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 SSH2_MSG_DISCONNECT 1 /* 0x1 */
72 #define SSH2_MSG_IGNORE 2 /* 0x2 */
73 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
74 #define SSH2_MSG_DEBUG 4 /* 0x4 */
75 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
76 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
77 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
78 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
79 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
80 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
81 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
82 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
83 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
84 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
85 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
86 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
87 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
88 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
89 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
90 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
91 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
92 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
93 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
94 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
95 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
96 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
97 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
98 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
99 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
100 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
101 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
102 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
103 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
104 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
106 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
107 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
108 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
109 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
110 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
111 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
112 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
113 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
114 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
115 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
116 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
118 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
119 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
120 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
121 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
123 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
126 * Various remote-bug flags.
128 #define BUG_CHOKES_ON_SSH1_IGNORE 1
129 #define BUG_SSH2_HMAC 2
131 #define GET_32BIT(cp) \
132 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
133 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
134 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
135 ((unsigned long)(unsigned char)(cp)[3]))
137 #define PUT_32BIT(cp, value) { \
138 (cp)[0] = (unsigned char)((value) >> 24); \
139 (cp)[1] = (unsigned char)((value) >> 16); \
140 (cp)[2] = (unsigned char)((value) >> 8); \
141 (cp)[3] = (unsigned char)(value); }
143 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
145 /* Coroutine mechanics for the sillier bits of the code */
146 #define crBegin1 static int crLine = 0;
147 #define crBegin2 switch(crLine) { case 0:;
148 #define crBegin crBegin1; crBegin2;
149 #define crFinish(z) } crLine = 0; return (z)
150 #define crFinishV } crLine = 0; return
151 #define crReturn(z) \
153 crLine=__LINE__; return (z); case __LINE__:;\
157 crLine=__LINE__; return; case __LINE__:;\
159 #define crStop(z) do{ crLine = 0; return (z); }while(0)
160 #define crStopV do{ crLine = 0; return; }while(0)
161 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
162 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
164 extern char *x11_init (Socket *, char *, void *);
165 extern void x11_close (Socket);
166 extern void x11_send (Socket , char *, int);
167 extern void x11_invent_auth(char *, int, char *, int);
170 * Ciphers for SSH2. We miss out single-DES because it isn't
171 * supported; also 3DES and Blowfish are both done differently from
172 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
173 * endianness and different-sized keys.)
175 const static struct ssh2_ciphers *ciphers[] = {
181 const static struct ssh_kex *kex_algs[] = {
182 &ssh_diffiehellman_gex,
183 &ssh_diffiehellman };
185 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
187 static void nullmac_key(unsigned char *key) { }
188 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
189 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
190 const static struct ssh_mac ssh_mac_none = {
191 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
193 const static struct ssh_mac *macs[] = {
194 &ssh_sha1, &ssh_md5, &ssh_mac_none };
195 const static struct ssh_mac *buggymacs[] = {
196 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
198 static void ssh_comp_none_init(void) { }
199 static int ssh_comp_none_block(unsigned char *block, int len,
200 unsigned char **outblock, int *outlen) {
203 static int ssh_comp_none_disable(void) { return 0; }
204 const static struct ssh_compress ssh_comp_none = {
206 ssh_comp_none_init, ssh_comp_none_block,
207 ssh_comp_none_init, ssh_comp_none_block,
208 ssh_comp_none_disable
210 extern const struct ssh_compress ssh_zlib;
211 const static struct ssh_compress *compressions[] = {
212 &ssh_zlib, &ssh_comp_none };
214 enum { /* channel types */
221 * 2-3-4 tree storing channels.
224 unsigned remoteid, localid;
227 struct ssh2_data_channel {
228 unsigned char *outbuffer;
229 unsigned outbuflen, outbufsize;
230 unsigned remwindow, remmaxpkt;
233 struct ssh_agent_channel {
234 unsigned char *message;
235 unsigned char msglen[4];
236 int lensofar, totallen;
238 struct ssh_x11_channel {
253 static SHA_State exhash, exhashbase;
255 static Socket s = NULL;
257 static unsigned char session_key[32];
258 static int ssh1_compressing;
259 static int ssh_agentfwd_enabled;
260 static int ssh_X11_fwd_enabled;
261 static int ssh_remote_bugs;
262 static const struct ssh_cipher *cipher = NULL;
263 static const struct ssh2_cipher *cscipher = NULL;
264 static const struct ssh2_cipher *sccipher = NULL;
265 static const struct ssh_mac *csmac = NULL;
266 static const struct ssh_mac *scmac = NULL;
267 static const struct ssh_compress *cscomp = NULL;
268 static const struct ssh_compress *sccomp = NULL;
269 static const struct ssh_kex *kex = NULL;
270 static const struct ssh_signkey *hostkey = NULL;
271 static unsigned char ssh2_session_id[20];
272 int (*ssh_get_line)(const char *prompt, char *str, int maxlen,
275 static char *savedhost;
276 static int savedport;
277 static int ssh_send_ok;
278 static int ssh_echoing, ssh_editing;
280 static tree234 *ssh_channels; /* indexed by local id */
281 static struct ssh_channel *mainchan; /* primary session channel */
285 SSH_STATE_BEFORE_SIZE,
289 } ssh_state = SSH_STATE_PREPACKET;
291 static int size_needed = FALSE, eof_needed = FALSE;
293 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
294 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
295 static unsigned char *deferred_send_data = NULL;
296 static int deferred_len = 0, deferred_size = 0;
298 static int ssh_version;
299 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
300 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
301 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
302 static void ssh_size(void);
303 static void ssh_special (Telnet_Special);
304 static void ssh2_try_send(struct ssh_channel *c);
305 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
307 static int (*s_rdpkt)(unsigned char **data, int *datalen);
309 static struct rdpkt1_state_tag {
310 long len, pad, biglen, to_read;
311 unsigned long realcrc, gotcrc;
317 static struct rdpkt2_state_tag {
318 long len, pad, payload, packetlen, maclen;
321 unsigned long incoming_sequence;
324 static int ssh_channelcmp(void *av, void *bv) {
325 struct ssh_channel *a = (struct ssh_channel *)av;
326 struct ssh_channel *b = (struct ssh_channel *)bv;
327 if (a->localid < b->localid) return -1;
328 if (a->localid > b->localid) return +1;
331 static int ssh_channelfind(void *av, void *bv) {
332 unsigned *a = (unsigned *)av;
333 struct ssh_channel *b = (struct ssh_channel *)bv;
334 if (*a < b->localid) return -1;
335 if (*a > b->localid) return +1;
339 static void c_write (char *buf, int len) {
340 if ((flags & FLAG_STDERR)) {
342 for (i = 0; i < len; i++)
344 fputc(buf[i], stderr);
347 from_backend(1, buf, len);
350 static void c_write_str (char *buf) {
351 c_write(buf, strlen(buf));
355 * Collect incoming data in the incoming packet buffer.
356 * Decipher and verify the packet when it is completely read.
357 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
358 * Update the *data and *datalen variables.
359 * Return the additional nr of bytes needed, or 0 when
360 * a complete packet is available.
362 static int ssh1_rdpkt(unsigned char **data, int *datalen)
364 struct rdpkt1_state_tag *st = &rdpkt1_state;
373 for (st->i = st->len = 0; st->i < 4; st->i++) {
374 while ((*datalen) == 0)
376 st->len = (st->len << 8) + **data;
377 (*data)++, (*datalen)--;
381 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
382 st->len = 0x300; /* big enough to carry to end */
386 st->pad = 8 - (st->len % 8);
387 st->biglen = st->len + st->pad;
388 pktin.length = st->len - 5;
390 if (pktin.maxlen < st->biglen) {
391 pktin.maxlen = st->biglen;
392 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
393 srealloc(pktin.data, st->biglen+APIEXTRA));
395 fatalbox("Out of memory");
398 st->to_read = st->biglen;
400 while (st->to_read > 0) {
401 st->chunk = st->to_read;
402 while ((*datalen) == 0)
403 crReturn(st->to_read);
404 if (st->chunk > (*datalen))
405 st->chunk = (*datalen);
406 memcpy(st->p, *data, st->chunk);
408 *datalen -= st->chunk;
410 st->to_read -= st->chunk;
414 cipher->decrypt(pktin.data, st->biglen);
416 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
417 for (st->i = 0; st->i < st->biglen; st->i++)
418 debug((" %02x", (unsigned char)pktin.data[st->i]));
422 st->realcrc = crc32(pktin.data, st->biglen-4);
423 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
424 if (st->gotcrc != st->realcrc) {
425 bombout(("Incorrect CRC received on packet"));
429 pktin.body = pktin.data + st->pad + 1;
431 if (ssh1_compressing) {
432 unsigned char *decompblk;
436 debug(("Packet payload pre-decompression:\n"));
437 for (i = -1; i < pktin.length; i++)
438 debug((" %02x", (unsigned char)pktin.body[i]));
441 zlib_decompress_block(pktin.body-1, pktin.length+1,
442 &decompblk, &decomplen);
444 if (pktin.maxlen < st->pad + decomplen) {
445 pktin.maxlen = st->pad + decomplen;
446 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
447 pktin.body = pktin.data + st->pad + 1;
449 fatalbox("Out of memory");
452 memcpy(pktin.body-1, decompblk, decomplen);
454 pktin.length = decomplen-1;
456 debug(("Packet payload post-decompression:\n"));
457 for (i = -1; i < pktin.length; i++)
458 debug((" %02x", (unsigned char)pktin.body[i]));
463 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
464 pktin.type == SSH1_SMSG_STDERR_DATA ||
465 pktin.type == SSH1_MSG_DEBUG ||
466 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
467 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
468 long strlen = GET_32BIT(pktin.body);
469 if (strlen + 4 != pktin.length) {
470 bombout(("Received data packet with bogus string length"));
475 pktin.type = pktin.body[-1];
477 if (pktin.type == SSH1_MSG_DEBUG) {
478 /* log debug message */
480 int strlen = GET_32BIT(pktin.body);
481 strcpy(buf, "Remote: ");
482 if (strlen > 70) strlen = 70;
483 memcpy(buf+8, pktin.body+4, strlen);
484 buf[8+strlen] = '\0';
487 } else if (pktin.type == SSH1_MSG_IGNORE) {
495 static int ssh2_rdpkt(unsigned char **data, int *datalen)
497 struct rdpkt2_state_tag *st = &rdpkt2_state;
505 st->cipherblk = sccipher->blksize;
508 if (st->cipherblk < 8)
511 if (pktin.maxlen < st->cipherblk) {
512 pktin.maxlen = st->cipherblk;
513 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
514 srealloc(pktin.data, st->cipherblk+APIEXTRA));
516 fatalbox("Out of memory");
520 * Acquire and decrypt the first block of the packet. This will
521 * contain the length and padding details.
523 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
524 while ((*datalen) == 0)
525 crReturn(st->cipherblk-st->i);
526 pktin.data[st->i] = *(*data)++;
530 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
535 sccipher->decrypt(pktin.data, st->cipherblk);
538 * Now get the length and padding figures.
540 st->len = GET_32BIT(pktin.data);
541 st->pad = pktin.data[4];
544 * This enables us to deduce the payload length.
546 st->payload = st->len - st->pad - 1;
548 pktin.length = st->payload + 5;
551 * So now we can work out the total packet length.
553 st->packetlen = st->len + 4;
554 st->maclen = scmac ? scmac->len : 0;
557 * Adjust memory allocation if packet is too big.
559 if (pktin.maxlen < st->packetlen+st->maclen) {
560 pktin.maxlen = st->packetlen+st->maclen;
561 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
562 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
564 fatalbox("Out of memory");
568 * Read and decrypt the remainder of the packet.
570 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
571 while ((*datalen) == 0)
572 crReturn(st->packetlen + st->maclen - st->i);
573 pktin.data[st->i] = *(*data)++;
576 /* Decrypt everything _except_ the MAC. */
578 sccipher->decrypt(pktin.data + st->cipherblk,
579 st->packetlen - st->cipherblk);
582 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
583 for (st->i = 0; st->i < st->packetlen; st->i++)
584 debug((" %02x", (unsigned char)pktin.data[st->i]));
591 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
592 bombout(("Incorrect MAC received on packet"));
595 st->incoming_sequence++; /* whether or not we MACed */
598 * Decompress packet payload.
601 unsigned char *newpayload;
603 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
604 &newpayload, &newlen)) {
605 if (pktin.maxlen < newlen+5) {
606 pktin.maxlen = newlen+5;
607 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
608 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
610 fatalbox("Out of memory");
612 pktin.length = 5 + newlen;
613 memcpy(pktin.data+5, newpayload, newlen);
615 debug(("Post-decompression payload:\r\n"));
616 for (st->i = 0; st->i < newlen; st->i++)
617 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
626 pktin.type = pktin.data[5];
628 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
629 goto next_packet; /* FIXME: print DEBUG message */
634 static void ssh1_pktout_size(int len) {
637 len += 5; /* type and CRC */
641 pktout.length = len-5;
642 if (pktout.maxlen < biglen) {
643 pktout.maxlen = biglen;
645 /* Allocate enough buffer space for extra block
646 * for MS CryptEncrypt() */
647 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
648 srealloc(pktout.data, biglen+12));
650 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
651 srealloc(pktout.data, biglen+4));
654 fatalbox("Out of memory");
656 pktout.body = pktout.data+4+pad+1;
659 static void s_wrpkt_start(int type, int len) {
660 ssh1_pktout_size(len);
664 static int s_wrpkt_prepare(void) {
665 int pad, len, biglen, i;
668 pktout.body[-1] = pktout.type;
671 debug(("Packet payload pre-compression:\n"));
672 for (i = -1; i < pktout.length; i++)
673 debug((" %02x", (unsigned char)pktout.body[i]));
677 if (ssh1_compressing) {
678 unsigned char *compblk;
680 zlib_compress_block(pktout.body-1, pktout.length+1,
682 ssh1_pktout_size(complen-1);
683 memcpy(pktout.body-1, compblk, complen);
686 debug(("Packet payload post-compression:\n"));
687 for (i = -1; i < pktout.length; i++)
688 debug((" %02x", (unsigned char)pktout.body[i]));
693 len = pktout.length + 5; /* type and CRC */
697 for (i=0; i<pad; i++)
698 pktout.data[i+4] = random_byte();
699 crc = crc32(pktout.data+4, biglen-4);
700 PUT_32BIT(pktout.data+biglen, crc);
701 PUT_32BIT(pktout.data, len);
704 debug(("Sending packet len=%d\r\n", biglen+4));
705 for (i = 0; i < biglen+4; i++)
706 debug((" %02x", (unsigned char)pktout.data[i]));
710 cipher->encrypt(pktout.data+4, biglen);
715 static void s_wrpkt(void) {
717 len = s_wrpkt_prepare();
718 sk_write(s, pktout.data, len);
721 static void s_wrpkt_defer(void) {
723 len = s_wrpkt_prepare();
724 if (deferred_len + len > deferred_size) {
725 deferred_size = deferred_len + len + 128;
726 deferred_send_data = srealloc(deferred_send_data, deferred_size);
728 memcpy(deferred_send_data+deferred_len, pktout.data, len);
733 * Construct a packet with the specified contents.
735 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
737 unsigned char *p, *argp, argchar;
738 unsigned long argint;
739 int pktlen, argtype, arglen;
743 while ((argtype = va_arg(ap1, int)) != PKT_END) {
746 (void) va_arg(ap1, int);
750 (void) va_arg(ap1, char);
754 (void) va_arg(ap1, unsigned char *);
755 arglen = va_arg(ap1, int);
759 argp = va_arg(ap1, unsigned char *);
760 arglen = strlen(argp);
761 pktlen += 4 + arglen;
764 bn = va_arg(ap1, Bignum);
765 pktlen += ssh1_bignum_length(bn);
772 s_wrpkt_start(pkttype, pktlen);
775 while ((argtype = va_arg(ap2, int)) != PKT_END) {
778 argint = va_arg(ap2, int);
779 PUT_32BIT(p, argint);
783 argchar = va_arg(ap2, unsigned char);
788 argp = va_arg(ap2, unsigned char *);
789 arglen = va_arg(ap2, int);
790 memcpy(p, argp, arglen);
794 argp = va_arg(ap2, unsigned char *);
795 arglen = strlen(argp);
796 PUT_32BIT(p, arglen);
797 memcpy(p + 4, argp, arglen);
801 bn = va_arg(ap2, Bignum);
802 p += ssh1_write_bignum(p, bn);
808 static void send_packet(int pkttype, ...) {
810 va_start(ap1, pkttype);
811 va_start(ap2, pkttype);
812 construct_packet(pkttype, ap1, ap2);
816 static void defer_packet(int pkttype, ...) {
818 va_start(ap1, pkttype);
819 va_start(ap2, pkttype);
820 construct_packet(pkttype, ap1, ap2);
824 static int ssh_versioncmp(char *a, char *b) {
826 unsigned long av, bv;
828 av = strtoul(a, &ae, 10);
829 bv = strtoul(b, &be, 10);
830 if (av != bv) return (av < bv ? -1 : +1);
831 if (*ae == '.') ae++;
832 if (*be == '.') be++;
833 av = strtoul(ae, &ae, 10);
834 bv = strtoul(be, &be, 10);
835 if (av != bv) return (av < bv ? -1 : +1);
841 * Utility routines for putting an SSH-protocol `string' and
842 * `uint32' into a SHA state.
845 static void sha_string(SHA_State *s, void *str, int len) {
846 unsigned char lenblk[4];
847 PUT_32BIT(lenblk, len);
848 SHA_Bytes(s, lenblk, 4);
849 SHA_Bytes(s, str, len);
852 static void sha_uint32(SHA_State *s, unsigned i) {
853 unsigned char intblk[4];
854 PUT_32BIT(intblk, i);
855 SHA_Bytes(s, intblk, 4);
859 * SSH2 packet construction functions.
861 static void ssh2_pkt_ensure(int length) {
862 if (pktout.maxlen < length) {
863 pktout.maxlen = length + 256;
864 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
865 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
867 fatalbox("Out of memory");
870 static void ssh2_pkt_adddata(void *data, int len) {
871 pktout.length += len;
872 ssh2_pkt_ensure(pktout.length);
873 memcpy(pktout.data+pktout.length-len, data, len);
875 static void ssh2_pkt_addbyte(unsigned char byte) {
876 ssh2_pkt_adddata(&byte, 1);
878 static void ssh2_pkt_init(int pkt_type) {
880 ssh2_pkt_addbyte((unsigned char)pkt_type);
882 static void ssh2_pkt_addbool(unsigned char value) {
883 ssh2_pkt_adddata(&value, 1);
885 static void ssh2_pkt_adduint32(unsigned long value) {
888 ssh2_pkt_adddata(x, 4);
890 static void ssh2_pkt_addstring_start(void) {
891 ssh2_pkt_adduint32(0);
892 pktout.savedpos = pktout.length;
894 static void ssh2_pkt_addstring_str(char *data) {
895 ssh2_pkt_adddata(data, strlen(data));
896 PUT_32BIT(pktout.data + pktout.savedpos - 4,
897 pktout.length - pktout.savedpos);
899 static void ssh2_pkt_addstring_data(char *data, int len) {
900 ssh2_pkt_adddata(data, len);
901 PUT_32BIT(pktout.data + pktout.savedpos - 4,
902 pktout.length - pktout.savedpos);
904 static void ssh2_pkt_addstring(char *data) {
905 ssh2_pkt_addstring_start();
906 ssh2_pkt_addstring_str(data);
908 static char *ssh2_mpint_fmt(Bignum b, int *len) {
910 int i, n = (ssh1_bignum_bitcount(b)+7)/8;
913 fatalbox("out of memory");
915 for (i = 1; i <= n; i++)
916 p[i] = bignum_byte(b, n-i);
918 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
920 memmove(p, p+i, n+1-i);
924 static void ssh2_pkt_addmp(Bignum b) {
927 p = ssh2_mpint_fmt(b, &len);
928 ssh2_pkt_addstring_start();
929 ssh2_pkt_addstring_data(p, len);
934 * Construct an SSH2 final-form packet: compress it, encrypt it,
935 * put the MAC on it. Final packet, ready to be sent, is stored in
936 * pktout.data. Total length is returned.
938 static int ssh2_pkt_construct(void) {
939 int cipherblk, maclen, padding, i;
940 static unsigned long outgoing_sequence = 0;
943 * Compress packet payload.
946 debug(("Pre-compression payload:\r\n"));
947 for (i = 5; i < pktout.length; i++)
948 debug((" %02x", (unsigned char)pktout.data[i]));
952 unsigned char *newpayload;
954 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
955 &newpayload, &newlen)) {
957 ssh2_pkt_adddata(newpayload, newlen);
963 * Add padding. At least four bytes, and must also bring total
964 * length (minus MAC) up to a multiple of the block size.
966 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
967 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
969 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
970 maclen = csmac ? csmac->len : 0;
971 ssh2_pkt_ensure(pktout.length + padding + maclen);
972 pktout.data[4] = padding;
973 for (i = 0; i < padding; i++)
974 pktout.data[pktout.length + i] = random_byte();
975 PUT_32BIT(pktout.data, pktout.length + padding - 4);
977 csmac->generate(pktout.data, pktout.length + padding,
979 outgoing_sequence++; /* whether or not we MACed */
982 debug(("Sending packet len=%d\r\n", pktout.length+padding));
983 for (i = 0; i < pktout.length+padding; i++)
984 debug((" %02x", (unsigned char)pktout.data[i]));
989 cscipher->encrypt(pktout.data, pktout.length + padding);
991 /* Ready-to-send packet starts at pktout.data. We return length. */
992 return pktout.length + padding + maclen;
996 * Construct and send an SSH2 packet immediately.
998 static void ssh2_pkt_send(void) {
999 int len = ssh2_pkt_construct();
1000 sk_write(s, pktout.data, len);
1004 * Construct an SSH2 packet and add it to a deferred data block.
1005 * Useful for sending multiple packets in a single sk_write() call,
1006 * to prevent a traffic-analysing listener from being able to work
1007 * out the length of any particular packet (such as the password
1010 * Note that because SSH2 sequence-numbers its packets, this can
1011 * NOT be used as an m4-style `defer' allowing packets to be
1012 * constructed in one order and sent in another.
1014 static void ssh2_pkt_defer(void) {
1015 int len = ssh2_pkt_construct();
1016 if (deferred_len + len > deferred_size) {
1017 deferred_size = deferred_len + len + 128;
1018 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1020 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1021 deferred_len += len;
1025 * Send the whole deferred data block constructed by
1026 * ssh2_pkt_defer() or SSH1's defer_packet().
1028 static void ssh_pkt_defersend(void) {
1029 sk_write(s, deferred_send_data, deferred_len);
1030 deferred_len = deferred_size = 0;
1031 sfree(deferred_send_data);
1032 deferred_send_data = NULL;
1036 void bndebug(char *string, Bignum b) {
1039 p = ssh2_mpint_fmt(b, &len);
1040 debug(("%s", string));
1041 for (i = 0; i < len; i++)
1042 debug((" %02x", p[i]));
1048 static void sha_mpint(SHA_State *s, Bignum b) {
1051 p = ssh2_mpint_fmt(b, &len);
1052 sha_string(s, p, len);
1057 * SSH2 packet decode functions.
1059 static unsigned long ssh2_pkt_getuint32(void) {
1060 unsigned long value;
1061 if (pktin.length - pktin.savedpos < 4)
1062 return 0; /* arrgh, no way to decline (FIXME?) */
1063 value = GET_32BIT(pktin.data+pktin.savedpos);
1064 pktin.savedpos += 4;
1067 static int ssh2_pkt_getbool(void) {
1068 unsigned long value;
1069 if (pktin.length - pktin.savedpos < 1)
1070 return 0; /* arrgh, no way to decline (FIXME?) */
1071 value = pktin.data[pktin.savedpos] != 0;
1075 static void ssh2_pkt_getstring(char **p, int *length) {
1077 if (pktin.length - pktin.savedpos < 4)
1079 *length = GET_32BIT(pktin.data+pktin.savedpos);
1080 pktin.savedpos += 4;
1081 if (pktin.length - pktin.savedpos < *length)
1083 *p = pktin.data+pktin.savedpos;
1084 pktin.savedpos += *length;
1086 static Bignum ssh2_pkt_getmp(void) {
1091 ssh2_pkt_getstring(&p, &length);
1095 bombout(("internal error: Can't handle negative mpints"));
1098 b = bignum_from_bytes(p, length);
1103 * Examine the remote side's version string and compare it against
1104 * a list of known buggy implementations.
1106 static void ssh_detect_bugs(char *vstring) {
1107 char *imp; /* pointer to implementation part */
1109 imp += strcspn(imp, "-");
1110 imp += strcspn(imp, "-");
1112 ssh_remote_bugs = 0;
1114 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1115 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1116 !strcmp(imp, "1.2.22")) {
1118 * These versions don't support SSH1_MSG_IGNORE, so we have
1119 * to use a different defence against password length
1122 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1123 logevent("We believe remote version has SSH1 ignore bug");
1126 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1127 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1128 !strncmp(imp, "2.1 ", 4)) {
1130 * These versions have the HMAC bug.
1132 ssh_remote_bugs |= BUG_SSH2_HMAC;
1133 logevent("We believe remote version has SSH2 HMAC bug");
1137 static int do_ssh_init(unsigned char c) {
1139 static char version[10];
1140 static char vstring[80];
1141 static char vlog[sizeof(vstring)+20];
1146 /* Search for the string "SSH-" in the input. */
1149 static const int transS[] = { 1, 2, 2, 1 };
1150 static const int transH[] = { 0, 0, 3, 0 };
1151 static const int transminus[] = { 0, 0, 0, -1 };
1152 if (c == 'S') i = transS[i];
1153 else if (c == 'H') i = transH[i];
1154 else if (c == '-') i = transminus[i];
1158 crReturn(1); /* get another character */
1161 strcpy(vstring, "SSH-");
1165 crReturn(1); /* get another char */
1166 if (vsp < vstring+sizeof(vstring)-1)
1172 } else if (i < sizeof(version)-1)
1179 ssh_agentfwd_enabled = FALSE;
1180 rdpkt2_state.incoming_sequence = 0;
1183 sprintf(vlog, "Server version: %s", vstring);
1184 ssh_detect_bugs(vstring);
1185 vlog[strcspn(vlog, "\r\n")] = '\0';
1189 * Server version "1.99" means we can choose whether we use v1
1190 * or v2 protocol. Choice is based on cfg.sshprot.
1192 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1194 * This is a v2 server. Begin v2 protocol.
1196 char *verstring = "SSH-2.0-PuTTY";
1197 SHA_Init(&exhashbase);
1199 * Hash our version string and their version string.
1201 sha_string(&exhashbase, verstring, strlen(verstring));
1202 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1203 sprintf(vstring, "%s\n", verstring);
1204 sprintf(vlog, "We claim version: %s", verstring);
1206 logevent("Using SSH protocol version 2");
1207 sk_write(s, vstring, strlen(vstring));
1208 ssh_protocol = ssh2_protocol;
1210 s_rdpkt = ssh2_rdpkt;
1213 * This is a v1 server. Begin v1 protocol.
1215 sprintf(vstring, "SSH-%s-PuTTY\n",
1216 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1217 sprintf(vlog, "We claim version: %s", vstring);
1218 vlog[strcspn(vlog, "\r\n")] = '\0';
1220 logevent("Using SSH protocol version 1");
1221 sk_write(s, vstring, strlen(vstring));
1222 ssh_protocol = ssh1_protocol;
1224 s_rdpkt = ssh1_rdpkt;
1226 ssh_state = SSH_STATE_BEFORE_SIZE;
1231 static void ssh_gotdata(unsigned char *data, int datalen)
1236 * To begin with, feed the characters one by one to the
1237 * protocol initialisation / selection function do_ssh_init().
1238 * When that returns 0, we're done with the initial greeting
1239 * exchange and can move on to packet discipline.
1244 crReturnV; /* more data please */
1245 ret = do_ssh_init(*data);
1252 * We emerge from that loop when the initial negotiation is
1253 * over and we have selected an s_rdpkt function. Now pass
1254 * everything to s_rdpkt, and then pass the resulting packets
1255 * to the proper protocol handler.
1260 while (datalen > 0) {
1261 if ( s_rdpkt(&data, &datalen) == 0 ) {
1262 ssh_protocol(NULL, 0, 1);
1263 if (ssh_state == SSH_STATE_CLOSED) {
1273 static int ssh_closing (Plug plug, char *error_msg, int error_code, int calling_back) {
1274 ssh_state = SSH_STATE_CLOSED;
1278 /* A socket error has occurred. */
1279 connection_fatal (error_msg);
1281 /* Otherwise, the remote side closed the connection normally. */
1286 static int ssh_receive(Plug plug, int urgent, char *data, int len) {
1287 ssh_gotdata (data, len);
1288 if (ssh_state == SSH_STATE_CLOSED) {
1299 * Connect to specified host and port.
1300 * Returns an error message, or NULL on success.
1301 * Also places the canonical host name into `realhost'.
1303 static char *connect_to_host(char *host, int port, char **realhost)
1305 static struct plug_function_table fn_table = {
1308 }, *fn_table_ptr = &fn_table;
1317 savedhost = smalloc(1+strlen(host));
1319 fatalbox("Out of memory");
1320 strcpy(savedhost, host);
1323 port = 22; /* default ssh port */
1336 addr = sk_namelookup(host, realhost);
1337 if ( (err = sk_addr_error(addr)) )
1347 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1348 if ( (err = sk_socket_error(s)) )
1352 sk_write(s, "connect ", 8);
1353 sk_write(s, FWhost, strlen(FWhost));
1356 sprintf(buf, " %d\n", FWport);
1357 sk_write(s, buf, strlen(buf));
1365 * Handle the key exchange and user authentication phases.
1367 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1370 unsigned char *rsabuf, *keystr1, *keystr2;
1371 unsigned char cookie[8];
1372 struct RSAKey servkey, hostkey;
1373 struct MD5Context md5c;
1374 static unsigned long supported_ciphers_mask, supported_auths_mask;
1375 static int tried_publickey;
1376 static unsigned char session_id[16];
1378 static char username[100];
1382 if (!ispkt) crWaitUntil(ispkt);
1384 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1385 bombout(("Public key packet not received"));
1389 logevent("Received public keys");
1391 memcpy(cookie, pktin.body, 8);
1393 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1394 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1397 * Log the host key fingerprint.
1401 logevent("Host key fingerprint is:");
1402 strcpy(logmsg, " ");
1403 hostkey.comment = NULL;
1404 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1409 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1410 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1413 MD5Update(&md5c, keystr2, hostkey.bytes);
1414 MD5Update(&md5c, keystr1, servkey.bytes);
1415 MD5Update(&md5c, pktin.body, 8);
1416 MD5Final(session_id, &md5c);
1418 for (i=0; i<32; i++)
1419 session_key[i] = random_byte();
1421 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1423 rsabuf = smalloc(len);
1425 fatalbox("Out of memory");
1428 * Verify the host key.
1432 * First format the key into a string.
1434 int len = rsastr_len(&hostkey);
1435 char fingerprint[100];
1436 char *keystr = smalloc(len);
1438 fatalbox("Out of memory");
1439 rsastr_fmt(keystr, &hostkey);
1440 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1441 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1445 for (i=0; i<32; i++) {
1446 rsabuf[i] = session_key[i];
1448 rsabuf[i] ^= session_id[i];
1451 if (hostkey.bytes > servkey.bytes) {
1452 rsaencrypt(rsabuf, 32, &servkey);
1453 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1455 rsaencrypt(rsabuf, 32, &hostkey);
1456 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1459 logevent("Encrypted session key");
1461 switch (cfg.cipher) {
1462 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break;
1463 case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break;
1464 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break;
1466 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1467 cipher_type = SSH_CIPHER_3DES;
1470 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1471 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
1472 cipher_type = SSH_CIPHER_3DES;
1474 switch (cipher_type) {
1475 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1476 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1477 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1480 send_packet(SSH1_CMSG_SESSION_KEY,
1481 PKT_CHAR, cipher_type,
1482 PKT_DATA, cookie, 8,
1483 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1484 PKT_DATA, rsabuf, len,
1488 logevent("Trying to enable encryption...");
1492 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1493 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1495 cipher->sesskey(session_key);
1499 if (pktin.type != SSH1_SMSG_SUCCESS) {
1500 bombout(("Encryption not successfully enabled"));
1504 logevent("Successfully started encryption");
1510 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1512 if (!ssh_get_line("login as: ",
1513 username, sizeof(username), FALSE)) {
1515 * get_line failed to get a username.
1518 logevent("No username provided. Abandoning session.");
1519 ssh_state = SSH_STATE_CLOSED;
1523 c_write_str("login as: ");
1526 crWaitUntil(!ispkt);
1527 while (inlen--) switch (c = *in++) {
1534 c_write_str("\b \b");
1540 c_write_str("\b \b");
1549 if (((c >= ' ' && c <= '~') ||
1550 ((unsigned char)c >= 160)) && pos < 40) {
1551 username[pos++] = c;
1557 c_write_str("\r\n");
1558 username[strcspn(username, "\n\r")] = '\0';
1561 strncpy(username, cfg.username, 99);
1562 username[99] = '\0';
1565 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1567 char userlog[22+sizeof(username)];
1568 sprintf(userlog, "Sent username \"%s\"", username);
1570 if (flags & FLAG_INTERACTIVE &&
1571 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1572 strcat(userlog, "\r\n");
1573 c_write_str(userlog);
1580 tried_publickey = 0;
1582 while (pktin.type == SSH1_SMSG_FAILURE) {
1583 static char password[100];
1584 static char prompt[200];
1587 static int pwpkt_type;
1589 * Show password prompt, having first obtained it via a TIS
1590 * or CryptoCard exchange if we're doing TIS or CryptoCard
1593 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1594 if (agent_exists()) {
1596 * Attempt RSA authentication using Pageant.
1598 static unsigned char request[5], *response, *p;
1599 static int responselen;
1600 static int i, nkeys;
1601 static int authed = FALSE;
1604 logevent("Pageant is running. Requesting keys.");
1606 /* Request the keys held by the agent. */
1607 PUT_32BIT(request, 1);
1608 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1609 agent_query(request, 5, &r, &responselen);
1610 response = (unsigned char *)r;
1613 nkeys = GET_32BIT(p); p += 4;
1614 { char buf[64]; sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1616 for (i = 0; i < nkeys; i++) {
1617 static struct RSAKey key;
1618 static Bignum challenge;
1619 static char *commentp;
1620 static int commentlen;
1622 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1625 p += ssh1_read_bignum(p, &key.exponent);
1626 p += ssh1_read_bignum(p, &key.modulus);
1627 commentlen = GET_32BIT(p); p += 4;
1628 commentp = p; p += commentlen;
1629 send_packet(SSH1_CMSG_AUTH_RSA,
1630 PKT_BIGNUM, key.modulus, PKT_END);
1632 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1633 logevent("Key refused");
1636 logevent("Received RSA challenge");
1637 ssh1_read_bignum(pktin.body, &challenge);
1639 char *agentreq, *q, *ret;
1641 len = 1 + 4; /* message type, bit count */
1642 len += ssh1_bignum_length(key.exponent);
1643 len += ssh1_bignum_length(key.modulus);
1644 len += ssh1_bignum_length(challenge);
1645 len += 16; /* session id */
1646 len += 4; /* response format */
1647 agentreq = smalloc(4 + len);
1648 PUT_32BIT(agentreq, len);
1650 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1651 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1653 q += ssh1_write_bignum(q, key.exponent);
1654 q += ssh1_write_bignum(q, key.modulus);
1655 q += ssh1_write_bignum(q, challenge);
1656 memcpy(q, session_id, 16); q += 16;
1657 PUT_32BIT(q, 1); /* response format */
1658 agent_query(agentreq, len+4, &ret, &retlen);
1661 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1662 logevent("Sending Pageant's response");
1663 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1664 PKT_DATA, ret+5, 16, PKT_END);
1667 if (pktin.type == SSH1_SMSG_SUCCESS) {
1668 logevent("Pageant's response accepted");
1669 if (flags & FLAG_VERBOSE) {
1670 c_write_str("Authenticated using RSA key \"");
1671 c_write(commentp, commentlen);
1672 c_write_str("\" from agent\r\n");
1676 logevent("Pageant's response not accepted");
1678 logevent("Pageant failed to answer challenge");
1682 logevent("No reply received from Pageant");
1685 freebn(key.exponent);
1686 freebn(key.modulus);
1695 if (*cfg.keyfile && !tried_publickey)
1696 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1698 if (pktin.type == SSH1_SMSG_FAILURE &&
1700 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1701 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1702 logevent("Requested TIS authentication");
1703 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1705 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1706 logevent("TIS authentication declined");
1707 if (flags & FLAG_INTERACTIVE)
1708 c_write_str("TIS authentication refused.\r\n");
1710 int challengelen = ((pktin.body[0] << 24) |
1711 (pktin.body[1] << 16) |
1712 (pktin.body[2] << 8) |
1714 logevent("Received TIS challenge");
1715 if (challengelen > sizeof(prompt)-1)
1716 challengelen = sizeof(prompt)-1; /* prevent overrun */
1717 memcpy(prompt, pktin.body+4, challengelen);
1718 prompt[challengelen] = '\0';
1721 if (pktin.type == SSH1_SMSG_FAILURE &&
1723 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1724 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1725 logevent("Requested CryptoCard authentication");
1726 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1728 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1729 logevent("CryptoCard authentication declined");
1730 c_write_str("CryptoCard authentication refused.\r\n");
1732 int challengelen = ((pktin.body[0] << 24) |
1733 (pktin.body[1] << 16) |
1734 (pktin.body[2] << 8) |
1736 logevent("Received CryptoCard challenge");
1737 if (challengelen > sizeof(prompt)-1)
1738 challengelen = sizeof(prompt)-1; /* prevent overrun */
1739 memcpy(prompt, pktin.body+4, challengelen);
1740 strncpy(prompt + challengelen, "\r\nResponse : ",
1741 sizeof(prompt)-challengelen);
1742 prompt[sizeof(prompt)-1] = '\0';
1745 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1746 sprintf(prompt, "%.90s@%.90s's password: ",
1747 username, savedhost);
1749 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1750 char *comment = NULL;
1751 if (flags & FLAG_VERBOSE)
1752 c_write_str("Trying public key authentication.\r\n");
1753 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1754 if (flags & FLAG_VERBOSE)
1755 c_write_str("No passphrase required.\r\n");
1758 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1763 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
1765 * get_line failed to get a password (for example
1766 * because one was supplied on the command line
1767 * which has already failed to work). Terminate.
1769 logevent("No more passwords to try");
1770 ssh_state = SSH_STATE_CLOSED;
1774 c_write_str(prompt);
1778 crWaitUntil(!ispkt);
1779 while (inlen--) switch (c = *in++) {
1796 if (((c >= ' ' && c <= '~') ||
1797 ((unsigned char)c >= 160)) && pos < sizeof(password))
1798 password[pos++] = c;
1802 c_write_str("\r\n");
1806 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1808 * Try public key authentication with the specified
1811 static struct RSAKey pubkey;
1812 static Bignum challenge, response;
1814 static unsigned char buffer[32];
1816 tried_publickey = 1;
1817 i = loadrsakey(cfg.keyfile, &pubkey, password);
1819 c_write_str("Couldn't load public key from ");
1820 c_write_str(cfg.keyfile);
1821 c_write_str(".\r\n");
1822 continue; /* go and try password */
1825 c_write_str("Wrong passphrase.\r\n");
1826 tried_publickey = 0;
1827 continue; /* try again */
1831 * Send a public key attempt.
1833 send_packet(SSH1_CMSG_AUTH_RSA,
1834 PKT_BIGNUM, pubkey.modulus, PKT_END);
1837 if (pktin.type == SSH1_SMSG_FAILURE) {
1838 c_write_str("Server refused our public key.\r\n");
1839 continue; /* go and try password */
1841 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1842 bombout(("Bizarre response to offer of public key"));
1845 ssh1_read_bignum(pktin.body, &challenge);
1846 response = rsadecrypt(challenge, &pubkey);
1847 freebn(pubkey.private_exponent); /* burn the evidence */
1849 for (i = 0; i < 32; i++) {
1850 buffer[i] = bignum_byte(response, 31-i);
1854 MD5Update(&md5c, buffer, 32);
1855 MD5Update(&md5c, session_id, 16);
1856 MD5Final(buffer, &md5c);
1858 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1859 PKT_DATA, buffer, 16, PKT_END);
1862 if (pktin.type == SSH1_SMSG_FAILURE) {
1863 if (flags & FLAG_VERBOSE)
1864 c_write_str("Failed to authenticate with our public key.\r\n");
1865 continue; /* go and try password */
1866 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1867 bombout(("Bizarre response to RSA authentication response"));
1871 break; /* we're through! */
1873 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1875 * Defence against traffic analysis: we send a
1876 * whole bunch of packets containing strings of
1877 * different lengths. One of these strings is the
1878 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
1879 * The others are all random data in
1880 * SSH1_MSG_IGNORE packets. This way a passive
1881 * listener can't tell which is the password, and
1882 * hence can't deduce the password length.
1884 * Anybody with a password length greater than 16
1885 * bytes is going to have enough entropy in their
1886 * password that a listener won't find it _that_
1887 * much help to know how long it is. So what we'll
1890 * - if password length < 16, we send 15 packets
1891 * containing string lengths 1 through 15
1893 * - otherwise, we let N be the nearest multiple
1894 * of 8 below the password length, and send 8
1895 * packets containing string lengths N through
1896 * N+7. This won't obscure the order of
1897 * magnitude of the password length, but it will
1898 * introduce a bit of extra uncertainty.
1900 * A few servers (the old 1.2.18 through 1.2.22)
1901 * can't deal with SSH1_MSG_IGNORE. For these
1902 * servers, we need an alternative defence. We make
1903 * use of the fact that the password is interpreted
1904 * as a C string: so we can append a NUL, then some
1907 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
1912 len = strlen(password);
1913 if (len < sizeof(string)) {
1915 strcpy(string, password);
1916 len++; /* cover the zero byte */
1917 while (len < sizeof(string)) {
1918 string[len++] = (char)random_byte();
1923 send_packet(pwpkt_type, PKT_INT, len,
1924 PKT_DATA, s, len, PKT_END);
1926 int bottom, top, pwlen, i;
1929 pwlen = strlen(password);
1931 bottom = 0; /* zero length passwords are OK! :-) */
1934 bottom = pwlen &~ 7;
1938 assert(pwlen >= bottom && pwlen <= top);
1940 randomstr = smalloc(top+1);
1942 for (i = bottom; i <= top; i++) {
1944 defer_packet(pwpkt_type, PKT_STR, password, PKT_END);
1946 for (j = 0; j < i; j++) {
1948 randomstr[j] = random_byte();
1949 } while (randomstr[j] == '\0');
1951 randomstr[i] = '\0';
1952 defer_packet(SSH1_MSG_IGNORE,
1953 PKT_STR, randomstr, PKT_END);
1956 ssh_pkt_defersend();
1959 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1962 logevent("Sent password");
1963 memset(password, 0, strlen(password));
1965 if (pktin.type == SSH1_SMSG_FAILURE) {
1966 if (flags & FLAG_VERBOSE)
1967 c_write_str("Access denied\r\n");
1968 logevent("Authentication refused");
1969 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1970 logevent("Received disconnect request");
1971 ssh_state = SSH_STATE_CLOSED;
1973 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1974 bombout(("Strange packet received, type %d", pktin.type));
1979 logevent("Authentication successful");
1984 void sshfwd_close(struct ssh_channel *c) {
1986 if (ssh_version == 1) {
1987 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1989 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1990 ssh2_pkt_adduint32(c->remoteid);
1994 if (c->type == CHAN_X11) {
1996 logevent("X11 connection terminated");
2001 void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
2002 if (ssh_version == 1) {
2003 send_packet(SSH1_MSG_CHANNEL_DATA,
2004 PKT_INT, c->remoteid,
2009 ssh2_add_channel_data(c, buf, len);
2014 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
2019 while (!do_ssh1_login(in, inlen, ispkt)) {
2022 if (ssh_state == SSH_STATE_CLOSED)
2025 if (cfg.agentfwd && agent_exists()) {
2026 logevent("Requesting agent forwarding");
2027 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2028 do { crReturnV; } while (!ispkt);
2029 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2030 bombout(("Protocol confusion"));
2032 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2033 logevent("Agent forwarding refused");
2035 logevent("Agent forwarding enabled");
2036 ssh_agentfwd_enabled = TRUE;
2040 if (cfg.x11_forward) {
2041 char proto[20], data[64];
2042 logevent("Requesting X11 forwarding");
2043 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2044 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2045 PKT_STR, proto, PKT_STR, data,
2048 do { crReturnV; } while (!ispkt);
2049 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2050 bombout(("Protocol confusion"));
2052 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2053 logevent("X11 forwarding refused");
2055 logevent("X11 forwarding enabled");
2056 ssh_X11_fwd_enabled = TRUE;
2061 send_packet(SSH1_CMSG_REQUEST_PTY,
2062 PKT_STR, cfg.termtype,
2063 PKT_INT, rows, PKT_INT, cols,
2064 PKT_INT, 0, PKT_INT, 0,
2067 ssh_state = SSH_STATE_INTERMED;
2068 do { crReturnV; } while (!ispkt);
2069 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2070 bombout(("Protocol confusion"));
2072 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2073 c_write_str("Server refused to allocate pty\r\n");
2074 ssh_editing = ssh_echoing = 1;
2076 logevent("Allocated pty");
2078 ssh_editing = ssh_echoing = 1;
2081 if (cfg.compression) {
2082 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2083 do { crReturnV; } while (!ispkt);
2084 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2085 bombout(("Protocol confusion"));
2087 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2088 c_write_str("Server refused to compress\r\n");
2090 logevent("Started compression");
2091 ssh1_compressing = TRUE;
2092 zlib_compress_init();
2093 zlib_decompress_init();
2096 if (*cfg.remote_cmd)
2097 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
2099 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2100 logevent("Started session");
2102 ssh_state = SSH_STATE_SESSION;
2106 ssh_special(TS_EOF);
2108 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2110 ssh_channels = newtree234(ssh_channelcmp);
2114 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2115 pktin.type == SSH1_SMSG_STDERR_DATA) {
2116 long len = GET_32BIT(pktin.body);
2117 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2119 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2120 ssh_state = SSH_STATE_CLOSED;
2121 logevent("Received disconnect request");
2123 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2124 /* Remote side is trying to open a channel to talk to our
2125 * X-Server. Give them back a local channel number. */
2127 struct ssh_channel *c, *d;
2130 logevent("Received X11 connect request");
2131 /* Refuse if X11 forwarding is disabled. */
2132 if (!ssh_X11_fwd_enabled) {
2133 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2134 PKT_INT, GET_32BIT(pktin.body),
2136 logevent("Rejected X11 connect request");
2138 c = smalloc(sizeof(struct ssh_channel));
2140 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
2141 logevent("opening X11 forward connection failed");
2143 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2144 PKT_INT, GET_32BIT(pktin.body),
2147 logevent("opening X11 forward connection succeeded");
2148 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
2150 break; /* found a free number */
2153 c->remoteid = GET_32BIT(pktin.body);
2156 c->type = CHAN_X11; /* identify channel type */
2157 add234(ssh_channels, c);
2158 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2159 PKT_INT, c->remoteid, PKT_INT, c->localid,
2161 logevent("Opened X11 forward channel");
2164 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2165 /* Remote side is trying to open a channel to talk to our
2166 * agent. Give them back a local channel number. */
2168 struct ssh_channel *c;
2171 /* Refuse if agent forwarding is disabled. */
2172 if (!ssh_agentfwd_enabled) {
2173 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2174 PKT_INT, GET_32BIT(pktin.body),
2178 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
2180 break; /* found a free number */
2183 c = smalloc(sizeof(struct ssh_channel));
2184 c->remoteid = GET_32BIT(pktin.body);
2187 c->type = CHAN_AGENT; /* identify channel type */
2188 c->u.a.lensofar = 0;
2189 add234(ssh_channels, c);
2190 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2191 PKT_INT, c->remoteid, PKT_INT, c->localid,
2194 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2195 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2196 /* Remote side closes a channel. */
2197 unsigned i = GET_32BIT(pktin.body);
2198 struct ssh_channel *c;
2199 c = find234(ssh_channels, &i, ssh_channelfind);
2202 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2203 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
2204 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2205 logevent("X11 connection closed");
2206 assert(c->u.x11.s != NULL);
2207 x11_close(c->u.x11.s);
2210 c->closes |= closetype;
2211 if (c->closes == 3) {
2212 del234(ssh_channels, c);
2216 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2217 /* Data sent down one of our channels. */
2218 int i = GET_32BIT(pktin.body);
2219 int len = GET_32BIT(pktin.body+4);
2220 unsigned char *p = pktin.body+8;
2221 struct ssh_channel *c;
2222 c = find234(ssh_channels, &i, ssh_channelfind);
2226 x11_send(c->u.x11.s, p, len);
2229 /* Data for an agent message. Buffer it. */
2231 if (c->u.a.lensofar < 4) {
2232 int l = min(4 - c->u.a.lensofar, len);
2233 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2234 p += l; len -= l; c->u.a.lensofar += l;
2236 if (c->u.a.lensofar == 4) {
2237 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
2238 c->u.a.message = smalloc(c->u.a.totallen);
2239 memcpy(c->u.a.message, c->u.a.msglen, 4);
2241 if (c->u.a.lensofar >= 4 && len > 0) {
2242 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2243 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2244 p += l; len -= l; c->u.a.lensofar += l;
2246 if (c->u.a.lensofar == c->u.a.totallen) {
2247 void *reply, *sentreply;
2249 agent_query(c->u.a.message, c->u.a.totallen,
2254 /* Fake SSH_AGENT_FAILURE. */
2255 sentreply = "\0\0\0\1\5";
2258 send_packet(SSH1_MSG_CHANNEL_DATA,
2259 PKT_INT, c->remoteid,
2261 PKT_DATA, sentreply, replylen,
2265 sfree(c->u.a.message);
2266 c->u.a.lensofar = 0;
2272 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2273 /* may be from EXEC_SHELL on some servers */
2274 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2275 /* may be from EXEC_SHELL on some servers
2276 * if no pty is available or in other odd cases. Ignore */
2277 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2278 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2280 bombout(("Strange packet received: type %d", pktin.type));
2285 int len = min(inlen, 512);
2286 send_packet(SSH1_CMSG_STDIN_DATA,
2287 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2298 * Utility routine for decoding comma-separated strings in KEXINIT.
2300 static int in_commasep_string(char *needle, char *haystack, int haylen) {
2301 int needlen = strlen(needle);
2304 * Is it at the start of the string?
2306 if (haylen >= needlen && /* haystack is long enough */
2307 !memcmp(needle, haystack, needlen) && /* initial match */
2308 (haylen == needlen || haystack[needlen] == ',')
2309 /* either , or EOS follows */
2313 * If not, search for the next comma and resume after that.
2314 * If no comma found, terminate.
2316 while (haylen > 0 && *haystack != ',')
2317 haylen--, haystack++;
2320 haylen--, haystack++; /* skip over comma itself */
2325 * SSH2 key creation method.
2327 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
2329 /* First 20 bytes. */
2332 SHA_Bytes(&s, H, 20);
2333 SHA_Bytes(&s, &chr, 1);
2334 SHA_Bytes(&s, sessid, 20);
2335 SHA_Final(&s, keyspace);
2336 /* Next 20 bytes. */
2339 SHA_Bytes(&s, H, 20);
2340 SHA_Bytes(&s, keyspace, 20);
2341 SHA_Final(&s, keyspace+20);
2345 * Handle the SSH2 transport layer.
2347 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2349 static int i, j, len, nbits, pbits;
2351 static Bignum p, g, e, f, K;
2352 static int kex_init_value, kex_reply_value;
2353 static const struct ssh_mac **maclist;
2355 static const struct ssh2_cipher *cscipher_tobe = NULL;
2356 static const struct ssh2_cipher *sccipher_tobe = NULL;
2357 static const struct ssh_mac *csmac_tobe = NULL;
2358 static const struct ssh_mac *scmac_tobe = NULL;
2359 static const struct ssh_compress *cscomp_tobe = NULL;
2360 static const struct ssh_compress *sccomp_tobe = NULL;
2361 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2362 static int hostkeylen, siglen;
2363 static void *hkey; /* actual host key */
2364 static unsigned char exchange_hash[20];
2365 static unsigned char keyspace[40];
2366 static const struct ssh2_ciphers *preferred_cipher;
2367 static const struct ssh_compress *preferred_comp;
2368 static int first_kex;
2375 * Set up the preferred cipher and compression.
2377 if (cfg.cipher == CIPHER_BLOWFISH) {
2378 preferred_cipher = &ssh2_blowfish;
2379 } else if (cfg.cipher == CIPHER_DES) {
2380 logevent("Single DES not supported in SSH2; using 3DES");
2381 preferred_cipher = &ssh2_3des;
2382 } else if (cfg.cipher == CIPHER_3DES) {
2383 preferred_cipher = &ssh2_3des;
2384 } else if (cfg.cipher == CIPHER_AES) {
2385 preferred_cipher = &ssh2_aes;
2387 /* Shouldn't happen, but we do want to initialise to _something_. */
2388 preferred_cipher = &ssh2_3des;
2390 if (cfg.compression)
2391 preferred_comp = &ssh_zlib;
2393 preferred_comp = &ssh_comp_none;
2396 * Be prepared to work around the buggy MAC problem.
2398 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
2399 maclist = buggymacs, nmacs = lenof(buggymacs);
2401 maclist = macs, nmacs = lenof(macs);
2405 * Construct and send our key exchange packet.
2407 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2408 for (i = 0; i < 16; i++)
2409 ssh2_pkt_addbyte((unsigned char)random_byte());
2410 /* List key exchange algorithms. */
2411 ssh2_pkt_addstring_start();
2412 for (i = 0; i < lenof(kex_algs); i++) {
2413 ssh2_pkt_addstring_str(kex_algs[i]->name);
2414 if (i < lenof(kex_algs)-1)
2415 ssh2_pkt_addstring_str(",");
2417 /* List server host key algorithms. */
2418 ssh2_pkt_addstring_start();
2419 for (i = 0; i < lenof(hostkey_algs); i++) {
2420 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2421 if (i < lenof(hostkey_algs)-1)
2422 ssh2_pkt_addstring_str(",");
2424 /* List client->server encryption algorithms. */
2425 ssh2_pkt_addstring_start();
2426 for (i = 0; i < lenof(ciphers)+1; i++) {
2427 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2428 for (j = 0; j < c->nciphers; j++) {
2429 ssh2_pkt_addstring_str(c->list[j]->name);
2430 if (i < lenof(ciphers) || j < c->nciphers-1)
2431 ssh2_pkt_addstring_str(",");
2434 /* List server->client encryption algorithms. */
2435 ssh2_pkt_addstring_start();
2436 for (i = 0; i < lenof(ciphers)+1; i++) {
2437 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2438 for (j = 0; j < c->nciphers; j++) {
2439 ssh2_pkt_addstring_str(c->list[j]->name);
2440 if (i < lenof(ciphers) || j < c->nciphers-1)
2441 ssh2_pkt_addstring_str(",");
2444 /* List client->server MAC algorithms. */
2445 ssh2_pkt_addstring_start();
2446 for (i = 0; i < nmacs; i++) {
2447 ssh2_pkt_addstring_str(maclist[i]->name);
2449 ssh2_pkt_addstring_str(",");
2451 /* List server->client MAC algorithms. */
2452 ssh2_pkt_addstring_start();
2453 for (i = 0; i < nmacs; i++) {
2454 ssh2_pkt_addstring_str(maclist[i]->name);
2456 ssh2_pkt_addstring_str(",");
2458 /* List client->server compression algorithms. */
2459 ssh2_pkt_addstring_start();
2460 for (i = 0; i < lenof(compressions)+1; i++) {
2461 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2462 ssh2_pkt_addstring_str(c->name);
2463 if (i < lenof(compressions))
2464 ssh2_pkt_addstring_str(",");
2466 /* List server->client compression algorithms. */
2467 ssh2_pkt_addstring_start();
2468 for (i = 0; i < lenof(compressions)+1; i++) {
2469 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2470 ssh2_pkt_addstring_str(c->name);
2471 if (i < lenof(compressions))
2472 ssh2_pkt_addstring_str(",");
2474 /* List client->server languages. Empty list. */
2475 ssh2_pkt_addstring_start();
2476 /* List server->client languages. Empty list. */
2477 ssh2_pkt_addstring_start();
2478 /* First KEX packet does _not_ follow, because we're not that brave. */
2479 ssh2_pkt_addbool(FALSE);
2481 ssh2_pkt_adduint32(0);
2483 exhash = exhashbase;
2484 sha_string(&exhash, pktout.data+5, pktout.length-5);
2488 if (!ispkt) crWaitUntil(ispkt);
2489 sha_string(&exhash, pktin.data+5, pktin.length-5);
2492 * Now examine the other side's KEXINIT to see what we're up
2495 if (pktin.type != SSH2_MSG_KEXINIT) {
2496 bombout(("expected key exchange packet from server"));
2499 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2500 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2501 pktin.savedpos += 16; /* skip garbage cookie */
2502 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2503 for (i = 0; i < lenof(kex_algs); i++) {
2504 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2509 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2510 for (i = 0; i < lenof(hostkey_algs); i++) {
2511 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2512 hostkey = hostkey_algs[i];
2516 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2517 for (i = 0; i < lenof(ciphers)+1; i++) {
2518 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2519 for (j = 0; j < c->nciphers; j++) {
2520 if (in_commasep_string(c->list[j]->name, str, len)) {
2521 cscipher_tobe = c->list[j];
2528 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2529 for (i = 0; i < lenof(ciphers)+1; i++) {
2530 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2531 for (j = 0; j < c->nciphers; j++) {
2532 if (in_commasep_string(c->list[j]->name, str, len)) {
2533 sccipher_tobe = c->list[j];
2540 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2541 for (i = 0; i < nmacs; i++) {
2542 if (in_commasep_string(maclist[i]->name, str, len)) {
2543 csmac_tobe = maclist[i];
2547 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2548 for (i = 0; i < nmacs; i++) {
2549 if (in_commasep_string(maclist[i]->name, str, len)) {
2550 scmac_tobe = maclist[i];
2554 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2555 for (i = 0; i < lenof(compressions)+1; i++) {
2556 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2557 if (in_commasep_string(c->name, str, len)) {
2562 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2563 for (i = 0; i < lenof(compressions)+1; i++) {
2564 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2565 if (in_commasep_string(c->name, str, len)) {
2572 * Work out the number of bits of key we will need from the key
2573 * exchange. We start with the maximum key length of either
2579 csbits = cscipher_tobe->keylen;
2580 scbits = sccipher_tobe->keylen;
2581 nbits = (csbits > scbits ? csbits : scbits);
2583 /* The keys only have 160-bit entropy, since they're based on
2584 * a SHA-1 hash. So cap the key size at 160 bits. */
2585 if (nbits > 160) nbits = 160;
2588 * If we're doing Diffie-Hellman group exchange, start by
2589 * requesting a group.
2591 if (kex == &ssh_diffiehellman_gex) {
2592 logevent("Doing Diffie-Hellman group exchange");
2594 * Work out how big a DH group we will need to allow that
2597 pbits = 512 << ((nbits-1) / 64);
2598 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2599 ssh2_pkt_adduint32(pbits);
2603 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2604 bombout(("expected key exchange group packet from server"));
2607 p = ssh2_pkt_getmp();
2608 g = ssh2_pkt_getmp();
2609 dh_setup_group(p, g);
2610 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2611 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2614 kex_init_value = SSH2_MSG_KEXDH_INIT;
2615 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
2618 logevent("Doing Diffie-Hellman key exchange");
2620 * Now generate and send e for Diffie-Hellman.
2622 e = dh_create_e(nbits*2);
2623 ssh2_pkt_init(kex_init_value);
2628 if (pktin.type != kex_reply_value) {
2629 bombout(("expected key exchange reply packet from server"));
2632 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2633 f = ssh2_pkt_getmp();
2634 ssh2_pkt_getstring(&sigdata, &siglen);
2638 sha_string(&exhash, hostkeydata, hostkeylen);
2639 if (kex == &ssh_diffiehellman_gex) {
2640 sha_uint32(&exhash, pbits);
2641 sha_mpint(&exhash, p);
2642 sha_mpint(&exhash, g);
2644 sha_mpint(&exhash, e);
2645 sha_mpint(&exhash, f);
2646 sha_mpint(&exhash, K);
2647 SHA_Final(&exhash, exchange_hash);
2652 debug(("Exchange hash is:\r\n"));
2653 for (i = 0; i < 20; i++)
2654 debug((" %02x", exchange_hash[i]));
2658 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2659 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2660 bombout(("Server failed host key check"));
2665 * Expect SSH2_MSG_NEWKEYS from server.
2668 if (pktin.type != SSH2_MSG_NEWKEYS) {
2669 bombout(("expected new-keys packet from server"));
2674 * Authenticate remote host: verify host key. (We've already
2675 * checked the signature of the exchange hash.)
2677 keystr = hostkey->fmtkey(hkey);
2678 fingerprint = hostkey->fingerprint(hkey);
2679 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2680 keystr, fingerprint);
2681 if (first_kex) { /* don't bother logging this in rekeys */
2682 logevent("Host key fingerprint is:");
2683 logevent(fingerprint);
2687 hostkey->freekey(hkey);
2690 * Send SSH2_MSG_NEWKEYS.
2692 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2696 * Create and initialise session keys.
2698 cscipher = cscipher_tobe;
2699 sccipher = sccipher_tobe;
2702 cscomp = cscomp_tobe;
2703 sccomp = sccomp_tobe;
2704 cscomp->compress_init();
2705 sccomp->decompress_init();
2707 * Set IVs after keys. Here we use the exchange hash from the
2708 * _first_ key exchange.
2711 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
2712 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
2713 cscipher->setcskey(keyspace);
2714 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
2715 sccipher->setsckey(keyspace);
2716 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
2717 cscipher->setcsiv(keyspace);
2718 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
2719 sccipher->setsciv(keyspace);
2720 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
2721 csmac->setcskey(keyspace);
2722 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
2723 scmac->setsckey(keyspace);
2726 * If this is the first key exchange phase, we must pass the
2727 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2728 * wants to see it but because it will need time to initialise
2729 * itself before it sees an actual packet. In subsequent key
2730 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2731 * it would only confuse the layer above.
2739 * Now we're encrypting. Begin returning 1 to the protocol main
2740 * function so that other things can run on top of the
2741 * transport. If we ever see a KEXINIT, we must go back to the
2744 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
2747 logevent("Server initiated key re-exchange");
2748 goto begin_key_exchange;
2754 * Add data to an SSH2 channel output buffer.
2756 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2757 if (c->v2.outbufsize <
2758 c->v2.outbuflen + len) {
2760 c->v2.outbuflen + len + 1024;
2761 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2764 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2766 c->v2.outbuflen += len;
2770 * Attempt to send data on an SSH2 channel.
2772 static void ssh2_try_send(struct ssh_channel *c) {
2773 while (c->v2.remwindow > 0 &&
2774 c->v2.outbuflen > 0) {
2775 unsigned len = c->v2.remwindow;
2776 if (len > c->v2.outbuflen)
2777 len = c->v2.outbuflen;
2778 if (len > c->v2.remmaxpkt)
2779 len = c->v2.remmaxpkt;
2780 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2781 ssh2_pkt_adduint32(c->remoteid);
2782 ssh2_pkt_addstring_start();
2783 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2785 c->v2.outbuflen -= len;
2786 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2788 c->v2.remwindow -= len;
2793 * Handle the SSH2 userauth and connection layers.
2795 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2797 static unsigned long remote_winsize;
2798 static unsigned long remote_maxpkt;
2800 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD
2804 AUTH_TYPE_PUBLICKEY,
2805 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
2806 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
2809 static int gotit, need_pw, can_pubkey, can_passwd;
2810 static int tried_pubkey_config, tried_agent;
2811 static int we_are_in;
2812 static char username[100];
2813 static char pwprompt[200];
2814 static char password[100];
2819 * Request userauth protocol, and await a response to it.
2821 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2822 ssh2_pkt_addstring("ssh-userauth");
2824 crWaitUntilV(ispkt);
2825 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2826 bombout(("Server refused user authentication protocol"));
2831 * We repeat this whole loop, including the username prompt,
2832 * until we manage a successful authentication. If the user
2833 * types the wrong _password_, they are sent back to the
2834 * beginning to try another username. (If they specify a
2835 * username in the config, they are never asked, even if they
2836 * do give a wrong password.)
2838 * I think this best serves the needs of
2840 * - the people who have no configuration, no keys, and just
2841 * want to try repeated (username,password) pairs until they
2842 * type both correctly
2844 * - people who have keys and configuration but occasionally
2845 * need to fall back to passwords
2847 * - people with a key held in Pageant, who might not have
2848 * logged in to a particular machine before; so they want to
2849 * type a username, and then _either_ their key will be
2850 * accepted, _or_ they will type a password. If they mistype
2851 * the username they will want to be able to get back and
2862 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2864 if (!ssh_get_line("login as: ",
2865 username, sizeof(username), FALSE)) {
2867 * get_line failed to get a username.
2870 logevent("No username provided. Abandoning session.");
2871 ssh_state = SSH_STATE_CLOSED;
2875 c_write_str("login as: ");
2878 crWaitUntilV(!ispkt);
2879 while (inlen--) switch (c = *in++) {
2886 c_write_str("\b \b");
2892 c_write_str("\b \b");
2901 if (((c >= ' ' && c <= '~') ||
2902 ((unsigned char)c >= 160)) && pos < 40) {
2903 username[pos++] = c;
2910 c_write_str("\r\n");
2911 username[strcspn(username, "\n\r")] = '\0';
2914 strncpy(username, cfg.username, 99);
2915 username[99] = '\0';
2916 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2917 sprintf(stuff, "Using username \"%s\".\r\n", username);
2923 * Send an authentication request using method "none": (a)
2924 * just in case it succeeds, and (b) so that we know what
2925 * authentication methods we can usefully try next.
2927 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2928 ssh2_pkt_addstring(username);
2929 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2930 ssh2_pkt_addstring("none"); /* method */
2932 type = AUTH_TYPE_NONE;
2936 tried_pubkey_config = FALSE;
2937 tried_agent = FALSE;
2941 * Wait for the result of the last authentication request.
2944 crWaitUntilV(ispkt);
2945 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
2946 /* FIXME: should support this */
2947 crWaitUntilV(ispkt);
2949 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
2950 logevent("Access granted");
2955 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
2956 bombout(("Strange packet received during authentication: type %d",
2963 * OK, we're now sitting on a USERAUTH_FAILURE message, so
2964 * we can look at the string in it and know what we can
2965 * helpfully try next.
2970 ssh2_pkt_getstring(&methods, &methlen);
2971 if (!ssh2_pkt_getbool()) {
2973 * We have received an unequivocal Access
2974 * Denied. This can translate to a variety of
2977 * - if we'd just tried "none" authentication,
2978 * it's not worth printing anything at all
2980 * - if we'd just tried a public key _offer_,
2981 * the message should be "Server refused our
2982 * key" (or no message at all if the key
2983 * came from Pageant)
2985 * - if we'd just tried anything else, the
2986 * message really should be "Access denied".
2988 * Additionally, if we'd just tried password
2989 * authentication, we should break out of this
2990 * whole loop so as to go back to the username
2993 if (type == AUTH_TYPE_NONE) {
2995 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
2996 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
2997 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
2998 c_write_str("Server refused our key\r\n");
2999 logevent("Server refused public key");
3001 c_write_str("Access denied\r\n");
3002 logevent("Access denied");
3003 if (type == AUTH_TYPE_PASSWORD) {
3009 c_write_str("Further authentication required\r\n");
3010 logevent("Further authentication required");
3013 can_pubkey = in_commasep_string("publickey", methods, methlen);
3014 can_passwd = in_commasep_string("password", methods, methlen);
3019 if (!method && can_pubkey && agent_exists && !tried_agent) {
3021 * Attempt public-key authentication using Pageant.
3023 static unsigned char request[5], *response, *p;
3024 static int responselen;
3025 static int i, nkeys;
3026 static int authed = FALSE;
3031 logevent("Pageant is running. Requesting keys.");
3033 /* Request the keys held by the agent. */
3034 PUT_32BIT(request, 1);
3035 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3036 agent_query(request, 5, &r, &responselen);
3037 response = (unsigned char *)r;
3040 nkeys = GET_32BIT(p); p += 4;
3041 { char buf[64]; sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3043 for (i = 0; i < nkeys; i++) {
3044 static char *pkblob, *alg, *commentp;
3045 static int pklen, alglen, commentlen;
3046 static int siglen, retlen, len;
3047 static char *q, *agentreq, *ret;
3049 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
3051 pklen = GET_32BIT(p); p += 4;
3052 pkblob = p; p += pklen;
3053 alglen = GET_32BIT(pkblob);
3055 commentlen = GET_32BIT(p); p += 4;
3056 commentp = p; p += commentlen;
3057 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3058 ssh2_pkt_addstring(username);
3059 ssh2_pkt_addstring("ssh-connection");/* service requested */
3060 ssh2_pkt_addstring("publickey");/* method */
3061 ssh2_pkt_addbool(FALSE); /* no signature included */
3062 ssh2_pkt_addstring_start();
3063 ssh2_pkt_addstring_data(alg, alglen);
3064 ssh2_pkt_addstring_start();
3065 ssh2_pkt_addstring_data(pkblob, pklen);
3068 crWaitUntilV(ispkt);
3069 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3070 logevent("Key refused");
3074 c_write_str("Authenticating with public key \"");
3075 c_write(commentp, commentlen);
3076 c_write_str("\" from agent\r\n");
3079 * Server is willing to accept the key.
3080 * Construct a SIGN_REQUEST.
3082 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3083 ssh2_pkt_addstring(username);
3084 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3085 ssh2_pkt_addstring("publickey"); /* method */
3086 ssh2_pkt_addbool(TRUE);
3087 ssh2_pkt_addstring_start();
3088 ssh2_pkt_addstring_data(alg, alglen);
3089 ssh2_pkt_addstring_start();
3090 ssh2_pkt_addstring_data(pkblob, pklen);
3092 siglen = pktout.length - 5 + 4 + 20;
3093 len = 1; /* message type */
3094 len += 4 + pklen; /* key blob */
3095 len += 4 + siglen; /* data to sign */
3096 len += 4; /* flags */
3097 agentreq = smalloc(4 + len);
3098 PUT_32BIT(agentreq, len);
3100 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3101 PUT_32BIT(q, pklen); q += 4;
3102 memcpy(q, pkblob, pklen); q += pklen;
3103 PUT_32BIT(q, siglen); q += 4;
3104 /* Now the data to be signed... */
3105 PUT_32BIT(q, 20); q += 4;
3106 memcpy(q, ssh2_session_id, 20); q += 20;
3107 memcpy(q, pktout.data+5, pktout.length-5);
3108 q += pktout.length-5;
3109 /* And finally the (zero) flags word. */
3111 agent_query(agentreq, len+4, &ret, &retlen);
3114 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3115 logevent("Sending Pageant's response");
3116 ssh2_pkt_addstring_start();
3117 ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5));
3122 logevent("Pageant failed to answer challenge");
3132 if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) {
3133 unsigned char *pub_blob;
3134 char *algorithm, *comment;
3137 tried_pubkey_config = TRUE;
3140 * Try the public key supplied in the configuration.
3142 * First, offer the public blob to see if the server is
3143 * willing to accept it.
3145 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3148 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3149 ssh2_pkt_addstring(username);
3150 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3151 ssh2_pkt_addstring("publickey");/* method */
3152 ssh2_pkt_addbool(FALSE); /* no signature included */
3153 ssh2_pkt_addstring(algorithm);
3154 ssh2_pkt_addstring_start();
3155 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3157 logevent("Offered public key"); /* FIXME */
3159 crWaitUntilV(ispkt);
3160 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3162 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3163 continue; /* key refused; give up on it */
3166 logevent("Offer of public key accepted");
3168 * Actually attempt a serious authentication using
3171 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3172 sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment);
3177 c_write_str("Authenticating with public key \"");
3178 c_write_str(comment);
3179 c_write_str("\"\r\n");
3180 method = AUTH_PUBLICKEY_FILE;
3184 if (!method && can_passwd) {
3185 method = AUTH_PASSWORD;
3186 sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost);
3192 if (!ssh_get_line(pwprompt, password,
3193 sizeof(password), TRUE)) {
3195 * get_line failed to get a password (for
3196 * example because one was supplied on the
3197 * command line which has already failed to
3200 logevent("No more passwords to try");
3201 ssh_state = SSH_STATE_CLOSED;
3208 c_write_str(pwprompt);
3213 crWaitUntilV(!ispkt);
3214 while (inlen--) switch (c = *in++) {
3231 if (((c >= ' ' && c <= '~') ||
3232 ((unsigned char)c >= 160)) && pos < 40)
3233 password[pos++] = c;
3237 c_write_str("\r\n");
3241 if (method == AUTH_PUBLICKEY_FILE) {
3243 * We have our passphrase. Now try the actual authentication.
3245 struct ssh2_userkey *key;
3247 key = ssh2_load_userkey(cfg.keyfile, password);
3248 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3249 if (key == SSH2_WRONG_PASSPHRASE) {
3250 c_write_str("Wrong passphrase\r\n");
3251 tried_pubkey_config = FALSE;
3253 c_write_str("Unable to load private key\r\n");
3254 tried_pubkey_config = TRUE;
3256 /* Send a spurious AUTH_NONE to return to the top. */
3257 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3258 ssh2_pkt_addstring(username);
3259 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3260 ssh2_pkt_addstring("none"); /* method */
3262 type = AUTH_TYPE_NONE;
3264 unsigned char *blob, *sigdata;
3265 int blob_len, sigdata_len;
3268 * We have loaded the private key and the server
3269 * has announced that it's willing to accept it.
3270 * Hallelujah. Generate a signature and send it.
3272 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3273 ssh2_pkt_addstring(username);
3274 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3275 ssh2_pkt_addstring("publickey"); /* method */
3276 ssh2_pkt_addbool(TRUE);
3277 ssh2_pkt_addstring(key->alg->name);
3278 blob = key->alg->public_blob(key->data, &blob_len);
3279 ssh2_pkt_addstring_start();
3280 ssh2_pkt_addstring_data(blob, blob_len);
3284 * The data to be signed is:
3288 * followed by everything so far placed in the
3291 sigdata_len = pktout.length - 5 + 4 + 20;
3292 sigdata = smalloc(sigdata_len);
3293 PUT_32BIT(sigdata, 20);
3294 memcpy(sigdata+4, ssh2_session_id, 20);
3295 memcpy(sigdata+24, pktout.data+5, pktout.length-5);
3296 blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len);
3297 ssh2_pkt_addstring_start();
3298 ssh2_pkt_addstring_data(blob, blob_len);
3303 type = AUTH_TYPE_PUBLICKEY;
3305 } else if (method == AUTH_PASSWORD) {
3307 * We send the password packet lumped tightly together with
3308 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3309 * string long enough to make the total length of the two
3310 * packets constant. This should ensure that a passive
3311 * listener doing traffic analyis can't work out the length
3314 * For this to work, we need an assumption about the
3315 * maximum length of the password packet. I think 256 is
3316 * pretty conservative. Anyone using a password longer than
3317 * that probably doesn't have much to worry about from
3318 * people who find out how long their password is!
3320 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3321 ssh2_pkt_addstring(username);
3322 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3323 ssh2_pkt_addstring("password");
3324 ssh2_pkt_addbool(FALSE);
3325 ssh2_pkt_addstring(password);
3328 * We'll include a string that's an exact multiple of the
3329 * cipher block size. If the cipher is NULL for some
3330 * reason, we don't do this trick at all because we gain
3336 stringlen = (256 - deferred_len);
3337 stringlen += cscipher->blksize - 1;
3338 stringlen -= (stringlen % cscipher->blksize);
3341 * Temporarily disable actual compression,
3342 * so we can guarantee to get this string
3343 * exactly the length we want it. The
3344 * compression-disabling routine should
3345 * return an integer indicating how many
3346 * bytes we should adjust our string length
3349 stringlen -= cscomp->disable_compression();
3351 ssh2_pkt_init(SSH2_MSG_IGNORE);
3352 ssh2_pkt_addstring_start();
3353 for (i = 0; i < stringlen; i++) {
3354 char c = (char)random_byte();
3355 ssh2_pkt_addstring_data(&c, 1);
3359 ssh_pkt_defersend();
3360 logevent("Sent password");
3361 type = AUTH_TYPE_PASSWORD;
3363 c_write_str("No supported authentication methods left to try!\r\n");
3364 logevent("No supported authentications offered. Disconnecting");
3365 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3366 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3367 ssh2_pkt_addstring("No supported authentication methods available");
3368 ssh2_pkt_addstring("en"); /* language tag */
3370 ssh_state = SSH_STATE_CLOSED;
3374 } while (!we_are_in);
3377 * Now we're authenticated for the connection protocol. The
3378 * connection protocol will automatically have started at this
3379 * point; there's no need to send SERVICE_REQUEST.
3383 * So now create a channel with a session in it.
3385 mainchan = smalloc(sizeof(struct ssh_channel));
3386 mainchan->localid = 100; /* as good as any */
3387 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3388 ssh2_pkt_addstring("session");
3389 ssh2_pkt_adduint32(mainchan->localid);
3390 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3391 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3393 crWaitUntilV(ispkt);
3394 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
3395 bombout(("Server refused to open a session"));
3397 /* FIXME: error data comes back in FAILURE packet */
3399 if (ssh2_pkt_getuint32() != mainchan->localid) {
3400 bombout(("Server's channel confirmation cited wrong channel"));
3403 mainchan->remoteid = ssh2_pkt_getuint32();
3404 mainchan->type = CHAN_MAINSESSION;
3405 mainchan->closes = 0;
3406 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3407 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3408 mainchan->v2.outbuffer = NULL;
3409 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3410 ssh_channels = newtree234(ssh_channelcmp);
3411 add234(ssh_channels, mainchan);
3412 logevent("Opened channel for session");
3415 * Potentially enable X11 forwarding.
3417 if (cfg.x11_forward) {
3418 char proto[20], data[64];
3419 logevent("Requesting X11 forwarding");
3420 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3421 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3422 ssh2_pkt_adduint32(mainchan->remoteid);
3423 ssh2_pkt_addstring("x11-req");
3424 ssh2_pkt_addbool(1); /* want reply */
3425 ssh2_pkt_addbool(0); /* many connections */
3426 ssh2_pkt_addstring(proto);
3427 ssh2_pkt_addstring(data);
3428 ssh2_pkt_adduint32(0); /* screen number */
3432 crWaitUntilV(ispkt);
3433 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3434 unsigned i = ssh2_pkt_getuint32();
3435 struct ssh_channel *c;
3436 c = find234(ssh_channels, &i, ssh_channelfind);
3438 continue; /* nonexistent channel */
3439 c->v2.remwindow += ssh2_pkt_getuint32();
3441 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3443 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3444 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3445 bombout(("Server got confused by X11 forwarding request"));
3448 logevent("X11 forwarding refused");
3450 logevent("X11 forwarding enabled");
3451 ssh_X11_fwd_enabled = TRUE;
3456 * Potentially enable agent forwarding.
3458 if (cfg.agentfwd && agent_exists()) {
3459 char proto[20], data[64];
3460 logevent("Requesting OpenSSH-style agent forwarding");
3461 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3462 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3463 ssh2_pkt_adduint32(mainchan->remoteid);
3464 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3465 ssh2_pkt_addbool(1); /* want reply */
3469 crWaitUntilV(ispkt);
3470 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3471 unsigned i = ssh2_pkt_getuint32();
3472 struct ssh_channel *c;
3473 c = find234(ssh_channels, &i, ssh_channelfind);
3475 continue; /* nonexistent channel */
3476 c->v2.remwindow += ssh2_pkt_getuint32();
3478 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3480 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3481 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3482 bombout(("Server got confused by agent forwarding request"));
3485 logevent("Agent forwarding refused");
3487 logevent("Agent forwarding enabled");
3488 ssh_agentfwd_enabled = TRUE;
3493 * Now allocate a pty for the session.
3496 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3497 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3498 ssh2_pkt_addstring("pty-req");
3499 ssh2_pkt_addbool(1); /* want reply */
3500 ssh2_pkt_addstring(cfg.termtype);
3501 ssh2_pkt_adduint32(cols);
3502 ssh2_pkt_adduint32(rows);
3503 ssh2_pkt_adduint32(0); /* pixel width */
3504 ssh2_pkt_adduint32(0); /* pixel height */
3505 ssh2_pkt_addstring_start();
3506 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3508 ssh_state = SSH_STATE_INTERMED;
3511 crWaitUntilV(ispkt);
3512 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3513 unsigned i = ssh2_pkt_getuint32();
3514 struct ssh_channel *c;
3515 c = find234(ssh_channels, &i, ssh_channelfind);
3517 continue; /* nonexistent channel */
3518 c->v2.remwindow += ssh2_pkt_getuint32();
3520 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3522 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3523 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3524 bombout(("Server got confused by pty request"));
3527 c_write_str("Server refused to allocate pty\r\n");
3528 ssh_editing = ssh_echoing = 1;
3530 logevent("Allocated pty");
3533 ssh_editing = ssh_echoing = 1;
3537 * Start a shell or a remote command.
3539 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3540 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3541 if (cfg.ssh_subsys) {
3542 ssh2_pkt_addstring("subsystem");
3543 ssh2_pkt_addbool(1); /* want reply */
3544 ssh2_pkt_addstring(cfg.remote_cmd);
3545 } else if (*cfg.remote_cmd) {
3546 ssh2_pkt_addstring("exec");
3547 ssh2_pkt_addbool(1); /* want reply */
3548 ssh2_pkt_addstring(cfg.remote_cmd);
3550 ssh2_pkt_addstring("shell");
3551 ssh2_pkt_addbool(1); /* want reply */
3555 crWaitUntilV(ispkt);
3556 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3557 unsigned i = ssh2_pkt_getuint32();
3558 struct ssh_channel *c;
3559 c = find234(ssh_channels, &i, ssh_channelfind);
3561 continue; /* nonexistent channel */
3562 c->v2.remwindow += ssh2_pkt_getuint32();
3564 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3565 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3566 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3567 bombout(("Server got confused by shell/command request"));
3570 bombout(("Server refused to start a shell/command"));
3573 logevent("Started a shell/command");
3576 ssh_state = SSH_STATE_SESSION;
3580 ssh_special(TS_EOF);
3585 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
3588 static int try_send;
3592 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3593 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3596 unsigned i = ssh2_pkt_getuint32();
3597 struct ssh_channel *c;
3598 c = find234(ssh_channels, &i, ssh_channelfind);
3600 continue; /* nonexistent channel */
3601 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3602 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3603 continue; /* extended but not stderr */
3604 ssh2_pkt_getstring(&data, &length);
3607 case CHAN_MAINSESSION:
3608 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
3612 x11_send(c->u.x11.s, data, length);
3615 while (length > 0) {
3616 if (c->u.a.lensofar < 4) {
3617 int l = min(4 - c->u.a.lensofar, length);
3618 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
3619 data += l; length -= l; c->u.a.lensofar += l;
3621 if (c->u.a.lensofar == 4) {
3622 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
3623 c->u.a.message = smalloc(c->u.a.totallen);
3624 memcpy(c->u.a.message, c->u.a.msglen, 4);
3626 if (c->u.a.lensofar >= 4 && length > 0) {
3627 int l = min(c->u.a.totallen - c->u.a.lensofar,
3629 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
3630 data += l; length -= l; c->u.a.lensofar += l;
3632 if (c->u.a.lensofar == c->u.a.totallen) {
3633 void *reply, *sentreply;
3635 agent_query(c->u.a.message, c->u.a.totallen,
3640 /* Fake SSH_AGENT_FAILURE. */
3641 sentreply = "\0\0\0\1\5";
3644 ssh2_add_channel_data(c, sentreply, replylen);
3648 sfree(c->u.a.message);
3649 c->u.a.lensofar = 0;
3655 * Enlarge the window again at the remote
3656 * side, just in case it ever runs down and
3657 * they fail to send us any more data.
3659 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3660 ssh2_pkt_adduint32(c->remoteid);
3661 ssh2_pkt_adduint32(length);
3664 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
3665 ssh_state = SSH_STATE_CLOSED;
3666 logevent("Received disconnect message");
3668 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
3669 continue; /* exit status et al; ignore (FIXME?) */
3670 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
3671 unsigned i = ssh2_pkt_getuint32();
3672 struct ssh_channel *c;
3674 c = find234(ssh_channels, &i, ssh_channelfind);
3676 continue; /* nonexistent channel */
3678 if (c->type == CHAN_X11) {
3680 * Remote EOF on an X11 channel means we should
3681 * wrap up and close the channel ourselves.
3683 x11_close(c->u.x11.s);
3685 } else if (c->type == CHAN_AGENT) {
3688 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
3689 unsigned i = ssh2_pkt_getuint32();
3690 struct ssh_channel *c;
3693 c = find234(ssh_channels, &i, ssh_channelfind);
3695 continue; /* nonexistent channel */
3696 if (c->closes == 0) {
3697 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3698 ssh2_pkt_adduint32(c->remoteid);
3701 /* Do pre-close processing on the channel. */
3703 case CHAN_MAINSESSION:
3704 break; /* nothing to see here, move along */
3710 del234(ssh_channels, c);
3711 sfree(c->v2.outbuffer);
3715 * See if that was the last channel left open.
3717 c = first234(ssh_channels, &e);
3719 logevent("All channels closed. Disconnecting");
3720 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3721 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3722 ssh2_pkt_addstring("All open channels closed");
3723 ssh2_pkt_addstring("en"); /* language tag */
3725 ssh_state = SSH_STATE_CLOSED;
3728 continue; /* remote sends close; ignore (FIXME) */
3729 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3730 unsigned i = ssh2_pkt_getuint32();
3731 struct ssh_channel *c;
3732 c = find234(ssh_channels, &i, ssh_channelfind);
3734 continue; /* nonexistent channel */
3735 mainchan->v2.remwindow += ssh2_pkt_getuint32();
3737 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3741 struct ssh_channel *c;
3742 ssh2_pkt_getstring(&type, &typelen);
3743 c = smalloc(sizeof(struct ssh_channel));
3745 if (typelen == 3 && !memcmp(type, "x11", 3)) {
3746 if (!ssh_X11_fwd_enabled)
3747 error = "X11 forwarding is not enabled";
3748 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
3749 error = "Unable to open an X11 connection";
3753 } else if (typelen == 22 &&
3754 !memcmp(type, "auth-agent@openssh.com", 3)) {
3755 if (!ssh_agentfwd_enabled)
3756 error = "Agent forwarding is not enabled";
3758 c->type = CHAN_AGENT; /* identify channel type */
3759 c->u.a.lensofar = 0;
3762 error = "Unsupported channel type requested";
3765 c->remoteid = ssh2_pkt_getuint32();
3767 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3768 ssh2_pkt_adduint32(c->remoteid);
3769 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3770 ssh2_pkt_addstring(error);
3771 ssh2_pkt_addstring("en"); /* language tag */
3775 struct ssh_channel *d;
3779 for (i=1, d = first234(ssh_channels, &e); d;
3782 break; /* found a free number */
3787 c->v2.remwindow = ssh2_pkt_getuint32();
3788 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3789 c->v2.outbuffer = NULL;
3790 c->v2.outbuflen = c->v2.outbufsize = 0;
3791 add234(ssh_channels, c);
3792 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3793 ssh2_pkt_adduint32(c->remoteid);
3794 ssh2_pkt_adduint32(c->localid);
3795 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3796 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3800 bombout(("Strange packet received: type %d", pktin.type));
3805 * We have spare data. Add it to the channel buffer.
3807 ssh2_add_channel_data(mainchan, in, inlen);
3812 struct ssh_channel *c;
3814 * Try to send data on all channels if we can.
3816 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3825 * Handle the top-level SSH2 protocol.
3827 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3829 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3831 do_ssh2_authconn(in, inlen, ispkt);
3835 * Called to set up the connection.
3837 * Returns an error message, or NULL on success.
3839 static char *ssh_init (char *host, int port, char **realhost) {
3843 if(crypto_startup() == 0)
3844 return "Microsoft high encryption pack not installed!";
3851 p = connect_to_host(host, port, realhost);
3859 * Called to send data down the Telnet connection.
3861 static void ssh_send (char *buf, int len) {
3862 if (s == NULL || ssh_protocol == NULL)
3865 ssh_protocol(buf, len, 0);
3869 * Called to set the size of the window from SSH's POV.
3871 static void ssh_size(void) {
3872 switch (ssh_state) {
3873 case SSH_STATE_BEFORE_SIZE:
3874 case SSH_STATE_PREPACKET:
3875 case SSH_STATE_CLOSED:
3876 break; /* do nothing */
3877 case SSH_STATE_INTERMED:
3878 size_needed = TRUE; /* buffer for later */
3880 case SSH_STATE_SESSION:
3882 if (ssh_version == 1) {
3883 send_packet(SSH1_CMSG_WINDOW_SIZE,
3884 PKT_INT, rows, PKT_INT, cols,
3885 PKT_INT, 0, PKT_INT, 0, PKT_END);
3887 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3888 ssh2_pkt_adduint32(mainchan->remoteid);
3889 ssh2_pkt_addstring("window-change");
3890 ssh2_pkt_addbool(0);
3891 ssh2_pkt_adduint32(cols);
3892 ssh2_pkt_adduint32(rows);
3893 ssh2_pkt_adduint32(0);
3894 ssh2_pkt_adduint32(0);
3903 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3904 * can send an EOF and collect resulting output (e.g. `plink
3907 static void ssh_special (Telnet_Special code) {
3908 if (code == TS_EOF) {
3909 if (ssh_state != SSH_STATE_SESSION) {
3911 * Buffer the EOF in case we are pre-SESSION, so we can
3912 * send it as soon as we reach SESSION.
3918 if (ssh_version == 1) {
3919 send_packet(SSH1_CMSG_EOF, PKT_END);
3921 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
3922 ssh2_pkt_adduint32(mainchan->remoteid);
3925 logevent("Sent EOF message");
3926 } else if (code == TS_PING) {
3927 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3929 if (ssh_version == 1) {
3930 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3932 ssh2_pkt_init(SSH2_MSG_IGNORE);
3933 ssh2_pkt_addstring_start();
3941 static Socket ssh_socket(void) { return s; }
3943 static int ssh_sendok(void) { return ssh_send_ok; }
3945 static int ssh_ldisc(int option) {
3946 if (option == LD_ECHO) return ssh_echoing;
3947 if (option == LD_EDIT) return ssh_editing;
3951 Backend ssh_backend = {