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;
1486 /* A socket error has occurred. */
1487 connection_fatal(error_msg);
1489 /* Otherwise, the remote side closed the connection normally. */
1494 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1496 ssh_gotdata(data, len);
1497 if (ssh_state == SSH_STATE_CLOSED) {
1508 * Connect to specified host and port.
1509 * Returns an error message, or NULL on success.
1510 * Also places the canonical host name into `realhost'. It must be
1511 * freed by the caller.
1513 static char *connect_to_host(char *host, int port, char **realhost)
1515 static struct plug_function_table fn_table = {
1518 }, *fn_table_ptr = &fn_table;
1527 savedhost = smalloc(1 + strlen(host));
1529 fatalbox("Out of memory");
1530 strcpy(savedhost, host);
1533 port = 22; /* default ssh port */
1546 addr = sk_namelookup(host, realhost);
1547 if ((err = sk_addr_error(addr)))
1551 *realhost = strdup(FWhost);
1557 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1558 if ((err = sk_socket_error(s)))
1562 sk_write(s, "connect ", 8);
1563 sk_write(s, FWhost, strlen(FWhost));
1566 sprintf(buf, " %d\n", FWport);
1567 sk_write(s, buf, strlen(buf));
1575 * Handle the key exchange and user authentication phases.
1577 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1581 static unsigned char *rsabuf, *keystr1, *keystr2;
1582 unsigned char cookie[8];
1583 struct RSAKey servkey, hostkey;
1584 struct MD5Context md5c;
1585 static unsigned long supported_ciphers_mask, supported_auths_mask;
1586 static int tried_publickey;
1587 static unsigned char session_id[16];
1588 static int cipher_type;
1589 static char username[100];
1596 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1597 bombout(("Public key packet not received"));
1601 logevent("Received public keys");
1603 memcpy(cookie, pktin.body, 8);
1605 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1606 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1609 * Log the host key fingerprint.
1613 logevent("Host key fingerprint is:");
1614 strcpy(logmsg, " ");
1615 hostkey.comment = NULL;
1616 rsa_fingerprint(logmsg + strlen(logmsg),
1617 sizeof(logmsg) - strlen(logmsg), &hostkey);
1621 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1622 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1623 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1625 ssh1_local_protoflags =
1626 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1627 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1630 MD5Update(&md5c, keystr2, hostkey.bytes);
1631 MD5Update(&md5c, keystr1, servkey.bytes);
1632 MD5Update(&md5c, pktin.body, 8);
1633 MD5Final(session_id, &md5c);
1635 for (i = 0; i < 32; i++)
1636 session_key[i] = random_byte();
1638 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1640 rsabuf = smalloc(len);
1642 fatalbox("Out of memory");
1645 * Verify the host key.
1649 * First format the key into a string.
1651 int len = rsastr_len(&hostkey);
1652 char fingerprint[100];
1653 char *keystr = smalloc(len);
1655 fatalbox("Out of memory");
1656 rsastr_fmt(keystr, &hostkey);
1657 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1658 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1663 for (i = 0; i < 32; i++) {
1664 rsabuf[i] = session_key[i];
1666 rsabuf[i] ^= session_id[i];
1669 if (hostkey.bytes > servkey.bytes) {
1670 rsaencrypt(rsabuf, 32, &servkey);
1671 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1673 rsaencrypt(rsabuf, 32, &hostkey);
1674 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1677 logevent("Encrypted session key");
1679 switch (cfg.cipher) {
1680 case CIPHER_BLOWFISH:
1681 cipher_type = SSH_CIPHER_BLOWFISH;
1684 cipher_type = SSH_CIPHER_DES;
1687 cipher_type = SSH_CIPHER_3DES;
1690 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1691 cipher_type = SSH_CIPHER_3DES;
1694 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1696 ("Selected cipher not supported, falling back to 3DES\r\n");
1697 cipher_type = SSH_CIPHER_3DES;
1698 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1699 bombout(("Server violates SSH 1 protocol by "
1700 "not supporting 3DES encryption"));
1704 switch (cipher_type) {
1705 case SSH_CIPHER_3DES:
1706 logevent("Using 3DES encryption");
1708 case SSH_CIPHER_DES:
1709 logevent("Using single-DES encryption");
1711 case SSH_CIPHER_BLOWFISH:
1712 logevent("Using Blowfish encryption");
1716 send_packet(SSH1_CMSG_SESSION_KEY,
1717 PKT_CHAR, cipher_type,
1718 PKT_DATA, cookie, 8,
1719 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1720 PKT_DATA, rsabuf, len,
1721 PKT_INT, ssh1_local_protoflags, PKT_END);
1723 logevent("Trying to enable encryption...");
1727 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1728 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
1729 cipher->sesskey(session_key);
1733 if (pktin.type != SSH1_SMSG_SUCCESS) {
1734 bombout(("Encryption not successfully enabled"));
1738 logevent("Successfully started encryption");
1744 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1746 if (!ssh_get_line("login as: ",
1747 username, sizeof(username), FALSE)) {
1749 * get_line failed to get a username.
1752 logevent("No username provided. Abandoning session.");
1753 ssh_state = SSH_STATE_CLOSED;
1757 c_write_str("login as: ");
1760 crWaitUntil(!ispkt);
1762 switch (c = *in++) {
1771 c_write_str("\b \b");
1778 c_write_str("\b \b");
1788 if (((c >= ' ' && c <= '~') ||
1789 ((unsigned char) c >= 160))
1790 && pos < sizeof(username)-1) {
1791 username[pos++] = c;
1797 c_write_str("\r\n");
1798 username[strcspn(username, "\n\r")] = '\0';
1801 strncpy(username, cfg.username, 99);
1802 username[99] = '\0';
1805 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1807 char userlog[22 + sizeof(username)];
1808 sprintf(userlog, "Sent username \"%s\"", username);
1810 if (flags & FLAG_INTERACTIVE &&
1811 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1812 strcat(userlog, "\r\n");
1813 c_write_str(userlog);
1820 tried_publickey = 0;
1822 while (pktin.type == SSH1_SMSG_FAILURE) {
1823 static char password[100];
1824 static char prompt[200];
1827 static int pwpkt_type;
1829 * Show password prompt, having first obtained it via a TIS
1830 * or CryptoCard exchange if we're doing TIS or CryptoCard
1833 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1834 if (agent_exists()) {
1836 * Attempt RSA authentication using Pageant.
1838 static unsigned char request[5], *response, *p;
1839 static int responselen;
1840 static int i, nkeys;
1841 static int authed = FALSE;
1844 logevent("Pageant is running. Requesting keys.");
1846 /* Request the keys held by the agent. */
1847 PUT_32BIT(request, 1);
1848 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1849 agent_query(request, 5, &r, &responselen);
1850 response = (unsigned char *) r;
1851 if (response && responselen >= 5 &&
1852 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
1854 nkeys = GET_32BIT(p);
1858 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1861 for (i = 0; i < nkeys; i++) {
1862 static struct RSAKey key;
1863 static Bignum challenge;
1864 static char *commentp;
1865 static int commentlen;
1869 sprintf(buf, "Trying Pageant key #%d", i);
1873 p += ssh1_read_bignum(p, &key.exponent);
1874 p += ssh1_read_bignum(p, &key.modulus);
1875 commentlen = GET_32BIT(p);
1879 send_packet(SSH1_CMSG_AUTH_RSA,
1880 PKT_BIGNUM, key.modulus, PKT_END);
1882 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1883 logevent("Key refused");
1886 logevent("Received RSA challenge");
1887 ssh1_read_bignum(pktin.body, &challenge);
1889 char *agentreq, *q, *ret;
1892 len = 1 + 4; /* message type, bit count */
1893 len += ssh1_bignum_length(key.exponent);
1894 len += ssh1_bignum_length(key.modulus);
1895 len += ssh1_bignum_length(challenge);
1896 len += 16; /* session id */
1897 len += 4; /* response format */
1898 agentreq = smalloc(4 + len);
1899 PUT_32BIT(agentreq, len);
1901 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1902 PUT_32BIT(q, bignum_bitcount(key.modulus));
1904 q += ssh1_write_bignum(q, key.exponent);
1905 q += ssh1_write_bignum(q, key.modulus);
1906 q += ssh1_write_bignum(q, challenge);
1907 memcpy(q, session_id, 16);
1909 PUT_32BIT(q, 1); /* response format */
1910 agent_query(agentreq, len + 4, &vret, &retlen);
1914 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1915 logevent("Sending Pageant's response");
1916 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1917 PKT_DATA, ret + 5, 16,
1921 if (pktin.type == SSH1_SMSG_SUCCESS) {
1923 ("Pageant's response accepted");
1924 if (flags & FLAG_VERBOSE) {
1926 ("Authenticated using RSA key \"");
1927 c_write(commentp, commentlen);
1928 c_write_str("\" from agent\r\n");
1933 ("Pageant's response not accepted");
1936 ("Pageant failed to answer challenge");
1940 logevent("No reply received from Pageant");
1943 freebn(key.exponent);
1944 freebn(key.modulus);
1953 if (*cfg.keyfile && !tried_publickey)
1954 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1956 if (pktin.type == SSH1_SMSG_FAILURE &&
1958 (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
1959 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1960 logevent("Requested TIS authentication");
1961 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1963 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1964 logevent("TIS authentication declined");
1965 if (flags & FLAG_INTERACTIVE)
1966 c_write_str("TIS authentication refused.\r\n");
1968 int challengelen = ((pktin.body[0] << 24) |
1969 (pktin.body[1] << 16) |
1970 (pktin.body[2] << 8) |
1972 logevent("Received TIS challenge");
1973 if (challengelen > sizeof(prompt) - 1)
1974 challengelen = sizeof(prompt) - 1; /* prevent overrun */
1975 memcpy(prompt, pktin.body + 4, challengelen);
1976 prompt[challengelen] = '\0';
1979 if (pktin.type == SSH1_SMSG_FAILURE &&
1981 (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
1982 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1983 logevent("Requested CryptoCard authentication");
1984 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1986 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1987 logevent("CryptoCard authentication declined");
1988 c_write_str("CryptoCard authentication refused.\r\n");
1990 int challengelen = ((pktin.body[0] << 24) |
1991 (pktin.body[1] << 16) |
1992 (pktin.body[2] << 8) |
1994 logevent("Received CryptoCard challenge");
1995 if (challengelen > sizeof(prompt) - 1)
1996 challengelen = sizeof(prompt) - 1; /* prevent overrun */
1997 memcpy(prompt, pktin.body + 4, challengelen);
1998 strncpy(prompt + challengelen, "\r\nResponse : ",
1999 sizeof(prompt) - challengelen);
2000 prompt[sizeof(prompt) - 1] = '\0';
2003 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2004 sprintf(prompt, "%.90s@%.90s's password: ",
2005 username, savedhost);
2007 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2008 char *comment = NULL;
2009 if (flags & FLAG_VERBOSE)
2010 c_write_str("Trying public key authentication.\r\n");
2011 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2012 if (flags & FLAG_VERBOSE)
2013 c_write_str("No passphrase required.\r\n");
2016 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2021 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2023 * get_line failed to get a password (for example
2024 * because one was supplied on the command line
2025 * which has already failed to work). Terminate.
2027 send_packet(SSH1_MSG_DISCONNECT,
2028 PKT_STR, "No more passwords available to try",
2030 connection_fatal("Unable to authenticate");
2031 ssh_state = SSH_STATE_CLOSED;
2035 c_write_str(prompt);
2039 crWaitUntil(!ispkt);
2041 switch (c = *in++) {
2062 if (pos < sizeof(password)-1)
2063 password[pos++] = c;
2067 c_write_str("\r\n");
2071 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2073 * Try public key authentication with the specified
2076 static struct RSAKey pubkey;
2077 static Bignum challenge, response;
2079 static unsigned char buffer[32];
2081 tried_publickey = 1;
2082 i = loadrsakey(cfg.keyfile, &pubkey, password);
2084 c_write_str("Couldn't load public key from ");
2085 c_write_str(cfg.keyfile);
2086 c_write_str(".\r\n");
2087 continue; /* go and try password */
2090 c_write_str("Wrong passphrase.\r\n");
2091 tried_publickey = 0;
2092 continue; /* try again */
2096 * Send a public key attempt.
2098 send_packet(SSH1_CMSG_AUTH_RSA,
2099 PKT_BIGNUM, pubkey.modulus, PKT_END);
2102 if (pktin.type == SSH1_SMSG_FAILURE) {
2103 c_write_str("Server refused our public key.\r\n");
2104 continue; /* go and try password */
2106 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2107 bombout(("Bizarre response to offer of public key"));
2110 ssh1_read_bignum(pktin.body, &challenge);
2111 response = rsadecrypt(challenge, &pubkey);
2112 freebn(pubkey.private_exponent); /* burn the evidence */
2114 for (i = 0; i < 32; i++) {
2115 buffer[i] = bignum_byte(response, 31 - i);
2119 MD5Update(&md5c, buffer, 32);
2120 MD5Update(&md5c, session_id, 16);
2121 MD5Final(buffer, &md5c);
2123 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2124 PKT_DATA, buffer, 16, PKT_END);
2127 if (pktin.type == SSH1_SMSG_FAILURE) {
2128 if (flags & FLAG_VERBOSE)
2130 ("Failed to authenticate with our public key.\r\n");
2131 continue; /* go and try password */
2132 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2134 ("Bizarre response to RSA authentication response"));
2138 break; /* we're through! */
2140 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2142 * Defence against traffic analysis: we send a
2143 * whole bunch of packets containing strings of
2144 * different lengths. One of these strings is the
2145 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2146 * The others are all random data in
2147 * SSH1_MSG_IGNORE packets. This way a passive
2148 * listener can't tell which is the password, and
2149 * hence can't deduce the password length.
2151 * Anybody with a password length greater than 16
2152 * bytes is going to have enough entropy in their
2153 * password that a listener won't find it _that_
2154 * much help to know how long it is. So what we'll
2157 * - if password length < 16, we send 15 packets
2158 * containing string lengths 1 through 15
2160 * - otherwise, we let N be the nearest multiple
2161 * of 8 below the password length, and send 8
2162 * packets containing string lengths N through
2163 * N+7. This won't obscure the order of
2164 * magnitude of the password length, but it will
2165 * introduce a bit of extra uncertainty.
2167 * A few servers (the old 1.2.18 through 1.2.22)
2168 * can't deal with SSH1_MSG_IGNORE. For these
2169 * servers, we need an alternative defence. We make
2170 * use of the fact that the password is interpreted
2171 * as a C string: so we can append a NUL, then some
2174 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2179 len = strlen(password);
2180 if (len < sizeof(string)) {
2182 strcpy(string, password);
2183 len++; /* cover the zero byte */
2184 while (len < sizeof(string)) {
2185 string[len++] = (char) random_byte();
2190 send_packet(pwpkt_type, PKT_INT, len,
2191 PKT_DATA, s, len, PKT_END);
2193 int bottom, top, pwlen, i;
2196 pwlen = strlen(password);
2198 bottom = 0; /* zero length passwords are OK! :-) */
2201 bottom = pwlen & ~7;
2205 assert(pwlen >= bottom && pwlen <= top);
2207 randomstr = smalloc(top + 1);
2209 for (i = bottom; i <= top; i++) {
2211 defer_packet(pwpkt_type, PKT_STR, password,
2214 for (j = 0; j < i; j++) {
2216 randomstr[j] = random_byte();
2217 } while (randomstr[j] == '\0');
2219 randomstr[i] = '\0';
2220 defer_packet(SSH1_MSG_IGNORE,
2221 PKT_STR, randomstr, PKT_END);
2224 ssh_pkt_defersend();
2227 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2230 logevent("Sent password");
2231 memset(password, 0, strlen(password));
2233 if (pktin.type == SSH1_SMSG_FAILURE) {
2234 if (flags & FLAG_VERBOSE)
2235 c_write_str("Access denied\r\n");
2236 logevent("Authentication refused");
2237 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2238 logevent("Received disconnect request");
2239 ssh_state = SSH_STATE_CLOSED;
2241 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2242 bombout(("Strange packet received, type %d", pktin.type));
2247 logevent("Authentication successful");
2252 void sshfwd_close(struct ssh_channel *c)
2254 if (c && !c->closes) {
2255 if (ssh_version == 1) {
2256 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2259 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2260 ssh2_pkt_adduint32(c->remoteid);
2264 if (c->type == CHAN_X11) {
2266 logevent("X11 connection terminated");
2271 void sshfwd_write(struct ssh_channel *c, char *buf, int len)
2273 if (ssh_version == 1) {
2274 send_packet(SSH1_MSG_CHANNEL_DATA,
2275 PKT_INT, c->remoteid,
2276 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2278 ssh2_add_channel_data(c, buf, len);
2283 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2289 while (!do_ssh1_login(in, inlen, ispkt)) {
2292 if (ssh_state == SSH_STATE_CLOSED)
2295 if (cfg.agentfwd && agent_exists()) {
2296 logevent("Requesting agent forwarding");
2297 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2301 if (pktin.type != SSH1_SMSG_SUCCESS
2302 && pktin.type != SSH1_SMSG_FAILURE) {
2303 bombout(("Protocol confusion"));
2305 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2306 logevent("Agent forwarding refused");
2308 logevent("Agent forwarding enabled");
2309 ssh_agentfwd_enabled = TRUE;
2313 if (cfg.x11_forward) {
2314 char proto[20], data[64];
2315 logevent("Requesting X11 forwarding");
2316 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2317 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2318 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2319 PKT_STR, proto, PKT_STR, data,
2320 PKT_INT, 0, PKT_END);
2322 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2323 PKT_STR, proto, PKT_STR, data, PKT_END);
2328 if (pktin.type != SSH1_SMSG_SUCCESS
2329 && pktin.type != SSH1_SMSG_FAILURE) {
2330 bombout(("Protocol confusion"));
2332 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2333 logevent("X11 forwarding refused");
2335 logevent("X11 forwarding enabled");
2336 ssh_X11_fwd_enabled = TRUE;
2341 send_packet(SSH1_CMSG_REQUEST_PTY,
2342 PKT_STR, cfg.termtype,
2343 PKT_INT, rows, PKT_INT, cols,
2344 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2345 ssh_state = SSH_STATE_INTERMED;
2349 if (pktin.type != SSH1_SMSG_SUCCESS
2350 && pktin.type != SSH1_SMSG_FAILURE) {
2351 bombout(("Protocol confusion"));
2353 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2354 c_write_str("Server refused to allocate pty\r\n");
2355 ssh_editing = ssh_echoing = 1;
2357 logevent("Allocated pty");
2359 ssh_editing = ssh_echoing = 1;
2362 if (cfg.compression) {
2363 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2367 if (pktin.type != SSH1_SMSG_SUCCESS
2368 && pktin.type != SSH1_SMSG_FAILURE) {
2369 bombout(("Protocol confusion"));
2371 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2372 c_write_str("Server refused to compress\r\n");
2374 logevent("Started compression");
2375 ssh1_compressing = TRUE;
2376 zlib_compress_init();
2377 zlib_decompress_init();
2380 if (*cfg.remote_cmd_ptr)
2381 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr,
2384 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2385 logevent("Started session");
2387 ssh_state = SSH_STATE_SESSION;
2391 ssh_special(TS_EOF);
2393 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2395 ssh_channels = newtree234(ssh_channelcmp);
2399 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2400 pktin.type == SSH1_SMSG_STDERR_DATA) {
2401 long len = GET_32BIT(pktin.body);
2402 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2403 pktin.body + 4, len);
2404 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2405 ssh_state = SSH_STATE_CLOSED;
2406 logevent("Received disconnect request");
2408 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2409 /* Remote side is trying to open a channel to talk to our
2410 * X-Server. Give them back a local channel number. */
2411 struct ssh_channel *c;
2413 logevent("Received X11 connect request");
2414 /* Refuse if X11 forwarding is disabled. */
2415 if (!ssh_X11_fwd_enabled) {
2416 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2417 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2418 logevent("Rejected X11 connect request");
2420 c = smalloc(sizeof(struct ssh_channel));
2422 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2423 logevent("opening X11 forward connection failed");
2425 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2426 PKT_INT, GET_32BIT(pktin.body),
2430 ("opening X11 forward connection succeeded");
2431 c->remoteid = GET_32BIT(pktin.body);
2432 c->localid = alloc_channel_id();
2434 c->type = CHAN_X11; /* identify channel type */
2435 add234(ssh_channels, c);
2436 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2437 PKT_INT, c->remoteid, PKT_INT,
2438 c->localid, PKT_END);
2439 logevent("Opened X11 forward channel");
2442 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2443 /* Remote side is trying to open a channel to talk to our
2444 * agent. Give them back a local channel number. */
2445 struct ssh_channel *c;
2447 /* Refuse if agent forwarding is disabled. */
2448 if (!ssh_agentfwd_enabled) {
2449 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2450 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2452 c = smalloc(sizeof(struct ssh_channel));
2453 c->remoteid = GET_32BIT(pktin.body);
2454 c->localid = alloc_channel_id();
2456 c->type = CHAN_AGENT; /* identify channel type */
2457 c->u.a.lensofar = 0;
2458 add234(ssh_channels, c);
2459 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2460 PKT_INT, c->remoteid, PKT_INT, c->localid,
2463 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2464 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2465 /* Remote side closes a channel. */
2466 unsigned i = GET_32BIT(pktin.body);
2467 struct ssh_channel *c;
2468 c = find234(ssh_channels, &i, ssh_channelfind);
2472 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2473 if (!(c->closes & closetype))
2474 send_packet(pktin.type, PKT_INT, c->remoteid,
2476 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2477 logevent("X11 connection closed");
2478 assert(c->u.x11.s != NULL);
2479 x11_close(c->u.x11.s);
2482 c->closes |= closetype;
2483 if (c->closes == 3) {
2484 del234(ssh_channels, c);
2488 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2489 /* Data sent down one of our channels. */
2490 int i = GET_32BIT(pktin.body);
2491 int len = GET_32BIT(pktin.body + 4);
2492 unsigned char *p = pktin.body + 8;
2493 struct ssh_channel *c;
2494 c = find234(ssh_channels, &i, ssh_channelfind);
2498 x11_send(c->u.x11.s, p, len);
2501 /* Data for an agent message. Buffer it. */
2503 if (c->u.a.lensofar < 4) {
2504 int l = min(4 - c->u.a.lensofar, len);
2505 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2509 c->u.a.lensofar += l;
2511 if (c->u.a.lensofar == 4) {
2513 4 + GET_32BIT(c->u.a.msglen);
2514 c->u.a.message = smalloc(c->u.a.totallen);
2515 memcpy(c->u.a.message, c->u.a.msglen, 4);
2517 if (c->u.a.lensofar >= 4 && len > 0) {
2519 min(c->u.a.totallen - c->u.a.lensofar,
2521 memcpy(c->u.a.message + c->u.a.lensofar, p,
2525 c->u.a.lensofar += l;
2527 if (c->u.a.lensofar == c->u.a.totallen) {
2528 void *reply, *sentreply;
2530 agent_query(c->u.a.message,
2531 c->u.a.totallen, &reply,
2536 /* Fake SSH_AGENT_FAILURE. */
2537 sentreply = "\0\0\0\1\5";
2540 send_packet(SSH1_MSG_CHANNEL_DATA,
2541 PKT_INT, c->remoteid,
2543 PKT_DATA, sentreply, replylen,
2547 sfree(c->u.a.message);
2548 c->u.a.lensofar = 0;
2554 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2555 /* may be from EXEC_SHELL on some servers */
2556 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2557 /* may be from EXEC_SHELL on some servers
2558 * if no pty is available or in other odd cases. Ignore */
2559 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2560 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2562 bombout(("Strange packet received: type %d", pktin.type));
2567 int len = min(inlen, 512);
2568 send_packet(SSH1_CMSG_STDIN_DATA,
2569 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2580 * Utility routine for decoding comma-separated strings in KEXINIT.
2582 static int in_commasep_string(char *needle, char *haystack, int haylen)
2584 int needlen = strlen(needle);
2587 * Is it at the start of the string?
2589 if (haylen >= needlen && /* haystack is long enough */
2590 !memcmp(needle, haystack, needlen) && /* initial match */
2591 (haylen == needlen || haystack[needlen] == ',')
2592 /* either , or EOS follows */
2596 * If not, search for the next comma and resume after that.
2597 * If no comma found, terminate.
2599 while (haylen > 0 && *haystack != ',')
2600 haylen--, haystack++;
2603 haylen--, haystack++; /* skip over comma itself */
2608 * SSH2 key creation method.
2610 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
2614 /* First 20 bytes. */
2617 SHA_Bytes(&s, H, 20);
2618 SHA_Bytes(&s, &chr, 1);
2619 SHA_Bytes(&s, sessid, 20);
2620 SHA_Final(&s, keyspace);
2621 /* Next 20 bytes. */
2624 SHA_Bytes(&s, H, 20);
2625 SHA_Bytes(&s, keyspace, 20);
2626 SHA_Final(&s, keyspace + 20);
2630 * Handle the SSH2 transport layer.
2632 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2634 static int i, j, len, nbits, pbits;
2636 static Bignum p, g, e, f, K;
2637 static int kex_init_value, kex_reply_value;
2638 static const struct ssh_mac **maclist;
2640 static const struct ssh2_cipher *cscipher_tobe = NULL;
2641 static const struct ssh2_cipher *sccipher_tobe = NULL;
2642 static const struct ssh_mac *csmac_tobe = NULL;
2643 static const struct ssh_mac *scmac_tobe = NULL;
2644 static const struct ssh_compress *cscomp_tobe = NULL;
2645 static const struct ssh_compress *sccomp_tobe = NULL;
2646 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2647 static int hostkeylen, siglen;
2648 static void *hkey; /* actual host key */
2649 static unsigned char exchange_hash[20];
2650 static unsigned char keyspace[40];
2651 static const struct ssh2_ciphers *preferred_cipher;
2652 static const struct ssh_compress *preferred_comp;
2653 static int first_kex;
2660 * Set up the preferred cipher and compression.
2662 if (cfg.cipher == CIPHER_BLOWFISH) {
2663 preferred_cipher = &ssh2_blowfish;
2664 } else if (cfg.cipher == CIPHER_DES) {
2665 logevent("Single DES not supported in SSH2; using 3DES");
2666 preferred_cipher = &ssh2_3des;
2667 } else if (cfg.cipher == CIPHER_3DES) {
2668 preferred_cipher = &ssh2_3des;
2669 } else if (cfg.cipher == CIPHER_AES) {
2670 preferred_cipher = &ssh2_aes;
2672 /* Shouldn't happen, but we do want to initialise to _something_. */
2673 preferred_cipher = &ssh2_3des;
2675 if (cfg.compression)
2676 preferred_comp = &ssh_zlib;
2678 preferred_comp = &ssh_comp_none;
2681 * Be prepared to work around the buggy MAC problem.
2683 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
2684 maclist = buggymacs, nmacs = lenof(buggymacs);
2686 maclist = macs, nmacs = lenof(macs);
2690 * Construct and send our key exchange packet.
2692 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2693 for (i = 0; i < 16; i++)
2694 ssh2_pkt_addbyte((unsigned char) random_byte());
2695 /* List key exchange algorithms. */
2696 ssh2_pkt_addstring_start();
2697 for (i = 0; i < lenof(kex_algs); i++) {
2698 ssh2_pkt_addstring_str(kex_algs[i]->name);
2699 if (i < lenof(kex_algs) - 1)
2700 ssh2_pkt_addstring_str(",");
2702 /* List server host key algorithms. */
2703 ssh2_pkt_addstring_start();
2704 for (i = 0; i < lenof(hostkey_algs); i++) {
2705 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2706 if (i < lenof(hostkey_algs) - 1)
2707 ssh2_pkt_addstring_str(",");
2709 /* List client->server encryption algorithms. */
2710 ssh2_pkt_addstring_start();
2711 for (i = 0; i < lenof(ciphers) + 1; i++) {
2712 const struct ssh2_ciphers *c =
2713 i == 0 ? preferred_cipher : ciphers[i - 1];
2714 for (j = 0; j < c->nciphers; j++) {
2715 ssh2_pkt_addstring_str(c->list[j]->name);
2716 if (i < lenof(ciphers) || j < c->nciphers - 1)
2717 ssh2_pkt_addstring_str(",");
2720 /* List server->client encryption algorithms. */
2721 ssh2_pkt_addstring_start();
2722 for (i = 0; i < lenof(ciphers) + 1; i++) {
2723 const struct ssh2_ciphers *c =
2724 i == 0 ? preferred_cipher : ciphers[i - 1];
2725 for (j = 0; j < c->nciphers; j++) {
2726 ssh2_pkt_addstring_str(c->list[j]->name);
2727 if (i < lenof(ciphers) || j < c->nciphers - 1)
2728 ssh2_pkt_addstring_str(",");
2731 /* List client->server MAC algorithms. */
2732 ssh2_pkt_addstring_start();
2733 for (i = 0; i < nmacs; i++) {
2734 ssh2_pkt_addstring_str(maclist[i]->name);
2736 ssh2_pkt_addstring_str(",");
2738 /* List server->client MAC algorithms. */
2739 ssh2_pkt_addstring_start();
2740 for (i = 0; i < nmacs; i++) {
2741 ssh2_pkt_addstring_str(maclist[i]->name);
2743 ssh2_pkt_addstring_str(",");
2745 /* List client->server compression algorithms. */
2746 ssh2_pkt_addstring_start();
2747 for (i = 0; i < lenof(compressions) + 1; i++) {
2748 const struct ssh_compress *c =
2749 i == 0 ? preferred_comp : compressions[i - 1];
2750 ssh2_pkt_addstring_str(c->name);
2751 if (i < lenof(compressions))
2752 ssh2_pkt_addstring_str(",");
2754 /* List server->client compression algorithms. */
2755 ssh2_pkt_addstring_start();
2756 for (i = 0; i < lenof(compressions) + 1; i++) {
2757 const struct ssh_compress *c =
2758 i == 0 ? preferred_comp : compressions[i - 1];
2759 ssh2_pkt_addstring_str(c->name);
2760 if (i < lenof(compressions))
2761 ssh2_pkt_addstring_str(",");
2763 /* List client->server languages. Empty list. */
2764 ssh2_pkt_addstring_start();
2765 /* List server->client languages. Empty list. */
2766 ssh2_pkt_addstring_start();
2767 /* First KEX packet does _not_ follow, because we're not that brave. */
2768 ssh2_pkt_addbool(FALSE);
2770 ssh2_pkt_adduint32(0);
2772 exhash = exhashbase;
2773 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
2779 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
2782 * Now examine the other side's KEXINIT to see what we're up
2785 if (pktin.type != SSH2_MSG_KEXINIT) {
2786 bombout(("expected key exchange packet from server"));
2791 cscipher_tobe = NULL;
2792 sccipher_tobe = NULL;
2797 pktin.savedpos += 16; /* skip garbage cookie */
2798 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2799 for (i = 0; i < lenof(kex_algs); i++) {
2800 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2805 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2806 for (i = 0; i < lenof(hostkey_algs); i++) {
2807 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2808 hostkey = hostkey_algs[i];
2812 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2813 for (i = 0; i < lenof(ciphers) + 1; i++) {
2814 const struct ssh2_ciphers *c =
2815 i == 0 ? preferred_cipher : ciphers[i - 1];
2816 for (j = 0; j < c->nciphers; j++) {
2817 if (in_commasep_string(c->list[j]->name, str, len)) {
2818 cscipher_tobe = c->list[j];
2825 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2826 for (i = 0; i < lenof(ciphers) + 1; i++) {
2827 const struct ssh2_ciphers *c =
2828 i == 0 ? preferred_cipher : ciphers[i - 1];
2829 for (j = 0; j < c->nciphers; j++) {
2830 if (in_commasep_string(c->list[j]->name, str, len)) {
2831 sccipher_tobe = c->list[j];
2838 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2839 for (i = 0; i < nmacs; i++) {
2840 if (in_commasep_string(maclist[i]->name, str, len)) {
2841 csmac_tobe = maclist[i];
2845 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2846 for (i = 0; i < nmacs; i++) {
2847 if (in_commasep_string(maclist[i]->name, str, len)) {
2848 scmac_tobe = maclist[i];
2852 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2853 for (i = 0; i < lenof(compressions) + 1; i++) {
2854 const struct ssh_compress *c =
2855 i == 0 ? preferred_comp : compressions[i - 1];
2856 if (in_commasep_string(c->name, str, len)) {
2861 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2862 for (i = 0; i < lenof(compressions) + 1; i++) {
2863 const struct ssh_compress *c =
2864 i == 0 ? preferred_comp : compressions[i - 1];
2865 if (in_commasep_string(c->name, str, len)) {
2872 * Work out the number of bits of key we will need from the key
2873 * exchange. We start with the maximum key length of either
2879 csbits = cscipher_tobe->keylen;
2880 scbits = sccipher_tobe->keylen;
2881 nbits = (csbits > scbits ? csbits : scbits);
2883 /* The keys only have 160-bit entropy, since they're based on
2884 * a SHA-1 hash. So cap the key size at 160 bits. */
2889 * If we're doing Diffie-Hellman group exchange, start by
2890 * requesting a group.
2892 if (kex == &ssh_diffiehellman_gex) {
2893 logevent("Doing Diffie-Hellman group exchange");
2895 * Work out how big a DH group we will need to allow that
2898 pbits = 512 << ((nbits - 1) / 64);
2899 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2900 ssh2_pkt_adduint32(pbits);
2904 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2905 bombout(("expected key exchange group packet from server"));
2908 p = ssh2_pkt_getmp();
2909 g = ssh2_pkt_getmp();
2910 dh_setup_group(p, g);
2911 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2912 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2915 kex_init_value = SSH2_MSG_KEXDH_INIT;
2916 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
2919 logevent("Doing Diffie-Hellman key exchange");
2921 * Now generate and send e for Diffie-Hellman.
2923 e = dh_create_e(nbits * 2);
2924 ssh2_pkt_init(kex_init_value);
2929 if (pktin.type != kex_reply_value) {
2930 bombout(("expected key exchange reply packet from server"));
2933 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2934 f = ssh2_pkt_getmp();
2935 ssh2_pkt_getstring(&sigdata, &siglen);
2939 sha_string(&exhash, hostkeydata, hostkeylen);
2940 if (kex == &ssh_diffiehellman_gex) {
2941 sha_uint32(&exhash, pbits);
2942 sha_mpint(&exhash, p);
2943 sha_mpint(&exhash, g);
2945 sha_mpint(&exhash, e);
2946 sha_mpint(&exhash, f);
2947 sha_mpint(&exhash, K);
2948 SHA_Final(&exhash, exchange_hash);
2953 debug(("Exchange hash is:\n"));
2954 dmemdump(exchange_hash, 20);
2957 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2959 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2960 bombout(("Server's host key did not match the signature supplied"));
2965 * Expect SSH2_MSG_NEWKEYS from server.
2968 if (pktin.type != SSH2_MSG_NEWKEYS) {
2969 bombout(("expected new-keys packet from server"));
2974 * Authenticate remote host: verify host key. (We've already
2975 * checked the signature of the exchange hash.)
2977 keystr = hostkey->fmtkey(hkey);
2978 fingerprint = hostkey->fingerprint(hkey);
2979 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2980 keystr, fingerprint);
2981 if (first_kex) { /* don't bother logging this in rekeys */
2982 logevent("Host key fingerprint is:");
2983 logevent(fingerprint);
2987 hostkey->freekey(hkey);
2990 * Send SSH2_MSG_NEWKEYS.
2992 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2996 * Create and initialise session keys.
2998 cscipher = cscipher_tobe;
2999 sccipher = sccipher_tobe;
3002 cscomp = cscomp_tobe;
3003 sccomp = sccomp_tobe;
3004 cscomp->compress_init();
3005 sccomp->decompress_init();
3007 * Set IVs after keys. Here we use the exchange hash from the
3008 * _first_ key exchange.
3011 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3012 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3013 cscipher->setcskey(keyspace);
3014 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3015 sccipher->setsckey(keyspace);
3016 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3017 cscipher->setcsiv(keyspace);
3018 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3019 sccipher->setsciv(keyspace);
3020 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3021 csmac->setcskey(keyspace);
3022 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3023 scmac->setsckey(keyspace);
3026 * If this is the first key exchange phase, we must pass the
3027 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3028 * wants to see it but because it will need time to initialise
3029 * itself before it sees an actual packet. In subsequent key
3030 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3031 * it would only confuse the layer above.
3039 * Now we're encrypting. Begin returning 1 to the protocol main
3040 * function so that other things can run on top of the
3041 * transport. If we ever see a KEXINIT, we must go back to the
3044 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3047 logevent("Server initiated key re-exchange");
3048 goto begin_key_exchange;
3054 * Add data to an SSH2 channel output buffer.
3056 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3059 if (c->v2.outbufsize < c->v2.outbuflen + len) {
3060 c->v2.outbufsize = c->v2.outbuflen + len + 1024;
3061 c->v2.outbuffer = srealloc(c->v2.outbuffer, c->v2.outbufsize);
3063 memcpy(c->v2.outbuffer + c->v2.outbuflen, buf, len);
3064 c->v2.outbuflen += len;
3068 * Attempt to send data on an SSH2 channel.
3070 static void ssh2_try_send(struct ssh_channel *c)
3072 while (c->v2.remwindow > 0 && c->v2.outbuflen > 0) {
3073 unsigned len = c->v2.remwindow;
3074 if (len > c->v2.outbuflen)
3075 len = c->v2.outbuflen;
3076 if (len > c->v2.remmaxpkt)
3077 len = c->v2.remmaxpkt;
3078 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3079 ssh2_pkt_adduint32(c->remoteid);
3080 ssh2_pkt_addstring_start();
3081 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
3083 c->v2.outbuflen -= len;
3084 memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
3085 c->v2.remwindow -= len;
3090 * Handle the SSH2 userauth and connection layers.
3092 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3095 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3100 AUTH_TYPE_PUBLICKEY,
3101 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3102 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3105 static int gotit, need_pw, can_pubkey, can_passwd;
3106 static int tried_pubkey_config, tried_agent;
3107 static int we_are_in;
3108 static char username[100];
3109 static char pwprompt[200];
3110 static char password[100];
3115 * Request userauth protocol, and await a response to it.
3117 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3118 ssh2_pkt_addstring("ssh-userauth");
3120 crWaitUntilV(ispkt);
3121 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3122 bombout(("Server refused user authentication protocol"));
3127 * We repeat this whole loop, including the username prompt,
3128 * until we manage a successful authentication. If the user
3129 * types the wrong _password_, they are sent back to the
3130 * beginning to try another username. (If they specify a
3131 * username in the config, they are never asked, even if they
3132 * do give a wrong password.)
3134 * I think this best serves the needs of
3136 * - the people who have no configuration, no keys, and just
3137 * want to try repeated (username,password) pairs until they
3138 * type both correctly
3140 * - people who have keys and configuration but occasionally
3141 * need to fall back to passwords
3143 * - people with a key held in Pageant, who might not have
3144 * logged in to a particular machine before; so they want to
3145 * type a username, and then _either_ their key will be
3146 * accepted, _or_ they will type a password. If they mistype
3147 * the username they will want to be able to get back and
3158 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3160 if (!ssh_get_line("login as: ",
3161 username, sizeof(username), FALSE)) {
3163 * get_line failed to get a username.
3166 logevent("No username provided. Abandoning session.");
3167 ssh_state = SSH_STATE_CLOSED;
3171 c_write_str("login as: ");
3174 crWaitUntilV(!ispkt);
3176 switch (c = *in++) {
3185 c_write_str("\b \b");
3192 c_write_str("\b \b");
3202 if (((c >= ' ' && c <= '~') ||
3203 ((unsigned char) c >= 160))
3204 && pos < sizeof(username)-1) {
3205 username[pos++] = c;
3212 c_write_str("\r\n");
3213 username[strcspn(username, "\n\r")] = '\0';
3216 strncpy(username, cfg.username, 99);
3217 username[99] = '\0';
3218 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3219 sprintf(stuff, "Using username \"%s\".\r\n", username);
3225 * Send an authentication request using method "none": (a)
3226 * just in case it succeeds, and (b) so that we know what
3227 * authentication methods we can usefully try next.
3229 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3230 ssh2_pkt_addstring(username);
3231 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3232 ssh2_pkt_addstring("none"); /* method */
3234 type = AUTH_TYPE_NONE;
3238 tried_pubkey_config = FALSE;
3239 tried_agent = FALSE;
3243 * Wait for the result of the last authentication request.
3246 crWaitUntilV(ispkt);
3247 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3251 * Don't show the banner if we're operating in
3252 * non-verbose non-interactive mode. (It's probably
3253 * a script, which means nobody will read the
3254 * banner _anyway_, and moreover the printing of
3255 * the banner will screw up processing on the
3256 * output of (say) plink.)
3258 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3259 ssh2_pkt_getstring(&banner, &size);
3261 c_write_untrusted(banner, size);
3263 crWaitUntilV(ispkt);
3265 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3266 logevent("Access granted");
3271 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3273 ("Strange packet received during authentication: type %d",
3281 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3282 * we can look at the string in it and know what we can
3283 * helpfully try next.
3288 ssh2_pkt_getstring(&methods, &methlen);
3289 if (!ssh2_pkt_getbool()) {
3291 * We have received an unequivocal Access
3292 * Denied. This can translate to a variety of
3295 * - if we'd just tried "none" authentication,
3296 * it's not worth printing anything at all
3298 * - if we'd just tried a public key _offer_,
3299 * the message should be "Server refused our
3300 * key" (or no message at all if the key
3301 * came from Pageant)
3303 * - if we'd just tried anything else, the
3304 * message really should be "Access denied".
3306 * Additionally, if we'd just tried password
3307 * authentication, we should break out of this
3308 * whole loop so as to go back to the username
3311 if (type == AUTH_TYPE_NONE) {
3313 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3314 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3315 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3316 c_write_str("Server refused our key\r\n");
3317 logevent("Server refused public key");
3319 c_write_str("Access denied\r\n");
3320 logevent("Access denied");
3321 if (type == AUTH_TYPE_PASSWORD) {
3327 c_write_str("Further authentication required\r\n");
3328 logevent("Further authentication required");
3332 in_commasep_string("publickey", methods, methlen);
3334 in_commasep_string("password", methods, methlen);
3339 if (!method && can_pubkey && agent_exists() && !tried_agent) {
3341 * Attempt public-key authentication using Pageant.
3343 static unsigned char request[5], *response, *p;
3344 static int responselen;
3345 static int i, nkeys;
3346 static int authed = FALSE;
3351 logevent("Pageant is running. Requesting keys.");
3353 /* Request the keys held by the agent. */
3354 PUT_32BIT(request, 1);
3355 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3356 agent_query(request, 5, &r, &responselen);
3357 response = (unsigned char *) r;
3358 if (response && responselen >= 5 &&
3359 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3361 nkeys = GET_32BIT(p);
3365 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3368 for (i = 0; i < nkeys; i++) {
3369 static char *pkblob, *alg, *commentp;
3370 static int pklen, alglen, commentlen;
3371 static int siglen, retlen, len;
3372 static char *q, *agentreq, *ret;
3377 sprintf(buf, "Trying Pageant key #%d", i);
3380 pklen = GET_32BIT(p);
3384 alglen = GET_32BIT(pkblob);
3386 commentlen = GET_32BIT(p);
3390 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3391 ssh2_pkt_addstring(username);
3392 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3393 ssh2_pkt_addstring("publickey"); /* method */
3394 ssh2_pkt_addbool(FALSE); /* no signature included */
3395 ssh2_pkt_addstring_start();
3396 ssh2_pkt_addstring_data(alg, alglen);
3397 ssh2_pkt_addstring_start();
3398 ssh2_pkt_addstring_data(pkblob, pklen);
3401 crWaitUntilV(ispkt);
3402 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3403 logevent("Key refused");
3407 if (flags & FLAG_VERBOSE) {
3409 ("Authenticating with public key \"");
3410 c_write(commentp, commentlen);
3411 c_write_str("\" from agent\r\n");
3415 * Server is willing to accept the key.
3416 * Construct a SIGN_REQUEST.
3418 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3419 ssh2_pkt_addstring(username);
3420 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3421 ssh2_pkt_addstring("publickey"); /* method */
3422 ssh2_pkt_addbool(TRUE);
3423 ssh2_pkt_addstring_start();
3424 ssh2_pkt_addstring_data(alg, alglen);
3425 ssh2_pkt_addstring_start();
3426 ssh2_pkt_addstring_data(pkblob, pklen);
3428 siglen = pktout.length - 5 + 4 + 20;
3429 len = 1; /* message type */
3430 len += 4 + pklen; /* key blob */
3431 len += 4 + siglen; /* data to sign */
3432 len += 4; /* flags */
3433 agentreq = smalloc(4 + len);
3434 PUT_32BIT(agentreq, len);
3436 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3437 PUT_32BIT(q, pklen);
3439 memcpy(q, pkblob, pklen);
3441 PUT_32BIT(q, siglen);
3443 /* Now the data to be signed... */
3446 memcpy(q, ssh2_session_id, 20);
3448 memcpy(q, pktout.data + 5, pktout.length - 5);
3449 q += pktout.length - 5;
3450 /* And finally the (zero) flags word. */
3452 agent_query(agentreq, len + 4, &vret, &retlen);
3456 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3457 logevent("Sending Pageant's response");
3458 ssh2_pkt_addstring_start();
3459 ssh2_pkt_addstring_data(ret + 9,
3467 ("Pageant failed to answer challenge");
3477 if (!method && can_pubkey && *cfg.keyfile
3478 && !tried_pubkey_config) {
3479 unsigned char *pub_blob;
3480 char *algorithm, *comment;
3483 tried_pubkey_config = TRUE;
3486 * Try the public key supplied in the configuration.
3488 * First, offer the public blob to see if the server is
3489 * willing to accept it.
3491 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3494 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3495 ssh2_pkt_addstring(username);
3496 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3497 ssh2_pkt_addstring("publickey"); /* method */
3498 ssh2_pkt_addbool(FALSE); /* no signature included */
3499 ssh2_pkt_addstring(algorithm);
3500 ssh2_pkt_addstring_start();
3501 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3503 logevent("Offered public key"); /* FIXME */
3505 crWaitUntilV(ispkt);
3506 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3508 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3509 continue; /* key refused; give up on it */
3512 logevent("Offer of public key accepted");
3514 * Actually attempt a serious authentication using
3517 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3519 "Passphrase for key \"%.100s\": ",
3525 c_write_str("Authenticating with public key \"");
3526 c_write_str(comment);
3527 c_write_str("\"\r\n");
3528 method = AUTH_PUBLICKEY_FILE;
3532 if (!method && can_passwd) {
3533 method = AUTH_PASSWORD;
3534 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
3541 if (!ssh_get_line(pwprompt, password,
3542 sizeof(password), TRUE)) {
3544 * get_line failed to get a password (for
3545 * example because one was supplied on the
3546 * command line which has already failed to
3549 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3550 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3552 ("No more passwords available to try");
3553 ssh2_pkt_addstring("en"); /* language tag */
3555 connection_fatal("Unable to authenticate");
3556 ssh_state = SSH_STATE_CLOSED;
3563 c_write_str(pwprompt);
3568 crWaitUntilV(!ispkt);
3570 switch (c = *in++) {
3591 if (pos < sizeof(password)-1)
3592 password[pos++] = c;
3596 c_write_str("\r\n");
3600 if (method == AUTH_PUBLICKEY_FILE) {
3602 * We have our passphrase. Now try the actual authentication.
3604 struct ssh2_userkey *key;
3606 key = ssh2_load_userkey(cfg.keyfile, password);
3607 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3608 if (key == SSH2_WRONG_PASSPHRASE) {
3609 c_write_str("Wrong passphrase\r\n");
3610 tried_pubkey_config = FALSE;
3612 c_write_str("Unable to load private key\r\n");
3613 tried_pubkey_config = TRUE;
3615 /* Send a spurious AUTH_NONE to return to the top. */
3616 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3617 ssh2_pkt_addstring(username);
3618 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3619 ssh2_pkt_addstring("none"); /* method */
3621 type = AUTH_TYPE_NONE;
3623 unsigned char *blob, *sigdata;
3624 int blob_len, sigdata_len;
3627 * We have loaded the private key and the server
3628 * has announced that it's willing to accept it.
3629 * Hallelujah. Generate a signature and send it.
3631 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3632 ssh2_pkt_addstring(username);
3633 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3634 ssh2_pkt_addstring("publickey"); /* method */
3635 ssh2_pkt_addbool(TRUE);
3636 ssh2_pkt_addstring(key->alg->name);
3637 blob = key->alg->public_blob(key->data, &blob_len);
3638 ssh2_pkt_addstring_start();
3639 ssh2_pkt_addstring_data(blob, blob_len);
3643 * The data to be signed is:
3647 * followed by everything so far placed in the
3650 sigdata_len = pktout.length - 5 + 4 + 20;
3651 sigdata = smalloc(sigdata_len);
3652 PUT_32BIT(sigdata, 20);
3653 memcpy(sigdata + 4, ssh2_session_id, 20);
3654 memcpy(sigdata + 24, pktout.data + 5,
3657 key->alg->sign(key->data, sigdata, sigdata_len,
3659 ssh2_pkt_addstring_start();
3660 ssh2_pkt_addstring_data(blob, blob_len);
3665 type = AUTH_TYPE_PUBLICKEY;
3667 } else if (method == AUTH_PASSWORD) {
3669 * We send the password packet lumped tightly together with
3670 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3671 * string long enough to make the total length of the two
3672 * packets constant. This should ensure that a passive
3673 * listener doing traffic analyis can't work out the length
3676 * For this to work, we need an assumption about the
3677 * maximum length of the password packet. I think 256 is
3678 * pretty conservative. Anyone using a password longer than
3679 * that probably doesn't have much to worry about from
3680 * people who find out how long their password is!
3682 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3683 ssh2_pkt_addstring(username);
3684 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3685 ssh2_pkt_addstring("password");
3686 ssh2_pkt_addbool(FALSE);
3687 ssh2_pkt_addstring(password);
3690 * We'll include a string that's an exact multiple of the
3691 * cipher block size. If the cipher is NULL for some
3692 * reason, we don't do this trick at all because we gain
3698 stringlen = (256 - deferred_len);
3699 stringlen += cscipher->blksize - 1;
3700 stringlen -= (stringlen % cscipher->blksize);
3703 * Temporarily disable actual compression,
3704 * so we can guarantee to get this string
3705 * exactly the length we want it. The
3706 * compression-disabling routine should
3707 * return an integer indicating how many
3708 * bytes we should adjust our string length
3711 stringlen -= cscomp->disable_compression();
3713 ssh2_pkt_init(SSH2_MSG_IGNORE);
3714 ssh2_pkt_addstring_start();
3715 for (i = 0; i < stringlen; i++) {
3716 char c = (char) random_byte();
3717 ssh2_pkt_addstring_data(&c, 1);
3721 ssh_pkt_defersend();
3722 logevent("Sent password");
3723 type = AUTH_TYPE_PASSWORD;
3726 ("No supported authentication methods left to try!\r\n");
3728 ("No supported authentications offered. Disconnecting");
3729 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3730 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3732 ("No supported authentication methods available");
3733 ssh2_pkt_addstring("en"); /* language tag */
3735 ssh_state = SSH_STATE_CLOSED;
3739 } while (!we_are_in);
3742 * Now we're authenticated for the connection protocol. The
3743 * connection protocol will automatically have started at this
3744 * point; there's no need to send SERVICE_REQUEST.
3748 * So now create a channel with a session in it.
3750 ssh_channels = newtree234(ssh_channelcmp);
3751 mainchan = smalloc(sizeof(struct ssh_channel));
3752 mainchan->localid = alloc_channel_id();
3753 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3754 ssh2_pkt_addstring("session");
3755 ssh2_pkt_adduint32(mainchan->localid);
3756 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3757 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3759 crWaitUntilV(ispkt);
3760 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
3761 bombout(("Server refused to open a session"));
3763 /* FIXME: error data comes back in FAILURE packet */
3765 if (ssh2_pkt_getuint32() != mainchan->localid) {
3766 bombout(("Server's channel confirmation cited wrong channel"));
3769 mainchan->remoteid = ssh2_pkt_getuint32();
3770 mainchan->type = CHAN_MAINSESSION;
3771 mainchan->closes = 0;
3772 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3773 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3774 mainchan->v2.outbuffer = NULL;
3775 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3776 add234(ssh_channels, mainchan);
3777 logevent("Opened channel for session");
3780 * Potentially enable X11 forwarding.
3782 if (cfg.x11_forward) {
3783 char proto[20], data[64];
3784 logevent("Requesting X11 forwarding");
3785 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3786 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3787 ssh2_pkt_adduint32(mainchan->remoteid);
3788 ssh2_pkt_addstring("x11-req");
3789 ssh2_pkt_addbool(1); /* want reply */
3790 ssh2_pkt_addbool(0); /* many connections */
3791 ssh2_pkt_addstring(proto);
3792 ssh2_pkt_addstring(data);
3793 ssh2_pkt_adduint32(0); /* screen number */
3797 crWaitUntilV(ispkt);
3798 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3799 unsigned i = ssh2_pkt_getuint32();
3800 struct ssh_channel *c;
3801 c = find234(ssh_channels, &i, ssh_channelfind);
3803 continue; /* nonexistent channel */
3804 c->v2.remwindow += ssh2_pkt_getuint32();
3806 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3808 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3809 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3810 bombout(("Server got confused by X11 forwarding request"));
3813 logevent("X11 forwarding refused");
3815 logevent("X11 forwarding enabled");
3816 ssh_X11_fwd_enabled = TRUE;
3821 * Potentially enable agent forwarding.
3823 if (cfg.agentfwd && agent_exists()) {
3824 logevent("Requesting OpenSSH-style agent forwarding");
3825 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3826 ssh2_pkt_adduint32(mainchan->remoteid);
3827 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3828 ssh2_pkt_addbool(1); /* want reply */
3832 crWaitUntilV(ispkt);
3833 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3834 unsigned i = ssh2_pkt_getuint32();
3835 struct ssh_channel *c;
3836 c = find234(ssh_channels, &i, ssh_channelfind);
3838 continue; /* nonexistent channel */
3839 c->v2.remwindow += ssh2_pkt_getuint32();
3841 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3843 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3844 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3846 ("Server got confused by agent forwarding request"));
3849 logevent("Agent forwarding refused");
3851 logevent("Agent forwarding enabled");
3852 ssh_agentfwd_enabled = TRUE;
3857 * Now allocate a pty for the session.
3860 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3861 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3862 ssh2_pkt_addstring("pty-req");
3863 ssh2_pkt_addbool(1); /* want reply */
3864 ssh2_pkt_addstring(cfg.termtype);
3865 ssh2_pkt_adduint32(cols);
3866 ssh2_pkt_adduint32(rows);
3867 ssh2_pkt_adduint32(0); /* pixel width */
3868 ssh2_pkt_adduint32(0); /* pixel height */
3869 ssh2_pkt_addstring_start();
3870 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
3872 ssh_state = SSH_STATE_INTERMED;
3875 crWaitUntilV(ispkt);
3876 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3877 unsigned i = ssh2_pkt_getuint32();
3878 struct ssh_channel *c;
3879 c = find234(ssh_channels, &i, ssh_channelfind);
3881 continue; /* nonexistent channel */
3882 c->v2.remwindow += ssh2_pkt_getuint32();
3884 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3886 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3887 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3888 bombout(("Server got confused by pty request"));
3891 c_write_str("Server refused to allocate pty\r\n");
3892 ssh_editing = ssh_echoing = 1;
3894 logevent("Allocated pty");
3897 ssh_editing = ssh_echoing = 1;
3901 * Start a shell or a remote command.
3903 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3904 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3905 if (cfg.ssh_subsys) {
3906 ssh2_pkt_addstring("subsystem");
3907 ssh2_pkt_addbool(1); /* want reply */
3908 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
3909 } else if (*cfg.remote_cmd_ptr) {
3910 ssh2_pkt_addstring("exec");
3911 ssh2_pkt_addbool(1); /* want reply */
3912 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
3914 ssh2_pkt_addstring("shell");
3915 ssh2_pkt_addbool(1); /* want reply */
3919 crWaitUntilV(ispkt);
3920 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3921 unsigned i = ssh2_pkt_getuint32();
3922 struct ssh_channel *c;
3923 c = find234(ssh_channels, &i, ssh_channelfind);
3925 continue; /* nonexistent channel */
3926 c->v2.remwindow += ssh2_pkt_getuint32();
3928 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3929 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3930 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3931 bombout(("Server got confused by shell/command request"));
3934 bombout(("Server refused to start a shell/command"));
3937 logevent("Started a shell/command");
3940 ssh_state = SSH_STATE_SESSION;
3944 ssh_special(TS_EOF);
3949 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
3952 static int try_send;
3956 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3957 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3960 unsigned i = ssh2_pkt_getuint32();
3961 struct ssh_channel *c;
3962 c = find234(ssh_channels, &i, ssh_channelfind);
3964 continue; /* nonexistent channel */
3965 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3966 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3967 continue; /* extended but not stderr */
3968 ssh2_pkt_getstring(&data, &length);
3971 case CHAN_MAINSESSION:
3972 from_backend(pktin.type ==
3973 SSH2_MSG_CHANNEL_EXTENDED_DATA, data,
3977 x11_send(c->u.x11.s, data, length);
3980 while (length > 0) {
3981 if (c->u.a.lensofar < 4) {
3982 int l = min(4 - c->u.a.lensofar, length);
3983 memcpy(c->u.a.msglen + c->u.a.lensofar,
3987 c->u.a.lensofar += l;
3989 if (c->u.a.lensofar == 4) {
3991 4 + GET_32BIT(c->u.a.msglen);
3992 c->u.a.message = smalloc(c->u.a.totallen);
3993 memcpy(c->u.a.message, c->u.a.msglen, 4);
3995 if (c->u.a.lensofar >= 4 && length > 0) {
3997 min(c->u.a.totallen - c->u.a.lensofar,
3999 memcpy(c->u.a.message + c->u.a.lensofar,
4003 c->u.a.lensofar += l;
4005 if (c->u.a.lensofar == c->u.a.totallen) {
4006 void *reply, *sentreply;
4008 agent_query(c->u.a.message,
4009 c->u.a.totallen, &reply,
4014 /* Fake SSH_AGENT_FAILURE. */
4015 sentreply = "\0\0\0\1\5";
4018 ssh2_add_channel_data(c, sentreply,
4023 sfree(c->u.a.message);
4024 c->u.a.lensofar = 0;
4030 * Enlarge the window again at the remote
4031 * side, just in case it ever runs down and
4032 * they fail to send us any more data.
4034 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4035 ssh2_pkt_adduint32(c->remoteid);
4036 ssh2_pkt_adduint32(length);
4039 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4040 ssh_state = SSH_STATE_CLOSED;
4041 logevent("Received disconnect message");
4043 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
4044 continue; /* exit status et al; ignore (FIXME?) */
4045 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4046 unsigned i = ssh2_pkt_getuint32();
4047 struct ssh_channel *c;
4049 c = find234(ssh_channels, &i, ssh_channelfind);
4051 continue; /* nonexistent channel */
4053 if (c->type == CHAN_X11) {
4055 * Remote EOF on an X11 channel means we should
4056 * wrap up and close the channel ourselves.
4058 x11_close(c->u.x11.s);
4060 } else if (c->type == CHAN_AGENT) {
4063 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4064 unsigned i = ssh2_pkt_getuint32();
4065 struct ssh_channel *c;
4067 c = find234(ssh_channels, &i, ssh_channelfind);
4069 continue; /* nonexistent channel */
4070 if (c->closes == 0) {
4071 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4072 ssh2_pkt_adduint32(c->remoteid);
4075 /* Do pre-close processing on the channel. */
4077 case CHAN_MAINSESSION:
4078 break; /* nothing to see here, move along */
4084 del234(ssh_channels, c);
4085 sfree(c->v2.outbuffer);
4089 * See if that was the last channel left open.
4091 if (count234(ssh_channels) == 0) {
4092 logevent("All channels closed. Disconnecting");
4093 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4094 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4095 ssh2_pkt_addstring("All open channels closed");
4096 ssh2_pkt_addstring("en"); /* language tag */
4098 ssh_state = SSH_STATE_CLOSED;
4101 continue; /* remote sends close; ignore (FIXME) */
4102 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4103 unsigned i = ssh2_pkt_getuint32();
4104 struct ssh_channel *c;
4105 c = find234(ssh_channels, &i, ssh_channelfind);
4107 continue; /* nonexistent channel */
4108 c->v2.remwindow += ssh2_pkt_getuint32();
4110 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
4114 struct ssh_channel *c;
4115 ssh2_pkt_getstring(&type, &typelen);
4116 c = smalloc(sizeof(struct ssh_channel));
4118 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4119 if (!ssh_X11_fwd_enabled)
4120 error = "X11 forwarding is not enabled";
4121 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4123 error = "Unable to open an X11 connection";
4127 } else if (typelen == 22 &&
4128 !memcmp(type, "auth-agent@openssh.com", 3)) {
4129 if (!ssh_agentfwd_enabled)
4130 error = "Agent forwarding is not enabled";
4132 c->type = CHAN_AGENT; /* identify channel type */
4133 c->u.a.lensofar = 0;
4136 error = "Unsupported channel type requested";
4139 c->remoteid = ssh2_pkt_getuint32();
4141 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4142 ssh2_pkt_adduint32(c->remoteid);
4143 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4144 ssh2_pkt_addstring(error);
4145 ssh2_pkt_addstring("en"); /* language tag */
4149 c->localid = alloc_channel_id();
4151 c->v2.remwindow = ssh2_pkt_getuint32();
4152 c->v2.remmaxpkt = ssh2_pkt_getuint32();
4153 c->v2.outbuffer = NULL;
4154 c->v2.outbuflen = c->v2.outbufsize = 0;
4155 add234(ssh_channels, c);
4156 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4157 ssh2_pkt_adduint32(c->remoteid);
4158 ssh2_pkt_adduint32(c->localid);
4159 ssh2_pkt_adduint32(0x8000UL); /* our window size */
4160 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4164 bombout(("Strange packet received: type %d", pktin.type));
4169 * We have spare data. Add it to the channel buffer.
4171 ssh2_add_channel_data(mainchan, in, inlen);
4176 struct ssh_channel *c;
4178 * Try to send data on all channels if we can.
4180 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
4189 * Handle the top-level SSH2 protocol.
4191 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4193 if (do_ssh2_transport(in, inlen, ispkt) == 0)
4195 do_ssh2_authconn(in, inlen, ispkt);
4199 * Called to set up the connection.
4201 * Returns an error message, or NULL on success.
4203 static char *ssh_init(char *host, int port, char **realhost)
4208 if (crypto_startup() == 0)
4209 return "Microsoft high encryption pack not installed!";
4216 p = connect_to_host(host, port, realhost);
4224 * Called to send data down the Telnet connection.
4226 static void ssh_send(char *buf, int len)
4228 if (s == NULL || ssh_protocol == NULL)
4231 ssh_protocol(buf, len, 0);
4235 * Called to set the size of the window from SSH's POV.
4237 static void ssh_size(void)
4239 switch (ssh_state) {
4240 case SSH_STATE_BEFORE_SIZE:
4241 case SSH_STATE_PREPACKET:
4242 case SSH_STATE_CLOSED:
4243 break; /* do nothing */
4244 case SSH_STATE_INTERMED:
4245 size_needed = TRUE; /* buffer for later */
4247 case SSH_STATE_SESSION:
4249 if (ssh_version == 1) {
4250 send_packet(SSH1_CMSG_WINDOW_SIZE,
4251 PKT_INT, rows, PKT_INT, cols,
4252 PKT_INT, 0, PKT_INT, 0, PKT_END);
4254 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4255 ssh2_pkt_adduint32(mainchan->remoteid);
4256 ssh2_pkt_addstring("window-change");
4257 ssh2_pkt_addbool(0);
4258 ssh2_pkt_adduint32(cols);
4259 ssh2_pkt_adduint32(rows);
4260 ssh2_pkt_adduint32(0);
4261 ssh2_pkt_adduint32(0);
4270 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4271 * can send an EOF and collect resulting output (e.g. `plink
4274 static void ssh_special(Telnet_Special code)
4276 if (code == TS_EOF) {
4277 if (ssh_state != SSH_STATE_SESSION) {
4279 * Buffer the EOF in case we are pre-SESSION, so we can
4280 * send it as soon as we reach SESSION.
4286 if (ssh_version == 1) {
4287 send_packet(SSH1_CMSG_EOF, PKT_END);
4289 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4290 ssh2_pkt_adduint32(mainchan->remoteid);
4293 logevent("Sent EOF message");
4294 } else if (code == TS_PING) {
4295 if (ssh_state == SSH_STATE_CLOSED
4296 || ssh_state == SSH_STATE_PREPACKET) return;
4297 if (ssh_version == 1) {
4298 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
4300 ssh2_pkt_init(SSH2_MSG_IGNORE);
4301 ssh2_pkt_addstring_start();
4309 static Socket ssh_socket(void)
4314 static int ssh_sendok(void)
4319 static int ssh_ldisc(int option)
4321 if (option == LD_ECHO)
4323 if (option == LD_EDIT)
4328 Backend ssh_backend = {