18 /* uncomment this for packet level debugging */
19 /* #define DUMP_PACKETS */
21 #define logevent(s) { logevent(s); \
22 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
23 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
25 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
26 (s ? sk_close(s), s = NULL : 0), \
27 connection_fatal msg )
29 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
30 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
31 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
32 #define SSH1_CMSG_USER 4 /* 0x4 */
33 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
34 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
35 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
36 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
37 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
38 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
39 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
40 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
41 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
42 #define SSH1_SMSG_FAILURE 15 /* 0xf */
43 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
44 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
45 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
46 #define SSH1_CMSG_EOF 19 /* 0x13 */
47 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
48 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
49 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
50 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
51 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
52 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
53 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
54 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
55 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
56 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
57 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
58 #define SSH1_MSG_IGNORE 32 /* 0x20 */
59 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
60 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
61 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
62 #define SSH1_MSG_DEBUG 36 /* 0x24 */
63 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
64 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
65 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
66 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
67 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
68 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
69 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
71 #define SSH1_AUTH_TIS 5 /* 0x5 */
72 #define SSH1_AUTH_CCARD 16 /* 0x10 */
74 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
75 /* Mask for protoflags we will echo back to server if seen */
76 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
78 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
79 #define SSH2_MSG_IGNORE 2 /* 0x2 */
80 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
81 #define SSH2_MSG_DEBUG 4 /* 0x4 */
82 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
83 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
84 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
85 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
86 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
87 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
88 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
89 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
90 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
91 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
92 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
93 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
94 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
95 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
96 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
97 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
98 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
99 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
100 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
101 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
102 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
103 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
104 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
105 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
106 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
107 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
108 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
109 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
110 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
111 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
112 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
113 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
163 #define GET_32BIT(cp) \
164 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
165 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
166 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
167 ((unsigned long)(unsigned char)(cp)[3]))
169 #define PUT_32BIT(cp, value) { \
170 (cp)[0] = (unsigned char)((value) >> 24); \
171 (cp)[1] = (unsigned char)((value) >> 16); \
172 (cp)[2] = (unsigned char)((value) >> 8); \
173 (cp)[3] = (unsigned char)(value); }
175 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
177 /* Coroutine mechanics for the sillier bits of the code */
178 #define crBegin1 static int crLine = 0;
179 #define crBegin2 switch(crLine) { case 0:;
180 #define crBegin crBegin1; crBegin2;
181 #define crFinish(z) } crLine = 0; return (z)
182 #define crFinishV } crLine = 0; return
183 #define crReturn(z) \
185 crLine=__LINE__; return (z); case __LINE__:;\
189 crLine=__LINE__; return; case __LINE__:;\
191 #define crStop(z) do{ crLine = 0; return (z); }while(0)
192 #define crStopV do{ crLine = 0; return; }while(0)
193 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
194 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
196 extern char *x11_init(Socket *, char *, void *);
197 extern void x11_close(Socket);
198 extern int x11_send(Socket, char *, int);
199 extern void x11_invent_auth(char *, int, char *, int);
200 extern void x11_unthrottle(Socket s);
201 extern void x11_override_throttle(Socket s, int enable);
203 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
204 extern char *pfd_addforward(char *desthost, int destport, int port);
205 extern void pfd_close(Socket s);
206 extern int pfd_send(Socket s, char *data, int len);
207 extern void pfd_confirm(Socket s);
208 extern void pfd_unthrottle(Socket s);
209 extern void pfd_override_throttle(Socket s, int enable);
212 * Buffer management constants. There are several of these for
213 * various different purposes:
215 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
216 * on a local data stream before we throttle the whole SSH
217 * connection (in SSH1 only). Throttling the whole connection is
218 * pretty drastic so we set this high in the hope it won't
221 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
222 * on the SSH connection itself before we defensively throttle
223 * _all_ local data streams. This is pretty drastic too (though
224 * thankfully unlikely in SSH2 since the window mechanism should
225 * ensure that the server never has any need to throttle its end
226 * of the connection), so we set this high as well.
228 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
232 #define SSH1_BUFFER_LIMIT 32768
233 #define SSH_MAX_BACKLOG 32768
234 #define OUR_V2_WINSIZE 16384
237 * Ciphers for SSH2. We miss out single-DES because it isn't
238 * supported; also 3DES and Blowfish are both done differently from
239 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
240 * endianness and different-sized keys.)
242 const static struct ssh2_ciphers *ciphers[] = {
248 const static struct ssh_kex *kex_algs[] = {
249 &ssh_diffiehellman_gex,
253 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
255 static void nullmac_key(unsigned char *key)
258 static void nullmac_generate(unsigned char *blk, int len,
262 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
266 const static struct ssh_mac ssh_mac_none = {
267 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
269 const static struct ssh_mac *macs[] = {
270 &ssh_sha1, &ssh_md5, &ssh_mac_none
272 const static struct ssh_mac *buggymacs[] = {
273 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
276 static void ssh_comp_none_init(void)
279 static int ssh_comp_none_block(unsigned char *block, int len,
280 unsigned char **outblock, int *outlen)
284 static int ssh_comp_none_disable(void)
288 const static struct ssh_compress ssh_comp_none = {
290 ssh_comp_none_init, ssh_comp_none_block,
291 ssh_comp_none_init, ssh_comp_none_block,
292 ssh_comp_none_disable
294 extern const struct ssh_compress ssh_zlib;
295 const static struct ssh_compress *compressions[] = {
296 &ssh_zlib, &ssh_comp_none
299 enum { /* channel types */
304 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
308 * 2-3-4 tree storing channels.
311 unsigned remoteid, localid;
315 struct ssh1_data_channel {
318 struct ssh2_data_channel {
320 unsigned remwindow, remmaxpkt;
325 struct ssh_agent_channel {
326 unsigned char *message;
327 unsigned char msglen[4];
328 int lensofar, totallen;
330 struct ssh_x11_channel {
333 struct ssh_pfd_channel {
340 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
341 * 2 use this structure in different ways, reflecting SSH 2's
342 * altogether saner approach to port forwarding.
344 * In SSH 1, you arrange a remote forwarding by sending the server
345 * the remote port number, and the local destination host:port.
346 * When a connection comes in, the server sends you back that
347 * host:port pair, and you connect to it. This is a ready-made
348 * security hole if you're not on the ball: a malicious server
349 * could send you back _any_ host:port pair, so if you trustingly
350 * connect to the address it gives you then you've just opened the
351 * entire inside of your corporate network just by connecting
352 * through it to a dodgy SSH server. Hence, we must store a list of
353 * host:port pairs we _are_ trying to forward to, and reject a
354 * connection request from the server if it's not in the list.
356 * In SSH 2, each side of the connection minds its own business and
357 * doesn't send unnecessary information to the other. You arrange a
358 * remote forwarding by sending the server just the remote port
359 * number. When a connection comes in, the server tells you which
360 * of its ports was connected to; and _you_ have to remember what
361 * local host:port pair went with that port number.
363 * Hence: in SSH 1 this structure stores host:port pairs we intend
364 * to allow connections to, and is indexed by those host:port
365 * pairs. In SSH 2 it stores a mapping from source port to
366 * destination host:port pair, and is indexed by source port.
368 struct ssh_rportfwd {
369 unsigned sport, dport;
382 static SHA_State exhash, exhashbase;
384 static Socket s = NULL;
386 static unsigned char session_key[32];
387 static int ssh1_compressing;
388 static int ssh1_remote_protoflags;
389 static int ssh1_local_protoflags;
390 static int ssh_agentfwd_enabled;
391 static int ssh_X11_fwd_enabled;
392 static int ssh_remote_bugs;
393 static const struct ssh_cipher *cipher = NULL;
394 static const struct ssh2_cipher *cscipher = NULL;
395 static const struct ssh2_cipher *sccipher = NULL;
396 static const struct ssh_mac *csmac = NULL;
397 static const struct ssh_mac *scmac = NULL;
398 static const struct ssh_compress *cscomp = NULL;
399 static const struct ssh_compress *sccomp = NULL;
400 static const struct ssh_kex *kex = NULL;
401 static const struct ssh_signkey *hostkey = NULL;
402 static unsigned char ssh2_session_id[20];
403 int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
406 static char *savedhost;
407 static int savedport;
408 static int ssh_send_ok;
409 static int ssh_echoing, ssh_editing;
411 static tree234 *ssh_channels; /* indexed by local id */
412 static struct ssh_channel *mainchan; /* primary session channel */
414 static tree234 *ssh_rportfwds;
418 SSH_STATE_BEFORE_SIZE,
422 } ssh_state = SSH_STATE_PREPACKET;
424 static int size_needed = FALSE, eof_needed = FALSE;
426 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
427 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
428 static unsigned char *deferred_send_data = NULL;
429 static int deferred_len = 0, deferred_size = 0;
432 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
433 * that fails. This variable is the means by which scp.c can reach
434 * into the SSH code and find out which one it got.
436 int ssh_fallback_cmd = 0;
438 static int ssh_version;
439 static int ssh1_throttle_count;
440 static int ssh_overall_bufsize;
441 static int ssh_throttled_all;
442 static int ssh1_stdout_throttling;
443 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
444 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
445 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
446 static void ssh_size(void);
447 static void ssh_special(Telnet_Special);
448 static int ssh2_try_send(struct ssh_channel *c);
449 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
451 static void ssh_throttle_all(int enable, int bufsize);
452 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
453 static int (*s_rdpkt) (unsigned char **data, int *datalen);
454 static int ssh_sendbuffer(void);
456 static struct rdpkt1_state_tag {
457 long len, pad, biglen, to_read;
458 unsigned long realcrc, gotcrc;
464 static struct rdpkt2_state_tag {
465 long len, pad, payload, packetlen, maclen;
468 unsigned long incoming_sequence;
471 static int ssh_channelcmp(void *av, void *bv)
473 struct ssh_channel *a = (struct ssh_channel *) av;
474 struct ssh_channel *b = (struct ssh_channel *) bv;
475 if (a->localid < b->localid)
477 if (a->localid > b->localid)
481 static int ssh_channelfind(void *av, void *bv)
483 unsigned *a = (unsigned *) av;
484 struct ssh_channel *b = (struct ssh_channel *) bv;
492 static int ssh_rportcmp_ssh1(void *av, void *bv)
494 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
495 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
497 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
498 return i < 0 ? -1 : +1;
499 if (a->dport > b->dport)
501 if (a->dport < b->dport)
506 static int ssh_rportcmp_ssh2(void *av, void *bv)
508 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
509 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
511 if (a->sport > b->sport)
513 if (a->sport < b->sport)
518 static int alloc_channel_id(void)
520 const unsigned CHANNEL_NUMBER_OFFSET = 256;
521 unsigned low, high, mid;
523 struct ssh_channel *c;
526 * First-fit allocation of channel numbers: always pick the
527 * lowest unused one. To do this, binary-search using the
528 * counted B-tree to find the largest channel ID which is in a
529 * contiguous sequence from the beginning. (Precisely
530 * everything in that sequence must have ID equal to its tree
531 * index plus CHANNEL_NUMBER_OFFSET.)
533 tsize = count234(ssh_channels);
537 while (high - low > 1) {
538 mid = (high + low) / 2;
539 c = index234(ssh_channels, mid);
540 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
541 low = mid; /* this one is fine */
543 high = mid; /* this one is past it */
546 * Now low points to either -1, or the tree index of the
547 * largest ID in the initial sequence.
550 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
551 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
553 return low + 1 + CHANNEL_NUMBER_OFFSET;
556 static void c_write(char *buf, int len)
558 if ((flags & FLAG_STDERR)) {
560 for (i = 0; i < len; i++)
562 fputc(buf[i], stderr);
565 from_backend(1, buf, len);
568 static void c_write_untrusted(char *buf, int len)
571 for (i = 0; i < len; i++) {
574 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
579 static void c_write_str(char *buf)
581 c_write(buf, strlen(buf));
585 * Collect incoming data in the incoming packet buffer.
586 * Decipher and verify the packet when it is completely read.
587 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
588 * Update the *data and *datalen variables.
589 * Return the additional nr of bytes needed, or 0 when
590 * a complete packet is available.
592 static int ssh1_rdpkt(unsigned char **data, int *datalen)
594 struct rdpkt1_state_tag *st = &rdpkt1_state;
603 for (st->i = st->len = 0; st->i < 4; st->i++) {
604 while ((*datalen) == 0)
606 st->len = (st->len << 8) + **data;
607 (*data)++, (*datalen)--;
610 st->pad = 8 - (st->len % 8);
611 st->biglen = st->len + st->pad;
612 pktin.length = st->len - 5;
614 if (pktin.maxlen < st->biglen) {
615 pktin.maxlen = st->biglen;
616 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
617 srealloc(pktin.data, st->biglen + APIEXTRA));
619 fatalbox("Out of memory");
622 st->to_read = st->biglen;
624 while (st->to_read > 0) {
625 st->chunk = st->to_read;
626 while ((*datalen) == 0)
627 crReturn(st->to_read);
628 if (st->chunk > (*datalen))
629 st->chunk = (*datalen);
630 memcpy(st->p, *data, st->chunk);
632 *datalen -= st->chunk;
634 st->to_read -= st->chunk;
638 cipher->decrypt(pktin.data, st->biglen);
640 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
641 dmemdump(pktin.data, st->biglen);
644 st->realcrc = crc32(pktin.data, st->biglen - 4);
645 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
646 if (st->gotcrc != st->realcrc) {
647 bombout(("Incorrect CRC received on packet"));
651 pktin.body = pktin.data + st->pad + 1;
653 if (ssh1_compressing) {
654 unsigned char *decompblk;
657 debug(("Packet payload pre-decompression:\n"));
658 dmemdump(pktin.body - 1, pktin.length + 1);
660 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
661 &decompblk, &decomplen);
663 if (pktin.maxlen < st->pad + decomplen) {
664 pktin.maxlen = st->pad + decomplen;
665 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
666 pktin.body = pktin.data + st->pad + 1;
668 fatalbox("Out of memory");
671 memcpy(pktin.body - 1, decompblk, decomplen);
673 pktin.length = decomplen - 1;
675 debug(("Packet payload post-decompression:\n"));
676 dmemdump(pktin.body - 1, pktin.length + 1);
680 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
681 pktin.type == SSH1_SMSG_STDERR_DATA ||
682 pktin.type == SSH1_MSG_DEBUG ||
683 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
684 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
685 long strlen = GET_32BIT(pktin.body);
686 if (strlen + 4 != pktin.length) {
687 bombout(("Received data packet with bogus string length"));
692 pktin.type = pktin.body[-1];
694 if (pktin.type == SSH1_MSG_DEBUG) {
695 /* log debug message */
697 int strlen = GET_32BIT(pktin.body);
698 strcpy(buf, "Remote: ");
701 memcpy(buf + 8, pktin.body + 4, strlen);
702 buf[8 + strlen] = '\0';
705 } else if (pktin.type == SSH1_MSG_IGNORE) {
710 if (pktin.type == SSH1_MSG_DISCONNECT) {
711 /* log reason code in disconnect message */
713 unsigned msglen = GET_32BIT(pktin.body);
715 strcpy(buf, "Remote sent disconnect: ");
716 nowlen = strlen(buf);
717 if (msglen > sizeof(buf) - nowlen - 1)
718 msglen = sizeof(buf) - nowlen - 1;
719 memcpy(buf + nowlen, pktin.body + 4, msglen);
720 buf[nowlen + msglen] = '\0';
722 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
729 static int ssh2_rdpkt(unsigned char **data, int *datalen)
731 struct rdpkt2_state_tag *st = &rdpkt2_state;
739 st->cipherblk = sccipher->blksize;
742 if (st->cipherblk < 8)
745 if (pktin.maxlen < st->cipherblk) {
746 pktin.maxlen = st->cipherblk;
749 NULL ? smalloc(st->cipherblk +
750 APIEXTRA) : srealloc(pktin.data,
754 fatalbox("Out of memory");
758 * Acquire and decrypt the first block of the packet. This will
759 * contain the length and padding details.
761 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
762 while ((*datalen) == 0)
763 crReturn(st->cipherblk - st->i);
764 pktin.data[st->i] = *(*data)++;
769 sccipher->decrypt(pktin.data, st->cipherblk);
772 * Now get the length and padding figures.
774 st->len = GET_32BIT(pktin.data);
775 st->pad = pktin.data[4];
778 * This enables us to deduce the payload length.
780 st->payload = st->len - st->pad - 1;
782 pktin.length = st->payload + 5;
785 * So now we can work out the total packet length.
787 st->packetlen = st->len + 4;
788 st->maclen = scmac ? scmac->len : 0;
791 * Adjust memory allocation if packet is too big.
793 if (pktin.maxlen < st->packetlen + st->maclen) {
794 pktin.maxlen = st->packetlen + st->maclen;
797 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
802 fatalbox("Out of memory");
806 * Read and decrypt the remainder of the packet.
808 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
810 while ((*datalen) == 0)
811 crReturn(st->packetlen + st->maclen - st->i);
812 pktin.data[st->i] = *(*data)++;
815 /* Decrypt everything _except_ the MAC. */
817 sccipher->decrypt(pktin.data + st->cipherblk,
818 st->packetlen - st->cipherblk);
821 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
822 dmemdump(pktin.data, st->packetlen);
829 && !scmac->verify(pktin.data, st->len + 4,
830 st->incoming_sequence)) {
831 bombout(("Incorrect MAC received on packet"));
834 st->incoming_sequence++; /* whether or not we MACed */
837 * Decompress packet payload.
840 unsigned char *newpayload;
842 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
843 &newpayload, &newlen)) {
844 if (pktin.maxlen < newlen + 5) {
845 pktin.maxlen = newlen + 5;
848 NULL ? smalloc(pktin.maxlen +
849 APIEXTRA) : srealloc(pktin.data,
853 fatalbox("Out of memory");
855 pktin.length = 5 + newlen;
856 memcpy(pktin.data + 5, newpayload, newlen);
858 debug(("Post-decompression payload:\n"));
859 dmemdump(pktin.data + 5, newlen);
867 pktin.type = pktin.data[5];
869 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
870 goto next_packet; /* FIXME: print DEBUG message */
872 if (pktin.type == SSH2_MSG_DISCONNECT) {
873 /* log reason code in disconnect message */
875 int reason = GET_32BIT(pktin.data + 6);
876 unsigned msglen = GET_32BIT(pktin.data + 10);
878 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
879 sprintf(buf, "Received disconnect message (%s)",
880 ssh2_disconnect_reasons[reason]);
882 sprintf(buf, "Received disconnect message (unknown type %d)",
886 strcpy(buf, "Disconnection message text: ");
887 nowlen = strlen(buf);
888 if (msglen > sizeof(buf) - nowlen - 1)
889 msglen = sizeof(buf) - nowlen - 1;
890 memcpy(buf + nowlen, pktin.data + 14, msglen);
891 buf[nowlen + msglen] = '\0';
893 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
895 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
896 ssh2_disconnect_reasons[reason] : "unknown",
904 static void ssh1_pktout_size(int len)
908 len += 5; /* type and CRC */
912 pktout.length = len - 5;
913 if (pktout.maxlen < biglen) {
914 pktout.maxlen = biglen;
916 /* Allocate enough buffer space for extra block
917 * for MS CryptEncrypt() */
918 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
919 srealloc(pktout.data, biglen + 12));
921 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
922 srealloc(pktout.data, biglen + 4));
925 fatalbox("Out of memory");
927 pktout.body = pktout.data + 4 + pad + 1;
930 static void s_wrpkt_start(int type, int len)
932 ssh1_pktout_size(len);
936 static int s_wrpkt_prepare(void)
938 int pad, len, biglen, i;
941 pktout.body[-1] = pktout.type;
944 debug(("Packet payload pre-compression:\n"));
945 dmemdump(pktout.body - 1, pktout.length + 1);
948 if (ssh1_compressing) {
949 unsigned char *compblk;
951 zlib_compress_block(pktout.body - 1, pktout.length + 1,
953 ssh1_pktout_size(complen - 1);
954 memcpy(pktout.body - 1, compblk, complen);
957 debug(("Packet payload post-compression:\n"));
958 dmemdump(pktout.body - 1, pktout.length + 1);
962 len = pktout.length + 5; /* type and CRC */
966 for (i = 0; i < pad; i++)
967 pktout.data[i + 4] = random_byte();
968 crc = crc32(pktout.data + 4, biglen - 4);
969 PUT_32BIT(pktout.data + biglen, crc);
970 PUT_32BIT(pktout.data, len);
973 debug(("Sending packet len=%d\n", biglen + 4));
974 dmemdump(pktout.data, biglen + 4);
977 cipher->encrypt(pktout.data + 4, biglen);
982 static void s_wrpkt(void)
985 len = s_wrpkt_prepare();
986 backlog = sk_write(s, pktout.data, len);
987 if (backlog > SSH_MAX_BACKLOG)
988 ssh_throttle_all(1, backlog);
991 static void s_wrpkt_defer(void)
994 len = s_wrpkt_prepare();
995 if (deferred_len + len > deferred_size) {
996 deferred_size = deferred_len + len + 128;
997 deferred_send_data = srealloc(deferred_send_data, deferred_size);
999 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1000 deferred_len += len;
1004 * Construct a packet with the specified contents.
1006 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
1008 unsigned char *p, *argp, argchar;
1009 unsigned long argint;
1010 int pktlen, argtype, arglen;
1014 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1017 (void) va_arg(ap1, int);
1021 (void) va_arg(ap1, char);
1025 (void) va_arg(ap1, unsigned char *);
1026 arglen = va_arg(ap1, int);
1030 argp = va_arg(ap1, unsigned char *);
1031 arglen = strlen(argp);
1032 pktlen += 4 + arglen;
1035 bn = va_arg(ap1, Bignum);
1036 pktlen += ssh1_bignum_length(bn);
1043 s_wrpkt_start(pkttype, pktlen);
1046 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1049 argint = va_arg(ap2, int);
1050 PUT_32BIT(p, argint);
1054 argchar = va_arg(ap2, unsigned char);
1059 argp = va_arg(ap2, unsigned char *);
1060 arglen = va_arg(ap2, int);
1061 memcpy(p, argp, arglen);
1065 argp = va_arg(ap2, unsigned char *);
1066 arglen = strlen(argp);
1067 PUT_32BIT(p, arglen);
1068 memcpy(p + 4, argp, arglen);
1072 bn = va_arg(ap2, Bignum);
1073 p += ssh1_write_bignum(p, bn);
1079 static void send_packet(int pkttype, ...)
1082 va_start(ap1, pkttype);
1083 va_start(ap2, pkttype);
1084 construct_packet(pkttype, ap1, ap2);
1088 static void defer_packet(int pkttype, ...)
1091 va_start(ap1, pkttype);
1092 va_start(ap2, pkttype);
1093 construct_packet(pkttype, ap1, ap2);
1097 static int ssh_versioncmp(char *a, char *b)
1100 unsigned long av, bv;
1102 av = strtoul(a, &ae, 10);
1103 bv = strtoul(b, &be, 10);
1105 return (av < bv ? -1 : +1);
1110 av = strtoul(ae, &ae, 10);
1111 bv = strtoul(be, &be, 10);
1113 return (av < bv ? -1 : +1);
1119 * Utility routines for putting an SSH-protocol `string' and
1120 * `uint32' into a SHA state.
1123 static void sha_string(SHA_State * s, void *str, int len)
1125 unsigned char lenblk[4];
1126 PUT_32BIT(lenblk, len);
1127 SHA_Bytes(s, lenblk, 4);
1128 SHA_Bytes(s, str, len);
1131 static void sha_uint32(SHA_State * s, unsigned i)
1133 unsigned char intblk[4];
1134 PUT_32BIT(intblk, i);
1135 SHA_Bytes(s, intblk, 4);
1139 * SSH2 packet construction functions.
1141 static void ssh2_pkt_ensure(int length)
1143 if (pktout.maxlen < length) {
1144 pktout.maxlen = length + 256;
1147 NULL ? smalloc(pktout.maxlen +
1148 APIEXTRA) : srealloc(pktout.data,
1152 fatalbox("Out of memory");
1155 static void ssh2_pkt_adddata(void *data, int len)
1157 pktout.length += len;
1158 ssh2_pkt_ensure(pktout.length);
1159 memcpy(pktout.data + pktout.length - len, data, len);
1161 static void ssh2_pkt_addbyte(unsigned char byte)
1163 ssh2_pkt_adddata(&byte, 1);
1165 static void ssh2_pkt_init(int pkt_type)
1168 ssh2_pkt_addbyte((unsigned char) pkt_type);
1170 static void ssh2_pkt_addbool(unsigned char value)
1172 ssh2_pkt_adddata(&value, 1);
1174 static void ssh2_pkt_adduint32(unsigned long value)
1177 PUT_32BIT(x, value);
1178 ssh2_pkt_adddata(x, 4);
1180 static void ssh2_pkt_addstring_start(void)
1182 ssh2_pkt_adduint32(0);
1183 pktout.savedpos = pktout.length;
1185 static void ssh2_pkt_addstring_str(char *data)
1187 ssh2_pkt_adddata(data, strlen(data));
1188 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1189 pktout.length - pktout.savedpos);
1191 static void ssh2_pkt_addstring_data(char *data, int len)
1193 ssh2_pkt_adddata(data, len);
1194 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1195 pktout.length - pktout.savedpos);
1197 static void ssh2_pkt_addstring(char *data)
1199 ssh2_pkt_addstring_start();
1200 ssh2_pkt_addstring_str(data);
1202 static char *ssh2_mpint_fmt(Bignum b, int *len)
1205 int i, n = (bignum_bitcount(b) + 7) / 8;
1208 fatalbox("out of memory");
1210 for (i = 1; i <= n; i++)
1211 p[i] = bignum_byte(b, n - i);
1213 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1215 memmove(p, p + i, n + 1 - i);
1219 static void ssh2_pkt_addmp(Bignum b)
1223 p = ssh2_mpint_fmt(b, &len);
1224 ssh2_pkt_addstring_start();
1225 ssh2_pkt_addstring_data(p, len);
1230 * Construct an SSH2 final-form packet: compress it, encrypt it,
1231 * put the MAC on it. Final packet, ready to be sent, is stored in
1232 * pktout.data. Total length is returned.
1234 static int ssh2_pkt_construct(void)
1236 int cipherblk, maclen, padding, i;
1237 static unsigned long outgoing_sequence = 0;
1240 * Compress packet payload.
1243 debug(("Pre-compression payload:\n"));
1244 dmemdump(pktout.data + 5, pktout.length - 5);
1247 unsigned char *newpayload;
1249 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1250 &newpayload, &newlen)) {
1252 ssh2_pkt_adddata(newpayload, newlen);
1258 * Add padding. At least four bytes, and must also bring total
1259 * length (minus MAC) up to a multiple of the block size.
1261 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1262 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1265 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1266 maclen = csmac ? csmac->len : 0;
1267 ssh2_pkt_ensure(pktout.length + padding + maclen);
1268 pktout.data[4] = padding;
1269 for (i = 0; i < padding; i++)
1270 pktout.data[pktout.length + i] = random_byte();
1271 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1273 csmac->generate(pktout.data, pktout.length + padding,
1275 outgoing_sequence++; /* whether or not we MACed */
1278 debug(("Sending packet len=%d\n", pktout.length + padding));
1279 dmemdump(pktout.data, pktout.length + padding);
1283 cscipher->encrypt(pktout.data, pktout.length + padding);
1285 /* Ready-to-send packet starts at pktout.data. We return length. */
1286 return pktout.length + padding + maclen;
1290 * Construct and send an SSH2 packet immediately.
1292 static void ssh2_pkt_send(void)
1296 len = ssh2_pkt_construct();
1297 backlog = sk_write(s, pktout.data, len);
1298 if (backlog > SSH_MAX_BACKLOG)
1299 ssh_throttle_all(1, backlog);
1303 * Construct an SSH2 packet and add it to a deferred data block.
1304 * Useful for sending multiple packets in a single sk_write() call,
1305 * to prevent a traffic-analysing listener from being able to work
1306 * out the length of any particular packet (such as the password
1309 * Note that because SSH2 sequence-numbers its packets, this can
1310 * NOT be used as an m4-style `defer' allowing packets to be
1311 * constructed in one order and sent in another.
1313 static void ssh2_pkt_defer(void)
1315 int len = ssh2_pkt_construct();
1316 if (deferred_len + len > deferred_size) {
1317 deferred_size = deferred_len + len + 128;
1318 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1320 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1321 deferred_len += len;
1325 * Send the whole deferred data block constructed by
1326 * ssh2_pkt_defer() or SSH1's defer_packet().
1328 static void ssh_pkt_defersend(void)
1331 backlog = sk_write(s, deferred_send_data, deferred_len);
1332 deferred_len = deferred_size = 0;
1333 sfree(deferred_send_data);
1334 deferred_send_data = NULL;
1335 if (backlog > SSH_MAX_BACKLOG)
1336 ssh_throttle_all(1, backlog);
1340 void bndebug(char *string, Bignum b)
1344 p = ssh2_mpint_fmt(b, &len);
1345 debug(("%s", string));
1346 for (i = 0; i < len; i++)
1347 debug((" %02x", p[i]));
1353 static void sha_mpint(SHA_State * s, Bignum b)
1357 p = ssh2_mpint_fmt(b, &len);
1358 sha_string(s, p, len);
1363 * SSH2 packet decode functions.
1365 static unsigned long ssh2_pkt_getuint32(void)
1367 unsigned long value;
1368 if (pktin.length - pktin.savedpos < 4)
1369 return 0; /* arrgh, no way to decline (FIXME?) */
1370 value = GET_32BIT(pktin.data + pktin.savedpos);
1371 pktin.savedpos += 4;
1374 static int ssh2_pkt_getbool(void)
1376 unsigned long value;
1377 if (pktin.length - pktin.savedpos < 1)
1378 return 0; /* arrgh, no way to decline (FIXME?) */
1379 value = pktin.data[pktin.savedpos] != 0;
1383 static void ssh2_pkt_getstring(char **p, int *length)
1386 if (pktin.length - pktin.savedpos < 4)
1388 *length = GET_32BIT(pktin.data + pktin.savedpos);
1389 pktin.savedpos += 4;
1390 if (pktin.length - pktin.savedpos < *length)
1392 *p = pktin.data + pktin.savedpos;
1393 pktin.savedpos += *length;
1395 static Bignum ssh2_pkt_getmp(void)
1401 ssh2_pkt_getstring(&p, &length);
1405 bombout(("internal error: Can't handle negative mpints"));
1408 b = bignum_from_bytes(p, length);
1413 * Examine the remote side's version string and compare it against
1414 * a list of known buggy implementations.
1416 static void ssh_detect_bugs(char *vstring)
1418 char *imp; /* pointer to implementation part */
1420 imp += strcspn(imp, "-");
1423 imp += strcspn(imp, "-");
1427 ssh_remote_bugs = 0;
1429 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1430 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1431 !strcmp(imp, "1.2.22")) {
1433 * These versions don't support SSH1_MSG_IGNORE, so we have
1434 * to use a different defence against password length
1437 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1438 logevent("We believe remote version has SSH1 ignore bug");
1441 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1442 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1443 !strncmp(imp, "2.1 ", 4)) {
1445 * These versions have the HMAC bug.
1447 ssh_remote_bugs |= BUG_SSH2_HMAC;
1448 logevent("We believe remote version has SSH2 HMAC bug");
1452 static int do_ssh_init(unsigned char c)
1455 static char version[10];
1456 static char *vstring;
1457 static int vstrsize;
1463 /* Search for the string "SSH-" in the input. */
1466 static const int transS[] = { 1, 2, 2, 1 };
1467 static const int transH[] = { 0, 0, 3, 0 };
1468 static const int transminus[] = { 0, 0, 0, -1 };
1479 crReturn(1); /* get another character */
1482 vstring = smalloc(16);
1484 strcpy(vstring, "SSH-");
1488 crReturn(1); /* get another char */
1489 if (vslen >= vstrsize - 1) {
1491 vstring = srealloc(vstring, vstrsize);
1493 vstring[vslen++] = c;
1498 } else if (i < sizeof(version) - 1)
1500 } else if (c == '\n')
1504 ssh_agentfwd_enabled = FALSE;
1505 rdpkt2_state.incoming_sequence = 0;
1508 vlog = smalloc(20 + vslen);
1509 sprintf(vlog, "Server version: %s", vstring);
1510 ssh_detect_bugs(vstring);
1511 vlog[strcspn(vlog, "\r\n")] = '\0';
1516 * Server version "1.99" means we can choose whether we use v1
1517 * or v2 protocol. Choice is based on cfg.sshprot.
1519 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1521 * This is a v2 server. Begin v2 protocol.
1523 char verstring[80], vlog[100];
1524 sprintf(verstring, "SSH-2.0-%s", sshver);
1525 SHA_Init(&exhashbase);
1527 * Hash our version string and their version string.
1529 sha_string(&exhashbase, verstring, strlen(verstring));
1530 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1531 sprintf(vlog, "We claim version: %s", verstring);
1533 strcat(verstring, "\n");
1534 logevent("Using SSH protocol version 2");
1535 sk_write(s, verstring, strlen(verstring));
1536 ssh_protocol = ssh2_protocol;
1538 s_rdpkt = ssh2_rdpkt;
1541 * This is a v1 server. Begin v1 protocol.
1543 char verstring[80], vlog[100];
1544 sprintf(verstring, "SSH-%s-%s",
1545 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1547 sprintf(vlog, "We claim version: %s", verstring);
1549 strcat(verstring, "\n");
1550 logevent("Using SSH protocol version 1");
1551 sk_write(s, verstring, strlen(verstring));
1552 ssh_protocol = ssh1_protocol;
1554 s_rdpkt = ssh1_rdpkt;
1556 ssh_state = SSH_STATE_BEFORE_SIZE;
1563 static void ssh_gotdata(unsigned char *data, int datalen)
1568 * To begin with, feed the characters one by one to the
1569 * protocol initialisation / selection function do_ssh_init().
1570 * When that returns 0, we're done with the initial greeting
1571 * exchange and can move on to packet discipline.
1576 crReturnV; /* more data please */
1577 ret = do_ssh_init(*data);
1585 * We emerge from that loop when the initial negotiation is
1586 * over and we have selected an s_rdpkt function. Now pass
1587 * everything to s_rdpkt, and then pass the resulting packets
1588 * to the proper protocol handler.
1593 while (datalen > 0) {
1594 if (s_rdpkt(&data, &datalen) == 0) {
1595 if (ssh_state == SSH_STATE_CLOSED) {
1598 ssh_protocol(NULL, 0, 1);
1599 if (ssh_state == SSH_STATE_CLOSED) {
1609 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1612 ssh_state = SSH_STATE_CLOSED;
1618 /* A socket error has occurred. */
1619 connection_fatal(error_msg);
1621 /* Otherwise, the remote side closed the connection normally. */
1626 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1628 ssh_gotdata(data, len);
1629 if (ssh_state == SSH_STATE_CLOSED) {
1639 static void ssh_sent(Plug plug, int bufsize)
1642 * If the send backlog on the SSH socket itself clears, we
1643 * should unthrottle the whole world if it was throttled.
1645 if (bufsize < SSH_MAX_BACKLOG)
1646 ssh_throttle_all(0, bufsize);
1650 * Connect to specified host and port.
1651 * Returns an error message, or NULL on success.
1652 * Also places the canonical host name into `realhost'. It must be
1653 * freed by the caller.
1655 static char *connect_to_host(char *host, int port, char **realhost)
1657 static struct plug_function_table fn_table = {
1662 }, *fn_table_ptr = &fn_table;
1671 savedhost = smalloc(1 + strlen(host));
1673 fatalbox("Out of memory");
1674 strcpy(savedhost, host);
1677 port = 22; /* default ssh port */
1692 sprintf(buf, "Looking up host \"%.170s\"", host);
1695 addr = sk_namelookup(host, realhost);
1696 if ((err = sk_addr_error(addr)))
1700 *realhost = strdup(FWhost);
1707 char buf[200], addrbuf[100];
1708 sk_getaddr(addr, addrbuf, 100);
1709 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1712 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1713 if ((err = sk_socket_error(s)))
1717 sk_write(s, "connect ", 8);
1718 sk_write(s, FWhost, strlen(FWhost));
1721 sprintf(buf, " %d\n", FWport);
1722 sk_write(s, buf, strlen(buf));
1730 * Throttle or unthrottle the SSH connection.
1732 static void ssh1_throttle(int adjust)
1734 int old_count = ssh1_throttle_count;
1735 ssh1_throttle_count += adjust;
1736 assert(ssh1_throttle_count >= 0);
1737 if (ssh1_throttle_count && !old_count) {
1738 sk_set_frozen(s, 1);
1739 } else if (!ssh1_throttle_count && old_count) {
1740 sk_set_frozen(s, 0);
1745 * Throttle or unthrottle _all_ local data streams (for when sends
1746 * on the SSH connection itself back up).
1748 static void ssh_throttle_all(int enable, int bufsize)
1751 struct ssh_channel *c;
1753 if (enable == ssh_throttled_all)
1755 ssh_throttled_all = enable;
1756 ssh_overall_bufsize = bufsize;
1759 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
1761 case CHAN_MAINSESSION:
1763 * This is treated separately, outside the switch.
1767 x11_override_throttle(c->u.x11.s, enable);
1770 /* Agent channels require no buffer management. */
1773 pfd_override_throttle(c->u.x11.s, enable);
1780 * Handle the key exchange and user authentication phases.
1782 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1786 static unsigned char *rsabuf, *keystr1, *keystr2;
1787 unsigned char cookie[8];
1788 struct RSAKey servkey, hostkey;
1789 struct MD5Context md5c;
1790 static unsigned long supported_ciphers_mask, supported_auths_mask;
1791 static int tried_publickey;
1792 static int tis_auth_refused, ccard_auth_refused;
1793 static unsigned char session_id[16];
1794 static int cipher_type;
1795 static char username[100];
1802 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1803 bombout(("Public key packet not received"));
1807 logevent("Received public keys");
1809 memcpy(cookie, pktin.body, 8);
1811 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1812 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1815 * Log the host key fingerprint.
1819 logevent("Host key fingerprint is:");
1820 strcpy(logmsg, " ");
1821 hostkey.comment = NULL;
1822 rsa_fingerprint(logmsg + strlen(logmsg),
1823 sizeof(logmsg) - strlen(logmsg), &hostkey);
1827 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1828 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1829 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1831 ssh1_local_protoflags =
1832 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1833 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1836 MD5Update(&md5c, keystr2, hostkey.bytes);
1837 MD5Update(&md5c, keystr1, servkey.bytes);
1838 MD5Update(&md5c, pktin.body, 8);
1839 MD5Final(session_id, &md5c);
1841 for (i = 0; i < 32; i++)
1842 session_key[i] = random_byte();
1844 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1846 rsabuf = smalloc(len);
1848 fatalbox("Out of memory");
1851 * Verify the host key.
1855 * First format the key into a string.
1857 int len = rsastr_len(&hostkey);
1858 char fingerprint[100];
1859 char *keystr = smalloc(len);
1861 fatalbox("Out of memory");
1862 rsastr_fmt(keystr, &hostkey);
1863 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1864 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1869 for (i = 0; i < 32; i++) {
1870 rsabuf[i] = session_key[i];
1872 rsabuf[i] ^= session_id[i];
1875 if (hostkey.bytes > servkey.bytes) {
1876 rsaencrypt(rsabuf, 32, &servkey);
1877 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1879 rsaencrypt(rsabuf, 32, &hostkey);
1880 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1883 logevent("Encrypted session key");
1886 int cipher_chosen = 0, warn = 0;
1887 char *cipher_string = NULL;
1888 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
1889 int next_cipher = cfg.ssh_cipherlist[i];
1890 if (next_cipher == CIPHER_WARN) {
1891 /* If/when we choose a cipher, warn about it */
1893 } else if (next_cipher == CIPHER_AES) {
1894 /* XXX Probably don't need to mention this. */
1895 logevent("AES not supported in SSH1, skipping");
1897 switch (next_cipher) {
1898 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
1899 cipher_string = "3DES"; break;
1900 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
1901 cipher_string = "Blowfish"; break;
1902 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
1903 cipher_string = "single-DES"; break;
1905 if (supported_ciphers_mask & (1 << cipher_type))
1909 if (!cipher_chosen) {
1910 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
1911 bombout(("Server violates SSH 1 protocol by not "
1912 "supporting 3DES encryption"));
1914 /* shouldn't happen */
1915 bombout(("No supported ciphers found"));
1919 /* Warn about chosen cipher if necessary. */
1921 askcipher(cipher_string, 0);
1924 switch (cipher_type) {
1925 case SSH_CIPHER_3DES:
1926 logevent("Using 3DES encryption");
1928 case SSH_CIPHER_DES:
1929 logevent("Using single-DES encryption");
1931 case SSH_CIPHER_BLOWFISH:
1932 logevent("Using Blowfish encryption");
1936 send_packet(SSH1_CMSG_SESSION_KEY,
1937 PKT_CHAR, cipher_type,
1938 PKT_DATA, cookie, 8,
1939 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1940 PKT_DATA, rsabuf, len,
1941 PKT_INT, ssh1_local_protoflags, PKT_END);
1943 logevent("Trying to enable encryption...");
1947 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1948 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
1949 cipher->sesskey(session_key);
1953 if (pktin.type != SSH1_SMSG_SUCCESS) {
1954 bombout(("Encryption not successfully enabled"));
1958 logevent("Successfully started encryption");
1964 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1966 if (!ssh_get_line("login as: ",
1967 username, sizeof(username), FALSE)) {
1969 * get_line failed to get a username.
1972 logevent("No username provided. Abandoning session.");
1973 ssh_state = SSH_STATE_CLOSED;
1977 c_write_str("login as: ");
1980 crWaitUntil(!ispkt);
1982 switch (c = *in++) {
1991 c_write_str("\b \b");
1998 c_write_str("\b \b");
2008 if (((c >= ' ' && c <= '~') ||
2009 ((unsigned char) c >= 160))
2010 && pos < sizeof(username)-1) {
2011 username[pos++] = c;
2017 c_write_str("\r\n");
2018 username[strcspn(username, "\n\r")] = '\0';
2021 strncpy(username, cfg.username, 99);
2022 username[99] = '\0';
2025 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2027 char userlog[22 + sizeof(username)];
2028 sprintf(userlog, "Sent username \"%s\"", username);
2030 if (flags & FLAG_INTERACTIVE &&
2031 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2032 strcat(userlog, "\r\n");
2033 c_write_str(userlog);
2040 tried_publickey = 0;
2041 tis_auth_refused = ccard_auth_refused = 0;
2043 while (pktin.type == SSH1_SMSG_FAILURE) {
2044 static char password[100];
2045 static char prompt[200];
2048 static int pwpkt_type;
2049 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2051 if (agent_exists()) {
2053 * Attempt RSA authentication using Pageant.
2055 static unsigned char request[5], *response, *p;
2056 static int responselen;
2057 static int i, nkeys;
2058 static int authed = FALSE;
2061 logevent("Pageant is running. Requesting keys.");
2063 /* Request the keys held by the agent. */
2064 PUT_32BIT(request, 1);
2065 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2066 agent_query(request, 5, &r, &responselen);
2067 response = (unsigned char *) r;
2068 if (response && responselen >= 5 &&
2069 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2071 nkeys = GET_32BIT(p);
2075 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2078 for (i = 0; i < nkeys; i++) {
2079 static struct RSAKey key;
2080 static Bignum challenge;
2081 static char *commentp;
2082 static int commentlen;
2086 sprintf(buf, "Trying Pageant key #%d", i);
2090 p += ssh1_read_bignum(p, &key.exponent);
2091 p += ssh1_read_bignum(p, &key.modulus);
2092 commentlen = GET_32BIT(p);
2096 send_packet(SSH1_CMSG_AUTH_RSA,
2097 PKT_BIGNUM, key.modulus, PKT_END);
2099 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2100 logevent("Key refused");
2103 logevent("Received RSA challenge");
2104 ssh1_read_bignum(pktin.body, &challenge);
2106 char *agentreq, *q, *ret;
2109 len = 1 + 4; /* message type, bit count */
2110 len += ssh1_bignum_length(key.exponent);
2111 len += ssh1_bignum_length(key.modulus);
2112 len += ssh1_bignum_length(challenge);
2113 len += 16; /* session id */
2114 len += 4; /* response format */
2115 agentreq = smalloc(4 + len);
2116 PUT_32BIT(agentreq, len);
2118 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2119 PUT_32BIT(q, bignum_bitcount(key.modulus));
2121 q += ssh1_write_bignum(q, key.exponent);
2122 q += ssh1_write_bignum(q, key.modulus);
2123 q += ssh1_write_bignum(q, challenge);
2124 memcpy(q, session_id, 16);
2126 PUT_32BIT(q, 1); /* response format */
2127 agent_query(agentreq, len + 4, &vret, &retlen);
2131 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2132 logevent("Sending Pageant's response");
2133 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2134 PKT_DATA, ret + 5, 16,
2138 if (pktin.type == SSH1_SMSG_SUCCESS) {
2140 ("Pageant's response accepted");
2141 if (flags & FLAG_VERBOSE) {
2143 ("Authenticated using RSA key \"");
2144 c_write(commentp, commentlen);
2145 c_write_str("\" from agent\r\n");
2150 ("Pageant's response not accepted");
2153 ("Pageant failed to answer challenge");
2157 logevent("No reply received from Pageant");
2160 freebn(key.exponent);
2161 freebn(key.modulus);
2170 if (*cfg.keyfile && !tried_publickey)
2171 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2173 if (cfg.try_tis_auth &&
2174 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2175 !tis_auth_refused) {
2176 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2177 logevent("Requested TIS authentication");
2178 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2180 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2181 logevent("TIS authentication declined");
2182 if (flags & FLAG_INTERACTIVE)
2183 c_write_str("TIS authentication refused.\r\n");
2184 tis_auth_refused = 1;
2187 int challengelen = ((pktin.body[0] << 24) |
2188 (pktin.body[1] << 16) |
2189 (pktin.body[2] << 8) |
2191 logevent("Received TIS challenge");
2192 if (challengelen > sizeof(prompt) - 1)
2193 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2194 memcpy(prompt, pktin.body + 4, challengelen);
2195 /* Prompt heuristic comes from OpenSSH */
2196 strncpy(prompt + challengelen,
2197 memchr(prompt, '\n', challengelen) ?
2198 "": "\r\nResponse: ",
2199 (sizeof prompt) - challengelen);
2200 prompt[(sizeof prompt) - 1] = '\0';
2203 if (cfg.try_tis_auth &&
2204 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2205 !ccard_auth_refused) {
2206 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2207 logevent("Requested CryptoCard authentication");
2208 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2210 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2211 logevent("CryptoCard authentication declined");
2212 c_write_str("CryptoCard authentication refused.\r\n");
2213 ccard_auth_refused = 1;
2216 int challengelen = ((pktin.body[0] << 24) |
2217 (pktin.body[1] << 16) |
2218 (pktin.body[2] << 8) |
2220 logevent("Received CryptoCard challenge");
2221 if (challengelen > sizeof(prompt) - 1)
2222 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2223 memcpy(prompt, pktin.body + 4, challengelen);
2224 strncpy(prompt + challengelen,
2225 memchr(prompt, '\n', challengelen) ?
2226 "" : "\r\nResponse: ",
2227 sizeof(prompt) - challengelen);
2228 prompt[sizeof(prompt) - 1] = '\0';
2231 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2232 sprintf(prompt, "%.90s@%.90s's password: ",
2233 username, savedhost);
2235 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2236 char *comment = NULL;
2237 if (flags & FLAG_VERBOSE)
2238 c_write_str("Trying public key authentication.\r\n");
2239 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2240 if (flags & FLAG_VERBOSE)
2241 c_write_str("No passphrase required.\r\n");
2244 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2249 * Show password prompt, having first obtained it via a TIS
2250 * or CryptoCard exchange if we're doing TIS or CryptoCard
2254 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2256 * get_line failed to get a password (for example
2257 * because one was supplied on the command line
2258 * which has already failed to work). Terminate.
2260 send_packet(SSH1_MSG_DISCONNECT,
2261 PKT_STR, "No more passwords available to try",
2263 connection_fatal("Unable to authenticate");
2264 ssh_state = SSH_STATE_CLOSED;
2268 /* Prompt may have come from server. We've munged it a bit, so
2269 * we know it to be zero-terminated at least once. */
2270 c_write_untrusted(prompt, strlen(prompt));
2274 crWaitUntil(!ispkt);
2276 switch (c = *in++) {
2297 if (pos < sizeof(password)-1)
2298 password[pos++] = c;
2302 c_write_str("\r\n");
2306 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2308 * Try public key authentication with the specified
2311 static struct RSAKey pubkey;
2312 static Bignum challenge, response;
2314 static unsigned char buffer[32];
2316 tried_publickey = 1;
2317 i = loadrsakey(cfg.keyfile, &pubkey, password);
2319 c_write_str("Couldn't load private key from ");
2320 c_write_str(cfg.keyfile);
2321 c_write_str(".\r\n");
2322 continue; /* go and try password */
2325 c_write_str("Wrong passphrase.\r\n");
2326 tried_publickey = 0;
2327 continue; /* try again */
2331 * Send a public key attempt.
2333 send_packet(SSH1_CMSG_AUTH_RSA,
2334 PKT_BIGNUM, pubkey.modulus, PKT_END);
2337 if (pktin.type == SSH1_SMSG_FAILURE) {
2338 c_write_str("Server refused our public key.\r\n");
2339 continue; /* go and try password */
2341 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2342 bombout(("Bizarre response to offer of public key"));
2345 ssh1_read_bignum(pktin.body, &challenge);
2346 response = rsadecrypt(challenge, &pubkey);
2347 freebn(pubkey.private_exponent); /* burn the evidence */
2349 for (i = 0; i < 32; i++) {
2350 buffer[i] = bignum_byte(response, 31 - i);
2354 MD5Update(&md5c, buffer, 32);
2355 MD5Update(&md5c, session_id, 16);
2356 MD5Final(buffer, &md5c);
2358 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2359 PKT_DATA, buffer, 16, PKT_END);
2362 if (pktin.type == SSH1_SMSG_FAILURE) {
2363 if (flags & FLAG_VERBOSE)
2365 ("Failed to authenticate with our public key.\r\n");
2366 continue; /* go and try password */
2367 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2369 ("Bizarre response to RSA authentication response"));
2373 break; /* we're through! */
2375 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2377 * Defence against traffic analysis: we send a
2378 * whole bunch of packets containing strings of
2379 * different lengths. One of these strings is the
2380 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2381 * The others are all random data in
2382 * SSH1_MSG_IGNORE packets. This way a passive
2383 * listener can't tell which is the password, and
2384 * hence can't deduce the password length.
2386 * Anybody with a password length greater than 16
2387 * bytes is going to have enough entropy in their
2388 * password that a listener won't find it _that_
2389 * much help to know how long it is. So what we'll
2392 * - if password length < 16, we send 15 packets
2393 * containing string lengths 1 through 15
2395 * - otherwise, we let N be the nearest multiple
2396 * of 8 below the password length, and send 8
2397 * packets containing string lengths N through
2398 * N+7. This won't obscure the order of
2399 * magnitude of the password length, but it will
2400 * introduce a bit of extra uncertainty.
2402 * A few servers (the old 1.2.18 through 1.2.22)
2403 * can't deal with SSH1_MSG_IGNORE. For these
2404 * servers, we need an alternative defence. We make
2405 * use of the fact that the password is interpreted
2406 * as a C string: so we can append a NUL, then some
2409 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2414 len = strlen(password);
2415 if (len < sizeof(string)) {
2417 strcpy(string, password);
2418 len++; /* cover the zero byte */
2419 while (len < sizeof(string)) {
2420 string[len++] = (char) random_byte();
2425 send_packet(pwpkt_type, PKT_INT, len,
2426 PKT_DATA, s, len, PKT_END);
2428 int bottom, top, pwlen, i;
2431 pwlen = strlen(password);
2433 bottom = 0; /* zero length passwords are OK! :-) */
2436 bottom = pwlen & ~7;
2440 assert(pwlen >= bottom && pwlen <= top);
2442 randomstr = smalloc(top + 1);
2444 for (i = bottom; i <= top; i++) {
2446 defer_packet(pwpkt_type, PKT_STR, password,
2449 for (j = 0; j < i; j++) {
2451 randomstr[j] = random_byte();
2452 } while (randomstr[j] == '\0');
2454 randomstr[i] = '\0';
2455 defer_packet(SSH1_MSG_IGNORE,
2456 PKT_STR, randomstr, PKT_END);
2459 ssh_pkt_defersend();
2462 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2465 logevent("Sent password");
2466 memset(password, 0, strlen(password));
2468 if (pktin.type == SSH1_SMSG_FAILURE) {
2469 if (flags & FLAG_VERBOSE)
2470 c_write_str("Access denied\r\n");
2471 logevent("Authentication refused");
2472 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2473 logevent("Received disconnect request");
2474 ssh_state = SSH_STATE_CLOSED;
2476 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2477 bombout(("Strange packet received, type %d", pktin.type));
2482 logevent("Authentication successful");
2487 void sshfwd_close(struct ssh_channel *c)
2489 if (c && !c->closes) {
2490 if (ssh_version == 1) {
2491 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2494 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2495 ssh2_pkt_adduint32(c->remoteid);
2499 if (c->type == CHAN_X11) {
2501 logevent("Forwarded X11 connection terminated");
2502 } else if (c->type == CHAN_SOCKDATA) {
2504 logevent("Forwarded port closed");
2509 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2511 if (ssh_version == 1) {
2512 send_packet(SSH1_MSG_CHANNEL_DATA,
2513 PKT_INT, c->remoteid,
2514 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2516 * In SSH1 we can return 0 here - implying that forwarded
2517 * connections are never individually throttled - because
2518 * the only circumstance that can cause throttling will be
2519 * the whole SSH connection backing up, in which case
2520 * _everything_ will be throttled as a whole.
2524 ssh2_add_channel_data(c, buf, len);
2525 return ssh2_try_send(c);
2529 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2531 if (ssh_version == 1) {
2532 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2533 c->v.v1.throttling = 0;
2537 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2541 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2547 while (!do_ssh1_login(in, inlen, ispkt)) {
2550 if (ssh_state == SSH_STATE_CLOSED)
2553 if (cfg.agentfwd && agent_exists()) {
2554 logevent("Requesting agent forwarding");
2555 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2559 if (pktin.type != SSH1_SMSG_SUCCESS
2560 && pktin.type != SSH1_SMSG_FAILURE) {
2561 bombout(("Protocol confusion"));
2563 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2564 logevent("Agent forwarding refused");
2566 logevent("Agent forwarding enabled");
2567 ssh_agentfwd_enabled = TRUE;
2571 if (cfg.x11_forward) {
2572 char proto[20], data[64];
2573 logevent("Requesting X11 forwarding");
2574 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2575 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2576 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2577 PKT_STR, proto, PKT_STR, data,
2578 PKT_INT, 0, PKT_END);
2580 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2581 PKT_STR, proto, PKT_STR, data, PKT_END);
2586 if (pktin.type != SSH1_SMSG_SUCCESS
2587 && pktin.type != SSH1_SMSG_FAILURE) {
2588 bombout(("Protocol confusion"));
2590 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2591 logevent("X11 forwarding refused");
2593 logevent("X11 forwarding enabled");
2594 ssh_X11_fwd_enabled = TRUE;
2602 char sports[256], dports[256], host[256];
2605 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2606 /* Add port forwardings. */
2611 while (*e && *e != '\t')
2617 while (*e && *e != ':')
2627 dport = atoi(dports);
2628 sport = atoi(sports);
2629 if (sport && dport) {
2631 pfd_addforward(host, dport, sport);
2632 sprintf(buf, "Local port %d forwarding to %s:%d",
2633 sport, host, dport);
2636 struct ssh_rportfwd *pf;
2637 pf = smalloc(sizeof(*pf));
2638 strcpy(pf->dhost, host);
2640 if (add234(ssh_rportfwds, pf) != pf) {
2642 "Duplicate remote port forwarding to %s:%d",
2647 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2648 sport, host, dport);
2650 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2662 send_packet(SSH1_CMSG_REQUEST_PTY,
2663 PKT_STR, cfg.termtype,
2664 PKT_INT, rows, PKT_INT, cols,
2665 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2666 ssh_state = SSH_STATE_INTERMED;
2670 if (pktin.type != SSH1_SMSG_SUCCESS
2671 && pktin.type != SSH1_SMSG_FAILURE) {
2672 bombout(("Protocol confusion"));
2674 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2675 c_write_str("Server refused to allocate pty\r\n");
2676 ssh_editing = ssh_echoing = 1;
2678 logevent("Allocated pty");
2680 ssh_editing = ssh_echoing = 1;
2683 if (cfg.compression) {
2684 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2688 if (pktin.type != SSH1_SMSG_SUCCESS
2689 && pktin.type != SSH1_SMSG_FAILURE) {
2690 bombout(("Protocol confusion"));
2692 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2693 c_write_str("Server refused to compress\r\n");
2695 logevent("Started compression");
2696 ssh1_compressing = TRUE;
2697 zlib_compress_init();
2698 zlib_decompress_init();
2702 * Start the shell or command.
2704 * Special case: if the first-choice command is an SSH2
2705 * subsystem (hence not usable here) and the second choice
2706 * exists, we fall straight back to that.
2709 char *cmd = cfg.remote_cmd_ptr;
2711 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
2712 cmd = cfg.remote_cmd_ptr2;
2713 ssh_fallback_cmd = TRUE;
2716 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2718 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2719 logevent("Started session");
2722 ssh_state = SSH_STATE_SESSION;
2726 ssh_special(TS_EOF);
2728 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
2730 ssh_channels = newtree234(ssh_channelcmp);
2734 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2735 pktin.type == SSH1_SMSG_STDERR_DATA) {
2736 long len = GET_32BIT(pktin.body);
2738 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2739 pktin.body + 4, len);
2740 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
2741 ssh1_stdout_throttling = 1;
2744 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2745 ssh_state = SSH_STATE_CLOSED;
2746 logevent("Received disconnect request");
2748 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2749 /* Remote side is trying to open a channel to talk to our
2750 * X-Server. Give them back a local channel number. */
2751 struct ssh_channel *c;
2753 logevent("Received X11 connect request");
2754 /* Refuse if X11 forwarding is disabled. */
2755 if (!ssh_X11_fwd_enabled) {
2756 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2757 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2758 logevent("Rejected X11 connect request");
2760 c = smalloc(sizeof(struct ssh_channel));
2762 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2763 logevent("opening X11 forward connection failed");
2765 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2766 PKT_INT, GET_32BIT(pktin.body),
2770 ("opening X11 forward connection succeeded");
2771 c->remoteid = GET_32BIT(pktin.body);
2772 c->localid = alloc_channel_id();
2774 c->v.v1.throttling = 0;
2775 c->type = CHAN_X11; /* identify channel type */
2776 add234(ssh_channels, c);
2777 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2778 PKT_INT, c->remoteid, PKT_INT,
2779 c->localid, PKT_END);
2780 logevent("Opened X11 forward channel");
2783 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2784 /* Remote side is trying to open a channel to talk to our
2785 * agent. Give them back a local channel number. */
2786 struct ssh_channel *c;
2788 /* Refuse if agent forwarding is disabled. */
2789 if (!ssh_agentfwd_enabled) {
2790 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2791 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2793 c = smalloc(sizeof(struct ssh_channel));
2794 c->remoteid = GET_32BIT(pktin.body);
2795 c->localid = alloc_channel_id();
2797 c->v.v1.throttling = 0;
2798 c->type = CHAN_AGENT; /* identify channel type */
2799 c->u.a.lensofar = 0;
2800 add234(ssh_channels, c);
2801 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2802 PKT_INT, c->remoteid, PKT_INT, c->localid,
2805 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2806 /* Remote side is trying to open a channel to talk to a
2807 * forwarded port. Give them back a local channel number. */
2808 struct ssh_channel *c;
2809 struct ssh_rportfwd pf;
2811 char host[256], buf[1024];
2813 c = smalloc(sizeof(struct ssh_channel));
2815 hostsize = GET_32BIT(pktin.body+4);
2816 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2817 if (h+1 < host+sizeof(host))
2822 port = GET_32BIT(p);
2824 strcpy(pf.dhost, host);
2827 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2828 sprintf(buf, "Rejected remote port open request for %s:%d",
2831 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2832 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2834 sprintf(buf, "Received remote port open request for %s:%d",
2837 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2840 sprintf(buf, "Port open failed: %s", e);
2843 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2844 PKT_INT, GET_32BIT(pktin.body),
2847 c->remoteid = GET_32BIT(pktin.body);
2848 c->localid = alloc_channel_id();
2850 c->v.v1.throttling = 0;
2851 c->type = CHAN_SOCKDATA; /* identify channel type */
2852 add234(ssh_channels, c);
2853 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2854 PKT_INT, c->remoteid, PKT_INT,
2855 c->localid, PKT_END);
2856 logevent("Forwarded port opened successfully");
2860 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
2861 unsigned int remoteid = GET_32BIT(pktin.body);
2862 unsigned int localid = GET_32BIT(pktin.body+4);
2863 struct ssh_channel *c;
2865 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2866 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2867 c->remoteid = localid;
2868 c->type = CHAN_SOCKDATA;
2869 pfd_confirm(c->u.pfd.s);
2872 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
2873 unsigned int remoteid = GET_32BIT(pktin.body);
2874 unsigned int localid = GET_32BIT(pktin.body+4);
2875 struct ssh_channel *c;
2877 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2878 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2879 logevent("Forwarded connection refused by server");
2880 pfd_close(c->u.pfd.s);
2881 del234(ssh_channels, c);
2885 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2886 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2887 /* Remote side closes a channel. */
2888 unsigned i = GET_32BIT(pktin.body);
2889 struct ssh_channel *c;
2890 c = find234(ssh_channels, &i, ssh_channelfind);
2894 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2895 if (!(c->closes & closetype))
2896 send_packet(pktin.type, PKT_INT, c->remoteid,
2898 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2899 logevent("Forwarded X11 connection terminated");
2900 assert(c->u.x11.s != NULL);
2901 x11_close(c->u.x11.s);
2904 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
2905 logevent("Forwarded port closed");
2906 assert(c->u.pfd.s != NULL);
2907 pfd_close(c->u.pfd.s);
2910 c->closes |= closetype;
2911 if (c->closes == 3) {
2912 del234(ssh_channels, c);
2916 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2917 /* Data sent down one of our channels. */
2918 int i = GET_32BIT(pktin.body);
2919 int len = GET_32BIT(pktin.body + 4);
2920 unsigned char *p = pktin.body + 8;
2921 struct ssh_channel *c;
2922 c = find234(ssh_channels, &i, ssh_channelfind);
2927 bufsize = x11_send(c->u.x11.s, p, len);
2930 bufsize = pfd_send(c->u.pfd.s, p, len);
2933 /* Data for an agent message. Buffer it. */
2935 if (c->u.a.lensofar < 4) {
2936 int l = min(4 - c->u.a.lensofar, len);
2937 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2941 c->u.a.lensofar += l;
2943 if (c->u.a.lensofar == 4) {
2945 4 + GET_32BIT(c->u.a.msglen);
2946 c->u.a.message = smalloc(c->u.a.totallen);
2947 memcpy(c->u.a.message, c->u.a.msglen, 4);
2949 if (c->u.a.lensofar >= 4 && len > 0) {
2951 min(c->u.a.totallen - c->u.a.lensofar,
2953 memcpy(c->u.a.message + c->u.a.lensofar, p,
2957 c->u.a.lensofar += l;
2959 if (c->u.a.lensofar == c->u.a.totallen) {
2960 void *reply, *sentreply;
2962 agent_query(c->u.a.message,
2963 c->u.a.totallen, &reply,
2968 /* Fake SSH_AGENT_FAILURE. */
2969 sentreply = "\0\0\0\1\5";
2972 send_packet(SSH1_MSG_CHANNEL_DATA,
2973 PKT_INT, c->remoteid,
2975 PKT_DATA, sentreply, replylen,
2979 sfree(c->u.a.message);
2980 c->u.a.lensofar = 0;
2983 bufsize = 0; /* agent channels never back up */
2986 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
2987 c->v.v1.throttling = 1;
2991 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2992 /* may be from EXEC_SHELL on some servers */
2993 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2994 /* may be from EXEC_SHELL on some servers
2995 * if no pty is available or in other odd cases. Ignore */
2996 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2997 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2999 * In case `helpful' firewalls or proxies tack
3000 * extra human-readable text on the end of the
3001 * session which we might mistake for another
3002 * encrypted packet, we close the session once
3003 * we've sent EXIT_CONFIRMATION.
3005 ssh_state = SSH_STATE_CLOSED;
3008 bombout(("Strange packet received: type %d", pktin.type));
3013 int len = min(inlen, 512);
3014 send_packet(SSH1_CMSG_STDIN_DATA,
3015 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3026 * Utility routine for decoding comma-separated strings in KEXINIT.
3028 static int in_commasep_string(char *needle, char *haystack, int haylen)
3030 int needlen = strlen(needle);
3033 * Is it at the start of the string?
3035 if (haylen >= needlen && /* haystack is long enough */
3036 !memcmp(needle, haystack, needlen) && /* initial match */
3037 (haylen == needlen || haystack[needlen] == ',')
3038 /* either , or EOS follows */
3042 * If not, search for the next comma and resume after that.
3043 * If no comma found, terminate.
3045 while (haylen > 0 && *haystack != ',')
3046 haylen--, haystack++;
3049 haylen--, haystack++; /* skip over comma itself */
3054 * SSH2 key creation method.
3056 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3060 /* First 20 bytes. */
3063 SHA_Bytes(&s, H, 20);
3064 SHA_Bytes(&s, &chr, 1);
3065 SHA_Bytes(&s, sessid, 20);
3066 SHA_Final(&s, keyspace);
3067 /* Next 20 bytes. */
3070 SHA_Bytes(&s, H, 20);
3071 SHA_Bytes(&s, keyspace, 20);
3072 SHA_Final(&s, keyspace + 20);
3076 * Handle the SSH2 transport layer.
3078 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3080 static int i, j, len, nbits, pbits, warn;
3082 static Bignum p, g, e, f, K;
3083 static int kex_init_value, kex_reply_value;
3084 static const struct ssh_mac **maclist;
3086 static const struct ssh2_cipher *cscipher_tobe = NULL;
3087 static const struct ssh2_cipher *sccipher_tobe = NULL;
3088 static const struct ssh_mac *csmac_tobe = NULL;
3089 static const struct ssh_mac *scmac_tobe = NULL;
3090 static const struct ssh_compress *cscomp_tobe = NULL;
3091 static const struct ssh_compress *sccomp_tobe = NULL;
3092 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3093 static int hostkeylen, siglen;
3094 static void *hkey; /* actual host key */
3095 static unsigned char exchange_hash[20];
3096 static unsigned char keyspace[40];
3097 static int n_preferred_ciphers;
3098 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3099 static const struct ssh_compress *preferred_comp;
3100 static int first_kex;
3107 * Set up the preferred ciphers. (NULL => warn below here)
3109 n_preferred_ciphers = 0;
3110 for (i = 0; i < CIPHER_MAX; i++) {
3111 switch (cfg.ssh_cipherlist[i]) {
3112 case CIPHER_BLOWFISH:
3113 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3114 n_preferred_ciphers++;
3117 /* Not supported in SSH2; silently drop */
3120 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3121 n_preferred_ciphers++;
3124 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3125 n_preferred_ciphers++;
3128 /* Flag for later. Don't bother if it's the last in
3130 if (i < CIPHER_MAX - 1) {
3131 preferred_ciphers[n_preferred_ciphers] = NULL;
3132 n_preferred_ciphers++;
3139 * Set up preferred compression.
3141 if (cfg.compression)
3142 preferred_comp = &ssh_zlib;
3144 preferred_comp = &ssh_comp_none;
3147 * Be prepared to work around the buggy MAC problem.
3149 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3150 maclist = buggymacs, nmacs = lenof(buggymacs);
3152 maclist = macs, nmacs = lenof(macs);
3156 * Construct and send our key exchange packet.
3158 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3159 for (i = 0; i < 16; i++)
3160 ssh2_pkt_addbyte((unsigned char) random_byte());
3161 /* List key exchange algorithms. */
3162 ssh2_pkt_addstring_start();
3163 for (i = 0; i < lenof(kex_algs); i++) {
3164 ssh2_pkt_addstring_str(kex_algs[i]->name);
3165 if (i < lenof(kex_algs) - 1)
3166 ssh2_pkt_addstring_str(",");
3168 /* List server host key algorithms. */
3169 ssh2_pkt_addstring_start();
3170 for (i = 0; i < lenof(hostkey_algs); i++) {
3171 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3172 if (i < lenof(hostkey_algs) - 1)
3173 ssh2_pkt_addstring_str(",");
3175 /* List client->server encryption algorithms. */
3176 ssh2_pkt_addstring_start();
3177 for (i = 0; i < n_preferred_ciphers; i++) {
3178 const struct ssh2_ciphers *c = preferred_ciphers[i];
3179 if (!c) continue; /* warning flag */
3180 for (j = 0; j < c->nciphers; j++) {
3181 ssh2_pkt_addstring_str(c->list[j]->name);
3182 if (i < n_preferred_ciphers || j < c->nciphers - 1)
3183 ssh2_pkt_addstring_str(",");
3186 /* List server->client encryption algorithms. */
3187 ssh2_pkt_addstring_start();
3188 for (i = 0; i < n_preferred_ciphers; i++) {
3189 const struct ssh2_ciphers *c = preferred_ciphers[i];
3190 if (!c) continue; /* warning flag */
3191 for (j = 0; j < c->nciphers; j++) {
3192 ssh2_pkt_addstring_str(c->list[j]->name);
3193 if (i < n_preferred_ciphers || j < c->nciphers - 1)
3194 ssh2_pkt_addstring_str(",");
3197 /* List client->server MAC algorithms. */
3198 ssh2_pkt_addstring_start();
3199 for (i = 0; i < nmacs; i++) {
3200 ssh2_pkt_addstring_str(maclist[i]->name);
3202 ssh2_pkt_addstring_str(",");
3204 /* List server->client MAC algorithms. */
3205 ssh2_pkt_addstring_start();
3206 for (i = 0; i < nmacs; i++) {
3207 ssh2_pkt_addstring_str(maclist[i]->name);
3209 ssh2_pkt_addstring_str(",");
3211 /* List client->server compression algorithms. */
3212 ssh2_pkt_addstring_start();
3213 for (i = 0; i < lenof(compressions) + 1; i++) {
3214 const struct ssh_compress *c =
3215 i == 0 ? preferred_comp : compressions[i - 1];
3216 ssh2_pkt_addstring_str(c->name);
3217 if (i < lenof(compressions))
3218 ssh2_pkt_addstring_str(",");
3220 /* List server->client compression algorithms. */
3221 ssh2_pkt_addstring_start();
3222 for (i = 0; i < lenof(compressions) + 1; i++) {
3223 const struct ssh_compress *c =
3224 i == 0 ? preferred_comp : compressions[i - 1];
3225 ssh2_pkt_addstring_str(c->name);
3226 if (i < lenof(compressions))
3227 ssh2_pkt_addstring_str(",");
3229 /* List client->server languages. Empty list. */
3230 ssh2_pkt_addstring_start();
3231 /* List server->client languages. Empty list. */
3232 ssh2_pkt_addstring_start();
3233 /* First KEX packet does _not_ follow, because we're not that brave. */
3234 ssh2_pkt_addbool(FALSE);
3236 ssh2_pkt_adduint32(0);
3238 exhash = exhashbase;
3239 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3245 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3248 * Now examine the other side's KEXINIT to see what we're up
3251 if (pktin.type != SSH2_MSG_KEXINIT) {
3252 bombout(("expected key exchange packet from server"));
3257 cscipher_tobe = NULL;
3258 sccipher_tobe = NULL;
3263 pktin.savedpos += 16; /* skip garbage cookie */
3264 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3265 for (i = 0; i < lenof(kex_algs); i++) {
3266 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3271 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3272 for (i = 0; i < lenof(hostkey_algs); i++) {
3273 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3274 hostkey = hostkey_algs[i];
3278 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3280 for (i = 0; i < n_preferred_ciphers; i++) {
3281 const struct ssh2_ciphers *c = preferred_ciphers[i];
3285 for (j = 0; j < c->nciphers; j++) {
3286 if (in_commasep_string(c->list[j]->name, str, len)) {
3287 cscipher_tobe = c->list[j];
3292 if (cscipher_tobe) {
3294 askcipher(cscipher_tobe->name, 1);
3298 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3300 for (i = 0; i < n_preferred_ciphers; i++) {
3301 const struct ssh2_ciphers *c = preferred_ciphers[i];
3305 for (j = 0; j < c->nciphers; j++) {
3306 if (in_commasep_string(c->list[j]->name, str, len)) {
3307 sccipher_tobe = c->list[j];
3312 if (sccipher_tobe) {
3314 askcipher(sccipher_tobe->name, 2);
3318 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3319 for (i = 0; i < nmacs; i++) {
3320 if (in_commasep_string(maclist[i]->name, str, len)) {
3321 csmac_tobe = maclist[i];
3325 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3326 for (i = 0; i < nmacs; i++) {
3327 if (in_commasep_string(maclist[i]->name, str, len)) {
3328 scmac_tobe = maclist[i];
3332 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3333 for (i = 0; i < lenof(compressions) + 1; i++) {
3334 const struct ssh_compress *c =
3335 i == 0 ? preferred_comp : compressions[i - 1];
3336 if (in_commasep_string(c->name, str, len)) {
3341 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3342 for (i = 0; i < lenof(compressions) + 1; i++) {
3343 const struct ssh_compress *c =
3344 i == 0 ? preferred_comp : compressions[i - 1];
3345 if (in_commasep_string(c->name, str, len)) {
3352 * Work out the number of bits of key we will need from the key
3353 * exchange. We start with the maximum key length of either
3359 csbits = cscipher_tobe->keylen;
3360 scbits = sccipher_tobe->keylen;
3361 nbits = (csbits > scbits ? csbits : scbits);
3363 /* The keys only have 160-bit entropy, since they're based on
3364 * a SHA-1 hash. So cap the key size at 160 bits. */
3369 * If we're doing Diffie-Hellman group exchange, start by
3370 * requesting a group.
3372 if (kex == &ssh_diffiehellman_gex) {
3373 logevent("Doing Diffie-Hellman group exchange");
3375 * Work out how big a DH group we will need to allow that
3378 pbits = 512 << ((nbits - 1) / 64);
3379 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3380 ssh2_pkt_adduint32(pbits);
3384 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3385 bombout(("expected key exchange group packet from server"));
3388 p = ssh2_pkt_getmp();
3389 g = ssh2_pkt_getmp();
3390 dh_setup_group(p, g);
3391 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3392 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3395 kex_init_value = SSH2_MSG_KEXDH_INIT;
3396 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3399 logevent("Doing Diffie-Hellman key exchange");
3401 * Now generate and send e for Diffie-Hellman.
3403 e = dh_create_e(nbits * 2);
3404 ssh2_pkt_init(kex_init_value);
3409 if (pktin.type != kex_reply_value) {
3410 bombout(("expected key exchange reply packet from server"));
3413 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3414 f = ssh2_pkt_getmp();
3415 ssh2_pkt_getstring(&sigdata, &siglen);
3419 sha_string(&exhash, hostkeydata, hostkeylen);
3420 if (kex == &ssh_diffiehellman_gex) {
3421 sha_uint32(&exhash, pbits);
3422 sha_mpint(&exhash, p);
3423 sha_mpint(&exhash, g);
3425 sha_mpint(&exhash, e);
3426 sha_mpint(&exhash, f);
3427 sha_mpint(&exhash, K);
3428 SHA_Final(&exhash, exchange_hash);
3433 debug(("Exchange hash is:\n"));
3434 dmemdump(exchange_hash, 20);
3437 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3439 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3440 bombout(("Server's host key did not match the signature supplied"));
3445 * Expect SSH2_MSG_NEWKEYS from server.
3448 if (pktin.type != SSH2_MSG_NEWKEYS) {
3449 bombout(("expected new-keys packet from server"));
3454 * Authenticate remote host: verify host key. (We've already
3455 * checked the signature of the exchange hash.)
3457 keystr = hostkey->fmtkey(hkey);
3458 fingerprint = hostkey->fingerprint(hkey);
3459 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3460 keystr, fingerprint);
3461 if (first_kex) { /* don't bother logging this in rekeys */
3462 logevent("Host key fingerprint is:");
3463 logevent(fingerprint);
3467 hostkey->freekey(hkey);
3470 * Send SSH2_MSG_NEWKEYS.
3472 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3476 * Create and initialise session keys.
3478 cscipher = cscipher_tobe;
3479 sccipher = sccipher_tobe;
3482 cscomp = cscomp_tobe;
3483 sccomp = sccomp_tobe;
3484 cscomp->compress_init();
3485 sccomp->decompress_init();
3487 * Set IVs after keys. Here we use the exchange hash from the
3488 * _first_ key exchange.
3491 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3492 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3493 cscipher->setcskey(keyspace);
3494 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3495 sccipher->setsckey(keyspace);
3496 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3497 cscipher->setcsiv(keyspace);
3498 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3499 sccipher->setsciv(keyspace);
3500 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3501 csmac->setcskey(keyspace);
3502 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3503 scmac->setsckey(keyspace);
3506 * If this is the first key exchange phase, we must pass the
3507 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3508 * wants to see it but because it will need time to initialise
3509 * itself before it sees an actual packet. In subsequent key
3510 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3511 * it would only confuse the layer above.
3519 * Now we're encrypting. Begin returning 1 to the protocol main
3520 * function so that other things can run on top of the
3521 * transport. If we ever see a KEXINIT, we must go back to the
3524 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3527 logevent("Server initiated key re-exchange");
3528 goto begin_key_exchange;
3534 * Add data to an SSH2 channel output buffer.
3536 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3539 bufchain_add(&c->v.v2.outbuffer, buf, len);
3543 * Attempt to send data on an SSH2 channel.
3545 static int ssh2_try_send(struct ssh_channel *c)
3547 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3550 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3551 if ((unsigned)len > c->v.v2.remwindow)
3552 len = c->v.v2.remwindow;
3553 if ((unsigned)len > c->v.v2.remmaxpkt)
3554 len = c->v.v2.remmaxpkt;
3555 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3556 ssh2_pkt_adduint32(c->remoteid);
3557 ssh2_pkt_addstring_start();
3558 ssh2_pkt_addstring_data(data, len);
3560 bufchain_consume(&c->v.v2.outbuffer, len);
3561 c->v.v2.remwindow -= len;
3565 * After having sent as much data as we can, return the amount
3568 return bufchain_size(&c->v.v2.outbuffer);
3572 * Potentially enlarge the window on an SSH2 channel.
3574 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3576 if (newwin > c->v.v2.locwindow) {
3577 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3578 ssh2_pkt_adduint32(c->remoteid);
3579 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
3581 c->v.v2.locwindow = newwin;
3586 * Handle the SSH2 userauth and connection layers.
3588 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3591 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3593 AUTH_KEYBOARD_INTERACTIVE
3597 AUTH_TYPE_PUBLICKEY,
3598 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3599 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3601 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3602 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3604 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3605 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
3606 static int kbd_inter_running;
3607 static int we_are_in;
3608 static int num_prompts, echo;
3609 static char username[100];
3610 static char pwprompt[200];
3611 static char password[100];
3616 * Request userauth protocol, and await a response to it.
3618 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3619 ssh2_pkt_addstring("ssh-userauth");
3621 crWaitUntilV(ispkt);
3622 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3623 bombout(("Server refused user authentication protocol"));
3628 * We repeat this whole loop, including the username prompt,
3629 * until we manage a successful authentication. If the user
3630 * types the wrong _password_, they are sent back to the
3631 * beginning to try another username. (If they specify a
3632 * username in the config, they are never asked, even if they
3633 * do give a wrong password.)
3635 * I think this best serves the needs of
3637 * - the people who have no configuration, no keys, and just
3638 * want to try repeated (username,password) pairs until they
3639 * type both correctly
3641 * - people who have keys and configuration but occasionally
3642 * need to fall back to passwords
3644 * - people with a key held in Pageant, who might not have
3645 * logged in to a particular machine before; so they want to
3646 * type a username, and then _either_ their key will be
3647 * accepted, _or_ they will type a password. If they mistype
3648 * the username they will want to be able to get back and
3659 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3661 if (!ssh_get_line("login as: ",
3662 username, sizeof(username), FALSE)) {
3664 * get_line failed to get a username.
3667 logevent("No username provided. Abandoning session.");
3668 ssh_state = SSH_STATE_CLOSED;
3672 c_write_str("login as: ");
3675 crWaitUntilV(!ispkt);
3677 switch (c = *in++) {
3686 c_write_str("\b \b");
3693 c_write_str("\b \b");
3703 if (((c >= ' ' && c <= '~') ||
3704 ((unsigned char) c >= 160))
3705 && pos < sizeof(username)-1) {
3706 username[pos++] = c;
3713 c_write_str("\r\n");
3714 username[strcspn(username, "\n\r")] = '\0';
3717 strncpy(username, cfg.username, 99);
3718 username[99] = '\0';
3719 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3720 sprintf(stuff, "Using username \"%s\".\r\n", username);
3726 * Send an authentication request using method "none": (a)
3727 * just in case it succeeds, and (b) so that we know what
3728 * authentication methods we can usefully try next.
3730 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3731 ssh2_pkt_addstring(username);
3732 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3733 ssh2_pkt_addstring("none"); /* method */
3735 type = AUTH_TYPE_NONE;
3739 tried_pubkey_config = FALSE;
3740 tried_agent = FALSE;
3741 tried_keyb_inter = FALSE;
3742 kbd_inter_running = FALSE;
3746 * Wait for the result of the last authentication request.
3749 crWaitUntilV(ispkt);
3750 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3754 * Don't show the banner if we're operating in
3755 * non-verbose non-interactive mode. (It's probably
3756 * a script, which means nobody will read the
3757 * banner _anyway_, and moreover the printing of
3758 * the banner will screw up processing on the
3759 * output of (say) plink.)
3761 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3762 ssh2_pkt_getstring(&banner, &size);
3764 c_write_untrusted(banner, size);
3766 crWaitUntilV(ispkt);
3768 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3769 logevent("Access granted");
3774 if (kbd_inter_running &&
3775 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
3777 * This is a further prompt in keyboard-interactive
3778 * authentication. Do nothing.
3780 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3781 bombout(("Strange packet received during authentication: type %d",
3789 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3790 * we can look at the string in it and know what we can
3791 * helpfully try next.
3793 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
3796 ssh2_pkt_getstring(&methods, &methlen);
3797 kbd_inter_running = FALSE;
3798 if (!ssh2_pkt_getbool()) {
3800 * We have received an unequivocal Access
3801 * Denied. This can translate to a variety of
3804 * - if we'd just tried "none" authentication,
3805 * it's not worth printing anything at all
3807 * - if we'd just tried a public key _offer_,
3808 * the message should be "Server refused our
3809 * key" (or no message at all if the key
3810 * came from Pageant)
3812 * - if we'd just tried anything else, the
3813 * message really should be "Access denied".
3815 * Additionally, if we'd just tried password
3816 * authentication, we should break out of this
3817 * whole loop so as to go back to the username
3820 if (type == AUTH_TYPE_NONE) {
3822 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3823 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3824 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3825 c_write_str("Server refused our key\r\n");
3826 logevent("Server refused public key");
3827 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
3828 /* server declined keyboard-interactive; ignore */
3830 c_write_str("Access denied\r\n");
3831 logevent("Access denied");
3832 if (type == AUTH_TYPE_PASSWORD) {
3838 c_write_str("Further authentication required\r\n");
3839 logevent("Further authentication required");
3843 in_commasep_string("publickey", methods, methlen);
3845 in_commasep_string("password", methods, methlen);
3847 in_commasep_string("keyboard-interactive", methods, methlen);
3852 if (!method && can_pubkey && agent_exists() && !tried_agent) {
3854 * Attempt public-key authentication using Pageant.
3856 static unsigned char request[5], *response, *p;
3857 static int responselen;
3858 static int i, nkeys;
3859 static int authed = FALSE;
3864 logevent("Pageant is running. Requesting keys.");
3866 /* Request the keys held by the agent. */
3867 PUT_32BIT(request, 1);
3868 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3869 agent_query(request, 5, &r, &responselen);
3870 response = (unsigned char *) r;
3871 if (response && responselen >= 5 &&
3872 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3874 nkeys = GET_32BIT(p);
3878 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3881 for (i = 0; i < nkeys; i++) {
3882 static char *pkblob, *alg, *commentp;
3883 static int pklen, alglen, commentlen;
3884 static int siglen, retlen, len;
3885 static char *q, *agentreq, *ret;
3890 sprintf(buf, "Trying Pageant key #%d", i);
3893 pklen = GET_32BIT(p);
3897 alglen = GET_32BIT(pkblob);
3899 commentlen = GET_32BIT(p);
3903 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3904 ssh2_pkt_addstring(username);
3905 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3906 ssh2_pkt_addstring("publickey"); /* method */
3907 ssh2_pkt_addbool(FALSE); /* no signature included */
3908 ssh2_pkt_addstring_start();
3909 ssh2_pkt_addstring_data(alg, alglen);
3910 ssh2_pkt_addstring_start();
3911 ssh2_pkt_addstring_data(pkblob, pklen);
3914 crWaitUntilV(ispkt);
3915 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3916 logevent("Key refused");
3920 if (flags & FLAG_VERBOSE) {
3922 ("Authenticating with public key \"");
3923 c_write(commentp, commentlen);
3924 c_write_str("\" from agent\r\n");
3928 * Server is willing to accept the key.
3929 * Construct a SIGN_REQUEST.
3931 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3932 ssh2_pkt_addstring(username);
3933 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3934 ssh2_pkt_addstring("publickey"); /* method */
3935 ssh2_pkt_addbool(TRUE);
3936 ssh2_pkt_addstring_start();
3937 ssh2_pkt_addstring_data(alg, alglen);
3938 ssh2_pkt_addstring_start();
3939 ssh2_pkt_addstring_data(pkblob, pklen);
3941 siglen = pktout.length - 5 + 4 + 20;
3942 len = 1; /* message type */
3943 len += 4 + pklen; /* key blob */
3944 len += 4 + siglen; /* data to sign */
3945 len += 4; /* flags */
3946 agentreq = smalloc(4 + len);
3947 PUT_32BIT(agentreq, len);
3949 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3950 PUT_32BIT(q, pklen);
3952 memcpy(q, pkblob, pklen);
3954 PUT_32BIT(q, siglen);
3956 /* Now the data to be signed... */
3959 memcpy(q, ssh2_session_id, 20);
3961 memcpy(q, pktout.data + 5, pktout.length - 5);
3962 q += pktout.length - 5;
3963 /* And finally the (zero) flags word. */
3965 agent_query(agentreq, len + 4, &vret, &retlen);
3969 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3970 logevent("Sending Pageant's response");
3971 ssh2_pkt_addstring_start();
3972 ssh2_pkt_addstring_data(ret + 9,
3980 ("Pageant failed to answer challenge");
3990 if (!method && can_pubkey && *cfg.keyfile
3991 && !tried_pubkey_config) {
3992 unsigned char *pub_blob;
3993 char *algorithm, *comment;
3996 tried_pubkey_config = TRUE;
3999 * Try the public key supplied in the configuration.
4001 * First, offer the public blob to see if the server is
4002 * willing to accept it.
4004 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4007 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4008 ssh2_pkt_addstring(username);
4009 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4010 ssh2_pkt_addstring("publickey"); /* method */
4011 ssh2_pkt_addbool(FALSE); /* no signature included */
4012 ssh2_pkt_addstring(algorithm);
4013 ssh2_pkt_addstring_start();
4014 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4016 logevent("Offered public key"); /* FIXME */
4018 crWaitUntilV(ispkt);
4019 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4021 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4022 continue; /* key refused; give up on it */
4025 logevent("Offer of public key accepted");
4027 * Actually attempt a serious authentication using
4030 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4032 "Passphrase for key \"%.100s\": ",
4038 c_write_str("Authenticating with public key \"");
4039 c_write_str(comment);
4040 c_write_str("\"\r\n");
4041 method = AUTH_PUBLICKEY_FILE;
4045 if (!method && can_keyb_inter && !tried_keyb_inter) {
4046 method = AUTH_KEYBOARD_INTERACTIVE;
4047 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4048 tried_keyb_inter = TRUE;
4050 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4051 ssh2_pkt_addstring(username);
4052 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4053 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4054 ssh2_pkt_addstring(""); /* lang */
4055 ssh2_pkt_addstring("");
4058 crWaitUntilV(ispkt);
4059 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4060 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4062 logevent("Keyboard-interactive authentication refused");
4063 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4067 kbd_inter_running = TRUE;
4070 if (kbd_inter_running) {
4071 method = AUTH_KEYBOARD_INTERACTIVE;
4072 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4073 tried_keyb_inter = TRUE;
4075 /* We've got packet with that "interactive" info
4076 dump banners, and set its prompt as ours */
4078 char *name, *inst, *lang, *prompt;
4079 int name_len, inst_len, lang_len, prompt_len;
4080 ssh2_pkt_getstring(&name, &name_len);
4081 ssh2_pkt_getstring(&inst, &inst_len);
4082 ssh2_pkt_getstring(&lang, &lang_len);
4084 c_write_untrusted(name, name_len);
4086 c_write_untrusted(inst, inst_len);
4087 num_prompts = ssh2_pkt_getuint32();
4089 ssh2_pkt_getstring(&prompt, &prompt_len);
4090 strncpy(pwprompt, prompt, sizeof(pwprompt));
4093 echo = ssh2_pkt_getbool();
4097 if (!method && can_passwd) {
4098 method = AUTH_PASSWORD;
4099 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4106 if (!ssh_get_line(pwprompt, password,
4107 sizeof(password), TRUE)) {
4109 * get_line failed to get a password (for
4110 * example because one was supplied on the
4111 * command line which has already failed to
4114 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4115 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4117 ("No more passwords available to try");
4118 ssh2_pkt_addstring("en"); /* language tag */
4120 connection_fatal("Unable to authenticate");
4121 ssh_state = SSH_STATE_CLOSED;
4128 c_write_untrusted(pwprompt, strlen(pwprompt));
4133 crWaitUntilV(!ispkt);
4135 switch (c = *in++) {
4156 if (pos < sizeof(password)-1)
4157 password[pos++] = c;
4161 c_write_str("\r\n");
4165 if (method == AUTH_PUBLICKEY_FILE) {
4167 * We have our passphrase. Now try the actual authentication.
4169 struct ssh2_userkey *key;
4171 key = ssh2_load_userkey(cfg.keyfile, password);
4172 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4173 if (key == SSH2_WRONG_PASSPHRASE) {
4174 c_write_str("Wrong passphrase\r\n");
4175 tried_pubkey_config = FALSE;
4177 c_write_str("Unable to load private key\r\n");
4178 tried_pubkey_config = TRUE;
4180 /* Send a spurious AUTH_NONE to return to the top. */
4181 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4182 ssh2_pkt_addstring(username);
4183 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4184 ssh2_pkt_addstring("none"); /* method */
4186 type = AUTH_TYPE_NONE;
4188 unsigned char *blob, *sigdata;
4189 int blob_len, sigdata_len;
4192 * We have loaded the private key and the server
4193 * has announced that it's willing to accept it.
4194 * Hallelujah. Generate a signature and send it.
4196 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4197 ssh2_pkt_addstring(username);
4198 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4199 ssh2_pkt_addstring("publickey"); /* method */
4200 ssh2_pkt_addbool(TRUE);
4201 ssh2_pkt_addstring(key->alg->name);
4202 blob = key->alg->public_blob(key->data, &blob_len);
4203 ssh2_pkt_addstring_start();
4204 ssh2_pkt_addstring_data(blob, blob_len);
4208 * The data to be signed is:
4212 * followed by everything so far placed in the
4215 sigdata_len = pktout.length - 5 + 4 + 20;
4216 sigdata = smalloc(sigdata_len);
4217 PUT_32BIT(sigdata, 20);
4218 memcpy(sigdata + 4, ssh2_session_id, 20);
4219 memcpy(sigdata + 24, pktout.data + 5,
4222 key->alg->sign(key->data, sigdata, sigdata_len,
4224 ssh2_pkt_addstring_start();
4225 ssh2_pkt_addstring_data(blob, blob_len);
4230 type = AUTH_TYPE_PUBLICKEY;
4232 } else if (method == AUTH_PASSWORD) {
4234 * We send the password packet lumped tightly together with
4235 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4236 * string long enough to make the total length of the two
4237 * packets constant. This should ensure that a passive
4238 * listener doing traffic analyis can't work out the length
4241 * For this to work, we need an assumption about the
4242 * maximum length of the password packet. I think 256 is
4243 * pretty conservative. Anyone using a password longer than
4244 * that probably doesn't have much to worry about from
4245 * people who find out how long their password is!
4247 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4248 ssh2_pkt_addstring(username);
4249 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4250 ssh2_pkt_addstring("password");
4251 ssh2_pkt_addbool(FALSE);
4252 ssh2_pkt_addstring(password);
4255 * We'll include a string that's an exact multiple of the
4256 * cipher block size. If the cipher is NULL for some
4257 * reason, we don't do this trick at all because we gain
4263 stringlen = (256 - deferred_len);
4264 stringlen += cscipher->blksize - 1;
4265 stringlen -= (stringlen % cscipher->blksize);
4268 * Temporarily disable actual compression,
4269 * so we can guarantee to get this string
4270 * exactly the length we want it. The
4271 * compression-disabling routine should
4272 * return an integer indicating how many
4273 * bytes we should adjust our string length
4276 stringlen -= cscomp->disable_compression();
4278 ssh2_pkt_init(SSH2_MSG_IGNORE);
4279 ssh2_pkt_addstring_start();
4280 for (i = 0; i < stringlen; i++) {
4281 char c = (char) random_byte();
4282 ssh2_pkt_addstring_data(&c, 1);
4286 ssh_pkt_defersend();
4287 logevent("Sent password");
4288 type = AUTH_TYPE_PASSWORD;
4289 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4290 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4291 ssh2_pkt_adduint32(num_prompts);
4292 ssh2_pkt_addstring(password);
4293 memset(password, 0, sizeof(password));
4295 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4298 ("No supported authentication methods left to try!\r\n");
4300 ("No supported authentications offered. Disconnecting");
4301 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4302 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4304 ("No supported authentication methods available");
4305 ssh2_pkt_addstring("en"); /* language tag */
4307 ssh_state = SSH_STATE_CLOSED;
4311 } while (!we_are_in);
4314 * Now we're authenticated for the connection protocol. The
4315 * connection protocol will automatically have started at this
4316 * point; there's no need to send SERVICE_REQUEST.
4320 * So now create a channel with a session in it.
4322 ssh_channels = newtree234(ssh_channelcmp);
4323 mainchan = smalloc(sizeof(struct ssh_channel));
4324 mainchan->localid = alloc_channel_id();
4325 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4326 ssh2_pkt_addstring("session");
4327 ssh2_pkt_adduint32(mainchan->localid);
4328 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4329 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4330 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4332 crWaitUntilV(ispkt);
4333 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4334 bombout(("Server refused to open a session"));
4336 /* FIXME: error data comes back in FAILURE packet */
4338 if (ssh2_pkt_getuint32() != mainchan->localid) {
4339 bombout(("Server's channel confirmation cited wrong channel"));
4342 mainchan->remoteid = ssh2_pkt_getuint32();
4343 mainchan->type = CHAN_MAINSESSION;
4344 mainchan->closes = 0;
4345 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4346 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4347 bufchain_init(&mainchan->v.v2.outbuffer);
4348 add234(ssh_channels, mainchan);
4349 logevent("Opened channel for session");
4352 * Potentially enable X11 forwarding.
4354 if (cfg.x11_forward) {
4355 char proto[20], data[64];
4356 logevent("Requesting X11 forwarding");
4357 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4358 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4359 ssh2_pkt_adduint32(mainchan->remoteid);
4360 ssh2_pkt_addstring("x11-req");
4361 ssh2_pkt_addbool(1); /* want reply */
4362 ssh2_pkt_addbool(0); /* many connections */
4363 ssh2_pkt_addstring(proto);
4364 ssh2_pkt_addstring(data);
4365 ssh2_pkt_adduint32(0); /* screen number */
4369 crWaitUntilV(ispkt);
4370 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4371 unsigned i = ssh2_pkt_getuint32();
4372 struct ssh_channel *c;
4373 c = find234(ssh_channels, &i, ssh_channelfind);
4375 continue; /* nonexistent channel */
4376 c->v.v2.remwindow += ssh2_pkt_getuint32();
4378 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4380 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4381 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4382 bombout(("Unexpected response to X11 forwarding request:"
4383 " packet type %d", pktin.type));
4386 logevent("X11 forwarding refused");
4388 logevent("X11 forwarding enabled");
4389 ssh_X11_fwd_enabled = TRUE;
4394 * Enable port forwardings.
4397 static char *e; /* preserve across crReturn */
4401 char sports[256], dports[256], host[256];
4404 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4405 /* Add port forwardings. */
4410 while (*e && *e != '\t')
4416 while (*e && *e != ':')
4426 dport = atoi(dports);
4427 sport = atoi(sports);
4428 if (sport && dport) {
4430 pfd_addforward(host, dport, sport);
4431 sprintf(buf, "Local port %d forwarding to %s:%d",
4432 sport, host, dport);
4435 struct ssh_rportfwd *pf;
4436 pf = smalloc(sizeof(*pf));
4437 strcpy(pf->dhost, host);
4440 if (add234(ssh_rportfwds, pf) != pf) {
4442 "Duplicate remote port forwarding to %s:%d",
4447 sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
4448 sport, host, dport);
4450 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4451 ssh2_pkt_addstring("tcpip-forward");
4452 ssh2_pkt_addbool(1);/* want reply */
4453 ssh2_pkt_addstring("127.0.0.1");
4454 ssh2_pkt_adduint32(sport);
4458 crWaitUntilV(ispkt);
4459 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4460 unsigned i = ssh2_pkt_getuint32();
4461 struct ssh_channel *c;
4462 c = find234(ssh_channels, &i, ssh_channelfind);
4464 continue;/* nonexistent channel */
4465 c->v.v2.remwindow += ssh2_pkt_getuint32();
4467 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4469 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4470 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
4471 bombout(("Unexpected response to port "
4472 "forwarding request: packet type %d",
4476 logevent("Server refused this port forwarding");
4478 logevent("Remote port forwarding enabled");
4487 * Potentially enable agent forwarding.
4489 if (cfg.agentfwd && agent_exists()) {
4490 logevent("Requesting OpenSSH-style agent forwarding");
4491 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4492 ssh2_pkt_adduint32(mainchan->remoteid);
4493 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4494 ssh2_pkt_addbool(1); /* want reply */
4498 crWaitUntilV(ispkt);
4499 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4500 unsigned i = ssh2_pkt_getuint32();
4501 struct ssh_channel *c;
4502 c = find234(ssh_channels, &i, ssh_channelfind);
4504 continue; /* nonexistent channel */
4505 c->v.v2.remwindow += ssh2_pkt_getuint32();
4507 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4509 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4510 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4511 bombout(("Unexpected response to agent forwarding request:"
4512 " packet type %d", pktin.type));
4515 logevent("Agent forwarding refused");
4517 logevent("Agent forwarding enabled");
4518 ssh_agentfwd_enabled = TRUE;
4523 * Now allocate a pty for the session.
4526 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4527 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4528 ssh2_pkt_addstring("pty-req");
4529 ssh2_pkt_addbool(1); /* want reply */
4530 ssh2_pkt_addstring(cfg.termtype);
4531 ssh2_pkt_adduint32(cols);
4532 ssh2_pkt_adduint32(rows);
4533 ssh2_pkt_adduint32(0); /* pixel width */
4534 ssh2_pkt_adduint32(0); /* pixel height */
4535 ssh2_pkt_addstring_start();
4536 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4538 ssh_state = SSH_STATE_INTERMED;
4541 crWaitUntilV(ispkt);
4542 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4543 unsigned i = ssh2_pkt_getuint32();
4544 struct ssh_channel *c;
4545 c = find234(ssh_channels, &i, ssh_channelfind);
4547 continue; /* nonexistent channel */
4548 c->v.v2.remwindow += ssh2_pkt_getuint32();
4550 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4552 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4553 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4554 bombout(("Unexpected response to pty request:"
4555 " packet type %d", pktin.type));
4558 c_write_str("Server refused to allocate pty\r\n");
4559 ssh_editing = ssh_echoing = 1;
4561 logevent("Allocated pty");
4564 ssh_editing = ssh_echoing = 1;
4568 * Start a shell or a remote command. We may have to attempt
4569 * this twice if the config data has provided a second choice
4576 if (ssh_fallback_cmd) {
4577 subsys = cfg.ssh_subsys2;
4578 cmd = cfg.remote_cmd_ptr2;
4580 subsys = cfg.ssh_subsys;
4581 cmd = cfg.remote_cmd_ptr;
4584 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4585 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4587 ssh2_pkt_addstring("subsystem");
4588 ssh2_pkt_addbool(1); /* want reply */
4589 ssh2_pkt_addstring(cmd);
4591 ssh2_pkt_addstring("exec");
4592 ssh2_pkt_addbool(1); /* want reply */
4593 ssh2_pkt_addstring(cmd);
4595 ssh2_pkt_addstring("shell");
4596 ssh2_pkt_addbool(1); /* want reply */
4600 crWaitUntilV(ispkt);
4601 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4602 unsigned i = ssh2_pkt_getuint32();
4603 struct ssh_channel *c;
4604 c = find234(ssh_channels, &i, ssh_channelfind);
4606 continue; /* nonexistent channel */
4607 c->v.v2.remwindow += ssh2_pkt_getuint32();
4609 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4610 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4611 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4612 bombout(("Unexpected response to shell/command request:"
4613 " packet type %d", pktin.type));
4617 * We failed to start the command. If this is the
4618 * fallback command, we really are finished; if it's
4619 * not, and if the fallback command exists, try falling
4620 * back to it before complaining.
4622 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
4623 logevent("Primary command failed; attempting fallback");
4624 ssh_fallback_cmd = TRUE;
4627 bombout(("Server refused to start a shell/command"));
4630 logevent("Started a shell/command");
4635 ssh_state = SSH_STATE_SESSION;
4639 ssh_special(TS_EOF);
4644 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
4647 static int try_send;
4651 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
4652 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4655 unsigned i = ssh2_pkt_getuint32();
4656 struct ssh_channel *c;
4657 c = find234(ssh_channels, &i, ssh_channelfind);
4659 continue; /* nonexistent channel */
4660 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4661 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4662 continue; /* extended but not stderr */
4663 ssh2_pkt_getstring(&data, &length);
4666 c->v.v2.locwindow -= length;
4668 case CHAN_MAINSESSION:
4670 from_backend(pktin.type ==
4671 SSH2_MSG_CHANNEL_EXTENDED_DATA,
4675 bufsize = x11_send(c->u.x11.s, data, length);
4678 bufsize = pfd_send(c->u.pfd.s, data, length);
4681 while (length > 0) {
4682 if (c->u.a.lensofar < 4) {
4683 int l = min(4 - c->u.a.lensofar, length);
4684 memcpy(c->u.a.msglen + c->u.a.lensofar,
4688 c->u.a.lensofar += l;
4690 if (c->u.a.lensofar == 4) {
4692 4 + GET_32BIT(c->u.a.msglen);
4693 c->u.a.message = smalloc(c->u.a.totallen);
4694 memcpy(c->u.a.message, c->u.a.msglen, 4);
4696 if (c->u.a.lensofar >= 4 && length > 0) {
4698 min(c->u.a.totallen - c->u.a.lensofar,
4700 memcpy(c->u.a.message + c->u.a.lensofar,
4704 c->u.a.lensofar += l;
4706 if (c->u.a.lensofar == c->u.a.totallen) {
4707 void *reply, *sentreply;
4709 agent_query(c->u.a.message,
4710 c->u.a.totallen, &reply,
4715 /* Fake SSH_AGENT_FAILURE. */
4716 sentreply = "\0\0\0\1\5";
4719 ssh2_add_channel_data(c, sentreply,
4724 sfree(c->u.a.message);
4725 c->u.a.lensofar = 0;
4732 * If we are not buffering too much data,
4733 * enlarge the window again at the remote side.
4735 if (bufsize < OUR_V2_WINSIZE)
4736 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
4738 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4739 ssh_state = SSH_STATE_CLOSED;
4740 logevent("Received disconnect message");
4742 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
4743 continue; /* exit status et al; ignore (FIXME?) */
4744 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4745 unsigned i = ssh2_pkt_getuint32();
4746 struct ssh_channel *c;
4748 c = find234(ssh_channels, &i, ssh_channelfind);
4750 continue; /* nonexistent channel */
4752 if (c->type == CHAN_X11) {
4754 * Remote EOF on an X11 channel means we should
4755 * wrap up and close the channel ourselves.
4757 x11_close(c->u.x11.s);
4759 } else if (c->type == CHAN_AGENT) {
4761 } else if (c->type == CHAN_SOCKDATA) {
4762 pfd_close(c->u.pfd.s);
4765 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4766 unsigned i = ssh2_pkt_getuint32();
4767 struct ssh_channel *c;
4769 c = find234(ssh_channels, &i, ssh_channelfind);
4771 continue; /* nonexistent channel */
4772 /* Do pre-close processing on the channel. */
4774 case CHAN_MAINSESSION:
4775 break; /* nothing to see here, move along */
4777 if (c->u.x11.s != NULL)
4778 x11_close(c->u.x11.s);
4785 if (c->u.pfd.s != NULL)
4786 pfd_close(c->u.pfd.s);
4790 if (c->closes == 0) {
4791 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4792 ssh2_pkt_adduint32(c->remoteid);
4795 del234(ssh_channels, c);
4796 bufchain_clear(&c->v.v2.outbuffer);
4800 * See if that was the last channel left open.
4802 if (count234(ssh_channels) == 0) {
4803 logevent("All channels closed. Disconnecting");
4804 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4805 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4806 ssh2_pkt_addstring("All open channels closed");
4807 ssh2_pkt_addstring("en"); /* language tag */
4809 ssh_state = SSH_STATE_CLOSED;
4812 continue; /* remote sends close; ignore (FIXME) */
4813 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4814 unsigned i = ssh2_pkt_getuint32();
4815 struct ssh_channel *c;
4816 c = find234(ssh_channels, &i, ssh_channelfind);
4818 continue; /* nonexistent channel */
4819 c->v.v2.remwindow += ssh2_pkt_getuint32();
4821 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4822 unsigned i = ssh2_pkt_getuint32();
4823 struct ssh_channel *c;
4824 c = find234(ssh_channels, &i, ssh_channelfind);
4826 continue; /* nonexistent channel */
4827 if (c->type != CHAN_SOCKDATA_DORMANT)
4828 continue; /* dunno why they're confirming this */
4829 c->remoteid = ssh2_pkt_getuint32();
4830 c->type = CHAN_SOCKDATA;
4832 c->v.v2.remwindow = ssh2_pkt_getuint32();
4833 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4834 bufchain_init(&c->v.v2.outbuffer);
4835 pfd_confirm(c->u.pfd.s);
4836 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
4837 unsigned i = ssh2_pkt_getuint32();
4838 struct ssh_channel *c;
4839 c = find234(ssh_channels, &i, ssh_channelfind);
4841 continue; /* nonexistent channel */
4842 if (c->type != CHAN_SOCKDATA_DORMANT)
4843 continue; /* dunno why they're failing this */
4845 logevent("Forwarded connection refused by server");
4847 pfd_close(c->u.pfd.s);
4849 del234(ssh_channels, c);
4851 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
4855 struct ssh_channel *c;
4856 unsigned remid, winsize, pktsize;
4857 ssh2_pkt_getstring(&type, &typelen);
4858 c = smalloc(sizeof(struct ssh_channel));
4860 remid = ssh2_pkt_getuint32();
4861 winsize = ssh2_pkt_getuint32();
4862 pktsize = ssh2_pkt_getuint32();
4864 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4865 if (!ssh_X11_fwd_enabled)
4866 error = "X11 forwarding is not enabled";
4867 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4869 error = "Unable to open an X11 connection";
4873 } else if (typelen == 15 &&
4874 !memcmp(type, "forwarded-tcpip", 15)) {
4875 struct ssh_rportfwd pf, *realpf;
4878 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
4879 pf.sport = ssh2_pkt_getuint32();
4880 realpf = find234(ssh_rportfwds, &pf, NULL);
4881 if (realpf == NULL) {
4882 error = "Remote port is not recognised";
4884 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
4887 sprintf(buf, "Received remote port open request for %s:%d",
4888 realpf->dhost, realpf->dport);
4891 sprintf(buf, "Port open failed: %s", e);
4893 error = "Port open failed";
4895 logevent("Forwarded port opened successfully");
4896 c->type = CHAN_SOCKDATA;
4899 } else if (typelen == 22 &&
4900 !memcmp(type, "auth-agent@openssh.com", 3)) {
4901 if (!ssh_agentfwd_enabled)
4902 error = "Agent forwarding is not enabled";
4904 c->type = CHAN_AGENT; /* identify channel type */
4905 c->u.a.lensofar = 0;
4908 error = "Unsupported channel type requested";
4911 c->remoteid = remid;
4913 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4914 ssh2_pkt_adduint32(c->remoteid);
4915 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4916 ssh2_pkt_addstring(error);
4917 ssh2_pkt_addstring("en"); /* language tag */
4921 c->localid = alloc_channel_id();
4923 c->v.v2.locwindow = OUR_V2_WINSIZE;
4924 c->v.v2.remwindow = winsize;
4925 c->v.v2.remmaxpkt = pktsize;
4926 bufchain_init(&c->v.v2.outbuffer);
4927 add234(ssh_channels, c);
4928 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4929 ssh2_pkt_adduint32(c->remoteid);
4930 ssh2_pkt_adduint32(c->localid);
4931 ssh2_pkt_adduint32(c->v.v2.locwindow);
4932 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4936 bombout(("Strange packet received: type %d", pktin.type));
4941 * We have spare data. Add it to the channel buffer.
4943 ssh2_add_channel_data(mainchan, in, inlen);
4948 struct ssh_channel *c;
4950 * Try to send data on all channels if we can.
4952 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
4953 int bufsize = ssh2_try_send(c);
4956 case CHAN_MAINSESSION:
4957 /* stdin need not receive an unthrottle
4958 * notification since it will be polled */
4961 x11_unthrottle(c->u.x11.s);
4964 /* agent sockets are request/response and need no
4965 * buffer management */
4968 pfd_unthrottle(c->u.pfd.s);
4980 * Handle the top-level SSH2 protocol.
4982 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4984 if (do_ssh2_transport(in, inlen, ispkt) == 0)
4986 do_ssh2_authconn(in, inlen, ispkt);
4990 * Called to set up the connection.
4992 * Returns an error message, or NULL on success.
4994 static char *ssh_init(char *host, int port, char **realhost)
4999 if (crypto_startup() == 0)
5000 return "Microsoft high encryption pack not installed!";
5006 ssh1_throttle_count = 0;
5007 ssh_overall_bufsize = 0;
5008 ssh_fallback_cmd = 0;
5010 p = connect_to_host(host, port, realhost);
5018 * Called to send data down the Telnet connection.
5020 static int ssh_send(char *buf, int len)
5022 if (s == NULL || ssh_protocol == NULL)
5025 ssh_protocol(buf, len, 0);
5027 return ssh_sendbuffer();
5031 * Called to query the current amount of buffered stdin data.
5033 static int ssh_sendbuffer(void)
5037 if (s == NULL || ssh_protocol == NULL)
5041 * If the SSH socket itself has backed up, add the total backup
5042 * size on that to any individual buffer on the stdin channel.
5045 if (ssh_throttled_all)
5046 override_value = ssh_overall_bufsize;
5048 if (ssh_version == 1) {
5049 return override_value;
5050 } else if (ssh_version == 2) {
5051 if (!mainchan || mainchan->closes > 0)
5052 return override_value;
5054 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5061 * Called to set the size of the window from SSH's POV.
5063 static void ssh_size(void)
5065 switch (ssh_state) {
5066 case SSH_STATE_BEFORE_SIZE:
5067 case SSH_STATE_PREPACKET:
5068 case SSH_STATE_CLOSED:
5069 break; /* do nothing */
5070 case SSH_STATE_INTERMED:
5071 size_needed = TRUE; /* buffer for later */
5073 case SSH_STATE_SESSION:
5075 if (ssh_version == 1) {
5076 send_packet(SSH1_CMSG_WINDOW_SIZE,
5077 PKT_INT, rows, PKT_INT, cols,
5078 PKT_INT, 0, PKT_INT, 0, PKT_END);
5080 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5081 ssh2_pkt_adduint32(mainchan->remoteid);
5082 ssh2_pkt_addstring("window-change");
5083 ssh2_pkt_addbool(0);
5084 ssh2_pkt_adduint32(cols);
5085 ssh2_pkt_adduint32(rows);
5086 ssh2_pkt_adduint32(0);
5087 ssh2_pkt_adduint32(0);
5096 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5097 * can send an EOF and collect resulting output (e.g. `plink
5100 static void ssh_special(Telnet_Special code)
5102 if (code == TS_EOF) {
5103 if (ssh_state != SSH_STATE_SESSION) {
5105 * Buffer the EOF in case we are pre-SESSION, so we can
5106 * send it as soon as we reach SESSION.
5112 if (ssh_version == 1) {
5113 send_packet(SSH1_CMSG_EOF, PKT_END);
5115 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5116 ssh2_pkt_adduint32(mainchan->remoteid);
5119 logevent("Sent EOF message");
5120 } else if (code == TS_PING) {
5121 if (ssh_state == SSH_STATE_CLOSED
5122 || ssh_state == SSH_STATE_PREPACKET) return;
5123 if (ssh_version == 1) {
5124 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5126 ssh2_pkt_init(SSH2_MSG_IGNORE);
5127 ssh2_pkt_addstring_start();
5135 void *new_sock_channel(Socket s)
5137 struct ssh_channel *c;
5138 c = smalloc(sizeof(struct ssh_channel));
5141 c->remoteid = -1; /* to be set when open confirmed */
5142 c->localid = alloc_channel_id();
5144 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5146 add234(ssh_channels, c);
5152 * This is called when stdout/stderr (the entity to which
5153 * from_backend sends data) manages to clear some backlog.
5155 void ssh_unthrottle(int bufsize)
5157 if (ssh_version == 1) {
5158 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5159 ssh1_stdout_throttling = 0;
5163 if (mainchan && mainchan->closes == 0)
5164 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5168 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5170 struct ssh_channel *c = (struct ssh_channel *)channel;
5173 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5176 if (ssh_version == 1) {
5177 send_packet(SSH1_MSG_PORT_OPEN,
5178 PKT_INT, c->localid,
5181 //PKT_STR, <org:orgport>,
5184 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5185 ssh2_pkt_addstring("direct-tcpip");
5186 ssh2_pkt_adduint32(c->localid);
5187 c->v.v2.locwindow = OUR_V2_WINSIZE;
5188 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5189 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5190 ssh2_pkt_addstring(hostname);
5191 ssh2_pkt_adduint32(port);
5193 * We make up values for the originator data; partly it's
5194 * too much hassle to keep track, and partly I'm not
5195 * convinced the server should be told details like that
5196 * about my local network configuration.
5198 ssh2_pkt_addstring("client-side-connection");
5199 ssh2_pkt_adduint32(0);
5205 static Socket ssh_socket(void)
5210 static int ssh_sendok(void)
5215 static int ssh_ldisc(int option)
5217 if (option == LD_ECHO)
5219 if (option == LD_EDIT)
5224 Backend ssh_backend = {