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
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
165 #define GET_32BIT(cp) \
166 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
167 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
168 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
169 ((unsigned long)(unsigned char)(cp)[3]))
171 #define PUT_32BIT(cp, value) { \
172 (cp)[0] = (unsigned char)((value) >> 24); \
173 (cp)[1] = (unsigned char)((value) >> 16); \
174 (cp)[2] = (unsigned char)((value) >> 8); \
175 (cp)[3] = (unsigned char)(value); }
177 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
179 /* Coroutine mechanics for the sillier bits of the code */
180 #define crBegin1 static int crLine = 0;
181 #define crBegin2 switch(crLine) { case 0:;
182 #define crBegin crBegin1; crBegin2;
183 #define crFinish(z) } crLine = 0; return (z)
184 #define crFinishV } crLine = 0; return
185 #define crReturn(z) \
187 crLine=__LINE__; return (z); case __LINE__:;\
191 crLine=__LINE__; return; case __LINE__:;\
193 #define crStop(z) do{ crLine = 0; return (z); }while(0)
194 #define crStopV do{ crLine = 0; return; }while(0)
195 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
196 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
198 extern char *x11_init(Socket *, char *, void *);
199 extern void x11_close(Socket);
200 extern int x11_send(Socket, char *, int);
201 extern void x11_invent_auth(char *, int, char *, int);
202 extern void x11_unthrottle(Socket s);
203 extern void x11_override_throttle(Socket s, int enable);
205 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
206 extern char *pfd_addforward(char *desthost, int destport, int port);
207 extern void pfd_close(Socket s);
208 extern int pfd_send(Socket s, char *data, int len);
209 extern void pfd_confirm(Socket s);
210 extern void pfd_unthrottle(Socket s);
211 extern void pfd_override_throttle(Socket s, int enable);
214 * Buffer management constants. There are several of these for
215 * various different purposes:
217 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
218 * on a local data stream before we throttle the whole SSH
219 * connection (in SSH1 only). Throttling the whole connection is
220 * pretty drastic so we set this high in the hope it won't
223 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
224 * on the SSH connection itself before we defensively throttle
225 * _all_ local data streams. This is pretty drastic too (though
226 * thankfully unlikely in SSH2 since the window mechanism should
227 * ensure that the server never has any need to throttle its end
228 * of the connection), so we set this high as well.
230 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
234 #define SSH1_BUFFER_LIMIT 32768
235 #define SSH_MAX_BACKLOG 32768
236 #define OUR_V2_WINSIZE 16384
239 * Ciphers for SSH2. We miss out single-DES because it isn't
240 * supported; also 3DES and Blowfish are both done differently from
241 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
242 * endianness and different-sized keys.)
244 const static struct ssh2_ciphers *ciphers[] = {
250 const static struct ssh_kex *kex_algs[] = {
251 &ssh_diffiehellman_gex,
255 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
257 static void nullmac_key(unsigned char *key)
260 static void nullmac_generate(unsigned char *blk, int len,
264 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
268 const static struct ssh_mac ssh_mac_none = {
269 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
271 const static struct ssh_mac *macs[] = {
272 &ssh_sha1, &ssh_md5, &ssh_mac_none
274 const static struct ssh_mac *buggymacs[] = {
275 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
278 static void ssh_comp_none_init(void)
281 static int ssh_comp_none_block(unsigned char *block, int len,
282 unsigned char **outblock, int *outlen)
286 static int ssh_comp_none_disable(void)
290 const static struct ssh_compress ssh_comp_none = {
292 ssh_comp_none_init, ssh_comp_none_block,
293 ssh_comp_none_init, ssh_comp_none_block,
294 ssh_comp_none_disable
296 extern const struct ssh_compress ssh_zlib;
297 const static struct ssh_compress *compressions[] = {
298 &ssh_zlib, &ssh_comp_none
301 enum { /* channel types */
306 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
310 * 2-3-4 tree storing channels.
313 unsigned remoteid, localid;
317 struct ssh1_data_channel {
320 struct ssh2_data_channel {
322 unsigned remwindow, remmaxpkt;
327 struct ssh_agent_channel {
328 unsigned char *message;
329 unsigned char msglen[4];
330 int lensofar, totallen;
332 struct ssh_x11_channel {
335 struct ssh_pfd_channel {
342 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
343 * 2 use this structure in different ways, reflecting SSH 2's
344 * altogether saner approach to port forwarding.
346 * In SSH 1, you arrange a remote forwarding by sending the server
347 * the remote port number, and the local destination host:port.
348 * When a connection comes in, the server sends you back that
349 * host:port pair, and you connect to it. This is a ready-made
350 * security hole if you're not on the ball: a malicious server
351 * could send you back _any_ host:port pair, so if you trustingly
352 * connect to the address it gives you then you've just opened the
353 * entire inside of your corporate network just by connecting
354 * through it to a dodgy SSH server. Hence, we must store a list of
355 * host:port pairs we _are_ trying to forward to, and reject a
356 * connection request from the server if it's not in the list.
358 * In SSH 2, each side of the connection minds its own business and
359 * doesn't send unnecessary information to the other. You arrange a
360 * remote forwarding by sending the server just the remote port
361 * number. When a connection comes in, the server tells you which
362 * of its ports was connected to; and _you_ have to remember what
363 * local host:port pair went with that port number.
365 * Hence: in SSH 1 this structure stores host:port pairs we intend
366 * to allow connections to, and is indexed by those host:port
367 * pairs. In SSH 2 it stores a mapping from source port to
368 * destination host:port pair, and is indexed by source port.
370 struct ssh_rportfwd {
371 unsigned sport, dport;
384 static SHA_State exhash, exhashbase;
386 static Socket s = NULL;
388 static unsigned char session_key[32];
389 static int ssh1_compressing;
390 static int ssh1_remote_protoflags;
391 static int ssh1_local_protoflags;
392 static int ssh_agentfwd_enabled;
393 static int ssh_X11_fwd_enabled;
394 static int ssh_remote_bugs;
395 static const struct ssh_cipher *cipher = NULL;
396 static const struct ssh2_cipher *cscipher = NULL;
397 static const struct ssh2_cipher *sccipher = NULL;
398 static const struct ssh_mac *csmac = NULL;
399 static const struct ssh_mac *scmac = NULL;
400 static const struct ssh_compress *cscomp = NULL;
401 static const struct ssh_compress *sccomp = NULL;
402 static const struct ssh_kex *kex = NULL;
403 static const struct ssh_signkey *hostkey = NULL;
404 static unsigned char ssh2_session_id[20];
405 int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
408 static char *savedhost;
409 static int savedport;
410 static int ssh_send_ok;
411 static int ssh_echoing, ssh_editing;
413 static tree234 *ssh_channels; /* indexed by local id */
414 static struct ssh_channel *mainchan; /* primary session channel */
416 static tree234 *ssh_rportfwds;
420 SSH_STATE_BEFORE_SIZE,
424 } ssh_state = SSH_STATE_PREPACKET;
426 static int size_needed = FALSE, eof_needed = FALSE;
428 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
429 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
430 static unsigned char *deferred_send_data = NULL;
431 static int deferred_len = 0, deferred_size = 0;
434 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
435 * that fails. This variable is the means by which scp.c can reach
436 * into the SSH code and find out which one it got.
438 int ssh_fallback_cmd = 0;
440 static int ssh_version;
441 static int ssh1_throttle_count;
442 static int ssh_overall_bufsize;
443 static int ssh_throttled_all;
444 static int ssh1_stdout_throttling;
445 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
446 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
447 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
448 static void ssh_size(void);
449 static void ssh_special(Telnet_Special);
450 static int ssh2_try_send(struct ssh_channel *c);
451 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
453 static void ssh_throttle_all(int enable, int bufsize);
454 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
455 static int (*s_rdpkt) (unsigned char **data, int *datalen);
456 static int ssh_sendbuffer(void);
458 static struct rdpkt1_state_tag {
459 long len, pad, biglen, to_read;
460 unsigned long realcrc, gotcrc;
466 static struct rdpkt2_state_tag {
467 long len, pad, payload, packetlen, maclen;
470 unsigned long incoming_sequence;
473 static int ssh_channelcmp(void *av, void *bv)
475 struct ssh_channel *a = (struct ssh_channel *) av;
476 struct ssh_channel *b = (struct ssh_channel *) bv;
477 if (a->localid < b->localid)
479 if (a->localid > b->localid)
483 static int ssh_channelfind(void *av, void *bv)
485 unsigned *a = (unsigned *) av;
486 struct ssh_channel *b = (struct ssh_channel *) bv;
494 static int ssh_rportcmp_ssh1(void *av, void *bv)
496 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
497 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
499 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
500 return i < 0 ? -1 : +1;
501 if (a->dport > b->dport)
503 if (a->dport < b->dport)
508 static int ssh_rportcmp_ssh2(void *av, void *bv)
510 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
511 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
513 if (a->sport > b->sport)
515 if (a->sport < b->sport)
520 static int alloc_channel_id(void)
522 const unsigned CHANNEL_NUMBER_OFFSET = 256;
523 unsigned low, high, mid;
525 struct ssh_channel *c;
528 * First-fit allocation of channel numbers: always pick the
529 * lowest unused one. To do this, binary-search using the
530 * counted B-tree to find the largest channel ID which is in a
531 * contiguous sequence from the beginning. (Precisely
532 * everything in that sequence must have ID equal to its tree
533 * index plus CHANNEL_NUMBER_OFFSET.)
535 tsize = count234(ssh_channels);
539 while (high - low > 1) {
540 mid = (high + low) / 2;
541 c = index234(ssh_channels, mid);
542 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
543 low = mid; /* this one is fine */
545 high = mid; /* this one is past it */
548 * Now low points to either -1, or the tree index of the
549 * largest ID in the initial sequence.
552 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
553 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
555 return low + 1 + CHANNEL_NUMBER_OFFSET;
558 static void c_write(char *buf, int len)
560 if ((flags & FLAG_STDERR)) {
562 for (i = 0; i < len; i++)
564 fputc(buf[i], stderr);
567 from_backend(1, buf, len);
570 static void c_write_untrusted(char *buf, int len)
573 for (i = 0; i < len; i++) {
576 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
581 static void c_write_str(char *buf)
583 c_write(buf, strlen(buf));
587 * Collect incoming data in the incoming packet buffer.
588 * Decipher and verify the packet when it is completely read.
589 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
590 * Update the *data and *datalen variables.
591 * Return the additional nr of bytes needed, or 0 when
592 * a complete packet is available.
594 static int ssh1_rdpkt(unsigned char **data, int *datalen)
596 struct rdpkt1_state_tag *st = &rdpkt1_state;
605 for (st->i = st->len = 0; st->i < 4; st->i++) {
606 while ((*datalen) == 0)
608 st->len = (st->len << 8) + **data;
609 (*data)++, (*datalen)--;
612 st->pad = 8 - (st->len % 8);
613 st->biglen = st->len + st->pad;
614 pktin.length = st->len - 5;
616 if (pktin.maxlen < st->biglen) {
617 pktin.maxlen = st->biglen;
618 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
619 srealloc(pktin.data, st->biglen + APIEXTRA));
621 fatalbox("Out of memory");
624 st->to_read = st->biglen;
626 while (st->to_read > 0) {
627 st->chunk = st->to_read;
628 while ((*datalen) == 0)
629 crReturn(st->to_read);
630 if (st->chunk > (*datalen))
631 st->chunk = (*datalen);
632 memcpy(st->p, *data, st->chunk);
634 *datalen -= st->chunk;
636 st->to_read -= st->chunk;
640 cipher->decrypt(pktin.data, st->biglen);
642 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
643 dmemdump(pktin.data, st->biglen);
646 st->realcrc = crc32(pktin.data, st->biglen - 4);
647 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
648 if (st->gotcrc != st->realcrc) {
649 bombout(("Incorrect CRC received on packet"));
653 pktin.body = pktin.data + st->pad + 1;
655 if (ssh1_compressing) {
656 unsigned char *decompblk;
659 debug(("Packet payload pre-decompression:\n"));
660 dmemdump(pktin.body - 1, pktin.length + 1);
662 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
663 &decompblk, &decomplen);
665 if (pktin.maxlen < st->pad + decomplen) {
666 pktin.maxlen = st->pad + decomplen;
667 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
668 pktin.body = pktin.data + st->pad + 1;
670 fatalbox("Out of memory");
673 memcpy(pktin.body - 1, decompblk, decomplen);
675 pktin.length = decomplen - 1;
677 debug(("Packet payload post-decompression:\n"));
678 dmemdump(pktin.body - 1, pktin.length + 1);
682 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
683 pktin.type == SSH1_SMSG_STDERR_DATA ||
684 pktin.type == SSH1_MSG_DEBUG ||
685 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
686 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
687 long strlen = GET_32BIT(pktin.body);
688 if (strlen + 4 != pktin.length) {
689 bombout(("Received data packet with bogus string length"));
694 pktin.type = pktin.body[-1];
696 if (pktin.type == SSH1_MSG_DEBUG) {
697 /* log debug message */
699 int strlen = GET_32BIT(pktin.body);
700 strcpy(buf, "Remote: ");
703 memcpy(buf + 8, pktin.body + 4, strlen);
704 buf[8 + strlen] = '\0';
707 } else if (pktin.type == SSH1_MSG_IGNORE) {
712 if (pktin.type == SSH1_MSG_DISCONNECT) {
713 /* log reason code in disconnect message */
715 unsigned msglen = GET_32BIT(pktin.body);
717 strcpy(buf, "Remote sent disconnect: ");
718 nowlen = strlen(buf);
719 if (msglen > sizeof(buf) - nowlen - 1)
720 msglen = sizeof(buf) - nowlen - 1;
721 memcpy(buf + nowlen, pktin.body + 4, msglen);
722 buf[nowlen + msglen] = '\0';
724 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
731 static int ssh2_rdpkt(unsigned char **data, int *datalen)
733 struct rdpkt2_state_tag *st = &rdpkt2_state;
741 st->cipherblk = sccipher->blksize;
744 if (st->cipherblk < 8)
747 if (pktin.maxlen < st->cipherblk) {
748 pktin.maxlen = st->cipherblk;
751 NULL ? smalloc(st->cipherblk +
752 APIEXTRA) : srealloc(pktin.data,
756 fatalbox("Out of memory");
760 * Acquire and decrypt the first block of the packet. This will
761 * contain the length and padding details.
763 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
764 while ((*datalen) == 0)
765 crReturn(st->cipherblk - st->i);
766 pktin.data[st->i] = *(*data)++;
771 sccipher->decrypt(pktin.data, st->cipherblk);
774 * Now get the length and padding figures.
776 st->len = GET_32BIT(pktin.data);
777 st->pad = pktin.data[4];
780 * This enables us to deduce the payload length.
782 st->payload = st->len - st->pad - 1;
784 pktin.length = st->payload + 5;
787 * So now we can work out the total packet length.
789 st->packetlen = st->len + 4;
790 st->maclen = scmac ? scmac->len : 0;
793 * Adjust memory allocation if packet is too big.
795 if (pktin.maxlen < st->packetlen + st->maclen) {
796 pktin.maxlen = st->packetlen + st->maclen;
799 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
804 fatalbox("Out of memory");
808 * Read and decrypt the remainder of the packet.
810 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
812 while ((*datalen) == 0)
813 crReturn(st->packetlen + st->maclen - st->i);
814 pktin.data[st->i] = *(*data)++;
817 /* Decrypt everything _except_ the MAC. */
819 sccipher->decrypt(pktin.data + st->cipherblk,
820 st->packetlen - st->cipherblk);
823 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
824 dmemdump(pktin.data, st->packetlen);
831 && !scmac->verify(pktin.data, st->len + 4,
832 st->incoming_sequence)) {
833 bombout(("Incorrect MAC received on packet"));
836 st->incoming_sequence++; /* whether or not we MACed */
839 * Decompress packet payload.
842 unsigned char *newpayload;
844 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
845 &newpayload, &newlen)) {
846 if (pktin.maxlen < newlen + 5) {
847 pktin.maxlen = newlen + 5;
850 NULL ? smalloc(pktin.maxlen +
851 APIEXTRA) : srealloc(pktin.data,
855 fatalbox("Out of memory");
857 pktin.length = 5 + newlen;
858 memcpy(pktin.data + 5, newpayload, newlen);
860 debug(("Post-decompression payload:\n"));
861 dmemdump(pktin.data + 5, newlen);
869 pktin.type = pktin.data[5];
871 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
872 goto next_packet; /* FIXME: print DEBUG message */
874 if (pktin.type == SSH2_MSG_DISCONNECT) {
875 /* log reason code in disconnect message */
877 int reason = GET_32BIT(pktin.data + 6);
878 unsigned msglen = GET_32BIT(pktin.data + 10);
880 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
881 sprintf(buf, "Received disconnect message (%s)",
882 ssh2_disconnect_reasons[reason]);
884 sprintf(buf, "Received disconnect message (unknown type %d)",
888 strcpy(buf, "Disconnection message text: ");
889 nowlen = strlen(buf);
890 if (msglen > sizeof(buf) - nowlen - 1)
891 msglen = sizeof(buf) - nowlen - 1;
892 memcpy(buf + nowlen, pktin.data + 14, msglen);
893 buf[nowlen + msglen] = '\0';
895 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
897 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
898 ssh2_disconnect_reasons[reason] : "unknown",
906 static void ssh1_pktout_size(int len)
910 len += 5; /* type and CRC */
914 pktout.length = len - 5;
915 if (pktout.maxlen < biglen) {
916 pktout.maxlen = biglen;
918 /* Allocate enough buffer space for extra block
919 * for MS CryptEncrypt() */
920 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
921 srealloc(pktout.data, biglen + 12));
923 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
924 srealloc(pktout.data, biglen + 4));
927 fatalbox("Out of memory");
929 pktout.body = pktout.data + 4 + pad + 1;
932 static void s_wrpkt_start(int type, int len)
934 ssh1_pktout_size(len);
938 static int s_wrpkt_prepare(void)
940 int pad, len, biglen, i;
943 pktout.body[-1] = pktout.type;
945 if (ssh1_compressing) {
946 unsigned char *compblk;
949 debug(("Packet payload pre-compression:\n"));
950 dmemdump(pktout.body - 1, pktout.length + 1);
952 zlib_compress_block(pktout.body - 1, pktout.length + 1,
954 ssh1_pktout_size(complen - 1);
955 memcpy(pktout.body - 1, compblk, complen);
959 len = pktout.length + 5; /* type and CRC */
963 for (i = 0; i < pad; i++)
964 pktout.data[i + 4] = random_byte();
965 crc = crc32(pktout.data + 4, biglen - 4);
966 PUT_32BIT(pktout.data + biglen, crc);
967 PUT_32BIT(pktout.data, len);
970 debug(("Sending packet len=%d\n", biglen + 4));
971 dmemdump(pktout.data, biglen + 4);
974 cipher->encrypt(pktout.data + 4, biglen);
979 static void s_wrpkt(void)
982 len = s_wrpkt_prepare();
983 backlog = sk_write(s, pktout.data, len);
984 if (backlog > SSH_MAX_BACKLOG)
985 ssh_throttle_all(1, backlog);
988 static void s_wrpkt_defer(void)
991 len = s_wrpkt_prepare();
992 if (deferred_len + len > deferred_size) {
993 deferred_size = deferred_len + len + 128;
994 deferred_send_data = srealloc(deferred_send_data, deferred_size);
996 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1001 * Construct a packet with the specified contents.
1003 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
1005 unsigned char *p, *argp, argchar;
1006 unsigned long argint;
1007 int pktlen, argtype, arglen;
1011 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1014 (void) va_arg(ap1, int);
1018 (void) va_arg(ap1, char);
1022 (void) va_arg(ap1, unsigned char *);
1023 arglen = va_arg(ap1, int);
1027 argp = va_arg(ap1, unsigned char *);
1028 arglen = strlen(argp);
1029 pktlen += 4 + arglen;
1032 bn = va_arg(ap1, Bignum);
1033 pktlen += ssh1_bignum_length(bn);
1040 s_wrpkt_start(pkttype, pktlen);
1043 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1046 argint = va_arg(ap2, int);
1047 PUT_32BIT(p, argint);
1051 argchar = va_arg(ap2, unsigned char);
1056 argp = va_arg(ap2, unsigned char *);
1057 arglen = va_arg(ap2, int);
1058 memcpy(p, argp, arglen);
1062 argp = va_arg(ap2, unsigned char *);
1063 arglen = strlen(argp);
1064 PUT_32BIT(p, arglen);
1065 memcpy(p + 4, argp, arglen);
1069 bn = va_arg(ap2, Bignum);
1070 p += ssh1_write_bignum(p, bn);
1076 static void send_packet(int pkttype, ...)
1079 va_start(ap1, pkttype);
1080 va_start(ap2, pkttype);
1081 construct_packet(pkttype, ap1, ap2);
1085 static void defer_packet(int pkttype, ...)
1088 va_start(ap1, pkttype);
1089 va_start(ap2, pkttype);
1090 construct_packet(pkttype, ap1, ap2);
1094 static int ssh_versioncmp(char *a, char *b)
1097 unsigned long av, bv;
1099 av = strtoul(a, &ae, 10);
1100 bv = strtoul(b, &be, 10);
1102 return (av < bv ? -1 : +1);
1107 av = strtoul(ae, &ae, 10);
1108 bv = strtoul(be, &be, 10);
1110 return (av < bv ? -1 : +1);
1116 * Utility routines for putting an SSH-protocol `string' and
1117 * `uint32' into a SHA state.
1120 static void sha_string(SHA_State * s, void *str, int len)
1122 unsigned char lenblk[4];
1123 PUT_32BIT(lenblk, len);
1124 SHA_Bytes(s, lenblk, 4);
1125 SHA_Bytes(s, str, len);
1128 static void sha_uint32(SHA_State * s, unsigned i)
1130 unsigned char intblk[4];
1131 PUT_32BIT(intblk, i);
1132 SHA_Bytes(s, intblk, 4);
1136 * SSH2 packet construction functions.
1138 static void ssh2_pkt_ensure(int length)
1140 if (pktout.maxlen < length) {
1141 pktout.maxlen = length + 256;
1144 NULL ? smalloc(pktout.maxlen +
1145 APIEXTRA) : srealloc(pktout.data,
1149 fatalbox("Out of memory");
1152 static void ssh2_pkt_adddata(void *data, int len)
1154 pktout.length += len;
1155 ssh2_pkt_ensure(pktout.length);
1156 memcpy(pktout.data + pktout.length - len, data, len);
1158 static void ssh2_pkt_addbyte(unsigned char byte)
1160 ssh2_pkt_adddata(&byte, 1);
1162 static void ssh2_pkt_init(int pkt_type)
1165 ssh2_pkt_addbyte((unsigned char) pkt_type);
1167 static void ssh2_pkt_addbool(unsigned char value)
1169 ssh2_pkt_adddata(&value, 1);
1171 static void ssh2_pkt_adduint32(unsigned long value)
1174 PUT_32BIT(x, value);
1175 ssh2_pkt_adddata(x, 4);
1177 static void ssh2_pkt_addstring_start(void)
1179 ssh2_pkt_adduint32(0);
1180 pktout.savedpos = pktout.length;
1182 static void ssh2_pkt_addstring_str(char *data)
1184 ssh2_pkt_adddata(data, strlen(data));
1185 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1186 pktout.length - pktout.savedpos);
1188 static void ssh2_pkt_addstring_data(char *data, int len)
1190 ssh2_pkt_adddata(data, len);
1191 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1192 pktout.length - pktout.savedpos);
1194 static void ssh2_pkt_addstring(char *data)
1196 ssh2_pkt_addstring_start();
1197 ssh2_pkt_addstring_str(data);
1199 static char *ssh2_mpint_fmt(Bignum b, int *len)
1202 int i, n = (bignum_bitcount(b) + 7) / 8;
1205 fatalbox("out of memory");
1207 for (i = 1; i <= n; i++)
1208 p[i] = bignum_byte(b, n - i);
1210 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1212 memmove(p, p + i, n + 1 - i);
1216 static void ssh2_pkt_addmp(Bignum b)
1220 p = ssh2_mpint_fmt(b, &len);
1221 ssh2_pkt_addstring_start();
1222 ssh2_pkt_addstring_data(p, len);
1227 * Construct an SSH2 final-form packet: compress it, encrypt it,
1228 * put the MAC on it. Final packet, ready to be sent, is stored in
1229 * pktout.data. Total length is returned.
1231 static int ssh2_pkt_construct(void)
1233 int cipherblk, maclen, padding, i;
1234 static unsigned long outgoing_sequence = 0;
1237 * Compress packet payload.
1240 unsigned char *newpayload;
1243 if (cscomp && cscomp != &ssh_comp_none) {
1244 debug(("Pre-compression payload:\n"));
1245 dmemdump(pktout.data + 5, pktout.length - 5);
1248 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1249 &newpayload, &newlen)) {
1251 ssh2_pkt_adddata(newpayload, newlen);
1257 * Add padding. At least four bytes, and must also bring total
1258 * length (minus MAC) up to a multiple of the block size.
1260 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1261 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1264 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1265 maclen = csmac ? csmac->len : 0;
1266 ssh2_pkt_ensure(pktout.length + padding + maclen);
1267 pktout.data[4] = padding;
1268 for (i = 0; i < padding; i++)
1269 pktout.data[pktout.length + i] = random_byte();
1270 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1272 csmac->generate(pktout.data, pktout.length + padding,
1274 outgoing_sequence++; /* whether or not we MACed */
1277 debug(("Sending packet len=%d\n", pktout.length + padding));
1278 dmemdump(pktout.data, pktout.length + padding);
1282 cscipher->encrypt(pktout.data, pktout.length + padding);
1284 /* Ready-to-send packet starts at pktout.data. We return length. */
1285 return pktout.length + padding + maclen;
1289 * Construct and send an SSH2 packet immediately.
1291 static void ssh2_pkt_send(void)
1295 len = ssh2_pkt_construct();
1296 backlog = sk_write(s, pktout.data, len);
1297 if (backlog > SSH_MAX_BACKLOG)
1298 ssh_throttle_all(1, backlog);
1302 * Construct an SSH2 packet and add it to a deferred data block.
1303 * Useful for sending multiple packets in a single sk_write() call,
1304 * to prevent a traffic-analysing listener from being able to work
1305 * out the length of any particular packet (such as the password
1308 * Note that because SSH2 sequence-numbers its packets, this can
1309 * NOT be used as an m4-style `defer' allowing packets to be
1310 * constructed in one order and sent in another.
1312 static void ssh2_pkt_defer(void)
1314 int len = ssh2_pkt_construct();
1315 if (deferred_len + len > deferred_size) {
1316 deferred_size = deferred_len + len + 128;
1317 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1319 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1320 deferred_len += len;
1324 * Send the whole deferred data block constructed by
1325 * ssh2_pkt_defer() or SSH1's defer_packet().
1327 static void ssh_pkt_defersend(void)
1330 backlog = sk_write(s, deferred_send_data, deferred_len);
1331 deferred_len = deferred_size = 0;
1332 sfree(deferred_send_data);
1333 deferred_send_data = NULL;
1334 if (backlog > SSH_MAX_BACKLOG)
1335 ssh_throttle_all(1, backlog);
1339 void bndebug(char *string, Bignum b)
1343 p = ssh2_mpint_fmt(b, &len);
1344 debug(("%s", string));
1345 for (i = 0; i < len; i++)
1346 debug((" %02x", p[i]));
1352 static void sha_mpint(SHA_State * s, Bignum b)
1356 p = ssh2_mpint_fmt(b, &len);
1357 sha_string(s, p, len);
1362 * SSH2 packet decode functions.
1364 static unsigned long ssh2_pkt_getuint32(void)
1366 unsigned long value;
1367 if (pktin.length - pktin.savedpos < 4)
1368 return 0; /* arrgh, no way to decline (FIXME?) */
1369 value = GET_32BIT(pktin.data + pktin.savedpos);
1370 pktin.savedpos += 4;
1373 static int ssh2_pkt_getbool(void)
1375 unsigned long value;
1376 if (pktin.length - pktin.savedpos < 1)
1377 return 0; /* arrgh, no way to decline (FIXME?) */
1378 value = pktin.data[pktin.savedpos] != 0;
1382 static void ssh2_pkt_getstring(char **p, int *length)
1385 if (pktin.length - pktin.savedpos < 4)
1387 *length = GET_32BIT(pktin.data + pktin.savedpos);
1388 pktin.savedpos += 4;
1389 if (pktin.length - pktin.savedpos < *length)
1391 *p = pktin.data + pktin.savedpos;
1392 pktin.savedpos += *length;
1394 static Bignum ssh2_pkt_getmp(void)
1400 ssh2_pkt_getstring(&p, &length);
1404 bombout(("internal error: Can't handle negative mpints"));
1407 b = bignum_from_bytes(p, length);
1412 * Examine the remote side's version string and compare it against
1413 * a list of known buggy implementations.
1415 static void ssh_detect_bugs(char *vstring)
1417 char *imp; /* pointer to implementation part */
1419 imp += strcspn(imp, "-");
1421 imp += strcspn(imp, "-");
1424 ssh_remote_bugs = 0;
1426 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1427 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1428 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
1430 * These versions don't support SSH1_MSG_IGNORE, so we have
1431 * to use a different defence against password length
1434 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1435 logevent("We believe remote version has SSH1 ignore bug");
1438 if (!strcmp(imp, "Cisco-1.25")) {
1440 * These versions need a plain password sent; they can't
1441 * handle having a null and a random length of data after
1444 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1445 logevent("We believe remote version needs a plain SSH1 password");
1448 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1449 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1450 !strncmp(imp, "2.1 ", 4)) {
1452 * These versions have the HMAC bug.
1454 ssh_remote_bugs |= BUG_SSH2_HMAC;
1455 logevent("We believe remote version has SSH2 HMAC bug");
1459 static int do_ssh_init(unsigned char c)
1462 static char version[10];
1463 static char *vstring;
1464 static int vstrsize;
1470 /* Search for the string "SSH-" in the input. */
1473 static const int transS[] = { 1, 2, 2, 1 };
1474 static const int transH[] = { 0, 0, 3, 0 };
1475 static const int transminus[] = { 0, 0, 0, -1 };
1486 crReturn(1); /* get another character */
1490 vstring = smalloc(vstrsize);
1491 strcpy(vstring, "SSH-");
1495 crReturn(1); /* get another char */
1496 if (vslen >= vstrsize - 1) {
1498 vstring = srealloc(vstring, vstrsize);
1500 vstring[vslen++] = c;
1505 } else if (i < sizeof(version) - 1)
1507 } else if (c == '\n')
1511 ssh_agentfwd_enabled = FALSE;
1512 rdpkt2_state.incoming_sequence = 0;
1515 vlog = smalloc(20 + vslen);
1516 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
1517 sprintf(vlog, "Server version: %s", vstring);
1519 ssh_detect_bugs(vstring);
1523 * Server version "1.99" means we can choose whether we use v1
1524 * or v2 protocol. Choice is based on cfg.sshprot.
1526 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1528 * This is a v2 server. Begin v2 protocol.
1530 char verstring[80], vlog[100];
1531 sprintf(verstring, "SSH-2.0-%s", sshver);
1532 SHA_Init(&exhashbase);
1534 * Hash our version string and their version string.
1536 sha_string(&exhashbase, verstring, strlen(verstring));
1537 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1538 sprintf(vlog, "We claim version: %s", verstring);
1540 strcat(verstring, "\n");
1541 logevent("Using SSH protocol version 2");
1542 sk_write(s, verstring, strlen(verstring));
1543 ssh_protocol = ssh2_protocol;
1545 s_rdpkt = ssh2_rdpkt;
1548 * This is a v1 server. Begin v1 protocol.
1550 char verstring[80], vlog[100];
1551 sprintf(verstring, "SSH-%s-%s",
1552 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1554 sprintf(vlog, "We claim version: %s", verstring);
1556 strcat(verstring, "\n");
1557 logevent("Using SSH protocol version 1");
1558 sk_write(s, verstring, strlen(verstring));
1559 ssh_protocol = ssh1_protocol;
1561 s_rdpkt = ssh1_rdpkt;
1563 ssh_state = SSH_STATE_BEFORE_SIZE;
1570 static void ssh_gotdata(unsigned char *data, int datalen)
1575 * To begin with, feed the characters one by one to the
1576 * protocol initialisation / selection function do_ssh_init().
1577 * When that returns 0, we're done with the initial greeting
1578 * exchange and can move on to packet discipline.
1583 crReturnV; /* more data please */
1584 ret = do_ssh_init(*data);
1592 * We emerge from that loop when the initial negotiation is
1593 * over and we have selected an s_rdpkt function. Now pass
1594 * everything to s_rdpkt, and then pass the resulting packets
1595 * to the proper protocol handler.
1600 while (datalen > 0) {
1601 if (s_rdpkt(&data, &datalen) == 0) {
1602 if (ssh_state == SSH_STATE_CLOSED) {
1605 ssh_protocol(NULL, 0, 1);
1606 if (ssh_state == SSH_STATE_CLOSED) {
1616 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1619 ssh_state = SSH_STATE_CLOSED;
1625 /* A socket error has occurred. */
1626 connection_fatal(error_msg);
1628 /* Otherwise, the remote side closed the connection normally. */
1633 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1635 ssh_gotdata(data, len);
1636 if (ssh_state == SSH_STATE_CLOSED) {
1646 static void ssh_sent(Plug plug, int bufsize)
1649 * If the send backlog on the SSH socket itself clears, we
1650 * should unthrottle the whole world if it was throttled.
1652 if (bufsize < SSH_MAX_BACKLOG)
1653 ssh_throttle_all(0, bufsize);
1657 * Connect to specified host and port.
1658 * Returns an error message, or NULL on success.
1659 * Also places the canonical host name into `realhost'. It must be
1660 * freed by the caller.
1662 static char *connect_to_host(char *host, int port, char **realhost)
1664 static struct plug_function_table fn_table = {
1669 }, *fn_table_ptr = &fn_table;
1678 savedhost = smalloc(1 + strlen(host));
1680 fatalbox("Out of memory");
1681 strcpy(savedhost, host);
1684 port = 22; /* default ssh port */
1699 sprintf(buf, "Looking up host \"%.170s\"", host);
1702 addr = sk_namelookup(host, realhost);
1703 if ((err = sk_addr_error(addr)))
1707 *realhost = strdup(FWhost);
1714 char buf[200], addrbuf[100];
1715 sk_getaddr(addr, addrbuf, 100);
1716 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1719 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1720 if ((err = sk_socket_error(s)))
1724 sk_write(s, "connect ", 8);
1725 sk_write(s, FWhost, strlen(FWhost));
1728 sprintf(buf, " %d\n", FWport);
1729 sk_write(s, buf, strlen(buf));
1737 * Throttle or unthrottle the SSH connection.
1739 static void ssh1_throttle(int adjust)
1741 int old_count = ssh1_throttle_count;
1742 ssh1_throttle_count += adjust;
1743 assert(ssh1_throttle_count >= 0);
1744 if (ssh1_throttle_count && !old_count) {
1745 sk_set_frozen(s, 1);
1746 } else if (!ssh1_throttle_count && old_count) {
1747 sk_set_frozen(s, 0);
1752 * Throttle or unthrottle _all_ local data streams (for when sends
1753 * on the SSH connection itself back up).
1755 static void ssh_throttle_all(int enable, int bufsize)
1758 struct ssh_channel *c;
1760 if (enable == ssh_throttled_all)
1762 ssh_throttled_all = enable;
1763 ssh_overall_bufsize = bufsize;
1766 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
1768 case CHAN_MAINSESSION:
1770 * This is treated separately, outside the switch.
1774 x11_override_throttle(c->u.x11.s, enable);
1777 /* Agent channels require no buffer management. */
1780 pfd_override_throttle(c->u.x11.s, enable);
1787 * Handle the key exchange and user authentication phases.
1789 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1793 static unsigned char *rsabuf, *keystr1, *keystr2;
1794 unsigned char cookie[8];
1795 struct RSAKey servkey, hostkey;
1796 struct MD5Context md5c;
1797 static unsigned long supported_ciphers_mask, supported_auths_mask;
1798 static int tried_publickey;
1799 static int tis_auth_refused, ccard_auth_refused;
1800 static unsigned char session_id[16];
1801 static int cipher_type;
1802 static char username[100];
1809 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1810 bombout(("Public key packet not received"));
1814 logevent("Received public keys");
1816 memcpy(cookie, pktin.body, 8);
1818 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1819 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1822 * Log the host key fingerprint.
1826 logevent("Host key fingerprint is:");
1827 strcpy(logmsg, " ");
1828 hostkey.comment = NULL;
1829 rsa_fingerprint(logmsg + strlen(logmsg),
1830 sizeof(logmsg) - strlen(logmsg), &hostkey);
1834 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1835 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1836 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1838 ssh1_local_protoflags =
1839 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1840 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1843 MD5Update(&md5c, keystr2, hostkey.bytes);
1844 MD5Update(&md5c, keystr1, servkey.bytes);
1845 MD5Update(&md5c, pktin.body, 8);
1846 MD5Final(session_id, &md5c);
1848 for (i = 0; i < 32; i++)
1849 session_key[i] = random_byte();
1851 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1853 rsabuf = smalloc(len);
1855 fatalbox("Out of memory");
1858 * Verify the host key.
1862 * First format the key into a string.
1864 int len = rsastr_len(&hostkey);
1865 char fingerprint[100];
1866 char *keystr = smalloc(len);
1868 fatalbox("Out of memory");
1869 rsastr_fmt(keystr, &hostkey);
1870 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1871 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1876 for (i = 0; i < 32; i++) {
1877 rsabuf[i] = session_key[i];
1879 rsabuf[i] ^= session_id[i];
1882 if (hostkey.bytes > servkey.bytes) {
1883 rsaencrypt(rsabuf, 32, &servkey);
1884 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1886 rsaencrypt(rsabuf, 32, &hostkey);
1887 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1890 logevent("Encrypted session key");
1893 int cipher_chosen = 0, warn = 0;
1894 char *cipher_string = NULL;
1895 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
1896 int next_cipher = cfg.ssh_cipherlist[i];
1897 if (next_cipher == CIPHER_WARN) {
1898 /* If/when we choose a cipher, warn about it */
1900 } else if (next_cipher == CIPHER_AES) {
1901 /* XXX Probably don't need to mention this. */
1902 logevent("AES not supported in SSH1, skipping");
1904 switch (next_cipher) {
1905 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
1906 cipher_string = "3DES"; break;
1907 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
1908 cipher_string = "Blowfish"; break;
1909 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
1910 cipher_string = "single-DES"; break;
1912 if (supported_ciphers_mask & (1 << cipher_type))
1916 if (!cipher_chosen) {
1917 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
1918 bombout(("Server violates SSH 1 protocol by not "
1919 "supporting 3DES encryption"));
1921 /* shouldn't happen */
1922 bombout(("No supported ciphers found"));
1926 /* Warn about chosen cipher if necessary. */
1928 askcipher(cipher_string, 0);
1931 switch (cipher_type) {
1932 case SSH_CIPHER_3DES:
1933 logevent("Using 3DES encryption");
1935 case SSH_CIPHER_DES:
1936 logevent("Using single-DES encryption");
1938 case SSH_CIPHER_BLOWFISH:
1939 logevent("Using Blowfish encryption");
1943 send_packet(SSH1_CMSG_SESSION_KEY,
1944 PKT_CHAR, cipher_type,
1945 PKT_DATA, cookie, 8,
1946 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1947 PKT_DATA, rsabuf, len,
1948 PKT_INT, ssh1_local_protoflags, PKT_END);
1950 logevent("Trying to enable encryption...");
1954 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1955 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
1956 cipher->sesskey(session_key);
1960 if (pktin.type != SSH1_SMSG_SUCCESS) {
1961 bombout(("Encryption not successfully enabled"));
1965 logevent("Successfully started encryption");
1971 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1973 if (!ssh_get_line("login as: ",
1974 username, sizeof(username), FALSE)) {
1976 * get_line failed to get a username.
1979 logevent("No username provided. Abandoning session.");
1980 ssh_state = SSH_STATE_CLOSED;
1984 c_write_str("login as: ");
1987 crWaitUntil(!ispkt);
1989 switch (c = *in++) {
1998 c_write_str("\b \b");
2005 c_write_str("\b \b");
2015 if (((c >= ' ' && c <= '~') ||
2016 ((unsigned char) c >= 160))
2017 && pos < sizeof(username)-1) {
2018 username[pos++] = c;
2024 c_write_str("\r\n");
2025 username[strcspn(username, "\n\r")] = '\0';
2028 strncpy(username, cfg.username, 99);
2029 username[99] = '\0';
2032 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2034 char userlog[22 + sizeof(username)];
2035 sprintf(userlog, "Sent username \"%s\"", username);
2037 if (flags & FLAG_INTERACTIVE &&
2038 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2039 strcat(userlog, "\r\n");
2040 c_write_str(userlog);
2047 tried_publickey = 0;
2048 tis_auth_refused = ccard_auth_refused = 0;
2050 while (pktin.type == SSH1_SMSG_FAILURE) {
2051 static char password[100];
2052 static char prompt[200];
2055 static int pwpkt_type;
2056 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2058 if (agent_exists()) {
2060 * Attempt RSA authentication using Pageant.
2062 static unsigned char request[5], *response, *p;
2063 static int responselen;
2064 static int i, nkeys;
2065 static int authed = FALSE;
2068 logevent("Pageant is running. Requesting keys.");
2070 /* Request the keys held by the agent. */
2071 PUT_32BIT(request, 1);
2072 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2073 agent_query(request, 5, &r, &responselen);
2074 response = (unsigned char *) r;
2075 if (response && responselen >= 5 &&
2076 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2078 nkeys = GET_32BIT(p);
2082 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2085 for (i = 0; i < nkeys; i++) {
2086 static struct RSAKey key;
2087 static Bignum challenge;
2088 static char *commentp;
2089 static int commentlen;
2093 sprintf(buf, "Trying Pageant key #%d", i);
2097 p += ssh1_read_bignum(p, &key.exponent);
2098 p += ssh1_read_bignum(p, &key.modulus);
2099 commentlen = GET_32BIT(p);
2103 send_packet(SSH1_CMSG_AUTH_RSA,
2104 PKT_BIGNUM, key.modulus, PKT_END);
2106 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2107 logevent("Key refused");
2110 logevent("Received RSA challenge");
2111 ssh1_read_bignum(pktin.body, &challenge);
2113 char *agentreq, *q, *ret;
2116 len = 1 + 4; /* message type, bit count */
2117 len += ssh1_bignum_length(key.exponent);
2118 len += ssh1_bignum_length(key.modulus);
2119 len += ssh1_bignum_length(challenge);
2120 len += 16; /* session id */
2121 len += 4; /* response format */
2122 agentreq = smalloc(4 + len);
2123 PUT_32BIT(agentreq, len);
2125 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2126 PUT_32BIT(q, bignum_bitcount(key.modulus));
2128 q += ssh1_write_bignum(q, key.exponent);
2129 q += ssh1_write_bignum(q, key.modulus);
2130 q += ssh1_write_bignum(q, challenge);
2131 memcpy(q, session_id, 16);
2133 PUT_32BIT(q, 1); /* response format */
2134 agent_query(agentreq, len + 4, &vret, &retlen);
2138 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2139 logevent("Sending Pageant's response");
2140 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2141 PKT_DATA, ret + 5, 16,
2145 if (pktin.type == SSH1_SMSG_SUCCESS) {
2147 ("Pageant's response accepted");
2148 if (flags & FLAG_VERBOSE) {
2150 ("Authenticated using RSA key \"");
2151 c_write(commentp, commentlen);
2152 c_write_str("\" from agent\r\n");
2157 ("Pageant's response not accepted");
2160 ("Pageant failed to answer challenge");
2164 logevent("No reply received from Pageant");
2167 freebn(key.exponent);
2168 freebn(key.modulus);
2177 if (*cfg.keyfile && !tried_publickey)
2178 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2180 if (cfg.try_tis_auth &&
2181 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2182 !tis_auth_refused) {
2183 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2184 logevent("Requested TIS authentication");
2185 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2187 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2188 logevent("TIS authentication declined");
2189 if (flags & FLAG_INTERACTIVE)
2190 c_write_str("TIS authentication refused.\r\n");
2191 tis_auth_refused = 1;
2194 int challengelen = ((pktin.body[0] << 24) |
2195 (pktin.body[1] << 16) |
2196 (pktin.body[2] << 8) |
2198 logevent("Received TIS challenge");
2199 if (challengelen > sizeof(prompt) - 1)
2200 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2201 memcpy(prompt, pktin.body + 4, challengelen);
2202 /* Prompt heuristic comes from OpenSSH */
2203 strncpy(prompt + challengelen,
2204 memchr(prompt, '\n', challengelen) ?
2205 "": "\r\nResponse: ",
2206 (sizeof prompt) - challengelen);
2207 prompt[(sizeof prompt) - 1] = '\0';
2210 if (cfg.try_tis_auth &&
2211 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2212 !ccard_auth_refused) {
2213 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2214 logevent("Requested CryptoCard authentication");
2215 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2217 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2218 logevent("CryptoCard authentication declined");
2219 c_write_str("CryptoCard authentication refused.\r\n");
2220 ccard_auth_refused = 1;
2223 int challengelen = ((pktin.body[0] << 24) |
2224 (pktin.body[1] << 16) |
2225 (pktin.body[2] << 8) |
2227 logevent("Received CryptoCard challenge");
2228 if (challengelen > sizeof(prompt) - 1)
2229 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2230 memcpy(prompt, pktin.body + 4, challengelen);
2231 strncpy(prompt + challengelen,
2232 memchr(prompt, '\n', challengelen) ?
2233 "" : "\r\nResponse: ",
2234 sizeof(prompt) - challengelen);
2235 prompt[sizeof(prompt) - 1] = '\0';
2238 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2239 sprintf(prompt, "%.90s@%.90s's password: ",
2240 username, savedhost);
2242 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2243 char *comment = NULL;
2244 if (flags & FLAG_VERBOSE)
2245 c_write_str("Trying public key authentication.\r\n");
2246 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2247 if (flags & FLAG_VERBOSE)
2248 c_write_str("No passphrase required.\r\n");
2251 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2256 * Show password prompt, having first obtained it via a TIS
2257 * or CryptoCard exchange if we're doing TIS or CryptoCard
2261 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2263 * get_line failed to get a password (for example
2264 * because one was supplied on the command line
2265 * which has already failed to work). Terminate.
2267 send_packet(SSH1_MSG_DISCONNECT,
2268 PKT_STR, "No more passwords available to try",
2270 connection_fatal("Unable to authenticate");
2271 ssh_state = SSH_STATE_CLOSED;
2275 /* Prompt may have come from server. We've munged it a bit, so
2276 * we know it to be zero-terminated at least once. */
2277 c_write_untrusted(prompt, strlen(prompt));
2281 crWaitUntil(!ispkt);
2283 switch (c = *in++) {
2304 if (pos < sizeof(password)-1)
2305 password[pos++] = c;
2309 c_write_str("\r\n");
2313 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2315 * Try public key authentication with the specified
2318 static struct RSAKey pubkey;
2319 static Bignum challenge, response;
2321 static unsigned char buffer[32];
2323 tried_publickey = 1;
2324 i = loadrsakey(cfg.keyfile, &pubkey, password);
2326 c_write_str("Couldn't load private key from ");
2327 c_write_str(cfg.keyfile);
2328 c_write_str(".\r\n");
2329 continue; /* go and try password */
2332 c_write_str("Wrong passphrase.\r\n");
2333 tried_publickey = 0;
2334 continue; /* try again */
2338 * Send a public key attempt.
2340 send_packet(SSH1_CMSG_AUTH_RSA,
2341 PKT_BIGNUM, pubkey.modulus, PKT_END);
2344 if (pktin.type == SSH1_SMSG_FAILURE) {
2345 c_write_str("Server refused our public key.\r\n");
2346 continue; /* go and try password */
2348 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2349 bombout(("Bizarre response to offer of public key"));
2352 ssh1_read_bignum(pktin.body, &challenge);
2353 response = rsadecrypt(challenge, &pubkey);
2354 freebn(pubkey.private_exponent); /* burn the evidence */
2356 for (i = 0; i < 32; i++) {
2357 buffer[i] = bignum_byte(response, 31 - i);
2361 MD5Update(&md5c, buffer, 32);
2362 MD5Update(&md5c, session_id, 16);
2363 MD5Final(buffer, &md5c);
2365 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2366 PKT_DATA, buffer, 16, PKT_END);
2369 if (pktin.type == SSH1_SMSG_FAILURE) {
2370 if (flags & FLAG_VERBOSE)
2372 ("Failed to authenticate with our public key.\r\n");
2373 continue; /* go and try password */
2374 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2376 ("Bizarre response to RSA authentication response"));
2380 break; /* we're through! */
2382 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2384 * Defence against traffic analysis: we send a
2385 * whole bunch of packets containing strings of
2386 * different lengths. One of these strings is the
2387 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2388 * The others are all random data in
2389 * SSH1_MSG_IGNORE packets. This way a passive
2390 * listener can't tell which is the password, and
2391 * hence can't deduce the password length.
2393 * Anybody with a password length greater than 16
2394 * bytes is going to have enough entropy in their
2395 * password that a listener won't find it _that_
2396 * much help to know how long it is. So what we'll
2399 * - if password length < 16, we send 15 packets
2400 * containing string lengths 1 through 15
2402 * - otherwise, we let N be the nearest multiple
2403 * of 8 below the password length, and send 8
2404 * packets containing string lengths N through
2405 * N+7. This won't obscure the order of
2406 * magnitude of the password length, but it will
2407 * introduce a bit of extra uncertainty.
2409 * A few servers (the old 1.2.18 through 1.2.22)
2410 * can't deal with SSH1_MSG_IGNORE. For these
2411 * servers, we need an alternative defence. We make
2412 * use of the fact that the password is interpreted
2413 * as a C string: so we can append a NUL, then some
2416 * One server (a Cisco one) can deal with neither
2417 * SSH1_MSG_IGNORE _nor_ a padded password string.
2418 * For this server we are left with no defences
2419 * against password length sniffing.
2421 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2423 * The server can deal with SSH1_MSG_IGNORE, so
2424 * we can use the primary defence.
2426 int bottom, top, pwlen, i;
2429 pwlen = strlen(password);
2431 bottom = 0; /* zero length passwords are OK! :-) */
2434 bottom = pwlen & ~7;
2438 assert(pwlen >= bottom && pwlen <= top);
2440 randomstr = smalloc(top + 1);
2442 for (i = bottom; i <= top; i++) {
2444 defer_packet(pwpkt_type, PKT_STR, password,
2447 for (j = 0; j < i; j++) {
2449 randomstr[j] = random_byte();
2450 } while (randomstr[j] == '\0');
2452 randomstr[i] = '\0';
2453 defer_packet(SSH1_MSG_IGNORE,
2454 PKT_STR, randomstr, PKT_END);
2457 logevent("Sending password with camouflage packets");
2458 ssh_pkt_defersend();
2460 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2462 * The server can't deal with SSH1_MSG_IGNORE
2463 * but can deal with padded passwords, so we
2464 * can use the secondary defence.
2470 len = strlen(password);
2471 if (len < sizeof(string)) {
2473 strcpy(string, password);
2474 len++; /* cover the zero byte */
2475 while (len < sizeof(string)) {
2476 string[len++] = (char) random_byte();
2481 logevent("Sending length-padded password");
2482 send_packet(pwpkt_type, PKT_INT, len,
2483 PKT_DATA, s, len, PKT_END);
2486 * The server has _both_
2487 * BUG_CHOKES_ON_SSH1_IGNORE and
2488 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2489 * therefore nothing we can do.
2492 len = strlen(password);
2493 logevent("Sending unpadded password");
2494 send_packet(pwpkt_type, PKT_INT, len,
2495 PKT_DATA, password, len, PKT_END);
2498 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2501 logevent("Sent password");
2502 memset(password, 0, strlen(password));
2504 if (pktin.type == SSH1_SMSG_FAILURE) {
2505 if (flags & FLAG_VERBOSE)
2506 c_write_str("Access denied\r\n");
2507 logevent("Authentication refused");
2508 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2509 logevent("Received disconnect request");
2510 ssh_state = SSH_STATE_CLOSED;
2512 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2513 bombout(("Strange packet received, type %d", pktin.type));
2518 logevent("Authentication successful");
2523 void sshfwd_close(struct ssh_channel *c)
2525 if (c && !c->closes) {
2527 * If the channel's remoteid is -1, we have sent
2528 * CHANNEL_OPEN for this channel, but it hasn't even been
2529 * acknowledged by the server. So we must set a close flag
2530 * on it now, and then when the server acks the channel
2531 * open, we can close it then.
2533 if (c->remoteid != -1) {
2534 if (ssh_version == 1) {
2535 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2538 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2539 ssh2_pkt_adduint32(c->remoteid);
2544 if (c->type == CHAN_X11) {
2546 logevent("Forwarded X11 connection terminated");
2547 } else if (c->type == CHAN_SOCKDATA ||
2548 c->type == CHAN_SOCKDATA_DORMANT) {
2550 logevent("Forwarded port closed");
2555 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2557 if (ssh_version == 1) {
2558 send_packet(SSH1_MSG_CHANNEL_DATA,
2559 PKT_INT, c->remoteid,
2560 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2562 * In SSH1 we can return 0 here - implying that forwarded
2563 * connections are never individually throttled - because
2564 * the only circumstance that can cause throttling will be
2565 * the whole SSH connection backing up, in which case
2566 * _everything_ will be throttled as a whole.
2570 ssh2_add_channel_data(c, buf, len);
2571 return ssh2_try_send(c);
2575 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2577 if (ssh_version == 1) {
2578 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2579 c->v.v1.throttling = 0;
2583 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2587 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2593 while (!do_ssh1_login(in, inlen, ispkt)) {
2596 if (ssh_state == SSH_STATE_CLOSED)
2599 if (cfg.agentfwd && agent_exists()) {
2600 logevent("Requesting agent forwarding");
2601 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2605 if (pktin.type != SSH1_SMSG_SUCCESS
2606 && pktin.type != SSH1_SMSG_FAILURE) {
2607 bombout(("Protocol confusion"));
2609 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2610 logevent("Agent forwarding refused");
2612 logevent("Agent forwarding enabled");
2613 ssh_agentfwd_enabled = TRUE;
2617 if (cfg.x11_forward) {
2618 char proto[20], data[64];
2619 logevent("Requesting X11 forwarding");
2620 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2621 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2622 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2623 PKT_STR, proto, PKT_STR, data,
2624 PKT_INT, 0, PKT_END);
2626 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2627 PKT_STR, proto, PKT_STR, data, PKT_END);
2632 if (pktin.type != SSH1_SMSG_SUCCESS
2633 && pktin.type != SSH1_SMSG_FAILURE) {
2634 bombout(("Protocol confusion"));
2636 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2637 logevent("X11 forwarding refused");
2639 logevent("X11 forwarding enabled");
2640 ssh_X11_fwd_enabled = TRUE;
2648 char sports[256], dports[256], host[256];
2651 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2652 /* Add port forwardings. */
2657 while (*e && *e != '\t')
2663 while (*e && *e != ':')
2673 dport = atoi(dports);
2674 sport = atoi(sports);
2675 if (sport && dport) {
2677 pfd_addforward(host, dport, sport);
2678 sprintf(buf, "Local port %d forwarding to %s:%d",
2679 sport, host, dport);
2682 struct ssh_rportfwd *pf;
2683 pf = smalloc(sizeof(*pf));
2684 strcpy(pf->dhost, host);
2686 if (add234(ssh_rportfwds, pf) != pf) {
2688 "Duplicate remote port forwarding to %s:%d",
2693 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2694 sport, host, dport);
2696 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2708 send_packet(SSH1_CMSG_REQUEST_PTY,
2709 PKT_STR, cfg.termtype,
2710 PKT_INT, rows, PKT_INT, cols,
2711 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2712 ssh_state = SSH_STATE_INTERMED;
2716 if (pktin.type != SSH1_SMSG_SUCCESS
2717 && pktin.type != SSH1_SMSG_FAILURE) {
2718 bombout(("Protocol confusion"));
2720 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2721 c_write_str("Server refused to allocate pty\r\n");
2722 ssh_editing = ssh_echoing = 1;
2724 logevent("Allocated pty");
2726 ssh_editing = ssh_echoing = 1;
2729 if (cfg.compression) {
2730 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2734 if (pktin.type != SSH1_SMSG_SUCCESS
2735 && pktin.type != SSH1_SMSG_FAILURE) {
2736 bombout(("Protocol confusion"));
2738 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2739 c_write_str("Server refused to compress\r\n");
2741 logevent("Started compression");
2742 ssh1_compressing = TRUE;
2743 zlib_compress_init();
2744 zlib_decompress_init();
2748 * Start the shell or command.
2750 * Special case: if the first-choice command is an SSH2
2751 * subsystem (hence not usable here) and the second choice
2752 * exists, we fall straight back to that.
2755 char *cmd = cfg.remote_cmd_ptr;
2757 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
2758 cmd = cfg.remote_cmd_ptr2;
2759 ssh_fallback_cmd = TRUE;
2762 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2764 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2765 logevent("Started session");
2768 ssh_state = SSH_STATE_SESSION;
2772 ssh_special(TS_EOF);
2774 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
2776 ssh_channels = newtree234(ssh_channelcmp);
2780 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2781 pktin.type == SSH1_SMSG_STDERR_DATA) {
2782 long len = GET_32BIT(pktin.body);
2784 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2785 pktin.body + 4, len);
2786 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
2787 ssh1_stdout_throttling = 1;
2790 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2791 ssh_state = SSH_STATE_CLOSED;
2792 logevent("Received disconnect request");
2794 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2795 /* Remote side is trying to open a channel to talk to our
2796 * X-Server. Give them back a local channel number. */
2797 struct ssh_channel *c;
2799 logevent("Received X11 connect request");
2800 /* Refuse if X11 forwarding is disabled. */
2801 if (!ssh_X11_fwd_enabled) {
2802 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2803 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2804 logevent("Rejected X11 connect request");
2806 c = smalloc(sizeof(struct ssh_channel));
2808 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2809 logevent("opening X11 forward connection failed");
2811 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2812 PKT_INT, GET_32BIT(pktin.body),
2816 ("opening X11 forward connection succeeded");
2817 c->remoteid = GET_32BIT(pktin.body);
2818 c->localid = alloc_channel_id();
2820 c->v.v1.throttling = 0;
2821 c->type = CHAN_X11; /* identify channel type */
2822 add234(ssh_channels, c);
2823 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2824 PKT_INT, c->remoteid, PKT_INT,
2825 c->localid, PKT_END);
2826 logevent("Opened X11 forward channel");
2829 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2830 /* Remote side is trying to open a channel to talk to our
2831 * agent. Give them back a local channel number. */
2832 struct ssh_channel *c;
2834 /* Refuse if agent forwarding is disabled. */
2835 if (!ssh_agentfwd_enabled) {
2836 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2837 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2839 c = smalloc(sizeof(struct ssh_channel));
2840 c->remoteid = GET_32BIT(pktin.body);
2841 c->localid = alloc_channel_id();
2843 c->v.v1.throttling = 0;
2844 c->type = CHAN_AGENT; /* identify channel type */
2845 c->u.a.lensofar = 0;
2846 add234(ssh_channels, c);
2847 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2848 PKT_INT, c->remoteid, PKT_INT, c->localid,
2851 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2852 /* Remote side is trying to open a channel to talk to a
2853 * forwarded port. Give them back a local channel number. */
2854 struct ssh_channel *c;
2855 struct ssh_rportfwd pf;
2857 char host[256], buf[1024];
2859 c = smalloc(sizeof(struct ssh_channel));
2861 hostsize = GET_32BIT(pktin.body+4);
2862 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2863 if (h+1 < host+sizeof(host))
2868 port = GET_32BIT(p);
2870 strcpy(pf.dhost, host);
2873 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2874 sprintf(buf, "Rejected remote port open request for %s:%d",
2877 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2878 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2880 sprintf(buf, "Received remote port open request for %s:%d",
2883 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2886 sprintf(buf, "Port open failed: %s", e);
2889 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2890 PKT_INT, GET_32BIT(pktin.body),
2893 c->remoteid = GET_32BIT(pktin.body);
2894 c->localid = alloc_channel_id();
2896 c->v.v1.throttling = 0;
2897 c->type = CHAN_SOCKDATA; /* identify channel type */
2898 add234(ssh_channels, c);
2899 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2900 PKT_INT, c->remoteid, PKT_INT,
2901 c->localid, PKT_END);
2902 logevent("Forwarded port opened successfully");
2906 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
2907 unsigned int remoteid = GET_32BIT(pktin.body);
2908 unsigned int localid = GET_32BIT(pktin.body+4);
2909 struct ssh_channel *c;
2911 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2912 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2913 c->remoteid = localid;
2914 c->type = CHAN_SOCKDATA;
2915 pfd_confirm(c->u.pfd.s);
2918 if (c && c->closes) {
2920 * We have a pending close on this channel,
2921 * which we decided on before the server acked
2922 * the channel open. So now we know the
2923 * remoteid, we can close it again.
2925 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2929 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
2930 unsigned int remoteid = GET_32BIT(pktin.body);
2931 unsigned int localid = GET_32BIT(pktin.body+4);
2932 struct ssh_channel *c;
2934 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2935 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2936 logevent("Forwarded connection refused by server");
2937 pfd_close(c->u.pfd.s);
2938 del234(ssh_channels, c);
2942 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2943 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2944 /* Remote side closes a channel. */
2945 unsigned i = GET_32BIT(pktin.body);
2946 struct ssh_channel *c;
2947 c = find234(ssh_channels, &i, ssh_channelfind);
2951 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2952 if (!(c->closes & closetype))
2953 send_packet(pktin.type, PKT_INT, c->remoteid,
2955 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2956 logevent("Forwarded X11 connection terminated");
2957 assert(c->u.x11.s != NULL);
2958 x11_close(c->u.x11.s);
2961 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
2962 logevent("Forwarded port closed");
2963 assert(c->u.pfd.s != NULL);
2964 pfd_close(c->u.pfd.s);
2967 c->closes |= closetype;
2968 if (c->closes == 3) {
2969 del234(ssh_channels, c);
2973 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2974 /* Data sent down one of our channels. */
2975 int i = GET_32BIT(pktin.body);
2976 int len = GET_32BIT(pktin.body + 4);
2977 unsigned char *p = pktin.body + 8;
2978 struct ssh_channel *c;
2979 c = find234(ssh_channels, &i, ssh_channelfind);
2984 bufsize = x11_send(c->u.x11.s, p, len);
2987 bufsize = pfd_send(c->u.pfd.s, p, len);
2990 /* Data for an agent message. Buffer it. */
2992 if (c->u.a.lensofar < 4) {
2993 int l = min(4 - c->u.a.lensofar, len);
2994 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2998 c->u.a.lensofar += l;
3000 if (c->u.a.lensofar == 4) {
3002 4 + GET_32BIT(c->u.a.msglen);
3003 c->u.a.message = smalloc(c->u.a.totallen);
3004 memcpy(c->u.a.message, c->u.a.msglen, 4);
3006 if (c->u.a.lensofar >= 4 && len > 0) {
3008 min(c->u.a.totallen - c->u.a.lensofar,
3010 memcpy(c->u.a.message + c->u.a.lensofar, p,
3014 c->u.a.lensofar += l;
3016 if (c->u.a.lensofar == c->u.a.totallen) {
3017 void *reply, *sentreply;
3019 agent_query(c->u.a.message,
3020 c->u.a.totallen, &reply,
3025 /* Fake SSH_AGENT_FAILURE. */
3026 sentreply = "\0\0\0\1\5";
3029 send_packet(SSH1_MSG_CHANNEL_DATA,
3030 PKT_INT, c->remoteid,
3032 PKT_DATA, sentreply, replylen,
3036 sfree(c->u.a.message);
3037 c->u.a.lensofar = 0;
3040 bufsize = 0; /* agent channels never back up */
3043 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3044 c->v.v1.throttling = 1;
3048 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
3049 /* may be from EXEC_SHELL on some servers */
3050 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3051 /* may be from EXEC_SHELL on some servers
3052 * if no pty is available or in other odd cases. Ignore */
3053 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3054 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3056 * In case `helpful' firewalls or proxies tack
3057 * extra human-readable text on the end of the
3058 * session which we might mistake for another
3059 * encrypted packet, we close the session once
3060 * we've sent EXIT_CONFIRMATION.
3062 ssh_state = SSH_STATE_CLOSED;
3065 bombout(("Strange packet received: type %d", pktin.type));
3070 int len = min(inlen, 512);
3071 send_packet(SSH1_CMSG_STDIN_DATA,
3072 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3083 * Utility routine for decoding comma-separated strings in KEXINIT.
3085 static int in_commasep_string(char *needle, char *haystack, int haylen)
3087 int needlen = strlen(needle);
3090 * Is it at the start of the string?
3092 if (haylen >= needlen && /* haystack is long enough */
3093 !memcmp(needle, haystack, needlen) && /* initial match */
3094 (haylen == needlen || haystack[needlen] == ',')
3095 /* either , or EOS follows */
3099 * If not, search for the next comma and resume after that.
3100 * If no comma found, terminate.
3102 while (haylen > 0 && *haystack != ',')
3103 haylen--, haystack++;
3106 haylen--, haystack++; /* skip over comma itself */
3111 * SSH2 key creation method.
3113 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3117 /* First 20 bytes. */
3120 SHA_Bytes(&s, H, 20);
3121 SHA_Bytes(&s, &chr, 1);
3122 SHA_Bytes(&s, sessid, 20);
3123 SHA_Final(&s, keyspace);
3124 /* Next 20 bytes. */
3127 SHA_Bytes(&s, H, 20);
3128 SHA_Bytes(&s, keyspace, 20);
3129 SHA_Final(&s, keyspace + 20);
3133 * Handle the SSH2 transport layer.
3135 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3137 static int i, j, len, nbits, pbits, warn;
3139 static Bignum p, g, e, f, K;
3140 static int kex_init_value, kex_reply_value;
3141 static const struct ssh_mac **maclist;
3143 static const struct ssh2_cipher *cscipher_tobe = NULL;
3144 static const struct ssh2_cipher *sccipher_tobe = NULL;
3145 static const struct ssh_mac *csmac_tobe = NULL;
3146 static const struct ssh_mac *scmac_tobe = NULL;
3147 static const struct ssh_compress *cscomp_tobe = NULL;
3148 static const struct ssh_compress *sccomp_tobe = NULL;
3149 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3150 static int hostkeylen, siglen;
3151 static void *hkey; /* actual host key */
3152 static unsigned char exchange_hash[20];
3153 static unsigned char keyspace[40];
3154 static int n_preferred_ciphers;
3155 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3156 static const struct ssh_compress *preferred_comp;
3157 static int first_kex;
3164 * Set up the preferred ciphers. (NULL => warn below here)
3166 n_preferred_ciphers = 0;
3167 for (i = 0; i < CIPHER_MAX; i++) {
3168 switch (cfg.ssh_cipherlist[i]) {
3169 case CIPHER_BLOWFISH:
3170 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3171 n_preferred_ciphers++;
3174 /* Not supported in SSH2; silently drop */
3177 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3178 n_preferred_ciphers++;
3181 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3182 n_preferred_ciphers++;
3185 /* Flag for later. Don't bother if it's the last in
3187 if (i < CIPHER_MAX - 1) {
3188 preferred_ciphers[n_preferred_ciphers] = NULL;
3189 n_preferred_ciphers++;
3196 * Set up preferred compression.
3198 if (cfg.compression)
3199 preferred_comp = &ssh_zlib;
3201 preferred_comp = &ssh_comp_none;
3204 * Be prepared to work around the buggy MAC problem.
3206 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3207 maclist = buggymacs, nmacs = lenof(buggymacs);
3209 maclist = macs, nmacs = lenof(macs);
3213 * Construct and send our key exchange packet.
3215 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3216 for (i = 0; i < 16; i++)
3217 ssh2_pkt_addbyte((unsigned char) random_byte());
3218 /* List key exchange algorithms. */
3219 ssh2_pkt_addstring_start();
3220 for (i = 0; i < lenof(kex_algs); i++) {
3221 ssh2_pkt_addstring_str(kex_algs[i]->name);
3222 if (i < lenof(kex_algs) - 1)
3223 ssh2_pkt_addstring_str(",");
3225 /* List server host key algorithms. */
3226 ssh2_pkt_addstring_start();
3227 for (i = 0; i < lenof(hostkey_algs); i++) {
3228 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3229 if (i < lenof(hostkey_algs) - 1)
3230 ssh2_pkt_addstring_str(",");
3232 /* List client->server encryption algorithms. */
3233 ssh2_pkt_addstring_start();
3234 for (i = 0; i < n_preferred_ciphers; i++) {
3235 const struct ssh2_ciphers *c = preferred_ciphers[i];
3236 if (!c) continue; /* warning flag */
3237 for (j = 0; j < c->nciphers; j++) {
3238 ssh2_pkt_addstring_str(c->list[j]->name);
3239 if (i < n_preferred_ciphers || j < c->nciphers - 1)
3240 ssh2_pkt_addstring_str(",");
3243 /* List server->client encryption algorithms. */
3244 ssh2_pkt_addstring_start();
3245 for (i = 0; i < n_preferred_ciphers; i++) {
3246 const struct ssh2_ciphers *c = preferred_ciphers[i];
3247 if (!c) continue; /* warning flag */
3248 for (j = 0; j < c->nciphers; j++) {
3249 ssh2_pkt_addstring_str(c->list[j]->name);
3250 if (i < n_preferred_ciphers || j < c->nciphers - 1)
3251 ssh2_pkt_addstring_str(",");
3254 /* List client->server MAC algorithms. */
3255 ssh2_pkt_addstring_start();
3256 for (i = 0; i < nmacs; i++) {
3257 ssh2_pkt_addstring_str(maclist[i]->name);
3259 ssh2_pkt_addstring_str(",");
3261 /* List server->client MAC algorithms. */
3262 ssh2_pkt_addstring_start();
3263 for (i = 0; i < nmacs; i++) {
3264 ssh2_pkt_addstring_str(maclist[i]->name);
3266 ssh2_pkt_addstring_str(",");
3268 /* List client->server compression algorithms. */
3269 ssh2_pkt_addstring_start();
3270 for (i = 0; i < lenof(compressions) + 1; i++) {
3271 const struct ssh_compress *c =
3272 i == 0 ? preferred_comp : compressions[i - 1];
3273 ssh2_pkt_addstring_str(c->name);
3274 if (i < lenof(compressions))
3275 ssh2_pkt_addstring_str(",");
3277 /* List server->client compression algorithms. */
3278 ssh2_pkt_addstring_start();
3279 for (i = 0; i < lenof(compressions) + 1; i++) {
3280 const struct ssh_compress *c =
3281 i == 0 ? preferred_comp : compressions[i - 1];
3282 ssh2_pkt_addstring_str(c->name);
3283 if (i < lenof(compressions))
3284 ssh2_pkt_addstring_str(",");
3286 /* List client->server languages. Empty list. */
3287 ssh2_pkt_addstring_start();
3288 /* List server->client languages. Empty list. */
3289 ssh2_pkt_addstring_start();
3290 /* First KEX packet does _not_ follow, because we're not that brave. */
3291 ssh2_pkt_addbool(FALSE);
3293 ssh2_pkt_adduint32(0);
3295 exhash = exhashbase;
3296 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3302 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3305 * Now examine the other side's KEXINIT to see what we're up
3308 if (pktin.type != SSH2_MSG_KEXINIT) {
3309 bombout(("expected key exchange packet from server"));
3314 cscipher_tobe = NULL;
3315 sccipher_tobe = NULL;
3320 pktin.savedpos += 16; /* skip garbage cookie */
3321 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3322 for (i = 0; i < lenof(kex_algs); i++) {
3323 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3328 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3329 for (i = 0; i < lenof(hostkey_algs); i++) {
3330 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3331 hostkey = hostkey_algs[i];
3335 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3337 for (i = 0; i < n_preferred_ciphers; i++) {
3338 const struct ssh2_ciphers *c = preferred_ciphers[i];
3342 for (j = 0; j < c->nciphers; j++) {
3343 if (in_commasep_string(c->list[j]->name, str, len)) {
3344 cscipher_tobe = c->list[j];
3349 if (cscipher_tobe) {
3351 askcipher(cscipher_tobe->name, 1);
3355 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3357 for (i = 0; i < n_preferred_ciphers; i++) {
3358 const struct ssh2_ciphers *c = preferred_ciphers[i];
3362 for (j = 0; j < c->nciphers; j++) {
3363 if (in_commasep_string(c->list[j]->name, str, len)) {
3364 sccipher_tobe = c->list[j];
3369 if (sccipher_tobe) {
3371 askcipher(sccipher_tobe->name, 2);
3375 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3376 for (i = 0; i < nmacs; i++) {
3377 if (in_commasep_string(maclist[i]->name, str, len)) {
3378 csmac_tobe = maclist[i];
3382 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3383 for (i = 0; i < nmacs; i++) {
3384 if (in_commasep_string(maclist[i]->name, str, len)) {
3385 scmac_tobe = maclist[i];
3389 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3390 for (i = 0; i < lenof(compressions) + 1; i++) {
3391 const struct ssh_compress *c =
3392 i == 0 ? preferred_comp : compressions[i - 1];
3393 if (in_commasep_string(c->name, str, len)) {
3398 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3399 for (i = 0; i < lenof(compressions) + 1; i++) {
3400 const struct ssh_compress *c =
3401 i == 0 ? preferred_comp : compressions[i - 1];
3402 if (in_commasep_string(c->name, str, len)) {
3409 * Work out the number of bits of key we will need from the key
3410 * exchange. We start with the maximum key length of either
3416 csbits = cscipher_tobe->keylen;
3417 scbits = sccipher_tobe->keylen;
3418 nbits = (csbits > scbits ? csbits : scbits);
3420 /* The keys only have 160-bit entropy, since they're based on
3421 * a SHA-1 hash. So cap the key size at 160 bits. */
3426 * If we're doing Diffie-Hellman group exchange, start by
3427 * requesting a group.
3429 if (kex == &ssh_diffiehellman_gex) {
3430 logevent("Doing Diffie-Hellman group exchange");
3432 * Work out how big a DH group we will need to allow that
3435 pbits = 512 << ((nbits - 1) / 64);
3436 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3437 ssh2_pkt_adduint32(pbits);
3441 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3442 bombout(("expected key exchange group packet from server"));
3445 p = ssh2_pkt_getmp();
3446 g = ssh2_pkt_getmp();
3447 dh_setup_group(p, g);
3448 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3449 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3452 kex_init_value = SSH2_MSG_KEXDH_INIT;
3453 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3456 logevent("Doing Diffie-Hellman key exchange");
3458 * Now generate and send e for Diffie-Hellman.
3460 e = dh_create_e(nbits * 2);
3461 ssh2_pkt_init(kex_init_value);
3466 if (pktin.type != kex_reply_value) {
3467 bombout(("expected key exchange reply packet from server"));
3470 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3471 f = ssh2_pkt_getmp();
3472 ssh2_pkt_getstring(&sigdata, &siglen);
3476 sha_string(&exhash, hostkeydata, hostkeylen);
3477 if (kex == &ssh_diffiehellman_gex) {
3478 sha_uint32(&exhash, pbits);
3479 sha_mpint(&exhash, p);
3480 sha_mpint(&exhash, g);
3482 sha_mpint(&exhash, e);
3483 sha_mpint(&exhash, f);
3484 sha_mpint(&exhash, K);
3485 SHA_Final(&exhash, exchange_hash);
3490 debug(("Exchange hash is:\n"));
3491 dmemdump(exchange_hash, 20);
3494 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3496 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3497 bombout(("Server's host key did not match the signature supplied"));
3502 * Expect SSH2_MSG_NEWKEYS from server.
3505 if (pktin.type != SSH2_MSG_NEWKEYS) {
3506 bombout(("expected new-keys packet from server"));
3511 * Authenticate remote host: verify host key. (We've already
3512 * checked the signature of the exchange hash.)
3514 keystr = hostkey->fmtkey(hkey);
3515 fingerprint = hostkey->fingerprint(hkey);
3516 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3517 keystr, fingerprint);
3518 if (first_kex) { /* don't bother logging this in rekeys */
3519 logevent("Host key fingerprint is:");
3520 logevent(fingerprint);
3524 hostkey->freekey(hkey);
3527 * Send SSH2_MSG_NEWKEYS.
3529 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3533 * Create and initialise session keys.
3535 cscipher = cscipher_tobe;
3536 sccipher = sccipher_tobe;
3539 cscomp = cscomp_tobe;
3540 sccomp = sccomp_tobe;
3541 cscomp->compress_init();
3542 sccomp->decompress_init();
3544 * Set IVs after keys. Here we use the exchange hash from the
3545 * _first_ key exchange.
3548 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3549 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3550 cscipher->setcskey(keyspace);
3551 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3552 sccipher->setsckey(keyspace);
3553 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3554 cscipher->setcsiv(keyspace);
3555 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3556 sccipher->setsciv(keyspace);
3557 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3558 csmac->setcskey(keyspace);
3559 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3560 scmac->setsckey(keyspace);
3563 * If this is the first key exchange phase, we must pass the
3564 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3565 * wants to see it but because it will need time to initialise
3566 * itself before it sees an actual packet. In subsequent key
3567 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3568 * it would only confuse the layer above.
3576 * Now we're encrypting. Begin returning 1 to the protocol main
3577 * function so that other things can run on top of the
3578 * transport. If we ever see a KEXINIT, we must go back to the
3581 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3584 logevent("Server initiated key re-exchange");
3585 goto begin_key_exchange;
3591 * Add data to an SSH2 channel output buffer.
3593 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3596 bufchain_add(&c->v.v2.outbuffer, buf, len);
3600 * Attempt to send data on an SSH2 channel.
3602 static int ssh2_try_send(struct ssh_channel *c)
3604 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3607 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3608 if ((unsigned)len > c->v.v2.remwindow)
3609 len = c->v.v2.remwindow;
3610 if ((unsigned)len > c->v.v2.remmaxpkt)
3611 len = c->v.v2.remmaxpkt;
3612 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3613 ssh2_pkt_adduint32(c->remoteid);
3614 ssh2_pkt_addstring_start();
3615 ssh2_pkt_addstring_data(data, len);
3617 bufchain_consume(&c->v.v2.outbuffer, len);
3618 c->v.v2.remwindow -= len;
3622 * After having sent as much data as we can, return the amount
3625 return bufchain_size(&c->v.v2.outbuffer);
3629 * Potentially enlarge the window on an SSH2 channel.
3631 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3633 if (newwin > c->v.v2.locwindow) {
3634 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3635 ssh2_pkt_adduint32(c->remoteid);
3636 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
3638 c->v.v2.locwindow = newwin;
3643 * Handle the SSH2 userauth and connection layers.
3645 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3648 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3650 AUTH_KEYBOARD_INTERACTIVE
3654 AUTH_TYPE_PUBLICKEY,
3655 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3656 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3658 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3659 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3661 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3662 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
3663 static int kbd_inter_running;
3664 static int we_are_in;
3665 static int num_prompts, echo;
3666 static char username[100];
3667 static char pwprompt[200];
3668 static char password[100];
3673 * Request userauth protocol, and await a response to it.
3675 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3676 ssh2_pkt_addstring("ssh-userauth");
3678 crWaitUntilV(ispkt);
3679 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3680 bombout(("Server refused user authentication protocol"));
3685 * We repeat this whole loop, including the username prompt,
3686 * until we manage a successful authentication. If the user
3687 * types the wrong _password_, they are sent back to the
3688 * beginning to try another username. (If they specify a
3689 * username in the config, they are never asked, even if they
3690 * do give a wrong password.)
3692 * I think this best serves the needs of
3694 * - the people who have no configuration, no keys, and just
3695 * want to try repeated (username,password) pairs until they
3696 * type both correctly
3698 * - people who have keys and configuration but occasionally
3699 * need to fall back to passwords
3701 * - people with a key held in Pageant, who might not have
3702 * logged in to a particular machine before; so they want to
3703 * type a username, and then _either_ their key will be
3704 * accepted, _or_ they will type a password. If they mistype
3705 * the username they will want to be able to get back and
3716 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3718 if (!ssh_get_line("login as: ",
3719 username, sizeof(username), FALSE)) {
3721 * get_line failed to get a username.
3724 logevent("No username provided. Abandoning session.");
3725 ssh_state = SSH_STATE_CLOSED;
3729 c_write_str("login as: ");
3732 crWaitUntilV(!ispkt);
3734 switch (c = *in++) {
3743 c_write_str("\b \b");
3750 c_write_str("\b \b");
3760 if (((c >= ' ' && c <= '~') ||
3761 ((unsigned char) c >= 160))
3762 && pos < sizeof(username)-1) {
3763 username[pos++] = c;
3770 c_write_str("\r\n");
3771 username[strcspn(username, "\n\r")] = '\0';
3774 strncpy(username, cfg.username, 99);
3775 username[99] = '\0';
3776 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3777 sprintf(stuff, "Using username \"%s\".\r\n", username);
3783 * Send an authentication request using method "none": (a)
3784 * just in case it succeeds, and (b) so that we know what
3785 * authentication methods we can usefully try next.
3787 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3788 ssh2_pkt_addstring(username);
3789 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3790 ssh2_pkt_addstring("none"); /* method */
3792 type = AUTH_TYPE_NONE;
3796 tried_pubkey_config = FALSE;
3797 tried_agent = FALSE;
3798 tried_keyb_inter = FALSE;
3799 kbd_inter_running = FALSE;
3803 * Wait for the result of the last authentication request.
3806 crWaitUntilV(ispkt);
3807 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3811 * Don't show the banner if we're operating in
3812 * non-verbose non-interactive mode. (It's probably
3813 * a script, which means nobody will read the
3814 * banner _anyway_, and moreover the printing of
3815 * the banner will screw up processing on the
3816 * output of (say) plink.)
3818 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3819 ssh2_pkt_getstring(&banner, &size);
3821 c_write_untrusted(banner, size);
3823 crWaitUntilV(ispkt);
3825 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3826 logevent("Access granted");
3831 if (kbd_inter_running &&
3832 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
3834 * This is a further prompt in keyboard-interactive
3835 * authentication. Do nothing.
3837 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3838 bombout(("Strange packet received during authentication: type %d",
3846 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3847 * we can look at the string in it and know what we can
3848 * helpfully try next.
3850 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
3853 ssh2_pkt_getstring(&methods, &methlen);
3854 kbd_inter_running = FALSE;
3855 if (!ssh2_pkt_getbool()) {
3857 * We have received an unequivocal Access
3858 * Denied. This can translate to a variety of
3861 * - if we'd just tried "none" authentication,
3862 * it's not worth printing anything at all
3864 * - if we'd just tried a public key _offer_,
3865 * the message should be "Server refused our
3866 * key" (or no message at all if the key
3867 * came from Pageant)
3869 * - if we'd just tried anything else, the
3870 * message really should be "Access denied".
3872 * Additionally, if we'd just tried password
3873 * authentication, we should break out of this
3874 * whole loop so as to go back to the username
3877 if (type == AUTH_TYPE_NONE) {
3879 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3880 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3881 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3882 c_write_str("Server refused our key\r\n");
3883 logevent("Server refused public key");
3884 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
3885 /* server declined keyboard-interactive; ignore */
3887 c_write_str("Access denied\r\n");
3888 logevent("Access denied");
3889 if (type == AUTH_TYPE_PASSWORD) {
3895 c_write_str("Further authentication required\r\n");
3896 logevent("Further authentication required");
3900 in_commasep_string("publickey", methods, methlen);
3902 in_commasep_string("password", methods, methlen);
3904 in_commasep_string("keyboard-interactive", methods, methlen);
3909 if (!method && can_pubkey && agent_exists() && !tried_agent) {
3911 * Attempt public-key authentication using Pageant.
3913 static unsigned char request[5], *response, *p;
3914 static int responselen;
3915 static int i, nkeys;
3916 static int authed = FALSE;
3921 logevent("Pageant is running. Requesting keys.");
3923 /* Request the keys held by the agent. */
3924 PUT_32BIT(request, 1);
3925 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3926 agent_query(request, 5, &r, &responselen);
3927 response = (unsigned char *) r;
3928 if (response && responselen >= 5 &&
3929 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3931 nkeys = GET_32BIT(p);
3935 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3938 for (i = 0; i < nkeys; i++) {
3939 static char *pkblob, *alg, *commentp;
3940 static int pklen, alglen, commentlen;
3941 static int siglen, retlen, len;
3942 static char *q, *agentreq, *ret;
3947 sprintf(buf, "Trying Pageant key #%d", i);
3950 pklen = GET_32BIT(p);
3954 alglen = GET_32BIT(pkblob);
3956 commentlen = GET_32BIT(p);
3960 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3961 ssh2_pkt_addstring(username);
3962 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3963 ssh2_pkt_addstring("publickey"); /* method */
3964 ssh2_pkt_addbool(FALSE); /* no signature included */
3965 ssh2_pkt_addstring_start();
3966 ssh2_pkt_addstring_data(alg, alglen);
3967 ssh2_pkt_addstring_start();
3968 ssh2_pkt_addstring_data(pkblob, pklen);
3971 crWaitUntilV(ispkt);
3972 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3973 logevent("Key refused");
3977 if (flags & FLAG_VERBOSE) {
3979 ("Authenticating with public key \"");
3980 c_write(commentp, commentlen);
3981 c_write_str("\" from agent\r\n");
3985 * Server is willing to accept the key.
3986 * Construct a SIGN_REQUEST.
3988 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3989 ssh2_pkt_addstring(username);
3990 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3991 ssh2_pkt_addstring("publickey"); /* method */
3992 ssh2_pkt_addbool(TRUE);
3993 ssh2_pkt_addstring_start();
3994 ssh2_pkt_addstring_data(alg, alglen);
3995 ssh2_pkt_addstring_start();
3996 ssh2_pkt_addstring_data(pkblob, pklen);
3998 siglen = pktout.length - 5 + 4 + 20;
3999 len = 1; /* message type */
4000 len += 4 + pklen; /* key blob */
4001 len += 4 + siglen; /* data to sign */
4002 len += 4; /* flags */
4003 agentreq = smalloc(4 + len);
4004 PUT_32BIT(agentreq, len);
4006 *q++ = SSH2_AGENTC_SIGN_REQUEST;
4007 PUT_32BIT(q, pklen);
4009 memcpy(q, pkblob, pklen);
4011 PUT_32BIT(q, siglen);
4013 /* Now the data to be signed... */
4016 memcpy(q, ssh2_session_id, 20);
4018 memcpy(q, pktout.data + 5, pktout.length - 5);
4019 q += pktout.length - 5;
4020 /* And finally the (zero) flags word. */
4022 agent_query(agentreq, len + 4, &vret, &retlen);
4026 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4027 logevent("Sending Pageant's response");
4028 ssh2_pkt_addstring_start();
4029 ssh2_pkt_addstring_data(ret + 9,
4037 ("Pageant failed to answer challenge");
4047 if (!method && can_pubkey && *cfg.keyfile
4048 && !tried_pubkey_config) {
4049 unsigned char *pub_blob;
4050 char *algorithm, *comment;
4053 tried_pubkey_config = TRUE;
4056 * Try the public key supplied in the configuration.
4058 * First, offer the public blob to see if the server is
4059 * willing to accept it.
4061 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4064 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4065 ssh2_pkt_addstring(username);
4066 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4067 ssh2_pkt_addstring("publickey"); /* method */
4068 ssh2_pkt_addbool(FALSE); /* no signature included */
4069 ssh2_pkt_addstring(algorithm);
4070 ssh2_pkt_addstring_start();
4071 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4073 logevent("Offered public key"); /* FIXME */
4075 crWaitUntilV(ispkt);
4076 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4078 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4079 continue; /* key refused; give up on it */
4082 logevent("Offer of public key accepted");
4084 * Actually attempt a serious authentication using
4087 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4089 "Passphrase for key \"%.100s\": ",
4095 c_write_str("Authenticating with public key \"");
4096 c_write_str(comment);
4097 c_write_str("\"\r\n");
4098 method = AUTH_PUBLICKEY_FILE;
4102 if (!method && can_keyb_inter && !tried_keyb_inter) {
4103 method = AUTH_KEYBOARD_INTERACTIVE;
4104 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4105 tried_keyb_inter = TRUE;
4107 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4108 ssh2_pkt_addstring(username);
4109 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4110 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4111 ssh2_pkt_addstring(""); /* lang */
4112 ssh2_pkt_addstring("");
4115 crWaitUntilV(ispkt);
4116 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4117 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4119 logevent("Keyboard-interactive authentication refused");
4120 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4124 kbd_inter_running = TRUE;
4127 if (kbd_inter_running) {
4128 method = AUTH_KEYBOARD_INTERACTIVE;
4129 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4130 tried_keyb_inter = TRUE;
4132 /* We've got packet with that "interactive" info
4133 dump banners, and set its prompt as ours */
4135 char *name, *inst, *lang, *prompt;
4136 int name_len, inst_len, lang_len, prompt_len;
4137 ssh2_pkt_getstring(&name, &name_len);
4138 ssh2_pkt_getstring(&inst, &inst_len);
4139 ssh2_pkt_getstring(&lang, &lang_len);
4141 c_write_untrusted(name, name_len);
4143 c_write_untrusted(inst, inst_len);
4144 num_prompts = ssh2_pkt_getuint32();
4146 ssh2_pkt_getstring(&prompt, &prompt_len);
4147 strncpy(pwprompt, prompt, sizeof(pwprompt));
4150 echo = ssh2_pkt_getbool();
4154 if (!method && can_passwd) {
4155 method = AUTH_PASSWORD;
4156 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4163 if (!ssh_get_line(pwprompt, password,
4164 sizeof(password), TRUE)) {
4166 * get_line failed to get a password (for
4167 * example because one was supplied on the
4168 * command line which has already failed to
4171 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4172 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4174 ("No more passwords available to try");
4175 ssh2_pkt_addstring("en"); /* language tag */
4177 connection_fatal("Unable to authenticate");
4178 ssh_state = SSH_STATE_CLOSED;
4185 c_write_untrusted(pwprompt, strlen(pwprompt));
4190 crWaitUntilV(!ispkt);
4192 switch (c = *in++) {
4213 if (pos < sizeof(password)-1)
4214 password[pos++] = c;
4218 c_write_str("\r\n");
4222 if (method == AUTH_PUBLICKEY_FILE) {
4224 * We have our passphrase. Now try the actual authentication.
4226 struct ssh2_userkey *key;
4228 key = ssh2_load_userkey(cfg.keyfile, password);
4229 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4230 if (key == SSH2_WRONG_PASSPHRASE) {
4231 c_write_str("Wrong passphrase\r\n");
4232 tried_pubkey_config = FALSE;
4234 c_write_str("Unable to load private key\r\n");
4235 tried_pubkey_config = TRUE;
4237 /* Send a spurious AUTH_NONE to return to the top. */
4238 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4239 ssh2_pkt_addstring(username);
4240 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4241 ssh2_pkt_addstring("none"); /* method */
4243 type = AUTH_TYPE_NONE;
4245 unsigned char *blob, *sigdata;
4246 int blob_len, sigdata_len;
4249 * We have loaded the private key and the server
4250 * has announced that it's willing to accept it.
4251 * Hallelujah. Generate a signature and send it.
4253 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4254 ssh2_pkt_addstring(username);
4255 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4256 ssh2_pkt_addstring("publickey"); /* method */
4257 ssh2_pkt_addbool(TRUE);
4258 ssh2_pkt_addstring(key->alg->name);
4259 blob = key->alg->public_blob(key->data, &blob_len);
4260 ssh2_pkt_addstring_start();
4261 ssh2_pkt_addstring_data(blob, blob_len);
4265 * The data to be signed is:
4269 * followed by everything so far placed in the
4272 sigdata_len = pktout.length - 5 + 4 + 20;
4273 sigdata = smalloc(sigdata_len);
4274 PUT_32BIT(sigdata, 20);
4275 memcpy(sigdata + 4, ssh2_session_id, 20);
4276 memcpy(sigdata + 24, pktout.data + 5,
4279 key->alg->sign(key->data, sigdata, sigdata_len,
4281 ssh2_pkt_addstring_start();
4282 ssh2_pkt_addstring_data(blob, blob_len);
4287 type = AUTH_TYPE_PUBLICKEY;
4289 } else if (method == AUTH_PASSWORD) {
4291 * We send the password packet lumped tightly together with
4292 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4293 * string long enough to make the total length of the two
4294 * packets constant. This should ensure that a passive
4295 * listener doing traffic analyis can't work out the length
4298 * For this to work, we need an assumption about the
4299 * maximum length of the password packet. I think 256 is
4300 * pretty conservative. Anyone using a password longer than
4301 * that probably doesn't have much to worry about from
4302 * people who find out how long their password is!
4304 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4305 ssh2_pkt_addstring(username);
4306 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4307 ssh2_pkt_addstring("password");
4308 ssh2_pkt_addbool(FALSE);
4309 ssh2_pkt_addstring(password);
4312 * We'll include a string that's an exact multiple of the
4313 * cipher block size. If the cipher is NULL for some
4314 * reason, we don't do this trick at all because we gain
4320 stringlen = (256 - deferred_len);
4321 stringlen += cscipher->blksize - 1;
4322 stringlen -= (stringlen % cscipher->blksize);
4325 * Temporarily disable actual compression,
4326 * so we can guarantee to get this string
4327 * exactly the length we want it. The
4328 * compression-disabling routine should
4329 * return an integer indicating how many
4330 * bytes we should adjust our string length
4333 stringlen -= cscomp->disable_compression();
4335 ssh2_pkt_init(SSH2_MSG_IGNORE);
4336 ssh2_pkt_addstring_start();
4337 for (i = 0; i < stringlen; i++) {
4338 char c = (char) random_byte();
4339 ssh2_pkt_addstring_data(&c, 1);
4343 ssh_pkt_defersend();
4344 logevent("Sent password");
4345 type = AUTH_TYPE_PASSWORD;
4346 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4347 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4348 ssh2_pkt_adduint32(num_prompts);
4349 ssh2_pkt_addstring(password);
4350 memset(password, 0, sizeof(password));
4352 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4355 ("No supported authentication methods left to try!\r\n");
4357 ("No supported authentications offered. Disconnecting");
4358 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4359 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4361 ("No supported authentication methods available");
4362 ssh2_pkt_addstring("en"); /* language tag */
4364 ssh_state = SSH_STATE_CLOSED;
4368 } while (!we_are_in);
4371 * Now we're authenticated for the connection protocol. The
4372 * connection protocol will automatically have started at this
4373 * point; there's no need to send SERVICE_REQUEST.
4377 * So now create a channel with a session in it.
4379 ssh_channels = newtree234(ssh_channelcmp);
4380 mainchan = smalloc(sizeof(struct ssh_channel));
4381 mainchan->localid = alloc_channel_id();
4382 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4383 ssh2_pkt_addstring("session");
4384 ssh2_pkt_adduint32(mainchan->localid);
4385 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4386 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4387 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4389 crWaitUntilV(ispkt);
4390 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4391 bombout(("Server refused to open a session"));
4393 /* FIXME: error data comes back in FAILURE packet */
4395 if (ssh2_pkt_getuint32() != mainchan->localid) {
4396 bombout(("Server's channel confirmation cited wrong channel"));
4399 mainchan->remoteid = ssh2_pkt_getuint32();
4400 mainchan->type = CHAN_MAINSESSION;
4401 mainchan->closes = 0;
4402 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4403 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4404 bufchain_init(&mainchan->v.v2.outbuffer);
4405 add234(ssh_channels, mainchan);
4406 logevent("Opened channel for session");
4409 * Potentially enable X11 forwarding.
4411 if (cfg.x11_forward) {
4412 char proto[20], data[64];
4413 logevent("Requesting X11 forwarding");
4414 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4415 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4416 ssh2_pkt_adduint32(mainchan->remoteid);
4417 ssh2_pkt_addstring("x11-req");
4418 ssh2_pkt_addbool(1); /* want reply */
4419 ssh2_pkt_addbool(0); /* many connections */
4420 ssh2_pkt_addstring(proto);
4421 ssh2_pkt_addstring(data);
4422 ssh2_pkt_adduint32(0); /* screen number */
4426 crWaitUntilV(ispkt);
4427 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4428 unsigned i = ssh2_pkt_getuint32();
4429 struct ssh_channel *c;
4430 c = find234(ssh_channels, &i, ssh_channelfind);
4432 continue; /* nonexistent channel */
4433 c->v.v2.remwindow += ssh2_pkt_getuint32();
4435 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4437 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4438 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4439 bombout(("Unexpected response to X11 forwarding request:"
4440 " packet type %d", pktin.type));
4443 logevent("X11 forwarding refused");
4445 logevent("X11 forwarding enabled");
4446 ssh_X11_fwd_enabled = TRUE;
4451 * Enable port forwardings.
4454 static char *e; /* preserve across crReturn */
4458 char sports[256], dports[256], host[256];
4461 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4462 /* Add port forwardings. */
4467 while (*e && *e != '\t')
4473 while (*e && *e != ':')
4483 dport = atoi(dports);
4484 sport = atoi(sports);
4485 if (sport && dport) {
4487 pfd_addforward(host, dport, sport);
4488 sprintf(buf, "Local port %d forwarding to %s:%d",
4489 sport, host, dport);
4492 struct ssh_rportfwd *pf;
4493 pf = smalloc(sizeof(*pf));
4494 strcpy(pf->dhost, host);
4497 if (add234(ssh_rportfwds, pf) != pf) {
4499 "Duplicate remote port forwarding to %s:%d",
4504 sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
4505 sport, host, dport);
4507 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4508 ssh2_pkt_addstring("tcpip-forward");
4509 ssh2_pkt_addbool(1);/* want reply */
4510 ssh2_pkt_addstring("127.0.0.1");
4511 ssh2_pkt_adduint32(sport);
4515 crWaitUntilV(ispkt);
4516 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4517 unsigned i = ssh2_pkt_getuint32();
4518 struct ssh_channel *c;
4519 c = find234(ssh_channels, &i, ssh_channelfind);
4521 continue;/* nonexistent channel */
4522 c->v.v2.remwindow += ssh2_pkt_getuint32();
4524 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4526 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4527 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
4528 bombout(("Unexpected response to port "
4529 "forwarding request: packet type %d",
4533 logevent("Server refused this port forwarding");
4535 logevent("Remote port forwarding enabled");
4544 * Potentially enable agent forwarding.
4546 if (cfg.agentfwd && agent_exists()) {
4547 logevent("Requesting OpenSSH-style agent forwarding");
4548 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4549 ssh2_pkt_adduint32(mainchan->remoteid);
4550 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4551 ssh2_pkt_addbool(1); /* want reply */
4555 crWaitUntilV(ispkt);
4556 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4557 unsigned i = ssh2_pkt_getuint32();
4558 struct ssh_channel *c;
4559 c = find234(ssh_channels, &i, ssh_channelfind);
4561 continue; /* nonexistent channel */
4562 c->v.v2.remwindow += ssh2_pkt_getuint32();
4564 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4566 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4567 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4568 bombout(("Unexpected response to agent forwarding request:"
4569 " packet type %d", pktin.type));
4572 logevent("Agent forwarding refused");
4574 logevent("Agent forwarding enabled");
4575 ssh_agentfwd_enabled = TRUE;
4580 * Now allocate a pty for the session.
4583 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4584 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4585 ssh2_pkt_addstring("pty-req");
4586 ssh2_pkt_addbool(1); /* want reply */
4587 ssh2_pkt_addstring(cfg.termtype);
4588 ssh2_pkt_adduint32(cols);
4589 ssh2_pkt_adduint32(rows);
4590 ssh2_pkt_adduint32(0); /* pixel width */
4591 ssh2_pkt_adduint32(0); /* pixel height */
4592 ssh2_pkt_addstring_start();
4593 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4595 ssh_state = SSH_STATE_INTERMED;
4598 crWaitUntilV(ispkt);
4599 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4600 unsigned i = ssh2_pkt_getuint32();
4601 struct ssh_channel *c;
4602 c = find234(ssh_channels, &i, ssh_channelfind);
4604 continue; /* nonexistent channel */
4605 c->v.v2.remwindow += ssh2_pkt_getuint32();
4607 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4609 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4610 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4611 bombout(("Unexpected response to pty request:"
4612 " packet type %d", pktin.type));
4615 c_write_str("Server refused to allocate pty\r\n");
4616 ssh_editing = ssh_echoing = 1;
4618 logevent("Allocated pty");
4621 ssh_editing = ssh_echoing = 1;
4625 * Start a shell or a remote command. We may have to attempt
4626 * this twice if the config data has provided a second choice
4633 if (ssh_fallback_cmd) {
4634 subsys = cfg.ssh_subsys2;
4635 cmd = cfg.remote_cmd_ptr2;
4637 subsys = cfg.ssh_subsys;
4638 cmd = cfg.remote_cmd_ptr;
4641 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4642 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4644 ssh2_pkt_addstring("subsystem");
4645 ssh2_pkt_addbool(1); /* want reply */
4646 ssh2_pkt_addstring(cmd);
4648 ssh2_pkt_addstring("exec");
4649 ssh2_pkt_addbool(1); /* want reply */
4650 ssh2_pkt_addstring(cmd);
4652 ssh2_pkt_addstring("shell");
4653 ssh2_pkt_addbool(1); /* want reply */
4657 crWaitUntilV(ispkt);
4658 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4659 unsigned i = ssh2_pkt_getuint32();
4660 struct ssh_channel *c;
4661 c = find234(ssh_channels, &i, ssh_channelfind);
4663 continue; /* nonexistent channel */
4664 c->v.v2.remwindow += ssh2_pkt_getuint32();
4666 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4667 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4668 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4669 bombout(("Unexpected response to shell/command request:"
4670 " packet type %d", pktin.type));
4674 * We failed to start the command. If this is the
4675 * fallback command, we really are finished; if it's
4676 * not, and if the fallback command exists, try falling
4677 * back to it before complaining.
4679 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
4680 logevent("Primary command failed; attempting fallback");
4681 ssh_fallback_cmd = TRUE;
4684 bombout(("Server refused to start a shell/command"));
4687 logevent("Started a shell/command");
4692 ssh_state = SSH_STATE_SESSION;
4696 ssh_special(TS_EOF);
4701 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
4704 static int try_send;
4708 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
4709 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4712 unsigned i = ssh2_pkt_getuint32();
4713 struct ssh_channel *c;
4714 c = find234(ssh_channels, &i, ssh_channelfind);
4716 continue; /* nonexistent channel */
4717 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4718 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4719 continue; /* extended but not stderr */
4720 ssh2_pkt_getstring(&data, &length);
4723 c->v.v2.locwindow -= length;
4725 case CHAN_MAINSESSION:
4727 from_backend(pktin.type ==
4728 SSH2_MSG_CHANNEL_EXTENDED_DATA,
4732 bufsize = x11_send(c->u.x11.s, data, length);
4735 bufsize = pfd_send(c->u.pfd.s, data, length);
4738 while (length > 0) {
4739 if (c->u.a.lensofar < 4) {
4740 int l = min(4 - c->u.a.lensofar, length);
4741 memcpy(c->u.a.msglen + c->u.a.lensofar,
4745 c->u.a.lensofar += l;
4747 if (c->u.a.lensofar == 4) {
4749 4 + GET_32BIT(c->u.a.msglen);
4750 c->u.a.message = smalloc(c->u.a.totallen);
4751 memcpy(c->u.a.message, c->u.a.msglen, 4);
4753 if (c->u.a.lensofar >= 4 && length > 0) {
4755 min(c->u.a.totallen - c->u.a.lensofar,
4757 memcpy(c->u.a.message + c->u.a.lensofar,
4761 c->u.a.lensofar += l;
4763 if (c->u.a.lensofar == c->u.a.totallen) {
4764 void *reply, *sentreply;
4766 agent_query(c->u.a.message,
4767 c->u.a.totallen, &reply,
4772 /* Fake SSH_AGENT_FAILURE. */
4773 sentreply = "\0\0\0\1\5";
4776 ssh2_add_channel_data(c, sentreply,
4781 sfree(c->u.a.message);
4782 c->u.a.lensofar = 0;
4789 * If we are not buffering too much data,
4790 * enlarge the window again at the remote side.
4792 if (bufsize < OUR_V2_WINSIZE)
4793 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
4795 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4796 ssh_state = SSH_STATE_CLOSED;
4797 logevent("Received disconnect message");
4799 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
4800 continue; /* exit status et al; ignore (FIXME?) */
4801 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4802 unsigned i = ssh2_pkt_getuint32();
4803 struct ssh_channel *c;
4805 c = find234(ssh_channels, &i, ssh_channelfind);
4807 continue; /* nonexistent channel */
4809 if (c->type == CHAN_X11) {
4811 * Remote EOF on an X11 channel means we should
4812 * wrap up and close the channel ourselves.
4814 x11_close(c->u.x11.s);
4816 } else if (c->type == CHAN_AGENT) {
4818 } else if (c->type == CHAN_SOCKDATA) {
4819 pfd_close(c->u.pfd.s);
4822 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4823 unsigned i = ssh2_pkt_getuint32();
4824 struct ssh_channel *c;
4826 c = find234(ssh_channels, &i, ssh_channelfind);
4828 continue; /* nonexistent channel */
4829 /* Do pre-close processing on the channel. */
4831 case CHAN_MAINSESSION:
4832 break; /* nothing to see here, move along */
4834 if (c->u.x11.s != NULL)
4835 x11_close(c->u.x11.s);
4842 if (c->u.pfd.s != NULL)
4843 pfd_close(c->u.pfd.s);
4847 if (c->closes == 0) {
4848 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4849 ssh2_pkt_adduint32(c->remoteid);
4852 del234(ssh_channels, c);
4853 bufchain_clear(&c->v.v2.outbuffer);
4857 * See if that was the last channel left open.
4859 if (count234(ssh_channels) == 0) {
4860 logevent("All channels closed. Disconnecting");
4861 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4862 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4863 ssh2_pkt_addstring("All open channels closed");
4864 ssh2_pkt_addstring("en"); /* language tag */
4866 ssh_state = SSH_STATE_CLOSED;
4869 continue; /* remote sends close; ignore (FIXME) */
4870 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4871 unsigned i = ssh2_pkt_getuint32();
4872 struct ssh_channel *c;
4873 c = find234(ssh_channels, &i, ssh_channelfind);
4875 continue; /* nonexistent channel */
4876 c->v.v2.remwindow += ssh2_pkt_getuint32();
4878 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4879 unsigned i = ssh2_pkt_getuint32();
4880 struct ssh_channel *c;
4881 c = find234(ssh_channels, &i, ssh_channelfind);
4883 continue; /* nonexistent channel */
4884 if (c->type != CHAN_SOCKDATA_DORMANT)
4885 continue; /* dunno why they're confirming this */
4886 c->remoteid = ssh2_pkt_getuint32();
4887 c->type = CHAN_SOCKDATA;
4888 c->v.v2.remwindow = ssh2_pkt_getuint32();
4889 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4890 bufchain_init(&c->v.v2.outbuffer);
4892 pfd_confirm(c->u.pfd.s);
4895 * We have a pending close on this channel,
4896 * which we decided on before the server acked
4897 * the channel open. So now we know the
4898 * remoteid, we can close it again.
4900 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4901 ssh2_pkt_adduint32(c->remoteid);
4904 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
4905 unsigned i = ssh2_pkt_getuint32();
4906 struct ssh_channel *c;
4907 c = find234(ssh_channels, &i, ssh_channelfind);
4909 continue; /* nonexistent channel */
4910 if (c->type != CHAN_SOCKDATA_DORMANT)
4911 continue; /* dunno why they're failing this */
4913 logevent("Forwarded connection refused by server");
4915 pfd_close(c->u.pfd.s);
4917 del234(ssh_channels, c);
4919 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
4923 struct ssh_channel *c;
4924 unsigned remid, winsize, pktsize;
4925 ssh2_pkt_getstring(&type, &typelen);
4926 c = smalloc(sizeof(struct ssh_channel));
4928 remid = ssh2_pkt_getuint32();
4929 winsize = ssh2_pkt_getuint32();
4930 pktsize = ssh2_pkt_getuint32();
4932 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4933 if (!ssh_X11_fwd_enabled)
4934 error = "X11 forwarding is not enabled";
4935 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4937 error = "Unable to open an X11 connection";
4941 } else if (typelen == 15 &&
4942 !memcmp(type, "forwarded-tcpip", 15)) {
4943 struct ssh_rportfwd pf, *realpf;
4946 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
4947 pf.sport = ssh2_pkt_getuint32();
4948 realpf = find234(ssh_rportfwds, &pf, NULL);
4949 if (realpf == NULL) {
4950 error = "Remote port is not recognised";
4952 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
4955 sprintf(buf, "Received remote port open request for %s:%d",
4956 realpf->dhost, realpf->dport);
4959 sprintf(buf, "Port open failed: %s", e);
4961 error = "Port open failed";
4963 logevent("Forwarded port opened successfully");
4964 c->type = CHAN_SOCKDATA;
4967 } else if (typelen == 22 &&
4968 !memcmp(type, "auth-agent@openssh.com", 3)) {
4969 if (!ssh_agentfwd_enabled)
4970 error = "Agent forwarding is not enabled";
4972 c->type = CHAN_AGENT; /* identify channel type */
4973 c->u.a.lensofar = 0;
4976 error = "Unsupported channel type requested";
4979 c->remoteid = remid;
4981 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4982 ssh2_pkt_adduint32(c->remoteid);
4983 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4984 ssh2_pkt_addstring(error);
4985 ssh2_pkt_addstring("en"); /* language tag */
4989 c->localid = alloc_channel_id();
4991 c->v.v2.locwindow = OUR_V2_WINSIZE;
4992 c->v.v2.remwindow = winsize;
4993 c->v.v2.remmaxpkt = pktsize;
4994 bufchain_init(&c->v.v2.outbuffer);
4995 add234(ssh_channels, c);
4996 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4997 ssh2_pkt_adduint32(c->remoteid);
4998 ssh2_pkt_adduint32(c->localid);
4999 ssh2_pkt_adduint32(c->v.v2.locwindow);
5000 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5004 bombout(("Strange packet received: type %d", pktin.type));
5009 * We have spare data. Add it to the channel buffer.
5011 ssh2_add_channel_data(mainchan, in, inlen);
5016 struct ssh_channel *c;
5018 * Try to send data on all channels if we can.
5020 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5021 int bufsize = ssh2_try_send(c);
5024 case CHAN_MAINSESSION:
5025 /* stdin need not receive an unthrottle
5026 * notification since it will be polled */
5029 x11_unthrottle(c->u.x11.s);
5032 /* agent sockets are request/response and need no
5033 * buffer management */
5036 pfd_unthrottle(c->u.pfd.s);
5048 * Handle the top-level SSH2 protocol.
5050 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5052 if (do_ssh2_transport(in, inlen, ispkt) == 0)
5054 do_ssh2_authconn(in, inlen, ispkt);
5058 * Called to set up the connection.
5060 * Returns an error message, or NULL on success.
5062 static char *ssh_init(char *host, int port, char **realhost)
5067 if (crypto_startup() == 0)
5068 return "Microsoft high encryption pack not installed!";
5074 ssh1_throttle_count = 0;
5075 ssh_overall_bufsize = 0;
5076 ssh_fallback_cmd = 0;
5078 p = connect_to_host(host, port, realhost);
5086 * Called to send data down the Telnet connection.
5088 static int ssh_send(char *buf, int len)
5090 if (s == NULL || ssh_protocol == NULL)
5093 ssh_protocol(buf, len, 0);
5095 return ssh_sendbuffer();
5099 * Called to query the current amount of buffered stdin data.
5101 static int ssh_sendbuffer(void)
5105 if (s == NULL || ssh_protocol == NULL)
5109 * If the SSH socket itself has backed up, add the total backup
5110 * size on that to any individual buffer on the stdin channel.
5113 if (ssh_throttled_all)
5114 override_value = ssh_overall_bufsize;
5116 if (ssh_version == 1) {
5117 return override_value;
5118 } else if (ssh_version == 2) {
5119 if (!mainchan || mainchan->closes > 0)
5120 return override_value;
5122 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5129 * Called to set the size of the window from SSH's POV.
5131 static void ssh_size(void)
5133 switch (ssh_state) {
5134 case SSH_STATE_BEFORE_SIZE:
5135 case SSH_STATE_PREPACKET:
5136 case SSH_STATE_CLOSED:
5137 break; /* do nothing */
5138 case SSH_STATE_INTERMED:
5139 size_needed = TRUE; /* buffer for later */
5141 case SSH_STATE_SESSION:
5143 if (ssh_version == 1) {
5144 send_packet(SSH1_CMSG_WINDOW_SIZE,
5145 PKT_INT, rows, PKT_INT, cols,
5146 PKT_INT, 0, PKT_INT, 0, PKT_END);
5148 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5149 ssh2_pkt_adduint32(mainchan->remoteid);
5150 ssh2_pkt_addstring("window-change");
5151 ssh2_pkt_addbool(0);
5152 ssh2_pkt_adduint32(cols);
5153 ssh2_pkt_adduint32(rows);
5154 ssh2_pkt_adduint32(0);
5155 ssh2_pkt_adduint32(0);
5164 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5165 * can send an EOF and collect resulting output (e.g. `plink
5168 static void ssh_special(Telnet_Special code)
5170 if (code == TS_EOF) {
5171 if (ssh_state != SSH_STATE_SESSION) {
5173 * Buffer the EOF in case we are pre-SESSION, so we can
5174 * send it as soon as we reach SESSION.
5180 if (ssh_version == 1) {
5181 send_packet(SSH1_CMSG_EOF, PKT_END);
5183 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5184 ssh2_pkt_adduint32(mainchan->remoteid);
5187 logevent("Sent EOF message");
5188 } else if (code == TS_PING) {
5189 if (ssh_state == SSH_STATE_CLOSED
5190 || ssh_state == SSH_STATE_PREPACKET) return;
5191 if (ssh_version == 1) {
5192 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5194 ssh2_pkt_init(SSH2_MSG_IGNORE);
5195 ssh2_pkt_addstring_start();
5203 void *new_sock_channel(Socket s)
5205 struct ssh_channel *c;
5206 c = smalloc(sizeof(struct ssh_channel));
5209 c->remoteid = -1; /* to be set when open confirmed */
5210 c->localid = alloc_channel_id();
5212 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5214 add234(ssh_channels, c);
5220 * This is called when stdout/stderr (the entity to which
5221 * from_backend sends data) manages to clear some backlog.
5223 void ssh_unthrottle(int bufsize)
5225 if (ssh_version == 1) {
5226 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5227 ssh1_stdout_throttling = 0;
5231 if (mainchan && mainchan->closes == 0)
5232 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5236 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5238 struct ssh_channel *c = (struct ssh_channel *)channel;
5241 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5244 if (ssh_version == 1) {
5245 send_packet(SSH1_MSG_PORT_OPEN,
5246 PKT_INT, c->localid,
5249 //PKT_STR, <org:orgport>,
5252 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5253 ssh2_pkt_addstring("direct-tcpip");
5254 ssh2_pkt_adduint32(c->localid);
5255 c->v.v2.locwindow = OUR_V2_WINSIZE;
5256 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5257 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5258 ssh2_pkt_addstring(hostname);
5259 ssh2_pkt_adduint32(port);
5261 * We make up values for the originator data; partly it's
5262 * too much hassle to keep track, and partly I'm not
5263 * convinced the server should be told details like that
5264 * about my local network configuration.
5266 ssh2_pkt_addstring("client-side-connection");
5267 ssh2_pkt_adduint32(0);
5273 static Socket ssh_socket(void)
5278 static int ssh_sendok(void)
5283 static int ssh_ldisc(int option)
5285 if (option == LD_ECHO)
5287 if (option == LD_EDIT)
5292 Backend ssh_backend = {