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[u/mdw/putty] / ssh.c
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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
109#define SSH2_PKTCTX_PUBLICKEY 0x0010
110#define SSH2_PKTCTX_PASSWORD 0x0020
111#define SSH2_PKTCTX_KBDINTER 0x0040
112#define SSH2_PKTCTX_AUTH_MASK 0x00F0
113
32874aea 114#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 129
130static const char *const ssh2_disconnect_reasons[] = {
131 NULL,
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
147};
9005f3ba 148
32874aea 149#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 153
32874aea 154#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 155
7d503c31 156/*
157 * Various remote-bug flags.
158 */
159#define BUG_CHOKES_ON_SSH1_IGNORE 1
160#define BUG_SSH2_HMAC 2
bd358db1 161#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 162#define BUG_CHOKES_ON_RSA 8
1dd353b5 163#define BUG_SSH2_RSA_PADDING 16
088bde77 164#define BUG_SSH2_DERIVEKEY 32
83e7d008 165/* 64 was BUG_SSH2_DH_GEX, now spare */
dda87a28 166#define BUG_SSH2_PK_SESSIONID 128
bd358db1 167
00db133f 168#define translate(x) if (type == x) return #x
51470298 169#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
ae9ae89f 170static char *ssh1_pkt_type(int type)
00db133f 171{
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
213 return "unknown";
214}
ae9ae89f 215static char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 216{
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
d1aaf71d 225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
00db133f 227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
253 return "unknown";
254}
255#undef translate
256#undef translatec
7d503c31 257
fb09bf1c 258#define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
263
264#define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
269
9a10ecf4 270/* Enumeration values for fields in SSH-1 packets */
271enum {
272 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
273 /* These values are for communicating relevant semantics of
274 * fields to the packet logging code. */
275 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
276};
972a41c8 277
acddebd9 278/*
279 * Coroutine mechanics for the sillier bits of the code. If these
280 * macros look impenetrable to you, you might find it helpful to
281 * read
282 *
283 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
284 *
285 * which explains the theory behind these macros.
b624d1e6 286 *
287 * In particular, if you are getting `case expression not constant'
288 * errors when building with MS Visual Studio, this is because MS's
289 * Edit and Continue debugging feature causes their compiler to
290 * violate ANSI C. To disable Edit and Continue debugging:
291 *
292 * - right-click ssh.c in the FileView
293 * - click Settings
294 * - select the C/C++ tab and the General category
295 * - under `Debug info:', select anything _other_ than `Program
296 * Database for Edit and Continue'.
acddebd9 297 */
51470298 298#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
299#define crState(t) \
300 struct t *s; \
3d88e64d 301 if (!ssh->t) ssh->t = snew(struct t); \
51470298 302 s = ssh->t;
303#define crFinish(z) } *crLine = 0; return (z); }
304#define crFinishV } *crLine = 0; return; }
374330e2 305#define crReturn(z) \
306 do {\
51470298 307 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 308 } while (0)
309#define crReturnV \
310 do {\
51470298 311 *crLine=__LINE__; return; case __LINE__:;\
374330e2 312 } while (0)
51470298 313#define crStop(z) do{ *crLine = 0; return (z); }while(0)
314#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 315#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 316#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 317
51470298 318typedef struct ssh_tag *Ssh;
ff3187f6 319struct Packet;
320
321static struct Packet *ssh2_pkt_init(int pkt_type);
322static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
323static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
324static void ssh2_pkt_addstring_start(struct Packet *);
325static void ssh2_pkt_addstring_str(struct Packet *, char *data);
326static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
327static void ssh2_pkt_addstring(struct Packet *, char *data);
d8baa528 328static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
ff3187f6 329static void ssh2_pkt_addmp(struct Packet *, Bignum b);
330static int ssh2_pkt_construct(Ssh, struct Packet *);
331static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 332static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 333static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
334 struct Packet *pktin);
335static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
336 struct Packet *pktin);
3d63ca2e 337
5471d09a 338/*
339 * Buffer management constants. There are several of these for
340 * various different purposes:
341 *
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
346 * happen very often.
347 *
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
354 *
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
356 * channels.
357 */
358
359#define SSH1_BUFFER_LIMIT 32768
360#define SSH_MAX_BACKLOG 32768
361#define OUR_V2_WINSIZE 16384
d74d141c 362
85cc02bb 363const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 364
e0e1a00d 365static void *nullmac_make_context(void)
366{
367 return NULL;
368}
369static void nullmac_free_context(void *handle)
370{
371}
372static void nullmac_key(void *handle, unsigned char *key)
32874aea 373{
374}
e0e1a00d 375static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 376 unsigned long seq)
377{
378}
e0e1a00d 379static int nullmac_verify(void *handle, unsigned char *blk, int len,
380 unsigned long seq)
32874aea 381{
382 return 1;
383}
57476f6b 384const static struct ssh_mac ssh_mac_none = {
e0e1a00d 385 nullmac_make_context, nullmac_free_context, nullmac_key,
386 nullmac_generate, nullmac_verify, "none", 0
e5574168 387};
8b2715b2 388const static struct ssh_mac *macs[] = {
32874aea 389 &ssh_sha1, &ssh_md5, &ssh_mac_none
390};
8b2715b2 391const static struct ssh_mac *buggymacs[] = {
32874aea 392 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
393};
e5574168 394
5366aed8 395static void *ssh_comp_none_init(void)
396{
397 return NULL;
398}
399static void ssh_comp_none_cleanup(void *handle)
32874aea 400{
401}
5366aed8 402static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 403 unsigned char **outblock, int *outlen)
404{
405 return 0;
406}
5366aed8 407static int ssh_comp_none_disable(void *handle)
32874aea 408{
4ba9b64b 409 return 0;
410}
57476f6b 411const static struct ssh_compress ssh_comp_none = {
4ba9b64b 412 "none",
5366aed8 413 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_disable, NULL
e5574168 416};
4ba9b64b 417extern const struct ssh_compress ssh_zlib;
418const static struct ssh_compress *compressions[] = {
32874aea 419 &ssh_zlib, &ssh_comp_none
420};
374330e2 421
32874aea 422enum { /* channel types */
783415f8 423 CHAN_MAINSESSION,
424 CHAN_X11,
425 CHAN_AGENT,
bc240b21 426 CHAN_SOCKDATA,
427 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 428};
429
dacbd0e8 430/*
431 * 2-3-4 tree storing channels.
432 */
433struct ssh_channel {
51470298 434 Ssh ssh; /* pointer back to main context */
d211621f 435 unsigned remoteid, localid;
dacbd0e8 436 int type;
0357890f 437 /*
438 * In SSH1, this value contains four bits:
439 *
440 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
441 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
442 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
443 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
444 *
445 * A channel is completely finished with when all four bits are set.
446 */
dacbd0e8 447 int closes;
5471d09a 448 union {
449 struct ssh1_data_channel {
450 int throttling;
451 } v1;
452 struct ssh2_data_channel {
453 bufchain outbuffer;
454 unsigned remwindow, remmaxpkt;
455 unsigned locwindow;
456 } v2;
457 } v;
dacbd0e8 458 union {
32874aea 459 struct ssh_agent_channel {
460 unsigned char *message;
461 unsigned char msglen[4];
a03c9f9c 462 unsigned lensofar, totallen;
32874aea 463 } a;
464 struct ssh_x11_channel {
465 Socket s;
466 } x11;
d74d141c 467 struct ssh_pfd_channel {
468 Socket s;
469 } pfd;
dacbd0e8 470 } u;
471};
57476f6b 472
d74d141c 473/*
bc240b21 474 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
475 * 2 use this structure in different ways, reflecting SSH 2's
476 * altogether saner approach to port forwarding.
477 *
478 * In SSH 1, you arrange a remote forwarding by sending the server
479 * the remote port number, and the local destination host:port.
480 * When a connection comes in, the server sends you back that
481 * host:port pair, and you connect to it. This is a ready-made
482 * security hole if you're not on the ball: a malicious server
483 * could send you back _any_ host:port pair, so if you trustingly
484 * connect to the address it gives you then you've just opened the
485 * entire inside of your corporate network just by connecting
486 * through it to a dodgy SSH server. Hence, we must store a list of
487 * host:port pairs we _are_ trying to forward to, and reject a
488 * connection request from the server if it's not in the list.
489 *
490 * In SSH 2, each side of the connection minds its own business and
491 * doesn't send unnecessary information to the other. You arrange a
492 * remote forwarding by sending the server just the remote port
493 * number. When a connection comes in, the server tells you which
494 * of its ports was connected to; and _you_ have to remember what
495 * local host:port pair went with that port number.
496 *
06fadff5 497 * Hence, in SSH 1 this structure is indexed by destination
498 * host:port pair, whereas in SSH 2 it is indexed by source port.
d74d141c 499 */
fda2feb1 500struct ssh_portfwd; /* forward declaration */
501
d74d141c 502struct ssh_rportfwd {
bc240b21 503 unsigned sport, dport;
504 char dhost[256];
06fadff5 505 char *sportdesc;
fda2feb1 506 struct ssh_portfwd *pfrec;
d74d141c 507};
fda2feb1 508#define free_rportfwd(pf) ( \
509 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
510
511/*
512 * Separately to the rportfwd tree (which is for looking up port
513 * open requests from the server), a tree of _these_ structures is
514 * used to keep track of all the currently open port forwardings,
515 * so that we can reconfigure in mid-session if the user requests
516 * it.
517 */
518struct ssh_portfwd {
84328ddb 519 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 520 int type;
521 unsigned sport, dport;
522 char *saddr, *daddr;
3fe92132 523 char *sserv, *dserv;
fda2feb1 524 struct ssh_rportfwd *remote;
05581745 525 int addressfamily;
fda2feb1 526 void *local;
527};
528#define free_portfwd(pf) ( \
3fe92132 529 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
530 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 531
57476f6b 532struct Packet {
533 long length;
534 int type;
b09eaa88 535 unsigned long sequence;
57476f6b 536 unsigned char *data;
537 unsigned char *body;
538 long savedpos;
539 long maxlen;
9442dd57 540 long encrypted_len; /* for SSH2 total-size counting */
ff3187f6 541
542 /*
543 * State associated with packet logging
544 */
545 int logmode;
546 int nblanks;
547 struct logblank_t *blanks;
57476f6b 548};
549
ff3187f6 550static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
551 struct Packet *pktin);
552static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
553 struct Packet *pktin);
b09eaa88 554static void ssh1_protocol_setup(Ssh ssh);
555static void ssh2_protocol_setup(Ssh ssh);
51470298 556static void ssh_size(void *handle, int width, int height);
557static void ssh_special(void *handle, Telnet_Special);
5471d09a 558static int ssh2_try_send(struct ssh_channel *c);
51470298 559static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
560static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 561static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 562static int ssh_sendbuffer(void *handle);
36f94d1f 563static void ssh_do_close(Ssh ssh);
ff3187f6 564static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
565static int ssh2_pkt_getbool(struct Packet *pkt);
566static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 567static void ssh2_timer(void *ctx, long now);
568static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
569 struct Packet *pktin);
57476f6b 570
51470298 571struct rdpkt1_state_tag {
57476f6b 572 long len, pad, biglen, to_read;
573 unsigned long realcrc, gotcrc;
574 unsigned char *p;
575 int i;
576 int chunk;
ff3187f6 577 struct Packet *pktin;
51470298 578};
57476f6b 579
51470298 580struct rdpkt2_state_tag {
960e736a 581 long len, pad, payload, packetlen, maclen;
582 int i;
583 int cipherblk;
584 unsigned long incoming_sequence;
ff3187f6 585 struct Packet *pktin;
51470298 586};
587
b09eaa88 588typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 589typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
590
591struct queued_handler;
592struct queued_handler {
593 int msg1, msg2;
594 chandler_fn_t handler;
595 void *ctx;
596 struct queued_handler *next;
597};
b09eaa88 598
51470298 599struct ssh_tag {
600 const struct plug_function_table *fn;
601 /* the above field _must_ be first in the structure */
602
603 SHA_State exhash, exhashbase;
604
605 Socket s;
606
b9d7bcad 607 void *ldisc;
a8327734 608 void *logctx;
b9d7bcad 609
51470298 610 unsigned char session_key[32];
611 int v1_compressing;
612 int v1_remote_protoflags;
613 int v1_local_protoflags;
614 int agentfwd_enabled;
615 int X11_fwd_enabled;
616 int remote_bugs;
617 const struct ssh_cipher *cipher;
371e569c 618 void *v1_cipher_ctx;
0183b242 619 void *crcda_ctx;
51470298 620 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 621 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 622 const struct ssh_mac *csmac, *scmac;
e0e1a00d 623 void *cs_mac_ctx, *sc_mac_ctx;
51470298 624 const struct ssh_compress *cscomp, *sccomp;
5366aed8 625 void *cs_comp_ctx, *sc_comp_ctx;
51470298 626 const struct ssh_kex *kex;
627 const struct ssh_signkey *hostkey;
628 unsigned char v2_session_id[20];
27cd7fc2 629 void *kex_ctx;
51470298 630
631 char *savedhost;
632 int savedport;
633 int send_ok;
634 int echoing, editing;
635
636 void *frontend;
637
db219738 638 int ospeed, ispeed; /* temporaries */
51470298 639 int term_width, term_height;
640
641 tree234 *channels; /* indexed by local id */
642 struct ssh_channel *mainchan; /* primary session channel */
643 int exitcode;
644
fda2feb1 645 tree234 *rportfwds, *portfwds;
51470298 646
647 enum {
648 SSH_STATE_PREPACKET,
649 SSH_STATE_BEFORE_SIZE,
650 SSH_STATE_INTERMED,
651 SSH_STATE_SESSION,
652 SSH_STATE_CLOSED
653 } state;
654
655 int size_needed, eof_needed;
656
590f6a5f 657 struct Packet **queue;
658 int queuelen, queuesize;
659 int queueing;
51470298 660 unsigned char *deferred_send_data;
661 int deferred_len, deferred_size;
662
663 /*
664 * Gross hack: pscp will try to start SFTP but fall back to
665 * scp1 if that fails. This variable is the means by which
666 * scp.c can reach into the SSH code and find out which one it
667 * got.
668 */
669 int fallback_cmd;
670
671 /*
672 * Used for username and password input.
673 */
674 char *userpass_input_buffer;
675 int userpass_input_buflen;
676 int userpass_input_bufpos;
677 int userpass_input_echo;
678
51470298 679 int pkt_ctx;
680
302121de 681 void *x11auth;
682
51470298 683 int version;
684 int v1_throttle_count;
685 int overall_bufsize;
686 int throttled_all;
687 int v1_stdout_throttling;
688 int v2_outgoing_sequence;
689
690 int ssh1_rdpkt_crstate;
691 int ssh2_rdpkt_crstate;
692 int do_ssh_init_crstate;
693 int ssh_gotdata_crstate;
51470298 694 int do_ssh1_login_crstate;
b09eaa88 695 int do_ssh1_connection_crstate;
51470298 696 int do_ssh2_transport_crstate;
697 int do_ssh2_authconn_crstate;
698
699 void *do_ssh_init_state;
700 void *do_ssh1_login_state;
701 void *do_ssh2_transport_state;
702 void *do_ssh2_authconn_state;
703
704 struct rdpkt1_state_tag rdpkt1_state;
705 struct rdpkt2_state_tag rdpkt2_state;
706
b09eaa88 707 /* ssh1 and ssh2 use this for different things, but both use it */
708 int protocol_initial_phase_done;
709
ff3187f6 710 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
711 struct Packet *pkt);
712 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 713
714 /*
715 * We maintain a full _copy_ of a Config structure here, not
716 * merely a pointer to it. That way, when we're passed a new
717 * one for reconfiguration, we can check the differences and
718 * potentially reconfigure port forwardings etc in mid-session.
719 */
720 Config cfg;
839f10db 721
722 /*
723 * Used to transfer data back from async agent callbacks.
724 */
725 void *agent_response;
726 int agent_response_len;
b09eaa88 727
728 /*
729 * Dispatch table for packet types that we may have to deal
730 * with at any time.
731 */
732 handler_fn_t packet_dispatch[256];
39934deb 733
734 /*
06fadff5 735 * Queues of one-off handler functions for success/failure
736 * indications from a request.
737 */
738 struct queued_handler *qhead, *qtail;
739
740 /*
39934deb 741 * This module deals with sending keepalives.
742 */
743 Pinger pinger;
9442dd57 744
745 /*
746 * Track incoming and outgoing data sizes and time, for
747 * size-based rekeys.
748 */
749 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 750 unsigned long max_data_size;
9442dd57 751 int kex_in_progress;
e6c1536e 752 long next_rekey, last_rekey;
e13bba36 753 char *deferred_rekey_reason; /* points to STATIC string; don't free */
51470298 754};
960e736a 755
382908ad 756#define logevent(s) logevent(ssh->frontend, s)
a8327734 757
758/* logevent, only printf-formatted. */
cbe2d68f 759static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 760{
761 va_list ap;
57356d63 762 char *buf;
a8327734 763
764 va_start(ap, fmt);
57356d63 765 buf = dupvprintf(fmt, ap);
a8327734 766 va_end(ap);
57356d63 767 logevent(buf);
57356d63 768 sfree(buf);
a8327734 769}
770
6b5cf8b4 771#define bombout(msg) \
772 do { \
773 char *text = dupprintf msg; \
36f94d1f 774 ssh_do_close(ssh); \
6b5cf8b4 775 logevent(text); \
776 connection_fatal(ssh->frontend, "%s", text); \
777 sfree(text); \
778 } while (0)
a8327734 779
9a10ecf4 780/* Functions to leave bits out of the SSH packet log file. */
781
ff3187f6 782static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 783{
784 if (ssh->cfg.logomitpass)
ff3187f6 785 pkt->logmode = blanktype;
9a10ecf4 786}
787
ff3187f6 788static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 789{
790 if (ssh->cfg.logomitdata)
ff3187f6 791 pkt->logmode = blanktype;
9a10ecf4 792}
793
ff3187f6 794static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 795{
ff3187f6 796 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 797}
798
32874aea 799static int ssh_channelcmp(void *av, void *bv)
800{
801 struct ssh_channel *a = (struct ssh_channel *) av;
802 struct ssh_channel *b = (struct ssh_channel *) bv;
803 if (a->localid < b->localid)
804 return -1;
805 if (a->localid > b->localid)
806 return +1;
dacbd0e8 807 return 0;
808}
32874aea 809static int ssh_channelfind(void *av, void *bv)
810{
811 unsigned *a = (unsigned *) av;
812 struct ssh_channel *b = (struct ssh_channel *) bv;
813 if (*a < b->localid)
814 return -1;
815 if (*a > b->localid)
816 return +1;
dacbd0e8 817 return 0;
818}
819
bc240b21 820static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 821{
822 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
823 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
824 int i;
bc240b21 825 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 826 return i < 0 ? -1 : +1;
bc240b21 827 if (a->dport > b->dport)
828 return +1;
829 if (a->dport < b->dport)
830 return -1;
831 return 0;
832}
833
834static int ssh_rportcmp_ssh2(void *av, void *bv)
835{
836 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
837 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 838
bc240b21 839 if (a->sport > b->sport)
d74d141c 840 return +1;
bc240b21 841 if (a->sport < b->sport)
842 return -1;
d74d141c 843 return 0;
844}
845
fda2feb1 846/*
847 * Special form of strcmp which can cope with NULL inputs. NULL is
848 * defined to sort before even the empty string.
849 */
850static int nullstrcmp(const char *a, const char *b)
851{
852 if (a == NULL && b == NULL)
853 return 0;
854 if (a == NULL)
855 return -1;
856 if (b == NULL)
857 return +1;
858 return strcmp(a, b);
859}
860
861static int ssh_portcmp(void *av, void *bv)
862{
863 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
864 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
865 int i;
866 if (a->type > b->type)
867 return +1;
868 if (a->type < b->type)
869 return -1;
84328ddb 870 if (a->addressfamily > b->addressfamily)
871 return +1;
872 if (a->addressfamily < b->addressfamily)
873 return -1;
fda2feb1 874 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
875 return i < 0 ? -1 : +1;
876 if (a->sport > b->sport)
877 return +1;
878 if (a->sport < b->sport)
879 return -1;
880 if (a->type != 'D') {
881 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
882 return i < 0 ? -1 : +1;
883 if (a->dport > b->dport)
884 return +1;
885 if (a->dport < b->dport)
886 return -1;
887 }
888 return 0;
889}
890
51470298 891static int alloc_channel_id(Ssh ssh)
32874aea 892{
260f3dec 893 const unsigned CHANNEL_NUMBER_OFFSET = 256;
894 unsigned low, high, mid;
d2371c81 895 int tsize;
896 struct ssh_channel *c;
897
898 /*
899 * First-fit allocation of channel numbers: always pick the
900 * lowest unused one. To do this, binary-search using the
901 * counted B-tree to find the largest channel ID which is in a
902 * contiguous sequence from the beginning. (Precisely
903 * everything in that sequence must have ID equal to its tree
904 * index plus CHANNEL_NUMBER_OFFSET.)
905 */
51470298 906 tsize = count234(ssh->channels);
d2371c81 907
32874aea 908 low = -1;
909 high = tsize;
d2371c81 910 while (high - low > 1) {
911 mid = (high + low) / 2;
51470298 912 c = index234(ssh->channels, mid);
d2371c81 913 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
914 low = mid; /* this one is fine */
915 else
916 high = mid; /* this one is past it */
917 }
918 /*
919 * Now low points to either -1, or the tree index of the
920 * largest ID in the initial sequence.
921 */
922 {
923 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 924 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 925 }
926 return low + 1 + CHANNEL_NUMBER_OFFSET;
927}
928
9fab77dc 929static void c_write(Ssh ssh, const char *buf, int len)
32874aea 930{
67779be7 931 if ((flags & FLAG_STDERR)) {
32874aea 932 int i;
933 for (i = 0; i < len; i++)
934 if (buf[i] != '\r')
935 fputc(buf[i], stderr);
fb09bf1c 936 return;
937 }
51470298 938 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 939}
940
9fab77dc 941static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 942{
a209e957 943 int i;
944 for (i = 0; i < len; i++) {
32874aea 945 if (buf[i] == '\n')
51470298 946 c_write(ssh, "\r\n", 2);
32874aea 947 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 948 c_write(ssh, buf + i, 1);
a209e957 949 }
950}
951
9fab77dc 952static void c_write_str(Ssh ssh, const char *buf)
32874aea 953{
51470298 954 c_write(ssh, buf, strlen(buf));
1408a877 955}
956
ff3187f6 957static void ssh_free_packet(struct Packet *pkt)
958{
959 sfree(pkt->data);
960 sfree(pkt);
961}
962static struct Packet *ssh_new_packet(void)
963{
964 struct Packet *pkt = snew(struct Packet);
965
966 pkt->data = NULL;
967 pkt->maxlen = 0;
968 pkt->logmode = PKTLOG_EMIT;
969 pkt->nblanks = 0;
970 pkt->blanks = NULL;
971
972 return pkt;
973}
974
fb09bf1c 975/*
976 * Collect incoming data in the incoming packet buffer.
e5574168 977 * Decipher and verify the packet when it is completely read.
978 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 979 * Update the *data and *datalen variables.
ff3187f6 980 * Return a Packet structure when a packet is completed.
fb09bf1c 981 */
ff3187f6 982static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 983{
51470298 984 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 985
51470298 986 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 987
ff3187f6 988 st->pktin = ssh_new_packet();
989
990 st->pktin->type = 0;
991 st->pktin->length = 0;
374330e2 992
57476f6b 993 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 994 while ((*datalen) == 0)
ff3187f6 995 crReturn(NULL);
57476f6b 996 st->len = (st->len << 8) + **data;
fb09bf1c 997 (*data)++, (*datalen)--;
998 }
374330e2 999
57476f6b 1000 st->pad = 8 - (st->len % 8);
1001 st->biglen = st->len + st->pad;
ff3187f6 1002 st->pktin->length = st->len - 5;
fb09bf1c 1003
ae0500e5 1004 if (st->biglen < 0) {
1005 bombout(("Extremely large packet length from server suggests"
1006 " data stream corruption"));
ff3187f6 1007 ssh_free_packet(st->pktin);
1008 crStop(NULL);
ae0500e5 1009 }
1010
ff3187f6 1011 st->pktin->maxlen = st->biglen;
1012 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1013
57476f6b 1014 st->to_read = st->biglen;
ff3187f6 1015 st->p = st->pktin->data;
57476f6b 1016 while (st->to_read > 0) {
32874aea 1017 st->chunk = st->to_read;
fb09bf1c 1018 while ((*datalen) == 0)
ff3187f6 1019 crReturn(NULL);
57476f6b 1020 if (st->chunk > (*datalen))
1021 st->chunk = (*datalen);
1022 memcpy(st->p, *data, st->chunk);
1023 *data += st->chunk;
1024 *datalen -= st->chunk;
1025 st->p += st->chunk;
1026 st->to_read -= st->chunk;
fb09bf1c 1027 }
374330e2 1028
ff3187f6 1029 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1030 st->biglen, NULL)) {
6b5cf8b4 1031 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1032 ssh_free_packet(st->pktin);
1033 crStop(NULL);
9a3a93a5 1034 }
1035
51470298 1036 if (ssh->cipher)
ff3187f6 1037 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1038
ff3187f6 1039 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1040 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1041 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1042 bombout(("Incorrect CRC received on packet"));
ff3187f6 1043 ssh_free_packet(st->pktin);
1044 crStop(NULL);
fb09bf1c 1045 }
572f871e 1046
ff3187f6 1047 st->pktin->body = st->pktin->data + st->pad + 1;
1048 st->pktin->savedpos = 0;
4ba9b64b 1049
51470298 1050 if (ssh->v1_compressing) {
4ba9b64b 1051 unsigned char *decompblk;
1052 int decomplen;
36b8d9bb 1053 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1054 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1055 &decompblk, &decomplen)) {
1056 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1057 ssh_free_packet(st->pktin);
1058 crStop(NULL);
36b8d9bb 1059 }
4ba9b64b 1060
ff3187f6 1061 if (st->pktin->maxlen < st->pad + decomplen) {
1062 st->pktin->maxlen = st->pad + decomplen;
1063 st->pktin->data = sresize(st->pktin->data,
1064 st->pktin->maxlen + APIEXTRA,
3d88e64d 1065 unsigned char);
ff3187f6 1066 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1067 }
1068
ff3187f6 1069 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1070 sfree(decompblk);
ff3187f6 1071 st->pktin->length = decomplen - 1;
4ba9b64b 1072 }
1073
ff3187f6 1074 st->pktin->type = st->pktin->body[-1];
00db133f 1075
9a10ecf4 1076 /*
1077 * Log incoming packet, possibly omitting sensitive fields.
1078 */
1079 if (ssh->logctx) {
1080 int nblanks = 0;
1081 struct logblank_t blank;
1082 if (ssh->cfg.logomitdata) {
1083 int do_blank = FALSE, blank_prefix = 0;
1084 /* "Session data" packets - omit the data field */
ff3187f6 1085 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1086 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1087 do_blank = TRUE; blank_prefix = 0;
ff3187f6 1088 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
9a10ecf4 1089 do_blank = TRUE; blank_prefix = 4;
1090 }
1091 if (do_blank) {
1092 blank.offset = blank_prefix;
ff3187f6 1093 blank.len = st->pktin->length;
9a10ecf4 1094 blank.type = PKTLOG_OMIT;
1095 nblanks = 1;
1096 }
1097 }
a8327734 1098 log_packet(ssh->logctx,
ff3187f6 1099 PKT_INCOMING, st->pktin->type,
1100 ssh1_pkt_type(st->pktin->type),
1101 st->pktin->body, st->pktin->length,
9a10ecf4 1102 nblanks, &blank);
1103 }
00db133f 1104
ff3187f6 1105 crFinish(st->pktin);
fb09bf1c 1106}
1107
ff3187f6 1108static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1109{
51470298 1110 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1111
51470298 1112 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1113
ff3187f6 1114 st->pktin = ssh_new_packet();
1115
1116 st->pktin->type = 0;
1117 st->pktin->length = 0;
51470298 1118 if (ssh->sccipher)
1119 st->cipherblk = ssh->sccipher->blksize;
e5574168 1120 else
32874aea 1121 st->cipherblk = 8;
960e736a 1122 if (st->cipherblk < 8)
32874aea 1123 st->cipherblk = 8;
960e736a 1124
ff3187f6 1125 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1126
1127 /*
1128 * Acquire and decrypt the first block of the packet. This will
1129 * contain the length and padding details.
1130 */
32874aea 1131 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1132 while ((*datalen) == 0)
ff3187f6 1133 crReturn(NULL);
1134 st->pktin->data[st->i] = *(*data)++;
32874aea 1135 (*datalen)--;
e5574168 1136 }
4252c9cc 1137
51470298 1138 if (ssh->sccipher)
371e569c 1139 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1140 st->pktin->data, st->cipherblk);
e5574168 1141
1142 /*
1143 * Now get the length and padding figures.
1144 */
ff3187f6 1145 st->len = GET_32BIT(st->pktin->data);
1146 st->pad = st->pktin->data[4];
e5574168 1147
1148 /*
717dc483 1149 * _Completely_ silly lengths should be stomped on before they
1150 * do us any more damage.
1151 */
1152 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 1153 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1154 ssh_free_packet(st->pktin);
1155 crStop(NULL);
717dc483 1156 }
1157
1158 /*
e5574168 1159 * This enables us to deduce the payload length.
1160 */
960e736a 1161 st->payload = st->len - st->pad - 1;
e5574168 1162
ff3187f6 1163 st->pktin->length = st->payload + 5;
e5574168 1164
1165 /*
1166 * So now we can work out the total packet length.
1167 */
960e736a 1168 st->packetlen = st->len + 4;
51470298 1169 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1170
1171 /*
ff3187f6 1172 * Allocate memory for the rest of the packet.
e5574168 1173 */
ff3187f6 1174 st->pktin->maxlen = st->packetlen + st->maclen;
1175 st->pktin->data = sresize(st->pktin->data,
1176 st->pktin->maxlen + APIEXTRA,
1177 unsigned char);
e5574168 1178
1179 /*
1180 * Read and decrypt the remainder of the packet.
1181 */
32874aea 1182 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1183 st->i++) {
e5574168 1184 while ((*datalen) == 0)
ff3187f6 1185 crReturn(NULL);
1186 st->pktin->data[st->i] = *(*data)++;
32874aea 1187 (*datalen)--;
e5574168 1188 }
1189 /* Decrypt everything _except_ the MAC. */
51470298 1190 if (ssh->sccipher)
371e569c 1191 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1192 st->pktin->data + st->cipherblk,
51470298 1193 st->packetlen - st->cipherblk);
e5574168 1194
9442dd57 1195 st->pktin->encrypted_len = st->packetlen;
1196
e5574168 1197 /*
1198 * Check the MAC.
1199 */
51470298 1200 if (ssh->scmac
ff3187f6 1201 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1202 st->incoming_sequence)) {
6b5cf8b4 1203 bombout(("Incorrect MAC received on packet"));
ff3187f6 1204 ssh_free_packet(st->pktin);
1205 crStop(NULL);
8d5de777 1206 }
b09eaa88 1207
1208 st->pktin->sequence = st->incoming_sequence++;
e5574168 1209
4ba9b64b 1210 /*
1211 * Decompress packet payload.
1212 */
1213 {
1214 unsigned char *newpayload;
1215 int newlen;
51470298 1216 if (ssh->sccomp &&
5366aed8 1217 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1218 st->pktin->data + 5, st->pktin->length - 5,
51470298 1219 &newpayload, &newlen)) {
ff3187f6 1220 if (st->pktin->maxlen < newlen + 5) {
1221 st->pktin->maxlen = newlen + 5;
1222 st->pktin->data = sresize(st->pktin->data,
1223 st->pktin->maxlen + APIEXTRA,
3d88e64d 1224 unsigned char);
4ba9b64b 1225 }
ff3187f6 1226 st->pktin->length = 5 + newlen;
1227 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1228 sfree(newpayload);
4ba9b64b 1229 }
1230 }
1231
ff3187f6 1232 st->pktin->savedpos = 6;
1233 st->pktin->body = st->pktin->data;
1234 st->pktin->type = st->pktin->data[5];
e5574168 1235
9a10ecf4 1236 /*
1237 * Log incoming packet, possibly omitting sensitive fields.
1238 */
1239 if (ssh->logctx) {
1240 int nblanks = 0;
1241 struct logblank_t blank;
1242 if (ssh->cfg.logomitdata) {
1243 int do_blank = FALSE, blank_prefix = 0;
1244 /* "Session data" packets - omit the data field */
ff3187f6 1245 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1246 do_blank = TRUE; blank_prefix = 4;
ff3187f6 1247 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
9a10ecf4 1248 do_blank = TRUE; blank_prefix = 8;
1249 }
1250 if (do_blank) {
1251 blank.offset = blank_prefix;
ff3187f6 1252 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1253 blank.type = PKTLOG_OMIT;
1254 nblanks = 1;
1255 }
1256 }
ff3187f6 1257 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1258 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1259 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1260 nblanks, &blank);
1261 }
00db133f 1262
ff3187f6 1263 crFinish(st->pktin);
e5574168 1264}
1265
ff3187f6 1266static void ssh1_pktout_size(struct Packet *pkt, int len)
32874aea 1267{
374330e2 1268 int pad, biglen;
1269
1270 len += 5; /* type and CRC */
32874aea 1271 pad = 8 - (len % 8);
374330e2 1272 biglen = len + pad;
1273
ff3187f6 1274 pkt->length = len - 5;
1275 if (pkt->maxlen < biglen) {
1276 pkt->maxlen = biglen;
1277 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
374330e2 1278 }
ff3187f6 1279 pkt->body = pkt->data + 4 + pad + 1;
4ba9b64b 1280}
374330e2 1281
ff3187f6 1282static struct Packet *s_wrpkt_start(int type, int len)
32874aea 1283{
ff3187f6 1284 struct Packet *pkt = ssh_new_packet();
1285 ssh1_pktout_size(pkt, len);
1286 pkt->type = type;
9a10ecf4 1287 /* Initialise log omission state */
ff3187f6 1288 pkt->nblanks = 0;
1289 pkt->blanks = NULL;
1290 return pkt;
374330e2 1291}
1292
ff3187f6 1293static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
32874aea 1294{
fd7a4aad 1295 int pad, biglen, i;
374330e2 1296 unsigned long crc;
fd7a4aad 1297#ifdef __SC__
1298 /*
1299 * XXX various versions of SC (including 8.8.4) screw up the
1300 * register allocation in this function and use the same register
1301 * (D6) for len and as a temporary, with predictable results. The
1302 * following sledgehammer prevents this.
1303 */
1304 volatile
1305#endif
1306 int len;
374330e2 1307
ff3187f6 1308 pkt->body[-1] = pkt->type;
4ba9b64b 1309
a8327734 1310 if (ssh->logctx)
ff3187f6 1311 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1312 ssh1_pkt_type(pkt->type),
1313 pkt->body, pkt->length,
1314 pkt->nblanks, pkt->blanks);
1315 sfree(pkt->blanks); pkt->blanks = NULL;
1316 pkt->nblanks = 0;
00db133f 1317
51470298 1318 if (ssh->v1_compressing) {
4ba9b64b 1319 unsigned char *compblk;
1320 int complen;
5366aed8 1321 zlib_compress_block(ssh->cs_comp_ctx,
ff3187f6 1322 pkt->body - 1, pkt->length + 1,
4ba9b64b 1323 &compblk, &complen);
ff3187f6 1324 ssh1_pktout_size(pkt, complen - 1);
1325 memcpy(pkt->body - 1, compblk, complen);
dcbde236 1326 sfree(compblk);
4ba9b64b 1327 }
1328
ff3187f6 1329 len = pkt->length + 5; /* type and CRC */
32874aea 1330 pad = 8 - (len % 8);
374330e2 1331 biglen = len + pad;
1332
32874aea 1333 for (i = 0; i < pad; i++)
ff3187f6 1334 pkt->data[i + 4] = random_byte();
1335 crc = crc32_compute(pkt->data + 4, biglen - 4);
1336 PUT_32BIT(pkt->data + biglen, crc);
1337 PUT_32BIT(pkt->data, len);
374330e2 1338
51470298 1339 if (ssh->cipher)
ff3187f6 1340 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
374330e2 1341
32874aea 1342 return biglen + 4;
39065bed 1343}
1344
ff3187f6 1345static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1346{
5471d09a 1347 int len, backlog;
ff3187f6 1348 len = s_wrpkt_prepare(ssh, pkt);
1349 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1350 if (backlog > SSH_MAX_BACKLOG)
51470298 1351 ssh_throttle_all(ssh, 1, backlog);
39065bed 1352}
1353
ff3187f6 1354static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1355{
39065bed 1356 int len;
ff3187f6 1357 len = s_wrpkt_prepare(ssh, pkt);
51470298 1358 if (ssh->deferred_len + len > ssh->deferred_size) {
1359 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1360 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1361 ssh->deferred_size,
1362 unsigned char);
39065bed 1363 }
ff3187f6 1364 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1365 ssh->deferred_len += len;
374330e2 1366}
1367
fb09bf1c 1368/*
39065bed 1369 * Construct a packet with the specified contents.
fb09bf1c 1370 */
ff3187f6 1371static struct Packet *construct_packet(Ssh ssh, int pkttype,
1372 va_list ap1, va_list ap2)
fb09bf1c 1373{
fb09bf1c 1374 unsigned char *p, *argp, argchar;
1375 unsigned long argint;
1376 int pktlen, argtype, arglen;
7cca0d81 1377 Bignum bn;
ff3187f6 1378 struct Packet *pkt;
fb09bf1c 1379
1380 pktlen = 0;
39065bed 1381 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1382 switch (argtype) {
1383 case PKT_INT:
39065bed 1384 (void) va_arg(ap1, int);
fb09bf1c 1385 pktlen += 4;
1386 break;
1387 case PKT_CHAR:
1ec39246 1388 (void) va_arg(ap1, int);
fb09bf1c 1389 pktlen++;
1390 break;
1391 case PKT_DATA:
39065bed 1392 (void) va_arg(ap1, unsigned char *);
1393 arglen = va_arg(ap1, int);
fb09bf1c 1394 pktlen += arglen;
1395 break;
1396 case PKT_STR:
39065bed 1397 argp = va_arg(ap1, unsigned char *);
d8baa528 1398 arglen = strlen((char *)argp);
fb09bf1c 1399 pktlen += 4 + arglen;
1400 break;
7cca0d81 1401 case PKT_BIGNUM:
39065bed 1402 bn = va_arg(ap1, Bignum);
32874aea 1403 pktlen += ssh1_bignum_length(bn);
7cca0d81 1404 break;
9a10ecf4 1405 case PKTT_PASSWORD:
1406 case PKTT_DATA:
1407 case PKTT_OTHER:
1408 /* ignore this pass */
1409 break;
fb09bf1c 1410 default:
1411 assert(0);
1412 }
1413 }
fb09bf1c 1414
ff3187f6 1415 pkt = s_wrpkt_start(pkttype, pktlen);
1416 p = pkt->body;
fb09bf1c 1417
39065bed 1418 while ((argtype = va_arg(ap2, int)) != PKT_END) {
ff3187f6 1419 int offset = p - pkt->body, len = 0;
fb09bf1c 1420 switch (argtype) {
9a10ecf4 1421 /* Actual fields in the packet */
fb09bf1c 1422 case PKT_INT:
39065bed 1423 argint = va_arg(ap2, int);
fb09bf1c 1424 PUT_32BIT(p, argint);
9a10ecf4 1425 len = 4;
fb09bf1c 1426 break;
1427 case PKT_CHAR:
1ec39246 1428 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1429 *p = argchar;
9a10ecf4 1430 len = 1;
fb09bf1c 1431 break;
1432 case PKT_DATA:
39065bed 1433 argp = va_arg(ap2, unsigned char *);
1434 arglen = va_arg(ap2, int);
fb09bf1c 1435 memcpy(p, argp, arglen);
9a10ecf4 1436 len = arglen;
fb09bf1c 1437 break;
1438 case PKT_STR:
39065bed 1439 argp = va_arg(ap2, unsigned char *);
d8baa528 1440 arglen = strlen((char *)argp);
fb09bf1c 1441 PUT_32BIT(p, arglen);
1442 memcpy(p + 4, argp, arglen);
9a10ecf4 1443 len = arglen + 4;
fb09bf1c 1444 break;
7cca0d81 1445 case PKT_BIGNUM:
39065bed 1446 bn = va_arg(ap2, Bignum);
9a10ecf4 1447 len = ssh1_write_bignum(p, bn);
1448 break;
1449 /* Tokens for modifications to packet logging */
1450 case PKTT_PASSWORD:
ff3187f6 1451 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1452 break;
1453 case PKTT_DATA:
ff3187f6 1454 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1455 break;
9a10ecf4 1456 case PKTT_OTHER:
ff3187f6 1457 end_log_omission(ssh, pkt);
9a10ecf4 1458 break;
1459 }
1460 p += len;
1461 /* Deal with logfile omission, if required. */
ff3187f6 1462 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1463 pkt->nblanks++;
1464 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1465 struct logblank_t);
1466 pkt->blanks[pkt->nblanks-1].offset = offset;
1467 pkt->blanks[pkt->nblanks-1].len = len;
1468 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
fb09bf1c 1469 }
1470 }
ff3187f6 1471
1472 return pkt;
39065bed 1473}
fb09bf1c 1474
51470298 1475static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1476{
ff3187f6 1477 struct Packet *pkt;
39065bed 1478 va_list ap1, ap2;
1479 va_start(ap1, pkttype);
1480 va_start(ap2, pkttype);
ff3187f6 1481 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1482 va_end(ap2);
1483 va_end(ap1);
1484 s_wrpkt(ssh, pkt);
1485 ssh_free_packet(pkt);
fb09bf1c 1486}
1487
51470298 1488static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1489{
ff3187f6 1490 struct Packet *pkt;
39065bed 1491 va_list ap1, ap2;
1492 va_start(ap1, pkttype);
1493 va_start(ap2, pkttype);
ff3187f6 1494 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1495 va_end(ap2);
1496 va_end(ap1);
1497 s_wrpkt_defer(ssh, pkt);
1498 ssh_free_packet(pkt);
39065bed 1499}
1500
32874aea 1501static int ssh_versioncmp(char *a, char *b)
1502{
9697bfd2 1503 char *ae, *be;
1504 unsigned long av, bv;
1505
43aa02a7 1506 av = strtoul(a, &ae, 10);
1507 bv = strtoul(b, &be, 10);
32874aea 1508 if (av != bv)
1509 return (av < bv ? -1 : +1);
1510 if (*ae == '.')
1511 ae++;
1512 if (*be == '.')
1513 be++;
43aa02a7 1514 av = strtoul(ae, &ae, 10);
1515 bv = strtoul(be, &be, 10);
32874aea 1516 if (av != bv)
1517 return (av < bv ? -1 : +1);
9697bfd2 1518 return 0;
1519}
1520
e5574168 1521/*
a92dd380 1522 * Utility routines for putting an SSH-protocol `string' and
1523 * `uint32' into a SHA state.
e5574168 1524 */
1525#include <stdio.h>
32874aea 1526static void sha_string(SHA_State * s, void *str, int len)
1527{
e5574168 1528 unsigned char lenblk[4];
e5574168 1529 PUT_32BIT(lenblk, len);
e5574168 1530 SHA_Bytes(s, lenblk, 4);
e5574168 1531 SHA_Bytes(s, str, len);
1532}
1533
32874aea 1534static void sha_uint32(SHA_State * s, unsigned i)
1535{
a92dd380 1536 unsigned char intblk[4];
1537 PUT_32BIT(intblk, i);
1538 SHA_Bytes(s, intblk, 4);
1539}
1540
7cca0d81 1541/*
1542 * SSH2 packet construction functions.
1543 */
ff3187f6 1544static void ssh2_pkt_ensure(struct Packet *pkt, int length)
32874aea 1545{
ff3187f6 1546 if (pkt->maxlen < length) {
1547 pkt->maxlen = length + 256;
1548 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
7cca0d81 1549 }
783415f8 1550}
ff3187f6 1551static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1552{
ff3187f6 1553 if (pkt->logmode != PKTLOG_EMIT) {
1554 pkt->nblanks++;
1555 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1556 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1557 pkt->blanks[pkt->nblanks-1].len = len;
1558 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1559 }
1560 pkt->length += len;
1561 ssh2_pkt_ensure(pkt, pkt->length);
1562 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1563}
ff3187f6 1564static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1565{
ff3187f6 1566 ssh2_pkt_adddata(pkt, &byte, 1);
7cca0d81 1567}
ff3187f6 1568static struct Packet *ssh2_pkt_init(int pkt_type)
32874aea 1569{
ff3187f6 1570 struct Packet *pkt = ssh_new_packet();
1571 pkt->length = 5;
1572 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1573 return pkt;
7cca0d81 1574}
ff3187f6 1575static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1576{
ff3187f6 1577 ssh2_pkt_adddata(pkt, &value, 1);
7cca0d81 1578}
ff3187f6 1579static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1580{
7cca0d81 1581 unsigned char x[4];
1582 PUT_32BIT(x, value);
ff3187f6 1583 ssh2_pkt_adddata(pkt, x, 4);
7cca0d81 1584}
ff3187f6 1585static void ssh2_pkt_addstring_start(struct Packet *pkt)
32874aea 1586{
ff3187f6 1587 ssh2_pkt_adduint32(pkt, 0);
1588 pkt->savedpos = pkt->length;
7cca0d81 1589}
ff3187f6 1590static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1591{
ff3187f6 1592 ssh2_pkt_adddata(pkt, data, strlen(data));
1593 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1594}
ff3187f6 1595static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1596{
ff3187f6 1597 ssh2_pkt_adddata(pkt, data, len);
1598 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1599}
ff3187f6 1600static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
32874aea 1601{
ff3187f6 1602 ssh2_pkt_addstring_start(pkt);
1603 ssh2_pkt_addstring_str(pkt, data);
7cca0d81 1604}
d8baa528 1605static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1606{
7cca0d81 1607 unsigned char *p;
32874aea 1608 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1609 p = snewn(n + 1, unsigned char);
7cca0d81 1610 if (!p)
32874aea 1611 fatalbox("out of memory");
7cca0d81 1612 p[0] = 0;
3709bfe9 1613 for (i = 1; i <= n; i++)
32874aea 1614 p[i] = bignum_byte(b, n - i);
7cca0d81 1615 i = 0;
32874aea 1616 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1617 i++;
1618 memmove(p, p + i, n + 1 - i);
1619 *len = n + 1 - i;
7cca0d81 1620 return p;
1621}
ff3187f6 1622static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1623{
7cca0d81 1624 unsigned char *p;
1625 int len;
1626 p = ssh2_mpint_fmt(b, &len);
ff3187f6 1627 ssh2_pkt_addstring_start(pkt);
1628 ssh2_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1629 sfree(p);
7cca0d81 1630}
b185170a 1631
1632/*
1633 * Construct an SSH2 final-form packet: compress it, encrypt it,
1634 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1635 * pkt->data. Total length is returned.
b185170a 1636 */
ff3187f6 1637static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1638{
7cca0d81 1639 int cipherblk, maclen, padding, i;
7cca0d81 1640
a8327734 1641 if (ssh->logctx)
ff3187f6 1642 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1643 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1644 pkt->data + 6, pkt->length - 6,
1645 pkt->nblanks, pkt->blanks);
1646 sfree(pkt->blanks); pkt->blanks = NULL;
1647 pkt->nblanks = 0;
00db133f 1648
7cca0d81 1649 /*
4ba9b64b 1650 * Compress packet payload.
1651 */
4ba9b64b 1652 {
1653 unsigned char *newpayload;
1654 int newlen;
51470298 1655 if (ssh->cscomp &&
ff3187f6 1656 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1657 pkt->length - 5,
51470298 1658 &newpayload, &newlen)) {
ff3187f6 1659 pkt->length = 5;
1660 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1661 sfree(newpayload);
4ba9b64b 1662 }
1663 }
1664
1665 /*
7cca0d81 1666 * Add padding. At least four bytes, and must also bring total
1667 * length (minus MAC) up to a multiple of the block size.
1668 */
51470298 1669 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1670 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1671 padding = 4;
32874aea 1672 padding +=
ff3187f6 1673 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
51470298 1674 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1675 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1676 pkt->data[4] = padding;
7cca0d81 1677 for (i = 0; i < padding; i++)
ff3187f6 1678 pkt->data[pkt->length + i] = random_byte();
1679 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1680 if (ssh->csmac)
ff3187f6 1681 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1682 pkt->length + padding,
51470298 1683 ssh->v2_outgoing_sequence);
1684 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1685
1686 if (ssh->cscipher)
371e569c 1687 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1688 pkt->data, pkt->length + padding);
51470298 1689
9442dd57 1690 pkt->encrypted_len = pkt->length + padding;
1691
ff3187f6 1692 /* Ready-to-send packet starts at pkt->data. We return length. */
1693 return pkt->length + padding + maclen;
b185170a 1694}
1695
1696/*
590f6a5f 1697 * Routines called from the main SSH code to send packets. There
1698 * are quite a few of these, because we have two separate
1699 * mechanisms for delaying the sending of packets:
1700 *
1701 * - In order to send an IGNORE message and a password message in
1702 * a single fixed-length blob, we require the ability to
1703 * concatenate the encrypted forms of those two packets _into_ a
1704 * single blob and then pass it to our <network.h> transport
1705 * layer in one go. Hence, there's a deferment mechanism which
1706 * works after packet encryption.
1707 *
1708 * - In order to avoid sending any connection-layer messages
1709 * during repeat key exchange, we have to queue up any such
1710 * outgoing messages _before_ they are encrypted (and in
1711 * particular before they're allocated sequence numbers), and
1712 * then send them once we've finished.
1713 *
1714 * I call these mechanisms `defer' and `queue' respectively, so as
1715 * to distinguish them reasonably easily.
1716 *
1717 * The functions send_noqueue() and defer_noqueue() free the packet
1718 * structure they are passed. Every outgoing packet goes through
1719 * precisely one of these functions in its life; packets passed to
1720 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1721 * these or get queued, and then when the queue is later emptied
1722 * the packets are all passed to defer_noqueue().
b185170a 1723 */
590f6a5f 1724
1725/*
1726 * Send an SSH2 packet immediately, without queuing or deferring.
1727 */
1728static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1729{
5471d09a 1730 int len;
1731 int backlog;
ff3187f6 1732 len = ssh2_pkt_construct(ssh, pkt);
1733 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1734 if (backlog > SSH_MAX_BACKLOG)
51470298 1735 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1736
1737 ssh->outgoing_data_size += pkt->encrypted_len;
1738 if (!ssh->kex_in_progress &&
d57f70af 1739 ssh->max_data_size != 0 &&
1740 ssh->outgoing_data_size > ssh->max_data_size)
9442dd57 1741 do_ssh2_transport(ssh, "Initiating key re-exchange "
1742 "(too much data sent)", -1, NULL);
1743
ff3187f6 1744 ssh_free_packet(pkt);
b185170a 1745}
1746
1747/*
590f6a5f 1748 * Defer an SSH2 packet.
b185170a 1749 */
590f6a5f 1750static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1751{
ff3187f6 1752 int len = ssh2_pkt_construct(ssh, pkt);
51470298 1753 if (ssh->deferred_len + len > ssh->deferred_size) {
1754 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1755 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1756 ssh->deferred_size,
1757 unsigned char);
b185170a 1758 }
ff3187f6 1759 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1760 ssh->deferred_len += len;
9442dd57 1761 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1762 ssh_free_packet(pkt);
b185170a 1763}
1764
1765/*
590f6a5f 1766 * Queue an SSH2 packet.
1767 */
1768static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1769{
1770 assert(ssh->queueing);
1771
1772 if (ssh->queuelen >= ssh->queuesize) {
1773 ssh->queuesize = ssh->queuelen + 32;
1774 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1775 }
1776
1777 ssh->queue[ssh->queuelen++] = pkt;
1778}
1779
1780/*
1781 * Either queue or send a packet, depending on whether queueing is
1782 * set.
1783 */
1784static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1785{
1786 if (ssh->queueing)
1787 ssh2_pkt_queue(ssh, pkt);
1788 else
1789 ssh2_pkt_send_noqueue(ssh, pkt);
1790}
1791
1792/*
1793 * Either queue or defer a packet, depending on whether queueing is
1794 * set.
1795 */
1796static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1797{
1798 if (ssh->queueing)
1799 ssh2_pkt_queue(ssh, pkt);
1800 else
1801 ssh2_pkt_defer_noqueue(ssh, pkt);
1802}
1803
1804/*
b185170a 1805 * Send the whole deferred data block constructed by
39065bed 1806 * ssh2_pkt_defer() or SSH1's defer_packet().
590f6a5f 1807 *
1808 * The expected use of the defer mechanism is that you call
1809 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1810 * not currently queueing, this simply sets up deferred_send_data
1811 * and then sends it. If we _are_ currently queueing, the calls to
1812 * ssh2_pkt_defer() put the deferred packets on to the queue
1813 * instead, and therefore ssh_pkt_defersend() has no deferred data
1814 * to send. Hence, there's no need to make it conditional on
1815 * ssh->queueing.
b185170a 1816 */
51470298 1817static void ssh_pkt_defersend(Ssh ssh)
32874aea 1818{
5471d09a 1819 int backlog;
d8baa528 1820 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1821 ssh->deferred_len);
51470298 1822 ssh->deferred_len = ssh->deferred_size = 0;
1823 sfree(ssh->deferred_send_data);
1824 ssh->deferred_send_data = NULL;
5471d09a 1825 if (backlog > SSH_MAX_BACKLOG)
51470298 1826 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1827
1828 ssh->outgoing_data_size += ssh->deferred_data_size;
1829 if (!ssh->kex_in_progress &&
d57f70af 1830 ssh->max_data_size != 0 &&
1831 ssh->outgoing_data_size > ssh->max_data_size)
9442dd57 1832 do_ssh2_transport(ssh, "Initiating key re-exchange "
1833 "(too much data sent)", -1, NULL);
1834 ssh->deferred_data_size = 0;
7cca0d81 1835}
1836
590f6a5f 1837/*
1838 * Send all queued SSH2 packets. We send them by means of
1839 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1840 * packets that needed to be lumped together.
1841 */
1842static void ssh2_pkt_queuesend(Ssh ssh)
1843{
1844 int i;
1845
1846 assert(!ssh->queueing);
1847
1848 for (i = 0; i < ssh->queuelen; i++)
1849 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1850 ssh->queuelen = 0;
1851
1852 ssh_pkt_defersend(ssh);
1853}
1854
7cca0d81 1855#if 0
32874aea 1856void bndebug(char *string, Bignum b)
1857{
7cca0d81 1858 unsigned char *p;
1859 int i, len;
1860 p = ssh2_mpint_fmt(b, &len);
1861 debug(("%s", string));
1862 for (i = 0; i < len; i++)
32874aea 1863 debug((" %02x", p[i]));
765c4200 1864 debug(("\n"));
dcbde236 1865 sfree(p);
7cca0d81 1866}
1867#endif
1868
32874aea 1869static void sha_mpint(SHA_State * s, Bignum b)
1870{
7cca0d81 1871 unsigned char *p;
1872 int len;
1873 p = ssh2_mpint_fmt(b, &len);
1874 sha_string(s, p, len);
dcbde236 1875 sfree(p);
7cca0d81 1876}
1877
1878/*
0016d70b 1879 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1880 */
ff3187f6 1881static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1882{
7cca0d81 1883 unsigned long value;
ff3187f6 1884 if (pkt->length - pkt->savedpos < 4)
32874aea 1885 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1886 value = GET_32BIT(pkt->body + pkt->savedpos);
1887 pkt->savedpos += 4;
7cca0d81 1888 return value;
1889}
ff3187f6 1890static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1891{
65a22376 1892 unsigned long value;
ff3187f6 1893 if (pkt->length - pkt->savedpos < 1)
32874aea 1894 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1895 value = pkt->body[pkt->savedpos] != 0;
1896 pkt->savedpos++;
65a22376 1897 return value;
1898}
ff3187f6 1899static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 1900{
57356d63 1901 int len;
7cca0d81 1902 *p = NULL;
45068b27 1903 *length = 0;
ff3187f6 1904 if (pkt->length - pkt->savedpos < 4)
32874aea 1905 return;
ff3187f6 1906 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 1907 if (len < 0)
1908 return;
1909 *length = len;
ff3187f6 1910 pkt->savedpos += 4;
1911 if (pkt->length - pkt->savedpos < *length)
32874aea 1912 return;
ff3187f6 1913 *p = (char *)(pkt->body + pkt->savedpos);
1914 pkt->savedpos += *length;
7cca0d81 1915}
ff3187f6 1916static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 1917{
ff3187f6 1918 if (pkt->length - pkt->savedpos < length)
0016d70b 1919 return NULL;
ff3187f6 1920 pkt->savedpos += length;
1921 return pkt->body + (pkt->savedpos - length);
0016d70b 1922}
ff3187f6 1923static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 1924 unsigned char **keystr)
1925{
1926 int j;
1927
ff3187f6 1928 j = makekey(pkt->body + pkt->savedpos,
1929 pkt->length - pkt->savedpos,
0016d70b 1930 key, keystr, 0);
1931
1932 if (j < 0)
1933 return FALSE;
1934
ff3187f6 1935 pkt->savedpos += j;
1936 assert(pkt->savedpos < pkt->length);
0016d70b 1937
1938 return TRUE;
1939}
ff3187f6 1940static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 1941{
1942 int j;
1943 Bignum b;
1944
ff3187f6 1945 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1946 pkt->length - pkt->savedpos, &b);
0016d70b 1947
1948 if (j < 0)
1949 return NULL;
1950
ff3187f6 1951 pkt->savedpos += j;
0016d70b 1952 return b;
1953}
ff3187f6 1954static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 1955{
7cca0d81 1956 char *p;
3709bfe9 1957 int length;
7cca0d81 1958 Bignum b;
1959
ff3187f6 1960 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 1961 if (!p)
32874aea 1962 return NULL;
ff3187f6 1963 if (p[0] & 0x80)
32874aea 1964 return NULL;
d8baa528 1965 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1966 return b;
1967}
1968
7d503c31 1969/*
1dd353b5 1970 * Helper function to add an SSH2 signature blob to a packet.
1971 * Expects to be shown the public key blob as well as the signature
1972 * blob. Normally works just like ssh2_pkt_addstring, but will
1973 * fiddle with the signature packet if necessary for
1974 * BUG_SSH2_RSA_PADDING.
1975 */
ff3187f6 1976static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1977 void *pkblob_v, int pkblob_len,
1dd353b5 1978 void *sigblob_v, int sigblob_len)
1979{
1980 unsigned char *pkblob = (unsigned char *)pkblob_v;
1981 unsigned char *sigblob = (unsigned char *)sigblob_v;
1982
1983 /* dmemdump(pkblob, pkblob_len); */
1984 /* dmemdump(sigblob, sigblob_len); */
1985
1986 /*
1987 * See if this is in fact an ssh-rsa signature and a buggy
1988 * server; otherwise we can just do this the easy way.
1989 */
51470298 1990 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1991 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1992 int pos, len, siglen;
1993
1994 /*
1995 * Find the byte length of the modulus.
1996 */
1997
1998 pos = 4+7; /* skip over "ssh-rsa" */
1999 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2000 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2001 pos += 4; /* find modulus itself */
2002 while (len > 0 && pkblob[pos] == 0)
2003 len--, pos++;
2004 /* debug(("modulus length is %d\n", len)); */
2005
2006 /*
2007 * Now find the signature integer.
2008 */
2009 pos = 4+7; /* skip over "ssh-rsa" */
2010 siglen = GET_32BIT(sigblob+pos);
2011 /* debug(("signature length is %d\n", siglen)); */
2012
2013 if (len != siglen) {
2014 unsigned char newlen[4];
ff3187f6 2015 ssh2_pkt_addstring_start(pkt);
2016 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2017 /* dmemdump(sigblob, pos); */
2018 pos += 4; /* point to start of actual sig */
2019 PUT_32BIT(newlen, len);
ff3187f6 2020 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2021 /* dmemdump(newlen, 4); */
2022 newlen[0] = 0;
2023 while (len-- > siglen) {
ff3187f6 2024 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2025 /* dmemdump(newlen, 1); */
2026 }
ff3187f6 2027 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2028 /* dmemdump(sigblob+pos, siglen); */
2029 return;
2030 }
2031
2032 /* Otherwise fall through and do it the easy way. */
2033 }
2034
ff3187f6 2035 ssh2_pkt_addstring_start(pkt);
2036 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2037}
2038
2039/*
7d503c31 2040 * Examine the remote side's version string and compare it against
2041 * a list of known buggy implementations.
2042 */
51470298 2043static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2044{
2045 char *imp; /* pointer to implementation part */
7d503c31 2046 imp = vstring;
2047 imp += strcspn(imp, "-");
bd358db1 2048 if (*imp) imp++;
7d503c31 2049 imp += strcspn(imp, "-");
bd358db1 2050 if (*imp) imp++;
7d503c31 2051
51470298 2052 ssh->remote_bugs = 0;
7d503c31 2053
5ecd7ad0 2054 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2055 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 2056 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2057 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2058 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2059 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2060 /*
2061 * These versions don't support SSH1_MSG_IGNORE, so we have
2062 * to use a different defence against password length
2063 * sniffing.
2064 */
51470298 2065 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 2066 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 2067 }
2068
5ecd7ad0 2069 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2070 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 2071 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2072 /*
2073 * These versions need a plain password sent; they can't
2074 * handle having a null and a random length of data after
2075 * the password.
2076 */
51470298 2077 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 2078 logevent("We believe remote version needs a plain SSH1 password");
2079 }
2080
5ecd7ad0 2081 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2082 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2083 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2084 /*
2085 * These versions apparently have no clue whatever about
2086 * RSA authentication and will panic and die if they see
2087 * an AUTH_RSA message.
2088 */
51470298 2089 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 2090 logevent("We believe remote version can't handle RSA authentication");
2091 }
2092
5ecd7ad0 2093 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2094 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2095 !wc_match("* VShell", imp) &&
831301f6 2096 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2097 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2098 wc_match("2.1 *", imp)))) {
32874aea 2099 /*
2100 * These versions have the HMAC bug.
2101 */
51470298 2102 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2103 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2104 }
1dd353b5 2105
5ecd7ad0 2106 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2107 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2108 !wc_match("* VShell", imp) &&
2856a1b9 2109 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2110 /*
2111 * These versions have the key-derivation bug (failing to
2112 * include the literal shared secret in the hashes that
2113 * generate the keys).
2114 */
51470298 2115 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2116 logevent("We believe remote version has SSH2 key-derivation bug");
2117 }
2118
5ecd7ad0 2119 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2120 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2121 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2122 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2123 /*
2124 * These versions have the SSH2 RSA padding bug.
2125 */
51470298 2126 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2127 logevent("We believe remote version has SSH2 RSA padding bug");
2128 }
8e975795 2129
dda87a28 2130 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2131 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2132 wc_match("OpenSSH_2.[0-2]*", imp))) {
2133 /*
2134 * These versions have the SSH2 session-ID bug in
2135 * public-key authentication.
2136 */
2137 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2138 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2139 }
7d503c31 2140}
2141
d38d6a1f 2142/*
2143 * The `software version' part of an SSH version string is required
2144 * to contain no spaces or minus signs.
2145 */
2146static void ssh_fix_verstring(char *str)
2147{
2148 /* Eat "SSH-<protoversion>-". */
2149 assert(*str == 'S'); str++;
2150 assert(*str == 'S'); str++;
2151 assert(*str == 'H'); str++;
2152 assert(*str == '-'); str++;
2153 while (*str && *str != '-') str++;
2154 assert(*str == '-'); str++;
2155
2156 /* Convert minus signs and spaces in the remaining string into
2157 * underscores. */
2158 while (*str) {
2159 if (*str == '-' || *str == ' ')
2160 *str = '_';
2161 str++;
2162 }
2163}
2164
51470298 2165static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2166{
51470298 2167 struct do_ssh_init_state {
2168 int vslen;
2169 char version[10];
2170 char *vstring;
2171 int vstrsize;
2172 int i;
2173 int proto1, proto2;
2174 };
2175 crState(do_ssh_init_state);
374330e2 2176
51470298 2177 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2178
2179 /* Search for the string "SSH-" in the input. */
51470298 2180 s->i = 0;
8df7a775 2181 while (1) {
2182 static const int transS[] = { 1, 2, 2, 1 };
2183 static const int transH[] = { 0, 0, 3, 0 };
2184 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2185 if (c == 'S')
51470298 2186 s->i = transS[s->i];
32874aea 2187 else if (c == 'H')
51470298 2188 s->i = transH[s->i];
32874aea 2189 else if (c == '-')
51470298 2190 s->i = transminus[s->i];
32874aea 2191 else
51470298 2192 s->i = 0;
2193 if (s->i < 0)
8df7a775 2194 break;
2195 crReturn(1); /* get another character */
374330e2 2196 }
8df7a775 2197
51470298 2198 s->vstrsize = 16;
3d88e64d 2199 s->vstring = snewn(s->vstrsize, char);
51470298 2200 strcpy(s->vstring, "SSH-");
2201 s->vslen = 4;
2202 s->i = 0;
374330e2 2203 while (1) {
8df7a775 2204 crReturn(1); /* get another char */
51470298 2205 if (s->vslen >= s->vstrsize - 1) {
2206 s->vstrsize += 16;
3d88e64d 2207 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2208 }
51470298 2209 s->vstring[s->vslen++] = c;
2210 if (s->i >= 0) {
374330e2 2211 if (c == '-') {
51470298 2212 s->version[s->i] = '\0';
2213 s->i = -1;
2214 } else if (s->i < sizeof(s->version) - 1)
2215 s->version[s->i++] = c;
c4ffc4d0 2216 } else if (c == '\012')
374330e2 2217 break;
2218 }
2219
51470298 2220 ssh->agentfwd_enabled = FALSE;
2221 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2222
51470298 2223 s->vstring[s->vslen] = 0;
a7d4653a 2224 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
51470298 2225 {
2226 char *vlog;
3d88e64d 2227 vlog = snewn(20 + s->vslen, char);
51470298 2228 sprintf(vlog, "Server version: %s", s->vstring);
2229 logevent(vlog);
2230 sfree(vlog);
2231 }
2232 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2233
adf799dd 2234 /*
38d228a2 2235 * Decide which SSH protocol version to support.
adf799dd 2236 */
38d228a2 2237
2238 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2239 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2240 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2241 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2242
86916870 2243 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2244 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2245 crStop(0);
38d228a2 2246 }
86916870 2247 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2248 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2249 crStop(0);
38d228a2 2250 }
2251
d38d6a1f 2252 {
2253 char *verstring;
2254
2255 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2256 /*
2257 * Construct a v2 version string.
2258 */
a7d4653a 2259 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
d38d6a1f 2260 ssh->version = 2;
2261 } else {
2262 /*
2263 * Construct a v1 version string.
2264 */
a7d4653a 2265 verstring = dupprintf("SSH-%s-%s\012",
d38d6a1f 2266 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2267 s->version : "1.5"),
2268 sshver);
2269 ssh->version = 1;
2270 }
2271
2272 ssh_fix_verstring(verstring);
2273
2274 if (ssh->version == 2) {
2275 /*
2276 * Hash our version string and their version string.
2277 */
2278 SHA_Init(&ssh->exhashbase);
0b351b6b 2279 sha_string(&ssh->exhashbase, verstring,
a7d4653a 2280 strcspn(verstring, "\015\012"));
0b351b6b 2281 sha_string(&ssh->exhashbase, s->vstring,
a7d4653a 2282 strcspn(s->vstring, "\015\012"));
d38d6a1f 2283
2284 /*
2285 * Initialise SSHv2 protocol.
2286 */
2287 ssh->protocol = ssh2_protocol;
2288 ssh2_protocol_setup(ssh);
2289 ssh->s_rdpkt = ssh2_rdpkt;
2290 } else {
2291 /*
2292 * Initialise SSHv1 protocol.
2293 */
2294 ssh->protocol = ssh1_protocol;
2295 ssh1_protocol_setup(ssh);
2296 ssh->s_rdpkt = ssh1_rdpkt;
2297 }
2298 logeventf(ssh, "We claim version: %.*s",
a7d4653a 2299 strcspn(verstring, "\015\012"), verstring);
51470298 2300 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2301 sfree(verstring);
e5574168 2302 }
d38d6a1f 2303
2304 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2305
125105d1 2306 update_specials_menu(ssh->frontend);
51470298 2307 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2308 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2309
51470298 2310 sfree(s->vstring);
50526e47 2311
8df7a775 2312 crFinish(0);
2313}
2314
51470298 2315static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2316{
51470298 2317 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2318
2319 /*
2320 * To begin with, feed the characters one by one to the
2321 * protocol initialisation / selection function do_ssh_init().
2322 * When that returns 0, we're done with the initial greeting
2323 * exchange and can move on to packet discipline.
2324 */
2325 while (1) {
51470298 2326 int ret; /* need not be kept across crReturn */
8df7a775 2327 if (datalen == 0)
2328 crReturnV; /* more data please */
51470298 2329 ret = do_ssh_init(ssh, *data);
32874aea 2330 data++;
2331 datalen--;
8df7a775 2332 if (ret == 0)
2333 break;
2334 }
2335
2336 /*
2337 * We emerge from that loop when the initial negotiation is
2338 * over and we have selected an s_rdpkt function. Now pass
2339 * everything to s_rdpkt, and then pass the resulting packets
2340 * to the proper protocol handler.
2341 */
2342 if (datalen == 0)
2343 crReturnV;
2344 while (1) {
2345 while (datalen > 0) {
ff3187f6 2346 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2347 if (pktin) {
2348 ssh->protocol(ssh, NULL, 0, pktin);
2349 ssh_free_packet(pktin);
8df7a775 2350 }
ff3187f6 2351 if (ssh->state == SSH_STATE_CLOSED)
2352 return;
8df7a775 2353 }
2354 crReturnV;
2355 }
2356 crFinishV;
2357}
2358
36f94d1f 2359static void ssh_do_close(Ssh ssh)
32874aea 2360{
36f94d1f 2361 int i;
2362 struct ssh_channel *c;
2363
51470298 2364 ssh->state = SSH_STATE_CLOSED;
2365 if (ssh->s) {
2366 sk_close(ssh->s);
2367 ssh->s = NULL;
39934deb 2368 notify_remote_exit(ssh->frontend);
f3ab576e 2369 }
36f94d1f 2370 /*
2371 * Now we must shut down any port and X forwardings going
2372 * through this connection.
2373 */
74a98066 2374 if (ssh->channels) {
2375 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2376 switch (c->type) {
2377 case CHAN_X11:
2378 x11_close(c->u.x11.s);
2379 break;
2380 case CHAN_SOCKDATA:
2381 pfd_close(c->u.pfd.s);
2382 break;
2383 }
2384 del234(ssh->channels, c);
2385 if (ssh->version == 2)
2386 bufchain_clear(&c->v.v2.outbuffer);
2387 sfree(c);
36f94d1f 2388 }
36f94d1f 2389 }
2390}
2391
cbe2d68f 2392static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2393 int calling_back)
2394{
2395 Ssh ssh = (Ssh) plug;
2396 ssh_do_close(ssh);
7e78000d 2397 if (error_msg) {
32874aea 2398 /* A socket error has occurred. */
247308b5 2399 logevent(error_msg);
971bcc0a 2400 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2401 } else {
2402 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2403 }
7e78000d 2404 return 0;
2405}
2406
32874aea 2407static int ssh_receive(Plug plug, int urgent, char *data, int len)
2408{
51470298 2409 Ssh ssh = (Ssh) plug;
d8baa528 2410 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2411 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2412 ssh_do_close(ssh);
32874aea 2413 return 0;
3257deae 2414 }
fef97f43 2415 return 1;
374330e2 2416}
2417
5471d09a 2418static void ssh_sent(Plug plug, int bufsize)
2419{
51470298 2420 Ssh ssh = (Ssh) plug;
5471d09a 2421 /*
2422 * If the send backlog on the SSH socket itself clears, we
2423 * should unthrottle the whole world if it was throttled.
2424 */
2425 if (bufsize < SSH_MAX_BACKLOG)
51470298 2426 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2427}
2428
fb09bf1c 2429/*
8df7a775 2430 * Connect to specified host and port.
2431 * Returns an error message, or NULL on success.
6e1ebb76 2432 * Also places the canonical host name into `realhost'. It must be
2433 * freed by the caller.
8df7a775 2434 */
cbe2d68f 2435static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2436 char **realhost, int nodelay, int keepalive)
8df7a775 2437{
51470298 2438 static const struct plug_function_table fn_table = {
7e78000d 2439 ssh_closing,
5471d09a 2440 ssh_receive,
2441 ssh_sent,
2442 NULL
51470298 2443 };
7e78000d 2444
8df7a775 2445 SockAddr addr;
cbe2d68f 2446 const char *err;
8df7a775 2447
3d88e64d 2448 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2449 if (!ssh->savedhost)
8df7a775 2450 fatalbox("Out of memory");
51470298 2451 strcpy(ssh->savedhost, host);
8df7a775 2452
2453 if (port < 0)
2454 port = 22; /* default ssh port */
51470298 2455 ssh->savedport = port;
8df7a775 2456
2457 /*
2458 * Try to find host.
2459 */
05581745 2460 logeventf(ssh, "Looking up host \"%s\"%s", host,
2461 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2462 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2463 addr = name_lookup(host, port, realhost, &ssh->cfg,
2464 ssh->cfg.addressfamily);
170c1e6e 2465 if ((err = sk_addr_error(addr)) != NULL) {
2466 sk_addr_free(addr);
8df7a775 2467 return err;
170c1e6e 2468 }
8df7a775 2469
8df7a775 2470 /*
2471 * Open socket.
2472 */
3ad9d396 2473 {
57356d63 2474 char addrbuf[100];
3ad9d396 2475 sk_getaddr(addr, addrbuf, 100);
57356d63 2476 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2477 }
51470298 2478 ssh->fn = &fn_table;
e8fa8f62 2479 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2480 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2481 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2482 ssh->s = NULL;
39934deb 2483 notify_remote_exit(ssh->frontend);
8df7a775 2484 return err;
67c4ba2e 2485 }
8df7a775 2486
8df7a775 2487 return NULL;
2488}
2489
2490/*
5471d09a 2491 * Throttle or unthrottle the SSH connection.
2492 */
51470298 2493static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2494{
51470298 2495 int old_count = ssh->v1_throttle_count;
2496 ssh->v1_throttle_count += adjust;
2497 assert(ssh->v1_throttle_count >= 0);
2498 if (ssh->v1_throttle_count && !old_count) {
2499 sk_set_frozen(ssh->s, 1);
2500 } else if (!ssh->v1_throttle_count && old_count) {
2501 sk_set_frozen(ssh->s, 0);
5471d09a 2502 }
2503}
2504
2505/*
2506 * Throttle or unthrottle _all_ local data streams (for when sends
2507 * on the SSH connection itself back up).
2508 */
51470298 2509static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2510{
2511 int i;
2512 struct ssh_channel *c;
2513
51470298 2514 if (enable == ssh->throttled_all)
5471d09a 2515 return;
51470298 2516 ssh->throttled_all = enable;
2517 ssh->overall_bufsize = bufsize;
2518 if (!ssh->channels)
5471d09a 2519 return;
51470298 2520 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2521 switch (c->type) {
2522 case CHAN_MAINSESSION:
2523 /*
2524 * This is treated separately, outside the switch.
2525 */
2526 break;
2527 case CHAN_X11:
2528 x11_override_throttle(c->u.x11.s, enable);
2529 break;
2530 case CHAN_AGENT:
2531 /* Agent channels require no buffer management. */
2532 break;
2533 case CHAN_SOCKDATA:
36f94d1f 2534 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2535 break;
2536 }
2537 }
2538}
2539
2540/*
51470298 2541 * Username and password input, abstracted off into routines
2542 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2543 */
0405e71f 2544
2545/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2546static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2547{
51470298 2548 ssh->userpass_input_buffer = buffer;
2549 ssh->userpass_input_buflen = buflen;
2550 ssh->userpass_input_bufpos = 0;
2551 ssh->userpass_input_echo = echo;
0405e71f 2552}
2553
2554/*
2555 * Process some terminal data in the course of username/password
2556 * input. Returns >0 for success (line of input returned in
2557 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2558 * for inconclusive (keep waiting for more input please).
2559 */
ae9ae89f 2560static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2561{
2562 char c;
2563
2564 while (inlen--) {
2565 switch (c = *in++) {
2566 case 10:
2567 case 13:
51470298 2568 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2569 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2570 return +1;
2571 break;
2572 case 8:
2573 case 127:
51470298 2574 if (ssh->userpass_input_bufpos > 0) {
2575 if (ssh->userpass_input_echo)
2576 c_write_str(ssh, "\b \b");
2577 ssh->userpass_input_bufpos--;
0405e71f 2578 }
2579 break;
2580 case 21:
2581 case 27:
51470298 2582 while (ssh->userpass_input_bufpos > 0) {
2583 if (ssh->userpass_input_echo)
2584 c_write_str(ssh, "\b \b");
2585 ssh->userpass_input_bufpos--;
0405e71f 2586 }
2587 break;
2588 case 3:
2589 case 4:
2590 return -1;
2591 break;
2592 default:
4692a14a 2593 /*
2594 * This simplistic check for printability is disabled
2595 * when we're doing password input, because some people
2596 * have control characters in their passwords.o
2597 */
2598 if ((!ssh->userpass_input_echo ||
2599 (c >= ' ' && c <= '~') ||
0405e71f 2600 ((unsigned char) c >= 160))
51470298 2601 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2602 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2603 if (ssh->userpass_input_echo)
2604 c_write(ssh, &c, 1);
0405e71f 2605 }
2606 break;
2607 }
2608 }
2609 return 0;
2610}
2611
f11d78f2 2612static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2613{
2614 Ssh ssh = (Ssh) sshv;
2615
2616 ssh->agent_response = reply;
2617 ssh->agent_response_len = replylen;
2618
2619 if (ssh->version == 1)
ff3187f6 2620 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2621 else
ff3187f6 2622 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2623}
2624
f11d78f2 2625static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2626{
2627 struct ssh_channel *c = (struct ssh_channel *)cv;
2628 Ssh ssh = c->ssh;
2629 void *sentreply = reply;
2630
2631 if (!sentreply) {
2632 /* Fake SSH_AGENT_FAILURE. */
2633 sentreply = "\0\0\0\1\5";
2634 replylen = 5;
2635 }
2636 if (ssh->version == 2) {
2637 ssh2_add_channel_data(c, sentreply, replylen);
2638 ssh2_try_send(c);
2639 } else {
2640 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2641 PKT_INT, c->remoteid,
9a10ecf4 2642 PKTT_DATA,
839f10db 2643 PKT_INT, replylen,
2644 PKT_DATA, sentreply, replylen,
9a10ecf4 2645 PKTT_OTHER,
839f10db 2646 PKT_END);
2647 }
2648 if (reply)
2649 sfree(reply);
2650}
2651
0405e71f 2652/*
fb09bf1c 2653 * Handle the key exchange and user authentication phases.
2654 */
ff3187f6 2655static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2656 struct Packet *pktin)
fb09bf1c 2657{
0016d70b 2658 int i, j, ret;
2659 unsigned char cookie[8], *ptr;
374330e2 2660 struct RSAKey servkey, hostkey;
2661 struct MD5Context md5c;
51470298 2662 struct do_ssh1_login_state {
2663 int len;
2664 unsigned char *rsabuf, *keystr1, *keystr2;
2665 unsigned long supported_ciphers_mask, supported_auths_mask;
2666 int tried_publickey, tried_agent;
2667 int tis_auth_refused, ccard_auth_refused;
2668 unsigned char session_id[16];
2669 int cipher_type;
2670 char username[100];
2671 void *publickey_blob;
2672 int publickey_bloblen;
2673 char password[100];
2674 char prompt[200];
2675 int pos;
2676 char c;
2677 int pwpkt_type;
2678 unsigned char request[5], *response, *p;
2679 int responselen;
2680 int keyi, nkeys;
2681 int authed;
2682 struct RSAKey key;
2683 Bignum challenge;
2684 char *commentp;
2685 int commentlen;
2686 };
2687 crState(do_ssh1_login_state);
2688
2689 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2690
ff3187f6 2691 if (!pktin)
2692 crWaitUntil(pktin);
374330e2 2693
ff3187f6 2694 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2695 bombout(("Public key packet not received"));
7ffdbc1a 2696 crStop(0);
8d5de777 2697 }
374330e2 2698
c5e9c988 2699 logevent("Received public keys");
374330e2 2700
ff3187f6 2701 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2702 if (!ptr) {
2703 bombout(("SSH1 public key packet stopped before random cookie"));
2704 crStop(0);
2705 }
2706 memcpy(cookie, ptr, 8);
374330e2 2707
ff3187f6 2708 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2709 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2710 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2711 crStop(0);
2712 }
374330e2 2713
c5e9c988 2714 /*
1c2a93c4 2715 * Log the host key fingerprint.
c5e9c988 2716 */
c5e9c988 2717 {
2718 char logmsg[80];
1c2a93c4 2719 logevent("Host key fingerprint is:");
c5e9c988 2720 strcpy(logmsg, " ");
32874aea 2721 hostkey.comment = NULL;
2722 rsa_fingerprint(logmsg + strlen(logmsg),
2723 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2724 logevent(logmsg);
2725 }
2726
ff3187f6 2727 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2728 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2729 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2730
51470298 2731 ssh->v1_local_protoflags =
2732 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2733 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2734
c5e9c988 2735 MD5Init(&md5c);
51470298 2736 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2737 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2738 MD5Update(&md5c, cookie, 8);
51470298 2739 MD5Final(s->session_id, &md5c);
374330e2 2740
32874aea 2741 for (i = 0; i < 32; i++)
51470298 2742 ssh->session_key[i] = random_byte();
374330e2 2743
0016d70b 2744 /*
2745 * Verify that the `bits' and `bytes' parameters match.
2746 */
2747 if (hostkey.bits > hostkey.bytes * 8 ||
2748 servkey.bits > servkey.bytes * 8) {
2749 bombout(("SSH1 public keys were badly formatted"));
2750 crStop(0);
2751 }
2752
51470298 2753 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2754
3d88e64d 2755 s->rsabuf = snewn(s->len, unsigned char);
51470298 2756 if (!s->rsabuf)
374330e2 2757 fatalbox("Out of memory");
2758
89ee5268 2759 /*
2760 * Verify the host key.
2761 */
2762 {
32874aea 2763 /*
2764 * First format the key into a string.
2765 */
2766 int len = rsastr_len(&hostkey);
2767 char fingerprint[100];
3d88e64d 2768 char *keystr = snewn(len, char);
32874aea 2769 if (!keystr)
2770 fatalbox("Out of memory");
2771 rsastr_fmt(keystr, &hostkey);
2772 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2773 verify_ssh_host_key(ssh->frontend,
2774 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2775 fingerprint);
2776 sfree(keystr);
2777 }
2778
2779 for (i = 0; i < 32; i++) {
51470298 2780 s->rsabuf[i] = ssh->session_key[i];
374330e2 2781 if (i < 16)
51470298 2782 s->rsabuf[i] ^= s->session_id[i];
374330e2 2783 }
2784
2785 if (hostkey.bytes > servkey.bytes) {
0016d70b 2786 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2787 if (ret)
2788 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2789 } else {
0016d70b 2790 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2791 if (ret)
2792 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2793 }
2794 if (!ret) {
2795 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2796 crStop(0);
374330e2 2797 }
2798
c5e9c988 2799 logevent("Encrypted session key");
2800
ca20bfcf 2801 {
2802 int cipher_chosen = 0, warn = 0;
2803 char *cipher_string = NULL;
51470298 2804 int i;
ca20bfcf 2805 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2806 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2807 if (next_cipher == CIPHER_WARN) {
2808 /* If/when we choose a cipher, warn about it */
2809 warn = 1;
2810 } else if (next_cipher == CIPHER_AES) {
2811 /* XXX Probably don't need to mention this. */
2812 logevent("AES not supported in SSH1, skipping");
2813 } else {
2814 switch (next_cipher) {
51470298 2815 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2816 cipher_string = "3DES"; break;
51470298 2817 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2818 cipher_string = "Blowfish"; break;
51470298 2819 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2820 cipher_string = "single-DES"; break;
2821 }
51470298 2822 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2823 cipher_chosen = 1;
2824 }
2825 }
2826 if (!cipher_chosen) {
51470298 2827 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2828 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2829 "supporting 3DES encryption"));
2830 else
2831 /* shouldn't happen */
6b5cf8b4 2832 bombout(("No supported ciphers found"));
7ffdbc1a 2833 crStop(0);
a99a05c0 2834 }
ca20bfcf 2835
2836 /* Warn about chosen cipher if necessary. */
bb348ab1 2837 if (warn) {
2838 sk_set_frozen(ssh->s, 1);
83e7d008 2839 askalg(ssh->frontend, "cipher", cipher_string);
bb348ab1 2840 sk_set_frozen(ssh->s, 0);
2841 }
bea1ef5f 2842 }
ca20bfcf 2843
51470298 2844 switch (s->cipher_type) {
32874aea 2845 case SSH_CIPHER_3DES:
2846 logevent("Using 3DES encryption");
2847 break;
2848 case SSH_CIPHER_DES:
2849 logevent("Using single-DES encryption");
2850 break;
2851 case SSH_CIPHER_BLOWFISH:
2852 logevent("Using Blowfish encryption");
2853 break;
c5e9c988 2854 }
bea1ef5f 2855
51470298 2856 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2857 PKT_CHAR, s->cipher_type,
32874aea 2858 PKT_DATA, cookie, 8,
51470298 2859 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2860 PKT_DATA, s->rsabuf, s->len,
2861 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2862
c5e9c988 2863 logevent("Trying to enable encryption...");
374330e2 2864
51470298 2865 sfree(s->rsabuf);
374330e2 2866
51470298 2867 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2868 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2869 &ssh_3des);
371e569c 2870 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2871 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2872 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2873
0183b242 2874 ssh->crcda_ctx = crcda_make_context();
2875 logevent("Installing CRC compensation attack detector");
2876
679539d7 2877 if (servkey.modulus) {
2878 sfree(servkey.modulus);
2879 servkey.modulus = NULL;
2880 }
2881 if (servkey.exponent) {
2882 sfree(servkey.exponent);
2883 servkey.exponent = NULL;
2884 }
2885 if (hostkey.modulus) {
2886 sfree(hostkey.modulus);
2887 hostkey.modulus = NULL;
2888 }
2889 if (hostkey.exponent) {
2890 sfree(hostkey.exponent);
2891 hostkey.exponent = NULL;
2892 }
ff3187f6 2893 crWaitUntil(pktin);
374330e2 2894
ff3187f6 2895 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2896 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2897 crStop(0);
8d5de777 2898 }
374330e2 2899
c5e9c988 2900 logevent("Successfully started encryption");
2901
374330e2 2902 fflush(stdout);
2903 {
aa09f7d0 2904 if (!*ssh->cfg.username) {
c0a81592 2905 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2906 if (!ssh_get_line("login as: ",
51470298 2907 s->username, sizeof(s->username), FALSE)) {
32874aea 2908 /*
2909 * get_line failed to get a username.
2910 * Terminate.
2911 */
2912 logevent("No username provided. Abandoning session.");
3bb2f322 2913 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2914 crStop(1);
32874aea 2915 }
2916 } else {
51470298 2917 int ret; /* need not be kept over crReturn */
2918 c_write_str(ssh, "login as: ");
2919 ssh->send_ok = 1;
0405e71f 2920
51470298 2921 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2922 do {
ff3187f6 2923 crWaitUntil(!pktin);
51470298 2924 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2925 } while (ret == 0);
2926 if (ret < 0)
2927 cleanup_exit(0);
51470298 2928 c_write_str(ssh, "\r\n");
32874aea 2929 }
2930 } else {
86916870 2931 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2932 s->username[sizeof(s->username)-1] = '\0';
374330e2 2933 }
fb09bf1c 2934
51470298 2935 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2936 {
51470298 2937 char userlog[22 + sizeof(s->username)];
2938 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2939 logevent(userlog);
32874aea 2940 if (flags & FLAG_INTERACTIVE &&
2941 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2942 strcat(userlog, "\r\n");
51470298 2943 c_write_str(ssh, userlog);
3c8e959b 2944 }
c5e9c988 2945 }
374330e2 2946 }
2947
ff3187f6 2948 crWaitUntil(pktin);
374330e2 2949
51470298 2950 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2951 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2952 s->tried_publickey = s->tried_agent = 1;
0df73905 2953 } else {
51470298 2954 s->tried_publickey = s->tried_agent = 0;
0df73905 2955 }
51470298 2956 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2957 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2958 if (!filename_is_null(ssh->cfg.keyfile)) {
2959 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2960 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2961 s->publickey_blob = NULL;
396778f1 2962 } else
51470298 2963 s->publickey_blob = NULL;
7cca0d81 2964
ff3187f6 2965 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 2966 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2967
51470298 2968 if (agent_exists() && !s->tried_agent) {
32874aea 2969 /*
2970 * Attempt RSA authentication using Pageant.
2971 */
32874aea 2972 void *r;
2973
51470298 2974 s->authed = FALSE;
2975 s->tried_agent = 1;
32874aea 2976 logevent("Pageant is running. Requesting keys.");
2977
2978 /* Request the keys held by the agent. */
51470298 2979 PUT_32BIT(s->request, 1);
2980 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2981 if (!agent_query(s->request, 5, &r, &s->responselen,
2982 ssh_agent_callback, ssh)) {
2983 do {
2984 crReturn(0);
ff3187f6 2985 if (pktin) {
839f10db 2986 bombout(("Unexpected data from server while waiting"
2987 " for agent response"));
2988 crStop(0);
2989 }
ff3187f6 2990 } while (pktin || inlen > 0);
839f10db 2991 r = ssh->agent_response;
2992 s->responselen = ssh->agent_response_len;
2993 }
51470298 2994 s->response = (unsigned char *) r;
2995 if (s->response && s->responselen >= 5 &&
2996 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2997 s->p = s->response + 5;
2998 s->nkeys = GET_32BIT(s->p);
2999 s->p += 4;
32874aea 3000 {
3001 char buf[64];
51470298 3002 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 3003 logevent(buf);
3004 }
51470298 3005 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 3006 {
3007 char buf[64];
51470298 3008 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 3009 logevent(buf);
3010 }
51470298 3011 if (s->publickey_blob &&
3012 !memcmp(s->p, s->publickey_blob,
3013 s->publickey_bloblen)) {
396778f1 3014 logevent("This key matches configured key file");
51470298 3015 s->tried_publickey = 1;
396778f1 3016 }
51470298 3017 s->p += 4;
0016d70b 3018 {
3019 int n, ok = FALSE;
3020 do { /* do while (0) to make breaking easy */
3021 n = ssh1_read_bignum
3022 (s->p, s->responselen-(s->p-s->response),
3023 &s->key.exponent);
3024 if (n < 0)
3025 break;
3026 s->p += n;
3027 n = ssh1_read_bignum
3028 (s->p, s->responselen-(s->p-s->response),
3029 &s->key.modulus);
3030 if (n < 0)
3031 break;
3032 s->p += n;
3033 if (s->responselen - (s->p-s->response) < 4)
3034 break;
3035 s->commentlen = GET_32BIT(s->p);
3036 s->p += 4;
3037 if (s->responselen - (s->p-s->response) <
3038 s->commentlen)
3039 break;
3040 s->commentp = (char *)s->p;
3041 s->p += s->commentlen;
3042 ok = TRUE;
3043 } while (0);
3044 if (!ok) {
3045 logevent("Pageant key list packet was truncated");
3046 break;
3047 }
3048 }
51470298 3049 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3050 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3051 crWaitUntil(pktin);
3052 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3053 logevent("Key refused");
3054 continue;
3055 }
3056 logevent("Received RSA challenge");
ff3187f6 3057 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3058 bombout(("Server's RSA challenge was badly formatted"));
3059 crStop(0);
3060 }
3061
32874aea 3062 {
3063 char *agentreq, *q, *ret;
2d466ffd 3064 void *vret;
32874aea 3065 int len, retlen;
3066 len = 1 + 4; /* message type, bit count */
51470298 3067 len += ssh1_bignum_length(s->key.exponent);
3068 len += ssh1_bignum_length(s->key.modulus);
3069 len += ssh1_bignum_length(s->challenge);
32874aea 3070 len += 16; /* session id */
3071 len += 4; /* response format */
3d88e64d 3072 agentreq = snewn(4 + len, char);
32874aea 3073 PUT_32BIT(agentreq, len);
3074 q = agentreq + 4;
3075 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3076 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3077 q += 4;
51470298 3078 q += ssh1_write_bignum(q, s->key.exponent);
3079 q += ssh1_write_bignum(q, s->key.modulus);
3080 q += ssh1_write_bignum(q, s->challenge);
3081 memcpy(q, s->session_id, 16);
32874aea 3082 q += 16;
3083 PUT_32BIT(q, 1); /* response format */
839f10db 3084 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3085 ssh_agent_callback, ssh)) {
3086 sfree(agentreq);
3087 do {
3088 crReturn(0);
ff3187f6 3089 if (pktin) {
839f10db 3090 bombout(("Unexpected data from server"
3091 " while waiting for agent"
3092 " response"));
3093 crStop(0);
3094 }
ff3187f6 3095 } while (pktin || inlen > 0);
839f10db 3096 vret = ssh->agent_response;
3097 retlen = ssh->agent_response_len;
3098 } else
3099 sfree(agentreq);
2d466ffd 3100 ret = vret;
32874aea 3101 if (ret) {
3102 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3103 logevent("Sending Pageant's response");
51470298 3104 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3105 PKT_DATA, ret + 5, 16,
3106 PKT_END);
3107 sfree(ret);
ff3187f6 3108 crWaitUntil(pktin);
3109 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3110 logevent
3111 ("Pageant's response accepted");
3112 if (flags & FLAG_VERBOSE) {
51470298 3113 c_write_str(ssh, "Authenticated using"
3114 " RSA key \"");
3115 c_write(ssh, s->commentp,
3116 s->commentlen);
3117 c_write_str(ssh, "\" from agent\r\n");
32874aea 3118 }
51470298 3119 s->authed = TRUE;
32874aea 3120 } else
3121 logevent
3122 ("Pageant's response not accepted");
3123 } else {
3124 logevent
3125 ("Pageant failed to answer challenge");
3126 sfree(ret);
3127 }
3128 } else {
3129 logevent("No reply received from Pageant");
3130 }
3131 }
51470298 3132 freebn(s->key.exponent);
3133 freebn(s->key.modulus);
3134 freebn(s->challenge);
3135 if (s->authed)
32874aea 3136 break;
3137 }
29b1d0b3 3138 sfree(s->response);
32874aea 3139 }
51470298 3140 if (s->authed)
32874aea 3141 break;
3142 }
9a30e26b 3143 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3144 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3145
86916870 3146 if (ssh->cfg.try_tis_auth &&
51470298 3147 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3148 !s->tis_auth_refused) {
3149 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3150 logevent("Requested TIS authentication");
51470298 3151 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3152 crWaitUntil(pktin);
3153 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3154 logevent("TIS authentication declined");
3155 if (flags & FLAG_INTERACTIVE)
51470298 3156 c_write_str(ssh, "TIS authentication refused.\r\n");
3157 s->tis_auth_refused = 1;
614a20a0 3158 continue;
32874aea 3159 } else {
0016d70b 3160 char *challenge;
3161 int challengelen;
3162
ff3187f6 3163 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3164 if (!challenge) {
3165 bombout(("TIS challenge packet was badly formed"));
3166 crStop(0);
3167 }
32874aea 3168 logevent("Received TIS challenge");
51470298 3169 if (challengelen > sizeof(s->prompt) - 1)
3170 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3171 memcpy(s->prompt, challenge, challengelen);
614a20a0 3172 /* Prompt heuristic comes from OpenSSH */
51470298 3173 strncpy(s->prompt + challengelen,
3174 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3175 "": "\r\nResponse: ",
51470298 3176 (sizeof s->prompt) - challengelen);
3177 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3178 }
3179 }
86916870 3180 if (ssh->cfg.try_tis_auth &&
51470298 3181 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3182 !s->ccard_auth_refused) {
3183 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3184 logevent("Requested CryptoCard authentication");
51470298 3185 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3186 crWaitUntil(pktin);
3187 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3188 logevent("CryptoCard authentication declined");
51470298 3189 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3190 s->ccard_auth_refused = 1;
614a20a0 3191 continue;
32874aea 3192 } else {
0016d70b 3193 char *challenge;
3194 int challengelen;
3195
ff3187f6 3196 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3197 if (!challenge) {
3198 bombout(("CryptoCard challenge packet was badly formed"));
3199 crStop(0);
3200 }
32874aea 3201 logevent("Received CryptoCard challenge");
51470298 3202 if (challengelen > sizeof(s->prompt) - 1)
3203 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3204 memcpy(s->prompt, challenge, challengelen);
51470298 3205 strncpy(s->prompt + challengelen,
3206 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3207 "" : "\r\nResponse: ",
51470298 3208 sizeof(s->prompt) - challengelen);
3209 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3210 }
3211 }
51470298 3212 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3213 sprintf(s->prompt, "%.90s@%.90s's password: ",
3214 s->username, ssh->savedhost);
32874aea 3215 }
51470298 3216 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3217 char *comment = NULL;
231ee168 3218 int type;
3219 char msgbuf[256];
32874aea 3220 if (flags & FLAG_VERBOSE)
51470298 3221 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3222 logeventf(ssh, "Trying public key \"%s\"",
3223 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3224 type = key_type(&ssh->cfg.keyfile);
231ee168 3225 if (type != SSH_KEYTYPE_SSH1) {
3226 sprintf(msgbuf, "Key is of wrong type (%s)",
3227 key_type_to_str(type));
3228 logevent(msgbuf);
51470298 3229 c_write_str(ssh, msgbuf);
3230 c_write_str(ssh, "\r\n");
3231 s->tried_publickey = 1;
231ee168 3232 continue;
3233 }
9a30e26b 3234 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3235 if (flags & FLAG_VERBOSE)
51470298 3236 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3237 goto tryauth;
3238 }
51470298 3239 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3240 sfree(comment);
3241 }
a52f067e 3242
614a20a0 3243 /*
3244 * Show password prompt, having first obtained it via a TIS
3245 * or CryptoCard exchange if we're doing TIS or CryptoCard
3246 * authentication.
3247 */
fa17a66e 3248 if (ssh_get_line) {
51470298 3249 if (!ssh_get_line(s->prompt, s->password,
3250 sizeof(s->password), TRUE)) {
32874aea 3251 /*
3252 * get_line failed to get a password (for example
3253 * because one was supplied on the command line
3254 * which has already failed to work). Terminate.
3255 */
51470298 3256 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3257 PKT_STR, "No more passwords available to try",
3258 PKT_END);
247308b5 3259 logevent("Unable to authenticate");
a8327734 3260 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3261 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3262 crStop(1);
32874aea 3263 }
fb09bf1c 3264 } else {
614a20a0 3265 /* Prompt may have come from server. We've munged it a bit, so
3266 * we know it to be zero-terminated at least once. */
51470298 3267 int ret; /* need not be saved over crReturn */
3268 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3269 s->pos = 0;
0405e71f 3270
51470298 3271 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3272 do {
ff3187f6 3273 crWaitUntil(!pktin);
51470298 3274 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3275 } while (ret == 0);
3276 if (ret < 0)
3277 cleanup_exit(0);
51470298 3278 c_write_str(ssh, "\r\n");
32874aea 3279 }
3280
3281 tryauth:
51470298 3282 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3283 /*
3284 * Try public key authentication with the specified
3285 * key file.
3286 */
51470298 3287 s->tried_publickey = 1;
3288
3289 {
222d54dc 3290 const char *error = NULL;
3291 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3292 &error);
51470298 3293 if (ret == 0) {
3294 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3295 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3296 c_write_str(ssh, " (");
3297 c_write_str(ssh, error);
3298 c_write_str(ssh, ").\r\n");
51470298 3299 continue; /* go and try password */
3300 }
3301 if (ret == -1) {
3302 c_write_str(ssh, "Wrong passphrase.\r\n");
3303 s->tried_publickey = 0;
3304 continue; /* try again */
3305 }
32874aea 3306 }
3307
3308 /*
3309 * Send a public key attempt.
3310 */
51470298 3311 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3312 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3313
ff3187f6 3314 crWaitUntil(pktin);
3315 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3316 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3317 continue; /* go and try password */
3318 }
ff3187f6 3319 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3320 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3321 crStop(0);
32874aea 3322 }
32874aea 3323
51470298 3324 {
3325 int i;
3326 unsigned char buffer[32];
3327 Bignum challenge, response;
3328
ff3187f6 3329 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3330 bombout(("Server's RSA challenge was badly formatted"));
3331 crStop(0);
3332 }
51470298 3333 response = rsadecrypt(challenge, &s->key);
3334 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3335
51470298 3336 for (i = 0; i < 32; i++) {
3337 buffer[i] = bignum_byte(response, 31 - i);
3338 }
3339
3340 MD5Init(&md5c);
3341 MD5Update(&md5c, buffer, 32);
3342 MD5Update(&md5c, s->session_id, 16);
3343 MD5Final(buffer, &md5c);
32874aea 3344
51470298 3345 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3346 PKT_DATA, buffer, 16, PKT_END);
3347
3348 freebn(challenge);
3349 freebn(response);
3350 }
32874aea 3351
ff3187f6 3352 crWaitUntil(pktin);
3353 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3354 if (flags & FLAG_VERBOSE)
51470298 3355 c_write_str(ssh, "Failed to authenticate with"
3356 " our public key.\r\n");
32874aea 3357 continue; /* go and try password */
ff3187f6 3358 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3359 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3360 crStop(0);
32874aea 3361 }
3362
3363 break; /* we're through! */
3364 } else {
51470298 3365 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3366 /*
3367 * Defence against traffic analysis: we send a
3368 * whole bunch of packets containing strings of
3369 * different lengths. One of these strings is the
3370 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3371 * The others are all random data in
3372 * SSH1_MSG_IGNORE packets. This way a passive
3373 * listener can't tell which is the password, and
3374 * hence can't deduce the password length.
3375 *
3376 * Anybody with a password length greater than 16
3377 * bytes is going to have enough entropy in their
3378 * password that a listener won't find it _that_
3379 * much help to know how long it is. So what we'll
3380 * do is:
3381 *
3382 * - if password length < 16, we send 15 packets
3383 * containing string lengths 1 through 15
3384 *
3385 * - otherwise, we let N be the nearest multiple
3386 * of 8 below the password length, and send 8
3387 * packets containing string lengths N through
3388 * N+7. This won't obscure the order of
3389 * magnitude of the password length, but it will
3390 * introduce a bit of extra uncertainty.
3391 *
3392 * A few servers (the old 1.2.18 through 1.2.22)
3393 * can't deal with SSH1_MSG_IGNORE. For these
3394 * servers, we need an alternative defence. We make
3395 * use of the fact that the password is interpreted
3396 * as a C string: so we can append a NUL, then some
3397 * random data.
bd358db1 3398 *
3399 * One server (a Cisco one) can deal with neither
3400 * SSH1_MSG_IGNORE _nor_ a padded password string.
3401 * For this server we are left with no defences
3402 * against password length sniffing.
32874aea 3403 */
51470298 3404 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3405 /*
3406 * The server can deal with SSH1_MSG_IGNORE, so
3407 * we can use the primary defence.
3408 */
32874aea 3409 int bottom, top, pwlen, i;
3410 char *randomstr;
3411
51470298 3412 pwlen = strlen(s->password);
32874aea 3413 if (pwlen < 16) {
3414 bottom = 0; /* zero length passwords are OK! :-) */
3415 top = 15;
3416 } else {
3417 bottom = pwlen & ~7;
3418 top = bottom + 7;
3419 }
3420
3421 assert(pwlen >= bottom && pwlen <= top);
3422
3d88e64d 3423 randomstr = snewn(top + 1, char);
32874aea 3424
3425 for (i = bottom; i <= top; i++) {
9a10ecf4 3426 if (i == pwlen) {
51470298 3427 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3428 PKTT_PASSWORD, PKT_STR, s->password,
3429 PKTT_OTHER, PKT_END);
3430 } else {
32874aea 3431 for (j = 0; j < i; j++) {
3432 do {
3433 randomstr[j] = random_byte();
3434 } while (randomstr[j] == '\0');
3435 }
3436 randomstr[i] = '\0';
51470298 3437 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3438 PKT_STR, randomstr, PKT_END);
3439 }
3440 }
bd358db1 3441 logevent("Sending password with camouflage packets");
51470298 3442 ssh_pkt_defersend(ssh);
679539d7 3443 sfree(randomstr);
bd358db1 3444 }
51470298 3445 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3446 /*
3447 * The server can't deal with SSH1_MSG_IGNORE
3448 * but can deal with padded passwords, so we
3449 * can use the secondary defence.
3450 */
bd358db1 3451 char string[64];
51470298 3452 char *ss;
bd358db1 3453 int len;
3454
51470298 3455 len = strlen(s->password);
bd358db1 3456 if (len < sizeof(string)) {
51470298 3457 ss = string;
3458 strcpy(string, s->password);
bd358db1 3459 len++; /* cover the zero byte */
3460 while (len < sizeof(string)) {
3461 string[len++] = (char) random_byte();
3462 }
3463 } else {
51470298 3464 ss = s->password;
bd358db1 3465 }
3466 logevent("Sending length-padded password");
9a10ecf4 3467 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3468 PKT_INT, len, PKT_DATA, ss, len,
3469 PKTT_OTHER, PKT_END);
bd358db1 3470 } else {
3471 /*
3472 * The server has _both_
3473 * BUG_CHOKES_ON_SSH1_IGNORE and
3474 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3475 * therefore nothing we can do.
3476 */
3477 int len;
51470298 3478 len = strlen(s->password);
bd358db1 3479 logevent("Sending unpadded password");
9a10ecf4 3480 send_packet(ssh, s->pwpkt_type,
3481 PKTT_PASSWORD, PKT_INT, len,
3482 PKT_DATA, s->password, len,
3483 PKTT_OTHER, PKT_END);
32874aea 3484 }
3485 } else {
9a10ecf4 3486 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3487 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3488 }
3489 }
c5e9c988 3490 logevent("Sent password");
51470298 3491 memset(s->password, 0, strlen(s->password));
ff3187f6 3492 crWaitUntil(pktin);
3493 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3494 if (flags & FLAG_VERBOSE)
51470298 3495 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3496 logevent("Authentication refused");
ff3187f6 3497 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3498 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3499 crStop(0);
374330e2 3500 }
3501 }
3502
c5e9c988 3503 logevent("Authentication successful");
3504
fb09bf1c 3505 crFinish(1);
3506}
3507
32874aea 3508void sshfwd_close(struct ssh_channel *c)
3509{
51470298 3510 Ssh ssh = c->ssh;
3511
36f94d1f 3512 if (ssh->state != SSH_STATE_SESSION) {
3513 assert(ssh->state == SSH_STATE_CLOSED);
3514 return;
3515 }
3516
80e48603 3517 if (c && !c->closes) {
4ed34d25 3518 /*
3519 * If the channel's remoteid is -1, we have sent
3520 * CHANNEL_OPEN for this channel, but it hasn't even been
3521 * acknowledged by the server. So we must set a close flag
3522 * on it now, and then when the server acks the channel
3523 * open, we can close it then.
3524 */
36cac739 3525 if (((int)c->remoteid) != -1) {
51470298 3526 if (ssh->version == 1) {
3527 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3528 PKT_END);
3529 } else {
ff3187f6 3530 struct Packet *pktout;
3531 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3532 ssh2_pkt_adduint32(pktout, c->remoteid);
3533 ssh2_pkt_send(ssh, pktout);
4ed34d25 3534 }
32874aea 3535 }
0357890f 3536 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3537 if (c->type == CHAN_X11) {
3538 c->u.x11.s = NULL;
d74d141c 3539 logevent("Forwarded X11 connection terminated");
4ed34d25 3540 } else if (c->type == CHAN_SOCKDATA ||
3541 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3542 c->u.pfd.s = NULL;
3543 logevent("Forwarded port closed");
32874aea 3544 }
3545 }
3546}
3547
5471d09a 3548int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3549{
51470298 3550 Ssh ssh = c->ssh;
3551
36f94d1f 3552 if (ssh->state != SSH_STATE_SESSION) {
3553 assert(ssh->state == SSH_STATE_CLOSED);
3554 return 0;
3555 }
3556
51470298 3557 if (ssh->version == 1) {
3558 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3559 PKT_INT, c->remoteid,
9a10ecf4 3560 PKTT_DATA,
3561 PKT_INT, len, PKT_DATA, buf, len,
3562 PKTT_OTHER, PKT_END);
5471d09a 3563 /*
3564 * In SSH1 we can return 0 here - implying that forwarded
3565 * connections are never individually throttled - because
3566 * the only circumstance that can cause throttling will be
3567 * the whole SSH connection backing up, in which case
3568 * _everything_ will be throttled as a whole.
3569 */
3570 return 0;
783415f8 3571 } else {
32874aea 3572 ssh2_add_channel_data(c, buf, len);
5471d09a 3573 return ssh2_try_send(c);
3574 }
3575}
3576
3577void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3578{
51470298 3579 Ssh ssh = c->ssh;
3580
36f94d1f 3581 if (ssh->state != SSH_STATE_SESSION) {
3582 assert(ssh->state == SSH_STATE_CLOSED);
3583 return;
3584 }
3585
51470298 3586 if (ssh->version == 1) {
5471d09a 3587 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3588 c->v.v1.throttling = 0;
51470298 3589 ssh1_throttle(ssh, -1);
5471d09a 3590 }
3591 } else {
3592 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3593 }
9c964e85 3594}
3595
06fadff5 3596static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3597{
3598 struct queued_handler *qh = ssh->qhead;
3599
3600 assert(qh != NULL);
3601
3602 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3603
3604 if (qh->msg1 > 0) {
3605 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3606 ssh->packet_dispatch[qh->msg1] = NULL;
3607 }
3608 if (qh->msg2 > 0) {
3609 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3610 ssh->packet_dispatch[qh->msg2] = NULL;
3611 }
3612
3613 if (qh->next) {
3614 ssh->qhead = qh->next;
3615
3616 if (ssh->qhead->msg1 > 0) {
3617 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3618 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3619 }
3620 if (ssh->qhead->msg2 > 0) {
3621 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3622 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3623 }
3624 } else {
3625 ssh->qhead = ssh->qtail = NULL;
3626 ssh->packet_dispatch[pktin->type] = NULL;
3627 }
3628
3629 qh->handler(ssh, pktin, qh->ctx);
3630
3631 sfree(qh);
3632}
3633
3634static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3635 chandler_fn_t handler, void *ctx)
3636{
3637 struct queued_handler *qh;
3638
3639 qh = snew(struct queued_handler);
3640 qh->msg1 = msg1;
3641 qh->msg2 = msg2;
3642 qh->handler = handler;
3643 qh->ctx = ctx;
3644 qh->next = NULL;
3645
3646 if (ssh->qtail == NULL) {
3647 ssh->qhead = qh;
3648
3649 if (qh->msg1 > 0) {
3650 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3651 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3652 }
3653 if (qh->msg2 > 0) {
3654 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3655 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3656 }
3657 } else {
3658 ssh->qtail->next = qh;
3659 }
3660 ssh->qtail = qh;
3661}
3662
3663static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3664{
3665 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3666
3667 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3668 SSH2_MSG_REQUEST_SUCCESS)) {
3669 logeventf(ssh, "Remote port forwarding from %s enabled",
3670 pf->sportdesc);
3671 } else {
3672 logeventf(ssh, "Remote port forwarding from %s refused",
3673 pf->sportdesc);
3674
3675 rpf = del234(ssh->rportfwds, pf);
3676 assert(rpf == pf);
fda2feb1 3677 free_rportfwd(pf);
06fadff5 3678 }
3679}
3680
3681static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3682{
84328ddb 3683 const char *portfwd_strptr = cfg->portfwd;
3684 struct ssh_portfwd *epf;
3685 int i;
06fadff5 3686
fda2feb1 3687 if (!ssh->portfwds) {
3688 ssh->portfwds = newtree234(ssh_portcmp);
3689 } else {
3690 /*
3691 * Go through the existing port forwardings and tag them
84328ddb 3692 * with status==DESTROY. Any that we want to keep will be
3693 * re-enabled (status==KEEP) as we go through the
3694 * configuration and find out which bits are the same as
3695 * they were before.
fda2feb1 3696 */
3697 struct ssh_portfwd *epf;
3698 int i;
3699 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 3700 epf->status = DESTROY;
fda2feb1 3701 }
3702
06fadff5 3703 while (*portfwd_strptr) {
84328ddb 3704 char address_family, type;
3705 int sport,dport,sserv,dserv;
3706 char sports[256], dports[256], saddr[256], host[256];
3707 int n;
3708
05581745 3709 address_family = 'A';
3710 type = 'L';
84328ddb 3711 if (*portfwd_strptr == 'A' ||
3712 *portfwd_strptr == '4' ||
3713 *portfwd_strptr == '6')
3714 address_family = *portfwd_strptr++;
3715 if (*portfwd_strptr == 'L' ||
3716 *portfwd_strptr == 'R' ||
3717 *portfwd_strptr == 'D')
3718 type = *portfwd_strptr++;
05581745 3719
06fadff5 3720 saddr[0] = '\0';
05581745 3721
06fadff5 3722 n = 0;
3723 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3724 if (*portfwd_strptr == ':') {
3725 /*
3726 * We've seen a colon in the middle of the
3727 * source port number. This means that
3728 * everything we've seen until now is the
3729 * source _address_, so we'll move it into
3730 * saddr and start sports from the beginning
3731 * again.
3732 */
3733 portfwd_strptr++;
3734 sports[n] = '\0';
3735 if (ssh->version == 1 && type == 'R') {
3736 logeventf(ssh, "SSH1 cannot handle remote source address "
3737 "spec \"%s\"; ignoring", sports);
3738 } else
3739 strcpy(saddr, sports);
3740 n = 0;
3741 }
3742 if (n < 255) sports[n++] = *portfwd_strptr++;
3743 }
3744 sports[n] = 0;
3745 if (type != 'D') {
3746 if (*portfwd_strptr == '\t')
3747 portfwd_strptr++;
3748 n = 0;
3749 while (*portfwd_strptr && *portfwd_strptr != ':') {
3750 if (n < 255) host[n++] = *portfwd_strptr++;
3751 }
3752 host[n] = 0;
3753 if (*portfwd_strptr == ':')
3754 portfwd_strptr++;
3755 n = 0;
3756 while (*portfwd_strptr) {
3757 if (n < 255) dports[n++] = *portfwd_strptr++;
3758 }
3759 dports[n] = 0;
3760 portfwd_strptr++;
3761 dport = atoi(dports);
3762 dserv = 0;
3763 if (dport == 0) {
3764 dserv = 1;
3765 dport = net_service_lookup(dports);
3766 if (!dport) {
3767 logeventf(ssh, "Service lookup failed for destination"
3768 " port \"%s\"", dports);
3769 }
3770 }
3771 } else {
3772 while (*portfwd_strptr) portfwd_strptr++;
3773 dport = dserv = -1;
3774 portfwd_strptr++; /* eat the NUL and move to next one */
3775 }
3776 sport = atoi(sports);
3777 sserv = 0;
3778 if (sport == 0) {
3779 sserv = 1;
3780 sport = net_service_lookup(sports);
3781 if (!sport) {
3782 logeventf(ssh, "Service lookup failed for source"
3783 " port \"%s\"", sports);
3784 }
3785 }
3786 if (sport && dport) {
3787 /* Set up a description of the source port. */
fda2feb1 3788 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 3789
3790 pfrec = snew(struct ssh_portfwd);
3791 pfrec->type = type;
3792 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 3793 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 3794 pfrec->sport = sport;
84328ddb 3795 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 3796 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 3797 pfrec->dport = dport;
3798 pfrec->local = NULL;
3799 pfrec->remote = NULL;
05581745 3800 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3801 address_family == '6' ? ADDRTYPE_IPV6 :
3802 ADDRTYPE_UNSPEC);
fda2feb1 3803
3804 epfrec = add234(ssh->portfwds, pfrec);
3805 if (epfrec != pfrec) {
3806 /*
3807 * We already have a port forwarding with precisely
3808 * these parameters. Hence, no need to do anything;
84328ddb 3809 * simply tag the existing one as KEEP.
fda2feb1 3810 */
84328ddb 3811 epfrec->status = KEEP;
fda2feb1 3812 free_portfwd(pfrec);
84328ddb 3813 } else {
3814 pfrec->status = CREATE;
3815 }
3816 }
3817 }
3818
3819 /*
3820 * Now go through and destroy any port forwardings which were
3821 * not re-enabled.
3822 */
3823 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3824 if (epf->status == DESTROY) {
3825 char *message;
3826
3827 message = dupprintf("%s port forwarding from %s%s%d",
3828 epf->type == 'L' ? "local" :
3829 epf->type == 'R' ? "remote" : "dynamic",
3830 epf->saddr ? epf->saddr : "",
3831 epf->saddr ? ":" : "",
3832 epf->sport);
3833
3834 if (epf->type != 'D') {
3835 char *msg2 = dupprintf("%s to %s:%d", message,
3836 epf->daddr, epf->dport);
3837 sfree(message);
3838 message = msg2;
3839 }
3840
3841 logeventf(ssh, "Cancelling %s", message);
3842 sfree(message);
3843
3844 if (epf->remote) {
3845 struct ssh_rportfwd *rpf = epf->remote;
3846 struct Packet *pktout;
3847
3848 /*
3849 * Cancel the port forwarding at the server
3850 * end.
3851 */
3852 if (ssh->version == 1) {
3853 /*
3854 * We cannot cancel listening ports on the
3855 * server side in SSH1! There's no message
3856 * to support it. Instead, we simply remove
3857 * the rportfwd record from the local end
3858 * so that any connections the server tries
3859 * to make on it are rejected.
3860 */
3861 } else {
3862 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3863 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3864 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3865 if (epf->saddr) {
3866 ssh2_pkt_addstring(pktout, epf->saddr);
3867 } else if (ssh->cfg.rport_acceptall) {
3868 ssh2_pkt_addstring(pktout, "0.0.0.0");
3869 } else {
3870 ssh2_pkt_addstring(pktout, "127.0.0.1");
3871 }
3872 ssh2_pkt_adduint32(pktout, epf->sport);
3873 ssh2_pkt_send(ssh, pktout);
3874 }
3875
3876 del234(ssh->rportfwds, rpf);
3877 free_rportfwd(rpf);
3878 } else if (epf->local) {
3879 pfd_terminate(epf->local);
3880 }
3881
3882 delpos234(ssh->portfwds, i);
3883 free_portfwd(epf);
3884 i--; /* so we don't skip one in the list */
3885 }
3886
3887 /*
3888 * And finally, set up any new port forwardings (status==CREATE).
3889 */
3890 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3891 if (epf->status == CREATE) {
3892 char *sportdesc, *dportdesc;
3fe92132 3893 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 3894 epf->saddr ? epf->saddr : "",
3895 epf->saddr ? ":" : "",
3fe92132 3896 epf->sserv ? epf->sserv : "",
3897 epf->sserv ? "(" : "",
3898 epf->sport,
3899 epf->sserv ? ")" : "");
84328ddb 3900 if (epf->type == 'D') {
3901 dportdesc = NULL;
3902 } else {
3fe92132 3903 dportdesc = dupprintf("%s:%s%s%d%s",
3904 epf->daddr,
3905 epf->dserv ? epf->dserv : "",
3906 epf->dserv ? "(" : "",
3907 epf->dport,
3908 epf->dserv ? ")" : "");
84328ddb 3909 }
05581745 3910
84328ddb 3911 if (epf->type == 'L') {
3912 const char *err = pfd_addforward(epf->daddr, epf->dport,
3913 epf->saddr, epf->sport,
3914 ssh, &ssh->cfg,
3915 &epf->local,
3916 epf->addressfamily);
3917
3918 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3919 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3920 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3921 sportdesc, dportdesc,
3922 err ? " failed: " : "", err ? err : "");
3923 } else if (epf->type == 'D') {
06fadff5 3924 const char *err = pfd_addforward(NULL, -1,
84328ddb 3925 epf->saddr, epf->sport,
3926 ssh, &ssh->cfg,
3927 &epf->local,
3928 epf->addressfamily);
3929
3930 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3931 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3932 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3933 sportdesc,
3934 err ? " failed: " : "", err ? err : "");
06fadff5 3935 } else {
3936 struct ssh_rportfwd *pf;
3937
3938 /*
3939 * Ensure the remote port forwardings tree exists.
3940 */
3941 if (!ssh->rportfwds) {
3942 if (ssh->version == 1)
3943 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3944 else
3945 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3946 }
3947
3948 pf = snew(struct ssh_rportfwd);
84328ddb 3949 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
3950 pf->dhost[lenof(pf->dhost)-1] = '\0';
3951 pf->dport = epf->dport;
3952 pf->sport = epf->sport;
06fadff5 3953 if (add234(ssh->rportfwds, pf) != pf) {
3954 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 3955 epf->daddr, epf->dport);
06fadff5 3956 sfree(pf);
3957 } else {
3958 logeventf(ssh, "Requesting remote port %s"
84328ddb 3959 " forward to %s", sportdesc, dportdesc);
06fadff5 3960
3961 pf->sportdesc = sportdesc;
3962 sportdesc = NULL;
84328ddb 3963 epf->remote = pf;
3964 pf->pfrec = epf;
06fadff5 3965
3966 if (ssh->version == 1) {
3967 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 3968 PKT_INT, epf->sport,
3969 PKT_STR, epf->daddr,
3970 PKT_INT, epf->dport,
06fadff5 3971 PKT_END);
3972 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
3973 SSH1_SMSG_FAILURE,
3974 ssh_rportfwd_succfail, pf);
3975 } else {
3976 struct Packet *pktout;
3977 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3978 ssh2_pkt_addstring(pktout, "tcpip-forward");
3979 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 3980 if (epf->saddr) {
3981 ssh2_pkt_addstring(pktout, epf->saddr);
06fadff5 3982 } else if (ssh->cfg.rport_acceptall) {
3983 ssh2_pkt_addstring(pktout, "0.0.0.0");
3984 } else {
3985 ssh2_pkt_addstring(pktout, "127.0.0.1");
3986 }
84328ddb 3987 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 3988 ssh2_pkt_send(ssh, pktout);
3989
3990 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
3991 SSH2_MSG_REQUEST_FAILURE,
3992 ssh_rportfwd_succfail, pf);
3993 }
3994 }
3995 }
3996 sfree(sportdesc);
84328ddb 3997 sfree(dportdesc);
06fadff5 3998 }
06fadff5 3999}
4000
51df0ab5 4001static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4002{
4003 char *string;
4004 int stringlen, bufsize;
4005
4006 ssh_pkt_getstring(pktin, &string, &stringlen);
4007 if (string == NULL) {
4008 bombout(("Incoming terminal data packet was badly formed"));
4009 return;
4010 }
4011
4012 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4013 string, stringlen);
4014 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4015 ssh->v1_stdout_throttling = 1;
4016 ssh1_throttle(ssh, +1);
4017 }
4018}
4019
4020static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4021{
4022 /* Remote side is trying to open a channel to talk to our
4023 * X-Server. Give them back a local channel number. */
4024 struct ssh_channel *c;
4025 int remoteid = ssh_pkt_getuint32(pktin);
4026
4027 logevent("Received X11 connect request");
4028 /* Refuse if X11 forwarding is disabled. */
4029 if (!ssh->X11_fwd_enabled) {
4030 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4031 PKT_INT, remoteid, PKT_END);
4032 logevent("Rejected X11 connect request");
4033 } else {
4034 c = snew(struct ssh_channel);
4035 c->ssh = ssh;
4036
4037 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4038 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4039 logevent("Opening X11 forward connection failed");
4040 sfree(c);
4041 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4042 PKT_INT, remoteid, PKT_END);
4043 } else {
4044 logevent
4045 ("Opening X11 forward connection succeeded");
4046 c->remoteid = remoteid;
4047 c->localid = alloc_channel_id(ssh);
4048 c->closes = 0;
4049 c->v.v1.throttling = 0;
4050 c->type = CHAN_X11; /* identify channel type */
4051 add234(ssh->channels, c);
4052 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4053 PKT_INT, c->remoteid, PKT_INT,
4054 c->localid, PKT_END);
4055 logevent("Opened X11 forward channel");
4056 }
4057 }
4058}
4059
4060static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4061{
4062 /* Remote side is trying to open a channel to talk to our
4063 * agent. Give them back a local channel number. */
4064 struct ssh_channel *c;
4065 int remoteid = ssh_pkt_getuint32(pktin);
4066
4067 /* Refuse if agent forwarding is disabled. */
4068 if (!ssh->agentfwd_enabled) {
4069 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4070 PKT_INT, remoteid, PKT_END);
4071 } else {
4072 c = snew(struct ssh_channel);
4073 c->ssh = ssh;
4074 c->remoteid = remoteid;
4075 c->localid = alloc_channel_id(ssh);
4076 c->closes = 0;
4077 c->v.v1.throttling = 0;
4078 c->type = CHAN_AGENT; /* identify channel type */
4079 c->u.a.lensofar = 0;
4080 add234(ssh->channels, c);
4081 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4082 PKT_INT, c->remoteid, PKT_INT, c->localid,
4083 PKT_END);
4084 }
4085}
4086
4087static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4088{
4089 /* Remote side is trying to open a channel to talk to a
4090 * forwarded port. Give them back a local channel number. */
4091 struct ssh_channel *c;
05581745 4092 struct ssh_rportfwd pf, *pfp;
51df0ab5 4093 int remoteid;
4094 int hostsize, port;
4095 char *host, buf[1024];
4096 const char *e;
4097 c = snew(struct ssh_channel);
4098 c->ssh = ssh;
4099
4100 remoteid = ssh_pkt_getuint32(pktin);
4101 ssh_pkt_getstring(pktin, &host, &hostsize);
4102 port = ssh_pkt_getuint32(pktin);
4103
4104 if (hostsize >= lenof(pf.dhost))
4105 hostsize = lenof(pf.dhost)-1;
4106 memcpy(pf.dhost, host, hostsize);
4107 pf.dhost[hostsize] = '\0';
4108 pf.dport = port;
05581745 4109 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4110
05581745 4111 if (pfp == NULL) {
51df0ab5 4112 sprintf(buf, "Rejected remote port open request for %s:%d",
4113 pf.dhost, port);
4114 logevent(buf);
4115 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4116 PKT_INT, remoteid, PKT_END);
4117 } else {
4118 sprintf(buf, "Received remote port open request for %s:%d",
4119 pf.dhost, port);
4120 logevent(buf);
4121 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4122 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4123 if (e != NULL) {
4124 char buf[256];
4125 sprintf(buf, "Port open failed: %s", e);
4126 logevent(buf);
4127 sfree(c);
4128 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4129 PKT_INT, remoteid, PKT_END);
4130 } else {
4131 c->remoteid = remoteid;
4132 c->localid = alloc_channel_id(ssh);
4133 c->closes = 0;
4134 c->v.v1.throttling = 0;
4135 c->type = CHAN_SOCKDATA; /* identify channel type */
4136 add234(ssh->channels, c);
4137 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4138 PKT_INT, c->remoteid, PKT_INT,
4139 c->localid, PKT_END);
4140 logevent("Forwarded port opened successfully");
4141 }
4142 }
4143}
4144
4145static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4146{
4147 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4148 unsigned int localid = ssh_pkt_getuint32(pktin);
4149 struct ssh_channel *c;
4150
4151 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4152 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4153 c->remoteid = localid;
4154 c->type = CHAN_SOCKDATA;
4155 c->v.v1.throttling = 0;
4156 pfd_confirm(c->u.pfd.s);
4157 }
4158
4159 if (c && c->closes) {
4160 /*
4161 * We have a pending close on this channel,
4162 * which we decided on before the server acked
4163 * the channel open. So now we know the
4164 * remoteid, we can close it again.
4165 */
4166 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4167 PKT_INT, c->remoteid, PKT_END);
4168 }
4169}
4170
4171static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4172{
4173 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4174 struct ssh_channel *c;
4175
4176 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4177 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4178 logevent("Forwarded connection refused by server");
4179 pfd_close(c->u.pfd.s);
4180 del234(ssh->channels, c);
4181 sfree(c);
4182 }
4183}
4184
4185static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4186{
4187 /* Remote side closes a channel. */
4188 unsigned i = ssh_pkt_getuint32(pktin);
4189 struct ssh_channel *c;
4190 c = find234(ssh->channels, &i, ssh_channelfind);
4191 if (c && ((int)c->remoteid) != -1) {
4192 int closetype;
4193 closetype =
4194 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4195
4196 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4197 logevent("Forwarded X11 connection terminated");
4198 assert(c->u.x11.s != NULL);
4199 x11_close(c->u.x11.s);
4200 c->u.x11.s = NULL;
4201 }
4202 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4203 logevent("Forwarded port closed");
4204 assert(c->u.pfd.s != NULL);
4205 pfd_close(c->u.pfd.s);
4206 c->u.pfd.s = NULL;
4207 }
4208
4209 c->closes |= (closetype << 2); /* seen this message */
4210 if (!(c->closes & closetype)) {
4211 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4212 PKT_END);
4213 c->closes |= closetype; /* sent it too */
4214 }
4215
4216 if (c->closes == 15) {
4217 del234(ssh->channels, c);
4218 sfree(c);
4219 }
4220 } else {
4221 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4222 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4223 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4224 i));
4225 }
4226}
4227
4228static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4229{
4230 /* Data sent down one of our channels. */
4231 int i = ssh_pkt_getuint32(pktin);
4232 char *p;
aa63ab7e 4233 unsigned int len;
51df0ab5 4234 struct ssh_channel *c;
4235
4236 ssh_pkt_getstring(pktin, &p, &len);
4237
4238 c = find234(ssh->channels, &i, ssh_channelfind);
4239 if (c) {
4240 int bufsize = 0;
4241 switch (c->type) {
4242 case CHAN_X11:
4243 bufsize = x11_send(c->u.x11.s, p, len);
4244 break;
4245 case CHAN_SOCKDATA:
4246 bufsize = pfd_send(c->u.pfd.s, p, len);
4247 break;
4248 case CHAN_AGENT:
4249 /* Data for an agent message. Buffer it. */
4250 while (len > 0) {
4251 if (c->u.a.lensofar < 4) {
aa63ab7e 4252 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4253 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4254 l);
4255 p += l;
4256 len -= l;
4257 c->u.a.lensofar += l;
4258 }
4259 if (c->u.a.lensofar == 4) {
4260 c->u.a.totallen =
4261 4 + GET_32BIT(c->u.a.msglen);
4262 c->u.a.message = snewn(c->u.a.totallen,
4263 unsigned char);
4264 memcpy(c->u.a.message, c->u.a.msglen, 4);
4265 }
4266 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4267 unsigned int l =
51df0ab5 4268 min(c->u.a.totallen - c->u.a.lensofar,
4269 len);
4270 memcpy(c->u.a.message + c->u.a.lensofar, p,
4271 l);
4272 p += l;
4273 len -= l;
4274 c->u.a.lensofar += l;
4275 }
4276 if (c->u.a.lensofar == c->u.a.totallen) {
4277 void *reply;
4278 int replylen;
4279 if (agent_query(c->u.a.message,
4280 c->u.a.totallen,
4281 &reply, &replylen,
4282 ssh_agentf_callback, c))
4283 ssh_agentf_callback(c, reply, replylen);
4284 sfree(c->u.a.message);
4285 c->u.a.lensofar = 0;
4286 }
4287 }
4288 bufsize = 0; /* agent channels never back up */
4289 break;
4290 }
4291 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4292 c->v.v1.throttling = 1;
4293 ssh1_throttle(ssh, +1);
4294 }
4295 }
4296}
4297
4298static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4299{
4300 char buf[100];
4301 ssh->exitcode = ssh_pkt_getuint32(pktin);
4302 sprintf(buf, "Server sent command exit status %d",
4303 ssh->exitcode);
4304 logevent(buf);
4305 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4306 /*
4307 * In case `helpful' firewalls or proxies tack
4308 * extra human-readable text on the end of the
4309 * session which we might mistake for another
4310 * encrypted packet, we close the session once
4311 * we've sent EXIT_CONFIRMATION.
4312 */
4313 ssh_closing((Plug)ssh, NULL, 0, 0);
4314}
4315
b09eaa88 4316static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4317 struct Packet *pktin)
32874aea 4318{
b09eaa88 4319 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4320
51df0ab5 4321 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4322 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4323 ssh1_smsg_stdout_stderr_data;
4324
4325 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4326 ssh1_msg_channel_open_confirmation;
4327 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4328 ssh1_msg_channel_open_failure;
4329 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4330 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4331 ssh1_msg_channel_close;
4332 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4333 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4334
86916870 4335 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4336 logevent("Requesting agent forwarding");
51470298 4337 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4338 do {
4339 crReturnV;
ff3187f6 4340 } while (!pktin);
4341 if (pktin->type != SSH1_SMSG_SUCCESS
4342 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4343 bombout(("Protocol confusion"));
7ffdbc1a 4344 crStopV;
ff3187f6 4345 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4346 logevent("Agent forwarding refused");
4347 } else {
4348 logevent("Agent forwarding enabled");
51470298 4349 ssh->agentfwd_enabled = TRUE;
51df0ab5 4350 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4351 }
dacbd0e8 4352 }
4353
86916870 4354 if (ssh->cfg.x11_forward) {
32874aea 4355 char proto[20], data[64];
4356 logevent("Requesting X11 forwarding");
302121de 4357 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4358 data, sizeof(data), ssh->cfg.x11_auth);
4359 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 4360 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4361 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4362 PKT_STR, proto, PKT_STR, data,
86916870 4363 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4364 PKT_END);
32874aea 4365 } else {
51470298 4366 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4367 PKT_STR, proto, PKT_STR, data, PKT_END);
4368 }
4369 do {
4370 crReturnV;
ff3187f6 4371 } while (!pktin);
4372 if (pktin->type != SSH1_SMSG_SUCCESS
4373 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4374 bombout(("Protocol confusion"));
7ffdbc1a 4375 crStopV;
ff3187f6 4376 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4377 logevent("X11 forwarding refused");
4378 } else {
4379 logevent("X11 forwarding enabled");
51470298 4380 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4381 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4382 }
4383 }
4384
06fadff5 4385 ssh_setup_portfwd(ssh, &ssh->cfg);
4386 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4387
86916870 4388 if (!ssh->cfg.nopty) {
a5dd8467 4389 /* Unpick the terminal-speed string. */
4390 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4391 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4392 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4393 /* Send the pty request. */
51470298 4394 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4395 PKT_STR, ssh->cfg.termtype,
51470298 4396 PKT_INT, ssh->term_height,
4397 PKT_INT, ssh->term_width,
a5dd8467 4398 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4399 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4400 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4401 PKT_CHAR, 0, PKT_END);
51470298 4402 ssh->state = SSH_STATE_INTERMED;
32874aea 4403 do {
4404 crReturnV;
ff3187f6 4405 } while (!pktin);
4406 if (pktin->type != SSH1_SMSG_SUCCESS
4407 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4408 bombout(("Protocol confusion"));
7ffdbc1a 4409 crStopV;
ff3187f6 4410 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4411 c_write_str(ssh, "Server refused to allocate pty\r\n");
4412 ssh->editing = ssh->echoing = 1;
32874aea 4413 }
a5dd8467 4414 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4415 ssh->ospeed, ssh->ispeed);
0965bee0 4416 } else {
51470298 4417 ssh->editing = ssh->echoing = 1;
374330e2 4418 }
4419
86916870 4420 if (ssh->cfg.compression) {
51470298 4421 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4422 do {
4423 crReturnV;
ff3187f6 4424 } while (!pktin);
4425 if (pktin->type != SSH1_SMSG_SUCCESS
4426 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4427 bombout(("Protocol confusion"));
7ffdbc1a 4428 crStopV;
ff3187f6 4429 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4430 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4431 }
4ba9b64b 4432 logevent("Started compression");
51470298 4433 ssh->v1_compressing = TRUE;
5366aed8 4434 ssh->cs_comp_ctx = zlib_compress_init();
4435 logevent("Initialised zlib (RFC1950) compression");
4436 ssh->sc_comp_ctx = zlib_decompress_init();
4437 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4438 }
4439
fd5e5847 4440 /*
4441 * Start the shell or command.
4442 *
4443 * Special case: if the first-choice command is an SSH2
4444 * subsystem (hence not usable here) and the second choice
4445 * exists, we fall straight back to that.
4446 */
4447 {
86916870 4448 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 4449
86916870 4450 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4451 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4452 ssh->fallback_cmd = TRUE;
fd5e5847 4453 }
4454 if (*cmd)
51470298 4455 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4456 else
51470298 4457 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4458 logevent("Started session");
4459 }
374330e2 4460
51470298 4461 ssh->state = SSH_STATE_SESSION;
4462 if (ssh->size_needed)
4463 ssh_size(ssh, ssh->term_width, ssh->term_height);
4464 if (ssh->eof_needed)
4465 ssh_special(ssh, TS_EOF);
374330e2 4466
b9d7bcad 4467 if (ssh->ldisc)
4468 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4469 ssh->send_ok = 1;
4470 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4471 while (1) {
d74d141c 4472
51df0ab5 4473 /*
4474 * By this point, most incoming packets are already being
4475 * handled by the dispatch table, and we need only pay
4476 * attention to the unusual ones.
4477 */
0357890f 4478
51df0ab5 4479 crReturnV;
4480 if (pktin) {
4481 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4482 /* may be from EXEC_SHELL on some servers */
ff3187f6 4483 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4484 /* may be from EXEC_SHELL on some servers
374330e2 4485 * if no pty is available or in other odd cases. Ignore */
374330e2 4486 } else {
ff3187f6 4487 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4488 crStopV;
374330e2 4489 }
4490 } else {
8df7a775 4491 while (inlen > 0) {
4492 int len = min(inlen, 512);
9a10ecf4 4493 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4494 PKT_INT, len, PKT_DATA, in, len,
4495 PKTT_OTHER, PKT_END);
8df7a775 4496 in += len;
4497 inlen -= len;
4498 }
374330e2 4499 }
4500 }
4501
4502 crFinishV;
4503}
4504
4505/*
b09eaa88 4506 * Handle the top-level SSH2 protocol.
4507 */
4508static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4509{
4510 char *buf, *msg;
4511 int msglen;
4512
4513 ssh_pkt_getstring(pktin, &msg, &msglen);
4514 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4515 logevent(buf);
4516 sfree(buf);
4517}
4518
4519static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4520{
4521 /* log reason code in disconnect message */
4522 char *msg;
4523 int msglen;
4524
4525 ssh_pkt_getstring(pktin, &msg, &msglen);
4526 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4527}
4528
4529void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4530{
4531 /* Do nothing, because we're ignoring it! Duhh. */
4532}
4533
4534static void ssh1_protocol_setup(Ssh ssh)
4535{
4536 int i;
4537
4538 /*
4539 * Most messages are handled by the coroutines.
4540 */
4541 for (i = 0; i < 256; i++)
4542 ssh->packet_dispatch[i] = NULL;
4543
4544 /*
4545 * These special message types we install handlers for.
4546 */
4547 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4548 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4549 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4550}
4551
4552static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4553 struct Packet *pktin)
4554{
4555 if (ssh->state == SSH_STATE_CLOSED)
4556 return;
4557
4558 if (pktin && ssh->packet_dispatch[pktin->type]) {
4559 ssh->packet_dispatch[pktin->type](ssh, pktin);
4560 return;
4561 }
4562
4563 if (!ssh->protocol_initial_phase_done) {
4564 if (do_ssh1_login(ssh, in, inlen, pktin))
4565 ssh->protocol_initial_phase_done = TRUE;
4566 else
4567 return;
4568 }
4569
4570 do_ssh1_connection(ssh, in, inlen, pktin);
4571}
4572
4573/*
e5574168 4574 * Utility routine for decoding comma-separated strings in KEXINIT.
4575 */
32874aea 4576static int in_commasep_string(char *needle, char *haystack, int haylen)
4577{
57356d63 4578 int needlen;
4579 if (!needle || !haystack) /* protect against null pointers */
4580 return 0;
4581 needlen = strlen(needle);
e5574168 4582 while (1) {
32874aea 4583 /*
4584 * Is it at the start of the string?
4585 */
4586 if (haylen >= needlen && /* haystack is long enough */
4587 !memcmp(needle, haystack, needlen) && /* initial match */
4588 (haylen == needlen || haystack[needlen] == ',')
4589 /* either , or EOS follows */
4590 )
4591 return 1;
4592 /*
4593 * If not, search for the next comma and resume after that.
4594 * If no comma found, terminate.
4595 */
4596 while (haylen > 0 && *haystack != ',')
4597 haylen--, haystack++;
4598 if (haylen == 0)
4599 return 0;
4600 haylen--, haystack++; /* skip over comma itself */
e5574168 4601 }
4602}
4603
4604/*
d39f364a 4605 * SSH2 key creation method.
4606 */
d8baa528 4607static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4608 unsigned char *sessid, char chr,
4609 unsigned char *keyspace)
32874aea 4610{
d39f364a 4611 SHA_State s;
4612 /* First 20 bytes. */
4613 SHA_Init(&s);
51470298 4614 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4615 sha_mpint(&s, K);
d39f364a 4616 SHA_Bytes(&s, H, 20);
4617 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4618 SHA_Bytes(&s, sessid, 20);
d39f364a 4619 SHA_Final(&s, keyspace);
4620 /* Next 20 bytes. */
4621 SHA_Init(&s);
51470298 4622 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4623 sha_mpint(&s, K);
d39f364a 4624 SHA_Bytes(&s, H, 20);
4625 SHA_Bytes(&s, keyspace, 20);
32874aea 4626 SHA_Final(&s, keyspace + 20);
d39f364a 4627}
4628
4629/*
7cca0d81 4630 * Handle the SSH2 transport layer.
e5574168 4631 */
ff3187f6 4632static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4633 struct Packet *pktin)
e5574168 4634{
51470298 4635 struct do_ssh2_transport_state {
4636 int nbits, pbits, warn;
4637 Bignum p, g, e, f, K;
4638 int kex_init_value, kex_reply_value;
4639 const struct ssh_mac **maclist;
4640 int nmacs;
4641 const struct ssh2_cipher *cscipher_tobe;
4642 const struct ssh2_cipher *sccipher_tobe;
4643 const struct ssh_mac *csmac_tobe;
4644 const struct ssh_mac *scmac_tobe;
4645 const struct ssh_compress *cscomp_tobe;
4646 const struct ssh_compress *sccomp_tobe;
4647 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4648 int hostkeylen, siglen;
4649 void *hkey; /* actual host key */
4650 unsigned char exchange_hash[20];
83e7d008 4651 int n_preferred_kex;
4652 const struct ssh_kex *preferred_kex[KEX_MAX];
51470298 4653 int n_preferred_ciphers;
4654 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4655 const struct ssh_compress *preferred_comp;
e13bba36 4656 int got_session_id, activated_authconn;
ff3187f6 4657 struct Packet *pktout;
51470298 4658 };
4659 crState(do_ssh2_transport_state);
4660
4661 crBegin(ssh->do_ssh2_transport_crstate);
4662
4663 s->cscipher_tobe = s->sccipher_tobe = NULL;
4664 s->csmac_tobe = s->scmac_tobe = NULL;
4665 s->cscomp_tobe = s->sccomp_tobe = NULL;
4666
e13bba36 4667 s->got_session_id = s->activated_authconn = FALSE;
e5574168 4668
e13bba36 4669 /*
4670 * Be prepared to work around the buggy MAC problem.
4671 */
4672 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4673 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4674 else
4675 s->maclist = macs, s->nmacs = lenof(macs);
4676
4677 begin_key_exchange:
51470298 4678 {
e13bba36 4679 int i, j, commalist_started;
4680
51470298 4681 /*
83e7d008 4682 * Set up the preferred key exchange. (NULL => warn below here)
4683 */
4684 s->n_preferred_kex = 0;
4685 for (i = 0; i < KEX_MAX; i++) {
4686 switch (ssh->cfg.ssh_kexlist[i]) {
4687 case KEX_DHGEX:
4688 s->preferred_kex[s->n_preferred_kex++] =
4689 &ssh_diffiehellman_gex;
4690 break;
4691 case KEX_DHGROUP14:
4692 s->preferred_kex[s->n_preferred_kex++] =
4693 &ssh_diffiehellman_group14;
4694 break;
4695 case KEX_DHGROUP1:
4696 s->preferred_kex[s->n_preferred_kex++] =
4697 &ssh_diffiehellman_group1;
4698 break;
4699 case CIPHER_WARN:
4700 /* Flag for later. Don't bother if it's the last in
4701 * the list. */
4702 if (i < KEX_MAX - 1) {
4703 s->preferred_kex[s->n_preferred_kex++] = NULL;
4704 }
4705 break;
4706 }
4707 }
83e7d008 4708
83e7d008 4709 /*
51470298 4710 * Set up the preferred ciphers. (NULL => warn below here)
4711 */
4712 s->n_preferred_ciphers = 0;
4713 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4714 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4715 case CIPHER_BLOWFISH:
4716 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4717 break;
4718 case CIPHER_DES:
86916870 4719 if (ssh->cfg.ssh2_des_cbc) {
51470298 4720 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4721 }
4722 break;
4723 case CIPHER_3DES:
4724 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4725 break;
4726 case CIPHER_AES:
4727 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4728 break;
4729 case CIPHER_WARN:
4730 /* Flag for later. Don't bother if it's the last in
4731 * the list. */
4732 if (i < CIPHER_MAX - 1) {
4733 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4734 }
4735 break;
ca20bfcf 4736 }
ca20bfcf 4737 }
7591b9ff 4738
e13bba36 4739 /*
4740 * Set up preferred compression.
4741 */
4742 if (ssh->cfg.compression)
4743 s->preferred_comp = &ssh_zlib;
4744 else
4745 s->preferred_comp = &ssh_comp_none;
51470298 4746
4747 /*
590f6a5f 4748 * Enable queueing of outgoing auth- or connection-layer
4749 * packets while we are in the middle of a key exchange.
4750 */
4751 ssh->queueing = TRUE;
4752
4753 /*
9442dd57 4754 * Flag that KEX is in progress.
4755 */
4756 ssh->kex_in_progress = TRUE;
4757
4758 /*
51470298 4759 * Construct and send our key exchange packet.
4760 */
ff3187f6 4761 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4762 for (i = 0; i < 16; i++)
ff3187f6 4763 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4764 /* List key exchange algorithms. */
ff3187f6 4765 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4766 commalist_started = 0;
4767 for (i = 0; i < s->n_preferred_kex; i++) {
4768 const struct ssh_kex *k = s->preferred_kex[i];
4769 if (!k) continue; /* warning flag */
4770 if (commalist_started)
ff3187f6 4771 ssh2_pkt_addstring_str(s->pktout, ",");
83e7d008 4772 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4773 commalist_started = 1;
32874aea 4774 }
51470298 4775 /* List server host key algorithms. */
ff3187f6 4776 ssh2_pkt_addstring_start(s->pktout);
51470298 4777 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4778 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4779 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4780 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4781 }
51470298 4782 /* List client->server encryption algorithms. */
ff3187f6 4783 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4784 commalist_started = 0;
51470298 4785 for (i = 0; i < s->n_preferred_ciphers; i++) {
4786 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4787 if (!c) continue; /* warning flag */
4788 for (j = 0; j < c->nciphers; j++) {
83e7d008 4789 if (commalist_started)
ff3187f6 4790 ssh2_pkt_addstring_str(s->pktout, ",");
4791 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4792 commalist_started = 1;
51470298 4793 }
4794 }
4795 /* List server->client encryption algorithms. */
ff3187f6 4796 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4797 commalist_started = 0;
51470298 4798 for (i = 0; i < s->n_preferred_ciphers; i++) {
4799 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4800 if (!c) continue; /* warning flag */
4801 for (j = 0; j < c->nciphers; j++) {
83e7d008 4802 if (commalist_started)
ff3187f6 4803 ssh2_pkt_addstring_str(s->pktout, ",");
4804 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4805 commalist_started = 1;
51470298 4806 }
4807 }
4808 /* List client->server MAC algorithms. */
ff3187f6 4809 ssh2_pkt_addstring_start(s->pktout);
51470298 4810 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4811 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4812 if (i < s->nmacs - 1)
ff3187f6 4813 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4814 }
4815 /* List server->client MAC algorithms. */
ff3187f6 4816 ssh2_pkt_addstring_start(s->pktout);
51470298 4817 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4818 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4819 if (i < s->nmacs - 1)
ff3187f6 4820 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4821 }
4822 /* List client->server compression algorithms. */
ff3187f6 4823 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4824 assert(lenof(compressions) > 1);
ff3187f6 4825 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4826 for (i = 0; i < lenof(compressions); i++) {
4827 const struct ssh_compress *c = compressions[i];
4828 if (c != s->preferred_comp) {
ff3187f6 4829 ssh2_pkt_addstring_str(s->pktout, ",");
4830 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4831 }
51470298 4832 }
4833 /* List server->client compression algorithms. */
ff3187f6 4834 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4835 assert(lenof(compressions) > 1);
ff3187f6 4836 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4837 for (i = 0; i < lenof(compressions); i++) {
4838 const struct ssh_compress *c = compressions[i];
4839 if (c != s->preferred_comp) {
ff3187f6 4840 ssh2_pkt_addstring_str(s->pktout, ",");
4841 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4842 }
51470298 4843 }
4844 /* List client->server languages. Empty list. */
ff3187f6 4845 ssh2_pkt_addstring_start(s->pktout);
51470298 4846 /* List server->client languages. Empty list. */
ff3187f6 4847 ssh2_pkt_addstring_start(s->pktout);
51470298 4848 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4849 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4850 /* Reserved. */
ff3187f6 4851 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4852 }
0db56f73 4853
51470298 4854 ssh->exhash = ssh->exhashbase;
ff3187f6 4855 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4856
590f6a5f 4857 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4858
ff3187f6 4859 if (!pktin)
4860 crWaitUntil(pktin);
4861 if (pktin->length > 5)
4862 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4863
4864 /*
4865 * Now examine the other side's KEXINIT to see what we're up
4866 * to.
4867 */
51470298 4868 {
4869 char *str;
4870 int i, j, len;
4871
ff3187f6 4872 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4873 bombout(("expected key exchange packet from server"));
7ffdbc1a 4874 crStop(0);
32874aea 4875 }
51470298 4876 ssh->kex = NULL;
4877 ssh->hostkey = NULL;
4878 s->cscipher_tobe = NULL;
4879 s->sccipher_tobe = NULL;
4880 s->csmac_tobe = NULL;
4881 s->scmac_tobe = NULL;
4882 s->cscomp_tobe = NULL;
4883 s->sccomp_tobe = NULL;
ff3187f6 4884 pktin->savedpos += 16; /* skip garbage cookie */
4885 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
83e7d008 4886 s->warn = 0;
4887 for (i = 0; i < s->n_preferred_kex; i++) {
4888 const struct ssh_kex *k = s->preferred_kex[i];
4889 if (!k) {
4890 s->warn = 1;
4891 } else if (in_commasep_string(k->name, str, len)) {
4892 ssh->kex = k;
4893 }
4894 if (ssh->kex) {
bb348ab1 4895 if (s->warn) {
4896 sk_set_frozen(ssh->s, 1);
83e7d008 4897 askalg(ssh->frontend, "key-exchange algorithm",
4898 ssh->kex->name);
bb348ab1 4899 sk_set_frozen(ssh->s, 0);
4900 }
51470298 4901 break;
4902 }
32874aea 4903 }
83e7d008 4904 if (!ssh->kex) {
4905 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4906 str ? str : "(null)"));
4907 crStop(0);
4908 }
ff3187f6 4909 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4910 for (i = 0; i < lenof(hostkey_algs); i++) {
4911 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4912 ssh->hostkey = hostkey_algs[i];
4913 break;
4914 }
4915 }
ff3187f6 4916 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4917 s->warn = 0;
4918 for (i = 0; i < s->n_preferred_ciphers; i++) {
4919 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4920 if (!c) {
4921 s->warn = 1;
4922 } else {
4923 for (j = 0; j < c->nciphers; j++) {
4924 if (in_commasep_string(c->list[j]->name, str, len)) {
4925 s->cscipher_tobe = c->list[j];
4926 break;
4927 }
ca20bfcf 4928 }
32874aea 4929 }
51470298 4930 if (s->cscipher_tobe) {
bb348ab1 4931 if (s->warn) {
4932 sk_set_frozen(ssh->s, 1);
83e7d008 4933 askalg(ssh->frontend, "client-to-server cipher",
4934 s->cscipher_tobe->name);
bb348ab1 4935 sk_set_frozen(ssh->s, 0);
4936 }
51470298 4937 break;
4938 }
32874aea 4939 }
51470298 4940 if (!s->cscipher_tobe) {
6b5cf8b4 4941 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4942 str ? str : "(null)"));
7ffdbc1a 4943 crStop(0);
ca20bfcf 4944 }
0ef8f407 4945
ff3187f6 4946 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4947 s->warn = 0;
4948 for (i = 0; i < s->n_preferred_ciphers; i++) {
4949 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4950 if (!c) {
4951 s->warn = 1;
4952 } else {
4953 for (j = 0; j < c->nciphers; j++) {
4954 if (in_commasep_string(c->list[j]->name, str, len)) {
4955 s->sccipher_tobe = c->list[j];
4956 break;
4957 }
ca20bfcf 4958 }
32874aea 4959 }
51470298 4960 if (s->sccipher_tobe) {
bb348ab1 4961 if (s->warn) {
4962 sk_set_frozen(ssh->s, 1);
83e7d008 4963 askalg(ssh->frontend, "server-to-client cipher",
4964 s->sccipher_tobe->name);
bb348ab1 4965 sk_set_frozen(ssh->s, 0);
4966 }
51470298 4967 break;
4968 }
32874aea 4969 }
51470298 4970 if (!s->sccipher_tobe) {
6b5cf8b4 4971 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4972 str ? str : "(null)"));
7ffdbc1a 4973 crStop(0);
ca20bfcf 4974 }
0ef8f407 4975
ff3187f6 4976 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 4977 for (i = 0; i < s->nmacs; i++) {
4978 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4979 s->csmac_tobe = s->maclist[i];
4980 break;
4981 }
32874aea 4982 }
ff3187f6 4983 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 4984 for (i = 0; i < s->nmacs; i++) {
4985 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4986 s->scmac_tobe = s->maclist[i];
4987 break;
4988 }
32874aea 4989 }
ff3187f6 4990 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 4991 for (i = 0; i < lenof(compressions) + 1; i++) {
4992 const struct ssh_compress *c =
4993 i == 0 ? s->preferred_comp : compressions[i - 1];
4994 if (in_commasep_string(c->name, str, len)) {
4995 s->cscomp_tobe = c;
4996 break;
4997 }
32874aea 4998 }
ff3187f6 4999 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5000 for (i = 0; i < lenof(compressions) + 1; i++) {
5001 const struct ssh_compress *c =
5002 i == 0 ? s->preferred_comp : compressions[i - 1];
5003 if (in_commasep_string(c->name, str, len)) {
5004 s->sccomp_tobe = c;
5005 break;
5006 }
32874aea 5007 }
e5574168 5008 }
e5574168 5009
5010 /*
7bd5a860 5011 * Work out the number of bits of key we will need from the key
5012 * exchange. We start with the maximum key length of either
5013 * cipher...
5014 */
5015 {
32874aea 5016 int csbits, scbits;
7bd5a860 5017
51470298 5018 csbits = s->cscipher_tobe->keylen;
5019 scbits = s->sccipher_tobe->keylen;
5020 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 5021 }
5022 /* The keys only have 160-bit entropy, since they're based on
5023 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 5024 if (s->nbits > 160)
5025 s->nbits = 160;
7bd5a860 5026
5027 /*
a92dd380 5028 * If we're doing Diffie-Hellman group exchange, start by
5029 * requesting a group.
e5574168 5030 */
d1aaf71d 5031 if (!ssh->kex->pdata) {
32874aea 5032 logevent("Doing Diffie-Hellman group exchange");
51470298 5033 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 5034 /*
5035 * Work out how big a DH group we will need to allow that
5036 * much data.
7bd5a860 5037 */
51470298 5038 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 5039 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5040 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 5041 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 5042
ff3187f6 5043 crWaitUntil(pktin);
5044 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 5045 bombout(("expected key exchange group packet from server"));
7ffdbc1a 5046 crStop(0);
32874aea 5047 }
ff3187f6 5048 s->p = ssh2_pkt_getmp(pktin);
5049 s->g = ssh2_pkt_getmp(pktin);
5050 if (!s->p || !s->g) {
5051 bombout(("unable to read mp-ints from incoming group packet"));
5052 crStop(0);
5053 }
d1aaf71d 5054 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5055 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5056 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5057 } else {
d1aaf71d 5058 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5059 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5060 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5061 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5062 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5063 ssh->kex->groupname);
8d5de777 5064 }
e5574168 5065
a92dd380 5066 logevent("Doing Diffie-Hellman key exchange");
e5574168 5067 /*
a92dd380 5068 * Now generate and send e for Diffie-Hellman.
e5574168 5069 */
27cd7fc2 5070 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5071 s->pktout = ssh2_pkt_init(s->kex_init_value);
5072 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5073 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5074
ff3187f6 5075 crWaitUntil(pktin);
5076 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5077 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5078 crStop(0);
7cca0d81 5079 }
ff3187f6 5080 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5081 s->f = ssh2_pkt_getmp(pktin);
5082 if (!s->f) {
5083 bombout(("unable to parse key exchange reply packet"));
5084 crStop(0);
5085 }
5086 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5087
27cd7fc2 5088 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5089
51470298 5090 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5091 if (ssh->kex == &ssh_diffiehellman_gex) {
5092 sha_uint32(&ssh->exhash, s->pbits);
5093 sha_mpint(&ssh->exhash, s->p);
5094 sha_mpint(&ssh->exhash, s->g);
a92dd380 5095 }
51470298 5096 sha_mpint(&ssh->exhash, s->e);
5097 sha_mpint(&ssh->exhash, s->f);
5098 sha_mpint(&ssh->exhash, s->K);
5099 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 5100
27cd7fc2 5101 dh_cleanup(ssh->kex_ctx);
fabd1805 5102 ssh->kex_ctx = NULL;
3709bfe9 5103
7cca0d81 5104#if 0
765c4200 5105 debug(("Exchange hash is:\n"));
51470298 5106 dmemdump(s->exchange_hash, 20);
7cca0d81 5107#endif
5108
51470298 5109 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5110 if (!s->hkey ||
5111 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 5112 (char *)s->exchange_hash, 20)) {
6b5cf8b4 5113 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5114 crStop(0);
8d5de777 5115 }
e5574168 5116
5117 /*
7cca0d81 5118 * Authenticate remote host: verify host key. (We've already
5119 * checked the signature of the exchange hash.)
e5574168 5120 */
51470298 5121 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5122 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
bb348ab1 5123 sk_set_frozen(ssh->s, 1);
a8327734 5124 verify_ssh_host_key(ssh->frontend,
5125 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 5126 s->keystr, s->fingerprint);
bb348ab1 5127 sk_set_frozen(ssh->s, 0);
e13bba36 5128 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5129 logevent("Host key fingerprint is:");
51470298 5130 logevent(s->fingerprint);
5e0d7cb8 5131 }
51470298 5132 sfree(s->fingerprint);
5133 sfree(s->keystr);
5134 ssh->hostkey->freekey(s->hkey);
d39f364a 5135
5136 /*
9442dd57 5137 * The exchange hash from the very first key exchange is also
5138 * the session id, used in session key construction and
5139 * authentication.
5140 */
e13bba36 5141 if (!s->got_session_id) {
9442dd57 5142 memcpy(ssh->v2_session_id, s->exchange_hash,
5143 sizeof(s->exchange_hash));
e13bba36 5144 s->got_session_id = TRUE;
5145 }
9442dd57 5146
5147 /*
7cca0d81 5148 * Send SSH2_MSG_NEWKEYS.
d39f364a 5149 */
ff3187f6 5150 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5151 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5152 ssh->outgoing_data_size = 0; /* start counting from here */
5153
5154 /*
5155 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5156 * client-to-server session keys.
9442dd57 5157 */
5158 if (ssh->cs_cipher_ctx)
5159 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5160 ssh->cscipher = s->cscipher_tobe;
5161 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5162
5163 if (ssh->cs_mac_ctx)
5164 ssh->csmac->free_context(ssh->cs_mac_ctx);
5165 ssh->csmac = s->csmac_tobe;
5166 ssh->cs_mac_ctx = ssh->csmac->make_context();
5167
5168 if (ssh->cs_comp_ctx)
5169 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5170 ssh->cscomp = s->cscomp_tobe;
5171 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5172
5173 /*
5174 * Set IVs on client-to-server keys. Here we use the exchange
5175 * hash from the _first_ key exchange.
5176 */
5177 {
5178 unsigned char keyspace[40];
5179 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5180 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5181 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5182 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5183 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5184 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5185 }
5186
5187 logeventf(ssh, "Initialised %.200s client->server encryption",
5188 ssh->cscipher->text_name);
5189 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5190 ssh->csmac->text_name);
5191 if (ssh->cscomp->text_name)
5192 logeventf(ssh, "Initialised %s compression",
5193 ssh->cscomp->text_name);
590f6a5f 5194
5195 /*
5196 * Now our end of the key exchange is complete, we can send all
5197 * our queued higher-layer packets.
5198 */
5199 ssh->queueing = FALSE;
5200 ssh2_pkt_queuesend(ssh);
d39f364a 5201
5202 /*
8406eaf9 5203 * Expect SSH2_MSG_NEWKEYS from server.
5204 */
ff3187f6 5205 crWaitUntil(pktin);
5206 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5207 bombout(("expected new-keys packet from server"));
7ffdbc1a 5208 crStop(0);
8406eaf9 5209 }
9442dd57 5210 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5211
5212 /*
9442dd57 5213 * We've seen server NEWKEYS, so create and initialise
5214 * server-to-client session keys.
d39f364a 5215 */
371e569c 5216 if (ssh->sc_cipher_ctx)
5217 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5218 ssh->sccipher = s->sccipher_tobe;
371e569c 5219 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5220
e0e1a00d 5221 if (ssh->sc_mac_ctx)
5222 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5223 ssh->scmac = s->scmac_tobe;
e0e1a00d 5224 ssh->sc_mac_ctx = ssh->scmac->make_context();
5225
5366aed8 5226 if (ssh->sc_comp_ctx)
5227 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5228 ssh->sccomp = s->sccomp_tobe;
5366aed8 5229 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5230
d39f364a 5231 /*
9442dd57 5232 * Set IVs on server-to-client keys. Here we use the exchange
5233 * hash from the _first_ key exchange.
d39f364a 5234 */
51470298 5235 {
5236 unsigned char keyspace[40];
51470298 5237 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 5238 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 5239 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 5240 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 5241 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 5242 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5243 }
57356d63 5244 logeventf(ssh, "Initialised %.200s server->client encryption",
5245 ssh->sccipher->text_name);
6c135243 5246 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5247 ssh->scmac->text_name);
57356d63 5248 if (ssh->sccomp->text_name)
5249 logeventf(ssh, "Initialised %s decompression",
5250 ssh->sccomp->text_name);
9442dd57 5251
5252 /*
5253 * Free key exchange data.
5254 */
679539d7 5255 freebn(s->f);
679539d7 5256 freebn(s->K);
b3949e7e 5257 if (ssh->kex == &ssh_diffiehellman_gex) {
5258 freebn(s->g);
5259 freebn(s->p);
5260 }
d39f364a 5261
033b4cef 5262 /*
e13bba36 5263 * Key exchange is over. Loop straight back round if we have a
5264 * deferred rekey reason.
5265 */
5266 if (ssh->deferred_rekey_reason) {
5267 logevent(ssh->deferred_rekey_reason);
5268 pktin = NULL;
5269 ssh->deferred_rekey_reason = NULL;
5270 goto begin_key_exchange;
5271 }
5272
5273 /*
5274 * Otherwise, schedule a timer for our next rekey.
9442dd57 5275 */
5276 ssh->kex_in_progress = FALSE;
e6c1536e 5277 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5278 if (ssh->cfg.ssh_rekey_time != 0)
5279 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5280 ssh2_timer, ssh);
e13bba36 5281
9442dd57 5282 /*
0db56f73 5283 * If this is the first key exchange phase, we must pass the
5284 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5285 * wants to see it but because it will need time to initialise
5286 * itself before it sees an actual packet. In subsequent key
5287 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5288 * it would only confuse the layer above.
5289 */
e13bba36 5290 if (s->activated_authconn) {
b09eaa88 5291 crReturn(1);
0db56f73 5292 }
e13bba36 5293 s->activated_authconn = TRUE;
0db56f73 5294
5295 /*
7cca0d81 5296 * Now we're encrypting. Begin returning 1 to the protocol main
5297 * function so that other things can run on top of the
5298 * transport. If we ever see a KEXINIT, we must go back to the
5299 * start.
9442dd57 5300 *
5301 * We _also_ go back to the start if we see pktin==NULL and
5302 * inlen==-1, because this is a special signal meaning
5303 * `initiate client-driven rekey', and `in' contains a message
5304 * giving the reason for the rekey.
033b4cef 5305 */
9442dd57 5306 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5307 (!pktin && inlen == -1))) {
32874aea 5308 crReturn(1);
e96adf72 5309 }
9442dd57 5310 if (pktin) {
5311 logevent("Server initiated key re-exchange");
5312 } else {
5313 logevent((char *)in);
5314 }
7cca0d81 5315 goto begin_key_exchange;
e5574168 5316
5317 crFinish(1);
5318}
5319
7cca0d81 5320/*
783415f8 5321 * Add data to an SSH2 channel output buffer.
5322 */
32874aea 5323static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5324 int len)
5325{
5471d09a 5326 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5327}
5328
5329/*
5330 * Attempt to send data on an SSH2 channel.
5331 */
5471d09a 5332static int ssh2_try_send(struct ssh_channel *c)
32874aea 5333{
51470298 5334 Ssh ssh = c->ssh;
ff3187f6 5335 struct Packet *pktout;
51470298 5336
5471d09a 5337 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5338 int len;
5339 void *data;
5340 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5341 if ((unsigned)len > c->v.v2.remwindow)
5342 len = c->v.v2.remwindow;
5343 if ((unsigned)len > c->v.v2.remmaxpkt)
5344 len = c->v.v2.remmaxpkt;
ff3187f6 5345 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5346 ssh2_pkt_adduint32(pktout, c->remoteid);
5347 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5348 ssh2_pkt_addstring_start(pktout);
5349 ssh2_pkt_addstring_data(pktout, data, len);
5350 end_log_omission(ssh, pktout);
5351 ssh2_pkt_send(ssh, pktout);
5471d09a 5352 bufchain_consume(&c->v.v2.outbuffer, len);
5353 c->v.v2.remwindow -= len;
5354 }
5355
5356 /*
5357 * After having sent as much data as we can, return the amount
5358 * still buffered.
5359 */
5360 return bufchain_size(&c->v.v2.outbuffer);
5361}
5362
5363/*
5364 * Potentially enlarge the window on an SSH2 channel.
5365 */
5366static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5367{
51470298 5368 Ssh ssh = c->ssh;
5369
6b69f42e 5370 /*
5371 * Never send WINDOW_ADJUST for a channel that the remote side
5372 * already thinks it's closed; there's no point, since it won't
5373 * be sending any more data anyway.
5374 */
5375 if (c->closes != 0)
5376 return;
5377
5471d09a 5378 if (newwin > c->v.v2.locwindow) {
ff3187f6 5379 struct Packet *pktout;
5380
5381 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5382 ssh2_pkt_adduint32(pktout, c->remoteid);
5383 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5384 ssh2_pkt_send(ssh, pktout);
5471d09a 5385 c->v.v2.locwindow = newwin;
783415f8 5386 }
5387}
5388
51df0ab5 5389static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5390{
5391 unsigned i = ssh_pkt_getuint32(pktin);
5392 struct ssh_channel *c;
5393 c = find234(ssh->channels, &i, ssh_channelfind);
5394 if (c && !c->closes)
5395 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5396}
5397
51df0ab5 5398static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5399{
5400 char *data;
aa63ab7e 5401 unsigned int length;
51df0ab5 5402 unsigned i = ssh_pkt_getuint32(pktin);
5403 struct ssh_channel *c;
5404 c = find234(ssh->channels, &i, ssh_channelfind);
5405 if (!c)
5406 return; /* nonexistent channel */
5407 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5408 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5409 return; /* extended but not stderr */
5410 ssh_pkt_getstring(pktin, &data, &length);
5411 if (data) {
5412 int bufsize = 0;
5413 c->v.v2.locwindow -= length;
5414 switch (c->type) {
5415 case CHAN_MAINSESSION:
5416 bufsize =
5417 from_backend(ssh->frontend, pktin->type ==
5418 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5419 data, length);
5420 break;
5421 case CHAN_X11:
5422 bufsize = x11_send(c->u.x11.s, data, length);
5423 break;
5424 case CHAN_SOCKDATA:
5425 bufsize = pfd_send(c->u.pfd.s, data, length);
5426 break;
5427 case CHAN_AGENT:
5428 while (length > 0) {
5429 if (c->u.a.lensofar < 4) {
aa63ab7e 5430 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5431 memcpy(c->u.a.msglen + c->u.a.lensofar,
5432 data, l);
5433 data += l;
5434 length -= l;
5435 c->u.a.lensofar += l;
5436 }
5437 if (c->u.a.lensofar == 4) {
5438 c->u.a.totallen =
5439 4 + GET_32BIT(c->u.a.msglen);
5440 c->u.a.message = snewn(c->u.a.totallen,
5441 unsigned char);
5442 memcpy(c->u.a.message, c->u.a.msglen, 4);
5443 }
5444 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5445 unsigned int l =
51df0ab5 5446 min(c->u.a.totallen - c->u.a.lensofar,
5447 length);
5448 memcpy(c->u.a.message + c->u.a.lensofar,
5449 data, l);
5450 data += l;
5451 length -= l;
5452 c->u.a.lensofar += l;
5453 }
5454 if (c->u.a.lensofar == c->u.a.totallen) {
5455 void *reply;
5456 int replylen;
5457 if (agent_query(c->u.a.message,
5458 c->u.a.totallen,
5459 &reply, &replylen,
5460 ssh_agentf_callback, c))
5461 ssh_agentf_callback(c, reply, replylen);
5462 sfree(c->u.a.message);
5463 c->u.a.lensofar = 0;
5464 }
5465 }
5466 bufsize = 0;
5467 break;
5468 }
5469 /*
5470 * If we are not buffering too much data,
5471 * enlarge the window again at the remote side.
5472 */
5473 if (bufsize < OUR_V2_WINSIZE)
5474 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5475 }
5476}
5477
5478static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5479{
5480 unsigned i = ssh_pkt_getuint32(pktin);
5481 struct ssh_channel *c;
5482
5483 c = find234(ssh->channels, &i, ssh_channelfind);
5484 if (!c)
5485 return; /* nonexistent channel */
5486
5487 if (c->type == CHAN_X11) {
5488 /*
5489 * Remote EOF on an X11 channel means we should
5490 * wrap up and close the channel ourselves.
5491 */
5492 x11_close(c->u.x11.s);
5493 sshfwd_close(c);
5494 } else if (c->type == CHAN_AGENT) {
5495 sshfwd_close(c);
5496 } else if (c->type == CHAN_SOCKDATA) {
5497 pfd_close(c->u.pfd.s);
5498 sshfwd_close(c);
5499 }
5500}
5501
5502static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5503{
5504 unsigned i = ssh_pkt_getuint32(pktin);
5505 struct ssh_channel *c;
5506 struct Packet *pktout;
5507
5508 c = find234(ssh->channels, &i, ssh_channelfind);
5509 if (!c || ((int)c->remoteid) == -1) {
5510 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5511 c ? "half-open" : "nonexistent", i));
5512 return;
5513 }
5514 /* Do pre-close processing on the channel. */
5515 switch (c->type) {
5516 case CHAN_MAINSESSION:
5517 ssh->mainchan = NULL;
5518 update_specials_menu(ssh->frontend);
5519 break;
5520 case CHAN_X11:
5521 if (c->u.x11.s != NULL)
5522 x11_close(c->u.x11.s);
5523 sshfwd_close(c);
5524 break;
5525 case CHAN_AGENT:
5526 sshfwd_close(c);
5527 break;
5528 case CHAN_SOCKDATA:
5529 if (c->u.pfd.s != NULL)
5530 pfd_close(c->u.pfd.s);
5531 sshfwd_close(c);
5532 break;
5533 }
5534 if (c->closes == 0) {
5535 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5536 ssh2_pkt_adduint32(pktout, c->remoteid);
5537 ssh2_pkt_send(ssh, pktout);
5538 }
5539 del234(ssh->channels, c);
5540 bufchain_clear(&c->v.v2.outbuffer);
5541 sfree(c);
5542
5543 /*
5544 * See if that was the last channel left open.
5545 * (This is only our termination condition if we're
5546 * not running in -N mode.)
5547 */
5548 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5549 logevent("All channels closed. Disconnecting");
5550#if 0
5551 /*
5552 * We used to send SSH_MSG_DISCONNECT here,
5553 * because I'd believed that _every_ conforming
5554 * SSH2 connection had to end with a disconnect
5555 * being sent by at least one side; apparently
5556 * I was wrong and it's perfectly OK to
5557 * unceremoniously slam the connection shut
5558 * when you're done, and indeed OpenSSH feels
5559 * this is more polite than sending a
5560 * DISCONNECT. So now we don't.
5561 */
5562 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5563 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5564 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5565 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5566 ssh2_pkt_send_noqueue(ssh, s->pktout);
5567#endif
5568 ssh_closing((Plug)ssh, NULL, 0, 0);
5569 }
5570}
5571
5572static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5573{
5574 unsigned i = ssh_pkt_getuint32(pktin);
5575 struct ssh_channel *c;
5576 struct Packet *pktout;
5577
5578 c = find234(ssh->channels, &i, ssh_channelfind);
5579 if (!c)
5580 return; /* nonexistent channel */
5581 if (c->type != CHAN_SOCKDATA_DORMANT)
5582 return; /* dunno why they're confirming this */
5583 c->remoteid = ssh_pkt_getuint32(pktin);
5584 c->type = CHAN_SOCKDATA;
5585 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5586 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5587 if (c->u.pfd.s)
5588 pfd_confirm(c->u.pfd.s);
5589 if (c->closes) {
5590 /*
5591 * We have a pending close on this channel,
5592 * which we decided on before the server acked
5593 * the channel open. So now we know the
5594 * remoteid, we can close it again.
5595 */
5596 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5597 ssh2_pkt_adduint32(pktout, c->remoteid);
5598 ssh2_pkt_send(ssh, pktout);
5599 }
5600}
5601
5602static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5603{
5604 static const char *const reasons[] = {
5605 "<unknown reason code>",
5606 "Administratively prohibited",
5607 "Connect failed",
5608 "Unknown channel type",
5609 "Resource shortage",
5610 };
5611 unsigned i = ssh_pkt_getuint32(pktin);
5612 unsigned reason_code;
5613 char *reason_string;
5614 int reason_length;
5615 char *message;
5616 struct ssh_channel *c;
5617 c = find234(ssh->channels, &i, ssh_channelfind);
5618 if (!c)
5619 return; /* nonexistent channel */
5620 if (c->type != CHAN_SOCKDATA_DORMANT)
5621 return; /* dunno why they're failing this */
5622
5623 reason_code = ssh_pkt_getuint32(pktin);
5624 if (reason_code >= lenof(reasons))
5625 reason_code = 0; /* ensure reasons[reason_code] in range */
5626 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5627 message = dupprintf("Forwarded connection refused by"
5628 " server: %s [%.*s]", reasons[reason_code],
5629 reason_length, reason_string);
5630 logevent(message);
5631 sfree(message);
5632
5633 pfd_close(c->u.pfd.s);
5634
5635 del234(ssh->channels, c);
5636 sfree(c);
5637}
5638
5639static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5640{
5641 unsigned localid;
5642 char *type;
5643 int typelen, want_reply;
5644 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5645 struct ssh_channel *c;
5646 struct Packet *pktout;
5647
5648 localid = ssh_pkt_getuint32(pktin);
5649 ssh_pkt_getstring(pktin, &type, &typelen);
5650 want_reply = ssh2_pkt_getbool(pktin);
5651
5652 /*
5653 * First, check that the channel exists. Otherwise,
5654 * we can instantly disconnect with a rude message.
5655 */
5656 c = find234(ssh->channels, &localid, ssh_channelfind);
5657 if (!c) {
5658 char buf[80];
5659 sprintf(buf, "Received channel request for nonexistent"
5660 " channel %d", localid);
5661 logevent(buf);
5662 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5663 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5664 ssh2_pkt_addstring(pktout, buf);
5665 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5666 ssh2_pkt_send_noqueue(ssh, pktout);
5667 connection_fatal(ssh->frontend, "%s", buf);
5668 ssh_closing((Plug)ssh, NULL, 0, 0);
5669 return;
5670 }
5671
5672 /*
5673 * Having got the channel number, we now look at
5674 * the request type string to see if it's something
5675 * we recognise.
5676 */
5677 if (c == ssh->mainchan) {
5678 /*
5679 * We recognise "exit-status" and "exit-signal" on
5680 * the primary channel.
5681 */
5682 if (typelen == 11 &&
5683 !memcmp(type, "exit-status", 11)) {
5684
5685 ssh->exitcode = ssh_pkt_getuint32(pktin);
5686 logeventf(ssh, "Server sent command exit status %d",
5687 ssh->exitcode);
5688 reply = SSH2_MSG_CHANNEL_SUCCESS;
5689
5690 } else if (typelen == 11 &&
5691 !memcmp(type, "exit-signal", 11)) {
5692
5693 int is_plausible = TRUE, is_int = FALSE;
5694 char *fmt_sig = "", *fmt_msg = "";
5695 char *msg;
5696 int msglen = 0, core = FALSE;
5697 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5698 * provide an `int' for the signal, despite its
5699 * having been a `string' in the drafts since at
5700 * least 2001. (Fixed in session.c 1.147.) Try to
5701 * infer which we can safely parse it as. */
5702 {
5703 unsigned char *p = pktin->body +
5704 pktin->savedpos;
5705 long len = pktin->length - pktin->savedpos;
5706 unsigned long num = GET_32BIT(p); /* what is it? */
5707 /* If it's 0, it hardly matters; assume string */
5708 if (num == 0) {
5709 is_int = FALSE;
5710 } else {
5711 int maybe_int = FALSE, maybe_str = FALSE;
5712#define CHECK_HYPOTHESIS(offset, result) \
5713 do { \
5714 long q = offset; \
5715 if (q >= 0 && q+4 <= len) { \
5716 q = q + 4 + GET_32BIT(p+q); \
5717 if (q >= 0 && q+4 <= len && \
5718 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5719 result = TRUE; \
5720 } \
5721 } while(0)
5722 CHECK_HYPOTHESIS(4+1, maybe_int);
5723 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5724#undef CHECK_HYPOTHESIS
5725 if (maybe_int && !maybe_str)
5726 is_int = TRUE;
5727 else if (!maybe_int && maybe_str)
5728 is_int = FALSE;
5729 else
5730 /* Crikey. Either or neither. Panic. */
5731 is_plausible = FALSE;
5732 }
5733 }
5734 if (is_plausible) {
5735 if (is_int) {
5736 /* Old non-standard OpenSSH. */
5737 int signum = ssh_pkt_getuint32(pktin);
5738 fmt_sig = dupprintf(" %d", signum);
5739 } else {
5740 /* As per the drafts. */
5741 char *sig;
5742 int siglen;
5743 ssh_pkt_getstring(pktin, &sig, &siglen);
5744 /* Signal name isn't supposed to be blank, but
5745 * let's cope gracefully if it is. */
5746 if (siglen) {
5747 fmt_sig = dupprintf(" \"%.*s\"",
5748 siglen, sig);
5749 }
5750 }
5751 core = ssh2_pkt_getbool(pktin);
5752 ssh_pkt_getstring(pktin, &msg, &msglen);
5753 if (msglen) {
5754 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5755 }
5756 /* ignore lang tag */
5757 } /* else don't attempt to parse */
5758 logeventf(ssh, "Server exited on signal%s%s%s",
5759 fmt_sig, core ? " (core dumped)" : "",
5760 fmt_msg);
5761 if (*fmt_sig) sfree(fmt_sig);
5762 if (*fmt_msg) sfree(fmt_msg);
5763 reply = SSH2_MSG_CHANNEL_SUCCESS;
5764
5765 }
5766 } else {
5767 /*
5768 * This is a channel request we don't know
5769 * about, so we now either ignore the request
5770 * or respond with CHANNEL_FAILURE, depending
5771 * on want_reply.
5772 */
5773 reply = SSH2_MSG_CHANNEL_FAILURE;
5774 }
5775 if (want_reply) {
5776 pktout = ssh2_pkt_init(reply);
5777 ssh2_pkt_adduint32(pktout, c->remoteid);
5778 ssh2_pkt_send(ssh, pktout);
5779 }
5780}
5781
5782static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5783{
5784 char *type;
5785 int typelen, want_reply;
5786 struct Packet *pktout;
5787
5788 ssh_pkt_getstring(pktin, &type, &typelen);
5789 want_reply = ssh2_pkt_getbool(pktin);
5790
5791 /*
5792 * We currently don't support any global requests
5793 * at all, so we either ignore the request or
5794 * respond with REQUEST_FAILURE, depending on
5795 * want_reply.
5796 */
5797 if (want_reply) {
5798 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5799 ssh2_pkt_send(ssh, pktout);
5800 }
5801}
5802
5803static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5804{
5805 char *type;
5806 int typelen;
5807 char *peeraddr;
5808 int peeraddrlen;
5809 int peerport;
5810 char *error = NULL;
5811 struct ssh_channel *c;
5812 unsigned remid, winsize, pktsize;
5813 struct Packet *pktout;
5814
5815 ssh_pkt_getstring(pktin, &type, &typelen);
5816 c = snew(struct ssh_channel);
5817 c->ssh = ssh;
5818
5819 remid = ssh_pkt_getuint32(pktin);
5820 winsize = ssh_pkt_getuint32(pktin);
5821 pktsize = ssh_pkt_getuint32(pktin);
5822
5823 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5824 char *addrstr;
5825
5826 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5827 addrstr = snewn(peeraddrlen+1, char);
5828 memcpy(addrstr, peeraddr, peeraddrlen);
5829 addrstr[peeraddrlen] = '\0';
5830 peerport = ssh_pkt_getuint32(pktin);
5831
5832 logeventf(ssh, "Received X11 connect request from %s:%d",
5833 addrstr, peerport);
5834
5835 if (!ssh->X11_fwd_enabled)
5836 error = "X11 forwarding is not enabled";
5837 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5838 ssh->x11auth, addrstr, peerport,
5839 &ssh->cfg) != NULL) {
5840 error = "Unable to open an X11 connection";
5841 } else {
5842 logevent("Opening X11 forward connection succeeded");
5843 c->type = CHAN_X11;
5844 }
5845
5846 sfree(addrstr);
5847 } else if (typelen == 15 &&
5848 !memcmp(type, "forwarded-tcpip", 15)) {
5849 struct ssh_rportfwd pf, *realpf;
5850 char *dummy;
5851 int dummylen;
5852 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5853 pf.sport = ssh_pkt_getuint32(pktin);
5854 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5855 peerport = ssh_pkt_getuint32(pktin);
5856 realpf = find234(ssh->rportfwds, &pf, NULL);
5857 logeventf(ssh, "Received remote port %d open request "
5858 "from %s:%d", pf.sport, peeraddr, peerport);
5859 if (realpf == NULL) {
5860 error = "Remote port is not recognised";
5861 } else {
5862 const char *e = pfd_newconnect(&c->u.pfd.s,
5863 realpf->dhost,
5864 realpf->dport, c,
05581745 5865 &ssh->cfg,
5866 realpf->pfrec->addressfamily);
51df0ab5 5867 logeventf(ssh, "Attempting to forward remote port to "
5868 "%s:%d", realpf->dhost, realpf->dport);
5869 if (e != NULL) {
5870 logeventf(ssh, "Port open failed: %s", e);
5871 error = "Port open failed";
5872 } else {
5873 logevent("Forwarded port opened successfully");
5874 c->type = CHAN_SOCKDATA;
5875 }
5876 }
5877 } else if (typelen == 22 &&
5878 !memcmp(type, "auth-agent@openssh.com", 3)) {
5879 if (!ssh->agentfwd_enabled)
5880 error = "Agent forwarding is not enabled";
5881 else {
5882 c->type = CHAN_AGENT; /* identify channel type */
5883 c->u.a.lensofar = 0;
5884 }
5885 } else {
5886 error = "Unsupported channel type requested";
5887 }
5888
5889 c->remoteid = remid;
5890 if (error) {
5891 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5892 ssh2_pkt_adduint32(pktout, c->remoteid);
5893 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5894 ssh2_pkt_addstring(pktout, error);
5895 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5896 ssh2_pkt_send(ssh, pktout);
5897 logeventf(ssh, "Rejected channel open: %s", error);
5898 sfree(c);
5899 } else {
5900 c->localid = alloc_channel_id(ssh);
5901 c->closes = 0;
5902 c->v.v2.locwindow = OUR_V2_WINSIZE;
5903 c->v.v2.remwindow = winsize;
5904 c->v.v2.remmaxpkt = pktsize;
5905 bufchain_init(&c->v.v2.outbuffer);
5906 add234(ssh->channels, c);
5907 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5908 ssh2_pkt_adduint32(pktout, c->remoteid);
5909 ssh2_pkt_adduint32(pktout, c->localid);
5910 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5911 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5912 ssh2_pkt_send(ssh, pktout);
5913 }
5914}
5915
783415f8 5916/*
7cca0d81 5917 * Handle the SSH2 userauth and connection layers.
5918 */
ff3187f6 5919static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5920 struct Packet *pktin)
7cca0d81 5921{
51470298 5922 struct do_ssh2_authconn_state {
5923 enum {
5924 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5925 AUTH_PASSWORD,
5926 AUTH_KEYBOARD_INTERACTIVE
5927 } method;
5928 enum {
5929 AUTH_TYPE_NONE,
5930 AUTH_TYPE_PUBLICKEY,
5931 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5932 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5933 AUTH_TYPE_PASSWORD,
5934 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5935 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5936 } type;
5937 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6ac3a551 5938 int tried_pubkey_config, tried_agent;
5939 int kbd_inter_running, kbd_inter_refused;
51470298 5940 int we_are_in;
5941 int num_prompts, curr_prompt, echo;
5942 char username[100];
5943 int got_username;
85fdbe25 5944 char pwprompt[512];
51470298 5945 char password[100];
5946 void *publickey_blob;
5947 int publickey_bloblen;
5948 unsigned char request[5], *response, *p;
5949 int responselen;
5950 int keyi, nkeys;
5951 int authed;
5952 char *pkblob, *alg, *commentp;
5953 int pklen, alglen, commentlen;
5954 int siglen, retlen, len;
5955 char *q, *agentreq, *ret;
5956 int try_send;
73feed4f 5957 int num_env, env_left, env_ok;
ff3187f6 5958 struct Packet *pktout;
51470298 5959 };
5960 crState(do_ssh2_authconn_state);
5961
5962 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 5963
7cca0d81 5964 /*
5965 * Request userauth protocol, and await a response to it.
5966 */
ff3187f6 5967 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5968 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5969 ssh2_pkt_send(ssh, s->pktout);
5970 crWaitUntilV(pktin);
5971 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 5972 bombout(("Server refused user authentication protocol"));
7ffdbc1a 5973 crStopV;
8d5de777 5974 }
7cca0d81 5975
5976 /*
1408a877 5977 * We repeat this whole loop, including the username prompt,
5978 * until we manage a successful authentication. If the user
51470298 5979 * types the wrong _password_, they can be sent back to the
5980 * beginning to try another username, if this is configured on.
5981 * (If they specify a username in the config, they are never
5982 * asked, even if they do give a wrong password.)
1408a877 5983 *
5984 * I think this best serves the needs of
5985 *
5986 * - the people who have no configuration, no keys, and just
5987 * want to try repeated (username,password) pairs until they
5988 * type both correctly
5989 *
5990 * - people who have keys and configuration but occasionally
5991 * need to fall back to passwords
5992 *
5993 * - people with a key held in Pageant, who might not have
5994 * logged in to a particular machine before; so they want to
5995 * type a username, and then _either_ their key will be
5996 * accepted, _or_ they will type a password. If they mistype
5997 * the username they will want to be able to get back and
5998 * retype it!
7cca0d81 5999 */
51470298 6000 s->username[0] = '\0';
6001 s->got_username = FALSE;
1408a877 6002 do {
1408a877 6003 /*
6004 * Get a username.
6005 */
86916870 6006 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 6007 /*
6008 * We got a username last time round this loop, and
6009 * with change_username turned off we don't try to get
6010 * it again.
6011 */
aa09f7d0 6012 } else if (!*ssh->cfg.username) {
c0a81592 6013 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 6014 if (!ssh_get_line("login as: ",
51470298 6015 s->username, sizeof(s->username), FALSE)) {
32874aea 6016 /*
6017 * get_line failed to get a username.
6018 * Terminate.
6019 */
6020 logevent("No username provided. Abandoning session.");
3bb2f322 6021 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6022 crStopV;
32874aea 6023 }
6024 } else {
51470298 6025 int ret; /* need not be saved across crReturn */
6026 c_write_str(ssh, "login as: ");
6027 ssh->send_ok = 1;
6028 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 6029 do {
ff3187f6 6030 crWaitUntilV(!pktin);
51470298 6031 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6032 } while (ret == 0);
6033 if (ret < 0)
6034 cleanup_exit(0);
4ca0c9d1 6035 c_write_str(ssh, "\r\n");
32874aea 6036 }
51470298 6037 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 6038 } else {
57356d63 6039 char *stuff;
86916870 6040 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 6041 s->username[sizeof(s->username)-1] = '\0';
65a22376 6042 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 6043 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 6044 c_write_str(ssh, stuff);
57356d63 6045 sfree(stuff);
7cca0d81 6046 }
6047 }
51470298 6048 s->got_username = TRUE;
7cca0d81 6049
65a22376 6050 /*
1408a877 6051 * Send an authentication request using method "none": (a)
6052 * just in case it succeeds, and (b) so that we know what
6053 * authentication methods we can usefully try next.
65a22376 6054 */
51470298 6055 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6056
ff3187f6 6057 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6058 ssh2_pkt_addstring(s->pktout, s->username);
6059 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6060 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6061 ssh2_pkt_send(ssh, s->pktout);
51470298 6062 s->type = AUTH_TYPE_NONE;
6063 s->gotit = FALSE;
6064 s->we_are_in = FALSE;
6065
6066 s->tried_pubkey_config = FALSE;
6067 s->tried_agent = FALSE;
51470298 6068 s->kbd_inter_running = FALSE;
6ac3a551 6069 s->kbd_inter_refused = FALSE;
86916870 6070 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 6071 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 6072 int keytype;
6c6d9ed9 6073 logeventf(ssh, "Reading private key file \"%.150s\"",
6074 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 6075 keytype = key_type(&ssh->cfg.keyfile);
51470298 6076 if (keytype == SSH_KEYTYPE_SSH2) {
6077 s->publickey_blob =
9a30e26b 6078 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 6079 &s->publickey_bloblen, NULL);
51470298 6080 } else {
57356d63 6081 char *msgbuf;
c2ad7d0d 6082 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 6083 key_type_to_str(keytype));
57356d63 6084 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 6085 " (%s)\r\n",
6086 filename_to_str(&ssh->cfg.keyfile),
57356d63 6087 key_type_to_str(keytype));
51470298 6088 c_write_str(ssh, msgbuf);
57356d63 6089 sfree(msgbuf);
51470298 6090 s->publickey_blob = NULL;
231ee168 6091 }
396778f1 6092 } else
51470298 6093 s->publickey_blob = NULL;
65a22376 6094
1408a877 6095 while (1) {
6096 /*
6097 * Wait for the result of the last authentication request.
6098 */
51470298 6099 if (!s->gotit)
ff3187f6 6100 crWaitUntilV(pktin);
6101 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 6102 char *banner;
6103 int size;
6104 /*
6105 * Don't show the banner if we're operating in
6106 * non-verbose non-interactive mode. (It's probably
6107 * a script, which means nobody will read the
6108 * banner _anyway_, and moreover the printing of
6109 * the banner will screw up processing on the
6110 * output of (say) plink.)
6111 */
6112 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 6113 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 6114 if (banner)
51470298 6115 c_write_untrusted(ssh, banner, size);
32874aea 6116 }
ff3187f6 6117 crWaitUntilV(pktin);
1408a877 6118 }
ff3187f6 6119 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6120 logevent("Access granted");
51470298 6121 s->we_are_in = TRUE;
1408a877 6122 break;
6123 }
65a22376 6124
51470298 6125 if (s->kbd_inter_running &&
ff3187f6 6126 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 6127 /*
45068b27 6128 * This is either a further set-of-prompts packet
6129 * in keyboard-interactive authentication, or it's
6130 * the same one and we came back here with `gotit'
6131 * set. In the former case, we must reset the
6132 * curr_prompt variable.
b3186d64 6133 */
51470298 6134 if (!s->gotit)
6135 s->curr_prompt = 0;
4c6e53e3 6136 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6137 /* FIXME: perhaps we should support this? */
6138 bombout(("PASSWD_CHANGEREQ not yet supported"));
6139 crStopV;
ff3187f6 6140 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 6141 bombout(("Strange packet received during authentication: type %d",
ff3187f6 6142 pktin->type));
7ffdbc1a 6143 crStopV;
65a22376 6144 }
6145
51470298 6146 s->gotit = FALSE;
65a22376 6147
1408a877 6148 /*
6149 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6150 * we can look at the string in it and know what we can
6151 * helpfully try next.
6152 */
ff3187f6 6153 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6154 char *methods;
6155 int methlen;
ff3187f6 6156 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 6157 s->kbd_inter_running = FALSE;
ff3187f6 6158 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6159 /*
6160 * We have received an unequivocal Access
6161 * Denied. This can translate to a variety of
6162 * messages:
6163 *
6164 * - if we'd just tried "none" authentication,
6165 * it's not worth printing anything at all
6166 *
6167 * - if we'd just tried a public key _offer_,
6168 * the message should be "Server refused our
6169 * key" (or no message at all if the key
6170 * came from Pageant)
6171 *
6172 * - if we'd just tried anything else, the
6173 * message really should be "Access denied".
6174 *
6175 * Additionally, if we'd just tried password
6176 * authentication, we should break out of this
6177 * whole loop so as to go back to the username
91f57d1f 6178 * prompt (iff we're configured to allow
6179 * username change attempts).
1408a877 6180 */
51470298 6181 if (s->type == AUTH_TYPE_NONE) {
1408a877 6182 /* do nothing */
51470298 6183 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6184 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6185 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6186 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6187 logevent("Server refused public key");
51470298 6188 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6189 /* server declined keyboard-interactive; ignore */
1408a877 6190 } else {
51470298 6191 c_write_str(ssh, "Access denied\r\n");
1408a877 6192 logevent("Access denied");
91f57d1f 6193 if (s->type == AUTH_TYPE_PASSWORD &&
6194 ssh->cfg.change_username) {
6c9dce7c 6195 /* XXX perhaps we should allow
6196 * keyboard-interactive to do this too? */
51470298 6197 s->we_are_in = FALSE;
1408a877 6198 break;
6199 }
6200 }
6201 } else {
51470298 6202 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6203 logevent("Further authentication required");
6204 }
65a22376 6205
51470298 6206 s->can_pubkey =
32874aea 6207 in_commasep_string("publickey", methods, methlen);
51470298 6208 s->can_passwd =
32874aea 6209 in_commasep_string("password", methods, methlen);
86916870 6210 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6211 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6212 }
65a22376 6213
51470298 6214 s->method = 0;
6215 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 6216 s->need_pw = FALSE;
65a22376 6217
0405e71f 6218 /*
6219 * Most password/passphrase prompts will be
6220 * non-echoing, so we set this to 0 by default.
6221 * Exception is that some keyboard-interactive prompts
6222 * can be echoing, in which case we'll set this to 1.
6223 */
51470298 6224 s->echo = 0;
0405e71f 6225
51470298 6226 if (!s->method && s->can_pubkey &&
6227 agent_exists() && !s->tried_agent) {
1983e559 6228 /*
6229 * Attempt public-key authentication using Pageant.
6230 */
1983e559 6231 void *r;
51470298 6232 s->authed = FALSE;
1983e559 6233
51470298 6234 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6235 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6236
51470298 6237 s->tried_agent = TRUE;
1983e559 6238
6239 logevent("Pageant is running. Requesting keys.");
6240
6241 /* Request the keys held by the agent. */
51470298 6242 PUT_32BIT(s->request, 1);
6243 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 6244 if (!agent_query(s->request, 5, &r, &s->responselen,
6245 ssh_agent_callback, ssh)) {
6246 do {
6247 crReturnV;
ff3187f6 6248 if (pktin) {
839f10db 6249 bombout(("Unexpected data from server while"
6250 " waiting for agent response"));
6251 crStopV;
6252 }
ff3187f6 6253 } while (pktin || inlen > 0);
839f10db 6254 r = ssh->agent_response;
6255 s->responselen = ssh->agent_response_len;
6256 }
51470298 6257 s->response = (unsigned char *) r;
6258 if (s->response && s->responselen >= 5 &&
6259 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6260 s->p = s->response + 5;
6261 s->nkeys = GET_32BIT(s->p);
6262 s->p += 4;
32874aea 6263 {
6264 char buf[64];
51470298 6265 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 6266 logevent(buf);
6267 }
51470298 6268 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 6269 void *vret;
1983e559 6270
32874aea 6271 {
6272 char buf[64];
51470298 6273 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 6274 logevent(buf);
6275 }
51470298 6276 s->pklen = GET_32BIT(s->p);
6277 s->p += 4;
6278 if (s->publickey_blob &&
6279 s->pklen == s->publickey_bloblen &&
6280 !memcmp(s->p, s->publickey_blob,
6281 s->publickey_bloblen)) {
396778f1 6282 logevent("This key matches configured key file");
51470298 6283 s->tried_pubkey_config = 1;
396778f1 6284 }
d8baa528 6285 s->pkblob = (char *)s->p;
51470298 6286 s->p += s->pklen;
6287 s->alglen = GET_32BIT(s->pkblob);
6288 s->alg = s->pkblob + 4;
6289 s->commentlen = GET_32BIT(s->p);
6290 s->p += 4;
d8baa528 6291 s->commentp = (char *)s->p;
51470298 6292 s->p += s->commentlen;
ff3187f6 6293 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6294 ssh2_pkt_addstring(s->pktout, s->username);
6295 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6296 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6297 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6298 ssh2_pkt_addstring_start(s->pktout);
6299 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6300 ssh2_pkt_addstring_start(s->pktout);
6301 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6302 ssh2_pkt_send(ssh, s->pktout);
6303
6304 crWaitUntilV(pktin);
6305 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6306 logevent("Key refused");
6307 continue;
6308 }
6309
32874aea 6310 if (flags & FLAG_VERBOSE) {
51470298 6311 c_write_str(ssh, "Authenticating with "
6312 "public key \"");
6313 c_write(ssh, s->commentp, s->commentlen);
6314 c_write_str(ssh, "\" from agent\r\n");
32874aea 6315 }
1983e559 6316
6317 /*
6318 * Server is willing to accept the key.
6319 * Construct a SIGN_REQUEST.
6320 */
ff3187f6 6321 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6322 ssh2_pkt_addstring(s->pktout, s->username);
6323 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6324 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6325 ssh2_pkt_addbool(s->pktout, TRUE);
6326 ssh2_pkt_addstring_start(s->pktout);
6327 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6328 ssh2_pkt_addstring_start(s->pktout);
6329 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6330
6331 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 6332 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6333 s->siglen -= 4;
51470298 6334 s->len = 1; /* message type */
6335 s->len += 4 + s->pklen; /* key blob */
6336 s->len += 4 + s->siglen; /* data to sign */
6337 s->len += 4; /* flags */
3d88e64d 6338 s->agentreq = snewn(4 + s->len, char);
51470298 6339 PUT_32BIT(s->agentreq, s->len);
6340 s->q = s->agentreq + 4;
6341 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6342 PUT_32BIT(s->q, s->pklen);
6343 s->q += 4;
6344 memcpy(s->q, s->pkblob, s->pklen);
6345 s->q += s->pklen;
6346 PUT_32BIT(s->q, s->siglen);
6347 s->q += 4;
1983e559 6348 /* Now the data to be signed... */
dda87a28 6349 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6350 PUT_32BIT(s->q, 20);
6351 s->q += 4;
6352 }
51470298 6353 memcpy(s->q, ssh->v2_session_id, 20);
6354 s->q += 20;
ff3187f6 6355 memcpy(s->q, s->pktout->data + 5,
6356 s->pktout->length - 5);
6357 s->q += s->pktout->length - 5;
1983e559 6358 /* And finally the (zero) flags word. */
51470298 6359 PUT_32BIT(s->q, 0);
839f10db 6360 if (!agent_query(s->agentreq, s->len + 4,
6361 &vret, &s->retlen,
6362 ssh_agent_callback, ssh)) {
6363 do {
6364 crReturnV;
ff3187f6 6365 if (pktin) {
839f10db 6366 bombout(("Unexpected data from server"
6367 " while waiting for agent"
6368 " response"));
6369 crStopV;
6370 }
ff3187f6 6371 } while (pktin || inlen > 0);
839f10db 6372 vret = ssh->agent_response;
6373 s->retlen = ssh->agent_response_len;
6374 }
51470298 6375 s->ret = vret;
6376 sfree(s->agentreq);
6377 if (s->ret) {
6378 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 6379 logevent("Sending Pageant's response");
ff3187f6 6380 ssh2_add_sigblob(ssh, s->pktout,
6381 s->pkblob, s->pklen,
51470298 6382 s->ret + 9,
6383 GET_32BIT(s->ret + 5));
ff3187f6 6384 ssh2_pkt_send(ssh, s->pktout);
51470298 6385 s->authed = TRUE;
1983e559 6386 break;
6387 } else {
32874aea 6388 logevent
6389 ("Pageant failed to answer challenge");
51470298 6390 sfree(s->ret);
1983e559 6391 }
6392 }
6393 }
51470298 6394 if (s->authed)
1983e559 6395 continue;
6396 }
29b1d0b3 6397 sfree(s->response);
1983e559 6398 }
6399
51470298 6400 if (!s->method && s->can_pubkey && s->publickey_blob
6401 && !s->tried_pubkey_config) {
1408a877 6402 unsigned char *pub_blob;
6403 char *algorithm, *comment;
6404 int pub_blob_len;
65a22376 6405
51470298 6406 s->tried_pubkey_config = TRUE;
65a22376 6407
51470298 6408 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6409 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6410
65a22376 6411 /*
1408a877 6412 * Try the public key supplied in the configuration.
6413 *
6414 * First, offer the public blob to see if the server is
6415 * willing to accept it.
65a22376 6416 */
d8baa528 6417 pub_blob =
9a30e26b 6418 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6419 &algorithm,
222d54dc 6420 &pub_blob_len,
6421 NULL);
1408a877 6422 if (pub_blob) {
ff3187f6 6423 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6424 ssh2_pkt_addstring(s->pktout, s->username);
6425 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6426 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6427 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6428 ssh2_pkt_addstring(s->pktout, algorithm);
6429 ssh2_pkt_addstring_start(s->pktout);
6430 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6431 pub_blob_len);
ff3187f6 6432 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6433 logevent("Offered public key");
1408a877 6434
ff3187f6 6435 crWaitUntilV(pktin);
6436 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6437 s->gotit = TRUE;
6438 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6439 continue; /* key refused; give up on it */
1408a877 6440 }
65a22376 6441
1408a877 6442 logevent("Offer of public key accepted");
65a22376 6443 /*
1408a877 6444 * Actually attempt a serious authentication using
6445 * the key.
65a22376 6446 */
9a30e26b 6447 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6448 sprintf(s->pwprompt,
32874aea 6449 "Passphrase for key \"%.100s\": ",
6450 comment);
51470298 6451 s->need_pw = TRUE;
1408a877 6452 } else {
51470298 6453 s->need_pw = FALSE;
1408a877 6454 }
4e520718 6455 if (flags & FLAG_VERBOSE) {
6456 c_write_str(ssh, "Authenticating with public key \"");
6457 c_write_str(ssh, comment);
6458 c_write_str(ssh, "\"\r\n");
6459 }
51470298 6460 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6461 }
1408a877 6462 }
6463
6ac3a551 6464 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused) {
51470298 6465 s->method = AUTH_KEYBOARD_INTERACTIVE;
6466 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6467
51470298 6468 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6469 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6470
ff3187f6 6471 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6472 ssh2_pkt_addstring(s->pktout, s->username);
6473 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6474 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6475 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6476 ssh2_pkt_addstring(s->pktout, "");
6477 ssh2_pkt_send(ssh, s->pktout);
6478
6479 crWaitUntilV(pktin);
6480 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6481 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6482 s->gotit = TRUE;
af659722 6483 logevent("Keyboard-interactive authentication refused");
51470298 6484 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6ac3a551 6485 s->kbd_inter_refused = TRUE; /* don't try it again */
af659722 6486 continue;
6487 }
6488
51470298 6489 s->kbd_inter_running = TRUE;
6490 s->curr_prompt = 0;
af659722 6491 }
6492
51470298 6493 if (s->kbd_inter_running) {
6494 s->method = AUTH_KEYBOARD_INTERACTIVE;
6495 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6496
51470298 6497 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6498 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6499
51470298 6500 if (s->curr_prompt == 0) {
45068b27 6501 /*
6502 * We've got a fresh USERAUTH_INFO_REQUEST.
6503 * Display header data, and start going through
6504 * the prompts.
6505 */
6506 char *name, *inst, *lang;
6507 int name_len, inst_len, lang_len;
6508
ff3187f6 6509 ssh_pkt_getstring(pktin, &name, &name_len);
6510 ssh_pkt_getstring(pktin, &inst, &inst_len);
6511 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6512 if (name_len > 0) {
51470298 6513 c_write_untrusted(ssh, name, name_len);
6514 c_write_str(ssh, "\r\n");
45068b27 6515 }
6516 if (inst_len > 0) {
51470298 6517 c_write_untrusted(ssh, inst, inst_len);
6518 c_write_str(ssh, "\r\n");
45068b27 6519 }
ff3187f6 6520 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6521 }
af659722 6522
45068b27 6523 /*
6524 * If there are prompts remaining in the packet,
6525 * display one and get a response.
6526 */
51470298 6527 if (s->curr_prompt < s->num_prompts) {
45068b27 6528 char *prompt;
6529 int prompt_len;
af659722 6530
ff3187f6 6531 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6532 if (prompt_len > 0) {
85fdbe25 6533 static const char trunc[] = "<prompt truncated>: ";
6534 static const int prlen = sizeof(s->pwprompt) -
6535 lenof(trunc);
6536 if (prompt_len > prlen) {
6537 memcpy(s->pwprompt, prompt, prlen);
6538 strcpy(s->pwprompt + prlen, trunc);
6539 } else {
6540 memcpy(s->pwprompt, prompt, prompt_len);
6541 s->pwprompt[prompt_len] = '\0';
6542 }
45068b27 6543 } else {
51470298 6544 strcpy(s->pwprompt,
45068b27 6545 "<server failed to send prompt>: ");
6546 }
ff3187f6 6547 s->echo = ssh2_pkt_getbool(pktin);
51470298 6548 s->need_pw = TRUE;
45068b27 6549 } else
51470298 6550 s->need_pw = FALSE;
af659722 6551 }
6552
51470298 6553 if (!s->method && s->can_passwd) {
6554 s->method = AUTH_PASSWORD;
6555 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6556 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6557 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6558 ssh->savedhost);
6559 s->need_pw = TRUE;
1408a877 6560 }
6561
51470298 6562 if (s->need_pw) {
fa17a66e 6563 if (ssh_get_line) {
51470298 6564 if (!ssh_get_line(s->pwprompt, s->password,
6565 sizeof(s->password), TRUE)) {
1408a877 6566 /*
fa17a66e 6567 * get_line failed to get a password (for
6568 * example because one was supplied on the
6569 * command line which has already failed to
6570 * work). Terminate.
1408a877 6571 */
ff3187f6 6572 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6573 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6574 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6575 " to try");
ff3187f6 6576 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6577 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6578 logevent("Unable to authenticate");
a8327734 6579 connection_fatal(ssh->frontend,
6580 "Unable to authenticate");
3bb2f322 6581 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6582 crStopV;
1408a877 6583 }
6584 } else {
51470298 6585 int ret; /* need not be saved across crReturn */
6586 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6587 ssh->send_ok = 1;
1408a877 6588
51470298 6589 setup_userpass_input(ssh, s->password,
6590 sizeof(s->password), s->echo);
0405e71f 6591 do {
ff3187f6 6592 crWaitUntilV(!pktin);
51470298 6593 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6594 } while (ret == 0);
6595 if (ret < 0)
6596 cleanup_exit(0);
51470298 6597 c_write_str(ssh, "\r\n");
65a22376 6598 }
65a22376 6599 }
65a22376 6600
51470298 6601 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6602 /*
6603 * We have our passphrase. Now try the actual authentication.
6604 */
6605 struct ssh2_userkey *key;
222d54dc 6606 const char *error = NULL;
65a22376 6607
222d54dc 6608 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6609 &error);
1408a877 6610 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6611 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6612 c_write_str(ssh, "Wrong passphrase\r\n");
6613 s->tried_pubkey_config = FALSE;
1408a877 6614 } else {
222d54dc 6615 c_write_str(ssh, "Unable to load private key (");
6616 c_write_str(ssh, error);
6617 c_write_str(ssh, ")\r\n");
51470298 6618 s->tried_pubkey_config = TRUE;
1408a877 6619 }
6620 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6621 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6622 ssh2_pkt_addstring(s->pktout, s->username);
6623 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6624 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6625 ssh2_pkt_send(ssh, s->pktout);
51470298 6626 s->type = AUTH_TYPE_NONE;
1408a877 6627 } else {
1dd353b5 6628 unsigned char *pkblob, *sigblob, *sigdata;
6629 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6630 int p;
65a22376 6631
1408a877 6632 /*
6633 * We have loaded the private key and the server
6634 * has announced that it's willing to accept it.
6635 * Hallelujah. Generate a signature and send it.
6636 */
ff3187f6 6637 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6638 ssh2_pkt_addstring(s->pktout, s->username);
6639 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6640 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6641 ssh2_pkt_addbool(s->pktout, TRUE);
6642 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6643 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6644 ssh2_pkt_addstring_start(s->pktout);
6645 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6646
6647 /*
6648 * The data to be signed is:
6649 *
6650 * string session-id
6651 *
6652 * followed by everything so far placed in the
6653 * outgoing packet.
6654 */
ff3187f6 6655 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6656 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6657 sigdata_len -= 4;
92d60585 6658 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6659 p = 0;
6660 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6661 PUT_32BIT(sigdata+p, 20);
6662 p += 4;
6663 }
6664 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6665 memcpy(sigdata+p, s->pktout->data + 5,
6666 s->pktout->length - 5);
6667 p += s->pktout->length - 5;
dda87a28 6668 assert(p == sigdata_len);
d8baa528 6669 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6670 sigdata_len, &sigblob_len);
ff3187f6 6671 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6672 sigblob, sigblob_len);
6673 sfree(pkblob);
6674 sfree(sigblob);
1408a877 6675 sfree(sigdata);
6676
ff3187f6 6677 ssh2_pkt_send(ssh, s->pktout);
51470298 6678 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6679 key->alg->freekey(key->data);
1408a877 6680 }
51470298 6681 } else if (s->method == AUTH_PASSWORD) {
65a22376 6682 /*
1408a877 6683 * We send the password packet lumped tightly together with
6684 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6685 * string long enough to make the total length of the two
6686 * packets constant. This should ensure that a passive
6687 * listener doing traffic analyis can't work out the length
6688 * of the password.
6689 *
6690 * For this to work, we need an assumption about the
6691 * maximum length of the password packet. I think 256 is
6692 * pretty conservative. Anyone using a password longer than
6693 * that probably doesn't have much to worry about from
6694 * people who find out how long their password is!
65a22376 6695 */
ff3187f6 6696 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6697 ssh2_pkt_addstring(s->pktout, s->username);
6698 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6699 ssh2_pkt_addstring(s->pktout, "password");
6700 ssh2_pkt_addbool(s->pktout, FALSE);
6701 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6702 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 6703 memset(s->password, 0, sizeof(s->password));
ff3187f6 6704 end_log_omission(ssh, s->pktout);
6705 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6706 /*
1408a877 6707 * We'll include a string that's an exact multiple of the
6708 * cipher block size. If the cipher is NULL for some
6709 * reason, we don't do this trick at all because we gain
6710 * nothing by it.
65a22376 6711 */
51470298 6712 if (ssh->cscipher) {
32874aea 6713 int stringlen, i;
6714
51470298 6715 stringlen = (256 - ssh->deferred_len);
6716 stringlen += ssh->cscipher->blksize - 1;
6717 stringlen -= (stringlen % ssh->cscipher->blksize);
6718 if (ssh->cscomp) {
32874aea 6719 /*
6720 * Temporarily disable actual compression,
6721 * so we can guarantee to get this string
6722 * exactly the length we want it. The
6723 * compression-disabling routine should
6724 * return an integer indicating how many
6725 * bytes we should adjust our string length
6726 * by.
6727 */
5366aed8 6728 stringlen -=
6729 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 6730 }
ff3187f6 6731 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6732 ssh2_pkt_addstring_start(s->pktout);
6e9e9520 6733 for (i = 0; i < stringlen; i++) {
32874aea 6734 char c = (char) random_byte();
ff3187f6 6735 ssh2_pkt_addstring_data(s->pktout, &c, 1);
65a22376 6736 }
ff3187f6 6737 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6738 }
51470298 6739 ssh_pkt_defersend(ssh);
0d43337a 6740 logevent("Sent password");
51470298 6741 s->type = AUTH_TYPE_PASSWORD;
6742 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6743 if (s->curr_prompt == 0) {
ff3187f6 6744 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6745 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 6746 }
51470298 6747 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 6748 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6749 ssh2_pkt_addstring(s->pktout, s->password);
51470298 6750 memset(s->password, 0, sizeof(s->password));
ff3187f6 6751 end_log_omission(ssh, s->pktout);
51470298 6752 s->curr_prompt++;
45068b27 6753 }
51470298 6754 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 6755 ssh2_pkt_send(ssh, s->pktout);
45068b27 6756 } else {
6757 /*
6758 * If there are prompts remaining, we set
6759 * `gotit' so that we won't attempt to get
6760 * another packet. Then we go back round the
6761 * loop and will end up retrieving another
6762 * prompt out of the existing packet. Funky or
6763 * what?
6764 */
51470298 6765 s->gotit = TRUE;
45068b27 6766 }
51470298 6767 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 6768 } else {
51470298 6769 c_write_str(ssh, "No supported authentication methods"
6770 " left to try!\r\n");
6771 logevent("No supported authentications offered."
6772 " Disconnecting");
ff3187f6 6773 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6774 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6775 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 6776 " methods available");
ff3187f6 6777 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6778 ssh2_pkt_send_noqueue(ssh, s->pktout);
3bb2f322 6779 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6780 crStopV;
65a22376 6781 }
65a22376 6782 }
51470298 6783 } while (!s->we_are_in);
7cca0d81 6784
6785 /*
6786 * Now we're authenticated for the connection protocol. The
6787 * connection protocol will automatically have started at this
6788 * point; there's no need to send SERVICE_REQUEST.
6789 */
6790
0ed48730 6791 ssh->channels = newtree234(ssh_channelcmp);
6792
7cca0d81 6793 /*
b09eaa88 6794 * Set up handlers for some connection protocol messages, so we
6795 * don't have to handle them repeatedly in this coroutine.
6796 */
6797 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6798 ssh2_msg_channel_window_adjust;
51df0ab5 6799 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6800 ssh2_msg_global_request;
b09eaa88 6801
6802 /*
0ed48730 6803 * Create the main session channel.
7cca0d81 6804 */
0ed48730 6805 if (!ssh->cfg.ssh_no_shell) {
6806 ssh->mainchan = snew(struct ssh_channel);
6807 ssh->mainchan->ssh = ssh;
6808 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 6809 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6810 ssh2_pkt_addstring(s->pktout, "session");
6811 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 6812 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 6813 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6814 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6815 ssh2_pkt_send(ssh, s->pktout);
6816 crWaitUntilV(pktin);
6817 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 6818 bombout(("Server refused to open a session"));
6819 crStopV;
6820 /* FIXME: error data comes back in FAILURE packet */
6821 }
ff3187f6 6822 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 6823 bombout(("Server's channel confirmation cited wrong channel"));
6824 crStopV;
6825 }
ff3187f6 6826 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 6827 ssh->mainchan->type = CHAN_MAINSESSION;
6828 ssh->mainchan->closes = 0;
ff3187f6 6829 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6830 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 6831 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6832 add234(ssh->channels, ssh->mainchan);
62638676 6833 update_specials_menu(ssh->frontend);
0ed48730 6834 logevent("Opened channel for session");
6835 } else
6836 ssh->mainchan = NULL;
7cca0d81 6837
6838 /*
51df0ab5 6839 * Now we have a channel, make dispatch table entries for
6840 * general channel-based messages.
6841 */
6842 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6843 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6844 ssh2_msg_channel_data;
6845 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6846 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6847 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6848 ssh2_msg_channel_open_confirmation;
6849 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6850 ssh2_msg_channel_open_failure;
6851 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6852 ssh2_msg_channel_request;
6853 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6854 ssh2_msg_channel_open;
6855
6856 /*
783415f8 6857 * Potentially enable X11 forwarding.
6858 */
0ed48730 6859 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 6860 char proto[20], data[64];
6861 logevent("Requesting X11 forwarding");
302121de 6862 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 6863 data, sizeof(data), ssh->cfg.x11_auth);
6864 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 6865 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6866 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6867 ssh2_pkt_addstring(s->pktout, "x11-req");
6868 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6869 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6870 ssh2_pkt_addstring(s->pktout, proto);
6871 ssh2_pkt_addstring(s->pktout, data);
6872 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6873 ssh2_pkt_send(ssh, s->pktout);
32874aea 6874
b09eaa88 6875 crWaitUntilV(pktin);
32874aea 6876
ff3187f6 6877 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6878 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6879 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 6880 " packet type %d", pktin->type));
7ffdbc1a 6881 crStopV;
32874aea 6882 }
6883 logevent("X11 forwarding refused");
6884 } else {
6885 logevent("X11 forwarding enabled");
51470298 6886 ssh->X11_fwd_enabled = TRUE;
32874aea 6887 }
783415f8 6888 }
6889
6890 /*
bc240b21 6891 * Enable port forwardings.
6892 */
06fadff5 6893 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 6894
6895 /*
36c2a3e9 6896 * Potentially enable agent forwarding.
6897 */
0ed48730 6898 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6899 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6900 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6901 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6902 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6903 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6904 ssh2_pkt_send(ssh, s->pktout);
32874aea 6905
b09eaa88 6906 crWaitUntilV(pktin);
32874aea 6907
ff3187f6 6908 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6909 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6910 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6911 " packet type %d", pktin->type));
7ffdbc1a 6912 crStopV;
32874aea 6913 }
6914 logevent("Agent forwarding refused");
6915 } else {
6916 logevent("Agent forwarding enabled");
51470298 6917 ssh->agentfwd_enabled = TRUE;
32874aea 6918 }
36c2a3e9 6919 }
6920
6921 /*
7cca0d81 6922 * Now allocate a pty for the session.
6923 */
0ed48730 6924 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6925 /* Unpick the terminal-speed string. */
6926 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6927 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6928 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6929 /* Build the pty request. */
ff3187f6 6930 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6931 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6932 ssh2_pkt_addstring(s->pktout, "pty-req");
6933 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6934 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6935 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6936 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6937 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6938 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6939 ssh2_pkt_addstring_start(s->pktout);
6940 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6941 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6942 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6943 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6944 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6945 ssh2_pkt_send(ssh, s->pktout);
51470298 6946 ssh->state = SSH_STATE_INTERMED;
32874aea 6947
b09eaa88 6948 crWaitUntilV(pktin);
32874aea 6949
ff3187f6 6950 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6951 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6952 bombout(("Unexpected response to pty request:"
ff3187f6 6953 " packet type %d", pktin->type));
7ffdbc1a 6954 crStopV;
32874aea 6955 }
51470298 6956 c_write_str(ssh, "Server refused to allocate pty\r\n");
6957 ssh->editing = ssh->echoing = 1;
32874aea 6958 } else {
a5dd8467 6959 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 6960 ssh->ospeed, ssh->ispeed);
32874aea 6961 }
0965bee0 6962 } else {
51470298 6963 ssh->editing = ssh->echoing = 1;
7cca0d81 6964 }
6965
6966 /*
73feed4f 6967 * Send environment variables.
6968 *
6969 * Simplest thing here is to send all the requests at once, and
6970 * then wait for a whole bunch of successes or failures.
6971 */
6972 if (ssh->mainchan && *ssh->cfg.environmt) {
6973 char *e = ssh->cfg.environmt;
6974 char *var, *varend, *val;
6975
6976 s->num_env = 0;
6977
6978 while (*e) {
6979 var = e;
6980 while (*e && *e != '\t') e++;
6981 varend = e;
6982 if (*e == '\t') e++;
6983 val = e;
6984 while (*e) e++;
6985 e++;
6986
ff3187f6 6987 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6988 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6989 ssh2_pkt_addstring(s->pktout, "env");
6990 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6991 ssh2_pkt_addstring_start(s->pktout);
6992 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6993 ssh2_pkt_addstring(s->pktout, val);
6994 ssh2_pkt_send(ssh, s->pktout);
73feed4f 6995
6996 s->num_env++;
6997 }
6998
6999 logeventf(ssh, "Sent %d environment variables", s->num_env);
7000
7001 s->env_ok = 0;
7002 s->env_left = s->num_env;
7003
7004 while (s->env_left > 0) {
b09eaa88 7005 crWaitUntilV(pktin);
73feed4f 7006
ff3187f6 7007 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7008 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 7009 bombout(("Unexpected response to environment request:"
ff3187f6 7010 " packet type %d", pktin->type));
73feed4f 7011 crStopV;
7012 }
7013 } else {
7014 s->env_ok++;
7015 }
7016
7017 s->env_left--;
7018 }
7019
7020 if (s->env_ok == s->num_env) {
7021 logevent("All environment variables successfully set");
7022 } else if (s->env_ok == 0) {
7023 logevent("All environment variables refused");
7024 c_write_str(ssh, "Server refused to set environment variables\r\n");
7025 } else {
7026 logeventf(ssh, "%d environment variables refused",
7027 s->num_env - s->env_ok);
7028 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7029 }
7030 }
7031
7032 /*
fd5e5847 7033 * Start a shell or a remote command. We may have to attempt
7034 * this twice if the config data has provided a second choice
7035 * of command.
7cca0d81 7036 */
0ed48730 7037 if (ssh->mainchan) while (1) {
fd5e5847 7038 int subsys;
7039 char *cmd;
7040
51470298 7041 if (ssh->fallback_cmd) {
86916870 7042 subsys = ssh->cfg.ssh_subsys2;
7043 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 7044 } else {
86916870 7045 subsys = ssh->cfg.ssh_subsys;
7046 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 7047 }
7048
ff3187f6 7049 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7050 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 7051 if (subsys) {
ff3187f6 7052 ssh2_pkt_addstring(s->pktout, "subsystem");
7053 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7054 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7055 } else if (*cmd) {
ff3187f6 7056 ssh2_pkt_addstring(s->pktout, "exec");
7057 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7058 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7059 } else {
ff3187f6 7060 ssh2_pkt_addstring(s->pktout, "shell");
7061 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 7062 }
ff3187f6 7063 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 7064
7065 crWaitUntilV(pktin);
7066
ff3187f6 7067 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7068 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7069 bombout(("Unexpected response to shell/command request:"
ff3187f6 7070 " packet type %d", pktin->type));
7ffdbc1a 7071 crStopV;
fd5e5847 7072 }
7073 /*
7074 * We failed to start the command. If this is the
7075 * fallback command, we really are finished; if it's
7076 * not, and if the fallback command exists, try falling
7077 * back to it before complaining.
7078 */
86916870 7079 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7080 logevent("Primary command failed; attempting fallback");
51470298 7081 ssh->fallback_cmd = TRUE;
fd5e5847 7082 continue;
7083 }
6b5cf8b4 7084 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7085 crStopV;
fd5e5847 7086 } else {
7087 logevent("Started a shell/command");
32874aea 7088 }
fd5e5847 7089 break;
7cca0d81 7090 }
7091
51470298 7092 ssh->state = SSH_STATE_SESSION;
7093 if (ssh->size_needed)
7094 ssh_size(ssh, ssh->term_width, ssh->term_height);
7095 if (ssh->eof_needed)
7096 ssh_special(ssh, TS_EOF);
6e48c3fe 7097
7cca0d81 7098 /*
7099 * Transfer data!
7100 */
b9d7bcad 7101 if (ssh->ldisc)
7102 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7103 if (ssh->mainchan)
7104 ssh->send_ok = 1;
7cca0d81 7105 while (1) {
e5574168 7106 crReturnV;
51470298 7107 s->try_send = FALSE;
ff3187f6 7108 if (pktin) {
2b7540a7 7109
51df0ab5 7110 /*
7111 * _All_ the connection-layer packets we expect to
7112 * receive are now handled by the dispatch table.
7113 * Anything that reaches here must be bogus.
7114 */
32874aea 7115
51df0ab5 7116 bombout(("Strange packet received: type %d", pktin->type));
7117 crStopV;
0ed48730 7118 } else if (ssh->mainchan) {
32874aea 7119 /*
7120 * We have spare data. Add it to the channel buffer.
7121 */
d8baa528 7122 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7123 s->try_send = TRUE;
32874aea 7124 }
51470298 7125 if (s->try_send) {
32874aea 7126 int i;
7127 struct ssh_channel *c;
7128 /*
7129 * Try to send data on all channels if we can.
7130 */
51470298 7131 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 7132 int bufsize;
7133 if (c->closes)
7134 continue; /* don't send on closing channels */
7135 bufsize = ssh2_try_send(c);
5471d09a 7136 if (bufsize == 0) {
7137 switch (c->type) {
7138 case CHAN_MAINSESSION:
7139 /* stdin need not receive an unthrottle
7140 * notification since it will be polled */
7141 break;
7142 case CHAN_X11:
7143 x11_unthrottle(c->u.x11.s);
7144 break;
7145 case CHAN_AGENT:
7146 /* agent sockets are request/response and need no
7147 * buffer management */
7148 break;
7149 case CHAN_SOCKDATA:
7150 pfd_unthrottle(c->u.pfd.s);
7151 break;
7152 }
7153 }
7154 }
7cca0d81 7155 }
e5574168 7156 }
7157
7158 crFinishV;
7159}
7160
7161/*
b09eaa88 7162 * Handlers for SSH2 messages that might arrive at any moment.
7163 */
7164void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7165{
7166 /* log reason code in disconnect message */
7167 char *buf, *msg;
7168 int nowlen, reason, msglen;
7169
7170 reason = ssh_pkt_getuint32(pktin);
7171 ssh_pkt_getstring(pktin, &msg, &msglen);
7172
7173 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7174 buf = dupprintf("Received disconnect message (%s)",
7175 ssh2_disconnect_reasons[reason]);
7176 } else {
7177 buf = dupprintf("Received disconnect message (unknown"
7178 " type %d)", reason);
7179 }
7180 logevent(buf);
7181 sfree(buf);
7182 buf = dupprintf("Disconnection message text: %n%.*s",
7183 &nowlen, msglen, msg);
7184 logevent(buf);
7185 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7186 reason,
7187 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7188 ssh2_disconnect_reasons[reason] : "unknown",
7189 buf+nowlen));
7190 sfree(buf);
7191}
7192
7193void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7194{
7195 /* log the debug message */
7196 char *buf, *msg;
7197 int msglen;
7198 int always_display;
7199
7200 /* XXX maybe we should actually take notice of this */
7201 always_display = ssh2_pkt_getbool(pktin);
7202 ssh_pkt_getstring(pktin, &msg, &msglen);
7203
7204 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7205 logevent(buf);
7206 sfree(buf);
7207}
7208
7209void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7210{
7211 struct Packet *pktout;
7212 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7213 ssh2_pkt_adduint32(pktout, pktin->sequence);
7214 /*
7215 * UNIMPLEMENTED messages MUST appear in the same order as the
7216 * messages they respond to. Hence, never queue them.
7217 */
7218 ssh2_pkt_send_noqueue(ssh, pktout);
7219}
7220
7221/*
7cca0d81 7222 * Handle the top-level SSH2 protocol.
7223 */
b09eaa88 7224static void ssh2_protocol_setup(Ssh ssh)
7225{
7226 int i;
7227
7228 /*
7229 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7230 */
7231 for (i = 0; i < 256; i++)
7232 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7233
7234 /*
7235 * Any message we actually understand, we set to NULL so that
7236 * the coroutines will get it.
7237 */
7238 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7239 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7240 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7241 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7242 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7243 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7244 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7245 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7246 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7247 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7248 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7249 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7250 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7251 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7252 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7253 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7254 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7255 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7256 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7257 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7258 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7259 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7260 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7261 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7262 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7263 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7264 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7265 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7266 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7267 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7268 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7269 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7270 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7271
7272 /*
7273 * These special message types we install handlers for.
7274 */
7275 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7276 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7277 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7278}
7279
9442dd57 7280static void ssh2_timer(void *ctx, long now)
7281{
7282 Ssh ssh = (Ssh)ctx;
7283
e6c1536e 7284 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 7285 now - ssh->next_rekey >= 0) {
7286 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7287 -1, NULL);
7288 }
7289}
7290
ff3187f6 7291static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7292 struct Packet *pktin)
7cca0d81 7293{
b09eaa88 7294 if (ssh->state == SSH_STATE_CLOSED)
7295 return;
7296
9442dd57 7297 if (pktin) {
7298 ssh->incoming_data_size += pktin->encrypted_len;
7299 if (!ssh->kex_in_progress &&
d57f70af 7300 ssh->max_data_size != 0 &&
7301 ssh->incoming_data_size > ssh->max_data_size)
9442dd57 7302 do_ssh2_transport(ssh, "Initiating key re-exchange "
7303 "(too much data received)", -1, NULL);
7304 }
7305
b09eaa88 7306 if (pktin && ssh->packet_dispatch[pktin->type]) {
7307 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7308 return;
b09eaa88 7309 }
7310
7311 if (!ssh->protocol_initial_phase_done ||
7312 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7313 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7314 !ssh->protocol_initial_phase_done) {
7315 ssh->protocol_initial_phase_done = TRUE;
7316 /*
7317 * Allow authconn to initialise itself.
7318 */
7319 do_ssh2_authconn(ssh, NULL, 0, NULL);
7320 }
7321 } else {
7322 do_ssh2_authconn(ssh, in, inlen, pktin);
7323 }
7cca0d81 7324}
7325
7326/*
8df7a775 7327 * Called to set up the connection.
374330e2 7328 *
7329 * Returns an error message, or NULL on success.
374330e2 7330 */
cbe2d68f 7331static const char *ssh_init(void *frontend_handle, void **backend_handle,
7332 Config *cfg,
79bf227b 7333 char *host, int port, char **realhost, int nodelay,
7334 int keepalive)
32874aea 7335{
cbe2d68f 7336 const char *p;
51470298 7337 Ssh ssh;
7338
3d88e64d 7339 ssh = snew(struct ssh_tag);
86916870 7340 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7341 ssh->version = 0; /* when not ready yet */
51470298 7342 ssh->s = NULL;
7343 ssh->cipher = NULL;
371e569c 7344 ssh->v1_cipher_ctx = NULL;
0183b242 7345 ssh->crcda_ctx = NULL;
51470298 7346 ssh->cscipher = NULL;
371e569c 7347 ssh->cs_cipher_ctx = NULL;
51470298 7348 ssh->sccipher = NULL;
371e569c 7349 ssh->sc_cipher_ctx = NULL;
51470298 7350 ssh->csmac = NULL;
a8327734 7351 ssh->cs_mac_ctx = NULL;
51470298 7352 ssh->scmac = NULL;
e0e1a00d 7353 ssh->sc_mac_ctx = NULL;
51470298 7354 ssh->cscomp = NULL;
5366aed8 7355 ssh->cs_comp_ctx = NULL;
51470298 7356 ssh->sccomp = NULL;
5366aed8 7357 ssh->sc_comp_ctx = NULL;
51470298 7358 ssh->kex = NULL;
389aa499 7359 ssh->kex_ctx = NULL;
51470298 7360 ssh->hostkey = NULL;
7361 ssh->exitcode = -1;
7362 ssh->state = SSH_STATE_PREPACKET;
7363 ssh->size_needed = FALSE;
7364 ssh->eof_needed = FALSE;
b9d7bcad 7365 ssh->ldisc = NULL;
a8327734 7366 ssh->logctx = NULL;
51470298 7367 ssh->deferred_send_data = NULL;
7368 ssh->deferred_len = 0;
7369 ssh->deferred_size = 0;
7370 ssh->fallback_cmd = 0;
7371 ssh->pkt_ctx = 0;
302121de 7372 ssh->x11auth = NULL;
be738459 7373 ssh->v1_compressing = FALSE;
51470298 7374 ssh->v2_outgoing_sequence = 0;
7375 ssh->ssh1_rdpkt_crstate = 0;
7376 ssh->ssh2_rdpkt_crstate = 0;
7377 ssh->do_ssh_init_crstate = 0;
7378 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7379 ssh->do_ssh1_connection_crstate = 0;
51470298 7380 ssh->do_ssh1_login_crstate = 0;
7381 ssh->do_ssh2_transport_crstate = 0;
7382 ssh->do_ssh2_authconn_crstate = 0;
7383 ssh->do_ssh_init_state = NULL;
7384 ssh->do_ssh1_login_state = NULL;
7385 ssh->do_ssh2_transport_state = NULL;
7386 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7387 ssh->mainchan = NULL;
968d2d92 7388 ssh->throttled_all = 0;
7389 ssh->v1_stdout_throttling = 0;
590f6a5f 7390 ssh->queue = NULL;
7391 ssh->queuelen = ssh->queuesize = 0;
7392 ssh->queueing = FALSE;
06fadff5 7393 ssh->qhead = ssh->qtail = NULL;
e13bba36 7394 ssh->deferred_rekey_reason = NULL;
51470298 7395
7396 *backend_handle = ssh;
32874aea 7397
8f203108 7398#ifdef MSCRYPTOAPI
32874aea 7399 if (crypto_startup() == 0)
8f203108 7400 return "Microsoft high encryption pack not installed!";
7401#endif
374330e2 7402
51470298 7403 ssh->frontend = frontend_handle;
86916870 7404 ssh->term_width = ssh->cfg.width;
7405 ssh->term_height = ssh->cfg.height;
887035a5 7406
fabd1805 7407 ssh->channels = NULL;
7408 ssh->rportfwds = NULL;
f47a5ffb 7409 ssh->portfwds = NULL;
fabd1805 7410
51470298 7411 ssh->send_ok = 0;
7412 ssh->editing = 0;
7413 ssh->echoing = 0;
7414 ssh->v1_throttle_count = 0;
7415 ssh->overall_bufsize = 0;
7416 ssh->fallback_cmd = 0;
8df7a775 7417
3648d4c5 7418 ssh->protocol = NULL;
7419
b09eaa88 7420 ssh->protocol_initial_phase_done = FALSE;
7421
39934deb 7422 ssh->pinger = NULL;
7423
9442dd57 7424 ssh->incoming_data_size = ssh->outgoing_data_size =
7425 ssh->deferred_data_size = 0L;
d57f70af 7426 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 7427 ssh->kex_in_progress = FALSE;
7428
79bf227b 7429 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7430 if (p != NULL)
7431 return p;
374330e2 7432
5d17ccfc 7433 random_ref();
7434
374330e2 7435 return NULL;
7436}
7437
fabd1805 7438static void ssh_free(void *handle)
7439{
7440 Ssh ssh = (Ssh) handle;
7441 struct ssh_channel *c;
7442 struct ssh_rportfwd *pf;
7443
7444 if (ssh->v1_cipher_ctx)
7445 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7446 if (ssh->cs_cipher_ctx)
7447 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7448 if (ssh->sc_cipher_ctx)
7449 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7450 if (ssh->cs_mac_ctx)
7451 ssh->csmac->free_context(ssh->cs_mac_ctx);
7452 if (ssh->sc_mac_ctx)
7453 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7454 if (ssh->cs_comp_ctx) {
7455 if (ssh->cscomp)
7456 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7457 else
7458 zlib_compress_cleanup(ssh->cs_comp_ctx);
7459 }
7460 if (ssh->sc_comp_ctx) {
7461 if (ssh->sccomp)
7462 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7463 else
7464 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7465 }
fabd1805 7466 if (ssh->kex_ctx)
7467 dh_cleanup(ssh->kex_ctx);
7468 sfree(ssh->savedhost);
7469
590f6a5f 7470 while (ssh->queuelen-- > 0)
7471 ssh_free_packet(ssh->queue[ssh->queuelen]);
7472 sfree(ssh->queue);
7473
06fadff5 7474 while (ssh->qhead) {
7475 struct queued_handler *qh = ssh->qhead;
7476 ssh->qhead = qh->next;
7477 sfree(ssh->qhead);
7478 }
7479 ssh->qhead = ssh->qtail = NULL;
7480
fabd1805 7481 if (ssh->channels) {
7482 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7483 switch (c->type) {
7484 case CHAN_X11:
7485 if (c->u.x11.s != NULL)
7486 x11_close(c->u.x11.s);
7487 break;
7488 case CHAN_SOCKDATA:
7489 if (c->u.pfd.s != NULL)
7490 pfd_close(c->u.pfd.s);
7491 break;
7492 }
7493 sfree(c);
7494 }
7495 freetree234(ssh->channels);
cdb52705 7496 ssh->channels = NULL;
fabd1805 7497 }
7498
7499 if (ssh->rportfwds) {
7500 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7501 sfree(pf);
7502 freetree234(ssh->rportfwds);
cdb52705 7503 ssh->rportfwds = NULL;
fabd1805 7504 }
7505 sfree(ssh->deferred_send_data);
7506 if (ssh->x11auth)
7507 x11_free_auth(ssh->x11auth);
7508 sfree(ssh->do_ssh_init_state);
7509 sfree(ssh->do_ssh1_login_state);
7510 sfree(ssh->do_ssh2_transport_state);
7511 sfree(ssh->do_ssh2_authconn_state);
679539d7 7512 if (ssh->crcda_ctx) {
7513 crcda_free_context(ssh->crcda_ctx);
7514 ssh->crcda_ctx = NULL;
7515 }
fabd1805 7516 if (ssh->s)
36f94d1f 7517 ssh_do_close(ssh);
9442dd57 7518 expire_timer_context(ssh);
39934deb 7519 if (ssh->pinger)
7520 pinger_free(ssh->pinger);
ee50e8b6 7521 sfree(ssh);
5d17ccfc 7522
7523 random_unref();
fabd1805 7524}
7525
374330e2 7526/*
86916870 7527 * Reconfigure the SSH backend.
86916870 7528 */
7529static void ssh_reconfig(void *handle, Config *cfg)
7530{
7531 Ssh ssh = (Ssh) handle;
e13bba36 7532 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 7533 unsigned long old_max_data_size;
7534
39934deb 7535 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
fda2feb1 7536 ssh_setup_portfwd(ssh, cfg);
e6c1536e 7537
7538 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7539 cfg->ssh_rekey_time != 0) {
7540 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7541 long now = GETTICKCOUNT();
7542
7543 if (new_next - now < 0) {
7544 rekeying = "Initiating key re-exchange (timeout shortened)";
7545 } else {
7546 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7547 }
7548 }
7549
7550 old_max_data_size = ssh->max_data_size;
7551 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7552 if (old_max_data_size != ssh->max_data_size &&
7553 ssh->max_data_size != 0) {
7554 if (ssh->outgoing_data_size > ssh->max_data_size ||
7555 ssh->incoming_data_size > ssh->max_data_size)
7556 rekeying = "Initiating key re-exchange (data limit lowered)";
7557 }
7558
e13bba36 7559 if (ssh->cfg.compression != cfg->compression) {
7560 rekeying = "Initiating key re-exchange (compression setting changed)";
7561 rekey_mandatory = TRUE;
7562 }
7563
7564 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7565 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7566 sizeof(ssh->cfg.ssh_cipherlist))) {
7567 rekeying = "Initiating key re-exchange (cipher settings changed)";
7568 rekey_mandatory = TRUE;
e6c1536e 7569 }
7570
86916870 7571 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 7572
7573 if (rekeying) {
7574 if (!ssh->kex_in_progress) {
7575 do_ssh2_transport(ssh, rekeying, -1, NULL);
7576 } else if (rekey_mandatory) {
7577 ssh->deferred_rekey_reason = rekeying;
7578 }
7579 }
86916870 7580}
7581
7582/*
374330e2 7583 * Called to send data down the Telnet connection.
7584 */
51470298 7585static int ssh_send(void *handle, char *buf, int len)
32874aea 7586{
51470298 7587 Ssh ssh = (Ssh) handle;
7588
7589 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7590 return 0;
374330e2 7591
d8baa528 7592 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7593
51470298 7594 return ssh_sendbuffer(ssh);
5471d09a 7595}
7596
7597/*
7598 * Called to query the current amount of buffered stdin data.
7599 */
51470298 7600static int ssh_sendbuffer(void *handle)
5471d09a 7601{
51470298 7602 Ssh ssh = (Ssh) handle;
5471d09a 7603 int override_value;
7604
51470298 7605 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7606 return 0;
7607
7608 /*
7609 * If the SSH socket itself has backed up, add the total backup
7610 * size on that to any individual buffer on the stdin channel.
7611 */
7612 override_value = 0;
51470298 7613 if (ssh->throttled_all)
7614 override_value = ssh->overall_bufsize;
5471d09a 7615
51470298 7616 if (ssh->version == 1) {
5471d09a 7617 return override_value;
51470298 7618 } else if (ssh->version == 2) {
7619 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7620 return override_value;
7621 else
51470298 7622 return (override_value +
7623 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7624 }
7625
7626 return 0;
374330e2 7627}
7628
7629/*
6e48c3fe 7630 * Called to set the size of the window from SSH's POV.
374330e2 7631 */
51470298 7632static void ssh_size(void *handle, int width, int height)
32874aea 7633{
51470298 7634 Ssh ssh = (Ssh) handle;
ff3187f6 7635 struct Packet *pktout;
51470298 7636
7637 ssh->term_width = width;
7638 ssh->term_height = height;
f278d6f8 7639
51470298 7640 switch (ssh->state) {
374330e2 7641 case SSH_STATE_BEFORE_SIZE:
3687d221 7642 case SSH_STATE_PREPACKET:
21248260 7643 case SSH_STATE_CLOSED:
374330e2 7644 break; /* do nothing */
7645 case SSH_STATE_INTERMED:
51470298 7646 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7647 break;
7648 case SSH_STATE_SESSION:
86916870 7649 if (!ssh->cfg.nopty) {
51470298 7650 if (ssh->version == 1) {
7651 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7652 PKT_INT, ssh->term_height,
7653 PKT_INT, ssh->term_width,
32874aea 7654 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7655 } else if (ssh->mainchan) {
ff3187f6 7656 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7657 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7658 ssh2_pkt_addstring(pktout, "window-change");
7659 ssh2_pkt_addbool(pktout, 0);
7660 ssh2_pkt_adduint32(pktout, ssh->term_width);
7661 ssh2_pkt_adduint32(pktout, ssh->term_height);
7662 ssh2_pkt_adduint32(pktout, 0);
7663 ssh2_pkt_adduint32(pktout, 0);
7664 ssh2_pkt_send(ssh, pktout);
32874aea 7665 }
7666 }
7667 break;
374330e2 7668 }
7669}
7670
7671/*
125105d1 7672 * Return a list of the special codes that make sense in this
7673 * protocol.
7674 */
7675static const struct telnet_special *ssh_get_specials(void *handle)
7676{
786ba75e 7677 static const struct telnet_special ssh1_ignore_special[] = {
7678 {"IGNORE message", TS_NOP}
7679 };
7680 static const struct telnet_special ssh2_transport_specials[] = {
62638676 7681 {"IGNORE message", TS_NOP},
9442dd57 7682 {"Repeat key exchange", TS_REKEY},
62638676 7683 };
7684 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7685 {NULL, TS_SEP},
7686 {"Break", TS_BRK},
786ba75e 7687 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 7688 * They include all the ISO C signals, but are a subset of the POSIX
7689 * required signals. */
7690 {"SIGINT (Interrupt)", TS_SIGINT},
7691 {"SIGTERM (Terminate)", TS_SIGTERM},
7692 {"SIGKILL (Kill)", TS_SIGKILL},
7693 {"SIGQUIT (Quit)", TS_SIGQUIT},
7694 {"SIGHUP (Hangup)", TS_SIGHUP},
7695 {"More signals", TS_SUBMENU},
7696 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7697 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7698 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7699 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7700 {NULL, TS_EXITMENU}
62638676 7701 };
7702 static const struct telnet_special specials_end[] = {
6f2d0cde 7703 {NULL, TS_EXITMENU}
62638676 7704 };
786ba75e 7705 /* XXX review this length for any changes: */
7706 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 7707 lenof(ssh2_session_specials) +
7708 lenof(specials_end)];
125105d1 7709 Ssh ssh = (Ssh) handle;
62638676 7710 int i = 0;
7711#define ADD_SPECIALS(name) \
7712 do { \
7713 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7714 memcpy(&ssh_specials[i], name, sizeof name); \
7715 i += lenof(name); \
7716 } while(0)
125105d1 7717
7718 if (ssh->version == 1) {
62638676 7719 /* Don't bother offering IGNORE if we've decided the remote
7720 * won't cope with it, since we wouldn't bother sending it if
7721 * asked anyway. */
7722 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 7723 ADD_SPECIALS(ssh1_ignore_special);
125105d1 7724 } else if (ssh->version == 2) {
786ba75e 7725 ADD_SPECIALS(ssh2_transport_specials);
62638676 7726 if (ssh->mainchan)
7727 ADD_SPECIALS(ssh2_session_specials);
7728 } /* else we're not ready yet */
7729
7730 if (i) {
7731 ADD_SPECIALS(specials_end);
7732 return ssh_specials;
7733 } else {
125105d1 7734 return NULL;
62638676 7735 }
7736#undef ADD_SPECIALS
125105d1 7737}
7738
7739/*
6abbf9e3 7740 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7741 * can send an EOF and collect resulting output (e.g. `plink
7742 * hostname sort').
374330e2 7743 */
51470298 7744static void ssh_special(void *handle, Telnet_Special code)
32874aea 7745{
51470298 7746 Ssh ssh = (Ssh) handle;
ff3187f6 7747 struct Packet *pktout;
51470298 7748
6abbf9e3 7749 if (code == TS_EOF) {
51470298 7750 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7751 /*
7752 * Buffer the EOF in case we are pre-SESSION, so we can
7753 * send it as soon as we reach SESSION.
7754 */
7755 if (code == TS_EOF)
51470298 7756 ssh->eof_needed = TRUE;
32874aea 7757 return;
7758 }
51470298 7759 if (ssh->version == 1) {
7760 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7761 } else if (ssh->mainchan) {
ff3187f6 7762 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7763 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7764 ssh2_pkt_send(ssh, pktout);
32874aea 7765 }
7766 logevent("Sent EOF message");
125105d1 7767 } else if (code == TS_PING || code == TS_NOP) {
51470298 7768 if (ssh->state == SSH_STATE_CLOSED
7769 || ssh->state == SSH_STATE_PREPACKET) return;
7770 if (ssh->version == 1) {
7771 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7772 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7773 } else {
ff3187f6 7774 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7775 ssh2_pkt_addstring_start(pktout);
590f6a5f 7776 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7777 }
9442dd57 7778 } else if (code == TS_REKEY) {
7779 if (!ssh->kex_in_progress && ssh->version == 2) {
7780 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7781 " user request", -1, NULL);
7782 }
125105d1 7783 } else if (code == TS_BRK) {
7784 if (ssh->state == SSH_STATE_CLOSED
7785 || ssh->state == SSH_STATE_PREPACKET) return;
7786 if (ssh->version == 1) {
7787 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7788 } else if (ssh->mainchan) {
ff3187f6 7789 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7790 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7791 ssh2_pkt_addstring(pktout, "break");
7792 ssh2_pkt_addbool(pktout, 0);
7793 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7794 ssh2_pkt_send(ssh, pktout);
125105d1 7795 }
6abbf9e3 7796 } else {
6f2d0cde 7797 /* Is is a POSIX signal? */
7798 char *signame = NULL;
7799 if (code == TS_SIGABRT) signame = "ABRT";
7800 if (code == TS_SIGALRM) signame = "ALRM";
7801 if (code == TS_SIGFPE) signame = "FPE";
7802 if (code == TS_SIGHUP) signame = "HUP";
7803 if (code == TS_SIGILL) signame = "ILL";
7804 if (code == TS_SIGINT) signame = "INT";
7805 if (code == TS_SIGKILL) signame = "KILL";
7806 if (code == TS_SIGPIPE) signame = "PIPE";
7807 if (code == TS_SIGQUIT) signame = "QUIT";
7808 if (code == TS_SIGSEGV) signame = "SEGV";
7809 if (code == TS_SIGTERM) signame = "TERM";
7810 if (code == TS_SIGUSR1) signame = "USR1";
7811 if (code == TS_SIGUSR2) signame = "USR2";
7812 /* The SSH-2 protocol does in principle support arbitrary named
7813 * signals, including signame@domain, but we don't support those. */
7814 if (signame) {
7815 /* It's a signal. */
7816 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7817 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7818 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7819 ssh2_pkt_addstring(pktout, "signal");
7820 ssh2_pkt_addbool(pktout, 0);
7821 ssh2_pkt_addstring(pktout, signame);
7822 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7823 logeventf(ssh, "Sent signal SIG%s", signame);
7824 }
7825 } else {
7826 /* Never heard of it. Do nothing */
7827 }
6abbf9e3 7828 }
374330e2 7829}
7830
51470298 7831void *new_sock_channel(void *handle, Socket s)
d74d141c 7832{
51470298 7833 Ssh ssh = (Ssh) handle;
d74d141c 7834 struct ssh_channel *c;
3d88e64d 7835 c = snew(struct ssh_channel);
51470298 7836 c->ssh = ssh;
d74d141c 7837
7838 if (c) {
bc240b21 7839 c->remoteid = -1; /* to be set when open confirmed */
51470298 7840 c->localid = alloc_channel_id(ssh);
d74d141c 7841 c->closes = 0;
bc240b21 7842 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7843 c->u.pfd.s = s;
013dd8c0 7844 bufchain_init(&c->v.v2.outbuffer);
51470298 7845 add234(ssh->channels, c);
d74d141c 7846 }
7847 return c;
7848}
7849
5471d09a 7850/*
7851 * This is called when stdout/stderr (the entity to which
7852 * from_backend sends data) manages to clear some backlog.
7853 */
ae9ae89f 7854static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7855{
51470298 7856 Ssh ssh = (Ssh) handle;
7857 if (ssh->version == 1) {
7858 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7859 ssh->v1_stdout_throttling = 0;
7860 ssh1_throttle(ssh, -1);
5471d09a 7861 }
7862 } else {
51470298 7863 if (ssh->mainchan && ssh->mainchan->closes == 0)
7864 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7865 }
7866}
7867
6b78788a 7868void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7869{
7870 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7871 Ssh ssh = c->ssh;
ff3187f6 7872 struct Packet *pktout;
d74d141c 7873
57356d63 7874 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7875
51470298 7876 if (ssh->version == 1) {
7877 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7878 PKT_INT, c->localid,
7879 PKT_STR, hostname,
7880 PKT_INT, port,
31fb1866 7881 /* PKT_STR, <org:orgport>, */
bc240b21 7882 PKT_END);
7883 } else {
ff3187f6 7884 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7885 ssh2_pkt_addstring(pktout, "direct-tcpip");
7886 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7887 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7888 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7889 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7890 ssh2_pkt_addstring(pktout, hostname);
7891 ssh2_pkt_adduint32(pktout, port);
bc240b21 7892 /*
7893 * We make up values for the originator data; partly it's
7894 * too much hassle to keep track, and partly I'm not
7895 * convinced the server should be told details like that
7896 * about my local network configuration.
7897 */
ff3187f6 7898 ssh2_pkt_addstring(pktout, "client-side-connection");
7899 ssh2_pkt_adduint32(pktout, 0);
7900 ssh2_pkt_send(ssh, pktout);
bc240b21 7901 }
d74d141c 7902}
7903
51470298 7904static Socket ssh_socket(void *handle)
32874aea 7905{
51470298 7906 Ssh ssh = (Ssh) handle;
7907 return ssh->s;
32874aea 7908}
8ccc75b0 7909
51470298 7910static int ssh_sendok(void *handle)
32874aea 7911{
51470298 7912 Ssh ssh = (Ssh) handle;
7913 return ssh->send_ok;
32874aea 7914}
fb09bf1c 7915
51470298 7916static int ssh_ldisc(void *handle, int option)
32874aea 7917{
51470298 7918 Ssh ssh = (Ssh) handle;
32874aea 7919 if (option == LD_ECHO)
51470298 7920 return ssh->echoing;
32874aea 7921 if (option == LD_EDIT)
51470298 7922 return ssh->editing;
0965bee0 7923 return FALSE;
7924}
7925
b9d7bcad 7926static void ssh_provide_ldisc(void *handle, void *ldisc)
7927{
7928 Ssh ssh = (Ssh) handle;
7929 ssh->ldisc = ldisc;
7930}
7931
a8327734 7932static void ssh_provide_logctx(void *handle, void *logctx)
7933{
7934 Ssh ssh = (Ssh) handle;
7935 ssh->logctx = logctx;
7936}
7937
51470298 7938static int ssh_return_exitcode(void *handle)
7939{
7940 Ssh ssh = (Ssh) handle;
3bb2f322 7941 if (ssh->s != NULL)
7942 return -1;
7943 else
7944 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7945}
7946
7947/*
f89c3294 7948 * cfg_info for SSH is the currently running version of the
7949 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
7950 */
7951static int ssh_cfg_info(void *handle)
7952{
7953 Ssh ssh = (Ssh) handle;
7954 return ssh->version;
7955}
7956
7957/*
51470298 7958 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7959 * that fails. This variable is the means by which scp.c can reach
7960 * into the SSH code and find out which one it got.
7961 */
7962extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7963{
51470298 7964 Ssh ssh = (Ssh) handle;
7965 return ssh->fallback_cmd;
d8d6c7e5 7966}
7967
374330e2 7968Backend ssh_backend = {
7969 ssh_init,
fabd1805 7970 ssh_free,
86916870 7971 ssh_reconfig,
374330e2 7972 ssh_send,
5471d09a 7973 ssh_sendbuffer,
374330e2 7974 ssh_size,
4017be6d 7975 ssh_special,
125105d1 7976 ssh_get_specials,
8ccc75b0 7977 ssh_socket,
d8d6c7e5 7978 ssh_return_exitcode,
97db3be4 7979 ssh_sendok,
0965bee0 7980 ssh_ldisc,
b9d7bcad 7981 ssh_provide_ldisc,
a8327734 7982 ssh_provide_logctx,
5471d09a 7983 ssh_unthrottle,
f89c3294 7984 ssh_cfg_info,
97db3be4 7985 22
bc240b21 7986};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator