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[u/mdw/putty] / ssh.c
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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
247308b5 22/* logevent, only printf-formatted. */
23void logeventf(char *fmt, ...)
24{
25 va_list ap;
26 char stuff[200];
27
28 va_start(ap, fmt);
29 vsprintf(stuff, fmt, ap);
30 va_end(ap);
31 logevent(stuff);
32}
33
3cd52910 34#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
4a8fc3c4 35 (s ? sk_close(s), s = NULL : 0), \
247308b5 36 logeventf msg, connection_fatal msg )
8d5de777 37
32874aea 38#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
39#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
40#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
41#define SSH1_CMSG_USER 4 /* 0x4 */
42#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
43#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
44#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
45#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
46#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
47#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
48#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
49#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
50#define SSH1_SMSG_SUCCESS 14 /* 0xe */
51#define SSH1_SMSG_FAILURE 15 /* 0xf */
52#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
53#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
54#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
55#define SSH1_CMSG_EOF 19 /* 0x13 */
56#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
57#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
58#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
59#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
60#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
61#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
62#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
63#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
64#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
65#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
66#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
67#define SSH1_MSG_IGNORE 32 /* 0x20 */
68#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
69#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
70#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
71#define SSH1_MSG_DEBUG 36 /* 0x24 */
72#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
73#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
74#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
75#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
76#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
77#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
78#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
79
80#define SSH1_AUTH_TIS 5 /* 0x5 */
81#define SSH1_AUTH_CCARD 16 /* 0x10 */
82
83#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 84/* Mask for protoflags we will echo back to server if seen */
32874aea 85#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
86
87#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
88#define SSH2_MSG_IGNORE 2 /* 0x2 */
89#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
90#define SSH2_MSG_DEBUG 4 /* 0x4 */
91#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
92#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
93#define SSH2_MSG_KEXINIT 20 /* 0x14 */
94#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
95#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
96#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
97#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
98#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
99#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
100#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
101#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
102#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
103#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
104#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
105#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
106#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 107#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
108#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 109#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
110#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
111#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
112#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
113#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
114#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
115#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
116#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
117#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
118#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
119#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
120#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
121#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
122#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
123
00db133f 124/*
125 * Packet type contexts, so that ssh2_pkt_type can correctly decode
126 * the ambiguous type numbers back into the correct type strings.
127 */
128#define SSH2_PKTCTX_DHGROUP1 0x0001
129#define SSH2_PKTCTX_DHGEX 0x0002
130#define SSH2_PKTCTX_PUBLICKEY 0x0010
131#define SSH2_PKTCTX_PASSWORD 0x0020
132#define SSH2_PKTCTX_KBDINTER 0x0040
133#define SSH2_PKTCTX_AUTH_MASK 0x00F0
134
32874aea 135#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
136#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
137#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
138#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
139#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
140#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
141#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
142#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
143#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
144#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
145#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
146#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
147#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
148#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
149#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 150
151static const char *const ssh2_disconnect_reasons[] = {
152 NULL,
153 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
154 "SSH_DISCONNECT_PROTOCOL_ERROR",
155 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
156 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
157 "SSH_DISCONNECT_MAC_ERROR",
158 "SSH_DISCONNECT_COMPRESSION_ERROR",
159 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
160 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
161 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
162 "SSH_DISCONNECT_CONNECTION_LOST",
163 "SSH_DISCONNECT_BY_APPLICATION",
164 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
165 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
166 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
167 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
168};
9005f3ba 169
32874aea 170#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
171#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
172#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
173#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 174
32874aea 175#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 176
7d503c31 177/*
178 * Various remote-bug flags.
179 */
180#define BUG_CHOKES_ON_SSH1_IGNORE 1
181#define BUG_SSH2_HMAC 2
bd358db1 182#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 183#define BUG_CHOKES_ON_RSA 8
1dd353b5 184#define BUG_SSH2_RSA_PADDING 16
088bde77 185#define BUG_SSH2_DERIVEKEY 32
8e975795 186#define BUG_SSH2_DH_GEX 64
bd358db1 187
00db133f 188static int ssh_pkt_ctx = 0;
189
190#define translate(x) if (type == x) return #x
191#define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
192char *ssh1_pkt_type(int type)
193{
194 translate(SSH1_MSG_DISCONNECT);
195 translate(SSH1_SMSG_PUBLIC_KEY);
196 translate(SSH1_CMSG_SESSION_KEY);
197 translate(SSH1_CMSG_USER);
198 translate(SSH1_CMSG_AUTH_RSA);
199 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
200 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
201 translate(SSH1_CMSG_AUTH_PASSWORD);
202 translate(SSH1_CMSG_REQUEST_PTY);
203 translate(SSH1_CMSG_WINDOW_SIZE);
204 translate(SSH1_CMSG_EXEC_SHELL);
205 translate(SSH1_CMSG_EXEC_CMD);
206 translate(SSH1_SMSG_SUCCESS);
207 translate(SSH1_SMSG_FAILURE);
208 translate(SSH1_CMSG_STDIN_DATA);
209 translate(SSH1_SMSG_STDOUT_DATA);
210 translate(SSH1_SMSG_STDERR_DATA);
211 translate(SSH1_CMSG_EOF);
212 translate(SSH1_SMSG_EXIT_STATUS);
213 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
214 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
215 translate(SSH1_MSG_CHANNEL_DATA);
216 translate(SSH1_MSG_CHANNEL_CLOSE);
217 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
218 translate(SSH1_SMSG_X11_OPEN);
219 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
220 translate(SSH1_MSG_PORT_OPEN);
221 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
222 translate(SSH1_SMSG_AGENT_OPEN);
223 translate(SSH1_MSG_IGNORE);
224 translate(SSH1_CMSG_EXIT_CONFIRMATION);
225 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
226 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
227 translate(SSH1_MSG_DEBUG);
228 translate(SSH1_CMSG_REQUEST_COMPRESSION);
229 translate(SSH1_CMSG_AUTH_TIS);
230 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
231 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
232 translate(SSH1_CMSG_AUTH_CCARD);
233 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
234 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
235 return "unknown";
236}
237char *ssh2_pkt_type(int type)
238{
239 translate(SSH2_MSG_DISCONNECT);
240 translate(SSH2_MSG_IGNORE);
241 translate(SSH2_MSG_UNIMPLEMENTED);
242 translate(SSH2_MSG_DEBUG);
243 translate(SSH2_MSG_SERVICE_REQUEST);
244 translate(SSH2_MSG_SERVICE_ACCEPT);
245 translate(SSH2_MSG_KEXINIT);
246 translate(SSH2_MSG_NEWKEYS);
247 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
248 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
249 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
250 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
251 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
252 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
253 translate(SSH2_MSG_USERAUTH_REQUEST);
254 translate(SSH2_MSG_USERAUTH_FAILURE);
255 translate(SSH2_MSG_USERAUTH_SUCCESS);
256 translate(SSH2_MSG_USERAUTH_BANNER);
257 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
258 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
259 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
260 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
261 translate(SSH2_MSG_GLOBAL_REQUEST);
262 translate(SSH2_MSG_REQUEST_SUCCESS);
263 translate(SSH2_MSG_REQUEST_FAILURE);
264 translate(SSH2_MSG_CHANNEL_OPEN);
265 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
266 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
267 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
268 translate(SSH2_MSG_CHANNEL_DATA);
269 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
270 translate(SSH2_MSG_CHANNEL_EOF);
271 translate(SSH2_MSG_CHANNEL_CLOSE);
272 translate(SSH2_MSG_CHANNEL_REQUEST);
273 translate(SSH2_MSG_CHANNEL_SUCCESS);
274 translate(SSH2_MSG_CHANNEL_FAILURE);
275 return "unknown";
276}
277#undef translate
278#undef translatec
7d503c31 279
fb09bf1c 280#define GET_32BIT(cp) \
281 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
282 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
283 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
284 ((unsigned long)(unsigned char)(cp)[3]))
285
286#define PUT_32BIT(cp, value) { \
287 (cp)[0] = (unsigned char)((value) >> 24); \
288 (cp)[1] = (unsigned char)((value) >> 16); \
289 (cp)[2] = (unsigned char)((value) >> 8); \
290 (cp)[3] = (unsigned char)(value); }
291
7cca0d81 292enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 293
374330e2 294/* Coroutine mechanics for the sillier bits of the code */
295#define crBegin1 static int crLine = 0;
296#define crBegin2 switch(crLine) { case 0:;
297#define crBegin crBegin1; crBegin2;
298#define crFinish(z) } crLine = 0; return (z)
299#define crFinishV } crLine = 0; return
300#define crReturn(z) \
301 do {\
302 crLine=__LINE__; return (z); case __LINE__:;\
303 } while (0)
304#define crReturnV \
305 do {\
306 crLine=__LINE__; return; case __LINE__:;\
307 } while (0)
308#define crStop(z) do{ crLine = 0; return (z); }while(0)
309#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 310#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 311#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 312
32874aea 313extern char *x11_init(Socket *, char *, void *);
314extern void x11_close(Socket);
5471d09a 315extern int x11_send(Socket, char *, int);
9c964e85 316extern void x11_invent_auth(char *, int, char *, int);
5471d09a 317extern void x11_unthrottle(Socket s);
318extern void x11_override_throttle(Socket s, int enable);
9c964e85 319
d74d141c 320extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
321extern char *pfd_addforward(char *desthost, int destport, int port);
322extern void pfd_close(Socket s);
5471d09a 323extern int pfd_send(Socket s, char *data, int len);
d74d141c 324extern void pfd_confirm(Socket s);
5471d09a 325extern void pfd_unthrottle(Socket s);
326extern void pfd_override_throttle(Socket s, int enable);
327
3d63ca2e 328static void ssh2_pkt_init(int pkt_type);
329static void ssh2_pkt_addbool(unsigned char value);
330static void ssh2_pkt_adduint32(unsigned long value);
331static void ssh2_pkt_addstring_start(void);
332static void ssh2_pkt_addstring_str(char *data);
333static void ssh2_pkt_addstring_data(char *data, int len);
334static void ssh2_pkt_addstring(char *data);
335static char *ssh2_mpint_fmt(Bignum b, int *len);
336static void ssh2_pkt_addmp(Bignum b);
337static int ssh2_pkt_construct(void);
338static void ssh2_pkt_send(void);
339
5471d09a 340/*
341 * Buffer management constants. There are several of these for
342 * various different purposes:
343 *
344 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
345 * on a local data stream before we throttle the whole SSH
346 * connection (in SSH1 only). Throttling the whole connection is
347 * pretty drastic so we set this high in the hope it won't
348 * happen very often.
349 *
350 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
351 * on the SSH connection itself before we defensively throttle
352 * _all_ local data streams. This is pretty drastic too (though
353 * thankfully unlikely in SSH2 since the window mechanism should
354 * ensure that the server never has any need to throttle its end
355 * of the connection), so we set this high as well.
356 *
357 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
358 * channels.
359 */
360
361#define SSH1_BUFFER_LIMIT 32768
362#define SSH_MAX_BACKLOG 32768
363#define OUR_V2_WINSIZE 16384
d74d141c 364
a92dd380 365const static struct ssh_kex *kex_algs[] = {
a92dd380 366 &ssh_diffiehellman_gex,
32874aea 367 &ssh_diffiehellman
368};
e5574168 369
85cc02bb 370const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 371
32874aea 372static void nullmac_key(unsigned char *key)
373{
374}
375static void nullmac_generate(unsigned char *blk, int len,
376 unsigned long seq)
377{
378}
379static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
380{
381 return 1;
382}
57476f6b 383const static struct ssh_mac ssh_mac_none = {
d39f364a 384 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 385};
8b2715b2 386const static struct ssh_mac *macs[] = {
32874aea 387 &ssh_sha1, &ssh_md5, &ssh_mac_none
388};
8b2715b2 389const static struct ssh_mac *buggymacs[] = {
32874aea 390 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
391};
e5574168 392
32874aea 393static void ssh_comp_none_init(void)
394{
395}
4ba9b64b 396static int ssh_comp_none_block(unsigned char *block, int len,
32874aea 397 unsigned char **outblock, int *outlen)
398{
399 return 0;
400}
401static int ssh_comp_none_disable(void)
402{
4ba9b64b 403 return 0;
404}
57476f6b 405const static struct ssh_compress ssh_comp_none = {
4ba9b64b 406 "none",
407 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 408 ssh_comp_none_init, ssh_comp_none_block,
409 ssh_comp_none_disable
e5574168 410};
4ba9b64b 411extern const struct ssh_compress ssh_zlib;
412const static struct ssh_compress *compressions[] = {
32874aea 413 &ssh_zlib, &ssh_comp_none
414};
374330e2 415
32874aea 416enum { /* channel types */
783415f8 417 CHAN_MAINSESSION,
418 CHAN_X11,
419 CHAN_AGENT,
bc240b21 420 CHAN_SOCKDATA,
421 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 422};
423
dacbd0e8 424/*
425 * 2-3-4 tree storing channels.
426 */
427struct ssh_channel {
d211621f 428 unsigned remoteid, localid;
dacbd0e8 429 int type;
0357890f 430 /*
431 * In SSH1, this value contains four bits:
432 *
433 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
434 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
435 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
436 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
437 *
438 * A channel is completely finished with when all four bits are set.
439 */
dacbd0e8 440 int closes;
5471d09a 441 union {
442 struct ssh1_data_channel {
443 int throttling;
444 } v1;
445 struct ssh2_data_channel {
446 bufchain outbuffer;
447 unsigned remwindow, remmaxpkt;
448 unsigned locwindow;
449 } v2;
450 } v;
dacbd0e8 451 union {
32874aea 452 struct ssh_agent_channel {
453 unsigned char *message;
454 unsigned char msglen[4];
455 int lensofar, totallen;
456 } a;
457 struct ssh_x11_channel {
458 Socket s;
459 } x11;
d74d141c 460 struct ssh_pfd_channel {
461 Socket s;
462 } pfd;
dacbd0e8 463 } u;
464};
57476f6b 465
d74d141c 466/*
bc240b21 467 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
468 * 2 use this structure in different ways, reflecting SSH 2's
469 * altogether saner approach to port forwarding.
470 *
471 * In SSH 1, you arrange a remote forwarding by sending the server
472 * the remote port number, and the local destination host:port.
473 * When a connection comes in, the server sends you back that
474 * host:port pair, and you connect to it. This is a ready-made
475 * security hole if you're not on the ball: a malicious server
476 * could send you back _any_ host:port pair, so if you trustingly
477 * connect to the address it gives you then you've just opened the
478 * entire inside of your corporate network just by connecting
479 * through it to a dodgy SSH server. Hence, we must store a list of
480 * host:port pairs we _are_ trying to forward to, and reject a
481 * connection request from the server if it's not in the list.
482 *
483 * In SSH 2, each side of the connection minds its own business and
484 * doesn't send unnecessary information to the other. You arrange a
485 * remote forwarding by sending the server just the remote port
486 * number. When a connection comes in, the server tells you which
487 * of its ports was connected to; and _you_ have to remember what
488 * local host:port pair went with that port number.
489 *
490 * Hence: in SSH 1 this structure stores host:port pairs we intend
491 * to allow connections to, and is indexed by those host:port
492 * pairs. In SSH 2 it stores a mapping from source port to
493 * destination host:port pair, and is indexed by source port.
d74d141c 494 */
495struct ssh_rportfwd {
bc240b21 496 unsigned sport, dport;
497 char dhost[256];
d74d141c 498};
499
57476f6b 500struct Packet {
501 long length;
502 int type;
503 unsigned char *data;
504 unsigned char *body;
505 long savedpos;
506 long maxlen;
507};
508
0db56f73 509static SHA_State exhash, exhashbase;
57476f6b 510
8df7a775 511static Socket s = NULL;
57476f6b 512
513static unsigned char session_key[32];
4ba9b64b 514static int ssh1_compressing;
b96dc54c 515static int ssh1_remote_protoflags;
516static int ssh1_local_protoflags;
db7d555c 517static int ssh_agentfwd_enabled;
9c964e85 518static int ssh_X11_fwd_enabled;
7d503c31 519static int ssh_remote_bugs;
57476f6b 520static const struct ssh_cipher *cipher = NULL;
0a3f1d48 521static const struct ssh2_cipher *cscipher = NULL;
522static const struct ssh2_cipher *sccipher = NULL;
57476f6b 523static const struct ssh_mac *csmac = NULL;
524static const struct ssh_mac *scmac = NULL;
525static const struct ssh_compress *cscomp = NULL;
526static const struct ssh_compress *sccomp = NULL;
527static const struct ssh_kex *kex = NULL;
e055a386 528static const struct ssh_signkey *hostkey = NULL;
65a22376 529static unsigned char ssh2_session_id[20];
57476f6b 530
531static char *savedhost;
532static int savedport;
533static int ssh_send_ok;
0965bee0 534static int ssh_echoing, ssh_editing;
57476f6b 535
32874aea 536static tree234 *ssh_channels; /* indexed by local id */
57476f6b 537static struct ssh_channel *mainchan; /* primary session channel */
d8d6c7e5 538static int ssh_exitcode = -1;
57476f6b 539
d74d141c 540static tree234 *ssh_rportfwds;
541
57476f6b 542static enum {
3687d221 543 SSH_STATE_PREPACKET,
57476f6b 544 SSH_STATE_BEFORE_SIZE,
545 SSH_STATE_INTERMED,
546 SSH_STATE_SESSION,
547 SSH_STATE_CLOSED
3687d221 548} ssh_state = SSH_STATE_PREPACKET;
57476f6b 549
3687d221 550static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 551
552static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
553static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 554static unsigned char *deferred_send_data = NULL;
555static int deferred_len = 0, deferred_size = 0;
57476f6b 556
fd5e5847 557/*
558 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
559 * that fails. This variable is the means by which scp.c can reach
560 * into the SSH code and find out which one it got.
561 */
562int ssh_fallback_cmd = 0;
563
57476f6b 564static int ssh_version;
5471d09a 565static int ssh1_throttle_count;
566static int ssh_overall_bufsize;
567static int ssh_throttled_all;
568static int ssh1_stdout_throttling;
32874aea 569static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
57476f6b 570static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
571static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
572static void ssh_size(void);
32874aea 573static void ssh_special(Telnet_Special);
5471d09a 574static int ssh2_try_send(struct ssh_channel *c);
32874aea 575static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
576 int len);
5471d09a 577static void ssh_throttle_all(int enable, int bufsize);
578static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
32874aea 579static int (*s_rdpkt) (unsigned char **data, int *datalen);
5471d09a 580static int ssh_sendbuffer(void);
57476f6b 581
582static struct rdpkt1_state_tag {
583 long len, pad, biglen, to_read;
584 unsigned long realcrc, gotcrc;
585 unsigned char *p;
586 int i;
587 int chunk;
588} rdpkt1_state;
589
960e736a 590static struct rdpkt2_state_tag {
591 long len, pad, payload, packetlen, maclen;
592 int i;
593 int cipherblk;
594 unsigned long incoming_sequence;
595} rdpkt2_state;
596
32874aea 597static int ssh_channelcmp(void *av, void *bv)
598{
599 struct ssh_channel *a = (struct ssh_channel *) av;
600 struct ssh_channel *b = (struct ssh_channel *) bv;
601 if (a->localid < b->localid)
602 return -1;
603 if (a->localid > b->localid)
604 return +1;
dacbd0e8 605 return 0;
606}
32874aea 607static int ssh_channelfind(void *av, void *bv)
608{
609 unsigned *a = (unsigned *) av;
610 struct ssh_channel *b = (struct ssh_channel *) bv;
611 if (*a < b->localid)
612 return -1;
613 if (*a > b->localid)
614 return +1;
dacbd0e8 615 return 0;
616}
617
bc240b21 618static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 619{
620 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
621 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
622 int i;
bc240b21 623 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 624 return i < 0 ? -1 : +1;
bc240b21 625 if (a->dport > b->dport)
626 return +1;
627 if (a->dport < b->dport)
628 return -1;
629 return 0;
630}
631
632static int ssh_rportcmp_ssh2(void *av, void *bv)
633{
634 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
635 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 636
bc240b21 637 if (a->sport > b->sport)
d74d141c 638 return +1;
bc240b21 639 if (a->sport < b->sport)
640 return -1;
d74d141c 641 return 0;
642}
643
32874aea 644static int alloc_channel_id(void)
645{
260f3dec 646 const unsigned CHANNEL_NUMBER_OFFSET = 256;
647 unsigned low, high, mid;
d2371c81 648 int tsize;
649 struct ssh_channel *c;
650
651 /*
652 * First-fit allocation of channel numbers: always pick the
653 * lowest unused one. To do this, binary-search using the
654 * counted B-tree to find the largest channel ID which is in a
655 * contiguous sequence from the beginning. (Precisely
656 * everything in that sequence must have ID equal to its tree
657 * index plus CHANNEL_NUMBER_OFFSET.)
658 */
659 tsize = count234(ssh_channels);
660
32874aea 661 low = -1;
662 high = tsize;
d2371c81 663 while (high - low > 1) {
664 mid = (high + low) / 2;
665 c = index234(ssh_channels, mid);
666 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
667 low = mid; /* this one is fine */
668 else
669 high = mid; /* this one is past it */
670 }
671 /*
672 * Now low points to either -1, or the tree index of the
673 * largest ID in the initial sequence.
674 */
675 {
676 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
677 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
678 }
679 return low + 1 + CHANNEL_NUMBER_OFFSET;
680}
681
32874aea 682static void c_write(char *buf, int len)
683{
67779be7 684 if ((flags & FLAG_STDERR)) {
32874aea 685 int i;
686 for (i = 0; i < len; i++)
687 if (buf[i] != '\r')
688 fputc(buf[i], stderr);
fb09bf1c 689 return;
690 }
fe50e814 691 from_backend(1, buf, len);
3bdaf79d 692}
693
32874aea 694static void c_write_untrusted(char *buf, int len)
695{
a209e957 696 int i;
697 for (i = 0; i < len; i++) {
32874aea 698 if (buf[i] == '\n')
699 c_write("\r\n", 2);
700 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
701 c_write(buf + i, 1);
a209e957 702 }
703}
704
32874aea 705static void c_write_str(char *buf)
706{
1408a877 707 c_write(buf, strlen(buf));
708}
709
fb09bf1c 710/*
711 * Collect incoming data in the incoming packet buffer.
e5574168 712 * Decipher and verify the packet when it is completely read.
713 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 714 * Update the *data and *datalen variables.
715 * Return the additional nr of bytes needed, or 0 when
716 * a complete packet is available.
717 */
e5574168 718static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 719{
57476f6b 720 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 721
722 crBegin;
374330e2 723
32874aea 724 next_packet:
37508af4 725
fb09bf1c 726 pktin.type = 0;
727 pktin.length = 0;
374330e2 728
57476f6b 729 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 730 while ((*datalen) == 0)
32874aea 731 crReturn(4 - st->i);
57476f6b 732 st->len = (st->len << 8) + **data;
fb09bf1c 733 (*data)++, (*datalen)--;
734 }
374330e2 735
57476f6b 736 st->pad = 8 - (st->len % 8);
737 st->biglen = st->len + st->pad;
738 pktin.length = st->len - 5;
fb09bf1c 739
57476f6b 740 if (pktin.maxlen < st->biglen) {
741 pktin.maxlen = st->biglen;
32874aea 742 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
743 srealloc(pktin.data, st->biglen + APIEXTRA));
fb09bf1c 744 if (!pktin.data)
745 fatalbox("Out of memory");
746 }
374330e2 747
57476f6b 748 st->to_read = st->biglen;
749 st->p = pktin.data;
750 while (st->to_read > 0) {
32874aea 751 st->chunk = st->to_read;
fb09bf1c 752 while ((*datalen) == 0)
57476f6b 753 crReturn(st->to_read);
754 if (st->chunk > (*datalen))
755 st->chunk = (*datalen);
756 memcpy(st->p, *data, st->chunk);
757 *data += st->chunk;
758 *datalen -= st->chunk;
759 st->p += st->chunk;
760 st->to_read -= st->chunk;
fb09bf1c 761 }
374330e2 762
9a3a93a5 763 if (cipher && detect_attack(pktin.data, st->biglen, NULL)) {
764 bombout(("Network attack (CRC compensation) detected!"));
765 crReturn(0);
766 }
767
fb09bf1c 768 if (cipher)
57476f6b 769 cipher->decrypt(pktin.data, st->biglen);
374330e2 770
32874aea 771 st->realcrc = crc32(pktin.data, st->biglen - 4);
772 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
57476f6b 773 if (st->gotcrc != st->realcrc) {
8d5de777 774 bombout(("Incorrect CRC received on packet"));
32874aea 775 crReturn(0);
fb09bf1c 776 }
572f871e 777
4ba9b64b 778 pktin.body = pktin.data + st->pad + 1;
779
780 if (ssh1_compressing) {
781 unsigned char *decompblk;
782 int decomplen;
32874aea 783 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
4ba9b64b 784 &decompblk, &decomplen);
785
786 if (pktin.maxlen < st->pad + decomplen) {
787 pktin.maxlen = st->pad + decomplen;
32874aea 788 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
789 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 790 if (!pktin.data)
791 fatalbox("Out of memory");
792 }
793
32874aea 794 memcpy(pktin.body - 1, decompblk, decomplen);
dcbde236 795 sfree(decompblk);
32874aea 796 pktin.length = decomplen - 1;
4ba9b64b 797 }
798
00db133f 799 pktin.type = pktin.body[-1];
800
801 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
802 pktin.body, pktin.length);
803
e5574168 804 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 805 pktin.type == SSH1_SMSG_STDERR_DATA ||
806 pktin.type == SSH1_MSG_DEBUG ||
807 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
808 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3d63ca2e 809 long stringlen = GET_32BIT(pktin.body);
810 if (stringlen + 4 != pktin.length) {
8d5de777 811 bombout(("Received data packet with bogus string length"));
32874aea 812 crReturn(0);
813 }
fb09bf1c 814 }
815
e5574168 816 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 817 /* log debug message */
eb4504cc 818 char buf[512];
3d63ca2e 819 int stringlen = GET_32BIT(pktin.body);
eb4504cc 820 strcpy(buf, "Remote debug message: ");
821 if (stringlen > 480)
822 stringlen = 480;
3d63ca2e 823 memcpy(buf + 8, pktin.body + 4, stringlen);
824 buf[8 + stringlen] = '\0';
fb09bf1c 825 logevent(buf);
826 goto next_packet;
e5574168 827 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 828 /* do nothing */
829 goto next_packet;
830 }
831
38c4a8da 832 if (pktin.type == SSH1_MSG_DISCONNECT) {
833 /* log reason code in disconnect message */
834 char buf[256];
260f3dec 835 unsigned msglen = GET_32BIT(pktin.body);
836 unsigned nowlen;
38c4a8da 837 strcpy(buf, "Remote sent disconnect: ");
838 nowlen = strlen(buf);
32874aea 839 if (msglen > sizeof(buf) - nowlen - 1)
840 msglen = sizeof(buf) - nowlen - 1;
841 memcpy(buf + nowlen, pktin.body + 4, msglen);
842 buf[nowlen + msglen] = '\0';
247308b5 843 /* logevent(buf); (this is now done within the bombout macro) */
4eb195cc 844 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 845 crReturn(0);
38c4a8da 846 }
847
fb09bf1c 848 crFinish(0);
849}
850
e5574168 851static int ssh2_rdpkt(unsigned char **data, int *datalen)
852{
960e736a 853 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 854
855 crBegin;
856
32874aea 857 next_packet:
e5574168 858 pktin.type = 0;
859 pktin.length = 0;
960e736a 860 if (sccipher)
32874aea 861 st->cipherblk = sccipher->blksize;
e5574168 862 else
32874aea 863 st->cipherblk = 8;
960e736a 864 if (st->cipherblk < 8)
32874aea 865 st->cipherblk = 8;
960e736a 866
867 if (pktin.maxlen < st->cipherblk) {
868 pktin.maxlen = st->cipherblk;
32874aea 869 pktin.data =
870 (pktin.data ==
871 NULL ? smalloc(st->cipherblk +
872 APIEXTRA) : srealloc(pktin.data,
873 st->cipherblk +
874 APIEXTRA));
e5574168 875 if (!pktin.data)
876 fatalbox("Out of memory");
877 }
878
879 /*
880 * Acquire and decrypt the first block of the packet. This will
881 * contain the length and padding details.
882 */
32874aea 883 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 884 while ((*datalen) == 0)
32874aea 885 crReturn(st->cipherblk - st->i);
960e736a 886 pktin.data[st->i] = *(*data)++;
32874aea 887 (*datalen)--;
e5574168 888 }
4252c9cc 889
e5574168 890 if (sccipher)
32874aea 891 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 892
893 /*
894 * Now get the length and padding figures.
895 */
960e736a 896 st->len = GET_32BIT(pktin.data);
897 st->pad = pktin.data[4];
e5574168 898
899 /*
717dc483 900 * _Completely_ silly lengths should be stomped on before they
901 * do us any more damage.
902 */
903 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
904 bombout(("Incoming packet was garbled on decryption"));
905 crReturn(0);
906 }
907
908 /*
e5574168 909 * This enables us to deduce the payload length.
910 */
960e736a 911 st->payload = st->len - st->pad - 1;
e5574168 912
960e736a 913 pktin.length = st->payload + 5;
e5574168 914
915 /*
916 * So now we can work out the total packet length.
917 */
960e736a 918 st->packetlen = st->len + 4;
919 st->maclen = scmac ? scmac->len : 0;
e5574168 920
921 /*
922 * Adjust memory allocation if packet is too big.
923 */
32874aea 924 if (pktin.maxlen < st->packetlen + st->maclen) {
925 pktin.maxlen = st->packetlen + st->maclen;
926 pktin.data =
927 (pktin.data ==
928 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
929 pktin.maxlen
930 +
931 APIEXTRA));
e5574168 932 if (!pktin.data)
933 fatalbox("Out of memory");
934 }
935
936 /*
937 * Read and decrypt the remainder of the packet.
938 */
32874aea 939 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
940 st->i++) {
e5574168 941 while ((*datalen) == 0)
960e736a 942 crReturn(st->packetlen + st->maclen - st->i);
943 pktin.data[st->i] = *(*data)++;
32874aea 944 (*datalen)--;
e5574168 945 }
946 /* Decrypt everything _except_ the MAC. */
947 if (sccipher)
32874aea 948 sccipher->decrypt(pktin.data + st->cipherblk,
949 st->packetlen - st->cipherblk);
e5574168 950
951 /*
952 * Check the MAC.
953 */
32874aea 954 if (scmac
955 && !scmac->verify(pktin.data, st->len + 4,
956 st->incoming_sequence)) {
8d5de777 957 bombout(("Incorrect MAC received on packet"));
32874aea 958 crReturn(0);
8d5de777 959 }
32874aea 960 st->incoming_sequence++; /* whether or not we MACed */
e5574168 961
4ba9b64b 962 /*
963 * Decompress packet payload.
964 */
965 {
966 unsigned char *newpayload;
967 int newlen;
32874aea 968 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
4ba9b64b 969 &newpayload, &newlen)) {
32874aea 970 if (pktin.maxlen < newlen + 5) {
971 pktin.maxlen = newlen + 5;
972 pktin.data =
973 (pktin.data ==
974 NULL ? smalloc(pktin.maxlen +
975 APIEXTRA) : srealloc(pktin.data,
976 pktin.maxlen +
977 APIEXTRA));
4ba9b64b 978 if (!pktin.data)
979 fatalbox("Out of memory");
980 }
981 pktin.length = 5 + newlen;
32874aea 982 memcpy(pktin.data + 5, newpayload, newlen);
dcbde236 983 sfree(newpayload);
4ba9b64b 984 }
985 }
986
e5574168 987 pktin.savedpos = 6;
988 pktin.type = pktin.data[5];
e5574168 989
00db133f 990 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
991 pktin.data+6, pktin.length-6);
992
3d63ca2e 993 switch (pktin.type) {
994 /*
995 * These packets we must handle instantly.
996 */
997 case SSH2_MSG_DISCONNECT:
998 {
999 /* log reason code in disconnect message */
1000 char buf[256];
1001 int reason = GET_32BIT(pktin.data + 6);
1002 unsigned msglen = GET_32BIT(pktin.data + 10);
1003 unsigned nowlen;
1004 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1005 sprintf(buf, "Received disconnect message (%s)",
1006 ssh2_disconnect_reasons[reason]);
1007 } else {
1008 sprintf(buf, "Received disconnect message (unknown type %d)",
1009 reason);
1010 }
1011 logevent(buf);
1012 strcpy(buf, "Disconnection message text: ");
1013 nowlen = strlen(buf);
1014 if (msglen > sizeof(buf) - nowlen - 1)
1015 msglen = sizeof(buf) - nowlen - 1;
1016 memcpy(buf + nowlen, pktin.data + 14, msglen);
1017 buf[nowlen + msglen] = '\0';
1018 logevent(buf);
1019 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1020 reason,
1021 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1022 ssh2_disconnect_reasons[reason] : "unknown",
1023 buf+nowlen));
1024 crReturn(0);
1025 }
1026 break;
1027 case SSH2_MSG_IGNORE:
1028 goto next_packet;
1029 case SSH2_MSG_DEBUG:
1030 {
1031 /* log the debug message */
1032 char buf[512];
1033 /* int display = pktin.body[6]; */
1034 int stringlen = GET_32BIT(pktin.data+7);
1035 int prefix;
1036 strcpy(buf, "Remote debug message: ");
1037 prefix = strlen(buf);
1038 if (stringlen > sizeof(buf)-prefix-1)
1039 stringlen = sizeof(buf)-prefix-1;
1040 memcpy(buf + prefix, pktin.data + 11, stringlen);
1041 buf[prefix + stringlen] = '\0';
1042 logevent(buf);
38c4a8da 1043 }
3d63ca2e 1044 goto next_packet; /* FIXME: print the debug message */
1045
1046 /*
1047 * These packets we need do nothing about here.
1048 */
1049 case SSH2_MSG_UNIMPLEMENTED:
1050 case SSH2_MSG_SERVICE_REQUEST:
1051 case SSH2_MSG_SERVICE_ACCEPT:
1052 case SSH2_MSG_KEXINIT:
1053 case SSH2_MSG_NEWKEYS:
1054 case SSH2_MSG_KEXDH_INIT:
1055 case SSH2_MSG_KEXDH_REPLY:
1056 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1057 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1058 case SSH2_MSG_KEX_DH_GEX_INIT:
1059 case SSH2_MSG_KEX_DH_GEX_REPLY:
1060 case SSH2_MSG_USERAUTH_REQUEST:
1061 case SSH2_MSG_USERAUTH_FAILURE:
1062 case SSH2_MSG_USERAUTH_SUCCESS:
1063 case SSH2_MSG_USERAUTH_BANNER:
1064 case SSH2_MSG_USERAUTH_PK_OK:
1065 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1066 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1067 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1068 case SSH2_MSG_GLOBAL_REQUEST:
1069 case SSH2_MSG_REQUEST_SUCCESS:
1070 case SSH2_MSG_REQUEST_FAILURE:
1071 case SSH2_MSG_CHANNEL_OPEN:
1072 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1073 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1074 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1075 case SSH2_MSG_CHANNEL_DATA:
1076 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1077 case SSH2_MSG_CHANNEL_EOF:
1078 case SSH2_MSG_CHANNEL_CLOSE:
1079 case SSH2_MSG_CHANNEL_REQUEST:
1080 case SSH2_MSG_CHANNEL_SUCCESS:
1081 case SSH2_MSG_CHANNEL_FAILURE:
1082 break;
1083
1084 /*
1085 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1086 */
1087 default:
1088 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
1089 ssh2_pkt_adduint32(st->incoming_sequence - 1);
1090 ssh2_pkt_send();
1091 break;
38c4a8da 1092 }
1093
e5574168 1094 crFinish(0);
1095}
1096
32874aea 1097static void ssh1_pktout_size(int len)
1098{
374330e2 1099 int pad, biglen;
1100
1101 len += 5; /* type and CRC */
32874aea 1102 pad = 8 - (len % 8);
374330e2 1103 biglen = len + pad;
1104
32874aea 1105 pktout.length = len - 5;
374330e2 1106 if (pktout.maxlen < biglen) {
1107 pktout.maxlen = biglen;
8f203108 1108#ifdef MSCRYPTOAPI
fb09bf1c 1109 /* Allocate enough buffer space for extra block
8f203108 1110 * for MS CryptEncrypt() */
32874aea 1111 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
1112 srealloc(pktout.data, biglen + 12));
8f203108 1113#else
32874aea 1114 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
1115 srealloc(pktout.data, biglen + 4));
8f203108 1116#endif
374330e2 1117 if (!pktout.data)
1118 fatalbox("Out of memory");
1119 }
32874aea 1120 pktout.body = pktout.data + 4 + pad + 1;
4ba9b64b 1121}
374330e2 1122
32874aea 1123static void s_wrpkt_start(int type, int len)
1124{
4ba9b64b 1125 ssh1_pktout_size(len);
374330e2 1126 pktout.type = type;
374330e2 1127}
1128
32874aea 1129static int s_wrpkt_prepare(void)
1130{
374330e2 1131 int pad, len, biglen, i;
1132 unsigned long crc;
1133
4ba9b64b 1134 pktout.body[-1] = pktout.type;
1135
00db133f 1136 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1137 pktout.body, pktout.length);
1138
4ba9b64b 1139 if (ssh1_compressing) {
1140 unsigned char *compblk;
1141 int complen;
32874aea 1142 zlib_compress_block(pktout.body - 1, pktout.length + 1,
4ba9b64b 1143 &compblk, &complen);
32874aea 1144 ssh1_pktout_size(complen - 1);
1145 memcpy(pktout.body - 1, compblk, complen);
dcbde236 1146 sfree(compblk);
4ba9b64b 1147 }
1148
374330e2 1149 len = pktout.length + 5; /* type and CRC */
32874aea 1150 pad = 8 - (len % 8);
374330e2 1151 biglen = len + pad;
1152
32874aea 1153 for (i = 0; i < pad; i++)
1154 pktout.data[i + 4] = random_byte();
1155 crc = crc32(pktout.data + 4, biglen - 4);
1156 PUT_32BIT(pktout.data + biglen, crc);
fb09bf1c 1157 PUT_32BIT(pktout.data, len);
374330e2 1158
1159 if (cipher)
32874aea 1160 cipher->encrypt(pktout.data + 4, biglen);
374330e2 1161
32874aea 1162 return biglen + 4;
39065bed 1163}
1164
32874aea 1165static void s_wrpkt(void)
1166{
5471d09a 1167 int len, backlog;
39065bed 1168 len = s_wrpkt_prepare();
5471d09a 1169 backlog = sk_write(s, pktout.data, len);
1170 if (backlog > SSH_MAX_BACKLOG)
1171 ssh_throttle_all(1, backlog);
39065bed 1172}
1173
32874aea 1174static void s_wrpkt_defer(void)
1175{
39065bed 1176 int len;
1177 len = s_wrpkt_prepare();
1178 if (deferred_len + len > deferred_size) {
32874aea 1179 deferred_size = deferred_len + len + 128;
1180 deferred_send_data = srealloc(deferred_send_data, deferred_size);
39065bed 1181 }
32874aea 1182 memcpy(deferred_send_data + deferred_len, pktout.data, len);
39065bed 1183 deferred_len += len;
374330e2 1184}
1185
fb09bf1c 1186/*
39065bed 1187 * Construct a packet with the specified contents.
fb09bf1c 1188 */
39065bed 1189static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1190{
fb09bf1c 1191 unsigned char *p, *argp, argchar;
1192 unsigned long argint;
1193 int pktlen, argtype, arglen;
7cca0d81 1194 Bignum bn;
fb09bf1c 1195
1196 pktlen = 0;
39065bed 1197 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1198 switch (argtype) {
1199 case PKT_INT:
39065bed 1200 (void) va_arg(ap1, int);
fb09bf1c 1201 pktlen += 4;
1202 break;
1203 case PKT_CHAR:
39065bed 1204 (void) va_arg(ap1, char);
fb09bf1c 1205 pktlen++;
1206 break;
1207 case PKT_DATA:
39065bed 1208 (void) va_arg(ap1, unsigned char *);
1209 arglen = va_arg(ap1, int);
fb09bf1c 1210 pktlen += arglen;
1211 break;
1212 case PKT_STR:
39065bed 1213 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1214 arglen = strlen(argp);
1215 pktlen += 4 + arglen;
1216 break;
7cca0d81 1217 case PKT_BIGNUM:
39065bed 1218 bn = va_arg(ap1, Bignum);
32874aea 1219 pktlen += ssh1_bignum_length(bn);
7cca0d81 1220 break;
fb09bf1c 1221 default:
1222 assert(0);
1223 }
1224 }
fb09bf1c 1225
1226 s_wrpkt_start(pkttype, pktlen);
1227 p = pktout.body;
1228
39065bed 1229 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1230 switch (argtype) {
1231 case PKT_INT:
39065bed 1232 argint = va_arg(ap2, int);
fb09bf1c 1233 PUT_32BIT(p, argint);
1234 p += 4;
1235 break;
1236 case PKT_CHAR:
39065bed 1237 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1238 *p = argchar;
1239 p++;
1240 break;
1241 case PKT_DATA:
39065bed 1242 argp = va_arg(ap2, unsigned char *);
1243 arglen = va_arg(ap2, int);
fb09bf1c 1244 memcpy(p, argp, arglen);
1245 p += arglen;
1246 break;
1247 case PKT_STR:
39065bed 1248 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1249 arglen = strlen(argp);
1250 PUT_32BIT(p, arglen);
1251 memcpy(p + 4, argp, arglen);
1252 p += 4 + arglen;
1253 break;
7cca0d81 1254 case PKT_BIGNUM:
39065bed 1255 bn = va_arg(ap2, Bignum);
32874aea 1256 p += ssh1_write_bignum(p, bn);
7cca0d81 1257 break;
fb09bf1c 1258 }
1259 }
39065bed 1260}
fb09bf1c 1261
32874aea 1262static void send_packet(int pkttype, ...)
1263{
39065bed 1264 va_list ap1, ap2;
1265 va_start(ap1, pkttype);
1266 va_start(ap2, pkttype);
1267 construct_packet(pkttype, ap1, ap2);
fb09bf1c 1268 s_wrpkt();
1269}
1270
32874aea 1271static void defer_packet(int pkttype, ...)
1272{
39065bed 1273 va_list ap1, ap2;
1274 va_start(ap1, pkttype);
1275 va_start(ap2, pkttype);
1276 construct_packet(pkttype, ap1, ap2);
1277 s_wrpkt_defer();
1278}
1279
32874aea 1280static int ssh_versioncmp(char *a, char *b)
1281{
9697bfd2 1282 char *ae, *be;
1283 unsigned long av, bv;
1284
43aa02a7 1285 av = strtoul(a, &ae, 10);
1286 bv = strtoul(b, &be, 10);
32874aea 1287 if (av != bv)
1288 return (av < bv ? -1 : +1);
1289 if (*ae == '.')
1290 ae++;
1291 if (*be == '.')
1292 be++;
43aa02a7 1293 av = strtoul(ae, &ae, 10);
1294 bv = strtoul(be, &be, 10);
32874aea 1295 if (av != bv)
1296 return (av < bv ? -1 : +1);
9697bfd2 1297 return 0;
1298}
1299
e5574168 1300
1301/*
a92dd380 1302 * Utility routines for putting an SSH-protocol `string' and
1303 * `uint32' into a SHA state.
e5574168 1304 */
1305#include <stdio.h>
32874aea 1306static void sha_string(SHA_State * s, void *str, int len)
1307{
e5574168 1308 unsigned char lenblk[4];
e5574168 1309 PUT_32BIT(lenblk, len);
e5574168 1310 SHA_Bytes(s, lenblk, 4);
e5574168 1311 SHA_Bytes(s, str, len);
1312}
1313
32874aea 1314static void sha_uint32(SHA_State * s, unsigned i)
1315{
a92dd380 1316 unsigned char intblk[4];
1317 PUT_32BIT(intblk, i);
1318 SHA_Bytes(s, intblk, 4);
1319}
1320
7cca0d81 1321/*
1322 * SSH2 packet construction functions.
1323 */
32874aea 1324static void ssh2_pkt_ensure(int length)
1325{
783415f8 1326 if (pktout.maxlen < length) {
32874aea 1327 pktout.maxlen = length + 256;
1328 pktout.data =
1329 (pktout.data ==
1330 NULL ? smalloc(pktout.maxlen +
1331 APIEXTRA) : srealloc(pktout.data,
1332 pktout.maxlen +
1333 APIEXTRA));
1334 if (!pktout.data)
1335 fatalbox("Out of memory");
7cca0d81 1336 }
783415f8 1337}
32874aea 1338static void ssh2_pkt_adddata(void *data, int len)
1339{
783415f8 1340 pktout.length += len;
1341 ssh2_pkt_ensure(pktout.length);
32874aea 1342 memcpy(pktout.data + pktout.length - len, data, len);
7cca0d81 1343}
32874aea 1344static void ssh2_pkt_addbyte(unsigned char byte)
1345{
7cca0d81 1346 ssh2_pkt_adddata(&byte, 1);
1347}
32874aea 1348static void ssh2_pkt_init(int pkt_type)
1349{
7cca0d81 1350 pktout.length = 5;
32874aea 1351 ssh2_pkt_addbyte((unsigned char) pkt_type);
7cca0d81 1352}
32874aea 1353static void ssh2_pkt_addbool(unsigned char value)
1354{
7cca0d81 1355 ssh2_pkt_adddata(&value, 1);
1356}
32874aea 1357static void ssh2_pkt_adduint32(unsigned long value)
1358{
7cca0d81 1359 unsigned char x[4];
1360 PUT_32BIT(x, value);
1361 ssh2_pkt_adddata(x, 4);
1362}
32874aea 1363static void ssh2_pkt_addstring_start(void)
1364{
7cca0d81 1365 ssh2_pkt_adduint32(0);
1366 pktout.savedpos = pktout.length;
1367}
32874aea 1368static void ssh2_pkt_addstring_str(char *data)
1369{
7cca0d81 1370 ssh2_pkt_adddata(data, strlen(data));
1371 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1372 pktout.length - pktout.savedpos);
7cca0d81 1373}
32874aea 1374static void ssh2_pkt_addstring_data(char *data, int len)
1375{
7cca0d81 1376 ssh2_pkt_adddata(data, len);
1377 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1378 pktout.length - pktout.savedpos);
7cca0d81 1379}
32874aea 1380static void ssh2_pkt_addstring(char *data)
1381{
7cca0d81 1382 ssh2_pkt_addstring_start();
1383 ssh2_pkt_addstring_str(data);
1384}
32874aea 1385static char *ssh2_mpint_fmt(Bignum b, int *len)
1386{
7cca0d81 1387 unsigned char *p;
32874aea 1388 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1389 p = smalloc(n + 1);
7cca0d81 1390 if (!p)
32874aea 1391 fatalbox("out of memory");
7cca0d81 1392 p[0] = 0;
3709bfe9 1393 for (i = 1; i <= n; i++)
32874aea 1394 p[i] = bignum_byte(b, n - i);
7cca0d81 1395 i = 0;
32874aea 1396 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1397 i++;
1398 memmove(p, p + i, n + 1 - i);
1399 *len = n + 1 - i;
7cca0d81 1400 return p;
1401}
32874aea 1402static void ssh2_pkt_addmp(Bignum b)
1403{
7cca0d81 1404 unsigned char *p;
1405 int len;
1406 p = ssh2_mpint_fmt(b, &len);
1407 ssh2_pkt_addstring_start();
1408 ssh2_pkt_addstring_data(p, len);
dcbde236 1409 sfree(p);
7cca0d81 1410}
b185170a 1411
1412/*
1413 * Construct an SSH2 final-form packet: compress it, encrypt it,
1414 * put the MAC on it. Final packet, ready to be sent, is stored in
1415 * pktout.data. Total length is returned.
1416 */
32874aea 1417static int ssh2_pkt_construct(void)
1418{
7cca0d81 1419 int cipherblk, maclen, padding, i;
1420 static unsigned long outgoing_sequence = 0;
1421
00db133f 1422 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1423 pktout.data + 6, pktout.length - 6);
1424
7cca0d81 1425 /*
4ba9b64b 1426 * Compress packet payload.
1427 */
4ba9b64b 1428 {
1429 unsigned char *newpayload;
1430 int newlen;
32874aea 1431 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
4ba9b64b 1432 &newpayload, &newlen)) {
1433 pktout.length = 5;
1434 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1435 sfree(newpayload);
4ba9b64b 1436 }
1437 }
1438
1439 /*
7cca0d81 1440 * Add padding. At least four bytes, and must also bring total
1441 * length (minus MAC) up to a multiple of the block size.
1442 */
32874aea 1443 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1444 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1445 padding = 4;
32874aea 1446 padding +=
1447 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1448 maclen = csmac ? csmac->len : 0;
1449 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1450 pktout.data[4] = padding;
1451 for (i = 0; i < padding; i++)
32874aea 1452 pktout.data[pktout.length + i] = random_byte();
7cca0d81 1453 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1454 if (csmac)
32874aea 1455 csmac->generate(pktout.data, pktout.length + padding,
1456 outgoing_sequence);
1457 outgoing_sequence++; /* whether or not we MACed */
7cca0d81 1458
7cca0d81 1459 if (cscipher)
32874aea 1460 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1461
b185170a 1462 /* Ready-to-send packet starts at pktout.data. We return length. */
1463 return pktout.length + padding + maclen;
1464}
1465
1466/*
1467 * Construct and send an SSH2 packet immediately.
1468 */
32874aea 1469static void ssh2_pkt_send(void)
1470{
5471d09a 1471 int len;
1472 int backlog;
1473 len = ssh2_pkt_construct();
1474 backlog = sk_write(s, pktout.data, len);
1475 if (backlog > SSH_MAX_BACKLOG)
1476 ssh_throttle_all(1, backlog);
b185170a 1477}
1478
1479/*
1480 * Construct an SSH2 packet and add it to a deferred data block.
1481 * Useful for sending multiple packets in a single sk_write() call,
1482 * to prevent a traffic-analysing listener from being able to work
1483 * out the length of any particular packet (such as the password
1484 * packet).
1485 *
1486 * Note that because SSH2 sequence-numbers its packets, this can
1487 * NOT be used as an m4-style `defer' allowing packets to be
1488 * constructed in one order and sent in another.
1489 */
32874aea 1490static void ssh2_pkt_defer(void)
1491{
b185170a 1492 int len = ssh2_pkt_construct();
1493 if (deferred_len + len > deferred_size) {
32874aea 1494 deferred_size = deferred_len + len + 128;
1495 deferred_send_data = srealloc(deferred_send_data, deferred_size);
b185170a 1496 }
32874aea 1497 memcpy(deferred_send_data + deferred_len, pktout.data, len);
b185170a 1498 deferred_len += len;
1499}
1500
1501/*
1502 * Send the whole deferred data block constructed by
39065bed 1503 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1504 */
32874aea 1505static void ssh_pkt_defersend(void)
1506{
5471d09a 1507 int backlog;
1508 backlog = sk_write(s, deferred_send_data, deferred_len);
b185170a 1509 deferred_len = deferred_size = 0;
1510 sfree(deferred_send_data);
1511 deferred_send_data = NULL;
5471d09a 1512 if (backlog > SSH_MAX_BACKLOG)
1513 ssh_throttle_all(1, backlog);
7cca0d81 1514}
1515
1516#if 0
32874aea 1517void bndebug(char *string, Bignum b)
1518{
7cca0d81 1519 unsigned char *p;
1520 int i, len;
1521 p = ssh2_mpint_fmt(b, &len);
1522 debug(("%s", string));
1523 for (i = 0; i < len; i++)
32874aea 1524 debug((" %02x", p[i]));
765c4200 1525 debug(("\n"));
dcbde236 1526 sfree(p);
7cca0d81 1527}
1528#endif
1529
32874aea 1530static void sha_mpint(SHA_State * s, Bignum b)
1531{
7cca0d81 1532 unsigned char *p;
1533 int len;
1534 p = ssh2_mpint_fmt(b, &len);
1535 sha_string(s, p, len);
dcbde236 1536 sfree(p);
7cca0d81 1537}
1538
1539/*
1540 * SSH2 packet decode functions.
1541 */
32874aea 1542static unsigned long ssh2_pkt_getuint32(void)
1543{
7cca0d81 1544 unsigned long value;
1545 if (pktin.length - pktin.savedpos < 4)
32874aea 1546 return 0; /* arrgh, no way to decline (FIXME?) */
1547 value = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1548 pktin.savedpos += 4;
1549 return value;
1550}
32874aea 1551static int ssh2_pkt_getbool(void)
1552{
65a22376 1553 unsigned long value;
1554 if (pktin.length - pktin.savedpos < 1)
32874aea 1555 return 0; /* arrgh, no way to decline (FIXME?) */
65a22376 1556 value = pktin.data[pktin.savedpos] != 0;
1557 pktin.savedpos++;
1558 return value;
1559}
32874aea 1560static void ssh2_pkt_getstring(char **p, int *length)
1561{
7cca0d81 1562 *p = NULL;
45068b27 1563 *length = 0;
7cca0d81 1564 if (pktin.length - pktin.savedpos < 4)
32874aea 1565 return;
1566 *length = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1567 pktin.savedpos += 4;
1568 if (pktin.length - pktin.savedpos < *length)
32874aea 1569 return;
1570 *p = pktin.data + pktin.savedpos;
7cca0d81 1571 pktin.savedpos += *length;
1572}
32874aea 1573static Bignum ssh2_pkt_getmp(void)
1574{
7cca0d81 1575 char *p;
3709bfe9 1576 int length;
7cca0d81 1577 Bignum b;
1578
1579 ssh2_pkt_getstring(&p, &length);
1580 if (!p)
32874aea 1581 return NULL;
8d5de777 1582 if (p[0] & 0x80) {
32874aea 1583 bombout(("internal error: Can't handle negative mpints"));
1584 return NULL;
8d5de777 1585 }
3709bfe9 1586 b = bignum_from_bytes(p, length);
7cca0d81 1587 return b;
1588}
1589
7d503c31 1590/*
1dd353b5 1591 * Helper function to add an SSH2 signature blob to a packet.
1592 * Expects to be shown the public key blob as well as the signature
1593 * blob. Normally works just like ssh2_pkt_addstring, but will
1594 * fiddle with the signature packet if necessary for
1595 * BUG_SSH2_RSA_PADDING.
1596 */
1597static void ssh2_add_sigblob(void *pkblob_v, int pkblob_len,
1598 void *sigblob_v, int sigblob_len)
1599{
1600 unsigned char *pkblob = (unsigned char *)pkblob_v;
1601 unsigned char *sigblob = (unsigned char *)sigblob_v;
1602
1603 /* dmemdump(pkblob, pkblob_len); */
1604 /* dmemdump(sigblob, sigblob_len); */
1605
1606 /*
1607 * See if this is in fact an ssh-rsa signature and a buggy
1608 * server; otherwise we can just do this the easy way.
1609 */
1610 if ((ssh_remote_bugs & BUG_SSH2_RSA_PADDING) &&
1611 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1612 int pos, len, siglen;
1613
1614 /*
1615 * Find the byte length of the modulus.
1616 */
1617
1618 pos = 4+7; /* skip over "ssh-rsa" */
1619 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1620 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1621 pos += 4; /* find modulus itself */
1622 while (len > 0 && pkblob[pos] == 0)
1623 len--, pos++;
1624 /* debug(("modulus length is %d\n", len)); */
1625
1626 /*
1627 * Now find the signature integer.
1628 */
1629 pos = 4+7; /* skip over "ssh-rsa" */
1630 siglen = GET_32BIT(sigblob+pos);
1631 /* debug(("signature length is %d\n", siglen)); */
1632
1633 if (len != siglen) {
1634 unsigned char newlen[4];
1635 ssh2_pkt_addstring_start();
1636 ssh2_pkt_addstring_data(sigblob, pos);
1637 /* dmemdump(sigblob, pos); */
1638 pos += 4; /* point to start of actual sig */
1639 PUT_32BIT(newlen, len);
1640 ssh2_pkt_addstring_data(newlen, 4);
1641 /* dmemdump(newlen, 4); */
1642 newlen[0] = 0;
1643 while (len-- > siglen) {
1644 ssh2_pkt_addstring_data(newlen, 1);
1645 /* dmemdump(newlen, 1); */
1646 }
1647 ssh2_pkt_addstring_data(sigblob+pos, siglen);
1648 /* dmemdump(sigblob+pos, siglen); */
1649 return;
1650 }
1651
1652 /* Otherwise fall through and do it the easy way. */
1653 }
1654
1655 ssh2_pkt_addstring_start();
1656 ssh2_pkt_addstring_data(sigblob, sigblob_len);
1657}
1658
1659/*
7d503c31 1660 * Examine the remote side's version string and compare it against
1661 * a list of known buggy implementations.
1662 */
32874aea 1663static void ssh_detect_bugs(char *vstring)
1664{
1665 char *imp; /* pointer to implementation part */
7d503c31 1666 imp = vstring;
1667 imp += strcspn(imp, "-");
bd358db1 1668 if (*imp) imp++;
7d503c31 1669 imp += strcspn(imp, "-");
bd358db1 1670 if (*imp) imp++;
7d503c31 1671
1672 ssh_remote_bugs = 0;
1673
2c9c6388 1674 if (cfg.sshbug_ignore1 == BUG_ON ||
1675 (cfg.sshbug_ignore1 == BUG_AUTO &&
1676 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1677 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1678 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
32874aea 1679 /*
1680 * These versions don't support SSH1_MSG_IGNORE, so we have
1681 * to use a different defence against password length
1682 * sniffing.
1683 */
1684 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1685 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1686 }
1687
2c9c6388 1688 if (cfg.sshbug_plainpw1 == BUG_ON ||
1689 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1690 (!strcmp(imp, "Cisco-1.25")))) {
bd358db1 1691 /*
1692 * These versions need a plain password sent; they can't
1693 * handle having a null and a random length of data after
1694 * the password.
1695 */
1696 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1697 logevent("We believe remote version needs a plain SSH1 password");
1698 }
1699
2c9c6388 1700 if (cfg.sshbug_rsa1 == BUG_ON ||
1701 (cfg.sshbug_rsa1 == BUG_AUTO &&
1702 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1703 /*
1704 * These versions apparently have no clue whatever about
1705 * RSA authentication and will panic and die if they see
1706 * an AUTH_RSA message.
1707 */
1708 ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
1709 logevent("We believe remote version can't handle RSA authentication");
1710 }
1711
2c9c6388 1712 if (cfg.sshbug_hmac2 == BUG_ON ||
1713 (cfg.sshbug_hmac2 == BUG_AUTO &&
1714 (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1715 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1716 !strncmp(imp, "2.1 ", 4)))) {
32874aea 1717 /*
1718 * These versions have the HMAC bug.
1719 */
1720 ssh_remote_bugs |= BUG_SSH2_HMAC;
1721 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1722 }
1dd353b5 1723
2c9c6388 1724 if (cfg.sshbug_derivekey2 == BUG_ON ||
1725 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1726 (!strncmp(imp, "2.0.", 4)))) {
088bde77 1727 /*
1728 * These versions have the key-derivation bug (failing to
1729 * include the literal shared secret in the hashes that
1730 * generate the keys).
1731 */
1732 ssh_remote_bugs |= BUG_SSH2_DERIVEKEY;
1733 logevent("We believe remote version has SSH2 key-derivation bug");
1734 }
1735
2c9c6388 1736 if (cfg.sshbug_rsapad2 == BUG_ON ||
1737 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1738 ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1739 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')))){
1dd353b5 1740 /*
1741 * These versions have the SSH2 RSA padding bug.
1742 */
1743 ssh_remote_bugs |= BUG_SSH2_RSA_PADDING;
1744 logevent("We believe remote version has SSH2 RSA padding bug");
1745 }
8e975795 1746
1747 if (cfg.sshbug_dhgex2 == BUG_ON) {
1748 /*
1749 * These versions have the SSH2 DH GEX bug.
1750 */
1751 ssh_remote_bugs |= BUG_SSH2_DH_GEX;
1752 logevent("We believe remote version has SSH2 DH group exchange bug");
1753 }
7d503c31 1754}
1755
32874aea 1756static int do_ssh_init(unsigned char c)
1757{
2d466ffd 1758 static int vslen;
8df7a775 1759 static char version[10];
50526e47 1760 static char *vstring;
1761 static int vstrsize;
1762 static char *vlog;
8df7a775 1763 static int i;
38d228a2 1764 static int proto1, proto2;
374330e2 1765
8df7a775 1766 crBegin;
1767
1768 /* Search for the string "SSH-" in the input. */
374330e2 1769 i = 0;
8df7a775 1770 while (1) {
1771 static const int transS[] = { 1, 2, 2, 1 };
1772 static const int transH[] = { 0, 0, 3, 0 };
1773 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1774 if (c == 'S')
1775 i = transS[i];
1776 else if (c == 'H')
1777 i = transH[i];
1778 else if (c == '-')
1779 i = transminus[i];
1780 else
1781 i = 0;
8df7a775 1782 if (i < 0)
1783 break;
1784 crReturn(1); /* get another character */
374330e2 1785 }
8df7a775 1786
50526e47 1787 vstrsize = 16;
bd358db1 1788 vstring = smalloc(vstrsize);
c5e9c988 1789 strcpy(vstring, "SSH-");
50526e47 1790 vslen = 4;
374330e2 1791 i = 0;
1792 while (1) {
8df7a775 1793 crReturn(1); /* get another char */
32874aea 1794 if (vslen >= vstrsize - 1) {
1795 vstrsize += 16;
1796 vstring = srealloc(vstring, vstrsize);
1797 }
1798 vstring[vslen++] = c;
374330e2 1799 if (i >= 0) {
1800 if (c == '-') {
1801 version[i] = '\0';
1802 i = -1;
32874aea 1803 } else if (i < sizeof(version) - 1)
374330e2 1804 version[i++] = c;
32874aea 1805 } else if (c == '\n')
374330e2 1806 break;
1807 }
1808
db7d555c 1809 ssh_agentfwd_enabled = FALSE;
960e736a 1810 rdpkt2_state.incoming_sequence = 0;
1811
50526e47 1812 vstring[vslen] = 0;
9275ca8a 1813 vlog = smalloc(20 + vslen);
bd358db1 1814 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
c5e9c988 1815 sprintf(vlog, "Server version: %s", vstring);
c5e9c988 1816 logevent(vlog);
bd358db1 1817 ssh_detect_bugs(vstring);
9275ca8a 1818 sfree(vlog);
c5e9c988 1819
adf799dd 1820 /*
38d228a2 1821 * Decide which SSH protocol version to support.
adf799dd 1822 */
38d228a2 1823
1824 /* Anything strictly below "2.0" means protocol 1 is supported. */
1825 proto1 = ssh_versioncmp(version, "2.0") < 0;
1826 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
daa72738 1827 proto2 = ssh_versioncmp(version, "1.99") >= 0;
38d228a2 1828
1829 if (cfg.sshprot == 0 && !proto1) {
1830 bombout(("SSH protocol version 1 required by user but not provided by server"));
1831 crReturn(0);
1832 }
1833 if (cfg.sshprot == 3 && !proto2) {
1834 bombout(("SSH protocol version 2 required by user but not provided by server"));
1835 crReturn(0);
1836 }
1837
daa72738 1838 if (proto2 && (cfg.sshprot >= 2 || !proto1)) {
32874aea 1839 /*
38d228a2 1840 * Use v2 protocol.
32874aea 1841 */
1842 char verstring[80], vlog[100];
1843 sprintf(verstring, "SSH-2.0-%s", sshver);
1844 SHA_Init(&exhashbase);
1845 /*
1846 * Hash our version string and their version string.
1847 */
1848 sha_string(&exhashbase, verstring, strlen(verstring));
1849 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1850 sprintf(vlog, "We claim version: %s", verstring);
1851 logevent(vlog);
1852 strcat(verstring, "\n");
1853 logevent("Using SSH protocol version 2");
1854 sk_write(s, verstring, strlen(verstring));
1855 ssh_protocol = ssh2_protocol;
1856 ssh_version = 2;
1857 s_rdpkt = ssh2_rdpkt;
e5574168 1858 } else {
32874aea 1859 /*
38d228a2 1860 * Use v1 protocol.
32874aea 1861 */
1862 char verstring[80], vlog[100];
1863 sprintf(verstring, "SSH-%s-%s",
1864 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1865 sshver);
1866 sprintf(vlog, "We claim version: %s", verstring);
1867 logevent(vlog);
1868 strcat(verstring, "\n");
759712a6 1869
32874aea 1870 logevent("Using SSH protocol version 1");
1871 sk_write(s, verstring, strlen(verstring));
1872 ssh_protocol = ssh1_protocol;
1873 ssh_version = 1;
1874 s_rdpkt = ssh1_rdpkt;
e5574168 1875 }
3687d221 1876 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1877
50526e47 1878 sfree(vstring);
50526e47 1879
8df7a775 1880 crFinish(0);
1881}
1882
1883static void ssh_gotdata(unsigned char *data, int datalen)
1884{
1885 crBegin;
1886
1887 /*
1888 * To begin with, feed the characters one by one to the
1889 * protocol initialisation / selection function do_ssh_init().
1890 * When that returns 0, we're done with the initial greeting
1891 * exchange and can move on to packet discipline.
1892 */
1893 while (1) {
1894 int ret;
1895 if (datalen == 0)
1896 crReturnV; /* more data please */
1897 ret = do_ssh_init(*data);
32874aea 1898 data++;
1899 datalen--;
8df7a775 1900 if (ret == 0)
1901 break;
1902 }
1903
1904 /*
1905 * We emerge from that loop when the initial negotiation is
1906 * over and we have selected an s_rdpkt function. Now pass
1907 * everything to s_rdpkt, and then pass the resulting packets
1908 * to the proper protocol handler.
1909 */
1910 if (datalen == 0)
1911 crReturnV;
1912 while (1) {
1913 while (datalen > 0) {
32874aea 1914 if (s_rdpkt(&data, &datalen) == 0) {
e14d0f19 1915 if (ssh_state == SSH_STATE_CLOSED) {
1916 return;
1917 }
8df7a775 1918 ssh_protocol(NULL, 0, 1);
1919 if (ssh_state == SSH_STATE_CLOSED) {
1920 return;
1921 }
1922 }
1923 }
1924 crReturnV;
1925 }
1926 crFinishV;
1927}
1928
32874aea 1929static int ssh_closing(Plug plug, char *error_msg, int error_code,
1930 int calling_back)
1931{
7e78000d 1932 ssh_state = SSH_STATE_CLOSED;
f3ab576e 1933 if (s) {
1934 sk_close(s);
1935 s = NULL;
1936 }
7e78000d 1937 if (error_msg) {
32874aea 1938 /* A socket error has occurred. */
247308b5 1939 logevent(error_msg);
32874aea 1940 connection_fatal(error_msg);
7e78000d 1941 } else {
1942 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1943 }
7e78000d 1944 return 0;
1945}
1946
32874aea 1947static int ssh_receive(Plug plug, int urgent, char *data, int len)
1948{
1949 ssh_gotdata(data, len);
3257deae 1950 if (ssh_state == SSH_STATE_CLOSED) {
32874aea 1951 if (s) {
1952 sk_close(s);
1953 s = NULL;
1954 }
1955 return 0;
3257deae 1956 }
fef97f43 1957 return 1;
374330e2 1958}
1959
5471d09a 1960static void ssh_sent(Plug plug, int bufsize)
1961{
1962 /*
1963 * If the send backlog on the SSH socket itself clears, we
1964 * should unthrottle the whole world if it was throttled.
1965 */
1966 if (bufsize < SSH_MAX_BACKLOG)
1967 ssh_throttle_all(0, bufsize);
1968}
1969
fb09bf1c 1970/*
8df7a775 1971 * Connect to specified host and port.
1972 * Returns an error message, or NULL on success.
6e1ebb76 1973 * Also places the canonical host name into `realhost'. It must be
1974 * freed by the caller.
8df7a775 1975 */
2184a5d9 1976static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
8df7a775 1977{
7e78000d 1978 static struct plug_function_table fn_table = {
1979 ssh_closing,
5471d09a 1980 ssh_receive,
1981 ssh_sent,
1982 NULL
7e78000d 1983 }, *fn_table_ptr = &fn_table;
1984
8df7a775 1985 SockAddr addr;
1986 char *err;
1987#ifdef FWHACK
1988 char *FWhost;
1989 int FWport;
1990#endif
1991
32874aea 1992 savedhost = smalloc(1 + strlen(host));
8df7a775 1993 if (!savedhost)
1994 fatalbox("Out of memory");
1995 strcpy(savedhost, host);
1996
1997 if (port < 0)
1998 port = 22; /* default ssh port */
1999 savedport = port;
2000
2001#ifdef FWHACK
2002 FWhost = host;
2003 FWport = port;
2004 host = FWSTR;
2005 port = 23;
2006#endif
2007
2008 /*
2009 * Try to find host.
2010 */
3ad9d396 2011 {
2012 char buf[200];
2013 sprintf(buf, "Looking up host \"%.170s\"", host);
2014 logevent(buf);
2015 }
8df7a775 2016 addr = sk_namelookup(host, realhost);
32874aea 2017 if ((err = sk_addr_error(addr)))
8df7a775 2018 return err;
2019
2020#ifdef FWHACK
6e1ebb76 2021 *realhost = strdup(FWhost);
8df7a775 2022#endif
2023
2024 /*
2025 * Open socket.
2026 */
3ad9d396 2027 {
2028 char buf[200], addrbuf[100];
2029 sk_getaddr(addr, addrbuf, 100);
2030 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
2031 logevent(buf);
2032 }
8eebd221 2033 s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
67c4ba2e 2034 if ((err = sk_socket_error(s))) {
2035 s = NULL;
8df7a775 2036 return err;
67c4ba2e 2037 }
8df7a775 2038
2039#ifdef FWHACK
2040 sk_write(s, "connect ", 8);
2041 sk_write(s, FWhost, strlen(FWhost));
2042 {
2043 char buf[20];
2044 sprintf(buf, " %d\n", FWport);
2045 sk_write(s, buf, strlen(buf));
2046 }
2047#endif
2048
2049 return NULL;
2050}
2051
2052/*
5471d09a 2053 * Throttle or unthrottle the SSH connection.
2054 */
2055static void ssh1_throttle(int adjust)
2056{
2057 int old_count = ssh1_throttle_count;
2058 ssh1_throttle_count += adjust;
2059 assert(ssh1_throttle_count >= 0);
2060 if (ssh1_throttle_count && !old_count) {
2061 sk_set_frozen(s, 1);
2062 } else if (!ssh1_throttle_count && old_count) {
2063 sk_set_frozen(s, 0);
2064 }
2065}
2066
2067/*
2068 * Throttle or unthrottle _all_ local data streams (for when sends
2069 * on the SSH connection itself back up).
2070 */
2071static void ssh_throttle_all(int enable, int bufsize)
2072{
2073 int i;
2074 struct ssh_channel *c;
2075
2076 if (enable == ssh_throttled_all)
2077 return;
2078 ssh_throttled_all = enable;
2079 ssh_overall_bufsize = bufsize;
2080 if (!ssh_channels)
2081 return;
2082 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
2083 switch (c->type) {
2084 case CHAN_MAINSESSION:
2085 /*
2086 * This is treated separately, outside the switch.
2087 */
2088 break;
2089 case CHAN_X11:
2090 x11_override_throttle(c->u.x11.s, enable);
2091 break;
2092 case CHAN_AGENT:
2093 /* Agent channels require no buffer management. */
2094 break;
2095 case CHAN_SOCKDATA:
2096 pfd_override_throttle(c->u.x11.s, enable);
2097 break;
2098 }
2099 }
2100}
2101
2102/*
0405e71f 2103 * Username and password input, abstracted off into reusable
2104 * routines (hopefully even reusable between SSH1 and SSH2!).
2105 */
2106static char *ssh_userpass_input_buffer;
2107static int ssh_userpass_input_buflen;
2108static int ssh_userpass_input_bufpos;
2109static int ssh_userpass_input_echo;
2110
2111/* Set up a username or password input loop on a given buffer. */
2112void setup_userpass_input(char *buffer, int buflen, int echo)
2113{
2114 ssh_userpass_input_buffer = buffer;
2115 ssh_userpass_input_buflen = buflen;
2116 ssh_userpass_input_bufpos = 0;
2117 ssh_userpass_input_echo = echo;
2118}
2119
2120/*
2121 * Process some terminal data in the course of username/password
2122 * input. Returns >0 for success (line of input returned in
2123 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2124 * for inconclusive (keep waiting for more input please).
2125 */
2126int process_userpass_input(unsigned char *in, int inlen)
2127{
2128 char c;
2129
2130 while (inlen--) {
2131 switch (c = *in++) {
2132 case 10:
2133 case 13:
2134 ssh_userpass_input_buffer[ssh_userpass_input_bufpos] = 0;
2135 ssh_userpass_input_buffer[ssh_userpass_input_buflen-1] = 0;
2136 return +1;
2137 break;
2138 case 8:
2139 case 127:
2140 if (ssh_userpass_input_bufpos > 0) {
2141 if (ssh_userpass_input_echo)
2142 c_write_str("\b \b");
2143 ssh_userpass_input_bufpos--;
2144 }
2145 break;
2146 case 21:
2147 case 27:
2148 while (ssh_userpass_input_bufpos > 0) {
2149 if (ssh_userpass_input_echo)
2150 c_write_str("\b \b");
2151 ssh_userpass_input_bufpos--;
2152 }
2153 break;
2154 case 3:
2155 case 4:
2156 return -1;
2157 break;
2158 default:
2159 if (((c >= ' ' && c <= '~') ||
2160 ((unsigned char) c >= 160))
2161 && ssh_userpass_input_bufpos < ssh_userpass_input_buflen-1) {
2162 ssh_userpass_input_buffer[ssh_userpass_input_bufpos++] = c;
2163 if (ssh_userpass_input_echo)
2164 c_write(&c, 1);
2165 }
2166 break;
2167 }
2168 }
2169 return 0;
2170}
2171
2172/*
fb09bf1c 2173 * Handle the key exchange and user authentication phases.
2174 */
e5574168 2175static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 2176{
2d466ffd 2177 int i, j;
2178 static int len;
2179 static unsigned char *rsabuf, *keystr1, *keystr2;
374330e2 2180 unsigned char cookie[8];
2181 struct RSAKey servkey, hostkey;
2182 struct MD5Context md5c;
ccbfb941 2183 static unsigned long supported_ciphers_mask, supported_auths_mask;
67b59fbb 2184 static int tried_publickey, tried_agent;
614a20a0 2185 static int tis_auth_refused, ccard_auth_refused;
7cca0d81 2186 static unsigned char session_id[16];
2d466ffd 2187 static int cipher_type;
b585ec46 2188 static char username[100];
396778f1 2189 static void *publickey_blob;
2190 int publickey_bloblen;
374330e2 2191
374330e2 2192 crBegin;
2193
32874aea 2194 if (!ispkt)
2195 crWaitUntil(ispkt);
374330e2 2196
8d5de777 2197 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2198 bombout(("Public key packet not received"));
32874aea 2199 crReturn(0);
8d5de777 2200 }
374330e2 2201
c5e9c988 2202 logevent("Received public keys");
374330e2 2203
c5e9c988 2204 memcpy(cookie, pktin.body, 8);
374330e2 2205
32874aea 2206 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
2207 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
374330e2 2208
c5e9c988 2209 /*
1c2a93c4 2210 * Log the host key fingerprint.
c5e9c988 2211 */
c5e9c988 2212 {
2213 char logmsg[80];
1c2a93c4 2214 logevent("Host key fingerprint is:");
c5e9c988 2215 strcpy(logmsg, " ");
32874aea 2216 hostkey.comment = NULL;
2217 rsa_fingerprint(logmsg + strlen(logmsg),
2218 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2219 logevent(logmsg);
2220 }
2221
32874aea 2222 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2223 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2224 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
bea1ef5f 2225
32874aea 2226 ssh1_local_protoflags =
2227 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
b96dc54c 2228 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2229
c5e9c988 2230 MD5Init(&md5c);
374330e2 2231 MD5Update(&md5c, keystr2, hostkey.bytes);
2232 MD5Update(&md5c, keystr1, servkey.bytes);
2233 MD5Update(&md5c, pktin.body, 8);
374330e2 2234 MD5Final(session_id, &md5c);
2235
32874aea 2236 for (i = 0; i < 32; i++)
374330e2 2237 session_key[i] = random_byte();
2238
2239 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2240
dcbde236 2241 rsabuf = smalloc(len);
374330e2 2242 if (!rsabuf)
2243 fatalbox("Out of memory");
2244
89ee5268 2245 /*
2246 * Verify the host key.
2247 */
2248 {
32874aea 2249 /*
2250 * First format the key into a string.
2251 */
2252 int len = rsastr_len(&hostkey);
2253 char fingerprint[100];
2254 char *keystr = smalloc(len);
2255 if (!keystr)
2256 fatalbox("Out of memory");
2257 rsastr_fmt(keystr, &hostkey);
2258 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2259 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2260 fingerprint);
2261 sfree(keystr);
2262 }
2263
2264 for (i = 0; i < 32; i++) {
374330e2 2265 rsabuf[i] = session_key[i];
2266 if (i < 16)
2267 rsabuf[i] ^= session_id[i];
2268 }
2269
2270 if (hostkey.bytes > servkey.bytes) {
2271 rsaencrypt(rsabuf, 32, &servkey);
2272 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2273 } else {
2274 rsaencrypt(rsabuf, 32, &hostkey);
2275 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2276 }
2277
c5e9c988 2278 logevent("Encrypted session key");
2279
ca20bfcf 2280 {
2281 int cipher_chosen = 0, warn = 0;
2282 char *cipher_string = NULL;
2283 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2284 int next_cipher = cfg.ssh_cipherlist[i];
2285 if (next_cipher == CIPHER_WARN) {
2286 /* If/when we choose a cipher, warn about it */
2287 warn = 1;
2288 } else if (next_cipher == CIPHER_AES) {
2289 /* XXX Probably don't need to mention this. */
2290 logevent("AES not supported in SSH1, skipping");
2291 } else {
2292 switch (next_cipher) {
2293 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2294 cipher_string = "3DES"; break;
2295 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2296 cipher_string = "Blowfish"; break;
2297 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2298 cipher_string = "single-DES"; break;
2299 }
2300 if (supported_ciphers_mask & (1 << cipher_type))
2301 cipher_chosen = 1;
2302 }
2303 }
2304 if (!cipher_chosen) {
2305 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2306 bombout(("Server violates SSH 1 protocol by not "
2307 "supporting 3DES encryption"));
2308 else
2309 /* shouldn't happen */
2310 bombout(("No supported ciphers found"));
a99a05c0 2311 crReturn(0);
2312 }
ca20bfcf 2313
2314 /* Warn about chosen cipher if necessary. */
2315 if (warn)
2316 askcipher(cipher_string, 0);
bea1ef5f 2317 }
ca20bfcf 2318
c5e9c988 2319 switch (cipher_type) {
32874aea 2320 case SSH_CIPHER_3DES:
2321 logevent("Using 3DES encryption");
2322 break;
2323 case SSH_CIPHER_DES:
2324 logevent("Using single-DES encryption");
2325 break;
2326 case SSH_CIPHER_BLOWFISH:
2327 logevent("Using Blowfish encryption");
2328 break;
c5e9c988 2329 }
bea1ef5f 2330
e5574168 2331 send_packet(SSH1_CMSG_SESSION_KEY,
32874aea 2332 PKT_CHAR, cipher_type,
2333 PKT_DATA, cookie, 8,
2334 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2335 PKT_DATA, rsabuf, len,
2336 PKT_INT, ssh1_local_protoflags, PKT_END);
fb09bf1c 2337
c5e9c988 2338 logevent("Trying to enable encryption...");
374330e2 2339
dcbde236 2340 sfree(rsabuf);
374330e2 2341
5e8358ad 2342 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
32874aea 2343 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
374330e2 2344 cipher->sesskey(session_key);
2345
fb09bf1c 2346 crWaitUntil(ispkt);
374330e2 2347
8d5de777 2348 if (pktin.type != SSH1_SMSG_SUCCESS) {
2349 bombout(("Encryption not successfully enabled"));
32874aea 2350 crReturn(0);
8d5de777 2351 }
374330e2 2352
c5e9c988 2353 logevent("Successfully started encryption");
2354
374330e2 2355 fflush(stdout);
2356 {
67779be7 2357 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 2358 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2359 if (!ssh_get_line("login as: ",
2360 username, sizeof(username), FALSE)) {
2361 /*
2362 * get_line failed to get a username.
2363 * Terminate.
2364 */
2365 logevent("No username provided. Abandoning session.");
2366 ssh_state = SSH_STATE_CLOSED;
2367 crReturn(1);
2368 }
2369 } else {
0405e71f 2370 static int ret;
32874aea 2371 c_write_str("login as: ");
2372 ssh_send_ok = 1;
0405e71f 2373
2374 setup_userpass_input(username, sizeof(username), 1);
2375 do {
32874aea 2376 crWaitUntil(!ispkt);
0405e71f 2377 ret = process_userpass_input(in, inlen);
2378 } while (ret == 0);
2379 if (ret < 0)
2380 cleanup_exit(0);
32874aea 2381 c_write_str("\r\n");
32874aea 2382 }
2383 } else {
277fc55e 2384 strncpy(username, cfg.username, sizeof(username));
2385 username[sizeof(username)-1] = '\0';
374330e2 2386 }
fb09bf1c 2387
e5574168 2388 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 2389 {
32874aea 2390 char userlog[22 + sizeof(username)];
c5e9c988 2391 sprintf(userlog, "Sent username \"%s\"", username);
2392 logevent(userlog);
32874aea 2393 if (flags & FLAG_INTERACTIVE &&
2394 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2395 strcat(userlog, "\r\n");
32874aea 2396 c_write_str(userlog);
3c8e959b 2397 }
c5e9c988 2398 }
374330e2 2399 }
2400
fb09bf1c 2401 crWaitUntil(ispkt);
374330e2 2402
0df73905 2403 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2404 /* We must not attempt PK auth. Pretend we've already tried it. */
2405 tried_publickey = tried_agent = 1;
2406 } else {
2407 tried_publickey = tried_agent = 0;
2408 }
614a20a0 2409 tis_auth_refused = ccard_auth_refused = 0;
396778f1 2410 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2411 if (*cfg.keyfile) {
2412 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2413 publickey_blob = NULL;
2414 } else
2415 publickey_blob = NULL;
7cca0d81 2416
e5574168 2417 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 2418 static char password[100];
a52f067e 2419 static char prompt[200];
374330e2 2420 static int pos;
2421 static char c;
32874aea 2422 static int pwpkt_type;
32874aea 2423 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2424
67b59fbb 2425 if (agent_exists() && !tried_agent) {
32874aea 2426 /*
2427 * Attempt RSA authentication using Pageant.
2428 */
2429 static unsigned char request[5], *response, *p;
2430 static int responselen;
2431 static int i, nkeys;
2432 static int authed = FALSE;
2433 void *r;
2434
67b59fbb 2435 tried_agent = 1;
32874aea 2436 logevent("Pageant is running. Requesting keys.");
2437
2438 /* Request the keys held by the agent. */
2439 PUT_32BIT(request, 1);
2440 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2441 agent_query(request, 5, &r, &responselen);
2442 response = (unsigned char *) r;
2443 if (response && responselen >= 5 &&
2444 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2445 p = response + 5;
2446 nkeys = GET_32BIT(p);
2447 p += 4;
2448 {
2449 char buf[64];
2450 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2451 logevent(buf);
2452 }
2453 for (i = 0; i < nkeys; i++) {
2454 static struct RSAKey key;
2455 static Bignum challenge;
2456 static char *commentp;
2457 static int commentlen;
2458
2459 {
2460 char buf[64];
2461 sprintf(buf, "Trying Pageant key #%d", i);
2462 logevent(buf);
2463 }
396778f1 2464 if (publickey_blob &&
2465 !memcmp(p, publickey_blob, publickey_bloblen)) {
2466 logevent("This key matches configured key file");
2467 tried_publickey = 1;
2468 }
32874aea 2469 p += 4;
2470 p += ssh1_read_bignum(p, &key.exponent);
2471 p += ssh1_read_bignum(p, &key.modulus);
2472 commentlen = GET_32BIT(p);
2473 p += 4;
2474 commentp = p;
2475 p += commentlen;
2476 send_packet(SSH1_CMSG_AUTH_RSA,
2477 PKT_BIGNUM, key.modulus, PKT_END);
2478 crWaitUntil(ispkt);
2479 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2480 logevent("Key refused");
2481 continue;
2482 }
2483 logevent("Received RSA challenge");
2484 ssh1_read_bignum(pktin.body, &challenge);
2485 {
2486 char *agentreq, *q, *ret;
2d466ffd 2487 void *vret;
32874aea 2488 int len, retlen;
2489 len = 1 + 4; /* message type, bit count */
2490 len += ssh1_bignum_length(key.exponent);
2491 len += ssh1_bignum_length(key.modulus);
2492 len += ssh1_bignum_length(challenge);
2493 len += 16; /* session id */
2494 len += 4; /* response format */
2495 agentreq = smalloc(4 + len);
2496 PUT_32BIT(agentreq, len);
2497 q = agentreq + 4;
2498 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2499 PUT_32BIT(q, bignum_bitcount(key.modulus));
2500 q += 4;
2501 q += ssh1_write_bignum(q, key.exponent);
2502 q += ssh1_write_bignum(q, key.modulus);
2503 q += ssh1_write_bignum(q, challenge);
2504 memcpy(q, session_id, 16);
2505 q += 16;
2506 PUT_32BIT(q, 1); /* response format */
2d466ffd 2507 agent_query(agentreq, len + 4, &vret, &retlen);
2508 ret = vret;
32874aea 2509 sfree(agentreq);
2510 if (ret) {
2511 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2512 logevent("Sending Pageant's response");
2513 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2514 PKT_DATA, ret + 5, 16,
2515 PKT_END);
2516 sfree(ret);
2517 crWaitUntil(ispkt);
2518 if (pktin.type == SSH1_SMSG_SUCCESS) {
2519 logevent
2520 ("Pageant's response accepted");
2521 if (flags & FLAG_VERBOSE) {
2522 c_write_str
2523 ("Authenticated using RSA key \"");
2524 c_write(commentp, commentlen);
2525 c_write_str("\" from agent\r\n");
2526 }
2527 authed = TRUE;
2528 } else
2529 logevent
2530 ("Pageant's response not accepted");
2531 } else {
2532 logevent
2533 ("Pageant failed to answer challenge");
2534 sfree(ret);
2535 }
2536 } else {
2537 logevent("No reply received from Pageant");
2538 }
2539 }
2540 freebn(key.exponent);
2541 freebn(key.modulus);
2542 freebn(challenge);
2543 if (authed)
2544 break;
2545 }
2546 }
2547 if (authed)
2548 break;
2549 }
2550 if (*cfg.keyfile && !tried_publickey)
2551 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2552
614a20a0 2553 if (cfg.try_tis_auth &&
2554 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2555 !tis_auth_refused) {
32874aea 2556 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2557 logevent("Requested TIS authentication");
2558 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2559 crWaitUntil(ispkt);
2560 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2561 logevent("TIS authentication declined");
2562 if (flags & FLAG_INTERACTIVE)
2563 c_write_str("TIS authentication refused.\r\n");
614a20a0 2564 tis_auth_refused = 1;
2565 continue;
32874aea 2566 } else {
2567 int challengelen = ((pktin.body[0] << 24) |
2568 (pktin.body[1] << 16) |
2569 (pktin.body[2] << 8) |
2570 (pktin.body[3]));
2571 logevent("Received TIS challenge");
2572 if (challengelen > sizeof(prompt) - 1)
2573 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2574 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2575 /* Prompt heuristic comes from OpenSSH */
2576 strncpy(prompt + challengelen,
2577 memchr(prompt, '\n', challengelen) ?
2578 "": "\r\nResponse: ",
2579 (sizeof prompt) - challengelen);
2580 prompt[(sizeof prompt) - 1] = '\0';
32874aea 2581 }
2582 }
614a20a0 2583 if (cfg.try_tis_auth &&
2584 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2585 !ccard_auth_refused) {
32874aea 2586 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2587 logevent("Requested CryptoCard authentication");
2588 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2589 crWaitUntil(ispkt);
2590 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2591 logevent("CryptoCard authentication declined");
2592 c_write_str("CryptoCard authentication refused.\r\n");
614a20a0 2593 ccard_auth_refused = 1;
2594 continue;
32874aea 2595 } else {
2596 int challengelen = ((pktin.body[0] << 24) |
2597 (pktin.body[1] << 16) |
2598 (pktin.body[2] << 8) |
2599 (pktin.body[3]));
2600 logevent("Received CryptoCard challenge");
2601 if (challengelen > sizeof(prompt) - 1)
2602 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2603 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2604 strncpy(prompt + challengelen,
2605 memchr(prompt, '\n', challengelen) ?
2606 "" : "\r\nResponse: ",
32874aea 2607 sizeof(prompt) - challengelen);
2608 prompt[sizeof(prompt) - 1] = '\0';
2609 }
2610 }
2611 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2612 sprintf(prompt, "%.90s@%.90s's password: ",
2613 username, savedhost);
2614 }
2615 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2616 char *comment = NULL;
231ee168 2617 int type;
2618 char msgbuf[256];
32874aea 2619 if (flags & FLAG_VERBOSE)
2620 c_write_str("Trying public key authentication.\r\n");
231ee168 2621 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2622 logevent(msgbuf);
2623 type = key_type(cfg.keyfile);
2624 if (type != SSH_KEYTYPE_SSH1) {
2625 sprintf(msgbuf, "Key is of wrong type (%s)",
2626 key_type_to_str(type));
2627 logevent(msgbuf);
2628 c_write_str(msgbuf);
2629 c_write_str("\r\n");
2630 tried_publickey = 1;
2631 continue;
2632 }
32874aea 2633 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2634 if (flags & FLAG_VERBOSE)
2635 c_write_str("No passphrase required.\r\n");
2636 goto tryauth;
2637 }
2638 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2639 sfree(comment);
2640 }
a52f067e 2641
614a20a0 2642 /*
2643 * Show password prompt, having first obtained it via a TIS
2644 * or CryptoCard exchange if we're doing TIS or CryptoCard
2645 * authentication.
2646 */
fa17a66e 2647 if (ssh_get_line) {
2648 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
32874aea 2649 /*
2650 * get_line failed to get a password (for example
2651 * because one was supplied on the command line
2652 * which has already failed to work). Terminate.
2653 */
2bc6a386 2654 send_packet(SSH1_MSG_DISCONNECT,
2655 PKT_STR, "No more passwords available to try",
2656 PKT_END);
247308b5 2657 logevent("Unable to authenticate");
2bc6a386 2658 connection_fatal("Unable to authenticate");
32874aea 2659 ssh_state = SSH_STATE_CLOSED;
2660 crReturn(1);
2661 }
fb09bf1c 2662 } else {
614a20a0 2663 /* Prompt may have come from server. We've munged it a bit, so
2664 * we know it to be zero-terminated at least once. */
0405e71f 2665 static int ret;
614a20a0 2666 c_write_untrusted(prompt, strlen(prompt));
32874aea 2667 pos = 0;
0405e71f 2668
2669 setup_userpass_input(password, sizeof(password), 0);
2670 do {
32874aea 2671 crWaitUntil(!ispkt);
0405e71f 2672 ret = process_userpass_input(in, inlen);
2673 } while (ret == 0);
2674 if (ret < 0)
2675 cleanup_exit(0);
32874aea 2676 c_write_str("\r\n");
2677 }
2678
2679 tryauth:
7cca0d81 2680 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2681 /*
2682 * Try public key authentication with the specified
2683 * key file.
2684 */
2685 static struct RSAKey pubkey;
2686 static Bignum challenge, response;
2687 static int i;
2688 static unsigned char buffer[32];
2689
2690 tried_publickey = 1;
2691 i = loadrsakey(cfg.keyfile, &pubkey, password);
2692 if (i == 0) {
7963af2f 2693 c_write_str("Couldn't load private key from ");
32874aea 2694 c_write_str(cfg.keyfile);
2695 c_write_str(".\r\n");
2696 continue; /* go and try password */
2697 }
2698 if (i == -1) {
2699 c_write_str("Wrong passphrase.\r\n");
2700 tried_publickey = 0;
2701 continue; /* try again */
2702 }
2703
2704 /*
2705 * Send a public key attempt.
2706 */
2707 send_packet(SSH1_CMSG_AUTH_RSA,
2708 PKT_BIGNUM, pubkey.modulus, PKT_END);
2709
2710 crWaitUntil(ispkt);
2711 if (pktin.type == SSH1_SMSG_FAILURE) {
2712 c_write_str("Server refused our public key.\r\n");
2713 continue; /* go and try password */
2714 }
2715 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2716 bombout(("Bizarre response to offer of public key"));
2717 crReturn(0);
2718 }
2719 ssh1_read_bignum(pktin.body, &challenge);
2720 response = rsadecrypt(challenge, &pubkey);
2721 freebn(pubkey.private_exponent); /* burn the evidence */
2722
2723 for (i = 0; i < 32; i++) {
2724 buffer[i] = bignum_byte(response, 31 - i);
2725 }
2726
2727 MD5Init(&md5c);
2728 MD5Update(&md5c, buffer, 32);
2729 MD5Update(&md5c, session_id, 16);
2730 MD5Final(buffer, &md5c);
2731
2732 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2733 PKT_DATA, buffer, 16, PKT_END);
2734
2735 crWaitUntil(ispkt);
2736 if (pktin.type == SSH1_SMSG_FAILURE) {
2737 if (flags & FLAG_VERBOSE)
2738 c_write_str
2739 ("Failed to authenticate with our public key.\r\n");
2740 continue; /* go and try password */
2741 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2742 bombout(
2743 ("Bizarre response to RSA authentication response"));
2744 crReturn(0);
2745 }
2746
2747 break; /* we're through! */
2748 } else {
2749 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2750 /*
2751 * Defence against traffic analysis: we send a
2752 * whole bunch of packets containing strings of
2753 * different lengths. One of these strings is the
2754 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2755 * The others are all random data in
2756 * SSH1_MSG_IGNORE packets. This way a passive
2757 * listener can't tell which is the password, and
2758 * hence can't deduce the password length.
2759 *
2760 * Anybody with a password length greater than 16
2761 * bytes is going to have enough entropy in their
2762 * password that a listener won't find it _that_
2763 * much help to know how long it is. So what we'll
2764 * do is:
2765 *
2766 * - if password length < 16, we send 15 packets
2767 * containing string lengths 1 through 15
2768 *
2769 * - otherwise, we let N be the nearest multiple
2770 * of 8 below the password length, and send 8
2771 * packets containing string lengths N through
2772 * N+7. This won't obscure the order of
2773 * magnitude of the password length, but it will
2774 * introduce a bit of extra uncertainty.
2775 *
2776 * A few servers (the old 1.2.18 through 1.2.22)
2777 * can't deal with SSH1_MSG_IGNORE. For these
2778 * servers, we need an alternative defence. We make
2779 * use of the fact that the password is interpreted
2780 * as a C string: so we can append a NUL, then some
2781 * random data.
bd358db1 2782 *
2783 * One server (a Cisco one) can deal with neither
2784 * SSH1_MSG_IGNORE _nor_ a padded password string.
2785 * For this server we are left with no defences
2786 * against password length sniffing.
32874aea 2787 */
bd358db1 2788 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2789 /*
2790 * The server can deal with SSH1_MSG_IGNORE, so
2791 * we can use the primary defence.
2792 */
32874aea 2793 int bottom, top, pwlen, i;
2794 char *randomstr;
2795
2796 pwlen = strlen(password);
2797 if (pwlen < 16) {
2798 bottom = 0; /* zero length passwords are OK! :-) */
2799 top = 15;
2800 } else {
2801 bottom = pwlen & ~7;
2802 top = bottom + 7;
2803 }
2804
2805 assert(pwlen >= bottom && pwlen <= top);
2806
2807 randomstr = smalloc(top + 1);
2808
2809 for (i = bottom; i <= top; i++) {
2810 if (i == pwlen)
2811 defer_packet(pwpkt_type, PKT_STR, password,
2812 PKT_END);
2813 else {
2814 for (j = 0; j < i; j++) {
2815 do {
2816 randomstr[j] = random_byte();
2817 } while (randomstr[j] == '\0');
2818 }
2819 randomstr[i] = '\0';
2820 defer_packet(SSH1_MSG_IGNORE,
2821 PKT_STR, randomstr, PKT_END);
2822 }
2823 }
bd358db1 2824 logevent("Sending password with camouflage packets");
32874aea 2825 ssh_pkt_defersend();
bd358db1 2826 }
2827 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2828 /*
2829 * The server can't deal with SSH1_MSG_IGNORE
2830 * but can deal with padded passwords, so we
2831 * can use the secondary defence.
2832 */
bd358db1 2833 char string[64];
2834 char *s;
2835 int len;
2836
2837 len = strlen(password);
2838 if (len < sizeof(string)) {
2839 s = string;
2840 strcpy(string, password);
2841 len++; /* cover the zero byte */
2842 while (len < sizeof(string)) {
2843 string[len++] = (char) random_byte();
2844 }
2845 } else {
2846 s = password;
2847 }
2848 logevent("Sending length-padded password");
2849 send_packet(pwpkt_type, PKT_INT, len,
2850 PKT_DATA, s, len, PKT_END);
2851 } else {
2852 /*
2853 * The server has _both_
2854 * BUG_CHOKES_ON_SSH1_IGNORE and
2855 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2856 * therefore nothing we can do.
2857 */
2858 int len;
2859 len = strlen(password);
2860 logevent("Sending unpadded password");
2861 send_packet(pwpkt_type, PKT_INT, len,
2862 PKT_DATA, password, len, PKT_END);
32874aea 2863 }
2864 } else {
2865 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2866 }
2867 }
c5e9c988 2868 logevent("Sent password");
374330e2 2869 memset(password, 0, strlen(password));
fb09bf1c 2870 crWaitUntil(ispkt);
e5574168 2871 if (pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2872 if (flags & FLAG_VERBOSE)
2873 c_write_str("Access denied\r\n");
c5e9c988 2874 logevent("Authentication refused");
e5574168 2875 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2876 logevent("Received disconnect request");
32874aea 2877 ssh_state = SSH_STATE_CLOSED;
85ee8208 2878 crReturn(1);
e5574168 2879 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2880 bombout(("Strange packet received, type %d", pktin.type));
32874aea 2881 crReturn(0);
374330e2 2882 }
2883 }
2884
c5e9c988 2885 logevent("Authentication successful");
2886
fb09bf1c 2887 crFinish(1);
2888}
2889
32874aea 2890void sshfwd_close(struct ssh_channel *c)
2891{
80e48603 2892 if (c && !c->closes) {
4ed34d25 2893 /*
2894 * If the channel's remoteid is -1, we have sent
2895 * CHANNEL_OPEN for this channel, but it hasn't even been
2896 * acknowledged by the server. So we must set a close flag
2897 * on it now, and then when the server acks the channel
2898 * open, we can close it then.
2899 */
36cac739 2900 if (((int)c->remoteid) != -1) {
4ed34d25 2901 if (ssh_version == 1) {
2902 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2903 PKT_END);
2904 } else {
2905 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2906 ssh2_pkt_adduint32(c->remoteid);
2907 ssh2_pkt_send();
2908 }
32874aea 2909 }
0357890f 2910 c->closes = 1; /* sent MSG_CLOSE */
32874aea 2911 if (c->type == CHAN_X11) {
2912 c->u.x11.s = NULL;
d74d141c 2913 logevent("Forwarded X11 connection terminated");
4ed34d25 2914 } else if (c->type == CHAN_SOCKDATA ||
2915 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2916 c->u.pfd.s = NULL;
2917 logevent("Forwarded port closed");
32874aea 2918 }
2919 }
2920}
2921
5471d09a 2922int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2923{
783415f8 2924 if (ssh_version == 1) {
32874aea 2925 send_packet(SSH1_MSG_CHANNEL_DATA,
2926 PKT_INT, c->remoteid,
2927 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2928 /*
2929 * In SSH1 we can return 0 here - implying that forwarded
2930 * connections are never individually throttled - because
2931 * the only circumstance that can cause throttling will be
2932 * the whole SSH connection backing up, in which case
2933 * _everything_ will be throttled as a whole.
2934 */
2935 return 0;
783415f8 2936 } else {
32874aea 2937 ssh2_add_channel_data(c, buf, len);
5471d09a 2938 return ssh2_try_send(c);
2939 }
2940}
2941
2942void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2943{
2944 if (ssh_version == 1) {
2945 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2946 c->v.v1.throttling = 0;
2947 ssh1_throttle(-1);
2948 }
2949 } else {
2950 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2951 }
9c964e85 2952}
2953
32874aea 2954static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2955{
fb09bf1c 2956 crBegin;
2957
2958 random_init();
2959
e5574168 2960 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2961 crReturnV;
85ee8208 2962 }
2963 if (ssh_state == SSH_STATE_CLOSED)
32874aea 2964 crReturnV;
fb09bf1c 2965
979310f1 2966 if (cfg.agentfwd && agent_exists()) {
32874aea 2967 logevent("Requesting agent forwarding");
2968 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2969 do {
2970 crReturnV;
2971 } while (!ispkt);
2972 if (pktin.type != SSH1_SMSG_SUCCESS
2973 && pktin.type != SSH1_SMSG_FAILURE) {
2974 bombout(("Protocol confusion"));
2975 crReturnV;
2976 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2977 logevent("Agent forwarding refused");
2978 } else {
2979 logevent("Agent forwarding enabled");
db7d555c 2980 ssh_agentfwd_enabled = TRUE;
2981 }
dacbd0e8 2982 }
2983
9c964e85 2984 if (cfg.x11_forward) {
32874aea 2985 char proto[20], data[64];
2986 logevent("Requesting X11 forwarding");
2987 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2988 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2989 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2990 PKT_STR, proto, PKT_STR, data,
2991 PKT_INT, 0, PKT_END);
2992 } else {
2993 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2994 PKT_STR, proto, PKT_STR, data, PKT_END);
2995 }
2996 do {
2997 crReturnV;
2998 } while (!ispkt);
2999 if (pktin.type != SSH1_SMSG_SUCCESS
3000 && pktin.type != SSH1_SMSG_FAILURE) {
3001 bombout(("Protocol confusion"));
3002 crReturnV;
3003 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3004 logevent("X11 forwarding refused");
3005 } else {
3006 logevent("X11 forwarding enabled");
9c964e85 3007 ssh_X11_fwd_enabled = TRUE;
3008 }
3009 }
3010
d74d141c 3011 {
9bf696b1 3012 char type;
3013 static char *e;
d74d141c 3014 int n;
a4fc0d74 3015 int sport,dport,sserv,dserv;
d74d141c 3016 char sports[256], dports[256], host[256];
3017 char buf[1024];
a4fc0d74 3018 struct servent *se;
d74d141c 3019
bc240b21 3020 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3021 /* Add port forwardings. */
3022 e = cfg.portfwd;
3023 while (*e) {
3024 type = *e++;
3025 n = 0;
3026 while (*e && *e != '\t')
3027 sports[n++] = *e++;
3028 sports[n] = 0;
3029 if (*e == '\t')
3030 e++;
3031 n = 0;
3032 while (*e && *e != ':')
3033 host[n++] = *e++;
3034 host[n] = 0;
3035 if (*e == ':')
3036 e++;
3037 n = 0;
3038 while (*e)
3039 dports[n++] = *e++;
3040 dports[n] = 0;
3041 e++;
3042 dport = atoi(dports);
a4fc0d74 3043 dserv = 0;
3044 if (dport == 0) {
3045 dserv = 1;
3046 se = getservbyname(dports, NULL);
3047 if (se != NULL) {
3048 dport = ntohs(se->s_port);
3049 } else {
3050 sprintf(buf,
3051 "Service lookup failed for destination port \"%s\"",
3052 dports);
3053 logevent(buf);
3054 }
3055 }
d74d141c 3056 sport = atoi(sports);
a4fc0d74 3057 sserv = 0;
3058 if (sport == 0) {
3059 sserv = 1;
3060 se = getservbyname(sports, NULL);
3061 if (se != NULL) {
3062 sport = ntohs(se->s_port);
3063 } else {
3064 sprintf(buf,
3065 "Service lookup failed for source port \"%s\"",
3066 sports);
3067 logevent(buf);
3068 }
3069 }
d74d141c 3070 if (sport && dport) {
3071 if (type == 'L') {
3072 pfd_addforward(host, dport, sport);
a4fc0d74 3073 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3074 " %s:%.*s%.*s%d%.*s",
3075 sserv ? strlen(sports) : 0, sports,
3076 sserv, "(", sport, sserv, ")",
3077 host,
3078 dserv ? strlen(dports) : 0, dports,
3079 dserv, "(", dport, dserv, ")");
d74d141c 3080 logevent(buf);
3081 } else {
3082 struct ssh_rportfwd *pf;
3083 pf = smalloc(sizeof(*pf));
bc240b21 3084 strcpy(pf->dhost, host);
3085 pf->dport = dport;
d74d141c 3086 if (add234(ssh_rportfwds, pf) != pf) {
3087 sprintf(buf,
95bc8819 3088 "Duplicate remote port forwarding to %s:%d",
d74d141c 3089 host, dport);
3090 logevent(buf);
bc240b21 3091 sfree(pf);
d74d141c 3092 } else {
a4fc0d74 3093 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3094 " forward to %s:%.*s%.*s%d%.*s",
3095 sserv ? strlen(sports) : 0, sports,
3096 sserv, "(", sport, sserv, ")",
3097 host,
3098 dserv ? strlen(dports) : 0, dports,
3099 dserv, "(", dport, dserv, ")");
d74d141c 3100 logevent(buf);
3101 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
3102 PKT_INT, sport,
3103 PKT_STR, host,
3104 PKT_INT, dport,
3105 PKT_END);
9bf696b1 3106 do {
3107 crReturnV;
3108 } while (!ispkt);
3109 if (pktin.type != SSH1_SMSG_SUCCESS
3110 && pktin.type != SSH1_SMSG_FAILURE) {
3111 bombout(("Protocol confusion"));
3112 crReturnV;
3113 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3114 c_write_str("Server refused port forwarding\r\n");
3115 ssh_editing = ssh_echoing = 1;
3116 }
3117 logevent("Remote port forwarding enabled");
d74d141c 3118 }
3119 }
3120 }
3121 }
3122 }
3123
fef97f43 3124 if (!cfg.nopty) {
e5574168 3125 send_packet(SSH1_CMSG_REQUEST_PTY,
32874aea 3126 PKT_STR, cfg.termtype,
3127 PKT_INT, rows, PKT_INT, cols,
3128 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3129 ssh_state = SSH_STATE_INTERMED;
3130 do {
3131 crReturnV;
3132 } while (!ispkt);
3133 if (pktin.type != SSH1_SMSG_SUCCESS
3134 && pktin.type != SSH1_SMSG_FAILURE) {
3135 bombout(("Protocol confusion"));
3136 crReturnV;
3137 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3138 c_write_str("Server refused to allocate pty\r\n");
3139 ssh_editing = ssh_echoing = 1;
3140 }
c5e9c988 3141 logevent("Allocated pty");
0965bee0 3142 } else {
32874aea 3143 ssh_editing = ssh_echoing = 1;
374330e2 3144 }
3145
4ba9b64b 3146 if (cfg.compression) {
32874aea 3147 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3148 do {
3149 crReturnV;
3150 } while (!ispkt);
3151 if (pktin.type != SSH1_SMSG_SUCCESS
3152 && pktin.type != SSH1_SMSG_FAILURE) {
3153 bombout(("Protocol confusion"));
3154 crReturnV;
3155 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3156 c_write_str("Server refused to compress\r\n");
3157 }
4ba9b64b 3158 logevent("Started compression");
3159 ssh1_compressing = TRUE;
3160 zlib_compress_init();
3161 zlib_decompress_init();
3162 }
3163
fd5e5847 3164 /*
3165 * Start the shell or command.
3166 *
3167 * Special case: if the first-choice command is an SSH2
3168 * subsystem (hence not usable here) and the second choice
3169 * exists, we fall straight back to that.
3170 */
3171 {
3172 char *cmd = cfg.remote_cmd_ptr;
3173
3174 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3175 cmd = cfg.remote_cmd_ptr2;
3176 ssh_fallback_cmd = TRUE;
3177 }
3178 if (*cmd)
3179 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3180 else
3181 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3182 logevent("Started session");
3183 }
374330e2 3184
3185 ssh_state = SSH_STATE_SESSION;
3186 if (size_needed)
3187 ssh_size();
3687d221 3188 if (eof_needed)
32874aea 3189 ssh_special(TS_EOF);
374330e2 3190
760e88b2 3191 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 3192 ssh_send_ok = 1;
dacbd0e8 3193 ssh_channels = newtree234(ssh_channelcmp);
374330e2 3194 while (1) {
3195 crReturnV;
3196 if (ispkt) {
e5574168 3197 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 3198 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 3199 long len = GET_32BIT(pktin.body);
5471d09a 3200 int bufsize =
3201 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
3202 pktin.body + 4, len);
90347b95 3203 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3204 ssh1_stdout_throttling = 1;
3205 ssh1_throttle(+1);
3206 }
e5574168 3207 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
32874aea 3208 ssh_state = SSH_STATE_CLOSED;
c5e9c988 3209 logevent("Received disconnect request");
32874aea 3210 crReturnV;
3211 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3212 /* Remote side is trying to open a channel to talk to our
3213 * X-Server. Give them back a local channel number. */
3214 struct ssh_channel *c;
9c964e85 3215
3216 logevent("Received X11 connect request");
3217 /* Refuse if X11 forwarding is disabled. */
3218 if (!ssh_X11_fwd_enabled) {
3219 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 3220 PKT_INT, GET_32BIT(pktin.body), PKT_END);
9c964e85 3221 logevent("Rejected X11 connect request");
3222 } else {
9c964e85 3223 c = smalloc(sizeof(struct ssh_channel));
3224
32874aea 3225 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3226 logevent("opening X11 forward connection failed");
3227 sfree(c);
3228 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3229 PKT_INT, GET_32BIT(pktin.body),
3230 PKT_END);
9c964e85 3231 } else {
32874aea 3232 logevent
3233 ("opening X11 forward connection succeeded");
3234 c->remoteid = GET_32BIT(pktin.body);
3235 c->localid = alloc_channel_id();
3236 c->closes = 0;
5471d09a 3237 c->v.v1.throttling = 0;
32874aea 3238 c->type = CHAN_X11; /* identify channel type */
3239 add234(ssh_channels, c);
3240 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3241 PKT_INT, c->remoteid, PKT_INT,
3242 c->localid, PKT_END);
3243 logevent("Opened X11 forward channel");
9c964e85 3244 }
3245 }
32874aea 3246 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3247 /* Remote side is trying to open a channel to talk to our
3248 * agent. Give them back a local channel number. */
3249 struct ssh_channel *c;
db7d555c 3250
3251 /* Refuse if agent forwarding is disabled. */
3252 if (!ssh_agentfwd_enabled) {
3253 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 3254 PKT_INT, GET_32BIT(pktin.body), PKT_END);
db7d555c 3255 } else {
dcbde236 3256 c = smalloc(sizeof(struct ssh_channel));
db7d555c 3257 c->remoteid = GET_32BIT(pktin.body);
d2371c81 3258 c->localid = alloc_channel_id();
db7d555c 3259 c->closes = 0;
5471d09a 3260 c->v.v1.throttling = 0;
32874aea 3261 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3262 c->u.a.lensofar = 0;
3263 add234(ssh_channels, c);
3264 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3265 PKT_INT, c->remoteid, PKT_INT, c->localid,
3266 PKT_END);
3267 }
d74d141c 3268 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3269 /* Remote side is trying to open a channel to talk to a
3270 * forwarded port. Give them back a local channel number. */
3271 struct ssh_channel *c;
3272 struct ssh_rportfwd pf;
3273 int hostsize, port;
3274 char host[256], buf[1024];
3275 char *p, *h, *e;
3276 c = smalloc(sizeof(struct ssh_channel));
3277
3278 hostsize = GET_32BIT(pktin.body+4);
3279 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3280 if (h+1 < host+sizeof(host))
3281 *h++ = *p;
95bc8819 3282 p++;
d74d141c 3283 }
3284 *h = 0;
3285 port = GET_32BIT(p);
3286
bc240b21 3287 strcpy(pf.dhost, host);
3288 pf.dport = port;
d74d141c 3289
3290 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3291 sprintf(buf, "Rejected remote port open request for %s:%d",
3292 host, port);
3293 logevent(buf);
3294 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3295 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3296 } else {
3297 sprintf(buf, "Received remote port open request for %s:%d",
3298 host, port);
3299 logevent(buf);
3300 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3301 if (e != NULL) {
3302 char buf[256];
3303 sprintf(buf, "Port open failed: %s", e);
3304 logevent(buf);
3305 sfree(c);
3306 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3307 PKT_INT, GET_32BIT(pktin.body),
3308 PKT_END);
3309 } else {
3310 c->remoteid = GET_32BIT(pktin.body);
3311 c->localid = alloc_channel_id();
3312 c->closes = 0;
5471d09a 3313 c->v.v1.throttling = 0;
d74d141c 3314 c->type = CHAN_SOCKDATA; /* identify channel type */
3315 add234(ssh_channels, c);
3316 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3317 PKT_INT, c->remoteid, PKT_INT,
3318 c->localid, PKT_END);
3319 logevent("Forwarded port opened successfully");
3320 }
3321 }
3322
3323 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
bc240b21 3324 unsigned int remoteid = GET_32BIT(pktin.body);
3325 unsigned int localid = GET_32BIT(pktin.body+4);
3326 struct ssh_channel *c;
3327
3328 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3329 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3330 c->remoteid = localid;
3331 c->type = CHAN_SOCKDATA;
7781f316 3332 c->v.v1.throttling = 0;
bc240b21 3333 pfd_confirm(c->u.pfd.s);
3334 }
d74d141c 3335
4ed34d25 3336 if (c && c->closes) {
3337 /*
3338 * We have a pending close on this channel,
3339 * which we decided on before the server acked
3340 * the channel open. So now we know the
3341 * remoteid, we can close it again.
3342 */
3343 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3344 PKT_END);
3345 }
3346
724cface 3347 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3348 unsigned int remoteid = GET_32BIT(pktin.body);
3349 unsigned int localid = GET_32BIT(pktin.body+4);
3350 struct ssh_channel *c;
3351
3352 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3353 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3354 logevent("Forwarded connection refused by server");
3355 pfd_close(c->u.pfd.s);
3356 del234(ssh_channels, c);
3357 sfree(c);
3358 }
3359
db7d555c 3360 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3361 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3362 /* Remote side closes a channel. */
3363 unsigned i = GET_32BIT(pktin.body);
3364 struct ssh_channel *c;
3365 c = find234(ssh_channels, &i, ssh_channelfind);
d0d844c1 3366 if (c && ((int)c->remoteid) != -1) {
32874aea 3367 int closetype;
3368 closetype =
3369 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3370
783415f8 3371 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3372 logevent("Forwarded X11 connection terminated");
9c964e85 3373 assert(c->u.x11.s != NULL);
3374 x11_close(c->u.x11.s);
3375 c->u.x11.s = NULL;
3376 }
d74d141c 3377 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3378 logevent("Forwarded port closed");
3379 assert(c->u.pfd.s != NULL);
3380 pfd_close(c->u.pfd.s);
3381 c->u.pfd.s = NULL;
3382 }
0357890f 3383
3384 c->closes |= (closetype << 2); /* seen this message */
3385 if (!(c->closes & closetype)) {
3386 send_packet(pktin.type, PKT_INT, c->remoteid,
3387 PKT_END);
3388 c->closes |= closetype; /* sent it too */
3389 }
3390
3391 if (c->closes == 15) {
32874aea 3392 del234(ssh_channels, c);
3393 sfree(c);
3394 }
d0d844c1 3395 } else {
3396 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3397 pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3398 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3399 i));
32874aea 3400 }
3401 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3402 /* Data sent down one of our channels. */
3403 int i = GET_32BIT(pktin.body);
3404 int len = GET_32BIT(pktin.body + 4);
3405 unsigned char *p = pktin.body + 8;
3406 struct ssh_channel *c;
3407 c = find234(ssh_channels, &i, ssh_channelfind);
3408 if (c) {
5471d09a 3409 int bufsize;
32874aea 3410 switch (c->type) {
3411 case CHAN_X11:
5471d09a 3412 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 3413 break;
d74d141c 3414 case CHAN_SOCKDATA:
5471d09a 3415 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 3416 break;
32874aea 3417 case CHAN_AGENT:
3418 /* Data for an agent message. Buffer it. */
3419 while (len > 0) {
3420 if (c->u.a.lensofar < 4) {
3421 int l = min(4 - c->u.a.lensofar, len);
3422 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3423 l);
3424 p += l;
3425 len -= l;
3426 c->u.a.lensofar += l;
3427 }
3428 if (c->u.a.lensofar == 4) {
3429 c->u.a.totallen =
3430 4 + GET_32BIT(c->u.a.msglen);
3431 c->u.a.message = smalloc(c->u.a.totallen);
3432 memcpy(c->u.a.message, c->u.a.msglen, 4);
3433 }
3434 if (c->u.a.lensofar >= 4 && len > 0) {
3435 int l =
3436 min(c->u.a.totallen - c->u.a.lensofar,
3437 len);
3438 memcpy(c->u.a.message + c->u.a.lensofar, p,
3439 l);
3440 p += l;
3441 len -= l;
3442 c->u.a.lensofar += l;
3443 }
3444 if (c->u.a.lensofar == c->u.a.totallen) {
3445 void *reply, *sentreply;
3446 int replylen;
3447 agent_query(c->u.a.message,
3448 c->u.a.totallen, &reply,
3449 &replylen);
3450 if (reply)
3451 sentreply = reply;
3452 else {
3453 /* Fake SSH_AGENT_FAILURE. */
3454 sentreply = "\0\0\0\1\5";
3455 replylen = 5;
3456 }
3457 send_packet(SSH1_MSG_CHANNEL_DATA,
3458 PKT_INT, c->remoteid,
3459 PKT_INT, replylen,
3460 PKT_DATA, sentreply, replylen,
3461 PKT_END);
3462 if (reply)
3463 sfree(reply);
3464 sfree(c->u.a.message);
3465 c->u.a.lensofar = 0;
3466 }
3467 }
5471d09a 3468 bufsize = 0; /* agent channels never back up */
32874aea 3469 break;
3470 }
90347b95 3471 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3472 c->v.v1.throttling = 1;
3473 ssh1_throttle(+1);
3474 }
32874aea 3475 }
e5574168 3476 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3477 /* may be from EXEC_SHELL on some servers */
e5574168 3478 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3479 /* may be from EXEC_SHELL on some servers
374330e2 3480 * if no pty is available or in other odd cases. Ignore */
e5574168 3481 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3482 char buf[100];
3483 ssh_exitcode = GET_32BIT(pktin.body);
3484 sprintf(buf, "Server sent command exit status %d",
3485 ssh_exitcode);
3486 logevent(buf);
e5574168 3487 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3488 /*
3489 * In case `helpful' firewalls or proxies tack
3490 * extra human-readable text on the end of the
3491 * session which we might mistake for another
3492 * encrypted packet, we close the session once
3493 * we've sent EXIT_CONFIRMATION.
3494 */
3495 ssh_state = SSH_STATE_CLOSED;
3496 crReturnV;
374330e2 3497 } else {
8d5de777 3498 bombout(("Strange packet received: type %d", pktin.type));
32874aea 3499 crReturnV;
374330e2 3500 }
3501 } else {
8df7a775 3502 while (inlen > 0) {
3503 int len = min(inlen, 512);
3504 send_packet(SSH1_CMSG_STDIN_DATA,
3505 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3506 in += len;
3507 inlen -= len;
3508 }
374330e2 3509 }
3510 }
3511
3512 crFinishV;
3513}
3514
3515/*
e5574168 3516 * Utility routine for decoding comma-separated strings in KEXINIT.
3517 */
32874aea 3518static int in_commasep_string(char *needle, char *haystack, int haylen)
3519{
e5574168 3520 int needlen = strlen(needle);
3521 while (1) {
32874aea 3522 /*
3523 * Is it at the start of the string?
3524 */
3525 if (haylen >= needlen && /* haystack is long enough */
3526 !memcmp(needle, haystack, needlen) && /* initial match */
3527 (haylen == needlen || haystack[needlen] == ',')
3528 /* either , or EOS follows */
3529 )
3530 return 1;
3531 /*
3532 * If not, search for the next comma and resume after that.
3533 * If no comma found, terminate.
3534 */
3535 while (haylen > 0 && *haystack != ',')
3536 haylen--, haystack++;
3537 if (haylen == 0)
3538 return 0;
3539 haylen--, haystack++; /* skip over comma itself */
e5574168 3540 }
3541}
3542
3543/*
d39f364a 3544 * SSH2 key creation method.
3545 */
32874aea 3546static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3547 char *keyspace)
3548{
d39f364a 3549 SHA_State s;
3550 /* First 20 bytes. */
3551 SHA_Init(&s);
088bde77 3552 if (!(ssh_remote_bugs & BUG_SSH2_DERIVEKEY))
3553 sha_mpint(&s, K);
d39f364a 3554 SHA_Bytes(&s, H, 20);
3555 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3556 SHA_Bytes(&s, sessid, 20);
d39f364a 3557 SHA_Final(&s, keyspace);
3558 /* Next 20 bytes. */
3559 SHA_Init(&s);
088bde77 3560 if (!(ssh_remote_bugs & BUG_SSH2_DERIVEKEY))
3561 sha_mpint(&s, K);
d39f364a 3562 SHA_Bytes(&s, H, 20);
3563 SHA_Bytes(&s, keyspace, 20);
32874aea 3564 SHA_Final(&s, keyspace + 20);
d39f364a 3565}
3566
3567/*
7cca0d81 3568 * Handle the SSH2 transport layer.
e5574168 3569 */
7cca0d81 3570static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 3571{
ca20bfcf 3572 static int i, j, len, nbits, pbits, warn;
e5574168 3573 static char *str;
a92dd380 3574 static Bignum p, g, e, f, K;
3575 static int kex_init_value, kex_reply_value;
7591b9ff 3576 static const struct ssh_mac **maclist;
8b2715b2 3577 static int nmacs;
0a3f1d48 3578 static const struct ssh2_cipher *cscipher_tobe = NULL;
3579 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 3580 static const struct ssh_mac *csmac_tobe = NULL;
3581 static const struct ssh_mac *scmac_tobe = NULL;
3582 static const struct ssh_compress *cscomp_tobe = NULL;
3583 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 3584 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 3585 static int hostkeylen, siglen;
e055a386 3586 static void *hkey; /* actual host key */
e5574168 3587 static unsigned char exchange_hash[20];
d39f364a 3588 static unsigned char keyspace[40];
ca20bfcf 3589 static int n_preferred_ciphers;
3590 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4ba9b64b 3591 static const struct ssh_compress *preferred_comp;
087abe1a 3592 static int cipherstr_started;
0db56f73 3593 static int first_kex;
e5574168 3594
3595 crBegin;
7cca0d81 3596 random_init();
0db56f73 3597 first_kex = 1;
e5574168 3598
5e8358ad 3599 /*
ca20bfcf 3600 * Set up the preferred ciphers. (NULL => warn below here)
5e8358ad 3601 */
ca20bfcf 3602 n_preferred_ciphers = 0;
3603 for (i = 0; i < CIPHER_MAX; i++) {
3604 switch (cfg.ssh_cipherlist[i]) {
3605 case CIPHER_BLOWFISH:
3606 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3607 n_preferred_ciphers++;
3608 break;
3609 case CIPHER_DES:
087abe1a 3610 if (cfg.ssh2_des_cbc) {
3611 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3612 n_preferred_ciphers++;
3613 }
ca20bfcf 3614 break;
3615 case CIPHER_3DES:
3616 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3617 n_preferred_ciphers++;
3618 break;
3619 case CIPHER_AES:
3620 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3621 n_preferred_ciphers++;
3622 break;
3623 case CIPHER_WARN:
3624 /* Flag for later. Don't bother if it's the last in
3625 * the list. */
3626 if (i < CIPHER_MAX - 1) {
3627 preferred_ciphers[n_preferred_ciphers] = NULL;
3628 n_preferred_ciphers++;
3629 }
3630 break;
3631 }
5e8358ad 3632 }
ca20bfcf 3633
3634 /*
3635 * Set up preferred compression.
3636 */
4ba9b64b 3637 if (cfg.compression)
3638 preferred_comp = &ssh_zlib;
3639 else
3640 preferred_comp = &ssh_comp_none;
5e8358ad 3641
7591b9ff 3642 /*
3643 * Be prepared to work around the buggy MAC problem.
3644 */
1b56c055 3645 if (ssh_remote_bugs & BUG_SSH2_HMAC)
32874aea 3646 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 3647 else
32874aea 3648 maclist = macs, nmacs = lenof(macs);
7591b9ff 3649
32874aea 3650 begin_key_exchange:
e5574168 3651 /*
3652 * Construct and send our key exchange packet.
3653 */
3654 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3655 for (i = 0; i < 16; i++)
32874aea 3656 ssh2_pkt_addbyte((unsigned char) random_byte());
e5574168 3657 /* List key exchange algorithms. */
3658 ssh2_pkt_addstring_start();
3659 for (i = 0; i < lenof(kex_algs); i++) {
8e975795 3660 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3661 (ssh_remote_bugs & BUG_SSH2_DH_GEX))
3662 continue;
32874aea 3663 ssh2_pkt_addstring_str(kex_algs[i]->name);
3664 if (i < lenof(kex_algs) - 1)
3665 ssh2_pkt_addstring_str(",");
e5574168 3666 }
3667 /* List server host key algorithms. */
3668 ssh2_pkt_addstring_start();
3669 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3670 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3671 if (i < lenof(hostkey_algs) - 1)
3672 ssh2_pkt_addstring_str(",");
e5574168 3673 }
3674 /* List client->server encryption algorithms. */
3675 ssh2_pkt_addstring_start();
087abe1a 3676 cipherstr_started = 0;
ca20bfcf 3677 for (i = 0; i < n_preferred_ciphers; i++) {
3678 const struct ssh2_ciphers *c = preferred_ciphers[i];
3679 if (!c) continue; /* warning flag */
32874aea 3680 for (j = 0; j < c->nciphers; j++) {
087abe1a 3681 if (cipherstr_started)
32874aea 3682 ssh2_pkt_addstring_str(",");
087abe1a 3683 ssh2_pkt_addstring_str(c->list[j]->name);
3684 cipherstr_started = 1;
32874aea 3685 }
e5574168 3686 }
3687 /* List server->client encryption algorithms. */
3688 ssh2_pkt_addstring_start();
087abe1a 3689 cipherstr_started = 0;
ca20bfcf 3690 for (i = 0; i < n_preferred_ciphers; i++) {
3691 const struct ssh2_ciphers *c = preferred_ciphers[i];
3692 if (!c) continue; /* warning flag */
32874aea 3693 for (j = 0; j < c->nciphers; j++) {
087abe1a 3694 if (cipherstr_started)
32874aea 3695 ssh2_pkt_addstring_str(",");
087abe1a 3696 ssh2_pkt_addstring_str(c->list[j]->name);
3697 cipherstr_started = 1;
32874aea 3698 }
e5574168 3699 }
3700 /* List client->server MAC algorithms. */
3701 ssh2_pkt_addstring_start();
8b2715b2 3702 for (i = 0; i < nmacs; i++) {
32874aea 3703 ssh2_pkt_addstring_str(maclist[i]->name);
3704 if (i < nmacs - 1)
3705 ssh2_pkt_addstring_str(",");
e5574168 3706 }
3707 /* List server->client MAC algorithms. */
3708 ssh2_pkt_addstring_start();
8b2715b2 3709 for (i = 0; i < nmacs; i++) {
32874aea 3710 ssh2_pkt_addstring_str(maclist[i]->name);
3711 if (i < nmacs - 1)
3712 ssh2_pkt_addstring_str(",");
e5574168 3713 }
3714 /* List client->server compression algorithms. */
3715 ssh2_pkt_addstring_start();
32874aea 3716 for (i = 0; i < lenof(compressions) + 1; i++) {
3717 const struct ssh_compress *c =
3718 i == 0 ? preferred_comp : compressions[i - 1];
3719 ssh2_pkt_addstring_str(c->name);
3720 if (i < lenof(compressions))
3721 ssh2_pkt_addstring_str(",");
e5574168 3722 }
3723 /* List server->client compression algorithms. */
3724 ssh2_pkt_addstring_start();
32874aea 3725 for (i = 0; i < lenof(compressions) + 1; i++) {
3726 const struct ssh_compress *c =
3727 i == 0 ? preferred_comp : compressions[i - 1];
3728 ssh2_pkt_addstring_str(c->name);
3729 if (i < lenof(compressions))
3730 ssh2_pkt_addstring_str(",");
e5574168 3731 }
3732 /* List client->server languages. Empty list. */
3733 ssh2_pkt_addstring_start();
3734 /* List server->client languages. Empty list. */
3735 ssh2_pkt_addstring_start();
3736 /* First KEX packet does _not_ follow, because we're not that brave. */
3737 ssh2_pkt_addbool(FALSE);
3738 /* Reserved. */
3739 ssh2_pkt_adduint32(0);
0db56f73 3740
3741 exhash = exhashbase;
32874aea 3742 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
0db56f73 3743
e5574168 3744 ssh2_pkt_send();
3745
32874aea 3746 if (!ispkt)
3747 crWaitUntil(ispkt);
3748 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
e5574168 3749
3750 /*
3751 * Now examine the other side's KEXINIT to see what we're up
3752 * to.
3753 */
7cca0d81 3754 if (pktin.type != SSH2_MSG_KEXINIT) {
32874aea 3755 bombout(("expected key exchange packet from server"));
3756 crReturn(0);
7cca0d81 3757 }
32874aea 3758 kex = NULL;
3759 hostkey = NULL;
3760 cscipher_tobe = NULL;
3761 sccipher_tobe = NULL;
3762 csmac_tobe = NULL;
3763 scmac_tobe = NULL;
3764 cscomp_tobe = NULL;
3765 sccomp_tobe = NULL;
3766 pktin.savedpos += 16; /* skip garbage cookie */
e5574168 3767 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3768 for (i = 0; i < lenof(kex_algs); i++) {
8e975795 3769 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3770 (ssh_remote_bugs & BUG_SSH2_DH_GEX))
3771 continue;
32874aea 3772 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3773 kex = kex_algs[i];
3774 break;
3775 }
e5574168 3776 }
3777 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3778 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3779 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3780 hostkey = hostkey_algs[i];
3781 break;
3782 }
e5574168 3783 }
3784 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
ca20bfcf 3785 warn = 0;
3786 for (i = 0; i < n_preferred_ciphers; i++) {
3787 const struct ssh2_ciphers *c = preferred_ciphers[i];
3788 if (!c) {
3789 warn = 1;
3790 } else {
3791 for (j = 0; j < c->nciphers; j++) {
3792 if (in_commasep_string(c->list[j]->name, str, len)) {
3793 cscipher_tobe = c->list[j];
3794 break;
3795 }
32874aea 3796 }
3797 }
ca20bfcf 3798 if (cscipher_tobe) {
3799 if (warn)
3800 askcipher(cscipher_tobe->name, 1);
32874aea 3801 break;
ca20bfcf 3802 }
e5574168 3803 }
0ef8f407 3804 if (!cscipher_tobe) {
3805 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3806 crReturn(0);
3807 }
3808
e5574168 3809 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
ca20bfcf 3810 warn = 0;
3811 for (i = 0; i < n_preferred_ciphers; i++) {
3812 const struct ssh2_ciphers *c = preferred_ciphers[i];
3813 if (!c) {
3814 warn = 1;
3815 } else {
3816 for (j = 0; j < c->nciphers; j++) {
3817 if (in_commasep_string(c->list[j]->name, str, len)) {
3818 sccipher_tobe = c->list[j];
3819 break;
3820 }
32874aea 3821 }
3822 }
ca20bfcf 3823 if (sccipher_tobe) {
3824 if (warn)
3825 askcipher(sccipher_tobe->name, 2);
32874aea 3826 break;
ca20bfcf 3827 }
e5574168 3828 }
0ef8f407 3829 if (!sccipher_tobe) {
3830 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3831 crReturn(0);
3832 }
3833
e5574168 3834 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 3835 for (i = 0; i < nmacs; i++) {
32874aea 3836 if (in_commasep_string(maclist[i]->name, str, len)) {
3837 csmac_tobe = maclist[i];
3838 break;
3839 }
e5574168 3840 }
3841 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 3842 for (i = 0; i < nmacs; i++) {
32874aea 3843 if (in_commasep_string(maclist[i]->name, str, len)) {
3844 scmac_tobe = maclist[i];
3845 break;
3846 }
e5574168 3847 }
3848 ssh2_pkt_getstring(&str, &len); /* client->server compression */
32874aea 3849 for (i = 0; i < lenof(compressions) + 1; i++) {
3850 const struct ssh_compress *c =
3851 i == 0 ? preferred_comp : compressions[i - 1];
3852 if (in_commasep_string(c->name, str, len)) {
3853 cscomp_tobe = c;
3854 break;
3855 }
e5574168 3856 }
3857 ssh2_pkt_getstring(&str, &len); /* server->client compression */
32874aea 3858 for (i = 0; i < lenof(compressions) + 1; i++) {
3859 const struct ssh_compress *c =
3860 i == 0 ? preferred_comp : compressions[i - 1];
3861 if (in_commasep_string(c->name, str, len)) {
3862 sccomp_tobe = c;
3863 break;
3864 }
e5574168 3865 }
e5574168 3866
3867 /*
7bd5a860 3868 * Work out the number of bits of key we will need from the key
3869 * exchange. We start with the maximum key length of either
3870 * cipher...
3871 */
3872 {
32874aea 3873 int csbits, scbits;
7bd5a860 3874
3875 csbits = cscipher_tobe->keylen;
3876 scbits = sccipher_tobe->keylen;
3877 nbits = (csbits > scbits ? csbits : scbits);
3878 }
3879 /* The keys only have 160-bit entropy, since they're based on
3880 * a SHA-1 hash. So cap the key size at 160 bits. */
32874aea 3881 if (nbits > 160)
3882 nbits = 160;
7bd5a860 3883
3884 /*
a92dd380 3885 * If we're doing Diffie-Hellman group exchange, start by
3886 * requesting a group.
e5574168 3887 */
a92dd380 3888 if (kex == &ssh_diffiehellman_gex) {
32874aea 3889 logevent("Doing Diffie-Hellman group exchange");
00db133f 3890 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 3891 /*
3892 * Work out how big a DH group we will need to allow that
3893 * much data.
7bd5a860 3894 */
32874aea 3895 pbits = 512 << ((nbits - 1) / 64);
3896 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3897 ssh2_pkt_adduint32(pbits);
3898 ssh2_pkt_send();
3899
3900 crWaitUntil(ispkt);
3901 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3902 bombout(("expected key exchange group packet from server"));
3903 crReturn(0);
3904 }
3905 p = ssh2_pkt_getmp();
3906 g = ssh2_pkt_getmp();
3907 dh_setup_group(p, g);
3908 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3909 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3910 } else {
00db133f 3911 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
32874aea 3912 dh_setup_group1();
3913 kex_init_value = SSH2_MSG_KEXDH_INIT;
3914 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3915 }
e5574168 3916
a92dd380 3917 logevent("Doing Diffie-Hellman key exchange");
e5574168 3918 /*
a92dd380 3919 * Now generate and send e for Diffie-Hellman.
e5574168 3920 */
32874aea 3921 e = dh_create_e(nbits * 2);
a92dd380 3922 ssh2_pkt_init(kex_init_value);
e5574168 3923 ssh2_pkt_addmp(e);
3924 ssh2_pkt_send();
3925
3926 crWaitUntil(ispkt);
a92dd380 3927 if (pktin.type != kex_reply_value) {
32874aea 3928 bombout(("expected key exchange reply packet from server"));
3929 crReturn(0);
7cca0d81 3930 }
e5574168 3931 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3932 f = ssh2_pkt_getmp();
e5574168 3933 ssh2_pkt_getstring(&sigdata, &siglen);
3934
3935 K = dh_find_K(f);
e5574168 3936
3937 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 3938 if (kex == &ssh_diffiehellman_gex) {
32874aea 3939 sha_uint32(&exhash, pbits);
3940 sha_mpint(&exhash, p);
3941 sha_mpint(&exhash, g);
a92dd380 3942 }
e5574168 3943 sha_mpint(&exhash, e);
3944 sha_mpint(&exhash, f);
3945 sha_mpint(&exhash, K);
3946 SHA_Final(&exhash, exchange_hash);
3947
3709bfe9 3948 dh_cleanup();
3949
7cca0d81 3950#if 0
765c4200 3951 debug(("Exchange hash is:\n"));
3952 dmemdump(exchange_hash, 20);
7cca0d81 3953#endif
3954
e055a386 3955 hkey = hostkey->newkey(hostkeydata, hostkeylen);
f7259d10 3956 if (!hkey ||
3957 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3958 bombout(("Server's host key did not match the signature supplied"));
32874aea 3959 crReturn(0);
8d5de777 3960 }
e5574168 3961
3962 /*
7cca0d81 3963 * Authenticate remote host: verify host key. (We've already
3964 * checked the signature of the exchange hash.)
e5574168 3965 */
e055a386 3966 keystr = hostkey->fmtkey(hkey);
3967 fingerprint = hostkey->fingerprint(hkey);
d4857987 3968 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
32874aea 3969 keystr, fingerprint);
3970 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 3971 logevent("Host key fingerprint is:");
3972 logevent(fingerprint);
3973 }
dcbde236 3974 sfree(fingerprint);
3975 sfree(keystr);
e055a386 3976 hostkey->freekey(hkey);
d39f364a 3977
3978 /*
7cca0d81 3979 * Send SSH2_MSG_NEWKEYS.
d39f364a 3980 */
3981 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3982 ssh2_pkt_send();
d39f364a 3983
3984 /*
8406eaf9 3985 * Expect SSH2_MSG_NEWKEYS from server.
3986 */
3987 crWaitUntil(ispkt);
3988 if (pktin.type != SSH2_MSG_NEWKEYS) {
3989 bombout(("expected new-keys packet from server"));
3990 crReturn(0);
3991 }
3992
3993 /*
d39f364a 3994 * Create and initialise session keys.
3995 */
3996 cscipher = cscipher_tobe;
3997 sccipher = sccipher_tobe;
3998 csmac = csmac_tobe;
3999 scmac = scmac_tobe;
4000 cscomp = cscomp_tobe;
4001 sccomp = sccomp_tobe;
4ba9b64b 4002 cscomp->compress_init();
4003 sccomp->decompress_init();
d39f364a 4004 /*
5e0d7cb8 4005 * Set IVs after keys. Here we use the exchange hash from the
4006 * _first_ key exchange.
d39f364a 4007 */
5e0d7cb8 4008 if (first_kex)
65a22376 4009 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
4010 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 4011 cscipher->setcskey(keyspace);
65a22376 4012 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 4013 sccipher->setsckey(keyspace);
65a22376 4014 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 4015 cscipher->setcsiv(keyspace);
65a22376 4016 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 4017 sccipher->setsciv(keyspace);
65a22376 4018 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 4019 csmac->setcskey(keyspace);
65a22376 4020 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 4021 scmac->setsckey(keyspace);
d39f364a 4022
033b4cef 4023 /*
0db56f73 4024 * If this is the first key exchange phase, we must pass the
4025 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4026 * wants to see it but because it will need time to initialise
4027 * itself before it sees an actual packet. In subsequent key
4028 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4029 * it would only confuse the layer above.
4030 */
4031 if (!first_kex) {
32874aea 4032 crReturn(0);
0db56f73 4033 }
4034 first_kex = 0;
4035
4036 /*
7cca0d81 4037 * Now we're encrypting. Begin returning 1 to the protocol main
4038 * function so that other things can run on top of the
4039 * transport. If we ever see a KEXINIT, we must go back to the
4040 * start.
033b4cef 4041 */
e96adf72 4042 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4043 crReturn(1);
e96adf72 4044 }
5e0d7cb8 4045 logevent("Server initiated key re-exchange");
7cca0d81 4046 goto begin_key_exchange;
e5574168 4047
4048 crFinish(1);
4049}
4050
7cca0d81 4051/*
783415f8 4052 * Add data to an SSH2 channel output buffer.
4053 */
32874aea 4054static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4055 int len)
4056{
5471d09a 4057 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4058}
4059
4060/*
4061 * Attempt to send data on an SSH2 channel.
4062 */
5471d09a 4063static int ssh2_try_send(struct ssh_channel *c)
32874aea 4064{
5471d09a 4065 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4066 int len;
4067 void *data;
4068 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4069 if ((unsigned)len > c->v.v2.remwindow)
4070 len = c->v.v2.remwindow;
4071 if ((unsigned)len > c->v.v2.remmaxpkt)
4072 len = c->v.v2.remmaxpkt;
32874aea 4073 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4074 ssh2_pkt_adduint32(c->remoteid);
4075 ssh2_pkt_addstring_start();
5471d09a 4076 ssh2_pkt_addstring_data(data, len);
32874aea 4077 ssh2_pkt_send();
5471d09a 4078 bufchain_consume(&c->v.v2.outbuffer, len);
4079 c->v.v2.remwindow -= len;
4080 }
4081
4082 /*
4083 * After having sent as much data as we can, return the amount
4084 * still buffered.
4085 */
4086 return bufchain_size(&c->v.v2.outbuffer);
4087}
4088
4089/*
4090 * Potentially enlarge the window on an SSH2 channel.
4091 */
4092static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4093{
6b69f42e 4094 /*
4095 * Never send WINDOW_ADJUST for a channel that the remote side
4096 * already thinks it's closed; there's no point, since it won't
4097 * be sending any more data anyway.
4098 */
4099 if (c->closes != 0)
4100 return;
4101
5471d09a 4102 if (newwin > c->v.v2.locwindow) {
4103 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4104 ssh2_pkt_adduint32(c->remoteid);
4105 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
4106 ssh2_pkt_send();
4107 c->v.v2.locwindow = newwin;
783415f8 4108 }
4109}
4110
4111/*
7cca0d81 4112 * Handle the SSH2 userauth and connection layers.
4113 */
4114static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
4115{
65a22376 4116 static enum {
32874aea 4117 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
761187b6 4118 AUTH_PASSWORD,
4119 AUTH_KEYBOARD_INTERACTIVE
65a22376 4120 } method;
1408a877 4121 static enum {
32874aea 4122 AUTH_TYPE_NONE,
4123 AUTH_TYPE_PUBLICKEY,
4124 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4125 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
761187b6 4126 AUTH_TYPE_PASSWORD,
4bdf7c46 4127 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4128 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
1408a877 4129 } type;
761187b6 4130 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4131 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
b3186d64 4132 static int kbd_inter_running;
1408a877 4133 static int we_are_in;
45068b27 4134 static int num_prompts, curr_prompt, echo;
65a22376 4135 static char username[100];
7e9b7f4b 4136 static int got_username;
65a22376 4137 static char pwprompt[200];
4138 static char password[100];
396778f1 4139 static void *publickey_blob;
4140 static int publickey_bloblen;
7cca0d81 4141
e5574168 4142 crBegin;
4143
7cca0d81 4144 /*
4145 * Request userauth protocol, and await a response to it.
4146 */
4147 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4148 ssh2_pkt_addstring("ssh-userauth");
4149 ssh2_pkt_send();
4150 crWaitUntilV(ispkt);
8d5de777 4151 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 4152 bombout(("Server refused user authentication protocol"));
4153 crReturnV;
8d5de777 4154 }
7cca0d81 4155
4156 /*
1408a877 4157 * We repeat this whole loop, including the username prompt,
4158 * until we manage a successful authentication. If the user
4159 * types the wrong _password_, they are sent back to the
4160 * beginning to try another username. (If they specify a
4161 * username in the config, they are never asked, even if they
4162 * do give a wrong password.)
4163 *
4164 * I think this best serves the needs of
4165 *
4166 * - the people who have no configuration, no keys, and just
4167 * want to try repeated (username,password) pairs until they
4168 * type both correctly
4169 *
4170 * - people who have keys and configuration but occasionally
4171 * need to fall back to passwords
4172 *
4173 * - people with a key held in Pageant, who might not have
4174 * logged in to a particular machine before; so they want to
4175 * type a username, and then _either_ their key will be
4176 * accepted, _or_ they will type a password. If they mistype
4177 * the username they will want to be able to get back and
4178 * retype it!
7cca0d81 4179 */
5bb641e1 4180 username[0] = '\0';
7e9b7f4b 4181 got_username = FALSE;
1408a877 4182 do {
1408a877 4183 /*
4184 * Get a username.
4185 */
7e9b7f4b 4186 if (got_username && !cfg.change_username) {
5bb641e1 4187 /*
4188 * We got a username last time round this loop, and
4189 * with change_username turned off we don't try to get
4190 * it again.
4191 */
4192 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 4193 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4194 if (!ssh_get_line("login as: ",
4195 username, sizeof(username), FALSE)) {
4196 /*
4197 * get_line failed to get a username.
4198 * Terminate.
4199 */
4200 logevent("No username provided. Abandoning session.");
4201 ssh_state = SSH_STATE_CLOSED;
4202 crReturnV;
4203 }
4204 } else {
0405e71f 4205 static int ret;
32874aea 4206 c_write_str("login as: ");
4207 ssh_send_ok = 1;
0405e71f 4208 setup_userpass_input(username, sizeof(username), 1);
4209 do {
32874aea 4210 crWaitUntilV(!ispkt);
0405e71f 4211 ret = process_userpass_input(in, inlen);
4212 } while (ret == 0);
4213 if (ret < 0)
4214 cleanup_exit(0);
32874aea 4215 }
1408a877 4216 c_write_str("\r\n");
7cca0d81 4217 username[strcspn(username, "\n\r")] = '\0';
4218 } else {
4219 char stuff[200];
277fc55e 4220 strncpy(username, cfg.username, sizeof(username));
4221 username[sizeof(username)-1] = '\0';
65a22376 4222 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 4223 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 4224 c_write_str(stuff);
7cca0d81 4225 }
4226 }
7e9b7f4b 4227 got_username = TRUE;
7cca0d81 4228
65a22376 4229 /*
1408a877 4230 * Send an authentication request using method "none": (a)
4231 * just in case it succeeds, and (b) so that we know what
4232 * authentication methods we can usefully try next.
65a22376 4233 */
00db133f 4234 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4235
1408a877 4236 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4237 ssh2_pkt_addstring(username);
32874aea 4238 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4239 ssh2_pkt_addstring("none"); /* method */
4240 ssh2_pkt_send();
4241 type = AUTH_TYPE_NONE;
4242 gotit = FALSE;
4243 we_are_in = FALSE;
7cca0d81 4244
1408a877 4245 tried_pubkey_config = FALSE;
1983e559 4246 tried_agent = FALSE;
b3186d64 4247 tried_keyb_inter = FALSE;
4248 kbd_inter_running = FALSE;
396778f1 4249 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4250 if (*cfg.keyfile) {
231ee168 4251 int keytype;
4252 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4253 keytype = key_type(cfg.keyfile);
4254 if (keytype == SSH_KEYTYPE_SSH2)
4255 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4256 &publickey_bloblen);
4257 else {
4258 char msgbuf[256];
4259 logeventf("Unable to use this key file (%s)",
4260 key_type_to_str(keytype));
4261 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4262 cfg.keyfile, key_type_to_str(keytype));
4263 c_write_str(msgbuf);
4264 publickey_blob = NULL;
4265 }
396778f1 4266 } else
4267 publickey_blob = NULL;
65a22376 4268
1408a877 4269 while (1) {
4270 /*
4271 * Wait for the result of the last authentication request.
4272 */
4273 if (!gotit)
4274 crWaitUntilV(ispkt);
4275 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4276 char *banner;
4277 int size;
4278 /*
4279 * Don't show the banner if we're operating in
4280 * non-verbose non-interactive mode. (It's probably
4281 * a script, which means nobody will read the
4282 * banner _anyway_, and moreover the printing of
4283 * the banner will screw up processing on the
4284 * output of (say) plink.)
4285 */
4286 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4287 ssh2_pkt_getstring(&banner, &size);
4288 if (banner)
4289 c_write_untrusted(banner, size);
4290 }
1408a877 4291 crWaitUntilV(ispkt);
4292 }
4293 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4294 logevent("Access granted");
4295 we_are_in = TRUE;
4296 break;
4297 }
65a22376 4298
b3186d64 4299 if (kbd_inter_running &&
4300 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4301 /*
45068b27 4302 * This is either a further set-of-prompts packet
4303 * in keyboard-interactive authentication, or it's
4304 * the same one and we came back here with `gotit'
4305 * set. In the former case, we must reset the
4306 * curr_prompt variable.
b3186d64 4307 */
45068b27 4308 if (!gotit)
4309 curr_prompt = 0;
6bb26b30 4310 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
b3186d64 4311 bombout(("Strange packet received during authentication: type %d",
1408a877 4312 pktin.type));
38c4a8da 4313 crReturnV;
65a22376 4314 }
4315
1408a877 4316 gotit = FALSE;
65a22376 4317
1408a877 4318 /*
4319 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4320 * we can look at the string in it and know what we can
4321 * helpfully try next.
4322 */
b3186d64 4323 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4324 char *methods;
4325 int methlen;
4326 ssh2_pkt_getstring(&methods, &methlen);
b3186d64 4327 kbd_inter_running = FALSE;
1408a877 4328 if (!ssh2_pkt_getbool()) {
4329 /*
4330 * We have received an unequivocal Access
4331 * Denied. This can translate to a variety of
4332 * messages:
4333 *
4334 * - if we'd just tried "none" authentication,
4335 * it's not worth printing anything at all
4336 *
4337 * - if we'd just tried a public key _offer_,
4338 * the message should be "Server refused our
4339 * key" (or no message at all if the key
4340 * came from Pageant)
4341 *
4342 * - if we'd just tried anything else, the
4343 * message really should be "Access denied".
4344 *
4345 * Additionally, if we'd just tried password
4346 * authentication, we should break out of this
4347 * whole loop so as to go back to the username
4348 * prompt.
4349 */
4350 if (type == AUTH_TYPE_NONE) {
4351 /* do nothing */
4352 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4353 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4354 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4355 c_write_str("Server refused our key\r\n");
4356 logevent("Server refused public key");
4bdf7c46 4357 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4358 /* server declined keyboard-interactive; ignore */
1408a877 4359 } else {
4360 c_write_str("Access denied\r\n");
4361 logevent("Access denied");
4362 if (type == AUTH_TYPE_PASSWORD) {
4363 we_are_in = FALSE;
4364 break;
4365 }
4366 }
4367 } else {
4368 c_write_str("Further authentication required\r\n");
4369 logevent("Further authentication required");
4370 }
65a22376 4371
32874aea 4372 can_pubkey =
4373 in_commasep_string("publickey", methods, methlen);
4374 can_passwd =
4375 in_commasep_string("password", methods, methlen);
f091e308 4376 can_keyb_inter = cfg.try_ki_auth &&
761187b6 4377 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4378 }
65a22376 4379
1408a877 4380 method = 0;
00db133f 4381 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4382
0405e71f 4383 /*
4384 * Most password/passphrase prompts will be
4385 * non-echoing, so we set this to 0 by default.
4386 * Exception is that some keyboard-interactive prompts
4387 * can be echoing, in which case we'll set this to 1.
4388 */
4389 echo = 0;
4390
78afa559 4391 if (!method && can_pubkey && agent_exists() && !tried_agent) {
1983e559 4392 /*
4393 * Attempt public-key authentication using Pageant.
4394 */
4395 static unsigned char request[5], *response, *p;
4396 static int responselen;
4397 static int i, nkeys;
4398 static int authed = FALSE;
4399 void *r;
4400
c0a81592 4401 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4402 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4403
1983e559 4404 tried_agent = TRUE;
4405
4406 logevent("Pageant is running. Requesting keys.");
4407
4408 /* Request the keys held by the agent. */
4409 PUT_32BIT(request, 1);
4410 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4411 agent_query(request, 5, &r, &responselen);
32874aea 4412 response = (unsigned char *) r;
95797139 4413 if (response && responselen >= 5 &&
32874aea 4414 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 4415 p = response + 5;
32874aea 4416 nkeys = GET_32BIT(p);
4417 p += 4;
4418 {
4419 char buf[64];
4420 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4421 logevent(buf);
4422 }
1983e559 4423 for (i = 0; i < nkeys; i++) {
4424 static char *pkblob, *alg, *commentp;
4425 static int pklen, alglen, commentlen;
4426 static int siglen, retlen, len;
4427 static char *q, *agentreq, *ret;
2d466ffd 4428 void *vret;
1983e559 4429
32874aea 4430 {
4431 char buf[64];
4432 sprintf(buf, "Trying Pageant key #%d", i);
4433 logevent(buf);
4434 }
4435 pklen = GET_32BIT(p);
4436 p += 4;
396778f1 4437 if (publickey_blob &&
4438 pklen == publickey_bloblen &&
4439 !memcmp(p, publickey_blob, publickey_bloblen)) {
4440 logevent("This key matches configured key file");
4441 tried_pubkey_config = 1;
4442 }
32874aea 4443 pkblob = p;
4444 p += pklen;
1983e559 4445 alglen = GET_32BIT(pkblob);
4446 alg = pkblob + 4;
32874aea 4447 commentlen = GET_32BIT(p);
4448 p += 4;
4449 commentp = p;
4450 p += commentlen;
1983e559 4451 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4452 ssh2_pkt_addstring(username);
32874aea 4453 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4454 ssh2_pkt_addstring("publickey"); /* method */
4455 ssh2_pkt_addbool(FALSE); /* no signature included */
1983e559 4456 ssh2_pkt_addstring_start();
4457 ssh2_pkt_addstring_data(alg, alglen);
4458 ssh2_pkt_addstring_start();
4459 ssh2_pkt_addstring_data(pkblob, pklen);
4460 ssh2_pkt_send();
4461
4462 crWaitUntilV(ispkt);
4463 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4464 logevent("Key refused");
4465 continue;
4466 }
4467
32874aea 4468 if (flags & FLAG_VERBOSE) {
4469 c_write_str
4470 ("Authenticating with public key \"");
4471 c_write(commentp, commentlen);
4472 c_write_str("\" from agent\r\n");
4473 }
1983e559 4474
4475 /*
4476 * Server is willing to accept the key.
4477 * Construct a SIGN_REQUEST.
4478 */
4479 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4480 ssh2_pkt_addstring(username);
32874aea 4481 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4482 ssh2_pkt_addstring("publickey"); /* method */
1983e559 4483 ssh2_pkt_addbool(TRUE);
4484 ssh2_pkt_addstring_start();
4485 ssh2_pkt_addstring_data(alg, alglen);
4486 ssh2_pkt_addstring_start();
4487 ssh2_pkt_addstring_data(pkblob, pklen);
4488
4489 siglen = pktout.length - 5 + 4 + 20;
32874aea 4490 len = 1; /* message type */
4491 len += 4 + pklen; /* key blob */
4492 len += 4 + siglen; /* data to sign */
4493 len += 4; /* flags */
1983e559 4494 agentreq = smalloc(4 + len);
4495 PUT_32BIT(agentreq, len);
4496 q = agentreq + 4;
4497 *q++ = SSH2_AGENTC_SIGN_REQUEST;
32874aea 4498 PUT_32BIT(q, pklen);
4499 q += 4;
4500 memcpy(q, pkblob, pklen);
4501 q += pklen;
4502 PUT_32BIT(q, siglen);
4503 q += 4;
1983e559 4504 /* Now the data to be signed... */
32874aea 4505 PUT_32BIT(q, 20);
4506 q += 4;
4507 memcpy(q, ssh2_session_id, 20);
4508 q += 20;
4509 memcpy(q, pktout.data + 5, pktout.length - 5);
4510 q += pktout.length - 5;
1983e559 4511 /* And finally the (zero) flags word. */
4512 PUT_32BIT(q, 0);
2d466ffd 4513 agent_query(agentreq, len + 4, &vret, &retlen);
4514 ret = vret;
1983e559 4515 sfree(agentreq);
4516 if (ret) {
4517 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4518 logevent("Sending Pageant's response");
1dd353b5 4519 ssh2_add_sigblob(pkblob, pklen,
4520 ret + 9, GET_32BIT(ret + 5));
1983e559 4521 ssh2_pkt_send();
4522 authed = TRUE;
4523 break;
4524 } else {
32874aea 4525 logevent
4526 ("Pageant failed to answer challenge");
1983e559 4527 sfree(ret);
4528 }
4529 }
4530 }
4531 if (authed)
4532 continue;
4533 }
4534 }
4535
231ee168 4536 if (!method && can_pubkey && publickey_blob
32874aea 4537 && !tried_pubkey_config) {
1408a877 4538 unsigned char *pub_blob;
4539 char *algorithm, *comment;
4540 int pub_blob_len;
65a22376 4541
1408a877 4542 tried_pubkey_config = TRUE;
65a22376 4543
c0a81592 4544 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4545 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4546
65a22376 4547 /*
1408a877 4548 * Try the public key supplied in the configuration.
4549 *
4550 * First, offer the public blob to see if the server is
4551 * willing to accept it.
65a22376 4552 */
1408a877 4553 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4554 &pub_blob_len);
4555 if (pub_blob) {
4556 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4557 ssh2_pkt_addstring(username);
32874aea 4558 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4559 ssh2_pkt_addstring("publickey"); /* method */
4560 ssh2_pkt_addbool(FALSE); /* no signature included */
1408a877 4561 ssh2_pkt_addstring(algorithm);
4562 ssh2_pkt_addstring_start();
4563 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4564 ssh2_pkt_send();
32874aea 4565 logevent("Offered public key"); /* FIXME */
1408a877 4566
4567 crWaitUntilV(ispkt);
4568 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4569 gotit = TRUE;
4570 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4571 continue; /* key refused; give up on it */
1408a877 4572 }
65a22376 4573
1408a877 4574 logevent("Offer of public key accepted");
65a22376 4575 /*
1408a877 4576 * Actually attempt a serious authentication using
4577 * the key.
65a22376 4578 */
1408a877 4579 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
32874aea 4580 sprintf(pwprompt,
4581 "Passphrase for key \"%.100s\": ",
4582 comment);
1408a877 4583 need_pw = TRUE;
4584 } else {
4585 need_pw = FALSE;
4586 }
4587 c_write_str("Authenticating with public key \"");
4588 c_write_str(comment);
4589 c_write_str("\"\r\n");
4590 method = AUTH_PUBLICKEY_FILE;
65a22376 4591 }
1408a877 4592 }
4593
af659722 4594 if (!method && can_keyb_inter && !tried_keyb_inter) {
4595 method = AUTH_KEYBOARD_INTERACTIVE;
4596 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4597 tried_keyb_inter = TRUE;
4598
c0a81592 4599 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4600 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4601
af659722 4602 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4603 ssh2_pkt_addstring(username);
4604 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4605 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4606 ssh2_pkt_addstring(""); /* lang */
4607 ssh2_pkt_addstring("");
4608 ssh2_pkt_send();
4609
4610 crWaitUntilV(ispkt);
4611 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4612 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4613 gotit = TRUE;
4614 logevent("Keyboard-interactive authentication refused");
4615 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4616 continue;
4617 }
4618
4619 kbd_inter_running = TRUE;
45068b27 4620 curr_prompt = 0;
af659722 4621 }
4622
4623 if (kbd_inter_running) {
4624 method = AUTH_KEYBOARD_INTERACTIVE;
4625 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4626 tried_keyb_inter = TRUE;
4627
c0a81592 4628 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4629 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4630
45068b27 4631 if (curr_prompt == 0) {
4632 /*
4633 * We've got a fresh USERAUTH_INFO_REQUEST.
4634 * Display header data, and start going through
4635 * the prompts.
4636 */
4637 char *name, *inst, *lang;
4638 int name_len, inst_len, lang_len;
4639
af659722 4640 ssh2_pkt_getstring(&name, &name_len);
4641 ssh2_pkt_getstring(&inst, &inst_len);
4642 ssh2_pkt_getstring(&lang, &lang_len);
45068b27 4643 if (name_len > 0) {
af659722 4644 c_write_untrusted(name, name_len);
0405e71f 4645 c_write_str("\r\n");
45068b27 4646 }
4647 if (inst_len > 0) {
af659722 4648 c_write_untrusted(inst, inst_len);
0405e71f 4649 c_write_str("\r\n");
45068b27 4650 }
af659722 4651 num_prompts = ssh2_pkt_getuint32();
45068b27 4652 }
af659722 4653
45068b27 4654 /*
4655 * If there are prompts remaining in the packet,
4656 * display one and get a response.
4657 */
4658 if (curr_prompt < num_prompts) {
4659 char *prompt;
4660 int prompt_len;
af659722 4661
45068b27 4662 ssh2_pkt_getstring(&prompt, &prompt_len);
4663 if (prompt_len > 0) {
4664 strncpy(pwprompt, prompt, sizeof(pwprompt));
4665 pwprompt[prompt_len < sizeof(pwprompt) ?
4666 prompt_len : sizeof(pwprompt)-1] = '\0';
4667 } else {
4668 strcpy(pwprompt,
4669 "<server failed to send prompt>: ");
4670 }
af659722 4671 echo = ssh2_pkt_getbool();
45068b27 4672 need_pw = TRUE;
4673 } else
4674 need_pw = FALSE;
af659722 4675 }
4676
1408a877 4677 if (!method && can_passwd) {
4678 method = AUTH_PASSWORD;
c0a81592 4679 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4680 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
32874aea 4681 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4682 savedhost);
1408a877 4683 need_pw = TRUE;
4684 }
4685
4686 if (need_pw) {
fa17a66e 4687 if (ssh_get_line) {
4688 if (!ssh_get_line(pwprompt, password,
32874aea 4689 sizeof(password), TRUE)) {
1408a877 4690 /*
fa17a66e 4691 * get_line failed to get a password (for
4692 * example because one was supplied on the
4693 * command line which has already failed to
4694 * work). Terminate.
1408a877 4695 */
2bc6a386 4696 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4697 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4698 ssh2_pkt_addstring
4699 ("No more passwords available to try");
4700 ssh2_pkt_addstring("en"); /* language tag */
4701 ssh2_pkt_send();
247308b5 4702 logevent("Unable to authenticate");
2bc6a386 4703 connection_fatal("Unable to authenticate");
1408a877 4704 ssh_state = SSH_STATE_CLOSED;
4705 crReturnV;
4706 }
4707 } else {
0405e71f 4708 static int ret;
761187b6 4709 c_write_untrusted(pwprompt, strlen(pwprompt));
1408a877 4710 ssh_send_ok = 1;
4711
0405e71f 4712 setup_userpass_input(password, sizeof(password), echo);
4713 do {
1408a877 4714 crWaitUntilV(!ispkt);
0405e71f 4715 ret = process_userpass_input(in, inlen);
4716 } while (ret == 0);
4717 if (ret < 0)
4718 cleanup_exit(0);
1408a877 4719 c_write_str("\r\n");
65a22376 4720 }
65a22376 4721 }
65a22376 4722
1408a877 4723 if (method == AUTH_PUBLICKEY_FILE) {
4724 /*
4725 * We have our passphrase. Now try the actual authentication.
4726 */
4727 struct ssh2_userkey *key;
65a22376 4728
1408a877 4729 key = ssh2_load_userkey(cfg.keyfile, password);
4730 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4731 if (key == SSH2_WRONG_PASSPHRASE) {
4732 c_write_str("Wrong passphrase\r\n");
4733 tried_pubkey_config = FALSE;
4734 } else {
4735 c_write_str("Unable to load private key\r\n");
4736 tried_pubkey_config = TRUE;
4737 }
4738 /* Send a spurious AUTH_NONE to return to the top. */
4739 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4740 ssh2_pkt_addstring(username);
32874aea 4741 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4742 ssh2_pkt_addstring("none"); /* method */
1408a877 4743 ssh2_pkt_send();
4744 type = AUTH_TYPE_NONE;
4745 } else {
1dd353b5 4746 unsigned char *pkblob, *sigblob, *sigdata;
4747 int pkblob_len, sigblob_len, sigdata_len;
65a22376 4748
1408a877 4749 /*
4750 * We have loaded the private key and the server
4751 * has announced that it's willing to accept it.
4752 * Hallelujah. Generate a signature and send it.
4753 */
4754 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4755 ssh2_pkt_addstring(username);
32874aea 4756 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4757 ssh2_pkt_addstring("publickey"); /* method */
1408a877 4758 ssh2_pkt_addbool(TRUE);
4759 ssh2_pkt_addstring(key->alg->name);
1dd353b5 4760 pkblob = key->alg->public_blob(key->data, &pkblob_len);
1408a877 4761 ssh2_pkt_addstring_start();
1dd353b5 4762 ssh2_pkt_addstring_data(pkblob, pkblob_len);
1408a877 4763
4764 /*
4765 * The data to be signed is:
4766 *
4767 * string session-id
4768 *
4769 * followed by everything so far placed in the
4770 * outgoing packet.
4771 */
4772 sigdata_len = pktout.length - 5 + 4 + 20;
4773 sigdata = smalloc(sigdata_len);
4774 PUT_32BIT(sigdata, 20);
32874aea 4775 memcpy(sigdata + 4, ssh2_session_id, 20);
4776 memcpy(sigdata + 24, pktout.data + 5,
4777 pktout.length - 5);
1dd353b5 4778 sigblob = key->alg->sign(key->data, sigdata,
4779 sigdata_len, &sigblob_len);
4780 ssh2_add_sigblob(pkblob, pkblob_len,
4781 sigblob, sigblob_len);
4782 sfree(pkblob);
4783 sfree(sigblob);
1408a877 4784 sfree(sigdata);
4785
4786 ssh2_pkt_send();
4787 type = AUTH_TYPE_PUBLICKEY;
4788 }
4789 } else if (method == AUTH_PASSWORD) {
65a22376 4790 /*
1408a877 4791 * We send the password packet lumped tightly together with
4792 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4793 * string long enough to make the total length of the two
4794 * packets constant. This should ensure that a passive
4795 * listener doing traffic analyis can't work out the length
4796 * of the password.
4797 *
4798 * For this to work, we need an assumption about the
4799 * maximum length of the password packet. I think 256 is
4800 * pretty conservative. Anyone using a password longer than
4801 * that probably doesn't have much to worry about from
4802 * people who find out how long their password is!
65a22376 4803 */
4804 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4805 ssh2_pkt_addstring(username);
32874aea 4806 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4807 ssh2_pkt_addstring("password");
4808 ssh2_pkt_addbool(FALSE);
4809 ssh2_pkt_addstring(password);
4810 ssh2_pkt_defer();
65a22376 4811 /*
1408a877 4812 * We'll include a string that's an exact multiple of the
4813 * cipher block size. If the cipher is NULL for some
4814 * reason, we don't do this trick at all because we gain
4815 * nothing by it.
65a22376 4816 */
32874aea 4817 if (cscipher) {
4818 int stringlen, i;
4819
4820 stringlen = (256 - deferred_len);
4821 stringlen += cscipher->blksize - 1;
4822 stringlen -= (stringlen % cscipher->blksize);
4823 if (cscomp) {
4824 /*
4825 * Temporarily disable actual compression,
4826 * so we can guarantee to get this string
4827 * exactly the length we want it. The
4828 * compression-disabling routine should
4829 * return an integer indicating how many
4830 * bytes we should adjust our string length
4831 * by.
4832 */
4833 stringlen -= cscomp->disable_compression();
4834 }
1408a877 4835 ssh2_pkt_init(SSH2_MSG_IGNORE);
4836 ssh2_pkt_addstring_start();
6e9e9520 4837 for (i = 0; i < stringlen; i++) {
32874aea 4838 char c = (char) random_byte();
4839 ssh2_pkt_addstring_data(&c, 1);
65a22376 4840 }
1408a877 4841 ssh2_pkt_defer();
65a22376 4842 }
39065bed 4843 ssh_pkt_defersend();
0d43337a 4844 logevent("Sent password");
1408a877 4845 type = AUTH_TYPE_PASSWORD;
761187b6 4846 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
45068b27 4847 if (curr_prompt == 0) {
4848 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4849 ssh2_pkt_adduint32(num_prompts);
4850 }
4851 if (need_pw) { /* only add pw if we just got one! */
4852 ssh2_pkt_addstring(password);
4853 memset(password, 0, sizeof(password));
4854 curr_prompt++;
4855 }
4856 if (curr_prompt >= num_prompts) {
4857 ssh2_pkt_send();
4858 } else {
4859 /*
4860 * If there are prompts remaining, we set
4861 * `gotit' so that we won't attempt to get
4862 * another packet. Then we go back round the
4863 * loop and will end up retrieving another
4864 * prompt out of the existing packet. Funky or
4865 * what?
4866 */
4867 gotit = TRUE;
4868 }
761187b6 4869 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 4870 } else {
32874aea 4871 c_write_str
4872 ("No supported authentication methods left to try!\r\n");
4873 logevent
4874 ("No supported authentications offered. Disconnecting");
1408a877 4875 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4876 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
32874aea 4877 ssh2_pkt_addstring
4878 ("No supported authentication methods available");
4879 ssh2_pkt_addstring("en"); /* language tag */
1408a877 4880 ssh2_pkt_send();
4881 ssh_state = SSH_STATE_CLOSED;
4882 crReturnV;
65a22376 4883 }
65a22376 4884 }
1408a877 4885 } while (!we_are_in);
7cca0d81 4886
4887 /*
4888 * Now we're authenticated for the connection protocol. The
4889 * connection protocol will automatically have started at this
4890 * point; there's no need to send SERVICE_REQUEST.
4891 */
4892
4893 /*
4894 * So now create a channel with a session in it.
4895 */
d2371c81 4896 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 4897 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 4898 mainchan->localid = alloc_channel_id();
7cca0d81 4899 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4900 ssh2_pkt_addstring("session");
d211621f 4901 ssh2_pkt_adduint32(mainchan->localid);
5471d09a 4902 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4903 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
32874aea 4904 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 4905 ssh2_pkt_send();
4906 crWaitUntilV(ispkt);
4907 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 4908 bombout(("Server refused to open a session"));
4909 crReturnV;
4910 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 4911 }
d211621f 4912 if (ssh2_pkt_getuint32() != mainchan->localid) {
32874aea 4913 bombout(("Server's channel confirmation cited wrong channel"));
4914 crReturnV;
7cca0d81 4915 }
d211621f 4916 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 4917 mainchan->type = CHAN_MAINSESSION;
4918 mainchan->closes = 0;
5471d09a 4919 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4920 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4921 bufchain_init(&mainchan->v.v2.outbuffer);
783415f8 4922 add234(ssh_channels, mainchan);
7cca0d81 4923 logevent("Opened channel for session");
4924
4925 /*
783415f8 4926 * Potentially enable X11 forwarding.
4927 */
4928 if (cfg.x11_forward) {
32874aea 4929 char proto[20], data[64];
4930 logevent("Requesting X11 forwarding");
4931 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4932 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4933 ssh2_pkt_adduint32(mainchan->remoteid);
4934 ssh2_pkt_addstring("x11-req");
4935 ssh2_pkt_addbool(1); /* want reply */
4936 ssh2_pkt_addbool(0); /* many connections */
4937 ssh2_pkt_addstring(proto);
4938 ssh2_pkt_addstring(data);
4939 ssh2_pkt_adduint32(0); /* screen number */
4940 ssh2_pkt_send();
4941
4942 do {
4943 crWaitUntilV(ispkt);
4944 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4945 unsigned i = ssh2_pkt_getuint32();
4946 struct ssh_channel *c;
4947 c = find234(ssh_channels, &i, ssh_channelfind);
4948 if (!c)
4949 continue; /* nonexistent channel */
5471d09a 4950 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4951 }
4952 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4953
4954 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4955 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4956 bombout(("Unexpected response to X11 forwarding request:"
4957 " packet type %d", pktin.type));
32874aea 4958 crReturnV;
4959 }
4960 logevent("X11 forwarding refused");
4961 } else {
4962 logevent("X11 forwarding enabled");
783415f8 4963 ssh_X11_fwd_enabled = TRUE;
32874aea 4964 }
783415f8 4965 }
4966
4967 /*
bc240b21 4968 * Enable port forwardings.
4969 */
4970 {
4971 static char *e; /* preserve across crReturn */
4972 char type;
4973 int n;
a4fc0d74 4974 int sport,dport,sserv,dserv;
bc240b21 4975 char sports[256], dports[256], host[256];
4976 char buf[1024];
a4fc0d74 4977 struct servent *se;
bc240b21 4978
4979 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4980 /* Add port forwardings. */
4981 e = cfg.portfwd;
4982 while (*e) {
4983 type = *e++;
4984 n = 0;
4985 while (*e && *e != '\t')
4986 sports[n++] = *e++;
4987 sports[n] = 0;
4988 if (*e == '\t')
4989 e++;
4990 n = 0;
4991 while (*e && *e != ':')
4992 host[n++] = *e++;
4993 host[n] = 0;
4994 if (*e == ':')
4995 e++;
4996 n = 0;
4997 while (*e)
4998 dports[n++] = *e++;
4999 dports[n] = 0;
5000 e++;
5001 dport = atoi(dports);
a4fc0d74 5002 dserv = 0;
5003 if (dport == 0) {
5004 dserv = 1;
5005 se = getservbyname(dports, NULL);
5006 if (se != NULL) {
5007 dport = ntohs(se->s_port);
5008 } else {
5009 sprintf(buf,
5010 "Service lookup failed for destination port \"%s\"",
5011 dports);
5012 logevent(buf);
5013 }
5014 }
bc240b21 5015 sport = atoi(sports);
a4fc0d74 5016 sserv = 0;
5017 if (sport == 0) {
5018 sserv = 1;
5019 se = getservbyname(sports, NULL);
5020 if (se != NULL) {
5021 sport = ntohs(se->s_port);
5022 } else {
5023 sprintf(buf,
5024 "Service lookup failed for source port \"%s\"",
5025 sports);
5026 logevent(buf);
5027 }
5028 }
bc240b21 5029 if (sport && dport) {
5030 if (type == 'L') {
5031 pfd_addforward(host, dport, sport);
a4fc0d74 5032 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
5033 " %s:%.*s%.*s%d%.*s",
5034 sserv ? strlen(sports) : 0, sports,
5035 sserv, "(", sport, sserv, ")",
5036 host,
5037 dserv ? strlen(dports) : 0, dports,
5038 dserv, "(", dport, dserv, ")");
bc240b21 5039 logevent(buf);
5040 } else {
5041 struct ssh_rportfwd *pf;
5042 pf = smalloc(sizeof(*pf));
5043 strcpy(pf->dhost, host);
5044 pf->dport = dport;
5045 pf->sport = sport;
5046 if (add234(ssh_rportfwds, pf) != pf) {
5047 sprintf(buf,
95bc8819 5048 "Duplicate remote port forwarding to %s:%d",
bc240b21 5049 host, dport);
5050 logevent(buf);
5051 sfree(pf);
5052 } else {
a4fc0d74 5053 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5054 " forward to %s:%.*s%.*s%d%.*s",
5055 sserv ? strlen(sports) : 0, sports,
5056 sserv, "(", sport, sserv, ")",
5057 host,
5058 dserv ? strlen(dports) : 0, dports,
5059 dserv, "(", dport, dserv, ")");
bc240b21 5060 logevent(buf);
5061 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5062 ssh2_pkt_addstring("tcpip-forward");
5063 ssh2_pkt_addbool(1);/* want reply */
beefa433 5064 if (cfg.rport_acceptall)
5065 ssh2_pkt_addstring("0.0.0.0");
5066 else
5067 ssh2_pkt_addstring("127.0.0.1");
bc240b21 5068 ssh2_pkt_adduint32(sport);
5069 ssh2_pkt_send();
5070
5071 do {
5072 crWaitUntilV(ispkt);
5073 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5074 unsigned i = ssh2_pkt_getuint32();
5075 struct ssh_channel *c;
5076 c = find234(ssh_channels, &i, ssh_channelfind);
5077 if (!c)
5078 continue;/* nonexistent channel */
5471d09a 5079 c->v.v2.remwindow += ssh2_pkt_getuint32();
bc240b21 5080 }
5081 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5082
5083 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5084 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
c9886e66 5085 bombout(("Unexpected response to port "
5086 "forwarding request: packet type %d",
5087 pktin.type));
bc240b21 5088 crReturnV;
5089 }
5090 logevent("Server refused this port forwarding");
5091 } else {
5092 logevent("Remote port forwarding enabled");
5093 }
5094 }
5095 }
5096 }
5097 }
5098 }
5099
5100 /*
36c2a3e9 5101 * Potentially enable agent forwarding.
5102 */
5103 if (cfg.agentfwd && agent_exists()) {
32874aea 5104 logevent("Requesting OpenSSH-style agent forwarding");
5105 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5106 ssh2_pkt_adduint32(mainchan->remoteid);
5107 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5108 ssh2_pkt_addbool(1); /* want reply */
5109 ssh2_pkt_send();
5110
5111 do {
5112 crWaitUntilV(ispkt);
5113 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5114 unsigned i = ssh2_pkt_getuint32();
5115 struct ssh_channel *c;
5116 c = find234(ssh_channels, &i, ssh_channelfind);
5117 if (!c)
5118 continue; /* nonexistent channel */
5471d09a 5119 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5120 }
5121 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5122
5123 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5124 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5125 bombout(("Unexpected response to agent forwarding request:"
5126 " packet type %d", pktin.type));
32874aea 5127 crReturnV;
5128 }
5129 logevent("Agent forwarding refused");
5130 } else {
5131 logevent("Agent forwarding enabled");
36c2a3e9 5132 ssh_agentfwd_enabled = TRUE;
32874aea 5133 }
36c2a3e9 5134 }
5135
5136 /*
7cca0d81 5137 * Now allocate a pty for the session.
5138 */
67779be7 5139 if (!cfg.nopty) {
32874aea 5140 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5141 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5142 ssh2_pkt_addstring("pty-req");
5143 ssh2_pkt_addbool(1); /* want reply */
5144 ssh2_pkt_addstring(cfg.termtype);
5145 ssh2_pkt_adduint32(cols);
5146 ssh2_pkt_adduint32(rows);
5147 ssh2_pkt_adduint32(0); /* pixel width */
5148 ssh2_pkt_adduint32(0); /* pixel height */
5149 ssh2_pkt_addstring_start();
5150 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5151 ssh2_pkt_send();
5152 ssh_state = SSH_STATE_INTERMED;
5153
5154 do {
5155 crWaitUntilV(ispkt);
5156 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5157 unsigned i = ssh2_pkt_getuint32();
5158 struct ssh_channel *c;
5159 c = find234(ssh_channels, &i, ssh_channelfind);
5160 if (!c)
5161 continue; /* nonexistent channel */
5471d09a 5162 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5163 }
5164 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5165
5166 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5167 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5168 bombout(("Unexpected response to pty request:"
5169 " packet type %d", pktin.type));
32874aea 5170 crReturnV;
5171 }
5172 c_write_str("Server refused to allocate pty\r\n");
5173 ssh_editing = ssh_echoing = 1;
5174 } else {
5175 logevent("Allocated pty");
5176 }
0965bee0 5177 } else {
32874aea 5178 ssh_editing = ssh_echoing = 1;
7cca0d81 5179 }
5180
5181 /*
fd5e5847 5182 * Start a shell or a remote command. We may have to attempt
5183 * this twice if the config data has provided a second choice
5184 * of command.
7cca0d81 5185 */
fd5e5847 5186 while (1) {
5187 int subsys;
5188 char *cmd;
5189
5190 if (ssh_fallback_cmd) {
5191 subsys = cfg.ssh_subsys2;
5192 cmd = cfg.remote_cmd_ptr2;
5193 } else {
5194 subsys = cfg.ssh_subsys;
5195 cmd = cfg.remote_cmd_ptr;
5196 }
5197
5198 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5199 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5200 if (subsys) {
5201 ssh2_pkt_addstring("subsystem");
5202 ssh2_pkt_addbool(1); /* want reply */
5203 ssh2_pkt_addstring(cmd);
5204 } else if (*cmd) {
5205 ssh2_pkt_addstring("exec");
5206 ssh2_pkt_addbool(1); /* want reply */
5207 ssh2_pkt_addstring(cmd);
5208 } else {
5209 ssh2_pkt_addstring("shell");
5210 ssh2_pkt_addbool(1); /* want reply */
32874aea 5211 }
fd5e5847 5212 ssh2_pkt_send();
5213 do {
5214 crWaitUntilV(ispkt);
5215 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5216 unsigned i = ssh2_pkt_getuint32();
5217 struct ssh_channel *c;
5218 c = find234(ssh_channels, &i, ssh_channelfind);
5219 if (!c)
5220 continue; /* nonexistent channel */
5221 c->v.v2.remwindow += ssh2_pkt_getuint32();
5222 }
5223 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5224 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5225 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5226 bombout(("Unexpected response to shell/command request:"
5227 " packet type %d", pktin.type));
fd5e5847 5228 crReturnV;
5229 }
5230 /*
5231 * We failed to start the command. If this is the
5232 * fallback command, we really are finished; if it's
5233 * not, and if the fallback command exists, try falling
5234 * back to it before complaining.
5235 */
5236 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5237 logevent("Primary command failed; attempting fallback");
5238 ssh_fallback_cmd = TRUE;
5239 continue;
5240 }
5241 bombout(("Server refused to start a shell/command"));
32874aea 5242 crReturnV;
fd5e5847 5243 } else {
5244 logevent("Started a shell/command");
32874aea 5245 }
fd5e5847 5246 break;
7cca0d81 5247 }
5248
6e48c3fe 5249 ssh_state = SSH_STATE_SESSION;
5250 if (size_needed)
5251 ssh_size();
3687d221 5252 if (eof_needed)
32874aea 5253 ssh_special(TS_EOF);
6e48c3fe 5254
7cca0d81 5255 /*
5256 * Transfer data!
5257 */
760e88b2 5258 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 5259 ssh_send_ok = 1;
7cca0d81 5260 while (1) {
32874aea 5261 static int try_send;
e5574168 5262 crReturnV;
32874aea 5263 try_send = FALSE;
7cca0d81 5264 if (ispkt) {
5265 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
32874aea 5266 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5267 char *data;
5268 int length;
5269 unsigned i = ssh2_pkt_getuint32();
5270 struct ssh_channel *c;
5271 c = find234(ssh_channels, &i, ssh_channelfind);
5272 if (!c)
5273 continue; /* nonexistent channel */
5274 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5275 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5276 continue; /* extended but not stderr */
5277 ssh2_pkt_getstring(&data, &length);
5278 if (data) {
5471d09a 5279 int bufsize;
5280 c->v.v2.locwindow -= length;
32874aea 5281 switch (c->type) {
5282 case CHAN_MAINSESSION:
5471d09a 5283 bufsize =
5284 from_backend(pktin.type ==
5285 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5286 data, length);
32874aea 5287 break;
5288 case CHAN_X11:
5471d09a 5289 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5290 break;
d74d141c 5291 case CHAN_SOCKDATA:
5471d09a 5292 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5293 break;
36c2a3e9 5294 case CHAN_AGENT:
32874aea 5295 while (length > 0) {
5296 if (c->u.a.lensofar < 4) {
5297 int l = min(4 - c->u.a.lensofar, length);
5298 memcpy(c->u.a.msglen + c->u.a.lensofar,
5299 data, l);
5300 data += l;
5301 length -= l;
5302 c->u.a.lensofar += l;
5303 }
5304 if (c->u.a.lensofar == 4) {
5305 c->u.a.totallen =
5306 4 + GET_32BIT(c->u.a.msglen);
5307 c->u.a.message = smalloc(c->u.a.totallen);
5308 memcpy(c->u.a.message, c->u.a.msglen, 4);
5309 }
5310 if (c->u.a.lensofar >= 4 && length > 0) {
5311 int l =
5312 min(c->u.a.totallen - c->u.a.lensofar,
5313 length);
5314 memcpy(c->u.a.message + c->u.a.lensofar,
5315 data, l);
5316 data += l;
5317 length -= l;
5318 c->u.a.lensofar += l;
5319 }
5320 if (c->u.a.lensofar == c->u.a.totallen) {
5321 void *reply, *sentreply;
5322 int replylen;
5323 agent_query(c->u.a.message,
5324 c->u.a.totallen, &reply,
5325 &replylen);
5326 if (reply)
5327 sentreply = reply;
5328 else {
5329 /* Fake SSH_AGENT_FAILURE. */
5330 sentreply = "\0\0\0\1\5";
5331 replylen = 5;
5332 }
5333 ssh2_add_channel_data(c, sentreply,
5334 replylen);
36c2a3e9 5335 try_send = TRUE;
32874aea 5336 if (reply)
5337 sfree(reply);
5338 sfree(c->u.a.message);
5339 c->u.a.lensofar = 0;
5340 }
5341 }
5471d09a 5342 bufsize = 0;
32874aea 5343 break;
5344 }
5345 /*
5471d09a 5346 * If we are not buffering too much data,
5347 * enlarge the window again at the remote side.
32874aea 5348 */
5471d09a 5349 if (bufsize < OUR_V2_WINSIZE)
5350 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5351 }
7cca0d81 5352 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
32874aea 5353 ssh_state = SSH_STATE_CLOSED;
d211621f 5354 logevent("Received disconnect message");
32874aea 5355 crReturnV;
d211621f 5356 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
32874aea 5357 unsigned i = ssh2_pkt_getuint32();
5358 struct ssh_channel *c;
5359
5360 c = find234(ssh_channels, &i, ssh_channelfind);
5361 if (!c)
5362 continue; /* nonexistent channel */
5363
5364 if (c->type == CHAN_X11) {
5365 /*
5366 * Remote EOF on an X11 channel means we should
5367 * wrap up and close the channel ourselves.
5368 */
5369 x11_close(c->u.x11.s);
5370 sshfwd_close(c);
5371 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5372 sshfwd_close(c);
d74d141c 5373 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5374 pfd_close(c->u.pfd.s);
5375 sshfwd_close(c);
36c2a3e9 5376 }
d211621f 5377 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
32874aea 5378 unsigned i = ssh2_pkt_getuint32();
5379 struct ssh_channel *c;
5380
5381 c = find234(ssh_channels, &i, ssh_channelfind);
d0d844c1 5382 if (!c || ((int)c->remoteid) == -1) {
5383 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5384 c ? "half-open" : "nonexistent", i));
5385 }
32874aea 5386 /* Do pre-close processing on the channel. */
5387 switch (c->type) {
5388 case CHAN_MAINSESSION:
5389 break; /* nothing to see here, move along */
5390 case CHAN_X11:
92f157bd 5391 if (c->u.x11.s != NULL)
5392 x11_close(c->u.x11.s);
5393 sshfwd_close(c);
32874aea 5394 break;
5395 case CHAN_AGENT:
92f157bd 5396 sshfwd_close(c);
32874aea 5397 break;
d74d141c 5398 case CHAN_SOCKDATA:
92f157bd 5399 if (c->u.pfd.s != NULL)
5400 pfd_close(c->u.pfd.s);
5401 sshfwd_close(c);
bc240b21 5402 break;
32874aea 5403 }
92f157bd 5404 if (c->closes == 0) {
5405 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5406 ssh2_pkt_adduint32(c->remoteid);
5407 ssh2_pkt_send();
5408 }
32874aea 5409 del234(ssh_channels, c);
5471d09a 5410 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5411 sfree(c);
5412
5413 /*
5414 * See if that was the last channel left open.
5415 */
5416 if (count234(ssh_channels) == 0) {
ca2914d1 5417#if 0
5418 /*
5419 * We used to send SSH_MSG_DISCONNECT here,
5420 * because I'd believed that _every_ conforming
5421 * SSH2 connection had to end with a disconnect
5422 * being sent by at least one side; apparently
5423 * I was wrong and it's perfectly OK to
5424 * unceremoniously slam the connection shut
5425 * when you're done, and indeed OpenSSH feels
5426 * this is more polite than sending a
5427 * DISCONNECT. So now we don't.
5428 */
32874aea 5429 logevent("All channels closed. Disconnecting");
5430 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5431 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5432 ssh2_pkt_addstring("All open channels closed");
5433 ssh2_pkt_addstring("en"); /* language tag */
5434 ssh2_pkt_send();
ca2914d1 5435#endif
32874aea 5436 ssh_state = SSH_STATE_CLOSED;
5437 crReturnV;
5438 }
5439 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 5440 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
32874aea 5441 unsigned i = ssh2_pkt_getuint32();
5442 struct ssh_channel *c;
5443 c = find234(ssh_channels, &i, ssh_channelfind);
5444 if (!c)
5445 continue; /* nonexistent channel */
5471d09a 5446 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5447 try_send = TRUE;
bc240b21 5448 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5449 unsigned i = ssh2_pkt_getuint32();
5450 struct ssh_channel *c;
5451 c = find234(ssh_channels, &i, ssh_channelfind);
5452 if (!c)
5453 continue; /* nonexistent channel */
5454 if (c->type != CHAN_SOCKDATA_DORMANT)
5455 continue; /* dunno why they're confirming this */
5456 c->remoteid = ssh2_pkt_getuint32();
5457 c->type = CHAN_SOCKDATA;
5471d09a 5458 c->v.v2.remwindow = ssh2_pkt_getuint32();
5459 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4ed34d25 5460 if (c->u.pfd.s)
5461 pfd_confirm(c->u.pfd.s);
5462 if (c->closes) {
5463 /*
5464 * We have a pending close on this channel,
5465 * which we decided on before the server acked
5466 * the channel open. So now we know the
5467 * remoteid, we can close it again.
5468 */
5469 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5470 ssh2_pkt_adduint32(c->remoteid);
5471 ssh2_pkt_send();
5472 }
724cface 5473 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5474 unsigned i = ssh2_pkt_getuint32();
5475 struct ssh_channel *c;
5476 c = find234(ssh_channels, &i, ssh_channelfind);
5477 if (!c)
5478 continue; /* nonexistent channel */
5479 if (c->type != CHAN_SOCKDATA_DORMANT)
5480 continue; /* dunno why they're failing this */
5481
5482 logevent("Forwarded connection refused by server");
5483
5484 pfd_close(c->u.pfd.s);
5485
5486 del234(ssh_channels, c);
5487 sfree(c);
ebb0a590 5488 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5489 unsigned localid;
5490 char *type;
5491 int typelen, want_reply;
5492 struct ssh_channel *c;
5493
5494 localid = ssh2_pkt_getuint32();
5495 ssh2_pkt_getstring(&type, &typelen);
5496 want_reply = ssh2_pkt_getbool();
5497
5498 /*
5499 * First, check that the channel exists. Otherwise,
5500 * we can instantly disconnect with a rude message.
5501 */
5502 c = find234(ssh_channels, &localid, ssh_channelfind);
5503 if (!c) {
5504 char buf[80];
5505 sprintf(buf, "Received channel request for nonexistent"
5506 " channel %d", localid);
5507 logevent(buf);
5508 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5509 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5510 ssh2_pkt_addstring(buf);
5511 ssh2_pkt_addstring("en"); /* language tag */
5512 ssh2_pkt_send();
247308b5 5513 connection_fatal("%s", buf);
ebb0a590 5514 ssh_state = SSH_STATE_CLOSED;
5515 crReturnV;
5516 }
5517
5518 /*
d8d6c7e5 5519 * Having got the channel number, we now look at
5520 * the request type string to see if it's something
5521 * we recognise.
ebb0a590 5522 */
d8d6c7e5 5523 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5524 c == mainchan) {
5525 /* We recognise "exit-status" on the primary channel. */
5526 char buf[100];
5527 ssh_exitcode = ssh2_pkt_getuint32();
5528 sprintf(buf, "Server sent command exit status %d",
5529 ssh_exitcode);
5530 logevent(buf);
5531 if (want_reply) {
5532 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5533 ssh2_pkt_adduint32(c->remoteid);
5534 ssh2_pkt_send();
5535 }
5536 } else {
5537 /*
5538 * This is a channel request we don't know
5539 * about, so we now either ignore the request
5540 * or respond with CHANNEL_FAILURE, depending
5541 * on want_reply.
5542 */
5543 if (want_reply) {
5544 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5545 ssh2_pkt_adduint32(c->remoteid);
5546 ssh2_pkt_send();
5547 }
ebb0a590 5548 }
697d4856 5549 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5550 char *type;
5551 int typelen, want_reply;
5552
5553 ssh2_pkt_getstring(&type, &typelen);
5554 want_reply = ssh2_pkt_getbool();
5555
5556 /*
5557 * We currently don't support any global requests
5558 * at all, so we either ignore the request or
5559 * respond with REQUEST_FAILURE, depending on
5560 * want_reply.
5561 */
5562 if (want_reply) {
5563 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5564 ssh2_pkt_send();
5565 }
783415f8 5566 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5567 char *type;
5568 int typelen;
5569 char *error = NULL;
5570 struct ssh_channel *c;
bc240b21 5571 unsigned remid, winsize, pktsize;
32874aea 5572 ssh2_pkt_getstring(&type, &typelen);
5573 c = smalloc(sizeof(struct ssh_channel));
5574
bc240b21 5575 remid = ssh2_pkt_getuint32();
5576 winsize = ssh2_pkt_getuint32();
5577 pktsize = ssh2_pkt_getuint32();
5578
32874aea 5579 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5580 if (!ssh_X11_fwd_enabled)
5581 error = "X11 forwarding is not enabled";
5582 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5583 NULL) {
5584 error = "Unable to open an X11 connection";
5585 } else {
5586 c->type = CHAN_X11;
5587 }
bc240b21 5588 } else if (typelen == 15 &&
5589 !memcmp(type, "forwarded-tcpip", 15)) {
5590 struct ssh_rportfwd pf, *realpf;
5591 char *dummy;
5592 int dummylen;
5593 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5594 pf.sport = ssh2_pkt_getuint32();
5595 realpf = find234(ssh_rportfwds, &pf, NULL);
5596 if (realpf == NULL) {
5597 error = "Remote port is not recognised";
5598 } else {
5599 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5600 realpf->dport, c);
5601 char buf[1024];
5602 sprintf(buf, "Received remote port open request for %s:%d",
5603 realpf->dhost, realpf->dport);
5604 logevent(buf);
5605 if (e != NULL) {
5606 sprintf(buf, "Port open failed: %s", e);
5607 logevent(buf);
5608 error = "Port open failed";
5609 } else {
5610 logevent("Forwarded port opened successfully");
5611 c->type = CHAN_SOCKDATA;
5612 }
5613 }
32874aea 5614 } else if (typelen == 22 &&
36c2a3e9 5615 !memcmp(type, "auth-agent@openssh.com", 3)) {
32874aea 5616 if (!ssh_agentfwd_enabled)
5617 error = "Agent forwarding is not enabled";
36c2a3e9 5618 else {
32874aea 5619 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5620 c->u.a.lensofar = 0;
32874aea 5621 }
5622 } else {
5623 error = "Unsupported channel type requested";
5624 }
5625
bc240b21 5626 c->remoteid = remid;
32874aea 5627 if (error) {
5628 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5629 ssh2_pkt_adduint32(c->remoteid);
5630 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5631 ssh2_pkt_addstring(error);
5632 ssh2_pkt_addstring("en"); /* language tag */
5633 ssh2_pkt_send();
5634 sfree(c);
5635 } else {
5636 c->localid = alloc_channel_id();
5637 c->closes = 0;
5471d09a 5638 c->v.v2.locwindow = OUR_V2_WINSIZE;
5639 c->v.v2.remwindow = winsize;
5640 c->v.v2.remmaxpkt = pktsize;
5641 bufchain_init(&c->v.v2.outbuffer);
32874aea 5642 add234(ssh_channels, c);
5643 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5644 ssh2_pkt_adduint32(c->remoteid);
5645 ssh2_pkt_adduint32(c->localid);
5471d09a 5646 ssh2_pkt_adduint32(c->v.v2.locwindow);
32874aea 5647 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5648 ssh2_pkt_send();
5649 }
7cca0d81 5650 } else {
8d5de777 5651 bombout(("Strange packet received: type %d", pktin.type));
32874aea 5652 crReturnV;
7cca0d81 5653 }
5654 } else {
32874aea 5655 /*
5656 * We have spare data. Add it to the channel buffer.
5657 */
5658 ssh2_add_channel_data(mainchan, in, inlen);
5659 try_send = TRUE;
5660 }
5661 if (try_send) {
5662 int i;
5663 struct ssh_channel *c;
5664 /*
5665 * Try to send data on all channels if we can.
5666 */
5471d09a 5667 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5668 int bufsize = ssh2_try_send(c);
5669 if (bufsize == 0) {
5670 switch (c->type) {
5671 case CHAN_MAINSESSION:
5672 /* stdin need not receive an unthrottle
5673 * notification since it will be polled */
5674 break;
5675 case CHAN_X11:
5676 x11_unthrottle(c->u.x11.s);
5677 break;
5678 case CHAN_AGENT:
5679 /* agent sockets are request/response and need no
5680 * buffer management */
5681 break;
5682 case CHAN_SOCKDATA:
5683 pfd_unthrottle(c->u.pfd.s);
5684 break;
5685 }
5686 }
5687 }
7cca0d81 5688 }
e5574168 5689 }
5690
5691 crFinishV;
5692}
5693
5694/*
7cca0d81 5695 * Handle the top-level SSH2 protocol.
5696 */
5697static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5698{
5699 if (do_ssh2_transport(in, inlen, ispkt) == 0)
32874aea 5700 return;
7cca0d81 5701 do_ssh2_authconn(in, inlen, ispkt);
5702}
5703
5704/*
8df7a775 5705 * Called to set up the connection.
374330e2 5706 *
5707 * Returns an error message, or NULL on success.
374330e2 5708 */
2184a5d9 5709static char *ssh_init(char *host, int port, char **realhost, int nodelay)
32874aea 5710{
fb09bf1c 5711 char *p;
32874aea 5712
8f203108 5713#ifdef MSCRYPTOAPI
32874aea 5714 if (crypto_startup() == 0)
8f203108 5715 return "Microsoft high encryption pack not installed!";
5716#endif
374330e2 5717
8df7a775 5718 ssh_send_ok = 0;
0965bee0 5719 ssh_editing = 0;
5720 ssh_echoing = 0;
5471d09a 5721 ssh1_throttle_count = 0;
5722 ssh_overall_bufsize = 0;
fd5e5847 5723 ssh_fallback_cmd = 0;
8df7a775 5724
2184a5d9 5725 p = connect_to_host(host, port, realhost, nodelay);
fb09bf1c 5726 if (p != NULL)
5727 return p;
374330e2 5728
374330e2 5729 return NULL;
5730}
5731
5732/*
374330e2 5733 * Called to send data down the Telnet connection.
5734 */
5471d09a 5735static int ssh_send(char *buf, int len)
32874aea 5736{
f78051a1 5737 if (s == NULL || ssh_protocol == NULL)
5471d09a 5738 return 0;
374330e2 5739
5740 ssh_protocol(buf, len, 0);
5471d09a 5741
5742 return ssh_sendbuffer();
5743}
5744
5745/*
5746 * Called to query the current amount of buffered stdin data.
5747 */
5748static int ssh_sendbuffer(void)
5749{
5750 int override_value;
5751
5752 if (s == NULL || ssh_protocol == NULL)
5753 return 0;
5754
5755 /*
5756 * If the SSH socket itself has backed up, add the total backup
5757 * size on that to any individual buffer on the stdin channel.
5758 */
5759 override_value = 0;
5760 if (ssh_throttled_all)
5761 override_value = ssh_overall_bufsize;
5762
5763 if (ssh_version == 1) {
5764 return override_value;
5765 } else if (ssh_version == 2) {
5766 if (!mainchan || mainchan->closes > 0)
5767 return override_value;
5768 else
5769 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5770 }
5771
5772 return 0;
374330e2 5773}
5774
5775/*
6e48c3fe 5776 * Called to set the size of the window from SSH's POV.
374330e2 5777 */
32874aea 5778static void ssh_size(void)
5779{
374330e2 5780 switch (ssh_state) {
5781 case SSH_STATE_BEFORE_SIZE:
3687d221 5782 case SSH_STATE_PREPACKET:
21248260 5783 case SSH_STATE_CLOSED:
374330e2 5784 break; /* do nothing */
5785 case SSH_STATE_INTERMED:
5786 size_needed = TRUE; /* buffer for later */
5787 break;
5788 case SSH_STATE_SESSION:
32874aea 5789 if (!cfg.nopty) {
5790 if (ssh_version == 1) {
5791 send_packet(SSH1_CMSG_WINDOW_SIZE,
5792 PKT_INT, rows, PKT_INT, cols,
5793 PKT_INT, 0, PKT_INT, 0, PKT_END);
5794 } else {
5795 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5796 ssh2_pkt_adduint32(mainchan->remoteid);
5797 ssh2_pkt_addstring("window-change");
5798 ssh2_pkt_addbool(0);
5799 ssh2_pkt_adduint32(cols);
5800 ssh2_pkt_adduint32(rows);
5801 ssh2_pkt_adduint32(0);
5802 ssh2_pkt_adduint32(0);
5803 ssh2_pkt_send();
5804 }
5805 }
5806 break;
374330e2 5807 }
5808}
5809
5810/*
6abbf9e3 5811 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5812 * can send an EOF and collect resulting output (e.g. `plink
5813 * hostname sort').
374330e2 5814 */
32874aea 5815static void ssh_special(Telnet_Special code)
5816{
6abbf9e3 5817 if (code == TS_EOF) {
32874aea 5818 if (ssh_state != SSH_STATE_SESSION) {
5819 /*
5820 * Buffer the EOF in case we are pre-SESSION, so we can
5821 * send it as soon as we reach SESSION.
5822 */
5823 if (code == TS_EOF)
5824 eof_needed = TRUE;
5825 return;
5826 }
5827 if (ssh_version == 1) {
5828 send_packet(SSH1_CMSG_EOF, PKT_END);
5829 } else {
5830 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5831 ssh2_pkt_adduint32(mainchan->remoteid);
5832 ssh2_pkt_send();
5833 }
5834 logevent("Sent EOF message");
ec55b220 5835 } else if (code == TS_PING) {
32874aea 5836 if (ssh_state == SSH_STATE_CLOSED
5837 || ssh_state == SSH_STATE_PREPACKET) return;
5838 if (ssh_version == 1) {
2c9c6388 5839 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
5840 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 5841 } else {
5842 ssh2_pkt_init(SSH2_MSG_IGNORE);
5843 ssh2_pkt_addstring_start();
5844 ssh2_pkt_send();
5845 }
6abbf9e3 5846 } else {
32874aea 5847 /* do nothing */
6abbf9e3 5848 }
374330e2 5849}
5850
d74d141c 5851void *new_sock_channel(Socket s)
5852{
5853 struct ssh_channel *c;
5854 c = smalloc(sizeof(struct ssh_channel));
5855
5856 if (c) {
bc240b21 5857 c->remoteid = -1; /* to be set when open confirmed */
d74d141c 5858 c->localid = alloc_channel_id();
5859 c->closes = 0;
bc240b21 5860 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 5861 c->u.pfd.s = s;
013dd8c0 5862 bufchain_init(&c->v.v2.outbuffer);
d74d141c 5863 add234(ssh_channels, c);
5864 }
5865 return c;
5866}
5867
5471d09a 5868/*
5869 * This is called when stdout/stderr (the entity to which
5870 * from_backend sends data) manages to clear some backlog.
5871 */
5872void ssh_unthrottle(int bufsize)
5873{
5874 if (ssh_version == 1) {
90347b95 5875 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5471d09a 5876 ssh1_stdout_throttling = 0;
5877 ssh1_throttle(-1);
5878 }
5879 } else {
5880 if (mainchan && mainchan->closes == 0)
5881 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5882 }
5883}
5884
d74d141c 5885void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5886{
5887 struct ssh_channel *c = (struct ssh_channel *)channel;
5888 char buf[1024];
5889
5890 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5891 logevent(buf);
5892
bc240b21 5893 if (ssh_version == 1) {
5894 send_packet(SSH1_MSG_PORT_OPEN,
5895 PKT_INT, c->localid,
5896 PKT_STR, hostname,
5897 PKT_INT, port,
5898 //PKT_STR, <org:orgport>,
5899 PKT_END);
5900 } else {
5901 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5902 ssh2_pkt_addstring("direct-tcpip");
5903 ssh2_pkt_adduint32(c->localid);
5471d09a 5904 c->v.v2.locwindow = OUR_V2_WINSIZE;
5905 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
bc240b21 5906 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5907 ssh2_pkt_addstring(hostname);
5908 ssh2_pkt_adduint32(port);
5909 /*
5910 * We make up values for the originator data; partly it's
5911 * too much hassle to keep track, and partly I'm not
5912 * convinced the server should be told details like that
5913 * about my local network configuration.
5914 */
5915 ssh2_pkt_addstring("client-side-connection");
5916 ssh2_pkt_adduint32(0);
5917 ssh2_pkt_send();
5918 }
d74d141c 5919}
5920
5921
32874aea 5922static Socket ssh_socket(void)
5923{
5924 return s;
5925}
8ccc75b0 5926
32874aea 5927static int ssh_sendok(void)
5928{
5929 return ssh_send_ok;
5930}
fb09bf1c 5931
32874aea 5932static int ssh_ldisc(int option)
5933{
5934 if (option == LD_ECHO)
5935 return ssh_echoing;
5936 if (option == LD_EDIT)
5937 return ssh_editing;
0965bee0 5938 return FALSE;
5939}
5940
d8d6c7e5 5941static int ssh_return_exitcode(void)
5942{
5943 return ssh_exitcode;
5944}
5945
374330e2 5946Backend ssh_backend = {
5947 ssh_init,
374330e2 5948 ssh_send,
5471d09a 5949 ssh_sendbuffer,
374330e2 5950 ssh_size,
4017be6d 5951 ssh_special,
8ccc75b0 5952 ssh_socket,
d8d6c7e5 5953 ssh_return_exitcode,
97db3be4 5954 ssh_sendok,
0965bee0 5955 ssh_ldisc,
5471d09a 5956 ssh_unthrottle,
97db3be4 5957 22
bc240b21 5958};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator