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)--;
611 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
612 st->len = 0x300; /* big enough to carry to end */
616 st->pad = 8 - (st->len % 8);
617 st->biglen = st->len + st->pad;
618 pktin.length = st->len - 5;
620 if (pktin.maxlen < st->biglen) {
621 pktin.maxlen = st->biglen;
622 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
623 srealloc(pktin.data, st->biglen + APIEXTRA));
625 fatalbox("Out of memory");
628 st->to_read = st->biglen;
630 while (st->to_read > 0) {
631 st->chunk = st->to_read;
632 while ((*datalen) == 0)
633 crReturn(st->to_read);
634 if (st->chunk > (*datalen))
635 st->chunk = (*datalen);
636 memcpy(st->p, *data, st->chunk);
638 *datalen -= st->chunk;
640 st->to_read -= st->chunk;
644 cipher->decrypt(pktin.data, st->biglen);
646 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
647 dmemdump(pktin.data, st->biglen);
650 st->realcrc = crc32(pktin.data, st->biglen - 4);
651 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
652 if (st->gotcrc != st->realcrc) {
653 bombout(("Incorrect CRC received on packet"));
657 pktin.body = pktin.data + st->pad + 1;
659 if (ssh1_compressing) {
660 unsigned char *decompblk;
663 debug(("Packet payload pre-decompression:\n"));
664 dmemdump(pktin.body - 1, pktin.length + 1);
666 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
667 &decompblk, &decomplen);
669 if (pktin.maxlen < st->pad + decomplen) {
670 pktin.maxlen = st->pad + decomplen;
671 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
672 pktin.body = pktin.data + st->pad + 1;
674 fatalbox("Out of memory");
677 memcpy(pktin.body - 1, decompblk, decomplen);
679 pktin.length = decomplen - 1;
681 debug(("Packet payload post-decompression:\n"));
682 dmemdump(pktin.body - 1, pktin.length + 1);
686 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
687 pktin.type == SSH1_SMSG_STDERR_DATA ||
688 pktin.type == SSH1_MSG_DEBUG ||
689 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
690 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
691 long strlen = GET_32BIT(pktin.body);
692 if (strlen + 4 != pktin.length) {
693 bombout(("Received data packet with bogus string length"));
698 pktin.type = pktin.body[-1];
700 if (pktin.type == SSH1_MSG_DEBUG) {
701 /* log debug message */
703 int strlen = GET_32BIT(pktin.body);
704 strcpy(buf, "Remote: ");
707 memcpy(buf + 8, pktin.body + 4, strlen);
708 buf[8 + strlen] = '\0';
711 } else if (pktin.type == SSH1_MSG_IGNORE) {
716 if (pktin.type == SSH1_MSG_DISCONNECT) {
717 /* log reason code in disconnect message */
719 unsigned msglen = GET_32BIT(pktin.body);
721 strcpy(buf, "Remote sent disconnect: ");
722 nowlen = strlen(buf);
723 if (msglen > sizeof(buf) - nowlen - 1)
724 msglen = sizeof(buf) - nowlen - 1;
725 memcpy(buf + nowlen, pktin.body + 4, msglen);
726 buf[nowlen + msglen] = '\0';
733 static int ssh2_rdpkt(unsigned char **data, int *datalen)
735 struct rdpkt2_state_tag *st = &rdpkt2_state;
743 st->cipherblk = sccipher->blksize;
746 if (st->cipherblk < 8)
749 if (pktin.maxlen < st->cipherblk) {
750 pktin.maxlen = st->cipherblk;
753 NULL ? smalloc(st->cipherblk +
754 APIEXTRA) : srealloc(pktin.data,
758 fatalbox("Out of memory");
762 * Acquire and decrypt the first block of the packet. This will
763 * contain the length and padding details.
765 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
766 while ((*datalen) == 0)
767 crReturn(st->cipherblk - st->i);
768 pktin.data[st->i] = *(*data)++;
772 if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */
777 sccipher->decrypt(pktin.data, st->cipherblk);
780 * Now get the length and padding figures.
782 st->len = GET_32BIT(pktin.data);
783 st->pad = pktin.data[4];
786 * This enables us to deduce the payload length.
788 st->payload = st->len - st->pad - 1;
790 pktin.length = st->payload + 5;
793 * So now we can work out the total packet length.
795 st->packetlen = st->len + 4;
796 st->maclen = scmac ? scmac->len : 0;
799 * Adjust memory allocation if packet is too big.
801 if (pktin.maxlen < st->packetlen + st->maclen) {
802 pktin.maxlen = st->packetlen + st->maclen;
805 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
810 fatalbox("Out of memory");
814 * Read and decrypt the remainder of the packet.
816 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
818 while ((*datalen) == 0)
819 crReturn(st->packetlen + st->maclen - st->i);
820 pktin.data[st->i] = *(*data)++;
823 /* Decrypt everything _except_ the MAC. */
825 sccipher->decrypt(pktin.data + st->cipherblk,
826 st->packetlen - st->cipherblk);
829 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
830 dmemdump(pktin.data, st->packetlen);
837 && !scmac->verify(pktin.data, st->len + 4,
838 st->incoming_sequence)) {
839 bombout(("Incorrect MAC received on packet"));
842 st->incoming_sequence++; /* whether or not we MACed */
845 * Decompress packet payload.
848 unsigned char *newpayload;
850 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
851 &newpayload, &newlen)) {
852 if (pktin.maxlen < newlen + 5) {
853 pktin.maxlen = newlen + 5;
856 NULL ? smalloc(pktin.maxlen +
857 APIEXTRA) : srealloc(pktin.data,
861 fatalbox("Out of memory");
863 pktin.length = 5 + newlen;
864 memcpy(pktin.data + 5, newpayload, newlen);
866 debug(("Post-decompression payload:\n"));
867 dmemdump(pktin.data + 5, newlen);
875 pktin.type = pktin.data[5];
877 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
878 goto next_packet; /* FIXME: print DEBUG message */
880 if (pktin.type == SSH2_MSG_DISCONNECT) {
881 /* log reason code in disconnect message */
883 int reason = GET_32BIT(pktin.data + 6);
884 unsigned msglen = GET_32BIT(pktin.data + 10);
886 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
887 sprintf(buf, "Received disconnect message (%s)",
888 ssh2_disconnect_reasons[reason]);
890 sprintf(buf, "Received disconnect message (unknown type %d)",
894 strcpy(buf, "Disconnection message text: ");
895 nowlen = strlen(buf);
896 if (msglen > sizeof(buf) - nowlen - 1)
897 msglen = sizeof(buf) - nowlen - 1;
898 memcpy(buf + nowlen, pktin.data + 14, msglen);
899 buf[nowlen + msglen] = '\0';
906 static void ssh1_pktout_size(int len)
910 len += 5; /* type and CRC */
914 pktout.length = len - 5;
915 if (pktout.maxlen < biglen) {
916 pktout.maxlen = biglen;
918 /* Allocate enough buffer space for extra block
919 * for MS CryptEncrypt() */
920 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
921 srealloc(pktout.data, biglen + 12));
923 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
924 srealloc(pktout.data, biglen + 4));
927 fatalbox("Out of memory");
929 pktout.body = pktout.data + 4 + pad + 1;
932 static void s_wrpkt_start(int type, int len)
934 ssh1_pktout_size(len);
938 static int s_wrpkt_prepare(void)
940 int pad, len, biglen, i;
943 pktout.body[-1] = pktout.type;
946 debug(("Packet payload pre-compression:\n"));
947 dmemdump(pktout.body - 1, pktout.length + 1);
950 if (ssh1_compressing) {
951 unsigned char *compblk;
953 zlib_compress_block(pktout.body - 1, pktout.length + 1,
955 ssh1_pktout_size(complen - 1);
956 memcpy(pktout.body - 1, compblk, complen);
959 debug(("Packet payload post-compression:\n"));
960 dmemdump(pktout.body - 1, pktout.length + 1);
964 len = pktout.length + 5; /* type and CRC */
968 for (i = 0; i < pad; i++)
969 pktout.data[i + 4] = random_byte();
970 crc = crc32(pktout.data + 4, biglen - 4);
971 PUT_32BIT(pktout.data + biglen, crc);
972 PUT_32BIT(pktout.data, len);
975 debug(("Sending packet len=%d\n", biglen + 4));
976 dmemdump(pktout.data, biglen + 4);
979 cipher->encrypt(pktout.data + 4, biglen);
984 static void s_wrpkt(void)
987 len = s_wrpkt_prepare();
988 backlog = sk_write(s, pktout.data, len);
989 if (backlog > SSH_MAX_BACKLOG)
990 ssh_throttle_all(1, backlog);
993 static void s_wrpkt_defer(void)
996 len = s_wrpkt_prepare();
997 if (deferred_len + len > deferred_size) {
998 deferred_size = deferred_len + len + 128;
999 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1001 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1002 deferred_len += len;
1006 * Construct a packet with the specified contents.
1008 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
1010 unsigned char *p, *argp, argchar;
1011 unsigned long argint;
1012 int pktlen, argtype, arglen;
1016 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1019 (void) va_arg(ap1, int);
1023 (void) va_arg(ap1, char);
1027 (void) va_arg(ap1, unsigned char *);
1028 arglen = va_arg(ap1, int);
1032 argp = va_arg(ap1, unsigned char *);
1033 arglen = strlen(argp);
1034 pktlen += 4 + arglen;
1037 bn = va_arg(ap1, Bignum);
1038 pktlen += ssh1_bignum_length(bn);
1045 s_wrpkt_start(pkttype, pktlen);
1048 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1051 argint = va_arg(ap2, int);
1052 PUT_32BIT(p, argint);
1056 argchar = va_arg(ap2, unsigned char);
1061 argp = va_arg(ap2, unsigned char *);
1062 arglen = va_arg(ap2, int);
1063 memcpy(p, argp, arglen);
1067 argp = va_arg(ap2, unsigned char *);
1068 arglen = strlen(argp);
1069 PUT_32BIT(p, arglen);
1070 memcpy(p + 4, argp, arglen);
1074 bn = va_arg(ap2, Bignum);
1075 p += ssh1_write_bignum(p, bn);
1081 static void send_packet(int pkttype, ...)
1084 va_start(ap1, pkttype);
1085 va_start(ap2, pkttype);
1086 construct_packet(pkttype, ap1, ap2);
1090 static void defer_packet(int pkttype, ...)
1093 va_start(ap1, pkttype);
1094 va_start(ap2, pkttype);
1095 construct_packet(pkttype, ap1, ap2);
1099 static int ssh_versioncmp(char *a, char *b)
1102 unsigned long av, bv;
1104 av = strtoul(a, &ae, 10);
1105 bv = strtoul(b, &be, 10);
1107 return (av < bv ? -1 : +1);
1112 av = strtoul(ae, &ae, 10);
1113 bv = strtoul(be, &be, 10);
1115 return (av < bv ? -1 : +1);
1121 * Utility routines for putting an SSH-protocol `string' and
1122 * `uint32' into a SHA state.
1125 static void sha_string(SHA_State * s, void *str, int len)
1127 unsigned char lenblk[4];
1128 PUT_32BIT(lenblk, len);
1129 SHA_Bytes(s, lenblk, 4);
1130 SHA_Bytes(s, str, len);
1133 static void sha_uint32(SHA_State * s, unsigned i)
1135 unsigned char intblk[4];
1136 PUT_32BIT(intblk, i);
1137 SHA_Bytes(s, intblk, 4);
1141 * SSH2 packet construction functions.
1143 static void ssh2_pkt_ensure(int length)
1145 if (pktout.maxlen < length) {
1146 pktout.maxlen = length + 256;
1149 NULL ? smalloc(pktout.maxlen +
1150 APIEXTRA) : srealloc(pktout.data,
1154 fatalbox("Out of memory");
1157 static void ssh2_pkt_adddata(void *data, int len)
1159 pktout.length += len;
1160 ssh2_pkt_ensure(pktout.length);
1161 memcpy(pktout.data + pktout.length - len, data, len);
1163 static void ssh2_pkt_addbyte(unsigned char byte)
1165 ssh2_pkt_adddata(&byte, 1);
1167 static void ssh2_pkt_init(int pkt_type)
1170 ssh2_pkt_addbyte((unsigned char) pkt_type);
1172 static void ssh2_pkt_addbool(unsigned char value)
1174 ssh2_pkt_adddata(&value, 1);
1176 static void ssh2_pkt_adduint32(unsigned long value)
1179 PUT_32BIT(x, value);
1180 ssh2_pkt_adddata(x, 4);
1182 static void ssh2_pkt_addstring_start(void)
1184 ssh2_pkt_adduint32(0);
1185 pktout.savedpos = pktout.length;
1187 static void ssh2_pkt_addstring_str(char *data)
1189 ssh2_pkt_adddata(data, strlen(data));
1190 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1191 pktout.length - pktout.savedpos);
1193 static void ssh2_pkt_addstring_data(char *data, int len)
1195 ssh2_pkt_adddata(data, len);
1196 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1197 pktout.length - pktout.savedpos);
1199 static void ssh2_pkt_addstring(char *data)
1201 ssh2_pkt_addstring_start();
1202 ssh2_pkt_addstring_str(data);
1204 static char *ssh2_mpint_fmt(Bignum b, int *len)
1207 int i, n = (bignum_bitcount(b) + 7) / 8;
1210 fatalbox("out of memory");
1212 for (i = 1; i <= n; i++)
1213 p[i] = bignum_byte(b, n - i);
1215 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1217 memmove(p, p + i, n + 1 - i);
1221 static void ssh2_pkt_addmp(Bignum b)
1225 p = ssh2_mpint_fmt(b, &len);
1226 ssh2_pkt_addstring_start();
1227 ssh2_pkt_addstring_data(p, len);
1232 * Construct an SSH2 final-form packet: compress it, encrypt it,
1233 * put the MAC on it. Final packet, ready to be sent, is stored in
1234 * pktout.data. Total length is returned.
1236 static int ssh2_pkt_construct(void)
1238 int cipherblk, maclen, padding, i;
1239 static unsigned long outgoing_sequence = 0;
1242 * Compress packet payload.
1245 debug(("Pre-compression payload:\n"));
1246 dmemdump(pktout.data + 5, pktout.length - 5);
1249 unsigned char *newpayload;
1251 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1252 &newpayload, &newlen)) {
1254 ssh2_pkt_adddata(newpayload, newlen);
1260 * Add padding. At least four bytes, and must also bring total
1261 * length (minus MAC) up to a multiple of the block size.
1263 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1264 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1267 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1268 maclen = csmac ? csmac->len : 0;
1269 ssh2_pkt_ensure(pktout.length + padding + maclen);
1270 pktout.data[4] = padding;
1271 for (i = 0; i < padding; i++)
1272 pktout.data[pktout.length + i] = random_byte();
1273 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1275 csmac->generate(pktout.data, pktout.length + padding,
1277 outgoing_sequence++; /* whether or not we MACed */
1280 debug(("Sending packet len=%d\n", pktout.length + padding));
1281 dmemdump(pktout.data, pktout.length + padding);
1285 cscipher->encrypt(pktout.data, pktout.length + padding);
1287 /* Ready-to-send packet starts at pktout.data. We return length. */
1288 return pktout.length + padding + maclen;
1292 * Construct and send an SSH2 packet immediately.
1294 static void ssh2_pkt_send(void)
1298 len = ssh2_pkt_construct();
1299 backlog = sk_write(s, pktout.data, len);
1300 if (backlog > SSH_MAX_BACKLOG)
1301 ssh_throttle_all(1, backlog);
1305 * Construct an SSH2 packet and add it to a deferred data block.
1306 * Useful for sending multiple packets in a single sk_write() call,
1307 * to prevent a traffic-analysing listener from being able to work
1308 * out the length of any particular packet (such as the password
1311 * Note that because SSH2 sequence-numbers its packets, this can
1312 * NOT be used as an m4-style `defer' allowing packets to be
1313 * constructed in one order and sent in another.
1315 static void ssh2_pkt_defer(void)
1317 int len = ssh2_pkt_construct();
1318 if (deferred_len + len > deferred_size) {
1319 deferred_size = deferred_len + len + 128;
1320 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1322 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1323 deferred_len += len;
1327 * Send the whole deferred data block constructed by
1328 * ssh2_pkt_defer() or SSH1's defer_packet().
1330 static void ssh_pkt_defersend(void)
1333 backlog = sk_write(s, deferred_send_data, deferred_len);
1334 deferred_len = deferred_size = 0;
1335 sfree(deferred_send_data);
1336 deferred_send_data = NULL;
1337 if (backlog > SSH_MAX_BACKLOG)
1338 ssh_throttle_all(1, backlog);
1342 void bndebug(char *string, Bignum b)
1346 p = ssh2_mpint_fmt(b, &len);
1347 debug(("%s", string));
1348 for (i = 0; i < len; i++)
1349 debug((" %02x", p[i]));
1355 static void sha_mpint(SHA_State * s, Bignum b)
1359 p = ssh2_mpint_fmt(b, &len);
1360 sha_string(s, p, len);
1365 * SSH2 packet decode functions.
1367 static unsigned long ssh2_pkt_getuint32(void)
1369 unsigned long value;
1370 if (pktin.length - pktin.savedpos < 4)
1371 return 0; /* arrgh, no way to decline (FIXME?) */
1372 value = GET_32BIT(pktin.data + pktin.savedpos);
1373 pktin.savedpos += 4;
1376 static int ssh2_pkt_getbool(void)
1378 unsigned long value;
1379 if (pktin.length - pktin.savedpos < 1)
1380 return 0; /* arrgh, no way to decline (FIXME?) */
1381 value = pktin.data[pktin.savedpos] != 0;
1385 static void ssh2_pkt_getstring(char **p, int *length)
1388 if (pktin.length - pktin.savedpos < 4)
1390 *length = GET_32BIT(pktin.data + pktin.savedpos);
1391 pktin.savedpos += 4;
1392 if (pktin.length - pktin.savedpos < *length)
1394 *p = pktin.data + pktin.savedpos;
1395 pktin.savedpos += *length;
1397 static Bignum ssh2_pkt_getmp(void)
1403 ssh2_pkt_getstring(&p, &length);
1407 bombout(("internal error: Can't handle negative mpints"));
1410 b = bignum_from_bytes(p, length);
1415 * Examine the remote side's version string and compare it against
1416 * a list of known buggy implementations.
1418 static void ssh_detect_bugs(char *vstring)
1420 char *imp; /* pointer to implementation part */
1422 imp += strcspn(imp, "-");
1425 imp += strcspn(imp, "-");
1429 ssh_remote_bugs = 0;
1431 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1432 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1433 !strcmp(imp, "1.2.22")) {
1435 * These versions don't support SSH1_MSG_IGNORE, so we have
1436 * to use a different defence against password length
1439 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1440 logevent("We believe remote version has SSH1 ignore bug");
1443 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1444 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1445 !strncmp(imp, "2.1 ", 4)) {
1447 * These versions have the HMAC bug.
1449 ssh_remote_bugs |= BUG_SSH2_HMAC;
1450 logevent("We believe remote version has SSH2 HMAC bug");
1454 static int do_ssh_init(unsigned char c)
1457 static char version[10];
1458 static char *vstring;
1459 static int vstrsize;
1465 /* Search for the string "SSH-" in the input. */
1468 static const int transS[] = { 1, 2, 2, 1 };
1469 static const int transH[] = { 0, 0, 3, 0 };
1470 static const int transminus[] = { 0, 0, 0, -1 };
1481 crReturn(1); /* get another character */
1484 vstring = smalloc(16);
1486 strcpy(vstring, "SSH-");
1490 crReturn(1); /* get another char */
1491 if (vslen >= vstrsize - 1) {
1493 vstring = srealloc(vstring, vstrsize);
1495 vstring[vslen++] = c;
1500 } else if (i < sizeof(version) - 1)
1502 } else if (c == '\n')
1506 ssh_agentfwd_enabled = FALSE;
1507 rdpkt2_state.incoming_sequence = 0;
1510 vlog = smalloc(20 + vslen);
1511 sprintf(vlog, "Server version: %s", vstring);
1512 ssh_detect_bugs(vstring);
1513 vlog[strcspn(vlog, "\r\n")] = '\0';
1518 * Server version "1.99" means we can choose whether we use v1
1519 * or v2 protocol. Choice is based on cfg.sshprot.
1521 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1523 * This is a v2 server. Begin v2 protocol.
1525 char verstring[80], vlog[100];
1526 sprintf(verstring, "SSH-2.0-%s", sshver);
1527 SHA_Init(&exhashbase);
1529 * Hash our version string and their version string.
1531 sha_string(&exhashbase, verstring, strlen(verstring));
1532 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1533 sprintf(vlog, "We claim version: %s", verstring);
1535 strcat(verstring, "\n");
1536 logevent("Using SSH protocol version 2");
1537 sk_write(s, verstring, strlen(verstring));
1538 ssh_protocol = ssh2_protocol;
1540 s_rdpkt = ssh2_rdpkt;
1543 * This is a v1 server. Begin v1 protocol.
1545 char verstring[80], vlog[100];
1546 sprintf(verstring, "SSH-%s-%s",
1547 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1549 sprintf(vlog, "We claim version: %s", verstring);
1551 strcat(verstring, "\n");
1552 logevent("Using SSH protocol version 1");
1553 sk_write(s, verstring, strlen(verstring));
1554 ssh_protocol = ssh1_protocol;
1556 s_rdpkt = ssh1_rdpkt;
1558 ssh_state = SSH_STATE_BEFORE_SIZE;
1565 static void ssh_gotdata(unsigned char *data, int datalen)
1570 * To begin with, feed the characters one by one to the
1571 * protocol initialisation / selection function do_ssh_init().
1572 * When that returns 0, we're done with the initial greeting
1573 * exchange and can move on to packet discipline.
1578 crReturnV; /* more data please */
1579 ret = do_ssh_init(*data);
1587 * We emerge from that loop when the initial negotiation is
1588 * over and we have selected an s_rdpkt function. Now pass
1589 * everything to s_rdpkt, and then pass the resulting packets
1590 * to the proper protocol handler.
1595 while (datalen > 0) {
1596 if (s_rdpkt(&data, &datalen) == 0) {
1597 ssh_protocol(NULL, 0, 1);
1598 if (ssh_state == SSH_STATE_CLOSED) {
1608 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1611 ssh_state = SSH_STATE_CLOSED;
1617 /* A socket error has occurred. */
1618 connection_fatal(error_msg);
1620 /* Otherwise, the remote side closed the connection normally. */
1625 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1627 ssh_gotdata(data, len);
1628 if (ssh_state == SSH_STATE_CLOSED) {
1638 static void ssh_sent(Plug plug, int bufsize)
1641 * If the send backlog on the SSH socket itself clears, we
1642 * should unthrottle the whole world if it was throttled.
1644 if (bufsize < SSH_MAX_BACKLOG)
1645 ssh_throttle_all(0, bufsize);
1649 * Connect to specified host and port.
1650 * Returns an error message, or NULL on success.
1651 * Also places the canonical host name into `realhost'. It must be
1652 * freed by the caller.
1654 static char *connect_to_host(char *host, int port, char **realhost)
1656 static struct plug_function_table fn_table = {
1661 }, *fn_table_ptr = &fn_table;
1670 savedhost = smalloc(1 + strlen(host));
1672 fatalbox("Out of memory");
1673 strcpy(savedhost, host);
1676 port = 22; /* default ssh port */
1689 addr = sk_namelookup(host, realhost);
1690 if ((err = sk_addr_error(addr)))
1694 *realhost = strdup(FWhost);
1700 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1701 if ((err = sk_socket_error(s)))
1705 sk_write(s, "connect ", 8);
1706 sk_write(s, FWhost, strlen(FWhost));
1709 sprintf(buf, " %d\n", FWport);
1710 sk_write(s, buf, strlen(buf));
1718 * Throttle or unthrottle the SSH connection.
1720 static void ssh1_throttle(int adjust)
1722 int old_count = ssh1_throttle_count;
1723 ssh1_throttle_count += adjust;
1724 assert(ssh1_throttle_count >= 0);
1725 if (ssh1_throttle_count && !old_count) {
1726 sk_set_frozen(s, 1);
1727 } else if (!ssh1_throttle_count && old_count) {
1728 sk_set_frozen(s, 0);
1733 * Throttle or unthrottle _all_ local data streams (for when sends
1734 * on the SSH connection itself back up).
1736 static void ssh_throttle_all(int enable, int bufsize)
1739 struct ssh_channel *c;
1741 if (enable == ssh_throttled_all)
1743 ssh_throttled_all = enable;
1744 ssh_overall_bufsize = bufsize;
1747 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
1749 case CHAN_MAINSESSION:
1751 * This is treated separately, outside the switch.
1755 x11_override_throttle(c->u.x11.s, enable);
1758 /* Agent channels require no buffer management. */
1761 pfd_override_throttle(c->u.x11.s, enable);
1768 * Handle the key exchange and user authentication phases.
1770 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1774 static unsigned char *rsabuf, *keystr1, *keystr2;
1775 unsigned char cookie[8];
1776 struct RSAKey servkey, hostkey;
1777 struct MD5Context md5c;
1778 static unsigned long supported_ciphers_mask, supported_auths_mask;
1779 static int tried_publickey;
1780 static unsigned char session_id[16];
1781 static int cipher_type;
1782 static char username[100];
1789 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1790 bombout(("Public key packet not received"));
1794 logevent("Received public keys");
1796 memcpy(cookie, pktin.body, 8);
1798 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1799 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1802 * Log the host key fingerprint.
1806 logevent("Host key fingerprint is:");
1807 strcpy(logmsg, " ");
1808 hostkey.comment = NULL;
1809 rsa_fingerprint(logmsg + strlen(logmsg),
1810 sizeof(logmsg) - strlen(logmsg), &hostkey);
1814 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1815 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1816 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1818 ssh1_local_protoflags =
1819 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1820 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1823 MD5Update(&md5c, keystr2, hostkey.bytes);
1824 MD5Update(&md5c, keystr1, servkey.bytes);
1825 MD5Update(&md5c, pktin.body, 8);
1826 MD5Final(session_id, &md5c);
1828 for (i = 0; i < 32; i++)
1829 session_key[i] = random_byte();
1831 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1833 rsabuf = smalloc(len);
1835 fatalbox("Out of memory");
1838 * Verify the host key.
1842 * First format the key into a string.
1844 int len = rsastr_len(&hostkey);
1845 char fingerprint[100];
1846 char *keystr = smalloc(len);
1848 fatalbox("Out of memory");
1849 rsastr_fmt(keystr, &hostkey);
1850 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1851 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1856 for (i = 0; i < 32; i++) {
1857 rsabuf[i] = session_key[i];
1859 rsabuf[i] ^= session_id[i];
1862 if (hostkey.bytes > servkey.bytes) {
1863 rsaencrypt(rsabuf, 32, &servkey);
1864 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1866 rsaencrypt(rsabuf, 32, &hostkey);
1867 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1870 logevent("Encrypted session key");
1873 int cipher_chosen = 0, warn = 0;
1874 char *cipher_string = NULL;
1875 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
1876 int next_cipher = cfg.ssh_cipherlist[i];
1877 if (next_cipher == CIPHER_WARN) {
1878 /* If/when we choose a cipher, warn about it */
1880 } else if (next_cipher == CIPHER_AES) {
1881 /* XXX Probably don't need to mention this. */
1882 logevent("AES not supported in SSH1, skipping");
1884 switch (next_cipher) {
1885 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
1886 cipher_string = "3DES"; break;
1887 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
1888 cipher_string = "Blowfish"; break;
1889 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
1890 cipher_string = "single-DES"; break;
1892 if (supported_ciphers_mask & (1 << cipher_type))
1896 if (!cipher_chosen) {
1897 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
1898 bombout(("Server violates SSH 1 protocol by not "
1899 "supporting 3DES encryption"));
1901 /* shouldn't happen */
1902 bombout(("No supported ciphers found"));
1906 /* Warn about chosen cipher if necessary. */
1908 askcipher(cipher_string, 0);
1911 switch (cipher_type) {
1912 case SSH_CIPHER_3DES:
1913 logevent("Using 3DES encryption");
1915 case SSH_CIPHER_DES:
1916 logevent("Using single-DES encryption");
1918 case SSH_CIPHER_BLOWFISH:
1919 logevent("Using Blowfish encryption");
1923 send_packet(SSH1_CMSG_SESSION_KEY,
1924 PKT_CHAR, cipher_type,
1925 PKT_DATA, cookie, 8,
1926 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1927 PKT_DATA, rsabuf, len,
1928 PKT_INT, ssh1_local_protoflags, PKT_END);
1930 logevent("Trying to enable encryption...");
1934 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1935 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
1936 cipher->sesskey(session_key);
1940 if (pktin.type != SSH1_SMSG_SUCCESS) {
1941 bombout(("Encryption not successfully enabled"));
1945 logevent("Successfully started encryption");
1951 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1953 if (!ssh_get_line("login as: ",
1954 username, sizeof(username), FALSE)) {
1956 * get_line failed to get a username.
1959 logevent("No username provided. Abandoning session.");
1960 ssh_state = SSH_STATE_CLOSED;
1964 c_write_str("login as: ");
1967 crWaitUntil(!ispkt);
1969 switch (c = *in++) {
1978 c_write_str("\b \b");
1985 c_write_str("\b \b");
1995 if (((c >= ' ' && c <= '~') ||
1996 ((unsigned char) c >= 160))
1997 && pos < sizeof(username)-1) {
1998 username[pos++] = c;
2004 c_write_str("\r\n");
2005 username[strcspn(username, "\n\r")] = '\0';
2008 strncpy(username, cfg.username, 99);
2009 username[99] = '\0';
2012 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2014 char userlog[22 + sizeof(username)];
2015 sprintf(userlog, "Sent username \"%s\"", username);
2017 if (flags & FLAG_INTERACTIVE &&
2018 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2019 strcat(userlog, "\r\n");
2020 c_write_str(userlog);
2027 tried_publickey = 0;
2029 while (pktin.type == SSH1_SMSG_FAILURE) {
2030 static char password[100];
2031 static char prompt[200];
2034 static int pwpkt_type;
2036 * Show password prompt, having first obtained it via a TIS
2037 * or CryptoCard exchange if we're doing TIS or CryptoCard
2040 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2041 if (agent_exists()) {
2043 * Attempt RSA authentication using Pageant.
2045 static unsigned char request[5], *response, *p;
2046 static int responselen;
2047 static int i, nkeys;
2048 static int authed = FALSE;
2051 logevent("Pageant is running. Requesting keys.");
2053 /* Request the keys held by the agent. */
2054 PUT_32BIT(request, 1);
2055 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2056 agent_query(request, 5, &r, &responselen);
2057 response = (unsigned char *) r;
2058 if (response && responselen >= 5 &&
2059 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2061 nkeys = GET_32BIT(p);
2065 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2068 for (i = 0; i < nkeys; i++) {
2069 static struct RSAKey key;
2070 static Bignum challenge;
2071 static char *commentp;
2072 static int commentlen;
2076 sprintf(buf, "Trying Pageant key #%d", i);
2080 p += ssh1_read_bignum(p, &key.exponent);
2081 p += ssh1_read_bignum(p, &key.modulus);
2082 commentlen = GET_32BIT(p);
2086 send_packet(SSH1_CMSG_AUTH_RSA,
2087 PKT_BIGNUM, key.modulus, PKT_END);
2089 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2090 logevent("Key refused");
2093 logevent("Received RSA challenge");
2094 ssh1_read_bignum(pktin.body, &challenge);
2096 char *agentreq, *q, *ret;
2099 len = 1 + 4; /* message type, bit count */
2100 len += ssh1_bignum_length(key.exponent);
2101 len += ssh1_bignum_length(key.modulus);
2102 len += ssh1_bignum_length(challenge);
2103 len += 16; /* session id */
2104 len += 4; /* response format */
2105 agentreq = smalloc(4 + len);
2106 PUT_32BIT(agentreq, len);
2108 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2109 PUT_32BIT(q, bignum_bitcount(key.modulus));
2111 q += ssh1_write_bignum(q, key.exponent);
2112 q += ssh1_write_bignum(q, key.modulus);
2113 q += ssh1_write_bignum(q, challenge);
2114 memcpy(q, session_id, 16);
2116 PUT_32BIT(q, 1); /* response format */
2117 agent_query(agentreq, len + 4, &vret, &retlen);
2121 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2122 logevent("Sending Pageant's response");
2123 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2124 PKT_DATA, ret + 5, 16,
2128 if (pktin.type == SSH1_SMSG_SUCCESS) {
2130 ("Pageant's response accepted");
2131 if (flags & FLAG_VERBOSE) {
2133 ("Authenticated using RSA key \"");
2134 c_write(commentp, commentlen);
2135 c_write_str("\" from agent\r\n");
2140 ("Pageant's response not accepted");
2143 ("Pageant failed to answer challenge");
2147 logevent("No reply received from Pageant");
2150 freebn(key.exponent);
2151 freebn(key.modulus);
2160 if (*cfg.keyfile && !tried_publickey)
2161 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2163 if (pktin.type == SSH1_SMSG_FAILURE &&
2165 (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
2166 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2167 logevent("Requested TIS authentication");
2168 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2170 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2171 logevent("TIS authentication declined");
2172 if (flags & FLAG_INTERACTIVE)
2173 c_write_str("TIS authentication refused.\r\n");
2175 int challengelen = ((pktin.body[0] << 24) |
2176 (pktin.body[1] << 16) |
2177 (pktin.body[2] << 8) |
2179 logevent("Received TIS challenge");
2180 if (challengelen > sizeof(prompt) - 1)
2181 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2182 memcpy(prompt, pktin.body + 4, challengelen);
2183 prompt[challengelen] = '\0';
2186 if (pktin.type == SSH1_SMSG_FAILURE &&
2188 (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
2189 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2190 logevent("Requested CryptoCard authentication");
2191 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2193 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2194 logevent("CryptoCard authentication declined");
2195 c_write_str("CryptoCard authentication refused.\r\n");
2197 int challengelen = ((pktin.body[0] << 24) |
2198 (pktin.body[1] << 16) |
2199 (pktin.body[2] << 8) |
2201 logevent("Received CryptoCard challenge");
2202 if (challengelen > sizeof(prompt) - 1)
2203 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2204 memcpy(prompt, pktin.body + 4, challengelen);
2205 strncpy(prompt + challengelen, "\r\nResponse : ",
2206 sizeof(prompt) - challengelen);
2207 prompt[sizeof(prompt) - 1] = '\0';
2210 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2211 sprintf(prompt, "%.90s@%.90s's password: ",
2212 username, savedhost);
2214 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2215 char *comment = NULL;
2216 if (flags & FLAG_VERBOSE)
2217 c_write_str("Trying public key authentication.\r\n");
2218 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2219 if (flags & FLAG_VERBOSE)
2220 c_write_str("No passphrase required.\r\n");
2223 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2228 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2230 * get_line failed to get a password (for example
2231 * because one was supplied on the command line
2232 * which has already failed to work). Terminate.
2234 send_packet(SSH1_MSG_DISCONNECT,
2235 PKT_STR, "No more passwords available to try",
2237 connection_fatal("Unable to authenticate");
2238 ssh_state = SSH_STATE_CLOSED;
2242 c_write_str(prompt);
2246 crWaitUntil(!ispkt);
2248 switch (c = *in++) {
2269 if (pos < sizeof(password)-1)
2270 password[pos++] = c;
2274 c_write_str("\r\n");
2278 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2280 * Try public key authentication with the specified
2283 static struct RSAKey pubkey;
2284 static Bignum challenge, response;
2286 static unsigned char buffer[32];
2288 tried_publickey = 1;
2289 i = loadrsakey(cfg.keyfile, &pubkey, password);
2291 c_write_str("Couldn't load public key from ");
2292 c_write_str(cfg.keyfile);
2293 c_write_str(".\r\n");
2294 continue; /* go and try password */
2297 c_write_str("Wrong passphrase.\r\n");
2298 tried_publickey = 0;
2299 continue; /* try again */
2303 * Send a public key attempt.
2305 send_packet(SSH1_CMSG_AUTH_RSA,
2306 PKT_BIGNUM, pubkey.modulus, PKT_END);
2309 if (pktin.type == SSH1_SMSG_FAILURE) {
2310 c_write_str("Server refused our public key.\r\n");
2311 continue; /* go and try password */
2313 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2314 bombout(("Bizarre response to offer of public key"));
2317 ssh1_read_bignum(pktin.body, &challenge);
2318 response = rsadecrypt(challenge, &pubkey);
2319 freebn(pubkey.private_exponent); /* burn the evidence */
2321 for (i = 0; i < 32; i++) {
2322 buffer[i] = bignum_byte(response, 31 - i);
2326 MD5Update(&md5c, buffer, 32);
2327 MD5Update(&md5c, session_id, 16);
2328 MD5Final(buffer, &md5c);
2330 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2331 PKT_DATA, buffer, 16, PKT_END);
2334 if (pktin.type == SSH1_SMSG_FAILURE) {
2335 if (flags & FLAG_VERBOSE)
2337 ("Failed to authenticate with our public key.\r\n");
2338 continue; /* go and try password */
2339 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2341 ("Bizarre response to RSA authentication response"));
2345 break; /* we're through! */
2347 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2349 * Defence against traffic analysis: we send a
2350 * whole bunch of packets containing strings of
2351 * different lengths. One of these strings is the
2352 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2353 * The others are all random data in
2354 * SSH1_MSG_IGNORE packets. This way a passive
2355 * listener can't tell which is the password, and
2356 * hence can't deduce the password length.
2358 * Anybody with a password length greater than 16
2359 * bytes is going to have enough entropy in their
2360 * password that a listener won't find it _that_
2361 * much help to know how long it is. So what we'll
2364 * - if password length < 16, we send 15 packets
2365 * containing string lengths 1 through 15
2367 * - otherwise, we let N be the nearest multiple
2368 * of 8 below the password length, and send 8
2369 * packets containing string lengths N through
2370 * N+7. This won't obscure the order of
2371 * magnitude of the password length, but it will
2372 * introduce a bit of extra uncertainty.
2374 * A few servers (the old 1.2.18 through 1.2.22)
2375 * can't deal with SSH1_MSG_IGNORE. For these
2376 * servers, we need an alternative defence. We make
2377 * use of the fact that the password is interpreted
2378 * as a C string: so we can append a NUL, then some
2381 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2386 len = strlen(password);
2387 if (len < sizeof(string)) {
2389 strcpy(string, password);
2390 len++; /* cover the zero byte */
2391 while (len < sizeof(string)) {
2392 string[len++] = (char) random_byte();
2397 send_packet(pwpkt_type, PKT_INT, len,
2398 PKT_DATA, s, len, PKT_END);
2400 int bottom, top, pwlen, i;
2403 pwlen = strlen(password);
2405 bottom = 0; /* zero length passwords are OK! :-) */
2408 bottom = pwlen & ~7;
2412 assert(pwlen >= bottom && pwlen <= top);
2414 randomstr = smalloc(top + 1);
2416 for (i = bottom; i <= top; i++) {
2418 defer_packet(pwpkt_type, PKT_STR, password,
2421 for (j = 0; j < i; j++) {
2423 randomstr[j] = random_byte();
2424 } while (randomstr[j] == '\0');
2426 randomstr[i] = '\0';
2427 defer_packet(SSH1_MSG_IGNORE,
2428 PKT_STR, randomstr, PKT_END);
2431 ssh_pkt_defersend();
2434 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2437 logevent("Sent password");
2438 memset(password, 0, strlen(password));
2440 if (pktin.type == SSH1_SMSG_FAILURE) {
2441 if (flags & FLAG_VERBOSE)
2442 c_write_str("Access denied\r\n");
2443 logevent("Authentication refused");
2444 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2445 logevent("Received disconnect request");
2446 ssh_state = SSH_STATE_CLOSED;
2448 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2449 bombout(("Strange packet received, type %d", pktin.type));
2454 logevent("Authentication successful");
2459 void sshfwd_close(struct ssh_channel *c)
2461 if (c && !c->closes) {
2462 if (ssh_version == 1) {
2463 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2466 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2467 ssh2_pkt_adduint32(c->remoteid);
2471 if (c->type == CHAN_X11) {
2473 logevent("Forwarded X11 connection terminated");
2474 } else if (c->type == CHAN_SOCKDATA) {
2476 logevent("Forwarded port closed");
2481 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2483 if (ssh_version == 1) {
2484 send_packet(SSH1_MSG_CHANNEL_DATA,
2485 PKT_INT, c->remoteid,
2486 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2488 * In SSH1 we can return 0 here - implying that forwarded
2489 * connections are never individually throttled - because
2490 * the only circumstance that can cause throttling will be
2491 * the whole SSH connection backing up, in which case
2492 * _everything_ will be throttled as a whole.
2496 ssh2_add_channel_data(c, buf, len);
2497 return ssh2_try_send(c);
2501 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2503 if (ssh_version == 1) {
2504 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2505 c->v.v1.throttling = 0;
2509 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2513 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2519 while (!do_ssh1_login(in, inlen, ispkt)) {
2522 if (ssh_state == SSH_STATE_CLOSED)
2525 if (cfg.agentfwd && agent_exists()) {
2526 logevent("Requesting agent forwarding");
2527 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2531 if (pktin.type != SSH1_SMSG_SUCCESS
2532 && pktin.type != SSH1_SMSG_FAILURE) {
2533 bombout(("Protocol confusion"));
2535 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2536 logevent("Agent forwarding refused");
2538 logevent("Agent forwarding enabled");
2539 ssh_agentfwd_enabled = TRUE;
2543 if (cfg.x11_forward) {
2544 char proto[20], data[64];
2545 logevent("Requesting X11 forwarding");
2546 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2547 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2548 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2549 PKT_STR, proto, PKT_STR, data,
2550 PKT_INT, 0, PKT_END);
2552 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2553 PKT_STR, proto, PKT_STR, data, PKT_END);
2558 if (pktin.type != SSH1_SMSG_SUCCESS
2559 && pktin.type != SSH1_SMSG_FAILURE) {
2560 bombout(("Protocol confusion"));
2562 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2563 logevent("X11 forwarding refused");
2565 logevent("X11 forwarding enabled");
2566 ssh_X11_fwd_enabled = TRUE;
2574 char sports[256], dports[256], host[256];
2577 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2578 /* Add port forwardings. */
2583 while (*e && *e != '\t')
2589 while (*e && *e != ':')
2599 dport = atoi(dports);
2600 sport = atoi(sports);
2601 if (sport && dport) {
2603 pfd_addforward(host, dport, sport);
2604 sprintf(buf, "Local port %d forwarding to %s:%d",
2605 sport, host, dport);
2608 struct ssh_rportfwd *pf;
2609 pf = smalloc(sizeof(*pf));
2610 strcpy(pf->dhost, host);
2612 if (add234(ssh_rportfwds, pf) != pf) {
2614 "Duplicate remote port forwarding to %s:%d",
2619 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2620 sport, host, dport);
2622 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2634 send_packet(SSH1_CMSG_REQUEST_PTY,
2635 PKT_STR, cfg.termtype,
2636 PKT_INT, rows, PKT_INT, cols,
2637 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2638 ssh_state = SSH_STATE_INTERMED;
2642 if (pktin.type != SSH1_SMSG_SUCCESS
2643 && pktin.type != SSH1_SMSG_FAILURE) {
2644 bombout(("Protocol confusion"));
2646 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2647 c_write_str("Server refused to allocate pty\r\n");
2648 ssh_editing = ssh_echoing = 1;
2650 logevent("Allocated pty");
2652 ssh_editing = ssh_echoing = 1;
2655 if (cfg.compression) {
2656 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2660 if (pktin.type != SSH1_SMSG_SUCCESS
2661 && pktin.type != SSH1_SMSG_FAILURE) {
2662 bombout(("Protocol confusion"));
2664 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2665 c_write_str("Server refused to compress\r\n");
2667 logevent("Started compression");
2668 ssh1_compressing = TRUE;
2669 zlib_compress_init();
2670 zlib_decompress_init();
2674 * Start the shell or command.
2676 * Special case: if the first-choice command is an SSH2
2677 * subsystem (hence not usable here) and the second choice
2678 * exists, we fall straight back to that.
2681 char *cmd = cfg.remote_cmd_ptr;
2683 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
2684 cmd = cfg.remote_cmd_ptr2;
2685 ssh_fallback_cmd = TRUE;
2688 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2690 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2691 logevent("Started session");
2694 ssh_state = SSH_STATE_SESSION;
2698 ssh_special(TS_EOF);
2700 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2702 ssh_channels = newtree234(ssh_channelcmp);
2706 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2707 pktin.type == SSH1_SMSG_STDERR_DATA) {
2708 long len = GET_32BIT(pktin.body);
2710 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2711 pktin.body + 4, len);
2712 if (bufsize > SSH1_BUFFER_LIMIT) {
2713 ssh1_stdout_throttling = 1;
2716 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2717 ssh_state = SSH_STATE_CLOSED;
2718 logevent("Received disconnect request");
2720 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2721 /* Remote side is trying to open a channel to talk to our
2722 * X-Server. Give them back a local channel number. */
2723 struct ssh_channel *c;
2725 logevent("Received X11 connect request");
2726 /* Refuse if X11 forwarding is disabled. */
2727 if (!ssh_X11_fwd_enabled) {
2728 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2729 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2730 logevent("Rejected X11 connect request");
2732 c = smalloc(sizeof(struct ssh_channel));
2734 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2735 logevent("opening X11 forward connection failed");
2737 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2738 PKT_INT, GET_32BIT(pktin.body),
2742 ("opening X11 forward connection succeeded");
2743 c->remoteid = GET_32BIT(pktin.body);
2744 c->localid = alloc_channel_id();
2746 c->v.v1.throttling = 0;
2747 c->type = CHAN_X11; /* identify channel type */
2748 add234(ssh_channels, c);
2749 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2750 PKT_INT, c->remoteid, PKT_INT,
2751 c->localid, PKT_END);
2752 logevent("Opened X11 forward channel");
2755 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2756 /* Remote side is trying to open a channel to talk to our
2757 * agent. Give them back a local channel number. */
2758 struct ssh_channel *c;
2760 /* Refuse if agent forwarding is disabled. */
2761 if (!ssh_agentfwd_enabled) {
2762 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2763 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2765 c = smalloc(sizeof(struct ssh_channel));
2766 c->remoteid = GET_32BIT(pktin.body);
2767 c->localid = alloc_channel_id();
2769 c->v.v1.throttling = 0;
2770 c->type = CHAN_AGENT; /* identify channel type */
2771 c->u.a.lensofar = 0;
2772 add234(ssh_channels, c);
2773 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2774 PKT_INT, c->remoteid, PKT_INT, c->localid,
2777 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2778 /* Remote side is trying to open a channel to talk to a
2779 * forwarded port. Give them back a local channel number. */
2780 struct ssh_channel *c;
2781 struct ssh_rportfwd pf;
2783 char host[256], buf[1024];
2785 c = smalloc(sizeof(struct ssh_channel));
2787 hostsize = GET_32BIT(pktin.body+4);
2788 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2789 if (h+1 < host+sizeof(host))
2794 port = GET_32BIT(p);
2796 strcpy(pf.dhost, host);
2799 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2800 sprintf(buf, "Rejected remote port open request for %s:%d",
2803 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2804 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2806 sprintf(buf, "Received remote port open request for %s:%d",
2809 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2812 sprintf(buf, "Port open failed: %s", e);
2815 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2816 PKT_INT, GET_32BIT(pktin.body),
2819 c->remoteid = GET_32BIT(pktin.body);
2820 c->localid = alloc_channel_id();
2822 c->v.v1.throttling = 0;
2823 c->type = CHAN_SOCKDATA; /* identify channel type */
2824 add234(ssh_channels, c);
2825 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2826 PKT_INT, c->remoteid, PKT_INT,
2827 c->localid, PKT_END);
2828 logevent("Forwarded port opened successfully");
2832 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
2833 unsigned int remoteid = GET_32BIT(pktin.body);
2834 unsigned int localid = GET_32BIT(pktin.body+4);
2835 struct ssh_channel *c;
2837 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2838 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2839 c->remoteid = localid;
2840 c->type = CHAN_SOCKDATA;
2841 pfd_confirm(c->u.pfd.s);
2844 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2845 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2846 /* Remote side closes a channel. */
2847 unsigned i = GET_32BIT(pktin.body);
2848 struct ssh_channel *c;
2849 c = find234(ssh_channels, &i, ssh_channelfind);
2853 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2854 if (!(c->closes & closetype))
2855 send_packet(pktin.type, PKT_INT, c->remoteid,
2857 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2858 logevent("Forwarded X11 connection terminated");
2859 assert(c->u.x11.s != NULL);
2860 x11_close(c->u.x11.s);
2863 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
2864 logevent("Forwarded port closed");
2865 assert(c->u.pfd.s != NULL);
2866 pfd_close(c->u.pfd.s);
2869 c->closes |= closetype;
2870 if (c->closes == 3) {
2871 del234(ssh_channels, c);
2875 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2876 /* Data sent down one of our channels. */
2877 int i = GET_32BIT(pktin.body);
2878 int len = GET_32BIT(pktin.body + 4);
2879 unsigned char *p = pktin.body + 8;
2880 struct ssh_channel *c;
2881 c = find234(ssh_channels, &i, ssh_channelfind);
2886 bufsize = x11_send(c->u.x11.s, p, len);
2889 bufsize = pfd_send(c->u.pfd.s, p, len);
2892 /* Data for an agent message. Buffer it. */
2894 if (c->u.a.lensofar < 4) {
2895 int l = min(4 - c->u.a.lensofar, len);
2896 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2900 c->u.a.lensofar += l;
2902 if (c->u.a.lensofar == 4) {
2904 4 + GET_32BIT(c->u.a.msglen);
2905 c->u.a.message = smalloc(c->u.a.totallen);
2906 memcpy(c->u.a.message, c->u.a.msglen, 4);
2908 if (c->u.a.lensofar >= 4 && len > 0) {
2910 min(c->u.a.totallen - c->u.a.lensofar,
2912 memcpy(c->u.a.message + c->u.a.lensofar, p,
2916 c->u.a.lensofar += l;
2918 if (c->u.a.lensofar == c->u.a.totallen) {
2919 void *reply, *sentreply;
2921 agent_query(c->u.a.message,
2922 c->u.a.totallen, &reply,
2927 /* Fake SSH_AGENT_FAILURE. */
2928 sentreply = "\0\0\0\1\5";
2931 send_packet(SSH1_MSG_CHANNEL_DATA,
2932 PKT_INT, c->remoteid,
2934 PKT_DATA, sentreply, replylen,
2938 sfree(c->u.a.message);
2939 c->u.a.lensofar = 0;
2942 bufsize = 0; /* agent channels never back up */
2945 if (bufsize > SSH1_BUFFER_LIMIT) {
2946 c->v.v1.throttling = 1;
2950 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2951 /* may be from EXEC_SHELL on some servers */
2952 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2953 /* may be from EXEC_SHELL on some servers
2954 * if no pty is available or in other odd cases. Ignore */
2955 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2956 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2958 bombout(("Strange packet received: type %d", pktin.type));
2963 int len = min(inlen, 512);
2964 send_packet(SSH1_CMSG_STDIN_DATA,
2965 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2976 * Utility routine for decoding comma-separated strings in KEXINIT.
2978 static int in_commasep_string(char *needle, char *haystack, int haylen)
2980 int needlen = strlen(needle);
2983 * Is it at the start of the string?
2985 if (haylen >= needlen && /* haystack is long enough */
2986 !memcmp(needle, haystack, needlen) && /* initial match */
2987 (haylen == needlen || haystack[needlen] == ',')
2988 /* either , or EOS follows */
2992 * If not, search for the next comma and resume after that.
2993 * If no comma found, terminate.
2995 while (haylen > 0 && *haystack != ',')
2996 haylen--, haystack++;
2999 haylen--, haystack++; /* skip over comma itself */
3004 * SSH2 key creation method.
3006 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3010 /* First 20 bytes. */
3013 SHA_Bytes(&s, H, 20);
3014 SHA_Bytes(&s, &chr, 1);
3015 SHA_Bytes(&s, sessid, 20);
3016 SHA_Final(&s, keyspace);
3017 /* Next 20 bytes. */
3020 SHA_Bytes(&s, H, 20);
3021 SHA_Bytes(&s, keyspace, 20);
3022 SHA_Final(&s, keyspace + 20);
3026 * Handle the SSH2 transport layer.
3028 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3030 static int i, j, len, nbits, pbits, warn;
3032 static Bignum p, g, e, f, K;
3033 static int kex_init_value, kex_reply_value;
3034 static const struct ssh_mac **maclist;
3036 static const struct ssh2_cipher *cscipher_tobe = NULL;
3037 static const struct ssh2_cipher *sccipher_tobe = NULL;
3038 static const struct ssh_mac *csmac_tobe = NULL;
3039 static const struct ssh_mac *scmac_tobe = NULL;
3040 static const struct ssh_compress *cscomp_tobe = NULL;
3041 static const struct ssh_compress *sccomp_tobe = NULL;
3042 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3043 static int hostkeylen, siglen;
3044 static void *hkey; /* actual host key */
3045 static unsigned char exchange_hash[20];
3046 static unsigned char keyspace[40];
3047 static int n_preferred_ciphers;
3048 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3049 static const struct ssh_compress *preferred_comp;
3050 static int first_kex;
3057 * Set up the preferred ciphers. (NULL => warn below here)
3059 n_preferred_ciphers = 0;
3060 for (i = 0; i < CIPHER_MAX; i++) {
3061 switch (cfg.ssh_cipherlist[i]) {
3062 case CIPHER_BLOWFISH:
3063 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3064 n_preferred_ciphers++;
3067 /* Not supported in SSH2; silently drop */
3070 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3071 n_preferred_ciphers++;
3074 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3075 n_preferred_ciphers++;
3078 /* Flag for later. Don't bother if it's the last in
3080 if (i < CIPHER_MAX - 1) {
3081 preferred_ciphers[n_preferred_ciphers] = NULL;
3082 n_preferred_ciphers++;
3089 * Set up preferred compression.
3091 if (cfg.compression)
3092 preferred_comp = &ssh_zlib;
3094 preferred_comp = &ssh_comp_none;
3097 * Be prepared to work around the buggy MAC problem.
3099 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3100 maclist = buggymacs, nmacs = lenof(buggymacs);
3102 maclist = macs, nmacs = lenof(macs);
3106 * Construct and send our key exchange packet.
3108 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3109 for (i = 0; i < 16; i++)
3110 ssh2_pkt_addbyte((unsigned char) random_byte());
3111 /* List key exchange algorithms. */
3112 ssh2_pkt_addstring_start();
3113 for (i = 0; i < lenof(kex_algs); i++) {
3114 ssh2_pkt_addstring_str(kex_algs[i]->name);
3115 if (i < lenof(kex_algs) - 1)
3116 ssh2_pkt_addstring_str(",");
3118 /* List server host key algorithms. */
3119 ssh2_pkt_addstring_start();
3120 for (i = 0; i < lenof(hostkey_algs); i++) {
3121 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3122 if (i < lenof(hostkey_algs) - 1)
3123 ssh2_pkt_addstring_str(",");
3125 /* List client->server encryption algorithms. */
3126 ssh2_pkt_addstring_start();
3127 for (i = 0; i < n_preferred_ciphers; i++) {
3128 const struct ssh2_ciphers *c = preferred_ciphers[i];
3129 if (!c) continue; /* warning flag */
3130 for (j = 0; j < c->nciphers; j++) {
3131 ssh2_pkt_addstring_str(c->list[j]->name);
3132 if (i < n_preferred_ciphers || j < c->nciphers - 1)
3133 ssh2_pkt_addstring_str(",");
3136 /* List server->client encryption algorithms. */
3137 ssh2_pkt_addstring_start();
3138 for (i = 0; i < n_preferred_ciphers; i++) {
3139 const struct ssh2_ciphers *c = preferred_ciphers[i];
3140 if (!c) continue; /* warning flag */
3141 for (j = 0; j < c->nciphers; j++) {
3142 ssh2_pkt_addstring_str(c->list[j]->name);
3143 if (i < n_preferred_ciphers || j < c->nciphers - 1)
3144 ssh2_pkt_addstring_str(",");
3147 /* List client->server MAC algorithms. */
3148 ssh2_pkt_addstring_start();
3149 for (i = 0; i < nmacs; i++) {
3150 ssh2_pkt_addstring_str(maclist[i]->name);
3152 ssh2_pkt_addstring_str(",");
3154 /* List server->client MAC algorithms. */
3155 ssh2_pkt_addstring_start();
3156 for (i = 0; i < nmacs; i++) {
3157 ssh2_pkt_addstring_str(maclist[i]->name);
3159 ssh2_pkt_addstring_str(",");
3161 /* List client->server compression algorithms. */
3162 ssh2_pkt_addstring_start();
3163 for (i = 0; i < lenof(compressions) + 1; i++) {
3164 const struct ssh_compress *c =
3165 i == 0 ? preferred_comp : compressions[i - 1];
3166 ssh2_pkt_addstring_str(c->name);
3167 if (i < lenof(compressions))
3168 ssh2_pkt_addstring_str(",");
3170 /* List server->client compression algorithms. */
3171 ssh2_pkt_addstring_start();
3172 for (i = 0; i < lenof(compressions) + 1; i++) {
3173 const struct ssh_compress *c =
3174 i == 0 ? preferred_comp : compressions[i - 1];
3175 ssh2_pkt_addstring_str(c->name);
3176 if (i < lenof(compressions))
3177 ssh2_pkt_addstring_str(",");
3179 /* List client->server languages. Empty list. */
3180 ssh2_pkt_addstring_start();
3181 /* List server->client languages. Empty list. */
3182 ssh2_pkt_addstring_start();
3183 /* First KEX packet does _not_ follow, because we're not that brave. */
3184 ssh2_pkt_addbool(FALSE);
3186 ssh2_pkt_adduint32(0);
3188 exhash = exhashbase;
3189 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3195 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3198 * Now examine the other side's KEXINIT to see what we're up
3201 if (pktin.type != SSH2_MSG_KEXINIT) {
3202 bombout(("expected key exchange packet from server"));
3207 cscipher_tobe = NULL;
3208 sccipher_tobe = NULL;
3213 pktin.savedpos += 16; /* skip garbage cookie */
3214 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3215 for (i = 0; i < lenof(kex_algs); i++) {
3216 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3221 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3222 for (i = 0; i < lenof(hostkey_algs); i++) {
3223 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3224 hostkey = hostkey_algs[i];
3228 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3230 for (i = 0; i < n_preferred_ciphers; i++) {
3231 const struct ssh2_ciphers *c = preferred_ciphers[i];
3235 for (j = 0; j < c->nciphers; j++) {
3236 if (in_commasep_string(c->list[j]->name, str, len)) {
3237 cscipher_tobe = c->list[j];
3242 if (cscipher_tobe) {
3244 askcipher(cscipher_tobe->name, 1);
3248 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3250 for (i = 0; i < n_preferred_ciphers; i++) {
3251 const struct ssh2_ciphers *c = preferred_ciphers[i];
3255 for (j = 0; j < c->nciphers; j++) {
3256 if (in_commasep_string(c->list[j]->name, str, len)) {
3257 sccipher_tobe = c->list[j];
3262 if (sccipher_tobe) {
3264 askcipher(sccipher_tobe->name, 2);
3268 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3269 for (i = 0; i < nmacs; i++) {
3270 if (in_commasep_string(maclist[i]->name, str, len)) {
3271 csmac_tobe = maclist[i];
3275 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3276 for (i = 0; i < nmacs; i++) {
3277 if (in_commasep_string(maclist[i]->name, str, len)) {
3278 scmac_tobe = maclist[i];
3282 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3283 for (i = 0; i < lenof(compressions) + 1; i++) {
3284 const struct ssh_compress *c =
3285 i == 0 ? preferred_comp : compressions[i - 1];
3286 if (in_commasep_string(c->name, str, len)) {
3291 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3292 for (i = 0; i < lenof(compressions) + 1; i++) {
3293 const struct ssh_compress *c =
3294 i == 0 ? preferred_comp : compressions[i - 1];
3295 if (in_commasep_string(c->name, str, len)) {
3302 * Work out the number of bits of key we will need from the key
3303 * exchange. We start with the maximum key length of either
3309 csbits = cscipher_tobe->keylen;
3310 scbits = sccipher_tobe->keylen;
3311 nbits = (csbits > scbits ? csbits : scbits);
3313 /* The keys only have 160-bit entropy, since they're based on
3314 * a SHA-1 hash. So cap the key size at 160 bits. */
3319 * If we're doing Diffie-Hellman group exchange, start by
3320 * requesting a group.
3322 if (kex == &ssh_diffiehellman_gex) {
3323 logevent("Doing Diffie-Hellman group exchange");
3325 * Work out how big a DH group we will need to allow that
3328 pbits = 512 << ((nbits - 1) / 64);
3329 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3330 ssh2_pkt_adduint32(pbits);
3334 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3335 bombout(("expected key exchange group packet from server"));
3338 p = ssh2_pkt_getmp();
3339 g = ssh2_pkt_getmp();
3340 dh_setup_group(p, g);
3341 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3342 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3345 kex_init_value = SSH2_MSG_KEXDH_INIT;
3346 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3349 logevent("Doing Diffie-Hellman key exchange");
3351 * Now generate and send e for Diffie-Hellman.
3353 e = dh_create_e(nbits * 2);
3354 ssh2_pkt_init(kex_init_value);
3359 if (pktin.type != kex_reply_value) {
3360 bombout(("expected key exchange reply packet from server"));
3363 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3364 f = ssh2_pkt_getmp();
3365 ssh2_pkt_getstring(&sigdata, &siglen);
3369 sha_string(&exhash, hostkeydata, hostkeylen);
3370 if (kex == &ssh_diffiehellman_gex) {
3371 sha_uint32(&exhash, pbits);
3372 sha_mpint(&exhash, p);
3373 sha_mpint(&exhash, g);
3375 sha_mpint(&exhash, e);
3376 sha_mpint(&exhash, f);
3377 sha_mpint(&exhash, K);
3378 SHA_Final(&exhash, exchange_hash);
3383 debug(("Exchange hash is:\n"));
3384 dmemdump(exchange_hash, 20);
3387 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3389 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3390 bombout(("Server's host key did not match the signature supplied"));
3395 * Expect SSH2_MSG_NEWKEYS from server.
3398 if (pktin.type != SSH2_MSG_NEWKEYS) {
3399 bombout(("expected new-keys packet from server"));
3404 * Authenticate remote host: verify host key. (We've already
3405 * checked the signature of the exchange hash.)
3407 keystr = hostkey->fmtkey(hkey);
3408 fingerprint = hostkey->fingerprint(hkey);
3409 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3410 keystr, fingerprint);
3411 if (first_kex) { /* don't bother logging this in rekeys */
3412 logevent("Host key fingerprint is:");
3413 logevent(fingerprint);
3417 hostkey->freekey(hkey);
3420 * Send SSH2_MSG_NEWKEYS.
3422 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3426 * Create and initialise session keys.
3428 cscipher = cscipher_tobe;
3429 sccipher = sccipher_tobe;
3432 cscomp = cscomp_tobe;
3433 sccomp = sccomp_tobe;
3434 cscomp->compress_init();
3435 sccomp->decompress_init();
3437 * Set IVs after keys. Here we use the exchange hash from the
3438 * _first_ key exchange.
3441 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3442 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3443 cscipher->setcskey(keyspace);
3444 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3445 sccipher->setsckey(keyspace);
3446 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3447 cscipher->setcsiv(keyspace);
3448 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3449 sccipher->setsciv(keyspace);
3450 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3451 csmac->setcskey(keyspace);
3452 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3453 scmac->setsckey(keyspace);
3456 * If this is the first key exchange phase, we must pass the
3457 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3458 * wants to see it but because it will need time to initialise
3459 * itself before it sees an actual packet. In subsequent key
3460 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3461 * it would only confuse the layer above.
3469 * Now we're encrypting. Begin returning 1 to the protocol main
3470 * function so that other things can run on top of the
3471 * transport. If we ever see a KEXINIT, we must go back to the
3474 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3477 logevent("Server initiated key re-exchange");
3478 goto begin_key_exchange;
3484 * Add data to an SSH2 channel output buffer.
3486 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3489 bufchain_add(&c->v.v2.outbuffer, buf, len);
3493 * Attempt to send data on an SSH2 channel.
3495 static int ssh2_try_send(struct ssh_channel *c)
3497 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3500 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3501 if ((unsigned)len > c->v.v2.remwindow)
3502 len = c->v.v2.remwindow;
3503 if ((unsigned)len > c->v.v2.remmaxpkt)
3504 len = c->v.v2.remmaxpkt;
3505 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3506 ssh2_pkt_adduint32(c->remoteid);
3507 ssh2_pkt_addstring_start();
3508 ssh2_pkt_addstring_data(data, len);
3510 bufchain_consume(&c->v.v2.outbuffer, len);
3511 c->v.v2.remwindow -= len;
3515 * After having sent as much data as we can, return the amount
3518 return bufchain_size(&c->v.v2.outbuffer);
3522 * Potentially enlarge the window on an SSH2 channel.
3524 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3526 if (newwin > c->v.v2.locwindow) {
3527 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3528 ssh2_pkt_adduint32(c->remoteid);
3529 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
3531 c->v.v2.locwindow = newwin;
3536 * Handle the SSH2 userauth and connection layers.
3538 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3541 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3543 AUTH_KEYBOARD_INTERACTIVE
3547 AUTH_TYPE_PUBLICKEY,
3548 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3549 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3551 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3552 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3554 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3555 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
3556 static int kbd_inter_running;
3557 static int we_are_in;
3558 static int num_prompts, echo;
3559 static char username[100];
3560 static char pwprompt[200];
3561 static char password[100];
3566 * Request userauth protocol, and await a response to it.
3568 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3569 ssh2_pkt_addstring("ssh-userauth");
3571 crWaitUntilV(ispkt);
3572 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3573 bombout(("Server refused user authentication protocol"));
3578 * We repeat this whole loop, including the username prompt,
3579 * until we manage a successful authentication. If the user
3580 * types the wrong _password_, they are sent back to the
3581 * beginning to try another username. (If they specify a
3582 * username in the config, they are never asked, even if they
3583 * do give a wrong password.)
3585 * I think this best serves the needs of
3587 * - the people who have no configuration, no keys, and just
3588 * want to try repeated (username,password) pairs until they
3589 * type both correctly
3591 * - people who have keys and configuration but occasionally
3592 * need to fall back to passwords
3594 * - people with a key held in Pageant, who might not have
3595 * logged in to a particular machine before; so they want to
3596 * type a username, and then _either_ their key will be
3597 * accepted, _or_ they will type a password. If they mistype
3598 * the username they will want to be able to get back and
3609 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3611 if (!ssh_get_line("login as: ",
3612 username, sizeof(username), FALSE)) {
3614 * get_line failed to get a username.
3617 logevent("No username provided. Abandoning session.");
3618 ssh_state = SSH_STATE_CLOSED;
3622 c_write_str("login as: ");
3625 crWaitUntilV(!ispkt);
3627 switch (c = *in++) {
3636 c_write_str("\b \b");
3643 c_write_str("\b \b");
3653 if (((c >= ' ' && c <= '~') ||
3654 ((unsigned char) c >= 160))
3655 && pos < sizeof(username)-1) {
3656 username[pos++] = c;
3663 c_write_str("\r\n");
3664 username[strcspn(username, "\n\r")] = '\0';
3667 strncpy(username, cfg.username, 99);
3668 username[99] = '\0';
3669 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3670 sprintf(stuff, "Using username \"%s\".\r\n", username);
3676 * Send an authentication request using method "none": (a)
3677 * just in case it succeeds, and (b) so that we know what
3678 * authentication methods we can usefully try next.
3680 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3681 ssh2_pkt_addstring(username);
3682 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3683 ssh2_pkt_addstring("none"); /* method */
3685 type = AUTH_TYPE_NONE;
3689 tried_pubkey_config = FALSE;
3690 tried_agent = FALSE;
3691 tried_keyb_inter = FALSE;
3692 kbd_inter_running = FALSE;
3696 * Wait for the result of the last authentication request.
3699 crWaitUntilV(ispkt);
3700 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3704 * Don't show the banner if we're operating in
3705 * non-verbose non-interactive mode. (It's probably
3706 * a script, which means nobody will read the
3707 * banner _anyway_, and moreover the printing of
3708 * the banner will screw up processing on the
3709 * output of (say) plink.)
3711 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3712 ssh2_pkt_getstring(&banner, &size);
3714 c_write_untrusted(banner, size);
3716 crWaitUntilV(ispkt);
3718 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3719 logevent("Access granted");
3724 if (kbd_inter_running &&
3725 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
3727 * This is a further prompt in keyboard-interactive
3728 * authentication. Do nothing.
3730 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3731 bombout(("Strange packet received during authentication: type %d",
3739 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3740 * we can look at the string in it and know what we can
3741 * helpfully try next.
3743 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
3746 ssh2_pkt_getstring(&methods, &methlen);
3747 kbd_inter_running = FALSE;
3748 if (!ssh2_pkt_getbool()) {
3750 * We have received an unequivocal Access
3751 * Denied. This can translate to a variety of
3754 * - if we'd just tried "none" authentication,
3755 * it's not worth printing anything at all
3757 * - if we'd just tried a public key _offer_,
3758 * the message should be "Server refused our
3759 * key" (or no message at all if the key
3760 * came from Pageant)
3762 * - if we'd just tried anything else, the
3763 * message really should be "Access denied".
3765 * Additionally, if we'd just tried password
3766 * authentication, we should break out of this
3767 * whole loop so as to go back to the username
3770 if (type == AUTH_TYPE_NONE) {
3772 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3773 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3774 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3775 c_write_str("Server refused our key\r\n");
3776 logevent("Server refused public key");
3777 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
3778 /* server declined keyboard-interactive; ignore */
3780 c_write_str("Access denied\r\n");
3781 logevent("Access denied");
3782 if (type == AUTH_TYPE_PASSWORD) {
3788 c_write_str("Further authentication required\r\n");
3789 logevent("Further authentication required");
3793 in_commasep_string("publickey", methods, methlen);
3795 in_commasep_string("password", methods, methlen);
3797 in_commasep_string("password", methods, methlen);
3799 in_commasep_string("keyboard-interactive", methods, methlen);
3804 if (!method && can_keyb_inter && !tried_keyb_inter) {
3805 method = AUTH_KEYBOARD_INTERACTIVE;
3806 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
3807 tried_keyb_inter = TRUE;
3809 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3810 ssh2_pkt_addstring(username);
3811 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3812 ssh2_pkt_addstring("keyboard-interactive"); /* method */
3813 ssh2_pkt_addstring(""); /* lang */
3814 ssh2_pkt_addstring("");
3817 crWaitUntilV(ispkt);
3818 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
3819 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
3821 logevent("Keyboard-interactive authentication refused");
3822 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
3826 kbd_inter_running = TRUE;
3829 if (kbd_inter_running) {
3830 method = AUTH_KEYBOARD_INTERACTIVE;
3831 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
3832 tried_keyb_inter = TRUE;
3834 /* We've got packet with that "interactive" info
3835 dump banners, and set its prompt as ours */
3837 char *name, *inst, *lang, *prompt;
3838 int name_len, inst_len, lang_len, prompt_len;
3839 ssh2_pkt_getstring(&name, &name_len);
3840 ssh2_pkt_getstring(&inst, &inst_len);
3841 ssh2_pkt_getstring(&lang, &lang_len);
3843 c_write_untrusted(name, name_len);
3845 c_write_untrusted(inst, inst_len);
3846 num_prompts = ssh2_pkt_getuint32();
3848 ssh2_pkt_getstring(&prompt, &prompt_len);
3849 strncpy(pwprompt, prompt, sizeof(pwprompt));
3852 echo = ssh2_pkt_getbool();
3856 if (!method && can_pubkey && agent_exists() && !tried_agent) {
3858 * Attempt public-key authentication using Pageant.
3860 static unsigned char request[5], *response, *p;
3861 static int responselen;
3862 static int i, nkeys;
3863 static int authed = FALSE;
3868 logevent("Pageant is running. Requesting keys.");
3870 /* Request the keys held by the agent. */
3871 PUT_32BIT(request, 1);
3872 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3873 agent_query(request, 5, &r, &responselen);
3874 response = (unsigned char *) r;
3875 if (response && responselen >= 5 &&
3876 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3878 nkeys = GET_32BIT(p);
3882 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3885 for (i = 0; i < nkeys; i++) {
3886 static char *pkblob, *alg, *commentp;
3887 static int pklen, alglen, commentlen;
3888 static int siglen, retlen, len;
3889 static char *q, *agentreq, *ret;
3894 sprintf(buf, "Trying Pageant key #%d", i);
3897 pklen = GET_32BIT(p);
3901 alglen = GET_32BIT(pkblob);
3903 commentlen = GET_32BIT(p);
3907 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3908 ssh2_pkt_addstring(username);
3909 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3910 ssh2_pkt_addstring("publickey"); /* method */
3911 ssh2_pkt_addbool(FALSE); /* no signature included */
3912 ssh2_pkt_addstring_start();
3913 ssh2_pkt_addstring_data(alg, alglen);
3914 ssh2_pkt_addstring_start();
3915 ssh2_pkt_addstring_data(pkblob, pklen);
3918 crWaitUntilV(ispkt);
3919 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3920 logevent("Key refused");
3924 if (flags & FLAG_VERBOSE) {
3926 ("Authenticating with public key \"");
3927 c_write(commentp, commentlen);
3928 c_write_str("\" from agent\r\n");
3932 * Server is willing to accept the key.
3933 * Construct a SIGN_REQUEST.
3935 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3936 ssh2_pkt_addstring(username);
3937 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3938 ssh2_pkt_addstring("publickey"); /* method */
3939 ssh2_pkt_addbool(TRUE);
3940 ssh2_pkt_addstring_start();
3941 ssh2_pkt_addstring_data(alg, alglen);
3942 ssh2_pkt_addstring_start();
3943 ssh2_pkt_addstring_data(pkblob, pklen);
3945 siglen = pktout.length - 5 + 4 + 20;
3946 len = 1; /* message type */
3947 len += 4 + pklen; /* key blob */
3948 len += 4 + siglen; /* data to sign */
3949 len += 4; /* flags */
3950 agentreq = smalloc(4 + len);
3951 PUT_32BIT(agentreq, len);
3953 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3954 PUT_32BIT(q, pklen);
3956 memcpy(q, pkblob, pklen);
3958 PUT_32BIT(q, siglen);
3960 /* Now the data to be signed... */
3963 memcpy(q, ssh2_session_id, 20);
3965 memcpy(q, pktout.data + 5, pktout.length - 5);
3966 q += pktout.length - 5;
3967 /* And finally the (zero) flags word. */
3969 agent_query(agentreq, len + 4, &vret, &retlen);
3973 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3974 logevent("Sending Pageant's response");
3975 ssh2_pkt_addstring_start();
3976 ssh2_pkt_addstring_data(ret + 9,
3984 ("Pageant failed to answer challenge");
3994 if (!method && can_pubkey && *cfg.keyfile
3995 && !tried_pubkey_config) {
3996 unsigned char *pub_blob;
3997 char *algorithm, *comment;
4000 tried_pubkey_config = TRUE;
4003 * Try the public key supplied in the configuration.
4005 * First, offer the public blob to see if the server is
4006 * willing to accept it.
4008 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4011 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4012 ssh2_pkt_addstring(username);
4013 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4014 ssh2_pkt_addstring("publickey"); /* method */
4015 ssh2_pkt_addbool(FALSE); /* no signature included */
4016 ssh2_pkt_addstring(algorithm);
4017 ssh2_pkt_addstring_start();
4018 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4020 logevent("Offered public key"); /* FIXME */
4022 crWaitUntilV(ispkt);
4023 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4025 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4026 continue; /* key refused; give up on it */
4029 logevent("Offer of public key accepted");
4031 * Actually attempt a serious authentication using
4034 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4036 "Passphrase for key \"%.100s\": ",
4042 c_write_str("Authenticating with public key \"");
4043 c_write_str(comment);
4044 c_write_str("\"\r\n");
4045 method = AUTH_PUBLICKEY_FILE;
4049 if (!method && can_passwd) {
4050 method = AUTH_PASSWORD;
4051 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4058 if (!ssh_get_line(pwprompt, password,
4059 sizeof(password), TRUE)) {
4061 * get_line failed to get a password (for
4062 * example because one was supplied on the
4063 * command line which has already failed to
4066 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4067 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4069 ("No more passwords available to try");
4070 ssh2_pkt_addstring("en"); /* language tag */
4072 connection_fatal("Unable to authenticate");
4073 ssh_state = SSH_STATE_CLOSED;
4080 c_write_untrusted(pwprompt, strlen(pwprompt));
4085 crWaitUntilV(!ispkt);
4087 switch (c = *in++) {
4108 if (pos < sizeof(password)-1)
4109 password[pos++] = c;
4113 c_write_str("\r\n");
4117 if (method == AUTH_PUBLICKEY_FILE) {
4119 * We have our passphrase. Now try the actual authentication.
4121 struct ssh2_userkey *key;
4123 key = ssh2_load_userkey(cfg.keyfile, password);
4124 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4125 if (key == SSH2_WRONG_PASSPHRASE) {
4126 c_write_str("Wrong passphrase\r\n");
4127 tried_pubkey_config = FALSE;
4129 c_write_str("Unable to load private key\r\n");
4130 tried_pubkey_config = TRUE;
4132 /* Send a spurious AUTH_NONE to return to the top. */
4133 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4134 ssh2_pkt_addstring(username);
4135 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4136 ssh2_pkt_addstring("none"); /* method */
4138 type = AUTH_TYPE_NONE;
4140 unsigned char *blob, *sigdata;
4141 int blob_len, sigdata_len;
4144 * We have loaded the private key and the server
4145 * has announced that it's willing to accept it.
4146 * Hallelujah. Generate a signature and send it.
4148 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4149 ssh2_pkt_addstring(username);
4150 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4151 ssh2_pkt_addstring("publickey"); /* method */
4152 ssh2_pkt_addbool(TRUE);
4153 ssh2_pkt_addstring(key->alg->name);
4154 blob = key->alg->public_blob(key->data, &blob_len);
4155 ssh2_pkt_addstring_start();
4156 ssh2_pkt_addstring_data(blob, blob_len);
4160 * The data to be signed is:
4164 * followed by everything so far placed in the
4167 sigdata_len = pktout.length - 5 + 4 + 20;
4168 sigdata = smalloc(sigdata_len);
4169 PUT_32BIT(sigdata, 20);
4170 memcpy(sigdata + 4, ssh2_session_id, 20);
4171 memcpy(sigdata + 24, pktout.data + 5,
4174 key->alg->sign(key->data, sigdata, sigdata_len,
4176 ssh2_pkt_addstring_start();
4177 ssh2_pkt_addstring_data(blob, blob_len);
4182 type = AUTH_TYPE_PUBLICKEY;
4184 } else if (method == AUTH_PASSWORD) {
4186 * We send the password packet lumped tightly together with
4187 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4188 * string long enough to make the total length of the two
4189 * packets constant. This should ensure that a passive
4190 * listener doing traffic analyis can't work out the length
4193 * For this to work, we need an assumption about the
4194 * maximum length of the password packet. I think 256 is
4195 * pretty conservative. Anyone using a password longer than
4196 * that probably doesn't have much to worry about from
4197 * people who find out how long their password is!
4199 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4200 ssh2_pkt_addstring(username);
4201 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4202 ssh2_pkt_addstring("password");
4203 ssh2_pkt_addbool(FALSE);
4204 ssh2_pkt_addstring(password);
4207 * We'll include a string that's an exact multiple of the
4208 * cipher block size. If the cipher is NULL for some
4209 * reason, we don't do this trick at all because we gain
4215 stringlen = (256 - deferred_len);
4216 stringlen += cscipher->blksize - 1;
4217 stringlen -= (stringlen % cscipher->blksize);
4220 * Temporarily disable actual compression,
4221 * so we can guarantee to get this string
4222 * exactly the length we want it. The
4223 * compression-disabling routine should
4224 * return an integer indicating how many
4225 * bytes we should adjust our string length
4228 stringlen -= cscomp->disable_compression();
4230 ssh2_pkt_init(SSH2_MSG_IGNORE);
4231 ssh2_pkt_addstring_start();
4232 for (i = 0; i < stringlen; i++) {
4233 char c = (char) random_byte();
4234 ssh2_pkt_addstring_data(&c, 1);
4238 ssh_pkt_defersend();
4239 logevent("Sent password");
4240 type = AUTH_TYPE_PASSWORD;
4241 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4242 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4243 ssh2_pkt_adduint32(num_prompts);
4244 ssh2_pkt_addstring(password);
4245 memset(password, 0, sizeof(password));
4247 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4250 ("No supported authentication methods left to try!\r\n");
4252 ("No supported authentications offered. Disconnecting");
4253 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4254 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4256 ("No supported authentication methods available");
4257 ssh2_pkt_addstring("en"); /* language tag */
4259 ssh_state = SSH_STATE_CLOSED;
4263 } while (!we_are_in);
4266 * Now we're authenticated for the connection protocol. The
4267 * connection protocol will automatically have started at this
4268 * point; there's no need to send SERVICE_REQUEST.
4272 * So now create a channel with a session in it.
4274 ssh_channels = newtree234(ssh_channelcmp);
4275 mainchan = smalloc(sizeof(struct ssh_channel));
4276 mainchan->localid = alloc_channel_id();
4277 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4278 ssh2_pkt_addstring("session");
4279 ssh2_pkt_adduint32(mainchan->localid);
4280 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4281 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4282 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4284 crWaitUntilV(ispkt);
4285 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4286 bombout(("Server refused to open a session"));
4288 /* FIXME: error data comes back in FAILURE packet */
4290 if (ssh2_pkt_getuint32() != mainchan->localid) {
4291 bombout(("Server's channel confirmation cited wrong channel"));
4294 mainchan->remoteid = ssh2_pkt_getuint32();
4295 mainchan->type = CHAN_MAINSESSION;
4296 mainchan->closes = 0;
4297 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4298 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4299 bufchain_init(&mainchan->v.v2.outbuffer);
4300 add234(ssh_channels, mainchan);
4301 logevent("Opened channel for session");
4304 * Potentially enable X11 forwarding.
4306 if (cfg.x11_forward) {
4307 char proto[20], data[64];
4308 logevent("Requesting X11 forwarding");
4309 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4310 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4311 ssh2_pkt_adduint32(mainchan->remoteid);
4312 ssh2_pkt_addstring("x11-req");
4313 ssh2_pkt_addbool(1); /* want reply */
4314 ssh2_pkt_addbool(0); /* many connections */
4315 ssh2_pkt_addstring(proto);
4316 ssh2_pkt_addstring(data);
4317 ssh2_pkt_adduint32(0); /* screen number */
4321 crWaitUntilV(ispkt);
4322 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4323 unsigned i = ssh2_pkt_getuint32();
4324 struct ssh_channel *c;
4325 c = find234(ssh_channels, &i, ssh_channelfind);
4327 continue; /* nonexistent channel */
4328 c->v.v2.remwindow += ssh2_pkt_getuint32();
4330 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4332 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4333 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4334 bombout(("Server got confused by X11 forwarding request"));
4337 logevent("X11 forwarding refused");
4339 logevent("X11 forwarding enabled");
4340 ssh_X11_fwd_enabled = TRUE;
4345 * Enable port forwardings.
4348 static char *e; /* preserve across crReturn */
4352 char sports[256], dports[256], host[256];
4355 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4356 /* Add port forwardings. */
4361 while (*e && *e != '\t')
4367 while (*e && *e != ':')
4377 dport = atoi(dports);
4378 sport = atoi(sports);
4379 if (sport && dport) {
4381 pfd_addforward(host, dport, sport);
4382 sprintf(buf, "Local port %d forwarding to %s:%d",
4383 sport, host, dport);
4386 struct ssh_rportfwd *pf;
4387 pf = smalloc(sizeof(*pf));
4388 strcpy(pf->dhost, host);
4391 if (add234(ssh_rportfwds, pf) != pf) {
4393 "Duplicate remote port forwarding to %s:%d",
4398 sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
4399 sport, host, dport);
4401 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4402 ssh2_pkt_addstring("tcpip-forward");
4403 ssh2_pkt_addbool(1);/* want reply */
4404 ssh2_pkt_addstring("127.0.0.1");
4405 ssh2_pkt_adduint32(sport);
4409 crWaitUntilV(ispkt);
4410 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4411 unsigned i = ssh2_pkt_getuint32();
4412 struct ssh_channel *c;
4413 c = find234(ssh_channels, &i, ssh_channelfind);
4415 continue;/* nonexistent channel */
4416 c->v.v2.remwindow += ssh2_pkt_getuint32();
4418 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4420 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4421 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
4422 bombout(("Server got confused by port forwarding request"));
4425 logevent("Server refused this port forwarding");
4427 logevent("Remote port forwarding enabled");
4436 * Potentially enable agent forwarding.
4438 if (cfg.agentfwd && agent_exists()) {
4439 logevent("Requesting OpenSSH-style agent forwarding");
4440 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4441 ssh2_pkt_adduint32(mainchan->remoteid);
4442 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4443 ssh2_pkt_addbool(1); /* want reply */
4447 crWaitUntilV(ispkt);
4448 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4449 unsigned i = ssh2_pkt_getuint32();
4450 struct ssh_channel *c;
4451 c = find234(ssh_channels, &i, ssh_channelfind);
4453 continue; /* nonexistent channel */
4454 c->v.v2.remwindow += ssh2_pkt_getuint32();
4456 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4458 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4459 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4461 ("Server got confused by agent forwarding request"));
4464 logevent("Agent forwarding refused");
4466 logevent("Agent forwarding enabled");
4467 ssh_agentfwd_enabled = TRUE;
4472 * Now allocate a pty for the session.
4475 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4476 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4477 ssh2_pkt_addstring("pty-req");
4478 ssh2_pkt_addbool(1); /* want reply */
4479 ssh2_pkt_addstring(cfg.termtype);
4480 ssh2_pkt_adduint32(cols);
4481 ssh2_pkt_adduint32(rows);
4482 ssh2_pkt_adduint32(0); /* pixel width */
4483 ssh2_pkt_adduint32(0); /* pixel height */
4484 ssh2_pkt_addstring_start();
4485 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4487 ssh_state = SSH_STATE_INTERMED;
4490 crWaitUntilV(ispkt);
4491 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4492 unsigned i = ssh2_pkt_getuint32();
4493 struct ssh_channel *c;
4494 c = find234(ssh_channels, &i, ssh_channelfind);
4496 continue; /* nonexistent channel */
4497 c->v.v2.remwindow += ssh2_pkt_getuint32();
4499 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4501 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4502 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4503 bombout(("Server got confused by pty request"));
4506 c_write_str("Server refused to allocate pty\r\n");
4507 ssh_editing = ssh_echoing = 1;
4509 logevent("Allocated pty");
4512 ssh_editing = ssh_echoing = 1;
4516 * Start a shell or a remote command. We may have to attempt
4517 * this twice if the config data has provided a second choice
4524 if (ssh_fallback_cmd) {
4525 subsys = cfg.ssh_subsys2;
4526 cmd = cfg.remote_cmd_ptr2;
4528 subsys = cfg.ssh_subsys;
4529 cmd = cfg.remote_cmd_ptr;
4532 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4533 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4535 ssh2_pkt_addstring("subsystem");
4536 ssh2_pkt_addbool(1); /* want reply */
4537 ssh2_pkt_addstring(cmd);
4539 ssh2_pkt_addstring("exec");
4540 ssh2_pkt_addbool(1); /* want reply */
4541 ssh2_pkt_addstring(cmd);
4543 ssh2_pkt_addstring("shell");
4544 ssh2_pkt_addbool(1); /* want reply */
4548 crWaitUntilV(ispkt);
4549 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4550 unsigned i = ssh2_pkt_getuint32();
4551 struct ssh_channel *c;
4552 c = find234(ssh_channels, &i, ssh_channelfind);
4554 continue; /* nonexistent channel */
4555 c->v.v2.remwindow += ssh2_pkt_getuint32();
4557 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4558 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4559 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4560 bombout(("Server got confused by shell/command request"));
4564 * We failed to start the command. If this is the
4565 * fallback command, we really are finished; if it's
4566 * not, and if the fallback command exists, try falling
4567 * back to it before complaining.
4569 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
4570 logevent("Primary command failed; attempting fallback");
4571 ssh_fallback_cmd = TRUE;
4574 bombout(("Server refused to start a shell/command"));
4577 logevent("Started a shell/command");
4582 ssh_state = SSH_STATE_SESSION;
4586 ssh_special(TS_EOF);
4591 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
4594 static int try_send;
4598 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
4599 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4602 unsigned i = ssh2_pkt_getuint32();
4603 struct ssh_channel *c;
4604 c = find234(ssh_channels, &i, ssh_channelfind);
4606 continue; /* nonexistent channel */
4607 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4608 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4609 continue; /* extended but not stderr */
4610 ssh2_pkt_getstring(&data, &length);
4613 c->v.v2.locwindow -= length;
4615 case CHAN_MAINSESSION:
4617 from_backend(pktin.type ==
4618 SSH2_MSG_CHANNEL_EXTENDED_DATA,
4622 bufsize = x11_send(c->u.x11.s, data, length);
4625 bufsize = pfd_send(c->u.pfd.s, data, length);
4628 while (length > 0) {
4629 if (c->u.a.lensofar < 4) {
4630 int l = min(4 - c->u.a.lensofar, length);
4631 memcpy(c->u.a.msglen + c->u.a.lensofar,
4635 c->u.a.lensofar += l;
4637 if (c->u.a.lensofar == 4) {
4639 4 + GET_32BIT(c->u.a.msglen);
4640 c->u.a.message = smalloc(c->u.a.totallen);
4641 memcpy(c->u.a.message, c->u.a.msglen, 4);
4643 if (c->u.a.lensofar >= 4 && length > 0) {
4645 min(c->u.a.totallen - c->u.a.lensofar,
4647 memcpy(c->u.a.message + c->u.a.lensofar,
4651 c->u.a.lensofar += l;
4653 if (c->u.a.lensofar == c->u.a.totallen) {
4654 void *reply, *sentreply;
4656 agent_query(c->u.a.message,
4657 c->u.a.totallen, &reply,
4662 /* Fake SSH_AGENT_FAILURE. */
4663 sentreply = "\0\0\0\1\5";
4666 ssh2_add_channel_data(c, sentreply,
4671 sfree(c->u.a.message);
4672 c->u.a.lensofar = 0;
4679 * If we are not buffering too much data,
4680 * enlarge the window again at the remote side.
4682 if (bufsize < OUR_V2_WINSIZE)
4683 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
4685 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4686 ssh_state = SSH_STATE_CLOSED;
4687 logevent("Received disconnect message");
4689 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
4690 continue; /* exit status et al; ignore (FIXME?) */
4691 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4692 unsigned i = ssh2_pkt_getuint32();
4693 struct ssh_channel *c;
4695 c = find234(ssh_channels, &i, ssh_channelfind);
4697 continue; /* nonexistent channel */
4699 if (c->type == CHAN_X11) {
4701 * Remote EOF on an X11 channel means we should
4702 * wrap up and close the channel ourselves.
4704 x11_close(c->u.x11.s);
4706 } else if (c->type == CHAN_AGENT) {
4708 } else if (c->type == CHAN_SOCKDATA) {
4709 pfd_close(c->u.pfd.s);
4712 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4713 unsigned i = ssh2_pkt_getuint32();
4714 struct ssh_channel *c;
4716 c = find234(ssh_channels, &i, ssh_channelfind);
4718 continue; /* nonexistent channel */
4719 if (c->closes == 0) {
4720 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4721 ssh2_pkt_adduint32(c->remoteid);
4724 /* Do pre-close processing on the channel. */
4726 case CHAN_MAINSESSION:
4727 break; /* nothing to see here, move along */
4735 del234(ssh_channels, c);
4736 bufchain_clear(&c->v.v2.outbuffer);
4740 * See if that was the last channel left open.
4742 if (count234(ssh_channels) == 0) {
4743 logevent("All channels closed. Disconnecting");
4744 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4745 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4746 ssh2_pkt_addstring("All open channels closed");
4747 ssh2_pkt_addstring("en"); /* language tag */
4749 ssh_state = SSH_STATE_CLOSED;
4752 continue; /* remote sends close; ignore (FIXME) */
4753 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4754 unsigned i = ssh2_pkt_getuint32();
4755 struct ssh_channel *c;
4756 c = find234(ssh_channels, &i, ssh_channelfind);
4758 continue; /* nonexistent channel */
4759 c->v.v2.remwindow += ssh2_pkt_getuint32();
4761 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4762 unsigned i = ssh2_pkt_getuint32();
4763 struct ssh_channel *c;
4764 c = find234(ssh_channels, &i, ssh_channelfind);
4766 continue; /* nonexistent channel */
4767 if (c->type != CHAN_SOCKDATA_DORMANT)
4768 continue; /* dunno why they're confirming this */
4769 c->remoteid = ssh2_pkt_getuint32();
4770 c->type = CHAN_SOCKDATA;
4772 c->v.v2.remwindow = ssh2_pkt_getuint32();
4773 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4774 bufchain_init(&c->v.v2.outbuffer);
4775 pfd_confirm(c->u.pfd.s);
4776 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
4780 struct ssh_channel *c;
4781 unsigned remid, winsize, pktsize;
4782 ssh2_pkt_getstring(&type, &typelen);
4783 c = smalloc(sizeof(struct ssh_channel));
4785 remid = ssh2_pkt_getuint32();
4786 winsize = ssh2_pkt_getuint32();
4787 pktsize = ssh2_pkt_getuint32();
4789 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4790 if (!ssh_X11_fwd_enabled)
4791 error = "X11 forwarding is not enabled";
4792 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4794 error = "Unable to open an X11 connection";
4798 } else if (typelen == 15 &&
4799 !memcmp(type, "forwarded-tcpip", 15)) {
4800 struct ssh_rportfwd pf, *realpf;
4803 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
4804 pf.sport = ssh2_pkt_getuint32();
4805 realpf = find234(ssh_rportfwds, &pf, NULL);
4806 if (realpf == NULL) {
4807 error = "Remote port is not recognised";
4809 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
4812 sprintf(buf, "Received remote port open request for %s:%d",
4813 realpf->dhost, realpf->dport);
4816 sprintf(buf, "Port open failed: %s", e);
4818 error = "Port open failed";
4820 logevent("Forwarded port opened successfully");
4821 c->type = CHAN_SOCKDATA;
4824 } else if (typelen == 22 &&
4825 !memcmp(type, "auth-agent@openssh.com", 3)) {
4826 if (!ssh_agentfwd_enabled)
4827 error = "Agent forwarding is not enabled";
4829 c->type = CHAN_AGENT; /* identify channel type */
4830 c->u.a.lensofar = 0;
4833 error = "Unsupported channel type requested";
4836 c->remoteid = remid;
4838 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4839 ssh2_pkt_adduint32(c->remoteid);
4840 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4841 ssh2_pkt_addstring(error);
4842 ssh2_pkt_addstring("en"); /* language tag */
4846 c->localid = alloc_channel_id();
4848 c->v.v2.locwindow = OUR_V2_WINSIZE;
4849 c->v.v2.remwindow = winsize;
4850 c->v.v2.remmaxpkt = pktsize;
4851 bufchain_init(&c->v.v2.outbuffer);
4852 add234(ssh_channels, c);
4853 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4854 ssh2_pkt_adduint32(c->remoteid);
4855 ssh2_pkt_adduint32(c->localid);
4856 ssh2_pkt_adduint32(c->v.v2.locwindow);
4857 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4861 bombout(("Strange packet received: type %d", pktin.type));
4866 * We have spare data. Add it to the channel buffer.
4868 ssh2_add_channel_data(mainchan, in, inlen);
4873 struct ssh_channel *c;
4875 * Try to send data on all channels if we can.
4877 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
4878 int bufsize = ssh2_try_send(c);
4881 case CHAN_MAINSESSION:
4882 /* stdin need not receive an unthrottle
4883 * notification since it will be polled */
4886 x11_unthrottle(c->u.x11.s);
4889 /* agent sockets are request/response and need no
4890 * buffer management */
4893 pfd_unthrottle(c->u.pfd.s);
4905 * Handle the top-level SSH2 protocol.
4907 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4909 if (do_ssh2_transport(in, inlen, ispkt) == 0)
4911 do_ssh2_authconn(in, inlen, ispkt);
4915 * Called to set up the connection.
4917 * Returns an error message, or NULL on success.
4919 static char *ssh_init(char *host, int port, char **realhost)
4924 if (crypto_startup() == 0)
4925 return "Microsoft high encryption pack not installed!";
4931 ssh1_throttle_count = 0;
4932 ssh_overall_bufsize = 0;
4933 ssh_fallback_cmd = 0;
4935 p = connect_to_host(host, port, realhost);
4943 * Called to send data down the Telnet connection.
4945 static int ssh_send(char *buf, int len)
4947 if (s == NULL || ssh_protocol == NULL)
4950 ssh_protocol(buf, len, 0);
4952 return ssh_sendbuffer();
4956 * Called to query the current amount of buffered stdin data.
4958 static int ssh_sendbuffer(void)
4962 if (s == NULL || ssh_protocol == NULL)
4966 * If the SSH socket itself has backed up, add the total backup
4967 * size on that to any individual buffer on the stdin channel.
4970 if (ssh_throttled_all)
4971 override_value = ssh_overall_bufsize;
4973 if (ssh_version == 1) {
4974 return override_value;
4975 } else if (ssh_version == 2) {
4976 if (!mainchan || mainchan->closes > 0)
4977 return override_value;
4979 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
4986 * Called to set the size of the window from SSH's POV.
4988 static void ssh_size(void)
4990 switch (ssh_state) {
4991 case SSH_STATE_BEFORE_SIZE:
4992 case SSH_STATE_PREPACKET:
4993 case SSH_STATE_CLOSED:
4994 break; /* do nothing */
4995 case SSH_STATE_INTERMED:
4996 size_needed = TRUE; /* buffer for later */
4998 case SSH_STATE_SESSION:
5000 if (ssh_version == 1) {
5001 send_packet(SSH1_CMSG_WINDOW_SIZE,
5002 PKT_INT, rows, PKT_INT, cols,
5003 PKT_INT, 0, PKT_INT, 0, PKT_END);
5005 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5006 ssh2_pkt_adduint32(mainchan->remoteid);
5007 ssh2_pkt_addstring("window-change");
5008 ssh2_pkt_addbool(0);
5009 ssh2_pkt_adduint32(cols);
5010 ssh2_pkt_adduint32(rows);
5011 ssh2_pkt_adduint32(0);
5012 ssh2_pkt_adduint32(0);
5021 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5022 * can send an EOF and collect resulting output (e.g. `plink
5025 static void ssh_special(Telnet_Special code)
5027 if (code == TS_EOF) {
5028 if (ssh_state != SSH_STATE_SESSION) {
5030 * Buffer the EOF in case we are pre-SESSION, so we can
5031 * send it as soon as we reach SESSION.
5037 if (ssh_version == 1) {
5038 send_packet(SSH1_CMSG_EOF, PKT_END);
5040 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5041 ssh2_pkt_adduint32(mainchan->remoteid);
5044 logevent("Sent EOF message");
5045 } else if (code == TS_PING) {
5046 if (ssh_state == SSH_STATE_CLOSED
5047 || ssh_state == SSH_STATE_PREPACKET) return;
5048 if (ssh_version == 1) {
5049 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5051 ssh2_pkt_init(SSH2_MSG_IGNORE);
5052 ssh2_pkt_addstring_start();
5060 void *new_sock_channel(Socket s)
5062 struct ssh_channel *c;
5063 c = smalloc(sizeof(struct ssh_channel));
5066 c->remoteid = -1; /* to be set when open confirmed */
5067 c->localid = alloc_channel_id();
5069 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5071 add234(ssh_channels, c);
5077 * This is called when stdout/stderr (the entity to which
5078 * from_backend sends data) manages to clear some backlog.
5080 void ssh_unthrottle(int bufsize)
5082 if (ssh_version == 1) {
5083 if (bufsize < SSH1_BUFFER_LIMIT) {
5084 ssh1_stdout_throttling = 0;
5088 if (mainchan && mainchan->closes == 0)
5089 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5093 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5095 struct ssh_channel *c = (struct ssh_channel *)channel;
5098 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5101 if (ssh_version == 1) {
5102 send_packet(SSH1_MSG_PORT_OPEN,
5103 PKT_INT, c->localid,
5106 //PKT_STR, <org:orgport>,
5109 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5110 ssh2_pkt_addstring("direct-tcpip");
5111 ssh2_pkt_adduint32(c->localid);
5112 c->v.v2.locwindow = OUR_V2_WINSIZE;
5113 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5114 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5115 ssh2_pkt_addstring(hostname);
5116 ssh2_pkt_adduint32(port);
5118 * We make up values for the originator data; partly it's
5119 * too much hassle to keep track, and partly I'm not
5120 * convinced the server should be told details like that
5121 * about my local network configuration.
5123 ssh2_pkt_addstring("client-side-connection");
5124 ssh2_pkt_adduint32(0);
5130 static Socket ssh_socket(void)
5135 static int ssh_sendok(void)
5140 static int ssh_ldisc(int option)
5142 if (option == LD_ECHO)
5144 if (option == LD_EDIT)
5149 Backend ssh_backend = {