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sk_namelookup() on Unix was failing to translate from our platform-
[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
83e7d008 166/* 64 was BUG_SSH2_DH_GEX, now spare */
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)
9442dd57 1742 do_ssh2_transport(ssh, "Initiating key re-exchange "
1743 "(too much data sent)", -1, NULL);
1744
ff3187f6 1745 ssh_free_packet(pkt);
b185170a 1746}
1747
1748/*
590f6a5f 1749 * Defer an SSH2 packet.
b185170a 1750 */
590f6a5f 1751static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1752{
ff3187f6 1753 int len = ssh2_pkt_construct(ssh, pkt);
51470298 1754 if (ssh->deferred_len + len > ssh->deferred_size) {
1755 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1756 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1757 ssh->deferred_size,
1758 unsigned char);
b185170a 1759 }
ff3187f6 1760 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1761 ssh->deferred_len += len;
9442dd57 1762 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1763 ssh_free_packet(pkt);
b185170a 1764}
1765
1766/*
590f6a5f 1767 * Queue an SSH2 packet.
1768 */
1769static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1770{
1771 assert(ssh->queueing);
1772
1773 if (ssh->queuelen >= ssh->queuesize) {
1774 ssh->queuesize = ssh->queuelen + 32;
1775 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1776 }
1777
1778 ssh->queue[ssh->queuelen++] = pkt;
1779}
1780
1781/*
1782 * Either queue or send a packet, depending on whether queueing is
1783 * set.
1784 */
1785static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1786{
1787 if (ssh->queueing)
1788 ssh2_pkt_queue(ssh, pkt);
1789 else
1790 ssh2_pkt_send_noqueue(ssh, pkt);
1791}
1792
1793/*
1794 * Either queue or defer a packet, depending on whether queueing is
1795 * set.
1796 */
1797static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1798{
1799 if (ssh->queueing)
1800 ssh2_pkt_queue(ssh, pkt);
1801 else
1802 ssh2_pkt_defer_noqueue(ssh, pkt);
1803}
1804
1805/*
b185170a 1806 * Send the whole deferred data block constructed by
39065bed 1807 * ssh2_pkt_defer() or SSH1's defer_packet().
590f6a5f 1808 *
1809 * The expected use of the defer mechanism is that you call
1810 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1811 * not currently queueing, this simply sets up deferred_send_data
1812 * and then sends it. If we _are_ currently queueing, the calls to
1813 * ssh2_pkt_defer() put the deferred packets on to the queue
1814 * instead, and therefore ssh_pkt_defersend() has no deferred data
1815 * to send. Hence, there's no need to make it conditional on
1816 * ssh->queueing.
b185170a 1817 */
51470298 1818static void ssh_pkt_defersend(Ssh ssh)
32874aea 1819{
5471d09a 1820 int backlog;
d8baa528 1821 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1822 ssh->deferred_len);
51470298 1823 ssh->deferred_len = ssh->deferred_size = 0;
1824 sfree(ssh->deferred_send_data);
1825 ssh->deferred_send_data = NULL;
5471d09a 1826 if (backlog > SSH_MAX_BACKLOG)
51470298 1827 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1828
1829 ssh->outgoing_data_size += ssh->deferred_data_size;
1830 if (!ssh->kex_in_progress &&
d57f70af 1831 ssh->max_data_size != 0 &&
1832 ssh->outgoing_data_size > ssh->max_data_size)
9442dd57 1833 do_ssh2_transport(ssh, "Initiating key re-exchange "
1834 "(too much data sent)", -1, NULL);
1835 ssh->deferred_data_size = 0;
7cca0d81 1836}
1837
590f6a5f 1838/*
1839 * Send all queued SSH2 packets. We send them by means of
1840 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1841 * packets that needed to be lumped together.
1842 */
1843static void ssh2_pkt_queuesend(Ssh ssh)
1844{
1845 int i;
1846
1847 assert(!ssh->queueing);
1848
1849 for (i = 0; i < ssh->queuelen; i++)
1850 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1851 ssh->queuelen = 0;
1852
1853 ssh_pkt_defersend(ssh);
1854}
1855
7cca0d81 1856#if 0
32874aea 1857void bndebug(char *string, Bignum b)
1858{
7cca0d81 1859 unsigned char *p;
1860 int i, len;
1861 p = ssh2_mpint_fmt(b, &len);
1862 debug(("%s", string));
1863 for (i = 0; i < len; i++)
32874aea 1864 debug((" %02x", p[i]));
765c4200 1865 debug(("\n"));
dcbde236 1866 sfree(p);
7cca0d81 1867}
1868#endif
1869
32874aea 1870static void sha_mpint(SHA_State * s, Bignum b)
1871{
7cca0d81 1872 unsigned char *p;
1873 int len;
1874 p = ssh2_mpint_fmt(b, &len);
1875 sha_string(s, p, len);
dcbde236 1876 sfree(p);
7cca0d81 1877}
1878
1879/*
0016d70b 1880 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1881 */
ff3187f6 1882static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1883{
7cca0d81 1884 unsigned long value;
ff3187f6 1885 if (pkt->length - pkt->savedpos < 4)
32874aea 1886 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1887 value = GET_32BIT(pkt->body + pkt->savedpos);
1888 pkt->savedpos += 4;
7cca0d81 1889 return value;
1890}
ff3187f6 1891static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1892{
65a22376 1893 unsigned long value;
ff3187f6 1894 if (pkt->length - pkt->savedpos < 1)
32874aea 1895 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1896 value = pkt->body[pkt->savedpos] != 0;
1897 pkt->savedpos++;
65a22376 1898 return value;
1899}
ff3187f6 1900static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 1901{
57356d63 1902 int len;
7cca0d81 1903 *p = NULL;
45068b27 1904 *length = 0;
ff3187f6 1905 if (pkt->length - pkt->savedpos < 4)
32874aea 1906 return;
ff3187f6 1907 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 1908 if (len < 0)
1909 return;
1910 *length = len;
ff3187f6 1911 pkt->savedpos += 4;
1912 if (pkt->length - pkt->savedpos < *length)
32874aea 1913 return;
ff3187f6 1914 *p = (char *)(pkt->body + pkt->savedpos);
1915 pkt->savedpos += *length;
7cca0d81 1916}
ff3187f6 1917static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 1918{
ff3187f6 1919 if (pkt->length - pkt->savedpos < length)
0016d70b 1920 return NULL;
ff3187f6 1921 pkt->savedpos += length;
1922 return pkt->body + (pkt->savedpos - length);
0016d70b 1923}
ff3187f6 1924static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 1925 unsigned char **keystr)
1926{
1927 int j;
1928
ff3187f6 1929 j = makekey(pkt->body + pkt->savedpos,
1930 pkt->length - pkt->savedpos,
0016d70b 1931 key, keystr, 0);
1932
1933 if (j < 0)
1934 return FALSE;
1935
ff3187f6 1936 pkt->savedpos += j;
1937 assert(pkt->savedpos < pkt->length);
0016d70b 1938
1939 return TRUE;
1940}
ff3187f6 1941static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 1942{
1943 int j;
1944 Bignum b;
1945
ff3187f6 1946 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1947 pkt->length - pkt->savedpos, &b);
0016d70b 1948
1949 if (j < 0)
1950 return NULL;
1951
ff3187f6 1952 pkt->savedpos += j;
0016d70b 1953 return b;
1954}
ff3187f6 1955static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 1956{
7cca0d81 1957 char *p;
3709bfe9 1958 int length;
7cca0d81 1959 Bignum b;
1960
ff3187f6 1961 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 1962 if (!p)
32874aea 1963 return NULL;
ff3187f6 1964 if (p[0] & 0x80)
32874aea 1965 return NULL;
d8baa528 1966 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1967 return b;
1968}
1969
7d503c31 1970/*
1dd353b5 1971 * Helper function to add an SSH2 signature blob to a packet.
1972 * Expects to be shown the public key blob as well as the signature
1973 * blob. Normally works just like ssh2_pkt_addstring, but will
1974 * fiddle with the signature packet if necessary for
1975 * BUG_SSH2_RSA_PADDING.
1976 */
ff3187f6 1977static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1978 void *pkblob_v, int pkblob_len,
1dd353b5 1979 void *sigblob_v, int sigblob_len)
1980{
1981 unsigned char *pkblob = (unsigned char *)pkblob_v;
1982 unsigned char *sigblob = (unsigned char *)sigblob_v;
1983
1984 /* dmemdump(pkblob, pkblob_len); */
1985 /* dmemdump(sigblob, sigblob_len); */
1986
1987 /*
1988 * See if this is in fact an ssh-rsa signature and a buggy
1989 * server; otherwise we can just do this the easy way.
1990 */
51470298 1991 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1992 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1993 int pos, len, siglen;
1994
1995 /*
1996 * Find the byte length of the modulus.
1997 */
1998
1999 pos = 4+7; /* skip over "ssh-rsa" */
2000 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2001 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2002 pos += 4; /* find modulus itself */
2003 while (len > 0 && pkblob[pos] == 0)
2004 len--, pos++;
2005 /* debug(("modulus length is %d\n", len)); */
2006
2007 /*
2008 * Now find the signature integer.
2009 */
2010 pos = 4+7; /* skip over "ssh-rsa" */
2011 siglen = GET_32BIT(sigblob+pos);
2012 /* debug(("signature length is %d\n", siglen)); */
2013
2014 if (len != siglen) {
2015 unsigned char newlen[4];
ff3187f6 2016 ssh2_pkt_addstring_start(pkt);
2017 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2018 /* dmemdump(sigblob, pos); */
2019 pos += 4; /* point to start of actual sig */
2020 PUT_32BIT(newlen, len);
ff3187f6 2021 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2022 /* dmemdump(newlen, 4); */
2023 newlen[0] = 0;
2024 while (len-- > siglen) {
ff3187f6 2025 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2026 /* dmemdump(newlen, 1); */
2027 }
ff3187f6 2028 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2029 /* dmemdump(sigblob+pos, siglen); */
2030 return;
2031 }
2032
2033 /* Otherwise fall through and do it the easy way. */
2034 }
2035
ff3187f6 2036 ssh2_pkt_addstring_start(pkt);
2037 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2038}
2039
2040/*
7d503c31 2041 * Examine the remote side's version string and compare it against
2042 * a list of known buggy implementations.
2043 */
51470298 2044static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2045{
2046 char *imp; /* pointer to implementation part */
7d503c31 2047 imp = vstring;
2048 imp += strcspn(imp, "-");
bd358db1 2049 if (*imp) imp++;
7d503c31 2050 imp += strcspn(imp, "-");
bd358db1 2051 if (*imp) imp++;
7d503c31 2052
51470298 2053 ssh->remote_bugs = 0;
7d503c31 2054
5ecd7ad0 2055 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2056 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 2057 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2058 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2059 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2060 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2061 /*
2062 * These versions don't support SSH1_MSG_IGNORE, so we have
2063 * to use a different defence against password length
2064 * sniffing.
2065 */
51470298 2066 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 2067 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 2068 }
2069
5ecd7ad0 2070 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2071 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 2072 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2073 /*
2074 * These versions need a plain password sent; they can't
2075 * handle having a null and a random length of data after
2076 * the password.
2077 */
51470298 2078 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 2079 logevent("We believe remote version needs a plain SSH1 password");
2080 }
2081
5ecd7ad0 2082 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2083 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2084 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2085 /*
2086 * These versions apparently have no clue whatever about
2087 * RSA authentication and will panic and die if they see
2088 * an AUTH_RSA message.
2089 */
51470298 2090 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 2091 logevent("We believe remote version can't handle RSA authentication");
2092 }
2093
5ecd7ad0 2094 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2095 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2096 !wc_match("* VShell", imp) &&
831301f6 2097 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2098 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2099 wc_match("2.1 *", imp)))) {
32874aea 2100 /*
2101 * These versions have the HMAC bug.
2102 */
51470298 2103 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2104 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2105 }
1dd353b5 2106
5ecd7ad0 2107 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2108 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2109 !wc_match("* VShell", imp) &&
2856a1b9 2110 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2111 /*
2112 * These versions have the key-derivation bug (failing to
2113 * include the literal shared secret in the hashes that
2114 * generate the keys).
2115 */
51470298 2116 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2117 logevent("We believe remote version has SSH2 key-derivation bug");
2118 }
2119
5ecd7ad0 2120 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2121 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2122 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2123 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2124 /*
2125 * These versions have the SSH2 RSA padding bug.
2126 */
51470298 2127 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2128 logevent("We believe remote version has SSH2 RSA padding bug");
2129 }
8e975795 2130
dda87a28 2131 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2132 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2133 wc_match("OpenSSH_2.[0-2]*", imp))) {
2134 /*
2135 * These versions have the SSH2 session-ID bug in
2136 * public-key authentication.
2137 */
2138 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2139 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2140 }
7d503c31 2141}
2142
d38d6a1f 2143/*
2144 * The `software version' part of an SSH version string is required
2145 * to contain no spaces or minus signs.
2146 */
2147static void ssh_fix_verstring(char *str)
2148{
2149 /* Eat "SSH-<protoversion>-". */
2150 assert(*str == 'S'); str++;
2151 assert(*str == 'S'); str++;
2152 assert(*str == 'H'); str++;
2153 assert(*str == '-'); str++;
2154 while (*str && *str != '-') str++;
2155 assert(*str == '-'); str++;
2156
2157 /* Convert minus signs and spaces in the remaining string into
2158 * underscores. */
2159 while (*str) {
2160 if (*str == '-' || *str == ' ')
2161 *str = '_';
2162 str++;
2163 }
2164}
2165
51470298 2166static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2167{
51470298 2168 struct do_ssh_init_state {
2169 int vslen;
2170 char version[10];
2171 char *vstring;
2172 int vstrsize;
2173 int i;
2174 int proto1, proto2;
2175 };
2176 crState(do_ssh_init_state);
374330e2 2177
51470298 2178 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2179
2180 /* Search for the string "SSH-" in the input. */
51470298 2181 s->i = 0;
8df7a775 2182 while (1) {
2183 static const int transS[] = { 1, 2, 2, 1 };
2184 static const int transH[] = { 0, 0, 3, 0 };
2185 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2186 if (c == 'S')
51470298 2187 s->i = transS[s->i];
32874aea 2188 else if (c == 'H')
51470298 2189 s->i = transH[s->i];
32874aea 2190 else if (c == '-')
51470298 2191 s->i = transminus[s->i];
32874aea 2192 else
51470298 2193 s->i = 0;
2194 if (s->i < 0)
8df7a775 2195 break;
2196 crReturn(1); /* get another character */
374330e2 2197 }
8df7a775 2198
51470298 2199 s->vstrsize = 16;
3d88e64d 2200 s->vstring = snewn(s->vstrsize, char);
51470298 2201 strcpy(s->vstring, "SSH-");
2202 s->vslen = 4;
2203 s->i = 0;
374330e2 2204 while (1) {
8df7a775 2205 crReturn(1); /* get another char */
51470298 2206 if (s->vslen >= s->vstrsize - 1) {
2207 s->vstrsize += 16;
3d88e64d 2208 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2209 }
51470298 2210 s->vstring[s->vslen++] = c;
2211 if (s->i >= 0) {
374330e2 2212 if (c == '-') {
51470298 2213 s->version[s->i] = '\0';
2214 s->i = -1;
2215 } else if (s->i < sizeof(s->version) - 1)
2216 s->version[s->i++] = c;
c4ffc4d0 2217 } else if (c == '\012')
374330e2 2218 break;
2219 }
2220
51470298 2221 ssh->agentfwd_enabled = FALSE;
2222 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2223
51470298 2224 s->vstring[s->vslen] = 0;
a7d4653a 2225 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
51470298 2226 {
2227 char *vlog;
3d88e64d 2228 vlog = snewn(20 + s->vslen, char);
51470298 2229 sprintf(vlog, "Server version: %s", s->vstring);
2230 logevent(vlog);
2231 sfree(vlog);
2232 }
2233 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2234
adf799dd 2235 /*
38d228a2 2236 * Decide which SSH protocol version to support.
adf799dd 2237 */
38d228a2 2238
2239 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2240 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2241 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2242 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2243
86916870 2244 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2245 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2246 crStop(0);
38d228a2 2247 }
86916870 2248 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2249 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2250 crStop(0);
38d228a2 2251 }
2252
d38d6a1f 2253 {
2254 char *verstring;
2255
2256 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2257 /*
2258 * Construct a v2 version string.
2259 */
a7d4653a 2260 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
d38d6a1f 2261 ssh->version = 2;
2262 } else {
2263 /*
2264 * Construct a v1 version string.
2265 */
a7d4653a 2266 verstring = dupprintf("SSH-%s-%s\012",
d38d6a1f 2267 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2268 s->version : "1.5"),
2269 sshver);
2270 ssh->version = 1;
2271 }
2272
2273 ssh_fix_verstring(verstring);
2274
2275 if (ssh->version == 2) {
2276 /*
2277 * Hash our version string and their version string.
2278 */
2279 SHA_Init(&ssh->exhashbase);
0b351b6b 2280 sha_string(&ssh->exhashbase, verstring,
a7d4653a 2281 strcspn(verstring, "\015\012"));
0b351b6b 2282 sha_string(&ssh->exhashbase, s->vstring,
a7d4653a 2283 strcspn(s->vstring, "\015\012"));
d38d6a1f 2284
2285 /*
2286 * Initialise SSHv2 protocol.
2287 */
2288 ssh->protocol = ssh2_protocol;
2289 ssh2_protocol_setup(ssh);
2290 ssh->s_rdpkt = ssh2_rdpkt;
2291 } else {
2292 /*
2293 * Initialise SSHv1 protocol.
2294 */
2295 ssh->protocol = ssh1_protocol;
2296 ssh1_protocol_setup(ssh);
2297 ssh->s_rdpkt = ssh1_rdpkt;
2298 }
2299 logeventf(ssh, "We claim version: %.*s",
a7d4653a 2300 strcspn(verstring, "\015\012"), verstring);
51470298 2301 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2302 sfree(verstring);
e5574168 2303 }
d38d6a1f 2304
2305 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2306
125105d1 2307 update_specials_menu(ssh->frontend);
51470298 2308 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2309 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2310
51470298 2311 sfree(s->vstring);
50526e47 2312
8df7a775 2313 crFinish(0);
2314}
2315
51470298 2316static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2317{
51470298 2318 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2319
2320 /*
2321 * To begin with, feed the characters one by one to the
2322 * protocol initialisation / selection function do_ssh_init().
2323 * When that returns 0, we're done with the initial greeting
2324 * exchange and can move on to packet discipline.
2325 */
2326 while (1) {
51470298 2327 int ret; /* need not be kept across crReturn */
8df7a775 2328 if (datalen == 0)
2329 crReturnV; /* more data please */
51470298 2330 ret = do_ssh_init(ssh, *data);
32874aea 2331 data++;
2332 datalen--;
8df7a775 2333 if (ret == 0)
2334 break;
2335 }
2336
2337 /*
2338 * We emerge from that loop when the initial negotiation is
2339 * over and we have selected an s_rdpkt function. Now pass
2340 * everything to s_rdpkt, and then pass the resulting packets
2341 * to the proper protocol handler.
2342 */
2343 if (datalen == 0)
2344 crReturnV;
2345 while (1) {
2346 while (datalen > 0) {
ff3187f6 2347 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2348 if (pktin) {
2349 ssh->protocol(ssh, NULL, 0, pktin);
2350 ssh_free_packet(pktin);
8df7a775 2351 }
ff3187f6 2352 if (ssh->state == SSH_STATE_CLOSED)
2353 return;
8df7a775 2354 }
2355 crReturnV;
2356 }
2357 crFinishV;
2358}
2359
36f94d1f 2360static void ssh_do_close(Ssh ssh)
32874aea 2361{
36f94d1f 2362 int i;
2363 struct ssh_channel *c;
2364
51470298 2365 ssh->state = SSH_STATE_CLOSED;
2366 if (ssh->s) {
2367 sk_close(ssh->s);
2368 ssh->s = NULL;
39934deb 2369 notify_remote_exit(ssh->frontend);
f3ab576e 2370 }
36f94d1f 2371 /*
2372 * Now we must shut down any port and X forwardings going
2373 * through this connection.
2374 */
74a98066 2375 if (ssh->channels) {
2376 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2377 switch (c->type) {
2378 case CHAN_X11:
2379 x11_close(c->u.x11.s);
2380 break;
2381 case CHAN_SOCKDATA:
2382 pfd_close(c->u.pfd.s);
2383 break;
2384 }
2385 del234(ssh->channels, c);
2386 if (ssh->version == 2)
2387 bufchain_clear(&c->v.v2.outbuffer);
2388 sfree(c);
36f94d1f 2389 }
36f94d1f 2390 }
2391}
2392
cbe2d68f 2393static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2394 int calling_back)
2395{
2396 Ssh ssh = (Ssh) plug;
2397 ssh_do_close(ssh);
7e78000d 2398 if (error_msg) {
32874aea 2399 /* A socket error has occurred. */
247308b5 2400 logevent(error_msg);
971bcc0a 2401 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2402 } else {
2403 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2404 }
7e78000d 2405 return 0;
2406}
2407
32874aea 2408static int ssh_receive(Plug plug, int urgent, char *data, int len)
2409{
51470298 2410 Ssh ssh = (Ssh) plug;
d8baa528 2411 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2412 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2413 ssh_do_close(ssh);
32874aea 2414 return 0;
3257deae 2415 }
fef97f43 2416 return 1;
374330e2 2417}
2418
5471d09a 2419static void ssh_sent(Plug plug, int bufsize)
2420{
51470298 2421 Ssh ssh = (Ssh) plug;
5471d09a 2422 /*
2423 * If the send backlog on the SSH socket itself clears, we
2424 * should unthrottle the whole world if it was throttled.
2425 */
2426 if (bufsize < SSH_MAX_BACKLOG)
51470298 2427 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2428}
2429
fb09bf1c 2430/*
8df7a775 2431 * Connect to specified host and port.
2432 * Returns an error message, or NULL on success.
6e1ebb76 2433 * Also places the canonical host name into `realhost'. It must be
2434 * freed by the caller.
8df7a775 2435 */
cbe2d68f 2436static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2437 char **realhost, int nodelay, int keepalive)
8df7a775 2438{
51470298 2439 static const struct plug_function_table fn_table = {
7e78000d 2440 ssh_closing,
5471d09a 2441 ssh_receive,
2442 ssh_sent,
2443 NULL
51470298 2444 };
7e78000d 2445
8df7a775 2446 SockAddr addr;
cbe2d68f 2447 const char *err;
8df7a775 2448
3d88e64d 2449 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2450 if (!ssh->savedhost)
8df7a775 2451 fatalbox("Out of memory");
51470298 2452 strcpy(ssh->savedhost, host);
8df7a775 2453
2454 if (port < 0)
2455 port = 22; /* default ssh port */
51470298 2456 ssh->savedport = port;
8df7a775 2457
2458 /*
2459 * Try to find host.
2460 */
05581745 2461 logeventf(ssh, "Looking up host \"%s\"%s", host,
2462 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2463 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2464 addr = name_lookup(host, port, realhost, &ssh->cfg,
2465 ssh->cfg.addressfamily);
170c1e6e 2466 if ((err = sk_addr_error(addr)) != NULL) {
2467 sk_addr_free(addr);
8df7a775 2468 return err;
170c1e6e 2469 }
8df7a775 2470
8df7a775 2471 /*
2472 * Open socket.
2473 */
3ad9d396 2474 {
57356d63 2475 char addrbuf[100];
3ad9d396 2476 sk_getaddr(addr, addrbuf, 100);
57356d63 2477 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2478 }
51470298 2479 ssh->fn = &fn_table;
e8fa8f62 2480 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2481 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2482 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2483 ssh->s = NULL;
39934deb 2484 notify_remote_exit(ssh->frontend);
8df7a775 2485 return err;
67c4ba2e 2486 }
8df7a775 2487
8df7a775 2488 return NULL;
2489}
2490
2491/*
5471d09a 2492 * Throttle or unthrottle the SSH connection.
2493 */
51470298 2494static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2495{
51470298 2496 int old_count = ssh->v1_throttle_count;
2497 ssh->v1_throttle_count += adjust;
2498 assert(ssh->v1_throttle_count >= 0);
2499 if (ssh->v1_throttle_count && !old_count) {
2500 sk_set_frozen(ssh->s, 1);
2501 } else if (!ssh->v1_throttle_count && old_count) {
2502 sk_set_frozen(ssh->s, 0);
5471d09a 2503 }
2504}
2505
2506/*
2507 * Throttle or unthrottle _all_ local data streams (for when sends
2508 * on the SSH connection itself back up).
2509 */
51470298 2510static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2511{
2512 int i;
2513 struct ssh_channel *c;
2514
51470298 2515 if (enable == ssh->throttled_all)
5471d09a 2516 return;
51470298 2517 ssh->throttled_all = enable;
2518 ssh->overall_bufsize = bufsize;
2519 if (!ssh->channels)
5471d09a 2520 return;
51470298 2521 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2522 switch (c->type) {
2523 case CHAN_MAINSESSION:
2524 /*
2525 * This is treated separately, outside the switch.
2526 */
2527 break;
2528 case CHAN_X11:
2529 x11_override_throttle(c->u.x11.s, enable);
2530 break;
2531 case CHAN_AGENT:
2532 /* Agent channels require no buffer management. */
2533 break;
2534 case CHAN_SOCKDATA:
36f94d1f 2535 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2536 break;
2537 }
2538 }
2539}
2540
2541/*
51470298 2542 * Username and password input, abstracted off into routines
2543 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2544 */
0405e71f 2545
2546/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2547static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2548{
51470298 2549 ssh->userpass_input_buffer = buffer;
2550 ssh->userpass_input_buflen = buflen;
2551 ssh->userpass_input_bufpos = 0;
2552 ssh->userpass_input_echo = echo;
0405e71f 2553}
2554
2555/*
2556 * Process some terminal data in the course of username/password
2557 * input. Returns >0 for success (line of input returned in
2558 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2559 * for inconclusive (keep waiting for more input please).
2560 */
ae9ae89f 2561static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2562{
2563 char c;
2564
2565 while (inlen--) {
2566 switch (c = *in++) {
2567 case 10:
2568 case 13:
51470298 2569 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2570 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2571 return +1;
2572 break;
2573 case 8:
2574 case 127:
51470298 2575 if (ssh->userpass_input_bufpos > 0) {
2576 if (ssh->userpass_input_echo)
2577 c_write_str(ssh, "\b \b");
2578 ssh->userpass_input_bufpos--;
0405e71f 2579 }
2580 break;
2581 case 21:
2582 case 27:
51470298 2583 while (ssh->userpass_input_bufpos > 0) {
2584 if (ssh->userpass_input_echo)
2585 c_write_str(ssh, "\b \b");
2586 ssh->userpass_input_bufpos--;
0405e71f 2587 }
2588 break;
2589 case 3:
2590 case 4:
2591 return -1;
2592 break;
2593 default:
4692a14a 2594 /*
2595 * This simplistic check for printability is disabled
2596 * when we're doing password input, because some people
2597 * have control characters in their passwords.o
2598 */
2599 if ((!ssh->userpass_input_echo ||
2600 (c >= ' ' && c <= '~') ||
0405e71f 2601 ((unsigned char) c >= 160))
51470298 2602 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2603 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2604 if (ssh->userpass_input_echo)
2605 c_write(ssh, &c, 1);
0405e71f 2606 }
2607 break;
2608 }
2609 }
2610 return 0;
2611}
2612
f11d78f2 2613static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2614{
2615 Ssh ssh = (Ssh) sshv;
2616
2617 ssh->agent_response = reply;
2618 ssh->agent_response_len = replylen;
2619
2620 if (ssh->version == 1)
ff3187f6 2621 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2622 else
ff3187f6 2623 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2624}
2625
f11d78f2 2626static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2627{
2628 struct ssh_channel *c = (struct ssh_channel *)cv;
2629 Ssh ssh = c->ssh;
2630 void *sentreply = reply;
2631
2632 if (!sentreply) {
2633 /* Fake SSH_AGENT_FAILURE. */
2634 sentreply = "\0\0\0\1\5";
2635 replylen = 5;
2636 }
2637 if (ssh->version == 2) {
2638 ssh2_add_channel_data(c, sentreply, replylen);
2639 ssh2_try_send(c);
2640 } else {
2641 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2642 PKT_INT, c->remoteid,
9a10ecf4 2643 PKTT_DATA,
839f10db 2644 PKT_INT, replylen,
2645 PKT_DATA, sentreply, replylen,
9a10ecf4 2646 PKTT_OTHER,
839f10db 2647 PKT_END);
2648 }
2649 if (reply)
2650 sfree(reply);
2651}
2652
0405e71f 2653/*
fb09bf1c 2654 * Handle the key exchange and user authentication phases.
2655 */
ff3187f6 2656static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2657 struct Packet *pktin)
fb09bf1c 2658{
0016d70b 2659 int i, j, ret;
2660 unsigned char cookie[8], *ptr;
374330e2 2661 struct RSAKey servkey, hostkey;
2662 struct MD5Context md5c;
51470298 2663 struct do_ssh1_login_state {
2664 int len;
2665 unsigned char *rsabuf, *keystr1, *keystr2;
2666 unsigned long supported_ciphers_mask, supported_auths_mask;
2667 int tried_publickey, tried_agent;
2668 int tis_auth_refused, ccard_auth_refused;
2669 unsigned char session_id[16];
2670 int cipher_type;
2671 char username[100];
2672 void *publickey_blob;
2673 int publickey_bloblen;
2674 char password[100];
2675 char prompt[200];
2676 int pos;
2677 char c;
2678 int pwpkt_type;
2679 unsigned char request[5], *response, *p;
2680 int responselen;
2681 int keyi, nkeys;
2682 int authed;
2683 struct RSAKey key;
2684 Bignum challenge;
2685 char *commentp;
2686 int commentlen;
2687 };
2688 crState(do_ssh1_login_state);
2689
2690 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2691
ff3187f6 2692 if (!pktin)
2693 crWaitUntil(pktin);
374330e2 2694
ff3187f6 2695 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2696 bombout(("Public key packet not received"));
7ffdbc1a 2697 crStop(0);
8d5de777 2698 }
374330e2 2699
c5e9c988 2700 logevent("Received public keys");
374330e2 2701
ff3187f6 2702 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2703 if (!ptr) {
2704 bombout(("SSH1 public key packet stopped before random cookie"));
2705 crStop(0);
2706 }
2707 memcpy(cookie, ptr, 8);
374330e2 2708
ff3187f6 2709 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2710 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2711 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2712 crStop(0);
2713 }
374330e2 2714
c5e9c988 2715 /*
1c2a93c4 2716 * Log the host key fingerprint.
c5e9c988 2717 */
c5e9c988 2718 {
2719 char logmsg[80];
1c2a93c4 2720 logevent("Host key fingerprint is:");
c5e9c988 2721 strcpy(logmsg, " ");
32874aea 2722 hostkey.comment = NULL;
2723 rsa_fingerprint(logmsg + strlen(logmsg),
2724 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2725 logevent(logmsg);
2726 }
2727
ff3187f6 2728 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2729 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2730 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2731
51470298 2732 ssh->v1_local_protoflags =
2733 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2734 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2735
c5e9c988 2736 MD5Init(&md5c);
51470298 2737 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2738 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2739 MD5Update(&md5c, cookie, 8);
51470298 2740 MD5Final(s->session_id, &md5c);
374330e2 2741
32874aea 2742 for (i = 0; i < 32; i++)
51470298 2743 ssh->session_key[i] = random_byte();
374330e2 2744
0016d70b 2745 /*
2746 * Verify that the `bits' and `bytes' parameters match.
2747 */
2748 if (hostkey.bits > hostkey.bytes * 8 ||
2749 servkey.bits > servkey.bytes * 8) {
2750 bombout(("SSH1 public keys were badly formatted"));
2751 crStop(0);
2752 }
2753
51470298 2754 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2755
3d88e64d 2756 s->rsabuf = snewn(s->len, unsigned char);
51470298 2757 if (!s->rsabuf)
374330e2 2758 fatalbox("Out of memory");
2759
89ee5268 2760 /*
2761 * Verify the host key.
2762 */
2763 {
32874aea 2764 /*
2765 * First format the key into a string.
2766 */
2767 int len = rsastr_len(&hostkey);
2768 char fingerprint[100];
3d88e64d 2769 char *keystr = snewn(len, char);
32874aea 2770 if (!keystr)
2771 fatalbox("Out of memory");
2772 rsastr_fmt(keystr, &hostkey);
2773 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2774 verify_ssh_host_key(ssh->frontend,
2775 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2776 fingerprint);
2777 sfree(keystr);
2778 }
2779
2780 for (i = 0; i < 32; i++) {
51470298 2781 s->rsabuf[i] = ssh->session_key[i];
374330e2 2782 if (i < 16)
51470298 2783 s->rsabuf[i] ^= s->session_id[i];
374330e2 2784 }
2785
2786 if (hostkey.bytes > servkey.bytes) {
0016d70b 2787 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2788 if (ret)
2789 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2790 } else {
0016d70b 2791 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2792 if (ret)
2793 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2794 }
2795 if (!ret) {
2796 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2797 crStop(0);
374330e2 2798 }
2799
c5e9c988 2800 logevent("Encrypted session key");
2801
ca20bfcf 2802 {
2803 int cipher_chosen = 0, warn = 0;
2804 char *cipher_string = NULL;
51470298 2805 int i;
ca20bfcf 2806 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2807 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2808 if (next_cipher == CIPHER_WARN) {
2809 /* If/when we choose a cipher, warn about it */
2810 warn = 1;
2811 } else if (next_cipher == CIPHER_AES) {
2812 /* XXX Probably don't need to mention this. */
2813 logevent("AES not supported in SSH1, skipping");
2814 } else {
2815 switch (next_cipher) {
51470298 2816 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2817 cipher_string = "3DES"; break;
51470298 2818 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2819 cipher_string = "Blowfish"; break;
51470298 2820 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2821 cipher_string = "single-DES"; break;
2822 }
51470298 2823 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2824 cipher_chosen = 1;
2825 }
2826 }
2827 if (!cipher_chosen) {
51470298 2828 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2829 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2830 "supporting 3DES encryption"));
2831 else
2832 /* shouldn't happen */
6b5cf8b4 2833 bombout(("No supported ciphers found"));
7ffdbc1a 2834 crStop(0);
a99a05c0 2835 }
ca20bfcf 2836
2837 /* Warn about chosen cipher if necessary. */
bb348ab1 2838 if (warn) {
2839 sk_set_frozen(ssh->s, 1);
83e7d008 2840 askalg(ssh->frontend, "cipher", cipher_string);
bb348ab1 2841 sk_set_frozen(ssh->s, 0);
2842 }
bea1ef5f 2843 }
ca20bfcf 2844
51470298 2845 switch (s->cipher_type) {
32874aea 2846 case SSH_CIPHER_3DES:
2847 logevent("Using 3DES encryption");
2848 break;
2849 case SSH_CIPHER_DES:
2850 logevent("Using single-DES encryption");
2851 break;
2852 case SSH_CIPHER_BLOWFISH:
2853 logevent("Using Blowfish encryption");
2854 break;
c5e9c988 2855 }
bea1ef5f 2856
51470298 2857 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2858 PKT_CHAR, s->cipher_type,
32874aea 2859 PKT_DATA, cookie, 8,
51470298 2860 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2861 PKT_DATA, s->rsabuf, s->len,
2862 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2863
c5e9c988 2864 logevent("Trying to enable encryption...");
374330e2 2865
51470298 2866 sfree(s->rsabuf);
374330e2 2867
51470298 2868 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2869 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2870 &ssh_3des);
371e569c 2871 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2872 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2873 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2874
0183b242 2875 ssh->crcda_ctx = crcda_make_context();
2876 logevent("Installing CRC compensation attack detector");
2877
679539d7 2878 if (servkey.modulus) {
2879 sfree(servkey.modulus);
2880 servkey.modulus = NULL;
2881 }
2882 if (servkey.exponent) {
2883 sfree(servkey.exponent);
2884 servkey.exponent = NULL;
2885 }
2886 if (hostkey.modulus) {
2887 sfree(hostkey.modulus);
2888 hostkey.modulus = NULL;
2889 }
2890 if (hostkey.exponent) {
2891 sfree(hostkey.exponent);
2892 hostkey.exponent = NULL;
2893 }
ff3187f6 2894 crWaitUntil(pktin);
374330e2 2895
ff3187f6 2896 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2897 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2898 crStop(0);
8d5de777 2899 }
374330e2 2900
c5e9c988 2901 logevent("Successfully started encryption");
2902
374330e2 2903 fflush(stdout);
2904 {
aa09f7d0 2905 if (!*ssh->cfg.username) {
c0a81592 2906 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2907 if (!ssh_get_line("login as: ",
51470298 2908 s->username, sizeof(s->username), FALSE)) {
32874aea 2909 /*
2910 * get_line failed to get a username.
2911 * Terminate.
2912 */
2913 logevent("No username provided. Abandoning session.");
3bb2f322 2914 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2915 crStop(1);
32874aea 2916 }
2917 } else {
51470298 2918 int ret; /* need not be kept over crReturn */
2919 c_write_str(ssh, "login as: ");
2920 ssh->send_ok = 1;
0405e71f 2921
51470298 2922 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2923 do {
ff3187f6 2924 crWaitUntil(!pktin);
51470298 2925 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2926 } while (ret == 0);
2927 if (ret < 0)
2928 cleanup_exit(0);
51470298 2929 c_write_str(ssh, "\r\n");
32874aea 2930 }
2931 } else {
86916870 2932 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2933 s->username[sizeof(s->username)-1] = '\0';
374330e2 2934 }
fb09bf1c 2935
51470298 2936 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2937 {
51470298 2938 char userlog[22 + sizeof(s->username)];
2939 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2940 logevent(userlog);
32874aea 2941 if (flags & FLAG_INTERACTIVE &&
2942 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2943 strcat(userlog, "\r\n");
51470298 2944 c_write_str(ssh, userlog);
3c8e959b 2945 }
c5e9c988 2946 }
374330e2 2947 }
2948
ff3187f6 2949 crWaitUntil(pktin);
374330e2 2950
51470298 2951 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2952 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2953 s->tried_publickey = s->tried_agent = 1;
0df73905 2954 } else {
51470298 2955 s->tried_publickey = s->tried_agent = 0;
0df73905 2956 }
51470298 2957 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2958 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2959 if (!filename_is_null(ssh->cfg.keyfile)) {
2960 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2961 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2962 s->publickey_blob = NULL;
396778f1 2963 } else
51470298 2964 s->publickey_blob = NULL;
7cca0d81 2965
ff3187f6 2966 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 2967 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2968
51470298 2969 if (agent_exists() && !s->tried_agent) {
32874aea 2970 /*
2971 * Attempt RSA authentication using Pageant.
2972 */
32874aea 2973 void *r;
2974
51470298 2975 s->authed = FALSE;
2976 s->tried_agent = 1;
32874aea 2977 logevent("Pageant is running. Requesting keys.");
2978
2979 /* Request the keys held by the agent. */
51470298 2980 PUT_32BIT(s->request, 1);
2981 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2982 if (!agent_query(s->request, 5, &r, &s->responselen,
2983 ssh_agent_callback, ssh)) {
2984 do {
2985 crReturn(0);
ff3187f6 2986 if (pktin) {
839f10db 2987 bombout(("Unexpected data from server while waiting"
2988 " for agent response"));
2989 crStop(0);
2990 }
ff3187f6 2991 } while (pktin || inlen > 0);
839f10db 2992 r = ssh->agent_response;
2993 s->responselen = ssh->agent_response_len;
2994 }
51470298 2995 s->response = (unsigned char *) r;
2996 if (s->response && s->responselen >= 5 &&
2997 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2998 s->p = s->response + 5;
2999 s->nkeys = GET_32BIT(s->p);
3000 s->p += 4;
32874aea 3001 {
3002 char buf[64];
51470298 3003 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 3004 logevent(buf);
3005 }
51470298 3006 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 3007 {
3008 char buf[64];
51470298 3009 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 3010 logevent(buf);
3011 }
51470298 3012 if (s->publickey_blob &&
3013 !memcmp(s->p, s->publickey_blob,
3014 s->publickey_bloblen)) {
396778f1 3015 logevent("This key matches configured key file");
51470298 3016 s->tried_publickey = 1;
396778f1 3017 }
51470298 3018 s->p += 4;
0016d70b 3019 {
3020 int n, ok = FALSE;
3021 do { /* do while (0) to make breaking easy */
3022 n = ssh1_read_bignum
3023 (s->p, s->responselen-(s->p-s->response),
3024 &s->key.exponent);
3025 if (n < 0)
3026 break;
3027 s->p += n;
3028 n = ssh1_read_bignum
3029 (s->p, s->responselen-(s->p-s->response),
3030 &s->key.modulus);
3031 if (n < 0)
3032 break;
3033 s->p += n;
3034 if (s->responselen - (s->p-s->response) < 4)
3035 break;
3036 s->commentlen = GET_32BIT(s->p);
3037 s->p += 4;
3038 if (s->responselen - (s->p-s->response) <
3039 s->commentlen)
3040 break;
3041 s->commentp = (char *)s->p;
3042 s->p += s->commentlen;
3043 ok = TRUE;
3044 } while (0);
3045 if (!ok) {
3046 logevent("Pageant key list packet was truncated");
3047 break;
3048 }
3049 }
51470298 3050 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3051 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3052 crWaitUntil(pktin);
3053 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3054 logevent("Key refused");
3055 continue;
3056 }
3057 logevent("Received RSA challenge");
ff3187f6 3058 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3059 bombout(("Server's RSA challenge was badly formatted"));
3060 crStop(0);
3061 }
3062
32874aea 3063 {
3064 char *agentreq, *q, *ret;
2d466ffd 3065 void *vret;
32874aea 3066 int len, retlen;
3067 len = 1 + 4; /* message type, bit count */
51470298 3068 len += ssh1_bignum_length(s->key.exponent);
3069 len += ssh1_bignum_length(s->key.modulus);
3070 len += ssh1_bignum_length(s->challenge);
32874aea 3071 len += 16; /* session id */
3072 len += 4; /* response format */
3d88e64d 3073 agentreq = snewn(4 + len, char);
32874aea 3074 PUT_32BIT(agentreq, len);
3075 q = agentreq + 4;
3076 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3077 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3078 q += 4;
51470298 3079 q += ssh1_write_bignum(q, s->key.exponent);
3080 q += ssh1_write_bignum(q, s->key.modulus);
3081 q += ssh1_write_bignum(q, s->challenge);
3082 memcpy(q, s->session_id, 16);
32874aea 3083 q += 16;
3084 PUT_32BIT(q, 1); /* response format */
839f10db 3085 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3086 ssh_agent_callback, ssh)) {
3087 sfree(agentreq);
3088 do {
3089 crReturn(0);
ff3187f6 3090 if (pktin) {
839f10db 3091 bombout(("Unexpected data from server"
3092 " while waiting for agent"
3093 " response"));
3094 crStop(0);
3095 }
ff3187f6 3096 } while (pktin || inlen > 0);
839f10db 3097 vret = ssh->agent_response;
3098 retlen = ssh->agent_response_len;
3099 } else
3100 sfree(agentreq);
2d466ffd 3101 ret = vret;
32874aea 3102 if (ret) {
3103 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3104 logevent("Sending Pageant's response");
51470298 3105 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3106 PKT_DATA, ret + 5, 16,
3107 PKT_END);
3108 sfree(ret);
ff3187f6 3109 crWaitUntil(pktin);
3110 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3111 logevent
3112 ("Pageant's response accepted");
3113 if (flags & FLAG_VERBOSE) {
51470298 3114 c_write_str(ssh, "Authenticated using"
3115 " RSA key \"");
3116 c_write(ssh, s->commentp,
3117 s->commentlen);
3118 c_write_str(ssh, "\" from agent\r\n");
32874aea 3119 }
51470298 3120 s->authed = TRUE;
32874aea 3121 } else
3122 logevent
3123 ("Pageant's response not accepted");
3124 } else {
3125 logevent
3126 ("Pageant failed to answer challenge");
3127 sfree(ret);
3128 }
3129 } else {
3130 logevent("No reply received from Pageant");
3131 }
3132 }
51470298 3133 freebn(s->key.exponent);
3134 freebn(s->key.modulus);
3135 freebn(s->challenge);
3136 if (s->authed)
32874aea 3137 break;
3138 }
29b1d0b3 3139 sfree(s->response);
32874aea 3140 }
51470298 3141 if (s->authed)
32874aea 3142 break;
3143 }
9a30e26b 3144 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3145 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3146
86916870 3147 if (ssh->cfg.try_tis_auth &&
51470298 3148 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3149 !s->tis_auth_refused) {
3150 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3151 logevent("Requested TIS authentication");
51470298 3152 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3153 crWaitUntil(pktin);
3154 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3155 logevent("TIS authentication declined");
3156 if (flags & FLAG_INTERACTIVE)
51470298 3157 c_write_str(ssh, "TIS authentication refused.\r\n");
3158 s->tis_auth_refused = 1;
614a20a0 3159 continue;
32874aea 3160 } else {
0016d70b 3161 char *challenge;
3162 int challengelen;
3163
ff3187f6 3164 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3165 if (!challenge) {
3166 bombout(("TIS challenge packet was badly formed"));
3167 crStop(0);
3168 }
32874aea 3169 logevent("Received TIS challenge");
51470298 3170 if (challengelen > sizeof(s->prompt) - 1)
3171 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3172 memcpy(s->prompt, challenge, challengelen);
614a20a0 3173 /* Prompt heuristic comes from OpenSSH */
51470298 3174 strncpy(s->prompt + challengelen,
3175 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3176 "": "\r\nResponse: ",
51470298 3177 (sizeof s->prompt) - challengelen);
3178 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3179 }
3180 }
86916870 3181 if (ssh->cfg.try_tis_auth &&
51470298 3182 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3183 !s->ccard_auth_refused) {
3184 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3185 logevent("Requested CryptoCard authentication");
51470298 3186 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3187 crWaitUntil(pktin);
3188 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3189 logevent("CryptoCard authentication declined");
51470298 3190 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3191 s->ccard_auth_refused = 1;
614a20a0 3192 continue;
32874aea 3193 } else {
0016d70b 3194 char *challenge;
3195 int challengelen;
3196
ff3187f6 3197 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3198 if (!challenge) {
3199 bombout(("CryptoCard challenge packet was badly formed"));
3200 crStop(0);
3201 }
32874aea 3202 logevent("Received CryptoCard challenge");
51470298 3203 if (challengelen > sizeof(s->prompt) - 1)
3204 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3205 memcpy(s->prompt, challenge, challengelen);
51470298 3206 strncpy(s->prompt + challengelen,
3207 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3208 "" : "\r\nResponse: ",
51470298 3209 sizeof(s->prompt) - challengelen);
3210 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3211 }
3212 }
51470298 3213 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3214 sprintf(s->prompt, "%.90s@%.90s's password: ",
3215 s->username, ssh->savedhost);
32874aea 3216 }
51470298 3217 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3218 char *comment = NULL;
231ee168 3219 int type;
3220 char msgbuf[256];
32874aea 3221 if (flags & FLAG_VERBOSE)
51470298 3222 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3223 logeventf(ssh, "Trying public key \"%s\"",
3224 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3225 type = key_type(&ssh->cfg.keyfile);
231ee168 3226 if (type != SSH_KEYTYPE_SSH1) {
3227 sprintf(msgbuf, "Key is of wrong type (%s)",
3228 key_type_to_str(type));
3229 logevent(msgbuf);
51470298 3230 c_write_str(ssh, msgbuf);
3231 c_write_str(ssh, "\r\n");
3232 s->tried_publickey = 1;
231ee168 3233 continue;
3234 }
9a30e26b 3235 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3236 if (flags & FLAG_VERBOSE)
51470298 3237 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3238 goto tryauth;
3239 }
51470298 3240 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3241 sfree(comment);
3242 }
a52f067e 3243
614a20a0 3244 /*
3245 * Show password prompt, having first obtained it via a TIS
3246 * or CryptoCard exchange if we're doing TIS or CryptoCard
3247 * authentication.
3248 */
fa17a66e 3249 if (ssh_get_line) {
51470298 3250 if (!ssh_get_line(s->prompt, s->password,
3251 sizeof(s->password), TRUE)) {
32874aea 3252 /*
3253 * get_line failed to get a password (for example
3254 * because one was supplied on the command line
3255 * which has already failed to work). Terminate.
3256 */
51470298 3257 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3258 PKT_STR, "No more passwords available to try",
3259 PKT_END);
247308b5 3260 logevent("Unable to authenticate");
a8327734 3261 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3262 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3263 crStop(1);
32874aea 3264 }
fb09bf1c 3265 } else {
614a20a0 3266 /* Prompt may have come from server. We've munged it a bit, so
3267 * we know it to be zero-terminated at least once. */
51470298 3268 int ret; /* need not be saved over crReturn */
3269 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3270 s->pos = 0;
0405e71f 3271
51470298 3272 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3273 do {
ff3187f6 3274 crWaitUntil(!pktin);
51470298 3275 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3276 } while (ret == 0);
3277 if (ret < 0)
3278 cleanup_exit(0);
51470298 3279 c_write_str(ssh, "\r\n");
32874aea 3280 }
3281
3282 tryauth:
51470298 3283 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3284 /*
3285 * Try public key authentication with the specified
3286 * key file.
3287 */
51470298 3288 s->tried_publickey = 1;
3289
3290 {
222d54dc 3291 const char *error = NULL;
3292 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3293 &error);
51470298 3294 if (ret == 0) {
3295 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3296 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3297 c_write_str(ssh, " (");
3298 c_write_str(ssh, error);
3299 c_write_str(ssh, ").\r\n");
51470298 3300 continue; /* go and try password */
3301 }
3302 if (ret == -1) {
3303 c_write_str(ssh, "Wrong passphrase.\r\n");
3304 s->tried_publickey = 0;
3305 continue; /* try again */
3306 }
32874aea 3307 }
3308
3309 /*
3310 * Send a public key attempt.
3311 */
51470298 3312 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3313 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3314
ff3187f6 3315 crWaitUntil(pktin);
3316 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3317 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3318 continue; /* go and try password */
3319 }
ff3187f6 3320 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3321 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3322 crStop(0);
32874aea 3323 }
32874aea 3324
51470298 3325 {
3326 int i;
3327 unsigned char buffer[32];
3328 Bignum challenge, response;
3329
ff3187f6 3330 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3331 bombout(("Server's RSA challenge was badly formatted"));
3332 crStop(0);
3333 }
51470298 3334 response = rsadecrypt(challenge, &s->key);
3335 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3336
51470298 3337 for (i = 0; i < 32; i++) {
3338 buffer[i] = bignum_byte(response, 31 - i);
3339 }
3340
3341 MD5Init(&md5c);
3342 MD5Update(&md5c, buffer, 32);
3343 MD5Update(&md5c, s->session_id, 16);
3344 MD5Final(buffer, &md5c);
32874aea 3345
51470298 3346 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3347 PKT_DATA, buffer, 16, PKT_END);
3348
3349 freebn(challenge);
3350 freebn(response);
3351 }
32874aea 3352
ff3187f6 3353 crWaitUntil(pktin);
3354 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3355 if (flags & FLAG_VERBOSE)
51470298 3356 c_write_str(ssh, "Failed to authenticate with"
3357 " our public key.\r\n");
32874aea 3358 continue; /* go and try password */
ff3187f6 3359 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3360 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3361 crStop(0);
32874aea 3362 }
3363
3364 break; /* we're through! */
3365 } else {
51470298 3366 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3367 /*
3368 * Defence against traffic analysis: we send a
3369 * whole bunch of packets containing strings of
3370 * different lengths. One of these strings is the
3371 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3372 * The others are all random data in
3373 * SSH1_MSG_IGNORE packets. This way a passive
3374 * listener can't tell which is the password, and
3375 * hence can't deduce the password length.
3376 *
3377 * Anybody with a password length greater than 16
3378 * bytes is going to have enough entropy in their
3379 * password that a listener won't find it _that_
3380 * much help to know how long it is. So what we'll
3381 * do is:
3382 *
3383 * - if password length < 16, we send 15 packets
3384 * containing string lengths 1 through 15
3385 *
3386 * - otherwise, we let N be the nearest multiple
3387 * of 8 below the password length, and send 8
3388 * packets containing string lengths N through
3389 * N+7. This won't obscure the order of
3390 * magnitude of the password length, but it will
3391 * introduce a bit of extra uncertainty.
3392 *
3393 * A few servers (the old 1.2.18 through 1.2.22)
3394 * can't deal with SSH1_MSG_IGNORE. For these
3395 * servers, we need an alternative defence. We make
3396 * use of the fact that the password is interpreted
3397 * as a C string: so we can append a NUL, then some
3398 * random data.
bd358db1 3399 *
3400 * One server (a Cisco one) can deal with neither
3401 * SSH1_MSG_IGNORE _nor_ a padded password string.
3402 * For this server we are left with no defences
3403 * against password length sniffing.
32874aea 3404 */
51470298 3405 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3406 /*
3407 * The server can deal with SSH1_MSG_IGNORE, so
3408 * we can use the primary defence.
3409 */
32874aea 3410 int bottom, top, pwlen, i;
3411 char *randomstr;
3412
51470298 3413 pwlen = strlen(s->password);
32874aea 3414 if (pwlen < 16) {
3415 bottom = 0; /* zero length passwords are OK! :-) */
3416 top = 15;
3417 } else {
3418 bottom = pwlen & ~7;
3419 top = bottom + 7;
3420 }
3421
3422 assert(pwlen >= bottom && pwlen <= top);
3423
3d88e64d 3424 randomstr = snewn(top + 1, char);
32874aea 3425
3426 for (i = bottom; i <= top; i++) {
9a10ecf4 3427 if (i == pwlen) {
51470298 3428 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3429 PKTT_PASSWORD, PKT_STR, s->password,
3430 PKTT_OTHER, PKT_END);
3431 } else {
32874aea 3432 for (j = 0; j < i; j++) {
3433 do {
3434 randomstr[j] = random_byte();
3435 } while (randomstr[j] == '\0');
3436 }
3437 randomstr[i] = '\0';
51470298 3438 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3439 PKT_STR, randomstr, PKT_END);
3440 }
3441 }
bd358db1 3442 logevent("Sending password with camouflage packets");
51470298 3443 ssh_pkt_defersend(ssh);
679539d7 3444 sfree(randomstr);
bd358db1 3445 }
51470298 3446 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3447 /*
3448 * The server can't deal with SSH1_MSG_IGNORE
3449 * but can deal with padded passwords, so we
3450 * can use the secondary defence.
3451 */
bd358db1 3452 char string[64];
51470298 3453 char *ss;
bd358db1 3454 int len;
3455
51470298 3456 len = strlen(s->password);
bd358db1 3457 if (len < sizeof(string)) {
51470298 3458 ss = string;
3459 strcpy(string, s->password);
bd358db1 3460 len++; /* cover the zero byte */
3461 while (len < sizeof(string)) {
3462 string[len++] = (char) random_byte();
3463 }
3464 } else {
51470298 3465 ss = s->password;
bd358db1 3466 }
3467 logevent("Sending length-padded password");
9a10ecf4 3468 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3469 PKT_INT, len, PKT_DATA, ss, len,
3470 PKTT_OTHER, PKT_END);
bd358db1 3471 } else {
3472 /*
3473 * The server has _both_
3474 * BUG_CHOKES_ON_SSH1_IGNORE and
3475 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3476 * therefore nothing we can do.
3477 */
3478 int len;
51470298 3479 len = strlen(s->password);
bd358db1 3480 logevent("Sending unpadded password");
9a10ecf4 3481 send_packet(ssh, s->pwpkt_type,
3482 PKTT_PASSWORD, PKT_INT, len,
3483 PKT_DATA, s->password, len,
3484 PKTT_OTHER, PKT_END);
32874aea 3485 }
3486 } else {
9a10ecf4 3487 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3488 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3489 }
3490 }
c5e9c988 3491 logevent("Sent password");
51470298 3492 memset(s->password, 0, strlen(s->password));
ff3187f6 3493 crWaitUntil(pktin);
3494 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3495 if (flags & FLAG_VERBOSE)
51470298 3496 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3497 logevent("Authentication refused");
ff3187f6 3498 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3499 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3500 crStop(0);
374330e2 3501 }
3502 }
3503
c5e9c988 3504 logevent("Authentication successful");
3505
fb09bf1c 3506 crFinish(1);
3507}
3508
32874aea 3509void sshfwd_close(struct ssh_channel *c)
3510{
51470298 3511 Ssh ssh = c->ssh;
3512
36f94d1f 3513 if (ssh->state != SSH_STATE_SESSION) {
3514 assert(ssh->state == SSH_STATE_CLOSED);
3515 return;
3516 }
3517
80e48603 3518 if (c && !c->closes) {
4ed34d25 3519 /*
3520 * If the channel's remoteid is -1, we have sent
3521 * CHANNEL_OPEN for this channel, but it hasn't even been
3522 * acknowledged by the server. So we must set a close flag
3523 * on it now, and then when the server acks the channel
3524 * open, we can close it then.
3525 */
36cac739 3526 if (((int)c->remoteid) != -1) {
51470298 3527 if (ssh->version == 1) {
3528 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3529 PKT_END);
3530 } else {
ff3187f6 3531 struct Packet *pktout;
3532 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3533 ssh2_pkt_adduint32(pktout, c->remoteid);
3534 ssh2_pkt_send(ssh, pktout);
4ed34d25 3535 }
32874aea 3536 }
0357890f 3537 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3538 if (c->type == CHAN_X11) {
3539 c->u.x11.s = NULL;
d74d141c 3540 logevent("Forwarded X11 connection terminated");
4ed34d25 3541 } else if (c->type == CHAN_SOCKDATA ||
3542 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3543 c->u.pfd.s = NULL;
3544 logevent("Forwarded port closed");
32874aea 3545 }
3546 }
3547}
3548
5471d09a 3549int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3550{
51470298 3551 Ssh ssh = c->ssh;
3552
36f94d1f 3553 if (ssh->state != SSH_STATE_SESSION) {
3554 assert(ssh->state == SSH_STATE_CLOSED);
3555 return 0;
3556 }
3557
51470298 3558 if (ssh->version == 1) {
3559 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3560 PKT_INT, c->remoteid,
9a10ecf4 3561 PKTT_DATA,
3562 PKT_INT, len, PKT_DATA, buf, len,
3563 PKTT_OTHER, PKT_END);
5471d09a 3564 /*
3565 * In SSH1 we can return 0 here - implying that forwarded
3566 * connections are never individually throttled - because
3567 * the only circumstance that can cause throttling will be
3568 * the whole SSH connection backing up, in which case
3569 * _everything_ will be throttled as a whole.
3570 */
3571 return 0;
783415f8 3572 } else {
32874aea 3573 ssh2_add_channel_data(c, buf, len);
5471d09a 3574 return ssh2_try_send(c);
3575 }
3576}
3577
3578void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3579{
51470298 3580 Ssh ssh = c->ssh;
3581
36f94d1f 3582 if (ssh->state != SSH_STATE_SESSION) {
3583 assert(ssh->state == SSH_STATE_CLOSED);
3584 return;
3585 }
3586
51470298 3587 if (ssh->version == 1) {
5471d09a 3588 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3589 c->v.v1.throttling = 0;
51470298 3590 ssh1_throttle(ssh, -1);
5471d09a 3591 }
3592 } else {
3593 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3594 }
9c964e85 3595}
3596
06fadff5 3597static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3598{
3599 struct queued_handler *qh = ssh->qhead;
3600
3601 assert(qh != NULL);
3602
3603 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3604
3605 if (qh->msg1 > 0) {
3606 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3607 ssh->packet_dispatch[qh->msg1] = NULL;
3608 }
3609 if (qh->msg2 > 0) {
3610 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3611 ssh->packet_dispatch[qh->msg2] = NULL;
3612 }
3613
3614 if (qh->next) {
3615 ssh->qhead = qh->next;
3616
3617 if (ssh->qhead->msg1 > 0) {
3618 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3619 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3620 }
3621 if (ssh->qhead->msg2 > 0) {
3622 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3623 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3624 }
3625 } else {
3626 ssh->qhead = ssh->qtail = NULL;
3627 ssh->packet_dispatch[pktin->type] = NULL;
3628 }
3629
3630 qh->handler(ssh, pktin, qh->ctx);
3631
3632 sfree(qh);
3633}
3634
3635static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3636 chandler_fn_t handler, void *ctx)
3637{
3638 struct queued_handler *qh;
3639
3640 qh = snew(struct queued_handler);
3641 qh->msg1 = msg1;
3642 qh->msg2 = msg2;
3643 qh->handler = handler;
3644 qh->ctx = ctx;
3645 qh->next = NULL;
3646
3647 if (ssh->qtail == NULL) {
3648 ssh->qhead = qh;
3649
3650 if (qh->msg1 > 0) {
3651 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3652 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3653 }
3654 if (qh->msg2 > 0) {
3655 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3656 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3657 }
3658 } else {
3659 ssh->qtail->next = qh;
3660 }
3661 ssh->qtail = qh;
3662}
3663
3664static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3665{
3666 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3667
3668 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3669 SSH2_MSG_REQUEST_SUCCESS)) {
3670 logeventf(ssh, "Remote port forwarding from %s enabled",
3671 pf->sportdesc);
3672 } else {
3673 logeventf(ssh, "Remote port forwarding from %s refused",
3674 pf->sportdesc);
3675
3676 rpf = del234(ssh->rportfwds, pf);
3677 assert(rpf == pf);
fda2feb1 3678 free_rportfwd(pf);
06fadff5 3679 }
3680}
3681
3682static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3683{
84328ddb 3684 const char *portfwd_strptr = cfg->portfwd;
3685 struct ssh_portfwd *epf;
3686 int i;
06fadff5 3687
fda2feb1 3688 if (!ssh->portfwds) {
3689 ssh->portfwds = newtree234(ssh_portcmp);
3690 } else {
3691 /*
3692 * Go through the existing port forwardings and tag them
84328ddb 3693 * with status==DESTROY. Any that we want to keep will be
3694 * re-enabled (status==KEEP) as we go through the
3695 * configuration and find out which bits are the same as
3696 * they were before.
fda2feb1 3697 */
3698 struct ssh_portfwd *epf;
3699 int i;
3700 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 3701 epf->status = DESTROY;
fda2feb1 3702 }
3703
06fadff5 3704 while (*portfwd_strptr) {
84328ddb 3705 char address_family, type;
3706 int sport,dport,sserv,dserv;
3707 char sports[256], dports[256], saddr[256], host[256];
3708 int n;
3709
05581745 3710 address_family = 'A';
3711 type = 'L';
84328ddb 3712 if (*portfwd_strptr == 'A' ||
3713 *portfwd_strptr == '4' ||
3714 *portfwd_strptr == '6')
3715 address_family = *portfwd_strptr++;
3716 if (*portfwd_strptr == 'L' ||
3717 *portfwd_strptr == 'R' ||
3718 *portfwd_strptr == 'D')
3719 type = *portfwd_strptr++;
05581745 3720
06fadff5 3721 saddr[0] = '\0';
05581745 3722
06fadff5 3723 n = 0;
3724 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3725 if (*portfwd_strptr == ':') {
3726 /*
3727 * We've seen a colon in the middle of the
3728 * source port number. This means that
3729 * everything we've seen until now is the
3730 * source _address_, so we'll move it into
3731 * saddr and start sports from the beginning
3732 * again.
3733 */
3734 portfwd_strptr++;
3735 sports[n] = '\0';
3736 if (ssh->version == 1 && type == 'R') {
3737 logeventf(ssh, "SSH1 cannot handle remote source address "
3738 "spec \"%s\"; ignoring", sports);
3739 } else
3740 strcpy(saddr, sports);
3741 n = 0;
3742 }
3743 if (n < 255) sports[n++] = *portfwd_strptr++;
3744 }
3745 sports[n] = 0;
3746 if (type != 'D') {
3747 if (*portfwd_strptr == '\t')
3748 portfwd_strptr++;
3749 n = 0;
3750 while (*portfwd_strptr && *portfwd_strptr != ':') {
3751 if (n < 255) host[n++] = *portfwd_strptr++;
3752 }
3753 host[n] = 0;
3754 if (*portfwd_strptr == ':')
3755 portfwd_strptr++;
3756 n = 0;
3757 while (*portfwd_strptr) {
3758 if (n < 255) dports[n++] = *portfwd_strptr++;
3759 }
3760 dports[n] = 0;
3761 portfwd_strptr++;
3762 dport = atoi(dports);
3763 dserv = 0;
3764 if (dport == 0) {
3765 dserv = 1;
3766 dport = net_service_lookup(dports);
3767 if (!dport) {
3768 logeventf(ssh, "Service lookup failed for destination"
3769 " port \"%s\"", dports);
3770 }
3771 }
3772 } else {
3773 while (*portfwd_strptr) portfwd_strptr++;
3774 dport = dserv = -1;
3775 portfwd_strptr++; /* eat the NUL and move to next one */
3776 }
3777 sport = atoi(sports);
3778 sserv = 0;
3779 if (sport == 0) {
3780 sserv = 1;
3781 sport = net_service_lookup(sports);
3782 if (!sport) {
3783 logeventf(ssh, "Service lookup failed for source"
3784 " port \"%s\"", sports);
3785 }
3786 }
3787 if (sport && dport) {
3788 /* Set up a description of the source port. */
fda2feb1 3789 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 3790
3791 pfrec = snew(struct ssh_portfwd);
3792 pfrec->type = type;
3793 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 3794 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 3795 pfrec->sport = sport;
84328ddb 3796 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 3797 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 3798 pfrec->dport = dport;
3799 pfrec->local = NULL;
3800 pfrec->remote = NULL;
05581745 3801 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3802 address_family == '6' ? ADDRTYPE_IPV6 :
3803 ADDRTYPE_UNSPEC);
fda2feb1 3804
3805 epfrec = add234(ssh->portfwds, pfrec);
3806 if (epfrec != pfrec) {
3807 /*
3808 * We already have a port forwarding with precisely
3809 * these parameters. Hence, no need to do anything;
84328ddb 3810 * simply tag the existing one as KEEP.
fda2feb1 3811 */
84328ddb 3812 epfrec->status = KEEP;
fda2feb1 3813 free_portfwd(pfrec);
84328ddb 3814 } else {
3815 pfrec->status = CREATE;
3816 }
3817 }
3818 }
3819
3820 /*
3821 * Now go through and destroy any port forwardings which were
3822 * not re-enabled.
3823 */
3824 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3825 if (epf->status == DESTROY) {
3826 char *message;
3827
3828 message = dupprintf("%s port forwarding from %s%s%d",
3829 epf->type == 'L' ? "local" :
3830 epf->type == 'R' ? "remote" : "dynamic",
3831 epf->saddr ? epf->saddr : "",
3832 epf->saddr ? ":" : "",
3833 epf->sport);
3834
3835 if (epf->type != 'D') {
3836 char *msg2 = dupprintf("%s to %s:%d", message,
3837 epf->daddr, epf->dport);
3838 sfree(message);
3839 message = msg2;
3840 }
3841
3842 logeventf(ssh, "Cancelling %s", message);
3843 sfree(message);
3844
3845 if (epf->remote) {
3846 struct ssh_rportfwd *rpf = epf->remote;
3847 struct Packet *pktout;
3848
3849 /*
3850 * Cancel the port forwarding at the server
3851 * end.
3852 */
3853 if (ssh->version == 1) {
3854 /*
3855 * We cannot cancel listening ports on the
3856 * server side in SSH1! There's no message
3857 * to support it. Instead, we simply remove
3858 * the rportfwd record from the local end
3859 * so that any connections the server tries
3860 * to make on it are rejected.
3861 */
3862 } else {
3863 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3864 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3865 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3866 if (epf->saddr) {
3867 ssh2_pkt_addstring(pktout, epf->saddr);
3868 } else if (ssh->cfg.rport_acceptall) {
3869 ssh2_pkt_addstring(pktout, "0.0.0.0");
3870 } else {
3871 ssh2_pkt_addstring(pktout, "127.0.0.1");
3872 }
3873 ssh2_pkt_adduint32(pktout, epf->sport);
3874 ssh2_pkt_send(ssh, pktout);
3875 }
3876
3877 del234(ssh->rportfwds, rpf);
3878 free_rportfwd(rpf);
3879 } else if (epf->local) {
3880 pfd_terminate(epf->local);
3881 }
3882
3883 delpos234(ssh->portfwds, i);
3884 free_portfwd(epf);
3885 i--; /* so we don't skip one in the list */
3886 }
3887
3888 /*
3889 * And finally, set up any new port forwardings (status==CREATE).
3890 */
3891 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3892 if (epf->status == CREATE) {
3893 char *sportdesc, *dportdesc;
3fe92132 3894 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 3895 epf->saddr ? epf->saddr : "",
3896 epf->saddr ? ":" : "",
3fe92132 3897 epf->sserv ? epf->sserv : "",
3898 epf->sserv ? "(" : "",
3899 epf->sport,
3900 epf->sserv ? ")" : "");
84328ddb 3901 if (epf->type == 'D') {
3902 dportdesc = NULL;
3903 } else {
3fe92132 3904 dportdesc = dupprintf("%s:%s%s%d%s",
3905 epf->daddr,
3906 epf->dserv ? epf->dserv : "",
3907 epf->dserv ? "(" : "",
3908 epf->dport,
3909 epf->dserv ? ")" : "");
84328ddb 3910 }
05581745 3911
84328ddb 3912 if (epf->type == 'L') {
3913 const char *err = pfd_addforward(epf->daddr, epf->dport,
3914 epf->saddr, epf->sport,
3915 ssh, &ssh->cfg,
3916 &epf->local,
3917 epf->addressfamily);
3918
3919 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3920 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3921 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3922 sportdesc, dportdesc,
3923 err ? " failed: " : "", err ? err : "");
3924 } else if (epf->type == 'D') {
06fadff5 3925 const char *err = pfd_addforward(NULL, -1,
84328ddb 3926 epf->saddr, epf->sport,
3927 ssh, &ssh->cfg,
3928 &epf->local,
3929 epf->addressfamily);
3930
3931 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3932 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3933 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3934 sportdesc,
3935 err ? " failed: " : "", err ? err : "");
06fadff5 3936 } else {
3937 struct ssh_rportfwd *pf;
3938
3939 /*
3940 * Ensure the remote port forwardings tree exists.
3941 */
3942 if (!ssh->rportfwds) {
3943 if (ssh->version == 1)
3944 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3945 else
3946 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3947 }
3948
3949 pf = snew(struct ssh_rportfwd);
84328ddb 3950 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
3951 pf->dhost[lenof(pf->dhost)-1] = '\0';
3952 pf->dport = epf->dport;
3953 pf->sport = epf->sport;
06fadff5 3954 if (add234(ssh->rportfwds, pf) != pf) {
3955 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 3956 epf->daddr, epf->dport);
06fadff5 3957 sfree(pf);
3958 } else {
3959 logeventf(ssh, "Requesting remote port %s"
84328ddb 3960 " forward to %s", sportdesc, dportdesc);
06fadff5 3961
3962 pf->sportdesc = sportdesc;
3963 sportdesc = NULL;
84328ddb 3964 epf->remote = pf;
3965 pf->pfrec = epf;
06fadff5 3966
3967 if (ssh->version == 1) {
3968 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 3969 PKT_INT, epf->sport,
3970 PKT_STR, epf->daddr,
3971 PKT_INT, epf->dport,
06fadff5 3972 PKT_END);
3973 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
3974 SSH1_SMSG_FAILURE,
3975 ssh_rportfwd_succfail, pf);
3976 } else {
3977 struct Packet *pktout;
3978 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3979 ssh2_pkt_addstring(pktout, "tcpip-forward");
3980 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 3981 if (epf->saddr) {
3982 ssh2_pkt_addstring(pktout, epf->saddr);
06fadff5 3983 } else if (ssh->cfg.rport_acceptall) {
3984 ssh2_pkt_addstring(pktout, "0.0.0.0");
3985 } else {
3986 ssh2_pkt_addstring(pktout, "127.0.0.1");
3987 }
84328ddb 3988 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 3989 ssh2_pkt_send(ssh, pktout);
3990
3991 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
3992 SSH2_MSG_REQUEST_FAILURE,
3993 ssh_rportfwd_succfail, pf);
3994 }
3995 }
3996 }
3997 sfree(sportdesc);
84328ddb 3998 sfree(dportdesc);
06fadff5 3999 }
06fadff5 4000}
4001
51df0ab5 4002static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4003{
4004 char *string;
4005 int stringlen, bufsize;
4006
4007 ssh_pkt_getstring(pktin, &string, &stringlen);
4008 if (string == NULL) {
4009 bombout(("Incoming terminal data packet was badly formed"));
4010 return;
4011 }
4012
4013 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4014 string, stringlen);
4015 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4016 ssh->v1_stdout_throttling = 1;
4017 ssh1_throttle(ssh, +1);
4018 }
4019}
4020
4021static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4022{
4023 /* Remote side is trying to open a channel to talk to our
4024 * X-Server. Give them back a local channel number. */
4025 struct ssh_channel *c;
4026 int remoteid = ssh_pkt_getuint32(pktin);
4027
4028 logevent("Received X11 connect request");
4029 /* Refuse if X11 forwarding is disabled. */
4030 if (!ssh->X11_fwd_enabled) {
4031 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4032 PKT_INT, remoteid, PKT_END);
4033 logevent("Rejected X11 connect request");
4034 } else {
4035 c = snew(struct ssh_channel);
4036 c->ssh = ssh;
4037
4038 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4039 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4040 logevent("Opening X11 forward connection failed");
4041 sfree(c);
4042 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4043 PKT_INT, remoteid, PKT_END);
4044 } else {
4045 logevent
4046 ("Opening X11 forward connection succeeded");
4047 c->remoteid = remoteid;
4048 c->localid = alloc_channel_id(ssh);
4049 c->closes = 0;
4050 c->v.v1.throttling = 0;
4051 c->type = CHAN_X11; /* identify channel type */
4052 add234(ssh->channels, c);
4053 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4054 PKT_INT, c->remoteid, PKT_INT,
4055 c->localid, PKT_END);
4056 logevent("Opened X11 forward channel");
4057 }
4058 }
4059}
4060
4061static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4062{
4063 /* Remote side is trying to open a channel to talk to our
4064 * agent. Give them back a local channel number. */
4065 struct ssh_channel *c;
4066 int remoteid = ssh_pkt_getuint32(pktin);
4067
4068 /* Refuse if agent forwarding is disabled. */
4069 if (!ssh->agentfwd_enabled) {
4070 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4071 PKT_INT, remoteid, PKT_END);
4072 } else {
4073 c = snew(struct ssh_channel);
4074 c->ssh = ssh;
4075 c->remoteid = remoteid;
4076 c->localid = alloc_channel_id(ssh);
4077 c->closes = 0;
4078 c->v.v1.throttling = 0;
4079 c->type = CHAN_AGENT; /* identify channel type */
4080 c->u.a.lensofar = 0;
4081 add234(ssh->channels, c);
4082 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4083 PKT_INT, c->remoteid, PKT_INT, c->localid,
4084 PKT_END);
4085 }
4086}
4087
4088static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4089{
4090 /* Remote side is trying to open a channel to talk to a
4091 * forwarded port. Give them back a local channel number. */
4092 struct ssh_channel *c;
05581745 4093 struct ssh_rportfwd pf, *pfp;
51df0ab5 4094 int remoteid;
4095 int hostsize, port;
4096 char *host, buf[1024];
4097 const char *e;
4098 c = snew(struct ssh_channel);
4099 c->ssh = ssh;
4100
4101 remoteid = ssh_pkt_getuint32(pktin);
4102 ssh_pkt_getstring(pktin, &host, &hostsize);
4103 port = ssh_pkt_getuint32(pktin);
4104
4105 if (hostsize >= lenof(pf.dhost))
4106 hostsize = lenof(pf.dhost)-1;
4107 memcpy(pf.dhost, host, hostsize);
4108 pf.dhost[hostsize] = '\0';
4109 pf.dport = port;
05581745 4110 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4111
05581745 4112 if (pfp == NULL) {
51df0ab5 4113 sprintf(buf, "Rejected remote port open request for %s:%d",
4114 pf.dhost, port);
4115 logevent(buf);
4116 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4117 PKT_INT, remoteid, PKT_END);
4118 } else {
4119 sprintf(buf, "Received remote port open request for %s:%d",
4120 pf.dhost, port);
4121 logevent(buf);
4122 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4123 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4124 if (e != NULL) {
4125 char buf[256];
4126 sprintf(buf, "Port open failed: %s", e);
4127 logevent(buf);
4128 sfree(c);
4129 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4130 PKT_INT, remoteid, PKT_END);
4131 } else {
4132 c->remoteid = remoteid;
4133 c->localid = alloc_channel_id(ssh);
4134 c->closes = 0;
4135 c->v.v1.throttling = 0;
4136 c->type = CHAN_SOCKDATA; /* identify channel type */
4137 add234(ssh->channels, c);
4138 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4139 PKT_INT, c->remoteid, PKT_INT,
4140 c->localid, PKT_END);
4141 logevent("Forwarded port opened successfully");
4142 }
4143 }
4144}
4145
4146static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4147{
4148 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4149 unsigned int localid = ssh_pkt_getuint32(pktin);
4150 struct ssh_channel *c;
4151
4152 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4153 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4154 c->remoteid = localid;
4155 c->type = CHAN_SOCKDATA;
4156 c->v.v1.throttling = 0;
4157 pfd_confirm(c->u.pfd.s);
4158 }
4159
4160 if (c && c->closes) {
4161 /*
4162 * We have a pending close on this channel,
4163 * which we decided on before the server acked
4164 * the channel open. So now we know the
4165 * remoteid, we can close it again.
4166 */
4167 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4168 PKT_INT, c->remoteid, PKT_END);
4169 }
4170}
4171
4172static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4173{
4174 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4175 struct ssh_channel *c;
4176
4177 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4178 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4179 logevent("Forwarded connection refused by server");
4180 pfd_close(c->u.pfd.s);
4181 del234(ssh->channels, c);
4182 sfree(c);
4183 }
4184}
4185
4186static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4187{
4188 /* Remote side closes a channel. */
4189 unsigned i = ssh_pkt_getuint32(pktin);
4190 struct ssh_channel *c;
4191 c = find234(ssh->channels, &i, ssh_channelfind);
4192 if (c && ((int)c->remoteid) != -1) {
4193 int closetype;
4194 closetype =
4195 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4196
4197 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4198 logevent("Forwarded X11 connection terminated");
4199 assert(c->u.x11.s != NULL);
4200 x11_close(c->u.x11.s);
4201 c->u.x11.s = NULL;
4202 }
4203 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4204 logevent("Forwarded port closed");
4205 assert(c->u.pfd.s != NULL);
4206 pfd_close(c->u.pfd.s);
4207 c->u.pfd.s = NULL;
4208 }
4209
4210 c->closes |= (closetype << 2); /* seen this message */
4211 if (!(c->closes & closetype)) {
4212 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4213 PKT_END);
4214 c->closes |= closetype; /* sent it too */
4215 }
4216
4217 if (c->closes == 15) {
4218 del234(ssh->channels, c);
4219 sfree(c);
4220 }
4221 } else {
4222 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4223 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4224 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4225 i));
4226 }
4227}
4228
4229static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4230{
4231 /* Data sent down one of our channels. */
4232 int i = ssh_pkt_getuint32(pktin);
4233 char *p;
aa63ab7e 4234 unsigned int len;
51df0ab5 4235 struct ssh_channel *c;
4236
4237 ssh_pkt_getstring(pktin, &p, &len);
4238
4239 c = find234(ssh->channels, &i, ssh_channelfind);
4240 if (c) {
4241 int bufsize = 0;
4242 switch (c->type) {
4243 case CHAN_X11:
4244 bufsize = x11_send(c->u.x11.s, p, len);
4245 break;
4246 case CHAN_SOCKDATA:
4247 bufsize = pfd_send(c->u.pfd.s, p, len);
4248 break;
4249 case CHAN_AGENT:
4250 /* Data for an agent message. Buffer it. */
4251 while (len > 0) {
4252 if (c->u.a.lensofar < 4) {
aa63ab7e 4253 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4254 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4255 l);
4256 p += l;
4257 len -= l;
4258 c->u.a.lensofar += l;
4259 }
4260 if (c->u.a.lensofar == 4) {
4261 c->u.a.totallen =
4262 4 + GET_32BIT(c->u.a.msglen);
4263 c->u.a.message = snewn(c->u.a.totallen,
4264 unsigned char);
4265 memcpy(c->u.a.message, c->u.a.msglen, 4);
4266 }
4267 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4268 unsigned int l =
51df0ab5 4269 min(c->u.a.totallen - c->u.a.lensofar,
4270 len);
4271 memcpy(c->u.a.message + c->u.a.lensofar, p,
4272 l);
4273 p += l;
4274 len -= l;
4275 c->u.a.lensofar += l;
4276 }
4277 if (c->u.a.lensofar == c->u.a.totallen) {
4278 void *reply;
4279 int replylen;
4280 if (agent_query(c->u.a.message,
4281 c->u.a.totallen,
4282 &reply, &replylen,
4283 ssh_agentf_callback, c))
4284 ssh_agentf_callback(c, reply, replylen);
4285 sfree(c->u.a.message);
4286 c->u.a.lensofar = 0;
4287 }
4288 }
4289 bufsize = 0; /* agent channels never back up */
4290 break;
4291 }
4292 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4293 c->v.v1.throttling = 1;
4294 ssh1_throttle(ssh, +1);
4295 }
4296 }
4297}
4298
4299static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4300{
4301 char buf[100];
4302 ssh->exitcode = ssh_pkt_getuint32(pktin);
4303 sprintf(buf, "Server sent command exit status %d",
4304 ssh->exitcode);
4305 logevent(buf);
4306 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4307 /*
4308 * In case `helpful' firewalls or proxies tack
4309 * extra human-readable text on the end of the
4310 * session which we might mistake for another
4311 * encrypted packet, we close the session once
4312 * we've sent EXIT_CONFIRMATION.
4313 */
4314 ssh_closing((Plug)ssh, NULL, 0, 0);
4315}
4316
b09eaa88 4317static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4318 struct Packet *pktin)
32874aea 4319{
b09eaa88 4320 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4321
51df0ab5 4322 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4323 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4324 ssh1_smsg_stdout_stderr_data;
4325
4326 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4327 ssh1_msg_channel_open_confirmation;
4328 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4329 ssh1_msg_channel_open_failure;
4330 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4331 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4332 ssh1_msg_channel_close;
4333 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4334 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4335
86916870 4336 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4337 logevent("Requesting agent forwarding");
51470298 4338 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4339 do {
4340 crReturnV;
ff3187f6 4341 } while (!pktin);
4342 if (pktin->type != SSH1_SMSG_SUCCESS
4343 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4344 bombout(("Protocol confusion"));
7ffdbc1a 4345 crStopV;
ff3187f6 4346 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4347 logevent("Agent forwarding refused");
4348 } else {
4349 logevent("Agent forwarding enabled");
51470298 4350 ssh->agentfwd_enabled = TRUE;
51df0ab5 4351 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4352 }
dacbd0e8 4353 }
4354
86916870 4355 if (ssh->cfg.x11_forward) {
32874aea 4356 char proto[20], data[64];
4357 logevent("Requesting X11 forwarding");
302121de 4358 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4359 data, sizeof(data), ssh->cfg.x11_auth);
4360 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 4361 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4362 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4363 PKT_STR, proto, PKT_STR, data,
86916870 4364 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4365 PKT_END);
32874aea 4366 } else {
51470298 4367 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4368 PKT_STR, proto, PKT_STR, data, PKT_END);
4369 }
4370 do {
4371 crReturnV;
ff3187f6 4372 } while (!pktin);
4373 if (pktin->type != SSH1_SMSG_SUCCESS
4374 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4375 bombout(("Protocol confusion"));
7ffdbc1a 4376 crStopV;
ff3187f6 4377 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4378 logevent("X11 forwarding refused");
4379 } else {
4380 logevent("X11 forwarding enabled");
51470298 4381 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4382 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4383 }
4384 }
4385
06fadff5 4386 ssh_setup_portfwd(ssh, &ssh->cfg);
4387 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4388
86916870 4389 if (!ssh->cfg.nopty) {
a5dd8467 4390 /* Unpick the terminal-speed string. */
4391 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4392 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4393 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4394 /* Send the pty request. */
51470298 4395 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4396 PKT_STR, ssh->cfg.termtype,
51470298 4397 PKT_INT, ssh->term_height,
4398 PKT_INT, ssh->term_width,
a5dd8467 4399 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4400 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4401 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4402 PKT_CHAR, 0, PKT_END);
51470298 4403 ssh->state = SSH_STATE_INTERMED;
32874aea 4404 do {
4405 crReturnV;
ff3187f6 4406 } while (!pktin);
4407 if (pktin->type != SSH1_SMSG_SUCCESS
4408 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4409 bombout(("Protocol confusion"));
7ffdbc1a 4410 crStopV;
ff3187f6 4411 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4412 c_write_str(ssh, "Server refused to allocate pty\r\n");
4413 ssh->editing = ssh->echoing = 1;
32874aea 4414 }
a5dd8467 4415 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4416 ssh->ospeed, ssh->ispeed);
0965bee0 4417 } else {
51470298 4418 ssh->editing = ssh->echoing = 1;
374330e2 4419 }
4420
86916870 4421 if (ssh->cfg.compression) {
51470298 4422 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4423 do {
4424 crReturnV;
ff3187f6 4425 } while (!pktin);
4426 if (pktin->type != SSH1_SMSG_SUCCESS
4427 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4428 bombout(("Protocol confusion"));
7ffdbc1a 4429 crStopV;
ff3187f6 4430 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4431 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4432 }
4ba9b64b 4433 logevent("Started compression");
51470298 4434 ssh->v1_compressing = TRUE;
5366aed8 4435 ssh->cs_comp_ctx = zlib_compress_init();
4436 logevent("Initialised zlib (RFC1950) compression");
4437 ssh->sc_comp_ctx = zlib_decompress_init();
4438 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4439 }
4440
fd5e5847 4441 /*
4442 * Start the shell or command.
4443 *
4444 * Special case: if the first-choice command is an SSH2
4445 * subsystem (hence not usable here) and the second choice
4446 * exists, we fall straight back to that.
4447 */
4448 {
86916870 4449 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 4450
86916870 4451 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4452 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4453 ssh->fallback_cmd = TRUE;
fd5e5847 4454 }
4455 if (*cmd)
51470298 4456 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4457 else
51470298 4458 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4459 logevent("Started session");
4460 }
374330e2 4461
51470298 4462 ssh->state = SSH_STATE_SESSION;
4463 if (ssh->size_needed)
4464 ssh_size(ssh, ssh->term_width, ssh->term_height);
4465 if (ssh->eof_needed)
4466 ssh_special(ssh, TS_EOF);
374330e2 4467
b9d7bcad 4468 if (ssh->ldisc)
4469 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4470 ssh->send_ok = 1;
4471 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4472 while (1) {
d74d141c 4473
51df0ab5 4474 /*
4475 * By this point, most incoming packets are already being
4476 * handled by the dispatch table, and we need only pay
4477 * attention to the unusual ones.
4478 */
0357890f 4479
51df0ab5 4480 crReturnV;
4481 if (pktin) {
4482 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4483 /* may be from EXEC_SHELL on some servers */
ff3187f6 4484 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4485 /* may be from EXEC_SHELL on some servers
374330e2 4486 * if no pty is available or in other odd cases. Ignore */
374330e2 4487 } else {
ff3187f6 4488 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4489 crStopV;
374330e2 4490 }
4491 } else {
8df7a775 4492 while (inlen > 0) {
4493 int len = min(inlen, 512);
9a10ecf4 4494 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4495 PKT_INT, len, PKT_DATA, in, len,
4496 PKTT_OTHER, PKT_END);
8df7a775 4497 in += len;
4498 inlen -= len;
4499 }
374330e2 4500 }
4501 }
4502
4503 crFinishV;
4504}
4505
4506/*
b09eaa88 4507 * Handle the top-level SSH2 protocol.
4508 */
4509static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4510{
4511 char *buf, *msg;
4512 int msglen;
4513
4514 ssh_pkt_getstring(pktin, &msg, &msglen);
4515 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4516 logevent(buf);
4517 sfree(buf);
4518}
4519
4520static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4521{
4522 /* log reason code in disconnect message */
4523 char *msg;
4524 int msglen;
4525
4526 ssh_pkt_getstring(pktin, &msg, &msglen);
4527 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4528}
4529
4530void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4531{
4532 /* Do nothing, because we're ignoring it! Duhh. */
4533}
4534
4535static void ssh1_protocol_setup(Ssh ssh)
4536{
4537 int i;
4538
4539 /*
4540 * Most messages are handled by the coroutines.
4541 */
4542 for (i = 0; i < 256; i++)
4543 ssh->packet_dispatch[i] = NULL;
4544
4545 /*
4546 * These special message types we install handlers for.
4547 */
4548 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4549 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4550 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4551}
4552
4553static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4554 struct Packet *pktin)
4555{
4556 if (ssh->state == SSH_STATE_CLOSED)
4557 return;
4558
4559 if (pktin && ssh->packet_dispatch[pktin->type]) {
4560 ssh->packet_dispatch[pktin->type](ssh, pktin);
4561 return;
4562 }
4563
4564 if (!ssh->protocol_initial_phase_done) {
4565 if (do_ssh1_login(ssh, in, inlen, pktin))
4566 ssh->protocol_initial_phase_done = TRUE;
4567 else
4568 return;
4569 }
4570
4571 do_ssh1_connection(ssh, in, inlen, pktin);
4572}
4573
4574/*
e5574168 4575 * Utility routine for decoding comma-separated strings in KEXINIT.
4576 */
32874aea 4577static int in_commasep_string(char *needle, char *haystack, int haylen)
4578{
57356d63 4579 int needlen;
4580 if (!needle || !haystack) /* protect against null pointers */
4581 return 0;
4582 needlen = strlen(needle);
e5574168 4583 while (1) {
32874aea 4584 /*
4585 * Is it at the start of the string?
4586 */
4587 if (haylen >= needlen && /* haystack is long enough */
4588 !memcmp(needle, haystack, needlen) && /* initial match */
4589 (haylen == needlen || haystack[needlen] == ',')
4590 /* either , or EOS follows */
4591 )
4592 return 1;
4593 /*
4594 * If not, search for the next comma and resume after that.
4595 * If no comma found, terminate.
4596 */
4597 while (haylen > 0 && *haystack != ',')
4598 haylen--, haystack++;
4599 if (haylen == 0)
4600 return 0;
4601 haylen--, haystack++; /* skip over comma itself */
e5574168 4602 }
4603}
4604
4605/*
d39f364a 4606 * SSH2 key creation method.
4607 */
d8baa528 4608static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4609 unsigned char *sessid, char chr,
4610 unsigned char *keyspace)
32874aea 4611{
d39f364a 4612 SHA_State s;
4613 /* First 20 bytes. */
4614 SHA_Init(&s);
51470298 4615 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4616 sha_mpint(&s, K);
d39f364a 4617 SHA_Bytes(&s, H, 20);
4618 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4619 SHA_Bytes(&s, sessid, 20);
d39f364a 4620 SHA_Final(&s, keyspace);
4621 /* Next 20 bytes. */
4622 SHA_Init(&s);
51470298 4623 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4624 sha_mpint(&s, K);
d39f364a 4625 SHA_Bytes(&s, H, 20);
4626 SHA_Bytes(&s, keyspace, 20);
32874aea 4627 SHA_Final(&s, keyspace + 20);
d39f364a 4628}
4629
4630/*
7cca0d81 4631 * Handle the SSH2 transport layer.
e5574168 4632 */
ff3187f6 4633static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4634 struct Packet *pktin)
e5574168 4635{
51470298 4636 struct do_ssh2_transport_state {
4637 int nbits, pbits, warn;
4638 Bignum p, g, e, f, K;
4639 int kex_init_value, kex_reply_value;
4640 const struct ssh_mac **maclist;
4641 int nmacs;
4642 const struct ssh2_cipher *cscipher_tobe;
4643 const struct ssh2_cipher *sccipher_tobe;
4644 const struct ssh_mac *csmac_tobe;
4645 const struct ssh_mac *scmac_tobe;
4646 const struct ssh_compress *cscomp_tobe;
4647 const struct ssh_compress *sccomp_tobe;
4648 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4649 int hostkeylen, siglen;
4650 void *hkey; /* actual host key */
4651 unsigned char exchange_hash[20];
83e7d008 4652 int n_preferred_kex;
4653 const struct ssh_kex *preferred_kex[KEX_MAX];
51470298 4654 int n_preferred_ciphers;
4655 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4656 const struct ssh_compress *preferred_comp;
e13bba36 4657 int got_session_id, activated_authconn;
ff3187f6 4658 struct Packet *pktout;
51470298 4659 };
4660 crState(do_ssh2_transport_state);
4661
4662 crBegin(ssh->do_ssh2_transport_crstate);
4663
4664 s->cscipher_tobe = s->sccipher_tobe = NULL;
4665 s->csmac_tobe = s->scmac_tobe = NULL;
4666 s->cscomp_tobe = s->sccomp_tobe = NULL;
4667
e13bba36 4668 s->got_session_id = s->activated_authconn = FALSE;
e5574168 4669
e13bba36 4670 /*
4671 * Be prepared to work around the buggy MAC problem.
4672 */
4673 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4674 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4675 else
4676 s->maclist = macs, s->nmacs = lenof(macs);
4677
4678 begin_key_exchange:
149d2abc 4679 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
51470298 4680 {
e13bba36 4681 int i, j, commalist_started;
4682
51470298 4683 /*
83e7d008 4684 * Set up the preferred key exchange. (NULL => warn below here)
4685 */
4686 s->n_preferred_kex = 0;
4687 for (i = 0; i < KEX_MAX; i++) {
4688 switch (ssh->cfg.ssh_kexlist[i]) {
4689 case KEX_DHGEX:
4690 s->preferred_kex[s->n_preferred_kex++] =
4691 &ssh_diffiehellman_gex;
4692 break;
4693 case KEX_DHGROUP14:
4694 s->preferred_kex[s->n_preferred_kex++] =
4695 &ssh_diffiehellman_group14;
4696 break;
4697 case KEX_DHGROUP1:
4698 s->preferred_kex[s->n_preferred_kex++] =
4699 &ssh_diffiehellman_group1;
4700 break;
4701 case CIPHER_WARN:
4702 /* Flag for later. Don't bother if it's the last in
4703 * the list. */
4704 if (i < KEX_MAX - 1) {
4705 s->preferred_kex[s->n_preferred_kex++] = NULL;
4706 }
4707 break;
4708 }
4709 }
83e7d008 4710
83e7d008 4711 /*
51470298 4712 * Set up the preferred ciphers. (NULL => warn below here)
4713 */
4714 s->n_preferred_ciphers = 0;
4715 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4716 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4717 case CIPHER_BLOWFISH:
4718 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4719 break;
4720 case CIPHER_DES:
86916870 4721 if (ssh->cfg.ssh2_des_cbc) {
51470298 4722 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4723 }
4724 break;
4725 case CIPHER_3DES:
4726 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4727 break;
4728 case CIPHER_AES:
4729 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4730 break;
4731 case CIPHER_WARN:
4732 /* Flag for later. Don't bother if it's the last in
4733 * the list. */
4734 if (i < CIPHER_MAX - 1) {
4735 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4736 }
4737 break;
ca20bfcf 4738 }
ca20bfcf 4739 }
7591b9ff 4740
e13bba36 4741 /*
4742 * Set up preferred compression.
4743 */
4744 if (ssh->cfg.compression)
4745 s->preferred_comp = &ssh_zlib;
4746 else
4747 s->preferred_comp = &ssh_comp_none;
51470298 4748
4749 /*
590f6a5f 4750 * Enable queueing of outgoing auth- or connection-layer
4751 * packets while we are in the middle of a key exchange.
4752 */
4753 ssh->queueing = TRUE;
4754
4755 /*
9442dd57 4756 * Flag that KEX is in progress.
4757 */
4758 ssh->kex_in_progress = TRUE;
4759
4760 /*
51470298 4761 * Construct and send our key exchange packet.
4762 */
ff3187f6 4763 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4764 for (i = 0; i < 16; i++)
ff3187f6 4765 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4766 /* List key exchange algorithms. */
ff3187f6 4767 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4768 commalist_started = 0;
4769 for (i = 0; i < s->n_preferred_kex; i++) {
4770 const struct ssh_kex *k = s->preferred_kex[i];
4771 if (!k) continue; /* warning flag */
4772 if (commalist_started)
ff3187f6 4773 ssh2_pkt_addstring_str(s->pktout, ",");
83e7d008 4774 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4775 commalist_started = 1;
32874aea 4776 }
51470298 4777 /* List server host key algorithms. */
ff3187f6 4778 ssh2_pkt_addstring_start(s->pktout);
51470298 4779 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4780 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4781 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4782 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4783 }
51470298 4784 /* List client->server encryption algorithms. */
ff3187f6 4785 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4786 commalist_started = 0;
51470298 4787 for (i = 0; i < s->n_preferred_ciphers; i++) {
4788 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4789 if (!c) continue; /* warning flag */
4790 for (j = 0; j < c->nciphers; j++) {
83e7d008 4791 if (commalist_started)
ff3187f6 4792 ssh2_pkt_addstring_str(s->pktout, ",");
4793 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4794 commalist_started = 1;
51470298 4795 }
4796 }
4797 /* List server->client encryption algorithms. */
ff3187f6 4798 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4799 commalist_started = 0;
51470298 4800 for (i = 0; i < s->n_preferred_ciphers; i++) {
4801 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4802 if (!c) continue; /* warning flag */
4803 for (j = 0; j < c->nciphers; j++) {
83e7d008 4804 if (commalist_started)
ff3187f6 4805 ssh2_pkt_addstring_str(s->pktout, ",");
4806 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4807 commalist_started = 1;
51470298 4808 }
4809 }
4810 /* List client->server MAC algorithms. */
ff3187f6 4811 ssh2_pkt_addstring_start(s->pktout);
51470298 4812 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4813 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4814 if (i < s->nmacs - 1)
ff3187f6 4815 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4816 }
4817 /* List server->client MAC algorithms. */
ff3187f6 4818 ssh2_pkt_addstring_start(s->pktout);
51470298 4819 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4820 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4821 if (i < s->nmacs - 1)
ff3187f6 4822 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4823 }
4824 /* List client->server compression algorithms. */
ff3187f6 4825 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4826 assert(lenof(compressions) > 1);
ff3187f6 4827 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4828 for (i = 0; i < lenof(compressions); i++) {
4829 const struct ssh_compress *c = compressions[i];
4830 if (c != s->preferred_comp) {
ff3187f6 4831 ssh2_pkt_addstring_str(s->pktout, ",");
4832 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4833 }
51470298 4834 }
4835 /* List server->client 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 client->server languages. Empty list. */
ff3187f6 4847 ssh2_pkt_addstring_start(s->pktout);
51470298 4848 /* List server->client languages. Empty list. */
ff3187f6 4849 ssh2_pkt_addstring_start(s->pktout);
51470298 4850 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4851 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4852 /* Reserved. */
ff3187f6 4853 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4854 }
0db56f73 4855
51470298 4856 ssh->exhash = ssh->exhashbase;
ff3187f6 4857 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4858
590f6a5f 4859 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4860
ff3187f6 4861 if (!pktin)
4862 crWaitUntil(pktin);
4863 if (pktin->length > 5)
4864 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4865
4866 /*
4867 * Now examine the other side's KEXINIT to see what we're up
4868 * to.
4869 */
51470298 4870 {
4871 char *str;
4872 int i, j, len;
4873
ff3187f6 4874 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4875 bombout(("expected key exchange packet from server"));
7ffdbc1a 4876 crStop(0);
32874aea 4877 }
51470298 4878 ssh->kex = NULL;
4879 ssh->hostkey = NULL;
4880 s->cscipher_tobe = NULL;
4881 s->sccipher_tobe = NULL;
4882 s->csmac_tobe = NULL;
4883 s->scmac_tobe = NULL;
4884 s->cscomp_tobe = NULL;
4885 s->sccomp_tobe = NULL;
ff3187f6 4886 pktin->savedpos += 16; /* skip garbage cookie */
4887 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
83e7d008 4888 s->warn = 0;
4889 for (i = 0; i < s->n_preferred_kex; i++) {
4890 const struct ssh_kex *k = s->preferred_kex[i];
4891 if (!k) {
4892 s->warn = 1;
4893 } else if (in_commasep_string(k->name, str, len)) {
4894 ssh->kex = k;
4895 }
4896 if (ssh->kex) {
bb348ab1 4897 if (s->warn) {
4898 sk_set_frozen(ssh->s, 1);
83e7d008 4899 askalg(ssh->frontend, "key-exchange algorithm",
4900 ssh->kex->name);
bb348ab1 4901 sk_set_frozen(ssh->s, 0);
4902 }
51470298 4903 break;
4904 }
32874aea 4905 }
83e7d008 4906 if (!ssh->kex) {
4907 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4908 str ? str : "(null)"));
4909 crStop(0);
4910 }
ff3187f6 4911 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4912 for (i = 0; i < lenof(hostkey_algs); i++) {
4913 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4914 ssh->hostkey = hostkey_algs[i];
4915 break;
4916 }
4917 }
ff3187f6 4918 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4919 s->warn = 0;
4920 for (i = 0; i < s->n_preferred_ciphers; i++) {
4921 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4922 if (!c) {
4923 s->warn = 1;
4924 } else {
4925 for (j = 0; j < c->nciphers; j++) {
4926 if (in_commasep_string(c->list[j]->name, str, len)) {
4927 s->cscipher_tobe = c->list[j];
4928 break;
4929 }
ca20bfcf 4930 }
32874aea 4931 }
51470298 4932 if (s->cscipher_tobe) {
bb348ab1 4933 if (s->warn) {
4934 sk_set_frozen(ssh->s, 1);
83e7d008 4935 askalg(ssh->frontend, "client-to-server cipher",
4936 s->cscipher_tobe->name);
bb348ab1 4937 sk_set_frozen(ssh->s, 0);
4938 }
51470298 4939 break;
4940 }
32874aea 4941 }
51470298 4942 if (!s->cscipher_tobe) {
6b5cf8b4 4943 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4944 str ? str : "(null)"));
7ffdbc1a 4945 crStop(0);
ca20bfcf 4946 }
0ef8f407 4947
ff3187f6 4948 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4949 s->warn = 0;
4950 for (i = 0; i < s->n_preferred_ciphers; i++) {
4951 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4952 if (!c) {
4953 s->warn = 1;
4954 } else {
4955 for (j = 0; j < c->nciphers; j++) {
4956 if (in_commasep_string(c->list[j]->name, str, len)) {
4957 s->sccipher_tobe = c->list[j];
4958 break;
4959 }
ca20bfcf 4960 }
32874aea 4961 }
51470298 4962 if (s->sccipher_tobe) {
bb348ab1 4963 if (s->warn) {
4964 sk_set_frozen(ssh->s, 1);
83e7d008 4965 askalg(ssh->frontend, "server-to-client cipher",
4966 s->sccipher_tobe->name);
bb348ab1 4967 sk_set_frozen(ssh->s, 0);
4968 }
51470298 4969 break;
4970 }
32874aea 4971 }
51470298 4972 if (!s->sccipher_tobe) {
6b5cf8b4 4973 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4974 str ? str : "(null)"));
7ffdbc1a 4975 crStop(0);
ca20bfcf 4976 }
0ef8f407 4977
ff3187f6 4978 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 4979 for (i = 0; i < s->nmacs; i++) {
4980 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4981 s->csmac_tobe = s->maclist[i];
4982 break;
4983 }
32874aea 4984 }
ff3187f6 4985 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 4986 for (i = 0; i < s->nmacs; i++) {
4987 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4988 s->scmac_tobe = s->maclist[i];
4989 break;
4990 }
32874aea 4991 }
ff3187f6 4992 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 4993 for (i = 0; i < lenof(compressions) + 1; i++) {
4994 const struct ssh_compress *c =
4995 i == 0 ? s->preferred_comp : compressions[i - 1];
4996 if (in_commasep_string(c->name, str, len)) {
4997 s->cscomp_tobe = c;
4998 break;
4999 }
32874aea 5000 }
ff3187f6 5001 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5002 for (i = 0; i < lenof(compressions) + 1; i++) {
5003 const struct ssh_compress *c =
5004 i == 0 ? s->preferred_comp : compressions[i - 1];
5005 if (in_commasep_string(c->name, str, len)) {
5006 s->sccomp_tobe = c;
5007 break;
5008 }
32874aea 5009 }
e5574168 5010 }
e5574168 5011
5012 /*
7bd5a860 5013 * Work out the number of bits of key we will need from the key
5014 * exchange. We start with the maximum key length of either
5015 * cipher...
5016 */
5017 {
32874aea 5018 int csbits, scbits;
7bd5a860 5019
51470298 5020 csbits = s->cscipher_tobe->keylen;
5021 scbits = s->sccipher_tobe->keylen;
5022 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 5023 }
5024 /* The keys only have 160-bit entropy, since they're based on
5025 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 5026 if (s->nbits > 160)
5027 s->nbits = 160;
7bd5a860 5028
5029 /*
a92dd380 5030 * If we're doing Diffie-Hellman group exchange, start by
5031 * requesting a group.
e5574168 5032 */
d1aaf71d 5033 if (!ssh->kex->pdata) {
32874aea 5034 logevent("Doing Diffie-Hellman group exchange");
51470298 5035 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 5036 /*
5037 * Work out how big a DH group we will need to allow that
5038 * much data.
7bd5a860 5039 */
51470298 5040 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 5041 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5042 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 5043 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 5044
ff3187f6 5045 crWaitUntil(pktin);
5046 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 5047 bombout(("expected key exchange group packet from server"));
7ffdbc1a 5048 crStop(0);
32874aea 5049 }
ff3187f6 5050 s->p = ssh2_pkt_getmp(pktin);
5051 s->g = ssh2_pkt_getmp(pktin);
5052 if (!s->p || !s->g) {
5053 bombout(("unable to read mp-ints from incoming group packet"));
5054 crStop(0);
5055 }
d1aaf71d 5056 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5057 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5058 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5059 } else {
d1aaf71d 5060 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5061 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5062 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5063 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5064 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5065 ssh->kex->groupname);
8d5de777 5066 }
e5574168 5067
a92dd380 5068 logevent("Doing Diffie-Hellman key exchange");
e5574168 5069 /*
a92dd380 5070 * Now generate and send e for Diffie-Hellman.
e5574168 5071 */
27cd7fc2 5072 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5073 s->pktout = ssh2_pkt_init(s->kex_init_value);
5074 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5075 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5076
ff3187f6 5077 crWaitUntil(pktin);
5078 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5079 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5080 crStop(0);
7cca0d81 5081 }
ff3187f6 5082 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5083 s->f = ssh2_pkt_getmp(pktin);
5084 if (!s->f) {
5085 bombout(("unable to parse key exchange reply packet"));
5086 crStop(0);
5087 }
5088 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5089
27cd7fc2 5090 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5091
51470298 5092 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5093 if (ssh->kex == &ssh_diffiehellman_gex) {
5094 sha_uint32(&ssh->exhash, s->pbits);
5095 sha_mpint(&ssh->exhash, s->p);
5096 sha_mpint(&ssh->exhash, s->g);
a92dd380 5097 }
51470298 5098 sha_mpint(&ssh->exhash, s->e);
5099 sha_mpint(&ssh->exhash, s->f);
5100 sha_mpint(&ssh->exhash, s->K);
5101 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 5102
27cd7fc2 5103 dh_cleanup(ssh->kex_ctx);
fabd1805 5104 ssh->kex_ctx = NULL;
3709bfe9 5105
7cca0d81 5106#if 0
765c4200 5107 debug(("Exchange hash is:\n"));
51470298 5108 dmemdump(s->exchange_hash, 20);
7cca0d81 5109#endif
5110
51470298 5111 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5112 if (!s->hkey ||
5113 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 5114 (char *)s->exchange_hash, 20)) {
6b5cf8b4 5115 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5116 crStop(0);
8d5de777 5117 }
e5574168 5118
5119 /*
7cca0d81 5120 * Authenticate remote host: verify host key. (We've already
5121 * checked the signature of the exchange hash.)
e5574168 5122 */
51470298 5123 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5124 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
bb348ab1 5125 sk_set_frozen(ssh->s, 1);
a8327734 5126 verify_ssh_host_key(ssh->frontend,
5127 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 5128 s->keystr, s->fingerprint);
bb348ab1 5129 sk_set_frozen(ssh->s, 0);
e13bba36 5130 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5131 logevent("Host key fingerprint is:");
51470298 5132 logevent(s->fingerprint);
5e0d7cb8 5133 }
51470298 5134 sfree(s->fingerprint);
5135 sfree(s->keystr);
5136 ssh->hostkey->freekey(s->hkey);
d39f364a 5137
5138 /*
9442dd57 5139 * The exchange hash from the very first key exchange is also
5140 * the session id, used in session key construction and
5141 * authentication.
5142 */
e13bba36 5143 if (!s->got_session_id) {
9442dd57 5144 memcpy(ssh->v2_session_id, s->exchange_hash,
5145 sizeof(s->exchange_hash));
e13bba36 5146 s->got_session_id = TRUE;
5147 }
9442dd57 5148
5149 /*
7cca0d81 5150 * Send SSH2_MSG_NEWKEYS.
d39f364a 5151 */
ff3187f6 5152 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5153 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5154 ssh->outgoing_data_size = 0; /* start counting from here */
5155
5156 /*
5157 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5158 * client-to-server session keys.
9442dd57 5159 */
5160 if (ssh->cs_cipher_ctx)
5161 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5162 ssh->cscipher = s->cscipher_tobe;
5163 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5164
5165 if (ssh->cs_mac_ctx)
5166 ssh->csmac->free_context(ssh->cs_mac_ctx);
5167 ssh->csmac = s->csmac_tobe;
5168 ssh->cs_mac_ctx = ssh->csmac->make_context();
5169
5170 if (ssh->cs_comp_ctx)
5171 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5172 ssh->cscomp = s->cscomp_tobe;
5173 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5174
5175 /*
5176 * Set IVs on client-to-server keys. Here we use the exchange
5177 * hash from the _first_ key exchange.
5178 */
5179 {
5180 unsigned char keyspace[40];
5181 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5182 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5183 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5184 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5185 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5186 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5187 }
5188
5189 logeventf(ssh, "Initialised %.200s client->server encryption",
5190 ssh->cscipher->text_name);
5191 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5192 ssh->csmac->text_name);
5193 if (ssh->cscomp->text_name)
5194 logeventf(ssh, "Initialised %s compression",
5195 ssh->cscomp->text_name);
590f6a5f 5196
5197 /*
5198 * Now our end of the key exchange is complete, we can send all
5199 * our queued higher-layer packets.
5200 */
5201 ssh->queueing = FALSE;
5202 ssh2_pkt_queuesend(ssh);
d39f364a 5203
5204 /*
8406eaf9 5205 * Expect SSH2_MSG_NEWKEYS from server.
5206 */
ff3187f6 5207 crWaitUntil(pktin);
5208 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5209 bombout(("expected new-keys packet from server"));
7ffdbc1a 5210 crStop(0);
8406eaf9 5211 }
9442dd57 5212 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5213
5214 /*
9442dd57 5215 * We've seen server NEWKEYS, so create and initialise
5216 * server-to-client session keys.
d39f364a 5217 */
371e569c 5218 if (ssh->sc_cipher_ctx)
5219 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5220 ssh->sccipher = s->sccipher_tobe;
371e569c 5221 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5222
e0e1a00d 5223 if (ssh->sc_mac_ctx)
5224 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5225 ssh->scmac = s->scmac_tobe;
e0e1a00d 5226 ssh->sc_mac_ctx = ssh->scmac->make_context();
5227
5366aed8 5228 if (ssh->sc_comp_ctx)
5229 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5230 ssh->sccomp = s->sccomp_tobe;
5366aed8 5231 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5232
d39f364a 5233 /*
9442dd57 5234 * Set IVs on server-to-client keys. Here we use the exchange
5235 * hash from the _first_ key exchange.
d39f364a 5236 */
51470298 5237 {
5238 unsigned char keyspace[40];
51470298 5239 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 5240 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 5241 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 5242 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 5243 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 5244 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5245 }
57356d63 5246 logeventf(ssh, "Initialised %.200s server->client encryption",
5247 ssh->sccipher->text_name);
6c135243 5248 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5249 ssh->scmac->text_name);
57356d63 5250 if (ssh->sccomp->text_name)
5251 logeventf(ssh, "Initialised %s decompression",
5252 ssh->sccomp->text_name);
9442dd57 5253
5254 /*
5255 * Free key exchange data.
5256 */
679539d7 5257 freebn(s->f);
679539d7 5258 freebn(s->K);
b3949e7e 5259 if (ssh->kex == &ssh_diffiehellman_gex) {
5260 freebn(s->g);
5261 freebn(s->p);
5262 }
d39f364a 5263
033b4cef 5264 /*
e13bba36 5265 * Key exchange is over. Loop straight back round if we have a
5266 * deferred rekey reason.
5267 */
5268 if (ssh->deferred_rekey_reason) {
5269 logevent(ssh->deferred_rekey_reason);
5270 pktin = NULL;
5271 ssh->deferred_rekey_reason = NULL;
5272 goto begin_key_exchange;
5273 }
5274
5275 /*
5276 * Otherwise, schedule a timer for our next rekey.
9442dd57 5277 */
5278 ssh->kex_in_progress = FALSE;
e6c1536e 5279 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5280 if (ssh->cfg.ssh_rekey_time != 0)
5281 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5282 ssh2_timer, ssh);
e13bba36 5283
9442dd57 5284 /*
0db56f73 5285 * If this is the first key exchange phase, we must pass the
5286 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5287 * wants to see it but because it will need time to initialise
5288 * itself before it sees an actual packet. In subsequent key
5289 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5290 * it would only confuse the layer above.
5291 */
e13bba36 5292 if (s->activated_authconn) {
b09eaa88 5293 crReturn(1);
0db56f73 5294 }
e13bba36 5295 s->activated_authconn = TRUE;
0db56f73 5296
5297 /*
7cca0d81 5298 * Now we're encrypting. Begin returning 1 to the protocol main
5299 * function so that other things can run on top of the
5300 * transport. If we ever see a KEXINIT, we must go back to the
5301 * start.
9442dd57 5302 *
5303 * We _also_ go back to the start if we see pktin==NULL and
5304 * inlen==-1, because this is a special signal meaning
5305 * `initiate client-driven rekey', and `in' contains a message
5306 * giving the reason for the rekey.
033b4cef 5307 */
9442dd57 5308 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5309 (!pktin && inlen == -1))) {
32874aea 5310 crReturn(1);
e96adf72 5311 }
9442dd57 5312 if (pktin) {
5313 logevent("Server initiated key re-exchange");
5314 } else {
5315 logevent((char *)in);
5316 }
7cca0d81 5317 goto begin_key_exchange;
e5574168 5318
5319 crFinish(1);
5320}
5321
7cca0d81 5322/*
783415f8 5323 * Add data to an SSH2 channel output buffer.
5324 */
32874aea 5325static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5326 int len)
5327{
5471d09a 5328 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5329}
5330
5331/*
5332 * Attempt to send data on an SSH2 channel.
5333 */
5471d09a 5334static int ssh2_try_send(struct ssh_channel *c)
32874aea 5335{
51470298 5336 Ssh ssh = c->ssh;
ff3187f6 5337 struct Packet *pktout;
51470298 5338
5471d09a 5339 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5340 int len;
5341 void *data;
5342 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5343 if ((unsigned)len > c->v.v2.remwindow)
5344 len = c->v.v2.remwindow;
5345 if ((unsigned)len > c->v.v2.remmaxpkt)
5346 len = c->v.v2.remmaxpkt;
ff3187f6 5347 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5348 ssh2_pkt_adduint32(pktout, c->remoteid);
5349 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5350 ssh2_pkt_addstring_start(pktout);
5351 ssh2_pkt_addstring_data(pktout, data, len);
5352 end_log_omission(ssh, pktout);
5353 ssh2_pkt_send(ssh, pktout);
5471d09a 5354 bufchain_consume(&c->v.v2.outbuffer, len);
5355 c->v.v2.remwindow -= len;
5356 }
5357
5358 /*
5359 * After having sent as much data as we can, return the amount
5360 * still buffered.
5361 */
5362 return bufchain_size(&c->v.v2.outbuffer);
5363}
5364
5365/*
5366 * Potentially enlarge the window on an SSH2 channel.
5367 */
5368static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5369{
51470298 5370 Ssh ssh = c->ssh;
5371
6b69f42e 5372 /*
5373 * Never send WINDOW_ADJUST for a channel that the remote side
5374 * already thinks it's closed; there's no point, since it won't
5375 * be sending any more data anyway.
5376 */
5377 if (c->closes != 0)
5378 return;
5379
5471d09a 5380 if (newwin > c->v.v2.locwindow) {
ff3187f6 5381 struct Packet *pktout;
5382
5383 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5384 ssh2_pkt_adduint32(pktout, c->remoteid);
5385 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5386 ssh2_pkt_send(ssh, pktout);
5471d09a 5387 c->v.v2.locwindow = newwin;
783415f8 5388 }
5389}
5390
51df0ab5 5391static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5392{
5393 unsigned i = ssh_pkt_getuint32(pktin);
5394 struct ssh_channel *c;
5395 c = find234(ssh->channels, &i, ssh_channelfind);
5396 if (c && !c->closes)
5397 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5398}
5399
51df0ab5 5400static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5401{
5402 char *data;
aa63ab7e 5403 unsigned int length;
51df0ab5 5404 unsigned i = ssh_pkt_getuint32(pktin);
5405 struct ssh_channel *c;
5406 c = find234(ssh->channels, &i, ssh_channelfind);
5407 if (!c)
5408 return; /* nonexistent channel */
5409 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5410 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5411 return; /* extended but not stderr */
5412 ssh_pkt_getstring(pktin, &data, &length);
5413 if (data) {
5414 int bufsize = 0;
5415 c->v.v2.locwindow -= length;
5416 switch (c->type) {
5417 case CHAN_MAINSESSION:
5418 bufsize =
5419 from_backend(ssh->frontend, pktin->type ==
5420 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5421 data, length);
5422 break;
5423 case CHAN_X11:
5424 bufsize = x11_send(c->u.x11.s, data, length);
5425 break;
5426 case CHAN_SOCKDATA:
5427 bufsize = pfd_send(c->u.pfd.s, data, length);
5428 break;
5429 case CHAN_AGENT:
5430 while (length > 0) {
5431 if (c->u.a.lensofar < 4) {
aa63ab7e 5432 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5433 memcpy(c->u.a.msglen + c->u.a.lensofar,
5434 data, l);
5435 data += l;
5436 length -= l;
5437 c->u.a.lensofar += l;
5438 }
5439 if (c->u.a.lensofar == 4) {
5440 c->u.a.totallen =
5441 4 + GET_32BIT(c->u.a.msglen);
5442 c->u.a.message = snewn(c->u.a.totallen,
5443 unsigned char);
5444 memcpy(c->u.a.message, c->u.a.msglen, 4);
5445 }
5446 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5447 unsigned int l =
51df0ab5 5448 min(c->u.a.totallen - c->u.a.lensofar,
5449 length);
5450 memcpy(c->u.a.message + c->u.a.lensofar,
5451 data, l);
5452 data += l;
5453 length -= l;
5454 c->u.a.lensofar += l;
5455 }
5456 if (c->u.a.lensofar == c->u.a.totallen) {
5457 void *reply;
5458 int replylen;
5459 if (agent_query(c->u.a.message,
5460 c->u.a.totallen,
5461 &reply, &replylen,
5462 ssh_agentf_callback, c))
5463 ssh_agentf_callback(c, reply, replylen);
5464 sfree(c->u.a.message);
5465 c->u.a.lensofar = 0;
5466 }
5467 }
5468 bufsize = 0;
5469 break;
5470 }
5471 /*
5472 * If we are not buffering too much data,
5473 * enlarge the window again at the remote side.
5474 */
5475 if (bufsize < OUR_V2_WINSIZE)
5476 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5477 }
5478}
5479
5480static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5481{
5482 unsigned i = ssh_pkt_getuint32(pktin);
5483 struct ssh_channel *c;
5484
5485 c = find234(ssh->channels, &i, ssh_channelfind);
5486 if (!c)
5487 return; /* nonexistent channel */
5488
5489 if (c->type == CHAN_X11) {
5490 /*
5491 * Remote EOF on an X11 channel means we should
5492 * wrap up and close the channel ourselves.
5493 */
5494 x11_close(c->u.x11.s);
5495 sshfwd_close(c);
5496 } else if (c->type == CHAN_AGENT) {
5497 sshfwd_close(c);
5498 } else if (c->type == CHAN_SOCKDATA) {
5499 pfd_close(c->u.pfd.s);
5500 sshfwd_close(c);
5501 }
5502}
5503
5504static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5505{
5506 unsigned i = ssh_pkt_getuint32(pktin);
5507 struct ssh_channel *c;
5508 struct Packet *pktout;
5509
5510 c = find234(ssh->channels, &i, ssh_channelfind);
5511 if (!c || ((int)c->remoteid) == -1) {
5512 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5513 c ? "half-open" : "nonexistent", i));
5514 return;
5515 }
5516 /* Do pre-close processing on the channel. */
5517 switch (c->type) {
5518 case CHAN_MAINSESSION:
5519 ssh->mainchan = NULL;
5520 update_specials_menu(ssh->frontend);
5521 break;
5522 case CHAN_X11:
5523 if (c->u.x11.s != NULL)
5524 x11_close(c->u.x11.s);
5525 sshfwd_close(c);
5526 break;
5527 case CHAN_AGENT:
5528 sshfwd_close(c);
5529 break;
5530 case CHAN_SOCKDATA:
5531 if (c->u.pfd.s != NULL)
5532 pfd_close(c->u.pfd.s);
5533 sshfwd_close(c);
5534 break;
5535 }
5536 if (c->closes == 0) {
5537 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5538 ssh2_pkt_adduint32(pktout, c->remoteid);
5539 ssh2_pkt_send(ssh, pktout);
5540 }
5541 del234(ssh->channels, c);
5542 bufchain_clear(&c->v.v2.outbuffer);
5543 sfree(c);
5544
5545 /*
5546 * See if that was the last channel left open.
5547 * (This is only our termination condition if we're
5548 * not running in -N mode.)
5549 */
5550 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5551 logevent("All channels closed. Disconnecting");
5552#if 0
5553 /*
5554 * We used to send SSH_MSG_DISCONNECT here,
5555 * because I'd believed that _every_ conforming
5556 * SSH2 connection had to end with a disconnect
5557 * being sent by at least one side; apparently
5558 * I was wrong and it's perfectly OK to
5559 * unceremoniously slam the connection shut
5560 * when you're done, and indeed OpenSSH feels
5561 * this is more polite than sending a
5562 * DISCONNECT. So now we don't.
5563 */
5564 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5565 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5566 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5567 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5568 ssh2_pkt_send_noqueue(ssh, s->pktout);
5569#endif
5570 ssh_closing((Plug)ssh, NULL, 0, 0);
5571 }
5572}
5573
5574static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5575{
5576 unsigned i = ssh_pkt_getuint32(pktin);
5577 struct ssh_channel *c;
5578 struct Packet *pktout;
5579
5580 c = find234(ssh->channels, &i, ssh_channelfind);
5581 if (!c)
5582 return; /* nonexistent channel */
5583 if (c->type != CHAN_SOCKDATA_DORMANT)
5584 return; /* dunno why they're confirming this */
5585 c->remoteid = ssh_pkt_getuint32(pktin);
5586 c->type = CHAN_SOCKDATA;
5587 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5588 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5589 if (c->u.pfd.s)
5590 pfd_confirm(c->u.pfd.s);
5591 if (c->closes) {
5592 /*
5593 * We have a pending close on this channel,
5594 * which we decided on before the server acked
5595 * the channel open. So now we know the
5596 * remoteid, we can close it again.
5597 */
5598 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5599 ssh2_pkt_adduint32(pktout, c->remoteid);
5600 ssh2_pkt_send(ssh, pktout);
5601 }
5602}
5603
5604static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5605{
5606 static const char *const reasons[] = {
5607 "<unknown reason code>",
5608 "Administratively prohibited",
5609 "Connect failed",
5610 "Unknown channel type",
5611 "Resource shortage",
5612 };
5613 unsigned i = ssh_pkt_getuint32(pktin);
5614 unsigned reason_code;
5615 char *reason_string;
5616 int reason_length;
5617 char *message;
5618 struct ssh_channel *c;
5619 c = find234(ssh->channels, &i, ssh_channelfind);
5620 if (!c)
5621 return; /* nonexistent channel */
5622 if (c->type != CHAN_SOCKDATA_DORMANT)
5623 return; /* dunno why they're failing this */
5624
5625 reason_code = ssh_pkt_getuint32(pktin);
5626 if (reason_code >= lenof(reasons))
5627 reason_code = 0; /* ensure reasons[reason_code] in range */
5628 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5629 message = dupprintf("Forwarded connection refused by"
5630 " server: %s [%.*s]", reasons[reason_code],
5631 reason_length, reason_string);
5632 logevent(message);
5633 sfree(message);
5634
5635 pfd_close(c->u.pfd.s);
5636
5637 del234(ssh->channels, c);
5638 sfree(c);
5639}
5640
5641static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5642{
5643 unsigned localid;
5644 char *type;
5645 int typelen, want_reply;
5646 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5647 struct ssh_channel *c;
5648 struct Packet *pktout;
5649
5650 localid = ssh_pkt_getuint32(pktin);
5651 ssh_pkt_getstring(pktin, &type, &typelen);
5652 want_reply = ssh2_pkt_getbool(pktin);
5653
5654 /*
5655 * First, check that the channel exists. Otherwise,
5656 * we can instantly disconnect with a rude message.
5657 */
5658 c = find234(ssh->channels, &localid, ssh_channelfind);
5659 if (!c) {
5660 char buf[80];
5661 sprintf(buf, "Received channel request for nonexistent"
5662 " channel %d", localid);
5663 logevent(buf);
5664 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5665 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5666 ssh2_pkt_addstring(pktout, buf);
5667 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5668 ssh2_pkt_send_noqueue(ssh, pktout);
5669 connection_fatal(ssh->frontend, "%s", buf);
5670 ssh_closing((Plug)ssh, NULL, 0, 0);
5671 return;
5672 }
5673
5674 /*
5675 * Having got the channel number, we now look at
5676 * the request type string to see if it's something
5677 * we recognise.
5678 */
5679 if (c == ssh->mainchan) {
5680 /*
5681 * We recognise "exit-status" and "exit-signal" on
5682 * the primary channel.
5683 */
5684 if (typelen == 11 &&
5685 !memcmp(type, "exit-status", 11)) {
5686
5687 ssh->exitcode = ssh_pkt_getuint32(pktin);
5688 logeventf(ssh, "Server sent command exit status %d",
5689 ssh->exitcode);
5690 reply = SSH2_MSG_CHANNEL_SUCCESS;
5691
5692 } else if (typelen == 11 &&
5693 !memcmp(type, "exit-signal", 11)) {
5694
5695 int is_plausible = TRUE, is_int = FALSE;
5696 char *fmt_sig = "", *fmt_msg = "";
5697 char *msg;
5698 int msglen = 0, core = FALSE;
5699 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5700 * provide an `int' for the signal, despite its
5701 * having been a `string' in the drafts since at
5702 * least 2001. (Fixed in session.c 1.147.) Try to
5703 * infer which we can safely parse it as. */
5704 {
5705 unsigned char *p = pktin->body +
5706 pktin->savedpos;
5707 long len = pktin->length - pktin->savedpos;
5708 unsigned long num = GET_32BIT(p); /* what is it? */
5709 /* If it's 0, it hardly matters; assume string */
5710 if (num == 0) {
5711 is_int = FALSE;
5712 } else {
5713 int maybe_int = FALSE, maybe_str = FALSE;
5714#define CHECK_HYPOTHESIS(offset, result) \
5715 do { \
5716 long q = offset; \
5717 if (q >= 0 && q+4 <= len) { \
5718 q = q + 4 + GET_32BIT(p+q); \
5719 if (q >= 0 && q+4 <= len && \
5720 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5721 result = TRUE; \
5722 } \
5723 } while(0)
5724 CHECK_HYPOTHESIS(4+1, maybe_int);
5725 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5726#undef CHECK_HYPOTHESIS
5727 if (maybe_int && !maybe_str)
5728 is_int = TRUE;
5729 else if (!maybe_int && maybe_str)
5730 is_int = FALSE;
5731 else
5732 /* Crikey. Either or neither. Panic. */
5733 is_plausible = FALSE;
5734 }
5735 }
5736 if (is_plausible) {
5737 if (is_int) {
5738 /* Old non-standard OpenSSH. */
5739 int signum = ssh_pkt_getuint32(pktin);
5740 fmt_sig = dupprintf(" %d", signum);
5741 } else {
5742 /* As per the drafts. */
5743 char *sig;
5744 int siglen;
5745 ssh_pkt_getstring(pktin, &sig, &siglen);
5746 /* Signal name isn't supposed to be blank, but
5747 * let's cope gracefully if it is. */
5748 if (siglen) {
5749 fmt_sig = dupprintf(" \"%.*s\"",
5750 siglen, sig);
5751 }
5752 }
5753 core = ssh2_pkt_getbool(pktin);
5754 ssh_pkt_getstring(pktin, &msg, &msglen);
5755 if (msglen) {
5756 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5757 }
5758 /* ignore lang tag */
5759 } /* else don't attempt to parse */
5760 logeventf(ssh, "Server exited on signal%s%s%s",
5761 fmt_sig, core ? " (core dumped)" : "",
5762 fmt_msg);
5763 if (*fmt_sig) sfree(fmt_sig);
5764 if (*fmt_msg) sfree(fmt_msg);
5765 reply = SSH2_MSG_CHANNEL_SUCCESS;
5766
5767 }
5768 } else {
5769 /*
5770 * This is a channel request we don't know
5771 * about, so we now either ignore the request
5772 * or respond with CHANNEL_FAILURE, depending
5773 * on want_reply.
5774 */
5775 reply = SSH2_MSG_CHANNEL_FAILURE;
5776 }
5777 if (want_reply) {
5778 pktout = ssh2_pkt_init(reply);
5779 ssh2_pkt_adduint32(pktout, c->remoteid);
5780 ssh2_pkt_send(ssh, pktout);
5781 }
5782}
5783
5784static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5785{
5786 char *type;
5787 int typelen, want_reply;
5788 struct Packet *pktout;
5789
5790 ssh_pkt_getstring(pktin, &type, &typelen);
5791 want_reply = ssh2_pkt_getbool(pktin);
5792
5793 /*
5794 * We currently don't support any global requests
5795 * at all, so we either ignore the request or
5796 * respond with REQUEST_FAILURE, depending on
5797 * want_reply.
5798 */
5799 if (want_reply) {
5800 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5801 ssh2_pkt_send(ssh, pktout);
5802 }
5803}
5804
5805static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5806{
5807 char *type;
5808 int typelen;
5809 char *peeraddr;
5810 int peeraddrlen;
5811 int peerport;
5812 char *error = NULL;
5813 struct ssh_channel *c;
5814 unsigned remid, winsize, pktsize;
5815 struct Packet *pktout;
5816
5817 ssh_pkt_getstring(pktin, &type, &typelen);
5818 c = snew(struct ssh_channel);
5819 c->ssh = ssh;
5820
5821 remid = ssh_pkt_getuint32(pktin);
5822 winsize = ssh_pkt_getuint32(pktin);
5823 pktsize = ssh_pkt_getuint32(pktin);
5824
5825 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5826 char *addrstr;
5827
5828 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5829 addrstr = snewn(peeraddrlen+1, char);
5830 memcpy(addrstr, peeraddr, peeraddrlen);
5831 addrstr[peeraddrlen] = '\0';
5832 peerport = ssh_pkt_getuint32(pktin);
5833
5834 logeventf(ssh, "Received X11 connect request from %s:%d",
5835 addrstr, peerport);
5836
5837 if (!ssh->X11_fwd_enabled)
5838 error = "X11 forwarding is not enabled";
5839 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5840 ssh->x11auth, addrstr, peerport,
5841 &ssh->cfg) != NULL) {
5842 error = "Unable to open an X11 connection";
5843 } else {
5844 logevent("Opening X11 forward connection succeeded");
5845 c->type = CHAN_X11;
5846 }
5847
5848 sfree(addrstr);
5849 } else if (typelen == 15 &&
5850 !memcmp(type, "forwarded-tcpip", 15)) {
5851 struct ssh_rportfwd pf, *realpf;
5852 char *dummy;
5853 int dummylen;
5854 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5855 pf.sport = ssh_pkt_getuint32(pktin);
5856 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5857 peerport = ssh_pkt_getuint32(pktin);
5858 realpf = find234(ssh->rportfwds, &pf, NULL);
5859 logeventf(ssh, "Received remote port %d open request "
5860 "from %s:%d", pf.sport, peeraddr, peerport);
5861 if (realpf == NULL) {
5862 error = "Remote port is not recognised";
5863 } else {
5864 const char *e = pfd_newconnect(&c->u.pfd.s,
5865 realpf->dhost,
5866 realpf->dport, c,
05581745 5867 &ssh->cfg,
5868 realpf->pfrec->addressfamily);
51df0ab5 5869 logeventf(ssh, "Attempting to forward remote port to "
5870 "%s:%d", realpf->dhost, realpf->dport);
5871 if (e != NULL) {
5872 logeventf(ssh, "Port open failed: %s", e);
5873 error = "Port open failed";
5874 } else {
5875 logevent("Forwarded port opened successfully");
5876 c->type = CHAN_SOCKDATA;
5877 }
5878 }
5879 } else if (typelen == 22 &&
5880 !memcmp(type, "auth-agent@openssh.com", 3)) {
5881 if (!ssh->agentfwd_enabled)
5882 error = "Agent forwarding is not enabled";
5883 else {
5884 c->type = CHAN_AGENT; /* identify channel type */
5885 c->u.a.lensofar = 0;
5886 }
5887 } else {
5888 error = "Unsupported channel type requested";
5889 }
5890
5891 c->remoteid = remid;
5892 if (error) {
5893 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5894 ssh2_pkt_adduint32(pktout, c->remoteid);
5895 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5896 ssh2_pkt_addstring(pktout, error);
5897 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5898 ssh2_pkt_send(ssh, pktout);
5899 logeventf(ssh, "Rejected channel open: %s", error);
5900 sfree(c);
5901 } else {
5902 c->localid = alloc_channel_id(ssh);
5903 c->closes = 0;
5904 c->v.v2.locwindow = OUR_V2_WINSIZE;
5905 c->v.v2.remwindow = winsize;
5906 c->v.v2.remmaxpkt = pktsize;
5907 bufchain_init(&c->v.v2.outbuffer);
5908 add234(ssh->channels, c);
5909 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5910 ssh2_pkt_adduint32(pktout, c->remoteid);
5911 ssh2_pkt_adduint32(pktout, c->localid);
5912 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5913 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5914 ssh2_pkt_send(ssh, pktout);
5915 }
5916}
5917
783415f8 5918/*
7cca0d81 5919 * Handle the SSH2 userauth and connection layers.
5920 */
ff3187f6 5921static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5922 struct Packet *pktin)
7cca0d81 5923{
51470298 5924 struct do_ssh2_authconn_state {
5925 enum {
5926 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5927 AUTH_PASSWORD,
5928 AUTH_KEYBOARD_INTERACTIVE
5929 } method;
5930 enum {
5931 AUTH_TYPE_NONE,
5932 AUTH_TYPE_PUBLICKEY,
5933 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5934 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5935 AUTH_TYPE_PASSWORD,
5936 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5937 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5938 } type;
5939 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6ac3a551 5940 int tried_pubkey_config, tried_agent;
5941 int kbd_inter_running, kbd_inter_refused;
51470298 5942 int we_are_in;
5943 int num_prompts, curr_prompt, echo;
5944 char username[100];
5945 int got_username;
85fdbe25 5946 char pwprompt[512];
51470298 5947 char password[100];
5948 void *publickey_blob;
5949 int publickey_bloblen;
5950 unsigned char request[5], *response, *p;
5951 int responselen;
5952 int keyi, nkeys;
5953 int authed;
5954 char *pkblob, *alg, *commentp;
5955 int pklen, alglen, commentlen;
5956 int siglen, retlen, len;
5957 char *q, *agentreq, *ret;
5958 int try_send;
73feed4f 5959 int num_env, env_left, env_ok;
ff3187f6 5960 struct Packet *pktout;
51470298 5961 };
5962 crState(do_ssh2_authconn_state);
5963
5964 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 5965
7cca0d81 5966 /*
5967 * Request userauth protocol, and await a response to it.
5968 */
ff3187f6 5969 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5970 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5971 ssh2_pkt_send(ssh, s->pktout);
5972 crWaitUntilV(pktin);
5973 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 5974 bombout(("Server refused user authentication protocol"));
7ffdbc1a 5975 crStopV;
8d5de777 5976 }
7cca0d81 5977
5978 /*
1408a877 5979 * We repeat this whole loop, including the username prompt,
5980 * until we manage a successful authentication. If the user
51470298 5981 * types the wrong _password_, they can be sent back to the
5982 * beginning to try another username, if this is configured on.
5983 * (If they specify a username in the config, they are never
5984 * asked, even if they do give a wrong password.)
1408a877 5985 *
5986 * I think this best serves the needs of
5987 *
5988 * - the people who have no configuration, no keys, and just
5989 * want to try repeated (username,password) pairs until they
5990 * type both correctly
5991 *
5992 * - people who have keys and configuration but occasionally
5993 * need to fall back to passwords
5994 *
5995 * - people with a key held in Pageant, who might not have
5996 * logged in to a particular machine before; so they want to
5997 * type a username, and then _either_ their key will be
5998 * accepted, _or_ they will type a password. If they mistype
5999 * the username they will want to be able to get back and
6000 * retype it!
7cca0d81 6001 */
51470298 6002 s->username[0] = '\0';
6003 s->got_username = FALSE;
1408a877 6004 do {
1408a877 6005 /*
6006 * Get a username.
6007 */
86916870 6008 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 6009 /*
6010 * We got a username last time round this loop, and
6011 * with change_username turned off we don't try to get
6012 * it again.
6013 */
aa09f7d0 6014 } else if (!*ssh->cfg.username) {
c0a81592 6015 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 6016 if (!ssh_get_line("login as: ",
51470298 6017 s->username, sizeof(s->username), FALSE)) {
32874aea 6018 /*
6019 * get_line failed to get a username.
6020 * Terminate.
6021 */
6022 logevent("No username provided. Abandoning session.");
3bb2f322 6023 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6024 crStopV;
32874aea 6025 }
6026 } else {
51470298 6027 int ret; /* need not be saved across crReturn */
6028 c_write_str(ssh, "login as: ");
6029 ssh->send_ok = 1;
6030 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 6031 do {
ff3187f6 6032 crWaitUntilV(!pktin);
51470298 6033 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6034 } while (ret == 0);
6035 if (ret < 0)
6036 cleanup_exit(0);
4ca0c9d1 6037 c_write_str(ssh, "\r\n");
32874aea 6038 }
51470298 6039 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 6040 } else {
57356d63 6041 char *stuff;
86916870 6042 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 6043 s->username[sizeof(s->username)-1] = '\0';
65a22376 6044 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 6045 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 6046 c_write_str(ssh, stuff);
57356d63 6047 sfree(stuff);
7cca0d81 6048 }
6049 }
51470298 6050 s->got_username = TRUE;
7cca0d81 6051
65a22376 6052 /*
1408a877 6053 * Send an authentication request using method "none": (a)
6054 * just in case it succeeds, and (b) so that we know what
6055 * authentication methods we can usefully try next.
65a22376 6056 */
51470298 6057 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6058
ff3187f6 6059 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6060 ssh2_pkt_addstring(s->pktout, s->username);
6061 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6062 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6063 ssh2_pkt_send(ssh, s->pktout);
51470298 6064 s->type = AUTH_TYPE_NONE;
6065 s->gotit = FALSE;
6066 s->we_are_in = FALSE;
6067
6068 s->tried_pubkey_config = FALSE;
6069 s->tried_agent = FALSE;
51470298 6070 s->kbd_inter_running = FALSE;
6ac3a551 6071 s->kbd_inter_refused = FALSE;
86916870 6072 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 6073 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 6074 int keytype;
6c6d9ed9 6075 logeventf(ssh, "Reading private key file \"%.150s\"",
6076 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 6077 keytype = key_type(&ssh->cfg.keyfile);
51470298 6078 if (keytype == SSH_KEYTYPE_SSH2) {
6079 s->publickey_blob =
9a30e26b 6080 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 6081 &s->publickey_bloblen, NULL);
51470298 6082 } else {
57356d63 6083 char *msgbuf;
c2ad7d0d 6084 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 6085 key_type_to_str(keytype));
57356d63 6086 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 6087 " (%s)\r\n",
6088 filename_to_str(&ssh->cfg.keyfile),
57356d63 6089 key_type_to_str(keytype));
51470298 6090 c_write_str(ssh, msgbuf);
57356d63 6091 sfree(msgbuf);
51470298 6092 s->publickey_blob = NULL;
231ee168 6093 }
396778f1 6094 } else
51470298 6095 s->publickey_blob = NULL;
65a22376 6096
1408a877 6097 while (1) {
6098 /*
6099 * Wait for the result of the last authentication request.
6100 */
51470298 6101 if (!s->gotit)
ff3187f6 6102 crWaitUntilV(pktin);
6103 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 6104 char *banner;
6105 int size;
6106 /*
6107 * Don't show the banner if we're operating in
6108 * non-verbose non-interactive mode. (It's probably
6109 * a script, which means nobody will read the
6110 * banner _anyway_, and moreover the printing of
6111 * the banner will screw up processing on the
6112 * output of (say) plink.)
6113 */
6114 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 6115 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 6116 if (banner)
51470298 6117 c_write_untrusted(ssh, banner, size);
32874aea 6118 }
ff3187f6 6119 crWaitUntilV(pktin);
1408a877 6120 }
ff3187f6 6121 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6122 logevent("Access granted");
51470298 6123 s->we_are_in = TRUE;
1408a877 6124 break;
6125 }
65a22376 6126
51470298 6127 if (s->kbd_inter_running &&
ff3187f6 6128 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 6129 /*
45068b27 6130 * This is either a further set-of-prompts packet
6131 * in keyboard-interactive authentication, or it's
6132 * the same one and we came back here with `gotit'
6133 * set. In the former case, we must reset the
6134 * curr_prompt variable.
b3186d64 6135 */
51470298 6136 if (!s->gotit)
6137 s->curr_prompt = 0;
4c6e53e3 6138 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6139 /* FIXME: perhaps we should support this? */
6140 bombout(("PASSWD_CHANGEREQ not yet supported"));
6141 crStopV;
ff3187f6 6142 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 6143 bombout(("Strange packet received during authentication: type %d",
ff3187f6 6144 pktin->type));
7ffdbc1a 6145 crStopV;
65a22376 6146 }
6147
51470298 6148 s->gotit = FALSE;
65a22376 6149
1408a877 6150 /*
6151 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6152 * we can look at the string in it and know what we can
6153 * helpfully try next.
6154 */
ff3187f6 6155 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6156 char *methods;
6157 int methlen;
ff3187f6 6158 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 6159 s->kbd_inter_running = FALSE;
ff3187f6 6160 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6161 /*
6162 * We have received an unequivocal Access
6163 * Denied. This can translate to a variety of
6164 * messages:
6165 *
6166 * - if we'd just tried "none" authentication,
6167 * it's not worth printing anything at all
6168 *
6169 * - if we'd just tried a public key _offer_,
6170 * the message should be "Server refused our
6171 * key" (or no message at all if the key
6172 * came from Pageant)
6173 *
6174 * - if we'd just tried anything else, the
6175 * message really should be "Access denied".
6176 *
6177 * Additionally, if we'd just tried password
6178 * authentication, we should break out of this
6179 * whole loop so as to go back to the username
91f57d1f 6180 * prompt (iff we're configured to allow
6181 * username change attempts).
1408a877 6182 */
51470298 6183 if (s->type == AUTH_TYPE_NONE) {
1408a877 6184 /* do nothing */
51470298 6185 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6186 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6187 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6188 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6189 logevent("Server refused public key");
51470298 6190 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6191 /* server declined keyboard-interactive; ignore */
1408a877 6192 } else {
51470298 6193 c_write_str(ssh, "Access denied\r\n");
1408a877 6194 logevent("Access denied");
91f57d1f 6195 if (s->type == AUTH_TYPE_PASSWORD &&
6196 ssh->cfg.change_username) {
6c9dce7c 6197 /* XXX perhaps we should allow
6198 * keyboard-interactive to do this too? */
51470298 6199 s->we_are_in = FALSE;
1408a877 6200 break;
6201 }
6202 }
6203 } else {
51470298 6204 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6205 logevent("Further authentication required");
6206 }
65a22376 6207
51470298 6208 s->can_pubkey =
32874aea 6209 in_commasep_string("publickey", methods, methlen);
51470298 6210 s->can_passwd =
32874aea 6211 in_commasep_string("password", methods, methlen);
86916870 6212 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6213 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6214 }
65a22376 6215
51470298 6216 s->method = 0;
6217 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 6218 s->need_pw = FALSE;
65a22376 6219
0405e71f 6220 /*
6221 * Most password/passphrase prompts will be
6222 * non-echoing, so we set this to 0 by default.
6223 * Exception is that some keyboard-interactive prompts
6224 * can be echoing, in which case we'll set this to 1.
6225 */
51470298 6226 s->echo = 0;
0405e71f 6227
51470298 6228 if (!s->method && s->can_pubkey &&
6229 agent_exists() && !s->tried_agent) {
1983e559 6230 /*
6231 * Attempt public-key authentication using Pageant.
6232 */
1983e559 6233 void *r;
51470298 6234 s->authed = FALSE;
1983e559 6235
51470298 6236 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6237 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6238
51470298 6239 s->tried_agent = TRUE;
1983e559 6240
6241 logevent("Pageant is running. Requesting keys.");
6242
6243 /* Request the keys held by the agent. */
51470298 6244 PUT_32BIT(s->request, 1);
6245 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 6246 if (!agent_query(s->request, 5, &r, &s->responselen,
6247 ssh_agent_callback, ssh)) {
6248 do {
6249 crReturnV;
ff3187f6 6250 if (pktin) {
839f10db 6251 bombout(("Unexpected data from server while"
6252 " waiting for agent response"));
6253 crStopV;
6254 }
ff3187f6 6255 } while (pktin || inlen > 0);
839f10db 6256 r = ssh->agent_response;
6257 s->responselen = ssh->agent_response_len;
6258 }
51470298 6259 s->response = (unsigned char *) r;
6260 if (s->response && s->responselen >= 5 &&
6261 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6262 s->p = s->response + 5;
6263 s->nkeys = GET_32BIT(s->p);
6264 s->p += 4;
32874aea 6265 {
6266 char buf[64];
51470298 6267 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 6268 logevent(buf);
6269 }
51470298 6270 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 6271 void *vret;
1983e559 6272
32874aea 6273 {
6274 char buf[64];
51470298 6275 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 6276 logevent(buf);
6277 }
51470298 6278 s->pklen = GET_32BIT(s->p);
6279 s->p += 4;
6280 if (s->publickey_blob &&
6281 s->pklen == s->publickey_bloblen &&
6282 !memcmp(s->p, s->publickey_blob,
6283 s->publickey_bloblen)) {
396778f1 6284 logevent("This key matches configured key file");
51470298 6285 s->tried_pubkey_config = 1;
396778f1 6286 }
d8baa528 6287 s->pkblob = (char *)s->p;
51470298 6288 s->p += s->pklen;
6289 s->alglen = GET_32BIT(s->pkblob);
6290 s->alg = s->pkblob + 4;
6291 s->commentlen = GET_32BIT(s->p);
6292 s->p += 4;
d8baa528 6293 s->commentp = (char *)s->p;
51470298 6294 s->p += s->commentlen;
ff3187f6 6295 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6296 ssh2_pkt_addstring(s->pktout, s->username);
6297 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6298 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6299 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6300 ssh2_pkt_addstring_start(s->pktout);
6301 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6302 ssh2_pkt_addstring_start(s->pktout);
6303 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6304 ssh2_pkt_send(ssh, s->pktout);
6305
6306 crWaitUntilV(pktin);
6307 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6308 logevent("Key refused");
6309 continue;
6310 }
6311
32874aea 6312 if (flags & FLAG_VERBOSE) {
51470298 6313 c_write_str(ssh, "Authenticating with "
6314 "public key \"");
6315 c_write(ssh, s->commentp, s->commentlen);
6316 c_write_str(ssh, "\" from agent\r\n");
32874aea 6317 }
1983e559 6318
6319 /*
6320 * Server is willing to accept the key.
6321 * Construct a SIGN_REQUEST.
6322 */
ff3187f6 6323 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6324 ssh2_pkt_addstring(s->pktout, s->username);
6325 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6326 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6327 ssh2_pkt_addbool(s->pktout, TRUE);
6328 ssh2_pkt_addstring_start(s->pktout);
6329 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6330 ssh2_pkt_addstring_start(s->pktout);
6331 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6332
6333 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 6334 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6335 s->siglen -= 4;
51470298 6336 s->len = 1; /* message type */
6337 s->len += 4 + s->pklen; /* key blob */
6338 s->len += 4 + s->siglen; /* data to sign */
6339 s->len += 4; /* flags */
3d88e64d 6340 s->agentreq = snewn(4 + s->len, char);
51470298 6341 PUT_32BIT(s->agentreq, s->len);
6342 s->q = s->agentreq + 4;
6343 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6344 PUT_32BIT(s->q, s->pklen);
6345 s->q += 4;
6346 memcpy(s->q, s->pkblob, s->pklen);
6347 s->q += s->pklen;
6348 PUT_32BIT(s->q, s->siglen);
6349 s->q += 4;
1983e559 6350 /* Now the data to be signed... */
dda87a28 6351 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6352 PUT_32BIT(s->q, 20);
6353 s->q += 4;
6354 }
51470298 6355 memcpy(s->q, ssh->v2_session_id, 20);
6356 s->q += 20;
ff3187f6 6357 memcpy(s->q, s->pktout->data + 5,
6358 s->pktout->length - 5);
6359 s->q += s->pktout->length - 5;
1983e559 6360 /* And finally the (zero) flags word. */
51470298 6361 PUT_32BIT(s->q, 0);
839f10db 6362 if (!agent_query(s->agentreq, s->len + 4,
6363 &vret, &s->retlen,
6364 ssh_agent_callback, ssh)) {
6365 do {
6366 crReturnV;
ff3187f6 6367 if (pktin) {
839f10db 6368 bombout(("Unexpected data from server"
6369 " while waiting for agent"
6370 " response"));
6371 crStopV;
6372 }
ff3187f6 6373 } while (pktin || inlen > 0);
839f10db 6374 vret = ssh->agent_response;
6375 s->retlen = ssh->agent_response_len;
6376 }
51470298 6377 s->ret = vret;
6378 sfree(s->agentreq);
6379 if (s->ret) {
6380 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 6381 logevent("Sending Pageant's response");
ff3187f6 6382 ssh2_add_sigblob(ssh, s->pktout,
6383 s->pkblob, s->pklen,
51470298 6384 s->ret + 9,
6385 GET_32BIT(s->ret + 5));
ff3187f6 6386 ssh2_pkt_send(ssh, s->pktout);
51470298 6387 s->authed = TRUE;
1983e559 6388 break;
6389 } else {
32874aea 6390 logevent
6391 ("Pageant failed to answer challenge");
51470298 6392 sfree(s->ret);
1983e559 6393 }
6394 }
6395 }
51470298 6396 if (s->authed)
1983e559 6397 continue;
6398 }
29b1d0b3 6399 sfree(s->response);
1983e559 6400 }
6401
51470298 6402 if (!s->method && s->can_pubkey && s->publickey_blob
6403 && !s->tried_pubkey_config) {
1408a877 6404 unsigned char *pub_blob;
6405 char *algorithm, *comment;
6406 int pub_blob_len;
65a22376 6407
51470298 6408 s->tried_pubkey_config = TRUE;
65a22376 6409
51470298 6410 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6411 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6412
65a22376 6413 /*
1408a877 6414 * Try the public key supplied in the configuration.
6415 *
6416 * First, offer the public blob to see if the server is
6417 * willing to accept it.
65a22376 6418 */
d8baa528 6419 pub_blob =
9a30e26b 6420 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6421 &algorithm,
222d54dc 6422 &pub_blob_len,
6423 NULL);
1408a877 6424 if (pub_blob) {
ff3187f6 6425 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6426 ssh2_pkt_addstring(s->pktout, s->username);
6427 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6428 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6429 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6430 ssh2_pkt_addstring(s->pktout, algorithm);
6431 ssh2_pkt_addstring_start(s->pktout);
6432 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6433 pub_blob_len);
ff3187f6 6434 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6435 logevent("Offered public key");
1408a877 6436
ff3187f6 6437 crWaitUntilV(pktin);
6438 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6439 s->gotit = TRUE;
6440 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6441 continue; /* key refused; give up on it */
1408a877 6442 }
65a22376 6443
1408a877 6444 logevent("Offer of public key accepted");
65a22376 6445 /*
1408a877 6446 * Actually attempt a serious authentication using
6447 * the key.
65a22376 6448 */
9a30e26b 6449 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6450 sprintf(s->pwprompt,
32874aea 6451 "Passphrase for key \"%.100s\": ",
6452 comment);
51470298 6453 s->need_pw = TRUE;
1408a877 6454 } else {
51470298 6455 s->need_pw = FALSE;
1408a877 6456 }
4e520718 6457 if (flags & FLAG_VERBOSE) {
6458 c_write_str(ssh, "Authenticating with public key \"");
6459 c_write_str(ssh, comment);
6460 c_write_str(ssh, "\"\r\n");
6461 }
51470298 6462 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6463 }
1408a877 6464 }
6465
6f64ce13 6466 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6467 !s->kbd_inter_running) {
51470298 6468 s->method = AUTH_KEYBOARD_INTERACTIVE;
6469 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6470
51470298 6471 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6472 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6473
ff3187f6 6474 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6475 ssh2_pkt_addstring(s->pktout, s->username);
6476 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6477 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6478 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6479 ssh2_pkt_addstring(s->pktout, "");
6480 ssh2_pkt_send(ssh, s->pktout);
6481
6482 crWaitUntilV(pktin);
6483 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6484 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6485 s->gotit = TRUE;
af659722 6486 logevent("Keyboard-interactive authentication refused");
51470298 6487 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6ac3a551 6488 s->kbd_inter_refused = TRUE; /* don't try it again */
af659722 6489 continue;
6490 }
6491
51470298 6492 s->kbd_inter_running = TRUE;
6493 s->curr_prompt = 0;
af659722 6494 }
6495
51470298 6496 if (s->kbd_inter_running) {
6497 s->method = AUTH_KEYBOARD_INTERACTIVE;
6498 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6499
51470298 6500 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6501 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6502
51470298 6503 if (s->curr_prompt == 0) {
45068b27 6504 /*
6505 * We've got a fresh USERAUTH_INFO_REQUEST.
6506 * Display header data, and start going through
6507 * the prompts.
6508 */
6509 char *name, *inst, *lang;
6510 int name_len, inst_len, lang_len;
6511
ff3187f6 6512 ssh_pkt_getstring(pktin, &name, &name_len);
6513 ssh_pkt_getstring(pktin, &inst, &inst_len);
6514 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6515 if (name_len > 0) {
51470298 6516 c_write_untrusted(ssh, name, name_len);
6517 c_write_str(ssh, "\r\n");
45068b27 6518 }
6519 if (inst_len > 0) {
51470298 6520 c_write_untrusted(ssh, inst, inst_len);
6521 c_write_str(ssh, "\r\n");
45068b27 6522 }
ff3187f6 6523 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6524 }
af659722 6525
45068b27 6526 /*
6527 * If there are prompts remaining in the packet,
6528 * display one and get a response.
6529 */
51470298 6530 if (s->curr_prompt < s->num_prompts) {
45068b27 6531 char *prompt;
6532 int prompt_len;
af659722 6533
ff3187f6 6534 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6535 if (prompt_len > 0) {
85fdbe25 6536 static const char trunc[] = "<prompt truncated>: ";
6537 static const int prlen = sizeof(s->pwprompt) -
6538 lenof(trunc);
6539 if (prompt_len > prlen) {
6540 memcpy(s->pwprompt, prompt, prlen);
6541 strcpy(s->pwprompt + prlen, trunc);
6542 } else {
6543 memcpy(s->pwprompt, prompt, prompt_len);
6544 s->pwprompt[prompt_len] = '\0';
6545 }
45068b27 6546 } else {
51470298 6547 strcpy(s->pwprompt,
45068b27 6548 "<server failed to send prompt>: ");
6549 }
ff3187f6 6550 s->echo = ssh2_pkt_getbool(pktin);
51470298 6551 s->need_pw = TRUE;
45068b27 6552 } else
51470298 6553 s->need_pw = FALSE;
af659722 6554 }
6555
51470298 6556 if (!s->method && s->can_passwd) {
6557 s->method = AUTH_PASSWORD;
6558 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6559 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6560 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6561 ssh->savedhost);
6562 s->need_pw = TRUE;
1408a877 6563 }
6564
51470298 6565 if (s->need_pw) {
fa17a66e 6566 if (ssh_get_line) {
51470298 6567 if (!ssh_get_line(s->pwprompt, s->password,
6568 sizeof(s->password), TRUE)) {
1408a877 6569 /*
fa17a66e 6570 * get_line failed to get a password (for
6571 * example because one was supplied on the
6572 * command line which has already failed to
6573 * work). Terminate.
1408a877 6574 */
ff3187f6 6575 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6576 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6577 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6578 " to try");
ff3187f6 6579 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6580 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6581 logevent("Unable to authenticate");
a8327734 6582 connection_fatal(ssh->frontend,
6583 "Unable to authenticate");
3bb2f322 6584 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6585 crStopV;
1408a877 6586 }
6587 } else {
51470298 6588 int ret; /* need not be saved across crReturn */
6589 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6590 ssh->send_ok = 1;
1408a877 6591
51470298 6592 setup_userpass_input(ssh, s->password,
6593 sizeof(s->password), s->echo);
0405e71f 6594 do {
ff3187f6 6595 crWaitUntilV(!pktin);
51470298 6596 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6597 } while (ret == 0);
6598 if (ret < 0)
6599 cleanup_exit(0);
51470298 6600 c_write_str(ssh, "\r\n");
65a22376 6601 }
65a22376 6602 }
65a22376 6603
51470298 6604 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6605 /*
6606 * We have our passphrase. Now try the actual authentication.
6607 */
6608 struct ssh2_userkey *key;
222d54dc 6609 const char *error = NULL;
65a22376 6610
222d54dc 6611 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6612 &error);
1408a877 6613 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6614 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6615 c_write_str(ssh, "Wrong passphrase\r\n");
6616 s->tried_pubkey_config = FALSE;
1408a877 6617 } else {
222d54dc 6618 c_write_str(ssh, "Unable to load private key (");
6619 c_write_str(ssh, error);
6620 c_write_str(ssh, ")\r\n");
51470298 6621 s->tried_pubkey_config = TRUE;
1408a877 6622 }
6623 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6624 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6625 ssh2_pkt_addstring(s->pktout, s->username);
6626 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6627 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6628 ssh2_pkt_send(ssh, s->pktout);
51470298 6629 s->type = AUTH_TYPE_NONE;
1408a877 6630 } else {
1dd353b5 6631 unsigned char *pkblob, *sigblob, *sigdata;
6632 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6633 int p;
65a22376 6634
1408a877 6635 /*
6636 * We have loaded the private key and the server
6637 * has announced that it's willing to accept it.
6638 * Hallelujah. Generate a signature and send it.
6639 */
ff3187f6 6640 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6641 ssh2_pkt_addstring(s->pktout, s->username);
6642 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6643 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6644 ssh2_pkt_addbool(s->pktout, TRUE);
6645 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6646 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6647 ssh2_pkt_addstring_start(s->pktout);
6648 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6649
6650 /*
6651 * The data to be signed is:
6652 *
6653 * string session-id
6654 *
6655 * followed by everything so far placed in the
6656 * outgoing packet.
6657 */
ff3187f6 6658 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6659 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6660 sigdata_len -= 4;
92d60585 6661 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6662 p = 0;
6663 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6664 PUT_32BIT(sigdata+p, 20);
6665 p += 4;
6666 }
6667 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6668 memcpy(sigdata+p, s->pktout->data + 5,
6669 s->pktout->length - 5);
6670 p += s->pktout->length - 5;
dda87a28 6671 assert(p == sigdata_len);
d8baa528 6672 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6673 sigdata_len, &sigblob_len);
ff3187f6 6674 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6675 sigblob, sigblob_len);
6676 sfree(pkblob);
6677 sfree(sigblob);
1408a877 6678 sfree(sigdata);
6679
ff3187f6 6680 ssh2_pkt_send(ssh, s->pktout);
51470298 6681 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6682 key->alg->freekey(key->data);
1408a877 6683 }
51470298 6684 } else if (s->method == AUTH_PASSWORD) {
65a22376 6685 /*
1408a877 6686 * We send the password packet lumped tightly together with
6687 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6688 * string long enough to make the total length of the two
6689 * packets constant. This should ensure that a passive
6690 * listener doing traffic analyis can't work out the length
6691 * of the password.
6692 *
6693 * For this to work, we need an assumption about the
6694 * maximum length of the password packet. I think 256 is
6695 * pretty conservative. Anyone using a password longer than
6696 * that probably doesn't have much to worry about from
6697 * people who find out how long their password is!
65a22376 6698 */
ff3187f6 6699 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6700 ssh2_pkt_addstring(s->pktout, s->username);
6701 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6702 ssh2_pkt_addstring(s->pktout, "password");
6703 ssh2_pkt_addbool(s->pktout, FALSE);
6704 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6705 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 6706 memset(s->password, 0, sizeof(s->password));
ff3187f6 6707 end_log_omission(ssh, s->pktout);
6708 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6709 /*
1408a877 6710 * We'll include a string that's an exact multiple of the
6711 * cipher block size. If the cipher is NULL for some
6712 * reason, we don't do this trick at all because we gain
6713 * nothing by it.
65a22376 6714 */
51470298 6715 if (ssh->cscipher) {
32874aea 6716 int stringlen, i;
6717
51470298 6718 stringlen = (256 - ssh->deferred_len);
6719 stringlen += ssh->cscipher->blksize - 1;
6720 stringlen -= (stringlen % ssh->cscipher->blksize);
6721 if (ssh->cscomp) {
32874aea 6722 /*
6723 * Temporarily disable actual compression,
6724 * so we can guarantee to get this string
6725 * exactly the length we want it. The
6726 * compression-disabling routine should
6727 * return an integer indicating how many
6728 * bytes we should adjust our string length
6729 * by.
6730 */
5366aed8 6731 stringlen -=
6732 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 6733 }
ff3187f6 6734 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6735 ssh2_pkt_addstring_start(s->pktout);
6e9e9520 6736 for (i = 0; i < stringlen; i++) {
32874aea 6737 char c = (char) random_byte();
ff3187f6 6738 ssh2_pkt_addstring_data(s->pktout, &c, 1);
65a22376 6739 }
ff3187f6 6740 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6741 }
51470298 6742 ssh_pkt_defersend(ssh);
0d43337a 6743 logevent("Sent password");
51470298 6744 s->type = AUTH_TYPE_PASSWORD;
6745 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6746 if (s->curr_prompt == 0) {
ff3187f6 6747 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6748 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 6749 }
51470298 6750 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 6751 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6752 ssh2_pkt_addstring(s->pktout, s->password);
51470298 6753 memset(s->password, 0, sizeof(s->password));
ff3187f6 6754 end_log_omission(ssh, s->pktout);
51470298 6755 s->curr_prompt++;
45068b27 6756 }
51470298 6757 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 6758 ssh2_pkt_send(ssh, s->pktout);
45068b27 6759 } else {
6760 /*
6761 * If there are prompts remaining, we set
6762 * `gotit' so that we won't attempt to get
6763 * another packet. Then we go back round the
6764 * loop and will end up retrieving another
6765 * prompt out of the existing packet. Funky or
6766 * what?
6767 */
51470298 6768 s->gotit = TRUE;
45068b27 6769 }
51470298 6770 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 6771 } else {
51470298 6772 c_write_str(ssh, "No supported authentication methods"
6773 " left to try!\r\n");
6774 logevent("No supported authentications offered."
6775 " Disconnecting");
ff3187f6 6776 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6777 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6778 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 6779 " methods available");
ff3187f6 6780 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6781 ssh2_pkt_send_noqueue(ssh, s->pktout);
3bb2f322 6782 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6783 crStopV;
65a22376 6784 }
65a22376 6785 }
51470298 6786 } while (!s->we_are_in);
7cca0d81 6787
6788 /*
6789 * Now we're authenticated for the connection protocol. The
6790 * connection protocol will automatically have started at this
6791 * point; there's no need to send SERVICE_REQUEST.
6792 */
6793
0ed48730 6794 ssh->channels = newtree234(ssh_channelcmp);
6795
7cca0d81 6796 /*
b09eaa88 6797 * Set up handlers for some connection protocol messages, so we
6798 * don't have to handle them repeatedly in this coroutine.
6799 */
6800 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6801 ssh2_msg_channel_window_adjust;
51df0ab5 6802 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6803 ssh2_msg_global_request;
b09eaa88 6804
6805 /*
0ed48730 6806 * Create the main session channel.
7cca0d81 6807 */
0ed48730 6808 if (!ssh->cfg.ssh_no_shell) {
6809 ssh->mainchan = snew(struct ssh_channel);
6810 ssh->mainchan->ssh = ssh;
6811 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 6812 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6813 ssh2_pkt_addstring(s->pktout, "session");
6814 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 6815 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 6816 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6817 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6818 ssh2_pkt_send(ssh, s->pktout);
6819 crWaitUntilV(pktin);
6820 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 6821 bombout(("Server refused to open a session"));
6822 crStopV;
6823 /* FIXME: error data comes back in FAILURE packet */
6824 }
ff3187f6 6825 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 6826 bombout(("Server's channel confirmation cited wrong channel"));
6827 crStopV;
6828 }
ff3187f6 6829 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 6830 ssh->mainchan->type = CHAN_MAINSESSION;
6831 ssh->mainchan->closes = 0;
ff3187f6 6832 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6833 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 6834 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6835 add234(ssh->channels, ssh->mainchan);
62638676 6836 update_specials_menu(ssh->frontend);
0ed48730 6837 logevent("Opened channel for session");
6838 } else
6839 ssh->mainchan = NULL;
7cca0d81 6840
6841 /*
51df0ab5 6842 * Now we have a channel, make dispatch table entries for
6843 * general channel-based messages.
6844 */
6845 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6846 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6847 ssh2_msg_channel_data;
6848 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6849 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6850 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6851 ssh2_msg_channel_open_confirmation;
6852 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6853 ssh2_msg_channel_open_failure;
6854 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6855 ssh2_msg_channel_request;
6856 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6857 ssh2_msg_channel_open;
6858
6859 /*
783415f8 6860 * Potentially enable X11 forwarding.
6861 */
0ed48730 6862 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 6863 char proto[20], data[64];
6864 logevent("Requesting X11 forwarding");
302121de 6865 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 6866 data, sizeof(data), ssh->cfg.x11_auth);
6867 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 6868 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6869 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6870 ssh2_pkt_addstring(s->pktout, "x11-req");
6871 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6872 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6873 ssh2_pkt_addstring(s->pktout, proto);
6874 ssh2_pkt_addstring(s->pktout, data);
6875 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6876 ssh2_pkt_send(ssh, s->pktout);
32874aea 6877
b09eaa88 6878 crWaitUntilV(pktin);
32874aea 6879
ff3187f6 6880 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6881 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6882 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 6883 " packet type %d", pktin->type));
7ffdbc1a 6884 crStopV;
32874aea 6885 }
6886 logevent("X11 forwarding refused");
6887 } else {
6888 logevent("X11 forwarding enabled");
51470298 6889 ssh->X11_fwd_enabled = TRUE;
32874aea 6890 }
783415f8 6891 }
6892
6893 /*
bc240b21 6894 * Enable port forwardings.
6895 */
06fadff5 6896 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 6897
6898 /*
36c2a3e9 6899 * Potentially enable agent forwarding.
6900 */
0ed48730 6901 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6902 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6903 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6904 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6905 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6906 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6907 ssh2_pkt_send(ssh, s->pktout);
32874aea 6908
b09eaa88 6909 crWaitUntilV(pktin);
32874aea 6910
ff3187f6 6911 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6912 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6913 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6914 " packet type %d", pktin->type));
7ffdbc1a 6915 crStopV;
32874aea 6916 }
6917 logevent("Agent forwarding refused");
6918 } else {
6919 logevent("Agent forwarding enabled");
51470298 6920 ssh->agentfwd_enabled = TRUE;
32874aea 6921 }
36c2a3e9 6922 }
6923
6924 /*
7cca0d81 6925 * Now allocate a pty for the session.
6926 */
0ed48730 6927 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6928 /* Unpick the terminal-speed string. */
6929 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6930 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6931 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6932 /* Build the pty request. */
ff3187f6 6933 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6934 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6935 ssh2_pkt_addstring(s->pktout, "pty-req");
6936 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6937 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6938 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6939 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6940 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6941 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6942 ssh2_pkt_addstring_start(s->pktout);
6943 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6944 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6945 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6946 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6947 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6948 ssh2_pkt_send(ssh, s->pktout);
51470298 6949 ssh->state = SSH_STATE_INTERMED;
32874aea 6950
b09eaa88 6951 crWaitUntilV(pktin);
32874aea 6952
ff3187f6 6953 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6954 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6955 bombout(("Unexpected response to pty request:"
ff3187f6 6956 " packet type %d", pktin->type));
7ffdbc1a 6957 crStopV;
32874aea 6958 }
51470298 6959 c_write_str(ssh, "Server refused to allocate pty\r\n");
6960 ssh->editing = ssh->echoing = 1;
32874aea 6961 } else {
a5dd8467 6962 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 6963 ssh->ospeed, ssh->ispeed);
32874aea 6964 }
0965bee0 6965 } else {
51470298 6966 ssh->editing = ssh->echoing = 1;
7cca0d81 6967 }
6968
6969 /*
73feed4f 6970 * Send environment variables.
6971 *
6972 * Simplest thing here is to send all the requests at once, and
6973 * then wait for a whole bunch of successes or failures.
6974 */
6975 if (ssh->mainchan && *ssh->cfg.environmt) {
6976 char *e = ssh->cfg.environmt;
6977 char *var, *varend, *val;
6978
6979 s->num_env = 0;
6980
6981 while (*e) {
6982 var = e;
6983 while (*e && *e != '\t') e++;
6984 varend = e;
6985 if (*e == '\t') e++;
6986 val = e;
6987 while (*e) e++;
6988 e++;
6989
ff3187f6 6990 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6991 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6992 ssh2_pkt_addstring(s->pktout, "env");
6993 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6994 ssh2_pkt_addstring_start(s->pktout);
6995 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6996 ssh2_pkt_addstring(s->pktout, val);
6997 ssh2_pkt_send(ssh, s->pktout);
73feed4f 6998
6999 s->num_env++;
7000 }
7001
7002 logeventf(ssh, "Sent %d environment variables", s->num_env);
7003
7004 s->env_ok = 0;
7005 s->env_left = s->num_env;
7006
7007 while (s->env_left > 0) {
b09eaa88 7008 crWaitUntilV(pktin);
73feed4f 7009
ff3187f6 7010 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7011 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 7012 bombout(("Unexpected response to environment request:"
ff3187f6 7013 " packet type %d", pktin->type));
73feed4f 7014 crStopV;
7015 }
7016 } else {
7017 s->env_ok++;
7018 }
7019
7020 s->env_left--;
7021 }
7022
7023 if (s->env_ok == s->num_env) {
7024 logevent("All environment variables successfully set");
7025 } else if (s->env_ok == 0) {
7026 logevent("All environment variables refused");
7027 c_write_str(ssh, "Server refused to set environment variables\r\n");
7028 } else {
7029 logeventf(ssh, "%d environment variables refused",
7030 s->num_env - s->env_ok);
7031 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7032 }
7033 }
7034
7035 /*
fd5e5847 7036 * Start a shell or a remote command. We may have to attempt
7037 * this twice if the config data has provided a second choice
7038 * of command.
7cca0d81 7039 */
0ed48730 7040 if (ssh->mainchan) while (1) {
fd5e5847 7041 int subsys;
7042 char *cmd;
7043
51470298 7044 if (ssh->fallback_cmd) {
86916870 7045 subsys = ssh->cfg.ssh_subsys2;
7046 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 7047 } else {
86916870 7048 subsys = ssh->cfg.ssh_subsys;
7049 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 7050 }
7051
ff3187f6 7052 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7053 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 7054 if (subsys) {
ff3187f6 7055 ssh2_pkt_addstring(s->pktout, "subsystem");
7056 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7057 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7058 } else if (*cmd) {
ff3187f6 7059 ssh2_pkt_addstring(s->pktout, "exec");
7060 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7061 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7062 } else {
ff3187f6 7063 ssh2_pkt_addstring(s->pktout, "shell");
7064 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 7065 }
ff3187f6 7066 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 7067
7068 crWaitUntilV(pktin);
7069
ff3187f6 7070 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7071 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7072 bombout(("Unexpected response to shell/command request:"
ff3187f6 7073 " packet type %d", pktin->type));
7ffdbc1a 7074 crStopV;
fd5e5847 7075 }
7076 /*
7077 * We failed to start the command. If this is the
7078 * fallback command, we really are finished; if it's
7079 * not, and if the fallback command exists, try falling
7080 * back to it before complaining.
7081 */
86916870 7082 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7083 logevent("Primary command failed; attempting fallback");
51470298 7084 ssh->fallback_cmd = TRUE;
fd5e5847 7085 continue;
7086 }
6b5cf8b4 7087 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7088 crStopV;
fd5e5847 7089 } else {
7090 logevent("Started a shell/command");
32874aea 7091 }
fd5e5847 7092 break;
7cca0d81 7093 }
7094
51470298 7095 ssh->state = SSH_STATE_SESSION;
7096 if (ssh->size_needed)
7097 ssh_size(ssh, ssh->term_width, ssh->term_height);
7098 if (ssh->eof_needed)
7099 ssh_special(ssh, TS_EOF);
6e48c3fe 7100
7cca0d81 7101 /*
7102 * Transfer data!
7103 */
b9d7bcad 7104 if (ssh->ldisc)
7105 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7106 if (ssh->mainchan)
7107 ssh->send_ok = 1;
7cca0d81 7108 while (1) {
e5574168 7109 crReturnV;
51470298 7110 s->try_send = FALSE;
ff3187f6 7111 if (pktin) {
2b7540a7 7112
51df0ab5 7113 /*
7114 * _All_ the connection-layer packets we expect to
7115 * receive are now handled by the dispatch table.
7116 * Anything that reaches here must be bogus.
7117 */
32874aea 7118
51df0ab5 7119 bombout(("Strange packet received: type %d", pktin->type));
7120 crStopV;
0ed48730 7121 } else if (ssh->mainchan) {
32874aea 7122 /*
7123 * We have spare data. Add it to the channel buffer.
7124 */
d8baa528 7125 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7126 s->try_send = TRUE;
32874aea 7127 }
51470298 7128 if (s->try_send) {
32874aea 7129 int i;
7130 struct ssh_channel *c;
7131 /*
7132 * Try to send data on all channels if we can.
7133 */
51470298 7134 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 7135 int bufsize;
7136 if (c->closes)
7137 continue; /* don't send on closing channels */
7138 bufsize = ssh2_try_send(c);
5471d09a 7139 if (bufsize == 0) {
7140 switch (c->type) {
7141 case CHAN_MAINSESSION:
7142 /* stdin need not receive an unthrottle
7143 * notification since it will be polled */
7144 break;
7145 case CHAN_X11:
7146 x11_unthrottle(c->u.x11.s);
7147 break;
7148 case CHAN_AGENT:
7149 /* agent sockets are request/response and need no
7150 * buffer management */
7151 break;
7152 case CHAN_SOCKDATA:
7153 pfd_unthrottle(c->u.pfd.s);
7154 break;
7155 }
7156 }
7157 }
7cca0d81 7158 }
e5574168 7159 }
7160
7161 crFinishV;
7162}
7163
7164/*
b09eaa88 7165 * Handlers for SSH2 messages that might arrive at any moment.
7166 */
7167void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7168{
7169 /* log reason code in disconnect message */
7170 char *buf, *msg;
7171 int nowlen, reason, msglen;
7172
7173 reason = ssh_pkt_getuint32(pktin);
7174 ssh_pkt_getstring(pktin, &msg, &msglen);
7175
7176 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7177 buf = dupprintf("Received disconnect message (%s)",
7178 ssh2_disconnect_reasons[reason]);
7179 } else {
7180 buf = dupprintf("Received disconnect message (unknown"
7181 " type %d)", reason);
7182 }
7183 logevent(buf);
7184 sfree(buf);
7185 buf = dupprintf("Disconnection message text: %n%.*s",
7186 &nowlen, msglen, msg);
7187 logevent(buf);
7188 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7189 reason,
7190 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7191 ssh2_disconnect_reasons[reason] : "unknown",
7192 buf+nowlen));
7193 sfree(buf);
7194}
7195
7196void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7197{
7198 /* log the debug message */
7199 char *buf, *msg;
7200 int msglen;
7201 int always_display;
7202
7203 /* XXX maybe we should actually take notice of this */
7204 always_display = ssh2_pkt_getbool(pktin);
7205 ssh_pkt_getstring(pktin, &msg, &msglen);
7206
7207 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7208 logevent(buf);
7209 sfree(buf);
7210}
7211
7212void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7213{
7214 struct Packet *pktout;
7215 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7216 ssh2_pkt_adduint32(pktout, pktin->sequence);
7217 /*
7218 * UNIMPLEMENTED messages MUST appear in the same order as the
7219 * messages they respond to. Hence, never queue them.
7220 */
7221 ssh2_pkt_send_noqueue(ssh, pktout);
7222}
7223
7224/*
7cca0d81 7225 * Handle the top-level SSH2 protocol.
7226 */
b09eaa88 7227static void ssh2_protocol_setup(Ssh ssh)
7228{
7229 int i;
7230
7231 /*
7232 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7233 */
7234 for (i = 0; i < 256; i++)
7235 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7236
7237 /*
7238 * Any message we actually understand, we set to NULL so that
7239 * the coroutines will get it.
7240 */
7241 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7242 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7243 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7244 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7245 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7246 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7247 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7248 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7249 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7250 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7251 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7252 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7253 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7254 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7255 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7256 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7257 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7258 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7259 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7260 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7261 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7262 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7263 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7264 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7265 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7266 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7267 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7268 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7269 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7270 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7271 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7272 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7273 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7274
7275 /*
7276 * These special message types we install handlers for.
7277 */
7278 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7279 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7280 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7281}
7282
9442dd57 7283static void ssh2_timer(void *ctx, long now)
7284{
7285 Ssh ssh = (Ssh)ctx;
7286
e6c1536e 7287 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 7288 now - ssh->next_rekey >= 0) {
7289 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7290 -1, NULL);
7291 }
7292}
7293
ff3187f6 7294static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7295 struct Packet *pktin)
7cca0d81 7296{
b09eaa88 7297 if (ssh->state == SSH_STATE_CLOSED)
7298 return;
7299
9442dd57 7300 if (pktin) {
7301 ssh->incoming_data_size += pktin->encrypted_len;
7302 if (!ssh->kex_in_progress &&
d57f70af 7303 ssh->max_data_size != 0 &&
7304 ssh->incoming_data_size > ssh->max_data_size)
9442dd57 7305 do_ssh2_transport(ssh, "Initiating key re-exchange "
7306 "(too much data received)", -1, NULL);
7307 }
7308
b09eaa88 7309 if (pktin && ssh->packet_dispatch[pktin->type]) {
7310 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7311 return;
b09eaa88 7312 }
7313
7314 if (!ssh->protocol_initial_phase_done ||
7315 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7316 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7317 !ssh->protocol_initial_phase_done) {
7318 ssh->protocol_initial_phase_done = TRUE;
7319 /*
7320 * Allow authconn to initialise itself.
7321 */
7322 do_ssh2_authconn(ssh, NULL, 0, NULL);
7323 }
7324 } else {
7325 do_ssh2_authconn(ssh, in, inlen, pktin);
7326 }
7cca0d81 7327}
7328
7329/*
8df7a775 7330 * Called to set up the connection.
374330e2 7331 *
7332 * Returns an error message, or NULL on success.
374330e2 7333 */
cbe2d68f 7334static const char *ssh_init(void *frontend_handle, void **backend_handle,
7335 Config *cfg,
79bf227b 7336 char *host, int port, char **realhost, int nodelay,
7337 int keepalive)
32874aea 7338{
cbe2d68f 7339 const char *p;
51470298 7340 Ssh ssh;
7341
3d88e64d 7342 ssh = snew(struct ssh_tag);
86916870 7343 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7344 ssh->version = 0; /* when not ready yet */
51470298 7345 ssh->s = NULL;
7346 ssh->cipher = NULL;
371e569c 7347 ssh->v1_cipher_ctx = NULL;
0183b242 7348 ssh->crcda_ctx = NULL;
51470298 7349 ssh->cscipher = NULL;
371e569c 7350 ssh->cs_cipher_ctx = NULL;
51470298 7351 ssh->sccipher = NULL;
371e569c 7352 ssh->sc_cipher_ctx = NULL;
51470298 7353 ssh->csmac = NULL;
a8327734 7354 ssh->cs_mac_ctx = NULL;
51470298 7355 ssh->scmac = NULL;
e0e1a00d 7356 ssh->sc_mac_ctx = NULL;
51470298 7357 ssh->cscomp = NULL;
5366aed8 7358 ssh->cs_comp_ctx = NULL;
51470298 7359 ssh->sccomp = NULL;
5366aed8 7360 ssh->sc_comp_ctx = NULL;
51470298 7361 ssh->kex = NULL;
389aa499 7362 ssh->kex_ctx = NULL;
51470298 7363 ssh->hostkey = NULL;
7364 ssh->exitcode = -1;
7365 ssh->state = SSH_STATE_PREPACKET;
7366 ssh->size_needed = FALSE;
7367 ssh->eof_needed = FALSE;
b9d7bcad 7368 ssh->ldisc = NULL;
a8327734 7369 ssh->logctx = NULL;
51470298 7370 ssh->deferred_send_data = NULL;
7371 ssh->deferred_len = 0;
7372 ssh->deferred_size = 0;
7373 ssh->fallback_cmd = 0;
7374 ssh->pkt_ctx = 0;
302121de 7375 ssh->x11auth = NULL;
be738459 7376 ssh->v1_compressing = FALSE;
51470298 7377 ssh->v2_outgoing_sequence = 0;
7378 ssh->ssh1_rdpkt_crstate = 0;
7379 ssh->ssh2_rdpkt_crstate = 0;
7380 ssh->do_ssh_init_crstate = 0;
7381 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7382 ssh->do_ssh1_connection_crstate = 0;
51470298 7383 ssh->do_ssh1_login_crstate = 0;
7384 ssh->do_ssh2_transport_crstate = 0;
7385 ssh->do_ssh2_authconn_crstate = 0;
7386 ssh->do_ssh_init_state = NULL;
7387 ssh->do_ssh1_login_state = NULL;
7388 ssh->do_ssh2_transport_state = NULL;
7389 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7390 ssh->mainchan = NULL;
968d2d92 7391 ssh->throttled_all = 0;
7392 ssh->v1_stdout_throttling = 0;
590f6a5f 7393 ssh->queue = NULL;
7394 ssh->queuelen = ssh->queuesize = 0;
7395 ssh->queueing = FALSE;
06fadff5 7396 ssh->qhead = ssh->qtail = NULL;
e13bba36 7397 ssh->deferred_rekey_reason = NULL;
51470298 7398
7399 *backend_handle = ssh;
32874aea 7400
8f203108 7401#ifdef MSCRYPTOAPI
32874aea 7402 if (crypto_startup() == 0)
8f203108 7403 return "Microsoft high encryption pack not installed!";
7404#endif
374330e2 7405
51470298 7406 ssh->frontend = frontend_handle;
86916870 7407 ssh->term_width = ssh->cfg.width;
7408 ssh->term_height = ssh->cfg.height;
887035a5 7409
fabd1805 7410 ssh->channels = NULL;
7411 ssh->rportfwds = NULL;
f47a5ffb 7412 ssh->portfwds = NULL;
fabd1805 7413
51470298 7414 ssh->send_ok = 0;
7415 ssh->editing = 0;
7416 ssh->echoing = 0;
7417 ssh->v1_throttle_count = 0;
7418 ssh->overall_bufsize = 0;
7419 ssh->fallback_cmd = 0;
8df7a775 7420
3648d4c5 7421 ssh->protocol = NULL;
7422
b09eaa88 7423 ssh->protocol_initial_phase_done = FALSE;
7424
39934deb 7425 ssh->pinger = NULL;
7426
9442dd57 7427 ssh->incoming_data_size = ssh->outgoing_data_size =
7428 ssh->deferred_data_size = 0L;
d57f70af 7429 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 7430 ssh->kex_in_progress = FALSE;
7431
79bf227b 7432 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7433 if (p != NULL)
7434 return p;
374330e2 7435
5d17ccfc 7436 random_ref();
7437
374330e2 7438 return NULL;
7439}
7440
fabd1805 7441static void ssh_free(void *handle)
7442{
7443 Ssh ssh = (Ssh) handle;
7444 struct ssh_channel *c;
7445 struct ssh_rportfwd *pf;
7446
7447 if (ssh->v1_cipher_ctx)
7448 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7449 if (ssh->cs_cipher_ctx)
7450 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7451 if (ssh->sc_cipher_ctx)
7452 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7453 if (ssh->cs_mac_ctx)
7454 ssh->csmac->free_context(ssh->cs_mac_ctx);
7455 if (ssh->sc_mac_ctx)
7456 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7457 if (ssh->cs_comp_ctx) {
7458 if (ssh->cscomp)
7459 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7460 else
7461 zlib_compress_cleanup(ssh->cs_comp_ctx);
7462 }
7463 if (ssh->sc_comp_ctx) {
7464 if (ssh->sccomp)
7465 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7466 else
7467 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7468 }
fabd1805 7469 if (ssh->kex_ctx)
7470 dh_cleanup(ssh->kex_ctx);
7471 sfree(ssh->savedhost);
7472
590f6a5f 7473 while (ssh->queuelen-- > 0)
7474 ssh_free_packet(ssh->queue[ssh->queuelen]);
7475 sfree(ssh->queue);
7476
06fadff5 7477 while (ssh->qhead) {
7478 struct queued_handler *qh = ssh->qhead;
7479 ssh->qhead = qh->next;
7480 sfree(ssh->qhead);
7481 }
7482 ssh->qhead = ssh->qtail = NULL;
7483
fabd1805 7484 if (ssh->channels) {
7485 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7486 switch (c->type) {
7487 case CHAN_X11:
7488 if (c->u.x11.s != NULL)
7489 x11_close(c->u.x11.s);
7490 break;
7491 case CHAN_SOCKDATA:
7492 if (c->u.pfd.s != NULL)
7493 pfd_close(c->u.pfd.s);
7494 break;
7495 }
7496 sfree(c);
7497 }
7498 freetree234(ssh->channels);
cdb52705 7499 ssh->channels = NULL;
fabd1805 7500 }
7501
7502 if (ssh->rportfwds) {
7503 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7504 sfree(pf);
7505 freetree234(ssh->rportfwds);
cdb52705 7506 ssh->rportfwds = NULL;
fabd1805 7507 }
7508 sfree(ssh->deferred_send_data);
7509 if (ssh->x11auth)
7510 x11_free_auth(ssh->x11auth);
7511 sfree(ssh->do_ssh_init_state);
7512 sfree(ssh->do_ssh1_login_state);
7513 sfree(ssh->do_ssh2_transport_state);
7514 sfree(ssh->do_ssh2_authconn_state);
679539d7 7515 if (ssh->crcda_ctx) {
7516 crcda_free_context(ssh->crcda_ctx);
7517 ssh->crcda_ctx = NULL;
7518 }
fabd1805 7519 if (ssh->s)
36f94d1f 7520 ssh_do_close(ssh);
9442dd57 7521 expire_timer_context(ssh);
39934deb 7522 if (ssh->pinger)
7523 pinger_free(ssh->pinger);
ee50e8b6 7524 sfree(ssh);
5d17ccfc 7525
7526 random_unref();
fabd1805 7527}
7528
374330e2 7529/*
86916870 7530 * Reconfigure the SSH backend.
86916870 7531 */
7532static void ssh_reconfig(void *handle, Config *cfg)
7533{
7534 Ssh ssh = (Ssh) handle;
e13bba36 7535 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 7536 unsigned long old_max_data_size;
7537
39934deb 7538 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
fda2feb1 7539 ssh_setup_portfwd(ssh, cfg);
e6c1536e 7540
7541 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7542 cfg->ssh_rekey_time != 0) {
7543 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7544 long now = GETTICKCOUNT();
7545
7546 if (new_next - now < 0) {
7547 rekeying = "Initiating key re-exchange (timeout shortened)";
7548 } else {
7549 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7550 }
7551 }
7552
7553 old_max_data_size = ssh->max_data_size;
7554 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7555 if (old_max_data_size != ssh->max_data_size &&
7556 ssh->max_data_size != 0) {
7557 if (ssh->outgoing_data_size > ssh->max_data_size ||
7558 ssh->incoming_data_size > ssh->max_data_size)
7559 rekeying = "Initiating key re-exchange (data limit lowered)";
7560 }
7561
e13bba36 7562 if (ssh->cfg.compression != cfg->compression) {
7563 rekeying = "Initiating key re-exchange (compression setting changed)";
7564 rekey_mandatory = TRUE;
7565 }
7566
7567 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7568 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7569 sizeof(ssh->cfg.ssh_cipherlist))) {
7570 rekeying = "Initiating key re-exchange (cipher settings changed)";
7571 rekey_mandatory = TRUE;
e6c1536e 7572 }
7573
86916870 7574 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 7575
7576 if (rekeying) {
7577 if (!ssh->kex_in_progress) {
7578 do_ssh2_transport(ssh, rekeying, -1, NULL);
7579 } else if (rekey_mandatory) {
7580 ssh->deferred_rekey_reason = rekeying;
7581 }
7582 }
86916870 7583}
7584
7585/*
374330e2 7586 * Called to send data down the Telnet connection.
7587 */
51470298 7588static int ssh_send(void *handle, char *buf, int len)
32874aea 7589{
51470298 7590 Ssh ssh = (Ssh) handle;
7591
7592 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7593 return 0;
374330e2 7594
d8baa528 7595 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7596
51470298 7597 return ssh_sendbuffer(ssh);
5471d09a 7598}
7599
7600/*
7601 * Called to query the current amount of buffered stdin data.
7602 */
51470298 7603static int ssh_sendbuffer(void *handle)
5471d09a 7604{
51470298 7605 Ssh ssh = (Ssh) handle;
5471d09a 7606 int override_value;
7607
51470298 7608 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7609 return 0;
7610
7611 /*
7612 * If the SSH socket itself has backed up, add the total backup
7613 * size on that to any individual buffer on the stdin channel.
7614 */
7615 override_value = 0;
51470298 7616 if (ssh->throttled_all)
7617 override_value = ssh->overall_bufsize;
5471d09a 7618
51470298 7619 if (ssh->version == 1) {
5471d09a 7620 return override_value;
51470298 7621 } else if (ssh->version == 2) {
7622 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7623 return override_value;
7624 else
51470298 7625 return (override_value +
7626 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7627 }
7628
7629 return 0;
374330e2 7630}
7631
7632/*
6e48c3fe 7633 * Called to set the size of the window from SSH's POV.
374330e2 7634 */
51470298 7635static void ssh_size(void *handle, int width, int height)
32874aea 7636{
51470298 7637 Ssh ssh = (Ssh) handle;
ff3187f6 7638 struct Packet *pktout;
51470298 7639
7640 ssh->term_width = width;
7641 ssh->term_height = height;
f278d6f8 7642
51470298 7643 switch (ssh->state) {
374330e2 7644 case SSH_STATE_BEFORE_SIZE:
3687d221 7645 case SSH_STATE_PREPACKET:
21248260 7646 case SSH_STATE_CLOSED:
374330e2 7647 break; /* do nothing */
7648 case SSH_STATE_INTERMED:
51470298 7649 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7650 break;
7651 case SSH_STATE_SESSION:
86916870 7652 if (!ssh->cfg.nopty) {
51470298 7653 if (ssh->version == 1) {
7654 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7655 PKT_INT, ssh->term_height,
7656 PKT_INT, ssh->term_width,
32874aea 7657 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7658 } else if (ssh->mainchan) {
ff3187f6 7659 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7660 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7661 ssh2_pkt_addstring(pktout, "window-change");
7662 ssh2_pkt_addbool(pktout, 0);
7663 ssh2_pkt_adduint32(pktout, ssh->term_width);
7664 ssh2_pkt_adduint32(pktout, ssh->term_height);
7665 ssh2_pkt_adduint32(pktout, 0);
7666 ssh2_pkt_adduint32(pktout, 0);
7667 ssh2_pkt_send(ssh, pktout);
32874aea 7668 }
7669 }
7670 break;
374330e2 7671 }
7672}
7673
7674/*
125105d1 7675 * Return a list of the special codes that make sense in this
7676 * protocol.
7677 */
7678static const struct telnet_special *ssh_get_specials(void *handle)
7679{
786ba75e 7680 static const struct telnet_special ssh1_ignore_special[] = {
7681 {"IGNORE message", TS_NOP}
7682 };
7683 static const struct telnet_special ssh2_transport_specials[] = {
62638676 7684 {"IGNORE message", TS_NOP},
9442dd57 7685 {"Repeat key exchange", TS_REKEY},
62638676 7686 };
7687 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7688 {NULL, TS_SEP},
7689 {"Break", TS_BRK},
786ba75e 7690 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 7691 * They include all the ISO C signals, but are a subset of the POSIX
7692 * required signals. */
7693 {"SIGINT (Interrupt)", TS_SIGINT},
7694 {"SIGTERM (Terminate)", TS_SIGTERM},
7695 {"SIGKILL (Kill)", TS_SIGKILL},
7696 {"SIGQUIT (Quit)", TS_SIGQUIT},
7697 {"SIGHUP (Hangup)", TS_SIGHUP},
7698 {"More signals", TS_SUBMENU},
7699 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7700 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7701 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7702 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7703 {NULL, TS_EXITMENU}
62638676 7704 };
7705 static const struct telnet_special specials_end[] = {
6f2d0cde 7706 {NULL, TS_EXITMENU}
62638676 7707 };
786ba75e 7708 /* XXX review this length for any changes: */
7709 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 7710 lenof(ssh2_session_specials) +
7711 lenof(specials_end)];
125105d1 7712 Ssh ssh = (Ssh) handle;
62638676 7713 int i = 0;
7714#define ADD_SPECIALS(name) \
7715 do { \
7716 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7717 memcpy(&ssh_specials[i], name, sizeof name); \
7718 i += lenof(name); \
7719 } while(0)
125105d1 7720
7721 if (ssh->version == 1) {
62638676 7722 /* Don't bother offering IGNORE if we've decided the remote
7723 * won't cope with it, since we wouldn't bother sending it if
7724 * asked anyway. */
7725 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 7726 ADD_SPECIALS(ssh1_ignore_special);
125105d1 7727 } else if (ssh->version == 2) {
786ba75e 7728 ADD_SPECIALS(ssh2_transport_specials);
62638676 7729 if (ssh->mainchan)
7730 ADD_SPECIALS(ssh2_session_specials);
7731 } /* else we're not ready yet */
7732
7733 if (i) {
7734 ADD_SPECIALS(specials_end);
7735 return ssh_specials;
7736 } else {
125105d1 7737 return NULL;
62638676 7738 }
7739#undef ADD_SPECIALS
125105d1 7740}
7741
7742/*
6abbf9e3 7743 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7744 * can send an EOF and collect resulting output (e.g. `plink
7745 * hostname sort').
374330e2 7746 */
51470298 7747static void ssh_special(void *handle, Telnet_Special code)
32874aea 7748{
51470298 7749 Ssh ssh = (Ssh) handle;
ff3187f6 7750 struct Packet *pktout;
51470298 7751
6abbf9e3 7752 if (code == TS_EOF) {
51470298 7753 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7754 /*
7755 * Buffer the EOF in case we are pre-SESSION, so we can
7756 * send it as soon as we reach SESSION.
7757 */
7758 if (code == TS_EOF)
51470298 7759 ssh->eof_needed = TRUE;
32874aea 7760 return;
7761 }
51470298 7762 if (ssh->version == 1) {
7763 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7764 } else if (ssh->mainchan) {
ff3187f6 7765 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7766 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7767 ssh2_pkt_send(ssh, pktout);
32874aea 7768 }
7769 logevent("Sent EOF message");
125105d1 7770 } else if (code == TS_PING || code == TS_NOP) {
51470298 7771 if (ssh->state == SSH_STATE_CLOSED
7772 || ssh->state == SSH_STATE_PREPACKET) return;
7773 if (ssh->version == 1) {
7774 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7775 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7776 } else {
ff3187f6 7777 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7778 ssh2_pkt_addstring_start(pktout);
590f6a5f 7779 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7780 }
9442dd57 7781 } else if (code == TS_REKEY) {
7782 if (!ssh->kex_in_progress && ssh->version == 2) {
7783 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7784 " user request", -1, NULL);
7785 }
125105d1 7786 } else if (code == TS_BRK) {
7787 if (ssh->state == SSH_STATE_CLOSED
7788 || ssh->state == SSH_STATE_PREPACKET) return;
7789 if (ssh->version == 1) {
7790 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7791 } else if (ssh->mainchan) {
ff3187f6 7792 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7793 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7794 ssh2_pkt_addstring(pktout, "break");
7795 ssh2_pkt_addbool(pktout, 0);
7796 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7797 ssh2_pkt_send(ssh, pktout);
125105d1 7798 }
6abbf9e3 7799 } else {
6f2d0cde 7800 /* Is is a POSIX signal? */
7801 char *signame = NULL;
7802 if (code == TS_SIGABRT) signame = "ABRT";
7803 if (code == TS_SIGALRM) signame = "ALRM";
7804 if (code == TS_SIGFPE) signame = "FPE";
7805 if (code == TS_SIGHUP) signame = "HUP";
7806 if (code == TS_SIGILL) signame = "ILL";
7807 if (code == TS_SIGINT) signame = "INT";
7808 if (code == TS_SIGKILL) signame = "KILL";
7809 if (code == TS_SIGPIPE) signame = "PIPE";
7810 if (code == TS_SIGQUIT) signame = "QUIT";
7811 if (code == TS_SIGSEGV) signame = "SEGV";
7812 if (code == TS_SIGTERM) signame = "TERM";
7813 if (code == TS_SIGUSR1) signame = "USR1";
7814 if (code == TS_SIGUSR2) signame = "USR2";
7815 /* The SSH-2 protocol does in principle support arbitrary named
7816 * signals, including signame@domain, but we don't support those. */
7817 if (signame) {
7818 /* It's a signal. */
7819 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7820 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7821 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7822 ssh2_pkt_addstring(pktout, "signal");
7823 ssh2_pkt_addbool(pktout, 0);
7824 ssh2_pkt_addstring(pktout, signame);
7825 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7826 logeventf(ssh, "Sent signal SIG%s", signame);
7827 }
7828 } else {
7829 /* Never heard of it. Do nothing */
7830 }
6abbf9e3 7831 }
374330e2 7832}
7833
51470298 7834void *new_sock_channel(void *handle, Socket s)
d74d141c 7835{
51470298 7836 Ssh ssh = (Ssh) handle;
d74d141c 7837 struct ssh_channel *c;
3d88e64d 7838 c = snew(struct ssh_channel);
51470298 7839 c->ssh = ssh;
d74d141c 7840
7841 if (c) {
bc240b21 7842 c->remoteid = -1; /* to be set when open confirmed */
51470298 7843 c->localid = alloc_channel_id(ssh);
d74d141c 7844 c->closes = 0;
bc240b21 7845 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7846 c->u.pfd.s = s;
013dd8c0 7847 bufchain_init(&c->v.v2.outbuffer);
51470298 7848 add234(ssh->channels, c);
d74d141c 7849 }
7850 return c;
7851}
7852
5471d09a 7853/*
7854 * This is called when stdout/stderr (the entity to which
7855 * from_backend sends data) manages to clear some backlog.
7856 */
ae9ae89f 7857static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7858{
51470298 7859 Ssh ssh = (Ssh) handle;
7860 if (ssh->version == 1) {
7861 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7862 ssh->v1_stdout_throttling = 0;
7863 ssh1_throttle(ssh, -1);
5471d09a 7864 }
7865 } else {
51470298 7866 if (ssh->mainchan && ssh->mainchan->closes == 0)
7867 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7868 }
7869}
7870
6b78788a 7871void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7872{
7873 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7874 Ssh ssh = c->ssh;
ff3187f6 7875 struct Packet *pktout;
d74d141c 7876
57356d63 7877 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7878
51470298 7879 if (ssh->version == 1) {
7880 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7881 PKT_INT, c->localid,
7882 PKT_STR, hostname,
7883 PKT_INT, port,
31fb1866 7884 /* PKT_STR, <org:orgport>, */
bc240b21 7885 PKT_END);
7886 } else {
ff3187f6 7887 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7888 ssh2_pkt_addstring(pktout, "direct-tcpip");
7889 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7890 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7891 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7892 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7893 ssh2_pkt_addstring(pktout, hostname);
7894 ssh2_pkt_adduint32(pktout, port);
bc240b21 7895 /*
7896 * We make up values for the originator data; partly it's
7897 * too much hassle to keep track, and partly I'm not
7898 * convinced the server should be told details like that
7899 * about my local network configuration.
7900 */
ff3187f6 7901 ssh2_pkt_addstring(pktout, "client-side-connection");
7902 ssh2_pkt_adduint32(pktout, 0);
7903 ssh2_pkt_send(ssh, pktout);
bc240b21 7904 }
d74d141c 7905}
7906
51470298 7907static Socket ssh_socket(void *handle)
32874aea 7908{
51470298 7909 Ssh ssh = (Ssh) handle;
7910 return ssh->s;
32874aea 7911}
8ccc75b0 7912
51470298 7913static int ssh_sendok(void *handle)
32874aea 7914{
51470298 7915 Ssh ssh = (Ssh) handle;
7916 return ssh->send_ok;
32874aea 7917}
fb09bf1c 7918
51470298 7919static int ssh_ldisc(void *handle, int option)
32874aea 7920{
51470298 7921 Ssh ssh = (Ssh) handle;
32874aea 7922 if (option == LD_ECHO)
51470298 7923 return ssh->echoing;
32874aea 7924 if (option == LD_EDIT)
51470298 7925 return ssh->editing;
0965bee0 7926 return FALSE;
7927}
7928
b9d7bcad 7929static void ssh_provide_ldisc(void *handle, void *ldisc)
7930{
7931 Ssh ssh = (Ssh) handle;
7932 ssh->ldisc = ldisc;
7933}
7934
a8327734 7935static void ssh_provide_logctx(void *handle, void *logctx)
7936{
7937 Ssh ssh = (Ssh) handle;
7938 ssh->logctx = logctx;
7939}
7940
51470298 7941static int ssh_return_exitcode(void *handle)
7942{
7943 Ssh ssh = (Ssh) handle;
3bb2f322 7944 if (ssh->s != NULL)
7945 return -1;
7946 else
7947 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7948}
7949
7950/*
f89c3294 7951 * cfg_info for SSH is the currently running version of the
7952 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
7953 */
7954static int ssh_cfg_info(void *handle)
7955{
7956 Ssh ssh = (Ssh) handle;
7957 return ssh->version;
7958}
7959
7960/*
51470298 7961 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7962 * that fails. This variable is the means by which scp.c can reach
7963 * into the SSH code and find out which one it got.
7964 */
7965extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7966{
51470298 7967 Ssh ssh = (Ssh) handle;
7968 return ssh->fallback_cmd;
d8d6c7e5 7969}
7970
374330e2 7971Backend ssh_backend = {
7972 ssh_init,
fabd1805 7973 ssh_free,
86916870 7974 ssh_reconfig,
374330e2 7975 ssh_send,
5471d09a 7976 ssh_sendbuffer,
374330e2 7977 ssh_size,
4017be6d 7978 ssh_special,
125105d1 7979 ssh_get_specials,
8ccc75b0 7980 ssh_socket,
d8d6c7e5 7981 ssh_return_exitcode,
97db3be4 7982 ssh_sendok,
0965bee0 7983 ssh_ldisc,
b9d7bcad 7984 ssh_provide_ldisc,
a8327734 7985 ssh_provide_logctx,
5471d09a 7986 ssh_unthrottle,
f89c3294 7987 ssh_cfg_info,
97db3be4 7988 22
bc240b21 7989};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator