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 SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
72 /* Mask for protoflags we will echo back to server if seen */
73 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
75 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
76 #define SSH2_MSG_IGNORE 2 /* 0x2 */
77 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
78 #define SSH2_MSG_DEBUG 4 /* 0x4 */
79 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
80 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
81 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
82 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
83 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
84 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
85 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
86 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
87 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
88 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
89 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
110 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
111 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
112 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
113 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
114 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
115 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
116 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
117 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
118 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
119 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
120 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
121 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
122 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
123 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
124 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
126 static const char *const ssh2_disconnect_reasons[] = {
128 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
129 "SSH_DISCONNECT_PROTOCOL_ERROR",
130 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
131 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
132 "SSH_DISCONNECT_MAC_ERROR",
133 "SSH_DISCONNECT_COMPRESSION_ERROR",
134 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
135 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
136 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
137 "SSH_DISCONNECT_CONNECTION_LOST",
138 "SSH_DISCONNECT_BY_APPLICATION",
139 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
140 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
141 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
142 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
145 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
146 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
147 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
148 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
150 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
153 * Various remote-bug flags.
155 #define BUG_CHOKES_ON_SSH1_IGNORE 1
156 #define BUG_SSH2_HMAC 2
158 #define GET_32BIT(cp) \
159 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
160 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
161 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
162 ((unsigned long)(unsigned char)(cp)[3]))
164 #define PUT_32BIT(cp, value) { \
165 (cp)[0] = (unsigned char)((value) >> 24); \
166 (cp)[1] = (unsigned char)((value) >> 16); \
167 (cp)[2] = (unsigned char)((value) >> 8); \
168 (cp)[3] = (unsigned char)(value); }
170 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
172 /* Coroutine mechanics for the sillier bits of the code */
173 #define crBegin1 static int crLine = 0;
174 #define crBegin2 switch(crLine) { case 0:;
175 #define crBegin crBegin1; crBegin2;
176 #define crFinish(z) } crLine = 0; return (z)
177 #define crFinishV } crLine = 0; return
178 #define crReturn(z) \
180 crLine=__LINE__; return (z); case __LINE__:;\
184 crLine=__LINE__; return; case __LINE__:;\
186 #define crStop(z) do{ crLine = 0; return (z); }while(0)
187 #define crStopV do{ crLine = 0; return; }while(0)
188 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
189 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
191 extern char *x11_init (Socket *, char *, void *);
192 extern void x11_close (Socket);
193 extern void x11_send (Socket , char *, int);
194 extern void x11_invent_auth(char *, int, char *, int);
197 * Ciphers for SSH2. We miss out single-DES because it isn't
198 * supported; also 3DES and Blowfish are both done differently from
199 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
200 * endianness and different-sized keys.)
202 const static struct ssh2_ciphers *ciphers[] = {
208 const static struct ssh_kex *kex_algs[] = {
209 &ssh_diffiehellman_gex,
210 &ssh_diffiehellman };
212 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
214 static void nullmac_key(unsigned char *key) { }
215 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
216 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
217 const static struct ssh_mac ssh_mac_none = {
218 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
220 const static struct ssh_mac *macs[] = {
221 &ssh_sha1, &ssh_md5, &ssh_mac_none };
222 const static struct ssh_mac *buggymacs[] = {
223 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
225 static void ssh_comp_none_init(void) { }
226 static int ssh_comp_none_block(unsigned char *block, int len,
227 unsigned char **outblock, int *outlen) {
230 static int ssh_comp_none_disable(void) { return 0; }
231 const static struct ssh_compress ssh_comp_none = {
233 ssh_comp_none_init, ssh_comp_none_block,
234 ssh_comp_none_init, ssh_comp_none_block,
235 ssh_comp_none_disable
237 extern const struct ssh_compress ssh_zlib;
238 const static struct ssh_compress *compressions[] = {
239 &ssh_zlib, &ssh_comp_none };
241 enum { /* channel types */
248 * 2-3-4 tree storing channels.
251 unsigned remoteid, localid;
254 struct ssh2_data_channel {
255 unsigned char *outbuffer;
256 unsigned outbuflen, outbufsize;
257 unsigned remwindow, remmaxpkt;
260 struct ssh_agent_channel {
261 unsigned char *message;
262 unsigned char msglen[4];
263 int lensofar, totallen;
265 struct ssh_x11_channel {
280 static SHA_State exhash, exhashbase;
282 static Socket s = NULL;
284 static unsigned char session_key[32];
285 static int ssh1_compressing;
286 static int ssh1_remote_protoflags;
287 static int ssh1_local_protoflags;
288 static int ssh_agentfwd_enabled;
289 static int ssh_X11_fwd_enabled;
290 static int ssh_remote_bugs;
291 static const struct ssh_cipher *cipher = NULL;
292 static const struct ssh2_cipher *cscipher = NULL;
293 static const struct ssh2_cipher *sccipher = NULL;
294 static const struct ssh_mac *csmac = NULL;
295 static const struct ssh_mac *scmac = NULL;
296 static const struct ssh_compress *cscomp = NULL;
297 static const struct ssh_compress *sccomp = NULL;
298 static const struct ssh_kex *kex = NULL;
299 static const struct ssh_signkey *hostkey = NULL;
300 static unsigned char ssh2_session_id[20];
301 int (*ssh_get_line)(const char *prompt, char *str, int maxlen,
304 static char *savedhost;
305 static int savedport;
306 static int ssh_send_ok;
307 static int ssh_echoing, ssh_editing;
309 static tree234 *ssh_channels; /* indexed by local id */
310 static struct ssh_channel *mainchan; /* primary session channel */
314 SSH_STATE_BEFORE_SIZE,
318 } ssh_state = SSH_STATE_PREPACKET;
320 static int size_needed = FALSE, eof_needed = FALSE;
322 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
323 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
324 static unsigned char *deferred_send_data = NULL;
325 static int deferred_len = 0, deferred_size = 0;
327 static int ssh_version;
328 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
329 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
330 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
331 static void ssh_size(void);
332 static void ssh_special (Telnet_Special);
333 static void ssh2_try_send(struct ssh_channel *c);
334 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
336 static int (*s_rdpkt)(unsigned char **data, int *datalen);
338 static struct rdpkt1_state_tag {
339 long len, pad, biglen, to_read;
340 unsigned long realcrc, gotcrc;
346 static struct rdpkt2_state_tag {
347 long len, pad, payload, packetlen, maclen;
350 unsigned long incoming_sequence;
353 static int ssh_channelcmp(void *av, void *bv) {
354 struct ssh_channel *a = (struct ssh_channel *)av;
355 struct ssh_channel *b = (struct ssh_channel *)bv;
356 if (a->localid < b->localid) return -1;
357 if (a->localid > b->localid) return +1;
360 static int ssh_channelfind(void *av, void *bv) {
361 unsigned *a = (unsigned *)av;
362 struct ssh_channel *b = (struct ssh_channel *)bv;
363 if (*a < b->localid) return -1;
364 if (*a > b->localid) return +1;
368 static int alloc_channel_id(void) {
369 const int CHANNEL_NUMBER_OFFSET = 256;
372 struct ssh_channel *c;
375 * First-fit allocation of channel numbers: always pick the
376 * lowest unused one. To do this, binary-search using the
377 * counted B-tree to find the largest channel ID which is in a
378 * contiguous sequence from the beginning. (Precisely
379 * everything in that sequence must have ID equal to its tree
380 * index plus CHANNEL_NUMBER_OFFSET.)
382 tsize = count234(ssh_channels);
384 low = -1; high = tsize;
385 while (high - low > 1) {
386 mid = (high + low) / 2;
387 c = index234(ssh_channels, mid);
388 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
389 low = mid; /* this one is fine */
391 high = mid; /* this one is past it */
394 * Now low points to either -1, or the tree index of the
395 * largest ID in the initial sequence.
398 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
399 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
401 return low + 1 + CHANNEL_NUMBER_OFFSET;
404 static void c_write (char *buf, int len) {
405 if ((flags & FLAG_STDERR)) {
407 for (i = 0; i < len; i++)
409 fputc(buf[i], stderr);
412 from_backend(1, buf, len);
415 static void c_write_untrusted(char *buf, int len) {
417 for (i = 0; i < len; i++) {
420 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
425 static void c_write_str (char *buf) {
426 c_write(buf, strlen(buf));
430 * Collect incoming data in the incoming packet buffer.
431 * Decipher and verify the packet when it is completely read.
432 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
433 * Update the *data and *datalen variables.
434 * Return the additional nr of bytes needed, or 0 when
435 * a complete packet is available.
437 static int ssh1_rdpkt(unsigned char **data, int *datalen)
439 struct rdpkt1_state_tag *st = &rdpkt1_state;
448 for (st->i = st->len = 0; st->i < 4; st->i++) {
449 while ((*datalen) == 0)
451 st->len = (st->len << 8) + **data;
452 (*data)++, (*datalen)--;
456 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
457 st->len = 0x300; /* big enough to carry to end */
461 st->pad = 8 - (st->len % 8);
462 st->biglen = st->len + st->pad;
463 pktin.length = st->len - 5;
465 if (pktin.maxlen < st->biglen) {
466 pktin.maxlen = st->biglen;
467 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
468 srealloc(pktin.data, st->biglen+APIEXTRA));
470 fatalbox("Out of memory");
473 st->to_read = st->biglen;
475 while (st->to_read > 0) {
476 st->chunk = st->to_read;
477 while ((*datalen) == 0)
478 crReturn(st->to_read);
479 if (st->chunk > (*datalen))
480 st->chunk = (*datalen);
481 memcpy(st->p, *data, st->chunk);
483 *datalen -= st->chunk;
485 st->to_read -= st->chunk;
489 cipher->decrypt(pktin.data, st->biglen);
491 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
492 for (st->i = 0; st->i < st->biglen; st->i++)
493 debug((" %02x", (unsigned char)pktin.data[st->i]));
497 st->realcrc = crc32(pktin.data, st->biglen-4);
498 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
499 if (st->gotcrc != st->realcrc) {
500 bombout(("Incorrect CRC received on packet"));
504 pktin.body = pktin.data + st->pad + 1;
506 if (ssh1_compressing) {
507 unsigned char *decompblk;
512 debug(("Packet payload pre-decompression:\n"));
513 for (i = -1; i < pktin.length; i++)
514 debug((" %02x", (unsigned char)pktin.body[i]));
518 zlib_decompress_block(pktin.body-1, pktin.length+1,
519 &decompblk, &decomplen);
521 if (pktin.maxlen < st->pad + decomplen) {
522 pktin.maxlen = st->pad + decomplen;
523 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
524 pktin.body = pktin.data + st->pad + 1;
526 fatalbox("Out of memory");
529 memcpy(pktin.body-1, decompblk, decomplen);
531 pktin.length = decomplen-1;
535 debug(("Packet payload post-decompression:\n"));
536 for (i = -1; i < pktin.length; i++)
537 debug((" %02x", (unsigned char)pktin.body[i]));
543 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
544 pktin.type == SSH1_SMSG_STDERR_DATA ||
545 pktin.type == SSH1_MSG_DEBUG ||
546 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
547 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
548 long strlen = GET_32BIT(pktin.body);
549 if (strlen + 4 != pktin.length) {
550 bombout(("Received data packet with bogus string length"));
555 pktin.type = pktin.body[-1];
557 if (pktin.type == SSH1_MSG_DEBUG) {
558 /* log debug message */
560 int strlen = GET_32BIT(pktin.body);
561 strcpy(buf, "Remote: ");
562 if (strlen > 70) strlen = 70;
563 memcpy(buf+8, pktin.body+4, strlen);
564 buf[8+strlen] = '\0';
567 } else if (pktin.type == SSH1_MSG_IGNORE) {
572 if (pktin.type == SSH1_MSG_DISCONNECT) {
573 /* log reason code in disconnect message */
575 int msglen = GET_32BIT(pktin.body);
577 strcpy(buf, "Remote sent disconnect: ");
578 nowlen = strlen(buf);
579 if (msglen > sizeof(buf)-nowlen-1)
580 msglen = sizeof(buf)-nowlen-1;
581 memcpy(buf+nowlen, pktin.body+4, msglen);
582 buf[nowlen+msglen] = '\0';
589 static int ssh2_rdpkt(unsigned char **data, int *datalen)
591 struct rdpkt2_state_tag *st = &rdpkt2_state;
599 st->cipherblk = sccipher->blksize;
602 if (st->cipherblk < 8)
605 if (pktin.maxlen < st->cipherblk) {
606 pktin.maxlen = st->cipherblk;
607 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
608 srealloc(pktin.data, st->cipherblk+APIEXTRA));
610 fatalbox("Out of memory");
614 * Acquire and decrypt the first block of the packet. This will
615 * contain the length and padding details.
617 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
618 while ((*datalen) == 0)
619 crReturn(st->cipherblk-st->i);
620 pktin.data[st->i] = *(*data)++;
624 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
629 sccipher->decrypt(pktin.data, st->cipherblk);
632 * Now get the length and padding figures.
634 st->len = GET_32BIT(pktin.data);
635 st->pad = pktin.data[4];
638 * This enables us to deduce the payload length.
640 st->payload = st->len - st->pad - 1;
642 pktin.length = st->payload + 5;
645 * So now we can work out the total packet length.
647 st->packetlen = st->len + 4;
648 st->maclen = scmac ? scmac->len : 0;
651 * Adjust memory allocation if packet is too big.
653 if (pktin.maxlen < st->packetlen+st->maclen) {
654 pktin.maxlen = st->packetlen+st->maclen;
655 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
656 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
658 fatalbox("Out of memory");
662 * Read and decrypt the remainder of the packet.
664 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
665 while ((*datalen) == 0)
666 crReturn(st->packetlen + st->maclen - st->i);
667 pktin.data[st->i] = *(*data)++;
670 /* Decrypt everything _except_ the MAC. */
672 sccipher->decrypt(pktin.data + st->cipherblk,
673 st->packetlen - st->cipherblk);
676 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
677 for (st->i = 0; st->i < st->packetlen; st->i++)
678 debug((" %02x", (unsigned char)pktin.data[st->i]));
685 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
686 bombout(("Incorrect MAC received on packet"));
689 st->incoming_sequence++; /* whether or not we MACed */
692 * Decompress packet payload.
695 unsigned char *newpayload;
697 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
698 &newpayload, &newlen)) {
699 if (pktin.maxlen < newlen+5) {
700 pktin.maxlen = newlen+5;
701 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
702 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
704 fatalbox("Out of memory");
706 pktin.length = 5 + newlen;
707 memcpy(pktin.data+5, newpayload, newlen);
709 debug(("Post-decompression payload:\r\n"));
710 for (st->i = 0; st->i < newlen; st->i++)
711 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
720 pktin.type = pktin.data[5];
722 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
723 goto next_packet; /* FIXME: print DEBUG message */
725 if (pktin.type == SSH2_MSG_DISCONNECT) {
726 /* log reason code in disconnect message */
728 int reason = GET_32BIT(pktin.data+6);
729 int msglen = GET_32BIT(pktin.data+10);
731 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
732 sprintf(buf, "Received disconnect message (%s)",
733 ssh2_disconnect_reasons[reason]);
735 sprintf(buf, "Received disconnect message (unknown type %d)", reason);
738 strcpy(buf, "Disconnection message text: ");
739 nowlen = strlen(buf);
740 if (msglen > sizeof(buf)-nowlen-1)
741 msglen = sizeof(buf)-nowlen-1;
742 memcpy(buf+nowlen, pktin.data+14, msglen);
743 buf[nowlen+msglen] = '\0';
750 static void ssh1_pktout_size(int len) {
753 len += 5; /* type and CRC */
757 pktout.length = len-5;
758 if (pktout.maxlen < biglen) {
759 pktout.maxlen = biglen;
761 /* Allocate enough buffer space for extra block
762 * for MS CryptEncrypt() */
763 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
764 srealloc(pktout.data, biglen+12));
766 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
767 srealloc(pktout.data, biglen+4));
770 fatalbox("Out of memory");
772 pktout.body = pktout.data+4+pad+1;
775 static void s_wrpkt_start(int type, int len) {
776 ssh1_pktout_size(len);
780 static int s_wrpkt_prepare(void) {
781 int pad, len, biglen, i;
784 pktout.body[-1] = pktout.type;
787 debug(("Packet payload pre-compression:\n"));
788 for (i = -1; i < pktout.length; i++)
789 debug((" %02x", (unsigned char)pktout.body[i]));
793 if (ssh1_compressing) {
794 unsigned char *compblk;
796 zlib_compress_block(pktout.body-1, pktout.length+1,
798 ssh1_pktout_size(complen-1);
799 memcpy(pktout.body-1, compblk, complen);
802 debug(("Packet payload post-compression:\n"));
803 for (i = -1; i < pktout.length; i++)
804 debug((" %02x", (unsigned char)pktout.body[i]));
809 len = pktout.length + 5; /* type and CRC */
813 for (i=0; i<pad; i++)
814 pktout.data[i+4] = random_byte();
815 crc = crc32(pktout.data+4, biglen-4);
816 PUT_32BIT(pktout.data+biglen, crc);
817 PUT_32BIT(pktout.data, len);
820 debug(("Sending packet len=%d\r\n", biglen+4));
821 for (i = 0; i < biglen+4; i++)
822 debug((" %02x", (unsigned char)pktout.data[i]));
826 cipher->encrypt(pktout.data+4, biglen);
831 static void s_wrpkt(void) {
833 len = s_wrpkt_prepare();
834 sk_write(s, pktout.data, len);
837 static void s_wrpkt_defer(void) {
839 len = s_wrpkt_prepare();
840 if (deferred_len + len > deferred_size) {
841 deferred_size = deferred_len + len + 128;
842 deferred_send_data = srealloc(deferred_send_data, deferred_size);
844 memcpy(deferred_send_data+deferred_len, pktout.data, len);
849 * Construct a packet with the specified contents.
851 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
853 unsigned char *p, *argp, argchar;
854 unsigned long argint;
855 int pktlen, argtype, arglen;
859 while ((argtype = va_arg(ap1, int)) != PKT_END) {
862 (void) va_arg(ap1, int);
866 (void) va_arg(ap1, char);
870 (void) va_arg(ap1, unsigned char *);
871 arglen = va_arg(ap1, int);
875 argp = va_arg(ap1, unsigned char *);
876 arglen = strlen(argp);
877 pktlen += 4 + arglen;
880 bn = va_arg(ap1, Bignum);
881 pktlen += ssh1_bignum_length(bn);
888 s_wrpkt_start(pkttype, pktlen);
891 while ((argtype = va_arg(ap2, int)) != PKT_END) {
894 argint = va_arg(ap2, int);
895 PUT_32BIT(p, argint);
899 argchar = va_arg(ap2, unsigned char);
904 argp = va_arg(ap2, unsigned char *);
905 arglen = va_arg(ap2, int);
906 memcpy(p, argp, arglen);
910 argp = va_arg(ap2, unsigned char *);
911 arglen = strlen(argp);
912 PUT_32BIT(p, arglen);
913 memcpy(p + 4, argp, arglen);
917 bn = va_arg(ap2, Bignum);
918 p += ssh1_write_bignum(p, bn);
924 static void send_packet(int pkttype, ...) {
926 va_start(ap1, pkttype);
927 va_start(ap2, pkttype);
928 construct_packet(pkttype, ap1, ap2);
932 static void defer_packet(int pkttype, ...) {
934 va_start(ap1, pkttype);
935 va_start(ap2, pkttype);
936 construct_packet(pkttype, ap1, ap2);
940 static int ssh_versioncmp(char *a, char *b) {
942 unsigned long av, bv;
944 av = strtoul(a, &ae, 10);
945 bv = strtoul(b, &be, 10);
946 if (av != bv) return (av < bv ? -1 : +1);
947 if (*ae == '.') ae++;
948 if (*be == '.') be++;
949 av = strtoul(ae, &ae, 10);
950 bv = strtoul(be, &be, 10);
951 if (av != bv) return (av < bv ? -1 : +1);
957 * Utility routines for putting an SSH-protocol `string' and
958 * `uint32' into a SHA state.
961 static void sha_string(SHA_State *s, void *str, int len) {
962 unsigned char lenblk[4];
963 PUT_32BIT(lenblk, len);
964 SHA_Bytes(s, lenblk, 4);
965 SHA_Bytes(s, str, len);
968 static void sha_uint32(SHA_State *s, unsigned i) {
969 unsigned char intblk[4];
970 PUT_32BIT(intblk, i);
971 SHA_Bytes(s, intblk, 4);
975 * SSH2 packet construction functions.
977 static void ssh2_pkt_ensure(int length) {
978 if (pktout.maxlen < length) {
979 pktout.maxlen = length + 256;
980 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
981 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
983 fatalbox("Out of memory");
986 static void ssh2_pkt_adddata(void *data, int len) {
987 pktout.length += len;
988 ssh2_pkt_ensure(pktout.length);
989 memcpy(pktout.data+pktout.length-len, data, len);
991 static void ssh2_pkt_addbyte(unsigned char byte) {
992 ssh2_pkt_adddata(&byte, 1);
994 static void ssh2_pkt_init(int pkt_type) {
996 ssh2_pkt_addbyte((unsigned char)pkt_type);
998 static void ssh2_pkt_addbool(unsigned char value) {
999 ssh2_pkt_adddata(&value, 1);
1001 static void ssh2_pkt_adduint32(unsigned long value) {
1003 PUT_32BIT(x, value);
1004 ssh2_pkt_adddata(x, 4);
1006 static void ssh2_pkt_addstring_start(void) {
1007 ssh2_pkt_adduint32(0);
1008 pktout.savedpos = pktout.length;
1010 static void ssh2_pkt_addstring_str(char *data) {
1011 ssh2_pkt_adddata(data, strlen(data));
1012 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1013 pktout.length - pktout.savedpos);
1015 static void ssh2_pkt_addstring_data(char *data, int len) {
1016 ssh2_pkt_adddata(data, len);
1017 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1018 pktout.length - pktout.savedpos);
1020 static void ssh2_pkt_addstring(char *data) {
1021 ssh2_pkt_addstring_start();
1022 ssh2_pkt_addstring_str(data);
1024 static char *ssh2_mpint_fmt(Bignum b, int *len) {
1026 int i, n = (bignum_bitcount(b)+7)/8;
1029 fatalbox("out of memory");
1031 for (i = 1; i <= n; i++)
1032 p[i] = bignum_byte(b, n-i);
1034 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
1036 memmove(p, p+i, n+1-i);
1040 static void ssh2_pkt_addmp(Bignum b) {
1043 p = ssh2_mpint_fmt(b, &len);
1044 ssh2_pkt_addstring_start();
1045 ssh2_pkt_addstring_data(p, len);
1050 * Construct an SSH2 final-form packet: compress it, encrypt it,
1051 * put the MAC on it. Final packet, ready to be sent, is stored in
1052 * pktout.data. Total length is returned.
1054 static int ssh2_pkt_construct(void) {
1055 int cipherblk, maclen, padding, i;
1056 static unsigned long outgoing_sequence = 0;
1059 * Compress packet payload.
1062 debug(("Pre-compression payload:\r\n"));
1063 for (i = 5; i < pktout.length; i++)
1064 debug((" %02x", (unsigned char)pktout.data[i]));
1068 unsigned char *newpayload;
1070 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
1071 &newpayload, &newlen)) {
1073 ssh2_pkt_adddata(newpayload, newlen);
1079 * Add padding. At least four bytes, and must also bring total
1080 * length (minus MAC) up to a multiple of the block size.
1082 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1083 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1085 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1086 maclen = csmac ? csmac->len : 0;
1087 ssh2_pkt_ensure(pktout.length + padding + maclen);
1088 pktout.data[4] = padding;
1089 for (i = 0; i < padding; i++)
1090 pktout.data[pktout.length + i] = random_byte();
1091 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1093 csmac->generate(pktout.data, pktout.length + padding,
1095 outgoing_sequence++; /* whether or not we MACed */
1098 debug(("Sending packet len=%d\r\n", pktout.length+padding));
1099 for (i = 0; i < pktout.length+padding; i++)
1100 debug((" %02x", (unsigned char)pktout.data[i]));
1105 cscipher->encrypt(pktout.data, pktout.length + padding);
1107 /* Ready-to-send packet starts at pktout.data. We return length. */
1108 return pktout.length + padding + maclen;
1112 * Construct and send an SSH2 packet immediately.
1114 static void ssh2_pkt_send(void) {
1115 int len = ssh2_pkt_construct();
1116 sk_write(s, pktout.data, len);
1120 * Construct an SSH2 packet and add it to a deferred data block.
1121 * Useful for sending multiple packets in a single sk_write() call,
1122 * to prevent a traffic-analysing listener from being able to work
1123 * out the length of any particular packet (such as the password
1126 * Note that because SSH2 sequence-numbers its packets, this can
1127 * NOT be used as an m4-style `defer' allowing packets to be
1128 * constructed in one order and sent in another.
1130 static void ssh2_pkt_defer(void) {
1131 int len = ssh2_pkt_construct();
1132 if (deferred_len + len > deferred_size) {
1133 deferred_size = deferred_len + len + 128;
1134 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1136 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1137 deferred_len += len;
1141 * Send the whole deferred data block constructed by
1142 * ssh2_pkt_defer() or SSH1's defer_packet().
1144 static void ssh_pkt_defersend(void) {
1145 sk_write(s, deferred_send_data, deferred_len);
1146 deferred_len = deferred_size = 0;
1147 sfree(deferred_send_data);
1148 deferred_send_data = NULL;
1152 void bndebug(char *string, Bignum b) {
1155 p = ssh2_mpint_fmt(b, &len);
1156 debug(("%s", string));
1157 for (i = 0; i < len; i++)
1158 debug((" %02x", p[i]));
1164 static void sha_mpint(SHA_State *s, Bignum b) {
1167 p = ssh2_mpint_fmt(b, &len);
1168 sha_string(s, p, len);
1173 * SSH2 packet decode functions.
1175 static unsigned long ssh2_pkt_getuint32(void) {
1176 unsigned long value;
1177 if (pktin.length - pktin.savedpos < 4)
1178 return 0; /* arrgh, no way to decline (FIXME?) */
1179 value = GET_32BIT(pktin.data+pktin.savedpos);
1180 pktin.savedpos += 4;
1183 static int ssh2_pkt_getbool(void) {
1184 unsigned long value;
1185 if (pktin.length - pktin.savedpos < 1)
1186 return 0; /* arrgh, no way to decline (FIXME?) */
1187 value = pktin.data[pktin.savedpos] != 0;
1191 static void ssh2_pkt_getstring(char **p, int *length) {
1193 if (pktin.length - pktin.savedpos < 4)
1195 *length = GET_32BIT(pktin.data+pktin.savedpos);
1196 pktin.savedpos += 4;
1197 if (pktin.length - pktin.savedpos < *length)
1199 *p = pktin.data+pktin.savedpos;
1200 pktin.savedpos += *length;
1202 static Bignum ssh2_pkt_getmp(void) {
1207 ssh2_pkt_getstring(&p, &length);
1211 bombout(("internal error: Can't handle negative mpints"));
1214 b = bignum_from_bytes(p, length);
1219 * Examine the remote side's version string and compare it against
1220 * a list of known buggy implementations.
1222 static void ssh_detect_bugs(char *vstring) {
1223 char *imp; /* pointer to implementation part */
1225 imp += strcspn(imp, "-");
1227 imp += strcspn(imp, "-");
1230 ssh_remote_bugs = 0;
1232 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1233 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1234 !strcmp(imp, "1.2.22")) {
1236 * These versions don't support SSH1_MSG_IGNORE, so we have
1237 * to use a different defence against password length
1240 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1241 logevent("We believe remote version has SSH1 ignore bug");
1244 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1245 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1246 !strncmp(imp, "2.1 ", 4)) {
1248 * These versions have the HMAC bug.
1250 ssh_remote_bugs |= BUG_SSH2_HMAC;
1251 logevent("We believe remote version has SSH2 HMAC bug");
1255 static int do_ssh_init(unsigned char c) {
1257 static char version[10];
1258 static char *vstring;
1259 static int vstrsize;
1265 /* Search for the string "SSH-" in the input. */
1268 static const int transS[] = { 1, 2, 2, 1 };
1269 static const int transH[] = { 0, 0, 3, 0 };
1270 static const int transminus[] = { 0, 0, 0, -1 };
1271 if (c == 'S') i = transS[i];
1272 else if (c == 'H') i = transH[i];
1273 else if (c == '-') i = transminus[i];
1277 crReturn(1); /* get another character */
1280 vstring = smalloc(16);
1282 strcpy(vstring, "SSH-");
1286 crReturn(1); /* get another char */
1287 if (vslen >= vstrsize-1) {
1289 vstring = srealloc(vstring, vstrsize);
1291 vstring[vslen++] = c;
1296 } else if (i < sizeof(version)-1)
1303 ssh_agentfwd_enabled = FALSE;
1304 rdpkt2_state.incoming_sequence = 0;
1307 vlog = smalloc(20 + vslen);
1308 sprintf(vlog, "Server version: %s", vstring);
1309 ssh_detect_bugs(vstring);
1310 vlog[strcspn(vlog, "\r\n")] = '\0';
1315 * Server version "1.99" means we can choose whether we use v1
1316 * or v2 protocol. Choice is based on cfg.sshprot.
1318 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1320 * This is a v2 server. Begin v2 protocol.
1322 char verstring[80], vlog[100];
1323 sprintf(verstring, "SSH-2.0-%s", sshver);
1324 SHA_Init(&exhashbase);
1326 * Hash our version string and their version string.
1328 sha_string(&exhashbase, verstring, strlen(verstring));
1329 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1330 sprintf(vlog, "We claim version: %s", verstring);
1332 strcat(verstring, "\n");
1333 logevent("Using SSH protocol version 2");
1334 sk_write(s, verstring, strlen(verstring));
1335 ssh_protocol = ssh2_protocol;
1337 s_rdpkt = ssh2_rdpkt;
1340 * This is a v1 server. Begin v1 protocol.
1342 char verstring[80], vlog[100];
1343 sprintf(verstring, "SSH-%s-%s",
1344 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1346 sprintf(vlog, "We claim version: %s", verstring);
1348 strcat(verstring, "\n");
1349 logevent("Using SSH protocol version 1");
1350 sk_write(s, verstring, strlen(verstring));
1351 ssh_protocol = ssh1_protocol;
1353 s_rdpkt = ssh1_rdpkt;
1355 ssh_state = SSH_STATE_BEFORE_SIZE;
1362 static void ssh_gotdata(unsigned char *data, int datalen)
1367 * To begin with, feed the characters one by one to the
1368 * protocol initialisation / selection function do_ssh_init().
1369 * When that returns 0, we're done with the initial greeting
1370 * exchange and can move on to packet discipline.
1375 crReturnV; /* more data please */
1376 ret = do_ssh_init(*data);
1383 * We emerge from that loop when the initial negotiation is
1384 * over and we have selected an s_rdpkt function. Now pass
1385 * everything to s_rdpkt, and then pass the resulting packets
1386 * to the proper protocol handler.
1391 while (datalen > 0) {
1392 if ( s_rdpkt(&data, &datalen) == 0 ) {
1393 ssh_protocol(NULL, 0, 1);
1394 if (ssh_state == SSH_STATE_CLOSED) {
1404 static int ssh_closing (Plug plug, char *error_msg, int error_code, int calling_back) {
1405 ssh_state = SSH_STATE_CLOSED;
1409 /* A socket error has occurred. */
1410 connection_fatal (error_msg);
1412 /* Otherwise, the remote side closed the connection normally. */
1417 static int ssh_receive(Plug plug, int urgent, char *data, int len) {
1418 ssh_gotdata (data, len);
1419 if (ssh_state == SSH_STATE_CLOSED) {
1430 * Connect to specified host and port.
1431 * Returns an error message, or NULL on success.
1432 * Also places the canonical host name into `realhost'.
1434 static char *connect_to_host(char *host, int port, char **realhost)
1436 static struct plug_function_table fn_table = {
1439 }, *fn_table_ptr = &fn_table;
1448 savedhost = smalloc(1+strlen(host));
1450 fatalbox("Out of memory");
1451 strcpy(savedhost, host);
1454 port = 22; /* default ssh port */
1467 addr = sk_namelookup(host, realhost);
1468 if ( (err = sk_addr_error(addr)) )
1478 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1479 if ( (err = sk_socket_error(s)) )
1483 sk_write(s, "connect ", 8);
1484 sk_write(s, FWhost, strlen(FWhost));
1487 sprintf(buf, " %d\n", FWport);
1488 sk_write(s, buf, strlen(buf));
1496 * Handle the key exchange and user authentication phases.
1498 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1501 unsigned char *rsabuf, *keystr1, *keystr2;
1502 unsigned char cookie[8];
1503 struct RSAKey servkey, hostkey;
1504 struct MD5Context md5c;
1505 static unsigned long supported_ciphers_mask, supported_auths_mask;
1506 static int tried_publickey;
1507 static unsigned char session_id[16];
1509 static char username[100];
1513 if (!ispkt) crWaitUntil(ispkt);
1515 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1516 bombout(("Public key packet not received"));
1520 logevent("Received public keys");
1522 memcpy(cookie, pktin.body, 8);
1524 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1525 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1528 * Log the host key fingerprint.
1532 logevent("Host key fingerprint is:");
1533 strcpy(logmsg, " ");
1534 hostkey.comment = NULL;
1535 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1540 ssh1_remote_protoflags = GET_32BIT(pktin.body+8+i+j);
1541 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1542 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1544 ssh1_local_protoflags = ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1545 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1548 MD5Update(&md5c, keystr2, hostkey.bytes);
1549 MD5Update(&md5c, keystr1, servkey.bytes);
1550 MD5Update(&md5c, pktin.body, 8);
1551 MD5Final(session_id, &md5c);
1553 for (i=0; i<32; i++)
1554 session_key[i] = random_byte();
1556 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1558 rsabuf = smalloc(len);
1560 fatalbox("Out of memory");
1563 * Verify the host key.
1567 * First format the key into a string.
1569 int len = rsastr_len(&hostkey);
1570 char fingerprint[100];
1571 char *keystr = smalloc(len);
1573 fatalbox("Out of memory");
1574 rsastr_fmt(keystr, &hostkey);
1575 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1576 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1580 for (i=0; i<32; i++) {
1581 rsabuf[i] = session_key[i];
1583 rsabuf[i] ^= session_id[i];
1586 if (hostkey.bytes > servkey.bytes) {
1587 rsaencrypt(rsabuf, 32, &servkey);
1588 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1590 rsaencrypt(rsabuf, 32, &hostkey);
1591 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1594 logevent("Encrypted session key");
1596 switch (cfg.cipher) {
1597 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break;
1598 case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break;
1599 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break;
1601 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1602 cipher_type = SSH_CIPHER_3DES;
1605 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1606 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
1607 cipher_type = SSH_CIPHER_3DES;
1608 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1609 bombout(("Server violates SSH 1 protocol by "
1610 "not supporting 3DES encryption"));
1614 switch (cipher_type) {
1615 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1616 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1617 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1620 send_packet(SSH1_CMSG_SESSION_KEY,
1621 PKT_CHAR, cipher_type,
1622 PKT_DATA, cookie, 8,
1623 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1624 PKT_DATA, rsabuf, len,
1625 PKT_INT, ssh1_local_protoflags,
1628 logevent("Trying to enable encryption...");
1632 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1633 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1635 cipher->sesskey(session_key);
1639 if (pktin.type != SSH1_SMSG_SUCCESS) {
1640 bombout(("Encryption not successfully enabled"));
1644 logevent("Successfully started encryption");
1650 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1652 if (!ssh_get_line("login as: ",
1653 username, sizeof(username), FALSE)) {
1655 * get_line failed to get a username.
1658 logevent("No username provided. Abandoning session.");
1659 ssh_state = SSH_STATE_CLOSED;
1663 c_write_str("login as: ");
1666 crWaitUntil(!ispkt);
1667 while (inlen--) switch (c = *in++) {
1674 c_write_str("\b \b");
1680 c_write_str("\b \b");
1689 if (((c >= ' ' && c <= '~') ||
1690 ((unsigned char)c >= 160)) && pos < 40) {
1691 username[pos++] = c;
1697 c_write_str("\r\n");
1698 username[strcspn(username, "\n\r")] = '\0';
1701 strncpy(username, cfg.username, 99);
1702 username[99] = '\0';
1705 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1707 char userlog[22+sizeof(username)];
1708 sprintf(userlog, "Sent username \"%s\"", username);
1710 if (flags & FLAG_INTERACTIVE &&
1711 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1712 strcat(userlog, "\r\n");
1713 c_write_str(userlog);
1720 tried_publickey = 0;
1722 while (pktin.type == SSH1_SMSG_FAILURE) {
1723 static char password[100];
1724 static char prompt[200];
1727 static int pwpkt_type;
1729 * Show password prompt, having first obtained it via a TIS
1730 * or CryptoCard exchange if we're doing TIS or CryptoCard
1733 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1734 if (agent_exists()) {
1736 * Attempt RSA authentication using Pageant.
1738 static unsigned char request[5], *response, *p;
1739 static int responselen;
1740 static int i, nkeys;
1741 static int authed = FALSE;
1744 logevent("Pageant is running. Requesting keys.");
1746 /* Request the keys held by the agent. */
1747 PUT_32BIT(request, 1);
1748 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1749 agent_query(request, 5, &r, &responselen);
1750 response = (unsigned char *)r;
1751 if (response && responselen >= 5 &&
1752 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
1754 nkeys = GET_32BIT(p); p += 4;
1755 { char buf[64]; sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1757 for (i = 0; i < nkeys; i++) {
1758 static struct RSAKey key;
1759 static Bignum challenge;
1760 static char *commentp;
1761 static int commentlen;
1763 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1766 p += ssh1_read_bignum(p, &key.exponent);
1767 p += ssh1_read_bignum(p, &key.modulus);
1768 commentlen = GET_32BIT(p); p += 4;
1769 commentp = p; p += commentlen;
1770 send_packet(SSH1_CMSG_AUTH_RSA,
1771 PKT_BIGNUM, key.modulus, PKT_END);
1773 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1774 logevent("Key refused");
1777 logevent("Received RSA challenge");
1778 ssh1_read_bignum(pktin.body, &challenge);
1780 char *agentreq, *q, *ret;
1782 len = 1 + 4; /* message type, bit count */
1783 len += ssh1_bignum_length(key.exponent);
1784 len += ssh1_bignum_length(key.modulus);
1785 len += ssh1_bignum_length(challenge);
1786 len += 16; /* session id */
1787 len += 4; /* response format */
1788 agentreq = smalloc(4 + len);
1789 PUT_32BIT(agentreq, len);
1791 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1792 PUT_32BIT(q, bignum_bitcount(key.modulus));
1794 q += ssh1_write_bignum(q, key.exponent);
1795 q += ssh1_write_bignum(q, key.modulus);
1796 q += ssh1_write_bignum(q, challenge);
1797 memcpy(q, session_id, 16); q += 16;
1798 PUT_32BIT(q, 1); /* response format */
1799 agent_query(agentreq, len+4, &ret, &retlen);
1802 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1803 logevent("Sending Pageant's response");
1804 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1805 PKT_DATA, ret+5, 16, PKT_END);
1808 if (pktin.type == SSH1_SMSG_SUCCESS) {
1809 logevent("Pageant's response accepted");
1810 if (flags & FLAG_VERBOSE) {
1811 c_write_str("Authenticated using RSA key \"");
1812 c_write(commentp, commentlen);
1813 c_write_str("\" from agent\r\n");
1817 logevent("Pageant's response not accepted");
1819 logevent("Pageant failed to answer challenge");
1823 logevent("No reply received from Pageant");
1826 freebn(key.exponent);
1827 freebn(key.modulus);
1836 if (*cfg.keyfile && !tried_publickey)
1837 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1839 if (pktin.type == SSH1_SMSG_FAILURE &&
1841 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1842 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1843 logevent("Requested TIS authentication");
1844 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1846 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1847 logevent("TIS authentication declined");
1848 if (flags & FLAG_INTERACTIVE)
1849 c_write_str("TIS authentication refused.\r\n");
1851 int challengelen = ((pktin.body[0] << 24) |
1852 (pktin.body[1] << 16) |
1853 (pktin.body[2] << 8) |
1855 logevent("Received TIS challenge");
1856 if (challengelen > sizeof(prompt)-1)
1857 challengelen = sizeof(prompt)-1; /* prevent overrun */
1858 memcpy(prompt, pktin.body+4, challengelen);
1859 prompt[challengelen] = '\0';
1862 if (pktin.type == SSH1_SMSG_FAILURE &&
1864 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1865 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1866 logevent("Requested CryptoCard authentication");
1867 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1869 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1870 logevent("CryptoCard authentication declined");
1871 c_write_str("CryptoCard authentication refused.\r\n");
1873 int challengelen = ((pktin.body[0] << 24) |
1874 (pktin.body[1] << 16) |
1875 (pktin.body[2] << 8) |
1877 logevent("Received CryptoCard challenge");
1878 if (challengelen > sizeof(prompt)-1)
1879 challengelen = sizeof(prompt)-1; /* prevent overrun */
1880 memcpy(prompt, pktin.body+4, challengelen);
1881 strncpy(prompt + challengelen, "\r\nResponse : ",
1882 sizeof(prompt)-challengelen);
1883 prompt[sizeof(prompt)-1] = '\0';
1886 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1887 sprintf(prompt, "%.90s@%.90s's password: ",
1888 username, savedhost);
1890 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1891 char *comment = NULL;
1892 if (flags & FLAG_VERBOSE)
1893 c_write_str("Trying public key authentication.\r\n");
1894 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1895 if (flags & FLAG_VERBOSE)
1896 c_write_str("No passphrase required.\r\n");
1899 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1904 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
1906 * get_line failed to get a password (for example
1907 * because one was supplied on the command line
1908 * which has already failed to work). Terminate.
1910 logevent("No more passwords to try");
1911 ssh_state = SSH_STATE_CLOSED;
1915 c_write_str(prompt);
1919 crWaitUntil(!ispkt);
1920 while (inlen--) switch (c = *in++) {
1937 if (((c >= ' ' && c <= '~') ||
1938 ((unsigned char)c >= 160)) && pos < sizeof(password))
1939 password[pos++] = c;
1943 c_write_str("\r\n");
1947 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1949 * Try public key authentication with the specified
1952 static struct RSAKey pubkey;
1953 static Bignum challenge, response;
1955 static unsigned char buffer[32];
1957 tried_publickey = 1;
1958 i = loadrsakey(cfg.keyfile, &pubkey, password);
1960 c_write_str("Couldn't load public key from ");
1961 c_write_str(cfg.keyfile);
1962 c_write_str(".\r\n");
1963 continue; /* go and try password */
1966 c_write_str("Wrong passphrase.\r\n");
1967 tried_publickey = 0;
1968 continue; /* try again */
1972 * Send a public key attempt.
1974 send_packet(SSH1_CMSG_AUTH_RSA,
1975 PKT_BIGNUM, pubkey.modulus, PKT_END);
1978 if (pktin.type == SSH1_SMSG_FAILURE) {
1979 c_write_str("Server refused our public key.\r\n");
1980 continue; /* go and try password */
1982 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1983 bombout(("Bizarre response to offer of public key"));
1986 ssh1_read_bignum(pktin.body, &challenge);
1987 response = rsadecrypt(challenge, &pubkey);
1988 freebn(pubkey.private_exponent); /* burn the evidence */
1990 for (i = 0; i < 32; i++) {
1991 buffer[i] = bignum_byte(response, 31-i);
1995 MD5Update(&md5c, buffer, 32);
1996 MD5Update(&md5c, session_id, 16);
1997 MD5Final(buffer, &md5c);
1999 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2000 PKT_DATA, buffer, 16, PKT_END);
2003 if (pktin.type == SSH1_SMSG_FAILURE) {
2004 if (flags & FLAG_VERBOSE)
2005 c_write_str("Failed to authenticate with our public key.\r\n");
2006 continue; /* go and try password */
2007 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2008 bombout(("Bizarre response to RSA authentication response"));
2012 break; /* we're through! */
2014 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2016 * Defence against traffic analysis: we send a
2017 * whole bunch of packets containing strings of
2018 * different lengths. One of these strings is the
2019 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2020 * The others are all random data in
2021 * SSH1_MSG_IGNORE packets. This way a passive
2022 * listener can't tell which is the password, and
2023 * hence can't deduce the password length.
2025 * Anybody with a password length greater than 16
2026 * bytes is going to have enough entropy in their
2027 * password that a listener won't find it _that_
2028 * much help to know how long it is. So what we'll
2031 * - if password length < 16, we send 15 packets
2032 * containing string lengths 1 through 15
2034 * - otherwise, we let N be the nearest multiple
2035 * of 8 below the password length, and send 8
2036 * packets containing string lengths N through
2037 * N+7. This won't obscure the order of
2038 * magnitude of the password length, but it will
2039 * introduce a bit of extra uncertainty.
2041 * A few servers (the old 1.2.18 through 1.2.22)
2042 * can't deal with SSH1_MSG_IGNORE. For these
2043 * servers, we need an alternative defence. We make
2044 * use of the fact that the password is interpreted
2045 * as a C string: so we can append a NUL, then some
2048 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2053 len = strlen(password);
2054 if (len < sizeof(string)) {
2056 strcpy(string, password);
2057 len++; /* cover the zero byte */
2058 while (len < sizeof(string)) {
2059 string[len++] = (char)random_byte();
2064 send_packet(pwpkt_type, PKT_INT, len,
2065 PKT_DATA, s, len, PKT_END);
2067 int bottom, top, pwlen, i;
2070 pwlen = strlen(password);
2072 bottom = 0; /* zero length passwords are OK! :-) */
2075 bottom = pwlen &~ 7;
2079 assert(pwlen >= bottom && pwlen <= top);
2081 randomstr = smalloc(top+1);
2083 for (i = bottom; i <= top; i++) {
2085 defer_packet(pwpkt_type, PKT_STR, password, PKT_END);
2087 for (j = 0; j < i; j++) {
2089 randomstr[j] = random_byte();
2090 } while (randomstr[j] == '\0');
2092 randomstr[i] = '\0';
2093 defer_packet(SSH1_MSG_IGNORE,
2094 PKT_STR, randomstr, PKT_END);
2097 ssh_pkt_defersend();
2100 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2103 logevent("Sent password");
2104 memset(password, 0, strlen(password));
2106 if (pktin.type == SSH1_SMSG_FAILURE) {
2107 if (flags & FLAG_VERBOSE)
2108 c_write_str("Access denied\r\n");
2109 logevent("Authentication refused");
2110 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2111 logevent("Received disconnect request");
2112 ssh_state = SSH_STATE_CLOSED;
2114 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2115 bombout(("Strange packet received, type %d", pktin.type));
2120 logevent("Authentication successful");
2125 void sshfwd_close(struct ssh_channel *c) {
2126 if (c && !c->closes) {
2127 if (ssh_version == 1) {
2128 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
2130 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2131 ssh2_pkt_adduint32(c->remoteid);
2135 if (c->type == CHAN_X11) {
2137 logevent("X11 connection terminated");
2142 void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
2143 if (ssh_version == 1) {
2144 send_packet(SSH1_MSG_CHANNEL_DATA,
2145 PKT_INT, c->remoteid,
2150 ssh2_add_channel_data(c, buf, len);
2155 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
2160 while (!do_ssh1_login(in, inlen, ispkt)) {
2163 if (ssh_state == SSH_STATE_CLOSED)
2166 if (cfg.agentfwd && agent_exists()) {
2167 logevent("Requesting agent forwarding");
2168 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2169 do { crReturnV; } while (!ispkt);
2170 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2171 bombout(("Protocol confusion"));
2173 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2174 logevent("Agent forwarding refused");
2176 logevent("Agent forwarding enabled");
2177 ssh_agentfwd_enabled = TRUE;
2181 if (cfg.x11_forward) {
2182 char proto[20], data[64];
2183 logevent("Requesting X11 forwarding");
2184 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2185 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2186 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2187 PKT_STR, proto, PKT_STR, data,
2191 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2192 PKT_STR, proto, PKT_STR, data,
2195 do { crReturnV; } while (!ispkt);
2196 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2197 bombout(("Protocol confusion"));
2199 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2200 logevent("X11 forwarding refused");
2202 logevent("X11 forwarding enabled");
2203 ssh_X11_fwd_enabled = TRUE;
2208 send_packet(SSH1_CMSG_REQUEST_PTY,
2209 PKT_STR, cfg.termtype,
2210 PKT_INT, rows, PKT_INT, cols,
2211 PKT_INT, 0, PKT_INT, 0,
2214 ssh_state = SSH_STATE_INTERMED;
2215 do { crReturnV; } while (!ispkt);
2216 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2217 bombout(("Protocol confusion"));
2219 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2220 c_write_str("Server refused to allocate pty\r\n");
2221 ssh_editing = ssh_echoing = 1;
2223 logevent("Allocated pty");
2225 ssh_editing = ssh_echoing = 1;
2228 if (cfg.compression) {
2229 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2230 do { crReturnV; } while (!ispkt);
2231 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2232 bombout(("Protocol confusion"));
2234 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2235 c_write_str("Server refused to compress\r\n");
2237 logevent("Started compression");
2238 ssh1_compressing = TRUE;
2239 zlib_compress_init();
2240 zlib_decompress_init();
2243 if (*cfg.remote_cmd_ptr)
2244 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr, PKT_END);
2246 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2247 logevent("Started session");
2249 ssh_state = SSH_STATE_SESSION;
2253 ssh_special(TS_EOF);
2255 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2257 ssh_channels = newtree234(ssh_channelcmp);
2261 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2262 pktin.type == SSH1_SMSG_STDERR_DATA) {
2263 long len = GET_32BIT(pktin.body);
2264 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2266 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2267 ssh_state = SSH_STATE_CLOSED;
2268 logevent("Received disconnect request");
2270 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2271 /* Remote side is trying to open a channel to talk to our
2272 * X-Server. Give them back a local channel number. */
2273 struct ssh_channel *c, *d;
2275 logevent("Received X11 connect request");
2276 /* Refuse if X11 forwarding is disabled. */
2277 if (!ssh_X11_fwd_enabled) {
2278 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2279 PKT_INT, GET_32BIT(pktin.body),
2281 logevent("Rejected X11 connect request");
2283 c = smalloc(sizeof(struct ssh_channel));
2285 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
2286 logevent("opening X11 forward connection failed");
2288 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2289 PKT_INT, GET_32BIT(pktin.body),
2292 logevent("opening X11 forward connection succeeded");
2293 c->remoteid = GET_32BIT(pktin.body);
2294 c->localid = alloc_channel_id();
2296 c->type = CHAN_X11; /* identify channel type */
2297 add234(ssh_channels, c);
2298 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2299 PKT_INT, c->remoteid, PKT_INT, c->localid,
2301 logevent("Opened X11 forward channel");
2304 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2305 /* Remote side is trying to open a channel to talk to our
2306 * agent. Give them back a local channel number. */
2308 struct ssh_channel *c;
2310 /* Refuse if agent forwarding is disabled. */
2311 if (!ssh_agentfwd_enabled) {
2312 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2313 PKT_INT, GET_32BIT(pktin.body),
2316 c = smalloc(sizeof(struct ssh_channel));
2317 c->remoteid = GET_32BIT(pktin.body);
2318 c->localid = alloc_channel_id();
2320 c->type = CHAN_AGENT; /* identify channel type */
2321 c->u.a.lensofar = 0;
2322 add234(ssh_channels, c);
2323 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2324 PKT_INT, c->remoteid, PKT_INT, c->localid,
2327 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2328 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2329 /* Remote side closes a channel. */
2330 unsigned i = GET_32BIT(pktin.body);
2331 struct ssh_channel *c;
2332 c = find234(ssh_channels, &i, ssh_channelfind);
2335 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2336 if (!(c->closes & closetype))
2337 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
2338 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2339 logevent("X11 connection closed");
2340 assert(c->u.x11.s != NULL);
2341 x11_close(c->u.x11.s);
2344 c->closes |= closetype;
2345 if (c->closes == 3) {
2346 del234(ssh_channels, c);
2350 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2351 /* Data sent down one of our channels. */
2352 int i = GET_32BIT(pktin.body);
2353 int len = GET_32BIT(pktin.body+4);
2354 unsigned char *p = pktin.body+8;
2355 struct ssh_channel *c;
2356 c = find234(ssh_channels, &i, ssh_channelfind);
2360 x11_send(c->u.x11.s, p, len);
2363 /* Data for an agent message. Buffer it. */
2365 if (c->u.a.lensofar < 4) {
2366 int l = min(4 - c->u.a.lensofar, len);
2367 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2368 p += l; len -= l; c->u.a.lensofar += l;
2370 if (c->u.a.lensofar == 4) {
2371 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
2372 c->u.a.message = smalloc(c->u.a.totallen);
2373 memcpy(c->u.a.message, c->u.a.msglen, 4);
2375 if (c->u.a.lensofar >= 4 && len > 0) {
2376 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2377 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2378 p += l; len -= l; c->u.a.lensofar += l;
2380 if (c->u.a.lensofar == c->u.a.totallen) {
2381 void *reply, *sentreply;
2383 agent_query(c->u.a.message, c->u.a.totallen,
2388 /* Fake SSH_AGENT_FAILURE. */
2389 sentreply = "\0\0\0\1\5";
2392 send_packet(SSH1_MSG_CHANNEL_DATA,
2393 PKT_INT, c->remoteid,
2395 PKT_DATA, sentreply, replylen,
2399 sfree(c->u.a.message);
2400 c->u.a.lensofar = 0;
2406 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2407 /* may be from EXEC_SHELL on some servers */
2408 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2409 /* may be from EXEC_SHELL on some servers
2410 * if no pty is available or in other odd cases. Ignore */
2411 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2412 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2414 bombout(("Strange packet received: type %d", pktin.type));
2419 int len = min(inlen, 512);
2420 send_packet(SSH1_CMSG_STDIN_DATA,
2421 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2432 * Utility routine for decoding comma-separated strings in KEXINIT.
2434 static int in_commasep_string(char *needle, char *haystack, int haylen) {
2435 int needlen = strlen(needle);
2438 * Is it at the start of the string?
2440 if (haylen >= needlen && /* haystack is long enough */
2441 !memcmp(needle, haystack, needlen) && /* initial match */
2442 (haylen == needlen || haystack[needlen] == ',')
2443 /* either , or EOS follows */
2447 * If not, search for the next comma and resume after that.
2448 * If no comma found, terminate.
2450 while (haylen > 0 && *haystack != ',')
2451 haylen--, haystack++;
2454 haylen--, haystack++; /* skip over comma itself */
2459 * SSH2 key creation method.
2461 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
2463 /* First 20 bytes. */
2466 SHA_Bytes(&s, H, 20);
2467 SHA_Bytes(&s, &chr, 1);
2468 SHA_Bytes(&s, sessid, 20);
2469 SHA_Final(&s, keyspace);
2470 /* Next 20 bytes. */
2473 SHA_Bytes(&s, H, 20);
2474 SHA_Bytes(&s, keyspace, 20);
2475 SHA_Final(&s, keyspace+20);
2479 * Handle the SSH2 transport layer.
2481 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2483 static int i, j, len, nbits, pbits;
2485 static Bignum p, g, e, f, K;
2486 static int kex_init_value, kex_reply_value;
2487 static const struct ssh_mac **maclist;
2489 static const struct ssh2_cipher *cscipher_tobe = NULL;
2490 static const struct ssh2_cipher *sccipher_tobe = NULL;
2491 static const struct ssh_mac *csmac_tobe = NULL;
2492 static const struct ssh_mac *scmac_tobe = NULL;
2493 static const struct ssh_compress *cscomp_tobe = NULL;
2494 static const struct ssh_compress *sccomp_tobe = NULL;
2495 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2496 static int hostkeylen, siglen;
2497 static void *hkey; /* actual host key */
2498 static unsigned char exchange_hash[20];
2499 static unsigned char keyspace[40];
2500 static const struct ssh2_ciphers *preferred_cipher;
2501 static const struct ssh_compress *preferred_comp;
2502 static int first_kex;
2509 * Set up the preferred cipher and compression.
2511 if (cfg.cipher == CIPHER_BLOWFISH) {
2512 preferred_cipher = &ssh2_blowfish;
2513 } else if (cfg.cipher == CIPHER_DES) {
2514 logevent("Single DES not supported in SSH2; using 3DES");
2515 preferred_cipher = &ssh2_3des;
2516 } else if (cfg.cipher == CIPHER_3DES) {
2517 preferred_cipher = &ssh2_3des;
2518 } else if (cfg.cipher == CIPHER_AES) {
2519 preferred_cipher = &ssh2_aes;
2521 /* Shouldn't happen, but we do want to initialise to _something_. */
2522 preferred_cipher = &ssh2_3des;
2524 if (cfg.compression)
2525 preferred_comp = &ssh_zlib;
2527 preferred_comp = &ssh_comp_none;
2530 * Be prepared to work around the buggy MAC problem.
2532 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
2533 maclist = buggymacs, nmacs = lenof(buggymacs);
2535 maclist = macs, nmacs = lenof(macs);
2539 * Construct and send our key exchange packet.
2541 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2542 for (i = 0; i < 16; i++)
2543 ssh2_pkt_addbyte((unsigned char)random_byte());
2544 /* List key exchange algorithms. */
2545 ssh2_pkt_addstring_start();
2546 for (i = 0; i < lenof(kex_algs); i++) {
2547 ssh2_pkt_addstring_str(kex_algs[i]->name);
2548 if (i < lenof(kex_algs)-1)
2549 ssh2_pkt_addstring_str(",");
2551 /* List server host key algorithms. */
2552 ssh2_pkt_addstring_start();
2553 for (i = 0; i < lenof(hostkey_algs); i++) {
2554 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2555 if (i < lenof(hostkey_algs)-1)
2556 ssh2_pkt_addstring_str(",");
2558 /* List client->server encryption algorithms. */
2559 ssh2_pkt_addstring_start();
2560 for (i = 0; i < lenof(ciphers)+1; i++) {
2561 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2562 for (j = 0; j < c->nciphers; j++) {
2563 ssh2_pkt_addstring_str(c->list[j]->name);
2564 if (i < lenof(ciphers) || j < c->nciphers-1)
2565 ssh2_pkt_addstring_str(",");
2568 /* List server->client encryption algorithms. */
2569 ssh2_pkt_addstring_start();
2570 for (i = 0; i < lenof(ciphers)+1; i++) {
2571 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2572 for (j = 0; j < c->nciphers; j++) {
2573 ssh2_pkt_addstring_str(c->list[j]->name);
2574 if (i < lenof(ciphers) || j < c->nciphers-1)
2575 ssh2_pkt_addstring_str(",");
2578 /* List client->server MAC algorithms. */
2579 ssh2_pkt_addstring_start();
2580 for (i = 0; i < nmacs; i++) {
2581 ssh2_pkt_addstring_str(maclist[i]->name);
2583 ssh2_pkt_addstring_str(",");
2585 /* List server->client MAC algorithms. */
2586 ssh2_pkt_addstring_start();
2587 for (i = 0; i < nmacs; i++) {
2588 ssh2_pkt_addstring_str(maclist[i]->name);
2590 ssh2_pkt_addstring_str(",");
2592 /* List client->server compression algorithms. */
2593 ssh2_pkt_addstring_start();
2594 for (i = 0; i < lenof(compressions)+1; i++) {
2595 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2596 ssh2_pkt_addstring_str(c->name);
2597 if (i < lenof(compressions))
2598 ssh2_pkt_addstring_str(",");
2600 /* List server->client compression algorithms. */
2601 ssh2_pkt_addstring_start();
2602 for (i = 0; i < lenof(compressions)+1; i++) {
2603 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2604 ssh2_pkt_addstring_str(c->name);
2605 if (i < lenof(compressions))
2606 ssh2_pkt_addstring_str(",");
2608 /* List client->server languages. Empty list. */
2609 ssh2_pkt_addstring_start();
2610 /* List server->client languages. Empty list. */
2611 ssh2_pkt_addstring_start();
2612 /* First KEX packet does _not_ follow, because we're not that brave. */
2613 ssh2_pkt_addbool(FALSE);
2615 ssh2_pkt_adduint32(0);
2617 exhash = exhashbase;
2618 sha_string(&exhash, pktout.data+5, pktout.length-5);
2622 if (!ispkt) crWaitUntil(ispkt);
2623 sha_string(&exhash, pktin.data+5, pktin.length-5);
2626 * Now examine the other side's KEXINIT to see what we're up
2629 if (pktin.type != SSH2_MSG_KEXINIT) {
2630 bombout(("expected key exchange packet from server"));
2633 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2634 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2635 pktin.savedpos += 16; /* skip garbage cookie */
2636 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2637 for (i = 0; i < lenof(kex_algs); i++) {
2638 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2643 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2644 for (i = 0; i < lenof(hostkey_algs); i++) {
2645 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2646 hostkey = hostkey_algs[i];
2650 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2651 for (i = 0; i < lenof(ciphers)+1; i++) {
2652 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2653 for (j = 0; j < c->nciphers; j++) {
2654 if (in_commasep_string(c->list[j]->name, str, len)) {
2655 cscipher_tobe = c->list[j];
2662 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2663 for (i = 0; i < lenof(ciphers)+1; i++) {
2664 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2665 for (j = 0; j < c->nciphers; j++) {
2666 if (in_commasep_string(c->list[j]->name, str, len)) {
2667 sccipher_tobe = c->list[j];
2674 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2675 for (i = 0; i < nmacs; i++) {
2676 if (in_commasep_string(maclist[i]->name, str, len)) {
2677 csmac_tobe = maclist[i];
2681 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2682 for (i = 0; i < nmacs; i++) {
2683 if (in_commasep_string(maclist[i]->name, str, len)) {
2684 scmac_tobe = maclist[i];
2688 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2689 for (i = 0; i < lenof(compressions)+1; i++) {
2690 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2691 if (in_commasep_string(c->name, str, len)) {
2696 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2697 for (i = 0; i < lenof(compressions)+1; i++) {
2698 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2699 if (in_commasep_string(c->name, str, len)) {
2706 * Work out the number of bits of key we will need from the key
2707 * exchange. We start with the maximum key length of either
2713 csbits = cscipher_tobe->keylen;
2714 scbits = sccipher_tobe->keylen;
2715 nbits = (csbits > scbits ? csbits : scbits);
2717 /* The keys only have 160-bit entropy, since they're based on
2718 * a SHA-1 hash. So cap the key size at 160 bits. */
2719 if (nbits > 160) nbits = 160;
2722 * If we're doing Diffie-Hellman group exchange, start by
2723 * requesting a group.
2725 if (kex == &ssh_diffiehellman_gex) {
2726 logevent("Doing Diffie-Hellman group exchange");
2728 * Work out how big a DH group we will need to allow that
2731 pbits = 512 << ((nbits-1) / 64);
2732 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2733 ssh2_pkt_adduint32(pbits);
2737 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2738 bombout(("expected key exchange group packet from server"));
2741 p = ssh2_pkt_getmp();
2742 g = ssh2_pkt_getmp();
2743 dh_setup_group(p, g);
2744 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2745 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2748 kex_init_value = SSH2_MSG_KEXDH_INIT;
2749 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
2752 logevent("Doing Diffie-Hellman key exchange");
2754 * Now generate and send e for Diffie-Hellman.
2756 e = dh_create_e(nbits*2);
2757 ssh2_pkt_init(kex_init_value);
2762 if (pktin.type != kex_reply_value) {
2763 bombout(("expected key exchange reply packet from server"));
2766 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2767 f = ssh2_pkt_getmp();
2768 ssh2_pkt_getstring(&sigdata, &siglen);
2772 sha_string(&exhash, hostkeydata, hostkeylen);
2773 if (kex == &ssh_diffiehellman_gex) {
2774 sha_uint32(&exhash, pbits);
2775 sha_mpint(&exhash, p);
2776 sha_mpint(&exhash, g);
2778 sha_mpint(&exhash, e);
2779 sha_mpint(&exhash, f);
2780 sha_mpint(&exhash, K);
2781 SHA_Final(&exhash, exchange_hash);
2786 debug(("Exchange hash is:\r\n"));
2787 for (i = 0; i < 20; i++)
2788 debug((" %02x", exchange_hash[i]));
2792 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2793 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2794 bombout(("Server failed host key check"));
2799 * Expect SSH2_MSG_NEWKEYS from server.
2802 if (pktin.type != SSH2_MSG_NEWKEYS) {
2803 bombout(("expected new-keys packet from server"));
2808 * Authenticate remote host: verify host key. (We've already
2809 * checked the signature of the exchange hash.)
2811 keystr = hostkey->fmtkey(hkey);
2812 fingerprint = hostkey->fingerprint(hkey);
2813 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2814 keystr, fingerprint);
2815 if (first_kex) { /* don't bother logging this in rekeys */
2816 logevent("Host key fingerprint is:");
2817 logevent(fingerprint);
2821 hostkey->freekey(hkey);
2824 * Send SSH2_MSG_NEWKEYS.
2826 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2830 * Create and initialise session keys.
2832 cscipher = cscipher_tobe;
2833 sccipher = sccipher_tobe;
2836 cscomp = cscomp_tobe;
2837 sccomp = sccomp_tobe;
2838 cscomp->compress_init();
2839 sccomp->decompress_init();
2841 * Set IVs after keys. Here we use the exchange hash from the
2842 * _first_ key exchange.
2845 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
2846 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
2847 cscipher->setcskey(keyspace);
2848 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
2849 sccipher->setsckey(keyspace);
2850 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
2851 cscipher->setcsiv(keyspace);
2852 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
2853 sccipher->setsciv(keyspace);
2854 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
2855 csmac->setcskey(keyspace);
2856 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
2857 scmac->setsckey(keyspace);
2860 * If this is the first key exchange phase, we must pass the
2861 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2862 * wants to see it but because it will need time to initialise
2863 * itself before it sees an actual packet. In subsequent key
2864 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2865 * it would only confuse the layer above.
2873 * Now we're encrypting. Begin returning 1 to the protocol main
2874 * function so that other things can run on top of the
2875 * transport. If we ever see a KEXINIT, we must go back to the
2878 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
2881 logevent("Server initiated key re-exchange");
2882 goto begin_key_exchange;
2888 * Add data to an SSH2 channel output buffer.
2890 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2891 if (c->v2.outbufsize <
2892 c->v2.outbuflen + len) {
2894 c->v2.outbuflen + len + 1024;
2895 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2898 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2900 c->v2.outbuflen += len;
2904 * Attempt to send data on an SSH2 channel.
2906 static void ssh2_try_send(struct ssh_channel *c) {
2907 while (c->v2.remwindow > 0 &&
2908 c->v2.outbuflen > 0) {
2909 unsigned len = c->v2.remwindow;
2910 if (len > c->v2.outbuflen)
2911 len = c->v2.outbuflen;
2912 if (len > c->v2.remmaxpkt)
2913 len = c->v2.remmaxpkt;
2914 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2915 ssh2_pkt_adduint32(c->remoteid);
2916 ssh2_pkt_addstring_start();
2917 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2919 c->v2.outbuflen -= len;
2920 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2922 c->v2.remwindow -= len;
2927 * Handle the SSH2 userauth and connection layers.
2929 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2931 static unsigned long remote_winsize;
2932 static unsigned long remote_maxpkt;
2934 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD
2938 AUTH_TYPE_PUBLICKEY,
2939 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
2940 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
2943 static int gotit, need_pw, can_pubkey, can_passwd;
2944 static int tried_pubkey_config, tried_agent;
2945 static int we_are_in;
2946 static char username[100];
2947 static char pwprompt[200];
2948 static char password[100];
2953 * Request userauth protocol, and await a response to it.
2955 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2956 ssh2_pkt_addstring("ssh-userauth");
2958 crWaitUntilV(ispkt);
2959 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2960 bombout(("Server refused user authentication protocol"));
2965 * We repeat this whole loop, including the username prompt,
2966 * until we manage a successful authentication. If the user
2967 * types the wrong _password_, they are sent back to the
2968 * beginning to try another username. (If they specify a
2969 * username in the config, they are never asked, even if they
2970 * do give a wrong password.)
2972 * I think this best serves the needs of
2974 * - the people who have no configuration, no keys, and just
2975 * want to try repeated (username,password) pairs until they
2976 * type both correctly
2978 * - people who have keys and configuration but occasionally
2979 * need to fall back to passwords
2981 * - people with a key held in Pageant, who might not have
2982 * logged in to a particular machine before; so they want to
2983 * type a username, and then _either_ their key will be
2984 * accepted, _or_ they will type a password. If they mistype
2985 * the username they will want to be able to get back and
2996 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2998 if (!ssh_get_line("login as: ",
2999 username, sizeof(username), FALSE)) {
3001 * get_line failed to get a username.
3004 logevent("No username provided. Abandoning session.");
3005 ssh_state = SSH_STATE_CLOSED;
3009 c_write_str("login as: ");
3012 crWaitUntilV(!ispkt);
3013 while (inlen--) switch (c = *in++) {
3020 c_write_str("\b \b");
3026 c_write_str("\b \b");
3035 if (((c >= ' ' && c <= '~') ||
3036 ((unsigned char)c >= 160)) && pos < 40) {
3037 username[pos++] = c;
3044 c_write_str("\r\n");
3045 username[strcspn(username, "\n\r")] = '\0';
3048 strncpy(username, cfg.username, 99);
3049 username[99] = '\0';
3050 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3051 sprintf(stuff, "Using username \"%s\".\r\n", username);
3057 * Send an authentication request using method "none": (a)
3058 * just in case it succeeds, and (b) so that we know what
3059 * authentication methods we can usefully try next.
3061 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3062 ssh2_pkt_addstring(username);
3063 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3064 ssh2_pkt_addstring("none"); /* method */
3066 type = AUTH_TYPE_NONE;
3070 tried_pubkey_config = FALSE;
3071 tried_agent = FALSE;
3075 * Wait for the result of the last authentication request.
3078 crWaitUntilV(ispkt);
3079 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3083 * Don't show the banner if we're operating in
3084 * non-verbose non-interactive mode. (It's probably
3085 * a script, which means nobody will read the
3086 * banner _anyway_, and moreover the printing of
3087 * the banner will screw up processing on the
3088 * output of (say) plink.)
3090 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3091 ssh2_pkt_getstring(&banner, &size);
3093 c_write_untrusted(banner, size);
3095 crWaitUntilV(ispkt);
3097 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3098 logevent("Access granted");
3103 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3104 bombout(("Strange packet received during authentication: type %d",
3112 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3113 * we can look at the string in it and know what we can
3114 * helpfully try next.
3119 ssh2_pkt_getstring(&methods, &methlen);
3120 if (!ssh2_pkt_getbool()) {
3122 * We have received an unequivocal Access
3123 * Denied. This can translate to a variety of
3126 * - if we'd just tried "none" authentication,
3127 * it's not worth printing anything at all
3129 * - if we'd just tried a public key _offer_,
3130 * the message should be "Server refused our
3131 * key" (or no message at all if the key
3132 * came from Pageant)
3134 * - if we'd just tried anything else, the
3135 * message really should be "Access denied".
3137 * Additionally, if we'd just tried password
3138 * authentication, we should break out of this
3139 * whole loop so as to go back to the username
3142 if (type == AUTH_TYPE_NONE) {
3144 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3145 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3146 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3147 c_write_str("Server refused our key\r\n");
3148 logevent("Server refused public key");
3150 c_write_str("Access denied\r\n");
3151 logevent("Access denied");
3152 if (type == AUTH_TYPE_PASSWORD) {
3158 c_write_str("Further authentication required\r\n");
3159 logevent("Further authentication required");
3162 can_pubkey = in_commasep_string("publickey", methods, methlen);
3163 can_passwd = in_commasep_string("password", methods, methlen);
3168 if (!method && can_pubkey && agent_exists && !tried_agent) {
3170 * Attempt public-key authentication using Pageant.
3172 static unsigned char request[5], *response, *p;
3173 static int responselen;
3174 static int i, nkeys;
3175 static int authed = FALSE;
3180 logevent("Pageant is running. Requesting keys.");
3182 /* Request the keys held by the agent. */
3183 PUT_32BIT(request, 1);
3184 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3185 agent_query(request, 5, &r, &responselen);
3186 response = (unsigned char *)r;
3187 if (response && responselen >= 5 &&
3188 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3190 nkeys = GET_32BIT(p); p += 4;
3191 { char buf[64]; sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3193 for (i = 0; i < nkeys; i++) {
3194 static char *pkblob, *alg, *commentp;
3195 static int pklen, alglen, commentlen;
3196 static int siglen, retlen, len;
3197 static char *q, *agentreq, *ret;
3199 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
3201 pklen = GET_32BIT(p); p += 4;
3202 pkblob = p; p += pklen;
3203 alglen = GET_32BIT(pkblob);
3205 commentlen = GET_32BIT(p); p += 4;
3206 commentp = p; p += commentlen;
3207 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3208 ssh2_pkt_addstring(username);
3209 ssh2_pkt_addstring("ssh-connection");/* service requested */
3210 ssh2_pkt_addstring("publickey");/* method */
3211 ssh2_pkt_addbool(FALSE); /* no signature included */
3212 ssh2_pkt_addstring_start();
3213 ssh2_pkt_addstring_data(alg, alglen);
3214 ssh2_pkt_addstring_start();
3215 ssh2_pkt_addstring_data(pkblob, pklen);
3218 crWaitUntilV(ispkt);
3219 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3220 logevent("Key refused");
3224 if (flags & FLAG_VERBOSE) {
3225 c_write_str("Authenticating with public key \"");
3226 c_write(commentp, commentlen);
3227 c_write_str("\" from agent\r\n");
3231 * Server is willing to accept the key.
3232 * Construct a SIGN_REQUEST.
3234 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3235 ssh2_pkt_addstring(username);
3236 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3237 ssh2_pkt_addstring("publickey"); /* method */
3238 ssh2_pkt_addbool(TRUE);
3239 ssh2_pkt_addstring_start();
3240 ssh2_pkt_addstring_data(alg, alglen);
3241 ssh2_pkt_addstring_start();
3242 ssh2_pkt_addstring_data(pkblob, pklen);
3244 siglen = pktout.length - 5 + 4 + 20;
3245 len = 1; /* message type */
3246 len += 4 + pklen; /* key blob */
3247 len += 4 + siglen; /* data to sign */
3248 len += 4; /* flags */
3249 agentreq = smalloc(4 + len);
3250 PUT_32BIT(agentreq, len);
3252 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3253 PUT_32BIT(q, pklen); q += 4;
3254 memcpy(q, pkblob, pklen); q += pklen;
3255 PUT_32BIT(q, siglen); q += 4;
3256 /* Now the data to be signed... */
3257 PUT_32BIT(q, 20); q += 4;
3258 memcpy(q, ssh2_session_id, 20); q += 20;
3259 memcpy(q, pktout.data+5, pktout.length-5);
3260 q += pktout.length-5;
3261 /* And finally the (zero) flags word. */
3263 agent_query(agentreq, len+4, &ret, &retlen);
3266 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3267 logevent("Sending Pageant's response");
3268 ssh2_pkt_addstring_start();
3269 ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5));
3274 logevent("Pageant failed to answer challenge");
3284 if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) {
3285 unsigned char *pub_blob;
3286 char *algorithm, *comment;
3289 tried_pubkey_config = TRUE;
3292 * Try the public key supplied in the configuration.
3294 * First, offer the public blob to see if the server is
3295 * willing to accept it.
3297 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3300 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3301 ssh2_pkt_addstring(username);
3302 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3303 ssh2_pkt_addstring("publickey");/* method */
3304 ssh2_pkt_addbool(FALSE); /* no signature included */
3305 ssh2_pkt_addstring(algorithm);
3306 ssh2_pkt_addstring_start();
3307 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3309 logevent("Offered public key"); /* FIXME */
3311 crWaitUntilV(ispkt);
3312 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3314 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3315 continue; /* key refused; give up on it */
3318 logevent("Offer of public key accepted");
3320 * Actually attempt a serious authentication using
3323 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3324 sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment);
3329 c_write_str("Authenticating with public key \"");
3330 c_write_str(comment);
3331 c_write_str("\"\r\n");
3332 method = AUTH_PUBLICKEY_FILE;
3336 if (!method && can_passwd) {
3337 method = AUTH_PASSWORD;
3338 sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost);
3344 if (!ssh_get_line(pwprompt, password,
3345 sizeof(password), TRUE)) {
3347 * get_line failed to get a password (for
3348 * example because one was supplied on the
3349 * command line which has already failed to
3352 logevent("No more passwords to try");
3353 ssh_state = SSH_STATE_CLOSED;
3360 c_write_str(pwprompt);
3365 crWaitUntilV(!ispkt);
3366 while (inlen--) switch (c = *in++) {
3383 if (((c >= ' ' && c <= '~') ||
3384 ((unsigned char)c >= 160)) && pos < 40)
3385 password[pos++] = c;
3389 c_write_str("\r\n");
3393 if (method == AUTH_PUBLICKEY_FILE) {
3395 * We have our passphrase. Now try the actual authentication.
3397 struct ssh2_userkey *key;
3399 key = ssh2_load_userkey(cfg.keyfile, password);
3400 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3401 if (key == SSH2_WRONG_PASSPHRASE) {
3402 c_write_str("Wrong passphrase\r\n");
3403 tried_pubkey_config = FALSE;
3405 c_write_str("Unable to load private key\r\n");
3406 tried_pubkey_config = TRUE;
3408 /* Send a spurious AUTH_NONE to return to the top. */
3409 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3410 ssh2_pkt_addstring(username);
3411 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3412 ssh2_pkt_addstring("none"); /* method */
3414 type = AUTH_TYPE_NONE;
3416 unsigned char *blob, *sigdata;
3417 int blob_len, sigdata_len;
3420 * We have loaded the private key and the server
3421 * has announced that it's willing to accept it.
3422 * Hallelujah. Generate a signature and send it.
3424 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3425 ssh2_pkt_addstring(username);
3426 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3427 ssh2_pkt_addstring("publickey"); /* method */
3428 ssh2_pkt_addbool(TRUE);
3429 ssh2_pkt_addstring(key->alg->name);
3430 blob = key->alg->public_blob(key->data, &blob_len);
3431 ssh2_pkt_addstring_start();
3432 ssh2_pkt_addstring_data(blob, blob_len);
3436 * The data to be signed is:
3440 * followed by everything so far placed in the
3443 sigdata_len = pktout.length - 5 + 4 + 20;
3444 sigdata = smalloc(sigdata_len);
3445 PUT_32BIT(sigdata, 20);
3446 memcpy(sigdata+4, ssh2_session_id, 20);
3447 memcpy(sigdata+24, pktout.data+5, pktout.length-5);
3448 blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len);
3449 ssh2_pkt_addstring_start();
3450 ssh2_pkt_addstring_data(blob, blob_len);
3455 type = AUTH_TYPE_PUBLICKEY;
3457 } else if (method == AUTH_PASSWORD) {
3459 * We send the password packet lumped tightly together with
3460 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3461 * string long enough to make the total length of the two
3462 * packets constant. This should ensure that a passive
3463 * listener doing traffic analyis can't work out the length
3466 * For this to work, we need an assumption about the
3467 * maximum length of the password packet. I think 256 is
3468 * pretty conservative. Anyone using a password longer than
3469 * that probably doesn't have much to worry about from
3470 * people who find out how long their password is!
3472 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3473 ssh2_pkt_addstring(username);
3474 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3475 ssh2_pkt_addstring("password");
3476 ssh2_pkt_addbool(FALSE);
3477 ssh2_pkt_addstring(password);
3480 * We'll include a string that's an exact multiple of the
3481 * cipher block size. If the cipher is NULL for some
3482 * reason, we don't do this trick at all because we gain
3488 stringlen = (256 - deferred_len);
3489 stringlen += cscipher->blksize - 1;
3490 stringlen -= (stringlen % cscipher->blksize);
3493 * Temporarily disable actual compression,
3494 * so we can guarantee to get this string
3495 * exactly the length we want it. The
3496 * compression-disabling routine should
3497 * return an integer indicating how many
3498 * bytes we should adjust our string length
3501 stringlen -= cscomp->disable_compression();
3503 ssh2_pkt_init(SSH2_MSG_IGNORE);
3504 ssh2_pkt_addstring_start();
3505 for (i = 0; i < stringlen; i++) {
3506 char c = (char)random_byte();
3507 ssh2_pkt_addstring_data(&c, 1);
3511 ssh_pkt_defersend();
3512 logevent("Sent password");
3513 type = AUTH_TYPE_PASSWORD;
3515 c_write_str("No supported authentication methods left to try!\r\n");
3516 logevent("No supported authentications offered. Disconnecting");
3517 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3518 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3519 ssh2_pkt_addstring("No supported authentication methods available");
3520 ssh2_pkt_addstring("en"); /* language tag */
3522 ssh_state = SSH_STATE_CLOSED;
3526 } while (!we_are_in);
3529 * Now we're authenticated for the connection protocol. The
3530 * connection protocol will automatically have started at this
3531 * point; there's no need to send SERVICE_REQUEST.
3535 * So now create a channel with a session in it.
3537 ssh_channels = newtree234(ssh_channelcmp);
3538 mainchan = smalloc(sizeof(struct ssh_channel));
3539 mainchan->localid = alloc_channel_id();
3540 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3541 ssh2_pkt_addstring("session");
3542 ssh2_pkt_adduint32(mainchan->localid);
3543 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3544 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3546 crWaitUntilV(ispkt);
3547 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
3548 bombout(("Server refused to open a session"));
3550 /* FIXME: error data comes back in FAILURE packet */
3552 if (ssh2_pkt_getuint32() != mainchan->localid) {
3553 bombout(("Server's channel confirmation cited wrong channel"));
3556 mainchan->remoteid = ssh2_pkt_getuint32();
3557 mainchan->type = CHAN_MAINSESSION;
3558 mainchan->closes = 0;
3559 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3560 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3561 mainchan->v2.outbuffer = NULL;
3562 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3563 add234(ssh_channels, mainchan);
3564 logevent("Opened channel for session");
3567 * Potentially enable X11 forwarding.
3569 if (cfg.x11_forward) {
3570 char proto[20], data[64];
3571 logevent("Requesting X11 forwarding");
3572 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3573 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3574 ssh2_pkt_adduint32(mainchan->remoteid);
3575 ssh2_pkt_addstring("x11-req");
3576 ssh2_pkt_addbool(1); /* want reply */
3577 ssh2_pkt_addbool(0); /* many connections */
3578 ssh2_pkt_addstring(proto);
3579 ssh2_pkt_addstring(data);
3580 ssh2_pkt_adduint32(0); /* screen number */
3584 crWaitUntilV(ispkt);
3585 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3586 unsigned i = ssh2_pkt_getuint32();
3587 struct ssh_channel *c;
3588 c = find234(ssh_channels, &i, ssh_channelfind);
3590 continue; /* nonexistent channel */
3591 c->v2.remwindow += ssh2_pkt_getuint32();
3593 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3595 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3596 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3597 bombout(("Server got confused by X11 forwarding request"));
3600 logevent("X11 forwarding refused");
3602 logevent("X11 forwarding enabled");
3603 ssh_X11_fwd_enabled = TRUE;
3608 * Potentially enable agent forwarding.
3610 if (cfg.agentfwd && agent_exists()) {
3611 logevent("Requesting OpenSSH-style agent forwarding");
3612 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3613 ssh2_pkt_adduint32(mainchan->remoteid);
3614 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3615 ssh2_pkt_addbool(1); /* want reply */
3619 crWaitUntilV(ispkt);
3620 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3621 unsigned i = ssh2_pkt_getuint32();
3622 struct ssh_channel *c;
3623 c = find234(ssh_channels, &i, ssh_channelfind);
3625 continue; /* nonexistent channel */
3626 c->v2.remwindow += ssh2_pkt_getuint32();
3628 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3630 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3631 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3632 bombout(("Server got confused by agent forwarding request"));
3635 logevent("Agent forwarding refused");
3637 logevent("Agent forwarding enabled");
3638 ssh_agentfwd_enabled = TRUE;
3643 * Now allocate a pty for the session.
3646 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3647 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3648 ssh2_pkt_addstring("pty-req");
3649 ssh2_pkt_addbool(1); /* want reply */
3650 ssh2_pkt_addstring(cfg.termtype);
3651 ssh2_pkt_adduint32(cols);
3652 ssh2_pkt_adduint32(rows);
3653 ssh2_pkt_adduint32(0); /* pixel width */
3654 ssh2_pkt_adduint32(0); /* pixel height */
3655 ssh2_pkt_addstring_start();
3656 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3658 ssh_state = SSH_STATE_INTERMED;
3661 crWaitUntilV(ispkt);
3662 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3663 unsigned i = ssh2_pkt_getuint32();
3664 struct ssh_channel *c;
3665 c = find234(ssh_channels, &i, ssh_channelfind);
3667 continue; /* nonexistent channel */
3668 c->v2.remwindow += ssh2_pkt_getuint32();
3670 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3672 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3673 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3674 bombout(("Server got confused by pty request"));
3677 c_write_str("Server refused to allocate pty\r\n");
3678 ssh_editing = ssh_echoing = 1;
3680 logevent("Allocated pty");
3683 ssh_editing = ssh_echoing = 1;
3687 * Start a shell or a remote command.
3689 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3690 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3691 if (cfg.ssh_subsys) {
3692 ssh2_pkt_addstring("subsystem");
3693 ssh2_pkt_addbool(1); /* want reply */
3694 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
3695 } else if (*cfg.remote_cmd_ptr) {
3696 ssh2_pkt_addstring("exec");
3697 ssh2_pkt_addbool(1); /* want reply */
3698 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
3700 ssh2_pkt_addstring("shell");
3701 ssh2_pkt_addbool(1); /* want reply */
3705 crWaitUntilV(ispkt);
3706 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3707 unsigned i = ssh2_pkt_getuint32();
3708 struct ssh_channel *c;
3709 c = find234(ssh_channels, &i, ssh_channelfind);
3711 continue; /* nonexistent channel */
3712 c->v2.remwindow += ssh2_pkt_getuint32();
3714 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3715 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3716 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3717 bombout(("Server got confused by shell/command request"));
3720 bombout(("Server refused to start a shell/command"));
3723 logevent("Started a shell/command");
3726 ssh_state = SSH_STATE_SESSION;
3730 ssh_special(TS_EOF);
3735 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
3738 static int try_send;
3742 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3743 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3746 unsigned i = ssh2_pkt_getuint32();
3747 struct ssh_channel *c;
3748 c = find234(ssh_channels, &i, ssh_channelfind);
3750 continue; /* nonexistent channel */
3751 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3752 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3753 continue; /* extended but not stderr */
3754 ssh2_pkt_getstring(&data, &length);
3757 case CHAN_MAINSESSION:
3758 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
3762 x11_send(c->u.x11.s, data, length);
3765 while (length > 0) {
3766 if (c->u.a.lensofar < 4) {
3767 int l = min(4 - c->u.a.lensofar, length);
3768 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
3769 data += l; length -= l; c->u.a.lensofar += l;
3771 if (c->u.a.lensofar == 4) {
3772 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
3773 c->u.a.message = smalloc(c->u.a.totallen);
3774 memcpy(c->u.a.message, c->u.a.msglen, 4);
3776 if (c->u.a.lensofar >= 4 && length > 0) {
3777 int l = min(c->u.a.totallen - c->u.a.lensofar,
3779 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
3780 data += l; length -= l; c->u.a.lensofar += l;
3782 if (c->u.a.lensofar == c->u.a.totallen) {
3783 void *reply, *sentreply;
3785 agent_query(c->u.a.message, c->u.a.totallen,
3790 /* Fake SSH_AGENT_FAILURE. */
3791 sentreply = "\0\0\0\1\5";
3794 ssh2_add_channel_data(c, sentreply, replylen);
3798 sfree(c->u.a.message);
3799 c->u.a.lensofar = 0;
3805 * Enlarge the window again at the remote
3806 * side, just in case it ever runs down and
3807 * they fail to send us any more data.
3809 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3810 ssh2_pkt_adduint32(c->remoteid);
3811 ssh2_pkt_adduint32(length);
3814 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
3815 ssh_state = SSH_STATE_CLOSED;
3816 logevent("Received disconnect message");
3818 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
3819 continue; /* exit status et al; ignore (FIXME?) */
3820 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
3821 unsigned i = ssh2_pkt_getuint32();
3822 struct ssh_channel *c;
3824 c = find234(ssh_channels, &i, ssh_channelfind);
3826 continue; /* nonexistent channel */
3828 if (c->type == CHAN_X11) {
3830 * Remote EOF on an X11 channel means we should
3831 * wrap up and close the channel ourselves.
3833 x11_close(c->u.x11.s);
3835 } else if (c->type == CHAN_AGENT) {
3838 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
3839 unsigned i = ssh2_pkt_getuint32();
3840 struct ssh_channel *c;
3842 c = find234(ssh_channels, &i, ssh_channelfind);
3844 continue; /* nonexistent channel */
3845 if (c->closes == 0) {
3846 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3847 ssh2_pkt_adduint32(c->remoteid);
3850 /* Do pre-close processing on the channel. */
3852 case CHAN_MAINSESSION:
3853 break; /* nothing to see here, move along */
3859 del234(ssh_channels, c);
3860 sfree(c->v2.outbuffer);
3864 * See if that was the last channel left open.
3866 if (count234(ssh_channels) == 0) {
3867 logevent("All channels closed. Disconnecting");
3868 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3869 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3870 ssh2_pkt_addstring("All open channels closed");
3871 ssh2_pkt_addstring("en"); /* language tag */
3873 ssh_state = SSH_STATE_CLOSED;
3876 continue; /* remote sends close; ignore (FIXME) */
3877 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3878 unsigned i = ssh2_pkt_getuint32();
3879 struct ssh_channel *c;
3880 c = find234(ssh_channels, &i, ssh_channelfind);
3882 continue; /* nonexistent channel */
3883 c->v2.remwindow += ssh2_pkt_getuint32();
3885 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3889 struct ssh_channel *c;
3890 ssh2_pkt_getstring(&type, &typelen);
3891 c = smalloc(sizeof(struct ssh_channel));
3893 if (typelen == 3 && !memcmp(type, "x11", 3)) {
3894 if (!ssh_X11_fwd_enabled)
3895 error = "X11 forwarding is not enabled";
3896 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
3897 error = "Unable to open an X11 connection";
3901 } else if (typelen == 22 &&
3902 !memcmp(type, "auth-agent@openssh.com", 3)) {
3903 if (!ssh_agentfwd_enabled)
3904 error = "Agent forwarding is not enabled";
3906 c->type = CHAN_AGENT; /* identify channel type */
3907 c->u.a.lensofar = 0;
3910 error = "Unsupported channel type requested";
3913 c->remoteid = ssh2_pkt_getuint32();
3915 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3916 ssh2_pkt_adduint32(c->remoteid);
3917 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3918 ssh2_pkt_addstring(error);
3919 ssh2_pkt_addstring("en"); /* language tag */
3923 struct ssh_channel *d;
3926 c->localid = alloc_channel_id();
3928 c->v2.remwindow = ssh2_pkt_getuint32();
3929 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3930 c->v2.outbuffer = NULL;
3931 c->v2.outbuflen = c->v2.outbufsize = 0;
3932 add234(ssh_channels, c);
3933 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3934 ssh2_pkt_adduint32(c->remoteid);
3935 ssh2_pkt_adduint32(c->localid);
3936 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3937 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3941 bombout(("Strange packet received: type %d", pktin.type));
3946 * We have spare data. Add it to the channel buffer.
3948 ssh2_add_channel_data(mainchan, in, inlen);
3953 struct ssh_channel *c;
3955 * Try to send data on all channels if we can.
3957 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
3966 * Handle the top-level SSH2 protocol.
3968 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3970 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3972 do_ssh2_authconn(in, inlen, ispkt);
3976 * Called to set up the connection.
3978 * Returns an error message, or NULL on success.
3980 static char *ssh_init (char *host, int port, char **realhost) {
3984 if(crypto_startup() == 0)
3985 return "Microsoft high encryption pack not installed!";
3992 p = connect_to_host(host, port, realhost);
4000 * Called to send data down the Telnet connection.
4002 static void ssh_send (char *buf, int len) {
4003 if (s == NULL || ssh_protocol == NULL)
4006 ssh_protocol(buf, len, 0);
4010 * Called to set the size of the window from SSH's POV.
4012 static void ssh_size(void) {
4013 switch (ssh_state) {
4014 case SSH_STATE_BEFORE_SIZE:
4015 case SSH_STATE_PREPACKET:
4016 case SSH_STATE_CLOSED:
4017 break; /* do nothing */
4018 case SSH_STATE_INTERMED:
4019 size_needed = TRUE; /* buffer for later */
4021 case SSH_STATE_SESSION:
4023 if (ssh_version == 1) {
4024 send_packet(SSH1_CMSG_WINDOW_SIZE,
4025 PKT_INT, rows, PKT_INT, cols,
4026 PKT_INT, 0, PKT_INT, 0, PKT_END);
4028 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4029 ssh2_pkt_adduint32(mainchan->remoteid);
4030 ssh2_pkt_addstring("window-change");
4031 ssh2_pkt_addbool(0);
4032 ssh2_pkt_adduint32(cols);
4033 ssh2_pkt_adduint32(rows);
4034 ssh2_pkt_adduint32(0);
4035 ssh2_pkt_adduint32(0);
4044 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4045 * can send an EOF and collect resulting output (e.g. `plink
4048 static void ssh_special (Telnet_Special code) {
4049 if (code == TS_EOF) {
4050 if (ssh_state != SSH_STATE_SESSION) {
4052 * Buffer the EOF in case we are pre-SESSION, so we can
4053 * send it as soon as we reach SESSION.
4059 if (ssh_version == 1) {
4060 send_packet(SSH1_CMSG_EOF, PKT_END);
4062 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4063 ssh2_pkt_adduint32(mainchan->remoteid);
4066 logevent("Sent EOF message");
4067 } else if (code == TS_PING) {
4068 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
4070 if (ssh_version == 1) {
4071 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
4073 ssh2_pkt_init(SSH2_MSG_IGNORE);
4074 ssh2_pkt_addstring_start();
4082 static Socket ssh_socket(void) { return s; }
4084 static int ssh_sendok(void) { return ssh_send_ok; }
4086 static int ssh_ldisc(int option) {
4087 if (option == LD_ECHO) return ssh_echoing;
4088 if (option == LD_EDIT) return ssh_editing;
4092 Backend ssh_backend = {