18 /* uncomment this for packet level debugging */
19 /* #define DUMP_PACKETS */
21 #define logevent(s) { logevent(s); \
22 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
23 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
25 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
26 (s ? sk_close(s), s = NULL : 0), \
27 connection_fatal msg )
29 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
30 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
31 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
32 #define SSH1_CMSG_USER 4 /* 0x4 */
33 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
34 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
35 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
36 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
37 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
38 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
39 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
40 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
41 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
42 #define SSH1_SMSG_FAILURE 15 /* 0xf */
43 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
44 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
45 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
46 #define SSH1_CMSG_EOF 19 /* 0x13 */
47 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
48 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
49 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
50 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
51 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
52 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
53 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
54 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
55 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
56 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
57 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
58 #define SSH1_MSG_IGNORE 32 /* 0x20 */
59 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
60 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
61 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
62 #define SSH1_MSG_DEBUG 36 /* 0x24 */
63 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
64 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
65 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
66 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
67 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
68 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
69 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
71 #define SSH1_AUTH_TIS 5 /* 0x5 */
72 #define SSH1_AUTH_CCARD 16 /* 0x10 */
74 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
75 /* Mask for protoflags we will echo back to server if seen */
76 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
78 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
79 #define SSH2_MSG_IGNORE 2 /* 0x2 */
80 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
81 #define SSH2_MSG_DEBUG 4 /* 0x4 */
82 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
83 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
84 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
85 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
86 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
87 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
88 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
89 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
90 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
91 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
92 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
93 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
94 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
95 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
96 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
97 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
98 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
99 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
100 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
101 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
102 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
103 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
104 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
105 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
106 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
107 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
108 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
109 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
110 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
111 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
113 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
114 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
115 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
116 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
117 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
118 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
119 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
120 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
121 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
122 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
123 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
124 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
125 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
126 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
127 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
129 static const char *const ssh2_disconnect_reasons[] = {
131 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
132 "SSH_DISCONNECT_PROTOCOL_ERROR",
133 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
134 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
135 "SSH_DISCONNECT_MAC_ERROR",
136 "SSH_DISCONNECT_COMPRESSION_ERROR",
137 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
138 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
139 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
140 "SSH_DISCONNECT_CONNECTION_LOST",
141 "SSH_DISCONNECT_BY_APPLICATION",
142 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
143 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
144 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
145 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
148 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
149 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
150 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
151 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
153 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
156 * Various remote-bug flags.
158 #define BUG_CHOKES_ON_SSH1_IGNORE 1
159 #define BUG_SSH2_HMAC 2
161 #define GET_32BIT(cp) \
162 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
163 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
164 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
165 ((unsigned long)(unsigned char)(cp)[3]))
167 #define PUT_32BIT(cp, value) { \
168 (cp)[0] = (unsigned char)((value) >> 24); \
169 (cp)[1] = (unsigned char)((value) >> 16); \
170 (cp)[2] = (unsigned char)((value) >> 8); \
171 (cp)[3] = (unsigned char)(value); }
173 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
175 /* Coroutine mechanics for the sillier bits of the code */
176 #define crBegin1 static int crLine = 0;
177 #define crBegin2 switch(crLine) { case 0:;
178 #define crBegin crBegin1; crBegin2;
179 #define crFinish(z) } crLine = 0; return (z)
180 #define crFinishV } crLine = 0; return
181 #define crReturn(z) \
183 crLine=__LINE__; return (z); case __LINE__:;\
187 crLine=__LINE__; return; case __LINE__:;\
189 #define crStop(z) do{ crLine = 0; return (z); }while(0)
190 #define crStopV do{ crLine = 0; return; }while(0)
191 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
192 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
194 extern char *x11_init(Socket *, char *, void *);
195 extern void x11_close(Socket);
196 extern void x11_send(Socket, char *, int);
197 extern void x11_invent_auth(char *, int, char *, int);
200 * Ciphers for SSH2. We miss out single-DES because it isn't
201 * supported; also 3DES and Blowfish are both done differently from
202 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
203 * endianness and different-sized keys.)
205 const static struct ssh2_ciphers *ciphers[] = {
211 const static struct ssh_kex *kex_algs[] = {
212 &ssh_diffiehellman_gex,
216 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
218 static void nullmac_key(unsigned char *key)
221 static void nullmac_generate(unsigned char *blk, int len,
225 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
229 const static struct ssh_mac ssh_mac_none = {
230 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
232 const static struct ssh_mac *macs[] = {
233 &ssh_sha1, &ssh_md5, &ssh_mac_none
235 const static struct ssh_mac *buggymacs[] = {
236 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
239 static void ssh_comp_none_init(void)
242 static int ssh_comp_none_block(unsigned char *block, int len,
243 unsigned char **outblock, int *outlen)
247 static int ssh_comp_none_disable(void)
251 const static struct ssh_compress ssh_comp_none = {
253 ssh_comp_none_init, ssh_comp_none_block,
254 ssh_comp_none_init, ssh_comp_none_block,
255 ssh_comp_none_disable
257 extern const struct ssh_compress ssh_zlib;
258 const static struct ssh_compress *compressions[] = {
259 &ssh_zlib, &ssh_comp_none
262 enum { /* channel types */
269 * 2-3-4 tree storing channels.
272 unsigned remoteid, localid;
275 struct ssh2_data_channel {
276 unsigned char *outbuffer;
277 unsigned outbuflen, outbufsize;
278 unsigned remwindow, remmaxpkt;
281 struct ssh_agent_channel {
282 unsigned char *message;
283 unsigned char msglen[4];
284 int lensofar, totallen;
286 struct ssh_x11_channel {
301 static SHA_State exhash, exhashbase;
303 static Socket s = NULL;
305 static unsigned char session_key[32];
306 static int ssh1_compressing;
307 static int ssh1_remote_protoflags;
308 static int ssh1_local_protoflags;
309 static int ssh_agentfwd_enabled;
310 static int ssh_X11_fwd_enabled;
311 static int ssh_remote_bugs;
312 static const struct ssh_cipher *cipher = NULL;
313 static const struct ssh2_cipher *cscipher = NULL;
314 static const struct ssh2_cipher *sccipher = NULL;
315 static const struct ssh_mac *csmac = NULL;
316 static const struct ssh_mac *scmac = NULL;
317 static const struct ssh_compress *cscomp = NULL;
318 static const struct ssh_compress *sccomp = NULL;
319 static const struct ssh_kex *kex = NULL;
320 static const struct ssh_signkey *hostkey = NULL;
321 static unsigned char ssh2_session_id[20];
322 int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
325 static char *savedhost;
326 static int savedport;
327 static int ssh_send_ok;
328 static int ssh_echoing, ssh_editing;
330 static tree234 *ssh_channels; /* indexed by local id */
331 static struct ssh_channel *mainchan; /* primary session channel */
335 SSH_STATE_BEFORE_SIZE,
339 } ssh_state = SSH_STATE_PREPACKET;
341 static int size_needed = FALSE, eof_needed = FALSE;
343 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
344 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
345 static unsigned char *deferred_send_data = NULL;
346 static int deferred_len = 0, deferred_size = 0;
348 static int ssh_version;
349 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
350 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
351 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
352 static void ssh_size(void);
353 static void ssh_special(Telnet_Special);
354 static void ssh2_try_send(struct ssh_channel *c);
355 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
358 static int (*s_rdpkt) (unsigned char **data, int *datalen);
360 static struct rdpkt1_state_tag {
361 long len, pad, biglen, to_read;
362 unsigned long realcrc, gotcrc;
368 static struct rdpkt2_state_tag {
369 long len, pad, payload, packetlen, maclen;
372 unsigned long incoming_sequence;
375 static int ssh_channelcmp(void *av, void *bv)
377 struct ssh_channel *a = (struct ssh_channel *) av;
378 struct ssh_channel *b = (struct ssh_channel *) bv;
379 if (a->localid < b->localid)
381 if (a->localid > b->localid)
385 static int ssh_channelfind(void *av, void *bv)
387 unsigned *a = (unsigned *) av;
388 struct ssh_channel *b = (struct ssh_channel *) bv;
396 static int alloc_channel_id(void)
398 const unsigned CHANNEL_NUMBER_OFFSET = 256;
399 unsigned low, high, mid;
401 struct ssh_channel *c;
404 * First-fit allocation of channel numbers: always pick the
405 * lowest unused one. To do this, binary-search using the
406 * counted B-tree to find the largest channel ID which is in a
407 * contiguous sequence from the beginning. (Precisely
408 * everything in that sequence must have ID equal to its tree
409 * index plus CHANNEL_NUMBER_OFFSET.)
411 tsize = count234(ssh_channels);
415 while (high - low > 1) {
416 mid = (high + low) / 2;
417 c = index234(ssh_channels, mid);
418 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
419 low = mid; /* this one is fine */
421 high = mid; /* this one is past it */
424 * Now low points to either -1, or the tree index of the
425 * largest ID in the initial sequence.
428 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
429 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
431 return low + 1 + CHANNEL_NUMBER_OFFSET;
434 static void c_write(char *buf, int len)
436 if ((flags & FLAG_STDERR)) {
438 for (i = 0; i < len; i++)
440 fputc(buf[i], stderr);
443 from_backend(1, buf, len);
446 static void c_write_untrusted(char *buf, int len)
449 for (i = 0; i < len; i++) {
452 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
457 static void c_write_str(char *buf)
459 c_write(buf, strlen(buf));
463 * Collect incoming data in the incoming packet buffer.
464 * Decipher and verify the packet when it is completely read.
465 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
466 * Update the *data and *datalen variables.
467 * Return the additional nr of bytes needed, or 0 when
468 * a complete packet is available.
470 static int ssh1_rdpkt(unsigned char **data, int *datalen)
472 struct rdpkt1_state_tag *st = &rdpkt1_state;
481 for (st->i = st->len = 0; st->i < 4; st->i++) {
482 while ((*datalen) == 0)
484 st->len = (st->len << 8) + **data;
485 (*data)++, (*datalen)--;
489 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
490 st->len = 0x300; /* big enough to carry to end */
494 st->pad = 8 - (st->len % 8);
495 st->biglen = st->len + st->pad;
496 pktin.length = st->len - 5;
498 if (pktin.maxlen < st->biglen) {
499 pktin.maxlen = st->biglen;
500 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
501 srealloc(pktin.data, st->biglen + APIEXTRA));
503 fatalbox("Out of memory");
506 st->to_read = st->biglen;
508 while (st->to_read > 0) {
509 st->chunk = st->to_read;
510 while ((*datalen) == 0)
511 crReturn(st->to_read);
512 if (st->chunk > (*datalen))
513 st->chunk = (*datalen);
514 memcpy(st->p, *data, st->chunk);
516 *datalen -= st->chunk;
518 st->to_read -= st->chunk;
522 cipher->decrypt(pktin.data, st->biglen);
524 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
525 dmemdump(pktin.data, st->biglen);
528 st->realcrc = crc32(pktin.data, st->biglen - 4);
529 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
530 if (st->gotcrc != st->realcrc) {
531 bombout(("Incorrect CRC received on packet"));
535 pktin.body = pktin.data + st->pad + 1;
537 if (ssh1_compressing) {
538 unsigned char *decompblk;
541 debug(("Packet payload pre-decompression:\n"));
542 dmemdump(pktin.body - 1, pktin.length + 1);
544 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
545 &decompblk, &decomplen);
547 if (pktin.maxlen < st->pad + decomplen) {
548 pktin.maxlen = st->pad + decomplen;
549 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
550 pktin.body = pktin.data + st->pad + 1;
552 fatalbox("Out of memory");
555 memcpy(pktin.body - 1, decompblk, decomplen);
557 pktin.length = decomplen - 1;
559 debug(("Packet payload post-decompression:\n"));
560 dmemdump(pktin.body - 1, pktin.length + 1);
564 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
565 pktin.type == SSH1_SMSG_STDERR_DATA ||
566 pktin.type == SSH1_MSG_DEBUG ||
567 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
568 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
569 long strlen = GET_32BIT(pktin.body);
570 if (strlen + 4 != pktin.length) {
571 bombout(("Received data packet with bogus string length"));
576 pktin.type = pktin.body[-1];
578 if (pktin.type == SSH1_MSG_DEBUG) {
579 /* log debug message */
581 int strlen = GET_32BIT(pktin.body);
582 strcpy(buf, "Remote: ");
585 memcpy(buf + 8, pktin.body + 4, strlen);
586 buf[8 + strlen] = '\0';
589 } else if (pktin.type == SSH1_MSG_IGNORE) {
594 if (pktin.type == SSH1_MSG_DISCONNECT) {
595 /* log reason code in disconnect message */
597 unsigned msglen = GET_32BIT(pktin.body);
599 strcpy(buf, "Remote sent disconnect: ");
600 nowlen = strlen(buf);
601 if (msglen > sizeof(buf) - nowlen - 1)
602 msglen = sizeof(buf) - nowlen - 1;
603 memcpy(buf + nowlen, pktin.body + 4, msglen);
604 buf[nowlen + msglen] = '\0';
611 static int ssh2_rdpkt(unsigned char **data, int *datalen)
613 struct rdpkt2_state_tag *st = &rdpkt2_state;
621 st->cipherblk = sccipher->blksize;
624 if (st->cipherblk < 8)
627 if (pktin.maxlen < st->cipherblk) {
628 pktin.maxlen = st->cipherblk;
631 NULL ? smalloc(st->cipherblk +
632 APIEXTRA) : srealloc(pktin.data,
636 fatalbox("Out of memory");
640 * Acquire and decrypt the first block of the packet. This will
641 * contain the length and padding details.
643 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
644 while ((*datalen) == 0)
645 crReturn(st->cipherblk - st->i);
646 pktin.data[st->i] = *(*data)++;
650 if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */
655 sccipher->decrypt(pktin.data, st->cipherblk);
658 * Now get the length and padding figures.
660 st->len = GET_32BIT(pktin.data);
661 st->pad = pktin.data[4];
664 * This enables us to deduce the payload length.
666 st->payload = st->len - st->pad - 1;
668 pktin.length = st->payload + 5;
671 * So now we can work out the total packet length.
673 st->packetlen = st->len + 4;
674 st->maclen = scmac ? scmac->len : 0;
677 * Adjust memory allocation if packet is too big.
679 if (pktin.maxlen < st->packetlen + st->maclen) {
680 pktin.maxlen = st->packetlen + st->maclen;
683 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
688 fatalbox("Out of memory");
692 * Read and decrypt the remainder of the packet.
694 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
696 while ((*datalen) == 0)
697 crReturn(st->packetlen + st->maclen - st->i);
698 pktin.data[st->i] = *(*data)++;
701 /* Decrypt everything _except_ the MAC. */
703 sccipher->decrypt(pktin.data + st->cipherblk,
704 st->packetlen - st->cipherblk);
707 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
708 dmemdump(pktin.data, st->packetlen);
715 && !scmac->verify(pktin.data, st->len + 4,
716 st->incoming_sequence)) {
717 bombout(("Incorrect MAC received on packet"));
720 st->incoming_sequence++; /* whether or not we MACed */
723 * Decompress packet payload.
726 unsigned char *newpayload;
728 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
729 &newpayload, &newlen)) {
730 if (pktin.maxlen < newlen + 5) {
731 pktin.maxlen = newlen + 5;
734 NULL ? smalloc(pktin.maxlen +
735 APIEXTRA) : srealloc(pktin.data,
739 fatalbox("Out of memory");
741 pktin.length = 5 + newlen;
742 memcpy(pktin.data + 5, newpayload, newlen);
744 debug(("Post-decompression payload:\n"));
745 dmemdump(pktin.data + 5, newlen);
753 pktin.type = pktin.data[5];
755 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
756 goto next_packet; /* FIXME: print DEBUG message */
758 if (pktin.type == SSH2_MSG_DISCONNECT) {
759 /* log reason code in disconnect message */
761 int reason = GET_32BIT(pktin.data + 6);
762 unsigned msglen = GET_32BIT(pktin.data + 10);
764 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
765 sprintf(buf, "Received disconnect message (%s)",
766 ssh2_disconnect_reasons[reason]);
768 sprintf(buf, "Received disconnect message (unknown type %d)",
772 strcpy(buf, "Disconnection message text: ");
773 nowlen = strlen(buf);
774 if (msglen > sizeof(buf) - nowlen - 1)
775 msglen = sizeof(buf) - nowlen - 1;
776 memcpy(buf + nowlen, pktin.data + 14, msglen);
777 buf[nowlen + msglen] = '\0';
784 static void ssh1_pktout_size(int len)
788 len += 5; /* type and CRC */
792 pktout.length = len - 5;
793 if (pktout.maxlen < biglen) {
794 pktout.maxlen = biglen;
796 /* Allocate enough buffer space for extra block
797 * for MS CryptEncrypt() */
798 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
799 srealloc(pktout.data, biglen + 12));
801 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
802 srealloc(pktout.data, biglen + 4));
805 fatalbox("Out of memory");
807 pktout.body = pktout.data + 4 + pad + 1;
810 static void s_wrpkt_start(int type, int len)
812 ssh1_pktout_size(len);
816 static int s_wrpkt_prepare(void)
818 int pad, len, biglen, i;
821 pktout.body[-1] = pktout.type;
824 debug(("Packet payload pre-compression:\n"));
825 dmemdump(pktout.body - 1, pktout.length + 1);
828 if (ssh1_compressing) {
829 unsigned char *compblk;
831 zlib_compress_block(pktout.body - 1, pktout.length + 1,
833 ssh1_pktout_size(complen - 1);
834 memcpy(pktout.body - 1, compblk, complen);
837 debug(("Packet payload post-compression:\n"));
838 dmemdump(pktout.body - 1, pktout.length + 1);
842 len = pktout.length + 5; /* type and CRC */
846 for (i = 0; i < pad; i++)
847 pktout.data[i + 4] = random_byte();
848 crc = crc32(pktout.data + 4, biglen - 4);
849 PUT_32BIT(pktout.data + biglen, crc);
850 PUT_32BIT(pktout.data, len);
853 debug(("Sending packet len=%d\n", biglen + 4));
854 dmemdump(pktout.data, biglen + 4);
857 cipher->encrypt(pktout.data + 4, biglen);
862 static void s_wrpkt(void)
865 len = s_wrpkt_prepare();
866 sk_write(s, pktout.data, len);
869 static void s_wrpkt_defer(void)
872 len = s_wrpkt_prepare();
873 if (deferred_len + len > deferred_size) {
874 deferred_size = deferred_len + len + 128;
875 deferred_send_data = srealloc(deferred_send_data, deferred_size);
877 memcpy(deferred_send_data + deferred_len, pktout.data, len);
882 * Construct a packet with the specified contents.
884 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
886 unsigned char *p, *argp, argchar;
887 unsigned long argint;
888 int pktlen, argtype, arglen;
892 while ((argtype = va_arg(ap1, int)) != PKT_END) {
895 (void) va_arg(ap1, int);
899 (void) va_arg(ap1, char);
903 (void) va_arg(ap1, unsigned char *);
904 arglen = va_arg(ap1, int);
908 argp = va_arg(ap1, unsigned char *);
909 arglen = strlen(argp);
910 pktlen += 4 + arglen;
913 bn = va_arg(ap1, Bignum);
914 pktlen += ssh1_bignum_length(bn);
921 s_wrpkt_start(pkttype, pktlen);
924 while ((argtype = va_arg(ap2, int)) != PKT_END) {
927 argint = va_arg(ap2, int);
928 PUT_32BIT(p, argint);
932 argchar = va_arg(ap2, unsigned char);
937 argp = va_arg(ap2, unsigned char *);
938 arglen = va_arg(ap2, int);
939 memcpy(p, argp, arglen);
943 argp = va_arg(ap2, unsigned char *);
944 arglen = strlen(argp);
945 PUT_32BIT(p, arglen);
946 memcpy(p + 4, argp, arglen);
950 bn = va_arg(ap2, Bignum);
951 p += ssh1_write_bignum(p, bn);
957 static void send_packet(int pkttype, ...)
960 va_start(ap1, pkttype);
961 va_start(ap2, pkttype);
962 construct_packet(pkttype, ap1, ap2);
966 static void defer_packet(int pkttype, ...)
969 va_start(ap1, pkttype);
970 va_start(ap2, pkttype);
971 construct_packet(pkttype, ap1, ap2);
975 static int ssh_versioncmp(char *a, char *b)
978 unsigned long av, bv;
980 av = strtoul(a, &ae, 10);
981 bv = strtoul(b, &be, 10);
983 return (av < bv ? -1 : +1);
988 av = strtoul(ae, &ae, 10);
989 bv = strtoul(be, &be, 10);
991 return (av < bv ? -1 : +1);
997 * Utility routines for putting an SSH-protocol `string' and
998 * `uint32' into a SHA state.
1001 static void sha_string(SHA_State * s, void *str, int len)
1003 unsigned char lenblk[4];
1004 PUT_32BIT(lenblk, len);
1005 SHA_Bytes(s, lenblk, 4);
1006 SHA_Bytes(s, str, len);
1009 static void sha_uint32(SHA_State * s, unsigned i)
1011 unsigned char intblk[4];
1012 PUT_32BIT(intblk, i);
1013 SHA_Bytes(s, intblk, 4);
1017 * SSH2 packet construction functions.
1019 static void ssh2_pkt_ensure(int length)
1021 if (pktout.maxlen < length) {
1022 pktout.maxlen = length + 256;
1025 NULL ? smalloc(pktout.maxlen +
1026 APIEXTRA) : srealloc(pktout.data,
1030 fatalbox("Out of memory");
1033 static void ssh2_pkt_adddata(void *data, int len)
1035 pktout.length += len;
1036 ssh2_pkt_ensure(pktout.length);
1037 memcpy(pktout.data + pktout.length - len, data, len);
1039 static void ssh2_pkt_addbyte(unsigned char byte)
1041 ssh2_pkt_adddata(&byte, 1);
1043 static void ssh2_pkt_init(int pkt_type)
1046 ssh2_pkt_addbyte((unsigned char) pkt_type);
1048 static void ssh2_pkt_addbool(unsigned char value)
1050 ssh2_pkt_adddata(&value, 1);
1052 static void ssh2_pkt_adduint32(unsigned long value)
1055 PUT_32BIT(x, value);
1056 ssh2_pkt_adddata(x, 4);
1058 static void ssh2_pkt_addstring_start(void)
1060 ssh2_pkt_adduint32(0);
1061 pktout.savedpos = pktout.length;
1063 static void ssh2_pkt_addstring_str(char *data)
1065 ssh2_pkt_adddata(data, strlen(data));
1066 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1067 pktout.length - pktout.savedpos);
1069 static void ssh2_pkt_addstring_data(char *data, int len)
1071 ssh2_pkt_adddata(data, len);
1072 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1073 pktout.length - pktout.savedpos);
1075 static void ssh2_pkt_addstring(char *data)
1077 ssh2_pkt_addstring_start();
1078 ssh2_pkt_addstring_str(data);
1080 static char *ssh2_mpint_fmt(Bignum b, int *len)
1083 int i, n = (bignum_bitcount(b) + 7) / 8;
1086 fatalbox("out of memory");
1088 for (i = 1; i <= n; i++)
1089 p[i] = bignum_byte(b, n - i);
1091 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1093 memmove(p, p + i, n + 1 - i);
1097 static void ssh2_pkt_addmp(Bignum b)
1101 p = ssh2_mpint_fmt(b, &len);
1102 ssh2_pkt_addstring_start();
1103 ssh2_pkt_addstring_data(p, len);
1108 * Construct an SSH2 final-form packet: compress it, encrypt it,
1109 * put the MAC on it. Final packet, ready to be sent, is stored in
1110 * pktout.data. Total length is returned.
1112 static int ssh2_pkt_construct(void)
1114 int cipherblk, maclen, padding, i;
1115 static unsigned long outgoing_sequence = 0;
1118 * Compress packet payload.
1121 debug(("Pre-compression payload:\n"));
1122 dmemdump(pktout.data + 5, pktout.length - 5);
1125 unsigned char *newpayload;
1127 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1128 &newpayload, &newlen)) {
1130 ssh2_pkt_adddata(newpayload, newlen);
1136 * Add padding. At least four bytes, and must also bring total
1137 * length (minus MAC) up to a multiple of the block size.
1139 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1140 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1143 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1144 maclen = csmac ? csmac->len : 0;
1145 ssh2_pkt_ensure(pktout.length + padding + maclen);
1146 pktout.data[4] = padding;
1147 for (i = 0; i < padding; i++)
1148 pktout.data[pktout.length + i] = random_byte();
1149 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1151 csmac->generate(pktout.data, pktout.length + padding,
1153 outgoing_sequence++; /* whether or not we MACed */
1156 debug(("Sending packet len=%d\n", pktout.length + padding));
1157 dmemdump(pktout.data, pktout.length + padding);
1161 cscipher->encrypt(pktout.data, pktout.length + padding);
1163 /* Ready-to-send packet starts at pktout.data. We return length. */
1164 return pktout.length + padding + maclen;
1168 * Construct and send an SSH2 packet immediately.
1170 static void ssh2_pkt_send(void)
1172 int len = ssh2_pkt_construct();
1173 sk_write(s, pktout.data, len);
1177 * Construct an SSH2 packet and add it to a deferred data block.
1178 * Useful for sending multiple packets in a single sk_write() call,
1179 * to prevent a traffic-analysing listener from being able to work
1180 * out the length of any particular packet (such as the password
1183 * Note that because SSH2 sequence-numbers its packets, this can
1184 * NOT be used as an m4-style `defer' allowing packets to be
1185 * constructed in one order and sent in another.
1187 static void ssh2_pkt_defer(void)
1189 int len = ssh2_pkt_construct();
1190 if (deferred_len + len > deferred_size) {
1191 deferred_size = deferred_len + len + 128;
1192 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1194 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1195 deferred_len += len;
1199 * Send the whole deferred data block constructed by
1200 * ssh2_pkt_defer() or SSH1's defer_packet().
1202 static void ssh_pkt_defersend(void)
1204 sk_write(s, deferred_send_data, deferred_len);
1205 deferred_len = deferred_size = 0;
1206 sfree(deferred_send_data);
1207 deferred_send_data = NULL;
1211 void bndebug(char *string, Bignum b)
1215 p = ssh2_mpint_fmt(b, &len);
1216 debug(("%s", string));
1217 for (i = 0; i < len; i++)
1218 debug((" %02x", p[i]));
1224 static void sha_mpint(SHA_State * s, Bignum b)
1228 p = ssh2_mpint_fmt(b, &len);
1229 sha_string(s, p, len);
1234 * SSH2 packet decode functions.
1236 static unsigned long ssh2_pkt_getuint32(void)
1238 unsigned long value;
1239 if (pktin.length - pktin.savedpos < 4)
1240 return 0; /* arrgh, no way to decline (FIXME?) */
1241 value = GET_32BIT(pktin.data + pktin.savedpos);
1242 pktin.savedpos += 4;
1245 static int ssh2_pkt_getbool(void)
1247 unsigned long value;
1248 if (pktin.length - pktin.savedpos < 1)
1249 return 0; /* arrgh, no way to decline (FIXME?) */
1250 value = pktin.data[pktin.savedpos] != 0;
1254 static void ssh2_pkt_getstring(char **p, int *length)
1257 if (pktin.length - pktin.savedpos < 4)
1259 *length = GET_32BIT(pktin.data + pktin.savedpos);
1260 pktin.savedpos += 4;
1261 if (pktin.length - pktin.savedpos < *length)
1263 *p = pktin.data + pktin.savedpos;
1264 pktin.savedpos += *length;
1266 static Bignum ssh2_pkt_getmp(void)
1272 ssh2_pkt_getstring(&p, &length);
1276 bombout(("internal error: Can't handle negative mpints"));
1279 b = bignum_from_bytes(p, length);
1284 * Examine the remote side's version string and compare it against
1285 * a list of known buggy implementations.
1287 static void ssh_detect_bugs(char *vstring)
1289 char *imp; /* pointer to implementation part */
1291 imp += strcspn(imp, "-");
1294 imp += strcspn(imp, "-");
1298 ssh_remote_bugs = 0;
1300 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1301 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1302 !strcmp(imp, "1.2.22")) {
1304 * These versions don't support SSH1_MSG_IGNORE, so we have
1305 * to use a different defence against password length
1308 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1309 logevent("We believe remote version has SSH1 ignore bug");
1312 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1313 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1314 !strncmp(imp, "2.1 ", 4)) {
1316 * These versions have the HMAC bug.
1318 ssh_remote_bugs |= BUG_SSH2_HMAC;
1319 logevent("We believe remote version has SSH2 HMAC bug");
1323 static int do_ssh_init(unsigned char c)
1326 static char version[10];
1327 static char *vstring;
1328 static int vstrsize;
1334 /* Search for the string "SSH-" in the input. */
1337 static const int transS[] = { 1, 2, 2, 1 };
1338 static const int transH[] = { 0, 0, 3, 0 };
1339 static const int transminus[] = { 0, 0, 0, -1 };
1350 crReturn(1); /* get another character */
1353 vstring = smalloc(16);
1355 strcpy(vstring, "SSH-");
1359 crReturn(1); /* get another char */
1360 if (vslen >= vstrsize - 1) {
1362 vstring = srealloc(vstring, vstrsize);
1364 vstring[vslen++] = c;
1369 } else if (i < sizeof(version) - 1)
1371 } else if (c == '\n')
1375 ssh_agentfwd_enabled = FALSE;
1376 rdpkt2_state.incoming_sequence = 0;
1379 vlog = smalloc(20 + vslen);
1380 sprintf(vlog, "Server version: %s", vstring);
1381 ssh_detect_bugs(vstring);
1382 vlog[strcspn(vlog, "\r\n")] = '\0';
1387 * Server version "1.99" means we can choose whether we use v1
1388 * or v2 protocol. Choice is based on cfg.sshprot.
1390 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1392 * This is a v2 server. Begin v2 protocol.
1394 char verstring[80], vlog[100];
1395 sprintf(verstring, "SSH-2.0-%s", sshver);
1396 SHA_Init(&exhashbase);
1398 * Hash our version string and their version string.
1400 sha_string(&exhashbase, verstring, strlen(verstring));
1401 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1402 sprintf(vlog, "We claim version: %s", verstring);
1404 strcat(verstring, "\n");
1405 logevent("Using SSH protocol version 2");
1406 sk_write(s, verstring, strlen(verstring));
1407 ssh_protocol = ssh2_protocol;
1409 s_rdpkt = ssh2_rdpkt;
1412 * This is a v1 server. Begin v1 protocol.
1414 char verstring[80], vlog[100];
1415 sprintf(verstring, "SSH-%s-%s",
1416 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1418 sprintf(vlog, "We claim version: %s", verstring);
1420 strcat(verstring, "\n");
1421 logevent("Using SSH protocol version 1");
1422 sk_write(s, verstring, strlen(verstring));
1423 ssh_protocol = ssh1_protocol;
1425 s_rdpkt = ssh1_rdpkt;
1427 ssh_state = SSH_STATE_BEFORE_SIZE;
1434 static void ssh_gotdata(unsigned char *data, int datalen)
1439 * To begin with, feed the characters one by one to the
1440 * protocol initialisation / selection function do_ssh_init().
1441 * When that returns 0, we're done with the initial greeting
1442 * exchange and can move on to packet discipline.
1447 crReturnV; /* more data please */
1448 ret = do_ssh_init(*data);
1456 * We emerge from that loop when the initial negotiation is
1457 * over and we have selected an s_rdpkt function. Now pass
1458 * everything to s_rdpkt, and then pass the resulting packets
1459 * to the proper protocol handler.
1464 while (datalen > 0) {
1465 if (s_rdpkt(&data, &datalen) == 0) {
1466 ssh_protocol(NULL, 0, 1);
1467 if (ssh_state == SSH_STATE_CLOSED) {
1477 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1480 ssh_state = SSH_STATE_CLOSED;
1484 /* A socket error has occurred. */
1485 connection_fatal(error_msg);
1487 /* Otherwise, the remote side closed the connection normally. */
1492 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1494 ssh_gotdata(data, len);
1495 if (ssh_state == SSH_STATE_CLOSED) {
1506 * Connect to specified host and port.
1507 * Returns an error message, or NULL on success.
1508 * Also places the canonical host name into `realhost'. It must be
1509 * freed by the caller.
1511 static char *connect_to_host(char *host, int port, char **realhost)
1513 static struct plug_function_table fn_table = {
1516 }, *fn_table_ptr = &fn_table;
1525 savedhost = smalloc(1 + strlen(host));
1527 fatalbox("Out of memory");
1528 strcpy(savedhost, host);
1531 port = 22; /* default ssh port */
1544 addr = sk_namelookup(host, realhost);
1545 if ((err = sk_addr_error(addr)))
1549 *realhost = strdup(FWhost);
1555 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1556 if ((err = sk_socket_error(s)))
1560 sk_write(s, "connect ", 8);
1561 sk_write(s, FWhost, strlen(FWhost));
1564 sprintf(buf, " %d\n", FWport);
1565 sk_write(s, buf, strlen(buf));
1573 * Handle the key exchange and user authentication phases.
1575 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1578 unsigned char *rsabuf, *keystr1, *keystr2;
1579 unsigned char cookie[8];
1580 struct RSAKey servkey, hostkey;
1581 struct MD5Context md5c;
1582 static unsigned long supported_ciphers_mask, supported_auths_mask;
1583 static int tried_publickey;
1584 static unsigned char session_id[16];
1586 static char username[100];
1593 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1594 bombout(("Public key packet not received"));
1598 logevent("Received public keys");
1600 memcpy(cookie, pktin.body, 8);
1602 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1603 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1606 * Log the host key fingerprint.
1610 logevent("Host key fingerprint is:");
1611 strcpy(logmsg, " ");
1612 hostkey.comment = NULL;
1613 rsa_fingerprint(logmsg + strlen(logmsg),
1614 sizeof(logmsg) - strlen(logmsg), &hostkey);
1618 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1619 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1620 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1622 ssh1_local_protoflags =
1623 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1624 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1627 MD5Update(&md5c, keystr2, hostkey.bytes);
1628 MD5Update(&md5c, keystr1, servkey.bytes);
1629 MD5Update(&md5c, pktin.body, 8);
1630 MD5Final(session_id, &md5c);
1632 for (i = 0; i < 32; i++)
1633 session_key[i] = random_byte();
1635 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1637 rsabuf = smalloc(len);
1639 fatalbox("Out of memory");
1642 * Verify the host key.
1646 * First format the key into a string.
1648 int len = rsastr_len(&hostkey);
1649 char fingerprint[100];
1650 char *keystr = smalloc(len);
1652 fatalbox("Out of memory");
1653 rsastr_fmt(keystr, &hostkey);
1654 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1655 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1660 for (i = 0; i < 32; i++) {
1661 rsabuf[i] = session_key[i];
1663 rsabuf[i] ^= session_id[i];
1666 if (hostkey.bytes > servkey.bytes) {
1667 rsaencrypt(rsabuf, 32, &servkey);
1668 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1670 rsaencrypt(rsabuf, 32, &hostkey);
1671 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1674 logevent("Encrypted session key");
1676 switch (cfg.cipher) {
1677 case CIPHER_BLOWFISH:
1678 cipher_type = SSH_CIPHER_BLOWFISH;
1681 cipher_type = SSH_CIPHER_DES;
1684 cipher_type = SSH_CIPHER_3DES;
1687 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1688 cipher_type = SSH_CIPHER_3DES;
1691 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1693 ("Selected cipher not supported, falling back to 3DES\r\n");
1694 cipher_type = SSH_CIPHER_3DES;
1695 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1696 bombout(("Server violates SSH 1 protocol by "
1697 "not supporting 3DES encryption"));
1701 switch (cipher_type) {
1702 case SSH_CIPHER_3DES:
1703 logevent("Using 3DES encryption");
1705 case SSH_CIPHER_DES:
1706 logevent("Using single-DES encryption");
1708 case SSH_CIPHER_BLOWFISH:
1709 logevent("Using Blowfish encryption");
1713 send_packet(SSH1_CMSG_SESSION_KEY,
1714 PKT_CHAR, cipher_type,
1715 PKT_DATA, cookie, 8,
1716 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1717 PKT_DATA, rsabuf, len,
1718 PKT_INT, ssh1_local_protoflags, PKT_END);
1720 logevent("Trying to enable encryption...");
1724 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1725 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
1726 cipher->sesskey(session_key);
1730 if (pktin.type != SSH1_SMSG_SUCCESS) {
1731 bombout(("Encryption not successfully enabled"));
1735 logevent("Successfully started encryption");
1741 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1743 if (!ssh_get_line("login as: ",
1744 username, sizeof(username), FALSE)) {
1746 * get_line failed to get a username.
1749 logevent("No username provided. Abandoning session.");
1750 ssh_state = SSH_STATE_CLOSED;
1754 c_write_str("login as: ");
1757 crWaitUntil(!ispkt);
1759 switch (c = *in++) {
1768 c_write_str("\b \b");
1775 c_write_str("\b \b");
1785 if (((c >= ' ' && c <= '~') ||
1786 ((unsigned char) c >= 160))
1787 && pos < sizeof(username)-1) {
1788 username[pos++] = c;
1794 c_write_str("\r\n");
1795 username[strcspn(username, "\n\r")] = '\0';
1798 strncpy(username, cfg.username, 99);
1799 username[99] = '\0';
1802 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1804 char userlog[22 + sizeof(username)];
1805 sprintf(userlog, "Sent username \"%s\"", username);
1807 if (flags & FLAG_INTERACTIVE &&
1808 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1809 strcat(userlog, "\r\n");
1810 c_write_str(userlog);
1817 tried_publickey = 0;
1819 while (pktin.type == SSH1_SMSG_FAILURE) {
1820 static char password[100];
1821 static char prompt[200];
1824 static int pwpkt_type;
1826 * Show password prompt, having first obtained it via a TIS
1827 * or CryptoCard exchange if we're doing TIS or CryptoCard
1830 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1831 if (agent_exists()) {
1833 * Attempt RSA authentication using Pageant.
1835 static unsigned char request[5], *response, *p;
1836 static int responselen;
1837 static int i, nkeys;
1838 static int authed = FALSE;
1841 logevent("Pageant is running. Requesting keys.");
1843 /* Request the keys held by the agent. */
1844 PUT_32BIT(request, 1);
1845 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1846 agent_query(request, 5, &r, &responselen);
1847 response = (unsigned char *) r;
1848 if (response && responselen >= 5 &&
1849 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
1851 nkeys = GET_32BIT(p);
1855 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1858 for (i = 0; i < nkeys; i++) {
1859 static struct RSAKey key;
1860 static Bignum challenge;
1861 static char *commentp;
1862 static int commentlen;
1866 sprintf(buf, "Trying Pageant key #%d", i);
1870 p += ssh1_read_bignum(p, &key.exponent);
1871 p += ssh1_read_bignum(p, &key.modulus);
1872 commentlen = GET_32BIT(p);
1876 send_packet(SSH1_CMSG_AUTH_RSA,
1877 PKT_BIGNUM, key.modulus, PKT_END);
1879 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1880 logevent("Key refused");
1883 logevent("Received RSA challenge");
1884 ssh1_read_bignum(pktin.body, &challenge);
1886 char *agentreq, *q, *ret;
1888 len = 1 + 4; /* message type, bit count */
1889 len += ssh1_bignum_length(key.exponent);
1890 len += ssh1_bignum_length(key.modulus);
1891 len += ssh1_bignum_length(challenge);
1892 len += 16; /* session id */
1893 len += 4; /* response format */
1894 agentreq = smalloc(4 + len);
1895 PUT_32BIT(agentreq, len);
1897 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1898 PUT_32BIT(q, bignum_bitcount(key.modulus));
1900 q += ssh1_write_bignum(q, key.exponent);
1901 q += ssh1_write_bignum(q, key.modulus);
1902 q += ssh1_write_bignum(q, challenge);
1903 memcpy(q, session_id, 16);
1905 PUT_32BIT(q, 1); /* response format */
1906 agent_query(agentreq, len + 4, &ret, &retlen);
1909 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1910 logevent("Sending Pageant's response");
1911 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1912 PKT_DATA, ret + 5, 16,
1916 if (pktin.type == SSH1_SMSG_SUCCESS) {
1918 ("Pageant's response accepted");
1919 if (flags & FLAG_VERBOSE) {
1921 ("Authenticated using RSA key \"");
1922 c_write(commentp, commentlen);
1923 c_write_str("\" from agent\r\n");
1928 ("Pageant's response not accepted");
1931 ("Pageant failed to answer challenge");
1935 logevent("No reply received from Pageant");
1938 freebn(key.exponent);
1939 freebn(key.modulus);
1948 if (*cfg.keyfile && !tried_publickey)
1949 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1951 if (pktin.type == SSH1_SMSG_FAILURE &&
1953 (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
1954 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1955 logevent("Requested TIS authentication");
1956 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1958 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1959 logevent("TIS authentication declined");
1960 if (flags & FLAG_INTERACTIVE)
1961 c_write_str("TIS authentication refused.\r\n");
1963 int challengelen = ((pktin.body[0] << 24) |
1964 (pktin.body[1] << 16) |
1965 (pktin.body[2] << 8) |
1967 logevent("Received TIS challenge");
1968 if (challengelen > sizeof(prompt) - 1)
1969 challengelen = sizeof(prompt) - 1; /* prevent overrun */
1970 memcpy(prompt, pktin.body + 4, challengelen);
1971 prompt[challengelen] = '\0';
1974 if (pktin.type == SSH1_SMSG_FAILURE &&
1976 (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
1977 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1978 logevent("Requested CryptoCard authentication");
1979 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1981 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1982 logevent("CryptoCard authentication declined");
1983 c_write_str("CryptoCard authentication refused.\r\n");
1985 int challengelen = ((pktin.body[0] << 24) |
1986 (pktin.body[1] << 16) |
1987 (pktin.body[2] << 8) |
1989 logevent("Received CryptoCard challenge");
1990 if (challengelen > sizeof(prompt) - 1)
1991 challengelen = sizeof(prompt) - 1; /* prevent overrun */
1992 memcpy(prompt, pktin.body + 4, challengelen);
1993 strncpy(prompt + challengelen, "\r\nResponse : ",
1994 sizeof(prompt) - challengelen);
1995 prompt[sizeof(prompt) - 1] = '\0';
1998 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1999 sprintf(prompt, "%.90s@%.90s's password: ",
2000 username, savedhost);
2002 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2003 char *comment = NULL;
2004 if (flags & FLAG_VERBOSE)
2005 c_write_str("Trying public key authentication.\r\n");
2006 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2007 if (flags & FLAG_VERBOSE)
2008 c_write_str("No passphrase required.\r\n");
2011 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2016 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2018 * get_line failed to get a password (for example
2019 * because one was supplied on the command line
2020 * which has already failed to work). Terminate.
2022 send_packet(SSH1_MSG_DISCONNECT,
2023 PKT_STR, "No more passwords available to try",
2025 connection_fatal("Unable to authenticate");
2026 ssh_state = SSH_STATE_CLOSED;
2030 c_write_str(prompt);
2034 crWaitUntil(!ispkt);
2036 switch (c = *in++) {
2057 if (pos < sizeof(password)-1)
2058 password[pos++] = c;
2062 c_write_str("\r\n");
2066 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2068 * Try public key authentication with the specified
2071 static struct RSAKey pubkey;
2072 static Bignum challenge, response;
2074 static unsigned char buffer[32];
2076 tried_publickey = 1;
2077 i = loadrsakey(cfg.keyfile, &pubkey, password);
2079 c_write_str("Couldn't load public key from ");
2080 c_write_str(cfg.keyfile);
2081 c_write_str(".\r\n");
2082 continue; /* go and try password */
2085 c_write_str("Wrong passphrase.\r\n");
2086 tried_publickey = 0;
2087 continue; /* try again */
2091 * Send a public key attempt.
2093 send_packet(SSH1_CMSG_AUTH_RSA,
2094 PKT_BIGNUM, pubkey.modulus, PKT_END);
2097 if (pktin.type == SSH1_SMSG_FAILURE) {
2098 c_write_str("Server refused our public key.\r\n");
2099 continue; /* go and try password */
2101 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2102 bombout(("Bizarre response to offer of public key"));
2105 ssh1_read_bignum(pktin.body, &challenge);
2106 response = rsadecrypt(challenge, &pubkey);
2107 freebn(pubkey.private_exponent); /* burn the evidence */
2109 for (i = 0; i < 32; i++) {
2110 buffer[i] = bignum_byte(response, 31 - i);
2114 MD5Update(&md5c, buffer, 32);
2115 MD5Update(&md5c, session_id, 16);
2116 MD5Final(buffer, &md5c);
2118 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2119 PKT_DATA, buffer, 16, PKT_END);
2122 if (pktin.type == SSH1_SMSG_FAILURE) {
2123 if (flags & FLAG_VERBOSE)
2125 ("Failed to authenticate with our public key.\r\n");
2126 continue; /* go and try password */
2127 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2129 ("Bizarre response to RSA authentication response"));
2133 break; /* we're through! */
2135 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2137 * Defence against traffic analysis: we send a
2138 * whole bunch of packets containing strings of
2139 * different lengths. One of these strings is the
2140 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2141 * The others are all random data in
2142 * SSH1_MSG_IGNORE packets. This way a passive
2143 * listener can't tell which is the password, and
2144 * hence can't deduce the password length.
2146 * Anybody with a password length greater than 16
2147 * bytes is going to have enough entropy in their
2148 * password that a listener won't find it _that_
2149 * much help to know how long it is. So what we'll
2152 * - if password length < 16, we send 15 packets
2153 * containing string lengths 1 through 15
2155 * - otherwise, we let N be the nearest multiple
2156 * of 8 below the password length, and send 8
2157 * packets containing string lengths N through
2158 * N+7. This won't obscure the order of
2159 * magnitude of the password length, but it will
2160 * introduce a bit of extra uncertainty.
2162 * A few servers (the old 1.2.18 through 1.2.22)
2163 * can't deal with SSH1_MSG_IGNORE. For these
2164 * servers, we need an alternative defence. We make
2165 * use of the fact that the password is interpreted
2166 * as a C string: so we can append a NUL, then some
2169 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2174 len = strlen(password);
2175 if (len < sizeof(string)) {
2177 strcpy(string, password);
2178 len++; /* cover the zero byte */
2179 while (len < sizeof(string)) {
2180 string[len++] = (char) random_byte();
2185 send_packet(pwpkt_type, PKT_INT, len,
2186 PKT_DATA, s, len, PKT_END);
2188 int bottom, top, pwlen, i;
2191 pwlen = strlen(password);
2193 bottom = 0; /* zero length passwords are OK! :-) */
2196 bottom = pwlen & ~7;
2200 assert(pwlen >= bottom && pwlen <= top);
2202 randomstr = smalloc(top + 1);
2204 for (i = bottom; i <= top; i++) {
2206 defer_packet(pwpkt_type, PKT_STR, password,
2209 for (j = 0; j < i; j++) {
2211 randomstr[j] = random_byte();
2212 } while (randomstr[j] == '\0');
2214 randomstr[i] = '\0';
2215 defer_packet(SSH1_MSG_IGNORE,
2216 PKT_STR, randomstr, PKT_END);
2219 ssh_pkt_defersend();
2222 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2225 logevent("Sent password");
2226 memset(password, 0, strlen(password));
2228 if (pktin.type == SSH1_SMSG_FAILURE) {
2229 if (flags & FLAG_VERBOSE)
2230 c_write_str("Access denied\r\n");
2231 logevent("Authentication refused");
2232 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2233 logevent("Received disconnect request");
2234 ssh_state = SSH_STATE_CLOSED;
2236 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2237 bombout(("Strange packet received, type %d", pktin.type));
2242 logevent("Authentication successful");
2247 void sshfwd_close(struct ssh_channel *c)
2249 if (c && !c->closes) {
2250 if (ssh_version == 1) {
2251 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2254 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2255 ssh2_pkt_adduint32(c->remoteid);
2259 if (c->type == CHAN_X11) {
2261 logevent("X11 connection terminated");
2266 void sshfwd_write(struct ssh_channel *c, char *buf, int len)
2268 if (ssh_version == 1) {
2269 send_packet(SSH1_MSG_CHANNEL_DATA,
2270 PKT_INT, c->remoteid,
2271 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2273 ssh2_add_channel_data(c, buf, len);
2278 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2284 while (!do_ssh1_login(in, inlen, ispkt)) {
2287 if (ssh_state == SSH_STATE_CLOSED)
2290 if (cfg.agentfwd && agent_exists()) {
2291 logevent("Requesting agent forwarding");
2292 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2296 if (pktin.type != SSH1_SMSG_SUCCESS
2297 && pktin.type != SSH1_SMSG_FAILURE) {
2298 bombout(("Protocol confusion"));
2300 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2301 logevent("Agent forwarding refused");
2303 logevent("Agent forwarding enabled");
2304 ssh_agentfwd_enabled = TRUE;
2308 if (cfg.x11_forward) {
2309 char proto[20], data[64];
2310 logevent("Requesting X11 forwarding");
2311 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2312 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2313 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2314 PKT_STR, proto, PKT_STR, data,
2315 PKT_INT, 0, PKT_END);
2317 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2318 PKT_STR, proto, PKT_STR, data, PKT_END);
2323 if (pktin.type != SSH1_SMSG_SUCCESS
2324 && pktin.type != SSH1_SMSG_FAILURE) {
2325 bombout(("Protocol confusion"));
2327 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2328 logevent("X11 forwarding refused");
2330 logevent("X11 forwarding enabled");
2331 ssh_X11_fwd_enabled = TRUE;
2336 send_packet(SSH1_CMSG_REQUEST_PTY,
2337 PKT_STR, cfg.termtype,
2338 PKT_INT, rows, PKT_INT, cols,
2339 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2340 ssh_state = SSH_STATE_INTERMED;
2344 if (pktin.type != SSH1_SMSG_SUCCESS
2345 && pktin.type != SSH1_SMSG_FAILURE) {
2346 bombout(("Protocol confusion"));
2348 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2349 c_write_str("Server refused to allocate pty\r\n");
2350 ssh_editing = ssh_echoing = 1;
2352 logevent("Allocated pty");
2354 ssh_editing = ssh_echoing = 1;
2357 if (cfg.compression) {
2358 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2362 if (pktin.type != SSH1_SMSG_SUCCESS
2363 && pktin.type != SSH1_SMSG_FAILURE) {
2364 bombout(("Protocol confusion"));
2366 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2367 c_write_str("Server refused to compress\r\n");
2369 logevent("Started compression");
2370 ssh1_compressing = TRUE;
2371 zlib_compress_init();
2372 zlib_decompress_init();
2375 if (*cfg.remote_cmd_ptr)
2376 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr,
2379 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2380 logevent("Started session");
2382 ssh_state = SSH_STATE_SESSION;
2386 ssh_special(TS_EOF);
2388 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2390 ssh_channels = newtree234(ssh_channelcmp);
2394 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2395 pktin.type == SSH1_SMSG_STDERR_DATA) {
2396 long len = GET_32BIT(pktin.body);
2397 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2398 pktin.body + 4, len);
2399 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2400 ssh_state = SSH_STATE_CLOSED;
2401 logevent("Received disconnect request");
2403 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2404 /* Remote side is trying to open a channel to talk to our
2405 * X-Server. Give them back a local channel number. */
2406 struct ssh_channel *c;
2408 logevent("Received X11 connect request");
2409 /* Refuse if X11 forwarding is disabled. */
2410 if (!ssh_X11_fwd_enabled) {
2411 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2412 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2413 logevent("Rejected X11 connect request");
2415 c = smalloc(sizeof(struct ssh_channel));
2417 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2418 logevent("opening X11 forward connection failed");
2420 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2421 PKT_INT, GET_32BIT(pktin.body),
2425 ("opening X11 forward connection succeeded");
2426 c->remoteid = GET_32BIT(pktin.body);
2427 c->localid = alloc_channel_id();
2429 c->type = CHAN_X11; /* identify channel type */
2430 add234(ssh_channels, c);
2431 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2432 PKT_INT, c->remoteid, PKT_INT,
2433 c->localid, PKT_END);
2434 logevent("Opened X11 forward channel");
2437 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2438 /* Remote side is trying to open a channel to talk to our
2439 * agent. Give them back a local channel number. */
2440 struct ssh_channel *c;
2442 /* Refuse if agent forwarding is disabled. */
2443 if (!ssh_agentfwd_enabled) {
2444 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2445 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2447 c = smalloc(sizeof(struct ssh_channel));
2448 c->remoteid = GET_32BIT(pktin.body);
2449 c->localid = alloc_channel_id();
2451 c->type = CHAN_AGENT; /* identify channel type */
2452 c->u.a.lensofar = 0;
2453 add234(ssh_channels, c);
2454 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2455 PKT_INT, c->remoteid, PKT_INT, c->localid,
2458 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2459 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2460 /* Remote side closes a channel. */
2461 unsigned i = GET_32BIT(pktin.body);
2462 struct ssh_channel *c;
2463 c = find234(ssh_channels, &i, ssh_channelfind);
2467 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2468 if (!(c->closes & closetype))
2469 send_packet(pktin.type, PKT_INT, c->remoteid,
2471 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2472 logevent("X11 connection closed");
2473 assert(c->u.x11.s != NULL);
2474 x11_close(c->u.x11.s);
2477 c->closes |= closetype;
2478 if (c->closes == 3) {
2479 del234(ssh_channels, c);
2483 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2484 /* Data sent down one of our channels. */
2485 int i = GET_32BIT(pktin.body);
2486 int len = GET_32BIT(pktin.body + 4);
2487 unsigned char *p = pktin.body + 8;
2488 struct ssh_channel *c;
2489 c = find234(ssh_channels, &i, ssh_channelfind);
2493 x11_send(c->u.x11.s, p, len);
2496 /* Data for an agent message. Buffer it. */
2498 if (c->u.a.lensofar < 4) {
2499 int l = min(4 - c->u.a.lensofar, len);
2500 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2504 c->u.a.lensofar += l;
2506 if (c->u.a.lensofar == 4) {
2508 4 + GET_32BIT(c->u.a.msglen);
2509 c->u.a.message = smalloc(c->u.a.totallen);
2510 memcpy(c->u.a.message, c->u.a.msglen, 4);
2512 if (c->u.a.lensofar >= 4 && len > 0) {
2514 min(c->u.a.totallen - c->u.a.lensofar,
2516 memcpy(c->u.a.message + c->u.a.lensofar, p,
2520 c->u.a.lensofar += l;
2522 if (c->u.a.lensofar == c->u.a.totallen) {
2523 void *reply, *sentreply;
2525 agent_query(c->u.a.message,
2526 c->u.a.totallen, &reply,
2531 /* Fake SSH_AGENT_FAILURE. */
2532 sentreply = "\0\0\0\1\5";
2535 send_packet(SSH1_MSG_CHANNEL_DATA,
2536 PKT_INT, c->remoteid,
2538 PKT_DATA, sentreply, replylen,
2542 sfree(c->u.a.message);
2543 c->u.a.lensofar = 0;
2549 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2550 /* may be from EXEC_SHELL on some servers */
2551 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2552 /* may be from EXEC_SHELL on some servers
2553 * if no pty is available or in other odd cases. Ignore */
2554 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2555 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2557 bombout(("Strange packet received: type %d", pktin.type));
2562 int len = min(inlen, 512);
2563 send_packet(SSH1_CMSG_STDIN_DATA,
2564 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2575 * Utility routine for decoding comma-separated strings in KEXINIT.
2577 static int in_commasep_string(char *needle, char *haystack, int haylen)
2579 int needlen = strlen(needle);
2582 * Is it at the start of the string?
2584 if (haylen >= needlen && /* haystack is long enough */
2585 !memcmp(needle, haystack, needlen) && /* initial match */
2586 (haylen == needlen || haystack[needlen] == ',')
2587 /* either , or EOS follows */
2591 * If not, search for the next comma and resume after that.
2592 * If no comma found, terminate.
2594 while (haylen > 0 && *haystack != ',')
2595 haylen--, haystack++;
2598 haylen--, haystack++; /* skip over comma itself */
2603 * SSH2 key creation method.
2605 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
2609 /* First 20 bytes. */
2612 SHA_Bytes(&s, H, 20);
2613 SHA_Bytes(&s, &chr, 1);
2614 SHA_Bytes(&s, sessid, 20);
2615 SHA_Final(&s, keyspace);
2616 /* Next 20 bytes. */
2619 SHA_Bytes(&s, H, 20);
2620 SHA_Bytes(&s, keyspace, 20);
2621 SHA_Final(&s, keyspace + 20);
2625 * Handle the SSH2 transport layer.
2627 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2629 static int i, j, len, nbits, pbits;
2631 static Bignum p, g, e, f, K;
2632 static int kex_init_value, kex_reply_value;
2633 static const struct ssh_mac **maclist;
2635 static const struct ssh2_cipher *cscipher_tobe = NULL;
2636 static const struct ssh2_cipher *sccipher_tobe = NULL;
2637 static const struct ssh_mac *csmac_tobe = NULL;
2638 static const struct ssh_mac *scmac_tobe = NULL;
2639 static const struct ssh_compress *cscomp_tobe = NULL;
2640 static const struct ssh_compress *sccomp_tobe = NULL;
2641 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2642 static int hostkeylen, siglen;
2643 static void *hkey; /* actual host key */
2644 static unsigned char exchange_hash[20];
2645 static unsigned char keyspace[40];
2646 static const struct ssh2_ciphers *preferred_cipher;
2647 static const struct ssh_compress *preferred_comp;
2648 static int first_kex;
2655 * Set up the preferred cipher and compression.
2657 if (cfg.cipher == CIPHER_BLOWFISH) {
2658 preferred_cipher = &ssh2_blowfish;
2659 } else if (cfg.cipher == CIPHER_DES) {
2660 logevent("Single DES not supported in SSH2; using 3DES");
2661 preferred_cipher = &ssh2_3des;
2662 } else if (cfg.cipher == CIPHER_3DES) {
2663 preferred_cipher = &ssh2_3des;
2664 } else if (cfg.cipher == CIPHER_AES) {
2665 preferred_cipher = &ssh2_aes;
2667 /* Shouldn't happen, but we do want to initialise to _something_. */
2668 preferred_cipher = &ssh2_3des;
2670 if (cfg.compression)
2671 preferred_comp = &ssh_zlib;
2673 preferred_comp = &ssh_comp_none;
2676 * Be prepared to work around the buggy MAC problem.
2678 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
2679 maclist = buggymacs, nmacs = lenof(buggymacs);
2681 maclist = macs, nmacs = lenof(macs);
2685 * Construct and send our key exchange packet.
2687 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2688 for (i = 0; i < 16; i++)
2689 ssh2_pkt_addbyte((unsigned char) random_byte());
2690 /* List key exchange algorithms. */
2691 ssh2_pkt_addstring_start();
2692 for (i = 0; i < lenof(kex_algs); i++) {
2693 ssh2_pkt_addstring_str(kex_algs[i]->name);
2694 if (i < lenof(kex_algs) - 1)
2695 ssh2_pkt_addstring_str(",");
2697 /* List server host key algorithms. */
2698 ssh2_pkt_addstring_start();
2699 for (i = 0; i < lenof(hostkey_algs); i++) {
2700 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2701 if (i < lenof(hostkey_algs) - 1)
2702 ssh2_pkt_addstring_str(",");
2704 /* List client->server encryption algorithms. */
2705 ssh2_pkt_addstring_start();
2706 for (i = 0; i < lenof(ciphers) + 1; i++) {
2707 const struct ssh2_ciphers *c =
2708 i == 0 ? preferred_cipher : ciphers[i - 1];
2709 for (j = 0; j < c->nciphers; j++) {
2710 ssh2_pkt_addstring_str(c->list[j]->name);
2711 if (i < lenof(ciphers) || j < c->nciphers - 1)
2712 ssh2_pkt_addstring_str(",");
2715 /* List server->client encryption algorithms. */
2716 ssh2_pkt_addstring_start();
2717 for (i = 0; i < lenof(ciphers) + 1; i++) {
2718 const struct ssh2_ciphers *c =
2719 i == 0 ? preferred_cipher : ciphers[i - 1];
2720 for (j = 0; j < c->nciphers; j++) {
2721 ssh2_pkt_addstring_str(c->list[j]->name);
2722 if (i < lenof(ciphers) || j < c->nciphers - 1)
2723 ssh2_pkt_addstring_str(",");
2726 /* List client->server MAC algorithms. */
2727 ssh2_pkt_addstring_start();
2728 for (i = 0; i < nmacs; i++) {
2729 ssh2_pkt_addstring_str(maclist[i]->name);
2731 ssh2_pkt_addstring_str(",");
2733 /* List server->client MAC algorithms. */
2734 ssh2_pkt_addstring_start();
2735 for (i = 0; i < nmacs; i++) {
2736 ssh2_pkt_addstring_str(maclist[i]->name);
2738 ssh2_pkt_addstring_str(",");
2740 /* List client->server compression algorithms. */
2741 ssh2_pkt_addstring_start();
2742 for (i = 0; i < lenof(compressions) + 1; i++) {
2743 const struct ssh_compress *c =
2744 i == 0 ? preferred_comp : compressions[i - 1];
2745 ssh2_pkt_addstring_str(c->name);
2746 if (i < lenof(compressions))
2747 ssh2_pkt_addstring_str(",");
2749 /* List server->client compression algorithms. */
2750 ssh2_pkt_addstring_start();
2751 for (i = 0; i < lenof(compressions) + 1; i++) {
2752 const struct ssh_compress *c =
2753 i == 0 ? preferred_comp : compressions[i - 1];
2754 ssh2_pkt_addstring_str(c->name);
2755 if (i < lenof(compressions))
2756 ssh2_pkt_addstring_str(",");
2758 /* List client->server languages. Empty list. */
2759 ssh2_pkt_addstring_start();
2760 /* List server->client languages. Empty list. */
2761 ssh2_pkt_addstring_start();
2762 /* First KEX packet does _not_ follow, because we're not that brave. */
2763 ssh2_pkt_addbool(FALSE);
2765 ssh2_pkt_adduint32(0);
2767 exhash = exhashbase;
2768 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
2774 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
2777 * Now examine the other side's KEXINIT to see what we're up
2780 if (pktin.type != SSH2_MSG_KEXINIT) {
2781 bombout(("expected key exchange packet from server"));
2786 cscipher_tobe = NULL;
2787 sccipher_tobe = NULL;
2792 pktin.savedpos += 16; /* skip garbage cookie */
2793 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2794 for (i = 0; i < lenof(kex_algs); i++) {
2795 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2800 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2801 for (i = 0; i < lenof(hostkey_algs); i++) {
2802 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2803 hostkey = hostkey_algs[i];
2807 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2808 for (i = 0; i < lenof(ciphers) + 1; i++) {
2809 const struct ssh2_ciphers *c =
2810 i == 0 ? preferred_cipher : ciphers[i - 1];
2811 for (j = 0; j < c->nciphers; j++) {
2812 if (in_commasep_string(c->list[j]->name, str, len)) {
2813 cscipher_tobe = c->list[j];
2820 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2821 for (i = 0; i < lenof(ciphers) + 1; i++) {
2822 const struct ssh2_ciphers *c =
2823 i == 0 ? preferred_cipher : ciphers[i - 1];
2824 for (j = 0; j < c->nciphers; j++) {
2825 if (in_commasep_string(c->list[j]->name, str, len)) {
2826 sccipher_tobe = c->list[j];
2833 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2834 for (i = 0; i < nmacs; i++) {
2835 if (in_commasep_string(maclist[i]->name, str, len)) {
2836 csmac_tobe = maclist[i];
2840 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2841 for (i = 0; i < nmacs; i++) {
2842 if (in_commasep_string(maclist[i]->name, str, len)) {
2843 scmac_tobe = maclist[i];
2847 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2848 for (i = 0; i < lenof(compressions) + 1; i++) {
2849 const struct ssh_compress *c =
2850 i == 0 ? preferred_comp : compressions[i - 1];
2851 if (in_commasep_string(c->name, str, len)) {
2856 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2857 for (i = 0; i < lenof(compressions) + 1; i++) {
2858 const struct ssh_compress *c =
2859 i == 0 ? preferred_comp : compressions[i - 1];
2860 if (in_commasep_string(c->name, str, len)) {
2867 * Work out the number of bits of key we will need from the key
2868 * exchange. We start with the maximum key length of either
2874 csbits = cscipher_tobe->keylen;
2875 scbits = sccipher_tobe->keylen;
2876 nbits = (csbits > scbits ? csbits : scbits);
2878 /* The keys only have 160-bit entropy, since they're based on
2879 * a SHA-1 hash. So cap the key size at 160 bits. */
2884 * If we're doing Diffie-Hellman group exchange, start by
2885 * requesting a group.
2887 if (kex == &ssh_diffiehellman_gex) {
2888 logevent("Doing Diffie-Hellman group exchange");
2890 * Work out how big a DH group we will need to allow that
2893 pbits = 512 << ((nbits - 1) / 64);
2894 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2895 ssh2_pkt_adduint32(pbits);
2899 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2900 bombout(("expected key exchange group packet from server"));
2903 p = ssh2_pkt_getmp();
2904 g = ssh2_pkt_getmp();
2905 dh_setup_group(p, g);
2906 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2907 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2910 kex_init_value = SSH2_MSG_KEXDH_INIT;
2911 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
2914 logevent("Doing Diffie-Hellman key exchange");
2916 * Now generate and send e for Diffie-Hellman.
2918 e = dh_create_e(nbits * 2);
2919 ssh2_pkt_init(kex_init_value);
2924 if (pktin.type != kex_reply_value) {
2925 bombout(("expected key exchange reply packet from server"));
2928 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2929 f = ssh2_pkt_getmp();
2930 ssh2_pkt_getstring(&sigdata, &siglen);
2934 sha_string(&exhash, hostkeydata, hostkeylen);
2935 if (kex == &ssh_diffiehellman_gex) {
2936 sha_uint32(&exhash, pbits);
2937 sha_mpint(&exhash, p);
2938 sha_mpint(&exhash, g);
2940 sha_mpint(&exhash, e);
2941 sha_mpint(&exhash, f);
2942 sha_mpint(&exhash, K);
2943 SHA_Final(&exhash, exchange_hash);
2948 debug(("Exchange hash is:\n"));
2949 dmemdump(exchange_hash, 20);
2952 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2953 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2954 bombout(("Server failed host key check"));
2959 * Expect SSH2_MSG_NEWKEYS from server.
2962 if (pktin.type != SSH2_MSG_NEWKEYS) {
2963 bombout(("expected new-keys packet from server"));
2968 * Authenticate remote host: verify host key. (We've already
2969 * checked the signature of the exchange hash.)
2971 keystr = hostkey->fmtkey(hkey);
2972 fingerprint = hostkey->fingerprint(hkey);
2973 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2974 keystr, fingerprint);
2975 if (first_kex) { /* don't bother logging this in rekeys */
2976 logevent("Host key fingerprint is:");
2977 logevent(fingerprint);
2981 hostkey->freekey(hkey);
2984 * Send SSH2_MSG_NEWKEYS.
2986 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2990 * Create and initialise session keys.
2992 cscipher = cscipher_tobe;
2993 sccipher = sccipher_tobe;
2996 cscomp = cscomp_tobe;
2997 sccomp = sccomp_tobe;
2998 cscomp->compress_init();
2999 sccomp->decompress_init();
3001 * Set IVs after keys. Here we use the exchange hash from the
3002 * _first_ key exchange.
3005 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3006 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3007 cscipher->setcskey(keyspace);
3008 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3009 sccipher->setsckey(keyspace);
3010 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3011 cscipher->setcsiv(keyspace);
3012 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3013 sccipher->setsciv(keyspace);
3014 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3015 csmac->setcskey(keyspace);
3016 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3017 scmac->setsckey(keyspace);
3020 * If this is the first key exchange phase, we must pass the
3021 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3022 * wants to see it but because it will need time to initialise
3023 * itself before it sees an actual packet. In subsequent key
3024 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3025 * it would only confuse the layer above.
3033 * Now we're encrypting. Begin returning 1 to the protocol main
3034 * function so that other things can run on top of the
3035 * transport. If we ever see a KEXINIT, we must go back to the
3038 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3041 logevent("Server initiated key re-exchange");
3042 goto begin_key_exchange;
3048 * Add data to an SSH2 channel output buffer.
3050 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3053 if (c->v2.outbufsize < c->v2.outbuflen + len) {
3054 c->v2.outbufsize = c->v2.outbuflen + len + 1024;
3055 c->v2.outbuffer = srealloc(c->v2.outbuffer, c->v2.outbufsize);
3057 memcpy(c->v2.outbuffer + c->v2.outbuflen, buf, len);
3058 c->v2.outbuflen += len;
3062 * Attempt to send data on an SSH2 channel.
3064 static void ssh2_try_send(struct ssh_channel *c)
3066 while (c->v2.remwindow > 0 && c->v2.outbuflen > 0) {
3067 unsigned len = c->v2.remwindow;
3068 if (len > c->v2.outbuflen)
3069 len = c->v2.outbuflen;
3070 if (len > c->v2.remmaxpkt)
3071 len = c->v2.remmaxpkt;
3072 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3073 ssh2_pkt_adduint32(c->remoteid);
3074 ssh2_pkt_addstring_start();
3075 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
3077 c->v2.outbuflen -= len;
3078 memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
3079 c->v2.remwindow -= len;
3084 * Handle the SSH2 userauth and connection layers.
3086 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3088 static unsigned long remote_winsize;
3089 static unsigned long remote_maxpkt;
3091 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3096 AUTH_TYPE_PUBLICKEY,
3097 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3098 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3101 static int gotit, need_pw, can_pubkey, can_passwd;
3102 static int tried_pubkey_config, tried_agent;
3103 static int we_are_in;
3104 static char username[100];
3105 static char pwprompt[200];
3106 static char password[100];
3111 * Request userauth protocol, and await a response to it.
3113 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3114 ssh2_pkt_addstring("ssh-userauth");
3116 crWaitUntilV(ispkt);
3117 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3118 bombout(("Server refused user authentication protocol"));
3123 * We repeat this whole loop, including the username prompt,
3124 * until we manage a successful authentication. If the user
3125 * types the wrong _password_, they are sent back to the
3126 * beginning to try another username. (If they specify a
3127 * username in the config, they are never asked, even if they
3128 * do give a wrong password.)
3130 * I think this best serves the needs of
3132 * - the people who have no configuration, no keys, and just
3133 * want to try repeated (username,password) pairs until they
3134 * type both correctly
3136 * - people who have keys and configuration but occasionally
3137 * need to fall back to passwords
3139 * - people with a key held in Pageant, who might not have
3140 * logged in to a particular machine before; so they want to
3141 * type a username, and then _either_ their key will be
3142 * accepted, _or_ they will type a password. If they mistype
3143 * the username they will want to be able to get back and
3154 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3156 if (!ssh_get_line("login as: ",
3157 username, sizeof(username), FALSE)) {
3159 * get_line failed to get a username.
3162 logevent("No username provided. Abandoning session.");
3163 ssh_state = SSH_STATE_CLOSED;
3167 c_write_str("login as: ");
3170 crWaitUntilV(!ispkt);
3172 switch (c = *in++) {
3181 c_write_str("\b \b");
3188 c_write_str("\b \b");
3198 if (((c >= ' ' && c <= '~') ||
3199 ((unsigned char) c >= 160))
3200 && pos < sizeof(username)-1) {
3201 username[pos++] = c;
3208 c_write_str("\r\n");
3209 username[strcspn(username, "\n\r")] = '\0';
3212 strncpy(username, cfg.username, 99);
3213 username[99] = '\0';
3214 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3215 sprintf(stuff, "Using username \"%s\".\r\n", username);
3221 * Send an authentication request using method "none": (a)
3222 * just in case it succeeds, and (b) so that we know what
3223 * authentication methods we can usefully try next.
3225 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3226 ssh2_pkt_addstring(username);
3227 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3228 ssh2_pkt_addstring("none"); /* method */
3230 type = AUTH_TYPE_NONE;
3234 tried_pubkey_config = FALSE;
3235 tried_agent = FALSE;
3239 * Wait for the result of the last authentication request.
3242 crWaitUntilV(ispkt);
3243 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3247 * Don't show the banner if we're operating in
3248 * non-verbose non-interactive mode. (It's probably
3249 * a script, which means nobody will read the
3250 * banner _anyway_, and moreover the printing of
3251 * the banner will screw up processing on the
3252 * output of (say) plink.)
3254 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3255 ssh2_pkt_getstring(&banner, &size);
3257 c_write_untrusted(banner, size);
3259 crWaitUntilV(ispkt);
3261 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3262 logevent("Access granted");
3267 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3269 ("Strange packet received during authentication: type %d",
3277 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3278 * we can look at the string in it and know what we can
3279 * helpfully try next.
3284 ssh2_pkt_getstring(&methods, &methlen);
3285 if (!ssh2_pkt_getbool()) {
3287 * We have received an unequivocal Access
3288 * Denied. This can translate to a variety of
3291 * - if we'd just tried "none" authentication,
3292 * it's not worth printing anything at all
3294 * - if we'd just tried a public key _offer_,
3295 * the message should be "Server refused our
3296 * key" (or no message at all if the key
3297 * came from Pageant)
3299 * - if we'd just tried anything else, the
3300 * message really should be "Access denied".
3302 * Additionally, if we'd just tried password
3303 * authentication, we should break out of this
3304 * whole loop so as to go back to the username
3307 if (type == AUTH_TYPE_NONE) {
3309 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3310 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3311 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3312 c_write_str("Server refused our key\r\n");
3313 logevent("Server refused public key");
3315 c_write_str("Access denied\r\n");
3316 logevent("Access denied");
3317 if (type == AUTH_TYPE_PASSWORD) {
3323 c_write_str("Further authentication required\r\n");
3324 logevent("Further authentication required");
3328 in_commasep_string("publickey", methods, methlen);
3330 in_commasep_string("password", methods, methlen);
3335 if (!method && can_pubkey && agent_exists() && !tried_agent) {
3337 * Attempt public-key authentication using Pageant.
3339 static unsigned char request[5], *response, *p;
3340 static int responselen;
3341 static int i, nkeys;
3342 static int authed = FALSE;
3347 logevent("Pageant is running. Requesting keys.");
3349 /* Request the keys held by the agent. */
3350 PUT_32BIT(request, 1);
3351 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3352 agent_query(request, 5, &r, &responselen);
3353 response = (unsigned char *) r;
3354 if (response && responselen >= 5 &&
3355 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3357 nkeys = GET_32BIT(p);
3361 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3364 for (i = 0; i < nkeys; i++) {
3365 static char *pkblob, *alg, *commentp;
3366 static int pklen, alglen, commentlen;
3367 static int siglen, retlen, len;
3368 static char *q, *agentreq, *ret;
3372 sprintf(buf, "Trying Pageant key #%d", i);
3375 pklen = GET_32BIT(p);
3379 alglen = GET_32BIT(pkblob);
3381 commentlen = GET_32BIT(p);
3385 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3386 ssh2_pkt_addstring(username);
3387 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3388 ssh2_pkt_addstring("publickey"); /* method */
3389 ssh2_pkt_addbool(FALSE); /* no signature included */
3390 ssh2_pkt_addstring_start();
3391 ssh2_pkt_addstring_data(alg, alglen);
3392 ssh2_pkt_addstring_start();
3393 ssh2_pkt_addstring_data(pkblob, pklen);
3396 crWaitUntilV(ispkt);
3397 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3398 logevent("Key refused");
3402 if (flags & FLAG_VERBOSE) {
3404 ("Authenticating with public key \"");
3405 c_write(commentp, commentlen);
3406 c_write_str("\" from agent\r\n");
3410 * Server is willing to accept the key.
3411 * Construct a SIGN_REQUEST.
3413 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3414 ssh2_pkt_addstring(username);
3415 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3416 ssh2_pkt_addstring("publickey"); /* method */
3417 ssh2_pkt_addbool(TRUE);
3418 ssh2_pkt_addstring_start();
3419 ssh2_pkt_addstring_data(alg, alglen);
3420 ssh2_pkt_addstring_start();
3421 ssh2_pkt_addstring_data(pkblob, pklen);
3423 siglen = pktout.length - 5 + 4 + 20;
3424 len = 1; /* message type */
3425 len += 4 + pklen; /* key blob */
3426 len += 4 + siglen; /* data to sign */
3427 len += 4; /* flags */
3428 agentreq = smalloc(4 + len);
3429 PUT_32BIT(agentreq, len);
3431 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3432 PUT_32BIT(q, pklen);
3434 memcpy(q, pkblob, pklen);
3436 PUT_32BIT(q, siglen);
3438 /* Now the data to be signed... */
3441 memcpy(q, ssh2_session_id, 20);
3443 memcpy(q, pktout.data + 5, pktout.length - 5);
3444 q += pktout.length - 5;
3445 /* And finally the (zero) flags word. */
3447 agent_query(agentreq, len + 4, &ret, &retlen);
3450 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3451 logevent("Sending Pageant's response");
3452 ssh2_pkt_addstring_start();
3453 ssh2_pkt_addstring_data(ret + 9,
3461 ("Pageant failed to answer challenge");
3471 if (!method && can_pubkey && *cfg.keyfile
3472 && !tried_pubkey_config) {
3473 unsigned char *pub_blob;
3474 char *algorithm, *comment;
3477 tried_pubkey_config = TRUE;
3480 * Try the public key supplied in the configuration.
3482 * First, offer the public blob to see if the server is
3483 * willing to accept it.
3485 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3488 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3489 ssh2_pkt_addstring(username);
3490 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3491 ssh2_pkt_addstring("publickey"); /* method */
3492 ssh2_pkt_addbool(FALSE); /* no signature included */
3493 ssh2_pkt_addstring(algorithm);
3494 ssh2_pkt_addstring_start();
3495 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3497 logevent("Offered public key"); /* FIXME */
3499 crWaitUntilV(ispkt);
3500 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3502 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3503 continue; /* key refused; give up on it */
3506 logevent("Offer of public key accepted");
3508 * Actually attempt a serious authentication using
3511 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3513 "Passphrase for key \"%.100s\": ",
3519 c_write_str("Authenticating with public key \"");
3520 c_write_str(comment);
3521 c_write_str("\"\r\n");
3522 method = AUTH_PUBLICKEY_FILE;
3526 if (!method && can_passwd) {
3527 method = AUTH_PASSWORD;
3528 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
3535 if (!ssh_get_line(pwprompt, password,
3536 sizeof(password), TRUE)) {
3538 * get_line failed to get a password (for
3539 * example because one was supplied on the
3540 * command line which has already failed to
3543 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3544 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3546 ("No more passwords available to try");
3547 ssh2_pkt_addstring("en"); /* language tag */
3549 connection_fatal("Unable to authenticate");
3550 ssh_state = SSH_STATE_CLOSED;
3557 c_write_str(pwprompt);
3562 crWaitUntilV(!ispkt);
3564 switch (c = *in++) {
3585 if (pos < sizeof(password)-1)
3586 password[pos++] = c;
3590 c_write_str("\r\n");
3594 if (method == AUTH_PUBLICKEY_FILE) {
3596 * We have our passphrase. Now try the actual authentication.
3598 struct ssh2_userkey *key;
3600 key = ssh2_load_userkey(cfg.keyfile, password);
3601 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3602 if (key == SSH2_WRONG_PASSPHRASE) {
3603 c_write_str("Wrong passphrase\r\n");
3604 tried_pubkey_config = FALSE;
3606 c_write_str("Unable to load private key\r\n");
3607 tried_pubkey_config = TRUE;
3609 /* Send a spurious AUTH_NONE to return to the top. */
3610 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3611 ssh2_pkt_addstring(username);
3612 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3613 ssh2_pkt_addstring("none"); /* method */
3615 type = AUTH_TYPE_NONE;
3617 unsigned char *blob, *sigdata;
3618 int blob_len, sigdata_len;
3621 * We have loaded the private key and the server
3622 * has announced that it's willing to accept it.
3623 * Hallelujah. Generate a signature and send it.
3625 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3626 ssh2_pkt_addstring(username);
3627 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3628 ssh2_pkt_addstring("publickey"); /* method */
3629 ssh2_pkt_addbool(TRUE);
3630 ssh2_pkt_addstring(key->alg->name);
3631 blob = key->alg->public_blob(key->data, &blob_len);
3632 ssh2_pkt_addstring_start();
3633 ssh2_pkt_addstring_data(blob, blob_len);
3637 * The data to be signed is:
3641 * followed by everything so far placed in the
3644 sigdata_len = pktout.length - 5 + 4 + 20;
3645 sigdata = smalloc(sigdata_len);
3646 PUT_32BIT(sigdata, 20);
3647 memcpy(sigdata + 4, ssh2_session_id, 20);
3648 memcpy(sigdata + 24, pktout.data + 5,
3651 key->alg->sign(key->data, sigdata, sigdata_len,
3653 ssh2_pkt_addstring_start();
3654 ssh2_pkt_addstring_data(blob, blob_len);
3659 type = AUTH_TYPE_PUBLICKEY;
3661 } else if (method == AUTH_PASSWORD) {
3663 * We send the password packet lumped tightly together with
3664 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3665 * string long enough to make the total length of the two
3666 * packets constant. This should ensure that a passive
3667 * listener doing traffic analyis can't work out the length
3670 * For this to work, we need an assumption about the
3671 * maximum length of the password packet. I think 256 is
3672 * pretty conservative. Anyone using a password longer than
3673 * that probably doesn't have much to worry about from
3674 * people who find out how long their password is!
3676 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3677 ssh2_pkt_addstring(username);
3678 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3679 ssh2_pkt_addstring("password");
3680 ssh2_pkt_addbool(FALSE);
3681 ssh2_pkt_addstring(password);
3684 * We'll include a string that's an exact multiple of the
3685 * cipher block size. If the cipher is NULL for some
3686 * reason, we don't do this trick at all because we gain
3692 stringlen = (256 - deferred_len);
3693 stringlen += cscipher->blksize - 1;
3694 stringlen -= (stringlen % cscipher->blksize);
3697 * Temporarily disable actual compression,
3698 * so we can guarantee to get this string
3699 * exactly the length we want it. The
3700 * compression-disabling routine should
3701 * return an integer indicating how many
3702 * bytes we should adjust our string length
3705 stringlen -= cscomp->disable_compression();
3707 ssh2_pkt_init(SSH2_MSG_IGNORE);
3708 ssh2_pkt_addstring_start();
3709 for (i = 0; i < stringlen; i++) {
3710 char c = (char) random_byte();
3711 ssh2_pkt_addstring_data(&c, 1);
3715 ssh_pkt_defersend();
3716 logevent("Sent password");
3717 type = AUTH_TYPE_PASSWORD;
3720 ("No supported authentication methods left to try!\r\n");
3722 ("No supported authentications offered. Disconnecting");
3723 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3724 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3726 ("No supported authentication methods available");
3727 ssh2_pkt_addstring("en"); /* language tag */
3729 ssh_state = SSH_STATE_CLOSED;
3733 } while (!we_are_in);
3736 * Now we're authenticated for the connection protocol. The
3737 * connection protocol will automatically have started at this
3738 * point; there's no need to send SERVICE_REQUEST.
3742 * So now create a channel with a session in it.
3744 ssh_channels = newtree234(ssh_channelcmp);
3745 mainchan = smalloc(sizeof(struct ssh_channel));
3746 mainchan->localid = alloc_channel_id();
3747 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3748 ssh2_pkt_addstring("session");
3749 ssh2_pkt_adduint32(mainchan->localid);
3750 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3751 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3753 crWaitUntilV(ispkt);
3754 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
3755 bombout(("Server refused to open a session"));
3757 /* FIXME: error data comes back in FAILURE packet */
3759 if (ssh2_pkt_getuint32() != mainchan->localid) {
3760 bombout(("Server's channel confirmation cited wrong channel"));
3763 mainchan->remoteid = ssh2_pkt_getuint32();
3764 mainchan->type = CHAN_MAINSESSION;
3765 mainchan->closes = 0;
3766 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3767 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3768 mainchan->v2.outbuffer = NULL;
3769 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3770 add234(ssh_channels, mainchan);
3771 logevent("Opened channel for session");
3774 * Potentially enable X11 forwarding.
3776 if (cfg.x11_forward) {
3777 char proto[20], data[64];
3778 logevent("Requesting X11 forwarding");
3779 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3780 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3781 ssh2_pkt_adduint32(mainchan->remoteid);
3782 ssh2_pkt_addstring("x11-req");
3783 ssh2_pkt_addbool(1); /* want reply */
3784 ssh2_pkt_addbool(0); /* many connections */
3785 ssh2_pkt_addstring(proto);
3786 ssh2_pkt_addstring(data);
3787 ssh2_pkt_adduint32(0); /* screen number */
3791 crWaitUntilV(ispkt);
3792 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3793 unsigned i = ssh2_pkt_getuint32();
3794 struct ssh_channel *c;
3795 c = find234(ssh_channels, &i, ssh_channelfind);
3797 continue; /* nonexistent channel */
3798 c->v2.remwindow += ssh2_pkt_getuint32();
3800 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3802 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3803 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3804 bombout(("Server got confused by X11 forwarding request"));
3807 logevent("X11 forwarding refused");
3809 logevent("X11 forwarding enabled");
3810 ssh_X11_fwd_enabled = TRUE;
3815 * Potentially enable agent forwarding.
3817 if (cfg.agentfwd && agent_exists()) {
3818 logevent("Requesting OpenSSH-style agent forwarding");
3819 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3820 ssh2_pkt_adduint32(mainchan->remoteid);
3821 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3822 ssh2_pkt_addbool(1); /* want reply */
3826 crWaitUntilV(ispkt);
3827 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3828 unsigned i = ssh2_pkt_getuint32();
3829 struct ssh_channel *c;
3830 c = find234(ssh_channels, &i, ssh_channelfind);
3832 continue; /* nonexistent channel */
3833 c->v2.remwindow += ssh2_pkt_getuint32();
3835 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3837 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3838 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3840 ("Server got confused by agent forwarding request"));
3843 logevent("Agent forwarding refused");
3845 logevent("Agent forwarding enabled");
3846 ssh_agentfwd_enabled = TRUE;
3851 * Now allocate a pty for the session.
3854 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3855 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3856 ssh2_pkt_addstring("pty-req");
3857 ssh2_pkt_addbool(1); /* want reply */
3858 ssh2_pkt_addstring(cfg.termtype);
3859 ssh2_pkt_adduint32(cols);
3860 ssh2_pkt_adduint32(rows);
3861 ssh2_pkt_adduint32(0); /* pixel width */
3862 ssh2_pkt_adduint32(0); /* pixel height */
3863 ssh2_pkt_addstring_start();
3864 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
3866 ssh_state = SSH_STATE_INTERMED;
3869 crWaitUntilV(ispkt);
3870 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3871 unsigned i = ssh2_pkt_getuint32();
3872 struct ssh_channel *c;
3873 c = find234(ssh_channels, &i, ssh_channelfind);
3875 continue; /* nonexistent channel */
3876 c->v2.remwindow += ssh2_pkt_getuint32();
3878 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3880 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3881 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3882 bombout(("Server got confused by pty request"));
3885 c_write_str("Server refused to allocate pty\r\n");
3886 ssh_editing = ssh_echoing = 1;
3888 logevent("Allocated pty");
3891 ssh_editing = ssh_echoing = 1;
3895 * Start a shell or a remote command.
3897 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3898 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3899 if (cfg.ssh_subsys) {
3900 ssh2_pkt_addstring("subsystem");
3901 ssh2_pkt_addbool(1); /* want reply */
3902 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
3903 } else if (*cfg.remote_cmd_ptr) {
3904 ssh2_pkt_addstring("exec");
3905 ssh2_pkt_addbool(1); /* want reply */
3906 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
3908 ssh2_pkt_addstring("shell");
3909 ssh2_pkt_addbool(1); /* want reply */
3913 crWaitUntilV(ispkt);
3914 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3915 unsigned i = ssh2_pkt_getuint32();
3916 struct ssh_channel *c;
3917 c = find234(ssh_channels, &i, ssh_channelfind);
3919 continue; /* nonexistent channel */
3920 c->v2.remwindow += ssh2_pkt_getuint32();
3922 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3923 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3924 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3925 bombout(("Server got confused by shell/command request"));
3928 bombout(("Server refused to start a shell/command"));
3931 logevent("Started a shell/command");
3934 ssh_state = SSH_STATE_SESSION;
3938 ssh_special(TS_EOF);
3943 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
3946 static int try_send;
3950 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3951 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3954 unsigned i = ssh2_pkt_getuint32();
3955 struct ssh_channel *c;
3956 c = find234(ssh_channels, &i, ssh_channelfind);
3958 continue; /* nonexistent channel */
3959 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3960 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3961 continue; /* extended but not stderr */
3962 ssh2_pkt_getstring(&data, &length);
3965 case CHAN_MAINSESSION:
3966 from_backend(pktin.type ==
3967 SSH2_MSG_CHANNEL_EXTENDED_DATA, data,
3971 x11_send(c->u.x11.s, data, length);
3974 while (length > 0) {
3975 if (c->u.a.lensofar < 4) {
3976 int l = min(4 - c->u.a.lensofar, length);
3977 memcpy(c->u.a.msglen + c->u.a.lensofar,
3981 c->u.a.lensofar += l;
3983 if (c->u.a.lensofar == 4) {
3985 4 + GET_32BIT(c->u.a.msglen);
3986 c->u.a.message = smalloc(c->u.a.totallen);
3987 memcpy(c->u.a.message, c->u.a.msglen, 4);
3989 if (c->u.a.lensofar >= 4 && length > 0) {
3991 min(c->u.a.totallen - c->u.a.lensofar,
3993 memcpy(c->u.a.message + c->u.a.lensofar,
3997 c->u.a.lensofar += l;
3999 if (c->u.a.lensofar == c->u.a.totallen) {
4000 void *reply, *sentreply;
4002 agent_query(c->u.a.message,
4003 c->u.a.totallen, &reply,
4008 /* Fake SSH_AGENT_FAILURE. */
4009 sentreply = "\0\0\0\1\5";
4012 ssh2_add_channel_data(c, sentreply,
4017 sfree(c->u.a.message);
4018 c->u.a.lensofar = 0;
4024 * Enlarge the window again at the remote
4025 * side, just in case it ever runs down and
4026 * they fail to send us any more data.
4028 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4029 ssh2_pkt_adduint32(c->remoteid);
4030 ssh2_pkt_adduint32(length);
4033 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4034 ssh_state = SSH_STATE_CLOSED;
4035 logevent("Received disconnect message");
4037 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
4038 continue; /* exit status et al; ignore (FIXME?) */
4039 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4040 unsigned i = ssh2_pkt_getuint32();
4041 struct ssh_channel *c;
4043 c = find234(ssh_channels, &i, ssh_channelfind);
4045 continue; /* nonexistent channel */
4047 if (c->type == CHAN_X11) {
4049 * Remote EOF on an X11 channel means we should
4050 * wrap up and close the channel ourselves.
4052 x11_close(c->u.x11.s);
4054 } else if (c->type == CHAN_AGENT) {
4057 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4058 unsigned i = ssh2_pkt_getuint32();
4059 struct ssh_channel *c;
4061 c = find234(ssh_channels, &i, ssh_channelfind);
4063 continue; /* nonexistent channel */
4064 if (c->closes == 0) {
4065 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4066 ssh2_pkt_adduint32(c->remoteid);
4069 /* Do pre-close processing on the channel. */
4071 case CHAN_MAINSESSION:
4072 break; /* nothing to see here, move along */
4078 del234(ssh_channels, c);
4079 sfree(c->v2.outbuffer);
4083 * See if that was the last channel left open.
4085 if (count234(ssh_channels) == 0) {
4086 logevent("All channels closed. Disconnecting");
4087 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4088 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4089 ssh2_pkt_addstring("All open channels closed");
4090 ssh2_pkt_addstring("en"); /* language tag */
4092 ssh_state = SSH_STATE_CLOSED;
4095 continue; /* remote sends close; ignore (FIXME) */
4096 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4097 unsigned i = ssh2_pkt_getuint32();
4098 struct ssh_channel *c;
4099 c = find234(ssh_channels, &i, ssh_channelfind);
4101 continue; /* nonexistent channel */
4102 c->v2.remwindow += ssh2_pkt_getuint32();
4104 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
4108 struct ssh_channel *c;
4109 ssh2_pkt_getstring(&type, &typelen);
4110 c = smalloc(sizeof(struct ssh_channel));
4112 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4113 if (!ssh_X11_fwd_enabled)
4114 error = "X11 forwarding is not enabled";
4115 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4117 error = "Unable to open an X11 connection";
4121 } else if (typelen == 22 &&
4122 !memcmp(type, "auth-agent@openssh.com", 3)) {
4123 if (!ssh_agentfwd_enabled)
4124 error = "Agent forwarding is not enabled";
4126 c->type = CHAN_AGENT; /* identify channel type */
4127 c->u.a.lensofar = 0;
4130 error = "Unsupported channel type requested";
4133 c->remoteid = ssh2_pkt_getuint32();
4135 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4136 ssh2_pkt_adduint32(c->remoteid);
4137 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4138 ssh2_pkt_addstring(error);
4139 ssh2_pkt_addstring("en"); /* language tag */
4143 c->localid = alloc_channel_id();
4145 c->v2.remwindow = ssh2_pkt_getuint32();
4146 c->v2.remmaxpkt = ssh2_pkt_getuint32();
4147 c->v2.outbuffer = NULL;
4148 c->v2.outbuflen = c->v2.outbufsize = 0;
4149 add234(ssh_channels, c);
4150 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4151 ssh2_pkt_adduint32(c->remoteid);
4152 ssh2_pkt_adduint32(c->localid);
4153 ssh2_pkt_adduint32(0x8000UL); /* our window size */
4154 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4158 bombout(("Strange packet received: type %d", pktin.type));
4163 * We have spare data. Add it to the channel buffer.
4165 ssh2_add_channel_data(mainchan, in, inlen);
4170 struct ssh_channel *c;
4172 * Try to send data on all channels if we can.
4174 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
4183 * Handle the top-level SSH2 protocol.
4185 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4187 if (do_ssh2_transport(in, inlen, ispkt) == 0)
4189 do_ssh2_authconn(in, inlen, ispkt);
4193 * Called to set up the connection.
4195 * Returns an error message, or NULL on success.
4197 static char *ssh_init(char *host, int port, char **realhost)
4202 if (crypto_startup() == 0)
4203 return "Microsoft high encryption pack not installed!";
4210 p = connect_to_host(host, port, realhost);
4218 * Called to send data down the Telnet connection.
4220 static void ssh_send(char *buf, int len)
4222 if (s == NULL || ssh_protocol == NULL)
4225 ssh_protocol(buf, len, 0);
4229 * Called to set the size of the window from SSH's POV.
4231 static void ssh_size(void)
4233 switch (ssh_state) {
4234 case SSH_STATE_BEFORE_SIZE:
4235 case SSH_STATE_PREPACKET:
4236 case SSH_STATE_CLOSED:
4237 break; /* do nothing */
4238 case SSH_STATE_INTERMED:
4239 size_needed = TRUE; /* buffer for later */
4241 case SSH_STATE_SESSION:
4243 if (ssh_version == 1) {
4244 send_packet(SSH1_CMSG_WINDOW_SIZE,
4245 PKT_INT, rows, PKT_INT, cols,
4246 PKT_INT, 0, PKT_INT, 0, PKT_END);
4248 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4249 ssh2_pkt_adduint32(mainchan->remoteid);
4250 ssh2_pkt_addstring("window-change");
4251 ssh2_pkt_addbool(0);
4252 ssh2_pkt_adduint32(cols);
4253 ssh2_pkt_adduint32(rows);
4254 ssh2_pkt_adduint32(0);
4255 ssh2_pkt_adduint32(0);
4264 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4265 * can send an EOF and collect resulting output (e.g. `plink
4268 static void ssh_special(Telnet_Special code)
4270 if (code == TS_EOF) {
4271 if (ssh_state != SSH_STATE_SESSION) {
4273 * Buffer the EOF in case we are pre-SESSION, so we can
4274 * send it as soon as we reach SESSION.
4280 if (ssh_version == 1) {
4281 send_packet(SSH1_CMSG_EOF, PKT_END);
4283 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4284 ssh2_pkt_adduint32(mainchan->remoteid);
4287 logevent("Sent EOF message");
4288 } else if (code == TS_PING) {
4289 if (ssh_state == SSH_STATE_CLOSED
4290 || ssh_state == SSH_STATE_PREPACKET) return;
4291 if (ssh_version == 1) {
4292 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
4294 ssh2_pkt_init(SSH2_MSG_IGNORE);
4295 ssh2_pkt_addstring_start();
4303 static Socket ssh_socket(void)
4308 static int ssh_sendok(void)
4313 static int ssh_ldisc(int option)
4315 if (option == LD_ECHO)
4317 if (option == LD_EDIT)
4322 Backend ssh_backend = {