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Jan Holmen Holsten's patch for drag-selects to scroll the scrollback.
[u/mdw/putty] / ssh.c
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8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
765c4200 18/* uncomment this for packet level debugging */
19/* #define DUMP_PACKETS */
20
fb09bf1c 21#define logevent(s) { logevent(s); \
67779be7 22 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
b4453f49 23 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
fb09bf1c 24
3cd52910 25#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
4a8fc3c4 26 (s ? sk_close(s), s = NULL : 0), \
3cd52910 27 connection_fatal msg )
8d5de777 28
32874aea 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 */
70
71#define SSH1_AUTH_TIS 5 /* 0x5 */
72#define SSH1_AUTH_CCARD 16 /* 0x10 */
73
74#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 75/* Mask for protoflags we will echo back to server if seen */
32874aea 76#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
77
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 */
761187b6 98#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
99#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 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 */
114
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 */
38c4a8da 130
131static const char *const ssh2_disconnect_reasons[] = {
132 NULL,
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",
148};
9005f3ba 149
32874aea 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 */
d211621f 154
32874aea 155#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 156
7d503c31 157/*
158 * Various remote-bug flags.
159 */
160#define BUG_CHOKES_ON_SSH1_IGNORE 1
161#define BUG_SSH2_HMAC 2
162
fb09bf1c 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]))
168
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); }
174
7cca0d81 175enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 176
374330e2 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) \
184 do {\
185 crLine=__LINE__; return (z); case __LINE__:;\
186 } while (0)
187#define crReturnV \
188 do {\
189 crLine=__LINE__; return; case __LINE__:;\
190 } while (0)
191#define crStop(z) do{ crLine = 0; return (z); }while(0)
192#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 193#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 194#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 195
32874aea 196extern char *x11_init(Socket *, char *, void *);
197extern void x11_close(Socket);
5471d09a 198extern int x11_send(Socket, char *, int);
9c964e85 199extern void x11_invent_auth(char *, int, char *, int);
5471d09a 200extern void x11_unthrottle(Socket s);
201extern void x11_override_throttle(Socket s, int enable);
9c964e85 202
d74d141c 203extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
204extern char *pfd_addforward(char *desthost, int destport, int port);
205extern void pfd_close(Socket s);
5471d09a 206extern int pfd_send(Socket s, char *data, int len);
d74d141c 207extern void pfd_confirm(Socket s);
5471d09a 208extern void pfd_unthrottle(Socket s);
209extern void pfd_override_throttle(Socket s, int enable);
210
211/*
212 * Buffer management constants. There are several of these for
213 * various different purposes:
214 *
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
219 * happen very often.
220 *
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.
227 *
228 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
229 * channels.
230 */
231
232#define SSH1_BUFFER_LIMIT 32768
233#define SSH_MAX_BACKLOG 32768
234#define OUR_V2_WINSIZE 16384
d74d141c 235
5e8358ad 236/*
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.)
5e8358ad 241 */
0a3f1d48 242const static struct ssh2_ciphers *ciphers[] = {
243 &ssh2_aes,
244 &ssh2_blowfish,
245 &ssh2_3des,
8479e33c 246};
e5574168 247
a92dd380 248const static struct ssh_kex *kex_algs[] = {
a92dd380 249 &ssh_diffiehellman_gex,
32874aea 250 &ssh_diffiehellman
251};
e5574168 252
85cc02bb 253const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 254
32874aea 255static void nullmac_key(unsigned char *key)
256{
257}
258static void nullmac_generate(unsigned char *blk, int len,
259 unsigned long seq)
260{
261}
262static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
263{
264 return 1;
265}
57476f6b 266const static struct ssh_mac ssh_mac_none = {
d39f364a 267 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 268};
8b2715b2 269const static struct ssh_mac *macs[] = {
32874aea 270 &ssh_sha1, &ssh_md5, &ssh_mac_none
271};
8b2715b2 272const static struct ssh_mac *buggymacs[] = {
32874aea 273 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
274};
e5574168 275
32874aea 276static void ssh_comp_none_init(void)
277{
278}
4ba9b64b 279static int ssh_comp_none_block(unsigned char *block, int len,
32874aea 280 unsigned char **outblock, int *outlen)
281{
282 return 0;
283}
284static int ssh_comp_none_disable(void)
285{
4ba9b64b 286 return 0;
287}
57476f6b 288const static struct ssh_compress ssh_comp_none = {
4ba9b64b 289 "none",
290 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 291 ssh_comp_none_init, ssh_comp_none_block,
292 ssh_comp_none_disable
e5574168 293};
4ba9b64b 294extern const struct ssh_compress ssh_zlib;
295const static struct ssh_compress *compressions[] = {
32874aea 296 &ssh_zlib, &ssh_comp_none
297};
374330e2 298
32874aea 299enum { /* channel types */
783415f8 300 CHAN_MAINSESSION,
301 CHAN_X11,
302 CHAN_AGENT,
bc240b21 303 CHAN_SOCKDATA,
304 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 305};
306
dacbd0e8 307/*
308 * 2-3-4 tree storing channels.
309 */
310struct ssh_channel {
d211621f 311 unsigned remoteid, localid;
dacbd0e8 312 int type;
313 int closes;
5471d09a 314 union {
315 struct ssh1_data_channel {
316 int throttling;
317 } v1;
318 struct ssh2_data_channel {
319 bufchain outbuffer;
320 unsigned remwindow, remmaxpkt;
321 unsigned locwindow;
322 } v2;
323 } v;
dacbd0e8 324 union {
32874aea 325 struct ssh_agent_channel {
326 unsigned char *message;
327 unsigned char msglen[4];
328 int lensofar, totallen;
329 } a;
330 struct ssh_x11_channel {
331 Socket s;
332 } x11;
d74d141c 333 struct ssh_pfd_channel {
334 Socket s;
335 } pfd;
dacbd0e8 336 } u;
337};
57476f6b 338
d74d141c 339/*
bc240b21 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.
343 *
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.
355 *
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.
362 *
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.
d74d141c 367 */
368struct ssh_rportfwd {
bc240b21 369 unsigned sport, dport;
370 char dhost[256];
d74d141c 371};
372
57476f6b 373struct Packet {
374 long length;
375 int type;
376 unsigned char *data;
377 unsigned char *body;
378 long savedpos;
379 long maxlen;
380};
381
0db56f73 382static SHA_State exhash, exhashbase;
57476f6b 383
8df7a775 384static Socket s = NULL;
57476f6b 385
386static unsigned char session_key[32];
4ba9b64b 387static int ssh1_compressing;
b96dc54c 388static int ssh1_remote_protoflags;
389static int ssh1_local_protoflags;
db7d555c 390static int ssh_agentfwd_enabled;
9c964e85 391static int ssh_X11_fwd_enabled;
7d503c31 392static int ssh_remote_bugs;
57476f6b 393static const struct ssh_cipher *cipher = NULL;
0a3f1d48 394static const struct ssh2_cipher *cscipher = NULL;
395static const struct ssh2_cipher *sccipher = NULL;
57476f6b 396static const struct ssh_mac *csmac = NULL;
397static const struct ssh_mac *scmac = NULL;
398static const struct ssh_compress *cscomp = NULL;
399static const struct ssh_compress *sccomp = NULL;
400static const struct ssh_kex *kex = NULL;
e055a386 401static const struct ssh_signkey *hostkey = NULL;
65a22376 402static unsigned char ssh2_session_id[20];
32874aea 403int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
404 int is_pw) = NULL;
57476f6b 405
406static char *savedhost;
407static int savedport;
408static int ssh_send_ok;
0965bee0 409static int ssh_echoing, ssh_editing;
57476f6b 410
32874aea 411static tree234 *ssh_channels; /* indexed by local id */
57476f6b 412static struct ssh_channel *mainchan; /* primary session channel */
413
d74d141c 414static tree234 *ssh_rportfwds;
415
57476f6b 416static enum {
3687d221 417 SSH_STATE_PREPACKET,
57476f6b 418 SSH_STATE_BEFORE_SIZE,
419 SSH_STATE_INTERMED,
420 SSH_STATE_SESSION,
421 SSH_STATE_CLOSED
3687d221 422} ssh_state = SSH_STATE_PREPACKET;
57476f6b 423
3687d221 424static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 425
426static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
427static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 428static unsigned char *deferred_send_data = NULL;
429static int deferred_len = 0, deferred_size = 0;
57476f6b 430
fd5e5847 431/*
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.
435 */
436int ssh_fallback_cmd = 0;
437
57476f6b 438static int ssh_version;
5471d09a 439static int ssh1_throttle_count;
440static int ssh_overall_bufsize;
441static int ssh_throttled_all;
442static int ssh1_stdout_throttling;
32874aea 443static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
57476f6b 444static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
445static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
446static void ssh_size(void);
32874aea 447static void ssh_special(Telnet_Special);
5471d09a 448static int ssh2_try_send(struct ssh_channel *c);
32874aea 449static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
450 int len);
5471d09a 451static void ssh_throttle_all(int enable, int bufsize);
452static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
32874aea 453static int (*s_rdpkt) (unsigned char **data, int *datalen);
5471d09a 454static int ssh_sendbuffer(void);
57476f6b 455
456static struct rdpkt1_state_tag {
457 long len, pad, biglen, to_read;
458 unsigned long realcrc, gotcrc;
459 unsigned char *p;
460 int i;
461 int chunk;
462} rdpkt1_state;
463
960e736a 464static struct rdpkt2_state_tag {
465 long len, pad, payload, packetlen, maclen;
466 int i;
467 int cipherblk;
468 unsigned long incoming_sequence;
469} rdpkt2_state;
470
32874aea 471static int ssh_channelcmp(void *av, void *bv)
472{
473 struct ssh_channel *a = (struct ssh_channel *) av;
474 struct ssh_channel *b = (struct ssh_channel *) bv;
475 if (a->localid < b->localid)
476 return -1;
477 if (a->localid > b->localid)
478 return +1;
dacbd0e8 479 return 0;
480}
32874aea 481static int ssh_channelfind(void *av, void *bv)
482{
483 unsigned *a = (unsigned *) av;
484 struct ssh_channel *b = (struct ssh_channel *) bv;
485 if (*a < b->localid)
486 return -1;
487 if (*a > b->localid)
488 return +1;
dacbd0e8 489 return 0;
490}
491
bc240b21 492static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 493{
494 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
495 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
496 int i;
bc240b21 497 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 498 return i < 0 ? -1 : +1;
bc240b21 499 if (a->dport > b->dport)
500 return +1;
501 if (a->dport < b->dport)
502 return -1;
503 return 0;
504}
505
506static int ssh_rportcmp_ssh2(void *av, void *bv)
507{
508 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
509 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 510
bc240b21 511 if (a->sport > b->sport)
d74d141c 512 return +1;
bc240b21 513 if (a->sport < b->sport)
514 return -1;
d74d141c 515 return 0;
516}
517
32874aea 518static int alloc_channel_id(void)
519{
260f3dec 520 const unsigned CHANNEL_NUMBER_OFFSET = 256;
521 unsigned low, high, mid;
d2371c81 522 int tsize;
523 struct ssh_channel *c;
524
525 /*
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.)
532 */
533 tsize = count234(ssh_channels);
534
32874aea 535 low = -1;
536 high = tsize;
d2371c81 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 */
542 else
543 high = mid; /* this one is past it */
544 }
545 /*
546 * Now low points to either -1, or the tree index of the
547 * largest ID in the initial sequence.
548 */
549 {
550 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
551 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
552 }
553 return low + 1 + CHANNEL_NUMBER_OFFSET;
554}
555
32874aea 556static void c_write(char *buf, int len)
557{
67779be7 558 if ((flags & FLAG_STDERR)) {
32874aea 559 int i;
560 for (i = 0; i < len; i++)
561 if (buf[i] != '\r')
562 fputc(buf[i], stderr);
fb09bf1c 563 return;
564 }
fe50e814 565 from_backend(1, buf, len);
3bdaf79d 566}
567
32874aea 568static void c_write_untrusted(char *buf, int len)
569{
a209e957 570 int i;
571 for (i = 0; i < len; i++) {
32874aea 572 if (buf[i] == '\n')
573 c_write("\r\n", 2);
574 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
575 c_write(buf + i, 1);
a209e957 576 }
577}
578
32874aea 579static void c_write_str(char *buf)
580{
1408a877 581 c_write(buf, strlen(buf));
582}
583
fb09bf1c 584/*
585 * Collect incoming data in the incoming packet buffer.
e5574168 586 * Decipher and verify the packet when it is completely read.
587 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 588 * Update the *data and *datalen variables.
589 * Return the additional nr of bytes needed, or 0 when
590 * a complete packet is available.
591 */
e5574168 592static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 593{
57476f6b 594 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 595
596 crBegin;
374330e2 597
32874aea 598 next_packet:
37508af4 599
fb09bf1c 600 pktin.type = 0;
601 pktin.length = 0;
374330e2 602
57476f6b 603 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 604 while ((*datalen) == 0)
32874aea 605 crReturn(4 - st->i);
57476f6b 606 st->len = (st->len << 8) + **data;
fb09bf1c 607 (*data)++, (*datalen)--;
608 }
374330e2 609
fb09bf1c 610#ifdef FWHACK
32874aea 611 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
612 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 613 }
614#endif
374330e2 615
57476f6b 616 st->pad = 8 - (st->len % 8);
617 st->biglen = st->len + st->pad;
618 pktin.length = st->len - 5;
fb09bf1c 619
57476f6b 620 if (pktin.maxlen < st->biglen) {
621 pktin.maxlen = st->biglen;
32874aea 622 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
623 srealloc(pktin.data, st->biglen + APIEXTRA));
fb09bf1c 624 if (!pktin.data)
625 fatalbox("Out of memory");
626 }
374330e2 627
57476f6b 628 st->to_read = st->biglen;
629 st->p = pktin.data;
630 while (st->to_read > 0) {
32874aea 631 st->chunk = st->to_read;
fb09bf1c 632 while ((*datalen) == 0)
57476f6b 633 crReturn(st->to_read);
634 if (st->chunk > (*datalen))
635 st->chunk = (*datalen);
636 memcpy(st->p, *data, st->chunk);
637 *data += st->chunk;
638 *datalen -= st->chunk;
639 st->p += st->chunk;
640 st->to_read -= st->chunk;
fb09bf1c 641 }
374330e2 642
fb09bf1c 643 if (cipher)
57476f6b 644 cipher->decrypt(pktin.data, st->biglen);
765c4200 645#ifdef DUMP_PACKETS
646 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
647 dmemdump(pktin.data, st->biglen);
698a5108 648#endif
374330e2 649
32874aea 650 st->realcrc = crc32(pktin.data, st->biglen - 4);
651 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
57476f6b 652 if (st->gotcrc != st->realcrc) {
8d5de777 653 bombout(("Incorrect CRC received on packet"));
32874aea 654 crReturn(0);
fb09bf1c 655 }
572f871e 656
4ba9b64b 657 pktin.body = pktin.data + st->pad + 1;
658
659 if (ssh1_compressing) {
660 unsigned char *decompblk;
661 int decomplen;
765c4200 662#ifdef DUMP_PACKETS
663 debug(("Packet payload pre-decompression:\n"));
32874aea 664 dmemdump(pktin.body - 1, pktin.length + 1);
4ba9b64b 665#endif
32874aea 666 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
4ba9b64b 667 &decompblk, &decomplen);
668
669 if (pktin.maxlen < st->pad + decomplen) {
670 pktin.maxlen = st->pad + decomplen;
32874aea 671 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
672 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 673 if (!pktin.data)
674 fatalbox("Out of memory");
675 }
676
32874aea 677 memcpy(pktin.body - 1, decompblk, decomplen);
dcbde236 678 sfree(decompblk);
32874aea 679 pktin.length = decomplen - 1;
765c4200 680#ifdef DUMP_PACKETS
681 debug(("Packet payload post-decompression:\n"));
32874aea 682 dmemdump(pktin.body - 1, pktin.length + 1);
4ba9b64b 683#endif
684 }
685
e5574168 686 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 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) {
fb09bf1c 691 long strlen = GET_32BIT(pktin.body);
8d5de777 692 if (strlen + 4 != pktin.length) {
693 bombout(("Received data packet with bogus string length"));
32874aea 694 crReturn(0);
695 }
fb09bf1c 696 }
697
4ba9b64b 698 pktin.type = pktin.body[-1];
699
e5574168 700 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 701 /* log debug message */
702 char buf[80];
703 int strlen = GET_32BIT(pktin.body);
704 strcpy(buf, "Remote: ");
32874aea 705 if (strlen > 70)
706 strlen = 70;
707 memcpy(buf + 8, pktin.body + 4, strlen);
708 buf[8 + strlen] = '\0';
fb09bf1c 709 logevent(buf);
710 goto next_packet;
e5574168 711 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 712 /* do nothing */
713 goto next_packet;
714 }
715
38c4a8da 716 if (pktin.type == SSH1_MSG_DISCONNECT) {
717 /* log reason code in disconnect message */
718 char buf[256];
260f3dec 719 unsigned msglen = GET_32BIT(pktin.body);
720 unsigned nowlen;
38c4a8da 721 strcpy(buf, "Remote sent disconnect: ");
722 nowlen = strlen(buf);
32874aea 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';
38c4a8da 727 logevent(buf);
4eb195cc 728 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
38c4a8da 729 }
730
fb09bf1c 731 crFinish(0);
732}
733
e5574168 734static int ssh2_rdpkt(unsigned char **data, int *datalen)
735{
960e736a 736 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 737
738 crBegin;
739
32874aea 740 next_packet:
e5574168 741 pktin.type = 0;
742 pktin.length = 0;
960e736a 743 if (sccipher)
32874aea 744 st->cipherblk = sccipher->blksize;
e5574168 745 else
32874aea 746 st->cipherblk = 8;
960e736a 747 if (st->cipherblk < 8)
32874aea 748 st->cipherblk = 8;
960e736a 749
750 if (pktin.maxlen < st->cipherblk) {
751 pktin.maxlen = st->cipherblk;
32874aea 752 pktin.data =
753 (pktin.data ==
754 NULL ? smalloc(st->cipherblk +
755 APIEXTRA) : srealloc(pktin.data,
756 st->cipherblk +
757 APIEXTRA));
e5574168 758 if (!pktin.data)
759 fatalbox("Out of memory");
760 }
761
762 /*
763 * Acquire and decrypt the first block of the packet. This will
764 * contain the length and padding details.
765 */
32874aea 766 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 767 while ((*datalen) == 0)
32874aea 768 crReturn(st->cipherblk - st->i);
960e736a 769 pktin.data[st->i] = *(*data)++;
32874aea 770 (*datalen)--;
e5574168 771 }
772#ifdef FWHACK
32874aea 773 if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */
774 /* FIXME */
e5574168 775 }
776#endif
777 if (sccipher)
32874aea 778 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 779
780 /*
781 * Now get the length and padding figures.
782 */
960e736a 783 st->len = GET_32BIT(pktin.data);
784 st->pad = pktin.data[4];
e5574168 785
786 /*
787 * This enables us to deduce the payload length.
788 */
960e736a 789 st->payload = st->len - st->pad - 1;
e5574168 790
960e736a 791 pktin.length = st->payload + 5;
e5574168 792
793 /*
794 * So now we can work out the total packet length.
795 */
960e736a 796 st->packetlen = st->len + 4;
797 st->maclen = scmac ? scmac->len : 0;
e5574168 798
799 /*
800 * Adjust memory allocation if packet is too big.
801 */
32874aea 802 if (pktin.maxlen < st->packetlen + st->maclen) {
803 pktin.maxlen = st->packetlen + st->maclen;
804 pktin.data =
805 (pktin.data ==
806 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
807 pktin.maxlen
808 +
809 APIEXTRA));
e5574168 810 if (!pktin.data)
811 fatalbox("Out of memory");
812 }
813
814 /*
815 * Read and decrypt the remainder of the packet.
816 */
32874aea 817 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
818 st->i++) {
e5574168 819 while ((*datalen) == 0)
960e736a 820 crReturn(st->packetlen + st->maclen - st->i);
821 pktin.data[st->i] = *(*data)++;
32874aea 822 (*datalen)--;
e5574168 823 }
824 /* Decrypt everything _except_ the MAC. */
825 if (sccipher)
32874aea 826 sccipher->decrypt(pktin.data + st->cipherblk,
827 st->packetlen - st->cipherblk);
e5574168 828
765c4200 829#ifdef DUMP_PACKETS
830 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
831 dmemdump(pktin.data, st->packetlen);
7cca0d81 832#endif
d39f364a 833
e5574168 834 /*
835 * Check the MAC.
836 */
32874aea 837 if (scmac
838 && !scmac->verify(pktin.data, st->len + 4,
839 st->incoming_sequence)) {
8d5de777 840 bombout(("Incorrect MAC received on packet"));
32874aea 841 crReturn(0);
8d5de777 842 }
32874aea 843 st->incoming_sequence++; /* whether or not we MACed */
e5574168 844
4ba9b64b 845 /*
846 * Decompress packet payload.
847 */
848 {
849 unsigned char *newpayload;
850 int newlen;
32874aea 851 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
4ba9b64b 852 &newpayload, &newlen)) {
32874aea 853 if (pktin.maxlen < newlen + 5) {
854 pktin.maxlen = newlen + 5;
855 pktin.data =
856 (pktin.data ==
857 NULL ? smalloc(pktin.maxlen +
858 APIEXTRA) : srealloc(pktin.data,
859 pktin.maxlen +
860 APIEXTRA));
4ba9b64b 861 if (!pktin.data)
862 fatalbox("Out of memory");
863 }
864 pktin.length = 5 + newlen;
32874aea 865 memcpy(pktin.data + 5, newpayload, newlen);
765c4200 866#ifdef DUMP_PACKETS
867 debug(("Post-decompression payload:\n"));
32874aea 868 dmemdump(pktin.data + 5, newlen);
4ba9b64b 869#endif
870
dcbde236 871 sfree(newpayload);
4ba9b64b 872 }
873 }
874
e5574168 875 pktin.savedpos = 6;
876 pktin.type = pktin.data[5];
e5574168 877
7cca0d81 878 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
32874aea 879 goto next_packet; /* FIXME: print DEBUG message */
e5574168 880
38c4a8da 881 if (pktin.type == SSH2_MSG_DISCONNECT) {
882 /* log reason code in disconnect message */
883 char buf[256];
32874aea 884 int reason = GET_32BIT(pktin.data + 6);
885 unsigned msglen = GET_32BIT(pktin.data + 10);
260f3dec 886 unsigned nowlen;
38c4a8da 887 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
888 sprintf(buf, "Received disconnect message (%s)",
889 ssh2_disconnect_reasons[reason]);
890 } else {
32874aea 891 sprintf(buf, "Received disconnect message (unknown type %d)",
892 reason);
38c4a8da 893 }
894 logevent(buf);
895 strcpy(buf, "Disconnection message text: ");
896 nowlen = strlen(buf);
32874aea 897 if (msglen > sizeof(buf) - nowlen - 1)
898 msglen = sizeof(buf) - nowlen - 1;
899 memcpy(buf + nowlen, pktin.data + 14, msglen);
900 buf[nowlen + msglen] = '\0';
38c4a8da 901 logevent(buf);
4eb195cc 902 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
903 reason,
904 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
905 ssh2_disconnect_reasons[reason] : "unknown",
906 buf+nowlen));
38c4a8da 907 }
908
e5574168 909 crFinish(0);
910}
911
32874aea 912static void ssh1_pktout_size(int len)
913{
374330e2 914 int pad, biglen;
915
916 len += 5; /* type and CRC */
32874aea 917 pad = 8 - (len % 8);
374330e2 918 biglen = len + pad;
919
32874aea 920 pktout.length = len - 5;
374330e2 921 if (pktout.maxlen < biglen) {
922 pktout.maxlen = biglen;
8f203108 923#ifdef MSCRYPTOAPI
fb09bf1c 924 /* Allocate enough buffer space for extra block
8f203108 925 * for MS CryptEncrypt() */
32874aea 926 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
927 srealloc(pktout.data, biglen + 12));
8f203108 928#else
32874aea 929 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
930 srealloc(pktout.data, biglen + 4));
8f203108 931#endif
374330e2 932 if (!pktout.data)
933 fatalbox("Out of memory");
934 }
32874aea 935 pktout.body = pktout.data + 4 + pad + 1;
4ba9b64b 936}
374330e2 937
32874aea 938static void s_wrpkt_start(int type, int len)
939{
4ba9b64b 940 ssh1_pktout_size(len);
374330e2 941 pktout.type = type;
374330e2 942}
943
32874aea 944static int s_wrpkt_prepare(void)
945{
374330e2 946 int pad, len, biglen, i;
947 unsigned long crc;
948
4ba9b64b 949 pktout.body[-1] = pktout.type;
950
765c4200 951#ifdef DUMP_PACKETS
7d503c31 952 debug(("Packet payload pre-compression:\n"));
32874aea 953 dmemdump(pktout.body - 1, pktout.length + 1);
7d503c31 954#endif
955
4ba9b64b 956 if (ssh1_compressing) {
957 unsigned char *compblk;
958 int complen;
32874aea 959 zlib_compress_block(pktout.body - 1, pktout.length + 1,
4ba9b64b 960 &compblk, &complen);
32874aea 961 ssh1_pktout_size(complen - 1);
962 memcpy(pktout.body - 1, compblk, complen);
dcbde236 963 sfree(compblk);
765c4200 964#ifdef DUMP_PACKETS
4ba9b64b 965 debug(("Packet payload post-compression:\n"));
32874aea 966 dmemdump(pktout.body - 1, pktout.length + 1);
4ba9b64b 967#endif
968 }
969
374330e2 970 len = pktout.length + 5; /* type and CRC */
32874aea 971 pad = 8 - (len % 8);
374330e2 972 biglen = len + pad;
973
32874aea 974 for (i = 0; i < pad; i++)
975 pktout.data[i + 4] = random_byte();
976 crc = crc32(pktout.data + 4, biglen - 4);
977 PUT_32BIT(pktout.data + biglen, crc);
fb09bf1c 978 PUT_32BIT(pktout.data, len);
374330e2 979
765c4200 980#ifdef DUMP_PACKETS
32874aea 981 debug(("Sending packet len=%d\n", biglen + 4));
982 dmemdump(pktout.data, biglen + 4);
698a5108 983#endif
374330e2 984 if (cipher)
32874aea 985 cipher->encrypt(pktout.data + 4, biglen);
374330e2 986
32874aea 987 return biglen + 4;
39065bed 988}
989
32874aea 990static void s_wrpkt(void)
991{
5471d09a 992 int len, backlog;
39065bed 993 len = s_wrpkt_prepare();
5471d09a 994 backlog = sk_write(s, pktout.data, len);
995 if (backlog > SSH_MAX_BACKLOG)
996 ssh_throttle_all(1, backlog);
39065bed 997}
998
32874aea 999static void s_wrpkt_defer(void)
1000{
39065bed 1001 int len;
1002 len = s_wrpkt_prepare();
1003 if (deferred_len + len > deferred_size) {
32874aea 1004 deferred_size = deferred_len + len + 128;
1005 deferred_send_data = srealloc(deferred_send_data, deferred_size);
39065bed 1006 }
32874aea 1007 memcpy(deferred_send_data + deferred_len, pktout.data, len);
39065bed 1008 deferred_len += len;
374330e2 1009}
1010
fb09bf1c 1011/*
39065bed 1012 * Construct a packet with the specified contents.
fb09bf1c 1013 */
39065bed 1014static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1015{
fb09bf1c 1016 unsigned char *p, *argp, argchar;
1017 unsigned long argint;
1018 int pktlen, argtype, arglen;
7cca0d81 1019 Bignum bn;
fb09bf1c 1020
1021 pktlen = 0;
39065bed 1022 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1023 switch (argtype) {
1024 case PKT_INT:
39065bed 1025 (void) va_arg(ap1, int);
fb09bf1c 1026 pktlen += 4;
1027 break;
1028 case PKT_CHAR:
39065bed 1029 (void) va_arg(ap1, char);
fb09bf1c 1030 pktlen++;
1031 break;
1032 case PKT_DATA:
39065bed 1033 (void) va_arg(ap1, unsigned char *);
1034 arglen = va_arg(ap1, int);
fb09bf1c 1035 pktlen += arglen;
1036 break;
1037 case PKT_STR:
39065bed 1038 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1039 arglen = strlen(argp);
1040 pktlen += 4 + arglen;
1041 break;
7cca0d81 1042 case PKT_BIGNUM:
39065bed 1043 bn = va_arg(ap1, Bignum);
32874aea 1044 pktlen += ssh1_bignum_length(bn);
7cca0d81 1045 break;
fb09bf1c 1046 default:
1047 assert(0);
1048 }
1049 }
fb09bf1c 1050
1051 s_wrpkt_start(pkttype, pktlen);
1052 p = pktout.body;
1053
39065bed 1054 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1055 switch (argtype) {
1056 case PKT_INT:
39065bed 1057 argint = va_arg(ap2, int);
fb09bf1c 1058 PUT_32BIT(p, argint);
1059 p += 4;
1060 break;
1061 case PKT_CHAR:
39065bed 1062 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1063 *p = argchar;
1064 p++;
1065 break;
1066 case PKT_DATA:
39065bed 1067 argp = va_arg(ap2, unsigned char *);
1068 arglen = va_arg(ap2, int);
fb09bf1c 1069 memcpy(p, argp, arglen);
1070 p += arglen;
1071 break;
1072 case PKT_STR:
39065bed 1073 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1074 arglen = strlen(argp);
1075 PUT_32BIT(p, arglen);
1076 memcpy(p + 4, argp, arglen);
1077 p += 4 + arglen;
1078 break;
7cca0d81 1079 case PKT_BIGNUM:
39065bed 1080 bn = va_arg(ap2, Bignum);
32874aea 1081 p += ssh1_write_bignum(p, bn);
7cca0d81 1082 break;
fb09bf1c 1083 }
1084 }
39065bed 1085}
fb09bf1c 1086
32874aea 1087static void send_packet(int pkttype, ...)
1088{
39065bed 1089 va_list ap1, ap2;
1090 va_start(ap1, pkttype);
1091 va_start(ap2, pkttype);
1092 construct_packet(pkttype, ap1, ap2);
fb09bf1c 1093 s_wrpkt();
1094}
1095
32874aea 1096static void defer_packet(int pkttype, ...)
1097{
39065bed 1098 va_list ap1, ap2;
1099 va_start(ap1, pkttype);
1100 va_start(ap2, pkttype);
1101 construct_packet(pkttype, ap1, ap2);
1102 s_wrpkt_defer();
1103}
1104
32874aea 1105static int ssh_versioncmp(char *a, char *b)
1106{
9697bfd2 1107 char *ae, *be;
1108 unsigned long av, bv;
1109
43aa02a7 1110 av = strtoul(a, &ae, 10);
1111 bv = strtoul(b, &be, 10);
32874aea 1112 if (av != bv)
1113 return (av < bv ? -1 : +1);
1114 if (*ae == '.')
1115 ae++;
1116 if (*be == '.')
1117 be++;
43aa02a7 1118 av = strtoul(ae, &ae, 10);
1119 bv = strtoul(be, &be, 10);
32874aea 1120 if (av != bv)
1121 return (av < bv ? -1 : +1);
9697bfd2 1122 return 0;
1123}
1124
e5574168 1125
1126/*
a92dd380 1127 * Utility routines for putting an SSH-protocol `string' and
1128 * `uint32' into a SHA state.
e5574168 1129 */
1130#include <stdio.h>
32874aea 1131static void sha_string(SHA_State * s, void *str, int len)
1132{
e5574168 1133 unsigned char lenblk[4];
e5574168 1134 PUT_32BIT(lenblk, len);
e5574168 1135 SHA_Bytes(s, lenblk, 4);
e5574168 1136 SHA_Bytes(s, str, len);
1137}
1138
32874aea 1139static void sha_uint32(SHA_State * s, unsigned i)
1140{
a92dd380 1141 unsigned char intblk[4];
1142 PUT_32BIT(intblk, i);
1143 SHA_Bytes(s, intblk, 4);
1144}
1145
7cca0d81 1146/*
1147 * SSH2 packet construction functions.
1148 */
32874aea 1149static void ssh2_pkt_ensure(int length)
1150{
783415f8 1151 if (pktout.maxlen < length) {
32874aea 1152 pktout.maxlen = length + 256;
1153 pktout.data =
1154 (pktout.data ==
1155 NULL ? smalloc(pktout.maxlen +
1156 APIEXTRA) : srealloc(pktout.data,
1157 pktout.maxlen +
1158 APIEXTRA));
1159 if (!pktout.data)
1160 fatalbox("Out of memory");
7cca0d81 1161 }
783415f8 1162}
32874aea 1163static void ssh2_pkt_adddata(void *data, int len)
1164{
783415f8 1165 pktout.length += len;
1166 ssh2_pkt_ensure(pktout.length);
32874aea 1167 memcpy(pktout.data + pktout.length - len, data, len);
7cca0d81 1168}
32874aea 1169static void ssh2_pkt_addbyte(unsigned char byte)
1170{
7cca0d81 1171 ssh2_pkt_adddata(&byte, 1);
1172}
32874aea 1173static void ssh2_pkt_init(int pkt_type)
1174{
7cca0d81 1175 pktout.length = 5;
32874aea 1176 ssh2_pkt_addbyte((unsigned char) pkt_type);
7cca0d81 1177}
32874aea 1178static void ssh2_pkt_addbool(unsigned char value)
1179{
7cca0d81 1180 ssh2_pkt_adddata(&value, 1);
1181}
32874aea 1182static void ssh2_pkt_adduint32(unsigned long value)
1183{
7cca0d81 1184 unsigned char x[4];
1185 PUT_32BIT(x, value);
1186 ssh2_pkt_adddata(x, 4);
1187}
32874aea 1188static void ssh2_pkt_addstring_start(void)
1189{
7cca0d81 1190 ssh2_pkt_adduint32(0);
1191 pktout.savedpos = pktout.length;
1192}
32874aea 1193static void ssh2_pkt_addstring_str(char *data)
1194{
7cca0d81 1195 ssh2_pkt_adddata(data, strlen(data));
1196 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1197 pktout.length - pktout.savedpos);
7cca0d81 1198}
32874aea 1199static void ssh2_pkt_addstring_data(char *data, int len)
1200{
7cca0d81 1201 ssh2_pkt_adddata(data, len);
1202 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1203 pktout.length - pktout.savedpos);
7cca0d81 1204}
32874aea 1205static void ssh2_pkt_addstring(char *data)
1206{
7cca0d81 1207 ssh2_pkt_addstring_start();
1208 ssh2_pkt_addstring_str(data);
1209}
32874aea 1210static char *ssh2_mpint_fmt(Bignum b, int *len)
1211{
7cca0d81 1212 unsigned char *p;
32874aea 1213 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1214 p = smalloc(n + 1);
7cca0d81 1215 if (!p)
32874aea 1216 fatalbox("out of memory");
7cca0d81 1217 p[0] = 0;
3709bfe9 1218 for (i = 1; i <= n; i++)
32874aea 1219 p[i] = bignum_byte(b, n - i);
7cca0d81 1220 i = 0;
32874aea 1221 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1222 i++;
1223 memmove(p, p + i, n + 1 - i);
1224 *len = n + 1 - i;
7cca0d81 1225 return p;
1226}
32874aea 1227static void ssh2_pkt_addmp(Bignum b)
1228{
7cca0d81 1229 unsigned char *p;
1230 int len;
1231 p = ssh2_mpint_fmt(b, &len);
1232 ssh2_pkt_addstring_start();
1233 ssh2_pkt_addstring_data(p, len);
dcbde236 1234 sfree(p);
7cca0d81 1235}
b185170a 1236
1237/*
1238 * Construct an SSH2 final-form packet: compress it, encrypt it,
1239 * put the MAC on it. Final packet, ready to be sent, is stored in
1240 * pktout.data. Total length is returned.
1241 */
32874aea 1242static int ssh2_pkt_construct(void)
1243{
7cca0d81 1244 int cipherblk, maclen, padding, i;
1245 static unsigned long outgoing_sequence = 0;
1246
1247 /*
4ba9b64b 1248 * Compress packet payload.
1249 */
765c4200 1250#ifdef DUMP_PACKETS
1251 debug(("Pre-compression payload:\n"));
32874aea 1252 dmemdump(pktout.data + 5, pktout.length - 5);
4ba9b64b 1253#endif
1254 {
1255 unsigned char *newpayload;
1256 int newlen;
32874aea 1257 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
4ba9b64b 1258 &newpayload, &newlen)) {
1259 pktout.length = 5;
1260 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1261 sfree(newpayload);
4ba9b64b 1262 }
1263 }
1264
1265 /*
7cca0d81 1266 * Add padding. At least four bytes, and must also bring total
1267 * length (minus MAC) up to a multiple of the block size.
1268 */
32874aea 1269 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1270 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1271 padding = 4;
32874aea 1272 padding +=
1273 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1274 maclen = csmac ? csmac->len : 0;
1275 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1276 pktout.data[4] = padding;
1277 for (i = 0; i < padding; i++)
32874aea 1278 pktout.data[pktout.length + i] = random_byte();
7cca0d81 1279 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1280 if (csmac)
32874aea 1281 csmac->generate(pktout.data, pktout.length + padding,
1282 outgoing_sequence);
1283 outgoing_sequence++; /* whether or not we MACed */
7cca0d81 1284
765c4200 1285#ifdef DUMP_PACKETS
32874aea 1286 debug(("Sending packet len=%d\n", pktout.length + padding));
1287 dmemdump(pktout.data, pktout.length + padding);
7cca0d81 1288#endif
1289
1290 if (cscipher)
32874aea 1291 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1292
b185170a 1293 /* Ready-to-send packet starts at pktout.data. We return length. */
1294 return pktout.length + padding + maclen;
1295}
1296
1297/*
1298 * Construct and send an SSH2 packet immediately.
1299 */
32874aea 1300static void ssh2_pkt_send(void)
1301{
5471d09a 1302 int len;
1303 int backlog;
1304 len = ssh2_pkt_construct();
1305 backlog = sk_write(s, pktout.data, len);
1306 if (backlog > SSH_MAX_BACKLOG)
1307 ssh_throttle_all(1, backlog);
b185170a 1308}
1309
1310/*
1311 * Construct an SSH2 packet and add it to a deferred data block.
1312 * Useful for sending multiple packets in a single sk_write() call,
1313 * to prevent a traffic-analysing listener from being able to work
1314 * out the length of any particular packet (such as the password
1315 * packet).
1316 *
1317 * Note that because SSH2 sequence-numbers its packets, this can
1318 * NOT be used as an m4-style `defer' allowing packets to be
1319 * constructed in one order and sent in another.
1320 */
32874aea 1321static void ssh2_pkt_defer(void)
1322{
b185170a 1323 int len = ssh2_pkt_construct();
1324 if (deferred_len + len > deferred_size) {
32874aea 1325 deferred_size = deferred_len + len + 128;
1326 deferred_send_data = srealloc(deferred_send_data, deferred_size);
b185170a 1327 }
32874aea 1328 memcpy(deferred_send_data + deferred_len, pktout.data, len);
b185170a 1329 deferred_len += len;
1330}
1331
1332/*
1333 * Send the whole deferred data block constructed by
39065bed 1334 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1335 */
32874aea 1336static void ssh_pkt_defersend(void)
1337{
5471d09a 1338 int backlog;
1339 backlog = sk_write(s, deferred_send_data, deferred_len);
b185170a 1340 deferred_len = deferred_size = 0;
1341 sfree(deferred_send_data);
1342 deferred_send_data = NULL;
5471d09a 1343 if (backlog > SSH_MAX_BACKLOG)
1344 ssh_throttle_all(1, backlog);
7cca0d81 1345}
1346
1347#if 0
32874aea 1348void bndebug(char *string, Bignum b)
1349{
7cca0d81 1350 unsigned char *p;
1351 int i, len;
1352 p = ssh2_mpint_fmt(b, &len);
1353 debug(("%s", string));
1354 for (i = 0; i < len; i++)
32874aea 1355 debug((" %02x", p[i]));
765c4200 1356 debug(("\n"));
dcbde236 1357 sfree(p);
7cca0d81 1358}
1359#endif
1360
32874aea 1361static void sha_mpint(SHA_State * s, Bignum b)
1362{
7cca0d81 1363 unsigned char *p;
1364 int len;
1365 p = ssh2_mpint_fmt(b, &len);
1366 sha_string(s, p, len);
dcbde236 1367 sfree(p);
7cca0d81 1368}
1369
1370/*
1371 * SSH2 packet decode functions.
1372 */
32874aea 1373static unsigned long ssh2_pkt_getuint32(void)
1374{
7cca0d81 1375 unsigned long value;
1376 if (pktin.length - pktin.savedpos < 4)
32874aea 1377 return 0; /* arrgh, no way to decline (FIXME?) */
1378 value = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1379 pktin.savedpos += 4;
1380 return value;
1381}
32874aea 1382static int ssh2_pkt_getbool(void)
1383{
65a22376 1384 unsigned long value;
1385 if (pktin.length - pktin.savedpos < 1)
32874aea 1386 return 0; /* arrgh, no way to decline (FIXME?) */
65a22376 1387 value = pktin.data[pktin.savedpos] != 0;
1388 pktin.savedpos++;
1389 return value;
1390}
32874aea 1391static void ssh2_pkt_getstring(char **p, int *length)
1392{
7cca0d81 1393 *p = NULL;
1394 if (pktin.length - pktin.savedpos < 4)
32874aea 1395 return;
1396 *length = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1397 pktin.savedpos += 4;
1398 if (pktin.length - pktin.savedpos < *length)
32874aea 1399 return;
1400 *p = pktin.data + pktin.savedpos;
7cca0d81 1401 pktin.savedpos += *length;
1402}
32874aea 1403static Bignum ssh2_pkt_getmp(void)
1404{
7cca0d81 1405 char *p;
3709bfe9 1406 int length;
7cca0d81 1407 Bignum b;
1408
1409 ssh2_pkt_getstring(&p, &length);
1410 if (!p)
32874aea 1411 return NULL;
8d5de777 1412 if (p[0] & 0x80) {
32874aea 1413 bombout(("internal error: Can't handle negative mpints"));
1414 return NULL;
8d5de777 1415 }
3709bfe9 1416 b = bignum_from_bytes(p, length);
7cca0d81 1417 return b;
1418}
1419
7d503c31 1420/*
1421 * Examine the remote side's version string and compare it against
1422 * a list of known buggy implementations.
1423 */
32874aea 1424static void ssh_detect_bugs(char *vstring)
1425{
1426 char *imp; /* pointer to implementation part */
7d503c31 1427 imp = vstring;
1428 imp += strcspn(imp, "-");
32874aea 1429 if (*imp)
1430 imp++;
7d503c31 1431 imp += strcspn(imp, "-");
32874aea 1432 if (*imp)
1433 imp++;
7d503c31 1434
1435 ssh_remote_bugs = 0;
1436
1437 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
32874aea 1438 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1439 !strcmp(imp, "1.2.22")) {
1440 /*
1441 * These versions don't support SSH1_MSG_IGNORE, so we have
1442 * to use a different defence against password length
1443 * sniffing.
1444 */
1445 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1446 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1447 }
1448
1449 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
32874aea 1450 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1451 !strncmp(imp, "2.1 ", 4)) {
1452 /*
1453 * These versions have the HMAC bug.
1454 */
1455 ssh_remote_bugs |= BUG_SSH2_HMAC;
1456 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1457 }
1458}
1459
32874aea 1460static int do_ssh_init(unsigned char c)
1461{
2d466ffd 1462 static int vslen;
8df7a775 1463 static char version[10];
50526e47 1464 static char *vstring;
1465 static int vstrsize;
1466 static char *vlog;
8df7a775 1467 static int i;
374330e2 1468
8df7a775 1469 crBegin;
1470
1471 /* Search for the string "SSH-" in the input. */
374330e2 1472 i = 0;
8df7a775 1473 while (1) {
1474 static const int transS[] = { 1, 2, 2, 1 };
1475 static const int transH[] = { 0, 0, 3, 0 };
1476 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1477 if (c == 'S')
1478 i = transS[i];
1479 else if (c == 'H')
1480 i = transH[i];
1481 else if (c == '-')
1482 i = transminus[i];
1483 else
1484 i = 0;
8df7a775 1485 if (i < 0)
1486 break;
1487 crReturn(1); /* get another character */
374330e2 1488 }
8df7a775 1489
50526e47 1490 vstring = smalloc(16);
1491 vstrsize = 16;
c5e9c988 1492 strcpy(vstring, "SSH-");
50526e47 1493 vslen = 4;
374330e2 1494 i = 0;
1495 while (1) {
8df7a775 1496 crReturn(1); /* get another char */
32874aea 1497 if (vslen >= vstrsize - 1) {
1498 vstrsize += 16;
1499 vstring = srealloc(vstring, vstrsize);
1500 }
1501 vstring[vslen++] = c;
374330e2 1502 if (i >= 0) {
1503 if (c == '-') {
1504 version[i] = '\0';
1505 i = -1;
32874aea 1506 } else if (i < sizeof(version) - 1)
374330e2 1507 version[i++] = c;
32874aea 1508 } else if (c == '\n')
374330e2 1509 break;
1510 }
1511
db7d555c 1512 ssh_agentfwd_enabled = FALSE;
960e736a 1513 rdpkt2_state.incoming_sequence = 0;
1514
50526e47 1515 vstring[vslen] = 0;
9275ca8a 1516 vlog = smalloc(20 + vslen);
c5e9c988 1517 sprintf(vlog, "Server version: %s", vstring);
7d503c31 1518 ssh_detect_bugs(vstring);
c5e9c988 1519 vlog[strcspn(vlog, "\r\n")] = '\0';
1520 logevent(vlog);
9275ca8a 1521 sfree(vlog);
c5e9c988 1522
adf799dd 1523 /*
1524 * Server version "1.99" means we can choose whether we use v1
1525 * or v2 protocol. Choice is based on cfg.sshprot.
1526 */
1527 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
32874aea 1528 /*
1529 * This is a v2 server. Begin v2 protocol.
1530 */
1531 char verstring[80], vlog[100];
1532 sprintf(verstring, "SSH-2.0-%s", sshver);
1533 SHA_Init(&exhashbase);
1534 /*
1535 * Hash our version string and their version string.
1536 */
1537 sha_string(&exhashbase, verstring, strlen(verstring));
1538 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1539 sprintf(vlog, "We claim version: %s", verstring);
1540 logevent(vlog);
1541 strcat(verstring, "\n");
1542 logevent("Using SSH protocol version 2");
1543 sk_write(s, verstring, strlen(verstring));
1544 ssh_protocol = ssh2_protocol;
1545 ssh_version = 2;
1546 s_rdpkt = ssh2_rdpkt;
e5574168 1547 } else {
32874aea 1548 /*
1549 * This is a v1 server. Begin v1 protocol.
1550 */
1551 char verstring[80], vlog[100];
1552 sprintf(verstring, "SSH-%s-%s",
1553 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1554 sshver);
1555 sprintf(vlog, "We claim version: %s", verstring);
1556 logevent(vlog);
1557 strcat(verstring, "\n");
1558 logevent("Using SSH protocol version 1");
1559 sk_write(s, verstring, strlen(verstring));
1560 ssh_protocol = ssh1_protocol;
1561 ssh_version = 1;
1562 s_rdpkt = ssh1_rdpkt;
e5574168 1563 }
3687d221 1564 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1565
50526e47 1566 sfree(vstring);
50526e47 1567
8df7a775 1568 crFinish(0);
1569}
1570
1571static void ssh_gotdata(unsigned char *data, int datalen)
1572{
1573 crBegin;
1574
1575 /*
1576 * To begin with, feed the characters one by one to the
1577 * protocol initialisation / selection function do_ssh_init().
1578 * When that returns 0, we're done with the initial greeting
1579 * exchange and can move on to packet discipline.
1580 */
1581 while (1) {
1582 int ret;
1583 if (datalen == 0)
1584 crReturnV; /* more data please */
1585 ret = do_ssh_init(*data);
32874aea 1586 data++;
1587 datalen--;
8df7a775 1588 if (ret == 0)
1589 break;
1590 }
1591
1592 /*
1593 * We emerge from that loop when the initial negotiation is
1594 * over and we have selected an s_rdpkt function. Now pass
1595 * everything to s_rdpkt, and then pass the resulting packets
1596 * to the proper protocol handler.
1597 */
1598 if (datalen == 0)
1599 crReturnV;
1600 while (1) {
1601 while (datalen > 0) {
32874aea 1602 if (s_rdpkt(&data, &datalen) == 0) {
8df7a775 1603 ssh_protocol(NULL, 0, 1);
1604 if (ssh_state == SSH_STATE_CLOSED) {
1605 return;
1606 }
1607 }
1608 }
1609 crReturnV;
1610 }
1611 crFinishV;
1612}
1613
32874aea 1614static int ssh_closing(Plug plug, char *error_msg, int error_code,
1615 int calling_back)
1616{
7e78000d 1617 ssh_state = SSH_STATE_CLOSED;
f3ab576e 1618 if (s) {
1619 sk_close(s);
1620 s = NULL;
1621 }
7e78000d 1622 if (error_msg) {
32874aea 1623 /* A socket error has occurred. */
1624 connection_fatal(error_msg);
7e78000d 1625 } else {
1626 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1627 }
7e78000d 1628 return 0;
1629}
1630
32874aea 1631static int ssh_receive(Plug plug, int urgent, char *data, int len)
1632{
1633 ssh_gotdata(data, len);
3257deae 1634 if (ssh_state == SSH_STATE_CLOSED) {
32874aea 1635 if (s) {
1636 sk_close(s);
1637 s = NULL;
1638 }
1639 return 0;
3257deae 1640 }
fef97f43 1641 return 1;
374330e2 1642}
1643
5471d09a 1644static void ssh_sent(Plug plug, int bufsize)
1645{
1646 /*
1647 * If the send backlog on the SSH socket itself clears, we
1648 * should unthrottle the whole world if it was throttled.
1649 */
1650 if (bufsize < SSH_MAX_BACKLOG)
1651 ssh_throttle_all(0, bufsize);
1652}
1653
fb09bf1c 1654/*
8df7a775 1655 * Connect to specified host and port.
1656 * Returns an error message, or NULL on success.
6e1ebb76 1657 * Also places the canonical host name into `realhost'. It must be
1658 * freed by the caller.
8df7a775 1659 */
1660static char *connect_to_host(char *host, int port, char **realhost)
1661{
7e78000d 1662 static struct plug_function_table fn_table = {
1663 ssh_closing,
5471d09a 1664 ssh_receive,
1665 ssh_sent,
1666 NULL
7e78000d 1667 }, *fn_table_ptr = &fn_table;
1668
8df7a775 1669 SockAddr addr;
1670 char *err;
1671#ifdef FWHACK
1672 char *FWhost;
1673 int FWport;
1674#endif
1675
32874aea 1676 savedhost = smalloc(1 + strlen(host));
8df7a775 1677 if (!savedhost)
1678 fatalbox("Out of memory");
1679 strcpy(savedhost, host);
1680
1681 if (port < 0)
1682 port = 22; /* default ssh port */
1683 savedport = port;
1684
1685#ifdef FWHACK
1686 FWhost = host;
1687 FWport = port;
1688 host = FWSTR;
1689 port = 23;
1690#endif
1691
1692 /*
1693 * Try to find host.
1694 */
3ad9d396 1695 {
1696 char buf[200];
1697 sprintf(buf, "Looking up host \"%.170s\"", host);
1698 logevent(buf);
1699 }
8df7a775 1700 addr = sk_namelookup(host, realhost);
32874aea 1701 if ((err = sk_addr_error(addr)))
8df7a775 1702 return err;
1703
1704#ifdef FWHACK
6e1ebb76 1705 *realhost = strdup(FWhost);
8df7a775 1706#endif
1707
1708 /*
1709 * Open socket.
1710 */
3ad9d396 1711 {
1712 char buf[200], addrbuf[100];
1713 sk_getaddr(addr, addrbuf, 100);
1714 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1715 logevent(buf);
1716 }
7e78000d 1717 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
32874aea 1718 if ((err = sk_socket_error(s)))
8df7a775 1719 return err;
1720
1721#ifdef FWHACK
1722 sk_write(s, "connect ", 8);
1723 sk_write(s, FWhost, strlen(FWhost));
1724 {
1725 char buf[20];
1726 sprintf(buf, " %d\n", FWport);
1727 sk_write(s, buf, strlen(buf));
1728 }
1729#endif
1730
1731 return NULL;
1732}
1733
1734/*
5471d09a 1735 * Throttle or unthrottle the SSH connection.
1736 */
1737static void ssh1_throttle(int adjust)
1738{
1739 int old_count = ssh1_throttle_count;
1740 ssh1_throttle_count += adjust;
1741 assert(ssh1_throttle_count >= 0);
1742 if (ssh1_throttle_count && !old_count) {
1743 sk_set_frozen(s, 1);
1744 } else if (!ssh1_throttle_count && old_count) {
1745 sk_set_frozen(s, 0);
1746 }
1747}
1748
1749/*
1750 * Throttle or unthrottle _all_ local data streams (for when sends
1751 * on the SSH connection itself back up).
1752 */
1753static void ssh_throttle_all(int enable, int bufsize)
1754{
1755 int i;
1756 struct ssh_channel *c;
1757
1758 if (enable == ssh_throttled_all)
1759 return;
1760 ssh_throttled_all = enable;
1761 ssh_overall_bufsize = bufsize;
1762 if (!ssh_channels)
1763 return;
1764 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
1765 switch (c->type) {
1766 case CHAN_MAINSESSION:
1767 /*
1768 * This is treated separately, outside the switch.
1769 */
1770 break;
1771 case CHAN_X11:
1772 x11_override_throttle(c->u.x11.s, enable);
1773 break;
1774 case CHAN_AGENT:
1775 /* Agent channels require no buffer management. */
1776 break;
1777 case CHAN_SOCKDATA:
1778 pfd_override_throttle(c->u.x11.s, enable);
1779 break;
1780 }
1781 }
1782}
1783
1784/*
fb09bf1c 1785 * Handle the key exchange and user authentication phases.
1786 */
e5574168 1787static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1788{
2d466ffd 1789 int i, j;
1790 static int len;
1791 static unsigned char *rsabuf, *keystr1, *keystr2;
374330e2 1792 unsigned char cookie[8];
1793 struct RSAKey servkey, hostkey;
1794 struct MD5Context md5c;
ccbfb941 1795 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1796 static int tried_publickey;
1797 static unsigned char session_id[16];
2d466ffd 1798 static int cipher_type;
b585ec46 1799 static char username[100];
374330e2 1800
374330e2 1801 crBegin;
1802
32874aea 1803 if (!ispkt)
1804 crWaitUntil(ispkt);
374330e2 1805
8d5de777 1806 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1807 bombout(("Public key packet not received"));
32874aea 1808 crReturn(0);
8d5de777 1809 }
374330e2 1810
c5e9c988 1811 logevent("Received public keys");
374330e2 1812
c5e9c988 1813 memcpy(cookie, pktin.body, 8);
374330e2 1814
32874aea 1815 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1816 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
374330e2 1817
c5e9c988 1818 /*
1c2a93c4 1819 * Log the host key fingerprint.
c5e9c988 1820 */
c5e9c988 1821 {
1822 char logmsg[80];
1c2a93c4 1823 logevent("Host key fingerprint is:");
c5e9c988 1824 strcpy(logmsg, " ");
32874aea 1825 hostkey.comment = NULL;
1826 rsa_fingerprint(logmsg + strlen(logmsg),
1827 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 1828 logevent(logmsg);
1829 }
1830
32874aea 1831 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1832 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1833 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
bea1ef5f 1834
32874aea 1835 ssh1_local_protoflags =
1836 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
b96dc54c 1837 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1838
c5e9c988 1839 MD5Init(&md5c);
374330e2 1840 MD5Update(&md5c, keystr2, hostkey.bytes);
1841 MD5Update(&md5c, keystr1, servkey.bytes);
1842 MD5Update(&md5c, pktin.body, 8);
374330e2 1843 MD5Final(session_id, &md5c);
1844
32874aea 1845 for (i = 0; i < 32; i++)
374330e2 1846 session_key[i] = random_byte();
1847
1848 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1849
dcbde236 1850 rsabuf = smalloc(len);
374330e2 1851 if (!rsabuf)
1852 fatalbox("Out of memory");
1853
89ee5268 1854 /*
1855 * Verify the host key.
1856 */
1857 {
32874aea 1858 /*
1859 * First format the key into a string.
1860 */
1861 int len = rsastr_len(&hostkey);
1862 char fingerprint[100];
1863 char *keystr = smalloc(len);
1864 if (!keystr)
1865 fatalbox("Out of memory");
1866 rsastr_fmt(keystr, &hostkey);
1867 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1868 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1869 fingerprint);
1870 sfree(keystr);
1871 }
1872
1873 for (i = 0; i < 32; i++) {
374330e2 1874 rsabuf[i] = session_key[i];
1875 if (i < 16)
1876 rsabuf[i] ^= session_id[i];
1877 }
1878
1879 if (hostkey.bytes > servkey.bytes) {
1880 rsaencrypt(rsabuf, 32, &servkey);
1881 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1882 } else {
1883 rsaencrypt(rsabuf, 32, &hostkey);
1884 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1885 }
1886
c5e9c988 1887 logevent("Encrypted session key");
1888
ca20bfcf 1889 {
1890 int cipher_chosen = 0, warn = 0;
1891 char *cipher_string = NULL;
1892 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
1893 int next_cipher = cfg.ssh_cipherlist[i];
1894 if (next_cipher == CIPHER_WARN) {
1895 /* If/when we choose a cipher, warn about it */
1896 warn = 1;
1897 } else if (next_cipher == CIPHER_AES) {
1898 /* XXX Probably don't need to mention this. */
1899 logevent("AES not supported in SSH1, skipping");
1900 } else {
1901 switch (next_cipher) {
1902 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
1903 cipher_string = "3DES"; break;
1904 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
1905 cipher_string = "Blowfish"; break;
1906 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
1907 cipher_string = "single-DES"; break;
1908 }
1909 if (supported_ciphers_mask & (1 << cipher_type))
1910 cipher_chosen = 1;
1911 }
1912 }
1913 if (!cipher_chosen) {
1914 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
1915 bombout(("Server violates SSH 1 protocol by not "
1916 "supporting 3DES encryption"));
1917 else
1918 /* shouldn't happen */
1919 bombout(("No supported ciphers found"));
a99a05c0 1920 crReturn(0);
1921 }
ca20bfcf 1922
1923 /* Warn about chosen cipher if necessary. */
1924 if (warn)
1925 askcipher(cipher_string, 0);
bea1ef5f 1926 }
ca20bfcf 1927
c5e9c988 1928 switch (cipher_type) {
32874aea 1929 case SSH_CIPHER_3DES:
1930 logevent("Using 3DES encryption");
1931 break;
1932 case SSH_CIPHER_DES:
1933 logevent("Using single-DES encryption");
1934 break;
1935 case SSH_CIPHER_BLOWFISH:
1936 logevent("Using Blowfish encryption");
1937 break;
c5e9c988 1938 }
bea1ef5f 1939
e5574168 1940 send_packet(SSH1_CMSG_SESSION_KEY,
32874aea 1941 PKT_CHAR, cipher_type,
1942 PKT_DATA, cookie, 8,
1943 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1944 PKT_DATA, rsabuf, len,
1945 PKT_INT, ssh1_local_protoflags, PKT_END);
fb09bf1c 1946
c5e9c988 1947 logevent("Trying to enable encryption...");
374330e2 1948
dcbde236 1949 sfree(rsabuf);
374330e2 1950
5e8358ad 1951 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
32874aea 1952 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
374330e2 1953 cipher->sesskey(session_key);
1954
fb09bf1c 1955 crWaitUntil(ispkt);
374330e2 1956
8d5de777 1957 if (pktin.type != SSH1_SMSG_SUCCESS) {
1958 bombout(("Encryption not successfully enabled"));
32874aea 1959 crReturn(0);
8d5de777 1960 }
374330e2 1961
c5e9c988 1962 logevent("Successfully started encryption");
1963
374330e2 1964 fflush(stdout);
1965 {
374330e2 1966 static int pos = 0;
1967 static char c;
67779be7 1968 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 1969 if (ssh_get_line) {
1970 if (!ssh_get_line("login as: ",
1971 username, sizeof(username), FALSE)) {
1972 /*
1973 * get_line failed to get a username.
1974 * Terminate.
1975 */
1976 logevent("No username provided. Abandoning session.");
1977 ssh_state = SSH_STATE_CLOSED;
1978 crReturn(1);
1979 }
1980 } else {
1981 c_write_str("login as: ");
1982 ssh_send_ok = 1;
1983 while (pos >= 0) {
1984 crWaitUntil(!ispkt);
1985 while (inlen--)
1986 switch (c = *in++) {
1987 case 10:
1988 case 13:
1989 username[pos] = 0;
1990 pos = -1;
1991 break;
1992 case 8:
1993 case 127:
1994 if (pos > 0) {
1995 c_write_str("\b \b");
1996 pos--;
1997 }
1998 break;
1999 case 21:
2000 case 27:
2001 while (pos > 0) {
2002 c_write_str("\b \b");
2003 pos--;
2004 }
2005 break;
2006 case 3:
2007 case 4:
2008 random_save_seed();
2009 exit(0);
2010 break;
2011 default:
2012 if (((c >= ' ' && c <= '~') ||
51b2fb65 2013 ((unsigned char) c >= 160))
2014 && pos < sizeof(username)-1) {
32874aea 2015 username[pos++] = c;
2016 c_write(&c, 1);
2017 }
2018 break;
2019 }
2020 }
2021 c_write_str("\r\n");
2022 username[strcspn(username, "\n\r")] = '\0';
2023 }
2024 } else {
374330e2 2025 strncpy(username, cfg.username, 99);
2026 username[99] = '\0';
374330e2 2027 }
fb09bf1c 2028
e5574168 2029 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 2030 {
32874aea 2031 char userlog[22 + sizeof(username)];
c5e9c988 2032 sprintf(userlog, "Sent username \"%s\"", username);
2033 logevent(userlog);
32874aea 2034 if (flags & FLAG_INTERACTIVE &&
2035 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2036 strcat(userlog, "\r\n");
32874aea 2037 c_write_str(userlog);
3c8e959b 2038 }
c5e9c988 2039 }
374330e2 2040 }
2041
fb09bf1c 2042 crWaitUntil(ispkt);
374330e2 2043
7cca0d81 2044 tried_publickey = 0;
2045
e5574168 2046 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 2047 static char password[100];
a52f067e 2048 static char prompt[200];
374330e2 2049 static int pos;
2050 static char c;
32874aea 2051 static int pwpkt_type;
2052 /*
2053 * Show password prompt, having first obtained it via a TIS
2054 * or CryptoCard exchange if we're doing TIS or CryptoCard
2055 * authentication.
2056 */
2057 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2058 if (agent_exists()) {
2059 /*
2060 * Attempt RSA authentication using Pageant.
2061 */
2062 static unsigned char request[5], *response, *p;
2063 static int responselen;
2064 static int i, nkeys;
2065 static int authed = FALSE;
2066 void *r;
2067
2068 logevent("Pageant is running. Requesting keys.");
2069
2070 /* Request the keys held by the agent. */
2071 PUT_32BIT(request, 1);
2072 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2073 agent_query(request, 5, &r, &responselen);
2074 response = (unsigned char *) r;
2075 if (response && responselen >= 5 &&
2076 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2077 p = response + 5;
2078 nkeys = GET_32BIT(p);
2079 p += 4;
2080 {
2081 char buf[64];
2082 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2083 logevent(buf);
2084 }
2085 for (i = 0; i < nkeys; i++) {
2086 static struct RSAKey key;
2087 static Bignum challenge;
2088 static char *commentp;
2089 static int commentlen;
2090
2091 {
2092 char buf[64];
2093 sprintf(buf, "Trying Pageant key #%d", i);
2094 logevent(buf);
2095 }
2096 p += 4;
2097 p += ssh1_read_bignum(p, &key.exponent);
2098 p += ssh1_read_bignum(p, &key.modulus);
2099 commentlen = GET_32BIT(p);
2100 p += 4;
2101 commentp = p;
2102 p += commentlen;
2103 send_packet(SSH1_CMSG_AUTH_RSA,
2104 PKT_BIGNUM, key.modulus, PKT_END);
2105 crWaitUntil(ispkt);
2106 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2107 logevent("Key refused");
2108 continue;
2109 }
2110 logevent("Received RSA challenge");
2111 ssh1_read_bignum(pktin.body, &challenge);
2112 {
2113 char *agentreq, *q, *ret;
2d466ffd 2114 void *vret;
32874aea 2115 int len, retlen;
2116 len = 1 + 4; /* message type, bit count */
2117 len += ssh1_bignum_length(key.exponent);
2118 len += ssh1_bignum_length(key.modulus);
2119 len += ssh1_bignum_length(challenge);
2120 len += 16; /* session id */
2121 len += 4; /* response format */
2122 agentreq = smalloc(4 + len);
2123 PUT_32BIT(agentreq, len);
2124 q = agentreq + 4;
2125 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2126 PUT_32BIT(q, bignum_bitcount(key.modulus));
2127 q += 4;
2128 q += ssh1_write_bignum(q, key.exponent);
2129 q += ssh1_write_bignum(q, key.modulus);
2130 q += ssh1_write_bignum(q, challenge);
2131 memcpy(q, session_id, 16);
2132 q += 16;
2133 PUT_32BIT(q, 1); /* response format */
2d466ffd 2134 agent_query(agentreq, len + 4, &vret, &retlen);
2135 ret = vret;
32874aea 2136 sfree(agentreq);
2137 if (ret) {
2138 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2139 logevent("Sending Pageant's response");
2140 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2141 PKT_DATA, ret + 5, 16,
2142 PKT_END);
2143 sfree(ret);
2144 crWaitUntil(ispkt);
2145 if (pktin.type == SSH1_SMSG_SUCCESS) {
2146 logevent
2147 ("Pageant's response accepted");
2148 if (flags & FLAG_VERBOSE) {
2149 c_write_str
2150 ("Authenticated using RSA key \"");
2151 c_write(commentp, commentlen);
2152 c_write_str("\" from agent\r\n");
2153 }
2154 authed = TRUE;
2155 } else
2156 logevent
2157 ("Pageant's response not accepted");
2158 } else {
2159 logevent
2160 ("Pageant failed to answer challenge");
2161 sfree(ret);
2162 }
2163 } else {
2164 logevent("No reply received from Pageant");
2165 }
2166 }
2167 freebn(key.exponent);
2168 freebn(key.modulus);
2169 freebn(challenge);
2170 if (authed)
2171 break;
2172 }
2173 }
2174 if (authed)
2175 break;
2176 }
2177 if (*cfg.keyfile && !tried_publickey)
2178 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2179
2180 if (pktin.type == SSH1_SMSG_FAILURE &&
2181 cfg.try_tis_auth &&
2182 (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
2183 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2184 logevent("Requested TIS authentication");
2185 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2186 crWaitUntil(ispkt);
2187 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2188 logevent("TIS authentication declined");
2189 if (flags & FLAG_INTERACTIVE)
2190 c_write_str("TIS authentication refused.\r\n");
2191 } else {
2192 int challengelen = ((pktin.body[0] << 24) |
2193 (pktin.body[1] << 16) |
2194 (pktin.body[2] << 8) |
2195 (pktin.body[3]));
2196 logevent("Received TIS challenge");
2197 if (challengelen > sizeof(prompt) - 1)
2198 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2199 memcpy(prompt, pktin.body + 4, challengelen);
2200 prompt[challengelen] = '\0';
2201 }
2202 }
2203 if (pktin.type == SSH1_SMSG_FAILURE &&
2204 cfg.try_tis_auth &&
2205 (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
2206 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2207 logevent("Requested CryptoCard authentication");
2208 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2209 crWaitUntil(ispkt);
2210 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2211 logevent("CryptoCard authentication declined");
2212 c_write_str("CryptoCard authentication refused.\r\n");
2213 } else {
2214 int challengelen = ((pktin.body[0] << 24) |
2215 (pktin.body[1] << 16) |
2216 (pktin.body[2] << 8) |
2217 (pktin.body[3]));
2218 logevent("Received CryptoCard challenge");
2219 if (challengelen > sizeof(prompt) - 1)
2220 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2221 memcpy(prompt, pktin.body + 4, challengelen);
2222 strncpy(prompt + challengelen, "\r\nResponse : ",
2223 sizeof(prompt) - challengelen);
2224 prompt[sizeof(prompt) - 1] = '\0';
2225 }
2226 }
2227 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2228 sprintf(prompt, "%.90s@%.90s's password: ",
2229 username, savedhost);
2230 }
2231 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2232 char *comment = NULL;
2233 if (flags & FLAG_VERBOSE)
2234 c_write_str("Trying public key authentication.\r\n");
2235 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2236 if (flags & FLAG_VERBOSE)
2237 c_write_str("No passphrase required.\r\n");
2238 goto tryauth;
2239 }
2240 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2241 sfree(comment);
2242 }
a52f067e 2243
fa17a66e 2244 if (ssh_get_line) {
2245 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
32874aea 2246 /*
2247 * get_line failed to get a password (for example
2248 * because one was supplied on the command line
2249 * which has already failed to work). Terminate.
2250 */
2bc6a386 2251 send_packet(SSH1_MSG_DISCONNECT,
2252 PKT_STR, "No more passwords available to try",
2253 PKT_END);
2254 connection_fatal("Unable to authenticate");
32874aea 2255 ssh_state = SSH_STATE_CLOSED;
2256 crReturn(1);
2257 }
fb09bf1c 2258 } else {
32874aea 2259 c_write_str(prompt);
2260 pos = 0;
2261 ssh_send_ok = 1;
2262 while (pos >= 0) {
2263 crWaitUntil(!ispkt);
2264 while (inlen--)
2265 switch (c = *in++) {
2266 case 10:
2267 case 13:
2268 password[pos] = 0;
2269 pos = -1;
2270 break;
2271 case 8:
2272 case 127:
2273 if (pos > 0)
2274 pos--;
2275 break;
2276 case 21:
2277 case 27:
2278 pos = 0;
2279 break;
2280 case 3:
2281 case 4:
2282 random_save_seed();
2283 exit(0);
2284 break;
2285 default:
51b2fb65 2286 if (pos < sizeof(password)-1)
32874aea 2287 password[pos++] = c;
2288 break;
2289 }
2290 }
2291 c_write_str("\r\n");
2292 }
2293
2294 tryauth:
7cca0d81 2295 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2296 /*
2297 * Try public key authentication with the specified
2298 * key file.
2299 */
2300 static struct RSAKey pubkey;
2301 static Bignum challenge, response;
2302 static int i;
2303 static unsigned char buffer[32];
2304
2305 tried_publickey = 1;
2306 i = loadrsakey(cfg.keyfile, &pubkey, password);
2307 if (i == 0) {
7963af2f 2308 c_write_str("Couldn't load private key from ");
32874aea 2309 c_write_str(cfg.keyfile);
2310 c_write_str(".\r\n");
2311 continue; /* go and try password */
2312 }
2313 if (i == -1) {
2314 c_write_str("Wrong passphrase.\r\n");
2315 tried_publickey = 0;
2316 continue; /* try again */
2317 }
2318
2319 /*
2320 * Send a public key attempt.
2321 */
2322 send_packet(SSH1_CMSG_AUTH_RSA,
2323 PKT_BIGNUM, pubkey.modulus, PKT_END);
2324
2325 crWaitUntil(ispkt);
2326 if (pktin.type == SSH1_SMSG_FAILURE) {
2327 c_write_str("Server refused our public key.\r\n");
2328 continue; /* go and try password */
2329 }
2330 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2331 bombout(("Bizarre response to offer of public key"));
2332 crReturn(0);
2333 }
2334 ssh1_read_bignum(pktin.body, &challenge);
2335 response = rsadecrypt(challenge, &pubkey);
2336 freebn(pubkey.private_exponent); /* burn the evidence */
2337
2338 for (i = 0; i < 32; i++) {
2339 buffer[i] = bignum_byte(response, 31 - i);
2340 }
2341
2342 MD5Init(&md5c);
2343 MD5Update(&md5c, buffer, 32);
2344 MD5Update(&md5c, session_id, 16);
2345 MD5Final(buffer, &md5c);
2346
2347 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2348 PKT_DATA, buffer, 16, PKT_END);
2349
2350 crWaitUntil(ispkt);
2351 if (pktin.type == SSH1_SMSG_FAILURE) {
2352 if (flags & FLAG_VERBOSE)
2353 c_write_str
2354 ("Failed to authenticate with our public key.\r\n");
2355 continue; /* go and try password */
2356 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2357 bombout(
2358 ("Bizarre response to RSA authentication response"));
2359 crReturn(0);
2360 }
2361
2362 break; /* we're through! */
2363 } else {
2364 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2365 /*
2366 * Defence against traffic analysis: we send a
2367 * whole bunch of packets containing strings of
2368 * different lengths. One of these strings is the
2369 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2370 * The others are all random data in
2371 * SSH1_MSG_IGNORE packets. This way a passive
2372 * listener can't tell which is the password, and
2373 * hence can't deduce the password length.
2374 *
2375 * Anybody with a password length greater than 16
2376 * bytes is going to have enough entropy in their
2377 * password that a listener won't find it _that_
2378 * much help to know how long it is. So what we'll
2379 * do is:
2380 *
2381 * - if password length < 16, we send 15 packets
2382 * containing string lengths 1 through 15
2383 *
2384 * - otherwise, we let N be the nearest multiple
2385 * of 8 below the password length, and send 8
2386 * packets containing string lengths N through
2387 * N+7. This won't obscure the order of
2388 * magnitude of the password length, but it will
2389 * introduce a bit of extra uncertainty.
2390 *
2391 * A few servers (the old 1.2.18 through 1.2.22)
2392 * can't deal with SSH1_MSG_IGNORE. For these
2393 * servers, we need an alternative defence. We make
2394 * use of the fact that the password is interpreted
2395 * as a C string: so we can append a NUL, then some
2396 * random data.
2397 */
2398 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2399 char string[64];
2400 char *s;
2401 int len;
2402
2403 len = strlen(password);
2404 if (len < sizeof(string)) {
2405 s = string;
2406 strcpy(string, password);
2407 len++; /* cover the zero byte */
2408 while (len < sizeof(string)) {
2409 string[len++] = (char) random_byte();
2410 }
2411 } else {
2412 s = password;
2413 }
2414 send_packet(pwpkt_type, PKT_INT, len,
2415 PKT_DATA, s, len, PKT_END);
2416 } else {
2417 int bottom, top, pwlen, i;
2418 char *randomstr;
2419
2420 pwlen = strlen(password);
2421 if (pwlen < 16) {
2422 bottom = 0; /* zero length passwords are OK! :-) */
2423 top = 15;
2424 } else {
2425 bottom = pwlen & ~7;
2426 top = bottom + 7;
2427 }
2428
2429 assert(pwlen >= bottom && pwlen <= top);
2430
2431 randomstr = smalloc(top + 1);
2432
2433 for (i = bottom; i <= top; i++) {
2434 if (i == pwlen)
2435 defer_packet(pwpkt_type, PKT_STR, password,
2436 PKT_END);
2437 else {
2438 for (j = 0; j < i; j++) {
2439 do {
2440 randomstr[j] = random_byte();
2441 } while (randomstr[j] == '\0');
2442 }
2443 randomstr[i] = '\0';
2444 defer_packet(SSH1_MSG_IGNORE,
2445 PKT_STR, randomstr, PKT_END);
2446 }
2447 }
2448 ssh_pkt_defersend();
2449 }
2450 } else {
2451 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2452 }
2453 }
c5e9c988 2454 logevent("Sent password");
374330e2 2455 memset(password, 0, strlen(password));
fb09bf1c 2456 crWaitUntil(ispkt);
e5574168 2457 if (pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2458 if (flags & FLAG_VERBOSE)
2459 c_write_str("Access denied\r\n");
c5e9c988 2460 logevent("Authentication refused");
e5574168 2461 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2462 logevent("Received disconnect request");
32874aea 2463 ssh_state = SSH_STATE_CLOSED;
85ee8208 2464 crReturn(1);
e5574168 2465 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2466 bombout(("Strange packet received, type %d", pktin.type));
32874aea 2467 crReturn(0);
374330e2 2468 }
2469 }
2470
c5e9c988 2471 logevent("Authentication successful");
2472
fb09bf1c 2473 crFinish(1);
2474}
2475
32874aea 2476void sshfwd_close(struct ssh_channel *c)
2477{
80e48603 2478 if (c && !c->closes) {
32874aea 2479 if (ssh_version == 1) {
2480 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2481 PKT_END);
2482 } else {
2483 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2484 ssh2_pkt_adduint32(c->remoteid);
2485 ssh2_pkt_send();
2486 }
2487 c->closes = 1;
2488 if (c->type == CHAN_X11) {
2489 c->u.x11.s = NULL;
d74d141c 2490 logevent("Forwarded X11 connection terminated");
2491 } else if (c->type == CHAN_SOCKDATA) {
2492 c->u.pfd.s = NULL;
2493 logevent("Forwarded port closed");
32874aea 2494 }
2495 }
2496}
2497
5471d09a 2498int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2499{
783415f8 2500 if (ssh_version == 1) {
32874aea 2501 send_packet(SSH1_MSG_CHANNEL_DATA,
2502 PKT_INT, c->remoteid,
2503 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2504 /*
2505 * In SSH1 we can return 0 here - implying that forwarded
2506 * connections are never individually throttled - because
2507 * the only circumstance that can cause throttling will be
2508 * the whole SSH connection backing up, in which case
2509 * _everything_ will be throttled as a whole.
2510 */
2511 return 0;
783415f8 2512 } else {
32874aea 2513 ssh2_add_channel_data(c, buf, len);
5471d09a 2514 return ssh2_try_send(c);
2515 }
2516}
2517
2518void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2519{
2520 if (ssh_version == 1) {
2521 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2522 c->v.v1.throttling = 0;
2523 ssh1_throttle(-1);
2524 }
2525 } else {
2526 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2527 }
9c964e85 2528}
2529
32874aea 2530static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2531{
fb09bf1c 2532 crBegin;
2533
2534 random_init();
2535
e5574168 2536 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2537 crReturnV;
85ee8208 2538 }
2539 if (ssh_state == SSH_STATE_CLOSED)
32874aea 2540 crReturnV;
fb09bf1c 2541
979310f1 2542 if (cfg.agentfwd && agent_exists()) {
32874aea 2543 logevent("Requesting agent forwarding");
2544 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2545 do {
2546 crReturnV;
2547 } while (!ispkt);
2548 if (pktin.type != SSH1_SMSG_SUCCESS
2549 && pktin.type != SSH1_SMSG_FAILURE) {
2550 bombout(("Protocol confusion"));
2551 crReturnV;
2552 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2553 logevent("Agent forwarding refused");
2554 } else {
2555 logevent("Agent forwarding enabled");
db7d555c 2556 ssh_agentfwd_enabled = TRUE;
2557 }
dacbd0e8 2558 }
2559
9c964e85 2560 if (cfg.x11_forward) {
32874aea 2561 char proto[20], data[64];
2562 logevent("Requesting X11 forwarding");
2563 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2564 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2565 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2566 PKT_STR, proto, PKT_STR, data,
2567 PKT_INT, 0, PKT_END);
2568 } else {
2569 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2570 PKT_STR, proto, PKT_STR, data, PKT_END);
2571 }
2572 do {
2573 crReturnV;
2574 } while (!ispkt);
2575 if (pktin.type != SSH1_SMSG_SUCCESS
2576 && pktin.type != SSH1_SMSG_FAILURE) {
2577 bombout(("Protocol confusion"));
2578 crReturnV;
2579 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2580 logevent("X11 forwarding refused");
2581 } else {
2582 logevent("X11 forwarding enabled");
9c964e85 2583 ssh_X11_fwd_enabled = TRUE;
2584 }
2585 }
2586
d74d141c 2587 {
2588 char type, *e;
2589 int n;
2590 int sport,dport;
2591 char sports[256], dports[256], host[256];
2592 char buf[1024];
2593
bc240b21 2594 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 2595 /* Add port forwardings. */
2596 e = cfg.portfwd;
2597 while (*e) {
2598 type = *e++;
2599 n = 0;
2600 while (*e && *e != '\t')
2601 sports[n++] = *e++;
2602 sports[n] = 0;
2603 if (*e == '\t')
2604 e++;
2605 n = 0;
2606 while (*e && *e != ':')
2607 host[n++] = *e++;
2608 host[n] = 0;
2609 if (*e == ':')
2610 e++;
2611 n = 0;
2612 while (*e)
2613 dports[n++] = *e++;
2614 dports[n] = 0;
2615 e++;
2616 dport = atoi(dports);
2617 sport = atoi(sports);
2618 if (sport && dport) {
2619 if (type == 'L') {
2620 pfd_addforward(host, dport, sport);
2621 sprintf(buf, "Local port %d forwarding to %s:%d",
2622 sport, host, dport);
2623 logevent(buf);
2624 } else {
2625 struct ssh_rportfwd *pf;
2626 pf = smalloc(sizeof(*pf));
bc240b21 2627 strcpy(pf->dhost, host);
2628 pf->dport = dport;
d74d141c 2629 if (add234(ssh_rportfwds, pf) != pf) {
2630 sprintf(buf,
95bc8819 2631 "Duplicate remote port forwarding to %s:%d",
d74d141c 2632 host, dport);
2633 logevent(buf);
bc240b21 2634 sfree(pf);
d74d141c 2635 } else {
2636 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2637 sport, host, dport);
2638 logevent(buf);
2639 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2640 PKT_INT, sport,
2641 PKT_STR, host,
2642 PKT_INT, dport,
2643 PKT_END);
2644 }
2645 }
2646 }
2647 }
2648 }
2649
fef97f43 2650 if (!cfg.nopty) {
e5574168 2651 send_packet(SSH1_CMSG_REQUEST_PTY,
32874aea 2652 PKT_STR, cfg.termtype,
2653 PKT_INT, rows, PKT_INT, cols,
2654 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2655 ssh_state = SSH_STATE_INTERMED;
2656 do {
2657 crReturnV;
2658 } while (!ispkt);
2659 if (pktin.type != SSH1_SMSG_SUCCESS
2660 && pktin.type != SSH1_SMSG_FAILURE) {
2661 bombout(("Protocol confusion"));
2662 crReturnV;
2663 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2664 c_write_str("Server refused to allocate pty\r\n");
2665 ssh_editing = ssh_echoing = 1;
2666 }
c5e9c988 2667 logevent("Allocated pty");
0965bee0 2668 } else {
32874aea 2669 ssh_editing = ssh_echoing = 1;
374330e2 2670 }
2671
4ba9b64b 2672 if (cfg.compression) {
32874aea 2673 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2674 do {
2675 crReturnV;
2676 } while (!ispkt);
2677 if (pktin.type != SSH1_SMSG_SUCCESS
2678 && pktin.type != SSH1_SMSG_FAILURE) {
2679 bombout(("Protocol confusion"));
2680 crReturnV;
2681 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2682 c_write_str("Server refused to compress\r\n");
2683 }
4ba9b64b 2684 logevent("Started compression");
2685 ssh1_compressing = TRUE;
2686 zlib_compress_init();
2687 zlib_decompress_init();
2688 }
2689
fd5e5847 2690 /*
2691 * Start the shell or command.
2692 *
2693 * Special case: if the first-choice command is an SSH2
2694 * subsystem (hence not usable here) and the second choice
2695 * exists, we fall straight back to that.
2696 */
2697 {
2698 char *cmd = cfg.remote_cmd_ptr;
2699
2700 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
2701 cmd = cfg.remote_cmd_ptr2;
2702 ssh_fallback_cmd = TRUE;
2703 }
2704 if (*cmd)
2705 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2706 else
2707 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2708 logevent("Started session");
2709 }
374330e2 2710
2711 ssh_state = SSH_STATE_SESSION;
2712 if (size_needed)
2713 ssh_size();
3687d221 2714 if (eof_needed)
32874aea 2715 ssh_special(TS_EOF);
374330e2 2716
32874aea 2717 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 2718 ssh_send_ok = 1;
dacbd0e8 2719 ssh_channels = newtree234(ssh_channelcmp);
374330e2 2720 while (1) {
2721 crReturnV;
2722 if (ispkt) {
e5574168 2723 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 2724 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2725 long len = GET_32BIT(pktin.body);
5471d09a 2726 int bufsize =
2727 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2728 pktin.body + 4, len);
90347b95 2729 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 2730 ssh1_stdout_throttling = 1;
2731 ssh1_throttle(+1);
2732 }
e5574168 2733 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
32874aea 2734 ssh_state = SSH_STATE_CLOSED;
c5e9c988 2735 logevent("Received disconnect request");
32874aea 2736 crReturnV;
2737 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2738 /* Remote side is trying to open a channel to talk to our
2739 * X-Server. Give them back a local channel number. */
2740 struct ssh_channel *c;
9c964e85 2741
2742 logevent("Received X11 connect request");
2743 /* Refuse if X11 forwarding is disabled. */
2744 if (!ssh_X11_fwd_enabled) {
2745 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2746 PKT_INT, GET_32BIT(pktin.body), PKT_END);
9c964e85 2747 logevent("Rejected X11 connect request");
2748 } else {
9c964e85 2749 c = smalloc(sizeof(struct ssh_channel));
2750
32874aea 2751 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2752 logevent("opening X11 forward connection failed");
2753 sfree(c);
2754 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2755 PKT_INT, GET_32BIT(pktin.body),
2756 PKT_END);
9c964e85 2757 } else {
32874aea 2758 logevent
2759 ("opening X11 forward connection succeeded");
2760 c->remoteid = GET_32BIT(pktin.body);
2761 c->localid = alloc_channel_id();
2762 c->closes = 0;
5471d09a 2763 c->v.v1.throttling = 0;
32874aea 2764 c->type = CHAN_X11; /* identify channel type */
2765 add234(ssh_channels, c);
2766 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2767 PKT_INT, c->remoteid, PKT_INT,
2768 c->localid, PKT_END);
2769 logevent("Opened X11 forward channel");
9c964e85 2770 }
2771 }
32874aea 2772 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2773 /* Remote side is trying to open a channel to talk to our
2774 * agent. Give them back a local channel number. */
2775 struct ssh_channel *c;
db7d555c 2776
2777 /* Refuse if agent forwarding is disabled. */
2778 if (!ssh_agentfwd_enabled) {
2779 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2780 PKT_INT, GET_32BIT(pktin.body), PKT_END);
db7d555c 2781 } else {
dcbde236 2782 c = smalloc(sizeof(struct ssh_channel));
db7d555c 2783 c->remoteid = GET_32BIT(pktin.body);
d2371c81 2784 c->localid = alloc_channel_id();
db7d555c 2785 c->closes = 0;
5471d09a 2786 c->v.v1.throttling = 0;
32874aea 2787 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 2788 c->u.a.lensofar = 0;
2789 add234(ssh_channels, c);
2790 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2791 PKT_INT, c->remoteid, PKT_INT, c->localid,
2792 PKT_END);
2793 }
d74d141c 2794 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2795 /* Remote side is trying to open a channel to talk to a
2796 * forwarded port. Give them back a local channel number. */
2797 struct ssh_channel *c;
2798 struct ssh_rportfwd pf;
2799 int hostsize, port;
2800 char host[256], buf[1024];
2801 char *p, *h, *e;
2802 c = smalloc(sizeof(struct ssh_channel));
2803
2804 hostsize = GET_32BIT(pktin.body+4);
2805 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2806 if (h+1 < host+sizeof(host))
2807 *h++ = *p;
95bc8819 2808 p++;
d74d141c 2809 }
2810 *h = 0;
2811 port = GET_32BIT(p);
2812
bc240b21 2813 strcpy(pf.dhost, host);
2814 pf.dport = port;
d74d141c 2815
2816 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2817 sprintf(buf, "Rejected remote port open request for %s:%d",
2818 host, port);
2819 logevent(buf);
2820 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2821 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2822 } else {
2823 sprintf(buf, "Received remote port open request for %s:%d",
2824 host, port);
2825 logevent(buf);
2826 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2827 if (e != NULL) {
2828 char buf[256];
2829 sprintf(buf, "Port open failed: %s", e);
2830 logevent(buf);
2831 sfree(c);
2832 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2833 PKT_INT, GET_32BIT(pktin.body),
2834 PKT_END);
2835 } else {
2836 c->remoteid = GET_32BIT(pktin.body);
2837 c->localid = alloc_channel_id();
2838 c->closes = 0;
5471d09a 2839 c->v.v1.throttling = 0;
d74d141c 2840 c->type = CHAN_SOCKDATA; /* identify channel type */
2841 add234(ssh_channels, c);
2842 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2843 PKT_INT, c->remoteid, PKT_INT,
2844 c->localid, PKT_END);
2845 logevent("Forwarded port opened successfully");
2846 }
2847 }
2848
2849 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
bc240b21 2850 unsigned int remoteid = GET_32BIT(pktin.body);
2851 unsigned int localid = GET_32BIT(pktin.body+4);
2852 struct ssh_channel *c;
2853
2854 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2855 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2856 c->remoteid = localid;
2857 c->type = CHAN_SOCKDATA;
2858 pfd_confirm(c->u.pfd.s);
2859 }
d74d141c 2860
724cface 2861 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
2862 unsigned int remoteid = GET_32BIT(pktin.body);
2863 unsigned int localid = GET_32BIT(pktin.body+4);
2864 struct ssh_channel *c;
2865
2866 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2867 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2868 logevent("Forwarded connection refused by server");
2869 pfd_close(c->u.pfd.s);
2870 del234(ssh_channels, c);
2871 sfree(c);
2872 }
2873
db7d555c 2874 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2875 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 2876 /* Remote side closes a channel. */
2877 unsigned i = GET_32BIT(pktin.body);
2878 struct ssh_channel *c;
2879 c = find234(ssh_channels, &i, ssh_channelfind);
2880 if (c) {
2881 int closetype;
2882 closetype =
2883 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2884 if (!(c->closes & closetype))
2885 send_packet(pktin.type, PKT_INT, c->remoteid,
2886 PKT_END);
783415f8 2887 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 2888 logevent("Forwarded X11 connection terminated");
9c964e85 2889 assert(c->u.x11.s != NULL);
2890 x11_close(c->u.x11.s);
2891 c->u.x11.s = NULL;
2892 }
d74d141c 2893 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
2894 logevent("Forwarded port closed");
2895 assert(c->u.pfd.s != NULL);
2896 pfd_close(c->u.pfd.s);
2897 c->u.pfd.s = NULL;
2898 }
32874aea 2899 c->closes |= closetype;
2900 if (c->closes == 3) {
2901 del234(ssh_channels, c);
2902 sfree(c);
2903 }
2904 }
2905 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2906 /* Data sent down one of our channels. */
2907 int i = GET_32BIT(pktin.body);
2908 int len = GET_32BIT(pktin.body + 4);
2909 unsigned char *p = pktin.body + 8;
2910 struct ssh_channel *c;
2911 c = find234(ssh_channels, &i, ssh_channelfind);
2912 if (c) {
5471d09a 2913 int bufsize;
32874aea 2914 switch (c->type) {
2915 case CHAN_X11:
5471d09a 2916 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 2917 break;
d74d141c 2918 case CHAN_SOCKDATA:
5471d09a 2919 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 2920 break;
32874aea 2921 case CHAN_AGENT:
2922 /* Data for an agent message. Buffer it. */
2923 while (len > 0) {
2924 if (c->u.a.lensofar < 4) {
2925 int l = min(4 - c->u.a.lensofar, len);
2926 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2927 l);
2928 p += l;
2929 len -= l;
2930 c->u.a.lensofar += l;
2931 }
2932 if (c->u.a.lensofar == 4) {
2933 c->u.a.totallen =
2934 4 + GET_32BIT(c->u.a.msglen);
2935 c->u.a.message = smalloc(c->u.a.totallen);
2936 memcpy(c->u.a.message, c->u.a.msglen, 4);
2937 }
2938 if (c->u.a.lensofar >= 4 && len > 0) {
2939 int l =
2940 min(c->u.a.totallen - c->u.a.lensofar,
2941 len);
2942 memcpy(c->u.a.message + c->u.a.lensofar, p,
2943 l);
2944 p += l;
2945 len -= l;
2946 c->u.a.lensofar += l;
2947 }
2948 if (c->u.a.lensofar == c->u.a.totallen) {
2949 void *reply, *sentreply;
2950 int replylen;
2951 agent_query(c->u.a.message,
2952 c->u.a.totallen, &reply,
2953 &replylen);
2954 if (reply)
2955 sentreply = reply;
2956 else {
2957 /* Fake SSH_AGENT_FAILURE. */
2958 sentreply = "\0\0\0\1\5";
2959 replylen = 5;
2960 }
2961 send_packet(SSH1_MSG_CHANNEL_DATA,
2962 PKT_INT, c->remoteid,
2963 PKT_INT, replylen,
2964 PKT_DATA, sentreply, replylen,
2965 PKT_END);
2966 if (reply)
2967 sfree(reply);
2968 sfree(c->u.a.message);
2969 c->u.a.lensofar = 0;
2970 }
2971 }
5471d09a 2972 bufsize = 0; /* agent channels never back up */
32874aea 2973 break;
2974 }
90347b95 2975 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 2976 c->v.v1.throttling = 1;
2977 ssh1_throttle(+1);
2978 }
32874aea 2979 }
e5574168 2980 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2981 /* may be from EXEC_SHELL on some servers */
e5574168 2982 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2983 /* may be from EXEC_SHELL on some servers
374330e2 2984 * if no pty is available or in other odd cases. Ignore */
e5574168 2985 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2986 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2987 } else {
8d5de777 2988 bombout(("Strange packet received: type %d", pktin.type));
32874aea 2989 crReturnV;
374330e2 2990 }
2991 } else {
8df7a775 2992 while (inlen > 0) {
2993 int len = min(inlen, 512);
2994 send_packet(SSH1_CMSG_STDIN_DATA,
2995 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2996 in += len;
2997 inlen -= len;
2998 }
374330e2 2999 }
3000 }
3001
3002 crFinishV;
3003}
3004
3005/*
e5574168 3006 * Utility routine for decoding comma-separated strings in KEXINIT.
3007 */
32874aea 3008static int in_commasep_string(char *needle, char *haystack, int haylen)
3009{
e5574168 3010 int needlen = strlen(needle);
3011 while (1) {
32874aea 3012 /*
3013 * Is it at the start of the string?
3014 */
3015 if (haylen >= needlen && /* haystack is long enough */
3016 !memcmp(needle, haystack, needlen) && /* initial match */
3017 (haylen == needlen || haystack[needlen] == ',')
3018 /* either , or EOS follows */
3019 )
3020 return 1;
3021 /*
3022 * If not, search for the next comma and resume after that.
3023 * If no comma found, terminate.
3024 */
3025 while (haylen > 0 && *haystack != ',')
3026 haylen--, haystack++;
3027 if (haylen == 0)
3028 return 0;
3029 haylen--, haystack++; /* skip over comma itself */
e5574168 3030 }
3031}
3032
3033/*
d39f364a 3034 * SSH2 key creation method.
3035 */
32874aea 3036static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3037 char *keyspace)
3038{
d39f364a 3039 SHA_State s;
3040 /* First 20 bytes. */
3041 SHA_Init(&s);
3042 sha_mpint(&s, K);
3043 SHA_Bytes(&s, H, 20);
3044 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3045 SHA_Bytes(&s, sessid, 20);
d39f364a 3046 SHA_Final(&s, keyspace);
3047 /* Next 20 bytes. */
3048 SHA_Init(&s);
3049 sha_mpint(&s, K);
3050 SHA_Bytes(&s, H, 20);
3051 SHA_Bytes(&s, keyspace, 20);
32874aea 3052 SHA_Final(&s, keyspace + 20);
d39f364a 3053}
3054
3055/*
7cca0d81 3056 * Handle the SSH2 transport layer.
e5574168 3057 */
7cca0d81 3058static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 3059{
ca20bfcf 3060 static int i, j, len, nbits, pbits, warn;
e5574168 3061 static char *str;
a92dd380 3062 static Bignum p, g, e, f, K;
3063 static int kex_init_value, kex_reply_value;
7591b9ff 3064 static const struct ssh_mac **maclist;
8b2715b2 3065 static int nmacs;
0a3f1d48 3066 static const struct ssh2_cipher *cscipher_tobe = NULL;
3067 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 3068 static const struct ssh_mac *csmac_tobe = NULL;
3069 static const struct ssh_mac *scmac_tobe = NULL;
3070 static const struct ssh_compress *cscomp_tobe = NULL;
3071 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 3072 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 3073 static int hostkeylen, siglen;
e055a386 3074 static void *hkey; /* actual host key */
e5574168 3075 static unsigned char exchange_hash[20];
d39f364a 3076 static unsigned char keyspace[40];
ca20bfcf 3077 static int n_preferred_ciphers;
3078 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4ba9b64b 3079 static const struct ssh_compress *preferred_comp;
0db56f73 3080 static int first_kex;
e5574168 3081
3082 crBegin;
7cca0d81 3083 random_init();
0db56f73 3084 first_kex = 1;
e5574168 3085
5e8358ad 3086 /*
ca20bfcf 3087 * Set up the preferred ciphers. (NULL => warn below here)
5e8358ad 3088 */
ca20bfcf 3089 n_preferred_ciphers = 0;
3090 for (i = 0; i < CIPHER_MAX; i++) {
3091 switch (cfg.ssh_cipherlist[i]) {
3092 case CIPHER_BLOWFISH:
3093 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3094 n_preferred_ciphers++;
3095 break;
3096 case CIPHER_DES:
3097 /* Not supported in SSH2; silently drop */
3098 break;
3099 case CIPHER_3DES:
3100 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3101 n_preferred_ciphers++;
3102 break;
3103 case CIPHER_AES:
3104 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3105 n_preferred_ciphers++;
3106 break;
3107 case CIPHER_WARN:
3108 /* Flag for later. Don't bother if it's the last in
3109 * the list. */
3110 if (i < CIPHER_MAX - 1) {
3111 preferred_ciphers[n_preferred_ciphers] = NULL;
3112 n_preferred_ciphers++;
3113 }
3114 break;
3115 }
5e8358ad 3116 }
ca20bfcf 3117
3118 /*
3119 * Set up preferred compression.
3120 */
4ba9b64b 3121 if (cfg.compression)
3122 preferred_comp = &ssh_zlib;
3123 else
3124 preferred_comp = &ssh_comp_none;
5e8358ad 3125
7591b9ff 3126 /*
3127 * Be prepared to work around the buggy MAC problem.
3128 */
7d503c31 3129 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
32874aea 3130 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 3131 else
32874aea 3132 maclist = macs, nmacs = lenof(macs);
7591b9ff 3133
32874aea 3134 begin_key_exchange:
e5574168 3135 /*
3136 * Construct and send our key exchange packet.
3137 */
3138 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3139 for (i = 0; i < 16; i++)
32874aea 3140 ssh2_pkt_addbyte((unsigned char) random_byte());
e5574168 3141 /* List key exchange algorithms. */
3142 ssh2_pkt_addstring_start();
3143 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3144 ssh2_pkt_addstring_str(kex_algs[i]->name);
3145 if (i < lenof(kex_algs) - 1)
3146 ssh2_pkt_addstring_str(",");
e5574168 3147 }
3148 /* List server host key algorithms. */
3149 ssh2_pkt_addstring_start();
3150 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3151 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3152 if (i < lenof(hostkey_algs) - 1)
3153 ssh2_pkt_addstring_str(",");
e5574168 3154 }
3155 /* List client->server encryption algorithms. */
3156 ssh2_pkt_addstring_start();
ca20bfcf 3157 for (i = 0; i < n_preferred_ciphers; i++) {
3158 const struct ssh2_ciphers *c = preferred_ciphers[i];
3159 if (!c) continue; /* warning flag */
32874aea 3160 for (j = 0; j < c->nciphers; j++) {
3161 ssh2_pkt_addstring_str(c->list[j]->name);
ca20bfcf 3162 if (i < n_preferred_ciphers || j < c->nciphers - 1)
32874aea 3163 ssh2_pkt_addstring_str(",");
3164 }
e5574168 3165 }
3166 /* List server->client encryption algorithms. */
3167 ssh2_pkt_addstring_start();
ca20bfcf 3168 for (i = 0; i < n_preferred_ciphers; i++) {
3169 const struct ssh2_ciphers *c = preferred_ciphers[i];
3170 if (!c) continue; /* warning flag */
32874aea 3171 for (j = 0; j < c->nciphers; j++) {
3172 ssh2_pkt_addstring_str(c->list[j]->name);
ca20bfcf 3173 if (i < n_preferred_ciphers || j < c->nciphers - 1)
32874aea 3174 ssh2_pkt_addstring_str(",");
3175 }
e5574168 3176 }
3177 /* List client->server MAC algorithms. */
3178 ssh2_pkt_addstring_start();
8b2715b2 3179 for (i = 0; i < nmacs; i++) {
32874aea 3180 ssh2_pkt_addstring_str(maclist[i]->name);
3181 if (i < nmacs - 1)
3182 ssh2_pkt_addstring_str(",");
e5574168 3183 }
3184 /* List server->client MAC algorithms. */
3185 ssh2_pkt_addstring_start();
8b2715b2 3186 for (i = 0; i < nmacs; i++) {
32874aea 3187 ssh2_pkt_addstring_str(maclist[i]->name);
3188 if (i < nmacs - 1)
3189 ssh2_pkt_addstring_str(",");
e5574168 3190 }
3191 /* List client->server compression algorithms. */
3192 ssh2_pkt_addstring_start();
32874aea 3193 for (i = 0; i < lenof(compressions) + 1; i++) {
3194 const struct ssh_compress *c =
3195 i == 0 ? preferred_comp : compressions[i - 1];
3196 ssh2_pkt_addstring_str(c->name);
3197 if (i < lenof(compressions))
3198 ssh2_pkt_addstring_str(",");
e5574168 3199 }
3200 /* List server->client compression algorithms. */
3201 ssh2_pkt_addstring_start();
32874aea 3202 for (i = 0; i < lenof(compressions) + 1; i++) {
3203 const struct ssh_compress *c =
3204 i == 0 ? preferred_comp : compressions[i - 1];
3205 ssh2_pkt_addstring_str(c->name);
3206 if (i < lenof(compressions))
3207 ssh2_pkt_addstring_str(",");
e5574168 3208 }
3209 /* List client->server languages. Empty list. */
3210 ssh2_pkt_addstring_start();
3211 /* List server->client languages. Empty list. */
3212 ssh2_pkt_addstring_start();
3213 /* First KEX packet does _not_ follow, because we're not that brave. */
3214 ssh2_pkt_addbool(FALSE);
3215 /* Reserved. */
3216 ssh2_pkt_adduint32(0);
0db56f73 3217
3218 exhash = exhashbase;
32874aea 3219 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
0db56f73 3220
e5574168 3221 ssh2_pkt_send();
3222
32874aea 3223 if (!ispkt)
3224 crWaitUntil(ispkt);
3225 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
e5574168 3226
3227 /*
3228 * Now examine the other side's KEXINIT to see what we're up
3229 * to.
3230 */
7cca0d81 3231 if (pktin.type != SSH2_MSG_KEXINIT) {
32874aea 3232 bombout(("expected key exchange packet from server"));
3233 crReturn(0);
7cca0d81 3234 }
32874aea 3235 kex = NULL;
3236 hostkey = NULL;
3237 cscipher_tobe = NULL;
3238 sccipher_tobe = NULL;
3239 csmac_tobe = NULL;
3240 scmac_tobe = NULL;
3241 cscomp_tobe = NULL;
3242 sccomp_tobe = NULL;
3243 pktin.savedpos += 16; /* skip garbage cookie */
e5574168 3244 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3245 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3246 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3247 kex = kex_algs[i];
3248 break;
3249 }
e5574168 3250 }
3251 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3252 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3253 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3254 hostkey = hostkey_algs[i];
3255 break;
3256 }
e5574168 3257 }
3258 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
ca20bfcf 3259 warn = 0;
3260 for (i = 0; i < n_preferred_ciphers; i++) {
3261 const struct ssh2_ciphers *c = preferred_ciphers[i];
3262 if (!c) {
3263 warn = 1;
3264 } else {
3265 for (j = 0; j < c->nciphers; j++) {
3266 if (in_commasep_string(c->list[j]->name, str, len)) {
3267 cscipher_tobe = c->list[j];
3268 break;
3269 }
32874aea 3270 }
3271 }
ca20bfcf 3272 if (cscipher_tobe) {
3273 if (warn)
3274 askcipher(cscipher_tobe->name, 1);
32874aea 3275 break;
ca20bfcf 3276 }
e5574168 3277 }
3278 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
ca20bfcf 3279 warn = 0;
3280 for (i = 0; i < n_preferred_ciphers; i++) {
3281 const struct ssh2_ciphers *c = preferred_ciphers[i];
3282 if (!c) {
3283 warn = 1;
3284 } else {
3285 for (j = 0; j < c->nciphers; j++) {
3286 if (in_commasep_string(c->list[j]->name, str, len)) {
3287 sccipher_tobe = c->list[j];
3288 break;
3289 }
32874aea 3290 }
3291 }
ca20bfcf 3292 if (sccipher_tobe) {
3293 if (warn)
3294 askcipher(sccipher_tobe->name, 2);
32874aea 3295 break;
ca20bfcf 3296 }
e5574168 3297 }
3298 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 3299 for (i = 0; i < nmacs; i++) {
32874aea 3300 if (in_commasep_string(maclist[i]->name, str, len)) {
3301 csmac_tobe = maclist[i];
3302 break;
3303 }
e5574168 3304 }
3305 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 3306 for (i = 0; i < nmacs; i++) {
32874aea 3307 if (in_commasep_string(maclist[i]->name, str, len)) {
3308 scmac_tobe = maclist[i];
3309 break;
3310 }
e5574168 3311 }
3312 ssh2_pkt_getstring(&str, &len); /* client->server compression */
32874aea 3313 for (i = 0; i < lenof(compressions) + 1; i++) {
3314 const struct ssh_compress *c =
3315 i == 0 ? preferred_comp : compressions[i - 1];
3316 if (in_commasep_string(c->name, str, len)) {
3317 cscomp_tobe = c;
3318 break;
3319 }
e5574168 3320 }
3321 ssh2_pkt_getstring(&str, &len); /* server->client compression */
32874aea 3322 for (i = 0; i < lenof(compressions) + 1; i++) {
3323 const struct ssh_compress *c =
3324 i == 0 ? preferred_comp : compressions[i - 1];
3325 if (in_commasep_string(c->name, str, len)) {
3326 sccomp_tobe = c;
3327 break;
3328 }
e5574168 3329 }
e5574168 3330
3331 /*
7bd5a860 3332 * Work out the number of bits of key we will need from the key
3333 * exchange. We start with the maximum key length of either
3334 * cipher...
3335 */
3336 {
32874aea 3337 int csbits, scbits;
7bd5a860 3338
3339 csbits = cscipher_tobe->keylen;
3340 scbits = sccipher_tobe->keylen;
3341 nbits = (csbits > scbits ? csbits : scbits);
3342 }
3343 /* The keys only have 160-bit entropy, since they're based on
3344 * a SHA-1 hash. So cap the key size at 160 bits. */
32874aea 3345 if (nbits > 160)
3346 nbits = 160;
7bd5a860 3347
3348 /*
a92dd380 3349 * If we're doing Diffie-Hellman group exchange, start by
3350 * requesting a group.
e5574168 3351 */
a92dd380 3352 if (kex == &ssh_diffiehellman_gex) {
32874aea 3353 logevent("Doing Diffie-Hellman group exchange");
3354 /*
3355 * Work out how big a DH group we will need to allow that
3356 * much data.
7bd5a860 3357 */
32874aea 3358 pbits = 512 << ((nbits - 1) / 64);
3359 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3360 ssh2_pkt_adduint32(pbits);
3361 ssh2_pkt_send();
3362
3363 crWaitUntil(ispkt);
3364 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3365 bombout(("expected key exchange group packet from server"));
3366 crReturn(0);
3367 }
3368 p = ssh2_pkt_getmp();
3369 g = ssh2_pkt_getmp();
3370 dh_setup_group(p, g);
3371 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3372 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3373 } else {
32874aea 3374 dh_setup_group1();
3375 kex_init_value = SSH2_MSG_KEXDH_INIT;
3376 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3377 }
e5574168 3378
a92dd380 3379 logevent("Doing Diffie-Hellman key exchange");
e5574168 3380 /*
a92dd380 3381 * Now generate and send e for Diffie-Hellman.
e5574168 3382 */
32874aea 3383 e = dh_create_e(nbits * 2);
a92dd380 3384 ssh2_pkt_init(kex_init_value);
e5574168 3385 ssh2_pkt_addmp(e);
3386 ssh2_pkt_send();
3387
3388 crWaitUntil(ispkt);
a92dd380 3389 if (pktin.type != kex_reply_value) {
32874aea 3390 bombout(("expected key exchange reply packet from server"));
3391 crReturn(0);
7cca0d81 3392 }
e5574168 3393 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3394 f = ssh2_pkt_getmp();
e5574168 3395 ssh2_pkt_getstring(&sigdata, &siglen);
3396
3397 K = dh_find_K(f);
e5574168 3398
3399 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 3400 if (kex == &ssh_diffiehellman_gex) {
32874aea 3401 sha_uint32(&exhash, pbits);
3402 sha_mpint(&exhash, p);
3403 sha_mpint(&exhash, g);
a92dd380 3404 }
e5574168 3405 sha_mpint(&exhash, e);
3406 sha_mpint(&exhash, f);
3407 sha_mpint(&exhash, K);
3408 SHA_Final(&exhash, exchange_hash);
3409
3709bfe9 3410 dh_cleanup();
3411
7cca0d81 3412#if 0
765c4200 3413 debug(("Exchange hash is:\n"));
3414 dmemdump(exchange_hash, 20);
7cca0d81 3415#endif
3416
e055a386 3417 hkey = hostkey->newkey(hostkeydata, hostkeylen);
f7259d10 3418 if (!hkey ||
3419 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3420 bombout(("Server's host key did not match the signature supplied"));
32874aea 3421 crReturn(0);
8d5de777 3422 }
e5574168 3423
3424 /*
7cca0d81 3425 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 3426 */
7cca0d81 3427 crWaitUntil(ispkt);
8d5de777 3428 if (pktin.type != SSH2_MSG_NEWKEYS) {
32874aea 3429 bombout(("expected new-keys packet from server"));
3430 crReturn(0);
8d5de777 3431 }
d39f364a 3432
3433 /*
7cca0d81 3434 * Authenticate remote host: verify host key. (We've already
3435 * checked the signature of the exchange hash.)
e5574168 3436 */
e055a386 3437 keystr = hostkey->fmtkey(hkey);
3438 fingerprint = hostkey->fingerprint(hkey);
d4857987 3439 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
32874aea 3440 keystr, fingerprint);
3441 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 3442 logevent("Host key fingerprint is:");
3443 logevent(fingerprint);
3444 }
dcbde236 3445 sfree(fingerprint);
3446 sfree(keystr);
e055a386 3447 hostkey->freekey(hkey);
d39f364a 3448
3449 /*
7cca0d81 3450 * Send SSH2_MSG_NEWKEYS.
d39f364a 3451 */
3452 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3453 ssh2_pkt_send();
d39f364a 3454
3455 /*
3456 * Create and initialise session keys.
3457 */
3458 cscipher = cscipher_tobe;
3459 sccipher = sccipher_tobe;
3460 csmac = csmac_tobe;
3461 scmac = scmac_tobe;
3462 cscomp = cscomp_tobe;
3463 sccomp = sccomp_tobe;
4ba9b64b 3464 cscomp->compress_init();
3465 sccomp->decompress_init();
d39f364a 3466 /*
5e0d7cb8 3467 * Set IVs after keys. Here we use the exchange hash from the
3468 * _first_ key exchange.
d39f364a 3469 */
5e0d7cb8 3470 if (first_kex)
65a22376 3471 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3472 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 3473 cscipher->setcskey(keyspace);
65a22376 3474 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 3475 sccipher->setsckey(keyspace);
65a22376 3476 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 3477 cscipher->setcsiv(keyspace);
65a22376 3478 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 3479 sccipher->setsciv(keyspace);
65a22376 3480 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 3481 csmac->setcskey(keyspace);
65a22376 3482 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 3483 scmac->setsckey(keyspace);
d39f364a 3484
033b4cef 3485 /*
0db56f73 3486 * If this is the first key exchange phase, we must pass the
3487 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3488 * wants to see it but because it will need time to initialise
3489 * itself before it sees an actual packet. In subsequent key
3490 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3491 * it would only confuse the layer above.
3492 */
3493 if (!first_kex) {
32874aea 3494 crReturn(0);
0db56f73 3495 }
3496 first_kex = 0;
3497
3498 /*
7cca0d81 3499 * Now we're encrypting. Begin returning 1 to the protocol main
3500 * function so that other things can run on top of the
3501 * transport. If we ever see a KEXINIT, we must go back to the
3502 * start.
033b4cef 3503 */
e96adf72 3504 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 3505 crReturn(1);
e96adf72 3506 }
5e0d7cb8 3507 logevent("Server initiated key re-exchange");
7cca0d81 3508 goto begin_key_exchange;
e5574168 3509
3510 crFinish(1);
3511}
3512
7cca0d81 3513/*
783415f8 3514 * Add data to an SSH2 channel output buffer.
3515 */
32874aea 3516static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3517 int len)
3518{
5471d09a 3519 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 3520}
3521
3522/*
3523 * Attempt to send data on an SSH2 channel.
3524 */
5471d09a 3525static int ssh2_try_send(struct ssh_channel *c)
32874aea 3526{
5471d09a 3527 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3528 int len;
3529 void *data;
3530 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3531 if ((unsigned)len > c->v.v2.remwindow)
3532 len = c->v.v2.remwindow;
3533 if ((unsigned)len > c->v.v2.remmaxpkt)
3534 len = c->v.v2.remmaxpkt;
32874aea 3535 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3536 ssh2_pkt_adduint32(c->remoteid);
3537 ssh2_pkt_addstring_start();
5471d09a 3538 ssh2_pkt_addstring_data(data, len);
32874aea 3539 ssh2_pkt_send();
5471d09a 3540 bufchain_consume(&c->v.v2.outbuffer, len);
3541 c->v.v2.remwindow -= len;
3542 }
3543
3544 /*
3545 * After having sent as much data as we can, return the amount
3546 * still buffered.
3547 */
3548 return bufchain_size(&c->v.v2.outbuffer);
3549}
3550
3551/*
3552 * Potentially enlarge the window on an SSH2 channel.
3553 */
3554static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3555{
3556 if (newwin > c->v.v2.locwindow) {
3557 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3558 ssh2_pkt_adduint32(c->remoteid);
3559 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
3560 ssh2_pkt_send();
3561 c->v.v2.locwindow = newwin;
783415f8 3562 }
3563}
3564
3565/*
7cca0d81 3566 * Handle the SSH2 userauth and connection layers.
3567 */
3568static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3569{
65a22376 3570 static enum {
32874aea 3571 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
761187b6 3572 AUTH_PASSWORD,
3573 AUTH_KEYBOARD_INTERACTIVE
65a22376 3574 } method;
1408a877 3575 static enum {
32874aea 3576 AUTH_TYPE_NONE,
3577 AUTH_TYPE_PUBLICKEY,
3578 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3579 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
761187b6 3580 AUTH_TYPE_PASSWORD,
4bdf7c46 3581 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3582 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
1408a877 3583 } type;
761187b6 3584 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3585 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
b3186d64 3586 static int kbd_inter_running;
1408a877 3587 static int we_are_in;
761187b6 3588 static int num_prompts, echo;
65a22376 3589 static char username[100];
3590 static char pwprompt[200];
3591 static char password[100];
7cca0d81 3592
e5574168 3593 crBegin;
3594
7cca0d81 3595 /*
3596 * Request userauth protocol, and await a response to it.
3597 */
3598 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3599 ssh2_pkt_addstring("ssh-userauth");
3600 ssh2_pkt_send();
3601 crWaitUntilV(ispkt);
8d5de777 3602 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 3603 bombout(("Server refused user authentication protocol"));
3604 crReturnV;
8d5de777 3605 }
7cca0d81 3606
3607 /*
1408a877 3608 * We repeat this whole loop, including the username prompt,
3609 * until we manage a successful authentication. If the user
3610 * types the wrong _password_, they are sent back to the
3611 * beginning to try another username. (If they specify a
3612 * username in the config, they are never asked, even if they
3613 * do give a wrong password.)
3614 *
3615 * I think this best serves the needs of
3616 *
3617 * - the people who have no configuration, no keys, and just
3618 * want to try repeated (username,password) pairs until they
3619 * type both correctly
3620 *
3621 * - people who have keys and configuration but occasionally
3622 * need to fall back to passwords
3623 *
3624 * - people with a key held in Pageant, who might not have
3625 * logged in to a particular machine before; so they want to
3626 * type a username, and then _either_ their key will be
3627 * accepted, _or_ they will type a password. If they mistype
3628 * the username they will want to be able to get back and
3629 * retype it!
7cca0d81 3630 */
1408a877 3631 do {
3632 static int pos;
7cca0d81 3633 static char c;
e5574168 3634
1408a877 3635 /*
3636 * Get a username.
3637 */
3638 pos = 0;
67779be7 3639 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 3640 if (ssh_get_line) {
3641 if (!ssh_get_line("login as: ",
3642 username, sizeof(username), FALSE)) {
3643 /*
3644 * get_line failed to get a username.
3645 * Terminate.
3646 */
3647 logevent("No username provided. Abandoning session.");
3648 ssh_state = SSH_STATE_CLOSED;
3649 crReturnV;
3650 }
3651 } else {
3652 c_write_str("login as: ");
3653 ssh_send_ok = 1;
3654 while (pos >= 0) {
3655 crWaitUntilV(!ispkt);
3656 while (inlen--)
3657 switch (c = *in++) {
3658 case 10:
3659 case 13:
3660 username[pos] = 0;
3661 pos = -1;
3662 break;
3663 case 8:
3664 case 127:
3665 if (pos > 0) {
3666 c_write_str("\b \b");
3667 pos--;
3668 }
3669 break;
3670 case 21:
3671 case 27:
3672 while (pos > 0) {
3673 c_write_str("\b \b");
3674 pos--;
3675 }
3676 break;
3677 case 3:
3678 case 4:
3679 random_save_seed();
3680 exit(0);
3681 break;
3682 default:
3683 if (((c >= ' ' && c <= '~') ||
51b2fb65 3684 ((unsigned char) c >= 160))
3685 && pos < sizeof(username)-1) {
32874aea 3686 username[pos++] = c;
3687 c_write(&c, 1);
3688 }
3689 break;
3690 }
3691 }
3692 }
1408a877 3693 c_write_str("\r\n");
7cca0d81 3694 username[strcspn(username, "\n\r")] = '\0';
3695 } else {
3696 char stuff[200];
3697 strncpy(username, cfg.username, 99);
3698 username[99] = '\0';
65a22376 3699 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 3700 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 3701 c_write_str(stuff);
7cca0d81 3702 }
3703 }
3704
65a22376 3705 /*
1408a877 3706 * Send an authentication request using method "none": (a)
3707 * just in case it succeeds, and (b) so that we know what
3708 * authentication methods we can usefully try next.
65a22376 3709 */
1408a877 3710 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3711 ssh2_pkt_addstring(username);
32874aea 3712 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3713 ssh2_pkt_addstring("none"); /* method */
3714 ssh2_pkt_send();
3715 type = AUTH_TYPE_NONE;
3716 gotit = FALSE;
3717 we_are_in = FALSE;
7cca0d81 3718
1408a877 3719 tried_pubkey_config = FALSE;
1983e559 3720 tried_agent = FALSE;
b3186d64 3721 tried_keyb_inter = FALSE;
3722 kbd_inter_running = FALSE;
65a22376 3723
1408a877 3724 while (1) {
3725 /*
3726 * Wait for the result of the last authentication request.
3727 */
3728 if (!gotit)
3729 crWaitUntilV(ispkt);
3730 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 3731 char *banner;
3732 int size;
3733 /*
3734 * Don't show the banner if we're operating in
3735 * non-verbose non-interactive mode. (It's probably
3736 * a script, which means nobody will read the
3737 * banner _anyway_, and moreover the printing of
3738 * the banner will screw up processing on the
3739 * output of (say) plink.)
3740 */
3741 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3742 ssh2_pkt_getstring(&banner, &size);
3743 if (banner)
3744 c_write_untrusted(banner, size);
3745 }
1408a877 3746 crWaitUntilV(ispkt);
3747 }
3748 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3749 logevent("Access granted");
3750 we_are_in = TRUE;
3751 break;
3752 }
65a22376 3753
b3186d64 3754 if (kbd_inter_running &&
3755 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
3756 /*
3757 * This is a further prompt in keyboard-interactive
3758 * authentication. Do nothing.
3759 */
6bb26b30 3760 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
b3186d64 3761 bombout(("Strange packet received during authentication: type %d",
1408a877 3762 pktin.type));
38c4a8da 3763 crReturnV;
65a22376 3764 }
3765
1408a877 3766 gotit = FALSE;
65a22376 3767
1408a877 3768 /*
3769 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3770 * we can look at the string in it and know what we can
3771 * helpfully try next.
3772 */
b3186d64 3773 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 3774 char *methods;
3775 int methlen;
3776 ssh2_pkt_getstring(&methods, &methlen);
b3186d64 3777 kbd_inter_running = FALSE;
1408a877 3778 if (!ssh2_pkt_getbool()) {
3779 /*
3780 * We have received an unequivocal Access
3781 * Denied. This can translate to a variety of
3782 * messages:
3783 *
3784 * - if we'd just tried "none" authentication,
3785 * it's not worth printing anything at all
3786 *
3787 * - if we'd just tried a public key _offer_,
3788 * the message should be "Server refused our
3789 * key" (or no message at all if the key
3790 * came from Pageant)
3791 *
3792 * - if we'd just tried anything else, the
3793 * message really should be "Access denied".
3794 *
3795 * Additionally, if we'd just tried password
3796 * authentication, we should break out of this
3797 * whole loop so as to go back to the username
3798 * prompt.
3799 */
3800 if (type == AUTH_TYPE_NONE) {
3801 /* do nothing */
3802 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3803 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3804 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3805 c_write_str("Server refused our key\r\n");
3806 logevent("Server refused public key");
4bdf7c46 3807 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
3808 /* server declined keyboard-interactive; ignore */
1408a877 3809 } else {
3810 c_write_str("Access denied\r\n");
3811 logevent("Access denied");
3812 if (type == AUTH_TYPE_PASSWORD) {
3813 we_are_in = FALSE;
3814 break;
3815 }
3816 }
3817 } else {
3818 c_write_str("Further authentication required\r\n");
3819 logevent("Further authentication required");
3820 }
65a22376 3821
32874aea 3822 can_pubkey =
3823 in_commasep_string("publickey", methods, methlen);
3824 can_passwd =
3825 in_commasep_string("password", methods, methlen);
761187b6 3826 can_keyb_inter =
3827 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 3828 }
65a22376 3829
1408a877 3830 method = 0;
65a22376 3831
78afa559 3832 if (!method && can_pubkey && agent_exists() && !tried_agent) {
1983e559 3833 /*
3834 * Attempt public-key authentication using Pageant.
3835 */
3836 static unsigned char request[5], *response, *p;
3837 static int responselen;
3838 static int i, nkeys;
3839 static int authed = FALSE;
3840 void *r;
3841
3842 tried_agent = TRUE;
3843
3844 logevent("Pageant is running. Requesting keys.");
3845
3846 /* Request the keys held by the agent. */
3847 PUT_32BIT(request, 1);
3848 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3849 agent_query(request, 5, &r, &responselen);
32874aea 3850 response = (unsigned char *) r;
95797139 3851 if (response && responselen >= 5 &&
32874aea 3852 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 3853 p = response + 5;
32874aea 3854 nkeys = GET_32BIT(p);
3855 p += 4;
3856 {
3857 char buf[64];
3858 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3859 logevent(buf);
3860 }
1983e559 3861 for (i = 0; i < nkeys; i++) {
3862 static char *pkblob, *alg, *commentp;
3863 static int pklen, alglen, commentlen;
3864 static int siglen, retlen, len;
3865 static char *q, *agentreq, *ret;
2d466ffd 3866 void *vret;
1983e559 3867
32874aea 3868 {
3869 char buf[64];
3870 sprintf(buf, "Trying Pageant key #%d", i);
3871 logevent(buf);
3872 }
3873 pklen = GET_32BIT(p);
3874 p += 4;
3875 pkblob = p;
3876 p += pklen;
1983e559 3877 alglen = GET_32BIT(pkblob);
3878 alg = pkblob + 4;
32874aea 3879 commentlen = GET_32BIT(p);
3880 p += 4;
3881 commentp = p;
3882 p += commentlen;
1983e559 3883 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3884 ssh2_pkt_addstring(username);
32874aea 3885 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3886 ssh2_pkt_addstring("publickey"); /* method */
3887 ssh2_pkt_addbool(FALSE); /* no signature included */
1983e559 3888 ssh2_pkt_addstring_start();
3889 ssh2_pkt_addstring_data(alg, alglen);
3890 ssh2_pkt_addstring_start();
3891 ssh2_pkt_addstring_data(pkblob, pklen);
3892 ssh2_pkt_send();
3893
3894 crWaitUntilV(ispkt);
3895 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3896 logevent("Key refused");
3897 continue;
3898 }
3899
32874aea 3900 if (flags & FLAG_VERBOSE) {
3901 c_write_str
3902 ("Authenticating with public key \"");
3903 c_write(commentp, commentlen);
3904 c_write_str("\" from agent\r\n");
3905 }
1983e559 3906
3907 /*
3908 * Server is willing to accept the key.
3909 * Construct a SIGN_REQUEST.
3910 */
3911 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3912 ssh2_pkt_addstring(username);
32874aea 3913 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3914 ssh2_pkt_addstring("publickey"); /* method */
1983e559 3915 ssh2_pkt_addbool(TRUE);
3916 ssh2_pkt_addstring_start();
3917 ssh2_pkt_addstring_data(alg, alglen);
3918 ssh2_pkt_addstring_start();
3919 ssh2_pkt_addstring_data(pkblob, pklen);
3920
3921 siglen = pktout.length - 5 + 4 + 20;
32874aea 3922 len = 1; /* message type */
3923 len += 4 + pklen; /* key blob */
3924 len += 4 + siglen; /* data to sign */
3925 len += 4; /* flags */
1983e559 3926 agentreq = smalloc(4 + len);
3927 PUT_32BIT(agentreq, len);
3928 q = agentreq + 4;
3929 *q++ = SSH2_AGENTC_SIGN_REQUEST;
32874aea 3930 PUT_32BIT(q, pklen);
3931 q += 4;
3932 memcpy(q, pkblob, pklen);
3933 q += pklen;
3934 PUT_32BIT(q, siglen);
3935 q += 4;
1983e559 3936 /* Now the data to be signed... */
32874aea 3937 PUT_32BIT(q, 20);
3938 q += 4;
3939 memcpy(q, ssh2_session_id, 20);
3940 q += 20;
3941 memcpy(q, pktout.data + 5, pktout.length - 5);
3942 q += pktout.length - 5;
1983e559 3943 /* And finally the (zero) flags word. */
3944 PUT_32BIT(q, 0);
2d466ffd 3945 agent_query(agentreq, len + 4, &vret, &retlen);
3946 ret = vret;
1983e559 3947 sfree(agentreq);
3948 if (ret) {
3949 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3950 logevent("Sending Pageant's response");
3951 ssh2_pkt_addstring_start();
32874aea 3952 ssh2_pkt_addstring_data(ret + 9,
3953 GET_32BIT(ret +
3954 5));
1983e559 3955 ssh2_pkt_send();
3956 authed = TRUE;
3957 break;
3958 } else {
32874aea 3959 logevent
3960 ("Pageant failed to answer challenge");
1983e559 3961 sfree(ret);
3962 }
3963 }
3964 }
3965 if (authed)
3966 continue;
3967 }
3968 }
3969
32874aea 3970 if (!method && can_pubkey && *cfg.keyfile
3971 && !tried_pubkey_config) {
1408a877 3972 unsigned char *pub_blob;
3973 char *algorithm, *comment;
3974 int pub_blob_len;
65a22376 3975
1408a877 3976 tried_pubkey_config = TRUE;
65a22376 3977
65a22376 3978 /*
1408a877 3979 * Try the public key supplied in the configuration.
3980 *
3981 * First, offer the public blob to see if the server is
3982 * willing to accept it.
65a22376 3983 */
1408a877 3984 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3985 &pub_blob_len);
3986 if (pub_blob) {
3987 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3988 ssh2_pkt_addstring(username);
32874aea 3989 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3990 ssh2_pkt_addstring("publickey"); /* method */
3991 ssh2_pkt_addbool(FALSE); /* no signature included */
1408a877 3992 ssh2_pkt_addstring(algorithm);
3993 ssh2_pkt_addstring_start();
3994 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3995 ssh2_pkt_send();
32874aea 3996 logevent("Offered public key"); /* FIXME */
1408a877 3997
3998 crWaitUntilV(ispkt);
3999 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4000 gotit = TRUE;
4001 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4002 continue; /* key refused; give up on it */
1408a877 4003 }
65a22376 4004
1408a877 4005 logevent("Offer of public key accepted");
65a22376 4006 /*
1408a877 4007 * Actually attempt a serious authentication using
4008 * the key.
65a22376 4009 */
1408a877 4010 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
32874aea 4011 sprintf(pwprompt,
4012 "Passphrase for key \"%.100s\": ",
4013 comment);
1408a877 4014 need_pw = TRUE;
4015 } else {
4016 need_pw = FALSE;
4017 }
4018 c_write_str("Authenticating with public key \"");
4019 c_write_str(comment);
4020 c_write_str("\"\r\n");
4021 method = AUTH_PUBLICKEY_FILE;
65a22376 4022 }
1408a877 4023 }
4024
af659722 4025 if (!method && can_keyb_inter && !tried_keyb_inter) {
4026 method = AUTH_KEYBOARD_INTERACTIVE;
4027 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4028 tried_keyb_inter = TRUE;
4029
4030 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4031 ssh2_pkt_addstring(username);
4032 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4033 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4034 ssh2_pkt_addstring(""); /* lang */
4035 ssh2_pkt_addstring("");
4036 ssh2_pkt_send();
4037
4038 crWaitUntilV(ispkt);
4039 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4040 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4041 gotit = TRUE;
4042 logevent("Keyboard-interactive authentication refused");
4043 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4044 continue;
4045 }
4046
4047 kbd_inter_running = TRUE;
4048 }
4049
4050 if (kbd_inter_running) {
4051 method = AUTH_KEYBOARD_INTERACTIVE;
4052 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4053 tried_keyb_inter = TRUE;
4054
4055 /* We've got packet with that "interactive" info
4056 dump banners, and set its prompt as ours */
4057 {
4058 char *name, *inst, *lang, *prompt;
4059 int name_len, inst_len, lang_len, prompt_len;
4060 ssh2_pkt_getstring(&name, &name_len);
4061 ssh2_pkt_getstring(&inst, &inst_len);
4062 ssh2_pkt_getstring(&lang, &lang_len);
4063 if (name_len > 0)
4064 c_write_untrusted(name, name_len);
4065 if (inst_len > 0)
4066 c_write_untrusted(inst, inst_len);
4067 num_prompts = ssh2_pkt_getuint32();
4068
4069 ssh2_pkt_getstring(&prompt, &prompt_len);
4070 strncpy(pwprompt, prompt, sizeof(pwprompt));
4071 need_pw = TRUE;
4072
4073 echo = ssh2_pkt_getbool();
4074 }
4075 }
4076
1408a877 4077 if (!method && can_passwd) {
4078 method = AUTH_PASSWORD;
32874aea 4079 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4080 savedhost);
1408a877 4081 need_pw = TRUE;
4082 }
4083
4084 if (need_pw) {
fa17a66e 4085 if (ssh_get_line) {
4086 if (!ssh_get_line(pwprompt, password,
32874aea 4087 sizeof(password), TRUE)) {
1408a877 4088 /*
fa17a66e 4089 * get_line failed to get a password (for
4090 * example because one was supplied on the
4091 * command line which has already failed to
4092 * work). Terminate.
1408a877 4093 */
2bc6a386 4094 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4095 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4096 ssh2_pkt_addstring
4097 ("No more passwords available to try");
4098 ssh2_pkt_addstring("en"); /* language tag */
4099 ssh2_pkt_send();
4100 connection_fatal("Unable to authenticate");
1408a877 4101 ssh_state = SSH_STATE_CLOSED;
4102 crReturnV;
4103 }
4104 } else {
4105 static int pos = 0;
4106 static char c;
4107
761187b6 4108 c_write_untrusted(pwprompt, strlen(pwprompt));
1408a877 4109 ssh_send_ok = 1;
4110
4111 pos = 0;
4112 while (pos >= 0) {
4113 crWaitUntilV(!ispkt);
32874aea 4114 while (inlen--)
4115 switch (c = *in++) {
4116 case 10:
4117 case 13:
4118 password[pos] = 0;
4119 pos = -1;
4120 break;
4121 case 8:
4122 case 127:
4123 if (pos > 0)
4124 pos--;
4125 break;
4126 case 21:
4127 case 27:
4128 pos = 0;
4129 break;
4130 case 3:
4131 case 4:
4132 random_save_seed();
4133 exit(0);
4134 break;
4135 default:
51b2fb65 4136 if (pos < sizeof(password)-1)
32874aea 4137 password[pos++] = c;
4138 break;
4139 }
65a22376 4140 }
1408a877 4141 c_write_str("\r\n");
65a22376 4142 }
65a22376 4143 }
65a22376 4144
1408a877 4145 if (method == AUTH_PUBLICKEY_FILE) {
4146 /*
4147 * We have our passphrase. Now try the actual authentication.
4148 */
4149 struct ssh2_userkey *key;
65a22376 4150
1408a877 4151 key = ssh2_load_userkey(cfg.keyfile, password);
4152 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4153 if (key == SSH2_WRONG_PASSPHRASE) {
4154 c_write_str("Wrong passphrase\r\n");
4155 tried_pubkey_config = FALSE;
4156 } else {
4157 c_write_str("Unable to load private key\r\n");
4158 tried_pubkey_config = TRUE;
4159 }
4160 /* Send a spurious AUTH_NONE to return to the top. */
4161 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4162 ssh2_pkt_addstring(username);
32874aea 4163 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4164 ssh2_pkt_addstring("none"); /* method */
1408a877 4165 ssh2_pkt_send();
4166 type = AUTH_TYPE_NONE;
4167 } else {
4168 unsigned char *blob, *sigdata;
4169 int blob_len, sigdata_len;
65a22376 4170
1408a877 4171 /*
4172 * We have loaded the private key and the server
4173 * has announced that it's willing to accept it.
4174 * Hallelujah. Generate a signature and send it.
4175 */
4176 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4177 ssh2_pkt_addstring(username);
32874aea 4178 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4179 ssh2_pkt_addstring("publickey"); /* method */
1408a877 4180 ssh2_pkt_addbool(TRUE);
4181 ssh2_pkt_addstring(key->alg->name);
4182 blob = key->alg->public_blob(key->data, &blob_len);
4183 ssh2_pkt_addstring_start();
4184 ssh2_pkt_addstring_data(blob, blob_len);
4185 sfree(blob);
4186
4187 /*
4188 * The data to be signed is:
4189 *
4190 * string session-id
4191 *
4192 * followed by everything so far placed in the
4193 * outgoing packet.
4194 */
4195 sigdata_len = pktout.length - 5 + 4 + 20;
4196 sigdata = smalloc(sigdata_len);
4197 PUT_32BIT(sigdata, 20);
32874aea 4198 memcpy(sigdata + 4, ssh2_session_id, 20);
4199 memcpy(sigdata + 24, pktout.data + 5,
4200 pktout.length - 5);
4201 blob =
4202 key->alg->sign(key->data, sigdata, sigdata_len,
4203 &blob_len);
1408a877 4204 ssh2_pkt_addstring_start();
4205 ssh2_pkt_addstring_data(blob, blob_len);
4206 sfree(blob);
4207 sfree(sigdata);
4208
4209 ssh2_pkt_send();
4210 type = AUTH_TYPE_PUBLICKEY;
4211 }
4212 } else if (method == AUTH_PASSWORD) {
65a22376 4213 /*
1408a877 4214 * We send the password packet lumped tightly together with
4215 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4216 * string long enough to make the total length of the two
4217 * packets constant. This should ensure that a passive
4218 * listener doing traffic analyis can't work out the length
4219 * of the password.
4220 *
4221 * For this to work, we need an assumption about the
4222 * maximum length of the password packet. I think 256 is
4223 * pretty conservative. Anyone using a password longer than
4224 * that probably doesn't have much to worry about from
4225 * people who find out how long their password is!
65a22376 4226 */
4227 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4228 ssh2_pkt_addstring(username);
32874aea 4229 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4230 ssh2_pkt_addstring("password");
4231 ssh2_pkt_addbool(FALSE);
4232 ssh2_pkt_addstring(password);
4233 ssh2_pkt_defer();
65a22376 4234 /*
1408a877 4235 * We'll include a string that's an exact multiple of the
4236 * cipher block size. If the cipher is NULL for some
4237 * reason, we don't do this trick at all because we gain
4238 * nothing by it.
65a22376 4239 */
32874aea 4240 if (cscipher) {
4241 int stringlen, i;
4242
4243 stringlen = (256 - deferred_len);
4244 stringlen += cscipher->blksize - 1;
4245 stringlen -= (stringlen % cscipher->blksize);
4246 if (cscomp) {
4247 /*
4248 * Temporarily disable actual compression,
4249 * so we can guarantee to get this string
4250 * exactly the length we want it. The
4251 * compression-disabling routine should
4252 * return an integer indicating how many
4253 * bytes we should adjust our string length
4254 * by.
4255 */
4256 stringlen -= cscomp->disable_compression();
4257 }
1408a877 4258 ssh2_pkt_init(SSH2_MSG_IGNORE);
4259 ssh2_pkt_addstring_start();
6e9e9520 4260 for (i = 0; i < stringlen; i++) {
32874aea 4261 char c = (char) random_byte();
4262 ssh2_pkt_addstring_data(&c, 1);
65a22376 4263 }
1408a877 4264 ssh2_pkt_defer();
65a22376 4265 }
39065bed 4266 ssh_pkt_defersend();
0d43337a 4267 logevent("Sent password");
1408a877 4268 type = AUTH_TYPE_PASSWORD;
761187b6 4269 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4270 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4271 ssh2_pkt_adduint32(num_prompts);
4272 ssh2_pkt_addstring(password);
4273 memset(password, 0, sizeof(password));
4274 ssh2_pkt_send();
4275 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 4276 } else {
32874aea 4277 c_write_str
4278 ("No supported authentication methods left to try!\r\n");
4279 logevent
4280 ("No supported authentications offered. Disconnecting");
1408a877 4281 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4282 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
32874aea 4283 ssh2_pkt_addstring
4284 ("No supported authentication methods available");
4285 ssh2_pkt_addstring("en"); /* language tag */
1408a877 4286 ssh2_pkt_send();
4287 ssh_state = SSH_STATE_CLOSED;
4288 crReturnV;
65a22376 4289 }
65a22376 4290 }
1408a877 4291 } while (!we_are_in);
7cca0d81 4292
4293 /*
4294 * Now we're authenticated for the connection protocol. The
4295 * connection protocol will automatically have started at this
4296 * point; there's no need to send SERVICE_REQUEST.
4297 */
4298
4299 /*
4300 * So now create a channel with a session in it.
4301 */
d2371c81 4302 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 4303 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 4304 mainchan->localid = alloc_channel_id();
7cca0d81 4305 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4306 ssh2_pkt_addstring("session");
d211621f 4307 ssh2_pkt_adduint32(mainchan->localid);
5471d09a 4308 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4309 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
32874aea 4310 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 4311 ssh2_pkt_send();
4312 crWaitUntilV(ispkt);
4313 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 4314 bombout(("Server refused to open a session"));
4315 crReturnV;
4316 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 4317 }
d211621f 4318 if (ssh2_pkt_getuint32() != mainchan->localid) {
32874aea 4319 bombout(("Server's channel confirmation cited wrong channel"));
4320 crReturnV;
7cca0d81 4321 }
d211621f 4322 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 4323 mainchan->type = CHAN_MAINSESSION;
4324 mainchan->closes = 0;
5471d09a 4325 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4326 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4327 bufchain_init(&mainchan->v.v2.outbuffer);
783415f8 4328 add234(ssh_channels, mainchan);
7cca0d81 4329 logevent("Opened channel for session");
4330
4331 /*
783415f8 4332 * Potentially enable X11 forwarding.
4333 */
4334 if (cfg.x11_forward) {
32874aea 4335 char proto[20], data[64];
4336 logevent("Requesting X11 forwarding");
4337 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4338 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4339 ssh2_pkt_adduint32(mainchan->remoteid);
4340 ssh2_pkt_addstring("x11-req");
4341 ssh2_pkt_addbool(1); /* want reply */
4342 ssh2_pkt_addbool(0); /* many connections */
4343 ssh2_pkt_addstring(proto);
4344 ssh2_pkt_addstring(data);
4345 ssh2_pkt_adduint32(0); /* screen number */
4346 ssh2_pkt_send();
4347
4348 do {
4349 crWaitUntilV(ispkt);
4350 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4351 unsigned i = ssh2_pkt_getuint32();
4352 struct ssh_channel *c;
4353 c = find234(ssh_channels, &i, ssh_channelfind);
4354 if (!c)
4355 continue; /* nonexistent channel */
5471d09a 4356 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4357 }
4358 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4359
4360 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4361 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4362 bombout(("Server got confused by X11 forwarding request"));
4363 crReturnV;
4364 }
4365 logevent("X11 forwarding refused");
4366 } else {
4367 logevent("X11 forwarding enabled");
783415f8 4368 ssh_X11_fwd_enabled = TRUE;
32874aea 4369 }
783415f8 4370 }
4371
4372 /*
bc240b21 4373 * Enable port forwardings.
4374 */
4375 {
4376 static char *e; /* preserve across crReturn */
4377 char type;
4378 int n;
4379 int sport,dport;
4380 char sports[256], dports[256], host[256];
4381 char buf[1024];
4382
4383 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4384 /* Add port forwardings. */
4385 e = cfg.portfwd;
4386 while (*e) {
4387 type = *e++;
4388 n = 0;
4389 while (*e && *e != '\t')
4390 sports[n++] = *e++;
4391 sports[n] = 0;
4392 if (*e == '\t')
4393 e++;
4394 n = 0;
4395 while (*e && *e != ':')
4396 host[n++] = *e++;
4397 host[n] = 0;
4398 if (*e == ':')
4399 e++;
4400 n = 0;
4401 while (*e)
4402 dports[n++] = *e++;
4403 dports[n] = 0;
4404 e++;
4405 dport = atoi(dports);
4406 sport = atoi(sports);
4407 if (sport && dport) {
4408 if (type == 'L') {
4409 pfd_addforward(host, dport, sport);
4410 sprintf(buf, "Local port %d forwarding to %s:%d",
4411 sport, host, dport);
4412 logevent(buf);
4413 } else {
4414 struct ssh_rportfwd *pf;
4415 pf = smalloc(sizeof(*pf));
4416 strcpy(pf->dhost, host);
4417 pf->dport = dport;
4418 pf->sport = sport;
4419 if (add234(ssh_rportfwds, pf) != pf) {
4420 sprintf(buf,
95bc8819 4421 "Duplicate remote port forwarding to %s:%d",
bc240b21 4422 host, dport);
4423 logevent(buf);
4424 sfree(pf);
4425 } else {
4426 sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
4427 sport, host, dport);
4428 logevent(buf);
4429 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4430 ssh2_pkt_addstring("tcpip-forward");
4431 ssh2_pkt_addbool(1);/* want reply */
4432 ssh2_pkt_addstring("127.0.0.1");
4433 ssh2_pkt_adduint32(sport);
4434 ssh2_pkt_send();
4435
4436 do {
4437 crWaitUntilV(ispkt);
4438 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4439 unsigned i = ssh2_pkt_getuint32();
4440 struct ssh_channel *c;
4441 c = find234(ssh_channels, &i, ssh_channelfind);
4442 if (!c)
4443 continue;/* nonexistent channel */
5471d09a 4444 c->v.v2.remwindow += ssh2_pkt_getuint32();
bc240b21 4445 }
4446 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4447
4448 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4449 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
4450 bombout(("Server got confused by port forwarding request"));
4451 crReturnV;
4452 }
4453 logevent("Server refused this port forwarding");
4454 } else {
4455 logevent("Remote port forwarding enabled");
4456 }
4457 }
4458 }
4459 }
4460 }
4461 }
4462
4463 /*
36c2a3e9 4464 * Potentially enable agent forwarding.
4465 */
4466 if (cfg.agentfwd && agent_exists()) {
32874aea 4467 logevent("Requesting OpenSSH-style agent forwarding");
4468 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4469 ssh2_pkt_adduint32(mainchan->remoteid);
4470 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4471 ssh2_pkt_addbool(1); /* want reply */
4472 ssh2_pkt_send();
4473
4474 do {
4475 crWaitUntilV(ispkt);
4476 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4477 unsigned i = ssh2_pkt_getuint32();
4478 struct ssh_channel *c;
4479 c = find234(ssh_channels, &i, ssh_channelfind);
4480 if (!c)
4481 continue; /* nonexistent channel */
5471d09a 4482 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4483 }
4484 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4485
4486 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4487 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4488 bombout(
4489 ("Server got confused by agent forwarding request"));
4490 crReturnV;
4491 }
4492 logevent("Agent forwarding refused");
4493 } else {
4494 logevent("Agent forwarding enabled");
36c2a3e9 4495 ssh_agentfwd_enabled = TRUE;
32874aea 4496 }
36c2a3e9 4497 }
4498
4499 /*
7cca0d81 4500 * Now allocate a pty for the session.
4501 */
67779be7 4502 if (!cfg.nopty) {
32874aea 4503 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4504 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4505 ssh2_pkt_addstring("pty-req");
4506 ssh2_pkt_addbool(1); /* want reply */
4507 ssh2_pkt_addstring(cfg.termtype);
4508 ssh2_pkt_adduint32(cols);
4509 ssh2_pkt_adduint32(rows);
4510 ssh2_pkt_adduint32(0); /* pixel width */
4511 ssh2_pkt_adduint32(0); /* pixel height */
4512 ssh2_pkt_addstring_start();
4513 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4514 ssh2_pkt_send();
4515 ssh_state = SSH_STATE_INTERMED;
4516
4517 do {
4518 crWaitUntilV(ispkt);
4519 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4520 unsigned i = ssh2_pkt_getuint32();
4521 struct ssh_channel *c;
4522 c = find234(ssh_channels, &i, ssh_channelfind);
4523 if (!c)
4524 continue; /* nonexistent channel */
5471d09a 4525 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4526 }
4527 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4528
4529 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4530 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4531 bombout(("Server got confused by pty request"));
4532 crReturnV;
4533 }
4534 c_write_str("Server refused to allocate pty\r\n");
4535 ssh_editing = ssh_echoing = 1;
4536 } else {
4537 logevent("Allocated pty");
4538 }
0965bee0 4539 } else {
32874aea 4540 ssh_editing = ssh_echoing = 1;
7cca0d81 4541 }
4542
4543 /*
fd5e5847 4544 * Start a shell or a remote command. We may have to attempt
4545 * this twice if the config data has provided a second choice
4546 * of command.
7cca0d81 4547 */
fd5e5847 4548 while (1) {
4549 int subsys;
4550 char *cmd;
4551
4552 if (ssh_fallback_cmd) {
4553 subsys = cfg.ssh_subsys2;
4554 cmd = cfg.remote_cmd_ptr2;
4555 } else {
4556 subsys = cfg.ssh_subsys;
4557 cmd = cfg.remote_cmd_ptr;
4558 }
4559
4560 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4561 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4562 if (subsys) {
4563 ssh2_pkt_addstring("subsystem");
4564 ssh2_pkt_addbool(1); /* want reply */
4565 ssh2_pkt_addstring(cmd);
4566 } else if (*cmd) {
4567 ssh2_pkt_addstring("exec");
4568 ssh2_pkt_addbool(1); /* want reply */
4569 ssh2_pkt_addstring(cmd);
4570 } else {
4571 ssh2_pkt_addstring("shell");
4572 ssh2_pkt_addbool(1); /* want reply */
32874aea 4573 }
fd5e5847 4574 ssh2_pkt_send();
4575 do {
4576 crWaitUntilV(ispkt);
4577 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4578 unsigned i = ssh2_pkt_getuint32();
4579 struct ssh_channel *c;
4580 c = find234(ssh_channels, &i, ssh_channelfind);
4581 if (!c)
4582 continue; /* nonexistent channel */
4583 c->v.v2.remwindow += ssh2_pkt_getuint32();
4584 }
4585 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4586 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4587 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4588 bombout(("Server got confused by shell/command request"));
4589 crReturnV;
4590 }
4591 /*
4592 * We failed to start the command. If this is the
4593 * fallback command, we really are finished; if it's
4594 * not, and if the fallback command exists, try falling
4595 * back to it before complaining.
4596 */
4597 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
4598 logevent("Primary command failed; attempting fallback");
4599 ssh_fallback_cmd = TRUE;
4600 continue;
4601 }
4602 bombout(("Server refused to start a shell/command"));
32874aea 4603 crReturnV;
fd5e5847 4604 } else {
4605 logevent("Started a shell/command");
32874aea 4606 }
fd5e5847 4607 break;
7cca0d81 4608 }
4609
6e48c3fe 4610 ssh_state = SSH_STATE_SESSION;
4611 if (size_needed)
4612 ssh_size();
3687d221 4613 if (eof_needed)
32874aea 4614 ssh_special(TS_EOF);
6e48c3fe 4615
7cca0d81 4616 /*
4617 * Transfer data!
4618 */
32874aea 4619 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 4620 ssh_send_ok = 1;
7cca0d81 4621 while (1) {
32874aea 4622 static int try_send;
e5574168 4623 crReturnV;
32874aea 4624 try_send = FALSE;
7cca0d81 4625 if (ispkt) {
4626 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
32874aea 4627 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4628 char *data;
4629 int length;
4630 unsigned i = ssh2_pkt_getuint32();
4631 struct ssh_channel *c;
4632 c = find234(ssh_channels, &i, ssh_channelfind);
4633 if (!c)
4634 continue; /* nonexistent channel */
4635 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4636 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4637 continue; /* extended but not stderr */
4638 ssh2_pkt_getstring(&data, &length);
4639 if (data) {
5471d09a 4640 int bufsize;
4641 c->v.v2.locwindow -= length;
32874aea 4642 switch (c->type) {
4643 case CHAN_MAINSESSION:
5471d09a 4644 bufsize =
4645 from_backend(pktin.type ==
4646 SSH2_MSG_CHANNEL_EXTENDED_DATA,
4647 data, length);
32874aea 4648 break;
4649 case CHAN_X11:
5471d09a 4650 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 4651 break;
d74d141c 4652 case CHAN_SOCKDATA:
5471d09a 4653 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 4654 break;
36c2a3e9 4655 case CHAN_AGENT:
32874aea 4656 while (length > 0) {
4657 if (c->u.a.lensofar < 4) {
4658 int l = min(4 - c->u.a.lensofar, length);
4659 memcpy(c->u.a.msglen + c->u.a.lensofar,
4660 data, l);
4661 data += l;
4662 length -= l;
4663 c->u.a.lensofar += l;
4664 }
4665 if (c->u.a.lensofar == 4) {
4666 c->u.a.totallen =
4667 4 + GET_32BIT(c->u.a.msglen);
4668 c->u.a.message = smalloc(c->u.a.totallen);
4669 memcpy(c->u.a.message, c->u.a.msglen, 4);
4670 }
4671 if (c->u.a.lensofar >= 4 && length > 0) {
4672 int l =
4673 min(c->u.a.totallen - c->u.a.lensofar,
4674 length);
4675 memcpy(c->u.a.message + c->u.a.lensofar,
4676 data, l);
4677 data += l;
4678 length -= l;
4679 c->u.a.lensofar += l;
4680 }
4681 if (c->u.a.lensofar == c->u.a.totallen) {
4682 void *reply, *sentreply;
4683 int replylen;
4684 agent_query(c->u.a.message,
4685 c->u.a.totallen, &reply,
4686 &replylen);
4687 if (reply)
4688 sentreply = reply;
4689 else {
4690 /* Fake SSH_AGENT_FAILURE. */
4691 sentreply = "\0\0\0\1\5";
4692 replylen = 5;
4693 }
4694 ssh2_add_channel_data(c, sentreply,
4695 replylen);
36c2a3e9 4696 try_send = TRUE;
32874aea 4697 if (reply)
4698 sfree(reply);
4699 sfree(c->u.a.message);
4700 c->u.a.lensofar = 0;
4701 }
4702 }
5471d09a 4703 bufsize = 0;
32874aea 4704 break;
4705 }
4706 /*
5471d09a 4707 * If we are not buffering too much data,
4708 * enlarge the window again at the remote side.
32874aea 4709 */
5471d09a 4710 if (bufsize < OUR_V2_WINSIZE)
4711 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 4712 }
7cca0d81 4713 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
32874aea 4714 ssh_state = SSH_STATE_CLOSED;
d211621f 4715 logevent("Received disconnect message");
32874aea 4716 crReturnV;
7cca0d81 4717 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
32874aea 4718 continue; /* exit status et al; ignore (FIXME?) */
d211621f 4719 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
32874aea 4720 unsigned i = ssh2_pkt_getuint32();
4721 struct ssh_channel *c;
4722
4723 c = find234(ssh_channels, &i, ssh_channelfind);
4724 if (!c)
4725 continue; /* nonexistent channel */
4726
4727 if (c->type == CHAN_X11) {
4728 /*
4729 * Remote EOF on an X11 channel means we should
4730 * wrap up and close the channel ourselves.
4731 */
4732 x11_close(c->u.x11.s);
4733 sshfwd_close(c);
4734 } else if (c->type == CHAN_AGENT) {
36c2a3e9 4735 sshfwd_close(c);
d74d141c 4736 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 4737 pfd_close(c->u.pfd.s);
4738 sshfwd_close(c);
36c2a3e9 4739 }
d211621f 4740 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
32874aea 4741 unsigned i = ssh2_pkt_getuint32();
4742 struct ssh_channel *c;
4743
4744 c = find234(ssh_channels, &i, ssh_channelfind);
4745 if (!c)
4746 continue; /* nonexistent channel */
32874aea 4747 /* Do pre-close processing on the channel. */
4748 switch (c->type) {
4749 case CHAN_MAINSESSION:
4750 break; /* nothing to see here, move along */
4751 case CHAN_X11:
92f157bd 4752 if (c->u.x11.s != NULL)
4753 x11_close(c->u.x11.s);
4754 sshfwd_close(c);
32874aea 4755 break;
4756 case CHAN_AGENT:
92f157bd 4757 sshfwd_close(c);
32874aea 4758 break;
d74d141c 4759 case CHAN_SOCKDATA:
92f157bd 4760 if (c->u.pfd.s != NULL)
4761 pfd_close(c->u.pfd.s);
4762 sshfwd_close(c);
bc240b21 4763 break;
32874aea 4764 }
92f157bd 4765 if (c->closes == 0) {
4766 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4767 ssh2_pkt_adduint32(c->remoteid);
4768 ssh2_pkt_send();
4769 }
32874aea 4770 del234(ssh_channels, c);
5471d09a 4771 bufchain_clear(&c->v.v2.outbuffer);
32874aea 4772 sfree(c);
4773
4774 /*
4775 * See if that was the last channel left open.
4776 */
4777 if (count234(ssh_channels) == 0) {
4778 logevent("All channels closed. Disconnecting");
4779 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4780 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4781 ssh2_pkt_addstring("All open channels closed");
4782 ssh2_pkt_addstring("en"); /* language tag */
4783 ssh2_pkt_send();
4784 ssh_state = SSH_STATE_CLOSED;
4785 crReturnV;
4786 }
4787 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 4788 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
32874aea 4789 unsigned i = ssh2_pkt_getuint32();
4790 struct ssh_channel *c;
4791 c = find234(ssh_channels, &i, ssh_channelfind);
4792 if (!c)
4793 continue; /* nonexistent channel */
5471d09a 4794 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4795 try_send = TRUE;
bc240b21 4796 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4797 unsigned i = ssh2_pkt_getuint32();
4798 struct ssh_channel *c;
4799 c = find234(ssh_channels, &i, ssh_channelfind);
4800 if (!c)
4801 continue; /* nonexistent channel */
4802 if (c->type != CHAN_SOCKDATA_DORMANT)
4803 continue; /* dunno why they're confirming this */
4804 c->remoteid = ssh2_pkt_getuint32();
4805 c->type = CHAN_SOCKDATA;
4806 c->closes = 0;
5471d09a 4807 c->v.v2.remwindow = ssh2_pkt_getuint32();
4808 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4809 bufchain_init(&c->v.v2.outbuffer);
bc240b21 4810 pfd_confirm(c->u.pfd.s);
724cface 4811 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
4812 unsigned i = ssh2_pkt_getuint32();
4813 struct ssh_channel *c;
4814 c = find234(ssh_channels, &i, ssh_channelfind);
4815 if (!c)
4816 continue; /* nonexistent channel */
4817 if (c->type != CHAN_SOCKDATA_DORMANT)
4818 continue; /* dunno why they're failing this */
4819
4820 logevent("Forwarded connection refused by server");
4821
4822 pfd_close(c->u.pfd.s);
4823
4824 del234(ssh_channels, c);
4825 sfree(c);
783415f8 4826 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 4827 char *type;
4828 int typelen;
4829 char *error = NULL;
4830 struct ssh_channel *c;
bc240b21 4831 unsigned remid, winsize, pktsize;
32874aea 4832 ssh2_pkt_getstring(&type, &typelen);
4833 c = smalloc(sizeof(struct ssh_channel));
4834
bc240b21 4835 remid = ssh2_pkt_getuint32();
4836 winsize = ssh2_pkt_getuint32();
4837 pktsize = ssh2_pkt_getuint32();
4838
32874aea 4839 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4840 if (!ssh_X11_fwd_enabled)
4841 error = "X11 forwarding is not enabled";
4842 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4843 NULL) {
4844 error = "Unable to open an X11 connection";
4845 } else {
4846 c->type = CHAN_X11;
4847 }
bc240b21 4848 } else if (typelen == 15 &&
4849 !memcmp(type, "forwarded-tcpip", 15)) {
4850 struct ssh_rportfwd pf, *realpf;
4851 char *dummy;
4852 int dummylen;
4853 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
4854 pf.sport = ssh2_pkt_getuint32();
4855 realpf = find234(ssh_rportfwds, &pf, NULL);
4856 if (realpf == NULL) {
4857 error = "Remote port is not recognised";
4858 } else {
4859 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
4860 realpf->dport, c);
4861 char buf[1024];
4862 sprintf(buf, "Received remote port open request for %s:%d",
4863 realpf->dhost, realpf->dport);
4864 logevent(buf);
4865 if (e != NULL) {
4866 sprintf(buf, "Port open failed: %s", e);
4867 logevent(buf);
4868 error = "Port open failed";
4869 } else {
4870 logevent("Forwarded port opened successfully");
4871 c->type = CHAN_SOCKDATA;
4872 }
4873 }
32874aea 4874 } else if (typelen == 22 &&
36c2a3e9 4875 !memcmp(type, "auth-agent@openssh.com", 3)) {
32874aea 4876 if (!ssh_agentfwd_enabled)
4877 error = "Agent forwarding is not enabled";
36c2a3e9 4878 else {
32874aea 4879 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 4880 c->u.a.lensofar = 0;
32874aea 4881 }
4882 } else {
4883 error = "Unsupported channel type requested";
4884 }
4885
bc240b21 4886 c->remoteid = remid;
32874aea 4887 if (error) {
4888 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4889 ssh2_pkt_adduint32(c->remoteid);
4890 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4891 ssh2_pkt_addstring(error);
4892 ssh2_pkt_addstring("en"); /* language tag */
4893 ssh2_pkt_send();
4894 sfree(c);
4895 } else {
4896 c->localid = alloc_channel_id();
4897 c->closes = 0;
5471d09a 4898 c->v.v2.locwindow = OUR_V2_WINSIZE;
4899 c->v.v2.remwindow = winsize;
4900 c->v.v2.remmaxpkt = pktsize;
4901 bufchain_init(&c->v.v2.outbuffer);
32874aea 4902 add234(ssh_channels, c);
4903 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4904 ssh2_pkt_adduint32(c->remoteid);
4905 ssh2_pkt_adduint32(c->localid);
5471d09a 4906 ssh2_pkt_adduint32(c->v.v2.locwindow);
32874aea 4907 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4908 ssh2_pkt_send();
4909 }
7cca0d81 4910 } else {
8d5de777 4911 bombout(("Strange packet received: type %d", pktin.type));
32874aea 4912 crReturnV;
7cca0d81 4913 }
4914 } else {
32874aea 4915 /*
4916 * We have spare data. Add it to the channel buffer.
4917 */
4918 ssh2_add_channel_data(mainchan, in, inlen);
4919 try_send = TRUE;
4920 }
4921 if (try_send) {
4922 int i;
4923 struct ssh_channel *c;
4924 /*
4925 * Try to send data on all channels if we can.
4926 */
5471d09a 4927 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
4928 int bufsize = ssh2_try_send(c);
4929 if (bufsize == 0) {
4930 switch (c->type) {
4931 case CHAN_MAINSESSION:
4932 /* stdin need not receive an unthrottle
4933 * notification since it will be polled */
4934 break;
4935 case CHAN_X11:
4936 x11_unthrottle(c->u.x11.s);
4937 break;
4938 case CHAN_AGENT:
4939 /* agent sockets are request/response and need no
4940 * buffer management */
4941 break;
4942 case CHAN_SOCKDATA:
4943 pfd_unthrottle(c->u.pfd.s);
4944 break;
4945 }
4946 }
4947 }
7cca0d81 4948 }
e5574168 4949 }
4950
4951 crFinishV;
4952}
4953
4954/*
7cca0d81 4955 * Handle the top-level SSH2 protocol.
4956 */
4957static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4958{
4959 if (do_ssh2_transport(in, inlen, ispkt) == 0)
32874aea 4960 return;
7cca0d81 4961 do_ssh2_authconn(in, inlen, ispkt);
4962}
4963
4964/*
8df7a775 4965 * Called to set up the connection.
374330e2 4966 *
4967 * Returns an error message, or NULL on success.
374330e2 4968 */
32874aea 4969static char *ssh_init(char *host, int port, char **realhost)
4970{
fb09bf1c 4971 char *p;
32874aea 4972
8f203108 4973#ifdef MSCRYPTOAPI
32874aea 4974 if (crypto_startup() == 0)
8f203108 4975 return "Microsoft high encryption pack not installed!";
4976#endif
374330e2 4977
8df7a775 4978 ssh_send_ok = 0;
0965bee0 4979 ssh_editing = 0;
4980 ssh_echoing = 0;
5471d09a 4981 ssh1_throttle_count = 0;
4982 ssh_overall_bufsize = 0;
fd5e5847 4983 ssh_fallback_cmd = 0;
8df7a775 4984
fb09bf1c 4985 p = connect_to_host(host, port, realhost);
4986 if (p != NULL)
4987 return p;
374330e2 4988
374330e2 4989 return NULL;
4990}
4991
4992/*
374330e2 4993 * Called to send data down the Telnet connection.
4994 */
5471d09a 4995static int ssh_send(char *buf, int len)
32874aea 4996{
f78051a1 4997 if (s == NULL || ssh_protocol == NULL)
5471d09a 4998 return 0;
374330e2 4999
5000 ssh_protocol(buf, len, 0);
5471d09a 5001
5002 return ssh_sendbuffer();
5003}
5004
5005/*
5006 * Called to query the current amount of buffered stdin data.
5007 */
5008static int ssh_sendbuffer(void)
5009{
5010 int override_value;
5011
5012 if (s == NULL || ssh_protocol == NULL)
5013 return 0;
5014
5015 /*
5016 * If the SSH socket itself has backed up, add the total backup
5017 * size on that to any individual buffer on the stdin channel.
5018 */
5019 override_value = 0;
5020 if (ssh_throttled_all)
5021 override_value = ssh_overall_bufsize;
5022
5023 if (ssh_version == 1) {
5024 return override_value;
5025 } else if (ssh_version == 2) {
5026 if (!mainchan || mainchan->closes > 0)
5027 return override_value;
5028 else
5029 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5030 }
5031
5032 return 0;
374330e2 5033}
5034
5035/*
6e48c3fe 5036 * Called to set the size of the window from SSH's POV.
374330e2 5037 */
32874aea 5038static void ssh_size(void)
5039{
374330e2 5040 switch (ssh_state) {
5041 case SSH_STATE_BEFORE_SIZE:
3687d221 5042 case SSH_STATE_PREPACKET:
21248260 5043 case SSH_STATE_CLOSED:
374330e2 5044 break; /* do nothing */
5045 case SSH_STATE_INTERMED:
5046 size_needed = TRUE; /* buffer for later */
5047 break;
5048 case SSH_STATE_SESSION:
32874aea 5049 if (!cfg.nopty) {
5050 if (ssh_version == 1) {
5051 send_packet(SSH1_CMSG_WINDOW_SIZE,
5052 PKT_INT, rows, PKT_INT, cols,
5053 PKT_INT, 0, PKT_INT, 0, PKT_END);
5054 } else {
5055 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5056 ssh2_pkt_adduint32(mainchan->remoteid);
5057 ssh2_pkt_addstring("window-change");
5058 ssh2_pkt_addbool(0);
5059 ssh2_pkt_adduint32(cols);
5060 ssh2_pkt_adduint32(rows);
5061 ssh2_pkt_adduint32(0);
5062 ssh2_pkt_adduint32(0);
5063 ssh2_pkt_send();
5064 }
5065 }
5066 break;
374330e2 5067 }
5068}
5069
5070/*
6abbf9e3 5071 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5072 * can send an EOF and collect resulting output (e.g. `plink
5073 * hostname sort').
374330e2 5074 */
32874aea 5075static void ssh_special(Telnet_Special code)
5076{
6abbf9e3 5077 if (code == TS_EOF) {
32874aea 5078 if (ssh_state != SSH_STATE_SESSION) {
5079 /*
5080 * Buffer the EOF in case we are pre-SESSION, so we can
5081 * send it as soon as we reach SESSION.
5082 */
5083 if (code == TS_EOF)
5084 eof_needed = TRUE;
5085 return;
5086 }
5087 if (ssh_version == 1) {
5088 send_packet(SSH1_CMSG_EOF, PKT_END);
5089 } else {
5090 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5091 ssh2_pkt_adduint32(mainchan->remoteid);
5092 ssh2_pkt_send();
5093 }
5094 logevent("Sent EOF message");
ec55b220 5095 } else if (code == TS_PING) {
32874aea 5096 if (ssh_state == SSH_STATE_CLOSED
5097 || ssh_state == SSH_STATE_PREPACKET) return;
5098 if (ssh_version == 1) {
5099 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5100 } else {
5101 ssh2_pkt_init(SSH2_MSG_IGNORE);
5102 ssh2_pkt_addstring_start();
5103 ssh2_pkt_send();
5104 }
6abbf9e3 5105 } else {
32874aea 5106 /* do nothing */
6abbf9e3 5107 }
374330e2 5108}
5109
d74d141c 5110void *new_sock_channel(Socket s)
5111{
5112 struct ssh_channel *c;
5113 c = smalloc(sizeof(struct ssh_channel));
5114
5115 if (c) {
bc240b21 5116 c->remoteid = -1; /* to be set when open confirmed */
d74d141c 5117 c->localid = alloc_channel_id();
5118 c->closes = 0;
bc240b21 5119 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 5120 c->u.pfd.s = s;
5121 add234(ssh_channels, c);
5122 }
5123 return c;
5124}
5125
5471d09a 5126/*
5127 * This is called when stdout/stderr (the entity to which
5128 * from_backend sends data) manages to clear some backlog.
5129 */
5130void ssh_unthrottle(int bufsize)
5131{
5132 if (ssh_version == 1) {
90347b95 5133 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5471d09a 5134 ssh1_stdout_throttling = 0;
5135 ssh1_throttle(-1);
5136 }
5137 } else {
5138 if (mainchan && mainchan->closes == 0)
5139 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5140 }
5141}
5142
d74d141c 5143void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5144{
5145 struct ssh_channel *c = (struct ssh_channel *)channel;
5146 char buf[1024];
5147
5148 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5149 logevent(buf);
5150
bc240b21 5151 if (ssh_version == 1) {
5152 send_packet(SSH1_MSG_PORT_OPEN,
5153 PKT_INT, c->localid,
5154 PKT_STR, hostname,
5155 PKT_INT, port,
5156 //PKT_STR, <org:orgport>,
5157 PKT_END);
5158 } else {
5159 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5160 ssh2_pkt_addstring("direct-tcpip");
5161 ssh2_pkt_adduint32(c->localid);
5471d09a 5162 c->v.v2.locwindow = OUR_V2_WINSIZE;
5163 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
bc240b21 5164 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5165 ssh2_pkt_addstring(hostname);
5166 ssh2_pkt_adduint32(port);
5167 /*
5168 * We make up values for the originator data; partly it's
5169 * too much hassle to keep track, and partly I'm not
5170 * convinced the server should be told details like that
5171 * about my local network configuration.
5172 */
5173 ssh2_pkt_addstring("client-side-connection");
5174 ssh2_pkt_adduint32(0);
5175 ssh2_pkt_send();
5176 }
d74d141c 5177}
5178
5179
32874aea 5180static Socket ssh_socket(void)
5181{
5182 return s;
5183}
8ccc75b0 5184
32874aea 5185static int ssh_sendok(void)
5186{
5187 return ssh_send_ok;
5188}
fb09bf1c 5189
32874aea 5190static int ssh_ldisc(int option)
5191{
5192 if (option == LD_ECHO)
5193 return ssh_echoing;
5194 if (option == LD_EDIT)
5195 return ssh_editing;
0965bee0 5196 return FALSE;
5197}
5198
374330e2 5199Backend ssh_backend = {
5200 ssh_init,
374330e2 5201 ssh_send,
5471d09a 5202 ssh_sendbuffer,
374330e2 5203 ssh_size,
4017be6d 5204 ssh_special,
8ccc75b0 5205 ssh_socket,
97db3be4 5206 ssh_sendok,
0965bee0 5207 ssh_ldisc,
5471d09a 5208 ssh_unthrottle,
97db3be4 5209 22
bc240b21 5210};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator