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