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[u/mdw/putty] / ssh.c
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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 */
107#define SSH2_PKTCTX_DHGROUP1 0x0001
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
8e975795 165#define BUG_SSH2_DH_GEX 64
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);
225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
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;
319
51470298 320static void ssh2_pkt_init(Ssh, int pkt_type);
321static void ssh2_pkt_addbool(Ssh, unsigned char value);
322static void ssh2_pkt_adduint32(Ssh, unsigned long value);
323static void ssh2_pkt_addstring_start(Ssh);
324static void ssh2_pkt_addstring_str(Ssh, char *data);
325static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
326static void ssh2_pkt_addstring(Ssh, char *data);
d8baa528 327static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
51470298 328static void ssh2_pkt_addmp(Ssh, Bignum b);
329static int ssh2_pkt_construct(Ssh);
330static void ssh2_pkt_send(Ssh);
839f10db 331static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt);
332static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt);
3d63ca2e 333
5471d09a 334/*
335 * Buffer management constants. There are several of these for
336 * various different purposes:
337 *
338 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
339 * on a local data stream before we throttle the whole SSH
340 * connection (in SSH1 only). Throttling the whole connection is
341 * pretty drastic so we set this high in the hope it won't
342 * happen very often.
343 *
344 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
345 * on the SSH connection itself before we defensively throttle
346 * _all_ local data streams. This is pretty drastic too (though
347 * thankfully unlikely in SSH2 since the window mechanism should
348 * ensure that the server never has any need to throttle its end
349 * of the connection), so we set this high as well.
350 *
351 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
352 * channels.
353 */
354
355#define SSH1_BUFFER_LIMIT 32768
356#define SSH_MAX_BACKLOG 32768
357#define OUR_V2_WINSIZE 16384
d74d141c 358
a92dd380 359const static struct ssh_kex *kex_algs[] = {
a92dd380 360 &ssh_diffiehellman_gex,
32874aea 361 &ssh_diffiehellman
362};
e5574168 363
85cc02bb 364const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 365
e0e1a00d 366static void *nullmac_make_context(void)
367{
368 return NULL;
369}
370static void nullmac_free_context(void *handle)
371{
372}
373static void nullmac_key(void *handle, unsigned char *key)
32874aea 374{
375}
e0e1a00d 376static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 377 unsigned long seq)
378{
379}
e0e1a00d 380static int nullmac_verify(void *handle, unsigned char *blk, int len,
381 unsigned long seq)
32874aea 382{
383 return 1;
384}
57476f6b 385const static struct ssh_mac ssh_mac_none = {
e0e1a00d 386 nullmac_make_context, nullmac_free_context, nullmac_key,
387 nullmac_generate, nullmac_verify, "none", 0
e5574168 388};
8b2715b2 389const static struct ssh_mac *macs[] = {
32874aea 390 &ssh_sha1, &ssh_md5, &ssh_mac_none
391};
8b2715b2 392const static struct ssh_mac *buggymacs[] = {
32874aea 393 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
394};
e5574168 395
5366aed8 396static void *ssh_comp_none_init(void)
397{
398 return NULL;
399}
400static void ssh_comp_none_cleanup(void *handle)
32874aea 401{
402}
5366aed8 403static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 404 unsigned char **outblock, int *outlen)
405{
406 return 0;
407}
5366aed8 408static int ssh_comp_none_disable(void *handle)
32874aea 409{
4ba9b64b 410 return 0;
411}
57476f6b 412const static struct ssh_compress ssh_comp_none = {
4ba9b64b 413 "none",
5366aed8 414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
416 ssh_comp_none_disable, NULL
e5574168 417};
4ba9b64b 418extern const struct ssh_compress ssh_zlib;
419const static struct ssh_compress *compressions[] = {
32874aea 420 &ssh_zlib, &ssh_comp_none
421};
374330e2 422
32874aea 423enum { /* channel types */
783415f8 424 CHAN_MAINSESSION,
425 CHAN_X11,
426 CHAN_AGENT,
bc240b21 427 CHAN_SOCKDATA,
428 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 429};
430
dacbd0e8 431/*
432 * 2-3-4 tree storing channels.
433 */
434struct ssh_channel {
51470298 435 Ssh ssh; /* pointer back to main context */
d211621f 436 unsigned remoteid, localid;
dacbd0e8 437 int type;
0357890f 438 /*
439 * In SSH1, this value contains four bits:
440 *
441 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
442 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
443 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
444 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
445 *
446 * A channel is completely finished with when all four bits are set.
447 */
dacbd0e8 448 int closes;
5471d09a 449 union {
450 struct ssh1_data_channel {
451 int throttling;
452 } v1;
453 struct ssh2_data_channel {
454 bufchain outbuffer;
455 unsigned remwindow, remmaxpkt;
456 unsigned locwindow;
457 } v2;
458 } v;
dacbd0e8 459 union {
32874aea 460 struct ssh_agent_channel {
461 unsigned char *message;
462 unsigned char msglen[4];
463 int lensofar, totallen;
464 } a;
465 struct ssh_x11_channel {
466 Socket s;
467 } x11;
d74d141c 468 struct ssh_pfd_channel {
469 Socket s;
470 } pfd;
dacbd0e8 471 } u;
472};
57476f6b 473
d74d141c 474/*
bc240b21 475 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
476 * 2 use this structure in different ways, reflecting SSH 2's
477 * altogether saner approach to port forwarding.
478 *
479 * In SSH 1, you arrange a remote forwarding by sending the server
480 * the remote port number, and the local destination host:port.
481 * When a connection comes in, the server sends you back that
482 * host:port pair, and you connect to it. This is a ready-made
483 * security hole if you're not on the ball: a malicious server
484 * could send you back _any_ host:port pair, so if you trustingly
485 * connect to the address it gives you then you've just opened the
486 * entire inside of your corporate network just by connecting
487 * through it to a dodgy SSH server. Hence, we must store a list of
488 * host:port pairs we _are_ trying to forward to, and reject a
489 * connection request from the server if it's not in the list.
490 *
491 * In SSH 2, each side of the connection minds its own business and
492 * doesn't send unnecessary information to the other. You arrange a
493 * remote forwarding by sending the server just the remote port
494 * number. When a connection comes in, the server tells you which
495 * of its ports was connected to; and _you_ have to remember what
496 * local host:port pair went with that port number.
497 *
498 * Hence: in SSH 1 this structure stores host:port pairs we intend
499 * to allow connections to, and is indexed by those host:port
500 * pairs. In SSH 2 it stores a mapping from source port to
501 * destination host:port pair, and is indexed by source port.
d74d141c 502 */
503struct ssh_rportfwd {
bc240b21 504 unsigned sport, dport;
505 char dhost[256];
d74d141c 506};
507
57476f6b 508struct Packet {
509 long length;
510 int type;
511 unsigned char *data;
512 unsigned char *body;
513 long savedpos;
514 long maxlen;
515};
516
51470298 517static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
518static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
519static void ssh_size(void *handle, int width, int height);
520static void ssh_special(void *handle, Telnet_Special);
5471d09a 521static int ssh2_try_send(struct ssh_channel *c);
51470298 522static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
523static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 524static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 525static int ssh_sendbuffer(void *handle);
36f94d1f 526static void ssh_do_close(Ssh ssh);
57476f6b 527
51470298 528struct rdpkt1_state_tag {
57476f6b 529 long len, pad, biglen, to_read;
530 unsigned long realcrc, gotcrc;
531 unsigned char *p;
532 int i;
533 int chunk;
51470298 534};
57476f6b 535
51470298 536struct rdpkt2_state_tag {
960e736a 537 long len, pad, payload, packetlen, maclen;
538 int i;
539 int cipherblk;
540 unsigned long incoming_sequence;
51470298 541};
542
543struct ssh_tag {
544 const struct plug_function_table *fn;
545 /* the above field _must_ be first in the structure */
546
547 SHA_State exhash, exhashbase;
548
549 Socket s;
550
b9d7bcad 551 void *ldisc;
a8327734 552 void *logctx;
b9d7bcad 553
51470298 554 unsigned char session_key[32];
555 int v1_compressing;
556 int v1_remote_protoflags;
557 int v1_local_protoflags;
558 int agentfwd_enabled;
559 int X11_fwd_enabled;
560 int remote_bugs;
561 const struct ssh_cipher *cipher;
371e569c 562 void *v1_cipher_ctx;
0183b242 563 void *crcda_ctx;
51470298 564 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 565 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 566 const struct ssh_mac *csmac, *scmac;
e0e1a00d 567 void *cs_mac_ctx, *sc_mac_ctx;
51470298 568 const struct ssh_compress *cscomp, *sccomp;
5366aed8 569 void *cs_comp_ctx, *sc_comp_ctx;
51470298 570 const struct ssh_kex *kex;
571 const struct ssh_signkey *hostkey;
572 unsigned char v2_session_id[20];
27cd7fc2 573 void *kex_ctx;
51470298 574
575 char *savedhost;
576 int savedport;
577 int send_ok;
578 int echoing, editing;
579
580 void *frontend;
581
db219738 582 int ospeed, ispeed; /* temporaries */
51470298 583 int term_width, term_height;
584
585 tree234 *channels; /* indexed by local id */
586 struct ssh_channel *mainchan; /* primary session channel */
587 int exitcode;
588
589 tree234 *rportfwds;
590
591 enum {
592 SSH_STATE_PREPACKET,
593 SSH_STATE_BEFORE_SIZE,
594 SSH_STATE_INTERMED,
595 SSH_STATE_SESSION,
596 SSH_STATE_CLOSED
597 } state;
598
599 int size_needed, eof_needed;
600
601 struct Packet pktin;
602 struct Packet pktout;
603 unsigned char *deferred_send_data;
604 int deferred_len, deferred_size;
605
606 /*
9a10ecf4 607 * State associated with packet logging
608 */
609 int pktout_logmode;
610 int pktout_nblanks;
611 struct logblank_t *pktout_blanks;
612
613 /*
51470298 614 * Gross hack: pscp will try to start SFTP but fall back to
615 * scp1 if that fails. This variable is the means by which
616 * scp.c can reach into the SSH code and find out which one it
617 * got.
618 */
619 int fallback_cmd;
620
621 /*
622 * Used for username and password input.
623 */
624 char *userpass_input_buffer;
625 int userpass_input_buflen;
626 int userpass_input_bufpos;
627 int userpass_input_echo;
628
629 char *portfwd_strptr;
630 int pkt_ctx;
631
302121de 632 void *x11auth;
633
51470298 634 int version;
635 int v1_throttle_count;
636 int overall_bufsize;
637 int throttled_all;
638 int v1_stdout_throttling;
639 int v2_outgoing_sequence;
640
641 int ssh1_rdpkt_crstate;
642 int ssh2_rdpkt_crstate;
643 int do_ssh_init_crstate;
644 int ssh_gotdata_crstate;
645 int ssh1_protocol_crstate;
646 int do_ssh1_login_crstate;
647 int do_ssh2_transport_crstate;
648 int do_ssh2_authconn_crstate;
649
650 void *do_ssh_init_state;
651 void *do_ssh1_login_state;
652 void *do_ssh2_transport_state;
653 void *do_ssh2_authconn_state;
654
655 struct rdpkt1_state_tag rdpkt1_state;
656 struct rdpkt2_state_tag rdpkt2_state;
657
658 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
659 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 660
661 /*
662 * We maintain a full _copy_ of a Config structure here, not
663 * merely a pointer to it. That way, when we're passed a new
664 * one for reconfiguration, we can check the differences and
665 * potentially reconfigure port forwardings etc in mid-session.
666 */
667 Config cfg;
839f10db 668
669 /*
670 * Used to transfer data back from async agent callbacks.
671 */
672 void *agent_response;
673 int agent_response_len;
51470298 674};
960e736a 675
382908ad 676#define logevent(s) logevent(ssh->frontend, s)
a8327734 677
678/* logevent, only printf-formatted. */
cbe2d68f 679static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 680{
681 va_list ap;
57356d63 682 char *buf;
a8327734 683
684 va_start(ap, fmt);
57356d63 685 buf = dupvprintf(fmt, ap);
a8327734 686 va_end(ap);
57356d63 687 logevent(buf);
57356d63 688 sfree(buf);
a8327734 689}
690
6b5cf8b4 691#define bombout(msg) \
692 do { \
693 char *text = dupprintf msg; \
36f94d1f 694 ssh_do_close(ssh); \
6b5cf8b4 695 logevent(text); \
696 connection_fatal(ssh->frontend, "%s", text); \
697 sfree(text); \
698 } while (0)
a8327734 699
9a10ecf4 700/* Functions to leave bits out of the SSH packet log file. */
701
702static void dont_log_password(Ssh ssh, int blanktype)
703{
704 if (ssh->cfg.logomitpass)
705 ssh->pktout_logmode = blanktype;
706}
707
708static void dont_log_data(Ssh ssh, int blanktype)
709{
710 if (ssh->cfg.logomitdata)
711 ssh->pktout_logmode = blanktype;
712}
713
714static void end_log_omission(Ssh ssh)
715{
716 ssh->pktout_logmode = PKTLOG_EMIT;
717}
718
32874aea 719static int ssh_channelcmp(void *av, void *bv)
720{
721 struct ssh_channel *a = (struct ssh_channel *) av;
722 struct ssh_channel *b = (struct ssh_channel *) bv;
723 if (a->localid < b->localid)
724 return -1;
725 if (a->localid > b->localid)
726 return +1;
dacbd0e8 727 return 0;
728}
32874aea 729static int ssh_channelfind(void *av, void *bv)
730{
731 unsigned *a = (unsigned *) av;
732 struct ssh_channel *b = (struct ssh_channel *) bv;
733 if (*a < b->localid)
734 return -1;
735 if (*a > b->localid)
736 return +1;
dacbd0e8 737 return 0;
738}
739
bc240b21 740static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 741{
742 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
743 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
744 int i;
bc240b21 745 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 746 return i < 0 ? -1 : +1;
bc240b21 747 if (a->dport > b->dport)
748 return +1;
749 if (a->dport < b->dport)
750 return -1;
751 return 0;
752}
753
754static int ssh_rportcmp_ssh2(void *av, void *bv)
755{
756 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
757 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 758
bc240b21 759 if (a->sport > b->sport)
d74d141c 760 return +1;
bc240b21 761 if (a->sport < b->sport)
762 return -1;
d74d141c 763 return 0;
764}
765
51470298 766static int alloc_channel_id(Ssh ssh)
32874aea 767{
260f3dec 768 const unsigned CHANNEL_NUMBER_OFFSET = 256;
769 unsigned low, high, mid;
d2371c81 770 int tsize;
771 struct ssh_channel *c;
772
773 /*
774 * First-fit allocation of channel numbers: always pick the
775 * lowest unused one. To do this, binary-search using the
776 * counted B-tree to find the largest channel ID which is in a
777 * contiguous sequence from the beginning. (Precisely
778 * everything in that sequence must have ID equal to its tree
779 * index plus CHANNEL_NUMBER_OFFSET.)
780 */
51470298 781 tsize = count234(ssh->channels);
d2371c81 782
32874aea 783 low = -1;
784 high = tsize;
d2371c81 785 while (high - low > 1) {
786 mid = (high + low) / 2;
51470298 787 c = index234(ssh->channels, mid);
d2371c81 788 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
789 low = mid; /* this one is fine */
790 else
791 high = mid; /* this one is past it */
792 }
793 /*
794 * Now low points to either -1, or the tree index of the
795 * largest ID in the initial sequence.
796 */
797 {
798 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 799 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 800 }
801 return low + 1 + CHANNEL_NUMBER_OFFSET;
802}
803
9fab77dc 804static void c_write(Ssh ssh, const char *buf, int len)
32874aea 805{
67779be7 806 if ((flags & FLAG_STDERR)) {
32874aea 807 int i;
808 for (i = 0; i < len; i++)
809 if (buf[i] != '\r')
810 fputc(buf[i], stderr);
fb09bf1c 811 return;
812 }
51470298 813 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 814}
815
9fab77dc 816static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 817{
a209e957 818 int i;
819 for (i = 0; i < len; i++) {
32874aea 820 if (buf[i] == '\n')
51470298 821 c_write(ssh, "\r\n", 2);
32874aea 822 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 823 c_write(ssh, buf + i, 1);
a209e957 824 }
825}
826
9fab77dc 827static void c_write_str(Ssh ssh, const char *buf)
32874aea 828{
51470298 829 c_write(ssh, buf, strlen(buf));
1408a877 830}
831
fb09bf1c 832/*
833 * Collect incoming data in the incoming packet buffer.
e5574168 834 * Decipher and verify the packet when it is completely read.
835 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 836 * Update the *data and *datalen variables.
837 * Return the additional nr of bytes needed, or 0 when
838 * a complete packet is available.
839 */
51470298 840static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 841{
51470298 842 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 843
51470298 844 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 845
32874aea 846 next_packet:
37508af4 847
51470298 848 ssh->pktin.type = 0;
849 ssh->pktin.length = 0;
374330e2 850
57476f6b 851 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 852 while ((*datalen) == 0)
32874aea 853 crReturn(4 - st->i);
57476f6b 854 st->len = (st->len << 8) + **data;
fb09bf1c 855 (*data)++, (*datalen)--;
856 }
374330e2 857
57476f6b 858 st->pad = 8 - (st->len % 8);
859 st->biglen = st->len + st->pad;
51470298 860 ssh->pktin.length = st->len - 5;
fb09bf1c 861
ae0500e5 862 if (st->biglen < 0) {
863 bombout(("Extremely large packet length from server suggests"
864 " data stream corruption"));
865 crStop(0);
866 }
867
51470298 868 if (ssh->pktin.maxlen < st->biglen) {
869 ssh->pktin.maxlen = st->biglen;
3d88e64d 870 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
871 unsigned char);
fb09bf1c 872 }
374330e2 873
57476f6b 874 st->to_read = st->biglen;
51470298 875 st->p = ssh->pktin.data;
57476f6b 876 while (st->to_read > 0) {
32874aea 877 st->chunk = st->to_read;
fb09bf1c 878 while ((*datalen) == 0)
57476f6b 879 crReturn(st->to_read);
880 if (st->chunk > (*datalen))
881 st->chunk = (*datalen);
882 memcpy(st->p, *data, st->chunk);
883 *data += st->chunk;
884 *datalen -= st->chunk;
885 st->p += st->chunk;
886 st->to_read -= st->chunk;
fb09bf1c 887 }
374330e2 888
0183b242 889 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
890 st->biglen, NULL)) {
6b5cf8b4 891 bombout(("Network attack (CRC compensation) detected!"));
7ffdbc1a 892 crStop(0);
9a3a93a5 893 }
894
51470298 895 if (ssh->cipher)
371e569c 896 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
374330e2 897
71bedafe 898 st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4);
51470298 899 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
57476f6b 900 if (st->gotcrc != st->realcrc) {
6b5cf8b4 901 bombout(("Incorrect CRC received on packet"));
7ffdbc1a 902 crStop(0);
fb09bf1c 903 }
572f871e 904
51470298 905 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
0016d70b 906 ssh->pktin.savedpos = 0;
4ba9b64b 907
51470298 908 if (ssh->v1_compressing) {
4ba9b64b 909 unsigned char *decompblk;
910 int decomplen;
36b8d9bb 911 if (!zlib_decompress_block(ssh->sc_comp_ctx,
912 ssh->pktin.body - 1, ssh->pktin.length + 1,
913 &decompblk, &decomplen)) {
914 bombout(("Zlib decompression encountered invalid data"));
915 crStop(0);
916 }
4ba9b64b 917
51470298 918 if (ssh->pktin.maxlen < st->pad + decomplen) {
919 ssh->pktin.maxlen = st->pad + decomplen;
3d88e64d 920 ssh->pktin.data = sresize(ssh->pktin.data,
921 ssh->pktin.maxlen + APIEXTRA,
922 unsigned char);
51470298 923 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 924 }
925
51470298 926 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
dcbde236 927 sfree(decompblk);
51470298 928 ssh->pktin.length = decomplen - 1;
4ba9b64b 929 }
930
51470298 931 ssh->pktin.type = ssh->pktin.body[-1];
00db133f 932
9a10ecf4 933 /*
934 * Log incoming packet, possibly omitting sensitive fields.
935 */
936 if (ssh->logctx) {
937 int nblanks = 0;
938 struct logblank_t blank;
939 if (ssh->cfg.logomitdata) {
940 int do_blank = FALSE, blank_prefix = 0;
941 /* "Session data" packets - omit the data field */
942 if ((ssh->pktin.type == SSH1_SMSG_STDOUT_DATA) ||
943 (ssh->pktin.type == SSH1_SMSG_STDERR_DATA)) {
944 do_blank = TRUE; blank_prefix = 0;
945 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
946 do_blank = TRUE; blank_prefix = 4;
947 }
948 if (do_blank) {
949 blank.offset = blank_prefix;
950 blank.len = ssh->pktin.length;
951 blank.type = PKTLOG_OMIT;
952 nblanks = 1;
953 }
954 }
a8327734 955 log_packet(ssh->logctx,
956 PKT_INCOMING, ssh->pktin.type,
957 ssh1_pkt_type(ssh->pktin.type),
9a10ecf4 958 ssh->pktin.body, ssh->pktin.length,
959 nblanks, &blank);
960 }
00db133f 961
51470298 962 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
963 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
964 ssh->pktin.type == SSH1_MSG_DEBUG ||
965 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
966 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
967 long stringlen = GET_32BIT(ssh->pktin.body);
968 if (stringlen + 4 != ssh->pktin.length) {
6b5cf8b4 969 bombout(("Received data packet with bogus string length"));
7ffdbc1a 970 crStop(0);
32874aea 971 }
fb09bf1c 972 }
973
51470298 974 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 975 /* log debug message */
eb4504cc 976 char buf[512];
51470298 977 int stringlen = GET_32BIT(ssh->pktin.body);
eb4504cc 978 strcpy(buf, "Remote debug message: ");
979 if (stringlen > 480)
980 stringlen = 480;
51470298 981 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
3d63ca2e 982 buf[8 + stringlen] = '\0';
fb09bf1c 983 logevent(buf);
984 goto next_packet;
51470298 985 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 986 /* do nothing */
987 goto next_packet;
988 }
989
51470298 990 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
38c4a8da 991 /* log reason code in disconnect message */
992 char buf[256];
51470298 993 unsigned msglen = GET_32BIT(ssh->pktin.body);
260f3dec 994 unsigned nowlen;
38c4a8da 995 strcpy(buf, "Remote sent disconnect: ");
996 nowlen = strlen(buf);
32874aea 997 if (msglen > sizeof(buf) - nowlen - 1)
998 msglen = sizeof(buf) - nowlen - 1;
51470298 999 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
32874aea 1000 buf[nowlen + msglen] = '\0';
247308b5 1001 /* logevent(buf); (this is now done within the bombout macro) */
6b5cf8b4 1002 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
7ffdbc1a 1003 crStop(0);
38c4a8da 1004 }
1005
fb09bf1c 1006 crFinish(0);
1007}
1008
51470298 1009static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1010{
51470298 1011 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1012
51470298 1013 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1014
32874aea 1015 next_packet:
51470298 1016 ssh->pktin.type = 0;
1017 ssh->pktin.length = 0;
1018 if (ssh->sccipher)
1019 st->cipherblk = ssh->sccipher->blksize;
e5574168 1020 else
32874aea 1021 st->cipherblk = 8;
960e736a 1022 if (st->cipherblk < 8)
32874aea 1023 st->cipherblk = 8;
960e736a 1024
51470298 1025 if (ssh->pktin.maxlen < st->cipherblk) {
1026 ssh->pktin.maxlen = st->cipherblk;
3d88e64d 1027 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
1028 unsigned char);
e5574168 1029 }
1030
1031 /*
1032 * Acquire and decrypt the first block of the packet. This will
1033 * contain the length and padding details.
1034 */
32874aea 1035 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1036 while ((*datalen) == 0)
32874aea 1037 crReturn(st->cipherblk - st->i);
51470298 1038 ssh->pktin.data[st->i] = *(*data)++;
32874aea 1039 (*datalen)--;
e5574168 1040 }
4252c9cc 1041
51470298 1042 if (ssh->sccipher)
371e569c 1043 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1044 ssh->pktin.data, st->cipherblk);
e5574168 1045
1046 /*
1047 * Now get the length and padding figures.
1048 */
51470298 1049 st->len = GET_32BIT(ssh->pktin.data);
1050 st->pad = ssh->pktin.data[4];
e5574168 1051
1052 /*
717dc483 1053 * _Completely_ silly lengths should be stomped on before they
1054 * do us any more damage.
1055 */
1056 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 1057 bombout(("Incoming packet was garbled on decryption"));
7ffdbc1a 1058 crStop(0);
717dc483 1059 }
1060
1061 /*
e5574168 1062 * This enables us to deduce the payload length.
1063 */
960e736a 1064 st->payload = st->len - st->pad - 1;
e5574168 1065
51470298 1066 ssh->pktin.length = st->payload + 5;
e5574168 1067
1068 /*
1069 * So now we can work out the total packet length.
1070 */
960e736a 1071 st->packetlen = st->len + 4;
51470298 1072 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1073
1074 /*
1075 * Adjust memory allocation if packet is too big.
1076 */
51470298 1077 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1078 ssh->pktin.maxlen = st->packetlen + st->maclen;
3d88e64d 1079 ssh->pktin.data = sresize(ssh->pktin.data,
1080 ssh->pktin.maxlen + APIEXTRA,
1081 unsigned char);
e5574168 1082 }
1083
1084 /*
1085 * Read and decrypt the remainder of the packet.
1086 */
32874aea 1087 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1088 st->i++) {
e5574168 1089 while ((*datalen) == 0)
960e736a 1090 crReturn(st->packetlen + st->maclen - st->i);
51470298 1091 ssh->pktin.data[st->i] = *(*data)++;
32874aea 1092 (*datalen)--;
e5574168 1093 }
1094 /* Decrypt everything _except_ the MAC. */
51470298 1095 if (ssh->sccipher)
371e569c 1096 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1097 ssh->pktin.data + st->cipherblk,
51470298 1098 st->packetlen - st->cipherblk);
e5574168 1099
1100 /*
1101 * Check the MAC.
1102 */
51470298 1103 if (ssh->scmac
e0e1a00d 1104 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
51470298 1105 st->incoming_sequence)) {
6b5cf8b4 1106 bombout(("Incorrect MAC received on packet"));
7ffdbc1a 1107 crStop(0);
8d5de777 1108 }
32874aea 1109 st->incoming_sequence++; /* whether or not we MACed */
e5574168 1110
4ba9b64b 1111 /*
1112 * Decompress packet payload.
1113 */
1114 {
1115 unsigned char *newpayload;
1116 int newlen;
51470298 1117 if (ssh->sccomp &&
5366aed8 1118 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1119 ssh->pktin.data + 5, ssh->pktin.length - 5,
51470298 1120 &newpayload, &newlen)) {
1121 if (ssh->pktin.maxlen < newlen + 5) {
1122 ssh->pktin.maxlen = newlen + 5;
3d88e64d 1123 ssh->pktin.data = sresize(ssh->pktin.data,
1124 ssh->pktin.maxlen + APIEXTRA,
1125 unsigned char);
4ba9b64b 1126 }
51470298 1127 ssh->pktin.length = 5 + newlen;
1128 memcpy(ssh->pktin.data + 5, newpayload, newlen);
dcbde236 1129 sfree(newpayload);
4ba9b64b 1130 }
1131 }
1132
51470298 1133 ssh->pktin.savedpos = 6;
0016d70b 1134 ssh->pktin.body = ssh->pktin.data;
51470298 1135 ssh->pktin.type = ssh->pktin.data[5];
e5574168 1136
9a10ecf4 1137 /*
1138 * Log incoming packet, possibly omitting sensitive fields.
1139 */
1140 if (ssh->logctx) {
1141 int nblanks = 0;
1142 struct logblank_t blank;
1143 if (ssh->cfg.logomitdata) {
1144 int do_blank = FALSE, blank_prefix = 0;
1145 /* "Session data" packets - omit the data field */
1146 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA) {
1147 do_blank = TRUE; blank_prefix = 4;
1148 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1149 do_blank = TRUE; blank_prefix = 8;
1150 }
1151 if (do_blank) {
1152 blank.offset = blank_prefix;
1153 blank.len = (ssh->pktin.length-6) - blank_prefix;
1154 blank.type = PKTLOG_OMIT;
1155 nblanks = 1;
1156 }
1157 }
a8327734 1158 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1159 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
9a10ecf4 1160 ssh->pktin.data+6, ssh->pktin.length-6,
1161 nblanks, &blank);
1162 }
00db133f 1163
51470298 1164 switch (ssh->pktin.type) {
3d63ca2e 1165 /*
1166 * These packets we must handle instantly.
1167 */
1168 case SSH2_MSG_DISCONNECT:
1169 {
1170 /* log reason code in disconnect message */
57356d63 1171 char *buf;
1172 int nowlen;
51470298 1173 int reason = GET_32BIT(ssh->pktin.data + 6);
1174 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
57356d63 1175
3d63ca2e 1176 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
57356d63 1177 buf = dupprintf("Received disconnect message (%s)",
1178 ssh2_disconnect_reasons[reason]);
3d63ca2e 1179 } else {
57356d63 1180 buf = dupprintf("Received disconnect message (unknown"
1181 " type %d)", reason);
3d63ca2e 1182 }
1183 logevent(buf);
57356d63 1184 sfree(buf);
1185 buf = dupprintf("Disconnection message text: %n%.*s",
33b82b22 1186 &nowlen, msglen, ssh->pktin.data + 14);
3d63ca2e 1187 logevent(buf);
6b5cf8b4 1188 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
3d63ca2e 1189 reason,
1190 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1191 ssh2_disconnect_reasons[reason] : "unknown",
1192 buf+nowlen));
57356d63 1193 sfree(buf);
7ffdbc1a 1194 crStop(0);
3d63ca2e 1195 }
1196 break;
1197 case SSH2_MSG_IGNORE:
1198 goto next_packet;
1199 case SSH2_MSG_DEBUG:
1200 {
1201 /* log the debug message */
1202 char buf[512];
51470298 1203 /* int display = ssh->pktin.body[6]; */
1204 int stringlen = GET_32BIT(ssh->pktin.data+7);
3d63ca2e 1205 int prefix;
1206 strcpy(buf, "Remote debug message: ");
1207 prefix = strlen(buf);
51470298 1208 if (stringlen > (int)(sizeof(buf)-prefix-1))
3d63ca2e 1209 stringlen = sizeof(buf)-prefix-1;
51470298 1210 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
3d63ca2e 1211 buf[prefix + stringlen] = '\0';
1212 logevent(buf);
38c4a8da 1213 }
3d63ca2e 1214 goto next_packet; /* FIXME: print the debug message */
1215
1216 /*
1217 * These packets we need do nothing about here.
1218 */
1219 case SSH2_MSG_UNIMPLEMENTED:
1220 case SSH2_MSG_SERVICE_REQUEST:
1221 case SSH2_MSG_SERVICE_ACCEPT:
1222 case SSH2_MSG_KEXINIT:
1223 case SSH2_MSG_NEWKEYS:
1224 case SSH2_MSG_KEXDH_INIT:
1225 case SSH2_MSG_KEXDH_REPLY:
1226 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1227 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1228 case SSH2_MSG_KEX_DH_GEX_INIT:
1229 case SSH2_MSG_KEX_DH_GEX_REPLY:
1230 case SSH2_MSG_USERAUTH_REQUEST:
1231 case SSH2_MSG_USERAUTH_FAILURE:
1232 case SSH2_MSG_USERAUTH_SUCCESS:
1233 case SSH2_MSG_USERAUTH_BANNER:
1234 case SSH2_MSG_USERAUTH_PK_OK:
1235 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1236 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1237 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1238 case SSH2_MSG_GLOBAL_REQUEST:
1239 case SSH2_MSG_REQUEST_SUCCESS:
1240 case SSH2_MSG_REQUEST_FAILURE:
1241 case SSH2_MSG_CHANNEL_OPEN:
1242 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1243 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1244 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1245 case SSH2_MSG_CHANNEL_DATA:
1246 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1247 case SSH2_MSG_CHANNEL_EOF:
1248 case SSH2_MSG_CHANNEL_CLOSE:
1249 case SSH2_MSG_CHANNEL_REQUEST:
1250 case SSH2_MSG_CHANNEL_SUCCESS:
1251 case SSH2_MSG_CHANNEL_FAILURE:
1252 break;
1253
1254 /*
1255 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1256 */
1257 default:
51470298 1258 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1259 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1260 ssh2_pkt_send(ssh);
3d63ca2e 1261 break;
38c4a8da 1262 }
1263
e5574168 1264 crFinish(0);
1265}
1266
51470298 1267static void ssh1_pktout_size(Ssh ssh, int len)
32874aea 1268{
374330e2 1269 int pad, biglen;
1270
1271 len += 5; /* type and CRC */
32874aea 1272 pad = 8 - (len % 8);
374330e2 1273 biglen = len + pad;
1274
51470298 1275 ssh->pktout.length = len - 5;
1276 if (ssh->pktout.maxlen < biglen) {
1277 ssh->pktout.maxlen = biglen;
8f203108 1278#ifdef MSCRYPTOAPI
fb09bf1c 1279 /* Allocate enough buffer space for extra block
8f203108 1280 * for MS CryptEncrypt() */
3d88e64d 1281 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1282 unsigned char);
8f203108 1283#else
3d88e64d 1284 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1285 unsigned char);
8f203108 1286#endif
374330e2 1287 }
51470298 1288 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
4ba9b64b 1289}
374330e2 1290
51470298 1291static void s_wrpkt_start(Ssh ssh, int type, int len)
32874aea 1292{
51470298 1293 ssh1_pktout_size(ssh, len);
1294 ssh->pktout.type = type;
9a10ecf4 1295 /* Initialise log omission state */
1296 ssh->pktout_nblanks = 0;
1297 ssh->pktout_blanks = NULL;
374330e2 1298}
1299
51470298 1300static int s_wrpkt_prepare(Ssh ssh)
32874aea 1301{
fd7a4aad 1302 int pad, biglen, i;
374330e2 1303 unsigned long crc;
fd7a4aad 1304#ifdef __SC__
1305 /*
1306 * XXX various versions of SC (including 8.8.4) screw up the
1307 * register allocation in this function and use the same register
1308 * (D6) for len and as a temporary, with predictable results. The
1309 * following sledgehammer prevents this.
1310 */
1311 volatile
1312#endif
1313 int len;
374330e2 1314
51470298 1315 ssh->pktout.body[-1] = ssh->pktout.type;
4ba9b64b 1316
a8327734 1317 if (ssh->logctx)
1318 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1319 ssh1_pkt_type(ssh->pktout.type),
9a10ecf4 1320 ssh->pktout.body, ssh->pktout.length,
1321 ssh->pktout_nblanks, ssh->pktout_blanks);
1322 sfree(ssh->pktout_blanks); ssh->pktout_blanks = NULL;
1323 ssh->pktout_nblanks = 0;
00db133f 1324
51470298 1325 if (ssh->v1_compressing) {
4ba9b64b 1326 unsigned char *compblk;
1327 int complen;
5366aed8 1328 zlib_compress_block(ssh->cs_comp_ctx,
1329 ssh->pktout.body - 1, ssh->pktout.length + 1,
4ba9b64b 1330 &compblk, &complen);
51470298 1331 ssh1_pktout_size(ssh, complen - 1);
1332 memcpy(ssh->pktout.body - 1, compblk, complen);
dcbde236 1333 sfree(compblk);
4ba9b64b 1334 }
1335
51470298 1336 len = ssh->pktout.length + 5; /* type and CRC */
32874aea 1337 pad = 8 - (len % 8);
374330e2 1338 biglen = len + pad;
1339
32874aea 1340 for (i = 0; i < pad; i++)
51470298 1341 ssh->pktout.data[i + 4] = random_byte();
71bedafe 1342 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
51470298 1343 PUT_32BIT(ssh->pktout.data + biglen, crc);
1344 PUT_32BIT(ssh->pktout.data, len);
374330e2 1345
51470298 1346 if (ssh->cipher)
371e569c 1347 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
374330e2 1348
32874aea 1349 return biglen + 4;
39065bed 1350}
1351
51470298 1352static void s_wrpkt(Ssh ssh)
32874aea 1353{
5471d09a 1354 int len, backlog;
51470298 1355 len = s_wrpkt_prepare(ssh);
d8baa528 1356 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1357 if (backlog > SSH_MAX_BACKLOG)
51470298 1358 ssh_throttle_all(ssh, 1, backlog);
39065bed 1359}
1360
51470298 1361static void s_wrpkt_defer(Ssh ssh)
32874aea 1362{
39065bed 1363 int len;
51470298 1364 len = s_wrpkt_prepare(ssh);
1365 if (ssh->deferred_len + len > ssh->deferred_size) {
1366 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1367 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1368 ssh->deferred_size,
1369 unsigned char);
39065bed 1370 }
51470298 1371 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1372 ssh->deferred_len += len;
374330e2 1373}
1374
fb09bf1c 1375/*
39065bed 1376 * Construct a packet with the specified contents.
fb09bf1c 1377 */
51470298 1378static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1379{
fb09bf1c 1380 unsigned char *p, *argp, argchar;
1381 unsigned long argint;
1382 int pktlen, argtype, arglen;
7cca0d81 1383 Bignum bn;
fb09bf1c 1384
1385 pktlen = 0;
39065bed 1386 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1387 switch (argtype) {
1388 case PKT_INT:
39065bed 1389 (void) va_arg(ap1, int);
fb09bf1c 1390 pktlen += 4;
1391 break;
1392 case PKT_CHAR:
1ec39246 1393 (void) va_arg(ap1, int);
fb09bf1c 1394 pktlen++;
1395 break;
1396 case PKT_DATA:
39065bed 1397 (void) va_arg(ap1, unsigned char *);
1398 arglen = va_arg(ap1, int);
fb09bf1c 1399 pktlen += arglen;
1400 break;
1401 case PKT_STR:
39065bed 1402 argp = va_arg(ap1, unsigned char *);
d8baa528 1403 arglen = strlen((char *)argp);
fb09bf1c 1404 pktlen += 4 + arglen;
1405 break;
7cca0d81 1406 case PKT_BIGNUM:
39065bed 1407 bn = va_arg(ap1, Bignum);
32874aea 1408 pktlen += ssh1_bignum_length(bn);
7cca0d81 1409 break;
9a10ecf4 1410 case PKTT_PASSWORD:
1411 case PKTT_DATA:
1412 case PKTT_OTHER:
1413 /* ignore this pass */
1414 break;
fb09bf1c 1415 default:
1416 assert(0);
1417 }
1418 }
fb09bf1c 1419
51470298 1420 s_wrpkt_start(ssh, pkttype, pktlen);
1421 p = ssh->pktout.body;
fb09bf1c 1422
39065bed 1423 while ((argtype = va_arg(ap2, int)) != PKT_END) {
9a10ecf4 1424 int offset = p - ssh->pktout.body, len = 0;
fb09bf1c 1425 switch (argtype) {
9a10ecf4 1426 /* Actual fields in the packet */
fb09bf1c 1427 case PKT_INT:
39065bed 1428 argint = va_arg(ap2, int);
fb09bf1c 1429 PUT_32BIT(p, argint);
9a10ecf4 1430 len = 4;
fb09bf1c 1431 break;
1432 case PKT_CHAR:
1ec39246 1433 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1434 *p = argchar;
9a10ecf4 1435 len = 1;
fb09bf1c 1436 break;
1437 case PKT_DATA:
39065bed 1438 argp = va_arg(ap2, unsigned char *);
1439 arglen = va_arg(ap2, int);
fb09bf1c 1440 memcpy(p, argp, arglen);
9a10ecf4 1441 len = arglen;
fb09bf1c 1442 break;
1443 case PKT_STR:
39065bed 1444 argp = va_arg(ap2, unsigned char *);
d8baa528 1445 arglen = strlen((char *)argp);
fb09bf1c 1446 PUT_32BIT(p, arglen);
1447 memcpy(p + 4, argp, arglen);
9a10ecf4 1448 len = arglen + 4;
fb09bf1c 1449 break;
7cca0d81 1450 case PKT_BIGNUM:
39065bed 1451 bn = va_arg(ap2, Bignum);
9a10ecf4 1452 len = ssh1_write_bignum(p, bn);
1453 break;
1454 /* Tokens for modifications to packet logging */
1455 case PKTT_PASSWORD:
1456 dont_log_password(ssh, PKTLOG_BLANK);
1457 break;
1458 case PKTT_DATA:
1459 dont_log_data(ssh, PKTLOG_OMIT);
7cca0d81 1460 break;
9a10ecf4 1461 case PKTT_OTHER:
1462 end_log_omission(ssh);
1463 break;
1464 }
1465 p += len;
1466 /* Deal with logfile omission, if required. */
1467 if (len && (ssh->pktout_logmode != PKTLOG_EMIT)) {
1468 ssh->pktout_nblanks++;
1469 ssh->pktout_blanks = sresize(ssh->pktout_blanks,
1470 ssh->pktout_nblanks,
1471 struct logblank_t);
1472 ssh->pktout_blanks[ssh->pktout_nblanks-1].offset = offset;
1473 ssh->pktout_blanks[ssh->pktout_nblanks-1].len = len;
1474 ssh->pktout_blanks[ssh->pktout_nblanks-1].type =
1475 ssh->pktout_logmode;
fb09bf1c 1476 }
1477 }
39065bed 1478}
fb09bf1c 1479
51470298 1480static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1481{
39065bed 1482 va_list ap1, ap2;
1483 va_start(ap1, pkttype);
1484 va_start(ap2, pkttype);
51470298 1485 construct_packet(ssh, pkttype, ap1, ap2);
1486 s_wrpkt(ssh);
fb09bf1c 1487}
1488
51470298 1489static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1490{
39065bed 1491 va_list ap1, ap2;
1492 va_start(ap1, pkttype);
1493 va_start(ap2, pkttype);
51470298 1494 construct_packet(ssh, pkttype, ap1, ap2);
1495 s_wrpkt_defer(ssh);
39065bed 1496}
1497
32874aea 1498static int ssh_versioncmp(char *a, char *b)
1499{
9697bfd2 1500 char *ae, *be;
1501 unsigned long av, bv;
1502
43aa02a7 1503 av = strtoul(a, &ae, 10);
1504 bv = strtoul(b, &be, 10);
32874aea 1505 if (av != bv)
1506 return (av < bv ? -1 : +1);
1507 if (*ae == '.')
1508 ae++;
1509 if (*be == '.')
1510 be++;
43aa02a7 1511 av = strtoul(ae, &ae, 10);
1512 bv = strtoul(be, &be, 10);
32874aea 1513 if (av != bv)
1514 return (av < bv ? -1 : +1);
9697bfd2 1515 return 0;
1516}
1517
e5574168 1518/*
a92dd380 1519 * Utility routines for putting an SSH-protocol `string' and
1520 * `uint32' into a SHA state.
e5574168 1521 */
1522#include <stdio.h>
32874aea 1523static void sha_string(SHA_State * s, void *str, int len)
1524{
e5574168 1525 unsigned char lenblk[4];
e5574168 1526 PUT_32BIT(lenblk, len);
e5574168 1527 SHA_Bytes(s, lenblk, 4);
e5574168 1528 SHA_Bytes(s, str, len);
1529}
1530
32874aea 1531static void sha_uint32(SHA_State * s, unsigned i)
1532{
a92dd380 1533 unsigned char intblk[4];
1534 PUT_32BIT(intblk, i);
1535 SHA_Bytes(s, intblk, 4);
1536}
1537
7cca0d81 1538/*
1539 * SSH2 packet construction functions.
1540 */
51470298 1541static void ssh2_pkt_ensure(Ssh ssh, int length)
32874aea 1542{
51470298 1543 if (ssh->pktout.maxlen < length) {
1544 ssh->pktout.maxlen = length + 256;
3d88e64d 1545 ssh->pktout.data = sresize(ssh->pktout.data,
1546 ssh->pktout.maxlen + APIEXTRA,
1547 unsigned char);
51470298 1548 if (!ssh->pktout.data)
32874aea 1549 fatalbox("Out of memory");
7cca0d81 1550 }
783415f8 1551}
51470298 1552static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
32874aea 1553{
9a10ecf4 1554 if (ssh->pktout_logmode != PKTLOG_EMIT) {
1555 ssh->pktout_nblanks++;
1556 ssh->pktout_blanks = sresize(ssh->pktout_blanks, ssh->pktout_nblanks,
1557 struct logblank_t);
1558 ssh->pktout_blanks[ssh->pktout_nblanks-1].offset =
1559 ssh->pktout.length - 6;
1560 ssh->pktout_blanks[ssh->pktout_nblanks-1].len = len;
1561 ssh->pktout_blanks[ssh->pktout_nblanks-1].type = ssh->pktout_logmode;
1562 }
51470298 1563 ssh->pktout.length += len;
1564 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1565 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
7cca0d81 1566}
51470298 1567static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
32874aea 1568{
51470298 1569 ssh2_pkt_adddata(ssh, &byte, 1);
7cca0d81 1570}
51470298 1571static void ssh2_pkt_init(Ssh ssh, int pkt_type)
32874aea 1572{
51470298 1573 ssh->pktout.length = 5;
9a10ecf4 1574 ssh->pktout_nblanks = 0; ssh->pktout_blanks = NULL;
51470298 1575 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
7cca0d81 1576}
51470298 1577static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
32874aea 1578{
51470298 1579 ssh2_pkt_adddata(ssh, &value, 1);
7cca0d81 1580}
51470298 1581static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
32874aea 1582{
7cca0d81 1583 unsigned char x[4];
1584 PUT_32BIT(x, value);
51470298 1585 ssh2_pkt_adddata(ssh, x, 4);
7cca0d81 1586}
51470298 1587static void ssh2_pkt_addstring_start(Ssh ssh)
32874aea 1588{
51470298 1589 ssh2_pkt_adduint32(ssh, 0);
1590 ssh->pktout.savedpos = ssh->pktout.length;
7cca0d81 1591}
51470298 1592static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
32874aea 1593{
51470298 1594 ssh2_pkt_adddata(ssh, data, strlen(data));
1595 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1596 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1597}
51470298 1598static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
32874aea 1599{
51470298 1600 ssh2_pkt_adddata(ssh, data, len);
1601 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1602 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1603}
51470298 1604static void ssh2_pkt_addstring(Ssh ssh, char *data)
32874aea 1605{
51470298 1606 ssh2_pkt_addstring_start(ssh);
1607 ssh2_pkt_addstring_str(ssh, data);
7cca0d81 1608}
d8baa528 1609static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1610{
7cca0d81 1611 unsigned char *p;
32874aea 1612 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1613 p = snewn(n + 1, unsigned char);
7cca0d81 1614 if (!p)
32874aea 1615 fatalbox("out of memory");
7cca0d81 1616 p[0] = 0;
3709bfe9 1617 for (i = 1; i <= n; i++)
32874aea 1618 p[i] = bignum_byte(b, n - i);
7cca0d81 1619 i = 0;
32874aea 1620 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1621 i++;
1622 memmove(p, p + i, n + 1 - i);
1623 *len = n + 1 - i;
7cca0d81 1624 return p;
1625}
51470298 1626static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
32874aea 1627{
7cca0d81 1628 unsigned char *p;
1629 int len;
1630 p = ssh2_mpint_fmt(b, &len);
51470298 1631 ssh2_pkt_addstring_start(ssh);
d8baa528 1632 ssh2_pkt_addstring_data(ssh, (char *)p, len);
dcbde236 1633 sfree(p);
7cca0d81 1634}
b185170a 1635
1636/*
1637 * Construct an SSH2 final-form packet: compress it, encrypt it,
1638 * put the MAC on it. Final packet, ready to be sent, is stored in
51470298 1639 * ssh->pktout.data. Total length is returned.
b185170a 1640 */
51470298 1641static int ssh2_pkt_construct(Ssh ssh)
32874aea 1642{
7cca0d81 1643 int cipherblk, maclen, padding, i;
7cca0d81 1644
a8327734 1645 if (ssh->logctx)
1646 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1647 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
9a10ecf4 1648 ssh->pktout.data + 6, ssh->pktout.length - 6,
1649 ssh->pktout_nblanks, ssh->pktout_blanks);
1650 sfree(ssh->pktout_blanks); ssh->pktout_blanks = NULL;
1651 ssh->pktout_nblanks = 0;
00db133f 1652
7cca0d81 1653 /*
4ba9b64b 1654 * Compress packet payload.
1655 */
4ba9b64b 1656 {
1657 unsigned char *newpayload;
1658 int newlen;
51470298 1659 if (ssh->cscomp &&
5366aed8 1660 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1661 ssh->pktout.length - 5,
51470298 1662 &newpayload, &newlen)) {
1663 ssh->pktout.length = 5;
1664 ssh2_pkt_adddata(ssh, newpayload, newlen);
dcbde236 1665 sfree(newpayload);
4ba9b64b 1666 }
1667 }
1668
1669 /*
7cca0d81 1670 * Add padding. At least four bytes, and must also bring total
1671 * length (minus MAC) up to a multiple of the block size.
1672 */
51470298 1673 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1674 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1675 padding = 4;
32874aea 1676 padding +=
51470298 1677 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1678 maclen = ssh->csmac ? ssh->csmac->len : 0;
1679 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1680 ssh->pktout.data[4] = padding;
7cca0d81 1681 for (i = 0; i < padding; i++)
51470298 1682 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1683 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1684 if (ssh->csmac)
e0e1a00d 1685 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1686 ssh->pktout.length + padding,
51470298 1687 ssh->v2_outgoing_sequence);
1688 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1689
1690 if (ssh->cscipher)
371e569c 1691 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1692 ssh->pktout.data, ssh->pktout.length + padding);
51470298 1693
1694 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1695 return ssh->pktout.length + padding + maclen;
b185170a 1696}
1697
1698/*
1699 * Construct and send an SSH2 packet immediately.
1700 */
51470298 1701static void ssh2_pkt_send(Ssh ssh)
32874aea 1702{
5471d09a 1703 int len;
1704 int backlog;
51470298 1705 len = ssh2_pkt_construct(ssh);
d8baa528 1706 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1707 if (backlog > SSH_MAX_BACKLOG)
51470298 1708 ssh_throttle_all(ssh, 1, backlog);
b185170a 1709}
1710
1711/*
1712 * Construct an SSH2 packet and add it to a deferred data block.
1713 * Useful for sending multiple packets in a single sk_write() call,
1714 * to prevent a traffic-analysing listener from being able to work
1715 * out the length of any particular packet (such as the password
1716 * packet).
1717 *
1718 * Note that because SSH2 sequence-numbers its packets, this can
1719 * NOT be used as an m4-style `defer' allowing packets to be
1720 * constructed in one order and sent in another.
1721 */
51470298 1722static void ssh2_pkt_defer(Ssh ssh)
32874aea 1723{
51470298 1724 int len = ssh2_pkt_construct(ssh);
1725 if (ssh->deferred_len + len > ssh->deferred_size) {
1726 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1727 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1728 ssh->deferred_size,
1729 unsigned char);
b185170a 1730 }
51470298 1731 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1732 ssh->deferred_len += len;
b185170a 1733}
1734
1735/*
1736 * Send the whole deferred data block constructed by
39065bed 1737 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1738 */
51470298 1739static void ssh_pkt_defersend(Ssh ssh)
32874aea 1740{
5471d09a 1741 int backlog;
d8baa528 1742 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1743 ssh->deferred_len);
51470298 1744 ssh->deferred_len = ssh->deferred_size = 0;
1745 sfree(ssh->deferred_send_data);
1746 ssh->deferred_send_data = NULL;
5471d09a 1747 if (backlog > SSH_MAX_BACKLOG)
51470298 1748 ssh_throttle_all(ssh, 1, backlog);
7cca0d81 1749}
1750
1751#if 0
32874aea 1752void bndebug(char *string, Bignum b)
1753{
7cca0d81 1754 unsigned char *p;
1755 int i, len;
1756 p = ssh2_mpint_fmt(b, &len);
1757 debug(("%s", string));
1758 for (i = 0; i < len; i++)
32874aea 1759 debug((" %02x", p[i]));
765c4200 1760 debug(("\n"));
dcbde236 1761 sfree(p);
7cca0d81 1762}
1763#endif
1764
32874aea 1765static void sha_mpint(SHA_State * s, Bignum b)
1766{
7cca0d81 1767 unsigned char *p;
1768 int len;
1769 p = ssh2_mpint_fmt(b, &len);
1770 sha_string(s, p, len);
dcbde236 1771 sfree(p);
7cca0d81 1772}
1773
1774/*
0016d70b 1775 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1776 */
0016d70b 1777static unsigned long ssh_pkt_getuint32(Ssh ssh)
32874aea 1778{
7cca0d81 1779 unsigned long value;
51470298 1780 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1781 return 0; /* arrgh, no way to decline (FIXME?) */
0016d70b 1782 value = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
51470298 1783 ssh->pktin.savedpos += 4;
7cca0d81 1784 return value;
1785}
51470298 1786static int ssh2_pkt_getbool(Ssh ssh)
32874aea 1787{
65a22376 1788 unsigned long value;
51470298 1789 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
32874aea 1790 return 0; /* arrgh, no way to decline (FIXME?) */
0016d70b 1791 value = ssh->pktin.body[ssh->pktin.savedpos] != 0;
51470298 1792 ssh->pktin.savedpos++;
65a22376 1793 return value;
1794}
0016d70b 1795static void ssh_pkt_getstring(Ssh ssh, char **p, int *length)
32874aea 1796{
57356d63 1797 int len;
7cca0d81 1798 *p = NULL;
45068b27 1799 *length = 0;
51470298 1800 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1801 return;
0016d70b 1802 len = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
57356d63 1803 if (len < 0)
1804 return;
1805 *length = len;
51470298 1806 ssh->pktin.savedpos += 4;
1807 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
32874aea 1808 return;
0016d70b 1809 *p = (char *)(ssh->pktin.body + ssh->pktin.savedpos);
51470298 1810 ssh->pktin.savedpos += *length;
7cca0d81 1811}
0016d70b 1812static void *ssh_pkt_getdata(Ssh ssh, int length)
1813{
1814 if (ssh->pktin.length - ssh->pktin.savedpos < length)
1815 return NULL;
1816 ssh->pktin.savedpos += length;
1817 return ssh->pktin.body + (ssh->pktin.savedpos - length);
1818}
1819static int ssh1_pkt_getrsakey(Ssh ssh, struct RSAKey *key,
1820 unsigned char **keystr)
1821{
1822 int j;
1823
1824 j = makekey(ssh->pktin.body + ssh->pktin.savedpos,
1825 ssh->pktin.length - ssh->pktin.savedpos,
1826 key, keystr, 0);
1827
1828 if (j < 0)
1829 return FALSE;
1830
1831 ssh->pktin.savedpos += j;
1832 assert(ssh->pktin.savedpos < ssh->pktin.length);
1833
1834 return TRUE;
1835}
1836static Bignum ssh1_pkt_getmp(Ssh ssh)
1837{
1838 int j;
1839 Bignum b;
1840
1841 j = ssh1_read_bignum(ssh->pktin.body + ssh->pktin.savedpos,
1842 ssh->pktin.length - ssh->pktin.savedpos, &b);
1843
1844 if (j < 0)
1845 return NULL;
1846
1847 ssh->pktin.savedpos += j;
1848 return b;
1849}
51470298 1850static Bignum ssh2_pkt_getmp(Ssh ssh)
32874aea 1851{
7cca0d81 1852 char *p;
3709bfe9 1853 int length;
7cca0d81 1854 Bignum b;
1855
0016d70b 1856 ssh_pkt_getstring(ssh, &p, &length);
7cca0d81 1857 if (!p)
32874aea 1858 return NULL;
8d5de777 1859 if (p[0] & 0x80) {
6b5cf8b4 1860 bombout(("internal error: Can't handle negative mpints"));
32874aea 1861 return NULL;
8d5de777 1862 }
d8baa528 1863 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1864 return b;
1865}
1866
7d503c31 1867/*
1dd353b5 1868 * Helper function to add an SSH2 signature blob to a packet.
1869 * Expects to be shown the public key blob as well as the signature
1870 * blob. Normally works just like ssh2_pkt_addstring, but will
1871 * fiddle with the signature packet if necessary for
1872 * BUG_SSH2_RSA_PADDING.
1873 */
51470298 1874static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1dd353b5 1875 void *sigblob_v, int sigblob_len)
1876{
1877 unsigned char *pkblob = (unsigned char *)pkblob_v;
1878 unsigned char *sigblob = (unsigned char *)sigblob_v;
1879
1880 /* dmemdump(pkblob, pkblob_len); */
1881 /* dmemdump(sigblob, sigblob_len); */
1882
1883 /*
1884 * See if this is in fact an ssh-rsa signature and a buggy
1885 * server; otherwise we can just do this the easy way.
1886 */
51470298 1887 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1888 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1889 int pos, len, siglen;
1890
1891 /*
1892 * Find the byte length of the modulus.
1893 */
1894
1895 pos = 4+7; /* skip over "ssh-rsa" */
1896 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1897 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1898 pos += 4; /* find modulus itself */
1899 while (len > 0 && pkblob[pos] == 0)
1900 len--, pos++;
1901 /* debug(("modulus length is %d\n", len)); */
1902
1903 /*
1904 * Now find the signature integer.
1905 */
1906 pos = 4+7; /* skip over "ssh-rsa" */
1907 siglen = GET_32BIT(sigblob+pos);
1908 /* debug(("signature length is %d\n", siglen)); */
1909
1910 if (len != siglen) {
1911 unsigned char newlen[4];
51470298 1912 ssh2_pkt_addstring_start(ssh);
d8baa528 1913 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1dd353b5 1914 /* dmemdump(sigblob, pos); */
1915 pos += 4; /* point to start of actual sig */
1916 PUT_32BIT(newlen, len);
d8baa528 1917 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1dd353b5 1918 /* dmemdump(newlen, 4); */
1919 newlen[0] = 0;
1920 while (len-- > siglen) {
d8baa528 1921 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1dd353b5 1922 /* dmemdump(newlen, 1); */
1923 }
d8baa528 1924 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1dd353b5 1925 /* dmemdump(sigblob+pos, siglen); */
1926 return;
1927 }
1928
1929 /* Otherwise fall through and do it the easy way. */
1930 }
1931
51470298 1932 ssh2_pkt_addstring_start(ssh);
d8baa528 1933 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1dd353b5 1934}
1935
1936/*
7d503c31 1937 * Examine the remote side's version string and compare it against
1938 * a list of known buggy implementations.
1939 */
51470298 1940static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1941{
1942 char *imp; /* pointer to implementation part */
7d503c31 1943 imp = vstring;
1944 imp += strcspn(imp, "-");
bd358db1 1945 if (*imp) imp++;
7d503c31 1946 imp += strcspn(imp, "-");
bd358db1 1947 if (*imp) imp++;
7d503c31 1948
51470298 1949 ssh->remote_bugs = 0;
7d503c31 1950
5ecd7ad0 1951 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1952 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 1953 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1954 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 1955 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 1956 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 1957 /*
1958 * These versions don't support SSH1_MSG_IGNORE, so we have
1959 * to use a different defence against password length
1960 * sniffing.
1961 */
51470298 1962 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1963 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1964 }
1965
5ecd7ad0 1966 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1967 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 1968 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 1969 /*
1970 * These versions need a plain password sent; they can't
1971 * handle having a null and a random length of data after
1972 * the password.
1973 */
51470298 1974 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1975 logevent("We believe remote version needs a plain SSH1 password");
1976 }
1977
5ecd7ad0 1978 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1979 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 1980 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1981 /*
1982 * These versions apparently have no clue whatever about
1983 * RSA authentication and will panic and die if they see
1984 * an AUTH_RSA message.
1985 */
51470298 1986 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 1987 logevent("We believe remote version can't handle RSA authentication");
1988 }
1989
5ecd7ad0 1990 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1991 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 1992 !wc_match("* VShell", imp) &&
831301f6 1993 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1994 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1995 wc_match("2.1 *", imp)))) {
32874aea 1996 /*
1997 * These versions have the HMAC bug.
1998 */
51470298 1999 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2000 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2001 }
1dd353b5 2002
5ecd7ad0 2003 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2004 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2005 !wc_match("* VShell", imp) &&
2856a1b9 2006 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2007 /*
2008 * These versions have the key-derivation bug (failing to
2009 * include the literal shared secret in the hashes that
2010 * generate the keys).
2011 */
51470298 2012 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2013 logevent("We believe remote version has SSH2 key-derivation bug");
2014 }
2015
5ecd7ad0 2016 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2017 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2018 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2019 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2020 /*
2021 * These versions have the SSH2 RSA padding bug.
2022 */
51470298 2023 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2024 logevent("We believe remote version has SSH2 RSA padding bug");
2025 }
8e975795 2026
dda87a28 2027 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2028 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2029 wc_match("OpenSSH_2.[0-2]*", imp))) {
2030 /*
2031 * These versions have the SSH2 session-ID bug in
2032 * public-key authentication.
2033 */
2034 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2035 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2036 }
2037
5ecd7ad0 2038 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
8e975795 2039 /*
831301f6 2040 * User specified the SSH2 DH GEX bug.
8e975795 2041 */
51470298 2042 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 2043 logevent("We believe remote version has SSH2 DH group exchange bug");
2044 }
7d503c31 2045}
2046
51470298 2047static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2048{
51470298 2049 struct do_ssh_init_state {
2050 int vslen;
2051 char version[10];
2052 char *vstring;
2053 int vstrsize;
2054 int i;
2055 int proto1, proto2;
2056 };
2057 crState(do_ssh_init_state);
374330e2 2058
51470298 2059 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2060
2061 /* Search for the string "SSH-" in the input. */
51470298 2062 s->i = 0;
8df7a775 2063 while (1) {
2064 static const int transS[] = { 1, 2, 2, 1 };
2065 static const int transH[] = { 0, 0, 3, 0 };
2066 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2067 if (c == 'S')
51470298 2068 s->i = transS[s->i];
32874aea 2069 else if (c == 'H')
51470298 2070 s->i = transH[s->i];
32874aea 2071 else if (c == '-')
51470298 2072 s->i = transminus[s->i];
32874aea 2073 else
51470298 2074 s->i = 0;
2075 if (s->i < 0)
8df7a775 2076 break;
2077 crReturn(1); /* get another character */
374330e2 2078 }
8df7a775 2079
51470298 2080 s->vstrsize = 16;
3d88e64d 2081 s->vstring = snewn(s->vstrsize, char);
51470298 2082 strcpy(s->vstring, "SSH-");
2083 s->vslen = 4;
2084 s->i = 0;
374330e2 2085 while (1) {
8df7a775 2086 crReturn(1); /* get another char */
51470298 2087 if (s->vslen >= s->vstrsize - 1) {
2088 s->vstrsize += 16;
3d88e64d 2089 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2090 }
51470298 2091 s->vstring[s->vslen++] = c;
2092 if (s->i >= 0) {
374330e2 2093 if (c == '-') {
51470298 2094 s->version[s->i] = '\0';
2095 s->i = -1;
2096 } else if (s->i < sizeof(s->version) - 1)
2097 s->version[s->i++] = c;
c4ffc4d0 2098 } else if (c == '\012')
374330e2 2099 break;
2100 }
2101
51470298 2102 ssh->agentfwd_enabled = FALSE;
2103 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2104
51470298 2105 s->vstring[s->vslen] = 0;
2106 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
2107 {
2108 char *vlog;
3d88e64d 2109 vlog = snewn(20 + s->vslen, char);
51470298 2110 sprintf(vlog, "Server version: %s", s->vstring);
2111 logevent(vlog);
2112 sfree(vlog);
2113 }
2114 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2115
adf799dd 2116 /*
38d228a2 2117 * Decide which SSH protocol version to support.
adf799dd 2118 */
38d228a2 2119
2120 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2121 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2122 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2123 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2124
86916870 2125 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2126 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2127 crStop(0);
38d228a2 2128 }
86916870 2129 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2130 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2131 crStop(0);
38d228a2 2132 }
2133
86916870 2134 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
32874aea 2135 /*
38d228a2 2136 * Use v2 protocol.
32874aea 2137 */
2138 char verstring[80], vlog[100];
2139 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 2140 SHA_Init(&ssh->exhashbase);
32874aea 2141 /*
2142 * Hash our version string and their version string.
2143 */
51470298 2144 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
2145 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 2146 sprintf(vlog, "We claim version: %s", verstring);
2147 logevent(vlog);
c4ffc4d0 2148 strcat(verstring, "\012");
32874aea 2149 logevent("Using SSH protocol version 2");
51470298 2150 sk_write(ssh->s, verstring, strlen(verstring));
2151 ssh->protocol = ssh2_protocol;
2152 ssh->version = 2;
2153 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 2154 } else {
32874aea 2155 /*
38d228a2 2156 * Use v1 protocol.
32874aea 2157 */
2158 char verstring[80], vlog[100];
2159 sprintf(verstring, "SSH-%s-%s",
51470298 2160 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 2161 sshver);
2162 sprintf(vlog, "We claim version: %s", verstring);
2163 logevent(vlog);
c4ffc4d0 2164 strcat(verstring, "\012");
759712a6 2165
32874aea 2166 logevent("Using SSH protocol version 1");
51470298 2167 sk_write(ssh->s, verstring, strlen(verstring));
2168 ssh->protocol = ssh1_protocol;
2169 ssh->version = 1;
2170 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 2171 }
125105d1 2172 update_specials_menu(ssh->frontend);
51470298 2173 ssh->state = SSH_STATE_BEFORE_SIZE;
8df7a775 2174
51470298 2175 sfree(s->vstring);
50526e47 2176
8df7a775 2177 crFinish(0);
2178}
2179
51470298 2180static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2181{
51470298 2182 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2183
2184 /*
2185 * To begin with, feed the characters one by one to the
2186 * protocol initialisation / selection function do_ssh_init().
2187 * When that returns 0, we're done with the initial greeting
2188 * exchange and can move on to packet discipline.
2189 */
2190 while (1) {
51470298 2191 int ret; /* need not be kept across crReturn */
8df7a775 2192 if (datalen == 0)
2193 crReturnV; /* more data please */
51470298 2194 ret = do_ssh_init(ssh, *data);
32874aea 2195 data++;
2196 datalen--;
8df7a775 2197 if (ret == 0)
2198 break;
2199 }
2200
2201 /*
2202 * We emerge from that loop when the initial negotiation is
2203 * over and we have selected an s_rdpkt function. Now pass
2204 * everything to s_rdpkt, and then pass the resulting packets
2205 * to the proper protocol handler.
2206 */
2207 if (datalen == 0)
2208 crReturnV;
2209 while (1) {
2210 while (datalen > 0) {
51470298 2211 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2212 if (ssh->state == SSH_STATE_CLOSED) {
e14d0f19 2213 return;
2214 }
51470298 2215 ssh->protocol(ssh, NULL, 0, 1);
2216 if (ssh->state == SSH_STATE_CLOSED) {
8df7a775 2217 return;
2218 }
2219 }
2220 }
2221 crReturnV;
2222 }
2223 crFinishV;
2224}
2225
36f94d1f 2226static void ssh_do_close(Ssh ssh)
32874aea 2227{
36f94d1f 2228 int i;
2229 struct ssh_channel *c;
2230
51470298 2231 ssh->state = SSH_STATE_CLOSED;
2232 if (ssh->s) {
2233 sk_close(ssh->s);
2234 ssh->s = NULL;
f3ab576e 2235 }
36f94d1f 2236 /*
2237 * Now we must shut down any port and X forwardings going
2238 * through this connection.
2239 */
74a98066 2240 if (ssh->channels) {
2241 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2242 switch (c->type) {
2243 case CHAN_X11:
2244 x11_close(c->u.x11.s);
2245 break;
2246 case CHAN_SOCKDATA:
2247 pfd_close(c->u.pfd.s);
2248 break;
2249 }
2250 del234(ssh->channels, c);
2251 if (ssh->version == 2)
2252 bufchain_clear(&c->v.v2.outbuffer);
2253 sfree(c);
36f94d1f 2254 }
36f94d1f 2255 }
2256}
2257
cbe2d68f 2258static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2259 int calling_back)
2260{
2261 Ssh ssh = (Ssh) plug;
2262 ssh_do_close(ssh);
7e78000d 2263 if (error_msg) {
32874aea 2264 /* A socket error has occurred. */
247308b5 2265 logevent(error_msg);
971bcc0a 2266 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2267 } else {
2268 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2269 }
7e78000d 2270 return 0;
2271}
2272
32874aea 2273static int ssh_receive(Plug plug, int urgent, char *data, int len)
2274{
51470298 2275 Ssh ssh = (Ssh) plug;
d8baa528 2276 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2277 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2278 ssh_do_close(ssh);
32874aea 2279 return 0;
3257deae 2280 }
fef97f43 2281 return 1;
374330e2 2282}
2283
5471d09a 2284static void ssh_sent(Plug plug, int bufsize)
2285{
51470298 2286 Ssh ssh = (Ssh) plug;
5471d09a 2287 /*
2288 * If the send backlog on the SSH socket itself clears, we
2289 * should unthrottle the whole world if it was throttled.
2290 */
2291 if (bufsize < SSH_MAX_BACKLOG)
51470298 2292 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2293}
2294
fb09bf1c 2295/*
8df7a775 2296 * Connect to specified host and port.
2297 * Returns an error message, or NULL on success.
6e1ebb76 2298 * Also places the canonical host name into `realhost'. It must be
2299 * freed by the caller.
8df7a775 2300 */
cbe2d68f 2301static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2302 char **realhost, int nodelay, int keepalive)
8df7a775 2303{
51470298 2304 static const struct plug_function_table fn_table = {
7e78000d 2305 ssh_closing,
5471d09a 2306 ssh_receive,
2307 ssh_sent,
2308 NULL
51470298 2309 };
7e78000d 2310
8df7a775 2311 SockAddr addr;
cbe2d68f 2312 const char *err;
8df7a775 2313
3d88e64d 2314 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2315 if (!ssh->savedhost)
8df7a775 2316 fatalbox("Out of memory");
51470298 2317 strcpy(ssh->savedhost, host);
8df7a775 2318
2319 if (port < 0)
2320 port = 22; /* default ssh port */
51470298 2321 ssh->savedport = port;
8df7a775 2322
2323 /*
2324 * Try to find host.
2325 */
57356d63 2326 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2327 addr = name_lookup(host, port, realhost, &ssh->cfg);
170c1e6e 2328 if ((err = sk_addr_error(addr)) != NULL) {
2329 sk_addr_free(addr);
8df7a775 2330 return err;
170c1e6e 2331 }
8df7a775 2332
8df7a775 2333 /*
2334 * Open socket.
2335 */
3ad9d396 2336 {
57356d63 2337 char addrbuf[100];
3ad9d396 2338 sk_getaddr(addr, addrbuf, 100);
57356d63 2339 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2340 }
51470298 2341 ssh->fn = &fn_table;
e8fa8f62 2342 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2343 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2344 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2345 ssh->s = NULL;
8df7a775 2346 return err;
67c4ba2e 2347 }
8df7a775 2348
8df7a775 2349 return NULL;
2350}
2351
2352/*
5471d09a 2353 * Throttle or unthrottle the SSH connection.
2354 */
51470298 2355static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2356{
51470298 2357 int old_count = ssh->v1_throttle_count;
2358 ssh->v1_throttle_count += adjust;
2359 assert(ssh->v1_throttle_count >= 0);
2360 if (ssh->v1_throttle_count && !old_count) {
2361 sk_set_frozen(ssh->s, 1);
2362 } else if (!ssh->v1_throttle_count && old_count) {
2363 sk_set_frozen(ssh->s, 0);
5471d09a 2364 }
2365}
2366
2367/*
2368 * Throttle or unthrottle _all_ local data streams (for when sends
2369 * on the SSH connection itself back up).
2370 */
51470298 2371static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2372{
2373 int i;
2374 struct ssh_channel *c;
2375
51470298 2376 if (enable == ssh->throttled_all)
5471d09a 2377 return;
51470298 2378 ssh->throttled_all = enable;
2379 ssh->overall_bufsize = bufsize;
2380 if (!ssh->channels)
5471d09a 2381 return;
51470298 2382 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2383 switch (c->type) {
2384 case CHAN_MAINSESSION:
2385 /*
2386 * This is treated separately, outside the switch.
2387 */
2388 break;
2389 case CHAN_X11:
2390 x11_override_throttle(c->u.x11.s, enable);
2391 break;
2392 case CHAN_AGENT:
2393 /* Agent channels require no buffer management. */
2394 break;
2395 case CHAN_SOCKDATA:
36f94d1f 2396 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2397 break;
2398 }
2399 }
2400}
2401
2402/*
51470298 2403 * Username and password input, abstracted off into routines
2404 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2405 */
0405e71f 2406
2407/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2408static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2409{
51470298 2410 ssh->userpass_input_buffer = buffer;
2411 ssh->userpass_input_buflen = buflen;
2412 ssh->userpass_input_bufpos = 0;
2413 ssh->userpass_input_echo = echo;
0405e71f 2414}
2415
2416/*
2417 * Process some terminal data in the course of username/password
2418 * input. Returns >0 for success (line of input returned in
2419 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2420 * for inconclusive (keep waiting for more input please).
2421 */
ae9ae89f 2422static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2423{
2424 char c;
2425
2426 while (inlen--) {
2427 switch (c = *in++) {
2428 case 10:
2429 case 13:
51470298 2430 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2431 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2432 return +1;
2433 break;
2434 case 8:
2435 case 127:
51470298 2436 if (ssh->userpass_input_bufpos > 0) {
2437 if (ssh->userpass_input_echo)
2438 c_write_str(ssh, "\b \b");
2439 ssh->userpass_input_bufpos--;
0405e71f 2440 }
2441 break;
2442 case 21:
2443 case 27:
51470298 2444 while (ssh->userpass_input_bufpos > 0) {
2445 if (ssh->userpass_input_echo)
2446 c_write_str(ssh, "\b \b");
2447 ssh->userpass_input_bufpos--;
0405e71f 2448 }
2449 break;
2450 case 3:
2451 case 4:
2452 return -1;
2453 break;
2454 default:
4692a14a 2455 /*
2456 * This simplistic check for printability is disabled
2457 * when we're doing password input, because some people
2458 * have control characters in their passwords.o
2459 */
2460 if ((!ssh->userpass_input_echo ||
2461 (c >= ' ' && c <= '~') ||
0405e71f 2462 ((unsigned char) c >= 160))
51470298 2463 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2464 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2465 if (ssh->userpass_input_echo)
2466 c_write(ssh, &c, 1);
0405e71f 2467 }
2468 break;
2469 }
2470 }
2471 return 0;
2472}
2473
f11d78f2 2474static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2475{
2476 Ssh ssh = (Ssh) sshv;
2477
2478 ssh->agent_response = reply;
2479 ssh->agent_response_len = replylen;
2480
2481 if (ssh->version == 1)
2482 do_ssh1_login(ssh, NULL, -1, 0);
2483 else
2484 do_ssh2_authconn(ssh, NULL, -1, 0);
2485}
2486
f11d78f2 2487static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2488{
2489 struct ssh_channel *c = (struct ssh_channel *)cv;
2490 Ssh ssh = c->ssh;
2491 void *sentreply = reply;
2492
2493 if (!sentreply) {
2494 /* Fake SSH_AGENT_FAILURE. */
2495 sentreply = "\0\0\0\1\5";
2496 replylen = 5;
2497 }
2498 if (ssh->version == 2) {
2499 ssh2_add_channel_data(c, sentreply, replylen);
2500 ssh2_try_send(c);
2501 } else {
2502 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2503 PKT_INT, c->remoteid,
9a10ecf4 2504 PKTT_DATA,
839f10db 2505 PKT_INT, replylen,
2506 PKT_DATA, sentreply, replylen,
9a10ecf4 2507 PKTT_OTHER,
839f10db 2508 PKT_END);
2509 }
2510 if (reply)
2511 sfree(reply);
2512}
2513
0405e71f 2514/*
fb09bf1c 2515 * Handle the key exchange and user authentication phases.
2516 */
51470298 2517static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
fb09bf1c 2518{
0016d70b 2519 int i, j, ret;
2520 unsigned char cookie[8], *ptr;
374330e2 2521 struct RSAKey servkey, hostkey;
2522 struct MD5Context md5c;
51470298 2523 struct do_ssh1_login_state {
2524 int len;
2525 unsigned char *rsabuf, *keystr1, *keystr2;
2526 unsigned long supported_ciphers_mask, supported_auths_mask;
2527 int tried_publickey, tried_agent;
2528 int tis_auth_refused, ccard_auth_refused;
2529 unsigned char session_id[16];
2530 int cipher_type;
2531 char username[100];
2532 void *publickey_blob;
2533 int publickey_bloblen;
2534 char password[100];
2535 char prompt[200];
2536 int pos;
2537 char c;
2538 int pwpkt_type;
2539 unsigned char request[5], *response, *p;
2540 int responselen;
2541 int keyi, nkeys;
2542 int authed;
2543 struct RSAKey key;
2544 Bignum challenge;
2545 char *commentp;
2546 int commentlen;
2547 };
2548 crState(do_ssh1_login_state);
2549
2550 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2551
32874aea 2552 if (!ispkt)
2553 crWaitUntil(ispkt);
374330e2 2554
51470298 2555 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2556 bombout(("Public key packet not received"));
7ffdbc1a 2557 crStop(0);
8d5de777 2558 }
374330e2 2559
c5e9c988 2560 logevent("Received public keys");
374330e2 2561
0016d70b 2562 ptr = ssh_pkt_getdata(ssh, 8);
2563 if (!ptr) {
2564 bombout(("SSH1 public key packet stopped before random cookie"));
2565 crStop(0);
2566 }
2567 memcpy(cookie, ptr, 8);
374330e2 2568
0016d70b 2569 if (!ssh1_pkt_getrsakey(ssh, &servkey, &s->keystr1) ||
2570 !ssh1_pkt_getrsakey(ssh, &hostkey, &s->keystr2)) {
ae0500e5 2571 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2572 crStop(0);
2573 }
374330e2 2574
c5e9c988 2575 /*
1c2a93c4 2576 * Log the host key fingerprint.
c5e9c988 2577 */
c5e9c988 2578 {
2579 char logmsg[80];
1c2a93c4 2580 logevent("Host key fingerprint is:");
c5e9c988 2581 strcpy(logmsg, " ");
32874aea 2582 hostkey.comment = NULL;
2583 rsa_fingerprint(logmsg + strlen(logmsg),
2584 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2585 logevent(logmsg);
2586 }
2587
0016d70b 2588 ssh->v1_remote_protoflags = ssh_pkt_getuint32(ssh);
2589 s->supported_ciphers_mask = ssh_pkt_getuint32(ssh);
2590 s->supported_auths_mask = ssh_pkt_getuint32(ssh);
bea1ef5f 2591
51470298 2592 ssh->v1_local_protoflags =
2593 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2594 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2595
c5e9c988 2596 MD5Init(&md5c);
51470298 2597 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2598 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2599 MD5Update(&md5c, cookie, 8);
51470298 2600 MD5Final(s->session_id, &md5c);
374330e2 2601
32874aea 2602 for (i = 0; i < 32; i++)
51470298 2603 ssh->session_key[i] = random_byte();
374330e2 2604
0016d70b 2605 /*
2606 * Verify that the `bits' and `bytes' parameters match.
2607 */
2608 if (hostkey.bits > hostkey.bytes * 8 ||
2609 servkey.bits > servkey.bytes * 8) {
2610 bombout(("SSH1 public keys were badly formatted"));
2611 crStop(0);
2612 }
2613
51470298 2614 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2615
3d88e64d 2616 s->rsabuf = snewn(s->len, unsigned char);
51470298 2617 if (!s->rsabuf)
374330e2 2618 fatalbox("Out of memory");
2619
89ee5268 2620 /*
2621 * Verify the host key.
2622 */
2623 {
32874aea 2624 /*
2625 * First format the key into a string.
2626 */
2627 int len = rsastr_len(&hostkey);
2628 char fingerprint[100];
3d88e64d 2629 char *keystr = snewn(len, char);
32874aea 2630 if (!keystr)
2631 fatalbox("Out of memory");
2632 rsastr_fmt(keystr, &hostkey);
2633 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2634 verify_ssh_host_key(ssh->frontend,
2635 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2636 fingerprint);
2637 sfree(keystr);
2638 }
2639
2640 for (i = 0; i < 32; i++) {
51470298 2641 s->rsabuf[i] = ssh->session_key[i];
374330e2 2642 if (i < 16)
51470298 2643 s->rsabuf[i] ^= s->session_id[i];
374330e2 2644 }
2645
2646 if (hostkey.bytes > servkey.bytes) {
0016d70b 2647 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2648 if (ret)
2649 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2650 } else {
0016d70b 2651 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2652 if (ret)
2653 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2654 }
2655 if (!ret) {
2656 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2657 crStop(0);
374330e2 2658 }
2659
c5e9c988 2660 logevent("Encrypted session key");
2661
ca20bfcf 2662 {
2663 int cipher_chosen = 0, warn = 0;
2664 char *cipher_string = NULL;
51470298 2665 int i;
ca20bfcf 2666 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2667 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2668 if (next_cipher == CIPHER_WARN) {
2669 /* If/when we choose a cipher, warn about it */
2670 warn = 1;
2671 } else if (next_cipher == CIPHER_AES) {
2672 /* XXX Probably don't need to mention this. */
2673 logevent("AES not supported in SSH1, skipping");
2674 } else {
2675 switch (next_cipher) {
51470298 2676 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2677 cipher_string = "3DES"; break;
51470298 2678 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2679 cipher_string = "Blowfish"; break;
51470298 2680 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2681 cipher_string = "single-DES"; break;
2682 }
51470298 2683 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2684 cipher_chosen = 1;
2685 }
2686 }
2687 if (!cipher_chosen) {
51470298 2688 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2689 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2690 "supporting 3DES encryption"));
2691 else
2692 /* shouldn't happen */
6b5cf8b4 2693 bombout(("No supported ciphers found"));
7ffdbc1a 2694 crStop(0);
a99a05c0 2695 }
ca20bfcf 2696
2697 /* Warn about chosen cipher if necessary. */
2698 if (warn)
a8327734 2699 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2700 }
ca20bfcf 2701
51470298 2702 switch (s->cipher_type) {
32874aea 2703 case SSH_CIPHER_3DES:
2704 logevent("Using 3DES encryption");
2705 break;
2706 case SSH_CIPHER_DES:
2707 logevent("Using single-DES encryption");
2708 break;
2709 case SSH_CIPHER_BLOWFISH:
2710 logevent("Using Blowfish encryption");
2711 break;
c5e9c988 2712 }
bea1ef5f 2713
51470298 2714 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2715 PKT_CHAR, s->cipher_type,
32874aea 2716 PKT_DATA, cookie, 8,
51470298 2717 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2718 PKT_DATA, s->rsabuf, s->len,
2719 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2720
c5e9c988 2721 logevent("Trying to enable encryption...");
374330e2 2722
51470298 2723 sfree(s->rsabuf);
374330e2 2724
51470298 2725 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2726 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2727 &ssh_3des);
371e569c 2728 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2729 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2730 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2731
0183b242 2732 ssh->crcda_ctx = crcda_make_context();
2733 logevent("Installing CRC compensation attack detector");
2734
679539d7 2735 if (servkey.modulus) {
2736 sfree(servkey.modulus);
2737 servkey.modulus = NULL;
2738 }
2739 if (servkey.exponent) {
2740 sfree(servkey.exponent);
2741 servkey.exponent = NULL;
2742 }
2743 if (hostkey.modulus) {
2744 sfree(hostkey.modulus);
2745 hostkey.modulus = NULL;
2746 }
2747 if (hostkey.exponent) {
2748 sfree(hostkey.exponent);
2749 hostkey.exponent = NULL;
2750 }
fb09bf1c 2751 crWaitUntil(ispkt);
374330e2 2752
51470298 2753 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2754 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2755 crStop(0);
8d5de777 2756 }
374330e2 2757
c5e9c988 2758 logevent("Successfully started encryption");
2759
374330e2 2760 fflush(stdout);
2761 {
86916870 2762 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 2763 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2764 if (!ssh_get_line("login as: ",
51470298 2765 s->username, sizeof(s->username), FALSE)) {
32874aea 2766 /*
2767 * get_line failed to get a username.
2768 * Terminate.
2769 */
2770 logevent("No username provided. Abandoning session.");
3bb2f322 2771 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2772 crStop(1);
32874aea 2773 }
2774 } else {
51470298 2775 int ret; /* need not be kept over crReturn */
2776 c_write_str(ssh, "login as: ");
2777 ssh->send_ok = 1;
0405e71f 2778
51470298 2779 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2780 do {
32874aea 2781 crWaitUntil(!ispkt);
51470298 2782 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2783 } while (ret == 0);
2784 if (ret < 0)
2785 cleanup_exit(0);
51470298 2786 c_write_str(ssh, "\r\n");
32874aea 2787 }
2788 } else {
86916870 2789 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2790 s->username[sizeof(s->username)-1] = '\0';
374330e2 2791 }
fb09bf1c 2792
51470298 2793 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2794 {
51470298 2795 char userlog[22 + sizeof(s->username)];
2796 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2797 logevent(userlog);
32874aea 2798 if (flags & FLAG_INTERACTIVE &&
2799 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2800 strcat(userlog, "\r\n");
51470298 2801 c_write_str(ssh, userlog);
3c8e959b 2802 }
c5e9c988 2803 }
374330e2 2804 }
2805
fb09bf1c 2806 crWaitUntil(ispkt);
374330e2 2807
51470298 2808 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2809 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2810 s->tried_publickey = s->tried_agent = 1;
0df73905 2811 } else {
51470298 2812 s->tried_publickey = s->tried_agent = 0;
0df73905 2813 }
51470298 2814 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2815 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2816 if (!filename_is_null(ssh->cfg.keyfile)) {
2817 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2818 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2819 s->publickey_blob = NULL;
396778f1 2820 } else
51470298 2821 s->publickey_blob = NULL;
7cca0d81 2822
51470298 2823 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2824 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2825
51470298 2826 if (agent_exists() && !s->tried_agent) {
32874aea 2827 /*
2828 * Attempt RSA authentication using Pageant.
2829 */
32874aea 2830 void *r;
2831
51470298 2832 s->authed = FALSE;
2833 s->tried_agent = 1;
32874aea 2834 logevent("Pageant is running. Requesting keys.");
2835
2836 /* Request the keys held by the agent. */
51470298 2837 PUT_32BIT(s->request, 1);
2838 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2839 if (!agent_query(s->request, 5, &r, &s->responselen,
2840 ssh_agent_callback, ssh)) {
2841 do {
2842 crReturn(0);
2843 if (ispkt) {
2844 bombout(("Unexpected data from server while waiting"
2845 " for agent response"));
2846 crStop(0);
2847 }
2848 } while (ispkt || inlen > 0);
2849 r = ssh->agent_response;
2850 s->responselen = ssh->agent_response_len;
2851 }
51470298 2852 s->response = (unsigned char *) r;
2853 if (s->response && s->responselen >= 5 &&
2854 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2855 s->p = s->response + 5;
2856 s->nkeys = GET_32BIT(s->p);
2857 s->p += 4;
32874aea 2858 {
2859 char buf[64];
51470298 2860 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2861 logevent(buf);
2862 }
51470298 2863 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2864 {
2865 char buf[64];
51470298 2866 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2867 logevent(buf);
2868 }
51470298 2869 if (s->publickey_blob &&
2870 !memcmp(s->p, s->publickey_blob,
2871 s->publickey_bloblen)) {
396778f1 2872 logevent("This key matches configured key file");
51470298 2873 s->tried_publickey = 1;
396778f1 2874 }
51470298 2875 s->p += 4;
0016d70b 2876 {
2877 int n, ok = FALSE;
2878 do { /* do while (0) to make breaking easy */
2879 n = ssh1_read_bignum
2880 (s->p, s->responselen-(s->p-s->response),
2881 &s->key.exponent);
2882 if (n < 0)
2883 break;
2884 s->p += n;
2885 n = ssh1_read_bignum
2886 (s->p, s->responselen-(s->p-s->response),
2887 &s->key.modulus);
2888 if (n < 0)
2889 break;
2890 s->p += n;
2891 if (s->responselen - (s->p-s->response) < 4)
2892 break;
2893 s->commentlen = GET_32BIT(s->p);
2894 s->p += 4;
2895 if (s->responselen - (s->p-s->response) <
2896 s->commentlen)
2897 break;
2898 s->commentp = (char *)s->p;
2899 s->p += s->commentlen;
2900 ok = TRUE;
2901 } while (0);
2902 if (!ok) {
2903 logevent("Pageant key list packet was truncated");
2904 break;
2905 }
2906 }
51470298 2907 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2908 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2909 crWaitUntil(ispkt);
51470298 2910 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2911 logevent("Key refused");
2912 continue;
2913 }
2914 logevent("Received RSA challenge");
0016d70b 2915 if ((s->challenge = ssh1_pkt_getmp(ssh)) == NULL) {
2916 bombout(("Server's RSA challenge was badly formatted"));
2917 crStop(0);
2918 }
2919
32874aea 2920 {
2921 char *agentreq, *q, *ret;
2d466ffd 2922 void *vret;
32874aea 2923 int len, retlen;
2924 len = 1 + 4; /* message type, bit count */
51470298 2925 len += ssh1_bignum_length(s->key.exponent);
2926 len += ssh1_bignum_length(s->key.modulus);
2927 len += ssh1_bignum_length(s->challenge);
32874aea 2928 len += 16; /* session id */
2929 len += 4; /* response format */
3d88e64d 2930 agentreq = snewn(4 + len, char);
32874aea 2931 PUT_32BIT(agentreq, len);
2932 q = agentreq + 4;
2933 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2934 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2935 q += 4;
51470298 2936 q += ssh1_write_bignum(q, s->key.exponent);
2937 q += ssh1_write_bignum(q, s->key.modulus);
2938 q += ssh1_write_bignum(q, s->challenge);
2939 memcpy(q, s->session_id, 16);
32874aea 2940 q += 16;
2941 PUT_32BIT(q, 1); /* response format */
839f10db 2942 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2943 ssh_agent_callback, ssh)) {
2944 sfree(agentreq);
2945 do {
2946 crReturn(0);
2947 if (ispkt) {
2948 bombout(("Unexpected data from server"
2949 " while waiting for agent"
2950 " response"));
2951 crStop(0);
2952 }
2953 } while (ispkt || inlen > 0);
2954 vret = ssh->agent_response;
2955 retlen = ssh->agent_response_len;
2956 } else
2957 sfree(agentreq);
2d466ffd 2958 ret = vret;
32874aea 2959 if (ret) {
2960 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2961 logevent("Sending Pageant's response");
51470298 2962 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2963 PKT_DATA, ret + 5, 16,
2964 PKT_END);
2965 sfree(ret);
2966 crWaitUntil(ispkt);
51470298 2967 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
32874aea 2968 logevent
2969 ("Pageant's response accepted");
2970 if (flags & FLAG_VERBOSE) {
51470298 2971 c_write_str(ssh, "Authenticated using"
2972 " RSA key \"");
2973 c_write(ssh, s->commentp,
2974 s->commentlen);
2975 c_write_str(ssh, "\" from agent\r\n");
32874aea 2976 }
51470298 2977 s->authed = TRUE;
32874aea 2978 } else
2979 logevent
2980 ("Pageant's response not accepted");
2981 } else {
2982 logevent
2983 ("Pageant failed to answer challenge");
2984 sfree(ret);
2985 }
2986 } else {
2987 logevent("No reply received from Pageant");
2988 }
2989 }
51470298 2990 freebn(s->key.exponent);
2991 freebn(s->key.modulus);
2992 freebn(s->challenge);
2993 if (s->authed)
32874aea 2994 break;
2995 }
29b1d0b3 2996 sfree(s->response);
32874aea 2997 }
51470298 2998 if (s->authed)
32874aea 2999 break;
3000 }
9a30e26b 3001 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3002 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3003
86916870 3004 if (ssh->cfg.try_tis_auth &&
51470298 3005 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3006 !s->tis_auth_refused) {
3007 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3008 logevent("Requested TIS authentication");
51470298 3009 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
32874aea 3010 crWaitUntil(ispkt);
51470298 3011 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3012 logevent("TIS authentication declined");
3013 if (flags & FLAG_INTERACTIVE)
51470298 3014 c_write_str(ssh, "TIS authentication refused.\r\n");
3015 s->tis_auth_refused = 1;
614a20a0 3016 continue;
32874aea 3017 } else {
0016d70b 3018 char *challenge;
3019 int challengelen;
3020
3021 ssh_pkt_getstring(ssh, &challenge, &challengelen);
3022 if (!challenge) {
3023 bombout(("TIS challenge packet was badly formed"));
3024 crStop(0);
3025 }
32874aea 3026 logevent("Received TIS challenge");
51470298 3027 if (challengelen > sizeof(s->prompt) - 1)
3028 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3029 memcpy(s->prompt, challenge, challengelen);
614a20a0 3030 /* Prompt heuristic comes from OpenSSH */
51470298 3031 strncpy(s->prompt + challengelen,
3032 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3033 "": "\r\nResponse: ",
51470298 3034 (sizeof s->prompt) - challengelen);
3035 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3036 }
3037 }
86916870 3038 if (ssh->cfg.try_tis_auth &&
51470298 3039 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3040 !s->ccard_auth_refused) {
3041 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3042 logevent("Requested CryptoCard authentication");
51470298 3043 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
32874aea 3044 crWaitUntil(ispkt);
51470298 3045 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3046 logevent("CryptoCard authentication declined");
51470298 3047 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3048 s->ccard_auth_refused = 1;
614a20a0 3049 continue;
32874aea 3050 } else {
0016d70b 3051 char *challenge;
3052 int challengelen;
3053
3054 ssh_pkt_getstring(ssh, &challenge, &challengelen);
3055 if (!challenge) {
3056 bombout(("CryptoCard challenge packet was badly formed"));
3057 crStop(0);
3058 }
32874aea 3059 logevent("Received CryptoCard challenge");
51470298 3060 if (challengelen > sizeof(s->prompt) - 1)
3061 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3062 memcpy(s->prompt, challenge, challengelen);
51470298 3063 strncpy(s->prompt + challengelen,
3064 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3065 "" : "\r\nResponse: ",
51470298 3066 sizeof(s->prompt) - challengelen);
3067 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3068 }
3069 }
51470298 3070 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3071 sprintf(s->prompt, "%.90s@%.90s's password: ",
3072 s->username, ssh->savedhost);
32874aea 3073 }
51470298 3074 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3075 char *comment = NULL;
231ee168 3076 int type;
3077 char msgbuf[256];
32874aea 3078 if (flags & FLAG_VERBOSE)
51470298 3079 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3080 logeventf(ssh, "Trying public key \"%s\"",
3081 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3082 type = key_type(&ssh->cfg.keyfile);
231ee168 3083 if (type != SSH_KEYTYPE_SSH1) {
3084 sprintf(msgbuf, "Key is of wrong type (%s)",
3085 key_type_to_str(type));
3086 logevent(msgbuf);
51470298 3087 c_write_str(ssh, msgbuf);
3088 c_write_str(ssh, "\r\n");
3089 s->tried_publickey = 1;
231ee168 3090 continue;
3091 }
9a30e26b 3092 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3093 if (flags & FLAG_VERBOSE)
51470298 3094 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3095 goto tryauth;
3096 }
51470298 3097 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3098 sfree(comment);
3099 }
a52f067e 3100
614a20a0 3101 /*
3102 * Show password prompt, having first obtained it via a TIS
3103 * or CryptoCard exchange if we're doing TIS or CryptoCard
3104 * authentication.
3105 */
fa17a66e 3106 if (ssh_get_line) {
51470298 3107 if (!ssh_get_line(s->prompt, s->password,
3108 sizeof(s->password), TRUE)) {
32874aea 3109 /*
3110 * get_line failed to get a password (for example
3111 * because one was supplied on the command line
3112 * which has already failed to work). Terminate.
3113 */
51470298 3114 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3115 PKT_STR, "No more passwords available to try",
3116 PKT_END);
247308b5 3117 logevent("Unable to authenticate");
a8327734 3118 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3119 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3120 crStop(1);
32874aea 3121 }
fb09bf1c 3122 } else {
614a20a0 3123 /* Prompt may have come from server. We've munged it a bit, so
3124 * we know it to be zero-terminated at least once. */
51470298 3125 int ret; /* need not be saved over crReturn */
3126 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3127 s->pos = 0;
0405e71f 3128
51470298 3129 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3130 do {
32874aea 3131 crWaitUntil(!ispkt);
51470298 3132 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3133 } while (ret == 0);
3134 if (ret < 0)
3135 cleanup_exit(0);
51470298 3136 c_write_str(ssh, "\r\n");
32874aea 3137 }
3138
3139 tryauth:
51470298 3140 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3141 /*
3142 * Try public key authentication with the specified
3143 * key file.
3144 */
51470298 3145 s->tried_publickey = 1;
3146
3147 {
222d54dc 3148 const char *error = NULL;
3149 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3150 &error);
51470298 3151 if (ret == 0) {
3152 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3153 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3154 c_write_str(ssh, " (");
3155 c_write_str(ssh, error);
3156 c_write_str(ssh, ").\r\n");
51470298 3157 continue; /* go and try password */
3158 }
3159 if (ret == -1) {
3160 c_write_str(ssh, "Wrong passphrase.\r\n");
3161 s->tried_publickey = 0;
3162 continue; /* try again */
3163 }
32874aea 3164 }
3165
3166 /*
3167 * Send a public key attempt.
3168 */
51470298 3169 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3170 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3171
3172 crWaitUntil(ispkt);
51470298 3173 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3174 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3175 continue; /* go and try password */
3176 }
51470298 3177 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3178 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3179 crStop(0);
32874aea 3180 }
32874aea 3181
51470298 3182 {
3183 int i;
3184 unsigned char buffer[32];
3185 Bignum challenge, response;
3186
0016d70b 3187 if ((challenge = ssh1_pkt_getmp(ssh)) == NULL) {
3188 bombout(("Server's RSA challenge was badly formatted"));
3189 crStop(0);
3190 }
51470298 3191 response = rsadecrypt(challenge, &s->key);
3192 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3193
51470298 3194 for (i = 0; i < 32; i++) {
3195 buffer[i] = bignum_byte(response, 31 - i);
3196 }
3197
3198 MD5Init(&md5c);
3199 MD5Update(&md5c, buffer, 32);
3200 MD5Update(&md5c, s->session_id, 16);
3201 MD5Final(buffer, &md5c);
32874aea 3202
51470298 3203 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3204 PKT_DATA, buffer, 16, PKT_END);
3205
3206 freebn(challenge);
3207 freebn(response);
3208 }
32874aea 3209
3210 crWaitUntil(ispkt);
51470298 3211 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3212 if (flags & FLAG_VERBOSE)
51470298 3213 c_write_str(ssh, "Failed to authenticate with"
3214 " our public key.\r\n");
32874aea 3215 continue; /* go and try password */
51470298 3216 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3217 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3218 crStop(0);
32874aea 3219 }
3220
3221 break; /* we're through! */
3222 } else {
51470298 3223 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3224 /*
3225 * Defence against traffic analysis: we send a
3226 * whole bunch of packets containing strings of
3227 * different lengths. One of these strings is the
3228 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3229 * The others are all random data in
3230 * SSH1_MSG_IGNORE packets. This way a passive
3231 * listener can't tell which is the password, and
3232 * hence can't deduce the password length.
3233 *
3234 * Anybody with a password length greater than 16
3235 * bytes is going to have enough entropy in their
3236 * password that a listener won't find it _that_
3237 * much help to know how long it is. So what we'll
3238 * do is:
3239 *
3240 * - if password length < 16, we send 15 packets
3241 * containing string lengths 1 through 15
3242 *
3243 * - otherwise, we let N be the nearest multiple
3244 * of 8 below the password length, and send 8
3245 * packets containing string lengths N through
3246 * N+7. This won't obscure the order of
3247 * magnitude of the password length, but it will
3248 * introduce a bit of extra uncertainty.
3249 *
3250 * A few servers (the old 1.2.18 through 1.2.22)
3251 * can't deal with SSH1_MSG_IGNORE. For these
3252 * servers, we need an alternative defence. We make
3253 * use of the fact that the password is interpreted
3254 * as a C string: so we can append a NUL, then some
3255 * random data.
bd358db1 3256 *
3257 * One server (a Cisco one) can deal with neither
3258 * SSH1_MSG_IGNORE _nor_ a padded password string.
3259 * For this server we are left with no defences
3260 * against password length sniffing.
32874aea 3261 */
51470298 3262 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3263 /*
3264 * The server can deal with SSH1_MSG_IGNORE, so
3265 * we can use the primary defence.
3266 */
32874aea 3267 int bottom, top, pwlen, i;
3268 char *randomstr;
3269
51470298 3270 pwlen = strlen(s->password);
32874aea 3271 if (pwlen < 16) {
3272 bottom = 0; /* zero length passwords are OK! :-) */
3273 top = 15;
3274 } else {
3275 bottom = pwlen & ~7;
3276 top = bottom + 7;
3277 }
3278
3279 assert(pwlen >= bottom && pwlen <= top);
3280
3d88e64d 3281 randomstr = snewn(top + 1, char);
32874aea 3282
3283 for (i = bottom; i <= top; i++) {
9a10ecf4 3284 if (i == pwlen) {
51470298 3285 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3286 PKTT_PASSWORD, PKT_STR, s->password,
3287 PKTT_OTHER, PKT_END);
3288 } else {
32874aea 3289 for (j = 0; j < i; j++) {
3290 do {
3291 randomstr[j] = random_byte();
3292 } while (randomstr[j] == '\0');
3293 }
3294 randomstr[i] = '\0';
51470298 3295 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3296 PKT_STR, randomstr, PKT_END);
3297 }
3298 }
bd358db1 3299 logevent("Sending password with camouflage packets");
51470298 3300 ssh_pkt_defersend(ssh);
679539d7 3301 sfree(randomstr);
bd358db1 3302 }
51470298 3303 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3304 /*
3305 * The server can't deal with SSH1_MSG_IGNORE
3306 * but can deal with padded passwords, so we
3307 * can use the secondary defence.
3308 */
bd358db1 3309 char string[64];
51470298 3310 char *ss;
bd358db1 3311 int len;
3312
51470298 3313 len = strlen(s->password);
bd358db1 3314 if (len < sizeof(string)) {
51470298 3315 ss = string;
3316 strcpy(string, s->password);
bd358db1 3317 len++; /* cover the zero byte */
3318 while (len < sizeof(string)) {
3319 string[len++] = (char) random_byte();
3320 }
3321 } else {
51470298 3322 ss = s->password;
bd358db1 3323 }
3324 logevent("Sending length-padded password");
9a10ecf4 3325 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3326 PKT_INT, len, PKT_DATA, ss, len,
3327 PKTT_OTHER, PKT_END);
bd358db1 3328 } else {
3329 /*
3330 * The server has _both_
3331 * BUG_CHOKES_ON_SSH1_IGNORE and
3332 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3333 * therefore nothing we can do.
3334 */
3335 int len;
51470298 3336 len = strlen(s->password);
bd358db1 3337 logevent("Sending unpadded password");
9a10ecf4 3338 send_packet(ssh, s->pwpkt_type,
3339 PKTT_PASSWORD, PKT_INT, len,
3340 PKT_DATA, s->password, len,
3341 PKTT_OTHER, PKT_END);
32874aea 3342 }
3343 } else {
9a10ecf4 3344 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3345 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3346 }
3347 }
c5e9c988 3348 logevent("Sent password");
51470298 3349 memset(s->password, 0, strlen(s->password));
fb09bf1c 3350 crWaitUntil(ispkt);
51470298 3351 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3352 if (flags & FLAG_VERBOSE)
51470298 3353 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3354 logevent("Authentication refused");
51470298 3355 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3356 bombout(("Strange packet received, type %d", ssh->pktin.type));
7ffdbc1a 3357 crStop(0);
374330e2 3358 }
3359 }
3360
c5e9c988 3361 logevent("Authentication successful");
3362
fb09bf1c 3363 crFinish(1);
3364}
3365
32874aea 3366void sshfwd_close(struct ssh_channel *c)
3367{
51470298 3368 Ssh ssh = c->ssh;
3369
36f94d1f 3370 if (ssh->state != SSH_STATE_SESSION) {
3371 assert(ssh->state == SSH_STATE_CLOSED);
3372 return;
3373 }
3374
80e48603 3375 if (c && !c->closes) {
4ed34d25 3376 /*
3377 * If the channel's remoteid is -1, we have sent
3378 * CHANNEL_OPEN for this channel, but it hasn't even been
3379 * acknowledged by the server. So we must set a close flag
3380 * on it now, and then when the server acks the channel
3381 * open, we can close it then.
3382 */
36cac739 3383 if (((int)c->remoteid) != -1) {
51470298 3384 if (ssh->version == 1) {
3385 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3386 PKT_END);
3387 } else {
51470298 3388 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3389 ssh2_pkt_adduint32(ssh, c->remoteid);
3390 ssh2_pkt_send(ssh);
4ed34d25 3391 }
32874aea 3392 }
0357890f 3393 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3394 if (c->type == CHAN_X11) {
3395 c->u.x11.s = NULL;
d74d141c 3396 logevent("Forwarded X11 connection terminated");
4ed34d25 3397 } else if (c->type == CHAN_SOCKDATA ||
3398 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3399 c->u.pfd.s = NULL;
3400 logevent("Forwarded port closed");
32874aea 3401 }
3402 }
3403}
3404
5471d09a 3405int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3406{
51470298 3407 Ssh ssh = c->ssh;
3408
36f94d1f 3409 if (ssh->state != SSH_STATE_SESSION) {
3410 assert(ssh->state == SSH_STATE_CLOSED);
3411 return 0;
3412 }
3413
51470298 3414 if (ssh->version == 1) {
3415 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3416 PKT_INT, c->remoteid,
9a10ecf4 3417 PKTT_DATA,
3418 PKT_INT, len, PKT_DATA, buf, len,
3419 PKTT_OTHER, PKT_END);
5471d09a 3420 /*
3421 * In SSH1 we can return 0 here - implying that forwarded
3422 * connections are never individually throttled - because
3423 * the only circumstance that can cause throttling will be
3424 * the whole SSH connection backing up, in which case
3425 * _everything_ will be throttled as a whole.
3426 */
3427 return 0;
783415f8 3428 } else {
32874aea 3429 ssh2_add_channel_data(c, buf, len);
5471d09a 3430 return ssh2_try_send(c);
3431 }
3432}
3433
3434void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3435{
51470298 3436 Ssh ssh = c->ssh;
3437
36f94d1f 3438 if (ssh->state != SSH_STATE_SESSION) {
3439 assert(ssh->state == SSH_STATE_CLOSED);
3440 return;
3441 }
3442
51470298 3443 if (ssh->version == 1) {
5471d09a 3444 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3445 c->v.v1.throttling = 0;
51470298 3446 ssh1_throttle(ssh, -1);
5471d09a 3447 }
3448 } else {
3449 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3450 }
9c964e85 3451}
3452
51470298 3453static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
32874aea 3454{
51470298 3455 crBegin(ssh->ssh1_protocol_crstate);
fb09bf1c 3456
3457 random_init();
3458
51470298 3459 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
fb09bf1c 3460 crReturnV;
85ee8208 3461 }
51470298 3462 if (ssh->state == SSH_STATE_CLOSED)
32874aea 3463 crReturnV;
fb09bf1c 3464
86916870 3465 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 3466 logevent("Requesting agent forwarding");
51470298 3467 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3468 do {
3469 crReturnV;
3470 } while (!ispkt);
51470298 3471 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3472 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3473 bombout(("Protocol confusion"));
7ffdbc1a 3474 crStopV;
51470298 3475 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3476 logevent("Agent forwarding refused");
3477 } else {
3478 logevent("Agent forwarding enabled");
51470298 3479 ssh->agentfwd_enabled = TRUE;
db7d555c 3480 }
dacbd0e8 3481 }
3482
86916870 3483 if (ssh->cfg.x11_forward) {
32874aea 3484 char proto[20], data[64];
3485 logevent("Requesting X11 forwarding");
302121de 3486 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 3487 data, sizeof(data), ssh->cfg.x11_auth);
3488 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 3489 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3490 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3491 PKT_STR, proto, PKT_STR, data,
86916870 3492 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 3493 PKT_END);
32874aea 3494 } else {
51470298 3495 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3496 PKT_STR, proto, PKT_STR, data, PKT_END);
3497 }
3498 do {
3499 crReturnV;
3500 } while (!ispkt);
51470298 3501 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3502 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3503 bombout(("Protocol confusion"));
7ffdbc1a 3504 crStopV;
51470298 3505 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3506 logevent("X11 forwarding refused");
3507 } else {
3508 logevent("X11 forwarding enabled");
51470298 3509 ssh->X11_fwd_enabled = TRUE;
9c964e85 3510 }
3511 }
3512
d74d141c 3513 {
9bf696b1 3514 char type;
d74d141c 3515 int n;
a4fc0d74 3516 int sport,dport,sserv,dserv;
6ee9b735 3517 char sports[256], dports[256], saddr[256], host[256];
d74d141c 3518
51470298 3519 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3520 /* Add port forwardings. */
86916870 3521 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 3522 while (*ssh->portfwd_strptr) {
3523 type = *ssh->portfwd_strptr++;
6ee9b735 3524 saddr[0] = '\0';
d74d141c 3525 n = 0;
6ee9b735 3526 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3527 if (*ssh->portfwd_strptr == ':') {
3528 /*
3529 * We've seen a colon in the middle of the
3530 * source port number. This means that
3531 * everything we've seen until now is the
3532 * source _address_, so we'll move it into
3533 * saddr and start sports from the beginning
3534 * again.
3535 */
3536 ssh->portfwd_strptr++;
3537 sports[n] = '\0';
3538 strcpy(saddr, sports);
3539 n = 0;
3540 }
3541 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3542 }
d74d141c 3543 sports[n] = 0;
820ebe3b 3544 if (type != 'D') {
3545 if (*ssh->portfwd_strptr == '\t')
3546 ssh->portfwd_strptr++;
3547 n = 0;
3548 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3549 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3550 }
3551 host[n] = 0;
3552 if (*ssh->portfwd_strptr == ':')
3553 ssh->portfwd_strptr++;
3554 n = 0;
3555 while (*ssh->portfwd_strptr) {
3556 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3557 }
3558 dports[n] = 0;
51470298 3559 ssh->portfwd_strptr++;
820ebe3b 3560 dport = atoi(dports);
3561 dserv = 0;
3562 if (dport == 0) {
3563 dserv = 1;
3564 dport = net_service_lookup(dports);
3565 if (!dport) {
3566 logeventf(ssh, "Service lookup failed for"
3567 " destination port \"%s\"", dports);
3568 }
a4fc0d74 3569 }
820ebe3b 3570 } else {
3571 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 3572 dport = dserv = -1;
7d5b0f4d 3573 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 3574 }
d74d141c 3575 sport = atoi(sports);
a4fc0d74 3576 sserv = 0;
3577 if (sport == 0) {
3578 sserv = 1;
68a49acb 3579 sport = net_service_lookup(sports);
3580 if (!sport) {
57356d63 3581 logeventf(ssh, "Service lookup failed for source"
3582 " port \"%s\"", sports);
a4fc0d74 3583 }
3584 }
d74d141c 3585 if (sport && dport) {
94ab1ddf 3586 /* Set up a description of the source port. */
3587 char *sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
3588 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3589 (int)(*saddr?1:0), ":",
3590 (int)(sserv ? strlen(sports) : 0), sports,
3591 sserv, "(", sport, sserv, ")");
d74d141c 3592 if (type == 'L') {
94ab1ddf 3593 /* Verbose description of the destination port */
3594 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3595 host,
3596 (int)(dserv ? strlen(dports) : 0), dports,
3597 dserv, "(", dport, dserv, ")");
3598 const char *err = pfd_addforward(host, dport,
3599 *saddr ? saddr : NULL,
3600 sport, ssh, &ssh->cfg);
3601 if (err) {
3602 logeventf(ssh, "Local port %s forward to %s"
3603 " failed: %s", sportdesc, dportdesc, err);
3604 } else {
3605 logeventf(ssh, "Local port %s forwarding to %s",
3606 sportdesc, dportdesc);
3607 }
3608 sfree(dportdesc);
820ebe3b 3609 } else if (type == 'D') {
94ab1ddf 3610 const char *err = pfd_addforward(NULL, -1,
3611 *saddr ? saddr : NULL,
3612 sport, ssh, &ssh->cfg);
3613 if (err) {
3614 logeventf(ssh, "Local port %s SOCKS dynamic forward"
3615 " setup failed: %s", sportdesc, err);
3616 } else {
3617 logeventf(ssh, "Local port %s doing SOCKS"
3618 " dynamic forwarding", sportdesc);
3619 }
d74d141c 3620 } else {
3621 struct ssh_rportfwd *pf;
3d88e64d 3622 pf = snew(struct ssh_rportfwd);
bc240b21 3623 strcpy(pf->dhost, host);
3624 pf->dport = dport;
0cd494d7 3625 if (*saddr) {
6ee9b735 3626 logeventf(ssh,
3627 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3628 saddr, sport);
3629 }
51470298 3630 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 3631 logeventf(ssh,
3632 "Duplicate remote port forwarding to %s:%d",
3633 host, dport);
bc240b21 3634 sfree(pf);
d74d141c 3635 } else {
57356d63 3636 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3637 " forward to %s:%.*s%.*s%d%.*s",
3638 (int)(sserv ? strlen(sports) : 0), sports,
3639 sserv, "(", sport, sserv, ")",
3640 host,
3641 (int)(dserv ? strlen(dports) : 0), dports,
3642 dserv, "(", dport, dserv, ")");
51470298 3643 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3644 PKT_INT, sport,
3645 PKT_STR, host,
3646 PKT_INT, dport,
3647 PKT_END);
9bf696b1 3648 do {
3649 crReturnV;
3650 } while (!ispkt);
51470298 3651 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3652 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3653 bombout(("Protocol confusion"));
7ffdbc1a 3654 crStopV;
51470298 3655 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3656 c_write_str(ssh, "Server refused port"
3657 " forwarding\r\n");
9bf696b1 3658 }
3659 logevent("Remote port forwarding enabled");
d74d141c 3660 }
3661 }
94ab1ddf 3662 sfree(sportdesc);
d74d141c 3663 }
3664 }
3665 }
3666
86916870 3667 if (!ssh->cfg.nopty) {
a5dd8467 3668 /* Unpick the terminal-speed string. */
3669 /* XXX perhaps we should allow no speeds to be sent. */
db219738 3670 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
3671 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 3672 /* Send the pty request. */
51470298 3673 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 3674 PKT_STR, ssh->cfg.termtype,
51470298 3675 PKT_INT, ssh->term_height,
3676 PKT_INT, ssh->term_width,
a5dd8467 3677 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 3678 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
3679 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 3680 PKT_CHAR, 0, PKT_END);
51470298 3681 ssh->state = SSH_STATE_INTERMED;
32874aea 3682 do {
3683 crReturnV;
3684 } while (!ispkt);
51470298 3685 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3686 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3687 bombout(("Protocol confusion"));
7ffdbc1a 3688 crStopV;
51470298 3689 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3690 c_write_str(ssh, "Server refused to allocate pty\r\n");
3691 ssh->editing = ssh->echoing = 1;
32874aea 3692 }
a5dd8467 3693 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 3694 ssh->ospeed, ssh->ispeed);
0965bee0 3695 } else {
51470298 3696 ssh->editing = ssh->echoing = 1;
374330e2 3697 }
3698
86916870 3699 if (ssh->cfg.compression) {
51470298 3700 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 3701 do {
3702 crReturnV;
3703 } while (!ispkt);
51470298 3704 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3705 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3706 bombout(("Protocol confusion"));
7ffdbc1a 3707 crStopV;
51470298 3708 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3709 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 3710 }
4ba9b64b 3711 logevent("Started compression");
51470298 3712 ssh->v1_compressing = TRUE;
5366aed8 3713 ssh->cs_comp_ctx = zlib_compress_init();
3714 logevent("Initialised zlib (RFC1950) compression");
3715 ssh->sc_comp_ctx = zlib_decompress_init();
3716 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 3717 }
3718
fd5e5847 3719 /*
3720 * Start the shell or command.
3721 *
3722 * Special case: if the first-choice command is an SSH2
3723 * subsystem (hence not usable here) and the second choice
3724 * exists, we fall straight back to that.
3725 */
3726 {
86916870 3727 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 3728
86916870 3729 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3730 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 3731 ssh->fallback_cmd = TRUE;
fd5e5847 3732 }
3733 if (*cmd)
51470298 3734 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 3735 else
51470298 3736 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 3737 logevent("Started session");
3738 }
374330e2 3739
51470298 3740 ssh->state = SSH_STATE_SESSION;
3741 if (ssh->size_needed)
3742 ssh_size(ssh, ssh->term_width, ssh->term_height);
3743 if (ssh->eof_needed)
3744 ssh_special(ssh, TS_EOF);
374330e2 3745
b9d7bcad 3746 if (ssh->ldisc)
3747 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 3748 ssh->send_ok = 1;
3749 ssh->channels = newtree234(ssh_channelcmp);
374330e2 3750 while (1) {
3751 crReturnV;
3752 if (ispkt) {
51470298 3753 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3754 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
0016d70b 3755 char *string;
3756 int stringlen, bufsize;
3757
3758 ssh_pkt_getstring(ssh, &string, &stringlen);
3759 if (string == NULL) {
3760 bombout(("Incoming terminal data packet was badly formed"));
3761 crStopV;
3762 }
3763
3764 bufsize =
51470298 3765 from_backend(ssh->frontend,
3766 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
0016d70b 3767 string, stringlen);
51470298 3768 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3769 ssh->v1_stdout_throttling = 1;
3770 ssh1_throttle(ssh, +1);
5471d09a 3771 }
51470298 3772 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3bb2f322 3773 ssh_closing((Plug)ssh, NULL, 0, 0);
c5e9c988 3774 logevent("Received disconnect request");
7ffdbc1a 3775 crStopV;
51470298 3776 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
32874aea 3777 /* Remote side is trying to open a channel to talk to our
3778 * X-Server. Give them back a local channel number. */
3779 struct ssh_channel *c;
0016d70b 3780 int remoteid = ssh_pkt_getuint32(ssh);
9c964e85 3781
3782 logevent("Received X11 connect request");
3783 /* Refuse if X11 forwarding is disabled. */
51470298 3784 if (!ssh->X11_fwd_enabled) {
3785 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3786 PKT_INT, remoteid, PKT_END);
9c964e85 3787 logevent("Rejected X11 connect request");
3788 } else {
3d88e64d 3789 c = snew(struct ssh_channel);
51470298 3790 c->ssh = ssh;
9c964e85 3791
86916870 3792 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
e8fa8f62 3793 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
0016d70b 3794 logevent("Opening X11 forward connection failed");
32874aea 3795 sfree(c);
51470298 3796 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3797 PKT_INT, remoteid, PKT_END);
9c964e85 3798 } else {
32874aea 3799 logevent
0016d70b 3800 ("Opening X11 forward connection succeeded");
3801 c->remoteid = remoteid;
51470298 3802 c->localid = alloc_channel_id(ssh);
32874aea 3803 c->closes = 0;
5471d09a 3804 c->v.v1.throttling = 0;
32874aea 3805 c->type = CHAN_X11; /* identify channel type */
51470298 3806 add234(ssh->channels, c);
3807 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
32874aea 3808 PKT_INT, c->remoteid, PKT_INT,
3809 c->localid, PKT_END);
3810 logevent("Opened X11 forward channel");
9c964e85 3811 }
3812 }
51470298 3813 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
32874aea 3814 /* Remote side is trying to open a channel to talk to our
3815 * agent. Give them back a local channel number. */
3816 struct ssh_channel *c;
0016d70b 3817 int remoteid = ssh_pkt_getuint32(ssh);
db7d555c 3818
3819 /* Refuse if agent forwarding is disabled. */
51470298 3820 if (!ssh->agentfwd_enabled) {
3821 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3822 PKT_INT, remoteid, PKT_END);
db7d555c 3823 } else {
3d88e64d 3824 c = snew(struct ssh_channel);
51470298 3825 c->ssh = ssh;
0016d70b 3826 c->remoteid = remoteid;
51470298 3827 c->localid = alloc_channel_id(ssh);
db7d555c 3828 c->closes = 0;
5471d09a 3829 c->v.v1.throttling = 0;
32874aea 3830 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3831 c->u.a.lensofar = 0;
51470298 3832 add234(ssh->channels, c);
3833 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
db7d555c 3834 PKT_INT, c->remoteid, PKT_INT, c->localid,
3835 PKT_END);
3836 }
51470298 3837 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
d74d141c 3838 /* Remote side is trying to open a channel to talk to a
3839 * forwarded port. Give them back a local channel number. */
3840 struct ssh_channel *c;
3841 struct ssh_rportfwd pf;
0016d70b 3842 int remoteid;
d74d141c 3843 int hostsize, port;
0016d70b 3844 char *host, buf[1024];
cbe2d68f 3845 const char *e;
3d88e64d 3846 c = snew(struct ssh_channel);
51470298 3847 c->ssh = ssh;
d74d141c 3848
0016d70b 3849 remoteid = ssh_pkt_getuint32(ssh);
3850 ssh_pkt_getstring(ssh, &host, &hostsize);
3851 port = ssh_pkt_getuint32(ssh);
d74d141c 3852
0016d70b 3853 if (hostsize >= lenof(pf.dhost))
3854 hostsize = lenof(pf.dhost)-1;
3855 memcpy(pf.dhost, host, hostsize);
3856 pf.dhost[hostsize] = '\0';
bc240b21 3857 pf.dport = port;
d74d141c 3858
51470298 3859 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
d74d141c 3860 sprintf(buf, "Rejected remote port open request for %s:%d",
0016d70b 3861 pf.dhost, port);
d74d141c 3862 logevent(buf);
51470298 3863 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3864 PKT_INT, remoteid, PKT_END);
d74d141c 3865 } else {
3866 sprintf(buf, "Received remote port open request for %s:%d",
0016d70b 3867 pf.dhost, port);
d74d141c 3868 logevent(buf);
0016d70b 3869 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3870 c, &ssh->cfg);
d74d141c 3871 if (e != NULL) {
3872 char buf[256];
3873 sprintf(buf, "Port open failed: %s", e);
3874 logevent(buf);
3875 sfree(c);
51470298 3876 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3877 PKT_INT, remoteid, PKT_END);
d74d141c 3878 } else {
0016d70b 3879 c->remoteid = remoteid;
51470298 3880 c->localid = alloc_channel_id(ssh);
d74d141c 3881 c->closes = 0;
5471d09a 3882 c->v.v1.throttling = 0;
d74d141c 3883 c->type = CHAN_SOCKDATA; /* identify channel type */
51470298 3884 add234(ssh->channels, c);
3885 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
d74d141c 3886 PKT_INT, c->remoteid, PKT_INT,
3887 c->localid, PKT_END);
3888 logevent("Forwarded port opened successfully");
3889 }
3890 }
3891
51470298 3892 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
0016d70b 3893 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3894 unsigned int localid = ssh_pkt_getuint32(ssh);
bc240b21 3895 struct ssh_channel *c;
3896
51470298 3897 c = find234(ssh->channels, &remoteid, ssh_channelfind);
bc240b21 3898 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3899 c->remoteid = localid;
3900 c->type = CHAN_SOCKDATA;
7781f316 3901 c->v.v1.throttling = 0;
bc240b21 3902 pfd_confirm(c->u.pfd.s);
3903 }
d74d141c 3904
4ed34d25 3905 if (c && c->closes) {
3906 /*
3907 * We have a pending close on this channel,
3908 * which we decided on before the server acked
3909 * the channel open. So now we know the
3910 * remoteid, we can close it again.
3911 */
51470298 3912 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3913 PKT_INT, c->remoteid, PKT_END);
4ed34d25 3914 }
3915
51470298 3916 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
0016d70b 3917 unsigned int remoteid = ssh_pkt_getuint32(ssh);
724cface 3918 struct ssh_channel *c;
3919
51470298 3920 c = find234(ssh->channels, &remoteid, ssh_channelfind);
724cface 3921 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3922 logevent("Forwarded connection refused by server");
3923 pfd_close(c->u.pfd.s);
51470298 3924 del234(ssh->channels, c);
724cface 3925 sfree(c);
3926 }
3927
51470298 3928 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3929 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3930 /* Remote side closes a channel. */
0016d70b 3931 unsigned i = ssh_pkt_getuint32(ssh);
32874aea 3932 struct ssh_channel *c;
51470298 3933 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 3934 if (c && ((int)c->remoteid) != -1) {
32874aea 3935 int closetype;
3936 closetype =
51470298 3937 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3938
783415f8 3939 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3940 logevent("Forwarded X11 connection terminated");
9c964e85 3941 assert(c->u.x11.s != NULL);
3942 x11_close(c->u.x11.s);
3943 c->u.x11.s = NULL;
3944 }
d74d141c 3945 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3946 logevent("Forwarded port closed");
3947 assert(c->u.pfd.s != NULL);
3948 pfd_close(c->u.pfd.s);
3949 c->u.pfd.s = NULL;
3950 }
0357890f 3951
3952 c->closes |= (closetype << 2); /* seen this message */
3953 if (!(c->closes & closetype)) {
51470298 3954 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
0357890f 3955 PKT_END);
3956 c->closes |= closetype; /* sent it too */
3957 }
3958
3959 if (c->closes == 15) {
51470298 3960 del234(ssh->channels, c);
32874aea 3961 sfree(c);
3962 }
d0d844c1 3963 } else {
6b5cf8b4 3964 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
51470298 3965 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
d0d844c1 3966 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3967 i));
7ffdbc1a 3968 crStopV;
32874aea 3969 }
51470298 3970 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
32874aea 3971 /* Data sent down one of our channels. */
0016d70b 3972 int i = ssh_pkt_getuint32(ssh);
3973 char *p;
3974 int len;
32874aea 3975 struct ssh_channel *c;
0016d70b 3976
3977 ssh_pkt_getstring(ssh, &p, &len);
3978
51470298 3979 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 3980 if (c) {
7ffdbc1a 3981 int bufsize = 0;
32874aea 3982 switch (c->type) {
3983 case CHAN_X11:
0016d70b 3984 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 3985 break;
d74d141c 3986 case CHAN_SOCKDATA:
0016d70b 3987 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 3988 break;
32874aea 3989 case CHAN_AGENT:
3990 /* Data for an agent message. Buffer it. */
3991 while (len > 0) {
3992 if (c->u.a.lensofar < 4) {
3993 int l = min(4 - c->u.a.lensofar, len);
3994 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3995 l);
3996 p += l;
3997 len -= l;
3998 c->u.a.lensofar += l;
3999 }
4000 if (c->u.a.lensofar == 4) {
4001 c->u.a.totallen =
4002 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 4003 c->u.a.message = snewn(c->u.a.totallen,
4004 unsigned char);
32874aea 4005 memcpy(c->u.a.message, c->u.a.msglen, 4);
4006 }
4007 if (c->u.a.lensofar >= 4 && len > 0) {
4008 int l =
4009 min(c->u.a.totallen - c->u.a.lensofar,
4010 len);
4011 memcpy(c->u.a.message + c->u.a.lensofar, p,
4012 l);
4013 p += l;
4014 len -= l;
4015 c->u.a.lensofar += l;
4016 }
4017 if (c->u.a.lensofar == c->u.a.totallen) {
839f10db 4018 void *reply;
32874aea 4019 int replylen;
839f10db 4020 if (agent_query(c->u.a.message,
4021 c->u.a.totallen,
4022 &reply, &replylen,
4023 ssh_agentf_callback, c))
4024 ssh_agentf_callback(c, reply, replylen);
32874aea 4025 sfree(c->u.a.message);
4026 c->u.a.lensofar = 0;
4027 }
4028 }
5471d09a 4029 bufsize = 0; /* agent channels never back up */
32874aea 4030 break;
4031 }
90347b95 4032 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 4033 c->v.v1.throttling = 1;
51470298 4034 ssh1_throttle(ssh, +1);
5471d09a 4035 }
32874aea 4036 }
51470298 4037 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 4038 /* may be from EXEC_SHELL on some servers */
51470298 4039 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 4040 /* may be from EXEC_SHELL on some servers
374330e2 4041 * if no pty is available or in other odd cases. Ignore */
51470298 4042 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 4043 char buf[100];
0016d70b 4044 ssh->exitcode = ssh_pkt_getuint32(ssh);
d8d6c7e5 4045 sprintf(buf, "Server sent command exit status %d",
51470298 4046 ssh->exitcode);
d8d6c7e5 4047 logevent(buf);
51470298 4048 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 4049 /*
4050 * In case `helpful' firewalls or proxies tack
4051 * extra human-readable text on the end of the
4052 * session which we might mistake for another
4053 * encrypted packet, we close the session once
4054 * we've sent EXIT_CONFIRMATION.
4055 */
3bb2f322 4056 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 4057 crStopV;
374330e2 4058 } else {
6b5cf8b4 4059 bombout(("Strange packet received: type %d", ssh->pktin.type));
7ffdbc1a 4060 crStopV;
374330e2 4061 }
4062 } else {
8df7a775 4063 while (inlen > 0) {
4064 int len = min(inlen, 512);
9a10ecf4 4065 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4066 PKT_INT, len, PKT_DATA, in, len,
4067 PKTT_OTHER, PKT_END);
8df7a775 4068 in += len;
4069 inlen -= len;
4070 }
374330e2 4071 }
4072 }
4073
4074 crFinishV;
4075}
4076
4077/*
e5574168 4078 * Utility routine for decoding comma-separated strings in KEXINIT.
4079 */
32874aea 4080static int in_commasep_string(char *needle, char *haystack, int haylen)
4081{
57356d63 4082 int needlen;
4083 if (!needle || !haystack) /* protect against null pointers */
4084 return 0;
4085 needlen = strlen(needle);
e5574168 4086 while (1) {
32874aea 4087 /*
4088 * Is it at the start of the string?
4089 */
4090 if (haylen >= needlen && /* haystack is long enough */
4091 !memcmp(needle, haystack, needlen) && /* initial match */
4092 (haylen == needlen || haystack[needlen] == ',')
4093 /* either , or EOS follows */
4094 )
4095 return 1;
4096 /*
4097 * If not, search for the next comma and resume after that.
4098 * If no comma found, terminate.
4099 */
4100 while (haylen > 0 && *haystack != ',')
4101 haylen--, haystack++;
4102 if (haylen == 0)
4103 return 0;
4104 haylen--, haystack++; /* skip over comma itself */
e5574168 4105 }
4106}
4107
4108/*
d39f364a 4109 * SSH2 key creation method.
4110 */
d8baa528 4111static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4112 unsigned char *sessid, char chr,
4113 unsigned char *keyspace)
32874aea 4114{
d39f364a 4115 SHA_State s;
4116 /* First 20 bytes. */
4117 SHA_Init(&s);
51470298 4118 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4119 sha_mpint(&s, K);
d39f364a 4120 SHA_Bytes(&s, H, 20);
4121 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4122 SHA_Bytes(&s, sessid, 20);
d39f364a 4123 SHA_Final(&s, keyspace);
4124 /* Next 20 bytes. */
4125 SHA_Init(&s);
51470298 4126 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4127 sha_mpint(&s, K);
d39f364a 4128 SHA_Bytes(&s, H, 20);
4129 SHA_Bytes(&s, keyspace, 20);
32874aea 4130 SHA_Final(&s, keyspace + 20);
d39f364a 4131}
4132
4133/*
7cca0d81 4134 * Handle the SSH2 transport layer.
e5574168 4135 */
51470298 4136static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
e5574168 4137{
51470298 4138 struct do_ssh2_transport_state {
4139 int nbits, pbits, warn;
4140 Bignum p, g, e, f, K;
4141 int kex_init_value, kex_reply_value;
4142 const struct ssh_mac **maclist;
4143 int nmacs;
4144 const struct ssh2_cipher *cscipher_tobe;
4145 const struct ssh2_cipher *sccipher_tobe;
4146 const struct ssh_mac *csmac_tobe;
4147 const struct ssh_mac *scmac_tobe;
4148 const struct ssh_compress *cscomp_tobe;
4149 const struct ssh_compress *sccomp_tobe;
4150 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4151 int hostkeylen, siglen;
4152 void *hkey; /* actual host key */
4153 unsigned char exchange_hash[20];
4154 int n_preferred_ciphers;
4155 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4156 const struct ssh_compress *preferred_comp;
4157 int first_kex;
4158 };
4159 crState(do_ssh2_transport_state);
4160
4161 crBegin(ssh->do_ssh2_transport_crstate);
4162
4163 s->cscipher_tobe = s->sccipher_tobe = NULL;
4164 s->csmac_tobe = s->scmac_tobe = NULL;
4165 s->cscomp_tobe = s->sccomp_tobe = NULL;
4166
7cca0d81 4167 random_init();
51470298 4168 s->first_kex = 1;
e5574168 4169
51470298 4170 {
4171 int i;
4172 /*
4173 * Set up the preferred ciphers. (NULL => warn below here)
4174 */
4175 s->n_preferred_ciphers = 0;
4176 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4177 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4178 case CIPHER_BLOWFISH:
4179 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4180 break;
4181 case CIPHER_DES:
86916870 4182 if (ssh->cfg.ssh2_des_cbc) {
51470298 4183 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4184 }
4185 break;
4186 case CIPHER_3DES:
4187 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4188 break;
4189 case CIPHER_AES:
4190 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4191 break;
4192 case CIPHER_WARN:
4193 /* Flag for later. Don't bother if it's the last in
4194 * the list. */
4195 if (i < CIPHER_MAX - 1) {
4196 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4197 }
4198 break;
ca20bfcf 4199 }
ca20bfcf 4200 }
5e8358ad 4201 }
ca20bfcf 4202
4203 /*
4204 * Set up preferred compression.
4205 */
86916870 4206 if (ssh->cfg.compression)
51470298 4207 s->preferred_comp = &ssh_zlib;
4ba9b64b 4208 else
51470298 4209 s->preferred_comp = &ssh_comp_none;
5e8358ad 4210
7591b9ff 4211 /*
4212 * Be prepared to work around the buggy MAC problem.
4213 */
51470298 4214 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4215 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 4216 else
51470298 4217 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 4218
32874aea 4219 begin_key_exchange:
51470298 4220 {
4221 int i, j, cipherstr_started;
4222
4223 /*
4224 * Construct and send our key exchange packet.
4225 */
4226 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
4227 for (i = 0; i < 16; i++)
4228 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
4229 /* List key exchange algorithms. */
4230 ssh2_pkt_addstring_start(ssh);
4231 for (i = 0; i < lenof(kex_algs); i++) {
4232 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4233 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4234 continue;
4235 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
4236 if (i < lenof(kex_algs) - 1)
4237 ssh2_pkt_addstring_str(ssh, ",");
32874aea 4238 }
51470298 4239 /* List server host key algorithms. */
4240 ssh2_pkt_addstring_start(ssh);
4241 for (i = 0; i < lenof(hostkey_algs); i++) {
4242 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
4243 if (i < lenof(hostkey_algs) - 1)
4244 ssh2_pkt_addstring_str(ssh, ",");
32874aea 4245 }
51470298 4246 /* List client->server encryption algorithms. */
4247 ssh2_pkt_addstring_start(ssh);
4248 cipherstr_started = 0;
4249 for (i = 0; i < s->n_preferred_ciphers; i++) {
4250 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4251 if (!c) continue; /* warning flag */
4252 for (j = 0; j < c->nciphers; j++) {
4253 if (cipherstr_started)
4254 ssh2_pkt_addstring_str(ssh, ",");
4255 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4256 cipherstr_started = 1;
4257 }
4258 }
4259 /* List server->client encryption algorithms. */
4260 ssh2_pkt_addstring_start(ssh);
4261 cipherstr_started = 0;
4262 for (i = 0; i < s->n_preferred_ciphers; i++) {
4263 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4264 if (!c) continue; /* warning flag */
4265 for (j = 0; j < c->nciphers; j++) {
4266 if (cipherstr_started)
4267 ssh2_pkt_addstring_str(ssh, ",");
4268 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4269 cipherstr_started = 1;
4270 }
4271 }
4272 /* List client->server MAC algorithms. */
4273 ssh2_pkt_addstring_start(ssh);
4274 for (i = 0; i < s->nmacs; i++) {
4275 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4276 if (i < s->nmacs - 1)
4277 ssh2_pkt_addstring_str(ssh, ",");
4278 }
4279 /* List server->client MAC algorithms. */
4280 ssh2_pkt_addstring_start(ssh);
4281 for (i = 0; i < s->nmacs; i++) {
4282 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4283 if (i < s->nmacs - 1)
4284 ssh2_pkt_addstring_str(ssh, ",");
4285 }
4286 /* List client->server compression algorithms. */
4287 ssh2_pkt_addstring_start(ssh);
f6e0abe2 4288 assert(lenof(compressions) > 1);
4289 ssh2_pkt_addstring_str(ssh, s->preferred_comp->name);
4290 for (i = 0; i < lenof(compressions); i++) {
4291 const struct ssh_compress *c = compressions[i];
4292 if (c != s->preferred_comp) {
51470298 4293 ssh2_pkt_addstring_str(ssh, ",");
f6e0abe2 4294 ssh2_pkt_addstring_str(ssh, c->name);
4295 }
51470298 4296 }
4297 /* List server->client compression algorithms. */
4298 ssh2_pkt_addstring_start(ssh);
f6e0abe2 4299 assert(lenof(compressions) > 1);
4300 ssh2_pkt_addstring_str(ssh, s->preferred_comp->name);
4301 for (i = 0; i < lenof(compressions); i++) {
4302 const struct ssh_compress *c = compressions[i];
4303 if (c != s->preferred_comp) {
51470298 4304 ssh2_pkt_addstring_str(ssh, ",");
f6e0abe2 4305 ssh2_pkt_addstring_str(ssh, c->name);
4306 }
51470298 4307 }
4308 /* List client->server languages. Empty list. */
4309 ssh2_pkt_addstring_start(ssh);
4310 /* List server->client languages. Empty list. */
4311 ssh2_pkt_addstring_start(ssh);
4312 /* First KEX packet does _not_ follow, because we're not that brave. */
4313 ssh2_pkt_addbool(ssh, FALSE);
4314 /* Reserved. */
4315 ssh2_pkt_adduint32(ssh, 0);
e5574168 4316 }
0db56f73 4317
51470298 4318 ssh->exhash = ssh->exhashbase;
4319 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
0db56f73 4320
51470298 4321 ssh2_pkt_send(ssh);
e5574168 4322
32874aea 4323 if (!ispkt)
4324 crWaitUntil(ispkt);
57356d63 4325 if (ssh->pktin.length > 5)
4326 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
e5574168 4327
4328 /*
4329 * Now examine the other side's KEXINIT to see what we're up
4330 * to.
4331 */
51470298 4332 {
4333 char *str;
4334 int i, j, len;
4335
4336 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4337 bombout(("expected key exchange packet from server"));
7ffdbc1a 4338 crStop(0);
32874aea 4339 }
51470298 4340 ssh->kex = NULL;
4341 ssh->hostkey = NULL;
4342 s->cscipher_tobe = NULL;
4343 s->sccipher_tobe = NULL;
4344 s->csmac_tobe = NULL;
4345 s->scmac_tobe = NULL;
4346 s->cscomp_tobe = NULL;
4347 s->sccomp_tobe = NULL;
4348 ssh->pktin.savedpos += 16; /* skip garbage cookie */
0016d70b 4349 ssh_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
51470298 4350 for (i = 0; i < lenof(kex_algs); i++) {
4351 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4352 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4353 continue;
4354 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4355 ssh->kex = kex_algs[i];
4356 break;
4357 }
32874aea 4358 }
0016d70b 4359 ssh_pkt_getstring(ssh, &str, &len); /* host key algorithms */
51470298 4360 for (i = 0; i < lenof(hostkey_algs); i++) {
4361 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4362 ssh->hostkey = hostkey_algs[i];
4363 break;
4364 }
4365 }
0016d70b 4366 ssh_pkt_getstring(ssh, &str, &len); /* client->server cipher */
51470298 4367 s->warn = 0;
4368 for (i = 0; i < s->n_preferred_ciphers; i++) {
4369 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4370 if (!c) {
4371 s->warn = 1;
4372 } else {
4373 for (j = 0; j < c->nciphers; j++) {
4374 if (in_commasep_string(c->list[j]->name, str, len)) {
4375 s->cscipher_tobe = c->list[j];
4376 break;
4377 }
ca20bfcf 4378 }
32874aea 4379 }
51470298 4380 if (s->cscipher_tobe) {
4381 if (s->warn)
a8327734 4382 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 4383 break;
4384 }
32874aea 4385 }
51470298 4386 if (!s->cscipher_tobe) {
6b5cf8b4 4387 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4388 str ? str : "(null)"));
7ffdbc1a 4389 crStop(0);
ca20bfcf 4390 }
0ef8f407 4391
0016d70b 4392 ssh_pkt_getstring(ssh, &str, &len); /* server->client cipher */
51470298 4393 s->warn = 0;
4394 for (i = 0; i < s->n_preferred_ciphers; i++) {
4395 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4396 if (!c) {
4397 s->warn = 1;
4398 } else {
4399 for (j = 0; j < c->nciphers; j++) {
4400 if (in_commasep_string(c->list[j]->name, str, len)) {
4401 s->sccipher_tobe = c->list[j];
4402 break;
4403 }
ca20bfcf 4404 }
32874aea 4405 }
51470298 4406 if (s->sccipher_tobe) {
4407 if (s->warn)
a8327734 4408 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 4409 break;
4410 }
32874aea 4411 }
51470298 4412 if (!s->sccipher_tobe) {
6b5cf8b4 4413 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4414 str ? str : "(null)"));
7ffdbc1a 4415 crStop(0);
ca20bfcf 4416 }
0ef8f407 4417
0016d70b 4418 ssh_pkt_getstring(ssh, &str, &len); /* client->server mac */
51470298 4419 for (i = 0; i < s->nmacs; i++) {
4420 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4421 s->csmac_tobe = s->maclist[i];
4422 break;
4423 }
32874aea 4424 }
0016d70b 4425 ssh_pkt_getstring(ssh, &str, &len); /* server->client mac */
51470298 4426 for (i = 0; i < s->nmacs; i++) {
4427 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4428 s->scmac_tobe = s->maclist[i];
4429 break;
4430 }
32874aea 4431 }
0016d70b 4432 ssh_pkt_getstring(ssh, &str, &len); /* client->server compression */
51470298 4433 for (i = 0; i < lenof(compressions) + 1; i++) {
4434 const struct ssh_compress *c =
4435 i == 0 ? s->preferred_comp : compressions[i - 1];
4436 if (in_commasep_string(c->name, str, len)) {
4437 s->cscomp_tobe = c;
4438 break;
4439 }
32874aea 4440 }
0016d70b 4441 ssh_pkt_getstring(ssh, &str, &len); /* server->client compression */
51470298 4442 for (i = 0; i < lenof(compressions) + 1; i++) {
4443 const struct ssh_compress *c =
4444 i == 0 ? s->preferred_comp : compressions[i - 1];
4445 if (in_commasep_string(c->name, str, len)) {
4446 s->sccomp_tobe = c;
4447 break;
4448 }
32874aea 4449 }
e5574168 4450 }
e5574168 4451
4452 /*
7bd5a860 4453 * Work out the number of bits of key we will need from the key
4454 * exchange. We start with the maximum key length of either
4455 * cipher...
4456 */
4457 {
32874aea 4458 int csbits, scbits;
7bd5a860 4459
51470298 4460 csbits = s->cscipher_tobe->keylen;
4461 scbits = s->sccipher_tobe->keylen;
4462 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 4463 }
4464 /* The keys only have 160-bit entropy, since they're based on
4465 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 4466 if (s->nbits > 160)
4467 s->nbits = 160;
7bd5a860 4468
4469 /*
a92dd380 4470 * If we're doing Diffie-Hellman group exchange, start by
4471 * requesting a group.
e5574168 4472 */
51470298 4473 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 4474 logevent("Doing Diffie-Hellman group exchange");
51470298 4475 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 4476 /*
4477 * Work out how big a DH group we will need to allow that
4478 * much data.
7bd5a860 4479 */
51470298 4480 s->pbits = 512 << ((s->nbits - 1) / 64);
4481 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4482 ssh2_pkt_adduint32(ssh, s->pbits);
4483 ssh2_pkt_send(ssh);
32874aea 4484
4485 crWaitUntil(ispkt);
51470298 4486 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 4487 bombout(("expected key exchange group packet from server"));
7ffdbc1a 4488 crStop(0);
32874aea 4489 }
51470298 4490 s->p = ssh2_pkt_getmp(ssh);
4491 s->g = ssh2_pkt_getmp(ssh);
27cd7fc2 4492 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 4493 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4494 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 4495 } else {
51470298 4496 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 4497 ssh->kex_ctx = dh_setup_group1();
51470298 4498 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4499 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 4500 }
e5574168 4501
a92dd380 4502 logevent("Doing Diffie-Hellman key exchange");
e5574168 4503 /*
a92dd380 4504 * Now generate and send e for Diffie-Hellman.
e5574168 4505 */
27cd7fc2 4506 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
51470298 4507 ssh2_pkt_init(ssh, s->kex_init_value);
4508 ssh2_pkt_addmp(ssh, s->e);
4509 ssh2_pkt_send(ssh);
e5574168 4510
4511 crWaitUntil(ispkt);
51470298 4512 if (ssh->pktin.type != s->kex_reply_value) {
6b5cf8b4 4513 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 4514 crStop(0);
7cca0d81 4515 }
0016d70b 4516 ssh_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
51470298 4517 s->f = ssh2_pkt_getmp(ssh);
0016d70b 4518 ssh_pkt_getstring(ssh, &s->sigdata, &s->siglen);
e5574168 4519
27cd7fc2 4520 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4521
51470298 4522 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4523 if (ssh->kex == &ssh_diffiehellman_gex) {
4524 sha_uint32(&ssh->exhash, s->pbits);
4525 sha_mpint(&ssh->exhash, s->p);
4526 sha_mpint(&ssh->exhash, s->g);
a92dd380 4527 }
51470298 4528 sha_mpint(&ssh->exhash, s->e);
4529 sha_mpint(&ssh->exhash, s->f);
4530 sha_mpint(&ssh->exhash, s->K);
4531 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4532
27cd7fc2 4533 dh_cleanup(ssh->kex_ctx);
fabd1805 4534 ssh->kex_ctx = NULL;
3709bfe9 4535
7cca0d81 4536#if 0
765c4200 4537 debug(("Exchange hash is:\n"));
51470298 4538 dmemdump(s->exchange_hash, 20);
7cca0d81 4539#endif
4540
51470298 4541 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4542 if (!s->hkey ||
4543 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 4544 (char *)s->exchange_hash, 20)) {
6b5cf8b4 4545 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 4546 crStop(0);
8d5de777 4547 }
e5574168 4548
4549 /*
7cca0d81 4550 * Authenticate remote host: verify host key. (We've already
4551 * checked the signature of the exchange hash.)
e5574168 4552 */
51470298 4553 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4554 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4555 verify_ssh_host_key(ssh->frontend,
4556 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4557 s->keystr, s->fingerprint);
4558 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4559 logevent("Host key fingerprint is:");
51470298 4560 logevent(s->fingerprint);
5e0d7cb8 4561 }
51470298 4562 sfree(s->fingerprint);
4563 sfree(s->keystr);
4564 ssh->hostkey->freekey(s->hkey);
d39f364a 4565
4566 /*
7cca0d81 4567 * Send SSH2_MSG_NEWKEYS.
d39f364a 4568 */
51470298 4569 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4570 ssh2_pkt_send(ssh);
d39f364a 4571
4572 /*
8406eaf9 4573 * Expect SSH2_MSG_NEWKEYS from server.
4574 */
4575 crWaitUntil(ispkt);
51470298 4576 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 4577 bombout(("expected new-keys packet from server"));
7ffdbc1a 4578 crStop(0);
8406eaf9 4579 }
4580
4581 /*
d39f364a 4582 * Create and initialise session keys.
4583 */
371e569c 4584 if (ssh->cs_cipher_ctx)
4585 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
51470298 4586 ssh->cscipher = s->cscipher_tobe;
371e569c 4587 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
e0e1a00d 4588
371e569c 4589 if (ssh->sc_cipher_ctx)
4590 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4591 ssh->sccipher = s->sccipher_tobe;
371e569c 4592 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4593
4594 if (ssh->cs_mac_ctx)
4595 ssh->csmac->free_context(ssh->cs_mac_ctx);
51470298 4596 ssh->csmac = s->csmac_tobe;
e0e1a00d 4597 ssh->cs_mac_ctx = ssh->csmac->make_context();
4598
4599 if (ssh->sc_mac_ctx)
4600 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4601 ssh->scmac = s->scmac_tobe;
e0e1a00d 4602 ssh->sc_mac_ctx = ssh->scmac->make_context();
4603
5366aed8 4604 if (ssh->cs_comp_ctx)
4605 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
51470298 4606 ssh->cscomp = s->cscomp_tobe;
5366aed8 4607 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4608
4609 if (ssh->sc_comp_ctx)
4610 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4611 ssh->sccomp = s->sccomp_tobe;
5366aed8 4612 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4613
d39f364a 4614 /*
5e0d7cb8 4615 * Set IVs after keys. Here we use the exchange hash from the
4616 * _first_ key exchange.
d39f364a 4617 */
51470298 4618 {
4619 unsigned char keyspace[40];
4620 if (s->first_kex)
4621 memcpy(ssh->v2_session_id, s->exchange_hash,
4622 sizeof(s->exchange_hash));
4623 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
371e569c 4624 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
51470298 4625 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4626 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4627 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
371e569c 4628 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
51470298 4629 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4630 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4631 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
e0e1a00d 4632 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
51470298 4633 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4634 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4635 }
57356d63 4636 logeventf(ssh, "Initialised %.200s client->server encryption",
4637 ssh->cscipher->text_name);
4638 logeventf(ssh, "Initialised %.200s server->client encryption",
4639 ssh->sccipher->text_name);
6c135243 4640 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4641 ssh->csmac->text_name);
4642 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4643 ssh->scmac->text_name);
57356d63 4644 if (ssh->cscomp->text_name)
4645 logeventf(ssh, "Initialised %s compression",
4646 ssh->cscomp->text_name);
4647 if (ssh->sccomp->text_name)
4648 logeventf(ssh, "Initialised %s decompression",
4649 ssh->sccomp->text_name);
679539d7 4650 freebn(s->f);
679539d7 4651 freebn(s->K);
b3949e7e 4652 if (ssh->kex == &ssh_diffiehellman_gex) {
4653 freebn(s->g);
4654 freebn(s->p);
4655 }
d39f364a 4656
033b4cef 4657 /*
0db56f73 4658 * If this is the first key exchange phase, we must pass the
4659 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4660 * wants to see it but because it will need time to initialise
4661 * itself before it sees an actual packet. In subsequent key
4662 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4663 * it would only confuse the layer above.
4664 */
51470298 4665 if (!s->first_kex) {
32874aea 4666 crReturn(0);
0db56f73 4667 }
51470298 4668 s->first_kex = 0;
0db56f73 4669
4670 /*
7cca0d81 4671 * Now we're encrypting. Begin returning 1 to the protocol main
4672 * function so that other things can run on top of the
4673 * transport. If we ever see a KEXINIT, we must go back to the
4674 * start.
033b4cef 4675 */
51470298 4676 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4677 crReturn(1);
e96adf72 4678 }
5e0d7cb8 4679 logevent("Server initiated key re-exchange");
7cca0d81 4680 goto begin_key_exchange;
e5574168 4681
4682 crFinish(1);
4683}
4684
7cca0d81 4685/*
783415f8 4686 * Add data to an SSH2 channel output buffer.
4687 */
32874aea 4688static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4689 int len)
4690{
5471d09a 4691 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4692}
4693
4694/*
4695 * Attempt to send data on an SSH2 channel.
4696 */
5471d09a 4697static int ssh2_try_send(struct ssh_channel *c)
32874aea 4698{
51470298 4699 Ssh ssh = c->ssh;
4700
5471d09a 4701 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4702 int len;
4703 void *data;
4704 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4705 if ((unsigned)len > c->v.v2.remwindow)
4706 len = c->v.v2.remwindow;
4707 if ((unsigned)len > c->v.v2.remmaxpkt)
4708 len = c->v.v2.remmaxpkt;
51470298 4709 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4710 ssh2_pkt_adduint32(ssh, c->remoteid);
9a10ecf4 4711 dont_log_data(ssh, PKTLOG_OMIT);
51470298 4712 ssh2_pkt_addstring_start(ssh);
4713 ssh2_pkt_addstring_data(ssh, data, len);
9a10ecf4 4714 end_log_omission(ssh);
51470298 4715 ssh2_pkt_send(ssh);
5471d09a 4716 bufchain_consume(&c->v.v2.outbuffer, len);
4717 c->v.v2.remwindow -= len;
4718 }
4719
4720 /*
4721 * After having sent as much data as we can, return the amount
4722 * still buffered.
4723 */
4724 return bufchain_size(&c->v.v2.outbuffer);
4725}
4726
4727/*
4728 * Potentially enlarge the window on an SSH2 channel.
4729 */
4730static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4731{
51470298 4732 Ssh ssh = c->ssh;
4733
6b69f42e 4734 /*
4735 * Never send WINDOW_ADJUST for a channel that the remote side
4736 * already thinks it's closed; there's no point, since it won't
4737 * be sending any more data anyway.
4738 */
4739 if (c->closes != 0)
4740 return;
4741
5471d09a 4742 if (newwin > c->v.v2.locwindow) {
51470298 4743 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4744 ssh2_pkt_adduint32(ssh, c->remoteid);
4745 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4746 ssh2_pkt_send(ssh);
5471d09a 4747 c->v.v2.locwindow = newwin;
783415f8 4748 }
4749}
4750
4751/*
7cca0d81 4752 * Handle the SSH2 userauth and connection layers.
4753 */
51470298 4754static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 4755{
51470298 4756 struct do_ssh2_authconn_state {
4757 enum {
4758 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4759 AUTH_PASSWORD,
4760 AUTH_KEYBOARD_INTERACTIVE
4761 } method;
4762 enum {
4763 AUTH_TYPE_NONE,
4764 AUTH_TYPE_PUBLICKEY,
4765 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4766 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4767 AUTH_TYPE_PASSWORD,
4768 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4769 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4770 } type;
4771 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4772 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4773 int kbd_inter_running;
4774 int we_are_in;
4775 int num_prompts, curr_prompt, echo;
4776 char username[100];
4777 int got_username;
85fdbe25 4778 char pwprompt[512];
51470298 4779 char password[100];
4780 void *publickey_blob;
4781 int publickey_bloblen;
4782 unsigned char request[5], *response, *p;
4783 int responselen;
4784 int keyi, nkeys;
4785 int authed;
4786 char *pkblob, *alg, *commentp;
4787 int pklen, alglen, commentlen;
4788 int siglen, retlen, len;
4789 char *q, *agentreq, *ret;
4790 int try_send;
73feed4f 4791 int num_env, env_left, env_ok;
51470298 4792 };
4793 crState(do_ssh2_authconn_state);
4794
4795 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 4796
7cca0d81 4797 /*
4798 * Request userauth protocol, and await a response to it.
4799 */
51470298 4800 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4801 ssh2_pkt_addstring(ssh, "ssh-userauth");
4802 ssh2_pkt_send(ssh);
7cca0d81 4803 crWaitUntilV(ispkt);
51470298 4804 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 4805 bombout(("Server refused user authentication protocol"));
7ffdbc1a 4806 crStopV;
8d5de777 4807 }
7cca0d81 4808
4809 /*
1408a877 4810 * We repeat this whole loop, including the username prompt,
4811 * until we manage a successful authentication. If the user
51470298 4812 * types the wrong _password_, they can be sent back to the
4813 * beginning to try another username, if this is configured on.
4814 * (If they specify a username in the config, they are never
4815 * asked, even if they do give a wrong password.)
1408a877 4816 *
4817 * I think this best serves the needs of
4818 *
4819 * - the people who have no configuration, no keys, and just
4820 * want to try repeated (username,password) pairs until they
4821 * type both correctly
4822 *
4823 * - people who have keys and configuration but occasionally
4824 * need to fall back to passwords
4825 *
4826 * - people with a key held in Pageant, who might not have
4827 * logged in to a particular machine before; so they want to
4828 * type a username, and then _either_ their key will be
4829 * accepted, _or_ they will type a password. If they mistype
4830 * the username they will want to be able to get back and
4831 * retype it!
7cca0d81 4832 */
51470298 4833 s->username[0] = '\0';
4834 s->got_username = FALSE;
1408a877 4835 do {
1408a877 4836 /*
4837 * Get a username.
4838 */
86916870 4839 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 4840 /*
4841 * We got a username last time round this loop, and
4842 * with change_username turned off we don't try to get
4843 * it again.
4844 */
86916870 4845 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 4846 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4847 if (!ssh_get_line("login as: ",
51470298 4848 s->username, sizeof(s->username), FALSE)) {
32874aea 4849 /*
4850 * get_line failed to get a username.
4851 * Terminate.
4852 */
4853 logevent("No username provided. Abandoning session.");
3bb2f322 4854 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 4855 crStopV;
32874aea 4856 }
4857 } else {
51470298 4858 int ret; /* need not be saved across crReturn */
4859 c_write_str(ssh, "login as: ");
4860 ssh->send_ok = 1;
4861 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 4862 do {
32874aea 4863 crWaitUntilV(!ispkt);
51470298 4864 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4865 } while (ret == 0);
4866 if (ret < 0)
4867 cleanup_exit(0);
4ca0c9d1 4868 c_write_str(ssh, "\r\n");
32874aea 4869 }
51470298 4870 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 4871 } else {
57356d63 4872 char *stuff;
86916870 4873 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 4874 s->username[sizeof(s->username)-1] = '\0';
65a22376 4875 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 4876 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 4877 c_write_str(ssh, stuff);
57356d63 4878 sfree(stuff);
7cca0d81 4879 }
4880 }
51470298 4881 s->got_username = TRUE;
7cca0d81 4882
65a22376 4883 /*
1408a877 4884 * Send an authentication request using method "none": (a)
4885 * just in case it succeeds, and (b) so that we know what
4886 * authentication methods we can usefully try next.
65a22376 4887 */
51470298 4888 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4889
4890 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4891 ssh2_pkt_addstring(ssh, s->username);
4892 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4893 ssh2_pkt_addstring(ssh, "none"); /* method */
4894 ssh2_pkt_send(ssh);
4895 s->type = AUTH_TYPE_NONE;
4896 s->gotit = FALSE;
4897 s->we_are_in = FALSE;
4898
4899 s->tried_pubkey_config = FALSE;
4900 s->tried_agent = FALSE;
4901 s->tried_keyb_inter = FALSE;
4902 s->kbd_inter_running = FALSE;
86916870 4903 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 4904 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 4905 int keytype;
6c6d9ed9 4906 logeventf(ssh, "Reading private key file \"%.150s\"",
4907 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 4908 keytype = key_type(&ssh->cfg.keyfile);
51470298 4909 if (keytype == SSH_KEYTYPE_SSH2) {
4910 s->publickey_blob =
9a30e26b 4911 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 4912 &s->publickey_bloblen, NULL);
51470298 4913 } else {
57356d63 4914 char *msgbuf;
c2ad7d0d 4915 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 4916 key_type_to_str(keytype));
57356d63 4917 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 4918 " (%s)\r\n",
4919 filename_to_str(&ssh->cfg.keyfile),
57356d63 4920 key_type_to_str(keytype));
51470298 4921 c_write_str(ssh, msgbuf);
57356d63 4922 sfree(msgbuf);
51470298 4923 s->publickey_blob = NULL;
231ee168 4924 }
396778f1 4925 } else
51470298 4926 s->publickey_blob = NULL;
65a22376 4927
1408a877 4928 while (1) {
4929 /*
4930 * Wait for the result of the last authentication request.
4931 */
51470298 4932 if (!s->gotit)
1408a877 4933 crWaitUntilV(ispkt);
51470298 4934 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4935 char *banner;
4936 int size;
4937 /*
4938 * Don't show the banner if we're operating in
4939 * non-verbose non-interactive mode. (It's probably
4940 * a script, which means nobody will read the
4941 * banner _anyway_, and moreover the printing of
4942 * the banner will screw up processing on the
4943 * output of (say) plink.)
4944 */
4945 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
0016d70b 4946 ssh_pkt_getstring(ssh, &banner, &size);
32874aea 4947 if (banner)
51470298 4948 c_write_untrusted(ssh, banner, size);
32874aea 4949 }
1408a877 4950 crWaitUntilV(ispkt);
4951 }
51470298 4952 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 4953 logevent("Access granted");
51470298 4954 s->we_are_in = TRUE;
1408a877 4955 break;
4956 }
65a22376 4957
51470298 4958 if (s->kbd_inter_running &&
4959 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 4960 /*
45068b27 4961 * This is either a further set-of-prompts packet
4962 * in keyboard-interactive authentication, or it's
4963 * the same one and we came back here with `gotit'
4964 * set. In the former case, we must reset the
4965 * curr_prompt variable.
b3186d64 4966 */
51470298 4967 if (!s->gotit)
4968 s->curr_prompt = 0;
4969 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 4970 bombout(("Strange packet received during authentication: type %d",
51470298 4971 ssh->pktin.type));
7ffdbc1a 4972 crStopV;
65a22376 4973 }
4974
51470298 4975 s->gotit = FALSE;
65a22376 4976
1408a877 4977 /*
4978 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4979 * we can look at the string in it and know what we can
4980 * helpfully try next.
4981 */
51470298 4982 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4983 char *methods;
4984 int methlen;
0016d70b 4985 ssh_pkt_getstring(ssh, &methods, &methlen);
51470298 4986 s->kbd_inter_running = FALSE;
4987 if (!ssh2_pkt_getbool(ssh)) {
1408a877 4988 /*
4989 * We have received an unequivocal Access
4990 * Denied. This can translate to a variety of
4991 * messages:
4992 *
4993 * - if we'd just tried "none" authentication,
4994 * it's not worth printing anything at all
4995 *
4996 * - if we'd just tried a public key _offer_,
4997 * the message should be "Server refused our
4998 * key" (or no message at all if the key
4999 * came from Pageant)
5000 *
5001 * - if we'd just tried anything else, the
5002 * message really should be "Access denied".
5003 *
5004 * Additionally, if we'd just tried password
5005 * authentication, we should break out of this
5006 * whole loop so as to go back to the username
5007 * prompt.
5008 */
51470298 5009 if (s->type == AUTH_TYPE_NONE) {
1408a877 5010 /* do nothing */
51470298 5011 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5012 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5013 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5014 c_write_str(ssh, "Server refused our key\r\n");
1408a877 5015 logevent("Server refused public key");
51470298 5016 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 5017 /* server declined keyboard-interactive; ignore */
1408a877 5018 } else {
51470298 5019 c_write_str(ssh, "Access denied\r\n");
1408a877 5020 logevent("Access denied");
51470298 5021 if (s->type == AUTH_TYPE_PASSWORD) {
5022 s->we_are_in = FALSE;
1408a877 5023 break;
5024 }
5025 }
5026 } else {
51470298 5027 c_write_str(ssh, "Further authentication required\r\n");
1408a877 5028 logevent("Further authentication required");
5029 }
65a22376 5030
51470298 5031 s->can_pubkey =
32874aea 5032 in_commasep_string("publickey", methods, methlen);
51470298 5033 s->can_passwd =
32874aea 5034 in_commasep_string("password", methods, methlen);
86916870 5035 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 5036 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 5037 }
65a22376 5038
51470298 5039 s->method = 0;
5040 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 5041 s->need_pw = FALSE;
65a22376 5042
0405e71f 5043 /*
5044 * Most password/passphrase prompts will be
5045 * non-echoing, so we set this to 0 by default.
5046 * Exception is that some keyboard-interactive prompts
5047 * can be echoing, in which case we'll set this to 1.
5048 */
51470298 5049 s->echo = 0;
0405e71f 5050
51470298 5051 if (!s->method && s->can_pubkey &&
5052 agent_exists() && !s->tried_agent) {
1983e559 5053 /*
5054 * Attempt public-key authentication using Pageant.
5055 */
1983e559 5056 void *r;
51470298 5057 s->authed = FALSE;
1983e559 5058
51470298 5059 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5060 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 5061
51470298 5062 s->tried_agent = TRUE;
1983e559 5063
5064 logevent("Pageant is running. Requesting keys.");
5065
5066 /* Request the keys held by the agent. */
51470298 5067 PUT_32BIT(s->request, 1);
5068 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 5069 if (!agent_query(s->request, 5, &r, &s->responselen,
5070 ssh_agent_callback, ssh)) {
5071 do {
5072 crReturnV;
5073 if (ispkt) {
5074 bombout(("Unexpected data from server while"
5075 " waiting for agent response"));
5076 crStopV;
5077 }
5078 } while (ispkt || inlen > 0);
5079 r = ssh->agent_response;
5080 s->responselen = ssh->agent_response_len;
5081 }
51470298 5082 s->response = (unsigned char *) r;
5083 if (s->response && s->responselen >= 5 &&
5084 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5085 s->p = s->response + 5;
5086 s->nkeys = GET_32BIT(s->p);
5087 s->p += 4;
32874aea 5088 {
5089 char buf[64];
51470298 5090 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 5091 logevent(buf);
5092 }
51470298 5093 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 5094 void *vret;
1983e559 5095
32874aea 5096 {
5097 char buf[64];
51470298 5098 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 5099 logevent(buf);
5100 }
51470298 5101 s->pklen = GET_32BIT(s->p);
5102 s->p += 4;
5103 if (s->publickey_blob &&
5104 s->pklen == s->publickey_bloblen &&
5105 !memcmp(s->p, s->publickey_blob,
5106 s->publickey_bloblen)) {
396778f1 5107 logevent("This key matches configured key file");
51470298 5108 s->tried_pubkey_config = 1;
396778f1 5109 }
d8baa528 5110 s->pkblob = (char *)s->p;
51470298 5111 s->p += s->pklen;
5112 s->alglen = GET_32BIT(s->pkblob);
5113 s->alg = s->pkblob + 4;
5114 s->commentlen = GET_32BIT(s->p);
5115 s->p += 4;
d8baa528 5116 s->commentp = (char *)s->p;
51470298 5117 s->p += s->commentlen;
5118 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5119 ssh2_pkt_addstring(ssh, s->username);
5120 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5121 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5122 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5123 ssh2_pkt_addstring_start(ssh);
5124 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
5125 ssh2_pkt_addstring_start(ssh);
5126 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
5127 ssh2_pkt_send(ssh);
1983e559 5128
5129 crWaitUntilV(ispkt);
51470298 5130 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 5131 logevent("Key refused");
5132 continue;
5133 }
5134
32874aea 5135 if (flags & FLAG_VERBOSE) {
51470298 5136 c_write_str(ssh, "Authenticating with "
5137 "public key \"");
5138 c_write(ssh, s->commentp, s->commentlen);
5139 c_write_str(ssh, "\" from agent\r\n");
32874aea 5140 }
1983e559 5141
5142 /*
5143 * Server is willing to accept the key.
5144 * Construct a SIGN_REQUEST.
5145 */
51470298 5146 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5147 ssh2_pkt_addstring(ssh, s->username);
5148 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5149 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5150 ssh2_pkt_addbool(ssh, TRUE);
5151 ssh2_pkt_addstring_start(ssh);
5152 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
5153 ssh2_pkt_addstring_start(ssh);
5154 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
5155
5156 s->siglen = ssh->pktout.length - 5 + 4 + 20;
dda87a28 5157 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5158 s->siglen -= 4;
51470298 5159 s->len = 1; /* message type */
5160 s->len += 4 + s->pklen; /* key blob */
5161 s->len += 4 + s->siglen; /* data to sign */
5162 s->len += 4; /* flags */
3d88e64d 5163 s->agentreq = snewn(4 + s->len, char);
51470298 5164 PUT_32BIT(s->agentreq, s->len);
5165 s->q = s->agentreq + 4;
5166 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5167 PUT_32BIT(s->q, s->pklen);
5168 s->q += 4;
5169 memcpy(s->q, s->pkblob, s->pklen);
5170 s->q += s->pklen;
5171 PUT_32BIT(s->q, s->siglen);
5172 s->q += 4;
1983e559 5173 /* Now the data to be signed... */
dda87a28 5174 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5175 PUT_32BIT(s->q, 20);
5176 s->q += 4;
5177 }
51470298 5178 memcpy(s->q, ssh->v2_session_id, 20);
5179 s->q += 20;
5180 memcpy(s->q, ssh->pktout.data + 5,
5181 ssh->pktout.length - 5);
5182 s->q += ssh->pktout.length - 5;
1983e559 5183 /* And finally the (zero) flags word. */
51470298 5184 PUT_32BIT(s->q, 0);
839f10db 5185 if (!agent_query(s->agentreq, s->len + 4,
5186 &vret, &s->retlen,
5187 ssh_agent_callback, ssh)) {
5188 do {
5189 crReturnV;
5190 if (ispkt) {
5191 bombout(("Unexpected data from server"
5192 " while waiting for agent"
5193 " response"));
5194 crStopV;
5195 }
5196 } while (ispkt || inlen > 0);
5197 vret = ssh->agent_response;
5198 s->retlen = ssh->agent_response_len;
5199 }
51470298 5200 s->ret = vret;
5201 sfree(s->agentreq);
5202 if (s->ret) {
5203 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 5204 logevent("Sending Pageant's response");
51470298 5205 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
5206 s->ret + 9,
5207 GET_32BIT(s->ret + 5));
5208 ssh2_pkt_send(ssh);
5209 s->authed = TRUE;
1983e559 5210 break;
5211 } else {
32874aea 5212 logevent
5213 ("Pageant failed to answer challenge");
51470298 5214 sfree(s->ret);
1983e559 5215 }
5216 }
5217 }
51470298 5218 if (s->authed)
1983e559 5219 continue;
5220 }
29b1d0b3 5221 sfree(s->response);
1983e559 5222 }
5223
51470298 5224 if (!s->method && s->can_pubkey && s->publickey_blob
5225 && !s->tried_pubkey_config) {
1408a877 5226 unsigned char *pub_blob;
5227 char *algorithm, *comment;
5228 int pub_blob_len;
65a22376 5229
51470298 5230 s->tried_pubkey_config = TRUE;
65a22376 5231
51470298 5232 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5233 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 5234
65a22376 5235 /*
1408a877 5236 * Try the public key supplied in the configuration.
5237 *
5238 * First, offer the public blob to see if the server is
5239 * willing to accept it.
65a22376 5240 */
d8baa528 5241 pub_blob =
9a30e26b 5242 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 5243 &algorithm,
222d54dc 5244 &pub_blob_len,
5245 NULL);
1408a877 5246 if (pub_blob) {
51470298 5247 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5248 ssh2_pkt_addstring(ssh, s->username);
5249 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5250 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5251 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5252 ssh2_pkt_addstring(ssh, algorithm);
5253 ssh2_pkt_addstring_start(ssh);
d8baa528 5254 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
5255 pub_blob_len);
51470298 5256 ssh2_pkt_send(ssh);
32874aea 5257 logevent("Offered public key"); /* FIXME */
1408a877 5258
5259 crWaitUntilV(ispkt);
51470298 5260 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
5261 s->gotit = TRUE;
5262 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 5263 continue; /* key refused; give up on it */
1408a877 5264 }
65a22376 5265
1408a877 5266 logevent("Offer of public key accepted");
65a22376 5267 /*
1408a877 5268 * Actually attempt a serious authentication using
5269 * the key.
65a22376 5270 */
9a30e26b 5271 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 5272 sprintf(s->pwprompt,
32874aea 5273 "Passphrase for key \"%.100s\": ",
5274 comment);
51470298 5275 s->need_pw = TRUE;
1408a877 5276 } else {
51470298 5277 s->need_pw = FALSE;
1408a877 5278 }
4e520718 5279 if (flags & FLAG_VERBOSE) {
5280 c_write_str(ssh, "Authenticating with public key \"");
5281 c_write_str(ssh, comment);
5282 c_write_str(ssh, "\"\r\n");
5283 }
51470298 5284 s->method = AUTH_PUBLICKEY_FILE;
65a22376 5285 }
1408a877 5286 }
5287
51470298 5288 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
5289 s->method = AUTH_KEYBOARD_INTERACTIVE;
5290 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5291 s->tried_keyb_inter = TRUE;
af659722 5292
51470298 5293 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5294 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 5295
51470298 5296 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5297 ssh2_pkt_addstring(ssh, s->username);
5298 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5299 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
5300 ssh2_pkt_addstring(ssh, ""); /* lang */
5301 ssh2_pkt_addstring(ssh, "");
5302 ssh2_pkt_send(ssh);
af659722 5303
5304 crWaitUntilV(ispkt);
51470298 5305 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
5306 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
5307 s->gotit = TRUE;
af659722 5308 logevent("Keyboard-interactive authentication refused");
51470298 5309 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 5310 continue;
5311 }
5312
51470298 5313 s->kbd_inter_running = TRUE;
5314 s->curr_prompt = 0;
af659722 5315 }
5316
51470298 5317 if (s->kbd_inter_running) {
5318 s->method = AUTH_KEYBOARD_INTERACTIVE;
5319 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5320 s->tried_keyb_inter = TRUE;
af659722 5321
51470298 5322 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5323 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 5324
51470298 5325 if (s->curr_prompt == 0) {
45068b27 5326 /*
5327 * We've got a fresh USERAUTH_INFO_REQUEST.
5328 * Display header data, and start going through
5329 * the prompts.
5330 */
5331 char *name, *inst, *lang;
5332 int name_len, inst_len, lang_len;
5333
0016d70b 5334 ssh_pkt_getstring(ssh, &name, &name_len);
5335 ssh_pkt_getstring(ssh, &inst, &inst_len);
5336 ssh_pkt_getstring(ssh, &lang, &lang_len);
45068b27 5337 if (name_len > 0) {
51470298 5338 c_write_untrusted(ssh, name, name_len);
5339 c_write_str(ssh, "\r\n");
45068b27 5340 }
5341 if (inst_len > 0) {
51470298 5342 c_write_untrusted(ssh, inst, inst_len);
5343 c_write_str(ssh, "\r\n");
45068b27 5344 }
0016d70b 5345 s->num_prompts = ssh_pkt_getuint32(ssh);
45068b27 5346 }
af659722 5347
45068b27 5348 /*
5349 * If there are prompts remaining in the packet,
5350 * display one and get a response.
5351 */
51470298 5352 if (s->curr_prompt < s->num_prompts) {
45068b27 5353 char *prompt;
5354 int prompt_len;
af659722 5355
0016d70b 5356 ssh_pkt_getstring(ssh, &prompt, &prompt_len);
45068b27 5357 if (prompt_len > 0) {
85fdbe25 5358 static const char trunc[] = "<prompt truncated>: ";
5359 static const int prlen = sizeof(s->pwprompt) -
5360 lenof(trunc);
5361 if (prompt_len > prlen) {
5362 memcpy(s->pwprompt, prompt, prlen);
5363 strcpy(s->pwprompt + prlen, trunc);
5364 } else {
5365 memcpy(s->pwprompt, prompt, prompt_len);
5366 s->pwprompt[prompt_len] = '\0';
5367 }
45068b27 5368 } else {
51470298 5369 strcpy(s->pwprompt,
45068b27 5370 "<server failed to send prompt>: ");
5371 }
51470298 5372 s->echo = ssh2_pkt_getbool(ssh);
5373 s->need_pw = TRUE;
45068b27 5374 } else
51470298 5375 s->need_pw = FALSE;
af659722 5376 }
5377
51470298 5378 if (!s->method && s->can_passwd) {
5379 s->method = AUTH_PASSWORD;
5380 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5381 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5382 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5383 ssh->savedhost);
5384 s->need_pw = TRUE;
1408a877 5385 }
5386
51470298 5387 if (s->need_pw) {
fa17a66e 5388 if (ssh_get_line) {
51470298 5389 if (!ssh_get_line(s->pwprompt, s->password,
5390 sizeof(s->password), TRUE)) {
1408a877 5391 /*
fa17a66e 5392 * get_line failed to get a password (for
5393 * example because one was supplied on the
5394 * command line which has already failed to
5395 * work). Terminate.
1408a877 5396 */
51470298 5397 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5398 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5399 ssh2_pkt_addstring(ssh, "No more passwords available"
5400 " to try");
5401 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5402 ssh2_pkt_send(ssh);
247308b5 5403 logevent("Unable to authenticate");
a8327734 5404 connection_fatal(ssh->frontend,
5405 "Unable to authenticate");
3bb2f322 5406 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5407 crStopV;
1408a877 5408 }
5409 } else {
51470298 5410 int ret; /* need not be saved across crReturn */
5411 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5412 ssh->send_ok = 1;
1408a877 5413
51470298 5414 setup_userpass_input(ssh, s->password,
5415 sizeof(s->password), s->echo);
0405e71f 5416 do {
1408a877 5417 crWaitUntilV(!ispkt);
51470298 5418 ret = process_userpass_input(ssh, in, inlen);
0405e71f 5419 } while (ret == 0);
5420 if (ret < 0)
5421 cleanup_exit(0);
51470298 5422 c_write_str(ssh, "\r\n");
65a22376 5423 }
65a22376 5424 }
65a22376 5425
51470298 5426 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 5427 /*
5428 * We have our passphrase. Now try the actual authentication.
5429 */
5430 struct ssh2_userkey *key;
222d54dc 5431 const char *error = NULL;
65a22376 5432
222d54dc 5433 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5434 &error);
1408a877 5435 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5436 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 5437 c_write_str(ssh, "Wrong passphrase\r\n");
5438 s->tried_pubkey_config = FALSE;
1408a877 5439 } else {
222d54dc 5440 c_write_str(ssh, "Unable to load private key (");
5441 c_write_str(ssh, error);
5442 c_write_str(ssh, ")\r\n");
51470298 5443 s->tried_pubkey_config = TRUE;
1408a877 5444 }
5445 /* Send a spurious AUTH_NONE to return to the top. */
51470298 5446 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5447 ssh2_pkt_addstring(ssh, s->username);
5448 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5449 ssh2_pkt_addstring(ssh, "none"); /* method */
5450 ssh2_pkt_send(ssh);
5451 s->type = AUTH_TYPE_NONE;
1408a877 5452 } else {
1dd353b5 5453 unsigned char *pkblob, *sigblob, *sigdata;
5454 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 5455 int p;
65a22376 5456
1408a877 5457 /*
5458 * We have loaded the private key and the server
5459 * has announced that it's willing to accept it.
5460 * Hallelujah. Generate a signature and send it.
5461 */
51470298 5462 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5463 ssh2_pkt_addstring(ssh, s->username);
5464 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5465 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5466 ssh2_pkt_addbool(ssh, TRUE);
5467 ssh2_pkt_addstring(ssh, key->alg->name);
1dd353b5 5468 pkblob = key->alg->public_blob(key->data, &pkblob_len);
51470298 5469 ssh2_pkt_addstring_start(ssh);
d8baa528 5470 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
1408a877 5471
5472 /*
5473 * The data to be signed is:
5474 *
5475 * string session-id
5476 *
5477 * followed by everything so far placed in the
5478 * outgoing packet.
5479 */
51470298 5480 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
dda87a28 5481 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5482 sigdata_len -= 4;
92d60585 5483 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 5484 p = 0;
5485 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5486 PUT_32BIT(sigdata+p, 20);
5487 p += 4;
5488 }
5489 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5490 memcpy(sigdata+p, ssh->pktout.data + 5,
51470298 5491 ssh->pktout.length - 5);
dda87a28 5492 p += ssh->pktout.length - 5;
5493 assert(p == sigdata_len);
d8baa528 5494 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 5495 sigdata_len, &sigblob_len);
51470298 5496 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
1dd353b5 5497 sigblob, sigblob_len);
5498 sfree(pkblob);
5499 sfree(sigblob);
1408a877 5500 sfree(sigdata);
5501
51470298 5502 ssh2_pkt_send(ssh);
5503 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 5504 key->alg->freekey(key->data);
1408a877 5505 }
51470298 5506 } else if (s->method == AUTH_PASSWORD) {
65a22376 5507 /*
1408a877 5508 * We send the password packet lumped tightly together with
5509 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5510 * string long enough to make the total length of the two
5511 * packets constant. This should ensure that a passive
5512 * listener doing traffic analyis can't work out the length
5513 * of the password.
5514 *
5515 * For this to work, we need an assumption about the
5516 * maximum length of the password packet. I think 256 is
5517 * pretty conservative. Anyone using a password longer than
5518 * that probably doesn't have much to worry about from
5519 * people who find out how long their password is!
65a22376 5520 */
51470298 5521 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5522 ssh2_pkt_addstring(ssh, s->username);
5523 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5524 ssh2_pkt_addstring(ssh, "password");
5525 ssh2_pkt_addbool(ssh, FALSE);
9a10ecf4 5526 dont_log_password(ssh, PKTLOG_BLANK);
51470298 5527 ssh2_pkt_addstring(ssh, s->password);
1409c1b3 5528 memset(s->password, 0, sizeof(s->password));
9a10ecf4 5529 end_log_omission(ssh);
51470298 5530 ssh2_pkt_defer(ssh);
65a22376 5531 /*
1408a877 5532 * We'll include a string that's an exact multiple of the
5533 * cipher block size. If the cipher is NULL for some
5534 * reason, we don't do this trick at all because we gain
5535 * nothing by it.
65a22376 5536 */
51470298 5537 if (ssh->cscipher) {
32874aea 5538 int stringlen, i;
5539
51470298 5540 stringlen = (256 - ssh->deferred_len);
5541 stringlen += ssh->cscipher->blksize - 1;
5542 stringlen -= (stringlen % ssh->cscipher->blksize);
5543 if (ssh->cscomp) {
32874aea 5544 /*
5545 * Temporarily disable actual compression,
5546 * so we can guarantee to get this string
5547 * exactly the length we want it. The
5548 * compression-disabling routine should
5549 * return an integer indicating how many
5550 * bytes we should adjust our string length
5551 * by.
5552 */
5366aed8 5553 stringlen -=
5554 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 5555 }
51470298 5556 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5557 ssh2_pkt_addstring_start(ssh);
6e9e9520 5558 for (i = 0; i < stringlen; i++) {
32874aea 5559 char c = (char) random_byte();
51470298 5560 ssh2_pkt_addstring_data(ssh, &c, 1);
65a22376 5561 }
51470298 5562 ssh2_pkt_defer(ssh);
65a22376 5563 }
51470298 5564 ssh_pkt_defersend(ssh);
0d43337a 5565 logevent("Sent password");
51470298 5566 s->type = AUTH_TYPE_PASSWORD;
5567 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5568 if (s->curr_prompt == 0) {
5569 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5570 ssh2_pkt_adduint32(ssh, s->num_prompts);
45068b27 5571 }
51470298 5572 if (s->need_pw) { /* only add pw if we just got one! */
9a10ecf4 5573 dont_log_password(ssh, PKTLOG_BLANK);
51470298 5574 ssh2_pkt_addstring(ssh, s->password);
5575 memset(s->password, 0, sizeof(s->password));
9a10ecf4 5576 end_log_omission(ssh);
51470298 5577 s->curr_prompt++;
45068b27 5578 }
51470298 5579 if (s->curr_prompt >= s->num_prompts) {
5580 ssh2_pkt_send(ssh);
45068b27 5581 } else {
5582 /*
5583 * If there are prompts remaining, we set
5584 * `gotit' so that we won't attempt to get
5585 * another packet. Then we go back round the
5586 * loop and will end up retrieving another
5587 * prompt out of the existing packet. Funky or
5588 * what?
5589 */
51470298 5590 s->gotit = TRUE;
45068b27 5591 }
51470298 5592 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 5593 } else {
51470298 5594 c_write_str(ssh, "No supported authentication methods"
5595 " left to try!\r\n");
5596 logevent("No supported authentications offered."
5597 " Disconnecting");
5598 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5599 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5600 ssh2_pkt_addstring(ssh, "No supported authentication"
5601 " methods available");
5602 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5603 ssh2_pkt_send(ssh);
3bb2f322 5604 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5605 crStopV;
65a22376 5606 }
65a22376 5607 }
51470298 5608 } while (!s->we_are_in);
7cca0d81 5609
5610 /*
5611 * Now we're authenticated for the connection protocol. The
5612 * connection protocol will automatically have started at this
5613 * point; there's no need to send SERVICE_REQUEST.
5614 */
5615
0ed48730 5616 ssh->channels = newtree234(ssh_channelcmp);
5617
7cca0d81 5618 /*
0ed48730 5619 * Create the main session channel.
7cca0d81 5620 */
0ed48730 5621 if (!ssh->cfg.ssh_no_shell) {
5622 ssh->mainchan = snew(struct ssh_channel);
5623 ssh->mainchan->ssh = ssh;
5624 ssh->mainchan->localid = alloc_channel_id(ssh);
5625 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5626 ssh2_pkt_addstring(ssh, "session");
5627 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5628 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5629 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5630 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5631 ssh2_pkt_send(ssh);
5632 crWaitUntilV(ispkt);
5633 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5634 bombout(("Server refused to open a session"));
5635 crStopV;
5636 /* FIXME: error data comes back in FAILURE packet */
5637 }
5638 if (ssh_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5639 bombout(("Server's channel confirmation cited wrong channel"));
5640 crStopV;
5641 }
5642 ssh->mainchan->remoteid = ssh_pkt_getuint32(ssh);
5643 ssh->mainchan->type = CHAN_MAINSESSION;
5644 ssh->mainchan->closes = 0;
5645 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(ssh);
5646 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
5647 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5648 add234(ssh->channels, ssh->mainchan);
5649 logevent("Opened channel for session");
5650 } else
5651 ssh->mainchan = NULL;
7cca0d81 5652
5653 /*
783415f8 5654 * Potentially enable X11 forwarding.
5655 */
0ed48730 5656 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 5657 char proto[20], data[64];
5658 logevent("Requesting X11 forwarding");
302121de 5659 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 5660 data, sizeof(data), ssh->cfg.x11_auth);
5661 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 5662 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5663 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5664 ssh2_pkt_addstring(ssh, "x11-req");
5665 ssh2_pkt_addbool(ssh, 1); /* want reply */
5666 ssh2_pkt_addbool(ssh, 0); /* many connections */
5667 ssh2_pkt_addstring(ssh, proto);
5668 ssh2_pkt_addstring(ssh, data);
86916870 5669 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
51470298 5670 ssh2_pkt_send(ssh);
32874aea 5671
5672 do {
5673 crWaitUntilV(ispkt);
51470298 5674 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
0016d70b 5675 unsigned i = ssh_pkt_getuint32(ssh);
32874aea 5676 struct ssh_channel *c;
51470298 5677 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5678 if (!c)
5679 continue; /* nonexistent channel */
0016d70b 5680 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
32874aea 5681 }
51470298 5682 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5683
51470298 5684 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5685 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5686 bombout(("Unexpected response to X11 forwarding request:"
51470298 5687 " packet type %d", ssh->pktin.type));
7ffdbc1a 5688 crStopV;
32874aea 5689 }
5690 logevent("X11 forwarding refused");
5691 } else {
5692 logevent("X11 forwarding enabled");
51470298 5693 ssh->X11_fwd_enabled = TRUE;
32874aea 5694 }
783415f8 5695 }
5696
5697 /*
bc240b21 5698 * Enable port forwardings.
5699 */
5700 {
bc240b21 5701 char type;
5702 int n;
a4fc0d74 5703 int sport,dport,sserv,dserv;
6ee9b735 5704 char sports[256], dports[256], saddr[256], host[256];
bc240b21 5705
51470298 5706 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 5707 /* Add port forwardings. */
86916870 5708 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 5709 while (*ssh->portfwd_strptr) {
5710 type = *ssh->portfwd_strptr++;
6ee9b735 5711 saddr[0] = '\0';
bc240b21 5712 n = 0;
6ee9b735 5713 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5714 if (*ssh->portfwd_strptr == ':') {
5715 /*
5716 * We've seen a colon in the middle of the
5717 * source port number. This means that
5718 * everything we've seen until now is the
5719 * source _address_, so we'll move it into
5720 * saddr and start sports from the beginning
5721 * again.
5722 */
5723 ssh->portfwd_strptr++;
5724 sports[n] = '\0';
5725 strcpy(saddr, sports);
5726 n = 0;
5727 }
5728 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5729 }
bc240b21 5730 sports[n] = 0;
820ebe3b 5731 if (type != 'D') {
5732 if (*ssh->portfwd_strptr == '\t')
5733 ssh->portfwd_strptr++;
5734 n = 0;
5735 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5736 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5737 }
5738 host[n] = 0;
5739 if (*ssh->portfwd_strptr == ':')
5740 ssh->portfwd_strptr++;
5741 n = 0;
5742 while (*ssh->portfwd_strptr) {
5743 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5744 }
5745 dports[n] = 0;
51470298 5746 ssh->portfwd_strptr++;
820ebe3b 5747 dport = atoi(dports);
5748 dserv = 0;
5749 if (dport == 0) {
5750 dserv = 1;
5751 dport = net_service_lookup(dports);
5752 if (!dport) {
5753 logeventf(ssh, "Service lookup failed for destination"
5754 " port \"%s\"", dports);
5755 }
a4fc0d74 5756 }
820ebe3b 5757 } else {
5758 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 5759 dport = dserv = -1;
7d5b0f4d 5760 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 5761 }
bc240b21 5762 sport = atoi(sports);
a4fc0d74 5763 sserv = 0;
5764 if (sport == 0) {
5765 sserv = 1;
68a49acb 5766 sport = net_service_lookup(sports);
5767 if (!sport) {
57356d63 5768 logeventf(ssh, "Service lookup failed for source"
5769 " port \"%s\"", sports);
a4fc0d74 5770 }
5771 }
bc240b21 5772 if (sport && dport) {
94ab1ddf 5773 /* Set up a description of the source port. */
5774 char *sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
5775 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5776 (int)(*saddr?1:0), ":",
5777 (int)(sserv ? strlen(sports) : 0), sports,
5778 sserv, "(", sport, sserv, ")");
bc240b21 5779 if (type == 'L') {
94ab1ddf 5780 /* Verbose description of the destination port */
5781 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
5782 host,
5783 (int)(dserv ? strlen(dports) : 0), dports,
5784 dserv, "(", dport, dserv, ")");
5785 const char *err = pfd_addforward(host, dport,
5786 *saddr ? saddr : NULL,
5787 sport, ssh, &ssh->cfg);
5788 if (err) {
5789 logeventf(ssh, "Local port %s forward to %s"
5790 " failed: %s", sportdesc, dportdesc, err);
5791 } else {
5792 logeventf(ssh, "Local port %s forwarding to %s",
5793 sportdesc, dportdesc);
5794 }
5795 sfree(dportdesc);
820ebe3b 5796 } else if (type == 'D') {
94ab1ddf 5797 const char *err = pfd_addforward(NULL, -1,
5798 *saddr ? saddr : NULL,
5799 sport, ssh, &ssh->cfg);
5800 if (err) {
5801 logeventf(ssh, "Local port %s SOCKS dynamic forward"
5802 " setup failed: %s", sportdesc, err);
5803 } else {
5804 logeventf(ssh, "Local port %s doing SOCKS"
5805 " dynamic forwarding", sportdesc);
5806 }
bc240b21 5807 } else {
5808 struct ssh_rportfwd *pf;
3d88e64d 5809 pf = snew(struct ssh_rportfwd);
bc240b21 5810 strcpy(pf->dhost, host);
5811 pf->dport = dport;
5812 pf->sport = sport;
51470298 5813 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 5814 logeventf(ssh, "Duplicate remote port forwarding"
5815 " to %s:%d", host, dport);
bc240b21 5816 sfree(pf);
5817 } else {
94ab1ddf 5818 logeventf(ssh, "Requesting remote port %s"
57356d63 5819 " forward to %s:%.*s%.*s%d%.*s",
94ab1ddf 5820 sportdesc,
57356d63 5821 host,
5822 (int)(dserv ? strlen(dports) : 0), dports,
5823 dserv, "(", dport, dserv, ")");
51470298 5824 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5825 ssh2_pkt_addstring(ssh, "tcpip-forward");
5826 ssh2_pkt_addbool(ssh, 1);/* want reply */
6ee9b735 5827 if (*saddr)
5828 ssh2_pkt_addstring(ssh, saddr);
86916870 5829 if (ssh->cfg.rport_acceptall)
51470298 5830 ssh2_pkt_addstring(ssh, "0.0.0.0");
beefa433 5831 else
51470298 5832 ssh2_pkt_addstring(ssh, "127.0.0.1");
5833 ssh2_pkt_adduint32(ssh, sport);
5834 ssh2_pkt_send(ssh);
bc240b21 5835
5836 do {
5837 crWaitUntilV(ispkt);
51470298 5838 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
0016d70b 5839 unsigned i = ssh_pkt_getuint32(ssh);
bc240b21 5840 struct ssh_channel *c;
51470298 5841 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5842 if (!c)
5843 continue;/* nonexistent channel */
0016d70b 5844 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
bc240b21 5845 }
51470298 5846 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
bc240b21 5847
51470298 5848 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5849 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
6b5cf8b4 5850 bombout(("Unexpected response to port "
c9886e66 5851 "forwarding request: packet type %d",
51470298 5852 ssh->pktin.type));
7ffdbc1a 5853 crStopV;
bc240b21 5854 }
5855 logevent("Server refused this port forwarding");
5856 } else {
5857 logevent("Remote port forwarding enabled");
5858 }
5859 }
5860 }
94ab1ddf 5861 sfree(sportdesc);
bc240b21 5862 }
5863 }
5864 }
5865
5866 /*
36c2a3e9 5867 * Potentially enable agent forwarding.
5868 */
0ed48730 5869 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 5870 logevent("Requesting OpenSSH-style agent forwarding");
51470298 5871 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5872 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5873 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5874 ssh2_pkt_addbool(ssh, 1); /* want reply */
5875 ssh2_pkt_send(ssh);
32874aea 5876
5877 do {
5878 crWaitUntilV(ispkt);
51470298 5879 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
0016d70b 5880 unsigned i = ssh_pkt_getuint32(ssh);
32874aea 5881 struct ssh_channel *c;
51470298 5882 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5883 if (!c)
5884 continue; /* nonexistent channel */
0016d70b 5885 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
32874aea 5886 }
51470298 5887 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5888
51470298 5889 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5890 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5891 bombout(("Unexpected response to agent forwarding request:"
51470298 5892 " packet type %d", ssh->pktin.type));
7ffdbc1a 5893 crStopV;
32874aea 5894 }
5895 logevent("Agent forwarding refused");
5896 } else {
5897 logevent("Agent forwarding enabled");
51470298 5898 ssh->agentfwd_enabled = TRUE;
32874aea 5899 }
36c2a3e9 5900 }
5901
5902 /*
7cca0d81 5903 * Now allocate a pty for the session.
5904 */
0ed48730 5905 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 5906 /* Unpick the terminal-speed string. */
5907 /* XXX perhaps we should allow no speeds to be sent. */
db219738 5908 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5909 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 5910 /* Build the pty request. */
51470298 5911 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5912 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5913 ssh2_pkt_addstring(ssh, "pty-req");
5914 ssh2_pkt_addbool(ssh, 1); /* want reply */
86916870 5915 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
51470298 5916 ssh2_pkt_adduint32(ssh, ssh->term_width);
5917 ssh2_pkt_adduint32(ssh, ssh->term_height);
5918 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5919 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5920 ssh2_pkt_addstring_start(ssh);
a5dd8467 5921 ssh2_pkt_addbyte(ssh, 128); /* TTY_OP_ISPEED */
db219738 5922 ssh2_pkt_adduint32(ssh, ssh->ispeed);
a5dd8467 5923 ssh2_pkt_addbyte(ssh, 129); /* TTY_OP_OSPEED */
db219738 5924 ssh2_pkt_adduint32(ssh, ssh->ospeed);
a5dd8467 5925 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END */
51470298 5926 ssh2_pkt_send(ssh);
5927 ssh->state = SSH_STATE_INTERMED;
32874aea 5928
5929 do {
5930 crWaitUntilV(ispkt);
51470298 5931 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
0016d70b 5932 unsigned i = ssh_pkt_getuint32(ssh);
32874aea 5933 struct ssh_channel *c;
51470298 5934 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5935 if (!c)
5936 continue; /* nonexistent channel */
0016d70b 5937 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
32874aea 5938 }
51470298 5939 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5940
51470298 5941 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5942 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5943 bombout(("Unexpected response to pty request:"
51470298 5944 " packet type %d", ssh->pktin.type));
7ffdbc1a 5945 crStopV;
32874aea 5946 }
51470298 5947 c_write_str(ssh, "Server refused to allocate pty\r\n");
5948 ssh->editing = ssh->echoing = 1;
32874aea 5949 } else {
a5dd8467 5950 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 5951 ssh->ospeed, ssh->ispeed);
32874aea 5952 }
0965bee0 5953 } else {
51470298 5954 ssh->editing = ssh->echoing = 1;
7cca0d81 5955 }
5956
5957 /*
73feed4f 5958 * Send environment variables.
5959 *
5960 * Simplest thing here is to send all the requests at once, and
5961 * then wait for a whole bunch of successes or failures.
5962 */
5963 if (ssh->mainchan && *ssh->cfg.environmt) {
5964 char *e = ssh->cfg.environmt;
5965 char *var, *varend, *val;
5966
5967 s->num_env = 0;
5968
5969 while (*e) {
5970 var = e;
5971 while (*e && *e != '\t') e++;
5972 varend = e;
5973 if (*e == '\t') e++;
5974 val = e;
5975 while (*e) e++;
5976 e++;
5977
5978 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5979 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5980 ssh2_pkt_addstring(ssh, "env");
5981 ssh2_pkt_addbool(ssh, 1); /* want reply */
5982 ssh2_pkt_addstring_start(ssh);
5983 ssh2_pkt_addstring_data(ssh, var, varend-var);
5984 ssh2_pkt_addstring(ssh, val);
5985 ssh2_pkt_send(ssh);
5986
5987 s->num_env++;
5988 }
5989
5990 logeventf(ssh, "Sent %d environment variables", s->num_env);
5991
5992 s->env_ok = 0;
5993 s->env_left = s->num_env;
5994
5995 while (s->env_left > 0) {
5996 do {
5997 crWaitUntilV(ispkt);
5998 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5999 unsigned i = ssh_pkt_getuint32(ssh);
6000 struct ssh_channel *c;
6001 c = find234(ssh->channels, &i, ssh_channelfind);
6002 if (!c)
6003 continue; /* nonexistent channel */
6004 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6005 }
6006 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6007
6008 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
6009 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6010 bombout(("Unexpected response to environment request:"
6011 " packet type %d", ssh->pktin.type));
6012 crStopV;
6013 }
6014 } else {
6015 s->env_ok++;
6016 }
6017
6018 s->env_left--;
6019 }
6020
6021 if (s->env_ok == s->num_env) {
6022 logevent("All environment variables successfully set");
6023 } else if (s->env_ok == 0) {
6024 logevent("All environment variables refused");
6025 c_write_str(ssh, "Server refused to set environment variables\r\n");
6026 } else {
6027 logeventf(ssh, "%d environment variables refused",
6028 s->num_env - s->env_ok);
6029 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6030 }
6031 }
6032
6033 /*
fd5e5847 6034 * Start a shell or a remote command. We may have to attempt
6035 * this twice if the config data has provided a second choice
6036 * of command.
7cca0d81 6037 */
0ed48730 6038 if (ssh->mainchan) while (1) {
fd5e5847 6039 int subsys;
6040 char *cmd;
6041
51470298 6042 if (ssh->fallback_cmd) {
86916870 6043 subsys = ssh->cfg.ssh_subsys2;
6044 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 6045 } else {
86916870 6046 subsys = ssh->cfg.ssh_subsys;
6047 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 6048 }
6049
51470298 6050 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6051 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 6052 if (subsys) {
51470298 6053 ssh2_pkt_addstring(ssh, "subsystem");
6054 ssh2_pkt_addbool(ssh, 1); /* want reply */
6055 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 6056 } else if (*cmd) {
51470298 6057 ssh2_pkt_addstring(ssh, "exec");
6058 ssh2_pkt_addbool(ssh, 1); /* want reply */
6059 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 6060 } else {
51470298 6061 ssh2_pkt_addstring(ssh, "shell");
6062 ssh2_pkt_addbool(ssh, 1); /* want reply */
32874aea 6063 }
51470298 6064 ssh2_pkt_send(ssh);
fd5e5847 6065 do {
6066 crWaitUntilV(ispkt);
51470298 6067 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
0016d70b 6068 unsigned i = ssh_pkt_getuint32(ssh);
fd5e5847 6069 struct ssh_channel *c;
51470298 6070 c = find234(ssh->channels, &i, ssh_channelfind);
fd5e5847 6071 if (!c)
6072 continue; /* nonexistent channel */
0016d70b 6073 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
fd5e5847 6074 }
51470298 6075 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6076 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
6077 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6078 bombout(("Unexpected response to shell/command request:"
51470298 6079 " packet type %d", ssh->pktin.type));
7ffdbc1a 6080 crStopV;
fd5e5847 6081 }
6082 /*
6083 * We failed to start the command. If this is the
6084 * fallback command, we really are finished; if it's
6085 * not, and if the fallback command exists, try falling
6086 * back to it before complaining.
6087 */
86916870 6088 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 6089 logevent("Primary command failed; attempting fallback");
51470298 6090 ssh->fallback_cmd = TRUE;
fd5e5847 6091 continue;
6092 }
6b5cf8b4 6093 bombout(("Server refused to start a shell/command"));
7ffdbc1a 6094 crStopV;
fd5e5847 6095 } else {
6096 logevent("Started a shell/command");
32874aea 6097 }
fd5e5847 6098 break;
7cca0d81 6099 }
6100
51470298 6101 ssh->state = SSH_STATE_SESSION;
6102 if (ssh->size_needed)
6103 ssh_size(ssh, ssh->term_width, ssh->term_height);
6104 if (ssh->eof_needed)
6105 ssh_special(ssh, TS_EOF);
6e48c3fe 6106
7cca0d81 6107 /*
6108 * Transfer data!
6109 */
b9d7bcad 6110 if (ssh->ldisc)
6111 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 6112 if (ssh->mainchan)
6113 ssh->send_ok = 1;
7cca0d81 6114 while (1) {
e5574168 6115 crReturnV;
51470298 6116 s->try_send = FALSE;
7cca0d81 6117 if (ispkt) {
51470298 6118 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
6119 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
32874aea 6120 char *data;
6121 int length;
0016d70b 6122 unsigned i = ssh_pkt_getuint32(ssh);
32874aea 6123 struct ssh_channel *c;
51470298 6124 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 6125 if (!c)
6126 continue; /* nonexistent channel */
51470298 6127 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
0016d70b 6128 ssh_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
32874aea 6129 continue; /* extended but not stderr */
0016d70b 6130 ssh_pkt_getstring(ssh, &data, &length);
32874aea 6131 if (data) {
7ffdbc1a 6132 int bufsize = 0;
5471d09a 6133 c->v.v2.locwindow -= length;
32874aea 6134 switch (c->type) {
6135 case CHAN_MAINSESSION:
5471d09a 6136 bufsize =
51470298 6137 from_backend(ssh->frontend, ssh->pktin.type ==
5471d09a 6138 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6139 data, length);
32874aea 6140 break;
6141 case CHAN_X11:
5471d09a 6142 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 6143 break;
d74d141c 6144 case CHAN_SOCKDATA:
5471d09a 6145 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 6146 break;
36c2a3e9 6147 case CHAN_AGENT:
32874aea 6148 while (length > 0) {
6149 if (c->u.a.lensofar < 4) {
6150 int l = min(4 - c->u.a.lensofar, length);
6151 memcpy(c->u.a.msglen + c->u.a.lensofar,
6152 data, l);
6153 data += l;
6154 length -= l;
6155 c->u.a.lensofar += l;
6156 }
6157 if (c->u.a.lensofar == 4) {
6158 c->u.a.totallen =
6159 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 6160 c->u.a.message = snewn(c->u.a.totallen,
6161 unsigned char);
32874aea 6162 memcpy(c->u.a.message, c->u.a.msglen, 4);
6163 }
6164 if (c->u.a.lensofar >= 4 && length > 0) {
6165 int l =
6166 min(c->u.a.totallen - c->u.a.lensofar,
6167 length);
6168 memcpy(c->u.a.message + c->u.a.lensofar,
6169 data, l);
6170 data += l;
6171 length -= l;
6172 c->u.a.lensofar += l;
6173 }
6174 if (c->u.a.lensofar == c->u.a.totallen) {
839f10db 6175 void *reply;
32874aea 6176 int replylen;
839f10db 6177 if (agent_query(c->u.a.message,
6178 c->u.a.totallen,
6179 &reply, &replylen,
6180 ssh_agentf_callback, c))
6181 ssh_agentf_callback(c, reply, replylen);
32874aea 6182 sfree(c->u.a.message);
6183 c->u.a.lensofar = 0;
6184 }
6185 }
5471d09a 6186 bufsize = 0;
32874aea 6187 break;
6188 }
6189 /*
5471d09a 6190 * If we are not buffering too much data,
6191 * enlarge the window again at the remote side.
32874aea 6192 */
5471d09a 6193 if (bufsize < OUR_V2_WINSIZE)
6194 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 6195 }
51470298 6196 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
0016d70b 6197 unsigned i = ssh_pkt_getuint32(ssh);
32874aea 6198 struct ssh_channel *c;
6199
51470298 6200 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 6201 if (!c)
6202 continue; /* nonexistent channel */
6203
6204 if (c->type == CHAN_X11) {
6205 /*
6206 * Remote EOF on an X11 channel means we should
6207 * wrap up and close the channel ourselves.
6208 */
6209 x11_close(c->u.x11.s);
6210 sshfwd_close(c);
6211 } else if (c->type == CHAN_AGENT) {
36c2a3e9 6212 sshfwd_close(c);
d74d141c 6213 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 6214 pfd_close(c->u.pfd.s);
6215 sshfwd_close(c);
36c2a3e9 6216 }
51470298 6217 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
0016d70b 6218 unsigned i = ssh_pkt_getuint32(ssh);
32874aea 6219 struct ssh_channel *c;
6220
51470298 6221 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 6222 if (!c || ((int)c->remoteid) == -1) {
6b5cf8b4 6223 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
d0d844c1 6224 c ? "half-open" : "nonexistent", i));
7ffdbc1a 6225 crStopV;
d0d844c1 6226 }
32874aea 6227 /* Do pre-close processing on the channel. */
6228 switch (c->type) {
6229 case CHAN_MAINSESSION:
6230 break; /* nothing to see here, move along */
6231 case CHAN_X11:
92f157bd 6232 if (c->u.x11.s != NULL)
6233 x11_close(c->u.x11.s);
6234 sshfwd_close(c);
32874aea 6235 break;
6236 case CHAN_AGENT:
92f157bd 6237 sshfwd_close(c);
32874aea 6238 break;
d74d141c 6239 case CHAN_SOCKDATA:
92f157bd 6240 if (c->u.pfd.s != NULL)
6241 pfd_close(c->u.pfd.s);
6242 sshfwd_close(c);
bc240b21 6243 break;
32874aea 6244 }
92f157bd 6245 if (c->closes == 0) {
51470298 6246 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6247 ssh2_pkt_adduint32(ssh, c->remoteid);
6248 ssh2_pkt_send(ssh);
92f157bd 6249 }
51470298 6250 del234(ssh->channels, c);
5471d09a 6251 bufchain_clear(&c->v.v2.outbuffer);
32874aea 6252 sfree(c);
6253
6254 /*
6255 * See if that was the last channel left open.
0ed48730 6256 * (This is only our termination condition if we're
6257 * not running in -N mode.)
32874aea 6258 */
0ed48730 6259 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
3bb2f322 6260 logevent("All channels closed. Disconnecting");
ca2914d1 6261#if 0
6262 /*
6263 * We used to send SSH_MSG_DISCONNECT here,
6264 * because I'd believed that _every_ conforming
6265 * SSH2 connection had to end with a disconnect
6266 * being sent by at least one side; apparently
6267 * I was wrong and it's perfectly OK to
6268 * unceremoniously slam the connection shut
6269 * when you're done, and indeed OpenSSH feels
6270 * this is more polite than sending a
6271 * DISCONNECT. So now we don't.
6272 */
51470298 6273 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6274 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6275 ssh2_pkt_addstring(ssh, "All open channels closed");
6276 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6277 ssh2_pkt_send(ssh);
ca2914d1 6278#endif
3bb2f322 6279 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6280 crStopV;
32874aea 6281 }
6282 continue; /* remote sends close; ignore (FIXME) */
51470298 6283 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
0016d70b 6284 unsigned i = ssh_pkt_getuint32(ssh);
32874aea 6285 struct ssh_channel *c;
51470298 6286 c = find234(ssh->channels, &i, ssh_channelfind);
a6253970 6287 if (!c || c->closes)
6288 continue; /* nonexistent or closing channel */
0016d70b 6289 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
51470298 6290 s->try_send = TRUE;
6291 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0016d70b 6292 unsigned i = ssh_pkt_getuint32(ssh);
bc240b21 6293 struct ssh_channel *c;
51470298 6294 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 6295 if (!c)
6296 continue; /* nonexistent channel */
6297 if (c->type != CHAN_SOCKDATA_DORMANT)
6298 continue; /* dunno why they're confirming this */
0016d70b 6299 c->remoteid = ssh_pkt_getuint32(ssh);
bc240b21 6300 c->type = CHAN_SOCKDATA;
0016d70b 6301 c->v.v2.remwindow = ssh_pkt_getuint32(ssh);
6302 c->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
4ed34d25 6303 if (c->u.pfd.s)
6304 pfd_confirm(c->u.pfd.s);
6305 if (c->closes) {
6306 /*
6307 * We have a pending close on this channel,
6308 * which we decided on before the server acked
6309 * the channel open. So now we know the
6310 * remoteid, we can close it again.
6311 */
51470298 6312 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6313 ssh2_pkt_adduint32(ssh, c->remoteid);
6314 ssh2_pkt_send(ssh);
4ed34d25 6315 }
51470298 6316 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
e595953d 6317 static const char *const reasons[] = {
6318 "<unknown reason code>",
6319 "Administratively prohibited",
6320 "Connect failed",
6321 "Unknown channel type",
6322 "Resource shortage",
6323 };
0016d70b 6324 unsigned i = ssh_pkt_getuint32(ssh);
e595953d 6325 unsigned reason_code;
6326 char *reason_string;
6327 int reason_length;
6328 char *message;
724cface 6329 struct ssh_channel *c;
51470298 6330 c = find234(ssh->channels, &i, ssh_channelfind);
724cface 6331 if (!c)
6332 continue; /* nonexistent channel */
6333 if (c->type != CHAN_SOCKDATA_DORMANT)
6334 continue; /* dunno why they're failing this */
6335
e595953d 6336 reason_code = ssh_pkt_getuint32(ssh);
6337 if (reason_code >= lenof(reasons))
6338 reason_code = 0; /* ensure reasons[reason_code] in range */
6339 ssh_pkt_getstring(ssh, &reason_string, &reason_length);
6340 message = dupprintf("Forwarded connection refused by"
6341 " server: %s [%.*s]", reasons[reason_code],
6342 reason_length, reason_string);
6343 logevent(message);
6344 sfree(message);
724cface 6345
6346 pfd_close(c->u.pfd.s);
6347
51470298 6348 del234(ssh->channels, c);
724cface 6349 sfree(c);
51470298 6350 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
ebb0a590 6351 unsigned localid;
6352 char *type;
6353 int typelen, want_reply;
6354 struct ssh_channel *c;
6355
0016d70b 6356 localid = ssh_pkt_getuint32(ssh);
6357 ssh_pkt_getstring(ssh, &type, &typelen);
51470298 6358 want_reply = ssh2_pkt_getbool(ssh);
ebb0a590 6359
6360 /*
6361 * First, check that the channel exists. Otherwise,
6362 * we can instantly disconnect with a rude message.
6363 */
51470298 6364 c = find234(ssh->channels, &localid, ssh_channelfind);
ebb0a590 6365 if (!c) {
6366 char buf[80];
6367 sprintf(buf, "Received channel request for nonexistent"
6368 " channel %d", localid);
6369 logevent(buf);
51470298 6370 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6371 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6372 ssh2_pkt_addstring(ssh, buf);
6373 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6374 ssh2_pkt_send(ssh);
6b5cf8b4 6375 connection_fatal(ssh->frontend, "%s", buf);
3bb2f322 6376 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6377 crStopV;
ebb0a590 6378 }
6379
6380 /*
d8d6c7e5 6381 * Having got the channel number, we now look at
6382 * the request type string to see if it's something
6383 * we recognise.
ebb0a590 6384 */
d8d6c7e5 6385 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
51470298 6386 c == ssh->mainchan) {
d8d6c7e5 6387 /* We recognise "exit-status" on the primary channel. */
6388 char buf[100];
0016d70b 6389 ssh->exitcode = ssh_pkt_getuint32(ssh);
d8d6c7e5 6390 sprintf(buf, "Server sent command exit status %d",
51470298 6391 ssh->exitcode);
d8d6c7e5 6392 logevent(buf);
6393 if (want_reply) {
51470298 6394 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
6395 ssh2_pkt_adduint32(ssh, c->remoteid);
6396 ssh2_pkt_send(ssh);
d8d6c7e5 6397 }
6398 } else {
6399 /*
6400 * This is a channel request we don't know
6401 * about, so we now either ignore the request
6402 * or respond with CHANNEL_FAILURE, depending
6403 * on want_reply.
6404 */
6405 if (want_reply) {
51470298 6406 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
6407 ssh2_pkt_adduint32(ssh, c->remoteid);
6408 ssh2_pkt_send(ssh);
d8d6c7e5 6409 }
ebb0a590 6410 }
51470298 6411 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
697d4856 6412 char *type;
6413 int typelen, want_reply;
6414
0016d70b 6415 ssh_pkt_getstring(ssh, &type, &typelen);
51470298 6416 want_reply = ssh2_pkt_getbool(ssh);
697d4856 6417
6418 /*
6419 * We currently don't support any global requests
6420 * at all, so we either ignore the request or
6421 * respond with REQUEST_FAILURE, depending on
6422 * want_reply.
6423 */
6424 if (want_reply) {
51470298 6425 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
6426 ssh2_pkt_send(ssh);
697d4856 6427 }
51470298 6428 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 6429 char *type;
6430 int typelen;
b3ebaa28 6431 char *peeraddr;
6432 int peeraddrlen;
2e5b14c0 6433 int peerport;
32874aea 6434 char *error = NULL;
6435 struct ssh_channel *c;
bc240b21 6436 unsigned remid, winsize, pktsize;
0016d70b 6437 ssh_pkt_getstring(ssh, &type, &typelen);
3d88e64d 6438 c = snew(struct ssh_channel);
51470298 6439 c->ssh = ssh;
32874aea 6440
0016d70b 6441 remid = ssh_pkt_getuint32(ssh);
6442 winsize = ssh_pkt_getuint32(ssh);
6443 pktsize = ssh_pkt_getuint32(ssh);
bc240b21 6444
32874aea 6445 if (typelen == 3 && !memcmp(type, "x11", 3)) {
df85f78b 6446 char *addrstr;
6447
0016d70b 6448 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
df85f78b 6449 addrstr = snewn(peeraddrlen+1, char);
b3ebaa28 6450 memcpy(addrstr, peeraddr, peeraddrlen);
5a9bf764 6451 addrstr[peeraddrlen] = '\0';
0016d70b 6452 peerport = ssh_pkt_getuint32(ssh);
b3ebaa28 6453
5a9bf764 6454 logeventf(ssh, "Received X11 connect request from %s:%d",
6455 addrstr, peerport);
6456
51470298 6457 if (!ssh->X11_fwd_enabled)
32874aea 6458 error = "X11 forwarding is not enabled";
86916870 6459 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
2e5b14c0 6460 ssh->x11auth, addrstr, peerport,
e8fa8f62 6461 &ssh->cfg) != NULL) {
32874aea 6462 error = "Unable to open an X11 connection";
6463 } else {
5a9bf764 6464 logevent("Opening X11 forward connection succeeded");
32874aea 6465 c->type = CHAN_X11;
6466 }
b3ebaa28 6467
6468 sfree(addrstr);
bc240b21 6469 } else if (typelen == 15 &&
6470 !memcmp(type, "forwarded-tcpip", 15)) {
6471 struct ssh_rportfwd pf, *realpf;
6472 char *dummy;
6473 int dummylen;
0016d70b 6474 ssh_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6475 pf.sport = ssh_pkt_getuint32(ssh);
6476 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6477 peerport = ssh_pkt_getuint32(ssh);
51470298 6478 realpf = find234(ssh->rportfwds, &pf, NULL);
5a9bf764 6479 logeventf(ssh, "Received remote port %d open request "
6480 "from %s:%d", pf.sport, peeraddr, peerport);
bc240b21 6481 if (realpf == NULL) {
6482 error = "Remote port is not recognised";
6483 } else {
cbe2d68f 6484 const char *e = pfd_newconnect(&c->u.pfd.s,
6485 realpf->dhost,
6486 realpf->dport, c,
6487 &ssh->cfg);
5a9bf764 6488 logeventf(ssh, "Attempting to forward remote port to "
6489 "%s:%d", realpf->dhost, realpf->dport);
bc240b21 6490 if (e != NULL) {
57356d63 6491 logeventf(ssh, "Port open failed: %s", e);
bc240b21 6492 error = "Port open failed";
6493 } else {
6494 logevent("Forwarded port opened successfully");
6495 c->type = CHAN_SOCKDATA;
6496 }
6497 }
32874aea 6498 } else if (typelen == 22 &&
36c2a3e9 6499 !memcmp(type, "auth-agent@openssh.com", 3)) {
51470298 6500 if (!ssh->agentfwd_enabled)
32874aea 6501 error = "Agent forwarding is not enabled";
36c2a3e9 6502 else {
32874aea 6503 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 6504 c->u.a.lensofar = 0;
32874aea 6505 }
6506 } else {
6507 error = "Unsupported channel type requested";
6508 }
6509
bc240b21 6510 c->remoteid = remid;
32874aea 6511 if (error) {
51470298 6512 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6513 ssh2_pkt_adduint32(ssh, c->remoteid);
6514 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6515 ssh2_pkt_addstring(ssh, error);
6516 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6517 ssh2_pkt_send(ssh);
5a9bf764 6518 logeventf(ssh, "Rejected channel open: %s", error);
32874aea 6519 sfree(c);
6520 } else {
51470298 6521 c->localid = alloc_channel_id(ssh);
32874aea 6522 c->closes = 0;
5471d09a 6523 c->v.v2.locwindow = OUR_V2_WINSIZE;
6524 c->v.v2.remwindow = winsize;
6525 c->v.v2.remmaxpkt = pktsize;
6526 bufchain_init(&c->v.v2.outbuffer);
51470298 6527 add234(ssh->channels, c);
6528 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6529 ssh2_pkt_adduint32(ssh, c->remoteid);
6530 ssh2_pkt_adduint32(ssh, c->localid);
6531 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6532 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6533 ssh2_pkt_send(ssh);
32874aea 6534 }
7cca0d81 6535 } else {
6b5cf8b4 6536 bombout(("Strange packet received: type %d", ssh->pktin.type));
7ffdbc1a 6537 crStopV;
7cca0d81 6538 }
0ed48730 6539 } else if (ssh->mainchan) {
32874aea 6540 /*
6541 * We have spare data. Add it to the channel buffer.
6542 */
d8baa528 6543 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 6544 s->try_send = TRUE;
32874aea 6545 }
51470298 6546 if (s->try_send) {
32874aea 6547 int i;
6548 struct ssh_channel *c;
6549 /*
6550 * Try to send data on all channels if we can.
6551 */
51470298 6552 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 6553 int bufsize;
6554 if (c->closes)
6555 continue; /* don't send on closing channels */
6556 bufsize = ssh2_try_send(c);
5471d09a 6557 if (bufsize == 0) {
6558 switch (c->type) {
6559 case CHAN_MAINSESSION:
6560 /* stdin need not receive an unthrottle
6561 * notification since it will be polled */
6562 break;
6563 case CHAN_X11:
6564 x11_unthrottle(c->u.x11.s);
6565 break;
6566 case CHAN_AGENT:
6567 /* agent sockets are request/response and need no
6568 * buffer management */
6569 break;
6570 case CHAN_SOCKDATA:
6571 pfd_unthrottle(c->u.pfd.s);
6572 break;
6573 }
6574 }
6575 }
7cca0d81 6576 }
e5574168 6577 }
6578
6579 crFinishV;
6580}
6581
6582/*
7cca0d81 6583 * Handle the top-level SSH2 protocol.
6584 */
51470298 6585static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 6586{
51470298 6587 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
32874aea 6588 return;
51470298 6589 do_ssh2_authconn(ssh, in, inlen, ispkt);
7cca0d81 6590}
6591
6592/*
8df7a775 6593 * Called to set up the connection.
374330e2 6594 *
6595 * Returns an error message, or NULL on success.
374330e2 6596 */
cbe2d68f 6597static const char *ssh_init(void *frontend_handle, void **backend_handle,
6598 Config *cfg,
79bf227b 6599 char *host, int port, char **realhost, int nodelay,
6600 int keepalive)
32874aea 6601{
cbe2d68f 6602 const char *p;
51470298 6603 Ssh ssh;
6604
3d88e64d 6605 ssh = snew(struct ssh_tag);
86916870 6606 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 6607 ssh->version = 0; /* when not ready yet */
51470298 6608 ssh->s = NULL;
6609 ssh->cipher = NULL;
371e569c 6610 ssh->v1_cipher_ctx = NULL;
0183b242 6611 ssh->crcda_ctx = NULL;
51470298 6612 ssh->cscipher = NULL;
371e569c 6613 ssh->cs_cipher_ctx = NULL;
51470298 6614 ssh->sccipher = NULL;
371e569c 6615 ssh->sc_cipher_ctx = NULL;
51470298 6616 ssh->csmac = NULL;
a8327734 6617 ssh->cs_mac_ctx = NULL;
51470298 6618 ssh->scmac = NULL;
e0e1a00d 6619 ssh->sc_mac_ctx = NULL;
51470298 6620 ssh->cscomp = NULL;
5366aed8 6621 ssh->cs_comp_ctx = NULL;
51470298 6622 ssh->sccomp = NULL;
5366aed8 6623 ssh->sc_comp_ctx = NULL;
51470298 6624 ssh->kex = NULL;
389aa499 6625 ssh->kex_ctx = NULL;
51470298 6626 ssh->hostkey = NULL;
6627 ssh->exitcode = -1;
6628 ssh->state = SSH_STATE_PREPACKET;
6629 ssh->size_needed = FALSE;
6630 ssh->eof_needed = FALSE;
b9d7bcad 6631 ssh->ldisc = NULL;
a8327734 6632 ssh->logctx = NULL;
51470298 6633 {
6634 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6635 ssh->pktin = ssh->pktout = empty;
6636 }
6637 ssh->deferred_send_data = NULL;
6638 ssh->deferred_len = 0;
6639 ssh->deferred_size = 0;
9a10ecf4 6640 ssh->pktout_logmode = PKTLOG_EMIT;
6641 ssh->pktout_nblanks = 0;
6642 ssh->pktout_blanks = NULL;
51470298 6643 ssh->fallback_cmd = 0;
6644 ssh->pkt_ctx = 0;
302121de 6645 ssh->x11auth = NULL;
be738459 6646 ssh->v1_compressing = FALSE;
51470298 6647 ssh->v2_outgoing_sequence = 0;
6648 ssh->ssh1_rdpkt_crstate = 0;
6649 ssh->ssh2_rdpkt_crstate = 0;
6650 ssh->do_ssh_init_crstate = 0;
6651 ssh->ssh_gotdata_crstate = 0;
6652 ssh->ssh1_protocol_crstate = 0;
6653 ssh->do_ssh1_login_crstate = 0;
6654 ssh->do_ssh2_transport_crstate = 0;
6655 ssh->do_ssh2_authconn_crstate = 0;
6656 ssh->do_ssh_init_state = NULL;
6657 ssh->do_ssh1_login_state = NULL;
6658 ssh->do_ssh2_transport_state = NULL;
6659 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 6660 ssh->mainchan = NULL;
968d2d92 6661 ssh->throttled_all = 0;
6662 ssh->v1_stdout_throttling = 0;
51470298 6663
6664 *backend_handle = ssh;
32874aea 6665
8f203108 6666#ifdef MSCRYPTOAPI
32874aea 6667 if (crypto_startup() == 0)
8f203108 6668 return "Microsoft high encryption pack not installed!";
6669#endif
374330e2 6670
51470298 6671 ssh->frontend = frontend_handle;
86916870 6672 ssh->term_width = ssh->cfg.width;
6673 ssh->term_height = ssh->cfg.height;
887035a5 6674
fabd1805 6675 ssh->channels = NULL;
6676 ssh->rportfwds = NULL;
6677
51470298 6678 ssh->send_ok = 0;
6679 ssh->editing = 0;
6680 ssh->echoing = 0;
6681 ssh->v1_throttle_count = 0;
6682 ssh->overall_bufsize = 0;
6683 ssh->fallback_cmd = 0;
8df7a775 6684
3648d4c5 6685 ssh->protocol = NULL;
6686
79bf227b 6687 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 6688 if (p != NULL)
6689 return p;
374330e2 6690
374330e2 6691 return NULL;
6692}
6693
fabd1805 6694static void ssh_free(void *handle)
6695{
6696 Ssh ssh = (Ssh) handle;
6697 struct ssh_channel *c;
6698 struct ssh_rportfwd *pf;
6699
6700 if (ssh->v1_cipher_ctx)
6701 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6702 if (ssh->cs_cipher_ctx)
6703 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6704 if (ssh->sc_cipher_ctx)
6705 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6706 if (ssh->cs_mac_ctx)
6707 ssh->csmac->free_context(ssh->cs_mac_ctx);
6708 if (ssh->sc_mac_ctx)
6709 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 6710 if (ssh->cs_comp_ctx) {
6711 if (ssh->cscomp)
6712 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6713 else
6714 zlib_compress_cleanup(ssh->cs_comp_ctx);
6715 }
6716 if (ssh->sc_comp_ctx) {
6717 if (ssh->sccomp)
6718 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6719 else
6720 zlib_decompress_cleanup(ssh->sc_comp_ctx);
6721 }
fabd1805 6722 if (ssh->kex_ctx)
6723 dh_cleanup(ssh->kex_ctx);
6724 sfree(ssh->savedhost);
6725
6726 if (ssh->channels) {
6727 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6728 switch (c->type) {
6729 case CHAN_X11:
6730 if (c->u.x11.s != NULL)
6731 x11_close(c->u.x11.s);
6732 break;
6733 case CHAN_SOCKDATA:
6734 if (c->u.pfd.s != NULL)
6735 pfd_close(c->u.pfd.s);
6736 break;
6737 }
6738 sfree(c);
6739 }
6740 freetree234(ssh->channels);
6741 }
6742
6743 if (ssh->rportfwds) {
6744 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6745 sfree(pf);
6746 freetree234(ssh->rportfwds);
6747 }
6748 sfree(ssh->deferred_send_data);
6749 if (ssh->x11auth)
6750 x11_free_auth(ssh->x11auth);
6751 sfree(ssh->do_ssh_init_state);
6752 sfree(ssh->do_ssh1_login_state);
6753 sfree(ssh->do_ssh2_transport_state);
6754 sfree(ssh->do_ssh2_authconn_state);
679539d7 6755 if (ssh->pktout.data) {
6756 sfree(ssh->pktout.data);
6757 ssh->pktout.data = NULL;
6758 }
6759 if (ssh->pktin.data) {
6760 sfree(ssh->pktin.data);
6761 ssh->pktin.data = NULL;
6762 }
6763 if (ssh->crcda_ctx) {
6764 crcda_free_context(ssh->crcda_ctx);
6765 ssh->crcda_ctx = NULL;
6766 }
fabd1805 6767 if (ssh->s)
36f94d1f 6768 ssh_do_close(ssh);
fabd1805 6769 sfree(ssh);
6770}
6771
374330e2 6772/*
86916870 6773 * Reconfigure the SSH backend.
6774 *
6775 * Currently, this function does nothing very useful. In future,
6776 * however, we could do some handy things with it. For example, we
6777 * could make the port forwarding configurer active in the Change
6778 * Settings box, and this routine could close down existing
6779 * forwardings and open up new ones in response to changes.
6780 */
6781static void ssh_reconfig(void *handle, Config *cfg)
6782{
6783 Ssh ssh = (Ssh) handle;
6784 ssh->cfg = *cfg; /* STRUCTURE COPY */
6785}
6786
6787/*
374330e2 6788 * Called to send data down the Telnet connection.
6789 */
51470298 6790static int ssh_send(void *handle, char *buf, int len)
32874aea 6791{
51470298 6792 Ssh ssh = (Ssh) handle;
6793
6794 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6795 return 0;
374330e2 6796
d8baa528 6797 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 6798
51470298 6799 return ssh_sendbuffer(ssh);
5471d09a 6800}
6801
6802/*
6803 * Called to query the current amount of buffered stdin data.
6804 */
51470298 6805static int ssh_sendbuffer(void *handle)
5471d09a 6806{
51470298 6807 Ssh ssh = (Ssh) handle;
5471d09a 6808 int override_value;
6809
51470298 6810 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6811 return 0;
6812
6813 /*
6814 * If the SSH socket itself has backed up, add the total backup
6815 * size on that to any individual buffer on the stdin channel.
6816 */
6817 override_value = 0;
51470298 6818 if (ssh->throttled_all)
6819 override_value = ssh->overall_bufsize;
5471d09a 6820
51470298 6821 if (ssh->version == 1) {
5471d09a 6822 return override_value;
51470298 6823 } else if (ssh->version == 2) {
6824 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 6825 return override_value;
6826 else
51470298 6827 return (override_value +
6828 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 6829 }
6830
6831 return 0;
374330e2 6832}
6833
6834/*
6e48c3fe 6835 * Called to set the size of the window from SSH's POV.
374330e2 6836 */
51470298 6837static void ssh_size(void *handle, int width, int height)
32874aea 6838{
51470298 6839 Ssh ssh = (Ssh) handle;
6840
6841 ssh->term_width = width;
6842 ssh->term_height = height;
f278d6f8 6843
51470298 6844 switch (ssh->state) {
374330e2 6845 case SSH_STATE_BEFORE_SIZE:
3687d221 6846 case SSH_STATE_PREPACKET:
21248260 6847 case SSH_STATE_CLOSED:
374330e2 6848 break; /* do nothing */
6849 case SSH_STATE_INTERMED:
51470298 6850 ssh->size_needed = TRUE; /* buffer for later */
374330e2 6851 break;
6852 case SSH_STATE_SESSION:
86916870 6853 if (!ssh->cfg.nopty) {
51470298 6854 if (ssh->version == 1) {
6855 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6856 PKT_INT, ssh->term_height,
6857 PKT_INT, ssh->term_width,
32874aea 6858 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 6859 } else if (ssh->mainchan) {
51470298 6860 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6861 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6862 ssh2_pkt_addstring(ssh, "window-change");
6863 ssh2_pkt_addbool(ssh, 0);
6864 ssh2_pkt_adduint32(ssh, ssh->term_width);
6865 ssh2_pkt_adduint32(ssh, ssh->term_height);
6866 ssh2_pkt_adduint32(ssh, 0);
6867 ssh2_pkt_adduint32(ssh, 0);
6868 ssh2_pkt_send(ssh);
32874aea 6869 }
6870 }
6871 break;
374330e2 6872 }
6873}
6874
6875/*
125105d1 6876 * Return a list of the special codes that make sense in this
6877 * protocol.
6878 */
6879static const struct telnet_special *ssh_get_specials(void *handle)
6880{
6881 Ssh ssh = (Ssh) handle;
6882
6883 if (ssh->version == 1) {
6884 static const struct telnet_special ssh1_specials[] = {
6885 {"IGNORE message", TS_NOP},
6886 {NULL, 0}
6887 };
6888 return ssh1_specials;
6889 } else if (ssh->version == 2) {
6890 static const struct telnet_special ssh2_specials[] = {
6891 {"Break", TS_BRK},
6892 {"IGNORE message", TS_NOP},
6893 {NULL, 0}
6894 };
6895 return ssh2_specials;
6896 } else
6897 return NULL;
6898}
6899
6900/*
6abbf9e3 6901 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6902 * can send an EOF and collect resulting output (e.g. `plink
6903 * hostname sort').
374330e2 6904 */
51470298 6905static void ssh_special(void *handle, Telnet_Special code)
32874aea 6906{
51470298 6907 Ssh ssh = (Ssh) handle;
6908
6abbf9e3 6909 if (code == TS_EOF) {
51470298 6910 if (ssh->state != SSH_STATE_SESSION) {
32874aea 6911 /*
6912 * Buffer the EOF in case we are pre-SESSION, so we can
6913 * send it as soon as we reach SESSION.
6914 */
6915 if (code == TS_EOF)
51470298 6916 ssh->eof_needed = TRUE;
32874aea 6917 return;
6918 }
51470298 6919 if (ssh->version == 1) {
6920 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 6921 } else if (ssh->mainchan) {
51470298 6922 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6923 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6924 ssh2_pkt_send(ssh);
32874aea 6925 }
6926 logevent("Sent EOF message");
125105d1 6927 } else if (code == TS_PING || code == TS_NOP) {
51470298 6928 if (ssh->state == SSH_STATE_CLOSED
6929 || ssh->state == SSH_STATE_PREPACKET) return;
6930 if (ssh->version == 1) {
6931 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6932 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 6933 } else {
51470298 6934 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6935 ssh2_pkt_addstring_start(ssh);
6936 ssh2_pkt_send(ssh);
32874aea 6937 }
125105d1 6938 } else if (code == TS_BRK) {
6939 if (ssh->state == SSH_STATE_CLOSED
6940 || ssh->state == SSH_STATE_PREPACKET) return;
6941 if (ssh->version == 1) {
6942 logevent("Unable to send BREAK signal in SSH1");
0ed48730 6943 } else if (ssh->mainchan) {
125105d1 6944 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6945 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6946 ssh2_pkt_addstring(ssh, "break");
6947 ssh2_pkt_addbool(ssh, 0);
6948 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6949 ssh2_pkt_send(ssh);
6950 }
6abbf9e3 6951 } else {
32874aea 6952 /* do nothing */
6abbf9e3 6953 }
374330e2 6954}
6955
51470298 6956void *new_sock_channel(void *handle, Socket s)
d74d141c 6957{
51470298 6958 Ssh ssh = (Ssh) handle;
d74d141c 6959 struct ssh_channel *c;
3d88e64d 6960 c = snew(struct ssh_channel);
51470298 6961 c->ssh = ssh;
d74d141c 6962
6963 if (c) {
bc240b21 6964 c->remoteid = -1; /* to be set when open confirmed */
51470298 6965 c->localid = alloc_channel_id(ssh);
d74d141c 6966 c->closes = 0;
bc240b21 6967 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 6968 c->u.pfd.s = s;
013dd8c0 6969 bufchain_init(&c->v.v2.outbuffer);
51470298 6970 add234(ssh->channels, c);
d74d141c 6971 }
6972 return c;
6973}
6974
5471d09a 6975/*
6976 * This is called when stdout/stderr (the entity to which
6977 * from_backend sends data) manages to clear some backlog.
6978 */
ae9ae89f 6979static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 6980{
51470298 6981 Ssh ssh = (Ssh) handle;
6982 if (ssh->version == 1) {
6983 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6984 ssh->v1_stdout_throttling = 0;
6985 ssh1_throttle(ssh, -1);
5471d09a 6986 }
6987 } else {
51470298 6988 if (ssh->mainchan && ssh->mainchan->closes == 0)
6989 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 6990 }
6991}
6992
6b78788a 6993void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 6994{
6995 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 6996 Ssh ssh = c->ssh;
d74d141c 6997
57356d63 6998 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 6999
51470298 7000 if (ssh->version == 1) {
7001 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7002 PKT_INT, c->localid,
7003 PKT_STR, hostname,
7004 PKT_INT, port,
7005 //PKT_STR, <org:orgport>,
7006 PKT_END);
7007 } else {
51470298 7008 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
7009 ssh2_pkt_addstring(ssh, "direct-tcpip");
7010 ssh2_pkt_adduint32(ssh, c->localid);
5471d09a 7011 c->v.v2.locwindow = OUR_V2_WINSIZE;
51470298 7012 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
7013 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
7014 ssh2_pkt_addstring(ssh, hostname);
7015 ssh2_pkt_adduint32(ssh, port);
bc240b21 7016 /*
7017 * We make up values for the originator data; partly it's
7018 * too much hassle to keep track, and partly I'm not
7019 * convinced the server should be told details like that
7020 * about my local network configuration.
7021 */
51470298 7022 ssh2_pkt_addstring(ssh, "client-side-connection");
7023 ssh2_pkt_adduint32(ssh, 0);
7024 ssh2_pkt_send(ssh);
bc240b21 7025 }
d74d141c 7026}
7027
7028
51470298 7029static Socket ssh_socket(void *handle)
32874aea 7030{
51470298 7031 Ssh ssh = (Ssh) handle;
7032 return ssh->s;
32874aea 7033}
8ccc75b0 7034
51470298 7035static int ssh_sendok(void *handle)
32874aea 7036{
51470298 7037 Ssh ssh = (Ssh) handle;
7038 return ssh->send_ok;
32874aea 7039}
fb09bf1c 7040
51470298 7041static int ssh_ldisc(void *handle, int option)
32874aea 7042{
51470298 7043 Ssh ssh = (Ssh) handle;
32874aea 7044 if (option == LD_ECHO)
51470298 7045 return ssh->echoing;
32874aea 7046 if (option == LD_EDIT)
51470298 7047 return ssh->editing;
0965bee0 7048 return FALSE;
7049}
7050
b9d7bcad 7051static void ssh_provide_ldisc(void *handle, void *ldisc)
7052{
7053 Ssh ssh = (Ssh) handle;
7054 ssh->ldisc = ldisc;
7055}
7056
a8327734 7057static void ssh_provide_logctx(void *handle, void *logctx)
7058{
7059 Ssh ssh = (Ssh) handle;
7060 ssh->logctx = logctx;
7061}
7062
51470298 7063static int ssh_return_exitcode(void *handle)
7064{
7065 Ssh ssh = (Ssh) handle;
3bb2f322 7066 if (ssh->s != NULL)
7067 return -1;
7068 else
7069 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7070}
7071
7072/*
7073 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7074 * that fails. This variable is the means by which scp.c can reach
7075 * into the SSH code and find out which one it got.
7076 */
7077extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7078{
51470298 7079 Ssh ssh = (Ssh) handle;
7080 return ssh->fallback_cmd;
d8d6c7e5 7081}
7082
374330e2 7083Backend ssh_backend = {
7084 ssh_init,
fabd1805 7085 ssh_free,
86916870 7086 ssh_reconfig,
374330e2 7087 ssh_send,
5471d09a 7088 ssh_sendbuffer,
374330e2 7089 ssh_size,
4017be6d 7090 ssh_special,
125105d1 7091 ssh_get_specials,
8ccc75b0 7092 ssh_socket,
d8d6c7e5 7093 ssh_return_exitcode,
97db3be4 7094 ssh_sendok,
0965bee0 7095 ssh_ldisc,
b9d7bcad 7096 ssh_provide_ldisc,
a8327734 7097 ssh_provide_logctx,
5471d09a 7098 ssh_unthrottle,
97db3be4 7099 22
bc240b21 7100};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator