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Versions of OpenSSH before 2.5.4 kill the connection if the client attempts
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5
6#include "putty.h"
dacbd0e8 7#include "tree234.h"
fb09bf1c 8#include "ssh.h"
374330e2 9
10#ifndef FALSE
11#define FALSE 0
12#endif
13#ifndef TRUE
14#define TRUE 1
15#endif
16
32874aea 17#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20#define SSH1_CMSG_USER 4 /* 0x4 */
21#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29#define SSH1_SMSG_SUCCESS 14 /* 0xe */
30#define SSH1_SMSG_FAILURE 15 /* 0xf */
31#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34#define SSH1_CMSG_EOF 19 /* 0x13 */
35#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46#define SSH1_MSG_IGNORE 32 /* 0x20 */
47#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50#define SSH1_MSG_DEBUG 36 /* 0x24 */
51#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
58
59#define SSH1_AUTH_TIS 5 /* 0x5 */
60#define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 63/* Mask for protoflags we will echo back to server if seen */
32874aea 64#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
66#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67#define SSH2_MSG_IGNORE 2 /* 0x2 */
68#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69#define SSH2_MSG_DEBUG 4 /* 0x4 */
70#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72#define SSH2_MSG_KEXINIT 20 /* 0x14 */
73#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 86#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 88#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
102
00db133f 103/*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
d1aaf71d 107#define SSH2_PKTCTX_DHGROUP 0x0001
00db133f 108#define SSH2_PKTCTX_DHGEX 0x0002
149d2abc 109#define SSH2_PKTCTX_KEX_MASK 0x000F
00db133f 110#define SSH2_PKTCTX_PUBLICKEY 0x0010
111#define SSH2_PKTCTX_PASSWORD 0x0020
112#define SSH2_PKTCTX_KBDINTER 0x0040
113#define SSH2_PKTCTX_AUTH_MASK 0x00F0
114
32874aea 115#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 130
131static const char *const ssh2_disconnect_reasons[] = {
132 NULL,
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
148};
9005f3ba 149
32874aea 150#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 154
32874aea 155#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 156
7d503c31 157/*
158 * Various remote-bug flags.
159 */
160#define BUG_CHOKES_ON_SSH1_IGNORE 1
161#define BUG_SSH2_HMAC 2
bd358db1 162#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 163#define BUG_CHOKES_ON_RSA 8
1dd353b5 164#define BUG_SSH2_RSA_PADDING 16
088bde77 165#define BUG_SSH2_DERIVEKEY 32
f382c87d 166#define BUG_SSH2_REKEY 64
dda87a28 167#define BUG_SSH2_PK_SESSIONID 128
bd358db1 168
00db133f 169#define translate(x) if (type == x) return #x
51470298 170#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
ae9ae89f 171static char *ssh1_pkt_type(int type)
00db133f 172{
173 translate(SSH1_MSG_DISCONNECT);
174 translate(SSH1_SMSG_PUBLIC_KEY);
175 translate(SSH1_CMSG_SESSION_KEY);
176 translate(SSH1_CMSG_USER);
177 translate(SSH1_CMSG_AUTH_RSA);
178 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
179 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
180 translate(SSH1_CMSG_AUTH_PASSWORD);
181 translate(SSH1_CMSG_REQUEST_PTY);
182 translate(SSH1_CMSG_WINDOW_SIZE);
183 translate(SSH1_CMSG_EXEC_SHELL);
184 translate(SSH1_CMSG_EXEC_CMD);
185 translate(SSH1_SMSG_SUCCESS);
186 translate(SSH1_SMSG_FAILURE);
187 translate(SSH1_CMSG_STDIN_DATA);
188 translate(SSH1_SMSG_STDOUT_DATA);
189 translate(SSH1_SMSG_STDERR_DATA);
190 translate(SSH1_CMSG_EOF);
191 translate(SSH1_SMSG_EXIT_STATUS);
192 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
193 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
194 translate(SSH1_MSG_CHANNEL_DATA);
195 translate(SSH1_MSG_CHANNEL_CLOSE);
196 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
197 translate(SSH1_SMSG_X11_OPEN);
198 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
199 translate(SSH1_MSG_PORT_OPEN);
200 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
201 translate(SSH1_SMSG_AGENT_OPEN);
202 translate(SSH1_MSG_IGNORE);
203 translate(SSH1_CMSG_EXIT_CONFIRMATION);
204 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
205 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
206 translate(SSH1_MSG_DEBUG);
207 translate(SSH1_CMSG_REQUEST_COMPRESSION);
208 translate(SSH1_CMSG_AUTH_TIS);
209 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
210 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
211 translate(SSH1_CMSG_AUTH_CCARD);
212 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
213 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
214 return "unknown";
215}
ae9ae89f 216static char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 217{
218 translate(SSH2_MSG_DISCONNECT);
219 translate(SSH2_MSG_IGNORE);
220 translate(SSH2_MSG_UNIMPLEMENTED);
221 translate(SSH2_MSG_DEBUG);
222 translate(SSH2_MSG_SERVICE_REQUEST);
223 translate(SSH2_MSG_SERVICE_ACCEPT);
224 translate(SSH2_MSG_KEXINIT);
225 translate(SSH2_MSG_NEWKEYS);
d1aaf71d 226 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
227 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
00db133f 228 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
231 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
232 translate(SSH2_MSG_USERAUTH_REQUEST);
233 translate(SSH2_MSG_USERAUTH_FAILURE);
234 translate(SSH2_MSG_USERAUTH_SUCCESS);
235 translate(SSH2_MSG_USERAUTH_BANNER);
236 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
237 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
238 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
239 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
240 translate(SSH2_MSG_GLOBAL_REQUEST);
241 translate(SSH2_MSG_REQUEST_SUCCESS);
242 translate(SSH2_MSG_REQUEST_FAILURE);
243 translate(SSH2_MSG_CHANNEL_OPEN);
244 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
245 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
246 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
247 translate(SSH2_MSG_CHANNEL_DATA);
248 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
249 translate(SSH2_MSG_CHANNEL_EOF);
250 translate(SSH2_MSG_CHANNEL_CLOSE);
251 translate(SSH2_MSG_CHANNEL_REQUEST);
252 translate(SSH2_MSG_CHANNEL_SUCCESS);
253 translate(SSH2_MSG_CHANNEL_FAILURE);
254 return "unknown";
255}
256#undef translate
257#undef translatec
7d503c31 258
fb09bf1c 259#define GET_32BIT(cp) \
260 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
261 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
262 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
263 ((unsigned long)(unsigned char)(cp)[3]))
264
265#define PUT_32BIT(cp, value) { \
266 (cp)[0] = (unsigned char)((value) >> 24); \
267 (cp)[1] = (unsigned char)((value) >> 16); \
268 (cp)[2] = (unsigned char)((value) >> 8); \
269 (cp)[3] = (unsigned char)(value); }
270
9a10ecf4 271/* Enumeration values for fields in SSH-1 packets */
272enum {
273 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
274 /* These values are for communicating relevant semantics of
275 * fields to the packet logging code. */
276 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
277};
972a41c8 278
acddebd9 279/*
280 * Coroutine mechanics for the sillier bits of the code. If these
281 * macros look impenetrable to you, you might find it helpful to
282 * read
283 *
284 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
285 *
286 * which explains the theory behind these macros.
b624d1e6 287 *
288 * In particular, if you are getting `case expression not constant'
289 * errors when building with MS Visual Studio, this is because MS's
290 * Edit and Continue debugging feature causes their compiler to
291 * violate ANSI C. To disable Edit and Continue debugging:
292 *
293 * - right-click ssh.c in the FileView
294 * - click Settings
295 * - select the C/C++ tab and the General category
296 * - under `Debug info:', select anything _other_ than `Program
297 * Database for Edit and Continue'.
acddebd9 298 */
51470298 299#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
300#define crState(t) \
301 struct t *s; \
3d88e64d 302 if (!ssh->t) ssh->t = snew(struct t); \
51470298 303 s = ssh->t;
304#define crFinish(z) } *crLine = 0; return (z); }
305#define crFinishV } *crLine = 0; return; }
374330e2 306#define crReturn(z) \
307 do {\
51470298 308 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 309 } while (0)
310#define crReturnV \
311 do {\
51470298 312 *crLine=__LINE__; return; case __LINE__:;\
374330e2 313 } while (0)
51470298 314#define crStop(z) do{ *crLine = 0; return (z); }while(0)
315#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 316#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 317#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 318
51470298 319typedef struct ssh_tag *Ssh;
ff3187f6 320struct Packet;
321
322static struct Packet *ssh2_pkt_init(int pkt_type);
323static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
324static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
325static void ssh2_pkt_addstring_start(struct Packet *);
326static void ssh2_pkt_addstring_str(struct Packet *, char *data);
327static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
328static void ssh2_pkt_addstring(struct Packet *, char *data);
d8baa528 329static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
ff3187f6 330static void ssh2_pkt_addmp(struct Packet *, Bignum b);
331static int ssh2_pkt_construct(Ssh, struct Packet *);
332static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 333static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 334static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
335 struct Packet *pktin);
336static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
337 struct Packet *pktin);
3d63ca2e 338
5471d09a 339/*
340 * Buffer management constants. There are several of these for
341 * various different purposes:
342 *
343 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
344 * on a local data stream before we throttle the whole SSH
345 * connection (in SSH1 only). Throttling the whole connection is
346 * pretty drastic so we set this high in the hope it won't
347 * happen very often.
348 *
349 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
350 * on the SSH connection itself before we defensively throttle
351 * _all_ local data streams. This is pretty drastic too (though
352 * thankfully unlikely in SSH2 since the window mechanism should
353 * ensure that the server never has any need to throttle its end
354 * of the connection), so we set this high as well.
355 *
356 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
357 * channels.
358 */
359
360#define SSH1_BUFFER_LIMIT 32768
361#define SSH_MAX_BACKLOG 32768
362#define OUR_V2_WINSIZE 16384
d74d141c 363
85cc02bb 364const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 365
e0e1a00d 366static void *nullmac_make_context(void)
367{
368 return NULL;
369}
370static void nullmac_free_context(void *handle)
371{
372}
373static void nullmac_key(void *handle, unsigned char *key)
32874aea 374{
375}
e0e1a00d 376static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 377 unsigned long seq)
378{
379}
e0e1a00d 380static int nullmac_verify(void *handle, unsigned char *blk, int len,
381 unsigned long seq)
32874aea 382{
383 return 1;
384}
57476f6b 385const static struct ssh_mac ssh_mac_none = {
e0e1a00d 386 nullmac_make_context, nullmac_free_context, nullmac_key,
387 nullmac_generate, nullmac_verify, "none", 0
e5574168 388};
8b2715b2 389const static struct ssh_mac *macs[] = {
32874aea 390 &ssh_sha1, &ssh_md5, &ssh_mac_none
391};
8b2715b2 392const static struct ssh_mac *buggymacs[] = {
32874aea 393 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
394};
e5574168 395
5366aed8 396static void *ssh_comp_none_init(void)
397{
398 return NULL;
399}
400static void ssh_comp_none_cleanup(void *handle)
32874aea 401{
402}
5366aed8 403static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 404 unsigned char **outblock, int *outlen)
405{
406 return 0;
407}
5366aed8 408static int ssh_comp_none_disable(void *handle)
32874aea 409{
4ba9b64b 410 return 0;
411}
57476f6b 412const static struct ssh_compress ssh_comp_none = {
4ba9b64b 413 "none",
5366aed8 414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
416 ssh_comp_none_disable, NULL
e5574168 417};
4ba9b64b 418extern const struct ssh_compress ssh_zlib;
419const static struct ssh_compress *compressions[] = {
32874aea 420 &ssh_zlib, &ssh_comp_none
421};
374330e2 422
32874aea 423enum { /* channel types */
783415f8 424 CHAN_MAINSESSION,
425 CHAN_X11,
426 CHAN_AGENT,
bc240b21 427 CHAN_SOCKDATA,
428 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 429};
430
dacbd0e8 431/*
432 * 2-3-4 tree storing channels.
433 */
434struct ssh_channel {
51470298 435 Ssh ssh; /* pointer back to main context */
d211621f 436 unsigned remoteid, localid;
dacbd0e8 437 int type;
0357890f 438 /*
439 * In SSH1, this value contains four bits:
440 *
441 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
442 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
443 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
444 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
445 *
446 * A channel is completely finished with when all four bits are set.
447 */
dacbd0e8 448 int closes;
5471d09a 449 union {
450 struct ssh1_data_channel {
451 int throttling;
452 } v1;
453 struct ssh2_data_channel {
454 bufchain outbuffer;
455 unsigned remwindow, remmaxpkt;
456 unsigned locwindow;
457 } v2;
458 } v;
dacbd0e8 459 union {
32874aea 460 struct ssh_agent_channel {
461 unsigned char *message;
462 unsigned char msglen[4];
a03c9f9c 463 unsigned lensofar, totallen;
32874aea 464 } a;
465 struct ssh_x11_channel {
466 Socket s;
467 } x11;
d74d141c 468 struct ssh_pfd_channel {
469 Socket s;
470 } pfd;
dacbd0e8 471 } u;
472};
57476f6b 473
d74d141c 474/*
bc240b21 475 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
476 * 2 use this structure in different ways, reflecting SSH 2's
477 * altogether saner approach to port forwarding.
478 *
479 * In SSH 1, you arrange a remote forwarding by sending the server
480 * the remote port number, and the local destination host:port.
481 * When a connection comes in, the server sends you back that
482 * host:port pair, and you connect to it. This is a ready-made
483 * security hole if you're not on the ball: a malicious server
484 * could send you back _any_ host:port pair, so if you trustingly
485 * connect to the address it gives you then you've just opened the
486 * entire inside of your corporate network just by connecting
487 * through it to a dodgy SSH server. Hence, we must store a list of
488 * host:port pairs we _are_ trying to forward to, and reject a
489 * connection request from the server if it's not in the list.
490 *
491 * In SSH 2, each side of the connection minds its own business and
492 * doesn't send unnecessary information to the other. You arrange a
493 * remote forwarding by sending the server just the remote port
494 * number. When a connection comes in, the server tells you which
495 * of its ports was connected to; and _you_ have to remember what
496 * local host:port pair went with that port number.
497 *
06fadff5 498 * Hence, in SSH 1 this structure is indexed by destination
499 * host:port pair, whereas in SSH 2 it is indexed by source port.
d74d141c 500 */
fda2feb1 501struct ssh_portfwd; /* forward declaration */
502
d74d141c 503struct ssh_rportfwd {
bc240b21 504 unsigned sport, dport;
505 char dhost[256];
06fadff5 506 char *sportdesc;
fda2feb1 507 struct ssh_portfwd *pfrec;
d74d141c 508};
fda2feb1 509#define free_rportfwd(pf) ( \
510 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
511
512/*
513 * Separately to the rportfwd tree (which is for looking up port
514 * open requests from the server), a tree of _these_ structures is
515 * used to keep track of all the currently open port forwardings,
516 * so that we can reconfigure in mid-session if the user requests
517 * it.
518 */
519struct ssh_portfwd {
84328ddb 520 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 521 int type;
522 unsigned sport, dport;
523 char *saddr, *daddr;
3fe92132 524 char *sserv, *dserv;
fda2feb1 525 struct ssh_rportfwd *remote;
05581745 526 int addressfamily;
fda2feb1 527 void *local;
528};
529#define free_portfwd(pf) ( \
3fe92132 530 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
531 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 532
57476f6b 533struct Packet {
534 long length;
535 int type;
b09eaa88 536 unsigned long sequence;
57476f6b 537 unsigned char *data;
538 unsigned char *body;
539 long savedpos;
540 long maxlen;
9442dd57 541 long encrypted_len; /* for SSH2 total-size counting */
ff3187f6 542
543 /*
544 * State associated with packet logging
545 */
546 int logmode;
547 int nblanks;
548 struct logblank_t *blanks;
57476f6b 549};
550
ff3187f6 551static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
552 struct Packet *pktin);
553static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
554 struct Packet *pktin);
b09eaa88 555static void ssh1_protocol_setup(Ssh ssh);
556static void ssh2_protocol_setup(Ssh ssh);
51470298 557static void ssh_size(void *handle, int width, int height);
558static void ssh_special(void *handle, Telnet_Special);
5471d09a 559static int ssh2_try_send(struct ssh_channel *c);
51470298 560static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
561static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 562static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 563static int ssh_sendbuffer(void *handle);
36f94d1f 564static void ssh_do_close(Ssh ssh);
ff3187f6 565static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
566static int ssh2_pkt_getbool(struct Packet *pkt);
567static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 568static void ssh2_timer(void *ctx, long now);
569static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
570 struct Packet *pktin);
57476f6b 571
51470298 572struct rdpkt1_state_tag {
57476f6b 573 long len, pad, biglen, to_read;
574 unsigned long realcrc, gotcrc;
575 unsigned char *p;
576 int i;
577 int chunk;
ff3187f6 578 struct Packet *pktin;
51470298 579};
57476f6b 580
51470298 581struct rdpkt2_state_tag {
960e736a 582 long len, pad, payload, packetlen, maclen;
583 int i;
584 int cipherblk;
585 unsigned long incoming_sequence;
ff3187f6 586 struct Packet *pktin;
51470298 587};
588
b09eaa88 589typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 590typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
591
592struct queued_handler;
593struct queued_handler {
594 int msg1, msg2;
595 chandler_fn_t handler;
596 void *ctx;
597 struct queued_handler *next;
598};
b09eaa88 599
51470298 600struct ssh_tag {
601 const struct plug_function_table *fn;
602 /* the above field _must_ be first in the structure */
603
604 SHA_State exhash, exhashbase;
605
606 Socket s;
607
b9d7bcad 608 void *ldisc;
a8327734 609 void *logctx;
b9d7bcad 610
51470298 611 unsigned char session_key[32];
612 int v1_compressing;
613 int v1_remote_protoflags;
614 int v1_local_protoflags;
615 int agentfwd_enabled;
616 int X11_fwd_enabled;
617 int remote_bugs;
618 const struct ssh_cipher *cipher;
371e569c 619 void *v1_cipher_ctx;
0183b242 620 void *crcda_ctx;
51470298 621 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 622 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 623 const struct ssh_mac *csmac, *scmac;
e0e1a00d 624 void *cs_mac_ctx, *sc_mac_ctx;
51470298 625 const struct ssh_compress *cscomp, *sccomp;
5366aed8 626 void *cs_comp_ctx, *sc_comp_ctx;
51470298 627 const struct ssh_kex *kex;
628 const struct ssh_signkey *hostkey;
629 unsigned char v2_session_id[20];
27cd7fc2 630 void *kex_ctx;
51470298 631
632 char *savedhost;
633 int savedport;
634 int send_ok;
635 int echoing, editing;
636
637 void *frontend;
638
db219738 639 int ospeed, ispeed; /* temporaries */
51470298 640 int term_width, term_height;
641
642 tree234 *channels; /* indexed by local id */
643 struct ssh_channel *mainchan; /* primary session channel */
644 int exitcode;
645
fda2feb1 646 tree234 *rportfwds, *portfwds;
51470298 647
648 enum {
649 SSH_STATE_PREPACKET,
650 SSH_STATE_BEFORE_SIZE,
651 SSH_STATE_INTERMED,
652 SSH_STATE_SESSION,
653 SSH_STATE_CLOSED
654 } state;
655
656 int size_needed, eof_needed;
657
590f6a5f 658 struct Packet **queue;
659 int queuelen, queuesize;
660 int queueing;
51470298 661 unsigned char *deferred_send_data;
662 int deferred_len, deferred_size;
663
664 /*
665 * Gross hack: pscp will try to start SFTP but fall back to
666 * scp1 if that fails. This variable is the means by which
667 * scp.c can reach into the SSH code and find out which one it
668 * got.
669 */
670 int fallback_cmd;
671
672 /*
673 * Used for username and password input.
674 */
675 char *userpass_input_buffer;
676 int userpass_input_buflen;
677 int userpass_input_bufpos;
678 int userpass_input_echo;
679
51470298 680 int pkt_ctx;
681
302121de 682 void *x11auth;
683
51470298 684 int version;
685 int v1_throttle_count;
686 int overall_bufsize;
687 int throttled_all;
688 int v1_stdout_throttling;
689 int v2_outgoing_sequence;
690
691 int ssh1_rdpkt_crstate;
692 int ssh2_rdpkt_crstate;
693 int do_ssh_init_crstate;
694 int ssh_gotdata_crstate;
51470298 695 int do_ssh1_login_crstate;
b09eaa88 696 int do_ssh1_connection_crstate;
51470298 697 int do_ssh2_transport_crstate;
698 int do_ssh2_authconn_crstate;
699
700 void *do_ssh_init_state;
701 void *do_ssh1_login_state;
702 void *do_ssh2_transport_state;
703 void *do_ssh2_authconn_state;
704
705 struct rdpkt1_state_tag rdpkt1_state;
706 struct rdpkt2_state_tag rdpkt2_state;
707
b09eaa88 708 /* ssh1 and ssh2 use this for different things, but both use it */
709 int protocol_initial_phase_done;
710
ff3187f6 711 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
712 struct Packet *pkt);
713 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 714
715 /*
716 * We maintain a full _copy_ of a Config structure here, not
717 * merely a pointer to it. That way, when we're passed a new
718 * one for reconfiguration, we can check the differences and
719 * potentially reconfigure port forwardings etc in mid-session.
720 */
721 Config cfg;
839f10db 722
723 /*
724 * Used to transfer data back from async agent callbacks.
725 */
726 void *agent_response;
727 int agent_response_len;
b09eaa88 728
729 /*
730 * Dispatch table for packet types that we may have to deal
731 * with at any time.
732 */
733 handler_fn_t packet_dispatch[256];
39934deb 734
735 /*
06fadff5 736 * Queues of one-off handler functions for success/failure
737 * indications from a request.
738 */
739 struct queued_handler *qhead, *qtail;
740
741 /*
39934deb 742 * This module deals with sending keepalives.
743 */
744 Pinger pinger;
9442dd57 745
746 /*
747 * Track incoming and outgoing data sizes and time, for
748 * size-based rekeys.
749 */
750 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 751 unsigned long max_data_size;
9442dd57 752 int kex_in_progress;
e6c1536e 753 long next_rekey, last_rekey;
e13bba36 754 char *deferred_rekey_reason; /* points to STATIC string; don't free */
51470298 755};
960e736a 756
382908ad 757#define logevent(s) logevent(ssh->frontend, s)
a8327734 758
759/* logevent, only printf-formatted. */
cbe2d68f 760static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 761{
762 va_list ap;
57356d63 763 char *buf;
a8327734 764
765 va_start(ap, fmt);
57356d63 766 buf = dupvprintf(fmt, ap);
a8327734 767 va_end(ap);
57356d63 768 logevent(buf);
57356d63 769 sfree(buf);
a8327734 770}
771
6b5cf8b4 772#define bombout(msg) \
773 do { \
774 char *text = dupprintf msg; \
36f94d1f 775 ssh_do_close(ssh); \
6b5cf8b4 776 logevent(text); \
777 connection_fatal(ssh->frontend, "%s", text); \
778 sfree(text); \
779 } while (0)
a8327734 780
9a10ecf4 781/* Functions to leave bits out of the SSH packet log file. */
782
ff3187f6 783static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 784{
785 if (ssh->cfg.logomitpass)
ff3187f6 786 pkt->logmode = blanktype;
9a10ecf4 787}
788
ff3187f6 789static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 790{
791 if (ssh->cfg.logomitdata)
ff3187f6 792 pkt->logmode = blanktype;
9a10ecf4 793}
794
ff3187f6 795static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 796{
ff3187f6 797 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 798}
799
32874aea 800static int ssh_channelcmp(void *av, void *bv)
801{
802 struct ssh_channel *a = (struct ssh_channel *) av;
803 struct ssh_channel *b = (struct ssh_channel *) bv;
804 if (a->localid < b->localid)
805 return -1;
806 if (a->localid > b->localid)
807 return +1;
dacbd0e8 808 return 0;
809}
32874aea 810static int ssh_channelfind(void *av, void *bv)
811{
812 unsigned *a = (unsigned *) av;
813 struct ssh_channel *b = (struct ssh_channel *) bv;
814 if (*a < b->localid)
815 return -1;
816 if (*a > b->localid)
817 return +1;
dacbd0e8 818 return 0;
819}
820
bc240b21 821static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 822{
823 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
824 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
825 int i;
bc240b21 826 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 827 return i < 0 ? -1 : +1;
bc240b21 828 if (a->dport > b->dport)
829 return +1;
830 if (a->dport < b->dport)
831 return -1;
832 return 0;
833}
834
835static int ssh_rportcmp_ssh2(void *av, void *bv)
836{
837 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
838 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 839
bc240b21 840 if (a->sport > b->sport)
d74d141c 841 return +1;
bc240b21 842 if (a->sport < b->sport)
843 return -1;
d74d141c 844 return 0;
845}
846
fda2feb1 847/*
848 * Special form of strcmp which can cope with NULL inputs. NULL is
849 * defined to sort before even the empty string.
850 */
851static int nullstrcmp(const char *a, const char *b)
852{
853 if (a == NULL && b == NULL)
854 return 0;
855 if (a == NULL)
856 return -1;
857 if (b == NULL)
858 return +1;
859 return strcmp(a, b);
860}
861
862static int ssh_portcmp(void *av, void *bv)
863{
864 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
865 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
866 int i;
867 if (a->type > b->type)
868 return +1;
869 if (a->type < b->type)
870 return -1;
84328ddb 871 if (a->addressfamily > b->addressfamily)
872 return +1;
873 if (a->addressfamily < b->addressfamily)
874 return -1;
fda2feb1 875 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
876 return i < 0 ? -1 : +1;
877 if (a->sport > b->sport)
878 return +1;
879 if (a->sport < b->sport)
880 return -1;
881 if (a->type != 'D') {
882 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
883 return i < 0 ? -1 : +1;
884 if (a->dport > b->dport)
885 return +1;
886 if (a->dport < b->dport)
887 return -1;
888 }
889 return 0;
890}
891
51470298 892static int alloc_channel_id(Ssh ssh)
32874aea 893{
260f3dec 894 const unsigned CHANNEL_NUMBER_OFFSET = 256;
895 unsigned low, high, mid;
d2371c81 896 int tsize;
897 struct ssh_channel *c;
898
899 /*
900 * First-fit allocation of channel numbers: always pick the
901 * lowest unused one. To do this, binary-search using the
902 * counted B-tree to find the largest channel ID which is in a
903 * contiguous sequence from the beginning. (Precisely
904 * everything in that sequence must have ID equal to its tree
905 * index plus CHANNEL_NUMBER_OFFSET.)
906 */
51470298 907 tsize = count234(ssh->channels);
d2371c81 908
32874aea 909 low = -1;
910 high = tsize;
d2371c81 911 while (high - low > 1) {
912 mid = (high + low) / 2;
51470298 913 c = index234(ssh->channels, mid);
d2371c81 914 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
915 low = mid; /* this one is fine */
916 else
917 high = mid; /* this one is past it */
918 }
919 /*
920 * Now low points to either -1, or the tree index of the
921 * largest ID in the initial sequence.
922 */
923 {
924 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 925 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 926 }
927 return low + 1 + CHANNEL_NUMBER_OFFSET;
928}
929
9fab77dc 930static void c_write(Ssh ssh, const char *buf, int len)
32874aea 931{
67779be7 932 if ((flags & FLAG_STDERR)) {
32874aea 933 int i;
934 for (i = 0; i < len; i++)
935 if (buf[i] != '\r')
936 fputc(buf[i], stderr);
fb09bf1c 937 return;
938 }
51470298 939 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 940}
941
9fab77dc 942static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 943{
a209e957 944 int i;
945 for (i = 0; i < len; i++) {
32874aea 946 if (buf[i] == '\n')
51470298 947 c_write(ssh, "\r\n", 2);
32874aea 948 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 949 c_write(ssh, buf + i, 1);
a209e957 950 }
951}
952
9fab77dc 953static void c_write_str(Ssh ssh, const char *buf)
32874aea 954{
51470298 955 c_write(ssh, buf, strlen(buf));
1408a877 956}
957
ff3187f6 958static void ssh_free_packet(struct Packet *pkt)
959{
960 sfree(pkt->data);
961 sfree(pkt);
962}
963static struct Packet *ssh_new_packet(void)
964{
965 struct Packet *pkt = snew(struct Packet);
966
967 pkt->data = NULL;
968 pkt->maxlen = 0;
969 pkt->logmode = PKTLOG_EMIT;
970 pkt->nblanks = 0;
971 pkt->blanks = NULL;
972
973 return pkt;
974}
975
fb09bf1c 976/*
977 * Collect incoming data in the incoming packet buffer.
e5574168 978 * Decipher and verify the packet when it is completely read.
979 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 980 * Update the *data and *datalen variables.
ff3187f6 981 * Return a Packet structure when a packet is completed.
fb09bf1c 982 */
ff3187f6 983static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 984{
51470298 985 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 986
51470298 987 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 988
ff3187f6 989 st->pktin = ssh_new_packet();
990
991 st->pktin->type = 0;
992 st->pktin->length = 0;
374330e2 993
57476f6b 994 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 995 while ((*datalen) == 0)
ff3187f6 996 crReturn(NULL);
57476f6b 997 st->len = (st->len << 8) + **data;
fb09bf1c 998 (*data)++, (*datalen)--;
999 }
374330e2 1000
57476f6b 1001 st->pad = 8 - (st->len % 8);
1002 st->biglen = st->len + st->pad;
ff3187f6 1003 st->pktin->length = st->len - 5;
fb09bf1c 1004
ae0500e5 1005 if (st->biglen < 0) {
1006 bombout(("Extremely large packet length from server suggests"
1007 " data stream corruption"));
ff3187f6 1008 ssh_free_packet(st->pktin);
1009 crStop(NULL);
ae0500e5 1010 }
1011
ff3187f6 1012 st->pktin->maxlen = st->biglen;
1013 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1014
57476f6b 1015 st->to_read = st->biglen;
ff3187f6 1016 st->p = st->pktin->data;
57476f6b 1017 while (st->to_read > 0) {
32874aea 1018 st->chunk = st->to_read;
fb09bf1c 1019 while ((*datalen) == 0)
ff3187f6 1020 crReturn(NULL);
57476f6b 1021 if (st->chunk > (*datalen))
1022 st->chunk = (*datalen);
1023 memcpy(st->p, *data, st->chunk);
1024 *data += st->chunk;
1025 *datalen -= st->chunk;
1026 st->p += st->chunk;
1027 st->to_read -= st->chunk;
fb09bf1c 1028 }
374330e2 1029
ff3187f6 1030 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1031 st->biglen, NULL)) {
6b5cf8b4 1032 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1033 ssh_free_packet(st->pktin);
1034 crStop(NULL);
9a3a93a5 1035 }
1036
51470298 1037 if (ssh->cipher)
ff3187f6 1038 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1039
ff3187f6 1040 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1041 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1042 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1043 bombout(("Incorrect CRC received on packet"));
ff3187f6 1044 ssh_free_packet(st->pktin);
1045 crStop(NULL);
fb09bf1c 1046 }
572f871e 1047
ff3187f6 1048 st->pktin->body = st->pktin->data + st->pad + 1;
1049 st->pktin->savedpos = 0;
4ba9b64b 1050
51470298 1051 if (ssh->v1_compressing) {
4ba9b64b 1052 unsigned char *decompblk;
1053 int decomplen;
36b8d9bb 1054 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1055 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1056 &decompblk, &decomplen)) {
1057 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1058 ssh_free_packet(st->pktin);
1059 crStop(NULL);
36b8d9bb 1060 }
4ba9b64b 1061
ff3187f6 1062 if (st->pktin->maxlen < st->pad + decomplen) {
1063 st->pktin->maxlen = st->pad + decomplen;
1064 st->pktin->data = sresize(st->pktin->data,
1065 st->pktin->maxlen + APIEXTRA,
3d88e64d 1066 unsigned char);
ff3187f6 1067 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1068 }
1069
ff3187f6 1070 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1071 sfree(decompblk);
ff3187f6 1072 st->pktin->length = decomplen - 1;
4ba9b64b 1073 }
1074
ff3187f6 1075 st->pktin->type = st->pktin->body[-1];
00db133f 1076
9a10ecf4 1077 /*
1078 * Log incoming packet, possibly omitting sensitive fields.
1079 */
1080 if (ssh->logctx) {
1081 int nblanks = 0;
1082 struct logblank_t blank;
1083 if (ssh->cfg.logomitdata) {
1084 int do_blank = FALSE, blank_prefix = 0;
1085 /* "Session data" packets - omit the data field */
ff3187f6 1086 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1087 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1088 do_blank = TRUE; blank_prefix = 0;
ff3187f6 1089 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
9a10ecf4 1090 do_blank = TRUE; blank_prefix = 4;
1091 }
1092 if (do_blank) {
1093 blank.offset = blank_prefix;
ff3187f6 1094 blank.len = st->pktin->length;
9a10ecf4 1095 blank.type = PKTLOG_OMIT;
1096 nblanks = 1;
1097 }
1098 }
a8327734 1099 log_packet(ssh->logctx,
ff3187f6 1100 PKT_INCOMING, st->pktin->type,
1101 ssh1_pkt_type(st->pktin->type),
1102 st->pktin->body, st->pktin->length,
9a10ecf4 1103 nblanks, &blank);
1104 }
00db133f 1105
ff3187f6 1106 crFinish(st->pktin);
fb09bf1c 1107}
1108
ff3187f6 1109static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1110{
51470298 1111 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1112
51470298 1113 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1114
ff3187f6 1115 st->pktin = ssh_new_packet();
1116
1117 st->pktin->type = 0;
1118 st->pktin->length = 0;
51470298 1119 if (ssh->sccipher)
1120 st->cipherblk = ssh->sccipher->blksize;
e5574168 1121 else
32874aea 1122 st->cipherblk = 8;
960e736a 1123 if (st->cipherblk < 8)
32874aea 1124 st->cipherblk = 8;
960e736a 1125
ff3187f6 1126 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1127
1128 /*
1129 * Acquire and decrypt the first block of the packet. This will
1130 * contain the length and padding details.
1131 */
32874aea 1132 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1133 while ((*datalen) == 0)
ff3187f6 1134 crReturn(NULL);
1135 st->pktin->data[st->i] = *(*data)++;
32874aea 1136 (*datalen)--;
e5574168 1137 }
4252c9cc 1138
51470298 1139 if (ssh->sccipher)
371e569c 1140 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1141 st->pktin->data, st->cipherblk);
e5574168 1142
1143 /*
1144 * Now get the length and padding figures.
1145 */
ff3187f6 1146 st->len = GET_32BIT(st->pktin->data);
1147 st->pad = st->pktin->data[4];
e5574168 1148
1149 /*
717dc483 1150 * _Completely_ silly lengths should be stomped on before they
1151 * do us any more damage.
1152 */
1153 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 1154 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1155 ssh_free_packet(st->pktin);
1156 crStop(NULL);
717dc483 1157 }
1158
1159 /*
e5574168 1160 * This enables us to deduce the payload length.
1161 */
960e736a 1162 st->payload = st->len - st->pad - 1;
e5574168 1163
ff3187f6 1164 st->pktin->length = st->payload + 5;
e5574168 1165
1166 /*
1167 * So now we can work out the total packet length.
1168 */
960e736a 1169 st->packetlen = st->len + 4;
51470298 1170 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1171
1172 /*
ff3187f6 1173 * Allocate memory for the rest of the packet.
e5574168 1174 */
ff3187f6 1175 st->pktin->maxlen = st->packetlen + st->maclen;
1176 st->pktin->data = sresize(st->pktin->data,
1177 st->pktin->maxlen + APIEXTRA,
1178 unsigned char);
e5574168 1179
1180 /*
1181 * Read and decrypt the remainder of the packet.
1182 */
32874aea 1183 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1184 st->i++) {
e5574168 1185 while ((*datalen) == 0)
ff3187f6 1186 crReturn(NULL);
1187 st->pktin->data[st->i] = *(*data)++;
32874aea 1188 (*datalen)--;
e5574168 1189 }
1190 /* Decrypt everything _except_ the MAC. */
51470298 1191 if (ssh->sccipher)
371e569c 1192 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1193 st->pktin->data + st->cipherblk,
51470298 1194 st->packetlen - st->cipherblk);
e5574168 1195
9442dd57 1196 st->pktin->encrypted_len = st->packetlen;
1197
e5574168 1198 /*
1199 * Check the MAC.
1200 */
51470298 1201 if (ssh->scmac
ff3187f6 1202 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1203 st->incoming_sequence)) {
6b5cf8b4 1204 bombout(("Incorrect MAC received on packet"));
ff3187f6 1205 ssh_free_packet(st->pktin);
1206 crStop(NULL);
8d5de777 1207 }
b09eaa88 1208
1209 st->pktin->sequence = st->incoming_sequence++;
e5574168 1210
4ba9b64b 1211 /*
1212 * Decompress packet payload.
1213 */
1214 {
1215 unsigned char *newpayload;
1216 int newlen;
51470298 1217 if (ssh->sccomp &&
5366aed8 1218 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1219 st->pktin->data + 5, st->pktin->length - 5,
51470298 1220 &newpayload, &newlen)) {
ff3187f6 1221 if (st->pktin->maxlen < newlen + 5) {
1222 st->pktin->maxlen = newlen + 5;
1223 st->pktin->data = sresize(st->pktin->data,
1224 st->pktin->maxlen + APIEXTRA,
3d88e64d 1225 unsigned char);
4ba9b64b 1226 }
ff3187f6 1227 st->pktin->length = 5 + newlen;
1228 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1229 sfree(newpayload);
4ba9b64b 1230 }
1231 }
1232
ff3187f6 1233 st->pktin->savedpos = 6;
1234 st->pktin->body = st->pktin->data;
1235 st->pktin->type = st->pktin->data[5];
e5574168 1236
9a10ecf4 1237 /*
1238 * Log incoming packet, possibly omitting sensitive fields.
1239 */
1240 if (ssh->logctx) {
1241 int nblanks = 0;
1242 struct logblank_t blank;
1243 if (ssh->cfg.logomitdata) {
1244 int do_blank = FALSE, blank_prefix = 0;
1245 /* "Session data" packets - omit the data field */
ff3187f6 1246 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1247 do_blank = TRUE; blank_prefix = 4;
ff3187f6 1248 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
9a10ecf4 1249 do_blank = TRUE; blank_prefix = 8;
1250 }
1251 if (do_blank) {
1252 blank.offset = blank_prefix;
ff3187f6 1253 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1254 blank.type = PKTLOG_OMIT;
1255 nblanks = 1;
1256 }
1257 }
ff3187f6 1258 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1259 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1260 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1261 nblanks, &blank);
1262 }
00db133f 1263
ff3187f6 1264 crFinish(st->pktin);
e5574168 1265}
1266
ff3187f6 1267static void ssh1_pktout_size(struct Packet *pkt, int len)
32874aea 1268{
374330e2 1269 int pad, biglen;
1270
1271 len += 5; /* type and CRC */
32874aea 1272 pad = 8 - (len % 8);
374330e2 1273 biglen = len + pad;
1274
ff3187f6 1275 pkt->length = len - 5;
1276 if (pkt->maxlen < biglen) {
1277 pkt->maxlen = biglen;
1278 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
374330e2 1279 }
ff3187f6 1280 pkt->body = pkt->data + 4 + pad + 1;
4ba9b64b 1281}
374330e2 1282
ff3187f6 1283static struct Packet *s_wrpkt_start(int type, int len)
32874aea 1284{
ff3187f6 1285 struct Packet *pkt = ssh_new_packet();
1286 ssh1_pktout_size(pkt, len);
1287 pkt->type = type;
9a10ecf4 1288 /* Initialise log omission state */
ff3187f6 1289 pkt->nblanks = 0;
1290 pkt->blanks = NULL;
1291 return pkt;
374330e2 1292}
1293
ff3187f6 1294static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
32874aea 1295{
fd7a4aad 1296 int pad, biglen, i;
374330e2 1297 unsigned long crc;
fd7a4aad 1298#ifdef __SC__
1299 /*
1300 * XXX various versions of SC (including 8.8.4) screw up the
1301 * register allocation in this function and use the same register
1302 * (D6) for len and as a temporary, with predictable results. The
1303 * following sledgehammer prevents this.
1304 */
1305 volatile
1306#endif
1307 int len;
374330e2 1308
ff3187f6 1309 pkt->body[-1] = pkt->type;
4ba9b64b 1310
a8327734 1311 if (ssh->logctx)
ff3187f6 1312 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1313 ssh1_pkt_type(pkt->type),
1314 pkt->body, pkt->length,
1315 pkt->nblanks, pkt->blanks);
1316 sfree(pkt->blanks); pkt->blanks = NULL;
1317 pkt->nblanks = 0;
00db133f 1318
51470298 1319 if (ssh->v1_compressing) {
4ba9b64b 1320 unsigned char *compblk;
1321 int complen;
5366aed8 1322 zlib_compress_block(ssh->cs_comp_ctx,
ff3187f6 1323 pkt->body - 1, pkt->length + 1,
4ba9b64b 1324 &compblk, &complen);
ff3187f6 1325 ssh1_pktout_size(pkt, complen - 1);
1326 memcpy(pkt->body - 1, compblk, complen);
dcbde236 1327 sfree(compblk);
4ba9b64b 1328 }
1329
ff3187f6 1330 len = pkt->length + 5; /* type and CRC */
32874aea 1331 pad = 8 - (len % 8);
374330e2 1332 biglen = len + pad;
1333
32874aea 1334 for (i = 0; i < pad; i++)
ff3187f6 1335 pkt->data[i + 4] = random_byte();
1336 crc = crc32_compute(pkt->data + 4, biglen - 4);
1337 PUT_32BIT(pkt->data + biglen, crc);
1338 PUT_32BIT(pkt->data, len);
374330e2 1339
51470298 1340 if (ssh->cipher)
ff3187f6 1341 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
374330e2 1342
32874aea 1343 return biglen + 4;
39065bed 1344}
1345
ff3187f6 1346static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1347{
5471d09a 1348 int len, backlog;
ff3187f6 1349 len = s_wrpkt_prepare(ssh, pkt);
1350 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1351 if (backlog > SSH_MAX_BACKLOG)
51470298 1352 ssh_throttle_all(ssh, 1, backlog);
39065bed 1353}
1354
ff3187f6 1355static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1356{
39065bed 1357 int len;
ff3187f6 1358 len = s_wrpkt_prepare(ssh, pkt);
51470298 1359 if (ssh->deferred_len + len > ssh->deferred_size) {
1360 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1361 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1362 ssh->deferred_size,
1363 unsigned char);
39065bed 1364 }
ff3187f6 1365 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1366 ssh->deferred_len += len;
374330e2 1367}
1368
fb09bf1c 1369/*
39065bed 1370 * Construct a packet with the specified contents.
fb09bf1c 1371 */
ff3187f6 1372static struct Packet *construct_packet(Ssh ssh, int pkttype,
1373 va_list ap1, va_list ap2)
fb09bf1c 1374{
fb09bf1c 1375 unsigned char *p, *argp, argchar;
1376 unsigned long argint;
1377 int pktlen, argtype, arglen;
7cca0d81 1378 Bignum bn;
ff3187f6 1379 struct Packet *pkt;
fb09bf1c 1380
1381 pktlen = 0;
39065bed 1382 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1383 switch (argtype) {
1384 case PKT_INT:
39065bed 1385 (void) va_arg(ap1, int);
fb09bf1c 1386 pktlen += 4;
1387 break;
1388 case PKT_CHAR:
1ec39246 1389 (void) va_arg(ap1, int);
fb09bf1c 1390 pktlen++;
1391 break;
1392 case PKT_DATA:
39065bed 1393 (void) va_arg(ap1, unsigned char *);
1394 arglen = va_arg(ap1, int);
fb09bf1c 1395 pktlen += arglen;
1396 break;
1397 case PKT_STR:
39065bed 1398 argp = va_arg(ap1, unsigned char *);
d8baa528 1399 arglen = strlen((char *)argp);
fb09bf1c 1400 pktlen += 4 + arglen;
1401 break;
7cca0d81 1402 case PKT_BIGNUM:
39065bed 1403 bn = va_arg(ap1, Bignum);
32874aea 1404 pktlen += ssh1_bignum_length(bn);
7cca0d81 1405 break;
9a10ecf4 1406 case PKTT_PASSWORD:
1407 case PKTT_DATA:
1408 case PKTT_OTHER:
1409 /* ignore this pass */
1410 break;
fb09bf1c 1411 default:
1412 assert(0);
1413 }
1414 }
fb09bf1c 1415
ff3187f6 1416 pkt = s_wrpkt_start(pkttype, pktlen);
1417 p = pkt->body;
fb09bf1c 1418
39065bed 1419 while ((argtype = va_arg(ap2, int)) != PKT_END) {
ff3187f6 1420 int offset = p - pkt->body, len = 0;
fb09bf1c 1421 switch (argtype) {
9a10ecf4 1422 /* Actual fields in the packet */
fb09bf1c 1423 case PKT_INT:
39065bed 1424 argint = va_arg(ap2, int);
fb09bf1c 1425 PUT_32BIT(p, argint);
9a10ecf4 1426 len = 4;
fb09bf1c 1427 break;
1428 case PKT_CHAR:
1ec39246 1429 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1430 *p = argchar;
9a10ecf4 1431 len = 1;
fb09bf1c 1432 break;
1433 case PKT_DATA:
39065bed 1434 argp = va_arg(ap2, unsigned char *);
1435 arglen = va_arg(ap2, int);
fb09bf1c 1436 memcpy(p, argp, arglen);
9a10ecf4 1437 len = arglen;
fb09bf1c 1438 break;
1439 case PKT_STR:
39065bed 1440 argp = va_arg(ap2, unsigned char *);
d8baa528 1441 arglen = strlen((char *)argp);
fb09bf1c 1442 PUT_32BIT(p, arglen);
1443 memcpy(p + 4, argp, arglen);
9a10ecf4 1444 len = arglen + 4;
fb09bf1c 1445 break;
7cca0d81 1446 case PKT_BIGNUM:
39065bed 1447 bn = va_arg(ap2, Bignum);
9a10ecf4 1448 len = ssh1_write_bignum(p, bn);
1449 break;
1450 /* Tokens for modifications to packet logging */
1451 case PKTT_PASSWORD:
ff3187f6 1452 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1453 break;
1454 case PKTT_DATA:
ff3187f6 1455 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1456 break;
9a10ecf4 1457 case PKTT_OTHER:
ff3187f6 1458 end_log_omission(ssh, pkt);
9a10ecf4 1459 break;
1460 }
1461 p += len;
1462 /* Deal with logfile omission, if required. */
ff3187f6 1463 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1464 pkt->nblanks++;
1465 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1466 struct logblank_t);
1467 pkt->blanks[pkt->nblanks-1].offset = offset;
1468 pkt->blanks[pkt->nblanks-1].len = len;
1469 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
fb09bf1c 1470 }
1471 }
ff3187f6 1472
1473 return pkt;
39065bed 1474}
fb09bf1c 1475
51470298 1476static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1477{
ff3187f6 1478 struct Packet *pkt;
39065bed 1479 va_list ap1, ap2;
1480 va_start(ap1, pkttype);
1481 va_start(ap2, pkttype);
ff3187f6 1482 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1483 va_end(ap2);
1484 va_end(ap1);
1485 s_wrpkt(ssh, pkt);
1486 ssh_free_packet(pkt);
fb09bf1c 1487}
1488
51470298 1489static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1490{
ff3187f6 1491 struct Packet *pkt;
39065bed 1492 va_list ap1, ap2;
1493 va_start(ap1, pkttype);
1494 va_start(ap2, pkttype);
ff3187f6 1495 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1496 va_end(ap2);
1497 va_end(ap1);
1498 s_wrpkt_defer(ssh, pkt);
1499 ssh_free_packet(pkt);
39065bed 1500}
1501
32874aea 1502static int ssh_versioncmp(char *a, char *b)
1503{
9697bfd2 1504 char *ae, *be;
1505 unsigned long av, bv;
1506
43aa02a7 1507 av = strtoul(a, &ae, 10);
1508 bv = strtoul(b, &be, 10);
32874aea 1509 if (av != bv)
1510 return (av < bv ? -1 : +1);
1511 if (*ae == '.')
1512 ae++;
1513 if (*be == '.')
1514 be++;
43aa02a7 1515 av = strtoul(ae, &ae, 10);
1516 bv = strtoul(be, &be, 10);
32874aea 1517 if (av != bv)
1518 return (av < bv ? -1 : +1);
9697bfd2 1519 return 0;
1520}
1521
e5574168 1522/*
a92dd380 1523 * Utility routines for putting an SSH-protocol `string' and
1524 * `uint32' into a SHA state.
e5574168 1525 */
1526#include <stdio.h>
32874aea 1527static void sha_string(SHA_State * s, void *str, int len)
1528{
e5574168 1529 unsigned char lenblk[4];
e5574168 1530 PUT_32BIT(lenblk, len);
e5574168 1531 SHA_Bytes(s, lenblk, 4);
e5574168 1532 SHA_Bytes(s, str, len);
1533}
1534
32874aea 1535static void sha_uint32(SHA_State * s, unsigned i)
1536{
a92dd380 1537 unsigned char intblk[4];
1538 PUT_32BIT(intblk, i);
1539 SHA_Bytes(s, intblk, 4);
1540}
1541
7cca0d81 1542/*
1543 * SSH2 packet construction functions.
1544 */
ff3187f6 1545static void ssh2_pkt_ensure(struct Packet *pkt, int length)
32874aea 1546{
ff3187f6 1547 if (pkt->maxlen < length) {
1548 pkt->maxlen = length + 256;
1549 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
7cca0d81 1550 }
783415f8 1551}
ff3187f6 1552static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1553{
ff3187f6 1554 if (pkt->logmode != PKTLOG_EMIT) {
1555 pkt->nblanks++;
1556 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1557 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1558 pkt->blanks[pkt->nblanks-1].len = len;
1559 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1560 }
1561 pkt->length += len;
1562 ssh2_pkt_ensure(pkt, pkt->length);
1563 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1564}
ff3187f6 1565static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1566{
ff3187f6 1567 ssh2_pkt_adddata(pkt, &byte, 1);
7cca0d81 1568}
ff3187f6 1569static struct Packet *ssh2_pkt_init(int pkt_type)
32874aea 1570{
ff3187f6 1571 struct Packet *pkt = ssh_new_packet();
1572 pkt->length = 5;
1573 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1574 return pkt;
7cca0d81 1575}
ff3187f6 1576static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1577{
ff3187f6 1578 ssh2_pkt_adddata(pkt, &value, 1);
7cca0d81 1579}
ff3187f6 1580static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1581{
7cca0d81 1582 unsigned char x[4];
1583 PUT_32BIT(x, value);
ff3187f6 1584 ssh2_pkt_adddata(pkt, x, 4);
7cca0d81 1585}
ff3187f6 1586static void ssh2_pkt_addstring_start(struct Packet *pkt)
32874aea 1587{
ff3187f6 1588 ssh2_pkt_adduint32(pkt, 0);
1589 pkt->savedpos = pkt->length;
7cca0d81 1590}
ff3187f6 1591static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1592{
ff3187f6 1593 ssh2_pkt_adddata(pkt, data, strlen(data));
1594 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1595}
ff3187f6 1596static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1597{
ff3187f6 1598 ssh2_pkt_adddata(pkt, data, len);
1599 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1600}
ff3187f6 1601static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
32874aea 1602{
ff3187f6 1603 ssh2_pkt_addstring_start(pkt);
1604 ssh2_pkt_addstring_str(pkt, data);
7cca0d81 1605}
d8baa528 1606static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1607{
7cca0d81 1608 unsigned char *p;
32874aea 1609 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1610 p = snewn(n + 1, unsigned char);
7cca0d81 1611 if (!p)
32874aea 1612 fatalbox("out of memory");
7cca0d81 1613 p[0] = 0;
3709bfe9 1614 for (i = 1; i <= n; i++)
32874aea 1615 p[i] = bignum_byte(b, n - i);
7cca0d81 1616 i = 0;
32874aea 1617 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1618 i++;
1619 memmove(p, p + i, n + 1 - i);
1620 *len = n + 1 - i;
7cca0d81 1621 return p;
1622}
ff3187f6 1623static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1624{
7cca0d81 1625 unsigned char *p;
1626 int len;
1627 p = ssh2_mpint_fmt(b, &len);
ff3187f6 1628 ssh2_pkt_addstring_start(pkt);
1629 ssh2_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1630 sfree(p);
7cca0d81 1631}
b185170a 1632
1633/*
1634 * Construct an SSH2 final-form packet: compress it, encrypt it,
1635 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1636 * pkt->data. Total length is returned.
b185170a 1637 */
ff3187f6 1638static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1639{
7cca0d81 1640 int cipherblk, maclen, padding, i;
7cca0d81 1641
a8327734 1642 if (ssh->logctx)
ff3187f6 1643 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1644 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1645 pkt->data + 6, pkt->length - 6,
1646 pkt->nblanks, pkt->blanks);
1647 sfree(pkt->blanks); pkt->blanks = NULL;
1648 pkt->nblanks = 0;
00db133f 1649
7cca0d81 1650 /*
4ba9b64b 1651 * Compress packet payload.
1652 */
4ba9b64b 1653 {
1654 unsigned char *newpayload;
1655 int newlen;
51470298 1656 if (ssh->cscomp &&
ff3187f6 1657 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1658 pkt->length - 5,
51470298 1659 &newpayload, &newlen)) {
ff3187f6 1660 pkt->length = 5;
1661 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1662 sfree(newpayload);
4ba9b64b 1663 }
1664 }
1665
1666 /*
7cca0d81 1667 * Add padding. At least four bytes, and must also bring total
1668 * length (minus MAC) up to a multiple of the block size.
1669 */
51470298 1670 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1671 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1672 padding = 4;
32874aea 1673 padding +=
ff3187f6 1674 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
51470298 1675 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1676 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1677 pkt->data[4] = padding;
7cca0d81 1678 for (i = 0; i < padding; i++)
ff3187f6 1679 pkt->data[pkt->length + i] = random_byte();
1680 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1681 if (ssh->csmac)
ff3187f6 1682 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1683 pkt->length + padding,
51470298 1684 ssh->v2_outgoing_sequence);
1685 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1686
1687 if (ssh->cscipher)
371e569c 1688 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1689 pkt->data, pkt->length + padding);
51470298 1690
9442dd57 1691 pkt->encrypted_len = pkt->length + padding;
1692
ff3187f6 1693 /* Ready-to-send packet starts at pkt->data. We return length. */
1694 return pkt->length + padding + maclen;
b185170a 1695}
1696
1697/*
590f6a5f 1698 * Routines called from the main SSH code to send packets. There
1699 * are quite a few of these, because we have two separate
1700 * mechanisms for delaying the sending of packets:
1701 *
1702 * - In order to send an IGNORE message and a password message in
1703 * a single fixed-length blob, we require the ability to
1704 * concatenate the encrypted forms of those two packets _into_ a
1705 * single blob and then pass it to our <network.h> transport
1706 * layer in one go. Hence, there's a deferment mechanism which
1707 * works after packet encryption.
1708 *
1709 * - In order to avoid sending any connection-layer messages
1710 * during repeat key exchange, we have to queue up any such
1711 * outgoing messages _before_ they are encrypted (and in
1712 * particular before they're allocated sequence numbers), and
1713 * then send them once we've finished.
1714 *
1715 * I call these mechanisms `defer' and `queue' respectively, so as
1716 * to distinguish them reasonably easily.
1717 *
1718 * The functions send_noqueue() and defer_noqueue() free the packet
1719 * structure they are passed. Every outgoing packet goes through
1720 * precisely one of these functions in its life; packets passed to
1721 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1722 * these or get queued, and then when the queue is later emptied
1723 * the packets are all passed to defer_noqueue().
b185170a 1724 */
590f6a5f 1725
1726/*
1727 * Send an SSH2 packet immediately, without queuing or deferring.
1728 */
1729static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1730{
5471d09a 1731 int len;
1732 int backlog;
ff3187f6 1733 len = ssh2_pkt_construct(ssh, pkt);
1734 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1735 if (backlog > SSH_MAX_BACKLOG)
51470298 1736 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1737
1738 ssh->outgoing_data_size += pkt->encrypted_len;
1739 if (!ssh->kex_in_progress &&
d57f70af 1740 ssh->max_data_size != 0 &&
1741 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1742 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1743
ff3187f6 1744 ssh_free_packet(pkt);
b185170a 1745}
1746
1747/*
590f6a5f 1748 * Defer an SSH2 packet.
b185170a 1749 */
590f6a5f 1750static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1751{
ff3187f6 1752 int len = ssh2_pkt_construct(ssh, pkt);
51470298 1753 if (ssh->deferred_len + len > ssh->deferred_size) {
1754 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1755 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1756 ssh->deferred_size,
1757 unsigned char);
b185170a 1758 }
ff3187f6 1759 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1760 ssh->deferred_len += len;
9442dd57 1761 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1762 ssh_free_packet(pkt);
b185170a 1763}
1764
1765/*
590f6a5f 1766 * Queue an SSH2 packet.
1767 */
1768static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1769{
1770 assert(ssh->queueing);
1771
1772 if (ssh->queuelen >= ssh->queuesize) {
1773 ssh->queuesize = ssh->queuelen + 32;
1774 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1775 }
1776
1777 ssh->queue[ssh->queuelen++] = pkt;
1778}
1779
1780/*
1781 * Either queue or send a packet, depending on whether queueing is
1782 * set.
1783 */
1784static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1785{
1786 if (ssh->queueing)
1787 ssh2_pkt_queue(ssh, pkt);
1788 else
1789 ssh2_pkt_send_noqueue(ssh, pkt);
1790}
1791
1792/*
1793 * Either queue or defer a packet, depending on whether queueing is
1794 * set.
1795 */
1796static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1797{
1798 if (ssh->queueing)
1799 ssh2_pkt_queue(ssh, pkt);
1800 else
1801 ssh2_pkt_defer_noqueue(ssh, pkt);
1802}
1803
1804/*
b185170a 1805 * Send the whole deferred data block constructed by
39065bed 1806 * ssh2_pkt_defer() or SSH1's defer_packet().
590f6a5f 1807 *
1808 * The expected use of the defer mechanism is that you call
1809 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1810 * not currently queueing, this simply sets up deferred_send_data
1811 * and then sends it. If we _are_ currently queueing, the calls to
1812 * ssh2_pkt_defer() put the deferred packets on to the queue
1813 * instead, and therefore ssh_pkt_defersend() has no deferred data
1814 * to send. Hence, there's no need to make it conditional on
1815 * ssh->queueing.
b185170a 1816 */
51470298 1817static void ssh_pkt_defersend(Ssh ssh)
32874aea 1818{
5471d09a 1819 int backlog;
d8baa528 1820 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1821 ssh->deferred_len);
51470298 1822 ssh->deferred_len = ssh->deferred_size = 0;
1823 sfree(ssh->deferred_send_data);
1824 ssh->deferred_send_data = NULL;
5471d09a 1825 if (backlog > SSH_MAX_BACKLOG)
51470298 1826 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1827
1828 ssh->outgoing_data_size += ssh->deferred_data_size;
1829 if (!ssh->kex_in_progress &&
d57f70af 1830 ssh->max_data_size != 0 &&
1831 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1832 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1833 ssh->deferred_data_size = 0;
7cca0d81 1834}
1835
590f6a5f 1836/*
1837 * Send all queued SSH2 packets. We send them by means of
1838 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1839 * packets that needed to be lumped together.
1840 */
1841static void ssh2_pkt_queuesend(Ssh ssh)
1842{
1843 int i;
1844
1845 assert(!ssh->queueing);
1846
1847 for (i = 0; i < ssh->queuelen; i++)
1848 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1849 ssh->queuelen = 0;
1850
1851 ssh_pkt_defersend(ssh);
1852}
1853
7cca0d81 1854#if 0
32874aea 1855void bndebug(char *string, Bignum b)
1856{
7cca0d81 1857 unsigned char *p;
1858 int i, len;
1859 p = ssh2_mpint_fmt(b, &len);
1860 debug(("%s", string));
1861 for (i = 0; i < len; i++)
32874aea 1862 debug((" %02x", p[i]));
765c4200 1863 debug(("\n"));
dcbde236 1864 sfree(p);
7cca0d81 1865}
1866#endif
1867
32874aea 1868static void sha_mpint(SHA_State * s, Bignum b)
1869{
7cca0d81 1870 unsigned char *p;
1871 int len;
1872 p = ssh2_mpint_fmt(b, &len);
1873 sha_string(s, p, len);
dcbde236 1874 sfree(p);
7cca0d81 1875}
1876
1877/*
0016d70b 1878 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1879 */
ff3187f6 1880static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1881{
7cca0d81 1882 unsigned long value;
ff3187f6 1883 if (pkt->length - pkt->savedpos < 4)
32874aea 1884 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1885 value = GET_32BIT(pkt->body + pkt->savedpos);
1886 pkt->savedpos += 4;
7cca0d81 1887 return value;
1888}
ff3187f6 1889static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1890{
65a22376 1891 unsigned long value;
ff3187f6 1892 if (pkt->length - pkt->savedpos < 1)
32874aea 1893 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1894 value = pkt->body[pkt->savedpos] != 0;
1895 pkt->savedpos++;
65a22376 1896 return value;
1897}
ff3187f6 1898static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 1899{
57356d63 1900 int len;
7cca0d81 1901 *p = NULL;
45068b27 1902 *length = 0;
ff3187f6 1903 if (pkt->length - pkt->savedpos < 4)
32874aea 1904 return;
ff3187f6 1905 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 1906 if (len < 0)
1907 return;
1908 *length = len;
ff3187f6 1909 pkt->savedpos += 4;
1910 if (pkt->length - pkt->savedpos < *length)
32874aea 1911 return;
ff3187f6 1912 *p = (char *)(pkt->body + pkt->savedpos);
1913 pkt->savedpos += *length;
7cca0d81 1914}
ff3187f6 1915static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 1916{
ff3187f6 1917 if (pkt->length - pkt->savedpos < length)
0016d70b 1918 return NULL;
ff3187f6 1919 pkt->savedpos += length;
1920 return pkt->body + (pkt->savedpos - length);
0016d70b 1921}
ff3187f6 1922static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 1923 unsigned char **keystr)
1924{
1925 int j;
1926
ff3187f6 1927 j = makekey(pkt->body + pkt->savedpos,
1928 pkt->length - pkt->savedpos,
0016d70b 1929 key, keystr, 0);
1930
1931 if (j < 0)
1932 return FALSE;
1933
ff3187f6 1934 pkt->savedpos += j;
1935 assert(pkt->savedpos < pkt->length);
0016d70b 1936
1937 return TRUE;
1938}
ff3187f6 1939static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 1940{
1941 int j;
1942 Bignum b;
1943
ff3187f6 1944 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1945 pkt->length - pkt->savedpos, &b);
0016d70b 1946
1947 if (j < 0)
1948 return NULL;
1949
ff3187f6 1950 pkt->savedpos += j;
0016d70b 1951 return b;
1952}
ff3187f6 1953static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 1954{
7cca0d81 1955 char *p;
3709bfe9 1956 int length;
7cca0d81 1957 Bignum b;
1958
ff3187f6 1959 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 1960 if (!p)
32874aea 1961 return NULL;
ff3187f6 1962 if (p[0] & 0x80)
32874aea 1963 return NULL;
d8baa528 1964 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1965 return b;
1966}
1967
7d503c31 1968/*
1dd353b5 1969 * Helper function to add an SSH2 signature blob to a packet.
1970 * Expects to be shown the public key blob as well as the signature
1971 * blob. Normally works just like ssh2_pkt_addstring, but will
1972 * fiddle with the signature packet if necessary for
1973 * BUG_SSH2_RSA_PADDING.
1974 */
ff3187f6 1975static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1976 void *pkblob_v, int pkblob_len,
1dd353b5 1977 void *sigblob_v, int sigblob_len)
1978{
1979 unsigned char *pkblob = (unsigned char *)pkblob_v;
1980 unsigned char *sigblob = (unsigned char *)sigblob_v;
1981
1982 /* dmemdump(pkblob, pkblob_len); */
1983 /* dmemdump(sigblob, sigblob_len); */
1984
1985 /*
1986 * See if this is in fact an ssh-rsa signature and a buggy
1987 * server; otherwise we can just do this the easy way.
1988 */
51470298 1989 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1990 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1991 int pos, len, siglen;
1992
1993 /*
1994 * Find the byte length of the modulus.
1995 */
1996
1997 pos = 4+7; /* skip over "ssh-rsa" */
1998 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1999 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2000 pos += 4; /* find modulus itself */
2001 while (len > 0 && pkblob[pos] == 0)
2002 len--, pos++;
2003 /* debug(("modulus length is %d\n", len)); */
2004
2005 /*
2006 * Now find the signature integer.
2007 */
2008 pos = 4+7; /* skip over "ssh-rsa" */
2009 siglen = GET_32BIT(sigblob+pos);
2010 /* debug(("signature length is %d\n", siglen)); */
2011
2012 if (len != siglen) {
2013 unsigned char newlen[4];
ff3187f6 2014 ssh2_pkt_addstring_start(pkt);
2015 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2016 /* dmemdump(sigblob, pos); */
2017 pos += 4; /* point to start of actual sig */
2018 PUT_32BIT(newlen, len);
ff3187f6 2019 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2020 /* dmemdump(newlen, 4); */
2021 newlen[0] = 0;
2022 while (len-- > siglen) {
ff3187f6 2023 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2024 /* dmemdump(newlen, 1); */
2025 }
ff3187f6 2026 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2027 /* dmemdump(sigblob+pos, siglen); */
2028 return;
2029 }
2030
2031 /* Otherwise fall through and do it the easy way. */
2032 }
2033
ff3187f6 2034 ssh2_pkt_addstring_start(pkt);
2035 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2036}
2037
2038/*
7d503c31 2039 * Examine the remote side's version string and compare it against
2040 * a list of known buggy implementations.
2041 */
51470298 2042static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2043{
2044 char *imp; /* pointer to implementation part */
7d503c31 2045 imp = vstring;
2046 imp += strcspn(imp, "-");
bd358db1 2047 if (*imp) imp++;
7d503c31 2048 imp += strcspn(imp, "-");
bd358db1 2049 if (*imp) imp++;
7d503c31 2050
51470298 2051 ssh->remote_bugs = 0;
7d503c31 2052
5ecd7ad0 2053 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2054 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 2055 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2056 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2057 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2058 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2059 /*
2060 * These versions don't support SSH1_MSG_IGNORE, so we have
2061 * to use a different defence against password length
2062 * sniffing.
2063 */
51470298 2064 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 2065 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 2066 }
2067
5ecd7ad0 2068 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2069 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 2070 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2071 /*
2072 * These versions need a plain password sent; they can't
2073 * handle having a null and a random length of data after
2074 * the password.
2075 */
51470298 2076 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 2077 logevent("We believe remote version needs a plain SSH1 password");
2078 }
2079
5ecd7ad0 2080 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2081 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2082 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2083 /*
2084 * These versions apparently have no clue whatever about
2085 * RSA authentication and will panic and die if they see
2086 * an AUTH_RSA message.
2087 */
51470298 2088 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 2089 logevent("We believe remote version can't handle RSA authentication");
2090 }
2091
5ecd7ad0 2092 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2093 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2094 !wc_match("* VShell", imp) &&
831301f6 2095 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2096 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2097 wc_match("2.1 *", imp)))) {
32874aea 2098 /*
2099 * These versions have the HMAC bug.
2100 */
51470298 2101 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2102 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2103 }
1dd353b5 2104
5ecd7ad0 2105 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2106 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2107 !wc_match("* VShell", imp) &&
2856a1b9 2108 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2109 /*
2110 * These versions have the key-derivation bug (failing to
2111 * include the literal shared secret in the hashes that
2112 * generate the keys).
2113 */
51470298 2114 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2115 logevent("We believe remote version has SSH2 key-derivation bug");
2116 }
2117
5ecd7ad0 2118 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2119 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2120 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2121 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2122 /*
2123 * These versions have the SSH2 RSA padding bug.
2124 */
51470298 2125 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2126 logevent("We believe remote version has SSH2 RSA padding bug");
2127 }
8e975795 2128
dda87a28 2129 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2130 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2131 wc_match("OpenSSH_2.[0-2]*", imp))) {
2132 /*
2133 * These versions have the SSH2 session-ID bug in
2134 * public-key authentication.
2135 */
2136 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2137 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2138 }
f382c87d 2139
2140 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2141 (ssh->cfg.sshbug_rekey2 == AUTO &&
e12d95a5 2142 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2143 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2144 wc_match("Sun_SSH_1.0", imp) ||
7cb41bb2 2145 wc_match("Sun_SSH_1.0.1", imp)))) {
f382c87d 2146 /*
e12d95a5 2147 * These versions have the SSH2 rekey bug.
f382c87d 2148 */
2149 ssh->remote_bugs |= BUG_SSH2_REKEY;
e12d95a5 2150 logevent("We believe remote version has SSH2 rekey bug");
f382c87d 2151 }
7d503c31 2152}
2153
d38d6a1f 2154/*
2155 * The `software version' part of an SSH version string is required
2156 * to contain no spaces or minus signs.
2157 */
2158static void ssh_fix_verstring(char *str)
2159{
2160 /* Eat "SSH-<protoversion>-". */
2161 assert(*str == 'S'); str++;
2162 assert(*str == 'S'); str++;
2163 assert(*str == 'H'); str++;
2164 assert(*str == '-'); str++;
2165 while (*str && *str != '-') str++;
2166 assert(*str == '-'); str++;
2167
2168 /* Convert minus signs and spaces in the remaining string into
2169 * underscores. */
2170 while (*str) {
2171 if (*str == '-' || *str == ' ')
2172 *str = '_';
2173 str++;
2174 }
2175}
2176
51470298 2177static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2178{
51470298 2179 struct do_ssh_init_state {
2180 int vslen;
2181 char version[10];
2182 char *vstring;
2183 int vstrsize;
2184 int i;
2185 int proto1, proto2;
2186 };
2187 crState(do_ssh_init_state);
374330e2 2188
51470298 2189 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2190
2191 /* Search for the string "SSH-" in the input. */
51470298 2192 s->i = 0;
8df7a775 2193 while (1) {
2194 static const int transS[] = { 1, 2, 2, 1 };
2195 static const int transH[] = { 0, 0, 3, 0 };
2196 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2197 if (c == 'S')
51470298 2198 s->i = transS[s->i];
32874aea 2199 else if (c == 'H')
51470298 2200 s->i = transH[s->i];
32874aea 2201 else if (c == '-')
51470298 2202 s->i = transminus[s->i];
32874aea 2203 else
51470298 2204 s->i = 0;
2205 if (s->i < 0)
8df7a775 2206 break;
2207 crReturn(1); /* get another character */
374330e2 2208 }
8df7a775 2209
51470298 2210 s->vstrsize = 16;
3d88e64d 2211 s->vstring = snewn(s->vstrsize, char);
51470298 2212 strcpy(s->vstring, "SSH-");
2213 s->vslen = 4;
2214 s->i = 0;
374330e2 2215 while (1) {
8df7a775 2216 crReturn(1); /* get another char */
51470298 2217 if (s->vslen >= s->vstrsize - 1) {
2218 s->vstrsize += 16;
3d88e64d 2219 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2220 }
51470298 2221 s->vstring[s->vslen++] = c;
2222 if (s->i >= 0) {
374330e2 2223 if (c == '-') {
51470298 2224 s->version[s->i] = '\0';
2225 s->i = -1;
2226 } else if (s->i < sizeof(s->version) - 1)
2227 s->version[s->i++] = c;
c4ffc4d0 2228 } else if (c == '\012')
374330e2 2229 break;
2230 }
2231
51470298 2232 ssh->agentfwd_enabled = FALSE;
2233 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2234
51470298 2235 s->vstring[s->vslen] = 0;
a7d4653a 2236 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
51470298 2237 {
2238 char *vlog;
3d88e64d 2239 vlog = snewn(20 + s->vslen, char);
51470298 2240 sprintf(vlog, "Server version: %s", s->vstring);
2241 logevent(vlog);
2242 sfree(vlog);
2243 }
2244 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2245
adf799dd 2246 /*
38d228a2 2247 * Decide which SSH protocol version to support.
adf799dd 2248 */
38d228a2 2249
2250 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2251 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2252 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2253 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2254
86916870 2255 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2256 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2257 crStop(0);
38d228a2 2258 }
86916870 2259 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2260 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2261 crStop(0);
38d228a2 2262 }
2263
d38d6a1f 2264 {
2265 char *verstring;
2266
2267 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2268 /*
2269 * Construct a v2 version string.
2270 */
a7d4653a 2271 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
d38d6a1f 2272 ssh->version = 2;
2273 } else {
2274 /*
2275 * Construct a v1 version string.
2276 */
a7d4653a 2277 verstring = dupprintf("SSH-%s-%s\012",
d38d6a1f 2278 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2279 s->version : "1.5"),
2280 sshver);
2281 ssh->version = 1;
2282 }
2283
2284 ssh_fix_verstring(verstring);
2285
2286 if (ssh->version == 2) {
2287 /*
2288 * Hash our version string and their version string.
2289 */
2290 SHA_Init(&ssh->exhashbase);
0b351b6b 2291 sha_string(&ssh->exhashbase, verstring,
a7d4653a 2292 strcspn(verstring, "\015\012"));
0b351b6b 2293 sha_string(&ssh->exhashbase, s->vstring,
a7d4653a 2294 strcspn(s->vstring, "\015\012"));
d38d6a1f 2295
2296 /*
2297 * Initialise SSHv2 protocol.
2298 */
2299 ssh->protocol = ssh2_protocol;
2300 ssh2_protocol_setup(ssh);
2301 ssh->s_rdpkt = ssh2_rdpkt;
2302 } else {
2303 /*
2304 * Initialise SSHv1 protocol.
2305 */
2306 ssh->protocol = ssh1_protocol;
2307 ssh1_protocol_setup(ssh);
2308 ssh->s_rdpkt = ssh1_rdpkt;
2309 }
2310 logeventf(ssh, "We claim version: %.*s",
a7d4653a 2311 strcspn(verstring, "\015\012"), verstring);
51470298 2312 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2313 sfree(verstring);
e5574168 2314 }
d38d6a1f 2315
2316 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2317
125105d1 2318 update_specials_menu(ssh->frontend);
51470298 2319 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2320 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2321
51470298 2322 sfree(s->vstring);
50526e47 2323
8df7a775 2324 crFinish(0);
2325}
2326
51470298 2327static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2328{
51470298 2329 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2330
2331 /*
2332 * To begin with, feed the characters one by one to the
2333 * protocol initialisation / selection function do_ssh_init().
2334 * When that returns 0, we're done with the initial greeting
2335 * exchange and can move on to packet discipline.
2336 */
2337 while (1) {
51470298 2338 int ret; /* need not be kept across crReturn */
8df7a775 2339 if (datalen == 0)
2340 crReturnV; /* more data please */
51470298 2341 ret = do_ssh_init(ssh, *data);
32874aea 2342 data++;
2343 datalen--;
8df7a775 2344 if (ret == 0)
2345 break;
2346 }
2347
2348 /*
2349 * We emerge from that loop when the initial negotiation is
2350 * over and we have selected an s_rdpkt function. Now pass
2351 * everything to s_rdpkt, and then pass the resulting packets
2352 * to the proper protocol handler.
2353 */
2354 if (datalen == 0)
2355 crReturnV;
2356 while (1) {
2357 while (datalen > 0) {
ff3187f6 2358 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2359 if (pktin) {
2360 ssh->protocol(ssh, NULL, 0, pktin);
2361 ssh_free_packet(pktin);
8df7a775 2362 }
ff3187f6 2363 if (ssh->state == SSH_STATE_CLOSED)
2364 return;
8df7a775 2365 }
2366 crReturnV;
2367 }
2368 crFinishV;
2369}
2370
36f94d1f 2371static void ssh_do_close(Ssh ssh)
32874aea 2372{
36f94d1f 2373 int i;
2374 struct ssh_channel *c;
2375
51470298 2376 ssh->state = SSH_STATE_CLOSED;
2377 if (ssh->s) {
2378 sk_close(ssh->s);
2379 ssh->s = NULL;
39934deb 2380 notify_remote_exit(ssh->frontend);
f3ab576e 2381 }
36f94d1f 2382 /*
2383 * Now we must shut down any port and X forwardings going
2384 * through this connection.
2385 */
74a98066 2386 if (ssh->channels) {
2387 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2388 switch (c->type) {
2389 case CHAN_X11:
2390 x11_close(c->u.x11.s);
2391 break;
2392 case CHAN_SOCKDATA:
2393 pfd_close(c->u.pfd.s);
2394 break;
2395 }
2396 del234(ssh->channels, c);
2397 if (ssh->version == 2)
2398 bufchain_clear(&c->v.v2.outbuffer);
2399 sfree(c);
36f94d1f 2400 }
36f94d1f 2401 }
2402}
2403
cbe2d68f 2404static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2405 int calling_back)
2406{
2407 Ssh ssh = (Ssh) plug;
2408 ssh_do_close(ssh);
7e78000d 2409 if (error_msg) {
32874aea 2410 /* A socket error has occurred. */
247308b5 2411 logevent(error_msg);
971bcc0a 2412 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2413 } else {
2414 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2415 }
7e78000d 2416 return 0;
2417}
2418
32874aea 2419static int ssh_receive(Plug plug, int urgent, char *data, int len)
2420{
51470298 2421 Ssh ssh = (Ssh) plug;
d8baa528 2422 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2423 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2424 ssh_do_close(ssh);
32874aea 2425 return 0;
3257deae 2426 }
fef97f43 2427 return 1;
374330e2 2428}
2429
5471d09a 2430static void ssh_sent(Plug plug, int bufsize)
2431{
51470298 2432 Ssh ssh = (Ssh) plug;
5471d09a 2433 /*
2434 * If the send backlog on the SSH socket itself clears, we
2435 * should unthrottle the whole world if it was throttled.
2436 */
2437 if (bufsize < SSH_MAX_BACKLOG)
51470298 2438 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2439}
2440
fb09bf1c 2441/*
8df7a775 2442 * Connect to specified host and port.
2443 * Returns an error message, or NULL on success.
6e1ebb76 2444 * Also places the canonical host name into `realhost'. It must be
2445 * freed by the caller.
8df7a775 2446 */
cbe2d68f 2447static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2448 char **realhost, int nodelay, int keepalive)
8df7a775 2449{
51470298 2450 static const struct plug_function_table fn_table = {
7e78000d 2451 ssh_closing,
5471d09a 2452 ssh_receive,
2453 ssh_sent,
2454 NULL
51470298 2455 };
7e78000d 2456
8df7a775 2457 SockAddr addr;
cbe2d68f 2458 const char *err;
8df7a775 2459
3d88e64d 2460 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2461 if (!ssh->savedhost)
8df7a775 2462 fatalbox("Out of memory");
51470298 2463 strcpy(ssh->savedhost, host);
8df7a775 2464
2465 if (port < 0)
2466 port = 22; /* default ssh port */
51470298 2467 ssh->savedport = port;
8df7a775 2468
2469 /*
2470 * Try to find host.
2471 */
05581745 2472 logeventf(ssh, "Looking up host \"%s\"%s", host,
2473 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2474 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2475 addr = name_lookup(host, port, realhost, &ssh->cfg,
2476 ssh->cfg.addressfamily);
170c1e6e 2477 if ((err = sk_addr_error(addr)) != NULL) {
2478 sk_addr_free(addr);
8df7a775 2479 return err;
170c1e6e 2480 }
8df7a775 2481
8df7a775 2482 /*
2483 * Open socket.
2484 */
3ad9d396 2485 {
57356d63 2486 char addrbuf[100];
3ad9d396 2487 sk_getaddr(addr, addrbuf, 100);
57356d63 2488 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2489 }
51470298 2490 ssh->fn = &fn_table;
e8fa8f62 2491 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2492 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2493 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2494 ssh->s = NULL;
39934deb 2495 notify_remote_exit(ssh->frontend);
8df7a775 2496 return err;
67c4ba2e 2497 }
8df7a775 2498
8df7a775 2499 return NULL;
2500}
2501
2502/*
5471d09a 2503 * Throttle or unthrottle the SSH connection.
2504 */
51470298 2505static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2506{
51470298 2507 int old_count = ssh->v1_throttle_count;
2508 ssh->v1_throttle_count += adjust;
2509 assert(ssh->v1_throttle_count >= 0);
2510 if (ssh->v1_throttle_count && !old_count) {
2511 sk_set_frozen(ssh->s, 1);
2512 } else if (!ssh->v1_throttle_count && old_count) {
2513 sk_set_frozen(ssh->s, 0);
5471d09a 2514 }
2515}
2516
2517/*
2518 * Throttle or unthrottle _all_ local data streams (for when sends
2519 * on the SSH connection itself back up).
2520 */
51470298 2521static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2522{
2523 int i;
2524 struct ssh_channel *c;
2525
51470298 2526 if (enable == ssh->throttled_all)
5471d09a 2527 return;
51470298 2528 ssh->throttled_all = enable;
2529 ssh->overall_bufsize = bufsize;
2530 if (!ssh->channels)
5471d09a 2531 return;
51470298 2532 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2533 switch (c->type) {
2534 case CHAN_MAINSESSION:
2535 /*
2536 * This is treated separately, outside the switch.
2537 */
2538 break;
2539 case CHAN_X11:
2540 x11_override_throttle(c->u.x11.s, enable);
2541 break;
2542 case CHAN_AGENT:
2543 /* Agent channels require no buffer management. */
2544 break;
2545 case CHAN_SOCKDATA:
36f94d1f 2546 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2547 break;
2548 }
2549 }
2550}
2551
2552/*
51470298 2553 * Username and password input, abstracted off into routines
2554 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2555 */
0405e71f 2556
2557/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2558static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2559{
51470298 2560 ssh->userpass_input_buffer = buffer;
2561 ssh->userpass_input_buflen = buflen;
2562 ssh->userpass_input_bufpos = 0;
2563 ssh->userpass_input_echo = echo;
0405e71f 2564}
2565
2566/*
2567 * Process some terminal data in the course of username/password
2568 * input. Returns >0 for success (line of input returned in
2569 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2570 * for inconclusive (keep waiting for more input please).
2571 */
ae9ae89f 2572static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2573{
2574 char c;
2575
2576 while (inlen--) {
2577 switch (c = *in++) {
2578 case 10:
2579 case 13:
51470298 2580 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2581 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2582 return +1;
2583 break;
2584 case 8:
2585 case 127:
51470298 2586 if (ssh->userpass_input_bufpos > 0) {
2587 if (ssh->userpass_input_echo)
2588 c_write_str(ssh, "\b \b");
2589 ssh->userpass_input_bufpos--;
0405e71f 2590 }
2591 break;
2592 case 21:
2593 case 27:
51470298 2594 while (ssh->userpass_input_bufpos > 0) {
2595 if (ssh->userpass_input_echo)
2596 c_write_str(ssh, "\b \b");
2597 ssh->userpass_input_bufpos--;
0405e71f 2598 }
2599 break;
2600 case 3:
2601 case 4:
2602 return -1;
2603 break;
2604 default:
4692a14a 2605 /*
2606 * This simplistic check for printability is disabled
2607 * when we're doing password input, because some people
2608 * have control characters in their passwords.o
2609 */
2610 if ((!ssh->userpass_input_echo ||
2611 (c >= ' ' && c <= '~') ||
0405e71f 2612 ((unsigned char) c >= 160))
51470298 2613 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2614 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2615 if (ssh->userpass_input_echo)
2616 c_write(ssh, &c, 1);
0405e71f 2617 }
2618 break;
2619 }
2620 }
2621 return 0;
2622}
2623
f11d78f2 2624static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2625{
2626 Ssh ssh = (Ssh) sshv;
2627
2628 ssh->agent_response = reply;
2629 ssh->agent_response_len = replylen;
2630
2631 if (ssh->version == 1)
ff3187f6 2632 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2633 else
ff3187f6 2634 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2635}
2636
f11d78f2 2637static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2638{
2639 struct ssh_channel *c = (struct ssh_channel *)cv;
2640 Ssh ssh = c->ssh;
2641 void *sentreply = reply;
2642
2643 if (!sentreply) {
2644 /* Fake SSH_AGENT_FAILURE. */
2645 sentreply = "\0\0\0\1\5";
2646 replylen = 5;
2647 }
2648 if (ssh->version == 2) {
2649 ssh2_add_channel_data(c, sentreply, replylen);
2650 ssh2_try_send(c);
2651 } else {
2652 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2653 PKT_INT, c->remoteid,
9a10ecf4 2654 PKTT_DATA,
839f10db 2655 PKT_INT, replylen,
2656 PKT_DATA, sentreply, replylen,
9a10ecf4 2657 PKTT_OTHER,
839f10db 2658 PKT_END);
2659 }
2660 if (reply)
2661 sfree(reply);
2662}
2663
0405e71f 2664/*
fb09bf1c 2665 * Handle the key exchange and user authentication phases.
2666 */
ff3187f6 2667static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2668 struct Packet *pktin)
fb09bf1c 2669{
0016d70b 2670 int i, j, ret;
2671 unsigned char cookie[8], *ptr;
374330e2 2672 struct RSAKey servkey, hostkey;
2673 struct MD5Context md5c;
51470298 2674 struct do_ssh1_login_state {
2675 int len;
2676 unsigned char *rsabuf, *keystr1, *keystr2;
2677 unsigned long supported_ciphers_mask, supported_auths_mask;
2678 int tried_publickey, tried_agent;
2679 int tis_auth_refused, ccard_auth_refused;
2680 unsigned char session_id[16];
2681 int cipher_type;
2682 char username[100];
2683 void *publickey_blob;
2684 int publickey_bloblen;
2685 char password[100];
2686 char prompt[200];
2687 int pos;
2688 char c;
2689 int pwpkt_type;
2690 unsigned char request[5], *response, *p;
2691 int responselen;
2692 int keyi, nkeys;
2693 int authed;
2694 struct RSAKey key;
2695 Bignum challenge;
2696 char *commentp;
2697 int commentlen;
2698 };
2699 crState(do_ssh1_login_state);
2700
2701 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2702
ff3187f6 2703 if (!pktin)
2704 crWaitUntil(pktin);
374330e2 2705
ff3187f6 2706 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2707 bombout(("Public key packet not received"));
7ffdbc1a 2708 crStop(0);
8d5de777 2709 }
374330e2 2710
c5e9c988 2711 logevent("Received public keys");
374330e2 2712
ff3187f6 2713 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2714 if (!ptr) {
2715 bombout(("SSH1 public key packet stopped before random cookie"));
2716 crStop(0);
2717 }
2718 memcpy(cookie, ptr, 8);
374330e2 2719
ff3187f6 2720 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2721 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2722 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2723 crStop(0);
2724 }
374330e2 2725
c5e9c988 2726 /*
1c2a93c4 2727 * Log the host key fingerprint.
c5e9c988 2728 */
c5e9c988 2729 {
2730 char logmsg[80];
1c2a93c4 2731 logevent("Host key fingerprint is:");
c5e9c988 2732 strcpy(logmsg, " ");
32874aea 2733 hostkey.comment = NULL;
2734 rsa_fingerprint(logmsg + strlen(logmsg),
2735 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2736 logevent(logmsg);
2737 }
2738
ff3187f6 2739 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2740 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2741 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2742
51470298 2743 ssh->v1_local_protoflags =
2744 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2745 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2746
c5e9c988 2747 MD5Init(&md5c);
51470298 2748 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2749 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2750 MD5Update(&md5c, cookie, 8);
51470298 2751 MD5Final(s->session_id, &md5c);
374330e2 2752
32874aea 2753 for (i = 0; i < 32; i++)
51470298 2754 ssh->session_key[i] = random_byte();
374330e2 2755
0016d70b 2756 /*
2757 * Verify that the `bits' and `bytes' parameters match.
2758 */
2759 if (hostkey.bits > hostkey.bytes * 8 ||
2760 servkey.bits > servkey.bytes * 8) {
2761 bombout(("SSH1 public keys were badly formatted"));
2762 crStop(0);
2763 }
2764
51470298 2765 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2766
3d88e64d 2767 s->rsabuf = snewn(s->len, unsigned char);
51470298 2768 if (!s->rsabuf)
374330e2 2769 fatalbox("Out of memory");
2770
89ee5268 2771 /*
2772 * Verify the host key.
2773 */
2774 {
32874aea 2775 /*
2776 * First format the key into a string.
2777 */
2778 int len = rsastr_len(&hostkey);
2779 char fingerprint[100];
3d88e64d 2780 char *keystr = snewn(len, char);
32874aea 2781 if (!keystr)
2782 fatalbox("Out of memory");
2783 rsastr_fmt(keystr, &hostkey);
2784 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2785 verify_ssh_host_key(ssh->frontend,
2786 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2787 fingerprint);
2788 sfree(keystr);
2789 }
2790
2791 for (i = 0; i < 32; i++) {
51470298 2792 s->rsabuf[i] = ssh->session_key[i];
374330e2 2793 if (i < 16)
51470298 2794 s->rsabuf[i] ^= s->session_id[i];
374330e2 2795 }
2796
2797 if (hostkey.bytes > servkey.bytes) {
0016d70b 2798 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2799 if (ret)
2800 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2801 } else {
0016d70b 2802 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2803 if (ret)
2804 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2805 }
2806 if (!ret) {
2807 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2808 crStop(0);
374330e2 2809 }
2810
c5e9c988 2811 logevent("Encrypted session key");
2812
ca20bfcf 2813 {
2814 int cipher_chosen = 0, warn = 0;
2815 char *cipher_string = NULL;
51470298 2816 int i;
ca20bfcf 2817 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2818 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2819 if (next_cipher == CIPHER_WARN) {
2820 /* If/when we choose a cipher, warn about it */
2821 warn = 1;
2822 } else if (next_cipher == CIPHER_AES) {
2823 /* XXX Probably don't need to mention this. */
2824 logevent("AES not supported in SSH1, skipping");
2825 } else {
2826 switch (next_cipher) {
51470298 2827 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2828 cipher_string = "3DES"; break;
51470298 2829 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2830 cipher_string = "Blowfish"; break;
51470298 2831 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2832 cipher_string = "single-DES"; break;
2833 }
51470298 2834 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2835 cipher_chosen = 1;
2836 }
2837 }
2838 if (!cipher_chosen) {
51470298 2839 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2840 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2841 "supporting 3DES encryption"));
2842 else
2843 /* shouldn't happen */
6b5cf8b4 2844 bombout(("No supported ciphers found"));
7ffdbc1a 2845 crStop(0);
a99a05c0 2846 }
ca20bfcf 2847
2848 /* Warn about chosen cipher if necessary. */
bb348ab1 2849 if (warn) {
2850 sk_set_frozen(ssh->s, 1);
83e7d008 2851 askalg(ssh->frontend, "cipher", cipher_string);
bb348ab1 2852 sk_set_frozen(ssh->s, 0);
2853 }
bea1ef5f 2854 }
ca20bfcf 2855
51470298 2856 switch (s->cipher_type) {
32874aea 2857 case SSH_CIPHER_3DES:
2858 logevent("Using 3DES encryption");
2859 break;
2860 case SSH_CIPHER_DES:
2861 logevent("Using single-DES encryption");
2862 break;
2863 case SSH_CIPHER_BLOWFISH:
2864 logevent("Using Blowfish encryption");
2865 break;
c5e9c988 2866 }
bea1ef5f 2867
51470298 2868 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2869 PKT_CHAR, s->cipher_type,
32874aea 2870 PKT_DATA, cookie, 8,
51470298 2871 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2872 PKT_DATA, s->rsabuf, s->len,
2873 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2874
c5e9c988 2875 logevent("Trying to enable encryption...");
374330e2 2876
51470298 2877 sfree(s->rsabuf);
374330e2 2878
51470298 2879 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2880 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2881 &ssh_3des);
371e569c 2882 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2883 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2884 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2885
0183b242 2886 ssh->crcda_ctx = crcda_make_context();
2887 logevent("Installing CRC compensation attack detector");
2888
679539d7 2889 if (servkey.modulus) {
2890 sfree(servkey.modulus);
2891 servkey.modulus = NULL;
2892 }
2893 if (servkey.exponent) {
2894 sfree(servkey.exponent);
2895 servkey.exponent = NULL;
2896 }
2897 if (hostkey.modulus) {
2898 sfree(hostkey.modulus);
2899 hostkey.modulus = NULL;
2900 }
2901 if (hostkey.exponent) {
2902 sfree(hostkey.exponent);
2903 hostkey.exponent = NULL;
2904 }
ff3187f6 2905 crWaitUntil(pktin);
374330e2 2906
ff3187f6 2907 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2908 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2909 crStop(0);
8d5de777 2910 }
374330e2 2911
c5e9c988 2912 logevent("Successfully started encryption");
2913
374330e2 2914 fflush(stdout);
2915 {
aa09f7d0 2916 if (!*ssh->cfg.username) {
c0a81592 2917 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2918 if (!ssh_get_line("login as: ",
51470298 2919 s->username, sizeof(s->username), FALSE)) {
32874aea 2920 /*
2921 * get_line failed to get a username.
2922 * Terminate.
2923 */
2924 logevent("No username provided. Abandoning session.");
3bb2f322 2925 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2926 crStop(1);
32874aea 2927 }
2928 } else {
51470298 2929 int ret; /* need not be kept over crReturn */
2930 c_write_str(ssh, "login as: ");
2931 ssh->send_ok = 1;
0405e71f 2932
51470298 2933 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2934 do {
ff3187f6 2935 crWaitUntil(!pktin);
51470298 2936 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2937 } while (ret == 0);
2938 if (ret < 0)
2939 cleanup_exit(0);
51470298 2940 c_write_str(ssh, "\r\n");
32874aea 2941 }
2942 } else {
86916870 2943 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2944 s->username[sizeof(s->username)-1] = '\0';
374330e2 2945 }
fb09bf1c 2946
51470298 2947 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2948 {
51470298 2949 char userlog[22 + sizeof(s->username)];
2950 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2951 logevent(userlog);
32874aea 2952 if (flags & FLAG_INTERACTIVE &&
2953 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2954 strcat(userlog, "\r\n");
51470298 2955 c_write_str(ssh, userlog);
3c8e959b 2956 }
c5e9c988 2957 }
374330e2 2958 }
2959
ff3187f6 2960 crWaitUntil(pktin);
374330e2 2961
51470298 2962 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2963 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2964 s->tried_publickey = s->tried_agent = 1;
0df73905 2965 } else {
51470298 2966 s->tried_publickey = s->tried_agent = 0;
0df73905 2967 }
51470298 2968 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2969 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2970 if (!filename_is_null(ssh->cfg.keyfile)) {
2971 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2972 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2973 s->publickey_blob = NULL;
396778f1 2974 } else
51470298 2975 s->publickey_blob = NULL;
7cca0d81 2976
ff3187f6 2977 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 2978 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2979
51470298 2980 if (agent_exists() && !s->tried_agent) {
32874aea 2981 /*
2982 * Attempt RSA authentication using Pageant.
2983 */
32874aea 2984 void *r;
2985
51470298 2986 s->authed = FALSE;
2987 s->tried_agent = 1;
32874aea 2988 logevent("Pageant is running. Requesting keys.");
2989
2990 /* Request the keys held by the agent. */
51470298 2991 PUT_32BIT(s->request, 1);
2992 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2993 if (!agent_query(s->request, 5, &r, &s->responselen,
2994 ssh_agent_callback, ssh)) {
2995 do {
2996 crReturn(0);
ff3187f6 2997 if (pktin) {
839f10db 2998 bombout(("Unexpected data from server while waiting"
2999 " for agent response"));
3000 crStop(0);
3001 }
ff3187f6 3002 } while (pktin || inlen > 0);
839f10db 3003 r = ssh->agent_response;
3004 s->responselen = ssh->agent_response_len;
3005 }
51470298 3006 s->response = (unsigned char *) r;
3007 if (s->response && s->responselen >= 5 &&
3008 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3009 s->p = s->response + 5;
3010 s->nkeys = GET_32BIT(s->p);
3011 s->p += 4;
32874aea 3012 {
3013 char buf[64];
51470298 3014 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 3015 logevent(buf);
3016 }
51470298 3017 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 3018 {
3019 char buf[64];
51470298 3020 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 3021 logevent(buf);
3022 }
51470298 3023 if (s->publickey_blob &&
3024 !memcmp(s->p, s->publickey_blob,
3025 s->publickey_bloblen)) {
396778f1 3026 logevent("This key matches configured key file");
51470298 3027 s->tried_publickey = 1;
396778f1 3028 }
51470298 3029 s->p += 4;
0016d70b 3030 {
3031 int n, ok = FALSE;
3032 do { /* do while (0) to make breaking easy */
3033 n = ssh1_read_bignum
3034 (s->p, s->responselen-(s->p-s->response),
3035 &s->key.exponent);
3036 if (n < 0)
3037 break;
3038 s->p += n;
3039 n = ssh1_read_bignum
3040 (s->p, s->responselen-(s->p-s->response),
3041 &s->key.modulus);
3042 if (n < 0)
3043 break;
3044 s->p += n;
3045 if (s->responselen - (s->p-s->response) < 4)
3046 break;
3047 s->commentlen = GET_32BIT(s->p);
3048 s->p += 4;
3049 if (s->responselen - (s->p-s->response) <
3050 s->commentlen)
3051 break;
3052 s->commentp = (char *)s->p;
3053 s->p += s->commentlen;
3054 ok = TRUE;
3055 } while (0);
3056 if (!ok) {
3057 logevent("Pageant key list packet was truncated");
3058 break;
3059 }
3060 }
51470298 3061 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3062 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3063 crWaitUntil(pktin);
3064 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3065 logevent("Key refused");
3066 continue;
3067 }
3068 logevent("Received RSA challenge");
ff3187f6 3069 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3070 bombout(("Server's RSA challenge was badly formatted"));
3071 crStop(0);
3072 }
3073
32874aea 3074 {
3075 char *agentreq, *q, *ret;
2d466ffd 3076 void *vret;
32874aea 3077 int len, retlen;
3078 len = 1 + 4; /* message type, bit count */
51470298 3079 len += ssh1_bignum_length(s->key.exponent);
3080 len += ssh1_bignum_length(s->key.modulus);
3081 len += ssh1_bignum_length(s->challenge);
32874aea 3082 len += 16; /* session id */
3083 len += 4; /* response format */
3d88e64d 3084 agentreq = snewn(4 + len, char);
32874aea 3085 PUT_32BIT(agentreq, len);
3086 q = agentreq + 4;
3087 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3088 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3089 q += 4;
51470298 3090 q += ssh1_write_bignum(q, s->key.exponent);
3091 q += ssh1_write_bignum(q, s->key.modulus);
3092 q += ssh1_write_bignum(q, s->challenge);
3093 memcpy(q, s->session_id, 16);
32874aea 3094 q += 16;
3095 PUT_32BIT(q, 1); /* response format */
839f10db 3096 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3097 ssh_agent_callback, ssh)) {
3098 sfree(agentreq);
3099 do {
3100 crReturn(0);
ff3187f6 3101 if (pktin) {
839f10db 3102 bombout(("Unexpected data from server"
3103 " while waiting for agent"
3104 " response"));
3105 crStop(0);
3106 }
ff3187f6 3107 } while (pktin || inlen > 0);
839f10db 3108 vret = ssh->agent_response;
3109 retlen = ssh->agent_response_len;
3110 } else
3111 sfree(agentreq);
2d466ffd 3112 ret = vret;
32874aea 3113 if (ret) {
3114 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3115 logevent("Sending Pageant's response");
51470298 3116 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3117 PKT_DATA, ret + 5, 16,
3118 PKT_END);
3119 sfree(ret);
ff3187f6 3120 crWaitUntil(pktin);
3121 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3122 logevent
3123 ("Pageant's response accepted");
3124 if (flags & FLAG_VERBOSE) {
51470298 3125 c_write_str(ssh, "Authenticated using"
3126 " RSA key \"");
3127 c_write(ssh, s->commentp,
3128 s->commentlen);
3129 c_write_str(ssh, "\" from agent\r\n");
32874aea 3130 }
51470298 3131 s->authed = TRUE;
32874aea 3132 } else
3133 logevent
3134 ("Pageant's response not accepted");
3135 } else {
3136 logevent
3137 ("Pageant failed to answer challenge");
3138 sfree(ret);
3139 }
3140 } else {
3141 logevent("No reply received from Pageant");
3142 }
3143 }
51470298 3144 freebn(s->key.exponent);
3145 freebn(s->key.modulus);
3146 freebn(s->challenge);
3147 if (s->authed)
32874aea 3148 break;
3149 }
29b1d0b3 3150 sfree(s->response);
32874aea 3151 }
51470298 3152 if (s->authed)
32874aea 3153 break;
3154 }
9a30e26b 3155 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3156 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3157
86916870 3158 if (ssh->cfg.try_tis_auth &&
51470298 3159 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3160 !s->tis_auth_refused) {
3161 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3162 logevent("Requested TIS authentication");
51470298 3163 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3164 crWaitUntil(pktin);
3165 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3166 logevent("TIS authentication declined");
3167 if (flags & FLAG_INTERACTIVE)
51470298 3168 c_write_str(ssh, "TIS authentication refused.\r\n");
3169 s->tis_auth_refused = 1;
614a20a0 3170 continue;
32874aea 3171 } else {
0016d70b 3172 char *challenge;
3173 int challengelen;
3174
ff3187f6 3175 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3176 if (!challenge) {
3177 bombout(("TIS challenge packet was badly formed"));
3178 crStop(0);
3179 }
32874aea 3180 logevent("Received TIS challenge");
51470298 3181 if (challengelen > sizeof(s->prompt) - 1)
3182 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3183 memcpy(s->prompt, challenge, challengelen);
614a20a0 3184 /* Prompt heuristic comes from OpenSSH */
51470298 3185 strncpy(s->prompt + challengelen,
3186 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3187 "": "\r\nResponse: ",
51470298 3188 (sizeof s->prompt) - challengelen);
3189 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3190 }
3191 }
86916870 3192 if (ssh->cfg.try_tis_auth &&
51470298 3193 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3194 !s->ccard_auth_refused) {
3195 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3196 logevent("Requested CryptoCard authentication");
51470298 3197 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3198 crWaitUntil(pktin);
3199 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3200 logevent("CryptoCard authentication declined");
51470298 3201 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3202 s->ccard_auth_refused = 1;
614a20a0 3203 continue;
32874aea 3204 } else {
0016d70b 3205 char *challenge;
3206 int challengelen;
3207
ff3187f6 3208 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3209 if (!challenge) {
3210 bombout(("CryptoCard challenge packet was badly formed"));
3211 crStop(0);
3212 }
32874aea 3213 logevent("Received CryptoCard challenge");
51470298 3214 if (challengelen > sizeof(s->prompt) - 1)
3215 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3216 memcpy(s->prompt, challenge, challengelen);
51470298 3217 strncpy(s->prompt + challengelen,
3218 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3219 "" : "\r\nResponse: ",
51470298 3220 sizeof(s->prompt) - challengelen);
3221 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3222 }
3223 }
51470298 3224 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3225 sprintf(s->prompt, "%.90s@%.90s's password: ",
3226 s->username, ssh->savedhost);
32874aea 3227 }
51470298 3228 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3229 char *comment = NULL;
231ee168 3230 int type;
3231 char msgbuf[256];
32874aea 3232 if (flags & FLAG_VERBOSE)
51470298 3233 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3234 logeventf(ssh, "Trying public key \"%s\"",
3235 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3236 type = key_type(&ssh->cfg.keyfile);
231ee168 3237 if (type != SSH_KEYTYPE_SSH1) {
3238 sprintf(msgbuf, "Key is of wrong type (%s)",
3239 key_type_to_str(type));
3240 logevent(msgbuf);
51470298 3241 c_write_str(ssh, msgbuf);
3242 c_write_str(ssh, "\r\n");
3243 s->tried_publickey = 1;
231ee168 3244 continue;
3245 }
9a30e26b 3246 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3247 if (flags & FLAG_VERBOSE)
51470298 3248 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3249 goto tryauth;
3250 }
51470298 3251 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3252 sfree(comment);
3253 }
a52f067e 3254
614a20a0 3255 /*
3256 * Show password prompt, having first obtained it via a TIS
3257 * or CryptoCard exchange if we're doing TIS or CryptoCard
3258 * authentication.
3259 */
fa17a66e 3260 if (ssh_get_line) {
51470298 3261 if (!ssh_get_line(s->prompt, s->password,
3262 sizeof(s->password), TRUE)) {
32874aea 3263 /*
3264 * get_line failed to get a password (for example
3265 * because one was supplied on the command line
3266 * which has already failed to work). Terminate.
3267 */
51470298 3268 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3269 PKT_STR, "No more passwords available to try",
3270 PKT_END);
247308b5 3271 logevent("Unable to authenticate");
a8327734 3272 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3273 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3274 crStop(1);
32874aea 3275 }
fb09bf1c 3276 } else {
614a20a0 3277 /* Prompt may have come from server. We've munged it a bit, so
3278 * we know it to be zero-terminated at least once. */
51470298 3279 int ret; /* need not be saved over crReturn */
3280 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3281 s->pos = 0;
0405e71f 3282
51470298 3283 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3284 do {
ff3187f6 3285 crWaitUntil(!pktin);
51470298 3286 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3287 } while (ret == 0);
3288 if (ret < 0)
3289 cleanup_exit(0);
51470298 3290 c_write_str(ssh, "\r\n");
32874aea 3291 }
3292
3293 tryauth:
51470298 3294 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3295 /*
3296 * Try public key authentication with the specified
3297 * key file.
3298 */
51470298 3299 s->tried_publickey = 1;
3300
3301 {
222d54dc 3302 const char *error = NULL;
3303 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3304 &error);
51470298 3305 if (ret == 0) {
3306 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3307 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3308 c_write_str(ssh, " (");
3309 c_write_str(ssh, error);
3310 c_write_str(ssh, ").\r\n");
51470298 3311 continue; /* go and try password */
3312 }
3313 if (ret == -1) {
3314 c_write_str(ssh, "Wrong passphrase.\r\n");
3315 s->tried_publickey = 0;
3316 continue; /* try again */
3317 }
32874aea 3318 }
3319
3320 /*
3321 * Send a public key attempt.
3322 */
51470298 3323 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3324 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3325
ff3187f6 3326 crWaitUntil(pktin);
3327 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3328 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3329 continue; /* go and try password */
3330 }
ff3187f6 3331 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3332 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3333 crStop(0);
32874aea 3334 }
32874aea 3335
51470298 3336 {
3337 int i;
3338 unsigned char buffer[32];
3339 Bignum challenge, response;
3340
ff3187f6 3341 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3342 bombout(("Server's RSA challenge was badly formatted"));
3343 crStop(0);
3344 }
51470298 3345 response = rsadecrypt(challenge, &s->key);
3346 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3347
51470298 3348 for (i = 0; i < 32; i++) {
3349 buffer[i] = bignum_byte(response, 31 - i);
3350 }
3351
3352 MD5Init(&md5c);
3353 MD5Update(&md5c, buffer, 32);
3354 MD5Update(&md5c, s->session_id, 16);
3355 MD5Final(buffer, &md5c);
32874aea 3356
51470298 3357 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3358 PKT_DATA, buffer, 16, PKT_END);
3359
3360 freebn(challenge);
3361 freebn(response);
3362 }
32874aea 3363
ff3187f6 3364 crWaitUntil(pktin);
3365 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3366 if (flags & FLAG_VERBOSE)
51470298 3367 c_write_str(ssh, "Failed to authenticate with"
3368 " our public key.\r\n");
32874aea 3369 continue; /* go and try password */
ff3187f6 3370 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3371 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3372 crStop(0);
32874aea 3373 }
3374
3375 break; /* we're through! */
3376 } else {
51470298 3377 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3378 /*
3379 * Defence against traffic analysis: we send a
3380 * whole bunch of packets containing strings of
3381 * different lengths. One of these strings is the
3382 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3383 * The others are all random data in
3384 * SSH1_MSG_IGNORE packets. This way a passive
3385 * listener can't tell which is the password, and
3386 * hence can't deduce the password length.
3387 *
3388 * Anybody with a password length greater than 16
3389 * bytes is going to have enough entropy in their
3390 * password that a listener won't find it _that_
3391 * much help to know how long it is. So what we'll
3392 * do is:
3393 *
3394 * - if password length < 16, we send 15 packets
3395 * containing string lengths 1 through 15
3396 *
3397 * - otherwise, we let N be the nearest multiple
3398 * of 8 below the password length, and send 8
3399 * packets containing string lengths N through
3400 * N+7. This won't obscure the order of
3401 * magnitude of the password length, but it will
3402 * introduce a bit of extra uncertainty.
3403 *
3404 * A few servers (the old 1.2.18 through 1.2.22)
3405 * can't deal with SSH1_MSG_IGNORE. For these
3406 * servers, we need an alternative defence. We make
3407 * use of the fact that the password is interpreted
3408 * as a C string: so we can append a NUL, then some
3409 * random data.
bd358db1 3410 *
3411 * One server (a Cisco one) can deal with neither
3412 * SSH1_MSG_IGNORE _nor_ a padded password string.
3413 * For this server we are left with no defences
3414 * against password length sniffing.
32874aea 3415 */
51470298 3416 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3417 /*
3418 * The server can deal with SSH1_MSG_IGNORE, so
3419 * we can use the primary defence.
3420 */
32874aea 3421 int bottom, top, pwlen, i;
3422 char *randomstr;
3423
51470298 3424 pwlen = strlen(s->password);
32874aea 3425 if (pwlen < 16) {
3426 bottom = 0; /* zero length passwords are OK! :-) */
3427 top = 15;
3428 } else {
3429 bottom = pwlen & ~7;
3430 top = bottom + 7;
3431 }
3432
3433 assert(pwlen >= bottom && pwlen <= top);
3434
3d88e64d 3435 randomstr = snewn(top + 1, char);
32874aea 3436
3437 for (i = bottom; i <= top; i++) {
9a10ecf4 3438 if (i == pwlen) {
51470298 3439 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3440 PKTT_PASSWORD, PKT_STR, s->password,
3441 PKTT_OTHER, PKT_END);
3442 } else {
32874aea 3443 for (j = 0; j < i; j++) {
3444 do {
3445 randomstr[j] = random_byte();
3446 } while (randomstr[j] == '\0');
3447 }
3448 randomstr[i] = '\0';
51470298 3449 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3450 PKT_STR, randomstr, PKT_END);
3451 }
3452 }
bd358db1 3453 logevent("Sending password with camouflage packets");
51470298 3454 ssh_pkt_defersend(ssh);
679539d7 3455 sfree(randomstr);
bd358db1 3456 }
51470298 3457 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3458 /*
3459 * The server can't deal with SSH1_MSG_IGNORE
3460 * but can deal with padded passwords, so we
3461 * can use the secondary defence.
3462 */
bd358db1 3463 char string[64];
51470298 3464 char *ss;
bd358db1 3465 int len;
3466
51470298 3467 len = strlen(s->password);
bd358db1 3468 if (len < sizeof(string)) {
51470298 3469 ss = string;
3470 strcpy(string, s->password);
bd358db1 3471 len++; /* cover the zero byte */
3472 while (len < sizeof(string)) {
3473 string[len++] = (char) random_byte();
3474 }
3475 } else {
51470298 3476 ss = s->password;
bd358db1 3477 }
3478 logevent("Sending length-padded password");
9a10ecf4 3479 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3480 PKT_INT, len, PKT_DATA, ss, len,
3481 PKTT_OTHER, PKT_END);
bd358db1 3482 } else {
3483 /*
3484 * The server has _both_
3485 * BUG_CHOKES_ON_SSH1_IGNORE and
3486 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3487 * therefore nothing we can do.
3488 */
3489 int len;
51470298 3490 len = strlen(s->password);
bd358db1 3491 logevent("Sending unpadded password");
9a10ecf4 3492 send_packet(ssh, s->pwpkt_type,
3493 PKTT_PASSWORD, PKT_INT, len,
3494 PKT_DATA, s->password, len,
3495 PKTT_OTHER, PKT_END);
32874aea 3496 }
3497 } else {
9a10ecf4 3498 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3499 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3500 }
3501 }
c5e9c988 3502 logevent("Sent password");
51470298 3503 memset(s->password, 0, strlen(s->password));
ff3187f6 3504 crWaitUntil(pktin);
3505 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3506 if (flags & FLAG_VERBOSE)
51470298 3507 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3508 logevent("Authentication refused");
ff3187f6 3509 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3510 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3511 crStop(0);
374330e2 3512 }
3513 }
3514
c5e9c988 3515 logevent("Authentication successful");
3516
fb09bf1c 3517 crFinish(1);
3518}
3519
32874aea 3520void sshfwd_close(struct ssh_channel *c)
3521{
51470298 3522 Ssh ssh = c->ssh;
3523
36f94d1f 3524 if (ssh->state != SSH_STATE_SESSION) {
3525 assert(ssh->state == SSH_STATE_CLOSED);
3526 return;
3527 }
3528
80e48603 3529 if (c && !c->closes) {
4ed34d25 3530 /*
3531 * If the channel's remoteid is -1, we have sent
3532 * CHANNEL_OPEN for this channel, but it hasn't even been
3533 * acknowledged by the server. So we must set a close flag
3534 * on it now, and then when the server acks the channel
3535 * open, we can close it then.
3536 */
36cac739 3537 if (((int)c->remoteid) != -1) {
51470298 3538 if (ssh->version == 1) {
3539 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3540 PKT_END);
3541 } else {
ff3187f6 3542 struct Packet *pktout;
3543 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3544 ssh2_pkt_adduint32(pktout, c->remoteid);
3545 ssh2_pkt_send(ssh, pktout);
4ed34d25 3546 }
32874aea 3547 }
0357890f 3548 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3549 if (c->type == CHAN_X11) {
3550 c->u.x11.s = NULL;
d74d141c 3551 logevent("Forwarded X11 connection terminated");
4ed34d25 3552 } else if (c->type == CHAN_SOCKDATA ||
3553 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3554 c->u.pfd.s = NULL;
3555 logevent("Forwarded port closed");
32874aea 3556 }
3557 }
3558}
3559
5471d09a 3560int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3561{
51470298 3562 Ssh ssh = c->ssh;
3563
36f94d1f 3564 if (ssh->state != SSH_STATE_SESSION) {
3565 assert(ssh->state == SSH_STATE_CLOSED);
3566 return 0;
3567 }
3568
51470298 3569 if (ssh->version == 1) {
3570 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3571 PKT_INT, c->remoteid,
9a10ecf4 3572 PKTT_DATA,
3573 PKT_INT, len, PKT_DATA, buf, len,
3574 PKTT_OTHER, PKT_END);
5471d09a 3575 /*
3576 * In SSH1 we can return 0 here - implying that forwarded
3577 * connections are never individually throttled - because
3578 * the only circumstance that can cause throttling will be
3579 * the whole SSH connection backing up, in which case
3580 * _everything_ will be throttled as a whole.
3581 */
3582 return 0;
783415f8 3583 } else {
32874aea 3584 ssh2_add_channel_data(c, buf, len);
5471d09a 3585 return ssh2_try_send(c);
3586 }
3587}
3588
3589void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3590{
51470298 3591 Ssh ssh = c->ssh;
3592
36f94d1f 3593 if (ssh->state != SSH_STATE_SESSION) {
3594 assert(ssh->state == SSH_STATE_CLOSED);
3595 return;
3596 }
3597
51470298 3598 if (ssh->version == 1) {
5471d09a 3599 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3600 c->v.v1.throttling = 0;
51470298 3601 ssh1_throttle(ssh, -1);
5471d09a 3602 }
3603 } else {
3604 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3605 }
9c964e85 3606}
3607
06fadff5 3608static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3609{
3610 struct queued_handler *qh = ssh->qhead;
3611
3612 assert(qh != NULL);
3613
3614 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3615
3616 if (qh->msg1 > 0) {
3617 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3618 ssh->packet_dispatch[qh->msg1] = NULL;
3619 }
3620 if (qh->msg2 > 0) {
3621 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3622 ssh->packet_dispatch[qh->msg2] = NULL;
3623 }
3624
3625 if (qh->next) {
3626 ssh->qhead = qh->next;
3627
3628 if (ssh->qhead->msg1 > 0) {
3629 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3630 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3631 }
3632 if (ssh->qhead->msg2 > 0) {
3633 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3634 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3635 }
3636 } else {
3637 ssh->qhead = ssh->qtail = NULL;
3638 ssh->packet_dispatch[pktin->type] = NULL;
3639 }
3640
3641 qh->handler(ssh, pktin, qh->ctx);
3642
3643 sfree(qh);
3644}
3645
3646static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3647 chandler_fn_t handler, void *ctx)
3648{
3649 struct queued_handler *qh;
3650
3651 qh = snew(struct queued_handler);
3652 qh->msg1 = msg1;
3653 qh->msg2 = msg2;
3654 qh->handler = handler;
3655 qh->ctx = ctx;
3656 qh->next = NULL;
3657
3658 if (ssh->qtail == NULL) {
3659 ssh->qhead = qh;
3660
3661 if (qh->msg1 > 0) {
3662 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3663 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3664 }
3665 if (qh->msg2 > 0) {
3666 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3667 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3668 }
3669 } else {
3670 ssh->qtail->next = qh;
3671 }
3672 ssh->qtail = qh;
3673}
3674
3675static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3676{
3677 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3678
3679 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3680 SSH2_MSG_REQUEST_SUCCESS)) {
3681 logeventf(ssh, "Remote port forwarding from %s enabled",
3682 pf->sportdesc);
3683 } else {
3684 logeventf(ssh, "Remote port forwarding from %s refused",
3685 pf->sportdesc);
3686
3687 rpf = del234(ssh->rportfwds, pf);
3688 assert(rpf == pf);
fda2feb1 3689 free_rportfwd(pf);
06fadff5 3690 }
3691}
3692
3693static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3694{
84328ddb 3695 const char *portfwd_strptr = cfg->portfwd;
3696 struct ssh_portfwd *epf;
3697 int i;
06fadff5 3698
fda2feb1 3699 if (!ssh->portfwds) {
3700 ssh->portfwds = newtree234(ssh_portcmp);
3701 } else {
3702 /*
3703 * Go through the existing port forwardings and tag them
84328ddb 3704 * with status==DESTROY. Any that we want to keep will be
3705 * re-enabled (status==KEEP) as we go through the
3706 * configuration and find out which bits are the same as
3707 * they were before.
fda2feb1 3708 */
3709 struct ssh_portfwd *epf;
3710 int i;
3711 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 3712 epf->status = DESTROY;
fda2feb1 3713 }
3714
06fadff5 3715 while (*portfwd_strptr) {
84328ddb 3716 char address_family, type;
3717 int sport,dport,sserv,dserv;
3718 char sports[256], dports[256], saddr[256], host[256];
3719 int n;
3720
05581745 3721 address_family = 'A';
3722 type = 'L';
84328ddb 3723 if (*portfwd_strptr == 'A' ||
3724 *portfwd_strptr == '4' ||
3725 *portfwd_strptr == '6')
3726 address_family = *portfwd_strptr++;
3727 if (*portfwd_strptr == 'L' ||
3728 *portfwd_strptr == 'R' ||
3729 *portfwd_strptr == 'D')
3730 type = *portfwd_strptr++;
05581745 3731
06fadff5 3732 saddr[0] = '\0';
05581745 3733
06fadff5 3734 n = 0;
3735 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3736 if (*portfwd_strptr == ':') {
3737 /*
3738 * We've seen a colon in the middle of the
3739 * source port number. This means that
3740 * everything we've seen until now is the
3741 * source _address_, so we'll move it into
3742 * saddr and start sports from the beginning
3743 * again.
3744 */
3745 portfwd_strptr++;
3746 sports[n] = '\0';
3747 if (ssh->version == 1 && type == 'R') {
3748 logeventf(ssh, "SSH1 cannot handle remote source address "
3749 "spec \"%s\"; ignoring", sports);
3750 } else
3751 strcpy(saddr, sports);
3752 n = 0;
3753 }
3754 if (n < 255) sports[n++] = *portfwd_strptr++;
3755 }
3756 sports[n] = 0;
3757 if (type != 'D') {
3758 if (*portfwd_strptr == '\t')
3759 portfwd_strptr++;
3760 n = 0;
3761 while (*portfwd_strptr && *portfwd_strptr != ':') {
3762 if (n < 255) host[n++] = *portfwd_strptr++;
3763 }
3764 host[n] = 0;
3765 if (*portfwd_strptr == ':')
3766 portfwd_strptr++;
3767 n = 0;
3768 while (*portfwd_strptr) {
3769 if (n < 255) dports[n++] = *portfwd_strptr++;
3770 }
3771 dports[n] = 0;
3772 portfwd_strptr++;
3773 dport = atoi(dports);
3774 dserv = 0;
3775 if (dport == 0) {
3776 dserv = 1;
3777 dport = net_service_lookup(dports);
3778 if (!dport) {
3779 logeventf(ssh, "Service lookup failed for destination"
3780 " port \"%s\"", dports);
3781 }
3782 }
3783 } else {
3784 while (*portfwd_strptr) portfwd_strptr++;
3785 dport = dserv = -1;
3786 portfwd_strptr++; /* eat the NUL and move to next one */
3787 }
3788 sport = atoi(sports);
3789 sserv = 0;
3790 if (sport == 0) {
3791 sserv = 1;
3792 sport = net_service_lookup(sports);
3793 if (!sport) {
3794 logeventf(ssh, "Service lookup failed for source"
3795 " port \"%s\"", sports);
3796 }
3797 }
3798 if (sport && dport) {
3799 /* Set up a description of the source port. */
fda2feb1 3800 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 3801
3802 pfrec = snew(struct ssh_portfwd);
3803 pfrec->type = type;
3804 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 3805 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 3806 pfrec->sport = sport;
84328ddb 3807 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 3808 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 3809 pfrec->dport = dport;
3810 pfrec->local = NULL;
3811 pfrec->remote = NULL;
05581745 3812 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3813 address_family == '6' ? ADDRTYPE_IPV6 :
3814 ADDRTYPE_UNSPEC);
fda2feb1 3815
3816 epfrec = add234(ssh->portfwds, pfrec);
3817 if (epfrec != pfrec) {
3818 /*
3819 * We already have a port forwarding with precisely
3820 * these parameters. Hence, no need to do anything;
84328ddb 3821 * simply tag the existing one as KEEP.
fda2feb1 3822 */
84328ddb 3823 epfrec->status = KEEP;
fda2feb1 3824 free_portfwd(pfrec);
84328ddb 3825 } else {
3826 pfrec->status = CREATE;
3827 }
3828 }
3829 }
3830
3831 /*
3832 * Now go through and destroy any port forwardings which were
3833 * not re-enabled.
3834 */
3835 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3836 if (epf->status == DESTROY) {
3837 char *message;
3838
3839 message = dupprintf("%s port forwarding from %s%s%d",
3840 epf->type == 'L' ? "local" :
3841 epf->type == 'R' ? "remote" : "dynamic",
3842 epf->saddr ? epf->saddr : "",
3843 epf->saddr ? ":" : "",
3844 epf->sport);
3845
3846 if (epf->type != 'D') {
3847 char *msg2 = dupprintf("%s to %s:%d", message,
3848 epf->daddr, epf->dport);
3849 sfree(message);
3850 message = msg2;
3851 }
3852
3853 logeventf(ssh, "Cancelling %s", message);
3854 sfree(message);
3855
3856 if (epf->remote) {
3857 struct ssh_rportfwd *rpf = epf->remote;
3858 struct Packet *pktout;
3859
3860 /*
3861 * Cancel the port forwarding at the server
3862 * end.
3863 */
3864 if (ssh->version == 1) {
3865 /*
3866 * We cannot cancel listening ports on the
3867 * server side in SSH1! There's no message
3868 * to support it. Instead, we simply remove
3869 * the rportfwd record from the local end
3870 * so that any connections the server tries
3871 * to make on it are rejected.
3872 */
3873 } else {
3874 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3875 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3876 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3877 if (epf->saddr) {
3878 ssh2_pkt_addstring(pktout, epf->saddr);
3879 } else if (ssh->cfg.rport_acceptall) {
3880 ssh2_pkt_addstring(pktout, "0.0.0.0");
3881 } else {
3882 ssh2_pkt_addstring(pktout, "127.0.0.1");
3883 }
3884 ssh2_pkt_adduint32(pktout, epf->sport);
3885 ssh2_pkt_send(ssh, pktout);
3886 }
3887
3888 del234(ssh->rportfwds, rpf);
3889 free_rportfwd(rpf);
3890 } else if (epf->local) {
3891 pfd_terminate(epf->local);
3892 }
3893
3894 delpos234(ssh->portfwds, i);
3895 free_portfwd(epf);
3896 i--; /* so we don't skip one in the list */
3897 }
3898
3899 /*
3900 * And finally, set up any new port forwardings (status==CREATE).
3901 */
3902 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3903 if (epf->status == CREATE) {
3904 char *sportdesc, *dportdesc;
3fe92132 3905 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 3906 epf->saddr ? epf->saddr : "",
3907 epf->saddr ? ":" : "",
3fe92132 3908 epf->sserv ? epf->sserv : "",
3909 epf->sserv ? "(" : "",
3910 epf->sport,
3911 epf->sserv ? ")" : "");
84328ddb 3912 if (epf->type == 'D') {
3913 dportdesc = NULL;
3914 } else {
3fe92132 3915 dportdesc = dupprintf("%s:%s%s%d%s",
3916 epf->daddr,
3917 epf->dserv ? epf->dserv : "",
3918 epf->dserv ? "(" : "",
3919 epf->dport,
3920 epf->dserv ? ")" : "");
84328ddb 3921 }
05581745 3922
84328ddb 3923 if (epf->type == 'L') {
3924 const char *err = pfd_addforward(epf->daddr, epf->dport,
3925 epf->saddr, epf->sport,
3926 ssh, &ssh->cfg,
3927 &epf->local,
3928 epf->addressfamily);
3929
3930 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3931 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3932 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3933 sportdesc, dportdesc,
3934 err ? " failed: " : "", err ? err : "");
3935 } else if (epf->type == 'D') {
06fadff5 3936 const char *err = pfd_addforward(NULL, -1,
84328ddb 3937 epf->saddr, epf->sport,
3938 ssh, &ssh->cfg,
3939 &epf->local,
3940 epf->addressfamily);
3941
3942 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3943 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3944 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3945 sportdesc,
3946 err ? " failed: " : "", err ? err : "");
06fadff5 3947 } else {
3948 struct ssh_rportfwd *pf;
3949
3950 /*
3951 * Ensure the remote port forwardings tree exists.
3952 */
3953 if (!ssh->rportfwds) {
3954 if (ssh->version == 1)
3955 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3956 else
3957 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3958 }
3959
3960 pf = snew(struct ssh_rportfwd);
84328ddb 3961 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
3962 pf->dhost[lenof(pf->dhost)-1] = '\0';
3963 pf->dport = epf->dport;
3964 pf->sport = epf->sport;
06fadff5 3965 if (add234(ssh->rportfwds, pf) != pf) {
3966 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 3967 epf->daddr, epf->dport);
06fadff5 3968 sfree(pf);
3969 } else {
3970 logeventf(ssh, "Requesting remote port %s"
84328ddb 3971 " forward to %s", sportdesc, dportdesc);
06fadff5 3972
3973 pf->sportdesc = sportdesc;
3974 sportdesc = NULL;
84328ddb 3975 epf->remote = pf;
3976 pf->pfrec = epf;
06fadff5 3977
3978 if (ssh->version == 1) {
3979 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 3980 PKT_INT, epf->sport,
3981 PKT_STR, epf->daddr,
3982 PKT_INT, epf->dport,
06fadff5 3983 PKT_END);
3984 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
3985 SSH1_SMSG_FAILURE,
3986 ssh_rportfwd_succfail, pf);
3987 } else {
3988 struct Packet *pktout;
3989 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3990 ssh2_pkt_addstring(pktout, "tcpip-forward");
3991 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 3992 if (epf->saddr) {
3993 ssh2_pkt_addstring(pktout, epf->saddr);
06fadff5 3994 } else if (ssh->cfg.rport_acceptall) {
3995 ssh2_pkt_addstring(pktout, "0.0.0.0");
3996 } else {
3997 ssh2_pkt_addstring(pktout, "127.0.0.1");
3998 }
84328ddb 3999 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4000 ssh2_pkt_send(ssh, pktout);
4001
4002 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4003 SSH2_MSG_REQUEST_FAILURE,
4004 ssh_rportfwd_succfail, pf);
4005 }
4006 }
4007 }
4008 sfree(sportdesc);
84328ddb 4009 sfree(dportdesc);
06fadff5 4010 }
06fadff5 4011}
4012
51df0ab5 4013static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4014{
4015 char *string;
4016 int stringlen, bufsize;
4017
4018 ssh_pkt_getstring(pktin, &string, &stringlen);
4019 if (string == NULL) {
4020 bombout(("Incoming terminal data packet was badly formed"));
4021 return;
4022 }
4023
4024 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4025 string, stringlen);
4026 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4027 ssh->v1_stdout_throttling = 1;
4028 ssh1_throttle(ssh, +1);
4029 }
4030}
4031
4032static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4033{
4034 /* Remote side is trying to open a channel to talk to our
4035 * X-Server. Give them back a local channel number. */
4036 struct ssh_channel *c;
4037 int remoteid = ssh_pkt_getuint32(pktin);
4038
4039 logevent("Received X11 connect request");
4040 /* Refuse if X11 forwarding is disabled. */
4041 if (!ssh->X11_fwd_enabled) {
4042 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4043 PKT_INT, remoteid, PKT_END);
4044 logevent("Rejected X11 connect request");
4045 } else {
4046 c = snew(struct ssh_channel);
4047 c->ssh = ssh;
4048
4049 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4050 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4051 logevent("Opening X11 forward connection failed");
4052 sfree(c);
4053 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4054 PKT_INT, remoteid, PKT_END);
4055 } else {
4056 logevent
4057 ("Opening X11 forward connection succeeded");
4058 c->remoteid = remoteid;
4059 c->localid = alloc_channel_id(ssh);
4060 c->closes = 0;
4061 c->v.v1.throttling = 0;
4062 c->type = CHAN_X11; /* identify channel type */
4063 add234(ssh->channels, c);
4064 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4065 PKT_INT, c->remoteid, PKT_INT,
4066 c->localid, PKT_END);
4067 logevent("Opened X11 forward channel");
4068 }
4069 }
4070}
4071
4072static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4073{
4074 /* Remote side is trying to open a channel to talk to our
4075 * agent. Give them back a local channel number. */
4076 struct ssh_channel *c;
4077 int remoteid = ssh_pkt_getuint32(pktin);
4078
4079 /* Refuse if agent forwarding is disabled. */
4080 if (!ssh->agentfwd_enabled) {
4081 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4082 PKT_INT, remoteid, PKT_END);
4083 } else {
4084 c = snew(struct ssh_channel);
4085 c->ssh = ssh;
4086 c->remoteid = remoteid;
4087 c->localid = alloc_channel_id(ssh);
4088 c->closes = 0;
4089 c->v.v1.throttling = 0;
4090 c->type = CHAN_AGENT; /* identify channel type */
4091 c->u.a.lensofar = 0;
4092 add234(ssh->channels, c);
4093 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4094 PKT_INT, c->remoteid, PKT_INT, c->localid,
4095 PKT_END);
4096 }
4097}
4098
4099static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4100{
4101 /* Remote side is trying to open a channel to talk to a
4102 * forwarded port. Give them back a local channel number. */
4103 struct ssh_channel *c;
05581745 4104 struct ssh_rportfwd pf, *pfp;
51df0ab5 4105 int remoteid;
4106 int hostsize, port;
4107 char *host, buf[1024];
4108 const char *e;
4109 c = snew(struct ssh_channel);
4110 c->ssh = ssh;
4111
4112 remoteid = ssh_pkt_getuint32(pktin);
4113 ssh_pkt_getstring(pktin, &host, &hostsize);
4114 port = ssh_pkt_getuint32(pktin);
4115
4116 if (hostsize >= lenof(pf.dhost))
4117 hostsize = lenof(pf.dhost)-1;
4118 memcpy(pf.dhost, host, hostsize);
4119 pf.dhost[hostsize] = '\0';
4120 pf.dport = port;
05581745 4121 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4122
05581745 4123 if (pfp == NULL) {
51df0ab5 4124 sprintf(buf, "Rejected remote port open request for %s:%d",
4125 pf.dhost, port);
4126 logevent(buf);
4127 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4128 PKT_INT, remoteid, PKT_END);
4129 } else {
4130 sprintf(buf, "Received remote port open request for %s:%d",
4131 pf.dhost, port);
4132 logevent(buf);
4133 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4134 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4135 if (e != NULL) {
4136 char buf[256];
4137 sprintf(buf, "Port open failed: %s", e);
4138 logevent(buf);
4139 sfree(c);
4140 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4141 PKT_INT, remoteid, PKT_END);
4142 } else {
4143 c->remoteid = remoteid;
4144 c->localid = alloc_channel_id(ssh);
4145 c->closes = 0;
4146 c->v.v1.throttling = 0;
4147 c->type = CHAN_SOCKDATA; /* identify channel type */
4148 add234(ssh->channels, c);
4149 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4150 PKT_INT, c->remoteid, PKT_INT,
4151 c->localid, PKT_END);
4152 logevent("Forwarded port opened successfully");
4153 }
4154 }
4155}
4156
4157static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4158{
4159 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4160 unsigned int localid = ssh_pkt_getuint32(pktin);
4161 struct ssh_channel *c;
4162
4163 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4164 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4165 c->remoteid = localid;
4166 c->type = CHAN_SOCKDATA;
4167 c->v.v1.throttling = 0;
4168 pfd_confirm(c->u.pfd.s);
4169 }
4170
4171 if (c && c->closes) {
4172 /*
4173 * We have a pending close on this channel,
4174 * which we decided on before the server acked
4175 * the channel open. So now we know the
4176 * remoteid, we can close it again.
4177 */
4178 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4179 PKT_INT, c->remoteid, PKT_END);
4180 }
4181}
4182
4183static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4184{
4185 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4186 struct ssh_channel *c;
4187
4188 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4189 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4190 logevent("Forwarded connection refused by server");
4191 pfd_close(c->u.pfd.s);
4192 del234(ssh->channels, c);
4193 sfree(c);
4194 }
4195}
4196
4197static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4198{
4199 /* Remote side closes a channel. */
4200 unsigned i = ssh_pkt_getuint32(pktin);
4201 struct ssh_channel *c;
4202 c = find234(ssh->channels, &i, ssh_channelfind);
4203 if (c && ((int)c->remoteid) != -1) {
4204 int closetype;
4205 closetype =
4206 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4207
4208 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4209 logevent("Forwarded X11 connection terminated");
4210 assert(c->u.x11.s != NULL);
4211 x11_close(c->u.x11.s);
4212 c->u.x11.s = NULL;
4213 }
4214 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4215 logevent("Forwarded port closed");
4216 assert(c->u.pfd.s != NULL);
4217 pfd_close(c->u.pfd.s);
4218 c->u.pfd.s = NULL;
4219 }
4220
4221 c->closes |= (closetype << 2); /* seen this message */
4222 if (!(c->closes & closetype)) {
4223 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4224 PKT_END);
4225 c->closes |= closetype; /* sent it too */
4226 }
4227
4228 if (c->closes == 15) {
4229 del234(ssh->channels, c);
4230 sfree(c);
4231 }
4232 } else {
4233 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4234 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4235 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4236 i));
4237 }
4238}
4239
4240static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4241{
4242 /* Data sent down one of our channels. */
4243 int i = ssh_pkt_getuint32(pktin);
4244 char *p;
aa63ab7e 4245 unsigned int len;
51df0ab5 4246 struct ssh_channel *c;
4247
4248 ssh_pkt_getstring(pktin, &p, &len);
4249
4250 c = find234(ssh->channels, &i, ssh_channelfind);
4251 if (c) {
4252 int bufsize = 0;
4253 switch (c->type) {
4254 case CHAN_X11:
4255 bufsize = x11_send(c->u.x11.s, p, len);
4256 break;
4257 case CHAN_SOCKDATA:
4258 bufsize = pfd_send(c->u.pfd.s, p, len);
4259 break;
4260 case CHAN_AGENT:
4261 /* Data for an agent message. Buffer it. */
4262 while (len > 0) {
4263 if (c->u.a.lensofar < 4) {
aa63ab7e 4264 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4265 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4266 l);
4267 p += l;
4268 len -= l;
4269 c->u.a.lensofar += l;
4270 }
4271 if (c->u.a.lensofar == 4) {
4272 c->u.a.totallen =
4273 4 + GET_32BIT(c->u.a.msglen);
4274 c->u.a.message = snewn(c->u.a.totallen,
4275 unsigned char);
4276 memcpy(c->u.a.message, c->u.a.msglen, 4);
4277 }
4278 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4279 unsigned int l =
51df0ab5 4280 min(c->u.a.totallen - c->u.a.lensofar,
4281 len);
4282 memcpy(c->u.a.message + c->u.a.lensofar, p,
4283 l);
4284 p += l;
4285 len -= l;
4286 c->u.a.lensofar += l;
4287 }
4288 if (c->u.a.lensofar == c->u.a.totallen) {
4289 void *reply;
4290 int replylen;
4291 if (agent_query(c->u.a.message,
4292 c->u.a.totallen,
4293 &reply, &replylen,
4294 ssh_agentf_callback, c))
4295 ssh_agentf_callback(c, reply, replylen);
4296 sfree(c->u.a.message);
4297 c->u.a.lensofar = 0;
4298 }
4299 }
4300 bufsize = 0; /* agent channels never back up */
4301 break;
4302 }
4303 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4304 c->v.v1.throttling = 1;
4305 ssh1_throttle(ssh, +1);
4306 }
4307 }
4308}
4309
4310static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4311{
4312 char buf[100];
4313 ssh->exitcode = ssh_pkt_getuint32(pktin);
4314 sprintf(buf, "Server sent command exit status %d",
4315 ssh->exitcode);
4316 logevent(buf);
4317 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4318 /*
4319 * In case `helpful' firewalls or proxies tack
4320 * extra human-readable text on the end of the
4321 * session which we might mistake for another
4322 * encrypted packet, we close the session once
4323 * we've sent EXIT_CONFIRMATION.
4324 */
4325 ssh_closing((Plug)ssh, NULL, 0, 0);
4326}
4327
b09eaa88 4328static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4329 struct Packet *pktin)
32874aea 4330{
b09eaa88 4331 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4332
51df0ab5 4333 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4334 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4335 ssh1_smsg_stdout_stderr_data;
4336
4337 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4338 ssh1_msg_channel_open_confirmation;
4339 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4340 ssh1_msg_channel_open_failure;
4341 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4342 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4343 ssh1_msg_channel_close;
4344 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4345 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4346
86916870 4347 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4348 logevent("Requesting agent forwarding");
51470298 4349 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4350 do {
4351 crReturnV;
ff3187f6 4352 } while (!pktin);
4353 if (pktin->type != SSH1_SMSG_SUCCESS
4354 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4355 bombout(("Protocol confusion"));
7ffdbc1a 4356 crStopV;
ff3187f6 4357 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4358 logevent("Agent forwarding refused");
4359 } else {
4360 logevent("Agent forwarding enabled");
51470298 4361 ssh->agentfwd_enabled = TRUE;
51df0ab5 4362 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4363 }
dacbd0e8 4364 }
4365
86916870 4366 if (ssh->cfg.x11_forward) {
32874aea 4367 char proto[20], data[64];
4368 logevent("Requesting X11 forwarding");
302121de 4369 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4370 data, sizeof(data), ssh->cfg.x11_auth);
4371 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 4372 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4373 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4374 PKT_STR, proto, PKT_STR, data,
86916870 4375 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4376 PKT_END);
32874aea 4377 } else {
51470298 4378 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4379 PKT_STR, proto, PKT_STR, data, PKT_END);
4380 }
4381 do {
4382 crReturnV;
ff3187f6 4383 } while (!pktin);
4384 if (pktin->type != SSH1_SMSG_SUCCESS
4385 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4386 bombout(("Protocol confusion"));
7ffdbc1a 4387 crStopV;
ff3187f6 4388 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4389 logevent("X11 forwarding refused");
4390 } else {
4391 logevent("X11 forwarding enabled");
51470298 4392 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4393 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4394 }
4395 }
4396
06fadff5 4397 ssh_setup_portfwd(ssh, &ssh->cfg);
4398 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4399
86916870 4400 if (!ssh->cfg.nopty) {
a5dd8467 4401 /* Unpick the terminal-speed string. */
4402 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4403 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4404 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4405 /* Send the pty request. */
51470298 4406 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4407 PKT_STR, ssh->cfg.termtype,
51470298 4408 PKT_INT, ssh->term_height,
4409 PKT_INT, ssh->term_width,
a5dd8467 4410 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4411 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4412 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4413 PKT_CHAR, 0, PKT_END);
51470298 4414 ssh->state = SSH_STATE_INTERMED;
32874aea 4415 do {
4416 crReturnV;
ff3187f6 4417 } while (!pktin);
4418 if (pktin->type != SSH1_SMSG_SUCCESS
4419 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4420 bombout(("Protocol confusion"));
7ffdbc1a 4421 crStopV;
ff3187f6 4422 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4423 c_write_str(ssh, "Server refused to allocate pty\r\n");
4424 ssh->editing = ssh->echoing = 1;
32874aea 4425 }
a5dd8467 4426 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4427 ssh->ospeed, ssh->ispeed);
0965bee0 4428 } else {
51470298 4429 ssh->editing = ssh->echoing = 1;
374330e2 4430 }
4431
86916870 4432 if (ssh->cfg.compression) {
51470298 4433 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4434 do {
4435 crReturnV;
ff3187f6 4436 } while (!pktin);
4437 if (pktin->type != SSH1_SMSG_SUCCESS
4438 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4439 bombout(("Protocol confusion"));
7ffdbc1a 4440 crStopV;
ff3187f6 4441 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4442 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4443 }
4ba9b64b 4444 logevent("Started compression");
51470298 4445 ssh->v1_compressing = TRUE;
5366aed8 4446 ssh->cs_comp_ctx = zlib_compress_init();
4447 logevent("Initialised zlib (RFC1950) compression");
4448 ssh->sc_comp_ctx = zlib_decompress_init();
4449 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4450 }
4451
fd5e5847 4452 /*
4453 * Start the shell or command.
4454 *
4455 * Special case: if the first-choice command is an SSH2
4456 * subsystem (hence not usable here) and the second choice
4457 * exists, we fall straight back to that.
4458 */
4459 {
86916870 4460 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 4461
86916870 4462 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4463 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4464 ssh->fallback_cmd = TRUE;
fd5e5847 4465 }
4466 if (*cmd)
51470298 4467 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4468 else
51470298 4469 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4470 logevent("Started session");
4471 }
374330e2 4472
51470298 4473 ssh->state = SSH_STATE_SESSION;
4474 if (ssh->size_needed)
4475 ssh_size(ssh, ssh->term_width, ssh->term_height);
4476 if (ssh->eof_needed)
4477 ssh_special(ssh, TS_EOF);
374330e2 4478
b9d7bcad 4479 if (ssh->ldisc)
4480 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4481 ssh->send_ok = 1;
4482 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4483 while (1) {
d74d141c 4484
51df0ab5 4485 /*
4486 * By this point, most incoming packets are already being
4487 * handled by the dispatch table, and we need only pay
4488 * attention to the unusual ones.
4489 */
0357890f 4490
51df0ab5 4491 crReturnV;
4492 if (pktin) {
4493 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4494 /* may be from EXEC_SHELL on some servers */
ff3187f6 4495 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4496 /* may be from EXEC_SHELL on some servers
374330e2 4497 * if no pty is available or in other odd cases. Ignore */
374330e2 4498 } else {
ff3187f6 4499 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4500 crStopV;
374330e2 4501 }
4502 } else {
8df7a775 4503 while (inlen > 0) {
4504 int len = min(inlen, 512);
9a10ecf4 4505 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4506 PKT_INT, len, PKT_DATA, in, len,
4507 PKTT_OTHER, PKT_END);
8df7a775 4508 in += len;
4509 inlen -= len;
4510 }
374330e2 4511 }
4512 }
4513
4514 crFinishV;
4515}
4516
4517/*
b09eaa88 4518 * Handle the top-level SSH2 protocol.
4519 */
4520static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4521{
4522 char *buf, *msg;
4523 int msglen;
4524
4525 ssh_pkt_getstring(pktin, &msg, &msglen);
4526 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4527 logevent(buf);
4528 sfree(buf);
4529}
4530
4531static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4532{
4533 /* log reason code in disconnect message */
4534 char *msg;
4535 int msglen;
4536
4537 ssh_pkt_getstring(pktin, &msg, &msglen);
4538 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4539}
4540
4541void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4542{
4543 /* Do nothing, because we're ignoring it! Duhh. */
4544}
4545
4546static void ssh1_protocol_setup(Ssh ssh)
4547{
4548 int i;
4549
4550 /*
4551 * Most messages are handled by the coroutines.
4552 */
4553 for (i = 0; i < 256; i++)
4554 ssh->packet_dispatch[i] = NULL;
4555
4556 /*
4557 * These special message types we install handlers for.
4558 */
4559 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4560 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4561 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4562}
4563
4564static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4565 struct Packet *pktin)
4566{
4567 if (ssh->state == SSH_STATE_CLOSED)
4568 return;
4569
4570 if (pktin && ssh->packet_dispatch[pktin->type]) {
4571 ssh->packet_dispatch[pktin->type](ssh, pktin);
4572 return;
4573 }
4574
4575 if (!ssh->protocol_initial_phase_done) {
4576 if (do_ssh1_login(ssh, in, inlen, pktin))
4577 ssh->protocol_initial_phase_done = TRUE;
4578 else
4579 return;
4580 }
4581
4582 do_ssh1_connection(ssh, in, inlen, pktin);
4583}
4584
4585/*
e5574168 4586 * Utility routine for decoding comma-separated strings in KEXINIT.
4587 */
32874aea 4588static int in_commasep_string(char *needle, char *haystack, int haylen)
4589{
57356d63 4590 int needlen;
4591 if (!needle || !haystack) /* protect against null pointers */
4592 return 0;
4593 needlen = strlen(needle);
e5574168 4594 while (1) {
32874aea 4595 /*
4596 * Is it at the start of the string?
4597 */
4598 if (haylen >= needlen && /* haystack is long enough */
4599 !memcmp(needle, haystack, needlen) && /* initial match */
4600 (haylen == needlen || haystack[needlen] == ',')
4601 /* either , or EOS follows */
4602 )
4603 return 1;
4604 /*
4605 * If not, search for the next comma and resume after that.
4606 * If no comma found, terminate.
4607 */
4608 while (haylen > 0 && *haystack != ',')
4609 haylen--, haystack++;
4610 if (haylen == 0)
4611 return 0;
4612 haylen--, haystack++; /* skip over comma itself */
e5574168 4613 }
4614}
4615
4616/*
d39f364a 4617 * SSH2 key creation method.
4618 */
d8baa528 4619static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4620 unsigned char *sessid, char chr,
4621 unsigned char *keyspace)
32874aea 4622{
d39f364a 4623 SHA_State s;
4624 /* First 20 bytes. */
4625 SHA_Init(&s);
51470298 4626 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4627 sha_mpint(&s, K);
d39f364a 4628 SHA_Bytes(&s, H, 20);
4629 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4630 SHA_Bytes(&s, sessid, 20);
d39f364a 4631 SHA_Final(&s, keyspace);
4632 /* Next 20 bytes. */
4633 SHA_Init(&s);
51470298 4634 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4635 sha_mpint(&s, K);
d39f364a 4636 SHA_Bytes(&s, H, 20);
4637 SHA_Bytes(&s, keyspace, 20);
32874aea 4638 SHA_Final(&s, keyspace + 20);
d39f364a 4639}
4640
4641/*
7cca0d81 4642 * Handle the SSH2 transport layer.
e5574168 4643 */
ff3187f6 4644static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4645 struct Packet *pktin)
e5574168 4646{
51470298 4647 struct do_ssh2_transport_state {
4648 int nbits, pbits, warn;
4649 Bignum p, g, e, f, K;
4650 int kex_init_value, kex_reply_value;
4651 const struct ssh_mac **maclist;
4652 int nmacs;
4653 const struct ssh2_cipher *cscipher_tobe;
4654 const struct ssh2_cipher *sccipher_tobe;
4655 const struct ssh_mac *csmac_tobe;
4656 const struct ssh_mac *scmac_tobe;
4657 const struct ssh_compress *cscomp_tobe;
4658 const struct ssh_compress *sccomp_tobe;
4659 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4660 int hostkeylen, siglen;
4661 void *hkey; /* actual host key */
4662 unsigned char exchange_hash[20];
83e7d008 4663 int n_preferred_kex;
4664 const struct ssh_kex *preferred_kex[KEX_MAX];
51470298 4665 int n_preferred_ciphers;
4666 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4667 const struct ssh_compress *preferred_comp;
e13bba36 4668 int got_session_id, activated_authconn;
ff3187f6 4669 struct Packet *pktout;
51470298 4670 };
4671 crState(do_ssh2_transport_state);
4672
4673 crBegin(ssh->do_ssh2_transport_crstate);
4674
4675 s->cscipher_tobe = s->sccipher_tobe = NULL;
4676 s->csmac_tobe = s->scmac_tobe = NULL;
4677 s->cscomp_tobe = s->sccomp_tobe = NULL;
4678
e13bba36 4679 s->got_session_id = s->activated_authconn = FALSE;
e5574168 4680
e13bba36 4681 /*
4682 * Be prepared to work around the buggy MAC problem.
4683 */
4684 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4685 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4686 else
4687 s->maclist = macs, s->nmacs = lenof(macs);
4688
4689 begin_key_exchange:
149d2abc 4690 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
51470298 4691 {
e13bba36 4692 int i, j, commalist_started;
4693
51470298 4694 /*
83e7d008 4695 * Set up the preferred key exchange. (NULL => warn below here)
4696 */
4697 s->n_preferred_kex = 0;
4698 for (i = 0; i < KEX_MAX; i++) {
4699 switch (ssh->cfg.ssh_kexlist[i]) {
4700 case KEX_DHGEX:
4701 s->preferred_kex[s->n_preferred_kex++] =
4702 &ssh_diffiehellman_gex;
4703 break;
4704 case KEX_DHGROUP14:
4705 s->preferred_kex[s->n_preferred_kex++] =
4706 &ssh_diffiehellman_group14;
4707 break;
4708 case KEX_DHGROUP1:
4709 s->preferred_kex[s->n_preferred_kex++] =
4710 &ssh_diffiehellman_group1;
4711 break;
4712 case CIPHER_WARN:
4713 /* Flag for later. Don't bother if it's the last in
4714 * the list. */
4715 if (i < KEX_MAX - 1) {
4716 s->preferred_kex[s->n_preferred_kex++] = NULL;
4717 }
4718 break;
4719 }
4720 }
83e7d008 4721
83e7d008 4722 /*
51470298 4723 * Set up the preferred ciphers. (NULL => warn below here)
4724 */
4725 s->n_preferred_ciphers = 0;
4726 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4727 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4728 case CIPHER_BLOWFISH:
4729 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4730 break;
4731 case CIPHER_DES:
86916870 4732 if (ssh->cfg.ssh2_des_cbc) {
51470298 4733 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4734 }
4735 break;
4736 case CIPHER_3DES:
4737 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4738 break;
4739 case CIPHER_AES:
4740 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4741 break;
4742 case CIPHER_WARN:
4743 /* Flag for later. Don't bother if it's the last in
4744 * the list. */
4745 if (i < CIPHER_MAX - 1) {
4746 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4747 }
4748 break;
ca20bfcf 4749 }
ca20bfcf 4750 }
7591b9ff 4751
e13bba36 4752 /*
4753 * Set up preferred compression.
4754 */
4755 if (ssh->cfg.compression)
4756 s->preferred_comp = &ssh_zlib;
4757 else
4758 s->preferred_comp = &ssh_comp_none;
51470298 4759
4760 /*
590f6a5f 4761 * Enable queueing of outgoing auth- or connection-layer
4762 * packets while we are in the middle of a key exchange.
4763 */
4764 ssh->queueing = TRUE;
4765
4766 /*
9442dd57 4767 * Flag that KEX is in progress.
4768 */
4769 ssh->kex_in_progress = TRUE;
4770
4771 /*
51470298 4772 * Construct and send our key exchange packet.
4773 */
ff3187f6 4774 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4775 for (i = 0; i < 16; i++)
ff3187f6 4776 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4777 /* List key exchange algorithms. */
ff3187f6 4778 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4779 commalist_started = 0;
4780 for (i = 0; i < s->n_preferred_kex; i++) {
4781 const struct ssh_kex *k = s->preferred_kex[i];
4782 if (!k) continue; /* warning flag */
4783 if (commalist_started)
ff3187f6 4784 ssh2_pkt_addstring_str(s->pktout, ",");
83e7d008 4785 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4786 commalist_started = 1;
32874aea 4787 }
51470298 4788 /* List server host key algorithms. */
ff3187f6 4789 ssh2_pkt_addstring_start(s->pktout);
51470298 4790 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4791 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4792 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4793 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4794 }
51470298 4795 /* List client->server encryption algorithms. */
ff3187f6 4796 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4797 commalist_started = 0;
51470298 4798 for (i = 0; i < s->n_preferred_ciphers; i++) {
4799 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4800 if (!c) continue; /* warning flag */
4801 for (j = 0; j < c->nciphers; j++) {
83e7d008 4802 if (commalist_started)
ff3187f6 4803 ssh2_pkt_addstring_str(s->pktout, ",");
4804 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4805 commalist_started = 1;
51470298 4806 }
4807 }
4808 /* List server->client encryption algorithms. */
ff3187f6 4809 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4810 commalist_started = 0;
51470298 4811 for (i = 0; i < s->n_preferred_ciphers; i++) {
4812 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4813 if (!c) continue; /* warning flag */
4814 for (j = 0; j < c->nciphers; j++) {
83e7d008 4815 if (commalist_started)
ff3187f6 4816 ssh2_pkt_addstring_str(s->pktout, ",");
4817 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4818 commalist_started = 1;
51470298 4819 }
4820 }
4821 /* List client->server MAC algorithms. */
ff3187f6 4822 ssh2_pkt_addstring_start(s->pktout);
51470298 4823 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4824 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4825 if (i < s->nmacs - 1)
ff3187f6 4826 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4827 }
4828 /* List server->client MAC algorithms. */
ff3187f6 4829 ssh2_pkt_addstring_start(s->pktout);
51470298 4830 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4831 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4832 if (i < s->nmacs - 1)
ff3187f6 4833 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4834 }
4835 /* List client->server compression algorithms. */
ff3187f6 4836 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4837 assert(lenof(compressions) > 1);
ff3187f6 4838 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4839 for (i = 0; i < lenof(compressions); i++) {
4840 const struct ssh_compress *c = compressions[i];
4841 if (c != s->preferred_comp) {
ff3187f6 4842 ssh2_pkt_addstring_str(s->pktout, ",");
4843 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4844 }
51470298 4845 }
4846 /* List server->client compression algorithms. */
ff3187f6 4847 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4848 assert(lenof(compressions) > 1);
ff3187f6 4849 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4850 for (i = 0; i < lenof(compressions); i++) {
4851 const struct ssh_compress *c = compressions[i];
4852 if (c != s->preferred_comp) {
ff3187f6 4853 ssh2_pkt_addstring_str(s->pktout, ",");
4854 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4855 }
51470298 4856 }
4857 /* List client->server languages. Empty list. */
ff3187f6 4858 ssh2_pkt_addstring_start(s->pktout);
51470298 4859 /* List server->client languages. Empty list. */
ff3187f6 4860 ssh2_pkt_addstring_start(s->pktout);
51470298 4861 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4862 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4863 /* Reserved. */
ff3187f6 4864 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4865 }
0db56f73 4866
51470298 4867 ssh->exhash = ssh->exhashbase;
ff3187f6 4868 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4869
590f6a5f 4870 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4871
ff3187f6 4872 if (!pktin)
4873 crWaitUntil(pktin);
4874 if (pktin->length > 5)
4875 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4876
4877 /*
4878 * Now examine the other side's KEXINIT to see what we're up
4879 * to.
4880 */
51470298 4881 {
4882 char *str;
4883 int i, j, len;
4884
ff3187f6 4885 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4886 bombout(("expected key exchange packet from server"));
7ffdbc1a 4887 crStop(0);
32874aea 4888 }
51470298 4889 ssh->kex = NULL;
4890 ssh->hostkey = NULL;
4891 s->cscipher_tobe = NULL;
4892 s->sccipher_tobe = NULL;
4893 s->csmac_tobe = NULL;
4894 s->scmac_tobe = NULL;
4895 s->cscomp_tobe = NULL;
4896 s->sccomp_tobe = NULL;
ff3187f6 4897 pktin->savedpos += 16; /* skip garbage cookie */
4898 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
83e7d008 4899 s->warn = 0;
4900 for (i = 0; i < s->n_preferred_kex; i++) {
4901 const struct ssh_kex *k = s->preferred_kex[i];
4902 if (!k) {
4903 s->warn = 1;
4904 } else if (in_commasep_string(k->name, str, len)) {
4905 ssh->kex = k;
4906 }
4907 if (ssh->kex) {
bb348ab1 4908 if (s->warn) {
4909 sk_set_frozen(ssh->s, 1);
83e7d008 4910 askalg(ssh->frontend, "key-exchange algorithm",
4911 ssh->kex->name);
bb348ab1 4912 sk_set_frozen(ssh->s, 0);
4913 }
51470298 4914 break;
4915 }
32874aea 4916 }
83e7d008 4917 if (!ssh->kex) {
4918 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4919 str ? str : "(null)"));
4920 crStop(0);
4921 }
ff3187f6 4922 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4923 for (i = 0; i < lenof(hostkey_algs); i++) {
4924 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4925 ssh->hostkey = hostkey_algs[i];
4926 break;
4927 }
4928 }
ff3187f6 4929 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4930 s->warn = 0;
4931 for (i = 0; i < s->n_preferred_ciphers; i++) {
4932 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4933 if (!c) {
4934 s->warn = 1;
4935 } else {
4936 for (j = 0; j < c->nciphers; j++) {
4937 if (in_commasep_string(c->list[j]->name, str, len)) {
4938 s->cscipher_tobe = c->list[j];
4939 break;
4940 }
ca20bfcf 4941 }
32874aea 4942 }
51470298 4943 if (s->cscipher_tobe) {
bb348ab1 4944 if (s->warn) {
4945 sk_set_frozen(ssh->s, 1);
83e7d008 4946 askalg(ssh->frontend, "client-to-server cipher",
4947 s->cscipher_tobe->name);
bb348ab1 4948 sk_set_frozen(ssh->s, 0);
4949 }
51470298 4950 break;
4951 }
32874aea 4952 }
51470298 4953 if (!s->cscipher_tobe) {
6b5cf8b4 4954 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4955 str ? str : "(null)"));
7ffdbc1a 4956 crStop(0);
ca20bfcf 4957 }
0ef8f407 4958
ff3187f6 4959 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4960 s->warn = 0;
4961 for (i = 0; i < s->n_preferred_ciphers; i++) {
4962 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4963 if (!c) {
4964 s->warn = 1;
4965 } else {
4966 for (j = 0; j < c->nciphers; j++) {
4967 if (in_commasep_string(c->list[j]->name, str, len)) {
4968 s->sccipher_tobe = c->list[j];
4969 break;
4970 }
ca20bfcf 4971 }
32874aea 4972 }
51470298 4973 if (s->sccipher_tobe) {
bb348ab1 4974 if (s->warn) {
4975 sk_set_frozen(ssh->s, 1);
83e7d008 4976 askalg(ssh->frontend, "server-to-client cipher",
4977 s->sccipher_tobe->name);
bb348ab1 4978 sk_set_frozen(ssh->s, 0);
4979 }
51470298 4980 break;
4981 }
32874aea 4982 }
51470298 4983 if (!s->sccipher_tobe) {
6b5cf8b4 4984 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4985 str ? str : "(null)"));
7ffdbc1a 4986 crStop(0);
ca20bfcf 4987 }
0ef8f407 4988
ff3187f6 4989 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 4990 for (i = 0; i < s->nmacs; i++) {
4991 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4992 s->csmac_tobe = s->maclist[i];
4993 break;
4994 }
32874aea 4995 }
ff3187f6 4996 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 4997 for (i = 0; i < s->nmacs; i++) {
4998 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4999 s->scmac_tobe = s->maclist[i];
5000 break;
5001 }
32874aea 5002 }
ff3187f6 5003 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5004 for (i = 0; i < lenof(compressions) + 1; i++) {
5005 const struct ssh_compress *c =
5006 i == 0 ? s->preferred_comp : compressions[i - 1];
5007 if (in_commasep_string(c->name, str, len)) {
5008 s->cscomp_tobe = c;
5009 break;
5010 }
32874aea 5011 }
ff3187f6 5012 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5013 for (i = 0; i < lenof(compressions) + 1; i++) {
5014 const struct ssh_compress *c =
5015 i == 0 ? s->preferred_comp : compressions[i - 1];
5016 if (in_commasep_string(c->name, str, len)) {
5017 s->sccomp_tobe = c;
5018 break;
5019 }
32874aea 5020 }
e5574168 5021 }
e5574168 5022
5023 /*
7bd5a860 5024 * Work out the number of bits of key we will need from the key
5025 * exchange. We start with the maximum key length of either
5026 * cipher...
5027 */
5028 {
32874aea 5029 int csbits, scbits;
7bd5a860 5030
51470298 5031 csbits = s->cscipher_tobe->keylen;
5032 scbits = s->sccipher_tobe->keylen;
5033 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 5034 }
5035 /* The keys only have 160-bit entropy, since they're based on
5036 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 5037 if (s->nbits > 160)
5038 s->nbits = 160;
7bd5a860 5039
5040 /*
a92dd380 5041 * If we're doing Diffie-Hellman group exchange, start by
5042 * requesting a group.
e5574168 5043 */
d1aaf71d 5044 if (!ssh->kex->pdata) {
32874aea 5045 logevent("Doing Diffie-Hellman group exchange");
51470298 5046 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 5047 /*
5048 * Work out how big a DH group we will need to allow that
5049 * much data.
7bd5a860 5050 */
51470298 5051 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 5052 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5053 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 5054 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 5055
ff3187f6 5056 crWaitUntil(pktin);
5057 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 5058 bombout(("expected key exchange group packet from server"));
7ffdbc1a 5059 crStop(0);
32874aea 5060 }
ff3187f6 5061 s->p = ssh2_pkt_getmp(pktin);
5062 s->g = ssh2_pkt_getmp(pktin);
5063 if (!s->p || !s->g) {
5064 bombout(("unable to read mp-ints from incoming group packet"));
5065 crStop(0);
5066 }
d1aaf71d 5067 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5068 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5069 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5070 } else {
d1aaf71d 5071 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5072 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5073 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5074 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5075 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5076 ssh->kex->groupname);
8d5de777 5077 }
e5574168 5078
a92dd380 5079 logevent("Doing Diffie-Hellman key exchange");
e5574168 5080 /*
a92dd380 5081 * Now generate and send e for Diffie-Hellman.
e5574168 5082 */
27cd7fc2 5083 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5084 s->pktout = ssh2_pkt_init(s->kex_init_value);
5085 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5086 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5087
ff3187f6 5088 crWaitUntil(pktin);
5089 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5090 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5091 crStop(0);
7cca0d81 5092 }
ff3187f6 5093 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5094 s->f = ssh2_pkt_getmp(pktin);
5095 if (!s->f) {
5096 bombout(("unable to parse key exchange reply packet"));
5097 crStop(0);
5098 }
5099 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5100
27cd7fc2 5101 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5102
51470298 5103 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5104 if (ssh->kex == &ssh_diffiehellman_gex) {
5105 sha_uint32(&ssh->exhash, s->pbits);
5106 sha_mpint(&ssh->exhash, s->p);
5107 sha_mpint(&ssh->exhash, s->g);
a92dd380 5108 }
51470298 5109 sha_mpint(&ssh->exhash, s->e);
5110 sha_mpint(&ssh->exhash, s->f);
5111 sha_mpint(&ssh->exhash, s->K);
5112 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 5113
27cd7fc2 5114 dh_cleanup(ssh->kex_ctx);
fabd1805 5115 ssh->kex_ctx = NULL;
3709bfe9 5116
7cca0d81 5117#if 0
765c4200 5118 debug(("Exchange hash is:\n"));
51470298 5119 dmemdump(s->exchange_hash, 20);
7cca0d81 5120#endif
5121
51470298 5122 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5123 if (!s->hkey ||
5124 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 5125 (char *)s->exchange_hash, 20)) {
6b5cf8b4 5126 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5127 crStop(0);
8d5de777 5128 }
e5574168 5129
5130 /*
7cca0d81 5131 * Authenticate remote host: verify host key. (We've already
5132 * checked the signature of the exchange hash.)
e5574168 5133 */
51470298 5134 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5135 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
bb348ab1 5136 sk_set_frozen(ssh->s, 1);
a8327734 5137 verify_ssh_host_key(ssh->frontend,
5138 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 5139 s->keystr, s->fingerprint);
bb348ab1 5140 sk_set_frozen(ssh->s, 0);
e13bba36 5141 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5142 logevent("Host key fingerprint is:");
51470298 5143 logevent(s->fingerprint);
5e0d7cb8 5144 }
51470298 5145 sfree(s->fingerprint);
5146 sfree(s->keystr);
5147 ssh->hostkey->freekey(s->hkey);
d39f364a 5148
5149 /*
9442dd57 5150 * The exchange hash from the very first key exchange is also
5151 * the session id, used in session key construction and
5152 * authentication.
5153 */
e13bba36 5154 if (!s->got_session_id) {
9442dd57 5155 memcpy(ssh->v2_session_id, s->exchange_hash,
5156 sizeof(s->exchange_hash));
e13bba36 5157 s->got_session_id = TRUE;
5158 }
9442dd57 5159
5160 /*
7cca0d81 5161 * Send SSH2_MSG_NEWKEYS.
d39f364a 5162 */
ff3187f6 5163 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5164 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5165 ssh->outgoing_data_size = 0; /* start counting from here */
5166
5167 /*
5168 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5169 * client-to-server session keys.
9442dd57 5170 */
5171 if (ssh->cs_cipher_ctx)
5172 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5173 ssh->cscipher = s->cscipher_tobe;
5174 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5175
5176 if (ssh->cs_mac_ctx)
5177 ssh->csmac->free_context(ssh->cs_mac_ctx);
5178 ssh->csmac = s->csmac_tobe;
5179 ssh->cs_mac_ctx = ssh->csmac->make_context();
5180
5181 if (ssh->cs_comp_ctx)
5182 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5183 ssh->cscomp = s->cscomp_tobe;
5184 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5185
5186 /*
5187 * Set IVs on client-to-server keys. Here we use the exchange
5188 * hash from the _first_ key exchange.
5189 */
5190 {
5191 unsigned char keyspace[40];
5192 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5193 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5194 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5195 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5196 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5197 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5198 }
5199
5200 logeventf(ssh, "Initialised %.200s client->server encryption",
5201 ssh->cscipher->text_name);
5202 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5203 ssh->csmac->text_name);
5204 if (ssh->cscomp->text_name)
5205 logeventf(ssh, "Initialised %s compression",
5206 ssh->cscomp->text_name);
590f6a5f 5207
5208 /*
5209 * Now our end of the key exchange is complete, we can send all
5210 * our queued higher-layer packets.
5211 */
5212 ssh->queueing = FALSE;
5213 ssh2_pkt_queuesend(ssh);
d39f364a 5214
5215 /*
8406eaf9 5216 * Expect SSH2_MSG_NEWKEYS from server.
5217 */
ff3187f6 5218 crWaitUntil(pktin);
5219 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5220 bombout(("expected new-keys packet from server"));
7ffdbc1a 5221 crStop(0);
8406eaf9 5222 }
9442dd57 5223 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5224
5225 /*
9442dd57 5226 * We've seen server NEWKEYS, so create and initialise
5227 * server-to-client session keys.
d39f364a 5228 */
371e569c 5229 if (ssh->sc_cipher_ctx)
5230 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5231 ssh->sccipher = s->sccipher_tobe;
371e569c 5232 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5233
e0e1a00d 5234 if (ssh->sc_mac_ctx)
5235 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5236 ssh->scmac = s->scmac_tobe;
e0e1a00d 5237 ssh->sc_mac_ctx = ssh->scmac->make_context();
5238
5366aed8 5239 if (ssh->sc_comp_ctx)
5240 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5241 ssh->sccomp = s->sccomp_tobe;
5366aed8 5242 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5243
d39f364a 5244 /*
9442dd57 5245 * Set IVs on server-to-client keys. Here we use the exchange
5246 * hash from the _first_ key exchange.
d39f364a 5247 */
51470298 5248 {
5249 unsigned char keyspace[40];
51470298 5250 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 5251 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 5252 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 5253 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 5254 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 5255 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5256 }
57356d63 5257 logeventf(ssh, "Initialised %.200s server->client encryption",
5258 ssh->sccipher->text_name);
6c135243 5259 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5260 ssh->scmac->text_name);
57356d63 5261 if (ssh->sccomp->text_name)
5262 logeventf(ssh, "Initialised %s decompression",
5263 ssh->sccomp->text_name);
9442dd57 5264
5265 /*
5266 * Free key exchange data.
5267 */
679539d7 5268 freebn(s->f);
679539d7 5269 freebn(s->K);
b3949e7e 5270 if (ssh->kex == &ssh_diffiehellman_gex) {
5271 freebn(s->g);
5272 freebn(s->p);
5273 }
d39f364a 5274
033b4cef 5275 /*
e13bba36 5276 * Key exchange is over. Loop straight back round if we have a
5277 * deferred rekey reason.
5278 */
5279 if (ssh->deferred_rekey_reason) {
5280 logevent(ssh->deferred_rekey_reason);
5281 pktin = NULL;
5282 ssh->deferred_rekey_reason = NULL;
5283 goto begin_key_exchange;
5284 }
5285
5286 /*
5287 * Otherwise, schedule a timer for our next rekey.
9442dd57 5288 */
5289 ssh->kex_in_progress = FALSE;
e6c1536e 5290 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5291 if (ssh->cfg.ssh_rekey_time != 0)
5292 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5293 ssh2_timer, ssh);
e13bba36 5294
9442dd57 5295 /*
0db56f73 5296 * If this is the first key exchange phase, we must pass the
5297 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5298 * wants to see it but because it will need time to initialise
5299 * itself before it sees an actual packet. In subsequent key
5300 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5301 * it would only confuse the layer above.
5302 */
e13bba36 5303 if (s->activated_authconn) {
b09eaa88 5304 crReturn(1);
0db56f73 5305 }
e13bba36 5306 s->activated_authconn = TRUE;
0db56f73 5307
5308 /*
7cca0d81 5309 * Now we're encrypting. Begin returning 1 to the protocol main
5310 * function so that other things can run on top of the
5311 * transport. If we ever see a KEXINIT, we must go back to the
5312 * start.
9442dd57 5313 *
5314 * We _also_ go back to the start if we see pktin==NULL and
5315 * inlen==-1, because this is a special signal meaning
5316 * `initiate client-driven rekey', and `in' contains a message
5317 * giving the reason for the rekey.
033b4cef 5318 */
9442dd57 5319 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5320 (!pktin && inlen == -1))) {
f382c87d 5321 wait_for_rekey:
32874aea 5322 crReturn(1);
e96adf72 5323 }
9442dd57 5324 if (pktin) {
5325 logevent("Server initiated key re-exchange");
5326 } else {
f382c87d 5327 /*
5328 * Special case: if the server bug is set that doesn't
5329 * allow rekeying, we give a different log message and
5330 * continue waiting. (If such a server _initiates_ a rekey,
5331 * we process it anyway!)
5332 */
5333 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5334 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5335 (char *)in);
5336 /* Reset the counters, so that at least this message doesn't
5337 * hit the event log _too_ often. */
5338 ssh->outgoing_data_size = 0;
5339 ssh->incoming_data_size = 0;
5340 if (ssh->cfg.ssh_rekey_time != 0) {
5341 ssh->next_rekey =
5342 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5343 ssh2_timer, ssh);
5344 }
5345 goto wait_for_rekey; /* this is utterly horrid */
5346 } else {
5347 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 5348 }
9442dd57 5349 }
7cca0d81 5350 goto begin_key_exchange;
e5574168 5351
5352 crFinish(1);
5353}
5354
7cca0d81 5355/*
783415f8 5356 * Add data to an SSH2 channel output buffer.
5357 */
32874aea 5358static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5359 int len)
5360{
5471d09a 5361 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5362}
5363
5364/*
5365 * Attempt to send data on an SSH2 channel.
5366 */
5471d09a 5367static int ssh2_try_send(struct ssh_channel *c)
32874aea 5368{
51470298 5369 Ssh ssh = c->ssh;
ff3187f6 5370 struct Packet *pktout;
51470298 5371
5471d09a 5372 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5373 int len;
5374 void *data;
5375 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5376 if ((unsigned)len > c->v.v2.remwindow)
5377 len = c->v.v2.remwindow;
5378 if ((unsigned)len > c->v.v2.remmaxpkt)
5379 len = c->v.v2.remmaxpkt;
ff3187f6 5380 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5381 ssh2_pkt_adduint32(pktout, c->remoteid);
5382 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5383 ssh2_pkt_addstring_start(pktout);
5384 ssh2_pkt_addstring_data(pktout, data, len);
5385 end_log_omission(ssh, pktout);
5386 ssh2_pkt_send(ssh, pktout);
5471d09a 5387 bufchain_consume(&c->v.v2.outbuffer, len);
5388 c->v.v2.remwindow -= len;
5389 }
5390
5391 /*
5392 * After having sent as much data as we can, return the amount
5393 * still buffered.
5394 */
5395 return bufchain_size(&c->v.v2.outbuffer);
5396}
5397
5398/*
5399 * Potentially enlarge the window on an SSH2 channel.
5400 */
5401static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5402{
51470298 5403 Ssh ssh = c->ssh;
5404
6b69f42e 5405 /*
5406 * Never send WINDOW_ADJUST for a channel that the remote side
5407 * already thinks it's closed; there's no point, since it won't
5408 * be sending any more data anyway.
5409 */
5410 if (c->closes != 0)
5411 return;
5412
5471d09a 5413 if (newwin > c->v.v2.locwindow) {
ff3187f6 5414 struct Packet *pktout;
5415
5416 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5417 ssh2_pkt_adduint32(pktout, c->remoteid);
5418 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5419 ssh2_pkt_send(ssh, pktout);
5471d09a 5420 c->v.v2.locwindow = newwin;
783415f8 5421 }
5422}
5423
51df0ab5 5424static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5425{
5426 unsigned i = ssh_pkt_getuint32(pktin);
5427 struct ssh_channel *c;
5428 c = find234(ssh->channels, &i, ssh_channelfind);
5429 if (c && !c->closes)
5430 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5431}
5432
51df0ab5 5433static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5434{
5435 char *data;
aa63ab7e 5436 unsigned int length;
51df0ab5 5437 unsigned i = ssh_pkt_getuint32(pktin);
5438 struct ssh_channel *c;
5439 c = find234(ssh->channels, &i, ssh_channelfind);
5440 if (!c)
5441 return; /* nonexistent channel */
5442 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5443 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5444 return; /* extended but not stderr */
5445 ssh_pkt_getstring(pktin, &data, &length);
5446 if (data) {
5447 int bufsize = 0;
5448 c->v.v2.locwindow -= length;
5449 switch (c->type) {
5450 case CHAN_MAINSESSION:
5451 bufsize =
5452 from_backend(ssh->frontend, pktin->type ==
5453 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5454 data, length);
5455 break;
5456 case CHAN_X11:
5457 bufsize = x11_send(c->u.x11.s, data, length);
5458 break;
5459 case CHAN_SOCKDATA:
5460 bufsize = pfd_send(c->u.pfd.s, data, length);
5461 break;
5462 case CHAN_AGENT:
5463 while (length > 0) {
5464 if (c->u.a.lensofar < 4) {
aa63ab7e 5465 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5466 memcpy(c->u.a.msglen + c->u.a.lensofar,
5467 data, l);
5468 data += l;
5469 length -= l;
5470 c->u.a.lensofar += l;
5471 }
5472 if (c->u.a.lensofar == 4) {
5473 c->u.a.totallen =
5474 4 + GET_32BIT(c->u.a.msglen);
5475 c->u.a.message = snewn(c->u.a.totallen,
5476 unsigned char);
5477 memcpy(c->u.a.message, c->u.a.msglen, 4);
5478 }
5479 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5480 unsigned int l =
51df0ab5 5481 min(c->u.a.totallen - c->u.a.lensofar,
5482 length);
5483 memcpy(c->u.a.message + c->u.a.lensofar,
5484 data, l);
5485 data += l;
5486 length -= l;
5487 c->u.a.lensofar += l;
5488 }
5489 if (c->u.a.lensofar == c->u.a.totallen) {
5490 void *reply;
5491 int replylen;
5492 if (agent_query(c->u.a.message,
5493 c->u.a.totallen,
5494 &reply, &replylen,
5495 ssh_agentf_callback, c))
5496 ssh_agentf_callback(c, reply, replylen);
5497 sfree(c->u.a.message);
5498 c->u.a.lensofar = 0;
5499 }
5500 }
5501 bufsize = 0;
5502 break;
5503 }
5504 /*
5505 * If we are not buffering too much data,
5506 * enlarge the window again at the remote side.
5507 */
5508 if (bufsize < OUR_V2_WINSIZE)
5509 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5510 }
5511}
5512
5513static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5514{
5515 unsigned i = ssh_pkt_getuint32(pktin);
5516 struct ssh_channel *c;
5517
5518 c = find234(ssh->channels, &i, ssh_channelfind);
5519 if (!c)
5520 return; /* nonexistent channel */
5521
5522 if (c->type == CHAN_X11) {
5523 /*
5524 * Remote EOF on an X11 channel means we should
5525 * wrap up and close the channel ourselves.
5526 */
5527 x11_close(c->u.x11.s);
5528 sshfwd_close(c);
5529 } else if (c->type == CHAN_AGENT) {
5530 sshfwd_close(c);
5531 } else if (c->type == CHAN_SOCKDATA) {
5532 pfd_close(c->u.pfd.s);
5533 sshfwd_close(c);
5534 }
5535}
5536
5537static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5538{
5539 unsigned i = ssh_pkt_getuint32(pktin);
5540 struct ssh_channel *c;
5541 struct Packet *pktout;
5542
5543 c = find234(ssh->channels, &i, ssh_channelfind);
5544 if (!c || ((int)c->remoteid) == -1) {
5545 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5546 c ? "half-open" : "nonexistent", i));
5547 return;
5548 }
5549 /* Do pre-close processing on the channel. */
5550 switch (c->type) {
5551 case CHAN_MAINSESSION:
5552 ssh->mainchan = NULL;
5553 update_specials_menu(ssh->frontend);
5554 break;
5555 case CHAN_X11:
5556 if (c->u.x11.s != NULL)
5557 x11_close(c->u.x11.s);
5558 sshfwd_close(c);
5559 break;
5560 case CHAN_AGENT:
5561 sshfwd_close(c);
5562 break;
5563 case CHAN_SOCKDATA:
5564 if (c->u.pfd.s != NULL)
5565 pfd_close(c->u.pfd.s);
5566 sshfwd_close(c);
5567 break;
5568 }
5569 if (c->closes == 0) {
5570 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5571 ssh2_pkt_adduint32(pktout, c->remoteid);
5572 ssh2_pkt_send(ssh, pktout);
5573 }
5574 del234(ssh->channels, c);
5575 bufchain_clear(&c->v.v2.outbuffer);
5576 sfree(c);
5577
5578 /*
5579 * See if that was the last channel left open.
5580 * (This is only our termination condition if we're
5581 * not running in -N mode.)
5582 */
5583 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5584 logevent("All channels closed. Disconnecting");
5585#if 0
5586 /*
5587 * We used to send SSH_MSG_DISCONNECT here,
5588 * because I'd believed that _every_ conforming
5589 * SSH2 connection had to end with a disconnect
5590 * being sent by at least one side; apparently
5591 * I was wrong and it's perfectly OK to
5592 * unceremoniously slam the connection shut
5593 * when you're done, and indeed OpenSSH feels
5594 * this is more polite than sending a
5595 * DISCONNECT. So now we don't.
5596 */
5597 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5598 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5599 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5600 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5601 ssh2_pkt_send_noqueue(ssh, s->pktout);
5602#endif
5603 ssh_closing((Plug)ssh, NULL, 0, 0);
5604 }
5605}
5606
5607static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5608{
5609 unsigned i = ssh_pkt_getuint32(pktin);
5610 struct ssh_channel *c;
5611 struct Packet *pktout;
5612
5613 c = find234(ssh->channels, &i, ssh_channelfind);
5614 if (!c)
5615 return; /* nonexistent channel */
5616 if (c->type != CHAN_SOCKDATA_DORMANT)
5617 return; /* dunno why they're confirming this */
5618 c->remoteid = ssh_pkt_getuint32(pktin);
5619 c->type = CHAN_SOCKDATA;
5620 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5621 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5622 if (c->u.pfd.s)
5623 pfd_confirm(c->u.pfd.s);
5624 if (c->closes) {
5625 /*
5626 * We have a pending close on this channel,
5627 * which we decided on before the server acked
5628 * the channel open. So now we know the
5629 * remoteid, we can close it again.
5630 */
5631 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5632 ssh2_pkt_adduint32(pktout, c->remoteid);
5633 ssh2_pkt_send(ssh, pktout);
5634 }
5635}
5636
5637static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5638{
5639 static const char *const reasons[] = {
5640 "<unknown reason code>",
5641 "Administratively prohibited",
5642 "Connect failed",
5643 "Unknown channel type",
5644 "Resource shortage",
5645 };
5646 unsigned i = ssh_pkt_getuint32(pktin);
5647 unsigned reason_code;
5648 char *reason_string;
5649 int reason_length;
5650 char *message;
5651 struct ssh_channel *c;
5652 c = find234(ssh->channels, &i, ssh_channelfind);
5653 if (!c)
5654 return; /* nonexistent channel */
5655 if (c->type != CHAN_SOCKDATA_DORMANT)
5656 return; /* dunno why they're failing this */
5657
5658 reason_code = ssh_pkt_getuint32(pktin);
5659 if (reason_code >= lenof(reasons))
5660 reason_code = 0; /* ensure reasons[reason_code] in range */
5661 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5662 message = dupprintf("Forwarded connection refused by"
5663 " server: %s [%.*s]", reasons[reason_code],
5664 reason_length, reason_string);
5665 logevent(message);
5666 sfree(message);
5667
5668 pfd_close(c->u.pfd.s);
5669
5670 del234(ssh->channels, c);
5671 sfree(c);
5672}
5673
5674static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5675{
5676 unsigned localid;
5677 char *type;
5678 int typelen, want_reply;
5679 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5680 struct ssh_channel *c;
5681 struct Packet *pktout;
5682
5683 localid = ssh_pkt_getuint32(pktin);
5684 ssh_pkt_getstring(pktin, &type, &typelen);
5685 want_reply = ssh2_pkt_getbool(pktin);
5686
5687 /*
5688 * First, check that the channel exists. Otherwise,
5689 * we can instantly disconnect with a rude message.
5690 */
5691 c = find234(ssh->channels, &localid, ssh_channelfind);
5692 if (!c) {
5693 char buf[80];
5694 sprintf(buf, "Received channel request for nonexistent"
5695 " channel %d", localid);
5696 logevent(buf);
5697 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5698 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5699 ssh2_pkt_addstring(pktout, buf);
5700 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5701 ssh2_pkt_send_noqueue(ssh, pktout);
5702 connection_fatal(ssh->frontend, "%s", buf);
5703 ssh_closing((Plug)ssh, NULL, 0, 0);
5704 return;
5705 }
5706
5707 /*
5708 * Having got the channel number, we now look at
5709 * the request type string to see if it's something
5710 * we recognise.
5711 */
5712 if (c == ssh->mainchan) {
5713 /*
5714 * We recognise "exit-status" and "exit-signal" on
5715 * the primary channel.
5716 */
5717 if (typelen == 11 &&
5718 !memcmp(type, "exit-status", 11)) {
5719
5720 ssh->exitcode = ssh_pkt_getuint32(pktin);
5721 logeventf(ssh, "Server sent command exit status %d",
5722 ssh->exitcode);
5723 reply = SSH2_MSG_CHANNEL_SUCCESS;
5724
5725 } else if (typelen == 11 &&
5726 !memcmp(type, "exit-signal", 11)) {
5727
5728 int is_plausible = TRUE, is_int = FALSE;
5729 char *fmt_sig = "", *fmt_msg = "";
5730 char *msg;
5731 int msglen = 0, core = FALSE;
5732 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5733 * provide an `int' for the signal, despite its
5734 * having been a `string' in the drafts since at
5735 * least 2001. (Fixed in session.c 1.147.) Try to
5736 * infer which we can safely parse it as. */
5737 {
5738 unsigned char *p = pktin->body +
5739 pktin->savedpos;
5740 long len = pktin->length - pktin->savedpos;
5741 unsigned long num = GET_32BIT(p); /* what is it? */
5742 /* If it's 0, it hardly matters; assume string */
5743 if (num == 0) {
5744 is_int = FALSE;
5745 } else {
5746 int maybe_int = FALSE, maybe_str = FALSE;
5747#define CHECK_HYPOTHESIS(offset, result) \
5748 do { \
5749 long q = offset; \
5750 if (q >= 0 && q+4 <= len) { \
5751 q = q + 4 + GET_32BIT(p+q); \
5752 if (q >= 0 && q+4 <= len && \
5753 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5754 result = TRUE; \
5755 } \
5756 } while(0)
5757 CHECK_HYPOTHESIS(4+1, maybe_int);
5758 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5759#undef CHECK_HYPOTHESIS
5760 if (maybe_int && !maybe_str)
5761 is_int = TRUE;
5762 else if (!maybe_int && maybe_str)
5763 is_int = FALSE;
5764 else
5765 /* Crikey. Either or neither. Panic. */
5766 is_plausible = FALSE;
5767 }
5768 }
5769 if (is_plausible) {
5770 if (is_int) {
5771 /* Old non-standard OpenSSH. */
5772 int signum = ssh_pkt_getuint32(pktin);
5773 fmt_sig = dupprintf(" %d", signum);
5774 } else {
5775 /* As per the drafts. */
5776 char *sig;
5777 int siglen;
5778 ssh_pkt_getstring(pktin, &sig, &siglen);
5779 /* Signal name isn't supposed to be blank, but
5780 * let's cope gracefully if it is. */
5781 if (siglen) {
5782 fmt_sig = dupprintf(" \"%.*s\"",
5783 siglen, sig);
5784 }
5785 }
5786 core = ssh2_pkt_getbool(pktin);
5787 ssh_pkt_getstring(pktin, &msg, &msglen);
5788 if (msglen) {
5789 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5790 }
5791 /* ignore lang tag */
5792 } /* else don't attempt to parse */
5793 logeventf(ssh, "Server exited on signal%s%s%s",
5794 fmt_sig, core ? " (core dumped)" : "",
5795 fmt_msg);
5796 if (*fmt_sig) sfree(fmt_sig);
5797 if (*fmt_msg) sfree(fmt_msg);
5798 reply = SSH2_MSG_CHANNEL_SUCCESS;
5799
5800 }
5801 } else {
5802 /*
5803 * This is a channel request we don't know
5804 * about, so we now either ignore the request
5805 * or respond with CHANNEL_FAILURE, depending
5806 * on want_reply.
5807 */
5808 reply = SSH2_MSG_CHANNEL_FAILURE;
5809 }
5810 if (want_reply) {
5811 pktout = ssh2_pkt_init(reply);
5812 ssh2_pkt_adduint32(pktout, c->remoteid);
5813 ssh2_pkt_send(ssh, pktout);
5814 }
5815}
5816
5817static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5818{
5819 char *type;
5820 int typelen, want_reply;
5821 struct Packet *pktout;
5822
5823 ssh_pkt_getstring(pktin, &type, &typelen);
5824 want_reply = ssh2_pkt_getbool(pktin);
5825
5826 /*
5827 * We currently don't support any global requests
5828 * at all, so we either ignore the request or
5829 * respond with REQUEST_FAILURE, depending on
5830 * want_reply.
5831 */
5832 if (want_reply) {
5833 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5834 ssh2_pkt_send(ssh, pktout);
5835 }
5836}
5837
5838static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5839{
5840 char *type;
5841 int typelen;
5842 char *peeraddr;
5843 int peeraddrlen;
5844 int peerport;
5845 char *error = NULL;
5846 struct ssh_channel *c;
5847 unsigned remid, winsize, pktsize;
5848 struct Packet *pktout;
5849
5850 ssh_pkt_getstring(pktin, &type, &typelen);
5851 c = snew(struct ssh_channel);
5852 c->ssh = ssh;
5853
5854 remid = ssh_pkt_getuint32(pktin);
5855 winsize = ssh_pkt_getuint32(pktin);
5856 pktsize = ssh_pkt_getuint32(pktin);
5857
5858 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5859 char *addrstr;
5860
5861 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5862 addrstr = snewn(peeraddrlen+1, char);
5863 memcpy(addrstr, peeraddr, peeraddrlen);
5864 addrstr[peeraddrlen] = '\0';
5865 peerport = ssh_pkt_getuint32(pktin);
5866
5867 logeventf(ssh, "Received X11 connect request from %s:%d",
5868 addrstr, peerport);
5869
5870 if (!ssh->X11_fwd_enabled)
5871 error = "X11 forwarding is not enabled";
5872 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5873 ssh->x11auth, addrstr, peerport,
5874 &ssh->cfg) != NULL) {
5875 error = "Unable to open an X11 connection";
5876 } else {
5877 logevent("Opening X11 forward connection succeeded");
5878 c->type = CHAN_X11;
5879 }
5880
5881 sfree(addrstr);
5882 } else if (typelen == 15 &&
5883 !memcmp(type, "forwarded-tcpip", 15)) {
5884 struct ssh_rportfwd pf, *realpf;
5885 char *dummy;
5886 int dummylen;
5887 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5888 pf.sport = ssh_pkt_getuint32(pktin);
5889 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5890 peerport = ssh_pkt_getuint32(pktin);
5891 realpf = find234(ssh->rportfwds, &pf, NULL);
5892 logeventf(ssh, "Received remote port %d open request "
5893 "from %s:%d", pf.sport, peeraddr, peerport);
5894 if (realpf == NULL) {
5895 error = "Remote port is not recognised";
5896 } else {
5897 const char *e = pfd_newconnect(&c->u.pfd.s,
5898 realpf->dhost,
5899 realpf->dport, c,
05581745 5900 &ssh->cfg,
5901 realpf->pfrec->addressfamily);
51df0ab5 5902 logeventf(ssh, "Attempting to forward remote port to "
5903 "%s:%d", realpf->dhost, realpf->dport);
5904 if (e != NULL) {
5905 logeventf(ssh, "Port open failed: %s", e);
5906 error = "Port open failed";
5907 } else {
5908 logevent("Forwarded port opened successfully");
5909 c->type = CHAN_SOCKDATA;
5910 }
5911 }
5912 } else if (typelen == 22 &&
5913 !memcmp(type, "auth-agent@openssh.com", 3)) {
5914 if (!ssh->agentfwd_enabled)
5915 error = "Agent forwarding is not enabled";
5916 else {
5917 c->type = CHAN_AGENT; /* identify channel type */
5918 c->u.a.lensofar = 0;
5919 }
5920 } else {
5921 error = "Unsupported channel type requested";
5922 }
5923
5924 c->remoteid = remid;
5925 if (error) {
5926 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5927 ssh2_pkt_adduint32(pktout, c->remoteid);
5928 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5929 ssh2_pkt_addstring(pktout, error);
5930 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5931 ssh2_pkt_send(ssh, pktout);
5932 logeventf(ssh, "Rejected channel open: %s", error);
5933 sfree(c);
5934 } else {
5935 c->localid = alloc_channel_id(ssh);
5936 c->closes = 0;
5937 c->v.v2.locwindow = OUR_V2_WINSIZE;
5938 c->v.v2.remwindow = winsize;
5939 c->v.v2.remmaxpkt = pktsize;
5940 bufchain_init(&c->v.v2.outbuffer);
5941 add234(ssh->channels, c);
5942 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5943 ssh2_pkt_adduint32(pktout, c->remoteid);
5944 ssh2_pkt_adduint32(pktout, c->localid);
5945 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5946 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5947 ssh2_pkt_send(ssh, pktout);
5948 }
5949}
5950
783415f8 5951/*
7cca0d81 5952 * Handle the SSH2 userauth and connection layers.
5953 */
ff3187f6 5954static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5955 struct Packet *pktin)
7cca0d81 5956{
51470298 5957 struct do_ssh2_authconn_state {
5958 enum {
5959 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5960 AUTH_PASSWORD,
5961 AUTH_KEYBOARD_INTERACTIVE
5962 } method;
5963 enum {
5964 AUTH_TYPE_NONE,
5965 AUTH_TYPE_PUBLICKEY,
5966 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5967 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5968 AUTH_TYPE_PASSWORD,
5969 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5970 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5971 } type;
5972 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6ac3a551 5973 int tried_pubkey_config, tried_agent;
5974 int kbd_inter_running, kbd_inter_refused;
51470298 5975 int we_are_in;
5976 int num_prompts, curr_prompt, echo;
5977 char username[100];
5978 int got_username;
85fdbe25 5979 char pwprompt[512];
51470298 5980 char password[100];
5981 void *publickey_blob;
5982 int publickey_bloblen;
5983 unsigned char request[5], *response, *p;
5984 int responselen;
5985 int keyi, nkeys;
5986 int authed;
5987 char *pkblob, *alg, *commentp;
5988 int pklen, alglen, commentlen;
5989 int siglen, retlen, len;
5990 char *q, *agentreq, *ret;
5991 int try_send;
73feed4f 5992 int num_env, env_left, env_ok;
ff3187f6 5993 struct Packet *pktout;
51470298 5994 };
5995 crState(do_ssh2_authconn_state);
5996
5997 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 5998
7cca0d81 5999 /*
6000 * Request userauth protocol, and await a response to it.
6001 */
ff3187f6 6002 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6003 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6004 ssh2_pkt_send(ssh, s->pktout);
6005 crWaitUntilV(pktin);
6006 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 6007 bombout(("Server refused user authentication protocol"));
7ffdbc1a 6008 crStopV;
8d5de777 6009 }
7cca0d81 6010
6011 /*
1408a877 6012 * We repeat this whole loop, including the username prompt,
6013 * until we manage a successful authentication. If the user
51470298 6014 * types the wrong _password_, they can be sent back to the
6015 * beginning to try another username, if this is configured on.
6016 * (If they specify a username in the config, they are never
6017 * asked, even if they do give a wrong password.)
1408a877 6018 *
6019 * I think this best serves the needs of
6020 *
6021 * - the people who have no configuration, no keys, and just
6022 * want to try repeated (username,password) pairs until they
6023 * type both correctly
6024 *
6025 * - people who have keys and configuration but occasionally
6026 * need to fall back to passwords
6027 *
6028 * - people with a key held in Pageant, who might not have
6029 * logged in to a particular machine before; so they want to
6030 * type a username, and then _either_ their key will be
6031 * accepted, _or_ they will type a password. If they mistype
6032 * the username they will want to be able to get back and
6033 * retype it!
7cca0d81 6034 */
51470298 6035 s->username[0] = '\0';
6036 s->got_username = FALSE;
1408a877 6037 do {
1408a877 6038 /*
6039 * Get a username.
6040 */
86916870 6041 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 6042 /*
6043 * We got a username last time round this loop, and
6044 * with change_username turned off we don't try to get
6045 * it again.
6046 */
aa09f7d0 6047 } else if (!*ssh->cfg.username) {
c0a81592 6048 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 6049 if (!ssh_get_line("login as: ",
51470298 6050 s->username, sizeof(s->username), FALSE)) {
32874aea 6051 /*
6052 * get_line failed to get a username.
6053 * Terminate.
6054 */
6055 logevent("No username provided. Abandoning session.");
3bb2f322 6056 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6057 crStopV;
32874aea 6058 }
6059 } else {
51470298 6060 int ret; /* need not be saved across crReturn */
6061 c_write_str(ssh, "login as: ");
6062 ssh->send_ok = 1;
6063 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 6064 do {
ff3187f6 6065 crWaitUntilV(!pktin);
51470298 6066 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6067 } while (ret == 0);
6068 if (ret < 0)
6069 cleanup_exit(0);
4ca0c9d1 6070 c_write_str(ssh, "\r\n");
32874aea 6071 }
51470298 6072 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 6073 } else {
57356d63 6074 char *stuff;
86916870 6075 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 6076 s->username[sizeof(s->username)-1] = '\0';
65a22376 6077 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 6078 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 6079 c_write_str(ssh, stuff);
57356d63 6080 sfree(stuff);
7cca0d81 6081 }
6082 }
51470298 6083 s->got_username = TRUE;
7cca0d81 6084
65a22376 6085 /*
1408a877 6086 * Send an authentication request using method "none": (a)
6087 * just in case it succeeds, and (b) so that we know what
6088 * authentication methods we can usefully try next.
65a22376 6089 */
51470298 6090 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6091
ff3187f6 6092 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6093 ssh2_pkt_addstring(s->pktout, s->username);
6094 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6095 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6096 ssh2_pkt_send(ssh, s->pktout);
51470298 6097 s->type = AUTH_TYPE_NONE;
6098 s->gotit = FALSE;
6099 s->we_are_in = FALSE;
6100
6101 s->tried_pubkey_config = FALSE;
6102 s->tried_agent = FALSE;
51470298 6103 s->kbd_inter_running = FALSE;
6ac3a551 6104 s->kbd_inter_refused = FALSE;
86916870 6105 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 6106 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 6107 int keytype;
6c6d9ed9 6108 logeventf(ssh, "Reading private key file \"%.150s\"",
6109 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 6110 keytype = key_type(&ssh->cfg.keyfile);
51470298 6111 if (keytype == SSH_KEYTYPE_SSH2) {
6112 s->publickey_blob =
9a30e26b 6113 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 6114 &s->publickey_bloblen, NULL);
51470298 6115 } else {
57356d63 6116 char *msgbuf;
c2ad7d0d 6117 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 6118 key_type_to_str(keytype));
57356d63 6119 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 6120 " (%s)\r\n",
6121 filename_to_str(&ssh->cfg.keyfile),
57356d63 6122 key_type_to_str(keytype));
51470298 6123 c_write_str(ssh, msgbuf);
57356d63 6124 sfree(msgbuf);
51470298 6125 s->publickey_blob = NULL;
231ee168 6126 }
396778f1 6127 } else
51470298 6128 s->publickey_blob = NULL;
65a22376 6129
1408a877 6130 while (1) {
6131 /*
6132 * Wait for the result of the last authentication request.
6133 */
51470298 6134 if (!s->gotit)
ff3187f6 6135 crWaitUntilV(pktin);
6136 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 6137 char *banner;
6138 int size;
6139 /*
6140 * Don't show the banner if we're operating in
6141 * non-verbose non-interactive mode. (It's probably
6142 * a script, which means nobody will read the
6143 * banner _anyway_, and moreover the printing of
6144 * the banner will screw up processing on the
6145 * output of (say) plink.)
6146 */
6147 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 6148 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 6149 if (banner)
51470298 6150 c_write_untrusted(ssh, banner, size);
32874aea 6151 }
ff3187f6 6152 crWaitUntilV(pktin);
1408a877 6153 }
ff3187f6 6154 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6155 logevent("Access granted");
51470298 6156 s->we_are_in = TRUE;
1408a877 6157 break;
6158 }
65a22376 6159
51470298 6160 if (s->kbd_inter_running &&
ff3187f6 6161 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 6162 /*
45068b27 6163 * This is either a further set-of-prompts packet
6164 * in keyboard-interactive authentication, or it's
6165 * the same one and we came back here with `gotit'
6166 * set. In the former case, we must reset the
6167 * curr_prompt variable.
b3186d64 6168 */
51470298 6169 if (!s->gotit)
6170 s->curr_prompt = 0;
4c6e53e3 6171 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6172 /* FIXME: perhaps we should support this? */
6173 bombout(("PASSWD_CHANGEREQ not yet supported"));
6174 crStopV;
ff3187f6 6175 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 6176 bombout(("Strange packet received during authentication: type %d",
ff3187f6 6177 pktin->type));
7ffdbc1a 6178 crStopV;
65a22376 6179 }
6180
51470298 6181 s->gotit = FALSE;
65a22376 6182
1408a877 6183 /*
6184 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6185 * we can look at the string in it and know what we can
6186 * helpfully try next.
6187 */
ff3187f6 6188 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6189 char *methods;
6190 int methlen;
ff3187f6 6191 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 6192 s->kbd_inter_running = FALSE;
ff3187f6 6193 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6194 /*
6195 * We have received an unequivocal Access
6196 * Denied. This can translate to a variety of
6197 * messages:
6198 *
6199 * - if we'd just tried "none" authentication,
6200 * it's not worth printing anything at all
6201 *
6202 * - if we'd just tried a public key _offer_,
6203 * the message should be "Server refused our
6204 * key" (or no message at all if the key
6205 * came from Pageant)
6206 *
6207 * - if we'd just tried anything else, the
6208 * message really should be "Access denied".
6209 *
6210 * Additionally, if we'd just tried password
6211 * authentication, we should break out of this
6212 * whole loop so as to go back to the username
91f57d1f 6213 * prompt (iff we're configured to allow
6214 * username change attempts).
1408a877 6215 */
51470298 6216 if (s->type == AUTH_TYPE_NONE) {
1408a877 6217 /* do nothing */
51470298 6218 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6219 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6220 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6221 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6222 logevent("Server refused public key");
51470298 6223 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6224 /* server declined keyboard-interactive; ignore */
1408a877 6225 } else {
51470298 6226 c_write_str(ssh, "Access denied\r\n");
1408a877 6227 logevent("Access denied");
91f57d1f 6228 if (s->type == AUTH_TYPE_PASSWORD &&
6229 ssh->cfg.change_username) {
6c9dce7c 6230 /* XXX perhaps we should allow
6231 * keyboard-interactive to do this too? */
51470298 6232 s->we_are_in = FALSE;
1408a877 6233 break;
6234 }
6235 }
6236 } else {
51470298 6237 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6238 logevent("Further authentication required");
6239 }
65a22376 6240
51470298 6241 s->can_pubkey =
32874aea 6242 in_commasep_string("publickey", methods, methlen);
51470298 6243 s->can_passwd =
32874aea 6244 in_commasep_string("password", methods, methlen);
86916870 6245 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6246 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6247 }
65a22376 6248
51470298 6249 s->method = 0;
6250 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 6251 s->need_pw = FALSE;
65a22376 6252
0405e71f 6253 /*
6254 * Most password/passphrase prompts will be
6255 * non-echoing, so we set this to 0 by default.
6256 * Exception is that some keyboard-interactive prompts
6257 * can be echoing, in which case we'll set this to 1.
6258 */
51470298 6259 s->echo = 0;
0405e71f 6260
51470298 6261 if (!s->method && s->can_pubkey &&
6262 agent_exists() && !s->tried_agent) {
1983e559 6263 /*
6264 * Attempt public-key authentication using Pageant.
6265 */
1983e559 6266 void *r;
51470298 6267 s->authed = FALSE;
1983e559 6268
51470298 6269 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6270 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6271
51470298 6272 s->tried_agent = TRUE;
1983e559 6273
6274 logevent("Pageant is running. Requesting keys.");
6275
6276 /* Request the keys held by the agent. */
51470298 6277 PUT_32BIT(s->request, 1);
6278 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 6279 if (!agent_query(s->request, 5, &r, &s->responselen,
6280 ssh_agent_callback, ssh)) {
6281 do {
6282 crReturnV;
ff3187f6 6283 if (pktin) {
839f10db 6284 bombout(("Unexpected data from server while"
6285 " waiting for agent response"));
6286 crStopV;
6287 }
ff3187f6 6288 } while (pktin || inlen > 0);
839f10db 6289 r = ssh->agent_response;
6290 s->responselen = ssh->agent_response_len;
6291 }
51470298 6292 s->response = (unsigned char *) r;
6293 if (s->response && s->responselen >= 5 &&
6294 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6295 s->p = s->response + 5;
6296 s->nkeys = GET_32BIT(s->p);
6297 s->p += 4;
32874aea 6298 {
6299 char buf[64];
51470298 6300 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 6301 logevent(buf);
6302 }
51470298 6303 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 6304 void *vret;
1983e559 6305
32874aea 6306 {
6307 char buf[64];
51470298 6308 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 6309 logevent(buf);
6310 }
51470298 6311 s->pklen = GET_32BIT(s->p);
6312 s->p += 4;
6313 if (s->publickey_blob &&
6314 s->pklen == s->publickey_bloblen &&
6315 !memcmp(s->p, s->publickey_blob,
6316 s->publickey_bloblen)) {
396778f1 6317 logevent("This key matches configured key file");
51470298 6318 s->tried_pubkey_config = 1;
396778f1 6319 }
d8baa528 6320 s->pkblob = (char *)s->p;
51470298 6321 s->p += s->pklen;
6322 s->alglen = GET_32BIT(s->pkblob);
6323 s->alg = s->pkblob + 4;
6324 s->commentlen = GET_32BIT(s->p);
6325 s->p += 4;
d8baa528 6326 s->commentp = (char *)s->p;
51470298 6327 s->p += s->commentlen;
ff3187f6 6328 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6329 ssh2_pkt_addstring(s->pktout, s->username);
6330 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6331 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6332 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6333 ssh2_pkt_addstring_start(s->pktout);
6334 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6335 ssh2_pkt_addstring_start(s->pktout);
6336 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6337 ssh2_pkt_send(ssh, s->pktout);
6338
6339 crWaitUntilV(pktin);
6340 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6341 logevent("Key refused");
6342 continue;
6343 }
6344
32874aea 6345 if (flags & FLAG_VERBOSE) {
51470298 6346 c_write_str(ssh, "Authenticating with "
6347 "public key \"");
6348 c_write(ssh, s->commentp, s->commentlen);
6349 c_write_str(ssh, "\" from agent\r\n");
32874aea 6350 }
1983e559 6351
6352 /*
6353 * Server is willing to accept the key.
6354 * Construct a SIGN_REQUEST.
6355 */
ff3187f6 6356 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6357 ssh2_pkt_addstring(s->pktout, s->username);
6358 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6359 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6360 ssh2_pkt_addbool(s->pktout, TRUE);
6361 ssh2_pkt_addstring_start(s->pktout);
6362 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6363 ssh2_pkt_addstring_start(s->pktout);
6364 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6365
6366 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 6367 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6368 s->siglen -= 4;
51470298 6369 s->len = 1; /* message type */
6370 s->len += 4 + s->pklen; /* key blob */
6371 s->len += 4 + s->siglen; /* data to sign */
6372 s->len += 4; /* flags */
3d88e64d 6373 s->agentreq = snewn(4 + s->len, char);
51470298 6374 PUT_32BIT(s->agentreq, s->len);
6375 s->q = s->agentreq + 4;
6376 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6377 PUT_32BIT(s->q, s->pklen);
6378 s->q += 4;
6379 memcpy(s->q, s->pkblob, s->pklen);
6380 s->q += s->pklen;
6381 PUT_32BIT(s->q, s->siglen);
6382 s->q += 4;
1983e559 6383 /* Now the data to be signed... */
dda87a28 6384 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6385 PUT_32BIT(s->q, 20);
6386 s->q += 4;
6387 }
51470298 6388 memcpy(s->q, ssh->v2_session_id, 20);
6389 s->q += 20;
ff3187f6 6390 memcpy(s->q, s->pktout->data + 5,
6391 s->pktout->length - 5);
6392 s->q += s->pktout->length - 5;
1983e559 6393 /* And finally the (zero) flags word. */
51470298 6394 PUT_32BIT(s->q, 0);
839f10db 6395 if (!agent_query(s->agentreq, s->len + 4,
6396 &vret, &s->retlen,
6397 ssh_agent_callback, ssh)) {
6398 do {
6399 crReturnV;
ff3187f6 6400 if (pktin) {
839f10db 6401 bombout(("Unexpected data from server"
6402 " while waiting for agent"
6403 " response"));
6404 crStopV;
6405 }
ff3187f6 6406 } while (pktin || inlen > 0);
839f10db 6407 vret = ssh->agent_response;
6408 s->retlen = ssh->agent_response_len;
6409 }
51470298 6410 s->ret = vret;
6411 sfree(s->agentreq);
6412 if (s->ret) {
6413 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 6414 logevent("Sending Pageant's response");
ff3187f6 6415 ssh2_add_sigblob(ssh, s->pktout,
6416 s->pkblob, s->pklen,
51470298 6417 s->ret + 9,
6418 GET_32BIT(s->ret + 5));
ff3187f6 6419 ssh2_pkt_send(ssh, s->pktout);
51470298 6420 s->authed = TRUE;
1983e559 6421 break;
6422 } else {
32874aea 6423 logevent
6424 ("Pageant failed to answer challenge");
51470298 6425 sfree(s->ret);
1983e559 6426 }
6427 }
6428 }
51470298 6429 if (s->authed)
1983e559 6430 continue;
6431 }
29b1d0b3 6432 sfree(s->response);
1983e559 6433 }
6434
51470298 6435 if (!s->method && s->can_pubkey && s->publickey_blob
6436 && !s->tried_pubkey_config) {
1408a877 6437 unsigned char *pub_blob;
6438 char *algorithm, *comment;
6439 int pub_blob_len;
65a22376 6440
51470298 6441 s->tried_pubkey_config = TRUE;
65a22376 6442
51470298 6443 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6444 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6445
65a22376 6446 /*
1408a877 6447 * Try the public key supplied in the configuration.
6448 *
6449 * First, offer the public blob to see if the server is
6450 * willing to accept it.
65a22376 6451 */
d8baa528 6452 pub_blob =
9a30e26b 6453 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6454 &algorithm,
222d54dc 6455 &pub_blob_len,
6456 NULL);
1408a877 6457 if (pub_blob) {
ff3187f6 6458 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6459 ssh2_pkt_addstring(s->pktout, s->username);
6460 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6461 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6462 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6463 ssh2_pkt_addstring(s->pktout, algorithm);
6464 ssh2_pkt_addstring_start(s->pktout);
6465 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6466 pub_blob_len);
ff3187f6 6467 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6468 logevent("Offered public key");
1408a877 6469
ff3187f6 6470 crWaitUntilV(pktin);
6471 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6472 s->gotit = TRUE;
6473 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6474 continue; /* key refused; give up on it */
1408a877 6475 }
65a22376 6476
1408a877 6477 logevent("Offer of public key accepted");
65a22376 6478 /*
1408a877 6479 * Actually attempt a serious authentication using
6480 * the key.
65a22376 6481 */
9a30e26b 6482 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6483 sprintf(s->pwprompt,
32874aea 6484 "Passphrase for key \"%.100s\": ",
6485 comment);
51470298 6486 s->need_pw = TRUE;
1408a877 6487 } else {
51470298 6488 s->need_pw = FALSE;
1408a877 6489 }
4e520718 6490 if (flags & FLAG_VERBOSE) {
6491 c_write_str(ssh, "Authenticating with public key \"");
6492 c_write_str(ssh, comment);
6493 c_write_str(ssh, "\"\r\n");
6494 }
51470298 6495 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6496 }
1408a877 6497 }
6498
6f64ce13 6499 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6500 !s->kbd_inter_running) {
51470298 6501 s->method = AUTH_KEYBOARD_INTERACTIVE;
6502 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6503
51470298 6504 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6505 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6506
ff3187f6 6507 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6508 ssh2_pkt_addstring(s->pktout, s->username);
6509 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6510 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6511 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6512 ssh2_pkt_addstring(s->pktout, "");
6513 ssh2_pkt_send(ssh, s->pktout);
6514
6515 crWaitUntilV(pktin);
6516 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6517 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6518 s->gotit = TRUE;
af659722 6519 logevent("Keyboard-interactive authentication refused");
51470298 6520 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6ac3a551 6521 s->kbd_inter_refused = TRUE; /* don't try it again */
af659722 6522 continue;
6523 }
6524
51470298 6525 s->kbd_inter_running = TRUE;
6526 s->curr_prompt = 0;
af659722 6527 }
6528
51470298 6529 if (s->kbd_inter_running) {
6530 s->method = AUTH_KEYBOARD_INTERACTIVE;
6531 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6532
51470298 6533 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6534 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6535
51470298 6536 if (s->curr_prompt == 0) {
45068b27 6537 /*
6538 * We've got a fresh USERAUTH_INFO_REQUEST.
6539 * Display header data, and start going through
6540 * the prompts.
6541 */
6542 char *name, *inst, *lang;
6543 int name_len, inst_len, lang_len;
6544
ff3187f6 6545 ssh_pkt_getstring(pktin, &name, &name_len);
6546 ssh_pkt_getstring(pktin, &inst, &inst_len);
6547 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6548 if (name_len > 0) {
51470298 6549 c_write_untrusted(ssh, name, name_len);
6550 c_write_str(ssh, "\r\n");
45068b27 6551 }
6552 if (inst_len > 0) {
51470298 6553 c_write_untrusted(ssh, inst, inst_len);
6554 c_write_str(ssh, "\r\n");
45068b27 6555 }
ff3187f6 6556 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6557 }
af659722 6558
45068b27 6559 /*
6560 * If there are prompts remaining in the packet,
6561 * display one and get a response.
6562 */
51470298 6563 if (s->curr_prompt < s->num_prompts) {
45068b27 6564 char *prompt;
6565 int prompt_len;
af659722 6566
ff3187f6 6567 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6568 if (prompt_len > 0) {
85fdbe25 6569 static const char trunc[] = "<prompt truncated>: ";
6570 static const int prlen = sizeof(s->pwprompt) -
6571 lenof(trunc);
6572 if (prompt_len > prlen) {
6573 memcpy(s->pwprompt, prompt, prlen);
6574 strcpy(s->pwprompt + prlen, trunc);
6575 } else {
6576 memcpy(s->pwprompt, prompt, prompt_len);
6577 s->pwprompt[prompt_len] = '\0';
6578 }
45068b27 6579 } else {
51470298 6580 strcpy(s->pwprompt,
45068b27 6581 "<server failed to send prompt>: ");
6582 }
ff3187f6 6583 s->echo = ssh2_pkt_getbool(pktin);
51470298 6584 s->need_pw = TRUE;
45068b27 6585 } else
51470298 6586 s->need_pw = FALSE;
af659722 6587 }
6588
51470298 6589 if (!s->method && s->can_passwd) {
6590 s->method = AUTH_PASSWORD;
6591 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6592 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6593 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6594 ssh->savedhost);
6595 s->need_pw = TRUE;
1408a877 6596 }
6597
51470298 6598 if (s->need_pw) {
fa17a66e 6599 if (ssh_get_line) {
51470298 6600 if (!ssh_get_line(s->pwprompt, s->password,
6601 sizeof(s->password), TRUE)) {
1408a877 6602 /*
fa17a66e 6603 * get_line failed to get a password (for
6604 * example because one was supplied on the
6605 * command line which has already failed to
6606 * work). Terminate.
1408a877 6607 */
ff3187f6 6608 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6609 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6610 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6611 " to try");
ff3187f6 6612 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6613 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6614 logevent("Unable to authenticate");
a8327734 6615 connection_fatal(ssh->frontend,
6616 "Unable to authenticate");
3bb2f322 6617 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6618 crStopV;
1408a877 6619 }
6620 } else {
51470298 6621 int ret; /* need not be saved across crReturn */
6622 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6623 ssh->send_ok = 1;
1408a877 6624
51470298 6625 setup_userpass_input(ssh, s->password,
6626 sizeof(s->password), s->echo);
0405e71f 6627 do {
ff3187f6 6628 crWaitUntilV(!pktin);
51470298 6629 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6630 } while (ret == 0);
6631 if (ret < 0)
6632 cleanup_exit(0);
51470298 6633 c_write_str(ssh, "\r\n");
65a22376 6634 }
65a22376 6635 }
65a22376 6636
51470298 6637 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6638 /*
6639 * We have our passphrase. Now try the actual authentication.
6640 */
6641 struct ssh2_userkey *key;
222d54dc 6642 const char *error = NULL;
65a22376 6643
222d54dc 6644 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6645 &error);
1408a877 6646 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6647 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6648 c_write_str(ssh, "Wrong passphrase\r\n");
6649 s->tried_pubkey_config = FALSE;
1408a877 6650 } else {
222d54dc 6651 c_write_str(ssh, "Unable to load private key (");
6652 c_write_str(ssh, error);
6653 c_write_str(ssh, ")\r\n");
51470298 6654 s->tried_pubkey_config = TRUE;
1408a877 6655 }
6656 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6657 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6658 ssh2_pkt_addstring(s->pktout, s->username);
6659 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6660 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6661 ssh2_pkt_send(ssh, s->pktout);
51470298 6662 s->type = AUTH_TYPE_NONE;
1408a877 6663 } else {
1dd353b5 6664 unsigned char *pkblob, *sigblob, *sigdata;
6665 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6666 int p;
65a22376 6667
1408a877 6668 /*
6669 * We have loaded the private key and the server
6670 * has announced that it's willing to accept it.
6671 * Hallelujah. Generate a signature and send it.
6672 */
ff3187f6 6673 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6674 ssh2_pkt_addstring(s->pktout, s->username);
6675 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6676 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6677 ssh2_pkt_addbool(s->pktout, TRUE);
6678 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6679 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6680 ssh2_pkt_addstring_start(s->pktout);
6681 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6682
6683 /*
6684 * The data to be signed is:
6685 *
6686 * string session-id
6687 *
6688 * followed by everything so far placed in the
6689 * outgoing packet.
6690 */
ff3187f6 6691 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6692 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6693 sigdata_len -= 4;
92d60585 6694 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6695 p = 0;
6696 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6697 PUT_32BIT(sigdata+p, 20);
6698 p += 4;
6699 }
6700 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6701 memcpy(sigdata+p, s->pktout->data + 5,
6702 s->pktout->length - 5);
6703 p += s->pktout->length - 5;
dda87a28 6704 assert(p == sigdata_len);
d8baa528 6705 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6706 sigdata_len, &sigblob_len);
ff3187f6 6707 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6708 sigblob, sigblob_len);
6709 sfree(pkblob);
6710 sfree(sigblob);
1408a877 6711 sfree(sigdata);
6712
ff3187f6 6713 ssh2_pkt_send(ssh, s->pktout);
51470298 6714 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6715 key->alg->freekey(key->data);
1408a877 6716 }
51470298 6717 } else if (s->method == AUTH_PASSWORD) {
65a22376 6718 /*
1408a877 6719 * We send the password packet lumped tightly together with
6720 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6721 * string long enough to make the total length of the two
6722 * packets constant. This should ensure that a passive
6723 * listener doing traffic analyis can't work out the length
6724 * of the password.
6725 *
6726 * For this to work, we need an assumption about the
6727 * maximum length of the password packet. I think 256 is
6728 * pretty conservative. Anyone using a password longer than
6729 * that probably doesn't have much to worry about from
6730 * people who find out how long their password is!
65a22376 6731 */
ff3187f6 6732 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6733 ssh2_pkt_addstring(s->pktout, s->username);
6734 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6735 ssh2_pkt_addstring(s->pktout, "password");
6736 ssh2_pkt_addbool(s->pktout, FALSE);
6737 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6738 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 6739 memset(s->password, 0, sizeof(s->password));
ff3187f6 6740 end_log_omission(ssh, s->pktout);
6741 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6742 /*
1408a877 6743 * We'll include a string that's an exact multiple of the
6744 * cipher block size. If the cipher is NULL for some
6745 * reason, we don't do this trick at all because we gain
6746 * nothing by it.
65a22376 6747 */
51470298 6748 if (ssh->cscipher) {
32874aea 6749 int stringlen, i;
6750
51470298 6751 stringlen = (256 - ssh->deferred_len);
6752 stringlen += ssh->cscipher->blksize - 1;
6753 stringlen -= (stringlen % ssh->cscipher->blksize);
6754 if (ssh->cscomp) {
32874aea 6755 /*
6756 * Temporarily disable actual compression,
6757 * so we can guarantee to get this string
6758 * exactly the length we want it. The
6759 * compression-disabling routine should
6760 * return an integer indicating how many
6761 * bytes we should adjust our string length
6762 * by.
6763 */
5366aed8 6764 stringlen -=
6765 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 6766 }
ff3187f6 6767 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6768 ssh2_pkt_addstring_start(s->pktout);
6e9e9520 6769 for (i = 0; i < stringlen; i++) {
32874aea 6770 char c = (char) random_byte();
ff3187f6 6771 ssh2_pkt_addstring_data(s->pktout, &c, 1);
65a22376 6772 }
ff3187f6 6773 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6774 }
51470298 6775 ssh_pkt_defersend(ssh);
0d43337a 6776 logevent("Sent password");
51470298 6777 s->type = AUTH_TYPE_PASSWORD;
6778 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6779 if (s->curr_prompt == 0) {
ff3187f6 6780 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6781 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 6782 }
51470298 6783 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 6784 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6785 ssh2_pkt_addstring(s->pktout, s->password);
51470298 6786 memset(s->password, 0, sizeof(s->password));
ff3187f6 6787 end_log_omission(ssh, s->pktout);
51470298 6788 s->curr_prompt++;
45068b27 6789 }
51470298 6790 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 6791 ssh2_pkt_send(ssh, s->pktout);
45068b27 6792 } else {
6793 /*
6794 * If there are prompts remaining, we set
6795 * `gotit' so that we won't attempt to get
6796 * another packet. Then we go back round the
6797 * loop and will end up retrieving another
6798 * prompt out of the existing packet. Funky or
6799 * what?
6800 */
51470298 6801 s->gotit = TRUE;
45068b27 6802 }
51470298 6803 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 6804 } else {
51470298 6805 c_write_str(ssh, "No supported authentication methods"
6806 " left to try!\r\n");
6807 logevent("No supported authentications offered."
6808 " Disconnecting");
ff3187f6 6809 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6810 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6811 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 6812 " methods available");
ff3187f6 6813 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6814 ssh2_pkt_send_noqueue(ssh, s->pktout);
3bb2f322 6815 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6816 crStopV;
65a22376 6817 }
65a22376 6818 }
51470298 6819 } while (!s->we_are_in);
7cca0d81 6820
6821 /*
6822 * Now we're authenticated for the connection protocol. The
6823 * connection protocol will automatically have started at this
6824 * point; there's no need to send SERVICE_REQUEST.
6825 */
6826
0ed48730 6827 ssh->channels = newtree234(ssh_channelcmp);
6828
7cca0d81 6829 /*
b09eaa88 6830 * Set up handlers for some connection protocol messages, so we
6831 * don't have to handle them repeatedly in this coroutine.
6832 */
6833 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6834 ssh2_msg_channel_window_adjust;
51df0ab5 6835 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6836 ssh2_msg_global_request;
b09eaa88 6837
6838 /*
0ed48730 6839 * Create the main session channel.
7cca0d81 6840 */
0ed48730 6841 if (!ssh->cfg.ssh_no_shell) {
6842 ssh->mainchan = snew(struct ssh_channel);
6843 ssh->mainchan->ssh = ssh;
6844 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 6845 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6846 ssh2_pkt_addstring(s->pktout, "session");
6847 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 6848 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 6849 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6850 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6851 ssh2_pkt_send(ssh, s->pktout);
6852 crWaitUntilV(pktin);
6853 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 6854 bombout(("Server refused to open a session"));
6855 crStopV;
6856 /* FIXME: error data comes back in FAILURE packet */
6857 }
ff3187f6 6858 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 6859 bombout(("Server's channel confirmation cited wrong channel"));
6860 crStopV;
6861 }
ff3187f6 6862 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 6863 ssh->mainchan->type = CHAN_MAINSESSION;
6864 ssh->mainchan->closes = 0;
ff3187f6 6865 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6866 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 6867 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6868 add234(ssh->channels, ssh->mainchan);
62638676 6869 update_specials_menu(ssh->frontend);
0ed48730 6870 logevent("Opened channel for session");
6871 } else
6872 ssh->mainchan = NULL;
7cca0d81 6873
6874 /*
51df0ab5 6875 * Now we have a channel, make dispatch table entries for
6876 * general channel-based messages.
6877 */
6878 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6879 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6880 ssh2_msg_channel_data;
6881 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6882 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6883 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6884 ssh2_msg_channel_open_confirmation;
6885 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6886 ssh2_msg_channel_open_failure;
6887 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6888 ssh2_msg_channel_request;
6889 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6890 ssh2_msg_channel_open;
6891
6892 /*
783415f8 6893 * Potentially enable X11 forwarding.
6894 */
0ed48730 6895 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 6896 char proto[20], data[64];
6897 logevent("Requesting X11 forwarding");
302121de 6898 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 6899 data, sizeof(data), ssh->cfg.x11_auth);
6900 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 6901 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6902 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6903 ssh2_pkt_addstring(s->pktout, "x11-req");
6904 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6905 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6906 ssh2_pkt_addstring(s->pktout, proto);
6907 ssh2_pkt_addstring(s->pktout, data);
6908 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6909 ssh2_pkt_send(ssh, s->pktout);
32874aea 6910
b09eaa88 6911 crWaitUntilV(pktin);
32874aea 6912
ff3187f6 6913 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6914 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6915 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 6916 " packet type %d", pktin->type));
7ffdbc1a 6917 crStopV;
32874aea 6918 }
6919 logevent("X11 forwarding refused");
6920 } else {
6921 logevent("X11 forwarding enabled");
51470298 6922 ssh->X11_fwd_enabled = TRUE;
32874aea 6923 }
783415f8 6924 }
6925
6926 /*
bc240b21 6927 * Enable port forwardings.
6928 */
06fadff5 6929 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 6930
6931 /*
36c2a3e9 6932 * Potentially enable agent forwarding.
6933 */
0ed48730 6934 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6935 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6936 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6937 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6938 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6939 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6940 ssh2_pkt_send(ssh, s->pktout);
32874aea 6941
b09eaa88 6942 crWaitUntilV(pktin);
32874aea 6943
ff3187f6 6944 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6945 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6946 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6947 " packet type %d", pktin->type));
7ffdbc1a 6948 crStopV;
32874aea 6949 }
6950 logevent("Agent forwarding refused");
6951 } else {
6952 logevent("Agent forwarding enabled");
51470298 6953 ssh->agentfwd_enabled = TRUE;
32874aea 6954 }
36c2a3e9 6955 }
6956
6957 /*
7cca0d81 6958 * Now allocate a pty for the session.
6959 */
0ed48730 6960 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6961 /* Unpick the terminal-speed string. */
6962 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6963 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6964 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6965 /* Build the pty request. */
ff3187f6 6966 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6967 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6968 ssh2_pkt_addstring(s->pktout, "pty-req");
6969 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6970 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6971 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6972 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6973 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6974 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6975 ssh2_pkt_addstring_start(s->pktout);
6976 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6977 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6978 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6979 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6980 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6981 ssh2_pkt_send(ssh, s->pktout);
51470298 6982 ssh->state = SSH_STATE_INTERMED;
32874aea 6983
b09eaa88 6984 crWaitUntilV(pktin);
32874aea 6985
ff3187f6 6986 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6987 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6988 bombout(("Unexpected response to pty request:"
ff3187f6 6989 " packet type %d", pktin->type));
7ffdbc1a 6990 crStopV;
32874aea 6991 }
51470298 6992 c_write_str(ssh, "Server refused to allocate pty\r\n");
6993 ssh->editing = ssh->echoing = 1;
32874aea 6994 } else {
a5dd8467 6995 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 6996 ssh->ospeed, ssh->ispeed);
32874aea 6997 }
0965bee0 6998 } else {
51470298 6999 ssh->editing = ssh->echoing = 1;
7cca0d81 7000 }
7001
7002 /*
73feed4f 7003 * Send environment variables.
7004 *
7005 * Simplest thing here is to send all the requests at once, and
7006 * then wait for a whole bunch of successes or failures.
7007 */
7008 if (ssh->mainchan && *ssh->cfg.environmt) {
7009 char *e = ssh->cfg.environmt;
7010 char *var, *varend, *val;
7011
7012 s->num_env = 0;
7013
7014 while (*e) {
7015 var = e;
7016 while (*e && *e != '\t') e++;
7017 varend = e;
7018 if (*e == '\t') e++;
7019 val = e;
7020 while (*e) e++;
7021 e++;
7022
ff3187f6 7023 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7024 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7025 ssh2_pkt_addstring(s->pktout, "env");
7026 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7027 ssh2_pkt_addstring_start(s->pktout);
7028 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7029 ssh2_pkt_addstring(s->pktout, val);
7030 ssh2_pkt_send(ssh, s->pktout);
73feed4f 7031
7032 s->num_env++;
7033 }
7034
7035 logeventf(ssh, "Sent %d environment variables", s->num_env);
7036
7037 s->env_ok = 0;
7038 s->env_left = s->num_env;
7039
7040 while (s->env_left > 0) {
b09eaa88 7041 crWaitUntilV(pktin);
73feed4f 7042
ff3187f6 7043 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7044 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 7045 bombout(("Unexpected response to environment request:"
ff3187f6 7046 " packet type %d", pktin->type));
73feed4f 7047 crStopV;
7048 }
7049 } else {
7050 s->env_ok++;
7051 }
7052
7053 s->env_left--;
7054 }
7055
7056 if (s->env_ok == s->num_env) {
7057 logevent("All environment variables successfully set");
7058 } else if (s->env_ok == 0) {
7059 logevent("All environment variables refused");
7060 c_write_str(ssh, "Server refused to set environment variables\r\n");
7061 } else {
7062 logeventf(ssh, "%d environment variables refused",
7063 s->num_env - s->env_ok);
7064 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7065 }
7066 }
7067
7068 /*
fd5e5847 7069 * Start a shell or a remote command. We may have to attempt
7070 * this twice if the config data has provided a second choice
7071 * of command.
7cca0d81 7072 */
0ed48730 7073 if (ssh->mainchan) while (1) {
fd5e5847 7074 int subsys;
7075 char *cmd;
7076
51470298 7077 if (ssh->fallback_cmd) {
86916870 7078 subsys = ssh->cfg.ssh_subsys2;
7079 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 7080 } else {
86916870 7081 subsys = ssh->cfg.ssh_subsys;
7082 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 7083 }
7084
ff3187f6 7085 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7086 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 7087 if (subsys) {
ff3187f6 7088 ssh2_pkt_addstring(s->pktout, "subsystem");
7089 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7090 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7091 } else if (*cmd) {
ff3187f6 7092 ssh2_pkt_addstring(s->pktout, "exec");
7093 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7094 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7095 } else {
ff3187f6 7096 ssh2_pkt_addstring(s->pktout, "shell");
7097 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 7098 }
ff3187f6 7099 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 7100
7101 crWaitUntilV(pktin);
7102
ff3187f6 7103 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7104 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7105 bombout(("Unexpected response to shell/command request:"
ff3187f6 7106 " packet type %d", pktin->type));
7ffdbc1a 7107 crStopV;
fd5e5847 7108 }
7109 /*
7110 * We failed to start the command. If this is the
7111 * fallback command, we really are finished; if it's
7112 * not, and if the fallback command exists, try falling
7113 * back to it before complaining.
7114 */
86916870 7115 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7116 logevent("Primary command failed; attempting fallback");
51470298 7117 ssh->fallback_cmd = TRUE;
fd5e5847 7118 continue;
7119 }
6b5cf8b4 7120 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7121 crStopV;
fd5e5847 7122 } else {
7123 logevent("Started a shell/command");
32874aea 7124 }
fd5e5847 7125 break;
7cca0d81 7126 }
7127
51470298 7128 ssh->state = SSH_STATE_SESSION;
7129 if (ssh->size_needed)
7130 ssh_size(ssh, ssh->term_width, ssh->term_height);
7131 if (ssh->eof_needed)
7132 ssh_special(ssh, TS_EOF);
6e48c3fe 7133
7cca0d81 7134 /*
7135 * Transfer data!
7136 */
b9d7bcad 7137 if (ssh->ldisc)
7138 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7139 if (ssh->mainchan)
7140 ssh->send_ok = 1;
7cca0d81 7141 while (1) {
e5574168 7142 crReturnV;
51470298 7143 s->try_send = FALSE;
ff3187f6 7144 if (pktin) {
2b7540a7 7145
51df0ab5 7146 /*
7147 * _All_ the connection-layer packets we expect to
7148 * receive are now handled by the dispatch table.
7149 * Anything that reaches here must be bogus.
7150 */
32874aea 7151
51df0ab5 7152 bombout(("Strange packet received: type %d", pktin->type));
7153 crStopV;
0ed48730 7154 } else if (ssh->mainchan) {
32874aea 7155 /*
7156 * We have spare data. Add it to the channel buffer.
7157 */
d8baa528 7158 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7159 s->try_send = TRUE;
32874aea 7160 }
51470298 7161 if (s->try_send) {
32874aea 7162 int i;
7163 struct ssh_channel *c;
7164 /*
7165 * Try to send data on all channels if we can.
7166 */
51470298 7167 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 7168 int bufsize;
7169 if (c->closes)
7170 continue; /* don't send on closing channels */
7171 bufsize = ssh2_try_send(c);
5471d09a 7172 if (bufsize == 0) {
7173 switch (c->type) {
7174 case CHAN_MAINSESSION:
7175 /* stdin need not receive an unthrottle
7176 * notification since it will be polled */
7177 break;
7178 case CHAN_X11:
7179 x11_unthrottle(c->u.x11.s);
7180 break;
7181 case CHAN_AGENT:
7182 /* agent sockets are request/response and need no
7183 * buffer management */
7184 break;
7185 case CHAN_SOCKDATA:
7186 pfd_unthrottle(c->u.pfd.s);
7187 break;
7188 }
7189 }
7190 }
7cca0d81 7191 }
e5574168 7192 }
7193
7194 crFinishV;
7195}
7196
7197/*
b09eaa88 7198 * Handlers for SSH2 messages that might arrive at any moment.
7199 */
7200void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7201{
7202 /* log reason code in disconnect message */
7203 char *buf, *msg;
7204 int nowlen, reason, msglen;
7205
7206 reason = ssh_pkt_getuint32(pktin);
7207 ssh_pkt_getstring(pktin, &msg, &msglen);
7208
7209 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7210 buf = dupprintf("Received disconnect message (%s)",
7211 ssh2_disconnect_reasons[reason]);
7212 } else {
7213 buf = dupprintf("Received disconnect message (unknown"
7214 " type %d)", reason);
7215 }
7216 logevent(buf);
7217 sfree(buf);
7218 buf = dupprintf("Disconnection message text: %n%.*s",
7219 &nowlen, msglen, msg);
7220 logevent(buf);
7221 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7222 reason,
7223 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7224 ssh2_disconnect_reasons[reason] : "unknown",
7225 buf+nowlen));
7226 sfree(buf);
7227}
7228
7229void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7230{
7231 /* log the debug message */
7232 char *buf, *msg;
7233 int msglen;
7234 int always_display;
7235
7236 /* XXX maybe we should actually take notice of this */
7237 always_display = ssh2_pkt_getbool(pktin);
7238 ssh_pkt_getstring(pktin, &msg, &msglen);
7239
7240 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7241 logevent(buf);
7242 sfree(buf);
7243}
7244
7245void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7246{
7247 struct Packet *pktout;
7248 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7249 ssh2_pkt_adduint32(pktout, pktin->sequence);
7250 /*
7251 * UNIMPLEMENTED messages MUST appear in the same order as the
7252 * messages they respond to. Hence, never queue them.
7253 */
7254 ssh2_pkt_send_noqueue(ssh, pktout);
7255}
7256
7257/*
7cca0d81 7258 * Handle the top-level SSH2 protocol.
7259 */
b09eaa88 7260static void ssh2_protocol_setup(Ssh ssh)
7261{
7262 int i;
7263
7264 /*
7265 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7266 */
7267 for (i = 0; i < 256; i++)
7268 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7269
7270 /*
7271 * Any message we actually understand, we set to NULL so that
7272 * the coroutines will get it.
7273 */
7274 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7275 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7276 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7277 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7278 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7279 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7280 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7281 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7282 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7283 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7284 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7285 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7286 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7287 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7288 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7289 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7290 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7291 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7292 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7293 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7294 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7295 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7296 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7297 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7298 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7299 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7300 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7301 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7302 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7303 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7304 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7305 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7306 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7307
7308 /*
7309 * These special message types we install handlers for.
7310 */
7311 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7312 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7313 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7314}
7315
9442dd57 7316static void ssh2_timer(void *ctx, long now)
7317{
7318 Ssh ssh = (Ssh)ctx;
7319
e6c1536e 7320 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 7321 now - ssh->next_rekey >= 0) {
f382c87d 7322 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 7323 }
7324}
7325
ff3187f6 7326static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7327 struct Packet *pktin)
7cca0d81 7328{
b09eaa88 7329 if (ssh->state == SSH_STATE_CLOSED)
7330 return;
7331
9442dd57 7332 if (pktin) {
7333 ssh->incoming_data_size += pktin->encrypted_len;
7334 if (!ssh->kex_in_progress &&
d57f70af 7335 ssh->max_data_size != 0 &&
7336 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7337 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 7338 }
7339
b09eaa88 7340 if (pktin && ssh->packet_dispatch[pktin->type]) {
7341 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7342 return;
b09eaa88 7343 }
7344
7345 if (!ssh->protocol_initial_phase_done ||
7346 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7347 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7348 !ssh->protocol_initial_phase_done) {
7349 ssh->protocol_initial_phase_done = TRUE;
7350 /*
7351 * Allow authconn to initialise itself.
7352 */
7353 do_ssh2_authconn(ssh, NULL, 0, NULL);
7354 }
7355 } else {
7356 do_ssh2_authconn(ssh, in, inlen, pktin);
7357 }
7cca0d81 7358}
7359
7360/*
8df7a775 7361 * Called to set up the connection.
374330e2 7362 *
7363 * Returns an error message, or NULL on success.
374330e2 7364 */
cbe2d68f 7365static const char *ssh_init(void *frontend_handle, void **backend_handle,
7366 Config *cfg,
79bf227b 7367 char *host, int port, char **realhost, int nodelay,
7368 int keepalive)
32874aea 7369{
cbe2d68f 7370 const char *p;
51470298 7371 Ssh ssh;
7372
3d88e64d 7373 ssh = snew(struct ssh_tag);
86916870 7374 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7375 ssh->version = 0; /* when not ready yet */
51470298 7376 ssh->s = NULL;
7377 ssh->cipher = NULL;
371e569c 7378 ssh->v1_cipher_ctx = NULL;
0183b242 7379 ssh->crcda_ctx = NULL;
51470298 7380 ssh->cscipher = NULL;
371e569c 7381 ssh->cs_cipher_ctx = NULL;
51470298 7382 ssh->sccipher = NULL;
371e569c 7383 ssh->sc_cipher_ctx = NULL;
51470298 7384 ssh->csmac = NULL;
a8327734 7385 ssh->cs_mac_ctx = NULL;
51470298 7386 ssh->scmac = NULL;
e0e1a00d 7387 ssh->sc_mac_ctx = NULL;
51470298 7388 ssh->cscomp = NULL;
5366aed8 7389 ssh->cs_comp_ctx = NULL;
51470298 7390 ssh->sccomp = NULL;
5366aed8 7391 ssh->sc_comp_ctx = NULL;
51470298 7392 ssh->kex = NULL;
389aa499 7393 ssh->kex_ctx = NULL;
51470298 7394 ssh->hostkey = NULL;
7395 ssh->exitcode = -1;
7396 ssh->state = SSH_STATE_PREPACKET;
7397 ssh->size_needed = FALSE;
7398 ssh->eof_needed = FALSE;
b9d7bcad 7399 ssh->ldisc = NULL;
a8327734 7400 ssh->logctx = NULL;
51470298 7401 ssh->deferred_send_data = NULL;
7402 ssh->deferred_len = 0;
7403 ssh->deferred_size = 0;
7404 ssh->fallback_cmd = 0;
7405 ssh->pkt_ctx = 0;
302121de 7406 ssh->x11auth = NULL;
be738459 7407 ssh->v1_compressing = FALSE;
51470298 7408 ssh->v2_outgoing_sequence = 0;
7409 ssh->ssh1_rdpkt_crstate = 0;
7410 ssh->ssh2_rdpkt_crstate = 0;
7411 ssh->do_ssh_init_crstate = 0;
7412 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7413 ssh->do_ssh1_connection_crstate = 0;
51470298 7414 ssh->do_ssh1_login_crstate = 0;
7415 ssh->do_ssh2_transport_crstate = 0;
7416 ssh->do_ssh2_authconn_crstate = 0;
7417 ssh->do_ssh_init_state = NULL;
7418 ssh->do_ssh1_login_state = NULL;
7419 ssh->do_ssh2_transport_state = NULL;
7420 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7421 ssh->mainchan = NULL;
968d2d92 7422 ssh->throttled_all = 0;
7423 ssh->v1_stdout_throttling = 0;
590f6a5f 7424 ssh->queue = NULL;
7425 ssh->queuelen = ssh->queuesize = 0;
7426 ssh->queueing = FALSE;
06fadff5 7427 ssh->qhead = ssh->qtail = NULL;
e13bba36 7428 ssh->deferred_rekey_reason = NULL;
51470298 7429
7430 *backend_handle = ssh;
32874aea 7431
8f203108 7432#ifdef MSCRYPTOAPI
32874aea 7433 if (crypto_startup() == 0)
8f203108 7434 return "Microsoft high encryption pack not installed!";
7435#endif
374330e2 7436
51470298 7437 ssh->frontend = frontend_handle;
86916870 7438 ssh->term_width = ssh->cfg.width;
7439 ssh->term_height = ssh->cfg.height;
887035a5 7440
fabd1805 7441 ssh->channels = NULL;
7442 ssh->rportfwds = NULL;
f47a5ffb 7443 ssh->portfwds = NULL;
fabd1805 7444
51470298 7445 ssh->send_ok = 0;
7446 ssh->editing = 0;
7447 ssh->echoing = 0;
7448 ssh->v1_throttle_count = 0;
7449 ssh->overall_bufsize = 0;
7450 ssh->fallback_cmd = 0;
8df7a775 7451
3648d4c5 7452 ssh->protocol = NULL;
7453
b09eaa88 7454 ssh->protocol_initial_phase_done = FALSE;
7455
39934deb 7456 ssh->pinger = NULL;
7457
9442dd57 7458 ssh->incoming_data_size = ssh->outgoing_data_size =
7459 ssh->deferred_data_size = 0L;
d57f70af 7460 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 7461 ssh->kex_in_progress = FALSE;
7462
79bf227b 7463 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7464 if (p != NULL)
7465 return p;
374330e2 7466
5d17ccfc 7467 random_ref();
7468
374330e2 7469 return NULL;
7470}
7471
fabd1805 7472static void ssh_free(void *handle)
7473{
7474 Ssh ssh = (Ssh) handle;
7475 struct ssh_channel *c;
7476 struct ssh_rportfwd *pf;
7477
7478 if (ssh->v1_cipher_ctx)
7479 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7480 if (ssh->cs_cipher_ctx)
7481 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7482 if (ssh->sc_cipher_ctx)
7483 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7484 if (ssh->cs_mac_ctx)
7485 ssh->csmac->free_context(ssh->cs_mac_ctx);
7486 if (ssh->sc_mac_ctx)
7487 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7488 if (ssh->cs_comp_ctx) {
7489 if (ssh->cscomp)
7490 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7491 else
7492 zlib_compress_cleanup(ssh->cs_comp_ctx);
7493 }
7494 if (ssh->sc_comp_ctx) {
7495 if (ssh->sccomp)
7496 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7497 else
7498 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7499 }
fabd1805 7500 if (ssh->kex_ctx)
7501 dh_cleanup(ssh->kex_ctx);
7502 sfree(ssh->savedhost);
7503
590f6a5f 7504 while (ssh->queuelen-- > 0)
7505 ssh_free_packet(ssh->queue[ssh->queuelen]);
7506 sfree(ssh->queue);
7507
06fadff5 7508 while (ssh->qhead) {
7509 struct queued_handler *qh = ssh->qhead;
7510 ssh->qhead = qh->next;
7511 sfree(ssh->qhead);
7512 }
7513 ssh->qhead = ssh->qtail = NULL;
7514
fabd1805 7515 if (ssh->channels) {
7516 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7517 switch (c->type) {
7518 case CHAN_X11:
7519 if (c->u.x11.s != NULL)
7520 x11_close(c->u.x11.s);
7521 break;
7522 case CHAN_SOCKDATA:
7523 if (c->u.pfd.s != NULL)
7524 pfd_close(c->u.pfd.s);
7525 break;
7526 }
7527 sfree(c);
7528 }
7529 freetree234(ssh->channels);
cdb52705 7530 ssh->channels = NULL;
fabd1805 7531 }
7532
7533 if (ssh->rportfwds) {
7534 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7535 sfree(pf);
7536 freetree234(ssh->rportfwds);
cdb52705 7537 ssh->rportfwds = NULL;
fabd1805 7538 }
7539 sfree(ssh->deferred_send_data);
7540 if (ssh->x11auth)
7541 x11_free_auth(ssh->x11auth);
7542 sfree(ssh->do_ssh_init_state);
7543 sfree(ssh->do_ssh1_login_state);
7544 sfree(ssh->do_ssh2_transport_state);
7545 sfree(ssh->do_ssh2_authconn_state);
679539d7 7546 if (ssh->crcda_ctx) {
7547 crcda_free_context(ssh->crcda_ctx);
7548 ssh->crcda_ctx = NULL;
7549 }
fabd1805 7550 if (ssh->s)
36f94d1f 7551 ssh_do_close(ssh);
9442dd57 7552 expire_timer_context(ssh);
39934deb 7553 if (ssh->pinger)
7554 pinger_free(ssh->pinger);
ee50e8b6 7555 sfree(ssh);
5d17ccfc 7556
7557 random_unref();
fabd1805 7558}
7559
374330e2 7560/*
86916870 7561 * Reconfigure the SSH backend.
86916870 7562 */
7563static void ssh_reconfig(void *handle, Config *cfg)
7564{
7565 Ssh ssh = (Ssh) handle;
e13bba36 7566 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 7567 unsigned long old_max_data_size;
7568
39934deb 7569 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
fda2feb1 7570 ssh_setup_portfwd(ssh, cfg);
e6c1536e 7571
7572 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7573 cfg->ssh_rekey_time != 0) {
7574 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7575 long now = GETTICKCOUNT();
7576
7577 if (new_next - now < 0) {
f382c87d 7578 rekeying = "timeout shortened";
e6c1536e 7579 } else {
7580 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7581 }
7582 }
7583
7584 old_max_data_size = ssh->max_data_size;
7585 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7586 if (old_max_data_size != ssh->max_data_size &&
7587 ssh->max_data_size != 0) {
7588 if (ssh->outgoing_data_size > ssh->max_data_size ||
7589 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7590 rekeying = "data limit lowered";
e6c1536e 7591 }
7592
e13bba36 7593 if (ssh->cfg.compression != cfg->compression) {
f382c87d 7594 rekeying = "compression setting changed";
e13bba36 7595 rekey_mandatory = TRUE;
7596 }
7597
7598 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7599 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7600 sizeof(ssh->cfg.ssh_cipherlist))) {
f382c87d 7601 rekeying = "cipher settings changed";
e13bba36 7602 rekey_mandatory = TRUE;
e6c1536e 7603 }
7604
86916870 7605 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 7606
7607 if (rekeying) {
7608 if (!ssh->kex_in_progress) {
7609 do_ssh2_transport(ssh, rekeying, -1, NULL);
7610 } else if (rekey_mandatory) {
7611 ssh->deferred_rekey_reason = rekeying;
7612 }
7613 }
86916870 7614}
7615
7616/*
374330e2 7617 * Called to send data down the Telnet connection.
7618 */
51470298 7619static int ssh_send(void *handle, char *buf, int len)
32874aea 7620{
51470298 7621 Ssh ssh = (Ssh) handle;
7622
7623 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7624 return 0;
374330e2 7625
d8baa528 7626 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7627
51470298 7628 return ssh_sendbuffer(ssh);
5471d09a 7629}
7630
7631/*
7632 * Called to query the current amount of buffered stdin data.
7633 */
51470298 7634static int ssh_sendbuffer(void *handle)
5471d09a 7635{
51470298 7636 Ssh ssh = (Ssh) handle;
5471d09a 7637 int override_value;
7638
51470298 7639 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7640 return 0;
7641
7642 /*
7643 * If the SSH socket itself has backed up, add the total backup
7644 * size on that to any individual buffer on the stdin channel.
7645 */
7646 override_value = 0;
51470298 7647 if (ssh->throttled_all)
7648 override_value = ssh->overall_bufsize;
5471d09a 7649
51470298 7650 if (ssh->version == 1) {
5471d09a 7651 return override_value;
51470298 7652 } else if (ssh->version == 2) {
7653 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7654 return override_value;
7655 else
51470298 7656 return (override_value +
7657 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7658 }
7659
7660 return 0;
374330e2 7661}
7662
7663/*
6e48c3fe 7664 * Called to set the size of the window from SSH's POV.
374330e2 7665 */
51470298 7666static void ssh_size(void *handle, int width, int height)
32874aea 7667{
51470298 7668 Ssh ssh = (Ssh) handle;
ff3187f6 7669 struct Packet *pktout;
51470298 7670
7671 ssh->term_width = width;
7672 ssh->term_height = height;
f278d6f8 7673
51470298 7674 switch (ssh->state) {
374330e2 7675 case SSH_STATE_BEFORE_SIZE:
3687d221 7676 case SSH_STATE_PREPACKET:
21248260 7677 case SSH_STATE_CLOSED:
374330e2 7678 break; /* do nothing */
7679 case SSH_STATE_INTERMED:
51470298 7680 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7681 break;
7682 case SSH_STATE_SESSION:
86916870 7683 if (!ssh->cfg.nopty) {
51470298 7684 if (ssh->version == 1) {
7685 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7686 PKT_INT, ssh->term_height,
7687 PKT_INT, ssh->term_width,
32874aea 7688 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7689 } else if (ssh->mainchan) {
ff3187f6 7690 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7691 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7692 ssh2_pkt_addstring(pktout, "window-change");
7693 ssh2_pkt_addbool(pktout, 0);
7694 ssh2_pkt_adduint32(pktout, ssh->term_width);
7695 ssh2_pkt_adduint32(pktout, ssh->term_height);
7696 ssh2_pkt_adduint32(pktout, 0);
7697 ssh2_pkt_adduint32(pktout, 0);
7698 ssh2_pkt_send(ssh, pktout);
32874aea 7699 }
7700 }
7701 break;
374330e2 7702 }
7703}
7704
7705/*
125105d1 7706 * Return a list of the special codes that make sense in this
7707 * protocol.
7708 */
7709static const struct telnet_special *ssh_get_specials(void *handle)
7710{
786ba75e 7711 static const struct telnet_special ssh1_ignore_special[] = {
7712 {"IGNORE message", TS_NOP}
7713 };
7714 static const struct telnet_special ssh2_transport_specials[] = {
62638676 7715 {"IGNORE message", TS_NOP},
9442dd57 7716 {"Repeat key exchange", TS_REKEY},
62638676 7717 };
7718 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7719 {NULL, TS_SEP},
7720 {"Break", TS_BRK},
786ba75e 7721 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 7722 * They include all the ISO C signals, but are a subset of the POSIX
7723 * required signals. */
7724 {"SIGINT (Interrupt)", TS_SIGINT},
7725 {"SIGTERM (Terminate)", TS_SIGTERM},
7726 {"SIGKILL (Kill)", TS_SIGKILL},
7727 {"SIGQUIT (Quit)", TS_SIGQUIT},
7728 {"SIGHUP (Hangup)", TS_SIGHUP},
7729 {"More signals", TS_SUBMENU},
7730 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7731 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7732 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7733 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7734 {NULL, TS_EXITMENU}
62638676 7735 };
7736 static const struct telnet_special specials_end[] = {
6f2d0cde 7737 {NULL, TS_EXITMENU}
62638676 7738 };
786ba75e 7739 /* XXX review this length for any changes: */
7740 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 7741 lenof(ssh2_session_specials) +
7742 lenof(specials_end)];
125105d1 7743 Ssh ssh = (Ssh) handle;
62638676 7744 int i = 0;
7745#define ADD_SPECIALS(name) \
7746 do { \
7747 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7748 memcpy(&ssh_specials[i], name, sizeof name); \
7749 i += lenof(name); \
7750 } while(0)
125105d1 7751
7752 if (ssh->version == 1) {
62638676 7753 /* Don't bother offering IGNORE if we've decided the remote
7754 * won't cope with it, since we wouldn't bother sending it if
7755 * asked anyway. */
7756 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 7757 ADD_SPECIALS(ssh1_ignore_special);
125105d1 7758 } else if (ssh->version == 2) {
786ba75e 7759 ADD_SPECIALS(ssh2_transport_specials);
62638676 7760 if (ssh->mainchan)
7761 ADD_SPECIALS(ssh2_session_specials);
7762 } /* else we're not ready yet */
7763
7764 if (i) {
7765 ADD_SPECIALS(specials_end);
7766 return ssh_specials;
7767 } else {
125105d1 7768 return NULL;
62638676 7769 }
7770#undef ADD_SPECIALS
125105d1 7771}
7772
7773/*
6abbf9e3 7774 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7775 * can send an EOF and collect resulting output (e.g. `plink
7776 * hostname sort').
374330e2 7777 */
51470298 7778static void ssh_special(void *handle, Telnet_Special code)
32874aea 7779{
51470298 7780 Ssh ssh = (Ssh) handle;
ff3187f6 7781 struct Packet *pktout;
51470298 7782
6abbf9e3 7783 if (code == TS_EOF) {
51470298 7784 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7785 /*
7786 * Buffer the EOF in case we are pre-SESSION, so we can
7787 * send it as soon as we reach SESSION.
7788 */
7789 if (code == TS_EOF)
51470298 7790 ssh->eof_needed = TRUE;
32874aea 7791 return;
7792 }
51470298 7793 if (ssh->version == 1) {
7794 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7795 } else if (ssh->mainchan) {
ff3187f6 7796 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7797 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7798 ssh2_pkt_send(ssh, pktout);
32874aea 7799 }
7800 logevent("Sent EOF message");
125105d1 7801 } else if (code == TS_PING || code == TS_NOP) {
51470298 7802 if (ssh->state == SSH_STATE_CLOSED
7803 || ssh->state == SSH_STATE_PREPACKET) return;
7804 if (ssh->version == 1) {
7805 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7806 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7807 } else {
ff3187f6 7808 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7809 ssh2_pkt_addstring_start(pktout);
590f6a5f 7810 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7811 }
9442dd57 7812 } else if (code == TS_REKEY) {
7813 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 7814 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 7815 }
125105d1 7816 } else if (code == TS_BRK) {
7817 if (ssh->state == SSH_STATE_CLOSED
7818 || ssh->state == SSH_STATE_PREPACKET) return;
7819 if (ssh->version == 1) {
7820 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7821 } else if (ssh->mainchan) {
ff3187f6 7822 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7823 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7824 ssh2_pkt_addstring(pktout, "break");
7825 ssh2_pkt_addbool(pktout, 0);
7826 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7827 ssh2_pkt_send(ssh, pktout);
125105d1 7828 }
6abbf9e3 7829 } else {
6f2d0cde 7830 /* Is is a POSIX signal? */
7831 char *signame = NULL;
7832 if (code == TS_SIGABRT) signame = "ABRT";
7833 if (code == TS_SIGALRM) signame = "ALRM";
7834 if (code == TS_SIGFPE) signame = "FPE";
7835 if (code == TS_SIGHUP) signame = "HUP";
7836 if (code == TS_SIGILL) signame = "ILL";
7837 if (code == TS_SIGINT) signame = "INT";
7838 if (code == TS_SIGKILL) signame = "KILL";
7839 if (code == TS_SIGPIPE) signame = "PIPE";
7840 if (code == TS_SIGQUIT) signame = "QUIT";
7841 if (code == TS_SIGSEGV) signame = "SEGV";
7842 if (code == TS_SIGTERM) signame = "TERM";
7843 if (code == TS_SIGUSR1) signame = "USR1";
7844 if (code == TS_SIGUSR2) signame = "USR2";
7845 /* The SSH-2 protocol does in principle support arbitrary named
7846 * signals, including signame@domain, but we don't support those. */
7847 if (signame) {
7848 /* It's a signal. */
7849 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7850 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7851 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7852 ssh2_pkt_addstring(pktout, "signal");
7853 ssh2_pkt_addbool(pktout, 0);
7854 ssh2_pkt_addstring(pktout, signame);
7855 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7856 logeventf(ssh, "Sent signal SIG%s", signame);
7857 }
7858 } else {
7859 /* Never heard of it. Do nothing */
7860 }
6abbf9e3 7861 }
374330e2 7862}
7863
51470298 7864void *new_sock_channel(void *handle, Socket s)
d74d141c 7865{
51470298 7866 Ssh ssh = (Ssh) handle;
d74d141c 7867 struct ssh_channel *c;
3d88e64d 7868 c = snew(struct ssh_channel);
51470298 7869 c->ssh = ssh;
d74d141c 7870
7871 if (c) {
bc240b21 7872 c->remoteid = -1; /* to be set when open confirmed */
51470298 7873 c->localid = alloc_channel_id(ssh);
d74d141c 7874 c->closes = 0;
bc240b21 7875 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7876 c->u.pfd.s = s;
013dd8c0 7877 bufchain_init(&c->v.v2.outbuffer);
51470298 7878 add234(ssh->channels, c);
d74d141c 7879 }
7880 return c;
7881}
7882
5471d09a 7883/*
7884 * This is called when stdout/stderr (the entity to which
7885 * from_backend sends data) manages to clear some backlog.
7886 */
ae9ae89f 7887static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7888{
51470298 7889 Ssh ssh = (Ssh) handle;
7890 if (ssh->version == 1) {
7891 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7892 ssh->v1_stdout_throttling = 0;
7893 ssh1_throttle(ssh, -1);
5471d09a 7894 }
7895 } else {
51470298 7896 if (ssh->mainchan && ssh->mainchan->closes == 0)
7897 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7898 }
7899}
7900
6b78788a 7901void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7902{
7903 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7904 Ssh ssh = c->ssh;
ff3187f6 7905 struct Packet *pktout;
d74d141c 7906
57356d63 7907 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7908
51470298 7909 if (ssh->version == 1) {
7910 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7911 PKT_INT, c->localid,
7912 PKT_STR, hostname,
7913 PKT_INT, port,
31fb1866 7914 /* PKT_STR, <org:orgport>, */
bc240b21 7915 PKT_END);
7916 } else {
ff3187f6 7917 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7918 ssh2_pkt_addstring(pktout, "direct-tcpip");
7919 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7920 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7921 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7922 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7923 ssh2_pkt_addstring(pktout, hostname);
7924 ssh2_pkt_adduint32(pktout, port);
bc240b21 7925 /*
7926 * We make up values for the originator data; partly it's
7927 * too much hassle to keep track, and partly I'm not
7928 * convinced the server should be told details like that
7929 * about my local network configuration.
7930 */
ff3187f6 7931 ssh2_pkt_addstring(pktout, "client-side-connection");
7932 ssh2_pkt_adduint32(pktout, 0);
7933 ssh2_pkt_send(ssh, pktout);
bc240b21 7934 }
d74d141c 7935}
7936
51470298 7937static Socket ssh_socket(void *handle)
32874aea 7938{
51470298 7939 Ssh ssh = (Ssh) handle;
7940 return ssh->s;
32874aea 7941}
8ccc75b0 7942
51470298 7943static int ssh_sendok(void *handle)
32874aea 7944{
51470298 7945 Ssh ssh = (Ssh) handle;
7946 return ssh->send_ok;
32874aea 7947}
fb09bf1c 7948
51470298 7949static int ssh_ldisc(void *handle, int option)
32874aea 7950{
51470298 7951 Ssh ssh = (Ssh) handle;
32874aea 7952 if (option == LD_ECHO)
51470298 7953 return ssh->echoing;
32874aea 7954 if (option == LD_EDIT)
51470298 7955 return ssh->editing;
0965bee0 7956 return FALSE;
7957}
7958
b9d7bcad 7959static void ssh_provide_ldisc(void *handle, void *ldisc)
7960{
7961 Ssh ssh = (Ssh) handle;
7962 ssh->ldisc = ldisc;
7963}
7964
a8327734 7965static void ssh_provide_logctx(void *handle, void *logctx)
7966{
7967 Ssh ssh = (Ssh) handle;
7968 ssh->logctx = logctx;
7969}
7970
51470298 7971static int ssh_return_exitcode(void *handle)
7972{
7973 Ssh ssh = (Ssh) handle;
3bb2f322 7974 if (ssh->s != NULL)
7975 return -1;
7976 else
7977 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7978}
7979
7980/*
f89c3294 7981 * cfg_info for SSH is the currently running version of the
7982 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
7983 */
7984static int ssh_cfg_info(void *handle)
7985{
7986 Ssh ssh = (Ssh) handle;
7987 return ssh->version;
7988}
7989
7990/*
51470298 7991 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7992 * that fails. This variable is the means by which scp.c can reach
7993 * into the SSH code and find out which one it got.
7994 */
7995extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7996{
51470298 7997 Ssh ssh = (Ssh) handle;
7998 return ssh->fallback_cmd;
d8d6c7e5 7999}
8000
374330e2 8001Backend ssh_backend = {
8002 ssh_init,
fabd1805 8003 ssh_free,
86916870 8004 ssh_reconfig,
374330e2 8005 ssh_send,
5471d09a 8006 ssh_sendbuffer,
374330e2 8007 ssh_size,
4017be6d 8008 ssh_special,
125105d1 8009 ssh_get_specials,
8ccc75b0 8010 ssh_socket,
d8d6c7e5 8011 ssh_return_exitcode,
97db3be4 8012 ssh_sendok,
0965bee0 8013 ssh_ldisc,
b9d7bcad 8014 ssh_provide_ldisc,
a8327734 8015 ssh_provide_logctx,
5471d09a 8016 ssh_unthrottle,
f89c3294 8017 ssh_cfg_info,
97db3be4 8018 22
bc240b21 8019};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator