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Clean up the argv splitter, and in particular stop it from bombing
[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
bd358db1 185
00db133f 186static int ssh_pkt_ctx = 0;
187
188#define translate(x) if (type == x) return #x
189#define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
190char *ssh1_pkt_type(int type)
191{
192 translate(SSH1_MSG_DISCONNECT);
193 translate(SSH1_SMSG_PUBLIC_KEY);
194 translate(SSH1_CMSG_SESSION_KEY);
195 translate(SSH1_CMSG_USER);
196 translate(SSH1_CMSG_AUTH_RSA);
197 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
198 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
199 translate(SSH1_CMSG_AUTH_PASSWORD);
200 translate(SSH1_CMSG_REQUEST_PTY);
201 translate(SSH1_CMSG_WINDOW_SIZE);
202 translate(SSH1_CMSG_EXEC_SHELL);
203 translate(SSH1_CMSG_EXEC_CMD);
204 translate(SSH1_SMSG_SUCCESS);
205 translate(SSH1_SMSG_FAILURE);
206 translate(SSH1_CMSG_STDIN_DATA);
207 translate(SSH1_SMSG_STDOUT_DATA);
208 translate(SSH1_SMSG_STDERR_DATA);
209 translate(SSH1_CMSG_EOF);
210 translate(SSH1_SMSG_EXIT_STATUS);
211 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
212 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
213 translate(SSH1_MSG_CHANNEL_DATA);
214 translate(SSH1_MSG_CHANNEL_CLOSE);
215 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
216 translate(SSH1_SMSG_X11_OPEN);
217 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
218 translate(SSH1_MSG_PORT_OPEN);
219 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
220 translate(SSH1_SMSG_AGENT_OPEN);
221 translate(SSH1_MSG_IGNORE);
222 translate(SSH1_CMSG_EXIT_CONFIRMATION);
223 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
224 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
225 translate(SSH1_MSG_DEBUG);
226 translate(SSH1_CMSG_REQUEST_COMPRESSION);
227 translate(SSH1_CMSG_AUTH_TIS);
228 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
229 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
230 translate(SSH1_CMSG_AUTH_CCARD);
231 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
232 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
233 return "unknown";
234}
235char *ssh2_pkt_type(int type)
236{
237 translate(SSH2_MSG_DISCONNECT);
238 translate(SSH2_MSG_IGNORE);
239 translate(SSH2_MSG_UNIMPLEMENTED);
240 translate(SSH2_MSG_DEBUG);
241 translate(SSH2_MSG_SERVICE_REQUEST);
242 translate(SSH2_MSG_SERVICE_ACCEPT);
243 translate(SSH2_MSG_KEXINIT);
244 translate(SSH2_MSG_NEWKEYS);
245 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
246 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
247 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
248 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
249 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
250 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
251 translate(SSH2_MSG_USERAUTH_REQUEST);
252 translate(SSH2_MSG_USERAUTH_FAILURE);
253 translate(SSH2_MSG_USERAUTH_SUCCESS);
254 translate(SSH2_MSG_USERAUTH_BANNER);
255 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
256 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
257 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
258 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
259 translate(SSH2_MSG_GLOBAL_REQUEST);
260 translate(SSH2_MSG_REQUEST_SUCCESS);
261 translate(SSH2_MSG_REQUEST_FAILURE);
262 translate(SSH2_MSG_CHANNEL_OPEN);
263 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
264 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
265 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
266 translate(SSH2_MSG_CHANNEL_DATA);
267 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
268 translate(SSH2_MSG_CHANNEL_EOF);
269 translate(SSH2_MSG_CHANNEL_CLOSE);
270 translate(SSH2_MSG_CHANNEL_REQUEST);
271 translate(SSH2_MSG_CHANNEL_SUCCESS);
272 translate(SSH2_MSG_CHANNEL_FAILURE);
273 return "unknown";
274}
275#undef translate
276#undef translatec
7d503c31 277
fb09bf1c 278#define GET_32BIT(cp) \
279 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
280 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
281 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
282 ((unsigned long)(unsigned char)(cp)[3]))
283
284#define PUT_32BIT(cp, value) { \
285 (cp)[0] = (unsigned char)((value) >> 24); \
286 (cp)[1] = (unsigned char)((value) >> 16); \
287 (cp)[2] = (unsigned char)((value) >> 8); \
288 (cp)[3] = (unsigned char)(value); }
289
7cca0d81 290enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 291
374330e2 292/* Coroutine mechanics for the sillier bits of the code */
293#define crBegin1 static int crLine = 0;
294#define crBegin2 switch(crLine) { case 0:;
295#define crBegin crBegin1; crBegin2;
296#define crFinish(z) } crLine = 0; return (z)
297#define crFinishV } crLine = 0; return
298#define crReturn(z) \
299 do {\
300 crLine=__LINE__; return (z); case __LINE__:;\
301 } while (0)
302#define crReturnV \
303 do {\
304 crLine=__LINE__; return; case __LINE__:;\
305 } while (0)
306#define crStop(z) do{ crLine = 0; return (z); }while(0)
307#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 308#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 309#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 310
32874aea 311extern char *x11_init(Socket *, char *, void *);
312extern void x11_close(Socket);
5471d09a 313extern int x11_send(Socket, char *, int);
9c964e85 314extern void x11_invent_auth(char *, int, char *, int);
5471d09a 315extern void x11_unthrottle(Socket s);
316extern void x11_override_throttle(Socket s, int enable);
9c964e85 317
d74d141c 318extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
319extern char *pfd_addforward(char *desthost, int destport, int port);
320extern void pfd_close(Socket s);
5471d09a 321extern int pfd_send(Socket s, char *data, int len);
d74d141c 322extern void pfd_confirm(Socket s);
5471d09a 323extern void pfd_unthrottle(Socket s);
324extern void pfd_override_throttle(Socket s, int enable);
325
3d63ca2e 326static void ssh2_pkt_init(int pkt_type);
327static void ssh2_pkt_addbool(unsigned char value);
328static void ssh2_pkt_adduint32(unsigned long value);
329static void ssh2_pkt_addstring_start(void);
330static void ssh2_pkt_addstring_str(char *data);
331static void ssh2_pkt_addstring_data(char *data, int len);
332static void ssh2_pkt_addstring(char *data);
333static char *ssh2_mpint_fmt(Bignum b, int *len);
334static void ssh2_pkt_addmp(Bignum b);
335static int ssh2_pkt_construct(void);
336static void ssh2_pkt_send(void);
337
5471d09a 338/*
339 * Buffer management constants. There are several of these for
340 * various different purposes:
341 *
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
346 * happen very often.
347 *
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
354 *
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
356 * channels.
357 */
358
359#define SSH1_BUFFER_LIMIT 32768
360#define SSH_MAX_BACKLOG 32768
361#define OUR_V2_WINSIZE 16384
d74d141c 362
a92dd380 363const static struct ssh_kex *kex_algs[] = {
a92dd380 364 &ssh_diffiehellman_gex,
32874aea 365 &ssh_diffiehellman
366};
e5574168 367
85cc02bb 368const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 369
32874aea 370static void nullmac_key(unsigned char *key)
371{
372}
373static void nullmac_generate(unsigned char *blk, int len,
374 unsigned long seq)
375{
376}
377static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
378{
379 return 1;
380}
57476f6b 381const static struct ssh_mac ssh_mac_none = {
d39f364a 382 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 383};
8b2715b2 384const static struct ssh_mac *macs[] = {
32874aea 385 &ssh_sha1, &ssh_md5, &ssh_mac_none
386};
8b2715b2 387const static struct ssh_mac *buggymacs[] = {
32874aea 388 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
389};
e5574168 390
32874aea 391static void ssh_comp_none_init(void)
392{
393}
4ba9b64b 394static int ssh_comp_none_block(unsigned char *block, int len,
32874aea 395 unsigned char **outblock, int *outlen)
396{
397 return 0;
398}
399static int ssh_comp_none_disable(void)
400{
4ba9b64b 401 return 0;
402}
57476f6b 403const static struct ssh_compress ssh_comp_none = {
4ba9b64b 404 "none",
405 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 406 ssh_comp_none_init, ssh_comp_none_block,
407 ssh_comp_none_disable
e5574168 408};
4ba9b64b 409extern const struct ssh_compress ssh_zlib;
410const static struct ssh_compress *compressions[] = {
32874aea 411 &ssh_zlib, &ssh_comp_none
412};
374330e2 413
32874aea 414enum { /* channel types */
783415f8 415 CHAN_MAINSESSION,
416 CHAN_X11,
417 CHAN_AGENT,
bc240b21 418 CHAN_SOCKDATA,
419 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 420};
421
dacbd0e8 422/*
423 * 2-3-4 tree storing channels.
424 */
425struct ssh_channel {
d211621f 426 unsigned remoteid, localid;
dacbd0e8 427 int type;
428 int closes;
5471d09a 429 union {
430 struct ssh1_data_channel {
431 int throttling;
432 } v1;
433 struct ssh2_data_channel {
434 bufchain outbuffer;
435 unsigned remwindow, remmaxpkt;
436 unsigned locwindow;
437 } v2;
438 } v;
dacbd0e8 439 union {
32874aea 440 struct ssh_agent_channel {
441 unsigned char *message;
442 unsigned char msglen[4];
443 int lensofar, totallen;
444 } a;
445 struct ssh_x11_channel {
446 Socket s;
447 } x11;
d74d141c 448 struct ssh_pfd_channel {
449 Socket s;
450 } pfd;
dacbd0e8 451 } u;
452};
57476f6b 453
d74d141c 454/*
bc240b21 455 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
456 * 2 use this structure in different ways, reflecting SSH 2's
457 * altogether saner approach to port forwarding.
458 *
459 * In SSH 1, you arrange a remote forwarding by sending the server
460 * the remote port number, and the local destination host:port.
461 * When a connection comes in, the server sends you back that
462 * host:port pair, and you connect to it. This is a ready-made
463 * security hole if you're not on the ball: a malicious server
464 * could send you back _any_ host:port pair, so if you trustingly
465 * connect to the address it gives you then you've just opened the
466 * entire inside of your corporate network just by connecting
467 * through it to a dodgy SSH server. Hence, we must store a list of
468 * host:port pairs we _are_ trying to forward to, and reject a
469 * connection request from the server if it's not in the list.
470 *
471 * In SSH 2, each side of the connection minds its own business and
472 * doesn't send unnecessary information to the other. You arrange a
473 * remote forwarding by sending the server just the remote port
474 * number. When a connection comes in, the server tells you which
475 * of its ports was connected to; and _you_ have to remember what
476 * local host:port pair went with that port number.
477 *
478 * Hence: in SSH 1 this structure stores host:port pairs we intend
479 * to allow connections to, and is indexed by those host:port
480 * pairs. In SSH 2 it stores a mapping from source port to
481 * destination host:port pair, and is indexed by source port.
d74d141c 482 */
483struct ssh_rportfwd {
bc240b21 484 unsigned sport, dport;
485 char dhost[256];
d74d141c 486};
487
57476f6b 488struct Packet {
489 long length;
490 int type;
491 unsigned char *data;
492 unsigned char *body;
493 long savedpos;
494 long maxlen;
495};
496
0db56f73 497static SHA_State exhash, exhashbase;
57476f6b 498
8df7a775 499static Socket s = NULL;
57476f6b 500
501static unsigned char session_key[32];
4ba9b64b 502static int ssh1_compressing;
b96dc54c 503static int ssh1_remote_protoflags;
504static int ssh1_local_protoflags;
db7d555c 505static int ssh_agentfwd_enabled;
9c964e85 506static int ssh_X11_fwd_enabled;
7d503c31 507static int ssh_remote_bugs;
57476f6b 508static const struct ssh_cipher *cipher = NULL;
0a3f1d48 509static const struct ssh2_cipher *cscipher = NULL;
510static const struct ssh2_cipher *sccipher = NULL;
57476f6b 511static const struct ssh_mac *csmac = NULL;
512static const struct ssh_mac *scmac = NULL;
513static const struct ssh_compress *cscomp = NULL;
514static const struct ssh_compress *sccomp = NULL;
515static const struct ssh_kex *kex = NULL;
e055a386 516static const struct ssh_signkey *hostkey = NULL;
65a22376 517static unsigned char ssh2_session_id[20];
57476f6b 518
519static char *savedhost;
520static int savedport;
521static int ssh_send_ok;
0965bee0 522static int ssh_echoing, ssh_editing;
57476f6b 523
32874aea 524static tree234 *ssh_channels; /* indexed by local id */
57476f6b 525static struct ssh_channel *mainchan; /* primary session channel */
d8d6c7e5 526static int ssh_exitcode = -1;
57476f6b 527
d74d141c 528static tree234 *ssh_rportfwds;
529
57476f6b 530static enum {
3687d221 531 SSH_STATE_PREPACKET,
57476f6b 532 SSH_STATE_BEFORE_SIZE,
533 SSH_STATE_INTERMED,
534 SSH_STATE_SESSION,
535 SSH_STATE_CLOSED
3687d221 536} ssh_state = SSH_STATE_PREPACKET;
57476f6b 537
3687d221 538static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 539
540static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
541static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 542static unsigned char *deferred_send_data = NULL;
543static int deferred_len = 0, deferred_size = 0;
57476f6b 544
fd5e5847 545/*
546 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
547 * that fails. This variable is the means by which scp.c can reach
548 * into the SSH code and find out which one it got.
549 */
550int ssh_fallback_cmd = 0;
551
57476f6b 552static int ssh_version;
5471d09a 553static int ssh1_throttle_count;
554static int ssh_overall_bufsize;
555static int ssh_throttled_all;
556static int ssh1_stdout_throttling;
32874aea 557static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
57476f6b 558static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
559static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
560static void ssh_size(void);
32874aea 561static void ssh_special(Telnet_Special);
5471d09a 562static int ssh2_try_send(struct ssh_channel *c);
32874aea 563static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
564 int len);
5471d09a 565static void ssh_throttle_all(int enable, int bufsize);
566static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
32874aea 567static int (*s_rdpkt) (unsigned char **data, int *datalen);
5471d09a 568static int ssh_sendbuffer(void);
57476f6b 569
570static struct rdpkt1_state_tag {
571 long len, pad, biglen, to_read;
572 unsigned long realcrc, gotcrc;
573 unsigned char *p;
574 int i;
575 int chunk;
576} rdpkt1_state;
577
960e736a 578static struct rdpkt2_state_tag {
579 long len, pad, payload, packetlen, maclen;
580 int i;
581 int cipherblk;
582 unsigned long incoming_sequence;
583} rdpkt2_state;
584
32874aea 585static int ssh_channelcmp(void *av, void *bv)
586{
587 struct ssh_channel *a = (struct ssh_channel *) av;
588 struct ssh_channel *b = (struct ssh_channel *) bv;
589 if (a->localid < b->localid)
590 return -1;
591 if (a->localid > b->localid)
592 return +1;
dacbd0e8 593 return 0;
594}
32874aea 595static int ssh_channelfind(void *av, void *bv)
596{
597 unsigned *a = (unsigned *) av;
598 struct ssh_channel *b = (struct ssh_channel *) bv;
599 if (*a < b->localid)
600 return -1;
601 if (*a > b->localid)
602 return +1;
dacbd0e8 603 return 0;
604}
605
bc240b21 606static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 607{
608 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
609 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
610 int i;
bc240b21 611 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 612 return i < 0 ? -1 : +1;
bc240b21 613 if (a->dport > b->dport)
614 return +1;
615 if (a->dport < b->dport)
616 return -1;
617 return 0;
618}
619
620static int ssh_rportcmp_ssh2(void *av, void *bv)
621{
622 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
623 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 624
bc240b21 625 if (a->sport > b->sport)
d74d141c 626 return +1;
bc240b21 627 if (a->sport < b->sport)
628 return -1;
d74d141c 629 return 0;
630}
631
32874aea 632static int alloc_channel_id(void)
633{
260f3dec 634 const unsigned CHANNEL_NUMBER_OFFSET = 256;
635 unsigned low, high, mid;
d2371c81 636 int tsize;
637 struct ssh_channel *c;
638
639 /*
640 * First-fit allocation of channel numbers: always pick the
641 * lowest unused one. To do this, binary-search using the
642 * counted B-tree to find the largest channel ID which is in a
643 * contiguous sequence from the beginning. (Precisely
644 * everything in that sequence must have ID equal to its tree
645 * index plus CHANNEL_NUMBER_OFFSET.)
646 */
647 tsize = count234(ssh_channels);
648
32874aea 649 low = -1;
650 high = tsize;
d2371c81 651 while (high - low > 1) {
652 mid = (high + low) / 2;
653 c = index234(ssh_channels, mid);
654 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
655 low = mid; /* this one is fine */
656 else
657 high = mid; /* this one is past it */
658 }
659 /*
660 * Now low points to either -1, or the tree index of the
661 * largest ID in the initial sequence.
662 */
663 {
664 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
665 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
666 }
667 return low + 1 + CHANNEL_NUMBER_OFFSET;
668}
669
32874aea 670static void c_write(char *buf, int len)
671{
67779be7 672 if ((flags & FLAG_STDERR)) {
32874aea 673 int i;
674 for (i = 0; i < len; i++)
675 if (buf[i] != '\r')
676 fputc(buf[i], stderr);
fb09bf1c 677 return;
678 }
fe50e814 679 from_backend(1, buf, len);
3bdaf79d 680}
681
32874aea 682static void c_write_untrusted(char *buf, int len)
683{
a209e957 684 int i;
685 for (i = 0; i < len; i++) {
32874aea 686 if (buf[i] == '\n')
687 c_write("\r\n", 2);
688 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
689 c_write(buf + i, 1);
a209e957 690 }
691}
692
32874aea 693static void c_write_str(char *buf)
694{
1408a877 695 c_write(buf, strlen(buf));
696}
697
fb09bf1c 698/*
699 * Collect incoming data in the incoming packet buffer.
e5574168 700 * Decipher and verify the packet when it is completely read.
701 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 702 * Update the *data and *datalen variables.
703 * Return the additional nr of bytes needed, or 0 when
704 * a complete packet is available.
705 */
e5574168 706static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 707{
57476f6b 708 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 709
710 crBegin;
374330e2 711
32874aea 712 next_packet:
37508af4 713
fb09bf1c 714 pktin.type = 0;
715 pktin.length = 0;
374330e2 716
57476f6b 717 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 718 while ((*datalen) == 0)
32874aea 719 crReturn(4 - st->i);
57476f6b 720 st->len = (st->len << 8) + **data;
fb09bf1c 721 (*data)++, (*datalen)--;
722 }
374330e2 723
57476f6b 724 st->pad = 8 - (st->len % 8);
725 st->biglen = st->len + st->pad;
726 pktin.length = st->len - 5;
fb09bf1c 727
57476f6b 728 if (pktin.maxlen < st->biglen) {
729 pktin.maxlen = st->biglen;
32874aea 730 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
731 srealloc(pktin.data, st->biglen + APIEXTRA));
fb09bf1c 732 if (!pktin.data)
733 fatalbox("Out of memory");
734 }
374330e2 735
57476f6b 736 st->to_read = st->biglen;
737 st->p = pktin.data;
738 while (st->to_read > 0) {
32874aea 739 st->chunk = st->to_read;
fb09bf1c 740 while ((*datalen) == 0)
57476f6b 741 crReturn(st->to_read);
742 if (st->chunk > (*datalen))
743 st->chunk = (*datalen);
744 memcpy(st->p, *data, st->chunk);
745 *data += st->chunk;
746 *datalen -= st->chunk;
747 st->p += st->chunk;
748 st->to_read -= st->chunk;
fb09bf1c 749 }
374330e2 750
9a3a93a5 751 if (cipher && detect_attack(pktin.data, st->biglen, NULL)) {
752 bombout(("Network attack (CRC compensation) detected!"));
753 crReturn(0);
754 }
755
fb09bf1c 756 if (cipher)
57476f6b 757 cipher->decrypt(pktin.data, st->biglen);
374330e2 758
32874aea 759 st->realcrc = crc32(pktin.data, st->biglen - 4);
760 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
57476f6b 761 if (st->gotcrc != st->realcrc) {
8d5de777 762 bombout(("Incorrect CRC received on packet"));
32874aea 763 crReturn(0);
fb09bf1c 764 }
572f871e 765
4ba9b64b 766 pktin.body = pktin.data + st->pad + 1;
767
768 if (ssh1_compressing) {
769 unsigned char *decompblk;
770 int decomplen;
32874aea 771 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
4ba9b64b 772 &decompblk, &decomplen);
773
774 if (pktin.maxlen < st->pad + decomplen) {
775 pktin.maxlen = st->pad + decomplen;
32874aea 776 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
777 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 778 if (!pktin.data)
779 fatalbox("Out of memory");
780 }
781
32874aea 782 memcpy(pktin.body - 1, decompblk, decomplen);
dcbde236 783 sfree(decompblk);
32874aea 784 pktin.length = decomplen - 1;
4ba9b64b 785 }
786
00db133f 787 pktin.type = pktin.body[-1];
788
789 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
790 pktin.body, pktin.length);
791
e5574168 792 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 793 pktin.type == SSH1_SMSG_STDERR_DATA ||
794 pktin.type == SSH1_MSG_DEBUG ||
795 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
796 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3d63ca2e 797 long stringlen = GET_32BIT(pktin.body);
798 if (stringlen + 4 != pktin.length) {
8d5de777 799 bombout(("Received data packet with bogus string length"));
32874aea 800 crReturn(0);
801 }
fb09bf1c 802 }
803
e5574168 804 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 805 /* log debug message */
806 char buf[80];
3d63ca2e 807 int stringlen = GET_32BIT(pktin.body);
fb09bf1c 808 strcpy(buf, "Remote: ");
3d63ca2e 809 if (stringlen > 70)
810 stringlen = 70;
811 memcpy(buf + 8, pktin.body + 4, stringlen);
812 buf[8 + stringlen] = '\0';
fb09bf1c 813 logevent(buf);
814 goto next_packet;
e5574168 815 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 816 /* do nothing */
817 goto next_packet;
818 }
819
38c4a8da 820 if (pktin.type == SSH1_MSG_DISCONNECT) {
821 /* log reason code in disconnect message */
822 char buf[256];
260f3dec 823 unsigned msglen = GET_32BIT(pktin.body);
824 unsigned nowlen;
38c4a8da 825 strcpy(buf, "Remote sent disconnect: ");
826 nowlen = strlen(buf);
32874aea 827 if (msglen > sizeof(buf) - nowlen - 1)
828 msglen = sizeof(buf) - nowlen - 1;
829 memcpy(buf + nowlen, pktin.body + 4, msglen);
830 buf[nowlen + msglen] = '\0';
247308b5 831 /* logevent(buf); (this is now done within the bombout macro) */
4eb195cc 832 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 833 crReturn(0);
38c4a8da 834 }
835
fb09bf1c 836 crFinish(0);
837}
838
e5574168 839static int ssh2_rdpkt(unsigned char **data, int *datalen)
840{
960e736a 841 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 842
843 crBegin;
844
32874aea 845 next_packet:
e5574168 846 pktin.type = 0;
847 pktin.length = 0;
960e736a 848 if (sccipher)
32874aea 849 st->cipherblk = sccipher->blksize;
e5574168 850 else
32874aea 851 st->cipherblk = 8;
960e736a 852 if (st->cipherblk < 8)
32874aea 853 st->cipherblk = 8;
960e736a 854
855 if (pktin.maxlen < st->cipherblk) {
856 pktin.maxlen = st->cipherblk;
32874aea 857 pktin.data =
858 (pktin.data ==
859 NULL ? smalloc(st->cipherblk +
860 APIEXTRA) : srealloc(pktin.data,
861 st->cipherblk +
862 APIEXTRA));
e5574168 863 if (!pktin.data)
864 fatalbox("Out of memory");
865 }
866
867 /*
868 * Acquire and decrypt the first block of the packet. This will
869 * contain the length and padding details.
870 */
32874aea 871 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 872 while ((*datalen) == 0)
32874aea 873 crReturn(st->cipherblk - st->i);
960e736a 874 pktin.data[st->i] = *(*data)++;
32874aea 875 (*datalen)--;
e5574168 876 }
4252c9cc 877
e5574168 878 if (sccipher)
32874aea 879 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 880
881 /*
882 * Now get the length and padding figures.
883 */
960e736a 884 st->len = GET_32BIT(pktin.data);
885 st->pad = pktin.data[4];
e5574168 886
887 /*
888 * This enables us to deduce the payload length.
889 */
960e736a 890 st->payload = st->len - st->pad - 1;
e5574168 891
960e736a 892 pktin.length = st->payload + 5;
e5574168 893
894 /*
895 * So now we can work out the total packet length.
896 */
960e736a 897 st->packetlen = st->len + 4;
898 st->maclen = scmac ? scmac->len : 0;
e5574168 899
900 /*
901 * Adjust memory allocation if packet is too big.
902 */
32874aea 903 if (pktin.maxlen < st->packetlen + st->maclen) {
904 pktin.maxlen = st->packetlen + st->maclen;
905 pktin.data =
906 (pktin.data ==
907 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
908 pktin.maxlen
909 +
910 APIEXTRA));
e5574168 911 if (!pktin.data)
912 fatalbox("Out of memory");
913 }
914
915 /*
916 * Read and decrypt the remainder of the packet.
917 */
32874aea 918 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
919 st->i++) {
e5574168 920 while ((*datalen) == 0)
960e736a 921 crReturn(st->packetlen + st->maclen - st->i);
922 pktin.data[st->i] = *(*data)++;
32874aea 923 (*datalen)--;
e5574168 924 }
925 /* Decrypt everything _except_ the MAC. */
926 if (sccipher)
32874aea 927 sccipher->decrypt(pktin.data + st->cipherblk,
928 st->packetlen - st->cipherblk);
e5574168 929
930 /*
931 * Check the MAC.
932 */
32874aea 933 if (scmac
934 && !scmac->verify(pktin.data, st->len + 4,
935 st->incoming_sequence)) {
8d5de777 936 bombout(("Incorrect MAC received on packet"));
32874aea 937 crReturn(0);
8d5de777 938 }
32874aea 939 st->incoming_sequence++; /* whether or not we MACed */
e5574168 940
4ba9b64b 941 /*
942 * Decompress packet payload.
943 */
944 {
945 unsigned char *newpayload;
946 int newlen;
32874aea 947 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
4ba9b64b 948 &newpayload, &newlen)) {
32874aea 949 if (pktin.maxlen < newlen + 5) {
950 pktin.maxlen = newlen + 5;
951 pktin.data =
952 (pktin.data ==
953 NULL ? smalloc(pktin.maxlen +
954 APIEXTRA) : srealloc(pktin.data,
955 pktin.maxlen +
956 APIEXTRA));
4ba9b64b 957 if (!pktin.data)
958 fatalbox("Out of memory");
959 }
960 pktin.length = 5 + newlen;
32874aea 961 memcpy(pktin.data + 5, newpayload, newlen);
dcbde236 962 sfree(newpayload);
4ba9b64b 963 }
964 }
965
e5574168 966 pktin.savedpos = 6;
967 pktin.type = pktin.data[5];
e5574168 968
00db133f 969 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
970 pktin.data+6, pktin.length-6);
971
3d63ca2e 972 switch (pktin.type) {
973 /*
974 * These packets we must handle instantly.
975 */
976 case SSH2_MSG_DISCONNECT:
977 {
978 /* log reason code in disconnect message */
979 char buf[256];
980 int reason = GET_32BIT(pktin.data + 6);
981 unsigned msglen = GET_32BIT(pktin.data + 10);
982 unsigned nowlen;
983 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
984 sprintf(buf, "Received disconnect message (%s)",
985 ssh2_disconnect_reasons[reason]);
986 } else {
987 sprintf(buf, "Received disconnect message (unknown type %d)",
988 reason);
989 }
990 logevent(buf);
991 strcpy(buf, "Disconnection message text: ");
992 nowlen = strlen(buf);
993 if (msglen > sizeof(buf) - nowlen - 1)
994 msglen = sizeof(buf) - nowlen - 1;
995 memcpy(buf + nowlen, pktin.data + 14, msglen);
996 buf[nowlen + msglen] = '\0';
997 logevent(buf);
998 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
999 reason,
1000 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1001 ssh2_disconnect_reasons[reason] : "unknown",
1002 buf+nowlen));
1003 crReturn(0);
1004 }
1005 break;
1006 case SSH2_MSG_IGNORE:
1007 goto next_packet;
1008 case SSH2_MSG_DEBUG:
1009 {
1010 /* log the debug message */
1011 char buf[512];
1012 /* int display = pktin.body[6]; */
1013 int stringlen = GET_32BIT(pktin.data+7);
1014 int prefix;
1015 strcpy(buf, "Remote debug message: ");
1016 prefix = strlen(buf);
1017 if (stringlen > sizeof(buf)-prefix-1)
1018 stringlen = sizeof(buf)-prefix-1;
1019 memcpy(buf + prefix, pktin.data + 11, stringlen);
1020 buf[prefix + stringlen] = '\0';
1021 logevent(buf);
38c4a8da 1022 }
3d63ca2e 1023 goto next_packet; /* FIXME: print the debug message */
1024
1025 /*
1026 * These packets we need do nothing about here.
1027 */
1028 case SSH2_MSG_UNIMPLEMENTED:
1029 case SSH2_MSG_SERVICE_REQUEST:
1030 case SSH2_MSG_SERVICE_ACCEPT:
1031 case SSH2_MSG_KEXINIT:
1032 case SSH2_MSG_NEWKEYS:
1033 case SSH2_MSG_KEXDH_INIT:
1034 case SSH2_MSG_KEXDH_REPLY:
1035 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1036 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1037 case SSH2_MSG_KEX_DH_GEX_INIT:
1038 case SSH2_MSG_KEX_DH_GEX_REPLY:
1039 case SSH2_MSG_USERAUTH_REQUEST:
1040 case SSH2_MSG_USERAUTH_FAILURE:
1041 case SSH2_MSG_USERAUTH_SUCCESS:
1042 case SSH2_MSG_USERAUTH_BANNER:
1043 case SSH2_MSG_USERAUTH_PK_OK:
1044 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1045 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1046 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1047 case SSH2_MSG_GLOBAL_REQUEST:
1048 case SSH2_MSG_REQUEST_SUCCESS:
1049 case SSH2_MSG_REQUEST_FAILURE:
1050 case SSH2_MSG_CHANNEL_OPEN:
1051 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1052 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1053 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1054 case SSH2_MSG_CHANNEL_DATA:
1055 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1056 case SSH2_MSG_CHANNEL_EOF:
1057 case SSH2_MSG_CHANNEL_CLOSE:
1058 case SSH2_MSG_CHANNEL_REQUEST:
1059 case SSH2_MSG_CHANNEL_SUCCESS:
1060 case SSH2_MSG_CHANNEL_FAILURE:
1061 break;
1062
1063 /*
1064 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1065 */
1066 default:
1067 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
1068 ssh2_pkt_adduint32(st->incoming_sequence - 1);
1069 ssh2_pkt_send();
1070 break;
38c4a8da 1071 }
1072
e5574168 1073 crFinish(0);
1074}
1075
32874aea 1076static void ssh1_pktout_size(int len)
1077{
374330e2 1078 int pad, biglen;
1079
1080 len += 5; /* type and CRC */
32874aea 1081 pad = 8 - (len % 8);
374330e2 1082 biglen = len + pad;
1083
32874aea 1084 pktout.length = len - 5;
374330e2 1085 if (pktout.maxlen < biglen) {
1086 pktout.maxlen = biglen;
8f203108 1087#ifdef MSCRYPTOAPI
fb09bf1c 1088 /* Allocate enough buffer space for extra block
8f203108 1089 * for MS CryptEncrypt() */
32874aea 1090 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
1091 srealloc(pktout.data, biglen + 12));
8f203108 1092#else
32874aea 1093 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
1094 srealloc(pktout.data, biglen + 4));
8f203108 1095#endif
374330e2 1096 if (!pktout.data)
1097 fatalbox("Out of memory");
1098 }
32874aea 1099 pktout.body = pktout.data + 4 + pad + 1;
4ba9b64b 1100}
374330e2 1101
32874aea 1102static void s_wrpkt_start(int type, int len)
1103{
4ba9b64b 1104 ssh1_pktout_size(len);
374330e2 1105 pktout.type = type;
374330e2 1106}
1107
32874aea 1108static int s_wrpkt_prepare(void)
1109{
374330e2 1110 int pad, len, biglen, i;
1111 unsigned long crc;
1112
4ba9b64b 1113 pktout.body[-1] = pktout.type;
1114
00db133f 1115 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1116 pktout.body, pktout.length);
1117
4ba9b64b 1118 if (ssh1_compressing) {
1119 unsigned char *compblk;
1120 int complen;
32874aea 1121 zlib_compress_block(pktout.body - 1, pktout.length + 1,
4ba9b64b 1122 &compblk, &complen);
32874aea 1123 ssh1_pktout_size(complen - 1);
1124 memcpy(pktout.body - 1, compblk, complen);
dcbde236 1125 sfree(compblk);
4ba9b64b 1126 }
1127
374330e2 1128 len = pktout.length + 5; /* type and CRC */
32874aea 1129 pad = 8 - (len % 8);
374330e2 1130 biglen = len + pad;
1131
32874aea 1132 for (i = 0; i < pad; i++)
1133 pktout.data[i + 4] = random_byte();
1134 crc = crc32(pktout.data + 4, biglen - 4);
1135 PUT_32BIT(pktout.data + biglen, crc);
fb09bf1c 1136 PUT_32BIT(pktout.data, len);
374330e2 1137
1138 if (cipher)
32874aea 1139 cipher->encrypt(pktout.data + 4, biglen);
374330e2 1140
32874aea 1141 return biglen + 4;
39065bed 1142}
1143
32874aea 1144static void s_wrpkt(void)
1145{
5471d09a 1146 int len, backlog;
39065bed 1147 len = s_wrpkt_prepare();
5471d09a 1148 backlog = sk_write(s, pktout.data, len);
1149 if (backlog > SSH_MAX_BACKLOG)
1150 ssh_throttle_all(1, backlog);
39065bed 1151}
1152
32874aea 1153static void s_wrpkt_defer(void)
1154{
39065bed 1155 int len;
1156 len = s_wrpkt_prepare();
1157 if (deferred_len + len > deferred_size) {
32874aea 1158 deferred_size = deferred_len + len + 128;
1159 deferred_send_data = srealloc(deferred_send_data, deferred_size);
39065bed 1160 }
32874aea 1161 memcpy(deferred_send_data + deferred_len, pktout.data, len);
39065bed 1162 deferred_len += len;
374330e2 1163}
1164
fb09bf1c 1165/*
39065bed 1166 * Construct a packet with the specified contents.
fb09bf1c 1167 */
39065bed 1168static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1169{
fb09bf1c 1170 unsigned char *p, *argp, argchar;
1171 unsigned long argint;
1172 int pktlen, argtype, arglen;
7cca0d81 1173 Bignum bn;
fb09bf1c 1174
1175 pktlen = 0;
39065bed 1176 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1177 switch (argtype) {
1178 case PKT_INT:
39065bed 1179 (void) va_arg(ap1, int);
fb09bf1c 1180 pktlen += 4;
1181 break;
1182 case PKT_CHAR:
39065bed 1183 (void) va_arg(ap1, char);
fb09bf1c 1184 pktlen++;
1185 break;
1186 case PKT_DATA:
39065bed 1187 (void) va_arg(ap1, unsigned char *);
1188 arglen = va_arg(ap1, int);
fb09bf1c 1189 pktlen += arglen;
1190 break;
1191 case PKT_STR:
39065bed 1192 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1193 arglen = strlen(argp);
1194 pktlen += 4 + arglen;
1195 break;
7cca0d81 1196 case PKT_BIGNUM:
39065bed 1197 bn = va_arg(ap1, Bignum);
32874aea 1198 pktlen += ssh1_bignum_length(bn);
7cca0d81 1199 break;
fb09bf1c 1200 default:
1201 assert(0);
1202 }
1203 }
fb09bf1c 1204
1205 s_wrpkt_start(pkttype, pktlen);
1206 p = pktout.body;
1207
39065bed 1208 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1209 switch (argtype) {
1210 case PKT_INT:
39065bed 1211 argint = va_arg(ap2, int);
fb09bf1c 1212 PUT_32BIT(p, argint);
1213 p += 4;
1214 break;
1215 case PKT_CHAR:
39065bed 1216 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1217 *p = argchar;
1218 p++;
1219 break;
1220 case PKT_DATA:
39065bed 1221 argp = va_arg(ap2, unsigned char *);
1222 arglen = va_arg(ap2, int);
fb09bf1c 1223 memcpy(p, argp, arglen);
1224 p += arglen;
1225 break;
1226 case PKT_STR:
39065bed 1227 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1228 arglen = strlen(argp);
1229 PUT_32BIT(p, arglen);
1230 memcpy(p + 4, argp, arglen);
1231 p += 4 + arglen;
1232 break;
7cca0d81 1233 case PKT_BIGNUM:
39065bed 1234 bn = va_arg(ap2, Bignum);
32874aea 1235 p += ssh1_write_bignum(p, bn);
7cca0d81 1236 break;
fb09bf1c 1237 }
1238 }
39065bed 1239}
fb09bf1c 1240
32874aea 1241static void send_packet(int pkttype, ...)
1242{
39065bed 1243 va_list ap1, ap2;
1244 va_start(ap1, pkttype);
1245 va_start(ap2, pkttype);
1246 construct_packet(pkttype, ap1, ap2);
fb09bf1c 1247 s_wrpkt();
1248}
1249
32874aea 1250static void defer_packet(int pkttype, ...)
1251{
39065bed 1252 va_list ap1, ap2;
1253 va_start(ap1, pkttype);
1254 va_start(ap2, pkttype);
1255 construct_packet(pkttype, ap1, ap2);
1256 s_wrpkt_defer();
1257}
1258
32874aea 1259static int ssh_versioncmp(char *a, char *b)
1260{
9697bfd2 1261 char *ae, *be;
1262 unsigned long av, bv;
1263
43aa02a7 1264 av = strtoul(a, &ae, 10);
1265 bv = strtoul(b, &be, 10);
32874aea 1266 if (av != bv)
1267 return (av < bv ? -1 : +1);
1268 if (*ae == '.')
1269 ae++;
1270 if (*be == '.')
1271 be++;
43aa02a7 1272 av = strtoul(ae, &ae, 10);
1273 bv = strtoul(be, &be, 10);
32874aea 1274 if (av != bv)
1275 return (av < bv ? -1 : +1);
9697bfd2 1276 return 0;
1277}
1278
e5574168 1279
1280/*
a92dd380 1281 * Utility routines for putting an SSH-protocol `string' and
1282 * `uint32' into a SHA state.
e5574168 1283 */
1284#include <stdio.h>
32874aea 1285static void sha_string(SHA_State * s, void *str, int len)
1286{
e5574168 1287 unsigned char lenblk[4];
e5574168 1288 PUT_32BIT(lenblk, len);
e5574168 1289 SHA_Bytes(s, lenblk, 4);
e5574168 1290 SHA_Bytes(s, str, len);
1291}
1292
32874aea 1293static void sha_uint32(SHA_State * s, unsigned i)
1294{
a92dd380 1295 unsigned char intblk[4];
1296 PUT_32BIT(intblk, i);
1297 SHA_Bytes(s, intblk, 4);
1298}
1299
7cca0d81 1300/*
1301 * SSH2 packet construction functions.
1302 */
32874aea 1303static void ssh2_pkt_ensure(int length)
1304{
783415f8 1305 if (pktout.maxlen < length) {
32874aea 1306 pktout.maxlen = length + 256;
1307 pktout.data =
1308 (pktout.data ==
1309 NULL ? smalloc(pktout.maxlen +
1310 APIEXTRA) : srealloc(pktout.data,
1311 pktout.maxlen +
1312 APIEXTRA));
1313 if (!pktout.data)
1314 fatalbox("Out of memory");
7cca0d81 1315 }
783415f8 1316}
32874aea 1317static void ssh2_pkt_adddata(void *data, int len)
1318{
783415f8 1319 pktout.length += len;
1320 ssh2_pkt_ensure(pktout.length);
32874aea 1321 memcpy(pktout.data + pktout.length - len, data, len);
7cca0d81 1322}
32874aea 1323static void ssh2_pkt_addbyte(unsigned char byte)
1324{
7cca0d81 1325 ssh2_pkt_adddata(&byte, 1);
1326}
32874aea 1327static void ssh2_pkt_init(int pkt_type)
1328{
7cca0d81 1329 pktout.length = 5;
32874aea 1330 ssh2_pkt_addbyte((unsigned char) pkt_type);
7cca0d81 1331}
32874aea 1332static void ssh2_pkt_addbool(unsigned char value)
1333{
7cca0d81 1334 ssh2_pkt_adddata(&value, 1);
1335}
32874aea 1336static void ssh2_pkt_adduint32(unsigned long value)
1337{
7cca0d81 1338 unsigned char x[4];
1339 PUT_32BIT(x, value);
1340 ssh2_pkt_adddata(x, 4);
1341}
32874aea 1342static void ssh2_pkt_addstring_start(void)
1343{
7cca0d81 1344 ssh2_pkt_adduint32(0);
1345 pktout.savedpos = pktout.length;
1346}
32874aea 1347static void ssh2_pkt_addstring_str(char *data)
1348{
7cca0d81 1349 ssh2_pkt_adddata(data, strlen(data));
1350 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1351 pktout.length - pktout.savedpos);
7cca0d81 1352}
32874aea 1353static void ssh2_pkt_addstring_data(char *data, int len)
1354{
7cca0d81 1355 ssh2_pkt_adddata(data, len);
1356 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1357 pktout.length - pktout.savedpos);
7cca0d81 1358}
32874aea 1359static void ssh2_pkt_addstring(char *data)
1360{
7cca0d81 1361 ssh2_pkt_addstring_start();
1362 ssh2_pkt_addstring_str(data);
1363}
32874aea 1364static char *ssh2_mpint_fmt(Bignum b, int *len)
1365{
7cca0d81 1366 unsigned char *p;
32874aea 1367 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1368 p = smalloc(n + 1);
7cca0d81 1369 if (!p)
32874aea 1370 fatalbox("out of memory");
7cca0d81 1371 p[0] = 0;
3709bfe9 1372 for (i = 1; i <= n; i++)
32874aea 1373 p[i] = bignum_byte(b, n - i);
7cca0d81 1374 i = 0;
32874aea 1375 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1376 i++;
1377 memmove(p, p + i, n + 1 - i);
1378 *len = n + 1 - i;
7cca0d81 1379 return p;
1380}
32874aea 1381static void ssh2_pkt_addmp(Bignum b)
1382{
7cca0d81 1383 unsigned char *p;
1384 int len;
1385 p = ssh2_mpint_fmt(b, &len);
1386 ssh2_pkt_addstring_start();
1387 ssh2_pkt_addstring_data(p, len);
dcbde236 1388 sfree(p);
7cca0d81 1389}
b185170a 1390
1391/*
1392 * Construct an SSH2 final-form packet: compress it, encrypt it,
1393 * put the MAC on it. Final packet, ready to be sent, is stored in
1394 * pktout.data. Total length is returned.
1395 */
32874aea 1396static int ssh2_pkt_construct(void)
1397{
7cca0d81 1398 int cipherblk, maclen, padding, i;
1399 static unsigned long outgoing_sequence = 0;
1400
00db133f 1401 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1402 pktout.data + 6, pktout.length - 6);
1403
7cca0d81 1404 /*
4ba9b64b 1405 * Compress packet payload.
1406 */
4ba9b64b 1407 {
1408 unsigned char *newpayload;
1409 int newlen;
32874aea 1410 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
4ba9b64b 1411 &newpayload, &newlen)) {
1412 pktout.length = 5;
1413 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1414 sfree(newpayload);
4ba9b64b 1415 }
1416 }
1417
1418 /*
7cca0d81 1419 * Add padding. At least four bytes, and must also bring total
1420 * length (minus MAC) up to a multiple of the block size.
1421 */
32874aea 1422 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1423 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1424 padding = 4;
32874aea 1425 padding +=
1426 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1427 maclen = csmac ? csmac->len : 0;
1428 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1429 pktout.data[4] = padding;
1430 for (i = 0; i < padding; i++)
32874aea 1431 pktout.data[pktout.length + i] = random_byte();
7cca0d81 1432 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1433 if (csmac)
32874aea 1434 csmac->generate(pktout.data, pktout.length + padding,
1435 outgoing_sequence);
1436 outgoing_sequence++; /* whether or not we MACed */
7cca0d81 1437
7cca0d81 1438 if (cscipher)
32874aea 1439 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1440
b185170a 1441 /* Ready-to-send packet starts at pktout.data. We return length. */
1442 return pktout.length + padding + maclen;
1443}
1444
1445/*
1446 * Construct and send an SSH2 packet immediately.
1447 */
32874aea 1448static void ssh2_pkt_send(void)
1449{
5471d09a 1450 int len;
1451 int backlog;
1452 len = ssh2_pkt_construct();
1453 backlog = sk_write(s, pktout.data, len);
1454 if (backlog > SSH_MAX_BACKLOG)
1455 ssh_throttle_all(1, backlog);
b185170a 1456}
1457
1458/*
1459 * Construct an SSH2 packet and add it to a deferred data block.
1460 * Useful for sending multiple packets in a single sk_write() call,
1461 * to prevent a traffic-analysing listener from being able to work
1462 * out the length of any particular packet (such as the password
1463 * packet).
1464 *
1465 * Note that because SSH2 sequence-numbers its packets, this can
1466 * NOT be used as an m4-style `defer' allowing packets to be
1467 * constructed in one order and sent in another.
1468 */
32874aea 1469static void ssh2_pkt_defer(void)
1470{
b185170a 1471 int len = ssh2_pkt_construct();
1472 if (deferred_len + len > deferred_size) {
32874aea 1473 deferred_size = deferred_len + len + 128;
1474 deferred_send_data = srealloc(deferred_send_data, deferred_size);
b185170a 1475 }
32874aea 1476 memcpy(deferred_send_data + deferred_len, pktout.data, len);
b185170a 1477 deferred_len += len;
1478}
1479
1480/*
1481 * Send the whole deferred data block constructed by
39065bed 1482 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1483 */
32874aea 1484static void ssh_pkt_defersend(void)
1485{
5471d09a 1486 int backlog;
1487 backlog = sk_write(s, deferred_send_data, deferred_len);
b185170a 1488 deferred_len = deferred_size = 0;
1489 sfree(deferred_send_data);
1490 deferred_send_data = NULL;
5471d09a 1491 if (backlog > SSH_MAX_BACKLOG)
1492 ssh_throttle_all(1, backlog);
7cca0d81 1493}
1494
1495#if 0
32874aea 1496void bndebug(char *string, Bignum b)
1497{
7cca0d81 1498 unsigned char *p;
1499 int i, len;
1500 p = ssh2_mpint_fmt(b, &len);
1501 debug(("%s", string));
1502 for (i = 0; i < len; i++)
32874aea 1503 debug((" %02x", p[i]));
765c4200 1504 debug(("\n"));
dcbde236 1505 sfree(p);
7cca0d81 1506}
1507#endif
1508
32874aea 1509static void sha_mpint(SHA_State * s, Bignum b)
1510{
7cca0d81 1511 unsigned char *p;
1512 int len;
1513 p = ssh2_mpint_fmt(b, &len);
1514 sha_string(s, p, len);
dcbde236 1515 sfree(p);
7cca0d81 1516}
1517
1518/*
1519 * SSH2 packet decode functions.
1520 */
32874aea 1521static unsigned long ssh2_pkt_getuint32(void)
1522{
7cca0d81 1523 unsigned long value;
1524 if (pktin.length - pktin.savedpos < 4)
32874aea 1525 return 0; /* arrgh, no way to decline (FIXME?) */
1526 value = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1527 pktin.savedpos += 4;
1528 return value;
1529}
32874aea 1530static int ssh2_pkt_getbool(void)
1531{
65a22376 1532 unsigned long value;
1533 if (pktin.length - pktin.savedpos < 1)
32874aea 1534 return 0; /* arrgh, no way to decline (FIXME?) */
65a22376 1535 value = pktin.data[pktin.savedpos] != 0;
1536 pktin.savedpos++;
1537 return value;
1538}
32874aea 1539static void ssh2_pkt_getstring(char **p, int *length)
1540{
7cca0d81 1541 *p = NULL;
45068b27 1542 *length = 0;
7cca0d81 1543 if (pktin.length - pktin.savedpos < 4)
32874aea 1544 return;
1545 *length = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1546 pktin.savedpos += 4;
1547 if (pktin.length - pktin.savedpos < *length)
32874aea 1548 return;
1549 *p = pktin.data + pktin.savedpos;
7cca0d81 1550 pktin.savedpos += *length;
1551}
32874aea 1552static Bignum ssh2_pkt_getmp(void)
1553{
7cca0d81 1554 char *p;
3709bfe9 1555 int length;
7cca0d81 1556 Bignum b;
1557
1558 ssh2_pkt_getstring(&p, &length);
1559 if (!p)
32874aea 1560 return NULL;
8d5de777 1561 if (p[0] & 0x80) {
32874aea 1562 bombout(("internal error: Can't handle negative mpints"));
1563 return NULL;
8d5de777 1564 }
3709bfe9 1565 b = bignum_from_bytes(p, length);
7cca0d81 1566 return b;
1567}
1568
7d503c31 1569/*
1dd353b5 1570 * Helper function to add an SSH2 signature blob to a packet.
1571 * Expects to be shown the public key blob as well as the signature
1572 * blob. Normally works just like ssh2_pkt_addstring, but will
1573 * fiddle with the signature packet if necessary for
1574 * BUG_SSH2_RSA_PADDING.
1575 */
1576static void ssh2_add_sigblob(void *pkblob_v, int pkblob_len,
1577 void *sigblob_v, int sigblob_len)
1578{
1579 unsigned char *pkblob = (unsigned char *)pkblob_v;
1580 unsigned char *sigblob = (unsigned char *)sigblob_v;
1581
1582 /* dmemdump(pkblob, pkblob_len); */
1583 /* dmemdump(sigblob, sigblob_len); */
1584
1585 /*
1586 * See if this is in fact an ssh-rsa signature and a buggy
1587 * server; otherwise we can just do this the easy way.
1588 */
1589 if ((ssh_remote_bugs & BUG_SSH2_RSA_PADDING) &&
1590 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1591 int pos, len, siglen;
1592
1593 /*
1594 * Find the byte length of the modulus.
1595 */
1596
1597 pos = 4+7; /* skip over "ssh-rsa" */
1598 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1599 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1600 pos += 4; /* find modulus itself */
1601 while (len > 0 && pkblob[pos] == 0)
1602 len--, pos++;
1603 /* debug(("modulus length is %d\n", len)); */
1604
1605 /*
1606 * Now find the signature integer.
1607 */
1608 pos = 4+7; /* skip over "ssh-rsa" */
1609 siglen = GET_32BIT(sigblob+pos);
1610 /* debug(("signature length is %d\n", siglen)); */
1611
1612 if (len != siglen) {
1613 unsigned char newlen[4];
1614 ssh2_pkt_addstring_start();
1615 ssh2_pkt_addstring_data(sigblob, pos);
1616 /* dmemdump(sigblob, pos); */
1617 pos += 4; /* point to start of actual sig */
1618 PUT_32BIT(newlen, len);
1619 ssh2_pkt_addstring_data(newlen, 4);
1620 /* dmemdump(newlen, 4); */
1621 newlen[0] = 0;
1622 while (len-- > siglen) {
1623 ssh2_pkt_addstring_data(newlen, 1);
1624 /* dmemdump(newlen, 1); */
1625 }
1626 ssh2_pkt_addstring_data(sigblob+pos, siglen);
1627 /* dmemdump(sigblob+pos, siglen); */
1628 return;
1629 }
1630
1631 /* Otherwise fall through and do it the easy way. */
1632 }
1633
1634 ssh2_pkt_addstring_start();
1635 ssh2_pkt_addstring_data(sigblob, sigblob_len);
1636}
1637
1638/*
7d503c31 1639 * Examine the remote side's version string and compare it against
1640 * a list of known buggy implementations.
1641 */
32874aea 1642static void ssh_detect_bugs(char *vstring)
1643{
1644 char *imp; /* pointer to implementation part */
7d503c31 1645 imp = vstring;
1646 imp += strcspn(imp, "-");
bd358db1 1647 if (*imp) imp++;
7d503c31 1648 imp += strcspn(imp, "-");
bd358db1 1649 if (*imp) imp++;
7d503c31 1650
1651 ssh_remote_bugs = 0;
1652
1653 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
32874aea 1654 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
bd358db1 1655 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
32874aea 1656 /*
1657 * These versions don't support SSH1_MSG_IGNORE, so we have
1658 * to use a different defence against password length
1659 * sniffing.
1660 */
1661 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1662 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1663 }
1664
bd358db1 1665 if (!strcmp(imp, "Cisco-1.25")) {
1666 /*
1667 * These versions need a plain password sent; they can't
1668 * handle having a null and a random length of data after
1669 * the password.
1670 */
1671 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1672 logevent("We believe remote version needs a plain SSH1 password");
1673 }
1674
0df73905 1675 if (!strcmp(imp, "Cisco-1.25")) {
1676 /*
1677 * These versions apparently have no clue whatever about
1678 * RSA authentication and will panic and die if they see
1679 * an AUTH_RSA message.
1680 */
1681 ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
1682 logevent("We believe remote version can't handle RSA authentication");
1683 }
1684
7d503c31 1685 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
32874aea 1686 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1687 !strncmp(imp, "2.1 ", 4)) {
1688 /*
1689 * These versions have the HMAC bug.
1690 */
1691 ssh_remote_bugs |= BUG_SSH2_HMAC;
1692 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1693 }
1dd353b5 1694
1695 if ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1696 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')) {
1697 /*
1698 * These versions have the SSH2 RSA padding bug.
1699 */
1700 ssh_remote_bugs |= BUG_SSH2_RSA_PADDING;
1701 logevent("We believe remote version has SSH2 RSA padding bug");
1702 }
7d503c31 1703}
1704
32874aea 1705static int do_ssh_init(unsigned char c)
1706{
2d466ffd 1707 static int vslen;
8df7a775 1708 static char version[10];
50526e47 1709 static char *vstring;
1710 static int vstrsize;
1711 static char *vlog;
8df7a775 1712 static int i;
374330e2 1713
8df7a775 1714 crBegin;
1715
1716 /* Search for the string "SSH-" in the input. */
374330e2 1717 i = 0;
8df7a775 1718 while (1) {
1719 static const int transS[] = { 1, 2, 2, 1 };
1720 static const int transH[] = { 0, 0, 3, 0 };
1721 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1722 if (c == 'S')
1723 i = transS[i];
1724 else if (c == 'H')
1725 i = transH[i];
1726 else if (c == '-')
1727 i = transminus[i];
1728 else
1729 i = 0;
8df7a775 1730 if (i < 0)
1731 break;
1732 crReturn(1); /* get another character */
374330e2 1733 }
8df7a775 1734
50526e47 1735 vstrsize = 16;
bd358db1 1736 vstring = smalloc(vstrsize);
c5e9c988 1737 strcpy(vstring, "SSH-");
50526e47 1738 vslen = 4;
374330e2 1739 i = 0;
1740 while (1) {
8df7a775 1741 crReturn(1); /* get another char */
32874aea 1742 if (vslen >= vstrsize - 1) {
1743 vstrsize += 16;
1744 vstring = srealloc(vstring, vstrsize);
1745 }
1746 vstring[vslen++] = c;
374330e2 1747 if (i >= 0) {
1748 if (c == '-') {
1749 version[i] = '\0';
1750 i = -1;
32874aea 1751 } else if (i < sizeof(version) - 1)
374330e2 1752 version[i++] = c;
32874aea 1753 } else if (c == '\n')
374330e2 1754 break;
1755 }
1756
db7d555c 1757 ssh_agentfwd_enabled = FALSE;
960e736a 1758 rdpkt2_state.incoming_sequence = 0;
1759
50526e47 1760 vstring[vslen] = 0;
9275ca8a 1761 vlog = smalloc(20 + vslen);
bd358db1 1762 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
c5e9c988 1763 sprintf(vlog, "Server version: %s", vstring);
c5e9c988 1764 logevent(vlog);
bd358db1 1765 ssh_detect_bugs(vstring);
9275ca8a 1766 sfree(vlog);
c5e9c988 1767
adf799dd 1768 /*
1769 * Server version "1.99" means we can choose whether we use v1
1770 * or v2 protocol. Choice is based on cfg.sshprot.
1771 */
1772 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
32874aea 1773 /*
1774 * This is a v2 server. Begin v2 protocol.
1775 */
1776 char verstring[80], vlog[100];
1777 sprintf(verstring, "SSH-2.0-%s", sshver);
1778 SHA_Init(&exhashbase);
1779 /*
1780 * Hash our version string and their version string.
1781 */
1782 sha_string(&exhashbase, verstring, strlen(verstring));
1783 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1784 sprintf(vlog, "We claim version: %s", verstring);
1785 logevent(vlog);
1786 strcat(verstring, "\n");
1787 logevent("Using SSH protocol version 2");
1788 sk_write(s, verstring, strlen(verstring));
1789 ssh_protocol = ssh2_protocol;
1790 ssh_version = 2;
1791 s_rdpkt = ssh2_rdpkt;
e5574168 1792 } else {
32874aea 1793 /*
1794 * This is a v1 server. Begin v1 protocol.
1795 */
1796 char verstring[80], vlog[100];
1797 sprintf(verstring, "SSH-%s-%s",
1798 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1799 sshver);
1800 sprintf(vlog, "We claim version: %s", verstring);
1801 logevent(vlog);
1802 strcat(verstring, "\n");
759712a6 1803
1804 if (cfg.sshprot == 3) {
1805 bombout(("SSH protocol version 2 required by user but not provided by server"));
1806 crReturn(0);
1807 }
1808
32874aea 1809 logevent("Using SSH protocol version 1");
1810 sk_write(s, verstring, strlen(verstring));
1811 ssh_protocol = ssh1_protocol;
1812 ssh_version = 1;
1813 s_rdpkt = ssh1_rdpkt;
e5574168 1814 }
3687d221 1815 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1816
50526e47 1817 sfree(vstring);
50526e47 1818
8df7a775 1819 crFinish(0);
1820}
1821
1822static void ssh_gotdata(unsigned char *data, int datalen)
1823{
1824 crBegin;
1825
1826 /*
1827 * To begin with, feed the characters one by one to the
1828 * protocol initialisation / selection function do_ssh_init().
1829 * When that returns 0, we're done with the initial greeting
1830 * exchange and can move on to packet discipline.
1831 */
1832 while (1) {
1833 int ret;
1834 if (datalen == 0)
1835 crReturnV; /* more data please */
1836 ret = do_ssh_init(*data);
32874aea 1837 data++;
1838 datalen--;
8df7a775 1839 if (ret == 0)
1840 break;
1841 }
1842
1843 /*
1844 * We emerge from that loop when the initial negotiation is
1845 * over and we have selected an s_rdpkt function. Now pass
1846 * everything to s_rdpkt, and then pass the resulting packets
1847 * to the proper protocol handler.
1848 */
1849 if (datalen == 0)
1850 crReturnV;
1851 while (1) {
1852 while (datalen > 0) {
32874aea 1853 if (s_rdpkt(&data, &datalen) == 0) {
e14d0f19 1854 if (ssh_state == SSH_STATE_CLOSED) {
1855 return;
1856 }
8df7a775 1857 ssh_protocol(NULL, 0, 1);
1858 if (ssh_state == SSH_STATE_CLOSED) {
1859 return;
1860 }
1861 }
1862 }
1863 crReturnV;
1864 }
1865 crFinishV;
1866}
1867
32874aea 1868static int ssh_closing(Plug plug, char *error_msg, int error_code,
1869 int calling_back)
1870{
7e78000d 1871 ssh_state = SSH_STATE_CLOSED;
f3ab576e 1872 if (s) {
1873 sk_close(s);
1874 s = NULL;
1875 }
7e78000d 1876 if (error_msg) {
32874aea 1877 /* A socket error has occurred. */
247308b5 1878 logevent(error_msg);
32874aea 1879 connection_fatal(error_msg);
7e78000d 1880 } else {
1881 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1882 }
7e78000d 1883 return 0;
1884}
1885
32874aea 1886static int ssh_receive(Plug plug, int urgent, char *data, int len)
1887{
1888 ssh_gotdata(data, len);
3257deae 1889 if (ssh_state == SSH_STATE_CLOSED) {
32874aea 1890 if (s) {
1891 sk_close(s);
1892 s = NULL;
1893 }
1894 return 0;
3257deae 1895 }
fef97f43 1896 return 1;
374330e2 1897}
1898
5471d09a 1899static void ssh_sent(Plug plug, int bufsize)
1900{
1901 /*
1902 * If the send backlog on the SSH socket itself clears, we
1903 * should unthrottle the whole world if it was throttled.
1904 */
1905 if (bufsize < SSH_MAX_BACKLOG)
1906 ssh_throttle_all(0, bufsize);
1907}
1908
fb09bf1c 1909/*
8df7a775 1910 * Connect to specified host and port.
1911 * Returns an error message, or NULL on success.
6e1ebb76 1912 * Also places the canonical host name into `realhost'. It must be
1913 * freed by the caller.
8df7a775 1914 */
2184a5d9 1915static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
8df7a775 1916{
7e78000d 1917 static struct plug_function_table fn_table = {
1918 ssh_closing,
5471d09a 1919 ssh_receive,
1920 ssh_sent,
1921 NULL
7e78000d 1922 }, *fn_table_ptr = &fn_table;
1923
8df7a775 1924 SockAddr addr;
1925 char *err;
1926#ifdef FWHACK
1927 char *FWhost;
1928 int FWport;
1929#endif
1930
32874aea 1931 savedhost = smalloc(1 + strlen(host));
8df7a775 1932 if (!savedhost)
1933 fatalbox("Out of memory");
1934 strcpy(savedhost, host);
1935
1936 if (port < 0)
1937 port = 22; /* default ssh port */
1938 savedport = port;
1939
1940#ifdef FWHACK
1941 FWhost = host;
1942 FWport = port;
1943 host = FWSTR;
1944 port = 23;
1945#endif
1946
1947 /*
1948 * Try to find host.
1949 */
3ad9d396 1950 {
1951 char buf[200];
1952 sprintf(buf, "Looking up host \"%.170s\"", host);
1953 logevent(buf);
1954 }
8df7a775 1955 addr = sk_namelookup(host, realhost);
32874aea 1956 if ((err = sk_addr_error(addr)))
8df7a775 1957 return err;
1958
1959#ifdef FWHACK
6e1ebb76 1960 *realhost = strdup(FWhost);
8df7a775 1961#endif
1962
1963 /*
1964 * Open socket.
1965 */
3ad9d396 1966 {
1967 char buf[200], addrbuf[100];
1968 sk_getaddr(addr, addrbuf, 100);
1969 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1970 logevent(buf);
1971 }
8eebd221 1972 s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
67c4ba2e 1973 if ((err = sk_socket_error(s))) {
1974 s = NULL;
8df7a775 1975 return err;
67c4ba2e 1976 }
8df7a775 1977
1978#ifdef FWHACK
1979 sk_write(s, "connect ", 8);
1980 sk_write(s, FWhost, strlen(FWhost));
1981 {
1982 char buf[20];
1983 sprintf(buf, " %d\n", FWport);
1984 sk_write(s, buf, strlen(buf));
1985 }
1986#endif
1987
1988 return NULL;
1989}
1990
1991/*
5471d09a 1992 * Throttle or unthrottle the SSH connection.
1993 */
1994static void ssh1_throttle(int adjust)
1995{
1996 int old_count = ssh1_throttle_count;
1997 ssh1_throttle_count += adjust;
1998 assert(ssh1_throttle_count >= 0);
1999 if (ssh1_throttle_count && !old_count) {
2000 sk_set_frozen(s, 1);
2001 } else if (!ssh1_throttle_count && old_count) {
2002 sk_set_frozen(s, 0);
2003 }
2004}
2005
2006/*
2007 * Throttle or unthrottle _all_ local data streams (for when sends
2008 * on the SSH connection itself back up).
2009 */
2010static void ssh_throttle_all(int enable, int bufsize)
2011{
2012 int i;
2013 struct ssh_channel *c;
2014
2015 if (enable == ssh_throttled_all)
2016 return;
2017 ssh_throttled_all = enable;
2018 ssh_overall_bufsize = bufsize;
2019 if (!ssh_channels)
2020 return;
2021 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
2022 switch (c->type) {
2023 case CHAN_MAINSESSION:
2024 /*
2025 * This is treated separately, outside the switch.
2026 */
2027 break;
2028 case CHAN_X11:
2029 x11_override_throttle(c->u.x11.s, enable);
2030 break;
2031 case CHAN_AGENT:
2032 /* Agent channels require no buffer management. */
2033 break;
2034 case CHAN_SOCKDATA:
2035 pfd_override_throttle(c->u.x11.s, enable);
2036 break;
2037 }
2038 }
2039}
2040
2041/*
fb09bf1c 2042 * Handle the key exchange and user authentication phases.
2043 */
e5574168 2044static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 2045{
2d466ffd 2046 int i, j;
2047 static int len;
2048 static unsigned char *rsabuf, *keystr1, *keystr2;
374330e2 2049 unsigned char cookie[8];
2050 struct RSAKey servkey, hostkey;
2051 struct MD5Context md5c;
ccbfb941 2052 static unsigned long supported_ciphers_mask, supported_auths_mask;
67b59fbb 2053 static int tried_publickey, tried_agent;
614a20a0 2054 static int tis_auth_refused, ccard_auth_refused;
7cca0d81 2055 static unsigned char session_id[16];
2d466ffd 2056 static int cipher_type;
b585ec46 2057 static char username[100];
396778f1 2058 static void *publickey_blob;
2059 int publickey_bloblen;
374330e2 2060
374330e2 2061 crBegin;
2062
32874aea 2063 if (!ispkt)
2064 crWaitUntil(ispkt);
374330e2 2065
8d5de777 2066 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2067 bombout(("Public key packet not received"));
32874aea 2068 crReturn(0);
8d5de777 2069 }
374330e2 2070
c5e9c988 2071 logevent("Received public keys");
374330e2 2072
c5e9c988 2073 memcpy(cookie, pktin.body, 8);
374330e2 2074
32874aea 2075 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
2076 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
374330e2 2077
c5e9c988 2078 /*
1c2a93c4 2079 * Log the host key fingerprint.
c5e9c988 2080 */
c5e9c988 2081 {
2082 char logmsg[80];
1c2a93c4 2083 logevent("Host key fingerprint is:");
c5e9c988 2084 strcpy(logmsg, " ");
32874aea 2085 hostkey.comment = NULL;
2086 rsa_fingerprint(logmsg + strlen(logmsg),
2087 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2088 logevent(logmsg);
2089 }
2090
32874aea 2091 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2092 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2093 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
bea1ef5f 2094
32874aea 2095 ssh1_local_protoflags =
2096 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
b96dc54c 2097 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2098
c5e9c988 2099 MD5Init(&md5c);
374330e2 2100 MD5Update(&md5c, keystr2, hostkey.bytes);
2101 MD5Update(&md5c, keystr1, servkey.bytes);
2102 MD5Update(&md5c, pktin.body, 8);
374330e2 2103 MD5Final(session_id, &md5c);
2104
32874aea 2105 for (i = 0; i < 32; i++)
374330e2 2106 session_key[i] = random_byte();
2107
2108 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2109
dcbde236 2110 rsabuf = smalloc(len);
374330e2 2111 if (!rsabuf)
2112 fatalbox("Out of memory");
2113
89ee5268 2114 /*
2115 * Verify the host key.
2116 */
2117 {
32874aea 2118 /*
2119 * First format the key into a string.
2120 */
2121 int len = rsastr_len(&hostkey);
2122 char fingerprint[100];
2123 char *keystr = smalloc(len);
2124 if (!keystr)
2125 fatalbox("Out of memory");
2126 rsastr_fmt(keystr, &hostkey);
2127 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2128 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2129 fingerprint);
2130 sfree(keystr);
2131 }
2132
2133 for (i = 0; i < 32; i++) {
374330e2 2134 rsabuf[i] = session_key[i];
2135 if (i < 16)
2136 rsabuf[i] ^= session_id[i];
2137 }
2138
2139 if (hostkey.bytes > servkey.bytes) {
2140 rsaencrypt(rsabuf, 32, &servkey);
2141 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2142 } else {
2143 rsaencrypt(rsabuf, 32, &hostkey);
2144 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2145 }
2146
c5e9c988 2147 logevent("Encrypted session key");
2148
ca20bfcf 2149 {
2150 int cipher_chosen = 0, warn = 0;
2151 char *cipher_string = NULL;
2152 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2153 int next_cipher = cfg.ssh_cipherlist[i];
2154 if (next_cipher == CIPHER_WARN) {
2155 /* If/when we choose a cipher, warn about it */
2156 warn = 1;
2157 } else if (next_cipher == CIPHER_AES) {
2158 /* XXX Probably don't need to mention this. */
2159 logevent("AES not supported in SSH1, skipping");
2160 } else {
2161 switch (next_cipher) {
2162 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2163 cipher_string = "3DES"; break;
2164 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2165 cipher_string = "Blowfish"; break;
2166 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2167 cipher_string = "single-DES"; break;
2168 }
2169 if (supported_ciphers_mask & (1 << cipher_type))
2170 cipher_chosen = 1;
2171 }
2172 }
2173 if (!cipher_chosen) {
2174 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2175 bombout(("Server violates SSH 1 protocol by not "
2176 "supporting 3DES encryption"));
2177 else
2178 /* shouldn't happen */
2179 bombout(("No supported ciphers found"));
a99a05c0 2180 crReturn(0);
2181 }
ca20bfcf 2182
2183 /* Warn about chosen cipher if necessary. */
2184 if (warn)
2185 askcipher(cipher_string, 0);
bea1ef5f 2186 }
ca20bfcf 2187
c5e9c988 2188 switch (cipher_type) {
32874aea 2189 case SSH_CIPHER_3DES:
2190 logevent("Using 3DES encryption");
2191 break;
2192 case SSH_CIPHER_DES:
2193 logevent("Using single-DES encryption");
2194 break;
2195 case SSH_CIPHER_BLOWFISH:
2196 logevent("Using Blowfish encryption");
2197 break;
c5e9c988 2198 }
bea1ef5f 2199
e5574168 2200 send_packet(SSH1_CMSG_SESSION_KEY,
32874aea 2201 PKT_CHAR, cipher_type,
2202 PKT_DATA, cookie, 8,
2203 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2204 PKT_DATA, rsabuf, len,
2205 PKT_INT, ssh1_local_protoflags, PKT_END);
fb09bf1c 2206
c5e9c988 2207 logevent("Trying to enable encryption...");
374330e2 2208
dcbde236 2209 sfree(rsabuf);
374330e2 2210
5e8358ad 2211 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
32874aea 2212 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
374330e2 2213 cipher->sesskey(session_key);
2214
fb09bf1c 2215 crWaitUntil(ispkt);
374330e2 2216
8d5de777 2217 if (pktin.type != SSH1_SMSG_SUCCESS) {
2218 bombout(("Encryption not successfully enabled"));
32874aea 2219 crReturn(0);
8d5de777 2220 }
374330e2 2221
c5e9c988 2222 logevent("Successfully started encryption");
2223
374330e2 2224 fflush(stdout);
2225 {
374330e2 2226 static int pos = 0;
2227 static char c;
67779be7 2228 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 2229 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2230 if (!ssh_get_line("login as: ",
2231 username, sizeof(username), FALSE)) {
2232 /*
2233 * get_line failed to get a username.
2234 * Terminate.
2235 */
2236 logevent("No username provided. Abandoning session.");
2237 ssh_state = SSH_STATE_CLOSED;
2238 crReturn(1);
2239 }
2240 } else {
2241 c_write_str("login as: ");
2242 ssh_send_ok = 1;
2243 while (pos >= 0) {
2244 crWaitUntil(!ispkt);
2245 while (inlen--)
2246 switch (c = *in++) {
2247 case 10:
2248 case 13:
2249 username[pos] = 0;
2250 pos = -1;
2251 break;
2252 case 8:
2253 case 127:
2254 if (pos > 0) {
2255 c_write_str("\b \b");
2256 pos--;
2257 }
2258 break;
2259 case 21:
2260 case 27:
2261 while (pos > 0) {
2262 c_write_str("\b \b");
2263 pos--;
2264 }
2265 break;
2266 case 3:
2267 case 4:
93b581bd 2268 cleanup_exit(0);
32874aea 2269 break;
2270 default:
2271 if (((c >= ' ' && c <= '~') ||
51b2fb65 2272 ((unsigned char) c >= 160))
2273 && pos < sizeof(username)-1) {
32874aea 2274 username[pos++] = c;
2275 c_write(&c, 1);
2276 }
2277 break;
2278 }
2279 }
2280 c_write_str("\r\n");
2281 username[strcspn(username, "\n\r")] = '\0';
2282 }
2283 } else {
374330e2 2284 strncpy(username, cfg.username, 99);
2285 username[99] = '\0';
374330e2 2286 }
fb09bf1c 2287
e5574168 2288 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 2289 {
32874aea 2290 char userlog[22 + sizeof(username)];
c5e9c988 2291 sprintf(userlog, "Sent username \"%s\"", username);
2292 logevent(userlog);
32874aea 2293 if (flags & FLAG_INTERACTIVE &&
2294 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2295 strcat(userlog, "\r\n");
32874aea 2296 c_write_str(userlog);
3c8e959b 2297 }
c5e9c988 2298 }
374330e2 2299 }
2300
fb09bf1c 2301 crWaitUntil(ispkt);
374330e2 2302
0df73905 2303 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2304 /* We must not attempt PK auth. Pretend we've already tried it. */
2305 tried_publickey = tried_agent = 1;
2306 } else {
2307 tried_publickey = tried_agent = 0;
2308 }
614a20a0 2309 tis_auth_refused = ccard_auth_refused = 0;
396778f1 2310 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2311 if (*cfg.keyfile) {
2312 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2313 publickey_blob = NULL;
2314 } else
2315 publickey_blob = NULL;
7cca0d81 2316
e5574168 2317 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 2318 static char password[100];
a52f067e 2319 static char prompt[200];
374330e2 2320 static int pos;
2321 static char c;
32874aea 2322 static int pwpkt_type;
32874aea 2323 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2324
67b59fbb 2325 if (agent_exists() && !tried_agent) {
32874aea 2326 /*
2327 * Attempt RSA authentication using Pageant.
2328 */
2329 static unsigned char request[5], *response, *p;
2330 static int responselen;
2331 static int i, nkeys;
2332 static int authed = FALSE;
2333 void *r;
2334
67b59fbb 2335 tried_agent = 1;
32874aea 2336 logevent("Pageant is running. Requesting keys.");
2337
2338 /* Request the keys held by the agent. */
2339 PUT_32BIT(request, 1);
2340 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2341 agent_query(request, 5, &r, &responselen);
2342 response = (unsigned char *) r;
2343 if (response && responselen >= 5 &&
2344 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2345 p = response + 5;
2346 nkeys = GET_32BIT(p);
2347 p += 4;
2348 {
2349 char buf[64];
2350 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2351 logevent(buf);
2352 }
2353 for (i = 0; i < nkeys; i++) {
2354 static struct RSAKey key;
2355 static Bignum challenge;
2356 static char *commentp;
2357 static int commentlen;
2358
2359 {
2360 char buf[64];
2361 sprintf(buf, "Trying Pageant key #%d", i);
2362 logevent(buf);
2363 }
396778f1 2364 if (publickey_blob &&
2365 !memcmp(p, publickey_blob, publickey_bloblen)) {
2366 logevent("This key matches configured key file");
2367 tried_publickey = 1;
2368 }
32874aea 2369 p += 4;
2370 p += ssh1_read_bignum(p, &key.exponent);
2371 p += ssh1_read_bignum(p, &key.modulus);
2372 commentlen = GET_32BIT(p);
2373 p += 4;
2374 commentp = p;
2375 p += commentlen;
2376 send_packet(SSH1_CMSG_AUTH_RSA,
2377 PKT_BIGNUM, key.modulus, PKT_END);
2378 crWaitUntil(ispkt);
2379 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2380 logevent("Key refused");
2381 continue;
2382 }
2383 logevent("Received RSA challenge");
2384 ssh1_read_bignum(pktin.body, &challenge);
2385 {
2386 char *agentreq, *q, *ret;
2d466ffd 2387 void *vret;
32874aea 2388 int len, retlen;
2389 len = 1 + 4; /* message type, bit count */
2390 len += ssh1_bignum_length(key.exponent);
2391 len += ssh1_bignum_length(key.modulus);
2392 len += ssh1_bignum_length(challenge);
2393 len += 16; /* session id */
2394 len += 4; /* response format */
2395 agentreq = smalloc(4 + len);
2396 PUT_32BIT(agentreq, len);
2397 q = agentreq + 4;
2398 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2399 PUT_32BIT(q, bignum_bitcount(key.modulus));
2400 q += 4;
2401 q += ssh1_write_bignum(q, key.exponent);
2402 q += ssh1_write_bignum(q, key.modulus);
2403 q += ssh1_write_bignum(q, challenge);
2404 memcpy(q, session_id, 16);
2405 q += 16;
2406 PUT_32BIT(q, 1); /* response format */
2d466ffd 2407 agent_query(agentreq, len + 4, &vret, &retlen);
2408 ret = vret;
32874aea 2409 sfree(agentreq);
2410 if (ret) {
2411 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2412 logevent("Sending Pageant's response");
2413 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2414 PKT_DATA, ret + 5, 16,
2415 PKT_END);
2416 sfree(ret);
2417 crWaitUntil(ispkt);
2418 if (pktin.type == SSH1_SMSG_SUCCESS) {
2419 logevent
2420 ("Pageant's response accepted");
2421 if (flags & FLAG_VERBOSE) {
2422 c_write_str
2423 ("Authenticated using RSA key \"");
2424 c_write(commentp, commentlen);
2425 c_write_str("\" from agent\r\n");
2426 }
2427 authed = TRUE;
2428 } else
2429 logevent
2430 ("Pageant's response not accepted");
2431 } else {
2432 logevent
2433 ("Pageant failed to answer challenge");
2434 sfree(ret);
2435 }
2436 } else {
2437 logevent("No reply received from Pageant");
2438 }
2439 }
2440 freebn(key.exponent);
2441 freebn(key.modulus);
2442 freebn(challenge);
2443 if (authed)
2444 break;
2445 }
2446 }
2447 if (authed)
2448 break;
2449 }
2450 if (*cfg.keyfile && !tried_publickey)
2451 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2452
614a20a0 2453 if (cfg.try_tis_auth &&
2454 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2455 !tis_auth_refused) {
32874aea 2456 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2457 logevent("Requested TIS authentication");
2458 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2459 crWaitUntil(ispkt);
2460 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2461 logevent("TIS authentication declined");
2462 if (flags & FLAG_INTERACTIVE)
2463 c_write_str("TIS authentication refused.\r\n");
614a20a0 2464 tis_auth_refused = 1;
2465 continue;
32874aea 2466 } else {
2467 int challengelen = ((pktin.body[0] << 24) |
2468 (pktin.body[1] << 16) |
2469 (pktin.body[2] << 8) |
2470 (pktin.body[3]));
2471 logevent("Received TIS challenge");
2472 if (challengelen > sizeof(prompt) - 1)
2473 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2474 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2475 /* Prompt heuristic comes from OpenSSH */
2476 strncpy(prompt + challengelen,
2477 memchr(prompt, '\n', challengelen) ?
2478 "": "\r\nResponse: ",
2479 (sizeof prompt) - challengelen);
2480 prompt[(sizeof prompt) - 1] = '\0';
32874aea 2481 }
2482 }
614a20a0 2483 if (cfg.try_tis_auth &&
2484 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2485 !ccard_auth_refused) {
32874aea 2486 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2487 logevent("Requested CryptoCard authentication");
2488 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2489 crWaitUntil(ispkt);
2490 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2491 logevent("CryptoCard authentication declined");
2492 c_write_str("CryptoCard authentication refused.\r\n");
614a20a0 2493 ccard_auth_refused = 1;
2494 continue;
32874aea 2495 } else {
2496 int challengelen = ((pktin.body[0] << 24) |
2497 (pktin.body[1] << 16) |
2498 (pktin.body[2] << 8) |
2499 (pktin.body[3]));
2500 logevent("Received CryptoCard challenge");
2501 if (challengelen > sizeof(prompt) - 1)
2502 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2503 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2504 strncpy(prompt + challengelen,
2505 memchr(prompt, '\n', challengelen) ?
2506 "" : "\r\nResponse: ",
32874aea 2507 sizeof(prompt) - challengelen);
2508 prompt[sizeof(prompt) - 1] = '\0';
2509 }
2510 }
2511 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2512 sprintf(prompt, "%.90s@%.90s's password: ",
2513 username, savedhost);
2514 }
2515 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2516 char *comment = NULL;
231ee168 2517 int type;
2518 char msgbuf[256];
32874aea 2519 if (flags & FLAG_VERBOSE)
2520 c_write_str("Trying public key authentication.\r\n");
231ee168 2521 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2522 logevent(msgbuf);
2523 type = key_type(cfg.keyfile);
2524 if (type != SSH_KEYTYPE_SSH1) {
2525 sprintf(msgbuf, "Key is of wrong type (%s)",
2526 key_type_to_str(type));
2527 logevent(msgbuf);
2528 c_write_str(msgbuf);
2529 c_write_str("\r\n");
2530 tried_publickey = 1;
2531 continue;
2532 }
32874aea 2533 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2534 if (flags & FLAG_VERBOSE)
2535 c_write_str("No passphrase required.\r\n");
2536 goto tryauth;
2537 }
2538 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2539 sfree(comment);
2540 }
a52f067e 2541
614a20a0 2542 /*
2543 * Show password prompt, having first obtained it via a TIS
2544 * or CryptoCard exchange if we're doing TIS or CryptoCard
2545 * authentication.
2546 */
fa17a66e 2547 if (ssh_get_line) {
2548 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
32874aea 2549 /*
2550 * get_line failed to get a password (for example
2551 * because one was supplied on the command line
2552 * which has already failed to work). Terminate.
2553 */
2bc6a386 2554 send_packet(SSH1_MSG_DISCONNECT,
2555 PKT_STR, "No more passwords available to try",
2556 PKT_END);
247308b5 2557 logevent("Unable to authenticate");
2bc6a386 2558 connection_fatal("Unable to authenticate");
32874aea 2559 ssh_state = SSH_STATE_CLOSED;
2560 crReturn(1);
2561 }
fb09bf1c 2562 } else {
614a20a0 2563 /* Prompt may have come from server. We've munged it a bit, so
2564 * we know it to be zero-terminated at least once. */
2565 c_write_untrusted(prompt, strlen(prompt));
32874aea 2566 pos = 0;
2567 ssh_send_ok = 1;
2568 while (pos >= 0) {
2569 crWaitUntil(!ispkt);
2570 while (inlen--)
2571 switch (c = *in++) {
2572 case 10:
2573 case 13:
2574 password[pos] = 0;
2575 pos = -1;
2576 break;
2577 case 8:
2578 case 127:
2579 if (pos > 0)
2580 pos--;
2581 break;
2582 case 21:
2583 case 27:
2584 pos = 0;
2585 break;
2586 case 3:
2587 case 4:
93b581bd 2588 cleanup_exit(0);
32874aea 2589 break;
2590 default:
51b2fb65 2591 if (pos < sizeof(password)-1)
32874aea 2592 password[pos++] = c;
2593 break;
2594 }
2595 }
2596 c_write_str("\r\n");
2597 }
2598
2599 tryauth:
7cca0d81 2600 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2601 /*
2602 * Try public key authentication with the specified
2603 * key file.
2604 */
2605 static struct RSAKey pubkey;
2606 static Bignum challenge, response;
2607 static int i;
2608 static unsigned char buffer[32];
2609
2610 tried_publickey = 1;
2611 i = loadrsakey(cfg.keyfile, &pubkey, password);
2612 if (i == 0) {
7963af2f 2613 c_write_str("Couldn't load private key from ");
32874aea 2614 c_write_str(cfg.keyfile);
2615 c_write_str(".\r\n");
2616 continue; /* go and try password */
2617 }
2618 if (i == -1) {
2619 c_write_str("Wrong passphrase.\r\n");
2620 tried_publickey = 0;
2621 continue; /* try again */
2622 }
2623
2624 /*
2625 * Send a public key attempt.
2626 */
2627 send_packet(SSH1_CMSG_AUTH_RSA,
2628 PKT_BIGNUM, pubkey.modulus, PKT_END);
2629
2630 crWaitUntil(ispkt);
2631 if (pktin.type == SSH1_SMSG_FAILURE) {
2632 c_write_str("Server refused our public key.\r\n");
2633 continue; /* go and try password */
2634 }
2635 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2636 bombout(("Bizarre response to offer of public key"));
2637 crReturn(0);
2638 }
2639 ssh1_read_bignum(pktin.body, &challenge);
2640 response = rsadecrypt(challenge, &pubkey);
2641 freebn(pubkey.private_exponent); /* burn the evidence */
2642
2643 for (i = 0; i < 32; i++) {
2644 buffer[i] = bignum_byte(response, 31 - i);
2645 }
2646
2647 MD5Init(&md5c);
2648 MD5Update(&md5c, buffer, 32);
2649 MD5Update(&md5c, session_id, 16);
2650 MD5Final(buffer, &md5c);
2651
2652 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2653 PKT_DATA, buffer, 16, PKT_END);
2654
2655 crWaitUntil(ispkt);
2656 if (pktin.type == SSH1_SMSG_FAILURE) {
2657 if (flags & FLAG_VERBOSE)
2658 c_write_str
2659 ("Failed to authenticate with our public key.\r\n");
2660 continue; /* go and try password */
2661 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2662 bombout(
2663 ("Bizarre response to RSA authentication response"));
2664 crReturn(0);
2665 }
2666
2667 break; /* we're through! */
2668 } else {
2669 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2670 /*
2671 * Defence against traffic analysis: we send a
2672 * whole bunch of packets containing strings of
2673 * different lengths. One of these strings is the
2674 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2675 * The others are all random data in
2676 * SSH1_MSG_IGNORE packets. This way a passive
2677 * listener can't tell which is the password, and
2678 * hence can't deduce the password length.
2679 *
2680 * Anybody with a password length greater than 16
2681 * bytes is going to have enough entropy in their
2682 * password that a listener won't find it _that_
2683 * much help to know how long it is. So what we'll
2684 * do is:
2685 *
2686 * - if password length < 16, we send 15 packets
2687 * containing string lengths 1 through 15
2688 *
2689 * - otherwise, we let N be the nearest multiple
2690 * of 8 below the password length, and send 8
2691 * packets containing string lengths N through
2692 * N+7. This won't obscure the order of
2693 * magnitude of the password length, but it will
2694 * introduce a bit of extra uncertainty.
2695 *
2696 * A few servers (the old 1.2.18 through 1.2.22)
2697 * can't deal with SSH1_MSG_IGNORE. For these
2698 * servers, we need an alternative defence. We make
2699 * use of the fact that the password is interpreted
2700 * as a C string: so we can append a NUL, then some
2701 * random data.
bd358db1 2702 *
2703 * One server (a Cisco one) can deal with neither
2704 * SSH1_MSG_IGNORE _nor_ a padded password string.
2705 * For this server we are left with no defences
2706 * against password length sniffing.
32874aea 2707 */
bd358db1 2708 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2709 /*
2710 * The server can deal with SSH1_MSG_IGNORE, so
2711 * we can use the primary defence.
2712 */
32874aea 2713 int bottom, top, pwlen, i;
2714 char *randomstr;
2715
2716 pwlen = strlen(password);
2717 if (pwlen < 16) {
2718 bottom = 0; /* zero length passwords are OK! :-) */
2719 top = 15;
2720 } else {
2721 bottom = pwlen & ~7;
2722 top = bottom + 7;
2723 }
2724
2725 assert(pwlen >= bottom && pwlen <= top);
2726
2727 randomstr = smalloc(top + 1);
2728
2729 for (i = bottom; i <= top; i++) {
2730 if (i == pwlen)
2731 defer_packet(pwpkt_type, PKT_STR, password,
2732 PKT_END);
2733 else {
2734 for (j = 0; j < i; j++) {
2735 do {
2736 randomstr[j] = random_byte();
2737 } while (randomstr[j] == '\0');
2738 }
2739 randomstr[i] = '\0';
2740 defer_packet(SSH1_MSG_IGNORE,
2741 PKT_STR, randomstr, PKT_END);
2742 }
2743 }
bd358db1 2744 logevent("Sending password with camouflage packets");
32874aea 2745 ssh_pkt_defersend();
bd358db1 2746 }
2747 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2748 /*
2749 * The server can't deal with SSH1_MSG_IGNORE
2750 * but can deal with padded passwords, so we
2751 * can use the secondary defence.
2752 */
bd358db1 2753 char string[64];
2754 char *s;
2755 int len;
2756
2757 len = strlen(password);
2758 if (len < sizeof(string)) {
2759 s = string;
2760 strcpy(string, password);
2761 len++; /* cover the zero byte */
2762 while (len < sizeof(string)) {
2763 string[len++] = (char) random_byte();
2764 }
2765 } else {
2766 s = password;
2767 }
2768 logevent("Sending length-padded password");
2769 send_packet(pwpkt_type, PKT_INT, len,
2770 PKT_DATA, s, len, PKT_END);
2771 } else {
2772 /*
2773 * The server has _both_
2774 * BUG_CHOKES_ON_SSH1_IGNORE and
2775 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2776 * therefore nothing we can do.
2777 */
2778 int len;
2779 len = strlen(password);
2780 logevent("Sending unpadded password");
2781 send_packet(pwpkt_type, PKT_INT, len,
2782 PKT_DATA, password, len, PKT_END);
32874aea 2783 }
2784 } else {
2785 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2786 }
2787 }
c5e9c988 2788 logevent("Sent password");
374330e2 2789 memset(password, 0, strlen(password));
fb09bf1c 2790 crWaitUntil(ispkt);
e5574168 2791 if (pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2792 if (flags & FLAG_VERBOSE)
2793 c_write_str("Access denied\r\n");
c5e9c988 2794 logevent("Authentication refused");
e5574168 2795 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2796 logevent("Received disconnect request");
32874aea 2797 ssh_state = SSH_STATE_CLOSED;
85ee8208 2798 crReturn(1);
e5574168 2799 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2800 bombout(("Strange packet received, type %d", pktin.type));
32874aea 2801 crReturn(0);
374330e2 2802 }
2803 }
2804
c5e9c988 2805 logevent("Authentication successful");
2806
fb09bf1c 2807 crFinish(1);
2808}
2809
32874aea 2810void sshfwd_close(struct ssh_channel *c)
2811{
80e48603 2812 if (c && !c->closes) {
4ed34d25 2813 /*
2814 * If the channel's remoteid is -1, we have sent
2815 * CHANNEL_OPEN for this channel, but it hasn't even been
2816 * acknowledged by the server. So we must set a close flag
2817 * on it now, and then when the server acks the channel
2818 * open, we can close it then.
2819 */
36cac739 2820 if (((int)c->remoteid) != -1) {
4ed34d25 2821 if (ssh_version == 1) {
2822 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2823 PKT_END);
2824 } else {
2825 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2826 ssh2_pkt_adduint32(c->remoteid);
2827 ssh2_pkt_send();
2828 }
32874aea 2829 }
2830 c->closes = 1;
2831 if (c->type == CHAN_X11) {
2832 c->u.x11.s = NULL;
d74d141c 2833 logevent("Forwarded X11 connection terminated");
4ed34d25 2834 } else if (c->type == CHAN_SOCKDATA ||
2835 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2836 c->u.pfd.s = NULL;
2837 logevent("Forwarded port closed");
32874aea 2838 }
2839 }
2840}
2841
5471d09a 2842int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2843{
783415f8 2844 if (ssh_version == 1) {
32874aea 2845 send_packet(SSH1_MSG_CHANNEL_DATA,
2846 PKT_INT, c->remoteid,
2847 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2848 /*
2849 * In SSH1 we can return 0 here - implying that forwarded
2850 * connections are never individually throttled - because
2851 * the only circumstance that can cause throttling will be
2852 * the whole SSH connection backing up, in which case
2853 * _everything_ will be throttled as a whole.
2854 */
2855 return 0;
783415f8 2856 } else {
32874aea 2857 ssh2_add_channel_data(c, buf, len);
5471d09a 2858 return ssh2_try_send(c);
2859 }
2860}
2861
2862void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2863{
2864 if (ssh_version == 1) {
2865 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2866 c->v.v1.throttling = 0;
2867 ssh1_throttle(-1);
2868 }
2869 } else {
2870 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2871 }
9c964e85 2872}
2873
32874aea 2874static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2875{
fb09bf1c 2876 crBegin;
2877
2878 random_init();
2879
e5574168 2880 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2881 crReturnV;
85ee8208 2882 }
2883 if (ssh_state == SSH_STATE_CLOSED)
32874aea 2884 crReturnV;
fb09bf1c 2885
979310f1 2886 if (cfg.agentfwd && agent_exists()) {
32874aea 2887 logevent("Requesting agent forwarding");
2888 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2889 do {
2890 crReturnV;
2891 } while (!ispkt);
2892 if (pktin.type != SSH1_SMSG_SUCCESS
2893 && pktin.type != SSH1_SMSG_FAILURE) {
2894 bombout(("Protocol confusion"));
2895 crReturnV;
2896 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2897 logevent("Agent forwarding refused");
2898 } else {
2899 logevent("Agent forwarding enabled");
db7d555c 2900 ssh_agentfwd_enabled = TRUE;
2901 }
dacbd0e8 2902 }
2903
9c964e85 2904 if (cfg.x11_forward) {
32874aea 2905 char proto[20], data[64];
2906 logevent("Requesting X11 forwarding");
2907 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2908 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2909 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2910 PKT_STR, proto, PKT_STR, data,
2911 PKT_INT, 0, PKT_END);
2912 } else {
2913 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2914 PKT_STR, proto, PKT_STR, data, PKT_END);
2915 }
2916 do {
2917 crReturnV;
2918 } while (!ispkt);
2919 if (pktin.type != SSH1_SMSG_SUCCESS
2920 && pktin.type != SSH1_SMSG_FAILURE) {
2921 bombout(("Protocol confusion"));
2922 crReturnV;
2923 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2924 logevent("X11 forwarding refused");
2925 } else {
2926 logevent("X11 forwarding enabled");
9c964e85 2927 ssh_X11_fwd_enabled = TRUE;
2928 }
2929 }
2930
d74d141c 2931 {
9bf696b1 2932 char type;
2933 static char *e;
d74d141c 2934 int n;
a4fc0d74 2935 int sport,dport,sserv,dserv;
d74d141c 2936 char sports[256], dports[256], host[256];
2937 char buf[1024];
a4fc0d74 2938 struct servent *se;
d74d141c 2939
bc240b21 2940 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 2941 /* Add port forwardings. */
2942 e = cfg.portfwd;
2943 while (*e) {
2944 type = *e++;
2945 n = 0;
2946 while (*e && *e != '\t')
2947 sports[n++] = *e++;
2948 sports[n] = 0;
2949 if (*e == '\t')
2950 e++;
2951 n = 0;
2952 while (*e && *e != ':')
2953 host[n++] = *e++;
2954 host[n] = 0;
2955 if (*e == ':')
2956 e++;
2957 n = 0;
2958 while (*e)
2959 dports[n++] = *e++;
2960 dports[n] = 0;
2961 e++;
2962 dport = atoi(dports);
a4fc0d74 2963 dserv = 0;
2964 if (dport == 0) {
2965 dserv = 1;
2966 se = getservbyname(dports, NULL);
2967 if (se != NULL) {
2968 dport = ntohs(se->s_port);
2969 } else {
2970 sprintf(buf,
2971 "Service lookup failed for destination port \"%s\"",
2972 dports);
2973 logevent(buf);
2974 }
2975 }
d74d141c 2976 sport = atoi(sports);
a4fc0d74 2977 sserv = 0;
2978 if (sport == 0) {
2979 sserv = 1;
2980 se = getservbyname(sports, NULL);
2981 if (se != NULL) {
2982 sport = ntohs(se->s_port);
2983 } else {
2984 sprintf(buf,
2985 "Service lookup failed for source port \"%s\"",
2986 sports);
2987 logevent(buf);
2988 }
2989 }
d74d141c 2990 if (sport && dport) {
2991 if (type == 'L') {
2992 pfd_addforward(host, dport, sport);
a4fc0d74 2993 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
2994 " %s:%.*s%.*s%d%.*s",
2995 sserv ? strlen(sports) : 0, sports,
2996 sserv, "(", sport, sserv, ")",
2997 host,
2998 dserv ? strlen(dports) : 0, dports,
2999 dserv, "(", dport, dserv, ")");
d74d141c 3000 logevent(buf);
3001 } else {
3002 struct ssh_rportfwd *pf;
3003 pf = smalloc(sizeof(*pf));
bc240b21 3004 strcpy(pf->dhost, host);
3005 pf->dport = dport;
d74d141c 3006 if (add234(ssh_rportfwds, pf) != pf) {
3007 sprintf(buf,
95bc8819 3008 "Duplicate remote port forwarding to %s:%d",
d74d141c 3009 host, dport);
3010 logevent(buf);
bc240b21 3011 sfree(pf);
d74d141c 3012 } else {
a4fc0d74 3013 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3014 " forward to %s:%.*s%.*s%d%.*s",
3015 sserv ? strlen(sports) : 0, sports,
3016 sserv, "(", sport, sserv, ")",
3017 host,
3018 dserv ? strlen(dports) : 0, dports,
3019 dserv, "(", dport, dserv, ")");
d74d141c 3020 logevent(buf);
3021 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
3022 PKT_INT, sport,
3023 PKT_STR, host,
3024 PKT_INT, dport,
3025 PKT_END);
9bf696b1 3026 do {
3027 crReturnV;
3028 } while (!ispkt);
3029 if (pktin.type != SSH1_SMSG_SUCCESS
3030 && pktin.type != SSH1_SMSG_FAILURE) {
3031 bombout(("Protocol confusion"));
3032 crReturnV;
3033 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3034 c_write_str("Server refused port forwarding\r\n");
3035 ssh_editing = ssh_echoing = 1;
3036 }
3037 logevent("Remote port forwarding enabled");
d74d141c 3038 }
3039 }
3040 }
3041 }
3042 }
3043
fef97f43 3044 if (!cfg.nopty) {
e5574168 3045 send_packet(SSH1_CMSG_REQUEST_PTY,
32874aea 3046 PKT_STR, cfg.termtype,
3047 PKT_INT, rows, PKT_INT, cols,
3048 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3049 ssh_state = SSH_STATE_INTERMED;
3050 do {
3051 crReturnV;
3052 } while (!ispkt);
3053 if (pktin.type != SSH1_SMSG_SUCCESS
3054 && pktin.type != SSH1_SMSG_FAILURE) {
3055 bombout(("Protocol confusion"));
3056 crReturnV;
3057 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3058 c_write_str("Server refused to allocate pty\r\n");
3059 ssh_editing = ssh_echoing = 1;
3060 }
c5e9c988 3061 logevent("Allocated pty");
0965bee0 3062 } else {
32874aea 3063 ssh_editing = ssh_echoing = 1;
374330e2 3064 }
3065
4ba9b64b 3066 if (cfg.compression) {
32874aea 3067 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3068 do {
3069 crReturnV;
3070 } while (!ispkt);
3071 if (pktin.type != SSH1_SMSG_SUCCESS
3072 && pktin.type != SSH1_SMSG_FAILURE) {
3073 bombout(("Protocol confusion"));
3074 crReturnV;
3075 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3076 c_write_str("Server refused to compress\r\n");
3077 }
4ba9b64b 3078 logevent("Started compression");
3079 ssh1_compressing = TRUE;
3080 zlib_compress_init();
3081 zlib_decompress_init();
3082 }
3083
fd5e5847 3084 /*
3085 * Start the shell or command.
3086 *
3087 * Special case: if the first-choice command is an SSH2
3088 * subsystem (hence not usable here) and the second choice
3089 * exists, we fall straight back to that.
3090 */
3091 {
3092 char *cmd = cfg.remote_cmd_ptr;
3093
3094 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3095 cmd = cfg.remote_cmd_ptr2;
3096 ssh_fallback_cmd = TRUE;
3097 }
3098 if (*cmd)
3099 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3100 else
3101 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3102 logevent("Started session");
3103 }
374330e2 3104
3105 ssh_state = SSH_STATE_SESSION;
3106 if (size_needed)
3107 ssh_size();
3687d221 3108 if (eof_needed)
32874aea 3109 ssh_special(TS_EOF);
374330e2 3110
760e88b2 3111 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 3112 ssh_send_ok = 1;
dacbd0e8 3113 ssh_channels = newtree234(ssh_channelcmp);
374330e2 3114 while (1) {
3115 crReturnV;
3116 if (ispkt) {
e5574168 3117 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 3118 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 3119 long len = GET_32BIT(pktin.body);
5471d09a 3120 int bufsize =
3121 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
3122 pktin.body + 4, len);
90347b95 3123 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3124 ssh1_stdout_throttling = 1;
3125 ssh1_throttle(+1);
3126 }
e5574168 3127 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
32874aea 3128 ssh_state = SSH_STATE_CLOSED;
c5e9c988 3129 logevent("Received disconnect request");
32874aea 3130 crReturnV;
3131 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3132 /* Remote side is trying to open a channel to talk to our
3133 * X-Server. Give them back a local channel number. */
3134 struct ssh_channel *c;
9c964e85 3135
3136 logevent("Received X11 connect request");
3137 /* Refuse if X11 forwarding is disabled. */
3138 if (!ssh_X11_fwd_enabled) {
3139 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 3140 PKT_INT, GET_32BIT(pktin.body), PKT_END);
9c964e85 3141 logevent("Rejected X11 connect request");
3142 } else {
9c964e85 3143 c = smalloc(sizeof(struct ssh_channel));
3144
32874aea 3145 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3146 logevent("opening X11 forward connection failed");
3147 sfree(c);
3148 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3149 PKT_INT, GET_32BIT(pktin.body),
3150 PKT_END);
9c964e85 3151 } else {
32874aea 3152 logevent
3153 ("opening X11 forward connection succeeded");
3154 c->remoteid = GET_32BIT(pktin.body);
3155 c->localid = alloc_channel_id();
3156 c->closes = 0;
5471d09a 3157 c->v.v1.throttling = 0;
32874aea 3158 c->type = CHAN_X11; /* identify channel type */
3159 add234(ssh_channels, c);
3160 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3161 PKT_INT, c->remoteid, PKT_INT,
3162 c->localid, PKT_END);
3163 logevent("Opened X11 forward channel");
9c964e85 3164 }
3165 }
32874aea 3166 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3167 /* Remote side is trying to open a channel to talk to our
3168 * agent. Give them back a local channel number. */
3169 struct ssh_channel *c;
db7d555c 3170
3171 /* Refuse if agent forwarding is disabled. */
3172 if (!ssh_agentfwd_enabled) {
3173 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 3174 PKT_INT, GET_32BIT(pktin.body), PKT_END);
db7d555c 3175 } else {
dcbde236 3176 c = smalloc(sizeof(struct ssh_channel));
db7d555c 3177 c->remoteid = GET_32BIT(pktin.body);
d2371c81 3178 c->localid = alloc_channel_id();
db7d555c 3179 c->closes = 0;
5471d09a 3180 c->v.v1.throttling = 0;
32874aea 3181 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3182 c->u.a.lensofar = 0;
3183 add234(ssh_channels, c);
3184 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3185 PKT_INT, c->remoteid, PKT_INT, c->localid,
3186 PKT_END);
3187 }
d74d141c 3188 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3189 /* Remote side is trying to open a channel to talk to a
3190 * forwarded port. Give them back a local channel number. */
3191 struct ssh_channel *c;
3192 struct ssh_rportfwd pf;
3193 int hostsize, port;
3194 char host[256], buf[1024];
3195 char *p, *h, *e;
3196 c = smalloc(sizeof(struct ssh_channel));
3197
3198 hostsize = GET_32BIT(pktin.body+4);
3199 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3200 if (h+1 < host+sizeof(host))
3201 *h++ = *p;
95bc8819 3202 p++;
d74d141c 3203 }
3204 *h = 0;
3205 port = GET_32BIT(p);
3206
bc240b21 3207 strcpy(pf.dhost, host);
3208 pf.dport = port;
d74d141c 3209
3210 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3211 sprintf(buf, "Rejected remote port open request for %s:%d",
3212 host, port);
3213 logevent(buf);
3214 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3215 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3216 } else {
3217 sprintf(buf, "Received remote port open request for %s:%d",
3218 host, port);
3219 logevent(buf);
3220 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3221 if (e != NULL) {
3222 char buf[256];
3223 sprintf(buf, "Port open failed: %s", e);
3224 logevent(buf);
3225 sfree(c);
3226 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3227 PKT_INT, GET_32BIT(pktin.body),
3228 PKT_END);
3229 } else {
3230 c->remoteid = GET_32BIT(pktin.body);
3231 c->localid = alloc_channel_id();
3232 c->closes = 0;
5471d09a 3233 c->v.v1.throttling = 0;
d74d141c 3234 c->type = CHAN_SOCKDATA; /* identify channel type */
3235 add234(ssh_channels, c);
3236 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3237 PKT_INT, c->remoteid, PKT_INT,
3238 c->localid, PKT_END);
3239 logevent("Forwarded port opened successfully");
3240 }
3241 }
3242
3243 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
bc240b21 3244 unsigned int remoteid = GET_32BIT(pktin.body);
3245 unsigned int localid = GET_32BIT(pktin.body+4);
3246 struct ssh_channel *c;
3247
3248 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3249 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3250 c->remoteid = localid;
3251 c->type = CHAN_SOCKDATA;
7781f316 3252 c->v.v1.throttling = 0;
bc240b21 3253 pfd_confirm(c->u.pfd.s);
3254 }
d74d141c 3255
4ed34d25 3256 if (c && c->closes) {
3257 /*
3258 * We have a pending close on this channel,
3259 * which we decided on before the server acked
3260 * the channel open. So now we know the
3261 * remoteid, we can close it again.
3262 */
3263 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3264 PKT_END);
3265 }
3266
724cface 3267 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3268 unsigned int remoteid = GET_32BIT(pktin.body);
3269 unsigned int localid = GET_32BIT(pktin.body+4);
3270 struct ssh_channel *c;
3271
3272 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3273 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3274 logevent("Forwarded connection refused by server");
3275 pfd_close(c->u.pfd.s);
3276 del234(ssh_channels, c);
3277 sfree(c);
3278 }
3279
db7d555c 3280 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3281 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3282 /* Remote side closes a channel. */
3283 unsigned i = GET_32BIT(pktin.body);
3284 struct ssh_channel *c;
3285 c = find234(ssh_channels, &i, ssh_channelfind);
3286 if (c) {
3287 int closetype;
3288 closetype =
3289 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3290 if (!(c->closes & closetype))
3291 send_packet(pktin.type, PKT_INT, c->remoteid,
3292 PKT_END);
783415f8 3293 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3294 logevent("Forwarded X11 connection terminated");
9c964e85 3295 assert(c->u.x11.s != NULL);
3296 x11_close(c->u.x11.s);
3297 c->u.x11.s = NULL;
3298 }
d74d141c 3299 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3300 logevent("Forwarded port closed");
3301 assert(c->u.pfd.s != NULL);
3302 pfd_close(c->u.pfd.s);
3303 c->u.pfd.s = NULL;
3304 }
32874aea 3305 c->closes |= closetype;
3306 if (c->closes == 3) {
3307 del234(ssh_channels, c);
3308 sfree(c);
3309 }
3310 }
3311 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3312 /* Data sent down one of our channels. */
3313 int i = GET_32BIT(pktin.body);
3314 int len = GET_32BIT(pktin.body + 4);
3315 unsigned char *p = pktin.body + 8;
3316 struct ssh_channel *c;
3317 c = find234(ssh_channels, &i, ssh_channelfind);
3318 if (c) {
5471d09a 3319 int bufsize;
32874aea 3320 switch (c->type) {
3321 case CHAN_X11:
5471d09a 3322 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 3323 break;
d74d141c 3324 case CHAN_SOCKDATA:
5471d09a 3325 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 3326 break;
32874aea 3327 case CHAN_AGENT:
3328 /* Data for an agent message. Buffer it. */
3329 while (len > 0) {
3330 if (c->u.a.lensofar < 4) {
3331 int l = min(4 - c->u.a.lensofar, len);
3332 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3333 l);
3334 p += l;
3335 len -= l;
3336 c->u.a.lensofar += l;
3337 }
3338 if (c->u.a.lensofar == 4) {
3339 c->u.a.totallen =
3340 4 + GET_32BIT(c->u.a.msglen);
3341 c->u.a.message = smalloc(c->u.a.totallen);
3342 memcpy(c->u.a.message, c->u.a.msglen, 4);
3343 }
3344 if (c->u.a.lensofar >= 4 && len > 0) {
3345 int l =
3346 min(c->u.a.totallen - c->u.a.lensofar,
3347 len);
3348 memcpy(c->u.a.message + c->u.a.lensofar, p,
3349 l);
3350 p += l;
3351 len -= l;
3352 c->u.a.lensofar += l;
3353 }
3354 if (c->u.a.lensofar == c->u.a.totallen) {
3355 void *reply, *sentreply;
3356 int replylen;
3357 agent_query(c->u.a.message,
3358 c->u.a.totallen, &reply,
3359 &replylen);
3360 if (reply)
3361 sentreply = reply;
3362 else {
3363 /* Fake SSH_AGENT_FAILURE. */
3364 sentreply = "\0\0\0\1\5";
3365 replylen = 5;
3366 }
3367 send_packet(SSH1_MSG_CHANNEL_DATA,
3368 PKT_INT, c->remoteid,
3369 PKT_INT, replylen,
3370 PKT_DATA, sentreply, replylen,
3371 PKT_END);
3372 if (reply)
3373 sfree(reply);
3374 sfree(c->u.a.message);
3375 c->u.a.lensofar = 0;
3376 }
3377 }
5471d09a 3378 bufsize = 0; /* agent channels never back up */
32874aea 3379 break;
3380 }
90347b95 3381 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3382 c->v.v1.throttling = 1;
3383 ssh1_throttle(+1);
3384 }
32874aea 3385 }
e5574168 3386 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3387 /* may be from EXEC_SHELL on some servers */
e5574168 3388 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3389 /* may be from EXEC_SHELL on some servers
374330e2 3390 * if no pty is available or in other odd cases. Ignore */
e5574168 3391 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3392 char buf[100];
3393 ssh_exitcode = GET_32BIT(pktin.body);
3394 sprintf(buf, "Server sent command exit status %d",
3395 ssh_exitcode);
3396 logevent(buf);
e5574168 3397 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3398 /*
3399 * In case `helpful' firewalls or proxies tack
3400 * extra human-readable text on the end of the
3401 * session which we might mistake for another
3402 * encrypted packet, we close the session once
3403 * we've sent EXIT_CONFIRMATION.
3404 */
3405 ssh_state = SSH_STATE_CLOSED;
3406 crReturnV;
374330e2 3407 } else {
8d5de777 3408 bombout(("Strange packet received: type %d", pktin.type));
32874aea 3409 crReturnV;
374330e2 3410 }
3411 } else {
8df7a775 3412 while (inlen > 0) {
3413 int len = min(inlen, 512);
3414 send_packet(SSH1_CMSG_STDIN_DATA,
3415 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3416 in += len;
3417 inlen -= len;
3418 }
374330e2 3419 }
3420 }
3421
3422 crFinishV;
3423}
3424
3425/*
e5574168 3426 * Utility routine for decoding comma-separated strings in KEXINIT.
3427 */
32874aea 3428static int in_commasep_string(char *needle, char *haystack, int haylen)
3429{
e5574168 3430 int needlen = strlen(needle);
3431 while (1) {
32874aea 3432 /*
3433 * Is it at the start of the string?
3434 */
3435 if (haylen >= needlen && /* haystack is long enough */
3436 !memcmp(needle, haystack, needlen) && /* initial match */
3437 (haylen == needlen || haystack[needlen] == ',')
3438 /* either , or EOS follows */
3439 )
3440 return 1;
3441 /*
3442 * If not, search for the next comma and resume after that.
3443 * If no comma found, terminate.
3444 */
3445 while (haylen > 0 && *haystack != ',')
3446 haylen--, haystack++;
3447 if (haylen == 0)
3448 return 0;
3449 haylen--, haystack++; /* skip over comma itself */
e5574168 3450 }
3451}
3452
3453/*
d39f364a 3454 * SSH2 key creation method.
3455 */
32874aea 3456static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3457 char *keyspace)
3458{
d39f364a 3459 SHA_State s;
3460 /* First 20 bytes. */
3461 SHA_Init(&s);
3462 sha_mpint(&s, K);
3463 SHA_Bytes(&s, H, 20);
3464 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3465 SHA_Bytes(&s, sessid, 20);
d39f364a 3466 SHA_Final(&s, keyspace);
3467 /* Next 20 bytes. */
3468 SHA_Init(&s);
3469 sha_mpint(&s, K);
3470 SHA_Bytes(&s, H, 20);
3471 SHA_Bytes(&s, keyspace, 20);
32874aea 3472 SHA_Final(&s, keyspace + 20);
d39f364a 3473}
3474
3475/*
7cca0d81 3476 * Handle the SSH2 transport layer.
e5574168 3477 */
7cca0d81 3478static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 3479{
ca20bfcf 3480 static int i, j, len, nbits, pbits, warn;
e5574168 3481 static char *str;
a92dd380 3482 static Bignum p, g, e, f, K;
3483 static int kex_init_value, kex_reply_value;
7591b9ff 3484 static const struct ssh_mac **maclist;
8b2715b2 3485 static int nmacs;
0a3f1d48 3486 static const struct ssh2_cipher *cscipher_tobe = NULL;
3487 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 3488 static const struct ssh_mac *csmac_tobe = NULL;
3489 static const struct ssh_mac *scmac_tobe = NULL;
3490 static const struct ssh_compress *cscomp_tobe = NULL;
3491 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 3492 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 3493 static int hostkeylen, siglen;
e055a386 3494 static void *hkey; /* actual host key */
e5574168 3495 static unsigned char exchange_hash[20];
d39f364a 3496 static unsigned char keyspace[40];
ca20bfcf 3497 static int n_preferred_ciphers;
3498 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4ba9b64b 3499 static const struct ssh_compress *preferred_comp;
087abe1a 3500 static int cipherstr_started;
0db56f73 3501 static int first_kex;
e5574168 3502
3503 crBegin;
7cca0d81 3504 random_init();
0db56f73 3505 first_kex = 1;
e5574168 3506
5e8358ad 3507 /*
ca20bfcf 3508 * Set up the preferred ciphers. (NULL => warn below here)
5e8358ad 3509 */
ca20bfcf 3510 n_preferred_ciphers = 0;
3511 for (i = 0; i < CIPHER_MAX; i++) {
3512 switch (cfg.ssh_cipherlist[i]) {
3513 case CIPHER_BLOWFISH:
3514 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3515 n_preferred_ciphers++;
3516 break;
3517 case CIPHER_DES:
087abe1a 3518 if (cfg.ssh2_des_cbc) {
3519 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3520 n_preferred_ciphers++;
3521 }
ca20bfcf 3522 break;
3523 case CIPHER_3DES:
3524 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3525 n_preferred_ciphers++;
3526 break;
3527 case CIPHER_AES:
3528 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3529 n_preferred_ciphers++;
3530 break;
3531 case CIPHER_WARN:
3532 /* Flag for later. Don't bother if it's the last in
3533 * the list. */
3534 if (i < CIPHER_MAX - 1) {
3535 preferred_ciphers[n_preferred_ciphers] = NULL;
3536 n_preferred_ciphers++;
3537 }
3538 break;
3539 }
5e8358ad 3540 }
ca20bfcf 3541
3542 /*
3543 * Set up preferred compression.
3544 */
4ba9b64b 3545 if (cfg.compression)
3546 preferred_comp = &ssh_zlib;
3547 else
3548 preferred_comp = &ssh_comp_none;
5e8358ad 3549
7591b9ff 3550 /*
3551 * Be prepared to work around the buggy MAC problem.
3552 */
7d503c31 3553 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
32874aea 3554 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 3555 else
32874aea 3556 maclist = macs, nmacs = lenof(macs);
7591b9ff 3557
32874aea 3558 begin_key_exchange:
e5574168 3559 /*
3560 * Construct and send our key exchange packet.
3561 */
3562 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3563 for (i = 0; i < 16; i++)
32874aea 3564 ssh2_pkt_addbyte((unsigned char) random_byte());
e5574168 3565 /* List key exchange algorithms. */
3566 ssh2_pkt_addstring_start();
3567 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3568 ssh2_pkt_addstring_str(kex_algs[i]->name);
3569 if (i < lenof(kex_algs) - 1)
3570 ssh2_pkt_addstring_str(",");
e5574168 3571 }
3572 /* List server host key algorithms. */
3573 ssh2_pkt_addstring_start();
3574 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3575 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3576 if (i < lenof(hostkey_algs) - 1)
3577 ssh2_pkt_addstring_str(",");
e5574168 3578 }
3579 /* List client->server encryption algorithms. */
3580 ssh2_pkt_addstring_start();
087abe1a 3581 cipherstr_started = 0;
ca20bfcf 3582 for (i = 0; i < n_preferred_ciphers; i++) {
3583 const struct ssh2_ciphers *c = preferred_ciphers[i];
3584 if (!c) continue; /* warning flag */
32874aea 3585 for (j = 0; j < c->nciphers; j++) {
087abe1a 3586 if (cipherstr_started)
32874aea 3587 ssh2_pkt_addstring_str(",");
087abe1a 3588 ssh2_pkt_addstring_str(c->list[j]->name);
3589 cipherstr_started = 1;
32874aea 3590 }
e5574168 3591 }
3592 /* List server->client encryption algorithms. */
3593 ssh2_pkt_addstring_start();
087abe1a 3594 cipherstr_started = 0;
ca20bfcf 3595 for (i = 0; i < n_preferred_ciphers; i++) {
3596 const struct ssh2_ciphers *c = preferred_ciphers[i];
3597 if (!c) continue; /* warning flag */
32874aea 3598 for (j = 0; j < c->nciphers; j++) {
087abe1a 3599 if (cipherstr_started)
32874aea 3600 ssh2_pkt_addstring_str(",");
087abe1a 3601 ssh2_pkt_addstring_str(c->list[j]->name);
3602 cipherstr_started = 1;
32874aea 3603 }
e5574168 3604 }
3605 /* List client->server MAC algorithms. */
3606 ssh2_pkt_addstring_start();
8b2715b2 3607 for (i = 0; i < nmacs; i++) {
32874aea 3608 ssh2_pkt_addstring_str(maclist[i]->name);
3609 if (i < nmacs - 1)
3610 ssh2_pkt_addstring_str(",");
e5574168 3611 }
3612 /* List server->client MAC algorithms. */
3613 ssh2_pkt_addstring_start();
8b2715b2 3614 for (i = 0; i < nmacs; i++) {
32874aea 3615 ssh2_pkt_addstring_str(maclist[i]->name);
3616 if (i < nmacs - 1)
3617 ssh2_pkt_addstring_str(",");
e5574168 3618 }
3619 /* List client->server compression algorithms. */
3620 ssh2_pkt_addstring_start();
32874aea 3621 for (i = 0; i < lenof(compressions) + 1; i++) {
3622 const struct ssh_compress *c =
3623 i == 0 ? preferred_comp : compressions[i - 1];
3624 ssh2_pkt_addstring_str(c->name);
3625 if (i < lenof(compressions))
3626 ssh2_pkt_addstring_str(",");
e5574168 3627 }
3628 /* List server->client compression algorithms. */
3629 ssh2_pkt_addstring_start();
32874aea 3630 for (i = 0; i < lenof(compressions) + 1; i++) {
3631 const struct ssh_compress *c =
3632 i == 0 ? preferred_comp : compressions[i - 1];
3633 ssh2_pkt_addstring_str(c->name);
3634 if (i < lenof(compressions))
3635 ssh2_pkt_addstring_str(",");
e5574168 3636 }
3637 /* List client->server languages. Empty list. */
3638 ssh2_pkt_addstring_start();
3639 /* List server->client languages. Empty list. */
3640 ssh2_pkt_addstring_start();
3641 /* First KEX packet does _not_ follow, because we're not that brave. */
3642 ssh2_pkt_addbool(FALSE);
3643 /* Reserved. */
3644 ssh2_pkt_adduint32(0);
0db56f73 3645
3646 exhash = exhashbase;
32874aea 3647 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
0db56f73 3648
e5574168 3649 ssh2_pkt_send();
3650
32874aea 3651 if (!ispkt)
3652 crWaitUntil(ispkt);
3653 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
e5574168 3654
3655 /*
3656 * Now examine the other side's KEXINIT to see what we're up
3657 * to.
3658 */
7cca0d81 3659 if (pktin.type != SSH2_MSG_KEXINIT) {
32874aea 3660 bombout(("expected key exchange packet from server"));
3661 crReturn(0);
7cca0d81 3662 }
32874aea 3663 kex = NULL;
3664 hostkey = NULL;
3665 cscipher_tobe = NULL;
3666 sccipher_tobe = NULL;
3667 csmac_tobe = NULL;
3668 scmac_tobe = NULL;
3669 cscomp_tobe = NULL;
3670 sccomp_tobe = NULL;
3671 pktin.savedpos += 16; /* skip garbage cookie */
e5574168 3672 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3673 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3674 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3675 kex = kex_algs[i];
3676 break;
3677 }
e5574168 3678 }
3679 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3680 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3681 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3682 hostkey = hostkey_algs[i];
3683 break;
3684 }
e5574168 3685 }
3686 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
ca20bfcf 3687 warn = 0;
3688 for (i = 0; i < n_preferred_ciphers; i++) {
3689 const struct ssh2_ciphers *c = preferred_ciphers[i];
3690 if (!c) {
3691 warn = 1;
3692 } else {
3693 for (j = 0; j < c->nciphers; j++) {
3694 if (in_commasep_string(c->list[j]->name, str, len)) {
3695 cscipher_tobe = c->list[j];
3696 break;
3697 }
32874aea 3698 }
3699 }
ca20bfcf 3700 if (cscipher_tobe) {
3701 if (warn)
3702 askcipher(cscipher_tobe->name, 1);
32874aea 3703 break;
ca20bfcf 3704 }
e5574168 3705 }
0ef8f407 3706 if (!cscipher_tobe) {
3707 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3708 crReturn(0);
3709 }
3710
e5574168 3711 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
ca20bfcf 3712 warn = 0;
3713 for (i = 0; i < n_preferred_ciphers; i++) {
3714 const struct ssh2_ciphers *c = preferred_ciphers[i];
3715 if (!c) {
3716 warn = 1;
3717 } else {
3718 for (j = 0; j < c->nciphers; j++) {
3719 if (in_commasep_string(c->list[j]->name, str, len)) {
3720 sccipher_tobe = c->list[j];
3721 break;
3722 }
32874aea 3723 }
3724 }
ca20bfcf 3725 if (sccipher_tobe) {
3726 if (warn)
3727 askcipher(sccipher_tobe->name, 2);
32874aea 3728 break;
ca20bfcf 3729 }
e5574168 3730 }
0ef8f407 3731 if (!sccipher_tobe) {
3732 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3733 crReturn(0);
3734 }
3735
e5574168 3736 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 3737 for (i = 0; i < nmacs; i++) {
32874aea 3738 if (in_commasep_string(maclist[i]->name, str, len)) {
3739 csmac_tobe = maclist[i];
3740 break;
3741 }
e5574168 3742 }
3743 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 3744 for (i = 0; i < nmacs; i++) {
32874aea 3745 if (in_commasep_string(maclist[i]->name, str, len)) {
3746 scmac_tobe = maclist[i];
3747 break;
3748 }
e5574168 3749 }
3750 ssh2_pkt_getstring(&str, &len); /* client->server compression */
32874aea 3751 for (i = 0; i < lenof(compressions) + 1; i++) {
3752 const struct ssh_compress *c =
3753 i == 0 ? preferred_comp : compressions[i - 1];
3754 if (in_commasep_string(c->name, str, len)) {
3755 cscomp_tobe = c;
3756 break;
3757 }
e5574168 3758 }
3759 ssh2_pkt_getstring(&str, &len); /* server->client compression */
32874aea 3760 for (i = 0; i < lenof(compressions) + 1; i++) {
3761 const struct ssh_compress *c =
3762 i == 0 ? preferred_comp : compressions[i - 1];
3763 if (in_commasep_string(c->name, str, len)) {
3764 sccomp_tobe = c;
3765 break;
3766 }
e5574168 3767 }
e5574168 3768
3769 /*
7bd5a860 3770 * Work out the number of bits of key we will need from the key
3771 * exchange. We start with the maximum key length of either
3772 * cipher...
3773 */
3774 {
32874aea 3775 int csbits, scbits;
7bd5a860 3776
3777 csbits = cscipher_tobe->keylen;
3778 scbits = sccipher_tobe->keylen;
3779 nbits = (csbits > scbits ? csbits : scbits);
3780 }
3781 /* The keys only have 160-bit entropy, since they're based on
3782 * a SHA-1 hash. So cap the key size at 160 bits. */
32874aea 3783 if (nbits > 160)
3784 nbits = 160;
7bd5a860 3785
3786 /*
a92dd380 3787 * If we're doing Diffie-Hellman group exchange, start by
3788 * requesting a group.
e5574168 3789 */
a92dd380 3790 if (kex == &ssh_diffiehellman_gex) {
32874aea 3791 logevent("Doing Diffie-Hellman group exchange");
00db133f 3792 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 3793 /*
3794 * Work out how big a DH group we will need to allow that
3795 * much data.
7bd5a860 3796 */
32874aea 3797 pbits = 512 << ((nbits - 1) / 64);
3798 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3799 ssh2_pkt_adduint32(pbits);
3800 ssh2_pkt_send();
3801
3802 crWaitUntil(ispkt);
3803 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3804 bombout(("expected key exchange group packet from server"));
3805 crReturn(0);
3806 }
3807 p = ssh2_pkt_getmp();
3808 g = ssh2_pkt_getmp();
3809 dh_setup_group(p, g);
3810 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3811 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3812 } else {
00db133f 3813 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
32874aea 3814 dh_setup_group1();
3815 kex_init_value = SSH2_MSG_KEXDH_INIT;
3816 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3817 }
e5574168 3818
a92dd380 3819 logevent("Doing Diffie-Hellman key exchange");
e5574168 3820 /*
a92dd380 3821 * Now generate and send e for Diffie-Hellman.
e5574168 3822 */
32874aea 3823 e = dh_create_e(nbits * 2);
a92dd380 3824 ssh2_pkt_init(kex_init_value);
e5574168 3825 ssh2_pkt_addmp(e);
3826 ssh2_pkt_send();
3827
3828 crWaitUntil(ispkt);
a92dd380 3829 if (pktin.type != kex_reply_value) {
32874aea 3830 bombout(("expected key exchange reply packet from server"));
3831 crReturn(0);
7cca0d81 3832 }
e5574168 3833 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3834 f = ssh2_pkt_getmp();
e5574168 3835 ssh2_pkt_getstring(&sigdata, &siglen);
3836
3837 K = dh_find_K(f);
e5574168 3838
3839 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 3840 if (kex == &ssh_diffiehellman_gex) {
32874aea 3841 sha_uint32(&exhash, pbits);
3842 sha_mpint(&exhash, p);
3843 sha_mpint(&exhash, g);
a92dd380 3844 }
e5574168 3845 sha_mpint(&exhash, e);
3846 sha_mpint(&exhash, f);
3847 sha_mpint(&exhash, K);
3848 SHA_Final(&exhash, exchange_hash);
3849
3709bfe9 3850 dh_cleanup();
3851
7cca0d81 3852#if 0
765c4200 3853 debug(("Exchange hash is:\n"));
3854 dmemdump(exchange_hash, 20);
7cca0d81 3855#endif
3856
e055a386 3857 hkey = hostkey->newkey(hostkeydata, hostkeylen);
f7259d10 3858 if (!hkey ||
3859 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3860 bombout(("Server's host key did not match the signature supplied"));
32874aea 3861 crReturn(0);
8d5de777 3862 }
e5574168 3863
3864 /*
7cca0d81 3865 * Authenticate remote host: verify host key. (We've already
3866 * checked the signature of the exchange hash.)
e5574168 3867 */
e055a386 3868 keystr = hostkey->fmtkey(hkey);
3869 fingerprint = hostkey->fingerprint(hkey);
d4857987 3870 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
32874aea 3871 keystr, fingerprint);
3872 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 3873 logevent("Host key fingerprint is:");
3874 logevent(fingerprint);
3875 }
dcbde236 3876 sfree(fingerprint);
3877 sfree(keystr);
e055a386 3878 hostkey->freekey(hkey);
d39f364a 3879
3880 /*
7cca0d81 3881 * Send SSH2_MSG_NEWKEYS.
d39f364a 3882 */
3883 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3884 ssh2_pkt_send();
d39f364a 3885
3886 /*
8406eaf9 3887 * Expect SSH2_MSG_NEWKEYS from server.
3888 */
3889 crWaitUntil(ispkt);
3890 if (pktin.type != SSH2_MSG_NEWKEYS) {
3891 bombout(("expected new-keys packet from server"));
3892 crReturn(0);
3893 }
3894
3895 /*
d39f364a 3896 * Create and initialise session keys.
3897 */
3898 cscipher = cscipher_tobe;
3899 sccipher = sccipher_tobe;
3900 csmac = csmac_tobe;
3901 scmac = scmac_tobe;
3902 cscomp = cscomp_tobe;
3903 sccomp = sccomp_tobe;
4ba9b64b 3904 cscomp->compress_init();
3905 sccomp->decompress_init();
d39f364a 3906 /*
5e0d7cb8 3907 * Set IVs after keys. Here we use the exchange hash from the
3908 * _first_ key exchange.
d39f364a 3909 */
5e0d7cb8 3910 if (first_kex)
65a22376 3911 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3912 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 3913 cscipher->setcskey(keyspace);
65a22376 3914 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 3915 sccipher->setsckey(keyspace);
65a22376 3916 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 3917 cscipher->setcsiv(keyspace);
65a22376 3918 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 3919 sccipher->setsciv(keyspace);
65a22376 3920 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 3921 csmac->setcskey(keyspace);
65a22376 3922 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 3923 scmac->setsckey(keyspace);
d39f364a 3924
033b4cef 3925 /*
0db56f73 3926 * If this is the first key exchange phase, we must pass the
3927 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3928 * wants to see it but because it will need time to initialise
3929 * itself before it sees an actual packet. In subsequent key
3930 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3931 * it would only confuse the layer above.
3932 */
3933 if (!first_kex) {
32874aea 3934 crReturn(0);
0db56f73 3935 }
3936 first_kex = 0;
3937
3938 /*
7cca0d81 3939 * Now we're encrypting. Begin returning 1 to the protocol main
3940 * function so that other things can run on top of the
3941 * transport. If we ever see a KEXINIT, we must go back to the
3942 * start.
033b4cef 3943 */
e96adf72 3944 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 3945 crReturn(1);
e96adf72 3946 }
5e0d7cb8 3947 logevent("Server initiated key re-exchange");
7cca0d81 3948 goto begin_key_exchange;
e5574168 3949
3950 crFinish(1);
3951}
3952
7cca0d81 3953/*
783415f8 3954 * Add data to an SSH2 channel output buffer.
3955 */
32874aea 3956static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3957 int len)
3958{
5471d09a 3959 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 3960}
3961
3962/*
3963 * Attempt to send data on an SSH2 channel.
3964 */
5471d09a 3965static int ssh2_try_send(struct ssh_channel *c)
32874aea 3966{
5471d09a 3967 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3968 int len;
3969 void *data;
3970 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3971 if ((unsigned)len > c->v.v2.remwindow)
3972 len = c->v.v2.remwindow;
3973 if ((unsigned)len > c->v.v2.remmaxpkt)
3974 len = c->v.v2.remmaxpkt;
32874aea 3975 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3976 ssh2_pkt_adduint32(c->remoteid);
3977 ssh2_pkt_addstring_start();
5471d09a 3978 ssh2_pkt_addstring_data(data, len);
32874aea 3979 ssh2_pkt_send();
5471d09a 3980 bufchain_consume(&c->v.v2.outbuffer, len);
3981 c->v.v2.remwindow -= len;
3982 }
3983
3984 /*
3985 * After having sent as much data as we can, return the amount
3986 * still buffered.
3987 */
3988 return bufchain_size(&c->v.v2.outbuffer);
3989}
3990
3991/*
3992 * Potentially enlarge the window on an SSH2 channel.
3993 */
3994static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3995{
6b69f42e 3996 /*
3997 * Never send WINDOW_ADJUST for a channel that the remote side
3998 * already thinks it's closed; there's no point, since it won't
3999 * be sending any more data anyway.
4000 */
4001 if (c->closes != 0)
4002 return;
4003
5471d09a 4004 if (newwin > c->v.v2.locwindow) {
4005 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4006 ssh2_pkt_adduint32(c->remoteid);
4007 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
4008 ssh2_pkt_send();
4009 c->v.v2.locwindow = newwin;
783415f8 4010 }
4011}
4012
4013/*
7cca0d81 4014 * Handle the SSH2 userauth and connection layers.
4015 */
4016static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
4017{
65a22376 4018 static enum {
32874aea 4019 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
761187b6 4020 AUTH_PASSWORD,
4021 AUTH_KEYBOARD_INTERACTIVE
65a22376 4022 } method;
1408a877 4023 static enum {
32874aea 4024 AUTH_TYPE_NONE,
4025 AUTH_TYPE_PUBLICKEY,
4026 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4027 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
761187b6 4028 AUTH_TYPE_PASSWORD,
4bdf7c46 4029 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4030 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
1408a877 4031 } type;
761187b6 4032 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4033 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
b3186d64 4034 static int kbd_inter_running;
1408a877 4035 static int we_are_in;
45068b27 4036 static int num_prompts, curr_prompt, echo;
65a22376 4037 static char username[100];
7e9b7f4b 4038 static int got_username;
65a22376 4039 static char pwprompt[200];
4040 static char password[100];
396778f1 4041 static void *publickey_blob;
4042 static int publickey_bloblen;
7cca0d81 4043
e5574168 4044 crBegin;
4045
7cca0d81 4046 /*
4047 * Request userauth protocol, and await a response to it.
4048 */
4049 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4050 ssh2_pkt_addstring("ssh-userauth");
4051 ssh2_pkt_send();
4052 crWaitUntilV(ispkt);
8d5de777 4053 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 4054 bombout(("Server refused user authentication protocol"));
4055 crReturnV;
8d5de777 4056 }
7cca0d81 4057
4058 /*
1408a877 4059 * We repeat this whole loop, including the username prompt,
4060 * until we manage a successful authentication. If the user
4061 * types the wrong _password_, they are sent back to the
4062 * beginning to try another username. (If they specify a
4063 * username in the config, they are never asked, even if they
4064 * do give a wrong password.)
4065 *
4066 * I think this best serves the needs of
4067 *
4068 * - the people who have no configuration, no keys, and just
4069 * want to try repeated (username,password) pairs until they
4070 * type both correctly
4071 *
4072 * - people who have keys and configuration but occasionally
4073 * need to fall back to passwords
4074 *
4075 * - people with a key held in Pageant, who might not have
4076 * logged in to a particular machine before; so they want to
4077 * type a username, and then _either_ their key will be
4078 * accepted, _or_ they will type a password. If they mistype
4079 * the username they will want to be able to get back and
4080 * retype it!
7cca0d81 4081 */
5bb641e1 4082 username[0] = '\0';
7e9b7f4b 4083 got_username = FALSE;
1408a877 4084 do {
4085 static int pos;
7cca0d81 4086 static char c;
e5574168 4087
1408a877 4088 /*
4089 * Get a username.
4090 */
4091 pos = 0;
7e9b7f4b 4092 if (got_username && !cfg.change_username) {
5bb641e1 4093 /*
4094 * We got a username last time round this loop, and
4095 * with change_username turned off we don't try to get
4096 * it again.
4097 */
4098 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
c0a81592 4099 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4100 if (!ssh_get_line("login as: ",
4101 username, sizeof(username), FALSE)) {
4102 /*
4103 * get_line failed to get a username.
4104 * Terminate.
4105 */
4106 logevent("No username provided. Abandoning session.");
4107 ssh_state = SSH_STATE_CLOSED;
4108 crReturnV;
4109 }
4110 } else {
4111 c_write_str("login as: ");
4112 ssh_send_ok = 1;
4113 while (pos >= 0) {
4114 crWaitUntilV(!ispkt);
4115 while (inlen--)
4116 switch (c = *in++) {
4117 case 10:
4118 case 13:
4119 username[pos] = 0;
4120 pos = -1;
4121 break;
4122 case 8:
4123 case 127:
4124 if (pos > 0) {
4125 c_write_str("\b \b");
4126 pos--;
4127 }
4128 break;
4129 case 21:
4130 case 27:
4131 while (pos > 0) {
4132 c_write_str("\b \b");
4133 pos--;
4134 }
4135 break;
4136 case 3:
4137 case 4:
93b581bd 4138 cleanup_exit(0);
32874aea 4139 break;
4140 default:
4141 if (((c >= ' ' && c <= '~') ||
51b2fb65 4142 ((unsigned char) c >= 160))
4143 && pos < sizeof(username)-1) {
32874aea 4144 username[pos++] = c;
4145 c_write(&c, 1);
4146 }
4147 break;
4148 }
4149 }
4150 }
1408a877 4151 c_write_str("\r\n");
7cca0d81 4152 username[strcspn(username, "\n\r")] = '\0';
4153 } else {
4154 char stuff[200];
4155 strncpy(username, cfg.username, 99);
4156 username[99] = '\0';
65a22376 4157 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 4158 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 4159 c_write_str(stuff);
7cca0d81 4160 }
4161 }
7e9b7f4b 4162 got_username = TRUE;
7cca0d81 4163
65a22376 4164 /*
1408a877 4165 * Send an authentication request using method "none": (a)
4166 * just in case it succeeds, and (b) so that we know what
4167 * authentication methods we can usefully try next.
65a22376 4168 */
00db133f 4169 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4170
1408a877 4171 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4172 ssh2_pkt_addstring(username);
32874aea 4173 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4174 ssh2_pkt_addstring("none"); /* method */
4175 ssh2_pkt_send();
4176 type = AUTH_TYPE_NONE;
4177 gotit = FALSE;
4178 we_are_in = FALSE;
7cca0d81 4179
1408a877 4180 tried_pubkey_config = FALSE;
1983e559 4181 tried_agent = FALSE;
b3186d64 4182 tried_keyb_inter = FALSE;
4183 kbd_inter_running = FALSE;
396778f1 4184 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4185 if (*cfg.keyfile) {
231ee168 4186 int keytype;
4187 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4188 keytype = key_type(cfg.keyfile);
4189 if (keytype == SSH_KEYTYPE_SSH2)
4190 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4191 &publickey_bloblen);
4192 else {
4193 char msgbuf[256];
4194 logeventf("Unable to use this key file (%s)",
4195 key_type_to_str(keytype));
4196 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4197 cfg.keyfile, key_type_to_str(keytype));
4198 c_write_str(msgbuf);
4199 publickey_blob = NULL;
4200 }
396778f1 4201 } else
4202 publickey_blob = NULL;
65a22376 4203
1408a877 4204 while (1) {
4205 /*
4206 * Wait for the result of the last authentication request.
4207 */
4208 if (!gotit)
4209 crWaitUntilV(ispkt);
4210 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4211 char *banner;
4212 int size;
4213 /*
4214 * Don't show the banner if we're operating in
4215 * non-verbose non-interactive mode. (It's probably
4216 * a script, which means nobody will read the
4217 * banner _anyway_, and moreover the printing of
4218 * the banner will screw up processing on the
4219 * output of (say) plink.)
4220 */
4221 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4222 ssh2_pkt_getstring(&banner, &size);
4223 if (banner)
4224 c_write_untrusted(banner, size);
4225 }
1408a877 4226 crWaitUntilV(ispkt);
4227 }
4228 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4229 logevent("Access granted");
4230 we_are_in = TRUE;
4231 break;
4232 }
65a22376 4233
b3186d64 4234 if (kbd_inter_running &&
4235 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4236 /*
45068b27 4237 * This is either a further set-of-prompts packet
4238 * in keyboard-interactive authentication, or it's
4239 * the same one and we came back here with `gotit'
4240 * set. In the former case, we must reset the
4241 * curr_prompt variable.
b3186d64 4242 */
45068b27 4243 if (!gotit)
4244 curr_prompt = 0;
6bb26b30 4245 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
b3186d64 4246 bombout(("Strange packet received during authentication: type %d",
1408a877 4247 pktin.type));
38c4a8da 4248 crReturnV;
65a22376 4249 }
4250
1408a877 4251 gotit = FALSE;
65a22376 4252
1408a877 4253 /*
4254 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4255 * we can look at the string in it and know what we can
4256 * helpfully try next.
4257 */
b3186d64 4258 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4259 char *methods;
4260 int methlen;
4261 ssh2_pkt_getstring(&methods, &methlen);
b3186d64 4262 kbd_inter_running = FALSE;
1408a877 4263 if (!ssh2_pkt_getbool()) {
4264 /*
4265 * We have received an unequivocal Access
4266 * Denied. This can translate to a variety of
4267 * messages:
4268 *
4269 * - if we'd just tried "none" authentication,
4270 * it's not worth printing anything at all
4271 *
4272 * - if we'd just tried a public key _offer_,
4273 * the message should be "Server refused our
4274 * key" (or no message at all if the key
4275 * came from Pageant)
4276 *
4277 * - if we'd just tried anything else, the
4278 * message really should be "Access denied".
4279 *
4280 * Additionally, if we'd just tried password
4281 * authentication, we should break out of this
4282 * whole loop so as to go back to the username
4283 * prompt.
4284 */
4285 if (type == AUTH_TYPE_NONE) {
4286 /* do nothing */
4287 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4288 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4289 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4290 c_write_str("Server refused our key\r\n");
4291 logevent("Server refused public key");
4bdf7c46 4292 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4293 /* server declined keyboard-interactive; ignore */
1408a877 4294 } else {
4295 c_write_str("Access denied\r\n");
4296 logevent("Access denied");
4297 if (type == AUTH_TYPE_PASSWORD) {
4298 we_are_in = FALSE;
4299 break;
4300 }
4301 }
4302 } else {
4303 c_write_str("Further authentication required\r\n");
4304 logevent("Further authentication required");
4305 }
65a22376 4306
32874aea 4307 can_pubkey =
4308 in_commasep_string("publickey", methods, methlen);
4309 can_passwd =
4310 in_commasep_string("password", methods, methlen);
f091e308 4311 can_keyb_inter = cfg.try_ki_auth &&
761187b6 4312 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4313 }
65a22376 4314
1408a877 4315 method = 0;
00db133f 4316 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4317
78afa559 4318 if (!method && can_pubkey && agent_exists() && !tried_agent) {
1983e559 4319 /*
4320 * Attempt public-key authentication using Pageant.
4321 */
4322 static unsigned char request[5], *response, *p;
4323 static int responselen;
4324 static int i, nkeys;
4325 static int authed = FALSE;
4326 void *r;
4327
c0a81592 4328 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4329 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4330
1983e559 4331 tried_agent = TRUE;
4332
4333 logevent("Pageant is running. Requesting keys.");
4334
4335 /* Request the keys held by the agent. */
4336 PUT_32BIT(request, 1);
4337 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4338 agent_query(request, 5, &r, &responselen);
32874aea 4339 response = (unsigned char *) r;
95797139 4340 if (response && responselen >= 5 &&
32874aea 4341 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 4342 p = response + 5;
32874aea 4343 nkeys = GET_32BIT(p);
4344 p += 4;
4345 {
4346 char buf[64];
4347 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4348 logevent(buf);
4349 }
1983e559 4350 for (i = 0; i < nkeys; i++) {
4351 static char *pkblob, *alg, *commentp;
4352 static int pklen, alglen, commentlen;
4353 static int siglen, retlen, len;
4354 static char *q, *agentreq, *ret;
2d466ffd 4355 void *vret;
1983e559 4356
32874aea 4357 {
4358 char buf[64];
4359 sprintf(buf, "Trying Pageant key #%d", i);
4360 logevent(buf);
4361 }
4362 pklen = GET_32BIT(p);
4363 p += 4;
396778f1 4364 if (publickey_blob &&
4365 pklen == publickey_bloblen &&
4366 !memcmp(p, publickey_blob, publickey_bloblen)) {
4367 logevent("This key matches configured key file");
4368 tried_pubkey_config = 1;
4369 }
32874aea 4370 pkblob = p;
4371 p += pklen;
1983e559 4372 alglen = GET_32BIT(pkblob);
4373 alg = pkblob + 4;
32874aea 4374 commentlen = GET_32BIT(p);
4375 p += 4;
4376 commentp = p;
4377 p += commentlen;
1983e559 4378 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4379 ssh2_pkt_addstring(username);
32874aea 4380 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4381 ssh2_pkt_addstring("publickey"); /* method */
4382 ssh2_pkt_addbool(FALSE); /* no signature included */
1983e559 4383 ssh2_pkt_addstring_start();
4384 ssh2_pkt_addstring_data(alg, alglen);
4385 ssh2_pkt_addstring_start();
4386 ssh2_pkt_addstring_data(pkblob, pklen);
4387 ssh2_pkt_send();
4388
4389 crWaitUntilV(ispkt);
4390 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4391 logevent("Key refused");
4392 continue;
4393 }
4394
32874aea 4395 if (flags & FLAG_VERBOSE) {
4396 c_write_str
4397 ("Authenticating with public key \"");
4398 c_write(commentp, commentlen);
4399 c_write_str("\" from agent\r\n");
4400 }
1983e559 4401
4402 /*
4403 * Server is willing to accept the key.
4404 * Construct a SIGN_REQUEST.
4405 */
4406 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4407 ssh2_pkt_addstring(username);
32874aea 4408 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4409 ssh2_pkt_addstring("publickey"); /* method */
1983e559 4410 ssh2_pkt_addbool(TRUE);
4411 ssh2_pkt_addstring_start();
4412 ssh2_pkt_addstring_data(alg, alglen);
4413 ssh2_pkt_addstring_start();
4414 ssh2_pkt_addstring_data(pkblob, pklen);
4415
4416 siglen = pktout.length - 5 + 4 + 20;
32874aea 4417 len = 1; /* message type */
4418 len += 4 + pklen; /* key blob */
4419 len += 4 + siglen; /* data to sign */
4420 len += 4; /* flags */
1983e559 4421 agentreq = smalloc(4 + len);
4422 PUT_32BIT(agentreq, len);
4423 q = agentreq + 4;
4424 *q++ = SSH2_AGENTC_SIGN_REQUEST;
32874aea 4425 PUT_32BIT(q, pklen);
4426 q += 4;
4427 memcpy(q, pkblob, pklen);
4428 q += pklen;
4429 PUT_32BIT(q, siglen);
4430 q += 4;
1983e559 4431 /* Now the data to be signed... */
32874aea 4432 PUT_32BIT(q, 20);
4433 q += 4;
4434 memcpy(q, ssh2_session_id, 20);
4435 q += 20;
4436 memcpy(q, pktout.data + 5, pktout.length - 5);
4437 q += pktout.length - 5;
1983e559 4438 /* And finally the (zero) flags word. */
4439 PUT_32BIT(q, 0);
2d466ffd 4440 agent_query(agentreq, len + 4, &vret, &retlen);
4441 ret = vret;
1983e559 4442 sfree(agentreq);
4443 if (ret) {
4444 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4445 logevent("Sending Pageant's response");
1dd353b5 4446 ssh2_add_sigblob(pkblob, pklen,
4447 ret + 9, GET_32BIT(ret + 5));
1983e559 4448 ssh2_pkt_send();
4449 authed = TRUE;
4450 break;
4451 } else {
32874aea 4452 logevent
4453 ("Pageant failed to answer challenge");
1983e559 4454 sfree(ret);
4455 }
4456 }
4457 }
4458 if (authed)
4459 continue;
4460 }
4461 }
4462
231ee168 4463 if (!method && can_pubkey && publickey_blob
32874aea 4464 && !tried_pubkey_config) {
1408a877 4465 unsigned char *pub_blob;
4466 char *algorithm, *comment;
4467 int pub_blob_len;
65a22376 4468
1408a877 4469 tried_pubkey_config = TRUE;
65a22376 4470
c0a81592 4471 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4472 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4473
65a22376 4474 /*
1408a877 4475 * Try the public key supplied in the configuration.
4476 *
4477 * First, offer the public blob to see if the server is
4478 * willing to accept it.
65a22376 4479 */
1408a877 4480 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4481 &pub_blob_len);
4482 if (pub_blob) {
4483 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4484 ssh2_pkt_addstring(username);
32874aea 4485 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4486 ssh2_pkt_addstring("publickey"); /* method */
4487 ssh2_pkt_addbool(FALSE); /* no signature included */
1408a877 4488 ssh2_pkt_addstring(algorithm);
4489 ssh2_pkt_addstring_start();
4490 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4491 ssh2_pkt_send();
32874aea 4492 logevent("Offered public key"); /* FIXME */
1408a877 4493
4494 crWaitUntilV(ispkt);
4495 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4496 gotit = TRUE;
4497 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4498 continue; /* key refused; give up on it */
1408a877 4499 }
65a22376 4500
1408a877 4501 logevent("Offer of public key accepted");
65a22376 4502 /*
1408a877 4503 * Actually attempt a serious authentication using
4504 * the key.
65a22376 4505 */
1408a877 4506 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
32874aea 4507 sprintf(pwprompt,
4508 "Passphrase for key \"%.100s\": ",
4509 comment);
1408a877 4510 need_pw = TRUE;
4511 } else {
4512 need_pw = FALSE;
4513 }
4514 c_write_str("Authenticating with public key \"");
4515 c_write_str(comment);
4516 c_write_str("\"\r\n");
4517 method = AUTH_PUBLICKEY_FILE;
65a22376 4518 }
1408a877 4519 }
4520
af659722 4521 if (!method && can_keyb_inter && !tried_keyb_inter) {
4522 method = AUTH_KEYBOARD_INTERACTIVE;
4523 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4524 tried_keyb_inter = TRUE;
4525
c0a81592 4526 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4527 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4528
af659722 4529 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4530 ssh2_pkt_addstring(username);
4531 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4532 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4533 ssh2_pkt_addstring(""); /* lang */
4534 ssh2_pkt_addstring("");
4535 ssh2_pkt_send();
4536
4537 crWaitUntilV(ispkt);
4538 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4539 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4540 gotit = TRUE;
4541 logevent("Keyboard-interactive authentication refused");
4542 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4543 continue;
4544 }
4545
4546 kbd_inter_running = TRUE;
45068b27 4547 curr_prompt = 0;
af659722 4548 }
4549
4550 if (kbd_inter_running) {
4551 method = AUTH_KEYBOARD_INTERACTIVE;
4552 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4553 tried_keyb_inter = TRUE;
4554
c0a81592 4555 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4556 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4557
45068b27 4558 if (curr_prompt == 0) {
4559 /*
4560 * We've got a fresh USERAUTH_INFO_REQUEST.
4561 * Display header data, and start going through
4562 * the prompts.
4563 */
4564 char *name, *inst, *lang;
4565 int name_len, inst_len, lang_len;
4566
af659722 4567 ssh2_pkt_getstring(&name, &name_len);
4568 ssh2_pkt_getstring(&inst, &inst_len);
4569 ssh2_pkt_getstring(&lang, &lang_len);
45068b27 4570 if (name_len > 0) {
af659722 4571 c_write_untrusted(name, name_len);
45068b27 4572 c_write_str("\n");
4573 }
4574 if (inst_len > 0) {
af659722 4575 c_write_untrusted(inst, inst_len);
45068b27 4576 c_write_str("\n");
4577 }
af659722 4578 num_prompts = ssh2_pkt_getuint32();
45068b27 4579 }
af659722 4580
45068b27 4581 /*
4582 * If there are prompts remaining in the packet,
4583 * display one and get a response.
4584 */
4585 if (curr_prompt < num_prompts) {
4586 char *prompt;
4587 int prompt_len;
af659722 4588
45068b27 4589 ssh2_pkt_getstring(&prompt, &prompt_len);
4590 if (prompt_len > 0) {
4591 strncpy(pwprompt, prompt, sizeof(pwprompt));
4592 pwprompt[prompt_len < sizeof(pwprompt) ?
4593 prompt_len : sizeof(pwprompt)-1] = '\0';
4594 } else {
4595 strcpy(pwprompt,
4596 "<server failed to send prompt>: ");
4597 }
af659722 4598 echo = ssh2_pkt_getbool();
45068b27 4599 need_pw = TRUE;
4600 } else
4601 need_pw = FALSE;
af659722 4602 }
4603
1408a877 4604 if (!method && can_passwd) {
4605 method = AUTH_PASSWORD;
c0a81592 4606 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
00db133f 4607 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
32874aea 4608 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4609 savedhost);
1408a877 4610 need_pw = TRUE;
4611 }
4612
4613 if (need_pw) {
fa17a66e 4614 if (ssh_get_line) {
4615 if (!ssh_get_line(pwprompt, password,
32874aea 4616 sizeof(password), TRUE)) {
1408a877 4617 /*
fa17a66e 4618 * get_line failed to get a password (for
4619 * example because one was supplied on the
4620 * command line which has already failed to
4621 * work). Terminate.
1408a877 4622 */
2bc6a386 4623 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4624 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4625 ssh2_pkt_addstring
4626 ("No more passwords available to try");
4627 ssh2_pkt_addstring("en"); /* language tag */
4628 ssh2_pkt_send();
247308b5 4629 logevent("Unable to authenticate");
2bc6a386 4630 connection_fatal("Unable to authenticate");
1408a877 4631 ssh_state = SSH_STATE_CLOSED;
4632 crReturnV;
4633 }
4634 } else {
4635 static int pos = 0;
4636 static char c;
4637
761187b6 4638 c_write_untrusted(pwprompt, strlen(pwprompt));
1408a877 4639 ssh_send_ok = 1;
4640
4641 pos = 0;
4642 while (pos >= 0) {
4643 crWaitUntilV(!ispkt);
32874aea 4644 while (inlen--)
4645 switch (c = *in++) {
4646 case 10:
4647 case 13:
4648 password[pos] = 0;
4649 pos = -1;
4650 break;
4651 case 8:
4652 case 127:
4653 if (pos > 0)
4654 pos--;
4655 break;
4656 case 21:
4657 case 27:
4658 pos = 0;
4659 break;
4660 case 3:
4661 case 4:
93b581bd 4662 cleanup_exit(0);
32874aea 4663 break;
4664 default:
51b2fb65 4665 if (pos < sizeof(password)-1)
32874aea 4666 password[pos++] = c;
4667 break;
4668 }
65a22376 4669 }
1408a877 4670 c_write_str("\r\n");
65a22376 4671 }
65a22376 4672 }
65a22376 4673
1408a877 4674 if (method == AUTH_PUBLICKEY_FILE) {
4675 /*
4676 * We have our passphrase. Now try the actual authentication.
4677 */
4678 struct ssh2_userkey *key;
65a22376 4679
1408a877 4680 key = ssh2_load_userkey(cfg.keyfile, password);
4681 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4682 if (key == SSH2_WRONG_PASSPHRASE) {
4683 c_write_str("Wrong passphrase\r\n");
4684 tried_pubkey_config = FALSE;
4685 } else {
4686 c_write_str("Unable to load private key\r\n");
4687 tried_pubkey_config = TRUE;
4688 }
4689 /* Send a spurious AUTH_NONE to return to the top. */
4690 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4691 ssh2_pkt_addstring(username);
32874aea 4692 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4693 ssh2_pkt_addstring("none"); /* method */
1408a877 4694 ssh2_pkt_send();
4695 type = AUTH_TYPE_NONE;
4696 } else {
1dd353b5 4697 unsigned char *pkblob, *sigblob, *sigdata;
4698 int pkblob_len, sigblob_len, sigdata_len;
65a22376 4699
1408a877 4700 /*
4701 * We have loaded the private key and the server
4702 * has announced that it's willing to accept it.
4703 * Hallelujah. Generate a signature and send it.
4704 */
4705 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4706 ssh2_pkt_addstring(username);
32874aea 4707 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4708 ssh2_pkt_addstring("publickey"); /* method */
1408a877 4709 ssh2_pkt_addbool(TRUE);
4710 ssh2_pkt_addstring(key->alg->name);
1dd353b5 4711 pkblob = key->alg->public_blob(key->data, &pkblob_len);
1408a877 4712 ssh2_pkt_addstring_start();
1dd353b5 4713 ssh2_pkt_addstring_data(pkblob, pkblob_len);
1408a877 4714
4715 /*
4716 * The data to be signed is:
4717 *
4718 * string session-id
4719 *
4720 * followed by everything so far placed in the
4721 * outgoing packet.
4722 */
4723 sigdata_len = pktout.length - 5 + 4 + 20;
4724 sigdata = smalloc(sigdata_len);
4725 PUT_32BIT(sigdata, 20);
32874aea 4726 memcpy(sigdata + 4, ssh2_session_id, 20);
4727 memcpy(sigdata + 24, pktout.data + 5,
4728 pktout.length - 5);
1dd353b5 4729 sigblob = key->alg->sign(key->data, sigdata,
4730 sigdata_len, &sigblob_len);
4731 ssh2_add_sigblob(pkblob, pkblob_len,
4732 sigblob, sigblob_len);
4733 sfree(pkblob);
4734 sfree(sigblob);
1408a877 4735 sfree(sigdata);
4736
4737 ssh2_pkt_send();
4738 type = AUTH_TYPE_PUBLICKEY;
4739 }
4740 } else if (method == AUTH_PASSWORD) {
65a22376 4741 /*
1408a877 4742 * We send the password packet lumped tightly together with
4743 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4744 * string long enough to make the total length of the two
4745 * packets constant. This should ensure that a passive
4746 * listener doing traffic analyis can't work out the length
4747 * of the password.
4748 *
4749 * For this to work, we need an assumption about the
4750 * maximum length of the password packet. I think 256 is
4751 * pretty conservative. Anyone using a password longer than
4752 * that probably doesn't have much to worry about from
4753 * people who find out how long their password is!
65a22376 4754 */
4755 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4756 ssh2_pkt_addstring(username);
32874aea 4757 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4758 ssh2_pkt_addstring("password");
4759 ssh2_pkt_addbool(FALSE);
4760 ssh2_pkt_addstring(password);
4761 ssh2_pkt_defer();
65a22376 4762 /*
1408a877 4763 * We'll include a string that's an exact multiple of the
4764 * cipher block size. If the cipher is NULL for some
4765 * reason, we don't do this trick at all because we gain
4766 * nothing by it.
65a22376 4767 */
32874aea 4768 if (cscipher) {
4769 int stringlen, i;
4770
4771 stringlen = (256 - deferred_len);
4772 stringlen += cscipher->blksize - 1;
4773 stringlen -= (stringlen % cscipher->blksize);
4774 if (cscomp) {
4775 /*
4776 * Temporarily disable actual compression,
4777 * so we can guarantee to get this string
4778 * exactly the length we want it. The
4779 * compression-disabling routine should
4780 * return an integer indicating how many
4781 * bytes we should adjust our string length
4782 * by.
4783 */
4784 stringlen -= cscomp->disable_compression();
4785 }
1408a877 4786 ssh2_pkt_init(SSH2_MSG_IGNORE);
4787 ssh2_pkt_addstring_start();
6e9e9520 4788 for (i = 0; i < stringlen; i++) {
32874aea 4789 char c = (char) random_byte();
4790 ssh2_pkt_addstring_data(&c, 1);
65a22376 4791 }
1408a877 4792 ssh2_pkt_defer();
65a22376 4793 }
39065bed 4794 ssh_pkt_defersend();
0d43337a 4795 logevent("Sent password");
1408a877 4796 type = AUTH_TYPE_PASSWORD;
761187b6 4797 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
45068b27 4798 if (curr_prompt == 0) {
4799 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4800 ssh2_pkt_adduint32(num_prompts);
4801 }
4802 if (need_pw) { /* only add pw if we just got one! */
4803 ssh2_pkt_addstring(password);
4804 memset(password, 0, sizeof(password));
4805 curr_prompt++;
4806 }
4807 if (curr_prompt >= num_prompts) {
4808 ssh2_pkt_send();
4809 } else {
4810 /*
4811 * If there are prompts remaining, we set
4812 * `gotit' so that we won't attempt to get
4813 * another packet. Then we go back round the
4814 * loop and will end up retrieving another
4815 * prompt out of the existing packet. Funky or
4816 * what?
4817 */
4818 gotit = TRUE;
4819 }
761187b6 4820 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 4821 } else {
32874aea 4822 c_write_str
4823 ("No supported authentication methods left to try!\r\n");
4824 logevent
4825 ("No supported authentications offered. Disconnecting");
1408a877 4826 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4827 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
32874aea 4828 ssh2_pkt_addstring
4829 ("No supported authentication methods available");
4830 ssh2_pkt_addstring("en"); /* language tag */
1408a877 4831 ssh2_pkt_send();
4832 ssh_state = SSH_STATE_CLOSED;
4833 crReturnV;
65a22376 4834 }
65a22376 4835 }
1408a877 4836 } while (!we_are_in);
7cca0d81 4837
4838 /*
4839 * Now we're authenticated for the connection protocol. The
4840 * connection protocol will automatically have started at this
4841 * point; there's no need to send SERVICE_REQUEST.
4842 */
4843
4844 /*
4845 * So now create a channel with a session in it.
4846 */
d2371c81 4847 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 4848 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 4849 mainchan->localid = alloc_channel_id();
7cca0d81 4850 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4851 ssh2_pkt_addstring("session");
d211621f 4852 ssh2_pkt_adduint32(mainchan->localid);
5471d09a 4853 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4854 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
32874aea 4855 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 4856 ssh2_pkt_send();
4857 crWaitUntilV(ispkt);
4858 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 4859 bombout(("Server refused to open a session"));
4860 crReturnV;
4861 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 4862 }
d211621f 4863 if (ssh2_pkt_getuint32() != mainchan->localid) {
32874aea 4864 bombout(("Server's channel confirmation cited wrong channel"));
4865 crReturnV;
7cca0d81 4866 }
d211621f 4867 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 4868 mainchan->type = CHAN_MAINSESSION;
4869 mainchan->closes = 0;
5471d09a 4870 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4871 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4872 bufchain_init(&mainchan->v.v2.outbuffer);
783415f8 4873 add234(ssh_channels, mainchan);
7cca0d81 4874 logevent("Opened channel for session");
4875
4876 /*
783415f8 4877 * Potentially enable X11 forwarding.
4878 */
4879 if (cfg.x11_forward) {
32874aea 4880 char proto[20], data[64];
4881 logevent("Requesting X11 forwarding");
4882 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4883 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4884 ssh2_pkt_adduint32(mainchan->remoteid);
4885 ssh2_pkt_addstring("x11-req");
4886 ssh2_pkt_addbool(1); /* want reply */
4887 ssh2_pkt_addbool(0); /* many connections */
4888 ssh2_pkt_addstring(proto);
4889 ssh2_pkt_addstring(data);
4890 ssh2_pkt_adduint32(0); /* screen number */
4891 ssh2_pkt_send();
4892
4893 do {
4894 crWaitUntilV(ispkt);
4895 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4896 unsigned i = ssh2_pkt_getuint32();
4897 struct ssh_channel *c;
4898 c = find234(ssh_channels, &i, ssh_channelfind);
4899 if (!c)
4900 continue; /* nonexistent channel */
5471d09a 4901 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4902 }
4903 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4904
4905 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4906 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4907 bombout(("Unexpected response to X11 forwarding request:"
4908 " packet type %d", pktin.type));
32874aea 4909 crReturnV;
4910 }
4911 logevent("X11 forwarding refused");
4912 } else {
4913 logevent("X11 forwarding enabled");
783415f8 4914 ssh_X11_fwd_enabled = TRUE;
32874aea 4915 }
783415f8 4916 }
4917
4918 /*
bc240b21 4919 * Enable port forwardings.
4920 */
4921 {
4922 static char *e; /* preserve across crReturn */
4923 char type;
4924 int n;
a4fc0d74 4925 int sport,dport,sserv,dserv;
bc240b21 4926 char sports[256], dports[256], host[256];
4927 char buf[1024];
a4fc0d74 4928 struct servent *se;
bc240b21 4929
4930 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4931 /* Add port forwardings. */
4932 e = cfg.portfwd;
4933 while (*e) {
4934 type = *e++;
4935 n = 0;
4936 while (*e && *e != '\t')
4937 sports[n++] = *e++;
4938 sports[n] = 0;
4939 if (*e == '\t')
4940 e++;
4941 n = 0;
4942 while (*e && *e != ':')
4943 host[n++] = *e++;
4944 host[n] = 0;
4945 if (*e == ':')
4946 e++;
4947 n = 0;
4948 while (*e)
4949 dports[n++] = *e++;
4950 dports[n] = 0;
4951 e++;
4952 dport = atoi(dports);
a4fc0d74 4953 dserv = 0;
4954 if (dport == 0) {
4955 dserv = 1;
4956 se = getservbyname(dports, NULL);
4957 if (se != NULL) {
4958 dport = ntohs(se->s_port);
4959 } else {
4960 sprintf(buf,
4961 "Service lookup failed for destination port \"%s\"",
4962 dports);
4963 logevent(buf);
4964 }
4965 }
bc240b21 4966 sport = atoi(sports);
a4fc0d74 4967 sserv = 0;
4968 if (sport == 0) {
4969 sserv = 1;
4970 se = getservbyname(sports, NULL);
4971 if (se != NULL) {
4972 sport = ntohs(se->s_port);
4973 } else {
4974 sprintf(buf,
4975 "Service lookup failed for source port \"%s\"",
4976 sports);
4977 logevent(buf);
4978 }
4979 }
bc240b21 4980 if (sport && dport) {
4981 if (type == 'L') {
4982 pfd_addforward(host, dport, sport);
a4fc0d74 4983 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
4984 " %s:%.*s%.*s%d%.*s",
4985 sserv ? strlen(sports) : 0, sports,
4986 sserv, "(", sport, sserv, ")",
4987 host,
4988 dserv ? strlen(dports) : 0, dports,
4989 dserv, "(", dport, dserv, ")");
bc240b21 4990 logevent(buf);
4991 } else {
4992 struct ssh_rportfwd *pf;
4993 pf = smalloc(sizeof(*pf));
4994 strcpy(pf->dhost, host);
4995 pf->dport = dport;
4996 pf->sport = sport;
4997 if (add234(ssh_rportfwds, pf) != pf) {
4998 sprintf(buf,
95bc8819 4999 "Duplicate remote port forwarding to %s:%d",
bc240b21 5000 host, dport);
5001 logevent(buf);
5002 sfree(pf);
5003 } else {
a4fc0d74 5004 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5005 " forward to %s:%.*s%.*s%d%.*s",
5006 sserv ? strlen(sports) : 0, sports,
5007 sserv, "(", sport, sserv, ")",
5008 host,
5009 dserv ? strlen(dports) : 0, dports,
5010 dserv, "(", dport, dserv, ")");
bc240b21 5011 logevent(buf);
5012 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5013 ssh2_pkt_addstring("tcpip-forward");
5014 ssh2_pkt_addbool(1);/* want reply */
beefa433 5015 if (cfg.rport_acceptall)
5016 ssh2_pkt_addstring("0.0.0.0");
5017 else
5018 ssh2_pkt_addstring("127.0.0.1");
bc240b21 5019 ssh2_pkt_adduint32(sport);
5020 ssh2_pkt_send();
5021
5022 do {
5023 crWaitUntilV(ispkt);
5024 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5025 unsigned i = ssh2_pkt_getuint32();
5026 struct ssh_channel *c;
5027 c = find234(ssh_channels, &i, ssh_channelfind);
5028 if (!c)
5029 continue;/* nonexistent channel */
5471d09a 5030 c->v.v2.remwindow += ssh2_pkt_getuint32();
bc240b21 5031 }
5032 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5033
5034 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5035 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
c9886e66 5036 bombout(("Unexpected response to port "
5037 "forwarding request: packet type %d",
5038 pktin.type));
bc240b21 5039 crReturnV;
5040 }
5041 logevent("Server refused this port forwarding");
5042 } else {
5043 logevent("Remote port forwarding enabled");
5044 }
5045 }
5046 }
5047 }
5048 }
5049 }
5050
5051 /*
36c2a3e9 5052 * Potentially enable agent forwarding.
5053 */
5054 if (cfg.agentfwd && agent_exists()) {
32874aea 5055 logevent("Requesting OpenSSH-style agent forwarding");
5056 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5057 ssh2_pkt_adduint32(mainchan->remoteid);
5058 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5059 ssh2_pkt_addbool(1); /* want reply */
5060 ssh2_pkt_send();
5061
5062 do {
5063 crWaitUntilV(ispkt);
5064 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5065 unsigned i = ssh2_pkt_getuint32();
5066 struct ssh_channel *c;
5067 c = find234(ssh_channels, &i, ssh_channelfind);
5068 if (!c)
5069 continue; /* nonexistent channel */
5471d09a 5070 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5071 }
5072 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5073
5074 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5075 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5076 bombout(("Unexpected response to agent forwarding request:"
5077 " packet type %d", pktin.type));
32874aea 5078 crReturnV;
5079 }
5080 logevent("Agent forwarding refused");
5081 } else {
5082 logevent("Agent forwarding enabled");
36c2a3e9 5083 ssh_agentfwd_enabled = TRUE;
32874aea 5084 }
36c2a3e9 5085 }
5086
5087 /*
7cca0d81 5088 * Now allocate a pty for the session.
5089 */
67779be7 5090 if (!cfg.nopty) {
32874aea 5091 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5092 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5093 ssh2_pkt_addstring("pty-req");
5094 ssh2_pkt_addbool(1); /* want reply */
5095 ssh2_pkt_addstring(cfg.termtype);
5096 ssh2_pkt_adduint32(cols);
5097 ssh2_pkt_adduint32(rows);
5098 ssh2_pkt_adduint32(0); /* pixel width */
5099 ssh2_pkt_adduint32(0); /* pixel height */
5100 ssh2_pkt_addstring_start();
5101 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5102 ssh2_pkt_send();
5103 ssh_state = SSH_STATE_INTERMED;
5104
5105 do {
5106 crWaitUntilV(ispkt);
5107 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5108 unsigned i = ssh2_pkt_getuint32();
5109 struct ssh_channel *c;
5110 c = find234(ssh_channels, &i, ssh_channelfind);
5111 if (!c)
5112 continue; /* nonexistent channel */
5471d09a 5113 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5114 }
5115 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5116
5117 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5118 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5119 bombout(("Unexpected response to pty request:"
5120 " packet type %d", pktin.type));
32874aea 5121 crReturnV;
5122 }
5123 c_write_str("Server refused to allocate pty\r\n");
5124 ssh_editing = ssh_echoing = 1;
5125 } else {
5126 logevent("Allocated pty");
5127 }
0965bee0 5128 } else {
32874aea 5129 ssh_editing = ssh_echoing = 1;
7cca0d81 5130 }
5131
5132 /*
fd5e5847 5133 * Start a shell or a remote command. We may have to attempt
5134 * this twice if the config data has provided a second choice
5135 * of command.
7cca0d81 5136 */
fd5e5847 5137 while (1) {
5138 int subsys;
5139 char *cmd;
5140
5141 if (ssh_fallback_cmd) {
5142 subsys = cfg.ssh_subsys2;
5143 cmd = cfg.remote_cmd_ptr2;
5144 } else {
5145 subsys = cfg.ssh_subsys;
5146 cmd = cfg.remote_cmd_ptr;
5147 }
5148
5149 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5150 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5151 if (subsys) {
5152 ssh2_pkt_addstring("subsystem");
5153 ssh2_pkt_addbool(1); /* want reply */
5154 ssh2_pkt_addstring(cmd);
5155 } else if (*cmd) {
5156 ssh2_pkt_addstring("exec");
5157 ssh2_pkt_addbool(1); /* want reply */
5158 ssh2_pkt_addstring(cmd);
5159 } else {
5160 ssh2_pkt_addstring("shell");
5161 ssh2_pkt_addbool(1); /* want reply */
32874aea 5162 }
fd5e5847 5163 ssh2_pkt_send();
5164 do {
5165 crWaitUntilV(ispkt);
5166 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5167 unsigned i = ssh2_pkt_getuint32();
5168 struct ssh_channel *c;
5169 c = find234(ssh_channels, &i, ssh_channelfind);
5170 if (!c)
5171 continue; /* nonexistent channel */
5172 c->v.v2.remwindow += ssh2_pkt_getuint32();
5173 }
5174 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5175 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5176 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 5177 bombout(("Unexpected response to shell/command request:"
5178 " packet type %d", pktin.type));
fd5e5847 5179 crReturnV;
5180 }
5181 /*
5182 * We failed to start the command. If this is the
5183 * fallback command, we really are finished; if it's
5184 * not, and if the fallback command exists, try falling
5185 * back to it before complaining.
5186 */
5187 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5188 logevent("Primary command failed; attempting fallback");
5189 ssh_fallback_cmd = TRUE;
5190 continue;
5191 }
5192 bombout(("Server refused to start a shell/command"));
32874aea 5193 crReturnV;
fd5e5847 5194 } else {
5195 logevent("Started a shell/command");
32874aea 5196 }
fd5e5847 5197 break;
7cca0d81 5198 }
5199
6e48c3fe 5200 ssh_state = SSH_STATE_SESSION;
5201 if (size_needed)
5202 ssh_size();
3687d221 5203 if (eof_needed)
32874aea 5204 ssh_special(TS_EOF);
6e48c3fe 5205
7cca0d81 5206 /*
5207 * Transfer data!
5208 */
760e88b2 5209 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 5210 ssh_send_ok = 1;
7cca0d81 5211 while (1) {
32874aea 5212 static int try_send;
e5574168 5213 crReturnV;
32874aea 5214 try_send = FALSE;
7cca0d81 5215 if (ispkt) {
5216 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
32874aea 5217 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5218 char *data;
5219 int length;
5220 unsigned i = ssh2_pkt_getuint32();
5221 struct ssh_channel *c;
5222 c = find234(ssh_channels, &i, ssh_channelfind);
5223 if (!c)
5224 continue; /* nonexistent channel */
5225 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5226 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5227 continue; /* extended but not stderr */
5228 ssh2_pkt_getstring(&data, &length);
5229 if (data) {
5471d09a 5230 int bufsize;
5231 c->v.v2.locwindow -= length;
32874aea 5232 switch (c->type) {
5233 case CHAN_MAINSESSION:
5471d09a 5234 bufsize =
5235 from_backend(pktin.type ==
5236 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5237 data, length);
32874aea 5238 break;
5239 case CHAN_X11:
5471d09a 5240 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5241 break;
d74d141c 5242 case CHAN_SOCKDATA:
5471d09a 5243 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5244 break;
36c2a3e9 5245 case CHAN_AGENT:
32874aea 5246 while (length > 0) {
5247 if (c->u.a.lensofar < 4) {
5248 int l = min(4 - c->u.a.lensofar, length);
5249 memcpy(c->u.a.msglen + c->u.a.lensofar,
5250 data, l);
5251 data += l;
5252 length -= l;
5253 c->u.a.lensofar += l;
5254 }
5255 if (c->u.a.lensofar == 4) {
5256 c->u.a.totallen =
5257 4 + GET_32BIT(c->u.a.msglen);
5258 c->u.a.message = smalloc(c->u.a.totallen);
5259 memcpy(c->u.a.message, c->u.a.msglen, 4);
5260 }
5261 if (c->u.a.lensofar >= 4 && length > 0) {
5262 int l =
5263 min(c->u.a.totallen - c->u.a.lensofar,
5264 length);
5265 memcpy(c->u.a.message + c->u.a.lensofar,
5266 data, l);
5267 data += l;
5268 length -= l;
5269 c->u.a.lensofar += l;
5270 }
5271 if (c->u.a.lensofar == c->u.a.totallen) {
5272 void *reply, *sentreply;
5273 int replylen;
5274 agent_query(c->u.a.message,
5275 c->u.a.totallen, &reply,
5276 &replylen);
5277 if (reply)
5278 sentreply = reply;
5279 else {
5280 /* Fake SSH_AGENT_FAILURE. */
5281 sentreply = "\0\0\0\1\5";
5282 replylen = 5;
5283 }
5284 ssh2_add_channel_data(c, sentreply,
5285 replylen);
36c2a3e9 5286 try_send = TRUE;
32874aea 5287 if (reply)
5288 sfree(reply);
5289 sfree(c->u.a.message);
5290 c->u.a.lensofar = 0;
5291 }
5292 }
5471d09a 5293 bufsize = 0;
32874aea 5294 break;
5295 }
5296 /*
5471d09a 5297 * If we are not buffering too much data,
5298 * enlarge the window again at the remote side.
32874aea 5299 */
5471d09a 5300 if (bufsize < OUR_V2_WINSIZE)
5301 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5302 }
7cca0d81 5303 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
32874aea 5304 ssh_state = SSH_STATE_CLOSED;
d211621f 5305 logevent("Received disconnect message");
32874aea 5306 crReturnV;
d211621f 5307 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
32874aea 5308 unsigned i = ssh2_pkt_getuint32();
5309 struct ssh_channel *c;
5310
5311 c = find234(ssh_channels, &i, ssh_channelfind);
5312 if (!c)
5313 continue; /* nonexistent channel */
5314
5315 if (c->type == CHAN_X11) {
5316 /*
5317 * Remote EOF on an X11 channel means we should
5318 * wrap up and close the channel ourselves.
5319 */
5320 x11_close(c->u.x11.s);
5321 sshfwd_close(c);
5322 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5323 sshfwd_close(c);
d74d141c 5324 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5325 pfd_close(c->u.pfd.s);
5326 sshfwd_close(c);
36c2a3e9 5327 }
d211621f 5328 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
32874aea 5329 unsigned i = ssh2_pkt_getuint32();
5330 struct ssh_channel *c;
5331
5332 c = find234(ssh_channels, &i, ssh_channelfind);
5333 if (!c)
5334 continue; /* nonexistent channel */
32874aea 5335 /* Do pre-close processing on the channel. */
5336 switch (c->type) {
5337 case CHAN_MAINSESSION:
5338 break; /* nothing to see here, move along */
5339 case CHAN_X11:
92f157bd 5340 if (c->u.x11.s != NULL)
5341 x11_close(c->u.x11.s);
5342 sshfwd_close(c);
32874aea 5343 break;
5344 case CHAN_AGENT:
92f157bd 5345 sshfwd_close(c);
32874aea 5346 break;
d74d141c 5347 case CHAN_SOCKDATA:
92f157bd 5348 if (c->u.pfd.s != NULL)
5349 pfd_close(c->u.pfd.s);
5350 sshfwd_close(c);
bc240b21 5351 break;
32874aea 5352 }
92f157bd 5353 if (c->closes == 0) {
5354 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5355 ssh2_pkt_adduint32(c->remoteid);
5356 ssh2_pkt_send();
5357 }
32874aea 5358 del234(ssh_channels, c);
5471d09a 5359 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5360 sfree(c);
5361
5362 /*
5363 * See if that was the last channel left open.
5364 */
5365 if (count234(ssh_channels) == 0) {
ca2914d1 5366#if 0
5367 /*
5368 * We used to send SSH_MSG_DISCONNECT here,
5369 * because I'd believed that _every_ conforming
5370 * SSH2 connection had to end with a disconnect
5371 * being sent by at least one side; apparently
5372 * I was wrong and it's perfectly OK to
5373 * unceremoniously slam the connection shut
5374 * when you're done, and indeed OpenSSH feels
5375 * this is more polite than sending a
5376 * DISCONNECT. So now we don't.
5377 */
32874aea 5378 logevent("All channels closed. Disconnecting");
5379 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5380 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5381 ssh2_pkt_addstring("All open channels closed");
5382 ssh2_pkt_addstring("en"); /* language tag */
5383 ssh2_pkt_send();
ca2914d1 5384#endif
32874aea 5385 ssh_state = SSH_STATE_CLOSED;
5386 crReturnV;
5387 }
5388 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 5389 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
32874aea 5390 unsigned i = ssh2_pkt_getuint32();
5391 struct ssh_channel *c;
5392 c = find234(ssh_channels, &i, ssh_channelfind);
5393 if (!c)
5394 continue; /* nonexistent channel */
5471d09a 5395 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 5396 try_send = TRUE;
bc240b21 5397 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5398 unsigned i = ssh2_pkt_getuint32();
5399 struct ssh_channel *c;
5400 c = find234(ssh_channels, &i, ssh_channelfind);
5401 if (!c)
5402 continue; /* nonexistent channel */
5403 if (c->type != CHAN_SOCKDATA_DORMANT)
5404 continue; /* dunno why they're confirming this */
5405 c->remoteid = ssh2_pkt_getuint32();
5406 c->type = CHAN_SOCKDATA;
5471d09a 5407 c->v.v2.remwindow = ssh2_pkt_getuint32();
5408 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4ed34d25 5409 if (c->u.pfd.s)
5410 pfd_confirm(c->u.pfd.s);
5411 if (c->closes) {
5412 /*
5413 * We have a pending close on this channel,
5414 * which we decided on before the server acked
5415 * the channel open. So now we know the
5416 * remoteid, we can close it again.
5417 */
5418 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5419 ssh2_pkt_adduint32(c->remoteid);
5420 ssh2_pkt_send();
5421 }
724cface 5422 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5423 unsigned i = ssh2_pkt_getuint32();
5424 struct ssh_channel *c;
5425 c = find234(ssh_channels, &i, ssh_channelfind);
5426 if (!c)
5427 continue; /* nonexistent channel */
5428 if (c->type != CHAN_SOCKDATA_DORMANT)
5429 continue; /* dunno why they're failing this */
5430
5431 logevent("Forwarded connection refused by server");
5432
5433 pfd_close(c->u.pfd.s);
5434
5435 del234(ssh_channels, c);
5436 sfree(c);
ebb0a590 5437 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5438 unsigned localid;
5439 char *type;
5440 int typelen, want_reply;
5441 struct ssh_channel *c;
5442
5443 localid = ssh2_pkt_getuint32();
5444 ssh2_pkt_getstring(&type, &typelen);
5445 want_reply = ssh2_pkt_getbool();
5446
5447 /*
5448 * First, check that the channel exists. Otherwise,
5449 * we can instantly disconnect with a rude message.
5450 */
5451 c = find234(ssh_channels, &localid, ssh_channelfind);
5452 if (!c) {
5453 char buf[80];
5454 sprintf(buf, "Received channel request for nonexistent"
5455 " channel %d", localid);
5456 logevent(buf);
5457 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5458 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5459 ssh2_pkt_addstring(buf);
5460 ssh2_pkt_addstring("en"); /* language tag */
5461 ssh2_pkt_send();
247308b5 5462 connection_fatal("%s", buf);
ebb0a590 5463 ssh_state = SSH_STATE_CLOSED;
5464 crReturnV;
5465 }
5466
5467 /*
d8d6c7e5 5468 * Having got the channel number, we now look at
5469 * the request type string to see if it's something
5470 * we recognise.
ebb0a590 5471 */
d8d6c7e5 5472 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5473 c == mainchan) {
5474 /* We recognise "exit-status" on the primary channel. */
5475 char buf[100];
5476 ssh_exitcode = ssh2_pkt_getuint32();
5477 sprintf(buf, "Server sent command exit status %d",
5478 ssh_exitcode);
5479 logevent(buf);
5480 if (want_reply) {
5481 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5482 ssh2_pkt_adduint32(c->remoteid);
5483 ssh2_pkt_send();
5484 }
5485 } else {
5486 /*
5487 * This is a channel request we don't know
5488 * about, so we now either ignore the request
5489 * or respond with CHANNEL_FAILURE, depending
5490 * on want_reply.
5491 */
5492 if (want_reply) {
5493 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5494 ssh2_pkt_adduint32(c->remoteid);
5495 ssh2_pkt_send();
5496 }
ebb0a590 5497 }
697d4856 5498 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5499 char *type;
5500 int typelen, want_reply;
5501
5502 ssh2_pkt_getstring(&type, &typelen);
5503 want_reply = ssh2_pkt_getbool();
5504
5505 /*
5506 * We currently don't support any global requests
5507 * at all, so we either ignore the request or
5508 * respond with REQUEST_FAILURE, depending on
5509 * want_reply.
5510 */
5511 if (want_reply) {
5512 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5513 ssh2_pkt_send();
5514 }
783415f8 5515 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5516 char *type;
5517 int typelen;
5518 char *error = NULL;
5519 struct ssh_channel *c;
bc240b21 5520 unsigned remid, winsize, pktsize;
32874aea 5521 ssh2_pkt_getstring(&type, &typelen);
5522 c = smalloc(sizeof(struct ssh_channel));
5523
bc240b21 5524 remid = ssh2_pkt_getuint32();
5525 winsize = ssh2_pkt_getuint32();
5526 pktsize = ssh2_pkt_getuint32();
5527
32874aea 5528 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5529 if (!ssh_X11_fwd_enabled)
5530 error = "X11 forwarding is not enabled";
5531 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5532 NULL) {
5533 error = "Unable to open an X11 connection";
5534 } else {
5535 c->type = CHAN_X11;
5536 }
bc240b21 5537 } else if (typelen == 15 &&
5538 !memcmp(type, "forwarded-tcpip", 15)) {
5539 struct ssh_rportfwd pf, *realpf;
5540 char *dummy;
5541 int dummylen;
5542 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5543 pf.sport = ssh2_pkt_getuint32();
5544 realpf = find234(ssh_rportfwds, &pf, NULL);
5545 if (realpf == NULL) {
5546 error = "Remote port is not recognised";
5547 } else {
5548 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5549 realpf->dport, c);
5550 char buf[1024];
5551 sprintf(buf, "Received remote port open request for %s:%d",
5552 realpf->dhost, realpf->dport);
5553 logevent(buf);
5554 if (e != NULL) {
5555 sprintf(buf, "Port open failed: %s", e);
5556 logevent(buf);
5557 error = "Port open failed";
5558 } else {
5559 logevent("Forwarded port opened successfully");
5560 c->type = CHAN_SOCKDATA;
5561 }
5562 }
32874aea 5563 } else if (typelen == 22 &&
36c2a3e9 5564 !memcmp(type, "auth-agent@openssh.com", 3)) {
32874aea 5565 if (!ssh_agentfwd_enabled)
5566 error = "Agent forwarding is not enabled";
36c2a3e9 5567 else {
32874aea 5568 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5569 c->u.a.lensofar = 0;
32874aea 5570 }
5571 } else {
5572 error = "Unsupported channel type requested";
5573 }
5574
bc240b21 5575 c->remoteid = remid;
32874aea 5576 if (error) {
5577 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5578 ssh2_pkt_adduint32(c->remoteid);
5579 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5580 ssh2_pkt_addstring(error);
5581 ssh2_pkt_addstring("en"); /* language tag */
5582 ssh2_pkt_send();
5583 sfree(c);
5584 } else {
5585 c->localid = alloc_channel_id();
5586 c->closes = 0;
5471d09a 5587 c->v.v2.locwindow = OUR_V2_WINSIZE;
5588 c->v.v2.remwindow = winsize;
5589 c->v.v2.remmaxpkt = pktsize;
5590 bufchain_init(&c->v.v2.outbuffer);
32874aea 5591 add234(ssh_channels, c);
5592 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5593 ssh2_pkt_adduint32(c->remoteid);
5594 ssh2_pkt_adduint32(c->localid);
5471d09a 5595 ssh2_pkt_adduint32(c->v.v2.locwindow);
32874aea 5596 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5597 ssh2_pkt_send();
5598 }
7cca0d81 5599 } else {
8d5de777 5600 bombout(("Strange packet received: type %d", pktin.type));
32874aea 5601 crReturnV;
7cca0d81 5602 }
5603 } else {
32874aea 5604 /*
5605 * We have spare data. Add it to the channel buffer.
5606 */
5607 ssh2_add_channel_data(mainchan, in, inlen);
5608 try_send = TRUE;
5609 }
5610 if (try_send) {
5611 int i;
5612 struct ssh_channel *c;
5613 /*
5614 * Try to send data on all channels if we can.
5615 */
5471d09a 5616 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5617 int bufsize = ssh2_try_send(c);
5618 if (bufsize == 0) {
5619 switch (c->type) {
5620 case CHAN_MAINSESSION:
5621 /* stdin need not receive an unthrottle
5622 * notification since it will be polled */
5623 break;
5624 case CHAN_X11:
5625 x11_unthrottle(c->u.x11.s);
5626 break;
5627 case CHAN_AGENT:
5628 /* agent sockets are request/response and need no
5629 * buffer management */
5630 break;
5631 case CHAN_SOCKDATA:
5632 pfd_unthrottle(c->u.pfd.s);
5633 break;
5634 }
5635 }
5636 }
7cca0d81 5637 }
e5574168 5638 }
5639
5640 crFinishV;
5641}
5642
5643/*
7cca0d81 5644 * Handle the top-level SSH2 protocol.
5645 */
5646static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5647{
5648 if (do_ssh2_transport(in, inlen, ispkt) == 0)
32874aea 5649 return;
7cca0d81 5650 do_ssh2_authconn(in, inlen, ispkt);
5651}
5652
5653/*
8df7a775 5654 * Called to set up the connection.
374330e2 5655 *
5656 * Returns an error message, or NULL on success.
374330e2 5657 */
2184a5d9 5658static char *ssh_init(char *host, int port, char **realhost, int nodelay)
32874aea 5659{
fb09bf1c 5660 char *p;
32874aea 5661
8f203108 5662#ifdef MSCRYPTOAPI
32874aea 5663 if (crypto_startup() == 0)
8f203108 5664 return "Microsoft high encryption pack not installed!";
5665#endif
374330e2 5666
8df7a775 5667 ssh_send_ok = 0;
0965bee0 5668 ssh_editing = 0;
5669 ssh_echoing = 0;
5471d09a 5670 ssh1_throttle_count = 0;
5671 ssh_overall_bufsize = 0;
fd5e5847 5672 ssh_fallback_cmd = 0;
8df7a775 5673
2184a5d9 5674 p = connect_to_host(host, port, realhost, nodelay);
fb09bf1c 5675 if (p != NULL)
5676 return p;
374330e2 5677
374330e2 5678 return NULL;
5679}
5680
5681/*
374330e2 5682 * Called to send data down the Telnet connection.
5683 */
5471d09a 5684static int ssh_send(char *buf, int len)
32874aea 5685{
f78051a1 5686 if (s == NULL || ssh_protocol == NULL)
5471d09a 5687 return 0;
374330e2 5688
5689 ssh_protocol(buf, len, 0);
5471d09a 5690
5691 return ssh_sendbuffer();
5692}
5693
5694/*
5695 * Called to query the current amount of buffered stdin data.
5696 */
5697static int ssh_sendbuffer(void)
5698{
5699 int override_value;
5700
5701 if (s == NULL || ssh_protocol == NULL)
5702 return 0;
5703
5704 /*
5705 * If the SSH socket itself has backed up, add the total backup
5706 * size on that to any individual buffer on the stdin channel.
5707 */
5708 override_value = 0;
5709 if (ssh_throttled_all)
5710 override_value = ssh_overall_bufsize;
5711
5712 if (ssh_version == 1) {
5713 return override_value;
5714 } else if (ssh_version == 2) {
5715 if (!mainchan || mainchan->closes > 0)
5716 return override_value;
5717 else
5718 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5719 }
5720
5721 return 0;
374330e2 5722}
5723
5724/*
6e48c3fe 5725 * Called to set the size of the window from SSH's POV.
374330e2 5726 */
32874aea 5727static void ssh_size(void)
5728{
374330e2 5729 switch (ssh_state) {
5730 case SSH_STATE_BEFORE_SIZE:
3687d221 5731 case SSH_STATE_PREPACKET:
21248260 5732 case SSH_STATE_CLOSED:
374330e2 5733 break; /* do nothing */
5734 case SSH_STATE_INTERMED:
5735 size_needed = TRUE; /* buffer for later */
5736 break;
5737 case SSH_STATE_SESSION:
32874aea 5738 if (!cfg.nopty) {
5739 if (ssh_version == 1) {
5740 send_packet(SSH1_CMSG_WINDOW_SIZE,
5741 PKT_INT, rows, PKT_INT, cols,
5742 PKT_INT, 0, PKT_INT, 0, PKT_END);
5743 } else {
5744 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5745 ssh2_pkt_adduint32(mainchan->remoteid);
5746 ssh2_pkt_addstring("window-change");
5747 ssh2_pkt_addbool(0);
5748 ssh2_pkt_adduint32(cols);
5749 ssh2_pkt_adduint32(rows);
5750 ssh2_pkt_adduint32(0);
5751 ssh2_pkt_adduint32(0);
5752 ssh2_pkt_send();
5753 }
5754 }
5755 break;
374330e2 5756 }
5757}
5758
5759/*
6abbf9e3 5760 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5761 * can send an EOF and collect resulting output (e.g. `plink
5762 * hostname sort').
374330e2 5763 */
32874aea 5764static void ssh_special(Telnet_Special code)
5765{
6abbf9e3 5766 if (code == TS_EOF) {
32874aea 5767 if (ssh_state != SSH_STATE_SESSION) {
5768 /*
5769 * Buffer the EOF in case we are pre-SESSION, so we can
5770 * send it as soon as we reach SESSION.
5771 */
5772 if (code == TS_EOF)
5773 eof_needed = TRUE;
5774 return;
5775 }
5776 if (ssh_version == 1) {
5777 send_packet(SSH1_CMSG_EOF, PKT_END);
5778 } else {
5779 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5780 ssh2_pkt_adduint32(mainchan->remoteid);
5781 ssh2_pkt_send();
5782 }
5783 logevent("Sent EOF message");
ec55b220 5784 } else if (code == TS_PING) {
32874aea 5785 if (ssh_state == SSH_STATE_CLOSED
5786 || ssh_state == SSH_STATE_PREPACKET) return;
5787 if (ssh_version == 1) {
5788 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5789 } else {
5790 ssh2_pkt_init(SSH2_MSG_IGNORE);
5791 ssh2_pkt_addstring_start();
5792 ssh2_pkt_send();
5793 }
6abbf9e3 5794 } else {
32874aea 5795 /* do nothing */
6abbf9e3 5796 }
374330e2 5797}
5798
d74d141c 5799void *new_sock_channel(Socket s)
5800{
5801 struct ssh_channel *c;
5802 c = smalloc(sizeof(struct ssh_channel));
5803
5804 if (c) {
bc240b21 5805 c->remoteid = -1; /* to be set when open confirmed */
d74d141c 5806 c->localid = alloc_channel_id();
5807 c->closes = 0;
bc240b21 5808 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 5809 c->u.pfd.s = s;
013dd8c0 5810 bufchain_init(&c->v.v2.outbuffer);
d74d141c 5811 add234(ssh_channels, c);
5812 }
5813 return c;
5814}
5815
5471d09a 5816/*
5817 * This is called when stdout/stderr (the entity to which
5818 * from_backend sends data) manages to clear some backlog.
5819 */
5820void ssh_unthrottle(int bufsize)
5821{
5822 if (ssh_version == 1) {
90347b95 5823 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5471d09a 5824 ssh1_stdout_throttling = 0;
5825 ssh1_throttle(-1);
5826 }
5827 } else {
5828 if (mainchan && mainchan->closes == 0)
5829 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5830 }
5831}
5832
d74d141c 5833void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5834{
5835 struct ssh_channel *c = (struct ssh_channel *)channel;
5836 char buf[1024];
5837
5838 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5839 logevent(buf);
5840
bc240b21 5841 if (ssh_version == 1) {
5842 send_packet(SSH1_MSG_PORT_OPEN,
5843 PKT_INT, c->localid,
5844 PKT_STR, hostname,
5845 PKT_INT, port,
5846 //PKT_STR, <org:orgport>,
5847 PKT_END);
5848 } else {
5849 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5850 ssh2_pkt_addstring("direct-tcpip");
5851 ssh2_pkt_adduint32(c->localid);
5471d09a 5852 c->v.v2.locwindow = OUR_V2_WINSIZE;
5853 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
bc240b21 5854 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5855 ssh2_pkt_addstring(hostname);
5856 ssh2_pkt_adduint32(port);
5857 /*
5858 * We make up values for the originator data; partly it's
5859 * too much hassle to keep track, and partly I'm not
5860 * convinced the server should be told details like that
5861 * about my local network configuration.
5862 */
5863 ssh2_pkt_addstring("client-side-connection");
5864 ssh2_pkt_adduint32(0);
5865 ssh2_pkt_send();
5866 }
d74d141c 5867}
5868
5869
32874aea 5870static Socket ssh_socket(void)
5871{
5872 return s;
5873}
8ccc75b0 5874
32874aea 5875static int ssh_sendok(void)
5876{
5877 return ssh_send_ok;
5878}
fb09bf1c 5879
32874aea 5880static int ssh_ldisc(int option)
5881{
5882 if (option == LD_ECHO)
5883 return ssh_echoing;
5884 if (option == LD_EDIT)
5885 return ssh_editing;
0965bee0 5886 return FALSE;
5887}
5888
d8d6c7e5 5889static int ssh_return_exitcode(void)
5890{
5891 return ssh_exitcode;
5892}
5893
374330e2 5894Backend ssh_backend = {
5895 ssh_init,
374330e2 5896 ssh_send,
5471d09a 5897 ssh_sendbuffer,
374330e2 5898 ssh_size,
4017be6d 5899 ssh_special,
8ccc75b0 5900 ssh_socket,
d8d6c7e5 5901 ssh_return_exitcode,
97db3be4 5902 ssh_sendok,
0965bee0 5903 ssh_ldisc,
5471d09a 5904 ssh_unthrottle,
97db3be4 5905 22
bc240b21 5906};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator