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Kimmo Parviainen points out that SSH software version strings have
[sgt/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5
6#include "putty.h"
dacbd0e8 7#include "tree234.h"
fb09bf1c 8#include "ssh.h"
374330e2 9
10#ifndef FALSE
11#define FALSE 0
12#endif
13#ifndef TRUE
14#define TRUE 1
15#endif
16
32874aea 17#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20#define SSH1_CMSG_USER 4 /* 0x4 */
21#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29#define SSH1_SMSG_SUCCESS 14 /* 0xe */
30#define SSH1_SMSG_FAILURE 15 /* 0xf */
31#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34#define SSH1_CMSG_EOF 19 /* 0x13 */
35#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46#define SSH1_MSG_IGNORE 32 /* 0x20 */
47#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50#define SSH1_MSG_DEBUG 36 /* 0x24 */
51#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
58
59#define SSH1_AUTH_TIS 5 /* 0x5 */
60#define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 63/* Mask for protoflags we will echo back to server if seen */
32874aea 64#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
66#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67#define SSH2_MSG_IGNORE 2 /* 0x2 */
68#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69#define SSH2_MSG_DEBUG 4 /* 0x4 */
70#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72#define SSH2_MSG_KEXINIT 20 /* 0x14 */
73#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 86#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 88#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
102
00db133f 103/*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
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;
ff3187f6 319struct Packet;
320
321static struct Packet *ssh2_pkt_init(int pkt_type);
322static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
323static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
324static void ssh2_pkt_addstring_start(struct Packet *);
325static void ssh2_pkt_addstring_str(struct Packet *, char *data);
326static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
327static void ssh2_pkt_addstring(struct Packet *, char *data);
d8baa528 328static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
ff3187f6 329static void ssh2_pkt_addmp(struct Packet *, Bignum b);
330static int ssh2_pkt_construct(Ssh, struct Packet *);
331static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 332static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 333static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
334 struct Packet *pktin);
335static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
336 struct Packet *pktin);
3d63ca2e 337
5471d09a 338/*
339 * Buffer management constants. There are several of these for
340 * various different purposes:
341 *
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
346 * happen very often.
347 *
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
354 *
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
356 * channels.
357 */
358
359#define SSH1_BUFFER_LIMIT 32768
360#define SSH_MAX_BACKLOG 32768
361#define OUR_V2_WINSIZE 16384
d74d141c 362
a92dd380 363const static struct ssh_kex *kex_algs[] = {
a92dd380 364 &ssh_diffiehellman_gex,
32874aea 365 &ssh_diffiehellman
366};
e5574168 367
85cc02bb 368const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 369
e0e1a00d 370static void *nullmac_make_context(void)
371{
372 return NULL;
373}
374static void nullmac_free_context(void *handle)
375{
376}
377static void nullmac_key(void *handle, unsigned char *key)
32874aea 378{
379}
e0e1a00d 380static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 381 unsigned long seq)
382{
383}
e0e1a00d 384static int nullmac_verify(void *handle, unsigned char *blk, int len,
385 unsigned long seq)
32874aea 386{
387 return 1;
388}
57476f6b 389const static struct ssh_mac ssh_mac_none = {
e0e1a00d 390 nullmac_make_context, nullmac_free_context, nullmac_key,
391 nullmac_generate, nullmac_verify, "none", 0
e5574168 392};
8b2715b2 393const static struct ssh_mac *macs[] = {
32874aea 394 &ssh_sha1, &ssh_md5, &ssh_mac_none
395};
8b2715b2 396const static struct ssh_mac *buggymacs[] = {
32874aea 397 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
398};
e5574168 399
5366aed8 400static void *ssh_comp_none_init(void)
401{
402 return NULL;
403}
404static void ssh_comp_none_cleanup(void *handle)
32874aea 405{
406}
5366aed8 407static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 408 unsigned char **outblock, int *outlen)
409{
410 return 0;
411}
5366aed8 412static int ssh_comp_none_disable(void *handle)
32874aea 413{
4ba9b64b 414 return 0;
415}
57476f6b 416const static struct ssh_compress ssh_comp_none = {
4ba9b64b 417 "none",
5366aed8 418 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
419 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
420 ssh_comp_none_disable, NULL
e5574168 421};
4ba9b64b 422extern const struct ssh_compress ssh_zlib;
423const static struct ssh_compress *compressions[] = {
32874aea 424 &ssh_zlib, &ssh_comp_none
425};
374330e2 426
32874aea 427enum { /* channel types */
783415f8 428 CHAN_MAINSESSION,
429 CHAN_X11,
430 CHAN_AGENT,
bc240b21 431 CHAN_SOCKDATA,
432 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 433};
434
dacbd0e8 435/*
436 * 2-3-4 tree storing channels.
437 */
438struct ssh_channel {
51470298 439 Ssh ssh; /* pointer back to main context */
d211621f 440 unsigned remoteid, localid;
dacbd0e8 441 int type;
0357890f 442 /*
443 * In SSH1, this value contains four bits:
444 *
445 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
446 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
447 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
448 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
449 *
450 * A channel is completely finished with when all four bits are set.
451 */
dacbd0e8 452 int closes;
5471d09a 453 union {
454 struct ssh1_data_channel {
455 int throttling;
456 } v1;
457 struct ssh2_data_channel {
458 bufchain outbuffer;
459 unsigned remwindow, remmaxpkt;
460 unsigned locwindow;
461 } v2;
462 } v;
dacbd0e8 463 union {
32874aea 464 struct ssh_agent_channel {
465 unsigned char *message;
466 unsigned char msglen[4];
a03c9f9c 467 unsigned lensofar, totallen;
32874aea 468 } a;
469 struct ssh_x11_channel {
470 Socket s;
471 } x11;
d74d141c 472 struct ssh_pfd_channel {
473 Socket s;
474 } pfd;
dacbd0e8 475 } u;
476};
57476f6b 477
d74d141c 478/*
bc240b21 479 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
480 * 2 use this structure in different ways, reflecting SSH 2's
481 * altogether saner approach to port forwarding.
482 *
483 * In SSH 1, you arrange a remote forwarding by sending the server
484 * the remote port number, and the local destination host:port.
485 * When a connection comes in, the server sends you back that
486 * host:port pair, and you connect to it. This is a ready-made
487 * security hole if you're not on the ball: a malicious server
488 * could send you back _any_ host:port pair, so if you trustingly
489 * connect to the address it gives you then you've just opened the
490 * entire inside of your corporate network just by connecting
491 * through it to a dodgy SSH server. Hence, we must store a list of
492 * host:port pairs we _are_ trying to forward to, and reject a
493 * connection request from the server if it's not in the list.
494 *
495 * In SSH 2, each side of the connection minds its own business and
496 * doesn't send unnecessary information to the other. You arrange a
497 * remote forwarding by sending the server just the remote port
498 * number. When a connection comes in, the server tells you which
499 * of its ports was connected to; and _you_ have to remember what
500 * local host:port pair went with that port number.
501 *
502 * Hence: in SSH 1 this structure stores host:port pairs we intend
503 * to allow connections to, and is indexed by those host:port
504 * pairs. In SSH 2 it stores a mapping from source port to
505 * destination host:port pair, and is indexed by source port.
d74d141c 506 */
507struct ssh_rportfwd {
bc240b21 508 unsigned sport, dport;
509 char dhost[256];
d74d141c 510};
511
57476f6b 512struct Packet {
513 long length;
514 int type;
b09eaa88 515 unsigned long sequence;
57476f6b 516 unsigned char *data;
517 unsigned char *body;
518 long savedpos;
519 long maxlen;
9442dd57 520 long encrypted_len; /* for SSH2 total-size counting */
ff3187f6 521
522 /*
523 * State associated with packet logging
524 */
525 int logmode;
526 int nblanks;
527 struct logblank_t *blanks;
57476f6b 528};
529
ff3187f6 530static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
531 struct Packet *pktin);
532static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
533 struct Packet *pktin);
b09eaa88 534static void ssh1_protocol_setup(Ssh ssh);
535static void ssh2_protocol_setup(Ssh ssh);
51470298 536static void ssh_size(void *handle, int width, int height);
537static void ssh_special(void *handle, Telnet_Special);
5471d09a 538static int ssh2_try_send(struct ssh_channel *c);
51470298 539static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
540static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 541static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 542static int ssh_sendbuffer(void *handle);
36f94d1f 543static void ssh_do_close(Ssh ssh);
ff3187f6 544static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
545static int ssh2_pkt_getbool(struct Packet *pkt);
546static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 547static void ssh2_timer(void *ctx, long now);
548static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
549 struct Packet *pktin);
57476f6b 550
51470298 551struct rdpkt1_state_tag {
57476f6b 552 long len, pad, biglen, to_read;
553 unsigned long realcrc, gotcrc;
554 unsigned char *p;
555 int i;
556 int chunk;
ff3187f6 557 struct Packet *pktin;
51470298 558};
57476f6b 559
51470298 560struct rdpkt2_state_tag {
960e736a 561 long len, pad, payload, packetlen, maclen;
562 int i;
563 int cipherblk;
564 unsigned long incoming_sequence;
ff3187f6 565 struct Packet *pktin;
51470298 566};
567
b09eaa88 568typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
569
51470298 570struct ssh_tag {
571 const struct plug_function_table *fn;
572 /* the above field _must_ be first in the structure */
573
574 SHA_State exhash, exhashbase;
575
576 Socket s;
577
b9d7bcad 578 void *ldisc;
a8327734 579 void *logctx;
b9d7bcad 580
51470298 581 unsigned char session_key[32];
582 int v1_compressing;
583 int v1_remote_protoflags;
584 int v1_local_protoflags;
585 int agentfwd_enabled;
586 int X11_fwd_enabled;
587 int remote_bugs;
588 const struct ssh_cipher *cipher;
371e569c 589 void *v1_cipher_ctx;
0183b242 590 void *crcda_ctx;
51470298 591 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 592 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 593 const struct ssh_mac *csmac, *scmac;
e0e1a00d 594 void *cs_mac_ctx, *sc_mac_ctx;
51470298 595 const struct ssh_compress *cscomp, *sccomp;
5366aed8 596 void *cs_comp_ctx, *sc_comp_ctx;
51470298 597 const struct ssh_kex *kex;
598 const struct ssh_signkey *hostkey;
599 unsigned char v2_session_id[20];
27cd7fc2 600 void *kex_ctx;
51470298 601
602 char *savedhost;
603 int savedport;
604 int send_ok;
605 int echoing, editing;
606
607 void *frontend;
608
db219738 609 int ospeed, ispeed; /* temporaries */
51470298 610 int term_width, term_height;
611
612 tree234 *channels; /* indexed by local id */
613 struct ssh_channel *mainchan; /* primary session channel */
614 int exitcode;
615
616 tree234 *rportfwds;
617
618 enum {
619 SSH_STATE_PREPACKET,
620 SSH_STATE_BEFORE_SIZE,
621 SSH_STATE_INTERMED,
622 SSH_STATE_SESSION,
623 SSH_STATE_CLOSED
624 } state;
625
626 int size_needed, eof_needed;
627
590f6a5f 628 struct Packet **queue;
629 int queuelen, queuesize;
630 int queueing;
51470298 631 unsigned char *deferred_send_data;
632 int deferred_len, deferred_size;
633
634 /*
635 * Gross hack: pscp will try to start SFTP but fall back to
636 * scp1 if that fails. This variable is the means by which
637 * scp.c can reach into the SSH code and find out which one it
638 * got.
639 */
640 int fallback_cmd;
641
642 /*
643 * Used for username and password input.
644 */
645 char *userpass_input_buffer;
646 int userpass_input_buflen;
647 int userpass_input_bufpos;
648 int userpass_input_echo;
649
650 char *portfwd_strptr;
651 int pkt_ctx;
652
302121de 653 void *x11auth;
654
51470298 655 int version;
656 int v1_throttle_count;
657 int overall_bufsize;
658 int throttled_all;
659 int v1_stdout_throttling;
660 int v2_outgoing_sequence;
661
662 int ssh1_rdpkt_crstate;
663 int ssh2_rdpkt_crstate;
664 int do_ssh_init_crstate;
665 int ssh_gotdata_crstate;
51470298 666 int do_ssh1_login_crstate;
b09eaa88 667 int do_ssh1_connection_crstate;
51470298 668 int do_ssh2_transport_crstate;
669 int do_ssh2_authconn_crstate;
670
671 void *do_ssh_init_state;
672 void *do_ssh1_login_state;
673 void *do_ssh2_transport_state;
674 void *do_ssh2_authconn_state;
675
676 struct rdpkt1_state_tag rdpkt1_state;
677 struct rdpkt2_state_tag rdpkt2_state;
678
b09eaa88 679 /* ssh1 and ssh2 use this for different things, but both use it */
680 int protocol_initial_phase_done;
681
ff3187f6 682 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
683 struct Packet *pkt);
684 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 685
686 /*
687 * We maintain a full _copy_ of a Config structure here, not
688 * merely a pointer to it. That way, when we're passed a new
689 * one for reconfiguration, we can check the differences and
690 * potentially reconfigure port forwardings etc in mid-session.
691 */
692 Config cfg;
839f10db 693
694 /*
695 * Used to transfer data back from async agent callbacks.
696 */
697 void *agent_response;
698 int agent_response_len;
b09eaa88 699
700 /*
701 * Dispatch table for packet types that we may have to deal
702 * with at any time.
703 */
704 handler_fn_t packet_dispatch[256];
39934deb 705
706 /*
707 * This module deals with sending keepalives.
708 */
709 Pinger pinger;
9442dd57 710
711 /*
712 * Track incoming and outgoing data sizes and time, for
713 * size-based rekeys.
714 */
715 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
716 int kex_in_progress;
717 long next_rekey;
51470298 718};
960e736a 719
9442dd57 720#define MAX_DATA_BEFORE_REKEY (0x40000000UL)
721#define REKEY_TIMEOUT (3600 * TICKSPERSEC)
722
382908ad 723#define logevent(s) logevent(ssh->frontend, s)
a8327734 724
725/* logevent, only printf-formatted. */
cbe2d68f 726static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 727{
728 va_list ap;
57356d63 729 char *buf;
a8327734 730
731 va_start(ap, fmt);
57356d63 732 buf = dupvprintf(fmt, ap);
a8327734 733 va_end(ap);
57356d63 734 logevent(buf);
57356d63 735 sfree(buf);
a8327734 736}
737
6b5cf8b4 738#define bombout(msg) \
739 do { \
740 char *text = dupprintf msg; \
36f94d1f 741 ssh_do_close(ssh); \
6b5cf8b4 742 logevent(text); \
743 connection_fatal(ssh->frontend, "%s", text); \
744 sfree(text); \
745 } while (0)
a8327734 746
9a10ecf4 747/* Functions to leave bits out of the SSH packet log file. */
748
ff3187f6 749static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 750{
751 if (ssh->cfg.logomitpass)
ff3187f6 752 pkt->logmode = blanktype;
9a10ecf4 753}
754
ff3187f6 755static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 756{
757 if (ssh->cfg.logomitdata)
ff3187f6 758 pkt->logmode = blanktype;
9a10ecf4 759}
760
ff3187f6 761static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 762{
ff3187f6 763 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 764}
765
32874aea 766static int ssh_channelcmp(void *av, void *bv)
767{
768 struct ssh_channel *a = (struct ssh_channel *) av;
769 struct ssh_channel *b = (struct ssh_channel *) bv;
770 if (a->localid < b->localid)
771 return -1;
772 if (a->localid > b->localid)
773 return +1;
dacbd0e8 774 return 0;
775}
32874aea 776static int ssh_channelfind(void *av, void *bv)
777{
778 unsigned *a = (unsigned *) av;
779 struct ssh_channel *b = (struct ssh_channel *) bv;
780 if (*a < b->localid)
781 return -1;
782 if (*a > b->localid)
783 return +1;
dacbd0e8 784 return 0;
785}
786
bc240b21 787static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 788{
789 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
790 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
791 int i;
bc240b21 792 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 793 return i < 0 ? -1 : +1;
bc240b21 794 if (a->dport > b->dport)
795 return +1;
796 if (a->dport < b->dport)
797 return -1;
798 return 0;
799}
800
801static int ssh_rportcmp_ssh2(void *av, void *bv)
802{
803 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
804 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 805
bc240b21 806 if (a->sport > b->sport)
d74d141c 807 return +1;
bc240b21 808 if (a->sport < b->sport)
809 return -1;
d74d141c 810 return 0;
811}
812
51470298 813static int alloc_channel_id(Ssh ssh)
32874aea 814{
260f3dec 815 const unsigned CHANNEL_NUMBER_OFFSET = 256;
816 unsigned low, high, mid;
d2371c81 817 int tsize;
818 struct ssh_channel *c;
819
820 /*
821 * First-fit allocation of channel numbers: always pick the
822 * lowest unused one. To do this, binary-search using the
823 * counted B-tree to find the largest channel ID which is in a
824 * contiguous sequence from the beginning. (Precisely
825 * everything in that sequence must have ID equal to its tree
826 * index plus CHANNEL_NUMBER_OFFSET.)
827 */
51470298 828 tsize = count234(ssh->channels);
d2371c81 829
32874aea 830 low = -1;
831 high = tsize;
d2371c81 832 while (high - low > 1) {
833 mid = (high + low) / 2;
51470298 834 c = index234(ssh->channels, mid);
d2371c81 835 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
836 low = mid; /* this one is fine */
837 else
838 high = mid; /* this one is past it */
839 }
840 /*
841 * Now low points to either -1, or the tree index of the
842 * largest ID in the initial sequence.
843 */
844 {
845 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 846 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 847 }
848 return low + 1 + CHANNEL_NUMBER_OFFSET;
849}
850
9fab77dc 851static void c_write(Ssh ssh, const char *buf, int len)
32874aea 852{
67779be7 853 if ((flags & FLAG_STDERR)) {
32874aea 854 int i;
855 for (i = 0; i < len; i++)
856 if (buf[i] != '\r')
857 fputc(buf[i], stderr);
fb09bf1c 858 return;
859 }
51470298 860 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 861}
862
9fab77dc 863static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 864{
a209e957 865 int i;
866 for (i = 0; i < len; i++) {
32874aea 867 if (buf[i] == '\n')
51470298 868 c_write(ssh, "\r\n", 2);
32874aea 869 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 870 c_write(ssh, buf + i, 1);
a209e957 871 }
872}
873
9fab77dc 874static void c_write_str(Ssh ssh, const char *buf)
32874aea 875{
51470298 876 c_write(ssh, buf, strlen(buf));
1408a877 877}
878
ff3187f6 879static void ssh_free_packet(struct Packet *pkt)
880{
881 sfree(pkt->data);
882 sfree(pkt);
883}
884static struct Packet *ssh_new_packet(void)
885{
886 struct Packet *pkt = snew(struct Packet);
887
888 pkt->data = NULL;
889 pkt->maxlen = 0;
890 pkt->logmode = PKTLOG_EMIT;
891 pkt->nblanks = 0;
892 pkt->blanks = NULL;
893
894 return pkt;
895}
896
fb09bf1c 897/*
898 * Collect incoming data in the incoming packet buffer.
e5574168 899 * Decipher and verify the packet when it is completely read.
900 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 901 * Update the *data and *datalen variables.
ff3187f6 902 * Return a Packet structure when a packet is completed.
fb09bf1c 903 */
ff3187f6 904static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 905{
51470298 906 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 907
51470298 908 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 909
ff3187f6 910 st->pktin = ssh_new_packet();
911
912 st->pktin->type = 0;
913 st->pktin->length = 0;
374330e2 914
57476f6b 915 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 916 while ((*datalen) == 0)
ff3187f6 917 crReturn(NULL);
57476f6b 918 st->len = (st->len << 8) + **data;
fb09bf1c 919 (*data)++, (*datalen)--;
920 }
374330e2 921
57476f6b 922 st->pad = 8 - (st->len % 8);
923 st->biglen = st->len + st->pad;
ff3187f6 924 st->pktin->length = st->len - 5;
fb09bf1c 925
ae0500e5 926 if (st->biglen < 0) {
927 bombout(("Extremely large packet length from server suggests"
928 " data stream corruption"));
ff3187f6 929 ssh_free_packet(st->pktin);
930 crStop(NULL);
ae0500e5 931 }
932
ff3187f6 933 st->pktin->maxlen = st->biglen;
934 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 935
57476f6b 936 st->to_read = st->biglen;
ff3187f6 937 st->p = st->pktin->data;
57476f6b 938 while (st->to_read > 0) {
32874aea 939 st->chunk = st->to_read;
fb09bf1c 940 while ((*datalen) == 0)
ff3187f6 941 crReturn(NULL);
57476f6b 942 if (st->chunk > (*datalen))
943 st->chunk = (*datalen);
944 memcpy(st->p, *data, st->chunk);
945 *data += st->chunk;
946 *datalen -= st->chunk;
947 st->p += st->chunk;
948 st->to_read -= st->chunk;
fb09bf1c 949 }
374330e2 950
ff3187f6 951 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 952 st->biglen, NULL)) {
6b5cf8b4 953 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 954 ssh_free_packet(st->pktin);
955 crStop(NULL);
9a3a93a5 956 }
957
51470298 958 if (ssh->cipher)
ff3187f6 959 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 960
ff3187f6 961 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
962 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 963 if (st->gotcrc != st->realcrc) {
6b5cf8b4 964 bombout(("Incorrect CRC received on packet"));
ff3187f6 965 ssh_free_packet(st->pktin);
966 crStop(NULL);
fb09bf1c 967 }
572f871e 968
ff3187f6 969 st->pktin->body = st->pktin->data + st->pad + 1;
970 st->pktin->savedpos = 0;
4ba9b64b 971
51470298 972 if (ssh->v1_compressing) {
4ba9b64b 973 unsigned char *decompblk;
974 int decomplen;
36b8d9bb 975 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 976 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 977 &decompblk, &decomplen)) {
978 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 979 ssh_free_packet(st->pktin);
980 crStop(NULL);
36b8d9bb 981 }
4ba9b64b 982
ff3187f6 983 if (st->pktin->maxlen < st->pad + decomplen) {
984 st->pktin->maxlen = st->pad + decomplen;
985 st->pktin->data = sresize(st->pktin->data,
986 st->pktin->maxlen + APIEXTRA,
3d88e64d 987 unsigned char);
ff3187f6 988 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 989 }
990
ff3187f6 991 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 992 sfree(decompblk);
ff3187f6 993 st->pktin->length = decomplen - 1;
4ba9b64b 994 }
995
ff3187f6 996 st->pktin->type = st->pktin->body[-1];
00db133f 997
9a10ecf4 998 /*
999 * Log incoming packet, possibly omitting sensitive fields.
1000 */
1001 if (ssh->logctx) {
1002 int nblanks = 0;
1003 struct logblank_t blank;
1004 if (ssh->cfg.logomitdata) {
1005 int do_blank = FALSE, blank_prefix = 0;
1006 /* "Session data" packets - omit the data field */
ff3187f6 1007 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1008 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1009 do_blank = TRUE; blank_prefix = 0;
ff3187f6 1010 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
9a10ecf4 1011 do_blank = TRUE; blank_prefix = 4;
1012 }
1013 if (do_blank) {
1014 blank.offset = blank_prefix;
ff3187f6 1015 blank.len = st->pktin->length;
9a10ecf4 1016 blank.type = PKTLOG_OMIT;
1017 nblanks = 1;
1018 }
1019 }
a8327734 1020 log_packet(ssh->logctx,
ff3187f6 1021 PKT_INCOMING, st->pktin->type,
1022 ssh1_pkt_type(st->pktin->type),
1023 st->pktin->body, st->pktin->length,
9a10ecf4 1024 nblanks, &blank);
1025 }
00db133f 1026
ff3187f6 1027 crFinish(st->pktin);
fb09bf1c 1028}
1029
ff3187f6 1030static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1031{
51470298 1032 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1033
51470298 1034 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1035
ff3187f6 1036 st->pktin = ssh_new_packet();
1037
1038 st->pktin->type = 0;
1039 st->pktin->length = 0;
51470298 1040 if (ssh->sccipher)
1041 st->cipherblk = ssh->sccipher->blksize;
e5574168 1042 else
32874aea 1043 st->cipherblk = 8;
960e736a 1044 if (st->cipherblk < 8)
32874aea 1045 st->cipherblk = 8;
960e736a 1046
ff3187f6 1047 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1048
1049 /*
1050 * Acquire and decrypt the first block of the packet. This will
1051 * contain the length and padding details.
1052 */
32874aea 1053 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1054 while ((*datalen) == 0)
ff3187f6 1055 crReturn(NULL);
1056 st->pktin->data[st->i] = *(*data)++;
32874aea 1057 (*datalen)--;
e5574168 1058 }
4252c9cc 1059
51470298 1060 if (ssh->sccipher)
371e569c 1061 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1062 st->pktin->data, st->cipherblk);
e5574168 1063
1064 /*
1065 * Now get the length and padding figures.
1066 */
ff3187f6 1067 st->len = GET_32BIT(st->pktin->data);
1068 st->pad = st->pktin->data[4];
e5574168 1069
1070 /*
717dc483 1071 * _Completely_ silly lengths should be stomped on before they
1072 * do us any more damage.
1073 */
1074 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 1075 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1076 ssh_free_packet(st->pktin);
1077 crStop(NULL);
717dc483 1078 }
1079
1080 /*
e5574168 1081 * This enables us to deduce the payload length.
1082 */
960e736a 1083 st->payload = st->len - st->pad - 1;
e5574168 1084
ff3187f6 1085 st->pktin->length = st->payload + 5;
e5574168 1086
1087 /*
1088 * So now we can work out the total packet length.
1089 */
960e736a 1090 st->packetlen = st->len + 4;
51470298 1091 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1092
1093 /*
ff3187f6 1094 * Allocate memory for the rest of the packet.
e5574168 1095 */
ff3187f6 1096 st->pktin->maxlen = st->packetlen + st->maclen;
1097 st->pktin->data = sresize(st->pktin->data,
1098 st->pktin->maxlen + APIEXTRA,
1099 unsigned char);
e5574168 1100
1101 /*
1102 * Read and decrypt the remainder of the packet.
1103 */
32874aea 1104 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1105 st->i++) {
e5574168 1106 while ((*datalen) == 0)
ff3187f6 1107 crReturn(NULL);
1108 st->pktin->data[st->i] = *(*data)++;
32874aea 1109 (*datalen)--;
e5574168 1110 }
1111 /* Decrypt everything _except_ the MAC. */
51470298 1112 if (ssh->sccipher)
371e569c 1113 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1114 st->pktin->data + st->cipherblk,
51470298 1115 st->packetlen - st->cipherblk);
e5574168 1116
9442dd57 1117 st->pktin->encrypted_len = st->packetlen;
1118
e5574168 1119 /*
1120 * Check the MAC.
1121 */
51470298 1122 if (ssh->scmac
ff3187f6 1123 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1124 st->incoming_sequence)) {
6b5cf8b4 1125 bombout(("Incorrect MAC received on packet"));
ff3187f6 1126 ssh_free_packet(st->pktin);
1127 crStop(NULL);
8d5de777 1128 }
b09eaa88 1129
1130 st->pktin->sequence = st->incoming_sequence++;
e5574168 1131
4ba9b64b 1132 /*
1133 * Decompress packet payload.
1134 */
1135 {
1136 unsigned char *newpayload;
1137 int newlen;
51470298 1138 if (ssh->sccomp &&
5366aed8 1139 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1140 st->pktin->data + 5, st->pktin->length - 5,
51470298 1141 &newpayload, &newlen)) {
ff3187f6 1142 if (st->pktin->maxlen < newlen + 5) {
1143 st->pktin->maxlen = newlen + 5;
1144 st->pktin->data = sresize(st->pktin->data,
1145 st->pktin->maxlen + APIEXTRA,
3d88e64d 1146 unsigned char);
4ba9b64b 1147 }
ff3187f6 1148 st->pktin->length = 5 + newlen;
1149 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1150 sfree(newpayload);
4ba9b64b 1151 }
1152 }
1153
ff3187f6 1154 st->pktin->savedpos = 6;
1155 st->pktin->body = st->pktin->data;
1156 st->pktin->type = st->pktin->data[5];
e5574168 1157
9a10ecf4 1158 /*
1159 * Log incoming packet, possibly omitting sensitive fields.
1160 */
1161 if (ssh->logctx) {
1162 int nblanks = 0;
1163 struct logblank_t blank;
1164 if (ssh->cfg.logomitdata) {
1165 int do_blank = FALSE, blank_prefix = 0;
1166 /* "Session data" packets - omit the data field */
ff3187f6 1167 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1168 do_blank = TRUE; blank_prefix = 4;
ff3187f6 1169 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
9a10ecf4 1170 do_blank = TRUE; blank_prefix = 8;
1171 }
1172 if (do_blank) {
1173 blank.offset = blank_prefix;
ff3187f6 1174 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1175 blank.type = PKTLOG_OMIT;
1176 nblanks = 1;
1177 }
1178 }
ff3187f6 1179 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1180 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1181 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1182 nblanks, &blank);
1183 }
00db133f 1184
ff3187f6 1185 crFinish(st->pktin);
e5574168 1186}
1187
ff3187f6 1188static void ssh1_pktout_size(struct Packet *pkt, int len)
32874aea 1189{
374330e2 1190 int pad, biglen;
1191
1192 len += 5; /* type and CRC */
32874aea 1193 pad = 8 - (len % 8);
374330e2 1194 biglen = len + pad;
1195
ff3187f6 1196 pkt->length = len - 5;
1197 if (pkt->maxlen < biglen) {
1198 pkt->maxlen = biglen;
1199 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
374330e2 1200 }
ff3187f6 1201 pkt->body = pkt->data + 4 + pad + 1;
4ba9b64b 1202}
374330e2 1203
ff3187f6 1204static struct Packet *s_wrpkt_start(int type, int len)
32874aea 1205{
ff3187f6 1206 struct Packet *pkt = ssh_new_packet();
1207 ssh1_pktout_size(pkt, len);
1208 pkt->type = type;
9a10ecf4 1209 /* Initialise log omission state */
ff3187f6 1210 pkt->nblanks = 0;
1211 pkt->blanks = NULL;
1212 return pkt;
374330e2 1213}
1214
ff3187f6 1215static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
32874aea 1216{
fd7a4aad 1217 int pad, biglen, i;
374330e2 1218 unsigned long crc;
fd7a4aad 1219#ifdef __SC__
1220 /*
1221 * XXX various versions of SC (including 8.8.4) screw up the
1222 * register allocation in this function and use the same register
1223 * (D6) for len and as a temporary, with predictable results. The
1224 * following sledgehammer prevents this.
1225 */
1226 volatile
1227#endif
1228 int len;
374330e2 1229
ff3187f6 1230 pkt->body[-1] = pkt->type;
4ba9b64b 1231
a8327734 1232 if (ssh->logctx)
ff3187f6 1233 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1234 ssh1_pkt_type(pkt->type),
1235 pkt->body, pkt->length,
1236 pkt->nblanks, pkt->blanks);
1237 sfree(pkt->blanks); pkt->blanks = NULL;
1238 pkt->nblanks = 0;
00db133f 1239
51470298 1240 if (ssh->v1_compressing) {
4ba9b64b 1241 unsigned char *compblk;
1242 int complen;
5366aed8 1243 zlib_compress_block(ssh->cs_comp_ctx,
ff3187f6 1244 pkt->body - 1, pkt->length + 1,
4ba9b64b 1245 &compblk, &complen);
ff3187f6 1246 ssh1_pktout_size(pkt, complen - 1);
1247 memcpy(pkt->body - 1, compblk, complen);
dcbde236 1248 sfree(compblk);
4ba9b64b 1249 }
1250
ff3187f6 1251 len = pkt->length + 5; /* type and CRC */
32874aea 1252 pad = 8 - (len % 8);
374330e2 1253 biglen = len + pad;
1254
32874aea 1255 for (i = 0; i < pad; i++)
ff3187f6 1256 pkt->data[i + 4] = random_byte();
1257 crc = crc32_compute(pkt->data + 4, biglen - 4);
1258 PUT_32BIT(pkt->data + biglen, crc);
1259 PUT_32BIT(pkt->data, len);
374330e2 1260
51470298 1261 if (ssh->cipher)
ff3187f6 1262 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
374330e2 1263
32874aea 1264 return biglen + 4;
39065bed 1265}
1266
ff3187f6 1267static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1268{
5471d09a 1269 int len, backlog;
ff3187f6 1270 len = s_wrpkt_prepare(ssh, pkt);
1271 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1272 if (backlog > SSH_MAX_BACKLOG)
51470298 1273 ssh_throttle_all(ssh, 1, backlog);
39065bed 1274}
1275
ff3187f6 1276static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1277{
39065bed 1278 int len;
ff3187f6 1279 len = s_wrpkt_prepare(ssh, pkt);
51470298 1280 if (ssh->deferred_len + len > ssh->deferred_size) {
1281 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1282 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1283 ssh->deferred_size,
1284 unsigned char);
39065bed 1285 }
ff3187f6 1286 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1287 ssh->deferred_len += len;
374330e2 1288}
1289
fb09bf1c 1290/*
39065bed 1291 * Construct a packet with the specified contents.
fb09bf1c 1292 */
ff3187f6 1293static struct Packet *construct_packet(Ssh ssh, int pkttype,
1294 va_list ap1, va_list ap2)
fb09bf1c 1295{
fb09bf1c 1296 unsigned char *p, *argp, argchar;
1297 unsigned long argint;
1298 int pktlen, argtype, arglen;
7cca0d81 1299 Bignum bn;
ff3187f6 1300 struct Packet *pkt;
fb09bf1c 1301
1302 pktlen = 0;
39065bed 1303 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1304 switch (argtype) {
1305 case PKT_INT:
39065bed 1306 (void) va_arg(ap1, int);
fb09bf1c 1307 pktlen += 4;
1308 break;
1309 case PKT_CHAR:
1ec39246 1310 (void) va_arg(ap1, int);
fb09bf1c 1311 pktlen++;
1312 break;
1313 case PKT_DATA:
39065bed 1314 (void) va_arg(ap1, unsigned char *);
1315 arglen = va_arg(ap1, int);
fb09bf1c 1316 pktlen += arglen;
1317 break;
1318 case PKT_STR:
39065bed 1319 argp = va_arg(ap1, unsigned char *);
d8baa528 1320 arglen = strlen((char *)argp);
fb09bf1c 1321 pktlen += 4 + arglen;
1322 break;
7cca0d81 1323 case PKT_BIGNUM:
39065bed 1324 bn = va_arg(ap1, Bignum);
32874aea 1325 pktlen += ssh1_bignum_length(bn);
7cca0d81 1326 break;
9a10ecf4 1327 case PKTT_PASSWORD:
1328 case PKTT_DATA:
1329 case PKTT_OTHER:
1330 /* ignore this pass */
1331 break;
fb09bf1c 1332 default:
1333 assert(0);
1334 }
1335 }
fb09bf1c 1336
ff3187f6 1337 pkt = s_wrpkt_start(pkttype, pktlen);
1338 p = pkt->body;
fb09bf1c 1339
39065bed 1340 while ((argtype = va_arg(ap2, int)) != PKT_END) {
ff3187f6 1341 int offset = p - pkt->body, len = 0;
fb09bf1c 1342 switch (argtype) {
9a10ecf4 1343 /* Actual fields in the packet */
fb09bf1c 1344 case PKT_INT:
39065bed 1345 argint = va_arg(ap2, int);
fb09bf1c 1346 PUT_32BIT(p, argint);
9a10ecf4 1347 len = 4;
fb09bf1c 1348 break;
1349 case PKT_CHAR:
1ec39246 1350 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1351 *p = argchar;
9a10ecf4 1352 len = 1;
fb09bf1c 1353 break;
1354 case PKT_DATA:
39065bed 1355 argp = va_arg(ap2, unsigned char *);
1356 arglen = va_arg(ap2, int);
fb09bf1c 1357 memcpy(p, argp, arglen);
9a10ecf4 1358 len = arglen;
fb09bf1c 1359 break;
1360 case PKT_STR:
39065bed 1361 argp = va_arg(ap2, unsigned char *);
d8baa528 1362 arglen = strlen((char *)argp);
fb09bf1c 1363 PUT_32BIT(p, arglen);
1364 memcpy(p + 4, argp, arglen);
9a10ecf4 1365 len = arglen + 4;
fb09bf1c 1366 break;
7cca0d81 1367 case PKT_BIGNUM:
39065bed 1368 bn = va_arg(ap2, Bignum);
9a10ecf4 1369 len = ssh1_write_bignum(p, bn);
1370 break;
1371 /* Tokens for modifications to packet logging */
1372 case PKTT_PASSWORD:
ff3187f6 1373 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1374 break;
1375 case PKTT_DATA:
ff3187f6 1376 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1377 break;
9a10ecf4 1378 case PKTT_OTHER:
ff3187f6 1379 end_log_omission(ssh, pkt);
9a10ecf4 1380 break;
1381 }
1382 p += len;
1383 /* Deal with logfile omission, if required. */
ff3187f6 1384 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1385 pkt->nblanks++;
1386 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1387 struct logblank_t);
1388 pkt->blanks[pkt->nblanks-1].offset = offset;
1389 pkt->blanks[pkt->nblanks-1].len = len;
1390 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
fb09bf1c 1391 }
1392 }
ff3187f6 1393
1394 return pkt;
39065bed 1395}
fb09bf1c 1396
51470298 1397static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1398{
ff3187f6 1399 struct Packet *pkt;
39065bed 1400 va_list ap1, ap2;
1401 va_start(ap1, pkttype);
1402 va_start(ap2, pkttype);
ff3187f6 1403 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1404 va_end(ap2);
1405 va_end(ap1);
1406 s_wrpkt(ssh, pkt);
1407 ssh_free_packet(pkt);
fb09bf1c 1408}
1409
51470298 1410static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1411{
ff3187f6 1412 struct Packet *pkt;
39065bed 1413 va_list ap1, ap2;
1414 va_start(ap1, pkttype);
1415 va_start(ap2, pkttype);
ff3187f6 1416 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1417 va_end(ap2);
1418 va_end(ap1);
1419 s_wrpkt_defer(ssh, pkt);
1420 ssh_free_packet(pkt);
39065bed 1421}
1422
32874aea 1423static int ssh_versioncmp(char *a, char *b)
1424{
9697bfd2 1425 char *ae, *be;
1426 unsigned long av, bv;
1427
43aa02a7 1428 av = strtoul(a, &ae, 10);
1429 bv = strtoul(b, &be, 10);
32874aea 1430 if (av != bv)
1431 return (av < bv ? -1 : +1);
1432 if (*ae == '.')
1433 ae++;
1434 if (*be == '.')
1435 be++;
43aa02a7 1436 av = strtoul(ae, &ae, 10);
1437 bv = strtoul(be, &be, 10);
32874aea 1438 if (av != bv)
1439 return (av < bv ? -1 : +1);
9697bfd2 1440 return 0;
1441}
1442
e5574168 1443/*
a92dd380 1444 * Utility routines for putting an SSH-protocol `string' and
1445 * `uint32' into a SHA state.
e5574168 1446 */
1447#include <stdio.h>
32874aea 1448static void sha_string(SHA_State * s, void *str, int len)
1449{
e5574168 1450 unsigned char lenblk[4];
e5574168 1451 PUT_32BIT(lenblk, len);
e5574168 1452 SHA_Bytes(s, lenblk, 4);
e5574168 1453 SHA_Bytes(s, str, len);
1454}
1455
32874aea 1456static void sha_uint32(SHA_State * s, unsigned i)
1457{
a92dd380 1458 unsigned char intblk[4];
1459 PUT_32BIT(intblk, i);
1460 SHA_Bytes(s, intblk, 4);
1461}
1462
7cca0d81 1463/*
1464 * SSH2 packet construction functions.
1465 */
ff3187f6 1466static void ssh2_pkt_ensure(struct Packet *pkt, int length)
32874aea 1467{
ff3187f6 1468 if (pkt->maxlen < length) {
1469 pkt->maxlen = length + 256;
1470 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
7cca0d81 1471 }
783415f8 1472}
ff3187f6 1473static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1474{
ff3187f6 1475 if (pkt->logmode != PKTLOG_EMIT) {
1476 pkt->nblanks++;
1477 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1478 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1479 pkt->blanks[pkt->nblanks-1].len = len;
1480 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1481 }
1482 pkt->length += len;
1483 ssh2_pkt_ensure(pkt, pkt->length);
1484 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1485}
ff3187f6 1486static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1487{
ff3187f6 1488 ssh2_pkt_adddata(pkt, &byte, 1);
7cca0d81 1489}
ff3187f6 1490static struct Packet *ssh2_pkt_init(int pkt_type)
32874aea 1491{
ff3187f6 1492 struct Packet *pkt = ssh_new_packet();
1493 pkt->length = 5;
1494 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1495 return pkt;
7cca0d81 1496}
ff3187f6 1497static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1498{
ff3187f6 1499 ssh2_pkt_adddata(pkt, &value, 1);
7cca0d81 1500}
ff3187f6 1501static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1502{
7cca0d81 1503 unsigned char x[4];
1504 PUT_32BIT(x, value);
ff3187f6 1505 ssh2_pkt_adddata(pkt, x, 4);
7cca0d81 1506}
ff3187f6 1507static void ssh2_pkt_addstring_start(struct Packet *pkt)
32874aea 1508{
ff3187f6 1509 ssh2_pkt_adduint32(pkt, 0);
1510 pkt->savedpos = pkt->length;
7cca0d81 1511}
ff3187f6 1512static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1513{
ff3187f6 1514 ssh2_pkt_adddata(pkt, data, strlen(data));
1515 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1516}
ff3187f6 1517static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1518{
ff3187f6 1519 ssh2_pkt_adddata(pkt, data, len);
1520 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1521}
ff3187f6 1522static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
32874aea 1523{
ff3187f6 1524 ssh2_pkt_addstring_start(pkt);
1525 ssh2_pkt_addstring_str(pkt, data);
7cca0d81 1526}
d8baa528 1527static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1528{
7cca0d81 1529 unsigned char *p;
32874aea 1530 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1531 p = snewn(n + 1, unsigned char);
7cca0d81 1532 if (!p)
32874aea 1533 fatalbox("out of memory");
7cca0d81 1534 p[0] = 0;
3709bfe9 1535 for (i = 1; i <= n; i++)
32874aea 1536 p[i] = bignum_byte(b, n - i);
7cca0d81 1537 i = 0;
32874aea 1538 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1539 i++;
1540 memmove(p, p + i, n + 1 - i);
1541 *len = n + 1 - i;
7cca0d81 1542 return p;
1543}
ff3187f6 1544static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1545{
7cca0d81 1546 unsigned char *p;
1547 int len;
1548 p = ssh2_mpint_fmt(b, &len);
ff3187f6 1549 ssh2_pkt_addstring_start(pkt);
1550 ssh2_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1551 sfree(p);
7cca0d81 1552}
b185170a 1553
1554/*
1555 * Construct an SSH2 final-form packet: compress it, encrypt it,
1556 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1557 * pkt->data. Total length is returned.
b185170a 1558 */
ff3187f6 1559static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1560{
7cca0d81 1561 int cipherblk, maclen, padding, i;
7cca0d81 1562
a8327734 1563 if (ssh->logctx)
ff3187f6 1564 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1565 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1566 pkt->data + 6, pkt->length - 6,
1567 pkt->nblanks, pkt->blanks);
1568 sfree(pkt->blanks); pkt->blanks = NULL;
1569 pkt->nblanks = 0;
00db133f 1570
7cca0d81 1571 /*
4ba9b64b 1572 * Compress packet payload.
1573 */
4ba9b64b 1574 {
1575 unsigned char *newpayload;
1576 int newlen;
51470298 1577 if (ssh->cscomp &&
ff3187f6 1578 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1579 pkt->length - 5,
51470298 1580 &newpayload, &newlen)) {
ff3187f6 1581 pkt->length = 5;
1582 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1583 sfree(newpayload);
4ba9b64b 1584 }
1585 }
1586
1587 /*
7cca0d81 1588 * Add padding. At least four bytes, and must also bring total
1589 * length (minus MAC) up to a multiple of the block size.
1590 */
51470298 1591 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1592 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1593 padding = 4;
32874aea 1594 padding +=
ff3187f6 1595 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
51470298 1596 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1597 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1598 pkt->data[4] = padding;
7cca0d81 1599 for (i = 0; i < padding; i++)
ff3187f6 1600 pkt->data[pkt->length + i] = random_byte();
1601 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1602 if (ssh->csmac)
ff3187f6 1603 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1604 pkt->length + padding,
51470298 1605 ssh->v2_outgoing_sequence);
1606 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1607
1608 if (ssh->cscipher)
371e569c 1609 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1610 pkt->data, pkt->length + padding);
51470298 1611
9442dd57 1612 pkt->encrypted_len = pkt->length + padding;
1613
ff3187f6 1614 /* Ready-to-send packet starts at pkt->data. We return length. */
1615 return pkt->length + padding + maclen;
b185170a 1616}
1617
1618/*
590f6a5f 1619 * Routines called from the main SSH code to send packets. There
1620 * are quite a few of these, because we have two separate
1621 * mechanisms for delaying the sending of packets:
1622 *
1623 * - In order to send an IGNORE message and a password message in
1624 * a single fixed-length blob, we require the ability to
1625 * concatenate the encrypted forms of those two packets _into_ a
1626 * single blob and then pass it to our <network.h> transport
1627 * layer in one go. Hence, there's a deferment mechanism which
1628 * works after packet encryption.
1629 *
1630 * - In order to avoid sending any connection-layer messages
1631 * during repeat key exchange, we have to queue up any such
1632 * outgoing messages _before_ they are encrypted (and in
1633 * particular before they're allocated sequence numbers), and
1634 * then send them once we've finished.
1635 *
1636 * I call these mechanisms `defer' and `queue' respectively, so as
1637 * to distinguish them reasonably easily.
1638 *
1639 * The functions send_noqueue() and defer_noqueue() free the packet
1640 * structure they are passed. Every outgoing packet goes through
1641 * precisely one of these functions in its life; packets passed to
1642 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1643 * these or get queued, and then when the queue is later emptied
1644 * the packets are all passed to defer_noqueue().
b185170a 1645 */
590f6a5f 1646
1647/*
1648 * Send an SSH2 packet immediately, without queuing or deferring.
1649 */
1650static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1651{
5471d09a 1652 int len;
1653 int backlog;
ff3187f6 1654 len = ssh2_pkt_construct(ssh, pkt);
1655 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1656 if (backlog > SSH_MAX_BACKLOG)
51470298 1657 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1658
1659 ssh->outgoing_data_size += pkt->encrypted_len;
1660 if (!ssh->kex_in_progress &&
1661 ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY)
1662 do_ssh2_transport(ssh, "Initiating key re-exchange "
1663 "(too much data sent)", -1, NULL);
1664
ff3187f6 1665 ssh_free_packet(pkt);
b185170a 1666}
1667
1668/*
590f6a5f 1669 * Defer an SSH2 packet.
b185170a 1670 */
590f6a5f 1671static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1672{
ff3187f6 1673 int len = ssh2_pkt_construct(ssh, pkt);
51470298 1674 if (ssh->deferred_len + len > ssh->deferred_size) {
1675 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1676 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1677 ssh->deferred_size,
1678 unsigned char);
b185170a 1679 }
ff3187f6 1680 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1681 ssh->deferred_len += len;
9442dd57 1682 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1683 ssh_free_packet(pkt);
b185170a 1684}
1685
1686/*
590f6a5f 1687 * Queue an SSH2 packet.
1688 */
1689static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1690{
1691 assert(ssh->queueing);
1692
1693 if (ssh->queuelen >= ssh->queuesize) {
1694 ssh->queuesize = ssh->queuelen + 32;
1695 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1696 }
1697
1698 ssh->queue[ssh->queuelen++] = pkt;
1699}
1700
1701/*
1702 * Either queue or send a packet, depending on whether queueing is
1703 * set.
1704 */
1705static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1706{
1707 if (ssh->queueing)
1708 ssh2_pkt_queue(ssh, pkt);
1709 else
1710 ssh2_pkt_send_noqueue(ssh, pkt);
1711}
1712
1713/*
1714 * Either queue or defer a packet, depending on whether queueing is
1715 * set.
1716 */
1717static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1718{
1719 if (ssh->queueing)
1720 ssh2_pkt_queue(ssh, pkt);
1721 else
1722 ssh2_pkt_defer_noqueue(ssh, pkt);
1723}
1724
1725/*
b185170a 1726 * Send the whole deferred data block constructed by
39065bed 1727 * ssh2_pkt_defer() or SSH1's defer_packet().
590f6a5f 1728 *
1729 * The expected use of the defer mechanism is that you call
1730 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1731 * not currently queueing, this simply sets up deferred_send_data
1732 * and then sends it. If we _are_ currently queueing, the calls to
1733 * ssh2_pkt_defer() put the deferred packets on to the queue
1734 * instead, and therefore ssh_pkt_defersend() has no deferred data
1735 * to send. Hence, there's no need to make it conditional on
1736 * ssh->queueing.
b185170a 1737 */
51470298 1738static void ssh_pkt_defersend(Ssh ssh)
32874aea 1739{
5471d09a 1740 int backlog;
d8baa528 1741 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1742 ssh->deferred_len);
51470298 1743 ssh->deferred_len = ssh->deferred_size = 0;
1744 sfree(ssh->deferred_send_data);
1745 ssh->deferred_send_data = NULL;
5471d09a 1746 if (backlog > SSH_MAX_BACKLOG)
51470298 1747 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1748
1749 ssh->outgoing_data_size += ssh->deferred_data_size;
1750 if (!ssh->kex_in_progress &&
1751 ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY)
1752 do_ssh2_transport(ssh, "Initiating key re-exchange "
1753 "(too much data sent)", -1, NULL);
1754 ssh->deferred_data_size = 0;
7cca0d81 1755}
1756
590f6a5f 1757/*
1758 * Send all queued SSH2 packets. We send them by means of
1759 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1760 * packets that needed to be lumped together.
1761 */
1762static void ssh2_pkt_queuesend(Ssh ssh)
1763{
1764 int i;
1765
1766 assert(!ssh->queueing);
1767
1768 for (i = 0; i < ssh->queuelen; i++)
1769 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1770 ssh->queuelen = 0;
1771
1772 ssh_pkt_defersend(ssh);
1773}
1774
7cca0d81 1775#if 0
32874aea 1776void bndebug(char *string, Bignum b)
1777{
7cca0d81 1778 unsigned char *p;
1779 int i, len;
1780 p = ssh2_mpint_fmt(b, &len);
1781 debug(("%s", string));
1782 for (i = 0; i < len; i++)
32874aea 1783 debug((" %02x", p[i]));
765c4200 1784 debug(("\n"));
dcbde236 1785 sfree(p);
7cca0d81 1786}
1787#endif
1788
32874aea 1789static void sha_mpint(SHA_State * s, Bignum b)
1790{
7cca0d81 1791 unsigned char *p;
1792 int len;
1793 p = ssh2_mpint_fmt(b, &len);
1794 sha_string(s, p, len);
dcbde236 1795 sfree(p);
7cca0d81 1796}
1797
1798/*
0016d70b 1799 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1800 */
ff3187f6 1801static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1802{
7cca0d81 1803 unsigned long value;
ff3187f6 1804 if (pkt->length - pkt->savedpos < 4)
32874aea 1805 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1806 value = GET_32BIT(pkt->body + pkt->savedpos);
1807 pkt->savedpos += 4;
7cca0d81 1808 return value;
1809}
ff3187f6 1810static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1811{
65a22376 1812 unsigned long value;
ff3187f6 1813 if (pkt->length - pkt->savedpos < 1)
32874aea 1814 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1815 value = pkt->body[pkt->savedpos] != 0;
1816 pkt->savedpos++;
65a22376 1817 return value;
1818}
ff3187f6 1819static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 1820{
57356d63 1821 int len;
7cca0d81 1822 *p = NULL;
45068b27 1823 *length = 0;
ff3187f6 1824 if (pkt->length - pkt->savedpos < 4)
32874aea 1825 return;
ff3187f6 1826 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 1827 if (len < 0)
1828 return;
1829 *length = len;
ff3187f6 1830 pkt->savedpos += 4;
1831 if (pkt->length - pkt->savedpos < *length)
32874aea 1832 return;
ff3187f6 1833 *p = (char *)(pkt->body + pkt->savedpos);
1834 pkt->savedpos += *length;
7cca0d81 1835}
ff3187f6 1836static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 1837{
ff3187f6 1838 if (pkt->length - pkt->savedpos < length)
0016d70b 1839 return NULL;
ff3187f6 1840 pkt->savedpos += length;
1841 return pkt->body + (pkt->savedpos - length);
0016d70b 1842}
ff3187f6 1843static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 1844 unsigned char **keystr)
1845{
1846 int j;
1847
ff3187f6 1848 j = makekey(pkt->body + pkt->savedpos,
1849 pkt->length - pkt->savedpos,
0016d70b 1850 key, keystr, 0);
1851
1852 if (j < 0)
1853 return FALSE;
1854
ff3187f6 1855 pkt->savedpos += j;
1856 assert(pkt->savedpos < pkt->length);
0016d70b 1857
1858 return TRUE;
1859}
ff3187f6 1860static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 1861{
1862 int j;
1863 Bignum b;
1864
ff3187f6 1865 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1866 pkt->length - pkt->savedpos, &b);
0016d70b 1867
1868 if (j < 0)
1869 return NULL;
1870
ff3187f6 1871 pkt->savedpos += j;
0016d70b 1872 return b;
1873}
ff3187f6 1874static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 1875{
7cca0d81 1876 char *p;
3709bfe9 1877 int length;
7cca0d81 1878 Bignum b;
1879
ff3187f6 1880 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 1881 if (!p)
32874aea 1882 return NULL;
ff3187f6 1883 if (p[0] & 0x80)
32874aea 1884 return NULL;
d8baa528 1885 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1886 return b;
1887}
1888
7d503c31 1889/*
1dd353b5 1890 * Helper function to add an SSH2 signature blob to a packet.
1891 * Expects to be shown the public key blob as well as the signature
1892 * blob. Normally works just like ssh2_pkt_addstring, but will
1893 * fiddle with the signature packet if necessary for
1894 * BUG_SSH2_RSA_PADDING.
1895 */
ff3187f6 1896static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1897 void *pkblob_v, int pkblob_len,
1dd353b5 1898 void *sigblob_v, int sigblob_len)
1899{
1900 unsigned char *pkblob = (unsigned char *)pkblob_v;
1901 unsigned char *sigblob = (unsigned char *)sigblob_v;
1902
1903 /* dmemdump(pkblob, pkblob_len); */
1904 /* dmemdump(sigblob, sigblob_len); */
1905
1906 /*
1907 * See if this is in fact an ssh-rsa signature and a buggy
1908 * server; otherwise we can just do this the easy way.
1909 */
51470298 1910 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1911 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1912 int pos, len, siglen;
1913
1914 /*
1915 * Find the byte length of the modulus.
1916 */
1917
1918 pos = 4+7; /* skip over "ssh-rsa" */
1919 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1920 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1921 pos += 4; /* find modulus itself */
1922 while (len > 0 && pkblob[pos] == 0)
1923 len--, pos++;
1924 /* debug(("modulus length is %d\n", len)); */
1925
1926 /*
1927 * Now find the signature integer.
1928 */
1929 pos = 4+7; /* skip over "ssh-rsa" */
1930 siglen = GET_32BIT(sigblob+pos);
1931 /* debug(("signature length is %d\n", siglen)); */
1932
1933 if (len != siglen) {
1934 unsigned char newlen[4];
ff3187f6 1935 ssh2_pkt_addstring_start(pkt);
1936 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 1937 /* dmemdump(sigblob, pos); */
1938 pos += 4; /* point to start of actual sig */
1939 PUT_32BIT(newlen, len);
ff3187f6 1940 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 1941 /* dmemdump(newlen, 4); */
1942 newlen[0] = 0;
1943 while (len-- > siglen) {
ff3187f6 1944 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 1945 /* dmemdump(newlen, 1); */
1946 }
ff3187f6 1947 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 1948 /* dmemdump(sigblob+pos, siglen); */
1949 return;
1950 }
1951
1952 /* Otherwise fall through and do it the easy way. */
1953 }
1954
ff3187f6 1955 ssh2_pkt_addstring_start(pkt);
1956 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 1957}
1958
1959/*
7d503c31 1960 * Examine the remote side's version string and compare it against
1961 * a list of known buggy implementations.
1962 */
51470298 1963static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1964{
1965 char *imp; /* pointer to implementation part */
7d503c31 1966 imp = vstring;
1967 imp += strcspn(imp, "-");
bd358db1 1968 if (*imp) imp++;
7d503c31 1969 imp += strcspn(imp, "-");
bd358db1 1970 if (*imp) imp++;
7d503c31 1971
51470298 1972 ssh->remote_bugs = 0;
7d503c31 1973
5ecd7ad0 1974 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1975 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 1976 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1977 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 1978 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 1979 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 1980 /*
1981 * These versions don't support SSH1_MSG_IGNORE, so we have
1982 * to use a different defence against password length
1983 * sniffing.
1984 */
51470298 1985 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1986 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1987 }
1988
5ecd7ad0 1989 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1990 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 1991 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 1992 /*
1993 * These versions need a plain password sent; they can't
1994 * handle having a null and a random length of data after
1995 * the password.
1996 */
51470298 1997 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1998 logevent("We believe remote version needs a plain SSH1 password");
1999 }
2000
5ecd7ad0 2001 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2002 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2003 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2004 /*
2005 * These versions apparently have no clue whatever about
2006 * RSA authentication and will panic and die if they see
2007 * an AUTH_RSA message.
2008 */
51470298 2009 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 2010 logevent("We believe remote version can't handle RSA authentication");
2011 }
2012
5ecd7ad0 2013 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2014 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2015 !wc_match("* VShell", imp) &&
831301f6 2016 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2017 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2018 wc_match("2.1 *", imp)))) {
32874aea 2019 /*
2020 * These versions have the HMAC bug.
2021 */
51470298 2022 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2023 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2024 }
1dd353b5 2025
5ecd7ad0 2026 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2027 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2028 !wc_match("* VShell", imp) &&
2856a1b9 2029 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2030 /*
2031 * These versions have the key-derivation bug (failing to
2032 * include the literal shared secret in the hashes that
2033 * generate the keys).
2034 */
51470298 2035 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2036 logevent("We believe remote version has SSH2 key-derivation bug");
2037 }
2038
5ecd7ad0 2039 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2040 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2041 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2042 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2043 /*
2044 * These versions have the SSH2 RSA padding bug.
2045 */
51470298 2046 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2047 logevent("We believe remote version has SSH2 RSA padding bug");
2048 }
8e975795 2049
dda87a28 2050 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2051 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2052 wc_match("OpenSSH_2.[0-2]*", imp))) {
2053 /*
2054 * These versions have the SSH2 session-ID bug in
2055 * public-key authentication.
2056 */
2057 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2058 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2059 }
2060
5ecd7ad0 2061 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
8e975795 2062 /*
831301f6 2063 * User specified the SSH2 DH GEX bug.
8e975795 2064 */
51470298 2065 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 2066 logevent("We believe remote version has SSH2 DH group exchange bug");
2067 }
7d503c31 2068}
2069
d38d6a1f 2070/*
2071 * The `software version' part of an SSH version string is required
2072 * to contain no spaces or minus signs.
2073 */
2074static void ssh_fix_verstring(char *str)
2075{
2076 /* Eat "SSH-<protoversion>-". */
2077 assert(*str == 'S'); str++;
2078 assert(*str == 'S'); str++;
2079 assert(*str == 'H'); str++;
2080 assert(*str == '-'); str++;
2081 while (*str && *str != '-') str++;
2082 assert(*str == '-'); str++;
2083
2084 /* Convert minus signs and spaces in the remaining string into
2085 * underscores. */
2086 while (*str) {
2087 if (*str == '-' || *str == ' ')
2088 *str = '_';
2089 str++;
2090 }
2091}
2092
51470298 2093static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2094{
51470298 2095 struct do_ssh_init_state {
2096 int vslen;
2097 char version[10];
2098 char *vstring;
2099 int vstrsize;
2100 int i;
2101 int proto1, proto2;
2102 };
2103 crState(do_ssh_init_state);
374330e2 2104
51470298 2105 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2106
2107 /* Search for the string "SSH-" in the input. */
51470298 2108 s->i = 0;
8df7a775 2109 while (1) {
2110 static const int transS[] = { 1, 2, 2, 1 };
2111 static const int transH[] = { 0, 0, 3, 0 };
2112 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2113 if (c == 'S')
51470298 2114 s->i = transS[s->i];
32874aea 2115 else if (c == 'H')
51470298 2116 s->i = transH[s->i];
32874aea 2117 else if (c == '-')
51470298 2118 s->i = transminus[s->i];
32874aea 2119 else
51470298 2120 s->i = 0;
2121 if (s->i < 0)
8df7a775 2122 break;
2123 crReturn(1); /* get another character */
374330e2 2124 }
8df7a775 2125
51470298 2126 s->vstrsize = 16;
3d88e64d 2127 s->vstring = snewn(s->vstrsize, char);
51470298 2128 strcpy(s->vstring, "SSH-");
2129 s->vslen = 4;
2130 s->i = 0;
374330e2 2131 while (1) {
8df7a775 2132 crReturn(1); /* get another char */
51470298 2133 if (s->vslen >= s->vstrsize - 1) {
2134 s->vstrsize += 16;
3d88e64d 2135 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2136 }
51470298 2137 s->vstring[s->vslen++] = c;
2138 if (s->i >= 0) {
374330e2 2139 if (c == '-') {
51470298 2140 s->version[s->i] = '\0';
2141 s->i = -1;
2142 } else if (s->i < sizeof(s->version) - 1)
2143 s->version[s->i++] = c;
c4ffc4d0 2144 } else if (c == '\012')
374330e2 2145 break;
2146 }
2147
51470298 2148 ssh->agentfwd_enabled = FALSE;
2149 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2150
51470298 2151 s->vstring[s->vslen] = 0;
2152 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
2153 {
2154 char *vlog;
3d88e64d 2155 vlog = snewn(20 + s->vslen, char);
51470298 2156 sprintf(vlog, "Server version: %s", s->vstring);
2157 logevent(vlog);
2158 sfree(vlog);
2159 }
2160 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2161
adf799dd 2162 /*
38d228a2 2163 * Decide which SSH protocol version to support.
adf799dd 2164 */
38d228a2 2165
2166 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2167 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2168 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2169 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2170
86916870 2171 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2172 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2173 crStop(0);
38d228a2 2174 }
86916870 2175 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2176 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2177 crStop(0);
38d228a2 2178 }
2179
d38d6a1f 2180 {
2181 char *verstring;
2182
2183 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2184 /*
2185 * Construct a v2 version string.
2186 */
2187 verstring = dupprintf("SSH-2.0-%s\n", sshver);
2188 ssh->version = 2;
2189 } else {
2190 /*
2191 * Construct a v1 version string.
2192 */
2193 verstring = dupprintf("SSH-%s-%s\n",
2194 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2195 s->version : "1.5"),
2196 sshver);
2197 ssh->version = 1;
2198 }
2199
2200 ssh_fix_verstring(verstring);
2201
2202 if (ssh->version == 2) {
2203 /*
2204 * Hash our version string and their version string.
2205 */
2206 SHA_Init(&ssh->exhashbase);
2207 sha_string(&ssh->exhashbase, verstring, strlen(verstring)-1);
2208 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
2209
2210 /*
2211 * Initialise SSHv2 protocol.
2212 */
2213 ssh->protocol = ssh2_protocol;
2214 ssh2_protocol_setup(ssh);
2215 ssh->s_rdpkt = ssh2_rdpkt;
2216 } else {
2217 /*
2218 * Initialise SSHv1 protocol.
2219 */
2220 ssh->protocol = ssh1_protocol;
2221 ssh1_protocol_setup(ssh);
2222 ssh->s_rdpkt = ssh1_rdpkt;
2223 }
2224 logeventf(ssh, "We claim version: %.*s",
2225 strlen(verstring)-1, verstring);
51470298 2226 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2227 sfree(verstring);
e5574168 2228 }
d38d6a1f 2229
2230 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2231
125105d1 2232 update_specials_menu(ssh->frontend);
51470298 2233 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2234 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2235
51470298 2236 sfree(s->vstring);
50526e47 2237
8df7a775 2238 crFinish(0);
2239}
2240
51470298 2241static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2242{
51470298 2243 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2244
2245 /*
2246 * To begin with, feed the characters one by one to the
2247 * protocol initialisation / selection function do_ssh_init().
2248 * When that returns 0, we're done with the initial greeting
2249 * exchange and can move on to packet discipline.
2250 */
2251 while (1) {
51470298 2252 int ret; /* need not be kept across crReturn */
8df7a775 2253 if (datalen == 0)
2254 crReturnV; /* more data please */
51470298 2255 ret = do_ssh_init(ssh, *data);
32874aea 2256 data++;
2257 datalen--;
8df7a775 2258 if (ret == 0)
2259 break;
2260 }
2261
2262 /*
2263 * We emerge from that loop when the initial negotiation is
2264 * over and we have selected an s_rdpkt function. Now pass
2265 * everything to s_rdpkt, and then pass the resulting packets
2266 * to the proper protocol handler.
2267 */
2268 if (datalen == 0)
2269 crReturnV;
2270 while (1) {
2271 while (datalen > 0) {
ff3187f6 2272 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2273 if (pktin) {
2274 ssh->protocol(ssh, NULL, 0, pktin);
2275 ssh_free_packet(pktin);
8df7a775 2276 }
ff3187f6 2277 if (ssh->state == SSH_STATE_CLOSED)
2278 return;
8df7a775 2279 }
2280 crReturnV;
2281 }
2282 crFinishV;
2283}
2284
36f94d1f 2285static void ssh_do_close(Ssh ssh)
32874aea 2286{
36f94d1f 2287 int i;
2288 struct ssh_channel *c;
2289
51470298 2290 ssh->state = SSH_STATE_CLOSED;
2291 if (ssh->s) {
2292 sk_close(ssh->s);
2293 ssh->s = NULL;
39934deb 2294 notify_remote_exit(ssh->frontend);
f3ab576e 2295 }
36f94d1f 2296 /*
2297 * Now we must shut down any port and X forwardings going
2298 * through this connection.
2299 */
74a98066 2300 if (ssh->channels) {
2301 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2302 switch (c->type) {
2303 case CHAN_X11:
2304 x11_close(c->u.x11.s);
2305 break;
2306 case CHAN_SOCKDATA:
2307 pfd_close(c->u.pfd.s);
2308 break;
2309 }
2310 del234(ssh->channels, c);
2311 if (ssh->version == 2)
2312 bufchain_clear(&c->v.v2.outbuffer);
2313 sfree(c);
36f94d1f 2314 }
36f94d1f 2315 }
2316}
2317
cbe2d68f 2318static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2319 int calling_back)
2320{
2321 Ssh ssh = (Ssh) plug;
2322 ssh_do_close(ssh);
7e78000d 2323 if (error_msg) {
32874aea 2324 /* A socket error has occurred. */
247308b5 2325 logevent(error_msg);
971bcc0a 2326 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2327 } else {
2328 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2329 }
7e78000d 2330 return 0;
2331}
2332
32874aea 2333static int ssh_receive(Plug plug, int urgent, char *data, int len)
2334{
51470298 2335 Ssh ssh = (Ssh) plug;
d8baa528 2336 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2337 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2338 ssh_do_close(ssh);
32874aea 2339 return 0;
3257deae 2340 }
fef97f43 2341 return 1;
374330e2 2342}
2343
5471d09a 2344static void ssh_sent(Plug plug, int bufsize)
2345{
51470298 2346 Ssh ssh = (Ssh) plug;
5471d09a 2347 /*
2348 * If the send backlog on the SSH socket itself clears, we
2349 * should unthrottle the whole world if it was throttled.
2350 */
2351 if (bufsize < SSH_MAX_BACKLOG)
51470298 2352 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2353}
2354
fb09bf1c 2355/*
8df7a775 2356 * Connect to specified host and port.
2357 * Returns an error message, or NULL on success.
6e1ebb76 2358 * Also places the canonical host name into `realhost'. It must be
2359 * freed by the caller.
8df7a775 2360 */
cbe2d68f 2361static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2362 char **realhost, int nodelay, int keepalive)
8df7a775 2363{
51470298 2364 static const struct plug_function_table fn_table = {
7e78000d 2365 ssh_closing,
5471d09a 2366 ssh_receive,
2367 ssh_sent,
2368 NULL
51470298 2369 };
7e78000d 2370
8df7a775 2371 SockAddr addr;
cbe2d68f 2372 const char *err;
8df7a775 2373
3d88e64d 2374 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2375 if (!ssh->savedhost)
8df7a775 2376 fatalbox("Out of memory");
51470298 2377 strcpy(ssh->savedhost, host);
8df7a775 2378
2379 if (port < 0)
2380 port = 22; /* default ssh port */
51470298 2381 ssh->savedport = port;
8df7a775 2382
2383 /*
2384 * Try to find host.
2385 */
57356d63 2386 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2387 addr = name_lookup(host, port, realhost, &ssh->cfg);
170c1e6e 2388 if ((err = sk_addr_error(addr)) != NULL) {
2389 sk_addr_free(addr);
8df7a775 2390 return err;
170c1e6e 2391 }
8df7a775 2392
8df7a775 2393 /*
2394 * Open socket.
2395 */
3ad9d396 2396 {
57356d63 2397 char addrbuf[100];
3ad9d396 2398 sk_getaddr(addr, addrbuf, 100);
57356d63 2399 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2400 }
51470298 2401 ssh->fn = &fn_table;
e8fa8f62 2402 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2403 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2404 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2405 ssh->s = NULL;
39934deb 2406 notify_remote_exit(ssh->frontend);
8df7a775 2407 return err;
67c4ba2e 2408 }
8df7a775 2409
8df7a775 2410 return NULL;
2411}
2412
2413/*
5471d09a 2414 * Throttle or unthrottle the SSH connection.
2415 */
51470298 2416static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2417{
51470298 2418 int old_count = ssh->v1_throttle_count;
2419 ssh->v1_throttle_count += adjust;
2420 assert(ssh->v1_throttle_count >= 0);
2421 if (ssh->v1_throttle_count && !old_count) {
2422 sk_set_frozen(ssh->s, 1);
2423 } else if (!ssh->v1_throttle_count && old_count) {
2424 sk_set_frozen(ssh->s, 0);
5471d09a 2425 }
2426}
2427
2428/*
2429 * Throttle or unthrottle _all_ local data streams (for when sends
2430 * on the SSH connection itself back up).
2431 */
51470298 2432static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2433{
2434 int i;
2435 struct ssh_channel *c;
2436
51470298 2437 if (enable == ssh->throttled_all)
5471d09a 2438 return;
51470298 2439 ssh->throttled_all = enable;
2440 ssh->overall_bufsize = bufsize;
2441 if (!ssh->channels)
5471d09a 2442 return;
51470298 2443 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2444 switch (c->type) {
2445 case CHAN_MAINSESSION:
2446 /*
2447 * This is treated separately, outside the switch.
2448 */
2449 break;
2450 case CHAN_X11:
2451 x11_override_throttle(c->u.x11.s, enable);
2452 break;
2453 case CHAN_AGENT:
2454 /* Agent channels require no buffer management. */
2455 break;
2456 case CHAN_SOCKDATA:
36f94d1f 2457 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2458 break;
2459 }
2460 }
2461}
2462
2463/*
51470298 2464 * Username and password input, abstracted off into routines
2465 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2466 */
0405e71f 2467
2468/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2469static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2470{
51470298 2471 ssh->userpass_input_buffer = buffer;
2472 ssh->userpass_input_buflen = buflen;
2473 ssh->userpass_input_bufpos = 0;
2474 ssh->userpass_input_echo = echo;
0405e71f 2475}
2476
2477/*
2478 * Process some terminal data in the course of username/password
2479 * input. Returns >0 for success (line of input returned in
2480 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2481 * for inconclusive (keep waiting for more input please).
2482 */
ae9ae89f 2483static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2484{
2485 char c;
2486
2487 while (inlen--) {
2488 switch (c = *in++) {
2489 case 10:
2490 case 13:
51470298 2491 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2492 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2493 return +1;
2494 break;
2495 case 8:
2496 case 127:
51470298 2497 if (ssh->userpass_input_bufpos > 0) {
2498 if (ssh->userpass_input_echo)
2499 c_write_str(ssh, "\b \b");
2500 ssh->userpass_input_bufpos--;
0405e71f 2501 }
2502 break;
2503 case 21:
2504 case 27:
51470298 2505 while (ssh->userpass_input_bufpos > 0) {
2506 if (ssh->userpass_input_echo)
2507 c_write_str(ssh, "\b \b");
2508 ssh->userpass_input_bufpos--;
0405e71f 2509 }
2510 break;
2511 case 3:
2512 case 4:
2513 return -1;
2514 break;
2515 default:
4692a14a 2516 /*
2517 * This simplistic check for printability is disabled
2518 * when we're doing password input, because some people
2519 * have control characters in their passwords.o
2520 */
2521 if ((!ssh->userpass_input_echo ||
2522 (c >= ' ' && c <= '~') ||
0405e71f 2523 ((unsigned char) c >= 160))
51470298 2524 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2525 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2526 if (ssh->userpass_input_echo)
2527 c_write(ssh, &c, 1);
0405e71f 2528 }
2529 break;
2530 }
2531 }
2532 return 0;
2533}
2534
f11d78f2 2535static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2536{
2537 Ssh ssh = (Ssh) sshv;
2538
2539 ssh->agent_response = reply;
2540 ssh->agent_response_len = replylen;
2541
2542 if (ssh->version == 1)
ff3187f6 2543 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2544 else
ff3187f6 2545 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2546}
2547
f11d78f2 2548static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2549{
2550 struct ssh_channel *c = (struct ssh_channel *)cv;
2551 Ssh ssh = c->ssh;
2552 void *sentreply = reply;
2553
2554 if (!sentreply) {
2555 /* Fake SSH_AGENT_FAILURE. */
2556 sentreply = "\0\0\0\1\5";
2557 replylen = 5;
2558 }
2559 if (ssh->version == 2) {
2560 ssh2_add_channel_data(c, sentreply, replylen);
2561 ssh2_try_send(c);
2562 } else {
2563 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2564 PKT_INT, c->remoteid,
9a10ecf4 2565 PKTT_DATA,
839f10db 2566 PKT_INT, replylen,
2567 PKT_DATA, sentreply, replylen,
9a10ecf4 2568 PKTT_OTHER,
839f10db 2569 PKT_END);
2570 }
2571 if (reply)
2572 sfree(reply);
2573}
2574
0405e71f 2575/*
fb09bf1c 2576 * Handle the key exchange and user authentication phases.
2577 */
ff3187f6 2578static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2579 struct Packet *pktin)
fb09bf1c 2580{
0016d70b 2581 int i, j, ret;
2582 unsigned char cookie[8], *ptr;
374330e2 2583 struct RSAKey servkey, hostkey;
2584 struct MD5Context md5c;
51470298 2585 struct do_ssh1_login_state {
2586 int len;
2587 unsigned char *rsabuf, *keystr1, *keystr2;
2588 unsigned long supported_ciphers_mask, supported_auths_mask;
2589 int tried_publickey, tried_agent;
2590 int tis_auth_refused, ccard_auth_refused;
2591 unsigned char session_id[16];
2592 int cipher_type;
2593 char username[100];
2594 void *publickey_blob;
2595 int publickey_bloblen;
2596 char password[100];
2597 char prompt[200];
2598 int pos;
2599 char c;
2600 int pwpkt_type;
2601 unsigned char request[5], *response, *p;
2602 int responselen;
2603 int keyi, nkeys;
2604 int authed;
2605 struct RSAKey key;
2606 Bignum challenge;
2607 char *commentp;
2608 int commentlen;
2609 };
2610 crState(do_ssh1_login_state);
2611
2612 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2613
ff3187f6 2614 if (!pktin)
2615 crWaitUntil(pktin);
374330e2 2616
ff3187f6 2617 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2618 bombout(("Public key packet not received"));
7ffdbc1a 2619 crStop(0);
8d5de777 2620 }
374330e2 2621
c5e9c988 2622 logevent("Received public keys");
374330e2 2623
ff3187f6 2624 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2625 if (!ptr) {
2626 bombout(("SSH1 public key packet stopped before random cookie"));
2627 crStop(0);
2628 }
2629 memcpy(cookie, ptr, 8);
374330e2 2630
ff3187f6 2631 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2632 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2633 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2634 crStop(0);
2635 }
374330e2 2636
c5e9c988 2637 /*
1c2a93c4 2638 * Log the host key fingerprint.
c5e9c988 2639 */
c5e9c988 2640 {
2641 char logmsg[80];
1c2a93c4 2642 logevent("Host key fingerprint is:");
c5e9c988 2643 strcpy(logmsg, " ");
32874aea 2644 hostkey.comment = NULL;
2645 rsa_fingerprint(logmsg + strlen(logmsg),
2646 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2647 logevent(logmsg);
2648 }
2649
ff3187f6 2650 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2651 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2652 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2653
51470298 2654 ssh->v1_local_protoflags =
2655 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2656 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2657
c5e9c988 2658 MD5Init(&md5c);
51470298 2659 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2660 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2661 MD5Update(&md5c, cookie, 8);
51470298 2662 MD5Final(s->session_id, &md5c);
374330e2 2663
32874aea 2664 for (i = 0; i < 32; i++)
51470298 2665 ssh->session_key[i] = random_byte();
374330e2 2666
0016d70b 2667 /*
2668 * Verify that the `bits' and `bytes' parameters match.
2669 */
2670 if (hostkey.bits > hostkey.bytes * 8 ||
2671 servkey.bits > servkey.bytes * 8) {
2672 bombout(("SSH1 public keys were badly formatted"));
2673 crStop(0);
2674 }
2675
51470298 2676 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2677
3d88e64d 2678 s->rsabuf = snewn(s->len, unsigned char);
51470298 2679 if (!s->rsabuf)
374330e2 2680 fatalbox("Out of memory");
2681
89ee5268 2682 /*
2683 * Verify the host key.
2684 */
2685 {
32874aea 2686 /*
2687 * First format the key into a string.
2688 */
2689 int len = rsastr_len(&hostkey);
2690 char fingerprint[100];
3d88e64d 2691 char *keystr = snewn(len, char);
32874aea 2692 if (!keystr)
2693 fatalbox("Out of memory");
2694 rsastr_fmt(keystr, &hostkey);
2695 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2696 verify_ssh_host_key(ssh->frontend,
2697 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2698 fingerprint);
2699 sfree(keystr);
2700 }
2701
2702 for (i = 0; i < 32; i++) {
51470298 2703 s->rsabuf[i] = ssh->session_key[i];
374330e2 2704 if (i < 16)
51470298 2705 s->rsabuf[i] ^= s->session_id[i];
374330e2 2706 }
2707
2708 if (hostkey.bytes > servkey.bytes) {
0016d70b 2709 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2710 if (ret)
2711 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2712 } else {
0016d70b 2713 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2714 if (ret)
2715 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2716 }
2717 if (!ret) {
2718 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2719 crStop(0);
374330e2 2720 }
2721
c5e9c988 2722 logevent("Encrypted session key");
2723
ca20bfcf 2724 {
2725 int cipher_chosen = 0, warn = 0;
2726 char *cipher_string = NULL;
51470298 2727 int i;
ca20bfcf 2728 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2729 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2730 if (next_cipher == CIPHER_WARN) {
2731 /* If/when we choose a cipher, warn about it */
2732 warn = 1;
2733 } else if (next_cipher == CIPHER_AES) {
2734 /* XXX Probably don't need to mention this. */
2735 logevent("AES not supported in SSH1, skipping");
2736 } else {
2737 switch (next_cipher) {
51470298 2738 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2739 cipher_string = "3DES"; break;
51470298 2740 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2741 cipher_string = "Blowfish"; break;
51470298 2742 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2743 cipher_string = "single-DES"; break;
2744 }
51470298 2745 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2746 cipher_chosen = 1;
2747 }
2748 }
2749 if (!cipher_chosen) {
51470298 2750 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2751 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2752 "supporting 3DES encryption"));
2753 else
2754 /* shouldn't happen */
6b5cf8b4 2755 bombout(("No supported ciphers found"));
7ffdbc1a 2756 crStop(0);
a99a05c0 2757 }
ca20bfcf 2758
2759 /* Warn about chosen cipher if necessary. */
2760 if (warn)
a8327734 2761 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2762 }
ca20bfcf 2763
51470298 2764 switch (s->cipher_type) {
32874aea 2765 case SSH_CIPHER_3DES:
2766 logevent("Using 3DES encryption");
2767 break;
2768 case SSH_CIPHER_DES:
2769 logevent("Using single-DES encryption");
2770 break;
2771 case SSH_CIPHER_BLOWFISH:
2772 logevent("Using Blowfish encryption");
2773 break;
c5e9c988 2774 }
bea1ef5f 2775
51470298 2776 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2777 PKT_CHAR, s->cipher_type,
32874aea 2778 PKT_DATA, cookie, 8,
51470298 2779 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2780 PKT_DATA, s->rsabuf, s->len,
2781 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2782
c5e9c988 2783 logevent("Trying to enable encryption...");
374330e2 2784
51470298 2785 sfree(s->rsabuf);
374330e2 2786
51470298 2787 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2788 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2789 &ssh_3des);
371e569c 2790 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2791 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2792 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2793
0183b242 2794 ssh->crcda_ctx = crcda_make_context();
2795 logevent("Installing CRC compensation attack detector");
2796
679539d7 2797 if (servkey.modulus) {
2798 sfree(servkey.modulus);
2799 servkey.modulus = NULL;
2800 }
2801 if (servkey.exponent) {
2802 sfree(servkey.exponent);
2803 servkey.exponent = NULL;
2804 }
2805 if (hostkey.modulus) {
2806 sfree(hostkey.modulus);
2807 hostkey.modulus = NULL;
2808 }
2809 if (hostkey.exponent) {
2810 sfree(hostkey.exponent);
2811 hostkey.exponent = NULL;
2812 }
ff3187f6 2813 crWaitUntil(pktin);
374330e2 2814
ff3187f6 2815 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2816 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2817 crStop(0);
8d5de777 2818 }
374330e2 2819
c5e9c988 2820 logevent("Successfully started encryption");
2821
374330e2 2822 fflush(stdout);
2823 {
aa09f7d0 2824 if (!*ssh->cfg.username) {
c0a81592 2825 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2826 if (!ssh_get_line("login as: ",
51470298 2827 s->username, sizeof(s->username), FALSE)) {
32874aea 2828 /*
2829 * get_line failed to get a username.
2830 * Terminate.
2831 */
2832 logevent("No username provided. Abandoning session.");
3bb2f322 2833 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2834 crStop(1);
32874aea 2835 }
2836 } else {
51470298 2837 int ret; /* need not be kept over crReturn */
2838 c_write_str(ssh, "login as: ");
2839 ssh->send_ok = 1;
0405e71f 2840
51470298 2841 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2842 do {
ff3187f6 2843 crWaitUntil(!pktin);
51470298 2844 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2845 } while (ret == 0);
2846 if (ret < 0)
2847 cleanup_exit(0);
51470298 2848 c_write_str(ssh, "\r\n");
32874aea 2849 }
2850 } else {
86916870 2851 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2852 s->username[sizeof(s->username)-1] = '\0';
374330e2 2853 }
fb09bf1c 2854
51470298 2855 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2856 {
51470298 2857 char userlog[22 + sizeof(s->username)];
2858 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2859 logevent(userlog);
32874aea 2860 if (flags & FLAG_INTERACTIVE &&
2861 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2862 strcat(userlog, "\r\n");
51470298 2863 c_write_str(ssh, userlog);
3c8e959b 2864 }
c5e9c988 2865 }
374330e2 2866 }
2867
ff3187f6 2868 crWaitUntil(pktin);
374330e2 2869
51470298 2870 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2871 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2872 s->tried_publickey = s->tried_agent = 1;
0df73905 2873 } else {
51470298 2874 s->tried_publickey = s->tried_agent = 0;
0df73905 2875 }
51470298 2876 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2877 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2878 if (!filename_is_null(ssh->cfg.keyfile)) {
2879 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2880 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2881 s->publickey_blob = NULL;
396778f1 2882 } else
51470298 2883 s->publickey_blob = NULL;
7cca0d81 2884
ff3187f6 2885 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 2886 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2887
51470298 2888 if (agent_exists() && !s->tried_agent) {
32874aea 2889 /*
2890 * Attempt RSA authentication using Pageant.
2891 */
32874aea 2892 void *r;
2893
51470298 2894 s->authed = FALSE;
2895 s->tried_agent = 1;
32874aea 2896 logevent("Pageant is running. Requesting keys.");
2897
2898 /* Request the keys held by the agent. */
51470298 2899 PUT_32BIT(s->request, 1);
2900 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2901 if (!agent_query(s->request, 5, &r, &s->responselen,
2902 ssh_agent_callback, ssh)) {
2903 do {
2904 crReturn(0);
ff3187f6 2905 if (pktin) {
839f10db 2906 bombout(("Unexpected data from server while waiting"
2907 " for agent response"));
2908 crStop(0);
2909 }
ff3187f6 2910 } while (pktin || inlen > 0);
839f10db 2911 r = ssh->agent_response;
2912 s->responselen = ssh->agent_response_len;
2913 }
51470298 2914 s->response = (unsigned char *) r;
2915 if (s->response && s->responselen >= 5 &&
2916 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2917 s->p = s->response + 5;
2918 s->nkeys = GET_32BIT(s->p);
2919 s->p += 4;
32874aea 2920 {
2921 char buf[64];
51470298 2922 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2923 logevent(buf);
2924 }
51470298 2925 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2926 {
2927 char buf[64];
51470298 2928 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2929 logevent(buf);
2930 }
51470298 2931 if (s->publickey_blob &&
2932 !memcmp(s->p, s->publickey_blob,
2933 s->publickey_bloblen)) {
396778f1 2934 logevent("This key matches configured key file");
51470298 2935 s->tried_publickey = 1;
396778f1 2936 }
51470298 2937 s->p += 4;
0016d70b 2938 {
2939 int n, ok = FALSE;
2940 do { /* do while (0) to make breaking easy */
2941 n = ssh1_read_bignum
2942 (s->p, s->responselen-(s->p-s->response),
2943 &s->key.exponent);
2944 if (n < 0)
2945 break;
2946 s->p += n;
2947 n = ssh1_read_bignum
2948 (s->p, s->responselen-(s->p-s->response),
2949 &s->key.modulus);
2950 if (n < 0)
2951 break;
2952 s->p += n;
2953 if (s->responselen - (s->p-s->response) < 4)
2954 break;
2955 s->commentlen = GET_32BIT(s->p);
2956 s->p += 4;
2957 if (s->responselen - (s->p-s->response) <
2958 s->commentlen)
2959 break;
2960 s->commentp = (char *)s->p;
2961 s->p += s->commentlen;
2962 ok = TRUE;
2963 } while (0);
2964 if (!ok) {
2965 logevent("Pageant key list packet was truncated");
2966 break;
2967 }
2968 }
51470298 2969 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2970 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 2971 crWaitUntil(pktin);
2972 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2973 logevent("Key refused");
2974 continue;
2975 }
2976 logevent("Received RSA challenge");
ff3187f6 2977 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 2978 bombout(("Server's RSA challenge was badly formatted"));
2979 crStop(0);
2980 }
2981
32874aea 2982 {
2983 char *agentreq, *q, *ret;
2d466ffd 2984 void *vret;
32874aea 2985 int len, retlen;
2986 len = 1 + 4; /* message type, bit count */
51470298 2987 len += ssh1_bignum_length(s->key.exponent);
2988 len += ssh1_bignum_length(s->key.modulus);
2989 len += ssh1_bignum_length(s->challenge);
32874aea 2990 len += 16; /* session id */
2991 len += 4; /* response format */
3d88e64d 2992 agentreq = snewn(4 + len, char);
32874aea 2993 PUT_32BIT(agentreq, len);
2994 q = agentreq + 4;
2995 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2996 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2997 q += 4;
51470298 2998 q += ssh1_write_bignum(q, s->key.exponent);
2999 q += ssh1_write_bignum(q, s->key.modulus);
3000 q += ssh1_write_bignum(q, s->challenge);
3001 memcpy(q, s->session_id, 16);
32874aea 3002 q += 16;
3003 PUT_32BIT(q, 1); /* response format */
839f10db 3004 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3005 ssh_agent_callback, ssh)) {
3006 sfree(agentreq);
3007 do {
3008 crReturn(0);
ff3187f6 3009 if (pktin) {
839f10db 3010 bombout(("Unexpected data from server"
3011 " while waiting for agent"
3012 " response"));
3013 crStop(0);
3014 }
ff3187f6 3015 } while (pktin || inlen > 0);
839f10db 3016 vret = ssh->agent_response;
3017 retlen = ssh->agent_response_len;
3018 } else
3019 sfree(agentreq);
2d466ffd 3020 ret = vret;
32874aea 3021 if (ret) {
3022 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3023 logevent("Sending Pageant's response");
51470298 3024 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3025 PKT_DATA, ret + 5, 16,
3026 PKT_END);
3027 sfree(ret);
ff3187f6 3028 crWaitUntil(pktin);
3029 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3030 logevent
3031 ("Pageant's response accepted");
3032 if (flags & FLAG_VERBOSE) {
51470298 3033 c_write_str(ssh, "Authenticated using"
3034 " RSA key \"");
3035 c_write(ssh, s->commentp,
3036 s->commentlen);
3037 c_write_str(ssh, "\" from agent\r\n");
32874aea 3038 }
51470298 3039 s->authed = TRUE;
32874aea 3040 } else
3041 logevent
3042 ("Pageant's response not accepted");
3043 } else {
3044 logevent
3045 ("Pageant failed to answer challenge");
3046 sfree(ret);
3047 }
3048 } else {
3049 logevent("No reply received from Pageant");
3050 }
3051 }
51470298 3052 freebn(s->key.exponent);
3053 freebn(s->key.modulus);
3054 freebn(s->challenge);
3055 if (s->authed)
32874aea 3056 break;
3057 }
29b1d0b3 3058 sfree(s->response);
32874aea 3059 }
51470298 3060 if (s->authed)
32874aea 3061 break;
3062 }
9a30e26b 3063 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3064 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3065
86916870 3066 if (ssh->cfg.try_tis_auth &&
51470298 3067 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3068 !s->tis_auth_refused) {
3069 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3070 logevent("Requested TIS authentication");
51470298 3071 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3072 crWaitUntil(pktin);
3073 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3074 logevent("TIS authentication declined");
3075 if (flags & FLAG_INTERACTIVE)
51470298 3076 c_write_str(ssh, "TIS authentication refused.\r\n");
3077 s->tis_auth_refused = 1;
614a20a0 3078 continue;
32874aea 3079 } else {
0016d70b 3080 char *challenge;
3081 int challengelen;
3082
ff3187f6 3083 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3084 if (!challenge) {
3085 bombout(("TIS challenge packet was badly formed"));
3086 crStop(0);
3087 }
32874aea 3088 logevent("Received TIS challenge");
51470298 3089 if (challengelen > sizeof(s->prompt) - 1)
3090 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3091 memcpy(s->prompt, challenge, challengelen);
614a20a0 3092 /* Prompt heuristic comes from OpenSSH */
51470298 3093 strncpy(s->prompt + challengelen,
3094 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3095 "": "\r\nResponse: ",
51470298 3096 (sizeof s->prompt) - challengelen);
3097 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3098 }
3099 }
86916870 3100 if (ssh->cfg.try_tis_auth &&
51470298 3101 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3102 !s->ccard_auth_refused) {
3103 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3104 logevent("Requested CryptoCard authentication");
51470298 3105 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3106 crWaitUntil(pktin);
3107 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3108 logevent("CryptoCard authentication declined");
51470298 3109 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3110 s->ccard_auth_refused = 1;
614a20a0 3111 continue;
32874aea 3112 } else {
0016d70b 3113 char *challenge;
3114 int challengelen;
3115
ff3187f6 3116 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3117 if (!challenge) {
3118 bombout(("CryptoCard challenge packet was badly formed"));
3119 crStop(0);
3120 }
32874aea 3121 logevent("Received CryptoCard challenge");
51470298 3122 if (challengelen > sizeof(s->prompt) - 1)
3123 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3124 memcpy(s->prompt, challenge, challengelen);
51470298 3125 strncpy(s->prompt + challengelen,
3126 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3127 "" : "\r\nResponse: ",
51470298 3128 sizeof(s->prompt) - challengelen);
3129 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3130 }
3131 }
51470298 3132 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3133 sprintf(s->prompt, "%.90s@%.90s's password: ",
3134 s->username, ssh->savedhost);
32874aea 3135 }
51470298 3136 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3137 char *comment = NULL;
231ee168 3138 int type;
3139 char msgbuf[256];
32874aea 3140 if (flags & FLAG_VERBOSE)
51470298 3141 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3142 logeventf(ssh, "Trying public key \"%s\"",
3143 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3144 type = key_type(&ssh->cfg.keyfile);
231ee168 3145 if (type != SSH_KEYTYPE_SSH1) {
3146 sprintf(msgbuf, "Key is of wrong type (%s)",
3147 key_type_to_str(type));
3148 logevent(msgbuf);
51470298 3149 c_write_str(ssh, msgbuf);
3150 c_write_str(ssh, "\r\n");
3151 s->tried_publickey = 1;
231ee168 3152 continue;
3153 }
9a30e26b 3154 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3155 if (flags & FLAG_VERBOSE)
51470298 3156 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3157 goto tryauth;
3158 }
51470298 3159 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3160 sfree(comment);
3161 }
a52f067e 3162
614a20a0 3163 /*
3164 * Show password prompt, having first obtained it via a TIS
3165 * or CryptoCard exchange if we're doing TIS or CryptoCard
3166 * authentication.
3167 */
fa17a66e 3168 if (ssh_get_line) {
51470298 3169 if (!ssh_get_line(s->prompt, s->password,
3170 sizeof(s->password), TRUE)) {
32874aea 3171 /*
3172 * get_line failed to get a password (for example
3173 * because one was supplied on the command line
3174 * which has already failed to work). Terminate.
3175 */
51470298 3176 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3177 PKT_STR, "No more passwords available to try",
3178 PKT_END);
247308b5 3179 logevent("Unable to authenticate");
a8327734 3180 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3181 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3182 crStop(1);
32874aea 3183 }
fb09bf1c 3184 } else {
614a20a0 3185 /* Prompt may have come from server. We've munged it a bit, so
3186 * we know it to be zero-terminated at least once. */
51470298 3187 int ret; /* need not be saved over crReturn */
3188 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3189 s->pos = 0;
0405e71f 3190
51470298 3191 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3192 do {
ff3187f6 3193 crWaitUntil(!pktin);
51470298 3194 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3195 } while (ret == 0);
3196 if (ret < 0)
3197 cleanup_exit(0);
51470298 3198 c_write_str(ssh, "\r\n");
32874aea 3199 }
3200
3201 tryauth:
51470298 3202 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3203 /*
3204 * Try public key authentication with the specified
3205 * key file.
3206 */
51470298 3207 s->tried_publickey = 1;
3208
3209 {
222d54dc 3210 const char *error = NULL;
3211 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3212 &error);
51470298 3213 if (ret == 0) {
3214 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3215 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3216 c_write_str(ssh, " (");
3217 c_write_str(ssh, error);
3218 c_write_str(ssh, ").\r\n");
51470298 3219 continue; /* go and try password */
3220 }
3221 if (ret == -1) {
3222 c_write_str(ssh, "Wrong passphrase.\r\n");
3223 s->tried_publickey = 0;
3224 continue; /* try again */
3225 }
32874aea 3226 }
3227
3228 /*
3229 * Send a public key attempt.
3230 */
51470298 3231 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3232 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3233
ff3187f6 3234 crWaitUntil(pktin);
3235 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3236 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3237 continue; /* go and try password */
3238 }
ff3187f6 3239 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3240 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3241 crStop(0);
32874aea 3242 }
32874aea 3243
51470298 3244 {
3245 int i;
3246 unsigned char buffer[32];
3247 Bignum challenge, response;
3248
ff3187f6 3249 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3250 bombout(("Server's RSA challenge was badly formatted"));
3251 crStop(0);
3252 }
51470298 3253 response = rsadecrypt(challenge, &s->key);
3254 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3255
51470298 3256 for (i = 0; i < 32; i++) {
3257 buffer[i] = bignum_byte(response, 31 - i);
3258 }
3259
3260 MD5Init(&md5c);
3261 MD5Update(&md5c, buffer, 32);
3262 MD5Update(&md5c, s->session_id, 16);
3263 MD5Final(buffer, &md5c);
32874aea 3264
51470298 3265 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3266 PKT_DATA, buffer, 16, PKT_END);
3267
3268 freebn(challenge);
3269 freebn(response);
3270 }
32874aea 3271
ff3187f6 3272 crWaitUntil(pktin);
3273 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3274 if (flags & FLAG_VERBOSE)
51470298 3275 c_write_str(ssh, "Failed to authenticate with"
3276 " our public key.\r\n");
32874aea 3277 continue; /* go and try password */
ff3187f6 3278 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3279 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3280 crStop(0);
32874aea 3281 }
3282
3283 break; /* we're through! */
3284 } else {
51470298 3285 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3286 /*
3287 * Defence against traffic analysis: we send a
3288 * whole bunch of packets containing strings of
3289 * different lengths. One of these strings is the
3290 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3291 * The others are all random data in
3292 * SSH1_MSG_IGNORE packets. This way a passive
3293 * listener can't tell which is the password, and
3294 * hence can't deduce the password length.
3295 *
3296 * Anybody with a password length greater than 16
3297 * bytes is going to have enough entropy in their
3298 * password that a listener won't find it _that_
3299 * much help to know how long it is. So what we'll
3300 * do is:
3301 *
3302 * - if password length < 16, we send 15 packets
3303 * containing string lengths 1 through 15
3304 *
3305 * - otherwise, we let N be the nearest multiple
3306 * of 8 below the password length, and send 8
3307 * packets containing string lengths N through
3308 * N+7. This won't obscure the order of
3309 * magnitude of the password length, but it will
3310 * introduce a bit of extra uncertainty.
3311 *
3312 * A few servers (the old 1.2.18 through 1.2.22)
3313 * can't deal with SSH1_MSG_IGNORE. For these
3314 * servers, we need an alternative defence. We make
3315 * use of the fact that the password is interpreted
3316 * as a C string: so we can append a NUL, then some
3317 * random data.
bd358db1 3318 *
3319 * One server (a Cisco one) can deal with neither
3320 * SSH1_MSG_IGNORE _nor_ a padded password string.
3321 * For this server we are left with no defences
3322 * against password length sniffing.
32874aea 3323 */
51470298 3324 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3325 /*
3326 * The server can deal with SSH1_MSG_IGNORE, so
3327 * we can use the primary defence.
3328 */
32874aea 3329 int bottom, top, pwlen, i;
3330 char *randomstr;
3331
51470298 3332 pwlen = strlen(s->password);
32874aea 3333 if (pwlen < 16) {
3334 bottom = 0; /* zero length passwords are OK! :-) */
3335 top = 15;
3336 } else {
3337 bottom = pwlen & ~7;
3338 top = bottom + 7;
3339 }
3340
3341 assert(pwlen >= bottom && pwlen <= top);
3342
3d88e64d 3343 randomstr = snewn(top + 1, char);
32874aea 3344
3345 for (i = bottom; i <= top; i++) {
9a10ecf4 3346 if (i == pwlen) {
51470298 3347 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3348 PKTT_PASSWORD, PKT_STR, s->password,
3349 PKTT_OTHER, PKT_END);
3350 } else {
32874aea 3351 for (j = 0; j < i; j++) {
3352 do {
3353 randomstr[j] = random_byte();
3354 } while (randomstr[j] == '\0');
3355 }
3356 randomstr[i] = '\0';
51470298 3357 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3358 PKT_STR, randomstr, PKT_END);
3359 }
3360 }
bd358db1 3361 logevent("Sending password with camouflage packets");
51470298 3362 ssh_pkt_defersend(ssh);
679539d7 3363 sfree(randomstr);
bd358db1 3364 }
51470298 3365 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3366 /*
3367 * The server can't deal with SSH1_MSG_IGNORE
3368 * but can deal with padded passwords, so we
3369 * can use the secondary defence.
3370 */
bd358db1 3371 char string[64];
51470298 3372 char *ss;
bd358db1 3373 int len;
3374
51470298 3375 len = strlen(s->password);
bd358db1 3376 if (len < sizeof(string)) {
51470298 3377 ss = string;
3378 strcpy(string, s->password);
bd358db1 3379 len++; /* cover the zero byte */
3380 while (len < sizeof(string)) {
3381 string[len++] = (char) random_byte();
3382 }
3383 } else {
51470298 3384 ss = s->password;
bd358db1 3385 }
3386 logevent("Sending length-padded password");
9a10ecf4 3387 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3388 PKT_INT, len, PKT_DATA, ss, len,
3389 PKTT_OTHER, PKT_END);
bd358db1 3390 } else {
3391 /*
3392 * The server has _both_
3393 * BUG_CHOKES_ON_SSH1_IGNORE and
3394 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3395 * therefore nothing we can do.
3396 */
3397 int len;
51470298 3398 len = strlen(s->password);
bd358db1 3399 logevent("Sending unpadded password");
9a10ecf4 3400 send_packet(ssh, s->pwpkt_type,
3401 PKTT_PASSWORD, PKT_INT, len,
3402 PKT_DATA, s->password, len,
3403 PKTT_OTHER, PKT_END);
32874aea 3404 }
3405 } else {
9a10ecf4 3406 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3407 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3408 }
3409 }
c5e9c988 3410 logevent("Sent password");
51470298 3411 memset(s->password, 0, strlen(s->password));
ff3187f6 3412 crWaitUntil(pktin);
3413 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3414 if (flags & FLAG_VERBOSE)
51470298 3415 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3416 logevent("Authentication refused");
ff3187f6 3417 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3418 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3419 crStop(0);
374330e2 3420 }
3421 }
3422
c5e9c988 3423 logevent("Authentication successful");
3424
fb09bf1c 3425 crFinish(1);
3426}
3427
32874aea 3428void sshfwd_close(struct ssh_channel *c)
3429{
51470298 3430 Ssh ssh = c->ssh;
3431
36f94d1f 3432 if (ssh->state != SSH_STATE_SESSION) {
3433 assert(ssh->state == SSH_STATE_CLOSED);
3434 return;
3435 }
3436
80e48603 3437 if (c && !c->closes) {
4ed34d25 3438 /*
3439 * If the channel's remoteid is -1, we have sent
3440 * CHANNEL_OPEN for this channel, but it hasn't even been
3441 * acknowledged by the server. So we must set a close flag
3442 * on it now, and then when the server acks the channel
3443 * open, we can close it then.
3444 */
36cac739 3445 if (((int)c->remoteid) != -1) {
51470298 3446 if (ssh->version == 1) {
3447 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3448 PKT_END);
3449 } else {
ff3187f6 3450 struct Packet *pktout;
3451 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3452 ssh2_pkt_adduint32(pktout, c->remoteid);
3453 ssh2_pkt_send(ssh, pktout);
4ed34d25 3454 }
32874aea 3455 }
0357890f 3456 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3457 if (c->type == CHAN_X11) {
3458 c->u.x11.s = NULL;
d74d141c 3459 logevent("Forwarded X11 connection terminated");
4ed34d25 3460 } else if (c->type == CHAN_SOCKDATA ||
3461 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3462 c->u.pfd.s = NULL;
3463 logevent("Forwarded port closed");
32874aea 3464 }
3465 }
3466}
3467
5471d09a 3468int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3469{
51470298 3470 Ssh ssh = c->ssh;
3471
36f94d1f 3472 if (ssh->state != SSH_STATE_SESSION) {
3473 assert(ssh->state == SSH_STATE_CLOSED);
3474 return 0;
3475 }
3476
51470298 3477 if (ssh->version == 1) {
3478 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3479 PKT_INT, c->remoteid,
9a10ecf4 3480 PKTT_DATA,
3481 PKT_INT, len, PKT_DATA, buf, len,
3482 PKTT_OTHER, PKT_END);
5471d09a 3483 /*
3484 * In SSH1 we can return 0 here - implying that forwarded
3485 * connections are never individually throttled - because
3486 * the only circumstance that can cause throttling will be
3487 * the whole SSH connection backing up, in which case
3488 * _everything_ will be throttled as a whole.
3489 */
3490 return 0;
783415f8 3491 } else {
32874aea 3492 ssh2_add_channel_data(c, buf, len);
5471d09a 3493 return ssh2_try_send(c);
3494 }
3495}
3496
3497void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3498{
51470298 3499 Ssh ssh = c->ssh;
3500
36f94d1f 3501 if (ssh->state != SSH_STATE_SESSION) {
3502 assert(ssh->state == SSH_STATE_CLOSED);
3503 return;
3504 }
3505
51470298 3506 if (ssh->version == 1) {
5471d09a 3507 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3508 c->v.v1.throttling = 0;
51470298 3509 ssh1_throttle(ssh, -1);
5471d09a 3510 }
3511 } else {
3512 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3513 }
9c964e85 3514}
3515
51df0ab5 3516static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
3517{
3518 char *string;
3519 int stringlen, bufsize;
3520
3521 ssh_pkt_getstring(pktin, &string, &stringlen);
3522 if (string == NULL) {
3523 bombout(("Incoming terminal data packet was badly formed"));
3524 return;
3525 }
3526
3527 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
3528 string, stringlen);
3529 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3530 ssh->v1_stdout_throttling = 1;
3531 ssh1_throttle(ssh, +1);
3532 }
3533}
3534
3535static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
3536{
3537 /* Remote side is trying to open a channel to talk to our
3538 * X-Server. Give them back a local channel number. */
3539 struct ssh_channel *c;
3540 int remoteid = ssh_pkt_getuint32(pktin);
3541
3542 logevent("Received X11 connect request");
3543 /* Refuse if X11 forwarding is disabled. */
3544 if (!ssh->X11_fwd_enabled) {
3545 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3546 PKT_INT, remoteid, PKT_END);
3547 logevent("Rejected X11 connect request");
3548 } else {
3549 c = snew(struct ssh_channel);
3550 c->ssh = ssh;
3551
3552 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3553 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3554 logevent("Opening X11 forward connection failed");
3555 sfree(c);
3556 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3557 PKT_INT, remoteid, PKT_END);
3558 } else {
3559 logevent
3560 ("Opening X11 forward connection succeeded");
3561 c->remoteid = remoteid;
3562 c->localid = alloc_channel_id(ssh);
3563 c->closes = 0;
3564 c->v.v1.throttling = 0;
3565 c->type = CHAN_X11; /* identify channel type */
3566 add234(ssh->channels, c);
3567 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3568 PKT_INT, c->remoteid, PKT_INT,
3569 c->localid, PKT_END);
3570 logevent("Opened X11 forward channel");
3571 }
3572 }
3573}
3574
3575static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
3576{
3577 /* Remote side is trying to open a channel to talk to our
3578 * agent. Give them back a local channel number. */
3579 struct ssh_channel *c;
3580 int remoteid = ssh_pkt_getuint32(pktin);
3581
3582 /* Refuse if agent forwarding is disabled. */
3583 if (!ssh->agentfwd_enabled) {
3584 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3585 PKT_INT, remoteid, PKT_END);
3586 } else {
3587 c = snew(struct ssh_channel);
3588 c->ssh = ssh;
3589 c->remoteid = remoteid;
3590 c->localid = alloc_channel_id(ssh);
3591 c->closes = 0;
3592 c->v.v1.throttling = 0;
3593 c->type = CHAN_AGENT; /* identify channel type */
3594 c->u.a.lensofar = 0;
3595 add234(ssh->channels, c);
3596 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3597 PKT_INT, c->remoteid, PKT_INT, c->localid,
3598 PKT_END);
3599 }
3600}
3601
3602static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
3603{
3604 /* Remote side is trying to open a channel to talk to a
3605 * forwarded port. Give them back a local channel number. */
3606 struct ssh_channel *c;
3607 struct ssh_rportfwd pf;
3608 int remoteid;
3609 int hostsize, port;
3610 char *host, buf[1024];
3611 const char *e;
3612 c = snew(struct ssh_channel);
3613 c->ssh = ssh;
3614
3615 remoteid = ssh_pkt_getuint32(pktin);
3616 ssh_pkt_getstring(pktin, &host, &hostsize);
3617 port = ssh_pkt_getuint32(pktin);
3618
3619 if (hostsize >= lenof(pf.dhost))
3620 hostsize = lenof(pf.dhost)-1;
3621 memcpy(pf.dhost, host, hostsize);
3622 pf.dhost[hostsize] = '\0';
3623 pf.dport = port;
3624
3625 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3626 sprintf(buf, "Rejected remote port open request for %s:%d",
3627 pf.dhost, port);
3628 logevent(buf);
3629 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3630 PKT_INT, remoteid, PKT_END);
3631 } else {
3632 sprintf(buf, "Received remote port open request for %s:%d",
3633 pf.dhost, port);
3634 logevent(buf);
3635 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3636 c, &ssh->cfg);
3637 if (e != NULL) {
3638 char buf[256];
3639 sprintf(buf, "Port open failed: %s", e);
3640 logevent(buf);
3641 sfree(c);
3642 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3643 PKT_INT, remoteid, PKT_END);
3644 } else {
3645 c->remoteid = remoteid;
3646 c->localid = alloc_channel_id(ssh);
3647 c->closes = 0;
3648 c->v.v1.throttling = 0;
3649 c->type = CHAN_SOCKDATA; /* identify channel type */
3650 add234(ssh->channels, c);
3651 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3652 PKT_INT, c->remoteid, PKT_INT,
3653 c->localid, PKT_END);
3654 logevent("Forwarded port opened successfully");
3655 }
3656 }
3657}
3658
3659static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
3660{
3661 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3662 unsigned int localid = ssh_pkt_getuint32(pktin);
3663 struct ssh_channel *c;
3664
3665 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3666 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3667 c->remoteid = localid;
3668 c->type = CHAN_SOCKDATA;
3669 c->v.v1.throttling = 0;
3670 pfd_confirm(c->u.pfd.s);
3671 }
3672
3673 if (c && c->closes) {
3674 /*
3675 * We have a pending close on this channel,
3676 * which we decided on before the server acked
3677 * the channel open. So now we know the
3678 * remoteid, we can close it again.
3679 */
3680 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3681 PKT_INT, c->remoteid, PKT_END);
3682 }
3683}
3684
3685static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
3686{
3687 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3688 struct ssh_channel *c;
3689
3690 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3691 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3692 logevent("Forwarded connection refused by server");
3693 pfd_close(c->u.pfd.s);
3694 del234(ssh->channels, c);
3695 sfree(c);
3696 }
3697}
3698
3699static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
3700{
3701 /* Remote side closes a channel. */
3702 unsigned i = ssh_pkt_getuint32(pktin);
3703 struct ssh_channel *c;
3704 c = find234(ssh->channels, &i, ssh_channelfind);
3705 if (c && ((int)c->remoteid) != -1) {
3706 int closetype;
3707 closetype =
3708 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3709
3710 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3711 logevent("Forwarded X11 connection terminated");
3712 assert(c->u.x11.s != NULL);
3713 x11_close(c->u.x11.s);
3714 c->u.x11.s = NULL;
3715 }
3716 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3717 logevent("Forwarded port closed");
3718 assert(c->u.pfd.s != NULL);
3719 pfd_close(c->u.pfd.s);
3720 c->u.pfd.s = NULL;
3721 }
3722
3723 c->closes |= (closetype << 2); /* seen this message */
3724 if (!(c->closes & closetype)) {
3725 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
3726 PKT_END);
3727 c->closes |= closetype; /* sent it too */
3728 }
3729
3730 if (c->closes == 15) {
3731 del234(ssh->channels, c);
3732 sfree(c);
3733 }
3734 } else {
3735 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3736 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3737 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3738 i));
3739 }
3740}
3741
3742static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
3743{
3744 /* Data sent down one of our channels. */
3745 int i = ssh_pkt_getuint32(pktin);
3746 char *p;
3747 int len;
3748 struct ssh_channel *c;
3749
3750 ssh_pkt_getstring(pktin, &p, &len);
3751
3752 c = find234(ssh->channels, &i, ssh_channelfind);
3753 if (c) {
3754 int bufsize = 0;
3755 switch (c->type) {
3756 case CHAN_X11:
3757 bufsize = x11_send(c->u.x11.s, p, len);
3758 break;
3759 case CHAN_SOCKDATA:
3760 bufsize = pfd_send(c->u.pfd.s, p, len);
3761 break;
3762 case CHAN_AGENT:
3763 /* Data for an agent message. Buffer it. */
3764 while (len > 0) {
3765 if (c->u.a.lensofar < 4) {
3766 int l = min(4 - c->u.a.lensofar, len);
3767 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3768 l);
3769 p += l;
3770 len -= l;
3771 c->u.a.lensofar += l;
3772 }
3773 if (c->u.a.lensofar == 4) {
3774 c->u.a.totallen =
3775 4 + GET_32BIT(c->u.a.msglen);
3776 c->u.a.message = snewn(c->u.a.totallen,
3777 unsigned char);
3778 memcpy(c->u.a.message, c->u.a.msglen, 4);
3779 }
3780 if (c->u.a.lensofar >= 4 && len > 0) {
3781 int l =
3782 min(c->u.a.totallen - c->u.a.lensofar,
3783 len);
3784 memcpy(c->u.a.message + c->u.a.lensofar, p,
3785 l);
3786 p += l;
3787 len -= l;
3788 c->u.a.lensofar += l;
3789 }
3790 if (c->u.a.lensofar == c->u.a.totallen) {
3791 void *reply;
3792 int replylen;
3793 if (agent_query(c->u.a.message,
3794 c->u.a.totallen,
3795 &reply, &replylen,
3796 ssh_agentf_callback, c))
3797 ssh_agentf_callback(c, reply, replylen);
3798 sfree(c->u.a.message);
3799 c->u.a.lensofar = 0;
3800 }
3801 }
3802 bufsize = 0; /* agent channels never back up */
3803 break;
3804 }
3805 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3806 c->v.v1.throttling = 1;
3807 ssh1_throttle(ssh, +1);
3808 }
3809 }
3810}
3811
3812static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
3813{
3814 char buf[100];
3815 ssh->exitcode = ssh_pkt_getuint32(pktin);
3816 sprintf(buf, "Server sent command exit status %d",
3817 ssh->exitcode);
3818 logevent(buf);
3819 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3820 /*
3821 * In case `helpful' firewalls or proxies tack
3822 * extra human-readable text on the end of the
3823 * session which we might mistake for another
3824 * encrypted packet, we close the session once
3825 * we've sent EXIT_CONFIRMATION.
3826 */
3827 ssh_closing((Plug)ssh, NULL, 0, 0);
3828}
3829
b09eaa88 3830static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
3831 struct Packet *pktin)
32874aea 3832{
b09eaa88 3833 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 3834
51df0ab5 3835 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
3836 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
3837 ssh1_smsg_stdout_stderr_data;
3838
3839 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
3840 ssh1_msg_channel_open_confirmation;
3841 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
3842 ssh1_msg_channel_open_failure;
3843 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
3844 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
3845 ssh1_msg_channel_close;
3846 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
3847 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
3848
86916870 3849 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 3850 logevent("Requesting agent forwarding");
51470298 3851 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3852 do {
3853 crReturnV;
ff3187f6 3854 } while (!pktin);
3855 if (pktin->type != SSH1_SMSG_SUCCESS
3856 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3857 bombout(("Protocol confusion"));
7ffdbc1a 3858 crStopV;
ff3187f6 3859 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3860 logevent("Agent forwarding refused");
3861 } else {
3862 logevent("Agent forwarding enabled");
51470298 3863 ssh->agentfwd_enabled = TRUE;
51df0ab5 3864 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 3865 }
dacbd0e8 3866 }
3867
86916870 3868 if (ssh->cfg.x11_forward) {
32874aea 3869 char proto[20], data[64];
3870 logevent("Requesting X11 forwarding");
302121de 3871 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 3872 data, sizeof(data), ssh->cfg.x11_auth);
3873 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 3874 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3875 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3876 PKT_STR, proto, PKT_STR, data,
86916870 3877 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 3878 PKT_END);
32874aea 3879 } else {
51470298 3880 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3881 PKT_STR, proto, PKT_STR, data, PKT_END);
3882 }
3883 do {
3884 crReturnV;
ff3187f6 3885 } while (!pktin);
3886 if (pktin->type != SSH1_SMSG_SUCCESS
3887 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3888 bombout(("Protocol confusion"));
7ffdbc1a 3889 crStopV;
ff3187f6 3890 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3891 logevent("X11 forwarding refused");
3892 } else {
3893 logevent("X11 forwarding enabled");
51470298 3894 ssh->X11_fwd_enabled = TRUE;
51df0ab5 3895 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 3896 }
3897 }
3898
d74d141c 3899 {
9bf696b1 3900 char type;
d74d141c 3901 int n;
a4fc0d74 3902 int sport,dport,sserv,dserv;
6ee9b735 3903 char sports[256], dports[256], saddr[256], host[256];
d74d141c 3904
51470298 3905 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3906 /* Add port forwardings. */
86916870 3907 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 3908 while (*ssh->portfwd_strptr) {
3909 type = *ssh->portfwd_strptr++;
6ee9b735 3910 saddr[0] = '\0';
d74d141c 3911 n = 0;
6ee9b735 3912 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3913 if (*ssh->portfwd_strptr == ':') {
3914 /*
3915 * We've seen a colon in the middle of the
3916 * source port number. This means that
3917 * everything we've seen until now is the
3918 * source _address_, so we'll move it into
3919 * saddr and start sports from the beginning
3920 * again.
3921 */
3922 ssh->portfwd_strptr++;
3923 sports[n] = '\0';
3924 strcpy(saddr, sports);
3925 n = 0;
3926 }
3927 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3928 }
d74d141c 3929 sports[n] = 0;
820ebe3b 3930 if (type != 'D') {
3931 if (*ssh->portfwd_strptr == '\t')
3932 ssh->portfwd_strptr++;
3933 n = 0;
3934 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3935 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3936 }
3937 host[n] = 0;
3938 if (*ssh->portfwd_strptr == ':')
3939 ssh->portfwd_strptr++;
3940 n = 0;
3941 while (*ssh->portfwd_strptr) {
3942 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3943 }
3944 dports[n] = 0;
51470298 3945 ssh->portfwd_strptr++;
820ebe3b 3946 dport = atoi(dports);
3947 dserv = 0;
3948 if (dport == 0) {
3949 dserv = 1;
3950 dport = net_service_lookup(dports);
3951 if (!dport) {
3952 logeventf(ssh, "Service lookup failed for"
3953 " destination port \"%s\"", dports);
3954 }
a4fc0d74 3955 }
820ebe3b 3956 } else {
3957 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 3958 dport = dserv = -1;
7d5b0f4d 3959 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 3960 }
d74d141c 3961 sport = atoi(sports);
a4fc0d74 3962 sserv = 0;
3963 if (sport == 0) {
3964 sserv = 1;
68a49acb 3965 sport = net_service_lookup(sports);
3966 if (!sport) {
57356d63 3967 logeventf(ssh, "Service lookup failed for source"
3968 " port \"%s\"", sports);
a4fc0d74 3969 }
3970 }
d74d141c 3971 if (sport && dport) {
94ab1ddf 3972 /* Set up a description of the source port. */
c61c9cdf 3973 static char *sportdesc;
3974 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
94ab1ddf 3975 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3976 (int)(*saddr?1:0), ":",
3977 (int)(sserv ? strlen(sports) : 0), sports,
3978 sserv, "(", sport, sserv, ")");
d74d141c 3979 if (type == 'L') {
94ab1ddf 3980 /* Verbose description of the destination port */
3981 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3982 host,
3983 (int)(dserv ? strlen(dports) : 0), dports,
3984 dserv, "(", dport, dserv, ")");
3985 const char *err = pfd_addforward(host, dport,
3986 *saddr ? saddr : NULL,
3987 sport, ssh, &ssh->cfg);
3988 if (err) {
3989 logeventf(ssh, "Local port %s forward to %s"
3990 " failed: %s", sportdesc, dportdesc, err);
3991 } else {
3992 logeventf(ssh, "Local port %s forwarding to %s",
3993 sportdesc, dportdesc);
3994 }
3995 sfree(dportdesc);
820ebe3b 3996 } else if (type == 'D') {
94ab1ddf 3997 const char *err = pfd_addforward(NULL, -1,
3998 *saddr ? saddr : NULL,
3999 sport, ssh, &ssh->cfg);
4000 if (err) {
4001 logeventf(ssh, "Local port %s SOCKS dynamic forward"
4002 " setup failed: %s", sportdesc, err);
4003 } else {
4004 logeventf(ssh, "Local port %s doing SOCKS"
4005 " dynamic forwarding", sportdesc);
4006 }
d74d141c 4007 } else {
4008 struct ssh_rportfwd *pf;
3d88e64d 4009 pf = snew(struct ssh_rportfwd);
bc240b21 4010 strcpy(pf->dhost, host);
4011 pf->dport = dport;
0cd494d7 4012 if (*saddr) {
6ee9b735 4013 logeventf(ssh,
4014 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
4015 saddr, sport);
4016 }
51470298 4017 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 4018 logeventf(ssh,
4019 "Duplicate remote port forwarding to %s:%d",
4020 host, dport);
bc240b21 4021 sfree(pf);
d74d141c 4022 } else {
57356d63 4023 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
4024 " forward to %s:%.*s%.*s%d%.*s",
4025 (int)(sserv ? strlen(sports) : 0), sports,
4026 sserv, "(", sport, sserv, ")",
4027 host,
4028 (int)(dserv ? strlen(dports) : 0), dports,
4029 dserv, "(", dport, dserv, ")");
51470298 4030 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 4031 PKT_INT, sport,
4032 PKT_STR, host,
4033 PKT_INT, dport,
4034 PKT_END);
9bf696b1 4035 do {
4036 crReturnV;
ff3187f6 4037 } while (!pktin);
4038 if (pktin->type != SSH1_SMSG_SUCCESS
4039 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4040 bombout(("Protocol confusion"));
7ffdbc1a 4041 crStopV;
ff3187f6 4042 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4043 c_write_str(ssh, "Server refused port"
4044 " forwarding\r\n");
51df0ab5 4045 logevent("Server refused this port forwarding");
4046 } else {
4047 logevent("Remote port forwarding enabled");
4048 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] =
4049 ssh1_msg_port_open;
9bf696b1 4050 }
d74d141c 4051 }
4052 }
94ab1ddf 4053 sfree(sportdesc);
d74d141c 4054 }
4055 }
4056 }
4057
86916870 4058 if (!ssh->cfg.nopty) {
a5dd8467 4059 /* Unpick the terminal-speed string. */
4060 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4061 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4062 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4063 /* Send the pty request. */
51470298 4064 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4065 PKT_STR, ssh->cfg.termtype,
51470298 4066 PKT_INT, ssh->term_height,
4067 PKT_INT, ssh->term_width,
a5dd8467 4068 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4069 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4070 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4071 PKT_CHAR, 0, PKT_END);
51470298 4072 ssh->state = SSH_STATE_INTERMED;
32874aea 4073 do {
4074 crReturnV;
ff3187f6 4075 } while (!pktin);
4076 if (pktin->type != SSH1_SMSG_SUCCESS
4077 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4078 bombout(("Protocol confusion"));
7ffdbc1a 4079 crStopV;
ff3187f6 4080 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4081 c_write_str(ssh, "Server refused to allocate pty\r\n");
4082 ssh->editing = ssh->echoing = 1;
32874aea 4083 }
a5dd8467 4084 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4085 ssh->ospeed, ssh->ispeed);
0965bee0 4086 } else {
51470298 4087 ssh->editing = ssh->echoing = 1;
374330e2 4088 }
4089
86916870 4090 if (ssh->cfg.compression) {
51470298 4091 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4092 do {
4093 crReturnV;
ff3187f6 4094 } while (!pktin);
4095 if (pktin->type != SSH1_SMSG_SUCCESS
4096 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4097 bombout(("Protocol confusion"));
7ffdbc1a 4098 crStopV;
ff3187f6 4099 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4100 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4101 }
4ba9b64b 4102 logevent("Started compression");
51470298 4103 ssh->v1_compressing = TRUE;
5366aed8 4104 ssh->cs_comp_ctx = zlib_compress_init();
4105 logevent("Initialised zlib (RFC1950) compression");
4106 ssh->sc_comp_ctx = zlib_decompress_init();
4107 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4108 }
4109
fd5e5847 4110 /*
4111 * Start the shell or command.
4112 *
4113 * Special case: if the first-choice command is an SSH2
4114 * subsystem (hence not usable here) and the second choice
4115 * exists, we fall straight back to that.
4116 */
4117 {
86916870 4118 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 4119
86916870 4120 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4121 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4122 ssh->fallback_cmd = TRUE;
fd5e5847 4123 }
4124 if (*cmd)
51470298 4125 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4126 else
51470298 4127 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4128 logevent("Started session");
4129 }
374330e2 4130
51470298 4131 ssh->state = SSH_STATE_SESSION;
4132 if (ssh->size_needed)
4133 ssh_size(ssh, ssh->term_width, ssh->term_height);
4134 if (ssh->eof_needed)
4135 ssh_special(ssh, TS_EOF);
374330e2 4136
b9d7bcad 4137 if (ssh->ldisc)
4138 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4139 ssh->send_ok = 1;
4140 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4141 while (1) {
d74d141c 4142
51df0ab5 4143 /*
4144 * By this point, most incoming packets are already being
4145 * handled by the dispatch table, and we need only pay
4146 * attention to the unusual ones.
4147 */
0357890f 4148
51df0ab5 4149 crReturnV;
4150 if (pktin) {
4151 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4152 /* may be from EXEC_SHELL on some servers */
ff3187f6 4153 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4154 /* may be from EXEC_SHELL on some servers
374330e2 4155 * if no pty is available or in other odd cases. Ignore */
374330e2 4156 } else {
ff3187f6 4157 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4158 crStopV;
374330e2 4159 }
4160 } else {
8df7a775 4161 while (inlen > 0) {
4162 int len = min(inlen, 512);
9a10ecf4 4163 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4164 PKT_INT, len, PKT_DATA, in, len,
4165 PKTT_OTHER, PKT_END);
8df7a775 4166 in += len;
4167 inlen -= len;
4168 }
374330e2 4169 }
4170 }
4171
4172 crFinishV;
4173}
4174
4175/*
b09eaa88 4176 * Handle the top-level SSH2 protocol.
4177 */
4178static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4179{
4180 char *buf, *msg;
4181 int msglen;
4182
4183 ssh_pkt_getstring(pktin, &msg, &msglen);
4184 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4185 logevent(buf);
4186 sfree(buf);
4187}
4188
4189static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4190{
4191 /* log reason code in disconnect message */
4192 char *msg;
4193 int msglen;
4194
4195 ssh_pkt_getstring(pktin, &msg, &msglen);
4196 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4197}
4198
4199void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4200{
4201 /* Do nothing, because we're ignoring it! Duhh. */
4202}
4203
4204static void ssh1_protocol_setup(Ssh ssh)
4205{
4206 int i;
4207
4208 /*
4209 * Most messages are handled by the coroutines.
4210 */
4211 for (i = 0; i < 256; i++)
4212 ssh->packet_dispatch[i] = NULL;
4213
4214 /*
4215 * These special message types we install handlers for.
4216 */
4217 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4218 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4219 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4220}
4221
4222static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4223 struct Packet *pktin)
4224{
4225 if (ssh->state == SSH_STATE_CLOSED)
4226 return;
4227
4228 if (pktin && ssh->packet_dispatch[pktin->type]) {
4229 ssh->packet_dispatch[pktin->type](ssh, pktin);
4230 return;
4231 }
4232
4233 if (!ssh->protocol_initial_phase_done) {
4234 if (do_ssh1_login(ssh, in, inlen, pktin))
4235 ssh->protocol_initial_phase_done = TRUE;
4236 else
4237 return;
4238 }
4239
4240 do_ssh1_connection(ssh, in, inlen, pktin);
4241}
4242
4243/*
e5574168 4244 * Utility routine for decoding comma-separated strings in KEXINIT.
4245 */
32874aea 4246static int in_commasep_string(char *needle, char *haystack, int haylen)
4247{
57356d63 4248 int needlen;
4249 if (!needle || !haystack) /* protect against null pointers */
4250 return 0;
4251 needlen = strlen(needle);
e5574168 4252 while (1) {
32874aea 4253 /*
4254 * Is it at the start of the string?
4255 */
4256 if (haylen >= needlen && /* haystack is long enough */
4257 !memcmp(needle, haystack, needlen) && /* initial match */
4258 (haylen == needlen || haystack[needlen] == ',')
4259 /* either , or EOS follows */
4260 )
4261 return 1;
4262 /*
4263 * If not, search for the next comma and resume after that.
4264 * If no comma found, terminate.
4265 */
4266 while (haylen > 0 && *haystack != ',')
4267 haylen--, haystack++;
4268 if (haylen == 0)
4269 return 0;
4270 haylen--, haystack++; /* skip over comma itself */
e5574168 4271 }
4272}
4273
4274/*
d39f364a 4275 * SSH2 key creation method.
4276 */
d8baa528 4277static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4278 unsigned char *sessid, char chr,
4279 unsigned char *keyspace)
32874aea 4280{
d39f364a 4281 SHA_State s;
4282 /* First 20 bytes. */
4283 SHA_Init(&s);
51470298 4284 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4285 sha_mpint(&s, K);
d39f364a 4286 SHA_Bytes(&s, H, 20);
4287 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4288 SHA_Bytes(&s, sessid, 20);
d39f364a 4289 SHA_Final(&s, keyspace);
4290 /* Next 20 bytes. */
4291 SHA_Init(&s);
51470298 4292 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4293 sha_mpint(&s, K);
d39f364a 4294 SHA_Bytes(&s, H, 20);
4295 SHA_Bytes(&s, keyspace, 20);
32874aea 4296 SHA_Final(&s, keyspace + 20);
d39f364a 4297}
4298
4299/*
7cca0d81 4300 * Handle the SSH2 transport layer.
e5574168 4301 */
ff3187f6 4302static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4303 struct Packet *pktin)
e5574168 4304{
51470298 4305 struct do_ssh2_transport_state {
4306 int nbits, pbits, warn;
4307 Bignum p, g, e, f, K;
4308 int kex_init_value, kex_reply_value;
4309 const struct ssh_mac **maclist;
4310 int nmacs;
4311 const struct ssh2_cipher *cscipher_tobe;
4312 const struct ssh2_cipher *sccipher_tobe;
4313 const struct ssh_mac *csmac_tobe;
4314 const struct ssh_mac *scmac_tobe;
4315 const struct ssh_compress *cscomp_tobe;
4316 const struct ssh_compress *sccomp_tobe;
4317 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4318 int hostkeylen, siglen;
4319 void *hkey; /* actual host key */
4320 unsigned char exchange_hash[20];
4321 int n_preferred_ciphers;
4322 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4323 const struct ssh_compress *preferred_comp;
4324 int first_kex;
ff3187f6 4325 struct Packet *pktout;
51470298 4326 };
4327 crState(do_ssh2_transport_state);
4328
4329 crBegin(ssh->do_ssh2_transport_crstate);
4330
4331 s->cscipher_tobe = s->sccipher_tobe = NULL;
4332 s->csmac_tobe = s->scmac_tobe = NULL;
4333 s->cscomp_tobe = s->sccomp_tobe = NULL;
4334
51470298 4335 s->first_kex = 1;
e5574168 4336
51470298 4337 {
4338 int i;
4339 /*
4340 * Set up the preferred ciphers. (NULL => warn below here)
4341 */
4342 s->n_preferred_ciphers = 0;
4343 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4344 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4345 case CIPHER_BLOWFISH:
4346 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4347 break;
4348 case CIPHER_DES:
86916870 4349 if (ssh->cfg.ssh2_des_cbc) {
51470298 4350 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4351 }
4352 break;
4353 case CIPHER_3DES:
4354 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4355 break;
4356 case CIPHER_AES:
4357 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4358 break;
4359 case CIPHER_WARN:
4360 /* Flag for later. Don't bother if it's the last in
4361 * the list. */
4362 if (i < CIPHER_MAX - 1) {
4363 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4364 }
4365 break;
ca20bfcf 4366 }
ca20bfcf 4367 }
5e8358ad 4368 }
ca20bfcf 4369
4370 /*
4371 * Set up preferred compression.
4372 */
86916870 4373 if (ssh->cfg.compression)
51470298 4374 s->preferred_comp = &ssh_zlib;
4ba9b64b 4375 else
51470298 4376 s->preferred_comp = &ssh_comp_none;
5e8358ad 4377
7591b9ff 4378 /*
4379 * Be prepared to work around the buggy MAC problem.
4380 */
51470298 4381 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4382 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 4383 else
51470298 4384 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 4385
32874aea 4386 begin_key_exchange:
51470298 4387 {
4388 int i, j, cipherstr_started;
4389
4390 /*
590f6a5f 4391 * Enable queueing of outgoing auth- or connection-layer
4392 * packets while we are in the middle of a key exchange.
4393 */
4394 ssh->queueing = TRUE;
4395
4396 /*
9442dd57 4397 * Flag that KEX is in progress.
4398 */
4399 ssh->kex_in_progress = TRUE;
4400
4401 /*
51470298 4402 * Construct and send our key exchange packet.
4403 */
ff3187f6 4404 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4405 for (i = 0; i < 16; i++)
ff3187f6 4406 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4407 /* List key exchange algorithms. */
ff3187f6 4408 ssh2_pkt_addstring_start(s->pktout);
51470298 4409 for (i = 0; i < lenof(kex_algs); i++) {
4410 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4411 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4412 continue;
ff3187f6 4413 ssh2_pkt_addstring_str(s->pktout, kex_algs[i]->name);
51470298 4414 if (i < lenof(kex_algs) - 1)
ff3187f6 4415 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4416 }
51470298 4417 /* List server host key algorithms. */
ff3187f6 4418 ssh2_pkt_addstring_start(s->pktout);
51470298 4419 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4420 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4421 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4422 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4423 }
51470298 4424 /* List client->server encryption algorithms. */
ff3187f6 4425 ssh2_pkt_addstring_start(s->pktout);
51470298 4426 cipherstr_started = 0;
4427 for (i = 0; i < s->n_preferred_ciphers; i++) {
4428 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4429 if (!c) continue; /* warning flag */
4430 for (j = 0; j < c->nciphers; j++) {
4431 if (cipherstr_started)
ff3187f6 4432 ssh2_pkt_addstring_str(s->pktout, ",");
4433 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
51470298 4434 cipherstr_started = 1;
4435 }
4436 }
4437 /* List server->client encryption algorithms. */
ff3187f6 4438 ssh2_pkt_addstring_start(s->pktout);
51470298 4439 cipherstr_started = 0;
4440 for (i = 0; i < s->n_preferred_ciphers; i++) {
4441 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4442 if (!c) continue; /* warning flag */
4443 for (j = 0; j < c->nciphers; j++) {
4444 if (cipherstr_started)
ff3187f6 4445 ssh2_pkt_addstring_str(s->pktout, ",");
4446 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
51470298 4447 cipherstr_started = 1;
4448 }
4449 }
4450 /* List client->server MAC algorithms. */
ff3187f6 4451 ssh2_pkt_addstring_start(s->pktout);
51470298 4452 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4453 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4454 if (i < s->nmacs - 1)
ff3187f6 4455 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4456 }
4457 /* List server->client MAC algorithms. */
ff3187f6 4458 ssh2_pkt_addstring_start(s->pktout);
51470298 4459 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4460 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4461 if (i < s->nmacs - 1)
ff3187f6 4462 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4463 }
4464 /* List client->server compression algorithms. */
ff3187f6 4465 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4466 assert(lenof(compressions) > 1);
ff3187f6 4467 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4468 for (i = 0; i < lenof(compressions); i++) {
4469 const struct ssh_compress *c = compressions[i];
4470 if (c != s->preferred_comp) {
ff3187f6 4471 ssh2_pkt_addstring_str(s->pktout, ",");
4472 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4473 }
51470298 4474 }
4475 /* List server->client compression algorithms. */
ff3187f6 4476 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4477 assert(lenof(compressions) > 1);
ff3187f6 4478 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4479 for (i = 0; i < lenof(compressions); i++) {
4480 const struct ssh_compress *c = compressions[i];
4481 if (c != s->preferred_comp) {
ff3187f6 4482 ssh2_pkt_addstring_str(s->pktout, ",");
4483 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4484 }
51470298 4485 }
4486 /* List client->server languages. Empty list. */
ff3187f6 4487 ssh2_pkt_addstring_start(s->pktout);
51470298 4488 /* List server->client languages. Empty list. */
ff3187f6 4489 ssh2_pkt_addstring_start(s->pktout);
51470298 4490 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4491 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4492 /* Reserved. */
ff3187f6 4493 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4494 }
0db56f73 4495
51470298 4496 ssh->exhash = ssh->exhashbase;
ff3187f6 4497 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4498
590f6a5f 4499 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4500
ff3187f6 4501 if (!pktin)
4502 crWaitUntil(pktin);
4503 if (pktin->length > 5)
4504 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4505
4506 /*
4507 * Now examine the other side's KEXINIT to see what we're up
4508 * to.
4509 */
51470298 4510 {
4511 char *str;
4512 int i, j, len;
4513
ff3187f6 4514 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4515 bombout(("expected key exchange packet from server"));
7ffdbc1a 4516 crStop(0);
32874aea 4517 }
51470298 4518 ssh->kex = NULL;
4519 ssh->hostkey = NULL;
4520 s->cscipher_tobe = NULL;
4521 s->sccipher_tobe = NULL;
4522 s->csmac_tobe = NULL;
4523 s->scmac_tobe = NULL;
4524 s->cscomp_tobe = NULL;
4525 s->sccomp_tobe = NULL;
ff3187f6 4526 pktin->savedpos += 16; /* skip garbage cookie */
4527 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
51470298 4528 for (i = 0; i < lenof(kex_algs); i++) {
4529 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4530 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4531 continue;
4532 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4533 ssh->kex = kex_algs[i];
4534 break;
4535 }
32874aea 4536 }
ff3187f6 4537 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4538 for (i = 0; i < lenof(hostkey_algs); i++) {
4539 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4540 ssh->hostkey = hostkey_algs[i];
4541 break;
4542 }
4543 }
ff3187f6 4544 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4545 s->warn = 0;
4546 for (i = 0; i < s->n_preferred_ciphers; i++) {
4547 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4548 if (!c) {
4549 s->warn = 1;
4550 } else {
4551 for (j = 0; j < c->nciphers; j++) {
4552 if (in_commasep_string(c->list[j]->name, str, len)) {
4553 s->cscipher_tobe = c->list[j];
4554 break;
4555 }
ca20bfcf 4556 }
32874aea 4557 }
51470298 4558 if (s->cscipher_tobe) {
4559 if (s->warn)
a8327734 4560 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 4561 break;
4562 }
32874aea 4563 }
51470298 4564 if (!s->cscipher_tobe) {
6b5cf8b4 4565 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4566 str ? str : "(null)"));
7ffdbc1a 4567 crStop(0);
ca20bfcf 4568 }
0ef8f407 4569
ff3187f6 4570 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4571 s->warn = 0;
4572 for (i = 0; i < s->n_preferred_ciphers; i++) {
4573 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4574 if (!c) {
4575 s->warn = 1;
4576 } else {
4577 for (j = 0; j < c->nciphers; j++) {
4578 if (in_commasep_string(c->list[j]->name, str, len)) {
4579 s->sccipher_tobe = c->list[j];
4580 break;
4581 }
ca20bfcf 4582 }
32874aea 4583 }
51470298 4584 if (s->sccipher_tobe) {
4585 if (s->warn)
a8327734 4586 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 4587 break;
4588 }
32874aea 4589 }
51470298 4590 if (!s->sccipher_tobe) {
6b5cf8b4 4591 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4592 str ? str : "(null)"));
7ffdbc1a 4593 crStop(0);
ca20bfcf 4594 }
0ef8f407 4595
ff3187f6 4596 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 4597 for (i = 0; i < s->nmacs; i++) {
4598 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4599 s->csmac_tobe = s->maclist[i];
4600 break;
4601 }
32874aea 4602 }
ff3187f6 4603 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 4604 for (i = 0; i < s->nmacs; i++) {
4605 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4606 s->scmac_tobe = s->maclist[i];
4607 break;
4608 }
32874aea 4609 }
ff3187f6 4610 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 4611 for (i = 0; i < lenof(compressions) + 1; i++) {
4612 const struct ssh_compress *c =
4613 i == 0 ? s->preferred_comp : compressions[i - 1];
4614 if (in_commasep_string(c->name, str, len)) {
4615 s->cscomp_tobe = c;
4616 break;
4617 }
32874aea 4618 }
ff3187f6 4619 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 4620 for (i = 0; i < lenof(compressions) + 1; i++) {
4621 const struct ssh_compress *c =
4622 i == 0 ? s->preferred_comp : compressions[i - 1];
4623 if (in_commasep_string(c->name, str, len)) {
4624 s->sccomp_tobe = c;
4625 break;
4626 }
32874aea 4627 }
e5574168 4628 }
e5574168 4629
4630 /*
7bd5a860 4631 * Work out the number of bits of key we will need from the key
4632 * exchange. We start with the maximum key length of either
4633 * cipher...
4634 */
4635 {
32874aea 4636 int csbits, scbits;
7bd5a860 4637
51470298 4638 csbits = s->cscipher_tobe->keylen;
4639 scbits = s->sccipher_tobe->keylen;
4640 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 4641 }
4642 /* The keys only have 160-bit entropy, since they're based on
4643 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 4644 if (s->nbits > 160)
4645 s->nbits = 160;
7bd5a860 4646
4647 /*
a92dd380 4648 * If we're doing Diffie-Hellman group exchange, start by
4649 * requesting a group.
e5574168 4650 */
51470298 4651 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 4652 logevent("Doing Diffie-Hellman group exchange");
51470298 4653 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 4654 /*
4655 * Work out how big a DH group we will need to allow that
4656 * much data.
7bd5a860 4657 */
51470298 4658 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 4659 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
4660 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 4661 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 4662
ff3187f6 4663 crWaitUntil(pktin);
4664 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 4665 bombout(("expected key exchange group packet from server"));
7ffdbc1a 4666 crStop(0);
32874aea 4667 }
ff3187f6 4668 s->p = ssh2_pkt_getmp(pktin);
4669 s->g = ssh2_pkt_getmp(pktin);
4670 if (!s->p || !s->g) {
4671 bombout(("unable to read mp-ints from incoming group packet"));
4672 crStop(0);
4673 }
27cd7fc2 4674 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 4675 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4676 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 4677 } else {
51470298 4678 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 4679 ssh->kex_ctx = dh_setup_group1();
51470298 4680 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4681 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 4682 }
e5574168 4683
a92dd380 4684 logevent("Doing Diffie-Hellman key exchange");
e5574168 4685 /*
a92dd380 4686 * Now generate and send e for Diffie-Hellman.
e5574168 4687 */
27cd7fc2 4688 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 4689 s->pktout = ssh2_pkt_init(s->kex_init_value);
4690 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 4691 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4692
ff3187f6 4693 crWaitUntil(pktin);
4694 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 4695 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 4696 crStop(0);
7cca0d81 4697 }
ff3187f6 4698 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
4699 s->f = ssh2_pkt_getmp(pktin);
4700 if (!s->f) {
4701 bombout(("unable to parse key exchange reply packet"));
4702 crStop(0);
4703 }
4704 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 4705
27cd7fc2 4706 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4707
51470298 4708 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4709 if (ssh->kex == &ssh_diffiehellman_gex) {
4710 sha_uint32(&ssh->exhash, s->pbits);
4711 sha_mpint(&ssh->exhash, s->p);
4712 sha_mpint(&ssh->exhash, s->g);
a92dd380 4713 }
51470298 4714 sha_mpint(&ssh->exhash, s->e);
4715 sha_mpint(&ssh->exhash, s->f);
4716 sha_mpint(&ssh->exhash, s->K);
4717 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4718
27cd7fc2 4719 dh_cleanup(ssh->kex_ctx);
fabd1805 4720 ssh->kex_ctx = NULL;
3709bfe9 4721
7cca0d81 4722#if 0
765c4200 4723 debug(("Exchange hash is:\n"));
51470298 4724 dmemdump(s->exchange_hash, 20);
7cca0d81 4725#endif
4726
51470298 4727 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4728 if (!s->hkey ||
4729 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 4730 (char *)s->exchange_hash, 20)) {
6b5cf8b4 4731 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 4732 crStop(0);
8d5de777 4733 }
e5574168 4734
4735 /*
7cca0d81 4736 * Authenticate remote host: verify host key. (We've already
4737 * checked the signature of the exchange hash.)
e5574168 4738 */
51470298 4739 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4740 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4741 verify_ssh_host_key(ssh->frontend,
4742 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4743 s->keystr, s->fingerprint);
4744 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4745 logevent("Host key fingerprint is:");
51470298 4746 logevent(s->fingerprint);
5e0d7cb8 4747 }
51470298 4748 sfree(s->fingerprint);
4749 sfree(s->keystr);
4750 ssh->hostkey->freekey(s->hkey);
d39f364a 4751
4752 /*
9442dd57 4753 * The exchange hash from the very first key exchange is also
4754 * the session id, used in session key construction and
4755 * authentication.
4756 */
4757 if (s->first_kex)
4758 memcpy(ssh->v2_session_id, s->exchange_hash,
4759 sizeof(s->exchange_hash));
4760
4761 /*
7cca0d81 4762 * Send SSH2_MSG_NEWKEYS.
d39f364a 4763 */
ff3187f6 4764 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 4765 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 4766 ssh->outgoing_data_size = 0; /* start counting from here */
4767
4768 /*
4769 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 4770 * client-to-server session keys.
9442dd57 4771 */
4772 if (ssh->cs_cipher_ctx)
4773 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4774 ssh->cscipher = s->cscipher_tobe;
4775 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4776
4777 if (ssh->cs_mac_ctx)
4778 ssh->csmac->free_context(ssh->cs_mac_ctx);
4779 ssh->csmac = s->csmac_tobe;
4780 ssh->cs_mac_ctx = ssh->csmac->make_context();
4781
4782 if (ssh->cs_comp_ctx)
4783 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4784 ssh->cscomp = s->cscomp_tobe;
4785 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4786
4787 /*
4788 * Set IVs on client-to-server keys. Here we use the exchange
4789 * hash from the _first_ key exchange.
4790 */
4791 {
4792 unsigned char keyspace[40];
4793 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4794 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4795 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4796 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4797 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4798 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4799 }
4800
4801 logeventf(ssh, "Initialised %.200s client->server encryption",
4802 ssh->cscipher->text_name);
4803 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4804 ssh->csmac->text_name);
4805 if (ssh->cscomp->text_name)
4806 logeventf(ssh, "Initialised %s compression",
4807 ssh->cscomp->text_name);
590f6a5f 4808
4809 /*
4810 * Now our end of the key exchange is complete, we can send all
4811 * our queued higher-layer packets.
4812 */
4813 ssh->queueing = FALSE;
4814 ssh2_pkt_queuesend(ssh);
d39f364a 4815
4816 /*
8406eaf9 4817 * Expect SSH2_MSG_NEWKEYS from server.
4818 */
ff3187f6 4819 crWaitUntil(pktin);
4820 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 4821 bombout(("expected new-keys packet from server"));
7ffdbc1a 4822 crStop(0);
8406eaf9 4823 }
9442dd57 4824 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 4825
4826 /*
9442dd57 4827 * We've seen server NEWKEYS, so create and initialise
4828 * server-to-client session keys.
d39f364a 4829 */
371e569c 4830 if (ssh->sc_cipher_ctx)
4831 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4832 ssh->sccipher = s->sccipher_tobe;
371e569c 4833 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4834
e0e1a00d 4835 if (ssh->sc_mac_ctx)
4836 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4837 ssh->scmac = s->scmac_tobe;
e0e1a00d 4838 ssh->sc_mac_ctx = ssh->scmac->make_context();
4839
5366aed8 4840 if (ssh->sc_comp_ctx)
4841 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4842 ssh->sccomp = s->sccomp_tobe;
5366aed8 4843 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4844
d39f364a 4845 /*
9442dd57 4846 * Set IVs on server-to-client keys. Here we use the exchange
4847 * hash from the _first_ key exchange.
d39f364a 4848 */
51470298 4849 {
4850 unsigned char keyspace[40];
51470298 4851 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4852 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4853 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4854 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4855 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4856 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4857 }
57356d63 4858 logeventf(ssh, "Initialised %.200s server->client encryption",
4859 ssh->sccipher->text_name);
6c135243 4860 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4861 ssh->scmac->text_name);
57356d63 4862 if (ssh->sccomp->text_name)
4863 logeventf(ssh, "Initialised %s decompression",
4864 ssh->sccomp->text_name);
9442dd57 4865
4866 /*
4867 * Free key exchange data.
4868 */
679539d7 4869 freebn(s->f);
679539d7 4870 freebn(s->K);
b3949e7e 4871 if (ssh->kex == &ssh_diffiehellman_gex) {
4872 freebn(s->g);
4873 freebn(s->p);
4874 }
d39f364a 4875
033b4cef 4876 /*
9442dd57 4877 * Key exchange is over. Schedule a timer for our next rekey.
4878 */
4879 ssh->kex_in_progress = FALSE;
4880 ssh->next_rekey = schedule_timer(REKEY_TIMEOUT, ssh2_timer, ssh);
4881
4882 /*
0db56f73 4883 * If this is the first key exchange phase, we must pass the
4884 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4885 * wants to see it but because it will need time to initialise
4886 * itself before it sees an actual packet. In subsequent key
4887 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4888 * it would only confuse the layer above.
4889 */
51470298 4890 if (!s->first_kex) {
b09eaa88 4891 crReturn(1);
0db56f73 4892 }
51470298 4893 s->first_kex = 0;
0db56f73 4894
4895 /*
7cca0d81 4896 * Now we're encrypting. Begin returning 1 to the protocol main
4897 * function so that other things can run on top of the
4898 * transport. If we ever see a KEXINIT, we must go back to the
4899 * start.
9442dd57 4900 *
4901 * We _also_ go back to the start if we see pktin==NULL and
4902 * inlen==-1, because this is a special signal meaning
4903 * `initiate client-driven rekey', and `in' contains a message
4904 * giving the reason for the rekey.
033b4cef 4905 */
9442dd57 4906 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
4907 (!pktin && inlen == -1))) {
32874aea 4908 crReturn(1);
e96adf72 4909 }
9442dd57 4910 if (pktin) {
4911 logevent("Server initiated key re-exchange");
4912 } else {
4913 logevent((char *)in);
4914 }
7cca0d81 4915 goto begin_key_exchange;
e5574168 4916
4917 crFinish(1);
4918}
4919
7cca0d81 4920/*
783415f8 4921 * Add data to an SSH2 channel output buffer.
4922 */
32874aea 4923static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4924 int len)
4925{
5471d09a 4926 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4927}
4928
4929/*
4930 * Attempt to send data on an SSH2 channel.
4931 */
5471d09a 4932static int ssh2_try_send(struct ssh_channel *c)
32874aea 4933{
51470298 4934 Ssh ssh = c->ssh;
ff3187f6 4935 struct Packet *pktout;
51470298 4936
5471d09a 4937 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4938 int len;
4939 void *data;
4940 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4941 if ((unsigned)len > c->v.v2.remwindow)
4942 len = c->v.v2.remwindow;
4943 if ((unsigned)len > c->v.v2.remmaxpkt)
4944 len = c->v.v2.remmaxpkt;
ff3187f6 4945 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4946 ssh2_pkt_adduint32(pktout, c->remoteid);
4947 dont_log_data(ssh, pktout, PKTLOG_OMIT);
4948 ssh2_pkt_addstring_start(pktout);
4949 ssh2_pkt_addstring_data(pktout, data, len);
4950 end_log_omission(ssh, pktout);
4951 ssh2_pkt_send(ssh, pktout);
5471d09a 4952 bufchain_consume(&c->v.v2.outbuffer, len);
4953 c->v.v2.remwindow -= len;
4954 }
4955
4956 /*
4957 * After having sent as much data as we can, return the amount
4958 * still buffered.
4959 */
4960 return bufchain_size(&c->v.v2.outbuffer);
4961}
4962
4963/*
4964 * Potentially enlarge the window on an SSH2 channel.
4965 */
4966static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4967{
51470298 4968 Ssh ssh = c->ssh;
4969
6b69f42e 4970 /*
4971 * Never send WINDOW_ADJUST for a channel that the remote side
4972 * already thinks it's closed; there's no point, since it won't
4973 * be sending any more data anyway.
4974 */
4975 if (c->closes != 0)
4976 return;
4977
5471d09a 4978 if (newwin > c->v.v2.locwindow) {
ff3187f6 4979 struct Packet *pktout;
4980
4981 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4982 ssh2_pkt_adduint32(pktout, c->remoteid);
4983 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
4984 ssh2_pkt_send(ssh, pktout);
5471d09a 4985 c->v.v2.locwindow = newwin;
783415f8 4986 }
4987}
4988
51df0ab5 4989static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 4990{
4991 unsigned i = ssh_pkt_getuint32(pktin);
4992 struct ssh_channel *c;
4993 c = find234(ssh->channels, &i, ssh_channelfind);
4994 if (c && !c->closes)
4995 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
4996}
4997
51df0ab5 4998static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
4999{
5000 char *data;
5001 int length;
5002 unsigned i = ssh_pkt_getuint32(pktin);
5003 struct ssh_channel *c;
5004 c = find234(ssh->channels, &i, ssh_channelfind);
5005 if (!c)
5006 return; /* nonexistent channel */
5007 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5008 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5009 return; /* extended but not stderr */
5010 ssh_pkt_getstring(pktin, &data, &length);
5011 if (data) {
5012 int bufsize = 0;
5013 c->v.v2.locwindow -= length;
5014 switch (c->type) {
5015 case CHAN_MAINSESSION:
5016 bufsize =
5017 from_backend(ssh->frontend, pktin->type ==
5018 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5019 data, length);
5020 break;
5021 case CHAN_X11:
5022 bufsize = x11_send(c->u.x11.s, data, length);
5023 break;
5024 case CHAN_SOCKDATA:
5025 bufsize = pfd_send(c->u.pfd.s, data, length);
5026 break;
5027 case CHAN_AGENT:
5028 while (length > 0) {
5029 if (c->u.a.lensofar < 4) {
5030 int l = min(4 - c->u.a.lensofar, length);
5031 memcpy(c->u.a.msglen + c->u.a.lensofar,
5032 data, l);
5033 data += l;
5034 length -= l;
5035 c->u.a.lensofar += l;
5036 }
5037 if (c->u.a.lensofar == 4) {
5038 c->u.a.totallen =
5039 4 + GET_32BIT(c->u.a.msglen);
5040 c->u.a.message = snewn(c->u.a.totallen,
5041 unsigned char);
5042 memcpy(c->u.a.message, c->u.a.msglen, 4);
5043 }
5044 if (c->u.a.lensofar >= 4 && length > 0) {
5045 int l =
5046 min(c->u.a.totallen - c->u.a.lensofar,
5047 length);
5048 memcpy(c->u.a.message + c->u.a.lensofar,
5049 data, l);
5050 data += l;
5051 length -= l;
5052 c->u.a.lensofar += l;
5053 }
5054 if (c->u.a.lensofar == c->u.a.totallen) {
5055 void *reply;
5056 int replylen;
5057 if (agent_query(c->u.a.message,
5058 c->u.a.totallen,
5059 &reply, &replylen,
5060 ssh_agentf_callback, c))
5061 ssh_agentf_callback(c, reply, replylen);
5062 sfree(c->u.a.message);
5063 c->u.a.lensofar = 0;
5064 }
5065 }
5066 bufsize = 0;
5067 break;
5068 }
5069 /*
5070 * If we are not buffering too much data,
5071 * enlarge the window again at the remote side.
5072 */
5073 if (bufsize < OUR_V2_WINSIZE)
5074 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5075 }
5076}
5077
5078static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5079{
5080 unsigned i = ssh_pkt_getuint32(pktin);
5081 struct ssh_channel *c;
5082
5083 c = find234(ssh->channels, &i, ssh_channelfind);
5084 if (!c)
5085 return; /* nonexistent channel */
5086
5087 if (c->type == CHAN_X11) {
5088 /*
5089 * Remote EOF on an X11 channel means we should
5090 * wrap up and close the channel ourselves.
5091 */
5092 x11_close(c->u.x11.s);
5093 sshfwd_close(c);
5094 } else if (c->type == CHAN_AGENT) {
5095 sshfwd_close(c);
5096 } else if (c->type == CHAN_SOCKDATA) {
5097 pfd_close(c->u.pfd.s);
5098 sshfwd_close(c);
5099 }
5100}
5101
5102static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5103{
5104 unsigned i = ssh_pkt_getuint32(pktin);
5105 struct ssh_channel *c;
5106 struct Packet *pktout;
5107
5108 c = find234(ssh->channels, &i, ssh_channelfind);
5109 if (!c || ((int)c->remoteid) == -1) {
5110 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5111 c ? "half-open" : "nonexistent", i));
5112 return;
5113 }
5114 /* Do pre-close processing on the channel. */
5115 switch (c->type) {
5116 case CHAN_MAINSESSION:
5117 ssh->mainchan = NULL;
5118 update_specials_menu(ssh->frontend);
5119 break;
5120 case CHAN_X11:
5121 if (c->u.x11.s != NULL)
5122 x11_close(c->u.x11.s);
5123 sshfwd_close(c);
5124 break;
5125 case CHAN_AGENT:
5126 sshfwd_close(c);
5127 break;
5128 case CHAN_SOCKDATA:
5129 if (c->u.pfd.s != NULL)
5130 pfd_close(c->u.pfd.s);
5131 sshfwd_close(c);
5132 break;
5133 }
5134 if (c->closes == 0) {
5135 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5136 ssh2_pkt_adduint32(pktout, c->remoteid);
5137 ssh2_pkt_send(ssh, pktout);
5138 }
5139 del234(ssh->channels, c);
5140 bufchain_clear(&c->v.v2.outbuffer);
5141 sfree(c);
5142
5143 /*
5144 * See if that was the last channel left open.
5145 * (This is only our termination condition if we're
5146 * not running in -N mode.)
5147 */
5148 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5149 logevent("All channels closed. Disconnecting");
5150#if 0
5151 /*
5152 * We used to send SSH_MSG_DISCONNECT here,
5153 * because I'd believed that _every_ conforming
5154 * SSH2 connection had to end with a disconnect
5155 * being sent by at least one side; apparently
5156 * I was wrong and it's perfectly OK to
5157 * unceremoniously slam the connection shut
5158 * when you're done, and indeed OpenSSH feels
5159 * this is more polite than sending a
5160 * DISCONNECT. So now we don't.
5161 */
5162 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5163 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5164 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5165 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5166 ssh2_pkt_send_noqueue(ssh, s->pktout);
5167#endif
5168 ssh_closing((Plug)ssh, NULL, 0, 0);
5169 }
5170}
5171
5172static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5173{
5174 unsigned i = ssh_pkt_getuint32(pktin);
5175 struct ssh_channel *c;
5176 struct Packet *pktout;
5177
5178 c = find234(ssh->channels, &i, ssh_channelfind);
5179 if (!c)
5180 return; /* nonexistent channel */
5181 if (c->type != CHAN_SOCKDATA_DORMANT)
5182 return; /* dunno why they're confirming this */
5183 c->remoteid = ssh_pkt_getuint32(pktin);
5184 c->type = CHAN_SOCKDATA;
5185 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5186 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5187 if (c->u.pfd.s)
5188 pfd_confirm(c->u.pfd.s);
5189 if (c->closes) {
5190 /*
5191 * We have a pending close on this channel,
5192 * which we decided on before the server acked
5193 * the channel open. So now we know the
5194 * remoteid, we can close it again.
5195 */
5196 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5197 ssh2_pkt_adduint32(pktout, c->remoteid);
5198 ssh2_pkt_send(ssh, pktout);
5199 }
5200}
5201
5202static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5203{
5204 static const char *const reasons[] = {
5205 "<unknown reason code>",
5206 "Administratively prohibited",
5207 "Connect failed",
5208 "Unknown channel type",
5209 "Resource shortage",
5210 };
5211 unsigned i = ssh_pkt_getuint32(pktin);
5212 unsigned reason_code;
5213 char *reason_string;
5214 int reason_length;
5215 char *message;
5216 struct ssh_channel *c;
5217 c = find234(ssh->channels, &i, ssh_channelfind);
5218 if (!c)
5219 return; /* nonexistent channel */
5220 if (c->type != CHAN_SOCKDATA_DORMANT)
5221 return; /* dunno why they're failing this */
5222
5223 reason_code = ssh_pkt_getuint32(pktin);
5224 if (reason_code >= lenof(reasons))
5225 reason_code = 0; /* ensure reasons[reason_code] in range */
5226 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5227 message = dupprintf("Forwarded connection refused by"
5228 " server: %s [%.*s]", reasons[reason_code],
5229 reason_length, reason_string);
5230 logevent(message);
5231 sfree(message);
5232
5233 pfd_close(c->u.pfd.s);
5234
5235 del234(ssh->channels, c);
5236 sfree(c);
5237}
5238
5239static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5240{
5241 unsigned localid;
5242 char *type;
5243 int typelen, want_reply;
5244 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5245 struct ssh_channel *c;
5246 struct Packet *pktout;
5247
5248 localid = ssh_pkt_getuint32(pktin);
5249 ssh_pkt_getstring(pktin, &type, &typelen);
5250 want_reply = ssh2_pkt_getbool(pktin);
5251
5252 /*
5253 * First, check that the channel exists. Otherwise,
5254 * we can instantly disconnect with a rude message.
5255 */
5256 c = find234(ssh->channels, &localid, ssh_channelfind);
5257 if (!c) {
5258 char buf[80];
5259 sprintf(buf, "Received channel request for nonexistent"
5260 " channel %d", localid);
5261 logevent(buf);
5262 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5263 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5264 ssh2_pkt_addstring(pktout, buf);
5265 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5266 ssh2_pkt_send_noqueue(ssh, pktout);
5267 connection_fatal(ssh->frontend, "%s", buf);
5268 ssh_closing((Plug)ssh, NULL, 0, 0);
5269 return;
5270 }
5271
5272 /*
5273 * Having got the channel number, we now look at
5274 * the request type string to see if it's something
5275 * we recognise.
5276 */
5277 if (c == ssh->mainchan) {
5278 /*
5279 * We recognise "exit-status" and "exit-signal" on
5280 * the primary channel.
5281 */
5282 if (typelen == 11 &&
5283 !memcmp(type, "exit-status", 11)) {
5284
5285 ssh->exitcode = ssh_pkt_getuint32(pktin);
5286 logeventf(ssh, "Server sent command exit status %d",
5287 ssh->exitcode);
5288 reply = SSH2_MSG_CHANNEL_SUCCESS;
5289
5290 } else if (typelen == 11 &&
5291 !memcmp(type, "exit-signal", 11)) {
5292
5293 int is_plausible = TRUE, is_int = FALSE;
5294 char *fmt_sig = "", *fmt_msg = "";
5295 char *msg;
5296 int msglen = 0, core = FALSE;
5297 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5298 * provide an `int' for the signal, despite its
5299 * having been a `string' in the drafts since at
5300 * least 2001. (Fixed in session.c 1.147.) Try to
5301 * infer which we can safely parse it as. */
5302 {
5303 unsigned char *p = pktin->body +
5304 pktin->savedpos;
5305 long len = pktin->length - pktin->savedpos;
5306 unsigned long num = GET_32BIT(p); /* what is it? */
5307 /* If it's 0, it hardly matters; assume string */
5308 if (num == 0) {
5309 is_int = FALSE;
5310 } else {
5311 int maybe_int = FALSE, maybe_str = FALSE;
5312#define CHECK_HYPOTHESIS(offset, result) \
5313 do { \
5314 long q = offset; \
5315 if (q >= 0 && q+4 <= len) { \
5316 q = q + 4 + GET_32BIT(p+q); \
5317 if (q >= 0 && q+4 <= len && \
5318 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5319 result = TRUE; \
5320 } \
5321 } while(0)
5322 CHECK_HYPOTHESIS(4+1, maybe_int);
5323 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5324#undef CHECK_HYPOTHESIS
5325 if (maybe_int && !maybe_str)
5326 is_int = TRUE;
5327 else if (!maybe_int && maybe_str)
5328 is_int = FALSE;
5329 else
5330 /* Crikey. Either or neither. Panic. */
5331 is_plausible = FALSE;
5332 }
5333 }
5334 if (is_plausible) {
5335 if (is_int) {
5336 /* Old non-standard OpenSSH. */
5337 int signum = ssh_pkt_getuint32(pktin);
5338 fmt_sig = dupprintf(" %d", signum);
5339 } else {
5340 /* As per the drafts. */
5341 char *sig;
5342 int siglen;
5343 ssh_pkt_getstring(pktin, &sig, &siglen);
5344 /* Signal name isn't supposed to be blank, but
5345 * let's cope gracefully if it is. */
5346 if (siglen) {
5347 fmt_sig = dupprintf(" \"%.*s\"",
5348 siglen, sig);
5349 }
5350 }
5351 core = ssh2_pkt_getbool(pktin);
5352 ssh_pkt_getstring(pktin, &msg, &msglen);
5353 if (msglen) {
5354 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5355 }
5356 /* ignore lang tag */
5357 } /* else don't attempt to parse */
5358 logeventf(ssh, "Server exited on signal%s%s%s",
5359 fmt_sig, core ? " (core dumped)" : "",
5360 fmt_msg);
5361 if (*fmt_sig) sfree(fmt_sig);
5362 if (*fmt_msg) sfree(fmt_msg);
5363 reply = SSH2_MSG_CHANNEL_SUCCESS;
5364
5365 }
5366 } else {
5367 /*
5368 * This is a channel request we don't know
5369 * about, so we now either ignore the request
5370 * or respond with CHANNEL_FAILURE, depending
5371 * on want_reply.
5372 */
5373 reply = SSH2_MSG_CHANNEL_FAILURE;
5374 }
5375 if (want_reply) {
5376 pktout = ssh2_pkt_init(reply);
5377 ssh2_pkt_adduint32(pktout, c->remoteid);
5378 ssh2_pkt_send(ssh, pktout);
5379 }
5380}
5381
5382static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5383{
5384 char *type;
5385 int typelen, want_reply;
5386 struct Packet *pktout;
5387
5388 ssh_pkt_getstring(pktin, &type, &typelen);
5389 want_reply = ssh2_pkt_getbool(pktin);
5390
5391 /*
5392 * We currently don't support any global requests
5393 * at all, so we either ignore the request or
5394 * respond with REQUEST_FAILURE, depending on
5395 * want_reply.
5396 */
5397 if (want_reply) {
5398 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5399 ssh2_pkt_send(ssh, pktout);
5400 }
5401}
5402
5403static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5404{
5405 char *type;
5406 int typelen;
5407 char *peeraddr;
5408 int peeraddrlen;
5409 int peerport;
5410 char *error = NULL;
5411 struct ssh_channel *c;
5412 unsigned remid, winsize, pktsize;
5413 struct Packet *pktout;
5414
5415 ssh_pkt_getstring(pktin, &type, &typelen);
5416 c = snew(struct ssh_channel);
5417 c->ssh = ssh;
5418
5419 remid = ssh_pkt_getuint32(pktin);
5420 winsize = ssh_pkt_getuint32(pktin);
5421 pktsize = ssh_pkt_getuint32(pktin);
5422
5423 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5424 char *addrstr;
5425
5426 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5427 addrstr = snewn(peeraddrlen+1, char);
5428 memcpy(addrstr, peeraddr, peeraddrlen);
5429 addrstr[peeraddrlen] = '\0';
5430 peerport = ssh_pkt_getuint32(pktin);
5431
5432 logeventf(ssh, "Received X11 connect request from %s:%d",
5433 addrstr, peerport);
5434
5435 if (!ssh->X11_fwd_enabled)
5436 error = "X11 forwarding is not enabled";
5437 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5438 ssh->x11auth, addrstr, peerport,
5439 &ssh->cfg) != NULL) {
5440 error = "Unable to open an X11 connection";
5441 } else {
5442 logevent("Opening X11 forward connection succeeded");
5443 c->type = CHAN_X11;
5444 }
5445
5446 sfree(addrstr);
5447 } else if (typelen == 15 &&
5448 !memcmp(type, "forwarded-tcpip", 15)) {
5449 struct ssh_rportfwd pf, *realpf;
5450 char *dummy;
5451 int dummylen;
5452 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5453 pf.sport = ssh_pkt_getuint32(pktin);
5454 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5455 peerport = ssh_pkt_getuint32(pktin);
5456 realpf = find234(ssh->rportfwds, &pf, NULL);
5457 logeventf(ssh, "Received remote port %d open request "
5458 "from %s:%d", pf.sport, peeraddr, peerport);
5459 if (realpf == NULL) {
5460 error = "Remote port is not recognised";
5461 } else {
5462 const char *e = pfd_newconnect(&c->u.pfd.s,
5463 realpf->dhost,
5464 realpf->dport, c,
5465 &ssh->cfg);
5466 logeventf(ssh, "Attempting to forward remote port to "
5467 "%s:%d", realpf->dhost, realpf->dport);
5468 if (e != NULL) {
5469 logeventf(ssh, "Port open failed: %s", e);
5470 error = "Port open failed";
5471 } else {
5472 logevent("Forwarded port opened successfully");
5473 c->type = CHAN_SOCKDATA;
5474 }
5475 }
5476 } else if (typelen == 22 &&
5477 !memcmp(type, "auth-agent@openssh.com", 3)) {
5478 if (!ssh->agentfwd_enabled)
5479 error = "Agent forwarding is not enabled";
5480 else {
5481 c->type = CHAN_AGENT; /* identify channel type */
5482 c->u.a.lensofar = 0;
5483 }
5484 } else {
5485 error = "Unsupported channel type requested";
5486 }
5487
5488 c->remoteid = remid;
5489 if (error) {
5490 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5491 ssh2_pkt_adduint32(pktout, c->remoteid);
5492 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5493 ssh2_pkt_addstring(pktout, error);
5494 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5495 ssh2_pkt_send(ssh, pktout);
5496 logeventf(ssh, "Rejected channel open: %s", error);
5497 sfree(c);
5498 } else {
5499 c->localid = alloc_channel_id(ssh);
5500 c->closes = 0;
5501 c->v.v2.locwindow = OUR_V2_WINSIZE;
5502 c->v.v2.remwindow = winsize;
5503 c->v.v2.remmaxpkt = pktsize;
5504 bufchain_init(&c->v.v2.outbuffer);
5505 add234(ssh->channels, c);
5506 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5507 ssh2_pkt_adduint32(pktout, c->remoteid);
5508 ssh2_pkt_adduint32(pktout, c->localid);
5509 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5510 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5511 ssh2_pkt_send(ssh, pktout);
5512 }
5513}
5514
783415f8 5515/*
7cca0d81 5516 * Handle the SSH2 userauth and connection layers.
5517 */
ff3187f6 5518static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5519 struct Packet *pktin)
7cca0d81 5520{
51470298 5521 struct do_ssh2_authconn_state {
5522 enum {
5523 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5524 AUTH_PASSWORD,
5525 AUTH_KEYBOARD_INTERACTIVE
5526 } method;
5527 enum {
5528 AUTH_TYPE_NONE,
5529 AUTH_TYPE_PUBLICKEY,
5530 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5531 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5532 AUTH_TYPE_PASSWORD,
5533 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5534 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5535 } type;
5536 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5537 int tried_pubkey_config, tried_agent, tried_keyb_inter;
5538 int kbd_inter_running;
5539 int we_are_in;
5540 int num_prompts, curr_prompt, echo;
5541 char username[100];
5542 int got_username;
85fdbe25 5543 char pwprompt[512];
51470298 5544 char password[100];
5545 void *publickey_blob;
5546 int publickey_bloblen;
5547 unsigned char request[5], *response, *p;
5548 int responselen;
5549 int keyi, nkeys;
5550 int authed;
5551 char *pkblob, *alg, *commentp;
5552 int pklen, alglen, commentlen;
5553 int siglen, retlen, len;
5554 char *q, *agentreq, *ret;
5555 int try_send;
73feed4f 5556 int num_env, env_left, env_ok;
ff3187f6 5557 struct Packet *pktout;
51470298 5558 };
5559 crState(do_ssh2_authconn_state);
5560
5561 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 5562
7cca0d81 5563 /*
5564 * Request userauth protocol, and await a response to it.
5565 */
ff3187f6 5566 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5567 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5568 ssh2_pkt_send(ssh, s->pktout);
5569 crWaitUntilV(pktin);
5570 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 5571 bombout(("Server refused user authentication protocol"));
7ffdbc1a 5572 crStopV;
8d5de777 5573 }
7cca0d81 5574
5575 /*
1408a877 5576 * We repeat this whole loop, including the username prompt,
5577 * until we manage a successful authentication. If the user
51470298 5578 * types the wrong _password_, they can be sent back to the
5579 * beginning to try another username, if this is configured on.
5580 * (If they specify a username in the config, they are never
5581 * asked, even if they do give a wrong password.)
1408a877 5582 *
5583 * I think this best serves the needs of
5584 *
5585 * - the people who have no configuration, no keys, and just
5586 * want to try repeated (username,password) pairs until they
5587 * type both correctly
5588 *
5589 * - people who have keys and configuration but occasionally
5590 * need to fall back to passwords
5591 *
5592 * - people with a key held in Pageant, who might not have
5593 * logged in to a particular machine before; so they want to
5594 * type a username, and then _either_ their key will be
5595 * accepted, _or_ they will type a password. If they mistype
5596 * the username they will want to be able to get back and
5597 * retype it!
7cca0d81 5598 */
51470298 5599 s->username[0] = '\0';
5600 s->got_username = FALSE;
1408a877 5601 do {
1408a877 5602 /*
5603 * Get a username.
5604 */
86916870 5605 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 5606 /*
5607 * We got a username last time round this loop, and
5608 * with change_username turned off we don't try to get
5609 * it again.
5610 */
aa09f7d0 5611 } else if (!*ssh->cfg.username) {
c0a81592 5612 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 5613 if (!ssh_get_line("login as: ",
51470298 5614 s->username, sizeof(s->username), FALSE)) {
32874aea 5615 /*
5616 * get_line failed to get a username.
5617 * Terminate.
5618 */
5619 logevent("No username provided. Abandoning session.");
3bb2f322 5620 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5621 crStopV;
32874aea 5622 }
5623 } else {
51470298 5624 int ret; /* need not be saved across crReturn */
5625 c_write_str(ssh, "login as: ");
5626 ssh->send_ok = 1;
5627 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 5628 do {
ff3187f6 5629 crWaitUntilV(!pktin);
51470298 5630 ret = process_userpass_input(ssh, in, inlen);
0405e71f 5631 } while (ret == 0);
5632 if (ret < 0)
5633 cleanup_exit(0);
4ca0c9d1 5634 c_write_str(ssh, "\r\n");
32874aea 5635 }
51470298 5636 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 5637 } else {
57356d63 5638 char *stuff;
86916870 5639 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 5640 s->username[sizeof(s->username)-1] = '\0';
65a22376 5641 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 5642 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 5643 c_write_str(ssh, stuff);
57356d63 5644 sfree(stuff);
7cca0d81 5645 }
5646 }
51470298 5647 s->got_username = TRUE;
7cca0d81 5648
65a22376 5649 /*
1408a877 5650 * Send an authentication request using method "none": (a)
5651 * just in case it succeeds, and (b) so that we know what
5652 * authentication methods we can usefully try next.
65a22376 5653 */
51470298 5654 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5655
ff3187f6 5656 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5657 ssh2_pkt_addstring(s->pktout, s->username);
5658 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
5659 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5660 ssh2_pkt_send(ssh, s->pktout);
51470298 5661 s->type = AUTH_TYPE_NONE;
5662 s->gotit = FALSE;
5663 s->we_are_in = FALSE;
5664
5665 s->tried_pubkey_config = FALSE;
5666 s->tried_agent = FALSE;
5667 s->tried_keyb_inter = FALSE;
5668 s->kbd_inter_running = FALSE;
86916870 5669 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 5670 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 5671 int keytype;
6c6d9ed9 5672 logeventf(ssh, "Reading private key file \"%.150s\"",
5673 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 5674 keytype = key_type(&ssh->cfg.keyfile);
51470298 5675 if (keytype == SSH_KEYTYPE_SSH2) {
5676 s->publickey_blob =
9a30e26b 5677 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 5678 &s->publickey_bloblen, NULL);
51470298 5679 } else {
57356d63 5680 char *msgbuf;
c2ad7d0d 5681 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 5682 key_type_to_str(keytype));
57356d63 5683 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 5684 " (%s)\r\n",
5685 filename_to_str(&ssh->cfg.keyfile),
57356d63 5686 key_type_to_str(keytype));
51470298 5687 c_write_str(ssh, msgbuf);
57356d63 5688 sfree(msgbuf);
51470298 5689 s->publickey_blob = NULL;
231ee168 5690 }
396778f1 5691 } else
51470298 5692 s->publickey_blob = NULL;
65a22376 5693
1408a877 5694 while (1) {
5695 /*
5696 * Wait for the result of the last authentication request.
5697 */
51470298 5698 if (!s->gotit)
ff3187f6 5699 crWaitUntilV(pktin);
5700 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 5701 char *banner;
5702 int size;
5703 /*
5704 * Don't show the banner if we're operating in
5705 * non-verbose non-interactive mode. (It's probably
5706 * a script, which means nobody will read the
5707 * banner _anyway_, and moreover the printing of
5708 * the banner will screw up processing on the
5709 * output of (say) plink.)
5710 */
5711 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 5712 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 5713 if (banner)
51470298 5714 c_write_untrusted(ssh, banner, size);
32874aea 5715 }
ff3187f6 5716 crWaitUntilV(pktin);
1408a877 5717 }
ff3187f6 5718 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 5719 logevent("Access granted");
51470298 5720 s->we_are_in = TRUE;
1408a877 5721 break;
5722 }
65a22376 5723
51470298 5724 if (s->kbd_inter_running &&
ff3187f6 5725 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 5726 /*
45068b27 5727 * This is either a further set-of-prompts packet
5728 * in keyboard-interactive authentication, or it's
5729 * the same one and we came back here with `gotit'
5730 * set. In the former case, we must reset the
5731 * curr_prompt variable.
b3186d64 5732 */
51470298 5733 if (!s->gotit)
5734 s->curr_prompt = 0;
ff3187f6 5735 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 5736 bombout(("Strange packet received during authentication: type %d",
ff3187f6 5737 pktin->type));
7ffdbc1a 5738 crStopV;
65a22376 5739 }
5740
51470298 5741 s->gotit = FALSE;
65a22376 5742
1408a877 5743 /*
5744 * OK, we're now sitting on a USERAUTH_FAILURE message, so
5745 * we can look at the string in it and know what we can
5746 * helpfully try next.
5747 */
ff3187f6 5748 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 5749 char *methods;
5750 int methlen;
ff3187f6 5751 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 5752 s->kbd_inter_running = FALSE;
ff3187f6 5753 if (!ssh2_pkt_getbool(pktin)) {
1408a877 5754 /*
5755 * We have received an unequivocal Access
5756 * Denied. This can translate to a variety of
5757 * messages:
5758 *
5759 * - if we'd just tried "none" authentication,
5760 * it's not worth printing anything at all
5761 *
5762 * - if we'd just tried a public key _offer_,
5763 * the message should be "Server refused our
5764 * key" (or no message at all if the key
5765 * came from Pageant)
5766 *
5767 * - if we'd just tried anything else, the
5768 * message really should be "Access denied".
5769 *
5770 * Additionally, if we'd just tried password
5771 * authentication, we should break out of this
5772 * whole loop so as to go back to the username
91f57d1f 5773 * prompt (iff we're configured to allow
5774 * username change attempts).
1408a877 5775 */
51470298 5776 if (s->type == AUTH_TYPE_NONE) {
1408a877 5777 /* do nothing */
51470298 5778 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5779 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5780 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5781 c_write_str(ssh, "Server refused our key\r\n");
1408a877 5782 logevent("Server refused public key");
51470298 5783 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 5784 /* server declined keyboard-interactive; ignore */
1408a877 5785 } else {
51470298 5786 c_write_str(ssh, "Access denied\r\n");
1408a877 5787 logevent("Access denied");
91f57d1f 5788 if (s->type == AUTH_TYPE_PASSWORD &&
5789 ssh->cfg.change_username) {
6c9dce7c 5790 /* XXX perhaps we should allow
5791 * keyboard-interactive to do this too? */
51470298 5792 s->we_are_in = FALSE;
1408a877 5793 break;
5794 }
5795 }
5796 } else {
51470298 5797 c_write_str(ssh, "Further authentication required\r\n");
1408a877 5798 logevent("Further authentication required");
5799 }
65a22376 5800
51470298 5801 s->can_pubkey =
32874aea 5802 in_commasep_string("publickey", methods, methlen);
51470298 5803 s->can_passwd =
32874aea 5804 in_commasep_string("password", methods, methlen);
86916870 5805 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 5806 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 5807 }
65a22376 5808
51470298 5809 s->method = 0;
5810 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 5811 s->need_pw = FALSE;
65a22376 5812
0405e71f 5813 /*
5814 * Most password/passphrase prompts will be
5815 * non-echoing, so we set this to 0 by default.
5816 * Exception is that some keyboard-interactive prompts
5817 * can be echoing, in which case we'll set this to 1.
5818 */
51470298 5819 s->echo = 0;
0405e71f 5820
51470298 5821 if (!s->method && s->can_pubkey &&
5822 agent_exists() && !s->tried_agent) {
1983e559 5823 /*
5824 * Attempt public-key authentication using Pageant.
5825 */
1983e559 5826 void *r;
51470298 5827 s->authed = FALSE;
1983e559 5828
51470298 5829 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5830 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 5831
51470298 5832 s->tried_agent = TRUE;
1983e559 5833
5834 logevent("Pageant is running. Requesting keys.");
5835
5836 /* Request the keys held by the agent. */
51470298 5837 PUT_32BIT(s->request, 1);
5838 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 5839 if (!agent_query(s->request, 5, &r, &s->responselen,
5840 ssh_agent_callback, ssh)) {
5841 do {
5842 crReturnV;
ff3187f6 5843 if (pktin) {
839f10db 5844 bombout(("Unexpected data from server while"
5845 " waiting for agent response"));
5846 crStopV;
5847 }
ff3187f6 5848 } while (pktin || inlen > 0);
839f10db 5849 r = ssh->agent_response;
5850 s->responselen = ssh->agent_response_len;
5851 }
51470298 5852 s->response = (unsigned char *) r;
5853 if (s->response && s->responselen >= 5 &&
5854 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5855 s->p = s->response + 5;
5856 s->nkeys = GET_32BIT(s->p);
5857 s->p += 4;
32874aea 5858 {
5859 char buf[64];
51470298 5860 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 5861 logevent(buf);
5862 }
51470298 5863 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 5864 void *vret;
1983e559 5865
32874aea 5866 {
5867 char buf[64];
51470298 5868 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 5869 logevent(buf);
5870 }
51470298 5871 s->pklen = GET_32BIT(s->p);
5872 s->p += 4;
5873 if (s->publickey_blob &&
5874 s->pklen == s->publickey_bloblen &&
5875 !memcmp(s->p, s->publickey_blob,
5876 s->publickey_bloblen)) {
396778f1 5877 logevent("This key matches configured key file");
51470298 5878 s->tried_pubkey_config = 1;
396778f1 5879 }
d8baa528 5880 s->pkblob = (char *)s->p;
51470298 5881 s->p += s->pklen;
5882 s->alglen = GET_32BIT(s->pkblob);
5883 s->alg = s->pkblob + 4;
5884 s->commentlen = GET_32BIT(s->p);
5885 s->p += 4;
d8baa528 5886 s->commentp = (char *)s->p;
51470298 5887 s->p += s->commentlen;
ff3187f6 5888 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5889 ssh2_pkt_addstring(s->pktout, s->username);
5890 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5891 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5892 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
5893 ssh2_pkt_addstring_start(s->pktout);
5894 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5895 ssh2_pkt_addstring_start(s->pktout);
5896 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5897 ssh2_pkt_send(ssh, s->pktout);
5898
5899 crWaitUntilV(pktin);
5900 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 5901 logevent("Key refused");
5902 continue;
5903 }
5904
32874aea 5905 if (flags & FLAG_VERBOSE) {
51470298 5906 c_write_str(ssh, "Authenticating with "
5907 "public key \"");
5908 c_write(ssh, s->commentp, s->commentlen);
5909 c_write_str(ssh, "\" from agent\r\n");
32874aea 5910 }
1983e559 5911
5912 /*
5913 * Server is willing to accept the key.
5914 * Construct a SIGN_REQUEST.
5915 */
ff3187f6 5916 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5917 ssh2_pkt_addstring(s->pktout, s->username);
5918 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5919 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5920 ssh2_pkt_addbool(s->pktout, TRUE);
5921 ssh2_pkt_addstring_start(s->pktout);
5922 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5923 ssh2_pkt_addstring_start(s->pktout);
5924 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5925
5926 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 5927 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5928 s->siglen -= 4;
51470298 5929 s->len = 1; /* message type */
5930 s->len += 4 + s->pklen; /* key blob */
5931 s->len += 4 + s->siglen; /* data to sign */
5932 s->len += 4; /* flags */
3d88e64d 5933 s->agentreq = snewn(4 + s->len, char);
51470298 5934 PUT_32BIT(s->agentreq, s->len);
5935 s->q = s->agentreq + 4;
5936 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5937 PUT_32BIT(s->q, s->pklen);
5938 s->q += 4;
5939 memcpy(s->q, s->pkblob, s->pklen);
5940 s->q += s->pklen;
5941 PUT_32BIT(s->q, s->siglen);
5942 s->q += 4;
1983e559 5943 /* Now the data to be signed... */
dda87a28 5944 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5945 PUT_32BIT(s->q, 20);
5946 s->q += 4;
5947 }
51470298 5948 memcpy(s->q, ssh->v2_session_id, 20);
5949 s->q += 20;
ff3187f6 5950 memcpy(s->q, s->pktout->data + 5,
5951 s->pktout->length - 5);
5952 s->q += s->pktout->length - 5;
1983e559 5953 /* And finally the (zero) flags word. */
51470298 5954 PUT_32BIT(s->q, 0);
839f10db 5955 if (!agent_query(s->agentreq, s->len + 4,
5956 &vret, &s->retlen,
5957 ssh_agent_callback, ssh)) {
5958 do {
5959 crReturnV;
ff3187f6 5960 if (pktin) {
839f10db 5961 bombout(("Unexpected data from server"
5962 " while waiting for agent"
5963 " response"));
5964 crStopV;
5965 }
ff3187f6 5966 } while (pktin || inlen > 0);
839f10db 5967 vret = ssh->agent_response;
5968 s->retlen = ssh->agent_response_len;
5969 }
51470298 5970 s->ret = vret;
5971 sfree(s->agentreq);
5972 if (s->ret) {
5973 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 5974 logevent("Sending Pageant's response");
ff3187f6 5975 ssh2_add_sigblob(ssh, s->pktout,
5976 s->pkblob, s->pklen,
51470298 5977 s->ret + 9,
5978 GET_32BIT(s->ret + 5));
ff3187f6 5979 ssh2_pkt_send(ssh, s->pktout);
51470298 5980 s->authed = TRUE;
1983e559 5981 break;
5982 } else {
32874aea 5983 logevent
5984 ("Pageant failed to answer challenge");
51470298 5985 sfree(s->ret);
1983e559 5986 }
5987 }
5988 }
51470298 5989 if (s->authed)
1983e559 5990 continue;
5991 }
29b1d0b3 5992 sfree(s->response);
1983e559 5993 }
5994
51470298 5995 if (!s->method && s->can_pubkey && s->publickey_blob
5996 && !s->tried_pubkey_config) {
1408a877 5997 unsigned char *pub_blob;
5998 char *algorithm, *comment;
5999 int pub_blob_len;
65a22376 6000
51470298 6001 s->tried_pubkey_config = TRUE;
65a22376 6002
51470298 6003 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6004 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6005
65a22376 6006 /*
1408a877 6007 * Try the public key supplied in the configuration.
6008 *
6009 * First, offer the public blob to see if the server is
6010 * willing to accept it.
65a22376 6011 */
d8baa528 6012 pub_blob =
9a30e26b 6013 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6014 &algorithm,
222d54dc 6015 &pub_blob_len,
6016 NULL);
1408a877 6017 if (pub_blob) {
ff3187f6 6018 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6019 ssh2_pkt_addstring(s->pktout, s->username);
6020 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6021 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6022 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6023 ssh2_pkt_addstring(s->pktout, algorithm);
6024 ssh2_pkt_addstring_start(s->pktout);
6025 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6026 pub_blob_len);
ff3187f6 6027 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6028 logevent("Offered public key");
1408a877 6029
ff3187f6 6030 crWaitUntilV(pktin);
6031 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6032 s->gotit = TRUE;
6033 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6034 continue; /* key refused; give up on it */
1408a877 6035 }
65a22376 6036
1408a877 6037 logevent("Offer of public key accepted");
65a22376 6038 /*
1408a877 6039 * Actually attempt a serious authentication using
6040 * the key.
65a22376 6041 */
9a30e26b 6042 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6043 sprintf(s->pwprompt,
32874aea 6044 "Passphrase for key \"%.100s\": ",
6045 comment);
51470298 6046 s->need_pw = TRUE;
1408a877 6047 } else {
51470298 6048 s->need_pw = FALSE;
1408a877 6049 }
4e520718 6050 if (flags & FLAG_VERBOSE) {
6051 c_write_str(ssh, "Authenticating with public key \"");
6052 c_write_str(ssh, comment);
6053 c_write_str(ssh, "\"\r\n");
6054 }
51470298 6055 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6056 }
1408a877 6057 }
6058
51470298 6059 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
6060 s->method = AUTH_KEYBOARD_INTERACTIVE;
6061 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6062 s->tried_keyb_inter = TRUE;
af659722 6063
51470298 6064 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6065 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6066
ff3187f6 6067 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6068 ssh2_pkt_addstring(s->pktout, s->username);
6069 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6070 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6071 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6072 ssh2_pkt_addstring(s->pktout, "");
6073 ssh2_pkt_send(ssh, s->pktout);
6074
6075 crWaitUntilV(pktin);
6076 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6077 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6078 s->gotit = TRUE;
af659722 6079 logevent("Keyboard-interactive authentication refused");
51470298 6080 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 6081 continue;
6082 }
6083
51470298 6084 s->kbd_inter_running = TRUE;
6085 s->curr_prompt = 0;
af659722 6086 }
6087
51470298 6088 if (s->kbd_inter_running) {
6089 s->method = AUTH_KEYBOARD_INTERACTIVE;
6090 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6091 s->tried_keyb_inter = TRUE;
af659722 6092
51470298 6093 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6094 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6095
51470298 6096 if (s->curr_prompt == 0) {
45068b27 6097 /*
6098 * We've got a fresh USERAUTH_INFO_REQUEST.
6099 * Display header data, and start going through
6100 * the prompts.
6101 */
6102 char *name, *inst, *lang;
6103 int name_len, inst_len, lang_len;
6104
ff3187f6 6105 ssh_pkt_getstring(pktin, &name, &name_len);
6106 ssh_pkt_getstring(pktin, &inst, &inst_len);
6107 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6108 if (name_len > 0) {
51470298 6109 c_write_untrusted(ssh, name, name_len);
6110 c_write_str(ssh, "\r\n");
45068b27 6111 }
6112 if (inst_len > 0) {
51470298 6113 c_write_untrusted(ssh, inst, inst_len);
6114 c_write_str(ssh, "\r\n");
45068b27 6115 }
ff3187f6 6116 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6117 }
af659722 6118
45068b27 6119 /*
6120 * If there are prompts remaining in the packet,
6121 * display one and get a response.
6122 */
51470298 6123 if (s->curr_prompt < s->num_prompts) {
45068b27 6124 char *prompt;
6125 int prompt_len;
af659722 6126
ff3187f6 6127 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6128 if (prompt_len > 0) {
85fdbe25 6129 static const char trunc[] = "<prompt truncated>: ";
6130 static const int prlen = sizeof(s->pwprompt) -
6131 lenof(trunc);
6132 if (prompt_len > prlen) {
6133 memcpy(s->pwprompt, prompt, prlen);
6134 strcpy(s->pwprompt + prlen, trunc);
6135 } else {
6136 memcpy(s->pwprompt, prompt, prompt_len);
6137 s->pwprompt[prompt_len] = '\0';
6138 }
45068b27 6139 } else {
51470298 6140 strcpy(s->pwprompt,
45068b27 6141 "<server failed to send prompt>: ");
6142 }
ff3187f6 6143 s->echo = ssh2_pkt_getbool(pktin);
51470298 6144 s->need_pw = TRUE;
45068b27 6145 } else
51470298 6146 s->need_pw = FALSE;
af659722 6147 }
6148
51470298 6149 if (!s->method && s->can_passwd) {
6150 s->method = AUTH_PASSWORD;
6151 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6152 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6153 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6154 ssh->savedhost);
6155 s->need_pw = TRUE;
1408a877 6156 }
6157
51470298 6158 if (s->need_pw) {
fa17a66e 6159 if (ssh_get_line) {
51470298 6160 if (!ssh_get_line(s->pwprompt, s->password,
6161 sizeof(s->password), TRUE)) {
1408a877 6162 /*
fa17a66e 6163 * get_line failed to get a password (for
6164 * example because one was supplied on the
6165 * command line which has already failed to
6166 * work). Terminate.
1408a877 6167 */
ff3187f6 6168 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6169 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6170 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6171 " to try");
ff3187f6 6172 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6173 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6174 logevent("Unable to authenticate");
a8327734 6175 connection_fatal(ssh->frontend,
6176 "Unable to authenticate");
3bb2f322 6177 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6178 crStopV;
1408a877 6179 }
6180 } else {
51470298 6181 int ret; /* need not be saved across crReturn */
6182 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6183 ssh->send_ok = 1;
1408a877 6184
51470298 6185 setup_userpass_input(ssh, s->password,
6186 sizeof(s->password), s->echo);
0405e71f 6187 do {
ff3187f6 6188 crWaitUntilV(!pktin);
51470298 6189 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6190 } while (ret == 0);
6191 if (ret < 0)
6192 cleanup_exit(0);
51470298 6193 c_write_str(ssh, "\r\n");
65a22376 6194 }
65a22376 6195 }
65a22376 6196
51470298 6197 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6198 /*
6199 * We have our passphrase. Now try the actual authentication.
6200 */
6201 struct ssh2_userkey *key;
222d54dc 6202 const char *error = NULL;
65a22376 6203
222d54dc 6204 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6205 &error);
1408a877 6206 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6207 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6208 c_write_str(ssh, "Wrong passphrase\r\n");
6209 s->tried_pubkey_config = FALSE;
1408a877 6210 } else {
222d54dc 6211 c_write_str(ssh, "Unable to load private key (");
6212 c_write_str(ssh, error);
6213 c_write_str(ssh, ")\r\n");
51470298 6214 s->tried_pubkey_config = TRUE;
1408a877 6215 }
6216 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6217 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6218 ssh2_pkt_addstring(s->pktout, s->username);
6219 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6220 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6221 ssh2_pkt_send(ssh, s->pktout);
51470298 6222 s->type = AUTH_TYPE_NONE;
1408a877 6223 } else {
1dd353b5 6224 unsigned char *pkblob, *sigblob, *sigdata;
6225 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6226 int p;
65a22376 6227
1408a877 6228 /*
6229 * We have loaded the private key and the server
6230 * has announced that it's willing to accept it.
6231 * Hallelujah. Generate a signature and send it.
6232 */
ff3187f6 6233 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6234 ssh2_pkt_addstring(s->pktout, s->username);
6235 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6236 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6237 ssh2_pkt_addbool(s->pktout, TRUE);
6238 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6239 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6240 ssh2_pkt_addstring_start(s->pktout);
6241 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6242
6243 /*
6244 * The data to be signed is:
6245 *
6246 * string session-id
6247 *
6248 * followed by everything so far placed in the
6249 * outgoing packet.
6250 */
ff3187f6 6251 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6252 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6253 sigdata_len -= 4;
92d60585 6254 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6255 p = 0;
6256 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6257 PUT_32BIT(sigdata+p, 20);
6258 p += 4;
6259 }
6260 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6261 memcpy(sigdata+p, s->pktout->data + 5,
6262 s->pktout->length - 5);
6263 p += s->pktout->length - 5;
dda87a28 6264 assert(p == sigdata_len);
d8baa528 6265 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6266 sigdata_len, &sigblob_len);
ff3187f6 6267 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6268 sigblob, sigblob_len);
6269 sfree(pkblob);
6270 sfree(sigblob);
1408a877 6271 sfree(sigdata);
6272
ff3187f6 6273 ssh2_pkt_send(ssh, s->pktout);
51470298 6274 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6275 key->alg->freekey(key->data);
1408a877 6276 }
51470298 6277 } else if (s->method == AUTH_PASSWORD) {
65a22376 6278 /*
1408a877 6279 * We send the password packet lumped tightly together with
6280 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6281 * string long enough to make the total length of the two
6282 * packets constant. This should ensure that a passive
6283 * listener doing traffic analyis can't work out the length
6284 * of the password.
6285 *
6286 * For this to work, we need an assumption about the
6287 * maximum length of the password packet. I think 256 is
6288 * pretty conservative. Anyone using a password longer than
6289 * that probably doesn't have much to worry about from
6290 * people who find out how long their password is!
65a22376 6291 */
ff3187f6 6292 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6293 ssh2_pkt_addstring(s->pktout, s->username);
6294 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6295 ssh2_pkt_addstring(s->pktout, "password");
6296 ssh2_pkt_addbool(s->pktout, FALSE);
6297 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6298 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 6299 memset(s->password, 0, sizeof(s->password));
ff3187f6 6300 end_log_omission(ssh, s->pktout);
6301 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6302 /*
1408a877 6303 * We'll include a string that's an exact multiple of the
6304 * cipher block size. If the cipher is NULL for some
6305 * reason, we don't do this trick at all because we gain
6306 * nothing by it.
65a22376 6307 */
51470298 6308 if (ssh->cscipher) {
32874aea 6309 int stringlen, i;
6310
51470298 6311 stringlen = (256 - ssh->deferred_len);
6312 stringlen += ssh->cscipher->blksize - 1;
6313 stringlen -= (stringlen % ssh->cscipher->blksize);
6314 if (ssh->cscomp) {
32874aea 6315 /*
6316 * Temporarily disable actual compression,
6317 * so we can guarantee to get this string
6318 * exactly the length we want it. The
6319 * compression-disabling routine should
6320 * return an integer indicating how many
6321 * bytes we should adjust our string length
6322 * by.
6323 */
5366aed8 6324 stringlen -=
6325 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 6326 }
ff3187f6 6327 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6328 ssh2_pkt_addstring_start(s->pktout);
6e9e9520 6329 for (i = 0; i < stringlen; i++) {
32874aea 6330 char c = (char) random_byte();
ff3187f6 6331 ssh2_pkt_addstring_data(s->pktout, &c, 1);
65a22376 6332 }
ff3187f6 6333 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6334 }
51470298 6335 ssh_pkt_defersend(ssh);
0d43337a 6336 logevent("Sent password");
51470298 6337 s->type = AUTH_TYPE_PASSWORD;
6338 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6339 if (s->curr_prompt == 0) {
ff3187f6 6340 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6341 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 6342 }
51470298 6343 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 6344 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6345 ssh2_pkt_addstring(s->pktout, s->password);
51470298 6346 memset(s->password, 0, sizeof(s->password));
ff3187f6 6347 end_log_omission(ssh, s->pktout);
51470298 6348 s->curr_prompt++;
45068b27 6349 }
51470298 6350 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 6351 ssh2_pkt_send(ssh, s->pktout);
45068b27 6352 } else {
6353 /*
6354 * If there are prompts remaining, we set
6355 * `gotit' so that we won't attempt to get
6356 * another packet. Then we go back round the
6357 * loop and will end up retrieving another
6358 * prompt out of the existing packet. Funky or
6359 * what?
6360 */
51470298 6361 s->gotit = TRUE;
45068b27 6362 }
51470298 6363 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 6364 } else {
51470298 6365 c_write_str(ssh, "No supported authentication methods"
6366 " left to try!\r\n");
6367 logevent("No supported authentications offered."
6368 " Disconnecting");
ff3187f6 6369 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6370 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6371 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 6372 " methods available");
ff3187f6 6373 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6374 ssh2_pkt_send_noqueue(ssh, s->pktout);
3bb2f322 6375 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6376 crStopV;
65a22376 6377 }
65a22376 6378 }
51470298 6379 } while (!s->we_are_in);
7cca0d81 6380
6381 /*
6382 * Now we're authenticated for the connection protocol. The
6383 * connection protocol will automatically have started at this
6384 * point; there's no need to send SERVICE_REQUEST.
6385 */
6386
0ed48730 6387 ssh->channels = newtree234(ssh_channelcmp);
6388
7cca0d81 6389 /*
b09eaa88 6390 * Set up handlers for some connection protocol messages, so we
6391 * don't have to handle them repeatedly in this coroutine.
6392 */
6393 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6394 ssh2_msg_channel_window_adjust;
51df0ab5 6395 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6396 ssh2_msg_global_request;
b09eaa88 6397
6398 /*
0ed48730 6399 * Create the main session channel.
7cca0d81 6400 */
0ed48730 6401 if (!ssh->cfg.ssh_no_shell) {
6402 ssh->mainchan = snew(struct ssh_channel);
6403 ssh->mainchan->ssh = ssh;
6404 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 6405 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6406 ssh2_pkt_addstring(s->pktout, "session");
6407 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 6408 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 6409 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6410 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6411 ssh2_pkt_send(ssh, s->pktout);
6412 crWaitUntilV(pktin);
6413 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 6414 bombout(("Server refused to open a session"));
6415 crStopV;
6416 /* FIXME: error data comes back in FAILURE packet */
6417 }
ff3187f6 6418 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 6419 bombout(("Server's channel confirmation cited wrong channel"));
6420 crStopV;
6421 }
ff3187f6 6422 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 6423 ssh->mainchan->type = CHAN_MAINSESSION;
6424 ssh->mainchan->closes = 0;
ff3187f6 6425 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6426 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 6427 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6428 add234(ssh->channels, ssh->mainchan);
62638676 6429 update_specials_menu(ssh->frontend);
0ed48730 6430 logevent("Opened channel for session");
6431 } else
6432 ssh->mainchan = NULL;
7cca0d81 6433
6434 /*
51df0ab5 6435 * Now we have a channel, make dispatch table entries for
6436 * general channel-based messages.
6437 */
6438 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6439 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6440 ssh2_msg_channel_data;
6441 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6442 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6443 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6444 ssh2_msg_channel_open_confirmation;
6445 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6446 ssh2_msg_channel_open_failure;
6447 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6448 ssh2_msg_channel_request;
6449 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6450 ssh2_msg_channel_open;
6451
6452 /*
783415f8 6453 * Potentially enable X11 forwarding.
6454 */
0ed48730 6455 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 6456 char proto[20], data[64];
6457 logevent("Requesting X11 forwarding");
302121de 6458 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 6459 data, sizeof(data), ssh->cfg.x11_auth);
6460 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 6461 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6462 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6463 ssh2_pkt_addstring(s->pktout, "x11-req");
6464 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6465 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6466 ssh2_pkt_addstring(s->pktout, proto);
6467 ssh2_pkt_addstring(s->pktout, data);
6468 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6469 ssh2_pkt_send(ssh, s->pktout);
32874aea 6470
b09eaa88 6471 crWaitUntilV(pktin);
32874aea 6472
ff3187f6 6473 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6474 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6475 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 6476 " packet type %d", pktin->type));
7ffdbc1a 6477 crStopV;
32874aea 6478 }
6479 logevent("X11 forwarding refused");
6480 } else {
6481 logevent("X11 forwarding enabled");
51470298 6482 ssh->X11_fwd_enabled = TRUE;
32874aea 6483 }
783415f8 6484 }
6485
6486 /*
bc240b21 6487 * Enable port forwardings.
6488 */
6489 {
bc240b21 6490 char type;
6491 int n;
a4fc0d74 6492 int sport,dport,sserv,dserv;
6ee9b735 6493 char sports[256], dports[256], saddr[256], host[256];
bc240b21 6494
51470298 6495 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 6496 /* Add port forwardings. */
86916870 6497 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 6498 while (*ssh->portfwd_strptr) {
6499 type = *ssh->portfwd_strptr++;
6ee9b735 6500 saddr[0] = '\0';
bc240b21 6501 n = 0;
6ee9b735 6502 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
6503 if (*ssh->portfwd_strptr == ':') {
6504 /*
6505 * We've seen a colon in the middle of the
6506 * source port number. This means that
6507 * everything we've seen until now is the
6508 * source _address_, so we'll move it into
6509 * saddr and start sports from the beginning
6510 * again.
6511 */
6512 ssh->portfwd_strptr++;
6513 sports[n] = '\0';
6514 strcpy(saddr, sports);
6515 n = 0;
6516 }
6517 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
6518 }
bc240b21 6519 sports[n] = 0;
820ebe3b 6520 if (type != 'D') {
6521 if (*ssh->portfwd_strptr == '\t')
6522 ssh->portfwd_strptr++;
6523 n = 0;
6524 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
6525 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
6526 }
6527 host[n] = 0;
6528 if (*ssh->portfwd_strptr == ':')
6529 ssh->portfwd_strptr++;
6530 n = 0;
6531 while (*ssh->portfwd_strptr) {
6532 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
6533 }
6534 dports[n] = 0;
51470298 6535 ssh->portfwd_strptr++;
820ebe3b 6536 dport = atoi(dports);
6537 dserv = 0;
6538 if (dport == 0) {
6539 dserv = 1;
6540 dport = net_service_lookup(dports);
6541 if (!dport) {
6542 logeventf(ssh, "Service lookup failed for destination"
6543 " port \"%s\"", dports);
6544 }
a4fc0d74 6545 }
820ebe3b 6546 } else {
6547 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 6548 dport = dserv = -1;
7d5b0f4d 6549 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 6550 }
bc240b21 6551 sport = atoi(sports);
a4fc0d74 6552 sserv = 0;
6553 if (sport == 0) {
6554 sserv = 1;
68a49acb 6555 sport = net_service_lookup(sports);
6556 if (!sport) {
57356d63 6557 logeventf(ssh, "Service lookup failed for source"
6558 " port \"%s\"", sports);
a4fc0d74 6559 }
6560 }
bc240b21 6561 if (sport && dport) {
94ab1ddf 6562 /* Set up a description of the source port. */
49b8f9c4 6563 static char *sportdesc;
6564 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
94ab1ddf 6565 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
6566 (int)(*saddr?1:0), ":",
6567 (int)(sserv ? strlen(sports) : 0), sports,
6568 sserv, "(", sport, sserv, ")");
bc240b21 6569 if (type == 'L') {
94ab1ddf 6570 /* Verbose description of the destination port */
6571 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
6572 host,
6573 (int)(dserv ? strlen(dports) : 0), dports,
6574 dserv, "(", dport, dserv, ")");
6575 const char *err = pfd_addforward(host, dport,
6576 *saddr ? saddr : NULL,
6577 sport, ssh, &ssh->cfg);
6578 if (err) {
6579 logeventf(ssh, "Local port %s forward to %s"
6580 " failed: %s", sportdesc, dportdesc, err);
6581 } else {
6582 logeventf(ssh, "Local port %s forwarding to %s",
6583 sportdesc, dportdesc);
6584 }
6585 sfree(dportdesc);
820ebe3b 6586 } else if (type == 'D') {
94ab1ddf 6587 const char *err = pfd_addforward(NULL, -1,
6588 *saddr ? saddr : NULL,
6589 sport, ssh, &ssh->cfg);
6590 if (err) {
6591 logeventf(ssh, "Local port %s SOCKS dynamic forward"
6592 " setup failed: %s", sportdesc, err);
6593 } else {
6594 logeventf(ssh, "Local port %s doing SOCKS"
6595 " dynamic forwarding", sportdesc);
6596 }
bc240b21 6597 } else {
6598 struct ssh_rportfwd *pf;
3d88e64d 6599 pf = snew(struct ssh_rportfwd);
bc240b21 6600 strcpy(pf->dhost, host);
6601 pf->dport = dport;
6602 pf->sport = sport;
51470298 6603 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 6604 logeventf(ssh, "Duplicate remote port forwarding"
6605 " to %s:%d", host, dport);
bc240b21 6606 sfree(pf);
6607 } else {
94ab1ddf 6608 logeventf(ssh, "Requesting remote port %s"
57356d63 6609 " forward to %s:%.*s%.*s%d%.*s",
94ab1ddf 6610 sportdesc,
57356d63 6611 host,
6612 (int)(dserv ? strlen(dports) : 0), dports,
6613 dserv, "(", dport, dserv, ")");
ff3187f6 6614 s->pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
6615 ssh2_pkt_addstring(s->pktout, "tcpip-forward");
6616 ssh2_pkt_addbool(s->pktout, 1);/* want reply */
49b8f9c4 6617 if (*saddr) {
ff3187f6 6618 ssh2_pkt_addstring(s->pktout, saddr);
49b8f9c4 6619 } else if (ssh->cfg.rport_acceptall) {
ff3187f6 6620 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
49b8f9c4 6621 } else {
ff3187f6 6622 ssh2_pkt_addstring(s->pktout, "127.0.0.1");
49b8f9c4 6623 }
ff3187f6 6624 ssh2_pkt_adduint32(s->pktout, sport);
6625 ssh2_pkt_send(ssh, s->pktout);
bc240b21 6626
b09eaa88 6627 crWaitUntilV(pktin);
bc240b21 6628
ff3187f6 6629 if (pktin->type != SSH2_MSG_REQUEST_SUCCESS) {
6630 if (pktin->type != SSH2_MSG_REQUEST_FAILURE) {
6b5cf8b4 6631 bombout(("Unexpected response to port "
c9886e66 6632 "forwarding request: packet type %d",
ff3187f6 6633 pktin->type));
7ffdbc1a 6634 crStopV;
bc240b21 6635 }
6636 logevent("Server refused this port forwarding");
6637 } else {
6638 logevent("Remote port forwarding enabled");
6639 }
6640 }
6641 }
94ab1ddf 6642 sfree(sportdesc);
bc240b21 6643 }
6644 }
6645 }
6646
6647 /*
36c2a3e9 6648 * Potentially enable agent forwarding.
6649 */
0ed48730 6650 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6651 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6652 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6653 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6654 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6655 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6656 ssh2_pkt_send(ssh, s->pktout);
32874aea 6657
b09eaa88 6658 crWaitUntilV(pktin);
32874aea 6659
ff3187f6 6660 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6661 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6662 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6663 " packet type %d", pktin->type));
7ffdbc1a 6664 crStopV;
32874aea 6665 }
6666 logevent("Agent forwarding refused");
6667 } else {
6668 logevent("Agent forwarding enabled");
51470298 6669 ssh->agentfwd_enabled = TRUE;
32874aea 6670 }
36c2a3e9 6671 }
6672
6673 /*
7cca0d81 6674 * Now allocate a pty for the session.
6675 */
0ed48730 6676 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6677 /* Unpick the terminal-speed string. */
6678 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6679 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6680 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6681 /* Build the pty request. */
ff3187f6 6682 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6683 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6684 ssh2_pkt_addstring(s->pktout, "pty-req");
6685 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6686 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6687 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6688 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6689 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6690 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6691 ssh2_pkt_addstring_start(s->pktout);
6692 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6693 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6694 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6695 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6696 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6697 ssh2_pkt_send(ssh, s->pktout);
51470298 6698 ssh->state = SSH_STATE_INTERMED;
32874aea 6699
b09eaa88 6700 crWaitUntilV(pktin);
32874aea 6701
ff3187f6 6702 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6703 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6704 bombout(("Unexpected response to pty request:"
ff3187f6 6705 " packet type %d", pktin->type));
7ffdbc1a 6706 crStopV;
32874aea 6707 }
51470298 6708 c_write_str(ssh, "Server refused to allocate pty\r\n");
6709 ssh->editing = ssh->echoing = 1;
32874aea 6710 } else {
a5dd8467 6711 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 6712 ssh->ospeed, ssh->ispeed);
32874aea 6713 }
0965bee0 6714 } else {
51470298 6715 ssh->editing = ssh->echoing = 1;
7cca0d81 6716 }
6717
6718 /*
73feed4f 6719 * Send environment variables.
6720 *
6721 * Simplest thing here is to send all the requests at once, and
6722 * then wait for a whole bunch of successes or failures.
6723 */
6724 if (ssh->mainchan && *ssh->cfg.environmt) {
6725 char *e = ssh->cfg.environmt;
6726 char *var, *varend, *val;
6727
6728 s->num_env = 0;
6729
6730 while (*e) {
6731 var = e;
6732 while (*e && *e != '\t') e++;
6733 varend = e;
6734 if (*e == '\t') e++;
6735 val = e;
6736 while (*e) e++;
6737 e++;
6738
ff3187f6 6739 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6740 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6741 ssh2_pkt_addstring(s->pktout, "env");
6742 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6743 ssh2_pkt_addstring_start(s->pktout);
6744 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6745 ssh2_pkt_addstring(s->pktout, val);
6746 ssh2_pkt_send(ssh, s->pktout);
73feed4f 6747
6748 s->num_env++;
6749 }
6750
6751 logeventf(ssh, "Sent %d environment variables", s->num_env);
6752
6753 s->env_ok = 0;
6754 s->env_left = s->num_env;
6755
6756 while (s->env_left > 0) {
b09eaa88 6757 crWaitUntilV(pktin);
73feed4f 6758
ff3187f6 6759 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6760 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 6761 bombout(("Unexpected response to environment request:"
ff3187f6 6762 " packet type %d", pktin->type));
73feed4f 6763 crStopV;
6764 }
6765 } else {
6766 s->env_ok++;
6767 }
6768
6769 s->env_left--;
6770 }
6771
6772 if (s->env_ok == s->num_env) {
6773 logevent("All environment variables successfully set");
6774 } else if (s->env_ok == 0) {
6775 logevent("All environment variables refused");
6776 c_write_str(ssh, "Server refused to set environment variables\r\n");
6777 } else {
6778 logeventf(ssh, "%d environment variables refused",
6779 s->num_env - s->env_ok);
6780 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6781 }
6782 }
6783
6784 /*
fd5e5847 6785 * Start a shell or a remote command. We may have to attempt
6786 * this twice if the config data has provided a second choice
6787 * of command.
7cca0d81 6788 */
0ed48730 6789 if (ssh->mainchan) while (1) {
fd5e5847 6790 int subsys;
6791 char *cmd;
6792
51470298 6793 if (ssh->fallback_cmd) {
86916870 6794 subsys = ssh->cfg.ssh_subsys2;
6795 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 6796 } else {
86916870 6797 subsys = ssh->cfg.ssh_subsys;
6798 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 6799 }
6800
ff3187f6 6801 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6802 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 6803 if (subsys) {
ff3187f6 6804 ssh2_pkt_addstring(s->pktout, "subsystem");
6805 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6806 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6807 } else if (*cmd) {
ff3187f6 6808 ssh2_pkt_addstring(s->pktout, "exec");
6809 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6810 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6811 } else {
ff3187f6 6812 ssh2_pkt_addstring(s->pktout, "shell");
6813 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 6814 }
ff3187f6 6815 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 6816
6817 crWaitUntilV(pktin);
6818
ff3187f6 6819 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6820 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6821 bombout(("Unexpected response to shell/command request:"
ff3187f6 6822 " packet type %d", pktin->type));
7ffdbc1a 6823 crStopV;
fd5e5847 6824 }
6825 /*
6826 * We failed to start the command. If this is the
6827 * fallback command, we really are finished; if it's
6828 * not, and if the fallback command exists, try falling
6829 * back to it before complaining.
6830 */
86916870 6831 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 6832 logevent("Primary command failed; attempting fallback");
51470298 6833 ssh->fallback_cmd = TRUE;
fd5e5847 6834 continue;
6835 }
6b5cf8b4 6836 bombout(("Server refused to start a shell/command"));
7ffdbc1a 6837 crStopV;
fd5e5847 6838 } else {
6839 logevent("Started a shell/command");
32874aea 6840 }
fd5e5847 6841 break;
7cca0d81 6842 }
6843
51470298 6844 ssh->state = SSH_STATE_SESSION;
6845 if (ssh->size_needed)
6846 ssh_size(ssh, ssh->term_width, ssh->term_height);
6847 if (ssh->eof_needed)
6848 ssh_special(ssh, TS_EOF);
6e48c3fe 6849
7cca0d81 6850 /*
6851 * Transfer data!
6852 */
b9d7bcad 6853 if (ssh->ldisc)
6854 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 6855 if (ssh->mainchan)
6856 ssh->send_ok = 1;
7cca0d81 6857 while (1) {
e5574168 6858 crReturnV;
51470298 6859 s->try_send = FALSE;
ff3187f6 6860 if (pktin) {
2b7540a7 6861
51df0ab5 6862 /*
6863 * _All_ the connection-layer packets we expect to
6864 * receive are now handled by the dispatch table.
6865 * Anything that reaches here must be bogus.
6866 */
32874aea 6867
51df0ab5 6868 bombout(("Strange packet received: type %d", pktin->type));
6869 crStopV;
0ed48730 6870 } else if (ssh->mainchan) {
32874aea 6871 /*
6872 * We have spare data. Add it to the channel buffer.
6873 */
d8baa528 6874 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 6875 s->try_send = TRUE;
32874aea 6876 }
51470298 6877 if (s->try_send) {
32874aea 6878 int i;
6879 struct ssh_channel *c;
6880 /*
6881 * Try to send data on all channels if we can.
6882 */
51470298 6883 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 6884 int bufsize;
6885 if (c->closes)
6886 continue; /* don't send on closing channels */
6887 bufsize = ssh2_try_send(c);
5471d09a 6888 if (bufsize == 0) {
6889 switch (c->type) {
6890 case CHAN_MAINSESSION:
6891 /* stdin need not receive an unthrottle
6892 * notification since it will be polled */
6893 break;
6894 case CHAN_X11:
6895 x11_unthrottle(c->u.x11.s);
6896 break;
6897 case CHAN_AGENT:
6898 /* agent sockets are request/response and need no
6899 * buffer management */
6900 break;
6901 case CHAN_SOCKDATA:
6902 pfd_unthrottle(c->u.pfd.s);
6903 break;
6904 }
6905 }
6906 }
7cca0d81 6907 }
e5574168 6908 }
6909
6910 crFinishV;
6911}
6912
6913/*
b09eaa88 6914 * Handlers for SSH2 messages that might arrive at any moment.
6915 */
6916void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
6917{
6918 /* log reason code in disconnect message */
6919 char *buf, *msg;
6920 int nowlen, reason, msglen;
6921
6922 reason = ssh_pkt_getuint32(pktin);
6923 ssh_pkt_getstring(pktin, &msg, &msglen);
6924
6925 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
6926 buf = dupprintf("Received disconnect message (%s)",
6927 ssh2_disconnect_reasons[reason]);
6928 } else {
6929 buf = dupprintf("Received disconnect message (unknown"
6930 " type %d)", reason);
6931 }
6932 logevent(buf);
6933 sfree(buf);
6934 buf = dupprintf("Disconnection message text: %n%.*s",
6935 &nowlen, msglen, msg);
6936 logevent(buf);
6937 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
6938 reason,
6939 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
6940 ssh2_disconnect_reasons[reason] : "unknown",
6941 buf+nowlen));
6942 sfree(buf);
6943}
6944
6945void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
6946{
6947 /* log the debug message */
6948 char *buf, *msg;
6949 int msglen;
6950 int always_display;
6951
6952 /* XXX maybe we should actually take notice of this */
6953 always_display = ssh2_pkt_getbool(pktin);
6954 ssh_pkt_getstring(pktin, &msg, &msglen);
6955
6956 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
6957 logevent(buf);
6958 sfree(buf);
6959}
6960
6961void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
6962{
6963 struct Packet *pktout;
6964 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
6965 ssh2_pkt_adduint32(pktout, pktin->sequence);
6966 /*
6967 * UNIMPLEMENTED messages MUST appear in the same order as the
6968 * messages they respond to. Hence, never queue them.
6969 */
6970 ssh2_pkt_send_noqueue(ssh, pktout);
6971}
6972
6973/*
7cca0d81 6974 * Handle the top-level SSH2 protocol.
6975 */
b09eaa88 6976static void ssh2_protocol_setup(Ssh ssh)
6977{
6978 int i;
6979
6980 /*
6981 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
6982 */
6983 for (i = 0; i < 256; i++)
6984 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
6985
6986 /*
6987 * Any message we actually understand, we set to NULL so that
6988 * the coroutines will get it.
6989 */
6990 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
6991 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
6992 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
6993 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
6994 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
6995 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
6996 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
6997 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
6998 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
6999 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7000 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7001 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7002 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7003 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7004 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7005 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7006 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7007 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7008 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7009 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7010 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7011 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7012 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7013 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7014 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7015 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7016 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7017 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7018 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7019 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7020 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7021 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7022 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7023
7024 /*
7025 * These special message types we install handlers for.
7026 */
7027 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7028 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7029 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7030}
7031
9442dd57 7032static void ssh2_timer(void *ctx, long now)
7033{
7034 Ssh ssh = (Ssh)ctx;
7035
7036 if (!ssh->kex_in_progress &&
7037 now - ssh->next_rekey >= 0) {
7038 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7039 -1, NULL);
7040 }
7041}
7042
ff3187f6 7043static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7044 struct Packet *pktin)
7cca0d81 7045{
b09eaa88 7046 if (ssh->state == SSH_STATE_CLOSED)
7047 return;
7048
9442dd57 7049 if (pktin) {
7050 ssh->incoming_data_size += pktin->encrypted_len;
7051 if (!ssh->kex_in_progress &&
7052 ssh->incoming_data_size > MAX_DATA_BEFORE_REKEY)
7053 do_ssh2_transport(ssh, "Initiating key re-exchange "
7054 "(too much data received)", -1, NULL);
7055 }
7056
b09eaa88 7057 if (pktin && ssh->packet_dispatch[pktin->type]) {
7058 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7059 return;
b09eaa88 7060 }
7061
7062 if (!ssh->protocol_initial_phase_done ||
7063 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7064 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7065 !ssh->protocol_initial_phase_done) {
7066 ssh->protocol_initial_phase_done = TRUE;
7067 /*
7068 * Allow authconn to initialise itself.
7069 */
7070 do_ssh2_authconn(ssh, NULL, 0, NULL);
7071 }
7072 } else {
7073 do_ssh2_authconn(ssh, in, inlen, pktin);
7074 }
7cca0d81 7075}
7076
7077/*
8df7a775 7078 * Called to set up the connection.
374330e2 7079 *
7080 * Returns an error message, or NULL on success.
374330e2 7081 */
cbe2d68f 7082static const char *ssh_init(void *frontend_handle, void **backend_handle,
7083 Config *cfg,
79bf227b 7084 char *host, int port, char **realhost, int nodelay,
7085 int keepalive)
32874aea 7086{
cbe2d68f 7087 const char *p;
51470298 7088 Ssh ssh;
7089
3d88e64d 7090 ssh = snew(struct ssh_tag);
86916870 7091 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7092 ssh->version = 0; /* when not ready yet */
51470298 7093 ssh->s = NULL;
7094 ssh->cipher = NULL;
371e569c 7095 ssh->v1_cipher_ctx = NULL;
0183b242 7096 ssh->crcda_ctx = NULL;
51470298 7097 ssh->cscipher = NULL;
371e569c 7098 ssh->cs_cipher_ctx = NULL;
51470298 7099 ssh->sccipher = NULL;
371e569c 7100 ssh->sc_cipher_ctx = NULL;
51470298 7101 ssh->csmac = NULL;
a8327734 7102 ssh->cs_mac_ctx = NULL;
51470298 7103 ssh->scmac = NULL;
e0e1a00d 7104 ssh->sc_mac_ctx = NULL;
51470298 7105 ssh->cscomp = NULL;
5366aed8 7106 ssh->cs_comp_ctx = NULL;
51470298 7107 ssh->sccomp = NULL;
5366aed8 7108 ssh->sc_comp_ctx = NULL;
51470298 7109 ssh->kex = NULL;
389aa499 7110 ssh->kex_ctx = NULL;
51470298 7111 ssh->hostkey = NULL;
7112 ssh->exitcode = -1;
7113 ssh->state = SSH_STATE_PREPACKET;
7114 ssh->size_needed = FALSE;
7115 ssh->eof_needed = FALSE;
b9d7bcad 7116 ssh->ldisc = NULL;
a8327734 7117 ssh->logctx = NULL;
51470298 7118 ssh->deferred_send_data = NULL;
7119 ssh->deferred_len = 0;
7120 ssh->deferred_size = 0;
7121 ssh->fallback_cmd = 0;
7122 ssh->pkt_ctx = 0;
302121de 7123 ssh->x11auth = NULL;
be738459 7124 ssh->v1_compressing = FALSE;
51470298 7125 ssh->v2_outgoing_sequence = 0;
7126 ssh->ssh1_rdpkt_crstate = 0;
7127 ssh->ssh2_rdpkt_crstate = 0;
7128 ssh->do_ssh_init_crstate = 0;
7129 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7130 ssh->do_ssh1_connection_crstate = 0;
51470298 7131 ssh->do_ssh1_login_crstate = 0;
7132 ssh->do_ssh2_transport_crstate = 0;
7133 ssh->do_ssh2_authconn_crstate = 0;
7134 ssh->do_ssh_init_state = NULL;
7135 ssh->do_ssh1_login_state = NULL;
7136 ssh->do_ssh2_transport_state = NULL;
7137 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7138 ssh->mainchan = NULL;
968d2d92 7139 ssh->throttled_all = 0;
7140 ssh->v1_stdout_throttling = 0;
590f6a5f 7141 ssh->queue = NULL;
7142 ssh->queuelen = ssh->queuesize = 0;
7143 ssh->queueing = FALSE;
51470298 7144
7145 *backend_handle = ssh;
32874aea 7146
8f203108 7147#ifdef MSCRYPTOAPI
32874aea 7148 if (crypto_startup() == 0)
8f203108 7149 return "Microsoft high encryption pack not installed!";
7150#endif
374330e2 7151
51470298 7152 ssh->frontend = frontend_handle;
86916870 7153 ssh->term_width = ssh->cfg.width;
7154 ssh->term_height = ssh->cfg.height;
887035a5 7155
fabd1805 7156 ssh->channels = NULL;
7157 ssh->rportfwds = NULL;
7158
51470298 7159 ssh->send_ok = 0;
7160 ssh->editing = 0;
7161 ssh->echoing = 0;
7162 ssh->v1_throttle_count = 0;
7163 ssh->overall_bufsize = 0;
7164 ssh->fallback_cmd = 0;
8df7a775 7165
3648d4c5 7166 ssh->protocol = NULL;
7167
b09eaa88 7168 ssh->protocol_initial_phase_done = FALSE;
7169
39934deb 7170 ssh->pinger = NULL;
7171
9442dd57 7172 ssh->incoming_data_size = ssh->outgoing_data_size =
7173 ssh->deferred_data_size = 0L;
7174 ssh->kex_in_progress = FALSE;
7175
79bf227b 7176 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7177 if (p != NULL)
7178 return p;
374330e2 7179
5d17ccfc 7180 random_ref();
7181
374330e2 7182 return NULL;
7183}
7184
fabd1805 7185static void ssh_free(void *handle)
7186{
7187 Ssh ssh = (Ssh) handle;
7188 struct ssh_channel *c;
7189 struct ssh_rportfwd *pf;
7190
7191 if (ssh->v1_cipher_ctx)
7192 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7193 if (ssh->cs_cipher_ctx)
7194 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7195 if (ssh->sc_cipher_ctx)
7196 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7197 if (ssh->cs_mac_ctx)
7198 ssh->csmac->free_context(ssh->cs_mac_ctx);
7199 if (ssh->sc_mac_ctx)
7200 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7201 if (ssh->cs_comp_ctx) {
7202 if (ssh->cscomp)
7203 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7204 else
7205 zlib_compress_cleanup(ssh->cs_comp_ctx);
7206 }
7207 if (ssh->sc_comp_ctx) {
7208 if (ssh->sccomp)
7209 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7210 else
7211 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7212 }
fabd1805 7213 if (ssh->kex_ctx)
7214 dh_cleanup(ssh->kex_ctx);
7215 sfree(ssh->savedhost);
7216
590f6a5f 7217 while (ssh->queuelen-- > 0)
7218 ssh_free_packet(ssh->queue[ssh->queuelen]);
7219 sfree(ssh->queue);
7220
fabd1805 7221 if (ssh->channels) {
7222 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7223 switch (c->type) {
7224 case CHAN_X11:
7225 if (c->u.x11.s != NULL)
7226 x11_close(c->u.x11.s);
7227 break;
7228 case CHAN_SOCKDATA:
7229 if (c->u.pfd.s != NULL)
7230 pfd_close(c->u.pfd.s);
7231 break;
7232 }
7233 sfree(c);
7234 }
7235 freetree234(ssh->channels);
7236 }
7237
7238 if (ssh->rportfwds) {
7239 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7240 sfree(pf);
7241 freetree234(ssh->rportfwds);
7242 }
7243 sfree(ssh->deferred_send_data);
7244 if (ssh->x11auth)
7245 x11_free_auth(ssh->x11auth);
7246 sfree(ssh->do_ssh_init_state);
7247 sfree(ssh->do_ssh1_login_state);
7248 sfree(ssh->do_ssh2_transport_state);
7249 sfree(ssh->do_ssh2_authconn_state);
679539d7 7250 if (ssh->crcda_ctx) {
7251 crcda_free_context(ssh->crcda_ctx);
7252 ssh->crcda_ctx = NULL;
7253 }
fabd1805 7254 if (ssh->s)
36f94d1f 7255 ssh_do_close(ssh);
9442dd57 7256 expire_timer_context(ssh);
fabd1805 7257 sfree(ssh);
39934deb 7258 if (ssh->pinger)
7259 pinger_free(ssh->pinger);
5d17ccfc 7260
7261 random_unref();
fabd1805 7262}
7263
374330e2 7264/*
86916870 7265 * Reconfigure the SSH backend.
7266 *
7267 * Currently, this function does nothing very useful. In future,
7268 * however, we could do some handy things with it. For example, we
7269 * could make the port forwarding configurer active in the Change
7270 * Settings box, and this routine could close down existing
7271 * forwardings and open up new ones in response to changes.
7272 */
7273static void ssh_reconfig(void *handle, Config *cfg)
7274{
7275 Ssh ssh = (Ssh) handle;
39934deb 7276 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
86916870 7277 ssh->cfg = *cfg; /* STRUCTURE COPY */
7278}
7279
7280/*
374330e2 7281 * Called to send data down the Telnet connection.
7282 */
51470298 7283static int ssh_send(void *handle, char *buf, int len)
32874aea 7284{
51470298 7285 Ssh ssh = (Ssh) handle;
7286
7287 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7288 return 0;
374330e2 7289
d8baa528 7290 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7291
51470298 7292 return ssh_sendbuffer(ssh);
5471d09a 7293}
7294
7295/*
7296 * Called to query the current amount of buffered stdin data.
7297 */
51470298 7298static int ssh_sendbuffer(void *handle)
5471d09a 7299{
51470298 7300 Ssh ssh = (Ssh) handle;
5471d09a 7301 int override_value;
7302
51470298 7303 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7304 return 0;
7305
7306 /*
7307 * If the SSH socket itself has backed up, add the total backup
7308 * size on that to any individual buffer on the stdin channel.
7309 */
7310 override_value = 0;
51470298 7311 if (ssh->throttled_all)
7312 override_value = ssh->overall_bufsize;
5471d09a 7313
51470298 7314 if (ssh->version == 1) {
5471d09a 7315 return override_value;
51470298 7316 } else if (ssh->version == 2) {
7317 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7318 return override_value;
7319 else
51470298 7320 return (override_value +
7321 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7322 }
7323
7324 return 0;
374330e2 7325}
7326
7327/*
6e48c3fe 7328 * Called to set the size of the window from SSH's POV.
374330e2 7329 */
51470298 7330static void ssh_size(void *handle, int width, int height)
32874aea 7331{
51470298 7332 Ssh ssh = (Ssh) handle;
ff3187f6 7333 struct Packet *pktout;
51470298 7334
7335 ssh->term_width = width;
7336 ssh->term_height = height;
f278d6f8 7337
51470298 7338 switch (ssh->state) {
374330e2 7339 case SSH_STATE_BEFORE_SIZE:
3687d221 7340 case SSH_STATE_PREPACKET:
21248260 7341 case SSH_STATE_CLOSED:
374330e2 7342 break; /* do nothing */
7343 case SSH_STATE_INTERMED:
51470298 7344 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7345 break;
7346 case SSH_STATE_SESSION:
86916870 7347 if (!ssh->cfg.nopty) {
51470298 7348 if (ssh->version == 1) {
7349 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7350 PKT_INT, ssh->term_height,
7351 PKT_INT, ssh->term_width,
32874aea 7352 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7353 } else if (ssh->mainchan) {
ff3187f6 7354 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7355 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7356 ssh2_pkt_addstring(pktout, "window-change");
7357 ssh2_pkt_addbool(pktout, 0);
7358 ssh2_pkt_adduint32(pktout, ssh->term_width);
7359 ssh2_pkt_adduint32(pktout, ssh->term_height);
7360 ssh2_pkt_adduint32(pktout, 0);
7361 ssh2_pkt_adduint32(pktout, 0);
7362 ssh2_pkt_send(ssh, pktout);
32874aea 7363 }
7364 }
7365 break;
374330e2 7366 }
7367}
7368
7369/*
125105d1 7370 * Return a list of the special codes that make sense in this
7371 * protocol.
7372 */
7373static const struct telnet_special *ssh_get_specials(void *handle)
7374{
62638676 7375 static const struct telnet_special ignore_special[] = {
7376 {"IGNORE message", TS_NOP},
9442dd57 7377 {"Repeat key exchange", TS_REKEY},
62638676 7378 };
7379 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7380 {NULL, TS_SEP},
7381 {"Break", TS_BRK},
7382 /* These are the signal names defined by draft-ietf-secsh-connect-19.
7383 * They include all the ISO C signals, but are a subset of the POSIX
7384 * required signals. */
7385 {"SIGINT (Interrupt)", TS_SIGINT},
7386 {"SIGTERM (Terminate)", TS_SIGTERM},
7387 {"SIGKILL (Kill)", TS_SIGKILL},
7388 {"SIGQUIT (Quit)", TS_SIGQUIT},
7389 {"SIGHUP (Hangup)", TS_SIGHUP},
7390 {"More signals", TS_SUBMENU},
7391 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7392 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7393 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7394 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7395 {NULL, TS_EXITMENU}
62638676 7396 };
7397 static const struct telnet_special specials_end[] = {
6f2d0cde 7398 {NULL, TS_EXITMENU}
62638676 7399 };
7400 static struct telnet_special ssh_specials[lenof(ignore_special) +
7401 lenof(ssh2_session_specials) +
7402 lenof(specials_end)];
125105d1 7403 Ssh ssh = (Ssh) handle;
62638676 7404 int i = 0;
7405#define ADD_SPECIALS(name) \
7406 do { \
7407 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7408 memcpy(&ssh_specials[i], name, sizeof name); \
7409 i += lenof(name); \
7410 } while(0)
125105d1 7411
7412 if (ssh->version == 1) {
62638676 7413 /* Don't bother offering IGNORE if we've decided the remote
7414 * won't cope with it, since we wouldn't bother sending it if
7415 * asked anyway. */
7416 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7417 ADD_SPECIALS(ignore_special);
125105d1 7418 } else if (ssh->version == 2) {
62638676 7419 ADD_SPECIALS(ignore_special);
7420 if (ssh->mainchan)
7421 ADD_SPECIALS(ssh2_session_specials);
7422 } /* else we're not ready yet */
7423
7424 if (i) {
7425 ADD_SPECIALS(specials_end);
7426 return ssh_specials;
7427 } else {
125105d1 7428 return NULL;
62638676 7429 }
7430#undef ADD_SPECIALS
125105d1 7431}
7432
7433/*
6abbf9e3 7434 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7435 * can send an EOF and collect resulting output (e.g. `plink
7436 * hostname sort').
374330e2 7437 */
51470298 7438static void ssh_special(void *handle, Telnet_Special code)
32874aea 7439{
51470298 7440 Ssh ssh = (Ssh) handle;
ff3187f6 7441 struct Packet *pktout;
51470298 7442
6abbf9e3 7443 if (code == TS_EOF) {
51470298 7444 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7445 /*
7446 * Buffer the EOF in case we are pre-SESSION, so we can
7447 * send it as soon as we reach SESSION.
7448 */
7449 if (code == TS_EOF)
51470298 7450 ssh->eof_needed = TRUE;
32874aea 7451 return;
7452 }
51470298 7453 if (ssh->version == 1) {
7454 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7455 } else if (ssh->mainchan) {
ff3187f6 7456 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7457 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7458 ssh2_pkt_send(ssh, pktout);
32874aea 7459 }
7460 logevent("Sent EOF message");
125105d1 7461 } else if (code == TS_PING || code == TS_NOP) {
51470298 7462 if (ssh->state == SSH_STATE_CLOSED
7463 || ssh->state == SSH_STATE_PREPACKET) return;
7464 if (ssh->version == 1) {
7465 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7466 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7467 } else {
ff3187f6 7468 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7469 ssh2_pkt_addstring_start(pktout);
590f6a5f 7470 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7471 }
9442dd57 7472 } else if (code == TS_REKEY) {
7473 if (!ssh->kex_in_progress && ssh->version == 2) {
7474 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7475 " user request", -1, NULL);
7476 }
125105d1 7477 } else if (code == TS_BRK) {
7478 if (ssh->state == SSH_STATE_CLOSED
7479 || ssh->state == SSH_STATE_PREPACKET) return;
7480 if (ssh->version == 1) {
7481 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7482 } else if (ssh->mainchan) {
ff3187f6 7483 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7484 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7485 ssh2_pkt_addstring(pktout, "break");
7486 ssh2_pkt_addbool(pktout, 0);
7487 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7488 ssh2_pkt_send(ssh, pktout);
125105d1 7489 }
6abbf9e3 7490 } else {
6f2d0cde 7491 /* Is is a POSIX signal? */
7492 char *signame = NULL;
7493 if (code == TS_SIGABRT) signame = "ABRT";
7494 if (code == TS_SIGALRM) signame = "ALRM";
7495 if (code == TS_SIGFPE) signame = "FPE";
7496 if (code == TS_SIGHUP) signame = "HUP";
7497 if (code == TS_SIGILL) signame = "ILL";
7498 if (code == TS_SIGINT) signame = "INT";
7499 if (code == TS_SIGKILL) signame = "KILL";
7500 if (code == TS_SIGPIPE) signame = "PIPE";
7501 if (code == TS_SIGQUIT) signame = "QUIT";
7502 if (code == TS_SIGSEGV) signame = "SEGV";
7503 if (code == TS_SIGTERM) signame = "TERM";
7504 if (code == TS_SIGUSR1) signame = "USR1";
7505 if (code == TS_SIGUSR2) signame = "USR2";
7506 /* The SSH-2 protocol does in principle support arbitrary named
7507 * signals, including signame@domain, but we don't support those. */
7508 if (signame) {
7509 /* It's a signal. */
7510 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7511 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7512 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7513 ssh2_pkt_addstring(pktout, "signal");
7514 ssh2_pkt_addbool(pktout, 0);
7515 ssh2_pkt_addstring(pktout, signame);
7516 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7517 logeventf(ssh, "Sent signal SIG%s", signame);
7518 }
7519 } else {
7520 /* Never heard of it. Do nothing */
7521 }
6abbf9e3 7522 }
374330e2 7523}
7524
51470298 7525void *new_sock_channel(void *handle, Socket s)
d74d141c 7526{
51470298 7527 Ssh ssh = (Ssh) handle;
d74d141c 7528 struct ssh_channel *c;
3d88e64d 7529 c = snew(struct ssh_channel);
51470298 7530 c->ssh = ssh;
d74d141c 7531
7532 if (c) {
bc240b21 7533 c->remoteid = -1; /* to be set when open confirmed */
51470298 7534 c->localid = alloc_channel_id(ssh);
d74d141c 7535 c->closes = 0;
bc240b21 7536 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7537 c->u.pfd.s = s;
013dd8c0 7538 bufchain_init(&c->v.v2.outbuffer);
51470298 7539 add234(ssh->channels, c);
d74d141c 7540 }
7541 return c;
7542}
7543
5471d09a 7544/*
7545 * This is called when stdout/stderr (the entity to which
7546 * from_backend sends data) manages to clear some backlog.
7547 */
ae9ae89f 7548static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7549{
51470298 7550 Ssh ssh = (Ssh) handle;
7551 if (ssh->version == 1) {
7552 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7553 ssh->v1_stdout_throttling = 0;
7554 ssh1_throttle(ssh, -1);
5471d09a 7555 }
7556 } else {
51470298 7557 if (ssh->mainchan && ssh->mainchan->closes == 0)
7558 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7559 }
7560}
7561
6b78788a 7562void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7563{
7564 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7565 Ssh ssh = c->ssh;
ff3187f6 7566 struct Packet *pktout;
d74d141c 7567
57356d63 7568 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7569
51470298 7570 if (ssh->version == 1) {
7571 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7572 PKT_INT, c->localid,
7573 PKT_STR, hostname,
7574 PKT_INT, port,
7575 //PKT_STR, <org:orgport>,
7576 PKT_END);
7577 } else {
ff3187f6 7578 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7579 ssh2_pkt_addstring(pktout, "direct-tcpip");
7580 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7581 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7582 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7583 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7584 ssh2_pkt_addstring(pktout, hostname);
7585 ssh2_pkt_adduint32(pktout, port);
bc240b21 7586 /*
7587 * We make up values for the originator data; partly it's
7588 * too much hassle to keep track, and partly I'm not
7589 * convinced the server should be told details like that
7590 * about my local network configuration.
7591 */
ff3187f6 7592 ssh2_pkt_addstring(pktout, "client-side-connection");
7593 ssh2_pkt_adduint32(pktout, 0);
7594 ssh2_pkt_send(ssh, pktout);
bc240b21 7595 }
d74d141c 7596}
7597
51470298 7598static Socket ssh_socket(void *handle)
32874aea 7599{
51470298 7600 Ssh ssh = (Ssh) handle;
7601 return ssh->s;
32874aea 7602}
8ccc75b0 7603
51470298 7604static int ssh_sendok(void *handle)
32874aea 7605{
51470298 7606 Ssh ssh = (Ssh) handle;
7607 return ssh->send_ok;
32874aea 7608}
fb09bf1c 7609
51470298 7610static int ssh_ldisc(void *handle, int option)
32874aea 7611{
51470298 7612 Ssh ssh = (Ssh) handle;
32874aea 7613 if (option == LD_ECHO)
51470298 7614 return ssh->echoing;
32874aea 7615 if (option == LD_EDIT)
51470298 7616 return ssh->editing;
0965bee0 7617 return FALSE;
7618}
7619
b9d7bcad 7620static void ssh_provide_ldisc(void *handle, void *ldisc)
7621{
7622 Ssh ssh = (Ssh) handle;
7623 ssh->ldisc = ldisc;
7624}
7625
a8327734 7626static void ssh_provide_logctx(void *handle, void *logctx)
7627{
7628 Ssh ssh = (Ssh) handle;
7629 ssh->logctx = logctx;
7630}
7631
51470298 7632static int ssh_return_exitcode(void *handle)
7633{
7634 Ssh ssh = (Ssh) handle;
3bb2f322 7635 if (ssh->s != NULL)
7636 return -1;
7637 else
7638 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7639}
7640
7641/*
7642 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7643 * that fails. This variable is the means by which scp.c can reach
7644 * into the SSH code and find out which one it got.
7645 */
7646extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7647{
51470298 7648 Ssh ssh = (Ssh) handle;
7649 return ssh->fallback_cmd;
d8d6c7e5 7650}
7651
374330e2 7652Backend ssh_backend = {
7653 ssh_init,
fabd1805 7654 ssh_free,
86916870 7655 ssh_reconfig,
374330e2 7656 ssh_send,
5471d09a 7657 ssh_sendbuffer,
374330e2 7658 ssh_size,
4017be6d 7659 ssh_special,
125105d1 7660 ssh_get_specials,
8ccc75b0 7661 ssh_socket,
d8d6c7e5 7662 ssh_return_exitcode,
97db3be4 7663 ssh_sendok,
0965bee0 7664 ssh_ldisc,
b9d7bcad 7665 ssh_provide_ldisc,
a8327734 7666 ssh_provide_logctx,
5471d09a 7667 ssh_unthrottle,
97db3be4 7668 22
bc240b21 7669};
Simon Tatham's PuTTY GUI SSH client; import of svn://svn.tartarus.org/sgt/putty