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_USERAUTH_INFO_REQUEST 60 /* 0x3c */
99 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
100 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
101 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
102 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
103 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
104 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
105 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
106 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
107 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
108 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
109 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
110 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
111 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
112 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
113 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
163 #define GET_32BIT(cp) \
164 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
165 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
166 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
167 ((unsigned long)(unsigned char)(cp)[3]))
169 #define PUT_32BIT(cp, value) { \
170 (cp)[0] = (unsigned char)((value) >> 24); \
171 (cp)[1] = (unsigned char)((value) >> 16); \
172 (cp)[2] = (unsigned char)((value) >> 8); \
173 (cp)[3] = (unsigned char)(value); }
175 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
177 /* Coroutine mechanics for the sillier bits of the code */
178 #define crBegin1 static int crLine = 0;
179 #define crBegin2 switch(crLine) { case 0:;
180 #define crBegin crBegin1; crBegin2;
181 #define crFinish(z) } crLine = 0; return (z)
182 #define crFinishV } crLine = 0; return
183 #define crReturn(z) \
185 crLine=__LINE__; return (z); case __LINE__:;\
189 crLine=__LINE__; return; case __LINE__:;\
191 #define crStop(z) do{ crLine = 0; return (z); }while(0)
192 #define crStopV do{ crLine = 0; return; }while(0)
193 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
194 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
196 extern char *x11_init(Socket *, char *, void *);
197 extern void x11_close(Socket);
198 extern void x11_send(Socket, char *, int);
199 extern void x11_invent_auth(char *, int, char *, int);
201 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
202 extern char *pfd_addforward(char *desthost, int destport, int port);
203 extern void pfd_close(Socket s);
204 extern void pfd_send(Socket s, char *data, int len);
205 extern void pfd_confirm(Socket s);
208 * Ciphers for SSH2. We miss out single-DES because it isn't
209 * supported; also 3DES and Blowfish are both done differently from
210 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
211 * endianness and different-sized keys.)
213 const static struct ssh2_ciphers *ciphers[] = {
219 const static struct ssh_kex *kex_algs[] = {
220 &ssh_diffiehellman_gex,
224 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
226 static void nullmac_key(unsigned char *key)
229 static void nullmac_generate(unsigned char *blk, int len,
233 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
237 const static struct ssh_mac ssh_mac_none = {
238 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
240 const static struct ssh_mac *macs[] = {
241 &ssh_sha1, &ssh_md5, &ssh_mac_none
243 const static struct ssh_mac *buggymacs[] = {
244 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
247 static void ssh_comp_none_init(void)
250 static int ssh_comp_none_block(unsigned char *block, int len,
251 unsigned char **outblock, int *outlen)
255 static int ssh_comp_none_disable(void)
259 const static struct ssh_compress ssh_comp_none = {
261 ssh_comp_none_init, ssh_comp_none_block,
262 ssh_comp_none_init, ssh_comp_none_block,
263 ssh_comp_none_disable
265 extern const struct ssh_compress ssh_zlib;
266 const static struct ssh_compress *compressions[] = {
267 &ssh_zlib, &ssh_comp_none
270 enum { /* channel types */
278 * 2-3-4 tree storing channels.
281 unsigned remoteid, localid;
284 struct ssh2_data_channel {
285 unsigned char *outbuffer;
286 unsigned outbuflen, outbufsize;
287 unsigned remwindow, remmaxpkt;
290 struct ssh_agent_channel {
291 unsigned char *message;
292 unsigned char msglen[4];
293 int lensofar, totallen;
295 struct ssh_x11_channel {
298 struct ssh_pfd_channel {
305 * 2-3-4 tree storing remote->local port forwardings (so we can
306 * reject any attempt to open a port we didn't explicitly ask to
309 struct ssh_rportfwd {
323 static SHA_State exhash, exhashbase;
325 static Socket s = NULL;
327 static unsigned char session_key[32];
328 static int ssh1_compressing;
329 static int ssh1_remote_protoflags;
330 static int ssh1_local_protoflags;
331 static int ssh_agentfwd_enabled;
332 static int ssh_X11_fwd_enabled;
333 static int ssh_remote_bugs;
334 static const struct ssh_cipher *cipher = NULL;
335 static const struct ssh2_cipher *cscipher = NULL;
336 static const struct ssh2_cipher *sccipher = NULL;
337 static const struct ssh_mac *csmac = NULL;
338 static const struct ssh_mac *scmac = NULL;
339 static const struct ssh_compress *cscomp = NULL;
340 static const struct ssh_compress *sccomp = NULL;
341 static const struct ssh_kex *kex = NULL;
342 static const struct ssh_signkey *hostkey = NULL;
343 static unsigned char ssh2_session_id[20];
344 int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
347 static char *savedhost;
348 static int savedport;
349 static int ssh_send_ok;
350 static int ssh_echoing, ssh_editing;
352 static tree234 *ssh_channels; /* indexed by local id */
353 static struct ssh_channel *mainchan; /* primary session channel */
355 static tree234 *ssh_rportfwds;
359 SSH_STATE_BEFORE_SIZE,
363 } ssh_state = SSH_STATE_PREPACKET;
365 static int size_needed = FALSE, eof_needed = FALSE;
367 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
368 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
369 static unsigned char *deferred_send_data = NULL;
370 static int deferred_len = 0, deferred_size = 0;
372 static int ssh_version;
373 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
374 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
375 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
376 static void ssh_size(void);
377 static void ssh_special(Telnet_Special);
378 static void ssh2_try_send(struct ssh_channel *c);
379 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
382 static int (*s_rdpkt) (unsigned char **data, int *datalen);
384 static struct rdpkt1_state_tag {
385 long len, pad, biglen, to_read;
386 unsigned long realcrc, gotcrc;
392 static struct rdpkt2_state_tag {
393 long len, pad, payload, packetlen, maclen;
396 unsigned long incoming_sequence;
399 static int ssh_channelcmp(void *av, void *bv)
401 struct ssh_channel *a = (struct ssh_channel *) av;
402 struct ssh_channel *b = (struct ssh_channel *) bv;
403 if (a->localid < b->localid)
405 if (a->localid > b->localid)
409 static int ssh_channelfind(void *av, void *bv)
411 unsigned *a = (unsigned *) av;
412 struct ssh_channel *b = (struct ssh_channel *) bv;
420 static int ssh_rportcmp(void *av, void *bv)
422 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
423 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
425 if ( (i = strcmp(a->host, b->host)) != 0)
426 return i < 0 ? -1 : +1;
427 if (a->port > b->port)
432 static int alloc_channel_id(void)
434 const unsigned CHANNEL_NUMBER_OFFSET = 256;
435 unsigned low, high, mid;
437 struct ssh_channel *c;
440 * First-fit allocation of channel numbers: always pick the
441 * lowest unused one. To do this, binary-search using the
442 * counted B-tree to find the largest channel ID which is in a
443 * contiguous sequence from the beginning. (Precisely
444 * everything in that sequence must have ID equal to its tree
445 * index plus CHANNEL_NUMBER_OFFSET.)
447 tsize = count234(ssh_channels);
451 while (high - low > 1) {
452 mid = (high + low) / 2;
453 c = index234(ssh_channels, mid);
454 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
455 low = mid; /* this one is fine */
457 high = mid; /* this one is past it */
460 * Now low points to either -1, or the tree index of the
461 * largest ID in the initial sequence.
464 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
465 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
467 return low + 1 + CHANNEL_NUMBER_OFFSET;
470 static void c_write(char *buf, int len)
472 if ((flags & FLAG_STDERR)) {
474 for (i = 0; i < len; i++)
476 fputc(buf[i], stderr);
479 from_backend(1, buf, len);
482 static void c_write_untrusted(char *buf, int len)
485 for (i = 0; i < len; i++) {
488 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
493 static void c_write_str(char *buf)
495 c_write(buf, strlen(buf));
499 * Collect incoming data in the incoming packet buffer.
500 * Decipher and verify the packet when it is completely read.
501 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
502 * Update the *data and *datalen variables.
503 * Return the additional nr of bytes needed, or 0 when
504 * a complete packet is available.
506 static int ssh1_rdpkt(unsigned char **data, int *datalen)
508 struct rdpkt1_state_tag *st = &rdpkt1_state;
517 for (st->i = st->len = 0; st->i < 4; st->i++) {
518 while ((*datalen) == 0)
520 st->len = (st->len << 8) + **data;
521 (*data)++, (*datalen)--;
525 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
526 st->len = 0x300; /* big enough to carry to end */
530 st->pad = 8 - (st->len % 8);
531 st->biglen = st->len + st->pad;
532 pktin.length = st->len - 5;
534 if (pktin.maxlen < st->biglen) {
535 pktin.maxlen = st->biglen;
536 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
537 srealloc(pktin.data, st->biglen + APIEXTRA));
539 fatalbox("Out of memory");
542 st->to_read = st->biglen;
544 while (st->to_read > 0) {
545 st->chunk = st->to_read;
546 while ((*datalen) == 0)
547 crReturn(st->to_read);
548 if (st->chunk > (*datalen))
549 st->chunk = (*datalen);
550 memcpy(st->p, *data, st->chunk);
552 *datalen -= st->chunk;
554 st->to_read -= st->chunk;
558 cipher->decrypt(pktin.data, st->biglen);
560 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
561 dmemdump(pktin.data, st->biglen);
564 st->realcrc = crc32(pktin.data, st->biglen - 4);
565 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
566 if (st->gotcrc != st->realcrc) {
567 bombout(("Incorrect CRC received on packet"));
571 pktin.body = pktin.data + st->pad + 1;
573 if (ssh1_compressing) {
574 unsigned char *decompblk;
577 debug(("Packet payload pre-decompression:\n"));
578 dmemdump(pktin.body - 1, pktin.length + 1);
580 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
581 &decompblk, &decomplen);
583 if (pktin.maxlen < st->pad + decomplen) {
584 pktin.maxlen = st->pad + decomplen;
585 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
586 pktin.body = pktin.data + st->pad + 1;
588 fatalbox("Out of memory");
591 memcpy(pktin.body - 1, decompblk, decomplen);
593 pktin.length = decomplen - 1;
595 debug(("Packet payload post-decompression:\n"));
596 dmemdump(pktin.body - 1, pktin.length + 1);
600 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
601 pktin.type == SSH1_SMSG_STDERR_DATA ||
602 pktin.type == SSH1_MSG_DEBUG ||
603 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
604 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
605 long strlen = GET_32BIT(pktin.body);
606 if (strlen + 4 != pktin.length) {
607 bombout(("Received data packet with bogus string length"));
612 pktin.type = pktin.body[-1];
614 if (pktin.type == SSH1_MSG_DEBUG) {
615 /* log debug message */
617 int strlen = GET_32BIT(pktin.body);
618 strcpy(buf, "Remote: ");
621 memcpy(buf + 8, pktin.body + 4, strlen);
622 buf[8 + strlen] = '\0';
625 } else if (pktin.type == SSH1_MSG_IGNORE) {
630 if (pktin.type == SSH1_MSG_DISCONNECT) {
631 /* log reason code in disconnect message */
633 unsigned msglen = GET_32BIT(pktin.body);
635 strcpy(buf, "Remote sent disconnect: ");
636 nowlen = strlen(buf);
637 if (msglen > sizeof(buf) - nowlen - 1)
638 msglen = sizeof(buf) - nowlen - 1;
639 memcpy(buf + nowlen, pktin.body + 4, msglen);
640 buf[nowlen + msglen] = '\0';
647 static int ssh2_rdpkt(unsigned char **data, int *datalen)
649 struct rdpkt2_state_tag *st = &rdpkt2_state;
657 st->cipherblk = sccipher->blksize;
660 if (st->cipherblk < 8)
663 if (pktin.maxlen < st->cipherblk) {
664 pktin.maxlen = st->cipherblk;
667 NULL ? smalloc(st->cipherblk +
668 APIEXTRA) : srealloc(pktin.data,
672 fatalbox("Out of memory");
676 * Acquire and decrypt the first block of the packet. This will
677 * contain the length and padding details.
679 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
680 while ((*datalen) == 0)
681 crReturn(st->cipherblk - st->i);
682 pktin.data[st->i] = *(*data)++;
686 if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */
691 sccipher->decrypt(pktin.data, st->cipherblk);
694 * Now get the length and padding figures.
696 st->len = GET_32BIT(pktin.data);
697 st->pad = pktin.data[4];
700 * This enables us to deduce the payload length.
702 st->payload = st->len - st->pad - 1;
704 pktin.length = st->payload + 5;
707 * So now we can work out the total packet length.
709 st->packetlen = st->len + 4;
710 st->maclen = scmac ? scmac->len : 0;
713 * Adjust memory allocation if packet is too big.
715 if (pktin.maxlen < st->packetlen + st->maclen) {
716 pktin.maxlen = st->packetlen + st->maclen;
719 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
724 fatalbox("Out of memory");
728 * Read and decrypt the remainder of the packet.
730 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
732 while ((*datalen) == 0)
733 crReturn(st->packetlen + st->maclen - st->i);
734 pktin.data[st->i] = *(*data)++;
737 /* Decrypt everything _except_ the MAC. */
739 sccipher->decrypt(pktin.data + st->cipherblk,
740 st->packetlen - st->cipherblk);
743 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
744 dmemdump(pktin.data, st->packetlen);
751 && !scmac->verify(pktin.data, st->len + 4,
752 st->incoming_sequence)) {
753 bombout(("Incorrect MAC received on packet"));
756 st->incoming_sequence++; /* whether or not we MACed */
759 * Decompress packet payload.
762 unsigned char *newpayload;
764 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
765 &newpayload, &newlen)) {
766 if (pktin.maxlen < newlen + 5) {
767 pktin.maxlen = newlen + 5;
770 NULL ? smalloc(pktin.maxlen +
771 APIEXTRA) : srealloc(pktin.data,
775 fatalbox("Out of memory");
777 pktin.length = 5 + newlen;
778 memcpy(pktin.data + 5, newpayload, newlen);
780 debug(("Post-decompression payload:\n"));
781 dmemdump(pktin.data + 5, newlen);
789 pktin.type = pktin.data[5];
791 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
792 goto next_packet; /* FIXME: print DEBUG message */
794 if (pktin.type == SSH2_MSG_DISCONNECT) {
795 /* log reason code in disconnect message */
797 int reason = GET_32BIT(pktin.data + 6);
798 unsigned msglen = GET_32BIT(pktin.data + 10);
800 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
801 sprintf(buf, "Received disconnect message (%s)",
802 ssh2_disconnect_reasons[reason]);
804 sprintf(buf, "Received disconnect message (unknown type %d)",
808 strcpy(buf, "Disconnection message text: ");
809 nowlen = strlen(buf);
810 if (msglen > sizeof(buf) - nowlen - 1)
811 msglen = sizeof(buf) - nowlen - 1;
812 memcpy(buf + nowlen, pktin.data + 14, msglen);
813 buf[nowlen + msglen] = '\0';
820 static void ssh1_pktout_size(int len)
824 len += 5; /* type and CRC */
828 pktout.length = len - 5;
829 if (pktout.maxlen < biglen) {
830 pktout.maxlen = biglen;
832 /* Allocate enough buffer space for extra block
833 * for MS CryptEncrypt() */
834 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
835 srealloc(pktout.data, biglen + 12));
837 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
838 srealloc(pktout.data, biglen + 4));
841 fatalbox("Out of memory");
843 pktout.body = pktout.data + 4 + pad + 1;
846 static void s_wrpkt_start(int type, int len)
848 ssh1_pktout_size(len);
852 static int s_wrpkt_prepare(void)
854 int pad, len, biglen, i;
857 pktout.body[-1] = pktout.type;
860 debug(("Packet payload pre-compression:\n"));
861 dmemdump(pktout.body - 1, pktout.length + 1);
864 if (ssh1_compressing) {
865 unsigned char *compblk;
867 zlib_compress_block(pktout.body - 1, pktout.length + 1,
869 ssh1_pktout_size(complen - 1);
870 memcpy(pktout.body - 1, compblk, complen);
873 debug(("Packet payload post-compression:\n"));
874 dmemdump(pktout.body - 1, pktout.length + 1);
878 len = pktout.length + 5; /* type and CRC */
882 for (i = 0; i < pad; i++)
883 pktout.data[i + 4] = random_byte();
884 crc = crc32(pktout.data + 4, biglen - 4);
885 PUT_32BIT(pktout.data + biglen, crc);
886 PUT_32BIT(pktout.data, len);
889 debug(("Sending packet len=%d\n", biglen + 4));
890 dmemdump(pktout.data, biglen + 4);
893 cipher->encrypt(pktout.data + 4, biglen);
898 static void s_wrpkt(void)
901 len = s_wrpkt_prepare();
902 sk_write(s, pktout.data, len);
905 static void s_wrpkt_defer(void)
908 len = s_wrpkt_prepare();
909 if (deferred_len + len > deferred_size) {
910 deferred_size = deferred_len + len + 128;
911 deferred_send_data = srealloc(deferred_send_data, deferred_size);
913 memcpy(deferred_send_data + deferred_len, pktout.data, len);
918 * Construct a packet with the specified contents.
920 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
922 unsigned char *p, *argp, argchar;
923 unsigned long argint;
924 int pktlen, argtype, arglen;
928 while ((argtype = va_arg(ap1, int)) != PKT_END) {
931 (void) va_arg(ap1, int);
935 (void) va_arg(ap1, char);
939 (void) va_arg(ap1, unsigned char *);
940 arglen = va_arg(ap1, int);
944 argp = va_arg(ap1, unsigned char *);
945 arglen = strlen(argp);
946 pktlen += 4 + arglen;
949 bn = va_arg(ap1, Bignum);
950 pktlen += ssh1_bignum_length(bn);
957 s_wrpkt_start(pkttype, pktlen);
960 while ((argtype = va_arg(ap2, int)) != PKT_END) {
963 argint = va_arg(ap2, int);
964 PUT_32BIT(p, argint);
968 argchar = va_arg(ap2, unsigned char);
973 argp = va_arg(ap2, unsigned char *);
974 arglen = va_arg(ap2, int);
975 memcpy(p, argp, arglen);
979 argp = va_arg(ap2, unsigned char *);
980 arglen = strlen(argp);
981 PUT_32BIT(p, arglen);
982 memcpy(p + 4, argp, arglen);
986 bn = va_arg(ap2, Bignum);
987 p += ssh1_write_bignum(p, bn);
993 static void send_packet(int pkttype, ...)
996 va_start(ap1, pkttype);
997 va_start(ap2, pkttype);
998 construct_packet(pkttype, ap1, ap2);
1002 static void defer_packet(int pkttype, ...)
1005 va_start(ap1, pkttype);
1006 va_start(ap2, pkttype);
1007 construct_packet(pkttype, ap1, ap2);
1011 static int ssh_versioncmp(char *a, char *b)
1014 unsigned long av, bv;
1016 av = strtoul(a, &ae, 10);
1017 bv = strtoul(b, &be, 10);
1019 return (av < bv ? -1 : +1);
1024 av = strtoul(ae, &ae, 10);
1025 bv = strtoul(be, &be, 10);
1027 return (av < bv ? -1 : +1);
1033 * Utility routines for putting an SSH-protocol `string' and
1034 * `uint32' into a SHA state.
1037 static void sha_string(SHA_State * s, void *str, int len)
1039 unsigned char lenblk[4];
1040 PUT_32BIT(lenblk, len);
1041 SHA_Bytes(s, lenblk, 4);
1042 SHA_Bytes(s, str, len);
1045 static void sha_uint32(SHA_State * s, unsigned i)
1047 unsigned char intblk[4];
1048 PUT_32BIT(intblk, i);
1049 SHA_Bytes(s, intblk, 4);
1053 * SSH2 packet construction functions.
1055 static void ssh2_pkt_ensure(int length)
1057 if (pktout.maxlen < length) {
1058 pktout.maxlen = length + 256;
1061 NULL ? smalloc(pktout.maxlen +
1062 APIEXTRA) : srealloc(pktout.data,
1066 fatalbox("Out of memory");
1069 static void ssh2_pkt_adddata(void *data, int len)
1071 pktout.length += len;
1072 ssh2_pkt_ensure(pktout.length);
1073 memcpy(pktout.data + pktout.length - len, data, len);
1075 static void ssh2_pkt_addbyte(unsigned char byte)
1077 ssh2_pkt_adddata(&byte, 1);
1079 static void ssh2_pkt_init(int pkt_type)
1082 ssh2_pkt_addbyte((unsigned char) pkt_type);
1084 static void ssh2_pkt_addbool(unsigned char value)
1086 ssh2_pkt_adddata(&value, 1);
1088 static void ssh2_pkt_adduint32(unsigned long value)
1091 PUT_32BIT(x, value);
1092 ssh2_pkt_adddata(x, 4);
1094 static void ssh2_pkt_addstring_start(void)
1096 ssh2_pkt_adduint32(0);
1097 pktout.savedpos = pktout.length;
1099 static void ssh2_pkt_addstring_str(char *data)
1101 ssh2_pkt_adddata(data, strlen(data));
1102 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1103 pktout.length - pktout.savedpos);
1105 static void ssh2_pkt_addstring_data(char *data, int len)
1107 ssh2_pkt_adddata(data, len);
1108 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1109 pktout.length - pktout.savedpos);
1111 static void ssh2_pkt_addstring(char *data)
1113 ssh2_pkt_addstring_start();
1114 ssh2_pkt_addstring_str(data);
1116 static char *ssh2_mpint_fmt(Bignum b, int *len)
1119 int i, n = (bignum_bitcount(b) + 7) / 8;
1122 fatalbox("out of memory");
1124 for (i = 1; i <= n; i++)
1125 p[i] = bignum_byte(b, n - i);
1127 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1129 memmove(p, p + i, n + 1 - i);
1133 static void ssh2_pkt_addmp(Bignum b)
1137 p = ssh2_mpint_fmt(b, &len);
1138 ssh2_pkt_addstring_start();
1139 ssh2_pkt_addstring_data(p, len);
1144 * Construct an SSH2 final-form packet: compress it, encrypt it,
1145 * put the MAC on it. Final packet, ready to be sent, is stored in
1146 * pktout.data. Total length is returned.
1148 static int ssh2_pkt_construct(void)
1150 int cipherblk, maclen, padding, i;
1151 static unsigned long outgoing_sequence = 0;
1154 * Compress packet payload.
1157 debug(("Pre-compression payload:\n"));
1158 dmemdump(pktout.data + 5, pktout.length - 5);
1161 unsigned char *newpayload;
1163 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1164 &newpayload, &newlen)) {
1166 ssh2_pkt_adddata(newpayload, newlen);
1172 * Add padding. At least four bytes, and must also bring total
1173 * length (minus MAC) up to a multiple of the block size.
1175 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1176 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1179 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1180 maclen = csmac ? csmac->len : 0;
1181 ssh2_pkt_ensure(pktout.length + padding + maclen);
1182 pktout.data[4] = padding;
1183 for (i = 0; i < padding; i++)
1184 pktout.data[pktout.length + i] = random_byte();
1185 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1187 csmac->generate(pktout.data, pktout.length + padding,
1189 outgoing_sequence++; /* whether or not we MACed */
1192 debug(("Sending packet len=%d\n", pktout.length + padding));
1193 dmemdump(pktout.data, pktout.length + padding);
1197 cscipher->encrypt(pktout.data, pktout.length + padding);
1199 /* Ready-to-send packet starts at pktout.data. We return length. */
1200 return pktout.length + padding + maclen;
1204 * Construct and send an SSH2 packet immediately.
1206 static void ssh2_pkt_send(void)
1208 int len = ssh2_pkt_construct();
1209 sk_write(s, pktout.data, len);
1213 * Construct an SSH2 packet and add it to a deferred data block.
1214 * Useful for sending multiple packets in a single sk_write() call,
1215 * to prevent a traffic-analysing listener from being able to work
1216 * out the length of any particular packet (such as the password
1219 * Note that because SSH2 sequence-numbers its packets, this can
1220 * NOT be used as an m4-style `defer' allowing packets to be
1221 * constructed in one order and sent in another.
1223 static void ssh2_pkt_defer(void)
1225 int len = ssh2_pkt_construct();
1226 if (deferred_len + len > deferred_size) {
1227 deferred_size = deferred_len + len + 128;
1228 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1230 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1231 deferred_len += len;
1235 * Send the whole deferred data block constructed by
1236 * ssh2_pkt_defer() or SSH1's defer_packet().
1238 static void ssh_pkt_defersend(void)
1240 sk_write(s, deferred_send_data, deferred_len);
1241 deferred_len = deferred_size = 0;
1242 sfree(deferred_send_data);
1243 deferred_send_data = NULL;
1247 void bndebug(char *string, Bignum b)
1251 p = ssh2_mpint_fmt(b, &len);
1252 debug(("%s", string));
1253 for (i = 0; i < len; i++)
1254 debug((" %02x", p[i]));
1260 static void sha_mpint(SHA_State * s, Bignum b)
1264 p = ssh2_mpint_fmt(b, &len);
1265 sha_string(s, p, len);
1270 * SSH2 packet decode functions.
1272 static unsigned long ssh2_pkt_getuint32(void)
1274 unsigned long value;
1275 if (pktin.length - pktin.savedpos < 4)
1276 return 0; /* arrgh, no way to decline (FIXME?) */
1277 value = GET_32BIT(pktin.data + pktin.savedpos);
1278 pktin.savedpos += 4;
1281 static int ssh2_pkt_getbool(void)
1283 unsigned long value;
1284 if (pktin.length - pktin.savedpos < 1)
1285 return 0; /* arrgh, no way to decline (FIXME?) */
1286 value = pktin.data[pktin.savedpos] != 0;
1290 static void ssh2_pkt_getstring(char **p, int *length)
1293 if (pktin.length - pktin.savedpos < 4)
1295 *length = GET_32BIT(pktin.data + pktin.savedpos);
1296 pktin.savedpos += 4;
1297 if (pktin.length - pktin.savedpos < *length)
1299 *p = pktin.data + pktin.savedpos;
1300 pktin.savedpos += *length;
1302 static Bignum ssh2_pkt_getmp(void)
1308 ssh2_pkt_getstring(&p, &length);
1312 bombout(("internal error: Can't handle negative mpints"));
1315 b = bignum_from_bytes(p, length);
1320 * Examine the remote side's version string and compare it against
1321 * a list of known buggy implementations.
1323 static void ssh_detect_bugs(char *vstring)
1325 char *imp; /* pointer to implementation part */
1327 imp += strcspn(imp, "-");
1330 imp += strcspn(imp, "-");
1334 ssh_remote_bugs = 0;
1336 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1337 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1338 !strcmp(imp, "1.2.22")) {
1340 * These versions don't support SSH1_MSG_IGNORE, so we have
1341 * to use a different defence against password length
1344 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1345 logevent("We believe remote version has SSH1 ignore bug");
1348 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1349 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1350 !strncmp(imp, "2.1 ", 4)) {
1352 * These versions have the HMAC bug.
1354 ssh_remote_bugs |= BUG_SSH2_HMAC;
1355 logevent("We believe remote version has SSH2 HMAC bug");
1359 static int do_ssh_init(unsigned char c)
1362 static char version[10];
1363 static char *vstring;
1364 static int vstrsize;
1370 /* Search for the string "SSH-" in the input. */
1373 static const int transS[] = { 1, 2, 2, 1 };
1374 static const int transH[] = { 0, 0, 3, 0 };
1375 static const int transminus[] = { 0, 0, 0, -1 };
1386 crReturn(1); /* get another character */
1389 vstring = smalloc(16);
1391 strcpy(vstring, "SSH-");
1395 crReturn(1); /* get another char */
1396 if (vslen >= vstrsize - 1) {
1398 vstring = srealloc(vstring, vstrsize);
1400 vstring[vslen++] = c;
1405 } else if (i < sizeof(version) - 1)
1407 } else if (c == '\n')
1411 ssh_agentfwd_enabled = FALSE;
1412 rdpkt2_state.incoming_sequence = 0;
1415 vlog = smalloc(20 + vslen);
1416 sprintf(vlog, "Server version: %s", vstring);
1417 ssh_detect_bugs(vstring);
1418 vlog[strcspn(vlog, "\r\n")] = '\0';
1423 * Server version "1.99" means we can choose whether we use v1
1424 * or v2 protocol. Choice is based on cfg.sshprot.
1426 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1428 * This is a v2 server. Begin v2 protocol.
1430 char verstring[80], vlog[100];
1431 sprintf(verstring, "SSH-2.0-%s", sshver);
1432 SHA_Init(&exhashbase);
1434 * Hash our version string and their version string.
1436 sha_string(&exhashbase, verstring, strlen(verstring));
1437 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1438 sprintf(vlog, "We claim version: %s", verstring);
1440 strcat(verstring, "\n");
1441 logevent("Using SSH protocol version 2");
1442 sk_write(s, verstring, strlen(verstring));
1443 ssh_protocol = ssh2_protocol;
1445 s_rdpkt = ssh2_rdpkt;
1448 * This is a v1 server. Begin v1 protocol.
1450 char verstring[80], vlog[100];
1451 sprintf(verstring, "SSH-%s-%s",
1452 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1454 sprintf(vlog, "We claim version: %s", verstring);
1456 strcat(verstring, "\n");
1457 logevent("Using SSH protocol version 1");
1458 sk_write(s, verstring, strlen(verstring));
1459 ssh_protocol = ssh1_protocol;
1461 s_rdpkt = ssh1_rdpkt;
1463 ssh_state = SSH_STATE_BEFORE_SIZE;
1470 static void ssh_gotdata(unsigned char *data, int datalen)
1475 * To begin with, feed the characters one by one to the
1476 * protocol initialisation / selection function do_ssh_init().
1477 * When that returns 0, we're done with the initial greeting
1478 * exchange and can move on to packet discipline.
1483 crReturnV; /* more data please */
1484 ret = do_ssh_init(*data);
1492 * We emerge from that loop when the initial negotiation is
1493 * over and we have selected an s_rdpkt function. Now pass
1494 * everything to s_rdpkt, and then pass the resulting packets
1495 * to the proper protocol handler.
1500 while (datalen > 0) {
1501 if (s_rdpkt(&data, &datalen) == 0) {
1502 ssh_protocol(NULL, 0, 1);
1503 if (ssh_state == SSH_STATE_CLOSED) {
1513 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1516 ssh_state = SSH_STATE_CLOSED;
1522 /* A socket error has occurred. */
1523 connection_fatal(error_msg);
1525 /* Otherwise, the remote side closed the connection normally. */
1530 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1532 ssh_gotdata(data, len);
1533 if (ssh_state == SSH_STATE_CLOSED) {
1544 * Connect to specified host and port.
1545 * Returns an error message, or NULL on success.
1546 * Also places the canonical host name into `realhost'. It must be
1547 * freed by the caller.
1549 static char *connect_to_host(char *host, int port, char **realhost)
1551 static struct plug_function_table fn_table = {
1554 }, *fn_table_ptr = &fn_table;
1563 savedhost = smalloc(1 + strlen(host));
1565 fatalbox("Out of memory");
1566 strcpy(savedhost, host);
1569 port = 22; /* default ssh port */
1582 addr = sk_namelookup(host, realhost);
1583 if ((err = sk_addr_error(addr)))
1587 *realhost = strdup(FWhost);
1593 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1594 if ((err = sk_socket_error(s)))
1598 sk_write(s, "connect ", 8);
1599 sk_write(s, FWhost, strlen(FWhost));
1602 sprintf(buf, " %d\n", FWport);
1603 sk_write(s, buf, strlen(buf));
1611 * Handle the key exchange and user authentication phases.
1613 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1617 static unsigned char *rsabuf, *keystr1, *keystr2;
1618 unsigned char cookie[8];
1619 struct RSAKey servkey, hostkey;
1620 struct MD5Context md5c;
1621 static unsigned long supported_ciphers_mask, supported_auths_mask;
1622 static int tried_publickey;
1623 static unsigned char session_id[16];
1624 static int cipher_type;
1625 static char username[100];
1632 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1633 bombout(("Public key packet not received"));
1637 logevent("Received public keys");
1639 memcpy(cookie, pktin.body, 8);
1641 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1642 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1645 * Log the host key fingerprint.
1649 logevent("Host key fingerprint is:");
1650 strcpy(logmsg, " ");
1651 hostkey.comment = NULL;
1652 rsa_fingerprint(logmsg + strlen(logmsg),
1653 sizeof(logmsg) - strlen(logmsg), &hostkey);
1657 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1658 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1659 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1661 ssh1_local_protoflags =
1662 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1663 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1666 MD5Update(&md5c, keystr2, hostkey.bytes);
1667 MD5Update(&md5c, keystr1, servkey.bytes);
1668 MD5Update(&md5c, pktin.body, 8);
1669 MD5Final(session_id, &md5c);
1671 for (i = 0; i < 32; i++)
1672 session_key[i] = random_byte();
1674 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1676 rsabuf = smalloc(len);
1678 fatalbox("Out of memory");
1681 * Verify the host key.
1685 * First format the key into a string.
1687 int len = rsastr_len(&hostkey);
1688 char fingerprint[100];
1689 char *keystr = smalloc(len);
1691 fatalbox("Out of memory");
1692 rsastr_fmt(keystr, &hostkey);
1693 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1694 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1699 for (i = 0; i < 32; i++) {
1700 rsabuf[i] = session_key[i];
1702 rsabuf[i] ^= session_id[i];
1705 if (hostkey.bytes > servkey.bytes) {
1706 rsaencrypt(rsabuf, 32, &servkey);
1707 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1709 rsaencrypt(rsabuf, 32, &hostkey);
1710 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1713 logevent("Encrypted session key");
1715 switch (cfg.cipher) {
1716 case CIPHER_BLOWFISH:
1717 cipher_type = SSH_CIPHER_BLOWFISH;
1720 cipher_type = SSH_CIPHER_DES;
1723 cipher_type = SSH_CIPHER_3DES;
1726 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1727 cipher_type = SSH_CIPHER_3DES;
1730 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1732 ("Selected cipher not supported, falling back to 3DES\r\n");
1733 cipher_type = SSH_CIPHER_3DES;
1734 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1735 bombout(("Server violates SSH 1 protocol by "
1736 "not supporting 3DES encryption"));
1740 switch (cipher_type) {
1741 case SSH_CIPHER_3DES:
1742 logevent("Using 3DES encryption");
1744 case SSH_CIPHER_DES:
1745 logevent("Using single-DES encryption");
1747 case SSH_CIPHER_BLOWFISH:
1748 logevent("Using Blowfish encryption");
1752 send_packet(SSH1_CMSG_SESSION_KEY,
1753 PKT_CHAR, cipher_type,
1754 PKT_DATA, cookie, 8,
1755 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1756 PKT_DATA, rsabuf, len,
1757 PKT_INT, ssh1_local_protoflags, PKT_END);
1759 logevent("Trying to enable encryption...");
1763 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1764 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
1765 cipher->sesskey(session_key);
1769 if (pktin.type != SSH1_SMSG_SUCCESS) {
1770 bombout(("Encryption not successfully enabled"));
1774 logevent("Successfully started encryption");
1780 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1782 if (!ssh_get_line("login as: ",
1783 username, sizeof(username), FALSE)) {
1785 * get_line failed to get a username.
1788 logevent("No username provided. Abandoning session.");
1789 ssh_state = SSH_STATE_CLOSED;
1793 c_write_str("login as: ");
1796 crWaitUntil(!ispkt);
1798 switch (c = *in++) {
1807 c_write_str("\b \b");
1814 c_write_str("\b \b");
1824 if (((c >= ' ' && c <= '~') ||
1825 ((unsigned char) c >= 160))
1826 && pos < sizeof(username)-1) {
1827 username[pos++] = c;
1833 c_write_str("\r\n");
1834 username[strcspn(username, "\n\r")] = '\0';
1837 strncpy(username, cfg.username, 99);
1838 username[99] = '\0';
1841 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1843 char userlog[22 + sizeof(username)];
1844 sprintf(userlog, "Sent username \"%s\"", username);
1846 if (flags & FLAG_INTERACTIVE &&
1847 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1848 strcat(userlog, "\r\n");
1849 c_write_str(userlog);
1856 tried_publickey = 0;
1858 while (pktin.type == SSH1_SMSG_FAILURE) {
1859 static char password[100];
1860 static char prompt[200];
1863 static int pwpkt_type;
1865 * Show password prompt, having first obtained it via a TIS
1866 * or CryptoCard exchange if we're doing TIS or CryptoCard
1869 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1870 if (agent_exists()) {
1872 * Attempt RSA authentication using Pageant.
1874 static unsigned char request[5], *response, *p;
1875 static int responselen;
1876 static int i, nkeys;
1877 static int authed = FALSE;
1880 logevent("Pageant is running. Requesting keys.");
1882 /* Request the keys held by the agent. */
1883 PUT_32BIT(request, 1);
1884 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1885 agent_query(request, 5, &r, &responselen);
1886 response = (unsigned char *) r;
1887 if (response && responselen >= 5 &&
1888 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
1890 nkeys = GET_32BIT(p);
1894 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1897 for (i = 0; i < nkeys; i++) {
1898 static struct RSAKey key;
1899 static Bignum challenge;
1900 static char *commentp;
1901 static int commentlen;
1905 sprintf(buf, "Trying Pageant key #%d", i);
1909 p += ssh1_read_bignum(p, &key.exponent);
1910 p += ssh1_read_bignum(p, &key.modulus);
1911 commentlen = GET_32BIT(p);
1915 send_packet(SSH1_CMSG_AUTH_RSA,
1916 PKT_BIGNUM, key.modulus, PKT_END);
1918 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1919 logevent("Key refused");
1922 logevent("Received RSA challenge");
1923 ssh1_read_bignum(pktin.body, &challenge);
1925 char *agentreq, *q, *ret;
1928 len = 1 + 4; /* message type, bit count */
1929 len += ssh1_bignum_length(key.exponent);
1930 len += ssh1_bignum_length(key.modulus);
1931 len += ssh1_bignum_length(challenge);
1932 len += 16; /* session id */
1933 len += 4; /* response format */
1934 agentreq = smalloc(4 + len);
1935 PUT_32BIT(agentreq, len);
1937 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1938 PUT_32BIT(q, bignum_bitcount(key.modulus));
1940 q += ssh1_write_bignum(q, key.exponent);
1941 q += ssh1_write_bignum(q, key.modulus);
1942 q += ssh1_write_bignum(q, challenge);
1943 memcpy(q, session_id, 16);
1945 PUT_32BIT(q, 1); /* response format */
1946 agent_query(agentreq, len + 4, &vret, &retlen);
1950 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1951 logevent("Sending Pageant's response");
1952 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1953 PKT_DATA, ret + 5, 16,
1957 if (pktin.type == SSH1_SMSG_SUCCESS) {
1959 ("Pageant's response accepted");
1960 if (flags & FLAG_VERBOSE) {
1962 ("Authenticated using RSA key \"");
1963 c_write(commentp, commentlen);
1964 c_write_str("\" from agent\r\n");
1969 ("Pageant's response not accepted");
1972 ("Pageant failed to answer challenge");
1976 logevent("No reply received from Pageant");
1979 freebn(key.exponent);
1980 freebn(key.modulus);
1989 if (*cfg.keyfile && !tried_publickey)
1990 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1992 if (pktin.type == SSH1_SMSG_FAILURE &&
1994 (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
1995 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1996 logevent("Requested TIS authentication");
1997 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1999 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2000 logevent("TIS authentication declined");
2001 if (flags & FLAG_INTERACTIVE)
2002 c_write_str("TIS authentication refused.\r\n");
2004 int challengelen = ((pktin.body[0] << 24) |
2005 (pktin.body[1] << 16) |
2006 (pktin.body[2] << 8) |
2008 logevent("Received TIS challenge");
2009 if (challengelen > sizeof(prompt) - 1)
2010 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2011 memcpy(prompt, pktin.body + 4, challengelen);
2012 prompt[challengelen] = '\0';
2015 if (pktin.type == SSH1_SMSG_FAILURE &&
2017 (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
2018 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2019 logevent("Requested CryptoCard authentication");
2020 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2022 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2023 logevent("CryptoCard authentication declined");
2024 c_write_str("CryptoCard authentication refused.\r\n");
2026 int challengelen = ((pktin.body[0] << 24) |
2027 (pktin.body[1] << 16) |
2028 (pktin.body[2] << 8) |
2030 logevent("Received CryptoCard challenge");
2031 if (challengelen > sizeof(prompt) - 1)
2032 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2033 memcpy(prompt, pktin.body + 4, challengelen);
2034 strncpy(prompt + challengelen, "\r\nResponse : ",
2035 sizeof(prompt) - challengelen);
2036 prompt[sizeof(prompt) - 1] = '\0';
2039 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2040 sprintf(prompt, "%.90s@%.90s's password: ",
2041 username, savedhost);
2043 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2044 char *comment = NULL;
2045 if (flags & FLAG_VERBOSE)
2046 c_write_str("Trying public key authentication.\r\n");
2047 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2048 if (flags & FLAG_VERBOSE)
2049 c_write_str("No passphrase required.\r\n");
2052 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2057 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2059 * get_line failed to get a password (for example
2060 * because one was supplied on the command line
2061 * which has already failed to work). Terminate.
2063 send_packet(SSH1_MSG_DISCONNECT,
2064 PKT_STR, "No more passwords available to try",
2066 connection_fatal("Unable to authenticate");
2067 ssh_state = SSH_STATE_CLOSED;
2071 c_write_str(prompt);
2075 crWaitUntil(!ispkt);
2077 switch (c = *in++) {
2098 if (pos < sizeof(password)-1)
2099 password[pos++] = c;
2103 c_write_str("\r\n");
2107 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2109 * Try public key authentication with the specified
2112 static struct RSAKey pubkey;
2113 static Bignum challenge, response;
2115 static unsigned char buffer[32];
2117 tried_publickey = 1;
2118 i = loadrsakey(cfg.keyfile, &pubkey, password);
2120 c_write_str("Couldn't load public key from ");
2121 c_write_str(cfg.keyfile);
2122 c_write_str(".\r\n");
2123 continue; /* go and try password */
2126 c_write_str("Wrong passphrase.\r\n");
2127 tried_publickey = 0;
2128 continue; /* try again */
2132 * Send a public key attempt.
2134 send_packet(SSH1_CMSG_AUTH_RSA,
2135 PKT_BIGNUM, pubkey.modulus, PKT_END);
2138 if (pktin.type == SSH1_SMSG_FAILURE) {
2139 c_write_str("Server refused our public key.\r\n");
2140 continue; /* go and try password */
2142 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2143 bombout(("Bizarre response to offer of public key"));
2146 ssh1_read_bignum(pktin.body, &challenge);
2147 response = rsadecrypt(challenge, &pubkey);
2148 freebn(pubkey.private_exponent); /* burn the evidence */
2150 for (i = 0; i < 32; i++) {
2151 buffer[i] = bignum_byte(response, 31 - i);
2155 MD5Update(&md5c, buffer, 32);
2156 MD5Update(&md5c, session_id, 16);
2157 MD5Final(buffer, &md5c);
2159 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2160 PKT_DATA, buffer, 16, PKT_END);
2163 if (pktin.type == SSH1_SMSG_FAILURE) {
2164 if (flags & FLAG_VERBOSE)
2166 ("Failed to authenticate with our public key.\r\n");
2167 continue; /* go and try password */
2168 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2170 ("Bizarre response to RSA authentication response"));
2174 break; /* we're through! */
2176 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2178 * Defence against traffic analysis: we send a
2179 * whole bunch of packets containing strings of
2180 * different lengths. One of these strings is the
2181 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2182 * The others are all random data in
2183 * SSH1_MSG_IGNORE packets. This way a passive
2184 * listener can't tell which is the password, and
2185 * hence can't deduce the password length.
2187 * Anybody with a password length greater than 16
2188 * bytes is going to have enough entropy in their
2189 * password that a listener won't find it _that_
2190 * much help to know how long it is. So what we'll
2193 * - if password length < 16, we send 15 packets
2194 * containing string lengths 1 through 15
2196 * - otherwise, we let N be the nearest multiple
2197 * of 8 below the password length, and send 8
2198 * packets containing string lengths N through
2199 * N+7. This won't obscure the order of
2200 * magnitude of the password length, but it will
2201 * introduce a bit of extra uncertainty.
2203 * A few servers (the old 1.2.18 through 1.2.22)
2204 * can't deal with SSH1_MSG_IGNORE. For these
2205 * servers, we need an alternative defence. We make
2206 * use of the fact that the password is interpreted
2207 * as a C string: so we can append a NUL, then some
2210 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2215 len = strlen(password);
2216 if (len < sizeof(string)) {
2218 strcpy(string, password);
2219 len++; /* cover the zero byte */
2220 while (len < sizeof(string)) {
2221 string[len++] = (char) random_byte();
2226 send_packet(pwpkt_type, PKT_INT, len,
2227 PKT_DATA, s, len, PKT_END);
2229 int bottom, top, pwlen, i;
2232 pwlen = strlen(password);
2234 bottom = 0; /* zero length passwords are OK! :-) */
2237 bottom = pwlen & ~7;
2241 assert(pwlen >= bottom && pwlen <= top);
2243 randomstr = smalloc(top + 1);
2245 for (i = bottom; i <= top; i++) {
2247 defer_packet(pwpkt_type, PKT_STR, password,
2250 for (j = 0; j < i; j++) {
2252 randomstr[j] = random_byte();
2253 } while (randomstr[j] == '\0');
2255 randomstr[i] = '\0';
2256 defer_packet(SSH1_MSG_IGNORE,
2257 PKT_STR, randomstr, PKT_END);
2260 ssh_pkt_defersend();
2263 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2266 logevent("Sent password");
2267 memset(password, 0, strlen(password));
2269 if (pktin.type == SSH1_SMSG_FAILURE) {
2270 if (flags & FLAG_VERBOSE)
2271 c_write_str("Access denied\r\n");
2272 logevent("Authentication refused");
2273 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2274 logevent("Received disconnect request");
2275 ssh_state = SSH_STATE_CLOSED;
2277 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2278 bombout(("Strange packet received, type %d", pktin.type));
2283 logevent("Authentication successful");
2288 void sshfwd_close(struct ssh_channel *c)
2290 if (c && !c->closes) {
2291 if (ssh_version == 1) {
2292 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2295 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2296 ssh2_pkt_adduint32(c->remoteid);
2300 if (c->type == CHAN_X11) {
2302 logevent("Forwarded X11 connection terminated");
2303 } else if (c->type == CHAN_SOCKDATA) {
2305 logevent("Forwarded port closed");
2310 void sshfwd_write(struct ssh_channel *c, char *buf, int len)
2312 if (ssh_version == 1) {
2313 send_packet(SSH1_MSG_CHANNEL_DATA,
2314 PKT_INT, c->remoteid,
2315 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2317 ssh2_add_channel_data(c, buf, len);
2322 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2328 while (!do_ssh1_login(in, inlen, ispkt)) {
2331 if (ssh_state == SSH_STATE_CLOSED)
2334 if (cfg.agentfwd && agent_exists()) {
2335 logevent("Requesting agent forwarding");
2336 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2340 if (pktin.type != SSH1_SMSG_SUCCESS
2341 && pktin.type != SSH1_SMSG_FAILURE) {
2342 bombout(("Protocol confusion"));
2344 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2345 logevent("Agent forwarding refused");
2347 logevent("Agent forwarding enabled");
2348 ssh_agentfwd_enabled = TRUE;
2352 if (cfg.x11_forward) {
2353 char proto[20], data[64];
2354 logevent("Requesting X11 forwarding");
2355 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2356 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2357 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2358 PKT_STR, proto, PKT_STR, data,
2359 PKT_INT, 0, PKT_END);
2361 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2362 PKT_STR, proto, PKT_STR, data, 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 logevent("X11 forwarding refused");
2374 logevent("X11 forwarding enabled");
2375 ssh_X11_fwd_enabled = TRUE;
2383 char sports[256], dports[256], host[256];
2386 ssh_rportfwds = newtree234(ssh_rportcmp);
2387 /* Add port forwardings. */
2392 while (*e && *e != '\t')
2398 while (*e && *e != ':')
2408 dport = atoi(dports);
2409 sport = atoi(sports);
2410 if (sport && dport) {
2412 pfd_addforward(host, dport, sport);
2413 sprintf(buf, "Local port %d forwarding to %s:%d",
2414 sport, host, dport);
2417 struct ssh_rportfwd *pf;
2418 pf = smalloc(sizeof(*pf));
2419 strcpy(pf->host, host);
2421 if (add234(ssh_rportfwds, pf) != pf) {
2423 "Duplicate remote port forwarding to %s:%s",
2427 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2428 sport, host, dport);
2430 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2442 send_packet(SSH1_CMSG_REQUEST_PTY,
2443 PKT_STR, cfg.termtype,
2444 PKT_INT, rows, PKT_INT, cols,
2445 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2446 ssh_state = SSH_STATE_INTERMED;
2450 if (pktin.type != SSH1_SMSG_SUCCESS
2451 && pktin.type != SSH1_SMSG_FAILURE) {
2452 bombout(("Protocol confusion"));
2454 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2455 c_write_str("Server refused to allocate pty\r\n");
2456 ssh_editing = ssh_echoing = 1;
2458 logevent("Allocated pty");
2460 ssh_editing = ssh_echoing = 1;
2463 if (cfg.compression) {
2464 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2468 if (pktin.type != SSH1_SMSG_SUCCESS
2469 && pktin.type != SSH1_SMSG_FAILURE) {
2470 bombout(("Protocol confusion"));
2472 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2473 c_write_str("Server refused to compress\r\n");
2475 logevent("Started compression");
2476 ssh1_compressing = TRUE;
2477 zlib_compress_init();
2478 zlib_decompress_init();
2481 if (*cfg.remote_cmd_ptr)
2482 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr,
2485 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2486 logevent("Started session");
2488 ssh_state = SSH_STATE_SESSION;
2492 ssh_special(TS_EOF);
2494 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2496 ssh_channels = newtree234(ssh_channelcmp);
2500 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2501 pktin.type == SSH1_SMSG_STDERR_DATA) {
2502 long len = GET_32BIT(pktin.body);
2503 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2504 pktin.body + 4, len);
2505 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2506 ssh_state = SSH_STATE_CLOSED;
2507 logevent("Received disconnect request");
2509 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2510 /* Remote side is trying to open a channel to talk to our
2511 * X-Server. Give them back a local channel number. */
2512 struct ssh_channel *c;
2514 logevent("Received X11 connect request");
2515 /* Refuse if X11 forwarding is disabled. */
2516 if (!ssh_X11_fwd_enabled) {
2517 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2518 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2519 logevent("Rejected X11 connect request");
2521 c = smalloc(sizeof(struct ssh_channel));
2523 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2524 logevent("opening X11 forward connection failed");
2526 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2527 PKT_INT, GET_32BIT(pktin.body),
2531 ("opening X11 forward connection succeeded");
2532 c->remoteid = GET_32BIT(pktin.body);
2533 c->localid = alloc_channel_id();
2535 c->type = CHAN_X11; /* identify channel type */
2536 add234(ssh_channels, c);
2537 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2538 PKT_INT, c->remoteid, PKT_INT,
2539 c->localid, PKT_END);
2540 logevent("Opened X11 forward channel");
2543 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2544 /* Remote side is trying to open a channel to talk to our
2545 * agent. Give them back a local channel number. */
2546 struct ssh_channel *c;
2548 /* Refuse if agent forwarding is disabled. */
2549 if (!ssh_agentfwd_enabled) {
2550 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2551 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2553 c = smalloc(sizeof(struct ssh_channel));
2554 c->remoteid = GET_32BIT(pktin.body);
2555 c->localid = alloc_channel_id();
2557 c->type = CHAN_AGENT; /* identify channel type */
2558 c->u.a.lensofar = 0;
2559 add234(ssh_channels, c);
2560 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2561 PKT_INT, c->remoteid, PKT_INT, c->localid,
2564 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2565 /* Remote side is trying to open a channel to talk to a
2566 * forwarded port. Give them back a local channel number. */
2567 struct ssh_channel *c;
2568 struct ssh_rportfwd pf;
2570 char host[256], buf[1024];
2572 c = smalloc(sizeof(struct ssh_channel));
2574 hostsize = GET_32BIT(pktin.body+4);
2575 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2576 if (h+1 < host+sizeof(host))
2581 port = GET_32BIT(p);
2583 strcpy(pf.host, host);
2586 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2587 sprintf(buf, "Rejected remote port open request for %s:%d",
2590 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2591 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2593 sprintf(buf, "Received remote port open request for %s:%d",
2596 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2599 sprintf(buf, "Port open failed: %s", e);
2602 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2603 PKT_INT, GET_32BIT(pktin.body),
2606 c->remoteid = GET_32BIT(pktin.body);
2607 c->localid = alloc_channel_id();
2609 c->type = CHAN_SOCKDATA; /* identify channel type */
2610 add234(ssh_channels, c);
2611 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2612 PKT_INT, c->remoteid, PKT_INT,
2613 c->localid, PKT_END);
2614 logevent("Forwarded port opened successfully");
2618 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
2619 unsigned int remoteid = GET_32BIT(pktin.body);
2620 unsigned int localid = GET_32BIT(pktin.body+4);
2621 struct ssh_channel *c;
2623 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2625 c->remoteid = localid;
2626 pfd_confirm(c->u.pfd.s);
2631 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2632 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2633 /* Remote side closes a channel. */
2634 unsigned i = GET_32BIT(pktin.body);
2635 struct ssh_channel *c;
2636 c = find234(ssh_channels, &i, ssh_channelfind);
2640 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2641 if (!(c->closes & closetype))
2642 send_packet(pktin.type, PKT_INT, c->remoteid,
2644 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2645 logevent("Forwarded X11 connection terminated");
2646 assert(c->u.x11.s != NULL);
2647 x11_close(c->u.x11.s);
2650 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
2651 logevent("Forwarded port closed");
2652 assert(c->u.pfd.s != NULL);
2653 pfd_close(c->u.pfd.s);
2656 c->closes |= closetype;
2657 if (c->closes == 3) {
2658 del234(ssh_channels, c);
2662 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2663 /* Data sent down one of our channels. */
2664 int i = GET_32BIT(pktin.body);
2665 int len = GET_32BIT(pktin.body + 4);
2666 unsigned char *p = pktin.body + 8;
2667 struct ssh_channel *c;
2668 c = find234(ssh_channels, &i, ssh_channelfind);
2672 x11_send(c->u.x11.s, p, len);
2675 pfd_send(c->u.pfd.s, p, len);
2678 /* Data for an agent message. Buffer it. */
2680 if (c->u.a.lensofar < 4) {
2681 int l = min(4 - c->u.a.lensofar, len);
2682 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2686 c->u.a.lensofar += l;
2688 if (c->u.a.lensofar == 4) {
2690 4 + GET_32BIT(c->u.a.msglen);
2691 c->u.a.message = smalloc(c->u.a.totallen);
2692 memcpy(c->u.a.message, c->u.a.msglen, 4);
2694 if (c->u.a.lensofar >= 4 && len > 0) {
2696 min(c->u.a.totallen - c->u.a.lensofar,
2698 memcpy(c->u.a.message + c->u.a.lensofar, p,
2702 c->u.a.lensofar += l;
2704 if (c->u.a.lensofar == c->u.a.totallen) {
2705 void *reply, *sentreply;
2707 agent_query(c->u.a.message,
2708 c->u.a.totallen, &reply,
2713 /* Fake SSH_AGENT_FAILURE. */
2714 sentreply = "\0\0\0\1\5";
2717 send_packet(SSH1_MSG_CHANNEL_DATA,
2718 PKT_INT, c->remoteid,
2720 PKT_DATA, sentreply, replylen,
2724 sfree(c->u.a.message);
2725 c->u.a.lensofar = 0;
2731 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2732 /* may be from EXEC_SHELL on some servers */
2733 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2734 /* may be from EXEC_SHELL on some servers
2735 * if no pty is available or in other odd cases. Ignore */
2736 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2737 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2739 bombout(("Strange packet received: type %d", pktin.type));
2744 int len = min(inlen, 512);
2745 send_packet(SSH1_CMSG_STDIN_DATA,
2746 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2757 * Utility routine for decoding comma-separated strings in KEXINIT.
2759 static int in_commasep_string(char *needle, char *haystack, int haylen)
2761 int needlen = strlen(needle);
2764 * Is it at the start of the string?
2766 if (haylen >= needlen && /* haystack is long enough */
2767 !memcmp(needle, haystack, needlen) && /* initial match */
2768 (haylen == needlen || haystack[needlen] == ',')
2769 /* either , or EOS follows */
2773 * If not, search for the next comma and resume after that.
2774 * If no comma found, terminate.
2776 while (haylen > 0 && *haystack != ',')
2777 haylen--, haystack++;
2780 haylen--, haystack++; /* skip over comma itself */
2785 * SSH2 key creation method.
2787 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
2791 /* First 20 bytes. */
2794 SHA_Bytes(&s, H, 20);
2795 SHA_Bytes(&s, &chr, 1);
2796 SHA_Bytes(&s, sessid, 20);
2797 SHA_Final(&s, keyspace);
2798 /* Next 20 bytes. */
2801 SHA_Bytes(&s, H, 20);
2802 SHA_Bytes(&s, keyspace, 20);
2803 SHA_Final(&s, keyspace + 20);
2807 * Handle the SSH2 transport layer.
2809 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2811 static int i, j, len, nbits, pbits;
2813 static Bignum p, g, e, f, K;
2814 static int kex_init_value, kex_reply_value;
2815 static const struct ssh_mac **maclist;
2817 static const struct ssh2_cipher *cscipher_tobe = NULL;
2818 static const struct ssh2_cipher *sccipher_tobe = NULL;
2819 static const struct ssh_mac *csmac_tobe = NULL;
2820 static const struct ssh_mac *scmac_tobe = NULL;
2821 static const struct ssh_compress *cscomp_tobe = NULL;
2822 static const struct ssh_compress *sccomp_tobe = NULL;
2823 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2824 static int hostkeylen, siglen;
2825 static void *hkey; /* actual host key */
2826 static unsigned char exchange_hash[20];
2827 static unsigned char keyspace[40];
2828 static const struct ssh2_ciphers *preferred_cipher;
2829 static const struct ssh_compress *preferred_comp;
2830 static int first_kex;
2837 * Set up the preferred cipher and compression.
2839 if (cfg.cipher == CIPHER_BLOWFISH) {
2840 preferred_cipher = &ssh2_blowfish;
2841 } else if (cfg.cipher == CIPHER_DES) {
2842 logevent("Single DES not supported in SSH2; using 3DES");
2843 preferred_cipher = &ssh2_3des;
2844 } else if (cfg.cipher == CIPHER_3DES) {
2845 preferred_cipher = &ssh2_3des;
2846 } else if (cfg.cipher == CIPHER_AES) {
2847 preferred_cipher = &ssh2_aes;
2849 /* Shouldn't happen, but we do want to initialise to _something_. */
2850 preferred_cipher = &ssh2_3des;
2852 if (cfg.compression)
2853 preferred_comp = &ssh_zlib;
2855 preferred_comp = &ssh_comp_none;
2858 * Be prepared to work around the buggy MAC problem.
2860 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
2861 maclist = buggymacs, nmacs = lenof(buggymacs);
2863 maclist = macs, nmacs = lenof(macs);
2867 * Construct and send our key exchange packet.
2869 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2870 for (i = 0; i < 16; i++)
2871 ssh2_pkt_addbyte((unsigned char) random_byte());
2872 /* List key exchange algorithms. */
2873 ssh2_pkt_addstring_start();
2874 for (i = 0; i < lenof(kex_algs); i++) {
2875 ssh2_pkt_addstring_str(kex_algs[i]->name);
2876 if (i < lenof(kex_algs) - 1)
2877 ssh2_pkt_addstring_str(",");
2879 /* List server host key algorithms. */
2880 ssh2_pkt_addstring_start();
2881 for (i = 0; i < lenof(hostkey_algs); i++) {
2882 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2883 if (i < lenof(hostkey_algs) - 1)
2884 ssh2_pkt_addstring_str(",");
2886 /* List client->server encryption algorithms. */
2887 ssh2_pkt_addstring_start();
2888 for (i = 0; i < lenof(ciphers) + 1; i++) {
2889 const struct ssh2_ciphers *c =
2890 i == 0 ? preferred_cipher : ciphers[i - 1];
2891 for (j = 0; j < c->nciphers; j++) {
2892 ssh2_pkt_addstring_str(c->list[j]->name);
2893 if (i < lenof(ciphers) || j < c->nciphers - 1)
2894 ssh2_pkt_addstring_str(",");
2897 /* List server->client encryption algorithms. */
2898 ssh2_pkt_addstring_start();
2899 for (i = 0; i < lenof(ciphers) + 1; i++) {
2900 const struct ssh2_ciphers *c =
2901 i == 0 ? preferred_cipher : ciphers[i - 1];
2902 for (j = 0; j < c->nciphers; j++) {
2903 ssh2_pkt_addstring_str(c->list[j]->name);
2904 if (i < lenof(ciphers) || j < c->nciphers - 1)
2905 ssh2_pkt_addstring_str(",");
2908 /* List client->server MAC algorithms. */
2909 ssh2_pkt_addstring_start();
2910 for (i = 0; i < nmacs; i++) {
2911 ssh2_pkt_addstring_str(maclist[i]->name);
2913 ssh2_pkt_addstring_str(",");
2915 /* List server->client MAC algorithms. */
2916 ssh2_pkt_addstring_start();
2917 for (i = 0; i < nmacs; i++) {
2918 ssh2_pkt_addstring_str(maclist[i]->name);
2920 ssh2_pkt_addstring_str(",");
2922 /* List client->server compression algorithms. */
2923 ssh2_pkt_addstring_start();
2924 for (i = 0; i < lenof(compressions) + 1; i++) {
2925 const struct ssh_compress *c =
2926 i == 0 ? preferred_comp : compressions[i - 1];
2927 ssh2_pkt_addstring_str(c->name);
2928 if (i < lenof(compressions))
2929 ssh2_pkt_addstring_str(",");
2931 /* List server->client compression algorithms. */
2932 ssh2_pkt_addstring_start();
2933 for (i = 0; i < lenof(compressions) + 1; i++) {
2934 const struct ssh_compress *c =
2935 i == 0 ? preferred_comp : compressions[i - 1];
2936 ssh2_pkt_addstring_str(c->name);
2937 if (i < lenof(compressions))
2938 ssh2_pkt_addstring_str(",");
2940 /* List client->server languages. Empty list. */
2941 ssh2_pkt_addstring_start();
2942 /* List server->client languages. Empty list. */
2943 ssh2_pkt_addstring_start();
2944 /* First KEX packet does _not_ follow, because we're not that brave. */
2945 ssh2_pkt_addbool(FALSE);
2947 ssh2_pkt_adduint32(0);
2949 exhash = exhashbase;
2950 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
2956 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
2959 * Now examine the other side's KEXINIT to see what we're up
2962 if (pktin.type != SSH2_MSG_KEXINIT) {
2963 bombout(("expected key exchange packet from server"));
2968 cscipher_tobe = NULL;
2969 sccipher_tobe = NULL;
2974 pktin.savedpos += 16; /* skip garbage cookie */
2975 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2976 for (i = 0; i < lenof(kex_algs); i++) {
2977 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2982 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2983 for (i = 0; i < lenof(hostkey_algs); i++) {
2984 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2985 hostkey = hostkey_algs[i];
2989 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2990 for (i = 0; i < lenof(ciphers) + 1; i++) {
2991 const struct ssh2_ciphers *c =
2992 i == 0 ? preferred_cipher : ciphers[i - 1];
2993 for (j = 0; j < c->nciphers; j++) {
2994 if (in_commasep_string(c->list[j]->name, str, len)) {
2995 cscipher_tobe = c->list[j];
3002 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3003 for (i = 0; i < lenof(ciphers) + 1; i++) {
3004 const struct ssh2_ciphers *c =
3005 i == 0 ? preferred_cipher : ciphers[i - 1];
3006 for (j = 0; j < c->nciphers; j++) {
3007 if (in_commasep_string(c->list[j]->name, str, len)) {
3008 sccipher_tobe = c->list[j];
3015 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3016 for (i = 0; i < nmacs; i++) {
3017 if (in_commasep_string(maclist[i]->name, str, len)) {
3018 csmac_tobe = maclist[i];
3022 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3023 for (i = 0; i < nmacs; i++) {
3024 if (in_commasep_string(maclist[i]->name, str, len)) {
3025 scmac_tobe = maclist[i];
3029 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3030 for (i = 0; i < lenof(compressions) + 1; i++) {
3031 const struct ssh_compress *c =
3032 i == 0 ? preferred_comp : compressions[i - 1];
3033 if (in_commasep_string(c->name, str, len)) {
3038 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3039 for (i = 0; i < lenof(compressions) + 1; i++) {
3040 const struct ssh_compress *c =
3041 i == 0 ? preferred_comp : compressions[i - 1];
3042 if (in_commasep_string(c->name, str, len)) {
3049 * Work out the number of bits of key we will need from the key
3050 * exchange. We start with the maximum key length of either
3056 csbits = cscipher_tobe->keylen;
3057 scbits = sccipher_tobe->keylen;
3058 nbits = (csbits > scbits ? csbits : scbits);
3060 /* The keys only have 160-bit entropy, since they're based on
3061 * a SHA-1 hash. So cap the key size at 160 bits. */
3066 * If we're doing Diffie-Hellman group exchange, start by
3067 * requesting a group.
3069 if (kex == &ssh_diffiehellman_gex) {
3070 logevent("Doing Diffie-Hellman group exchange");
3072 * Work out how big a DH group we will need to allow that
3075 pbits = 512 << ((nbits - 1) / 64);
3076 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3077 ssh2_pkt_adduint32(pbits);
3081 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3082 bombout(("expected key exchange group packet from server"));
3085 p = ssh2_pkt_getmp();
3086 g = ssh2_pkt_getmp();
3087 dh_setup_group(p, g);
3088 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3089 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3092 kex_init_value = SSH2_MSG_KEXDH_INIT;
3093 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3096 logevent("Doing Diffie-Hellman key exchange");
3098 * Now generate and send e for Diffie-Hellman.
3100 e = dh_create_e(nbits * 2);
3101 ssh2_pkt_init(kex_init_value);
3106 if (pktin.type != kex_reply_value) {
3107 bombout(("expected key exchange reply packet from server"));
3110 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3111 f = ssh2_pkt_getmp();
3112 ssh2_pkt_getstring(&sigdata, &siglen);
3116 sha_string(&exhash, hostkeydata, hostkeylen);
3117 if (kex == &ssh_diffiehellman_gex) {
3118 sha_uint32(&exhash, pbits);
3119 sha_mpint(&exhash, p);
3120 sha_mpint(&exhash, g);
3122 sha_mpint(&exhash, e);
3123 sha_mpint(&exhash, f);
3124 sha_mpint(&exhash, K);
3125 SHA_Final(&exhash, exchange_hash);
3130 debug(("Exchange hash is:\n"));
3131 dmemdump(exchange_hash, 20);
3134 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3136 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3137 bombout(("Server's host key did not match the signature supplied"));
3142 * Expect SSH2_MSG_NEWKEYS from server.
3145 if (pktin.type != SSH2_MSG_NEWKEYS) {
3146 bombout(("expected new-keys packet from server"));
3151 * Authenticate remote host: verify host key. (We've already
3152 * checked the signature of the exchange hash.)
3154 keystr = hostkey->fmtkey(hkey);
3155 fingerprint = hostkey->fingerprint(hkey);
3156 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3157 keystr, fingerprint);
3158 if (first_kex) { /* don't bother logging this in rekeys */
3159 logevent("Host key fingerprint is:");
3160 logevent(fingerprint);
3164 hostkey->freekey(hkey);
3167 * Send SSH2_MSG_NEWKEYS.
3169 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3173 * Create and initialise session keys.
3175 cscipher = cscipher_tobe;
3176 sccipher = sccipher_tobe;
3179 cscomp = cscomp_tobe;
3180 sccomp = sccomp_tobe;
3181 cscomp->compress_init();
3182 sccomp->decompress_init();
3184 * Set IVs after keys. Here we use the exchange hash from the
3185 * _first_ key exchange.
3188 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3189 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3190 cscipher->setcskey(keyspace);
3191 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3192 sccipher->setsckey(keyspace);
3193 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3194 cscipher->setcsiv(keyspace);
3195 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3196 sccipher->setsciv(keyspace);
3197 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3198 csmac->setcskey(keyspace);
3199 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3200 scmac->setsckey(keyspace);
3203 * If this is the first key exchange phase, we must pass the
3204 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3205 * wants to see it but because it will need time to initialise
3206 * itself before it sees an actual packet. In subsequent key
3207 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3208 * it would only confuse the layer above.
3216 * Now we're encrypting. Begin returning 1 to the protocol main
3217 * function so that other things can run on top of the
3218 * transport. If we ever see a KEXINIT, we must go back to the
3221 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3224 logevent("Server initiated key re-exchange");
3225 goto begin_key_exchange;
3231 * Add data to an SSH2 channel output buffer.
3233 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3236 if (c->v2.outbufsize < c->v2.outbuflen + len) {
3237 c->v2.outbufsize = c->v2.outbuflen + len + 1024;
3238 c->v2.outbuffer = srealloc(c->v2.outbuffer, c->v2.outbufsize);
3240 memcpy(c->v2.outbuffer + c->v2.outbuflen, buf, len);
3241 c->v2.outbuflen += len;
3245 * Attempt to send data on an SSH2 channel.
3247 static void ssh2_try_send(struct ssh_channel *c)
3249 while (c->v2.remwindow > 0 && c->v2.outbuflen > 0) {
3250 unsigned len = c->v2.remwindow;
3251 if (len > c->v2.outbuflen)
3252 len = c->v2.outbuflen;
3253 if (len > c->v2.remmaxpkt)
3254 len = c->v2.remmaxpkt;
3255 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3256 ssh2_pkt_adduint32(c->remoteid);
3257 ssh2_pkt_addstring_start();
3258 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
3260 c->v2.outbuflen -= len;
3261 memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
3262 c->v2.remwindow -= len;
3267 * Handle the SSH2 userauth and connection layers.
3269 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3272 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3274 AUTH_KEYBOARD_INTERACTIVE
3278 AUTH_TYPE_PUBLICKEY,
3279 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3280 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3282 AUTH_TYPE_KEYBOARD_INTERACTIVE
3284 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3285 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
3286 static int we_are_in;
3287 static int num_prompts, echo;
3288 static char username[100];
3289 static char pwprompt[200];
3290 static char password[100];
3295 * Request userauth protocol, and await a response to it.
3297 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3298 ssh2_pkt_addstring("ssh-userauth");
3300 crWaitUntilV(ispkt);
3301 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3302 bombout(("Server refused user authentication protocol"));
3307 * We repeat this whole loop, including the username prompt,
3308 * until we manage a successful authentication. If the user
3309 * types the wrong _password_, they are sent back to the
3310 * beginning to try another username. (If they specify a
3311 * username in the config, they are never asked, even if they
3312 * do give a wrong password.)
3314 * I think this best serves the needs of
3316 * - the people who have no configuration, no keys, and just
3317 * want to try repeated (username,password) pairs until they
3318 * type both correctly
3320 * - people who have keys and configuration but occasionally
3321 * need to fall back to passwords
3323 * - people with a key held in Pageant, who might not have
3324 * logged in to a particular machine before; so they want to
3325 * type a username, and then _either_ their key will be
3326 * accepted, _or_ they will type a password. If they mistype
3327 * the username they will want to be able to get back and
3338 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3340 if (!ssh_get_line("login as: ",
3341 username, sizeof(username), FALSE)) {
3343 * get_line failed to get a username.
3346 logevent("No username provided. Abandoning session.");
3347 ssh_state = SSH_STATE_CLOSED;
3351 c_write_str("login as: ");
3354 crWaitUntilV(!ispkt);
3356 switch (c = *in++) {
3365 c_write_str("\b \b");
3372 c_write_str("\b \b");
3382 if (((c >= ' ' && c <= '~') ||
3383 ((unsigned char) c >= 160))
3384 && pos < sizeof(username)-1) {
3385 username[pos++] = c;
3392 c_write_str("\r\n");
3393 username[strcspn(username, "\n\r")] = '\0';
3396 strncpy(username, cfg.username, 99);
3397 username[99] = '\0';
3398 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3399 sprintf(stuff, "Using username \"%s\".\r\n", username);
3405 * Send an authentication request using method "none": (a)
3406 * just in case it succeeds, and (b) so that we know what
3407 * authentication methods we can usefully try next.
3409 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3410 ssh2_pkt_addstring(username);
3411 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3412 ssh2_pkt_addstring("none"); /* method */
3414 type = AUTH_TYPE_NONE;
3418 tried_pubkey_config = FALSE;
3419 tried_agent = FALSE;
3423 * Wait for the result of the last authentication request.
3426 crWaitUntilV(ispkt);
3427 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3431 * Don't show the banner if we're operating in
3432 * non-verbose non-interactive mode. (It's probably
3433 * a script, which means nobody will read the
3434 * banner _anyway_, and moreover the printing of
3435 * the banner will screw up processing on the
3436 * output of (say) plink.)
3438 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3439 ssh2_pkt_getstring(&banner, &size);
3441 c_write_untrusted(banner, size);
3443 crWaitUntilV(ispkt);
3445 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3446 logevent("Access granted");
3451 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3453 ("Strange packet received during authentication: type %d",
3461 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3462 * we can look at the string in it and know what we can
3463 * helpfully try next.
3468 ssh2_pkt_getstring(&methods, &methlen);
3469 if (!ssh2_pkt_getbool()) {
3471 * We have received an unequivocal Access
3472 * Denied. This can translate to a variety of
3475 * - if we'd just tried "none" authentication,
3476 * it's not worth printing anything at all
3478 * - if we'd just tried a public key _offer_,
3479 * the message should be "Server refused our
3480 * key" (or no message at all if the key
3481 * came from Pageant)
3483 * - if we'd just tried anything else, the
3484 * message really should be "Access denied".
3486 * Additionally, if we'd just tried password
3487 * authentication, we should break out of this
3488 * whole loop so as to go back to the username
3491 if (type == AUTH_TYPE_NONE) {
3493 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3494 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3495 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3496 c_write_str("Server refused our key\r\n");
3497 logevent("Server refused public key");
3499 c_write_str("Access denied\r\n");
3500 logevent("Access denied");
3501 if (type == AUTH_TYPE_PASSWORD) {
3507 c_write_str("Further authentication required\r\n");
3508 logevent("Further authentication required");
3512 in_commasep_string("publickey", methods, methlen);
3514 in_commasep_string("password", methods, methlen);
3516 in_commasep_string("password", methods, methlen);
3518 in_commasep_string("keyboard-interactive", methods, methlen);
3523 if (!method && can_keyb_inter && !tried_keyb_inter) {
3524 method = AUTH_KEYBOARD_INTERACTIVE;
3525 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
3526 tried_keyb_inter = TRUE;
3528 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3529 ssh2_pkt_addstring(username);
3530 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3531 ssh2_pkt_addstring("keyboard-interactive"); /* method */
3532 ssh2_pkt_addstring(""); /* lang */
3533 ssh2_pkt_addstring("");
3536 crWaitUntilV(ispkt);
3537 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
3538 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
3540 logevent("Keyboard-interactive authentication refused");
3541 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
3545 /* We've got packet with that "interactive" info
3546 dump banners, and set its prompt as ours */
3548 char *name, *inst, *lang, *prompt;
3549 int name_len, inst_len, lang_len, prompt_len;
3550 ssh2_pkt_getstring(&name, &name_len);
3551 ssh2_pkt_getstring(&inst, &inst_len);
3552 ssh2_pkt_getstring(&lang, &lang_len);
3554 c_write_untrusted(name, name_len);
3556 c_write_untrusted(inst, inst_len);
3557 num_prompts = ssh2_pkt_getuint32();
3559 ssh2_pkt_getstring(&prompt, &prompt_len);
3560 strncpy(pwprompt, prompt, sizeof(pwprompt));
3563 echo = ssh2_pkt_getbool();
3567 if (!method && can_pubkey && agent_exists() && !tried_agent) {
3569 * Attempt public-key authentication using Pageant.
3571 static unsigned char request[5], *response, *p;
3572 static int responselen;
3573 static int i, nkeys;
3574 static int authed = FALSE;
3579 logevent("Pageant is running. Requesting keys.");
3581 /* Request the keys held by the agent. */
3582 PUT_32BIT(request, 1);
3583 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3584 agent_query(request, 5, &r, &responselen);
3585 response = (unsigned char *) r;
3586 if (response && responselen >= 5 &&
3587 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3589 nkeys = GET_32BIT(p);
3593 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3596 for (i = 0; i < nkeys; i++) {
3597 static char *pkblob, *alg, *commentp;
3598 static int pklen, alglen, commentlen;
3599 static int siglen, retlen, len;
3600 static char *q, *agentreq, *ret;
3605 sprintf(buf, "Trying Pageant key #%d", i);
3608 pklen = GET_32BIT(p);
3612 alglen = GET_32BIT(pkblob);
3614 commentlen = GET_32BIT(p);
3618 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3619 ssh2_pkt_addstring(username);
3620 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3621 ssh2_pkt_addstring("publickey"); /* method */
3622 ssh2_pkt_addbool(FALSE); /* no signature included */
3623 ssh2_pkt_addstring_start();
3624 ssh2_pkt_addstring_data(alg, alglen);
3625 ssh2_pkt_addstring_start();
3626 ssh2_pkt_addstring_data(pkblob, pklen);
3629 crWaitUntilV(ispkt);
3630 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3631 logevent("Key refused");
3635 if (flags & FLAG_VERBOSE) {
3637 ("Authenticating with public key \"");
3638 c_write(commentp, commentlen);
3639 c_write_str("\" from agent\r\n");
3643 * Server is willing to accept the key.
3644 * Construct a SIGN_REQUEST.
3646 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3647 ssh2_pkt_addstring(username);
3648 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3649 ssh2_pkt_addstring("publickey"); /* method */
3650 ssh2_pkt_addbool(TRUE);
3651 ssh2_pkt_addstring_start();
3652 ssh2_pkt_addstring_data(alg, alglen);
3653 ssh2_pkt_addstring_start();
3654 ssh2_pkt_addstring_data(pkblob, pklen);
3656 siglen = pktout.length - 5 + 4 + 20;
3657 len = 1; /* message type */
3658 len += 4 + pklen; /* key blob */
3659 len += 4 + siglen; /* data to sign */
3660 len += 4; /* flags */
3661 agentreq = smalloc(4 + len);
3662 PUT_32BIT(agentreq, len);
3664 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3665 PUT_32BIT(q, pklen);
3667 memcpy(q, pkblob, pklen);
3669 PUT_32BIT(q, siglen);
3671 /* Now the data to be signed... */
3674 memcpy(q, ssh2_session_id, 20);
3676 memcpy(q, pktout.data + 5, pktout.length - 5);
3677 q += pktout.length - 5;
3678 /* And finally the (zero) flags word. */
3680 agent_query(agentreq, len + 4, &vret, &retlen);
3684 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3685 logevent("Sending Pageant's response");
3686 ssh2_pkt_addstring_start();
3687 ssh2_pkt_addstring_data(ret + 9,
3695 ("Pageant failed to answer challenge");
3705 if (!method && can_pubkey && *cfg.keyfile
3706 && !tried_pubkey_config) {
3707 unsigned char *pub_blob;
3708 char *algorithm, *comment;
3711 tried_pubkey_config = TRUE;
3714 * Try the public key supplied in the configuration.
3716 * First, offer the public blob to see if the server is
3717 * willing to accept it.
3719 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3722 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3723 ssh2_pkt_addstring(username);
3724 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3725 ssh2_pkt_addstring("publickey"); /* method */
3726 ssh2_pkt_addbool(FALSE); /* no signature included */
3727 ssh2_pkt_addstring(algorithm);
3728 ssh2_pkt_addstring_start();
3729 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3731 logevent("Offered public key"); /* FIXME */
3733 crWaitUntilV(ispkt);
3734 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3736 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3737 continue; /* key refused; give up on it */
3740 logevent("Offer of public key accepted");
3742 * Actually attempt a serious authentication using
3745 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3747 "Passphrase for key \"%.100s\": ",
3753 c_write_str("Authenticating with public key \"");
3754 c_write_str(comment);
3755 c_write_str("\"\r\n");
3756 method = AUTH_PUBLICKEY_FILE;
3760 if (!method && can_passwd) {
3761 method = AUTH_PASSWORD;
3762 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
3769 if (!ssh_get_line(pwprompt, password,
3770 sizeof(password), TRUE)) {
3772 * get_line failed to get a password (for
3773 * example because one was supplied on the
3774 * command line which has already failed to
3777 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3778 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3780 ("No more passwords available to try");
3781 ssh2_pkt_addstring("en"); /* language tag */
3783 connection_fatal("Unable to authenticate");
3784 ssh_state = SSH_STATE_CLOSED;
3791 c_write_untrusted(pwprompt, strlen(pwprompt));
3796 crWaitUntilV(!ispkt);
3798 switch (c = *in++) {
3819 if (pos < sizeof(password)-1)
3820 password[pos++] = c;
3824 c_write_str("\r\n");
3828 if (method == AUTH_PUBLICKEY_FILE) {
3830 * We have our passphrase. Now try the actual authentication.
3832 struct ssh2_userkey *key;
3834 key = ssh2_load_userkey(cfg.keyfile, password);
3835 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3836 if (key == SSH2_WRONG_PASSPHRASE) {
3837 c_write_str("Wrong passphrase\r\n");
3838 tried_pubkey_config = FALSE;
3840 c_write_str("Unable to load private key\r\n");
3841 tried_pubkey_config = TRUE;
3843 /* Send a spurious AUTH_NONE to return to the top. */
3844 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3845 ssh2_pkt_addstring(username);
3846 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3847 ssh2_pkt_addstring("none"); /* method */
3849 type = AUTH_TYPE_NONE;
3851 unsigned char *blob, *sigdata;
3852 int blob_len, sigdata_len;
3855 * We have loaded the private key and the server
3856 * has announced that it's willing to accept it.
3857 * Hallelujah. Generate a signature and send it.
3859 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3860 ssh2_pkt_addstring(username);
3861 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3862 ssh2_pkt_addstring("publickey"); /* method */
3863 ssh2_pkt_addbool(TRUE);
3864 ssh2_pkt_addstring(key->alg->name);
3865 blob = key->alg->public_blob(key->data, &blob_len);
3866 ssh2_pkt_addstring_start();
3867 ssh2_pkt_addstring_data(blob, blob_len);
3871 * The data to be signed is:
3875 * followed by everything so far placed in the
3878 sigdata_len = pktout.length - 5 + 4 + 20;
3879 sigdata = smalloc(sigdata_len);
3880 PUT_32BIT(sigdata, 20);
3881 memcpy(sigdata + 4, ssh2_session_id, 20);
3882 memcpy(sigdata + 24, pktout.data + 5,
3885 key->alg->sign(key->data, sigdata, sigdata_len,
3887 ssh2_pkt_addstring_start();
3888 ssh2_pkt_addstring_data(blob, blob_len);
3893 type = AUTH_TYPE_PUBLICKEY;
3895 } else if (method == AUTH_PASSWORD) {
3897 * We send the password packet lumped tightly together with
3898 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3899 * string long enough to make the total length of the two
3900 * packets constant. This should ensure that a passive
3901 * listener doing traffic analyis can't work out the length
3904 * For this to work, we need an assumption about the
3905 * maximum length of the password packet. I think 256 is
3906 * pretty conservative. Anyone using a password longer than
3907 * that probably doesn't have much to worry about from
3908 * people who find out how long their password is!
3910 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3911 ssh2_pkt_addstring(username);
3912 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3913 ssh2_pkt_addstring("password");
3914 ssh2_pkt_addbool(FALSE);
3915 ssh2_pkt_addstring(password);
3918 * We'll include a string that's an exact multiple of the
3919 * cipher block size. If the cipher is NULL for some
3920 * reason, we don't do this trick at all because we gain
3926 stringlen = (256 - deferred_len);
3927 stringlen += cscipher->blksize - 1;
3928 stringlen -= (stringlen % cscipher->blksize);
3931 * Temporarily disable actual compression,
3932 * so we can guarantee to get this string
3933 * exactly the length we want it. The
3934 * compression-disabling routine should
3935 * return an integer indicating how many
3936 * bytes we should adjust our string length
3939 stringlen -= cscomp->disable_compression();
3941 ssh2_pkt_init(SSH2_MSG_IGNORE);
3942 ssh2_pkt_addstring_start();
3943 for (i = 0; i < stringlen; i++) {
3944 char c = (char) random_byte();
3945 ssh2_pkt_addstring_data(&c, 1);
3949 ssh_pkt_defersend();
3950 logevent("Sent password");
3951 type = AUTH_TYPE_PASSWORD;
3952 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
3953 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
3954 ssh2_pkt_adduint32(num_prompts);
3955 ssh2_pkt_addstring(password);
3956 memset(password, 0, sizeof(password));
3958 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
3961 ("No supported authentication methods left to try!\r\n");
3963 ("No supported authentications offered. Disconnecting");
3964 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3965 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3967 ("No supported authentication methods available");
3968 ssh2_pkt_addstring("en"); /* language tag */
3970 ssh_state = SSH_STATE_CLOSED;
3974 } while (!we_are_in);
3977 * Now we're authenticated for the connection protocol. The
3978 * connection protocol will automatically have started at this
3979 * point; there's no need to send SERVICE_REQUEST.
3983 * So now create a channel with a session in it.
3985 ssh_channels = newtree234(ssh_channelcmp);
3986 mainchan = smalloc(sizeof(struct ssh_channel));
3987 mainchan->localid = alloc_channel_id();
3988 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3989 ssh2_pkt_addstring("session");
3990 ssh2_pkt_adduint32(mainchan->localid);
3991 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3992 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3994 crWaitUntilV(ispkt);
3995 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
3996 bombout(("Server refused to open a session"));
3998 /* FIXME: error data comes back in FAILURE packet */
4000 if (ssh2_pkt_getuint32() != mainchan->localid) {
4001 bombout(("Server's channel confirmation cited wrong channel"));
4004 mainchan->remoteid = ssh2_pkt_getuint32();
4005 mainchan->type = CHAN_MAINSESSION;
4006 mainchan->closes = 0;
4007 mainchan->v2.remwindow = ssh2_pkt_getuint32();
4008 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
4009 mainchan->v2.outbuffer = NULL;
4010 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
4011 add234(ssh_channels, mainchan);
4012 logevent("Opened channel for session");
4015 * Potentially enable X11 forwarding.
4017 if (cfg.x11_forward) {
4018 char proto[20], data[64];
4019 logevent("Requesting X11 forwarding");
4020 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4021 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4022 ssh2_pkt_adduint32(mainchan->remoteid);
4023 ssh2_pkt_addstring("x11-req");
4024 ssh2_pkt_addbool(1); /* want reply */
4025 ssh2_pkt_addbool(0); /* many connections */
4026 ssh2_pkt_addstring(proto);
4027 ssh2_pkt_addstring(data);
4028 ssh2_pkt_adduint32(0); /* screen number */
4032 crWaitUntilV(ispkt);
4033 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4034 unsigned i = ssh2_pkt_getuint32();
4035 struct ssh_channel *c;
4036 c = find234(ssh_channels, &i, ssh_channelfind);
4038 continue; /* nonexistent channel */
4039 c->v2.remwindow += ssh2_pkt_getuint32();
4041 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4043 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4044 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4045 bombout(("Server got confused by X11 forwarding request"));
4048 logevent("X11 forwarding refused");
4050 logevent("X11 forwarding enabled");
4051 ssh_X11_fwd_enabled = TRUE;
4056 * Potentially enable agent forwarding.
4058 if (cfg.agentfwd && agent_exists()) {
4059 logevent("Requesting OpenSSH-style agent forwarding");
4060 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4061 ssh2_pkt_adduint32(mainchan->remoteid);
4062 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4063 ssh2_pkt_addbool(1); /* want reply */
4067 crWaitUntilV(ispkt);
4068 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4069 unsigned i = ssh2_pkt_getuint32();
4070 struct ssh_channel *c;
4071 c = find234(ssh_channels, &i, ssh_channelfind);
4073 continue; /* nonexistent channel */
4074 c->v2.remwindow += ssh2_pkt_getuint32();
4076 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4078 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4079 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4081 ("Server got confused by agent forwarding request"));
4084 logevent("Agent forwarding refused");
4086 logevent("Agent forwarding enabled");
4087 ssh_agentfwd_enabled = TRUE;
4092 * Now allocate a pty for the session.
4095 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4096 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4097 ssh2_pkt_addstring("pty-req");
4098 ssh2_pkt_addbool(1); /* want reply */
4099 ssh2_pkt_addstring(cfg.termtype);
4100 ssh2_pkt_adduint32(cols);
4101 ssh2_pkt_adduint32(rows);
4102 ssh2_pkt_adduint32(0); /* pixel width */
4103 ssh2_pkt_adduint32(0); /* pixel height */
4104 ssh2_pkt_addstring_start();
4105 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4107 ssh_state = SSH_STATE_INTERMED;
4110 crWaitUntilV(ispkt);
4111 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4112 unsigned i = ssh2_pkt_getuint32();
4113 struct ssh_channel *c;
4114 c = find234(ssh_channels, &i, ssh_channelfind);
4116 continue; /* nonexistent channel */
4117 c->v2.remwindow += ssh2_pkt_getuint32();
4119 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4121 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4122 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4123 bombout(("Server got confused by pty request"));
4126 c_write_str("Server refused to allocate pty\r\n");
4127 ssh_editing = ssh_echoing = 1;
4129 logevent("Allocated pty");
4132 ssh_editing = ssh_echoing = 1;
4136 * Start a shell or a remote command.
4138 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4139 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4140 if (cfg.ssh_subsys) {
4141 ssh2_pkt_addstring("subsystem");
4142 ssh2_pkt_addbool(1); /* want reply */
4143 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
4144 } else if (*cfg.remote_cmd_ptr) {
4145 ssh2_pkt_addstring("exec");
4146 ssh2_pkt_addbool(1); /* want reply */
4147 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
4149 ssh2_pkt_addstring("shell");
4150 ssh2_pkt_addbool(1); /* want reply */
4154 crWaitUntilV(ispkt);
4155 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4156 unsigned i = ssh2_pkt_getuint32();
4157 struct ssh_channel *c;
4158 c = find234(ssh_channels, &i, ssh_channelfind);
4160 continue; /* nonexistent channel */
4161 c->v2.remwindow += ssh2_pkt_getuint32();
4163 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4164 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4165 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4166 bombout(("Server got confused by shell/command request"));
4169 bombout(("Server refused to start a shell/command"));
4172 logevent("Started a shell/command");
4175 ssh_state = SSH_STATE_SESSION;
4179 ssh_special(TS_EOF);
4184 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
4187 static int try_send;
4191 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
4192 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4195 unsigned i = ssh2_pkt_getuint32();
4196 struct ssh_channel *c;
4197 c = find234(ssh_channels, &i, ssh_channelfind);
4199 continue; /* nonexistent channel */
4200 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4201 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4202 continue; /* extended but not stderr */
4203 ssh2_pkt_getstring(&data, &length);
4206 case CHAN_MAINSESSION:
4207 from_backend(pktin.type ==
4208 SSH2_MSG_CHANNEL_EXTENDED_DATA, data,
4212 x11_send(c->u.x11.s, data, length);
4215 pfd_send(c->u.pfd.s, data, length);
4218 while (length > 0) {
4219 if (c->u.a.lensofar < 4) {
4220 int l = min(4 - c->u.a.lensofar, length);
4221 memcpy(c->u.a.msglen + c->u.a.lensofar,
4225 c->u.a.lensofar += l;
4227 if (c->u.a.lensofar == 4) {
4229 4 + GET_32BIT(c->u.a.msglen);
4230 c->u.a.message = smalloc(c->u.a.totallen);
4231 memcpy(c->u.a.message, c->u.a.msglen, 4);
4233 if (c->u.a.lensofar >= 4 && length > 0) {
4235 min(c->u.a.totallen - c->u.a.lensofar,
4237 memcpy(c->u.a.message + c->u.a.lensofar,
4241 c->u.a.lensofar += l;
4243 if (c->u.a.lensofar == c->u.a.totallen) {
4244 void *reply, *sentreply;
4246 agent_query(c->u.a.message,
4247 c->u.a.totallen, &reply,
4252 /* Fake SSH_AGENT_FAILURE. */
4253 sentreply = "\0\0\0\1\5";
4256 ssh2_add_channel_data(c, sentreply,
4261 sfree(c->u.a.message);
4262 c->u.a.lensofar = 0;
4268 * Enlarge the window again at the remote
4269 * side, just in case it ever runs down and
4270 * they fail to send us any more data.
4272 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4273 ssh2_pkt_adduint32(c->remoteid);
4274 ssh2_pkt_adduint32(length);
4277 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4278 ssh_state = SSH_STATE_CLOSED;
4279 logevent("Received disconnect message");
4281 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
4282 continue; /* exit status et al; ignore (FIXME?) */
4283 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4284 unsigned i = ssh2_pkt_getuint32();
4285 struct ssh_channel *c;
4287 c = find234(ssh_channels, &i, ssh_channelfind);
4289 continue; /* nonexistent channel */
4291 if (c->type == CHAN_X11) {
4293 * Remote EOF on an X11 channel means we should
4294 * wrap up and close the channel ourselves.
4296 x11_close(c->u.x11.s);
4298 } else if (c->type == CHAN_AGENT) {
4300 } else if (c->type == CHAN_SOCKDATA) {
4301 pfd_close(c->u.pfd.s);
4304 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4305 unsigned i = ssh2_pkt_getuint32();
4306 struct ssh_channel *c;
4308 c = find234(ssh_channels, &i, ssh_channelfind);
4310 continue; /* nonexistent channel */
4311 if (c->closes == 0) {
4312 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4313 ssh2_pkt_adduint32(c->remoteid);
4316 /* Do pre-close processing on the channel. */
4318 case CHAN_MAINSESSION:
4319 break; /* nothing to see here, move along */
4327 del234(ssh_channels, c);
4328 sfree(c->v2.outbuffer);
4332 * See if that was the last channel left open.
4334 if (count234(ssh_channels) == 0) {
4335 logevent("All channels closed. Disconnecting");
4336 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4337 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4338 ssh2_pkt_addstring("All open channels closed");
4339 ssh2_pkt_addstring("en"); /* language tag */
4341 ssh_state = SSH_STATE_CLOSED;
4344 continue; /* remote sends close; ignore (FIXME) */
4345 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4346 unsigned i = ssh2_pkt_getuint32();
4347 struct ssh_channel *c;
4348 c = find234(ssh_channels, &i, ssh_channelfind);
4350 continue; /* nonexistent channel */
4351 c->v2.remwindow += ssh2_pkt_getuint32();
4353 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
4357 struct ssh_channel *c;
4358 ssh2_pkt_getstring(&type, &typelen);
4359 c = smalloc(sizeof(struct ssh_channel));
4361 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4362 if (!ssh_X11_fwd_enabled)
4363 error = "X11 forwarding is not enabled";
4364 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4366 error = "Unable to open an X11 connection";
4370 } else if (typelen == 22 &&
4371 !memcmp(type, "auth-agent@openssh.com", 3)) {
4372 if (!ssh_agentfwd_enabled)
4373 error = "Agent forwarding is not enabled";
4375 c->type = CHAN_AGENT; /* identify channel type */
4376 c->u.a.lensofar = 0;
4379 error = "Unsupported channel type requested";
4382 c->remoteid = ssh2_pkt_getuint32();
4384 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4385 ssh2_pkt_adduint32(c->remoteid);
4386 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4387 ssh2_pkt_addstring(error);
4388 ssh2_pkt_addstring("en"); /* language tag */
4392 c->localid = alloc_channel_id();
4394 c->v2.remwindow = ssh2_pkt_getuint32();
4395 c->v2.remmaxpkt = ssh2_pkt_getuint32();
4396 c->v2.outbuffer = NULL;
4397 c->v2.outbuflen = c->v2.outbufsize = 0;
4398 add234(ssh_channels, c);
4399 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4400 ssh2_pkt_adduint32(c->remoteid);
4401 ssh2_pkt_adduint32(c->localid);
4402 ssh2_pkt_adduint32(0x8000UL); /* our window size */
4403 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4407 bombout(("Strange packet received: type %d", pktin.type));
4412 * We have spare data. Add it to the channel buffer.
4414 ssh2_add_channel_data(mainchan, in, inlen);
4419 struct ssh_channel *c;
4421 * Try to send data on all channels if we can.
4423 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
4432 * Handle the top-level SSH2 protocol.
4434 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4436 if (do_ssh2_transport(in, inlen, ispkt) == 0)
4438 do_ssh2_authconn(in, inlen, ispkt);
4442 * Called to set up the connection.
4444 * Returns an error message, or NULL on success.
4446 static char *ssh_init(char *host, int port, char **realhost)
4451 if (crypto_startup() == 0)
4452 return "Microsoft high encryption pack not installed!";
4459 p = connect_to_host(host, port, realhost);
4467 * Called to send data down the Telnet connection.
4469 static void ssh_send(char *buf, int len)
4471 if (s == NULL || ssh_protocol == NULL)
4474 ssh_protocol(buf, len, 0);
4478 * Called to set the size of the window from SSH's POV.
4480 static void ssh_size(void)
4482 switch (ssh_state) {
4483 case SSH_STATE_BEFORE_SIZE:
4484 case SSH_STATE_PREPACKET:
4485 case SSH_STATE_CLOSED:
4486 break; /* do nothing */
4487 case SSH_STATE_INTERMED:
4488 size_needed = TRUE; /* buffer for later */
4490 case SSH_STATE_SESSION:
4492 if (ssh_version == 1) {
4493 send_packet(SSH1_CMSG_WINDOW_SIZE,
4494 PKT_INT, rows, PKT_INT, cols,
4495 PKT_INT, 0, PKT_INT, 0, PKT_END);
4497 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4498 ssh2_pkt_adduint32(mainchan->remoteid);
4499 ssh2_pkt_addstring("window-change");
4500 ssh2_pkt_addbool(0);
4501 ssh2_pkt_adduint32(cols);
4502 ssh2_pkt_adduint32(rows);
4503 ssh2_pkt_adduint32(0);
4504 ssh2_pkt_adduint32(0);
4513 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4514 * can send an EOF and collect resulting output (e.g. `plink
4517 static void ssh_special(Telnet_Special code)
4519 if (code == TS_EOF) {
4520 if (ssh_state != SSH_STATE_SESSION) {
4522 * Buffer the EOF in case we are pre-SESSION, so we can
4523 * send it as soon as we reach SESSION.
4529 if (ssh_version == 1) {
4530 send_packet(SSH1_CMSG_EOF, PKT_END);
4532 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4533 ssh2_pkt_adduint32(mainchan->remoteid);
4536 logevent("Sent EOF message");
4537 } else if (code == TS_PING) {
4538 if (ssh_state == SSH_STATE_CLOSED
4539 || ssh_state == SSH_STATE_PREPACKET) return;
4540 if (ssh_version == 1) {
4541 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
4543 ssh2_pkt_init(SSH2_MSG_IGNORE);
4544 ssh2_pkt_addstring_start();
4552 void *new_sock_channel(Socket s)
4554 struct ssh_channel *c;
4555 c = smalloc(sizeof(struct ssh_channel));
4558 c->remoteid = GET_32BIT(pktin.body);
4559 c->localid = alloc_channel_id();
4561 c->type = CHAN_SOCKDATA; /* identify channel type */
4563 add234(ssh_channels, c);
4568 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
4570 struct ssh_channel *c = (struct ssh_channel *)channel;
4573 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
4576 send_packet(SSH1_MSG_PORT_OPEN,
4577 PKT_INT, c->localid,
4585 static Socket ssh_socket(void)
4590 static int ssh_sendok(void)
4595 static int ssh_ldisc(int option)
4597 if (option == LD_ECHO)
4599 if (option == LD_EDIT)
4604 Backend ssh_backend = {