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 #ifdef DO_DIFFIE_HELLMAN_GEX
183 &ssh_diffiehellman_gex,
185 &ssh_diffiehellman };
187 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
189 static void nullmac_key(unsigned char *key) { }
190 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
191 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
192 const static struct ssh_mac ssh_mac_none = {
193 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
195 const static struct ssh_mac *macs[] = {
196 &ssh_sha1, &ssh_md5, &ssh_mac_none };
197 const static struct ssh_mac *buggymacs[] = {
198 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
200 static void ssh_comp_none_init(void) { }
201 static int ssh_comp_none_block(unsigned char *block, int len,
202 unsigned char **outblock, int *outlen) {
205 static int ssh_comp_none_disable(void) { return 0; }
206 const static struct ssh_compress ssh_comp_none = {
208 ssh_comp_none_init, ssh_comp_none_block,
209 ssh_comp_none_init, ssh_comp_none_block,
210 ssh_comp_none_disable
212 extern const struct ssh_compress ssh_zlib;
213 const static struct ssh_compress *compressions[] = {
214 &ssh_zlib, &ssh_comp_none };
216 enum { /* channel types */
223 * 2-3-4 tree storing channels.
226 unsigned remoteid, localid;
229 struct ssh2_data_channel {
230 unsigned char *outbuffer;
231 unsigned outbuflen, outbufsize;
232 unsigned remwindow, remmaxpkt;
235 struct ssh_agent_channel {
236 unsigned char *message;
237 unsigned char msglen[4];
238 int lensofar, totallen;
240 struct ssh_x11_channel {
255 static SHA_State exhash, exhashbase;
257 static Socket s = NULL;
259 static unsigned char session_key[32];
260 static int ssh1_compressing;
261 static int ssh_agentfwd_enabled;
262 static int ssh_X11_fwd_enabled;
263 static int ssh_remote_bugs;
264 static const struct ssh_cipher *cipher = NULL;
265 static const struct ssh2_cipher *cscipher = NULL;
266 static const struct ssh2_cipher *sccipher = NULL;
267 static const struct ssh_mac *csmac = NULL;
268 static const struct ssh_mac *scmac = NULL;
269 static const struct ssh_compress *cscomp = NULL;
270 static const struct ssh_compress *sccomp = NULL;
271 static const struct ssh_kex *kex = NULL;
272 static const struct ssh_signkey *hostkey = NULL;
273 static unsigned char ssh2_session_id[20];
274 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
276 static char *savedhost;
277 static int savedport;
278 static int ssh_send_ok;
279 static int ssh_echoing, ssh_editing;
281 static tree234 *ssh_channels; /* indexed by local id */
282 static struct ssh_channel *mainchan; /* primary session channel */
286 SSH_STATE_BEFORE_SIZE,
290 } ssh_state = SSH_STATE_PREPACKET;
292 static int size_needed = FALSE, eof_needed = FALSE;
294 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
295 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
296 static unsigned char *deferred_send_data = NULL;
297 static int deferred_len = 0, deferred_size = 0;
299 static int ssh_version;
300 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
301 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
302 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
303 static void ssh_size(void);
304 static void ssh_special (Telnet_Special);
305 static void ssh2_try_send(struct ssh_channel *c);
306 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
308 static int (*s_rdpkt)(unsigned char **data, int *datalen);
310 static struct rdpkt1_state_tag {
311 long len, pad, biglen, to_read;
312 unsigned long realcrc, gotcrc;
318 static struct rdpkt2_state_tag {
319 long len, pad, payload, packetlen, maclen;
322 unsigned long incoming_sequence;
325 static int ssh_channelcmp(void *av, void *bv) {
326 struct ssh_channel *a = (struct ssh_channel *)av;
327 struct ssh_channel *b = (struct ssh_channel *)bv;
328 if (a->localid < b->localid) return -1;
329 if (a->localid > b->localid) return +1;
332 static int ssh_channelfind(void *av, void *bv) {
333 unsigned *a = (unsigned *)av;
334 struct ssh_channel *b = (struct ssh_channel *)bv;
335 if (*a < b->localid) return -1;
336 if (*a > b->localid) return +1;
340 static void c_write (char *buf, int len) {
341 if ((flags & FLAG_STDERR)) {
343 for (i = 0; i < len; i++)
345 fputc(buf[i], stderr);
348 from_backend(1, buf, len);
351 static void c_write_str (char *buf) {
352 c_write(buf, strlen(buf));
356 * Collect incoming data in the incoming packet buffer.
357 * Decipher and verify the packet when it is completely read.
358 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
359 * Update the *data and *datalen variables.
360 * Return the additional nr of bytes needed, or 0 when
361 * a complete packet is available.
363 static int ssh1_rdpkt(unsigned char **data, int *datalen)
365 struct rdpkt1_state_tag *st = &rdpkt1_state;
374 for (st->i = st->len = 0; st->i < 4; st->i++) {
375 while ((*datalen) == 0)
377 st->len = (st->len << 8) + **data;
378 (*data)++, (*datalen)--;
382 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
383 st->len = 0x300; /* big enough to carry to end */
387 st->pad = 8 - (st->len % 8);
388 st->biglen = st->len + st->pad;
389 pktin.length = st->len - 5;
391 if (pktin.maxlen < st->biglen) {
392 pktin.maxlen = st->biglen;
393 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
394 srealloc(pktin.data, st->biglen+APIEXTRA));
396 fatalbox("Out of memory");
399 st->to_read = st->biglen;
401 while (st->to_read > 0) {
402 st->chunk = st->to_read;
403 while ((*datalen) == 0)
404 crReturn(st->to_read);
405 if (st->chunk > (*datalen))
406 st->chunk = (*datalen);
407 memcpy(st->p, *data, st->chunk);
409 *datalen -= st->chunk;
411 st->to_read -= st->chunk;
415 cipher->decrypt(pktin.data, st->biglen);
417 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
418 for (st->i = 0; st->i < st->biglen; st->i++)
419 debug((" %02x", (unsigned char)pktin.data[st->i]));
423 st->realcrc = crc32(pktin.data, st->biglen-4);
424 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
425 if (st->gotcrc != st->realcrc) {
426 bombout(("Incorrect CRC received on packet"));
430 pktin.body = pktin.data + st->pad + 1;
432 if (ssh1_compressing) {
433 unsigned char *decompblk;
437 debug(("Packet payload pre-decompression:\n"));
438 for (i = -1; i < pktin.length; i++)
439 debug((" %02x", (unsigned char)pktin.body[i]));
442 zlib_decompress_block(pktin.body-1, pktin.length+1,
443 &decompblk, &decomplen);
445 if (pktin.maxlen < st->pad + decomplen) {
446 pktin.maxlen = st->pad + decomplen;
447 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
448 pktin.body = pktin.data + st->pad + 1;
450 fatalbox("Out of memory");
453 memcpy(pktin.body-1, decompblk, decomplen);
455 pktin.length = decomplen-1;
457 debug(("Packet payload post-decompression:\n"));
458 for (i = -1; i < pktin.length; i++)
459 debug((" %02x", (unsigned char)pktin.body[i]));
464 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
465 pktin.type == SSH1_SMSG_STDERR_DATA ||
466 pktin.type == SSH1_MSG_DEBUG ||
467 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
468 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
469 long strlen = GET_32BIT(pktin.body);
470 if (strlen + 4 != pktin.length) {
471 bombout(("Received data packet with bogus string length"));
476 pktin.type = pktin.body[-1];
478 if (pktin.type == SSH1_MSG_DEBUG) {
479 /* log debug message */
481 int strlen = GET_32BIT(pktin.body);
482 strcpy(buf, "Remote: ");
483 if (strlen > 70) strlen = 70;
484 memcpy(buf+8, pktin.body+4, strlen);
485 buf[8+strlen] = '\0';
488 } else if (pktin.type == SSH1_MSG_IGNORE) {
496 static int ssh2_rdpkt(unsigned char **data, int *datalen)
498 struct rdpkt2_state_tag *st = &rdpkt2_state;
506 st->cipherblk = sccipher->blksize;
509 if (st->cipherblk < 8)
512 if (pktin.maxlen < st->cipherblk) {
513 pktin.maxlen = st->cipherblk;
514 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
515 srealloc(pktin.data, st->cipherblk+APIEXTRA));
517 fatalbox("Out of memory");
521 * Acquire and decrypt the first block of the packet. This will
522 * contain the length and padding details.
524 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
525 while ((*datalen) == 0)
526 crReturn(st->cipherblk-st->i);
527 pktin.data[st->i] = *(*data)++;
531 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
536 sccipher->decrypt(pktin.data, st->cipherblk);
539 * Now get the length and padding figures.
541 st->len = GET_32BIT(pktin.data);
542 st->pad = pktin.data[4];
545 * This enables us to deduce the payload length.
547 st->payload = st->len - st->pad - 1;
549 pktin.length = st->payload + 5;
552 * So now we can work out the total packet length.
554 st->packetlen = st->len + 4;
555 st->maclen = scmac ? scmac->len : 0;
558 * Adjust memory allocation if packet is too big.
560 if (pktin.maxlen < st->packetlen+st->maclen) {
561 pktin.maxlen = st->packetlen+st->maclen;
562 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
563 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
565 fatalbox("Out of memory");
569 * Read and decrypt the remainder of the packet.
571 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
572 while ((*datalen) == 0)
573 crReturn(st->packetlen + st->maclen - st->i);
574 pktin.data[st->i] = *(*data)++;
577 /* Decrypt everything _except_ the MAC. */
579 sccipher->decrypt(pktin.data + st->cipherblk,
580 st->packetlen - st->cipherblk);
583 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
584 for (st->i = 0; st->i < st->packetlen; st->i++)
585 debug((" %02x", (unsigned char)pktin.data[st->i]));
592 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
593 bombout(("Incorrect MAC received on packet"));
596 st->incoming_sequence++; /* whether or not we MACed */
599 * Decompress packet payload.
602 unsigned char *newpayload;
604 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
605 &newpayload, &newlen)) {
606 if (pktin.maxlen < newlen+5) {
607 pktin.maxlen = newlen+5;
608 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
609 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
611 fatalbox("Out of memory");
613 pktin.length = 5 + newlen;
614 memcpy(pktin.data+5, newpayload, newlen);
616 debug(("Post-decompression payload:\r\n"));
617 for (st->i = 0; st->i < newlen; st->i++)
618 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
627 pktin.type = pktin.data[5];
629 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
630 goto next_packet; /* FIXME: print DEBUG message */
635 static void ssh1_pktout_size(int len) {
638 len += 5; /* type and CRC */
642 pktout.length = len-5;
643 if (pktout.maxlen < biglen) {
644 pktout.maxlen = biglen;
646 /* Allocate enough buffer space for extra block
647 * for MS CryptEncrypt() */
648 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
649 srealloc(pktout.data, biglen+12));
651 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
652 srealloc(pktout.data, biglen+4));
655 fatalbox("Out of memory");
657 pktout.body = pktout.data+4+pad+1;
660 static void s_wrpkt_start(int type, int len) {
661 ssh1_pktout_size(len);
665 static int s_wrpkt_prepare(void) {
666 int pad, len, biglen, i;
669 pktout.body[-1] = pktout.type;
672 debug(("Packet payload pre-compression:\n"));
673 for (i = -1; i < pktout.length; i++)
674 debug((" %02x", (unsigned char)pktout.body[i]));
678 if (ssh1_compressing) {
679 unsigned char *compblk;
681 zlib_compress_block(pktout.body-1, pktout.length+1,
683 ssh1_pktout_size(complen-1);
684 memcpy(pktout.body-1, compblk, complen);
687 debug(("Packet payload post-compression:\n"));
688 for (i = -1; i < pktout.length; i++)
689 debug((" %02x", (unsigned char)pktout.body[i]));
694 len = pktout.length + 5; /* type and CRC */
698 for (i=0; i<pad; i++)
699 pktout.data[i+4] = random_byte();
700 crc = crc32(pktout.data+4, biglen-4);
701 PUT_32BIT(pktout.data+biglen, crc);
702 PUT_32BIT(pktout.data, len);
705 debug(("Sending packet len=%d\r\n", biglen+4));
706 for (i = 0; i < biglen+4; i++)
707 debug((" %02x", (unsigned char)pktout.data[i]));
711 cipher->encrypt(pktout.data+4, biglen);
716 static void s_wrpkt(void) {
718 len = s_wrpkt_prepare();
719 sk_write(s, pktout.data, len);
722 static void s_wrpkt_defer(void) {
724 len = s_wrpkt_prepare();
725 if (deferred_len + len > deferred_size) {
726 deferred_size = deferred_len + len + 128;
727 deferred_send_data = srealloc(deferred_send_data, deferred_size);
729 memcpy(deferred_send_data+deferred_len, pktout.data, len);
734 * Construct a packet with the specified contents.
736 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
738 unsigned char *p, *argp, argchar;
739 unsigned long argint;
740 int pktlen, argtype, arglen;
744 while ((argtype = va_arg(ap1, int)) != PKT_END) {
747 (void) va_arg(ap1, int);
751 (void) va_arg(ap1, char);
755 (void) va_arg(ap1, unsigned char *);
756 arglen = va_arg(ap1, int);
760 argp = va_arg(ap1, unsigned char *);
761 arglen = strlen(argp);
762 pktlen += 4 + arglen;
765 bn = va_arg(ap1, Bignum);
766 pktlen += ssh1_bignum_length(bn);
773 s_wrpkt_start(pkttype, pktlen);
776 while ((argtype = va_arg(ap2, int)) != PKT_END) {
779 argint = va_arg(ap2, int);
780 PUT_32BIT(p, argint);
784 argchar = va_arg(ap2, unsigned char);
789 argp = va_arg(ap2, unsigned char *);
790 arglen = va_arg(ap2, int);
791 memcpy(p, argp, arglen);
795 argp = va_arg(ap2, unsigned char *);
796 arglen = strlen(argp);
797 PUT_32BIT(p, arglen);
798 memcpy(p + 4, argp, arglen);
802 bn = va_arg(ap2, Bignum);
803 p += ssh1_write_bignum(p, bn);
809 static void send_packet(int pkttype, ...) {
811 va_start(ap1, pkttype);
812 va_start(ap2, pkttype);
813 construct_packet(pkttype, ap1, ap2);
817 static void defer_packet(int pkttype, ...) {
819 va_start(ap1, pkttype);
820 va_start(ap2, pkttype);
821 construct_packet(pkttype, ap1, ap2);
825 static int ssh_versioncmp(char *a, char *b) {
827 unsigned long av, bv;
829 av = strtoul(a, &ae, 10);
830 bv = strtoul(b, &be, 10);
831 if (av != bv) return (av < bv ? -1 : +1);
832 if (*ae == '.') ae++;
833 if (*be == '.') be++;
834 av = strtoul(ae, &ae, 10);
835 bv = strtoul(be, &be, 10);
836 if (av != bv) return (av < bv ? -1 : +1);
842 * Utility routines for putting an SSH-protocol `string' and
843 * `uint32' into a SHA state.
846 static void sha_string(SHA_State *s, void *str, int len) {
847 unsigned char lenblk[4];
848 PUT_32BIT(lenblk, len);
849 SHA_Bytes(s, lenblk, 4);
850 SHA_Bytes(s, str, len);
853 static void sha_uint32(SHA_State *s, unsigned i) {
854 unsigned char intblk[4];
855 PUT_32BIT(intblk, i);
856 SHA_Bytes(s, intblk, 4);
860 * SSH2 packet construction functions.
862 static void ssh2_pkt_ensure(int length) {
863 if (pktout.maxlen < length) {
864 pktout.maxlen = length + 256;
865 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
866 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
868 fatalbox("Out of memory");
871 static void ssh2_pkt_adddata(void *data, int len) {
872 pktout.length += len;
873 ssh2_pkt_ensure(pktout.length);
874 memcpy(pktout.data+pktout.length-len, data, len);
876 static void ssh2_pkt_addbyte(unsigned char byte) {
877 ssh2_pkt_adddata(&byte, 1);
879 static void ssh2_pkt_init(int pkt_type) {
881 ssh2_pkt_addbyte((unsigned char)pkt_type);
883 static void ssh2_pkt_addbool(unsigned char value) {
884 ssh2_pkt_adddata(&value, 1);
886 static void ssh2_pkt_adduint32(unsigned long value) {
889 ssh2_pkt_adddata(x, 4);
891 static void ssh2_pkt_addstring_start(void) {
892 ssh2_pkt_adduint32(0);
893 pktout.savedpos = pktout.length;
895 static void ssh2_pkt_addstring_str(char *data) {
896 ssh2_pkt_adddata(data, strlen(data));
897 PUT_32BIT(pktout.data + pktout.savedpos - 4,
898 pktout.length - pktout.savedpos);
900 static void ssh2_pkt_addstring_data(char *data, int len) {
901 ssh2_pkt_adddata(data, len);
902 PUT_32BIT(pktout.data + pktout.savedpos - 4,
903 pktout.length - pktout.savedpos);
905 static void ssh2_pkt_addstring(char *data) {
906 ssh2_pkt_addstring_start();
907 ssh2_pkt_addstring_str(data);
909 static char *ssh2_mpint_fmt(Bignum b, int *len) {
911 int i, n = (ssh1_bignum_bitcount(b)+7)/8;
914 fatalbox("out of memory");
916 for (i = 1; i <= n; i++)
917 p[i] = bignum_byte(b, n-i);
919 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
921 memmove(p, p+i, n+1-i);
925 static void ssh2_pkt_addmp(Bignum b) {
928 p = ssh2_mpint_fmt(b, &len);
929 ssh2_pkt_addstring_start();
930 ssh2_pkt_addstring_data(p, len);
935 * Construct an SSH2 final-form packet: compress it, encrypt it,
936 * put the MAC on it. Final packet, ready to be sent, is stored in
937 * pktout.data. Total length is returned.
939 static int ssh2_pkt_construct(void) {
940 int cipherblk, maclen, padding, i;
941 static unsigned long outgoing_sequence = 0;
944 * Compress packet payload.
947 debug(("Pre-compression payload:\r\n"));
948 for (i = 5; i < pktout.length; i++)
949 debug((" %02x", (unsigned char)pktout.data[i]));
953 unsigned char *newpayload;
955 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
956 &newpayload, &newlen)) {
958 ssh2_pkt_adddata(newpayload, newlen);
964 * Add padding. At least four bytes, and must also bring total
965 * length (minus MAC) up to a multiple of the block size.
967 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
968 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
970 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
971 maclen = csmac ? csmac->len : 0;
972 ssh2_pkt_ensure(pktout.length + padding + maclen);
973 pktout.data[4] = padding;
974 for (i = 0; i < padding; i++)
975 pktout.data[pktout.length + i] = random_byte();
976 PUT_32BIT(pktout.data, pktout.length + padding - 4);
978 csmac->generate(pktout.data, pktout.length + padding,
980 outgoing_sequence++; /* whether or not we MACed */
983 debug(("Sending packet len=%d\r\n", pktout.length+padding));
984 for (i = 0; i < pktout.length+padding; i++)
985 debug((" %02x", (unsigned char)pktout.data[i]));
990 cscipher->encrypt(pktout.data, pktout.length + padding);
992 /* Ready-to-send packet starts at pktout.data. We return length. */
993 return pktout.length + padding + maclen;
997 * Construct and send an SSH2 packet immediately.
999 static void ssh2_pkt_send(void) {
1000 int len = ssh2_pkt_construct();
1001 sk_write(s, pktout.data, len);
1005 * Construct an SSH2 packet and add it to a deferred data block.
1006 * Useful for sending multiple packets in a single sk_write() call,
1007 * to prevent a traffic-analysing listener from being able to work
1008 * out the length of any particular packet (such as the password
1011 * Note that because SSH2 sequence-numbers its packets, this can
1012 * NOT be used as an m4-style `defer' allowing packets to be
1013 * constructed in one order and sent in another.
1015 static void ssh2_pkt_defer(void) {
1016 int len = ssh2_pkt_construct();
1017 if (deferred_len + len > deferred_size) {
1018 deferred_size = deferred_len + len + 128;
1019 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1021 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1022 deferred_len += len;
1026 * Send the whole deferred data block constructed by
1027 * ssh2_pkt_defer() or SSH1's defer_packet().
1029 static void ssh_pkt_defersend(void) {
1030 sk_write(s, deferred_send_data, deferred_len);
1031 deferred_len = deferred_size = 0;
1032 sfree(deferred_send_data);
1033 deferred_send_data = NULL;
1037 void bndebug(char *string, Bignum b) {
1040 p = ssh2_mpint_fmt(b, &len);
1041 debug(("%s", string));
1042 for (i = 0; i < len; i++)
1043 debug((" %02x", p[i]));
1049 static void sha_mpint(SHA_State *s, Bignum b) {
1052 p = ssh2_mpint_fmt(b, &len);
1053 sha_string(s, p, len);
1058 * SSH2 packet decode functions.
1060 static unsigned long ssh2_pkt_getuint32(void) {
1061 unsigned long value;
1062 if (pktin.length - pktin.savedpos < 4)
1063 return 0; /* arrgh, no way to decline (FIXME?) */
1064 value = GET_32BIT(pktin.data+pktin.savedpos);
1065 pktin.savedpos += 4;
1068 static int ssh2_pkt_getbool(void) {
1069 unsigned long value;
1070 if (pktin.length - pktin.savedpos < 1)
1071 return 0; /* arrgh, no way to decline (FIXME?) */
1072 value = pktin.data[pktin.savedpos] != 0;
1076 static void ssh2_pkt_getstring(char **p, int *length) {
1078 if (pktin.length - pktin.savedpos < 4)
1080 *length = GET_32BIT(pktin.data+pktin.savedpos);
1081 pktin.savedpos += 4;
1082 if (pktin.length - pktin.savedpos < *length)
1084 *p = pktin.data+pktin.savedpos;
1085 pktin.savedpos += *length;
1087 static Bignum ssh2_pkt_getmp(void) {
1092 ssh2_pkt_getstring(&p, &length);
1096 bombout(("internal error: Can't handle negative mpints"));
1099 b = bignum_from_bytes(p, length);
1104 * Examine the remote side's version string and compare it against
1105 * a list of known buggy implementations.
1107 static void ssh_detect_bugs(char *vstring) {
1108 char *imp; /* pointer to implementation part */
1110 imp += strcspn(imp, "-");
1111 imp += strcspn(imp, "-");
1113 ssh_remote_bugs = 0;
1115 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1116 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1117 !strcmp(imp, "1.2.22")) {
1119 * These versions don't support SSH1_MSG_IGNORE, so we have
1120 * to use a different defence against password length
1123 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1124 logevent("We believe remote version has SSH1 ignore bug");
1127 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1128 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1129 !strncmp(imp, "2.1 ", 4)) {
1131 * These versions have the HMAC bug.
1133 ssh_remote_bugs |= BUG_SSH2_HMAC;
1134 logevent("We believe remote version has SSH2 HMAC bug");
1138 static int do_ssh_init(unsigned char c) {
1140 static char version[10];
1141 static char vstring[80];
1142 static char vlog[sizeof(vstring)+20];
1147 /* Search for the string "SSH-" in the input. */
1150 static const int transS[] = { 1, 2, 2, 1 };
1151 static const int transH[] = { 0, 0, 3, 0 };
1152 static const int transminus[] = { 0, 0, 0, -1 };
1153 if (c == 'S') i = transS[i];
1154 else if (c == 'H') i = transH[i];
1155 else if (c == '-') i = transminus[i];
1159 crReturn(1); /* get another character */
1162 strcpy(vstring, "SSH-");
1166 crReturn(1); /* get another char */
1167 if (vsp < vstring+sizeof(vstring)-1)
1173 } else if (i < sizeof(version)-1)
1180 ssh_agentfwd_enabled = FALSE;
1181 rdpkt2_state.incoming_sequence = 0;
1184 sprintf(vlog, "Server version: %s", vstring);
1185 ssh_detect_bugs(vstring);
1186 vlog[strcspn(vlog, "\r\n")] = '\0';
1190 * Server version "1.99" means we can choose whether we use v1
1191 * or v2 protocol. Choice is based on cfg.sshprot.
1193 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1195 * This is a v2 server. Begin v2 protocol.
1197 char *verstring = "SSH-2.0-PuTTY";
1198 SHA_Init(&exhashbase);
1200 * Hash our version string and their version string.
1202 sha_string(&exhashbase, verstring, strlen(verstring));
1203 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1204 sprintf(vstring, "%s\n", verstring);
1205 sprintf(vlog, "We claim version: %s", verstring);
1207 logevent("Using SSH protocol version 2");
1208 sk_write(s, vstring, strlen(vstring));
1209 ssh_protocol = ssh2_protocol;
1211 s_rdpkt = ssh2_rdpkt;
1214 * This is a v1 server. Begin v1 protocol.
1216 sprintf(vstring, "SSH-%s-PuTTY\n",
1217 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1218 sprintf(vlog, "We claim version: %s", vstring);
1219 vlog[strcspn(vlog, "\r\n")] = '\0';
1221 logevent("Using SSH protocol version 1");
1222 sk_write(s, vstring, strlen(vstring));
1223 ssh_protocol = ssh1_protocol;
1225 s_rdpkt = ssh1_rdpkt;
1227 ssh_state = SSH_STATE_BEFORE_SIZE;
1232 static void ssh_gotdata(unsigned char *data, int datalen)
1237 * To begin with, feed the characters one by one to the
1238 * protocol initialisation / selection function do_ssh_init().
1239 * When that returns 0, we're done with the initial greeting
1240 * exchange and can move on to packet discipline.
1245 crReturnV; /* more data please */
1246 ret = do_ssh_init(*data);
1253 * We emerge from that loop when the initial negotiation is
1254 * over and we have selected an s_rdpkt function. Now pass
1255 * everything to s_rdpkt, and then pass the resulting packets
1256 * to the proper protocol handler.
1261 while (datalen > 0) {
1262 if ( s_rdpkt(&data, &datalen) == 0 ) {
1263 ssh_protocol(NULL, 0, 1);
1264 if (ssh_state == SSH_STATE_CLOSED) {
1274 static int ssh_receive(Socket skt, int urgent, char *data, int len) {
1276 /* A socket error has occurred. */
1277 ssh_state = SSH_STATE_CLOSED;
1280 connection_fatal(data);
1283 /* Connection has closed. */
1284 ssh_state = SSH_STATE_CLOSED;
1289 ssh_gotdata (data, len);
1290 if (ssh_state == SSH_STATE_CLOSED) {
1301 * Connect to specified host and port.
1302 * Returns an error message, or NULL on success.
1303 * Also places the canonical host name into `realhost'.
1305 static char *connect_to_host(char *host, int port, char **realhost)
1314 savedhost = smalloc(1+strlen(host));
1316 fatalbox("Out of memory");
1317 strcpy(savedhost, host);
1320 port = 22; /* default ssh port */
1333 addr = sk_namelookup(host, realhost);
1334 if ( (err = sk_addr_error(addr)) )
1344 s = sk_new(addr, port, 0, 1, ssh_receive);
1345 if ( (err = sk_socket_error(s)) )
1349 sk_write(s, "connect ", 8);
1350 sk_write(s, FWhost, strlen(FWhost));
1353 sprintf(buf, " %d\n", FWport);
1354 sk_write(s, buf, strlen(buf));
1362 * Handle the key exchange and user authentication phases.
1364 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1367 unsigned char *rsabuf, *keystr1, *keystr2;
1368 unsigned char cookie[8];
1369 struct RSAKey servkey, hostkey;
1370 struct MD5Context md5c;
1371 static unsigned long supported_ciphers_mask, supported_auths_mask;
1372 static int tried_publickey;
1373 static unsigned char session_id[16];
1375 static char username[100];
1379 if (!ispkt) crWaitUntil(ispkt);
1381 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1382 bombout(("Public key packet not received"));
1386 logevent("Received public keys");
1388 memcpy(cookie, pktin.body, 8);
1390 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1391 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1394 * Log the host key fingerprint.
1398 logevent("Host key fingerprint is:");
1399 strcpy(logmsg, " ");
1400 hostkey.comment = NULL;
1401 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1406 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1407 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1410 MD5Update(&md5c, keystr2, hostkey.bytes);
1411 MD5Update(&md5c, keystr1, servkey.bytes);
1412 MD5Update(&md5c, pktin.body, 8);
1413 MD5Final(session_id, &md5c);
1415 for (i=0; i<32; i++)
1416 session_key[i] = random_byte();
1418 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1420 rsabuf = smalloc(len);
1422 fatalbox("Out of memory");
1425 * Verify the host key.
1429 * First format the key into a string.
1431 int len = rsastr_len(&hostkey);
1432 char fingerprint[100];
1433 char *keystr = smalloc(len);
1435 fatalbox("Out of memory");
1436 rsastr_fmt(keystr, &hostkey);
1437 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1438 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1442 for (i=0; i<32; i++) {
1443 rsabuf[i] = session_key[i];
1445 rsabuf[i] ^= session_id[i];
1448 if (hostkey.bytes > servkey.bytes) {
1449 rsaencrypt(rsabuf, 32, &servkey);
1450 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1452 rsaencrypt(rsabuf, 32, &hostkey);
1453 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1456 logevent("Encrypted session key");
1458 switch (cfg.cipher) {
1459 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break;
1460 case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break;
1461 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break;
1463 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1464 cipher_type = SSH_CIPHER_3DES;
1467 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1468 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
1469 cipher_type = SSH_CIPHER_3DES;
1471 switch (cipher_type) {
1472 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1473 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1474 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1477 send_packet(SSH1_CMSG_SESSION_KEY,
1478 PKT_CHAR, cipher_type,
1479 PKT_DATA, cookie, 8,
1480 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1481 PKT_DATA, rsabuf, len,
1485 logevent("Trying to enable encryption...");
1489 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1490 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1492 cipher->sesskey(session_key);
1496 if (pktin.type != SSH1_SMSG_SUCCESS) {
1497 bombout(("Encryption not successfully enabled"));
1501 logevent("Successfully started encryption");
1507 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1508 c_write_str("login as: ");
1511 crWaitUntil(!ispkt);
1512 while (inlen--) switch (c = *in++) {
1519 c_write_str("\b \b");
1525 c_write_str("\b \b");
1534 if (((c >= ' ' && c <= '~') ||
1535 ((unsigned char)c >= 160)) && pos < 40) {
1536 username[pos++] = c;
1542 c_write_str("\r\n");
1543 username[strcspn(username, "\n\r")] = '\0';
1545 strncpy(username, cfg.username, 99);
1546 username[99] = '\0';
1549 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1551 char userlog[22+sizeof(username)];
1552 sprintf(userlog, "Sent username \"%s\"", username);
1554 if (flags & FLAG_INTERACTIVE &&
1555 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1556 strcat(userlog, "\r\n");
1557 c_write_str(userlog);
1564 tried_publickey = 0;
1566 while (pktin.type == SSH1_SMSG_FAILURE) {
1567 static char password[100];
1568 static char prompt[200];
1571 static int pwpkt_type;
1573 * Show password prompt, having first obtained it via a TIS
1574 * or CryptoCard exchange if we're doing TIS or CryptoCard
1577 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1578 if (agent_exists()) {
1580 * Attempt RSA authentication using Pageant.
1582 static unsigned char request[5], *response, *p;
1583 static int responselen;
1584 static int i, nkeys;
1585 static int authed = FALSE;
1588 logevent("Pageant is running. Requesting keys.");
1590 /* Request the keys held by the agent. */
1591 PUT_32BIT(request, 1);
1592 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1593 agent_query(request, 5, &r, &responselen);
1594 response = (unsigned char *)r;
1597 nkeys = GET_32BIT(p); p += 4;
1598 { char buf[64]; sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1600 for (i = 0; i < nkeys; i++) {
1601 static struct RSAKey key;
1602 static Bignum challenge;
1603 static char *commentp;
1604 static int commentlen;
1606 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1609 p += ssh1_read_bignum(p, &key.exponent);
1610 p += ssh1_read_bignum(p, &key.modulus);
1611 commentlen = GET_32BIT(p); p += 4;
1612 commentp = p; p += commentlen;
1613 send_packet(SSH1_CMSG_AUTH_RSA,
1614 PKT_BIGNUM, key.modulus, PKT_END);
1616 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1617 logevent("Key refused");
1620 logevent("Received RSA challenge");
1621 ssh1_read_bignum(pktin.body, &challenge);
1623 char *agentreq, *q, *ret;
1625 len = 1 + 4; /* message type, bit count */
1626 len += ssh1_bignum_length(key.exponent);
1627 len += ssh1_bignum_length(key.modulus);
1628 len += ssh1_bignum_length(challenge);
1629 len += 16; /* session id */
1630 len += 4; /* response format */
1631 agentreq = smalloc(4 + len);
1632 PUT_32BIT(agentreq, len);
1634 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1635 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1637 q += ssh1_write_bignum(q, key.exponent);
1638 q += ssh1_write_bignum(q, key.modulus);
1639 q += ssh1_write_bignum(q, challenge);
1640 memcpy(q, session_id, 16); q += 16;
1641 PUT_32BIT(q, 1); /* response format */
1642 agent_query(agentreq, len+4, &ret, &retlen);
1645 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1646 logevent("Sending Pageant's response");
1647 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1648 PKT_DATA, ret+5, 16, PKT_END);
1651 if (pktin.type == SSH1_SMSG_SUCCESS) {
1652 logevent("Pageant's response accepted");
1653 if (flags & FLAG_VERBOSE) {
1654 c_write_str("Authenticated using RSA key \"");
1655 c_write(commentp, commentlen);
1656 c_write_str("\" from agent\r\n");
1660 logevent("Pageant's response not accepted");
1662 logevent("Pageant failed to answer challenge");
1666 logevent("No reply received from Pageant");
1669 freebn(key.exponent);
1670 freebn(key.modulus);
1679 if (*cfg.keyfile && !tried_publickey)
1680 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1682 if (pktin.type == SSH1_SMSG_FAILURE &&
1684 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1685 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1686 logevent("Requested TIS authentication");
1687 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1689 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1690 logevent("TIS authentication declined");
1691 if (flags & FLAG_INTERACTIVE)
1692 c_write_str("TIS authentication refused.\r\n");
1694 int challengelen = ((pktin.body[0] << 24) |
1695 (pktin.body[1] << 16) |
1696 (pktin.body[2] << 8) |
1698 logevent("Received TIS challenge");
1699 if (challengelen > sizeof(prompt)-1)
1700 challengelen = sizeof(prompt)-1; /* prevent overrun */
1701 memcpy(prompt, pktin.body+4, challengelen);
1702 prompt[challengelen] = '\0';
1705 if (pktin.type == SSH1_SMSG_FAILURE &&
1707 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1708 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1709 logevent("Requested CryptoCard authentication");
1710 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1712 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1713 logevent("CryptoCard authentication declined");
1714 c_write_str("CryptoCard authentication refused.\r\n");
1716 int challengelen = ((pktin.body[0] << 24) |
1717 (pktin.body[1] << 16) |
1718 (pktin.body[2] << 8) |
1720 logevent("Received CryptoCard challenge");
1721 if (challengelen > sizeof(prompt)-1)
1722 challengelen = sizeof(prompt)-1; /* prevent overrun */
1723 memcpy(prompt, pktin.body+4, challengelen);
1724 strncpy(prompt + challengelen, "\r\nResponse : ",
1725 sizeof(prompt)-challengelen);
1726 prompt[sizeof(prompt)-1] = '\0';
1729 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1730 sprintf(prompt, "%.90s@%.90s's password: ",
1731 username, savedhost);
1733 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1734 char *comment = NULL;
1735 if (flags & FLAG_VERBOSE)
1736 c_write_str("Trying public key authentication.\r\n");
1737 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1738 if (flags & FLAG_VERBOSE)
1739 c_write_str("No passphrase required.\r\n");
1742 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1746 if (ssh_get_password) {
1747 if (!ssh_get_password(prompt, password, sizeof(password))) {
1749 * get_password failed to get a password (for
1750 * example because one was supplied on the command
1751 * line which has already failed to work).
1754 logevent("No more passwords to try");
1755 ssh_state = SSH_STATE_CLOSED;
1759 c_write_str(prompt);
1763 crWaitUntil(!ispkt);
1764 while (inlen--) switch (c = *in++) {
1781 if (((c >= ' ' && c <= '~') ||
1782 ((unsigned char)c >= 160)) && pos < sizeof(password))
1783 password[pos++] = c;
1787 c_write_str("\r\n");
1791 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1793 * Try public key authentication with the specified
1796 static struct RSAKey pubkey;
1797 static Bignum challenge, response;
1799 static unsigned char buffer[32];
1801 tried_publickey = 1;
1802 i = loadrsakey(cfg.keyfile, &pubkey, password);
1804 c_write_str("Couldn't load public key from ");
1805 c_write_str(cfg.keyfile);
1806 c_write_str(".\r\n");
1807 continue; /* go and try password */
1810 c_write_str("Wrong passphrase.\r\n");
1811 tried_publickey = 0;
1812 continue; /* try again */
1816 * Send a public key attempt.
1818 send_packet(SSH1_CMSG_AUTH_RSA,
1819 PKT_BIGNUM, pubkey.modulus, PKT_END);
1822 if (pktin.type == SSH1_SMSG_FAILURE) {
1823 c_write_str("Server refused our public key.\r\n");
1824 continue; /* go and try password */
1826 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1827 bombout(("Bizarre response to offer of public key"));
1830 ssh1_read_bignum(pktin.body, &challenge);
1831 response = rsadecrypt(challenge, &pubkey);
1832 freebn(pubkey.private_exponent); /* burn the evidence */
1834 for (i = 0; i < 32; i++) {
1835 buffer[i] = bignum_byte(response, 31-i);
1839 MD5Update(&md5c, buffer, 32);
1840 MD5Update(&md5c, session_id, 16);
1841 MD5Final(buffer, &md5c);
1843 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1844 PKT_DATA, buffer, 16, PKT_END);
1847 if (pktin.type == SSH1_SMSG_FAILURE) {
1848 if (flags & FLAG_VERBOSE)
1849 c_write_str("Failed to authenticate with our public key.\r\n");
1850 continue; /* go and try password */
1851 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1852 bombout(("Bizarre response to RSA authentication response"));
1856 break; /* we're through! */
1858 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1860 * Defence against traffic analysis: we send a
1861 * whole bunch of packets containing strings of
1862 * different lengths. One of these strings is the
1863 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
1864 * The others are all random data in
1865 * SSH1_MSG_IGNORE packets. This way a passive
1866 * listener can't tell which is the password, and
1867 * hence can't deduce the password length.
1869 * Anybody with a password length greater than 16
1870 * bytes is going to have enough entropy in their
1871 * password that a listener won't find it _that_
1872 * much help to know how long it is. So what we'll
1875 * - if password length < 16, we send 15 packets
1876 * containing string lengths 1 through 15
1878 * - otherwise, we let N be the nearest multiple
1879 * of 8 below the password length, and send 8
1880 * packets containing string lengths N through
1881 * N+7. This won't obscure the order of
1882 * magnitude of the password length, but it will
1883 * introduce a bit of extra uncertainty.
1885 * A few servers (the old 1.2.18 through 1.2.22)
1886 * can't deal with SSH1_MSG_IGNORE. For these
1887 * servers, we need an alternative defence. We make
1888 * use of the fact that the password is interpreted
1889 * as a C string: so we can append a NUL, then some
1892 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
1897 len = strlen(password);
1898 if (len < sizeof(string)) {
1900 strcpy(string, password);
1901 len++; /* cover the zero byte */
1902 while (len < sizeof(string)) {
1903 string[len++] = (char)random_byte();
1908 send_packet(pwpkt_type, PKT_INT, len,
1909 PKT_DATA, s, len, PKT_END);
1911 int bottom, top, pwlen, i;
1914 pwlen = strlen(password);
1919 bottom = pwlen &~ 7;
1923 assert(pwlen >= bottom && pwlen <= top);
1925 randomstr = smalloc(top+1);
1927 for (i = bottom; i <= top; i++) {
1929 defer_packet(pwpkt_type, PKT_STR, password, PKT_END);
1931 for (j = 0; j < i; j++) {
1933 randomstr[j] = random_byte();
1934 } while (randomstr[j] == '\0');
1936 randomstr[i] = '\0';
1937 defer_packet(SSH1_MSG_IGNORE,
1938 PKT_STR, randomstr, PKT_END);
1941 ssh_pkt_defersend();
1944 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1947 logevent("Sent password");
1948 memset(password, 0, strlen(password));
1950 if (pktin.type == SSH1_SMSG_FAILURE) {
1951 if (flags & FLAG_VERBOSE)
1952 c_write_str("Access denied\r\n");
1953 logevent("Authentication refused");
1954 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1955 logevent("Received disconnect request");
1956 ssh_state = SSH_STATE_CLOSED;
1958 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1959 bombout(("Strange packet received, type %d", pktin.type));
1964 logevent("Authentication successful");
1969 void sshfwd_close(struct ssh_channel *c) {
1971 if (ssh_version == 1) {
1972 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1974 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1975 ssh2_pkt_adduint32(c->remoteid);
1979 if (c->type == CHAN_X11) {
1981 logevent("X11 connection terminated");
1986 void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
1987 if (ssh_version == 1) {
1988 send_packet(SSH1_MSG_CHANNEL_DATA,
1989 PKT_INT, c->remoteid,
1994 ssh2_add_channel_data(c, buf, len);
1999 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
2004 while (!do_ssh1_login(in, inlen, ispkt)) {
2007 if (ssh_state == SSH_STATE_CLOSED)
2010 if (cfg.agentfwd && agent_exists()) {
2011 logevent("Requesting agent forwarding");
2012 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2013 do { crReturnV; } while (!ispkt);
2014 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2015 bombout(("Protocol confusion"));
2017 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2018 logevent("Agent forwarding refused");
2020 logevent("Agent forwarding enabled");
2021 ssh_agentfwd_enabled = TRUE;
2025 if (cfg.x11_forward) {
2026 char proto[20], data[64];
2027 logevent("Requesting X11 forwarding");
2028 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2029 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2030 PKT_STR, proto, PKT_STR, data,
2033 do { crReturnV; } while (!ispkt);
2034 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2035 bombout(("Protocol confusion"));
2037 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2038 logevent("X11 forwarding refused");
2040 logevent("X11 forwarding enabled");
2041 ssh_X11_fwd_enabled = TRUE;
2046 send_packet(SSH1_CMSG_REQUEST_PTY,
2047 PKT_STR, cfg.termtype,
2048 PKT_INT, rows, PKT_INT, cols,
2049 PKT_INT, 0, PKT_INT, 0,
2052 ssh_state = SSH_STATE_INTERMED;
2053 do { crReturnV; } while (!ispkt);
2054 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2055 bombout(("Protocol confusion"));
2057 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2058 c_write_str("Server refused to allocate pty\r\n");
2059 ssh_editing = ssh_echoing = 1;
2061 logevent("Allocated pty");
2063 ssh_editing = ssh_echoing = 1;
2066 if (cfg.compression) {
2067 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
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 compress\r\n");
2075 logevent("Started compression");
2076 ssh1_compressing = TRUE;
2077 zlib_compress_init();
2078 zlib_decompress_init();
2081 if (*cfg.remote_cmd)
2082 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
2084 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2085 logevent("Started session");
2087 ssh_state = SSH_STATE_SESSION;
2091 ssh_special(TS_EOF);
2093 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2095 ssh_channels = newtree234(ssh_channelcmp);
2099 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2100 pktin.type == SSH1_SMSG_STDERR_DATA) {
2101 long len = GET_32BIT(pktin.body);
2102 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2104 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2105 ssh_state = SSH_STATE_CLOSED;
2106 logevent("Received disconnect request");
2108 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2109 /* Remote side is trying to open a channel to talk to our
2110 * X-Server. Give them back a local channel number. */
2112 struct ssh_channel *c, *d;
2115 logevent("Received X11 connect request");
2116 /* Refuse if X11 forwarding is disabled. */
2117 if (!ssh_X11_fwd_enabled) {
2118 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2119 PKT_INT, GET_32BIT(pktin.body),
2121 logevent("Rejected X11 connect request");
2123 c = smalloc(sizeof(struct ssh_channel));
2125 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
2126 logevent("opening X11 forward connection failed");
2128 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2129 PKT_INT, GET_32BIT(pktin.body),
2132 logevent("opening X11 forward connection succeeded");
2133 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
2135 break; /* found a free number */
2138 c->remoteid = GET_32BIT(pktin.body);
2141 c->type = CHAN_X11; /* identify channel type */
2142 add234(ssh_channels, c);
2143 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2144 PKT_INT, c->remoteid, PKT_INT, c->localid,
2146 logevent("Opened X11 forward channel");
2149 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2150 /* Remote side is trying to open a channel to talk to our
2151 * agent. Give them back a local channel number. */
2153 struct ssh_channel *c;
2156 /* Refuse if agent forwarding is disabled. */
2157 if (!ssh_agentfwd_enabled) {
2158 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2159 PKT_INT, GET_32BIT(pktin.body),
2163 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
2165 break; /* found a free number */
2168 c = smalloc(sizeof(struct ssh_channel));
2169 c->remoteid = GET_32BIT(pktin.body);
2172 c->type = CHAN_AGENT; /* identify channel type */
2173 c->u.a.lensofar = 0;
2174 add234(ssh_channels, c);
2175 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2176 PKT_INT, c->remoteid, PKT_INT, c->localid,
2179 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2180 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2181 /* Remote side closes a channel. */
2182 unsigned i = GET_32BIT(pktin.body);
2183 struct ssh_channel *c;
2184 c = find234(ssh_channels, &i, ssh_channelfind);
2187 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2188 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
2189 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2190 logevent("X11 connection closed");
2191 assert(c->u.x11.s != NULL);
2192 x11_close(c->u.x11.s);
2195 c->closes |= closetype;
2196 if (c->closes == 3) {
2197 del234(ssh_channels, c);
2201 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2202 /* Data sent down one of our channels. */
2203 int i = GET_32BIT(pktin.body);
2204 int len = GET_32BIT(pktin.body+4);
2205 unsigned char *p = pktin.body+8;
2206 struct ssh_channel *c;
2207 c = find234(ssh_channels, &i, ssh_channelfind);
2211 x11_send(c->u.x11.s, p, len);
2214 /* Data for an agent message. Buffer it. */
2216 if (c->u.a.lensofar < 4) {
2217 int l = min(4 - c->u.a.lensofar, len);
2218 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2219 p += l; len -= l; c->u.a.lensofar += l;
2221 if (c->u.a.lensofar == 4) {
2222 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
2223 c->u.a.message = smalloc(c->u.a.totallen);
2224 memcpy(c->u.a.message, c->u.a.msglen, 4);
2226 if (c->u.a.lensofar >= 4 && len > 0) {
2227 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2228 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2229 p += l; len -= l; c->u.a.lensofar += l;
2231 if (c->u.a.lensofar == c->u.a.totallen) {
2232 void *reply, *sentreply;
2234 agent_query(c->u.a.message, c->u.a.totallen,
2239 /* Fake SSH_AGENT_FAILURE. */
2240 sentreply = "\0\0\0\1\5";
2243 send_packet(SSH1_MSG_CHANNEL_DATA,
2244 PKT_INT, c->remoteid,
2246 PKT_DATA, sentreply, replylen,
2250 sfree(c->u.a.message);
2251 c->u.a.lensofar = 0;
2257 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2258 /* may be from EXEC_SHELL on some servers */
2259 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2260 /* may be from EXEC_SHELL on some servers
2261 * if no pty is available or in other odd cases. Ignore */
2262 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2263 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2265 bombout(("Strange packet received: type %d", pktin.type));
2270 int len = min(inlen, 512);
2271 send_packet(SSH1_CMSG_STDIN_DATA,
2272 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2283 * Utility routine for decoding comma-separated strings in KEXINIT.
2285 static int in_commasep_string(char *needle, char *haystack, int haylen) {
2286 int needlen = strlen(needle);
2289 * Is it at the start of the string?
2291 if (haylen >= needlen && /* haystack is long enough */
2292 !memcmp(needle, haystack, needlen) && /* initial match */
2293 (haylen == needlen || haystack[needlen] == ',')
2294 /* either , or EOS follows */
2298 * If not, search for the next comma and resume after that.
2299 * If no comma found, terminate.
2301 while (haylen > 0 && *haystack != ',')
2302 haylen--, haystack++;
2305 haylen--, haystack++; /* skip over comma itself */
2310 * SSH2 key creation method.
2312 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
2314 /* First 20 bytes. */
2317 SHA_Bytes(&s, H, 20);
2318 SHA_Bytes(&s, &chr, 1);
2319 SHA_Bytes(&s, sessid, 20);
2320 SHA_Final(&s, keyspace);
2321 /* Next 20 bytes. */
2324 SHA_Bytes(&s, H, 20);
2325 SHA_Bytes(&s, keyspace, 20);
2326 SHA_Final(&s, keyspace+20);
2330 * Handle the SSH2 transport layer.
2332 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2334 static int i, j, len, nbits;
2336 static Bignum p, g, e, f, K;
2337 static int kex_init_value, kex_reply_value;
2338 static const struct ssh_mac **maclist;
2340 static const struct ssh2_cipher *cscipher_tobe = NULL;
2341 static const struct ssh2_cipher *sccipher_tobe = NULL;
2342 static const struct ssh_mac *csmac_tobe = NULL;
2343 static const struct ssh_mac *scmac_tobe = NULL;
2344 static const struct ssh_compress *cscomp_tobe = NULL;
2345 static const struct ssh_compress *sccomp_tobe = NULL;
2346 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2347 static int hostkeylen, siglen;
2348 static void *hkey; /* actual host key */
2349 static unsigned char exchange_hash[20];
2350 static unsigned char keyspace[40];
2351 static const struct ssh2_ciphers *preferred_cipher;
2352 static const struct ssh_compress *preferred_comp;
2353 static int first_kex;
2360 * Set up the preferred cipher and compression.
2362 if (cfg.cipher == CIPHER_BLOWFISH) {
2363 preferred_cipher = &ssh2_blowfish;
2364 } else if (cfg.cipher == CIPHER_DES) {
2365 logevent("Single DES not supported in SSH2; using 3DES");
2366 preferred_cipher = &ssh2_3des;
2367 } else if (cfg.cipher == CIPHER_3DES) {
2368 preferred_cipher = &ssh2_3des;
2369 } else if (cfg.cipher == CIPHER_AES) {
2370 preferred_cipher = &ssh2_aes;
2372 /* Shouldn't happen, but we do want to initialise to _something_. */
2373 preferred_cipher = &ssh2_3des;
2375 if (cfg.compression)
2376 preferred_comp = &ssh_zlib;
2378 preferred_comp = &ssh_comp_none;
2381 * Be prepared to work around the buggy MAC problem.
2383 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
2384 maclist = buggymacs, nmacs = lenof(buggymacs);
2386 maclist = macs, nmacs = lenof(macs);
2390 * Construct and send our key exchange packet.
2392 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2393 for (i = 0; i < 16; i++)
2394 ssh2_pkt_addbyte((unsigned char)random_byte());
2395 /* List key exchange algorithms. */
2396 ssh2_pkt_addstring_start();
2397 for (i = 0; i < lenof(kex_algs); i++) {
2398 ssh2_pkt_addstring_str(kex_algs[i]->name);
2399 if (i < lenof(kex_algs)-1)
2400 ssh2_pkt_addstring_str(",");
2402 /* List server host key algorithms. */
2403 ssh2_pkt_addstring_start();
2404 for (i = 0; i < lenof(hostkey_algs); i++) {
2405 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2406 if (i < lenof(hostkey_algs)-1)
2407 ssh2_pkt_addstring_str(",");
2409 /* List client->server encryption algorithms. */
2410 ssh2_pkt_addstring_start();
2411 for (i = 0; i < lenof(ciphers)+1; i++) {
2412 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2413 for (j = 0; j < c->nciphers; j++) {
2414 ssh2_pkt_addstring_str(c->list[j]->name);
2415 if (i < lenof(ciphers) || j < c->nciphers-1)
2416 ssh2_pkt_addstring_str(",");
2419 /* List server->client encryption algorithms. */
2420 ssh2_pkt_addstring_start();
2421 for (i = 0; i < lenof(ciphers)+1; i++) {
2422 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2423 for (j = 0; j < c->nciphers; j++) {
2424 ssh2_pkt_addstring_str(c->list[j]->name);
2425 if (i < lenof(ciphers) || j < c->nciphers-1)
2426 ssh2_pkt_addstring_str(",");
2429 /* List client->server MAC algorithms. */
2430 ssh2_pkt_addstring_start();
2431 for (i = 0; i < nmacs; i++) {
2432 ssh2_pkt_addstring_str(maclist[i]->name);
2434 ssh2_pkt_addstring_str(",");
2436 /* List server->client MAC algorithms. */
2437 ssh2_pkt_addstring_start();
2438 for (i = 0; i < nmacs; i++) {
2439 ssh2_pkt_addstring_str(maclist[i]->name);
2441 ssh2_pkt_addstring_str(",");
2443 /* List client->server compression algorithms. */
2444 ssh2_pkt_addstring_start();
2445 for (i = 0; i < lenof(compressions)+1; i++) {
2446 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2447 ssh2_pkt_addstring_str(c->name);
2448 if (i < lenof(compressions))
2449 ssh2_pkt_addstring_str(",");
2451 /* List server->client compression algorithms. */
2452 ssh2_pkt_addstring_start();
2453 for (i = 0; i < lenof(compressions)+1; i++) {
2454 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2455 ssh2_pkt_addstring_str(c->name);
2456 if (i < lenof(compressions))
2457 ssh2_pkt_addstring_str(",");
2459 /* List client->server languages. Empty list. */
2460 ssh2_pkt_addstring_start();
2461 /* List server->client languages. Empty list. */
2462 ssh2_pkt_addstring_start();
2463 /* First KEX packet does _not_ follow, because we're not that brave. */
2464 ssh2_pkt_addbool(FALSE);
2466 ssh2_pkt_adduint32(0);
2468 exhash = exhashbase;
2469 sha_string(&exhash, pktout.data+5, pktout.length-5);
2473 if (!ispkt) crWaitUntil(ispkt);
2474 sha_string(&exhash, pktin.data+5, pktin.length-5);
2477 * Now examine the other side's KEXINIT to see what we're up
2480 if (pktin.type != SSH2_MSG_KEXINIT) {
2481 bombout(("expected key exchange packet from server"));
2484 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2485 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2486 pktin.savedpos += 16; /* skip garbage cookie */
2487 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2488 for (i = 0; i < lenof(kex_algs); i++) {
2489 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2494 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2495 for (i = 0; i < lenof(hostkey_algs); i++) {
2496 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2497 hostkey = hostkey_algs[i];
2501 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2502 for (i = 0; i < lenof(ciphers)+1; i++) {
2503 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2504 for (j = 0; j < c->nciphers; j++) {
2505 if (in_commasep_string(c->list[j]->name, str, len)) {
2506 cscipher_tobe = c->list[j];
2513 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2514 for (i = 0; i < lenof(ciphers)+1; i++) {
2515 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2516 for (j = 0; j < c->nciphers; j++) {
2517 if (in_commasep_string(c->list[j]->name, str, len)) {
2518 sccipher_tobe = c->list[j];
2525 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2526 for (i = 0; i < nmacs; i++) {
2527 if (in_commasep_string(maclist[i]->name, str, len)) {
2528 csmac_tobe = maclist[i];
2532 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2533 for (i = 0; i < nmacs; i++) {
2534 if (in_commasep_string(maclist[i]->name, str, len)) {
2535 scmac_tobe = maclist[i];
2539 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2540 for (i = 0; i < lenof(compressions)+1; i++) {
2541 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2542 if (in_commasep_string(c->name, str, len)) {
2547 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2548 for (i = 0; i < lenof(compressions)+1; i++) {
2549 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2550 if (in_commasep_string(c->name, str, len)) {
2557 * If we're doing Diffie-Hellman group exchange, start by
2558 * requesting a group.
2560 if (kex == &ssh_diffiehellman_gex) {
2563 logevent("Doing Diffie-Hellman group exchange");
2565 * Work out number of bits. We start with the maximum key
2566 * length of either cipher...
2568 csbits = cscipher_tobe->keylen;
2569 scbits = sccipher_tobe->keylen;
2570 nbits = (csbits > scbits ? csbits : scbits);
2571 /* The keys only have 160-bit entropy, since they're based on
2572 * a SHA-1 hash. So cap the key size at 160 bits. */
2573 if (nbits > 160) nbits = 160;
2575 * ... and then work out how big a DH group we will need to
2576 * allow that much data.
2578 nbits = 512 << ((nbits-1) / 64);
2579 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2580 ssh2_pkt_adduint32(nbits);
2584 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2585 bombout(("expected key exchange group packet from server"));
2588 p = ssh2_pkt_getmp();
2589 g = ssh2_pkt_getmp();
2590 dh_setup_group(p, g);
2591 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2592 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2595 kex_init_value = SSH2_MSG_KEXDH_INIT;
2596 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
2599 logevent("Doing Diffie-Hellman key exchange");
2601 * Now generate and send e for Diffie-Hellman.
2604 ssh2_pkt_init(kex_init_value);
2609 if (pktin.type != kex_reply_value) {
2610 bombout(("expected key exchange reply packet from server"));
2613 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2614 f = ssh2_pkt_getmp();
2615 ssh2_pkt_getstring(&sigdata, &siglen);
2619 sha_string(&exhash, hostkeydata, hostkeylen);
2620 if (kex == &ssh_diffiehellman_gex) {
2621 sha_uint32(&exhash, nbits);
2622 sha_mpint(&exhash, p);
2623 sha_mpint(&exhash, g);
2625 sha_mpint(&exhash, e);
2626 sha_mpint(&exhash, f);
2627 sha_mpint(&exhash, K);
2628 SHA_Final(&exhash, exchange_hash);
2633 debug(("Exchange hash is:\r\n"));
2634 for (i = 0; i < 20; i++)
2635 debug((" %02x", exchange_hash[i]));
2639 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2640 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2641 bombout(("Server failed host key check"));
2646 * Expect SSH2_MSG_NEWKEYS from server.
2649 if (pktin.type != SSH2_MSG_NEWKEYS) {
2650 bombout(("expected new-keys packet from server"));
2655 * Authenticate remote host: verify host key. (We've already
2656 * checked the signature of the exchange hash.)
2658 keystr = hostkey->fmtkey(hkey);
2659 fingerprint = hostkey->fingerprint(hkey);
2660 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2661 keystr, fingerprint);
2662 if (first_kex) { /* don't bother logging this in rekeys */
2663 logevent("Host key fingerprint is:");
2664 logevent(fingerprint);
2668 hostkey->freekey(hkey);
2671 * Send SSH2_MSG_NEWKEYS.
2673 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2677 * Create and initialise session keys.
2679 cscipher = cscipher_tobe;
2680 sccipher = sccipher_tobe;
2683 cscomp = cscomp_tobe;
2684 sccomp = sccomp_tobe;
2685 cscomp->compress_init();
2686 sccomp->decompress_init();
2688 * Set IVs after keys. Here we use the exchange hash from the
2689 * _first_ key exchange.
2692 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
2693 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
2694 cscipher->setcskey(keyspace);
2695 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
2696 sccipher->setsckey(keyspace);
2697 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
2698 cscipher->setcsiv(keyspace);
2699 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
2700 sccipher->setsciv(keyspace);
2701 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
2702 csmac->setcskey(keyspace);
2703 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
2704 scmac->setsckey(keyspace);
2707 * If this is the first key exchange phase, we must pass the
2708 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2709 * wants to see it but because it will need time to initialise
2710 * itself before it sees an actual packet. In subsequent key
2711 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2712 * it would only confuse the layer above.
2720 * Now we're encrypting. Begin returning 1 to the protocol main
2721 * function so that other things can run on top of the
2722 * transport. If we ever see a KEXINIT, we must go back to the
2725 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
2728 logevent("Server initiated key re-exchange");
2729 goto begin_key_exchange;
2735 * Add data to an SSH2 channel output buffer.
2737 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2738 if (c->v2.outbufsize <
2739 c->v2.outbuflen + len) {
2741 c->v2.outbuflen + len + 1024;
2742 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2745 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2747 c->v2.outbuflen += len;
2751 * Attempt to send data on an SSH2 channel.
2753 static void ssh2_try_send(struct ssh_channel *c) {
2754 while (c->v2.remwindow > 0 &&
2755 c->v2.outbuflen > 0) {
2756 unsigned len = c->v2.remwindow;
2757 if (len > c->v2.outbuflen)
2758 len = c->v2.outbuflen;
2759 if (len > c->v2.remmaxpkt)
2760 len = c->v2.remmaxpkt;
2761 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2762 ssh2_pkt_adduint32(c->remoteid);
2763 ssh2_pkt_addstring_start();
2764 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2766 c->v2.outbuflen -= len;
2767 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2769 c->v2.remwindow -= len;
2774 * Handle the SSH2 userauth and connection layers.
2776 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2778 static unsigned long remote_winsize;
2779 static unsigned long remote_maxpkt;
2781 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD
2785 AUTH_TYPE_PUBLICKEY,
2786 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
2787 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
2790 static int gotit, need_pw, can_pubkey, can_passwd;
2791 static int tried_pubkey_config, tried_agent;
2792 static int we_are_in;
2793 static char username[100];
2794 static char pwprompt[200];
2795 static char password[100];
2800 * Request userauth protocol, and await a response to it.
2802 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2803 ssh2_pkt_addstring("ssh-userauth");
2805 crWaitUntilV(ispkt);
2806 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2807 bombout(("Server refused user authentication protocol"));
2812 * We repeat this whole loop, including the username prompt,
2813 * until we manage a successful authentication. If the user
2814 * types the wrong _password_, they are sent back to the
2815 * beginning to try another username. (If they specify a
2816 * username in the config, they are never asked, even if they
2817 * do give a wrong password.)
2819 * I think this best serves the needs of
2821 * - the people who have no configuration, no keys, and just
2822 * want to try repeated (username,password) pairs until they
2823 * type both correctly
2825 * - people who have keys and configuration but occasionally
2826 * need to fall back to passwords
2828 * - people with a key held in Pageant, who might not have
2829 * logged in to a particular machine before; so they want to
2830 * type a username, and then _either_ their key will be
2831 * accepted, _or_ they will type a password. If they mistype
2832 * the username they will want to be able to get back and
2843 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2844 c_write_str("login as: ");
2847 crWaitUntilV(!ispkt);
2848 while (inlen--) switch (c = *in++) {
2855 c_write_str("\b \b");
2861 c_write_str("\b \b");
2870 if (((c >= ' ' && c <= '~') ||
2871 ((unsigned char)c >= 160)) && pos < 40) {
2872 username[pos++] = c;
2878 c_write_str("\r\n");
2879 username[strcspn(username, "\n\r")] = '\0';
2882 strncpy(username, cfg.username, 99);
2883 username[99] = '\0';
2884 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2885 sprintf(stuff, "Using username \"%s\".\r\n", username);
2891 * Send an authentication request using method "none": (a)
2892 * just in case it succeeds, and (b) so that we know what
2893 * authentication methods we can usefully try next.
2895 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2896 ssh2_pkt_addstring(username);
2897 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2898 ssh2_pkt_addstring("none"); /* method */
2900 type = AUTH_TYPE_NONE;
2904 tried_pubkey_config = FALSE;
2905 tried_agent = FALSE;
2909 * Wait for the result of the last authentication request.
2912 crWaitUntilV(ispkt);
2913 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
2914 /* FIXME: should support this */
2915 crWaitUntilV(ispkt);
2917 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
2918 logevent("Access granted");
2923 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
2924 bombout(("Strange packet received during authentication: type %d",
2931 * OK, we're now sitting on a USERAUTH_FAILURE message, so
2932 * we can look at the string in it and know what we can
2933 * helpfully try next.
2938 ssh2_pkt_getstring(&methods, &methlen);
2939 if (!ssh2_pkt_getbool()) {
2941 * We have received an unequivocal Access
2942 * Denied. This can translate to a variety of
2945 * - if we'd just tried "none" authentication,
2946 * it's not worth printing anything at all
2948 * - if we'd just tried a public key _offer_,
2949 * the message should be "Server refused our
2950 * key" (or no message at all if the key
2951 * came from Pageant)
2953 * - if we'd just tried anything else, the
2954 * message really should be "Access denied".
2956 * Additionally, if we'd just tried password
2957 * authentication, we should break out of this
2958 * whole loop so as to go back to the username
2961 if (type == AUTH_TYPE_NONE) {
2963 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
2964 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
2965 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
2966 c_write_str("Server refused our key\r\n");
2967 logevent("Server refused public key");
2969 c_write_str("Access denied\r\n");
2970 logevent("Access denied");
2971 if (type == AUTH_TYPE_PASSWORD) {
2977 c_write_str("Further authentication required\r\n");
2978 logevent("Further authentication required");
2981 can_pubkey = in_commasep_string("publickey", methods, methlen);
2982 can_passwd = in_commasep_string("password", methods, methlen);
2987 if (!method && can_pubkey && agent_exists && !tried_agent) {
2989 * Attempt public-key authentication using Pageant.
2991 static unsigned char request[5], *response, *p;
2992 static int responselen;
2993 static int i, nkeys;
2994 static int authed = FALSE;
2999 logevent("Pageant is running. Requesting keys.");
3001 /* Request the keys held by the agent. */
3002 PUT_32BIT(request, 1);
3003 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3004 agent_query(request, 5, &r, &responselen);
3005 response = (unsigned char *)r;
3008 nkeys = GET_32BIT(p); p += 4;
3009 { char buf[64]; sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3011 for (i = 0; i < nkeys; i++) {
3012 static char *pkblob, *alg, *commentp;
3013 static int pklen, alglen, commentlen;
3014 static int siglen, retlen, len;
3015 static char *q, *agentreq, *ret;
3017 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
3019 pklen = GET_32BIT(p); p += 4;
3020 pkblob = p; p += pklen;
3021 alglen = GET_32BIT(pkblob);
3023 commentlen = GET_32BIT(p); p += 4;
3024 commentp = p; p += commentlen;
3025 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3026 ssh2_pkt_addstring(username);
3027 ssh2_pkt_addstring("ssh-connection");/* service requested */
3028 ssh2_pkt_addstring("publickey");/* method */
3029 ssh2_pkt_addbool(FALSE); /* no signature included */
3030 ssh2_pkt_addstring_start();
3031 ssh2_pkt_addstring_data(alg, alglen);
3032 ssh2_pkt_addstring_start();
3033 ssh2_pkt_addstring_data(pkblob, pklen);
3036 crWaitUntilV(ispkt);
3037 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3038 logevent("Key refused");
3042 c_write_str("Authenticating with public key \"");
3043 c_write(commentp, commentlen);
3044 c_write_str("\" from agent\r\n");
3047 * Server is willing to accept the key.
3048 * Construct a SIGN_REQUEST.
3050 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3051 ssh2_pkt_addstring(username);
3052 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3053 ssh2_pkt_addstring("publickey"); /* method */
3054 ssh2_pkt_addbool(TRUE);
3055 ssh2_pkt_addstring_start();
3056 ssh2_pkt_addstring_data(alg, alglen);
3057 ssh2_pkt_addstring_start();
3058 ssh2_pkt_addstring_data(pkblob, pklen);
3060 siglen = pktout.length - 5 + 4 + 20;
3061 len = 1; /* message type */
3062 len += 4 + pklen; /* key blob */
3063 len += 4 + siglen; /* data to sign */
3064 len += 4; /* flags */
3065 agentreq = smalloc(4 + len);
3066 PUT_32BIT(agentreq, len);
3068 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3069 PUT_32BIT(q, pklen); q += 4;
3070 memcpy(q, pkblob, pklen); q += pklen;
3071 PUT_32BIT(q, siglen); q += 4;
3072 /* Now the data to be signed... */
3073 PUT_32BIT(q, 20); q += 4;
3074 memcpy(q, ssh2_session_id, 20); q += 20;
3075 memcpy(q, pktout.data+5, pktout.length-5);
3076 q += pktout.length-5;
3077 /* And finally the (zero) flags word. */
3079 agent_query(agentreq, len+4, &ret, &retlen);
3082 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3083 logevent("Sending Pageant's response");
3084 ssh2_pkt_addstring_start();
3085 ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5));
3090 logevent("Pageant failed to answer challenge");
3100 if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) {
3101 unsigned char *pub_blob;
3102 char *algorithm, *comment;
3105 tried_pubkey_config = TRUE;
3108 * Try the public key supplied in the configuration.
3110 * First, offer the public blob to see if the server is
3111 * willing to accept it.
3113 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3116 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3117 ssh2_pkt_addstring(username);
3118 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3119 ssh2_pkt_addstring("publickey");/* method */
3120 ssh2_pkt_addbool(FALSE); /* no signature included */
3121 ssh2_pkt_addstring(algorithm);
3122 ssh2_pkt_addstring_start();
3123 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3125 logevent("Offered public key"); /* FIXME */
3127 crWaitUntilV(ispkt);
3128 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3130 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3131 continue; /* key refused; give up on it */
3134 logevent("Offer of public key accepted");
3136 * Actually attempt a serious authentication using
3139 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3140 sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment);
3145 c_write_str("Authenticating with public key \"");
3146 c_write_str(comment);
3147 c_write_str("\"\r\n");
3148 method = AUTH_PUBLICKEY_FILE;
3152 if (!method && can_passwd) {
3153 method = AUTH_PASSWORD;
3154 sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost);
3159 if (ssh_get_password) {
3160 if (!ssh_get_password(pwprompt, password, sizeof(password))) {
3162 * get_password failed to get a password (for
3163 * example because one was supplied on the command
3164 * line which has already failed to work).
3167 logevent("No more passwords to try");
3168 ssh_state = SSH_STATE_CLOSED;
3175 c_write_str(pwprompt);
3180 crWaitUntilV(!ispkt);
3181 while (inlen--) switch (c = *in++) {
3198 if (((c >= ' ' && c <= '~') ||
3199 ((unsigned char)c >= 160)) && pos < 40)
3200 password[pos++] = c;
3204 c_write_str("\r\n");
3208 if (method == AUTH_PUBLICKEY_FILE) {
3210 * We have our passphrase. Now try the actual authentication.
3212 struct ssh2_userkey *key;
3214 key = ssh2_load_userkey(cfg.keyfile, password);
3215 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3216 if (key == SSH2_WRONG_PASSPHRASE) {
3217 c_write_str("Wrong passphrase\r\n");
3218 tried_pubkey_config = FALSE;
3220 c_write_str("Unable to load private key\r\n");
3221 tried_pubkey_config = TRUE;
3223 /* Send a spurious AUTH_NONE to return to the top. */
3224 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3225 ssh2_pkt_addstring(username);
3226 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3227 ssh2_pkt_addstring("none"); /* method */
3229 type = AUTH_TYPE_NONE;
3231 unsigned char *blob, *sigdata;
3232 int blob_len, sigdata_len;
3235 * We have loaded the private key and the server
3236 * has announced that it's willing to accept it.
3237 * Hallelujah. Generate a signature and send it.
3239 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3240 ssh2_pkt_addstring(username);
3241 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3242 ssh2_pkt_addstring("publickey"); /* method */
3243 ssh2_pkt_addbool(TRUE);
3244 ssh2_pkt_addstring(key->alg->name);
3245 blob = key->alg->public_blob(key->data, &blob_len);
3246 ssh2_pkt_addstring_start();
3247 ssh2_pkt_addstring_data(blob, blob_len);
3251 * The data to be signed is:
3255 * followed by everything so far placed in the
3258 sigdata_len = pktout.length - 5 + 4 + 20;
3259 sigdata = smalloc(sigdata_len);
3260 PUT_32BIT(sigdata, 20);
3261 memcpy(sigdata+4, ssh2_session_id, 20);
3262 memcpy(sigdata+24, pktout.data+5, pktout.length-5);
3263 blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len);
3264 ssh2_pkt_addstring_start();
3265 ssh2_pkt_addstring_data(blob, blob_len);
3270 type = AUTH_TYPE_PUBLICKEY;
3272 } else if (method == AUTH_PASSWORD) {
3274 * We send the password packet lumped tightly together with
3275 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3276 * string long enough to make the total length of the two
3277 * packets constant. This should ensure that a passive
3278 * listener doing traffic analyis can't work out the length
3281 * For this to work, we need an assumption about the
3282 * maximum length of the password packet. I think 256 is
3283 * pretty conservative. Anyone using a password longer than
3284 * that probably doesn't have much to worry about from
3285 * people who find out how long their password is!
3287 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3288 ssh2_pkt_addstring(username);
3289 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3290 ssh2_pkt_addstring("password");
3291 ssh2_pkt_addbool(FALSE);
3292 ssh2_pkt_addstring(password);
3295 * We'll include a string that's an exact multiple of the
3296 * cipher block size. If the cipher is NULL for some
3297 * reason, we don't do this trick at all because we gain
3303 stringlen = (256 - deferred_len);
3304 stringlen += cscipher->blksize - 1;
3305 stringlen -= (stringlen % cscipher->blksize);
3308 * Temporarily disable actual compression,
3309 * so we can guarantee to get this string
3310 * exactly the length we want it. The
3311 * compression-disabling routine should
3312 * return an integer indicating how many
3313 * bytes we should adjust our string length
3316 stringlen -= cscomp->disable_compression();
3318 ssh2_pkt_init(SSH2_MSG_IGNORE);
3319 ssh2_pkt_addstring_start();
3320 for (i = 0; i < stringlen; i++) {
3321 char c = (char)random_byte();
3322 ssh2_pkt_addstring_data(&c, 1);
3326 ssh_pkt_defersend();
3327 logevent("Sent password");
3328 type = AUTH_TYPE_PASSWORD;
3330 c_write_str("No supported authentication methods left to try!\r\n");
3331 logevent("No supported authentications offered. Disconnecting");
3332 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3333 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3334 ssh2_pkt_addstring("No supported authentication methods available");
3335 ssh2_pkt_addstring("en"); /* language tag */
3337 ssh_state = SSH_STATE_CLOSED;
3341 } while (!we_are_in);
3344 * Now we're authenticated for the connection protocol. The
3345 * connection protocol will automatically have started at this
3346 * point; there's no need to send SERVICE_REQUEST.
3350 * So now create a channel with a session in it.
3352 mainchan = smalloc(sizeof(struct ssh_channel));
3353 mainchan->localid = 100; /* as good as any */
3354 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3355 ssh2_pkt_addstring("session");
3356 ssh2_pkt_adduint32(mainchan->localid);
3357 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3358 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3360 crWaitUntilV(ispkt);
3361 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
3362 bombout(("Server refused to open a session"));
3364 /* FIXME: error data comes back in FAILURE packet */
3366 if (ssh2_pkt_getuint32() != mainchan->localid) {
3367 bombout(("Server's channel confirmation cited wrong channel"));
3370 mainchan->remoteid = ssh2_pkt_getuint32();
3371 mainchan->type = CHAN_MAINSESSION;
3372 mainchan->closes = 0;
3373 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3374 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3375 mainchan->v2.outbuffer = NULL;
3376 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3377 ssh_channels = newtree234(ssh_channelcmp);
3378 add234(ssh_channels, mainchan);
3379 logevent("Opened channel for session");
3382 * Potentially enable X11 forwarding.
3384 if (cfg.x11_forward) {
3385 char proto[20], data[64];
3386 logevent("Requesting X11 forwarding");
3387 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3388 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3389 ssh2_pkt_adduint32(mainchan->remoteid);
3390 ssh2_pkt_addstring("x11-req");
3391 ssh2_pkt_addbool(1); /* want reply */
3392 ssh2_pkt_addbool(0); /* many connections */
3393 ssh2_pkt_addstring(proto);
3394 ssh2_pkt_addstring(data);
3395 ssh2_pkt_adduint32(0); /* screen number */
3399 crWaitUntilV(ispkt);
3400 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3401 unsigned i = ssh2_pkt_getuint32();
3402 struct ssh_channel *c;
3403 c = find234(ssh_channels, &i, ssh_channelfind);
3405 continue; /* nonexistent channel */
3406 c->v2.remwindow += ssh2_pkt_getuint32();
3408 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3410 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3411 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3412 bombout(("Server got confused by X11 forwarding request"));
3415 logevent("X11 forwarding refused");
3417 logevent("X11 forwarding enabled");
3418 ssh_X11_fwd_enabled = TRUE;
3423 * Potentially enable agent forwarding.
3425 if (cfg.agentfwd && agent_exists()) {
3426 char proto[20], data[64];
3427 logevent("Requesting OpenSSH-style agent forwarding");
3428 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3429 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3430 ssh2_pkt_adduint32(mainchan->remoteid);
3431 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3432 ssh2_pkt_addbool(1); /* want reply */
3436 crWaitUntilV(ispkt);
3437 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3438 unsigned i = ssh2_pkt_getuint32();
3439 struct ssh_channel *c;
3440 c = find234(ssh_channels, &i, ssh_channelfind);
3442 continue; /* nonexistent channel */
3443 c->v2.remwindow += ssh2_pkt_getuint32();
3445 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3447 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3448 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3449 bombout(("Server got confused by agent forwarding request"));
3452 logevent("Agent forwarding refused");
3454 logevent("Agent forwarding enabled");
3455 ssh_agentfwd_enabled = TRUE;
3460 * Now allocate a pty for the session.
3463 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3464 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3465 ssh2_pkt_addstring("pty-req");
3466 ssh2_pkt_addbool(1); /* want reply */
3467 ssh2_pkt_addstring(cfg.termtype);
3468 ssh2_pkt_adduint32(cols);
3469 ssh2_pkt_adduint32(rows);
3470 ssh2_pkt_adduint32(0); /* pixel width */
3471 ssh2_pkt_adduint32(0); /* pixel height */
3472 ssh2_pkt_addstring_start();
3473 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3475 ssh_state = SSH_STATE_INTERMED;
3478 crWaitUntilV(ispkt);
3479 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3480 unsigned i = ssh2_pkt_getuint32();
3481 struct ssh_channel *c;
3482 c = find234(ssh_channels, &i, ssh_channelfind);
3484 continue; /* nonexistent channel */
3485 c->v2.remwindow += ssh2_pkt_getuint32();
3487 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3489 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3490 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3491 bombout(("Server got confused by pty request"));
3494 c_write_str("Server refused to allocate pty\r\n");
3495 ssh_editing = ssh_echoing = 1;
3497 logevent("Allocated pty");
3500 ssh_editing = ssh_echoing = 1;
3504 * Start a shell or a remote command.
3506 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3507 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3508 if (cfg.ssh_subsys) {
3509 ssh2_pkt_addstring("subsystem");
3510 ssh2_pkt_addbool(1); /* want reply */
3511 ssh2_pkt_addstring(cfg.remote_cmd);
3512 } else if (*cfg.remote_cmd) {
3513 ssh2_pkt_addstring("exec");
3514 ssh2_pkt_addbool(1); /* want reply */
3515 ssh2_pkt_addstring(cfg.remote_cmd);
3517 ssh2_pkt_addstring("shell");
3518 ssh2_pkt_addbool(1); /* want reply */
3522 crWaitUntilV(ispkt);
3523 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3524 unsigned i = ssh2_pkt_getuint32();
3525 struct ssh_channel *c;
3526 c = find234(ssh_channels, &i, ssh_channelfind);
3528 continue; /* nonexistent channel */
3529 c->v2.remwindow += ssh2_pkt_getuint32();
3531 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3532 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3533 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3534 bombout(("Server got confused by shell/command request"));
3537 bombout(("Server refused to start a shell/command"));
3540 logevent("Started a shell/command");
3543 ssh_state = SSH_STATE_SESSION;
3547 ssh_special(TS_EOF);
3552 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
3555 static int try_send;
3559 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3560 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3563 unsigned i = ssh2_pkt_getuint32();
3564 struct ssh_channel *c;
3565 c = find234(ssh_channels, &i, ssh_channelfind);
3567 continue; /* nonexistent channel */
3568 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3569 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3570 continue; /* extended but not stderr */
3571 ssh2_pkt_getstring(&data, &length);
3574 case CHAN_MAINSESSION:
3575 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
3579 x11_send(c->u.x11.s, data, length);
3582 while (length > 0) {
3583 if (c->u.a.lensofar < 4) {
3584 int l = min(4 - c->u.a.lensofar, length);
3585 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
3586 data += l; length -= l; c->u.a.lensofar += l;
3588 if (c->u.a.lensofar == 4) {
3589 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
3590 c->u.a.message = smalloc(c->u.a.totallen);
3591 memcpy(c->u.a.message, c->u.a.msglen, 4);
3593 if (c->u.a.lensofar >= 4 && length > 0) {
3594 int l = min(c->u.a.totallen - c->u.a.lensofar,
3596 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
3597 data += l; length -= l; c->u.a.lensofar += l;
3599 if (c->u.a.lensofar == c->u.a.totallen) {
3600 void *reply, *sentreply;
3602 agent_query(c->u.a.message, c->u.a.totallen,
3607 /* Fake SSH_AGENT_FAILURE. */
3608 sentreply = "\0\0\0\1\5";
3611 ssh2_add_channel_data(c, sentreply, replylen);
3615 sfree(c->u.a.message);
3616 c->u.a.lensofar = 0;
3622 * Enlarge the window again at the remote
3623 * side, just in case it ever runs down and
3624 * they fail to send us any more data.
3626 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3627 ssh2_pkt_adduint32(c->remoteid);
3628 ssh2_pkt_adduint32(length);
3631 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
3632 ssh_state = SSH_STATE_CLOSED;
3633 logevent("Received disconnect message");
3635 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
3636 continue; /* exit status et al; ignore (FIXME?) */
3637 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
3638 unsigned i = ssh2_pkt_getuint32();
3639 struct ssh_channel *c;
3641 c = find234(ssh_channels, &i, ssh_channelfind);
3643 continue; /* nonexistent channel */
3645 if (c->type == CHAN_X11) {
3647 * Remote EOF on an X11 channel means we should
3648 * wrap up and close the channel ourselves.
3650 x11_close(c->u.x11.s);
3652 } else if (c->type == CHAN_AGENT) {
3655 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
3656 unsigned i = ssh2_pkt_getuint32();
3657 struct ssh_channel *c;
3660 c = find234(ssh_channels, &i, ssh_channelfind);
3662 continue; /* nonexistent channel */
3663 if (c->closes == 0) {
3664 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3665 ssh2_pkt_adduint32(c->remoteid);
3668 /* Do pre-close processing on the channel. */
3670 case CHAN_MAINSESSION:
3671 break; /* nothing to see here, move along */
3677 del234(ssh_channels, c);
3678 sfree(c->v2.outbuffer);
3682 * See if that was the last channel left open.
3684 c = first234(ssh_channels, &e);
3686 logevent("All channels closed. Disconnecting");
3687 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3688 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3689 ssh2_pkt_addstring("All open channels closed");
3690 ssh2_pkt_addstring("en"); /* language tag */
3692 ssh_state = SSH_STATE_CLOSED;
3695 continue; /* remote sends close; ignore (FIXME) */
3696 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3697 unsigned i = ssh2_pkt_getuint32();
3698 struct ssh_channel *c;
3699 c = find234(ssh_channels, &i, ssh_channelfind);
3701 continue; /* nonexistent channel */
3702 mainchan->v2.remwindow += ssh2_pkt_getuint32();
3704 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3708 struct ssh_channel *c;
3709 ssh2_pkt_getstring(&type, &typelen);
3710 c = smalloc(sizeof(struct ssh_channel));
3712 if (typelen == 3 && !memcmp(type, "x11", 3)) {
3713 if (!ssh_X11_fwd_enabled)
3714 error = "X11 forwarding is not enabled";
3715 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
3716 error = "Unable to open an X11 connection";
3720 } else if (typelen == 22 &&
3721 !memcmp(type, "auth-agent@openssh.com", 3)) {
3722 if (!ssh_agentfwd_enabled)
3723 error = "Agent forwarding is not enabled";
3725 c->type = CHAN_AGENT; /* identify channel type */
3726 c->u.a.lensofar = 0;
3729 error = "Unsupported channel type requested";
3732 c->remoteid = ssh2_pkt_getuint32();
3734 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3735 ssh2_pkt_adduint32(c->remoteid);
3736 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3737 ssh2_pkt_addstring(error);
3738 ssh2_pkt_addstring("en"); /* language tag */
3742 struct ssh_channel *d;
3746 for (i=1, d = first234(ssh_channels, &e); d;
3749 break; /* found a free number */
3754 c->v2.remwindow = ssh2_pkt_getuint32();
3755 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3756 c->v2.outbuffer = NULL;
3757 c->v2.outbuflen = c->v2.outbufsize = 0;
3758 add234(ssh_channels, c);
3759 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3760 ssh2_pkt_adduint32(c->remoteid);
3761 ssh2_pkt_adduint32(c->localid);
3762 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3763 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3767 bombout(("Strange packet received: type %d", pktin.type));
3772 * We have spare data. Add it to the channel buffer.
3774 ssh2_add_channel_data(mainchan, in, inlen);
3779 struct ssh_channel *c;
3781 * Try to send data on all channels if we can.
3783 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3792 * Handle the top-level SSH2 protocol.
3794 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3796 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3798 do_ssh2_authconn(in, inlen, ispkt);
3802 * Called to set up the connection.
3804 * Returns an error message, or NULL on success.
3806 static char *ssh_init (char *host, int port, char **realhost) {
3810 if(crypto_startup() == 0)
3811 return "Microsoft high encryption pack not installed!";
3818 p = connect_to_host(host, port, realhost);
3826 * Called to send data down the Telnet connection.
3828 static void ssh_send (char *buf, int len) {
3829 if (s == NULL || ssh_protocol == NULL)
3832 ssh_protocol(buf, len, 0);
3836 * Called to set the size of the window from SSH's POV.
3838 static void ssh_size(void) {
3839 switch (ssh_state) {
3840 case SSH_STATE_BEFORE_SIZE:
3841 case SSH_STATE_PREPACKET:
3842 case SSH_STATE_CLOSED:
3843 break; /* do nothing */
3844 case SSH_STATE_INTERMED:
3845 size_needed = TRUE; /* buffer for later */
3847 case SSH_STATE_SESSION:
3849 if (ssh_version == 1) {
3850 send_packet(SSH1_CMSG_WINDOW_SIZE,
3851 PKT_INT, rows, PKT_INT, cols,
3852 PKT_INT, 0, PKT_INT, 0, PKT_END);
3854 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3855 ssh2_pkt_adduint32(mainchan->remoteid);
3856 ssh2_pkt_addstring("window-change");
3857 ssh2_pkt_addbool(0);
3858 ssh2_pkt_adduint32(cols);
3859 ssh2_pkt_adduint32(rows);
3860 ssh2_pkt_adduint32(0);
3861 ssh2_pkt_adduint32(0);
3870 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3871 * can send an EOF and collect resulting output (e.g. `plink
3874 static void ssh_special (Telnet_Special code) {
3875 if (code == TS_EOF) {
3876 if (ssh_state != SSH_STATE_SESSION) {
3878 * Buffer the EOF in case we are pre-SESSION, so we can
3879 * send it as soon as we reach SESSION.
3885 if (ssh_version == 1) {
3886 send_packet(SSH1_CMSG_EOF, PKT_END);
3888 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
3889 ssh2_pkt_adduint32(mainchan->remoteid);
3892 logevent("Sent EOF message");
3893 } else if (code == TS_PING) {
3894 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3896 if (ssh_version == 1) {
3897 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3899 ssh2_pkt_init(SSH2_MSG_IGNORE);
3900 ssh2_pkt_addstring_start();
3908 static Socket ssh_socket(void) { return s; }
3910 static int ssh_sendok(void) { return ssh_send_ok; }
3912 static int ssh_ldisc(int option) {
3913 if (option == LD_ECHO) return ssh_echoing;
3914 if (option == LD_EDIT) return ssh_editing;
3918 Backend ssh_backend = {