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Pageant is now able to avoid asking for the passphrase when asked to
[u/mdw/putty] / ssh.c
CommitLineData
8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
b4453f49 20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
fb09bf1c 21
3cd52910 22#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
4a8fc3c4 23 (s ? sk_close(s), s = NULL : 0), \
3cd52910 24 connection_fatal msg )
8d5de777 25
32874aea 26#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29#define SSH1_CMSG_USER 4 /* 0x4 */
30#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38#define SSH1_SMSG_SUCCESS 14 /* 0xe */
39#define SSH1_SMSG_FAILURE 15 /* 0xf */
40#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43#define SSH1_CMSG_EOF 19 /* 0x13 */
44#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
50#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
53#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
55#define SSH1_MSG_IGNORE 32 /* 0x20 */
56#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
59#define SSH1_MSG_DEBUG 36 /* 0x24 */
60#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
61#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
67
68#define SSH1_AUTH_TIS 5 /* 0x5 */
69#define SSH1_AUTH_CCARD 16 /* 0x10 */
70
71#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 72/* Mask for protoflags we will echo back to server if seen */
32874aea 73#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
74
75#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
76#define SSH2_MSG_IGNORE 2 /* 0x2 */
77#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
78#define SSH2_MSG_DEBUG 4 /* 0x4 */
79#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
80#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
81#define SSH2_MSG_KEXINIT 20 /* 0x14 */
82#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
83#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
84#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
85#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
86#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
87#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
88#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
89#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 95#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
96#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 97#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
98#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
99#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
100#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
101#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
102#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
103#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
104#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
105#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
106#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
107#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
108#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
109#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
110#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
111
00db133f 112/*
113 * Packet type contexts, so that ssh2_pkt_type can correctly decode
114 * the ambiguous type numbers back into the correct type strings.
115 */
116#define SSH2_PKTCTX_DHGROUP1 0x0001
117#define SSH2_PKTCTX_DHGEX 0x0002
118#define SSH2_PKTCTX_PUBLICKEY 0x0010
119#define SSH2_PKTCTX_PASSWORD 0x0020
120#define SSH2_PKTCTX_KBDINTER 0x0040
121#define SSH2_PKTCTX_AUTH_MASK 0x00F0
122
32874aea 123#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
124#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
125#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
126#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
127#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
128#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
129#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
130#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
131#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
132#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
133#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
134#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
135#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
136#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
137#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 138
139static const char *const ssh2_disconnect_reasons[] = {
140 NULL,
141 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
142 "SSH_DISCONNECT_PROTOCOL_ERROR",
143 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
144 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
145 "SSH_DISCONNECT_MAC_ERROR",
146 "SSH_DISCONNECT_COMPRESSION_ERROR",
147 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
148 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
149 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
150 "SSH_DISCONNECT_CONNECTION_LOST",
151 "SSH_DISCONNECT_BY_APPLICATION",
152 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
153 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
154 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
155 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
156};
9005f3ba 157
32874aea 158#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
159#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
160#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
161#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 162
32874aea 163#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 164
7d503c31 165/*
166 * Various remote-bug flags.
167 */
168#define BUG_CHOKES_ON_SSH1_IGNORE 1
169#define BUG_SSH2_HMAC 2
bd358db1 170#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
171
00db133f 172static int ssh_pkt_ctx = 0;
173
174#define translate(x) if (type == x) return #x
175#define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
176char *ssh1_pkt_type(int type)
177{
178 translate(SSH1_MSG_DISCONNECT);
179 translate(SSH1_SMSG_PUBLIC_KEY);
180 translate(SSH1_CMSG_SESSION_KEY);
181 translate(SSH1_CMSG_USER);
182 translate(SSH1_CMSG_AUTH_RSA);
183 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
184 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
185 translate(SSH1_CMSG_AUTH_PASSWORD);
186 translate(SSH1_CMSG_REQUEST_PTY);
187 translate(SSH1_CMSG_WINDOW_SIZE);
188 translate(SSH1_CMSG_EXEC_SHELL);
189 translate(SSH1_CMSG_EXEC_CMD);
190 translate(SSH1_SMSG_SUCCESS);
191 translate(SSH1_SMSG_FAILURE);
192 translate(SSH1_CMSG_STDIN_DATA);
193 translate(SSH1_SMSG_STDOUT_DATA);
194 translate(SSH1_SMSG_STDERR_DATA);
195 translate(SSH1_CMSG_EOF);
196 translate(SSH1_SMSG_EXIT_STATUS);
197 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
198 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
199 translate(SSH1_MSG_CHANNEL_DATA);
200 translate(SSH1_MSG_CHANNEL_CLOSE);
201 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
202 translate(SSH1_SMSG_X11_OPEN);
203 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
204 translate(SSH1_MSG_PORT_OPEN);
205 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
206 translate(SSH1_SMSG_AGENT_OPEN);
207 translate(SSH1_MSG_IGNORE);
208 translate(SSH1_CMSG_EXIT_CONFIRMATION);
209 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
210 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
211 translate(SSH1_MSG_DEBUG);
212 translate(SSH1_CMSG_REQUEST_COMPRESSION);
213 translate(SSH1_CMSG_AUTH_TIS);
214 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
215 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
216 translate(SSH1_CMSG_AUTH_CCARD);
217 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
218 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
219 return "unknown";
220}
221char *ssh2_pkt_type(int type)
222{
223 translate(SSH2_MSG_DISCONNECT);
224 translate(SSH2_MSG_IGNORE);
225 translate(SSH2_MSG_UNIMPLEMENTED);
226 translate(SSH2_MSG_DEBUG);
227 translate(SSH2_MSG_SERVICE_REQUEST);
228 translate(SSH2_MSG_SERVICE_ACCEPT);
229 translate(SSH2_MSG_KEXINIT);
230 translate(SSH2_MSG_NEWKEYS);
231 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
232 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
233 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
234 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
235 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
236 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
237 translate(SSH2_MSG_USERAUTH_REQUEST);
238 translate(SSH2_MSG_USERAUTH_FAILURE);
239 translate(SSH2_MSG_USERAUTH_SUCCESS);
240 translate(SSH2_MSG_USERAUTH_BANNER);
241 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
242 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
243 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
244 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
245 translate(SSH2_MSG_GLOBAL_REQUEST);
246 translate(SSH2_MSG_REQUEST_SUCCESS);
247 translate(SSH2_MSG_REQUEST_FAILURE);
248 translate(SSH2_MSG_CHANNEL_OPEN);
249 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
250 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
251 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
252 translate(SSH2_MSG_CHANNEL_DATA);
253 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
254 translate(SSH2_MSG_CHANNEL_EOF);
255 translate(SSH2_MSG_CHANNEL_CLOSE);
256 translate(SSH2_MSG_CHANNEL_REQUEST);
257 translate(SSH2_MSG_CHANNEL_SUCCESS);
258 translate(SSH2_MSG_CHANNEL_FAILURE);
259 return "unknown";
260}
261#undef translate
262#undef translatec
7d503c31 263
fb09bf1c 264#define GET_32BIT(cp) \
265 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
266 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
267 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
268 ((unsigned long)(unsigned char)(cp)[3]))
269
270#define PUT_32BIT(cp, value) { \
271 (cp)[0] = (unsigned char)((value) >> 24); \
272 (cp)[1] = (unsigned char)((value) >> 16); \
273 (cp)[2] = (unsigned char)((value) >> 8); \
274 (cp)[3] = (unsigned char)(value); }
275
7cca0d81 276enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 277
374330e2 278/* Coroutine mechanics for the sillier bits of the code */
279#define crBegin1 static int crLine = 0;
280#define crBegin2 switch(crLine) { case 0:;
281#define crBegin crBegin1; crBegin2;
282#define crFinish(z) } crLine = 0; return (z)
283#define crFinishV } crLine = 0; return
284#define crReturn(z) \
285 do {\
286 crLine=__LINE__; return (z); case __LINE__:;\
287 } while (0)
288#define crReturnV \
289 do {\
290 crLine=__LINE__; return; case __LINE__:;\
291 } while (0)
292#define crStop(z) do{ crLine = 0; return (z); }while(0)
293#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 294#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 295#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 296
32874aea 297extern char *x11_init(Socket *, char *, void *);
298extern void x11_close(Socket);
5471d09a 299extern int x11_send(Socket, char *, int);
9c964e85 300extern void x11_invent_auth(char *, int, char *, int);
5471d09a 301extern void x11_unthrottle(Socket s);
302extern void x11_override_throttle(Socket s, int enable);
9c964e85 303
d74d141c 304extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
305extern char *pfd_addforward(char *desthost, int destport, int port);
306extern void pfd_close(Socket s);
5471d09a 307extern int pfd_send(Socket s, char *data, int len);
d74d141c 308extern void pfd_confirm(Socket s);
5471d09a 309extern void pfd_unthrottle(Socket s);
310extern void pfd_override_throttle(Socket s, int enable);
311
312/*
313 * Buffer management constants. There are several of these for
314 * various different purposes:
315 *
316 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
317 * on a local data stream before we throttle the whole SSH
318 * connection (in SSH1 only). Throttling the whole connection is
319 * pretty drastic so we set this high in the hope it won't
320 * happen very often.
321 *
322 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
323 * on the SSH connection itself before we defensively throttle
324 * _all_ local data streams. This is pretty drastic too (though
325 * thankfully unlikely in SSH2 since the window mechanism should
326 * ensure that the server never has any need to throttle its end
327 * of the connection), so we set this high as well.
328 *
329 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
330 * channels.
331 */
332
333#define SSH1_BUFFER_LIMIT 32768
334#define SSH_MAX_BACKLOG 32768
335#define OUR_V2_WINSIZE 16384
d74d141c 336
a92dd380 337const static struct ssh_kex *kex_algs[] = {
a92dd380 338 &ssh_diffiehellman_gex,
32874aea 339 &ssh_diffiehellman
340};
e5574168 341
85cc02bb 342const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 343
32874aea 344static void nullmac_key(unsigned char *key)
345{
346}
347static void nullmac_generate(unsigned char *blk, int len,
348 unsigned long seq)
349{
350}
351static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
352{
353 return 1;
354}
57476f6b 355const static struct ssh_mac ssh_mac_none = {
d39f364a 356 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 357};
8b2715b2 358const static struct ssh_mac *macs[] = {
32874aea 359 &ssh_sha1, &ssh_md5, &ssh_mac_none
360};
8b2715b2 361const static struct ssh_mac *buggymacs[] = {
32874aea 362 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
363};
e5574168 364
32874aea 365static void ssh_comp_none_init(void)
366{
367}
4ba9b64b 368static int ssh_comp_none_block(unsigned char *block, int len,
32874aea 369 unsigned char **outblock, int *outlen)
370{
371 return 0;
372}
373static int ssh_comp_none_disable(void)
374{
4ba9b64b 375 return 0;
376}
57476f6b 377const static struct ssh_compress ssh_comp_none = {
4ba9b64b 378 "none",
379 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 380 ssh_comp_none_init, ssh_comp_none_block,
381 ssh_comp_none_disable
e5574168 382};
4ba9b64b 383extern const struct ssh_compress ssh_zlib;
384const static struct ssh_compress *compressions[] = {
32874aea 385 &ssh_zlib, &ssh_comp_none
386};
374330e2 387
32874aea 388enum { /* channel types */
783415f8 389 CHAN_MAINSESSION,
390 CHAN_X11,
391 CHAN_AGENT,
bc240b21 392 CHAN_SOCKDATA,
393 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 394};
395
dacbd0e8 396/*
397 * 2-3-4 tree storing channels.
398 */
399struct ssh_channel {
d211621f 400 unsigned remoteid, localid;
dacbd0e8 401 int type;
402 int closes;
5471d09a 403 union {
404 struct ssh1_data_channel {
405 int throttling;
406 } v1;
407 struct ssh2_data_channel {
408 bufchain outbuffer;
409 unsigned remwindow, remmaxpkt;
410 unsigned locwindow;
411 } v2;
412 } v;
dacbd0e8 413 union {
32874aea 414 struct ssh_agent_channel {
415 unsigned char *message;
416 unsigned char msglen[4];
417 int lensofar, totallen;
418 } a;
419 struct ssh_x11_channel {
420 Socket s;
421 } x11;
d74d141c 422 struct ssh_pfd_channel {
423 Socket s;
424 } pfd;
dacbd0e8 425 } u;
426};
57476f6b 427
d74d141c 428/*
bc240b21 429 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
430 * 2 use this structure in different ways, reflecting SSH 2's
431 * altogether saner approach to port forwarding.
432 *
433 * In SSH 1, you arrange a remote forwarding by sending the server
434 * the remote port number, and the local destination host:port.
435 * When a connection comes in, the server sends you back that
436 * host:port pair, and you connect to it. This is a ready-made
437 * security hole if you're not on the ball: a malicious server
438 * could send you back _any_ host:port pair, so if you trustingly
439 * connect to the address it gives you then you've just opened the
440 * entire inside of your corporate network just by connecting
441 * through it to a dodgy SSH server. Hence, we must store a list of
442 * host:port pairs we _are_ trying to forward to, and reject a
443 * connection request from the server if it's not in the list.
444 *
445 * In SSH 2, each side of the connection minds its own business and
446 * doesn't send unnecessary information to the other. You arrange a
447 * remote forwarding by sending the server just the remote port
448 * number. When a connection comes in, the server tells you which
449 * of its ports was connected to; and _you_ have to remember what
450 * local host:port pair went with that port number.
451 *
452 * Hence: in SSH 1 this structure stores host:port pairs we intend
453 * to allow connections to, and is indexed by those host:port
454 * pairs. In SSH 2 it stores a mapping from source port to
455 * destination host:port pair, and is indexed by source port.
d74d141c 456 */
457struct ssh_rportfwd {
bc240b21 458 unsigned sport, dport;
459 char dhost[256];
d74d141c 460};
461
57476f6b 462struct Packet {
463 long length;
464 int type;
465 unsigned char *data;
466 unsigned char *body;
467 long savedpos;
468 long maxlen;
469};
470
0db56f73 471static SHA_State exhash, exhashbase;
57476f6b 472
8df7a775 473static Socket s = NULL;
57476f6b 474
475static unsigned char session_key[32];
4ba9b64b 476static int ssh1_compressing;
b96dc54c 477static int ssh1_remote_protoflags;
478static int ssh1_local_protoflags;
db7d555c 479static int ssh_agentfwd_enabled;
9c964e85 480static int ssh_X11_fwd_enabled;
7d503c31 481static int ssh_remote_bugs;
57476f6b 482static const struct ssh_cipher *cipher = NULL;
0a3f1d48 483static const struct ssh2_cipher *cscipher = NULL;
484static const struct ssh2_cipher *sccipher = NULL;
57476f6b 485static const struct ssh_mac *csmac = NULL;
486static const struct ssh_mac *scmac = NULL;
487static const struct ssh_compress *cscomp = NULL;
488static const struct ssh_compress *sccomp = NULL;
489static const struct ssh_kex *kex = NULL;
e055a386 490static const struct ssh_signkey *hostkey = NULL;
65a22376 491static unsigned char ssh2_session_id[20];
32874aea 492int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
493 int is_pw) = NULL;
57476f6b 494
495static char *savedhost;
496static int savedport;
497static int ssh_send_ok;
0965bee0 498static int ssh_echoing, ssh_editing;
57476f6b 499
32874aea 500static tree234 *ssh_channels; /* indexed by local id */
57476f6b 501static struct ssh_channel *mainchan; /* primary session channel */
d8d6c7e5 502static int ssh_exitcode = -1;
57476f6b 503
d74d141c 504static tree234 *ssh_rportfwds;
505
57476f6b 506static enum {
3687d221 507 SSH_STATE_PREPACKET,
57476f6b 508 SSH_STATE_BEFORE_SIZE,
509 SSH_STATE_INTERMED,
510 SSH_STATE_SESSION,
511 SSH_STATE_CLOSED
3687d221 512} ssh_state = SSH_STATE_PREPACKET;
57476f6b 513
3687d221 514static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 515
516static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
517static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 518static unsigned char *deferred_send_data = NULL;
519static int deferred_len = 0, deferred_size = 0;
57476f6b 520
fd5e5847 521/*
522 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
523 * that fails. This variable is the means by which scp.c can reach
524 * into the SSH code and find out which one it got.
525 */
526int ssh_fallback_cmd = 0;
527
57476f6b 528static int ssh_version;
5471d09a 529static int ssh1_throttle_count;
530static int ssh_overall_bufsize;
531static int ssh_throttled_all;
532static int ssh1_stdout_throttling;
32874aea 533static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
57476f6b 534static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
535static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
536static void ssh_size(void);
32874aea 537static void ssh_special(Telnet_Special);
5471d09a 538static int ssh2_try_send(struct ssh_channel *c);
32874aea 539static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
540 int len);
5471d09a 541static void ssh_throttle_all(int enable, int bufsize);
542static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
32874aea 543static int (*s_rdpkt) (unsigned char **data, int *datalen);
5471d09a 544static int ssh_sendbuffer(void);
57476f6b 545
546static struct rdpkt1_state_tag {
547 long len, pad, biglen, to_read;
548 unsigned long realcrc, gotcrc;
549 unsigned char *p;
550 int i;
551 int chunk;
552} rdpkt1_state;
553
960e736a 554static struct rdpkt2_state_tag {
555 long len, pad, payload, packetlen, maclen;
556 int i;
557 int cipherblk;
558 unsigned long incoming_sequence;
559} rdpkt2_state;
560
32874aea 561static int ssh_channelcmp(void *av, void *bv)
562{
563 struct ssh_channel *a = (struct ssh_channel *) av;
564 struct ssh_channel *b = (struct ssh_channel *) bv;
565 if (a->localid < b->localid)
566 return -1;
567 if (a->localid > b->localid)
568 return +1;
dacbd0e8 569 return 0;
570}
32874aea 571static int ssh_channelfind(void *av, void *bv)
572{
573 unsigned *a = (unsigned *) av;
574 struct ssh_channel *b = (struct ssh_channel *) bv;
575 if (*a < b->localid)
576 return -1;
577 if (*a > b->localid)
578 return +1;
dacbd0e8 579 return 0;
580}
581
bc240b21 582static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 583{
584 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
585 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
586 int i;
bc240b21 587 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 588 return i < 0 ? -1 : +1;
bc240b21 589 if (a->dport > b->dport)
590 return +1;
591 if (a->dport < b->dport)
592 return -1;
593 return 0;
594}
595
596static int ssh_rportcmp_ssh2(void *av, void *bv)
597{
598 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
599 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 600
bc240b21 601 if (a->sport > b->sport)
d74d141c 602 return +1;
bc240b21 603 if (a->sport < b->sport)
604 return -1;
d74d141c 605 return 0;
606}
607
32874aea 608static int alloc_channel_id(void)
609{
260f3dec 610 const unsigned CHANNEL_NUMBER_OFFSET = 256;
611 unsigned low, high, mid;
d2371c81 612 int tsize;
613 struct ssh_channel *c;
614
615 /*
616 * First-fit allocation of channel numbers: always pick the
617 * lowest unused one. To do this, binary-search using the
618 * counted B-tree to find the largest channel ID which is in a
619 * contiguous sequence from the beginning. (Precisely
620 * everything in that sequence must have ID equal to its tree
621 * index plus CHANNEL_NUMBER_OFFSET.)
622 */
623 tsize = count234(ssh_channels);
624
32874aea 625 low = -1;
626 high = tsize;
d2371c81 627 while (high - low > 1) {
628 mid = (high + low) / 2;
629 c = index234(ssh_channels, mid);
630 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
631 low = mid; /* this one is fine */
632 else
633 high = mid; /* this one is past it */
634 }
635 /*
636 * Now low points to either -1, or the tree index of the
637 * largest ID in the initial sequence.
638 */
639 {
640 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
641 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
642 }
643 return low + 1 + CHANNEL_NUMBER_OFFSET;
644}
645
32874aea 646static void c_write(char *buf, int len)
647{
67779be7 648 if ((flags & FLAG_STDERR)) {
32874aea 649 int i;
650 for (i = 0; i < len; i++)
651 if (buf[i] != '\r')
652 fputc(buf[i], stderr);
fb09bf1c 653 return;
654 }
fe50e814 655 from_backend(1, buf, len);
3bdaf79d 656}
657
32874aea 658static void c_write_untrusted(char *buf, int len)
659{
a209e957 660 int i;
661 for (i = 0; i < len; i++) {
32874aea 662 if (buf[i] == '\n')
663 c_write("\r\n", 2);
664 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
665 c_write(buf + i, 1);
a209e957 666 }
667}
668
32874aea 669static void c_write_str(char *buf)
670{
1408a877 671 c_write(buf, strlen(buf));
672}
673
fb09bf1c 674/*
675 * Collect incoming data in the incoming packet buffer.
e5574168 676 * Decipher and verify the packet when it is completely read.
677 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 678 * Update the *data and *datalen variables.
679 * Return the additional nr of bytes needed, or 0 when
680 * a complete packet is available.
681 */
e5574168 682static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 683{
57476f6b 684 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 685
686 crBegin;
374330e2 687
32874aea 688 next_packet:
37508af4 689
fb09bf1c 690 pktin.type = 0;
691 pktin.length = 0;
374330e2 692
57476f6b 693 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 694 while ((*datalen) == 0)
32874aea 695 crReturn(4 - st->i);
57476f6b 696 st->len = (st->len << 8) + **data;
fb09bf1c 697 (*data)++, (*datalen)--;
698 }
374330e2 699
57476f6b 700 st->pad = 8 - (st->len % 8);
701 st->biglen = st->len + st->pad;
702 pktin.length = st->len - 5;
fb09bf1c 703
57476f6b 704 if (pktin.maxlen < st->biglen) {
705 pktin.maxlen = st->biglen;
32874aea 706 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
707 srealloc(pktin.data, st->biglen + APIEXTRA));
fb09bf1c 708 if (!pktin.data)
709 fatalbox("Out of memory");
710 }
374330e2 711
57476f6b 712 st->to_read = st->biglen;
713 st->p = pktin.data;
714 while (st->to_read > 0) {
32874aea 715 st->chunk = st->to_read;
fb09bf1c 716 while ((*datalen) == 0)
57476f6b 717 crReturn(st->to_read);
718 if (st->chunk > (*datalen))
719 st->chunk = (*datalen);
720 memcpy(st->p, *data, st->chunk);
721 *data += st->chunk;
722 *datalen -= st->chunk;
723 st->p += st->chunk;
724 st->to_read -= st->chunk;
fb09bf1c 725 }
374330e2 726
fb09bf1c 727 if (cipher)
57476f6b 728 cipher->decrypt(pktin.data, st->biglen);
374330e2 729
32874aea 730 st->realcrc = crc32(pktin.data, st->biglen - 4);
731 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
57476f6b 732 if (st->gotcrc != st->realcrc) {
8d5de777 733 bombout(("Incorrect CRC received on packet"));
32874aea 734 crReturn(0);
fb09bf1c 735 }
572f871e 736
4ba9b64b 737 pktin.body = pktin.data + st->pad + 1;
738
739 if (ssh1_compressing) {
740 unsigned char *decompblk;
741 int decomplen;
32874aea 742 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
4ba9b64b 743 &decompblk, &decomplen);
744
745 if (pktin.maxlen < st->pad + decomplen) {
746 pktin.maxlen = st->pad + decomplen;
32874aea 747 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
748 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 749 if (!pktin.data)
750 fatalbox("Out of memory");
751 }
752
32874aea 753 memcpy(pktin.body - 1, decompblk, decomplen);
dcbde236 754 sfree(decompblk);
32874aea 755 pktin.length = decomplen - 1;
4ba9b64b 756 }
757
00db133f 758 pktin.type = pktin.body[-1];
759
760 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
761 pktin.body, pktin.length);
762
e5574168 763 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 764 pktin.type == SSH1_SMSG_STDERR_DATA ||
765 pktin.type == SSH1_MSG_DEBUG ||
766 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
767 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 768 long strlen = GET_32BIT(pktin.body);
8d5de777 769 if (strlen + 4 != pktin.length) {
770 bombout(("Received data packet with bogus string length"));
32874aea 771 crReturn(0);
772 }
fb09bf1c 773 }
774
e5574168 775 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 776 /* log debug message */
777 char buf[80];
778 int strlen = GET_32BIT(pktin.body);
779 strcpy(buf, "Remote: ");
32874aea 780 if (strlen > 70)
781 strlen = 70;
782 memcpy(buf + 8, pktin.body + 4, strlen);
783 buf[8 + strlen] = '\0';
fb09bf1c 784 logevent(buf);
785 goto next_packet;
e5574168 786 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 787 /* do nothing */
788 goto next_packet;
789 }
790
38c4a8da 791 if (pktin.type == SSH1_MSG_DISCONNECT) {
792 /* log reason code in disconnect message */
793 char buf[256];
260f3dec 794 unsigned msglen = GET_32BIT(pktin.body);
795 unsigned nowlen;
38c4a8da 796 strcpy(buf, "Remote sent disconnect: ");
797 nowlen = strlen(buf);
32874aea 798 if (msglen > sizeof(buf) - nowlen - 1)
799 msglen = sizeof(buf) - nowlen - 1;
800 memcpy(buf + nowlen, pktin.body + 4, msglen);
801 buf[nowlen + msglen] = '\0';
38c4a8da 802 logevent(buf);
4eb195cc 803 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 804 crReturn(0);
38c4a8da 805 }
806
fb09bf1c 807 crFinish(0);
808}
809
e5574168 810static int ssh2_rdpkt(unsigned char **data, int *datalen)
811{
960e736a 812 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 813
814 crBegin;
815
32874aea 816 next_packet:
e5574168 817 pktin.type = 0;
818 pktin.length = 0;
960e736a 819 if (sccipher)
32874aea 820 st->cipherblk = sccipher->blksize;
e5574168 821 else
32874aea 822 st->cipherblk = 8;
960e736a 823 if (st->cipherblk < 8)
32874aea 824 st->cipherblk = 8;
960e736a 825
826 if (pktin.maxlen < st->cipherblk) {
827 pktin.maxlen = st->cipherblk;
32874aea 828 pktin.data =
829 (pktin.data ==
830 NULL ? smalloc(st->cipherblk +
831 APIEXTRA) : srealloc(pktin.data,
832 st->cipherblk +
833 APIEXTRA));
e5574168 834 if (!pktin.data)
835 fatalbox("Out of memory");
836 }
837
838 /*
839 * Acquire and decrypt the first block of the packet. This will
840 * contain the length and padding details.
841 */
32874aea 842 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 843 while ((*datalen) == 0)
32874aea 844 crReturn(st->cipherblk - st->i);
960e736a 845 pktin.data[st->i] = *(*data)++;
32874aea 846 (*datalen)--;
e5574168 847 }
4252c9cc 848
e5574168 849 if (sccipher)
32874aea 850 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 851
852 /*
853 * Now get the length and padding figures.
854 */
960e736a 855 st->len = GET_32BIT(pktin.data);
856 st->pad = pktin.data[4];
e5574168 857
858 /*
859 * This enables us to deduce the payload length.
860 */
960e736a 861 st->payload = st->len - st->pad - 1;
e5574168 862
960e736a 863 pktin.length = st->payload + 5;
e5574168 864
865 /*
866 * So now we can work out the total packet length.
867 */
960e736a 868 st->packetlen = st->len + 4;
869 st->maclen = scmac ? scmac->len : 0;
e5574168 870
871 /*
872 * Adjust memory allocation if packet is too big.
873 */
32874aea 874 if (pktin.maxlen < st->packetlen + st->maclen) {
875 pktin.maxlen = st->packetlen + st->maclen;
876 pktin.data =
877 (pktin.data ==
878 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
879 pktin.maxlen
880 +
881 APIEXTRA));
e5574168 882 if (!pktin.data)
883 fatalbox("Out of memory");
884 }
885
886 /*
887 * Read and decrypt the remainder of the packet.
888 */
32874aea 889 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
890 st->i++) {
e5574168 891 while ((*datalen) == 0)
960e736a 892 crReturn(st->packetlen + st->maclen - st->i);
893 pktin.data[st->i] = *(*data)++;
32874aea 894 (*datalen)--;
e5574168 895 }
896 /* Decrypt everything _except_ the MAC. */
897 if (sccipher)
32874aea 898 sccipher->decrypt(pktin.data + st->cipherblk,
899 st->packetlen - st->cipherblk);
e5574168 900
901 /*
902 * Check the MAC.
903 */
32874aea 904 if (scmac
905 && !scmac->verify(pktin.data, st->len + 4,
906 st->incoming_sequence)) {
8d5de777 907 bombout(("Incorrect MAC received on packet"));
32874aea 908 crReturn(0);
8d5de777 909 }
32874aea 910 st->incoming_sequence++; /* whether or not we MACed */
e5574168 911
4ba9b64b 912 /*
913 * Decompress packet payload.
914 */
915 {
916 unsigned char *newpayload;
917 int newlen;
32874aea 918 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
4ba9b64b 919 &newpayload, &newlen)) {
32874aea 920 if (pktin.maxlen < newlen + 5) {
921 pktin.maxlen = newlen + 5;
922 pktin.data =
923 (pktin.data ==
924 NULL ? smalloc(pktin.maxlen +
925 APIEXTRA) : srealloc(pktin.data,
926 pktin.maxlen +
927 APIEXTRA));
4ba9b64b 928 if (!pktin.data)
929 fatalbox("Out of memory");
930 }
931 pktin.length = 5 + newlen;
32874aea 932 memcpy(pktin.data + 5, newpayload, newlen);
dcbde236 933 sfree(newpayload);
4ba9b64b 934 }
935 }
936
e5574168 937 pktin.savedpos = 6;
938 pktin.type = pktin.data[5];
e5574168 939
00db133f 940 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
941 pktin.data+6, pktin.length-6);
942
7cca0d81 943 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
32874aea 944 goto next_packet; /* FIXME: print DEBUG message */
e5574168 945
38c4a8da 946 if (pktin.type == SSH2_MSG_DISCONNECT) {
947 /* log reason code in disconnect message */
948 char buf[256];
32874aea 949 int reason = GET_32BIT(pktin.data + 6);
950 unsigned msglen = GET_32BIT(pktin.data + 10);
260f3dec 951 unsigned nowlen;
38c4a8da 952 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
953 sprintf(buf, "Received disconnect message (%s)",
954 ssh2_disconnect_reasons[reason]);
955 } else {
32874aea 956 sprintf(buf, "Received disconnect message (unknown type %d)",
957 reason);
38c4a8da 958 }
959 logevent(buf);
960 strcpy(buf, "Disconnection message text: ");
961 nowlen = strlen(buf);
32874aea 962 if (msglen > sizeof(buf) - nowlen - 1)
963 msglen = sizeof(buf) - nowlen - 1;
964 memcpy(buf + nowlen, pktin.data + 14, msglen);
965 buf[nowlen + msglen] = '\0';
38c4a8da 966 logevent(buf);
4eb195cc 967 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
968 reason,
969 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
970 ssh2_disconnect_reasons[reason] : "unknown",
971 buf+nowlen));
e14d0f19 972 crReturn(0);
38c4a8da 973 }
974
e5574168 975 crFinish(0);
976}
977
32874aea 978static void ssh1_pktout_size(int len)
979{
374330e2 980 int pad, biglen;
981
982 len += 5; /* type and CRC */
32874aea 983 pad = 8 - (len % 8);
374330e2 984 biglen = len + pad;
985
32874aea 986 pktout.length = len - 5;
374330e2 987 if (pktout.maxlen < biglen) {
988 pktout.maxlen = biglen;
8f203108 989#ifdef MSCRYPTOAPI
fb09bf1c 990 /* Allocate enough buffer space for extra block
8f203108 991 * for MS CryptEncrypt() */
32874aea 992 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
993 srealloc(pktout.data, biglen + 12));
8f203108 994#else
32874aea 995 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
996 srealloc(pktout.data, biglen + 4));
8f203108 997#endif
374330e2 998 if (!pktout.data)
999 fatalbox("Out of memory");
1000 }
32874aea 1001 pktout.body = pktout.data + 4 + pad + 1;
4ba9b64b 1002}
374330e2 1003
32874aea 1004static void s_wrpkt_start(int type, int len)
1005{
4ba9b64b 1006 ssh1_pktout_size(len);
374330e2 1007 pktout.type = type;
374330e2 1008}
1009
32874aea 1010static int s_wrpkt_prepare(void)
1011{
374330e2 1012 int pad, len, biglen, i;
1013 unsigned long crc;
1014
4ba9b64b 1015 pktout.body[-1] = pktout.type;
1016
00db133f 1017 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1018 pktout.body, pktout.length);
1019
4ba9b64b 1020 if (ssh1_compressing) {
1021 unsigned char *compblk;
1022 int complen;
32874aea 1023 zlib_compress_block(pktout.body - 1, pktout.length + 1,
4ba9b64b 1024 &compblk, &complen);
32874aea 1025 ssh1_pktout_size(complen - 1);
1026 memcpy(pktout.body - 1, compblk, complen);
dcbde236 1027 sfree(compblk);
4ba9b64b 1028 }
1029
374330e2 1030 len = pktout.length + 5; /* type and CRC */
32874aea 1031 pad = 8 - (len % 8);
374330e2 1032 biglen = len + pad;
1033
32874aea 1034 for (i = 0; i < pad; i++)
1035 pktout.data[i + 4] = random_byte();
1036 crc = crc32(pktout.data + 4, biglen - 4);
1037 PUT_32BIT(pktout.data + biglen, crc);
fb09bf1c 1038 PUT_32BIT(pktout.data, len);
374330e2 1039
1040 if (cipher)
32874aea 1041 cipher->encrypt(pktout.data + 4, biglen);
374330e2 1042
32874aea 1043 return biglen + 4;
39065bed 1044}
1045
32874aea 1046static void s_wrpkt(void)
1047{
5471d09a 1048 int len, backlog;
39065bed 1049 len = s_wrpkt_prepare();
5471d09a 1050 backlog = sk_write(s, pktout.data, len);
1051 if (backlog > SSH_MAX_BACKLOG)
1052 ssh_throttle_all(1, backlog);
39065bed 1053}
1054
32874aea 1055static void s_wrpkt_defer(void)
1056{
39065bed 1057 int len;
1058 len = s_wrpkt_prepare();
1059 if (deferred_len + len > deferred_size) {
32874aea 1060 deferred_size = deferred_len + len + 128;
1061 deferred_send_data = srealloc(deferred_send_data, deferred_size);
39065bed 1062 }
32874aea 1063 memcpy(deferred_send_data + deferred_len, pktout.data, len);
39065bed 1064 deferred_len += len;
374330e2 1065}
1066
fb09bf1c 1067/*
39065bed 1068 * Construct a packet with the specified contents.
fb09bf1c 1069 */
39065bed 1070static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1071{
fb09bf1c 1072 unsigned char *p, *argp, argchar;
1073 unsigned long argint;
1074 int pktlen, argtype, arglen;
7cca0d81 1075 Bignum bn;
fb09bf1c 1076
1077 pktlen = 0;
39065bed 1078 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1079 switch (argtype) {
1080 case PKT_INT:
39065bed 1081 (void) va_arg(ap1, int);
fb09bf1c 1082 pktlen += 4;
1083 break;
1084 case PKT_CHAR:
39065bed 1085 (void) va_arg(ap1, char);
fb09bf1c 1086 pktlen++;
1087 break;
1088 case PKT_DATA:
39065bed 1089 (void) va_arg(ap1, unsigned char *);
1090 arglen = va_arg(ap1, int);
fb09bf1c 1091 pktlen += arglen;
1092 break;
1093 case PKT_STR:
39065bed 1094 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1095 arglen = strlen(argp);
1096 pktlen += 4 + arglen;
1097 break;
7cca0d81 1098 case PKT_BIGNUM:
39065bed 1099 bn = va_arg(ap1, Bignum);
32874aea 1100 pktlen += ssh1_bignum_length(bn);
7cca0d81 1101 break;
fb09bf1c 1102 default:
1103 assert(0);
1104 }
1105 }
fb09bf1c 1106
1107 s_wrpkt_start(pkttype, pktlen);
1108 p = pktout.body;
1109
39065bed 1110 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1111 switch (argtype) {
1112 case PKT_INT:
39065bed 1113 argint = va_arg(ap2, int);
fb09bf1c 1114 PUT_32BIT(p, argint);
1115 p += 4;
1116 break;
1117 case PKT_CHAR:
39065bed 1118 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1119 *p = argchar;
1120 p++;
1121 break;
1122 case PKT_DATA:
39065bed 1123 argp = va_arg(ap2, unsigned char *);
1124 arglen = va_arg(ap2, int);
fb09bf1c 1125 memcpy(p, argp, arglen);
1126 p += arglen;
1127 break;
1128 case PKT_STR:
39065bed 1129 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1130 arglen = strlen(argp);
1131 PUT_32BIT(p, arglen);
1132 memcpy(p + 4, argp, arglen);
1133 p += 4 + arglen;
1134 break;
7cca0d81 1135 case PKT_BIGNUM:
39065bed 1136 bn = va_arg(ap2, Bignum);
32874aea 1137 p += ssh1_write_bignum(p, bn);
7cca0d81 1138 break;
fb09bf1c 1139 }
1140 }
39065bed 1141}
fb09bf1c 1142
32874aea 1143static void send_packet(int pkttype, ...)
1144{
39065bed 1145 va_list ap1, ap2;
1146 va_start(ap1, pkttype);
1147 va_start(ap2, pkttype);
1148 construct_packet(pkttype, ap1, ap2);
fb09bf1c 1149 s_wrpkt();
1150}
1151
32874aea 1152static void defer_packet(int pkttype, ...)
1153{
39065bed 1154 va_list ap1, ap2;
1155 va_start(ap1, pkttype);
1156 va_start(ap2, pkttype);
1157 construct_packet(pkttype, ap1, ap2);
1158 s_wrpkt_defer();
1159}
1160
32874aea 1161static int ssh_versioncmp(char *a, char *b)
1162{
9697bfd2 1163 char *ae, *be;
1164 unsigned long av, bv;
1165
43aa02a7 1166 av = strtoul(a, &ae, 10);
1167 bv = strtoul(b, &be, 10);
32874aea 1168 if (av != bv)
1169 return (av < bv ? -1 : +1);
1170 if (*ae == '.')
1171 ae++;
1172 if (*be == '.')
1173 be++;
43aa02a7 1174 av = strtoul(ae, &ae, 10);
1175 bv = strtoul(be, &be, 10);
32874aea 1176 if (av != bv)
1177 return (av < bv ? -1 : +1);
9697bfd2 1178 return 0;
1179}
1180
e5574168 1181
1182/*
a92dd380 1183 * Utility routines for putting an SSH-protocol `string' and
1184 * `uint32' into a SHA state.
e5574168 1185 */
1186#include <stdio.h>
32874aea 1187static void sha_string(SHA_State * s, void *str, int len)
1188{
e5574168 1189 unsigned char lenblk[4];
e5574168 1190 PUT_32BIT(lenblk, len);
e5574168 1191 SHA_Bytes(s, lenblk, 4);
e5574168 1192 SHA_Bytes(s, str, len);
1193}
1194
32874aea 1195static void sha_uint32(SHA_State * s, unsigned i)
1196{
a92dd380 1197 unsigned char intblk[4];
1198 PUT_32BIT(intblk, i);
1199 SHA_Bytes(s, intblk, 4);
1200}
1201
7cca0d81 1202/*
1203 * SSH2 packet construction functions.
1204 */
32874aea 1205static void ssh2_pkt_ensure(int length)
1206{
783415f8 1207 if (pktout.maxlen < length) {
32874aea 1208 pktout.maxlen = length + 256;
1209 pktout.data =
1210 (pktout.data ==
1211 NULL ? smalloc(pktout.maxlen +
1212 APIEXTRA) : srealloc(pktout.data,
1213 pktout.maxlen +
1214 APIEXTRA));
1215 if (!pktout.data)
1216 fatalbox("Out of memory");
7cca0d81 1217 }
783415f8 1218}
32874aea 1219static void ssh2_pkt_adddata(void *data, int len)
1220{
783415f8 1221 pktout.length += len;
1222 ssh2_pkt_ensure(pktout.length);
32874aea 1223 memcpy(pktout.data + pktout.length - len, data, len);
7cca0d81 1224}
32874aea 1225static void ssh2_pkt_addbyte(unsigned char byte)
1226{
7cca0d81 1227 ssh2_pkt_adddata(&byte, 1);
1228}
32874aea 1229static void ssh2_pkt_init(int pkt_type)
1230{
7cca0d81 1231 pktout.length = 5;
32874aea 1232 ssh2_pkt_addbyte((unsigned char) pkt_type);
7cca0d81 1233}
32874aea 1234static void ssh2_pkt_addbool(unsigned char value)
1235{
7cca0d81 1236 ssh2_pkt_adddata(&value, 1);
1237}
32874aea 1238static void ssh2_pkt_adduint32(unsigned long value)
1239{
7cca0d81 1240 unsigned char x[4];
1241 PUT_32BIT(x, value);
1242 ssh2_pkt_adddata(x, 4);
1243}
32874aea 1244static void ssh2_pkt_addstring_start(void)
1245{
7cca0d81 1246 ssh2_pkt_adduint32(0);
1247 pktout.savedpos = pktout.length;
1248}
32874aea 1249static void ssh2_pkt_addstring_str(char *data)
1250{
7cca0d81 1251 ssh2_pkt_adddata(data, strlen(data));
1252 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1253 pktout.length - pktout.savedpos);
7cca0d81 1254}
32874aea 1255static void ssh2_pkt_addstring_data(char *data, int len)
1256{
7cca0d81 1257 ssh2_pkt_adddata(data, len);
1258 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1259 pktout.length - pktout.savedpos);
7cca0d81 1260}
32874aea 1261static void ssh2_pkt_addstring(char *data)
1262{
7cca0d81 1263 ssh2_pkt_addstring_start();
1264 ssh2_pkt_addstring_str(data);
1265}
32874aea 1266static char *ssh2_mpint_fmt(Bignum b, int *len)
1267{
7cca0d81 1268 unsigned char *p;
32874aea 1269 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1270 p = smalloc(n + 1);
7cca0d81 1271 if (!p)
32874aea 1272 fatalbox("out of memory");
7cca0d81 1273 p[0] = 0;
3709bfe9 1274 for (i = 1; i <= n; i++)
32874aea 1275 p[i] = bignum_byte(b, n - i);
7cca0d81 1276 i = 0;
32874aea 1277 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1278 i++;
1279 memmove(p, p + i, n + 1 - i);
1280 *len = n + 1 - i;
7cca0d81 1281 return p;
1282}
32874aea 1283static void ssh2_pkt_addmp(Bignum b)
1284{
7cca0d81 1285 unsigned char *p;
1286 int len;
1287 p = ssh2_mpint_fmt(b, &len);
1288 ssh2_pkt_addstring_start();
1289 ssh2_pkt_addstring_data(p, len);
dcbde236 1290 sfree(p);
7cca0d81 1291}
b185170a 1292
1293/*
1294 * Construct an SSH2 final-form packet: compress it, encrypt it,
1295 * put the MAC on it. Final packet, ready to be sent, is stored in
1296 * pktout.data. Total length is returned.
1297 */
32874aea 1298static int ssh2_pkt_construct(void)
1299{
7cca0d81 1300 int cipherblk, maclen, padding, i;
1301 static unsigned long outgoing_sequence = 0;
1302
00db133f 1303 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1304 pktout.data + 6, pktout.length - 6);
1305
7cca0d81 1306 /*
4ba9b64b 1307 * Compress packet payload.
1308 */
4ba9b64b 1309 {
1310 unsigned char *newpayload;
1311 int newlen;
32874aea 1312 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
4ba9b64b 1313 &newpayload, &newlen)) {
1314 pktout.length = 5;
1315 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1316 sfree(newpayload);
4ba9b64b 1317 }
1318 }
1319
1320 /*
7cca0d81 1321 * Add padding. At least four bytes, and must also bring total
1322 * length (minus MAC) up to a multiple of the block size.
1323 */
32874aea 1324 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1325 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1326 padding = 4;
32874aea 1327 padding +=
1328 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1329 maclen = csmac ? csmac->len : 0;
1330 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1331 pktout.data[4] = padding;
1332 for (i = 0; i < padding; i++)
32874aea 1333 pktout.data[pktout.length + i] = random_byte();
7cca0d81 1334 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1335 if (csmac)
32874aea 1336 csmac->generate(pktout.data, pktout.length + padding,
1337 outgoing_sequence);
1338 outgoing_sequence++; /* whether or not we MACed */
7cca0d81 1339
7cca0d81 1340 if (cscipher)
32874aea 1341 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1342
b185170a 1343 /* Ready-to-send packet starts at pktout.data. We return length. */
1344 return pktout.length + padding + maclen;
1345}
1346
1347/*
1348 * Construct and send an SSH2 packet immediately.
1349 */
32874aea 1350static void ssh2_pkt_send(void)
1351{
5471d09a 1352 int len;
1353 int backlog;
1354 len = ssh2_pkt_construct();
1355 backlog = sk_write(s, pktout.data, len);
1356 if (backlog > SSH_MAX_BACKLOG)
1357 ssh_throttle_all(1, backlog);
b185170a 1358}
1359
1360/*
1361 * Construct an SSH2 packet and add it to a deferred data block.
1362 * Useful for sending multiple packets in a single sk_write() call,
1363 * to prevent a traffic-analysing listener from being able to work
1364 * out the length of any particular packet (such as the password
1365 * packet).
1366 *
1367 * Note that because SSH2 sequence-numbers its packets, this can
1368 * NOT be used as an m4-style `defer' allowing packets to be
1369 * constructed in one order and sent in another.
1370 */
32874aea 1371static void ssh2_pkt_defer(void)
1372{
b185170a 1373 int len = ssh2_pkt_construct();
1374 if (deferred_len + len > deferred_size) {
32874aea 1375 deferred_size = deferred_len + len + 128;
1376 deferred_send_data = srealloc(deferred_send_data, deferred_size);
b185170a 1377 }
32874aea 1378 memcpy(deferred_send_data + deferred_len, pktout.data, len);
b185170a 1379 deferred_len += len;
1380}
1381
1382/*
1383 * Send the whole deferred data block constructed by
39065bed 1384 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1385 */
32874aea 1386static void ssh_pkt_defersend(void)
1387{
5471d09a 1388 int backlog;
1389 backlog = sk_write(s, deferred_send_data, deferred_len);
b185170a 1390 deferred_len = deferred_size = 0;
1391 sfree(deferred_send_data);
1392 deferred_send_data = NULL;
5471d09a 1393 if (backlog > SSH_MAX_BACKLOG)
1394 ssh_throttle_all(1, backlog);
7cca0d81 1395}
1396
1397#if 0
32874aea 1398void bndebug(char *string, Bignum b)
1399{
7cca0d81 1400 unsigned char *p;
1401 int i, len;
1402 p = ssh2_mpint_fmt(b, &len);
1403 debug(("%s", string));
1404 for (i = 0; i < len; i++)
32874aea 1405 debug((" %02x", p[i]));
765c4200 1406 debug(("\n"));
dcbde236 1407 sfree(p);
7cca0d81 1408}
1409#endif
1410
32874aea 1411static void sha_mpint(SHA_State * s, Bignum b)
1412{
7cca0d81 1413 unsigned char *p;
1414 int len;
1415 p = ssh2_mpint_fmt(b, &len);
1416 sha_string(s, p, len);
dcbde236 1417 sfree(p);
7cca0d81 1418}
1419
1420/*
1421 * SSH2 packet decode functions.
1422 */
32874aea 1423static unsigned long ssh2_pkt_getuint32(void)
1424{
7cca0d81 1425 unsigned long value;
1426 if (pktin.length - pktin.savedpos < 4)
32874aea 1427 return 0; /* arrgh, no way to decline (FIXME?) */
1428 value = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1429 pktin.savedpos += 4;
1430 return value;
1431}
32874aea 1432static int ssh2_pkt_getbool(void)
1433{
65a22376 1434 unsigned long value;
1435 if (pktin.length - pktin.savedpos < 1)
32874aea 1436 return 0; /* arrgh, no way to decline (FIXME?) */
65a22376 1437 value = pktin.data[pktin.savedpos] != 0;
1438 pktin.savedpos++;
1439 return value;
1440}
32874aea 1441static void ssh2_pkt_getstring(char **p, int *length)
1442{
7cca0d81 1443 *p = NULL;
1444 if (pktin.length - pktin.savedpos < 4)
32874aea 1445 return;
1446 *length = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1447 pktin.savedpos += 4;
1448 if (pktin.length - pktin.savedpos < *length)
32874aea 1449 return;
1450 *p = pktin.data + pktin.savedpos;
7cca0d81 1451 pktin.savedpos += *length;
1452}
32874aea 1453static Bignum ssh2_pkt_getmp(void)
1454{
7cca0d81 1455 char *p;
3709bfe9 1456 int length;
7cca0d81 1457 Bignum b;
1458
1459 ssh2_pkt_getstring(&p, &length);
1460 if (!p)
32874aea 1461 return NULL;
8d5de777 1462 if (p[0] & 0x80) {
32874aea 1463 bombout(("internal error: Can't handle negative mpints"));
1464 return NULL;
8d5de777 1465 }
3709bfe9 1466 b = bignum_from_bytes(p, length);
7cca0d81 1467 return b;
1468}
1469
7d503c31 1470/*
1471 * Examine the remote side's version string and compare it against
1472 * a list of known buggy implementations.
1473 */
32874aea 1474static void ssh_detect_bugs(char *vstring)
1475{
1476 char *imp; /* pointer to implementation part */
7d503c31 1477 imp = vstring;
1478 imp += strcspn(imp, "-");
bd358db1 1479 if (*imp) imp++;
7d503c31 1480 imp += strcspn(imp, "-");
bd358db1 1481 if (*imp) imp++;
7d503c31 1482
1483 ssh_remote_bugs = 0;
1484
1485 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
32874aea 1486 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
bd358db1 1487 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
32874aea 1488 /*
1489 * These versions don't support SSH1_MSG_IGNORE, so we have
1490 * to use a different defence against password length
1491 * sniffing.
1492 */
1493 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1494 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1495 }
1496
bd358db1 1497 if (!strcmp(imp, "Cisco-1.25")) {
1498 /*
1499 * These versions need a plain password sent; they can't
1500 * handle having a null and a random length of data after
1501 * the password.
1502 */
1503 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1504 logevent("We believe remote version needs a plain SSH1 password");
1505 }
1506
7d503c31 1507 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
32874aea 1508 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1509 !strncmp(imp, "2.1 ", 4)) {
1510 /*
1511 * These versions have the HMAC bug.
1512 */
1513 ssh_remote_bugs |= BUG_SSH2_HMAC;
1514 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1515 }
1516}
1517
32874aea 1518static int do_ssh_init(unsigned char c)
1519{
2d466ffd 1520 static int vslen;
8df7a775 1521 static char version[10];
50526e47 1522 static char *vstring;
1523 static int vstrsize;
1524 static char *vlog;
8df7a775 1525 static int i;
374330e2 1526
8df7a775 1527 crBegin;
1528
1529 /* Search for the string "SSH-" in the input. */
374330e2 1530 i = 0;
8df7a775 1531 while (1) {
1532 static const int transS[] = { 1, 2, 2, 1 };
1533 static const int transH[] = { 0, 0, 3, 0 };
1534 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1535 if (c == 'S')
1536 i = transS[i];
1537 else if (c == 'H')
1538 i = transH[i];
1539 else if (c == '-')
1540 i = transminus[i];
1541 else
1542 i = 0;
8df7a775 1543 if (i < 0)
1544 break;
1545 crReturn(1); /* get another character */
374330e2 1546 }
8df7a775 1547
50526e47 1548 vstrsize = 16;
bd358db1 1549 vstring = smalloc(vstrsize);
c5e9c988 1550 strcpy(vstring, "SSH-");
50526e47 1551 vslen = 4;
374330e2 1552 i = 0;
1553 while (1) {
8df7a775 1554 crReturn(1); /* get another char */
32874aea 1555 if (vslen >= vstrsize - 1) {
1556 vstrsize += 16;
1557 vstring = srealloc(vstring, vstrsize);
1558 }
1559 vstring[vslen++] = c;
374330e2 1560 if (i >= 0) {
1561 if (c == '-') {
1562 version[i] = '\0';
1563 i = -1;
32874aea 1564 } else if (i < sizeof(version) - 1)
374330e2 1565 version[i++] = c;
32874aea 1566 } else if (c == '\n')
374330e2 1567 break;
1568 }
1569
db7d555c 1570 ssh_agentfwd_enabled = FALSE;
960e736a 1571 rdpkt2_state.incoming_sequence = 0;
1572
50526e47 1573 vstring[vslen] = 0;
9275ca8a 1574 vlog = smalloc(20 + vslen);
bd358db1 1575 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
c5e9c988 1576 sprintf(vlog, "Server version: %s", vstring);
c5e9c988 1577 logevent(vlog);
bd358db1 1578 ssh_detect_bugs(vstring);
9275ca8a 1579 sfree(vlog);
c5e9c988 1580
adf799dd 1581 /*
1582 * Server version "1.99" means we can choose whether we use v1
1583 * or v2 protocol. Choice is based on cfg.sshprot.
1584 */
1585 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
32874aea 1586 /*
1587 * This is a v2 server. Begin v2 protocol.
1588 */
1589 char verstring[80], vlog[100];
1590 sprintf(verstring, "SSH-2.0-%s", sshver);
1591 SHA_Init(&exhashbase);
1592 /*
1593 * Hash our version string and their version string.
1594 */
1595 sha_string(&exhashbase, verstring, strlen(verstring));
1596 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1597 sprintf(vlog, "We claim version: %s", verstring);
1598 logevent(vlog);
1599 strcat(verstring, "\n");
1600 logevent("Using SSH protocol version 2");
1601 sk_write(s, verstring, strlen(verstring));
1602 ssh_protocol = ssh2_protocol;
1603 ssh_version = 2;
1604 s_rdpkt = ssh2_rdpkt;
e5574168 1605 } else {
32874aea 1606 /*
1607 * This is a v1 server. Begin v1 protocol.
1608 */
1609 char verstring[80], vlog[100];
1610 sprintf(verstring, "SSH-%s-%s",
1611 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1612 sshver);
1613 sprintf(vlog, "We claim version: %s", verstring);
1614 logevent(vlog);
1615 strcat(verstring, "\n");
1616 logevent("Using SSH protocol version 1");
1617 sk_write(s, verstring, strlen(verstring));
1618 ssh_protocol = ssh1_protocol;
1619 ssh_version = 1;
1620 s_rdpkt = ssh1_rdpkt;
e5574168 1621 }
3687d221 1622 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1623
50526e47 1624 sfree(vstring);
50526e47 1625
8df7a775 1626 crFinish(0);
1627}
1628
1629static void ssh_gotdata(unsigned char *data, int datalen)
1630{
1631 crBegin;
1632
1633 /*
1634 * To begin with, feed the characters one by one to the
1635 * protocol initialisation / selection function do_ssh_init().
1636 * When that returns 0, we're done with the initial greeting
1637 * exchange and can move on to packet discipline.
1638 */
1639 while (1) {
1640 int ret;
1641 if (datalen == 0)
1642 crReturnV; /* more data please */
1643 ret = do_ssh_init(*data);
32874aea 1644 data++;
1645 datalen--;
8df7a775 1646 if (ret == 0)
1647 break;
1648 }
1649
1650 /*
1651 * We emerge from that loop when the initial negotiation is
1652 * over and we have selected an s_rdpkt function. Now pass
1653 * everything to s_rdpkt, and then pass the resulting packets
1654 * to the proper protocol handler.
1655 */
1656 if (datalen == 0)
1657 crReturnV;
1658 while (1) {
1659 while (datalen > 0) {
32874aea 1660 if (s_rdpkt(&data, &datalen) == 0) {
e14d0f19 1661 if (ssh_state == SSH_STATE_CLOSED) {
1662 return;
1663 }
8df7a775 1664 ssh_protocol(NULL, 0, 1);
1665 if (ssh_state == SSH_STATE_CLOSED) {
1666 return;
1667 }
1668 }
1669 }
1670 crReturnV;
1671 }
1672 crFinishV;
1673}
1674
32874aea 1675static int ssh_closing(Plug plug, char *error_msg, int error_code,
1676 int calling_back)
1677{
7e78000d 1678 ssh_state = SSH_STATE_CLOSED;
f3ab576e 1679 if (s) {
1680 sk_close(s);
1681 s = NULL;
1682 }
7e78000d 1683 if (error_msg) {
32874aea 1684 /* A socket error has occurred. */
1685 connection_fatal(error_msg);
7e78000d 1686 } else {
1687 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1688 }
7e78000d 1689 return 0;
1690}
1691
32874aea 1692static int ssh_receive(Plug plug, int urgent, char *data, int len)
1693{
1694 ssh_gotdata(data, len);
3257deae 1695 if (ssh_state == SSH_STATE_CLOSED) {
32874aea 1696 if (s) {
1697 sk_close(s);
1698 s = NULL;
1699 }
1700 return 0;
3257deae 1701 }
fef97f43 1702 return 1;
374330e2 1703}
1704
5471d09a 1705static void ssh_sent(Plug plug, int bufsize)
1706{
1707 /*
1708 * If the send backlog on the SSH socket itself clears, we
1709 * should unthrottle the whole world if it was throttled.
1710 */
1711 if (bufsize < SSH_MAX_BACKLOG)
1712 ssh_throttle_all(0, bufsize);
1713}
1714
fb09bf1c 1715/*
8df7a775 1716 * Connect to specified host and port.
1717 * Returns an error message, or NULL on success.
6e1ebb76 1718 * Also places the canonical host name into `realhost'. It must be
1719 * freed by the caller.
8df7a775 1720 */
2184a5d9 1721static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
8df7a775 1722{
7e78000d 1723 static struct plug_function_table fn_table = {
1724 ssh_closing,
5471d09a 1725 ssh_receive,
1726 ssh_sent,
1727 NULL
7e78000d 1728 }, *fn_table_ptr = &fn_table;
1729
8df7a775 1730 SockAddr addr;
1731 char *err;
1732#ifdef FWHACK
1733 char *FWhost;
1734 int FWport;
1735#endif
1736
32874aea 1737 savedhost = smalloc(1 + strlen(host));
8df7a775 1738 if (!savedhost)
1739 fatalbox("Out of memory");
1740 strcpy(savedhost, host);
1741
1742 if (port < 0)
1743 port = 22; /* default ssh port */
1744 savedport = port;
1745
1746#ifdef FWHACK
1747 FWhost = host;
1748 FWport = port;
1749 host = FWSTR;
1750 port = 23;
1751#endif
1752
1753 /*
1754 * Try to find host.
1755 */
3ad9d396 1756 {
1757 char buf[200];
1758 sprintf(buf, "Looking up host \"%.170s\"", host);
1759 logevent(buf);
1760 }
8df7a775 1761 addr = sk_namelookup(host, realhost);
32874aea 1762 if ((err = sk_addr_error(addr)))
8df7a775 1763 return err;
1764
1765#ifdef FWHACK
6e1ebb76 1766 *realhost = strdup(FWhost);
8df7a775 1767#endif
1768
1769 /*
1770 * Open socket.
1771 */
3ad9d396 1772 {
1773 char buf[200], addrbuf[100];
1774 sk_getaddr(addr, addrbuf, 100);
1775 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1776 logevent(buf);
1777 }
2184a5d9 1778 s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr);
32874aea 1779 if ((err = sk_socket_error(s)))
8df7a775 1780 return err;
1781
1782#ifdef FWHACK
1783 sk_write(s, "connect ", 8);
1784 sk_write(s, FWhost, strlen(FWhost));
1785 {
1786 char buf[20];
1787 sprintf(buf, " %d\n", FWport);
1788 sk_write(s, buf, strlen(buf));
1789 }
1790#endif
1791
1792 return NULL;
1793}
1794
1795/*
5471d09a 1796 * Throttle or unthrottle the SSH connection.
1797 */
1798static void ssh1_throttle(int adjust)
1799{
1800 int old_count = ssh1_throttle_count;
1801 ssh1_throttle_count += adjust;
1802 assert(ssh1_throttle_count >= 0);
1803 if (ssh1_throttle_count && !old_count) {
1804 sk_set_frozen(s, 1);
1805 } else if (!ssh1_throttle_count && old_count) {
1806 sk_set_frozen(s, 0);
1807 }
1808}
1809
1810/*
1811 * Throttle or unthrottle _all_ local data streams (for when sends
1812 * on the SSH connection itself back up).
1813 */
1814static void ssh_throttle_all(int enable, int bufsize)
1815{
1816 int i;
1817 struct ssh_channel *c;
1818
1819 if (enable == ssh_throttled_all)
1820 return;
1821 ssh_throttled_all = enable;
1822 ssh_overall_bufsize = bufsize;
1823 if (!ssh_channels)
1824 return;
1825 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
1826 switch (c->type) {
1827 case CHAN_MAINSESSION:
1828 /*
1829 * This is treated separately, outside the switch.
1830 */
1831 break;
1832 case CHAN_X11:
1833 x11_override_throttle(c->u.x11.s, enable);
1834 break;
1835 case CHAN_AGENT:
1836 /* Agent channels require no buffer management. */
1837 break;
1838 case CHAN_SOCKDATA:
1839 pfd_override_throttle(c->u.x11.s, enable);
1840 break;
1841 }
1842 }
1843}
1844
1845/*
fb09bf1c 1846 * Handle the key exchange and user authentication phases.
1847 */
e5574168 1848static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1849{
2d466ffd 1850 int i, j;
1851 static int len;
1852 static unsigned char *rsabuf, *keystr1, *keystr2;
374330e2 1853 unsigned char cookie[8];
1854 struct RSAKey servkey, hostkey;
1855 struct MD5Context md5c;
ccbfb941 1856 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1857 static int tried_publickey;
614a20a0 1858 static int tis_auth_refused, ccard_auth_refused;
7cca0d81 1859 static unsigned char session_id[16];
2d466ffd 1860 static int cipher_type;
b585ec46 1861 static char username[100];
374330e2 1862
374330e2 1863 crBegin;
1864
32874aea 1865 if (!ispkt)
1866 crWaitUntil(ispkt);
374330e2 1867
8d5de777 1868 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1869 bombout(("Public key packet not received"));
32874aea 1870 crReturn(0);
8d5de777 1871 }
374330e2 1872
c5e9c988 1873 logevent("Received public keys");
374330e2 1874
c5e9c988 1875 memcpy(cookie, pktin.body, 8);
374330e2 1876
32874aea 1877 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1878 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
374330e2 1879
c5e9c988 1880 /*
1c2a93c4 1881 * Log the host key fingerprint.
c5e9c988 1882 */
c5e9c988 1883 {
1884 char logmsg[80];
1c2a93c4 1885 logevent("Host key fingerprint is:");
c5e9c988 1886 strcpy(logmsg, " ");
32874aea 1887 hostkey.comment = NULL;
1888 rsa_fingerprint(logmsg + strlen(logmsg),
1889 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 1890 logevent(logmsg);
1891 }
1892
32874aea 1893 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1894 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1895 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
bea1ef5f 1896
32874aea 1897 ssh1_local_protoflags =
1898 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
b96dc54c 1899 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1900
c5e9c988 1901 MD5Init(&md5c);
374330e2 1902 MD5Update(&md5c, keystr2, hostkey.bytes);
1903 MD5Update(&md5c, keystr1, servkey.bytes);
1904 MD5Update(&md5c, pktin.body, 8);
374330e2 1905 MD5Final(session_id, &md5c);
1906
32874aea 1907 for (i = 0; i < 32; i++)
374330e2 1908 session_key[i] = random_byte();
1909
1910 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1911
dcbde236 1912 rsabuf = smalloc(len);
374330e2 1913 if (!rsabuf)
1914 fatalbox("Out of memory");
1915
89ee5268 1916 /*
1917 * Verify the host key.
1918 */
1919 {
32874aea 1920 /*
1921 * First format the key into a string.
1922 */
1923 int len = rsastr_len(&hostkey);
1924 char fingerprint[100];
1925 char *keystr = smalloc(len);
1926 if (!keystr)
1927 fatalbox("Out of memory");
1928 rsastr_fmt(keystr, &hostkey);
1929 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1930 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1931 fingerprint);
1932 sfree(keystr);
1933 }
1934
1935 for (i = 0; i < 32; i++) {
374330e2 1936 rsabuf[i] = session_key[i];
1937 if (i < 16)
1938 rsabuf[i] ^= session_id[i];
1939 }
1940
1941 if (hostkey.bytes > servkey.bytes) {
1942 rsaencrypt(rsabuf, 32, &servkey);
1943 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1944 } else {
1945 rsaencrypt(rsabuf, 32, &hostkey);
1946 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1947 }
1948
c5e9c988 1949 logevent("Encrypted session key");
1950
ca20bfcf 1951 {
1952 int cipher_chosen = 0, warn = 0;
1953 char *cipher_string = NULL;
1954 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
1955 int next_cipher = cfg.ssh_cipherlist[i];
1956 if (next_cipher == CIPHER_WARN) {
1957 /* If/when we choose a cipher, warn about it */
1958 warn = 1;
1959 } else if (next_cipher == CIPHER_AES) {
1960 /* XXX Probably don't need to mention this. */
1961 logevent("AES not supported in SSH1, skipping");
1962 } else {
1963 switch (next_cipher) {
1964 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
1965 cipher_string = "3DES"; break;
1966 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
1967 cipher_string = "Blowfish"; break;
1968 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
1969 cipher_string = "single-DES"; break;
1970 }
1971 if (supported_ciphers_mask & (1 << cipher_type))
1972 cipher_chosen = 1;
1973 }
1974 }
1975 if (!cipher_chosen) {
1976 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
1977 bombout(("Server violates SSH 1 protocol by not "
1978 "supporting 3DES encryption"));
1979 else
1980 /* shouldn't happen */
1981 bombout(("No supported ciphers found"));
a99a05c0 1982 crReturn(0);
1983 }
ca20bfcf 1984
1985 /* Warn about chosen cipher if necessary. */
1986 if (warn)
1987 askcipher(cipher_string, 0);
bea1ef5f 1988 }
ca20bfcf 1989
c5e9c988 1990 switch (cipher_type) {
32874aea 1991 case SSH_CIPHER_3DES:
1992 logevent("Using 3DES encryption");
1993 break;
1994 case SSH_CIPHER_DES:
1995 logevent("Using single-DES encryption");
1996 break;
1997 case SSH_CIPHER_BLOWFISH:
1998 logevent("Using Blowfish encryption");
1999 break;
c5e9c988 2000 }
bea1ef5f 2001
e5574168 2002 send_packet(SSH1_CMSG_SESSION_KEY,
32874aea 2003 PKT_CHAR, cipher_type,
2004 PKT_DATA, cookie, 8,
2005 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2006 PKT_DATA, rsabuf, len,
2007 PKT_INT, ssh1_local_protoflags, PKT_END);
fb09bf1c 2008
c5e9c988 2009 logevent("Trying to enable encryption...");
374330e2 2010
dcbde236 2011 sfree(rsabuf);
374330e2 2012
5e8358ad 2013 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
32874aea 2014 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
374330e2 2015 cipher->sesskey(session_key);
2016
fb09bf1c 2017 crWaitUntil(ispkt);
374330e2 2018
8d5de777 2019 if (pktin.type != SSH1_SMSG_SUCCESS) {
2020 bombout(("Encryption not successfully enabled"));
32874aea 2021 crReturn(0);
8d5de777 2022 }
374330e2 2023
c5e9c988 2024 logevent("Successfully started encryption");
2025
374330e2 2026 fflush(stdout);
2027 {
374330e2 2028 static int pos = 0;
2029 static char c;
67779be7 2030 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 2031 if (ssh_get_line) {
2032 if (!ssh_get_line("login as: ",
2033 username, sizeof(username), FALSE)) {
2034 /*
2035 * get_line failed to get a username.
2036 * Terminate.
2037 */
2038 logevent("No username provided. Abandoning session.");
2039 ssh_state = SSH_STATE_CLOSED;
2040 crReturn(1);
2041 }
2042 } else {
2043 c_write_str("login as: ");
2044 ssh_send_ok = 1;
2045 while (pos >= 0) {
2046 crWaitUntil(!ispkt);
2047 while (inlen--)
2048 switch (c = *in++) {
2049 case 10:
2050 case 13:
2051 username[pos] = 0;
2052 pos = -1;
2053 break;
2054 case 8:
2055 case 127:
2056 if (pos > 0) {
2057 c_write_str("\b \b");
2058 pos--;
2059 }
2060 break;
2061 case 21:
2062 case 27:
2063 while (pos > 0) {
2064 c_write_str("\b \b");
2065 pos--;
2066 }
2067 break;
2068 case 3:
2069 case 4:
2070 random_save_seed();
2071 exit(0);
2072 break;
2073 default:
2074 if (((c >= ' ' && c <= '~') ||
51b2fb65 2075 ((unsigned char) c >= 160))
2076 && pos < sizeof(username)-1) {
32874aea 2077 username[pos++] = c;
2078 c_write(&c, 1);
2079 }
2080 break;
2081 }
2082 }
2083 c_write_str("\r\n");
2084 username[strcspn(username, "\n\r")] = '\0';
2085 }
2086 } else {
374330e2 2087 strncpy(username, cfg.username, 99);
2088 username[99] = '\0';
374330e2 2089 }
fb09bf1c 2090
e5574168 2091 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 2092 {
32874aea 2093 char userlog[22 + sizeof(username)];
c5e9c988 2094 sprintf(userlog, "Sent username \"%s\"", username);
2095 logevent(userlog);
32874aea 2096 if (flags & FLAG_INTERACTIVE &&
2097 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2098 strcat(userlog, "\r\n");
32874aea 2099 c_write_str(userlog);
3c8e959b 2100 }
c5e9c988 2101 }
374330e2 2102 }
2103
fb09bf1c 2104 crWaitUntil(ispkt);
374330e2 2105
7cca0d81 2106 tried_publickey = 0;
614a20a0 2107 tis_auth_refused = ccard_auth_refused = 0;
7cca0d81 2108
e5574168 2109 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 2110 static char password[100];
a52f067e 2111 static char prompt[200];
374330e2 2112 static int pos;
2113 static char c;
32874aea 2114 static int pwpkt_type;
32874aea 2115 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2116
32874aea 2117 if (agent_exists()) {
2118 /*
2119 * Attempt RSA authentication using Pageant.
2120 */
2121 static unsigned char request[5], *response, *p;
2122 static int responselen;
2123 static int i, nkeys;
2124 static int authed = FALSE;
2125 void *r;
2126
2127 logevent("Pageant is running. Requesting keys.");
2128
2129 /* Request the keys held by the agent. */
2130 PUT_32BIT(request, 1);
2131 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2132 agent_query(request, 5, &r, &responselen);
2133 response = (unsigned char *) r;
2134 if (response && responselen >= 5 &&
2135 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2136 p = response + 5;
2137 nkeys = GET_32BIT(p);
2138 p += 4;
2139 {
2140 char buf[64];
2141 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2142 logevent(buf);
2143 }
2144 for (i = 0; i < nkeys; i++) {
2145 static struct RSAKey key;
2146 static Bignum challenge;
2147 static char *commentp;
2148 static int commentlen;
2149
2150 {
2151 char buf[64];
2152 sprintf(buf, "Trying Pageant key #%d", i);
2153 logevent(buf);
2154 }
2155 p += 4;
2156 p += ssh1_read_bignum(p, &key.exponent);
2157 p += ssh1_read_bignum(p, &key.modulus);
2158 commentlen = GET_32BIT(p);
2159 p += 4;
2160 commentp = p;
2161 p += commentlen;
2162 send_packet(SSH1_CMSG_AUTH_RSA,
2163 PKT_BIGNUM, key.modulus, PKT_END);
2164 crWaitUntil(ispkt);
2165 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2166 logevent("Key refused");
2167 continue;
2168 }
2169 logevent("Received RSA challenge");
2170 ssh1_read_bignum(pktin.body, &challenge);
2171 {
2172 char *agentreq, *q, *ret;
2d466ffd 2173 void *vret;
32874aea 2174 int len, retlen;
2175 len = 1 + 4; /* message type, bit count */
2176 len += ssh1_bignum_length(key.exponent);
2177 len += ssh1_bignum_length(key.modulus);
2178 len += ssh1_bignum_length(challenge);
2179 len += 16; /* session id */
2180 len += 4; /* response format */
2181 agentreq = smalloc(4 + len);
2182 PUT_32BIT(agentreq, len);
2183 q = agentreq + 4;
2184 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2185 PUT_32BIT(q, bignum_bitcount(key.modulus));
2186 q += 4;
2187 q += ssh1_write_bignum(q, key.exponent);
2188 q += ssh1_write_bignum(q, key.modulus);
2189 q += ssh1_write_bignum(q, challenge);
2190 memcpy(q, session_id, 16);
2191 q += 16;
2192 PUT_32BIT(q, 1); /* response format */
2d466ffd 2193 agent_query(agentreq, len + 4, &vret, &retlen);
2194 ret = vret;
32874aea 2195 sfree(agentreq);
2196 if (ret) {
2197 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2198 logevent("Sending Pageant's response");
2199 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2200 PKT_DATA, ret + 5, 16,
2201 PKT_END);
2202 sfree(ret);
2203 crWaitUntil(ispkt);
2204 if (pktin.type == SSH1_SMSG_SUCCESS) {
2205 logevent
2206 ("Pageant's response accepted");
2207 if (flags & FLAG_VERBOSE) {
2208 c_write_str
2209 ("Authenticated using RSA key \"");
2210 c_write(commentp, commentlen);
2211 c_write_str("\" from agent\r\n");
2212 }
2213 authed = TRUE;
2214 } else
2215 logevent
2216 ("Pageant's response not accepted");
2217 } else {
2218 logevent
2219 ("Pageant failed to answer challenge");
2220 sfree(ret);
2221 }
2222 } else {
2223 logevent("No reply received from Pageant");
2224 }
2225 }
2226 freebn(key.exponent);
2227 freebn(key.modulus);
2228 freebn(challenge);
2229 if (authed)
2230 break;
2231 }
2232 }
2233 if (authed)
2234 break;
2235 }
2236 if (*cfg.keyfile && !tried_publickey)
2237 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2238
614a20a0 2239 if (cfg.try_tis_auth &&
2240 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2241 !tis_auth_refused) {
32874aea 2242 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2243 logevent("Requested TIS authentication");
2244 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2245 crWaitUntil(ispkt);
2246 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2247 logevent("TIS authentication declined");
2248 if (flags & FLAG_INTERACTIVE)
2249 c_write_str("TIS authentication refused.\r\n");
614a20a0 2250 tis_auth_refused = 1;
2251 continue;
32874aea 2252 } else {
2253 int challengelen = ((pktin.body[0] << 24) |
2254 (pktin.body[1] << 16) |
2255 (pktin.body[2] << 8) |
2256 (pktin.body[3]));
2257 logevent("Received TIS challenge");
2258 if (challengelen > sizeof(prompt) - 1)
2259 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2260 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2261 /* Prompt heuristic comes from OpenSSH */
2262 strncpy(prompt + challengelen,
2263 memchr(prompt, '\n', challengelen) ?
2264 "": "\r\nResponse: ",
2265 (sizeof prompt) - challengelen);
2266 prompt[(sizeof prompt) - 1] = '\0';
32874aea 2267 }
2268 }
614a20a0 2269 if (cfg.try_tis_auth &&
2270 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2271 !ccard_auth_refused) {
32874aea 2272 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2273 logevent("Requested CryptoCard authentication");
2274 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2275 crWaitUntil(ispkt);
2276 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2277 logevent("CryptoCard authentication declined");
2278 c_write_str("CryptoCard authentication refused.\r\n");
614a20a0 2279 ccard_auth_refused = 1;
2280 continue;
32874aea 2281 } else {
2282 int challengelen = ((pktin.body[0] << 24) |
2283 (pktin.body[1] << 16) |
2284 (pktin.body[2] << 8) |
2285 (pktin.body[3]));
2286 logevent("Received CryptoCard challenge");
2287 if (challengelen > sizeof(prompt) - 1)
2288 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2289 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2290 strncpy(prompt + challengelen,
2291 memchr(prompt, '\n', challengelen) ?
2292 "" : "\r\nResponse: ",
32874aea 2293 sizeof(prompt) - challengelen);
2294 prompt[sizeof(prompt) - 1] = '\0';
2295 }
2296 }
2297 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2298 sprintf(prompt, "%.90s@%.90s's password: ",
2299 username, savedhost);
2300 }
2301 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2302 char *comment = NULL;
2303 if (flags & FLAG_VERBOSE)
2304 c_write_str("Trying public key authentication.\r\n");
2305 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2306 if (flags & FLAG_VERBOSE)
2307 c_write_str("No passphrase required.\r\n");
2308 goto tryauth;
2309 }
2310 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2311 sfree(comment);
2312 }
a52f067e 2313
614a20a0 2314 /*
2315 * Show password prompt, having first obtained it via a TIS
2316 * or CryptoCard exchange if we're doing TIS or CryptoCard
2317 * authentication.
2318 */
fa17a66e 2319 if (ssh_get_line) {
2320 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
32874aea 2321 /*
2322 * get_line failed to get a password (for example
2323 * because one was supplied on the command line
2324 * which has already failed to work). Terminate.
2325 */
2bc6a386 2326 send_packet(SSH1_MSG_DISCONNECT,
2327 PKT_STR, "No more passwords available to try",
2328 PKT_END);
2329 connection_fatal("Unable to authenticate");
32874aea 2330 ssh_state = SSH_STATE_CLOSED;
2331 crReturn(1);
2332 }
fb09bf1c 2333 } else {
614a20a0 2334 /* Prompt may have come from server. We've munged it a bit, so
2335 * we know it to be zero-terminated at least once. */
2336 c_write_untrusted(prompt, strlen(prompt));
32874aea 2337 pos = 0;
2338 ssh_send_ok = 1;
2339 while (pos >= 0) {
2340 crWaitUntil(!ispkt);
2341 while (inlen--)
2342 switch (c = *in++) {
2343 case 10:
2344 case 13:
2345 password[pos] = 0;
2346 pos = -1;
2347 break;
2348 case 8:
2349 case 127:
2350 if (pos > 0)
2351 pos--;
2352 break;
2353 case 21:
2354 case 27:
2355 pos = 0;
2356 break;
2357 case 3:
2358 case 4:
2359 random_save_seed();
2360 exit(0);
2361 break;
2362 default:
51b2fb65 2363 if (pos < sizeof(password)-1)
32874aea 2364 password[pos++] = c;
2365 break;
2366 }
2367 }
2368 c_write_str("\r\n");
2369 }
2370
2371 tryauth:
7cca0d81 2372 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2373 /*
2374 * Try public key authentication with the specified
2375 * key file.
2376 */
2377 static struct RSAKey pubkey;
2378 static Bignum challenge, response;
2379 static int i;
2380 static unsigned char buffer[32];
2381
2382 tried_publickey = 1;
2383 i = loadrsakey(cfg.keyfile, &pubkey, password);
2384 if (i == 0) {
7963af2f 2385 c_write_str("Couldn't load private key from ");
32874aea 2386 c_write_str(cfg.keyfile);
2387 c_write_str(".\r\n");
2388 continue; /* go and try password */
2389 }
2390 if (i == -1) {
2391 c_write_str("Wrong passphrase.\r\n");
2392 tried_publickey = 0;
2393 continue; /* try again */
2394 }
2395
2396 /*
2397 * Send a public key attempt.
2398 */
2399 send_packet(SSH1_CMSG_AUTH_RSA,
2400 PKT_BIGNUM, pubkey.modulus, PKT_END);
2401
2402 crWaitUntil(ispkt);
2403 if (pktin.type == SSH1_SMSG_FAILURE) {
2404 c_write_str("Server refused our public key.\r\n");
2405 continue; /* go and try password */
2406 }
2407 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2408 bombout(("Bizarre response to offer of public key"));
2409 crReturn(0);
2410 }
2411 ssh1_read_bignum(pktin.body, &challenge);
2412 response = rsadecrypt(challenge, &pubkey);
2413 freebn(pubkey.private_exponent); /* burn the evidence */
2414
2415 for (i = 0; i < 32; i++) {
2416 buffer[i] = bignum_byte(response, 31 - i);
2417 }
2418
2419 MD5Init(&md5c);
2420 MD5Update(&md5c, buffer, 32);
2421 MD5Update(&md5c, session_id, 16);
2422 MD5Final(buffer, &md5c);
2423
2424 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2425 PKT_DATA, buffer, 16, PKT_END);
2426
2427 crWaitUntil(ispkt);
2428 if (pktin.type == SSH1_SMSG_FAILURE) {
2429 if (flags & FLAG_VERBOSE)
2430 c_write_str
2431 ("Failed to authenticate with our public key.\r\n");
2432 continue; /* go and try password */
2433 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2434 bombout(
2435 ("Bizarre response to RSA authentication response"));
2436 crReturn(0);
2437 }
2438
2439 break; /* we're through! */
2440 } else {
2441 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2442 /*
2443 * Defence against traffic analysis: we send a
2444 * whole bunch of packets containing strings of
2445 * different lengths. One of these strings is the
2446 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2447 * The others are all random data in
2448 * SSH1_MSG_IGNORE packets. This way a passive
2449 * listener can't tell which is the password, and
2450 * hence can't deduce the password length.
2451 *
2452 * Anybody with a password length greater than 16
2453 * bytes is going to have enough entropy in their
2454 * password that a listener won't find it _that_
2455 * much help to know how long it is. So what we'll
2456 * do is:
2457 *
2458 * - if password length < 16, we send 15 packets
2459 * containing string lengths 1 through 15
2460 *
2461 * - otherwise, we let N be the nearest multiple
2462 * of 8 below the password length, and send 8
2463 * packets containing string lengths N through
2464 * N+7. This won't obscure the order of
2465 * magnitude of the password length, but it will
2466 * introduce a bit of extra uncertainty.
2467 *
2468 * A few servers (the old 1.2.18 through 1.2.22)
2469 * can't deal with SSH1_MSG_IGNORE. For these
2470 * servers, we need an alternative defence. We make
2471 * use of the fact that the password is interpreted
2472 * as a C string: so we can append a NUL, then some
2473 * random data.
bd358db1 2474 *
2475 * One server (a Cisco one) can deal with neither
2476 * SSH1_MSG_IGNORE _nor_ a padded password string.
2477 * For this server we are left with no defences
2478 * against password length sniffing.
32874aea 2479 */
bd358db1 2480 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2481 /*
2482 * The server can deal with SSH1_MSG_IGNORE, so
2483 * we can use the primary defence.
2484 */
32874aea 2485 int bottom, top, pwlen, i;
2486 char *randomstr;
2487
2488 pwlen = strlen(password);
2489 if (pwlen < 16) {
2490 bottom = 0; /* zero length passwords are OK! :-) */
2491 top = 15;
2492 } else {
2493 bottom = pwlen & ~7;
2494 top = bottom + 7;
2495 }
2496
2497 assert(pwlen >= bottom && pwlen <= top);
2498
2499 randomstr = smalloc(top + 1);
2500
2501 for (i = bottom; i <= top; i++) {
2502 if (i == pwlen)
2503 defer_packet(pwpkt_type, PKT_STR, password,
2504 PKT_END);
2505 else {
2506 for (j = 0; j < i; j++) {
2507 do {
2508 randomstr[j] = random_byte();
2509 } while (randomstr[j] == '\0');
2510 }
2511 randomstr[i] = '\0';
2512 defer_packet(SSH1_MSG_IGNORE,
2513 PKT_STR, randomstr, PKT_END);
2514 }
2515 }
bd358db1 2516 logevent("Sending password with camouflage packets");
32874aea 2517 ssh_pkt_defersend();
bd358db1 2518 }
2519 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2520 /*
2521 * The server can't deal with SSH1_MSG_IGNORE
2522 * but can deal with padded passwords, so we
2523 * can use the secondary defence.
2524 */
bd358db1 2525 char string[64];
2526 char *s;
2527 int len;
2528
2529 len = strlen(password);
2530 if (len < sizeof(string)) {
2531 s = string;
2532 strcpy(string, password);
2533 len++; /* cover the zero byte */
2534 while (len < sizeof(string)) {
2535 string[len++] = (char) random_byte();
2536 }
2537 } else {
2538 s = password;
2539 }
2540 logevent("Sending length-padded password");
2541 send_packet(pwpkt_type, PKT_INT, len,
2542 PKT_DATA, s, len, PKT_END);
2543 } else {
2544 /*
2545 * The server has _both_
2546 * BUG_CHOKES_ON_SSH1_IGNORE and
2547 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2548 * therefore nothing we can do.
2549 */
2550 int len;
2551 len = strlen(password);
2552 logevent("Sending unpadded password");
2553 send_packet(pwpkt_type, PKT_INT, len,
2554 PKT_DATA, password, len, PKT_END);
32874aea 2555 }
2556 } else {
2557 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2558 }
2559 }
c5e9c988 2560 logevent("Sent password");
374330e2 2561 memset(password, 0, strlen(password));
fb09bf1c 2562 crWaitUntil(ispkt);
e5574168 2563 if (pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2564 if (flags & FLAG_VERBOSE)
2565 c_write_str("Access denied\r\n");
c5e9c988 2566 logevent("Authentication refused");
e5574168 2567 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2568 logevent("Received disconnect request");
32874aea 2569 ssh_state = SSH_STATE_CLOSED;
85ee8208 2570 crReturn(1);
e5574168 2571 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2572 bombout(("Strange packet received, type %d", pktin.type));
32874aea 2573 crReturn(0);
374330e2 2574 }
2575 }
2576
c5e9c988 2577 logevent("Authentication successful");
2578
fb09bf1c 2579 crFinish(1);
2580}
2581
32874aea 2582void sshfwd_close(struct ssh_channel *c)
2583{
80e48603 2584 if (c && !c->closes) {
4ed34d25 2585 /*
2586 * If the channel's remoteid is -1, we have sent
2587 * CHANNEL_OPEN for this channel, but it hasn't even been
2588 * acknowledged by the server. So we must set a close flag
2589 * on it now, and then when the server acks the channel
2590 * open, we can close it then.
2591 */
2592 if (c->remoteid != -1) {
2593 if (ssh_version == 1) {
2594 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2595 PKT_END);
2596 } else {
2597 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2598 ssh2_pkt_adduint32(c->remoteid);
2599 ssh2_pkt_send();
2600 }
32874aea 2601 }
2602 c->closes = 1;
2603 if (c->type == CHAN_X11) {
2604 c->u.x11.s = NULL;
d74d141c 2605 logevent("Forwarded X11 connection terminated");
4ed34d25 2606 } else if (c->type == CHAN_SOCKDATA ||
2607 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2608 c->u.pfd.s = NULL;
2609 logevent("Forwarded port closed");
32874aea 2610 }
2611 }
2612}
2613
5471d09a 2614int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2615{
783415f8 2616 if (ssh_version == 1) {
32874aea 2617 send_packet(SSH1_MSG_CHANNEL_DATA,
2618 PKT_INT, c->remoteid,
2619 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2620 /*
2621 * In SSH1 we can return 0 here - implying that forwarded
2622 * connections are never individually throttled - because
2623 * the only circumstance that can cause throttling will be
2624 * the whole SSH connection backing up, in which case
2625 * _everything_ will be throttled as a whole.
2626 */
2627 return 0;
783415f8 2628 } else {
32874aea 2629 ssh2_add_channel_data(c, buf, len);
5471d09a 2630 return ssh2_try_send(c);
2631 }
2632}
2633
2634void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2635{
2636 if (ssh_version == 1) {
2637 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2638 c->v.v1.throttling = 0;
2639 ssh1_throttle(-1);
2640 }
2641 } else {
2642 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2643 }
9c964e85 2644}
2645
32874aea 2646static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2647{
fb09bf1c 2648 crBegin;
2649
2650 random_init();
2651
e5574168 2652 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2653 crReturnV;
85ee8208 2654 }
2655 if (ssh_state == SSH_STATE_CLOSED)
32874aea 2656 crReturnV;
fb09bf1c 2657
979310f1 2658 if (cfg.agentfwd && agent_exists()) {
32874aea 2659 logevent("Requesting agent forwarding");
2660 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2661 do {
2662 crReturnV;
2663 } while (!ispkt);
2664 if (pktin.type != SSH1_SMSG_SUCCESS
2665 && pktin.type != SSH1_SMSG_FAILURE) {
2666 bombout(("Protocol confusion"));
2667 crReturnV;
2668 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2669 logevent("Agent forwarding refused");
2670 } else {
2671 logevent("Agent forwarding enabled");
db7d555c 2672 ssh_agentfwd_enabled = TRUE;
2673 }
dacbd0e8 2674 }
2675
9c964e85 2676 if (cfg.x11_forward) {
32874aea 2677 char proto[20], data[64];
2678 logevent("Requesting X11 forwarding");
2679 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2680 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2681 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2682 PKT_STR, proto, PKT_STR, data,
2683 PKT_INT, 0, PKT_END);
2684 } else {
2685 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2686 PKT_STR, proto, PKT_STR, data, PKT_END);
2687 }
2688 do {
2689 crReturnV;
2690 } while (!ispkt);
2691 if (pktin.type != SSH1_SMSG_SUCCESS
2692 && pktin.type != SSH1_SMSG_FAILURE) {
2693 bombout(("Protocol confusion"));
2694 crReturnV;
2695 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2696 logevent("X11 forwarding refused");
2697 } else {
2698 logevent("X11 forwarding enabled");
9c964e85 2699 ssh_X11_fwd_enabled = TRUE;
2700 }
2701 }
2702
d74d141c 2703 {
2704 char type, *e;
2705 int n;
2706 int sport,dport;
2707 char sports[256], dports[256], host[256];
2708 char buf[1024];
2709
bc240b21 2710 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 2711 /* Add port forwardings. */
2712 e = cfg.portfwd;
2713 while (*e) {
2714 type = *e++;
2715 n = 0;
2716 while (*e && *e != '\t')
2717 sports[n++] = *e++;
2718 sports[n] = 0;
2719 if (*e == '\t')
2720 e++;
2721 n = 0;
2722 while (*e && *e != ':')
2723 host[n++] = *e++;
2724 host[n] = 0;
2725 if (*e == ':')
2726 e++;
2727 n = 0;
2728 while (*e)
2729 dports[n++] = *e++;
2730 dports[n] = 0;
2731 e++;
2732 dport = atoi(dports);
2733 sport = atoi(sports);
2734 if (sport && dport) {
2735 if (type == 'L') {
2736 pfd_addforward(host, dport, sport);
2737 sprintf(buf, "Local port %d forwarding to %s:%d",
2738 sport, host, dport);
2739 logevent(buf);
2740 } else {
2741 struct ssh_rportfwd *pf;
2742 pf = smalloc(sizeof(*pf));
bc240b21 2743 strcpy(pf->dhost, host);
2744 pf->dport = dport;
d74d141c 2745 if (add234(ssh_rportfwds, pf) != pf) {
2746 sprintf(buf,
95bc8819 2747 "Duplicate remote port forwarding to %s:%d",
d74d141c 2748 host, dport);
2749 logevent(buf);
bc240b21 2750 sfree(pf);
d74d141c 2751 } else {
2752 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2753 sport, host, dport);
2754 logevent(buf);
2755 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2756 PKT_INT, sport,
2757 PKT_STR, host,
2758 PKT_INT, dport,
2759 PKT_END);
2760 }
2761 }
2762 }
2763 }
2764 }
2765
fef97f43 2766 if (!cfg.nopty) {
e5574168 2767 send_packet(SSH1_CMSG_REQUEST_PTY,
32874aea 2768 PKT_STR, cfg.termtype,
2769 PKT_INT, rows, PKT_INT, cols,
2770 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2771 ssh_state = SSH_STATE_INTERMED;
2772 do {
2773 crReturnV;
2774 } while (!ispkt);
2775 if (pktin.type != SSH1_SMSG_SUCCESS
2776 && pktin.type != SSH1_SMSG_FAILURE) {
2777 bombout(("Protocol confusion"));
2778 crReturnV;
2779 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2780 c_write_str("Server refused to allocate pty\r\n");
2781 ssh_editing = ssh_echoing = 1;
2782 }
c5e9c988 2783 logevent("Allocated pty");
0965bee0 2784 } else {
32874aea 2785 ssh_editing = ssh_echoing = 1;
374330e2 2786 }
2787
4ba9b64b 2788 if (cfg.compression) {
32874aea 2789 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2790 do {
2791 crReturnV;
2792 } while (!ispkt);
2793 if (pktin.type != SSH1_SMSG_SUCCESS
2794 && pktin.type != SSH1_SMSG_FAILURE) {
2795 bombout(("Protocol confusion"));
2796 crReturnV;
2797 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2798 c_write_str("Server refused to compress\r\n");
2799 }
4ba9b64b 2800 logevent("Started compression");
2801 ssh1_compressing = TRUE;
2802 zlib_compress_init();
2803 zlib_decompress_init();
2804 }
2805
fd5e5847 2806 /*
2807 * Start the shell or command.
2808 *
2809 * Special case: if the first-choice command is an SSH2
2810 * subsystem (hence not usable here) and the second choice
2811 * exists, we fall straight back to that.
2812 */
2813 {
2814 char *cmd = cfg.remote_cmd_ptr;
2815
2816 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
2817 cmd = cfg.remote_cmd_ptr2;
2818 ssh_fallback_cmd = TRUE;
2819 }
2820 if (*cmd)
2821 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2822 else
2823 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2824 logevent("Started session");
2825 }
374330e2 2826
2827 ssh_state = SSH_STATE_SESSION;
2828 if (size_needed)
2829 ssh_size();
3687d221 2830 if (eof_needed)
32874aea 2831 ssh_special(TS_EOF);
374330e2 2832
760e88b2 2833 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 2834 ssh_send_ok = 1;
dacbd0e8 2835 ssh_channels = newtree234(ssh_channelcmp);
374330e2 2836 while (1) {
2837 crReturnV;
2838 if (ispkt) {
e5574168 2839 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 2840 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2841 long len = GET_32BIT(pktin.body);
5471d09a 2842 int bufsize =
2843 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2844 pktin.body + 4, len);
90347b95 2845 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 2846 ssh1_stdout_throttling = 1;
2847 ssh1_throttle(+1);
2848 }
e5574168 2849 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
32874aea 2850 ssh_state = SSH_STATE_CLOSED;
c5e9c988 2851 logevent("Received disconnect request");
32874aea 2852 crReturnV;
2853 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2854 /* Remote side is trying to open a channel to talk to our
2855 * X-Server. Give them back a local channel number. */
2856 struct ssh_channel *c;
9c964e85 2857
2858 logevent("Received X11 connect request");
2859 /* Refuse if X11 forwarding is disabled. */
2860 if (!ssh_X11_fwd_enabled) {
2861 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2862 PKT_INT, GET_32BIT(pktin.body), PKT_END);
9c964e85 2863 logevent("Rejected X11 connect request");
2864 } else {
9c964e85 2865 c = smalloc(sizeof(struct ssh_channel));
2866
32874aea 2867 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2868 logevent("opening X11 forward connection failed");
2869 sfree(c);
2870 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2871 PKT_INT, GET_32BIT(pktin.body),
2872 PKT_END);
9c964e85 2873 } else {
32874aea 2874 logevent
2875 ("opening X11 forward connection succeeded");
2876 c->remoteid = GET_32BIT(pktin.body);
2877 c->localid = alloc_channel_id();
2878 c->closes = 0;
5471d09a 2879 c->v.v1.throttling = 0;
32874aea 2880 c->type = CHAN_X11; /* identify channel type */
2881 add234(ssh_channels, c);
2882 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2883 PKT_INT, c->remoteid, PKT_INT,
2884 c->localid, PKT_END);
2885 logevent("Opened X11 forward channel");
9c964e85 2886 }
2887 }
32874aea 2888 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2889 /* Remote side is trying to open a channel to talk to our
2890 * agent. Give them back a local channel number. */
2891 struct ssh_channel *c;
db7d555c 2892
2893 /* Refuse if agent forwarding is disabled. */
2894 if (!ssh_agentfwd_enabled) {
2895 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2896 PKT_INT, GET_32BIT(pktin.body), PKT_END);
db7d555c 2897 } else {
dcbde236 2898 c = smalloc(sizeof(struct ssh_channel));
db7d555c 2899 c->remoteid = GET_32BIT(pktin.body);
d2371c81 2900 c->localid = alloc_channel_id();
db7d555c 2901 c->closes = 0;
5471d09a 2902 c->v.v1.throttling = 0;
32874aea 2903 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 2904 c->u.a.lensofar = 0;
2905 add234(ssh_channels, c);
2906 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2907 PKT_INT, c->remoteid, PKT_INT, c->localid,
2908 PKT_END);
2909 }
d74d141c 2910 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2911 /* Remote side is trying to open a channel to talk to a
2912 * forwarded port. Give them back a local channel number. */
2913 struct ssh_channel *c;
2914 struct ssh_rportfwd pf;
2915 int hostsize, port;
2916 char host[256], buf[1024];
2917 char *p, *h, *e;
2918 c = smalloc(sizeof(struct ssh_channel));
2919
2920 hostsize = GET_32BIT(pktin.body+4);
2921 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2922 if (h+1 < host+sizeof(host))
2923 *h++ = *p;
95bc8819 2924 p++;
d74d141c 2925 }
2926 *h = 0;
2927 port = GET_32BIT(p);
2928
bc240b21 2929 strcpy(pf.dhost, host);
2930 pf.dport = port;
d74d141c 2931
2932 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2933 sprintf(buf, "Rejected remote port open request for %s:%d",
2934 host, port);
2935 logevent(buf);
2936 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2937 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2938 } else {
2939 sprintf(buf, "Received remote port open request for %s:%d",
2940 host, port);
2941 logevent(buf);
2942 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2943 if (e != NULL) {
2944 char buf[256];
2945 sprintf(buf, "Port open failed: %s", e);
2946 logevent(buf);
2947 sfree(c);
2948 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2949 PKT_INT, GET_32BIT(pktin.body),
2950 PKT_END);
2951 } else {
2952 c->remoteid = GET_32BIT(pktin.body);
2953 c->localid = alloc_channel_id();
2954 c->closes = 0;
5471d09a 2955 c->v.v1.throttling = 0;
d74d141c 2956 c->type = CHAN_SOCKDATA; /* identify channel type */
2957 add234(ssh_channels, c);
2958 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2959 PKT_INT, c->remoteid, PKT_INT,
2960 c->localid, PKT_END);
2961 logevent("Forwarded port opened successfully");
2962 }
2963 }
2964
2965 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
bc240b21 2966 unsigned int remoteid = GET_32BIT(pktin.body);
2967 unsigned int localid = GET_32BIT(pktin.body+4);
2968 struct ssh_channel *c;
2969
2970 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2971 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2972 c->remoteid = localid;
2973 c->type = CHAN_SOCKDATA;
7781f316 2974 c->v.v1.throttling = 0;
bc240b21 2975 pfd_confirm(c->u.pfd.s);
2976 }
d74d141c 2977
4ed34d25 2978 if (c && c->closes) {
2979 /*
2980 * We have a pending close on this channel,
2981 * which we decided on before the server acked
2982 * the channel open. So now we know the
2983 * remoteid, we can close it again.
2984 */
2985 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2986 PKT_END);
2987 }
2988
724cface 2989 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
2990 unsigned int remoteid = GET_32BIT(pktin.body);
2991 unsigned int localid = GET_32BIT(pktin.body+4);
2992 struct ssh_channel *c;
2993
2994 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2995 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2996 logevent("Forwarded connection refused by server");
2997 pfd_close(c->u.pfd.s);
2998 del234(ssh_channels, c);
2999 sfree(c);
3000 }
3001
db7d555c 3002 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3003 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3004 /* Remote side closes a channel. */
3005 unsigned i = GET_32BIT(pktin.body);
3006 struct ssh_channel *c;
3007 c = find234(ssh_channels, &i, ssh_channelfind);
3008 if (c) {
3009 int closetype;
3010 closetype =
3011 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3012 if (!(c->closes & closetype))
3013 send_packet(pktin.type, PKT_INT, c->remoteid,
3014 PKT_END);
783415f8 3015 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3016 logevent("Forwarded X11 connection terminated");
9c964e85 3017 assert(c->u.x11.s != NULL);
3018 x11_close(c->u.x11.s);
3019 c->u.x11.s = NULL;
3020 }
d74d141c 3021 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3022 logevent("Forwarded port closed");
3023 assert(c->u.pfd.s != NULL);
3024 pfd_close(c->u.pfd.s);
3025 c->u.pfd.s = NULL;
3026 }
32874aea 3027 c->closes |= closetype;
3028 if (c->closes == 3) {
3029 del234(ssh_channels, c);
3030 sfree(c);
3031 }
3032 }
3033 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3034 /* Data sent down one of our channels. */
3035 int i = GET_32BIT(pktin.body);
3036 int len = GET_32BIT(pktin.body + 4);
3037 unsigned char *p = pktin.body + 8;
3038 struct ssh_channel *c;
3039 c = find234(ssh_channels, &i, ssh_channelfind);
3040 if (c) {
5471d09a 3041 int bufsize;
32874aea 3042 switch (c->type) {
3043 case CHAN_X11:
5471d09a 3044 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 3045 break;
d74d141c 3046 case CHAN_SOCKDATA:
5471d09a 3047 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 3048 break;
32874aea 3049 case CHAN_AGENT:
3050 /* Data for an agent message. Buffer it. */
3051 while (len > 0) {
3052 if (c->u.a.lensofar < 4) {
3053 int l = min(4 - c->u.a.lensofar, len);
3054 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3055 l);
3056 p += l;
3057 len -= l;
3058 c->u.a.lensofar += l;
3059 }
3060 if (c->u.a.lensofar == 4) {
3061 c->u.a.totallen =
3062 4 + GET_32BIT(c->u.a.msglen);
3063 c->u.a.message = smalloc(c->u.a.totallen);
3064 memcpy(c->u.a.message, c->u.a.msglen, 4);
3065 }
3066 if (c->u.a.lensofar >= 4 && len > 0) {
3067 int l =
3068 min(c->u.a.totallen - c->u.a.lensofar,
3069 len);
3070 memcpy(c->u.a.message + c->u.a.lensofar, p,
3071 l);
3072 p += l;
3073 len -= l;
3074 c->u.a.lensofar += l;
3075 }
3076 if (c->u.a.lensofar == c->u.a.totallen) {
3077 void *reply, *sentreply;
3078 int replylen;
3079 agent_query(c->u.a.message,
3080 c->u.a.totallen, &reply,
3081 &replylen);
3082 if (reply)
3083 sentreply = reply;
3084 else {
3085 /* Fake SSH_AGENT_FAILURE. */
3086 sentreply = "\0\0\0\1\5";
3087 replylen = 5;
3088 }
3089 send_packet(SSH1_MSG_CHANNEL_DATA,
3090 PKT_INT, c->remoteid,
3091 PKT_INT, replylen,
3092 PKT_DATA, sentreply, replylen,
3093 PKT_END);
3094 if (reply)
3095 sfree(reply);
3096 sfree(c->u.a.message);
3097 c->u.a.lensofar = 0;
3098 }
3099 }
5471d09a 3100 bufsize = 0; /* agent channels never back up */
32874aea 3101 break;
3102 }
90347b95 3103 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3104 c->v.v1.throttling = 1;
3105 ssh1_throttle(+1);
3106 }
32874aea 3107 }
e5574168 3108 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3109 /* may be from EXEC_SHELL on some servers */
e5574168 3110 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3111 /* may be from EXEC_SHELL on some servers
374330e2 3112 * if no pty is available or in other odd cases. Ignore */
e5574168 3113 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3114 char buf[100];
3115 ssh_exitcode = GET_32BIT(pktin.body);
3116 sprintf(buf, "Server sent command exit status %d",
3117 ssh_exitcode);
3118 logevent(buf);
e5574168 3119 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3120 /*
3121 * In case `helpful' firewalls or proxies tack
3122 * extra human-readable text on the end of the
3123 * session which we might mistake for another
3124 * encrypted packet, we close the session once
3125 * we've sent EXIT_CONFIRMATION.
3126 */
3127 ssh_state = SSH_STATE_CLOSED;
3128 crReturnV;
374330e2 3129 } else {
8d5de777 3130 bombout(("Strange packet received: type %d", pktin.type));
32874aea 3131 crReturnV;
374330e2 3132 }
3133 } else {
8df7a775 3134 while (inlen > 0) {
3135 int len = min(inlen, 512);
3136 send_packet(SSH1_CMSG_STDIN_DATA,
3137 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3138 in += len;
3139 inlen -= len;
3140 }
374330e2 3141 }
3142 }
3143
3144 crFinishV;
3145}
3146
3147/*
e5574168 3148 * Utility routine for decoding comma-separated strings in KEXINIT.
3149 */
32874aea 3150static int in_commasep_string(char *needle, char *haystack, int haylen)
3151{
e5574168 3152 int needlen = strlen(needle);
3153 while (1) {
32874aea 3154 /*
3155 * Is it at the start of the string?
3156 */
3157 if (haylen >= needlen && /* haystack is long enough */
3158 !memcmp(needle, haystack, needlen) && /* initial match */
3159 (haylen == needlen || haystack[needlen] == ',')
3160 /* either , or EOS follows */
3161 )
3162 return 1;
3163 /*
3164 * If not, search for the next comma and resume after that.
3165 * If no comma found, terminate.
3166 */
3167 while (haylen > 0 && *haystack != ',')
3168 haylen--, haystack++;
3169 if (haylen == 0)
3170 return 0;
3171 haylen--, haystack++; /* skip over comma itself */
e5574168 3172 }
3173}
3174
3175/*
d39f364a 3176 * SSH2 key creation method.
3177 */
32874aea 3178static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3179 char *keyspace)
3180{
d39f364a 3181 SHA_State s;
3182 /* First 20 bytes. */
3183 SHA_Init(&s);
3184 sha_mpint(&s, K);
3185 SHA_Bytes(&s, H, 20);
3186 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3187 SHA_Bytes(&s, sessid, 20);
d39f364a 3188 SHA_Final(&s, keyspace);
3189 /* Next 20 bytes. */
3190 SHA_Init(&s);
3191 sha_mpint(&s, K);
3192 SHA_Bytes(&s, H, 20);
3193 SHA_Bytes(&s, keyspace, 20);
32874aea 3194 SHA_Final(&s, keyspace + 20);
d39f364a 3195}
3196
3197/*
7cca0d81 3198 * Handle the SSH2 transport layer.
e5574168 3199 */
7cca0d81 3200static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 3201{
ca20bfcf 3202 static int i, j, len, nbits, pbits, warn;
e5574168 3203 static char *str;
a92dd380 3204 static Bignum p, g, e, f, K;
3205 static int kex_init_value, kex_reply_value;
7591b9ff 3206 static const struct ssh_mac **maclist;
8b2715b2 3207 static int nmacs;
0a3f1d48 3208 static const struct ssh2_cipher *cscipher_tobe = NULL;
3209 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 3210 static const struct ssh_mac *csmac_tobe = NULL;
3211 static const struct ssh_mac *scmac_tobe = NULL;
3212 static const struct ssh_compress *cscomp_tobe = NULL;
3213 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 3214 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 3215 static int hostkeylen, siglen;
e055a386 3216 static void *hkey; /* actual host key */
e5574168 3217 static unsigned char exchange_hash[20];
d39f364a 3218 static unsigned char keyspace[40];
ca20bfcf 3219 static int n_preferred_ciphers;
3220 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4ba9b64b 3221 static const struct ssh_compress *preferred_comp;
087abe1a 3222 static int cipherstr_started;
0db56f73 3223 static int first_kex;
e5574168 3224
3225 crBegin;
7cca0d81 3226 random_init();
0db56f73 3227 first_kex = 1;
e5574168 3228
5e8358ad 3229 /*
ca20bfcf 3230 * Set up the preferred ciphers. (NULL => warn below here)
5e8358ad 3231 */
ca20bfcf 3232 n_preferred_ciphers = 0;
3233 for (i = 0; i < CIPHER_MAX; i++) {
3234 switch (cfg.ssh_cipherlist[i]) {
3235 case CIPHER_BLOWFISH:
3236 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3237 n_preferred_ciphers++;
3238 break;
3239 case CIPHER_DES:
087abe1a 3240 if (cfg.ssh2_des_cbc) {
3241 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3242 n_preferred_ciphers++;
3243 }
ca20bfcf 3244 break;
3245 case CIPHER_3DES:
3246 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3247 n_preferred_ciphers++;
3248 break;
3249 case CIPHER_AES:
3250 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3251 n_preferred_ciphers++;
3252 break;
3253 case CIPHER_WARN:
3254 /* Flag for later. Don't bother if it's the last in
3255 * the list. */
3256 if (i < CIPHER_MAX - 1) {
3257 preferred_ciphers[n_preferred_ciphers] = NULL;
3258 n_preferred_ciphers++;
3259 }
3260 break;
3261 }
5e8358ad 3262 }
ca20bfcf 3263
3264 /*
3265 * Set up preferred compression.
3266 */
4ba9b64b 3267 if (cfg.compression)
3268 preferred_comp = &ssh_zlib;
3269 else
3270 preferred_comp = &ssh_comp_none;
5e8358ad 3271
7591b9ff 3272 /*
3273 * Be prepared to work around the buggy MAC problem.
3274 */
7d503c31 3275 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
32874aea 3276 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 3277 else
32874aea 3278 maclist = macs, nmacs = lenof(macs);
7591b9ff 3279
32874aea 3280 begin_key_exchange:
e5574168 3281 /*
3282 * Construct and send our key exchange packet.
3283 */
3284 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3285 for (i = 0; i < 16; i++)
32874aea 3286 ssh2_pkt_addbyte((unsigned char) random_byte());
e5574168 3287 /* List key exchange algorithms. */
3288 ssh2_pkt_addstring_start();
3289 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3290 ssh2_pkt_addstring_str(kex_algs[i]->name);
3291 if (i < lenof(kex_algs) - 1)
3292 ssh2_pkt_addstring_str(",");
e5574168 3293 }
3294 /* List server host key algorithms. */
3295 ssh2_pkt_addstring_start();
3296 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3297 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3298 if (i < lenof(hostkey_algs) - 1)
3299 ssh2_pkt_addstring_str(",");
e5574168 3300 }
3301 /* List client->server encryption algorithms. */
3302 ssh2_pkt_addstring_start();
087abe1a 3303 cipherstr_started = 0;
ca20bfcf 3304 for (i = 0; i < n_preferred_ciphers; i++) {
3305 const struct ssh2_ciphers *c = preferred_ciphers[i];
3306 if (!c) continue; /* warning flag */
32874aea 3307 for (j = 0; j < c->nciphers; j++) {
087abe1a 3308 if (cipherstr_started)
32874aea 3309 ssh2_pkt_addstring_str(",");
087abe1a 3310 ssh2_pkt_addstring_str(c->list[j]->name);
3311 cipherstr_started = 1;
32874aea 3312 }
e5574168 3313 }
3314 /* List server->client encryption algorithms. */
3315 ssh2_pkt_addstring_start();
087abe1a 3316 cipherstr_started = 0;
ca20bfcf 3317 for (i = 0; i < n_preferred_ciphers; i++) {
3318 const struct ssh2_ciphers *c = preferred_ciphers[i];
3319 if (!c) continue; /* warning flag */
32874aea 3320 for (j = 0; j < c->nciphers; j++) {
087abe1a 3321 if (cipherstr_started)
32874aea 3322 ssh2_pkt_addstring_str(",");
087abe1a 3323 ssh2_pkt_addstring_str(c->list[j]->name);
3324 cipherstr_started = 1;
32874aea 3325 }
e5574168 3326 }
3327 /* List client->server MAC algorithms. */
3328 ssh2_pkt_addstring_start();
8b2715b2 3329 for (i = 0; i < nmacs; i++) {
32874aea 3330 ssh2_pkt_addstring_str(maclist[i]->name);
3331 if (i < nmacs - 1)
3332 ssh2_pkt_addstring_str(",");
e5574168 3333 }
3334 /* List server->client MAC algorithms. */
3335 ssh2_pkt_addstring_start();
8b2715b2 3336 for (i = 0; i < nmacs; i++) {
32874aea 3337 ssh2_pkt_addstring_str(maclist[i]->name);
3338 if (i < nmacs - 1)
3339 ssh2_pkt_addstring_str(",");
e5574168 3340 }
3341 /* List client->server compression algorithms. */
3342 ssh2_pkt_addstring_start();
32874aea 3343 for (i = 0; i < lenof(compressions) + 1; i++) {
3344 const struct ssh_compress *c =
3345 i == 0 ? preferred_comp : compressions[i - 1];
3346 ssh2_pkt_addstring_str(c->name);
3347 if (i < lenof(compressions))
3348 ssh2_pkt_addstring_str(",");
e5574168 3349 }
3350 /* List server->client compression algorithms. */
3351 ssh2_pkt_addstring_start();
32874aea 3352 for (i = 0; i < lenof(compressions) + 1; i++) {
3353 const struct ssh_compress *c =
3354 i == 0 ? preferred_comp : compressions[i - 1];
3355 ssh2_pkt_addstring_str(c->name);
3356 if (i < lenof(compressions))
3357 ssh2_pkt_addstring_str(",");
e5574168 3358 }
3359 /* List client->server languages. Empty list. */
3360 ssh2_pkt_addstring_start();
3361 /* List server->client languages. Empty list. */
3362 ssh2_pkt_addstring_start();
3363 /* First KEX packet does _not_ follow, because we're not that brave. */
3364 ssh2_pkt_addbool(FALSE);
3365 /* Reserved. */
3366 ssh2_pkt_adduint32(0);
0db56f73 3367
3368 exhash = exhashbase;
32874aea 3369 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
0db56f73 3370
e5574168 3371 ssh2_pkt_send();
3372
32874aea 3373 if (!ispkt)
3374 crWaitUntil(ispkt);
3375 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
e5574168 3376
3377 /*
3378 * Now examine the other side's KEXINIT to see what we're up
3379 * to.
3380 */
7cca0d81 3381 if (pktin.type != SSH2_MSG_KEXINIT) {
32874aea 3382 bombout(("expected key exchange packet from server"));
3383 crReturn(0);
7cca0d81 3384 }
32874aea 3385 kex = NULL;
3386 hostkey = NULL;
3387 cscipher_tobe = NULL;
3388 sccipher_tobe = NULL;
3389 csmac_tobe = NULL;
3390 scmac_tobe = NULL;
3391 cscomp_tobe = NULL;
3392 sccomp_tobe = NULL;
3393 pktin.savedpos += 16; /* skip garbage cookie */
e5574168 3394 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3395 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3396 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3397 kex = kex_algs[i];
3398 break;
3399 }
e5574168 3400 }
3401 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3402 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3403 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3404 hostkey = hostkey_algs[i];
3405 break;
3406 }
e5574168 3407 }
3408 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
ca20bfcf 3409 warn = 0;
3410 for (i = 0; i < n_preferred_ciphers; i++) {
3411 const struct ssh2_ciphers *c = preferred_ciphers[i];
3412 if (!c) {
3413 warn = 1;
3414 } else {
3415 for (j = 0; j < c->nciphers; j++) {
3416 if (in_commasep_string(c->list[j]->name, str, len)) {
3417 cscipher_tobe = c->list[j];
3418 break;
3419 }
32874aea 3420 }
3421 }
ca20bfcf 3422 if (cscipher_tobe) {
3423 if (warn)
3424 askcipher(cscipher_tobe->name, 1);
32874aea 3425 break;
ca20bfcf 3426 }
e5574168 3427 }
0ef8f407 3428 if (!cscipher_tobe) {
3429 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3430 crReturn(0);
3431 }
3432
e5574168 3433 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
ca20bfcf 3434 warn = 0;
3435 for (i = 0; i < n_preferred_ciphers; i++) {
3436 const struct ssh2_ciphers *c = preferred_ciphers[i];
3437 if (!c) {
3438 warn = 1;
3439 } else {
3440 for (j = 0; j < c->nciphers; j++) {
3441 if (in_commasep_string(c->list[j]->name, str, len)) {
3442 sccipher_tobe = c->list[j];
3443 break;
3444 }
32874aea 3445 }
3446 }
ca20bfcf 3447 if (sccipher_tobe) {
3448 if (warn)
3449 askcipher(sccipher_tobe->name, 2);
32874aea 3450 break;
ca20bfcf 3451 }
e5574168 3452 }
0ef8f407 3453 if (!sccipher_tobe) {
3454 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3455 crReturn(0);
3456 }
3457
e5574168 3458 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 3459 for (i = 0; i < nmacs; i++) {
32874aea 3460 if (in_commasep_string(maclist[i]->name, str, len)) {
3461 csmac_tobe = maclist[i];
3462 break;
3463 }
e5574168 3464 }
3465 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 3466 for (i = 0; i < nmacs; i++) {
32874aea 3467 if (in_commasep_string(maclist[i]->name, str, len)) {
3468 scmac_tobe = maclist[i];
3469 break;
3470 }
e5574168 3471 }
3472 ssh2_pkt_getstring(&str, &len); /* client->server compression */
32874aea 3473 for (i = 0; i < lenof(compressions) + 1; i++) {
3474 const struct ssh_compress *c =
3475 i == 0 ? preferred_comp : compressions[i - 1];
3476 if (in_commasep_string(c->name, str, len)) {
3477 cscomp_tobe = c;
3478 break;
3479 }
e5574168 3480 }
3481 ssh2_pkt_getstring(&str, &len); /* server->client compression */
32874aea 3482 for (i = 0; i < lenof(compressions) + 1; i++) {
3483 const struct ssh_compress *c =
3484 i == 0 ? preferred_comp : compressions[i - 1];
3485 if (in_commasep_string(c->name, str, len)) {
3486 sccomp_tobe = c;
3487 break;
3488 }
e5574168 3489 }
e5574168 3490
3491 /*
7bd5a860 3492 * Work out the number of bits of key we will need from the key
3493 * exchange. We start with the maximum key length of either
3494 * cipher...
3495 */
3496 {
32874aea 3497 int csbits, scbits;
7bd5a860 3498
3499 csbits = cscipher_tobe->keylen;
3500 scbits = sccipher_tobe->keylen;
3501 nbits = (csbits > scbits ? csbits : scbits);
3502 }
3503 /* The keys only have 160-bit entropy, since they're based on
3504 * a SHA-1 hash. So cap the key size at 160 bits. */
32874aea 3505 if (nbits > 160)
3506 nbits = 160;
7bd5a860 3507
3508 /*
a92dd380 3509 * If we're doing Diffie-Hellman group exchange, start by
3510 * requesting a group.
e5574168 3511 */
a92dd380 3512 if (kex == &ssh_diffiehellman_gex) {
32874aea 3513 logevent("Doing Diffie-Hellman group exchange");
00db133f 3514 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 3515 /*
3516 * Work out how big a DH group we will need to allow that
3517 * much data.
7bd5a860 3518 */
32874aea 3519 pbits = 512 << ((nbits - 1) / 64);
3520 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3521 ssh2_pkt_adduint32(pbits);
3522 ssh2_pkt_send();
3523
3524 crWaitUntil(ispkt);
3525 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3526 bombout(("expected key exchange group packet from server"));
3527 crReturn(0);
3528 }
3529 p = ssh2_pkt_getmp();
3530 g = ssh2_pkt_getmp();
3531 dh_setup_group(p, g);
3532 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3533 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3534 } else {
00db133f 3535 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
32874aea 3536 dh_setup_group1();
3537 kex_init_value = SSH2_MSG_KEXDH_INIT;
3538 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3539 }
e5574168 3540
a92dd380 3541 logevent("Doing Diffie-Hellman key exchange");
e5574168 3542 /*
a92dd380 3543 * Now generate and send e for Diffie-Hellman.
e5574168 3544 */
32874aea 3545 e = dh_create_e(nbits * 2);
a92dd380 3546 ssh2_pkt_init(kex_init_value);
e5574168 3547 ssh2_pkt_addmp(e);
3548 ssh2_pkt_send();
3549
3550 crWaitUntil(ispkt);
a92dd380 3551 if (pktin.type != kex_reply_value) {
32874aea 3552 bombout(("expected key exchange reply packet from server"));
3553 crReturn(0);
7cca0d81 3554 }
e5574168 3555 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3556 f = ssh2_pkt_getmp();
e5574168 3557 ssh2_pkt_getstring(&sigdata, &siglen);
3558
3559 K = dh_find_K(f);
e5574168 3560
3561 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 3562 if (kex == &ssh_diffiehellman_gex) {
32874aea 3563 sha_uint32(&exhash, pbits);
3564 sha_mpint(&exhash, p);
3565 sha_mpint(&exhash, g);
a92dd380 3566 }
e5574168 3567 sha_mpint(&exhash, e);
3568 sha_mpint(&exhash, f);
3569 sha_mpint(&exhash, K);
3570 SHA_Final(&exhash, exchange_hash);
3571
3709bfe9 3572 dh_cleanup();
3573
7cca0d81 3574#if 0
765c4200 3575 debug(("Exchange hash is:\n"));
3576 dmemdump(exchange_hash, 20);
7cca0d81 3577#endif
3578
e055a386 3579 hkey = hostkey->newkey(hostkeydata, hostkeylen);
f7259d10 3580 if (!hkey ||
3581 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3582 bombout(("Server's host key did not match the signature supplied"));
32874aea 3583 crReturn(0);
8d5de777 3584 }
e5574168 3585
3586 /*
7cca0d81 3587 * Authenticate remote host: verify host key. (We've already
3588 * checked the signature of the exchange hash.)
e5574168 3589 */
e055a386 3590 keystr = hostkey->fmtkey(hkey);
3591 fingerprint = hostkey->fingerprint(hkey);
d4857987 3592 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
32874aea 3593 keystr, fingerprint);
3594 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 3595 logevent("Host key fingerprint is:");
3596 logevent(fingerprint);
3597 }
dcbde236 3598 sfree(fingerprint);
3599 sfree(keystr);
e055a386 3600 hostkey->freekey(hkey);
d39f364a 3601
3602 /*
7cca0d81 3603 * Send SSH2_MSG_NEWKEYS.
d39f364a 3604 */
3605 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3606 ssh2_pkt_send();
d39f364a 3607
3608 /*
8406eaf9 3609 * Expect SSH2_MSG_NEWKEYS from server.
3610 */
3611 crWaitUntil(ispkt);
3612 if (pktin.type != SSH2_MSG_NEWKEYS) {
3613 bombout(("expected new-keys packet from server"));
3614 crReturn(0);
3615 }
3616
3617 /*
d39f364a 3618 * Create and initialise session keys.
3619 */
3620 cscipher = cscipher_tobe;
3621 sccipher = sccipher_tobe;
3622 csmac = csmac_tobe;
3623 scmac = scmac_tobe;
3624 cscomp = cscomp_tobe;
3625 sccomp = sccomp_tobe;
4ba9b64b 3626 cscomp->compress_init();
3627 sccomp->decompress_init();
d39f364a 3628 /*
5e0d7cb8 3629 * Set IVs after keys. Here we use the exchange hash from the
3630 * _first_ key exchange.
d39f364a 3631 */
5e0d7cb8 3632 if (first_kex)
65a22376 3633 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3634 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 3635 cscipher->setcskey(keyspace);
65a22376 3636 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 3637 sccipher->setsckey(keyspace);
65a22376 3638 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 3639 cscipher->setcsiv(keyspace);
65a22376 3640 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 3641 sccipher->setsciv(keyspace);
65a22376 3642 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 3643 csmac->setcskey(keyspace);
65a22376 3644 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 3645 scmac->setsckey(keyspace);
d39f364a 3646
033b4cef 3647 /*
0db56f73 3648 * If this is the first key exchange phase, we must pass the
3649 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3650 * wants to see it but because it will need time to initialise
3651 * itself before it sees an actual packet. In subsequent key
3652 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3653 * it would only confuse the layer above.
3654 */
3655 if (!first_kex) {
32874aea 3656 crReturn(0);
0db56f73 3657 }
3658 first_kex = 0;
3659
3660 /*
7cca0d81 3661 * Now we're encrypting. Begin returning 1 to the protocol main
3662 * function so that other things can run on top of the
3663 * transport. If we ever see a KEXINIT, we must go back to the
3664 * start.
033b4cef 3665 */
e96adf72 3666 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 3667 crReturn(1);
e96adf72 3668 }
5e0d7cb8 3669 logevent("Server initiated key re-exchange");
7cca0d81 3670 goto begin_key_exchange;
e5574168 3671
3672 crFinish(1);
3673}
3674
7cca0d81 3675/*
783415f8 3676 * Add data to an SSH2 channel output buffer.
3677 */
32874aea 3678static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3679 int len)
3680{
5471d09a 3681 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 3682}
3683
3684/*
3685 * Attempt to send data on an SSH2 channel.
3686 */
5471d09a 3687static int ssh2_try_send(struct ssh_channel *c)
32874aea 3688{
5471d09a 3689 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3690 int len;
3691 void *data;
3692 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3693 if ((unsigned)len > c->v.v2.remwindow)
3694 len = c->v.v2.remwindow;
3695 if ((unsigned)len > c->v.v2.remmaxpkt)
3696 len = c->v.v2.remmaxpkt;
32874aea 3697 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3698 ssh2_pkt_adduint32(c->remoteid);
3699 ssh2_pkt_addstring_start();
5471d09a 3700 ssh2_pkt_addstring_data(data, len);
32874aea 3701 ssh2_pkt_send();
5471d09a 3702 bufchain_consume(&c->v.v2.outbuffer, len);
3703 c->v.v2.remwindow -= len;
3704 }
3705
3706 /*
3707 * After having sent as much data as we can, return the amount
3708 * still buffered.
3709 */
3710 return bufchain_size(&c->v.v2.outbuffer);
3711}
3712
3713/*
3714 * Potentially enlarge the window on an SSH2 channel.
3715 */
3716static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3717{
3718 if (newwin > c->v.v2.locwindow) {
3719 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3720 ssh2_pkt_adduint32(c->remoteid);
3721 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
3722 ssh2_pkt_send();
3723 c->v.v2.locwindow = newwin;
783415f8 3724 }
3725}
3726
3727/*
7cca0d81 3728 * Handle the SSH2 userauth and connection layers.
3729 */
3730static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3731{
65a22376 3732 static enum {
32874aea 3733 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
761187b6 3734 AUTH_PASSWORD,
3735 AUTH_KEYBOARD_INTERACTIVE
65a22376 3736 } method;
1408a877 3737 static enum {
32874aea 3738 AUTH_TYPE_NONE,
3739 AUTH_TYPE_PUBLICKEY,
3740 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3741 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
761187b6 3742 AUTH_TYPE_PASSWORD,
4bdf7c46 3743 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3744 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
1408a877 3745 } type;
761187b6 3746 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3747 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
b3186d64 3748 static int kbd_inter_running;
1408a877 3749 static int we_are_in;
761187b6 3750 static int num_prompts, echo;
65a22376 3751 static char username[100];
3752 static char pwprompt[200];
3753 static char password[100];
7cca0d81 3754
e5574168 3755 crBegin;
3756
7cca0d81 3757 /*
3758 * Request userauth protocol, and await a response to it.
3759 */
3760 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3761 ssh2_pkt_addstring("ssh-userauth");
3762 ssh2_pkt_send();
3763 crWaitUntilV(ispkt);
8d5de777 3764 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 3765 bombout(("Server refused user authentication protocol"));
3766 crReturnV;
8d5de777 3767 }
7cca0d81 3768
3769 /*
1408a877 3770 * We repeat this whole loop, including the username prompt,
3771 * until we manage a successful authentication. If the user
3772 * types the wrong _password_, they are sent back to the
3773 * beginning to try another username. (If they specify a
3774 * username in the config, they are never asked, even if they
3775 * do give a wrong password.)
3776 *
3777 * I think this best serves the needs of
3778 *
3779 * - the people who have no configuration, no keys, and just
3780 * want to try repeated (username,password) pairs until they
3781 * type both correctly
3782 *
3783 * - people who have keys and configuration but occasionally
3784 * need to fall back to passwords
3785 *
3786 * - people with a key held in Pageant, who might not have
3787 * logged in to a particular machine before; so they want to
3788 * type a username, and then _either_ their key will be
3789 * accepted, _or_ they will type a password. If they mistype
3790 * the username they will want to be able to get back and
3791 * retype it!
7cca0d81 3792 */
5bb641e1 3793 username[0] = '\0';
1408a877 3794 do {
3795 static int pos;
7cca0d81 3796 static char c;
e5574168 3797
1408a877 3798 /*
3799 * Get a username.
3800 */
3801 pos = 0;
5bb641e1 3802 if (*username && !cfg.change_username) {
3803 /*
3804 * We got a username last time round this loop, and
3805 * with change_username turned off we don't try to get
3806 * it again.
3807 */
3808 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 3809 if (ssh_get_line) {
3810 if (!ssh_get_line("login as: ",
3811 username, sizeof(username), FALSE)) {
3812 /*
3813 * get_line failed to get a username.
3814 * Terminate.
3815 */
3816 logevent("No username provided. Abandoning session.");
3817 ssh_state = SSH_STATE_CLOSED;
3818 crReturnV;
3819 }
3820 } else {
3821 c_write_str("login as: ");
3822 ssh_send_ok = 1;
3823 while (pos >= 0) {
3824 crWaitUntilV(!ispkt);
3825 while (inlen--)
3826 switch (c = *in++) {
3827 case 10:
3828 case 13:
3829 username[pos] = 0;
3830 pos = -1;
3831 break;
3832 case 8:
3833 case 127:
3834 if (pos > 0) {
3835 c_write_str("\b \b");
3836 pos--;
3837 }
3838 break;
3839 case 21:
3840 case 27:
3841 while (pos > 0) {
3842 c_write_str("\b \b");
3843 pos--;
3844 }
3845 break;
3846 case 3:
3847 case 4:
3848 random_save_seed();
3849 exit(0);
3850 break;
3851 default:
3852 if (((c >= ' ' && c <= '~') ||
51b2fb65 3853 ((unsigned char) c >= 160))
3854 && pos < sizeof(username)-1) {
32874aea 3855 username[pos++] = c;
3856 c_write(&c, 1);
3857 }
3858 break;
3859 }
3860 }
3861 }
1408a877 3862 c_write_str("\r\n");
7cca0d81 3863 username[strcspn(username, "\n\r")] = '\0';
3864 } else {
3865 char stuff[200];
3866 strncpy(username, cfg.username, 99);
3867 username[99] = '\0';
65a22376 3868 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 3869 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 3870 c_write_str(stuff);
7cca0d81 3871 }
3872 }
3873
65a22376 3874 /*
1408a877 3875 * Send an authentication request using method "none": (a)
3876 * just in case it succeeds, and (b) so that we know what
3877 * authentication methods we can usefully try next.
65a22376 3878 */
00db133f 3879 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
3880
1408a877 3881 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3882 ssh2_pkt_addstring(username);
32874aea 3883 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3884 ssh2_pkt_addstring("none"); /* method */
3885 ssh2_pkt_send();
3886 type = AUTH_TYPE_NONE;
3887 gotit = FALSE;
3888 we_are_in = FALSE;
7cca0d81 3889
1408a877 3890 tried_pubkey_config = FALSE;
1983e559 3891 tried_agent = FALSE;
b3186d64 3892 tried_keyb_inter = FALSE;
3893 kbd_inter_running = FALSE;
65a22376 3894
1408a877 3895 while (1) {
3896 /*
3897 * Wait for the result of the last authentication request.
3898 */
3899 if (!gotit)
3900 crWaitUntilV(ispkt);
3901 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 3902 char *banner;
3903 int size;
3904 /*
3905 * Don't show the banner if we're operating in
3906 * non-verbose non-interactive mode. (It's probably
3907 * a script, which means nobody will read the
3908 * banner _anyway_, and moreover the printing of
3909 * the banner will screw up processing on the
3910 * output of (say) plink.)
3911 */
3912 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3913 ssh2_pkt_getstring(&banner, &size);
3914 if (banner)
3915 c_write_untrusted(banner, size);
3916 }
1408a877 3917 crWaitUntilV(ispkt);
3918 }
3919 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3920 logevent("Access granted");
3921 we_are_in = TRUE;
3922 break;
3923 }
65a22376 3924
b3186d64 3925 if (kbd_inter_running &&
3926 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
3927 /*
3928 * This is a further prompt in keyboard-interactive
3929 * authentication. Do nothing.
3930 */
6bb26b30 3931 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
b3186d64 3932 bombout(("Strange packet received during authentication: type %d",
1408a877 3933 pktin.type));
38c4a8da 3934 crReturnV;
65a22376 3935 }
3936
1408a877 3937 gotit = FALSE;
65a22376 3938
1408a877 3939 /*
3940 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3941 * we can look at the string in it and know what we can
3942 * helpfully try next.
3943 */
b3186d64 3944 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 3945 char *methods;
3946 int methlen;
3947 ssh2_pkt_getstring(&methods, &methlen);
b3186d64 3948 kbd_inter_running = FALSE;
1408a877 3949 if (!ssh2_pkt_getbool()) {
3950 /*
3951 * We have received an unequivocal Access
3952 * Denied. This can translate to a variety of
3953 * messages:
3954 *
3955 * - if we'd just tried "none" authentication,
3956 * it's not worth printing anything at all
3957 *
3958 * - if we'd just tried a public key _offer_,
3959 * the message should be "Server refused our
3960 * key" (or no message at all if the key
3961 * came from Pageant)
3962 *
3963 * - if we'd just tried anything else, the
3964 * message really should be "Access denied".
3965 *
3966 * Additionally, if we'd just tried password
3967 * authentication, we should break out of this
3968 * whole loop so as to go back to the username
3969 * prompt.
3970 */
3971 if (type == AUTH_TYPE_NONE) {
3972 /* do nothing */
3973 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3974 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3975 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3976 c_write_str("Server refused our key\r\n");
3977 logevent("Server refused public key");
4bdf7c46 3978 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
3979 /* server declined keyboard-interactive; ignore */
1408a877 3980 } else {
3981 c_write_str("Access denied\r\n");
3982 logevent("Access denied");
3983 if (type == AUTH_TYPE_PASSWORD) {
3984 we_are_in = FALSE;
3985 break;
3986 }
3987 }
3988 } else {
3989 c_write_str("Further authentication required\r\n");
3990 logevent("Further authentication required");
3991 }
65a22376 3992
32874aea 3993 can_pubkey =
3994 in_commasep_string("publickey", methods, methlen);
3995 can_passwd =
3996 in_commasep_string("password", methods, methlen);
f091e308 3997 can_keyb_inter = cfg.try_ki_auth &&
761187b6 3998 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 3999 }
65a22376 4000
1408a877 4001 method = 0;
00db133f 4002 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4003
78afa559 4004 if (!method && can_pubkey && agent_exists() && !tried_agent) {
1983e559 4005 /*
4006 * Attempt public-key authentication using Pageant.
4007 */
4008 static unsigned char request[5], *response, *p;
4009 static int responselen;
4010 static int i, nkeys;
4011 static int authed = FALSE;
4012 void *r;
4013
00db133f 4014 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4015
1983e559 4016 tried_agent = TRUE;
4017
4018 logevent("Pageant is running. Requesting keys.");
4019
4020 /* Request the keys held by the agent. */
4021 PUT_32BIT(request, 1);
4022 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4023 agent_query(request, 5, &r, &responselen);
32874aea 4024 response = (unsigned char *) r;
95797139 4025 if (response && responselen >= 5 &&
32874aea 4026 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 4027 p = response + 5;
32874aea 4028 nkeys = GET_32BIT(p);
4029 p += 4;
4030 {
4031 char buf[64];
4032 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4033 logevent(buf);
4034 }
1983e559 4035 for (i = 0; i < nkeys; i++) {
4036 static char *pkblob, *alg, *commentp;
4037 static int pklen, alglen, commentlen;
4038 static int siglen, retlen, len;
4039 static char *q, *agentreq, *ret;
2d466ffd 4040 void *vret;
1983e559 4041
32874aea 4042 {
4043 char buf[64];
4044 sprintf(buf, "Trying Pageant key #%d", i);
4045 logevent(buf);
4046 }
4047 pklen = GET_32BIT(p);
4048 p += 4;
4049 pkblob = p;
4050 p += pklen;
1983e559 4051 alglen = GET_32BIT(pkblob);
4052 alg = pkblob + 4;
32874aea 4053 commentlen = GET_32BIT(p);
4054 p += 4;
4055 commentp = p;
4056 p += commentlen;
1983e559 4057 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4058 ssh2_pkt_addstring(username);
32874aea 4059 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4060 ssh2_pkt_addstring("publickey"); /* method */
4061 ssh2_pkt_addbool(FALSE); /* no signature included */
1983e559 4062 ssh2_pkt_addstring_start();
4063 ssh2_pkt_addstring_data(alg, alglen);
4064 ssh2_pkt_addstring_start();
4065 ssh2_pkt_addstring_data(pkblob, pklen);
4066 ssh2_pkt_send();
4067
4068 crWaitUntilV(ispkt);
4069 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4070 logevent("Key refused");
4071 continue;
4072 }
4073
32874aea 4074 if (flags & FLAG_VERBOSE) {
4075 c_write_str
4076 ("Authenticating with public key \"");
4077 c_write(commentp, commentlen);
4078 c_write_str("\" from agent\r\n");
4079 }
1983e559 4080
4081 /*
4082 * Server is willing to accept the key.
4083 * Construct a SIGN_REQUEST.
4084 */
4085 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4086 ssh2_pkt_addstring(username);
32874aea 4087 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4088 ssh2_pkt_addstring("publickey"); /* method */
1983e559 4089 ssh2_pkt_addbool(TRUE);
4090 ssh2_pkt_addstring_start();
4091 ssh2_pkt_addstring_data(alg, alglen);
4092 ssh2_pkt_addstring_start();
4093 ssh2_pkt_addstring_data(pkblob, pklen);
4094
4095 siglen = pktout.length - 5 + 4 + 20;
32874aea 4096 len = 1; /* message type */
4097 len += 4 + pklen; /* key blob */
4098 len += 4 + siglen; /* data to sign */
4099 len += 4; /* flags */
1983e559 4100 agentreq = smalloc(4 + len);
4101 PUT_32BIT(agentreq, len);
4102 q = agentreq + 4;
4103 *q++ = SSH2_AGENTC_SIGN_REQUEST;
32874aea 4104 PUT_32BIT(q, pklen);
4105 q += 4;
4106 memcpy(q, pkblob, pklen);
4107 q += pklen;
4108 PUT_32BIT(q, siglen);
4109 q += 4;
1983e559 4110 /* Now the data to be signed... */
32874aea 4111 PUT_32BIT(q, 20);
4112 q += 4;
4113 memcpy(q, ssh2_session_id, 20);
4114 q += 20;
4115 memcpy(q, pktout.data + 5, pktout.length - 5);
4116 q += pktout.length - 5;
1983e559 4117 /* And finally the (zero) flags word. */
4118 PUT_32BIT(q, 0);
2d466ffd 4119 agent_query(agentreq, len + 4, &vret, &retlen);
4120 ret = vret;
1983e559 4121 sfree(agentreq);
4122 if (ret) {
4123 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4124 logevent("Sending Pageant's response");
4125 ssh2_pkt_addstring_start();
32874aea 4126 ssh2_pkt_addstring_data(ret + 9,
4127 GET_32BIT(ret +
4128 5));
1983e559 4129 ssh2_pkt_send();
4130 authed = TRUE;
4131 break;
4132 } else {
32874aea 4133 logevent
4134 ("Pageant failed to answer challenge");
1983e559 4135 sfree(ret);
4136 }
4137 }
4138 }
4139 if (authed)
4140 continue;
4141 }
4142 }
4143
32874aea 4144 if (!method && can_pubkey && *cfg.keyfile
4145 && !tried_pubkey_config) {
1408a877 4146 unsigned char *pub_blob;
4147 char *algorithm, *comment;
4148 int pub_blob_len;
65a22376 4149
1408a877 4150 tried_pubkey_config = TRUE;
65a22376 4151
00db133f 4152 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4153
65a22376 4154 /*
1408a877 4155 * Try the public key supplied in the configuration.
4156 *
4157 * First, offer the public blob to see if the server is
4158 * willing to accept it.
65a22376 4159 */
1408a877 4160 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4161 &pub_blob_len);
4162 if (pub_blob) {
4163 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4164 ssh2_pkt_addstring(username);
32874aea 4165 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4166 ssh2_pkt_addstring("publickey"); /* method */
4167 ssh2_pkt_addbool(FALSE); /* no signature included */
1408a877 4168 ssh2_pkt_addstring(algorithm);
4169 ssh2_pkt_addstring_start();
4170 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4171 ssh2_pkt_send();
32874aea 4172 logevent("Offered public key"); /* FIXME */
1408a877 4173
4174 crWaitUntilV(ispkt);
4175 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4176 gotit = TRUE;
4177 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4178 continue; /* key refused; give up on it */
1408a877 4179 }
65a22376 4180
1408a877 4181 logevent("Offer of public key accepted");
65a22376 4182 /*
1408a877 4183 * Actually attempt a serious authentication using
4184 * the key.
65a22376 4185 */
1408a877 4186 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
32874aea 4187 sprintf(pwprompt,
4188 "Passphrase for key \"%.100s\": ",
4189 comment);
1408a877 4190 need_pw = TRUE;
4191 } else {
4192 need_pw = FALSE;
4193 }
4194 c_write_str("Authenticating with public key \"");
4195 c_write_str(comment);
4196 c_write_str("\"\r\n");
4197 method = AUTH_PUBLICKEY_FILE;
65a22376 4198 }
1408a877 4199 }
4200
af659722 4201 if (!method && can_keyb_inter && !tried_keyb_inter) {
4202 method = AUTH_KEYBOARD_INTERACTIVE;
4203 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4204 tried_keyb_inter = TRUE;
4205
00db133f 4206 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4207
af659722 4208 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4209 ssh2_pkt_addstring(username);
4210 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4211 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4212 ssh2_pkt_addstring(""); /* lang */
4213 ssh2_pkt_addstring("");
4214 ssh2_pkt_send();
4215
4216 crWaitUntilV(ispkt);
4217 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4218 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4219 gotit = TRUE;
4220 logevent("Keyboard-interactive authentication refused");
4221 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4222 continue;
4223 }
4224
4225 kbd_inter_running = TRUE;
4226 }
4227
4228 if (kbd_inter_running) {
4229 method = AUTH_KEYBOARD_INTERACTIVE;
4230 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4231 tried_keyb_inter = TRUE;
4232
00db133f 4233 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4234
af659722 4235 /* We've got packet with that "interactive" info
4236 dump banners, and set its prompt as ours */
4237 {
4238 char *name, *inst, *lang, *prompt;
4239 int name_len, inst_len, lang_len, prompt_len;
4240 ssh2_pkt_getstring(&name, &name_len);
4241 ssh2_pkt_getstring(&inst, &inst_len);
4242 ssh2_pkt_getstring(&lang, &lang_len);
4243 if (name_len > 0)
4244 c_write_untrusted(name, name_len);
4245 if (inst_len > 0)
4246 c_write_untrusted(inst, inst_len);
4247 num_prompts = ssh2_pkt_getuint32();
4248
4249 ssh2_pkt_getstring(&prompt, &prompt_len);
4250 strncpy(pwprompt, prompt, sizeof(pwprompt));
2c2f4dba 4251 pwprompt[prompt_len < sizeof(pwprompt) ?
4252 prompt_len : sizeof(pwprompt)-1] = '\0';
af659722 4253 need_pw = TRUE;
4254
4255 echo = ssh2_pkt_getbool();
4256 }
4257 }
4258
1408a877 4259 if (!method && can_passwd) {
4260 method = AUTH_PASSWORD;
00db133f 4261 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
32874aea 4262 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4263 savedhost);
1408a877 4264 need_pw = TRUE;
4265 }
4266
4267 if (need_pw) {
fa17a66e 4268 if (ssh_get_line) {
4269 if (!ssh_get_line(pwprompt, password,
32874aea 4270 sizeof(password), TRUE)) {
1408a877 4271 /*
fa17a66e 4272 * get_line failed to get a password (for
4273 * example because one was supplied on the
4274 * command line which has already failed to
4275 * work). Terminate.
1408a877 4276 */
2bc6a386 4277 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4278 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4279 ssh2_pkt_addstring
4280 ("No more passwords available to try");
4281 ssh2_pkt_addstring("en"); /* language tag */
4282 ssh2_pkt_send();
4283 connection_fatal("Unable to authenticate");
1408a877 4284 ssh_state = SSH_STATE_CLOSED;
4285 crReturnV;
4286 }
4287 } else {
4288 static int pos = 0;
4289 static char c;
4290
761187b6 4291 c_write_untrusted(pwprompt, strlen(pwprompt));
1408a877 4292 ssh_send_ok = 1;
4293
4294 pos = 0;
4295 while (pos >= 0) {
4296 crWaitUntilV(!ispkt);
32874aea 4297 while (inlen--)
4298 switch (c = *in++) {
4299 case 10:
4300 case 13:
4301 password[pos] = 0;
4302 pos = -1;
4303 break;
4304 case 8:
4305 case 127:
4306 if (pos > 0)
4307 pos--;
4308 break;
4309 case 21:
4310 case 27:
4311 pos = 0;
4312 break;
4313 case 3:
4314 case 4:
4315 random_save_seed();
4316 exit(0);
4317 break;
4318 default:
51b2fb65 4319 if (pos < sizeof(password)-1)
32874aea 4320 password[pos++] = c;
4321 break;
4322 }
65a22376 4323 }
1408a877 4324 c_write_str("\r\n");
65a22376 4325 }
65a22376 4326 }
65a22376 4327
1408a877 4328 if (method == AUTH_PUBLICKEY_FILE) {
4329 /*
4330 * We have our passphrase. Now try the actual authentication.
4331 */
4332 struct ssh2_userkey *key;
65a22376 4333
1408a877 4334 key = ssh2_load_userkey(cfg.keyfile, password);
4335 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4336 if (key == SSH2_WRONG_PASSPHRASE) {
4337 c_write_str("Wrong passphrase\r\n");
4338 tried_pubkey_config = FALSE;
4339 } else {
4340 c_write_str("Unable to load private key\r\n");
4341 tried_pubkey_config = TRUE;
4342 }
4343 /* Send a spurious AUTH_NONE to return to the top. */
4344 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4345 ssh2_pkt_addstring(username);
32874aea 4346 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4347 ssh2_pkt_addstring("none"); /* method */
1408a877 4348 ssh2_pkt_send();
4349 type = AUTH_TYPE_NONE;
4350 } else {
4351 unsigned char *blob, *sigdata;
4352 int blob_len, sigdata_len;
65a22376 4353
1408a877 4354 /*
4355 * We have loaded the private key and the server
4356 * has announced that it's willing to accept it.
4357 * Hallelujah. Generate a signature and send it.
4358 */
4359 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4360 ssh2_pkt_addstring(username);
32874aea 4361 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4362 ssh2_pkt_addstring("publickey"); /* method */
1408a877 4363 ssh2_pkt_addbool(TRUE);
4364 ssh2_pkt_addstring(key->alg->name);
4365 blob = key->alg->public_blob(key->data, &blob_len);
4366 ssh2_pkt_addstring_start();
4367 ssh2_pkt_addstring_data(blob, blob_len);
4368 sfree(blob);
4369
4370 /*
4371 * The data to be signed is:
4372 *
4373 * string session-id
4374 *
4375 * followed by everything so far placed in the
4376 * outgoing packet.
4377 */
4378 sigdata_len = pktout.length - 5 + 4 + 20;
4379 sigdata = smalloc(sigdata_len);
4380 PUT_32BIT(sigdata, 20);
32874aea 4381 memcpy(sigdata + 4, ssh2_session_id, 20);
4382 memcpy(sigdata + 24, pktout.data + 5,
4383 pktout.length - 5);
4384 blob =
4385 key->alg->sign(key->data, sigdata, sigdata_len,
4386 &blob_len);
1408a877 4387 ssh2_pkt_addstring_start();
4388 ssh2_pkt_addstring_data(blob, blob_len);
4389 sfree(blob);
4390 sfree(sigdata);
4391
4392 ssh2_pkt_send();
4393 type = AUTH_TYPE_PUBLICKEY;
4394 }
4395 } else if (method == AUTH_PASSWORD) {
65a22376 4396 /*
1408a877 4397 * We send the password packet lumped tightly together with
4398 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4399 * string long enough to make the total length of the two
4400 * packets constant. This should ensure that a passive
4401 * listener doing traffic analyis can't work out the length
4402 * of the password.
4403 *
4404 * For this to work, we need an assumption about the
4405 * maximum length of the password packet. I think 256 is
4406 * pretty conservative. Anyone using a password longer than
4407 * that probably doesn't have much to worry about from
4408 * people who find out how long their password is!
65a22376 4409 */
4410 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4411 ssh2_pkt_addstring(username);
32874aea 4412 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4413 ssh2_pkt_addstring("password");
4414 ssh2_pkt_addbool(FALSE);
4415 ssh2_pkt_addstring(password);
4416 ssh2_pkt_defer();
65a22376 4417 /*
1408a877 4418 * We'll include a string that's an exact multiple of the
4419 * cipher block size. If the cipher is NULL for some
4420 * reason, we don't do this trick at all because we gain
4421 * nothing by it.
65a22376 4422 */
32874aea 4423 if (cscipher) {
4424 int stringlen, i;
4425
4426 stringlen = (256 - deferred_len);
4427 stringlen += cscipher->blksize - 1;
4428 stringlen -= (stringlen % cscipher->blksize);
4429 if (cscomp) {
4430 /*
4431 * Temporarily disable actual compression,
4432 * so we can guarantee to get this string
4433 * exactly the length we want it. The
4434 * compression-disabling routine should
4435 * return an integer indicating how many
4436 * bytes we should adjust our string length
4437 * by.
4438 */
4439 stringlen -= cscomp->disable_compression();
4440 }
1408a877 4441 ssh2_pkt_init(SSH2_MSG_IGNORE);
4442 ssh2_pkt_addstring_start();
6e9e9520 4443 for (i = 0; i < stringlen; i++) {
32874aea 4444 char c = (char) random_byte();
4445 ssh2_pkt_addstring_data(&c, 1);
65a22376 4446 }
1408a877 4447 ssh2_pkt_defer();
65a22376 4448 }
39065bed 4449 ssh_pkt_defersend();
0d43337a 4450 logevent("Sent password");
1408a877 4451 type = AUTH_TYPE_PASSWORD;
761187b6 4452 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4453 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4454 ssh2_pkt_adduint32(num_prompts);
4455 ssh2_pkt_addstring(password);
4456 memset(password, 0, sizeof(password));
4457 ssh2_pkt_send();
4458 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 4459 } else {
32874aea 4460 c_write_str
4461 ("No supported authentication methods left to try!\r\n");
4462 logevent
4463 ("No supported authentications offered. Disconnecting");
1408a877 4464 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4465 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
32874aea 4466 ssh2_pkt_addstring
4467 ("No supported authentication methods available");
4468 ssh2_pkt_addstring("en"); /* language tag */
1408a877 4469 ssh2_pkt_send();
4470 ssh_state = SSH_STATE_CLOSED;
4471 crReturnV;
65a22376 4472 }
65a22376 4473 }
1408a877 4474 } while (!we_are_in);
7cca0d81 4475
4476 /*
4477 * Now we're authenticated for the connection protocol. The
4478 * connection protocol will automatically have started at this
4479 * point; there's no need to send SERVICE_REQUEST.
4480 */
4481
4482 /*
4483 * So now create a channel with a session in it.
4484 */
d2371c81 4485 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 4486 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 4487 mainchan->localid = alloc_channel_id();
7cca0d81 4488 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4489 ssh2_pkt_addstring("session");
d211621f 4490 ssh2_pkt_adduint32(mainchan->localid);
5471d09a 4491 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4492 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
32874aea 4493 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 4494 ssh2_pkt_send();
4495 crWaitUntilV(ispkt);
4496 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 4497 bombout(("Server refused to open a session"));
4498 crReturnV;
4499 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 4500 }
d211621f 4501 if (ssh2_pkt_getuint32() != mainchan->localid) {
32874aea 4502 bombout(("Server's channel confirmation cited wrong channel"));
4503 crReturnV;
7cca0d81 4504 }
d211621f 4505 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 4506 mainchan->type = CHAN_MAINSESSION;
4507 mainchan->closes = 0;
5471d09a 4508 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4509 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4510 bufchain_init(&mainchan->v.v2.outbuffer);
783415f8 4511 add234(ssh_channels, mainchan);
7cca0d81 4512 logevent("Opened channel for session");
4513
4514 /*
783415f8 4515 * Potentially enable X11 forwarding.
4516 */
4517 if (cfg.x11_forward) {
32874aea 4518 char proto[20], data[64];
4519 logevent("Requesting X11 forwarding");
4520 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4521 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4522 ssh2_pkt_adduint32(mainchan->remoteid);
4523 ssh2_pkt_addstring("x11-req");
4524 ssh2_pkt_addbool(1); /* want reply */
4525 ssh2_pkt_addbool(0); /* many connections */
4526 ssh2_pkt_addstring(proto);
4527 ssh2_pkt_addstring(data);
4528 ssh2_pkt_adduint32(0); /* screen number */
4529 ssh2_pkt_send();
4530
4531 do {
4532 crWaitUntilV(ispkt);
4533 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4534 unsigned i = ssh2_pkt_getuint32();
4535 struct ssh_channel *c;
4536 c = find234(ssh_channels, &i, ssh_channelfind);
4537 if (!c)
4538 continue; /* nonexistent channel */
5471d09a 4539 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4540 }
4541 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4542
4543 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4544 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4545 bombout(("Unexpected response to X11 forwarding request:"
4546 " packet type %d", pktin.type));
32874aea 4547 crReturnV;
4548 }
4549 logevent("X11 forwarding refused");
4550 } else {
4551 logevent("X11 forwarding enabled");
783415f8 4552 ssh_X11_fwd_enabled = TRUE;
32874aea 4553 }
783415f8 4554 }
4555
4556 /*
bc240b21 4557 * Enable port forwardings.
4558 */
4559 {
4560 static char *e; /* preserve across crReturn */
4561 char type;
4562 int n;
4563 int sport,dport;
4564 char sports[256], dports[256], host[256];
4565 char buf[1024];
4566
4567 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4568 /* Add port forwardings. */
4569 e = cfg.portfwd;
4570 while (*e) {
4571 type = *e++;
4572 n = 0;
4573 while (*e && *e != '\t')
4574 sports[n++] = *e++;
4575 sports[n] = 0;
4576 if (*e == '\t')
4577 e++;
4578 n = 0;
4579 while (*e && *e != ':')
4580 host[n++] = *e++;
4581 host[n] = 0;
4582 if (*e == ':')
4583 e++;
4584 n = 0;
4585 while (*e)
4586 dports[n++] = *e++;
4587 dports[n] = 0;
4588 e++;
4589 dport = atoi(dports);
4590 sport = atoi(sports);
4591 if (sport && dport) {
4592 if (type == 'L') {
4593 pfd_addforward(host, dport, sport);
4594 sprintf(buf, "Local port %d forwarding to %s:%d",
4595 sport, host, dport);
4596 logevent(buf);
4597 } else {
4598 struct ssh_rportfwd *pf;
4599 pf = smalloc(sizeof(*pf));
4600 strcpy(pf->dhost, host);
4601 pf->dport = dport;
4602 pf->sport = sport;
4603 if (add234(ssh_rportfwds, pf) != pf) {
4604 sprintf(buf,
95bc8819 4605 "Duplicate remote port forwarding to %s:%d",
bc240b21 4606 host, dport);
4607 logevent(buf);
4608 sfree(pf);
4609 } else {
4610 sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
4611 sport, host, dport);
4612 logevent(buf);
4613 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4614 ssh2_pkt_addstring("tcpip-forward");
4615 ssh2_pkt_addbool(1);/* want reply */
beefa433 4616 if (cfg.rport_acceptall)
4617 ssh2_pkt_addstring("0.0.0.0");
4618 else
4619 ssh2_pkt_addstring("127.0.0.1");
bc240b21 4620 ssh2_pkt_adduint32(sport);
4621 ssh2_pkt_send();
4622
4623 do {
4624 crWaitUntilV(ispkt);
4625 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4626 unsigned i = ssh2_pkt_getuint32();
4627 struct ssh_channel *c;
4628 c = find234(ssh_channels, &i, ssh_channelfind);
4629 if (!c)
4630 continue;/* nonexistent channel */
5471d09a 4631 c->v.v2.remwindow += ssh2_pkt_getuint32();
bc240b21 4632 }
4633 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4634
4635 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4636 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
c9886e66 4637 bombout(("Unexpected response to port "
4638 "forwarding request: packet type %d",
4639 pktin.type));
bc240b21 4640 crReturnV;
4641 }
4642 logevent("Server refused this port forwarding");
4643 } else {
4644 logevent("Remote port forwarding enabled");
4645 }
4646 }
4647 }
4648 }
4649 }
4650 }
4651
4652 /*
36c2a3e9 4653 * Potentially enable agent forwarding.
4654 */
4655 if (cfg.agentfwd && agent_exists()) {
32874aea 4656 logevent("Requesting OpenSSH-style agent forwarding");
4657 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4658 ssh2_pkt_adduint32(mainchan->remoteid);
4659 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4660 ssh2_pkt_addbool(1); /* want reply */
4661 ssh2_pkt_send();
4662
4663 do {
4664 crWaitUntilV(ispkt);
4665 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4666 unsigned i = ssh2_pkt_getuint32();
4667 struct ssh_channel *c;
4668 c = find234(ssh_channels, &i, ssh_channelfind);
4669 if (!c)
4670 continue; /* nonexistent channel */
5471d09a 4671 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4672 }
4673 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4674
4675 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4676 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4677 bombout(("Unexpected response to agent forwarding request:"
4678 " packet type %d", pktin.type));
32874aea 4679 crReturnV;
4680 }
4681 logevent("Agent forwarding refused");
4682 } else {
4683 logevent("Agent forwarding enabled");
36c2a3e9 4684 ssh_agentfwd_enabled = TRUE;
32874aea 4685 }
36c2a3e9 4686 }
4687
4688 /*
7cca0d81 4689 * Now allocate a pty for the session.
4690 */
67779be7 4691 if (!cfg.nopty) {
32874aea 4692 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4693 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4694 ssh2_pkt_addstring("pty-req");
4695 ssh2_pkt_addbool(1); /* want reply */
4696 ssh2_pkt_addstring(cfg.termtype);
4697 ssh2_pkt_adduint32(cols);
4698 ssh2_pkt_adduint32(rows);
4699 ssh2_pkt_adduint32(0); /* pixel width */
4700 ssh2_pkt_adduint32(0); /* pixel height */
4701 ssh2_pkt_addstring_start();
4702 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4703 ssh2_pkt_send();
4704 ssh_state = SSH_STATE_INTERMED;
4705
4706 do {
4707 crWaitUntilV(ispkt);
4708 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4709 unsigned i = ssh2_pkt_getuint32();
4710 struct ssh_channel *c;
4711 c = find234(ssh_channels, &i, ssh_channelfind);
4712 if (!c)
4713 continue; /* nonexistent channel */
5471d09a 4714 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4715 }
4716 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4717
4718 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4719 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4720 bombout(("Unexpected response to pty request:"
4721 " packet type %d", pktin.type));
32874aea 4722 crReturnV;
4723 }
4724 c_write_str("Server refused to allocate pty\r\n");
4725 ssh_editing = ssh_echoing = 1;
4726 } else {
4727 logevent("Allocated pty");
4728 }
0965bee0 4729 } else {
32874aea 4730 ssh_editing = ssh_echoing = 1;
7cca0d81 4731 }
4732
4733 /*
fd5e5847 4734 * Start a shell or a remote command. We may have to attempt
4735 * this twice if the config data has provided a second choice
4736 * of command.
7cca0d81 4737 */
fd5e5847 4738 while (1) {
4739 int subsys;
4740 char *cmd;
4741
4742 if (ssh_fallback_cmd) {
4743 subsys = cfg.ssh_subsys2;
4744 cmd = cfg.remote_cmd_ptr2;
4745 } else {
4746 subsys = cfg.ssh_subsys;
4747 cmd = cfg.remote_cmd_ptr;
4748 }
4749
4750 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4751 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4752 if (subsys) {
4753 ssh2_pkt_addstring("subsystem");
4754 ssh2_pkt_addbool(1); /* want reply */
4755 ssh2_pkt_addstring(cmd);
4756 } else if (*cmd) {
4757 ssh2_pkt_addstring("exec");
4758 ssh2_pkt_addbool(1); /* want reply */
4759 ssh2_pkt_addstring(cmd);
4760 } else {
4761 ssh2_pkt_addstring("shell");
4762 ssh2_pkt_addbool(1); /* want reply */
32874aea 4763 }
fd5e5847 4764 ssh2_pkt_send();
4765 do {
4766 crWaitUntilV(ispkt);
4767 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4768 unsigned i = ssh2_pkt_getuint32();
4769 struct ssh_channel *c;
4770 c = find234(ssh_channels, &i, ssh_channelfind);
4771 if (!c)
4772 continue; /* nonexistent channel */
4773 c->v.v2.remwindow += ssh2_pkt_getuint32();
4774 }
4775 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4776 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4777 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4778 bombout(("Unexpected response to shell/command request:"
4779 " packet type %d", pktin.type));
fd5e5847 4780 crReturnV;
4781 }
4782 /*
4783 * We failed to start the command. If this is the
4784 * fallback command, we really are finished; if it's
4785 * not, and if the fallback command exists, try falling
4786 * back to it before complaining.
4787 */
4788 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
4789 logevent("Primary command failed; attempting fallback");
4790 ssh_fallback_cmd = TRUE;
4791 continue;
4792 }
4793 bombout(("Server refused to start a shell/command"));
32874aea 4794 crReturnV;
fd5e5847 4795 } else {
4796 logevent("Started a shell/command");
32874aea 4797 }
fd5e5847 4798 break;
7cca0d81 4799 }
4800
6e48c3fe 4801 ssh_state = SSH_STATE_SESSION;
4802 if (size_needed)
4803 ssh_size();
3687d221 4804 if (eof_needed)
32874aea 4805 ssh_special(TS_EOF);
6e48c3fe 4806
7cca0d81 4807 /*
4808 * Transfer data!
4809 */
760e88b2 4810 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 4811 ssh_send_ok = 1;
7cca0d81 4812 while (1) {
32874aea 4813 static int try_send;
e5574168 4814 crReturnV;
32874aea 4815 try_send = FALSE;
7cca0d81 4816 if (ispkt) {
4817 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
32874aea 4818 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4819 char *data;
4820 int length;
4821 unsigned i = ssh2_pkt_getuint32();
4822 struct ssh_channel *c;
4823 c = find234(ssh_channels, &i, ssh_channelfind);
4824 if (!c)
4825 continue; /* nonexistent channel */
4826 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4827 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4828 continue; /* extended but not stderr */
4829 ssh2_pkt_getstring(&data, &length);
4830 if (data) {
5471d09a 4831 int bufsize;
4832 c->v.v2.locwindow -= length;
32874aea 4833 switch (c->type) {
4834 case CHAN_MAINSESSION:
5471d09a 4835 bufsize =
4836 from_backend(pktin.type ==
4837 SSH2_MSG_CHANNEL_EXTENDED_DATA,
4838 data, length);
32874aea 4839 break;
4840 case CHAN_X11:
5471d09a 4841 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 4842 break;
d74d141c 4843 case CHAN_SOCKDATA:
5471d09a 4844 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 4845 break;
36c2a3e9 4846 case CHAN_AGENT:
32874aea 4847 while (length > 0) {
4848 if (c->u.a.lensofar < 4) {
4849 int l = min(4 - c->u.a.lensofar, length);
4850 memcpy(c->u.a.msglen + c->u.a.lensofar,
4851 data, l);
4852 data += l;
4853 length -= l;
4854 c->u.a.lensofar += l;
4855 }
4856 if (c->u.a.lensofar == 4) {
4857 c->u.a.totallen =
4858 4 + GET_32BIT(c->u.a.msglen);
4859 c->u.a.message = smalloc(c->u.a.totallen);
4860 memcpy(c->u.a.message, c->u.a.msglen, 4);
4861 }
4862 if (c->u.a.lensofar >= 4 && length > 0) {
4863 int l =
4864 min(c->u.a.totallen - c->u.a.lensofar,
4865 length);
4866 memcpy(c->u.a.message + c->u.a.lensofar,
4867 data, l);
4868 data += l;
4869 length -= l;
4870 c->u.a.lensofar += l;
4871 }
4872 if (c->u.a.lensofar == c->u.a.totallen) {
4873 void *reply, *sentreply;
4874 int replylen;
4875 agent_query(c->u.a.message,
4876 c->u.a.totallen, &reply,
4877 &replylen);
4878 if (reply)
4879 sentreply = reply;
4880 else {
4881 /* Fake SSH_AGENT_FAILURE. */
4882 sentreply = "\0\0\0\1\5";
4883 replylen = 5;
4884 }
4885 ssh2_add_channel_data(c, sentreply,
4886 replylen);
36c2a3e9 4887 try_send = TRUE;
32874aea 4888 if (reply)
4889 sfree(reply);
4890 sfree(c->u.a.message);
4891 c->u.a.lensofar = 0;
4892 }
4893 }
5471d09a 4894 bufsize = 0;
32874aea 4895 break;
4896 }
4897 /*
5471d09a 4898 * If we are not buffering too much data,
4899 * enlarge the window again at the remote side.
32874aea 4900 */
5471d09a 4901 if (bufsize < OUR_V2_WINSIZE)
4902 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 4903 }
7cca0d81 4904 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
32874aea 4905 ssh_state = SSH_STATE_CLOSED;
d211621f 4906 logevent("Received disconnect message");
32874aea 4907 crReturnV;
d211621f 4908 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
32874aea 4909 unsigned i = ssh2_pkt_getuint32();
4910 struct ssh_channel *c;
4911
4912 c = find234(ssh_channels, &i, ssh_channelfind);
4913 if (!c)
4914 continue; /* nonexistent channel */
4915
4916 if (c->type == CHAN_X11) {
4917 /*
4918 * Remote EOF on an X11 channel means we should
4919 * wrap up and close the channel ourselves.
4920 */
4921 x11_close(c->u.x11.s);
4922 sshfwd_close(c);
4923 } else if (c->type == CHAN_AGENT) {
36c2a3e9 4924 sshfwd_close(c);
d74d141c 4925 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 4926 pfd_close(c->u.pfd.s);
4927 sshfwd_close(c);
36c2a3e9 4928 }
d211621f 4929 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
32874aea 4930 unsigned i = ssh2_pkt_getuint32();
4931 struct ssh_channel *c;
4932
4933 c = find234(ssh_channels, &i, ssh_channelfind);
4934 if (!c)
4935 continue; /* nonexistent channel */
32874aea 4936 /* Do pre-close processing on the channel. */
4937 switch (c->type) {
4938 case CHAN_MAINSESSION:
4939 break; /* nothing to see here, move along */
4940 case CHAN_X11:
92f157bd 4941 if (c->u.x11.s != NULL)
4942 x11_close(c->u.x11.s);
4943 sshfwd_close(c);
32874aea 4944 break;
4945 case CHAN_AGENT:
92f157bd 4946 sshfwd_close(c);
32874aea 4947 break;
d74d141c 4948 case CHAN_SOCKDATA:
92f157bd 4949 if (c->u.pfd.s != NULL)
4950 pfd_close(c->u.pfd.s);
4951 sshfwd_close(c);
bc240b21 4952 break;
32874aea 4953 }
92f157bd 4954 if (c->closes == 0) {
4955 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4956 ssh2_pkt_adduint32(c->remoteid);
4957 ssh2_pkt_send();
4958 }
32874aea 4959 del234(ssh_channels, c);
5471d09a 4960 bufchain_clear(&c->v.v2.outbuffer);
32874aea 4961 sfree(c);
4962
4963 /*
4964 * See if that was the last channel left open.
4965 */
4966 if (count234(ssh_channels) == 0) {
ca2914d1 4967#if 0
4968 /*
4969 * We used to send SSH_MSG_DISCONNECT here,
4970 * because I'd believed that _every_ conforming
4971 * SSH2 connection had to end with a disconnect
4972 * being sent by at least one side; apparently
4973 * I was wrong and it's perfectly OK to
4974 * unceremoniously slam the connection shut
4975 * when you're done, and indeed OpenSSH feels
4976 * this is more polite than sending a
4977 * DISCONNECT. So now we don't.
4978 */
32874aea 4979 logevent("All channels closed. Disconnecting");
4980 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4981 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4982 ssh2_pkt_addstring("All open channels closed");
4983 ssh2_pkt_addstring("en"); /* language tag */
4984 ssh2_pkt_send();
ca2914d1 4985#endif
32874aea 4986 ssh_state = SSH_STATE_CLOSED;
4987 crReturnV;
4988 }
4989 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 4990 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
32874aea 4991 unsigned i = ssh2_pkt_getuint32();
4992 struct ssh_channel *c;
4993 c = find234(ssh_channels, &i, ssh_channelfind);
4994 if (!c)
4995 continue; /* nonexistent channel */
5471d09a 4996 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4997 try_send = TRUE;
bc240b21 4998 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4999 unsigned i = ssh2_pkt_getuint32();
5000 struct ssh_channel *c;
5001 c = find234(ssh_channels, &i, ssh_channelfind);
5002 if (!c)
5003 continue; /* nonexistent channel */
5004 if (c->type != CHAN_SOCKDATA_DORMANT)
5005 continue; /* dunno why they're confirming this */
5006 c->remoteid = ssh2_pkt_getuint32();
5007 c->type = CHAN_SOCKDATA;
5471d09a 5008 c->v.v2.remwindow = ssh2_pkt_getuint32();
5009 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
5010 bufchain_init(&c->v.v2.outbuffer);
4ed34d25 5011 if (c->u.pfd.s)
5012 pfd_confirm(c->u.pfd.s);
5013 if (c->closes) {
5014 /*
5015 * We have a pending close on this channel,
5016 * which we decided on before the server acked
5017 * the channel open. So now we know the
5018 * remoteid, we can close it again.
5019 */
5020 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5021 ssh2_pkt_adduint32(c->remoteid);
5022 ssh2_pkt_send();
5023 }
724cface 5024 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5025 unsigned i = ssh2_pkt_getuint32();
5026 struct ssh_channel *c;
5027 c = find234(ssh_channels, &i, ssh_channelfind);
5028 if (!c)
5029 continue; /* nonexistent channel */
5030 if (c->type != CHAN_SOCKDATA_DORMANT)
5031 continue; /* dunno why they're failing this */
5032
5033 logevent("Forwarded connection refused by server");
5034
5035 pfd_close(c->u.pfd.s);
5036
5037 del234(ssh_channels, c);
5038 sfree(c);
ebb0a590 5039 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5040 unsigned localid;
5041 char *type;
5042 int typelen, want_reply;
5043 struct ssh_channel *c;
5044
5045 localid = ssh2_pkt_getuint32();
5046 ssh2_pkt_getstring(&type, &typelen);
5047 want_reply = ssh2_pkt_getbool();
5048
5049 /*
5050 * First, check that the channel exists. Otherwise,
5051 * we can instantly disconnect with a rude message.
5052 */
5053 c = find234(ssh_channels, &localid, ssh_channelfind);
5054 if (!c) {
5055 char buf[80];
5056 sprintf(buf, "Received channel request for nonexistent"
5057 " channel %d", localid);
5058 logevent(buf);
5059 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5060 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5061 ssh2_pkt_addstring(buf);
5062 ssh2_pkt_addstring("en"); /* language tag */
5063 ssh2_pkt_send();
5064 connection_fatal(buf);
5065 ssh_state = SSH_STATE_CLOSED;
5066 crReturnV;
5067 }
5068
5069 /*
d8d6c7e5 5070 * Having got the channel number, we now look at
5071 * the request type string to see if it's something
5072 * we recognise.
ebb0a590 5073 */
d8d6c7e5 5074 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5075 c == mainchan) {
5076 /* We recognise "exit-status" on the primary channel. */
5077 char buf[100];
5078 ssh_exitcode = ssh2_pkt_getuint32();
5079 sprintf(buf, "Server sent command exit status %d",
5080 ssh_exitcode);
5081 logevent(buf);
5082 if (want_reply) {
5083 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5084 ssh2_pkt_adduint32(c->remoteid);
5085 ssh2_pkt_send();
5086 }
5087 } else {
5088 /*
5089 * This is a channel request we don't know
5090 * about, so we now either ignore the request
5091 * or respond with CHANNEL_FAILURE, depending
5092 * on want_reply.
5093 */
5094 if (want_reply) {
5095 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5096 ssh2_pkt_adduint32(c->remoteid);
5097 ssh2_pkt_send();
5098 }
ebb0a590 5099 }
783415f8 5100 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5101 char *type;
5102 int typelen;
5103 char *error = NULL;
5104 struct ssh_channel *c;
bc240b21 5105 unsigned remid, winsize, pktsize;
32874aea 5106 ssh2_pkt_getstring(&type, &typelen);
5107 c = smalloc(sizeof(struct ssh_channel));
5108
bc240b21 5109 remid = ssh2_pkt_getuint32();
5110 winsize = ssh2_pkt_getuint32();
5111 pktsize = ssh2_pkt_getuint32();
5112
32874aea 5113 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5114 if (!ssh_X11_fwd_enabled)
5115 error = "X11 forwarding is not enabled";
5116 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5117 NULL) {
5118 error = "Unable to open an X11 connection";
5119 } else {
5120 c->type = CHAN_X11;
5121 }
bc240b21 5122 } else if (typelen == 15 &&
5123 !memcmp(type, "forwarded-tcpip", 15)) {
5124 struct ssh_rportfwd pf, *realpf;
5125 char *dummy;
5126 int dummylen;
5127 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5128 pf.sport = ssh2_pkt_getuint32();
5129 realpf = find234(ssh_rportfwds, &pf, NULL);
5130 if (realpf == NULL) {
5131 error = "Remote port is not recognised";
5132 } else {
5133 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5134 realpf->dport, c);
5135 char buf[1024];
5136 sprintf(buf, "Received remote port open request for %s:%d",
5137 realpf->dhost, realpf->dport);
5138 logevent(buf);
5139 if (e != NULL) {
5140 sprintf(buf, "Port open failed: %s", e);
5141 logevent(buf);
5142 error = "Port open failed";
5143 } else {
5144 logevent("Forwarded port opened successfully");
5145 c->type = CHAN_SOCKDATA;
5146 }
5147 }
32874aea 5148 } else if (typelen == 22 &&
36c2a3e9 5149 !memcmp(type, "auth-agent@openssh.com", 3)) {
32874aea 5150 if (!ssh_agentfwd_enabled)
5151 error = "Agent forwarding is not enabled";
36c2a3e9 5152 else {
32874aea 5153 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5154 c->u.a.lensofar = 0;
32874aea 5155 }
5156 } else {
5157 error = "Unsupported channel type requested";
5158 }
5159
bc240b21 5160 c->remoteid = remid;
32874aea 5161 if (error) {
5162 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5163 ssh2_pkt_adduint32(c->remoteid);
5164 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5165 ssh2_pkt_addstring(error);
5166 ssh2_pkt_addstring("en"); /* language tag */
5167 ssh2_pkt_send();
5168 sfree(c);
5169 } else {
5170 c->localid = alloc_channel_id();
5171 c->closes = 0;
5471d09a 5172 c->v.v2.locwindow = OUR_V2_WINSIZE;
5173 c->v.v2.remwindow = winsize;
5174 c->v.v2.remmaxpkt = pktsize;
5175 bufchain_init(&c->v.v2.outbuffer);
32874aea 5176 add234(ssh_channels, c);
5177 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5178 ssh2_pkt_adduint32(c->remoteid);
5179 ssh2_pkt_adduint32(c->localid);
5471d09a 5180 ssh2_pkt_adduint32(c->v.v2.locwindow);
32874aea 5181 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5182 ssh2_pkt_send();
5183 }
7cca0d81 5184 } else {
8d5de777 5185 bombout(("Strange packet received: type %d", pktin.type));
32874aea 5186 crReturnV;
7cca0d81 5187 }
5188 } else {
32874aea 5189 /*
5190 * We have spare data. Add it to the channel buffer.
5191 */
5192 ssh2_add_channel_data(mainchan, in, inlen);
5193 try_send = TRUE;
5194 }
5195 if (try_send) {
5196 int i;
5197 struct ssh_channel *c;
5198 /*
5199 * Try to send data on all channels if we can.
5200 */
5471d09a 5201 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5202 int bufsize = ssh2_try_send(c);
5203 if (bufsize == 0) {
5204 switch (c->type) {
5205 case CHAN_MAINSESSION:
5206 /* stdin need not receive an unthrottle
5207 * notification since it will be polled */
5208 break;
5209 case CHAN_X11:
5210 x11_unthrottle(c->u.x11.s);
5211 break;
5212 case CHAN_AGENT:
5213 /* agent sockets are request/response and need no
5214 * buffer management */
5215 break;
5216 case CHAN_SOCKDATA:
5217 pfd_unthrottle(c->u.pfd.s);
5218 break;
5219 }
5220 }
5221 }
7cca0d81 5222 }
e5574168 5223 }
5224
5225 crFinishV;
5226}
5227
5228/*
7cca0d81 5229 * Handle the top-level SSH2 protocol.
5230 */
5231static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5232{
5233 if (do_ssh2_transport(in, inlen, ispkt) == 0)
32874aea 5234 return;
7cca0d81 5235 do_ssh2_authconn(in, inlen, ispkt);
5236}
5237
5238/*
8df7a775 5239 * Called to set up the connection.
374330e2 5240 *
5241 * Returns an error message, or NULL on success.
374330e2 5242 */
2184a5d9 5243static char *ssh_init(char *host, int port, char **realhost, int nodelay)
32874aea 5244{
fb09bf1c 5245 char *p;
32874aea 5246
8f203108 5247#ifdef MSCRYPTOAPI
32874aea 5248 if (crypto_startup() == 0)
8f203108 5249 return "Microsoft high encryption pack not installed!";
5250#endif
374330e2 5251
8df7a775 5252 ssh_send_ok = 0;
0965bee0 5253 ssh_editing = 0;
5254 ssh_echoing = 0;
5471d09a 5255 ssh1_throttle_count = 0;
5256 ssh_overall_bufsize = 0;
fd5e5847 5257 ssh_fallback_cmd = 0;
8df7a775 5258
2184a5d9 5259 p = connect_to_host(host, port, realhost, nodelay);
fb09bf1c 5260 if (p != NULL)
5261 return p;
374330e2 5262
374330e2 5263 return NULL;
5264}
5265
5266/*
374330e2 5267 * Called to send data down the Telnet connection.
5268 */
5471d09a 5269static int ssh_send(char *buf, int len)
32874aea 5270{
f78051a1 5271 if (s == NULL || ssh_protocol == NULL)
5471d09a 5272 return 0;
374330e2 5273
5274 ssh_protocol(buf, len, 0);
5471d09a 5275
5276 return ssh_sendbuffer();
5277}
5278
5279/*
5280 * Called to query the current amount of buffered stdin data.
5281 */
5282static int ssh_sendbuffer(void)
5283{
5284 int override_value;
5285
5286 if (s == NULL || ssh_protocol == NULL)
5287 return 0;
5288
5289 /*
5290 * If the SSH socket itself has backed up, add the total backup
5291 * size on that to any individual buffer on the stdin channel.
5292 */
5293 override_value = 0;
5294 if (ssh_throttled_all)
5295 override_value = ssh_overall_bufsize;
5296
5297 if (ssh_version == 1) {
5298 return override_value;
5299 } else if (ssh_version == 2) {
5300 if (!mainchan || mainchan->closes > 0)
5301 return override_value;
5302 else
5303 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5304 }
5305
5306 return 0;
374330e2 5307}
5308
5309/*
6e48c3fe 5310 * Called to set the size of the window from SSH's POV.
374330e2 5311 */
32874aea 5312static void ssh_size(void)
5313{
374330e2 5314 switch (ssh_state) {
5315 case SSH_STATE_BEFORE_SIZE:
3687d221 5316 case SSH_STATE_PREPACKET:
21248260 5317 case SSH_STATE_CLOSED:
374330e2 5318 break; /* do nothing */
5319 case SSH_STATE_INTERMED:
5320 size_needed = TRUE; /* buffer for later */
5321 break;
5322 case SSH_STATE_SESSION:
32874aea 5323 if (!cfg.nopty) {
5324 if (ssh_version == 1) {
5325 send_packet(SSH1_CMSG_WINDOW_SIZE,
5326 PKT_INT, rows, PKT_INT, cols,
5327 PKT_INT, 0, PKT_INT, 0, PKT_END);
5328 } else {
5329 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5330 ssh2_pkt_adduint32(mainchan->remoteid);
5331 ssh2_pkt_addstring("window-change");
5332 ssh2_pkt_addbool(0);
5333 ssh2_pkt_adduint32(cols);
5334 ssh2_pkt_adduint32(rows);
5335 ssh2_pkt_adduint32(0);
5336 ssh2_pkt_adduint32(0);
5337 ssh2_pkt_send();
5338 }
5339 }
5340 break;
374330e2 5341 }
5342}
5343
5344/*
6abbf9e3 5345 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5346 * can send an EOF and collect resulting output (e.g. `plink
5347 * hostname sort').
374330e2 5348 */
32874aea 5349static void ssh_special(Telnet_Special code)
5350{
6abbf9e3 5351 if (code == TS_EOF) {
32874aea 5352 if (ssh_state != SSH_STATE_SESSION) {
5353 /*
5354 * Buffer the EOF in case we are pre-SESSION, so we can
5355 * send it as soon as we reach SESSION.
5356 */
5357 if (code == TS_EOF)
5358 eof_needed = TRUE;
5359 return;
5360 }
5361 if (ssh_version == 1) {
5362 send_packet(SSH1_CMSG_EOF, PKT_END);
5363 } else {
5364 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5365 ssh2_pkt_adduint32(mainchan->remoteid);
5366 ssh2_pkt_send();
5367 }
5368 logevent("Sent EOF message");
ec55b220 5369 } else if (code == TS_PING) {
32874aea 5370 if (ssh_state == SSH_STATE_CLOSED
5371 || ssh_state == SSH_STATE_PREPACKET) return;
5372 if (ssh_version == 1) {
5373 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5374 } else {
5375 ssh2_pkt_init(SSH2_MSG_IGNORE);
5376 ssh2_pkt_addstring_start();
5377 ssh2_pkt_send();
5378 }
6abbf9e3 5379 } else {
32874aea 5380 /* do nothing */
6abbf9e3 5381 }
374330e2 5382}
5383
d74d141c 5384void *new_sock_channel(Socket s)
5385{
5386 struct ssh_channel *c;
5387 c = smalloc(sizeof(struct ssh_channel));
5388
5389 if (c) {
bc240b21 5390 c->remoteid = -1; /* to be set when open confirmed */
d74d141c 5391 c->localid = alloc_channel_id();
5392 c->closes = 0;
bc240b21 5393 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 5394 c->u.pfd.s = s;
5395 add234(ssh_channels, c);
5396 }
5397 return c;
5398}
5399
5471d09a 5400/*
5401 * This is called when stdout/stderr (the entity to which
5402 * from_backend sends data) manages to clear some backlog.
5403 */
5404void ssh_unthrottle(int bufsize)
5405{
5406 if (ssh_version == 1) {
90347b95 5407 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5471d09a 5408 ssh1_stdout_throttling = 0;
5409 ssh1_throttle(-1);
5410 }
5411 } else {
5412 if (mainchan && mainchan->closes == 0)
5413 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5414 }
5415}
5416
d74d141c 5417void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5418{
5419 struct ssh_channel *c = (struct ssh_channel *)channel;
5420 char buf[1024];
5421
5422 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5423 logevent(buf);
5424
bc240b21 5425 if (ssh_version == 1) {
5426 send_packet(SSH1_MSG_PORT_OPEN,
5427 PKT_INT, c->localid,
5428 PKT_STR, hostname,
5429 PKT_INT, port,
5430 //PKT_STR, <org:orgport>,
5431 PKT_END);
5432 } else {
5433 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5434 ssh2_pkt_addstring("direct-tcpip");
5435 ssh2_pkt_adduint32(c->localid);
5471d09a 5436 c->v.v2.locwindow = OUR_V2_WINSIZE;
5437 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
bc240b21 5438 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5439 ssh2_pkt_addstring(hostname);
5440 ssh2_pkt_adduint32(port);
5441 /*
5442 * We make up values for the originator data; partly it's
5443 * too much hassle to keep track, and partly I'm not
5444 * convinced the server should be told details like that
5445 * about my local network configuration.
5446 */
5447 ssh2_pkt_addstring("client-side-connection");
5448 ssh2_pkt_adduint32(0);
5449 ssh2_pkt_send();
5450 }
d74d141c 5451}
5452
5453
32874aea 5454static Socket ssh_socket(void)
5455{
5456 return s;
5457}
8ccc75b0 5458
32874aea 5459static int ssh_sendok(void)
5460{
5461 return ssh_send_ok;
5462}
fb09bf1c 5463
32874aea 5464static int ssh_ldisc(int option)
5465{
5466 if (option == LD_ECHO)
5467 return ssh_echoing;
5468 if (option == LD_EDIT)
5469 return ssh_editing;
0965bee0 5470 return FALSE;
5471}
5472
d8d6c7e5 5473static int ssh_return_exitcode(void)
5474{
5475 return ssh_exitcode;
5476}
5477
374330e2 5478Backend ssh_backend = {
5479 ssh_init,
374330e2 5480 ssh_send,
5471d09a 5481 ssh_sendbuffer,
374330e2 5482 ssh_size,
4017be6d 5483 ssh_special,
8ccc75b0 5484 ssh_socket,
d8d6c7e5 5485 ssh_return_exitcode,
97db3be4 5486 ssh_sendok,
0965bee0 5487 ssh_ldisc,
5471d09a 5488 ssh_unthrottle,
97db3be4 5489 22
bc240b21 5490};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator