough */
2133 !memcmp(needle, haystack, needlen) && /* initial match */
2134 (haylen == needlen || haystack[needlen] == ',')
2135 /* either , or EOS follows */
2139 * If not, search for the next comma and resume after that.
2140 * If no comma found, terminate.
2142 while (haylen > 0 && *haystack != ',')
2143 haylen--, haystack++;
2146 haylen--, haystack++; /* skip over comma itself */
2151 * SSH2 key creation method.
2153 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
2155 /* First 20 bytes. */
2158 SHA_Bytes(&s, H, 20);
2159 SHA_Bytes(&s, &chr, 1);
2160 SHA_Bytes(&s, sessid, 20);
2161 SHA_Final(&s, keyspace);
2162 /* Next 20 bytes. */
2165 SHA_Bytes(&s, H, 20);
2166 SHA_Bytes(&s, keyspace, 20);
2167 SHA_Final(&s, keyspace+20);
2171 * Handle the SSH2 transport layer.
2173 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2175 static int i, len, nbits;
2177 static Bignum p, g, e, f, K;
2178 static int kex_init_value, kex_reply_value;
2179 static const struct ssh_mac **maclist;
2181 static const struct ssh_cipher *cscipher_tobe = NULL;
2182 static const struct ssh_cipher *sccipher_tobe = NULL;
2183 static const struct ssh_mac *csmac_tobe = NULL;
2184 static const struct ssh_mac *scmac_tobe = NULL;
2185 static const struct ssh_compress *cscomp_tobe = NULL;
2186 static const struct ssh_compress *sccomp_tobe = NULL;
2187 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2188 static int hostkeylen, siglen;
2189 static void *hkey; /* actual host key */
2190 static unsigned char exchange_hash[20];
2191 static unsigned char first_exchange_hash[20];
2192 static unsigned char keyspace[40];
2193 static const struct ssh_cipher *preferred_cipher;
2194 static const struct ssh_compress *preferred_comp;
2195 static int first_kex;
2202 * Set up the preferred cipher and compression.
2204 if (cfg.cipher == CIPHER_BLOWFISH) {
2205 preferred_cipher = &ssh_blowfish_ssh2;
2206 } else if (cfg.cipher == CIPHER_DES) {
2207 logevent("Single DES not supported in SSH2; using 3DES");
2208 preferred_cipher = &ssh_3des_ssh2;
2209 } else if (cfg.cipher == CIPHER_3DES) {
2210 preferred_cipher = &ssh_3des_ssh2;
2212 /* Shouldn't happen, but we do want to initialise to _something_. */
2213 preferred_cipher = &ssh_3des_ssh2;
2215 if (cfg.compression)
2216 preferred_comp = &ssh_zlib;
2218 preferred_comp = &ssh_comp_none;
2221 * Be prepared to work around the buggy MAC problem.
2224 maclist = buggymacs, nmacs = lenof(buggymacs);
2226 maclist = macs, nmacs = lenof(macs);
2230 * Construct and send our key exchange packet.
2232 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2233 for (i = 0; i < 16; i++)
2234 ssh2_pkt_addbyte((unsigned char)random_byte());
2235 /* List key exchange algorithms. */
2236 ssh2_pkt_addstring_start();
2237 for (i = 0; i < lenof(kex_algs); i++) {
2238 ssh2_pkt_addstring_str(kex_algs[i]->name);
2239 if (i < lenof(kex_algs)-1)
2240 ssh2_pkt_addstring_str(",");
2242 /* List server host key algorithms. */
2243 ssh2_pkt_addstring_start();
2244 for (i = 0; i < lenof(hostkey_algs); i++) {
2245 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2246 if (i < lenof(hostkey_algs)-1)
2247 ssh2_pkt_addstring_str(",");
2249 /* List client->server encryption algorithms. */
2250 ssh2_pkt_addstring_start();
2251 for (i = 0; i < lenof(ciphers)+1; i++) {
2252 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2253 ssh2_pkt_addstring_str(c->name);
2254 if (i < lenof(ciphers))
2255 ssh2_pkt_addstring_str(",");
2257 /* List server->client encryption algorithms. */
2258 ssh2_pkt_addstring_start();
2259 for (i = 0; i < lenof(ciphers)+1; i++) {
2260 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2261 ssh2_pkt_addstring_str(c->name);
2262 if (i < lenof(ciphers))
2263 ssh2_pkt_addstring_str(",");
2265 /* List client->server MAC algorithms. */
2266 ssh2_pkt_addstring_start();
2267 for (i = 0; i < nmacs; i++) {
2268 ssh2_pkt_addstring_str(maclist[i]->name);
2270 ssh2_pkt_addstring_str(",");
2272 /* List server->client MAC algorithms. */
2273 ssh2_pkt_addstring_start();
2274 for (i = 0; i < nmacs; i++) {
2275 ssh2_pkt_addstring_str(maclist[i]->name);
2277 ssh2_pkt_addstring_str(",");
2279 /* List client->server compression algorithms. */
2280 ssh2_pkt_addstring_start();
2281 for (i = 0; i < lenof(compressions)+1; i++) {
2282 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2283 ssh2_pkt_addstring_str(c->name);
2284 if (i < lenof(compressions))
2285 ssh2_pkt_addstring_str(",");
2287 /* List server->client compression algorithms. */
2288 ssh2_pkt_addstring_start();
2289 for (i = 0; i < lenof(compressions)+1; i++) {
2290 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2291 ssh2_pkt_addstring_str(c->name);
2292 if (i < lenof(compressions))
2293 ssh2_pkt_addstring_str(",");
2295 /* List client->server languages. Empty list. */
2296 ssh2_pkt_addstring_start();
2297 /* List server->client languages. Empty list. */
2298 ssh2_pkt_addstring_start();
2299 /* First KEX packet does _not_ follow, because we're not that brave. */
2300 ssh2_pkt_addbool(FALSE);
2302 ssh2_pkt_adduint32(0);
2304 exhash = exhashbase;
2305 sha_string(&exhash, pktout.data+5, pktout.length-5);
2309 if (!ispkt) crWaitUntil(ispkt);
2310 sha_string(&exhash, pktin.data+5, pktin.length-5);
2313 * Now examine the other side's KEXINIT to see what we're up
2316 if (pktin.type != SSH2_MSG_KEXINIT) {
2317 bombout(("expected key exchange packet from server"));
2320 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2321 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2322 pktin.savedpos += 16; /* skip garbage cookie */
2323 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2324 for (i = 0; i < lenof(kex_algs); i++) {
2325 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2330 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2331 for (i = 0; i < lenof(hostkey_algs); i++) {
2332 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2333 hostkey = hostkey_algs[i];
2337 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2338 for (i = 0; i < lenof(ciphers)+1; i++) {
2339 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2340 if (in_commasep_string(c->name, str, len)) {
2345 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2346 for (i = 0; i < lenof(ciphers)+1; i++) {
2347 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2348 if (in_commasep_string(c->name, str, len)) {
2353 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2354 for (i = 0; i < nmacs; i++) {
2355 if (in_commasep_string(maclist[i]->name, str, len)) {
2356 csmac_tobe = maclist[i];
2360 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2361 for (i = 0; i < nmacs; i++) {
2362 if (in_commasep_string(maclist[i]->name, str, len)) {
2363 scmac_tobe = maclist[i];
2367 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2368 for (i = 0; i < lenof(compressions)+1; i++) {
2369 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2370 if (in_commasep_string(c->name, str, len)) {
2375 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2376 for (i = 0; i < lenof(compressions)+1; i++) {
2377 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2378 if (in_commasep_string(c->name, str, len)) {
2385 * If we're doing Diffie-Hellman group exchange, start by
2386 * requesting a group.
2388 if (kex == &ssh_diffiehellman_gex) {
2391 logevent("Doing Diffie-Hellman group exchange");
2393 * Work out number of bits. We start with the maximum key
2394 * length of either cipher...
2396 csbits = cscipher_tobe->keylen;
2397 scbits = sccipher_tobe->keylen;
2398 nbits = (csbits > scbits ? csbits : scbits);
2399 /* The keys only have 160-bit entropy, since they're based on
2400 * a SHA-1 hash. So cap the key size at 160 bits. */
2401 if (nbits > 160) nbits = 160;
2403 * ... and then work out how big a DH group we will need to
2404 * allow that much data.
2406 nbits = 512 << ((nbits-1) / 64);
2407 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2408 ssh2_pkt_adduint32(nbits);
2412 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2413 bombout(("expected key exchange group packet from server"));
2416 p = ssh2_pkt_getmp();
2417 g = ssh2_pkt_getmp();
2418 dh_setup_group(p, g);
2419 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2420 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2423 kex_init_value = SSH2_MSG_KEXDH_INIT;
2424 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
2427 logevent("Doing Diffie-Hellman key exchange");
2429 * Now generate and send e for Diffie-Hellman.
2432 ssh2_pkt_init(kex_init_value);
2437 if (pktin.type != kex_reply_value) {
2438 bombout(("expected key exchange reply packet from server"));
2441 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2442 f = ssh2_pkt_getmp();
2443 ssh2_pkt_getstring(&sigdata, &siglen);
2447 sha_string(&exhash, hostkeydata, hostkeylen);
2448 if (kex == &ssh_diffiehellman_gex) {
2449 sha_uint32(&exhash, nbits);
2450 sha_mpint(&exhash, p);
2451 sha_mpint(&exhash, g);
2453 sha_mpint(&exhash, e);
2454 sha_mpint(&exhash, f);
2455 sha_mpint(&exhash, K);
2456 SHA_Final(&exhash, exchange_hash);
2461 debug(("Exchange hash is:\r\n"));
2462 for (i = 0; i < 20; i++)
2463 debug((" %02x", exchange_hash[i]));
2467 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2468 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2469 bombout(("Server failed host key check"));
2474 * Expect SSH2_MSG_NEWKEYS from server.
2477 if (pktin.type != SSH2_MSG_NEWKEYS) {
2478 bombout(("expected new-keys packet from server"));
2483 * Authenticate remote host: verify host key. (We've already
2484 * checked the signature of the exchange hash.)
2486 keystr = hostkey->fmtkey(hkey);
2487 fingerprint = hostkey->fingerprint(hkey);
2488 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2489 keystr, fingerprint);
2490 if (first_kex) { /* don't bother logging this in rekeys */
2491 logevent("Host key fingerprint is:");
2492 logevent(fingerprint);
2496 hostkey->freekey(hkey);
2499 * Send SSH2_MSG_NEWKEYS.
2501 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2505 * Create and initialise session keys.
2507 cscipher = cscipher_tobe;
2508 sccipher = sccipher_tobe;
2511 cscomp = cscomp_tobe;
2512 sccomp = sccomp_tobe;
2513 cscomp->compress_init();
2514 sccomp->decompress_init();
2516 * Set IVs after keys. Here we use the exchange hash from the
2517 * _first_ key exchange.
2520 memcpy(first_exchange_hash, exchange_hash, sizeof(exchange_hash));
2521 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'C', keyspace);
2522 cscipher->setcskey(keyspace);
2523 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'D', keyspace);
2524 sccipher->setsckey(keyspace);
2525 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'A', keyspace);
2526 cscipher->setcsiv(keyspace);
2527 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'B', keyspace);
2528 sccipher->setsciv(keyspace);
2529 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'E', keyspace);
2530 csmac->setcskey(keyspace);
2531 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'F', keyspace);
2532 scmac->setsckey(keyspace);
2535 * If this is the first key exchange phase, we must pass the
2536 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2537 * wants to see it but because it will need time to initialise
2538 * itself before it sees an actual packet. In subsequent key
2539 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2540 * it would only confuse the layer above.
2548 * Now we're encrypting. Begin returning 1 to the protocol main
2549 * function so that other things can run on top of the
2550 * transport. If we ever see a KEXINIT, we must go back to the
2553 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
2556 logevent("Server initiated key re-exchange");
2557 goto begin_key_exchange;
2563 * Add data to an SSH2 channel output buffer.
2565 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2566 if (c->v2.outbufsize <
2567 c->v2.outbuflen + len) {
2569 c->v2.outbuflen + len + 1024;
2570 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2573 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2575 c->v2.outbuflen += len;
2579 * Attempt to send data on an SSH2 channel.
2581 static void ssh2_try_send(struct ssh_channel *c) {
2582 while (c->v2.remwindow > 0 &&
2583 c->v2.outbuflen > 0) {
2584 unsigned len = c->v2.remwindow;
2585 if (len > c->v2.outbuflen)
2586 len = c->v2.outbuflen;
2587 if (len > c->v2.remmaxpkt)
2588 len = c->v2.remmaxpkt;
2589 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2590 ssh2_pkt_adduint32(c->remoteid);
2591 ssh2_pkt_addstring_start();
2592 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2594 c->v2.outbuflen -= len;
2595 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2597 c->v2.remwindow -= len;
2602 * Handle the SSH2 userauth and connection layers.
2604 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2606 static unsigned long remote_winsize;
2607 static unsigned long remote_maxpkt;
2612 * Request userauth protocol, and await a response to it.
2614 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2615 ssh2_pkt_addstring("ssh-userauth");
2617 crWaitUntilV(ispkt);
2618 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2619 bombout(("Server refused user authentication protocol"));
2624 * FIXME: currently we support only password authentication.
2625 * (This places us technically in violation of the SSH2 spec.
2626 * We must fix this.)
2630 * Get a username and a password.
2632 static char username[100];
2633 static char password[100];
2637 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2638 c_write("login as: ", 10);
2641 crWaitUntilV(!ispkt);
2642 while (inlen--) switch (c = *in++) {
2649 c_write("\b \b", 3);
2655 c_write("\b \b", 3);
2664 if (((c >= ' ' && c <= '~') ||
2665 ((unsigned char)c >= 160)) && pos < 40) {
2666 username[pos++] = c;
2673 username[strcspn(username, "\n\r")] = '\0';
2676 strncpy(username, cfg.username, 99);
2677 username[99] = '\0';
2678 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2679 sprintf(stuff, "Using username \"%s\".\r\n", username);
2680 c_write(stuff, strlen(stuff));
2684 if (ssh_get_password) {
2686 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
2687 if (!ssh_get_password(prompt, password, sizeof(password))) {
2689 * get_password failed to get a password (for
2690 * example because one was supplied on the command
2691 * line which has already failed to work).
2694 logevent("No more passwords to try");
2695 ssh_state = SSH_STATE_CLOSED;
2699 c_write("password: ", 10);
2704 crWaitUntilV(!ispkt);
2705 while (inlen--) switch (c = *in++) {
2722 if (((c >= ' ' && c <= '~') ||
2723 ((unsigned char)c >= 160)) && pos < 40)
2724 password[pos++] = c;
2732 * We send the password packet lumped tightly together with
2733 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
2734 * string long enough to make the total length of the two
2735 * packets constant. This should ensure that a passive
2736 * listener doing traffic analyis can't work out the length
2739 * For this to work, we need an assumption about the
2740 * maximum length of the password packet. I think 256 is
2741 * pretty conservative. Anyone using a password longer than
2742 * that probably doesn't have much to worry about from
2743 * people who find out how long their password is!
2745 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2746 ssh2_pkt_addstring(username);
2747 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2748 ssh2_pkt_addstring("password");
2749 ssh2_pkt_addbool(FALSE);
2750 ssh2_pkt_addstring(password);
2753 * We'll include a string that's an exact multiple of the
2754 * cipher block size. If the cipher is NULL for some
2755 * reason, we don't do this trick at all because we gain
2760 ssh2_pkt_init(SSH2_MSG_IGNORE);
2761 ssh2_pkt_addstring_start();
2762 for (i = deferred_len; i <= 256; i += cscipher->blksize) {
2763 for (j = 0; j < cscipher->blksize; j++) {
2764 char c = (char)random_byte();
2765 ssh2_pkt_addstring_data(&c, 1);
2770 ssh2_pkt_defersend();
2772 crWaitUntilV(ispkt);
2773 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2774 c_write("Access denied\r\n", 15);
2775 logevent("Authentication refused");
2781 * Now we're authenticated for the connection protocol. The
2782 * connection protocol will automatically have started at this
2783 * point; there's no need to send SERVICE_REQUEST.
2787 * So now create a channel with a session in it.
2789 mainchan = smalloc(sizeof(struct ssh_channel));
2790 mainchan->localid = 100; /* as good as any */
2791 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2792 ssh2_pkt_addstring("session");
2793 ssh2_pkt_adduint32(mainchan->localid);
2794 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2795 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2797 crWaitUntilV(ispkt);
2798 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
2799 bombout(("Server refused to open a session"));
2801 /* FIXME: error data comes back in FAILURE packet */
2803 if (ssh2_pkt_getuint32() != mainchan->localid) {
2804 bombout(("Server's channel confirmation cited wrong channel"));
2807 mainchan->remoteid = ssh2_pkt_getuint32();
2808 mainchan->type = CHAN_MAINSESSION;
2809 mainchan->closes = 0;
2810 mainchan->v2.remwindow = ssh2_pkt_getuint32();
2811 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
2812 mainchan->v2.outbuffer = NULL;
2813 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
2814 ssh_channels = newtree234(ssh_channelcmp);
2815 add234(ssh_channels, mainchan);
2816 logevent("Opened channel for session");
2819 * Potentially enable X11 forwarding.
2821 if (cfg.x11_forward) {
2822 char proto[20], data[64];
2823 logevent("Requesting X11 forwarding");
2824 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2825 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2826 ssh2_pkt_adduint32(mainchan->remoteid);
2827 ssh2_pkt_addstring("x11-req");
2828 ssh2_pkt_addbool(1); /* want reply */
2829 ssh2_pkt_addbool(0); /* many connections */
2830 ssh2_pkt_addstring(proto);
2831 ssh2_pkt_addstring(data);
2832 ssh2_pkt_adduint32(0); /* screen number */
2836 crWaitUntilV(ispkt);
2837 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2838 unsigned i = ssh2_pkt_getuint32();
2839 struct ssh_channel *c;
2840 c = find234(ssh_channels, &i, ssh_channelfind);
2842 continue; /* nonexistent channel */
2843 c->v2.remwindow += ssh2_pkt_getuint32();
2845 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2847 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2848 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2849 bombout(("Server got confused by X11 forwarding request"));
2852 logevent("X11 forwarding refused");
2854 logevent("X11 forwarding enabled");
2855 ssh_X11_fwd_enabled = TRUE;
2860 * Now allocate a pty for the session.
2863 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2864 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2865 ssh2_pkt_addstring("pty-req");
2866 ssh2_pkt_addbool(1); /* want reply */
2867 ssh2_pkt_addstring(cfg.termtype);
2868 ssh2_pkt_adduint32(cols);
2869 ssh2_pkt_adduint32(rows);
2870 ssh2_pkt_adduint32(0); /* pixel width */
2871 ssh2_pkt_adduint32(0); /* pixel height */
2872 ssh2_pkt_addstring_start();
2873 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2875 ssh_state = SSH_STATE_INTERMED;
2878 crWaitUntilV(ispkt);
2879 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2880 unsigned i = ssh2_pkt_getuint32();
2881 struct ssh_channel *c;
2882 c = find234(ssh_channels, &i, ssh_channelfind);
2884 continue; /* nonexistent channel */
2885 c->v2.remwindow += ssh2_pkt_getuint32();
2887 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2889 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2890 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2891 bombout(("Server got confused by pty request"));
2894 c_write("Server refused to allocate pty\r\n", 32);
2895 ssh_editing = ssh_echoing = 1;
2897 logevent("Allocated pty");
2900 ssh_editing = ssh_echoing = 1;
2904 * Start a shell or a remote command.
2906 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2907 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2908 if (cfg.ssh_subsys) {
2909 ssh2_pkt_addstring("subsystem");
2910 ssh2_pkt_addbool(1); /* want reply */
2911 ssh2_pkt_addstring(cfg.remote_cmd);
2912 } else if (*cfg.remote_cmd) {
2913 ssh2_pkt_addstring("exec");
2914 ssh2_pkt_addbool(1); /* want reply */
2915 ssh2_pkt_addstring(cfg.remote_cmd);
2917 ssh2_pkt_addstring("shell");
2918 ssh2_pkt_addbool(1); /* want reply */
2922 crWaitUntilV(ispkt);
2923 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2924 unsigned i = ssh2_pkt_getuint32();
2925 struct ssh_channel *c;
2926 c = find234(ssh_channels, &i, ssh_channelfind);
2928 continue; /* nonexistent channel */
2929 c->v2.remwindow += ssh2_pkt_getuint32();
2931 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2932 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2933 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2934 bombout(("Server got confused by shell/command request"));
2937 bombout(("Server refused to start a shell/command"));
2940 logevent("Started a shell/command");
2943 ssh_state = SSH_STATE_SESSION;
2947 ssh_special(TS_EOF);
2952 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2955 static int try_send;
2959 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2960 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2963 unsigned i = ssh2_pkt_getuint32();
2964 struct ssh_channel *c;
2965 c = find234(ssh_channels, &i, ssh_channelfind);
2967 continue; /* nonexistent channel */
2968 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2969 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2970 continue; /* extended but not stderr */
2971 ssh2_pkt_getstring(&data, &length);
2974 case CHAN_MAINSESSION:
2975 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2979 x11_send(c->u.x11.s, data, length);
2983 * Enlarge the window again at the remote
2984 * side, just in case it ever runs down and
2985 * they fail to send us any more data.
2987 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2988 ssh2_pkt_adduint32(c->remoteid);
2989 ssh2_pkt_adduint32(length);
2992 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2993 ssh_state = SSH_STATE_CLOSED;
2994 logevent("Received disconnect message");
2996 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2997 continue; /* exit status et al; ignore (FIXME?) */
2998 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2999 unsigned i = ssh2_pkt_getuint32();
3000 struct ssh_channel *c;
3002 c = find234(ssh_channels, &i, ssh_channelfind);
3004 continue; /* nonexistent channel */
3006 if (c->type == CHAN_X11) {
3008 * Remote EOF on an X11 channel means we should
3009 * wrap up and close the channel ourselves.
3011 x11_close(c->u.x11.s);
3014 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
3015 unsigned i = ssh2_pkt_getuint32();
3016 struct ssh_channel *c;
3019 c = find234(ssh_channels, &i, ssh_channelfind);
3021 continue; /* nonexistent channel */
3022 if (c->closes == 0) {
3023 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3024 ssh2_pkt_adduint32(c->remoteid);
3027 /* Do pre-close processing on the channel. */
3029 case CHAN_MAINSESSION:
3030 break; /* nothing to see here, move along */
3034 del234(ssh_channels, c);
3035 sfree(c->v2.outbuffer);
3039 * See if that was the last channel left open.
3041 c = first234(ssh_channels, &e);
3043 logevent("All channels closed. Disconnecting");
3044 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3045 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3046 ssh2_pkt_addstring("All open channels closed");
3047 ssh2_pkt_addstring("en"); /* language tag */
3049 ssh_state = SSH_STATE_CLOSED;
3052 continue; /* remote sends close; ignore (FIXME) */
3053 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3054 unsigned i = ssh2_pkt_getuint32();
3055 struct ssh_channel *c;
3056 c = find234(ssh_channels, &i, ssh_channelfind);
3058 continue; /* nonexistent channel */
3059 mainchan->v2.remwindow += ssh2_pkt_getuint32();
3061 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3065 struct ssh_channel *c;
3066 ssh2_pkt_getstring(&type, &typelen);
3067 c = smalloc(sizeof(struct ssh_channel));
3069 if (typelen == 3 && !memcmp(type, "x11", 3)) {
3070 if (!ssh_X11_fwd_enabled)
3071 error = "X11 forwarding is not enabled";
3072 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
3073 error = "Unable to open an X11 connection";
3078 error = "Unsupported channel type requested";
3081 c->remoteid = ssh2_pkt_getuint32();
3083 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3084 ssh2_pkt_adduint32(c->remoteid);
3085 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3086 ssh2_pkt_addstring(error);
3087 ssh2_pkt_addstring("en"); /* language tag */
3091 struct ssh_channel *d;
3095 for (i=1, d = first234(ssh_channels, &e); d;
3098 break; /* found a free number */
3103 c->v2.remwindow = ssh2_pkt_getuint32();
3104 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3105 c->v2.outbuffer = NULL;
3106 c->v2.outbuflen = c->v2.outbufsize = 0;
3107 add234(ssh_channels, c);
3108 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3109 ssh2_pkt_adduint32(c->remoteid);
3110 ssh2_pkt_adduint32(c->localid);
3111 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3112 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3116 bombout(("Strange packet received: type %d", pktin.type));
3121 * We have spare data. Add it to the channel buffer.
3123 ssh2_add_channel_data(mainchan, in, inlen);
3128 struct ssh_channel *c;
3130 * Try to send data on all channels if we can.
3132 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3141 * Handle the top-level SSH2 protocol.
3143 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3145 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3147 do_ssh2_authconn(in, inlen, ispkt);
3151 * Called to set up the connection.
3153 * Returns an error message, or NULL on success.
3155 static char *ssh_init (char *host, int port, char **realhost) {
3159 if(crypto_startup() == 0)
3160 return "Microsoft high encryption pack not installed!";
3167 p = connect_to_host(host, port, realhost);
3175 * Called to send data down the Telnet connection.
3177 static void ssh_send (char *buf, int len) {
3178 if (s == NULL || ssh_protocol == NULL)
3181 ssh_protocol(buf, len, 0);
3185 * Called to set the size of the window from SSH's POV.
3187 static void ssh_size(void) {
3188 switch (ssh_state) {
3189 case SSH_STATE_BEFORE_SIZE:
3190 case SSH_STATE_PREPACKET:
3191 case SSH_STATE_CLOSED:
3192 break; /* do nothing */
3193 case SSH_STATE_INTERMED:
3194 size_needed = TRUE; /* buffer for later */
3196 case SSH_STATE_SESSION:
3198 if (ssh_version == 1) {
3199 send_packet(SSH1_CMSG_WINDOW_SIZE,
3200 PKT_INT, rows, PKT_INT, cols,
3201 PKT_INT, 0, PKT_INT, 0, PKT_END);
3203 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3204 ssh2_pkt_adduint32(mainchan->remoteid);
3205 ssh2_pkt_addstring("window-change");
3206 ssh2_pkt_addbool(0);
3207 ssh2_pkt_adduint32(cols);
3208 ssh2_pkt_adduint32(rows);
3209 ssh2_pkt_adduint32(0);
3210 ssh2_pkt_adduint32(0);
3219 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3220 * can send an EOF and collect resulting output (e.g. `plink
3223 static void ssh_special (Telnet_Special code) {
3224 if (code == TS_EOF) {
3225 if (ssh_state != SSH_STATE_SESSION) {
3227 * Buffer the EOF in case we are pre-SESSION, so we can
3228 * send it as soon as we reach SESSION.
3234 if (ssh_version == 1) {
3235 send_packet(SSH1_CMSG_EOF, PKT_END);
3237 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
3238 ssh2_pkt_adduint32(mainchan->remoteid);
3241 logevent("Sent EOF message");
3242 } else if (code == TS_PING) {
3243 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3245 if (ssh_version == 1) {
3246 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3248 ssh2_pkt_init(SSH2_MSG_IGNORE);
3249 ssh2_pkt_addstring_start();
3257 static Socket ssh_socket(void) { return s; }
3259 static int ssh_sendok(void) { return ssh_send_ok; }
3261 static int ssh_ldisc(int option) {
3262 if (option == LD_ECHO) return ssh_echoing;
3263 if (option == LD_EDIT) return ssh_editing;
3267 Backend ssh_backend = {