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