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Implement client-initiated rekeys after an hour, or after 1Gb of
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5
6#include "putty.h"
dacbd0e8 7#include "tree234.h"
fb09bf1c 8#include "ssh.h"
374330e2 9
10#ifndef FALSE
11#define FALSE 0
12#endif
13#ifndef TRUE
14#define TRUE 1
15#endif
16
32874aea 17#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20#define SSH1_CMSG_USER 4 /* 0x4 */
21#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29#define SSH1_SMSG_SUCCESS 14 /* 0xe */
30#define SSH1_SMSG_FAILURE 15 /* 0xf */
31#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34#define SSH1_CMSG_EOF 19 /* 0x13 */
35#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46#define SSH1_MSG_IGNORE 32 /* 0x20 */
47#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50#define SSH1_MSG_DEBUG 36 /* 0x24 */
51#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
58
59#define SSH1_AUTH_TIS 5 /* 0x5 */
60#define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 63/* Mask for protoflags we will echo back to server if seen */
32874aea 64#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
66#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67#define SSH2_MSG_IGNORE 2 /* 0x2 */
68#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69#define SSH2_MSG_DEBUG 4 /* 0x4 */
70#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72#define SSH2_MSG_KEXINIT 20 /* 0x14 */
73#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 86#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 88#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
102
00db133f 103/*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
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
51470298 2070static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2071{
51470298 2072 struct do_ssh_init_state {
2073 int vslen;
2074 char version[10];
2075 char *vstring;
2076 int vstrsize;
2077 int i;
2078 int proto1, proto2;
2079 };
2080 crState(do_ssh_init_state);
374330e2 2081
51470298 2082 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2083
2084 /* Search for the string "SSH-" in the input. */
51470298 2085 s->i = 0;
8df7a775 2086 while (1) {
2087 static const int transS[] = { 1, 2, 2, 1 };
2088 static const int transH[] = { 0, 0, 3, 0 };
2089 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2090 if (c == 'S')
51470298 2091 s->i = transS[s->i];
32874aea 2092 else if (c == 'H')
51470298 2093 s->i = transH[s->i];
32874aea 2094 else if (c == '-')
51470298 2095 s->i = transminus[s->i];
32874aea 2096 else
51470298 2097 s->i = 0;
2098 if (s->i < 0)
8df7a775 2099 break;
2100 crReturn(1); /* get another character */
374330e2 2101 }
8df7a775 2102
51470298 2103 s->vstrsize = 16;
3d88e64d 2104 s->vstring = snewn(s->vstrsize, char);
51470298 2105 strcpy(s->vstring, "SSH-");
2106 s->vslen = 4;
2107 s->i = 0;
374330e2 2108 while (1) {
8df7a775 2109 crReturn(1); /* get another char */
51470298 2110 if (s->vslen >= s->vstrsize - 1) {
2111 s->vstrsize += 16;
3d88e64d 2112 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2113 }
51470298 2114 s->vstring[s->vslen++] = c;
2115 if (s->i >= 0) {
374330e2 2116 if (c == '-') {
51470298 2117 s->version[s->i] = '\0';
2118 s->i = -1;
2119 } else if (s->i < sizeof(s->version) - 1)
2120 s->version[s->i++] = c;
c4ffc4d0 2121 } else if (c == '\012')
374330e2 2122 break;
2123 }
2124
51470298 2125 ssh->agentfwd_enabled = FALSE;
2126 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2127
51470298 2128 s->vstring[s->vslen] = 0;
2129 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
2130 {
2131 char *vlog;
3d88e64d 2132 vlog = snewn(20 + s->vslen, char);
51470298 2133 sprintf(vlog, "Server version: %s", s->vstring);
2134 logevent(vlog);
2135 sfree(vlog);
2136 }
2137 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2138
adf799dd 2139 /*
38d228a2 2140 * Decide which SSH protocol version to support.
adf799dd 2141 */
38d228a2 2142
2143 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2144 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2145 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2146 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2147
86916870 2148 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2149 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2150 crStop(0);
38d228a2 2151 }
86916870 2152 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2153 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2154 crStop(0);
38d228a2 2155 }
2156
86916870 2157 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
32874aea 2158 /*
38d228a2 2159 * Use v2 protocol.
32874aea 2160 */
2161 char verstring[80], vlog[100];
2162 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 2163 SHA_Init(&ssh->exhashbase);
32874aea 2164 /*
2165 * Hash our version string and their version string.
2166 */
51470298 2167 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
2168 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 2169 sprintf(vlog, "We claim version: %s", verstring);
2170 logevent(vlog);
c4ffc4d0 2171 strcat(verstring, "\012");
32874aea 2172 logevent("Using SSH protocol version 2");
51470298 2173 sk_write(ssh->s, verstring, strlen(verstring));
2174 ssh->protocol = ssh2_protocol;
b09eaa88 2175 ssh2_protocol_setup(ssh);
51470298 2176 ssh->version = 2;
2177 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 2178 } else {
32874aea 2179 /*
38d228a2 2180 * Use v1 protocol.
32874aea 2181 */
2182 char verstring[80], vlog[100];
2183 sprintf(verstring, "SSH-%s-%s",
51470298 2184 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 2185 sshver);
2186 sprintf(vlog, "We claim version: %s", verstring);
2187 logevent(vlog);
c4ffc4d0 2188 strcat(verstring, "\012");
759712a6 2189
32874aea 2190 logevent("Using SSH protocol version 1");
51470298 2191 sk_write(ssh->s, verstring, strlen(verstring));
2192 ssh->protocol = ssh1_protocol;
b09eaa88 2193 ssh1_protocol_setup(ssh);
51470298 2194 ssh->version = 1;
2195 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 2196 }
125105d1 2197 update_specials_menu(ssh->frontend);
51470298 2198 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2199 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2200
51470298 2201 sfree(s->vstring);
50526e47 2202
8df7a775 2203 crFinish(0);
2204}
2205
51470298 2206static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2207{
51470298 2208 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2209
2210 /*
2211 * To begin with, feed the characters one by one to the
2212 * protocol initialisation / selection function do_ssh_init().
2213 * When that returns 0, we're done with the initial greeting
2214 * exchange and can move on to packet discipline.
2215 */
2216 while (1) {
51470298 2217 int ret; /* need not be kept across crReturn */
8df7a775 2218 if (datalen == 0)
2219 crReturnV; /* more data please */
51470298 2220 ret = do_ssh_init(ssh, *data);
32874aea 2221 data++;
2222 datalen--;
8df7a775 2223 if (ret == 0)
2224 break;
2225 }
2226
2227 /*
2228 * We emerge from that loop when the initial negotiation is
2229 * over and we have selected an s_rdpkt function. Now pass
2230 * everything to s_rdpkt, and then pass the resulting packets
2231 * to the proper protocol handler.
2232 */
2233 if (datalen == 0)
2234 crReturnV;
2235 while (1) {
2236 while (datalen > 0) {
ff3187f6 2237 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2238 if (pktin) {
2239 ssh->protocol(ssh, NULL, 0, pktin);
2240 ssh_free_packet(pktin);
8df7a775 2241 }
ff3187f6 2242 if (ssh->state == SSH_STATE_CLOSED)
2243 return;
8df7a775 2244 }
2245 crReturnV;
2246 }
2247 crFinishV;
2248}
2249
36f94d1f 2250static void ssh_do_close(Ssh ssh)
32874aea 2251{
36f94d1f 2252 int i;
2253 struct ssh_channel *c;
2254
51470298 2255 ssh->state = SSH_STATE_CLOSED;
2256 if (ssh->s) {
2257 sk_close(ssh->s);
2258 ssh->s = NULL;
39934deb 2259 notify_remote_exit(ssh->frontend);
f3ab576e 2260 }
36f94d1f 2261 /*
2262 * Now we must shut down any port and X forwardings going
2263 * through this connection.
2264 */
74a98066 2265 if (ssh->channels) {
2266 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2267 switch (c->type) {
2268 case CHAN_X11:
2269 x11_close(c->u.x11.s);
2270 break;
2271 case CHAN_SOCKDATA:
2272 pfd_close(c->u.pfd.s);
2273 break;
2274 }
2275 del234(ssh->channels, c);
2276 if (ssh->version == 2)
2277 bufchain_clear(&c->v.v2.outbuffer);
2278 sfree(c);
36f94d1f 2279 }
36f94d1f 2280 }
2281}
2282
cbe2d68f 2283static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2284 int calling_back)
2285{
2286 Ssh ssh = (Ssh) plug;
2287 ssh_do_close(ssh);
7e78000d 2288 if (error_msg) {
32874aea 2289 /* A socket error has occurred. */
247308b5 2290 logevent(error_msg);
971bcc0a 2291 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2292 } else {
2293 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2294 }
7e78000d 2295 return 0;
2296}
2297
32874aea 2298static int ssh_receive(Plug plug, int urgent, char *data, int len)
2299{
51470298 2300 Ssh ssh = (Ssh) plug;
d8baa528 2301 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2302 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2303 ssh_do_close(ssh);
32874aea 2304 return 0;
3257deae 2305 }
fef97f43 2306 return 1;
374330e2 2307}
2308
5471d09a 2309static void ssh_sent(Plug plug, int bufsize)
2310{
51470298 2311 Ssh ssh = (Ssh) plug;
5471d09a 2312 /*
2313 * If the send backlog on the SSH socket itself clears, we
2314 * should unthrottle the whole world if it was throttled.
2315 */
2316 if (bufsize < SSH_MAX_BACKLOG)
51470298 2317 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2318}
2319
fb09bf1c 2320/*
8df7a775 2321 * Connect to specified host and port.
2322 * Returns an error message, or NULL on success.
6e1ebb76 2323 * Also places the canonical host name into `realhost'. It must be
2324 * freed by the caller.
8df7a775 2325 */
cbe2d68f 2326static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2327 char **realhost, int nodelay, int keepalive)
8df7a775 2328{
51470298 2329 static const struct plug_function_table fn_table = {
7e78000d 2330 ssh_closing,
5471d09a 2331 ssh_receive,
2332 ssh_sent,
2333 NULL
51470298 2334 };
7e78000d 2335
8df7a775 2336 SockAddr addr;
cbe2d68f 2337 const char *err;
8df7a775 2338
3d88e64d 2339 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2340 if (!ssh->savedhost)
8df7a775 2341 fatalbox("Out of memory");
51470298 2342 strcpy(ssh->savedhost, host);
8df7a775 2343
2344 if (port < 0)
2345 port = 22; /* default ssh port */
51470298 2346 ssh->savedport = port;
8df7a775 2347
2348 /*
2349 * Try to find host.
2350 */
57356d63 2351 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2352 addr = name_lookup(host, port, realhost, &ssh->cfg);
170c1e6e 2353 if ((err = sk_addr_error(addr)) != NULL) {
2354 sk_addr_free(addr);
8df7a775 2355 return err;
170c1e6e 2356 }
8df7a775 2357
8df7a775 2358 /*
2359 * Open socket.
2360 */
3ad9d396 2361 {
57356d63 2362 char addrbuf[100];
3ad9d396 2363 sk_getaddr(addr, addrbuf, 100);
57356d63 2364 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2365 }
51470298 2366 ssh->fn = &fn_table;
e8fa8f62 2367 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2368 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2369 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2370 ssh->s = NULL;
39934deb 2371 notify_remote_exit(ssh->frontend);
8df7a775 2372 return err;
67c4ba2e 2373 }
8df7a775 2374
8df7a775 2375 return NULL;
2376}
2377
2378/*
5471d09a 2379 * Throttle or unthrottle the SSH connection.
2380 */
51470298 2381static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2382{
51470298 2383 int old_count = ssh->v1_throttle_count;
2384 ssh->v1_throttle_count += adjust;
2385 assert(ssh->v1_throttle_count >= 0);
2386 if (ssh->v1_throttle_count && !old_count) {
2387 sk_set_frozen(ssh->s, 1);
2388 } else if (!ssh->v1_throttle_count && old_count) {
2389 sk_set_frozen(ssh->s, 0);
5471d09a 2390 }
2391}
2392
2393/*
2394 * Throttle or unthrottle _all_ local data streams (for when sends
2395 * on the SSH connection itself back up).
2396 */
51470298 2397static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2398{
2399 int i;
2400 struct ssh_channel *c;
2401
51470298 2402 if (enable == ssh->throttled_all)
5471d09a 2403 return;
51470298 2404 ssh->throttled_all = enable;
2405 ssh->overall_bufsize = bufsize;
2406 if (!ssh->channels)
5471d09a 2407 return;
51470298 2408 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2409 switch (c->type) {
2410 case CHAN_MAINSESSION:
2411 /*
2412 * This is treated separately, outside the switch.
2413 */
2414 break;
2415 case CHAN_X11:
2416 x11_override_throttle(c->u.x11.s, enable);
2417 break;
2418 case CHAN_AGENT:
2419 /* Agent channels require no buffer management. */
2420 break;
2421 case CHAN_SOCKDATA:
36f94d1f 2422 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2423 break;
2424 }
2425 }
2426}
2427
2428/*
51470298 2429 * Username and password input, abstracted off into routines
2430 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2431 */
0405e71f 2432
2433/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2434static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2435{
51470298 2436 ssh->userpass_input_buffer = buffer;
2437 ssh->userpass_input_buflen = buflen;
2438 ssh->userpass_input_bufpos = 0;
2439 ssh->userpass_input_echo = echo;
0405e71f 2440}
2441
2442/*
2443 * Process some terminal data in the course of username/password
2444 * input. Returns >0 for success (line of input returned in
2445 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2446 * for inconclusive (keep waiting for more input please).
2447 */
ae9ae89f 2448static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2449{
2450 char c;
2451
2452 while (inlen--) {
2453 switch (c = *in++) {
2454 case 10:
2455 case 13:
51470298 2456 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2457 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2458 return +1;
2459 break;
2460 case 8:
2461 case 127:
51470298 2462 if (ssh->userpass_input_bufpos > 0) {
2463 if (ssh->userpass_input_echo)
2464 c_write_str(ssh, "\b \b");
2465 ssh->userpass_input_bufpos--;
0405e71f 2466 }
2467 break;
2468 case 21:
2469 case 27:
51470298 2470 while (ssh->userpass_input_bufpos > 0) {
2471 if (ssh->userpass_input_echo)
2472 c_write_str(ssh, "\b \b");
2473 ssh->userpass_input_bufpos--;
0405e71f 2474 }
2475 break;
2476 case 3:
2477 case 4:
2478 return -1;
2479 break;
2480 default:
4692a14a 2481 /*
2482 * This simplistic check for printability is disabled
2483 * when we're doing password input, because some people
2484 * have control characters in their passwords.o
2485 */
2486 if ((!ssh->userpass_input_echo ||
2487 (c >= ' ' && c <= '~') ||
0405e71f 2488 ((unsigned char) c >= 160))
51470298 2489 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2490 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2491 if (ssh->userpass_input_echo)
2492 c_write(ssh, &c, 1);
0405e71f 2493 }
2494 break;
2495 }
2496 }
2497 return 0;
2498}
2499
f11d78f2 2500static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2501{
2502 Ssh ssh = (Ssh) sshv;
2503
2504 ssh->agent_response = reply;
2505 ssh->agent_response_len = replylen;
2506
2507 if (ssh->version == 1)
ff3187f6 2508 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2509 else
ff3187f6 2510 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2511}
2512
f11d78f2 2513static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2514{
2515 struct ssh_channel *c = (struct ssh_channel *)cv;
2516 Ssh ssh = c->ssh;
2517 void *sentreply = reply;
2518
2519 if (!sentreply) {
2520 /* Fake SSH_AGENT_FAILURE. */
2521 sentreply = "\0\0\0\1\5";
2522 replylen = 5;
2523 }
2524 if (ssh->version == 2) {
2525 ssh2_add_channel_data(c, sentreply, replylen);
2526 ssh2_try_send(c);
2527 } else {
2528 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2529 PKT_INT, c->remoteid,
9a10ecf4 2530 PKTT_DATA,
839f10db 2531 PKT_INT, replylen,
2532 PKT_DATA, sentreply, replylen,
9a10ecf4 2533 PKTT_OTHER,
839f10db 2534 PKT_END);
2535 }
2536 if (reply)
2537 sfree(reply);
2538}
2539
0405e71f 2540/*
fb09bf1c 2541 * Handle the key exchange and user authentication phases.
2542 */
ff3187f6 2543static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2544 struct Packet *pktin)
fb09bf1c 2545{
0016d70b 2546 int i, j, ret;
2547 unsigned char cookie[8], *ptr;
374330e2 2548 struct RSAKey servkey, hostkey;
2549 struct MD5Context md5c;
51470298 2550 struct do_ssh1_login_state {
2551 int len;
2552 unsigned char *rsabuf, *keystr1, *keystr2;
2553 unsigned long supported_ciphers_mask, supported_auths_mask;
2554 int tried_publickey, tried_agent;
2555 int tis_auth_refused, ccard_auth_refused;
2556 unsigned char session_id[16];
2557 int cipher_type;
2558 char username[100];
2559 void *publickey_blob;
2560 int publickey_bloblen;
2561 char password[100];
2562 char prompt[200];
2563 int pos;
2564 char c;
2565 int pwpkt_type;
2566 unsigned char request[5], *response, *p;
2567 int responselen;
2568 int keyi, nkeys;
2569 int authed;
2570 struct RSAKey key;
2571 Bignum challenge;
2572 char *commentp;
2573 int commentlen;
2574 };
2575 crState(do_ssh1_login_state);
2576
2577 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2578
b09eaa88 2579 random_init();
2580
ff3187f6 2581 if (!pktin)
2582 crWaitUntil(pktin);
374330e2 2583
ff3187f6 2584 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2585 bombout(("Public key packet not received"));
7ffdbc1a 2586 crStop(0);
8d5de777 2587 }
374330e2 2588
c5e9c988 2589 logevent("Received public keys");
374330e2 2590
ff3187f6 2591 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2592 if (!ptr) {
2593 bombout(("SSH1 public key packet stopped before random cookie"));
2594 crStop(0);
2595 }
2596 memcpy(cookie, ptr, 8);
374330e2 2597
ff3187f6 2598 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2599 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2600 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2601 crStop(0);
2602 }
374330e2 2603
c5e9c988 2604 /*
1c2a93c4 2605 * Log the host key fingerprint.
c5e9c988 2606 */
c5e9c988 2607 {
2608 char logmsg[80];
1c2a93c4 2609 logevent("Host key fingerprint is:");
c5e9c988 2610 strcpy(logmsg, " ");
32874aea 2611 hostkey.comment = NULL;
2612 rsa_fingerprint(logmsg + strlen(logmsg),
2613 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2614 logevent(logmsg);
2615 }
2616
ff3187f6 2617 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2618 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2619 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2620
51470298 2621 ssh->v1_local_protoflags =
2622 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2623 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2624
c5e9c988 2625 MD5Init(&md5c);
51470298 2626 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2627 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2628 MD5Update(&md5c, cookie, 8);
51470298 2629 MD5Final(s->session_id, &md5c);
374330e2 2630
32874aea 2631 for (i = 0; i < 32; i++)
51470298 2632 ssh->session_key[i] = random_byte();
374330e2 2633
0016d70b 2634 /*
2635 * Verify that the `bits' and `bytes' parameters match.
2636 */
2637 if (hostkey.bits > hostkey.bytes * 8 ||
2638 servkey.bits > servkey.bytes * 8) {
2639 bombout(("SSH1 public keys were badly formatted"));
2640 crStop(0);
2641 }
2642
51470298 2643 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2644
3d88e64d 2645 s->rsabuf = snewn(s->len, unsigned char);
51470298 2646 if (!s->rsabuf)
374330e2 2647 fatalbox("Out of memory");
2648
89ee5268 2649 /*
2650 * Verify the host key.
2651 */
2652 {
32874aea 2653 /*
2654 * First format the key into a string.
2655 */
2656 int len = rsastr_len(&hostkey);
2657 char fingerprint[100];
3d88e64d 2658 char *keystr = snewn(len, char);
32874aea 2659 if (!keystr)
2660 fatalbox("Out of memory");
2661 rsastr_fmt(keystr, &hostkey);
2662 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2663 verify_ssh_host_key(ssh->frontend,
2664 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2665 fingerprint);
2666 sfree(keystr);
2667 }
2668
2669 for (i = 0; i < 32; i++) {
51470298 2670 s->rsabuf[i] = ssh->session_key[i];
374330e2 2671 if (i < 16)
51470298 2672 s->rsabuf[i] ^= s->session_id[i];
374330e2 2673 }
2674
2675 if (hostkey.bytes > servkey.bytes) {
0016d70b 2676 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2677 if (ret)
2678 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2679 } else {
0016d70b 2680 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2681 if (ret)
2682 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2683 }
2684 if (!ret) {
2685 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2686 crStop(0);
374330e2 2687 }
2688
c5e9c988 2689 logevent("Encrypted session key");
2690
ca20bfcf 2691 {
2692 int cipher_chosen = 0, warn = 0;
2693 char *cipher_string = NULL;
51470298 2694 int i;
ca20bfcf 2695 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2696 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2697 if (next_cipher == CIPHER_WARN) {
2698 /* If/when we choose a cipher, warn about it */
2699 warn = 1;
2700 } else if (next_cipher == CIPHER_AES) {
2701 /* XXX Probably don't need to mention this. */
2702 logevent("AES not supported in SSH1, skipping");
2703 } else {
2704 switch (next_cipher) {
51470298 2705 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2706 cipher_string = "3DES"; break;
51470298 2707 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2708 cipher_string = "Blowfish"; break;
51470298 2709 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2710 cipher_string = "single-DES"; break;
2711 }
51470298 2712 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2713 cipher_chosen = 1;
2714 }
2715 }
2716 if (!cipher_chosen) {
51470298 2717 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2718 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2719 "supporting 3DES encryption"));
2720 else
2721 /* shouldn't happen */
6b5cf8b4 2722 bombout(("No supported ciphers found"));
7ffdbc1a 2723 crStop(0);
a99a05c0 2724 }
ca20bfcf 2725
2726 /* Warn about chosen cipher if necessary. */
2727 if (warn)
a8327734 2728 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2729 }
ca20bfcf 2730
51470298 2731 switch (s->cipher_type) {
32874aea 2732 case SSH_CIPHER_3DES:
2733 logevent("Using 3DES encryption");
2734 break;
2735 case SSH_CIPHER_DES:
2736 logevent("Using single-DES encryption");
2737 break;
2738 case SSH_CIPHER_BLOWFISH:
2739 logevent("Using Blowfish encryption");
2740 break;
c5e9c988 2741 }
bea1ef5f 2742
51470298 2743 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2744 PKT_CHAR, s->cipher_type,
32874aea 2745 PKT_DATA, cookie, 8,
51470298 2746 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2747 PKT_DATA, s->rsabuf, s->len,
2748 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2749
c5e9c988 2750 logevent("Trying to enable encryption...");
374330e2 2751
51470298 2752 sfree(s->rsabuf);
374330e2 2753
51470298 2754 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2755 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2756 &ssh_3des);
371e569c 2757 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2758 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2759 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2760
0183b242 2761 ssh->crcda_ctx = crcda_make_context();
2762 logevent("Installing CRC compensation attack detector");
2763
679539d7 2764 if (servkey.modulus) {
2765 sfree(servkey.modulus);
2766 servkey.modulus = NULL;
2767 }
2768 if (servkey.exponent) {
2769 sfree(servkey.exponent);
2770 servkey.exponent = NULL;
2771 }
2772 if (hostkey.modulus) {
2773 sfree(hostkey.modulus);
2774 hostkey.modulus = NULL;
2775 }
2776 if (hostkey.exponent) {
2777 sfree(hostkey.exponent);
2778 hostkey.exponent = NULL;
2779 }
ff3187f6 2780 crWaitUntil(pktin);
374330e2 2781
ff3187f6 2782 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2783 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2784 crStop(0);
8d5de777 2785 }
374330e2 2786
c5e9c988 2787 logevent("Successfully started encryption");
2788
374330e2 2789 fflush(stdout);
2790 {
aa09f7d0 2791 if (!*ssh->cfg.username) {
c0a81592 2792 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2793 if (!ssh_get_line("login as: ",
51470298 2794 s->username, sizeof(s->username), FALSE)) {
32874aea 2795 /*
2796 * get_line failed to get a username.
2797 * Terminate.
2798 */
2799 logevent("No username provided. Abandoning session.");
3bb2f322 2800 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2801 crStop(1);
32874aea 2802 }
2803 } else {
51470298 2804 int ret; /* need not be kept over crReturn */
2805 c_write_str(ssh, "login as: ");
2806 ssh->send_ok = 1;
0405e71f 2807
51470298 2808 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2809 do {
ff3187f6 2810 crWaitUntil(!pktin);
51470298 2811 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2812 } while (ret == 0);
2813 if (ret < 0)
2814 cleanup_exit(0);
51470298 2815 c_write_str(ssh, "\r\n");
32874aea 2816 }
2817 } else {
86916870 2818 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2819 s->username[sizeof(s->username)-1] = '\0';
374330e2 2820 }
fb09bf1c 2821
51470298 2822 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2823 {
51470298 2824 char userlog[22 + sizeof(s->username)];
2825 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2826 logevent(userlog);
32874aea 2827 if (flags & FLAG_INTERACTIVE &&
2828 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2829 strcat(userlog, "\r\n");
51470298 2830 c_write_str(ssh, userlog);
3c8e959b 2831 }
c5e9c988 2832 }
374330e2 2833 }
2834
ff3187f6 2835 crWaitUntil(pktin);
374330e2 2836
51470298 2837 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2838 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2839 s->tried_publickey = s->tried_agent = 1;
0df73905 2840 } else {
51470298 2841 s->tried_publickey = s->tried_agent = 0;
0df73905 2842 }
51470298 2843 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2844 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2845 if (!filename_is_null(ssh->cfg.keyfile)) {
2846 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2847 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2848 s->publickey_blob = NULL;
396778f1 2849 } else
51470298 2850 s->publickey_blob = NULL;
7cca0d81 2851
ff3187f6 2852 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 2853 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2854
51470298 2855 if (agent_exists() && !s->tried_agent) {
32874aea 2856 /*
2857 * Attempt RSA authentication using Pageant.
2858 */
32874aea 2859 void *r;
2860
51470298 2861 s->authed = FALSE;
2862 s->tried_agent = 1;
32874aea 2863 logevent("Pageant is running. Requesting keys.");
2864
2865 /* Request the keys held by the agent. */
51470298 2866 PUT_32BIT(s->request, 1);
2867 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2868 if (!agent_query(s->request, 5, &r, &s->responselen,
2869 ssh_agent_callback, ssh)) {
2870 do {
2871 crReturn(0);
ff3187f6 2872 if (pktin) {
839f10db 2873 bombout(("Unexpected data from server while waiting"
2874 " for agent response"));
2875 crStop(0);
2876 }
ff3187f6 2877 } while (pktin || inlen > 0);
839f10db 2878 r = ssh->agent_response;
2879 s->responselen = ssh->agent_response_len;
2880 }
51470298 2881 s->response = (unsigned char *) r;
2882 if (s->response && s->responselen >= 5 &&
2883 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2884 s->p = s->response + 5;
2885 s->nkeys = GET_32BIT(s->p);
2886 s->p += 4;
32874aea 2887 {
2888 char buf[64];
51470298 2889 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2890 logevent(buf);
2891 }
51470298 2892 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2893 {
2894 char buf[64];
51470298 2895 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2896 logevent(buf);
2897 }
51470298 2898 if (s->publickey_blob &&
2899 !memcmp(s->p, s->publickey_blob,
2900 s->publickey_bloblen)) {
396778f1 2901 logevent("This key matches configured key file");
51470298 2902 s->tried_publickey = 1;
396778f1 2903 }
51470298 2904 s->p += 4;
0016d70b 2905 {
2906 int n, ok = FALSE;
2907 do { /* do while (0) to make breaking easy */
2908 n = ssh1_read_bignum
2909 (s->p, s->responselen-(s->p-s->response),
2910 &s->key.exponent);
2911 if (n < 0)
2912 break;
2913 s->p += n;
2914 n = ssh1_read_bignum
2915 (s->p, s->responselen-(s->p-s->response),
2916 &s->key.modulus);
2917 if (n < 0)
2918 break;
2919 s->p += n;
2920 if (s->responselen - (s->p-s->response) < 4)
2921 break;
2922 s->commentlen = GET_32BIT(s->p);
2923 s->p += 4;
2924 if (s->responselen - (s->p-s->response) <
2925 s->commentlen)
2926 break;
2927 s->commentp = (char *)s->p;
2928 s->p += s->commentlen;
2929 ok = TRUE;
2930 } while (0);
2931 if (!ok) {
2932 logevent("Pageant key list packet was truncated");
2933 break;
2934 }
2935 }
51470298 2936 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2937 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 2938 crWaitUntil(pktin);
2939 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2940 logevent("Key refused");
2941 continue;
2942 }
2943 logevent("Received RSA challenge");
ff3187f6 2944 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 2945 bombout(("Server's RSA challenge was badly formatted"));
2946 crStop(0);
2947 }
2948
32874aea 2949 {
2950 char *agentreq, *q, *ret;
2d466ffd 2951 void *vret;
32874aea 2952 int len, retlen;
2953 len = 1 + 4; /* message type, bit count */
51470298 2954 len += ssh1_bignum_length(s->key.exponent);
2955 len += ssh1_bignum_length(s->key.modulus);
2956 len += ssh1_bignum_length(s->challenge);
32874aea 2957 len += 16; /* session id */
2958 len += 4; /* response format */
3d88e64d 2959 agentreq = snewn(4 + len, char);
32874aea 2960 PUT_32BIT(agentreq, len);
2961 q = agentreq + 4;
2962 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2963 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2964 q += 4;
51470298 2965 q += ssh1_write_bignum(q, s->key.exponent);
2966 q += ssh1_write_bignum(q, s->key.modulus);
2967 q += ssh1_write_bignum(q, s->challenge);
2968 memcpy(q, s->session_id, 16);
32874aea 2969 q += 16;
2970 PUT_32BIT(q, 1); /* response format */
839f10db 2971 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2972 ssh_agent_callback, ssh)) {
2973 sfree(agentreq);
2974 do {
2975 crReturn(0);
ff3187f6 2976 if (pktin) {
839f10db 2977 bombout(("Unexpected data from server"
2978 " while waiting for agent"
2979 " response"));
2980 crStop(0);
2981 }
ff3187f6 2982 } while (pktin || inlen > 0);
839f10db 2983 vret = ssh->agent_response;
2984 retlen = ssh->agent_response_len;
2985 } else
2986 sfree(agentreq);
2d466ffd 2987 ret = vret;
32874aea 2988 if (ret) {
2989 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2990 logevent("Sending Pageant's response");
51470298 2991 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2992 PKT_DATA, ret + 5, 16,
2993 PKT_END);
2994 sfree(ret);
ff3187f6 2995 crWaitUntil(pktin);
2996 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 2997 logevent
2998 ("Pageant's response accepted");
2999 if (flags & FLAG_VERBOSE) {
51470298 3000 c_write_str(ssh, "Authenticated using"
3001 " RSA key \"");
3002 c_write(ssh, s->commentp,
3003 s->commentlen);
3004 c_write_str(ssh, "\" from agent\r\n");
32874aea 3005 }
51470298 3006 s->authed = TRUE;
32874aea 3007 } else
3008 logevent
3009 ("Pageant's response not accepted");
3010 } else {
3011 logevent
3012 ("Pageant failed to answer challenge");
3013 sfree(ret);
3014 }
3015 } else {
3016 logevent("No reply received from Pageant");
3017 }
3018 }
51470298 3019 freebn(s->key.exponent);
3020 freebn(s->key.modulus);
3021 freebn(s->challenge);
3022 if (s->authed)
32874aea 3023 break;
3024 }
29b1d0b3 3025 sfree(s->response);
32874aea 3026 }
51470298 3027 if (s->authed)
32874aea 3028 break;
3029 }
9a30e26b 3030 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3031 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3032
86916870 3033 if (ssh->cfg.try_tis_auth &&
51470298 3034 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3035 !s->tis_auth_refused) {
3036 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3037 logevent("Requested TIS authentication");
51470298 3038 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3039 crWaitUntil(pktin);
3040 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3041 logevent("TIS authentication declined");
3042 if (flags & FLAG_INTERACTIVE)
51470298 3043 c_write_str(ssh, "TIS authentication refused.\r\n");
3044 s->tis_auth_refused = 1;
614a20a0 3045 continue;
32874aea 3046 } else {
0016d70b 3047 char *challenge;
3048 int challengelen;
3049
ff3187f6 3050 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3051 if (!challenge) {
3052 bombout(("TIS challenge packet was badly formed"));
3053 crStop(0);
3054 }
32874aea 3055 logevent("Received TIS challenge");
51470298 3056 if (challengelen > sizeof(s->prompt) - 1)
3057 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3058 memcpy(s->prompt, challenge, challengelen);
614a20a0 3059 /* Prompt heuristic comes from OpenSSH */
51470298 3060 strncpy(s->prompt + challengelen,
3061 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3062 "": "\r\nResponse: ",
51470298 3063 (sizeof s->prompt) - challengelen);
3064 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3065 }
3066 }
86916870 3067 if (ssh->cfg.try_tis_auth &&
51470298 3068 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3069 !s->ccard_auth_refused) {
3070 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3071 logevent("Requested CryptoCard authentication");
51470298 3072 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3073 crWaitUntil(pktin);
3074 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3075 logevent("CryptoCard authentication declined");
51470298 3076 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3077 s->ccard_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(("CryptoCard challenge packet was badly formed"));
3086 crStop(0);
3087 }
32874aea 3088 logevent("Received CryptoCard challenge");
51470298 3089 if (challengelen > sizeof(s->prompt) - 1)
3090 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3091 memcpy(s->prompt, challenge, challengelen);
51470298 3092 strncpy(s->prompt + challengelen,
3093 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3094 "" : "\r\nResponse: ",
51470298 3095 sizeof(s->prompt) - challengelen);
3096 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3097 }
3098 }
51470298 3099 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3100 sprintf(s->prompt, "%.90s@%.90s's password: ",
3101 s->username, ssh->savedhost);
32874aea 3102 }
51470298 3103 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3104 char *comment = NULL;
231ee168 3105 int type;
3106 char msgbuf[256];
32874aea 3107 if (flags & FLAG_VERBOSE)
51470298 3108 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3109 logeventf(ssh, "Trying public key \"%s\"",
3110 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3111 type = key_type(&ssh->cfg.keyfile);
231ee168 3112 if (type != SSH_KEYTYPE_SSH1) {
3113 sprintf(msgbuf, "Key is of wrong type (%s)",
3114 key_type_to_str(type));
3115 logevent(msgbuf);
51470298 3116 c_write_str(ssh, msgbuf);
3117 c_write_str(ssh, "\r\n");
3118 s->tried_publickey = 1;
231ee168 3119 continue;
3120 }
9a30e26b 3121 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3122 if (flags & FLAG_VERBOSE)
51470298 3123 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3124 goto tryauth;
3125 }
51470298 3126 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3127 sfree(comment);
3128 }
a52f067e 3129
614a20a0 3130 /*
3131 * Show password prompt, having first obtained it via a TIS
3132 * or CryptoCard exchange if we're doing TIS or CryptoCard
3133 * authentication.
3134 */
fa17a66e 3135 if (ssh_get_line) {
51470298 3136 if (!ssh_get_line(s->prompt, s->password,
3137 sizeof(s->password), TRUE)) {
32874aea 3138 /*
3139 * get_line failed to get a password (for example
3140 * because one was supplied on the command line
3141 * which has already failed to work). Terminate.
3142 */
51470298 3143 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3144 PKT_STR, "No more passwords available to try",
3145 PKT_END);
247308b5 3146 logevent("Unable to authenticate");
a8327734 3147 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3148 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3149 crStop(1);
32874aea 3150 }
fb09bf1c 3151 } else {
614a20a0 3152 /* Prompt may have come from server. We've munged it a bit, so
3153 * we know it to be zero-terminated at least once. */
51470298 3154 int ret; /* need not be saved over crReturn */
3155 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3156 s->pos = 0;
0405e71f 3157
51470298 3158 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3159 do {
ff3187f6 3160 crWaitUntil(!pktin);
51470298 3161 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3162 } while (ret == 0);
3163 if (ret < 0)
3164 cleanup_exit(0);
51470298 3165 c_write_str(ssh, "\r\n");
32874aea 3166 }
3167
3168 tryauth:
51470298 3169 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3170 /*
3171 * Try public key authentication with the specified
3172 * key file.
3173 */
51470298 3174 s->tried_publickey = 1;
3175
3176 {
222d54dc 3177 const char *error = NULL;
3178 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3179 &error);
51470298 3180 if (ret == 0) {
3181 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3182 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3183 c_write_str(ssh, " (");
3184 c_write_str(ssh, error);
3185 c_write_str(ssh, ").\r\n");
51470298 3186 continue; /* go and try password */
3187 }
3188 if (ret == -1) {
3189 c_write_str(ssh, "Wrong passphrase.\r\n");
3190 s->tried_publickey = 0;
3191 continue; /* try again */
3192 }
32874aea 3193 }
3194
3195 /*
3196 * Send a public key attempt.
3197 */
51470298 3198 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3199 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3200
ff3187f6 3201 crWaitUntil(pktin);
3202 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3203 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3204 continue; /* go and try password */
3205 }
ff3187f6 3206 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3207 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3208 crStop(0);
32874aea 3209 }
32874aea 3210
51470298 3211 {
3212 int i;
3213 unsigned char buffer[32];
3214 Bignum challenge, response;
3215
ff3187f6 3216 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3217 bombout(("Server's RSA challenge was badly formatted"));
3218 crStop(0);
3219 }
51470298 3220 response = rsadecrypt(challenge, &s->key);
3221 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3222
51470298 3223 for (i = 0; i < 32; i++) {
3224 buffer[i] = bignum_byte(response, 31 - i);
3225 }
3226
3227 MD5Init(&md5c);
3228 MD5Update(&md5c, buffer, 32);
3229 MD5Update(&md5c, s->session_id, 16);
3230 MD5Final(buffer, &md5c);
32874aea 3231
51470298 3232 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3233 PKT_DATA, buffer, 16, PKT_END);
3234
3235 freebn(challenge);
3236 freebn(response);
3237 }
32874aea 3238
ff3187f6 3239 crWaitUntil(pktin);
3240 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3241 if (flags & FLAG_VERBOSE)
51470298 3242 c_write_str(ssh, "Failed to authenticate with"
3243 " our public key.\r\n");
32874aea 3244 continue; /* go and try password */
ff3187f6 3245 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3246 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3247 crStop(0);
32874aea 3248 }
3249
3250 break; /* we're through! */
3251 } else {
51470298 3252 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3253 /*
3254 * Defence against traffic analysis: we send a
3255 * whole bunch of packets containing strings of
3256 * different lengths. One of these strings is the
3257 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3258 * The others are all random data in
3259 * SSH1_MSG_IGNORE packets. This way a passive
3260 * listener can't tell which is the password, and
3261 * hence can't deduce the password length.
3262 *
3263 * Anybody with a password length greater than 16
3264 * bytes is going to have enough entropy in their
3265 * password that a listener won't find it _that_
3266 * much help to know how long it is. So what we'll
3267 * do is:
3268 *
3269 * - if password length < 16, we send 15 packets
3270 * containing string lengths 1 through 15
3271 *
3272 * - otherwise, we let N be the nearest multiple
3273 * of 8 below the password length, and send 8
3274 * packets containing string lengths N through
3275 * N+7. This won't obscure the order of
3276 * magnitude of the password length, but it will
3277 * introduce a bit of extra uncertainty.
3278 *
3279 * A few servers (the old 1.2.18 through 1.2.22)
3280 * can't deal with SSH1_MSG_IGNORE. For these
3281 * servers, we need an alternative defence. We make
3282 * use of the fact that the password is interpreted
3283 * as a C string: so we can append a NUL, then some
3284 * random data.
bd358db1 3285 *
3286 * One server (a Cisco one) can deal with neither
3287 * SSH1_MSG_IGNORE _nor_ a padded password string.
3288 * For this server we are left with no defences
3289 * against password length sniffing.
32874aea 3290 */
51470298 3291 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3292 /*
3293 * The server can deal with SSH1_MSG_IGNORE, so
3294 * we can use the primary defence.
3295 */
32874aea 3296 int bottom, top, pwlen, i;
3297 char *randomstr;
3298
51470298 3299 pwlen = strlen(s->password);
32874aea 3300 if (pwlen < 16) {
3301 bottom = 0; /* zero length passwords are OK! :-) */
3302 top = 15;
3303 } else {
3304 bottom = pwlen & ~7;
3305 top = bottom + 7;
3306 }
3307
3308 assert(pwlen >= bottom && pwlen <= top);
3309
3d88e64d 3310 randomstr = snewn(top + 1, char);
32874aea 3311
3312 for (i = bottom; i <= top; i++) {
9a10ecf4 3313 if (i == pwlen) {
51470298 3314 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3315 PKTT_PASSWORD, PKT_STR, s->password,
3316 PKTT_OTHER, PKT_END);
3317 } else {
32874aea 3318 for (j = 0; j < i; j++) {
3319 do {
3320 randomstr[j] = random_byte();
3321 } while (randomstr[j] == '\0');
3322 }
3323 randomstr[i] = '\0';
51470298 3324 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3325 PKT_STR, randomstr, PKT_END);
3326 }
3327 }
bd358db1 3328 logevent("Sending password with camouflage packets");
51470298 3329 ssh_pkt_defersend(ssh);
679539d7 3330 sfree(randomstr);
bd358db1 3331 }
51470298 3332 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3333 /*
3334 * The server can't deal with SSH1_MSG_IGNORE
3335 * but can deal with padded passwords, so we
3336 * can use the secondary defence.
3337 */
bd358db1 3338 char string[64];
51470298 3339 char *ss;
bd358db1 3340 int len;
3341
51470298 3342 len = strlen(s->password);
bd358db1 3343 if (len < sizeof(string)) {
51470298 3344 ss = string;
3345 strcpy(string, s->password);
bd358db1 3346 len++; /* cover the zero byte */
3347 while (len < sizeof(string)) {
3348 string[len++] = (char) random_byte();
3349 }
3350 } else {
51470298 3351 ss = s->password;
bd358db1 3352 }
3353 logevent("Sending length-padded password");
9a10ecf4 3354 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3355 PKT_INT, len, PKT_DATA, ss, len,
3356 PKTT_OTHER, PKT_END);
bd358db1 3357 } else {
3358 /*
3359 * The server has _both_
3360 * BUG_CHOKES_ON_SSH1_IGNORE and
3361 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3362 * therefore nothing we can do.
3363 */
3364 int len;
51470298 3365 len = strlen(s->password);
bd358db1 3366 logevent("Sending unpadded password");
9a10ecf4 3367 send_packet(ssh, s->pwpkt_type,
3368 PKTT_PASSWORD, PKT_INT, len,
3369 PKT_DATA, s->password, len,
3370 PKTT_OTHER, PKT_END);
32874aea 3371 }
3372 } else {
9a10ecf4 3373 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3374 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3375 }
3376 }
c5e9c988 3377 logevent("Sent password");
51470298 3378 memset(s->password, 0, strlen(s->password));
ff3187f6 3379 crWaitUntil(pktin);
3380 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3381 if (flags & FLAG_VERBOSE)
51470298 3382 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3383 logevent("Authentication refused");
ff3187f6 3384 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3385 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3386 crStop(0);
374330e2 3387 }
3388 }
3389
c5e9c988 3390 logevent("Authentication successful");
3391
fb09bf1c 3392 crFinish(1);
3393}
3394
32874aea 3395void sshfwd_close(struct ssh_channel *c)
3396{
51470298 3397 Ssh ssh = c->ssh;
3398
36f94d1f 3399 if (ssh->state != SSH_STATE_SESSION) {
3400 assert(ssh->state == SSH_STATE_CLOSED);
3401 return;
3402 }
3403
80e48603 3404 if (c && !c->closes) {
4ed34d25 3405 /*
3406 * If the channel's remoteid is -1, we have sent
3407 * CHANNEL_OPEN for this channel, but it hasn't even been
3408 * acknowledged by the server. So we must set a close flag
3409 * on it now, and then when the server acks the channel
3410 * open, we can close it then.
3411 */
36cac739 3412 if (((int)c->remoteid) != -1) {
51470298 3413 if (ssh->version == 1) {
3414 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3415 PKT_END);
3416 } else {
ff3187f6 3417 struct Packet *pktout;
3418 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3419 ssh2_pkt_adduint32(pktout, c->remoteid);
3420 ssh2_pkt_send(ssh, pktout);
4ed34d25 3421 }
32874aea 3422 }
0357890f 3423 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3424 if (c->type == CHAN_X11) {
3425 c->u.x11.s = NULL;
d74d141c 3426 logevent("Forwarded X11 connection terminated");
4ed34d25 3427 } else if (c->type == CHAN_SOCKDATA ||
3428 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3429 c->u.pfd.s = NULL;
3430 logevent("Forwarded port closed");
32874aea 3431 }
3432 }
3433}
3434
5471d09a 3435int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3436{
51470298 3437 Ssh ssh = c->ssh;
3438
36f94d1f 3439 if (ssh->state != SSH_STATE_SESSION) {
3440 assert(ssh->state == SSH_STATE_CLOSED);
3441 return 0;
3442 }
3443
51470298 3444 if (ssh->version == 1) {
3445 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3446 PKT_INT, c->remoteid,
9a10ecf4 3447 PKTT_DATA,
3448 PKT_INT, len, PKT_DATA, buf, len,
3449 PKTT_OTHER, PKT_END);
5471d09a 3450 /*
3451 * In SSH1 we can return 0 here - implying that forwarded
3452 * connections are never individually throttled - because
3453 * the only circumstance that can cause throttling will be
3454 * the whole SSH connection backing up, in which case
3455 * _everything_ will be throttled as a whole.
3456 */
3457 return 0;
783415f8 3458 } else {
32874aea 3459 ssh2_add_channel_data(c, buf, len);
5471d09a 3460 return ssh2_try_send(c);
3461 }
3462}
3463
3464void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3465{
51470298 3466 Ssh ssh = c->ssh;
3467
36f94d1f 3468 if (ssh->state != SSH_STATE_SESSION) {
3469 assert(ssh->state == SSH_STATE_CLOSED);
3470 return;
3471 }
3472
51470298 3473 if (ssh->version == 1) {
5471d09a 3474 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3475 c->v.v1.throttling = 0;
51470298 3476 ssh1_throttle(ssh, -1);
5471d09a 3477 }
3478 } else {
3479 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3480 }
9c964e85 3481}
3482
b09eaa88 3483static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
3484 struct Packet *pktin)
32874aea 3485{
b09eaa88 3486 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 3487
86916870 3488 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 3489 logevent("Requesting agent forwarding");
51470298 3490 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3491 do {
3492 crReturnV;
ff3187f6 3493 } while (!pktin);
3494 if (pktin->type != SSH1_SMSG_SUCCESS
3495 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3496 bombout(("Protocol confusion"));
7ffdbc1a 3497 crStopV;
ff3187f6 3498 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3499 logevent("Agent forwarding refused");
3500 } else {
3501 logevent("Agent forwarding enabled");
51470298 3502 ssh->agentfwd_enabled = TRUE;
db7d555c 3503 }
dacbd0e8 3504 }
3505
86916870 3506 if (ssh->cfg.x11_forward) {
32874aea 3507 char proto[20], data[64];
3508 logevent("Requesting X11 forwarding");
302121de 3509 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 3510 data, sizeof(data), ssh->cfg.x11_auth);
3511 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 3512 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3513 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3514 PKT_STR, proto, PKT_STR, data,
86916870 3515 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 3516 PKT_END);
32874aea 3517 } else {
51470298 3518 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3519 PKT_STR, proto, PKT_STR, data, PKT_END);
3520 }
3521 do {
3522 crReturnV;
ff3187f6 3523 } while (!pktin);
3524 if (pktin->type != SSH1_SMSG_SUCCESS
3525 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3526 bombout(("Protocol confusion"));
7ffdbc1a 3527 crStopV;
ff3187f6 3528 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3529 logevent("X11 forwarding refused");
3530 } else {
3531 logevent("X11 forwarding enabled");
51470298 3532 ssh->X11_fwd_enabled = TRUE;
9c964e85 3533 }
3534 }
3535
d74d141c 3536 {
9bf696b1 3537 char type;
d74d141c 3538 int n;
a4fc0d74 3539 int sport,dport,sserv,dserv;
6ee9b735 3540 char sports[256], dports[256], saddr[256], host[256];
d74d141c 3541
51470298 3542 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3543 /* Add port forwardings. */
86916870 3544 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 3545 while (*ssh->portfwd_strptr) {
3546 type = *ssh->portfwd_strptr++;
6ee9b735 3547 saddr[0] = '\0';
d74d141c 3548 n = 0;
6ee9b735 3549 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3550 if (*ssh->portfwd_strptr == ':') {
3551 /*
3552 * We've seen a colon in the middle of the
3553 * source port number. This means that
3554 * everything we've seen until now is the
3555 * source _address_, so we'll move it into
3556 * saddr and start sports from the beginning
3557 * again.
3558 */
3559 ssh->portfwd_strptr++;
3560 sports[n] = '\0';
3561 strcpy(saddr, sports);
3562 n = 0;
3563 }
3564 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3565 }
d74d141c 3566 sports[n] = 0;
820ebe3b 3567 if (type != 'D') {
3568 if (*ssh->portfwd_strptr == '\t')
3569 ssh->portfwd_strptr++;
3570 n = 0;
3571 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3572 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3573 }
3574 host[n] = 0;
3575 if (*ssh->portfwd_strptr == ':')
3576 ssh->portfwd_strptr++;
3577 n = 0;
3578 while (*ssh->portfwd_strptr) {
3579 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3580 }
3581 dports[n] = 0;
51470298 3582 ssh->portfwd_strptr++;
820ebe3b 3583 dport = atoi(dports);
3584 dserv = 0;
3585 if (dport == 0) {
3586 dserv = 1;
3587 dport = net_service_lookup(dports);
3588 if (!dport) {
3589 logeventf(ssh, "Service lookup failed for"
3590 " destination port \"%s\"", dports);
3591 }
a4fc0d74 3592 }
820ebe3b 3593 } else {
3594 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 3595 dport = dserv = -1;
7d5b0f4d 3596 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 3597 }
d74d141c 3598 sport = atoi(sports);
a4fc0d74 3599 sserv = 0;
3600 if (sport == 0) {
3601 sserv = 1;
68a49acb 3602 sport = net_service_lookup(sports);
3603 if (!sport) {
57356d63 3604 logeventf(ssh, "Service lookup failed for source"
3605 " port \"%s\"", sports);
a4fc0d74 3606 }
3607 }
d74d141c 3608 if (sport && dport) {
94ab1ddf 3609 /* Set up a description of the source port. */
c61c9cdf 3610 static char *sportdesc;
3611 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
94ab1ddf 3612 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3613 (int)(*saddr?1:0), ":",
3614 (int)(sserv ? strlen(sports) : 0), sports,
3615 sserv, "(", sport, sserv, ")");
d74d141c 3616 if (type == 'L') {
94ab1ddf 3617 /* Verbose description of the destination port */
3618 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3619 host,
3620 (int)(dserv ? strlen(dports) : 0), dports,
3621 dserv, "(", dport, dserv, ")");
3622 const char *err = pfd_addforward(host, dport,
3623 *saddr ? saddr : NULL,
3624 sport, ssh, &ssh->cfg);
3625 if (err) {
3626 logeventf(ssh, "Local port %s forward to %s"
3627 " failed: %s", sportdesc, dportdesc, err);
3628 } else {
3629 logeventf(ssh, "Local port %s forwarding to %s",
3630 sportdesc, dportdesc);
3631 }
3632 sfree(dportdesc);
820ebe3b 3633 } else if (type == 'D') {
94ab1ddf 3634 const char *err = pfd_addforward(NULL, -1,
3635 *saddr ? saddr : NULL,
3636 sport, ssh, &ssh->cfg);
3637 if (err) {
3638 logeventf(ssh, "Local port %s SOCKS dynamic forward"
3639 " setup failed: %s", sportdesc, err);
3640 } else {
3641 logeventf(ssh, "Local port %s doing SOCKS"
3642 " dynamic forwarding", sportdesc);
3643 }
d74d141c 3644 } else {
3645 struct ssh_rportfwd *pf;
3d88e64d 3646 pf = snew(struct ssh_rportfwd);
bc240b21 3647 strcpy(pf->dhost, host);
3648 pf->dport = dport;
0cd494d7 3649 if (*saddr) {
6ee9b735 3650 logeventf(ssh,
3651 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3652 saddr, sport);
3653 }
51470298 3654 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 3655 logeventf(ssh,
3656 "Duplicate remote port forwarding to %s:%d",
3657 host, dport);
bc240b21 3658 sfree(pf);
d74d141c 3659 } else {
57356d63 3660 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3661 " forward to %s:%.*s%.*s%d%.*s",
3662 (int)(sserv ? strlen(sports) : 0), sports,
3663 sserv, "(", sport, sserv, ")",
3664 host,
3665 (int)(dserv ? strlen(dports) : 0), dports,
3666 dserv, "(", dport, dserv, ")");
51470298 3667 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3668 PKT_INT, sport,
3669 PKT_STR, host,
3670 PKT_INT, dport,
3671 PKT_END);
9bf696b1 3672 do {
3673 crReturnV;
ff3187f6 3674 } while (!pktin);
3675 if (pktin->type != SSH1_SMSG_SUCCESS
3676 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3677 bombout(("Protocol confusion"));
7ffdbc1a 3678 crStopV;
ff3187f6 3679 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3680 c_write_str(ssh, "Server refused port"
3681 " forwarding\r\n");
9bf696b1 3682 }
3683 logevent("Remote port forwarding enabled");
d74d141c 3684 }
3685 }
94ab1ddf 3686 sfree(sportdesc);
d74d141c 3687 }
3688 }
3689 }
3690
86916870 3691 if (!ssh->cfg.nopty) {
a5dd8467 3692 /* Unpick the terminal-speed string. */
3693 /* XXX perhaps we should allow no speeds to be sent. */
db219738 3694 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
3695 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 3696 /* Send the pty request. */
51470298 3697 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 3698 PKT_STR, ssh->cfg.termtype,
51470298 3699 PKT_INT, ssh->term_height,
3700 PKT_INT, ssh->term_width,
a5dd8467 3701 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 3702 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
3703 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 3704 PKT_CHAR, 0, PKT_END);
51470298 3705 ssh->state = SSH_STATE_INTERMED;
32874aea 3706 do {
3707 crReturnV;
ff3187f6 3708 } while (!pktin);
3709 if (pktin->type != SSH1_SMSG_SUCCESS
3710 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3711 bombout(("Protocol confusion"));
7ffdbc1a 3712 crStopV;
ff3187f6 3713 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3714 c_write_str(ssh, "Server refused to allocate pty\r\n");
3715 ssh->editing = ssh->echoing = 1;
32874aea 3716 }
a5dd8467 3717 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 3718 ssh->ospeed, ssh->ispeed);
0965bee0 3719 } else {
51470298 3720 ssh->editing = ssh->echoing = 1;
374330e2 3721 }
3722
86916870 3723 if (ssh->cfg.compression) {
51470298 3724 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 3725 do {
3726 crReturnV;
ff3187f6 3727 } while (!pktin);
3728 if (pktin->type != SSH1_SMSG_SUCCESS
3729 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3730 bombout(("Protocol confusion"));
7ffdbc1a 3731 crStopV;
ff3187f6 3732 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3733 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 3734 }
4ba9b64b 3735 logevent("Started compression");
51470298 3736 ssh->v1_compressing = TRUE;
5366aed8 3737 ssh->cs_comp_ctx = zlib_compress_init();
3738 logevent("Initialised zlib (RFC1950) compression");
3739 ssh->sc_comp_ctx = zlib_decompress_init();
3740 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 3741 }
3742
fd5e5847 3743 /*
3744 * Start the shell or command.
3745 *
3746 * Special case: if the first-choice command is an SSH2
3747 * subsystem (hence not usable here) and the second choice
3748 * exists, we fall straight back to that.
3749 */
3750 {
86916870 3751 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 3752
86916870 3753 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3754 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 3755 ssh->fallback_cmd = TRUE;
fd5e5847 3756 }
3757 if (*cmd)
51470298 3758 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 3759 else
51470298 3760 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 3761 logevent("Started session");
3762 }
374330e2 3763
51470298 3764 ssh->state = SSH_STATE_SESSION;
3765 if (ssh->size_needed)
3766 ssh_size(ssh, ssh->term_width, ssh->term_height);
3767 if (ssh->eof_needed)
3768 ssh_special(ssh, TS_EOF);
374330e2 3769
b9d7bcad 3770 if (ssh->ldisc)
3771 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 3772 ssh->send_ok = 1;
3773 ssh->channels = newtree234(ssh_channelcmp);
374330e2 3774 while (1) {
3775 crReturnV;
ff3187f6 3776 if (pktin) {
3777 if (pktin->type == SSH1_SMSG_STDOUT_DATA ||
3778 pktin->type == SSH1_SMSG_STDERR_DATA) {
0016d70b 3779 char *string;
3780 int stringlen, bufsize;
3781
ff3187f6 3782 ssh_pkt_getstring(pktin, &string, &stringlen);
0016d70b 3783 if (string == NULL) {
3784 bombout(("Incoming terminal data packet was badly formed"));
3785 crStopV;
3786 }
3787
3788 bufsize =
51470298 3789 from_backend(ssh->frontend,
ff3187f6 3790 pktin->type == SSH1_SMSG_STDERR_DATA,
0016d70b 3791 string, stringlen);
51470298 3792 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3793 ssh->v1_stdout_throttling = 1;
3794 ssh1_throttle(ssh, +1);
5471d09a 3795 }
ff3187f6 3796 } else if (pktin->type == SSH1_MSG_DISCONNECT) {
3bb2f322 3797 ssh_closing((Plug)ssh, NULL, 0, 0);
c5e9c988 3798 logevent("Received disconnect request");
7ffdbc1a 3799 crStopV;
ff3187f6 3800 } else if (pktin->type == SSH1_SMSG_X11_OPEN) {
32874aea 3801 /* Remote side is trying to open a channel to talk to our
3802 * X-Server. Give them back a local channel number. */
3803 struct ssh_channel *c;
ff3187f6 3804 int remoteid = ssh_pkt_getuint32(pktin);
9c964e85 3805
3806 logevent("Received X11 connect request");
3807 /* Refuse if X11 forwarding is disabled. */
51470298 3808 if (!ssh->X11_fwd_enabled) {
3809 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3810 PKT_INT, remoteid, PKT_END);
9c964e85 3811 logevent("Rejected X11 connect request");
3812 } else {
3d88e64d 3813 c = snew(struct ssh_channel);
51470298 3814 c->ssh = ssh;
9c964e85 3815
86916870 3816 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
e8fa8f62 3817 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
0016d70b 3818 logevent("Opening X11 forward connection failed");
32874aea 3819 sfree(c);
51470298 3820 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3821 PKT_INT, remoteid, PKT_END);
9c964e85 3822 } else {
32874aea 3823 logevent
0016d70b 3824 ("Opening X11 forward connection succeeded");
3825 c->remoteid = remoteid;
51470298 3826 c->localid = alloc_channel_id(ssh);
32874aea 3827 c->closes = 0;
5471d09a 3828 c->v.v1.throttling = 0;
32874aea 3829 c->type = CHAN_X11; /* identify channel type */
51470298 3830 add234(ssh->channels, c);
3831 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
32874aea 3832 PKT_INT, c->remoteid, PKT_INT,
3833 c->localid, PKT_END);
3834 logevent("Opened X11 forward channel");
9c964e85 3835 }
3836 }
ff3187f6 3837 } else if (pktin->type == SSH1_SMSG_AGENT_OPEN) {
32874aea 3838 /* Remote side is trying to open a channel to talk to our
3839 * agent. Give them back a local channel number. */
3840 struct ssh_channel *c;
ff3187f6 3841 int remoteid = ssh_pkt_getuint32(pktin);
db7d555c 3842
3843 /* Refuse if agent forwarding is disabled. */
51470298 3844 if (!ssh->agentfwd_enabled) {
3845 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3846 PKT_INT, remoteid, PKT_END);
db7d555c 3847 } else {
3d88e64d 3848 c = snew(struct ssh_channel);
51470298 3849 c->ssh = ssh;
0016d70b 3850 c->remoteid = remoteid;
51470298 3851 c->localid = alloc_channel_id(ssh);
db7d555c 3852 c->closes = 0;
5471d09a 3853 c->v.v1.throttling = 0;
32874aea 3854 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3855 c->u.a.lensofar = 0;
51470298 3856 add234(ssh->channels, c);
3857 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
db7d555c 3858 PKT_INT, c->remoteid, PKT_INT, c->localid,
3859 PKT_END);
3860 }
ff3187f6 3861 } else if (pktin->type == SSH1_MSG_PORT_OPEN) {
d74d141c 3862 /* Remote side is trying to open a channel to talk to a
3863 * forwarded port. Give them back a local channel number. */
3864 struct ssh_channel *c;
3865 struct ssh_rportfwd pf;
0016d70b 3866 int remoteid;
d74d141c 3867 int hostsize, port;
0016d70b 3868 char *host, buf[1024];
cbe2d68f 3869 const char *e;
3d88e64d 3870 c = snew(struct ssh_channel);
51470298 3871 c->ssh = ssh;
d74d141c 3872
ff3187f6 3873 remoteid = ssh_pkt_getuint32(pktin);
3874 ssh_pkt_getstring(pktin, &host, &hostsize);
3875 port = ssh_pkt_getuint32(pktin);
d74d141c 3876
0016d70b 3877 if (hostsize >= lenof(pf.dhost))
3878 hostsize = lenof(pf.dhost)-1;
3879 memcpy(pf.dhost, host, hostsize);
3880 pf.dhost[hostsize] = '\0';
bc240b21 3881 pf.dport = port;
d74d141c 3882
51470298 3883 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
d74d141c 3884 sprintf(buf, "Rejected remote port open request for %s:%d",
0016d70b 3885 pf.dhost, port);
d74d141c 3886 logevent(buf);
51470298 3887 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3888 PKT_INT, remoteid, PKT_END);
d74d141c 3889 } else {
3890 sprintf(buf, "Received remote port open request for %s:%d",
0016d70b 3891 pf.dhost, port);
d74d141c 3892 logevent(buf);
0016d70b 3893 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3894 c, &ssh->cfg);
d74d141c 3895 if (e != NULL) {
3896 char buf[256];
3897 sprintf(buf, "Port open failed: %s", e);
3898 logevent(buf);
3899 sfree(c);
51470298 3900 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
0016d70b 3901 PKT_INT, remoteid, PKT_END);
d74d141c 3902 } else {
0016d70b 3903 c->remoteid = remoteid;
51470298 3904 c->localid = alloc_channel_id(ssh);
d74d141c 3905 c->closes = 0;
5471d09a 3906 c->v.v1.throttling = 0;
d74d141c 3907 c->type = CHAN_SOCKDATA; /* identify channel type */
51470298 3908 add234(ssh->channels, c);
3909 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
d74d141c 3910 PKT_INT, c->remoteid, PKT_INT,
3911 c->localid, PKT_END);
3912 logevent("Forwarded port opened successfully");
3913 }
3914 }
3915
ff3187f6 3916 } else if (pktin->type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3917 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3918 unsigned int localid = ssh_pkt_getuint32(pktin);
bc240b21 3919 struct ssh_channel *c;
3920
51470298 3921 c = find234(ssh->channels, &remoteid, ssh_channelfind);
bc240b21 3922 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3923 c->remoteid = localid;
3924 c->type = CHAN_SOCKDATA;
7781f316 3925 c->v.v1.throttling = 0;
bc240b21 3926 pfd_confirm(c->u.pfd.s);
3927 }
d74d141c 3928
4ed34d25 3929 if (c && c->closes) {
3930 /*
3931 * We have a pending close on this channel,
3932 * which we decided on before the server acked
3933 * the channel open. So now we know the
3934 * remoteid, we can close it again.
3935 */
51470298 3936 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3937 PKT_INT, c->remoteid, PKT_END);
4ed34d25 3938 }
3939
ff3187f6 3940 } else if (pktin->type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3941 unsigned int remoteid = ssh_pkt_getuint32(pktin);
724cface 3942 struct ssh_channel *c;
3943
51470298 3944 c = find234(ssh->channels, &remoteid, ssh_channelfind);
724cface 3945 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3946 logevent("Forwarded connection refused by server");
3947 pfd_close(c->u.pfd.s);
51470298 3948 del234(ssh->channels, c);
724cface 3949 sfree(c);
3950 }
3951
ff3187f6 3952 } else if (pktin->type == SSH1_MSG_CHANNEL_CLOSE ||
3953 pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3954 /* Remote side closes a channel. */
ff3187f6 3955 unsigned i = ssh_pkt_getuint32(pktin);
32874aea 3956 struct ssh_channel *c;
51470298 3957 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 3958 if (c && ((int)c->remoteid) != -1) {
32874aea 3959 int closetype;
3960 closetype =
ff3187f6 3961 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3962
783415f8 3963 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3964 logevent("Forwarded X11 connection terminated");
9c964e85 3965 assert(c->u.x11.s != NULL);
3966 x11_close(c->u.x11.s);
3967 c->u.x11.s = NULL;
3968 }
d74d141c 3969 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3970 logevent("Forwarded port closed");
3971 assert(c->u.pfd.s != NULL);
3972 pfd_close(c->u.pfd.s);
3973 c->u.pfd.s = NULL;
3974 }
0357890f 3975
3976 c->closes |= (closetype << 2); /* seen this message */
3977 if (!(c->closes & closetype)) {
ff3187f6 3978 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
0357890f 3979 PKT_END);
3980 c->closes |= closetype; /* sent it too */
3981 }
3982
3983 if (c->closes == 15) {
51470298 3984 del234(ssh->channels, c);
32874aea 3985 sfree(c);
3986 }
d0d844c1 3987 } else {
6b5cf8b4 3988 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
ff3187f6 3989 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
d0d844c1 3990 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3991 i));
7ffdbc1a 3992 crStopV;
32874aea 3993 }
ff3187f6 3994 } else if (pktin->type == SSH1_MSG_CHANNEL_DATA) {
32874aea 3995 /* Data sent down one of our channels. */
ff3187f6 3996 int i = ssh_pkt_getuint32(pktin);
0016d70b 3997 char *p;
3998 int len;
32874aea 3999 struct ssh_channel *c;
0016d70b 4000
ff3187f6 4001 ssh_pkt_getstring(pktin, &p, &len);
0016d70b 4002
51470298 4003 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 4004 if (c) {
7ffdbc1a 4005 int bufsize = 0;
32874aea 4006 switch (c->type) {
4007 case CHAN_X11:
0016d70b 4008 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 4009 break;
d74d141c 4010 case CHAN_SOCKDATA:
0016d70b 4011 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 4012 break;
32874aea 4013 case CHAN_AGENT:
4014 /* Data for an agent message. Buffer it. */
4015 while (len > 0) {
4016 if (c->u.a.lensofar < 4) {
4017 int l = min(4 - c->u.a.lensofar, len);
4018 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4019 l);
4020 p += l;
4021 len -= l;
4022 c->u.a.lensofar += l;
4023 }
4024 if (c->u.a.lensofar == 4) {
4025 c->u.a.totallen =
4026 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 4027 c->u.a.message = snewn(c->u.a.totallen,
4028 unsigned char);
32874aea 4029 memcpy(c->u.a.message, c->u.a.msglen, 4);
4030 }
4031 if (c->u.a.lensofar >= 4 && len > 0) {
4032 int l =
4033 min(c->u.a.totallen - c->u.a.lensofar,
4034 len);
4035 memcpy(c->u.a.message + c->u.a.lensofar, p,
4036 l);
4037 p += l;
4038 len -= l;
4039 c->u.a.lensofar += l;
4040 }
4041 if (c->u.a.lensofar == c->u.a.totallen) {
839f10db 4042 void *reply;
32874aea 4043 int replylen;
839f10db 4044 if (agent_query(c->u.a.message,
4045 c->u.a.totallen,
4046 &reply, &replylen,
4047 ssh_agentf_callback, c))
4048 ssh_agentf_callback(c, reply, replylen);
32874aea 4049 sfree(c->u.a.message);
4050 c->u.a.lensofar = 0;
4051 }
4052 }
5471d09a 4053 bufsize = 0; /* agent channels never back up */
32874aea 4054 break;
4055 }
90347b95 4056 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 4057 c->v.v1.throttling = 1;
51470298 4058 ssh1_throttle(ssh, +1);
5471d09a 4059 }
32874aea 4060 }
ff3187f6 4061 } else if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4062 /* may be from EXEC_SHELL on some servers */
ff3187f6 4063 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4064 /* may be from EXEC_SHELL on some servers
374330e2 4065 * if no pty is available or in other odd cases. Ignore */
ff3187f6 4066 } else if (pktin->type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 4067 char buf[100];
ff3187f6 4068 ssh->exitcode = ssh_pkt_getuint32(pktin);
d8d6c7e5 4069 sprintf(buf, "Server sent command exit status %d",
51470298 4070 ssh->exitcode);
d8d6c7e5 4071 logevent(buf);
51470298 4072 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 4073 /*
4074 * In case `helpful' firewalls or proxies tack
4075 * extra human-readable text on the end of the
4076 * session which we might mistake for another
4077 * encrypted packet, we close the session once
4078 * we've sent EXIT_CONFIRMATION.
4079 */
3bb2f322 4080 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 4081 crStopV;
374330e2 4082 } else {
ff3187f6 4083 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4084 crStopV;
374330e2 4085 }
4086 } else {
8df7a775 4087 while (inlen > 0) {
4088 int len = min(inlen, 512);
9a10ecf4 4089 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4090 PKT_INT, len, PKT_DATA, in, len,
4091 PKTT_OTHER, PKT_END);
8df7a775 4092 in += len;
4093 inlen -= len;
4094 }
374330e2 4095 }
4096 }
4097
4098 crFinishV;
4099}
4100
4101/*
b09eaa88 4102 * Handle the top-level SSH2 protocol.
4103 */
4104static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4105{
4106 char *buf, *msg;
4107 int msglen;
4108
4109 ssh_pkt_getstring(pktin, &msg, &msglen);
4110 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4111 logevent(buf);
4112 sfree(buf);
4113}
4114
4115static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4116{
4117 /* log reason code in disconnect message */
4118 char *msg;
4119 int msglen;
4120
4121 ssh_pkt_getstring(pktin, &msg, &msglen);
4122 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4123}
4124
4125void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4126{
4127 /* Do nothing, because we're ignoring it! Duhh. */
4128}
4129
4130static void ssh1_protocol_setup(Ssh ssh)
4131{
4132 int i;
4133
4134 /*
4135 * Most messages are handled by the coroutines.
4136 */
4137 for (i = 0; i < 256; i++)
4138 ssh->packet_dispatch[i] = NULL;
4139
4140 /*
4141 * These special message types we install handlers for.
4142 */
4143 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4144 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4145 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4146}
4147
4148static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4149 struct Packet *pktin)
4150{
4151 if (ssh->state == SSH_STATE_CLOSED)
4152 return;
4153
4154 if (pktin && ssh->packet_dispatch[pktin->type]) {
4155 ssh->packet_dispatch[pktin->type](ssh, pktin);
4156 return;
4157 }
4158
4159 if (!ssh->protocol_initial_phase_done) {
4160 if (do_ssh1_login(ssh, in, inlen, pktin))
4161 ssh->protocol_initial_phase_done = TRUE;
4162 else
4163 return;
4164 }
4165
4166 do_ssh1_connection(ssh, in, inlen, pktin);
4167}
4168
4169/*
e5574168 4170 * Utility routine for decoding comma-separated strings in KEXINIT.
4171 */
32874aea 4172static int in_commasep_string(char *needle, char *haystack, int haylen)
4173{
57356d63 4174 int needlen;
4175 if (!needle || !haystack) /* protect against null pointers */
4176 return 0;
4177 needlen = strlen(needle);
e5574168 4178 while (1) {
32874aea 4179 /*
4180 * Is it at the start of the string?
4181 */
4182 if (haylen >= needlen && /* haystack is long enough */
4183 !memcmp(needle, haystack, needlen) && /* initial match */
4184 (haylen == needlen || haystack[needlen] == ',')
4185 /* either , or EOS follows */
4186 )
4187 return 1;
4188 /*
4189 * If not, search for the next comma and resume after that.
4190 * If no comma found, terminate.
4191 */
4192 while (haylen > 0 && *haystack != ',')
4193 haylen--, haystack++;
4194 if (haylen == 0)
4195 return 0;
4196 haylen--, haystack++; /* skip over comma itself */
e5574168 4197 }
4198}
4199
4200/*
d39f364a 4201 * SSH2 key creation method.
4202 */
d8baa528 4203static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4204 unsigned char *sessid, char chr,
4205 unsigned char *keyspace)
32874aea 4206{
d39f364a 4207 SHA_State s;
4208 /* First 20 bytes. */
4209 SHA_Init(&s);
51470298 4210 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4211 sha_mpint(&s, K);
d39f364a 4212 SHA_Bytes(&s, H, 20);
4213 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4214 SHA_Bytes(&s, sessid, 20);
d39f364a 4215 SHA_Final(&s, keyspace);
4216 /* Next 20 bytes. */
4217 SHA_Init(&s);
51470298 4218 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4219 sha_mpint(&s, K);
d39f364a 4220 SHA_Bytes(&s, H, 20);
4221 SHA_Bytes(&s, keyspace, 20);
32874aea 4222 SHA_Final(&s, keyspace + 20);
d39f364a 4223}
4224
4225/*
7cca0d81 4226 * Handle the SSH2 transport layer.
e5574168 4227 */
ff3187f6 4228static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4229 struct Packet *pktin)
e5574168 4230{
51470298 4231 struct do_ssh2_transport_state {
4232 int nbits, pbits, warn;
4233 Bignum p, g, e, f, K;
4234 int kex_init_value, kex_reply_value;
4235 const struct ssh_mac **maclist;
4236 int nmacs;
4237 const struct ssh2_cipher *cscipher_tobe;
4238 const struct ssh2_cipher *sccipher_tobe;
4239 const struct ssh_mac *csmac_tobe;
4240 const struct ssh_mac *scmac_tobe;
4241 const struct ssh_compress *cscomp_tobe;
4242 const struct ssh_compress *sccomp_tobe;
4243 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4244 int hostkeylen, siglen;
4245 void *hkey; /* actual host key */
4246 unsigned char exchange_hash[20];
4247 int n_preferred_ciphers;
4248 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4249 const struct ssh_compress *preferred_comp;
4250 int first_kex;
ff3187f6 4251 struct Packet *pktout;
51470298 4252 };
4253 crState(do_ssh2_transport_state);
4254
4255 crBegin(ssh->do_ssh2_transport_crstate);
4256
4257 s->cscipher_tobe = s->sccipher_tobe = NULL;
4258 s->csmac_tobe = s->scmac_tobe = NULL;
4259 s->cscomp_tobe = s->sccomp_tobe = NULL;
4260
7cca0d81 4261 random_init();
51470298 4262 s->first_kex = 1;
e5574168 4263
51470298 4264 {
4265 int i;
4266 /*
4267 * Set up the preferred ciphers. (NULL => warn below here)
4268 */
4269 s->n_preferred_ciphers = 0;
4270 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4271 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4272 case CIPHER_BLOWFISH:
4273 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4274 break;
4275 case CIPHER_DES:
86916870 4276 if (ssh->cfg.ssh2_des_cbc) {
51470298 4277 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4278 }
4279 break;
4280 case CIPHER_3DES:
4281 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4282 break;
4283 case CIPHER_AES:
4284 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4285 break;
4286 case CIPHER_WARN:
4287 /* Flag for later. Don't bother if it's the last in
4288 * the list. */
4289 if (i < CIPHER_MAX - 1) {
4290 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4291 }
4292 break;
ca20bfcf 4293 }
ca20bfcf 4294 }
5e8358ad 4295 }
ca20bfcf 4296
4297 /*
4298 * Set up preferred compression.
4299 */
86916870 4300 if (ssh->cfg.compression)
51470298 4301 s->preferred_comp = &ssh_zlib;
4ba9b64b 4302 else
51470298 4303 s->preferred_comp = &ssh_comp_none;
5e8358ad 4304
7591b9ff 4305 /*
4306 * Be prepared to work around the buggy MAC problem.
4307 */
51470298 4308 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4309 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 4310 else
51470298 4311 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 4312
32874aea 4313 begin_key_exchange:
51470298 4314 {
4315 int i, j, cipherstr_started;
4316
4317 /*
590f6a5f 4318 * Enable queueing of outgoing auth- or connection-layer
4319 * packets while we are in the middle of a key exchange.
4320 */
4321 ssh->queueing = TRUE;
4322
4323 /*
9442dd57 4324 * Flag that KEX is in progress.
4325 */
4326 ssh->kex_in_progress = TRUE;
4327
4328 /*
51470298 4329 * Construct and send our key exchange packet.
4330 */
ff3187f6 4331 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4332 for (i = 0; i < 16; i++)
ff3187f6 4333 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4334 /* List key exchange algorithms. */
ff3187f6 4335 ssh2_pkt_addstring_start(s->pktout);
51470298 4336 for (i = 0; i < lenof(kex_algs); i++) {
4337 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4338 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4339 continue;
ff3187f6 4340 ssh2_pkt_addstring_str(s->pktout, kex_algs[i]->name);
51470298 4341 if (i < lenof(kex_algs) - 1)
ff3187f6 4342 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4343 }
51470298 4344 /* List server host key algorithms. */
ff3187f6 4345 ssh2_pkt_addstring_start(s->pktout);
51470298 4346 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4347 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4348 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4349 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4350 }
51470298 4351 /* List client->server encryption algorithms. */
ff3187f6 4352 ssh2_pkt_addstring_start(s->pktout);
51470298 4353 cipherstr_started = 0;
4354 for (i = 0; i < s->n_preferred_ciphers; i++) {
4355 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4356 if (!c) continue; /* warning flag */
4357 for (j = 0; j < c->nciphers; j++) {
4358 if (cipherstr_started)
ff3187f6 4359 ssh2_pkt_addstring_str(s->pktout, ",");
4360 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
51470298 4361 cipherstr_started = 1;
4362 }
4363 }
4364 /* List server->client encryption algorithms. */
ff3187f6 4365 ssh2_pkt_addstring_start(s->pktout);
51470298 4366 cipherstr_started = 0;
4367 for (i = 0; i < s->n_preferred_ciphers; i++) {
4368 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4369 if (!c) continue; /* warning flag */
4370 for (j = 0; j < c->nciphers; j++) {
4371 if (cipherstr_started)
ff3187f6 4372 ssh2_pkt_addstring_str(s->pktout, ",");
4373 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
51470298 4374 cipherstr_started = 1;
4375 }
4376 }
4377 /* List client->server MAC algorithms. */
ff3187f6 4378 ssh2_pkt_addstring_start(s->pktout);
51470298 4379 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4380 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4381 if (i < s->nmacs - 1)
ff3187f6 4382 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4383 }
4384 /* List server->client MAC algorithms. */
ff3187f6 4385 ssh2_pkt_addstring_start(s->pktout);
51470298 4386 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4387 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4388 if (i < s->nmacs - 1)
ff3187f6 4389 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4390 }
4391 /* List client->server compression algorithms. */
ff3187f6 4392 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4393 assert(lenof(compressions) > 1);
ff3187f6 4394 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4395 for (i = 0; i < lenof(compressions); i++) {
4396 const struct ssh_compress *c = compressions[i];
4397 if (c != s->preferred_comp) {
ff3187f6 4398 ssh2_pkt_addstring_str(s->pktout, ",");
4399 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4400 }
51470298 4401 }
4402 /* List server->client compression algorithms. */
ff3187f6 4403 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4404 assert(lenof(compressions) > 1);
ff3187f6 4405 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4406 for (i = 0; i < lenof(compressions); i++) {
4407 const struct ssh_compress *c = compressions[i];
4408 if (c != s->preferred_comp) {
ff3187f6 4409 ssh2_pkt_addstring_str(s->pktout, ",");
4410 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4411 }
51470298 4412 }
4413 /* List client->server languages. Empty list. */
ff3187f6 4414 ssh2_pkt_addstring_start(s->pktout);
51470298 4415 /* List server->client languages. Empty list. */
ff3187f6 4416 ssh2_pkt_addstring_start(s->pktout);
51470298 4417 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4418 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4419 /* Reserved. */
ff3187f6 4420 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4421 }
0db56f73 4422
51470298 4423 ssh->exhash = ssh->exhashbase;
ff3187f6 4424 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4425
590f6a5f 4426 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4427
ff3187f6 4428 if (!pktin)
4429 crWaitUntil(pktin);
4430 if (pktin->length > 5)
4431 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4432
4433 /*
4434 * Now examine the other side's KEXINIT to see what we're up
4435 * to.
4436 */
51470298 4437 {
4438 char *str;
4439 int i, j, len;
4440
ff3187f6 4441 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4442 bombout(("expected key exchange packet from server"));
7ffdbc1a 4443 crStop(0);
32874aea 4444 }
51470298 4445 ssh->kex = NULL;
4446 ssh->hostkey = NULL;
4447 s->cscipher_tobe = NULL;
4448 s->sccipher_tobe = NULL;
4449 s->csmac_tobe = NULL;
4450 s->scmac_tobe = NULL;
4451 s->cscomp_tobe = NULL;
4452 s->sccomp_tobe = NULL;
ff3187f6 4453 pktin->savedpos += 16; /* skip garbage cookie */
4454 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
51470298 4455 for (i = 0; i < lenof(kex_algs); i++) {
4456 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4457 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4458 continue;
4459 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4460 ssh->kex = kex_algs[i];
4461 break;
4462 }
32874aea 4463 }
ff3187f6 4464 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4465 for (i = 0; i < lenof(hostkey_algs); i++) {
4466 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4467 ssh->hostkey = hostkey_algs[i];
4468 break;
4469 }
4470 }
ff3187f6 4471 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4472 s->warn = 0;
4473 for (i = 0; i < s->n_preferred_ciphers; i++) {
4474 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4475 if (!c) {
4476 s->warn = 1;
4477 } else {
4478 for (j = 0; j < c->nciphers; j++) {
4479 if (in_commasep_string(c->list[j]->name, str, len)) {
4480 s->cscipher_tobe = c->list[j];
4481 break;
4482 }
ca20bfcf 4483 }
32874aea 4484 }
51470298 4485 if (s->cscipher_tobe) {
4486 if (s->warn)
a8327734 4487 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 4488 break;
4489 }
32874aea 4490 }
51470298 4491 if (!s->cscipher_tobe) {
6b5cf8b4 4492 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4493 str ? str : "(null)"));
7ffdbc1a 4494 crStop(0);
ca20bfcf 4495 }
0ef8f407 4496
ff3187f6 4497 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4498 s->warn = 0;
4499 for (i = 0; i < s->n_preferred_ciphers; i++) {
4500 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4501 if (!c) {
4502 s->warn = 1;
4503 } else {
4504 for (j = 0; j < c->nciphers; j++) {
4505 if (in_commasep_string(c->list[j]->name, str, len)) {
4506 s->sccipher_tobe = c->list[j];
4507 break;
4508 }
ca20bfcf 4509 }
32874aea 4510 }
51470298 4511 if (s->sccipher_tobe) {
4512 if (s->warn)
a8327734 4513 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 4514 break;
4515 }
32874aea 4516 }
51470298 4517 if (!s->sccipher_tobe) {
6b5cf8b4 4518 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4519 str ? str : "(null)"));
7ffdbc1a 4520 crStop(0);
ca20bfcf 4521 }
0ef8f407 4522
ff3187f6 4523 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 4524 for (i = 0; i < s->nmacs; i++) {
4525 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4526 s->csmac_tobe = s->maclist[i];
4527 break;
4528 }
32874aea 4529 }
ff3187f6 4530 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 4531 for (i = 0; i < s->nmacs; i++) {
4532 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4533 s->scmac_tobe = s->maclist[i];
4534 break;
4535 }
32874aea 4536 }
ff3187f6 4537 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 4538 for (i = 0; i < lenof(compressions) + 1; i++) {
4539 const struct ssh_compress *c =
4540 i == 0 ? s->preferred_comp : compressions[i - 1];
4541 if (in_commasep_string(c->name, str, len)) {
4542 s->cscomp_tobe = c;
4543 break;
4544 }
32874aea 4545 }
ff3187f6 4546 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 4547 for (i = 0; i < lenof(compressions) + 1; i++) {
4548 const struct ssh_compress *c =
4549 i == 0 ? s->preferred_comp : compressions[i - 1];
4550 if (in_commasep_string(c->name, str, len)) {
4551 s->sccomp_tobe = c;
4552 break;
4553 }
32874aea 4554 }
e5574168 4555 }
e5574168 4556
4557 /*
7bd5a860 4558 * Work out the number of bits of key we will need from the key
4559 * exchange. We start with the maximum key length of either
4560 * cipher...
4561 */
4562 {
32874aea 4563 int csbits, scbits;
7bd5a860 4564
51470298 4565 csbits = s->cscipher_tobe->keylen;
4566 scbits = s->sccipher_tobe->keylen;
4567 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 4568 }
4569 /* The keys only have 160-bit entropy, since they're based on
4570 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 4571 if (s->nbits > 160)
4572 s->nbits = 160;
7bd5a860 4573
4574 /*
a92dd380 4575 * If we're doing Diffie-Hellman group exchange, start by
4576 * requesting a group.
e5574168 4577 */
51470298 4578 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 4579 logevent("Doing Diffie-Hellman group exchange");
51470298 4580 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 4581 /*
4582 * Work out how big a DH group we will need to allow that
4583 * much data.
7bd5a860 4584 */
51470298 4585 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 4586 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
4587 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 4588 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 4589
ff3187f6 4590 crWaitUntil(pktin);
4591 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 4592 bombout(("expected key exchange group packet from server"));
7ffdbc1a 4593 crStop(0);
32874aea 4594 }
ff3187f6 4595 s->p = ssh2_pkt_getmp(pktin);
4596 s->g = ssh2_pkt_getmp(pktin);
4597 if (!s->p || !s->g) {
4598 bombout(("unable to read mp-ints from incoming group packet"));
4599 crStop(0);
4600 }
27cd7fc2 4601 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 4602 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4603 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 4604 } else {
51470298 4605 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 4606 ssh->kex_ctx = dh_setup_group1();
51470298 4607 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4608 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 4609 }
e5574168 4610
a92dd380 4611 logevent("Doing Diffie-Hellman key exchange");
e5574168 4612 /*
a92dd380 4613 * Now generate and send e for Diffie-Hellman.
e5574168 4614 */
27cd7fc2 4615 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 4616 s->pktout = ssh2_pkt_init(s->kex_init_value);
4617 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 4618 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4619
ff3187f6 4620 crWaitUntil(pktin);
4621 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 4622 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 4623 crStop(0);
7cca0d81 4624 }
ff3187f6 4625 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
4626 s->f = ssh2_pkt_getmp(pktin);
4627 if (!s->f) {
4628 bombout(("unable to parse key exchange reply packet"));
4629 crStop(0);
4630 }
4631 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 4632
27cd7fc2 4633 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4634
51470298 4635 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4636 if (ssh->kex == &ssh_diffiehellman_gex) {
4637 sha_uint32(&ssh->exhash, s->pbits);
4638 sha_mpint(&ssh->exhash, s->p);
4639 sha_mpint(&ssh->exhash, s->g);
a92dd380 4640 }
51470298 4641 sha_mpint(&ssh->exhash, s->e);
4642 sha_mpint(&ssh->exhash, s->f);
4643 sha_mpint(&ssh->exhash, s->K);
4644 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4645
27cd7fc2 4646 dh_cleanup(ssh->kex_ctx);
fabd1805 4647 ssh->kex_ctx = NULL;
3709bfe9 4648
7cca0d81 4649#if 0
765c4200 4650 debug(("Exchange hash is:\n"));
51470298 4651 dmemdump(s->exchange_hash, 20);
7cca0d81 4652#endif
4653
51470298 4654 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4655 if (!s->hkey ||
4656 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 4657 (char *)s->exchange_hash, 20)) {
6b5cf8b4 4658 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 4659 crStop(0);
8d5de777 4660 }
e5574168 4661
4662 /*
7cca0d81 4663 * Authenticate remote host: verify host key. (We've already
4664 * checked the signature of the exchange hash.)
e5574168 4665 */
51470298 4666 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4667 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4668 verify_ssh_host_key(ssh->frontend,
4669 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4670 s->keystr, s->fingerprint);
4671 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4672 logevent("Host key fingerprint is:");
51470298 4673 logevent(s->fingerprint);
5e0d7cb8 4674 }
51470298 4675 sfree(s->fingerprint);
4676 sfree(s->keystr);
4677 ssh->hostkey->freekey(s->hkey);
d39f364a 4678
4679 /*
9442dd57 4680 * The exchange hash from the very first key exchange is also
4681 * the session id, used in session key construction and
4682 * authentication.
4683 */
4684 if (s->first_kex)
4685 memcpy(ssh->v2_session_id, s->exchange_hash,
4686 sizeof(s->exchange_hash));
4687
4688 /*
7cca0d81 4689 * Send SSH2_MSG_NEWKEYS.
d39f364a 4690 */
ff3187f6 4691 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 4692 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 4693 ssh->outgoing_data_size = 0; /* start counting from here */
4694
4695 /*
4696 * We've sent client NEWKEYS, so create and initialise
4697 * client-to-servere session keys.
4698 */
4699 if (ssh->cs_cipher_ctx)
4700 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4701 ssh->cscipher = s->cscipher_tobe;
4702 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4703
4704 if (ssh->cs_mac_ctx)
4705 ssh->csmac->free_context(ssh->cs_mac_ctx);
4706 ssh->csmac = s->csmac_tobe;
4707 ssh->cs_mac_ctx = ssh->csmac->make_context();
4708
4709 if (ssh->cs_comp_ctx)
4710 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4711 ssh->cscomp = s->cscomp_tobe;
4712 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4713
4714 /*
4715 * Set IVs on client-to-server keys. Here we use the exchange
4716 * hash from the _first_ key exchange.
4717 */
4718 {
4719 unsigned char keyspace[40];
4720 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4721 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4722 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4723 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4724 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4725 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4726 }
4727
4728 logeventf(ssh, "Initialised %.200s client->server encryption",
4729 ssh->cscipher->text_name);
4730 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4731 ssh->csmac->text_name);
4732 if (ssh->cscomp->text_name)
4733 logeventf(ssh, "Initialised %s compression",
4734 ssh->cscomp->text_name);
590f6a5f 4735
4736 /*
4737 * Now our end of the key exchange is complete, we can send all
4738 * our queued higher-layer packets.
4739 */
4740 ssh->queueing = FALSE;
4741 ssh2_pkt_queuesend(ssh);
d39f364a 4742
4743 /*
8406eaf9 4744 * Expect SSH2_MSG_NEWKEYS from server.
4745 */
ff3187f6 4746 crWaitUntil(pktin);
4747 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 4748 bombout(("expected new-keys packet from server"));
7ffdbc1a 4749 crStop(0);
8406eaf9 4750 }
9442dd57 4751 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 4752
4753 /*
9442dd57 4754 * We've seen server NEWKEYS, so create and initialise
4755 * server-to-client session keys.
d39f364a 4756 */
371e569c 4757 if (ssh->sc_cipher_ctx)
4758 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4759 ssh->sccipher = s->sccipher_tobe;
371e569c 4760 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4761
e0e1a00d 4762 if (ssh->sc_mac_ctx)
4763 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4764 ssh->scmac = s->scmac_tobe;
e0e1a00d 4765 ssh->sc_mac_ctx = ssh->scmac->make_context();
4766
5366aed8 4767 if (ssh->sc_comp_ctx)
4768 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4769 ssh->sccomp = s->sccomp_tobe;
5366aed8 4770 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4771
d39f364a 4772 /*
9442dd57 4773 * Set IVs on server-to-client keys. Here we use the exchange
4774 * hash from the _first_ key exchange.
d39f364a 4775 */
51470298 4776 {
4777 unsigned char keyspace[40];
51470298 4778 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4779 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4780 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4781 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4782 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4783 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4784 }
57356d63 4785 logeventf(ssh, "Initialised %.200s server->client encryption",
4786 ssh->sccipher->text_name);
6c135243 4787 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4788 ssh->scmac->text_name);
57356d63 4789 if (ssh->sccomp->text_name)
4790 logeventf(ssh, "Initialised %s decompression",
4791 ssh->sccomp->text_name);
9442dd57 4792
4793 /*
4794 * Free key exchange data.
4795 */
679539d7 4796 freebn(s->f);
679539d7 4797 freebn(s->K);
b3949e7e 4798 if (ssh->kex == &ssh_diffiehellman_gex) {
4799 freebn(s->g);
4800 freebn(s->p);
4801 }
d39f364a 4802
033b4cef 4803 /*
9442dd57 4804 * Key exchange is over. Schedule a timer for our next rekey.
4805 */
4806 ssh->kex_in_progress = FALSE;
4807 ssh->next_rekey = schedule_timer(REKEY_TIMEOUT, ssh2_timer, ssh);
4808
4809 /*
0db56f73 4810 * If this is the first key exchange phase, we must pass the
4811 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4812 * wants to see it but because it will need time to initialise
4813 * itself before it sees an actual packet. In subsequent key
4814 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4815 * it would only confuse the layer above.
4816 */
51470298 4817 if (!s->first_kex) {
b09eaa88 4818 crReturn(1);
0db56f73 4819 }
51470298 4820 s->first_kex = 0;
0db56f73 4821
4822 /*
7cca0d81 4823 * Now we're encrypting. Begin returning 1 to the protocol main
4824 * function so that other things can run on top of the
4825 * transport. If we ever see a KEXINIT, we must go back to the
4826 * start.
9442dd57 4827 *
4828 * We _also_ go back to the start if we see pktin==NULL and
4829 * inlen==-1, because this is a special signal meaning
4830 * `initiate client-driven rekey', and `in' contains a message
4831 * giving the reason for the rekey.
033b4cef 4832 */
9442dd57 4833 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
4834 (!pktin && inlen == -1))) {
32874aea 4835 crReturn(1);
e96adf72 4836 }
9442dd57 4837 if (pktin) {
4838 logevent("Server initiated key re-exchange");
4839 } else {
4840 logevent((char *)in);
4841 }
7cca0d81 4842 goto begin_key_exchange;
e5574168 4843
4844 crFinish(1);
4845}
4846
7cca0d81 4847/*
783415f8 4848 * Add data to an SSH2 channel output buffer.
4849 */
32874aea 4850static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4851 int len)
4852{
5471d09a 4853 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4854}
4855
4856/*
4857 * Attempt to send data on an SSH2 channel.
4858 */
5471d09a 4859static int ssh2_try_send(struct ssh_channel *c)
32874aea 4860{
51470298 4861 Ssh ssh = c->ssh;
ff3187f6 4862 struct Packet *pktout;
51470298 4863
5471d09a 4864 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4865 int len;
4866 void *data;
4867 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4868 if ((unsigned)len > c->v.v2.remwindow)
4869 len = c->v.v2.remwindow;
4870 if ((unsigned)len > c->v.v2.remmaxpkt)
4871 len = c->v.v2.remmaxpkt;
ff3187f6 4872 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4873 ssh2_pkt_adduint32(pktout, c->remoteid);
4874 dont_log_data(ssh, pktout, PKTLOG_OMIT);
4875 ssh2_pkt_addstring_start(pktout);
4876 ssh2_pkt_addstring_data(pktout, data, len);
4877 end_log_omission(ssh, pktout);
4878 ssh2_pkt_send(ssh, pktout);
5471d09a 4879 bufchain_consume(&c->v.v2.outbuffer, len);
4880 c->v.v2.remwindow -= len;
4881 }
4882
4883 /*
4884 * After having sent as much data as we can, return the amount
4885 * still buffered.
4886 */
4887 return bufchain_size(&c->v.v2.outbuffer);
4888}
4889
4890/*
4891 * Potentially enlarge the window on an SSH2 channel.
4892 */
4893static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4894{
51470298 4895 Ssh ssh = c->ssh;
4896
6b69f42e 4897 /*
4898 * Never send WINDOW_ADJUST for a channel that the remote side
4899 * already thinks it's closed; there's no point, since it won't
4900 * be sending any more data anyway.
4901 */
4902 if (c->closes != 0)
4903 return;
4904
5471d09a 4905 if (newwin > c->v.v2.locwindow) {
ff3187f6 4906 struct Packet *pktout;
4907
4908 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4909 ssh2_pkt_adduint32(pktout, c->remoteid);
4910 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
4911 ssh2_pkt_send(ssh, pktout);
5471d09a 4912 c->v.v2.locwindow = newwin;
783415f8 4913 }
4914}
4915
b09eaa88 4916void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
4917{
4918 unsigned i = ssh_pkt_getuint32(pktin);
4919 struct ssh_channel *c;
4920 c = find234(ssh->channels, &i, ssh_channelfind);
4921 if (c && !c->closes)
4922 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
4923}
4924
783415f8 4925/*
7cca0d81 4926 * Handle the SSH2 userauth and connection layers.
4927 */
ff3187f6 4928static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
4929 struct Packet *pktin)
7cca0d81 4930{
51470298 4931 struct do_ssh2_authconn_state {
4932 enum {
4933 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4934 AUTH_PASSWORD,
4935 AUTH_KEYBOARD_INTERACTIVE
4936 } method;
4937 enum {
4938 AUTH_TYPE_NONE,
4939 AUTH_TYPE_PUBLICKEY,
4940 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4941 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4942 AUTH_TYPE_PASSWORD,
4943 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4944 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4945 } type;
4946 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4947 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4948 int kbd_inter_running;
4949 int we_are_in;
4950 int num_prompts, curr_prompt, echo;
4951 char username[100];
4952 int got_username;
85fdbe25 4953 char pwprompt[512];
51470298 4954 char password[100];
4955 void *publickey_blob;
4956 int publickey_bloblen;
4957 unsigned char request[5], *response, *p;
4958 int responselen;
4959 int keyi, nkeys;
4960 int authed;
4961 char *pkblob, *alg, *commentp;
4962 int pklen, alglen, commentlen;
4963 int siglen, retlen, len;
4964 char *q, *agentreq, *ret;
4965 int try_send;
73feed4f 4966 int num_env, env_left, env_ok;
ff3187f6 4967 struct Packet *pktout;
51470298 4968 };
4969 crState(do_ssh2_authconn_state);
4970
4971 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 4972
7cca0d81 4973 /*
4974 * Request userauth protocol, and await a response to it.
4975 */
ff3187f6 4976 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4977 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
4978 ssh2_pkt_send(ssh, s->pktout);
4979 crWaitUntilV(pktin);
4980 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 4981 bombout(("Server refused user authentication protocol"));
7ffdbc1a 4982 crStopV;
8d5de777 4983 }
7cca0d81 4984
4985 /*
1408a877 4986 * We repeat this whole loop, including the username prompt,
4987 * until we manage a successful authentication. If the user
51470298 4988 * types the wrong _password_, they can be sent back to the
4989 * beginning to try another username, if this is configured on.
4990 * (If they specify a username in the config, they are never
4991 * asked, even if they do give a wrong password.)
1408a877 4992 *
4993 * I think this best serves the needs of
4994 *
4995 * - the people who have no configuration, no keys, and just
4996 * want to try repeated (username,password) pairs until they
4997 * type both correctly
4998 *
4999 * - people who have keys and configuration but occasionally
5000 * need to fall back to passwords
5001 *
5002 * - people with a key held in Pageant, who might not have
5003 * logged in to a particular machine before; so they want to
5004 * type a username, and then _either_ their key will be
5005 * accepted, _or_ they will type a password. If they mistype
5006 * the username they will want to be able to get back and
5007 * retype it!
7cca0d81 5008 */
51470298 5009 s->username[0] = '\0';
5010 s->got_username = FALSE;
1408a877 5011 do {
1408a877 5012 /*
5013 * Get a username.
5014 */
86916870 5015 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 5016 /*
5017 * We got a username last time round this loop, and
5018 * with change_username turned off we don't try to get
5019 * it again.
5020 */
aa09f7d0 5021 } else if (!*ssh->cfg.username) {
c0a81592 5022 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 5023 if (!ssh_get_line("login as: ",
51470298 5024 s->username, sizeof(s->username), FALSE)) {
32874aea 5025 /*
5026 * get_line failed to get a username.
5027 * Terminate.
5028 */
5029 logevent("No username provided. Abandoning session.");
3bb2f322 5030 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5031 crStopV;
32874aea 5032 }
5033 } else {
51470298 5034 int ret; /* need not be saved across crReturn */
5035 c_write_str(ssh, "login as: ");
5036 ssh->send_ok = 1;
5037 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 5038 do {
ff3187f6 5039 crWaitUntilV(!pktin);
51470298 5040 ret = process_userpass_input(ssh, in, inlen);
0405e71f 5041 } while (ret == 0);
5042 if (ret < 0)
5043 cleanup_exit(0);
4ca0c9d1 5044 c_write_str(ssh, "\r\n");
32874aea 5045 }
51470298 5046 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 5047 } else {
57356d63 5048 char *stuff;
86916870 5049 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 5050 s->username[sizeof(s->username)-1] = '\0';
65a22376 5051 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 5052 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 5053 c_write_str(ssh, stuff);
57356d63 5054 sfree(stuff);
7cca0d81 5055 }
5056 }
51470298 5057 s->got_username = TRUE;
7cca0d81 5058
65a22376 5059 /*
1408a877 5060 * Send an authentication request using method "none": (a)
5061 * just in case it succeeds, and (b) so that we know what
5062 * authentication methods we can usefully try next.
65a22376 5063 */
51470298 5064 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5065
ff3187f6 5066 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5067 ssh2_pkt_addstring(s->pktout, s->username);
5068 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
5069 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5070 ssh2_pkt_send(ssh, s->pktout);
51470298 5071 s->type = AUTH_TYPE_NONE;
5072 s->gotit = FALSE;
5073 s->we_are_in = FALSE;
5074
5075 s->tried_pubkey_config = FALSE;
5076 s->tried_agent = FALSE;
5077 s->tried_keyb_inter = FALSE;
5078 s->kbd_inter_running = FALSE;
86916870 5079 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 5080 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 5081 int keytype;
6c6d9ed9 5082 logeventf(ssh, "Reading private key file \"%.150s\"",
5083 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 5084 keytype = key_type(&ssh->cfg.keyfile);
51470298 5085 if (keytype == SSH_KEYTYPE_SSH2) {
5086 s->publickey_blob =
9a30e26b 5087 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 5088 &s->publickey_bloblen, NULL);
51470298 5089 } else {
57356d63 5090 char *msgbuf;
c2ad7d0d 5091 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 5092 key_type_to_str(keytype));
57356d63 5093 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 5094 " (%s)\r\n",
5095 filename_to_str(&ssh->cfg.keyfile),
57356d63 5096 key_type_to_str(keytype));
51470298 5097 c_write_str(ssh, msgbuf);
57356d63 5098 sfree(msgbuf);
51470298 5099 s->publickey_blob = NULL;
231ee168 5100 }
396778f1 5101 } else
51470298 5102 s->publickey_blob = NULL;
65a22376 5103
1408a877 5104 while (1) {
5105 /*
5106 * Wait for the result of the last authentication request.
5107 */
51470298 5108 if (!s->gotit)
ff3187f6 5109 crWaitUntilV(pktin);
5110 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 5111 char *banner;
5112 int size;
5113 /*
5114 * Don't show the banner if we're operating in
5115 * non-verbose non-interactive mode. (It's probably
5116 * a script, which means nobody will read the
5117 * banner _anyway_, and moreover the printing of
5118 * the banner will screw up processing on the
5119 * output of (say) plink.)
5120 */
5121 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 5122 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 5123 if (banner)
51470298 5124 c_write_untrusted(ssh, banner, size);
32874aea 5125 }
ff3187f6 5126 crWaitUntilV(pktin);
1408a877 5127 }
ff3187f6 5128 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 5129 logevent("Access granted");
51470298 5130 s->we_are_in = TRUE;
1408a877 5131 break;
5132 }
65a22376 5133
51470298 5134 if (s->kbd_inter_running &&
ff3187f6 5135 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 5136 /*
45068b27 5137 * This is either a further set-of-prompts packet
5138 * in keyboard-interactive authentication, or it's
5139 * the same one and we came back here with `gotit'
5140 * set. In the former case, we must reset the
5141 * curr_prompt variable.
b3186d64 5142 */
51470298 5143 if (!s->gotit)
5144 s->curr_prompt = 0;
ff3187f6 5145 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 5146 bombout(("Strange packet received during authentication: type %d",
ff3187f6 5147 pktin->type));
7ffdbc1a 5148 crStopV;
65a22376 5149 }
5150
51470298 5151 s->gotit = FALSE;
65a22376 5152
1408a877 5153 /*
5154 * OK, we're now sitting on a USERAUTH_FAILURE message, so
5155 * we can look at the string in it and know what we can
5156 * helpfully try next.
5157 */
ff3187f6 5158 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 5159 char *methods;
5160 int methlen;
ff3187f6 5161 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 5162 s->kbd_inter_running = FALSE;
ff3187f6 5163 if (!ssh2_pkt_getbool(pktin)) {
1408a877 5164 /*
5165 * We have received an unequivocal Access
5166 * Denied. This can translate to a variety of
5167 * messages:
5168 *
5169 * - if we'd just tried "none" authentication,
5170 * it's not worth printing anything at all
5171 *
5172 * - if we'd just tried a public key _offer_,
5173 * the message should be "Server refused our
5174 * key" (or no message at all if the key
5175 * came from Pageant)
5176 *
5177 * - if we'd just tried anything else, the
5178 * message really should be "Access denied".
5179 *
5180 * Additionally, if we'd just tried password
5181 * authentication, we should break out of this
5182 * whole loop so as to go back to the username
91f57d1f 5183 * prompt (iff we're configured to allow
5184 * username change attempts).
1408a877 5185 */
51470298 5186 if (s->type == AUTH_TYPE_NONE) {
1408a877 5187 /* do nothing */
51470298 5188 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5189 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5190 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5191 c_write_str(ssh, "Server refused our key\r\n");
1408a877 5192 logevent("Server refused public key");
51470298 5193 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 5194 /* server declined keyboard-interactive; ignore */
1408a877 5195 } else {
51470298 5196 c_write_str(ssh, "Access denied\r\n");
1408a877 5197 logevent("Access denied");
91f57d1f 5198 if (s->type == AUTH_TYPE_PASSWORD &&
5199 ssh->cfg.change_username) {
6c9dce7c 5200 /* XXX perhaps we should allow
5201 * keyboard-interactive to do this too? */
51470298 5202 s->we_are_in = FALSE;
1408a877 5203 break;
5204 }
5205 }
5206 } else {
51470298 5207 c_write_str(ssh, "Further authentication required\r\n");
1408a877 5208 logevent("Further authentication required");
5209 }
65a22376 5210
51470298 5211 s->can_pubkey =
32874aea 5212 in_commasep_string("publickey", methods, methlen);
51470298 5213 s->can_passwd =
32874aea 5214 in_commasep_string("password", methods, methlen);
86916870 5215 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 5216 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 5217 }
65a22376 5218
51470298 5219 s->method = 0;
5220 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 5221 s->need_pw = FALSE;
65a22376 5222
0405e71f 5223 /*
5224 * Most password/passphrase prompts will be
5225 * non-echoing, so we set this to 0 by default.
5226 * Exception is that some keyboard-interactive prompts
5227 * can be echoing, in which case we'll set this to 1.
5228 */
51470298 5229 s->echo = 0;
0405e71f 5230
51470298 5231 if (!s->method && s->can_pubkey &&
5232 agent_exists() && !s->tried_agent) {
1983e559 5233 /*
5234 * Attempt public-key authentication using Pageant.
5235 */
1983e559 5236 void *r;
51470298 5237 s->authed = FALSE;
1983e559 5238
51470298 5239 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5240 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 5241
51470298 5242 s->tried_agent = TRUE;
1983e559 5243
5244 logevent("Pageant is running. Requesting keys.");
5245
5246 /* Request the keys held by the agent. */
51470298 5247 PUT_32BIT(s->request, 1);
5248 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 5249 if (!agent_query(s->request, 5, &r, &s->responselen,
5250 ssh_agent_callback, ssh)) {
5251 do {
5252 crReturnV;
ff3187f6 5253 if (pktin) {
839f10db 5254 bombout(("Unexpected data from server while"
5255 " waiting for agent response"));
5256 crStopV;
5257 }
ff3187f6 5258 } while (pktin || inlen > 0);
839f10db 5259 r = ssh->agent_response;
5260 s->responselen = ssh->agent_response_len;
5261 }
51470298 5262 s->response = (unsigned char *) r;
5263 if (s->response && s->responselen >= 5 &&
5264 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5265 s->p = s->response + 5;
5266 s->nkeys = GET_32BIT(s->p);
5267 s->p += 4;
32874aea 5268 {
5269 char buf[64];
51470298 5270 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 5271 logevent(buf);
5272 }
51470298 5273 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 5274 void *vret;
1983e559 5275
32874aea 5276 {
5277 char buf[64];
51470298 5278 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 5279 logevent(buf);
5280 }
51470298 5281 s->pklen = GET_32BIT(s->p);
5282 s->p += 4;
5283 if (s->publickey_blob &&
5284 s->pklen == s->publickey_bloblen &&
5285 !memcmp(s->p, s->publickey_blob,
5286 s->publickey_bloblen)) {
396778f1 5287 logevent("This key matches configured key file");
51470298 5288 s->tried_pubkey_config = 1;
396778f1 5289 }
d8baa528 5290 s->pkblob = (char *)s->p;
51470298 5291 s->p += s->pklen;
5292 s->alglen = GET_32BIT(s->pkblob);
5293 s->alg = s->pkblob + 4;
5294 s->commentlen = GET_32BIT(s->p);
5295 s->p += 4;
d8baa528 5296 s->commentp = (char *)s->p;
51470298 5297 s->p += s->commentlen;
ff3187f6 5298 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5299 ssh2_pkt_addstring(s->pktout, s->username);
5300 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5301 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5302 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
5303 ssh2_pkt_addstring_start(s->pktout);
5304 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5305 ssh2_pkt_addstring_start(s->pktout);
5306 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5307 ssh2_pkt_send(ssh, s->pktout);
5308
5309 crWaitUntilV(pktin);
5310 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 5311 logevent("Key refused");
5312 continue;
5313 }
5314
32874aea 5315 if (flags & FLAG_VERBOSE) {
51470298 5316 c_write_str(ssh, "Authenticating with "
5317 "public key \"");
5318 c_write(ssh, s->commentp, s->commentlen);
5319 c_write_str(ssh, "\" from agent\r\n");
32874aea 5320 }
1983e559 5321
5322 /*
5323 * Server is willing to accept the key.
5324 * Construct a SIGN_REQUEST.
5325 */
ff3187f6 5326 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5327 ssh2_pkt_addstring(s->pktout, s->username);
5328 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5329 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5330 ssh2_pkt_addbool(s->pktout, TRUE);
5331 ssh2_pkt_addstring_start(s->pktout);
5332 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5333 ssh2_pkt_addstring_start(s->pktout);
5334 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5335
5336 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 5337 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5338 s->siglen -= 4;
51470298 5339 s->len = 1; /* message type */
5340 s->len += 4 + s->pklen; /* key blob */
5341 s->len += 4 + s->siglen; /* data to sign */
5342 s->len += 4; /* flags */
3d88e64d 5343 s->agentreq = snewn(4 + s->len, char);
51470298 5344 PUT_32BIT(s->agentreq, s->len);
5345 s->q = s->agentreq + 4;
5346 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5347 PUT_32BIT(s->q, s->pklen);
5348 s->q += 4;
5349 memcpy(s->q, s->pkblob, s->pklen);
5350 s->q += s->pklen;
5351 PUT_32BIT(s->q, s->siglen);
5352 s->q += 4;
1983e559 5353 /* Now the data to be signed... */
dda87a28 5354 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5355 PUT_32BIT(s->q, 20);
5356 s->q += 4;
5357 }
51470298 5358 memcpy(s->q, ssh->v2_session_id, 20);
5359 s->q += 20;
ff3187f6 5360 memcpy(s->q, s->pktout->data + 5,
5361 s->pktout->length - 5);
5362 s->q += s->pktout->length - 5;
1983e559 5363 /* And finally the (zero) flags word. */
51470298 5364 PUT_32BIT(s->q, 0);
839f10db 5365 if (!agent_query(s->agentreq, s->len + 4,
5366 &vret, &s->retlen,
5367 ssh_agent_callback, ssh)) {
5368 do {
5369 crReturnV;
ff3187f6 5370 if (pktin) {
839f10db 5371 bombout(("Unexpected data from server"
5372 " while waiting for agent"
5373 " response"));
5374 crStopV;
5375 }
ff3187f6 5376 } while (pktin || inlen > 0);
839f10db 5377 vret = ssh->agent_response;
5378 s->retlen = ssh->agent_response_len;
5379 }
51470298 5380 s->ret = vret;
5381 sfree(s->agentreq);
5382 if (s->ret) {
5383 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 5384 logevent("Sending Pageant's response");
ff3187f6 5385 ssh2_add_sigblob(ssh, s->pktout,
5386 s->pkblob, s->pklen,
51470298 5387 s->ret + 9,
5388 GET_32BIT(s->ret + 5));
ff3187f6 5389 ssh2_pkt_send(ssh, s->pktout);
51470298 5390 s->authed = TRUE;
1983e559 5391 break;
5392 } else {
32874aea 5393 logevent
5394 ("Pageant failed to answer challenge");
51470298 5395 sfree(s->ret);
1983e559 5396 }
5397 }
5398 }
51470298 5399 if (s->authed)
1983e559 5400 continue;
5401 }
29b1d0b3 5402 sfree(s->response);
1983e559 5403 }
5404
51470298 5405 if (!s->method && s->can_pubkey && s->publickey_blob
5406 && !s->tried_pubkey_config) {
1408a877 5407 unsigned char *pub_blob;
5408 char *algorithm, *comment;
5409 int pub_blob_len;
65a22376 5410
51470298 5411 s->tried_pubkey_config = TRUE;
65a22376 5412
51470298 5413 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5414 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 5415
65a22376 5416 /*
1408a877 5417 * Try the public key supplied in the configuration.
5418 *
5419 * First, offer the public blob to see if the server is
5420 * willing to accept it.
65a22376 5421 */
d8baa528 5422 pub_blob =
9a30e26b 5423 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 5424 &algorithm,
222d54dc 5425 &pub_blob_len,
5426 NULL);
1408a877 5427 if (pub_blob) {
ff3187f6 5428 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5429 ssh2_pkt_addstring(s->pktout, s->username);
5430 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5431 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5432 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
5433 ssh2_pkt_addstring(s->pktout, algorithm);
5434 ssh2_pkt_addstring_start(s->pktout);
5435 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 5436 pub_blob_len);
ff3187f6 5437 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 5438 logevent("Offered public key");
1408a877 5439
ff3187f6 5440 crWaitUntilV(pktin);
5441 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 5442 s->gotit = TRUE;
5443 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 5444 continue; /* key refused; give up on it */
1408a877 5445 }
65a22376 5446
1408a877 5447 logevent("Offer of public key accepted");
65a22376 5448 /*
1408a877 5449 * Actually attempt a serious authentication using
5450 * the key.
65a22376 5451 */
9a30e26b 5452 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 5453 sprintf(s->pwprompt,
32874aea 5454 "Passphrase for key \"%.100s\": ",
5455 comment);
51470298 5456 s->need_pw = TRUE;
1408a877 5457 } else {
51470298 5458 s->need_pw = FALSE;
1408a877 5459 }
4e520718 5460 if (flags & FLAG_VERBOSE) {
5461 c_write_str(ssh, "Authenticating with public key \"");
5462 c_write_str(ssh, comment);
5463 c_write_str(ssh, "\"\r\n");
5464 }
51470298 5465 s->method = AUTH_PUBLICKEY_FILE;
65a22376 5466 }
1408a877 5467 }
5468
51470298 5469 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
5470 s->method = AUTH_KEYBOARD_INTERACTIVE;
5471 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5472 s->tried_keyb_inter = TRUE;
af659722 5473
51470298 5474 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5475 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 5476
ff3187f6 5477 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5478 ssh2_pkt_addstring(s->pktout, s->username);
5479 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5480 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
5481 ssh2_pkt_addstring(s->pktout, ""); /* lang */
5482 ssh2_pkt_addstring(s->pktout, "");
5483 ssh2_pkt_send(ssh, s->pktout);
5484
5485 crWaitUntilV(pktin);
5486 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
5487 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 5488 s->gotit = TRUE;
af659722 5489 logevent("Keyboard-interactive authentication refused");
51470298 5490 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 5491 continue;
5492 }
5493
51470298 5494 s->kbd_inter_running = TRUE;
5495 s->curr_prompt = 0;
af659722 5496 }
5497
51470298 5498 if (s->kbd_inter_running) {
5499 s->method = AUTH_KEYBOARD_INTERACTIVE;
5500 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5501 s->tried_keyb_inter = TRUE;
af659722 5502
51470298 5503 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5504 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 5505
51470298 5506 if (s->curr_prompt == 0) {
45068b27 5507 /*
5508 * We've got a fresh USERAUTH_INFO_REQUEST.
5509 * Display header data, and start going through
5510 * the prompts.
5511 */
5512 char *name, *inst, *lang;
5513 int name_len, inst_len, lang_len;
5514
ff3187f6 5515 ssh_pkt_getstring(pktin, &name, &name_len);
5516 ssh_pkt_getstring(pktin, &inst, &inst_len);
5517 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 5518 if (name_len > 0) {
51470298 5519 c_write_untrusted(ssh, name, name_len);
5520 c_write_str(ssh, "\r\n");
45068b27 5521 }
5522 if (inst_len > 0) {
51470298 5523 c_write_untrusted(ssh, inst, inst_len);
5524 c_write_str(ssh, "\r\n");
45068b27 5525 }
ff3187f6 5526 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 5527 }
af659722 5528
45068b27 5529 /*
5530 * If there are prompts remaining in the packet,
5531 * display one and get a response.
5532 */
51470298 5533 if (s->curr_prompt < s->num_prompts) {
45068b27 5534 char *prompt;
5535 int prompt_len;
af659722 5536
ff3187f6 5537 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 5538 if (prompt_len > 0) {
85fdbe25 5539 static const char trunc[] = "<prompt truncated>: ";
5540 static const int prlen = sizeof(s->pwprompt) -
5541 lenof(trunc);
5542 if (prompt_len > prlen) {
5543 memcpy(s->pwprompt, prompt, prlen);
5544 strcpy(s->pwprompt + prlen, trunc);
5545 } else {
5546 memcpy(s->pwprompt, prompt, prompt_len);
5547 s->pwprompt[prompt_len] = '\0';
5548 }
45068b27 5549 } else {
51470298 5550 strcpy(s->pwprompt,
45068b27 5551 "<server failed to send prompt>: ");
5552 }
ff3187f6 5553 s->echo = ssh2_pkt_getbool(pktin);
51470298 5554 s->need_pw = TRUE;
45068b27 5555 } else
51470298 5556 s->need_pw = FALSE;
af659722 5557 }
5558
51470298 5559 if (!s->method && s->can_passwd) {
5560 s->method = AUTH_PASSWORD;
5561 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5562 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5563 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5564 ssh->savedhost);
5565 s->need_pw = TRUE;
1408a877 5566 }
5567
51470298 5568 if (s->need_pw) {
fa17a66e 5569 if (ssh_get_line) {
51470298 5570 if (!ssh_get_line(s->pwprompt, s->password,
5571 sizeof(s->password), TRUE)) {
1408a877 5572 /*
fa17a66e 5573 * get_line failed to get a password (for
5574 * example because one was supplied on the
5575 * command line which has already failed to
5576 * work). Terminate.
1408a877 5577 */
ff3187f6 5578 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5579 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
5580 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 5581 " to try");
ff3187f6 5582 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 5583 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 5584 logevent("Unable to authenticate");
a8327734 5585 connection_fatal(ssh->frontend,
5586 "Unable to authenticate");
3bb2f322 5587 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5588 crStopV;
1408a877 5589 }
5590 } else {
51470298 5591 int ret; /* need not be saved across crReturn */
5592 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5593 ssh->send_ok = 1;
1408a877 5594
51470298 5595 setup_userpass_input(ssh, s->password,
5596 sizeof(s->password), s->echo);
0405e71f 5597 do {
ff3187f6 5598 crWaitUntilV(!pktin);
51470298 5599 ret = process_userpass_input(ssh, in, inlen);
0405e71f 5600 } while (ret == 0);
5601 if (ret < 0)
5602 cleanup_exit(0);
51470298 5603 c_write_str(ssh, "\r\n");
65a22376 5604 }
65a22376 5605 }
65a22376 5606
51470298 5607 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 5608 /*
5609 * We have our passphrase. Now try the actual authentication.
5610 */
5611 struct ssh2_userkey *key;
222d54dc 5612 const char *error = NULL;
65a22376 5613
222d54dc 5614 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5615 &error);
1408a877 5616 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5617 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 5618 c_write_str(ssh, "Wrong passphrase\r\n");
5619 s->tried_pubkey_config = FALSE;
1408a877 5620 } else {
222d54dc 5621 c_write_str(ssh, "Unable to load private key (");
5622 c_write_str(ssh, error);
5623 c_write_str(ssh, ")\r\n");
51470298 5624 s->tried_pubkey_config = TRUE;
1408a877 5625 }
5626 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 5627 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5628 ssh2_pkt_addstring(s->pktout, s->username);
5629 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5630 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5631 ssh2_pkt_send(ssh, s->pktout);
51470298 5632 s->type = AUTH_TYPE_NONE;
1408a877 5633 } else {
1dd353b5 5634 unsigned char *pkblob, *sigblob, *sigdata;
5635 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 5636 int p;
65a22376 5637
1408a877 5638 /*
5639 * We have loaded the private key and the server
5640 * has announced that it's willing to accept it.
5641 * Hallelujah. Generate a signature and send it.
5642 */
ff3187f6 5643 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5644 ssh2_pkt_addstring(s->pktout, s->username);
5645 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5646 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5647 ssh2_pkt_addbool(s->pktout, TRUE);
5648 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 5649 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 5650 ssh2_pkt_addstring_start(s->pktout);
5651 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 5652
5653 /*
5654 * The data to be signed is:
5655 *
5656 * string session-id
5657 *
5658 * followed by everything so far placed in the
5659 * outgoing packet.
5660 */
ff3187f6 5661 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 5662 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5663 sigdata_len -= 4;
92d60585 5664 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 5665 p = 0;
5666 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5667 PUT_32BIT(sigdata+p, 20);
5668 p += 4;
5669 }
5670 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 5671 memcpy(sigdata+p, s->pktout->data + 5,
5672 s->pktout->length - 5);
5673 p += s->pktout->length - 5;
dda87a28 5674 assert(p == sigdata_len);
d8baa528 5675 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 5676 sigdata_len, &sigblob_len);
ff3187f6 5677 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 5678 sigblob, sigblob_len);
5679 sfree(pkblob);
5680 sfree(sigblob);
1408a877 5681 sfree(sigdata);
5682
ff3187f6 5683 ssh2_pkt_send(ssh, s->pktout);
51470298 5684 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 5685 key->alg->freekey(key->data);
1408a877 5686 }
51470298 5687 } else if (s->method == AUTH_PASSWORD) {
65a22376 5688 /*
1408a877 5689 * We send the password packet lumped tightly together with
5690 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5691 * string long enough to make the total length of the two
5692 * packets constant. This should ensure that a passive
5693 * listener doing traffic analyis can't work out the length
5694 * of the password.
5695 *
5696 * For this to work, we need an assumption about the
5697 * maximum length of the password packet. I think 256 is
5698 * pretty conservative. Anyone using a password longer than
5699 * that probably doesn't have much to worry about from
5700 * people who find out how long their password is!
65a22376 5701 */
ff3187f6 5702 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5703 ssh2_pkt_addstring(s->pktout, s->username);
5704 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5705 ssh2_pkt_addstring(s->pktout, "password");
5706 ssh2_pkt_addbool(s->pktout, FALSE);
5707 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
5708 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 5709 memset(s->password, 0, sizeof(s->password));
ff3187f6 5710 end_log_omission(ssh, s->pktout);
5711 ssh2_pkt_defer(ssh, s->pktout);
65a22376 5712 /*
1408a877 5713 * We'll include a string that's an exact multiple of the
5714 * cipher block size. If the cipher is NULL for some
5715 * reason, we don't do this trick at all because we gain
5716 * nothing by it.
65a22376 5717 */
51470298 5718 if (ssh->cscipher) {
32874aea 5719 int stringlen, i;
5720
51470298 5721 stringlen = (256 - ssh->deferred_len);
5722 stringlen += ssh->cscipher->blksize - 1;
5723 stringlen -= (stringlen % ssh->cscipher->blksize);
5724 if (ssh->cscomp) {
32874aea 5725 /*
5726 * Temporarily disable actual compression,
5727 * so we can guarantee to get this string
5728 * exactly the length we want it. The
5729 * compression-disabling routine should
5730 * return an integer indicating how many
5731 * bytes we should adjust our string length
5732 * by.
5733 */
5366aed8 5734 stringlen -=
5735 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 5736 }
ff3187f6 5737 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
5738 ssh2_pkt_addstring_start(s->pktout);
6e9e9520 5739 for (i = 0; i < stringlen; i++) {
32874aea 5740 char c = (char) random_byte();
ff3187f6 5741 ssh2_pkt_addstring_data(s->pktout, &c, 1);
65a22376 5742 }
ff3187f6 5743 ssh2_pkt_defer(ssh, s->pktout);
65a22376 5744 }
51470298 5745 ssh_pkt_defersend(ssh);
0d43337a 5746 logevent("Sent password");
51470298 5747 s->type = AUTH_TYPE_PASSWORD;
5748 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5749 if (s->curr_prompt == 0) {
ff3187f6 5750 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
5751 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 5752 }
51470298 5753 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 5754 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
5755 ssh2_pkt_addstring(s->pktout, s->password);
51470298 5756 memset(s->password, 0, sizeof(s->password));
ff3187f6 5757 end_log_omission(ssh, s->pktout);
51470298 5758 s->curr_prompt++;
45068b27 5759 }
51470298 5760 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 5761 ssh2_pkt_send(ssh, s->pktout);
45068b27 5762 } else {
5763 /*
5764 * If there are prompts remaining, we set
5765 * `gotit' so that we won't attempt to get
5766 * another packet. Then we go back round the
5767 * loop and will end up retrieving another
5768 * prompt out of the existing packet. Funky or
5769 * what?
5770 */
51470298 5771 s->gotit = TRUE;
45068b27 5772 }
51470298 5773 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 5774 } else {
51470298 5775 c_write_str(ssh, "No supported authentication methods"
5776 " left to try!\r\n");
5777 logevent("No supported authentications offered."
5778 " Disconnecting");
ff3187f6 5779 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5780 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5781 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 5782 " methods available");
ff3187f6 5783 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 5784 ssh2_pkt_send_noqueue(ssh, s->pktout);
3bb2f322 5785 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5786 crStopV;
65a22376 5787 }
65a22376 5788 }
51470298 5789 } while (!s->we_are_in);
7cca0d81 5790
5791 /*
5792 * Now we're authenticated for the connection protocol. The
5793 * connection protocol will automatically have started at this
5794 * point; there's no need to send SERVICE_REQUEST.
5795 */
5796
0ed48730 5797 ssh->channels = newtree234(ssh_channelcmp);
5798
7cca0d81 5799 /*
b09eaa88 5800 * Set up handlers for some connection protocol messages, so we
5801 * don't have to handle them repeatedly in this coroutine.
5802 */
5803 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
5804 ssh2_msg_channel_window_adjust;
5805
5806 /*
0ed48730 5807 * Create the main session channel.
7cca0d81 5808 */
0ed48730 5809 if (!ssh->cfg.ssh_no_shell) {
5810 ssh->mainchan = snew(struct ssh_channel);
5811 ssh->mainchan->ssh = ssh;
5812 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 5813 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5814 ssh2_pkt_addstring(s->pktout, "session");
5815 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 5816 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 5817 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
5818 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
5819 ssh2_pkt_send(ssh, s->pktout);
5820 crWaitUntilV(pktin);
5821 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 5822 bombout(("Server refused to open a session"));
5823 crStopV;
5824 /* FIXME: error data comes back in FAILURE packet */
5825 }
ff3187f6 5826 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 5827 bombout(("Server's channel confirmation cited wrong channel"));
5828 crStopV;
5829 }
ff3187f6 5830 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 5831 ssh->mainchan->type = CHAN_MAINSESSION;
5832 ssh->mainchan->closes = 0;
ff3187f6 5833 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5834 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 5835 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5836 add234(ssh->channels, ssh->mainchan);
62638676 5837 update_specials_menu(ssh->frontend);
0ed48730 5838 logevent("Opened channel for session");
5839 } else
5840 ssh->mainchan = NULL;
7cca0d81 5841
5842 /*
783415f8 5843 * Potentially enable X11 forwarding.
5844 */
0ed48730 5845 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 5846 char proto[20], data[64];
5847 logevent("Requesting X11 forwarding");
302121de 5848 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 5849 data, sizeof(data), ssh->cfg.x11_auth);
5850 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 5851 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5852 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
5853 ssh2_pkt_addstring(s->pktout, "x11-req");
5854 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
5855 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
5856 ssh2_pkt_addstring(s->pktout, proto);
5857 ssh2_pkt_addstring(s->pktout, data);
5858 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
5859 ssh2_pkt_send(ssh, s->pktout);
32874aea 5860
b09eaa88 5861 crWaitUntilV(pktin);
32874aea 5862
ff3187f6 5863 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
5864 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5865 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 5866 " packet type %d", pktin->type));
7ffdbc1a 5867 crStopV;
32874aea 5868 }
5869 logevent("X11 forwarding refused");
5870 } else {
5871 logevent("X11 forwarding enabled");
51470298 5872 ssh->X11_fwd_enabled = TRUE;
32874aea 5873 }
783415f8 5874 }
5875
5876 /*
bc240b21 5877 * Enable port forwardings.
5878 */
5879 {
bc240b21 5880 char type;
5881 int n;
a4fc0d74 5882 int sport,dport,sserv,dserv;
6ee9b735 5883 char sports[256], dports[256], saddr[256], host[256];
bc240b21 5884
51470298 5885 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 5886 /* Add port forwardings. */
86916870 5887 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 5888 while (*ssh->portfwd_strptr) {
5889 type = *ssh->portfwd_strptr++;
6ee9b735 5890 saddr[0] = '\0';
bc240b21 5891 n = 0;
6ee9b735 5892 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5893 if (*ssh->portfwd_strptr == ':') {
5894 /*
5895 * We've seen a colon in the middle of the
5896 * source port number. This means that
5897 * everything we've seen until now is the
5898 * source _address_, so we'll move it into
5899 * saddr and start sports from the beginning
5900 * again.
5901 */
5902 ssh->portfwd_strptr++;
5903 sports[n] = '\0';
5904 strcpy(saddr, sports);
5905 n = 0;
5906 }
5907 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5908 }
bc240b21 5909 sports[n] = 0;
820ebe3b 5910 if (type != 'D') {
5911 if (*ssh->portfwd_strptr == '\t')
5912 ssh->portfwd_strptr++;
5913 n = 0;
5914 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5915 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5916 }
5917 host[n] = 0;
5918 if (*ssh->portfwd_strptr == ':')
5919 ssh->portfwd_strptr++;
5920 n = 0;
5921 while (*ssh->portfwd_strptr) {
5922 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5923 }
5924 dports[n] = 0;
51470298 5925 ssh->portfwd_strptr++;
820ebe3b 5926 dport = atoi(dports);
5927 dserv = 0;
5928 if (dport == 0) {
5929 dserv = 1;
5930 dport = net_service_lookup(dports);
5931 if (!dport) {
5932 logeventf(ssh, "Service lookup failed for destination"
5933 " port \"%s\"", dports);
5934 }
a4fc0d74 5935 }
820ebe3b 5936 } else {
5937 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 5938 dport = dserv = -1;
7d5b0f4d 5939 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 5940 }
bc240b21 5941 sport = atoi(sports);
a4fc0d74 5942 sserv = 0;
5943 if (sport == 0) {
5944 sserv = 1;
68a49acb 5945 sport = net_service_lookup(sports);
5946 if (!sport) {
57356d63 5947 logeventf(ssh, "Service lookup failed for source"
5948 " port \"%s\"", sports);
a4fc0d74 5949 }
5950 }
bc240b21 5951 if (sport && dport) {
94ab1ddf 5952 /* Set up a description of the source port. */
49b8f9c4 5953 static char *sportdesc;
5954 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
94ab1ddf 5955 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5956 (int)(*saddr?1:0), ":",
5957 (int)(sserv ? strlen(sports) : 0), sports,
5958 sserv, "(", sport, sserv, ")");
bc240b21 5959 if (type == 'L') {
94ab1ddf 5960 /* Verbose description of the destination port */
5961 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
5962 host,
5963 (int)(dserv ? strlen(dports) : 0), dports,
5964 dserv, "(", dport, dserv, ")");
5965 const char *err = pfd_addforward(host, dport,
5966 *saddr ? saddr : NULL,
5967 sport, ssh, &ssh->cfg);
5968 if (err) {
5969 logeventf(ssh, "Local port %s forward to %s"
5970 " failed: %s", sportdesc, dportdesc, err);
5971 } else {
5972 logeventf(ssh, "Local port %s forwarding to %s",
5973 sportdesc, dportdesc);
5974 }
5975 sfree(dportdesc);
820ebe3b 5976 } else if (type == 'D') {
94ab1ddf 5977 const char *err = pfd_addforward(NULL, -1,
5978 *saddr ? saddr : NULL,
5979 sport, ssh, &ssh->cfg);
5980 if (err) {
5981 logeventf(ssh, "Local port %s SOCKS dynamic forward"
5982 " setup failed: %s", sportdesc, err);
5983 } else {
5984 logeventf(ssh, "Local port %s doing SOCKS"
5985 " dynamic forwarding", sportdesc);
5986 }
bc240b21 5987 } else {
5988 struct ssh_rportfwd *pf;
3d88e64d 5989 pf = snew(struct ssh_rportfwd);
bc240b21 5990 strcpy(pf->dhost, host);
5991 pf->dport = dport;
5992 pf->sport = sport;
51470298 5993 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 5994 logeventf(ssh, "Duplicate remote port forwarding"
5995 " to %s:%d", host, dport);
bc240b21 5996 sfree(pf);
5997 } else {
94ab1ddf 5998 logeventf(ssh, "Requesting remote port %s"
57356d63 5999 " forward to %s:%.*s%.*s%d%.*s",
94ab1ddf 6000 sportdesc,
57356d63 6001 host,
6002 (int)(dserv ? strlen(dports) : 0), dports,
6003 dserv, "(", dport, dserv, ")");
ff3187f6 6004 s->pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
6005 ssh2_pkt_addstring(s->pktout, "tcpip-forward");
6006 ssh2_pkt_addbool(s->pktout, 1);/* want reply */
49b8f9c4 6007 if (*saddr) {
ff3187f6 6008 ssh2_pkt_addstring(s->pktout, saddr);
49b8f9c4 6009 } else if (ssh->cfg.rport_acceptall) {
ff3187f6 6010 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
49b8f9c4 6011 } else {
ff3187f6 6012 ssh2_pkt_addstring(s->pktout, "127.0.0.1");
49b8f9c4 6013 }
ff3187f6 6014 ssh2_pkt_adduint32(s->pktout, sport);
6015 ssh2_pkt_send(ssh, s->pktout);
bc240b21 6016
b09eaa88 6017 crWaitUntilV(pktin);
bc240b21 6018
ff3187f6 6019 if (pktin->type != SSH2_MSG_REQUEST_SUCCESS) {
6020 if (pktin->type != SSH2_MSG_REQUEST_FAILURE) {
6b5cf8b4 6021 bombout(("Unexpected response to port "
c9886e66 6022 "forwarding request: packet type %d",
ff3187f6 6023 pktin->type));
7ffdbc1a 6024 crStopV;
bc240b21 6025 }
6026 logevent("Server refused this port forwarding");
6027 } else {
6028 logevent("Remote port forwarding enabled");
6029 }
6030 }
6031 }
94ab1ddf 6032 sfree(sportdesc);
bc240b21 6033 }
6034 }
6035 }
6036
6037 /*
36c2a3e9 6038 * Potentially enable agent forwarding.
6039 */
0ed48730 6040 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6041 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6042 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6043 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6044 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6045 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6046 ssh2_pkt_send(ssh, s->pktout);
32874aea 6047
b09eaa88 6048 crWaitUntilV(pktin);
32874aea 6049
ff3187f6 6050 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6051 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6052 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6053 " packet type %d", pktin->type));
7ffdbc1a 6054 crStopV;
32874aea 6055 }
6056 logevent("Agent forwarding refused");
6057 } else {
6058 logevent("Agent forwarding enabled");
51470298 6059 ssh->agentfwd_enabled = TRUE;
32874aea 6060 }
36c2a3e9 6061 }
6062
6063 /*
7cca0d81 6064 * Now allocate a pty for the session.
6065 */
0ed48730 6066 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6067 /* Unpick the terminal-speed string. */
6068 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6069 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6070 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6071 /* Build the pty request. */
ff3187f6 6072 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6073 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6074 ssh2_pkt_addstring(s->pktout, "pty-req");
6075 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6076 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6077 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6078 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6079 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6080 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6081 ssh2_pkt_addstring_start(s->pktout);
6082 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6083 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6084 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6085 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6086 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6087 ssh2_pkt_send(ssh, s->pktout);
51470298 6088 ssh->state = SSH_STATE_INTERMED;
32874aea 6089
b09eaa88 6090 crWaitUntilV(pktin);
32874aea 6091
ff3187f6 6092 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6093 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6094 bombout(("Unexpected response to pty request:"
ff3187f6 6095 " packet type %d", pktin->type));
7ffdbc1a 6096 crStopV;
32874aea 6097 }
51470298 6098 c_write_str(ssh, "Server refused to allocate pty\r\n");
6099 ssh->editing = ssh->echoing = 1;
32874aea 6100 } else {
a5dd8467 6101 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 6102 ssh->ospeed, ssh->ispeed);
32874aea 6103 }
0965bee0 6104 } else {
51470298 6105 ssh->editing = ssh->echoing = 1;
7cca0d81 6106 }
6107
6108 /*
73feed4f 6109 * Send environment variables.
6110 *
6111 * Simplest thing here is to send all the requests at once, and
6112 * then wait for a whole bunch of successes or failures.
6113 */
6114 if (ssh->mainchan && *ssh->cfg.environmt) {
6115 char *e = ssh->cfg.environmt;
6116 char *var, *varend, *val;
6117
6118 s->num_env = 0;
6119
6120 while (*e) {
6121 var = e;
6122 while (*e && *e != '\t') e++;
6123 varend = e;
6124 if (*e == '\t') e++;
6125 val = e;
6126 while (*e) e++;
6127 e++;
6128
ff3187f6 6129 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6130 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6131 ssh2_pkt_addstring(s->pktout, "env");
6132 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6133 ssh2_pkt_addstring_start(s->pktout);
6134 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6135 ssh2_pkt_addstring(s->pktout, val);
6136 ssh2_pkt_send(ssh, s->pktout);
73feed4f 6137
6138 s->num_env++;
6139 }
6140
6141 logeventf(ssh, "Sent %d environment variables", s->num_env);
6142
6143 s->env_ok = 0;
6144 s->env_left = s->num_env;
6145
6146 while (s->env_left > 0) {
b09eaa88 6147 crWaitUntilV(pktin);
73feed4f 6148
ff3187f6 6149 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6150 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 6151 bombout(("Unexpected response to environment request:"
ff3187f6 6152 " packet type %d", pktin->type));
73feed4f 6153 crStopV;
6154 }
6155 } else {
6156 s->env_ok++;
6157 }
6158
6159 s->env_left--;
6160 }
6161
6162 if (s->env_ok == s->num_env) {
6163 logevent("All environment variables successfully set");
6164 } else if (s->env_ok == 0) {
6165 logevent("All environment variables refused");
6166 c_write_str(ssh, "Server refused to set environment variables\r\n");
6167 } else {
6168 logeventf(ssh, "%d environment variables refused",
6169 s->num_env - s->env_ok);
6170 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6171 }
6172 }
6173
6174 /*
fd5e5847 6175 * Start a shell or a remote command. We may have to attempt
6176 * this twice if the config data has provided a second choice
6177 * of command.
7cca0d81 6178 */
0ed48730 6179 if (ssh->mainchan) while (1) {
fd5e5847 6180 int subsys;
6181 char *cmd;
6182
51470298 6183 if (ssh->fallback_cmd) {
86916870 6184 subsys = ssh->cfg.ssh_subsys2;
6185 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 6186 } else {
86916870 6187 subsys = ssh->cfg.ssh_subsys;
6188 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 6189 }
6190
ff3187f6 6191 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6192 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 6193 if (subsys) {
ff3187f6 6194 ssh2_pkt_addstring(s->pktout, "subsystem");
6195 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6196 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6197 } else if (*cmd) {
ff3187f6 6198 ssh2_pkt_addstring(s->pktout, "exec");
6199 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6200 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6201 } else {
ff3187f6 6202 ssh2_pkt_addstring(s->pktout, "shell");
6203 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 6204 }
ff3187f6 6205 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 6206
6207 crWaitUntilV(pktin);
6208
ff3187f6 6209 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6210 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6211 bombout(("Unexpected response to shell/command request:"
ff3187f6 6212 " packet type %d", pktin->type));
7ffdbc1a 6213 crStopV;
fd5e5847 6214 }
6215 /*
6216 * We failed to start the command. If this is the
6217 * fallback command, we really are finished; if it's
6218 * not, and if the fallback command exists, try falling
6219 * back to it before complaining.
6220 */
86916870 6221 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 6222 logevent("Primary command failed; attempting fallback");
51470298 6223 ssh->fallback_cmd = TRUE;
fd5e5847 6224 continue;
6225 }
6b5cf8b4 6226 bombout(("Server refused to start a shell/command"));
7ffdbc1a 6227 crStopV;
fd5e5847 6228 } else {
6229 logevent("Started a shell/command");
32874aea 6230 }
fd5e5847 6231 break;
7cca0d81 6232 }
6233
51470298 6234 ssh->state = SSH_STATE_SESSION;
6235 if (ssh->size_needed)
6236 ssh_size(ssh, ssh->term_width, ssh->term_height);
6237 if (ssh->eof_needed)
6238 ssh_special(ssh, TS_EOF);
6e48c3fe 6239
7cca0d81 6240 /*
6241 * Transfer data!
6242 */
b9d7bcad 6243 if (ssh->ldisc)
6244 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 6245 if (ssh->mainchan)
6246 ssh->send_ok = 1;
7cca0d81 6247 while (1) {
e5574168 6248 crReturnV;
51470298 6249 s->try_send = FALSE;
ff3187f6 6250 if (pktin) {
6251 if (pktin->type == SSH2_MSG_CHANNEL_DATA ||
6252 pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
32874aea 6253 char *data;
6254 int length;
ff3187f6 6255 unsigned i = ssh_pkt_getuint32(pktin);
32874aea 6256 struct ssh_channel *c;
51470298 6257 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 6258 if (!c)
6259 continue; /* nonexistent channel */
ff3187f6 6260 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6261 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
32874aea 6262 continue; /* extended but not stderr */
ff3187f6 6263 ssh_pkt_getstring(pktin, &data, &length);
32874aea 6264 if (data) {
7ffdbc1a 6265 int bufsize = 0;
5471d09a 6266 c->v.v2.locwindow -= length;
32874aea 6267 switch (c->type) {
6268 case CHAN_MAINSESSION:
5471d09a 6269 bufsize =
ff3187f6 6270 from_backend(ssh->frontend, pktin->type ==
5471d09a 6271 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6272 data, length);
32874aea 6273 break;
6274 case CHAN_X11:
5471d09a 6275 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 6276 break;
d74d141c 6277 case CHAN_SOCKDATA:
5471d09a 6278 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 6279 break;
36c2a3e9 6280 case CHAN_AGENT:
32874aea 6281 while (length > 0) {
6282 if (c->u.a.lensofar < 4) {
6283 int l = min(4 - c->u.a.lensofar, length);
6284 memcpy(c->u.a.msglen + c->u.a.lensofar,
6285 data, l);
6286 data += l;
6287 length -= l;
6288 c->u.a.lensofar += l;
6289 }
6290 if (c->u.a.lensofar == 4) {
6291 c->u.a.totallen =
6292 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 6293 c->u.a.message = snewn(c->u.a.totallen,
6294 unsigned char);
32874aea 6295 memcpy(c->u.a.message, c->u.a.msglen, 4);
6296 }
6297 if (c->u.a.lensofar >= 4 && length > 0) {
6298 int l =
6299 min(c->u.a.totallen - c->u.a.lensofar,
6300 length);
6301 memcpy(c->u.a.message + c->u.a.lensofar,
6302 data, l);
6303 data += l;
6304 length -= l;
6305 c->u.a.lensofar += l;
6306 }
6307 if (c->u.a.lensofar == c->u.a.totallen) {
839f10db 6308 void *reply;
32874aea 6309 int replylen;
839f10db 6310 if (agent_query(c->u.a.message,
6311 c->u.a.totallen,
6312 &reply, &replylen,
6313 ssh_agentf_callback, c))
6314 ssh_agentf_callback(c, reply, replylen);
32874aea 6315 sfree(c->u.a.message);
6316 c->u.a.lensofar = 0;
6317 }
6318 }
5471d09a 6319 bufsize = 0;
32874aea 6320 break;
6321 }
6322 /*
5471d09a 6323 * If we are not buffering too much data,
6324 * enlarge the window again at the remote side.
32874aea 6325 */
5471d09a 6326 if (bufsize < OUR_V2_WINSIZE)
6327 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 6328 }
ff3187f6 6329 } else if (pktin->type == SSH2_MSG_CHANNEL_EOF) {
6330 unsigned i = ssh_pkt_getuint32(pktin);
32874aea 6331 struct ssh_channel *c;
6332
51470298 6333 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 6334 if (!c)
6335 continue; /* nonexistent channel */
6336
6337 if (c->type == CHAN_X11) {
6338 /*
6339 * Remote EOF on an X11 channel means we should
6340 * wrap up and close the channel ourselves.
6341 */
6342 x11_close(c->u.x11.s);
6343 sshfwd_close(c);
6344 } else if (c->type == CHAN_AGENT) {
36c2a3e9 6345 sshfwd_close(c);
d74d141c 6346 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 6347 pfd_close(c->u.pfd.s);
6348 sshfwd_close(c);
36c2a3e9 6349 }
ff3187f6 6350 } else if (pktin->type == SSH2_MSG_CHANNEL_CLOSE) {
6351 unsigned i = ssh_pkt_getuint32(pktin);
32874aea 6352 struct ssh_channel *c;
6353
51470298 6354 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 6355 if (!c || ((int)c->remoteid) == -1) {
6b5cf8b4 6356 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
d0d844c1 6357 c ? "half-open" : "nonexistent", i));
7ffdbc1a 6358 crStopV;
d0d844c1 6359 }
32874aea 6360 /* Do pre-close processing on the channel. */
6361 switch (c->type) {
6362 case CHAN_MAINSESSION:
62638676 6363 ssh->mainchan = NULL;
6364 update_specials_menu(ssh->frontend);
6365 break;
32874aea 6366 case CHAN_X11:
92f157bd 6367 if (c->u.x11.s != NULL)
6368 x11_close(c->u.x11.s);
6369 sshfwd_close(c);
32874aea 6370 break;
6371 case CHAN_AGENT:
92f157bd 6372 sshfwd_close(c);
32874aea 6373 break;
d74d141c 6374 case CHAN_SOCKDATA:
92f157bd 6375 if (c->u.pfd.s != NULL)
6376 pfd_close(c->u.pfd.s);
6377 sshfwd_close(c);
bc240b21 6378 break;
32874aea 6379 }
92f157bd 6380 if (c->closes == 0) {
ff3187f6 6381 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6382 ssh2_pkt_adduint32(s->pktout, c->remoteid);
6383 ssh2_pkt_send(ssh, s->pktout);
92f157bd 6384 }
51470298 6385 del234(ssh->channels, c);
5471d09a 6386 bufchain_clear(&c->v.v2.outbuffer);
32874aea 6387 sfree(c);
6388
6389 /*
6390 * See if that was the last channel left open.
0ed48730 6391 * (This is only our termination condition if we're
6392 * not running in -N mode.)
32874aea 6393 */
0ed48730 6394 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
3bb2f322 6395 logevent("All channels closed. Disconnecting");
ca2914d1 6396#if 0
6397 /*
6398 * We used to send SSH_MSG_DISCONNECT here,
6399 * because I'd believed that _every_ conforming
6400 * SSH2 connection had to end with a disconnect
6401 * being sent by at least one side; apparently
6402 * I was wrong and it's perfectly OK to
6403 * unceremoniously slam the connection shut
6404 * when you're done, and indeed OpenSSH feels
6405 * this is more polite than sending a
6406 * DISCONNECT. So now we don't.
6407 */
ff3187f6 6408 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6409 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6410 ssh2_pkt_addstring(s->pktout, "All open channels closed");
6411 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6412 ssh2_pkt_send_noqueue(ssh, s->pktout);
ca2914d1 6413#endif
3bb2f322 6414 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6415 crStopV;
32874aea 6416 }
6417 continue; /* remote sends close; ignore (FIXME) */
ff3187f6 6418 } else if (pktin->type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6419 unsigned i = ssh_pkt_getuint32(pktin);
bc240b21 6420 struct ssh_channel *c;
51470298 6421 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 6422 if (!c)
6423 continue; /* nonexistent channel */
6424 if (c->type != CHAN_SOCKDATA_DORMANT)
6425 continue; /* dunno why they're confirming this */
ff3187f6 6426 c->remoteid = ssh_pkt_getuint32(pktin);
bc240b21 6427 c->type = CHAN_SOCKDATA;
ff3187f6 6428 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6429 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
4ed34d25 6430 if (c->u.pfd.s)
6431 pfd_confirm(c->u.pfd.s);
6432 if (c->closes) {
6433 /*
6434 * We have a pending close on this channel,
6435 * which we decided on before the server acked
6436 * the channel open. So now we know the
6437 * remoteid, we can close it again.
6438 */
ff3187f6 6439 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6440 ssh2_pkt_adduint32(s->pktout, c->remoteid);
6441 ssh2_pkt_send(ssh, s->pktout);
4ed34d25 6442 }
ff3187f6 6443 } else if (pktin->type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
e595953d 6444 static const char *const reasons[] = {
6445 "<unknown reason code>",
6446 "Administratively prohibited",
6447 "Connect failed",
6448 "Unknown channel type",
6449 "Resource shortage",
6450 };
ff3187f6 6451 unsigned i = ssh_pkt_getuint32(pktin);
e595953d 6452 unsigned reason_code;
6453 char *reason_string;
6454 int reason_length;
6455 char *message;
724cface 6456 struct ssh_channel *c;
51470298 6457 c = find234(ssh->channels, &i, ssh_channelfind);
724cface 6458 if (!c)
6459 continue; /* nonexistent channel */
6460 if (c->type != CHAN_SOCKDATA_DORMANT)
6461 continue; /* dunno why they're failing this */
6462
ff3187f6 6463 reason_code = ssh_pkt_getuint32(pktin);
e595953d 6464 if (reason_code >= lenof(reasons))
6465 reason_code = 0; /* ensure reasons[reason_code] in range */
ff3187f6 6466 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
e595953d 6467 message = dupprintf("Forwarded connection refused by"
6468 " server: %s [%.*s]", reasons[reason_code],
6469 reason_length, reason_string);
6470 logevent(message);
6471 sfree(message);
724cface 6472
6473 pfd_close(c->u.pfd.s);
6474
51470298 6475 del234(ssh->channels, c);
724cface 6476 sfree(c);
ff3187f6 6477 } else if (pktin->type == SSH2_MSG_CHANNEL_REQUEST) {
ebb0a590 6478 unsigned localid;
6479 char *type;
6480 int typelen, want_reply;
2b7540a7 6481 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
ebb0a590 6482 struct ssh_channel *c;
6483
ff3187f6 6484 localid = ssh_pkt_getuint32(pktin);
6485 ssh_pkt_getstring(pktin, &type, &typelen);
6486 want_reply = ssh2_pkt_getbool(pktin);
ebb0a590 6487
6488 /*
6489 * First, check that the channel exists. Otherwise,
6490 * we can instantly disconnect with a rude message.
6491 */
51470298 6492 c = find234(ssh->channels, &localid, ssh_channelfind);
ebb0a590 6493 if (!c) {
6494 char buf[80];
6495 sprintf(buf, "Received channel request for nonexistent"
6496 " channel %d", localid);
6497 logevent(buf);
ff3187f6 6498 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6499 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6500 ssh2_pkt_addstring(s->pktout, buf);
6501 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6502 ssh2_pkt_send_noqueue(ssh, s->pktout);
6b5cf8b4 6503 connection_fatal(ssh->frontend, "%s", buf);
3bb2f322 6504 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6505 crStopV;
ebb0a590 6506 }
6507
6508 /*
d8d6c7e5 6509 * Having got the channel number, we now look at
6510 * the request type string to see if it's something
6511 * we recognise.
ebb0a590 6512 */
2b7540a7 6513 if (c == ssh->mainchan) {
6514 /*
6515 * We recognise "exit-status" and "exit-signal" on
6516 * the primary channel.
6517 */
6518 if (typelen == 11 &&
6519 !memcmp(type, "exit-status", 11)) {
6520
ff3187f6 6521 ssh->exitcode = ssh_pkt_getuint32(pktin);
2b7540a7 6522 logeventf(ssh, "Server sent command exit status %d",
6523 ssh->exitcode);
6524 reply = SSH2_MSG_CHANNEL_SUCCESS;
6525
6526 } else if (typelen == 11 &&
6527 !memcmp(type, "exit-signal", 11)) {
6528
6529 int is_plausible = TRUE, is_int = FALSE;
6530 char *fmt_sig = "", *fmt_msg = "";
6531 char *msg;
6532 int msglen = 0, core = FALSE;
6533 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6534 * provide an `int' for the signal, despite its
6535 * having been a `string' in the drafts since at
6536 * least 2001. (Fixed in session.c 1.147.) Try to
6537 * infer which we can safely parse it as. */
6538 {
ff3187f6 6539 unsigned char *p = pktin->body +
6540 pktin->savedpos;
6541 long len = pktin->length - pktin->savedpos;
2b7540a7 6542 unsigned long num = GET_32BIT(p); /* what is it? */
6543 /* If it's 0, it hardly matters; assume string */
6544 if (num == 0) {
6545 is_int = FALSE;
6546 } else {
6547 int maybe_int = FALSE, maybe_str = FALSE;
6548#define CHECK_HYPOTHESIS(offset, result) \
6549 do { \
6550 long q = offset; \
4ec461e2 6551 if (q >= 0 && q+4 <= len) { \
2b7540a7 6552 q = q + 4 + GET_32BIT(p+q); \
4ec461e2 6553 if (q >= 0 && q+4 <= len && \
6554 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
2b7540a7 6555 result = TRUE; \
6556 } \
6557 } while(0)
6558 CHECK_HYPOTHESIS(4+1, maybe_int);
6559 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6560#undef CHECK_HYPOTHESIS
6561 if (maybe_int && !maybe_str)
6562 is_int = TRUE;
6563 else if (!maybe_int && maybe_str)
6564 is_int = FALSE;
6565 else
6566 /* Crikey. Either or neither. Panic. */
6567 is_plausible = FALSE;
6568 }
6569 }
6570 if (is_plausible) {
6571 if (is_int) {
6572 /* Old non-standard OpenSSH. */
ff3187f6 6573 int signum = ssh_pkt_getuint32(pktin);
2b7540a7 6574 fmt_sig = dupprintf(" %d", signum);
6575 } else {
6576 /* As per the drafts. */
6577 char *sig;
6578 int siglen;
ff3187f6 6579 ssh_pkt_getstring(pktin, &sig, &siglen);
2b7540a7 6580 /* Signal name isn't supposed to be blank, but
6581 * let's cope gracefully if it is. */
6582 if (siglen) {
6583 fmt_sig = dupprintf(" \"%.*s\"",
6584 siglen, sig);
6585 }
6586 }
ff3187f6 6587 core = ssh2_pkt_getbool(pktin);
6588 ssh_pkt_getstring(pktin, &msg, &msglen);
2b7540a7 6589 if (msglen) {
6590 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6591 }
6592 /* ignore lang tag */
6593 } /* else don't attempt to parse */
6594 logeventf(ssh, "Server exited on signal%s%s%s",
6595 fmt_sig, core ? " (core dumped)" : "",
6596 fmt_msg);
6597 if (*fmt_sig) sfree(fmt_sig);
6598 if (*fmt_msg) sfree(fmt_msg);
6599 reply = SSH2_MSG_CHANNEL_SUCCESS;
6600
d8d6c7e5 6601 }
6602 } else {
6603 /*
6604 * This is a channel request we don't know
6605 * about, so we now either ignore the request
6606 * or respond with CHANNEL_FAILURE, depending
6607 * on want_reply.
6608 */
2b7540a7 6609 reply = SSH2_MSG_CHANNEL_FAILURE;
6610 }
6611 if (want_reply) {
ff3187f6 6612 s->pktout = ssh2_pkt_init(reply);
6613 ssh2_pkt_adduint32(s->pktout, c->remoteid);
6614 ssh2_pkt_send(ssh, s->pktout);
ebb0a590 6615 }
ff3187f6 6616 } else if (pktin->type == SSH2_MSG_GLOBAL_REQUEST) {
697d4856 6617 char *type;
6618 int typelen, want_reply;
6619
ff3187f6 6620 ssh_pkt_getstring(pktin, &type, &typelen);
6621 want_reply = ssh2_pkt_getbool(pktin);
697d4856 6622
6623 /*
6624 * We currently don't support any global requests
6625 * at all, so we either ignore the request or
6626 * respond with REQUEST_FAILURE, depending on
6627 * want_reply.
6628 */
6629 if (want_reply) {
ff3187f6 6630 s->pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6631 ssh2_pkt_send(ssh, s->pktout);
697d4856 6632 }
ff3187f6 6633 } else if (pktin->type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 6634 char *type;
6635 int typelen;
b3ebaa28 6636 char *peeraddr;
6637 int peeraddrlen;
2e5b14c0 6638 int peerport;
32874aea 6639 char *error = NULL;
6640 struct ssh_channel *c;
bc240b21 6641 unsigned remid, winsize, pktsize;
ff3187f6 6642 ssh_pkt_getstring(pktin, &type, &typelen);
3d88e64d 6643 c = snew(struct ssh_channel);
51470298 6644 c->ssh = ssh;
32874aea 6645
ff3187f6 6646 remid = ssh_pkt_getuint32(pktin);
6647 winsize = ssh_pkt_getuint32(pktin);
6648 pktsize = ssh_pkt_getuint32(pktin);
bc240b21 6649
32874aea 6650 if (typelen == 3 && !memcmp(type, "x11", 3)) {
df85f78b 6651 char *addrstr;
6652
ff3187f6 6653 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
df85f78b 6654 addrstr = snewn(peeraddrlen+1, char);
b3ebaa28 6655 memcpy(addrstr, peeraddr, peeraddrlen);
5a9bf764 6656 addrstr[peeraddrlen] = '\0';
ff3187f6 6657 peerport = ssh_pkt_getuint32(pktin);
b3ebaa28 6658
5a9bf764 6659 logeventf(ssh, "Received X11 connect request from %s:%d",
6660 addrstr, peerport);
6661
51470298 6662 if (!ssh->X11_fwd_enabled)
32874aea 6663 error = "X11 forwarding is not enabled";
86916870 6664 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
2e5b14c0 6665 ssh->x11auth, addrstr, peerport,
e8fa8f62 6666 &ssh->cfg) != NULL) {
32874aea 6667 error = "Unable to open an X11 connection";
6668 } else {
5a9bf764 6669 logevent("Opening X11 forward connection succeeded");
32874aea 6670 c->type = CHAN_X11;
6671 }
b3ebaa28 6672
6673 sfree(addrstr);
bc240b21 6674 } else if (typelen == 15 &&
6675 !memcmp(type, "forwarded-tcpip", 15)) {
6676 struct ssh_rportfwd pf, *realpf;
6677 char *dummy;
6678 int dummylen;
ff3187f6 6679 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6680 pf.sport = ssh_pkt_getuint32(pktin);
6681 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6682 peerport = ssh_pkt_getuint32(pktin);
51470298 6683 realpf = find234(ssh->rportfwds, &pf, NULL);
5a9bf764 6684 logeventf(ssh, "Received remote port %d open request "
6685 "from %s:%d", pf.sport, peeraddr, peerport);
bc240b21 6686 if (realpf == NULL) {
6687 error = "Remote port is not recognised";
6688 } else {
cbe2d68f 6689 const char *e = pfd_newconnect(&c->u.pfd.s,
6690 realpf->dhost,
6691 realpf->dport, c,
6692 &ssh->cfg);
5a9bf764 6693 logeventf(ssh, "Attempting to forward remote port to "
6694 "%s:%d", realpf->dhost, realpf->dport);
bc240b21 6695 if (e != NULL) {
57356d63 6696 logeventf(ssh, "Port open failed: %s", e);
bc240b21 6697 error = "Port open failed";
6698 } else {
6699 logevent("Forwarded port opened successfully");
6700 c->type = CHAN_SOCKDATA;
6701 }
6702 }
32874aea 6703 } else if (typelen == 22 &&
36c2a3e9 6704 !memcmp(type, "auth-agent@openssh.com", 3)) {
51470298 6705 if (!ssh->agentfwd_enabled)
32874aea 6706 error = "Agent forwarding is not enabled";
36c2a3e9 6707 else {
32874aea 6708 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 6709 c->u.a.lensofar = 0;
32874aea 6710 }
6711 } else {
6712 error = "Unsupported channel type requested";
6713 }
6714
bc240b21 6715 c->remoteid = remid;
32874aea 6716 if (error) {
ff3187f6 6717 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6718 ssh2_pkt_adduint32(s->pktout, c->remoteid);
6719 ssh2_pkt_adduint32(s->pktout, SSH2_OPEN_CONNECT_FAILED);
6720 ssh2_pkt_addstring(s->pktout, error);
6721 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6722 ssh2_pkt_send(ssh, s->pktout);
5a9bf764 6723 logeventf(ssh, "Rejected channel open: %s", error);
32874aea 6724 sfree(c);
6725 } else {
51470298 6726 c->localid = alloc_channel_id(ssh);
32874aea 6727 c->closes = 0;
5471d09a 6728 c->v.v2.locwindow = OUR_V2_WINSIZE;
6729 c->v.v2.remwindow = winsize;
6730 c->v.v2.remmaxpkt = pktsize;
6731 bufchain_init(&c->v.v2.outbuffer);
51470298 6732 add234(ssh->channels, c);
ff3187f6 6733 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6734 ssh2_pkt_adduint32(s->pktout, c->remoteid);
6735 ssh2_pkt_adduint32(s->pktout, c->localid);
6736 ssh2_pkt_adduint32(s->pktout, c->v.v2.locwindow);
6737 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6738 ssh2_pkt_send(ssh, s->pktout);
32874aea 6739 }
7cca0d81 6740 } else {
ff3187f6 6741 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 6742 crStopV;
7cca0d81 6743 }
0ed48730 6744 } else if (ssh->mainchan) {
32874aea 6745 /*
6746 * We have spare data. Add it to the channel buffer.
6747 */
d8baa528 6748 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 6749 s->try_send = TRUE;
32874aea 6750 }
51470298 6751 if (s->try_send) {
32874aea 6752 int i;
6753 struct ssh_channel *c;
6754 /*
6755 * Try to send data on all channels if we can.
6756 */
51470298 6757 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 6758 int bufsize;
6759 if (c->closes)
6760 continue; /* don't send on closing channels */
6761 bufsize = ssh2_try_send(c);
5471d09a 6762 if (bufsize == 0) {
6763 switch (c->type) {
6764 case CHAN_MAINSESSION:
6765 /* stdin need not receive an unthrottle
6766 * notification since it will be polled */
6767 break;
6768 case CHAN_X11:
6769 x11_unthrottle(c->u.x11.s);
6770 break;
6771 case CHAN_AGENT:
6772 /* agent sockets are request/response and need no
6773 * buffer management */
6774 break;
6775 case CHAN_SOCKDATA:
6776 pfd_unthrottle(c->u.pfd.s);
6777 break;
6778 }
6779 }
6780 }
7cca0d81 6781 }
e5574168 6782 }
6783
6784 crFinishV;
6785}
6786
6787/*
b09eaa88 6788 * Handlers for SSH2 messages that might arrive at any moment.
6789 */
6790void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
6791{
6792 /* log reason code in disconnect message */
6793 char *buf, *msg;
6794 int nowlen, reason, msglen;
6795
6796 reason = ssh_pkt_getuint32(pktin);
6797 ssh_pkt_getstring(pktin, &msg, &msglen);
6798
6799 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
6800 buf = dupprintf("Received disconnect message (%s)",
6801 ssh2_disconnect_reasons[reason]);
6802 } else {
6803 buf = dupprintf("Received disconnect message (unknown"
6804 " type %d)", reason);
6805 }
6806 logevent(buf);
6807 sfree(buf);
6808 buf = dupprintf("Disconnection message text: %n%.*s",
6809 &nowlen, msglen, msg);
6810 logevent(buf);
6811 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
6812 reason,
6813 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
6814 ssh2_disconnect_reasons[reason] : "unknown",
6815 buf+nowlen));
6816 sfree(buf);
6817}
6818
6819void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
6820{
6821 /* log the debug message */
6822 char *buf, *msg;
6823 int msglen;
6824 int always_display;
6825
6826 /* XXX maybe we should actually take notice of this */
6827 always_display = ssh2_pkt_getbool(pktin);
6828 ssh_pkt_getstring(pktin, &msg, &msglen);
6829
6830 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
6831 logevent(buf);
6832 sfree(buf);
6833}
6834
6835void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
6836{
6837 struct Packet *pktout;
6838 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
6839 ssh2_pkt_adduint32(pktout, pktin->sequence);
6840 /*
6841 * UNIMPLEMENTED messages MUST appear in the same order as the
6842 * messages they respond to. Hence, never queue them.
6843 */
6844 ssh2_pkt_send_noqueue(ssh, pktout);
6845}
6846
6847/*
7cca0d81 6848 * Handle the top-level SSH2 protocol.
6849 */
b09eaa88 6850static void ssh2_protocol_setup(Ssh ssh)
6851{
6852 int i;
6853
6854 /*
6855 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
6856 */
6857 for (i = 0; i < 256; i++)
6858 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
6859
6860 /*
6861 * Any message we actually understand, we set to NULL so that
6862 * the coroutines will get it.
6863 */
6864 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
6865 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
6866 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
6867 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
6868 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
6869 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
6870 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
6871 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
6872 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
6873 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
6874 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
6875 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
6876 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
6877 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
6878 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
6879 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
6880 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
6881 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
6882 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
6883 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
6884 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
6885 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
6886 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
6887 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
6888 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
6889 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
6890 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
6891 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
6892 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
6893 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
6894 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
6895 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
6896 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
6897
6898 /*
6899 * These special message types we install handlers for.
6900 */
6901 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
6902 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
6903 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
6904}
6905
9442dd57 6906static void ssh2_timer(void *ctx, long now)
6907{
6908 Ssh ssh = (Ssh)ctx;
6909
6910 if (!ssh->kex_in_progress &&
6911 now - ssh->next_rekey >= 0) {
6912 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
6913 -1, NULL);
6914 }
6915}
6916
ff3187f6 6917static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
6918 struct Packet *pktin)
7cca0d81 6919{
b09eaa88 6920 if (ssh->state == SSH_STATE_CLOSED)
6921 return;
6922
9442dd57 6923 if (pktin) {
6924 ssh->incoming_data_size += pktin->encrypted_len;
6925 if (!ssh->kex_in_progress &&
6926 ssh->incoming_data_size > MAX_DATA_BEFORE_REKEY)
6927 do_ssh2_transport(ssh, "Initiating key re-exchange "
6928 "(too much data received)", -1, NULL);
6929 }
6930
b09eaa88 6931 if (pktin && ssh->packet_dispatch[pktin->type]) {
6932 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 6933 return;
b09eaa88 6934 }
6935
6936 if (!ssh->protocol_initial_phase_done ||
6937 (pktin && pktin->type >= 20 && pktin->type < 50)) {
6938 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
6939 !ssh->protocol_initial_phase_done) {
6940 ssh->protocol_initial_phase_done = TRUE;
6941 /*
6942 * Allow authconn to initialise itself.
6943 */
6944 do_ssh2_authconn(ssh, NULL, 0, NULL);
6945 }
6946 } else {
6947 do_ssh2_authconn(ssh, in, inlen, pktin);
6948 }
7cca0d81 6949}
6950
6951/*
8df7a775 6952 * Called to set up the connection.
374330e2 6953 *
6954 * Returns an error message, or NULL on success.
374330e2 6955 */
cbe2d68f 6956static const char *ssh_init(void *frontend_handle, void **backend_handle,
6957 Config *cfg,
79bf227b 6958 char *host, int port, char **realhost, int nodelay,
6959 int keepalive)
32874aea 6960{
cbe2d68f 6961 const char *p;
51470298 6962 Ssh ssh;
6963
3d88e64d 6964 ssh = snew(struct ssh_tag);
86916870 6965 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 6966 ssh->version = 0; /* when not ready yet */
51470298 6967 ssh->s = NULL;
6968 ssh->cipher = NULL;
371e569c 6969 ssh->v1_cipher_ctx = NULL;
0183b242 6970 ssh->crcda_ctx = NULL;
51470298 6971 ssh->cscipher = NULL;
371e569c 6972 ssh->cs_cipher_ctx = NULL;
51470298 6973 ssh->sccipher = NULL;
371e569c 6974 ssh->sc_cipher_ctx = NULL;
51470298 6975 ssh->csmac = NULL;
a8327734 6976 ssh->cs_mac_ctx = NULL;
51470298 6977 ssh->scmac = NULL;
e0e1a00d 6978 ssh->sc_mac_ctx = NULL;
51470298 6979 ssh->cscomp = NULL;
5366aed8 6980 ssh->cs_comp_ctx = NULL;
51470298 6981 ssh->sccomp = NULL;
5366aed8 6982 ssh->sc_comp_ctx = NULL;
51470298 6983 ssh->kex = NULL;
389aa499 6984 ssh->kex_ctx = NULL;
51470298 6985 ssh->hostkey = NULL;
6986 ssh->exitcode = -1;
6987 ssh->state = SSH_STATE_PREPACKET;
6988 ssh->size_needed = FALSE;
6989 ssh->eof_needed = FALSE;
b9d7bcad 6990 ssh->ldisc = NULL;
a8327734 6991 ssh->logctx = NULL;
51470298 6992 ssh->deferred_send_data = NULL;
6993 ssh->deferred_len = 0;
6994 ssh->deferred_size = 0;
6995 ssh->fallback_cmd = 0;
6996 ssh->pkt_ctx = 0;
302121de 6997 ssh->x11auth = NULL;
be738459 6998 ssh->v1_compressing = FALSE;
51470298 6999 ssh->v2_outgoing_sequence = 0;
7000 ssh->ssh1_rdpkt_crstate = 0;
7001 ssh->ssh2_rdpkt_crstate = 0;
7002 ssh->do_ssh_init_crstate = 0;
7003 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7004 ssh->do_ssh1_connection_crstate = 0;
51470298 7005 ssh->do_ssh1_login_crstate = 0;
7006 ssh->do_ssh2_transport_crstate = 0;
7007 ssh->do_ssh2_authconn_crstate = 0;
7008 ssh->do_ssh_init_state = NULL;
7009 ssh->do_ssh1_login_state = NULL;
7010 ssh->do_ssh2_transport_state = NULL;
7011 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7012 ssh->mainchan = NULL;
968d2d92 7013 ssh->throttled_all = 0;
7014 ssh->v1_stdout_throttling = 0;
590f6a5f 7015 ssh->queue = NULL;
7016 ssh->queuelen = ssh->queuesize = 0;
7017 ssh->queueing = FALSE;
51470298 7018
7019 *backend_handle = ssh;
32874aea 7020
8f203108 7021#ifdef MSCRYPTOAPI
32874aea 7022 if (crypto_startup() == 0)
8f203108 7023 return "Microsoft high encryption pack not installed!";
7024#endif
374330e2 7025
51470298 7026 ssh->frontend = frontend_handle;
86916870 7027 ssh->term_width = ssh->cfg.width;
7028 ssh->term_height = ssh->cfg.height;
887035a5 7029
fabd1805 7030 ssh->channels = NULL;
7031 ssh->rportfwds = NULL;
7032
51470298 7033 ssh->send_ok = 0;
7034 ssh->editing = 0;
7035 ssh->echoing = 0;
7036 ssh->v1_throttle_count = 0;
7037 ssh->overall_bufsize = 0;
7038 ssh->fallback_cmd = 0;
8df7a775 7039
3648d4c5 7040 ssh->protocol = NULL;
7041
b09eaa88 7042 ssh->protocol_initial_phase_done = FALSE;
7043
39934deb 7044 ssh->pinger = NULL;
7045
9442dd57 7046 ssh->incoming_data_size = ssh->outgoing_data_size =
7047 ssh->deferred_data_size = 0L;
7048 ssh->kex_in_progress = FALSE;
7049
79bf227b 7050 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7051 if (p != NULL)
7052 return p;
374330e2 7053
374330e2 7054 return NULL;
7055}
7056
fabd1805 7057static void ssh_free(void *handle)
7058{
7059 Ssh ssh = (Ssh) handle;
7060 struct ssh_channel *c;
7061 struct ssh_rportfwd *pf;
7062
7063 if (ssh->v1_cipher_ctx)
7064 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7065 if (ssh->cs_cipher_ctx)
7066 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7067 if (ssh->sc_cipher_ctx)
7068 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7069 if (ssh->cs_mac_ctx)
7070 ssh->csmac->free_context(ssh->cs_mac_ctx);
7071 if (ssh->sc_mac_ctx)
7072 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7073 if (ssh->cs_comp_ctx) {
7074 if (ssh->cscomp)
7075 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7076 else
7077 zlib_compress_cleanup(ssh->cs_comp_ctx);
7078 }
7079 if (ssh->sc_comp_ctx) {
7080 if (ssh->sccomp)
7081 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7082 else
7083 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7084 }
fabd1805 7085 if (ssh->kex_ctx)
7086 dh_cleanup(ssh->kex_ctx);
7087 sfree(ssh->savedhost);
7088
590f6a5f 7089 while (ssh->queuelen-- > 0)
7090 ssh_free_packet(ssh->queue[ssh->queuelen]);
7091 sfree(ssh->queue);
7092
fabd1805 7093 if (ssh->channels) {
7094 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7095 switch (c->type) {
7096 case CHAN_X11:
7097 if (c->u.x11.s != NULL)
7098 x11_close(c->u.x11.s);
7099 break;
7100 case CHAN_SOCKDATA:
7101 if (c->u.pfd.s != NULL)
7102 pfd_close(c->u.pfd.s);
7103 break;
7104 }
7105 sfree(c);
7106 }
7107 freetree234(ssh->channels);
7108 }
7109
7110 if (ssh->rportfwds) {
7111 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7112 sfree(pf);
7113 freetree234(ssh->rportfwds);
7114 }
7115 sfree(ssh->deferred_send_data);
7116 if (ssh->x11auth)
7117 x11_free_auth(ssh->x11auth);
7118 sfree(ssh->do_ssh_init_state);
7119 sfree(ssh->do_ssh1_login_state);
7120 sfree(ssh->do_ssh2_transport_state);
7121 sfree(ssh->do_ssh2_authconn_state);
679539d7 7122 if (ssh->crcda_ctx) {
7123 crcda_free_context(ssh->crcda_ctx);
7124 ssh->crcda_ctx = NULL;
7125 }
fabd1805 7126 if (ssh->s)
36f94d1f 7127 ssh_do_close(ssh);
9442dd57 7128 expire_timer_context(ssh);
fabd1805 7129 sfree(ssh);
39934deb 7130 if (ssh->pinger)
7131 pinger_free(ssh->pinger);
fabd1805 7132}
7133
374330e2 7134/*
86916870 7135 * Reconfigure the SSH backend.
7136 *
7137 * Currently, this function does nothing very useful. In future,
7138 * however, we could do some handy things with it. For example, we
7139 * could make the port forwarding configurer active in the Change
7140 * Settings box, and this routine could close down existing
7141 * forwardings and open up new ones in response to changes.
7142 */
7143static void ssh_reconfig(void *handle, Config *cfg)
7144{
7145 Ssh ssh = (Ssh) handle;
39934deb 7146 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
86916870 7147 ssh->cfg = *cfg; /* STRUCTURE COPY */
7148}
7149
7150/*
374330e2 7151 * Called to send data down the Telnet connection.
7152 */
51470298 7153static int ssh_send(void *handle, char *buf, int len)
32874aea 7154{
51470298 7155 Ssh ssh = (Ssh) handle;
7156
7157 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7158 return 0;
374330e2 7159
d8baa528 7160 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7161
51470298 7162 return ssh_sendbuffer(ssh);
5471d09a 7163}
7164
7165/*
7166 * Called to query the current amount of buffered stdin data.
7167 */
51470298 7168static int ssh_sendbuffer(void *handle)
5471d09a 7169{
51470298 7170 Ssh ssh = (Ssh) handle;
5471d09a 7171 int override_value;
7172
51470298 7173 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7174 return 0;
7175
7176 /*
7177 * If the SSH socket itself has backed up, add the total backup
7178 * size on that to any individual buffer on the stdin channel.
7179 */
7180 override_value = 0;
51470298 7181 if (ssh->throttled_all)
7182 override_value = ssh->overall_bufsize;
5471d09a 7183
51470298 7184 if (ssh->version == 1) {
5471d09a 7185 return override_value;
51470298 7186 } else if (ssh->version == 2) {
7187 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7188 return override_value;
7189 else
51470298 7190 return (override_value +
7191 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7192 }
7193
7194 return 0;
374330e2 7195}
7196
7197/*
6e48c3fe 7198 * Called to set the size of the window from SSH's POV.
374330e2 7199 */
51470298 7200static void ssh_size(void *handle, int width, int height)
32874aea 7201{
51470298 7202 Ssh ssh = (Ssh) handle;
ff3187f6 7203 struct Packet *pktout;
51470298 7204
7205 ssh->term_width = width;
7206 ssh->term_height = height;
f278d6f8 7207
51470298 7208 switch (ssh->state) {
374330e2 7209 case SSH_STATE_BEFORE_SIZE:
3687d221 7210 case SSH_STATE_PREPACKET:
21248260 7211 case SSH_STATE_CLOSED:
374330e2 7212 break; /* do nothing */
7213 case SSH_STATE_INTERMED:
51470298 7214 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7215 break;
7216 case SSH_STATE_SESSION:
86916870 7217 if (!ssh->cfg.nopty) {
51470298 7218 if (ssh->version == 1) {
7219 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7220 PKT_INT, ssh->term_height,
7221 PKT_INT, ssh->term_width,
32874aea 7222 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7223 } else if (ssh->mainchan) {
ff3187f6 7224 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7225 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7226 ssh2_pkt_addstring(pktout, "window-change");
7227 ssh2_pkt_addbool(pktout, 0);
7228 ssh2_pkt_adduint32(pktout, ssh->term_width);
7229 ssh2_pkt_adduint32(pktout, ssh->term_height);
7230 ssh2_pkt_adduint32(pktout, 0);
7231 ssh2_pkt_adduint32(pktout, 0);
7232 ssh2_pkt_send(ssh, pktout);
32874aea 7233 }
7234 }
7235 break;
374330e2 7236 }
7237}
7238
7239/*
125105d1 7240 * Return a list of the special codes that make sense in this
7241 * protocol.
7242 */
7243static const struct telnet_special *ssh_get_specials(void *handle)
7244{
62638676 7245 static const struct telnet_special ignore_special[] = {
7246 {"IGNORE message", TS_NOP},
9442dd57 7247 {"Repeat key exchange", TS_REKEY},
62638676 7248 };
7249 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7250 {NULL, TS_SEP},
7251 {"Break", TS_BRK},
7252 /* These are the signal names defined by draft-ietf-secsh-connect-19.
7253 * They include all the ISO C signals, but are a subset of the POSIX
7254 * required signals. */
7255 {"SIGINT (Interrupt)", TS_SIGINT},
7256 {"SIGTERM (Terminate)", TS_SIGTERM},
7257 {"SIGKILL (Kill)", TS_SIGKILL},
7258 {"SIGQUIT (Quit)", TS_SIGQUIT},
7259 {"SIGHUP (Hangup)", TS_SIGHUP},
7260 {"More signals", TS_SUBMENU},
7261 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7262 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7263 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7264 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7265 {NULL, TS_EXITMENU}
62638676 7266 };
7267 static const struct telnet_special specials_end[] = {
6f2d0cde 7268 {NULL, TS_EXITMENU}
62638676 7269 };
7270 static struct telnet_special ssh_specials[lenof(ignore_special) +
7271 lenof(ssh2_session_specials) +
7272 lenof(specials_end)];
125105d1 7273 Ssh ssh = (Ssh) handle;
62638676 7274 int i = 0;
7275#define ADD_SPECIALS(name) \
7276 do { \
7277 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7278 memcpy(&ssh_specials[i], name, sizeof name); \
7279 i += lenof(name); \
7280 } while(0)
125105d1 7281
7282 if (ssh->version == 1) {
62638676 7283 /* Don't bother offering IGNORE if we've decided the remote
7284 * won't cope with it, since we wouldn't bother sending it if
7285 * asked anyway. */
7286 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7287 ADD_SPECIALS(ignore_special);
125105d1 7288 } else if (ssh->version == 2) {
62638676 7289 ADD_SPECIALS(ignore_special);
7290 if (ssh->mainchan)
7291 ADD_SPECIALS(ssh2_session_specials);
7292 } /* else we're not ready yet */
7293
7294 if (i) {
7295 ADD_SPECIALS(specials_end);
7296 return ssh_specials;
7297 } else {
125105d1 7298 return NULL;
62638676 7299 }
7300#undef ADD_SPECIALS
125105d1 7301}
7302
7303/*
6abbf9e3 7304 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7305 * can send an EOF and collect resulting output (e.g. `plink
7306 * hostname sort').
374330e2 7307 */
51470298 7308static void ssh_special(void *handle, Telnet_Special code)
32874aea 7309{
51470298 7310 Ssh ssh = (Ssh) handle;
ff3187f6 7311 struct Packet *pktout;
51470298 7312
6abbf9e3 7313 if (code == TS_EOF) {
51470298 7314 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7315 /*
7316 * Buffer the EOF in case we are pre-SESSION, so we can
7317 * send it as soon as we reach SESSION.
7318 */
7319 if (code == TS_EOF)
51470298 7320 ssh->eof_needed = TRUE;
32874aea 7321 return;
7322 }
51470298 7323 if (ssh->version == 1) {
7324 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7325 } else if (ssh->mainchan) {
ff3187f6 7326 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7327 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7328 ssh2_pkt_send(ssh, pktout);
32874aea 7329 }
7330 logevent("Sent EOF message");
125105d1 7331 } else if (code == TS_PING || code == TS_NOP) {
51470298 7332 if (ssh->state == SSH_STATE_CLOSED
7333 || ssh->state == SSH_STATE_PREPACKET) return;
7334 if (ssh->version == 1) {
7335 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7336 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7337 } else {
ff3187f6 7338 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7339 ssh2_pkt_addstring_start(pktout);
590f6a5f 7340 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7341 }
9442dd57 7342 } else if (code == TS_REKEY) {
7343 if (!ssh->kex_in_progress && ssh->version == 2) {
7344 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7345 " user request", -1, NULL);
7346 }
125105d1 7347 } else if (code == TS_BRK) {
7348 if (ssh->state == SSH_STATE_CLOSED
7349 || ssh->state == SSH_STATE_PREPACKET) return;
7350 if (ssh->version == 1) {
7351 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7352 } else if (ssh->mainchan) {
ff3187f6 7353 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7354 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7355 ssh2_pkt_addstring(pktout, "break");
7356 ssh2_pkt_addbool(pktout, 0);
7357 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7358 ssh2_pkt_send(ssh, pktout);
125105d1 7359 }
6abbf9e3 7360 } else {
6f2d0cde 7361 /* Is is a POSIX signal? */
7362 char *signame = NULL;
7363 if (code == TS_SIGABRT) signame = "ABRT";
7364 if (code == TS_SIGALRM) signame = "ALRM";
7365 if (code == TS_SIGFPE) signame = "FPE";
7366 if (code == TS_SIGHUP) signame = "HUP";
7367 if (code == TS_SIGILL) signame = "ILL";
7368 if (code == TS_SIGINT) signame = "INT";
7369 if (code == TS_SIGKILL) signame = "KILL";
7370 if (code == TS_SIGPIPE) signame = "PIPE";
7371 if (code == TS_SIGQUIT) signame = "QUIT";
7372 if (code == TS_SIGSEGV) signame = "SEGV";
7373 if (code == TS_SIGTERM) signame = "TERM";
7374 if (code == TS_SIGUSR1) signame = "USR1";
7375 if (code == TS_SIGUSR2) signame = "USR2";
7376 /* The SSH-2 protocol does in principle support arbitrary named
7377 * signals, including signame@domain, but we don't support those. */
7378 if (signame) {
7379 /* It's a signal. */
7380 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7381 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7382 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7383 ssh2_pkt_addstring(pktout, "signal");
7384 ssh2_pkt_addbool(pktout, 0);
7385 ssh2_pkt_addstring(pktout, signame);
7386 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7387 logeventf(ssh, "Sent signal SIG%s", signame);
7388 }
7389 } else {
7390 /* Never heard of it. Do nothing */
7391 }
6abbf9e3 7392 }
374330e2 7393}
7394
51470298 7395void *new_sock_channel(void *handle, Socket s)
d74d141c 7396{
51470298 7397 Ssh ssh = (Ssh) handle;
d74d141c 7398 struct ssh_channel *c;
3d88e64d 7399 c = snew(struct ssh_channel);
51470298 7400 c->ssh = ssh;
d74d141c 7401
7402 if (c) {
bc240b21 7403 c->remoteid = -1; /* to be set when open confirmed */
51470298 7404 c->localid = alloc_channel_id(ssh);
d74d141c 7405 c->closes = 0;
bc240b21 7406 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7407 c->u.pfd.s = s;
013dd8c0 7408 bufchain_init(&c->v.v2.outbuffer);
51470298 7409 add234(ssh->channels, c);
d74d141c 7410 }
7411 return c;
7412}
7413
5471d09a 7414/*
7415 * This is called when stdout/stderr (the entity to which
7416 * from_backend sends data) manages to clear some backlog.
7417 */
ae9ae89f 7418static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7419{
51470298 7420 Ssh ssh = (Ssh) handle;
7421 if (ssh->version == 1) {
7422 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7423 ssh->v1_stdout_throttling = 0;
7424 ssh1_throttle(ssh, -1);
5471d09a 7425 }
7426 } else {
51470298 7427 if (ssh->mainchan && ssh->mainchan->closes == 0)
7428 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7429 }
7430}
7431
6b78788a 7432void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7433{
7434 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7435 Ssh ssh = c->ssh;
ff3187f6 7436 struct Packet *pktout;
d74d141c 7437
57356d63 7438 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7439
51470298 7440 if (ssh->version == 1) {
7441 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7442 PKT_INT, c->localid,
7443 PKT_STR, hostname,
7444 PKT_INT, port,
7445 //PKT_STR, <org:orgport>,
7446 PKT_END);
7447 } else {
ff3187f6 7448 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7449 ssh2_pkt_addstring(pktout, "direct-tcpip");
7450 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7451 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7452 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7453 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7454 ssh2_pkt_addstring(pktout, hostname);
7455 ssh2_pkt_adduint32(pktout, port);
bc240b21 7456 /*
7457 * We make up values for the originator data; partly it's
7458 * too much hassle to keep track, and partly I'm not
7459 * convinced the server should be told details like that
7460 * about my local network configuration.
7461 */
ff3187f6 7462 ssh2_pkt_addstring(pktout, "client-side-connection");
7463 ssh2_pkt_adduint32(pktout, 0);
7464 ssh2_pkt_send(ssh, pktout);
bc240b21 7465 }
d74d141c 7466}
7467
51470298 7468static Socket ssh_socket(void *handle)
32874aea 7469{
51470298 7470 Ssh ssh = (Ssh) handle;
7471 return ssh->s;
32874aea 7472}
8ccc75b0 7473
51470298 7474static int ssh_sendok(void *handle)
32874aea 7475{
51470298 7476 Ssh ssh = (Ssh) handle;
7477 return ssh->send_ok;
32874aea 7478}
fb09bf1c 7479
51470298 7480static int ssh_ldisc(void *handle, int option)
32874aea 7481{
51470298 7482 Ssh ssh = (Ssh) handle;
32874aea 7483 if (option == LD_ECHO)
51470298 7484 return ssh->echoing;
32874aea 7485 if (option == LD_EDIT)
51470298 7486 return ssh->editing;
0965bee0 7487 return FALSE;
7488}
7489
b9d7bcad 7490static void ssh_provide_ldisc(void *handle, void *ldisc)
7491{
7492 Ssh ssh = (Ssh) handle;
7493 ssh->ldisc = ldisc;
7494}
7495
a8327734 7496static void ssh_provide_logctx(void *handle, void *logctx)
7497{
7498 Ssh ssh = (Ssh) handle;
7499 ssh->logctx = logctx;
7500}
7501
51470298 7502static int ssh_return_exitcode(void *handle)
7503{
7504 Ssh ssh = (Ssh) handle;
3bb2f322 7505 if (ssh->s != NULL)
7506 return -1;
7507 else
7508 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7509}
7510
7511/*
7512 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7513 * that fails. This variable is the means by which scp.c can reach
7514 * into the SSH code and find out which one it got.
7515 */
7516extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7517{
51470298 7518 Ssh ssh = (Ssh) handle;
7519 return ssh->fallback_cmd;
d8d6c7e5 7520}
7521
374330e2 7522Backend ssh_backend = {
7523 ssh_init,
fabd1805 7524 ssh_free,
86916870 7525 ssh_reconfig,
374330e2 7526 ssh_send,
5471d09a 7527 ssh_sendbuffer,
374330e2 7528 ssh_size,
4017be6d 7529 ssh_special,
125105d1 7530 ssh_get_specials,
8ccc75b0 7531 ssh_socket,
d8d6c7e5 7532 ssh_return_exitcode,
97db3be4 7533 ssh_sendok,
0965bee0 7534 ssh_ldisc,
b9d7bcad 7535 ssh_provide_ldisc,
a8327734 7536 ssh_provide_logctx,
5471d09a 7537 ssh_unthrottle,
97db3be4 7538 22
bc240b21 7539};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator