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And now I look at it, the latest draft also says version strings
[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
d38d6a1f 2070/*
2071 * The `software version' part of an SSH version string is required
2072 * to contain no spaces or minus signs.
2073 */
2074static void ssh_fix_verstring(char *str)
2075{
2076 /* Eat "SSH-<protoversion>-". */
2077 assert(*str == 'S'); str++;
2078 assert(*str == 'S'); str++;
2079 assert(*str == 'H'); str++;
2080 assert(*str == '-'); str++;
2081 while (*str && *str != '-') str++;
2082 assert(*str == '-'); str++;
2083
2084 /* Convert minus signs and spaces in the remaining string into
2085 * underscores. */
2086 while (*str) {
2087 if (*str == '-' || *str == ' ')
2088 *str = '_';
2089 str++;
2090 }
2091}
2092
51470298 2093static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2094{
51470298 2095 struct do_ssh_init_state {
2096 int vslen;
2097 char version[10];
2098 char *vstring;
2099 int vstrsize;
2100 int i;
2101 int proto1, proto2;
2102 };
2103 crState(do_ssh_init_state);
374330e2 2104
51470298 2105 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2106
2107 /* Search for the string "SSH-" in the input. */
51470298 2108 s->i = 0;
8df7a775 2109 while (1) {
2110 static const int transS[] = { 1, 2, 2, 1 };
2111 static const int transH[] = { 0, 0, 3, 0 };
2112 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2113 if (c == 'S')
51470298 2114 s->i = transS[s->i];
32874aea 2115 else if (c == 'H')
51470298 2116 s->i = transH[s->i];
32874aea 2117 else if (c == '-')
51470298 2118 s->i = transminus[s->i];
32874aea 2119 else
51470298 2120 s->i = 0;
2121 if (s->i < 0)
8df7a775 2122 break;
2123 crReturn(1); /* get another character */
374330e2 2124 }
8df7a775 2125
51470298 2126 s->vstrsize = 16;
3d88e64d 2127 s->vstring = snewn(s->vstrsize, char);
51470298 2128 strcpy(s->vstring, "SSH-");
2129 s->vslen = 4;
2130 s->i = 0;
374330e2 2131 while (1) {
8df7a775 2132 crReturn(1); /* get another char */
51470298 2133 if (s->vslen >= s->vstrsize - 1) {
2134 s->vstrsize += 16;
3d88e64d 2135 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2136 }
51470298 2137 s->vstring[s->vslen++] = c;
2138 if (s->i >= 0) {
374330e2 2139 if (c == '-') {
51470298 2140 s->version[s->i] = '\0';
2141 s->i = -1;
2142 } else if (s->i < sizeof(s->version) - 1)
2143 s->version[s->i++] = c;
c4ffc4d0 2144 } else if (c == '\012')
374330e2 2145 break;
2146 }
2147
51470298 2148 ssh->agentfwd_enabled = FALSE;
2149 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2150
51470298 2151 s->vstring[s->vslen] = 0;
2152 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
2153 {
2154 char *vlog;
3d88e64d 2155 vlog = snewn(20 + s->vslen, char);
51470298 2156 sprintf(vlog, "Server version: %s", s->vstring);
2157 logevent(vlog);
2158 sfree(vlog);
2159 }
2160 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2161
adf799dd 2162 /*
38d228a2 2163 * Decide which SSH protocol version to support.
adf799dd 2164 */
38d228a2 2165
2166 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2167 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2168 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2169 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2170
86916870 2171 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2172 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2173 crStop(0);
38d228a2 2174 }
86916870 2175 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2176 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2177 crStop(0);
38d228a2 2178 }
2179
d38d6a1f 2180 {
2181 char *verstring;
2182
2183 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2184 /*
2185 * Construct a v2 version string.
2186 */
0b351b6b 2187 verstring = dupprintf("SSH-2.0-%s\r\n", sshver);
d38d6a1f 2188 ssh->version = 2;
2189 } else {
2190 /*
2191 * Construct a v1 version string.
2192 */
0b351b6b 2193 verstring = dupprintf("SSH-%s-%s\r\n",
d38d6a1f 2194 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2195 s->version : "1.5"),
2196 sshver);
2197 ssh->version = 1;
2198 }
2199
2200 ssh_fix_verstring(verstring);
2201
2202 if (ssh->version == 2) {
2203 /*
2204 * Hash our version string and their version string.
2205 */
2206 SHA_Init(&ssh->exhashbase);
0b351b6b 2207 sha_string(&ssh->exhashbase, verstring,
2208 strcspn(verstring, "\r\n"));
2209 sha_string(&ssh->exhashbase, s->vstring,
2210 strcspn(s->vstring, "\r\n"));
d38d6a1f 2211
2212 /*
2213 * Initialise SSHv2 protocol.
2214 */
2215 ssh->protocol = ssh2_protocol;
2216 ssh2_protocol_setup(ssh);
2217 ssh->s_rdpkt = ssh2_rdpkt;
2218 } else {
2219 /*
2220 * Initialise SSHv1 protocol.
2221 */
2222 ssh->protocol = ssh1_protocol;
2223 ssh1_protocol_setup(ssh);
2224 ssh->s_rdpkt = ssh1_rdpkt;
2225 }
2226 logeventf(ssh, "We claim version: %.*s",
0b351b6b 2227 strcspn(verstring, "\r\n"), verstring);
51470298 2228 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2229 sfree(verstring);
e5574168 2230 }
d38d6a1f 2231
2232 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2233
125105d1 2234 update_specials_menu(ssh->frontend);
51470298 2235 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2236 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2237
51470298 2238 sfree(s->vstring);
50526e47 2239
8df7a775 2240 crFinish(0);
2241}
2242
51470298 2243static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2244{
51470298 2245 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2246
2247 /*
2248 * To begin with, feed the characters one by one to the
2249 * protocol initialisation / selection function do_ssh_init().
2250 * When that returns 0, we're done with the initial greeting
2251 * exchange and can move on to packet discipline.
2252 */
2253 while (1) {
51470298 2254 int ret; /* need not be kept across crReturn */
8df7a775 2255 if (datalen == 0)
2256 crReturnV; /* more data please */
51470298 2257 ret = do_ssh_init(ssh, *data);
32874aea 2258 data++;
2259 datalen--;
8df7a775 2260 if (ret == 0)
2261 break;
2262 }
2263
2264 /*
2265 * We emerge from that loop when the initial negotiation is
2266 * over and we have selected an s_rdpkt function. Now pass
2267 * everything to s_rdpkt, and then pass the resulting packets
2268 * to the proper protocol handler.
2269 */
2270 if (datalen == 0)
2271 crReturnV;
2272 while (1) {
2273 while (datalen > 0) {
ff3187f6 2274 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2275 if (pktin) {
2276 ssh->protocol(ssh, NULL, 0, pktin);
2277 ssh_free_packet(pktin);
8df7a775 2278 }
ff3187f6 2279 if (ssh->state == SSH_STATE_CLOSED)
2280 return;
8df7a775 2281 }
2282 crReturnV;
2283 }
2284 crFinishV;
2285}
2286
36f94d1f 2287static void ssh_do_close(Ssh ssh)
32874aea 2288{
36f94d1f 2289 int i;
2290 struct ssh_channel *c;
2291
51470298 2292 ssh->state = SSH_STATE_CLOSED;
2293 if (ssh->s) {
2294 sk_close(ssh->s);
2295 ssh->s = NULL;
39934deb 2296 notify_remote_exit(ssh->frontend);
f3ab576e 2297 }
36f94d1f 2298 /*
2299 * Now we must shut down any port and X forwardings going
2300 * through this connection.
2301 */
74a98066 2302 if (ssh->channels) {
2303 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2304 switch (c->type) {
2305 case CHAN_X11:
2306 x11_close(c->u.x11.s);
2307 break;
2308 case CHAN_SOCKDATA:
2309 pfd_close(c->u.pfd.s);
2310 break;
2311 }
2312 del234(ssh->channels, c);
2313 if (ssh->version == 2)
2314 bufchain_clear(&c->v.v2.outbuffer);
2315 sfree(c);
36f94d1f 2316 }
36f94d1f 2317 }
2318}
2319
cbe2d68f 2320static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2321 int calling_back)
2322{
2323 Ssh ssh = (Ssh) plug;
2324 ssh_do_close(ssh);
7e78000d 2325 if (error_msg) {
32874aea 2326 /* A socket error has occurred. */
247308b5 2327 logevent(error_msg);
971bcc0a 2328 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2329 } else {
2330 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2331 }
7e78000d 2332 return 0;
2333}
2334
32874aea 2335static int ssh_receive(Plug plug, int urgent, char *data, int len)
2336{
51470298 2337 Ssh ssh = (Ssh) plug;
d8baa528 2338 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2339 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2340 ssh_do_close(ssh);
32874aea 2341 return 0;
3257deae 2342 }
fef97f43 2343 return 1;
374330e2 2344}
2345
5471d09a 2346static void ssh_sent(Plug plug, int bufsize)
2347{
51470298 2348 Ssh ssh = (Ssh) plug;
5471d09a 2349 /*
2350 * If the send backlog on the SSH socket itself clears, we
2351 * should unthrottle the whole world if it was throttled.
2352 */
2353 if (bufsize < SSH_MAX_BACKLOG)
51470298 2354 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2355}
2356
fb09bf1c 2357/*
8df7a775 2358 * Connect to specified host and port.
2359 * Returns an error message, or NULL on success.
6e1ebb76 2360 * Also places the canonical host name into `realhost'. It must be
2361 * freed by the caller.
8df7a775 2362 */
cbe2d68f 2363static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2364 char **realhost, int nodelay, int keepalive)
8df7a775 2365{
51470298 2366 static const struct plug_function_table fn_table = {
7e78000d 2367 ssh_closing,
5471d09a 2368 ssh_receive,
2369 ssh_sent,
2370 NULL
51470298 2371 };
7e78000d 2372
8df7a775 2373 SockAddr addr;
cbe2d68f 2374 const char *err;
8df7a775 2375
3d88e64d 2376 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2377 if (!ssh->savedhost)
8df7a775 2378 fatalbox("Out of memory");
51470298 2379 strcpy(ssh->savedhost, host);
8df7a775 2380
2381 if (port < 0)
2382 port = 22; /* default ssh port */
51470298 2383 ssh->savedport = port;
8df7a775 2384
2385 /*
2386 * Try to find host.
2387 */
57356d63 2388 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2389 addr = name_lookup(host, port, realhost, &ssh->cfg);
170c1e6e 2390 if ((err = sk_addr_error(addr)) != NULL) {
2391 sk_addr_free(addr);
8df7a775 2392 return err;
170c1e6e 2393 }
8df7a775 2394
8df7a775 2395 /*
2396 * Open socket.
2397 */
3ad9d396 2398 {
57356d63 2399 char addrbuf[100];
3ad9d396 2400 sk_getaddr(addr, addrbuf, 100);
57356d63 2401 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2402 }
51470298 2403 ssh->fn = &fn_table;
e8fa8f62 2404 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2405 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2406 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2407 ssh->s = NULL;
39934deb 2408 notify_remote_exit(ssh->frontend);
8df7a775 2409 return err;
67c4ba2e 2410 }
8df7a775 2411
8df7a775 2412 return NULL;
2413}
2414
2415/*
5471d09a 2416 * Throttle or unthrottle the SSH connection.
2417 */
51470298 2418static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2419{
51470298 2420 int old_count = ssh->v1_throttle_count;
2421 ssh->v1_throttle_count += adjust;
2422 assert(ssh->v1_throttle_count >= 0);
2423 if (ssh->v1_throttle_count && !old_count) {
2424 sk_set_frozen(ssh->s, 1);
2425 } else if (!ssh->v1_throttle_count && old_count) {
2426 sk_set_frozen(ssh->s, 0);
5471d09a 2427 }
2428}
2429
2430/*
2431 * Throttle or unthrottle _all_ local data streams (for when sends
2432 * on the SSH connection itself back up).
2433 */
51470298 2434static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2435{
2436 int i;
2437 struct ssh_channel *c;
2438
51470298 2439 if (enable == ssh->throttled_all)
5471d09a 2440 return;
51470298 2441 ssh->throttled_all = enable;
2442 ssh->overall_bufsize = bufsize;
2443 if (!ssh->channels)
5471d09a 2444 return;
51470298 2445 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2446 switch (c->type) {
2447 case CHAN_MAINSESSION:
2448 /*
2449 * This is treated separately, outside the switch.
2450 */
2451 break;
2452 case CHAN_X11:
2453 x11_override_throttle(c->u.x11.s, enable);
2454 break;
2455 case CHAN_AGENT:
2456 /* Agent channels require no buffer management. */
2457 break;
2458 case CHAN_SOCKDATA:
36f94d1f 2459 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2460 break;
2461 }
2462 }
2463}
2464
2465/*
51470298 2466 * Username and password input, abstracted off into routines
2467 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2468 */
0405e71f 2469
2470/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2471static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2472{
51470298 2473 ssh->userpass_input_buffer = buffer;
2474 ssh->userpass_input_buflen = buflen;
2475 ssh->userpass_input_bufpos = 0;
2476 ssh->userpass_input_echo = echo;
0405e71f 2477}
2478
2479/*
2480 * Process some terminal data in the course of username/password
2481 * input. Returns >0 for success (line of input returned in
2482 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2483 * for inconclusive (keep waiting for more input please).
2484 */
ae9ae89f 2485static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2486{
2487 char c;
2488
2489 while (inlen--) {
2490 switch (c = *in++) {
2491 case 10:
2492 case 13:
51470298 2493 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2494 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2495 return +1;
2496 break;
2497 case 8:
2498 case 127:
51470298 2499 if (ssh->userpass_input_bufpos > 0) {
2500 if (ssh->userpass_input_echo)
2501 c_write_str(ssh, "\b \b");
2502 ssh->userpass_input_bufpos--;
0405e71f 2503 }
2504 break;
2505 case 21:
2506 case 27:
51470298 2507 while (ssh->userpass_input_bufpos > 0) {
2508 if (ssh->userpass_input_echo)
2509 c_write_str(ssh, "\b \b");
2510 ssh->userpass_input_bufpos--;
0405e71f 2511 }
2512 break;
2513 case 3:
2514 case 4:
2515 return -1;
2516 break;
2517 default:
4692a14a 2518 /*
2519 * This simplistic check for printability is disabled
2520 * when we're doing password input, because some people
2521 * have control characters in their passwords.o
2522 */
2523 if ((!ssh->userpass_input_echo ||
2524 (c >= ' ' && c <= '~') ||
0405e71f 2525 ((unsigned char) c >= 160))
51470298 2526 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2527 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2528 if (ssh->userpass_input_echo)
2529 c_write(ssh, &c, 1);
0405e71f 2530 }
2531 break;
2532 }
2533 }
2534 return 0;
2535}
2536
f11d78f2 2537static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2538{
2539 Ssh ssh = (Ssh) sshv;
2540
2541 ssh->agent_response = reply;
2542 ssh->agent_response_len = replylen;
2543
2544 if (ssh->version == 1)
ff3187f6 2545 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2546 else
ff3187f6 2547 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2548}
2549
f11d78f2 2550static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2551{
2552 struct ssh_channel *c = (struct ssh_channel *)cv;
2553 Ssh ssh = c->ssh;
2554 void *sentreply = reply;
2555
2556 if (!sentreply) {
2557 /* Fake SSH_AGENT_FAILURE. */
2558 sentreply = "\0\0\0\1\5";
2559 replylen = 5;
2560 }
2561 if (ssh->version == 2) {
2562 ssh2_add_channel_data(c, sentreply, replylen);
2563 ssh2_try_send(c);
2564 } else {
2565 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2566 PKT_INT, c->remoteid,
9a10ecf4 2567 PKTT_DATA,
839f10db 2568 PKT_INT, replylen,
2569 PKT_DATA, sentreply, replylen,
9a10ecf4 2570 PKTT_OTHER,
839f10db 2571 PKT_END);
2572 }
2573 if (reply)
2574 sfree(reply);
2575}
2576
0405e71f 2577/*
fb09bf1c 2578 * Handle the key exchange and user authentication phases.
2579 */
ff3187f6 2580static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2581 struct Packet *pktin)
fb09bf1c 2582{
0016d70b 2583 int i, j, ret;
2584 unsigned char cookie[8], *ptr;
374330e2 2585 struct RSAKey servkey, hostkey;
2586 struct MD5Context md5c;
51470298 2587 struct do_ssh1_login_state {
2588 int len;
2589 unsigned char *rsabuf, *keystr1, *keystr2;
2590 unsigned long supported_ciphers_mask, supported_auths_mask;
2591 int tried_publickey, tried_agent;
2592 int tis_auth_refused, ccard_auth_refused;
2593 unsigned char session_id[16];
2594 int cipher_type;
2595 char username[100];
2596 void *publickey_blob;
2597 int publickey_bloblen;
2598 char password[100];
2599 char prompt[200];
2600 int pos;
2601 char c;
2602 int pwpkt_type;
2603 unsigned char request[5], *response, *p;
2604 int responselen;
2605 int keyi, nkeys;
2606 int authed;
2607 struct RSAKey key;
2608 Bignum challenge;
2609 char *commentp;
2610 int commentlen;
2611 };
2612 crState(do_ssh1_login_state);
2613
2614 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2615
ff3187f6 2616 if (!pktin)
2617 crWaitUntil(pktin);
374330e2 2618
ff3187f6 2619 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2620 bombout(("Public key packet not received"));
7ffdbc1a 2621 crStop(0);
8d5de777 2622 }
374330e2 2623
c5e9c988 2624 logevent("Received public keys");
374330e2 2625
ff3187f6 2626 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2627 if (!ptr) {
2628 bombout(("SSH1 public key packet stopped before random cookie"));
2629 crStop(0);
2630 }
2631 memcpy(cookie, ptr, 8);
374330e2 2632
ff3187f6 2633 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2634 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2635 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2636 crStop(0);
2637 }
374330e2 2638
c5e9c988 2639 /*
1c2a93c4 2640 * Log the host key fingerprint.
c5e9c988 2641 */
c5e9c988 2642 {
2643 char logmsg[80];
1c2a93c4 2644 logevent("Host key fingerprint is:");
c5e9c988 2645 strcpy(logmsg, " ");
32874aea 2646 hostkey.comment = NULL;
2647 rsa_fingerprint(logmsg + strlen(logmsg),
2648 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2649 logevent(logmsg);
2650 }
2651
ff3187f6 2652 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2653 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2654 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2655
51470298 2656 ssh->v1_local_protoflags =
2657 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2658 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2659
c5e9c988 2660 MD5Init(&md5c);
51470298 2661 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2662 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2663 MD5Update(&md5c, cookie, 8);
51470298 2664 MD5Final(s->session_id, &md5c);
374330e2 2665
32874aea 2666 for (i = 0; i < 32; i++)
51470298 2667 ssh->session_key[i] = random_byte();
374330e2 2668
0016d70b 2669 /*
2670 * Verify that the `bits' and `bytes' parameters match.
2671 */
2672 if (hostkey.bits > hostkey.bytes * 8 ||
2673 servkey.bits > servkey.bytes * 8) {
2674 bombout(("SSH1 public keys were badly formatted"));
2675 crStop(0);
2676 }
2677
51470298 2678 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2679
3d88e64d 2680 s->rsabuf = snewn(s->len, unsigned char);
51470298 2681 if (!s->rsabuf)
374330e2 2682 fatalbox("Out of memory");
2683
89ee5268 2684 /*
2685 * Verify the host key.
2686 */
2687 {
32874aea 2688 /*
2689 * First format the key into a string.
2690 */
2691 int len = rsastr_len(&hostkey);
2692 char fingerprint[100];
3d88e64d 2693 char *keystr = snewn(len, char);
32874aea 2694 if (!keystr)
2695 fatalbox("Out of memory");
2696 rsastr_fmt(keystr, &hostkey);
2697 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2698 verify_ssh_host_key(ssh->frontend,
2699 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2700 fingerprint);
2701 sfree(keystr);
2702 }
2703
2704 for (i = 0; i < 32; i++) {
51470298 2705 s->rsabuf[i] = ssh->session_key[i];
374330e2 2706 if (i < 16)
51470298 2707 s->rsabuf[i] ^= s->session_id[i];
374330e2 2708 }
2709
2710 if (hostkey.bytes > servkey.bytes) {
0016d70b 2711 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2712 if (ret)
2713 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2714 } else {
0016d70b 2715 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2716 if (ret)
2717 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2718 }
2719 if (!ret) {
2720 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2721 crStop(0);
374330e2 2722 }
2723
c5e9c988 2724 logevent("Encrypted session key");
2725
ca20bfcf 2726 {
2727 int cipher_chosen = 0, warn = 0;
2728 char *cipher_string = NULL;
51470298 2729 int i;
ca20bfcf 2730 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2731 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2732 if (next_cipher == CIPHER_WARN) {
2733 /* If/when we choose a cipher, warn about it */
2734 warn = 1;
2735 } else if (next_cipher == CIPHER_AES) {
2736 /* XXX Probably don't need to mention this. */
2737 logevent("AES not supported in SSH1, skipping");
2738 } else {
2739 switch (next_cipher) {
51470298 2740 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2741 cipher_string = "3DES"; break;
51470298 2742 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2743 cipher_string = "Blowfish"; break;
51470298 2744 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2745 cipher_string = "single-DES"; break;
2746 }
51470298 2747 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2748 cipher_chosen = 1;
2749 }
2750 }
2751 if (!cipher_chosen) {
51470298 2752 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2753 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2754 "supporting 3DES encryption"));
2755 else
2756 /* shouldn't happen */
6b5cf8b4 2757 bombout(("No supported ciphers found"));
7ffdbc1a 2758 crStop(0);
a99a05c0 2759 }
ca20bfcf 2760
2761 /* Warn about chosen cipher if necessary. */
2762 if (warn)
a8327734 2763 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2764 }
ca20bfcf 2765
51470298 2766 switch (s->cipher_type) {
32874aea 2767 case SSH_CIPHER_3DES:
2768 logevent("Using 3DES encryption");
2769 break;
2770 case SSH_CIPHER_DES:
2771 logevent("Using single-DES encryption");
2772 break;
2773 case SSH_CIPHER_BLOWFISH:
2774 logevent("Using Blowfish encryption");
2775 break;
c5e9c988 2776 }
bea1ef5f 2777
51470298 2778 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2779 PKT_CHAR, s->cipher_type,
32874aea 2780 PKT_DATA, cookie, 8,
51470298 2781 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2782 PKT_DATA, s->rsabuf, s->len,
2783 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2784
c5e9c988 2785 logevent("Trying to enable encryption...");
374330e2 2786
51470298 2787 sfree(s->rsabuf);
374330e2 2788
51470298 2789 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2790 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2791 &ssh_3des);
371e569c 2792 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2793 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2794 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2795
0183b242 2796 ssh->crcda_ctx = crcda_make_context();
2797 logevent("Installing CRC compensation attack detector");
2798
679539d7 2799 if (servkey.modulus) {
2800 sfree(servkey.modulus);
2801 servkey.modulus = NULL;
2802 }
2803 if (servkey.exponent) {
2804 sfree(servkey.exponent);
2805 servkey.exponent = NULL;
2806 }
2807 if (hostkey.modulus) {
2808 sfree(hostkey.modulus);
2809 hostkey.modulus = NULL;
2810 }
2811 if (hostkey.exponent) {
2812 sfree(hostkey.exponent);
2813 hostkey.exponent = NULL;
2814 }
ff3187f6 2815 crWaitUntil(pktin);
374330e2 2816
ff3187f6 2817 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2818 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2819 crStop(0);
8d5de777 2820 }
374330e2 2821
c5e9c988 2822 logevent("Successfully started encryption");
2823
374330e2 2824 fflush(stdout);
2825 {
aa09f7d0 2826 if (!*ssh->cfg.username) {
c0a81592 2827 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2828 if (!ssh_get_line("login as: ",
51470298 2829 s->username, sizeof(s->username), FALSE)) {
32874aea 2830 /*
2831 * get_line failed to get a username.
2832 * Terminate.
2833 */
2834 logevent("No username provided. Abandoning session.");
3bb2f322 2835 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2836 crStop(1);
32874aea 2837 }
2838 } else {
51470298 2839 int ret; /* need not be kept over crReturn */
2840 c_write_str(ssh, "login as: ");
2841 ssh->send_ok = 1;
0405e71f 2842
51470298 2843 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2844 do {
ff3187f6 2845 crWaitUntil(!pktin);
51470298 2846 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2847 } while (ret == 0);
2848 if (ret < 0)
2849 cleanup_exit(0);
51470298 2850 c_write_str(ssh, "\r\n");
32874aea 2851 }
2852 } else {
86916870 2853 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2854 s->username[sizeof(s->username)-1] = '\0';
374330e2 2855 }
fb09bf1c 2856
51470298 2857 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2858 {
51470298 2859 char userlog[22 + sizeof(s->username)];
2860 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2861 logevent(userlog);
32874aea 2862 if (flags & FLAG_INTERACTIVE &&
2863 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2864 strcat(userlog, "\r\n");
51470298 2865 c_write_str(ssh, userlog);
3c8e959b 2866 }
c5e9c988 2867 }
374330e2 2868 }
2869
ff3187f6 2870 crWaitUntil(pktin);
374330e2 2871
51470298 2872 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2873 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2874 s->tried_publickey = s->tried_agent = 1;
0df73905 2875 } else {
51470298 2876 s->tried_publickey = s->tried_agent = 0;
0df73905 2877 }
51470298 2878 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2879 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2880 if (!filename_is_null(ssh->cfg.keyfile)) {
2881 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2882 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2883 s->publickey_blob = NULL;
396778f1 2884 } else
51470298 2885 s->publickey_blob = NULL;
7cca0d81 2886
ff3187f6 2887 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 2888 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2889
51470298 2890 if (agent_exists() && !s->tried_agent) {
32874aea 2891 /*
2892 * Attempt RSA authentication using Pageant.
2893 */
32874aea 2894 void *r;
2895
51470298 2896 s->authed = FALSE;
2897 s->tried_agent = 1;
32874aea 2898 logevent("Pageant is running. Requesting keys.");
2899
2900 /* Request the keys held by the agent. */
51470298 2901 PUT_32BIT(s->request, 1);
2902 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2903 if (!agent_query(s->request, 5, &r, &s->responselen,
2904 ssh_agent_callback, ssh)) {
2905 do {
2906 crReturn(0);
ff3187f6 2907 if (pktin) {
839f10db 2908 bombout(("Unexpected data from server while waiting"
2909 " for agent response"));
2910 crStop(0);
2911 }
ff3187f6 2912 } while (pktin || inlen > 0);
839f10db 2913 r = ssh->agent_response;
2914 s->responselen = ssh->agent_response_len;
2915 }
51470298 2916 s->response = (unsigned char *) r;
2917 if (s->response && s->responselen >= 5 &&
2918 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2919 s->p = s->response + 5;
2920 s->nkeys = GET_32BIT(s->p);
2921 s->p += 4;
32874aea 2922 {
2923 char buf[64];
51470298 2924 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2925 logevent(buf);
2926 }
51470298 2927 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2928 {
2929 char buf[64];
51470298 2930 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2931 logevent(buf);
2932 }
51470298 2933 if (s->publickey_blob &&
2934 !memcmp(s->p, s->publickey_blob,
2935 s->publickey_bloblen)) {
396778f1 2936 logevent("This key matches configured key file");
51470298 2937 s->tried_publickey = 1;
396778f1 2938 }
51470298 2939 s->p += 4;
0016d70b 2940 {
2941 int n, ok = FALSE;
2942 do { /* do while (0) to make breaking easy */
2943 n = ssh1_read_bignum
2944 (s->p, s->responselen-(s->p-s->response),
2945 &s->key.exponent);
2946 if (n < 0)
2947 break;
2948 s->p += n;
2949 n = ssh1_read_bignum
2950 (s->p, s->responselen-(s->p-s->response),
2951 &s->key.modulus);
2952 if (n < 0)
2953 break;
2954 s->p += n;
2955 if (s->responselen - (s->p-s->response) < 4)
2956 break;
2957 s->commentlen = GET_32BIT(s->p);
2958 s->p += 4;
2959 if (s->responselen - (s->p-s->response) <
2960 s->commentlen)
2961 break;
2962 s->commentp = (char *)s->p;
2963 s->p += s->commentlen;
2964 ok = TRUE;
2965 } while (0);
2966 if (!ok) {
2967 logevent("Pageant key list packet was truncated");
2968 break;
2969 }
2970 }
51470298 2971 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2972 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 2973 crWaitUntil(pktin);
2974 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2975 logevent("Key refused");
2976 continue;
2977 }
2978 logevent("Received RSA challenge");
ff3187f6 2979 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 2980 bombout(("Server's RSA challenge was badly formatted"));
2981 crStop(0);
2982 }
2983
32874aea 2984 {
2985 char *agentreq, *q, *ret;
2d466ffd 2986 void *vret;
32874aea 2987 int len, retlen;
2988 len = 1 + 4; /* message type, bit count */
51470298 2989 len += ssh1_bignum_length(s->key.exponent);
2990 len += ssh1_bignum_length(s->key.modulus);
2991 len += ssh1_bignum_length(s->challenge);
32874aea 2992 len += 16; /* session id */
2993 len += 4; /* response format */
3d88e64d 2994 agentreq = snewn(4 + len, char);
32874aea 2995 PUT_32BIT(agentreq, len);
2996 q = agentreq + 4;
2997 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2998 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2999 q += 4;
51470298 3000 q += ssh1_write_bignum(q, s->key.exponent);
3001 q += ssh1_write_bignum(q, s->key.modulus);
3002 q += ssh1_write_bignum(q, s->challenge);
3003 memcpy(q, s->session_id, 16);
32874aea 3004 q += 16;
3005 PUT_32BIT(q, 1); /* response format */
839f10db 3006 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3007 ssh_agent_callback, ssh)) {
3008 sfree(agentreq);
3009 do {
3010 crReturn(0);
ff3187f6 3011 if (pktin) {
839f10db 3012 bombout(("Unexpected data from server"
3013 " while waiting for agent"
3014 " response"));
3015 crStop(0);
3016 }
ff3187f6 3017 } while (pktin || inlen > 0);
839f10db 3018 vret = ssh->agent_response;
3019 retlen = ssh->agent_response_len;
3020 } else
3021 sfree(agentreq);
2d466ffd 3022 ret = vret;
32874aea 3023 if (ret) {
3024 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3025 logevent("Sending Pageant's response");
51470298 3026 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3027 PKT_DATA, ret + 5, 16,
3028 PKT_END);
3029 sfree(ret);
ff3187f6 3030 crWaitUntil(pktin);
3031 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3032 logevent
3033 ("Pageant's response accepted");
3034 if (flags & FLAG_VERBOSE) {
51470298 3035 c_write_str(ssh, "Authenticated using"
3036 " RSA key \"");
3037 c_write(ssh, s->commentp,
3038 s->commentlen);
3039 c_write_str(ssh, "\" from agent\r\n");
32874aea 3040 }
51470298 3041 s->authed = TRUE;
32874aea 3042 } else
3043 logevent
3044 ("Pageant's response not accepted");
3045 } else {
3046 logevent
3047 ("Pageant failed to answer challenge");
3048 sfree(ret);
3049 }
3050 } else {
3051 logevent("No reply received from Pageant");
3052 }
3053 }
51470298 3054 freebn(s->key.exponent);
3055 freebn(s->key.modulus);
3056 freebn(s->challenge);
3057 if (s->authed)
32874aea 3058 break;
3059 }
29b1d0b3 3060 sfree(s->response);
32874aea 3061 }
51470298 3062 if (s->authed)
32874aea 3063 break;
3064 }
9a30e26b 3065 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3066 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3067
86916870 3068 if (ssh->cfg.try_tis_auth &&
51470298 3069 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3070 !s->tis_auth_refused) {
3071 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3072 logevent("Requested TIS authentication");
51470298 3073 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3074 crWaitUntil(pktin);
3075 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3076 logevent("TIS authentication declined");
3077 if (flags & FLAG_INTERACTIVE)
51470298 3078 c_write_str(ssh, "TIS authentication refused.\r\n");
3079 s->tis_auth_refused = 1;
614a20a0 3080 continue;
32874aea 3081 } else {
0016d70b 3082 char *challenge;
3083 int challengelen;
3084
ff3187f6 3085 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3086 if (!challenge) {
3087 bombout(("TIS challenge packet was badly formed"));
3088 crStop(0);
3089 }
32874aea 3090 logevent("Received TIS challenge");
51470298 3091 if (challengelen > sizeof(s->prompt) - 1)
3092 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3093 memcpy(s->prompt, challenge, challengelen);
614a20a0 3094 /* Prompt heuristic comes from OpenSSH */
51470298 3095 strncpy(s->prompt + challengelen,
3096 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3097 "": "\r\nResponse: ",
51470298 3098 (sizeof s->prompt) - challengelen);
3099 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3100 }
3101 }
86916870 3102 if (ssh->cfg.try_tis_auth &&
51470298 3103 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3104 !s->ccard_auth_refused) {
3105 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3106 logevent("Requested CryptoCard authentication");
51470298 3107 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3108 crWaitUntil(pktin);
3109 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3110 logevent("CryptoCard authentication declined");
51470298 3111 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3112 s->ccard_auth_refused = 1;
614a20a0 3113 continue;
32874aea 3114 } else {
0016d70b 3115 char *challenge;
3116 int challengelen;
3117
ff3187f6 3118 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3119 if (!challenge) {
3120 bombout(("CryptoCard challenge packet was badly formed"));
3121 crStop(0);
3122 }
32874aea 3123 logevent("Received CryptoCard challenge");
51470298 3124 if (challengelen > sizeof(s->prompt) - 1)
3125 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3126 memcpy(s->prompt, challenge, challengelen);
51470298 3127 strncpy(s->prompt + challengelen,
3128 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3129 "" : "\r\nResponse: ",
51470298 3130 sizeof(s->prompt) - challengelen);
3131 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3132 }
3133 }
51470298 3134 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3135 sprintf(s->prompt, "%.90s@%.90s's password: ",
3136 s->username, ssh->savedhost);
32874aea 3137 }
51470298 3138 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3139 char *comment = NULL;
231ee168 3140 int type;
3141 char msgbuf[256];
32874aea 3142 if (flags & FLAG_VERBOSE)
51470298 3143 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3144 logeventf(ssh, "Trying public key \"%s\"",
3145 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3146 type = key_type(&ssh->cfg.keyfile);
231ee168 3147 if (type != SSH_KEYTYPE_SSH1) {
3148 sprintf(msgbuf, "Key is of wrong type (%s)",
3149 key_type_to_str(type));
3150 logevent(msgbuf);
51470298 3151 c_write_str(ssh, msgbuf);
3152 c_write_str(ssh, "\r\n");
3153 s->tried_publickey = 1;
231ee168 3154 continue;
3155 }
9a30e26b 3156 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3157 if (flags & FLAG_VERBOSE)
51470298 3158 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3159 goto tryauth;
3160 }
51470298 3161 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3162 sfree(comment);
3163 }
a52f067e 3164
614a20a0 3165 /*
3166 * Show password prompt, having first obtained it via a TIS
3167 * or CryptoCard exchange if we're doing TIS or CryptoCard
3168 * authentication.
3169 */
fa17a66e 3170 if (ssh_get_line) {
51470298 3171 if (!ssh_get_line(s->prompt, s->password,
3172 sizeof(s->password), TRUE)) {
32874aea 3173 /*
3174 * get_line failed to get a password (for example
3175 * because one was supplied on the command line
3176 * which has already failed to work). Terminate.
3177 */
51470298 3178 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3179 PKT_STR, "No more passwords available to try",
3180 PKT_END);
247308b5 3181 logevent("Unable to authenticate");
a8327734 3182 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3183 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3184 crStop(1);
32874aea 3185 }
fb09bf1c 3186 } else {
614a20a0 3187 /* Prompt may have come from server. We've munged it a bit, so
3188 * we know it to be zero-terminated at least once. */
51470298 3189 int ret; /* need not be saved over crReturn */
3190 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3191 s->pos = 0;
0405e71f 3192
51470298 3193 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3194 do {
ff3187f6 3195 crWaitUntil(!pktin);
51470298 3196 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3197 } while (ret == 0);
3198 if (ret < 0)
3199 cleanup_exit(0);
51470298 3200 c_write_str(ssh, "\r\n");
32874aea 3201 }
3202
3203 tryauth:
51470298 3204 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3205 /*
3206 * Try public key authentication with the specified
3207 * key file.
3208 */
51470298 3209 s->tried_publickey = 1;
3210
3211 {
222d54dc 3212 const char *error = NULL;
3213 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3214 &error);
51470298 3215 if (ret == 0) {
3216 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3217 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3218 c_write_str(ssh, " (");
3219 c_write_str(ssh, error);
3220 c_write_str(ssh, ").\r\n");
51470298 3221 continue; /* go and try password */
3222 }
3223 if (ret == -1) {
3224 c_write_str(ssh, "Wrong passphrase.\r\n");
3225 s->tried_publickey = 0;
3226 continue; /* try again */
3227 }
32874aea 3228 }
3229
3230 /*
3231 * Send a public key attempt.
3232 */
51470298 3233 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3234 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3235
ff3187f6 3236 crWaitUntil(pktin);
3237 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3238 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3239 continue; /* go and try password */
3240 }
ff3187f6 3241 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3242 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3243 crStop(0);
32874aea 3244 }
32874aea 3245
51470298 3246 {
3247 int i;
3248 unsigned char buffer[32];
3249 Bignum challenge, response;
3250
ff3187f6 3251 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3252 bombout(("Server's RSA challenge was badly formatted"));
3253 crStop(0);
3254 }
51470298 3255 response = rsadecrypt(challenge, &s->key);
3256 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3257
51470298 3258 for (i = 0; i < 32; i++) {
3259 buffer[i] = bignum_byte(response, 31 - i);
3260 }
3261
3262 MD5Init(&md5c);
3263 MD5Update(&md5c, buffer, 32);
3264 MD5Update(&md5c, s->session_id, 16);
3265 MD5Final(buffer, &md5c);
32874aea 3266
51470298 3267 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3268 PKT_DATA, buffer, 16, PKT_END);
3269
3270 freebn(challenge);
3271 freebn(response);
3272 }
32874aea 3273
ff3187f6 3274 crWaitUntil(pktin);
3275 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3276 if (flags & FLAG_VERBOSE)
51470298 3277 c_write_str(ssh, "Failed to authenticate with"
3278 " our public key.\r\n");
32874aea 3279 continue; /* go and try password */
ff3187f6 3280 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3281 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3282 crStop(0);
32874aea 3283 }
3284
3285 break; /* we're through! */
3286 } else {
51470298 3287 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3288 /*
3289 * Defence against traffic analysis: we send a
3290 * whole bunch of packets containing strings of
3291 * different lengths. One of these strings is the
3292 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3293 * The others are all random data in
3294 * SSH1_MSG_IGNORE packets. This way a passive
3295 * listener can't tell which is the password, and
3296 * hence can't deduce the password length.
3297 *
3298 * Anybody with a password length greater than 16
3299 * bytes is going to have enough entropy in their
3300 * password that a listener won't find it _that_
3301 * much help to know how long it is. So what we'll
3302 * do is:
3303 *
3304 * - if password length < 16, we send 15 packets
3305 * containing string lengths 1 through 15
3306 *
3307 * - otherwise, we let N be the nearest multiple
3308 * of 8 below the password length, and send 8
3309 * packets containing string lengths N through
3310 * N+7. This won't obscure the order of
3311 * magnitude of the password length, but it will
3312 * introduce a bit of extra uncertainty.
3313 *
3314 * A few servers (the old 1.2.18 through 1.2.22)
3315 * can't deal with SSH1_MSG_IGNORE. For these
3316 * servers, we need an alternative defence. We make
3317 * use of the fact that the password is interpreted
3318 * as a C string: so we can append a NUL, then some
3319 * random data.
bd358db1 3320 *
3321 * One server (a Cisco one) can deal with neither
3322 * SSH1_MSG_IGNORE _nor_ a padded password string.
3323 * For this server we are left with no defences
3324 * against password length sniffing.
32874aea 3325 */
51470298 3326 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3327 /*
3328 * The server can deal with SSH1_MSG_IGNORE, so
3329 * we can use the primary defence.
3330 */
32874aea 3331 int bottom, top, pwlen, i;
3332 char *randomstr;
3333
51470298 3334 pwlen = strlen(s->password);
32874aea 3335 if (pwlen < 16) {
3336 bottom = 0; /* zero length passwords are OK! :-) */
3337 top = 15;
3338 } else {
3339 bottom = pwlen & ~7;
3340 top = bottom + 7;
3341 }
3342
3343 assert(pwlen >= bottom && pwlen <= top);
3344
3d88e64d 3345 randomstr = snewn(top + 1, char);
32874aea 3346
3347 for (i = bottom; i <= top; i++) {
9a10ecf4 3348 if (i == pwlen) {
51470298 3349 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3350 PKTT_PASSWORD, PKT_STR, s->password,
3351 PKTT_OTHER, PKT_END);
3352 } else {
32874aea 3353 for (j = 0; j < i; j++) {
3354 do {
3355 randomstr[j] = random_byte();
3356 } while (randomstr[j] == '\0');
3357 }
3358 randomstr[i] = '\0';
51470298 3359 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3360 PKT_STR, randomstr, PKT_END);
3361 }
3362 }
bd358db1 3363 logevent("Sending password with camouflage packets");
51470298 3364 ssh_pkt_defersend(ssh);
679539d7 3365 sfree(randomstr);
bd358db1 3366 }
51470298 3367 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3368 /*
3369 * The server can't deal with SSH1_MSG_IGNORE
3370 * but can deal with padded passwords, so we
3371 * can use the secondary defence.
3372 */
bd358db1 3373 char string[64];
51470298 3374 char *ss;
bd358db1 3375 int len;
3376
51470298 3377 len = strlen(s->password);
bd358db1 3378 if (len < sizeof(string)) {
51470298 3379 ss = string;
3380 strcpy(string, s->password);
bd358db1 3381 len++; /* cover the zero byte */
3382 while (len < sizeof(string)) {
3383 string[len++] = (char) random_byte();
3384 }
3385 } else {
51470298 3386 ss = s->password;
bd358db1 3387 }
3388 logevent("Sending length-padded password");
9a10ecf4 3389 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3390 PKT_INT, len, PKT_DATA, ss, len,
3391 PKTT_OTHER, PKT_END);
bd358db1 3392 } else {
3393 /*
3394 * The server has _both_
3395 * BUG_CHOKES_ON_SSH1_IGNORE and
3396 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3397 * therefore nothing we can do.
3398 */
3399 int len;
51470298 3400 len = strlen(s->password);
bd358db1 3401 logevent("Sending unpadded password");
9a10ecf4 3402 send_packet(ssh, s->pwpkt_type,
3403 PKTT_PASSWORD, PKT_INT, len,
3404 PKT_DATA, s->password, len,
3405 PKTT_OTHER, PKT_END);
32874aea 3406 }
3407 } else {
9a10ecf4 3408 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3409 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3410 }
3411 }
c5e9c988 3412 logevent("Sent password");
51470298 3413 memset(s->password, 0, strlen(s->password));
ff3187f6 3414 crWaitUntil(pktin);
3415 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3416 if (flags & FLAG_VERBOSE)
51470298 3417 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3418 logevent("Authentication refused");
ff3187f6 3419 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3420 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3421 crStop(0);
374330e2 3422 }
3423 }
3424
c5e9c988 3425 logevent("Authentication successful");
3426
fb09bf1c 3427 crFinish(1);
3428}
3429
32874aea 3430void sshfwd_close(struct ssh_channel *c)
3431{
51470298 3432 Ssh ssh = c->ssh;
3433
36f94d1f 3434 if (ssh->state != SSH_STATE_SESSION) {
3435 assert(ssh->state == SSH_STATE_CLOSED);
3436 return;
3437 }
3438
80e48603 3439 if (c && !c->closes) {
4ed34d25 3440 /*
3441 * If the channel's remoteid is -1, we have sent
3442 * CHANNEL_OPEN for this channel, but it hasn't even been
3443 * acknowledged by the server. So we must set a close flag
3444 * on it now, and then when the server acks the channel
3445 * open, we can close it then.
3446 */
36cac739 3447 if (((int)c->remoteid) != -1) {
51470298 3448 if (ssh->version == 1) {
3449 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3450 PKT_END);
3451 } else {
ff3187f6 3452 struct Packet *pktout;
3453 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3454 ssh2_pkt_adduint32(pktout, c->remoteid);
3455 ssh2_pkt_send(ssh, pktout);
4ed34d25 3456 }
32874aea 3457 }
0357890f 3458 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3459 if (c->type == CHAN_X11) {
3460 c->u.x11.s = NULL;
d74d141c 3461 logevent("Forwarded X11 connection terminated");
4ed34d25 3462 } else if (c->type == CHAN_SOCKDATA ||
3463 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3464 c->u.pfd.s = NULL;
3465 logevent("Forwarded port closed");
32874aea 3466 }
3467 }
3468}
3469
5471d09a 3470int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3471{
51470298 3472 Ssh ssh = c->ssh;
3473
36f94d1f 3474 if (ssh->state != SSH_STATE_SESSION) {
3475 assert(ssh->state == SSH_STATE_CLOSED);
3476 return 0;
3477 }
3478
51470298 3479 if (ssh->version == 1) {
3480 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3481 PKT_INT, c->remoteid,
9a10ecf4 3482 PKTT_DATA,
3483 PKT_INT, len, PKT_DATA, buf, len,
3484 PKTT_OTHER, PKT_END);
5471d09a 3485 /*
3486 * In SSH1 we can return 0 here - implying that forwarded
3487 * connections are never individually throttled - because
3488 * the only circumstance that can cause throttling will be
3489 * the whole SSH connection backing up, in which case
3490 * _everything_ will be throttled as a whole.
3491 */
3492 return 0;
783415f8 3493 } else {
32874aea 3494 ssh2_add_channel_data(c, buf, len);
5471d09a 3495 return ssh2_try_send(c);
3496 }
3497}
3498
3499void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3500{
51470298 3501 Ssh ssh = c->ssh;
3502
36f94d1f 3503 if (ssh->state != SSH_STATE_SESSION) {
3504 assert(ssh->state == SSH_STATE_CLOSED);
3505 return;
3506 }
3507
51470298 3508 if (ssh->version == 1) {
5471d09a 3509 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3510 c->v.v1.throttling = 0;
51470298 3511 ssh1_throttle(ssh, -1);
5471d09a 3512 }
3513 } else {
3514 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3515 }
9c964e85 3516}
3517
51df0ab5 3518static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
3519{
3520 char *string;
3521 int stringlen, bufsize;
3522
3523 ssh_pkt_getstring(pktin, &string, &stringlen);
3524 if (string == NULL) {
3525 bombout(("Incoming terminal data packet was badly formed"));
3526 return;
3527 }
3528
3529 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
3530 string, stringlen);
3531 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3532 ssh->v1_stdout_throttling = 1;
3533 ssh1_throttle(ssh, +1);
3534 }
3535}
3536
3537static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
3538{
3539 /* Remote side is trying to open a channel to talk to our
3540 * X-Server. Give them back a local channel number. */
3541 struct ssh_channel *c;
3542 int remoteid = ssh_pkt_getuint32(pktin);
3543
3544 logevent("Received X11 connect request");
3545 /* Refuse if X11 forwarding is disabled. */
3546 if (!ssh->X11_fwd_enabled) {
3547 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3548 PKT_INT, remoteid, PKT_END);
3549 logevent("Rejected X11 connect request");
3550 } else {
3551 c = snew(struct ssh_channel);
3552 c->ssh = ssh;
3553
3554 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3555 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3556 logevent("Opening X11 forward connection failed");
3557 sfree(c);
3558 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3559 PKT_INT, remoteid, PKT_END);
3560 } else {
3561 logevent
3562 ("Opening X11 forward connection succeeded");
3563 c->remoteid = remoteid;
3564 c->localid = alloc_channel_id(ssh);
3565 c->closes = 0;
3566 c->v.v1.throttling = 0;
3567 c->type = CHAN_X11; /* identify channel type */
3568 add234(ssh->channels, c);
3569 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3570 PKT_INT, c->remoteid, PKT_INT,
3571 c->localid, PKT_END);
3572 logevent("Opened X11 forward channel");
3573 }
3574 }
3575}
3576
3577static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
3578{
3579 /* Remote side is trying to open a channel to talk to our
3580 * agent. Give them back a local channel number. */
3581 struct ssh_channel *c;
3582 int remoteid = ssh_pkt_getuint32(pktin);
3583
3584 /* Refuse if agent forwarding is disabled. */
3585 if (!ssh->agentfwd_enabled) {
3586 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3587 PKT_INT, remoteid, PKT_END);
3588 } else {
3589 c = snew(struct ssh_channel);
3590 c->ssh = ssh;
3591 c->remoteid = remoteid;
3592 c->localid = alloc_channel_id(ssh);
3593 c->closes = 0;
3594 c->v.v1.throttling = 0;
3595 c->type = CHAN_AGENT; /* identify channel type */
3596 c->u.a.lensofar = 0;
3597 add234(ssh->channels, c);
3598 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3599 PKT_INT, c->remoteid, PKT_INT, c->localid,
3600 PKT_END);
3601 }
3602}
3603
3604static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
3605{
3606 /* Remote side is trying to open a channel to talk to a
3607 * forwarded port. Give them back a local channel number. */
3608 struct ssh_channel *c;
3609 struct ssh_rportfwd pf;
3610 int remoteid;
3611 int hostsize, port;
3612 char *host, buf[1024];
3613 const char *e;
3614 c = snew(struct ssh_channel);
3615 c->ssh = ssh;
3616
3617 remoteid = ssh_pkt_getuint32(pktin);
3618 ssh_pkt_getstring(pktin, &host, &hostsize);
3619 port = ssh_pkt_getuint32(pktin);
3620
3621 if (hostsize >= lenof(pf.dhost))
3622 hostsize = lenof(pf.dhost)-1;
3623 memcpy(pf.dhost, host, hostsize);
3624 pf.dhost[hostsize] = '\0';
3625 pf.dport = port;
3626
3627 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3628 sprintf(buf, "Rejected remote port open request for %s:%d",
3629 pf.dhost, port);
3630 logevent(buf);
3631 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3632 PKT_INT, remoteid, PKT_END);
3633 } else {
3634 sprintf(buf, "Received remote port open request for %s:%d",
3635 pf.dhost, port);
3636 logevent(buf);
3637 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3638 c, &ssh->cfg);
3639 if (e != NULL) {
3640 char buf[256];
3641 sprintf(buf, "Port open failed: %s", e);
3642 logevent(buf);
3643 sfree(c);
3644 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3645 PKT_INT, remoteid, PKT_END);
3646 } else {
3647 c->remoteid = remoteid;
3648 c->localid = alloc_channel_id(ssh);
3649 c->closes = 0;
3650 c->v.v1.throttling = 0;
3651 c->type = CHAN_SOCKDATA; /* identify channel type */
3652 add234(ssh->channels, c);
3653 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3654 PKT_INT, c->remoteid, PKT_INT,
3655 c->localid, PKT_END);
3656 logevent("Forwarded port opened successfully");
3657 }
3658 }
3659}
3660
3661static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
3662{
3663 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3664 unsigned int localid = ssh_pkt_getuint32(pktin);
3665 struct ssh_channel *c;
3666
3667 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3668 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3669 c->remoteid = localid;
3670 c->type = CHAN_SOCKDATA;
3671 c->v.v1.throttling = 0;
3672 pfd_confirm(c->u.pfd.s);
3673 }
3674
3675 if (c && c->closes) {
3676 /*
3677 * We have a pending close on this channel,
3678 * which we decided on before the server acked
3679 * the channel open. So now we know the
3680 * remoteid, we can close it again.
3681 */
3682 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3683 PKT_INT, c->remoteid, PKT_END);
3684 }
3685}
3686
3687static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
3688{
3689 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3690 struct ssh_channel *c;
3691
3692 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3693 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3694 logevent("Forwarded connection refused by server");
3695 pfd_close(c->u.pfd.s);
3696 del234(ssh->channels, c);
3697 sfree(c);
3698 }
3699}
3700
3701static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
3702{
3703 /* Remote side closes a channel. */
3704 unsigned i = ssh_pkt_getuint32(pktin);
3705 struct ssh_channel *c;
3706 c = find234(ssh->channels, &i, ssh_channelfind);
3707 if (c && ((int)c->remoteid) != -1) {
3708 int closetype;
3709 closetype =
3710 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3711
3712 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3713 logevent("Forwarded X11 connection terminated");
3714 assert(c->u.x11.s != NULL);
3715 x11_close(c->u.x11.s);
3716 c->u.x11.s = NULL;
3717 }
3718 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3719 logevent("Forwarded port closed");
3720 assert(c->u.pfd.s != NULL);
3721 pfd_close(c->u.pfd.s);
3722 c->u.pfd.s = NULL;
3723 }
3724
3725 c->closes |= (closetype << 2); /* seen this message */
3726 if (!(c->closes & closetype)) {
3727 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
3728 PKT_END);
3729 c->closes |= closetype; /* sent it too */
3730 }
3731
3732 if (c->closes == 15) {
3733 del234(ssh->channels, c);
3734 sfree(c);
3735 }
3736 } else {
3737 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3738 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3739 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3740 i));
3741 }
3742}
3743
3744static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
3745{
3746 /* Data sent down one of our channels. */
3747 int i = ssh_pkt_getuint32(pktin);
3748 char *p;
3749 int len;
3750 struct ssh_channel *c;
3751
3752 ssh_pkt_getstring(pktin, &p, &len);
3753
3754 c = find234(ssh->channels, &i, ssh_channelfind);
3755 if (c) {
3756 int bufsize = 0;
3757 switch (c->type) {
3758 case CHAN_X11:
3759 bufsize = x11_send(c->u.x11.s, p, len);
3760 break;
3761 case CHAN_SOCKDATA:
3762 bufsize = pfd_send(c->u.pfd.s, p, len);
3763 break;
3764 case CHAN_AGENT:
3765 /* Data for an agent message. Buffer it. */
3766 while (len > 0) {
3767 if (c->u.a.lensofar < 4) {
3768 int l = min(4 - c->u.a.lensofar, len);
3769 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3770 l);
3771 p += l;
3772 len -= l;
3773 c->u.a.lensofar += l;
3774 }
3775 if (c->u.a.lensofar == 4) {
3776 c->u.a.totallen =
3777 4 + GET_32BIT(c->u.a.msglen);
3778 c->u.a.message = snewn(c->u.a.totallen,
3779 unsigned char);
3780 memcpy(c->u.a.message, c->u.a.msglen, 4);
3781 }
3782 if (c->u.a.lensofar >= 4 && len > 0) {
3783 int l =
3784 min(c->u.a.totallen - c->u.a.lensofar,
3785 len);
3786 memcpy(c->u.a.message + c->u.a.lensofar, p,
3787 l);
3788 p += l;
3789 len -= l;
3790 c->u.a.lensofar += l;
3791 }
3792 if (c->u.a.lensofar == c->u.a.totallen) {
3793 void *reply;
3794 int replylen;
3795 if (agent_query(c->u.a.message,
3796 c->u.a.totallen,
3797 &reply, &replylen,
3798 ssh_agentf_callback, c))
3799 ssh_agentf_callback(c, reply, replylen);
3800 sfree(c->u.a.message);
3801 c->u.a.lensofar = 0;
3802 }
3803 }
3804 bufsize = 0; /* agent channels never back up */
3805 break;
3806 }
3807 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3808 c->v.v1.throttling = 1;
3809 ssh1_throttle(ssh, +1);
3810 }
3811 }
3812}
3813
3814static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
3815{
3816 char buf[100];
3817 ssh->exitcode = ssh_pkt_getuint32(pktin);
3818 sprintf(buf, "Server sent command exit status %d",
3819 ssh->exitcode);
3820 logevent(buf);
3821 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3822 /*
3823 * In case `helpful' firewalls or proxies tack
3824 * extra human-readable text on the end of the
3825 * session which we might mistake for another
3826 * encrypted packet, we close the session once
3827 * we've sent EXIT_CONFIRMATION.
3828 */
3829 ssh_closing((Plug)ssh, NULL, 0, 0);
3830}
3831
b09eaa88 3832static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
3833 struct Packet *pktin)
32874aea 3834{
b09eaa88 3835 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 3836
51df0ab5 3837 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
3838 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
3839 ssh1_smsg_stdout_stderr_data;
3840
3841 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
3842 ssh1_msg_channel_open_confirmation;
3843 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
3844 ssh1_msg_channel_open_failure;
3845 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
3846 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
3847 ssh1_msg_channel_close;
3848 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
3849 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
3850
86916870 3851 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 3852 logevent("Requesting agent forwarding");
51470298 3853 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3854 do {
3855 crReturnV;
ff3187f6 3856 } while (!pktin);
3857 if (pktin->type != SSH1_SMSG_SUCCESS
3858 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3859 bombout(("Protocol confusion"));
7ffdbc1a 3860 crStopV;
ff3187f6 3861 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3862 logevent("Agent forwarding refused");
3863 } else {
3864 logevent("Agent forwarding enabled");
51470298 3865 ssh->agentfwd_enabled = TRUE;
51df0ab5 3866 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 3867 }
dacbd0e8 3868 }
3869
86916870 3870 if (ssh->cfg.x11_forward) {
32874aea 3871 char proto[20], data[64];
3872 logevent("Requesting X11 forwarding");
302121de 3873 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 3874 data, sizeof(data), ssh->cfg.x11_auth);
3875 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 3876 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3877 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3878 PKT_STR, proto, PKT_STR, data,
86916870 3879 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 3880 PKT_END);
32874aea 3881 } else {
51470298 3882 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3883 PKT_STR, proto, PKT_STR, data, PKT_END);
3884 }
3885 do {
3886 crReturnV;
ff3187f6 3887 } while (!pktin);
3888 if (pktin->type != SSH1_SMSG_SUCCESS
3889 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3890 bombout(("Protocol confusion"));
7ffdbc1a 3891 crStopV;
ff3187f6 3892 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3893 logevent("X11 forwarding refused");
3894 } else {
3895 logevent("X11 forwarding enabled");
51470298 3896 ssh->X11_fwd_enabled = TRUE;
51df0ab5 3897 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 3898 }
3899 }
3900
d74d141c 3901 {
9bf696b1 3902 char type;
d74d141c 3903 int n;
a4fc0d74 3904 int sport,dport,sserv,dserv;
6ee9b735 3905 char sports[256], dports[256], saddr[256], host[256];
d74d141c 3906
51470298 3907 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3908 /* Add port forwardings. */
86916870 3909 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 3910 while (*ssh->portfwd_strptr) {
3911 type = *ssh->portfwd_strptr++;
6ee9b735 3912 saddr[0] = '\0';
d74d141c 3913 n = 0;
6ee9b735 3914 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3915 if (*ssh->portfwd_strptr == ':') {
3916 /*
3917 * We've seen a colon in the middle of the
3918 * source port number. This means that
3919 * everything we've seen until now is the
3920 * source _address_, so we'll move it into
3921 * saddr and start sports from the beginning
3922 * again.
3923 */
3924 ssh->portfwd_strptr++;
3925 sports[n] = '\0';
3926 strcpy(saddr, sports);
3927 n = 0;
3928 }
3929 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3930 }
d74d141c 3931 sports[n] = 0;
820ebe3b 3932 if (type != 'D') {
3933 if (*ssh->portfwd_strptr == '\t')
3934 ssh->portfwd_strptr++;
3935 n = 0;
3936 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3937 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3938 }
3939 host[n] = 0;
3940 if (*ssh->portfwd_strptr == ':')
3941 ssh->portfwd_strptr++;
3942 n = 0;
3943 while (*ssh->portfwd_strptr) {
3944 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3945 }
3946 dports[n] = 0;
51470298 3947 ssh->portfwd_strptr++;
820ebe3b 3948 dport = atoi(dports);
3949 dserv = 0;
3950 if (dport == 0) {
3951 dserv = 1;
3952 dport = net_service_lookup(dports);
3953 if (!dport) {
3954 logeventf(ssh, "Service lookup failed for"
3955 " destination port \"%s\"", dports);
3956 }
a4fc0d74 3957 }
820ebe3b 3958 } else {
3959 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 3960 dport = dserv = -1;
7d5b0f4d 3961 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 3962 }
d74d141c 3963 sport = atoi(sports);
a4fc0d74 3964 sserv = 0;
3965 if (sport == 0) {
3966 sserv = 1;
68a49acb 3967 sport = net_service_lookup(sports);
3968 if (!sport) {
57356d63 3969 logeventf(ssh, "Service lookup failed for source"
3970 " port \"%s\"", sports);
a4fc0d74 3971 }
3972 }
d74d141c 3973 if (sport && dport) {
94ab1ddf 3974 /* Set up a description of the source port. */
c61c9cdf 3975 static char *sportdesc;
3976 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
94ab1ddf 3977 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3978 (int)(*saddr?1:0), ":",
3979 (int)(sserv ? strlen(sports) : 0), sports,
3980 sserv, "(", sport, sserv, ")");
d74d141c 3981 if (type == 'L') {
94ab1ddf 3982 /* Verbose description of the destination port */
3983 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3984 host,
3985 (int)(dserv ? strlen(dports) : 0), dports,
3986 dserv, "(", dport, dserv, ")");
3987 const char *err = pfd_addforward(host, dport,
3988 *saddr ? saddr : NULL,
3989 sport, ssh, &ssh->cfg);
3990 if (err) {
3991 logeventf(ssh, "Local port %s forward to %s"
3992 " failed: %s", sportdesc, dportdesc, err);
3993 } else {
3994 logeventf(ssh, "Local port %s forwarding to %s",
3995 sportdesc, dportdesc);
3996 }
3997 sfree(dportdesc);
820ebe3b 3998 } else if (type == 'D') {
94ab1ddf 3999 const char *err = pfd_addforward(NULL, -1,
4000 *saddr ? saddr : NULL,
4001 sport, ssh, &ssh->cfg);
4002 if (err) {
4003 logeventf(ssh, "Local port %s SOCKS dynamic forward"
4004 " setup failed: %s", sportdesc, err);
4005 } else {
4006 logeventf(ssh, "Local port %s doing SOCKS"
4007 " dynamic forwarding", sportdesc);
4008 }
d74d141c 4009 } else {
4010 struct ssh_rportfwd *pf;
3d88e64d 4011 pf = snew(struct ssh_rportfwd);
bc240b21 4012 strcpy(pf->dhost, host);
4013 pf->dport = dport;
0cd494d7 4014 if (*saddr) {
6ee9b735 4015 logeventf(ssh,
4016 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
4017 saddr, sport);
4018 }
51470298 4019 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 4020 logeventf(ssh,
4021 "Duplicate remote port forwarding to %s:%d",
4022 host, dport);
bc240b21 4023 sfree(pf);
d74d141c 4024 } else {
57356d63 4025 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
4026 " forward to %s:%.*s%.*s%d%.*s",
4027 (int)(sserv ? strlen(sports) : 0), sports,
4028 sserv, "(", sport, sserv, ")",
4029 host,
4030 (int)(dserv ? strlen(dports) : 0), dports,
4031 dserv, "(", dport, dserv, ")");
51470298 4032 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 4033 PKT_INT, sport,
4034 PKT_STR, host,
4035 PKT_INT, dport,
4036 PKT_END);
9bf696b1 4037 do {
4038 crReturnV;
ff3187f6 4039 } while (!pktin);
4040 if (pktin->type != SSH1_SMSG_SUCCESS
4041 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4042 bombout(("Protocol confusion"));
7ffdbc1a 4043 crStopV;
ff3187f6 4044 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4045 c_write_str(ssh, "Server refused port"
4046 " forwarding\r\n");
51df0ab5 4047 logevent("Server refused this port forwarding");
4048 } else {
4049 logevent("Remote port forwarding enabled");
4050 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] =
4051 ssh1_msg_port_open;
9bf696b1 4052 }
d74d141c 4053 }
4054 }
94ab1ddf 4055 sfree(sportdesc);
d74d141c 4056 }
4057 }
4058 }
4059
86916870 4060 if (!ssh->cfg.nopty) {
a5dd8467 4061 /* Unpick the terminal-speed string. */
4062 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4063 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4064 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4065 /* Send the pty request. */
51470298 4066 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4067 PKT_STR, ssh->cfg.termtype,
51470298 4068 PKT_INT, ssh->term_height,
4069 PKT_INT, ssh->term_width,
a5dd8467 4070 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4071 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4072 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4073 PKT_CHAR, 0, PKT_END);
51470298 4074 ssh->state = SSH_STATE_INTERMED;
32874aea 4075 do {
4076 crReturnV;
ff3187f6 4077 } while (!pktin);
4078 if (pktin->type != SSH1_SMSG_SUCCESS
4079 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4080 bombout(("Protocol confusion"));
7ffdbc1a 4081 crStopV;
ff3187f6 4082 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4083 c_write_str(ssh, "Server refused to allocate pty\r\n");
4084 ssh->editing = ssh->echoing = 1;
32874aea 4085 }
a5dd8467 4086 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4087 ssh->ospeed, ssh->ispeed);
0965bee0 4088 } else {
51470298 4089 ssh->editing = ssh->echoing = 1;
374330e2 4090 }
4091
86916870 4092 if (ssh->cfg.compression) {
51470298 4093 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4094 do {
4095 crReturnV;
ff3187f6 4096 } while (!pktin);
4097 if (pktin->type != SSH1_SMSG_SUCCESS
4098 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4099 bombout(("Protocol confusion"));
7ffdbc1a 4100 crStopV;
ff3187f6 4101 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4102 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4103 }
4ba9b64b 4104 logevent("Started compression");
51470298 4105 ssh->v1_compressing = TRUE;
5366aed8 4106 ssh->cs_comp_ctx = zlib_compress_init();
4107 logevent("Initialised zlib (RFC1950) compression");
4108 ssh->sc_comp_ctx = zlib_decompress_init();
4109 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4110 }
4111
fd5e5847 4112 /*
4113 * Start the shell or command.
4114 *
4115 * Special case: if the first-choice command is an SSH2
4116 * subsystem (hence not usable here) and the second choice
4117 * exists, we fall straight back to that.
4118 */
4119 {
86916870 4120 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 4121
86916870 4122 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4123 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4124 ssh->fallback_cmd = TRUE;
fd5e5847 4125 }
4126 if (*cmd)
51470298 4127 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4128 else
51470298 4129 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4130 logevent("Started session");
4131 }
374330e2 4132
51470298 4133 ssh->state = SSH_STATE_SESSION;
4134 if (ssh->size_needed)
4135 ssh_size(ssh, ssh->term_width, ssh->term_height);
4136 if (ssh->eof_needed)
4137 ssh_special(ssh, TS_EOF);
374330e2 4138
b9d7bcad 4139 if (ssh->ldisc)
4140 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4141 ssh->send_ok = 1;
4142 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4143 while (1) {
d74d141c 4144
51df0ab5 4145 /*
4146 * By this point, most incoming packets are already being
4147 * handled by the dispatch table, and we need only pay
4148 * attention to the unusual ones.
4149 */
0357890f 4150
51df0ab5 4151 crReturnV;
4152 if (pktin) {
4153 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4154 /* may be from EXEC_SHELL on some servers */
ff3187f6 4155 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4156 /* may be from EXEC_SHELL on some servers
374330e2 4157 * if no pty is available or in other odd cases. Ignore */
374330e2 4158 } else {
ff3187f6 4159 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4160 crStopV;
374330e2 4161 }
4162 } else {
8df7a775 4163 while (inlen > 0) {
4164 int len = min(inlen, 512);
9a10ecf4 4165 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4166 PKT_INT, len, PKT_DATA, in, len,
4167 PKTT_OTHER, PKT_END);
8df7a775 4168 in += len;
4169 inlen -= len;
4170 }
374330e2 4171 }
4172 }
4173
4174 crFinishV;
4175}
4176
4177/*
b09eaa88 4178 * Handle the top-level SSH2 protocol.
4179 */
4180static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4181{
4182 char *buf, *msg;
4183 int msglen;
4184
4185 ssh_pkt_getstring(pktin, &msg, &msglen);
4186 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4187 logevent(buf);
4188 sfree(buf);
4189}
4190
4191static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4192{
4193 /* log reason code in disconnect message */
4194 char *msg;
4195 int msglen;
4196
4197 ssh_pkt_getstring(pktin, &msg, &msglen);
4198 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4199}
4200
4201void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4202{
4203 /* Do nothing, because we're ignoring it! Duhh. */
4204}
4205
4206static void ssh1_protocol_setup(Ssh ssh)
4207{
4208 int i;
4209
4210 /*
4211 * Most messages are handled by the coroutines.
4212 */
4213 for (i = 0; i < 256; i++)
4214 ssh->packet_dispatch[i] = NULL;
4215
4216 /*
4217 * These special message types we install handlers for.
4218 */
4219 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4220 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4221 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4222}
4223
4224static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4225 struct Packet *pktin)
4226{
4227 if (ssh->state == SSH_STATE_CLOSED)
4228 return;
4229
4230 if (pktin && ssh->packet_dispatch[pktin->type]) {
4231 ssh->packet_dispatch[pktin->type](ssh, pktin);
4232 return;
4233 }
4234
4235 if (!ssh->protocol_initial_phase_done) {
4236 if (do_ssh1_login(ssh, in, inlen, pktin))
4237 ssh->protocol_initial_phase_done = TRUE;
4238 else
4239 return;
4240 }
4241
4242 do_ssh1_connection(ssh, in, inlen, pktin);
4243}
4244
4245/*
e5574168 4246 * Utility routine for decoding comma-separated strings in KEXINIT.
4247 */
32874aea 4248static int in_commasep_string(char *needle, char *haystack, int haylen)
4249{
57356d63 4250 int needlen;
4251 if (!needle || !haystack) /* protect against null pointers */
4252 return 0;
4253 needlen = strlen(needle);
e5574168 4254 while (1) {
32874aea 4255 /*
4256 * Is it at the start of the string?
4257 */
4258 if (haylen >= needlen && /* haystack is long enough */
4259 !memcmp(needle, haystack, needlen) && /* initial match */
4260 (haylen == needlen || haystack[needlen] == ',')
4261 /* either , or EOS follows */
4262 )
4263 return 1;
4264 /*
4265 * If not, search for the next comma and resume after that.
4266 * If no comma found, terminate.
4267 */
4268 while (haylen > 0 && *haystack != ',')
4269 haylen--, haystack++;
4270 if (haylen == 0)
4271 return 0;
4272 haylen--, haystack++; /* skip over comma itself */
e5574168 4273 }
4274}
4275
4276/*
d39f364a 4277 * SSH2 key creation method.
4278 */
d8baa528 4279static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4280 unsigned char *sessid, char chr,
4281 unsigned char *keyspace)
32874aea 4282{
d39f364a 4283 SHA_State s;
4284 /* First 20 bytes. */
4285 SHA_Init(&s);
51470298 4286 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4287 sha_mpint(&s, K);
d39f364a 4288 SHA_Bytes(&s, H, 20);
4289 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4290 SHA_Bytes(&s, sessid, 20);
d39f364a 4291 SHA_Final(&s, keyspace);
4292 /* Next 20 bytes. */
4293 SHA_Init(&s);
51470298 4294 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4295 sha_mpint(&s, K);
d39f364a 4296 SHA_Bytes(&s, H, 20);
4297 SHA_Bytes(&s, keyspace, 20);
32874aea 4298 SHA_Final(&s, keyspace + 20);
d39f364a 4299}
4300
4301/*
7cca0d81 4302 * Handle the SSH2 transport layer.
e5574168 4303 */
ff3187f6 4304static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4305 struct Packet *pktin)
e5574168 4306{
51470298 4307 struct do_ssh2_transport_state {
4308 int nbits, pbits, warn;
4309 Bignum p, g, e, f, K;
4310 int kex_init_value, kex_reply_value;
4311 const struct ssh_mac **maclist;
4312 int nmacs;
4313 const struct ssh2_cipher *cscipher_tobe;
4314 const struct ssh2_cipher *sccipher_tobe;
4315 const struct ssh_mac *csmac_tobe;
4316 const struct ssh_mac *scmac_tobe;
4317 const struct ssh_compress *cscomp_tobe;
4318 const struct ssh_compress *sccomp_tobe;
4319 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4320 int hostkeylen, siglen;
4321 void *hkey; /* actual host key */
4322 unsigned char exchange_hash[20];
4323 int n_preferred_ciphers;
4324 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4325 const struct ssh_compress *preferred_comp;
4326 int first_kex;
ff3187f6 4327 struct Packet *pktout;
51470298 4328 };
4329 crState(do_ssh2_transport_state);
4330
4331 crBegin(ssh->do_ssh2_transport_crstate);
4332
4333 s->cscipher_tobe = s->sccipher_tobe = NULL;
4334 s->csmac_tobe = s->scmac_tobe = NULL;
4335 s->cscomp_tobe = s->sccomp_tobe = NULL;
4336
51470298 4337 s->first_kex = 1;
e5574168 4338
51470298 4339 {
4340 int i;
4341 /*
4342 * Set up the preferred ciphers. (NULL => warn below here)
4343 */
4344 s->n_preferred_ciphers = 0;
4345 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4346 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4347 case CIPHER_BLOWFISH:
4348 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4349 break;
4350 case CIPHER_DES:
86916870 4351 if (ssh->cfg.ssh2_des_cbc) {
51470298 4352 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4353 }
4354 break;
4355 case CIPHER_3DES:
4356 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4357 break;
4358 case CIPHER_AES:
4359 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4360 break;
4361 case CIPHER_WARN:
4362 /* Flag for later. Don't bother if it's the last in
4363 * the list. */
4364 if (i < CIPHER_MAX - 1) {
4365 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4366 }
4367 break;
ca20bfcf 4368 }
ca20bfcf 4369 }
5e8358ad 4370 }
ca20bfcf 4371
4372 /*
4373 * Set up preferred compression.
4374 */
86916870 4375 if (ssh->cfg.compression)
51470298 4376 s->preferred_comp = &ssh_zlib;
4ba9b64b 4377 else
51470298 4378 s->preferred_comp = &ssh_comp_none;
5e8358ad 4379
7591b9ff 4380 /*
4381 * Be prepared to work around the buggy MAC problem.
4382 */
51470298 4383 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4384 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 4385 else
51470298 4386 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 4387
32874aea 4388 begin_key_exchange:
51470298 4389 {
4390 int i, j, cipherstr_started;
4391
4392 /*
590f6a5f 4393 * Enable queueing of outgoing auth- or connection-layer
4394 * packets while we are in the middle of a key exchange.
4395 */
4396 ssh->queueing = TRUE;
4397
4398 /*
9442dd57 4399 * Flag that KEX is in progress.
4400 */
4401 ssh->kex_in_progress = TRUE;
4402
4403 /*
51470298 4404 * Construct and send our key exchange packet.
4405 */
ff3187f6 4406 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4407 for (i = 0; i < 16; i++)
ff3187f6 4408 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4409 /* List key exchange algorithms. */
ff3187f6 4410 ssh2_pkt_addstring_start(s->pktout);
51470298 4411 for (i = 0; i < lenof(kex_algs); i++) {
4412 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4413 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4414 continue;
ff3187f6 4415 ssh2_pkt_addstring_str(s->pktout, kex_algs[i]->name);
51470298 4416 if (i < lenof(kex_algs) - 1)
ff3187f6 4417 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4418 }
51470298 4419 /* List server host key algorithms. */
ff3187f6 4420 ssh2_pkt_addstring_start(s->pktout);
51470298 4421 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4422 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4423 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4424 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4425 }
51470298 4426 /* List client->server encryption algorithms. */
ff3187f6 4427 ssh2_pkt_addstring_start(s->pktout);
51470298 4428 cipherstr_started = 0;
4429 for (i = 0; i < s->n_preferred_ciphers; i++) {
4430 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4431 if (!c) continue; /* warning flag */
4432 for (j = 0; j < c->nciphers; j++) {
4433 if (cipherstr_started)
ff3187f6 4434 ssh2_pkt_addstring_str(s->pktout, ",");
4435 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
51470298 4436 cipherstr_started = 1;
4437 }
4438 }
4439 /* List server->client encryption algorithms. */
ff3187f6 4440 ssh2_pkt_addstring_start(s->pktout);
51470298 4441 cipherstr_started = 0;
4442 for (i = 0; i < s->n_preferred_ciphers; i++) {
4443 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4444 if (!c) continue; /* warning flag */
4445 for (j = 0; j < c->nciphers; j++) {
4446 if (cipherstr_started)
ff3187f6 4447 ssh2_pkt_addstring_str(s->pktout, ",");
4448 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
51470298 4449 cipherstr_started = 1;
4450 }
4451 }
4452 /* List client->server MAC algorithms. */
ff3187f6 4453 ssh2_pkt_addstring_start(s->pktout);
51470298 4454 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4455 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4456 if (i < s->nmacs - 1)
ff3187f6 4457 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4458 }
4459 /* List server->client MAC algorithms. */
ff3187f6 4460 ssh2_pkt_addstring_start(s->pktout);
51470298 4461 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4462 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4463 if (i < s->nmacs - 1)
ff3187f6 4464 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4465 }
4466 /* List client->server compression algorithms. */
ff3187f6 4467 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4468 assert(lenof(compressions) > 1);
ff3187f6 4469 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4470 for (i = 0; i < lenof(compressions); i++) {
4471 const struct ssh_compress *c = compressions[i];
4472 if (c != s->preferred_comp) {
ff3187f6 4473 ssh2_pkt_addstring_str(s->pktout, ",");
4474 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4475 }
51470298 4476 }
4477 /* List server->client compression algorithms. */
ff3187f6 4478 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4479 assert(lenof(compressions) > 1);
ff3187f6 4480 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4481 for (i = 0; i < lenof(compressions); i++) {
4482 const struct ssh_compress *c = compressions[i];
4483 if (c != s->preferred_comp) {
ff3187f6 4484 ssh2_pkt_addstring_str(s->pktout, ",");
4485 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4486 }
51470298 4487 }
4488 /* List client->server languages. Empty list. */
ff3187f6 4489 ssh2_pkt_addstring_start(s->pktout);
51470298 4490 /* List server->client languages. Empty list. */
ff3187f6 4491 ssh2_pkt_addstring_start(s->pktout);
51470298 4492 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4493 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4494 /* Reserved. */
ff3187f6 4495 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4496 }
0db56f73 4497
51470298 4498 ssh->exhash = ssh->exhashbase;
ff3187f6 4499 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4500
590f6a5f 4501 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4502
ff3187f6 4503 if (!pktin)
4504 crWaitUntil(pktin);
4505 if (pktin->length > 5)
4506 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4507
4508 /*
4509 * Now examine the other side's KEXINIT to see what we're up
4510 * to.
4511 */
51470298 4512 {
4513 char *str;
4514 int i, j, len;
4515
ff3187f6 4516 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4517 bombout(("expected key exchange packet from server"));
7ffdbc1a 4518 crStop(0);
32874aea 4519 }
51470298 4520 ssh->kex = NULL;
4521 ssh->hostkey = NULL;
4522 s->cscipher_tobe = NULL;
4523 s->sccipher_tobe = NULL;
4524 s->csmac_tobe = NULL;
4525 s->scmac_tobe = NULL;
4526 s->cscomp_tobe = NULL;
4527 s->sccomp_tobe = NULL;
ff3187f6 4528 pktin->savedpos += 16; /* skip garbage cookie */
4529 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
51470298 4530 for (i = 0; i < lenof(kex_algs); i++) {
4531 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4532 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4533 continue;
4534 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4535 ssh->kex = kex_algs[i];
4536 break;
4537 }
32874aea 4538 }
ff3187f6 4539 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4540 for (i = 0; i < lenof(hostkey_algs); i++) {
4541 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4542 ssh->hostkey = hostkey_algs[i];
4543 break;
4544 }
4545 }
ff3187f6 4546 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4547 s->warn = 0;
4548 for (i = 0; i < s->n_preferred_ciphers; i++) {
4549 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4550 if (!c) {
4551 s->warn = 1;
4552 } else {
4553 for (j = 0; j < c->nciphers; j++) {
4554 if (in_commasep_string(c->list[j]->name, str, len)) {
4555 s->cscipher_tobe = c->list[j];
4556 break;
4557 }
ca20bfcf 4558 }
32874aea 4559 }
51470298 4560 if (s->cscipher_tobe) {
4561 if (s->warn)
a8327734 4562 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 4563 break;
4564 }
32874aea 4565 }
51470298 4566 if (!s->cscipher_tobe) {
6b5cf8b4 4567 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4568 str ? str : "(null)"));
7ffdbc1a 4569 crStop(0);
ca20bfcf 4570 }
0ef8f407 4571
ff3187f6 4572 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4573 s->warn = 0;
4574 for (i = 0; i < s->n_preferred_ciphers; i++) {
4575 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4576 if (!c) {
4577 s->warn = 1;
4578 } else {
4579 for (j = 0; j < c->nciphers; j++) {
4580 if (in_commasep_string(c->list[j]->name, str, len)) {
4581 s->sccipher_tobe = c->list[j];
4582 break;
4583 }
ca20bfcf 4584 }
32874aea 4585 }
51470298 4586 if (s->sccipher_tobe) {
4587 if (s->warn)
a8327734 4588 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 4589 break;
4590 }
32874aea 4591 }
51470298 4592 if (!s->sccipher_tobe) {
6b5cf8b4 4593 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4594 str ? str : "(null)"));
7ffdbc1a 4595 crStop(0);
ca20bfcf 4596 }
0ef8f407 4597
ff3187f6 4598 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 4599 for (i = 0; i < s->nmacs; i++) {
4600 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4601 s->csmac_tobe = s->maclist[i];
4602 break;
4603 }
32874aea 4604 }
ff3187f6 4605 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 4606 for (i = 0; i < s->nmacs; i++) {
4607 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4608 s->scmac_tobe = s->maclist[i];
4609 break;
4610 }
32874aea 4611 }
ff3187f6 4612 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 4613 for (i = 0; i < lenof(compressions) + 1; i++) {
4614 const struct ssh_compress *c =
4615 i == 0 ? s->preferred_comp : compressions[i - 1];
4616 if (in_commasep_string(c->name, str, len)) {
4617 s->cscomp_tobe = c;
4618 break;
4619 }
32874aea 4620 }
ff3187f6 4621 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 4622 for (i = 0; i < lenof(compressions) + 1; i++) {
4623 const struct ssh_compress *c =
4624 i == 0 ? s->preferred_comp : compressions[i - 1];
4625 if (in_commasep_string(c->name, str, len)) {
4626 s->sccomp_tobe = c;
4627 break;
4628 }
32874aea 4629 }
e5574168 4630 }
e5574168 4631
4632 /*
7bd5a860 4633 * Work out the number of bits of key we will need from the key
4634 * exchange. We start with the maximum key length of either
4635 * cipher...
4636 */
4637 {
32874aea 4638 int csbits, scbits;
7bd5a860 4639
51470298 4640 csbits = s->cscipher_tobe->keylen;
4641 scbits = s->sccipher_tobe->keylen;
4642 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 4643 }
4644 /* The keys only have 160-bit entropy, since they're based on
4645 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 4646 if (s->nbits > 160)
4647 s->nbits = 160;
7bd5a860 4648
4649 /*
a92dd380 4650 * If we're doing Diffie-Hellman group exchange, start by
4651 * requesting a group.
e5574168 4652 */
51470298 4653 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 4654 logevent("Doing Diffie-Hellman group exchange");
51470298 4655 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 4656 /*
4657 * Work out how big a DH group we will need to allow that
4658 * much data.
7bd5a860 4659 */
51470298 4660 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 4661 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
4662 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 4663 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 4664
ff3187f6 4665 crWaitUntil(pktin);
4666 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 4667 bombout(("expected key exchange group packet from server"));
7ffdbc1a 4668 crStop(0);
32874aea 4669 }
ff3187f6 4670 s->p = ssh2_pkt_getmp(pktin);
4671 s->g = ssh2_pkt_getmp(pktin);
4672 if (!s->p || !s->g) {
4673 bombout(("unable to read mp-ints from incoming group packet"));
4674 crStop(0);
4675 }
27cd7fc2 4676 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 4677 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4678 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 4679 } else {
51470298 4680 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 4681 ssh->kex_ctx = dh_setup_group1();
51470298 4682 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4683 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 4684 }
e5574168 4685
a92dd380 4686 logevent("Doing Diffie-Hellman key exchange");
e5574168 4687 /*
a92dd380 4688 * Now generate and send e for Diffie-Hellman.
e5574168 4689 */
27cd7fc2 4690 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 4691 s->pktout = ssh2_pkt_init(s->kex_init_value);
4692 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 4693 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4694
ff3187f6 4695 crWaitUntil(pktin);
4696 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 4697 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 4698 crStop(0);
7cca0d81 4699 }
ff3187f6 4700 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
4701 s->f = ssh2_pkt_getmp(pktin);
4702 if (!s->f) {
4703 bombout(("unable to parse key exchange reply packet"));
4704 crStop(0);
4705 }
4706 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 4707
27cd7fc2 4708 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4709
51470298 4710 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4711 if (ssh->kex == &ssh_diffiehellman_gex) {
4712 sha_uint32(&ssh->exhash, s->pbits);
4713 sha_mpint(&ssh->exhash, s->p);
4714 sha_mpint(&ssh->exhash, s->g);
a92dd380 4715 }
51470298 4716 sha_mpint(&ssh->exhash, s->e);
4717 sha_mpint(&ssh->exhash, s->f);
4718 sha_mpint(&ssh->exhash, s->K);
4719 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4720
27cd7fc2 4721 dh_cleanup(ssh->kex_ctx);
fabd1805 4722 ssh->kex_ctx = NULL;
3709bfe9 4723
7cca0d81 4724#if 0
765c4200 4725 debug(("Exchange hash is:\n"));
51470298 4726 dmemdump(s->exchange_hash, 20);
7cca0d81 4727#endif
4728
51470298 4729 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4730 if (!s->hkey ||
4731 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 4732 (char *)s->exchange_hash, 20)) {
6b5cf8b4 4733 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 4734 crStop(0);
8d5de777 4735 }
e5574168 4736
4737 /*
7cca0d81 4738 * Authenticate remote host: verify host key. (We've already
4739 * checked the signature of the exchange hash.)
e5574168 4740 */
51470298 4741 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4742 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4743 verify_ssh_host_key(ssh->frontend,
4744 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4745 s->keystr, s->fingerprint);
4746 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4747 logevent("Host key fingerprint is:");
51470298 4748 logevent(s->fingerprint);
5e0d7cb8 4749 }
51470298 4750 sfree(s->fingerprint);
4751 sfree(s->keystr);
4752 ssh->hostkey->freekey(s->hkey);
d39f364a 4753
4754 /*
9442dd57 4755 * The exchange hash from the very first key exchange is also
4756 * the session id, used in session key construction and
4757 * authentication.
4758 */
4759 if (s->first_kex)
4760 memcpy(ssh->v2_session_id, s->exchange_hash,
4761 sizeof(s->exchange_hash));
4762
4763 /*
7cca0d81 4764 * Send SSH2_MSG_NEWKEYS.
d39f364a 4765 */
ff3187f6 4766 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 4767 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 4768 ssh->outgoing_data_size = 0; /* start counting from here */
4769
4770 /*
4771 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 4772 * client-to-server session keys.
9442dd57 4773 */
4774 if (ssh->cs_cipher_ctx)
4775 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4776 ssh->cscipher = s->cscipher_tobe;
4777 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4778
4779 if (ssh->cs_mac_ctx)
4780 ssh->csmac->free_context(ssh->cs_mac_ctx);
4781 ssh->csmac = s->csmac_tobe;
4782 ssh->cs_mac_ctx = ssh->csmac->make_context();
4783
4784 if (ssh->cs_comp_ctx)
4785 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4786 ssh->cscomp = s->cscomp_tobe;
4787 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4788
4789 /*
4790 * Set IVs on client-to-server keys. Here we use the exchange
4791 * hash from the _first_ key exchange.
4792 */
4793 {
4794 unsigned char keyspace[40];
4795 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4796 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4797 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4798 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4799 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4800 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4801 }
4802
4803 logeventf(ssh, "Initialised %.200s client->server encryption",
4804 ssh->cscipher->text_name);
4805 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4806 ssh->csmac->text_name);
4807 if (ssh->cscomp->text_name)
4808 logeventf(ssh, "Initialised %s compression",
4809 ssh->cscomp->text_name);
590f6a5f 4810
4811 /*
4812 * Now our end of the key exchange is complete, we can send all
4813 * our queued higher-layer packets.
4814 */
4815 ssh->queueing = FALSE;
4816 ssh2_pkt_queuesend(ssh);
d39f364a 4817
4818 /*
8406eaf9 4819 * Expect SSH2_MSG_NEWKEYS from server.
4820 */
ff3187f6 4821 crWaitUntil(pktin);
4822 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 4823 bombout(("expected new-keys packet from server"));
7ffdbc1a 4824 crStop(0);
8406eaf9 4825 }
9442dd57 4826 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 4827
4828 /*
9442dd57 4829 * We've seen server NEWKEYS, so create and initialise
4830 * server-to-client session keys.
d39f364a 4831 */
371e569c 4832 if (ssh->sc_cipher_ctx)
4833 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4834 ssh->sccipher = s->sccipher_tobe;
371e569c 4835 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4836
e0e1a00d 4837 if (ssh->sc_mac_ctx)
4838 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4839 ssh->scmac = s->scmac_tobe;
e0e1a00d 4840 ssh->sc_mac_ctx = ssh->scmac->make_context();
4841
5366aed8 4842 if (ssh->sc_comp_ctx)
4843 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4844 ssh->sccomp = s->sccomp_tobe;
5366aed8 4845 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4846
d39f364a 4847 /*
9442dd57 4848 * Set IVs on server-to-client keys. Here we use the exchange
4849 * hash from the _first_ key exchange.
d39f364a 4850 */
51470298 4851 {
4852 unsigned char keyspace[40];
51470298 4853 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4854 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4855 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4856 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4857 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4858 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4859 }
57356d63 4860 logeventf(ssh, "Initialised %.200s server->client encryption",
4861 ssh->sccipher->text_name);
6c135243 4862 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4863 ssh->scmac->text_name);
57356d63 4864 if (ssh->sccomp->text_name)
4865 logeventf(ssh, "Initialised %s decompression",
4866 ssh->sccomp->text_name);
9442dd57 4867
4868 /*
4869 * Free key exchange data.
4870 */
679539d7 4871 freebn(s->f);
679539d7 4872 freebn(s->K);
b3949e7e 4873 if (ssh->kex == &ssh_diffiehellman_gex) {
4874 freebn(s->g);
4875 freebn(s->p);
4876 }
d39f364a 4877
033b4cef 4878 /*
9442dd57 4879 * Key exchange is over. Schedule a timer for our next rekey.
4880 */
4881 ssh->kex_in_progress = FALSE;
4882 ssh->next_rekey = schedule_timer(REKEY_TIMEOUT, ssh2_timer, ssh);
4883
4884 /*
0db56f73 4885 * If this is the first key exchange phase, we must pass the
4886 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4887 * wants to see it but because it will need time to initialise
4888 * itself before it sees an actual packet. In subsequent key
4889 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4890 * it would only confuse the layer above.
4891 */
51470298 4892 if (!s->first_kex) {
b09eaa88 4893 crReturn(1);
0db56f73 4894 }
51470298 4895 s->first_kex = 0;
0db56f73 4896
4897 /*
7cca0d81 4898 * Now we're encrypting. Begin returning 1 to the protocol main
4899 * function so that other things can run on top of the
4900 * transport. If we ever see a KEXINIT, we must go back to the
4901 * start.
9442dd57 4902 *
4903 * We _also_ go back to the start if we see pktin==NULL and
4904 * inlen==-1, because this is a special signal meaning
4905 * `initiate client-driven rekey', and `in' contains a message
4906 * giving the reason for the rekey.
033b4cef 4907 */
9442dd57 4908 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
4909 (!pktin && inlen == -1))) {
32874aea 4910 crReturn(1);
e96adf72 4911 }
9442dd57 4912 if (pktin) {
4913 logevent("Server initiated key re-exchange");
4914 } else {
4915 logevent((char *)in);
4916 }
7cca0d81 4917 goto begin_key_exchange;
e5574168 4918
4919 crFinish(1);
4920}
4921
7cca0d81 4922/*
783415f8 4923 * Add data to an SSH2 channel output buffer.
4924 */
32874aea 4925static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4926 int len)
4927{
5471d09a 4928 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4929}
4930
4931/*
4932 * Attempt to send data on an SSH2 channel.
4933 */
5471d09a 4934static int ssh2_try_send(struct ssh_channel *c)
32874aea 4935{
51470298 4936 Ssh ssh = c->ssh;
ff3187f6 4937 struct Packet *pktout;
51470298 4938
5471d09a 4939 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4940 int len;
4941 void *data;
4942 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4943 if ((unsigned)len > c->v.v2.remwindow)
4944 len = c->v.v2.remwindow;
4945 if ((unsigned)len > c->v.v2.remmaxpkt)
4946 len = c->v.v2.remmaxpkt;
ff3187f6 4947 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4948 ssh2_pkt_adduint32(pktout, c->remoteid);
4949 dont_log_data(ssh, pktout, PKTLOG_OMIT);
4950 ssh2_pkt_addstring_start(pktout);
4951 ssh2_pkt_addstring_data(pktout, data, len);
4952 end_log_omission(ssh, pktout);
4953 ssh2_pkt_send(ssh, pktout);
5471d09a 4954 bufchain_consume(&c->v.v2.outbuffer, len);
4955 c->v.v2.remwindow -= len;
4956 }
4957
4958 /*
4959 * After having sent as much data as we can, return the amount
4960 * still buffered.
4961 */
4962 return bufchain_size(&c->v.v2.outbuffer);
4963}
4964
4965/*
4966 * Potentially enlarge the window on an SSH2 channel.
4967 */
4968static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4969{
51470298 4970 Ssh ssh = c->ssh;
4971
6b69f42e 4972 /*
4973 * Never send WINDOW_ADJUST for a channel that the remote side
4974 * already thinks it's closed; there's no point, since it won't
4975 * be sending any more data anyway.
4976 */
4977 if (c->closes != 0)
4978 return;
4979
5471d09a 4980 if (newwin > c->v.v2.locwindow) {
ff3187f6 4981 struct Packet *pktout;
4982
4983 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4984 ssh2_pkt_adduint32(pktout, c->remoteid);
4985 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
4986 ssh2_pkt_send(ssh, pktout);
5471d09a 4987 c->v.v2.locwindow = newwin;
783415f8 4988 }
4989}
4990
51df0ab5 4991static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 4992{
4993 unsigned i = ssh_pkt_getuint32(pktin);
4994 struct ssh_channel *c;
4995 c = find234(ssh->channels, &i, ssh_channelfind);
4996 if (c && !c->closes)
4997 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
4998}
4999
51df0ab5 5000static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5001{
5002 char *data;
5003 int length;
5004 unsigned i = ssh_pkt_getuint32(pktin);
5005 struct ssh_channel *c;
5006 c = find234(ssh->channels, &i, ssh_channelfind);
5007 if (!c)
5008 return; /* nonexistent channel */
5009 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5010 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5011 return; /* extended but not stderr */
5012 ssh_pkt_getstring(pktin, &data, &length);
5013 if (data) {
5014 int bufsize = 0;
5015 c->v.v2.locwindow -= length;
5016 switch (c->type) {
5017 case CHAN_MAINSESSION:
5018 bufsize =
5019 from_backend(ssh->frontend, pktin->type ==
5020 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5021 data, length);
5022 break;
5023 case CHAN_X11:
5024 bufsize = x11_send(c->u.x11.s, data, length);
5025 break;
5026 case CHAN_SOCKDATA:
5027 bufsize = pfd_send(c->u.pfd.s, data, length);
5028 break;
5029 case CHAN_AGENT:
5030 while (length > 0) {
5031 if (c->u.a.lensofar < 4) {
5032 int l = min(4 - c->u.a.lensofar, length);
5033 memcpy(c->u.a.msglen + c->u.a.lensofar,
5034 data, l);
5035 data += l;
5036 length -= l;
5037 c->u.a.lensofar += l;
5038 }
5039 if (c->u.a.lensofar == 4) {
5040 c->u.a.totallen =
5041 4 + GET_32BIT(c->u.a.msglen);
5042 c->u.a.message = snewn(c->u.a.totallen,
5043 unsigned char);
5044 memcpy(c->u.a.message, c->u.a.msglen, 4);
5045 }
5046 if (c->u.a.lensofar >= 4 && length > 0) {
5047 int l =
5048 min(c->u.a.totallen - c->u.a.lensofar,
5049 length);
5050 memcpy(c->u.a.message + c->u.a.lensofar,
5051 data, l);
5052 data += l;
5053 length -= l;
5054 c->u.a.lensofar += l;
5055 }
5056 if (c->u.a.lensofar == c->u.a.totallen) {
5057 void *reply;
5058 int replylen;
5059 if (agent_query(c->u.a.message,
5060 c->u.a.totallen,
5061 &reply, &replylen,
5062 ssh_agentf_callback, c))
5063 ssh_agentf_callback(c, reply, replylen);
5064 sfree(c->u.a.message);
5065 c->u.a.lensofar = 0;
5066 }
5067 }
5068 bufsize = 0;
5069 break;
5070 }
5071 /*
5072 * If we are not buffering too much data,
5073 * enlarge the window again at the remote side.
5074 */
5075 if (bufsize < OUR_V2_WINSIZE)
5076 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5077 }
5078}
5079
5080static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5081{
5082 unsigned i = ssh_pkt_getuint32(pktin);
5083 struct ssh_channel *c;
5084
5085 c = find234(ssh->channels, &i, ssh_channelfind);
5086 if (!c)
5087 return; /* nonexistent channel */
5088
5089 if (c->type == CHAN_X11) {
5090 /*
5091 * Remote EOF on an X11 channel means we should
5092 * wrap up and close the channel ourselves.
5093 */
5094 x11_close(c->u.x11.s);
5095 sshfwd_close(c);
5096 } else if (c->type == CHAN_AGENT) {
5097 sshfwd_close(c);
5098 } else if (c->type == CHAN_SOCKDATA) {
5099 pfd_close(c->u.pfd.s);
5100 sshfwd_close(c);
5101 }
5102}
5103
5104static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5105{
5106 unsigned i = ssh_pkt_getuint32(pktin);
5107 struct ssh_channel *c;
5108 struct Packet *pktout;
5109
5110 c = find234(ssh->channels, &i, ssh_channelfind);
5111 if (!c || ((int)c->remoteid) == -1) {
5112 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5113 c ? "half-open" : "nonexistent", i));
5114 return;
5115 }
5116 /* Do pre-close processing on the channel. */
5117 switch (c->type) {
5118 case CHAN_MAINSESSION:
5119 ssh->mainchan = NULL;
5120 update_specials_menu(ssh->frontend);
5121 break;
5122 case CHAN_X11:
5123 if (c->u.x11.s != NULL)
5124 x11_close(c->u.x11.s);
5125 sshfwd_close(c);
5126 break;
5127 case CHAN_AGENT:
5128 sshfwd_close(c);
5129 break;
5130 case CHAN_SOCKDATA:
5131 if (c->u.pfd.s != NULL)
5132 pfd_close(c->u.pfd.s);
5133 sshfwd_close(c);
5134 break;
5135 }
5136 if (c->closes == 0) {
5137 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5138 ssh2_pkt_adduint32(pktout, c->remoteid);
5139 ssh2_pkt_send(ssh, pktout);
5140 }
5141 del234(ssh->channels, c);
5142 bufchain_clear(&c->v.v2.outbuffer);
5143 sfree(c);
5144
5145 /*
5146 * See if that was the last channel left open.
5147 * (This is only our termination condition if we're
5148 * not running in -N mode.)
5149 */
5150 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5151 logevent("All channels closed. Disconnecting");
5152#if 0
5153 /*
5154 * We used to send SSH_MSG_DISCONNECT here,
5155 * because I'd believed that _every_ conforming
5156 * SSH2 connection had to end with a disconnect
5157 * being sent by at least one side; apparently
5158 * I was wrong and it's perfectly OK to
5159 * unceremoniously slam the connection shut
5160 * when you're done, and indeed OpenSSH feels
5161 * this is more polite than sending a
5162 * DISCONNECT. So now we don't.
5163 */
5164 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5165 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5166 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5167 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5168 ssh2_pkt_send_noqueue(ssh, s->pktout);
5169#endif
5170 ssh_closing((Plug)ssh, NULL, 0, 0);
5171 }
5172}
5173
5174static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5175{
5176 unsigned i = ssh_pkt_getuint32(pktin);
5177 struct ssh_channel *c;
5178 struct Packet *pktout;
5179
5180 c = find234(ssh->channels, &i, ssh_channelfind);
5181 if (!c)
5182 return; /* nonexistent channel */
5183 if (c->type != CHAN_SOCKDATA_DORMANT)
5184 return; /* dunno why they're confirming this */
5185 c->remoteid = ssh_pkt_getuint32(pktin);
5186 c->type = CHAN_SOCKDATA;
5187 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5188 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5189 if (c->u.pfd.s)
5190 pfd_confirm(c->u.pfd.s);
5191 if (c->closes) {
5192 /*
5193 * We have a pending close on this channel,
5194 * which we decided on before the server acked
5195 * the channel open. So now we know the
5196 * remoteid, we can close it again.
5197 */
5198 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5199 ssh2_pkt_adduint32(pktout, c->remoteid);
5200 ssh2_pkt_send(ssh, pktout);
5201 }
5202}
5203
5204static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5205{
5206 static const char *const reasons[] = {
5207 "<unknown reason code>",
5208 "Administratively prohibited",
5209 "Connect failed",
5210 "Unknown channel type",
5211 "Resource shortage",
5212 };
5213 unsigned i = ssh_pkt_getuint32(pktin);
5214 unsigned reason_code;
5215 char *reason_string;
5216 int reason_length;
5217 char *message;
5218 struct ssh_channel *c;
5219 c = find234(ssh->channels, &i, ssh_channelfind);
5220 if (!c)
5221 return; /* nonexistent channel */
5222 if (c->type != CHAN_SOCKDATA_DORMANT)
5223 return; /* dunno why they're failing this */
5224
5225 reason_code = ssh_pkt_getuint32(pktin);
5226 if (reason_code >= lenof(reasons))
5227 reason_code = 0; /* ensure reasons[reason_code] in range */
5228 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5229 message = dupprintf("Forwarded connection refused by"
5230 " server: %s [%.*s]", reasons[reason_code],
5231 reason_length, reason_string);
5232 logevent(message);
5233 sfree(message);
5234
5235 pfd_close(c->u.pfd.s);
5236
5237 del234(ssh->channels, c);
5238 sfree(c);
5239}
5240
5241static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5242{
5243 unsigned localid;
5244 char *type;
5245 int typelen, want_reply;
5246 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5247 struct ssh_channel *c;
5248 struct Packet *pktout;
5249
5250 localid = ssh_pkt_getuint32(pktin);
5251 ssh_pkt_getstring(pktin, &type, &typelen);
5252 want_reply = ssh2_pkt_getbool(pktin);
5253
5254 /*
5255 * First, check that the channel exists. Otherwise,
5256 * we can instantly disconnect with a rude message.
5257 */
5258 c = find234(ssh->channels, &localid, ssh_channelfind);
5259 if (!c) {
5260 char buf[80];
5261 sprintf(buf, "Received channel request for nonexistent"
5262 " channel %d", localid);
5263 logevent(buf);
5264 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5265 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5266 ssh2_pkt_addstring(pktout, buf);
5267 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5268 ssh2_pkt_send_noqueue(ssh, pktout);
5269 connection_fatal(ssh->frontend, "%s", buf);
5270 ssh_closing((Plug)ssh, NULL, 0, 0);
5271 return;
5272 }
5273
5274 /*
5275 * Having got the channel number, we now look at
5276 * the request type string to see if it's something
5277 * we recognise.
5278 */
5279 if (c == ssh->mainchan) {
5280 /*
5281 * We recognise "exit-status" and "exit-signal" on
5282 * the primary channel.
5283 */
5284 if (typelen == 11 &&
5285 !memcmp(type, "exit-status", 11)) {
5286
5287 ssh->exitcode = ssh_pkt_getuint32(pktin);
5288 logeventf(ssh, "Server sent command exit status %d",
5289 ssh->exitcode);
5290 reply = SSH2_MSG_CHANNEL_SUCCESS;
5291
5292 } else if (typelen == 11 &&
5293 !memcmp(type, "exit-signal", 11)) {
5294
5295 int is_plausible = TRUE, is_int = FALSE;
5296 char *fmt_sig = "", *fmt_msg = "";
5297 char *msg;
5298 int msglen = 0, core = FALSE;
5299 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5300 * provide an `int' for the signal, despite its
5301 * having been a `string' in the drafts since at
5302 * least 2001. (Fixed in session.c 1.147.) Try to
5303 * infer which we can safely parse it as. */
5304 {
5305 unsigned char *p = pktin->body +
5306 pktin->savedpos;
5307 long len = pktin->length - pktin->savedpos;
5308 unsigned long num = GET_32BIT(p); /* what is it? */
5309 /* If it's 0, it hardly matters; assume string */
5310 if (num == 0) {
5311 is_int = FALSE;
5312 } else {
5313 int maybe_int = FALSE, maybe_str = FALSE;
5314#define CHECK_HYPOTHESIS(offset, result) \
5315 do { \
5316 long q = offset; \
5317 if (q >= 0 && q+4 <= len) { \
5318 q = q + 4 + GET_32BIT(p+q); \
5319 if (q >= 0 && q+4 <= len && \
5320 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5321 result = TRUE; \
5322 } \
5323 } while(0)
5324 CHECK_HYPOTHESIS(4+1, maybe_int);
5325 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5326#undef CHECK_HYPOTHESIS
5327 if (maybe_int && !maybe_str)
5328 is_int = TRUE;
5329 else if (!maybe_int && maybe_str)
5330 is_int = FALSE;
5331 else
5332 /* Crikey. Either or neither. Panic. */
5333 is_plausible = FALSE;
5334 }
5335 }
5336 if (is_plausible) {
5337 if (is_int) {
5338 /* Old non-standard OpenSSH. */
5339 int signum = ssh_pkt_getuint32(pktin);
5340 fmt_sig = dupprintf(" %d", signum);
5341 } else {
5342 /* As per the drafts. */
5343 char *sig;
5344 int siglen;
5345 ssh_pkt_getstring(pktin, &sig, &siglen);
5346 /* Signal name isn't supposed to be blank, but
5347 * let's cope gracefully if it is. */
5348 if (siglen) {
5349 fmt_sig = dupprintf(" \"%.*s\"",
5350 siglen, sig);
5351 }
5352 }
5353 core = ssh2_pkt_getbool(pktin);
5354 ssh_pkt_getstring(pktin, &msg, &msglen);
5355 if (msglen) {
5356 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5357 }
5358 /* ignore lang tag */
5359 } /* else don't attempt to parse */
5360 logeventf(ssh, "Server exited on signal%s%s%s",
5361 fmt_sig, core ? " (core dumped)" : "",
5362 fmt_msg);
5363 if (*fmt_sig) sfree(fmt_sig);
5364 if (*fmt_msg) sfree(fmt_msg);
5365 reply = SSH2_MSG_CHANNEL_SUCCESS;
5366
5367 }
5368 } else {
5369 /*
5370 * This is a channel request we don't know
5371 * about, so we now either ignore the request
5372 * or respond with CHANNEL_FAILURE, depending
5373 * on want_reply.
5374 */
5375 reply = SSH2_MSG_CHANNEL_FAILURE;
5376 }
5377 if (want_reply) {
5378 pktout = ssh2_pkt_init(reply);
5379 ssh2_pkt_adduint32(pktout, c->remoteid);
5380 ssh2_pkt_send(ssh, pktout);
5381 }
5382}
5383
5384static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5385{
5386 char *type;
5387 int typelen, want_reply;
5388 struct Packet *pktout;
5389
5390 ssh_pkt_getstring(pktin, &type, &typelen);
5391 want_reply = ssh2_pkt_getbool(pktin);
5392
5393 /*
5394 * We currently don't support any global requests
5395 * at all, so we either ignore the request or
5396 * respond with REQUEST_FAILURE, depending on
5397 * want_reply.
5398 */
5399 if (want_reply) {
5400 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5401 ssh2_pkt_send(ssh, pktout);
5402 }
5403}
5404
5405static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5406{
5407 char *type;
5408 int typelen;
5409 char *peeraddr;
5410 int peeraddrlen;
5411 int peerport;
5412 char *error = NULL;
5413 struct ssh_channel *c;
5414 unsigned remid, winsize, pktsize;
5415 struct Packet *pktout;
5416
5417 ssh_pkt_getstring(pktin, &type, &typelen);
5418 c = snew(struct ssh_channel);
5419 c->ssh = ssh;
5420
5421 remid = ssh_pkt_getuint32(pktin);
5422 winsize = ssh_pkt_getuint32(pktin);
5423 pktsize = ssh_pkt_getuint32(pktin);
5424
5425 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5426 char *addrstr;
5427
5428 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5429 addrstr = snewn(peeraddrlen+1, char);
5430 memcpy(addrstr, peeraddr, peeraddrlen);
5431 addrstr[peeraddrlen] = '\0';
5432 peerport = ssh_pkt_getuint32(pktin);
5433
5434 logeventf(ssh, "Received X11 connect request from %s:%d",
5435 addrstr, peerport);
5436
5437 if (!ssh->X11_fwd_enabled)
5438 error = "X11 forwarding is not enabled";
5439 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5440 ssh->x11auth, addrstr, peerport,
5441 &ssh->cfg) != NULL) {
5442 error = "Unable to open an X11 connection";
5443 } else {
5444 logevent("Opening X11 forward connection succeeded");
5445 c->type = CHAN_X11;
5446 }
5447
5448 sfree(addrstr);
5449 } else if (typelen == 15 &&
5450 !memcmp(type, "forwarded-tcpip", 15)) {
5451 struct ssh_rportfwd pf, *realpf;
5452 char *dummy;
5453 int dummylen;
5454 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5455 pf.sport = ssh_pkt_getuint32(pktin);
5456 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5457 peerport = ssh_pkt_getuint32(pktin);
5458 realpf = find234(ssh->rportfwds, &pf, NULL);
5459 logeventf(ssh, "Received remote port %d open request "
5460 "from %s:%d", pf.sport, peeraddr, peerport);
5461 if (realpf == NULL) {
5462 error = "Remote port is not recognised";
5463 } else {
5464 const char *e = pfd_newconnect(&c->u.pfd.s,
5465 realpf->dhost,
5466 realpf->dport, c,
5467 &ssh->cfg);
5468 logeventf(ssh, "Attempting to forward remote port to "
5469 "%s:%d", realpf->dhost, realpf->dport);
5470 if (e != NULL) {
5471 logeventf(ssh, "Port open failed: %s", e);
5472 error = "Port open failed";
5473 } else {
5474 logevent("Forwarded port opened successfully");
5475 c->type = CHAN_SOCKDATA;
5476 }
5477 }
5478 } else if (typelen == 22 &&
5479 !memcmp(type, "auth-agent@openssh.com", 3)) {
5480 if (!ssh->agentfwd_enabled)
5481 error = "Agent forwarding is not enabled";
5482 else {
5483 c->type = CHAN_AGENT; /* identify channel type */
5484 c->u.a.lensofar = 0;
5485 }
5486 } else {
5487 error = "Unsupported channel type requested";
5488 }
5489
5490 c->remoteid = remid;
5491 if (error) {
5492 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5493 ssh2_pkt_adduint32(pktout, c->remoteid);
5494 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5495 ssh2_pkt_addstring(pktout, error);
5496 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5497 ssh2_pkt_send(ssh, pktout);
5498 logeventf(ssh, "Rejected channel open: %s", error);
5499 sfree(c);
5500 } else {
5501 c->localid = alloc_channel_id(ssh);
5502 c->closes = 0;
5503 c->v.v2.locwindow = OUR_V2_WINSIZE;
5504 c->v.v2.remwindow = winsize;
5505 c->v.v2.remmaxpkt = pktsize;
5506 bufchain_init(&c->v.v2.outbuffer);
5507 add234(ssh->channels, c);
5508 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5509 ssh2_pkt_adduint32(pktout, c->remoteid);
5510 ssh2_pkt_adduint32(pktout, c->localid);
5511 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5512 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5513 ssh2_pkt_send(ssh, pktout);
5514 }
5515}
5516
783415f8 5517/*
7cca0d81 5518 * Handle the SSH2 userauth and connection layers.
5519 */
ff3187f6 5520static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5521 struct Packet *pktin)
7cca0d81 5522{
51470298 5523 struct do_ssh2_authconn_state {
5524 enum {
5525 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5526 AUTH_PASSWORD,
5527 AUTH_KEYBOARD_INTERACTIVE
5528 } method;
5529 enum {
5530 AUTH_TYPE_NONE,
5531 AUTH_TYPE_PUBLICKEY,
5532 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5533 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5534 AUTH_TYPE_PASSWORD,
5535 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5536 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5537 } type;
5538 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5539 int tried_pubkey_config, tried_agent, tried_keyb_inter;
5540 int kbd_inter_running;
5541 int we_are_in;
5542 int num_prompts, curr_prompt, echo;
5543 char username[100];
5544 int got_username;
85fdbe25 5545 char pwprompt[512];
51470298 5546 char password[100];
5547 void *publickey_blob;
5548 int publickey_bloblen;
5549 unsigned char request[5], *response, *p;
5550 int responselen;
5551 int keyi, nkeys;
5552 int authed;
5553 char *pkblob, *alg, *commentp;
5554 int pklen, alglen, commentlen;
5555 int siglen, retlen, len;
5556 char *q, *agentreq, *ret;
5557 int try_send;
73feed4f 5558 int num_env, env_left, env_ok;
ff3187f6 5559 struct Packet *pktout;
51470298 5560 };
5561 crState(do_ssh2_authconn_state);
5562
5563 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 5564
7cca0d81 5565 /*
5566 * Request userauth protocol, and await a response to it.
5567 */
ff3187f6 5568 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5569 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5570 ssh2_pkt_send(ssh, s->pktout);
5571 crWaitUntilV(pktin);
5572 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 5573 bombout(("Server refused user authentication protocol"));
7ffdbc1a 5574 crStopV;
8d5de777 5575 }
7cca0d81 5576
5577 /*
1408a877 5578 * We repeat this whole loop, including the username prompt,
5579 * until we manage a successful authentication. If the user
51470298 5580 * types the wrong _password_, they can be sent back to the
5581 * beginning to try another username, if this is configured on.
5582 * (If they specify a username in the config, they are never
5583 * asked, even if they do give a wrong password.)
1408a877 5584 *
5585 * I think this best serves the needs of
5586 *
5587 * - the people who have no configuration, no keys, and just
5588 * want to try repeated (username,password) pairs until they
5589 * type both correctly
5590 *
5591 * - people who have keys and configuration but occasionally
5592 * need to fall back to passwords
5593 *
5594 * - people with a key held in Pageant, who might not have
5595 * logged in to a particular machine before; so they want to
5596 * type a username, and then _either_ their key will be
5597 * accepted, _or_ they will type a password. If they mistype
5598 * the username they will want to be able to get back and
5599 * retype it!
7cca0d81 5600 */
51470298 5601 s->username[0] = '\0';
5602 s->got_username = FALSE;
1408a877 5603 do {
1408a877 5604 /*
5605 * Get a username.
5606 */
86916870 5607 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 5608 /*
5609 * We got a username last time round this loop, and
5610 * with change_username turned off we don't try to get
5611 * it again.
5612 */
aa09f7d0 5613 } else if (!*ssh->cfg.username) {
c0a81592 5614 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 5615 if (!ssh_get_line("login as: ",
51470298 5616 s->username, sizeof(s->username), FALSE)) {
32874aea 5617 /*
5618 * get_line failed to get a username.
5619 * Terminate.
5620 */
5621 logevent("No username provided. Abandoning session.");
3bb2f322 5622 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5623 crStopV;
32874aea 5624 }
5625 } else {
51470298 5626 int ret; /* need not be saved across crReturn */
5627 c_write_str(ssh, "login as: ");
5628 ssh->send_ok = 1;
5629 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 5630 do {
ff3187f6 5631 crWaitUntilV(!pktin);
51470298 5632 ret = process_userpass_input(ssh, in, inlen);
0405e71f 5633 } while (ret == 0);
5634 if (ret < 0)
5635 cleanup_exit(0);
4ca0c9d1 5636 c_write_str(ssh, "\r\n");
32874aea 5637 }
51470298 5638 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 5639 } else {
57356d63 5640 char *stuff;
86916870 5641 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 5642 s->username[sizeof(s->username)-1] = '\0';
65a22376 5643 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 5644 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 5645 c_write_str(ssh, stuff);
57356d63 5646 sfree(stuff);
7cca0d81 5647 }
5648 }
51470298 5649 s->got_username = TRUE;
7cca0d81 5650
65a22376 5651 /*
1408a877 5652 * Send an authentication request using method "none": (a)
5653 * just in case it succeeds, and (b) so that we know what
5654 * authentication methods we can usefully try next.
65a22376 5655 */
51470298 5656 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5657
ff3187f6 5658 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5659 ssh2_pkt_addstring(s->pktout, s->username);
5660 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
5661 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5662 ssh2_pkt_send(ssh, s->pktout);
51470298 5663 s->type = AUTH_TYPE_NONE;
5664 s->gotit = FALSE;
5665 s->we_are_in = FALSE;
5666
5667 s->tried_pubkey_config = FALSE;
5668 s->tried_agent = FALSE;
5669 s->tried_keyb_inter = FALSE;
5670 s->kbd_inter_running = FALSE;
86916870 5671 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 5672 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 5673 int keytype;
6c6d9ed9 5674 logeventf(ssh, "Reading private key file \"%.150s\"",
5675 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 5676 keytype = key_type(&ssh->cfg.keyfile);
51470298 5677 if (keytype == SSH_KEYTYPE_SSH2) {
5678 s->publickey_blob =
9a30e26b 5679 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 5680 &s->publickey_bloblen, NULL);
51470298 5681 } else {
57356d63 5682 char *msgbuf;
c2ad7d0d 5683 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 5684 key_type_to_str(keytype));
57356d63 5685 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 5686 " (%s)\r\n",
5687 filename_to_str(&ssh->cfg.keyfile),
57356d63 5688 key_type_to_str(keytype));
51470298 5689 c_write_str(ssh, msgbuf);
57356d63 5690 sfree(msgbuf);
51470298 5691 s->publickey_blob = NULL;
231ee168 5692 }
396778f1 5693 } else
51470298 5694 s->publickey_blob = NULL;
65a22376 5695
1408a877 5696 while (1) {
5697 /*
5698 * Wait for the result of the last authentication request.
5699 */
51470298 5700 if (!s->gotit)
ff3187f6 5701 crWaitUntilV(pktin);
5702 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 5703 char *banner;
5704 int size;
5705 /*
5706 * Don't show the banner if we're operating in
5707 * non-verbose non-interactive mode. (It's probably
5708 * a script, which means nobody will read the
5709 * banner _anyway_, and moreover the printing of
5710 * the banner will screw up processing on the
5711 * output of (say) plink.)
5712 */
5713 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 5714 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 5715 if (banner)
51470298 5716 c_write_untrusted(ssh, banner, size);
32874aea 5717 }
ff3187f6 5718 crWaitUntilV(pktin);
1408a877 5719 }
ff3187f6 5720 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 5721 logevent("Access granted");
51470298 5722 s->we_are_in = TRUE;
1408a877 5723 break;
5724 }
65a22376 5725
51470298 5726 if (s->kbd_inter_running &&
ff3187f6 5727 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 5728 /*
45068b27 5729 * This is either a further set-of-prompts packet
5730 * in keyboard-interactive authentication, or it's
5731 * the same one and we came back here with `gotit'
5732 * set. In the former case, we must reset the
5733 * curr_prompt variable.
b3186d64 5734 */
51470298 5735 if (!s->gotit)
5736 s->curr_prompt = 0;
ff3187f6 5737 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 5738 bombout(("Strange packet received during authentication: type %d",
ff3187f6 5739 pktin->type));
7ffdbc1a 5740 crStopV;
65a22376 5741 }
5742
51470298 5743 s->gotit = FALSE;
65a22376 5744
1408a877 5745 /*
5746 * OK, we're now sitting on a USERAUTH_FAILURE message, so
5747 * we can look at the string in it and know what we can
5748 * helpfully try next.
5749 */
ff3187f6 5750 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 5751 char *methods;
5752 int methlen;
ff3187f6 5753 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 5754 s->kbd_inter_running = FALSE;
ff3187f6 5755 if (!ssh2_pkt_getbool(pktin)) {
1408a877 5756 /*
5757 * We have received an unequivocal Access
5758 * Denied. This can translate to a variety of
5759 * messages:
5760 *
5761 * - if we'd just tried "none" authentication,
5762 * it's not worth printing anything at all
5763 *
5764 * - if we'd just tried a public key _offer_,
5765 * the message should be "Server refused our
5766 * key" (or no message at all if the key
5767 * came from Pageant)
5768 *
5769 * - if we'd just tried anything else, the
5770 * message really should be "Access denied".
5771 *
5772 * Additionally, if we'd just tried password
5773 * authentication, we should break out of this
5774 * whole loop so as to go back to the username
91f57d1f 5775 * prompt (iff we're configured to allow
5776 * username change attempts).
1408a877 5777 */
51470298 5778 if (s->type == AUTH_TYPE_NONE) {
1408a877 5779 /* do nothing */
51470298 5780 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5781 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5782 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5783 c_write_str(ssh, "Server refused our key\r\n");
1408a877 5784 logevent("Server refused public key");
51470298 5785 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 5786 /* server declined keyboard-interactive; ignore */
1408a877 5787 } else {
51470298 5788 c_write_str(ssh, "Access denied\r\n");
1408a877 5789 logevent("Access denied");
91f57d1f 5790 if (s->type == AUTH_TYPE_PASSWORD &&
5791 ssh->cfg.change_username) {
6c9dce7c 5792 /* XXX perhaps we should allow
5793 * keyboard-interactive to do this too? */
51470298 5794 s->we_are_in = FALSE;
1408a877 5795 break;
5796 }
5797 }
5798 } else {
51470298 5799 c_write_str(ssh, "Further authentication required\r\n");
1408a877 5800 logevent("Further authentication required");
5801 }
65a22376 5802
51470298 5803 s->can_pubkey =
32874aea 5804 in_commasep_string("publickey", methods, methlen);
51470298 5805 s->can_passwd =
32874aea 5806 in_commasep_string("password", methods, methlen);
86916870 5807 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 5808 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 5809 }
65a22376 5810
51470298 5811 s->method = 0;
5812 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 5813 s->need_pw = FALSE;
65a22376 5814
0405e71f 5815 /*
5816 * Most password/passphrase prompts will be
5817 * non-echoing, so we set this to 0 by default.
5818 * Exception is that some keyboard-interactive prompts
5819 * can be echoing, in which case we'll set this to 1.
5820 */
51470298 5821 s->echo = 0;
0405e71f 5822
51470298 5823 if (!s->method && s->can_pubkey &&
5824 agent_exists() && !s->tried_agent) {
1983e559 5825 /*
5826 * Attempt public-key authentication using Pageant.
5827 */
1983e559 5828 void *r;
51470298 5829 s->authed = FALSE;
1983e559 5830
51470298 5831 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5832 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 5833
51470298 5834 s->tried_agent = TRUE;
1983e559 5835
5836 logevent("Pageant is running. Requesting keys.");
5837
5838 /* Request the keys held by the agent. */
51470298 5839 PUT_32BIT(s->request, 1);
5840 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 5841 if (!agent_query(s->request, 5, &r, &s->responselen,
5842 ssh_agent_callback, ssh)) {
5843 do {
5844 crReturnV;
ff3187f6 5845 if (pktin) {
839f10db 5846 bombout(("Unexpected data from server while"
5847 " waiting for agent response"));
5848 crStopV;
5849 }
ff3187f6 5850 } while (pktin || inlen > 0);
839f10db 5851 r = ssh->agent_response;
5852 s->responselen = ssh->agent_response_len;
5853 }
51470298 5854 s->response = (unsigned char *) r;
5855 if (s->response && s->responselen >= 5 &&
5856 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5857 s->p = s->response + 5;
5858 s->nkeys = GET_32BIT(s->p);
5859 s->p += 4;
32874aea 5860 {
5861 char buf[64];
51470298 5862 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 5863 logevent(buf);
5864 }
51470298 5865 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 5866 void *vret;
1983e559 5867
32874aea 5868 {
5869 char buf[64];
51470298 5870 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 5871 logevent(buf);
5872 }
51470298 5873 s->pklen = GET_32BIT(s->p);
5874 s->p += 4;
5875 if (s->publickey_blob &&
5876 s->pklen == s->publickey_bloblen &&
5877 !memcmp(s->p, s->publickey_blob,
5878 s->publickey_bloblen)) {
396778f1 5879 logevent("This key matches configured key file");
51470298 5880 s->tried_pubkey_config = 1;
396778f1 5881 }
d8baa528 5882 s->pkblob = (char *)s->p;
51470298 5883 s->p += s->pklen;
5884 s->alglen = GET_32BIT(s->pkblob);
5885 s->alg = s->pkblob + 4;
5886 s->commentlen = GET_32BIT(s->p);
5887 s->p += 4;
d8baa528 5888 s->commentp = (char *)s->p;
51470298 5889 s->p += s->commentlen;
ff3187f6 5890 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5891 ssh2_pkt_addstring(s->pktout, s->username);
5892 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5893 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5894 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
5895 ssh2_pkt_addstring_start(s->pktout);
5896 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5897 ssh2_pkt_addstring_start(s->pktout);
5898 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5899 ssh2_pkt_send(ssh, s->pktout);
5900
5901 crWaitUntilV(pktin);
5902 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 5903 logevent("Key refused");
5904 continue;
5905 }
5906
32874aea 5907 if (flags & FLAG_VERBOSE) {
51470298 5908 c_write_str(ssh, "Authenticating with "
5909 "public key \"");
5910 c_write(ssh, s->commentp, s->commentlen);
5911 c_write_str(ssh, "\" from agent\r\n");
32874aea 5912 }
1983e559 5913
5914 /*
5915 * Server is willing to accept the key.
5916 * Construct a SIGN_REQUEST.
5917 */
ff3187f6 5918 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5919 ssh2_pkt_addstring(s->pktout, s->username);
5920 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5921 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5922 ssh2_pkt_addbool(s->pktout, TRUE);
5923 ssh2_pkt_addstring_start(s->pktout);
5924 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5925 ssh2_pkt_addstring_start(s->pktout);
5926 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5927
5928 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 5929 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5930 s->siglen -= 4;
51470298 5931 s->len = 1; /* message type */
5932 s->len += 4 + s->pklen; /* key blob */
5933 s->len += 4 + s->siglen; /* data to sign */
5934 s->len += 4; /* flags */
3d88e64d 5935 s->agentreq = snewn(4 + s->len, char);
51470298 5936 PUT_32BIT(s->agentreq, s->len);
5937 s->q = s->agentreq + 4;
5938 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5939 PUT_32BIT(s->q, s->pklen);
5940 s->q += 4;
5941 memcpy(s->q, s->pkblob, s->pklen);
5942 s->q += s->pklen;
5943 PUT_32BIT(s->q, s->siglen);
5944 s->q += 4;
1983e559 5945 /* Now the data to be signed... */
dda87a28 5946 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5947 PUT_32BIT(s->q, 20);
5948 s->q += 4;
5949 }
51470298 5950 memcpy(s->q, ssh->v2_session_id, 20);
5951 s->q += 20;
ff3187f6 5952 memcpy(s->q, s->pktout->data + 5,
5953 s->pktout->length - 5);
5954 s->q += s->pktout->length - 5;
1983e559 5955 /* And finally the (zero) flags word. */
51470298 5956 PUT_32BIT(s->q, 0);
839f10db 5957 if (!agent_query(s->agentreq, s->len + 4,
5958 &vret, &s->retlen,
5959 ssh_agent_callback, ssh)) {
5960 do {
5961 crReturnV;
ff3187f6 5962 if (pktin) {
839f10db 5963 bombout(("Unexpected data from server"
5964 " while waiting for agent"
5965 " response"));
5966 crStopV;
5967 }
ff3187f6 5968 } while (pktin || inlen > 0);
839f10db 5969 vret = ssh->agent_response;
5970 s->retlen = ssh->agent_response_len;
5971 }
51470298 5972 s->ret = vret;
5973 sfree(s->agentreq);
5974 if (s->ret) {
5975 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 5976 logevent("Sending Pageant's response");
ff3187f6 5977 ssh2_add_sigblob(ssh, s->pktout,
5978 s->pkblob, s->pklen,
51470298 5979 s->ret + 9,
5980 GET_32BIT(s->ret + 5));
ff3187f6 5981 ssh2_pkt_send(ssh, s->pktout);
51470298 5982 s->authed = TRUE;
1983e559 5983 break;
5984 } else {
32874aea 5985 logevent
5986 ("Pageant failed to answer challenge");
51470298 5987 sfree(s->ret);
1983e559 5988 }
5989 }
5990 }
51470298 5991 if (s->authed)
1983e559 5992 continue;
5993 }
29b1d0b3 5994 sfree(s->response);
1983e559 5995 }
5996
51470298 5997 if (!s->method && s->can_pubkey && s->publickey_blob
5998 && !s->tried_pubkey_config) {
1408a877 5999 unsigned char *pub_blob;
6000 char *algorithm, *comment;
6001 int pub_blob_len;
65a22376 6002
51470298 6003 s->tried_pubkey_config = TRUE;
65a22376 6004
51470298 6005 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6006 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6007
65a22376 6008 /*
1408a877 6009 * Try the public key supplied in the configuration.
6010 *
6011 * First, offer the public blob to see if the server is
6012 * willing to accept it.
65a22376 6013 */
d8baa528 6014 pub_blob =
9a30e26b 6015 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6016 &algorithm,
222d54dc 6017 &pub_blob_len,
6018 NULL);
1408a877 6019 if (pub_blob) {
ff3187f6 6020 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6021 ssh2_pkt_addstring(s->pktout, s->username);
6022 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6023 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6024 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6025 ssh2_pkt_addstring(s->pktout, algorithm);
6026 ssh2_pkt_addstring_start(s->pktout);
6027 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6028 pub_blob_len);
ff3187f6 6029 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6030 logevent("Offered public key");
1408a877 6031
ff3187f6 6032 crWaitUntilV(pktin);
6033 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6034 s->gotit = TRUE;
6035 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6036 continue; /* key refused; give up on it */
1408a877 6037 }
65a22376 6038
1408a877 6039 logevent("Offer of public key accepted");
65a22376 6040 /*
1408a877 6041 * Actually attempt a serious authentication using
6042 * the key.
65a22376 6043 */
9a30e26b 6044 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6045 sprintf(s->pwprompt,
32874aea 6046 "Passphrase for key \"%.100s\": ",
6047 comment);
51470298 6048 s->need_pw = TRUE;
1408a877 6049 } else {
51470298 6050 s->need_pw = FALSE;
1408a877 6051 }
4e520718 6052 if (flags & FLAG_VERBOSE) {
6053 c_write_str(ssh, "Authenticating with public key \"");
6054 c_write_str(ssh, comment);
6055 c_write_str(ssh, "\"\r\n");
6056 }
51470298 6057 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6058 }
1408a877 6059 }
6060
51470298 6061 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
6062 s->method = AUTH_KEYBOARD_INTERACTIVE;
6063 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6064 s->tried_keyb_inter = TRUE;
af659722 6065
51470298 6066 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6067 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6068
ff3187f6 6069 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6070 ssh2_pkt_addstring(s->pktout, s->username);
6071 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6072 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6073 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6074 ssh2_pkt_addstring(s->pktout, "");
6075 ssh2_pkt_send(ssh, s->pktout);
6076
6077 crWaitUntilV(pktin);
6078 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6079 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6080 s->gotit = TRUE;
af659722 6081 logevent("Keyboard-interactive authentication refused");
51470298 6082 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 6083 continue;
6084 }
6085
51470298 6086 s->kbd_inter_running = TRUE;
6087 s->curr_prompt = 0;
af659722 6088 }
6089
51470298 6090 if (s->kbd_inter_running) {
6091 s->method = AUTH_KEYBOARD_INTERACTIVE;
6092 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6093 s->tried_keyb_inter = TRUE;
af659722 6094
51470298 6095 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6096 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6097
51470298 6098 if (s->curr_prompt == 0) {
45068b27 6099 /*
6100 * We've got a fresh USERAUTH_INFO_REQUEST.
6101 * Display header data, and start going through
6102 * the prompts.
6103 */
6104 char *name, *inst, *lang;
6105 int name_len, inst_len, lang_len;
6106
ff3187f6 6107 ssh_pkt_getstring(pktin, &name, &name_len);
6108 ssh_pkt_getstring(pktin, &inst, &inst_len);
6109 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6110 if (name_len > 0) {
51470298 6111 c_write_untrusted(ssh, name, name_len);
6112 c_write_str(ssh, "\r\n");
45068b27 6113 }
6114 if (inst_len > 0) {
51470298 6115 c_write_untrusted(ssh, inst, inst_len);
6116 c_write_str(ssh, "\r\n");
45068b27 6117 }
ff3187f6 6118 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6119 }
af659722 6120
45068b27 6121 /*
6122 * If there are prompts remaining in the packet,
6123 * display one and get a response.
6124 */
51470298 6125 if (s->curr_prompt < s->num_prompts) {
45068b27 6126 char *prompt;
6127 int prompt_len;
af659722 6128
ff3187f6 6129 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6130 if (prompt_len > 0) {
85fdbe25 6131 static const char trunc[] = "<prompt truncated>: ";
6132 static const int prlen = sizeof(s->pwprompt) -
6133 lenof(trunc);
6134 if (prompt_len > prlen) {
6135 memcpy(s->pwprompt, prompt, prlen);
6136 strcpy(s->pwprompt + prlen, trunc);
6137 } else {
6138 memcpy(s->pwprompt, prompt, prompt_len);
6139 s->pwprompt[prompt_len] = '\0';
6140 }
45068b27 6141 } else {
51470298 6142 strcpy(s->pwprompt,
45068b27 6143 "<server failed to send prompt>: ");
6144 }
ff3187f6 6145 s->echo = ssh2_pkt_getbool(pktin);
51470298 6146 s->need_pw = TRUE;
45068b27 6147 } else
51470298 6148 s->need_pw = FALSE;
af659722 6149 }
6150
51470298 6151 if (!s->method && s->can_passwd) {
6152 s->method = AUTH_PASSWORD;
6153 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6154 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6155 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6156 ssh->savedhost);
6157 s->need_pw = TRUE;
1408a877 6158 }
6159
51470298 6160 if (s->need_pw) {
fa17a66e 6161 if (ssh_get_line) {
51470298 6162 if (!ssh_get_line(s->pwprompt, s->password,
6163 sizeof(s->password), TRUE)) {
1408a877 6164 /*
fa17a66e 6165 * get_line failed to get a password (for
6166 * example because one was supplied on the
6167 * command line which has already failed to
6168 * work). Terminate.
1408a877 6169 */
ff3187f6 6170 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6171 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6172 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6173 " to try");
ff3187f6 6174 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6175 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6176 logevent("Unable to authenticate");
a8327734 6177 connection_fatal(ssh->frontend,
6178 "Unable to authenticate");
3bb2f322 6179 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6180 crStopV;
1408a877 6181 }
6182 } else {
51470298 6183 int ret; /* need not be saved across crReturn */
6184 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6185 ssh->send_ok = 1;
1408a877 6186
51470298 6187 setup_userpass_input(ssh, s->password,
6188 sizeof(s->password), s->echo);
0405e71f 6189 do {
ff3187f6 6190 crWaitUntilV(!pktin);
51470298 6191 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6192 } while (ret == 0);
6193 if (ret < 0)
6194 cleanup_exit(0);
51470298 6195 c_write_str(ssh, "\r\n");
65a22376 6196 }
65a22376 6197 }
65a22376 6198
51470298 6199 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6200 /*
6201 * We have our passphrase. Now try the actual authentication.
6202 */
6203 struct ssh2_userkey *key;
222d54dc 6204 const char *error = NULL;
65a22376 6205
222d54dc 6206 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6207 &error);
1408a877 6208 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6209 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6210 c_write_str(ssh, "Wrong passphrase\r\n");
6211 s->tried_pubkey_config = FALSE;
1408a877 6212 } else {
222d54dc 6213 c_write_str(ssh, "Unable to load private key (");
6214 c_write_str(ssh, error);
6215 c_write_str(ssh, ")\r\n");
51470298 6216 s->tried_pubkey_config = TRUE;
1408a877 6217 }
6218 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6219 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6220 ssh2_pkt_addstring(s->pktout, s->username);
6221 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6222 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6223 ssh2_pkt_send(ssh, s->pktout);
51470298 6224 s->type = AUTH_TYPE_NONE;
1408a877 6225 } else {
1dd353b5 6226 unsigned char *pkblob, *sigblob, *sigdata;
6227 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6228 int p;
65a22376 6229
1408a877 6230 /*
6231 * We have loaded the private key and the server
6232 * has announced that it's willing to accept it.
6233 * Hallelujah. Generate a signature and send it.
6234 */
ff3187f6 6235 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6236 ssh2_pkt_addstring(s->pktout, s->username);
6237 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6238 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6239 ssh2_pkt_addbool(s->pktout, TRUE);
6240 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6241 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6242 ssh2_pkt_addstring_start(s->pktout);
6243 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6244
6245 /*
6246 * The data to be signed is:
6247 *
6248 * string session-id
6249 *
6250 * followed by everything so far placed in the
6251 * outgoing packet.
6252 */
ff3187f6 6253 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6254 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6255 sigdata_len -= 4;
92d60585 6256 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6257 p = 0;
6258 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6259 PUT_32BIT(sigdata+p, 20);
6260 p += 4;
6261 }
6262 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6263 memcpy(sigdata+p, s->pktout->data + 5,
6264 s->pktout->length - 5);
6265 p += s->pktout->length - 5;
dda87a28 6266 assert(p == sigdata_len);
d8baa528 6267 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6268 sigdata_len, &sigblob_len);
ff3187f6 6269 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6270 sigblob, sigblob_len);
6271 sfree(pkblob);
6272 sfree(sigblob);
1408a877 6273 sfree(sigdata);
6274
ff3187f6 6275 ssh2_pkt_send(ssh, s->pktout);
51470298 6276 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6277 key->alg->freekey(key->data);
1408a877 6278 }
51470298 6279 } else if (s->method == AUTH_PASSWORD) {
65a22376 6280 /*
1408a877 6281 * We send the password packet lumped tightly together with
6282 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6283 * string long enough to make the total length of the two
6284 * packets constant. This should ensure that a passive
6285 * listener doing traffic analyis can't work out the length
6286 * of the password.
6287 *
6288 * For this to work, we need an assumption about the
6289 * maximum length of the password packet. I think 256 is
6290 * pretty conservative. Anyone using a password longer than
6291 * that probably doesn't have much to worry about from
6292 * people who find out how long their password is!
65a22376 6293 */
ff3187f6 6294 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6295 ssh2_pkt_addstring(s->pktout, s->username);
6296 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6297 ssh2_pkt_addstring(s->pktout, "password");
6298 ssh2_pkt_addbool(s->pktout, FALSE);
6299 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6300 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 6301 memset(s->password, 0, sizeof(s->password));
ff3187f6 6302 end_log_omission(ssh, s->pktout);
6303 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6304 /*
1408a877 6305 * We'll include a string that's an exact multiple of the
6306 * cipher block size. If the cipher is NULL for some
6307 * reason, we don't do this trick at all because we gain
6308 * nothing by it.
65a22376 6309 */
51470298 6310 if (ssh->cscipher) {
32874aea 6311 int stringlen, i;
6312
51470298 6313 stringlen = (256 - ssh->deferred_len);
6314 stringlen += ssh->cscipher->blksize - 1;
6315 stringlen -= (stringlen % ssh->cscipher->blksize);
6316 if (ssh->cscomp) {
32874aea 6317 /*
6318 * Temporarily disable actual compression,
6319 * so we can guarantee to get this string
6320 * exactly the length we want it. The
6321 * compression-disabling routine should
6322 * return an integer indicating how many
6323 * bytes we should adjust our string length
6324 * by.
6325 */
5366aed8 6326 stringlen -=
6327 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 6328 }
ff3187f6 6329 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6330 ssh2_pkt_addstring_start(s->pktout);
6e9e9520 6331 for (i = 0; i < stringlen; i++) {
32874aea 6332 char c = (char) random_byte();
ff3187f6 6333 ssh2_pkt_addstring_data(s->pktout, &c, 1);
65a22376 6334 }
ff3187f6 6335 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6336 }
51470298 6337 ssh_pkt_defersend(ssh);
0d43337a 6338 logevent("Sent password");
51470298 6339 s->type = AUTH_TYPE_PASSWORD;
6340 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6341 if (s->curr_prompt == 0) {
ff3187f6 6342 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6343 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 6344 }
51470298 6345 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 6346 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6347 ssh2_pkt_addstring(s->pktout, s->password);
51470298 6348 memset(s->password, 0, sizeof(s->password));
ff3187f6 6349 end_log_omission(ssh, s->pktout);
51470298 6350 s->curr_prompt++;
45068b27 6351 }
51470298 6352 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 6353 ssh2_pkt_send(ssh, s->pktout);
45068b27 6354 } else {
6355 /*
6356 * If there are prompts remaining, we set
6357 * `gotit' so that we won't attempt to get
6358 * another packet. Then we go back round the
6359 * loop and will end up retrieving another
6360 * prompt out of the existing packet. Funky or
6361 * what?
6362 */
51470298 6363 s->gotit = TRUE;
45068b27 6364 }
51470298 6365 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 6366 } else {
51470298 6367 c_write_str(ssh, "No supported authentication methods"
6368 " left to try!\r\n");
6369 logevent("No supported authentications offered."
6370 " Disconnecting");
ff3187f6 6371 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6372 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6373 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 6374 " methods available");
ff3187f6 6375 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6376 ssh2_pkt_send_noqueue(ssh, s->pktout);
3bb2f322 6377 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6378 crStopV;
65a22376 6379 }
65a22376 6380 }
51470298 6381 } while (!s->we_are_in);
7cca0d81 6382
6383 /*
6384 * Now we're authenticated for the connection protocol. The
6385 * connection protocol will automatically have started at this
6386 * point; there's no need to send SERVICE_REQUEST.
6387 */
6388
0ed48730 6389 ssh->channels = newtree234(ssh_channelcmp);
6390
7cca0d81 6391 /*
b09eaa88 6392 * Set up handlers for some connection protocol messages, so we
6393 * don't have to handle them repeatedly in this coroutine.
6394 */
6395 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6396 ssh2_msg_channel_window_adjust;
51df0ab5 6397 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6398 ssh2_msg_global_request;
b09eaa88 6399
6400 /*
0ed48730 6401 * Create the main session channel.
7cca0d81 6402 */
0ed48730 6403 if (!ssh->cfg.ssh_no_shell) {
6404 ssh->mainchan = snew(struct ssh_channel);
6405 ssh->mainchan->ssh = ssh;
6406 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 6407 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6408 ssh2_pkt_addstring(s->pktout, "session");
6409 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 6410 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 6411 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6412 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6413 ssh2_pkt_send(ssh, s->pktout);
6414 crWaitUntilV(pktin);
6415 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 6416 bombout(("Server refused to open a session"));
6417 crStopV;
6418 /* FIXME: error data comes back in FAILURE packet */
6419 }
ff3187f6 6420 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 6421 bombout(("Server's channel confirmation cited wrong channel"));
6422 crStopV;
6423 }
ff3187f6 6424 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 6425 ssh->mainchan->type = CHAN_MAINSESSION;
6426 ssh->mainchan->closes = 0;
ff3187f6 6427 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6428 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 6429 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6430 add234(ssh->channels, ssh->mainchan);
62638676 6431 update_specials_menu(ssh->frontend);
0ed48730 6432 logevent("Opened channel for session");
6433 } else
6434 ssh->mainchan = NULL;
7cca0d81 6435
6436 /*
51df0ab5 6437 * Now we have a channel, make dispatch table entries for
6438 * general channel-based messages.
6439 */
6440 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6441 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6442 ssh2_msg_channel_data;
6443 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6444 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6445 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6446 ssh2_msg_channel_open_confirmation;
6447 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6448 ssh2_msg_channel_open_failure;
6449 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6450 ssh2_msg_channel_request;
6451 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6452 ssh2_msg_channel_open;
6453
6454 /*
783415f8 6455 * Potentially enable X11 forwarding.
6456 */
0ed48730 6457 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 6458 char proto[20], data[64];
6459 logevent("Requesting X11 forwarding");
302121de 6460 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 6461 data, sizeof(data), ssh->cfg.x11_auth);
6462 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 6463 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6464 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6465 ssh2_pkt_addstring(s->pktout, "x11-req");
6466 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6467 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6468 ssh2_pkt_addstring(s->pktout, proto);
6469 ssh2_pkt_addstring(s->pktout, data);
6470 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6471 ssh2_pkt_send(ssh, s->pktout);
32874aea 6472
b09eaa88 6473 crWaitUntilV(pktin);
32874aea 6474
ff3187f6 6475 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6476 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6477 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 6478 " packet type %d", pktin->type));
7ffdbc1a 6479 crStopV;
32874aea 6480 }
6481 logevent("X11 forwarding refused");
6482 } else {
6483 logevent("X11 forwarding enabled");
51470298 6484 ssh->X11_fwd_enabled = TRUE;
32874aea 6485 }
783415f8 6486 }
6487
6488 /*
bc240b21 6489 * Enable port forwardings.
6490 */
6491 {
bc240b21 6492 char type;
6493 int n;
a4fc0d74 6494 int sport,dport,sserv,dserv;
6ee9b735 6495 char sports[256], dports[256], saddr[256], host[256];
bc240b21 6496
51470298 6497 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 6498 /* Add port forwardings. */
86916870 6499 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 6500 while (*ssh->portfwd_strptr) {
6501 type = *ssh->portfwd_strptr++;
6ee9b735 6502 saddr[0] = '\0';
bc240b21 6503 n = 0;
6ee9b735 6504 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
6505 if (*ssh->portfwd_strptr == ':') {
6506 /*
6507 * We've seen a colon in the middle of the
6508 * source port number. This means that
6509 * everything we've seen until now is the
6510 * source _address_, so we'll move it into
6511 * saddr and start sports from the beginning
6512 * again.
6513 */
6514 ssh->portfwd_strptr++;
6515 sports[n] = '\0';
6516 strcpy(saddr, sports);
6517 n = 0;
6518 }
6519 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
6520 }
bc240b21 6521 sports[n] = 0;
820ebe3b 6522 if (type != 'D') {
6523 if (*ssh->portfwd_strptr == '\t')
6524 ssh->portfwd_strptr++;
6525 n = 0;
6526 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
6527 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
6528 }
6529 host[n] = 0;
6530 if (*ssh->portfwd_strptr == ':')
6531 ssh->portfwd_strptr++;
6532 n = 0;
6533 while (*ssh->portfwd_strptr) {
6534 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
6535 }
6536 dports[n] = 0;
51470298 6537 ssh->portfwd_strptr++;
820ebe3b 6538 dport = atoi(dports);
6539 dserv = 0;
6540 if (dport == 0) {
6541 dserv = 1;
6542 dport = net_service_lookup(dports);
6543 if (!dport) {
6544 logeventf(ssh, "Service lookup failed for destination"
6545 " port \"%s\"", dports);
6546 }
a4fc0d74 6547 }
820ebe3b 6548 } else {
6549 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 6550 dport = dserv = -1;
7d5b0f4d 6551 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 6552 }
bc240b21 6553 sport = atoi(sports);
a4fc0d74 6554 sserv = 0;
6555 if (sport == 0) {
6556 sserv = 1;
68a49acb 6557 sport = net_service_lookup(sports);
6558 if (!sport) {
57356d63 6559 logeventf(ssh, "Service lookup failed for source"
6560 " port \"%s\"", sports);
a4fc0d74 6561 }
6562 }
bc240b21 6563 if (sport && dport) {
94ab1ddf 6564 /* Set up a description of the source port. */
49b8f9c4 6565 static char *sportdesc;
6566 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
94ab1ddf 6567 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
6568 (int)(*saddr?1:0), ":",
6569 (int)(sserv ? strlen(sports) : 0), sports,
6570 sserv, "(", sport, sserv, ")");
bc240b21 6571 if (type == 'L') {
94ab1ddf 6572 /* Verbose description of the destination port */
6573 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
6574 host,
6575 (int)(dserv ? strlen(dports) : 0), dports,
6576 dserv, "(", dport, dserv, ")");
6577 const char *err = pfd_addforward(host, dport,
6578 *saddr ? saddr : NULL,
6579 sport, ssh, &ssh->cfg);
6580 if (err) {
6581 logeventf(ssh, "Local port %s forward to %s"
6582 " failed: %s", sportdesc, dportdesc, err);
6583 } else {
6584 logeventf(ssh, "Local port %s forwarding to %s",
6585 sportdesc, dportdesc);
6586 }
6587 sfree(dportdesc);
820ebe3b 6588 } else if (type == 'D') {
94ab1ddf 6589 const char *err = pfd_addforward(NULL, -1,
6590 *saddr ? saddr : NULL,
6591 sport, ssh, &ssh->cfg);
6592 if (err) {
6593 logeventf(ssh, "Local port %s SOCKS dynamic forward"
6594 " setup failed: %s", sportdesc, err);
6595 } else {
6596 logeventf(ssh, "Local port %s doing SOCKS"
6597 " dynamic forwarding", sportdesc);
6598 }
bc240b21 6599 } else {
6600 struct ssh_rportfwd *pf;
3d88e64d 6601 pf = snew(struct ssh_rportfwd);
bc240b21 6602 strcpy(pf->dhost, host);
6603 pf->dport = dport;
6604 pf->sport = sport;
51470298 6605 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 6606 logeventf(ssh, "Duplicate remote port forwarding"
6607 " to %s:%d", host, dport);
bc240b21 6608 sfree(pf);
6609 } else {
94ab1ddf 6610 logeventf(ssh, "Requesting remote port %s"
57356d63 6611 " forward to %s:%.*s%.*s%d%.*s",
94ab1ddf 6612 sportdesc,
57356d63 6613 host,
6614 (int)(dserv ? strlen(dports) : 0), dports,
6615 dserv, "(", dport, dserv, ")");
ff3187f6 6616 s->pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
6617 ssh2_pkt_addstring(s->pktout, "tcpip-forward");
6618 ssh2_pkt_addbool(s->pktout, 1);/* want reply */
49b8f9c4 6619 if (*saddr) {
ff3187f6 6620 ssh2_pkt_addstring(s->pktout, saddr);
49b8f9c4 6621 } else if (ssh->cfg.rport_acceptall) {
ff3187f6 6622 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
49b8f9c4 6623 } else {
ff3187f6 6624 ssh2_pkt_addstring(s->pktout, "127.0.0.1");
49b8f9c4 6625 }
ff3187f6 6626 ssh2_pkt_adduint32(s->pktout, sport);
6627 ssh2_pkt_send(ssh, s->pktout);
bc240b21 6628
b09eaa88 6629 crWaitUntilV(pktin);
bc240b21 6630
ff3187f6 6631 if (pktin->type != SSH2_MSG_REQUEST_SUCCESS) {
6632 if (pktin->type != SSH2_MSG_REQUEST_FAILURE) {
6b5cf8b4 6633 bombout(("Unexpected response to port "
c9886e66 6634 "forwarding request: packet type %d",
ff3187f6 6635 pktin->type));
7ffdbc1a 6636 crStopV;
bc240b21 6637 }
6638 logevent("Server refused this port forwarding");
6639 } else {
6640 logevent("Remote port forwarding enabled");
6641 }
6642 }
6643 }
94ab1ddf 6644 sfree(sportdesc);
bc240b21 6645 }
6646 }
6647 }
6648
6649 /*
36c2a3e9 6650 * Potentially enable agent forwarding.
6651 */
0ed48730 6652 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6653 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6654 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6655 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6656 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6657 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6658 ssh2_pkt_send(ssh, s->pktout);
32874aea 6659
b09eaa88 6660 crWaitUntilV(pktin);
32874aea 6661
ff3187f6 6662 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6663 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6664 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6665 " packet type %d", pktin->type));
7ffdbc1a 6666 crStopV;
32874aea 6667 }
6668 logevent("Agent forwarding refused");
6669 } else {
6670 logevent("Agent forwarding enabled");
51470298 6671 ssh->agentfwd_enabled = TRUE;
32874aea 6672 }
36c2a3e9 6673 }
6674
6675 /*
7cca0d81 6676 * Now allocate a pty for the session.
6677 */
0ed48730 6678 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6679 /* Unpick the terminal-speed string. */
6680 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6681 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6682 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6683 /* Build the pty request. */
ff3187f6 6684 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6685 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6686 ssh2_pkt_addstring(s->pktout, "pty-req");
6687 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6688 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6689 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6690 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6691 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6692 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6693 ssh2_pkt_addstring_start(s->pktout);
6694 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6695 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6696 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6697 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6698 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6699 ssh2_pkt_send(ssh, s->pktout);
51470298 6700 ssh->state = SSH_STATE_INTERMED;
32874aea 6701
b09eaa88 6702 crWaitUntilV(pktin);
32874aea 6703
ff3187f6 6704 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6705 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6706 bombout(("Unexpected response to pty request:"
ff3187f6 6707 " packet type %d", pktin->type));
7ffdbc1a 6708 crStopV;
32874aea 6709 }
51470298 6710 c_write_str(ssh, "Server refused to allocate pty\r\n");
6711 ssh->editing = ssh->echoing = 1;
32874aea 6712 } else {
a5dd8467 6713 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 6714 ssh->ospeed, ssh->ispeed);
32874aea 6715 }
0965bee0 6716 } else {
51470298 6717 ssh->editing = ssh->echoing = 1;
7cca0d81 6718 }
6719
6720 /*
73feed4f 6721 * Send environment variables.
6722 *
6723 * Simplest thing here is to send all the requests at once, and
6724 * then wait for a whole bunch of successes or failures.
6725 */
6726 if (ssh->mainchan && *ssh->cfg.environmt) {
6727 char *e = ssh->cfg.environmt;
6728 char *var, *varend, *val;
6729
6730 s->num_env = 0;
6731
6732 while (*e) {
6733 var = e;
6734 while (*e && *e != '\t') e++;
6735 varend = e;
6736 if (*e == '\t') e++;
6737 val = e;
6738 while (*e) e++;
6739 e++;
6740
ff3187f6 6741 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6742 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6743 ssh2_pkt_addstring(s->pktout, "env");
6744 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6745 ssh2_pkt_addstring_start(s->pktout);
6746 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6747 ssh2_pkt_addstring(s->pktout, val);
6748 ssh2_pkt_send(ssh, s->pktout);
73feed4f 6749
6750 s->num_env++;
6751 }
6752
6753 logeventf(ssh, "Sent %d environment variables", s->num_env);
6754
6755 s->env_ok = 0;
6756 s->env_left = s->num_env;
6757
6758 while (s->env_left > 0) {
b09eaa88 6759 crWaitUntilV(pktin);
73feed4f 6760
ff3187f6 6761 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6762 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 6763 bombout(("Unexpected response to environment request:"
ff3187f6 6764 " packet type %d", pktin->type));
73feed4f 6765 crStopV;
6766 }
6767 } else {
6768 s->env_ok++;
6769 }
6770
6771 s->env_left--;
6772 }
6773
6774 if (s->env_ok == s->num_env) {
6775 logevent("All environment variables successfully set");
6776 } else if (s->env_ok == 0) {
6777 logevent("All environment variables refused");
6778 c_write_str(ssh, "Server refused to set environment variables\r\n");
6779 } else {
6780 logeventf(ssh, "%d environment variables refused",
6781 s->num_env - s->env_ok);
6782 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6783 }
6784 }
6785
6786 /*
fd5e5847 6787 * Start a shell or a remote command. We may have to attempt
6788 * this twice if the config data has provided a second choice
6789 * of command.
7cca0d81 6790 */
0ed48730 6791 if (ssh->mainchan) while (1) {
fd5e5847 6792 int subsys;
6793 char *cmd;
6794
51470298 6795 if (ssh->fallback_cmd) {
86916870 6796 subsys = ssh->cfg.ssh_subsys2;
6797 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 6798 } else {
86916870 6799 subsys = ssh->cfg.ssh_subsys;
6800 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 6801 }
6802
ff3187f6 6803 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6804 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 6805 if (subsys) {
ff3187f6 6806 ssh2_pkt_addstring(s->pktout, "subsystem");
6807 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6808 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6809 } else if (*cmd) {
ff3187f6 6810 ssh2_pkt_addstring(s->pktout, "exec");
6811 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6812 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6813 } else {
ff3187f6 6814 ssh2_pkt_addstring(s->pktout, "shell");
6815 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 6816 }
ff3187f6 6817 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 6818
6819 crWaitUntilV(pktin);
6820
ff3187f6 6821 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6822 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6823 bombout(("Unexpected response to shell/command request:"
ff3187f6 6824 " packet type %d", pktin->type));
7ffdbc1a 6825 crStopV;
fd5e5847 6826 }
6827 /*
6828 * We failed to start the command. If this is the
6829 * fallback command, we really are finished; if it's
6830 * not, and if the fallback command exists, try falling
6831 * back to it before complaining.
6832 */
86916870 6833 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 6834 logevent("Primary command failed; attempting fallback");
51470298 6835 ssh->fallback_cmd = TRUE;
fd5e5847 6836 continue;
6837 }
6b5cf8b4 6838 bombout(("Server refused to start a shell/command"));
7ffdbc1a 6839 crStopV;
fd5e5847 6840 } else {
6841 logevent("Started a shell/command");
32874aea 6842 }
fd5e5847 6843 break;
7cca0d81 6844 }
6845
51470298 6846 ssh->state = SSH_STATE_SESSION;
6847 if (ssh->size_needed)
6848 ssh_size(ssh, ssh->term_width, ssh->term_height);
6849 if (ssh->eof_needed)
6850 ssh_special(ssh, TS_EOF);
6e48c3fe 6851
7cca0d81 6852 /*
6853 * Transfer data!
6854 */
b9d7bcad 6855 if (ssh->ldisc)
6856 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 6857 if (ssh->mainchan)
6858 ssh->send_ok = 1;
7cca0d81 6859 while (1) {
e5574168 6860 crReturnV;
51470298 6861 s->try_send = FALSE;
ff3187f6 6862 if (pktin) {
2b7540a7 6863
51df0ab5 6864 /*
6865 * _All_ the connection-layer packets we expect to
6866 * receive are now handled by the dispatch table.
6867 * Anything that reaches here must be bogus.
6868 */
32874aea 6869
51df0ab5 6870 bombout(("Strange packet received: type %d", pktin->type));
6871 crStopV;
0ed48730 6872 } else if (ssh->mainchan) {
32874aea 6873 /*
6874 * We have spare data. Add it to the channel buffer.
6875 */
d8baa528 6876 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 6877 s->try_send = TRUE;
32874aea 6878 }
51470298 6879 if (s->try_send) {
32874aea 6880 int i;
6881 struct ssh_channel *c;
6882 /*
6883 * Try to send data on all channels if we can.
6884 */
51470298 6885 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 6886 int bufsize;
6887 if (c->closes)
6888 continue; /* don't send on closing channels */
6889 bufsize = ssh2_try_send(c);
5471d09a 6890 if (bufsize == 0) {
6891 switch (c->type) {
6892 case CHAN_MAINSESSION:
6893 /* stdin need not receive an unthrottle
6894 * notification since it will be polled */
6895 break;
6896 case CHAN_X11:
6897 x11_unthrottle(c->u.x11.s);
6898 break;
6899 case CHAN_AGENT:
6900 /* agent sockets are request/response and need no
6901 * buffer management */
6902 break;
6903 case CHAN_SOCKDATA:
6904 pfd_unthrottle(c->u.pfd.s);
6905 break;
6906 }
6907 }
6908 }
7cca0d81 6909 }
e5574168 6910 }
6911
6912 crFinishV;
6913}
6914
6915/*
b09eaa88 6916 * Handlers for SSH2 messages that might arrive at any moment.
6917 */
6918void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
6919{
6920 /* log reason code in disconnect message */
6921 char *buf, *msg;
6922 int nowlen, reason, msglen;
6923
6924 reason = ssh_pkt_getuint32(pktin);
6925 ssh_pkt_getstring(pktin, &msg, &msglen);
6926
6927 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
6928 buf = dupprintf("Received disconnect message (%s)",
6929 ssh2_disconnect_reasons[reason]);
6930 } else {
6931 buf = dupprintf("Received disconnect message (unknown"
6932 " type %d)", reason);
6933 }
6934 logevent(buf);
6935 sfree(buf);
6936 buf = dupprintf("Disconnection message text: %n%.*s",
6937 &nowlen, msglen, msg);
6938 logevent(buf);
6939 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
6940 reason,
6941 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
6942 ssh2_disconnect_reasons[reason] : "unknown",
6943 buf+nowlen));
6944 sfree(buf);
6945}
6946
6947void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
6948{
6949 /* log the debug message */
6950 char *buf, *msg;
6951 int msglen;
6952 int always_display;
6953
6954 /* XXX maybe we should actually take notice of this */
6955 always_display = ssh2_pkt_getbool(pktin);
6956 ssh_pkt_getstring(pktin, &msg, &msglen);
6957
6958 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
6959 logevent(buf);
6960 sfree(buf);
6961}
6962
6963void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
6964{
6965 struct Packet *pktout;
6966 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
6967 ssh2_pkt_adduint32(pktout, pktin->sequence);
6968 /*
6969 * UNIMPLEMENTED messages MUST appear in the same order as the
6970 * messages they respond to. Hence, never queue them.
6971 */
6972 ssh2_pkt_send_noqueue(ssh, pktout);
6973}
6974
6975/*
7cca0d81 6976 * Handle the top-level SSH2 protocol.
6977 */
b09eaa88 6978static void ssh2_protocol_setup(Ssh ssh)
6979{
6980 int i;
6981
6982 /*
6983 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
6984 */
6985 for (i = 0; i < 256; i++)
6986 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
6987
6988 /*
6989 * Any message we actually understand, we set to NULL so that
6990 * the coroutines will get it.
6991 */
6992 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
6993 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
6994 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
6995 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
6996 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
6997 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
6998 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
6999 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7000 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7001 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7002 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7003 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7004 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7005 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7006 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7007 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7008 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7009 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7010 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7011 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7012 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7013 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7014 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7015 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7016 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7017 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7018 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7019 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7020 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7021 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7022 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7023 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7024 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7025
7026 /*
7027 * These special message types we install handlers for.
7028 */
7029 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7030 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7031 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7032}
7033
9442dd57 7034static void ssh2_timer(void *ctx, long now)
7035{
7036 Ssh ssh = (Ssh)ctx;
7037
7038 if (!ssh->kex_in_progress &&
7039 now - ssh->next_rekey >= 0) {
7040 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7041 -1, NULL);
7042 }
7043}
7044
ff3187f6 7045static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7046 struct Packet *pktin)
7cca0d81 7047{
b09eaa88 7048 if (ssh->state == SSH_STATE_CLOSED)
7049 return;
7050
9442dd57 7051 if (pktin) {
7052 ssh->incoming_data_size += pktin->encrypted_len;
7053 if (!ssh->kex_in_progress &&
7054 ssh->incoming_data_size > MAX_DATA_BEFORE_REKEY)
7055 do_ssh2_transport(ssh, "Initiating key re-exchange "
7056 "(too much data received)", -1, NULL);
7057 }
7058
b09eaa88 7059 if (pktin && ssh->packet_dispatch[pktin->type]) {
7060 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7061 return;
b09eaa88 7062 }
7063
7064 if (!ssh->protocol_initial_phase_done ||
7065 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7066 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7067 !ssh->protocol_initial_phase_done) {
7068 ssh->protocol_initial_phase_done = TRUE;
7069 /*
7070 * Allow authconn to initialise itself.
7071 */
7072 do_ssh2_authconn(ssh, NULL, 0, NULL);
7073 }
7074 } else {
7075 do_ssh2_authconn(ssh, in, inlen, pktin);
7076 }
7cca0d81 7077}
7078
7079/*
8df7a775 7080 * Called to set up the connection.
374330e2 7081 *
7082 * Returns an error message, or NULL on success.
374330e2 7083 */
cbe2d68f 7084static const char *ssh_init(void *frontend_handle, void **backend_handle,
7085 Config *cfg,
79bf227b 7086 char *host, int port, char **realhost, int nodelay,
7087 int keepalive)
32874aea 7088{
cbe2d68f 7089 const char *p;
51470298 7090 Ssh ssh;
7091
3d88e64d 7092 ssh = snew(struct ssh_tag);
86916870 7093 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7094 ssh->version = 0; /* when not ready yet */
51470298 7095 ssh->s = NULL;
7096 ssh->cipher = NULL;
371e569c 7097 ssh->v1_cipher_ctx = NULL;
0183b242 7098 ssh->crcda_ctx = NULL;
51470298 7099 ssh->cscipher = NULL;
371e569c 7100 ssh->cs_cipher_ctx = NULL;
51470298 7101 ssh->sccipher = NULL;
371e569c 7102 ssh->sc_cipher_ctx = NULL;
51470298 7103 ssh->csmac = NULL;
a8327734 7104 ssh->cs_mac_ctx = NULL;
51470298 7105 ssh->scmac = NULL;
e0e1a00d 7106 ssh->sc_mac_ctx = NULL;
51470298 7107 ssh->cscomp = NULL;
5366aed8 7108 ssh->cs_comp_ctx = NULL;
51470298 7109 ssh->sccomp = NULL;
5366aed8 7110 ssh->sc_comp_ctx = NULL;
51470298 7111 ssh->kex = NULL;
389aa499 7112 ssh->kex_ctx = NULL;
51470298 7113 ssh->hostkey = NULL;
7114 ssh->exitcode = -1;
7115 ssh->state = SSH_STATE_PREPACKET;
7116 ssh->size_needed = FALSE;
7117 ssh->eof_needed = FALSE;
b9d7bcad 7118 ssh->ldisc = NULL;
a8327734 7119 ssh->logctx = NULL;
51470298 7120 ssh->deferred_send_data = NULL;
7121 ssh->deferred_len = 0;
7122 ssh->deferred_size = 0;
7123 ssh->fallback_cmd = 0;
7124 ssh->pkt_ctx = 0;
302121de 7125 ssh->x11auth = NULL;
be738459 7126 ssh->v1_compressing = FALSE;
51470298 7127 ssh->v2_outgoing_sequence = 0;
7128 ssh->ssh1_rdpkt_crstate = 0;
7129 ssh->ssh2_rdpkt_crstate = 0;
7130 ssh->do_ssh_init_crstate = 0;
7131 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7132 ssh->do_ssh1_connection_crstate = 0;
51470298 7133 ssh->do_ssh1_login_crstate = 0;
7134 ssh->do_ssh2_transport_crstate = 0;
7135 ssh->do_ssh2_authconn_crstate = 0;
7136 ssh->do_ssh_init_state = NULL;
7137 ssh->do_ssh1_login_state = NULL;
7138 ssh->do_ssh2_transport_state = NULL;
7139 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7140 ssh->mainchan = NULL;
968d2d92 7141 ssh->throttled_all = 0;
7142 ssh->v1_stdout_throttling = 0;
590f6a5f 7143 ssh->queue = NULL;
7144 ssh->queuelen = ssh->queuesize = 0;
7145 ssh->queueing = FALSE;
51470298 7146
7147 *backend_handle = ssh;
32874aea 7148
8f203108 7149#ifdef MSCRYPTOAPI
32874aea 7150 if (crypto_startup() == 0)
8f203108 7151 return "Microsoft high encryption pack not installed!";
7152#endif
374330e2 7153
51470298 7154 ssh->frontend = frontend_handle;
86916870 7155 ssh->term_width = ssh->cfg.width;
7156 ssh->term_height = ssh->cfg.height;
887035a5 7157
fabd1805 7158 ssh->channels = NULL;
7159 ssh->rportfwds = NULL;
7160
51470298 7161 ssh->send_ok = 0;
7162 ssh->editing = 0;
7163 ssh->echoing = 0;
7164 ssh->v1_throttle_count = 0;
7165 ssh->overall_bufsize = 0;
7166 ssh->fallback_cmd = 0;
8df7a775 7167
3648d4c5 7168 ssh->protocol = NULL;
7169
b09eaa88 7170 ssh->protocol_initial_phase_done = FALSE;
7171
39934deb 7172 ssh->pinger = NULL;
7173
9442dd57 7174 ssh->incoming_data_size = ssh->outgoing_data_size =
7175 ssh->deferred_data_size = 0L;
7176 ssh->kex_in_progress = FALSE;
7177
79bf227b 7178 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7179 if (p != NULL)
7180 return p;
374330e2 7181
5d17ccfc 7182 random_ref();
7183
374330e2 7184 return NULL;
7185}
7186
fabd1805 7187static void ssh_free(void *handle)
7188{
7189 Ssh ssh = (Ssh) handle;
7190 struct ssh_channel *c;
7191 struct ssh_rportfwd *pf;
7192
7193 if (ssh->v1_cipher_ctx)
7194 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7195 if (ssh->cs_cipher_ctx)
7196 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7197 if (ssh->sc_cipher_ctx)
7198 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7199 if (ssh->cs_mac_ctx)
7200 ssh->csmac->free_context(ssh->cs_mac_ctx);
7201 if (ssh->sc_mac_ctx)
7202 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7203 if (ssh->cs_comp_ctx) {
7204 if (ssh->cscomp)
7205 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7206 else
7207 zlib_compress_cleanup(ssh->cs_comp_ctx);
7208 }
7209 if (ssh->sc_comp_ctx) {
7210 if (ssh->sccomp)
7211 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7212 else
7213 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7214 }
fabd1805 7215 if (ssh->kex_ctx)
7216 dh_cleanup(ssh->kex_ctx);
7217 sfree(ssh->savedhost);
7218
590f6a5f 7219 while (ssh->queuelen-- > 0)
7220 ssh_free_packet(ssh->queue[ssh->queuelen]);
7221 sfree(ssh->queue);
7222
fabd1805 7223 if (ssh->channels) {
7224 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7225 switch (c->type) {
7226 case CHAN_X11:
7227 if (c->u.x11.s != NULL)
7228 x11_close(c->u.x11.s);
7229 break;
7230 case CHAN_SOCKDATA:
7231 if (c->u.pfd.s != NULL)
7232 pfd_close(c->u.pfd.s);
7233 break;
7234 }
7235 sfree(c);
7236 }
7237 freetree234(ssh->channels);
7238 }
7239
7240 if (ssh->rportfwds) {
7241 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7242 sfree(pf);
7243 freetree234(ssh->rportfwds);
7244 }
7245 sfree(ssh->deferred_send_data);
7246 if (ssh->x11auth)
7247 x11_free_auth(ssh->x11auth);
7248 sfree(ssh->do_ssh_init_state);
7249 sfree(ssh->do_ssh1_login_state);
7250 sfree(ssh->do_ssh2_transport_state);
7251 sfree(ssh->do_ssh2_authconn_state);
679539d7 7252 if (ssh->crcda_ctx) {
7253 crcda_free_context(ssh->crcda_ctx);
7254 ssh->crcda_ctx = NULL;
7255 }
fabd1805 7256 if (ssh->s)
36f94d1f 7257 ssh_do_close(ssh);
9442dd57 7258 expire_timer_context(ssh);
fabd1805 7259 sfree(ssh);
39934deb 7260 if (ssh->pinger)
7261 pinger_free(ssh->pinger);
5d17ccfc 7262
7263 random_unref();
fabd1805 7264}
7265
374330e2 7266/*
86916870 7267 * Reconfigure the SSH backend.
7268 *
7269 * Currently, this function does nothing very useful. In future,
7270 * however, we could do some handy things with it. For example, we
7271 * could make the port forwarding configurer active in the Change
7272 * Settings box, and this routine could close down existing
7273 * forwardings and open up new ones in response to changes.
7274 */
7275static void ssh_reconfig(void *handle, Config *cfg)
7276{
7277 Ssh ssh = (Ssh) handle;
39934deb 7278 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
86916870 7279 ssh->cfg = *cfg; /* STRUCTURE COPY */
7280}
7281
7282/*
374330e2 7283 * Called to send data down the Telnet connection.
7284 */
51470298 7285static int ssh_send(void *handle, char *buf, int len)
32874aea 7286{
51470298 7287 Ssh ssh = (Ssh) handle;
7288
7289 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7290 return 0;
374330e2 7291
d8baa528 7292 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7293
51470298 7294 return ssh_sendbuffer(ssh);
5471d09a 7295}
7296
7297/*
7298 * Called to query the current amount of buffered stdin data.
7299 */
51470298 7300static int ssh_sendbuffer(void *handle)
5471d09a 7301{
51470298 7302 Ssh ssh = (Ssh) handle;
5471d09a 7303 int override_value;
7304
51470298 7305 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7306 return 0;
7307
7308 /*
7309 * If the SSH socket itself has backed up, add the total backup
7310 * size on that to any individual buffer on the stdin channel.
7311 */
7312 override_value = 0;
51470298 7313 if (ssh->throttled_all)
7314 override_value = ssh->overall_bufsize;
5471d09a 7315
51470298 7316 if (ssh->version == 1) {
5471d09a 7317 return override_value;
51470298 7318 } else if (ssh->version == 2) {
7319 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7320 return override_value;
7321 else
51470298 7322 return (override_value +
7323 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7324 }
7325
7326 return 0;
374330e2 7327}
7328
7329/*
6e48c3fe 7330 * Called to set the size of the window from SSH's POV.
374330e2 7331 */
51470298 7332static void ssh_size(void *handle, int width, int height)
32874aea 7333{
51470298 7334 Ssh ssh = (Ssh) handle;
ff3187f6 7335 struct Packet *pktout;
51470298 7336
7337 ssh->term_width = width;
7338 ssh->term_height = height;
f278d6f8 7339
51470298 7340 switch (ssh->state) {
374330e2 7341 case SSH_STATE_BEFORE_SIZE:
3687d221 7342 case SSH_STATE_PREPACKET:
21248260 7343 case SSH_STATE_CLOSED:
374330e2 7344 break; /* do nothing */
7345 case SSH_STATE_INTERMED:
51470298 7346 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7347 break;
7348 case SSH_STATE_SESSION:
86916870 7349 if (!ssh->cfg.nopty) {
51470298 7350 if (ssh->version == 1) {
7351 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7352 PKT_INT, ssh->term_height,
7353 PKT_INT, ssh->term_width,
32874aea 7354 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7355 } else if (ssh->mainchan) {
ff3187f6 7356 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7357 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7358 ssh2_pkt_addstring(pktout, "window-change");
7359 ssh2_pkt_addbool(pktout, 0);
7360 ssh2_pkt_adduint32(pktout, ssh->term_width);
7361 ssh2_pkt_adduint32(pktout, ssh->term_height);
7362 ssh2_pkt_adduint32(pktout, 0);
7363 ssh2_pkt_adduint32(pktout, 0);
7364 ssh2_pkt_send(ssh, pktout);
32874aea 7365 }
7366 }
7367 break;
374330e2 7368 }
7369}
7370
7371/*
125105d1 7372 * Return a list of the special codes that make sense in this
7373 * protocol.
7374 */
7375static const struct telnet_special *ssh_get_specials(void *handle)
7376{
62638676 7377 static const struct telnet_special ignore_special[] = {
7378 {"IGNORE message", TS_NOP},
9442dd57 7379 {"Repeat key exchange", TS_REKEY},
62638676 7380 };
7381 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7382 {NULL, TS_SEP},
7383 {"Break", TS_BRK},
7384 /* These are the signal names defined by draft-ietf-secsh-connect-19.
7385 * They include all the ISO C signals, but are a subset of the POSIX
7386 * required signals. */
7387 {"SIGINT (Interrupt)", TS_SIGINT},
7388 {"SIGTERM (Terminate)", TS_SIGTERM},
7389 {"SIGKILL (Kill)", TS_SIGKILL},
7390 {"SIGQUIT (Quit)", TS_SIGQUIT},
7391 {"SIGHUP (Hangup)", TS_SIGHUP},
7392 {"More signals", TS_SUBMENU},
7393 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7394 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7395 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7396 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7397 {NULL, TS_EXITMENU}
62638676 7398 };
7399 static const struct telnet_special specials_end[] = {
6f2d0cde 7400 {NULL, TS_EXITMENU}
62638676 7401 };
7402 static struct telnet_special ssh_specials[lenof(ignore_special) +
7403 lenof(ssh2_session_specials) +
7404 lenof(specials_end)];
125105d1 7405 Ssh ssh = (Ssh) handle;
62638676 7406 int i = 0;
7407#define ADD_SPECIALS(name) \
7408 do { \
7409 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7410 memcpy(&ssh_specials[i], name, sizeof name); \
7411 i += lenof(name); \
7412 } while(0)
125105d1 7413
7414 if (ssh->version == 1) {
62638676 7415 /* Don't bother offering IGNORE if we've decided the remote
7416 * won't cope with it, since we wouldn't bother sending it if
7417 * asked anyway. */
7418 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7419 ADD_SPECIALS(ignore_special);
125105d1 7420 } else if (ssh->version == 2) {
62638676 7421 ADD_SPECIALS(ignore_special);
7422 if (ssh->mainchan)
7423 ADD_SPECIALS(ssh2_session_specials);
7424 } /* else we're not ready yet */
7425
7426 if (i) {
7427 ADD_SPECIALS(specials_end);
7428 return ssh_specials;
7429 } else {
125105d1 7430 return NULL;
62638676 7431 }
7432#undef ADD_SPECIALS
125105d1 7433}
7434
7435/*
6abbf9e3 7436 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7437 * can send an EOF and collect resulting output (e.g. `plink
7438 * hostname sort').
374330e2 7439 */
51470298 7440static void ssh_special(void *handle, Telnet_Special code)
32874aea 7441{
51470298 7442 Ssh ssh = (Ssh) handle;
ff3187f6 7443 struct Packet *pktout;
51470298 7444
6abbf9e3 7445 if (code == TS_EOF) {
51470298 7446 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7447 /*
7448 * Buffer the EOF in case we are pre-SESSION, so we can
7449 * send it as soon as we reach SESSION.
7450 */
7451 if (code == TS_EOF)
51470298 7452 ssh->eof_needed = TRUE;
32874aea 7453 return;
7454 }
51470298 7455 if (ssh->version == 1) {
7456 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7457 } else if (ssh->mainchan) {
ff3187f6 7458 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7459 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7460 ssh2_pkt_send(ssh, pktout);
32874aea 7461 }
7462 logevent("Sent EOF message");
125105d1 7463 } else if (code == TS_PING || code == TS_NOP) {
51470298 7464 if (ssh->state == SSH_STATE_CLOSED
7465 || ssh->state == SSH_STATE_PREPACKET) return;
7466 if (ssh->version == 1) {
7467 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7468 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7469 } else {
ff3187f6 7470 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7471 ssh2_pkt_addstring_start(pktout);
590f6a5f 7472 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7473 }
9442dd57 7474 } else if (code == TS_REKEY) {
7475 if (!ssh->kex_in_progress && ssh->version == 2) {
7476 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7477 " user request", -1, NULL);
7478 }
125105d1 7479 } else if (code == TS_BRK) {
7480 if (ssh->state == SSH_STATE_CLOSED
7481 || ssh->state == SSH_STATE_PREPACKET) return;
7482 if (ssh->version == 1) {
7483 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7484 } else if (ssh->mainchan) {
ff3187f6 7485 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7486 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7487 ssh2_pkt_addstring(pktout, "break");
7488 ssh2_pkt_addbool(pktout, 0);
7489 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7490 ssh2_pkt_send(ssh, pktout);
125105d1 7491 }
6abbf9e3 7492 } else {
6f2d0cde 7493 /* Is is a POSIX signal? */
7494 char *signame = NULL;
7495 if (code == TS_SIGABRT) signame = "ABRT";
7496 if (code == TS_SIGALRM) signame = "ALRM";
7497 if (code == TS_SIGFPE) signame = "FPE";
7498 if (code == TS_SIGHUP) signame = "HUP";
7499 if (code == TS_SIGILL) signame = "ILL";
7500 if (code == TS_SIGINT) signame = "INT";
7501 if (code == TS_SIGKILL) signame = "KILL";
7502 if (code == TS_SIGPIPE) signame = "PIPE";
7503 if (code == TS_SIGQUIT) signame = "QUIT";
7504 if (code == TS_SIGSEGV) signame = "SEGV";
7505 if (code == TS_SIGTERM) signame = "TERM";
7506 if (code == TS_SIGUSR1) signame = "USR1";
7507 if (code == TS_SIGUSR2) signame = "USR2";
7508 /* The SSH-2 protocol does in principle support arbitrary named
7509 * signals, including signame@domain, but we don't support those. */
7510 if (signame) {
7511 /* It's a signal. */
7512 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7513 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7514 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7515 ssh2_pkt_addstring(pktout, "signal");
7516 ssh2_pkt_addbool(pktout, 0);
7517 ssh2_pkt_addstring(pktout, signame);
7518 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7519 logeventf(ssh, "Sent signal SIG%s", signame);
7520 }
7521 } else {
7522 /* Never heard of it. Do nothing */
7523 }
6abbf9e3 7524 }
374330e2 7525}
7526
51470298 7527void *new_sock_channel(void *handle, Socket s)
d74d141c 7528{
51470298 7529 Ssh ssh = (Ssh) handle;
d74d141c 7530 struct ssh_channel *c;
3d88e64d 7531 c = snew(struct ssh_channel);
51470298 7532 c->ssh = ssh;
d74d141c 7533
7534 if (c) {
bc240b21 7535 c->remoteid = -1; /* to be set when open confirmed */
51470298 7536 c->localid = alloc_channel_id(ssh);
d74d141c 7537 c->closes = 0;
bc240b21 7538 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7539 c->u.pfd.s = s;
013dd8c0 7540 bufchain_init(&c->v.v2.outbuffer);
51470298 7541 add234(ssh->channels, c);
d74d141c 7542 }
7543 return c;
7544}
7545
5471d09a 7546/*
7547 * This is called when stdout/stderr (the entity to which
7548 * from_backend sends data) manages to clear some backlog.
7549 */
ae9ae89f 7550static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7551{
51470298 7552 Ssh ssh = (Ssh) handle;
7553 if (ssh->version == 1) {
7554 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7555 ssh->v1_stdout_throttling = 0;
7556 ssh1_throttle(ssh, -1);
5471d09a 7557 }
7558 } else {
51470298 7559 if (ssh->mainchan && ssh->mainchan->closes == 0)
7560 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7561 }
7562}
7563
6b78788a 7564void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7565{
7566 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7567 Ssh ssh = c->ssh;
ff3187f6 7568 struct Packet *pktout;
d74d141c 7569
57356d63 7570 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7571
51470298 7572 if (ssh->version == 1) {
7573 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7574 PKT_INT, c->localid,
7575 PKT_STR, hostname,
7576 PKT_INT, port,
7577 //PKT_STR, <org:orgport>,
7578 PKT_END);
7579 } else {
ff3187f6 7580 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7581 ssh2_pkt_addstring(pktout, "direct-tcpip");
7582 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7583 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7584 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7585 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7586 ssh2_pkt_addstring(pktout, hostname);
7587 ssh2_pkt_adduint32(pktout, port);
bc240b21 7588 /*
7589 * We make up values for the originator data; partly it's
7590 * too much hassle to keep track, and partly I'm not
7591 * convinced the server should be told details like that
7592 * about my local network configuration.
7593 */
ff3187f6 7594 ssh2_pkt_addstring(pktout, "client-side-connection");
7595 ssh2_pkt_adduint32(pktout, 0);
7596 ssh2_pkt_send(ssh, pktout);
bc240b21 7597 }
d74d141c 7598}
7599
51470298 7600static Socket ssh_socket(void *handle)
32874aea 7601{
51470298 7602 Ssh ssh = (Ssh) handle;
7603 return ssh->s;
32874aea 7604}
8ccc75b0 7605
51470298 7606static int ssh_sendok(void *handle)
32874aea 7607{
51470298 7608 Ssh ssh = (Ssh) handle;
7609 return ssh->send_ok;
32874aea 7610}
fb09bf1c 7611
51470298 7612static int ssh_ldisc(void *handle, int option)
32874aea 7613{
51470298 7614 Ssh ssh = (Ssh) handle;
32874aea 7615 if (option == LD_ECHO)
51470298 7616 return ssh->echoing;
32874aea 7617 if (option == LD_EDIT)
51470298 7618 return ssh->editing;
0965bee0 7619 return FALSE;
7620}
7621
b9d7bcad 7622static void ssh_provide_ldisc(void *handle, void *ldisc)
7623{
7624 Ssh ssh = (Ssh) handle;
7625 ssh->ldisc = ldisc;
7626}
7627
a8327734 7628static void ssh_provide_logctx(void *handle, void *logctx)
7629{
7630 Ssh ssh = (Ssh) handle;
7631 ssh->logctx = logctx;
7632}
7633
51470298 7634static int ssh_return_exitcode(void *handle)
7635{
7636 Ssh ssh = (Ssh) handle;
3bb2f322 7637 if (ssh->s != NULL)
7638 return -1;
7639 else
7640 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7641}
7642
7643/*
7644 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7645 * that fails. This variable is the means by which scp.c can reach
7646 * into the SSH code and find out which one it got.
7647 */
7648extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7649{
51470298 7650 Ssh ssh = (Ssh) handle;
7651 return ssh->fallback_cmd;
d8d6c7e5 7652}
7653
374330e2 7654Backend ssh_backend = {
7655 ssh_init,
fabd1805 7656 ssh_free,
86916870 7657 ssh_reconfig,
374330e2 7658 ssh_send,
5471d09a 7659 ssh_sendbuffer,
374330e2 7660 ssh_size,
4017be6d 7661 ssh_special,
125105d1 7662 ssh_get_specials,
8ccc75b0 7663 ssh_socket,
d8d6c7e5 7664 ssh_return_exitcode,
97db3be4 7665 ssh_sendok,
0965bee0 7666 ssh_ldisc,
b9d7bcad 7667 ssh_provide_ldisc,
a8327734 7668 ssh_provide_logctx,
5471d09a 7669 ssh_unthrottle,
97db3be4 7670 22
bc240b21 7671};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator