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I've decided that trying to do wildcards in PSFTP as a special case
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5
6#include "putty.h"
dacbd0e8 7#include "tree234.h"
fb09bf1c 8#include "ssh.h"
374330e2 9
10#ifndef FALSE
11#define FALSE 0
12#endif
13#ifndef TRUE
14#define TRUE 1
15#endif
16
32874aea 17#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20#define SSH1_CMSG_USER 4 /* 0x4 */
21#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29#define SSH1_SMSG_SUCCESS 14 /* 0xe */
30#define SSH1_SMSG_FAILURE 15 /* 0xf */
31#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34#define SSH1_CMSG_EOF 19 /* 0x13 */
35#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46#define SSH1_MSG_IGNORE 32 /* 0x20 */
47#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50#define SSH1_MSG_DEBUG 36 /* 0x24 */
51#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
58
59#define SSH1_AUTH_TIS 5 /* 0x5 */
60#define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 63/* Mask for protoflags we will echo back to server if seen */
32874aea 64#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
66#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67#define SSH2_MSG_IGNORE 2 /* 0x2 */
68#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69#define SSH2_MSG_DEBUG 4 /* 0x4 */
70#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72#define SSH2_MSG_KEXINIT 20 /* 0x14 */
73#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 86#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 88#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
102
00db133f 103/*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
d1aaf71d 107#define SSH2_PKTCTX_DHGROUP 0x0001
00db133f 108#define SSH2_PKTCTX_DHGEX 0x0002
109#define SSH2_PKTCTX_PUBLICKEY 0x0010
110#define SSH2_PKTCTX_PASSWORD 0x0020
111#define SSH2_PKTCTX_KBDINTER 0x0040
112#define SSH2_PKTCTX_AUTH_MASK 0x00F0
113
32874aea 114#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 129
130static const char *const ssh2_disconnect_reasons[] = {
131 NULL,
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
147};
9005f3ba 148
32874aea 149#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 153
32874aea 154#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 155
7d503c31 156/*
157 * Various remote-bug flags.
158 */
159#define BUG_CHOKES_ON_SSH1_IGNORE 1
160#define BUG_SSH2_HMAC 2
bd358db1 161#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 162#define BUG_CHOKES_ON_RSA 8
1dd353b5 163#define BUG_SSH2_RSA_PADDING 16
088bde77 164#define BUG_SSH2_DERIVEKEY 32
83e7d008 165/* 64 was BUG_SSH2_DH_GEX, now spare */
dda87a28 166#define BUG_SSH2_PK_SESSIONID 128
bd358db1 167
00db133f 168#define translate(x) if (type == x) return #x
51470298 169#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
ae9ae89f 170static char *ssh1_pkt_type(int type)
00db133f 171{
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
213 return "unknown";
214}
ae9ae89f 215static char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 216{
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
d1aaf71d 225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
00db133f 227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
253 return "unknown";
254}
255#undef translate
256#undef translatec
7d503c31 257
fb09bf1c 258#define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
263
264#define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
269
9a10ecf4 270/* Enumeration values for fields in SSH-1 packets */
271enum {
272 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
273 /* These values are for communicating relevant semantics of
274 * fields to the packet logging code. */
275 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
276};
972a41c8 277
acddebd9 278/*
279 * Coroutine mechanics for the sillier bits of the code. If these
280 * macros look impenetrable to you, you might find it helpful to
281 * read
282 *
283 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
284 *
285 * which explains the theory behind these macros.
b624d1e6 286 *
287 * In particular, if you are getting `case expression not constant'
288 * errors when building with MS Visual Studio, this is because MS's
289 * Edit and Continue debugging feature causes their compiler to
290 * violate ANSI C. To disable Edit and Continue debugging:
291 *
292 * - right-click ssh.c in the FileView
293 * - click Settings
294 * - select the C/C++ tab and the General category
295 * - under `Debug info:', select anything _other_ than `Program
296 * Database for Edit and Continue'.
acddebd9 297 */
51470298 298#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
299#define crState(t) \
300 struct t *s; \
3d88e64d 301 if (!ssh->t) ssh->t = snew(struct t); \
51470298 302 s = ssh->t;
303#define crFinish(z) } *crLine = 0; return (z); }
304#define crFinishV } *crLine = 0; return; }
374330e2 305#define crReturn(z) \
306 do {\
51470298 307 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 308 } while (0)
309#define crReturnV \
310 do {\
51470298 311 *crLine=__LINE__; return; case __LINE__:;\
374330e2 312 } while (0)
51470298 313#define crStop(z) do{ *crLine = 0; return (z); }while(0)
314#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 315#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 316#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 317
51470298 318typedef struct ssh_tag *Ssh;
ff3187f6 319struct Packet;
320
321static struct Packet *ssh2_pkt_init(int pkt_type);
322static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
323static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
324static void ssh2_pkt_addstring_start(struct Packet *);
325static void ssh2_pkt_addstring_str(struct Packet *, char *data);
326static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
327static void ssh2_pkt_addstring(struct Packet *, char *data);
d8baa528 328static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
ff3187f6 329static void ssh2_pkt_addmp(struct Packet *, Bignum b);
330static int ssh2_pkt_construct(Ssh, struct Packet *);
331static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 332static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 333static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
334 struct Packet *pktin);
335static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
336 struct Packet *pktin);
3d63ca2e 337
5471d09a 338/*
339 * Buffer management constants. There are several of these for
340 * various different purposes:
341 *
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
346 * happen very often.
347 *
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
354 *
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
356 * channels.
357 */
358
359#define SSH1_BUFFER_LIMIT 32768
360#define SSH_MAX_BACKLOG 32768
361#define OUR_V2_WINSIZE 16384
d74d141c 362
85cc02bb 363const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 364
e0e1a00d 365static void *nullmac_make_context(void)
366{
367 return NULL;
368}
369static void nullmac_free_context(void *handle)
370{
371}
372static void nullmac_key(void *handle, unsigned char *key)
32874aea 373{
374}
e0e1a00d 375static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 376 unsigned long seq)
377{
378}
e0e1a00d 379static int nullmac_verify(void *handle, unsigned char *blk, int len,
380 unsigned long seq)
32874aea 381{
382 return 1;
383}
57476f6b 384const static struct ssh_mac ssh_mac_none = {
e0e1a00d 385 nullmac_make_context, nullmac_free_context, nullmac_key,
386 nullmac_generate, nullmac_verify, "none", 0
e5574168 387};
8b2715b2 388const static struct ssh_mac *macs[] = {
32874aea 389 &ssh_sha1, &ssh_md5, &ssh_mac_none
390};
8b2715b2 391const static struct ssh_mac *buggymacs[] = {
32874aea 392 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
393};
e5574168 394
5366aed8 395static void *ssh_comp_none_init(void)
396{
397 return NULL;
398}
399static void ssh_comp_none_cleanup(void *handle)
32874aea 400{
401}
5366aed8 402static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 403 unsigned char **outblock, int *outlen)
404{
405 return 0;
406}
5366aed8 407static int ssh_comp_none_disable(void *handle)
32874aea 408{
4ba9b64b 409 return 0;
410}
57476f6b 411const static struct ssh_compress ssh_comp_none = {
4ba9b64b 412 "none",
5366aed8 413 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_disable, NULL
e5574168 416};
4ba9b64b 417extern const struct ssh_compress ssh_zlib;
418const static struct ssh_compress *compressions[] = {
32874aea 419 &ssh_zlib, &ssh_comp_none
420};
374330e2 421
32874aea 422enum { /* channel types */
783415f8 423 CHAN_MAINSESSION,
424 CHAN_X11,
425 CHAN_AGENT,
bc240b21 426 CHAN_SOCKDATA,
427 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 428};
429
dacbd0e8 430/*
431 * 2-3-4 tree storing channels.
432 */
433struct ssh_channel {
51470298 434 Ssh ssh; /* pointer back to main context */
d211621f 435 unsigned remoteid, localid;
dacbd0e8 436 int type;
0357890f 437 /*
438 * In SSH1, this value contains four bits:
439 *
440 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
441 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
442 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
443 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
444 *
445 * A channel is completely finished with when all four bits are set.
446 */
dacbd0e8 447 int closes;
5471d09a 448 union {
449 struct ssh1_data_channel {
450 int throttling;
451 } v1;
452 struct ssh2_data_channel {
453 bufchain outbuffer;
454 unsigned remwindow, remmaxpkt;
455 unsigned locwindow;
456 } v2;
457 } v;
dacbd0e8 458 union {
32874aea 459 struct ssh_agent_channel {
460 unsigned char *message;
461 unsigned char msglen[4];
a03c9f9c 462 unsigned lensofar, totallen;
32874aea 463 } a;
464 struct ssh_x11_channel {
465 Socket s;
466 } x11;
d74d141c 467 struct ssh_pfd_channel {
468 Socket s;
469 } pfd;
dacbd0e8 470 } u;
471};
57476f6b 472
d74d141c 473/*
bc240b21 474 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
475 * 2 use this structure in different ways, reflecting SSH 2's
476 * altogether saner approach to port forwarding.
477 *
478 * In SSH 1, you arrange a remote forwarding by sending the server
479 * the remote port number, and the local destination host:port.
480 * When a connection comes in, the server sends you back that
481 * host:port pair, and you connect to it. This is a ready-made
482 * security hole if you're not on the ball: a malicious server
483 * could send you back _any_ host:port pair, so if you trustingly
484 * connect to the address it gives you then you've just opened the
485 * entire inside of your corporate network just by connecting
486 * through it to a dodgy SSH server. Hence, we must store a list of
487 * host:port pairs we _are_ trying to forward to, and reject a
488 * connection request from the server if it's not in the list.
489 *
490 * In SSH 2, each side of the connection minds its own business and
491 * doesn't send unnecessary information to the other. You arrange a
492 * remote forwarding by sending the server just the remote port
493 * number. When a connection comes in, the server tells you which
494 * of its ports was connected to; and _you_ have to remember what
495 * local host:port pair went with that port number.
496 *
06fadff5 497 * Hence, in SSH 1 this structure is indexed by destination
498 * host:port pair, whereas in SSH 2 it is indexed by source port.
d74d141c 499 */
fda2feb1 500struct ssh_portfwd; /* forward declaration */
501
d74d141c 502struct ssh_rportfwd {
bc240b21 503 unsigned sport, dport;
504 char dhost[256];
06fadff5 505 char *sportdesc;
fda2feb1 506 struct ssh_portfwd *pfrec;
d74d141c 507};
fda2feb1 508#define free_rportfwd(pf) ( \
509 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
510
511/*
512 * Separately to the rportfwd tree (which is for looking up port
513 * open requests from the server), a tree of _these_ structures is
514 * used to keep track of all the currently open port forwardings,
515 * so that we can reconfigure in mid-session if the user requests
516 * it.
517 */
518struct ssh_portfwd {
519 int keep;
520 int type;
521 unsigned sport, dport;
522 char *saddr, *daddr;
523 struct ssh_rportfwd *remote;
524 void *local;
525};
526#define free_portfwd(pf) ( \
527 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr)) : (void)0 ), sfree(pf) )
d74d141c 528
57476f6b 529struct Packet {
530 long length;
531 int type;
b09eaa88 532 unsigned long sequence;
57476f6b 533 unsigned char *data;
534 unsigned char *body;
535 long savedpos;
536 long maxlen;
9442dd57 537 long encrypted_len; /* for SSH2 total-size counting */
ff3187f6 538
539 /*
540 * State associated with packet logging
541 */
542 int logmode;
543 int nblanks;
544 struct logblank_t *blanks;
57476f6b 545};
546
ff3187f6 547static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
548 struct Packet *pktin);
549static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
550 struct Packet *pktin);
b09eaa88 551static void ssh1_protocol_setup(Ssh ssh);
552static void ssh2_protocol_setup(Ssh ssh);
51470298 553static void ssh_size(void *handle, int width, int height);
554static void ssh_special(void *handle, Telnet_Special);
5471d09a 555static int ssh2_try_send(struct ssh_channel *c);
51470298 556static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
557static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 558static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 559static int ssh_sendbuffer(void *handle);
36f94d1f 560static void ssh_do_close(Ssh ssh);
ff3187f6 561static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
562static int ssh2_pkt_getbool(struct Packet *pkt);
563static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 564static void ssh2_timer(void *ctx, long now);
565static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
566 struct Packet *pktin);
57476f6b 567
51470298 568struct rdpkt1_state_tag {
57476f6b 569 long len, pad, biglen, to_read;
570 unsigned long realcrc, gotcrc;
571 unsigned char *p;
572 int i;
573 int chunk;
ff3187f6 574 struct Packet *pktin;
51470298 575};
57476f6b 576
51470298 577struct rdpkt2_state_tag {
960e736a 578 long len, pad, payload, packetlen, maclen;
579 int i;
580 int cipherblk;
581 unsigned long incoming_sequence;
ff3187f6 582 struct Packet *pktin;
51470298 583};
584
b09eaa88 585typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 586typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
587
588struct queued_handler;
589struct queued_handler {
590 int msg1, msg2;
591 chandler_fn_t handler;
592 void *ctx;
593 struct queued_handler *next;
594};
b09eaa88 595
51470298 596struct ssh_tag {
597 const struct plug_function_table *fn;
598 /* the above field _must_ be first in the structure */
599
600 SHA_State exhash, exhashbase;
601
602 Socket s;
603
b9d7bcad 604 void *ldisc;
a8327734 605 void *logctx;
b9d7bcad 606
51470298 607 unsigned char session_key[32];
608 int v1_compressing;
609 int v1_remote_protoflags;
610 int v1_local_protoflags;
611 int agentfwd_enabled;
612 int X11_fwd_enabled;
613 int remote_bugs;
614 const struct ssh_cipher *cipher;
371e569c 615 void *v1_cipher_ctx;
0183b242 616 void *crcda_ctx;
51470298 617 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 618 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 619 const struct ssh_mac *csmac, *scmac;
e0e1a00d 620 void *cs_mac_ctx, *sc_mac_ctx;
51470298 621 const struct ssh_compress *cscomp, *sccomp;
5366aed8 622 void *cs_comp_ctx, *sc_comp_ctx;
51470298 623 const struct ssh_kex *kex;
624 const struct ssh_signkey *hostkey;
625 unsigned char v2_session_id[20];
27cd7fc2 626 void *kex_ctx;
51470298 627
628 char *savedhost;
629 int savedport;
630 int send_ok;
631 int echoing, editing;
632
633 void *frontend;
634
db219738 635 int ospeed, ispeed; /* temporaries */
51470298 636 int term_width, term_height;
637
638 tree234 *channels; /* indexed by local id */
639 struct ssh_channel *mainchan; /* primary session channel */
640 int exitcode;
641
fda2feb1 642 tree234 *rportfwds, *portfwds;
51470298 643
644 enum {
645 SSH_STATE_PREPACKET,
646 SSH_STATE_BEFORE_SIZE,
647 SSH_STATE_INTERMED,
648 SSH_STATE_SESSION,
649 SSH_STATE_CLOSED
650 } state;
651
652 int size_needed, eof_needed;
653
590f6a5f 654 struct Packet **queue;
655 int queuelen, queuesize;
656 int queueing;
51470298 657 unsigned char *deferred_send_data;
658 int deferred_len, deferred_size;
659
660 /*
661 * Gross hack: pscp will try to start SFTP but fall back to
662 * scp1 if that fails. This variable is the means by which
663 * scp.c can reach into the SSH code and find out which one it
664 * got.
665 */
666 int fallback_cmd;
667
668 /*
669 * Used for username and password input.
670 */
671 char *userpass_input_buffer;
672 int userpass_input_buflen;
673 int userpass_input_bufpos;
674 int userpass_input_echo;
675
51470298 676 int pkt_ctx;
677
302121de 678 void *x11auth;
679
51470298 680 int version;
681 int v1_throttle_count;
682 int overall_bufsize;
683 int throttled_all;
684 int v1_stdout_throttling;
685 int v2_outgoing_sequence;
686
687 int ssh1_rdpkt_crstate;
688 int ssh2_rdpkt_crstate;
689 int do_ssh_init_crstate;
690 int ssh_gotdata_crstate;
51470298 691 int do_ssh1_login_crstate;
b09eaa88 692 int do_ssh1_connection_crstate;
51470298 693 int do_ssh2_transport_crstate;
694 int do_ssh2_authconn_crstate;
695
696 void *do_ssh_init_state;
697 void *do_ssh1_login_state;
698 void *do_ssh2_transport_state;
699 void *do_ssh2_authconn_state;
700
701 struct rdpkt1_state_tag rdpkt1_state;
702 struct rdpkt2_state_tag rdpkt2_state;
703
b09eaa88 704 /* ssh1 and ssh2 use this for different things, but both use it */
705 int protocol_initial_phase_done;
706
ff3187f6 707 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
708 struct Packet *pkt);
709 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 710
711 /*
712 * We maintain a full _copy_ of a Config structure here, not
713 * merely a pointer to it. That way, when we're passed a new
714 * one for reconfiguration, we can check the differences and
715 * potentially reconfigure port forwardings etc in mid-session.
716 */
717 Config cfg;
839f10db 718
719 /*
720 * Used to transfer data back from async agent callbacks.
721 */
722 void *agent_response;
723 int agent_response_len;
b09eaa88 724
725 /*
726 * Dispatch table for packet types that we may have to deal
727 * with at any time.
728 */
729 handler_fn_t packet_dispatch[256];
39934deb 730
731 /*
06fadff5 732 * Queues of one-off handler functions for success/failure
733 * indications from a request.
734 */
735 struct queued_handler *qhead, *qtail;
736
737 /*
39934deb 738 * This module deals with sending keepalives.
739 */
740 Pinger pinger;
9442dd57 741
742 /*
743 * Track incoming and outgoing data sizes and time, for
744 * size-based rekeys.
745 */
746 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 747 unsigned long max_data_size;
9442dd57 748 int kex_in_progress;
e6c1536e 749 long next_rekey, last_rekey;
51470298 750};
960e736a 751
382908ad 752#define logevent(s) logevent(ssh->frontend, s)
a8327734 753
754/* logevent, only printf-formatted. */
cbe2d68f 755static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 756{
757 va_list ap;
57356d63 758 char *buf;
a8327734 759
760 va_start(ap, fmt);
57356d63 761 buf = dupvprintf(fmt, ap);
a8327734 762 va_end(ap);
57356d63 763 logevent(buf);
57356d63 764 sfree(buf);
a8327734 765}
766
6b5cf8b4 767#define bombout(msg) \
768 do { \
769 char *text = dupprintf msg; \
36f94d1f 770 ssh_do_close(ssh); \
6b5cf8b4 771 logevent(text); \
772 connection_fatal(ssh->frontend, "%s", text); \
773 sfree(text); \
774 } while (0)
a8327734 775
9a10ecf4 776/* Functions to leave bits out of the SSH packet log file. */
777
ff3187f6 778static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 779{
780 if (ssh->cfg.logomitpass)
ff3187f6 781 pkt->logmode = blanktype;
9a10ecf4 782}
783
ff3187f6 784static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 785{
786 if (ssh->cfg.logomitdata)
ff3187f6 787 pkt->logmode = blanktype;
9a10ecf4 788}
789
ff3187f6 790static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 791{
ff3187f6 792 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 793}
794
32874aea 795static int ssh_channelcmp(void *av, void *bv)
796{
797 struct ssh_channel *a = (struct ssh_channel *) av;
798 struct ssh_channel *b = (struct ssh_channel *) bv;
799 if (a->localid < b->localid)
800 return -1;
801 if (a->localid > b->localid)
802 return +1;
dacbd0e8 803 return 0;
804}
32874aea 805static int ssh_channelfind(void *av, void *bv)
806{
807 unsigned *a = (unsigned *) av;
808 struct ssh_channel *b = (struct ssh_channel *) bv;
809 if (*a < b->localid)
810 return -1;
811 if (*a > b->localid)
812 return +1;
dacbd0e8 813 return 0;
814}
815
bc240b21 816static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 817{
818 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
819 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
820 int i;
bc240b21 821 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 822 return i < 0 ? -1 : +1;
bc240b21 823 if (a->dport > b->dport)
824 return +1;
825 if (a->dport < b->dport)
826 return -1;
827 return 0;
828}
829
830static int ssh_rportcmp_ssh2(void *av, void *bv)
831{
832 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
833 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 834
bc240b21 835 if (a->sport > b->sport)
d74d141c 836 return +1;
bc240b21 837 if (a->sport < b->sport)
838 return -1;
d74d141c 839 return 0;
840}
841
fda2feb1 842/*
843 * Special form of strcmp which can cope with NULL inputs. NULL is
844 * defined to sort before even the empty string.
845 */
846static int nullstrcmp(const char *a, const char *b)
847{
848 if (a == NULL && b == NULL)
849 return 0;
850 if (a == NULL)
851 return -1;
852 if (b == NULL)
853 return +1;
854 return strcmp(a, b);
855}
856
857static int ssh_portcmp(void *av, void *bv)
858{
859 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
860 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
861 int i;
862 if (a->type > b->type)
863 return +1;
864 if (a->type < b->type)
865 return -1;
866 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
867 return i < 0 ? -1 : +1;
868 if (a->sport > b->sport)
869 return +1;
870 if (a->sport < b->sport)
871 return -1;
872 if (a->type != 'D') {
873 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
874 return i < 0 ? -1 : +1;
875 if (a->dport > b->dport)
876 return +1;
877 if (a->dport < b->dport)
878 return -1;
879 }
880 return 0;
881}
882
51470298 883static int alloc_channel_id(Ssh ssh)
32874aea 884{
260f3dec 885 const unsigned CHANNEL_NUMBER_OFFSET = 256;
886 unsigned low, high, mid;
d2371c81 887 int tsize;
888 struct ssh_channel *c;
889
890 /*
891 * First-fit allocation of channel numbers: always pick the
892 * lowest unused one. To do this, binary-search using the
893 * counted B-tree to find the largest channel ID which is in a
894 * contiguous sequence from the beginning. (Precisely
895 * everything in that sequence must have ID equal to its tree
896 * index plus CHANNEL_NUMBER_OFFSET.)
897 */
51470298 898 tsize = count234(ssh->channels);
d2371c81 899
32874aea 900 low = -1;
901 high = tsize;
d2371c81 902 while (high - low > 1) {
903 mid = (high + low) / 2;
51470298 904 c = index234(ssh->channels, mid);
d2371c81 905 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
906 low = mid; /* this one is fine */
907 else
908 high = mid; /* this one is past it */
909 }
910 /*
911 * Now low points to either -1, or the tree index of the
912 * largest ID in the initial sequence.
913 */
914 {
915 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 916 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 917 }
918 return low + 1 + CHANNEL_NUMBER_OFFSET;
919}
920
9fab77dc 921static void c_write(Ssh ssh, const char *buf, int len)
32874aea 922{
67779be7 923 if ((flags & FLAG_STDERR)) {
32874aea 924 int i;
925 for (i = 0; i < len; i++)
926 if (buf[i] != '\r')
927 fputc(buf[i], stderr);
fb09bf1c 928 return;
929 }
51470298 930 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 931}
932
9fab77dc 933static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 934{
a209e957 935 int i;
936 for (i = 0; i < len; i++) {
32874aea 937 if (buf[i] == '\n')
51470298 938 c_write(ssh, "\r\n", 2);
32874aea 939 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 940 c_write(ssh, buf + i, 1);
a209e957 941 }
942}
943
9fab77dc 944static void c_write_str(Ssh ssh, const char *buf)
32874aea 945{
51470298 946 c_write(ssh, buf, strlen(buf));
1408a877 947}
948
ff3187f6 949static void ssh_free_packet(struct Packet *pkt)
950{
951 sfree(pkt->data);
952 sfree(pkt);
953}
954static struct Packet *ssh_new_packet(void)
955{
956 struct Packet *pkt = snew(struct Packet);
957
958 pkt->data = NULL;
959 pkt->maxlen = 0;
960 pkt->logmode = PKTLOG_EMIT;
961 pkt->nblanks = 0;
962 pkt->blanks = NULL;
963
964 return pkt;
965}
966
fb09bf1c 967/*
968 * Collect incoming data in the incoming packet buffer.
e5574168 969 * Decipher and verify the packet when it is completely read.
970 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 971 * Update the *data and *datalen variables.
ff3187f6 972 * Return a Packet structure when a packet is completed.
fb09bf1c 973 */
ff3187f6 974static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 975{
51470298 976 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 977
51470298 978 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 979
ff3187f6 980 st->pktin = ssh_new_packet();
981
982 st->pktin->type = 0;
983 st->pktin->length = 0;
374330e2 984
57476f6b 985 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 986 while ((*datalen) == 0)
ff3187f6 987 crReturn(NULL);
57476f6b 988 st->len = (st->len << 8) + **data;
fb09bf1c 989 (*data)++, (*datalen)--;
990 }
374330e2 991
57476f6b 992 st->pad = 8 - (st->len % 8);
993 st->biglen = st->len + st->pad;
ff3187f6 994 st->pktin->length = st->len - 5;
fb09bf1c 995
ae0500e5 996 if (st->biglen < 0) {
997 bombout(("Extremely large packet length from server suggests"
998 " data stream corruption"));
ff3187f6 999 ssh_free_packet(st->pktin);
1000 crStop(NULL);
ae0500e5 1001 }
1002
ff3187f6 1003 st->pktin->maxlen = st->biglen;
1004 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1005
57476f6b 1006 st->to_read = st->biglen;
ff3187f6 1007 st->p = st->pktin->data;
57476f6b 1008 while (st->to_read > 0) {
32874aea 1009 st->chunk = st->to_read;
fb09bf1c 1010 while ((*datalen) == 0)
ff3187f6 1011 crReturn(NULL);
57476f6b 1012 if (st->chunk > (*datalen))
1013 st->chunk = (*datalen);
1014 memcpy(st->p, *data, st->chunk);
1015 *data += st->chunk;
1016 *datalen -= st->chunk;
1017 st->p += st->chunk;
1018 st->to_read -= st->chunk;
fb09bf1c 1019 }
374330e2 1020
ff3187f6 1021 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1022 st->biglen, NULL)) {
6b5cf8b4 1023 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1024 ssh_free_packet(st->pktin);
1025 crStop(NULL);
9a3a93a5 1026 }
1027
51470298 1028 if (ssh->cipher)
ff3187f6 1029 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1030
ff3187f6 1031 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1032 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1033 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1034 bombout(("Incorrect CRC received on packet"));
ff3187f6 1035 ssh_free_packet(st->pktin);
1036 crStop(NULL);
fb09bf1c 1037 }
572f871e 1038
ff3187f6 1039 st->pktin->body = st->pktin->data + st->pad + 1;
1040 st->pktin->savedpos = 0;
4ba9b64b 1041
51470298 1042 if (ssh->v1_compressing) {
4ba9b64b 1043 unsigned char *decompblk;
1044 int decomplen;
36b8d9bb 1045 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1046 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1047 &decompblk, &decomplen)) {
1048 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1049 ssh_free_packet(st->pktin);
1050 crStop(NULL);
36b8d9bb 1051 }
4ba9b64b 1052
ff3187f6 1053 if (st->pktin->maxlen < st->pad + decomplen) {
1054 st->pktin->maxlen = st->pad + decomplen;
1055 st->pktin->data = sresize(st->pktin->data,
1056 st->pktin->maxlen + APIEXTRA,
3d88e64d 1057 unsigned char);
ff3187f6 1058 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1059 }
1060
ff3187f6 1061 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1062 sfree(decompblk);
ff3187f6 1063 st->pktin->length = decomplen - 1;
4ba9b64b 1064 }
1065
ff3187f6 1066 st->pktin->type = st->pktin->body[-1];
00db133f 1067
9a10ecf4 1068 /*
1069 * Log incoming packet, possibly omitting sensitive fields.
1070 */
1071 if (ssh->logctx) {
1072 int nblanks = 0;
1073 struct logblank_t blank;
1074 if (ssh->cfg.logomitdata) {
1075 int do_blank = FALSE, blank_prefix = 0;
1076 /* "Session data" packets - omit the data field */
ff3187f6 1077 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1078 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1079 do_blank = TRUE; blank_prefix = 0;
ff3187f6 1080 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
9a10ecf4 1081 do_blank = TRUE; blank_prefix = 4;
1082 }
1083 if (do_blank) {
1084 blank.offset = blank_prefix;
ff3187f6 1085 blank.len = st->pktin->length;
9a10ecf4 1086 blank.type = PKTLOG_OMIT;
1087 nblanks = 1;
1088 }
1089 }
a8327734 1090 log_packet(ssh->logctx,
ff3187f6 1091 PKT_INCOMING, st->pktin->type,
1092 ssh1_pkt_type(st->pktin->type),
1093 st->pktin->body, st->pktin->length,
9a10ecf4 1094 nblanks, &blank);
1095 }
00db133f 1096
ff3187f6 1097 crFinish(st->pktin);
fb09bf1c 1098}
1099
ff3187f6 1100static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1101{
51470298 1102 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1103
51470298 1104 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1105
ff3187f6 1106 st->pktin = ssh_new_packet();
1107
1108 st->pktin->type = 0;
1109 st->pktin->length = 0;
51470298 1110 if (ssh->sccipher)
1111 st->cipherblk = ssh->sccipher->blksize;
e5574168 1112 else
32874aea 1113 st->cipherblk = 8;
960e736a 1114 if (st->cipherblk < 8)
32874aea 1115 st->cipherblk = 8;
960e736a 1116
ff3187f6 1117 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1118
1119 /*
1120 * Acquire and decrypt the first block of the packet. This will
1121 * contain the length and padding details.
1122 */
32874aea 1123 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1124 while ((*datalen) == 0)
ff3187f6 1125 crReturn(NULL);
1126 st->pktin->data[st->i] = *(*data)++;
32874aea 1127 (*datalen)--;
e5574168 1128 }
4252c9cc 1129
51470298 1130 if (ssh->sccipher)
371e569c 1131 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1132 st->pktin->data, st->cipherblk);
e5574168 1133
1134 /*
1135 * Now get the length and padding figures.
1136 */
ff3187f6 1137 st->len = GET_32BIT(st->pktin->data);
1138 st->pad = st->pktin->data[4];
e5574168 1139
1140 /*
717dc483 1141 * _Completely_ silly lengths should be stomped on before they
1142 * do us any more damage.
1143 */
1144 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 1145 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1146 ssh_free_packet(st->pktin);
1147 crStop(NULL);
717dc483 1148 }
1149
1150 /*
e5574168 1151 * This enables us to deduce the payload length.
1152 */
960e736a 1153 st->payload = st->len - st->pad - 1;
e5574168 1154
ff3187f6 1155 st->pktin->length = st->payload + 5;
e5574168 1156
1157 /*
1158 * So now we can work out the total packet length.
1159 */
960e736a 1160 st->packetlen = st->len + 4;
51470298 1161 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1162
1163 /*
ff3187f6 1164 * Allocate memory for the rest of the packet.
e5574168 1165 */
ff3187f6 1166 st->pktin->maxlen = st->packetlen + st->maclen;
1167 st->pktin->data = sresize(st->pktin->data,
1168 st->pktin->maxlen + APIEXTRA,
1169 unsigned char);
e5574168 1170
1171 /*
1172 * Read and decrypt the remainder of the packet.
1173 */
32874aea 1174 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1175 st->i++) {
e5574168 1176 while ((*datalen) == 0)
ff3187f6 1177 crReturn(NULL);
1178 st->pktin->data[st->i] = *(*data)++;
32874aea 1179 (*datalen)--;
e5574168 1180 }
1181 /* Decrypt everything _except_ the MAC. */
51470298 1182 if (ssh->sccipher)
371e569c 1183 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1184 st->pktin->data + st->cipherblk,
51470298 1185 st->packetlen - st->cipherblk);
e5574168 1186
9442dd57 1187 st->pktin->encrypted_len = st->packetlen;
1188
e5574168 1189 /*
1190 * Check the MAC.
1191 */
51470298 1192 if (ssh->scmac
ff3187f6 1193 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1194 st->incoming_sequence)) {
6b5cf8b4 1195 bombout(("Incorrect MAC received on packet"));
ff3187f6 1196 ssh_free_packet(st->pktin);
1197 crStop(NULL);
8d5de777 1198 }
b09eaa88 1199
1200 st->pktin->sequence = st->incoming_sequence++;
e5574168 1201
4ba9b64b 1202 /*
1203 * Decompress packet payload.
1204 */
1205 {
1206 unsigned char *newpayload;
1207 int newlen;
51470298 1208 if (ssh->sccomp &&
5366aed8 1209 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1210 st->pktin->data + 5, st->pktin->length - 5,
51470298 1211 &newpayload, &newlen)) {
ff3187f6 1212 if (st->pktin->maxlen < newlen + 5) {
1213 st->pktin->maxlen = newlen + 5;
1214 st->pktin->data = sresize(st->pktin->data,
1215 st->pktin->maxlen + APIEXTRA,
3d88e64d 1216 unsigned char);
4ba9b64b 1217 }
ff3187f6 1218 st->pktin->length = 5 + newlen;
1219 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1220 sfree(newpayload);
4ba9b64b 1221 }
1222 }
1223
ff3187f6 1224 st->pktin->savedpos = 6;
1225 st->pktin->body = st->pktin->data;
1226 st->pktin->type = st->pktin->data[5];
e5574168 1227
9a10ecf4 1228 /*
1229 * Log incoming packet, possibly omitting sensitive fields.
1230 */
1231 if (ssh->logctx) {
1232 int nblanks = 0;
1233 struct logblank_t blank;
1234 if (ssh->cfg.logomitdata) {
1235 int do_blank = FALSE, blank_prefix = 0;
1236 /* "Session data" packets - omit the data field */
ff3187f6 1237 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1238 do_blank = TRUE; blank_prefix = 4;
ff3187f6 1239 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
9a10ecf4 1240 do_blank = TRUE; blank_prefix = 8;
1241 }
1242 if (do_blank) {
1243 blank.offset = blank_prefix;
ff3187f6 1244 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1245 blank.type = PKTLOG_OMIT;
1246 nblanks = 1;
1247 }
1248 }
ff3187f6 1249 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1250 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1251 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1252 nblanks, &blank);
1253 }
00db133f 1254
ff3187f6 1255 crFinish(st->pktin);
e5574168 1256}
1257
ff3187f6 1258static void ssh1_pktout_size(struct Packet *pkt, int len)
32874aea 1259{
374330e2 1260 int pad, biglen;
1261
1262 len += 5; /* type and CRC */
32874aea 1263 pad = 8 - (len % 8);
374330e2 1264 biglen = len + pad;
1265
ff3187f6 1266 pkt->length = len - 5;
1267 if (pkt->maxlen < biglen) {
1268 pkt->maxlen = biglen;
1269 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
374330e2 1270 }
ff3187f6 1271 pkt->body = pkt->data + 4 + pad + 1;
4ba9b64b 1272}
374330e2 1273
ff3187f6 1274static struct Packet *s_wrpkt_start(int type, int len)
32874aea 1275{
ff3187f6 1276 struct Packet *pkt = ssh_new_packet();
1277 ssh1_pktout_size(pkt, len);
1278 pkt->type = type;
9a10ecf4 1279 /* Initialise log omission state */
ff3187f6 1280 pkt->nblanks = 0;
1281 pkt->blanks = NULL;
1282 return pkt;
374330e2 1283}
1284
ff3187f6 1285static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
32874aea 1286{
fd7a4aad 1287 int pad, biglen, i;
374330e2 1288 unsigned long crc;
fd7a4aad 1289#ifdef __SC__
1290 /*
1291 * XXX various versions of SC (including 8.8.4) screw up the
1292 * register allocation in this function and use the same register
1293 * (D6) for len and as a temporary, with predictable results. The
1294 * following sledgehammer prevents this.
1295 */
1296 volatile
1297#endif
1298 int len;
374330e2 1299
ff3187f6 1300 pkt->body[-1] = pkt->type;
4ba9b64b 1301
a8327734 1302 if (ssh->logctx)
ff3187f6 1303 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1304 ssh1_pkt_type(pkt->type),
1305 pkt->body, pkt->length,
1306 pkt->nblanks, pkt->blanks);
1307 sfree(pkt->blanks); pkt->blanks = NULL;
1308 pkt->nblanks = 0;
00db133f 1309
51470298 1310 if (ssh->v1_compressing) {
4ba9b64b 1311 unsigned char *compblk;
1312 int complen;
5366aed8 1313 zlib_compress_block(ssh->cs_comp_ctx,
ff3187f6 1314 pkt->body - 1, pkt->length + 1,
4ba9b64b 1315 &compblk, &complen);
ff3187f6 1316 ssh1_pktout_size(pkt, complen - 1);
1317 memcpy(pkt->body - 1, compblk, complen);
dcbde236 1318 sfree(compblk);
4ba9b64b 1319 }
1320
ff3187f6 1321 len = pkt->length + 5; /* type and CRC */
32874aea 1322 pad = 8 - (len % 8);
374330e2 1323 biglen = len + pad;
1324
32874aea 1325 for (i = 0; i < pad; i++)
ff3187f6 1326 pkt->data[i + 4] = random_byte();
1327 crc = crc32_compute(pkt->data + 4, biglen - 4);
1328 PUT_32BIT(pkt->data + biglen, crc);
1329 PUT_32BIT(pkt->data, len);
374330e2 1330
51470298 1331 if (ssh->cipher)
ff3187f6 1332 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
374330e2 1333
32874aea 1334 return biglen + 4;
39065bed 1335}
1336
ff3187f6 1337static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1338{
5471d09a 1339 int len, backlog;
ff3187f6 1340 len = s_wrpkt_prepare(ssh, pkt);
1341 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1342 if (backlog > SSH_MAX_BACKLOG)
51470298 1343 ssh_throttle_all(ssh, 1, backlog);
39065bed 1344}
1345
ff3187f6 1346static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1347{
39065bed 1348 int len;
ff3187f6 1349 len = s_wrpkt_prepare(ssh, pkt);
51470298 1350 if (ssh->deferred_len + len > ssh->deferred_size) {
1351 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1352 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1353 ssh->deferred_size,
1354 unsigned char);
39065bed 1355 }
ff3187f6 1356 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1357 ssh->deferred_len += len;
374330e2 1358}
1359
fb09bf1c 1360/*
39065bed 1361 * Construct a packet with the specified contents.
fb09bf1c 1362 */
ff3187f6 1363static struct Packet *construct_packet(Ssh ssh, int pkttype,
1364 va_list ap1, va_list ap2)
fb09bf1c 1365{
fb09bf1c 1366 unsigned char *p, *argp, argchar;
1367 unsigned long argint;
1368 int pktlen, argtype, arglen;
7cca0d81 1369 Bignum bn;
ff3187f6 1370 struct Packet *pkt;
fb09bf1c 1371
1372 pktlen = 0;
39065bed 1373 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1374 switch (argtype) {
1375 case PKT_INT:
39065bed 1376 (void) va_arg(ap1, int);
fb09bf1c 1377 pktlen += 4;
1378 break;
1379 case PKT_CHAR:
1ec39246 1380 (void) va_arg(ap1, int);
fb09bf1c 1381 pktlen++;
1382 break;
1383 case PKT_DATA:
39065bed 1384 (void) va_arg(ap1, unsigned char *);
1385 arglen = va_arg(ap1, int);
fb09bf1c 1386 pktlen += arglen;
1387 break;
1388 case PKT_STR:
39065bed 1389 argp = va_arg(ap1, unsigned char *);
d8baa528 1390 arglen = strlen((char *)argp);
fb09bf1c 1391 pktlen += 4 + arglen;
1392 break;
7cca0d81 1393 case PKT_BIGNUM:
39065bed 1394 bn = va_arg(ap1, Bignum);
32874aea 1395 pktlen += ssh1_bignum_length(bn);
7cca0d81 1396 break;
9a10ecf4 1397 case PKTT_PASSWORD:
1398 case PKTT_DATA:
1399 case PKTT_OTHER:
1400 /* ignore this pass */
1401 break;
fb09bf1c 1402 default:
1403 assert(0);
1404 }
1405 }
fb09bf1c 1406
ff3187f6 1407 pkt = s_wrpkt_start(pkttype, pktlen);
1408 p = pkt->body;
fb09bf1c 1409
39065bed 1410 while ((argtype = va_arg(ap2, int)) != PKT_END) {
ff3187f6 1411 int offset = p - pkt->body, len = 0;
fb09bf1c 1412 switch (argtype) {
9a10ecf4 1413 /* Actual fields in the packet */
fb09bf1c 1414 case PKT_INT:
39065bed 1415 argint = va_arg(ap2, int);
fb09bf1c 1416 PUT_32BIT(p, argint);
9a10ecf4 1417 len = 4;
fb09bf1c 1418 break;
1419 case PKT_CHAR:
1ec39246 1420 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1421 *p = argchar;
9a10ecf4 1422 len = 1;
fb09bf1c 1423 break;
1424 case PKT_DATA:
39065bed 1425 argp = va_arg(ap2, unsigned char *);
1426 arglen = va_arg(ap2, int);
fb09bf1c 1427 memcpy(p, argp, arglen);
9a10ecf4 1428 len = arglen;
fb09bf1c 1429 break;
1430 case PKT_STR:
39065bed 1431 argp = va_arg(ap2, unsigned char *);
d8baa528 1432 arglen = strlen((char *)argp);
fb09bf1c 1433 PUT_32BIT(p, arglen);
1434 memcpy(p + 4, argp, arglen);
9a10ecf4 1435 len = arglen + 4;
fb09bf1c 1436 break;
7cca0d81 1437 case PKT_BIGNUM:
39065bed 1438 bn = va_arg(ap2, Bignum);
9a10ecf4 1439 len = ssh1_write_bignum(p, bn);
1440 break;
1441 /* Tokens for modifications to packet logging */
1442 case PKTT_PASSWORD:
ff3187f6 1443 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1444 break;
1445 case PKTT_DATA:
ff3187f6 1446 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1447 break;
9a10ecf4 1448 case PKTT_OTHER:
ff3187f6 1449 end_log_omission(ssh, pkt);
9a10ecf4 1450 break;
1451 }
1452 p += len;
1453 /* Deal with logfile omission, if required. */
ff3187f6 1454 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1455 pkt->nblanks++;
1456 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1457 struct logblank_t);
1458 pkt->blanks[pkt->nblanks-1].offset = offset;
1459 pkt->blanks[pkt->nblanks-1].len = len;
1460 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
fb09bf1c 1461 }
1462 }
ff3187f6 1463
1464 return pkt;
39065bed 1465}
fb09bf1c 1466
51470298 1467static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1468{
ff3187f6 1469 struct Packet *pkt;
39065bed 1470 va_list ap1, ap2;
1471 va_start(ap1, pkttype);
1472 va_start(ap2, pkttype);
ff3187f6 1473 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1474 va_end(ap2);
1475 va_end(ap1);
1476 s_wrpkt(ssh, pkt);
1477 ssh_free_packet(pkt);
fb09bf1c 1478}
1479
51470298 1480static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1481{
ff3187f6 1482 struct Packet *pkt;
39065bed 1483 va_list ap1, ap2;
1484 va_start(ap1, pkttype);
1485 va_start(ap2, pkttype);
ff3187f6 1486 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1487 va_end(ap2);
1488 va_end(ap1);
1489 s_wrpkt_defer(ssh, pkt);
1490 ssh_free_packet(pkt);
39065bed 1491}
1492
32874aea 1493static int ssh_versioncmp(char *a, char *b)
1494{
9697bfd2 1495 char *ae, *be;
1496 unsigned long av, bv;
1497
43aa02a7 1498 av = strtoul(a, &ae, 10);
1499 bv = strtoul(b, &be, 10);
32874aea 1500 if (av != bv)
1501 return (av < bv ? -1 : +1);
1502 if (*ae == '.')
1503 ae++;
1504 if (*be == '.')
1505 be++;
43aa02a7 1506 av = strtoul(ae, &ae, 10);
1507 bv = strtoul(be, &be, 10);
32874aea 1508 if (av != bv)
1509 return (av < bv ? -1 : +1);
9697bfd2 1510 return 0;
1511}
1512
e5574168 1513/*
a92dd380 1514 * Utility routines for putting an SSH-protocol `string' and
1515 * `uint32' into a SHA state.
e5574168 1516 */
1517#include <stdio.h>
32874aea 1518static void sha_string(SHA_State * s, void *str, int len)
1519{
e5574168 1520 unsigned char lenblk[4];
e5574168 1521 PUT_32BIT(lenblk, len);
e5574168 1522 SHA_Bytes(s, lenblk, 4);
e5574168 1523 SHA_Bytes(s, str, len);
1524}
1525
32874aea 1526static void sha_uint32(SHA_State * s, unsigned i)
1527{
a92dd380 1528 unsigned char intblk[4];
1529 PUT_32BIT(intblk, i);
1530 SHA_Bytes(s, intblk, 4);
1531}
1532
7cca0d81 1533/*
1534 * SSH2 packet construction functions.
1535 */
ff3187f6 1536static void ssh2_pkt_ensure(struct Packet *pkt, int length)
32874aea 1537{
ff3187f6 1538 if (pkt->maxlen < length) {
1539 pkt->maxlen = length + 256;
1540 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
7cca0d81 1541 }
783415f8 1542}
ff3187f6 1543static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1544{
ff3187f6 1545 if (pkt->logmode != PKTLOG_EMIT) {
1546 pkt->nblanks++;
1547 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1548 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1549 pkt->blanks[pkt->nblanks-1].len = len;
1550 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1551 }
1552 pkt->length += len;
1553 ssh2_pkt_ensure(pkt, pkt->length);
1554 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1555}
ff3187f6 1556static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1557{
ff3187f6 1558 ssh2_pkt_adddata(pkt, &byte, 1);
7cca0d81 1559}
ff3187f6 1560static struct Packet *ssh2_pkt_init(int pkt_type)
32874aea 1561{
ff3187f6 1562 struct Packet *pkt = ssh_new_packet();
1563 pkt->length = 5;
1564 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1565 return pkt;
7cca0d81 1566}
ff3187f6 1567static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1568{
ff3187f6 1569 ssh2_pkt_adddata(pkt, &value, 1);
7cca0d81 1570}
ff3187f6 1571static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1572{
7cca0d81 1573 unsigned char x[4];
1574 PUT_32BIT(x, value);
ff3187f6 1575 ssh2_pkt_adddata(pkt, x, 4);
7cca0d81 1576}
ff3187f6 1577static void ssh2_pkt_addstring_start(struct Packet *pkt)
32874aea 1578{
ff3187f6 1579 ssh2_pkt_adduint32(pkt, 0);
1580 pkt->savedpos = pkt->length;
7cca0d81 1581}
ff3187f6 1582static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1583{
ff3187f6 1584 ssh2_pkt_adddata(pkt, data, strlen(data));
1585 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1586}
ff3187f6 1587static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1588{
ff3187f6 1589 ssh2_pkt_adddata(pkt, data, len);
1590 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1591}
ff3187f6 1592static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
32874aea 1593{
ff3187f6 1594 ssh2_pkt_addstring_start(pkt);
1595 ssh2_pkt_addstring_str(pkt, data);
7cca0d81 1596}
d8baa528 1597static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1598{
7cca0d81 1599 unsigned char *p;
32874aea 1600 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1601 p = snewn(n + 1, unsigned char);
7cca0d81 1602 if (!p)
32874aea 1603 fatalbox("out of memory");
7cca0d81 1604 p[0] = 0;
3709bfe9 1605 for (i = 1; i <= n; i++)
32874aea 1606 p[i] = bignum_byte(b, n - i);
7cca0d81 1607 i = 0;
32874aea 1608 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1609 i++;
1610 memmove(p, p + i, n + 1 - i);
1611 *len = n + 1 - i;
7cca0d81 1612 return p;
1613}
ff3187f6 1614static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1615{
7cca0d81 1616 unsigned char *p;
1617 int len;
1618 p = ssh2_mpint_fmt(b, &len);
ff3187f6 1619 ssh2_pkt_addstring_start(pkt);
1620 ssh2_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1621 sfree(p);
7cca0d81 1622}
b185170a 1623
1624/*
1625 * Construct an SSH2 final-form packet: compress it, encrypt it,
1626 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1627 * pkt->data. Total length is returned.
b185170a 1628 */
ff3187f6 1629static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1630{
7cca0d81 1631 int cipherblk, maclen, padding, i;
7cca0d81 1632
a8327734 1633 if (ssh->logctx)
ff3187f6 1634 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1635 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1636 pkt->data + 6, pkt->length - 6,
1637 pkt->nblanks, pkt->blanks);
1638 sfree(pkt->blanks); pkt->blanks = NULL;
1639 pkt->nblanks = 0;
00db133f 1640
7cca0d81 1641 /*
4ba9b64b 1642 * Compress packet payload.
1643 */
4ba9b64b 1644 {
1645 unsigned char *newpayload;
1646 int newlen;
51470298 1647 if (ssh->cscomp &&
ff3187f6 1648 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1649 pkt->length - 5,
51470298 1650 &newpayload, &newlen)) {
ff3187f6 1651 pkt->length = 5;
1652 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1653 sfree(newpayload);
4ba9b64b 1654 }
1655 }
1656
1657 /*
7cca0d81 1658 * Add padding. At least four bytes, and must also bring total
1659 * length (minus MAC) up to a multiple of the block size.
1660 */
51470298 1661 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1662 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1663 padding = 4;
32874aea 1664 padding +=
ff3187f6 1665 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
51470298 1666 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1667 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1668 pkt->data[4] = padding;
7cca0d81 1669 for (i = 0; i < padding; i++)
ff3187f6 1670 pkt->data[pkt->length + i] = random_byte();
1671 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1672 if (ssh->csmac)
ff3187f6 1673 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1674 pkt->length + padding,
51470298 1675 ssh->v2_outgoing_sequence);
1676 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1677
1678 if (ssh->cscipher)
371e569c 1679 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1680 pkt->data, pkt->length + padding);
51470298 1681
9442dd57 1682 pkt->encrypted_len = pkt->length + padding;
1683
ff3187f6 1684 /* Ready-to-send packet starts at pkt->data. We return length. */
1685 return pkt->length + padding + maclen;
b185170a 1686}
1687
1688/*
590f6a5f 1689 * Routines called from the main SSH code to send packets. There
1690 * are quite a few of these, because we have two separate
1691 * mechanisms for delaying the sending of packets:
1692 *
1693 * - In order to send an IGNORE message and a password message in
1694 * a single fixed-length blob, we require the ability to
1695 * concatenate the encrypted forms of those two packets _into_ a
1696 * single blob and then pass it to our <network.h> transport
1697 * layer in one go. Hence, there's a deferment mechanism which
1698 * works after packet encryption.
1699 *
1700 * - In order to avoid sending any connection-layer messages
1701 * during repeat key exchange, we have to queue up any such
1702 * outgoing messages _before_ they are encrypted (and in
1703 * particular before they're allocated sequence numbers), and
1704 * then send them once we've finished.
1705 *
1706 * I call these mechanisms `defer' and `queue' respectively, so as
1707 * to distinguish them reasonably easily.
1708 *
1709 * The functions send_noqueue() and defer_noqueue() free the packet
1710 * structure they are passed. Every outgoing packet goes through
1711 * precisely one of these functions in its life; packets passed to
1712 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1713 * these or get queued, and then when the queue is later emptied
1714 * the packets are all passed to defer_noqueue().
b185170a 1715 */
590f6a5f 1716
1717/*
1718 * Send an SSH2 packet immediately, without queuing or deferring.
1719 */
1720static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1721{
5471d09a 1722 int len;
1723 int backlog;
ff3187f6 1724 len = ssh2_pkt_construct(ssh, pkt);
1725 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1726 if (backlog > SSH_MAX_BACKLOG)
51470298 1727 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1728
1729 ssh->outgoing_data_size += pkt->encrypted_len;
1730 if (!ssh->kex_in_progress &&
d57f70af 1731 ssh->max_data_size != 0 &&
1732 ssh->outgoing_data_size > ssh->max_data_size)
9442dd57 1733 do_ssh2_transport(ssh, "Initiating key re-exchange "
1734 "(too much data sent)", -1, NULL);
1735
ff3187f6 1736 ssh_free_packet(pkt);
b185170a 1737}
1738
1739/*
590f6a5f 1740 * Defer an SSH2 packet.
b185170a 1741 */
590f6a5f 1742static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1743{
ff3187f6 1744 int len = ssh2_pkt_construct(ssh, pkt);
51470298 1745 if (ssh->deferred_len + len > ssh->deferred_size) {
1746 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1747 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1748 ssh->deferred_size,
1749 unsigned char);
b185170a 1750 }
ff3187f6 1751 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1752 ssh->deferred_len += len;
9442dd57 1753 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1754 ssh_free_packet(pkt);
b185170a 1755}
1756
1757/*
590f6a5f 1758 * Queue an SSH2 packet.
1759 */
1760static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1761{
1762 assert(ssh->queueing);
1763
1764 if (ssh->queuelen >= ssh->queuesize) {
1765 ssh->queuesize = ssh->queuelen + 32;
1766 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1767 }
1768
1769 ssh->queue[ssh->queuelen++] = pkt;
1770}
1771
1772/*
1773 * Either queue or send a packet, depending on whether queueing is
1774 * set.
1775 */
1776static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1777{
1778 if (ssh->queueing)
1779 ssh2_pkt_queue(ssh, pkt);
1780 else
1781 ssh2_pkt_send_noqueue(ssh, pkt);
1782}
1783
1784/*
1785 * Either queue or defer a packet, depending on whether queueing is
1786 * set.
1787 */
1788static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1789{
1790 if (ssh->queueing)
1791 ssh2_pkt_queue(ssh, pkt);
1792 else
1793 ssh2_pkt_defer_noqueue(ssh, pkt);
1794}
1795
1796/*
b185170a 1797 * Send the whole deferred data block constructed by
39065bed 1798 * ssh2_pkt_defer() or SSH1's defer_packet().
590f6a5f 1799 *
1800 * The expected use of the defer mechanism is that you call
1801 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1802 * not currently queueing, this simply sets up deferred_send_data
1803 * and then sends it. If we _are_ currently queueing, the calls to
1804 * ssh2_pkt_defer() put the deferred packets on to the queue
1805 * instead, and therefore ssh_pkt_defersend() has no deferred data
1806 * to send. Hence, there's no need to make it conditional on
1807 * ssh->queueing.
b185170a 1808 */
51470298 1809static void ssh_pkt_defersend(Ssh ssh)
32874aea 1810{
5471d09a 1811 int backlog;
d8baa528 1812 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1813 ssh->deferred_len);
51470298 1814 ssh->deferred_len = ssh->deferred_size = 0;
1815 sfree(ssh->deferred_send_data);
1816 ssh->deferred_send_data = NULL;
5471d09a 1817 if (backlog > SSH_MAX_BACKLOG)
51470298 1818 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1819
1820 ssh->outgoing_data_size += ssh->deferred_data_size;
1821 if (!ssh->kex_in_progress &&
d57f70af 1822 ssh->max_data_size != 0 &&
1823 ssh->outgoing_data_size > ssh->max_data_size)
9442dd57 1824 do_ssh2_transport(ssh, "Initiating key re-exchange "
1825 "(too much data sent)", -1, NULL);
1826 ssh->deferred_data_size = 0;
7cca0d81 1827}
1828
590f6a5f 1829/*
1830 * Send all queued SSH2 packets. We send them by means of
1831 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1832 * packets that needed to be lumped together.
1833 */
1834static void ssh2_pkt_queuesend(Ssh ssh)
1835{
1836 int i;
1837
1838 assert(!ssh->queueing);
1839
1840 for (i = 0; i < ssh->queuelen; i++)
1841 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1842 ssh->queuelen = 0;
1843
1844 ssh_pkt_defersend(ssh);
1845}
1846
7cca0d81 1847#if 0
32874aea 1848void bndebug(char *string, Bignum b)
1849{
7cca0d81 1850 unsigned char *p;
1851 int i, len;
1852 p = ssh2_mpint_fmt(b, &len);
1853 debug(("%s", string));
1854 for (i = 0; i < len; i++)
32874aea 1855 debug((" %02x", p[i]));
765c4200 1856 debug(("\n"));
dcbde236 1857 sfree(p);
7cca0d81 1858}
1859#endif
1860
32874aea 1861static void sha_mpint(SHA_State * s, Bignum b)
1862{
7cca0d81 1863 unsigned char *p;
1864 int len;
1865 p = ssh2_mpint_fmt(b, &len);
1866 sha_string(s, p, len);
dcbde236 1867 sfree(p);
7cca0d81 1868}
1869
1870/*
0016d70b 1871 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1872 */
ff3187f6 1873static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1874{
7cca0d81 1875 unsigned long value;
ff3187f6 1876 if (pkt->length - pkt->savedpos < 4)
32874aea 1877 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1878 value = GET_32BIT(pkt->body + pkt->savedpos);
1879 pkt->savedpos += 4;
7cca0d81 1880 return value;
1881}
ff3187f6 1882static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1883{
65a22376 1884 unsigned long value;
ff3187f6 1885 if (pkt->length - pkt->savedpos < 1)
32874aea 1886 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1887 value = pkt->body[pkt->savedpos] != 0;
1888 pkt->savedpos++;
65a22376 1889 return value;
1890}
ff3187f6 1891static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 1892{
57356d63 1893 int len;
7cca0d81 1894 *p = NULL;
45068b27 1895 *length = 0;
ff3187f6 1896 if (pkt->length - pkt->savedpos < 4)
32874aea 1897 return;
ff3187f6 1898 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 1899 if (len < 0)
1900 return;
1901 *length = len;
ff3187f6 1902 pkt->savedpos += 4;
1903 if (pkt->length - pkt->savedpos < *length)
32874aea 1904 return;
ff3187f6 1905 *p = (char *)(pkt->body + pkt->savedpos);
1906 pkt->savedpos += *length;
7cca0d81 1907}
ff3187f6 1908static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 1909{
ff3187f6 1910 if (pkt->length - pkt->savedpos < length)
0016d70b 1911 return NULL;
ff3187f6 1912 pkt->savedpos += length;
1913 return pkt->body + (pkt->savedpos - length);
0016d70b 1914}
ff3187f6 1915static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 1916 unsigned char **keystr)
1917{
1918 int j;
1919
ff3187f6 1920 j = makekey(pkt->body + pkt->savedpos,
1921 pkt->length - pkt->savedpos,
0016d70b 1922 key, keystr, 0);
1923
1924 if (j < 0)
1925 return FALSE;
1926
ff3187f6 1927 pkt->savedpos += j;
1928 assert(pkt->savedpos < pkt->length);
0016d70b 1929
1930 return TRUE;
1931}
ff3187f6 1932static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 1933{
1934 int j;
1935 Bignum b;
1936
ff3187f6 1937 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1938 pkt->length - pkt->savedpos, &b);
0016d70b 1939
1940 if (j < 0)
1941 return NULL;
1942
ff3187f6 1943 pkt->savedpos += j;
0016d70b 1944 return b;
1945}
ff3187f6 1946static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 1947{
7cca0d81 1948 char *p;
3709bfe9 1949 int length;
7cca0d81 1950 Bignum b;
1951
ff3187f6 1952 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 1953 if (!p)
32874aea 1954 return NULL;
ff3187f6 1955 if (p[0] & 0x80)
32874aea 1956 return NULL;
d8baa528 1957 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1958 return b;
1959}
1960
7d503c31 1961/*
1dd353b5 1962 * Helper function to add an SSH2 signature blob to a packet.
1963 * Expects to be shown the public key blob as well as the signature
1964 * blob. Normally works just like ssh2_pkt_addstring, but will
1965 * fiddle with the signature packet if necessary for
1966 * BUG_SSH2_RSA_PADDING.
1967 */
ff3187f6 1968static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1969 void *pkblob_v, int pkblob_len,
1dd353b5 1970 void *sigblob_v, int sigblob_len)
1971{
1972 unsigned char *pkblob = (unsigned char *)pkblob_v;
1973 unsigned char *sigblob = (unsigned char *)sigblob_v;
1974
1975 /* dmemdump(pkblob, pkblob_len); */
1976 /* dmemdump(sigblob, sigblob_len); */
1977
1978 /*
1979 * See if this is in fact an ssh-rsa signature and a buggy
1980 * server; otherwise we can just do this the easy way.
1981 */
51470298 1982 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1983 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1984 int pos, len, siglen;
1985
1986 /*
1987 * Find the byte length of the modulus.
1988 */
1989
1990 pos = 4+7; /* skip over "ssh-rsa" */
1991 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1992 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1993 pos += 4; /* find modulus itself */
1994 while (len > 0 && pkblob[pos] == 0)
1995 len--, pos++;
1996 /* debug(("modulus length is %d\n", len)); */
1997
1998 /*
1999 * Now find the signature integer.
2000 */
2001 pos = 4+7; /* skip over "ssh-rsa" */
2002 siglen = GET_32BIT(sigblob+pos);
2003 /* debug(("signature length is %d\n", siglen)); */
2004
2005 if (len != siglen) {
2006 unsigned char newlen[4];
ff3187f6 2007 ssh2_pkt_addstring_start(pkt);
2008 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2009 /* dmemdump(sigblob, pos); */
2010 pos += 4; /* point to start of actual sig */
2011 PUT_32BIT(newlen, len);
ff3187f6 2012 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2013 /* dmemdump(newlen, 4); */
2014 newlen[0] = 0;
2015 while (len-- > siglen) {
ff3187f6 2016 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2017 /* dmemdump(newlen, 1); */
2018 }
ff3187f6 2019 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2020 /* dmemdump(sigblob+pos, siglen); */
2021 return;
2022 }
2023
2024 /* Otherwise fall through and do it the easy way. */
2025 }
2026
ff3187f6 2027 ssh2_pkt_addstring_start(pkt);
2028 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2029}
2030
2031/*
7d503c31 2032 * Examine the remote side's version string and compare it against
2033 * a list of known buggy implementations.
2034 */
51470298 2035static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2036{
2037 char *imp; /* pointer to implementation part */
7d503c31 2038 imp = vstring;
2039 imp += strcspn(imp, "-");
bd358db1 2040 if (*imp) imp++;
7d503c31 2041 imp += strcspn(imp, "-");
bd358db1 2042 if (*imp) imp++;
7d503c31 2043
51470298 2044 ssh->remote_bugs = 0;
7d503c31 2045
5ecd7ad0 2046 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2047 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 2048 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2049 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2050 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2051 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2052 /*
2053 * These versions don't support SSH1_MSG_IGNORE, so we have
2054 * to use a different defence against password length
2055 * sniffing.
2056 */
51470298 2057 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 2058 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 2059 }
2060
5ecd7ad0 2061 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2062 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 2063 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2064 /*
2065 * These versions need a plain password sent; they can't
2066 * handle having a null and a random length of data after
2067 * the password.
2068 */
51470298 2069 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 2070 logevent("We believe remote version needs a plain SSH1 password");
2071 }
2072
5ecd7ad0 2073 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2074 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2075 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2076 /*
2077 * These versions apparently have no clue whatever about
2078 * RSA authentication and will panic and die if they see
2079 * an AUTH_RSA message.
2080 */
51470298 2081 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 2082 logevent("We believe remote version can't handle RSA authentication");
2083 }
2084
5ecd7ad0 2085 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2086 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2087 !wc_match("* VShell", imp) &&
831301f6 2088 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2089 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2090 wc_match("2.1 *", imp)))) {
32874aea 2091 /*
2092 * These versions have the HMAC bug.
2093 */
51470298 2094 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2095 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2096 }
1dd353b5 2097
5ecd7ad0 2098 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2099 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2100 !wc_match("* VShell", imp) &&
2856a1b9 2101 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2102 /*
2103 * These versions have the key-derivation bug (failing to
2104 * include the literal shared secret in the hashes that
2105 * generate the keys).
2106 */
51470298 2107 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2108 logevent("We believe remote version has SSH2 key-derivation bug");
2109 }
2110
5ecd7ad0 2111 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2112 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2113 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2114 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2115 /*
2116 * These versions have the SSH2 RSA padding bug.
2117 */
51470298 2118 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2119 logevent("We believe remote version has SSH2 RSA padding bug");
2120 }
8e975795 2121
dda87a28 2122 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2123 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2124 wc_match("OpenSSH_2.[0-2]*", imp))) {
2125 /*
2126 * These versions have the SSH2 session-ID bug in
2127 * public-key authentication.
2128 */
2129 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2130 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2131 }
7d503c31 2132}
2133
d38d6a1f 2134/*
2135 * The `software version' part of an SSH version string is required
2136 * to contain no spaces or minus signs.
2137 */
2138static void ssh_fix_verstring(char *str)
2139{
2140 /* Eat "SSH-<protoversion>-". */
2141 assert(*str == 'S'); str++;
2142 assert(*str == 'S'); str++;
2143 assert(*str == 'H'); str++;
2144 assert(*str == '-'); str++;
2145 while (*str && *str != '-') str++;
2146 assert(*str == '-'); str++;
2147
2148 /* Convert minus signs and spaces in the remaining string into
2149 * underscores. */
2150 while (*str) {
2151 if (*str == '-' || *str == ' ')
2152 *str = '_';
2153 str++;
2154 }
2155}
2156
51470298 2157static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2158{
51470298 2159 struct do_ssh_init_state {
2160 int vslen;
2161 char version[10];
2162 char *vstring;
2163 int vstrsize;
2164 int i;
2165 int proto1, proto2;
2166 };
2167 crState(do_ssh_init_state);
374330e2 2168
51470298 2169 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2170
2171 /* Search for the string "SSH-" in the input. */
51470298 2172 s->i = 0;
8df7a775 2173 while (1) {
2174 static const int transS[] = { 1, 2, 2, 1 };
2175 static const int transH[] = { 0, 0, 3, 0 };
2176 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2177 if (c == 'S')
51470298 2178 s->i = transS[s->i];
32874aea 2179 else if (c == 'H')
51470298 2180 s->i = transH[s->i];
32874aea 2181 else if (c == '-')
51470298 2182 s->i = transminus[s->i];
32874aea 2183 else
51470298 2184 s->i = 0;
2185 if (s->i < 0)
8df7a775 2186 break;
2187 crReturn(1); /* get another character */
374330e2 2188 }
8df7a775 2189
51470298 2190 s->vstrsize = 16;
3d88e64d 2191 s->vstring = snewn(s->vstrsize, char);
51470298 2192 strcpy(s->vstring, "SSH-");
2193 s->vslen = 4;
2194 s->i = 0;
374330e2 2195 while (1) {
8df7a775 2196 crReturn(1); /* get another char */
51470298 2197 if (s->vslen >= s->vstrsize - 1) {
2198 s->vstrsize += 16;
3d88e64d 2199 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2200 }
51470298 2201 s->vstring[s->vslen++] = c;
2202 if (s->i >= 0) {
374330e2 2203 if (c == '-') {
51470298 2204 s->version[s->i] = '\0';
2205 s->i = -1;
2206 } else if (s->i < sizeof(s->version) - 1)
2207 s->version[s->i++] = c;
c4ffc4d0 2208 } else if (c == '\012')
374330e2 2209 break;
2210 }
2211
51470298 2212 ssh->agentfwd_enabled = FALSE;
2213 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2214
51470298 2215 s->vstring[s->vslen] = 0;
a7d4653a 2216 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
51470298 2217 {
2218 char *vlog;
3d88e64d 2219 vlog = snewn(20 + s->vslen, char);
51470298 2220 sprintf(vlog, "Server version: %s", s->vstring);
2221 logevent(vlog);
2222 sfree(vlog);
2223 }
2224 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2225
adf799dd 2226 /*
38d228a2 2227 * Decide which SSH protocol version to support.
adf799dd 2228 */
38d228a2 2229
2230 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2231 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2232 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2233 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2234
86916870 2235 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2236 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2237 crStop(0);
38d228a2 2238 }
86916870 2239 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2240 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2241 crStop(0);
38d228a2 2242 }
2243
d38d6a1f 2244 {
2245 char *verstring;
2246
2247 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2248 /*
2249 * Construct a v2 version string.
2250 */
a7d4653a 2251 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
d38d6a1f 2252 ssh->version = 2;
2253 } else {
2254 /*
2255 * Construct a v1 version string.
2256 */
a7d4653a 2257 verstring = dupprintf("SSH-%s-%s\012",
d38d6a1f 2258 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2259 s->version : "1.5"),
2260 sshver);
2261 ssh->version = 1;
2262 }
2263
2264 ssh_fix_verstring(verstring);
2265
2266 if (ssh->version == 2) {
2267 /*
2268 * Hash our version string and their version string.
2269 */
2270 SHA_Init(&ssh->exhashbase);
0b351b6b 2271 sha_string(&ssh->exhashbase, verstring,
a7d4653a 2272 strcspn(verstring, "\015\012"));
0b351b6b 2273 sha_string(&ssh->exhashbase, s->vstring,
a7d4653a 2274 strcspn(s->vstring, "\015\012"));
d38d6a1f 2275
2276 /*
2277 * Initialise SSHv2 protocol.
2278 */
2279 ssh->protocol = ssh2_protocol;
2280 ssh2_protocol_setup(ssh);
2281 ssh->s_rdpkt = ssh2_rdpkt;
2282 } else {
2283 /*
2284 * Initialise SSHv1 protocol.
2285 */
2286 ssh->protocol = ssh1_protocol;
2287 ssh1_protocol_setup(ssh);
2288 ssh->s_rdpkt = ssh1_rdpkt;
2289 }
2290 logeventf(ssh, "We claim version: %.*s",
a7d4653a 2291 strcspn(verstring, "\015\012"), verstring);
51470298 2292 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2293 sfree(verstring);
e5574168 2294 }
d38d6a1f 2295
2296 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2297
125105d1 2298 update_specials_menu(ssh->frontend);
51470298 2299 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2300 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2301
51470298 2302 sfree(s->vstring);
50526e47 2303
8df7a775 2304 crFinish(0);
2305}
2306
51470298 2307static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2308{
51470298 2309 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2310
2311 /*
2312 * To begin with, feed the characters one by one to the
2313 * protocol initialisation / selection function do_ssh_init().
2314 * When that returns 0, we're done with the initial greeting
2315 * exchange and can move on to packet discipline.
2316 */
2317 while (1) {
51470298 2318 int ret; /* need not be kept across crReturn */
8df7a775 2319 if (datalen == 0)
2320 crReturnV; /* more data please */
51470298 2321 ret = do_ssh_init(ssh, *data);
32874aea 2322 data++;
2323 datalen--;
8df7a775 2324 if (ret == 0)
2325 break;
2326 }
2327
2328 /*
2329 * We emerge from that loop when the initial negotiation is
2330 * over and we have selected an s_rdpkt function. Now pass
2331 * everything to s_rdpkt, and then pass the resulting packets
2332 * to the proper protocol handler.
2333 */
2334 if (datalen == 0)
2335 crReturnV;
2336 while (1) {
2337 while (datalen > 0) {
ff3187f6 2338 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2339 if (pktin) {
2340 ssh->protocol(ssh, NULL, 0, pktin);
2341 ssh_free_packet(pktin);
8df7a775 2342 }
ff3187f6 2343 if (ssh->state == SSH_STATE_CLOSED)
2344 return;
8df7a775 2345 }
2346 crReturnV;
2347 }
2348 crFinishV;
2349}
2350
36f94d1f 2351static void ssh_do_close(Ssh ssh)
32874aea 2352{
36f94d1f 2353 int i;
2354 struct ssh_channel *c;
2355
51470298 2356 ssh->state = SSH_STATE_CLOSED;
2357 if (ssh->s) {
2358 sk_close(ssh->s);
2359 ssh->s = NULL;
39934deb 2360 notify_remote_exit(ssh->frontend);
f3ab576e 2361 }
36f94d1f 2362 /*
2363 * Now we must shut down any port and X forwardings going
2364 * through this connection.
2365 */
74a98066 2366 if (ssh->channels) {
2367 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2368 switch (c->type) {
2369 case CHAN_X11:
2370 x11_close(c->u.x11.s);
2371 break;
2372 case CHAN_SOCKDATA:
2373 pfd_close(c->u.pfd.s);
2374 break;
2375 }
2376 del234(ssh->channels, c);
2377 if (ssh->version == 2)
2378 bufchain_clear(&c->v.v2.outbuffer);
2379 sfree(c);
36f94d1f 2380 }
36f94d1f 2381 }
2382}
2383
cbe2d68f 2384static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2385 int calling_back)
2386{
2387 Ssh ssh = (Ssh) plug;
2388 ssh_do_close(ssh);
7e78000d 2389 if (error_msg) {
32874aea 2390 /* A socket error has occurred. */
247308b5 2391 logevent(error_msg);
971bcc0a 2392 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2393 } else {
2394 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2395 }
7e78000d 2396 return 0;
2397}
2398
32874aea 2399static int ssh_receive(Plug plug, int urgent, char *data, int len)
2400{
51470298 2401 Ssh ssh = (Ssh) plug;
d8baa528 2402 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2403 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2404 ssh_do_close(ssh);
32874aea 2405 return 0;
3257deae 2406 }
fef97f43 2407 return 1;
374330e2 2408}
2409
5471d09a 2410static void ssh_sent(Plug plug, int bufsize)
2411{
51470298 2412 Ssh ssh = (Ssh) plug;
5471d09a 2413 /*
2414 * If the send backlog on the SSH socket itself clears, we
2415 * should unthrottle the whole world if it was throttled.
2416 */
2417 if (bufsize < SSH_MAX_BACKLOG)
51470298 2418 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2419}
2420
fb09bf1c 2421/*
8df7a775 2422 * Connect to specified host and port.
2423 * Returns an error message, or NULL on success.
6e1ebb76 2424 * Also places the canonical host name into `realhost'. It must be
2425 * freed by the caller.
8df7a775 2426 */
cbe2d68f 2427static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2428 char **realhost, int nodelay, int keepalive)
8df7a775 2429{
51470298 2430 static const struct plug_function_table fn_table = {
7e78000d 2431 ssh_closing,
5471d09a 2432 ssh_receive,
2433 ssh_sent,
2434 NULL
51470298 2435 };
7e78000d 2436
8df7a775 2437 SockAddr addr;
cbe2d68f 2438 const char *err;
8df7a775 2439
3d88e64d 2440 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2441 if (!ssh->savedhost)
8df7a775 2442 fatalbox("Out of memory");
51470298 2443 strcpy(ssh->savedhost, host);
8df7a775 2444
2445 if (port < 0)
2446 port = 22; /* default ssh port */
51470298 2447 ssh->savedport = port;
8df7a775 2448
2449 /*
2450 * Try to find host.
2451 */
57356d63 2452 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2453 addr = name_lookup(host, port, realhost, &ssh->cfg);
170c1e6e 2454 if ((err = sk_addr_error(addr)) != NULL) {
2455 sk_addr_free(addr);
8df7a775 2456 return err;
170c1e6e 2457 }
8df7a775 2458
8df7a775 2459 /*
2460 * Open socket.
2461 */
3ad9d396 2462 {
57356d63 2463 char addrbuf[100];
3ad9d396 2464 sk_getaddr(addr, addrbuf, 100);
57356d63 2465 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2466 }
51470298 2467 ssh->fn = &fn_table;
e8fa8f62 2468 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2469 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2470 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2471 ssh->s = NULL;
39934deb 2472 notify_remote_exit(ssh->frontend);
8df7a775 2473 return err;
67c4ba2e 2474 }
8df7a775 2475
8df7a775 2476 return NULL;
2477}
2478
2479/*
5471d09a 2480 * Throttle or unthrottle the SSH connection.
2481 */
51470298 2482static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2483{
51470298 2484 int old_count = ssh->v1_throttle_count;
2485 ssh->v1_throttle_count += adjust;
2486 assert(ssh->v1_throttle_count >= 0);
2487 if (ssh->v1_throttle_count && !old_count) {
2488 sk_set_frozen(ssh->s, 1);
2489 } else if (!ssh->v1_throttle_count && old_count) {
2490 sk_set_frozen(ssh->s, 0);
5471d09a 2491 }
2492}
2493
2494/*
2495 * Throttle or unthrottle _all_ local data streams (for when sends
2496 * on the SSH connection itself back up).
2497 */
51470298 2498static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2499{
2500 int i;
2501 struct ssh_channel *c;
2502
51470298 2503 if (enable == ssh->throttled_all)
5471d09a 2504 return;
51470298 2505 ssh->throttled_all = enable;
2506 ssh->overall_bufsize = bufsize;
2507 if (!ssh->channels)
5471d09a 2508 return;
51470298 2509 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2510 switch (c->type) {
2511 case CHAN_MAINSESSION:
2512 /*
2513 * This is treated separately, outside the switch.
2514 */
2515 break;
2516 case CHAN_X11:
2517 x11_override_throttle(c->u.x11.s, enable);
2518 break;
2519 case CHAN_AGENT:
2520 /* Agent channels require no buffer management. */
2521 break;
2522 case CHAN_SOCKDATA:
36f94d1f 2523 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2524 break;
2525 }
2526 }
2527}
2528
2529/*
51470298 2530 * Username and password input, abstracted off into routines
2531 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2532 */
0405e71f 2533
2534/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2535static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2536{
51470298 2537 ssh->userpass_input_buffer = buffer;
2538 ssh->userpass_input_buflen = buflen;
2539 ssh->userpass_input_bufpos = 0;
2540 ssh->userpass_input_echo = echo;
0405e71f 2541}
2542
2543/*
2544 * Process some terminal data in the course of username/password
2545 * input. Returns >0 for success (line of input returned in
2546 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2547 * for inconclusive (keep waiting for more input please).
2548 */
ae9ae89f 2549static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2550{
2551 char c;
2552
2553 while (inlen--) {
2554 switch (c = *in++) {
2555 case 10:
2556 case 13:
51470298 2557 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2558 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2559 return +1;
2560 break;
2561 case 8:
2562 case 127:
51470298 2563 if (ssh->userpass_input_bufpos > 0) {
2564 if (ssh->userpass_input_echo)
2565 c_write_str(ssh, "\b \b");
2566 ssh->userpass_input_bufpos--;
0405e71f 2567 }
2568 break;
2569 case 21:
2570 case 27:
51470298 2571 while (ssh->userpass_input_bufpos > 0) {
2572 if (ssh->userpass_input_echo)
2573 c_write_str(ssh, "\b \b");
2574 ssh->userpass_input_bufpos--;
0405e71f 2575 }
2576 break;
2577 case 3:
2578 case 4:
2579 return -1;
2580 break;
2581 default:
4692a14a 2582 /*
2583 * This simplistic check for printability is disabled
2584 * when we're doing password input, because some people
2585 * have control characters in their passwords.o
2586 */
2587 if ((!ssh->userpass_input_echo ||
2588 (c >= ' ' && c <= '~') ||
0405e71f 2589 ((unsigned char) c >= 160))
51470298 2590 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2591 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2592 if (ssh->userpass_input_echo)
2593 c_write(ssh, &c, 1);
0405e71f 2594 }
2595 break;
2596 }
2597 }
2598 return 0;
2599}
2600
f11d78f2 2601static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2602{
2603 Ssh ssh = (Ssh) sshv;
2604
2605 ssh->agent_response = reply;
2606 ssh->agent_response_len = replylen;
2607
2608 if (ssh->version == 1)
ff3187f6 2609 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2610 else
ff3187f6 2611 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2612}
2613
f11d78f2 2614static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2615{
2616 struct ssh_channel *c = (struct ssh_channel *)cv;
2617 Ssh ssh = c->ssh;
2618 void *sentreply = reply;
2619
2620 if (!sentreply) {
2621 /* Fake SSH_AGENT_FAILURE. */
2622 sentreply = "\0\0\0\1\5";
2623 replylen = 5;
2624 }
2625 if (ssh->version == 2) {
2626 ssh2_add_channel_data(c, sentreply, replylen);
2627 ssh2_try_send(c);
2628 } else {
2629 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2630 PKT_INT, c->remoteid,
9a10ecf4 2631 PKTT_DATA,
839f10db 2632 PKT_INT, replylen,
2633 PKT_DATA, sentreply, replylen,
9a10ecf4 2634 PKTT_OTHER,
839f10db 2635 PKT_END);
2636 }
2637 if (reply)
2638 sfree(reply);
2639}
2640
0405e71f 2641/*
fb09bf1c 2642 * Handle the key exchange and user authentication phases.
2643 */
ff3187f6 2644static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2645 struct Packet *pktin)
fb09bf1c 2646{
0016d70b 2647 int i, j, ret;
2648 unsigned char cookie[8], *ptr;
374330e2 2649 struct RSAKey servkey, hostkey;
2650 struct MD5Context md5c;
51470298 2651 struct do_ssh1_login_state {
2652 int len;
2653 unsigned char *rsabuf, *keystr1, *keystr2;
2654 unsigned long supported_ciphers_mask, supported_auths_mask;
2655 int tried_publickey, tried_agent;
2656 int tis_auth_refused, ccard_auth_refused;
2657 unsigned char session_id[16];
2658 int cipher_type;
2659 char username[100];
2660 void *publickey_blob;
2661 int publickey_bloblen;
2662 char password[100];
2663 char prompt[200];
2664 int pos;
2665 char c;
2666 int pwpkt_type;
2667 unsigned char request[5], *response, *p;
2668 int responselen;
2669 int keyi, nkeys;
2670 int authed;
2671 struct RSAKey key;
2672 Bignum challenge;
2673 char *commentp;
2674 int commentlen;
2675 };
2676 crState(do_ssh1_login_state);
2677
2678 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2679
ff3187f6 2680 if (!pktin)
2681 crWaitUntil(pktin);
374330e2 2682
ff3187f6 2683 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2684 bombout(("Public key packet not received"));
7ffdbc1a 2685 crStop(0);
8d5de777 2686 }
374330e2 2687
c5e9c988 2688 logevent("Received public keys");
374330e2 2689
ff3187f6 2690 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2691 if (!ptr) {
2692 bombout(("SSH1 public key packet stopped before random cookie"));
2693 crStop(0);
2694 }
2695 memcpy(cookie, ptr, 8);
374330e2 2696
ff3187f6 2697 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2698 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2699 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2700 crStop(0);
2701 }
374330e2 2702
c5e9c988 2703 /*
1c2a93c4 2704 * Log the host key fingerprint.
c5e9c988 2705 */
c5e9c988 2706 {
2707 char logmsg[80];
1c2a93c4 2708 logevent("Host key fingerprint is:");
c5e9c988 2709 strcpy(logmsg, " ");
32874aea 2710 hostkey.comment = NULL;
2711 rsa_fingerprint(logmsg + strlen(logmsg),
2712 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2713 logevent(logmsg);
2714 }
2715
ff3187f6 2716 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2717 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2718 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2719
51470298 2720 ssh->v1_local_protoflags =
2721 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2722 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2723
c5e9c988 2724 MD5Init(&md5c);
51470298 2725 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2726 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2727 MD5Update(&md5c, cookie, 8);
51470298 2728 MD5Final(s->session_id, &md5c);
374330e2 2729
32874aea 2730 for (i = 0; i < 32; i++)
51470298 2731 ssh->session_key[i] = random_byte();
374330e2 2732
0016d70b 2733 /*
2734 * Verify that the `bits' and `bytes' parameters match.
2735 */
2736 if (hostkey.bits > hostkey.bytes * 8 ||
2737 servkey.bits > servkey.bytes * 8) {
2738 bombout(("SSH1 public keys were badly formatted"));
2739 crStop(0);
2740 }
2741
51470298 2742 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2743
3d88e64d 2744 s->rsabuf = snewn(s->len, unsigned char);
51470298 2745 if (!s->rsabuf)
374330e2 2746 fatalbox("Out of memory");
2747
89ee5268 2748 /*
2749 * Verify the host key.
2750 */
2751 {
32874aea 2752 /*
2753 * First format the key into a string.
2754 */
2755 int len = rsastr_len(&hostkey);
2756 char fingerprint[100];
3d88e64d 2757 char *keystr = snewn(len, char);
32874aea 2758 if (!keystr)
2759 fatalbox("Out of memory");
2760 rsastr_fmt(keystr, &hostkey);
2761 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2762 verify_ssh_host_key(ssh->frontend,
2763 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2764 fingerprint);
2765 sfree(keystr);
2766 }
2767
2768 for (i = 0; i < 32; i++) {
51470298 2769 s->rsabuf[i] = ssh->session_key[i];
374330e2 2770 if (i < 16)
51470298 2771 s->rsabuf[i] ^= s->session_id[i];
374330e2 2772 }
2773
2774 if (hostkey.bytes > servkey.bytes) {
0016d70b 2775 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2776 if (ret)
2777 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2778 } else {
0016d70b 2779 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2780 if (ret)
2781 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2782 }
2783 if (!ret) {
2784 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2785 crStop(0);
374330e2 2786 }
2787
c5e9c988 2788 logevent("Encrypted session key");
2789
ca20bfcf 2790 {
2791 int cipher_chosen = 0, warn = 0;
2792 char *cipher_string = NULL;
51470298 2793 int i;
ca20bfcf 2794 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2795 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2796 if (next_cipher == CIPHER_WARN) {
2797 /* If/when we choose a cipher, warn about it */
2798 warn = 1;
2799 } else if (next_cipher == CIPHER_AES) {
2800 /* XXX Probably don't need to mention this. */
2801 logevent("AES not supported in SSH1, skipping");
2802 } else {
2803 switch (next_cipher) {
51470298 2804 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2805 cipher_string = "3DES"; break;
51470298 2806 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2807 cipher_string = "Blowfish"; break;
51470298 2808 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2809 cipher_string = "single-DES"; break;
2810 }
51470298 2811 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2812 cipher_chosen = 1;
2813 }
2814 }
2815 if (!cipher_chosen) {
51470298 2816 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2817 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2818 "supporting 3DES encryption"));
2819 else
2820 /* shouldn't happen */
6b5cf8b4 2821 bombout(("No supported ciphers found"));
7ffdbc1a 2822 crStop(0);
a99a05c0 2823 }
ca20bfcf 2824
2825 /* Warn about chosen cipher if necessary. */
2826 if (warn)
83e7d008 2827 askalg(ssh->frontend, "cipher", cipher_string);
bea1ef5f 2828 }
ca20bfcf 2829
51470298 2830 switch (s->cipher_type) {
32874aea 2831 case SSH_CIPHER_3DES:
2832 logevent("Using 3DES encryption");
2833 break;
2834 case SSH_CIPHER_DES:
2835 logevent("Using single-DES encryption");
2836 break;
2837 case SSH_CIPHER_BLOWFISH:
2838 logevent("Using Blowfish encryption");
2839 break;
c5e9c988 2840 }
bea1ef5f 2841
51470298 2842 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2843 PKT_CHAR, s->cipher_type,
32874aea 2844 PKT_DATA, cookie, 8,
51470298 2845 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2846 PKT_DATA, s->rsabuf, s->len,
2847 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2848
c5e9c988 2849 logevent("Trying to enable encryption...");
374330e2 2850
51470298 2851 sfree(s->rsabuf);
374330e2 2852
51470298 2853 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2854 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2855 &ssh_3des);
371e569c 2856 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2857 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2858 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2859
0183b242 2860 ssh->crcda_ctx = crcda_make_context();
2861 logevent("Installing CRC compensation attack detector");
2862
679539d7 2863 if (servkey.modulus) {
2864 sfree(servkey.modulus);
2865 servkey.modulus = NULL;
2866 }
2867 if (servkey.exponent) {
2868 sfree(servkey.exponent);
2869 servkey.exponent = NULL;
2870 }
2871 if (hostkey.modulus) {
2872 sfree(hostkey.modulus);
2873 hostkey.modulus = NULL;
2874 }
2875 if (hostkey.exponent) {
2876 sfree(hostkey.exponent);
2877 hostkey.exponent = NULL;
2878 }
ff3187f6 2879 crWaitUntil(pktin);
374330e2 2880
ff3187f6 2881 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2882 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2883 crStop(0);
8d5de777 2884 }
374330e2 2885
c5e9c988 2886 logevent("Successfully started encryption");
2887
374330e2 2888 fflush(stdout);
2889 {
aa09f7d0 2890 if (!*ssh->cfg.username) {
c0a81592 2891 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2892 if (!ssh_get_line("login as: ",
51470298 2893 s->username, sizeof(s->username), FALSE)) {
32874aea 2894 /*
2895 * get_line failed to get a username.
2896 * Terminate.
2897 */
2898 logevent("No username provided. Abandoning session.");
3bb2f322 2899 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2900 crStop(1);
32874aea 2901 }
2902 } else {
51470298 2903 int ret; /* need not be kept over crReturn */
2904 c_write_str(ssh, "login as: ");
2905 ssh->send_ok = 1;
0405e71f 2906
51470298 2907 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2908 do {
ff3187f6 2909 crWaitUntil(!pktin);
51470298 2910 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2911 } while (ret == 0);
2912 if (ret < 0)
2913 cleanup_exit(0);
51470298 2914 c_write_str(ssh, "\r\n");
32874aea 2915 }
2916 } else {
86916870 2917 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2918 s->username[sizeof(s->username)-1] = '\0';
374330e2 2919 }
fb09bf1c 2920
51470298 2921 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2922 {
51470298 2923 char userlog[22 + sizeof(s->username)];
2924 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2925 logevent(userlog);
32874aea 2926 if (flags & FLAG_INTERACTIVE &&
2927 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2928 strcat(userlog, "\r\n");
51470298 2929 c_write_str(ssh, userlog);
3c8e959b 2930 }
c5e9c988 2931 }
374330e2 2932 }
2933
ff3187f6 2934 crWaitUntil(pktin);
374330e2 2935
51470298 2936 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2937 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2938 s->tried_publickey = s->tried_agent = 1;
0df73905 2939 } else {
51470298 2940 s->tried_publickey = s->tried_agent = 0;
0df73905 2941 }
51470298 2942 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2943 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2944 if (!filename_is_null(ssh->cfg.keyfile)) {
2945 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2946 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2947 s->publickey_blob = NULL;
396778f1 2948 } else
51470298 2949 s->publickey_blob = NULL;
7cca0d81 2950
ff3187f6 2951 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 2952 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2953
51470298 2954 if (agent_exists() && !s->tried_agent) {
32874aea 2955 /*
2956 * Attempt RSA authentication using Pageant.
2957 */
32874aea 2958 void *r;
2959
51470298 2960 s->authed = FALSE;
2961 s->tried_agent = 1;
32874aea 2962 logevent("Pageant is running. Requesting keys.");
2963
2964 /* Request the keys held by the agent. */
51470298 2965 PUT_32BIT(s->request, 1);
2966 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2967 if (!agent_query(s->request, 5, &r, &s->responselen,
2968 ssh_agent_callback, ssh)) {
2969 do {
2970 crReturn(0);
ff3187f6 2971 if (pktin) {
839f10db 2972 bombout(("Unexpected data from server while waiting"
2973 " for agent response"));
2974 crStop(0);
2975 }
ff3187f6 2976 } while (pktin || inlen > 0);
839f10db 2977 r = ssh->agent_response;
2978 s->responselen = ssh->agent_response_len;
2979 }
51470298 2980 s->response = (unsigned char *) r;
2981 if (s->response && s->responselen >= 5 &&
2982 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2983 s->p = s->response + 5;
2984 s->nkeys = GET_32BIT(s->p);
2985 s->p += 4;
32874aea 2986 {
2987 char buf[64];
51470298 2988 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2989 logevent(buf);
2990 }
51470298 2991 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2992 {
2993 char buf[64];
51470298 2994 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2995 logevent(buf);
2996 }
51470298 2997 if (s->publickey_blob &&
2998 !memcmp(s->p, s->publickey_blob,
2999 s->publickey_bloblen)) {
396778f1 3000 logevent("This key matches configured key file");
51470298 3001 s->tried_publickey = 1;
396778f1 3002 }
51470298 3003 s->p += 4;
0016d70b 3004 {
3005 int n, ok = FALSE;
3006 do { /* do while (0) to make breaking easy */
3007 n = ssh1_read_bignum
3008 (s->p, s->responselen-(s->p-s->response),
3009 &s->key.exponent);
3010 if (n < 0)
3011 break;
3012 s->p += n;
3013 n = ssh1_read_bignum
3014 (s->p, s->responselen-(s->p-s->response),
3015 &s->key.modulus);
3016 if (n < 0)
3017 break;
3018 s->p += n;
3019 if (s->responselen - (s->p-s->response) < 4)
3020 break;
3021 s->commentlen = GET_32BIT(s->p);
3022 s->p += 4;
3023 if (s->responselen - (s->p-s->response) <
3024 s->commentlen)
3025 break;
3026 s->commentp = (char *)s->p;
3027 s->p += s->commentlen;
3028 ok = TRUE;
3029 } while (0);
3030 if (!ok) {
3031 logevent("Pageant key list packet was truncated");
3032 break;
3033 }
3034 }
51470298 3035 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3036 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3037 crWaitUntil(pktin);
3038 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3039 logevent("Key refused");
3040 continue;
3041 }
3042 logevent("Received RSA challenge");
ff3187f6 3043 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3044 bombout(("Server's RSA challenge was badly formatted"));
3045 crStop(0);
3046 }
3047
32874aea 3048 {
3049 char *agentreq, *q, *ret;
2d466ffd 3050 void *vret;
32874aea 3051 int len, retlen;
3052 len = 1 + 4; /* message type, bit count */
51470298 3053 len += ssh1_bignum_length(s->key.exponent);
3054 len += ssh1_bignum_length(s->key.modulus);
3055 len += ssh1_bignum_length(s->challenge);
32874aea 3056 len += 16; /* session id */
3057 len += 4; /* response format */
3d88e64d 3058 agentreq = snewn(4 + len, char);
32874aea 3059 PUT_32BIT(agentreq, len);
3060 q = agentreq + 4;
3061 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3062 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3063 q += 4;
51470298 3064 q += ssh1_write_bignum(q, s->key.exponent);
3065 q += ssh1_write_bignum(q, s->key.modulus);
3066 q += ssh1_write_bignum(q, s->challenge);
3067 memcpy(q, s->session_id, 16);
32874aea 3068 q += 16;
3069 PUT_32BIT(q, 1); /* response format */
839f10db 3070 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3071 ssh_agent_callback, ssh)) {
3072 sfree(agentreq);
3073 do {
3074 crReturn(0);
ff3187f6 3075 if (pktin) {
839f10db 3076 bombout(("Unexpected data from server"
3077 " while waiting for agent"
3078 " response"));
3079 crStop(0);
3080 }
ff3187f6 3081 } while (pktin || inlen > 0);
839f10db 3082 vret = ssh->agent_response;
3083 retlen = ssh->agent_response_len;
3084 } else
3085 sfree(agentreq);
2d466ffd 3086 ret = vret;
32874aea 3087 if (ret) {
3088 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3089 logevent("Sending Pageant's response");
51470298 3090 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3091 PKT_DATA, ret + 5, 16,
3092 PKT_END);
3093 sfree(ret);
ff3187f6 3094 crWaitUntil(pktin);
3095 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3096 logevent
3097 ("Pageant's response accepted");
3098 if (flags & FLAG_VERBOSE) {
51470298 3099 c_write_str(ssh, "Authenticated using"
3100 " RSA key \"");
3101 c_write(ssh, s->commentp,
3102 s->commentlen);
3103 c_write_str(ssh, "\" from agent\r\n");
32874aea 3104 }
51470298 3105 s->authed = TRUE;
32874aea 3106 } else
3107 logevent
3108 ("Pageant's response not accepted");
3109 } else {
3110 logevent
3111 ("Pageant failed to answer challenge");
3112 sfree(ret);
3113 }
3114 } else {
3115 logevent("No reply received from Pageant");
3116 }
3117 }
51470298 3118 freebn(s->key.exponent);
3119 freebn(s->key.modulus);
3120 freebn(s->challenge);
3121 if (s->authed)
32874aea 3122 break;
3123 }
29b1d0b3 3124 sfree(s->response);
32874aea 3125 }
51470298 3126 if (s->authed)
32874aea 3127 break;
3128 }
9a30e26b 3129 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3130 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3131
86916870 3132 if (ssh->cfg.try_tis_auth &&
51470298 3133 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3134 !s->tis_auth_refused) {
3135 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3136 logevent("Requested TIS authentication");
51470298 3137 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3138 crWaitUntil(pktin);
3139 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3140 logevent("TIS authentication declined");
3141 if (flags & FLAG_INTERACTIVE)
51470298 3142 c_write_str(ssh, "TIS authentication refused.\r\n");
3143 s->tis_auth_refused = 1;
614a20a0 3144 continue;
32874aea 3145 } else {
0016d70b 3146 char *challenge;
3147 int challengelen;
3148
ff3187f6 3149 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3150 if (!challenge) {
3151 bombout(("TIS challenge packet was badly formed"));
3152 crStop(0);
3153 }
32874aea 3154 logevent("Received TIS challenge");
51470298 3155 if (challengelen > sizeof(s->prompt) - 1)
3156 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3157 memcpy(s->prompt, challenge, challengelen);
614a20a0 3158 /* Prompt heuristic comes from OpenSSH */
51470298 3159 strncpy(s->prompt + challengelen,
3160 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3161 "": "\r\nResponse: ",
51470298 3162 (sizeof s->prompt) - challengelen);
3163 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3164 }
3165 }
86916870 3166 if (ssh->cfg.try_tis_auth &&
51470298 3167 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3168 !s->ccard_auth_refused) {
3169 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3170 logevent("Requested CryptoCard authentication");
51470298 3171 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3172 crWaitUntil(pktin);
3173 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3174 logevent("CryptoCard authentication declined");
51470298 3175 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3176 s->ccard_auth_refused = 1;
614a20a0 3177 continue;
32874aea 3178 } else {
0016d70b 3179 char *challenge;
3180 int challengelen;
3181
ff3187f6 3182 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3183 if (!challenge) {
3184 bombout(("CryptoCard challenge packet was badly formed"));
3185 crStop(0);
3186 }
32874aea 3187 logevent("Received CryptoCard challenge");
51470298 3188 if (challengelen > sizeof(s->prompt) - 1)
3189 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3190 memcpy(s->prompt, challenge, challengelen);
51470298 3191 strncpy(s->prompt + challengelen,
3192 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3193 "" : "\r\nResponse: ",
51470298 3194 sizeof(s->prompt) - challengelen);
3195 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3196 }
3197 }
51470298 3198 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3199 sprintf(s->prompt, "%.90s@%.90s's password: ",
3200 s->username, ssh->savedhost);
32874aea 3201 }
51470298 3202 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3203 char *comment = NULL;
231ee168 3204 int type;
3205 char msgbuf[256];
32874aea 3206 if (flags & FLAG_VERBOSE)
51470298 3207 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3208 logeventf(ssh, "Trying public key \"%s\"",
3209 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3210 type = key_type(&ssh->cfg.keyfile);
231ee168 3211 if (type != SSH_KEYTYPE_SSH1) {
3212 sprintf(msgbuf, "Key is of wrong type (%s)",
3213 key_type_to_str(type));
3214 logevent(msgbuf);
51470298 3215 c_write_str(ssh, msgbuf);
3216 c_write_str(ssh, "\r\n");
3217 s->tried_publickey = 1;
231ee168 3218 continue;
3219 }
9a30e26b 3220 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3221 if (flags & FLAG_VERBOSE)
51470298 3222 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3223 goto tryauth;
3224 }
51470298 3225 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3226 sfree(comment);
3227 }
a52f067e 3228
614a20a0 3229 /*
3230 * Show password prompt, having first obtained it via a TIS
3231 * or CryptoCard exchange if we're doing TIS or CryptoCard
3232 * authentication.
3233 */
fa17a66e 3234 if (ssh_get_line) {
51470298 3235 if (!ssh_get_line(s->prompt, s->password,
3236 sizeof(s->password), TRUE)) {
32874aea 3237 /*
3238 * get_line failed to get a password (for example
3239 * because one was supplied on the command line
3240 * which has already failed to work). Terminate.
3241 */
51470298 3242 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3243 PKT_STR, "No more passwords available to try",
3244 PKT_END);
247308b5 3245 logevent("Unable to authenticate");
a8327734 3246 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3247 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3248 crStop(1);
32874aea 3249 }
fb09bf1c 3250 } else {
614a20a0 3251 /* Prompt may have come from server. We've munged it a bit, so
3252 * we know it to be zero-terminated at least once. */
51470298 3253 int ret; /* need not be saved over crReturn */
3254 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3255 s->pos = 0;
0405e71f 3256
51470298 3257 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3258 do {
ff3187f6 3259 crWaitUntil(!pktin);
51470298 3260 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3261 } while (ret == 0);
3262 if (ret < 0)
3263 cleanup_exit(0);
51470298 3264 c_write_str(ssh, "\r\n");
32874aea 3265 }
3266
3267 tryauth:
51470298 3268 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3269 /*
3270 * Try public key authentication with the specified
3271 * key file.
3272 */
51470298 3273 s->tried_publickey = 1;
3274
3275 {
222d54dc 3276 const char *error = NULL;
3277 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3278 &error);
51470298 3279 if (ret == 0) {
3280 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3281 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3282 c_write_str(ssh, " (");
3283 c_write_str(ssh, error);
3284 c_write_str(ssh, ").\r\n");
51470298 3285 continue; /* go and try password */
3286 }
3287 if (ret == -1) {
3288 c_write_str(ssh, "Wrong passphrase.\r\n");
3289 s->tried_publickey = 0;
3290 continue; /* try again */
3291 }
32874aea 3292 }
3293
3294 /*
3295 * Send a public key attempt.
3296 */
51470298 3297 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3298 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3299
ff3187f6 3300 crWaitUntil(pktin);
3301 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3302 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3303 continue; /* go and try password */
3304 }
ff3187f6 3305 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3306 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3307 crStop(0);
32874aea 3308 }
32874aea 3309
51470298 3310 {
3311 int i;
3312 unsigned char buffer[32];
3313 Bignum challenge, response;
3314
ff3187f6 3315 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3316 bombout(("Server's RSA challenge was badly formatted"));
3317 crStop(0);
3318 }
51470298 3319 response = rsadecrypt(challenge, &s->key);
3320 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3321
51470298 3322 for (i = 0; i < 32; i++) {
3323 buffer[i] = bignum_byte(response, 31 - i);
3324 }
3325
3326 MD5Init(&md5c);
3327 MD5Update(&md5c, buffer, 32);
3328 MD5Update(&md5c, s->session_id, 16);
3329 MD5Final(buffer, &md5c);
32874aea 3330
51470298 3331 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3332 PKT_DATA, buffer, 16, PKT_END);
3333
3334 freebn(challenge);
3335 freebn(response);
3336 }
32874aea 3337
ff3187f6 3338 crWaitUntil(pktin);
3339 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3340 if (flags & FLAG_VERBOSE)
51470298 3341 c_write_str(ssh, "Failed to authenticate with"
3342 " our public key.\r\n");
32874aea 3343 continue; /* go and try password */
ff3187f6 3344 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3345 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3346 crStop(0);
32874aea 3347 }
3348
3349 break; /* we're through! */
3350 } else {
51470298 3351 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3352 /*
3353 * Defence against traffic analysis: we send a
3354 * whole bunch of packets containing strings of
3355 * different lengths. One of these strings is the
3356 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3357 * The others are all random data in
3358 * SSH1_MSG_IGNORE packets. This way a passive
3359 * listener can't tell which is the password, and
3360 * hence can't deduce the password length.
3361 *
3362 * Anybody with a password length greater than 16
3363 * bytes is going to have enough entropy in their
3364 * password that a listener won't find it _that_
3365 * much help to know how long it is. So what we'll
3366 * do is:
3367 *
3368 * - if password length < 16, we send 15 packets
3369 * containing string lengths 1 through 15
3370 *
3371 * - otherwise, we let N be the nearest multiple
3372 * of 8 below the password length, and send 8
3373 * packets containing string lengths N through
3374 * N+7. This won't obscure the order of
3375 * magnitude of the password length, but it will
3376 * introduce a bit of extra uncertainty.
3377 *
3378 * A few servers (the old 1.2.18 through 1.2.22)
3379 * can't deal with SSH1_MSG_IGNORE. For these
3380 * servers, we need an alternative defence. We make
3381 * use of the fact that the password is interpreted
3382 * as a C string: so we can append a NUL, then some
3383 * random data.
bd358db1 3384 *
3385 * One server (a Cisco one) can deal with neither
3386 * SSH1_MSG_IGNORE _nor_ a padded password string.
3387 * For this server we are left with no defences
3388 * against password length sniffing.
32874aea 3389 */
51470298 3390 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3391 /*
3392 * The server can deal with SSH1_MSG_IGNORE, so
3393 * we can use the primary defence.
3394 */
32874aea 3395 int bottom, top, pwlen, i;
3396 char *randomstr;
3397
51470298 3398 pwlen = strlen(s->password);
32874aea 3399 if (pwlen < 16) {
3400 bottom = 0; /* zero length passwords are OK! :-) */
3401 top = 15;
3402 } else {
3403 bottom = pwlen & ~7;
3404 top = bottom + 7;
3405 }
3406
3407 assert(pwlen >= bottom && pwlen <= top);
3408
3d88e64d 3409 randomstr = snewn(top + 1, char);
32874aea 3410
3411 for (i = bottom; i <= top; i++) {
9a10ecf4 3412 if (i == pwlen) {
51470298 3413 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3414 PKTT_PASSWORD, PKT_STR, s->password,
3415 PKTT_OTHER, PKT_END);
3416 } else {
32874aea 3417 for (j = 0; j < i; j++) {
3418 do {
3419 randomstr[j] = random_byte();
3420 } while (randomstr[j] == '\0');
3421 }
3422 randomstr[i] = '\0';
51470298 3423 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3424 PKT_STR, randomstr, PKT_END);
3425 }
3426 }
bd358db1 3427 logevent("Sending password with camouflage packets");
51470298 3428 ssh_pkt_defersend(ssh);
679539d7 3429 sfree(randomstr);
bd358db1 3430 }
51470298 3431 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3432 /*
3433 * The server can't deal with SSH1_MSG_IGNORE
3434 * but can deal with padded passwords, so we
3435 * can use the secondary defence.
3436 */
bd358db1 3437 char string[64];
51470298 3438 char *ss;
bd358db1 3439 int len;
3440
51470298 3441 len = strlen(s->password);
bd358db1 3442 if (len < sizeof(string)) {
51470298 3443 ss = string;
3444 strcpy(string, s->password);
bd358db1 3445 len++; /* cover the zero byte */
3446 while (len < sizeof(string)) {
3447 string[len++] = (char) random_byte();
3448 }
3449 } else {
51470298 3450 ss = s->password;
bd358db1 3451 }
3452 logevent("Sending length-padded password");
9a10ecf4 3453 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3454 PKT_INT, len, PKT_DATA, ss, len,
3455 PKTT_OTHER, PKT_END);
bd358db1 3456 } else {
3457 /*
3458 * The server has _both_
3459 * BUG_CHOKES_ON_SSH1_IGNORE and
3460 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3461 * therefore nothing we can do.
3462 */
3463 int len;
51470298 3464 len = strlen(s->password);
bd358db1 3465 logevent("Sending unpadded password");
9a10ecf4 3466 send_packet(ssh, s->pwpkt_type,
3467 PKTT_PASSWORD, PKT_INT, len,
3468 PKT_DATA, s->password, len,
3469 PKTT_OTHER, PKT_END);
32874aea 3470 }
3471 } else {
9a10ecf4 3472 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3473 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3474 }
3475 }
c5e9c988 3476 logevent("Sent password");
51470298 3477 memset(s->password, 0, strlen(s->password));
ff3187f6 3478 crWaitUntil(pktin);
3479 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3480 if (flags & FLAG_VERBOSE)
51470298 3481 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3482 logevent("Authentication refused");
ff3187f6 3483 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3484 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3485 crStop(0);
374330e2 3486 }
3487 }
3488
c5e9c988 3489 logevent("Authentication successful");
3490
fb09bf1c 3491 crFinish(1);
3492}
3493
32874aea 3494void sshfwd_close(struct ssh_channel *c)
3495{
51470298 3496 Ssh ssh = c->ssh;
3497
36f94d1f 3498 if (ssh->state != SSH_STATE_SESSION) {
3499 assert(ssh->state == SSH_STATE_CLOSED);
3500 return;
3501 }
3502
80e48603 3503 if (c && !c->closes) {
4ed34d25 3504 /*
3505 * If the channel's remoteid is -1, we have sent
3506 * CHANNEL_OPEN for this channel, but it hasn't even been
3507 * acknowledged by the server. So we must set a close flag
3508 * on it now, and then when the server acks the channel
3509 * open, we can close it then.
3510 */
36cac739 3511 if (((int)c->remoteid) != -1) {
51470298 3512 if (ssh->version == 1) {
3513 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3514 PKT_END);
3515 } else {
ff3187f6 3516 struct Packet *pktout;
3517 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3518 ssh2_pkt_adduint32(pktout, c->remoteid);
3519 ssh2_pkt_send(ssh, pktout);
4ed34d25 3520 }
32874aea 3521 }
0357890f 3522 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3523 if (c->type == CHAN_X11) {
3524 c->u.x11.s = NULL;
d74d141c 3525 logevent("Forwarded X11 connection terminated");
4ed34d25 3526 } else if (c->type == CHAN_SOCKDATA ||
3527 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3528 c->u.pfd.s = NULL;
3529 logevent("Forwarded port closed");
32874aea 3530 }
3531 }
3532}
3533
5471d09a 3534int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3535{
51470298 3536 Ssh ssh = c->ssh;
3537
36f94d1f 3538 if (ssh->state != SSH_STATE_SESSION) {
3539 assert(ssh->state == SSH_STATE_CLOSED);
3540 return 0;
3541 }
3542
51470298 3543 if (ssh->version == 1) {
3544 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3545 PKT_INT, c->remoteid,
9a10ecf4 3546 PKTT_DATA,
3547 PKT_INT, len, PKT_DATA, buf, len,
3548 PKTT_OTHER, PKT_END);
5471d09a 3549 /*
3550 * In SSH1 we can return 0 here - implying that forwarded
3551 * connections are never individually throttled - because
3552 * the only circumstance that can cause throttling will be
3553 * the whole SSH connection backing up, in which case
3554 * _everything_ will be throttled as a whole.
3555 */
3556 return 0;
783415f8 3557 } else {
32874aea 3558 ssh2_add_channel_data(c, buf, len);
5471d09a 3559 return ssh2_try_send(c);
3560 }
3561}
3562
3563void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3564{
51470298 3565 Ssh ssh = c->ssh;
3566
36f94d1f 3567 if (ssh->state != SSH_STATE_SESSION) {
3568 assert(ssh->state == SSH_STATE_CLOSED);
3569 return;
3570 }
3571
51470298 3572 if (ssh->version == 1) {
5471d09a 3573 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3574 c->v.v1.throttling = 0;
51470298 3575 ssh1_throttle(ssh, -1);
5471d09a 3576 }
3577 } else {
3578 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3579 }
9c964e85 3580}
3581
06fadff5 3582static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3583{
3584 struct queued_handler *qh = ssh->qhead;
3585
3586 assert(qh != NULL);
3587
3588 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3589
3590 if (qh->msg1 > 0) {
3591 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3592 ssh->packet_dispatch[qh->msg1] = NULL;
3593 }
3594 if (qh->msg2 > 0) {
3595 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3596 ssh->packet_dispatch[qh->msg2] = NULL;
3597 }
3598
3599 if (qh->next) {
3600 ssh->qhead = qh->next;
3601
3602 if (ssh->qhead->msg1 > 0) {
3603 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3604 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3605 }
3606 if (ssh->qhead->msg2 > 0) {
3607 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3608 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3609 }
3610 } else {
3611 ssh->qhead = ssh->qtail = NULL;
3612 ssh->packet_dispatch[pktin->type] = NULL;
3613 }
3614
3615 qh->handler(ssh, pktin, qh->ctx);
3616
3617 sfree(qh);
3618}
3619
3620static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3621 chandler_fn_t handler, void *ctx)
3622{
3623 struct queued_handler *qh;
3624
3625 qh = snew(struct queued_handler);
3626 qh->msg1 = msg1;
3627 qh->msg2 = msg2;
3628 qh->handler = handler;
3629 qh->ctx = ctx;
3630 qh->next = NULL;
3631
3632 if (ssh->qtail == NULL) {
3633 ssh->qhead = qh;
3634
3635 if (qh->msg1 > 0) {
3636 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3637 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3638 }
3639 if (qh->msg2 > 0) {
3640 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3641 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3642 }
3643 } else {
3644 ssh->qtail->next = qh;
3645 }
3646 ssh->qtail = qh;
3647}
3648
3649static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3650{
3651 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3652
3653 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3654 SSH2_MSG_REQUEST_SUCCESS)) {
3655 logeventf(ssh, "Remote port forwarding from %s enabled",
3656 pf->sportdesc);
3657 } else {
3658 logeventf(ssh, "Remote port forwarding from %s refused",
3659 pf->sportdesc);
3660
3661 rpf = del234(ssh->rportfwds, pf);
3662 assert(rpf == pf);
fda2feb1 3663 free_rportfwd(pf);
06fadff5 3664 }
3665}
3666
3667static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3668{
3669 char type;
3670 int n;
3671 int sport,dport,sserv,dserv;
3672 char sports[256], dports[256], saddr[256], host[256];
3673 const char *portfwd_strptr;
3674
3675 portfwd_strptr = cfg->portfwd;
3676
fda2feb1 3677 if (!ssh->portfwds) {
3678 ssh->portfwds = newtree234(ssh_portcmp);
3679 } else {
3680 /*
3681 * Go through the existing port forwardings and tag them
3682 * with keep==FALSE. Any that we want to keep will be
3683 * re-enabled as we go through the configuration and find
3684 * out which bits are the same as they were before.
3685 */
3686 struct ssh_portfwd *epf;
3687 int i;
3688 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3689 epf->keep = FALSE;
3690 }
3691
06fadff5 3692 while (*portfwd_strptr) {
3693 type = *portfwd_strptr++;
3694 saddr[0] = '\0';
3695 n = 0;
3696 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3697 if (*portfwd_strptr == ':') {
3698 /*
3699 * We've seen a colon in the middle of the
3700 * source port number. This means that
3701 * everything we've seen until now is the
3702 * source _address_, so we'll move it into
3703 * saddr and start sports from the beginning
3704 * again.
3705 */
3706 portfwd_strptr++;
3707 sports[n] = '\0';
3708 if (ssh->version == 1 && type == 'R') {
3709 logeventf(ssh, "SSH1 cannot handle remote source address "
3710 "spec \"%s\"; ignoring", sports);
3711 } else
3712 strcpy(saddr, sports);
3713 n = 0;
3714 }
3715 if (n < 255) sports[n++] = *portfwd_strptr++;
3716 }
3717 sports[n] = 0;
3718 if (type != 'D') {
3719 if (*portfwd_strptr == '\t')
3720 portfwd_strptr++;
3721 n = 0;
3722 while (*portfwd_strptr && *portfwd_strptr != ':') {
3723 if (n < 255) host[n++] = *portfwd_strptr++;
3724 }
3725 host[n] = 0;
3726 if (*portfwd_strptr == ':')
3727 portfwd_strptr++;
3728 n = 0;
3729 while (*portfwd_strptr) {
3730 if (n < 255) dports[n++] = *portfwd_strptr++;
3731 }
3732 dports[n] = 0;
3733 portfwd_strptr++;
3734 dport = atoi(dports);
3735 dserv = 0;
3736 if (dport == 0) {
3737 dserv = 1;
3738 dport = net_service_lookup(dports);
3739 if (!dport) {
3740 logeventf(ssh, "Service lookup failed for destination"
3741 " port \"%s\"", dports);
3742 }
3743 }
3744 } else {
3745 while (*portfwd_strptr) portfwd_strptr++;
3746 dport = dserv = -1;
3747 portfwd_strptr++; /* eat the NUL and move to next one */
3748 }
3749 sport = atoi(sports);
3750 sserv = 0;
3751 if (sport == 0) {
3752 sserv = 1;
3753 sport = net_service_lookup(sports);
3754 if (!sport) {
3755 logeventf(ssh, "Service lookup failed for source"
3756 " port \"%s\"", sports);
3757 }
3758 }
3759 if (sport && dport) {
3760 /* Set up a description of the source port. */
fda2feb1 3761 struct ssh_portfwd *pfrec, *epfrec;
3762 char *sportdesc;
06fadff5 3763 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
3764 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3765 (int)(*saddr?1:0), ":",
3766 (int)(sserv ? strlen(sports) : 0), sports,
3767 sserv, "(", sport, sserv, ")");
fda2feb1 3768
3769 pfrec = snew(struct ssh_portfwd);
3770 pfrec->type = type;
3771 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3772 pfrec->sport = sport;
3773 pfrec->daddr = dupstr(host);
3774 pfrec->dport = dport;
3775 pfrec->local = NULL;
3776 pfrec->remote = NULL;
3777
3778 epfrec = add234(ssh->portfwds, pfrec);
3779 if (epfrec != pfrec) {
3780 /*
3781 * We already have a port forwarding with precisely
3782 * these parameters. Hence, no need to do anything;
3783 * simply tag the existing one as `keep'.
3784 */
3785 epfrec->keep = TRUE;
3786 free_portfwd(pfrec);
3787 } else if (type == 'L') {
06fadff5 3788 /* Verbose description of the destination port */
3789 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3790 host,
3791 (int)(dserv ? strlen(dports) : 0), dports,
3792 dserv, "(", dport, dserv, ")");
3793 const char *err = pfd_addforward(host, dport,
3794 *saddr ? saddr : NULL,
fda2feb1 3795 sport, ssh, &ssh->cfg,
3796 &pfrec->local);
06fadff5 3797 if (err) {
3798 logeventf(ssh, "Local port %s forward to %s"
3799 " failed: %s", sportdesc, dportdesc, err);
3800 } else {
3801 logeventf(ssh, "Local port %s forwarding to %s",
3802 sportdesc, dportdesc);
3803 }
3804 sfree(dportdesc);
3805 } else if (type == 'D') {
3806 const char *err = pfd_addforward(NULL, -1,
3807 *saddr ? saddr : NULL,
fda2feb1 3808 sport, ssh, &ssh->cfg,
3809 &pfrec->local);
06fadff5 3810 if (err) {
3811 logeventf(ssh, "Local port %s SOCKS dynamic forward"
3812 " setup failed: %s", sportdesc, err);
3813 } else {
3814 logeventf(ssh, "Local port %s doing SOCKS"
3815 " dynamic forwarding", sportdesc);
3816 }
3817 } else {
3818 struct ssh_rportfwd *pf;
3819
3820 /*
3821 * Ensure the remote port forwardings tree exists.
3822 */
3823 if (!ssh->rportfwds) {
3824 if (ssh->version == 1)
3825 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3826 else
3827 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3828 }
3829
3830 pf = snew(struct ssh_rportfwd);
3831 strcpy(pf->dhost, host);
3832 pf->dport = dport;
3833 pf->sport = sport;
3834 if (add234(ssh->rportfwds, pf) != pf) {
3835 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
3836 host, dport);
3837 sfree(pf);
3838 } else {
3839 logeventf(ssh, "Requesting remote port %s"
3840 " forward to %s:%.*s%.*s%d%.*s",
3841 sportdesc, host,
3842 (int)(dserv ? strlen(dports) : 0), dports,
3843 dserv, "(", dport, dserv, ")");
3844
3845 pf->sportdesc = sportdesc;
3846 sportdesc = NULL;
fda2feb1 3847 pfrec->remote = pf;
3848 pf->pfrec = pfrec;
06fadff5 3849
3850 if (ssh->version == 1) {
3851 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3852 PKT_INT, sport,
3853 PKT_STR, host,
3854 PKT_INT, dport,
3855 PKT_END);
3856 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
3857 SSH1_SMSG_FAILURE,
3858 ssh_rportfwd_succfail, pf);
3859 } else {
3860 struct Packet *pktout;
3861 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3862 ssh2_pkt_addstring(pktout, "tcpip-forward");
3863 ssh2_pkt_addbool(pktout, 1);/* want reply */
3864 if (*saddr) {
3865 ssh2_pkt_addstring(pktout, saddr);
3866 } else if (ssh->cfg.rport_acceptall) {
3867 ssh2_pkt_addstring(pktout, "0.0.0.0");
3868 } else {
3869 ssh2_pkt_addstring(pktout, "127.0.0.1");
3870 }
3871 ssh2_pkt_adduint32(pktout, sport);
3872 ssh2_pkt_send(ssh, pktout);
3873
3874 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
3875 SSH2_MSG_REQUEST_FAILURE,
3876 ssh_rportfwd_succfail, pf);
3877 }
3878 }
3879 }
3880 sfree(sportdesc);
3881 }
3882 }
fda2feb1 3883
3884 /*
3885 * Now go through and destroy any port forwardings which were
3886 * not re-enabled.
3887 */
3888 {
3889 struct ssh_portfwd *epf;
3890 int i;
3891 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3892 if (!epf->keep) {
3893 char *message;
3894
3895 message = dupprintf("%s port forwarding from %s%s%d",
3896 epf->type == 'L' ? "local" :
3897 epf->type == 'R' ? "remote" : "dynamic",
3898 epf->saddr ? epf->saddr : "",
3899 epf->saddr ? ":" : "",
3900 epf->sport);
3901
3902 if (epf->type != 'D') {
3903 char *msg2 = dupprintf("%s to %s:%d", message,
3904 epf->daddr, epf->dport);
3905 sfree(message);
3906 message = msg2;
3907 }
3908
3909 logeventf(ssh, "Cancelling %s", message);
3910 sfree(message);
3911
3912 if (epf->remote) {
3913 struct ssh_rportfwd *rpf = epf->remote;
3914 struct Packet *pktout;
3915
3916 /*
3917 * Cancel the port forwarding at the server
3918 * end.
3919 */
3920 if (ssh->version == 1) {
3921 /*
3922 * We cannot cancel listening ports on the
3923 * server side in SSH1! There's no message
3924 * to support it. Instead, we simply remove
3925 * the rportfwd record from the local end
3926 * so that any connections the server tries
3927 * to make on it are rejected.
3928 */
3929 } else {
3930 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3931 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3932 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3933 if (epf->saddr) {
3934 ssh2_pkt_addstring(pktout, epf->saddr);
3935 } else if (ssh->cfg.rport_acceptall) {
3936 ssh2_pkt_addstring(pktout, "0.0.0.0");
3937 } else {
3938 ssh2_pkt_addstring(pktout, "127.0.0.1");
3939 }
3940 ssh2_pkt_adduint32(pktout, epf->sport);
3941 ssh2_pkt_send(ssh, pktout);
3942 }
3943
3944 del234(ssh->rportfwds, rpf);
3945 free_rportfwd(rpf);
3946 } else if (epf->local) {
3947 pfd_terminate(epf->local);
3948 }
3949
3950 delpos234(ssh->portfwds, i);
3951 free_portfwd(epf);
3952 i--; /* so we don't skip one in the list */
3953 }
3954 }
06fadff5 3955}
3956
51df0ab5 3957static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
3958{
3959 char *string;
3960 int stringlen, bufsize;
3961
3962 ssh_pkt_getstring(pktin, &string, &stringlen);
3963 if (string == NULL) {
3964 bombout(("Incoming terminal data packet was badly formed"));
3965 return;
3966 }
3967
3968 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
3969 string, stringlen);
3970 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3971 ssh->v1_stdout_throttling = 1;
3972 ssh1_throttle(ssh, +1);
3973 }
3974}
3975
3976static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
3977{
3978 /* Remote side is trying to open a channel to talk to our
3979 * X-Server. Give them back a local channel number. */
3980 struct ssh_channel *c;
3981 int remoteid = ssh_pkt_getuint32(pktin);
3982
3983 logevent("Received X11 connect request");
3984 /* Refuse if X11 forwarding is disabled. */
3985 if (!ssh->X11_fwd_enabled) {
3986 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3987 PKT_INT, remoteid, PKT_END);
3988 logevent("Rejected X11 connect request");
3989 } else {
3990 c = snew(struct ssh_channel);
3991 c->ssh = ssh;
3992
3993 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3994 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3995 logevent("Opening X11 forward connection failed");
3996 sfree(c);
3997 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3998 PKT_INT, remoteid, PKT_END);
3999 } else {
4000 logevent
4001 ("Opening X11 forward connection succeeded");
4002 c->remoteid = remoteid;
4003 c->localid = alloc_channel_id(ssh);
4004 c->closes = 0;
4005 c->v.v1.throttling = 0;
4006 c->type = CHAN_X11; /* identify channel type */
4007 add234(ssh->channels, c);
4008 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4009 PKT_INT, c->remoteid, PKT_INT,
4010 c->localid, PKT_END);
4011 logevent("Opened X11 forward channel");
4012 }
4013 }
4014}
4015
4016static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4017{
4018 /* Remote side is trying to open a channel to talk to our
4019 * agent. Give them back a local channel number. */
4020 struct ssh_channel *c;
4021 int remoteid = ssh_pkt_getuint32(pktin);
4022
4023 /* Refuse if agent forwarding is disabled. */
4024 if (!ssh->agentfwd_enabled) {
4025 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4026 PKT_INT, remoteid, PKT_END);
4027 } else {
4028 c = snew(struct ssh_channel);
4029 c->ssh = ssh;
4030 c->remoteid = remoteid;
4031 c->localid = alloc_channel_id(ssh);
4032 c->closes = 0;
4033 c->v.v1.throttling = 0;
4034 c->type = CHAN_AGENT; /* identify channel type */
4035 c->u.a.lensofar = 0;
4036 add234(ssh->channels, c);
4037 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4038 PKT_INT, c->remoteid, PKT_INT, c->localid,
4039 PKT_END);
4040 }
4041}
4042
4043static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4044{
4045 /* Remote side is trying to open a channel to talk to a
4046 * forwarded port. Give them back a local channel number. */
4047 struct ssh_channel *c;
4048 struct ssh_rportfwd pf;
4049 int remoteid;
4050 int hostsize, port;
4051 char *host, buf[1024];
4052 const char *e;
4053 c = snew(struct ssh_channel);
4054 c->ssh = ssh;
4055
4056 remoteid = ssh_pkt_getuint32(pktin);
4057 ssh_pkt_getstring(pktin, &host, &hostsize);
4058 port = ssh_pkt_getuint32(pktin);
4059
4060 if (hostsize >= lenof(pf.dhost))
4061 hostsize = lenof(pf.dhost)-1;
4062 memcpy(pf.dhost, host, hostsize);
4063 pf.dhost[hostsize] = '\0';
4064 pf.dport = port;
4065
4066 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
4067 sprintf(buf, "Rejected remote port open request for %s:%d",
4068 pf.dhost, port);
4069 logevent(buf);
4070 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4071 PKT_INT, remoteid, PKT_END);
4072 } else {
4073 sprintf(buf, "Received remote port open request for %s:%d",
4074 pf.dhost, port);
4075 logevent(buf);
4076 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4077 c, &ssh->cfg);
4078 if (e != NULL) {
4079 char buf[256];
4080 sprintf(buf, "Port open failed: %s", e);
4081 logevent(buf);
4082 sfree(c);
4083 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4084 PKT_INT, remoteid, PKT_END);
4085 } else {
4086 c->remoteid = remoteid;
4087 c->localid = alloc_channel_id(ssh);
4088 c->closes = 0;
4089 c->v.v1.throttling = 0;
4090 c->type = CHAN_SOCKDATA; /* identify channel type */
4091 add234(ssh->channels, c);
4092 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4093 PKT_INT, c->remoteid, PKT_INT,
4094 c->localid, PKT_END);
4095 logevent("Forwarded port opened successfully");
4096 }
4097 }
4098}
4099
4100static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4101{
4102 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4103 unsigned int localid = ssh_pkt_getuint32(pktin);
4104 struct ssh_channel *c;
4105
4106 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4107 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4108 c->remoteid = localid;
4109 c->type = CHAN_SOCKDATA;
4110 c->v.v1.throttling = 0;
4111 pfd_confirm(c->u.pfd.s);
4112 }
4113
4114 if (c && c->closes) {
4115 /*
4116 * We have a pending close on this channel,
4117 * which we decided on before the server acked
4118 * the channel open. So now we know the
4119 * remoteid, we can close it again.
4120 */
4121 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4122 PKT_INT, c->remoteid, PKT_END);
4123 }
4124}
4125
4126static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4127{
4128 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4129 struct ssh_channel *c;
4130
4131 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4132 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4133 logevent("Forwarded connection refused by server");
4134 pfd_close(c->u.pfd.s);
4135 del234(ssh->channels, c);
4136 sfree(c);
4137 }
4138}
4139
4140static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4141{
4142 /* Remote side closes a channel. */
4143 unsigned i = ssh_pkt_getuint32(pktin);
4144 struct ssh_channel *c;
4145 c = find234(ssh->channels, &i, ssh_channelfind);
4146 if (c && ((int)c->remoteid) != -1) {
4147 int closetype;
4148 closetype =
4149 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4150
4151 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4152 logevent("Forwarded X11 connection terminated");
4153 assert(c->u.x11.s != NULL);
4154 x11_close(c->u.x11.s);
4155 c->u.x11.s = NULL;
4156 }
4157 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4158 logevent("Forwarded port closed");
4159 assert(c->u.pfd.s != NULL);
4160 pfd_close(c->u.pfd.s);
4161 c->u.pfd.s = NULL;
4162 }
4163
4164 c->closes |= (closetype << 2); /* seen this message */
4165 if (!(c->closes & closetype)) {
4166 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4167 PKT_END);
4168 c->closes |= closetype; /* sent it too */
4169 }
4170
4171 if (c->closes == 15) {
4172 del234(ssh->channels, c);
4173 sfree(c);
4174 }
4175 } else {
4176 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4177 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4178 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4179 i));
4180 }
4181}
4182
4183static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4184{
4185 /* Data sent down one of our channels. */
4186 int i = ssh_pkt_getuint32(pktin);
4187 char *p;
aa63ab7e 4188 unsigned int len;
51df0ab5 4189 struct ssh_channel *c;
4190
4191 ssh_pkt_getstring(pktin, &p, &len);
4192
4193 c = find234(ssh->channels, &i, ssh_channelfind);
4194 if (c) {
4195 int bufsize = 0;
4196 switch (c->type) {
4197 case CHAN_X11:
4198 bufsize = x11_send(c->u.x11.s, p, len);
4199 break;
4200 case CHAN_SOCKDATA:
4201 bufsize = pfd_send(c->u.pfd.s, p, len);
4202 break;
4203 case CHAN_AGENT:
4204 /* Data for an agent message. Buffer it. */
4205 while (len > 0) {
4206 if (c->u.a.lensofar < 4) {
aa63ab7e 4207 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4208 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4209 l);
4210 p += l;
4211 len -= l;
4212 c->u.a.lensofar += l;
4213 }
4214 if (c->u.a.lensofar == 4) {
4215 c->u.a.totallen =
4216 4 + GET_32BIT(c->u.a.msglen);
4217 c->u.a.message = snewn(c->u.a.totallen,
4218 unsigned char);
4219 memcpy(c->u.a.message, c->u.a.msglen, 4);
4220 }
4221 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4222 unsigned int l =
51df0ab5 4223 min(c->u.a.totallen - c->u.a.lensofar,
4224 len);
4225 memcpy(c->u.a.message + c->u.a.lensofar, p,
4226 l);
4227 p += l;
4228 len -= l;
4229 c->u.a.lensofar += l;
4230 }
4231 if (c->u.a.lensofar == c->u.a.totallen) {
4232 void *reply;
4233 int replylen;
4234 if (agent_query(c->u.a.message,
4235 c->u.a.totallen,
4236 &reply, &replylen,
4237 ssh_agentf_callback, c))
4238 ssh_agentf_callback(c, reply, replylen);
4239 sfree(c->u.a.message);
4240 c->u.a.lensofar = 0;
4241 }
4242 }
4243 bufsize = 0; /* agent channels never back up */
4244 break;
4245 }
4246 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4247 c->v.v1.throttling = 1;
4248 ssh1_throttle(ssh, +1);
4249 }
4250 }
4251}
4252
4253static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4254{
4255 char buf[100];
4256 ssh->exitcode = ssh_pkt_getuint32(pktin);
4257 sprintf(buf, "Server sent command exit status %d",
4258 ssh->exitcode);
4259 logevent(buf);
4260 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4261 /*
4262 * In case `helpful' firewalls or proxies tack
4263 * extra human-readable text on the end of the
4264 * session which we might mistake for another
4265 * encrypted packet, we close the session once
4266 * we've sent EXIT_CONFIRMATION.
4267 */
4268 ssh_closing((Plug)ssh, NULL, 0, 0);
4269}
4270
b09eaa88 4271static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4272 struct Packet *pktin)
32874aea 4273{
b09eaa88 4274 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4275
51df0ab5 4276 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4277 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4278 ssh1_smsg_stdout_stderr_data;
4279
4280 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4281 ssh1_msg_channel_open_confirmation;
4282 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4283 ssh1_msg_channel_open_failure;
4284 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4285 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4286 ssh1_msg_channel_close;
4287 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4288 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4289
86916870 4290 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4291 logevent("Requesting agent forwarding");
51470298 4292 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4293 do {
4294 crReturnV;
ff3187f6 4295 } while (!pktin);
4296 if (pktin->type != SSH1_SMSG_SUCCESS
4297 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4298 bombout(("Protocol confusion"));
7ffdbc1a 4299 crStopV;
ff3187f6 4300 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4301 logevent("Agent forwarding refused");
4302 } else {
4303 logevent("Agent forwarding enabled");
51470298 4304 ssh->agentfwd_enabled = TRUE;
51df0ab5 4305 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4306 }
dacbd0e8 4307 }
4308
86916870 4309 if (ssh->cfg.x11_forward) {
32874aea 4310 char proto[20], data[64];
4311 logevent("Requesting X11 forwarding");
302121de 4312 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4313 data, sizeof(data), ssh->cfg.x11_auth);
4314 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 4315 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4316 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4317 PKT_STR, proto, PKT_STR, data,
86916870 4318 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4319 PKT_END);
32874aea 4320 } else {
51470298 4321 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4322 PKT_STR, proto, PKT_STR, data, PKT_END);
4323 }
4324 do {
4325 crReturnV;
ff3187f6 4326 } while (!pktin);
4327 if (pktin->type != SSH1_SMSG_SUCCESS
4328 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4329 bombout(("Protocol confusion"));
7ffdbc1a 4330 crStopV;
ff3187f6 4331 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4332 logevent("X11 forwarding refused");
4333 } else {
4334 logevent("X11 forwarding enabled");
51470298 4335 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4336 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4337 }
4338 }
4339
06fadff5 4340 ssh_setup_portfwd(ssh, &ssh->cfg);
4341 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4342
86916870 4343 if (!ssh->cfg.nopty) {
a5dd8467 4344 /* Unpick the terminal-speed string. */
4345 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4346 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4347 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4348 /* Send the pty request. */
51470298 4349 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4350 PKT_STR, ssh->cfg.termtype,
51470298 4351 PKT_INT, ssh->term_height,
4352 PKT_INT, ssh->term_width,
a5dd8467 4353 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4354 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4355 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4356 PKT_CHAR, 0, PKT_END);
51470298 4357 ssh->state = SSH_STATE_INTERMED;
32874aea 4358 do {
4359 crReturnV;
ff3187f6 4360 } while (!pktin);
4361 if (pktin->type != SSH1_SMSG_SUCCESS
4362 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4363 bombout(("Protocol confusion"));
7ffdbc1a 4364 crStopV;
ff3187f6 4365 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4366 c_write_str(ssh, "Server refused to allocate pty\r\n");
4367 ssh->editing = ssh->echoing = 1;
32874aea 4368 }
a5dd8467 4369 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4370 ssh->ospeed, ssh->ispeed);
0965bee0 4371 } else {
51470298 4372 ssh->editing = ssh->echoing = 1;
374330e2 4373 }
4374
86916870 4375 if (ssh->cfg.compression) {
51470298 4376 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4377 do {
4378 crReturnV;
ff3187f6 4379 } while (!pktin);
4380 if (pktin->type != SSH1_SMSG_SUCCESS
4381 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4382 bombout(("Protocol confusion"));
7ffdbc1a 4383 crStopV;
ff3187f6 4384 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4385 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4386 }
4ba9b64b 4387 logevent("Started compression");
51470298 4388 ssh->v1_compressing = TRUE;
5366aed8 4389 ssh->cs_comp_ctx = zlib_compress_init();
4390 logevent("Initialised zlib (RFC1950) compression");
4391 ssh->sc_comp_ctx = zlib_decompress_init();
4392 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4393 }
4394
fd5e5847 4395 /*
4396 * Start the shell or command.
4397 *
4398 * Special case: if the first-choice command is an SSH2
4399 * subsystem (hence not usable here) and the second choice
4400 * exists, we fall straight back to that.
4401 */
4402 {
86916870 4403 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 4404
86916870 4405 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4406 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4407 ssh->fallback_cmd = TRUE;
fd5e5847 4408 }
4409 if (*cmd)
51470298 4410 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4411 else
51470298 4412 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4413 logevent("Started session");
4414 }
374330e2 4415
51470298 4416 ssh->state = SSH_STATE_SESSION;
4417 if (ssh->size_needed)
4418 ssh_size(ssh, ssh->term_width, ssh->term_height);
4419 if (ssh->eof_needed)
4420 ssh_special(ssh, TS_EOF);
374330e2 4421
b9d7bcad 4422 if (ssh->ldisc)
4423 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4424 ssh->send_ok = 1;
4425 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4426 while (1) {
d74d141c 4427
51df0ab5 4428 /*
4429 * By this point, most incoming packets are already being
4430 * handled by the dispatch table, and we need only pay
4431 * attention to the unusual ones.
4432 */
0357890f 4433
51df0ab5 4434 crReturnV;
4435 if (pktin) {
4436 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4437 /* may be from EXEC_SHELL on some servers */
ff3187f6 4438 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4439 /* may be from EXEC_SHELL on some servers
374330e2 4440 * if no pty is available or in other odd cases. Ignore */
374330e2 4441 } else {
ff3187f6 4442 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4443 crStopV;
374330e2 4444 }
4445 } else {
8df7a775 4446 while (inlen > 0) {
4447 int len = min(inlen, 512);
9a10ecf4 4448 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4449 PKT_INT, len, PKT_DATA, in, len,
4450 PKTT_OTHER, PKT_END);
8df7a775 4451 in += len;
4452 inlen -= len;
4453 }
374330e2 4454 }
4455 }
4456
4457 crFinishV;
4458}
4459
4460/*
b09eaa88 4461 * Handle the top-level SSH2 protocol.
4462 */
4463static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4464{
4465 char *buf, *msg;
4466 int msglen;
4467
4468 ssh_pkt_getstring(pktin, &msg, &msglen);
4469 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4470 logevent(buf);
4471 sfree(buf);
4472}
4473
4474static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4475{
4476 /* log reason code in disconnect message */
4477 char *msg;
4478 int msglen;
4479
4480 ssh_pkt_getstring(pktin, &msg, &msglen);
4481 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4482}
4483
4484void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4485{
4486 /* Do nothing, because we're ignoring it! Duhh. */
4487}
4488
4489static void ssh1_protocol_setup(Ssh ssh)
4490{
4491 int i;
4492
4493 /*
4494 * Most messages are handled by the coroutines.
4495 */
4496 for (i = 0; i < 256; i++)
4497 ssh->packet_dispatch[i] = NULL;
4498
4499 /*
4500 * These special message types we install handlers for.
4501 */
4502 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4503 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4504 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4505}
4506
4507static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4508 struct Packet *pktin)
4509{
4510 if (ssh->state == SSH_STATE_CLOSED)
4511 return;
4512
4513 if (pktin && ssh->packet_dispatch[pktin->type]) {
4514 ssh->packet_dispatch[pktin->type](ssh, pktin);
4515 return;
4516 }
4517
4518 if (!ssh->protocol_initial_phase_done) {
4519 if (do_ssh1_login(ssh, in, inlen, pktin))
4520 ssh->protocol_initial_phase_done = TRUE;
4521 else
4522 return;
4523 }
4524
4525 do_ssh1_connection(ssh, in, inlen, pktin);
4526}
4527
4528/*
e5574168 4529 * Utility routine for decoding comma-separated strings in KEXINIT.
4530 */
32874aea 4531static int in_commasep_string(char *needle, char *haystack, int haylen)
4532{
57356d63 4533 int needlen;
4534 if (!needle || !haystack) /* protect against null pointers */
4535 return 0;
4536 needlen = strlen(needle);
e5574168 4537 while (1) {
32874aea 4538 /*
4539 * Is it at the start of the string?
4540 */
4541 if (haylen >= needlen && /* haystack is long enough */
4542 !memcmp(needle, haystack, needlen) && /* initial match */
4543 (haylen == needlen || haystack[needlen] == ',')
4544 /* either , or EOS follows */
4545 )
4546 return 1;
4547 /*
4548 * If not, search for the next comma and resume after that.
4549 * If no comma found, terminate.
4550 */
4551 while (haylen > 0 && *haystack != ',')
4552 haylen--, haystack++;
4553 if (haylen == 0)
4554 return 0;
4555 haylen--, haystack++; /* skip over comma itself */
e5574168 4556 }
4557}
4558
4559/*
d39f364a 4560 * SSH2 key creation method.
4561 */
d8baa528 4562static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4563 unsigned char *sessid, char chr,
4564 unsigned char *keyspace)
32874aea 4565{
d39f364a 4566 SHA_State s;
4567 /* First 20 bytes. */
4568 SHA_Init(&s);
51470298 4569 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4570 sha_mpint(&s, K);
d39f364a 4571 SHA_Bytes(&s, H, 20);
4572 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4573 SHA_Bytes(&s, sessid, 20);
d39f364a 4574 SHA_Final(&s, keyspace);
4575 /* Next 20 bytes. */
4576 SHA_Init(&s);
51470298 4577 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4578 sha_mpint(&s, K);
d39f364a 4579 SHA_Bytes(&s, H, 20);
4580 SHA_Bytes(&s, keyspace, 20);
32874aea 4581 SHA_Final(&s, keyspace + 20);
d39f364a 4582}
4583
4584/*
7cca0d81 4585 * Handle the SSH2 transport layer.
e5574168 4586 */
ff3187f6 4587static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4588 struct Packet *pktin)
e5574168 4589{
51470298 4590 struct do_ssh2_transport_state {
4591 int nbits, pbits, warn;
4592 Bignum p, g, e, f, K;
4593 int kex_init_value, kex_reply_value;
4594 const struct ssh_mac **maclist;
4595 int nmacs;
4596 const struct ssh2_cipher *cscipher_tobe;
4597 const struct ssh2_cipher *sccipher_tobe;
4598 const struct ssh_mac *csmac_tobe;
4599 const struct ssh_mac *scmac_tobe;
4600 const struct ssh_compress *cscomp_tobe;
4601 const struct ssh_compress *sccomp_tobe;
4602 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4603 int hostkeylen, siglen;
4604 void *hkey; /* actual host key */
4605 unsigned char exchange_hash[20];
83e7d008 4606 int n_preferred_kex;
4607 const struct ssh_kex *preferred_kex[KEX_MAX];
51470298 4608 int n_preferred_ciphers;
4609 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4610 const struct ssh_compress *preferred_comp;
4611 int first_kex;
ff3187f6 4612 struct Packet *pktout;
51470298 4613 };
4614 crState(do_ssh2_transport_state);
4615
4616 crBegin(ssh->do_ssh2_transport_crstate);
4617
4618 s->cscipher_tobe = s->sccipher_tobe = NULL;
4619 s->csmac_tobe = s->scmac_tobe = NULL;
4620 s->cscomp_tobe = s->sccomp_tobe = NULL;
4621
51470298 4622 s->first_kex = 1;
e5574168 4623
51470298 4624 {
4625 int i;
4626 /*
83e7d008 4627 * Set up the preferred key exchange. (NULL => warn below here)
4628 */
4629 s->n_preferred_kex = 0;
4630 for (i = 0; i < KEX_MAX; i++) {
4631 switch (ssh->cfg.ssh_kexlist[i]) {
4632 case KEX_DHGEX:
4633 s->preferred_kex[s->n_preferred_kex++] =
4634 &ssh_diffiehellman_gex;
4635 break;
4636 case KEX_DHGROUP14:
4637 s->preferred_kex[s->n_preferred_kex++] =
4638 &ssh_diffiehellman_group14;
4639 break;
4640 case KEX_DHGROUP1:
4641 s->preferred_kex[s->n_preferred_kex++] =
4642 &ssh_diffiehellman_group1;
4643 break;
4644 case CIPHER_WARN:
4645 /* Flag for later. Don't bother if it's the last in
4646 * the list. */
4647 if (i < KEX_MAX - 1) {
4648 s->preferred_kex[s->n_preferred_kex++] = NULL;
4649 }
4650 break;
4651 }
4652 }
4653 }
4654
4655 {
4656 int i;
4657 /*
51470298 4658 * Set up the preferred ciphers. (NULL => warn below here)
4659 */
4660 s->n_preferred_ciphers = 0;
4661 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4662 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4663 case CIPHER_BLOWFISH:
4664 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4665 break;
4666 case CIPHER_DES:
86916870 4667 if (ssh->cfg.ssh2_des_cbc) {
51470298 4668 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4669 }
4670 break;
4671 case CIPHER_3DES:
4672 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4673 break;
4674 case CIPHER_AES:
4675 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4676 break;
4677 case CIPHER_WARN:
4678 /* Flag for later. Don't bother if it's the last in
4679 * the list. */
4680 if (i < CIPHER_MAX - 1) {
4681 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4682 }
4683 break;
ca20bfcf 4684 }
ca20bfcf 4685 }
5e8358ad 4686 }
ca20bfcf 4687
4688 /*
4689 * Set up preferred compression.
4690 */
86916870 4691 if (ssh->cfg.compression)
51470298 4692 s->preferred_comp = &ssh_zlib;
4ba9b64b 4693 else
51470298 4694 s->preferred_comp = &ssh_comp_none;
5e8358ad 4695
7591b9ff 4696 /*
4697 * Be prepared to work around the buggy MAC problem.
4698 */
51470298 4699 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4700 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 4701 else
51470298 4702 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 4703
32874aea 4704 begin_key_exchange:
51470298 4705 {
83e7d008 4706 int i, j, commalist_started;
51470298 4707
4708 /*
590f6a5f 4709 * Enable queueing of outgoing auth- or connection-layer
4710 * packets while we are in the middle of a key exchange.
4711 */
4712 ssh->queueing = TRUE;
4713
4714 /*
9442dd57 4715 * Flag that KEX is in progress.
4716 */
4717 ssh->kex_in_progress = TRUE;
4718
4719 /*
51470298 4720 * Construct and send our key exchange packet.
4721 */
ff3187f6 4722 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4723 for (i = 0; i < 16; i++)
ff3187f6 4724 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4725 /* List key exchange algorithms. */
ff3187f6 4726 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4727 commalist_started = 0;
4728 for (i = 0; i < s->n_preferred_kex; i++) {
4729 const struct ssh_kex *k = s->preferred_kex[i];
4730 if (!k) continue; /* warning flag */
4731 if (commalist_started)
ff3187f6 4732 ssh2_pkt_addstring_str(s->pktout, ",");
83e7d008 4733 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4734 commalist_started = 1;
32874aea 4735 }
51470298 4736 /* List server host key algorithms. */
ff3187f6 4737 ssh2_pkt_addstring_start(s->pktout);
51470298 4738 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4739 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4740 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4741 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4742 }
51470298 4743 /* List client->server encryption algorithms. */
ff3187f6 4744 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4745 commalist_started = 0;
51470298 4746 for (i = 0; i < s->n_preferred_ciphers; i++) {
4747 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4748 if (!c) continue; /* warning flag */
4749 for (j = 0; j < c->nciphers; j++) {
83e7d008 4750 if (commalist_started)
ff3187f6 4751 ssh2_pkt_addstring_str(s->pktout, ",");
4752 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4753 commalist_started = 1;
51470298 4754 }
4755 }
4756 /* List server->client encryption algorithms. */
ff3187f6 4757 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4758 commalist_started = 0;
51470298 4759 for (i = 0; i < s->n_preferred_ciphers; i++) {
4760 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4761 if (!c) continue; /* warning flag */
4762 for (j = 0; j < c->nciphers; j++) {
83e7d008 4763 if (commalist_started)
ff3187f6 4764 ssh2_pkt_addstring_str(s->pktout, ",");
4765 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4766 commalist_started = 1;
51470298 4767 }
4768 }
4769 /* List client->server MAC algorithms. */
ff3187f6 4770 ssh2_pkt_addstring_start(s->pktout);
51470298 4771 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4772 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4773 if (i < s->nmacs - 1)
ff3187f6 4774 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4775 }
4776 /* List server->client MAC algorithms. */
ff3187f6 4777 ssh2_pkt_addstring_start(s->pktout);
51470298 4778 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4779 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4780 if (i < s->nmacs - 1)
ff3187f6 4781 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4782 }
4783 /* List client->server compression algorithms. */
ff3187f6 4784 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4785 assert(lenof(compressions) > 1);
ff3187f6 4786 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4787 for (i = 0; i < lenof(compressions); i++) {
4788 const struct ssh_compress *c = compressions[i];
4789 if (c != s->preferred_comp) {
ff3187f6 4790 ssh2_pkt_addstring_str(s->pktout, ",");
4791 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4792 }
51470298 4793 }
4794 /* List server->client compression algorithms. */
ff3187f6 4795 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4796 assert(lenof(compressions) > 1);
ff3187f6 4797 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4798 for (i = 0; i < lenof(compressions); i++) {
4799 const struct ssh_compress *c = compressions[i];
4800 if (c != s->preferred_comp) {
ff3187f6 4801 ssh2_pkt_addstring_str(s->pktout, ",");
4802 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4803 }
51470298 4804 }
4805 /* List client->server languages. Empty list. */
ff3187f6 4806 ssh2_pkt_addstring_start(s->pktout);
51470298 4807 /* List server->client languages. Empty list. */
ff3187f6 4808 ssh2_pkt_addstring_start(s->pktout);
51470298 4809 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4810 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4811 /* Reserved. */
ff3187f6 4812 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4813 }
0db56f73 4814
51470298 4815 ssh->exhash = ssh->exhashbase;
ff3187f6 4816 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4817
590f6a5f 4818 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4819
ff3187f6 4820 if (!pktin)
4821 crWaitUntil(pktin);
4822 if (pktin->length > 5)
4823 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4824
4825 /*
4826 * Now examine the other side's KEXINIT to see what we're up
4827 * to.
4828 */
51470298 4829 {
4830 char *str;
4831 int i, j, len;
4832
ff3187f6 4833 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4834 bombout(("expected key exchange packet from server"));
7ffdbc1a 4835 crStop(0);
32874aea 4836 }
51470298 4837 ssh->kex = NULL;
4838 ssh->hostkey = NULL;
4839 s->cscipher_tobe = NULL;
4840 s->sccipher_tobe = NULL;
4841 s->csmac_tobe = NULL;
4842 s->scmac_tobe = NULL;
4843 s->cscomp_tobe = NULL;
4844 s->sccomp_tobe = NULL;
ff3187f6 4845 pktin->savedpos += 16; /* skip garbage cookie */
4846 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
83e7d008 4847 s->warn = 0;
4848 for (i = 0; i < s->n_preferred_kex; i++) {
4849 const struct ssh_kex *k = s->preferred_kex[i];
4850 if (!k) {
4851 s->warn = 1;
4852 } else if (in_commasep_string(k->name, str, len)) {
4853 ssh->kex = k;
4854 }
4855 if (ssh->kex) {
4856 if (s->warn)
4857 askalg(ssh->frontend, "key-exchange algorithm",
4858 ssh->kex->name);
51470298 4859 break;
4860 }
32874aea 4861 }
83e7d008 4862 if (!ssh->kex) {
4863 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4864 str ? str : "(null)"));
4865 crStop(0);
4866 }
ff3187f6 4867 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4868 for (i = 0; i < lenof(hostkey_algs); i++) {
4869 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4870 ssh->hostkey = hostkey_algs[i];
4871 break;
4872 }
4873 }
ff3187f6 4874 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4875 s->warn = 0;
4876 for (i = 0; i < s->n_preferred_ciphers; i++) {
4877 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4878 if (!c) {
4879 s->warn = 1;
4880 } else {
4881 for (j = 0; j < c->nciphers; j++) {
4882 if (in_commasep_string(c->list[j]->name, str, len)) {
4883 s->cscipher_tobe = c->list[j];
4884 break;
4885 }
ca20bfcf 4886 }
32874aea 4887 }
51470298 4888 if (s->cscipher_tobe) {
4889 if (s->warn)
83e7d008 4890 askalg(ssh->frontend, "client-to-server cipher",
4891 s->cscipher_tobe->name);
51470298 4892 break;
4893 }
32874aea 4894 }
51470298 4895 if (!s->cscipher_tobe) {
6b5cf8b4 4896 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4897 str ? str : "(null)"));
7ffdbc1a 4898 crStop(0);
ca20bfcf 4899 }
0ef8f407 4900
ff3187f6 4901 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4902 s->warn = 0;
4903 for (i = 0; i < s->n_preferred_ciphers; i++) {
4904 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4905 if (!c) {
4906 s->warn = 1;
4907 } else {
4908 for (j = 0; j < c->nciphers; j++) {
4909 if (in_commasep_string(c->list[j]->name, str, len)) {
4910 s->sccipher_tobe = c->list[j];
4911 break;
4912 }
ca20bfcf 4913 }
32874aea 4914 }
51470298 4915 if (s->sccipher_tobe) {
4916 if (s->warn)
83e7d008 4917 askalg(ssh->frontend, "server-to-client cipher",
4918 s->sccipher_tobe->name);
51470298 4919 break;
4920 }
32874aea 4921 }
51470298 4922 if (!s->sccipher_tobe) {
6b5cf8b4 4923 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4924 str ? str : "(null)"));
7ffdbc1a 4925 crStop(0);
ca20bfcf 4926 }
0ef8f407 4927
ff3187f6 4928 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 4929 for (i = 0; i < s->nmacs; i++) {
4930 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4931 s->csmac_tobe = s->maclist[i];
4932 break;
4933 }
32874aea 4934 }
ff3187f6 4935 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 4936 for (i = 0; i < s->nmacs; i++) {
4937 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4938 s->scmac_tobe = s->maclist[i];
4939 break;
4940 }
32874aea 4941 }
ff3187f6 4942 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 4943 for (i = 0; i < lenof(compressions) + 1; i++) {
4944 const struct ssh_compress *c =
4945 i == 0 ? s->preferred_comp : compressions[i - 1];
4946 if (in_commasep_string(c->name, str, len)) {
4947 s->cscomp_tobe = c;
4948 break;
4949 }
32874aea 4950 }
ff3187f6 4951 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 4952 for (i = 0; i < lenof(compressions) + 1; i++) {
4953 const struct ssh_compress *c =
4954 i == 0 ? s->preferred_comp : compressions[i - 1];
4955 if (in_commasep_string(c->name, str, len)) {
4956 s->sccomp_tobe = c;
4957 break;
4958 }
32874aea 4959 }
e5574168 4960 }
e5574168 4961
4962 /*
7bd5a860 4963 * Work out the number of bits of key we will need from the key
4964 * exchange. We start with the maximum key length of either
4965 * cipher...
4966 */
4967 {
32874aea 4968 int csbits, scbits;
7bd5a860 4969
51470298 4970 csbits = s->cscipher_tobe->keylen;
4971 scbits = s->sccipher_tobe->keylen;
4972 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 4973 }
4974 /* The keys only have 160-bit entropy, since they're based on
4975 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 4976 if (s->nbits > 160)
4977 s->nbits = 160;
7bd5a860 4978
4979 /*
a92dd380 4980 * If we're doing Diffie-Hellman group exchange, start by
4981 * requesting a group.
e5574168 4982 */
d1aaf71d 4983 if (!ssh->kex->pdata) {
32874aea 4984 logevent("Doing Diffie-Hellman group exchange");
51470298 4985 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 4986 /*
4987 * Work out how big a DH group we will need to allow that
4988 * much data.
7bd5a860 4989 */
51470298 4990 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 4991 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
4992 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 4993 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 4994
ff3187f6 4995 crWaitUntil(pktin);
4996 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 4997 bombout(("expected key exchange group packet from server"));
7ffdbc1a 4998 crStop(0);
32874aea 4999 }
ff3187f6 5000 s->p = ssh2_pkt_getmp(pktin);
5001 s->g = ssh2_pkt_getmp(pktin);
5002 if (!s->p || !s->g) {
5003 bombout(("unable to read mp-ints from incoming group packet"));
5004 crStop(0);
5005 }
d1aaf71d 5006 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5007 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5008 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5009 } else {
d1aaf71d 5010 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5011 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5012 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5013 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5014 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5015 ssh->kex->groupname);
8d5de777 5016 }
e5574168 5017
a92dd380 5018 logevent("Doing Diffie-Hellman key exchange");
e5574168 5019 /*
a92dd380 5020 * Now generate and send e for Diffie-Hellman.
e5574168 5021 */
27cd7fc2 5022 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5023 s->pktout = ssh2_pkt_init(s->kex_init_value);
5024 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5025 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5026
ff3187f6 5027 crWaitUntil(pktin);
5028 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5029 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5030 crStop(0);
7cca0d81 5031 }
ff3187f6 5032 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5033 s->f = ssh2_pkt_getmp(pktin);
5034 if (!s->f) {
5035 bombout(("unable to parse key exchange reply packet"));
5036 crStop(0);
5037 }
5038 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5039
27cd7fc2 5040 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5041
51470298 5042 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5043 if (ssh->kex == &ssh_diffiehellman_gex) {
5044 sha_uint32(&ssh->exhash, s->pbits);
5045 sha_mpint(&ssh->exhash, s->p);
5046 sha_mpint(&ssh->exhash, s->g);
a92dd380 5047 }
51470298 5048 sha_mpint(&ssh->exhash, s->e);
5049 sha_mpint(&ssh->exhash, s->f);
5050 sha_mpint(&ssh->exhash, s->K);
5051 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 5052
27cd7fc2 5053 dh_cleanup(ssh->kex_ctx);
fabd1805 5054 ssh->kex_ctx = NULL;
3709bfe9 5055
7cca0d81 5056#if 0
765c4200 5057 debug(("Exchange hash is:\n"));
51470298 5058 dmemdump(s->exchange_hash, 20);
7cca0d81 5059#endif
5060
51470298 5061 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5062 if (!s->hkey ||
5063 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 5064 (char *)s->exchange_hash, 20)) {
6b5cf8b4 5065 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5066 crStop(0);
8d5de777 5067 }
e5574168 5068
5069 /*
7cca0d81 5070 * Authenticate remote host: verify host key. (We've already
5071 * checked the signature of the exchange hash.)
e5574168 5072 */
51470298 5073 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5074 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 5075 verify_ssh_host_key(ssh->frontend,
5076 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 5077 s->keystr, s->fingerprint);
5078 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 5079 logevent("Host key fingerprint is:");
51470298 5080 logevent(s->fingerprint);
5e0d7cb8 5081 }
51470298 5082 sfree(s->fingerprint);
5083 sfree(s->keystr);
5084 ssh->hostkey->freekey(s->hkey);
d39f364a 5085
5086 /*
9442dd57 5087 * The exchange hash from the very first key exchange is also
5088 * the session id, used in session key construction and
5089 * authentication.
5090 */
5091 if (s->first_kex)
5092 memcpy(ssh->v2_session_id, s->exchange_hash,
5093 sizeof(s->exchange_hash));
5094
5095 /*
7cca0d81 5096 * Send SSH2_MSG_NEWKEYS.
d39f364a 5097 */
ff3187f6 5098 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5099 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5100 ssh->outgoing_data_size = 0; /* start counting from here */
5101
5102 /*
5103 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5104 * client-to-server session keys.
9442dd57 5105 */
5106 if (ssh->cs_cipher_ctx)
5107 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5108 ssh->cscipher = s->cscipher_tobe;
5109 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5110
5111 if (ssh->cs_mac_ctx)
5112 ssh->csmac->free_context(ssh->cs_mac_ctx);
5113 ssh->csmac = s->csmac_tobe;
5114 ssh->cs_mac_ctx = ssh->csmac->make_context();
5115
5116 if (ssh->cs_comp_ctx)
5117 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5118 ssh->cscomp = s->cscomp_tobe;
5119 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5120
5121 /*
5122 * Set IVs on client-to-server keys. Here we use the exchange
5123 * hash from the _first_ key exchange.
5124 */
5125 {
5126 unsigned char keyspace[40];
5127 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5128 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5129 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5130 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5131 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5132 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5133 }
5134
5135 logeventf(ssh, "Initialised %.200s client->server encryption",
5136 ssh->cscipher->text_name);
5137 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5138 ssh->csmac->text_name);
5139 if (ssh->cscomp->text_name)
5140 logeventf(ssh, "Initialised %s compression",
5141 ssh->cscomp->text_name);
590f6a5f 5142
5143 /*
5144 * Now our end of the key exchange is complete, we can send all
5145 * our queued higher-layer packets.
5146 */
5147 ssh->queueing = FALSE;
5148 ssh2_pkt_queuesend(ssh);
d39f364a 5149
5150 /*
8406eaf9 5151 * Expect SSH2_MSG_NEWKEYS from server.
5152 */
ff3187f6 5153 crWaitUntil(pktin);
5154 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5155 bombout(("expected new-keys packet from server"));
7ffdbc1a 5156 crStop(0);
8406eaf9 5157 }
9442dd57 5158 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5159
5160 /*
9442dd57 5161 * We've seen server NEWKEYS, so create and initialise
5162 * server-to-client session keys.
d39f364a 5163 */
371e569c 5164 if (ssh->sc_cipher_ctx)
5165 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5166 ssh->sccipher = s->sccipher_tobe;
371e569c 5167 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5168
e0e1a00d 5169 if (ssh->sc_mac_ctx)
5170 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5171 ssh->scmac = s->scmac_tobe;
e0e1a00d 5172 ssh->sc_mac_ctx = ssh->scmac->make_context();
5173
5366aed8 5174 if (ssh->sc_comp_ctx)
5175 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5176 ssh->sccomp = s->sccomp_tobe;
5366aed8 5177 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5178
d39f364a 5179 /*
9442dd57 5180 * Set IVs on server-to-client keys. Here we use the exchange
5181 * hash from the _first_ key exchange.
d39f364a 5182 */
51470298 5183 {
5184 unsigned char keyspace[40];
51470298 5185 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 5186 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 5187 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 5188 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 5189 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 5190 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5191 }
57356d63 5192 logeventf(ssh, "Initialised %.200s server->client encryption",
5193 ssh->sccipher->text_name);
6c135243 5194 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5195 ssh->scmac->text_name);
57356d63 5196 if (ssh->sccomp->text_name)
5197 logeventf(ssh, "Initialised %s decompression",
5198 ssh->sccomp->text_name);
9442dd57 5199
5200 /*
5201 * Free key exchange data.
5202 */
679539d7 5203 freebn(s->f);
679539d7 5204 freebn(s->K);
b3949e7e 5205 if (ssh->kex == &ssh_diffiehellman_gex) {
5206 freebn(s->g);
5207 freebn(s->p);
5208 }
d39f364a 5209
033b4cef 5210 /*
9442dd57 5211 * Key exchange is over. Schedule a timer for our next rekey.
5212 */
5213 ssh->kex_in_progress = FALSE;
e6c1536e 5214 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5215 if (ssh->cfg.ssh_rekey_time != 0)
5216 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5217 ssh2_timer, ssh);
5218
9442dd57 5219 /*
0db56f73 5220 * If this is the first key exchange phase, we must pass the
5221 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5222 * wants to see it but because it will need time to initialise
5223 * itself before it sees an actual packet. In subsequent key
5224 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5225 * it would only confuse the layer above.
5226 */
51470298 5227 if (!s->first_kex) {
b09eaa88 5228 crReturn(1);
0db56f73 5229 }
51470298 5230 s->first_kex = 0;
0db56f73 5231
5232 /*
7cca0d81 5233 * Now we're encrypting. Begin returning 1 to the protocol main
5234 * function so that other things can run on top of the
5235 * transport. If we ever see a KEXINIT, we must go back to the
5236 * start.
9442dd57 5237 *
5238 * We _also_ go back to the start if we see pktin==NULL and
5239 * inlen==-1, because this is a special signal meaning
5240 * `initiate client-driven rekey', and `in' contains a message
5241 * giving the reason for the rekey.
033b4cef 5242 */
9442dd57 5243 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5244 (!pktin && inlen == -1))) {
32874aea 5245 crReturn(1);
e96adf72 5246 }
9442dd57 5247 if (pktin) {
5248 logevent("Server initiated key re-exchange");
5249 } else {
5250 logevent((char *)in);
5251 }
7cca0d81 5252 goto begin_key_exchange;
e5574168 5253
5254 crFinish(1);
5255}
5256
7cca0d81 5257/*
783415f8 5258 * Add data to an SSH2 channel output buffer.
5259 */
32874aea 5260static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5261 int len)
5262{
5471d09a 5263 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5264}
5265
5266/*
5267 * Attempt to send data on an SSH2 channel.
5268 */
5471d09a 5269static int ssh2_try_send(struct ssh_channel *c)
32874aea 5270{
51470298 5271 Ssh ssh = c->ssh;
ff3187f6 5272 struct Packet *pktout;
51470298 5273
5471d09a 5274 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5275 int len;
5276 void *data;
5277 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5278 if ((unsigned)len > c->v.v2.remwindow)
5279 len = c->v.v2.remwindow;
5280 if ((unsigned)len > c->v.v2.remmaxpkt)
5281 len = c->v.v2.remmaxpkt;
ff3187f6 5282 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5283 ssh2_pkt_adduint32(pktout, c->remoteid);
5284 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5285 ssh2_pkt_addstring_start(pktout);
5286 ssh2_pkt_addstring_data(pktout, data, len);
5287 end_log_omission(ssh, pktout);
5288 ssh2_pkt_send(ssh, pktout);
5471d09a 5289 bufchain_consume(&c->v.v2.outbuffer, len);
5290 c->v.v2.remwindow -= len;
5291 }
5292
5293 /*
5294 * After having sent as much data as we can, return the amount
5295 * still buffered.
5296 */
5297 return bufchain_size(&c->v.v2.outbuffer);
5298}
5299
5300/*
5301 * Potentially enlarge the window on an SSH2 channel.
5302 */
5303static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5304{
51470298 5305 Ssh ssh = c->ssh;
5306
6b69f42e 5307 /*
5308 * Never send WINDOW_ADJUST for a channel that the remote side
5309 * already thinks it's closed; there's no point, since it won't
5310 * be sending any more data anyway.
5311 */
5312 if (c->closes != 0)
5313 return;
5314
5471d09a 5315 if (newwin > c->v.v2.locwindow) {
ff3187f6 5316 struct Packet *pktout;
5317
5318 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5319 ssh2_pkt_adduint32(pktout, c->remoteid);
5320 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5321 ssh2_pkt_send(ssh, pktout);
5471d09a 5322 c->v.v2.locwindow = newwin;
783415f8 5323 }
5324}
5325
51df0ab5 5326static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5327{
5328 unsigned i = ssh_pkt_getuint32(pktin);
5329 struct ssh_channel *c;
5330 c = find234(ssh->channels, &i, ssh_channelfind);
5331 if (c && !c->closes)
5332 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5333}
5334
51df0ab5 5335static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5336{
5337 char *data;
aa63ab7e 5338 unsigned int length;
51df0ab5 5339 unsigned i = ssh_pkt_getuint32(pktin);
5340 struct ssh_channel *c;
5341 c = find234(ssh->channels, &i, ssh_channelfind);
5342 if (!c)
5343 return; /* nonexistent channel */
5344 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5345 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5346 return; /* extended but not stderr */
5347 ssh_pkt_getstring(pktin, &data, &length);
5348 if (data) {
5349 int bufsize = 0;
5350 c->v.v2.locwindow -= length;
5351 switch (c->type) {
5352 case CHAN_MAINSESSION:
5353 bufsize =
5354 from_backend(ssh->frontend, pktin->type ==
5355 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5356 data, length);
5357 break;
5358 case CHAN_X11:
5359 bufsize = x11_send(c->u.x11.s, data, length);
5360 break;
5361 case CHAN_SOCKDATA:
5362 bufsize = pfd_send(c->u.pfd.s, data, length);
5363 break;
5364 case CHAN_AGENT:
5365 while (length > 0) {
5366 if (c->u.a.lensofar < 4) {
aa63ab7e 5367 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5368 memcpy(c->u.a.msglen + c->u.a.lensofar,
5369 data, l);
5370 data += l;
5371 length -= l;
5372 c->u.a.lensofar += l;
5373 }
5374 if (c->u.a.lensofar == 4) {
5375 c->u.a.totallen =
5376 4 + GET_32BIT(c->u.a.msglen);
5377 c->u.a.message = snewn(c->u.a.totallen,
5378 unsigned char);
5379 memcpy(c->u.a.message, c->u.a.msglen, 4);
5380 }
5381 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5382 unsigned int l =
51df0ab5 5383 min(c->u.a.totallen - c->u.a.lensofar,
5384 length);
5385 memcpy(c->u.a.message + c->u.a.lensofar,
5386 data, l);
5387 data += l;
5388 length -= l;
5389 c->u.a.lensofar += l;
5390 }
5391 if (c->u.a.lensofar == c->u.a.totallen) {
5392 void *reply;
5393 int replylen;
5394 if (agent_query(c->u.a.message,
5395 c->u.a.totallen,
5396 &reply, &replylen,
5397 ssh_agentf_callback, c))
5398 ssh_agentf_callback(c, reply, replylen);
5399 sfree(c->u.a.message);
5400 c->u.a.lensofar = 0;
5401 }
5402 }
5403 bufsize = 0;
5404 break;
5405 }
5406 /*
5407 * If we are not buffering too much data,
5408 * enlarge the window again at the remote side.
5409 */
5410 if (bufsize < OUR_V2_WINSIZE)
5411 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5412 }
5413}
5414
5415static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5416{
5417 unsigned i = ssh_pkt_getuint32(pktin);
5418 struct ssh_channel *c;
5419
5420 c = find234(ssh->channels, &i, ssh_channelfind);
5421 if (!c)
5422 return; /* nonexistent channel */
5423
5424 if (c->type == CHAN_X11) {
5425 /*
5426 * Remote EOF on an X11 channel means we should
5427 * wrap up and close the channel ourselves.
5428 */
5429 x11_close(c->u.x11.s);
5430 sshfwd_close(c);
5431 } else if (c->type == CHAN_AGENT) {
5432 sshfwd_close(c);
5433 } else if (c->type == CHAN_SOCKDATA) {
5434 pfd_close(c->u.pfd.s);
5435 sshfwd_close(c);
5436 }
5437}
5438
5439static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5440{
5441 unsigned i = ssh_pkt_getuint32(pktin);
5442 struct ssh_channel *c;
5443 struct Packet *pktout;
5444
5445 c = find234(ssh->channels, &i, ssh_channelfind);
5446 if (!c || ((int)c->remoteid) == -1) {
5447 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5448 c ? "half-open" : "nonexistent", i));
5449 return;
5450 }
5451 /* Do pre-close processing on the channel. */
5452 switch (c->type) {
5453 case CHAN_MAINSESSION:
5454 ssh->mainchan = NULL;
5455 update_specials_menu(ssh->frontend);
5456 break;
5457 case CHAN_X11:
5458 if (c->u.x11.s != NULL)
5459 x11_close(c->u.x11.s);
5460 sshfwd_close(c);
5461 break;
5462 case CHAN_AGENT:
5463 sshfwd_close(c);
5464 break;
5465 case CHAN_SOCKDATA:
5466 if (c->u.pfd.s != NULL)
5467 pfd_close(c->u.pfd.s);
5468 sshfwd_close(c);
5469 break;
5470 }
5471 if (c->closes == 0) {
5472 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5473 ssh2_pkt_adduint32(pktout, c->remoteid);
5474 ssh2_pkt_send(ssh, pktout);
5475 }
5476 del234(ssh->channels, c);
5477 bufchain_clear(&c->v.v2.outbuffer);
5478 sfree(c);
5479
5480 /*
5481 * See if that was the last channel left open.
5482 * (This is only our termination condition if we're
5483 * not running in -N mode.)
5484 */
5485 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5486 logevent("All channels closed. Disconnecting");
5487#if 0
5488 /*
5489 * We used to send SSH_MSG_DISCONNECT here,
5490 * because I'd believed that _every_ conforming
5491 * SSH2 connection had to end with a disconnect
5492 * being sent by at least one side; apparently
5493 * I was wrong and it's perfectly OK to
5494 * unceremoniously slam the connection shut
5495 * when you're done, and indeed OpenSSH feels
5496 * this is more polite than sending a
5497 * DISCONNECT. So now we don't.
5498 */
5499 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5500 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5501 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5502 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5503 ssh2_pkt_send_noqueue(ssh, s->pktout);
5504#endif
5505 ssh_closing((Plug)ssh, NULL, 0, 0);
5506 }
5507}
5508
5509static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5510{
5511 unsigned i = ssh_pkt_getuint32(pktin);
5512 struct ssh_channel *c;
5513 struct Packet *pktout;
5514
5515 c = find234(ssh->channels, &i, ssh_channelfind);
5516 if (!c)
5517 return; /* nonexistent channel */
5518 if (c->type != CHAN_SOCKDATA_DORMANT)
5519 return; /* dunno why they're confirming this */
5520 c->remoteid = ssh_pkt_getuint32(pktin);
5521 c->type = CHAN_SOCKDATA;
5522 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5523 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5524 if (c->u.pfd.s)
5525 pfd_confirm(c->u.pfd.s);
5526 if (c->closes) {
5527 /*
5528 * We have a pending close on this channel,
5529 * which we decided on before the server acked
5530 * the channel open. So now we know the
5531 * remoteid, we can close it again.
5532 */
5533 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5534 ssh2_pkt_adduint32(pktout, c->remoteid);
5535 ssh2_pkt_send(ssh, pktout);
5536 }
5537}
5538
5539static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5540{
5541 static const char *const reasons[] = {
5542 "<unknown reason code>",
5543 "Administratively prohibited",
5544 "Connect failed",
5545 "Unknown channel type",
5546 "Resource shortage",
5547 };
5548 unsigned i = ssh_pkt_getuint32(pktin);
5549 unsigned reason_code;
5550 char *reason_string;
5551 int reason_length;
5552 char *message;
5553 struct ssh_channel *c;
5554 c = find234(ssh->channels, &i, ssh_channelfind);
5555 if (!c)
5556 return; /* nonexistent channel */
5557 if (c->type != CHAN_SOCKDATA_DORMANT)
5558 return; /* dunno why they're failing this */
5559
5560 reason_code = ssh_pkt_getuint32(pktin);
5561 if (reason_code >= lenof(reasons))
5562 reason_code = 0; /* ensure reasons[reason_code] in range */
5563 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5564 message = dupprintf("Forwarded connection refused by"
5565 " server: %s [%.*s]", reasons[reason_code],
5566 reason_length, reason_string);
5567 logevent(message);
5568 sfree(message);
5569
5570 pfd_close(c->u.pfd.s);
5571
5572 del234(ssh->channels, c);
5573 sfree(c);
5574}
5575
5576static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5577{
5578 unsigned localid;
5579 char *type;
5580 int typelen, want_reply;
5581 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5582 struct ssh_channel *c;
5583 struct Packet *pktout;
5584
5585 localid = ssh_pkt_getuint32(pktin);
5586 ssh_pkt_getstring(pktin, &type, &typelen);
5587 want_reply = ssh2_pkt_getbool(pktin);
5588
5589 /*
5590 * First, check that the channel exists. Otherwise,
5591 * we can instantly disconnect with a rude message.
5592 */
5593 c = find234(ssh->channels, &localid, ssh_channelfind);
5594 if (!c) {
5595 char buf[80];
5596 sprintf(buf, "Received channel request for nonexistent"
5597 " channel %d", localid);
5598 logevent(buf);
5599 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5600 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5601 ssh2_pkt_addstring(pktout, buf);
5602 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5603 ssh2_pkt_send_noqueue(ssh, pktout);
5604 connection_fatal(ssh->frontend, "%s", buf);
5605 ssh_closing((Plug)ssh, NULL, 0, 0);
5606 return;
5607 }
5608
5609 /*
5610 * Having got the channel number, we now look at
5611 * the request type string to see if it's something
5612 * we recognise.
5613 */
5614 if (c == ssh->mainchan) {
5615 /*
5616 * We recognise "exit-status" and "exit-signal" on
5617 * the primary channel.
5618 */
5619 if (typelen == 11 &&
5620 !memcmp(type, "exit-status", 11)) {
5621
5622 ssh->exitcode = ssh_pkt_getuint32(pktin);
5623 logeventf(ssh, "Server sent command exit status %d",
5624 ssh->exitcode);
5625 reply = SSH2_MSG_CHANNEL_SUCCESS;
5626
5627 } else if (typelen == 11 &&
5628 !memcmp(type, "exit-signal", 11)) {
5629
5630 int is_plausible = TRUE, is_int = FALSE;
5631 char *fmt_sig = "", *fmt_msg = "";
5632 char *msg;
5633 int msglen = 0, core = FALSE;
5634 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5635 * provide an `int' for the signal, despite its
5636 * having been a `string' in the drafts since at
5637 * least 2001. (Fixed in session.c 1.147.) Try to
5638 * infer which we can safely parse it as. */
5639 {
5640 unsigned char *p = pktin->body +
5641 pktin->savedpos;
5642 long len = pktin->length - pktin->savedpos;
5643 unsigned long num = GET_32BIT(p); /* what is it? */
5644 /* If it's 0, it hardly matters; assume string */
5645 if (num == 0) {
5646 is_int = FALSE;
5647 } else {
5648 int maybe_int = FALSE, maybe_str = FALSE;
5649#define CHECK_HYPOTHESIS(offset, result) \
5650 do { \
5651 long q = offset; \
5652 if (q >= 0 && q+4 <= len) { \
5653 q = q + 4 + GET_32BIT(p+q); \
5654 if (q >= 0 && q+4 <= len && \
5655 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5656 result = TRUE; \
5657 } \
5658 } while(0)
5659 CHECK_HYPOTHESIS(4+1, maybe_int);
5660 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5661#undef CHECK_HYPOTHESIS
5662 if (maybe_int && !maybe_str)
5663 is_int = TRUE;
5664 else if (!maybe_int && maybe_str)
5665 is_int = FALSE;
5666 else
5667 /* Crikey. Either or neither. Panic. */
5668 is_plausible = FALSE;
5669 }
5670 }
5671 if (is_plausible) {
5672 if (is_int) {
5673 /* Old non-standard OpenSSH. */
5674 int signum = ssh_pkt_getuint32(pktin);
5675 fmt_sig = dupprintf(" %d", signum);
5676 } else {
5677 /* As per the drafts. */
5678 char *sig;
5679 int siglen;
5680 ssh_pkt_getstring(pktin, &sig, &siglen);
5681 /* Signal name isn't supposed to be blank, but
5682 * let's cope gracefully if it is. */
5683 if (siglen) {
5684 fmt_sig = dupprintf(" \"%.*s\"",
5685 siglen, sig);
5686 }
5687 }
5688 core = ssh2_pkt_getbool(pktin);
5689 ssh_pkt_getstring(pktin, &msg, &msglen);
5690 if (msglen) {
5691 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5692 }
5693 /* ignore lang tag */
5694 } /* else don't attempt to parse */
5695 logeventf(ssh, "Server exited on signal%s%s%s",
5696 fmt_sig, core ? " (core dumped)" : "",
5697 fmt_msg);
5698 if (*fmt_sig) sfree(fmt_sig);
5699 if (*fmt_msg) sfree(fmt_msg);
5700 reply = SSH2_MSG_CHANNEL_SUCCESS;
5701
5702 }
5703 } else {
5704 /*
5705 * This is a channel request we don't know
5706 * about, so we now either ignore the request
5707 * or respond with CHANNEL_FAILURE, depending
5708 * on want_reply.
5709 */
5710 reply = SSH2_MSG_CHANNEL_FAILURE;
5711 }
5712 if (want_reply) {
5713 pktout = ssh2_pkt_init(reply);
5714 ssh2_pkt_adduint32(pktout, c->remoteid);
5715 ssh2_pkt_send(ssh, pktout);
5716 }
5717}
5718
5719static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5720{
5721 char *type;
5722 int typelen, want_reply;
5723 struct Packet *pktout;
5724
5725 ssh_pkt_getstring(pktin, &type, &typelen);
5726 want_reply = ssh2_pkt_getbool(pktin);
5727
5728 /*
5729 * We currently don't support any global requests
5730 * at all, so we either ignore the request or
5731 * respond with REQUEST_FAILURE, depending on
5732 * want_reply.
5733 */
5734 if (want_reply) {
5735 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5736 ssh2_pkt_send(ssh, pktout);
5737 }
5738}
5739
5740static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5741{
5742 char *type;
5743 int typelen;
5744 char *peeraddr;
5745 int peeraddrlen;
5746 int peerport;
5747 char *error = NULL;
5748 struct ssh_channel *c;
5749 unsigned remid, winsize, pktsize;
5750 struct Packet *pktout;
5751
5752 ssh_pkt_getstring(pktin, &type, &typelen);
5753 c = snew(struct ssh_channel);
5754 c->ssh = ssh;
5755
5756 remid = ssh_pkt_getuint32(pktin);
5757 winsize = ssh_pkt_getuint32(pktin);
5758 pktsize = ssh_pkt_getuint32(pktin);
5759
5760 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5761 char *addrstr;
5762
5763 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5764 addrstr = snewn(peeraddrlen+1, char);
5765 memcpy(addrstr, peeraddr, peeraddrlen);
5766 addrstr[peeraddrlen] = '\0';
5767 peerport = ssh_pkt_getuint32(pktin);
5768
5769 logeventf(ssh, "Received X11 connect request from %s:%d",
5770 addrstr, peerport);
5771
5772 if (!ssh->X11_fwd_enabled)
5773 error = "X11 forwarding is not enabled";
5774 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5775 ssh->x11auth, addrstr, peerport,
5776 &ssh->cfg) != NULL) {
5777 error = "Unable to open an X11 connection";
5778 } else {
5779 logevent("Opening X11 forward connection succeeded");
5780 c->type = CHAN_X11;
5781 }
5782
5783 sfree(addrstr);
5784 } else if (typelen == 15 &&
5785 !memcmp(type, "forwarded-tcpip", 15)) {
5786 struct ssh_rportfwd pf, *realpf;
5787 char *dummy;
5788 int dummylen;
5789 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5790 pf.sport = ssh_pkt_getuint32(pktin);
5791 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5792 peerport = ssh_pkt_getuint32(pktin);
5793 realpf = find234(ssh->rportfwds, &pf, NULL);
5794 logeventf(ssh, "Received remote port %d open request "
5795 "from %s:%d", pf.sport, peeraddr, peerport);
5796 if (realpf == NULL) {
5797 error = "Remote port is not recognised";
5798 } else {
5799 const char *e = pfd_newconnect(&c->u.pfd.s,
5800 realpf->dhost,
5801 realpf->dport, c,
5802 &ssh->cfg);
5803 logeventf(ssh, "Attempting to forward remote port to "
5804 "%s:%d", realpf->dhost, realpf->dport);
5805 if (e != NULL) {
5806 logeventf(ssh, "Port open failed: %s", e);
5807 error = "Port open failed";
5808 } else {
5809 logevent("Forwarded port opened successfully");
5810 c->type = CHAN_SOCKDATA;
5811 }
5812 }
5813 } else if (typelen == 22 &&
5814 !memcmp(type, "auth-agent@openssh.com", 3)) {
5815 if (!ssh->agentfwd_enabled)
5816 error = "Agent forwarding is not enabled";
5817 else {
5818 c->type = CHAN_AGENT; /* identify channel type */
5819 c->u.a.lensofar = 0;
5820 }
5821 } else {
5822 error = "Unsupported channel type requested";
5823 }
5824
5825 c->remoteid = remid;
5826 if (error) {
5827 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5828 ssh2_pkt_adduint32(pktout, c->remoteid);
5829 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5830 ssh2_pkt_addstring(pktout, error);
5831 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5832 ssh2_pkt_send(ssh, pktout);
5833 logeventf(ssh, "Rejected channel open: %s", error);
5834 sfree(c);
5835 } else {
5836 c->localid = alloc_channel_id(ssh);
5837 c->closes = 0;
5838 c->v.v2.locwindow = OUR_V2_WINSIZE;
5839 c->v.v2.remwindow = winsize;
5840 c->v.v2.remmaxpkt = pktsize;
5841 bufchain_init(&c->v.v2.outbuffer);
5842 add234(ssh->channels, c);
5843 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5844 ssh2_pkt_adduint32(pktout, c->remoteid);
5845 ssh2_pkt_adduint32(pktout, c->localid);
5846 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5847 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5848 ssh2_pkt_send(ssh, pktout);
5849 }
5850}
5851
783415f8 5852/*
7cca0d81 5853 * Handle the SSH2 userauth and connection layers.
5854 */
ff3187f6 5855static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5856 struct Packet *pktin)
7cca0d81 5857{
51470298 5858 struct do_ssh2_authconn_state {
5859 enum {
5860 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5861 AUTH_PASSWORD,
5862 AUTH_KEYBOARD_INTERACTIVE
5863 } method;
5864 enum {
5865 AUTH_TYPE_NONE,
5866 AUTH_TYPE_PUBLICKEY,
5867 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5868 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5869 AUTH_TYPE_PASSWORD,
5870 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5871 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5872 } type;
5873 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5874 int tried_pubkey_config, tried_agent, tried_keyb_inter;
5875 int kbd_inter_running;
5876 int we_are_in;
5877 int num_prompts, curr_prompt, echo;
5878 char username[100];
5879 int got_username;
85fdbe25 5880 char pwprompt[512];
51470298 5881 char password[100];
5882 void *publickey_blob;
5883 int publickey_bloblen;
5884 unsigned char request[5], *response, *p;
5885 int responselen;
5886 int keyi, nkeys;
5887 int authed;
5888 char *pkblob, *alg, *commentp;
5889 int pklen, alglen, commentlen;
5890 int siglen, retlen, len;
5891 char *q, *agentreq, *ret;
5892 int try_send;
73feed4f 5893 int num_env, env_left, env_ok;
ff3187f6 5894 struct Packet *pktout;
51470298 5895 };
5896 crState(do_ssh2_authconn_state);
5897
5898 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 5899
7cca0d81 5900 /*
5901 * Request userauth protocol, and await a response to it.
5902 */
ff3187f6 5903 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5904 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5905 ssh2_pkt_send(ssh, s->pktout);
5906 crWaitUntilV(pktin);
5907 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 5908 bombout(("Server refused user authentication protocol"));
7ffdbc1a 5909 crStopV;
8d5de777 5910 }
7cca0d81 5911
5912 /*
1408a877 5913 * We repeat this whole loop, including the username prompt,
5914 * until we manage a successful authentication. If the user
51470298 5915 * types the wrong _password_, they can be sent back to the
5916 * beginning to try another username, if this is configured on.
5917 * (If they specify a username in the config, they are never
5918 * asked, even if they do give a wrong password.)
1408a877 5919 *
5920 * I think this best serves the needs of
5921 *
5922 * - the people who have no configuration, no keys, and just
5923 * want to try repeated (username,password) pairs until they
5924 * type both correctly
5925 *
5926 * - people who have keys and configuration but occasionally
5927 * need to fall back to passwords
5928 *
5929 * - people with a key held in Pageant, who might not have
5930 * logged in to a particular machine before; so they want to
5931 * type a username, and then _either_ their key will be
5932 * accepted, _or_ they will type a password. If they mistype
5933 * the username they will want to be able to get back and
5934 * retype it!
7cca0d81 5935 */
51470298 5936 s->username[0] = '\0';
5937 s->got_username = FALSE;
1408a877 5938 do {
1408a877 5939 /*
5940 * Get a username.
5941 */
86916870 5942 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 5943 /*
5944 * We got a username last time round this loop, and
5945 * with change_username turned off we don't try to get
5946 * it again.
5947 */
aa09f7d0 5948 } else if (!*ssh->cfg.username) {
c0a81592 5949 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 5950 if (!ssh_get_line("login as: ",
51470298 5951 s->username, sizeof(s->username), FALSE)) {
32874aea 5952 /*
5953 * get_line failed to get a username.
5954 * Terminate.
5955 */
5956 logevent("No username provided. Abandoning session.");
3bb2f322 5957 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5958 crStopV;
32874aea 5959 }
5960 } else {
51470298 5961 int ret; /* need not be saved across crReturn */
5962 c_write_str(ssh, "login as: ");
5963 ssh->send_ok = 1;
5964 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 5965 do {
ff3187f6 5966 crWaitUntilV(!pktin);
51470298 5967 ret = process_userpass_input(ssh, in, inlen);
0405e71f 5968 } while (ret == 0);
5969 if (ret < 0)
5970 cleanup_exit(0);
4ca0c9d1 5971 c_write_str(ssh, "\r\n");
32874aea 5972 }
51470298 5973 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 5974 } else {
57356d63 5975 char *stuff;
86916870 5976 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 5977 s->username[sizeof(s->username)-1] = '\0';
65a22376 5978 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 5979 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 5980 c_write_str(ssh, stuff);
57356d63 5981 sfree(stuff);
7cca0d81 5982 }
5983 }
51470298 5984 s->got_username = TRUE;
7cca0d81 5985
65a22376 5986 /*
1408a877 5987 * Send an authentication request using method "none": (a)
5988 * just in case it succeeds, and (b) so that we know what
5989 * authentication methods we can usefully try next.
65a22376 5990 */
51470298 5991 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5992
ff3187f6 5993 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5994 ssh2_pkt_addstring(s->pktout, s->username);
5995 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
5996 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5997 ssh2_pkt_send(ssh, s->pktout);
51470298 5998 s->type = AUTH_TYPE_NONE;
5999 s->gotit = FALSE;
6000 s->we_are_in = FALSE;
6001
6002 s->tried_pubkey_config = FALSE;
6003 s->tried_agent = FALSE;
6004 s->tried_keyb_inter = FALSE;
6005 s->kbd_inter_running = FALSE;
86916870 6006 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 6007 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 6008 int keytype;
6c6d9ed9 6009 logeventf(ssh, "Reading private key file \"%.150s\"",
6010 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 6011 keytype = key_type(&ssh->cfg.keyfile);
51470298 6012 if (keytype == SSH_KEYTYPE_SSH2) {
6013 s->publickey_blob =
9a30e26b 6014 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 6015 &s->publickey_bloblen, NULL);
51470298 6016 } else {
57356d63 6017 char *msgbuf;
c2ad7d0d 6018 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 6019 key_type_to_str(keytype));
57356d63 6020 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 6021 " (%s)\r\n",
6022 filename_to_str(&ssh->cfg.keyfile),
57356d63 6023 key_type_to_str(keytype));
51470298 6024 c_write_str(ssh, msgbuf);
57356d63 6025 sfree(msgbuf);
51470298 6026 s->publickey_blob = NULL;
231ee168 6027 }
396778f1 6028 } else
51470298 6029 s->publickey_blob = NULL;
65a22376 6030
1408a877 6031 while (1) {
6032 /*
6033 * Wait for the result of the last authentication request.
6034 */
51470298 6035 if (!s->gotit)
ff3187f6 6036 crWaitUntilV(pktin);
6037 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 6038 char *banner;
6039 int size;
6040 /*
6041 * Don't show the banner if we're operating in
6042 * non-verbose non-interactive mode. (It's probably
6043 * a script, which means nobody will read the
6044 * banner _anyway_, and moreover the printing of
6045 * the banner will screw up processing on the
6046 * output of (say) plink.)
6047 */
6048 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 6049 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 6050 if (banner)
51470298 6051 c_write_untrusted(ssh, banner, size);
32874aea 6052 }
ff3187f6 6053 crWaitUntilV(pktin);
1408a877 6054 }
ff3187f6 6055 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6056 logevent("Access granted");
51470298 6057 s->we_are_in = TRUE;
1408a877 6058 break;
6059 }
65a22376 6060
51470298 6061 if (s->kbd_inter_running &&
ff3187f6 6062 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 6063 /*
45068b27 6064 * This is either a further set-of-prompts packet
6065 * in keyboard-interactive authentication, or it's
6066 * the same one and we came back here with `gotit'
6067 * set. In the former case, we must reset the
6068 * curr_prompt variable.
b3186d64 6069 */
51470298 6070 if (!s->gotit)
6071 s->curr_prompt = 0;
ff3187f6 6072 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 6073 bombout(("Strange packet received during authentication: type %d",
ff3187f6 6074 pktin->type));
7ffdbc1a 6075 crStopV;
65a22376 6076 }
6077
51470298 6078 s->gotit = FALSE;
65a22376 6079
1408a877 6080 /*
6081 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6082 * we can look at the string in it and know what we can
6083 * helpfully try next.
6084 */
ff3187f6 6085 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6086 char *methods;
6087 int methlen;
ff3187f6 6088 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 6089 s->kbd_inter_running = FALSE;
ff3187f6 6090 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6091 /*
6092 * We have received an unequivocal Access
6093 * Denied. This can translate to a variety of
6094 * messages:
6095 *
6096 * - if we'd just tried "none" authentication,
6097 * it's not worth printing anything at all
6098 *
6099 * - if we'd just tried a public key _offer_,
6100 * the message should be "Server refused our
6101 * key" (or no message at all if the key
6102 * came from Pageant)
6103 *
6104 * - if we'd just tried anything else, the
6105 * message really should be "Access denied".
6106 *
6107 * Additionally, if we'd just tried password
6108 * authentication, we should break out of this
6109 * whole loop so as to go back to the username
91f57d1f 6110 * prompt (iff we're configured to allow
6111 * username change attempts).
1408a877 6112 */
51470298 6113 if (s->type == AUTH_TYPE_NONE) {
1408a877 6114 /* do nothing */
51470298 6115 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6116 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6117 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6118 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6119 logevent("Server refused public key");
51470298 6120 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6121 /* server declined keyboard-interactive; ignore */
1408a877 6122 } else {
51470298 6123 c_write_str(ssh, "Access denied\r\n");
1408a877 6124 logevent("Access denied");
91f57d1f 6125 if (s->type == AUTH_TYPE_PASSWORD &&
6126 ssh->cfg.change_username) {
6c9dce7c 6127 /* XXX perhaps we should allow
6128 * keyboard-interactive to do this too? */
51470298 6129 s->we_are_in = FALSE;
1408a877 6130 break;
6131 }
6132 }
6133 } else {
51470298 6134 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6135 logevent("Further authentication required");
6136 }
65a22376 6137
51470298 6138 s->can_pubkey =
32874aea 6139 in_commasep_string("publickey", methods, methlen);
51470298 6140 s->can_passwd =
32874aea 6141 in_commasep_string("password", methods, methlen);
86916870 6142 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6143 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6144 }
65a22376 6145
51470298 6146 s->method = 0;
6147 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 6148 s->need_pw = FALSE;
65a22376 6149
0405e71f 6150 /*
6151 * Most password/passphrase prompts will be
6152 * non-echoing, so we set this to 0 by default.
6153 * Exception is that some keyboard-interactive prompts
6154 * can be echoing, in which case we'll set this to 1.
6155 */
51470298 6156 s->echo = 0;
0405e71f 6157
51470298 6158 if (!s->method && s->can_pubkey &&
6159 agent_exists() && !s->tried_agent) {
1983e559 6160 /*
6161 * Attempt public-key authentication using Pageant.
6162 */
1983e559 6163 void *r;
51470298 6164 s->authed = FALSE;
1983e559 6165
51470298 6166 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6167 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6168
51470298 6169 s->tried_agent = TRUE;
1983e559 6170
6171 logevent("Pageant is running. Requesting keys.");
6172
6173 /* Request the keys held by the agent. */
51470298 6174 PUT_32BIT(s->request, 1);
6175 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 6176 if (!agent_query(s->request, 5, &r, &s->responselen,
6177 ssh_agent_callback, ssh)) {
6178 do {
6179 crReturnV;
ff3187f6 6180 if (pktin) {
839f10db 6181 bombout(("Unexpected data from server while"
6182 " waiting for agent response"));
6183 crStopV;
6184 }
ff3187f6 6185 } while (pktin || inlen > 0);
839f10db 6186 r = ssh->agent_response;
6187 s->responselen = ssh->agent_response_len;
6188 }
51470298 6189 s->response = (unsigned char *) r;
6190 if (s->response && s->responselen >= 5 &&
6191 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6192 s->p = s->response + 5;
6193 s->nkeys = GET_32BIT(s->p);
6194 s->p += 4;
32874aea 6195 {
6196 char buf[64];
51470298 6197 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 6198 logevent(buf);
6199 }
51470298 6200 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 6201 void *vret;
1983e559 6202
32874aea 6203 {
6204 char buf[64];
51470298 6205 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 6206 logevent(buf);
6207 }
51470298 6208 s->pklen = GET_32BIT(s->p);
6209 s->p += 4;
6210 if (s->publickey_blob &&
6211 s->pklen == s->publickey_bloblen &&
6212 !memcmp(s->p, s->publickey_blob,
6213 s->publickey_bloblen)) {
396778f1 6214 logevent("This key matches configured key file");
51470298 6215 s->tried_pubkey_config = 1;
396778f1 6216 }
d8baa528 6217 s->pkblob = (char *)s->p;
51470298 6218 s->p += s->pklen;
6219 s->alglen = GET_32BIT(s->pkblob);
6220 s->alg = s->pkblob + 4;
6221 s->commentlen = GET_32BIT(s->p);
6222 s->p += 4;
d8baa528 6223 s->commentp = (char *)s->p;
51470298 6224 s->p += s->commentlen;
ff3187f6 6225 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6226 ssh2_pkt_addstring(s->pktout, s->username);
6227 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6228 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6229 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6230 ssh2_pkt_addstring_start(s->pktout);
6231 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6232 ssh2_pkt_addstring_start(s->pktout);
6233 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6234 ssh2_pkt_send(ssh, s->pktout);
6235
6236 crWaitUntilV(pktin);
6237 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6238 logevent("Key refused");
6239 continue;
6240 }
6241
32874aea 6242 if (flags & FLAG_VERBOSE) {
51470298 6243 c_write_str(ssh, "Authenticating with "
6244 "public key \"");
6245 c_write(ssh, s->commentp, s->commentlen);
6246 c_write_str(ssh, "\" from agent\r\n");
32874aea 6247 }
1983e559 6248
6249 /*
6250 * Server is willing to accept the key.
6251 * Construct a SIGN_REQUEST.
6252 */
ff3187f6 6253 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6254 ssh2_pkt_addstring(s->pktout, s->username);
6255 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6256 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6257 ssh2_pkt_addbool(s->pktout, TRUE);
6258 ssh2_pkt_addstring_start(s->pktout);
6259 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6260 ssh2_pkt_addstring_start(s->pktout);
6261 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6262
6263 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 6264 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6265 s->siglen -= 4;
51470298 6266 s->len = 1; /* message type */
6267 s->len += 4 + s->pklen; /* key blob */
6268 s->len += 4 + s->siglen; /* data to sign */
6269 s->len += 4; /* flags */
3d88e64d 6270 s->agentreq = snewn(4 + s->len, char);
51470298 6271 PUT_32BIT(s->agentreq, s->len);
6272 s->q = s->agentreq + 4;
6273 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6274 PUT_32BIT(s->q, s->pklen);
6275 s->q += 4;
6276 memcpy(s->q, s->pkblob, s->pklen);
6277 s->q += s->pklen;
6278 PUT_32BIT(s->q, s->siglen);
6279 s->q += 4;
1983e559 6280 /* Now the data to be signed... */
dda87a28 6281 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6282 PUT_32BIT(s->q, 20);
6283 s->q += 4;
6284 }
51470298 6285 memcpy(s->q, ssh->v2_session_id, 20);
6286 s->q += 20;
ff3187f6 6287 memcpy(s->q, s->pktout->data + 5,
6288 s->pktout->length - 5);
6289 s->q += s->pktout->length - 5;
1983e559 6290 /* And finally the (zero) flags word. */
51470298 6291 PUT_32BIT(s->q, 0);
839f10db 6292 if (!agent_query(s->agentreq, s->len + 4,
6293 &vret, &s->retlen,
6294 ssh_agent_callback, ssh)) {
6295 do {
6296 crReturnV;
ff3187f6 6297 if (pktin) {
839f10db 6298 bombout(("Unexpected data from server"
6299 " while waiting for agent"
6300 " response"));
6301 crStopV;
6302 }
ff3187f6 6303 } while (pktin || inlen > 0);
839f10db 6304 vret = ssh->agent_response;
6305 s->retlen = ssh->agent_response_len;
6306 }
51470298 6307 s->ret = vret;
6308 sfree(s->agentreq);
6309 if (s->ret) {
6310 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 6311 logevent("Sending Pageant's response");
ff3187f6 6312 ssh2_add_sigblob(ssh, s->pktout,
6313 s->pkblob, s->pklen,
51470298 6314 s->ret + 9,
6315 GET_32BIT(s->ret + 5));
ff3187f6 6316 ssh2_pkt_send(ssh, s->pktout);
51470298 6317 s->authed = TRUE;
1983e559 6318 break;
6319 } else {
32874aea 6320 logevent
6321 ("Pageant failed to answer challenge");
51470298 6322 sfree(s->ret);
1983e559 6323 }
6324 }
6325 }
51470298 6326 if (s->authed)
1983e559 6327 continue;
6328 }
29b1d0b3 6329 sfree(s->response);
1983e559 6330 }
6331
51470298 6332 if (!s->method && s->can_pubkey && s->publickey_blob
6333 && !s->tried_pubkey_config) {
1408a877 6334 unsigned char *pub_blob;
6335 char *algorithm, *comment;
6336 int pub_blob_len;
65a22376 6337
51470298 6338 s->tried_pubkey_config = TRUE;
65a22376 6339
51470298 6340 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6341 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6342
65a22376 6343 /*
1408a877 6344 * Try the public key supplied in the configuration.
6345 *
6346 * First, offer the public blob to see if the server is
6347 * willing to accept it.
65a22376 6348 */
d8baa528 6349 pub_blob =
9a30e26b 6350 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6351 &algorithm,
222d54dc 6352 &pub_blob_len,
6353 NULL);
1408a877 6354 if (pub_blob) {
ff3187f6 6355 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6356 ssh2_pkt_addstring(s->pktout, s->username);
6357 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6358 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6359 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6360 ssh2_pkt_addstring(s->pktout, algorithm);
6361 ssh2_pkt_addstring_start(s->pktout);
6362 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6363 pub_blob_len);
ff3187f6 6364 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6365 logevent("Offered public key");
1408a877 6366
ff3187f6 6367 crWaitUntilV(pktin);
6368 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6369 s->gotit = TRUE;
6370 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6371 continue; /* key refused; give up on it */
1408a877 6372 }
65a22376 6373
1408a877 6374 logevent("Offer of public key accepted");
65a22376 6375 /*
1408a877 6376 * Actually attempt a serious authentication using
6377 * the key.
65a22376 6378 */
9a30e26b 6379 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6380 sprintf(s->pwprompt,
32874aea 6381 "Passphrase for key \"%.100s\": ",
6382 comment);
51470298 6383 s->need_pw = TRUE;
1408a877 6384 } else {
51470298 6385 s->need_pw = FALSE;
1408a877 6386 }
4e520718 6387 if (flags & FLAG_VERBOSE) {
6388 c_write_str(ssh, "Authenticating with public key \"");
6389 c_write_str(ssh, comment);
6390 c_write_str(ssh, "\"\r\n");
6391 }
51470298 6392 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6393 }
1408a877 6394 }
6395
51470298 6396 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
6397 s->method = AUTH_KEYBOARD_INTERACTIVE;
6398 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6399 s->tried_keyb_inter = TRUE;
af659722 6400
51470298 6401 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6402 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6403
ff3187f6 6404 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6405 ssh2_pkt_addstring(s->pktout, s->username);
6406 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6407 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6408 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6409 ssh2_pkt_addstring(s->pktout, "");
6410 ssh2_pkt_send(ssh, s->pktout);
6411
6412 crWaitUntilV(pktin);
6413 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6414 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6415 s->gotit = TRUE;
af659722 6416 logevent("Keyboard-interactive authentication refused");
51470298 6417 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 6418 continue;
6419 }
6420
51470298 6421 s->kbd_inter_running = TRUE;
6422 s->curr_prompt = 0;
af659722 6423 }
6424
51470298 6425 if (s->kbd_inter_running) {
6426 s->method = AUTH_KEYBOARD_INTERACTIVE;
6427 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6428 s->tried_keyb_inter = TRUE;
af659722 6429
51470298 6430 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6431 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6432
51470298 6433 if (s->curr_prompt == 0) {
45068b27 6434 /*
6435 * We've got a fresh USERAUTH_INFO_REQUEST.
6436 * Display header data, and start going through
6437 * the prompts.
6438 */
6439 char *name, *inst, *lang;
6440 int name_len, inst_len, lang_len;
6441
ff3187f6 6442 ssh_pkt_getstring(pktin, &name, &name_len);
6443 ssh_pkt_getstring(pktin, &inst, &inst_len);
6444 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6445 if (name_len > 0) {
51470298 6446 c_write_untrusted(ssh, name, name_len);
6447 c_write_str(ssh, "\r\n");
45068b27 6448 }
6449 if (inst_len > 0) {
51470298 6450 c_write_untrusted(ssh, inst, inst_len);
6451 c_write_str(ssh, "\r\n");
45068b27 6452 }
ff3187f6 6453 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6454 }
af659722 6455
45068b27 6456 /*
6457 * If there are prompts remaining in the packet,
6458 * display one and get a response.
6459 */
51470298 6460 if (s->curr_prompt < s->num_prompts) {
45068b27 6461 char *prompt;
6462 int prompt_len;
af659722 6463
ff3187f6 6464 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6465 if (prompt_len > 0) {
85fdbe25 6466 static const char trunc[] = "<prompt truncated>: ";
6467 static const int prlen = sizeof(s->pwprompt) -
6468 lenof(trunc);
6469 if (prompt_len > prlen) {
6470 memcpy(s->pwprompt, prompt, prlen);
6471 strcpy(s->pwprompt + prlen, trunc);
6472 } else {
6473 memcpy(s->pwprompt, prompt, prompt_len);
6474 s->pwprompt[prompt_len] = '\0';
6475 }
45068b27 6476 } else {
51470298 6477 strcpy(s->pwprompt,
45068b27 6478 "<server failed to send prompt>: ");
6479 }
ff3187f6 6480 s->echo = ssh2_pkt_getbool(pktin);
51470298 6481 s->need_pw = TRUE;
45068b27 6482 } else
51470298 6483 s->need_pw = FALSE;
af659722 6484 }
6485
51470298 6486 if (!s->method && s->can_passwd) {
6487 s->method = AUTH_PASSWORD;
6488 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6489 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6490 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6491 ssh->savedhost);
6492 s->need_pw = TRUE;
1408a877 6493 }
6494
51470298 6495 if (s->need_pw) {
fa17a66e 6496 if (ssh_get_line) {
51470298 6497 if (!ssh_get_line(s->pwprompt, s->password,
6498 sizeof(s->password), TRUE)) {
1408a877 6499 /*
fa17a66e 6500 * get_line failed to get a password (for
6501 * example because one was supplied on the
6502 * command line which has already failed to
6503 * work). Terminate.
1408a877 6504 */
ff3187f6 6505 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6506 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6507 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6508 " to try");
ff3187f6 6509 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6510 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6511 logevent("Unable to authenticate");
a8327734 6512 connection_fatal(ssh->frontend,
6513 "Unable to authenticate");
3bb2f322 6514 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6515 crStopV;
1408a877 6516 }
6517 } else {
51470298 6518 int ret; /* need not be saved across crReturn */
6519 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6520 ssh->send_ok = 1;
1408a877 6521
51470298 6522 setup_userpass_input(ssh, s->password,
6523 sizeof(s->password), s->echo);
0405e71f 6524 do {
ff3187f6 6525 crWaitUntilV(!pktin);
51470298 6526 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6527 } while (ret == 0);
6528 if (ret < 0)
6529 cleanup_exit(0);
51470298 6530 c_write_str(ssh, "\r\n");
65a22376 6531 }
65a22376 6532 }
65a22376 6533
51470298 6534 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6535 /*
6536 * We have our passphrase. Now try the actual authentication.
6537 */
6538 struct ssh2_userkey *key;
222d54dc 6539 const char *error = NULL;
65a22376 6540
222d54dc 6541 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6542 &error);
1408a877 6543 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6544 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6545 c_write_str(ssh, "Wrong passphrase\r\n");
6546 s->tried_pubkey_config = FALSE;
1408a877 6547 } else {
222d54dc 6548 c_write_str(ssh, "Unable to load private key (");
6549 c_write_str(ssh, error);
6550 c_write_str(ssh, ")\r\n");
51470298 6551 s->tried_pubkey_config = TRUE;
1408a877 6552 }
6553 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6554 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6555 ssh2_pkt_addstring(s->pktout, s->username);
6556 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6557 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6558 ssh2_pkt_send(ssh, s->pktout);
51470298 6559 s->type = AUTH_TYPE_NONE;
1408a877 6560 } else {
1dd353b5 6561 unsigned char *pkblob, *sigblob, *sigdata;
6562 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6563 int p;
65a22376 6564
1408a877 6565 /*
6566 * We have loaded the private key and the server
6567 * has announced that it's willing to accept it.
6568 * Hallelujah. Generate a signature and send it.
6569 */
ff3187f6 6570 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6571 ssh2_pkt_addstring(s->pktout, s->username);
6572 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6573 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6574 ssh2_pkt_addbool(s->pktout, TRUE);
6575 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6576 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6577 ssh2_pkt_addstring_start(s->pktout);
6578 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6579
6580 /*
6581 * The data to be signed is:
6582 *
6583 * string session-id
6584 *
6585 * followed by everything so far placed in the
6586 * outgoing packet.
6587 */
ff3187f6 6588 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6589 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6590 sigdata_len -= 4;
92d60585 6591 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6592 p = 0;
6593 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6594 PUT_32BIT(sigdata+p, 20);
6595 p += 4;
6596 }
6597 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6598 memcpy(sigdata+p, s->pktout->data + 5,
6599 s->pktout->length - 5);
6600 p += s->pktout->length - 5;
dda87a28 6601 assert(p == sigdata_len);
d8baa528 6602 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6603 sigdata_len, &sigblob_len);
ff3187f6 6604 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6605 sigblob, sigblob_len);
6606 sfree(pkblob);
6607 sfree(sigblob);
1408a877 6608 sfree(sigdata);
6609
ff3187f6 6610 ssh2_pkt_send(ssh, s->pktout);
51470298 6611 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6612 key->alg->freekey(key->data);
1408a877 6613 }
51470298 6614 } else if (s->method == AUTH_PASSWORD) {
65a22376 6615 /*
1408a877 6616 * We send the password packet lumped tightly together with
6617 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6618 * string long enough to make the total length of the two
6619 * packets constant. This should ensure that a passive
6620 * listener doing traffic analyis can't work out the length
6621 * of the password.
6622 *
6623 * For this to work, we need an assumption about the
6624 * maximum length of the password packet. I think 256 is
6625 * pretty conservative. Anyone using a password longer than
6626 * that probably doesn't have much to worry about from
6627 * people who find out how long their password is!
65a22376 6628 */
ff3187f6 6629 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6630 ssh2_pkt_addstring(s->pktout, s->username);
6631 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6632 ssh2_pkt_addstring(s->pktout, "password");
6633 ssh2_pkt_addbool(s->pktout, FALSE);
6634 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6635 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 6636 memset(s->password, 0, sizeof(s->password));
ff3187f6 6637 end_log_omission(ssh, s->pktout);
6638 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6639 /*
1408a877 6640 * We'll include a string that's an exact multiple of the
6641 * cipher block size. If the cipher is NULL for some
6642 * reason, we don't do this trick at all because we gain
6643 * nothing by it.
65a22376 6644 */
51470298 6645 if (ssh->cscipher) {
32874aea 6646 int stringlen, i;
6647
51470298 6648 stringlen = (256 - ssh->deferred_len);
6649 stringlen += ssh->cscipher->blksize - 1;
6650 stringlen -= (stringlen % ssh->cscipher->blksize);
6651 if (ssh->cscomp) {
32874aea 6652 /*
6653 * Temporarily disable actual compression,
6654 * so we can guarantee to get this string
6655 * exactly the length we want it. The
6656 * compression-disabling routine should
6657 * return an integer indicating how many
6658 * bytes we should adjust our string length
6659 * by.
6660 */
5366aed8 6661 stringlen -=
6662 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 6663 }
ff3187f6 6664 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6665 ssh2_pkt_addstring_start(s->pktout);
6e9e9520 6666 for (i = 0; i < stringlen; i++) {
32874aea 6667 char c = (char) random_byte();
ff3187f6 6668 ssh2_pkt_addstring_data(s->pktout, &c, 1);
65a22376 6669 }
ff3187f6 6670 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6671 }
51470298 6672 ssh_pkt_defersend(ssh);
0d43337a 6673 logevent("Sent password");
51470298 6674 s->type = AUTH_TYPE_PASSWORD;
6675 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6676 if (s->curr_prompt == 0) {
ff3187f6 6677 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6678 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 6679 }
51470298 6680 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 6681 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6682 ssh2_pkt_addstring(s->pktout, s->password);
51470298 6683 memset(s->password, 0, sizeof(s->password));
ff3187f6 6684 end_log_omission(ssh, s->pktout);
51470298 6685 s->curr_prompt++;
45068b27 6686 }
51470298 6687 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 6688 ssh2_pkt_send(ssh, s->pktout);
45068b27 6689 } else {
6690 /*
6691 * If there are prompts remaining, we set
6692 * `gotit' so that we won't attempt to get
6693 * another packet. Then we go back round the
6694 * loop and will end up retrieving another
6695 * prompt out of the existing packet. Funky or
6696 * what?
6697 */
51470298 6698 s->gotit = TRUE;
45068b27 6699 }
51470298 6700 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 6701 } else {
51470298 6702 c_write_str(ssh, "No supported authentication methods"
6703 " left to try!\r\n");
6704 logevent("No supported authentications offered."
6705 " Disconnecting");
ff3187f6 6706 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6707 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6708 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 6709 " methods available");
ff3187f6 6710 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6711 ssh2_pkt_send_noqueue(ssh, s->pktout);
3bb2f322 6712 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6713 crStopV;
65a22376 6714 }
65a22376 6715 }
51470298 6716 } while (!s->we_are_in);
7cca0d81 6717
6718 /*
6719 * Now we're authenticated for the connection protocol. The
6720 * connection protocol will automatically have started at this
6721 * point; there's no need to send SERVICE_REQUEST.
6722 */
6723
0ed48730 6724 ssh->channels = newtree234(ssh_channelcmp);
6725
7cca0d81 6726 /*
b09eaa88 6727 * Set up handlers for some connection protocol messages, so we
6728 * don't have to handle them repeatedly in this coroutine.
6729 */
6730 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6731 ssh2_msg_channel_window_adjust;
51df0ab5 6732 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6733 ssh2_msg_global_request;
b09eaa88 6734
6735 /*
0ed48730 6736 * Create the main session channel.
7cca0d81 6737 */
0ed48730 6738 if (!ssh->cfg.ssh_no_shell) {
6739 ssh->mainchan = snew(struct ssh_channel);
6740 ssh->mainchan->ssh = ssh;
6741 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 6742 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6743 ssh2_pkt_addstring(s->pktout, "session");
6744 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 6745 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 6746 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6747 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6748 ssh2_pkt_send(ssh, s->pktout);
6749 crWaitUntilV(pktin);
6750 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 6751 bombout(("Server refused to open a session"));
6752 crStopV;
6753 /* FIXME: error data comes back in FAILURE packet */
6754 }
ff3187f6 6755 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 6756 bombout(("Server's channel confirmation cited wrong channel"));
6757 crStopV;
6758 }
ff3187f6 6759 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 6760 ssh->mainchan->type = CHAN_MAINSESSION;
6761 ssh->mainchan->closes = 0;
ff3187f6 6762 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6763 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 6764 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6765 add234(ssh->channels, ssh->mainchan);
62638676 6766 update_specials_menu(ssh->frontend);
0ed48730 6767 logevent("Opened channel for session");
6768 } else
6769 ssh->mainchan = NULL;
7cca0d81 6770
6771 /*
51df0ab5 6772 * Now we have a channel, make dispatch table entries for
6773 * general channel-based messages.
6774 */
6775 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6776 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6777 ssh2_msg_channel_data;
6778 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6779 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6780 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6781 ssh2_msg_channel_open_confirmation;
6782 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6783 ssh2_msg_channel_open_failure;
6784 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6785 ssh2_msg_channel_request;
6786 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6787 ssh2_msg_channel_open;
6788
6789 /*
783415f8 6790 * Potentially enable X11 forwarding.
6791 */
0ed48730 6792 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 6793 char proto[20], data[64];
6794 logevent("Requesting X11 forwarding");
302121de 6795 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 6796 data, sizeof(data), ssh->cfg.x11_auth);
6797 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 6798 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6799 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6800 ssh2_pkt_addstring(s->pktout, "x11-req");
6801 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6802 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6803 ssh2_pkt_addstring(s->pktout, proto);
6804 ssh2_pkt_addstring(s->pktout, data);
6805 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6806 ssh2_pkt_send(ssh, s->pktout);
32874aea 6807
b09eaa88 6808 crWaitUntilV(pktin);
32874aea 6809
ff3187f6 6810 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6811 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6812 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 6813 " packet type %d", pktin->type));
7ffdbc1a 6814 crStopV;
32874aea 6815 }
6816 logevent("X11 forwarding refused");
6817 } else {
6818 logevent("X11 forwarding enabled");
51470298 6819 ssh->X11_fwd_enabled = TRUE;
32874aea 6820 }
783415f8 6821 }
6822
6823 /*
bc240b21 6824 * Enable port forwardings.
6825 */
06fadff5 6826 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 6827
6828 /*
36c2a3e9 6829 * Potentially enable agent forwarding.
6830 */
0ed48730 6831 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6832 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6833 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6834 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6835 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6836 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6837 ssh2_pkt_send(ssh, s->pktout);
32874aea 6838
b09eaa88 6839 crWaitUntilV(pktin);
32874aea 6840
ff3187f6 6841 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6842 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6843 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6844 " packet type %d", pktin->type));
7ffdbc1a 6845 crStopV;
32874aea 6846 }
6847 logevent("Agent forwarding refused");
6848 } else {
6849 logevent("Agent forwarding enabled");
51470298 6850 ssh->agentfwd_enabled = TRUE;
32874aea 6851 }
36c2a3e9 6852 }
6853
6854 /*
7cca0d81 6855 * Now allocate a pty for the session.
6856 */
0ed48730 6857 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6858 /* Unpick the terminal-speed string. */
6859 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6860 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6861 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6862 /* Build the pty request. */
ff3187f6 6863 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6864 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6865 ssh2_pkt_addstring(s->pktout, "pty-req");
6866 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6867 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6868 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6869 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6870 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6871 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6872 ssh2_pkt_addstring_start(s->pktout);
6873 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6874 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6875 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6876 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6877 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6878 ssh2_pkt_send(ssh, s->pktout);
51470298 6879 ssh->state = SSH_STATE_INTERMED;
32874aea 6880
b09eaa88 6881 crWaitUntilV(pktin);
32874aea 6882
ff3187f6 6883 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6884 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6885 bombout(("Unexpected response to pty request:"
ff3187f6 6886 " packet type %d", pktin->type));
7ffdbc1a 6887 crStopV;
32874aea 6888 }
51470298 6889 c_write_str(ssh, "Server refused to allocate pty\r\n");
6890 ssh->editing = ssh->echoing = 1;
32874aea 6891 } else {
a5dd8467 6892 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 6893 ssh->ospeed, ssh->ispeed);
32874aea 6894 }
0965bee0 6895 } else {
51470298 6896 ssh->editing = ssh->echoing = 1;
7cca0d81 6897 }
6898
6899 /*
73feed4f 6900 * Send environment variables.
6901 *
6902 * Simplest thing here is to send all the requests at once, and
6903 * then wait for a whole bunch of successes or failures.
6904 */
6905 if (ssh->mainchan && *ssh->cfg.environmt) {
6906 char *e = ssh->cfg.environmt;
6907 char *var, *varend, *val;
6908
6909 s->num_env = 0;
6910
6911 while (*e) {
6912 var = e;
6913 while (*e && *e != '\t') e++;
6914 varend = e;
6915 if (*e == '\t') e++;
6916 val = e;
6917 while (*e) e++;
6918 e++;
6919
ff3187f6 6920 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6921 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6922 ssh2_pkt_addstring(s->pktout, "env");
6923 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6924 ssh2_pkt_addstring_start(s->pktout);
6925 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6926 ssh2_pkt_addstring(s->pktout, val);
6927 ssh2_pkt_send(ssh, s->pktout);
73feed4f 6928
6929 s->num_env++;
6930 }
6931
6932 logeventf(ssh, "Sent %d environment variables", s->num_env);
6933
6934 s->env_ok = 0;
6935 s->env_left = s->num_env;
6936
6937 while (s->env_left > 0) {
b09eaa88 6938 crWaitUntilV(pktin);
73feed4f 6939
ff3187f6 6940 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6941 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 6942 bombout(("Unexpected response to environment request:"
ff3187f6 6943 " packet type %d", pktin->type));
73feed4f 6944 crStopV;
6945 }
6946 } else {
6947 s->env_ok++;
6948 }
6949
6950 s->env_left--;
6951 }
6952
6953 if (s->env_ok == s->num_env) {
6954 logevent("All environment variables successfully set");
6955 } else if (s->env_ok == 0) {
6956 logevent("All environment variables refused");
6957 c_write_str(ssh, "Server refused to set environment variables\r\n");
6958 } else {
6959 logeventf(ssh, "%d environment variables refused",
6960 s->num_env - s->env_ok);
6961 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6962 }
6963 }
6964
6965 /*
fd5e5847 6966 * Start a shell or a remote command. We may have to attempt
6967 * this twice if the config data has provided a second choice
6968 * of command.
7cca0d81 6969 */
0ed48730 6970 if (ssh->mainchan) while (1) {
fd5e5847 6971 int subsys;
6972 char *cmd;
6973
51470298 6974 if (ssh->fallback_cmd) {
86916870 6975 subsys = ssh->cfg.ssh_subsys2;
6976 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 6977 } else {
86916870 6978 subsys = ssh->cfg.ssh_subsys;
6979 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 6980 }
6981
ff3187f6 6982 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6983 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 6984 if (subsys) {
ff3187f6 6985 ssh2_pkt_addstring(s->pktout, "subsystem");
6986 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6987 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6988 } else if (*cmd) {
ff3187f6 6989 ssh2_pkt_addstring(s->pktout, "exec");
6990 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6991 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6992 } else {
ff3187f6 6993 ssh2_pkt_addstring(s->pktout, "shell");
6994 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 6995 }
ff3187f6 6996 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 6997
6998 crWaitUntilV(pktin);
6999
ff3187f6 7000 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7001 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7002 bombout(("Unexpected response to shell/command request:"
ff3187f6 7003 " packet type %d", pktin->type));
7ffdbc1a 7004 crStopV;
fd5e5847 7005 }
7006 /*
7007 * We failed to start the command. If this is the
7008 * fallback command, we really are finished; if it's
7009 * not, and if the fallback command exists, try falling
7010 * back to it before complaining.
7011 */
86916870 7012 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7013 logevent("Primary command failed; attempting fallback");
51470298 7014 ssh->fallback_cmd = TRUE;
fd5e5847 7015 continue;
7016 }
6b5cf8b4 7017 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7018 crStopV;
fd5e5847 7019 } else {
7020 logevent("Started a shell/command");
32874aea 7021 }
fd5e5847 7022 break;
7cca0d81 7023 }
7024
51470298 7025 ssh->state = SSH_STATE_SESSION;
7026 if (ssh->size_needed)
7027 ssh_size(ssh, ssh->term_width, ssh->term_height);
7028 if (ssh->eof_needed)
7029 ssh_special(ssh, TS_EOF);
6e48c3fe 7030
7cca0d81 7031 /*
7032 * Transfer data!
7033 */
b9d7bcad 7034 if (ssh->ldisc)
7035 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7036 if (ssh->mainchan)
7037 ssh->send_ok = 1;
7cca0d81 7038 while (1) {
e5574168 7039 crReturnV;
51470298 7040 s->try_send = FALSE;
ff3187f6 7041 if (pktin) {
2b7540a7 7042
51df0ab5 7043 /*
7044 * _All_ the connection-layer packets we expect to
7045 * receive are now handled by the dispatch table.
7046 * Anything that reaches here must be bogus.
7047 */
32874aea 7048
51df0ab5 7049 bombout(("Strange packet received: type %d", pktin->type));
7050 crStopV;
0ed48730 7051 } else if (ssh->mainchan) {
32874aea 7052 /*
7053 * We have spare data. Add it to the channel buffer.
7054 */
d8baa528 7055 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7056 s->try_send = TRUE;
32874aea 7057 }
51470298 7058 if (s->try_send) {
32874aea 7059 int i;
7060 struct ssh_channel *c;
7061 /*
7062 * Try to send data on all channels if we can.
7063 */
51470298 7064 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 7065 int bufsize;
7066 if (c->closes)
7067 continue; /* don't send on closing channels */
7068 bufsize = ssh2_try_send(c);
5471d09a 7069 if (bufsize == 0) {
7070 switch (c->type) {
7071 case CHAN_MAINSESSION:
7072 /* stdin need not receive an unthrottle
7073 * notification since it will be polled */
7074 break;
7075 case CHAN_X11:
7076 x11_unthrottle(c->u.x11.s);
7077 break;
7078 case CHAN_AGENT:
7079 /* agent sockets are request/response and need no
7080 * buffer management */
7081 break;
7082 case CHAN_SOCKDATA:
7083 pfd_unthrottle(c->u.pfd.s);
7084 break;
7085 }
7086 }
7087 }
7cca0d81 7088 }
e5574168 7089 }
7090
7091 crFinishV;
7092}
7093
7094/*
b09eaa88 7095 * Handlers for SSH2 messages that might arrive at any moment.
7096 */
7097void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7098{
7099 /* log reason code in disconnect message */
7100 char *buf, *msg;
7101 int nowlen, reason, msglen;
7102
7103 reason = ssh_pkt_getuint32(pktin);
7104 ssh_pkt_getstring(pktin, &msg, &msglen);
7105
7106 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7107 buf = dupprintf("Received disconnect message (%s)",
7108 ssh2_disconnect_reasons[reason]);
7109 } else {
7110 buf = dupprintf("Received disconnect message (unknown"
7111 " type %d)", reason);
7112 }
7113 logevent(buf);
7114 sfree(buf);
7115 buf = dupprintf("Disconnection message text: %n%.*s",
7116 &nowlen, msglen, msg);
7117 logevent(buf);
7118 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7119 reason,
7120 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7121 ssh2_disconnect_reasons[reason] : "unknown",
7122 buf+nowlen));
7123 sfree(buf);
7124}
7125
7126void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7127{
7128 /* log the debug message */
7129 char *buf, *msg;
7130 int msglen;
7131 int always_display;
7132
7133 /* XXX maybe we should actually take notice of this */
7134 always_display = ssh2_pkt_getbool(pktin);
7135 ssh_pkt_getstring(pktin, &msg, &msglen);
7136
7137 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7138 logevent(buf);
7139 sfree(buf);
7140}
7141
7142void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7143{
7144 struct Packet *pktout;
7145 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7146 ssh2_pkt_adduint32(pktout, pktin->sequence);
7147 /*
7148 * UNIMPLEMENTED messages MUST appear in the same order as the
7149 * messages they respond to. Hence, never queue them.
7150 */
7151 ssh2_pkt_send_noqueue(ssh, pktout);
7152}
7153
7154/*
7cca0d81 7155 * Handle the top-level SSH2 protocol.
7156 */
b09eaa88 7157static void ssh2_protocol_setup(Ssh ssh)
7158{
7159 int i;
7160
7161 /*
7162 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7163 */
7164 for (i = 0; i < 256; i++)
7165 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7166
7167 /*
7168 * Any message we actually understand, we set to NULL so that
7169 * the coroutines will get it.
7170 */
7171 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7172 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7173 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7174 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7175 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7176 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7177 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7178 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7179 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7180 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7181 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7182 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7183 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7184 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7185 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7186 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7187 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7188 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7189 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7190 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7191 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7192 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7193 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7194 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7195 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7196 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7197 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7198 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7199 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7200 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7201 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7202 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7203 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7204
7205 /*
7206 * These special message types we install handlers for.
7207 */
7208 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7209 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7210 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7211}
7212
9442dd57 7213static void ssh2_timer(void *ctx, long now)
7214{
7215 Ssh ssh = (Ssh)ctx;
7216
e6c1536e 7217 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 7218 now - ssh->next_rekey >= 0) {
7219 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7220 -1, NULL);
7221 }
7222}
7223
ff3187f6 7224static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7225 struct Packet *pktin)
7cca0d81 7226{
b09eaa88 7227 if (ssh->state == SSH_STATE_CLOSED)
7228 return;
7229
9442dd57 7230 if (pktin) {
7231 ssh->incoming_data_size += pktin->encrypted_len;
7232 if (!ssh->kex_in_progress &&
d57f70af 7233 ssh->max_data_size != 0 &&
7234 ssh->incoming_data_size > ssh->max_data_size)
9442dd57 7235 do_ssh2_transport(ssh, "Initiating key re-exchange "
7236 "(too much data received)", -1, NULL);
7237 }
7238
b09eaa88 7239 if (pktin && ssh->packet_dispatch[pktin->type]) {
7240 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7241 return;
b09eaa88 7242 }
7243
7244 if (!ssh->protocol_initial_phase_done ||
7245 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7246 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7247 !ssh->protocol_initial_phase_done) {
7248 ssh->protocol_initial_phase_done = TRUE;
7249 /*
7250 * Allow authconn to initialise itself.
7251 */
7252 do_ssh2_authconn(ssh, NULL, 0, NULL);
7253 }
7254 } else {
7255 do_ssh2_authconn(ssh, in, inlen, pktin);
7256 }
7cca0d81 7257}
7258
7259/*
8df7a775 7260 * Called to set up the connection.
374330e2 7261 *
7262 * Returns an error message, or NULL on success.
374330e2 7263 */
cbe2d68f 7264static const char *ssh_init(void *frontend_handle, void **backend_handle,
7265 Config *cfg,
79bf227b 7266 char *host, int port, char **realhost, int nodelay,
7267 int keepalive)
32874aea 7268{
cbe2d68f 7269 const char *p;
51470298 7270 Ssh ssh;
7271
3d88e64d 7272 ssh = snew(struct ssh_tag);
86916870 7273 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7274 ssh->version = 0; /* when not ready yet */
51470298 7275 ssh->s = NULL;
7276 ssh->cipher = NULL;
371e569c 7277 ssh->v1_cipher_ctx = NULL;
0183b242 7278 ssh->crcda_ctx = NULL;
51470298 7279 ssh->cscipher = NULL;
371e569c 7280 ssh->cs_cipher_ctx = NULL;
51470298 7281 ssh->sccipher = NULL;
371e569c 7282 ssh->sc_cipher_ctx = NULL;
51470298 7283 ssh->csmac = NULL;
a8327734 7284 ssh->cs_mac_ctx = NULL;
51470298 7285 ssh->scmac = NULL;
e0e1a00d 7286 ssh->sc_mac_ctx = NULL;
51470298 7287 ssh->cscomp = NULL;
5366aed8 7288 ssh->cs_comp_ctx = NULL;
51470298 7289 ssh->sccomp = NULL;
5366aed8 7290 ssh->sc_comp_ctx = NULL;
51470298 7291 ssh->kex = NULL;
389aa499 7292 ssh->kex_ctx = NULL;
51470298 7293 ssh->hostkey = NULL;
7294 ssh->exitcode = -1;
7295 ssh->state = SSH_STATE_PREPACKET;
7296 ssh->size_needed = FALSE;
7297 ssh->eof_needed = FALSE;
b9d7bcad 7298 ssh->ldisc = NULL;
a8327734 7299 ssh->logctx = NULL;
51470298 7300 ssh->deferred_send_data = NULL;
7301 ssh->deferred_len = 0;
7302 ssh->deferred_size = 0;
7303 ssh->fallback_cmd = 0;
7304 ssh->pkt_ctx = 0;
302121de 7305 ssh->x11auth = NULL;
be738459 7306 ssh->v1_compressing = FALSE;
51470298 7307 ssh->v2_outgoing_sequence = 0;
7308 ssh->ssh1_rdpkt_crstate = 0;
7309 ssh->ssh2_rdpkt_crstate = 0;
7310 ssh->do_ssh_init_crstate = 0;
7311 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7312 ssh->do_ssh1_connection_crstate = 0;
51470298 7313 ssh->do_ssh1_login_crstate = 0;
7314 ssh->do_ssh2_transport_crstate = 0;
7315 ssh->do_ssh2_authconn_crstate = 0;
7316 ssh->do_ssh_init_state = NULL;
7317 ssh->do_ssh1_login_state = NULL;
7318 ssh->do_ssh2_transport_state = NULL;
7319 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7320 ssh->mainchan = NULL;
968d2d92 7321 ssh->throttled_all = 0;
7322 ssh->v1_stdout_throttling = 0;
590f6a5f 7323 ssh->queue = NULL;
7324 ssh->queuelen = ssh->queuesize = 0;
7325 ssh->queueing = FALSE;
06fadff5 7326 ssh->qhead = ssh->qtail = NULL;
51470298 7327
7328 *backend_handle = ssh;
32874aea 7329
8f203108 7330#ifdef MSCRYPTOAPI
32874aea 7331 if (crypto_startup() == 0)
8f203108 7332 return "Microsoft high encryption pack not installed!";
7333#endif
374330e2 7334
51470298 7335 ssh->frontend = frontend_handle;
86916870 7336 ssh->term_width = ssh->cfg.width;
7337 ssh->term_height = ssh->cfg.height;
887035a5 7338
fabd1805 7339 ssh->channels = NULL;
7340 ssh->rportfwds = NULL;
f47a5ffb 7341 ssh->portfwds = NULL;
fabd1805 7342
51470298 7343 ssh->send_ok = 0;
7344 ssh->editing = 0;
7345 ssh->echoing = 0;
7346 ssh->v1_throttle_count = 0;
7347 ssh->overall_bufsize = 0;
7348 ssh->fallback_cmd = 0;
8df7a775 7349
3648d4c5 7350 ssh->protocol = NULL;
7351
b09eaa88 7352 ssh->protocol_initial_phase_done = FALSE;
7353
39934deb 7354 ssh->pinger = NULL;
7355
9442dd57 7356 ssh->incoming_data_size = ssh->outgoing_data_size =
7357 ssh->deferred_data_size = 0L;
d57f70af 7358 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 7359 ssh->kex_in_progress = FALSE;
7360
79bf227b 7361 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7362 if (p != NULL)
7363 return p;
374330e2 7364
5d17ccfc 7365 random_ref();
7366
374330e2 7367 return NULL;
7368}
7369
fabd1805 7370static void ssh_free(void *handle)
7371{
7372 Ssh ssh = (Ssh) handle;
7373 struct ssh_channel *c;
7374 struct ssh_rportfwd *pf;
7375
7376 if (ssh->v1_cipher_ctx)
7377 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7378 if (ssh->cs_cipher_ctx)
7379 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7380 if (ssh->sc_cipher_ctx)
7381 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7382 if (ssh->cs_mac_ctx)
7383 ssh->csmac->free_context(ssh->cs_mac_ctx);
7384 if (ssh->sc_mac_ctx)
7385 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7386 if (ssh->cs_comp_ctx) {
7387 if (ssh->cscomp)
7388 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7389 else
7390 zlib_compress_cleanup(ssh->cs_comp_ctx);
7391 }
7392 if (ssh->sc_comp_ctx) {
7393 if (ssh->sccomp)
7394 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7395 else
7396 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7397 }
fabd1805 7398 if (ssh->kex_ctx)
7399 dh_cleanup(ssh->kex_ctx);
7400 sfree(ssh->savedhost);
7401
590f6a5f 7402 while (ssh->queuelen-- > 0)
7403 ssh_free_packet(ssh->queue[ssh->queuelen]);
7404 sfree(ssh->queue);
7405
06fadff5 7406 while (ssh->qhead) {
7407 struct queued_handler *qh = ssh->qhead;
7408 ssh->qhead = qh->next;
7409 sfree(ssh->qhead);
7410 }
7411 ssh->qhead = ssh->qtail = NULL;
7412
fabd1805 7413 if (ssh->channels) {
7414 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7415 switch (c->type) {
7416 case CHAN_X11:
7417 if (c->u.x11.s != NULL)
7418 x11_close(c->u.x11.s);
7419 break;
7420 case CHAN_SOCKDATA:
7421 if (c->u.pfd.s != NULL)
7422 pfd_close(c->u.pfd.s);
7423 break;
7424 }
7425 sfree(c);
7426 }
7427 freetree234(ssh->channels);
cdb52705 7428 ssh->channels = NULL;
fabd1805 7429 }
7430
7431 if (ssh->rportfwds) {
7432 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7433 sfree(pf);
7434 freetree234(ssh->rportfwds);
cdb52705 7435 ssh->rportfwds = NULL;
fabd1805 7436 }
7437 sfree(ssh->deferred_send_data);
7438 if (ssh->x11auth)
7439 x11_free_auth(ssh->x11auth);
7440 sfree(ssh->do_ssh_init_state);
7441 sfree(ssh->do_ssh1_login_state);
7442 sfree(ssh->do_ssh2_transport_state);
7443 sfree(ssh->do_ssh2_authconn_state);
679539d7 7444 if (ssh->crcda_ctx) {
7445 crcda_free_context(ssh->crcda_ctx);
7446 ssh->crcda_ctx = NULL;
7447 }
fabd1805 7448 if (ssh->s)
36f94d1f 7449 ssh_do_close(ssh);
9442dd57 7450 expire_timer_context(ssh);
39934deb 7451 if (ssh->pinger)
7452 pinger_free(ssh->pinger);
ee50e8b6 7453 sfree(ssh);
5d17ccfc 7454
7455 random_unref();
fabd1805 7456}
7457
374330e2 7458/*
86916870 7459 * Reconfigure the SSH backend.
86916870 7460 */
7461static void ssh_reconfig(void *handle, Config *cfg)
7462{
7463 Ssh ssh = (Ssh) handle;
e6c1536e 7464 char *rekeying = NULL;
7465 unsigned long old_max_data_size;
7466
39934deb 7467 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
fda2feb1 7468 ssh_setup_portfwd(ssh, cfg);
e6c1536e 7469
7470 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7471 cfg->ssh_rekey_time != 0) {
7472 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7473 long now = GETTICKCOUNT();
7474
7475 if (new_next - now < 0) {
7476 rekeying = "Initiating key re-exchange (timeout shortened)";
7477 } else {
7478 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7479 }
7480 }
7481
7482 old_max_data_size = ssh->max_data_size;
7483 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7484 if (old_max_data_size != ssh->max_data_size &&
7485 ssh->max_data_size != 0) {
7486 if (ssh->outgoing_data_size > ssh->max_data_size ||
7487 ssh->incoming_data_size > ssh->max_data_size)
7488 rekeying = "Initiating key re-exchange (data limit lowered)";
7489 }
7490
7491 if (rekeying && !ssh->kex_in_progress) {
7492 do_ssh2_transport(ssh, rekeying, -1, NULL);
7493 }
7494
86916870 7495 ssh->cfg = *cfg; /* STRUCTURE COPY */
7496}
7497
7498/*
374330e2 7499 * Called to send data down the Telnet connection.
7500 */
51470298 7501static int ssh_send(void *handle, char *buf, int len)
32874aea 7502{
51470298 7503 Ssh ssh = (Ssh) handle;
7504
7505 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7506 return 0;
374330e2 7507
d8baa528 7508 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7509
51470298 7510 return ssh_sendbuffer(ssh);
5471d09a 7511}
7512
7513/*
7514 * Called to query the current amount of buffered stdin data.
7515 */
51470298 7516static int ssh_sendbuffer(void *handle)
5471d09a 7517{
51470298 7518 Ssh ssh = (Ssh) handle;
5471d09a 7519 int override_value;
7520
51470298 7521 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7522 return 0;
7523
7524 /*
7525 * If the SSH socket itself has backed up, add the total backup
7526 * size on that to any individual buffer on the stdin channel.
7527 */
7528 override_value = 0;
51470298 7529 if (ssh->throttled_all)
7530 override_value = ssh->overall_bufsize;
5471d09a 7531
51470298 7532 if (ssh->version == 1) {
5471d09a 7533 return override_value;
51470298 7534 } else if (ssh->version == 2) {
7535 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7536 return override_value;
7537 else
51470298 7538 return (override_value +
7539 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7540 }
7541
7542 return 0;
374330e2 7543}
7544
7545/*
6e48c3fe 7546 * Called to set the size of the window from SSH's POV.
374330e2 7547 */
51470298 7548static void ssh_size(void *handle, int width, int height)
32874aea 7549{
51470298 7550 Ssh ssh = (Ssh) handle;
ff3187f6 7551 struct Packet *pktout;
51470298 7552
7553 ssh->term_width = width;
7554 ssh->term_height = height;
f278d6f8 7555
51470298 7556 switch (ssh->state) {
374330e2 7557 case SSH_STATE_BEFORE_SIZE:
3687d221 7558 case SSH_STATE_PREPACKET:
21248260 7559 case SSH_STATE_CLOSED:
374330e2 7560 break; /* do nothing */
7561 case SSH_STATE_INTERMED:
51470298 7562 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7563 break;
7564 case SSH_STATE_SESSION:
86916870 7565 if (!ssh->cfg.nopty) {
51470298 7566 if (ssh->version == 1) {
7567 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7568 PKT_INT, ssh->term_height,
7569 PKT_INT, ssh->term_width,
32874aea 7570 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7571 } else if (ssh->mainchan) {
ff3187f6 7572 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7573 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7574 ssh2_pkt_addstring(pktout, "window-change");
7575 ssh2_pkt_addbool(pktout, 0);
7576 ssh2_pkt_adduint32(pktout, ssh->term_width);
7577 ssh2_pkt_adduint32(pktout, ssh->term_height);
7578 ssh2_pkt_adduint32(pktout, 0);
7579 ssh2_pkt_adduint32(pktout, 0);
7580 ssh2_pkt_send(ssh, pktout);
32874aea 7581 }
7582 }
7583 break;
374330e2 7584 }
7585}
7586
7587/*
125105d1 7588 * Return a list of the special codes that make sense in this
7589 * protocol.
7590 */
7591static const struct telnet_special *ssh_get_specials(void *handle)
7592{
786ba75e 7593 static const struct telnet_special ssh1_ignore_special[] = {
7594 {"IGNORE message", TS_NOP}
7595 };
7596 static const struct telnet_special ssh2_transport_specials[] = {
62638676 7597 {"IGNORE message", TS_NOP},
9442dd57 7598 {"Repeat key exchange", TS_REKEY},
62638676 7599 };
7600 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7601 {NULL, TS_SEP},
7602 {"Break", TS_BRK},
786ba75e 7603 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 7604 * They include all the ISO C signals, but are a subset of the POSIX
7605 * required signals. */
7606 {"SIGINT (Interrupt)", TS_SIGINT},
7607 {"SIGTERM (Terminate)", TS_SIGTERM},
7608 {"SIGKILL (Kill)", TS_SIGKILL},
7609 {"SIGQUIT (Quit)", TS_SIGQUIT},
7610 {"SIGHUP (Hangup)", TS_SIGHUP},
7611 {"More signals", TS_SUBMENU},
7612 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7613 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7614 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7615 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7616 {NULL, TS_EXITMENU}
62638676 7617 };
7618 static const struct telnet_special specials_end[] = {
6f2d0cde 7619 {NULL, TS_EXITMENU}
62638676 7620 };
786ba75e 7621 /* XXX review this length for any changes: */
7622 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 7623 lenof(ssh2_session_specials) +
7624 lenof(specials_end)];
125105d1 7625 Ssh ssh = (Ssh) handle;
62638676 7626 int i = 0;
7627#define ADD_SPECIALS(name) \
7628 do { \
7629 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7630 memcpy(&ssh_specials[i], name, sizeof name); \
7631 i += lenof(name); \
7632 } while(0)
125105d1 7633
7634 if (ssh->version == 1) {
62638676 7635 /* Don't bother offering IGNORE if we've decided the remote
7636 * won't cope with it, since we wouldn't bother sending it if
7637 * asked anyway. */
7638 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 7639 ADD_SPECIALS(ssh1_ignore_special);
125105d1 7640 } else if (ssh->version == 2) {
786ba75e 7641 ADD_SPECIALS(ssh2_transport_specials);
62638676 7642 if (ssh->mainchan)
7643 ADD_SPECIALS(ssh2_session_specials);
7644 } /* else we're not ready yet */
7645
7646 if (i) {
7647 ADD_SPECIALS(specials_end);
7648 return ssh_specials;
7649 } else {
125105d1 7650 return NULL;
62638676 7651 }
7652#undef ADD_SPECIALS
125105d1 7653}
7654
7655/*
6abbf9e3 7656 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7657 * can send an EOF and collect resulting output (e.g. `plink
7658 * hostname sort').
374330e2 7659 */
51470298 7660static void ssh_special(void *handle, Telnet_Special code)
32874aea 7661{
51470298 7662 Ssh ssh = (Ssh) handle;
ff3187f6 7663 struct Packet *pktout;
51470298 7664
6abbf9e3 7665 if (code == TS_EOF) {
51470298 7666 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7667 /*
7668 * Buffer the EOF in case we are pre-SESSION, so we can
7669 * send it as soon as we reach SESSION.
7670 */
7671 if (code == TS_EOF)
51470298 7672 ssh->eof_needed = TRUE;
32874aea 7673 return;
7674 }
51470298 7675 if (ssh->version == 1) {
7676 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7677 } else if (ssh->mainchan) {
ff3187f6 7678 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7679 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7680 ssh2_pkt_send(ssh, pktout);
32874aea 7681 }
7682 logevent("Sent EOF message");
125105d1 7683 } else if (code == TS_PING || code == TS_NOP) {
51470298 7684 if (ssh->state == SSH_STATE_CLOSED
7685 || ssh->state == SSH_STATE_PREPACKET) return;
7686 if (ssh->version == 1) {
7687 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7688 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7689 } else {
ff3187f6 7690 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7691 ssh2_pkt_addstring_start(pktout);
590f6a5f 7692 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7693 }
9442dd57 7694 } else if (code == TS_REKEY) {
7695 if (!ssh->kex_in_progress && ssh->version == 2) {
7696 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7697 " user request", -1, NULL);
7698 }
125105d1 7699 } else if (code == TS_BRK) {
7700 if (ssh->state == SSH_STATE_CLOSED
7701 || ssh->state == SSH_STATE_PREPACKET) return;
7702 if (ssh->version == 1) {
7703 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7704 } else if (ssh->mainchan) {
ff3187f6 7705 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7706 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7707 ssh2_pkt_addstring(pktout, "break");
7708 ssh2_pkt_addbool(pktout, 0);
7709 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7710 ssh2_pkt_send(ssh, pktout);
125105d1 7711 }
6abbf9e3 7712 } else {
6f2d0cde 7713 /* Is is a POSIX signal? */
7714 char *signame = NULL;
7715 if (code == TS_SIGABRT) signame = "ABRT";
7716 if (code == TS_SIGALRM) signame = "ALRM";
7717 if (code == TS_SIGFPE) signame = "FPE";
7718 if (code == TS_SIGHUP) signame = "HUP";
7719 if (code == TS_SIGILL) signame = "ILL";
7720 if (code == TS_SIGINT) signame = "INT";
7721 if (code == TS_SIGKILL) signame = "KILL";
7722 if (code == TS_SIGPIPE) signame = "PIPE";
7723 if (code == TS_SIGQUIT) signame = "QUIT";
7724 if (code == TS_SIGSEGV) signame = "SEGV";
7725 if (code == TS_SIGTERM) signame = "TERM";
7726 if (code == TS_SIGUSR1) signame = "USR1";
7727 if (code == TS_SIGUSR2) signame = "USR2";
7728 /* The SSH-2 protocol does in principle support arbitrary named
7729 * signals, including signame@domain, but we don't support those. */
7730 if (signame) {
7731 /* It's a signal. */
7732 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7733 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7734 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7735 ssh2_pkt_addstring(pktout, "signal");
7736 ssh2_pkt_addbool(pktout, 0);
7737 ssh2_pkt_addstring(pktout, signame);
7738 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7739 logeventf(ssh, "Sent signal SIG%s", signame);
7740 }
7741 } else {
7742 /* Never heard of it. Do nothing */
7743 }
6abbf9e3 7744 }
374330e2 7745}
7746
51470298 7747void *new_sock_channel(void *handle, Socket s)
d74d141c 7748{
51470298 7749 Ssh ssh = (Ssh) handle;
d74d141c 7750 struct ssh_channel *c;
3d88e64d 7751 c = snew(struct ssh_channel);
51470298 7752 c->ssh = ssh;
d74d141c 7753
7754 if (c) {
bc240b21 7755 c->remoteid = -1; /* to be set when open confirmed */
51470298 7756 c->localid = alloc_channel_id(ssh);
d74d141c 7757 c->closes = 0;
bc240b21 7758 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7759 c->u.pfd.s = s;
013dd8c0 7760 bufchain_init(&c->v.v2.outbuffer);
51470298 7761 add234(ssh->channels, c);
d74d141c 7762 }
7763 return c;
7764}
7765
5471d09a 7766/*
7767 * This is called when stdout/stderr (the entity to which
7768 * from_backend sends data) manages to clear some backlog.
7769 */
ae9ae89f 7770static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7771{
51470298 7772 Ssh ssh = (Ssh) handle;
7773 if (ssh->version == 1) {
7774 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7775 ssh->v1_stdout_throttling = 0;
7776 ssh1_throttle(ssh, -1);
5471d09a 7777 }
7778 } else {
51470298 7779 if (ssh->mainchan && ssh->mainchan->closes == 0)
7780 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7781 }
7782}
7783
6b78788a 7784void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7785{
7786 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7787 Ssh ssh = c->ssh;
ff3187f6 7788 struct Packet *pktout;
d74d141c 7789
57356d63 7790 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7791
51470298 7792 if (ssh->version == 1) {
7793 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7794 PKT_INT, c->localid,
7795 PKT_STR, hostname,
7796 PKT_INT, port,
7797 //PKT_STR, <org:orgport>,
7798 PKT_END);
7799 } else {
ff3187f6 7800 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7801 ssh2_pkt_addstring(pktout, "direct-tcpip");
7802 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7803 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7804 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7805 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7806 ssh2_pkt_addstring(pktout, hostname);
7807 ssh2_pkt_adduint32(pktout, port);
bc240b21 7808 /*
7809 * We make up values for the originator data; partly it's
7810 * too much hassle to keep track, and partly I'm not
7811 * convinced the server should be told details like that
7812 * about my local network configuration.
7813 */
ff3187f6 7814 ssh2_pkt_addstring(pktout, "client-side-connection");
7815 ssh2_pkt_adduint32(pktout, 0);
7816 ssh2_pkt_send(ssh, pktout);
bc240b21 7817 }
d74d141c 7818}
7819
51470298 7820static Socket ssh_socket(void *handle)
32874aea 7821{
51470298 7822 Ssh ssh = (Ssh) handle;
7823 return ssh->s;
32874aea 7824}
8ccc75b0 7825
51470298 7826static int ssh_sendok(void *handle)
32874aea 7827{
51470298 7828 Ssh ssh = (Ssh) handle;
7829 return ssh->send_ok;
32874aea 7830}
fb09bf1c 7831
51470298 7832static int ssh_ldisc(void *handle, int option)
32874aea 7833{
51470298 7834 Ssh ssh = (Ssh) handle;
32874aea 7835 if (option == LD_ECHO)
51470298 7836 return ssh->echoing;
32874aea 7837 if (option == LD_EDIT)
51470298 7838 return ssh->editing;
0965bee0 7839 return FALSE;
7840}
7841
b9d7bcad 7842static void ssh_provide_ldisc(void *handle, void *ldisc)
7843{
7844 Ssh ssh = (Ssh) handle;
7845 ssh->ldisc = ldisc;
7846}
7847
a8327734 7848static void ssh_provide_logctx(void *handle, void *logctx)
7849{
7850 Ssh ssh = (Ssh) handle;
7851 ssh->logctx = logctx;
7852}
7853
51470298 7854static int ssh_return_exitcode(void *handle)
7855{
7856 Ssh ssh = (Ssh) handle;
3bb2f322 7857 if (ssh->s != NULL)
7858 return -1;
7859 else
7860 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7861}
7862
7863/*
f89c3294 7864 * cfg_info for SSH is the currently running version of the
7865 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
7866 */
7867static int ssh_cfg_info(void *handle)
7868{
7869 Ssh ssh = (Ssh) handle;
7870 return ssh->version;
7871}
7872
7873/*
51470298 7874 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7875 * that fails. This variable is the means by which scp.c can reach
7876 * into the SSH code and find out which one it got.
7877 */
7878extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7879{
51470298 7880 Ssh ssh = (Ssh) handle;
7881 return ssh->fallback_cmd;
d8d6c7e5 7882}
7883
374330e2 7884Backend ssh_backend = {
7885 ssh_init,
fabd1805 7886 ssh_free,
86916870 7887 ssh_reconfig,
374330e2 7888 ssh_send,
5471d09a 7889 ssh_sendbuffer,
374330e2 7890 ssh_size,
4017be6d 7891 ssh_special,
125105d1 7892 ssh_get_specials,
8ccc75b0 7893 ssh_socket,
d8d6c7e5 7894 ssh_return_exitcode,
97db3be4 7895 ssh_sendok,
0965bee0 7896 ssh_ldisc,
b9d7bcad 7897 ssh_provide_ldisc,
a8327734 7898 ssh_provide_logctx,
5471d09a 7899 ssh_unthrottle,
f89c3294 7900 ssh_cfg_info,
97db3be4 7901 22
bc240b21 7902};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator