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 ssh2_ciphers ssh2_3des;
169 extern const struct ssh_cipher ssh_des;
170 extern const struct ssh2_ciphers ssh2_aes;
171 extern const struct ssh_cipher ssh_blowfish_ssh1;
172 extern const struct ssh2_ciphers ssh2_blowfish;
174 extern char *x11_init (Socket *, char *, void *);
175 extern void x11_close (Socket);
176 extern void x11_send (Socket , char *, int);
177 extern void x11_invent_auth(char *, int, char *, int);
180 * Ciphers for SSH2. We miss out single-DES because it isn't
181 * supported; also 3DES and Blowfish are both done differently from
182 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
183 * endianness and different-sized keys.)
185 const static struct ssh2_ciphers *ciphers[] = {
191 extern const struct ssh_kex ssh_diffiehellman;
192 extern const struct ssh_kex ssh_diffiehellman_gex;
193 const static struct ssh_kex *kex_algs[] = {
194 #ifdef DO_DIFFIE_HELLMAN_GEX
195 &ssh_diffiehellman_gex,
197 &ssh_diffiehellman };
199 extern const struct ssh_signkey ssh_dss;
200 const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss };
202 extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
204 static void nullmac_key(unsigned char *key) { }
205 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
206 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
207 const static struct ssh_mac ssh_mac_none = {
208 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
210 const static struct ssh_mac *macs[] = {
211 &ssh_sha1, &ssh_md5, &ssh_mac_none };
212 const static struct ssh_mac *buggymacs[] = {
213 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
215 static void ssh_comp_none_init(void) { }
216 static int ssh_comp_none_block(unsigned char *block, int len,
217 unsigned char **outblock, int *outlen) {
220 const static struct ssh_compress ssh_comp_none = {
222 ssh_comp_none_init, ssh_comp_none_block,
223 ssh_comp_none_init, ssh_comp_none_block
225 extern const struct ssh_compress ssh_zlib;
226 const static struct ssh_compress *compressions[] = {
227 &ssh_zlib, &ssh_comp_none };
229 enum { /* channel types */
236 * 2-3-4 tree storing channels.
239 unsigned remoteid, localid;
242 struct ssh2_data_channel {
243 unsigned char *outbuffer;
244 unsigned outbuflen, outbufsize;
245 unsigned remwindow, remmaxpkt;
248 struct ssh_agent_channel {
249 unsigned char *message;
250 unsigned char msglen[4];
251 int lensofar, totallen;
253 struct ssh_x11_channel {
268 static SHA_State exhash, exhashbase;
270 static Socket s = NULL;
272 static unsigned char session_key[32];
273 static int ssh1_compressing;
274 static int ssh_agentfwd_enabled;
275 static int ssh_X11_fwd_enabled;
276 static const struct ssh_cipher *cipher = NULL;
277 static const struct ssh2_cipher *cscipher = NULL;
278 static const struct ssh2_cipher *sccipher = NULL;
279 static const struct ssh_mac *csmac = NULL;
280 static const struct ssh_mac *scmac = NULL;
281 static const struct ssh_compress *cscomp = NULL;
282 static const struct ssh_compress *sccomp = NULL;
283 static const struct ssh_kex *kex = NULL;
284 static const struct ssh_signkey *hostkey = NULL;
285 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
287 static char *savedhost;
288 static int savedport;
289 static int ssh_send_ok;
290 static int ssh_echoing, ssh_editing;
292 static tree234 *ssh_channels; /* indexed by local id */
293 static struct ssh_channel *mainchan; /* primary session channel */
297 SSH_STATE_BEFORE_SIZE,
301 } ssh_state = SSH_STATE_PREPACKET;
303 static int size_needed = FALSE, eof_needed = FALSE;
305 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
306 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
307 static unsigned char *deferred_send_data = NULL;
308 static int deferred_len = 0, deferred_size = 0;
310 static int ssh_version;
311 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
312 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
313 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
314 static void ssh_size(void);
315 static void ssh_special (Telnet_Special);
316 static void ssh2_try_send(struct ssh_channel *c);
317 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
319 static int (*s_rdpkt)(unsigned char **data, int *datalen);
321 static struct rdpkt1_state_tag {
322 long len, pad, biglen, to_read;
323 unsigned long realcrc, gotcrc;
329 static struct rdpkt2_state_tag {
330 long len, pad, payload, packetlen, maclen;
333 unsigned long incoming_sequence;
336 static int ssh_channelcmp(void *av, void *bv) {
337 struct ssh_channel *a = (struct ssh_channel *)av;
338 struct ssh_channel *b = (struct ssh_channel *)bv;
339 if (a->localid < b->localid) return -1;
340 if (a->localid > b->localid) return +1;
343 static int ssh_channelfind(void *av, void *bv) {
344 unsigned *a = (unsigned *)av;
345 struct ssh_channel *b = (struct ssh_channel *)bv;
346 if (*a < b->localid) return -1;
347 if (*a > b->localid) return +1;
351 static void c_write (char *buf, int len) {
352 if ((flags & FLAG_STDERR)) {
354 for (i = 0; i < len; i++)
356 fputc(buf[i], stderr);
359 from_backend(1, buf, len);
363 * Collect incoming data in the incoming packet buffer.
364 * Decipher and verify the packet when it is completely read.
365 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
366 * Update the *data and *datalen variables.
367 * Return the additional nr of bytes needed, or 0 when
368 * a complete packet is available.
370 static int ssh1_rdpkt(unsigned char **data, int *datalen)
372 struct rdpkt1_state_tag *st = &rdpkt1_state;
381 for (st->i = st->len = 0; st->i < 4; st->i++) {
382 while ((*datalen) == 0)
384 st->len = (st->len << 8) + **data;
385 (*data)++, (*datalen)--;
389 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
390 st->len = 0x300; /* big enough to carry to end */
394 st->pad = 8 - (st->len % 8);
395 st->biglen = st->len + st->pad;
396 pktin.length = st->len - 5;
398 if (pktin.maxlen < st->biglen) {
399 pktin.maxlen = st->biglen;
400 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
401 srealloc(pktin.data, st->biglen+APIEXTRA));
403 fatalbox("Out of memory");
406 st->to_read = st->biglen;
408 while (st->to_read > 0) {
409 st->chunk = st->to_read;
410 while ((*datalen) == 0)
411 crReturn(st->to_read);
412 if (st->chunk > (*datalen))
413 st->chunk = (*datalen);
414 memcpy(st->p, *data, st->chunk);
416 *datalen -= st->chunk;
418 st->to_read -= st->chunk;
422 cipher->decrypt(pktin.data, st->biglen);
424 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
425 for (st->i = 0; st->i < st->biglen; st->i++)
426 debug((" %02x", (unsigned char)pktin.data[st->i]));
430 st->realcrc = crc32(pktin.data, st->biglen-4);
431 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
432 if (st->gotcrc != st->realcrc) {
433 bombout(("Incorrect CRC received on packet"));
437 pktin.body = pktin.data + st->pad + 1;
439 if (ssh1_compressing) {
440 unsigned char *decompblk;
444 debug(("Packet payload pre-decompression:\n"));
445 for (i = -1; i < pktin.length; i++)
446 debug((" %02x", (unsigned char)pktin.body[i]));
449 zlib_decompress_block(pktin.body-1, pktin.length+1,
450 &decompblk, &decomplen);
452 if (pktin.maxlen < st->pad + decomplen) {
453 pktin.maxlen = st->pad + decomplen;
454 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
455 pktin.body = pktin.data + st->pad + 1;
457 fatalbox("Out of memory");
460 memcpy(pktin.body-1, decompblk, decomplen);
462 pktin.length = decomplen-1;
464 debug(("Packet payload post-decompression:\n"));
465 for (i = -1; i < pktin.length; i++)
466 debug((" %02x", (unsigned char)pktin.body[i]));
471 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
472 pktin.type == SSH1_SMSG_STDERR_DATA ||
473 pktin.type == SSH1_MSG_DEBUG ||
474 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
475 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
476 long strlen = GET_32BIT(pktin.body);
477 if (strlen + 4 != pktin.length) {
478 bombout(("Received data packet with bogus string length"));
483 pktin.type = pktin.body[-1];
485 if (pktin.type == SSH1_MSG_DEBUG) {
486 /* log debug message */
488 int strlen = GET_32BIT(pktin.body);
489 strcpy(buf, "Remote: ");
490 if (strlen > 70) strlen = 70;
491 memcpy(buf+8, pktin.body+4, strlen);
492 buf[8+strlen] = '\0';
495 } else if (pktin.type == SSH1_MSG_IGNORE) {
503 static int ssh2_rdpkt(unsigned char **data, int *datalen)
505 struct rdpkt2_state_tag *st = &rdpkt2_state;
513 st->cipherblk = sccipher->blksize;
516 if (st->cipherblk < 8)
519 if (pktin.maxlen < st->cipherblk) {
520 pktin.maxlen = st->cipherblk;
521 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
522 srealloc(pktin.data, st->cipherblk+APIEXTRA));
524 fatalbox("Out of memory");
528 * Acquire and decrypt the first block of the packet. This will
529 * contain the length and padding details.
531 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
532 while ((*datalen) == 0)
533 crReturn(st->cipherblk-st->i);
534 pktin.data[st->i] = *(*data)++;
538 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
543 sccipher->decrypt(pktin.data, st->cipherblk);
546 * Now get the length and padding figures.
548 st->len = GET_32BIT(pktin.data);
549 st->pad = pktin.data[4];
552 * This enables us to deduce the payload length.
554 st->payload = st->len - st->pad - 1;
556 pktin.length = st->payload + 5;
559 * So now we can work out the total packet length.
561 st->packetlen = st->len + 4;
562 st->maclen = scmac ? scmac->len : 0;
565 * Adjust memory allocation if packet is too big.
567 if (pktin.maxlen < st->packetlen+st->maclen) {
568 pktin.maxlen = st->packetlen+st->maclen;
569 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
570 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
572 fatalbox("Out of memory");
576 * Read and decrypt the remainder of the packet.
578 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
579 while ((*datalen) == 0)
580 crReturn(st->packetlen + st->maclen - st->i);
581 pktin.data[st->i] = *(*data)++;
584 /* Decrypt everything _except_ the MAC. */
586 sccipher->decrypt(pktin.data + st->cipherblk,
587 st->packetlen - st->cipherblk);
590 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
591 for (st->i = 0; st->i < st->packetlen; st->i++)
592 debug((" %02x", (unsigned char)pktin.data[st->i]));
599 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
600 bombout(("Incorrect MAC received on packet"));
603 st->incoming_sequence++; /* whether or not we MACed */
606 * Decompress packet payload.
609 unsigned char *newpayload;
611 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
612 &newpayload, &newlen)) {
613 if (pktin.maxlen < newlen+5) {
614 pktin.maxlen = newlen+5;
615 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
616 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
618 fatalbox("Out of memory");
620 pktin.length = 5 + newlen;
621 memcpy(pktin.data+5, newpayload, newlen);
623 debug(("Post-decompression payload:\r\n"));
624 for (st->i = 0; st->i < newlen; st->i++)
625 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
634 pktin.type = pktin.data[5];
636 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
637 goto next_packet; /* FIXME: print DEBUG message */
642 static void ssh1_pktout_size(int len) {
645 len += 5; /* type and CRC */
649 pktout.length = len-5;
650 if (pktout.maxlen < biglen) {
651 pktout.maxlen = biglen;
653 /* Allocate enough buffer space for extra block
654 * for MS CryptEncrypt() */
655 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
656 srealloc(pktout.data, biglen+12));
658 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
659 srealloc(pktout.data, biglen+4));
662 fatalbox("Out of memory");
664 pktout.body = pktout.data+4+pad+1;
667 static void s_wrpkt_start(int type, int len) {
668 ssh1_pktout_size(len);
672 static void s_wrpkt(void) {
673 int pad, len, biglen, i;
676 pktout.body[-1] = pktout.type;
678 if (ssh1_compressing) {
679 unsigned char *compblk;
682 debug(("Packet payload pre-compression:\n"));
683 for (i = -1; i < pktout.length; i++)
684 debug((" %02x", (unsigned char)pktout.body[i]));
687 zlib_compress_block(pktout.body-1, pktout.length+1,
689 ssh1_pktout_size(complen-1);
690 memcpy(pktout.body-1, compblk, complen);
693 debug(("Packet payload post-compression:\n"));
694 for (i = -1; i < pktout.length; i++)
695 debug((" %02x", (unsigned char)pktout.body[i]));
700 len = pktout.length + 5; /* type and CRC */
704 for (i=0; i<pad; i++)
705 pktout.data[i+4] = random_byte();
706 crc = crc32(pktout.data+4, biglen-4);
707 PUT_32BIT(pktout.data+biglen, crc);
708 PUT_32BIT(pktout.data, len);
711 debug(("Sending packet len=%d\r\n", biglen+4));
712 for (i = 0; i < biglen+4; i++)
713 debug((" %02x", (unsigned char)pktout.data[i]));
717 cipher->encrypt(pktout.data+4, biglen);
719 sk_write(s, pktout.data, biglen+4);
723 * Construct a packet with the specified contents and
724 * send it to the server.
726 static void send_packet(int pkttype, ...)
729 unsigned char *p, *argp, argchar;
730 unsigned long argint;
731 int pktlen, argtype, arglen;
735 va_start(args, pkttype);
736 while ((argtype = va_arg(args, int)) != PKT_END) {
739 (void) va_arg(args, int);
743 (void) va_arg(args, char);
747 (void) va_arg(args, unsigned char *);
748 arglen = va_arg(args, int);
752 argp = va_arg(args, unsigned char *);
753 arglen = strlen(argp);
754 pktlen += 4 + arglen;
757 bn = va_arg(args, Bignum);
758 pktlen += ssh1_bignum_length(bn);
766 s_wrpkt_start(pkttype, pktlen);
769 va_start(args, pkttype);
770 while ((argtype = va_arg(args, int)) != PKT_END) {
773 argint = va_arg(args, int);
774 PUT_32BIT(p, argint);
778 argchar = va_arg(args, unsigned char);
783 argp = va_arg(args, unsigned char *);
784 arglen = va_arg(args, int);
785 memcpy(p, argp, arglen);
789 argp = va_arg(args, unsigned char *);
790 arglen = strlen(argp);
791 PUT_32BIT(p, arglen);
792 memcpy(p + 4, argp, arglen);
796 bn = va_arg(args, Bignum);
797 p += ssh1_write_bignum(p, bn);
806 static int ssh_versioncmp(char *a, char *b) {
808 unsigned long av, bv;
810 av = strtoul(a, &ae, 10);
811 bv = strtoul(b, &be, 10);
812 if (av != bv) return (av < bv ? -1 : +1);
813 if (*ae == '.') ae++;
814 if (*be == '.') be++;
815 av = strtoul(ae, &ae, 10);
816 bv = strtoul(be, &be, 10);
817 if (av != bv) return (av < bv ? -1 : +1);
823 * Utility routines for putting an SSH-protocol `string' and
824 * `uint32' into a SHA state.
827 static void sha_string(SHA_State *s, void *str, int len) {
828 unsigned char lenblk[4];
829 PUT_32BIT(lenblk, len);
830 SHA_Bytes(s, lenblk, 4);
831 SHA_Bytes(s, str, len);
834 static void sha_uint32(SHA_State *s, unsigned i) {
835 unsigned char intblk[4];
836 PUT_32BIT(intblk, i);
837 SHA_Bytes(s, intblk, 4);
841 * SSH2 packet construction functions.
843 static void ssh2_pkt_ensure(int length) {
844 if (pktout.maxlen < length) {
845 pktout.maxlen = length + 256;
846 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
847 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
849 fatalbox("Out of memory");
852 static void ssh2_pkt_adddata(void *data, int len) {
853 pktout.length += len;
854 ssh2_pkt_ensure(pktout.length);
855 memcpy(pktout.data+pktout.length-len, data, len);
857 static void ssh2_pkt_addbyte(unsigned char byte) {
858 ssh2_pkt_adddata(&byte, 1);
860 static void ssh2_pkt_init(int pkt_type) {
862 ssh2_pkt_addbyte((unsigned char)pkt_type);
864 static void ssh2_pkt_addbool(unsigned char value) {
865 ssh2_pkt_adddata(&value, 1);
867 static void ssh2_pkt_adduint32(unsigned long value) {
870 ssh2_pkt_adddata(x, 4);
872 static void ssh2_pkt_addstring_start(void) {
873 ssh2_pkt_adduint32(0);
874 pktout.savedpos = pktout.length;
876 static void ssh2_pkt_addstring_str(char *data) {
877 ssh2_pkt_adddata(data, strlen(data));
878 PUT_32BIT(pktout.data + pktout.savedpos - 4,
879 pktout.length - pktout.savedpos);
881 static void ssh2_pkt_addstring_data(char *data, int len) {
882 ssh2_pkt_adddata(data, len);
883 PUT_32BIT(pktout.data + pktout.savedpos - 4,
884 pktout.length - pktout.savedpos);
886 static void ssh2_pkt_addstring(char *data) {
887 ssh2_pkt_addstring_start();
888 ssh2_pkt_addstring_str(data);
890 static char *ssh2_mpint_fmt(Bignum b, int *len) {
892 int i, n = (ssh1_bignum_bitcount(b)+7)/8;
895 fatalbox("out of memory");
897 for (i = 1; i <= n; i++)
898 p[i] = bignum_byte(b, n-i);
900 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
902 memmove(p, p+i, n+1-i);
906 static void ssh2_pkt_addmp(Bignum b) {
909 p = ssh2_mpint_fmt(b, &len);
910 ssh2_pkt_addstring_start();
911 ssh2_pkt_addstring_data(p, len);
916 * Construct an SSH2 final-form packet: compress it, encrypt it,
917 * put the MAC on it. Final packet, ready to be sent, is stored in
918 * pktout.data. Total length is returned.
920 static int ssh2_pkt_construct(void) {
921 int cipherblk, maclen, padding, i;
922 static unsigned long outgoing_sequence = 0;
925 * Compress packet payload.
928 debug(("Pre-compression payload:\r\n"));
929 for (i = 5; i < pktout.length; i++)
930 debug((" %02x", (unsigned char)pktout.data[i]));
934 unsigned char *newpayload;
936 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
937 &newpayload, &newlen)) {
939 ssh2_pkt_adddata(newpayload, newlen);
945 * Add padding. At least four bytes, and must also bring total
946 * length (minus MAC) up to a multiple of the block size.
948 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
949 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
951 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
952 maclen = csmac ? csmac->len : 0;
953 ssh2_pkt_ensure(pktout.length + padding + maclen);
954 pktout.data[4] = padding;
955 for (i = 0; i < padding; i++)
956 pktout.data[pktout.length + i] = random_byte();
957 PUT_32BIT(pktout.data, pktout.length + padding - 4);
959 csmac->generate(pktout.data, pktout.length + padding,
961 outgoing_sequence++; /* whether or not we MACed */
964 debug(("Sending packet len=%d\r\n", pktout.length+padding));
965 for (i = 0; i < pktout.length+padding; i++)
966 debug((" %02x", (unsigned char)pktout.data[i]));
971 cscipher->encrypt(pktout.data, pktout.length + padding);
973 /* Ready-to-send packet starts at pktout.data. We return length. */
974 return pktout.length + padding + maclen;
978 * Construct and send an SSH2 packet immediately.
980 static void ssh2_pkt_send(void) {
981 int len = ssh2_pkt_construct();
982 sk_write(s, pktout.data, len);
986 * Construct an SSH2 packet and add it to a deferred data block.
987 * Useful for sending multiple packets in a single sk_write() call,
988 * to prevent a traffic-analysing listener from being able to work
989 * out the length of any particular packet (such as the password
992 * Note that because SSH2 sequence-numbers its packets, this can
993 * NOT be used as an m4-style `defer' allowing packets to be
994 * constructed in one order and sent in another.
996 static void ssh2_pkt_defer(void) {
997 int len = ssh2_pkt_construct();
998 if (deferred_len + len > deferred_size) {
999 deferred_size = deferred_len + len + 128;
1000 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1002 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1003 deferred_len += len;
1007 * Send the whole deferred data block constructed by
1010 static void ssh2_pkt_defersend(void) {
1011 sk_write(s, deferred_send_data, deferred_len);
1012 deferred_len = deferred_size = 0;
1013 sfree(deferred_send_data);
1014 deferred_send_data = NULL;
1018 void bndebug(char *string, Bignum b) {
1021 p = ssh2_mpint_fmt(b, &len);
1022 debug(("%s", string));
1023 for (i = 0; i < len; i++)
1024 debug((" %02x", p[i]));
1030 static void sha_mpint(SHA_State *s, Bignum b) {
1033 p = ssh2_mpint_fmt(b, &len);
1034 sha_string(s, p, len);
1039 * SSH2 packet decode functions.
1041 static unsigned long ssh2_pkt_getuint32(void) {
1042 unsigned long value;
1043 if (pktin.length - pktin.savedpos < 4)
1044 return 0; /* arrgh, no way to decline (FIXME?) */
1045 value = GET_32BIT(pktin.data+pktin.savedpos);
1046 pktin.savedpos += 4;
1049 static void ssh2_pkt_getstring(char **p, int *length) {
1051 if (pktin.length - pktin.savedpos < 4)
1053 *length = GET_32BIT(pktin.data+pktin.savedpos);
1054 pktin.savedpos += 4;
1055 if (pktin.length - pktin.savedpos < *length)
1057 *p = pktin.data+pktin.savedpos;
1058 pktin.savedpos += *length;
1060 static Bignum ssh2_pkt_getmp(void) {
1065 ssh2_pkt_getstring(&p, &length);
1069 bombout(("internal error: Can't handle negative mpints"));
1072 b = bignum_from_bytes(p, length);
1076 static int do_ssh_init(unsigned char c) {
1078 static char version[10];
1079 static char vstring[80];
1080 static char vlog[sizeof(vstring)+20];
1085 /* Search for the string "SSH-" in the input. */
1088 static const int transS[] = { 1, 2, 2, 1 };
1089 static const int transH[] = { 0, 0, 3, 0 };
1090 static const int transminus[] = { 0, 0, 0, -1 };
1091 if (c == 'S') i = transS[i];
1092 else if (c == 'H') i = transH[i];
1093 else if (c == '-') i = transminus[i];
1097 crReturn(1); /* get another character */
1100 strcpy(vstring, "SSH-");
1104 crReturn(1); /* get another char */
1105 if (vsp < vstring+sizeof(vstring)-1)
1111 } else if (i < sizeof(version)-1)
1118 ssh_agentfwd_enabled = FALSE;
1119 rdpkt2_state.incoming_sequence = 0;
1122 sprintf(vlog, "Server version: %s", vstring);
1123 vlog[strcspn(vlog, "\r\n")] = '\0';
1127 * Server version "1.99" means we can choose whether we use v1
1128 * or v2 protocol. Choice is based on cfg.sshprot.
1130 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1132 * This is a v2 server. Begin v2 protocol.
1134 char *verstring = "SSH-2.0-PuTTY";
1135 SHA_Init(&exhashbase);
1137 * Hash our version string and their version string.
1139 sha_string(&exhashbase, verstring, strlen(verstring));
1140 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1141 sprintf(vstring, "%s\n", verstring);
1142 sprintf(vlog, "We claim version: %s", verstring);
1144 logevent("Using SSH protocol version 2");
1145 sk_write(s, vstring, strlen(vstring));
1146 ssh_protocol = ssh2_protocol;
1148 s_rdpkt = ssh2_rdpkt;
1151 * This is a v1 server. Begin v1 protocol.
1153 sprintf(vstring, "SSH-%s-PuTTY\n",
1154 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1155 sprintf(vlog, "We claim version: %s", vstring);
1156 vlog[strcspn(vlog, "\r\n")] = '\0';
1158 logevent("Using SSH protocol version 1");
1159 sk_write(s, vstring, strlen(vstring));
1160 ssh_protocol = ssh1_protocol;
1162 s_rdpkt = ssh1_rdpkt;
1164 ssh_state = SSH_STATE_BEFORE_SIZE;
1169 static void ssh_gotdata(unsigned char *data, int datalen)
1174 * To begin with, feed the characters one by one to the
1175 * protocol initialisation / selection function do_ssh_init().
1176 * When that returns 0, we're done with the initial greeting
1177 * exchange and can move on to packet discipline.
1182 crReturnV; /* more data please */
1183 ret = do_ssh_init(*data);
1190 * We emerge from that loop when the initial negotiation is
1191 * over and we have selected an s_rdpkt function. Now pass
1192 * everything to s_rdpkt, and then pass the resulting packets
1193 * to the proper protocol handler.
1198 while (datalen > 0) {
1199 if ( s_rdpkt(&data, &datalen) == 0 ) {
1200 ssh_protocol(NULL, 0, 1);
1201 if (ssh_state == SSH_STATE_CLOSED) {
1211 static int ssh_receive(Socket skt, int urgent, char *data, int len) {
1213 /* A socket error has occurred. */
1214 ssh_state = SSH_STATE_CLOSED;
1217 connection_fatal(data);
1220 /* Connection has closed. */
1221 ssh_state = SSH_STATE_CLOSED;
1226 ssh_gotdata (data, len);
1227 if (ssh_state == SSH_STATE_CLOSED) {
1238 * Connect to specified host and port.
1239 * Returns an error message, or NULL on success.
1240 * Also places the canonical host name into `realhost'.
1242 static char *connect_to_host(char *host, int port, char **realhost)
1251 savedhost = smalloc(1+strlen(host));
1253 fatalbox("Out of memory");
1254 strcpy(savedhost, host);
1257 port = 22; /* default ssh port */
1270 addr = sk_namelookup(host, realhost);
1271 if ( (err = sk_addr_error(addr)) )
1281 s = sk_new(addr, port, 0, 1, ssh_receive);
1282 if ( (err = sk_socket_error(s)) )
1286 sk_write(s, "connect ", 8);
1287 sk_write(s, FWhost, strlen(FWhost));
1290 sprintf(buf, " %d\n", FWport);
1291 sk_write(s, buf, strlen(buf));
1299 * Handle the key exchange and user authentication phases.
1301 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1304 unsigned char *rsabuf, *keystr1, *keystr2;
1305 unsigned char cookie[8];
1306 struct RSAKey servkey, hostkey;
1307 struct MD5Context md5c;
1308 static unsigned long supported_ciphers_mask, supported_auths_mask;
1309 static int tried_publickey;
1310 static unsigned char session_id[16];
1312 static char username[100];
1316 if (!ispkt) crWaitUntil(ispkt);
1318 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1319 bombout(("Public key packet not received"));
1323 logevent("Received public keys");
1325 memcpy(cookie, pktin.body, 8);
1327 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1328 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1331 * Log the host key fingerprint.
1335 logevent("Host key fingerprint is:");
1336 strcpy(logmsg, " ");
1337 hostkey.comment = NULL;
1338 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1343 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1344 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1347 MD5Update(&md5c, keystr2, hostkey.bytes);
1348 MD5Update(&md5c, keystr1, servkey.bytes);
1349 MD5Update(&md5c, pktin.body, 8);
1350 MD5Final(session_id, &md5c);
1352 for (i=0; i<32; i++)
1353 session_key[i] = random_byte();
1355 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1357 rsabuf = smalloc(len);
1359 fatalbox("Out of memory");
1362 * Verify the host key.
1366 * First format the key into a string.
1368 int len = rsastr_len(&hostkey);
1369 char fingerprint[100];
1370 char *keystr = smalloc(len);
1372 fatalbox("Out of memory");
1373 rsastr_fmt(keystr, &hostkey);
1374 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1375 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1379 for (i=0; i<32; i++) {
1380 rsabuf[i] = session_key[i];
1382 rsabuf[i] ^= session_id[i];
1385 if (hostkey.bytes > servkey.bytes) {
1386 rsaencrypt(rsabuf, 32, &servkey);
1387 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1389 rsaencrypt(rsabuf, 32, &hostkey);
1390 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1393 logevent("Encrypted session key");
1395 switch (cfg.cipher) {
1396 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break;
1397 case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break;
1398 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break;
1400 c_write("AES not supported in SSH1, falling back to 3DES\r\n", 49);
1401 cipher_type = SSH_CIPHER_3DES;
1404 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1405 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1406 cipher_type = SSH_CIPHER_3DES;
1408 switch (cipher_type) {
1409 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1410 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1411 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1414 send_packet(SSH1_CMSG_SESSION_KEY,
1415 PKT_CHAR, cipher_type,
1416 PKT_DATA, cookie, 8,
1417 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1418 PKT_DATA, rsabuf, len,
1422 logevent("Trying to enable encryption...");
1426 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1427 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1429 cipher->sesskey(session_key);
1433 if (pktin.type != SSH1_SMSG_SUCCESS) {
1434 bombout(("Encryption not successfully enabled"));
1438 logevent("Successfully started encryption");
1444 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1445 c_write("login as: ", 10);
1448 crWaitUntil(!ispkt);
1449 while (inlen--) switch (c = *in++) {
1456 c_write("\b \b", 3);
1462 c_write("\b \b", 3);
1471 if (((c >= ' ' && c <= '~') ||
1472 ((unsigned char)c >= 160)) && pos < 40) {
1473 username[pos++] = c;
1480 username[strcspn(username, "\n\r")] = '\0';
1482 strncpy(username, cfg.username, 99);
1483 username[99] = '\0';
1486 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1488 char userlog[22+sizeof(username)];
1489 sprintf(userlog, "Sent username \"%s\"", username);
1491 if (flags & FLAG_INTERACTIVE &&
1492 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1493 strcat(userlog, "\r\n");
1494 c_write(userlog, strlen(userlog));
1501 tried_publickey = 0;
1503 while (pktin.type == SSH1_SMSG_FAILURE) {
1504 static char password[100];
1505 static char prompt[200];
1508 static int pwpkt_type;
1510 * Show password prompt, having first obtained it via a TIS
1511 * or CryptoCard exchange if we're doing TIS or CryptoCard
1514 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1515 if (agent_exists()) {
1517 * Attempt RSA authentication using Pageant.
1519 static unsigned char request[5], *response, *p;
1520 static int responselen;
1521 static int i, nkeys;
1522 static int authed = FALSE;
1525 logevent("Pageant is running. Requesting keys.");
1527 /* Request the keys held by the agent. */
1528 PUT_32BIT(request, 1);
1529 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1530 agent_query(request, 5, &r, &responselen);
1531 response = (unsigned char *)r;
1534 nkeys = GET_32BIT(p); p += 4;
1535 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1537 for (i = 0; i < nkeys; i++) {
1538 static struct RSAKey key;
1539 static Bignum challenge;
1540 static char *commentp;
1541 static int commentlen;
1543 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1546 p += ssh1_read_bignum(p, &key.exponent);
1547 p += ssh1_read_bignum(p, &key.modulus);
1548 commentlen = GET_32BIT(p); p += 4;
1549 commentp = p; p += commentlen;
1550 send_packet(SSH1_CMSG_AUTH_RSA,
1551 PKT_BIGNUM, key.modulus, PKT_END);
1553 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1554 logevent("Key refused");
1557 logevent("Received RSA challenge");
1558 ssh1_read_bignum(pktin.body, &challenge);
1560 char *agentreq, *q, *ret;
1562 len = 1 + 4; /* message type, bit count */
1563 len += ssh1_bignum_length(key.exponent);
1564 len += ssh1_bignum_length(key.modulus);
1565 len += ssh1_bignum_length(challenge);
1566 len += 16; /* session id */
1567 len += 4; /* response format */
1568 agentreq = smalloc(4 + len);
1569 PUT_32BIT(agentreq, len);
1571 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1572 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1574 q += ssh1_write_bignum(q, key.exponent);
1575 q += ssh1_write_bignum(q, key.modulus);
1576 q += ssh1_write_bignum(q, challenge);
1577 memcpy(q, session_id, 16); q += 16;
1578 PUT_32BIT(q, 1); /* response format */
1579 agent_query(agentreq, len+4, &ret, &retlen);
1582 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1583 logevent("Sending Pageant's response");
1584 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1585 PKT_DATA, ret+5, 16, PKT_END);
1588 if (pktin.type == SSH1_SMSG_SUCCESS) {
1589 logevent("Pageant's response accepted");
1590 if (flags & FLAG_VERBOSE) {
1591 c_write("Authenticated using RSA key \"",
1593 c_write(commentp, commentlen);
1594 c_write("\" from agent\r\n", 14);
1598 logevent("Pageant's response not accepted");
1600 logevent("Pageant failed to answer challenge");
1604 logevent("No reply received from Pageant");
1607 freebn(key.exponent);
1608 freebn(key.modulus);
1617 if (*cfg.keyfile && !tried_publickey)
1618 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1620 if (pktin.type == SSH1_SMSG_FAILURE &&
1622 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1623 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1624 logevent("Requested TIS authentication");
1625 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1627 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1628 logevent("TIS authentication declined");
1629 if (flags & FLAG_INTERACTIVE)
1630 c_write("TIS authentication refused.\r\n", 29);
1632 int challengelen = ((pktin.body[0] << 24) |
1633 (pktin.body[1] << 16) |
1634 (pktin.body[2] << 8) |
1636 logevent("Received TIS challenge");
1637 if (challengelen > sizeof(prompt)-1)
1638 challengelen = sizeof(prompt)-1; /* prevent overrun */
1639 memcpy(prompt, pktin.body+4, challengelen);
1640 prompt[challengelen] = '\0';
1643 if (pktin.type == SSH1_SMSG_FAILURE &&
1645 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1646 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1647 logevent("Requested CryptoCard authentication");
1648 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1650 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1651 logevent("CryptoCard authentication declined");
1652 c_write("CryptoCard authentication refused.\r\n", 29);
1654 int challengelen = ((pktin.body[0] << 24) |
1655 (pktin.body[1] << 16) |
1656 (pktin.body[2] << 8) |
1658 logevent("Received CryptoCard challenge");
1659 if (challengelen > sizeof(prompt)-1)
1660 challengelen = sizeof(prompt)-1; /* prevent overrun */
1661 memcpy(prompt, pktin.body+4, challengelen);
1662 strncpy(prompt + challengelen, "\r\nResponse : ",
1663 sizeof(prompt)-challengelen);
1664 prompt[sizeof(prompt)-1] = '\0';
1667 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1668 sprintf(prompt, "%.90s@%.90s's password: ",
1669 username, savedhost);
1671 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1672 char *comment = NULL;
1673 if (flags & FLAG_VERBOSE)
1674 c_write("Trying public key authentication.\r\n", 35);
1675 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1676 if (flags & FLAG_VERBOSE)
1677 c_write("No passphrase required.\r\n", 25);
1680 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1684 if (ssh_get_password) {
1685 if (!ssh_get_password(prompt, password, sizeof(password))) {
1687 * get_password failed to get a password (for
1688 * example because one was supplied on the command
1689 * line which has already failed to work).
1692 logevent("No more passwords to try");
1693 ssh_state = SSH_STATE_CLOSED;
1697 c_write(prompt, strlen(prompt));
1701 crWaitUntil(!ispkt);
1702 while (inlen--) switch (c = *in++) {
1719 if (((c >= ' ' && c <= '~') ||
1720 ((unsigned char)c >= 160)) && pos < sizeof(password))
1721 password[pos++] = c;
1729 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1731 * Try public key authentication with the specified
1734 static struct RSAKey pubkey;
1735 static Bignum challenge, response;
1737 static unsigned char buffer[32];
1739 tried_publickey = 1;
1740 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
1742 c_write("Couldn't load public key from ", 30);
1743 c_write(cfg.keyfile, strlen(cfg.keyfile));
1744 c_write(".\r\n", 3);
1745 continue; /* go and try password */
1748 c_write("Wrong passphrase.\r\n", 19);
1749 tried_publickey = 0;
1750 continue; /* try again */
1754 * Send a public key attempt.
1756 send_packet(SSH1_CMSG_AUTH_RSA,
1757 PKT_BIGNUM, pubkey.modulus, PKT_END);
1760 if (pktin.type == SSH1_SMSG_FAILURE) {
1761 c_write("Server refused our public key.\r\n", 32);
1762 continue; /* go and try password */
1764 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1765 bombout(("Bizarre response to offer of public key"));
1768 ssh1_read_bignum(pktin.body, &challenge);
1769 response = rsadecrypt(challenge, &pubkey);
1770 freebn(pubkey.private_exponent); /* burn the evidence */
1772 for (i = 0; i < 32; i++) {
1773 buffer[i] = bignum_byte(response, 31-i);
1777 MD5Update(&md5c, buffer, 32);
1778 MD5Update(&md5c, session_id, 16);
1779 MD5Final(buffer, &md5c);
1781 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1782 PKT_DATA, buffer, 16, PKT_END);
1785 if (pktin.type == SSH1_SMSG_FAILURE) {
1786 if (flags & FLAG_VERBOSE)
1787 c_write("Failed to authenticate with our public key.\r\n",
1789 continue; /* go and try password */
1790 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1791 bombout(("Bizarre response to RSA authentication response"));
1795 break; /* we're through! */
1797 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1799 logevent("Sent password");
1800 memset(password, 0, strlen(password));
1802 if (pktin.type == SSH1_SMSG_FAILURE) {
1803 if (flags & FLAG_VERBOSE)
1804 c_write("Access denied\r\n", 15);
1805 logevent("Authentication refused");
1806 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1807 logevent("Received disconnect request");
1808 ssh_state = SSH_STATE_CLOSED;
1810 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1811 bombout(("Strange packet received, type %d", pktin.type));
1816 logevent("Authentication successful");
1821 void sshfwd_close(struct ssh_channel *c) {
1823 if (ssh_version == 1) {
1824 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1826 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1827 ssh2_pkt_adduint32(c->remoteid);
1831 if (c->type == CHAN_X11) {
1833 logevent("X11 connection terminated");
1838 void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
1839 if (ssh_version == 1) {
1840 send_packet(SSH1_MSG_CHANNEL_DATA,
1841 PKT_INT, c->remoteid,
1846 ssh2_add_channel_data(c, buf, len);
1851 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1856 while (!do_ssh1_login(in, inlen, ispkt)) {
1859 if (ssh_state == SSH_STATE_CLOSED)
1862 if (cfg.agentfwd && agent_exists()) {
1863 logevent("Requesting agent forwarding");
1864 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1865 do { crReturnV; } while (!ispkt);
1866 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1867 bombout(("Protocol confusion"));
1869 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1870 logevent("Agent forwarding refused");
1872 logevent("Agent forwarding enabled");
1873 ssh_agentfwd_enabled = TRUE;
1877 if (cfg.x11_forward) {
1878 char proto[20], data[64];
1879 logevent("Requesting X11 forwarding");
1880 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
1881 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
1882 PKT_STR, proto, PKT_STR, data,
1885 do { crReturnV; } while (!ispkt);
1886 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1887 bombout(("Protocol confusion"));
1889 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1890 logevent("X11 forwarding refused");
1892 logevent("X11 forwarding enabled");
1893 ssh_X11_fwd_enabled = TRUE;
1898 send_packet(SSH1_CMSG_REQUEST_PTY,
1899 PKT_STR, cfg.termtype,
1900 PKT_INT, rows, PKT_INT, cols,
1901 PKT_INT, 0, PKT_INT, 0,
1904 ssh_state = SSH_STATE_INTERMED;
1905 do { crReturnV; } while (!ispkt);
1906 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1907 bombout(("Protocol confusion"));
1909 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1910 c_write("Server refused to allocate pty\r\n", 32);
1911 ssh_editing = ssh_echoing = 1;
1913 logevent("Allocated pty");
1915 ssh_editing = ssh_echoing = 1;
1918 if (cfg.compression) {
1919 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1920 do { crReturnV; } while (!ispkt);
1921 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1922 bombout(("Protocol confusion"));
1924 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1925 c_write("Server refused to compress\r\n", 32);
1927 logevent("Started compression");
1928 ssh1_compressing = TRUE;
1929 zlib_compress_init();
1930 zlib_decompress_init();
1933 if (*cfg.remote_cmd)
1934 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1936 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1937 logevent("Started session");
1939 ssh_state = SSH_STATE_SESSION;
1943 ssh_special(TS_EOF);
1945 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
1947 ssh_channels = newtree234(ssh_channelcmp);
1951 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1952 pktin.type == SSH1_SMSG_STDERR_DATA) {
1953 long len = GET_32BIT(pktin.body);
1954 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1956 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1957 ssh_state = SSH_STATE_CLOSED;
1958 logevent("Received disconnect request");
1960 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
1961 /* Remote side is trying to open a channel to talk to our
1962 * X-Server. Give them back a local channel number. */
1964 struct ssh_channel *c, *d;
1967 logevent("Received X11 connect request");
1968 /* Refuse if X11 forwarding is disabled. */
1969 if (!ssh_X11_fwd_enabled) {
1970 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1971 PKT_INT, GET_32BIT(pktin.body),
1973 logevent("Rejected X11 connect request");
1975 c = smalloc(sizeof(struct ssh_channel));
1977 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
1978 logevent("opening X11 forward connection failed");
1980 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1981 PKT_INT, GET_32BIT(pktin.body),
1984 logevent("opening X11 forward connection succeeded");
1985 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
1987 break; /* found a free number */
1990 c->remoteid = GET_32BIT(pktin.body);
1993 c->type = CHAN_X11; /* identify channel type */
1994 add234(ssh_channels, c);
1995 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1996 PKT_INT, c->remoteid, PKT_INT, c->localid,
1998 logevent("Opened X11 forward channel");
2001 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2002 /* Remote side is trying to open a channel to talk to our
2003 * agent. Give them back a local channel number. */
2005 struct ssh_channel *c;
2008 /* Refuse if agent forwarding is disabled. */
2009 if (!ssh_agentfwd_enabled) {
2010 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2011 PKT_INT, GET_32BIT(pktin.body),
2015 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
2017 break; /* found a free number */
2020 c = smalloc(sizeof(struct ssh_channel));
2021 c->remoteid = GET_32BIT(pktin.body);
2024 c->type = CHAN_AGENT; /* identify channel type */
2025 c->u.a.lensofar = 0;
2026 add234(ssh_channels, c);
2027 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2028 PKT_INT, c->remoteid, PKT_INT, c->localid,
2031 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2032 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2033 /* Remote side closes a channel. */
2034 unsigned i = GET_32BIT(pktin.body);
2035 struct ssh_channel *c;
2036 c = find234(ssh_channels, &i, ssh_channelfind);
2039 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2040 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
2041 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2042 logevent("X11 connection closed");
2043 assert(c->u.x11.s != NULL);
2044 x11_close(c->u.x11.s);
2047 c->closes |= closetype;
2048 if (c->closes == 3) {
2049 del234(ssh_channels, c);
2053 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2054 /* Data sent down one of our channels. */
2055 int i = GET_32BIT(pktin.body);
2056 int len = GET_32BIT(pktin.body+4);
2057 unsigned char *p = pktin.body+8;
2058 struct ssh_channel *c;
2059 c = find234(ssh_channels, &i, ssh_channelfind);
2063 x11_send(c->u.x11.s, p, len);
2066 /* Data for an agent message. Buffer it. */
2068 if (c->u.a.lensofar < 4) {
2069 int l = min(4 - c->u.a.lensofar, len);
2070 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2071 p += l; len -= l; c->u.a.lensofar += l;
2073 if (c->u.a.lensofar == 4) {
2074 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
2075 c->u.a.message = smalloc(c->u.a.totallen);
2076 memcpy(c->u.a.message, c->u.a.msglen, 4);
2078 if (c->u.a.lensofar >= 4 && len > 0) {
2079 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2080 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2081 p += l; len -= l; c->u.a.lensofar += l;
2083 if (c->u.a.lensofar == c->u.a.totallen) {
2084 void *reply, *sentreply;
2086 agent_query(c->u.a.message, c->u.a.totallen,
2091 /* Fake SSH_AGENT_FAILURE. */
2092 sentreply = "\0\0\0\1\5";
2095 send_packet(SSH1_MSG_CHANNEL_DATA,
2096 PKT_INT, c->remoteid,
2098 PKT_DATA, sentreply, replylen,
2102 sfree(c->u.a.message);
2103 c->u.a.lensofar = 0;
2109 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2110 /* may be from EXEC_SHELL on some servers */
2111 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2112 /* may be from EXEC_SHELL on some servers
2113 * if no pty is available or in other odd cases. Ignore */
2114 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2115 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2117 bombout(("Strange packet received: type %d", pktin.type));
2122 int len = min(inlen, 512);
2123 send_packet(SSH1_CMSG_STDIN_DATA,
2124 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2135 * Utility routine for decoding comma-separated strings in KEXINIT.
2137 static int in_commasep_string(char *needle, char *haystack, int haylen) {
2138 int needlen = strlen(needle);
2141 * Is it at the start of the string?
2143 if (haylen >= needlen && /* haystack is long enough */
2144 !memcmp(needle, haystack, needlen) && /* initial match */
2145 (haylen == needlen || haystack[needlen] == ',')
2146 /* either , or EOS follows */
2150 * If not, search for the next comma and resume after that.
2151 * If no comma found, terminate.
2153 while (haylen > 0 && *haystack != ',')
2154 haylen--, haystack++;
2157 haylen--, haystack++; /* skip over comma itself */
2162 * SSH2 key creation method.
2164 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
2166 /* First 20 bytes. */
2169 SHA_Bytes(&s, H, 20);
2170 SHA_Bytes(&s, &chr, 1);
2171 SHA_Bytes(&s, sessid, 20);
2172 SHA_Final(&s, keyspace);
2173 /* Next 20 bytes. */
2176 SHA_Bytes(&s, H, 20);
2177 SHA_Bytes(&s, keyspace, 20);
2178 SHA_Final(&s, keyspace+20);
2182 * Handle the SSH2 transport layer.
2184 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2186 static int i, j, len, nbits;
2188 static Bignum p, g, e, f, K;
2189 static int kex_init_value, kex_reply_value;
2190 static const struct ssh_mac **maclist;
2192 static const struct ssh2_cipher *cscipher_tobe = NULL;
2193 static const struct ssh2_cipher *sccipher_tobe = NULL;
2194 static const struct ssh_mac *csmac_tobe = NULL;
2195 static const struct ssh_mac *scmac_tobe = NULL;
2196 static const struct ssh_compress *cscomp_tobe = NULL;
2197 static const struct ssh_compress *sccomp_tobe = NULL;
2198 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2199 static int hostkeylen, siglen;
2200 static void *hkey; /* actual host key */
2201 static unsigned char exchange_hash[20];
2202 static unsigned char first_exchange_hash[20];
2203 static unsigned char keyspace[40];
2204 static const struct ssh2_ciphers *preferred_cipher;
2205 static const struct ssh_compress *preferred_comp;
2206 static int first_kex;
2213 * Set up the preferred cipher and compression.
2215 if (cfg.cipher == CIPHER_BLOWFISH) {
2216 preferred_cipher = &ssh2_blowfish;
2217 } else if (cfg.cipher == CIPHER_DES) {
2218 logevent("Single DES not supported in SSH2; using 3DES");
2219 preferred_cipher = &ssh2_3des;
2220 } else if (cfg.cipher == CIPHER_3DES) {
2221 preferred_cipher = &ssh2_3des;
2222 } else if (cfg.cipher == CIPHER_AES) {
2223 preferred_cipher = &ssh2_aes;
2225 /* Shouldn't happen, but we do want to initialise to _something_. */
2226 preferred_cipher = &ssh2_3des;
2228 if (cfg.compression)
2229 preferred_comp = &ssh_zlib;
2231 preferred_comp = &ssh_comp_none;
2234 * Be prepared to work around the buggy MAC problem.
2237 maclist = buggymacs, nmacs = lenof(buggymacs);
2239 maclist = macs, nmacs = lenof(macs);
2243 * Construct and send our key exchange packet.
2245 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2246 for (i = 0; i < 16; i++)
2247 ssh2_pkt_addbyte((unsigned char)random_byte());
2248 /* List key exchange algorithms. */
2249 ssh2_pkt_addstring_start();
2250 for (i = 0; i < lenof(kex_algs); i++) {
2251 ssh2_pkt_addstring_str(kex_algs[i]->name);
2252 if (i < lenof(kex_algs)-1)
2253 ssh2_pkt_addstring_str(",");
2255 /* List server host key algorithms. */
2256 ssh2_pkt_addstring_start();
2257 for (i = 0; i < lenof(hostkey_algs); i++) {
2258 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2259 if (i < lenof(hostkey_algs)-1)
2260 ssh2_pkt_addstring_str(",");
2262 /* List client->server encryption algorithms. */
2263 ssh2_pkt_addstring_start();
2264 for (i = 0; i < lenof(ciphers)+1; i++) {
2265 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2266 for (j = 0; j < c->nciphers; j++) {
2267 ssh2_pkt_addstring_str(c->list[j]->name);
2268 if (i < lenof(ciphers) || j < c->nciphers-1)
2269 ssh2_pkt_addstring_str(",");
2272 /* List server->client encryption algorithms. */
2273 ssh2_pkt_addstring_start();
2274 for (i = 0; i < lenof(ciphers)+1; i++) {
2275 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2276 for (j = 0; j < c->nciphers; j++) {
2277 ssh2_pkt_addstring_str(c->list[j]->name);
2278 if (i < lenof(ciphers) || j < c->nciphers-1)
2279 ssh2_pkt_addstring_str(",");
2282 /* List client->server MAC algorithms. */
2283 ssh2_pkt_addstring_start();
2284 for (i = 0; i < nmacs; i++) {
2285 ssh2_pkt_addstring_str(maclist[i]->name);
2287 ssh2_pkt_addstring_str(",");
2289 /* List server->client MAC algorithms. */
2290 ssh2_pkt_addstring_start();
2291 for (i = 0; i < nmacs; i++) {
2292 ssh2_pkt_addstring_str(maclist[i]->name);
2294 ssh2_pkt_addstring_str(",");
2296 /* List client->server compression algorithms. */
2297 ssh2_pkt_addstring_start();
2298 for (i = 0; i < lenof(compressions)+1; i++) {
2299 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2300 ssh2_pkt_addstring_str(c->name);
2301 if (i < lenof(compressions))
2302 ssh2_pkt_addstring_str(",");
2304 /* List server->client compression algorithms. */
2305 ssh2_pkt_addstring_start();
2306 for (i = 0; i < lenof(compressions)+1; i++) {
2307 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2308 ssh2_pkt_addstring_str(c->name);
2309 if (i < lenof(compressions))
2310 ssh2_pkt_addstring_str(",");
2312 /* List client->server languages. Empty list. */
2313 ssh2_pkt_addstring_start();
2314 /* List server->client languages. Empty list. */
2315 ssh2_pkt_addstring_start();
2316 /* First KEX packet does _not_ follow, because we're not that brave. */
2317 ssh2_pkt_addbool(FALSE);
2319 ssh2_pkt_adduint32(0);
2321 exhash = exhashbase;
2322 sha_string(&exhash, pktout.data+5, pktout.length-5);
2326 if (!ispkt) crWaitUntil(ispkt);
2327 sha_string(&exhash, pktin.data+5, pktin.length-5);
2330 * Now examine the other side's KEXINIT to see what we're up
2333 if (pktin.type != SSH2_MSG_KEXINIT) {
2334 bombout(("expected key exchange packet from server"));
2337 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2338 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2339 pktin.savedpos += 16; /* skip garbage cookie */
2340 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2341 for (i = 0; i < lenof(kex_algs); i++) {
2342 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2347 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2348 for (i = 0; i < lenof(hostkey_algs); i++) {
2349 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2350 hostkey = hostkey_algs[i];
2354 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2355 for (i = 0; i < lenof(ciphers)+1; i++) {
2356 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2357 for (j = 0; j < c->nciphers; j++) {
2358 if (in_commasep_string(c->list[j]->name, str, len)) {
2359 cscipher_tobe = c->list[j];
2366 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2367 for (i = 0; i < lenof(ciphers)+1; i++) {
2368 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2369 for (j = 0; j < c->nciphers; j++) {
2370 if (in_commasep_string(c->list[j]->name, str, len)) {
2371 sccipher_tobe = c->list[j];
2378 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2379 for (i = 0; i < nmacs; i++) {
2380 if (in_commasep_string(maclist[i]->name, str, len)) {
2381 csmac_tobe = maclist[i];
2385 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2386 for (i = 0; i < nmacs; i++) {
2387 if (in_commasep_string(maclist[i]->name, str, len)) {
2388 scmac_tobe = maclist[i];
2392 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2393 for (i = 0; i < lenof(compressions)+1; i++) {
2394 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2395 if (in_commasep_string(c->name, str, len)) {
2400 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2401 for (i = 0; i < lenof(compressions)+1; i++) {
2402 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2403 if (in_commasep_string(c->name, str, len)) {
2410 * If we're doing Diffie-Hellman group exchange, start by
2411 * requesting a group.
2413 if (kex == &ssh_diffiehellman_gex) {
2416 logevent("Doing Diffie-Hellman group exchange");
2418 * Work out number of bits. We start with the maximum key
2419 * length of either cipher...
2421 csbits = cscipher_tobe->keylen;
2422 scbits = sccipher_tobe->keylen;
2423 nbits = (csbits > scbits ? csbits : scbits);
2424 /* The keys only have 160-bit entropy, since they're based on
2425 * a SHA-1 hash. So cap the key size at 160 bits. */
2426 if (nbits > 160) nbits = 160;
2428 * ... and then work out how big a DH group we will need to
2429 * allow that much data.
2431 nbits = 512 << ((nbits-1) / 64);
2432 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2433 ssh2_pkt_adduint32(nbits);
2437 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2438 bombout(("expected key exchange group packet from server"));
2441 p = ssh2_pkt_getmp();
2442 g = ssh2_pkt_getmp();
2443 dh_setup_group(p, g);
2444 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2445 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2448 kex_init_value = SSH2_MSG_KEXDH_INIT;
2449 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
2452 logevent("Doing Diffie-Hellman key exchange");
2454 * Now generate and send e for Diffie-Hellman.
2457 ssh2_pkt_init(kex_init_value);
2462 if (pktin.type != kex_reply_value) {
2463 bombout(("expected key exchange reply packet from server"));
2466 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2467 f = ssh2_pkt_getmp();
2468 ssh2_pkt_getstring(&sigdata, &siglen);
2472 sha_string(&exhash, hostkeydata, hostkeylen);
2473 if (kex == &ssh_diffiehellman_gex) {
2474 sha_uint32(&exhash, nbits);
2475 sha_mpint(&exhash, p);
2476 sha_mpint(&exhash, g);
2478 sha_mpint(&exhash, e);
2479 sha_mpint(&exhash, f);
2480 sha_mpint(&exhash, K);
2481 SHA_Final(&exhash, exchange_hash);
2486 debug(("Exchange hash is:\r\n"));
2487 for (i = 0; i < 20; i++)
2488 debug((" %02x", exchange_hash[i]));
2492 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2493 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2494 bombout(("Server failed host key check"));
2499 * Expect SSH2_MSG_NEWKEYS from server.
2502 if (pktin.type != SSH2_MSG_NEWKEYS) {
2503 bombout(("expected new-keys packet from server"));
2508 * Authenticate remote host: verify host key. (We've already
2509 * checked the signature of the exchange hash.)
2511 keystr = hostkey->fmtkey(hkey);
2512 fingerprint = hostkey->fingerprint(hkey);
2513 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2514 keystr, fingerprint);
2515 if (first_kex) { /* don't bother logging this in rekeys */
2516 logevent("Host key fingerprint is:");
2517 logevent(fingerprint);
2521 hostkey->freekey(hkey);
2524 * Send SSH2_MSG_NEWKEYS.
2526 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2530 * Create and initialise session keys.
2532 cscipher = cscipher_tobe;
2533 sccipher = sccipher_tobe;
2536 cscomp = cscomp_tobe;
2537 sccomp = sccomp_tobe;
2538 cscomp->compress_init();
2539 sccomp->decompress_init();
2541 * Set IVs after keys. Here we use the exchange hash from the
2542 * _first_ key exchange.
2545 memcpy(first_exchange_hash, exchange_hash, sizeof(exchange_hash));
2546 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'C', keyspace);
2547 cscipher->setcskey(keyspace);
2548 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'D', keyspace);
2549 sccipher->setsckey(keyspace);
2550 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'A', keyspace);
2551 cscipher->setcsiv(keyspace);
2552 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'B', keyspace);
2553 sccipher->setsciv(keyspace);
2554 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'E', keyspace);
2555 csmac->setcskey(keyspace);
2556 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'F', keyspace);
2557 scmac->setsckey(keyspace);
2560 * If this is the first key exchange phase, we must pass the
2561 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2562 * wants to see it but because it will need time to initialise
2563 * itself before it sees an actual packet. In subsequent key
2564 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2565 * it would only confuse the layer above.
2573 * Now we're encrypting. Begin returning 1 to the protocol main
2574 * function so that other things can run on top of the
2575 * transport. If we ever see a KEXINIT, we must go back to the
2578 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
2581 logevent("Server initiated key re-exchange");
2582 goto begin_key_exchange;
2588 * Add data to an SSH2 channel output buffer.
2590 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2591 if (c->v2.outbufsize <
2592 c->v2.outbuflen + len) {
2594 c->v2.outbuflen + len + 1024;
2595 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2598 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2600 c->v2.outbuflen += len;
2604 * Attempt to send data on an SSH2 channel.
2606 static void ssh2_try_send(struct ssh_channel *c) {
2607 while (c->v2.remwindow > 0 &&
2608 c->v2.outbuflen > 0) {
2609 unsigned len = c->v2.remwindow;
2610 if (len > c->v2.outbuflen)
2611 len = c->v2.outbuflen;
2612 if (len > c->v2.remmaxpkt)
2613 len = c->v2.remmaxpkt;
2614 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2615 ssh2_pkt_adduint32(c->remoteid);
2616 ssh2_pkt_addstring_start();
2617 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2619 c->v2.outbuflen -= len;
2620 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2622 c->v2.remwindow -= len;
2627 * Handle the SSH2 userauth and connection layers.
2629 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2631 static unsigned long remote_winsize;
2632 static unsigned long remote_maxpkt;
2637 * Request userauth protocol, and await a response to it.
2639 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2640 ssh2_pkt_addstring("ssh-userauth");
2642 crWaitUntilV(ispkt);
2643 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2644 bombout(("Server refused user authentication protocol"));
2649 * FIXME: currently we support only password authentication.
2650 * (This places us technically in violation of the SSH2 spec.
2651 * We must fix this.)
2655 * Get a username and a password.
2657 static char username[100];
2658 static char password[100];
2662 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2663 c_write("login as: ", 10);
2666 crWaitUntilV(!ispkt);
2667 while (inlen--) switch (c = *in++) {
2674 c_write("\b \b", 3);
2680 c_write("\b \b", 3);
2689 if (((c >= ' ' && c <= '~') ||
2690 ((unsigned char)c >= 160)) && pos < 40) {
2691 username[pos++] = c;
2698 username[strcspn(username, "\n\r")] = '\0';
2701 strncpy(username, cfg.username, 99);
2702 username[99] = '\0';
2703 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2704 sprintf(stuff, "Using username \"%s\".\r\n", username);
2705 c_write(stuff, strlen(stuff));
2709 if (ssh_get_password) {
2711 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
2712 if (!ssh_get_password(prompt, password, sizeof(password))) {
2714 * get_password failed to get a password (for
2715 * example because one was supplied on the command
2716 * line which has already failed to work).
2719 logevent("No more passwords to try");
2720 ssh_state = SSH_STATE_CLOSED;
2724 c_write("password: ", 10);
2729 crWaitUntilV(!ispkt);
2730 while (inlen--) switch (c = *in++) {
2747 if (((c >= ' ' && c <= '~') ||
2748 ((unsigned char)c >= 160)) && pos < 40)
2749 password[pos++] = c;
2757 * We send the password packet lumped tightly together with
2758 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
2759 * string long enough to make the total length of the two
2760 * packets constant. This should ensure that a passive
2761 * listener doing traffic analyis can't work out the length
2764 * For this to work, we need an assumption about the
2765 * maximum length of the password packet. I think 256 is
2766 * pretty conservative. Anyone using a password longer than
2767 * that probably doesn't have much to worry about from
2768 * people who find out how long their password is!
2770 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2771 ssh2_pkt_addstring(username);
2772 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2773 ssh2_pkt_addstring("password");
2774 ssh2_pkt_addbool(FALSE);
2775 ssh2_pkt_addstring(password);
2778 * We'll include a string that's an exact multiple of the
2779 * cipher block size. If the cipher is NULL for some
2780 * reason, we don't do this trick at all because we gain
2785 ssh2_pkt_init(SSH2_MSG_IGNORE);
2786 ssh2_pkt_addstring_start();
2787 for (i = deferred_len; i <= 256; i += cscipher->blksize) {
2788 for (j = 0; j < cscipher->blksize; j++) {
2789 char c = (char)random_byte();
2790 ssh2_pkt_addstring_data(&c, 1);
2795 ssh2_pkt_defersend();
2797 crWaitUntilV(ispkt);
2798 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2799 c_write("Access denied\r\n", 15);
2800 logevent("Authentication refused");
2806 * Now we're authenticated for the connection protocol. The
2807 * connection protocol will automatically have started at this
2808 * point; there's no need to send SERVICE_REQUEST.
2812 * So now create a channel with a session in it.
2814 mainchan = smalloc(sizeof(struct ssh_channel));
2815 mainchan->localid = 100; /* as good as any */
2816 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2817 ssh2_pkt_addstring("session");
2818 ssh2_pkt_adduint32(mainchan->localid);
2819 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2820 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2822 crWaitUntilV(ispkt);
2823 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
2824 bombout(("Server refused to open a session"));
2826 /* FIXME: error data comes back in FAILURE packet */
2828 if (ssh2_pkt_getuint32() != mainchan->localid) {
2829 bombout(("Server's channel confirmation cited wrong channel"));
2832 mainchan->remoteid = ssh2_pkt_getuint32();
2833 mainchan->type = CHAN_MAINSESSION;
2834 mainchan->closes = 0;
2835 mainchan->v2.remwindow = ssh2_pkt_getuint32();
2836 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
2837 mainchan->v2.outbuffer = NULL;
2838 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
2839 ssh_channels = newtree234(ssh_channelcmp);
2840 add234(ssh_channels, mainchan);
2841 logevent("Opened channel for session");
2844 * Potentially enable X11 forwarding.
2846 if (cfg.x11_forward) {
2847 char proto[20], data[64];
2848 logevent("Requesting X11 forwarding");
2849 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2850 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2851 ssh2_pkt_adduint32(mainchan->remoteid);
2852 ssh2_pkt_addstring("x11-req");
2853 ssh2_pkt_addbool(1); /* want reply */
2854 ssh2_pkt_addbool(0); /* many connections */
2855 ssh2_pkt_addstring(proto);
2856 ssh2_pkt_addstring(data);
2857 ssh2_pkt_adduint32(0); /* screen number */
2861 crWaitUntilV(ispkt);
2862 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2863 unsigned i = ssh2_pkt_getuint32();
2864 struct ssh_channel *c;
2865 c = find234(ssh_channels, &i, ssh_channelfind);
2867 continue; /* nonexistent channel */
2868 c->v2.remwindow += ssh2_pkt_getuint32();
2870 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2872 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2873 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2874 bombout(("Server got confused by X11 forwarding request"));
2877 logevent("X11 forwarding refused");
2879 logevent("X11 forwarding enabled");
2880 ssh_X11_fwd_enabled = TRUE;
2885 * Now allocate a pty for the session.
2888 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2889 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2890 ssh2_pkt_addstring("pty-req");
2891 ssh2_pkt_addbool(1); /* want reply */
2892 ssh2_pkt_addstring(cfg.termtype);
2893 ssh2_pkt_adduint32(cols);
2894 ssh2_pkt_adduint32(rows);
2895 ssh2_pkt_adduint32(0); /* pixel width */
2896 ssh2_pkt_adduint32(0); /* pixel height */
2897 ssh2_pkt_addstring_start();
2898 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2900 ssh_state = SSH_STATE_INTERMED;
2903 crWaitUntilV(ispkt);
2904 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2905 unsigned i = ssh2_pkt_getuint32();
2906 struct ssh_channel *c;
2907 c = find234(ssh_channels, &i, ssh_channelfind);
2909 continue; /* nonexistent channel */
2910 c->v2.remwindow += ssh2_pkt_getuint32();
2912 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2914 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2915 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2916 bombout(("Server got confused by pty request"));
2919 c_write("Server refused to allocate pty\r\n", 32);
2920 ssh_editing = ssh_echoing = 1;
2922 logevent("Allocated pty");
2925 ssh_editing = ssh_echoing = 1;
2929 * Start a shell or a remote command.
2931 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2932 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2933 if (cfg.ssh_subsys) {
2934 ssh2_pkt_addstring("subsystem");
2935 ssh2_pkt_addbool(1); /* want reply */
2936 ssh2_pkt_addstring(cfg.remote_cmd);
2937 } else if (*cfg.remote_cmd) {
2938 ssh2_pkt_addstring("exec");
2939 ssh2_pkt_addbool(1); /* want reply */
2940 ssh2_pkt_addstring(cfg.remote_cmd);
2942 ssh2_pkt_addstring("shell");
2943 ssh2_pkt_addbool(1); /* want reply */
2947 crWaitUntilV(ispkt);
2948 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2949 unsigned i = ssh2_pkt_getuint32();
2950 struct ssh_channel *c;
2951 c = find234(ssh_channels, &i, ssh_channelfind);
2953 continue; /* nonexistent channel */
2954 c->v2.remwindow += ssh2_pkt_getuint32();
2956 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2957 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2958 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2959 bombout(("Server got confused by shell/command request"));
2962 bombout(("Server refused to start a shell/command"));
2965 logevent("Started a shell/command");
2968 ssh_state = SSH_STATE_SESSION;
2972 ssh_special(TS_EOF);
2977 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2980 static int try_send;
2984 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2985 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2988 unsigned i = ssh2_pkt_getuint32();
2989 struct ssh_channel *c;
2990 c = find234(ssh_channels, &i, ssh_channelfind);
2992 continue; /* nonexistent channel */
2993 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2994 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2995 continue; /* extended but not stderr */
2996 ssh2_pkt_getstring(&data, &length);
2999 case CHAN_MAINSESSION:
3000 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
3004 x11_send(c->u.x11.s, data, length);
3008 * Enlarge the window again at the remote
3009 * side, just in case it ever runs down and
3010 * they fail to send us any more data.
3012 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3013 ssh2_pkt_adduint32(c->remoteid);
3014 ssh2_pkt_adduint32(length);
3017 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
3018 ssh_state = SSH_STATE_CLOSED;
3019 logevent("Received disconnect message");
3021 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
3022 continue; /* exit status et al; ignore (FIXME?) */
3023 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
3024 unsigned i = ssh2_pkt_getuint32();
3025 struct ssh_channel *c;
3027 c = find234(ssh_channels, &i, ssh_channelfind);
3029 continue; /* nonexistent channel */
3031 if (c->type == CHAN_X11) {
3033 * Remote EOF on an X11 channel means we should
3034 * wrap up and close the channel ourselves.
3036 x11_close(c->u.x11.s);
3039 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
3040 unsigned i = ssh2_pkt_getuint32();
3041 struct ssh_channel *c;
3044 c = find234(ssh_channels, &i, ssh_channelfind);
3046 continue; /* nonexistent channel */
3047 if (c->closes == 0) {
3048 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3049 ssh2_pkt_adduint32(c->remoteid);
3052 /* Do pre-close processing on the channel. */
3054 case CHAN_MAINSESSION:
3055 break; /* nothing to see here, move along */
3059 del234(ssh_channels, c);
3060 sfree(c->v2.outbuffer);
3064 * See if that was the last channel left open.
3066 c = first234(ssh_channels, &e);
3068 logevent("All channels closed. Disconnecting");
3069 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3070 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3071 ssh2_pkt_addstring("All open channels closed");
3072 ssh2_pkt_addstring("en"); /* language tag */
3074 ssh_state = SSH_STATE_CLOSED;
3077 continue; /* remote sends close; ignore (FIXME) */
3078 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3079 unsigned i = ssh2_pkt_getuint32();
3080 struct ssh_channel *c;
3081 c = find234(ssh_channels, &i, ssh_channelfind);
3083 continue; /* nonexistent channel */
3084 mainchan->v2.remwindow += ssh2_pkt_getuint32();
3086 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3090 struct ssh_channel *c;
3091 ssh2_pkt_getstring(&type, &typelen);
3092 c = smalloc(sizeof(struct ssh_channel));
3094 if (typelen == 3 && !memcmp(type, "x11", 3)) {
3095 if (!ssh_X11_fwd_enabled)
3096 error = "X11 forwarding is not enabled";
3097 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
3098 error = "Unable to open an X11 connection";
3103 error = "Unsupported channel type requested";
3106 c->remoteid = ssh2_pkt_getuint32();
3108 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3109 ssh2_pkt_adduint32(c->remoteid);
3110 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3111 ssh2_pkt_addstring(error);
3112 ssh2_pkt_addstring("en"); /* language tag */
3116 struct ssh_channel *d;
3120 for (i=1, d = first234(ssh_channels, &e); d;
3123 break; /* found a free number */
3128 c->v2.remwindow = ssh2_pkt_getuint32();
3129 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3130 c->v2.outbuffer = NULL;
3131 c->v2.outbuflen = c->v2.outbufsize = 0;
3132 add234(ssh_channels, c);
3133 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3134 ssh2_pkt_adduint32(c->remoteid);
3135 ssh2_pkt_adduint32(c->localid);
3136 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3137 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3141 bombout(("Strange packet received: type %d", pktin.type));
3146 * We have spare data. Add it to the channel buffer.
3148 ssh2_add_channel_data(mainchan, in, inlen);
3153 struct ssh_channel *c;
3155 * Try to send data on all channels if we can.
3157 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3166 * Handle the top-level SSH2 protocol.
3168 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3170 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3172 do_ssh2_authconn(in, inlen, ispkt);
3176 * Called to set up the connection.
3178 * Returns an error message, or NULL on success.
3180 static char *ssh_init (char *host, int port, char **realhost) {
3184 if(crypto_startup() == 0)
3185 return "Microsoft high encryption pack not installed!";
3192 p = connect_to_host(host, port, realhost);
3200 * Called to send data down the Telnet connection.
3202 static void ssh_send (char *buf, int len) {
3203 if (s == NULL || ssh_protocol == NULL)
3206 ssh_protocol(buf, len, 0);
3210 * Called to set the size of the window from SSH's POV.
3212 static void ssh_size(void) {
3213 switch (ssh_state) {
3214 case SSH_STATE_BEFORE_SIZE:
3215 case SSH_STATE_PREPACKET:
3216 case SSH_STATE_CLOSED:
3217 break; /* do nothing */
3218 case SSH_STATE_INTERMED:
3219 size_needed = TRUE; /* buffer for later */
3221 case SSH_STATE_SESSION:
3223 if (ssh_version == 1) {
3224 send_packet(SSH1_CMSG_WINDOW_SIZE,
3225 PKT_INT, rows, PKT_INT, cols,
3226 PKT_INT, 0, PKT_INT, 0, PKT_END);
3228 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3229 ssh2_pkt_adduint32(mainchan->remoteid);
3230 ssh2_pkt_addstring("window-change");
3231 ssh2_pkt_addbool(0);
3232 ssh2_pkt_adduint32(cols);
3233 ssh2_pkt_adduint32(rows);
3234 ssh2_pkt_adduint32(0);
3235 ssh2_pkt_adduint32(0);
3244 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3245 * can send an EOF and collect resulting output (e.g. `plink
3248 static void ssh_special (Telnet_Special code) {
3249 if (code == TS_EOF) {
3250 if (ssh_state != SSH_STATE_SESSION) {
3252 * Buffer the EOF in case we are pre-SESSION, so we can
3253 * send it as soon as we reach SESSION.
3259 if (ssh_version == 1) {
3260 send_packet(SSH1_CMSG_EOF, PKT_END);
3262 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
3263 ssh2_pkt_adduint32(mainchan->remoteid);
3266 logevent("Sent EOF message");
3267 } else if (code == TS_PING) {
3268 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3270 if (ssh_version == 1) {
3271 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3273 ssh2_pkt_init(SSH2_MSG_IGNORE);
3274 ssh2_pkt_addstring_start();
3282 static Socket ssh_socket(void) { return s; }
3284 static int ssh_sendok(void) { return ssh_send_ok; }
3286 static int ssh_ldisc(int option) {
3287 if (option == LD_ECHO) return ssh_echoing;
3288 if (option == LD_EDIT) return ssh_editing;
3292 Backend ssh_backend = {