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Need to stub frontend_keypress() in console.c as well as window.c.
[u/mdw/putty] / ssh.c
CommitLineData
8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
b4453f49 20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
fb09bf1c 21
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
887035a5 536static void *frontend;
537
f278d6f8 538static int ssh_term_width, ssh_term_height;
539
32874aea 540static tree234 *ssh_channels; /* indexed by local id */
57476f6b 541static struct ssh_channel *mainchan; /* primary session channel */
d8d6c7e5 542static int ssh_exitcode = -1;
57476f6b 543
d74d141c 544static tree234 *ssh_rportfwds;
545
57476f6b 546static enum {
3687d221 547 SSH_STATE_PREPACKET,
57476f6b 548 SSH_STATE_BEFORE_SIZE,
549 SSH_STATE_INTERMED,
550 SSH_STATE_SESSION,
551 SSH_STATE_CLOSED
3687d221 552} ssh_state = SSH_STATE_PREPACKET;
57476f6b 553
3687d221 554static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 555
556static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
557static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 558static unsigned char *deferred_send_data = NULL;
559static int deferred_len = 0, deferred_size = 0;
57476f6b 560
fd5e5847 561/*
562 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
563 * that fails. This variable is the means by which scp.c can reach
564 * into the SSH code and find out which one it got.
565 */
566int ssh_fallback_cmd = 0;
567
57476f6b 568static int ssh_version;
5471d09a 569static int ssh1_throttle_count;
570static int ssh_overall_bufsize;
571static int ssh_throttled_all;
572static int ssh1_stdout_throttling;
32874aea 573static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
57476f6b 574static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
575static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
818ab3bb 576static void ssh_size(int width, int height);
32874aea 577static void ssh_special(Telnet_Special);
5471d09a 578static int ssh2_try_send(struct ssh_channel *c);
32874aea 579static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
580 int len);
5471d09a 581static void ssh_throttle_all(int enable, int bufsize);
582static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
32874aea 583static int (*s_rdpkt) (unsigned char **data, int *datalen);
5471d09a 584static int ssh_sendbuffer(void);
57476f6b 585
586static struct rdpkt1_state_tag {
587 long len, pad, biglen, to_read;
588 unsigned long realcrc, gotcrc;
589 unsigned char *p;
590 int i;
591 int chunk;
592} rdpkt1_state;
593
960e736a 594static struct rdpkt2_state_tag {
595 long len, pad, payload, packetlen, maclen;
596 int i;
597 int cipherblk;
598 unsigned long incoming_sequence;
599} rdpkt2_state;
600
32874aea 601static int ssh_channelcmp(void *av, void *bv)
602{
603 struct ssh_channel *a = (struct ssh_channel *) av;
604 struct ssh_channel *b = (struct ssh_channel *) bv;
605 if (a->localid < b->localid)
606 return -1;
607 if (a->localid > b->localid)
608 return +1;
dacbd0e8 609 return 0;
610}
32874aea 611static int ssh_channelfind(void *av, void *bv)
612{
613 unsigned *a = (unsigned *) av;
614 struct ssh_channel *b = (struct ssh_channel *) bv;
615 if (*a < b->localid)
616 return -1;
617 if (*a > b->localid)
618 return +1;
dacbd0e8 619 return 0;
620}
621
bc240b21 622static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 623{
624 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
625 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
626 int i;
bc240b21 627 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 628 return i < 0 ? -1 : +1;
bc240b21 629 if (a->dport > b->dport)
630 return +1;
631 if (a->dport < b->dport)
632 return -1;
633 return 0;
634}
635
636static int ssh_rportcmp_ssh2(void *av, void *bv)
637{
638 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
639 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 640
bc240b21 641 if (a->sport > b->sport)
d74d141c 642 return +1;
bc240b21 643 if (a->sport < b->sport)
644 return -1;
d74d141c 645 return 0;
646}
647
32874aea 648static int alloc_channel_id(void)
649{
260f3dec 650 const unsigned CHANNEL_NUMBER_OFFSET = 256;
651 unsigned low, high, mid;
d2371c81 652 int tsize;
653 struct ssh_channel *c;
654
655 /*
656 * First-fit allocation of channel numbers: always pick the
657 * lowest unused one. To do this, binary-search using the
658 * counted B-tree to find the largest channel ID which is in a
659 * contiguous sequence from the beginning. (Precisely
660 * everything in that sequence must have ID equal to its tree
661 * index plus CHANNEL_NUMBER_OFFSET.)
662 */
663 tsize = count234(ssh_channels);
664
32874aea 665 low = -1;
666 high = tsize;
d2371c81 667 while (high - low > 1) {
668 mid = (high + low) / 2;
669 c = index234(ssh_channels, mid);
670 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
671 low = mid; /* this one is fine */
672 else
673 high = mid; /* this one is past it */
674 }
675 /*
676 * Now low points to either -1, or the tree index of the
677 * largest ID in the initial sequence.
678 */
679 {
680 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
681 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
682 }
683 return low + 1 + CHANNEL_NUMBER_OFFSET;
684}
685
32874aea 686static void c_write(char *buf, int len)
687{
67779be7 688 if ((flags & FLAG_STDERR)) {
32874aea 689 int i;
690 for (i = 0; i < len; i++)
691 if (buf[i] != '\r')
692 fputc(buf[i], stderr);
fb09bf1c 693 return;
694 }
887035a5 695 from_backend(frontend, 1, buf, len);
3bdaf79d 696}
697
32874aea 698static void c_write_untrusted(char *buf, int len)
699{
a209e957 700 int i;
701 for (i = 0; i < len; i++) {
32874aea 702 if (buf[i] == '\n')
703 c_write("\r\n", 2);
704 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
705 c_write(buf + i, 1);
a209e957 706 }
707}
708
32874aea 709static void c_write_str(char *buf)
710{
1408a877 711 c_write(buf, strlen(buf));
712}
713
fb09bf1c 714/*
715 * Collect incoming data in the incoming packet buffer.
e5574168 716 * Decipher and verify the packet when it is completely read.
717 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 718 * Update the *data and *datalen variables.
719 * Return the additional nr of bytes needed, or 0 when
720 * a complete packet is available.
721 */
e5574168 722static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 723{
57476f6b 724 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 725
726 crBegin;
374330e2 727
32874aea 728 next_packet:
37508af4 729
fb09bf1c 730 pktin.type = 0;
731 pktin.length = 0;
374330e2 732
57476f6b 733 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 734 while ((*datalen) == 0)
32874aea 735 crReturn(4 - st->i);
57476f6b 736 st->len = (st->len << 8) + **data;
fb09bf1c 737 (*data)++, (*datalen)--;
738 }
374330e2 739
57476f6b 740 st->pad = 8 - (st->len % 8);
741 st->biglen = st->len + st->pad;
742 pktin.length = st->len - 5;
fb09bf1c 743
57476f6b 744 if (pktin.maxlen < st->biglen) {
745 pktin.maxlen = st->biglen;
32874aea 746 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
747 srealloc(pktin.data, st->biglen + APIEXTRA));
fb09bf1c 748 if (!pktin.data)
749 fatalbox("Out of memory");
750 }
374330e2 751
57476f6b 752 st->to_read = st->biglen;
753 st->p = pktin.data;
754 while (st->to_read > 0) {
32874aea 755 st->chunk = st->to_read;
fb09bf1c 756 while ((*datalen) == 0)
57476f6b 757 crReturn(st->to_read);
758 if (st->chunk > (*datalen))
759 st->chunk = (*datalen);
760 memcpy(st->p, *data, st->chunk);
761 *data += st->chunk;
762 *datalen -= st->chunk;
763 st->p += st->chunk;
764 st->to_read -= st->chunk;
fb09bf1c 765 }
374330e2 766
9a3a93a5 767 if (cipher && detect_attack(pktin.data, st->biglen, NULL)) {
768 bombout(("Network attack (CRC compensation) detected!"));
769 crReturn(0);
770 }
771
fb09bf1c 772 if (cipher)
57476f6b 773 cipher->decrypt(pktin.data, st->biglen);
374330e2 774
32874aea 775 st->realcrc = crc32(pktin.data, st->biglen - 4);
776 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
57476f6b 777 if (st->gotcrc != st->realcrc) {
8d5de777 778 bombout(("Incorrect CRC received on packet"));
32874aea 779 crReturn(0);
fb09bf1c 780 }
572f871e 781
4ba9b64b 782 pktin.body = pktin.data + st->pad + 1;
783
784 if (ssh1_compressing) {
785 unsigned char *decompblk;
786 int decomplen;
32874aea 787 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
4ba9b64b 788 &decompblk, &decomplen);
789
790 if (pktin.maxlen < st->pad + decomplen) {
791 pktin.maxlen = st->pad + decomplen;
32874aea 792 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
793 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 794 if (!pktin.data)
795 fatalbox("Out of memory");
796 }
797
32874aea 798 memcpy(pktin.body - 1, decompblk, decomplen);
dcbde236 799 sfree(decompblk);
32874aea 800 pktin.length = decomplen - 1;
4ba9b64b 801 }
802
00db133f 803 pktin.type = pktin.body[-1];
804
805 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
806 pktin.body, pktin.length);
807
e5574168 808 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 809 pktin.type == SSH1_SMSG_STDERR_DATA ||
810 pktin.type == SSH1_MSG_DEBUG ||
811 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
812 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3d63ca2e 813 long stringlen = GET_32BIT(pktin.body);
814 if (stringlen + 4 != pktin.length) {
8d5de777 815 bombout(("Received data packet with bogus string length"));
32874aea 816 crReturn(0);
817 }
fb09bf1c 818 }
819
e5574168 820 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 821 /* log debug message */
eb4504cc 822 char buf[512];
3d63ca2e 823 int stringlen = GET_32BIT(pktin.body);
eb4504cc 824 strcpy(buf, "Remote debug message: ");
825 if (stringlen > 480)
826 stringlen = 480;
3d63ca2e 827 memcpy(buf + 8, pktin.body + 4, stringlen);
828 buf[8 + stringlen] = '\0';
fb09bf1c 829 logevent(buf);
830 goto next_packet;
e5574168 831 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 832 /* do nothing */
833 goto next_packet;
834 }
835
38c4a8da 836 if (pktin.type == SSH1_MSG_DISCONNECT) {
837 /* log reason code in disconnect message */
838 char buf[256];
260f3dec 839 unsigned msglen = GET_32BIT(pktin.body);
840 unsigned nowlen;
38c4a8da 841 strcpy(buf, "Remote sent disconnect: ");
842 nowlen = strlen(buf);
32874aea 843 if (msglen > sizeof(buf) - nowlen - 1)
844 msglen = sizeof(buf) - nowlen - 1;
845 memcpy(buf + nowlen, pktin.body + 4, msglen);
846 buf[nowlen + msglen] = '\0';
247308b5 847 /* logevent(buf); (this is now done within the bombout macro) */
4eb195cc 848 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 849 crReturn(0);
38c4a8da 850 }
851
fb09bf1c 852 crFinish(0);
853}
854
e5574168 855static int ssh2_rdpkt(unsigned char **data, int *datalen)
856{
960e736a 857 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 858
859 crBegin;
860
32874aea 861 next_packet:
e5574168 862 pktin.type = 0;
863 pktin.length = 0;
960e736a 864 if (sccipher)
32874aea 865 st->cipherblk = sccipher->blksize;
e5574168 866 else
32874aea 867 st->cipherblk = 8;
960e736a 868 if (st->cipherblk < 8)
32874aea 869 st->cipherblk = 8;
960e736a 870
871 if (pktin.maxlen < st->cipherblk) {
872 pktin.maxlen = st->cipherblk;
32874aea 873 pktin.data =
874 (pktin.data ==
875 NULL ? smalloc(st->cipherblk +
876 APIEXTRA) : srealloc(pktin.data,
877 st->cipherblk +
878 APIEXTRA));
e5574168 879 if (!pktin.data)
880 fatalbox("Out of memory");
881 }
882
883 /*
884 * Acquire and decrypt the first block of the packet. This will
885 * contain the length and padding details.
886 */
32874aea 887 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 888 while ((*datalen) == 0)
32874aea 889 crReturn(st->cipherblk - st->i);
960e736a 890 pktin.data[st->i] = *(*data)++;
32874aea 891 (*datalen)--;
e5574168 892 }
4252c9cc 893
e5574168 894 if (sccipher)
32874aea 895 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 896
897 /*
898 * Now get the length and padding figures.
899 */
960e736a 900 st->len = GET_32BIT(pktin.data);
901 st->pad = pktin.data[4];
e5574168 902
903 /*
717dc483 904 * _Completely_ silly lengths should be stomped on before they
905 * do us any more damage.
906 */
907 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
908 bombout(("Incoming packet was garbled on decryption"));
909 crReturn(0);
910 }
911
912 /*
e5574168 913 * This enables us to deduce the payload length.
914 */
960e736a 915 st->payload = st->len - st->pad - 1;
e5574168 916
960e736a 917 pktin.length = st->payload + 5;
e5574168 918
919 /*
920 * So now we can work out the total packet length.
921 */
960e736a 922 st->packetlen = st->len + 4;
923 st->maclen = scmac ? scmac->len : 0;
e5574168 924
925 /*
926 * Adjust memory allocation if packet is too big.
927 */
32874aea 928 if (pktin.maxlen < st->packetlen + st->maclen) {
929 pktin.maxlen = st->packetlen + st->maclen;
930 pktin.data =
931 (pktin.data ==
932 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
933 pktin.maxlen
934 +
935 APIEXTRA));
e5574168 936 if (!pktin.data)
937 fatalbox("Out of memory");
938 }
939
940 /*
941 * Read and decrypt the remainder of the packet.
942 */
32874aea 943 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
944 st->i++) {
e5574168 945 while ((*datalen) == 0)
960e736a 946 crReturn(st->packetlen + st->maclen - st->i);
947 pktin.data[st->i] = *(*data)++;
32874aea 948 (*datalen)--;
e5574168 949 }
950 /* Decrypt everything _except_ the MAC. */
951 if (sccipher)
32874aea 952 sccipher->decrypt(pktin.data + st->cipherblk,
953 st->packetlen - st->cipherblk);
e5574168 954
955 /*
956 * Check the MAC.
957 */
32874aea 958 if (scmac
959 && !scmac->verify(pktin.data, st->len + 4,
960 st->incoming_sequence)) {
8d5de777 961 bombout(("Incorrect MAC received on packet"));
32874aea 962 crReturn(0);
8d5de777 963 }
32874aea 964 st->incoming_sequence++; /* whether or not we MACed */
e5574168 965
4ba9b64b 966 /*
967 * Decompress packet payload.
968 */
969 {
970 unsigned char *newpayload;
971 int newlen;
32874aea 972 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
4ba9b64b 973 &newpayload, &newlen)) {
32874aea 974 if (pktin.maxlen < newlen + 5) {
975 pktin.maxlen = newlen + 5;
976 pktin.data =
977 (pktin.data ==
978 NULL ? smalloc(pktin.maxlen +
979 APIEXTRA) : srealloc(pktin.data,
980 pktin.maxlen +
981 APIEXTRA));
4ba9b64b 982 if (!pktin.data)
983 fatalbox("Out of memory");
984 }
985 pktin.length = 5 + newlen;
32874aea 986 memcpy(pktin.data + 5, newpayload, newlen);
dcbde236 987 sfree(newpayload);
4ba9b64b 988 }
989 }
990
e5574168 991 pktin.savedpos = 6;
992 pktin.type = pktin.data[5];
e5574168 993
00db133f 994 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
995 pktin.data+6, pktin.length-6);
996
3d63ca2e 997 switch (pktin.type) {
998 /*
999 * These packets we must handle instantly.
1000 */
1001 case SSH2_MSG_DISCONNECT:
1002 {
1003 /* log reason code in disconnect message */
1004 char buf[256];
1005 int reason = GET_32BIT(pktin.data + 6);
1006 unsigned msglen = GET_32BIT(pktin.data + 10);
1007 unsigned nowlen;
1008 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1009 sprintf(buf, "Received disconnect message (%s)",
1010 ssh2_disconnect_reasons[reason]);
1011 } else {
1012 sprintf(buf, "Received disconnect message (unknown type %d)",
1013 reason);
1014 }
1015 logevent(buf);
1016 strcpy(buf, "Disconnection message text: ");
1017 nowlen = strlen(buf);
1018 if (msglen > sizeof(buf) - nowlen - 1)
1019 msglen = sizeof(buf) - nowlen - 1;
1020 memcpy(buf + nowlen, pktin.data + 14, msglen);
1021 buf[nowlen + msglen] = '\0';
1022 logevent(buf);
1023 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1024 reason,
1025 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1026 ssh2_disconnect_reasons[reason] : "unknown",
1027 buf+nowlen));
1028 crReturn(0);
1029 }
1030 break;
1031 case SSH2_MSG_IGNORE:
1032 goto next_packet;
1033 case SSH2_MSG_DEBUG:
1034 {
1035 /* log the debug message */
1036 char buf[512];
1037 /* int display = pktin.body[6]; */
1038 int stringlen = GET_32BIT(pktin.data+7);
1039 int prefix;
1040 strcpy(buf, "Remote debug message: ");
1041 prefix = strlen(buf);
1042 if (stringlen > sizeof(buf)-prefix-1)
1043 stringlen = sizeof(buf)-prefix-1;
1044 memcpy(buf + prefix, pktin.data + 11, stringlen);
1045 buf[prefix + stringlen] = '\0';
1046 logevent(buf);
38c4a8da 1047 }
3d63ca2e 1048 goto next_packet; /* FIXME: print the debug message */
1049
1050 /*
1051 * These packets we need do nothing about here.
1052 */
1053 case SSH2_MSG_UNIMPLEMENTED:
1054 case SSH2_MSG_SERVICE_REQUEST:
1055 case SSH2_MSG_SERVICE_ACCEPT:
1056 case SSH2_MSG_KEXINIT:
1057 case SSH2_MSG_NEWKEYS:
1058 case SSH2_MSG_KEXDH_INIT:
1059 case SSH2_MSG_KEXDH_REPLY:
1060 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1061 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1062 case SSH2_MSG_KEX_DH_GEX_INIT:
1063 case SSH2_MSG_KEX_DH_GEX_REPLY:
1064 case SSH2_MSG_USERAUTH_REQUEST:
1065 case SSH2_MSG_USERAUTH_FAILURE:
1066 case SSH2_MSG_USERAUTH_SUCCESS:
1067 case SSH2_MSG_USERAUTH_BANNER:
1068 case SSH2_MSG_USERAUTH_PK_OK:
1069 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1070 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1071 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1072 case SSH2_MSG_GLOBAL_REQUEST:
1073 case SSH2_MSG_REQUEST_SUCCESS:
1074 case SSH2_MSG_REQUEST_FAILURE:
1075 case SSH2_MSG_CHANNEL_OPEN:
1076 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1077 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1078 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1079 case SSH2_MSG_CHANNEL_DATA:
1080 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1081 case SSH2_MSG_CHANNEL_EOF:
1082 case SSH2_MSG_CHANNEL_CLOSE:
1083 case SSH2_MSG_CHANNEL_REQUEST:
1084 case SSH2_MSG_CHANNEL_SUCCESS:
1085 case SSH2_MSG_CHANNEL_FAILURE:
1086 break;
1087
1088 /*
1089 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1090 */
1091 default:
1092 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
1093 ssh2_pkt_adduint32(st->incoming_sequence - 1);
1094 ssh2_pkt_send();
1095 break;
38c4a8da 1096 }
1097
e5574168 1098 crFinish(0);
1099}
1100
32874aea 1101static void ssh1_pktout_size(int len)
1102{
374330e2 1103 int pad, biglen;
1104
1105 len += 5; /* type and CRC */
32874aea 1106 pad = 8 - (len % 8);
374330e2 1107 biglen = len + pad;
1108
32874aea 1109 pktout.length = len - 5;
374330e2 1110 if (pktout.maxlen < biglen) {
1111 pktout.maxlen = biglen;
8f203108 1112#ifdef MSCRYPTOAPI
fb09bf1c 1113 /* Allocate enough buffer space for extra block
8f203108 1114 * for MS CryptEncrypt() */
32874aea 1115 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
1116 srealloc(pktout.data, biglen + 12));
8f203108 1117#else
32874aea 1118 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
1119 srealloc(pktout.data, biglen + 4));
8f203108 1120#endif
374330e2 1121 if (!pktout.data)
1122 fatalbox("Out of memory");
1123 }
32874aea 1124 pktout.body = pktout.data + 4 + pad + 1;
4ba9b64b 1125}
374330e2 1126
32874aea 1127static void s_wrpkt_start(int type, int len)
1128{
4ba9b64b 1129 ssh1_pktout_size(len);
374330e2 1130 pktout.type = type;
374330e2 1131}
1132
32874aea 1133static int s_wrpkt_prepare(void)
1134{
374330e2 1135 int pad, len, biglen, i;
1136 unsigned long crc;
1137
4ba9b64b 1138 pktout.body[-1] = pktout.type;
1139
00db133f 1140 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1141 pktout.body, pktout.length);
1142
4ba9b64b 1143 if (ssh1_compressing) {
1144 unsigned char *compblk;
1145 int complen;
32874aea 1146 zlib_compress_block(pktout.body - 1, pktout.length + 1,
4ba9b64b 1147 &compblk, &complen);
32874aea 1148 ssh1_pktout_size(complen - 1);
1149 memcpy(pktout.body - 1, compblk, complen);
dcbde236 1150 sfree(compblk);
4ba9b64b 1151 }
1152
374330e2 1153 len = pktout.length + 5; /* type and CRC */
32874aea 1154 pad = 8 - (len % 8);
374330e2 1155 biglen = len + pad;
1156
32874aea 1157 for (i = 0; i < pad; i++)
1158 pktout.data[i + 4] = random_byte();
1159 crc = crc32(pktout.data + 4, biglen - 4);
1160 PUT_32BIT(pktout.data + biglen, crc);
fb09bf1c 1161 PUT_32BIT(pktout.data, len);
374330e2 1162
1163 if (cipher)
32874aea 1164 cipher->encrypt(pktout.data + 4, biglen);
374330e2 1165
32874aea 1166 return biglen + 4;
39065bed 1167}
1168
32874aea 1169static void s_wrpkt(void)
1170{
5471d09a 1171 int len, backlog;
39065bed 1172 len = s_wrpkt_prepare();
5471d09a 1173 backlog = sk_write(s, pktout.data, len);
1174 if (backlog > SSH_MAX_BACKLOG)
1175 ssh_throttle_all(1, backlog);
39065bed 1176}
1177
32874aea 1178static void s_wrpkt_defer(void)
1179{
39065bed 1180 int len;
1181 len = s_wrpkt_prepare();
1182 if (deferred_len + len > deferred_size) {
32874aea 1183 deferred_size = deferred_len + len + 128;
1184 deferred_send_data = srealloc(deferred_send_data, deferred_size);
39065bed 1185 }
32874aea 1186 memcpy(deferred_send_data + deferred_len, pktout.data, len);
39065bed 1187 deferred_len += len;
374330e2 1188}
1189
fb09bf1c 1190/*
39065bed 1191 * Construct a packet with the specified contents.
fb09bf1c 1192 */
39065bed 1193static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1194{
fb09bf1c 1195 unsigned char *p, *argp, argchar;
1196 unsigned long argint;
1197 int pktlen, argtype, arglen;
7cca0d81 1198 Bignum bn;
fb09bf1c 1199
1200 pktlen = 0;
39065bed 1201 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1202 switch (argtype) {
1203 case PKT_INT:
39065bed 1204 (void) va_arg(ap1, int);
fb09bf1c 1205 pktlen += 4;
1206 break;
1207 case PKT_CHAR:
39065bed 1208 (void) va_arg(ap1, char);
fb09bf1c 1209 pktlen++;
1210 break;
1211 case PKT_DATA:
39065bed 1212 (void) va_arg(ap1, unsigned char *);
1213 arglen = va_arg(ap1, int);
fb09bf1c 1214 pktlen += arglen;
1215 break;
1216 case PKT_STR:
39065bed 1217 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1218 arglen = strlen(argp);
1219 pktlen += 4 + arglen;
1220 break;
7cca0d81 1221 case PKT_BIGNUM:
39065bed 1222 bn = va_arg(ap1, Bignum);
32874aea 1223 pktlen += ssh1_bignum_length(bn);
7cca0d81 1224 break;
fb09bf1c 1225 default:
1226 assert(0);
1227 }
1228 }
fb09bf1c 1229
1230 s_wrpkt_start(pkttype, pktlen);
1231 p = pktout.body;
1232
39065bed 1233 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1234 switch (argtype) {
1235 case PKT_INT:
39065bed 1236 argint = va_arg(ap2, int);
fb09bf1c 1237 PUT_32BIT(p, argint);
1238 p += 4;
1239 break;
1240 case PKT_CHAR:
39065bed 1241 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1242 *p = argchar;
1243 p++;
1244 break;
1245 case PKT_DATA:
39065bed 1246 argp = va_arg(ap2, unsigned char *);
1247 arglen = va_arg(ap2, int);
fb09bf1c 1248 memcpy(p, argp, arglen);
1249 p += arglen;
1250 break;
1251 case PKT_STR:
39065bed 1252 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1253 arglen = strlen(argp);
1254 PUT_32BIT(p, arglen);
1255 memcpy(p + 4, argp, arglen);
1256 p += 4 + arglen;
1257 break;
7cca0d81 1258 case PKT_BIGNUM:
39065bed 1259 bn = va_arg(ap2, Bignum);
32874aea 1260 p += ssh1_write_bignum(p, bn);
7cca0d81 1261 break;
fb09bf1c 1262 }
1263 }
39065bed 1264}
fb09bf1c 1265
32874aea 1266static void send_packet(int pkttype, ...)
1267{
39065bed 1268 va_list ap1, ap2;
1269 va_start(ap1, pkttype);
1270 va_start(ap2, pkttype);
1271 construct_packet(pkttype, ap1, ap2);
fb09bf1c 1272 s_wrpkt();
1273}
1274
32874aea 1275static void defer_packet(int pkttype, ...)
1276{
39065bed 1277 va_list ap1, ap2;
1278 va_start(ap1, pkttype);
1279 va_start(ap2, pkttype);
1280 construct_packet(pkttype, ap1, ap2);
1281 s_wrpkt_defer();
1282}
1283
32874aea 1284static int ssh_versioncmp(char *a, char *b)
1285{
9697bfd2 1286 char *ae, *be;
1287 unsigned long av, bv;
1288
43aa02a7 1289 av = strtoul(a, &ae, 10);
1290 bv = strtoul(b, &be, 10);
32874aea 1291 if (av != bv)
1292 return (av < bv ? -1 : +1);
1293 if (*ae == '.')
1294 ae++;
1295 if (*be == '.')
1296 be++;
43aa02a7 1297 av = strtoul(ae, &ae, 10);
1298 bv = strtoul(be, &be, 10);
32874aea 1299 if (av != bv)
1300 return (av < bv ? -1 : +1);
9697bfd2 1301 return 0;
1302}
1303
e5574168 1304
1305/*
a92dd380 1306 * Utility routines for putting an SSH-protocol `string' and
1307 * `uint32' into a SHA state.
e5574168 1308 */
1309#include <stdio.h>
32874aea 1310static void sha_string(SHA_State * s, void *str, int len)
1311{
e5574168 1312 unsigned char lenblk[4];
e5574168 1313 PUT_32BIT(lenblk, len);
e5574168 1314 SHA_Bytes(s, lenblk, 4);
e5574168 1315 SHA_Bytes(s, str, len);
1316}
1317
32874aea 1318static void sha_uint32(SHA_State * s, unsigned i)
1319{
a92dd380 1320 unsigned char intblk[4];
1321 PUT_32BIT(intblk, i);
1322 SHA_Bytes(s, intblk, 4);
1323}
1324
7cca0d81 1325/*
1326 * SSH2 packet construction functions.
1327 */
32874aea 1328static void ssh2_pkt_ensure(int length)
1329{
783415f8 1330 if (pktout.maxlen < length) {
32874aea 1331 pktout.maxlen = length + 256;
1332 pktout.data =
1333 (pktout.data ==
1334 NULL ? smalloc(pktout.maxlen +
1335 APIEXTRA) : srealloc(pktout.data,
1336 pktout.maxlen +
1337 APIEXTRA));
1338 if (!pktout.data)
1339 fatalbox("Out of memory");
7cca0d81 1340 }
783415f8 1341}
32874aea 1342static void ssh2_pkt_adddata(void *data, int len)
1343{
783415f8 1344 pktout.length += len;
1345 ssh2_pkt_ensure(pktout.length);
32874aea 1346 memcpy(pktout.data + pktout.length - len, data, len);
7cca0d81 1347}
32874aea 1348static void ssh2_pkt_addbyte(unsigned char byte)
1349{
7cca0d81 1350 ssh2_pkt_adddata(&byte, 1);
1351}
32874aea 1352static void ssh2_pkt_init(int pkt_type)
1353{
7cca0d81 1354 pktout.length = 5;
32874aea 1355 ssh2_pkt_addbyte((unsigned char) pkt_type);
7cca0d81 1356}
32874aea 1357static void ssh2_pkt_addbool(unsigned char value)
1358{
7cca0d81 1359 ssh2_pkt_adddata(&value, 1);
1360}
32874aea 1361static void ssh2_pkt_adduint32(unsigned long value)
1362{
7cca0d81 1363 unsigned char x[4];
1364 PUT_32BIT(x, value);
1365 ssh2_pkt_adddata(x, 4);
1366}
32874aea 1367static void ssh2_pkt_addstring_start(void)
1368{
7cca0d81 1369 ssh2_pkt_adduint32(0);
1370 pktout.savedpos = pktout.length;
1371}
32874aea 1372static void ssh2_pkt_addstring_str(char *data)
1373{
7cca0d81 1374 ssh2_pkt_adddata(data, strlen(data));
1375 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1376 pktout.length - pktout.savedpos);
7cca0d81 1377}
32874aea 1378static void ssh2_pkt_addstring_data(char *data, int len)
1379{
7cca0d81 1380 ssh2_pkt_adddata(data, len);
1381 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1382 pktout.length - pktout.savedpos);
7cca0d81 1383}
32874aea 1384static void ssh2_pkt_addstring(char *data)
1385{
7cca0d81 1386 ssh2_pkt_addstring_start();
1387 ssh2_pkt_addstring_str(data);
1388}
32874aea 1389static char *ssh2_mpint_fmt(Bignum b, int *len)
1390{
7cca0d81 1391 unsigned char *p;
32874aea 1392 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1393 p = smalloc(n + 1);
7cca0d81 1394 if (!p)
32874aea 1395 fatalbox("out of memory");
7cca0d81 1396 p[0] = 0;
3709bfe9 1397 for (i = 1; i <= n; i++)
32874aea 1398 p[i] = bignum_byte(b, n - i);
7cca0d81 1399 i = 0;
32874aea 1400 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1401 i++;
1402 memmove(p, p + i, n + 1 - i);
1403 *len = n + 1 - i;
7cca0d81 1404 return p;
1405}
32874aea 1406static void ssh2_pkt_addmp(Bignum b)
1407{
7cca0d81 1408 unsigned char *p;
1409 int len;
1410 p = ssh2_mpint_fmt(b, &len);
1411 ssh2_pkt_addstring_start();
1412 ssh2_pkt_addstring_data(p, len);
dcbde236 1413 sfree(p);
7cca0d81 1414}
b185170a 1415
1416/*
1417 * Construct an SSH2 final-form packet: compress it, encrypt it,
1418 * put the MAC on it. Final packet, ready to be sent, is stored in
1419 * pktout.data. Total length is returned.
1420 */
32874aea 1421static int ssh2_pkt_construct(void)
1422{
7cca0d81 1423 int cipherblk, maclen, padding, i;
1424 static unsigned long outgoing_sequence = 0;
1425
00db133f 1426 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1427 pktout.data + 6, pktout.length - 6);
1428
7cca0d81 1429 /*
4ba9b64b 1430 * Compress packet payload.
1431 */
4ba9b64b 1432 {
1433 unsigned char *newpayload;
1434 int newlen;
32874aea 1435 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
4ba9b64b 1436 &newpayload, &newlen)) {
1437 pktout.length = 5;
1438 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1439 sfree(newpayload);
4ba9b64b 1440 }
1441 }
1442
1443 /*
7cca0d81 1444 * Add padding. At least four bytes, and must also bring total
1445 * length (minus MAC) up to a multiple of the block size.
1446 */
32874aea 1447 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1448 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1449 padding = 4;
32874aea 1450 padding +=
1451 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1452 maclen = csmac ? csmac->len : 0;
1453 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1454 pktout.data[4] = padding;
1455 for (i = 0; i < padding; i++)
32874aea 1456 pktout.data[pktout.length + i] = random_byte();
7cca0d81 1457 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1458 if (csmac)
32874aea 1459 csmac->generate(pktout.data, pktout.length + padding,
1460 outgoing_sequence);
1461 outgoing_sequence++; /* whether or not we MACed */
7cca0d81 1462
7cca0d81 1463 if (cscipher)
32874aea 1464 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1465
b185170a 1466 /* Ready-to-send packet starts at pktout.data. We return length. */
1467 return pktout.length + padding + maclen;
1468}
1469
1470/*
1471 * Construct and send an SSH2 packet immediately.
1472 */
32874aea 1473static void ssh2_pkt_send(void)
1474{
5471d09a 1475 int len;
1476 int backlog;
1477 len = ssh2_pkt_construct();
1478 backlog = sk_write(s, pktout.data, len);
1479 if (backlog > SSH_MAX_BACKLOG)
1480 ssh_throttle_all(1, backlog);
b185170a 1481}
1482
1483/*
1484 * Construct an SSH2 packet and add it to a deferred data block.
1485 * Useful for sending multiple packets in a single sk_write() call,
1486 * to prevent a traffic-analysing listener from being able to work
1487 * out the length of any particular packet (such as the password
1488 * packet).
1489 *
1490 * Note that because SSH2 sequence-numbers its packets, this can
1491 * NOT be used as an m4-style `defer' allowing packets to be
1492 * constructed in one order and sent in another.
1493 */
32874aea 1494static void ssh2_pkt_defer(void)
1495{
b185170a 1496 int len = ssh2_pkt_construct();
1497 if (deferred_len + len > deferred_size) {
32874aea 1498 deferred_size = deferred_len + len + 128;
1499 deferred_send_data = srealloc(deferred_send_data, deferred_size);
b185170a 1500 }
32874aea 1501 memcpy(deferred_send_data + deferred_len, pktout.data, len);
b185170a 1502 deferred_len += len;
1503}
1504
1505/*
1506 * Send the whole deferred data block constructed by
39065bed 1507 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1508 */
32874aea 1509static void ssh_pkt_defersend(void)
1510{
5471d09a 1511 int backlog;
1512 backlog = sk_write(s, deferred_send_data, deferred_len);
b185170a 1513 deferred_len = deferred_size = 0;
1514 sfree(deferred_send_data);
1515 deferred_send_data = NULL;
5471d09a 1516 if (backlog > SSH_MAX_BACKLOG)
1517 ssh_throttle_all(1, backlog);
7cca0d81 1518}
1519
1520#if 0
32874aea 1521void bndebug(char *string, Bignum b)
1522{
7cca0d81 1523 unsigned char *p;
1524 int i, len;
1525 p = ssh2_mpint_fmt(b, &len);
1526 debug(("%s", string));
1527 for (i = 0; i < len; i++)
32874aea 1528 debug((" %02x", p[i]));
765c4200 1529 debug(("\n"));
dcbde236 1530 sfree(p);
7cca0d81 1531}
1532#endif
1533
32874aea 1534static void sha_mpint(SHA_State * s, Bignum b)
1535{
7cca0d81 1536 unsigned char *p;
1537 int len;
1538 p = ssh2_mpint_fmt(b, &len);
1539 sha_string(s, p, len);
dcbde236 1540 sfree(p);
7cca0d81 1541}
1542
1543/*
1544 * SSH2 packet decode functions.
1545 */
32874aea 1546static unsigned long ssh2_pkt_getuint32(void)
1547{
7cca0d81 1548 unsigned long value;
1549 if (pktin.length - pktin.savedpos < 4)
32874aea 1550 return 0; /* arrgh, no way to decline (FIXME?) */
1551 value = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1552 pktin.savedpos += 4;
1553 return value;
1554}
32874aea 1555static int ssh2_pkt_getbool(void)
1556{
65a22376 1557 unsigned long value;
1558 if (pktin.length - pktin.savedpos < 1)
32874aea 1559 return 0; /* arrgh, no way to decline (FIXME?) */
65a22376 1560 value = pktin.data[pktin.savedpos] != 0;
1561 pktin.savedpos++;
1562 return value;
1563}
32874aea 1564static void ssh2_pkt_getstring(char **p, int *length)
1565{
7cca0d81 1566 *p = NULL;
45068b27 1567 *length = 0;
7cca0d81 1568 if (pktin.length - pktin.savedpos < 4)
32874aea 1569 return;
1570 *length = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1571 pktin.savedpos += 4;
1572 if (pktin.length - pktin.savedpos < *length)
32874aea 1573 return;
1574 *p = pktin.data + pktin.savedpos;
7cca0d81 1575 pktin.savedpos += *length;
1576}
32874aea 1577static Bignum ssh2_pkt_getmp(void)
1578{
7cca0d81 1579 char *p;
3709bfe9 1580 int length;
7cca0d81 1581 Bignum b;
1582
1583 ssh2_pkt_getstring(&p, &length);
1584 if (!p)
32874aea 1585 return NULL;
8d5de777 1586 if (p[0] & 0x80) {
32874aea 1587 bombout(("internal error: Can't handle negative mpints"));
1588 return NULL;
8d5de777 1589 }
3709bfe9 1590 b = bignum_from_bytes(p, length);
7cca0d81 1591 return b;
1592}
1593
7d503c31 1594/*
1dd353b5 1595 * Helper function to add an SSH2 signature blob to a packet.
1596 * Expects to be shown the public key blob as well as the signature
1597 * blob. Normally works just like ssh2_pkt_addstring, but will
1598 * fiddle with the signature packet if necessary for
1599 * BUG_SSH2_RSA_PADDING.
1600 */
1601static void ssh2_add_sigblob(void *pkblob_v, int pkblob_len,
1602 void *sigblob_v, int sigblob_len)
1603{
1604 unsigned char *pkblob = (unsigned char *)pkblob_v;
1605 unsigned char *sigblob = (unsigned char *)sigblob_v;
1606
1607 /* dmemdump(pkblob, pkblob_len); */
1608 /* dmemdump(sigblob, sigblob_len); */
1609
1610 /*
1611 * See if this is in fact an ssh-rsa signature and a buggy
1612 * server; otherwise we can just do this the easy way.
1613 */
1614 if ((ssh_remote_bugs & BUG_SSH2_RSA_PADDING) &&
1615 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1616 int pos, len, siglen;
1617
1618 /*
1619 * Find the byte length of the modulus.
1620 */
1621
1622 pos = 4+7; /* skip over "ssh-rsa" */
1623 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1624 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1625 pos += 4; /* find modulus itself */
1626 while (len > 0 && pkblob[pos] == 0)
1627 len--, pos++;
1628 /* debug(("modulus length is %d\n", len)); */
1629
1630 /*
1631 * Now find the signature integer.
1632 */
1633 pos = 4+7; /* skip over "ssh-rsa" */
1634 siglen = GET_32BIT(sigblob+pos);
1635 /* debug(("signature length is %d\n", siglen)); */
1636
1637 if (len != siglen) {
1638 unsigned char newlen[4];
1639 ssh2_pkt_addstring_start();
1640 ssh2_pkt_addstring_data(sigblob, pos);
1641 /* dmemdump(sigblob, pos); */
1642 pos += 4; /* point to start of actual sig */
1643 PUT_32BIT(newlen, len);
1644 ssh2_pkt_addstring_data(newlen, 4);
1645 /* dmemdump(newlen, 4); */
1646 newlen[0] = 0;
1647 while (len-- > siglen) {
1648 ssh2_pkt_addstring_data(newlen, 1);
1649 /* dmemdump(newlen, 1); */
1650 }
1651 ssh2_pkt_addstring_data(sigblob+pos, siglen);
1652 /* dmemdump(sigblob+pos, siglen); */
1653 return;
1654 }
1655
1656 /* Otherwise fall through and do it the easy way. */
1657 }
1658
1659 ssh2_pkt_addstring_start();
1660 ssh2_pkt_addstring_data(sigblob, sigblob_len);
1661}
1662
1663/*
7d503c31 1664 * Examine the remote side's version string and compare it against
1665 * a list of known buggy implementations.
1666 */
32874aea 1667static void ssh_detect_bugs(char *vstring)
1668{
1669 char *imp; /* pointer to implementation part */
7d503c31 1670 imp = vstring;
1671 imp += strcspn(imp, "-");
bd358db1 1672 if (*imp) imp++;
7d503c31 1673 imp += strcspn(imp, "-");
bd358db1 1674 if (*imp) imp++;
7d503c31 1675
1676 ssh_remote_bugs = 0;
1677
2c9c6388 1678 if (cfg.sshbug_ignore1 == BUG_ON ||
1679 (cfg.sshbug_ignore1 == BUG_AUTO &&
1680 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1681 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1682 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
32874aea 1683 /*
1684 * These versions don't support SSH1_MSG_IGNORE, so we have
1685 * to use a different defence against password length
1686 * sniffing.
1687 */
1688 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1689 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1690 }
1691
2c9c6388 1692 if (cfg.sshbug_plainpw1 == BUG_ON ||
1693 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1694 (!strcmp(imp, "Cisco-1.25")))) {
bd358db1 1695 /*
1696 * These versions need a plain password sent; they can't
1697 * handle having a null and a random length of data after
1698 * the password.
1699 */
1700 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1701 logevent("We believe remote version needs a plain SSH1 password");
1702 }
1703
2c9c6388 1704 if (cfg.sshbug_rsa1 == BUG_ON ||
1705 (cfg.sshbug_rsa1 == BUG_AUTO &&
1706 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1707 /*
1708 * These versions apparently have no clue whatever about
1709 * RSA authentication and will panic and die if they see
1710 * an AUTH_RSA message.
1711 */
1712 ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
1713 logevent("We believe remote version can't handle RSA authentication");
1714 }
1715
2c9c6388 1716 if (cfg.sshbug_hmac2 == BUG_ON ||
1717 (cfg.sshbug_hmac2 == BUG_AUTO &&
1718 (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1719 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1720 !strncmp(imp, "2.1 ", 4)))) {
32874aea 1721 /*
1722 * These versions have the HMAC bug.
1723 */
1724 ssh_remote_bugs |= BUG_SSH2_HMAC;
1725 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1726 }
1dd353b5 1727
2c9c6388 1728 if (cfg.sshbug_derivekey2 == BUG_ON ||
1729 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1730 (!strncmp(imp, "2.0.", 4)))) {
088bde77 1731 /*
1732 * These versions have the key-derivation bug (failing to
1733 * include the literal shared secret in the hashes that
1734 * generate the keys).
1735 */
1736 ssh_remote_bugs |= BUG_SSH2_DERIVEKEY;
1737 logevent("We believe remote version has SSH2 key-derivation bug");
1738 }
1739
2c9c6388 1740 if (cfg.sshbug_rsapad2 == BUG_ON ||
1741 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1742 ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1743 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')))){
1dd353b5 1744 /*
1745 * These versions have the SSH2 RSA padding bug.
1746 */
1747 ssh_remote_bugs |= BUG_SSH2_RSA_PADDING;
1748 logevent("We believe remote version has SSH2 RSA padding bug");
1749 }
8e975795 1750
1751 if (cfg.sshbug_dhgex2 == BUG_ON) {
1752 /*
1753 * These versions have the SSH2 DH GEX bug.
1754 */
1755 ssh_remote_bugs |= BUG_SSH2_DH_GEX;
1756 logevent("We believe remote version has SSH2 DH group exchange bug");
1757 }
7d503c31 1758}
1759
32874aea 1760static int do_ssh_init(unsigned char c)
1761{
2d466ffd 1762 static int vslen;
8df7a775 1763 static char version[10];
50526e47 1764 static char *vstring;
1765 static int vstrsize;
1766 static char *vlog;
8df7a775 1767 static int i;
38d228a2 1768 static int proto1, proto2;
374330e2 1769
8df7a775 1770 crBegin;
1771
1772 /* Search for the string "SSH-" in the input. */
374330e2 1773 i = 0;
8df7a775 1774 while (1) {
1775 static const int transS[] = { 1, 2, 2, 1 };
1776 static const int transH[] = { 0, 0, 3, 0 };
1777 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1778 if (c == 'S')
1779 i = transS[i];
1780 else if (c == 'H')
1781 i = transH[i];
1782 else if (c == '-')
1783 i = transminus[i];
1784 else
1785 i = 0;
8df7a775 1786 if (i < 0)
1787 break;
1788 crReturn(1); /* get another character */
374330e2 1789 }
8df7a775 1790
50526e47 1791 vstrsize = 16;
bd358db1 1792 vstring = smalloc(vstrsize);
c5e9c988 1793 strcpy(vstring, "SSH-");
50526e47 1794 vslen = 4;
374330e2 1795 i = 0;
1796 while (1) {
8df7a775 1797 crReturn(1); /* get another char */
32874aea 1798 if (vslen >= vstrsize - 1) {
1799 vstrsize += 16;
1800 vstring = srealloc(vstring, vstrsize);
1801 }
1802 vstring[vslen++] = c;
374330e2 1803 if (i >= 0) {
1804 if (c == '-') {
1805 version[i] = '\0';
1806 i = -1;
32874aea 1807 } else if (i < sizeof(version) - 1)
374330e2 1808 version[i++] = c;
32874aea 1809 } else if (c == '\n')
374330e2 1810 break;
1811 }
1812
db7d555c 1813 ssh_agentfwd_enabled = FALSE;
960e736a 1814 rdpkt2_state.incoming_sequence = 0;
1815
50526e47 1816 vstring[vslen] = 0;
9275ca8a 1817 vlog = smalloc(20 + vslen);
bd358db1 1818 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
c5e9c988 1819 sprintf(vlog, "Server version: %s", vstring);
c5e9c988 1820 logevent(vlog);
bd358db1 1821 ssh_detect_bugs(vstring);
9275ca8a 1822 sfree(vlog);
c5e9c988 1823
adf799dd 1824 /*
38d228a2 1825 * Decide which SSH protocol version to support.
adf799dd 1826 */
38d228a2 1827
1828 /* Anything strictly below "2.0" means protocol 1 is supported. */
1829 proto1 = ssh_versioncmp(version, "2.0") < 0;
1830 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
daa72738 1831 proto2 = ssh_versioncmp(version, "1.99") >= 0;
38d228a2 1832
1833 if (cfg.sshprot == 0 && !proto1) {
1834 bombout(("SSH protocol version 1 required by user but not provided by server"));
1835 crReturn(0);
1836 }
1837 if (cfg.sshprot == 3 && !proto2) {
1838 bombout(("SSH protocol version 2 required by user but not provided by server"));
1839 crReturn(0);
1840 }
1841
daa72738 1842 if (proto2 && (cfg.sshprot >= 2 || !proto1)) {
32874aea 1843 /*
38d228a2 1844 * Use v2 protocol.
32874aea 1845 */
1846 char verstring[80], vlog[100];
1847 sprintf(verstring, "SSH-2.0-%s", sshver);
1848 SHA_Init(&exhashbase);
1849 /*
1850 * Hash our version string and their version string.
1851 */
1852 sha_string(&exhashbase, verstring, strlen(verstring));
1853 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1854 sprintf(vlog, "We claim version: %s", verstring);
1855 logevent(vlog);
1856 strcat(verstring, "\n");
1857 logevent("Using SSH protocol version 2");
1858 sk_write(s, verstring, strlen(verstring));
1859 ssh_protocol = ssh2_protocol;
1860 ssh_version = 2;
1861 s_rdpkt = ssh2_rdpkt;
e5574168 1862 } else {
32874aea 1863 /*
38d228a2 1864 * Use v1 protocol.
32874aea 1865 */
1866 char verstring[80], vlog[100];
1867 sprintf(verstring, "SSH-%s-%s",
1868 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1869 sshver);
1870 sprintf(vlog, "We claim version: %s", verstring);
1871 logevent(vlog);
1872 strcat(verstring, "\n");
759712a6 1873
32874aea 1874 logevent("Using SSH protocol version 1");
1875 sk_write(s, verstring, strlen(verstring));
1876 ssh_protocol = ssh1_protocol;
1877 ssh_version = 1;
1878 s_rdpkt = ssh1_rdpkt;
e5574168 1879 }
3687d221 1880 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1881
50526e47 1882 sfree(vstring);
50526e47 1883
8df7a775 1884 crFinish(0);
1885}
1886
1887static void ssh_gotdata(unsigned char *data, int datalen)
1888{
1889 crBegin;
1890
1891 /*
1892 * To begin with, feed the characters one by one to the
1893 * protocol initialisation / selection function do_ssh_init().
1894 * When that returns 0, we're done with the initial greeting
1895 * exchange and can move on to packet discipline.
1896 */
1897 while (1) {
1898 int ret;
1899 if (datalen == 0)
1900 crReturnV; /* more data please */
1901 ret = do_ssh_init(*data);
32874aea 1902 data++;
1903 datalen--;
8df7a775 1904 if (ret == 0)
1905 break;
1906 }
1907
1908 /*
1909 * We emerge from that loop when the initial negotiation is
1910 * over and we have selected an s_rdpkt function. Now pass
1911 * everything to s_rdpkt, and then pass the resulting packets
1912 * to the proper protocol handler.
1913 */
1914 if (datalen == 0)
1915 crReturnV;
1916 while (1) {
1917 while (datalen > 0) {
32874aea 1918 if (s_rdpkt(&data, &datalen) == 0) {
e14d0f19 1919 if (ssh_state == SSH_STATE_CLOSED) {
1920 return;
1921 }
8df7a775 1922 ssh_protocol(NULL, 0, 1);
1923 if (ssh_state == SSH_STATE_CLOSED) {
1924 return;
1925 }
1926 }
1927 }
1928 crReturnV;
1929 }
1930 crFinishV;
1931}
1932
32874aea 1933static int ssh_closing(Plug plug, char *error_msg, int error_code,
1934 int calling_back)
1935{
7e78000d 1936 ssh_state = SSH_STATE_CLOSED;
f3ab576e 1937 if (s) {
1938 sk_close(s);
1939 s = NULL;
1940 }
7e78000d 1941 if (error_msg) {
32874aea 1942 /* A socket error has occurred. */
247308b5 1943 logevent(error_msg);
32874aea 1944 connection_fatal(error_msg);
7e78000d 1945 } else {
1946 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1947 }
7e78000d 1948 return 0;
1949}
1950
32874aea 1951static int ssh_receive(Plug plug, int urgent, char *data, int len)
1952{
1953 ssh_gotdata(data, len);
3257deae 1954 if (ssh_state == SSH_STATE_CLOSED) {
32874aea 1955 if (s) {
1956 sk_close(s);
1957 s = NULL;
1958 }
1959 return 0;
3257deae 1960 }
fef97f43 1961 return 1;
374330e2 1962}
1963
5471d09a 1964static void ssh_sent(Plug plug, int bufsize)
1965{
1966 /*
1967 * If the send backlog on the SSH socket itself clears, we
1968 * should unthrottle the whole world if it was throttled.
1969 */
1970 if (bufsize < SSH_MAX_BACKLOG)
1971 ssh_throttle_all(0, bufsize);
1972}
1973
fb09bf1c 1974/*
8df7a775 1975 * Connect to specified host and port.
1976 * Returns an error message, or NULL on success.
6e1ebb76 1977 * Also places the canonical host name into `realhost'. It must be
1978 * freed by the caller.
8df7a775 1979 */
2184a5d9 1980static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
8df7a775 1981{
7e78000d 1982 static struct plug_function_table fn_table = {
1983 ssh_closing,
5471d09a 1984 ssh_receive,
1985 ssh_sent,
1986 NULL
7e78000d 1987 }, *fn_table_ptr = &fn_table;
1988
8df7a775 1989 SockAddr addr;
1990 char *err;
1991#ifdef FWHACK
1992 char *FWhost;
1993 int FWport;
1994#endif
1995
32874aea 1996 savedhost = smalloc(1 + strlen(host));
8df7a775 1997 if (!savedhost)
1998 fatalbox("Out of memory");
1999 strcpy(savedhost, host);
2000
2001 if (port < 0)
2002 port = 22; /* default ssh port */
2003 savedport = port;
2004
2005#ifdef FWHACK
2006 FWhost = host;
2007 FWport = port;
2008 host = FWSTR;
2009 port = 23;
2010#endif
2011
2012 /*
2013 * Try to find host.
2014 */
3ad9d396 2015 {
2016 char buf[200];
2017 sprintf(buf, "Looking up host \"%.170s\"", host);
2018 logevent(buf);
2019 }
8df7a775 2020 addr = sk_namelookup(host, realhost);
32874aea 2021 if ((err = sk_addr_error(addr)))
8df7a775 2022 return err;
2023
2024#ifdef FWHACK
6e1ebb76 2025 *realhost = strdup(FWhost);
8df7a775 2026#endif
2027
2028 /*
2029 * Open socket.
2030 */
3ad9d396 2031 {
2032 char buf[200], addrbuf[100];
2033 sk_getaddr(addr, addrbuf, 100);
2034 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
2035 logevent(buf);
2036 }
8eebd221 2037 s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
67c4ba2e 2038 if ((err = sk_socket_error(s))) {
2039 s = NULL;
8df7a775 2040 return err;
67c4ba2e 2041 }
8df7a775 2042
2043#ifdef FWHACK
2044 sk_write(s, "connect ", 8);
2045 sk_write(s, FWhost, strlen(FWhost));
2046 {
2047 char buf[20];
2048 sprintf(buf, " %d\n", FWport);
2049 sk_write(s, buf, strlen(buf));
2050 }
2051#endif
2052
2053 return NULL;
2054}
2055
2056/*
5471d09a 2057 * Throttle or unthrottle the SSH connection.
2058 */
2059static void ssh1_throttle(int adjust)
2060{
2061 int old_count = ssh1_throttle_count;
2062 ssh1_throttle_count += adjust;
2063 assert(ssh1_throttle_count >= 0);
2064 if (ssh1_throttle_count && !old_count) {
2065 sk_set_frozen(s, 1);
2066 } else if (!ssh1_throttle_count && old_count) {
2067 sk_set_frozen(s, 0);
2068 }
2069}
2070
2071/*
2072 * Throttle or unthrottle _all_ local data streams (for when sends
2073 * on the SSH connection itself back up).
2074 */
2075static void ssh_throttle_all(int enable, int bufsize)
2076{
2077 int i;
2078 struct ssh_channel *c;
2079
2080 if (enable == ssh_throttled_all)
2081 return;
2082 ssh_throttled_all = enable;
2083 ssh_overall_bufsize = bufsize;
2084 if (!ssh_channels)
2085 return;
2086 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
2087 switch (c->type) {
2088 case CHAN_MAINSESSION:
2089 /*
2090 * This is treated separately, outside the switch.
2091 */
2092 break;
2093 case CHAN_X11:
2094 x11_override_throttle(c->u.x11.s, enable);
2095 break;
2096 case CHAN_AGENT:
2097 /* Agent channels require no buffer management. */
2098 break;
2099 case CHAN_SOCKDATA:
2100 pfd_override_throttle(c->u.x11.s, enable);
2101 break;
2102 }
2103 }
2104}
2105
2106/*
0405e71f 2107 * Username and password input, abstracted off into reusable
2108 * routines (hopefully even reusable between SSH1 and SSH2!).
2109 */
2110static char *ssh_userpass_input_buffer;
2111static int ssh_userpass_input_buflen;
2112static int ssh_userpass_input_bufpos;
2113static int ssh_userpass_input_echo;
2114
2115/* Set up a username or password input loop on a given buffer. */
2116void setup_userpass_input(char *buffer, int buflen, int echo)
2117{
2118 ssh_userpass_input_buffer = buffer;
2119 ssh_userpass_input_buflen = buflen;
2120 ssh_userpass_input_bufpos = 0;
2121 ssh_userpass_input_echo = echo;
2122}
2123
2124/*
2125 * Process some terminal data in the course of username/password
2126 * input. Returns >0 for success (line of input returned in
2127 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2128 * for inconclusive (keep waiting for more input please).
2129 */
2130int process_userpass_input(unsigned char *in, int inlen)
2131{
2132 char c;
2133
2134 while (inlen--) {
2135 switch (c = *in++) {
2136 case 10:
2137 case 13:
2138 ssh_userpass_input_buffer[ssh_userpass_input_bufpos] = 0;
2139 ssh_userpass_input_buffer[ssh_userpass_input_buflen-1] = 0;
2140 return +1;
2141 break;
2142 case 8:
2143 case 127:
2144 if (ssh_userpass_input_bufpos > 0) {
2145 if (ssh_userpass_input_echo)
2146 c_write_str("\b \b");
2147 ssh_userpass_input_bufpos--;
2148 }
2149 break;
2150 case 21:
2151 case 27:
2152 while (ssh_userpass_input_bufpos > 0) {
2153 if (ssh_userpass_input_echo)
2154 c_write_str("\b \b");
2155 ssh_userpass_input_bufpos--;
2156 }
2157 break;
2158 case 3:
2159 case 4:
2160 return -1;
2161 break;
2162 default:
2163 if (((c >= ' ' && c <= '~') ||
2164 ((unsigned char) c >= 160))
2165 && ssh_userpass_input_bufpos < ssh_userpass_input_buflen-1) {
2166 ssh_userpass_input_buffer[ssh_userpass_input_bufpos++] = c;
2167 if (ssh_userpass_input_echo)
2168 c_write(&c, 1);
2169 }
2170 break;
2171 }
2172 }
2173 return 0;
2174}
2175
2176/*
fb09bf1c 2177 * Handle the key exchange and user authentication phases.
2178 */
e5574168 2179static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 2180{
2d466ffd 2181 int i, j;
2182 static int len;
2183 static unsigned char *rsabuf, *keystr1, *keystr2;
374330e2 2184 unsigned char cookie[8];
2185 struct RSAKey servkey, hostkey;
2186 struct MD5Context md5c;
ccbfb941 2187 static unsigned long supported_ciphers_mask, supported_auths_mask;
67b59fbb 2188 static int tried_publickey, tried_agent;
614a20a0 2189 static int tis_auth_refused, ccard_auth_refused;
7cca0d81 2190 static unsigned char session_id[16];
2d466ffd 2191 static int cipher_type;
b585ec46 2192 static char username[100];
396778f1 2193 static void *publickey_blob;
2194 int publickey_bloblen;
374330e2 2195
374330e2 2196 crBegin;
2197
32874aea 2198 if (!ispkt)
2199 crWaitUntil(ispkt);
374330e2 2200
8d5de777 2201 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2202 bombout(("Public key packet not received"));
32874aea 2203 crReturn(0);
8d5de777 2204 }
374330e2 2205
c5e9c988 2206 logevent("Received public keys");
374330e2 2207
c5e9c988 2208 memcpy(cookie, pktin.body, 8);
374330e2 2209
32874aea 2210 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
2211 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
374330e2 2212
c5e9c988 2213 /*
1c2a93c4 2214 * Log the host key fingerprint.
c5e9c988 2215 */
c5e9c988 2216 {
2217 char logmsg[80];
1c2a93c4 2218 logevent("Host key fingerprint is:");
c5e9c988 2219 strcpy(logmsg, " ");
32874aea 2220 hostkey.comment = NULL;
2221 rsa_fingerprint(logmsg + strlen(logmsg),
2222 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2223 logevent(logmsg);
2224 }
2225
32874aea 2226 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2227 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2228 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
bea1ef5f 2229
32874aea 2230 ssh1_local_protoflags =
2231 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
b96dc54c 2232 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2233
c5e9c988 2234 MD5Init(&md5c);
374330e2 2235 MD5Update(&md5c, keystr2, hostkey.bytes);
2236 MD5Update(&md5c, keystr1, servkey.bytes);
2237 MD5Update(&md5c, pktin.body, 8);
374330e2 2238 MD5Final(session_id, &md5c);
2239
32874aea 2240 for (i = 0; i < 32; i++)
374330e2 2241 session_key[i] = random_byte();
2242
2243 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2244
dcbde236 2245 rsabuf = smalloc(len);
374330e2 2246 if (!rsabuf)
2247 fatalbox("Out of memory");
2248
89ee5268 2249 /*
2250 * Verify the host key.
2251 */
2252 {
32874aea 2253 /*
2254 * First format the key into a string.
2255 */
2256 int len = rsastr_len(&hostkey);
2257 char fingerprint[100];
2258 char *keystr = smalloc(len);
2259 if (!keystr)
2260 fatalbox("Out of memory");
2261 rsastr_fmt(keystr, &hostkey);
2262 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2263 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2264 fingerprint);
2265 sfree(keystr);
2266 }
2267
2268 for (i = 0; i < 32; i++) {
374330e2 2269 rsabuf[i] = session_key[i];
2270 if (i < 16)
2271 rsabuf[i] ^= session_id[i];
2272 }
2273
2274 if (hostkey.bytes > servkey.bytes) {
2275 rsaencrypt(rsabuf, 32, &servkey);
2276 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2277 } else {
2278 rsaencrypt(rsabuf, 32, &hostkey);
2279 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2280 }
2281
c5e9c988 2282 logevent("Encrypted session key");
2283
ca20bfcf 2284 {
2285 int cipher_chosen = 0, warn = 0;
2286 char *cipher_string = NULL;
2287 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2288 int next_cipher = cfg.ssh_cipherlist[i];
2289 if (next_cipher == CIPHER_WARN) {
2290 /* If/when we choose a cipher, warn about it */
2291 warn = 1;
2292 } else if (next_cipher == CIPHER_AES) {
2293 /* XXX Probably don't need to mention this. */
2294 logevent("AES not supported in SSH1, skipping");
2295 } else {
2296 switch (next_cipher) {
2297 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2298 cipher_string = "3DES"; break;
2299 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2300 cipher_string = "Blowfish"; break;
2301 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2302 cipher_string = "single-DES"; break;
2303 }
2304 if (supported_ciphers_mask & (1 << cipher_type))
2305 cipher_chosen = 1;
2306 }
2307 }
2308 if (!cipher_chosen) {
2309 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2310 bombout(("Server violates SSH 1 protocol by not "
2311 "supporting 3DES encryption"));
2312 else
2313 /* shouldn't happen */
2314 bombout(("No supported ciphers found"));
a99a05c0 2315 crReturn(0);
2316 }
ca20bfcf 2317
2318 /* Warn about chosen cipher if necessary. */
2319 if (warn)
2320 askcipher(cipher_string, 0);
bea1ef5f 2321 }
ca20bfcf 2322
c5e9c988 2323 switch (cipher_type) {
32874aea 2324 case SSH_CIPHER_3DES:
2325 logevent("Using 3DES encryption");
2326 break;
2327 case SSH_CIPHER_DES:
2328 logevent("Using single-DES encryption");
2329 break;
2330 case SSH_CIPHER_BLOWFISH:
2331 logevent("Using Blowfish encryption");
2332 break;
c5e9c988 2333 }
bea1ef5f 2334
e5574168 2335 send_packet(SSH1_CMSG_SESSION_KEY,
32874aea 2336 PKT_CHAR, cipher_type,
2337 PKT_DATA, cookie, 8,
2338 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2339 PKT_DATA, rsabuf, len,
2340 PKT_INT, ssh1_local_protoflags, PKT_END);
fb09bf1c 2341
c5e9c988 2342 logevent("Trying to enable encryption...");
374330e2 2343
dcbde236 2344 sfree(rsabuf);
374330e2 2345
5e8358ad 2346 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
32874aea 2347 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
374330e2 2348 cipher->sesskey(session_key);
2349
fb09bf1c 2350 crWaitUntil(ispkt);
374330e2 2351
8d5de777 2352 if (pktin.type != SSH1_SMSG_SUCCESS) {
2353 bombout(("Encryption not successfully enabled"));
32874aea 2354 crReturn(0);
8d5de777 2355 }
374330e2 2356
c5e9c988 2357 logevent("Successfully started encryption");
2358
374330e2 2359 fflush(stdout);
2360 {
67779be7 2361 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 2362 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2363 if (!ssh_get_line("login as: ",
2364 username, sizeof(username), FALSE)) {
2365 /*
2366 * get_line failed to get a username.
2367 * Terminate.
2368 */
2369 logevent("No username provided. Abandoning session.");
2370 ssh_state = SSH_STATE_CLOSED;
2371 crReturn(1);
2372 }
2373 } else {
0405e71f 2374 static int ret;
32874aea 2375 c_write_str("login as: ");
2376 ssh_send_ok = 1;
0405e71f 2377
2378 setup_userpass_input(username, sizeof(username), 1);
2379 do {
32874aea 2380 crWaitUntil(!ispkt);
0405e71f 2381 ret = process_userpass_input(in, inlen);
2382 } while (ret == 0);
2383 if (ret < 0)
2384 cleanup_exit(0);
32874aea 2385 c_write_str("\r\n");
32874aea 2386 }
2387 } else {
277fc55e 2388 strncpy(username, cfg.username, sizeof(username));
2389 username[sizeof(username)-1] = '\0';
374330e2 2390 }
fb09bf1c 2391
e5574168 2392 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 2393 {
32874aea 2394 char userlog[22 + sizeof(username)];
c5e9c988 2395 sprintf(userlog, "Sent username \"%s\"", username);
2396 logevent(userlog);
32874aea 2397 if (flags & FLAG_INTERACTIVE &&
2398 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2399 strcat(userlog, "\r\n");
32874aea 2400 c_write_str(userlog);
3c8e959b 2401 }
c5e9c988 2402 }
374330e2 2403 }
2404
fb09bf1c 2405 crWaitUntil(ispkt);
374330e2 2406
0df73905 2407 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2408 /* We must not attempt PK auth. Pretend we've already tried it. */
2409 tried_publickey = tried_agent = 1;
2410 } else {
2411 tried_publickey = tried_agent = 0;
2412 }
614a20a0 2413 tis_auth_refused = ccard_auth_refused = 0;
396778f1 2414 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2415 if (*cfg.keyfile) {
2416 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2417 publickey_blob = NULL;
2418 } else
2419 publickey_blob = NULL;
7cca0d81 2420
e5574168 2421 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 2422 static char password[100];
a52f067e 2423 static char prompt[200];
374330e2 2424 static int pos;
2425 static char c;
32874aea 2426 static int pwpkt_type;
32874aea 2427 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2428
67b59fbb 2429 if (agent_exists() && !tried_agent) {
32874aea 2430 /*
2431 * Attempt RSA authentication using Pageant.
2432 */
2433 static unsigned char request[5], *response, *p;
2434 static int responselen;
2435 static int i, nkeys;
2436 static int authed = FALSE;
2437 void *r;
2438
67b59fbb 2439 tried_agent = 1;
32874aea 2440 logevent("Pageant is running. Requesting keys.");
2441
2442 /* Request the keys held by the agent. */
2443 PUT_32BIT(request, 1);
2444 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2445 agent_query(request, 5, &r, &responselen);
2446 response = (unsigned char *) r;
2447 if (response && responselen >= 5 &&
2448 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2449 p = response + 5;
2450 nkeys = GET_32BIT(p);
2451 p += 4;
2452 {
2453 char buf[64];
2454 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2455 logevent(buf);
2456 }
2457 for (i = 0; i < nkeys; i++) {
2458 static struct RSAKey key;
2459 static Bignum challenge;
2460 static char *commentp;
2461 static int commentlen;
2462
2463 {
2464 char buf[64];
2465 sprintf(buf, "Trying Pageant key #%d", i);
2466 logevent(buf);
2467 }
396778f1 2468 if (publickey_blob &&
2469 !memcmp(p, publickey_blob, publickey_bloblen)) {
2470 logevent("This key matches configured key file");
2471 tried_publickey = 1;
2472 }
32874aea 2473 p += 4;
2474 p += ssh1_read_bignum(p, &key.exponent);
2475 p += ssh1_read_bignum(p, &key.modulus);
2476 commentlen = GET_32BIT(p);
2477 p += 4;
2478 commentp = p;
2479 p += commentlen;
2480 send_packet(SSH1_CMSG_AUTH_RSA,
2481 PKT_BIGNUM, key.modulus, PKT_END);
2482 crWaitUntil(ispkt);
2483 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2484 logevent("Key refused");
2485 continue;
2486 }
2487 logevent("Received RSA challenge");
2488 ssh1_read_bignum(pktin.body, &challenge);
2489 {
2490 char *agentreq, *q, *ret;
2d466ffd 2491 void *vret;
32874aea 2492 int len, retlen;
2493 len = 1 + 4; /* message type, bit count */
2494 len += ssh1_bignum_length(key.exponent);
2495 len += ssh1_bignum_length(key.modulus);
2496 len += ssh1_bignum_length(challenge);
2497 len += 16; /* session id */
2498 len += 4; /* response format */
2499 agentreq = smalloc(4 + len);
2500 PUT_32BIT(agentreq, len);
2501 q = agentreq + 4;
2502 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2503 PUT_32BIT(q, bignum_bitcount(key.modulus));
2504 q += 4;
2505 q += ssh1_write_bignum(q, key.exponent);
2506 q += ssh1_write_bignum(q, key.modulus);
2507 q += ssh1_write_bignum(q, challenge);
2508 memcpy(q, session_id, 16);
2509 q += 16;
2510 PUT_32BIT(q, 1); /* response format */
2d466ffd 2511 agent_query(agentreq, len + 4, &vret, &retlen);
2512 ret = vret;
32874aea 2513 sfree(agentreq);
2514 if (ret) {
2515 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2516 logevent("Sending Pageant's response");
2517 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2518 PKT_DATA, ret + 5, 16,
2519 PKT_END);
2520 sfree(ret);
2521 crWaitUntil(ispkt);
2522 if (pktin.type == SSH1_SMSG_SUCCESS) {
2523 logevent
2524 ("Pageant's response accepted");
2525 if (flags & FLAG_VERBOSE) {
2526 c_write_str
2527 ("Authenticated using RSA key \"");
2528 c_write(commentp, commentlen);
2529 c_write_str("\" from agent\r\n");
2530 }
2531 authed = TRUE;
2532 } else
2533 logevent
2534 ("Pageant's response not accepted");
2535 } else {
2536 logevent
2537 ("Pageant failed to answer challenge");
2538 sfree(ret);
2539 }
2540 } else {
2541 logevent("No reply received from Pageant");
2542 }
2543 }
2544 freebn(key.exponent);
2545 freebn(key.modulus);
2546 freebn(challenge);
2547 if (authed)
2548 break;
2549 }
2550 }
2551 if (authed)
2552 break;
2553 }
2554 if (*cfg.keyfile && !tried_publickey)
2555 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2556
614a20a0 2557 if (cfg.try_tis_auth &&
2558 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2559 !tis_auth_refused) {
32874aea 2560 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2561 logevent("Requested TIS authentication");
2562 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2563 crWaitUntil(ispkt);
2564 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2565 logevent("TIS authentication declined");
2566 if (flags & FLAG_INTERACTIVE)
2567 c_write_str("TIS authentication refused.\r\n");
614a20a0 2568 tis_auth_refused = 1;
2569 continue;
32874aea 2570 } else {
2571 int challengelen = ((pktin.body[0] << 24) |
2572 (pktin.body[1] << 16) |
2573 (pktin.body[2] << 8) |
2574 (pktin.body[3]));
2575 logevent("Received TIS challenge");
2576 if (challengelen > sizeof(prompt) - 1)
2577 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2578 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2579 /* Prompt heuristic comes from OpenSSH */
2580 strncpy(prompt + challengelen,
2581 memchr(prompt, '\n', challengelen) ?
2582 "": "\r\nResponse: ",
2583 (sizeof prompt) - challengelen);
2584 prompt[(sizeof prompt) - 1] = '\0';
32874aea 2585 }
2586 }
614a20a0 2587 if (cfg.try_tis_auth &&
2588 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2589 !ccard_auth_refused) {
32874aea 2590 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2591 logevent("Requested CryptoCard authentication");
2592 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2593 crWaitUntil(ispkt);
2594 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2595 logevent("CryptoCard authentication declined");
2596 c_write_str("CryptoCard authentication refused.\r\n");
614a20a0 2597 ccard_auth_refused = 1;
2598 continue;
32874aea 2599 } else {
2600 int challengelen = ((pktin.body[0] << 24) |
2601 (pktin.body[1] << 16) |
2602 (pktin.body[2] << 8) |
2603 (pktin.body[3]));
2604 logevent("Received CryptoCard challenge");
2605 if (challengelen > sizeof(prompt) - 1)
2606 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2607 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2608 strncpy(prompt + challengelen,
2609 memchr(prompt, '\n', challengelen) ?
2610 "" : "\r\nResponse: ",
32874aea 2611 sizeof(prompt) - challengelen);
2612 prompt[sizeof(prompt) - 1] = '\0';
2613 }
2614 }
2615 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2616 sprintf(prompt, "%.90s@%.90s's password: ",
2617 username, savedhost);
2618 }
2619 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2620 char *comment = NULL;
231ee168 2621 int type;
2622 char msgbuf[256];
32874aea 2623 if (flags & FLAG_VERBOSE)
2624 c_write_str("Trying public key authentication.\r\n");
231ee168 2625 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2626 logevent(msgbuf);
2627 type = key_type(cfg.keyfile);
2628 if (type != SSH_KEYTYPE_SSH1) {
2629 sprintf(msgbuf, "Key is of wrong type (%s)",
2630 key_type_to_str(type));
2631 logevent(msgbuf);
2632 c_write_str(msgbuf);
2633 c_write_str("\r\n");
2634 tried_publickey = 1;
2635 continue;
2636 }
32874aea 2637 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2638 if (flags & FLAG_VERBOSE)
2639 c_write_str("No passphrase required.\r\n");
2640 goto tryauth;
2641 }
2642 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2643 sfree(comment);
2644 }
a52f067e 2645
614a20a0 2646 /*
2647 * Show password prompt, having first obtained it via a TIS
2648 * or CryptoCard exchange if we're doing TIS or CryptoCard
2649 * authentication.
2650 */
fa17a66e 2651 if (ssh_get_line) {
2652 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
32874aea 2653 /*
2654 * get_line failed to get a password (for example
2655 * because one was supplied on the command line
2656 * which has already failed to work). Terminate.
2657 */
2bc6a386 2658 send_packet(SSH1_MSG_DISCONNECT,
2659 PKT_STR, "No more passwords available to try",
2660 PKT_END);
247308b5 2661 logevent("Unable to authenticate");
2bc6a386 2662 connection_fatal("Unable to authenticate");
32874aea 2663 ssh_state = SSH_STATE_CLOSED;
2664 crReturn(1);
2665 }
fb09bf1c 2666 } else {
614a20a0 2667 /* Prompt may have come from server. We've munged it a bit, so
2668 * we know it to be zero-terminated at least once. */
0405e71f 2669 static int ret;
614a20a0 2670 c_write_untrusted(prompt, strlen(prompt));
32874aea 2671 pos = 0;
0405e71f 2672
2673 setup_userpass_input(password, sizeof(password), 0);
2674 do {
32874aea 2675 crWaitUntil(!ispkt);
0405e71f 2676 ret = process_userpass_input(in, inlen);
2677 } while (ret == 0);
2678 if (ret < 0)
2679 cleanup_exit(0);
32874aea 2680 c_write_str("\r\n");
2681 }
2682
2683 tryauth:
7cca0d81 2684 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2685 /*
2686 * Try public key authentication with the specified
2687 * key file.
2688 */
2689 static struct RSAKey pubkey;
2690 static Bignum challenge, response;
2691 static int i;
2692 static unsigned char buffer[32];
2693
2694 tried_publickey = 1;
2695 i = loadrsakey(cfg.keyfile, &pubkey, password);
2696 if (i == 0) {
7963af2f 2697 c_write_str("Couldn't load private key from ");
32874aea 2698 c_write_str(cfg.keyfile);
2699 c_write_str(".\r\n");
2700 continue; /* go and try password */
2701 }
2702 if (i == -1) {
2703 c_write_str("Wrong passphrase.\r\n");
2704 tried_publickey = 0;
2705 continue; /* try again */
2706 }
2707
2708 /*
2709 * Send a public key attempt.
2710 */
2711 send_packet(SSH1_CMSG_AUTH_RSA,
2712 PKT_BIGNUM, pubkey.modulus, PKT_END);
2713
2714 crWaitUntil(ispkt);
2715 if (pktin.type == SSH1_SMSG_FAILURE) {
2716 c_write_str("Server refused our public key.\r\n");
2717 continue; /* go and try password */
2718 }
2719 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2720 bombout(("Bizarre response to offer of public key"));
2721 crReturn(0);
2722 }
2723 ssh1_read_bignum(pktin.body, &challenge);
2724 response = rsadecrypt(challenge, &pubkey);
2725 freebn(pubkey.private_exponent); /* burn the evidence */
2726
2727 for (i = 0; i < 32; i++) {
2728 buffer[i] = bignum_byte(response, 31 - i);
2729 }
2730
2731 MD5Init(&md5c);
2732 MD5Update(&md5c, buffer, 32);
2733 MD5Update(&md5c, session_id, 16);
2734 MD5Final(buffer, &md5c);
2735
2736 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2737 PKT_DATA, buffer, 16, PKT_END);
2738
2739 crWaitUntil(ispkt);
2740 if (pktin.type == SSH1_SMSG_FAILURE) {
2741 if (flags & FLAG_VERBOSE)
2742 c_write_str
2743 ("Failed to authenticate with our public key.\r\n");
2744 continue; /* go and try password */
2745 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2746 bombout(
2747 ("Bizarre response to RSA authentication response"));
2748 crReturn(0);
2749 }
2750
2751 break; /* we're through! */
2752 } else {
2753 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2754 /*
2755 * Defence against traffic analysis: we send a
2756 * whole bunch of packets containing strings of
2757 * different lengths. One of these strings is the
2758 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2759 * The others are all random data in
2760 * SSH1_MSG_IGNORE packets. This way a passive
2761 * listener can't tell which is the password, and
2762 * hence can't deduce the password length.
2763 *
2764 * Anybody with a password length greater than 16
2765 * bytes is going to have enough entropy in their
2766 * password that a listener won't find it _that_
2767 * much help to know how long it is. So what we'll
2768 * do is:
2769 *
2770 * - if password length < 16, we send 15 packets
2771 * containing string lengths 1 through 15
2772 *
2773 * - otherwise, we let N be the nearest multiple
2774 * of 8 below the password length, and send 8
2775 * packets containing string lengths N through
2776 * N+7. This won't obscure the order of
2777 * magnitude of the password length, but it will
2778 * introduce a bit of extra uncertainty.
2779 *
2780 * A few servers (the old 1.2.18 through 1.2.22)
2781 * can't deal with SSH1_MSG_IGNORE. For these
2782 * servers, we need an alternative defence. We make
2783 * use of the fact that the password is interpreted
2784 * as a C string: so we can append a NUL, then some
2785 * random data.
bd358db1 2786 *
2787 * One server (a Cisco one) can deal with neither
2788 * SSH1_MSG_IGNORE _nor_ a padded password string.
2789 * For this server we are left with no defences
2790 * against password length sniffing.
32874aea 2791 */
bd358db1 2792 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2793 /*
2794 * The server can deal with SSH1_MSG_IGNORE, so
2795 * we can use the primary defence.
2796 */
32874aea 2797 int bottom, top, pwlen, i;
2798 char *randomstr;
2799
2800 pwlen = strlen(password);
2801 if (pwlen < 16) {
2802 bottom = 0; /* zero length passwords are OK! :-) */
2803 top = 15;
2804 } else {
2805 bottom = pwlen & ~7;
2806 top = bottom + 7;
2807 }
2808
2809 assert(pwlen >= bottom && pwlen <= top);
2810
2811 randomstr = smalloc(top + 1);
2812
2813 for (i = bottom; i <= top; i++) {
2814 if (i == pwlen)
2815 defer_packet(pwpkt_type, PKT_STR, password,
2816 PKT_END);
2817 else {
2818 for (j = 0; j < i; j++) {
2819 do {
2820 randomstr[j] = random_byte();
2821 } while (randomstr[j] == '\0');
2822 }
2823 randomstr[i] = '\0';
2824 defer_packet(SSH1_MSG_IGNORE,
2825 PKT_STR, randomstr, PKT_END);
2826 }
2827 }
bd358db1 2828 logevent("Sending password with camouflage packets");
32874aea 2829 ssh_pkt_defersend();
bd358db1 2830 }
2831 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2832 /*
2833 * The server can't deal with SSH1_MSG_IGNORE
2834 * but can deal with padded passwords, so we
2835 * can use the secondary defence.
2836 */
bd358db1 2837 char string[64];
2838 char *s;
2839 int len;
2840
2841 len = strlen(password);
2842 if (len < sizeof(string)) {
2843 s = string;
2844 strcpy(string, password);
2845 len++; /* cover the zero byte */
2846 while (len < sizeof(string)) {
2847 string[len++] = (char) random_byte();
2848 }
2849 } else {
2850 s = password;
2851 }
2852 logevent("Sending length-padded password");
2853 send_packet(pwpkt_type, PKT_INT, len,
2854 PKT_DATA, s, len, PKT_END);
2855 } else {
2856 /*
2857 * The server has _both_
2858 * BUG_CHOKES_ON_SSH1_IGNORE and
2859 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2860 * therefore nothing we can do.
2861 */
2862 int len;
2863 len = strlen(password);
2864 logevent("Sending unpadded password");
2865 send_packet(pwpkt_type, PKT_INT, len,
2866 PKT_DATA, password, len, PKT_END);
32874aea 2867 }
2868 } else {
2869 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2870 }
2871 }
c5e9c988 2872 logevent("Sent password");
374330e2 2873 memset(password, 0, strlen(password));
fb09bf1c 2874 crWaitUntil(ispkt);
e5574168 2875 if (pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2876 if (flags & FLAG_VERBOSE)
2877 c_write_str("Access denied\r\n");
c5e9c988 2878 logevent("Authentication refused");
e5574168 2879 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2880 logevent("Received disconnect request");
32874aea 2881 ssh_state = SSH_STATE_CLOSED;
85ee8208 2882 crReturn(1);
e5574168 2883 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2884 bombout(("Strange packet received, type %d", pktin.type));
32874aea 2885 crReturn(0);
374330e2 2886 }
2887 }
2888
c5e9c988 2889 logevent("Authentication successful");
2890
fb09bf1c 2891 crFinish(1);
2892}
2893
32874aea 2894void sshfwd_close(struct ssh_channel *c)
2895{
80e48603 2896 if (c && !c->closes) {
4ed34d25 2897 /*
2898 * If the channel's remoteid is -1, we have sent
2899 * CHANNEL_OPEN for this channel, but it hasn't even been
2900 * acknowledged by the server. So we must set a close flag
2901 * on it now, and then when the server acks the channel
2902 * open, we can close it then.
2903 */
36cac739 2904 if (((int)c->remoteid) != -1) {
4ed34d25 2905 if (ssh_version == 1) {
2906 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2907 PKT_END);
2908 } else {
2909 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2910 ssh2_pkt_adduint32(c->remoteid);
2911 ssh2_pkt_send();
2912 }
32874aea 2913 }
0357890f 2914 c->closes = 1; /* sent MSG_CLOSE */
32874aea 2915 if (c->type == CHAN_X11) {
2916 c->u.x11.s = NULL;
d74d141c 2917 logevent("Forwarded X11 connection terminated");
4ed34d25 2918 } else if (c->type == CHAN_SOCKDATA ||
2919 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2920 c->u.pfd.s = NULL;
2921 logevent("Forwarded port closed");
32874aea 2922 }
2923 }
2924}
2925
5471d09a 2926int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2927{
783415f8 2928 if (ssh_version == 1) {
32874aea 2929 send_packet(SSH1_MSG_CHANNEL_DATA,
2930 PKT_INT, c->remoteid,
2931 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2932 /*
2933 * In SSH1 we can return 0 here - implying that forwarded
2934 * connections are never individually throttled - because
2935 * the only circumstance that can cause throttling will be
2936 * the whole SSH connection backing up, in which case
2937 * _everything_ will be throttled as a whole.
2938 */
2939 return 0;
783415f8 2940 } else {
32874aea 2941 ssh2_add_channel_data(c, buf, len);
5471d09a 2942 return ssh2_try_send(c);
2943 }
2944}
2945
2946void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2947{
2948 if (ssh_version == 1) {
2949 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2950 c->v.v1.throttling = 0;
2951 ssh1_throttle(-1);
2952 }
2953 } else {
2954 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2955 }
9c964e85 2956}
2957
32874aea 2958static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2959{
fb09bf1c 2960 crBegin;
2961
2962 random_init();
2963
e5574168 2964 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2965 crReturnV;
85ee8208 2966 }
2967 if (ssh_state == SSH_STATE_CLOSED)
32874aea 2968 crReturnV;
fb09bf1c 2969
979310f1 2970 if (cfg.agentfwd && agent_exists()) {
32874aea 2971 logevent("Requesting agent forwarding");
2972 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2973 do {
2974 crReturnV;
2975 } while (!ispkt);
2976 if (pktin.type != SSH1_SMSG_SUCCESS
2977 && pktin.type != SSH1_SMSG_FAILURE) {
2978 bombout(("Protocol confusion"));
2979 crReturnV;
2980 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2981 logevent("Agent forwarding refused");
2982 } else {
2983 logevent("Agent forwarding enabled");
db7d555c 2984 ssh_agentfwd_enabled = TRUE;
2985 }
dacbd0e8 2986 }
2987
9c964e85 2988 if (cfg.x11_forward) {
32874aea 2989 char proto[20], data[64];
2990 logevent("Requesting X11 forwarding");
2991 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2992 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2993 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2994 PKT_STR, proto, PKT_STR, data,
2995 PKT_INT, 0, PKT_END);
2996 } else {
2997 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2998 PKT_STR, proto, PKT_STR, data, PKT_END);
2999 }
3000 do {
3001 crReturnV;
3002 } while (!ispkt);
3003 if (pktin.type != SSH1_SMSG_SUCCESS
3004 && pktin.type != SSH1_SMSG_FAILURE) {
3005 bombout(("Protocol confusion"));
3006 crReturnV;
3007 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3008 logevent("X11 forwarding refused");
3009 } else {
3010 logevent("X11 forwarding enabled");
9c964e85 3011 ssh_X11_fwd_enabled = TRUE;
3012 }
3013 }
3014
d74d141c 3015 {
9bf696b1 3016 char type;
3017 static char *e;
d74d141c 3018 int n;
a4fc0d74 3019 int sport,dport,sserv,dserv;
d74d141c 3020 char sports[256], dports[256], host[256];
3021 char buf[1024];
a4fc0d74 3022 struct servent *se;
d74d141c 3023
bc240b21 3024 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3025 /* Add port forwardings. */
3026 e = cfg.portfwd;
3027 while (*e) {
3028 type = *e++;
3029 n = 0;
3030 while (*e && *e != '\t')
3031 sports[n++] = *e++;
3032 sports[n] = 0;
3033 if (*e == '\t')
3034 e++;
3035 n = 0;
3036 while (*e && *e != ':')
3037 host[n++] = *e++;
3038 host[n] = 0;
3039 if (*e == ':')
3040 e++;
3041 n = 0;
3042 while (*e)
3043 dports[n++] = *e++;
3044 dports[n] = 0;
3045 e++;
3046 dport = atoi(dports);
a4fc0d74 3047 dserv = 0;
3048 if (dport == 0) {
3049 dserv = 1;
3050 se = getservbyname(dports, NULL);
3051 if (se != NULL) {
3052 dport = ntohs(se->s_port);
3053 } else {
3054 sprintf(buf,
3055 "Service lookup failed for destination port \"%s\"",
3056 dports);
3057 logevent(buf);
3058 }
3059 }
d74d141c 3060 sport = atoi(sports);
a4fc0d74 3061 sserv = 0;
3062 if (sport == 0) {
3063 sserv = 1;
3064 se = getservbyname(sports, NULL);
3065 if (se != NULL) {
3066 sport = ntohs(se->s_port);
3067 } else {
3068 sprintf(buf,
3069 "Service lookup failed for source port \"%s\"",
3070 sports);
3071 logevent(buf);
3072 }
3073 }
d74d141c 3074 if (sport && dport) {
3075 if (type == 'L') {
3076 pfd_addforward(host, dport, sport);
a4fc0d74 3077 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3078 " %s:%.*s%.*s%d%.*s",
3079 sserv ? strlen(sports) : 0, sports,
3080 sserv, "(", sport, sserv, ")",
3081 host,
3082 dserv ? strlen(dports) : 0, dports,
3083 dserv, "(", dport, dserv, ")");
d74d141c 3084 logevent(buf);
3085 } else {
3086 struct ssh_rportfwd *pf;
3087 pf = smalloc(sizeof(*pf));
bc240b21 3088 strcpy(pf->dhost, host);
3089 pf->dport = dport;
d74d141c 3090 if (add234(ssh_rportfwds, pf) != pf) {
3091 sprintf(buf,
95bc8819 3092 "Duplicate remote port forwarding to %s:%d",
d74d141c 3093 host, dport);
3094 logevent(buf);
bc240b21 3095 sfree(pf);
d74d141c 3096 } else {
a4fc0d74 3097 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3098 " forward to %s:%.*s%.*s%d%.*s",
3099 sserv ? strlen(sports) : 0, sports,
3100 sserv, "(", sport, sserv, ")",
3101 host,
3102 dserv ? strlen(dports) : 0, dports,
3103 dserv, "(", dport, dserv, ")");
d74d141c 3104 logevent(buf);
3105 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
3106 PKT_INT, sport,
3107 PKT_STR, host,
3108 PKT_INT, dport,
3109 PKT_END);
9bf696b1 3110 do {
3111 crReturnV;
3112 } while (!ispkt);
3113 if (pktin.type != SSH1_SMSG_SUCCESS
3114 && pktin.type != SSH1_SMSG_FAILURE) {
3115 bombout(("Protocol confusion"));
3116 crReturnV;
3117 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3118 c_write_str("Server refused port forwarding\r\n");
3119 ssh_editing = ssh_echoing = 1;
3120 }
3121 logevent("Remote port forwarding enabled");
d74d141c 3122 }
3123 }
3124 }
3125 }
3126 }
3127
fef97f43 3128 if (!cfg.nopty) {
e5574168 3129 send_packet(SSH1_CMSG_REQUEST_PTY,
32874aea 3130 PKT_STR, cfg.termtype,
f278d6f8 3131 PKT_INT, ssh_term_height,
3132 PKT_INT, ssh_term_width,
32874aea 3133 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3134 ssh_state = SSH_STATE_INTERMED;
3135 do {
3136 crReturnV;
3137 } while (!ispkt);
3138 if (pktin.type != SSH1_SMSG_SUCCESS
3139 && pktin.type != SSH1_SMSG_FAILURE) {
3140 bombout(("Protocol confusion"));
3141 crReturnV;
3142 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3143 c_write_str("Server refused to allocate pty\r\n");
3144 ssh_editing = ssh_echoing = 1;
3145 }
c5e9c988 3146 logevent("Allocated pty");
0965bee0 3147 } else {
32874aea 3148 ssh_editing = ssh_echoing = 1;
374330e2 3149 }
3150
4ba9b64b 3151 if (cfg.compression) {
32874aea 3152 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3153 do {
3154 crReturnV;
3155 } while (!ispkt);
3156 if (pktin.type != SSH1_SMSG_SUCCESS
3157 && pktin.type != SSH1_SMSG_FAILURE) {
3158 bombout(("Protocol confusion"));
3159 crReturnV;
3160 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3161 c_write_str("Server refused to compress\r\n");
3162 }
4ba9b64b 3163 logevent("Started compression");
3164 ssh1_compressing = TRUE;
3165 zlib_compress_init();
3166 zlib_decompress_init();
3167 }
3168
fd5e5847 3169 /*
3170 * Start the shell or command.
3171 *
3172 * Special case: if the first-choice command is an SSH2
3173 * subsystem (hence not usable here) and the second choice
3174 * exists, we fall straight back to that.
3175 */
3176 {
3177 char *cmd = cfg.remote_cmd_ptr;
3178
3179 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3180 cmd = cfg.remote_cmd_ptr2;
3181 ssh_fallback_cmd = TRUE;
3182 }
3183 if (*cmd)
3184 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3185 else
3186 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3187 logevent("Started session");
3188 }
374330e2 3189
3190 ssh_state = SSH_STATE_SESSION;
3191 if (size_needed)
818ab3bb 3192 ssh_size(ssh_term_width, ssh_term_height);
3687d221 3193 if (eof_needed)
32874aea 3194 ssh_special(TS_EOF);
374330e2 3195
760e88b2 3196 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 3197 ssh_send_ok = 1;
dacbd0e8 3198 ssh_channels = newtree234(ssh_channelcmp);
374330e2 3199 while (1) {
3200 crReturnV;
3201 if (ispkt) {
e5574168 3202 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 3203 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 3204 long len = GET_32BIT(pktin.body);
5471d09a 3205 int bufsize =
887035a5 3206 from_backend(frontend, pktin.type == SSH1_SMSG_STDERR_DATA,
5471d09a 3207 pktin.body + 4, len);
90347b95 3208 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3209 ssh1_stdout_throttling = 1;
3210 ssh1_throttle(+1);
3211 }
e5574168 3212 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
32874aea 3213 ssh_state = SSH_STATE_CLOSED;
c5e9c988 3214 logevent("Received disconnect request");
32874aea 3215 crReturnV;
3216 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3217 /* Remote side is trying to open a channel to talk to our
3218 * X-Server. Give them back a local channel number. */
3219 struct ssh_channel *c;
9c964e85 3220
3221 logevent("Received X11 connect request");
3222 /* Refuse if X11 forwarding is disabled. */
3223 if (!ssh_X11_fwd_enabled) {
3224 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 3225 PKT_INT, GET_32BIT(pktin.body), PKT_END);
9c964e85 3226 logevent("Rejected X11 connect request");
3227 } else {
9c964e85 3228 c = smalloc(sizeof(struct ssh_channel));
3229
32874aea 3230 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3231 logevent("opening X11 forward connection failed");
3232 sfree(c);
3233 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3234 PKT_INT, GET_32BIT(pktin.body),
3235 PKT_END);
9c964e85 3236 } else {
32874aea 3237 logevent
3238 ("opening X11 forward connection succeeded");
3239 c->remoteid = GET_32BIT(pktin.body);
3240 c->localid = alloc_channel_id();
3241 c->closes = 0;
5471d09a 3242 c->v.v1.throttling = 0;
32874aea 3243 c->type = CHAN_X11; /* identify channel type */
3244 add234(ssh_channels, c);
3245 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3246 PKT_INT, c->remoteid, PKT_INT,
3247 c->localid, PKT_END);
3248 logevent("Opened X11 forward channel");
9c964e85 3249 }
3250 }
32874aea 3251 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3252 /* Remote side is trying to open a channel to talk to our
3253 * agent. Give them back a local channel number. */
3254 struct ssh_channel *c;
db7d555c 3255
3256 /* Refuse if agent forwarding is disabled. */
3257 if (!ssh_agentfwd_enabled) {
3258 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 3259 PKT_INT, GET_32BIT(pktin.body), PKT_END);
db7d555c 3260 } else {
dcbde236 3261 c = smalloc(sizeof(struct ssh_channel));
db7d555c 3262 c->remoteid = GET_32BIT(pktin.body);
d2371c81 3263 c->localid = alloc_channel_id();
db7d555c 3264 c->closes = 0;
5471d09a 3265 c->v.v1.throttling = 0;
32874aea 3266 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3267 c->u.a.lensofar = 0;
3268 add234(ssh_channels, c);
3269 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3270 PKT_INT, c->remoteid, PKT_INT, c->localid,
3271 PKT_END);
3272 }
d74d141c 3273 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3274 /* Remote side is trying to open a channel to talk to a
3275 * forwarded port. Give them back a local channel number. */
3276 struct ssh_channel *c;
3277 struct ssh_rportfwd pf;
3278 int hostsize, port;
3279 char host[256], buf[1024];
3280 char *p, *h, *e;
3281 c = smalloc(sizeof(struct ssh_channel));
3282
3283 hostsize = GET_32BIT(pktin.body+4);
3284 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3285 if (h+1 < host+sizeof(host))
3286 *h++ = *p;
95bc8819 3287 p++;
d74d141c 3288 }
3289 *h = 0;
3290 port = GET_32BIT(p);
3291
bc240b21 3292 strcpy(pf.dhost, host);
3293 pf.dport = port;
d74d141c 3294
3295 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3296 sprintf(buf, "Rejected remote port open request for %s:%d",
3297 host, port);
3298 logevent(buf);
3299 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3300 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3301 } else {
3302 sprintf(buf, "Received remote port open request for %s:%d",
3303 host, port);
3304 logevent(buf);
3305 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3306 if (e != NULL) {
3307 char buf[256];
3308 sprintf(buf, "Port open failed: %s", e);
3309 logevent(buf);
3310 sfree(c);
3311 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3312 PKT_INT, GET_32BIT(pktin.body),
3313 PKT_END);
3314 } else {
3315 c->remoteid = GET_32BIT(pktin.body);
3316 c->localid = alloc_channel_id();
3317 c->closes = 0;
5471d09a 3318 c->v.v1.throttling = 0;
d74d141c 3319 c->type = CHAN_SOCKDATA; /* identify channel type */
3320 add234(ssh_channels, c);
3321 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3322 PKT_INT, c->remoteid, PKT_INT,
3323 c->localid, PKT_END);
3324 logevent("Forwarded port opened successfully");
3325 }
3326 }
3327
3328 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
bc240b21 3329 unsigned int remoteid = GET_32BIT(pktin.body);
3330 unsigned int localid = GET_32BIT(pktin.body+4);
3331 struct ssh_channel *c;
3332
3333 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3334 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3335 c->remoteid = localid;
3336 c->type = CHAN_SOCKDATA;
7781f316 3337 c->v.v1.throttling = 0;
bc240b21 3338 pfd_confirm(c->u.pfd.s);
3339 }
d74d141c 3340
4ed34d25 3341 if (c && c->closes) {
3342 /*
3343 * We have a pending close on this channel,
3344 * which we decided on before the server acked
3345 * the channel open. So now we know the
3346 * remoteid, we can close it again.
3347 */
3348 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3349 PKT_END);
3350 }
3351
724cface 3352 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3353 unsigned int remoteid = GET_32BIT(pktin.body);
3354 unsigned int localid = GET_32BIT(pktin.body+4);
3355 struct ssh_channel *c;
3356
3357 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3358 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3359 logevent("Forwarded connection refused by server");
3360 pfd_close(c->u.pfd.s);
3361 del234(ssh_channels, c);
3362 sfree(c);
3363 }
3364
db7d555c 3365 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3366 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3367 /* Remote side closes a channel. */
3368 unsigned i = GET_32BIT(pktin.body);
3369 struct ssh_channel *c;
3370 c = find234(ssh_channels, &i, ssh_channelfind);
d0d844c1 3371 if (c && ((int)c->remoteid) != -1) {
32874aea 3372 int closetype;
3373 closetype =
3374 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3375
783415f8 3376 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3377 logevent("Forwarded X11 connection terminated");
9c964e85 3378 assert(c->u.x11.s != NULL);
3379 x11_close(c->u.x11.s);
3380 c->u.x11.s = NULL;
3381 }
d74d141c 3382 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3383 logevent("Forwarded port closed");
3384 assert(c->u.pfd.s != NULL);
3385 pfd_close(c->u.pfd.s);
3386 c->u.pfd.s = NULL;
3387 }
0357890f 3388
3389 c->closes |= (closetype << 2); /* seen this message */
3390 if (!(c->closes & closetype)) {
3391 send_packet(pktin.type, PKT_INT, c->remoteid,
3392 PKT_END);
3393 c->closes |= closetype; /* sent it too */
3394 }
3395
3396 if (c->closes == 15) {
32874aea 3397 del234(ssh_channels, c);
3398 sfree(c);
3399 }
d0d844c1 3400 } else {
3401 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3402 pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3403 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3404 i));
32874aea 3405 }
3406 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3407 /* Data sent down one of our channels. */
3408 int i = GET_32BIT(pktin.body);
3409 int len = GET_32BIT(pktin.body + 4);
3410 unsigned char *p = pktin.body + 8;
3411 struct ssh_channel *c;
3412 c = find234(ssh_channels, &i, ssh_channelfind);
3413 if (c) {
5471d09a 3414 int bufsize;
32874aea 3415 switch (c->type) {
3416 case CHAN_X11:
5471d09a 3417 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 3418 break;
d74d141c 3419 case CHAN_SOCKDATA:
5471d09a 3420 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 3421 break;
32874aea 3422 case CHAN_AGENT:
3423 /* Data for an agent message. Buffer it. */
3424 while (len > 0) {
3425 if (c->u.a.lensofar < 4) {
3426 int l = min(4 - c->u.a.lensofar, len);
3427 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3428 l);
3429 p += l;
3430 len -= l;
3431 c->u.a.lensofar += l;
3432 }
3433 if (c->u.a.lensofar == 4) {
3434 c->u.a.totallen =
3435 4 + GET_32BIT(c->u.a.msglen);
3436 c->u.a.message = smalloc(c->u.a.totallen);
3437 memcpy(c->u.a.message, c->u.a.msglen, 4);
3438 }
3439 if (c->u.a.lensofar >= 4 && len > 0) {
3440 int l =
3441 min(c->u.a.totallen - c->u.a.lensofar,
3442 len);
3443 memcpy(c->u.a.message + c->u.a.lensofar, p,
3444 l);
3445 p += l;
3446 len -= l;
3447 c->u.a.lensofar += l;
3448 }
3449 if (c->u.a.lensofar == c->u.a.totallen) {
3450 void *reply, *sentreply;
3451 int replylen;
3452 agent_query(c->u.a.message,
3453 c->u.a.totallen, &reply,
3454 &replylen);
3455 if (reply)
3456 sentreply = reply;
3457 else {
3458 /* Fake SSH_AGENT_FAILURE. */
3459 sentreply = "\0\0\0\1\5";
3460 replylen = 5;
3461 }
3462 send_packet(SSH1_MSG_CHANNEL_DATA,
3463 PKT_INT, c->remoteid,
3464 PKT_INT, replylen,
3465 PKT_DATA, sentreply, replylen,
3466 PKT_END);
3467 if (reply)
3468 sfree(reply);
3469 sfree(c->u.a.message);
3470 c->u.a.lensofar = 0;
3471 }
3472 }
5471d09a 3473 bufsize = 0; /* agent channels never back up */
32874aea 3474 break;
3475 }
90347b95 3476 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3477 c->v.v1.throttling = 1;
3478 ssh1_throttle(+1);
3479 }
32874aea 3480 }
e5574168 3481 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3482 /* may be from EXEC_SHELL on some servers */
e5574168 3483 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3484 /* may be from EXEC_SHELL on some servers
374330e2 3485 * if no pty is available or in other odd cases. Ignore */
e5574168 3486 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3487 char buf[100];
3488 ssh_exitcode = GET_32BIT(pktin.body);
3489 sprintf(buf, "Server sent command exit status %d",
3490 ssh_exitcode);
3491 logevent(buf);
e5574168 3492 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3493 /*
3494 * In case `helpful' firewalls or proxies tack
3495 * extra human-readable text on the end of the
3496 * session which we might mistake for another
3497 * encrypted packet, we close the session once
3498 * we've sent EXIT_CONFIRMATION.
3499 */
3500 ssh_state = SSH_STATE_CLOSED;
3501 crReturnV;
374330e2 3502 } else {
8d5de777 3503 bombout(("Strange packet received: type %d", pktin.type));
32874aea 3504 crReturnV;
374330e2 3505 }
3506 } else {
8df7a775 3507 while (inlen > 0) {
3508 int len = min(inlen, 512);
3509 send_packet(SSH1_CMSG_STDIN_DATA,
3510 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3511 in += len;
3512 inlen -= len;
3513 }
374330e2 3514 }
3515 }
3516
3517 crFinishV;
3518}
3519
3520/*
e5574168 3521 * Utility routine for decoding comma-separated strings in KEXINIT.
3522 */
32874aea 3523static int in_commasep_string(char *needle, char *haystack, int haylen)
3524{
e5574168 3525 int needlen = strlen(needle);
3526 while (1) {
32874aea 3527 /*
3528 * Is it at the start of the string?
3529 */
3530 if (haylen >= needlen && /* haystack is long enough */
3531 !memcmp(needle, haystack, needlen) && /* initial match */
3532 (haylen == needlen || haystack[needlen] == ',')
3533 /* either , or EOS follows */
3534 )
3535 return 1;
3536 /*
3537 * If not, search for the next comma and resume after that.
3538 * If no comma found, terminate.
3539 */
3540 while (haylen > 0 && *haystack != ',')
3541 haylen--, haystack++;
3542 if (haylen == 0)
3543 return 0;
3544 haylen--, haystack++; /* skip over comma itself */
e5574168 3545 }
3546}
3547
3548/*
d39f364a 3549 * SSH2 key creation method.
3550 */
32874aea 3551static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3552 char *keyspace)
3553{
d39f364a 3554 SHA_State s;
3555 /* First 20 bytes. */
3556 SHA_Init(&s);
088bde77 3557 if (!(ssh_remote_bugs & BUG_SSH2_DERIVEKEY))
3558 sha_mpint(&s, K);
d39f364a 3559 SHA_Bytes(&s, H, 20);
3560 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3561 SHA_Bytes(&s, sessid, 20);
d39f364a 3562 SHA_Final(&s, keyspace);
3563 /* Next 20 bytes. */
3564 SHA_Init(&s);
088bde77 3565 if (!(ssh_remote_bugs & BUG_SSH2_DERIVEKEY))
3566 sha_mpint(&s, K);
d39f364a 3567 SHA_Bytes(&s, H, 20);
3568 SHA_Bytes(&s, keyspace, 20);
32874aea 3569 SHA_Final(&s, keyspace + 20);
d39f364a 3570}
3571
3572/*
7cca0d81 3573 * Handle the SSH2 transport layer.
e5574168 3574 */
7cca0d81 3575static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 3576{
ca20bfcf 3577 static int i, j, len, nbits, pbits, warn;
e5574168 3578 static char *str;
a92dd380 3579 static Bignum p, g, e, f, K;
3580 static int kex_init_value, kex_reply_value;
7591b9ff 3581 static const struct ssh_mac **maclist;
8b2715b2 3582 static int nmacs;
0a3f1d48 3583 static const struct ssh2_cipher *cscipher_tobe = NULL;
3584 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 3585 static const struct ssh_mac *csmac_tobe = NULL;
3586 static const struct ssh_mac *scmac_tobe = NULL;
3587 static const struct ssh_compress *cscomp_tobe = NULL;
3588 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 3589 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 3590 static int hostkeylen, siglen;
e055a386 3591 static void *hkey; /* actual host key */
e5574168 3592 static unsigned char exchange_hash[20];
d39f364a 3593 static unsigned char keyspace[40];
ca20bfcf 3594 static int n_preferred_ciphers;
3595 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4ba9b64b 3596 static const struct ssh_compress *preferred_comp;
087abe1a 3597 static int cipherstr_started;
0db56f73 3598 static int first_kex;
e5574168 3599
3600 crBegin;
7cca0d81 3601 random_init();
0db56f73 3602 first_kex = 1;
e5574168 3603
5e8358ad 3604 /*
ca20bfcf 3605 * Set up the preferred ciphers. (NULL => warn below here)
5e8358ad 3606 */
ca20bfcf 3607 n_preferred_ciphers = 0;
3608 for (i = 0; i < CIPHER_MAX; i++) {
3609 switch (cfg.ssh_cipherlist[i]) {
3610 case CIPHER_BLOWFISH:
3611 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3612 n_preferred_ciphers++;
3613 break;
3614 case CIPHER_DES:
087abe1a 3615 if (cfg.ssh2_des_cbc) {
3616 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3617 n_preferred_ciphers++;
3618 }
ca20bfcf 3619 break;
3620 case CIPHER_3DES:
3621 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3622 n_preferred_ciphers++;
3623 break;
3624 case CIPHER_AES:
3625 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3626 n_preferred_ciphers++;
3627 break;
3628 case CIPHER_WARN:
3629 /* Flag for later. Don't bother if it's the last in
3630 * the list. */
3631 if (i < CIPHER_MAX - 1) {
3632 preferred_ciphers[n_preferred_ciphers] = NULL;
3633 n_preferred_ciphers++;
3634 }
3635 break;
3636 }
5e8358ad 3637 }
ca20bfcf 3638
3639 /*
3640 * Set up preferred compression.
3641 */
4ba9b64b 3642 if (cfg.compression)
3643 preferred_comp = &ssh_zlib;
3644 else
3645 preferred_comp = &ssh_comp_none;
5e8358ad 3646
7591b9ff 3647 /*
3648 * Be prepared to work around the buggy MAC problem.
3649 */
1b56c055 3650 if (ssh_remote_bugs & BUG_SSH2_HMAC)
32874aea 3651 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 3652 else
32874aea 3653 maclist = macs, nmacs = lenof(macs);
7591b9ff 3654
32874aea 3655 begin_key_exchange:
e5574168 3656 /*
3657 * Construct and send our key exchange packet.
3658 */
3659 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3660 for (i = 0; i < 16; i++)
32874aea 3661 ssh2_pkt_addbyte((unsigned char) random_byte());
e5574168 3662 /* List key exchange algorithms. */
3663 ssh2_pkt_addstring_start();
3664 for (i = 0; i < lenof(kex_algs); i++) {
8e975795 3665 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3666 (ssh_remote_bugs & BUG_SSH2_DH_GEX))
3667 continue;
32874aea 3668 ssh2_pkt_addstring_str(kex_algs[i]->name);
3669 if (i < lenof(kex_algs) - 1)
3670 ssh2_pkt_addstring_str(",");
e5574168 3671 }
3672 /* List server host key algorithms. */
3673 ssh2_pkt_addstring_start();
3674 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3675 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3676 if (i < lenof(hostkey_algs) - 1)
3677 ssh2_pkt_addstring_str(",");
e5574168 3678 }
3679 /* List client->server encryption algorithms. */
3680 ssh2_pkt_addstring_start();
087abe1a 3681 cipherstr_started = 0;
ca20bfcf 3682 for (i = 0; i < n_preferred_ciphers; i++) {
3683 const struct ssh2_ciphers *c = preferred_ciphers[i];
3684 if (!c) continue; /* warning flag */
32874aea 3685 for (j = 0; j < c->nciphers; j++) {
087abe1a 3686 if (cipherstr_started)
32874aea 3687 ssh2_pkt_addstring_str(",");
087abe1a 3688 ssh2_pkt_addstring_str(c->list[j]->name);
3689 cipherstr_started = 1;
32874aea 3690 }
e5574168 3691 }
3692 /* List server->client encryption algorithms. */
3693 ssh2_pkt_addstring_start();
087abe1a 3694 cipherstr_started = 0;
ca20bfcf 3695 for (i = 0; i < n_preferred_ciphers; i++) {
3696 const struct ssh2_ciphers *c = preferred_ciphers[i];
3697 if (!c) continue; /* warning flag */
32874aea 3698 for (j = 0; j < c->nciphers; j++) {
087abe1a 3699 if (cipherstr_started)
32874aea 3700 ssh2_pkt_addstring_str(",");
087abe1a 3701 ssh2_pkt_addstring_str(c->list[j]->name);
3702 cipherstr_started = 1;
32874aea 3703 }
e5574168 3704 }
3705 /* List client->server MAC algorithms. */
3706 ssh2_pkt_addstring_start();
8b2715b2 3707 for (i = 0; i < nmacs; i++) {
32874aea 3708 ssh2_pkt_addstring_str(maclist[i]->name);
3709 if (i < nmacs - 1)
3710 ssh2_pkt_addstring_str(",");
e5574168 3711 }
3712 /* List server->client MAC algorithms. */
3713 ssh2_pkt_addstring_start();
8b2715b2 3714 for (i = 0; i < nmacs; i++) {
32874aea 3715 ssh2_pkt_addstring_str(maclist[i]->name);
3716 if (i < nmacs - 1)
3717 ssh2_pkt_addstring_str(",");
e5574168 3718 }
3719 /* List client->server compression algorithms. */
3720 ssh2_pkt_addstring_start();
32874aea 3721 for (i = 0; i < lenof(compressions) + 1; i++) {
3722 const struct ssh_compress *c =
3723 i == 0 ? preferred_comp : compressions[i - 1];
3724 ssh2_pkt_addstring_str(c->name);
3725 if (i < lenof(compressions))
3726 ssh2_pkt_addstring_str(",");
e5574168 3727 }
3728 /* List server->client compression algorithms. */
3729 ssh2_pkt_addstring_start();
32874aea 3730 for (i = 0; i < lenof(compressions) + 1; i++) {
3731 const struct ssh_compress *c =
3732 i == 0 ? preferred_comp : compressions[i - 1];
3733 ssh2_pkt_addstring_str(c->name);
3734 if (i < lenof(compressions))
3735 ssh2_pkt_addstring_str(",");
e5574168 3736 }
3737 /* List client->server languages. Empty list. */
3738 ssh2_pkt_addstring_start();
3739 /* List server->client languages. Empty list. */
3740 ssh2_pkt_addstring_start();
3741 /* First KEX packet does _not_ follow, because we're not that brave. */
3742 ssh2_pkt_addbool(FALSE);
3743 /* Reserved. */
3744 ssh2_pkt_adduint32(0);
0db56f73 3745
3746 exhash = exhashbase;
32874aea 3747 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
0db56f73 3748
e5574168 3749 ssh2_pkt_send();
3750
32874aea 3751 if (!ispkt)
3752 crWaitUntil(ispkt);
3753 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
e5574168 3754
3755 /*
3756 * Now examine the other side's KEXINIT to see what we're up
3757 * to.
3758 */
7cca0d81 3759 if (pktin.type != SSH2_MSG_KEXINIT) {
32874aea 3760 bombout(("expected key exchange packet from server"));
3761 crReturn(0);
7cca0d81 3762 }
32874aea 3763 kex = NULL;
3764 hostkey = NULL;
3765 cscipher_tobe = NULL;
3766 sccipher_tobe = NULL;
3767 csmac_tobe = NULL;
3768 scmac_tobe = NULL;
3769 cscomp_tobe = NULL;
3770 sccomp_tobe = NULL;
3771 pktin.savedpos += 16; /* skip garbage cookie */
e5574168 3772 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3773 for (i = 0; i < lenof(kex_algs); i++) {
8e975795 3774 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3775 (ssh_remote_bugs & BUG_SSH2_DH_GEX))
3776 continue;
32874aea 3777 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3778 kex = kex_algs[i];
3779 break;
3780 }
e5574168 3781 }
3782 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3783 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3784 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3785 hostkey = hostkey_algs[i];
3786 break;
3787 }
e5574168 3788 }
3789 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
ca20bfcf 3790 warn = 0;
3791 for (i = 0; i < n_preferred_ciphers; i++) {
3792 const struct ssh2_ciphers *c = preferred_ciphers[i];
3793 if (!c) {
3794 warn = 1;
3795 } else {
3796 for (j = 0; j < c->nciphers; j++) {
3797 if (in_commasep_string(c->list[j]->name, str, len)) {
3798 cscipher_tobe = c->list[j];
3799 break;
3800 }
32874aea 3801 }
3802 }
ca20bfcf 3803 if (cscipher_tobe) {
3804 if (warn)
3805 askcipher(cscipher_tobe->name, 1);
32874aea 3806 break;
ca20bfcf 3807 }
e5574168 3808 }
0ef8f407 3809 if (!cscipher_tobe) {
3810 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3811 crReturn(0);
3812 }
3813
e5574168 3814 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
ca20bfcf 3815 warn = 0;
3816 for (i = 0; i < n_preferred_ciphers; i++) {
3817 const struct ssh2_ciphers *c = preferred_ciphers[i];
3818 if (!c) {
3819 warn = 1;
3820 } else {
3821 for (j = 0; j < c->nciphers; j++) {
3822 if (in_commasep_string(c->list[j]->name, str, len)) {
3823 sccipher_tobe = c->list[j];
3824 break;
3825 }
32874aea 3826 }
3827 }
ca20bfcf 3828 if (sccipher_tobe) {
3829 if (warn)
3830 askcipher(sccipher_tobe->name, 2);
32874aea 3831 break;
ca20bfcf 3832 }
e5574168 3833 }
0ef8f407 3834 if (!sccipher_tobe) {
3835 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3836 crReturn(0);
3837 }
3838
e5574168 3839 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 3840 for (i = 0; i < nmacs; i++) {
32874aea 3841 if (in_commasep_string(maclist[i]->name, str, len)) {
3842 csmac_tobe = maclist[i];
3843 break;
3844 }
e5574168 3845 }
3846 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 3847 for (i = 0; i < nmacs; i++) {
32874aea 3848 if (in_commasep_string(maclist[i]->name, str, len)) {
3849 scmac_tobe = maclist[i];
3850 break;
3851 }
e5574168 3852 }
3853 ssh2_pkt_getstring(&str, &len); /* client->server compression */
32874aea 3854 for (i = 0; i < lenof(compressions) + 1; i++) {
3855 const struct ssh_compress *c =
3856 i == 0 ? preferred_comp : compressions[i - 1];
3857 if (in_commasep_string(c->name, str, len)) {
3858 cscomp_tobe = c;
3859 break;
3860 }
e5574168 3861 }
3862 ssh2_pkt_getstring(&str, &len); /* server->client compression */
32874aea 3863 for (i = 0; i < lenof(compressions) + 1; i++) {
3864 const struct ssh_compress *c =
3865 i == 0 ? preferred_comp : compressions[i - 1];
3866 if (in_commasep_string(c->name, str, len)) {
3867 sccomp_tobe = c;
3868 break;
3869 }
e5574168 3870 }
e5574168 3871
3872 /*
7bd5a860 3873 * Work out the number of bits of key we will need from the key
3874 * exchange. We start with the maximum key length of either
3875 * cipher...
3876 */
3877 {
32874aea 3878 int csbits, scbits;
7bd5a860 3879
3880 csbits = cscipher_tobe->keylen;
3881 scbits = sccipher_tobe->keylen;
3882 nbits = (csbits > scbits ? csbits : scbits);
3883 }
3884 /* The keys only have 160-bit entropy, since they're based on
3885 * a SHA-1 hash. So cap the key size at 160 bits. */
32874aea 3886 if (nbits > 160)
3887 nbits = 160;
7bd5a860 3888
3889 /*
a92dd380 3890 * If we're doing Diffie-Hellman group exchange, start by
3891 * requesting a group.
e5574168 3892 */
a92dd380 3893 if (kex == &ssh_diffiehellman_gex) {
32874aea 3894 logevent("Doing Diffie-Hellman group exchange");
00db133f 3895 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 3896 /*
3897 * Work out how big a DH group we will need to allow that
3898 * much data.
7bd5a860 3899 */
32874aea 3900 pbits = 512 << ((nbits - 1) / 64);
3901 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3902 ssh2_pkt_adduint32(pbits);
3903 ssh2_pkt_send();
3904
3905 crWaitUntil(ispkt);
3906 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3907 bombout(("expected key exchange group packet from server"));
3908 crReturn(0);
3909 }
3910 p = ssh2_pkt_getmp();
3911 g = ssh2_pkt_getmp();
3912 dh_setup_group(p, g);
3913 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3914 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3915 } else {
00db133f 3916 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
32874aea 3917 dh_setup_group1();
3918 kex_init_value = SSH2_MSG_KEXDH_INIT;
3919 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3920 }
e5574168 3921
a92dd380 3922 logevent("Doing Diffie-Hellman key exchange");
e5574168 3923 /*
a92dd380 3924 * Now generate and send e for Diffie-Hellman.
e5574168 3925 */
32874aea 3926 e = dh_create_e(nbits * 2);
a92dd380 3927 ssh2_pkt_init(kex_init_value);
e5574168 3928 ssh2_pkt_addmp(e);
3929 ssh2_pkt_send();
3930
3931 crWaitUntil(ispkt);
a92dd380 3932 if (pktin.type != kex_reply_value) {
32874aea 3933 bombout(("expected key exchange reply packet from server"));
3934 crReturn(0);
7cca0d81 3935 }
e5574168 3936 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3937 f = ssh2_pkt_getmp();
e5574168 3938 ssh2_pkt_getstring(&sigdata, &siglen);
3939
3940 K = dh_find_K(f);
e5574168 3941
3942 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 3943 if (kex == &ssh_diffiehellman_gex) {
32874aea 3944 sha_uint32(&exhash, pbits);
3945 sha_mpint(&exhash, p);
3946 sha_mpint(&exhash, g);
a92dd380 3947 }
e5574168 3948 sha_mpint(&exhash, e);
3949 sha_mpint(&exhash, f);
3950 sha_mpint(&exhash, K);
3951 SHA_Final(&exhash, exchange_hash);
3952
3709bfe9 3953 dh_cleanup();
3954
7cca0d81 3955#if 0
765c4200 3956 debug(("Exchange hash is:\n"));
3957 dmemdump(exchange_hash, 20);
7cca0d81 3958#endif
3959
e055a386 3960 hkey = hostkey->newkey(hostkeydata, hostkeylen);
f7259d10 3961 if (!hkey ||
3962 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3963 bombout(("Server's host key did not match the signature supplied"));
32874aea 3964 crReturn(0);
8d5de777 3965 }
e5574168 3966
3967 /*
7cca0d81 3968 * Authenticate remote host: verify host key. (We've already
3969 * checked the signature of the exchange hash.)
e5574168 3970 */
e055a386 3971 keystr = hostkey->fmtkey(hkey);
3972 fingerprint = hostkey->fingerprint(hkey);
d4857987 3973 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
32874aea 3974 keystr, fingerprint);
3975 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 3976 logevent("Host key fingerprint is:");
3977 logevent(fingerprint);
3978 }
dcbde236 3979 sfree(fingerprint);
3980 sfree(keystr);
e055a386 3981 hostkey->freekey(hkey);
d39f364a 3982
3983 /*
7cca0d81 3984 * Send SSH2_MSG_NEWKEYS.
d39f364a 3985 */
3986 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3987 ssh2_pkt_send();
d39f364a 3988
3989 /*
8406eaf9 3990 * Expect SSH2_MSG_NEWKEYS from server.
3991 */
3992 crWaitUntil(ispkt);
3993 if (pktin.type != SSH2_MSG_NEWKEYS) {
3994 bombout(("expected new-keys packet from server"));
3995 crReturn(0);
3996 }
3997
3998 /*
d39f364a 3999 * Create and initialise session keys.
4000 */
4001 cscipher = cscipher_tobe;
4002 sccipher = sccipher_tobe;
4003 csmac = csmac_tobe;
4004 scmac = scmac_tobe;
4005 cscomp = cscomp_tobe;
4006 sccomp = sccomp_tobe;
4ba9b64b 4007 cscomp->compress_init();
4008 sccomp->decompress_init();
d39f364a 4009 /*
5e0d7cb8 4010 * Set IVs after keys. Here we use the exchange hash from the
4011 * _first_ key exchange.
d39f364a 4012 */
5e0d7cb8 4013 if (first_kex)
65a22376 4014 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
4015 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 4016 cscipher->setcskey(keyspace);
65a22376 4017 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 4018 sccipher->setsckey(keyspace);
65a22376 4019 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 4020 cscipher->setcsiv(keyspace);
65a22376 4021 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 4022 sccipher->setsciv(keyspace);
65a22376 4023 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 4024 csmac->setcskey(keyspace);
65a22376 4025 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 4026 scmac->setsckey(keyspace);
d39f364a 4027
033b4cef 4028 /*
0db56f73 4029 * If this is the first key exchange phase, we must pass the
4030 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4031 * wants to see it but because it will need time to initialise
4032 * itself before it sees an actual packet. In subsequent key
4033 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4034 * it would only confuse the layer above.
4035 */
4036 if (!first_kex) {
32874aea 4037 crReturn(0);
0db56f73 4038 }
4039 first_kex = 0;
4040
4041 /*
7cca0d81 4042 * Now we're encrypting. Begin returning 1 to the protocol main
4043 * function so that other things can run on top of the
4044 * transport. If we ever see a KEXINIT, we must go back to the
4045 * start.
033b4cef 4046 */
e96adf72 4047 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4048 crReturn(1);
e96adf72 4049 }
5e0d7cb8 4050 logevent("Server initiated key re-exchange");
7cca0d81 4051 goto begin_key_exchange;
e5574168 4052
4053 crFinish(1);
4054}
4055
7cca0d81 4056/*
783415f8 4057 * Add data to an SSH2 channel output buffer.
4058 */
32874aea 4059static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4060 int len)
4061{
5471d09a 4062 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4063}
4064
4065/*
4066 * Attempt to send data on an SSH2 channel.
4067 */
5471d09a 4068static int ssh2_try_send(struct ssh_channel *c)
32874aea 4069{
5471d09a 4070 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4071 int len;
4072 void *data;
4073 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4074 if ((unsigned)len > c->v.v2.remwindow)
4075 len = c->v.v2.remwindow;
4076 if ((unsigned)len > c->v.v2.remmaxpkt)
4077 len = c->v.v2.remmaxpkt;
32874aea 4078 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4079 ssh2_pkt_adduint32(c->remoteid);
4080 ssh2_pkt_addstring_start();
5471d09a 4081 ssh2_pkt_addstring_data(data, len);
32874aea 4082 ssh2_pkt_send();
5471d09a 4083 bufchain_consume(&c->v.v2.outbuffer, len);
4084 c->v.v2.remwindow -= len;
4085 }
4086
4087 /*
4088 * After having sent as much data as we can, return the amount
4089 * still buffered.
4090 */
4091 return bufchain_size(&c->v.v2.outbuffer);
4092}
4093
4094/*
4095 * Potentially enlarge the window on an SSH2 channel.
4096 */
4097static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4098{
6b69f42e 4099 /*
4100 * Never send WINDOW_ADJUST for a channel that the remote side
4101 * already thinks it's closed; there's no point, since it won't
4102 * be sending any more data anyway.
4103 */
4104 if (c->closes != 0)
4105 return;
4106
5471d09a 4107 if (newwin > c->v.v2.locwindow) {
4108 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4109 ssh2_pkt_adduint32(c->remoteid);
4110 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
4111 ssh2_pkt_send();
4112 c->v.v2.locwindow = newwin;
783415f8 4113 }
4114}
4115
4116/*
7cca0d81 4117 * Handle the SSH2 userauth and connection layers.
4118 */
4119static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
4120{
65a22376 4121 static enum {
32874aea 4122 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
761187b6 4123 AUTH_PASSWORD,
4124 AUTH_KEYBOARD_INTERACTIVE
65a22376 4125 } method;
1408a877 4126 static enum {
32874aea 4127 AUTH_TYPE_NONE,
4128 AUTH_TYPE_PUBLICKEY,
4129 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4130 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
761187b6 4131 AUTH_TYPE_PASSWORD,
4bdf7c46 4132 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4133 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
1408a877 4134 } type;
761187b6 4135 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4136 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
b3186d64 4137 static int kbd_inter_running;
1408a877 4138 static int we_are_in;
45068b27 4139 static int num_prompts, curr_prompt, echo;
65a22376 4140 static char username[100];
7e9b7f4b 4141 static int got_username;
65a22376 4142 static char pwprompt[200];
4143 static char password[100];
396778f1 4144 static void *publickey_blob;
4145 static int publickey_bloblen;
7cca0d81 4146
e5574168 4147 crBegin;
4148
7cca0d81 4149 /*
4150 * Request userauth protocol, and await a response to it.
4151 */
4152 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4153 ssh2_pkt_addstring("ssh-userauth");
4154 ssh2_pkt_send();
4155 crWaitUntilV(ispkt);
8d5de777 4156 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 4157 bombout(("Server refused user authentication protocol"));
4158 crReturnV;
8d5de777 4159 }
7cca0d81 4160
4161 /*
1408a877 4162 * We repeat this whole loop, including the username prompt,
4163 * until we manage a successful authentication. If the user
4164 * types the wrong _password_, they are sent back to the
4165 * beginning to try another username. (If they specify a
4166 * username in the config, they are never asked, even if they
4167 * do give a wrong password.)
4168 *
4169 * I think this best serves the needs of
4170 *
4171 * - the people who have no configuration, no keys, and just
4172 * want to try repeated (username,password) pairs until they
4173 * type both correctly
4174 *
4175 * - people who have keys and configuration but occasionally
4176 * need to fall back to passwords
4177 *
4178 * - people with a key held in Pageant, who might not have
4179 * logged in to a particular machine before; so they want to
4180 * type a username, and then _either_ their key will be
4181 * accepted, _or_ they will type a password. If they mistype
4182 * the username they will want to be able to get back and
4183 * retype it!
7cca0d81 4184 */
5bb641e1 4185 username[0] = '\0';
7e9b7f4b 4186 got_username = FALSE;
1408a877 4187 do {
1408a877 4188 /*
4189 * Get a username.
4190 */
7e9b7f4b 4191 if (got_username && !cfg.change_username) {
5bb641e1 4192 /*
4193 * We got a username last time round this loop, and
4194 * with change_username turned off we don't try to get
4195 * it again.
4196 */
4197 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 4198 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4199 if (!ssh_get_line("login as: ",
4200 username, sizeof(username), FALSE)) {
4201 /*
4202 * get_line failed to get a username.
4203 * Terminate.
4204 */
4205 logevent("No username provided. Abandoning session.");
4206 ssh_state = SSH_STATE_CLOSED;
4207 crReturnV;
4208 }
4209 } else {
0405e71f 4210 static int ret;
32874aea 4211 c_write_str("login as: ");
4212 ssh_send_ok = 1;
0405e71f 4213 setup_userpass_input(username, sizeof(username), 1);
4214 do {
32874aea 4215 crWaitUntilV(!ispkt);
0405e71f 4216 ret = process_userpass_input(in, inlen);
4217 } while (ret == 0);
4218 if (ret < 0)
4219 cleanup_exit(0);
32874aea 4220 }
1408a877 4221 c_write_str("\r\n");
7cca0d81 4222 username[strcspn(username, "\n\r")] = '\0';
4223 } else {
4224 char stuff[200];
277fc55e 4225 strncpy(username, cfg.username, sizeof(username));
4226 username[sizeof(username)-1] = '\0';
65a22376 4227 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 4228 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 4229 c_write_str(stuff);
7cca0d81 4230 }
4231 }
7e9b7f4b 4232 got_username = TRUE;
7cca0d81 4233
65a22376 4234 /*
1408a877 4235 * Send an authentication request using method "none": (a)
4236 * just in case it succeeds, and (b) so that we know what
4237 * authentication methods we can usefully try next.
65a22376 4238 */
00db133f 4239 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4240
1408a877 4241 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4242 ssh2_pkt_addstring(username);
32874aea 4243 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4244 ssh2_pkt_addstring("none"); /* method */
4245 ssh2_pkt_send();
4246 type = AUTH_TYPE_NONE;
4247 gotit = FALSE;
4248 we_are_in = FALSE;
7cca0d81 4249
1408a877 4250 tried_pubkey_config = FALSE;
1983e559 4251 tried_agent = FALSE;
b3186d64 4252 tried_keyb_inter = FALSE;
4253 kbd_inter_running = FALSE;
396778f1 4254 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4255 if (*cfg.keyfile) {
231ee168 4256 int keytype;
4257 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4258 keytype = key_type(cfg.keyfile);
4259 if (keytype == SSH_KEYTYPE_SSH2)
4260 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4261 &publickey_bloblen);
4262 else {
4263 char msgbuf[256];
4264 logeventf("Unable to use this key file (%s)",
4265 key_type_to_str(keytype));
4266 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4267 cfg.keyfile, key_type_to_str(keytype));
4268 c_write_str(msgbuf);
4269 publickey_blob = NULL;
4270 }
396778f1 4271 } else
4272 publickey_blob = NULL;
65a22376 4273
1408a877 4274 while (1) {
4275 /*
4276 * Wait for the result of the last authentication request.
4277 */
4278 if (!gotit)
4279 crWaitUntilV(ispkt);
4280 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4281 char *banner;
4282 int size;
4283 /*
4284 * Don't show the banner if we're operating in
4285 * non-verbose non-interactive mode. (It's probably
4286 * a script, which means nobody will read the
4287 * banner _anyway_, and moreover the printing of
4288 * the banner will screw up processing on the
4289 * output of (say) plink.)
4290 */
4291 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4292 ssh2_pkt_getstring(&banner, &size);
4293 if (banner)
4294 c_write_untrusted(banner, size);
4295 }
1408a877 4296 crWaitUntilV(ispkt);
4297 }
4298 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4299 logevent("Access granted");
4300 we_are_in = TRUE;
4301 break;
4302 }
65a22376 4303
b3186d64 4304 if (kbd_inter_running &&
4305 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4306 /*
45068b27 4307 * This is either a further set-of-prompts packet
4308 * in keyboard-interactive authentication, or it's
4309 * the same one and we came back here with `gotit'
4310 * set. In the former case, we must reset the
4311 * curr_prompt variable.
b3186d64 4312 */
45068b27 4313 if (!gotit)
4314 curr_prompt = 0;
6bb26b30 4315 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
b3186d64 4316 bombout(("Strange packet received during authentication: type %d",
1408a877 4317 pktin.type));
38c4a8da 4318 crReturnV;
65a22376 4319 }
4320
1408a877 4321 gotit = FALSE;
65a22376 4322
1408a877 4323 /*
4324 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4325 * we can look at the string in it and know what we can
4326 * helpfully try next.
4327 */
b3186d64 4328 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4329 char *methods;
4330 int methlen;
4331 ssh2_pkt_getstring(&methods, &methlen);
b3186d64 4332 kbd_inter_running = FALSE;
1408a877 4333 if (!ssh2_pkt_getbool()) {
4334 /*
4335 * We have received an unequivocal Access
4336 * Denied. This can translate to a variety of
4337 * messages:
4338 *
4339 * - if we'd just tried "none" authentication,
4340 * it's not worth printing anything at all
4341 *
4342 * - if we'd just tried a public key _offer_,
4343 * the message should be "Server refused our
4344 * key" (or no message at all if the key
4345 * came from Pageant)
4346 *
4347 * - if we'd just tried anything else, the
4348 * message really should be "Access denied".
4349 *
4350 * Additionally, if we'd just tried password
4351 * authentication, we should break out of this
4352 * whole loop so as to go back to the username
4353 * prompt.
4354 */
4355 if (type == AUTH_TYPE_NONE) {
4356 /* do nothing */
4357 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4358 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4359 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4360 c_write_str("Server refused our key\r\n");
4361 logevent("Server refused public key");
4bdf7c46 4362 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4363 /* server declined keyboard-interactive; ignore */
1408a877 4364 } else {
4365 c_write_str("Access denied\r\n");
4366 logevent("Access denied");
4367 if (type == AUTH_TYPE_PASSWORD) {
4368 we_are_in = FALSE;
4369 break;
4370 }
4371 }
4372 } else {
4373 c_write_str("Further authentication required\r\n");
4374 logevent("Further authentication required");
4375 }
65a22376 4376
32874aea 4377 can_pubkey =
4378 in_commasep_string("publickey", methods, methlen);
4379 can_passwd =
4380 in_commasep_string("password", methods, methlen);
f091e308 4381 can_keyb_inter = cfg.try_ki_auth &&
761187b6 4382 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4383 }
65a22376 4384
1408a877 4385 method = 0;
00db133f 4386 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4387
0405e71f 4388 /*
4389 * Most password/passphrase prompts will be
4390 * non-echoing, so we set this to 0 by default.
4391 * Exception is that some keyboard-interactive prompts
4392 * can be echoing, in which case we'll set this to 1.
4393 */
4394 echo = 0;
4395
78afa559 4396 if (!method && can_pubkey && agent_exists() && !tried_agent) {
1983e559 4397 /*
4398 * Attempt public-key authentication using Pageant.
4399 */
4400 static unsigned char request[5], *response, *p;
4401 static int responselen;
4402 static int i, nkeys;
4403 static int authed = FALSE;
4404 void *r;
4405
c0a81592 4406 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4407 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4408
1983e559 4409 tried_agent = TRUE;
4410
4411 logevent("Pageant is running. Requesting keys.");
4412
4413 /* Request the keys held by the agent. */
4414 PUT_32BIT(request, 1);
4415 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4416 agent_query(request, 5, &r, &responselen);
32874aea 4417 response = (unsigned char *) r;
95797139 4418 if (response && responselen >= 5 &&
32874aea 4419 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 4420 p = response + 5;
32874aea 4421 nkeys = GET_32BIT(p);
4422 p += 4;
4423 {
4424 char buf[64];
4425 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4426 logevent(buf);
4427 }
1983e559 4428 for (i = 0; i < nkeys; i++) {
4429 static char *pkblob, *alg, *commentp;
4430 static int pklen, alglen, commentlen;
4431 static int siglen, retlen, len;
4432 static char *q, *agentreq, *ret;
2d466ffd 4433 void *vret;
1983e559 4434
32874aea 4435 {
4436 char buf[64];
4437 sprintf(buf, "Trying Pageant key #%d", i);
4438 logevent(buf);
4439 }
4440 pklen = GET_32BIT(p);
4441 p += 4;
396778f1 4442 if (publickey_blob &&
4443 pklen == publickey_bloblen &&
4444 !memcmp(p, publickey_blob, publickey_bloblen)) {
4445 logevent("This key matches configured key file");
4446 tried_pubkey_config = 1;
4447 }
32874aea 4448 pkblob = p;
4449 p += pklen;
1983e559 4450 alglen = GET_32BIT(pkblob);
4451 alg = pkblob + 4;
32874aea 4452 commentlen = GET_32BIT(p);
4453 p += 4;
4454 commentp = p;
4455 p += commentlen;
1983e559 4456 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4457 ssh2_pkt_addstring(username);
32874aea 4458 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4459 ssh2_pkt_addstring("publickey"); /* method */
4460 ssh2_pkt_addbool(FALSE); /* no signature included */
1983e559 4461 ssh2_pkt_addstring_start();
4462 ssh2_pkt_addstring_data(alg, alglen);
4463 ssh2_pkt_addstring_start();
4464 ssh2_pkt_addstring_data(pkblob, pklen);
4465 ssh2_pkt_send();
4466
4467 crWaitUntilV(ispkt);
4468 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4469 logevent("Key refused");
4470 continue;
4471 }
4472
32874aea 4473 if (flags & FLAG_VERBOSE) {
4474 c_write_str
4475 ("Authenticating with public key \"");
4476 c_write(commentp, commentlen);
4477 c_write_str("\" from agent\r\n");
4478 }
1983e559 4479
4480 /*
4481 * Server is willing to accept the key.
4482 * Construct a SIGN_REQUEST.
4483 */
4484 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4485 ssh2_pkt_addstring(username);
32874aea 4486 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4487 ssh2_pkt_addstring("publickey"); /* method */
1983e559 4488 ssh2_pkt_addbool(TRUE);
4489 ssh2_pkt_addstring_start();
4490 ssh2_pkt_addstring_data(alg, alglen);
4491 ssh2_pkt_addstring_start();
4492 ssh2_pkt_addstring_data(pkblob, pklen);
4493
4494 siglen = pktout.length - 5 + 4 + 20;
32874aea 4495 len = 1; /* message type */
4496 len += 4 + pklen; /* key blob */
4497 len += 4 + siglen; /* data to sign */
4498 len += 4; /* flags */
1983e559 4499 agentreq = smalloc(4 + len);
4500 PUT_32BIT(agentreq, len);
4501 q = agentreq + 4;
4502 *q++ = SSH2_AGENTC_SIGN_REQUEST;
32874aea 4503 PUT_32BIT(q, pklen);
4504 q += 4;
4505 memcpy(q, pkblob, pklen);
4506 q += pklen;
4507 PUT_32BIT(q, siglen);
4508 q += 4;
1983e559 4509 /* Now the data to be signed... */
32874aea 4510 PUT_32BIT(q, 20);
4511 q += 4;
4512 memcpy(q, ssh2_session_id, 20);
4513 q += 20;
4514 memcpy(q, pktout.data + 5, pktout.length - 5);
4515 q += pktout.length - 5;
1983e559 4516 /* And finally the (zero) flags word. */
4517 PUT_32BIT(q, 0);
2d466ffd 4518 agent_query(agentreq, len + 4, &vret, &retlen);
4519 ret = vret;
1983e559 4520 sfree(agentreq);
4521 if (ret) {
4522 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4523 logevent("Sending Pageant's response");
1dd353b5 4524 ssh2_add_sigblob(pkblob, pklen,
4525 ret + 9, GET_32BIT(ret + 5));
1983e559 4526 ssh2_pkt_send();
4527 authed = TRUE;
4528 break;
4529 } else {
32874aea 4530 logevent
4531 ("Pageant failed to answer challenge");
1983e559 4532 sfree(ret);
4533 }
4534 }
4535 }
4536 if (authed)
4537 continue;
4538 }
4539 }
4540
231ee168 4541 if (!method && can_pubkey && publickey_blob
32874aea 4542 && !tried_pubkey_config) {
1408a877 4543 unsigned char *pub_blob;
4544 char *algorithm, *comment;
4545 int pub_blob_len;
65a22376 4546
1408a877 4547 tried_pubkey_config = TRUE;
65a22376 4548
c0a81592 4549 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4550 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4551
65a22376 4552 /*
1408a877 4553 * Try the public key supplied in the configuration.
4554 *
4555 * First, offer the public blob to see if the server is
4556 * willing to accept it.
65a22376 4557 */
1408a877 4558 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4559 &pub_blob_len);
4560 if (pub_blob) {
4561 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4562 ssh2_pkt_addstring(username);
32874aea 4563 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4564 ssh2_pkt_addstring("publickey"); /* method */
4565 ssh2_pkt_addbool(FALSE); /* no signature included */
1408a877 4566 ssh2_pkt_addstring(algorithm);
4567 ssh2_pkt_addstring_start();
4568 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4569 ssh2_pkt_send();
32874aea 4570 logevent("Offered public key"); /* FIXME */
1408a877 4571
4572 crWaitUntilV(ispkt);
4573 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4574 gotit = TRUE;
4575 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4576 continue; /* key refused; give up on it */
1408a877 4577 }
65a22376 4578
1408a877 4579 logevent("Offer of public key accepted");
65a22376 4580 /*
1408a877 4581 * Actually attempt a serious authentication using
4582 * the key.
65a22376 4583 */
1408a877 4584 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
32874aea 4585 sprintf(pwprompt,
4586 "Passphrase for key \"%.100s\": ",
4587 comment);
1408a877 4588 need_pw = TRUE;
4589 } else {
4590 need_pw = FALSE;
4591 }
4592 c_write_str("Authenticating with public key \"");
4593 c_write_str(comment);
4594 c_write_str("\"\r\n");
4595 method = AUTH_PUBLICKEY_FILE;
65a22376 4596 }
1408a877 4597 }
4598
af659722 4599 if (!method && can_keyb_inter && !tried_keyb_inter) {
4600 method = AUTH_KEYBOARD_INTERACTIVE;
4601 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4602 tried_keyb_inter = TRUE;
4603
c0a81592 4604 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4605 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4606
af659722 4607 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4608 ssh2_pkt_addstring(username);
4609 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4610 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4611 ssh2_pkt_addstring(""); /* lang */
4612 ssh2_pkt_addstring("");
4613 ssh2_pkt_send();
4614
4615 crWaitUntilV(ispkt);
4616 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4617 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4618 gotit = TRUE;
4619 logevent("Keyboard-interactive authentication refused");
4620 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4621 continue;
4622 }
4623
4624 kbd_inter_running = TRUE;
45068b27 4625 curr_prompt = 0;
af659722 4626 }
4627
4628 if (kbd_inter_running) {
4629 method = AUTH_KEYBOARD_INTERACTIVE;
4630 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4631 tried_keyb_inter = TRUE;
4632
c0a81592 4633 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4634 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4635
45068b27 4636 if (curr_prompt == 0) {
4637 /*
4638 * We've got a fresh USERAUTH_INFO_REQUEST.
4639 * Display header data, and start going through
4640 * the prompts.
4641 */
4642 char *name, *inst, *lang;
4643 int name_len, inst_len, lang_len;
4644
af659722 4645 ssh2_pkt_getstring(&name, &name_len);
4646 ssh2_pkt_getstring(&inst, &inst_len);
4647 ssh2_pkt_getstring(&lang, &lang_len);
45068b27 4648 if (name_len > 0) {
af659722 4649 c_write_untrusted(name, name_len);
0405e71f 4650 c_write_str("\r\n");
45068b27 4651 }
4652 if (inst_len > 0) {
af659722 4653 c_write_untrusted(inst, inst_len);
0405e71f 4654 c_write_str("\r\n");
45068b27 4655 }
af659722 4656 num_prompts = ssh2_pkt_getuint32();
45068b27 4657 }
af659722 4658
45068b27 4659 /*
4660 * If there are prompts remaining in the packet,
4661 * display one and get a response.
4662 */
4663 if (curr_prompt < num_prompts) {
4664 char *prompt;
4665 int prompt_len;
af659722 4666
45068b27 4667 ssh2_pkt_getstring(&prompt, &prompt_len);
4668 if (prompt_len > 0) {
4669 strncpy(pwprompt, prompt, sizeof(pwprompt));
4670 pwprompt[prompt_len < sizeof(pwprompt) ?
4671 prompt_len : sizeof(pwprompt)-1] = '\0';
4672 } else {
4673 strcpy(pwprompt,
4674 "<server failed to send prompt>: ");
4675 }
af659722 4676 echo = ssh2_pkt_getbool();
45068b27 4677 need_pw = TRUE;
4678 } else
4679 need_pw = FALSE;
af659722 4680 }
4681
1408a877 4682 if (!method && can_passwd) {
4683 method = AUTH_PASSWORD;
c0a81592 4684 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4685 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
32874aea 4686 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4687 savedhost);
1408a877 4688 need_pw = TRUE;
4689 }
4690
4691 if (need_pw) {
fa17a66e 4692 if (ssh_get_line) {
4693 if (!ssh_get_line(pwprompt, password,
32874aea 4694 sizeof(password), TRUE)) {
1408a877 4695 /*
fa17a66e 4696 * get_line failed to get a password (for
4697 * example because one was supplied on the
4698 * command line which has already failed to
4699 * work). Terminate.
1408a877 4700 */
2bc6a386 4701 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4702 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4703 ssh2_pkt_addstring
4704 ("No more passwords available to try");
4705 ssh2_pkt_addstring("en"); /* language tag */
4706 ssh2_pkt_send();
247308b5 4707 logevent("Unable to authenticate");
2bc6a386 4708 connection_fatal("Unable to authenticate");
1408a877 4709 ssh_state = SSH_STATE_CLOSED;
4710 crReturnV;
4711 }
4712 } else {
0405e71f 4713 static int ret;
761187b6 4714 c_write_untrusted(pwprompt, strlen(pwprompt));
1408a877 4715 ssh_send_ok = 1;
4716
0405e71f 4717 setup_userpass_input(password, sizeof(password), echo);
4718 do {
1408a877 4719 crWaitUntilV(!ispkt);
0405e71f 4720 ret = process_userpass_input(in, inlen);
4721 } while (ret == 0);
4722 if (ret < 0)
4723 cleanup_exit(0);
1408a877 4724 c_write_str("\r\n");
65a22376 4725 }
65a22376 4726 }
65a22376 4727
1408a877 4728 if (method == AUTH_PUBLICKEY_FILE) {
4729 /*
4730 * We have our passphrase. Now try the actual authentication.
4731 */
4732 struct ssh2_userkey *key;
65a22376 4733
1408a877 4734 key = ssh2_load_userkey(cfg.keyfile, password);
4735 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4736 if (key == SSH2_WRONG_PASSPHRASE) {
4737 c_write_str("Wrong passphrase\r\n");
4738 tried_pubkey_config = FALSE;
4739 } else {
4740 c_write_str("Unable to load private key\r\n");
4741 tried_pubkey_config = TRUE;
4742 }
4743 /* Send a spurious AUTH_NONE to return to the top. */
4744 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4745 ssh2_pkt_addstring(username);
32874aea 4746 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4747 ssh2_pkt_addstring("none"); /* method */
1408a877 4748 ssh2_pkt_send();
4749 type = AUTH_TYPE_NONE;
4750 } else {
1dd353b5 4751 unsigned char *pkblob, *sigblob, *sigdata;
4752 int pkblob_len, sigblob_len, sigdata_len;
65a22376 4753
1408a877 4754 /*
4755 * We have loaded the private key and the server
4756 * has announced that it's willing to accept it.
4757 * Hallelujah. Generate a signature and send it.
4758 */
4759 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4760 ssh2_pkt_addstring(username);
32874aea 4761 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4762 ssh2_pkt_addstring("publickey"); /* method */
1408a877 4763 ssh2_pkt_addbool(TRUE);
4764 ssh2_pkt_addstring(key->alg->name);
1dd353b5 4765 pkblob = key->alg->public_blob(key->data, &pkblob_len);
1408a877 4766 ssh2_pkt_addstring_start();
1dd353b5 4767 ssh2_pkt_addstring_data(pkblob, pkblob_len);
1408a877 4768
4769 /*
4770 * The data to be signed is:
4771 *
4772 * string session-id
4773 *
4774 * followed by everything so far placed in the
4775 * outgoing packet.
4776 */
4777 sigdata_len = pktout.length - 5 + 4 + 20;
4778 sigdata = smalloc(sigdata_len);
4779 PUT_32BIT(sigdata, 20);
32874aea 4780 memcpy(sigdata + 4, ssh2_session_id, 20);
4781 memcpy(sigdata + 24, pktout.data + 5,
4782 pktout.length - 5);
1dd353b5 4783 sigblob = key->alg->sign(key->data, sigdata,
4784 sigdata_len, &sigblob_len);
4785 ssh2_add_sigblob(pkblob, pkblob_len,
4786 sigblob, sigblob_len);
4787 sfree(pkblob);
4788 sfree(sigblob);
1408a877 4789 sfree(sigdata);
4790
4791 ssh2_pkt_send();
4792 type = AUTH_TYPE_PUBLICKEY;
4793 }
4794 } else if (method == AUTH_PASSWORD) {
65a22376 4795 /*
1408a877 4796 * We send the password packet lumped tightly together with
4797 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4798 * string long enough to make the total length of the two
4799 * packets constant. This should ensure that a passive
4800 * listener doing traffic analyis can't work out the length
4801 * of the password.
4802 *
4803 * For this to work, we need an assumption about the
4804 * maximum length of the password packet. I think 256 is
4805 * pretty conservative. Anyone using a password longer than
4806 * that probably doesn't have much to worry about from
4807 * people who find out how long their password is!
65a22376 4808 */
4809 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4810 ssh2_pkt_addstring(username);
32874aea 4811 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4812 ssh2_pkt_addstring("password");
4813 ssh2_pkt_addbool(FALSE);
4814 ssh2_pkt_addstring(password);
4815 ssh2_pkt_defer();
65a22376 4816 /*
1408a877 4817 * We'll include a string that's an exact multiple of the
4818 * cipher block size. If the cipher is NULL for some
4819 * reason, we don't do this trick at all because we gain
4820 * nothing by it.
65a22376 4821 */
32874aea 4822 if (cscipher) {
4823 int stringlen, i;
4824
4825 stringlen = (256 - deferred_len);
4826 stringlen += cscipher->blksize - 1;
4827 stringlen -= (stringlen % cscipher->blksize);
4828 if (cscomp) {
4829 /*
4830 * Temporarily disable actual compression,
4831 * so we can guarantee to get this string
4832 * exactly the length we want it. The
4833 * compression-disabling routine should
4834 * return an integer indicating how many
4835 * bytes we should adjust our string length
4836 * by.
4837 */
4838 stringlen -= cscomp->disable_compression();
4839 }
1408a877 4840 ssh2_pkt_init(SSH2_MSG_IGNORE);
4841 ssh2_pkt_addstring_start();
6e9e9520 4842 for (i = 0; i < stringlen; i++) {
32874aea 4843 char c = (char) random_byte();
4844 ssh2_pkt_addstring_data(&c, 1);
65a22376 4845 }
1408a877 4846 ssh2_pkt_defer();
65a22376 4847 }
39065bed 4848 ssh_pkt_defersend();
0d43337a 4849 logevent("Sent password");
1408a877 4850 type = AUTH_TYPE_PASSWORD;
761187b6 4851 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
45068b27 4852 if (curr_prompt == 0) {
4853 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4854 ssh2_pkt_adduint32(num_prompts);
4855 }
4856 if (need_pw) { /* only add pw if we just got one! */
4857 ssh2_pkt_addstring(password);
4858 memset(password, 0, sizeof(password));
4859 curr_prompt++;
4860 }
4861 if (curr_prompt >= num_prompts) {
4862 ssh2_pkt_send();
4863 } else {
4864 /*
4865 * If there are prompts remaining, we set
4866 * `gotit' so that we won't attempt to get
4867 * another packet. Then we go back round the
4868 * loop and will end up retrieving another
4869 * prompt out of the existing packet. Funky or
4870 * what?
4871 */
4872 gotit = TRUE;
4873 }
761187b6 4874 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 4875 } else {
32874aea 4876 c_write_str
4877 ("No supported authentication methods left to try!\r\n");
4878 logevent
4879 ("No supported authentications offered. Disconnecting");
1408a877 4880 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4881 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
32874aea 4882 ssh2_pkt_addstring
4883 ("No supported authentication methods available");
4884 ssh2_pkt_addstring("en"); /* language tag */
1408a877 4885 ssh2_pkt_send();
4886 ssh_state = SSH_STATE_CLOSED;
4887 crReturnV;
65a22376 4888 }
65a22376 4889 }
1408a877 4890 } while (!we_are_in);
7cca0d81 4891
4892 /*
4893 * Now we're authenticated for the connection protocol. The
4894 * connection protocol will automatically have started at this
4895 * point; there's no need to send SERVICE_REQUEST.
4896 */
4897
4898 /*
4899 * So now create a channel with a session in it.
4900 */
d2371c81 4901 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 4902 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 4903 mainchan->localid = alloc_channel_id();
7cca0d81 4904 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4905 ssh2_pkt_addstring("session");
d211621f 4906 ssh2_pkt_adduint32(mainchan->localid);
5471d09a 4907 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4908 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
32874aea 4909 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 4910 ssh2_pkt_send();
4911 crWaitUntilV(ispkt);
4912 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 4913 bombout(("Server refused to open a session"));
4914 crReturnV;
4915 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 4916 }
d211621f 4917 if (ssh2_pkt_getuint32() != mainchan->localid) {
32874aea 4918 bombout(("Server's channel confirmation cited wrong channel"));
4919 crReturnV;
7cca0d81 4920 }
d211621f 4921 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 4922 mainchan->type = CHAN_MAINSESSION;
4923 mainchan->closes = 0;
5471d09a 4924 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4925 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4926 bufchain_init(&mainchan->v.v2.outbuffer);
783415f8 4927 add234(ssh_channels, mainchan);
7cca0d81 4928 logevent("Opened channel for session");
4929
4930 /*
783415f8 4931 * Potentially enable X11 forwarding.
4932 */
4933 if (cfg.x11_forward) {
32874aea 4934 char proto[20], data[64];
4935 logevent("Requesting X11 forwarding");
4936 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4937 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4938 ssh2_pkt_adduint32(mainchan->remoteid);
4939 ssh2_pkt_addstring("x11-req");
4940 ssh2_pkt_addbool(1); /* want reply */
4941 ssh2_pkt_addbool(0); /* many connections */
4942 ssh2_pkt_addstring(proto);
4943 ssh2_pkt_addstring(data);
4944 ssh2_pkt_adduint32(0); /* screen number */
4945 ssh2_pkt_send();
4946
4947 do {
4948 crWaitUntilV(ispkt);
4949 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4950 unsigned i = ssh2_pkt_getuint32();
4951 struct ssh_channel *c;
4952 c = find234(ssh_channels, &i, ssh_channelfind);
4953 if (!c)
4954 continue; /* nonexistent channel */
5471d09a 4955 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4956 }
4957 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4958
4959 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4960 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4961 bombout(("Unexpected response to X11 forwarding request:"
4962 " packet type %d", pktin.type));
32874aea 4963 crReturnV;
4964 }
4965 logevent("X11 forwarding refused");
4966 } else {
4967 logevent("X11 forwarding enabled");
783415f8 4968 ssh_X11_fwd_enabled = TRUE;
32874aea 4969 }
783415f8 4970 }
4971
4972 /*
bc240b21 4973 * Enable port forwardings.
4974 */
4975 {
4976 static char *e; /* preserve across crReturn */
4977 char type;
4978 int n;
a4fc0d74 4979 int sport,dport,sserv,dserv;
bc240b21 4980 char sports[256], dports[256], host[256];
4981 char buf[1024];
a4fc0d74 4982 struct servent *se;
bc240b21 4983
4984 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4985 /* Add port forwardings. */
4986 e = cfg.portfwd;
4987 while (*e) {
4988 type = *e++;
4989 n = 0;
4990 while (*e && *e != '\t')
4991 sports[n++] = *e++;
4992 sports[n] = 0;
4993 if (*e == '\t')
4994 e++;
4995 n = 0;
4996 while (*e && *e != ':')
4997 host[n++] = *e++;
4998 host[n] = 0;
4999 if (*e == ':')
5000 e++;
5001 n = 0;
5002 while (*e)
5003 dports[n++] = *e++;
5004 dports[n] = 0;
5005 e++;
5006 dport = atoi(dports);
a4fc0d74 5007 dserv = 0;
5008 if (dport == 0) {
5009 dserv = 1;
5010 se = getservbyname(dports, NULL);
5011 if (se != NULL) {
5012 dport = ntohs(se->s_port);
5013 } else {
5014 sprintf(buf,
5015 "Service lookup failed for destination port \"%s\"",
5016 dports);
5017 logevent(buf);
5018 }
5019 }
bc240b21 5020 sport = atoi(sports);
a4fc0d74 5021 sserv = 0;
5022 if (sport == 0) {
5023 sserv = 1;
5024 se = getservbyname(sports, NULL);
5025 if (se != NULL) {
5026 sport = ntohs(se->s_port);
5027 } else {
5028 sprintf(buf,
5029 "Service lookup failed for source port \"%s\"",
5030 sports);
5031 logevent(buf);
5032 }
5033 }
bc240b21 5034 if (sport && dport) {
5035 if (type == 'L') {
5036 pfd_addforward(host, dport, sport);
a4fc0d74 5037 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
5038 " %s:%.*s%.*s%d%.*s",
5039 sserv ? strlen(sports) : 0, sports,
5040 sserv, "(", sport, sserv, ")",
5041 host,
5042 dserv ? strlen(dports) : 0, dports,
5043 dserv, "(", dport, dserv, ")");
bc240b21 5044 logevent(buf);
5045 } else {
5046 struct ssh_rportfwd *pf;
5047 pf = smalloc(sizeof(*pf));
5048 strcpy(pf->dhost, host);
5049 pf->dport = dport;
5050 pf->sport = sport;
5051 if (add234(ssh_rportfwds, pf) != pf) {
5052 sprintf(buf,
95bc8819 5053 "Duplicate remote port forwarding to %s:%d",
bc240b21 5054 host, dport);
5055 logevent(buf);
5056 sfree(pf);
5057 } else {
a4fc0d74 5058 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5059 " forward to %s:%.*s%.*s%d%.*s",
5060 sserv ? strlen(sports) : 0, sports,
5061 sserv, "(", sport, sserv, ")",
5062 host,
5063 dserv ? strlen(dports) : 0, dports,
5064 dserv, "(", dport, dserv, ")");
bc240b21 5065 logevent(buf);
5066 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5067 ssh2_pkt_addstring("tcpip-forward");
5068 ssh2_pkt_addbool(1);/* want reply */
beefa433 5069 if (cfg.rport_acceptall)
5070 ssh2_pkt_addstring("0.0.0.0");
5071 else
5072 ssh2_pkt_addstring("127.0.0.1");
bc240b21 5073 ssh2_pkt_adduint32(sport);
5074 ssh2_pkt_send();
5075
5076 do {
5077 crWaitUntilV(ispkt);
5078 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5079 unsigned i = ssh2_pkt_getuint32();
5080 struct ssh_channel *c;
5081 c = find234(ssh_channels, &i, ssh_channelfind);
5082 if (!c)
5083 continue;/* nonexistent channel */
5471d09a 5084 c->v.v2.remwindow += ssh2_pkt_getuint32();
bc240b21 5085 }
5086 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5087
5088 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5089 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
c9886e66 5090 bombout(("Unexpected response to port "
5091 "forwarding request: packet type %d",
5092 pktin.type));
bc240b21 5093 crReturnV;
5094 }
5095 logevent("Server refused this port forwarding");
5096 } else {
5097 logevent("Remote port forwarding enabled");
5098 }
5099 }
5100 }
5101 }
5102 }
5103 }
5104
5105 /*
36c2a3e9 5106 * Potentially enable agent forwarding.
5107 */
5108 if (cfg.agentfwd && agent_exists()) {
32874aea 5109 logevent("Requesting OpenSSH-style agent forwarding");
5110 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5111 ssh2_pkt_adduint32(mainchan->remoteid);
5112 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5113 ssh2_pkt_addbool(1); /* want reply */
5114 ssh2_pkt_send();
5115
5116 do {
5117 crWaitUntilV(ispkt);
5118 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5119 unsigned i = ssh2_pkt_getuint32();
5120 struct ssh_channel *c;
5121 c = find234(ssh_channels, &i, ssh_channelfind);
5122 if (!c)
5123 continue; /* nonexistent channel */
5471d09a 5124 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5125 }
5126 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5127
5128 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5129 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5130 bombout(("Unexpected response to agent forwarding request:"
5131 " packet type %d", pktin.type));
32874aea 5132 crReturnV;
5133 }
5134 logevent("Agent forwarding refused");
5135 } else {
5136 logevent("Agent forwarding enabled");
36c2a3e9 5137 ssh_agentfwd_enabled = TRUE;
32874aea 5138 }
36c2a3e9 5139 }
5140
5141 /*
7cca0d81 5142 * Now allocate a pty for the session.
5143 */
67779be7 5144 if (!cfg.nopty) {
32874aea 5145 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5146 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5147 ssh2_pkt_addstring("pty-req");
5148 ssh2_pkt_addbool(1); /* want reply */
5149 ssh2_pkt_addstring(cfg.termtype);
f278d6f8 5150 ssh2_pkt_adduint32(ssh_term_width);
5151 ssh2_pkt_adduint32(ssh_term_height);
32874aea 5152 ssh2_pkt_adduint32(0); /* pixel width */
5153 ssh2_pkt_adduint32(0); /* pixel height */
5154 ssh2_pkt_addstring_start();
5155 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5156 ssh2_pkt_send();
5157 ssh_state = SSH_STATE_INTERMED;
5158
5159 do {
5160 crWaitUntilV(ispkt);
5161 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5162 unsigned i = ssh2_pkt_getuint32();
5163 struct ssh_channel *c;
5164 c = find234(ssh_channels, &i, ssh_channelfind);
5165 if (!c)
5166 continue; /* nonexistent channel */
5471d09a 5167 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5168 }
5169 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5170
5171 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5172 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5173 bombout(("Unexpected response to pty request:"
5174 " packet type %d", pktin.type));
32874aea 5175 crReturnV;
5176 }
5177 c_write_str("Server refused to allocate pty\r\n");
5178 ssh_editing = ssh_echoing = 1;
5179 } else {
5180 logevent("Allocated pty");
5181 }
0965bee0 5182 } else {
32874aea 5183 ssh_editing = ssh_echoing = 1;
7cca0d81 5184 }
5185
5186 /*
fd5e5847 5187 * Start a shell or a remote command. We may have to attempt
5188 * this twice if the config data has provided a second choice
5189 * of command.
7cca0d81 5190 */
fd5e5847 5191 while (1) {
5192 int subsys;
5193 char *cmd;
5194
5195 if (ssh_fallback_cmd) {
5196 subsys = cfg.ssh_subsys2;
5197 cmd = cfg.remote_cmd_ptr2;
5198 } else {
5199 subsys = cfg.ssh_subsys;
5200 cmd = cfg.remote_cmd_ptr;
5201 }
5202
5203 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5204 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5205 if (subsys) {
5206 ssh2_pkt_addstring("subsystem");
5207 ssh2_pkt_addbool(1); /* want reply */
5208 ssh2_pkt_addstring(cmd);
5209 } else if (*cmd) {
5210 ssh2_pkt_addstring("exec");
5211 ssh2_pkt_addbool(1); /* want reply */
5212 ssh2_pkt_addstring(cmd);
5213 } else {
5214 ssh2_pkt_addstring("shell");
5215 ssh2_pkt_addbool(1); /* want reply */
32874aea 5216 }
fd5e5847 5217 ssh2_pkt_send();
5218 do {
5219 crWaitUntilV(ispkt);
5220 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5221 unsigned i = ssh2_pkt_getuint32();
5222 struct ssh_channel *c;
5223 c = find234(ssh_channels, &i, ssh_channelfind);
5224 if (!c)
5225 continue; /* nonexistent channel */
5226 c->v.v2.remwindow += ssh2_pkt_getuint32();
5227 }
5228 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5229 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5230 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5231 bombout(("Unexpected response to shell/command request:"
5232 " packet type %d", pktin.type));
fd5e5847 5233 crReturnV;
5234 }
5235 /*
5236 * We failed to start the command. If this is the
5237 * fallback command, we really are finished; if it's
5238 * not, and if the fallback command exists, try falling
5239 * back to it before complaining.
5240 */
5241 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5242 logevent("Primary command failed; attempting fallback");
5243 ssh_fallback_cmd = TRUE;
5244 continue;
5245 }
5246 bombout(("Server refused to start a shell/command"));
32874aea 5247 crReturnV;
fd5e5847 5248 } else {
5249 logevent("Started a shell/command");
32874aea 5250 }
fd5e5847 5251 break;
7cca0d81 5252 }
5253
6e48c3fe 5254 ssh_state = SSH_STATE_SESSION;
5255 if (size_needed)
818ab3bb 5256 ssh_size(ssh_term_width, ssh_term_height);
3687d221 5257 if (eof_needed)
32874aea 5258 ssh_special(TS_EOF);
6e48c3fe 5259
7cca0d81 5260 /*
5261 * Transfer data!
5262 */
760e88b2 5263 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 5264 ssh_send_ok = 1;
7cca0d81 5265 while (1) {
32874aea 5266 static int try_send;
e5574168 5267 crReturnV;
32874aea 5268 try_send = FALSE;
7cca0d81 5269 if (ispkt) {
5270 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
32874aea 5271 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5272 char *data;
5273 int length;
5274 unsigned i = ssh2_pkt_getuint32();
5275 struct ssh_channel *c;
5276 c = find234(ssh_channels, &i, ssh_channelfind);
5277 if (!c)
5278 continue; /* nonexistent channel */
5279 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5280 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5281 continue; /* extended but not stderr */
5282 ssh2_pkt_getstring(&data, &length);
5283 if (data) {
5471d09a 5284 int bufsize;
5285 c->v.v2.locwindow -= length;
32874aea 5286 switch (c->type) {
5287 case CHAN_MAINSESSION:
5471d09a 5288 bufsize =
887035a5 5289 from_backend(frontend, pktin.type ==
5471d09a 5290 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5291 data, length);
32874aea 5292 break;
5293 case CHAN_X11:
5471d09a 5294 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5295 break;
d74d141c 5296 case CHAN_SOCKDATA:
5471d09a 5297 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5298 break;
36c2a3e9 5299 case CHAN_AGENT:
32874aea 5300 while (length > 0) {
5301 if (c->u.a.lensofar < 4) {
5302 int l = min(4 - c->u.a.lensofar, length);
5303 memcpy(c->u.a.msglen + c->u.a.lensofar,
5304 data, l);
5305 data += l;
5306 length -= l;
5307 c->u.a.lensofar += l;
5308 }
5309 if (c->u.a.lensofar == 4) {
5310 c->u.a.totallen =
5311 4 + GET_32BIT(c->u.a.msglen);
5312 c->u.a.message = smalloc(c->u.a.totallen);
5313 memcpy(c->u.a.message, c->u.a.msglen, 4);
5314 }
5315 if (c->u.a.lensofar >= 4 && length > 0) {
5316 int l =
5317 min(c->u.a.totallen - c->u.a.lensofar,
5318 length);
5319 memcpy(c->u.a.message + c->u.a.lensofar,
5320 data, l);
5321 data += l;
5322 length -= l;
5323 c->u.a.lensofar += l;
5324 }
5325 if (c->u.a.lensofar == c->u.a.totallen) {
5326 void *reply, *sentreply;
5327 int replylen;
5328 agent_query(c->u.a.message,
5329 c->u.a.totallen, &reply,
5330 &replylen);
5331 if (reply)
5332 sentreply = reply;
5333 else {
5334 /* Fake SSH_AGENT_FAILURE. */
5335 sentreply = "\0\0\0\1\5";
5336 replylen = 5;
5337 }
5338 ssh2_add_channel_data(c, sentreply,
5339 replylen);
36c2a3e9 5340 try_send = TRUE;
32874aea 5341 if (reply)
5342 sfree(reply);
5343 sfree(c->u.a.message);
5344 c->u.a.lensofar = 0;
5345 }
5346 }
5471d09a 5347 bufsize = 0;
32874aea 5348 break;
5349 }
5350 /*
5471d09a 5351 * If we are not buffering too much data,
5352 * enlarge the window again at the remote side.
32874aea 5353 */
5471d09a 5354 if (bufsize < OUR_V2_WINSIZE)
5355 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5356 }
7cca0d81 5357 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
32874aea 5358 ssh_state = SSH_STATE_CLOSED;
d211621f 5359 logevent("Received disconnect message");
32874aea 5360 crReturnV;
d211621f 5361 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
32874aea 5362 unsigned i = ssh2_pkt_getuint32();
5363 struct ssh_channel *c;
5364
5365 c = find234(ssh_channels, &i, ssh_channelfind);
5366 if (!c)
5367 continue; /* nonexistent channel */
5368
5369 if (c->type == CHAN_X11) {
5370 /*
5371 * Remote EOF on an X11 channel means we should
5372 * wrap up and close the channel ourselves.
5373 */
5374 x11_close(c->u.x11.s);
5375 sshfwd_close(c);
5376 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5377 sshfwd_close(c);
d74d141c 5378 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5379 pfd_close(c->u.pfd.s);
5380 sshfwd_close(c);
36c2a3e9 5381 }
d211621f 5382 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
32874aea 5383 unsigned i = ssh2_pkt_getuint32();
5384 struct ssh_channel *c;
5385
5386 c = find234(ssh_channels, &i, ssh_channelfind);
d0d844c1 5387 if (!c || ((int)c->remoteid) == -1) {
5388 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5389 c ? "half-open" : "nonexistent", i));
5390 }
32874aea 5391 /* Do pre-close processing on the channel. */
5392 switch (c->type) {
5393 case CHAN_MAINSESSION:
5394 break; /* nothing to see here, move along */
5395 case CHAN_X11:
92f157bd 5396 if (c->u.x11.s != NULL)
5397 x11_close(c->u.x11.s);
5398 sshfwd_close(c);
32874aea 5399 break;
5400 case CHAN_AGENT:
92f157bd 5401 sshfwd_close(c);
32874aea 5402 break;
d74d141c 5403 case CHAN_SOCKDATA:
92f157bd 5404 if (c->u.pfd.s != NULL)
5405 pfd_close(c->u.pfd.s);
5406 sshfwd_close(c);
bc240b21 5407 break;
32874aea 5408 }
92f157bd 5409 if (c->closes == 0) {
5410 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5411 ssh2_pkt_adduint32(c->remoteid);
5412 ssh2_pkt_send();
5413 }
32874aea 5414 del234(ssh_channels, c);
5471d09a 5415 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5416 sfree(c);
5417
5418 /*
5419 * See if that was the last channel left open.
5420 */
5421 if (count234(ssh_channels) == 0) {
ca2914d1 5422#if 0
5423 /*
5424 * We used to send SSH_MSG_DISCONNECT here,
5425 * because I'd believed that _every_ conforming
5426 * SSH2 connection had to end with a disconnect
5427 * being sent by at least one side; apparently
5428 * I was wrong and it's perfectly OK to
5429 * unceremoniously slam the connection shut
5430 * when you're done, and indeed OpenSSH feels
5431 * this is more polite than sending a
5432 * DISCONNECT. So now we don't.
5433 */
32874aea 5434 logevent("All channels closed. Disconnecting");
5435 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5436 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5437 ssh2_pkt_addstring("All open channels closed");
5438 ssh2_pkt_addstring("en"); /* language tag */
5439 ssh2_pkt_send();
ca2914d1 5440#endif
32874aea 5441 ssh_state = SSH_STATE_CLOSED;
5442 crReturnV;
5443 }
5444 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 5445 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
32874aea 5446 unsigned i = ssh2_pkt_getuint32();
5447 struct ssh_channel *c;
5448 c = find234(ssh_channels, &i, ssh_channelfind);
5449 if (!c)
5450 continue; /* nonexistent channel */
5471d09a 5451 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5452 try_send = TRUE;
bc240b21 5453 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5454 unsigned i = ssh2_pkt_getuint32();
5455 struct ssh_channel *c;
5456 c = find234(ssh_channels, &i, ssh_channelfind);
5457 if (!c)
5458 continue; /* nonexistent channel */
5459 if (c->type != CHAN_SOCKDATA_DORMANT)
5460 continue; /* dunno why they're confirming this */
5461 c->remoteid = ssh2_pkt_getuint32();
5462 c->type = CHAN_SOCKDATA;
5471d09a 5463 c->v.v2.remwindow = ssh2_pkt_getuint32();
5464 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4ed34d25 5465 if (c->u.pfd.s)
5466 pfd_confirm(c->u.pfd.s);
5467 if (c->closes) {
5468 /*
5469 * We have a pending close on this channel,
5470 * which we decided on before the server acked
5471 * the channel open. So now we know the
5472 * remoteid, we can close it again.
5473 */
5474 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5475 ssh2_pkt_adduint32(c->remoteid);
5476 ssh2_pkt_send();
5477 }
724cface 5478 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5479 unsigned i = ssh2_pkt_getuint32();
5480 struct ssh_channel *c;
5481 c = find234(ssh_channels, &i, ssh_channelfind);
5482 if (!c)
5483 continue; /* nonexistent channel */
5484 if (c->type != CHAN_SOCKDATA_DORMANT)
5485 continue; /* dunno why they're failing this */
5486
5487 logevent("Forwarded connection refused by server");
5488
5489 pfd_close(c->u.pfd.s);
5490
5491 del234(ssh_channels, c);
5492 sfree(c);
ebb0a590 5493 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5494 unsigned localid;
5495 char *type;
5496 int typelen, want_reply;
5497 struct ssh_channel *c;
5498
5499 localid = ssh2_pkt_getuint32();
5500 ssh2_pkt_getstring(&type, &typelen);
5501 want_reply = ssh2_pkt_getbool();
5502
5503 /*
5504 * First, check that the channel exists. Otherwise,
5505 * we can instantly disconnect with a rude message.
5506 */
5507 c = find234(ssh_channels, &localid, ssh_channelfind);
5508 if (!c) {
5509 char buf[80];
5510 sprintf(buf, "Received channel request for nonexistent"
5511 " channel %d", localid);
5512 logevent(buf);
5513 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5514 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5515 ssh2_pkt_addstring(buf);
5516 ssh2_pkt_addstring("en"); /* language tag */
5517 ssh2_pkt_send();
247308b5 5518 connection_fatal("%s", buf);
ebb0a590 5519 ssh_state = SSH_STATE_CLOSED;
5520 crReturnV;
5521 }
5522
5523 /*
d8d6c7e5 5524 * Having got the channel number, we now look at
5525 * the request type string to see if it's something
5526 * we recognise.
ebb0a590 5527 */
d8d6c7e5 5528 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5529 c == mainchan) {
5530 /* We recognise "exit-status" on the primary channel. */
5531 char buf[100];
5532 ssh_exitcode = ssh2_pkt_getuint32();
5533 sprintf(buf, "Server sent command exit status %d",
5534 ssh_exitcode);
5535 logevent(buf);
5536 if (want_reply) {
5537 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5538 ssh2_pkt_adduint32(c->remoteid);
5539 ssh2_pkt_send();
5540 }
5541 } else {
5542 /*
5543 * This is a channel request we don't know
5544 * about, so we now either ignore the request
5545 * or respond with CHANNEL_FAILURE, depending
5546 * on want_reply.
5547 */
5548 if (want_reply) {
5549 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5550 ssh2_pkt_adduint32(c->remoteid);
5551 ssh2_pkt_send();
5552 }
ebb0a590 5553 }
697d4856 5554 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5555 char *type;
5556 int typelen, want_reply;
5557
5558 ssh2_pkt_getstring(&type, &typelen);
5559 want_reply = ssh2_pkt_getbool();
5560
5561 /*
5562 * We currently don't support any global requests
5563 * at all, so we either ignore the request or
5564 * respond with REQUEST_FAILURE, depending on
5565 * want_reply.
5566 */
5567 if (want_reply) {
5568 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5569 ssh2_pkt_send();
5570 }
783415f8 5571 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5572 char *type;
5573 int typelen;
5574 char *error = NULL;
5575 struct ssh_channel *c;
bc240b21 5576 unsigned remid, winsize, pktsize;
32874aea 5577 ssh2_pkt_getstring(&type, &typelen);
5578 c = smalloc(sizeof(struct ssh_channel));
5579
bc240b21 5580 remid = ssh2_pkt_getuint32();
5581 winsize = ssh2_pkt_getuint32();
5582 pktsize = ssh2_pkt_getuint32();
5583
32874aea 5584 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5585 if (!ssh_X11_fwd_enabled)
5586 error = "X11 forwarding is not enabled";
5587 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5588 NULL) {
5589 error = "Unable to open an X11 connection";
5590 } else {
5591 c->type = CHAN_X11;
5592 }
bc240b21 5593 } else if (typelen == 15 &&
5594 !memcmp(type, "forwarded-tcpip", 15)) {
5595 struct ssh_rportfwd pf, *realpf;
5596 char *dummy;
5597 int dummylen;
5598 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5599 pf.sport = ssh2_pkt_getuint32();
5600 realpf = find234(ssh_rportfwds, &pf, NULL);
5601 if (realpf == NULL) {
5602 error = "Remote port is not recognised";
5603 } else {
5604 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5605 realpf->dport, c);
5606 char buf[1024];
5607 sprintf(buf, "Received remote port open request for %s:%d",
5608 realpf->dhost, realpf->dport);
5609 logevent(buf);
5610 if (e != NULL) {
5611 sprintf(buf, "Port open failed: %s", e);
5612 logevent(buf);
5613 error = "Port open failed";
5614 } else {
5615 logevent("Forwarded port opened successfully");
5616 c->type = CHAN_SOCKDATA;
5617 }
5618 }
32874aea 5619 } else if (typelen == 22 &&
36c2a3e9 5620 !memcmp(type, "auth-agent@openssh.com", 3)) {
32874aea 5621 if (!ssh_agentfwd_enabled)
5622 error = "Agent forwarding is not enabled";
36c2a3e9 5623 else {
32874aea 5624 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5625 c->u.a.lensofar = 0;
32874aea 5626 }
5627 } else {
5628 error = "Unsupported channel type requested";
5629 }
5630
bc240b21 5631 c->remoteid = remid;
32874aea 5632 if (error) {
5633 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5634 ssh2_pkt_adduint32(c->remoteid);
5635 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5636 ssh2_pkt_addstring(error);
5637 ssh2_pkt_addstring("en"); /* language tag */
5638 ssh2_pkt_send();
5639 sfree(c);
5640 } else {
5641 c->localid = alloc_channel_id();
5642 c->closes = 0;
5471d09a 5643 c->v.v2.locwindow = OUR_V2_WINSIZE;
5644 c->v.v2.remwindow = winsize;
5645 c->v.v2.remmaxpkt = pktsize;
5646 bufchain_init(&c->v.v2.outbuffer);
32874aea 5647 add234(ssh_channels, c);
5648 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5649 ssh2_pkt_adduint32(c->remoteid);
5650 ssh2_pkt_adduint32(c->localid);
5471d09a 5651 ssh2_pkt_adduint32(c->v.v2.locwindow);
32874aea 5652 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5653 ssh2_pkt_send();
5654 }
7cca0d81 5655 } else {
8d5de777 5656 bombout(("Strange packet received: type %d", pktin.type));
32874aea 5657 crReturnV;
7cca0d81 5658 }
5659 } else {
32874aea 5660 /*
5661 * We have spare data. Add it to the channel buffer.
5662 */
5663 ssh2_add_channel_data(mainchan, in, inlen);
5664 try_send = TRUE;
5665 }
5666 if (try_send) {
5667 int i;
5668 struct ssh_channel *c;
5669 /*
5670 * Try to send data on all channels if we can.
5671 */
5471d09a 5672 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5673 int bufsize = ssh2_try_send(c);
5674 if (bufsize == 0) {
5675 switch (c->type) {
5676 case CHAN_MAINSESSION:
5677 /* stdin need not receive an unthrottle
5678 * notification since it will be polled */
5679 break;
5680 case CHAN_X11:
5681 x11_unthrottle(c->u.x11.s);
5682 break;
5683 case CHAN_AGENT:
5684 /* agent sockets are request/response and need no
5685 * buffer management */
5686 break;
5687 case CHAN_SOCKDATA:
5688 pfd_unthrottle(c->u.pfd.s);
5689 break;
5690 }
5691 }
5692 }
7cca0d81 5693 }
e5574168 5694 }
5695
5696 crFinishV;
5697}
5698
5699/*
7cca0d81 5700 * Handle the top-level SSH2 protocol.
5701 */
5702static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5703{
5704 if (do_ssh2_transport(in, inlen, ispkt) == 0)
32874aea 5705 return;
7cca0d81 5706 do_ssh2_authconn(in, inlen, ispkt);
5707}
5708
5709/*
8df7a775 5710 * Called to set up the connection.
374330e2 5711 *
5712 * Returns an error message, or NULL on success.
374330e2 5713 */
887035a5 5714static char *ssh_init(void *frontend_handle,
5715 char *host, int port, char **realhost, int nodelay)
32874aea 5716{
fb09bf1c 5717 char *p;
32874aea 5718
8f203108 5719#ifdef MSCRYPTOAPI
32874aea 5720 if (crypto_startup() == 0)
8f203108 5721 return "Microsoft high encryption pack not installed!";
5722#endif
374330e2 5723
887035a5 5724 frontend = frontend_handle;
f278d6f8 5725 ssh_term_width = cfg.width;
5726 ssh_term_height = cfg.height;
887035a5 5727
8df7a775 5728 ssh_send_ok = 0;
0965bee0 5729 ssh_editing = 0;
5730 ssh_echoing = 0;
5471d09a 5731 ssh1_throttle_count = 0;
5732 ssh_overall_bufsize = 0;
fd5e5847 5733 ssh_fallback_cmd = 0;
8df7a775 5734
2184a5d9 5735 p = connect_to_host(host, port, realhost, nodelay);
fb09bf1c 5736 if (p != NULL)
5737 return p;
374330e2 5738
374330e2 5739 return NULL;
5740}
5741
5742/*
374330e2 5743 * Called to send data down the Telnet connection.
5744 */
5471d09a 5745static int ssh_send(char *buf, int len)
32874aea 5746{
f78051a1 5747 if (s == NULL || ssh_protocol == NULL)
5471d09a 5748 return 0;
374330e2 5749
5750 ssh_protocol(buf, len, 0);
5471d09a 5751
5752 return ssh_sendbuffer();
5753}
5754
5755/*
5756 * Called to query the current amount of buffered stdin data.
5757 */
5758static int ssh_sendbuffer(void)
5759{
5760 int override_value;
5761
5762 if (s == NULL || ssh_protocol == NULL)
5763 return 0;
5764
5765 /*
5766 * If the SSH socket itself has backed up, add the total backup
5767 * size on that to any individual buffer on the stdin channel.
5768 */
5769 override_value = 0;
5770 if (ssh_throttled_all)
5771 override_value = ssh_overall_bufsize;
5772
5773 if (ssh_version == 1) {
5774 return override_value;
5775 } else if (ssh_version == 2) {
5776 if (!mainchan || mainchan->closes > 0)
5777 return override_value;
5778 else
5779 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5780 }
5781
5782 return 0;
374330e2 5783}
5784
5785/*
6e48c3fe 5786 * Called to set the size of the window from SSH's POV.
374330e2 5787 */
f278d6f8 5788static void ssh_size(int width, int height)
32874aea 5789{
f278d6f8 5790 ssh_term_width = width;
5791 ssh_term_height = height;
5792
374330e2 5793 switch (ssh_state) {
5794 case SSH_STATE_BEFORE_SIZE:
3687d221 5795 case SSH_STATE_PREPACKET:
21248260 5796 case SSH_STATE_CLOSED:
374330e2 5797 break; /* do nothing */
5798 case SSH_STATE_INTERMED:
5799 size_needed = TRUE; /* buffer for later */
5800 break;
5801 case SSH_STATE_SESSION:
32874aea 5802 if (!cfg.nopty) {
887035a5 5803 if (!term)
5804 return;
32874aea 5805 if (ssh_version == 1) {
5806 send_packet(SSH1_CMSG_WINDOW_SIZE,
f278d6f8 5807 PKT_INT, ssh_term_height, PKT_INT, ssh_term_width,
32874aea 5808 PKT_INT, 0, PKT_INT, 0, PKT_END);
5809 } else {
5810 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5811 ssh2_pkt_adduint32(mainchan->remoteid);
5812 ssh2_pkt_addstring("window-change");
5813 ssh2_pkt_addbool(0);
f278d6f8 5814 ssh2_pkt_adduint32(ssh_term_width);
5815 ssh2_pkt_adduint32(ssh_term_height);
32874aea 5816 ssh2_pkt_adduint32(0);
5817 ssh2_pkt_adduint32(0);
5818 ssh2_pkt_send();
5819 }
5820 }
5821 break;
374330e2 5822 }
5823}
5824
5825/*
6abbf9e3 5826 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5827 * can send an EOF and collect resulting output (e.g. `plink
5828 * hostname sort').
374330e2 5829 */
32874aea 5830static void ssh_special(Telnet_Special code)
5831{
6abbf9e3 5832 if (code == TS_EOF) {
32874aea 5833 if (ssh_state != SSH_STATE_SESSION) {
5834 /*
5835 * Buffer the EOF in case we are pre-SESSION, so we can
5836 * send it as soon as we reach SESSION.
5837 */
5838 if (code == TS_EOF)
5839 eof_needed = TRUE;
5840 return;
5841 }
5842 if (ssh_version == 1) {
5843 send_packet(SSH1_CMSG_EOF, PKT_END);
5844 } else {
5845 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5846 ssh2_pkt_adduint32(mainchan->remoteid);
5847 ssh2_pkt_send();
5848 }
5849 logevent("Sent EOF message");
ec55b220 5850 } else if (code == TS_PING) {
32874aea 5851 if (ssh_state == SSH_STATE_CLOSED
5852 || ssh_state == SSH_STATE_PREPACKET) return;
5853 if (ssh_version == 1) {
2c9c6388 5854 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
5855 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 5856 } else {
5857 ssh2_pkt_init(SSH2_MSG_IGNORE);
5858 ssh2_pkt_addstring_start();
5859 ssh2_pkt_send();
5860 }
6abbf9e3 5861 } else {
32874aea 5862 /* do nothing */
6abbf9e3 5863 }
374330e2 5864}
5865
d74d141c 5866void *new_sock_channel(Socket s)
5867{
5868 struct ssh_channel *c;
5869 c = smalloc(sizeof(struct ssh_channel));
5870
5871 if (c) {
bc240b21 5872 c->remoteid = -1; /* to be set when open confirmed */
d74d141c 5873 c->localid = alloc_channel_id();
5874 c->closes = 0;
bc240b21 5875 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 5876 c->u.pfd.s = s;
013dd8c0 5877 bufchain_init(&c->v.v2.outbuffer);
d74d141c 5878 add234(ssh_channels, c);
5879 }
5880 return c;
5881}
5882
5471d09a 5883/*
5884 * This is called when stdout/stderr (the entity to which
5885 * from_backend sends data) manages to clear some backlog.
5886 */
5887void ssh_unthrottle(int bufsize)
5888{
5889 if (ssh_version == 1) {
90347b95 5890 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5471d09a 5891 ssh1_stdout_throttling = 0;
5892 ssh1_throttle(-1);
5893 }
5894 } else {
5895 if (mainchan && mainchan->closes == 0)
5896 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5897 }
5898}
5899
d74d141c 5900void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5901{
5902 struct ssh_channel *c = (struct ssh_channel *)channel;
5903 char buf[1024];
5904
5905 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5906 logevent(buf);
5907
bc240b21 5908 if (ssh_version == 1) {
5909 send_packet(SSH1_MSG_PORT_OPEN,
5910 PKT_INT, c->localid,
5911 PKT_STR, hostname,
5912 PKT_INT, port,
5913 //PKT_STR, <org:orgport>,
5914 PKT_END);
5915 } else {
5916 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5917 ssh2_pkt_addstring("direct-tcpip");
5918 ssh2_pkt_adduint32(c->localid);
5471d09a 5919 c->v.v2.locwindow = OUR_V2_WINSIZE;
5920 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
bc240b21 5921 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5922 ssh2_pkt_addstring(hostname);
5923 ssh2_pkt_adduint32(port);
5924 /*
5925 * We make up values for the originator data; partly it's
5926 * too much hassle to keep track, and partly I'm not
5927 * convinced the server should be told details like that
5928 * about my local network configuration.
5929 */
5930 ssh2_pkt_addstring("client-side-connection");
5931 ssh2_pkt_adduint32(0);
5932 ssh2_pkt_send();
5933 }
d74d141c 5934}
5935
5936
32874aea 5937static Socket ssh_socket(void)
5938{
5939 return s;
5940}
8ccc75b0 5941
32874aea 5942static int ssh_sendok(void)
5943{
5944 return ssh_send_ok;
5945}
fb09bf1c 5946
32874aea 5947static int ssh_ldisc(int option)
5948{
5949 if (option == LD_ECHO)
5950 return ssh_echoing;
5951 if (option == LD_EDIT)
5952 return ssh_editing;
0965bee0 5953 return FALSE;
5954}
5955
d8d6c7e5 5956static int ssh_return_exitcode(void)
5957{
5958 return ssh_exitcode;
5959}
5960
374330e2 5961Backend ssh_backend = {
5962 ssh_init,
374330e2 5963 ssh_send,
5471d09a 5964 ssh_sendbuffer,
374330e2 5965 ssh_size,
4017be6d 5966 ssh_special,
8ccc75b0 5967 ssh_socket,
d8d6c7e5 5968 ssh_return_exitcode,
97db3be4 5969 ssh_sendok,
0965bee0 5970 ssh_ldisc,
5471d09a 5971 ssh_unthrottle,
97db3be4 5972 22
bc240b21 5973};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator