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Don't close SSH-2 channels with outstanding channel requests on local error.
[u/mdw/putty] / ssh.c
CommitLineData
eaf1e20a 1/*
2 * SSH backend.
3 */
4
374330e2 5#include <stdio.h>
6#include <stdlib.h>
fb09bf1c 7#include <stdarg.h>
8#include <assert.h>
3c112d53 9#include <limits.h>
d051d1b4 10#include <signal.h>
374330e2 11
12#include "putty.h"
dacbd0e8 13#include "tree234.h"
fb09bf1c 14#include "ssh.h"
bf84a03a 15#ifndef NO_GSSAPI
b3d375b2 16#include "sshgssc.h"
42af6a67 17#include "sshgss.h"
bf84a03a 18#endif
374330e2 19
20#ifndef FALSE
21#define FALSE 0
22#endif
23#ifndef TRUE
24#define TRUE 1
25#endif
26
32874aea 27#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
28#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
29#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
30#define SSH1_CMSG_USER 4 /* 0x4 */
31#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
32#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
33#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
34#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
35#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
36#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
37#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
38#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
39#define SSH1_SMSG_SUCCESS 14 /* 0xe */
40#define SSH1_SMSG_FAILURE 15 /* 0xf */
41#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
42#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
43#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
44#define SSH1_CMSG_EOF 19 /* 0x13 */
45#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
46#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
47#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
48#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
49#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
50#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
51#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
52#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
53#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
54#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
55#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
56#define SSH1_MSG_IGNORE 32 /* 0x20 */
57#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
58#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
59#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
60#define SSH1_MSG_DEBUG 36 /* 0x24 */
61#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
62#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
63#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
64#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
65#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
66#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
67#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
68
8f9e3231 69#define SSH1_AUTH_RHOSTS 1 /* 0x1 */
70#define SSH1_AUTH_RSA 2 /* 0x2 */
71#define SSH1_AUTH_PASSWORD 3 /* 0x3 */
72#define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */
32874aea 73#define SSH1_AUTH_TIS 5 /* 0x5 */
74#define SSH1_AUTH_CCARD 16 /* 0x10 */
75
76#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 77/* Mask for protoflags we will echo back to server if seen */
32874aea 78#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
79
80#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
81#define SSH2_MSG_IGNORE 2 /* 0x2 */
82#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
83#define SSH2_MSG_DEBUG 4 /* 0x4 */
84#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
85#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
86#define SSH2_MSG_KEXINIT 20 /* 0x14 */
87#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
88#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
89#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
90#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
91#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
92#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
93#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
fae1a71b 94#define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */
95#define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */
96#define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */
32874aea 97#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
98#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
99#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
100#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
101#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
102#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 103#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
104#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 105#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
106#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
107#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
108#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
109#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
110#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
111#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
112#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
113#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
114#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
115#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
116#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
117#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
118#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
42af6a67 119#define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60
120#define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61
121#define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63
122#define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64
123#define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65
124#define SSH2_MSG_USERAUTH_GSSAPI_MIC 66
32874aea 125
00db133f 126/*
127 * Packet type contexts, so that ssh2_pkt_type can correctly decode
128 * the ambiguous type numbers back into the correct type strings.
129 */
acab36bc 130typedef enum {
131 SSH2_PKTCTX_NOKEX,
132 SSH2_PKTCTX_DHGROUP,
133 SSH2_PKTCTX_DHGEX,
134 SSH2_PKTCTX_RSAKEX
135} Pkt_KCtx;
136typedef enum {
137 SSH2_PKTCTX_NOAUTH,
138 SSH2_PKTCTX_PUBLICKEY,
139 SSH2_PKTCTX_PASSWORD,
42af6a67 140 SSH2_PKTCTX_GSSAPI,
acab36bc 141 SSH2_PKTCTX_KBDINTER
142} Pkt_ACtx;
00db133f 143
32874aea 144#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
145#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
146#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
147#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
148#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
149#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
150#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
151#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
152#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
153#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
154#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
155#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
156#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
157#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
158#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 159
160static const char *const ssh2_disconnect_reasons[] = {
161 NULL,
afb4d0dc 162 "host not allowed to connect",
163 "protocol error",
164 "key exchange failed",
165 "host authentication failed",
1da38d29 166 "MAC error",
afb4d0dc 167 "compression error",
168 "service not available",
169 "protocol version not supported",
170 "host key not verifiable",
171 "connection lost",
172 "by application",
173 "too many connections",
174 "auth cancelled by user",
175 "no more auth methods available",
176 "illegal user name",
38c4a8da 177};
9005f3ba 178
32874aea 179#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
180#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
181#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
182#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 183
32874aea 184#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 185
7d503c31 186/*
187 * Various remote-bug flags.
188 */
189#define BUG_CHOKES_ON_SSH1_IGNORE 1
190#define BUG_SSH2_HMAC 2
bd358db1 191#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 192#define BUG_CHOKES_ON_RSA 8
1dd353b5 193#define BUG_SSH2_RSA_PADDING 16
088bde77 194#define BUG_SSH2_DERIVEKEY 32
f382c87d 195#define BUG_SSH2_REKEY 64
dda87a28 196#define BUG_SSH2_PK_SESSIONID 128
c9739dba 197#define BUG_SSH2_MAXPKT 256
cf6ddb95 198#define BUG_CHOKES_ON_SSH2_IGNORE 512
2e0aae4f 199#define BUG_CHOKES_ON_WINADJ 1024
bd358db1 200
c6ccd5c2 201/*
202 * Codes for terminal modes.
203 * Most of these are the same in SSH-1 and SSH-2.
7646c432 204 * This list is derived from RFC 4254 and
c6ccd5c2 205 * SSH-1 RFC-1.2.31.
206 */
207static const struct {
208 const char* const mode;
209 int opcode;
210 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
211} ssh_ttymodes[] = {
212 /* "V" prefix discarded for special characters relative to SSH specs */
213 { "INTR", 1, TTY_OP_CHAR },
214 { "QUIT", 2, TTY_OP_CHAR },
215 { "ERASE", 3, TTY_OP_CHAR },
216 { "KILL", 4, TTY_OP_CHAR },
217 { "EOF", 5, TTY_OP_CHAR },
218 { "EOL", 6, TTY_OP_CHAR },
219 { "EOL2", 7, TTY_OP_CHAR },
220 { "START", 8, TTY_OP_CHAR },
221 { "STOP", 9, TTY_OP_CHAR },
222 { "SUSP", 10, TTY_OP_CHAR },
223 { "DSUSP", 11, TTY_OP_CHAR },
224 { "REPRINT", 12, TTY_OP_CHAR },
225 { "WERASE", 13, TTY_OP_CHAR },
226 { "LNEXT", 14, TTY_OP_CHAR },
227 { "FLUSH", 15, TTY_OP_CHAR },
228 { "SWTCH", 16, TTY_OP_CHAR },
229 { "STATUS", 17, TTY_OP_CHAR },
230 { "DISCARD", 18, TTY_OP_CHAR },
231 { "IGNPAR", 30, TTY_OP_BOOL },
232 { "PARMRK", 31, TTY_OP_BOOL },
233 { "INPCK", 32, TTY_OP_BOOL },
234 { "ISTRIP", 33, TTY_OP_BOOL },
235 { "INLCR", 34, TTY_OP_BOOL },
236 { "IGNCR", 35, TTY_OP_BOOL },
237 { "ICRNL", 36, TTY_OP_BOOL },
238 { "IUCLC", 37, TTY_OP_BOOL },
239 { "IXON", 38, TTY_OP_BOOL },
240 { "IXANY", 39, TTY_OP_BOOL },
241 { "IXOFF", 40, TTY_OP_BOOL },
242 { "IMAXBEL", 41, TTY_OP_BOOL },
243 { "ISIG", 50, TTY_OP_BOOL },
244 { "ICANON", 51, TTY_OP_BOOL },
245 { "XCASE", 52, TTY_OP_BOOL },
246 { "ECHO", 53, TTY_OP_BOOL },
247 { "ECHOE", 54, TTY_OP_BOOL },
248 { "ECHOK", 55, TTY_OP_BOOL },
249 { "ECHONL", 56, TTY_OP_BOOL },
250 { "NOFLSH", 57, TTY_OP_BOOL },
251 { "TOSTOP", 58, TTY_OP_BOOL },
252 { "IEXTEN", 59, TTY_OP_BOOL },
253 { "ECHOCTL", 60, TTY_OP_BOOL },
254 { "ECHOKE", 61, TTY_OP_BOOL },
255 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
256 { "OPOST", 70, TTY_OP_BOOL },
257 { "OLCUC", 71, TTY_OP_BOOL },
258 { "ONLCR", 72, TTY_OP_BOOL },
259 { "OCRNL", 73, TTY_OP_BOOL },
260 { "ONOCR", 74, TTY_OP_BOOL },
261 { "ONLRET", 75, TTY_OP_BOOL },
262 { "CS7", 90, TTY_OP_BOOL },
263 { "CS8", 91, TTY_OP_BOOL },
264 { "PARENB", 92, TTY_OP_BOOL },
265 { "PARODD", 93, TTY_OP_BOOL }
266};
267
268/* Miscellaneous other tty-related constants. */
269#define SSH_TTY_OP_END 0
270/* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
271#define SSH1_TTY_OP_ISPEED 192
272#define SSH1_TTY_OP_OSPEED 193
273#define SSH2_TTY_OP_ISPEED 128
274#define SSH2_TTY_OP_OSPEED 129
275
276/* Helper functions for parsing tty-related config. */
277static unsigned int ssh_tty_parse_specchar(char *s)
278{
279 unsigned int ret;
280 if (*s) {
281 char *next = NULL;
282 ret = ctrlparse(s, &next);
283 if (!next) ret = s[0];
284 } else {
285 ret = 255; /* special value meaning "don't set" */
286 }
287 return ret;
288}
289static unsigned int ssh_tty_parse_boolean(char *s)
290{
291 if (stricmp(s, "yes") == 0 ||
292 stricmp(s, "on") == 0 ||
293 stricmp(s, "true") == 0 ||
294 stricmp(s, "+") == 0)
295 return 1; /* true */
296 else if (stricmp(s, "no") == 0 ||
297 stricmp(s, "off") == 0 ||
298 stricmp(s, "false") == 0 ||
299 stricmp(s, "-") == 0)
300 return 0; /* false */
301 else
302 return (atoi(s) != 0);
303}
304
00db133f 305#define translate(x) if (type == x) return #x
acab36bc 306#define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
307#define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
ae9ae89f 308static char *ssh1_pkt_type(int type)
00db133f 309{
310 translate(SSH1_MSG_DISCONNECT);
311 translate(SSH1_SMSG_PUBLIC_KEY);
312 translate(SSH1_CMSG_SESSION_KEY);
313 translate(SSH1_CMSG_USER);
314 translate(SSH1_CMSG_AUTH_RSA);
315 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
316 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
317 translate(SSH1_CMSG_AUTH_PASSWORD);
318 translate(SSH1_CMSG_REQUEST_PTY);
319 translate(SSH1_CMSG_WINDOW_SIZE);
320 translate(SSH1_CMSG_EXEC_SHELL);
321 translate(SSH1_CMSG_EXEC_CMD);
322 translate(SSH1_SMSG_SUCCESS);
323 translate(SSH1_SMSG_FAILURE);
324 translate(SSH1_CMSG_STDIN_DATA);
325 translate(SSH1_SMSG_STDOUT_DATA);
326 translate(SSH1_SMSG_STDERR_DATA);
327 translate(SSH1_CMSG_EOF);
328 translate(SSH1_SMSG_EXIT_STATUS);
329 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
330 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
331 translate(SSH1_MSG_CHANNEL_DATA);
332 translate(SSH1_MSG_CHANNEL_CLOSE);
333 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
334 translate(SSH1_SMSG_X11_OPEN);
335 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
336 translate(SSH1_MSG_PORT_OPEN);
337 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
338 translate(SSH1_SMSG_AGENT_OPEN);
339 translate(SSH1_MSG_IGNORE);
340 translate(SSH1_CMSG_EXIT_CONFIRMATION);
341 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
342 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
343 translate(SSH1_MSG_DEBUG);
344 translate(SSH1_CMSG_REQUEST_COMPRESSION);
345 translate(SSH1_CMSG_AUTH_TIS);
346 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
347 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
348 translate(SSH1_CMSG_AUTH_CCARD);
349 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
350 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
351 return "unknown";
352}
acab36bc 353static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
00db133f 354{
42af6a67 355 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
356 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
357 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
358 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
359 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
360 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
00db133f 361 translate(SSH2_MSG_DISCONNECT);
362 translate(SSH2_MSG_IGNORE);
363 translate(SSH2_MSG_UNIMPLEMENTED);
364 translate(SSH2_MSG_DEBUG);
365 translate(SSH2_MSG_SERVICE_REQUEST);
366 translate(SSH2_MSG_SERVICE_ACCEPT);
367 translate(SSH2_MSG_KEXINIT);
368 translate(SSH2_MSG_NEWKEYS);
acab36bc 369 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
370 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
371 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
372 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
373 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
374 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
375 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
376 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
377 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
00db133f 378 translate(SSH2_MSG_USERAUTH_REQUEST);
379 translate(SSH2_MSG_USERAUTH_FAILURE);
380 translate(SSH2_MSG_USERAUTH_SUCCESS);
381 translate(SSH2_MSG_USERAUTH_BANNER);
acab36bc 382 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
383 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
384 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
385 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
00db133f 386 translate(SSH2_MSG_GLOBAL_REQUEST);
387 translate(SSH2_MSG_REQUEST_SUCCESS);
388 translate(SSH2_MSG_REQUEST_FAILURE);
389 translate(SSH2_MSG_CHANNEL_OPEN);
390 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
391 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
392 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
393 translate(SSH2_MSG_CHANNEL_DATA);
394 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
395 translate(SSH2_MSG_CHANNEL_EOF);
396 translate(SSH2_MSG_CHANNEL_CLOSE);
397 translate(SSH2_MSG_CHANNEL_REQUEST);
398 translate(SSH2_MSG_CHANNEL_SUCCESS);
399 translate(SSH2_MSG_CHANNEL_FAILURE);
400 return "unknown";
401}
402#undef translate
403#undef translatec
7d503c31 404
9a10ecf4 405/* Enumeration values for fields in SSH-1 packets */
406enum {
407 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
408 /* These values are for communicating relevant semantics of
409 * fields to the packet logging code. */
410 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
411};
972a41c8 412
acddebd9 413/*
414 * Coroutine mechanics for the sillier bits of the code. If these
415 * macros look impenetrable to you, you might find it helpful to
416 * read
417 *
418 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
419 *
420 * which explains the theory behind these macros.
b624d1e6 421 *
422 * In particular, if you are getting `case expression not constant'
423 * errors when building with MS Visual Studio, this is because MS's
424 * Edit and Continue debugging feature causes their compiler to
425 * violate ANSI C. To disable Edit and Continue debugging:
426 *
427 * - right-click ssh.c in the FileView
428 * - click Settings
429 * - select the C/C++ tab and the General category
430 * - under `Debug info:', select anything _other_ than `Program
431 * Database for Edit and Continue'.
acddebd9 432 */
51470298 433#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
30919997 434#define crBeginState crBegin(s->crLine)
435#define crStateP(t, v) \
436 struct t *s; \
437 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
438 s = (v);
439#define crState(t) crStateP(t, ssh->t)
51470298 440#define crFinish(z) } *crLine = 0; return (z); }
441#define crFinishV } *crLine = 0; return; }
5ca12719 442#define crFinishFree(z, s) } *crLine = 0; sfree(s); return (z); }
443#define crFinishFreeV(s) } *crLine = 0; sfree(s); return; }
374330e2 444#define crReturn(z) \
445 do {\
51470298 446 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 447 } while (0)
448#define crReturnV \
449 do {\
51470298 450 *crLine=__LINE__; return; case __LINE__:;\
374330e2 451 } while (0)
51470298 452#define crStop(z) do{ *crLine = 0; return (z); }while(0)
453#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 454#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 455#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 456
51470298 457typedef struct ssh_tag *Ssh;
ff3187f6 458struct Packet;
459
dacd8872 460static struct Packet *ssh1_pkt_init(int pkt_type);
ff3187f6 461static struct Packet *ssh2_pkt_init(int pkt_type);
dacd8872 462static void ssh_pkt_ensure(struct Packet *, int length);
463static void ssh_pkt_adddata(struct Packet *, void *data, int len);
464static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
ff3187f6 465static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
dacd8872 466static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
467static void ssh_pkt_addstring_start(struct Packet *);
468static void ssh_pkt_addstring_str(struct Packet *, char *data);
469static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
470static void ssh_pkt_addstring(struct Packet *, char *data);
d8baa528 471static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
dacd8872 472static void ssh1_pkt_addmp(struct Packet *, Bignum b);
ff3187f6 473static void ssh2_pkt_addmp(struct Packet *, Bignum b);
474static int ssh2_pkt_construct(Ssh, struct Packet *);
475static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 476static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 477static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
478 struct Packet *pktin);
479static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
480 struct Packet *pktin);
997097db 481static void ssh2_channel_check_close(struct ssh_channel *c);
bc06669b 482static void ssh_channel_destroy(struct ssh_channel *c);
3d63ca2e 483
5471d09a 484/*
485 * Buffer management constants. There are several of these for
486 * various different purposes:
487 *
488 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
489 * on a local data stream before we throttle the whole SSH
2e85c969 490 * connection (in SSH-1 only). Throttling the whole connection is
5471d09a 491 * pretty drastic so we set this high in the hope it won't
492 * happen very often.
493 *
494 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
495 * on the SSH connection itself before we defensively throttle
496 * _all_ local data streams. This is pretty drastic too (though
2e85c969 497 * thankfully unlikely in SSH-2 since the window mechanism should
5471d09a 498 * ensure that the server never has any need to throttle its end
499 * of the connection), so we set this high as well.
500 *
2e85c969 501 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
5471d09a 502 * channels.
9b53e9b8 503 *
504 * - OUR_V2_BIGWIN is the window size we advertise for the only
3361b80a 505 * channel in a simple connection. It must be <= INT_MAX.
9916cc1e 506 *
507 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
508 * to the remote side. This actually has nothing to do with the
509 * size of the _packet_, but is instead a limit on the amount
510 * of data we're willing to receive in a single SSH2 channel
511 * data message.
512 *
513 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
514 * _packet_ we're prepared to cope with. It must be a multiple
515 * of the cipher block size, and must be at least 35000.
5471d09a 516 */
517
518#define SSH1_BUFFER_LIMIT 32768
519#define SSH_MAX_BACKLOG 32768
520#define OUR_V2_WINSIZE 16384
3361b80a 521#define OUR_V2_BIGWIN 0x7fffffff
954d5c5a 522#define OUR_V2_MAXPKT 0x4000UL
9916cc1e 523#define OUR_V2_PACKETLIMIT 0x9000UL
d74d141c 524
85cc02bb 525const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 526
8b2715b2 527const static struct ssh_mac *macs[] = {
6668a75e 528 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
32874aea 529};
8b2715b2 530const static struct ssh_mac *buggymacs[] = {
6668a75e 531 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
32874aea 532};
e5574168 533
5366aed8 534static void *ssh_comp_none_init(void)
535{
536 return NULL;
537}
538static void ssh_comp_none_cleanup(void *handle)
32874aea 539{
540}
5366aed8 541static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 542 unsigned char **outblock, int *outlen)
543{
544 return 0;
545}
5366aed8 546static int ssh_comp_none_disable(void *handle)
32874aea 547{
4ba9b64b 548 return 0;
549}
57476f6b 550const static struct ssh_compress ssh_comp_none = {
ab18ccff 551 "none", NULL,
5366aed8 552 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
553 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
554 ssh_comp_none_disable, NULL
e5574168 555};
4ba9b64b 556extern const struct ssh_compress ssh_zlib;
557const static struct ssh_compress *compressions[] = {
32874aea 558 &ssh_zlib, &ssh_comp_none
559};
374330e2 560
32874aea 561enum { /* channel types */
783415f8 562 CHAN_MAINSESSION,
563 CHAN_X11,
564 CHAN_AGENT,
bc240b21 565 CHAN_SOCKDATA,
c6b41791 566 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
567 /*
568 * CHAN_ZOMBIE is used to indicate a channel for which we've
569 * already destroyed the local data source: for instance, if a
570 * forwarded port experiences a socket error on the local side, we
571 * immediately destroy its local socket and turn the SSH channel
572 * into CHAN_ZOMBIE.
573 */
574 CHAN_ZOMBIE
783415f8 575};
576
39d830e4 577typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
578typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
579typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
580
581/*
582 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
583 * handlers.
584 */
585struct outstanding_channel_request {
586 cchandler_fn_t handler;
587 void *ctx;
588 struct outstanding_channel_request *next;
589};
590
dacbd0e8 591/*
0e443c99 592 * little structure to keep track of outstanding WINDOW_ADJUSTs
593 */
594struct winadj {
595 struct winadj *next;
596 unsigned size;
597};
598
599/*
dacbd0e8 600 * 2-3-4 tree storing channels.
601 */
602struct ssh_channel {
51470298 603 Ssh ssh; /* pointer back to main context */
d211621f 604 unsigned remoteid, localid;
dacbd0e8 605 int type;
64d6ff88 606 /* True if we opened this channel but server hasn't confirmed. */
607 int halfopen;
0357890f 608 /*
2e85c969 609 * In SSH-1, this value contains four bits:
0357890f 610 *
611 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
612 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
613 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
614 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
615 *
616 * A channel is completely finished with when all four bits are set.
bc06669b 617 *
618 * In SSH-2, the four bits mean:
619 *
620 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
621 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
622 * 4 We have received SSH2_MSG_CHANNEL_EOF.
623 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
624 *
625 * A channel is completely finished with when we have both sent
626 * and received CLOSE.
627 *
628 * The symbolic constants below use the SSH-2 terminology, which
629 * is a bit confusing in SSH-1, but we have to use _something_.
0357890f 630 */
bc06669b 631#define CLOSES_SENT_EOF 1
632#define CLOSES_SENT_CLOSE 2
633#define CLOSES_RCVD_EOF 4
634#define CLOSES_RCVD_CLOSE 8
dacbd0e8 635 int closes;
78280721 636
637 /*
bc06669b 638 * This flag indicates that an EOF is pending on the outgoing side
639 * of the channel: that is, wherever we're getting the data for
640 * this channel has sent us some data followed by EOF. We can't
641 * actually send the EOF until we've finished sending the data, so
642 * we set this flag instead to remind us to do so once our buffer
643 * is clear.
78280721 644 */
bc06669b 645 int pending_eof;
78280721 646
ff68564b 647 /*
648 * True if this channel is causing the underlying connection to be
649 * throttled.
650 */
651 int throttling_conn;
5471d09a 652 union {
5471d09a 653 struct ssh2_data_channel {
654 bufchain outbuffer;
655 unsigned remwindow, remmaxpkt;
467e064d 656 /* locwindow is signed so we can cope with excess data. */
9b53e9b8 657 int locwindow, locmaxwin;
0e443c99 658 /*
659 * remlocwin is the amount of local window that we think
660 * the remote end had available to it after it sent the
661 * last data packet or window adjust ack.
662 */
663 int remlocwin;
664 /*
39d830e4 665 * These store the list of channel requests that haven't
0e443c99 666 * been acked.
667 */
39d830e4 668 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
0e443c99 669 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
5471d09a 670 } v2;
671 } v;
dacbd0e8 672 union {
32874aea 673 struct ssh_agent_channel {
674 unsigned char *message;
675 unsigned char msglen[4];
a03c9f9c 676 unsigned lensofar, totallen;
32874aea 677 } a;
678 struct ssh_x11_channel {
679 Socket s;
680 } x11;
d74d141c 681 struct ssh_pfd_channel {
682 Socket s;
683 } pfd;
dacbd0e8 684 } u;
685};
57476f6b 686
d74d141c 687/*
2e85c969 688 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
689 * use this structure in different ways, reflecting SSH-2's
bc240b21 690 * altogether saner approach to port forwarding.
691 *
2e85c969 692 * In SSH-1, you arrange a remote forwarding by sending the server
bc240b21 693 * the remote port number, and the local destination host:port.
694 * When a connection comes in, the server sends you back that
695 * host:port pair, and you connect to it. This is a ready-made
696 * security hole if you're not on the ball: a malicious server
697 * could send you back _any_ host:port pair, so if you trustingly
698 * connect to the address it gives you then you've just opened the
699 * entire inside of your corporate network just by connecting
700 * through it to a dodgy SSH server. Hence, we must store a list of
701 * host:port pairs we _are_ trying to forward to, and reject a
702 * connection request from the server if it's not in the list.
703 *
2e85c969 704 * In SSH-2, each side of the connection minds its own business and
bc240b21 705 * doesn't send unnecessary information to the other. You arrange a
706 * remote forwarding by sending the server just the remote port
707 * number. When a connection comes in, the server tells you which
708 * of its ports was connected to; and _you_ have to remember what
709 * local host:port pair went with that port number.
710 *
2e85c969 711 * Hence, in SSH-1 this structure is indexed by destination
712 * host:port pair, whereas in SSH-2 it is indexed by source port.
d74d141c 713 */
fda2feb1 714struct ssh_portfwd; /* forward declaration */
715
d74d141c 716struct ssh_rportfwd {
bc240b21 717 unsigned sport, dport;
718 char dhost[256];
06fadff5 719 char *sportdesc;
fda2feb1 720 struct ssh_portfwd *pfrec;
d74d141c 721};
fda2feb1 722#define free_rportfwd(pf) ( \
723 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
724
725/*
726 * Separately to the rportfwd tree (which is for looking up port
727 * open requests from the server), a tree of _these_ structures is
728 * used to keep track of all the currently open port forwardings,
729 * so that we can reconfigure in mid-session if the user requests
730 * it.
731 */
732struct ssh_portfwd {
84328ddb 733 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 734 int type;
735 unsigned sport, dport;
736 char *saddr, *daddr;
3fe92132 737 char *sserv, *dserv;
fda2feb1 738 struct ssh_rportfwd *remote;
05581745 739 int addressfamily;
fda2feb1 740 void *local;
741};
742#define free_portfwd(pf) ( \
3fe92132 743 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
744 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 745
57476f6b 746struct Packet {
dacd8872 747 long length; /* length of `data' actually used */
748 long forcepad; /* SSH-2: force padding to at least this length */
749 int type; /* only used for incoming packets */
750 unsigned long sequence; /* SSH-2 incoming sequence number */
751 unsigned char *data; /* allocated storage */
752 unsigned char *body; /* offset of payload within `data' */
753 long savedpos; /* temporary index into `data' (for strings) */
754 long maxlen; /* amount of storage allocated for `data' */
755 long encrypted_len; /* for SSH-2 total-size counting */
ff3187f6 756
757 /*
758 * State associated with packet logging
759 */
760 int logmode;
761 int nblanks;
762 struct logblank_t *blanks;
57476f6b 763};
764
1c1a7262 765static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 766 struct Packet *pktin);
1c1a7262 767static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 768 struct Packet *pktin);
b09eaa88 769static void ssh1_protocol_setup(Ssh ssh);
770static void ssh2_protocol_setup(Ssh ssh);
51470298 771static void ssh_size(void *handle, int width, int height);
772static void ssh_special(void *handle, Telnet_Special);
5471d09a 773static int ssh2_try_send(struct ssh_channel *c);
51470298 774static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
775static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
9fca3f8c 776static void ssh2_set_window(struct ssh_channel *c, int newwin);
51470298 777static int ssh_sendbuffer(void *handle);
ac934965 778static int ssh_do_close(Ssh ssh, int notify_exit);
ff3187f6 779static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
780static int ssh2_pkt_getbool(struct Packet *pkt);
781static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 782static void ssh2_timer(void *ctx, long now);
1c1a7262 783static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
9442dd57 784 struct Packet *pktin);
39d830e4 785static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
57476f6b 786
51470298 787struct rdpkt1_state_tag {
57476f6b 788 long len, pad, biglen, to_read;
789 unsigned long realcrc, gotcrc;
790 unsigned char *p;
791 int i;
792 int chunk;
ff3187f6 793 struct Packet *pktin;
51470298 794};
57476f6b 795
51470298 796struct rdpkt2_state_tag {
960e736a 797 long len, pad, payload, packetlen, maclen;
798 int i;
799 int cipherblk;
800 unsigned long incoming_sequence;
ff3187f6 801 struct Packet *pktin;
51470298 802};
803
06fadff5 804struct queued_handler;
805struct queued_handler {
806 int msg1, msg2;
807 chandler_fn_t handler;
808 void *ctx;
809 struct queued_handler *next;
810};
b09eaa88 811
51470298 812struct ssh_tag {
813 const struct plug_function_table *fn;
814 /* the above field _must_ be first in the structure */
815
4320baf7 816 char *v_c, *v_s;
b672f405 817 void *exhash;
51470298 818
819 Socket s;
820
b9d7bcad 821 void *ldisc;
a8327734 822 void *logctx;
b9d7bcad 823
51470298 824 unsigned char session_key[32];
825 int v1_compressing;
826 int v1_remote_protoflags;
827 int v1_local_protoflags;
828 int agentfwd_enabled;
829 int X11_fwd_enabled;
830 int remote_bugs;
831 const struct ssh_cipher *cipher;
371e569c 832 void *v1_cipher_ctx;
0183b242 833 void *crcda_ctx;
51470298 834 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 835 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 836 const struct ssh_mac *csmac, *scmac;
e0e1a00d 837 void *cs_mac_ctx, *sc_mac_ctx;
51470298 838 const struct ssh_compress *cscomp, *sccomp;
5366aed8 839 void *cs_comp_ctx, *sc_comp_ctx;
51470298 840 const struct ssh_kex *kex;
841 const struct ssh_signkey *hostkey;
754c0df9 842 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
b672f405 843 int v2_session_id_len;
27cd7fc2 844 void *kex_ctx;
51470298 845
846 char *savedhost;
847 int savedport;
848 int send_ok;
849 int echoing, editing;
850
851 void *frontend;
852
db219738 853 int ospeed, ispeed; /* temporaries */
51470298 854 int term_width, term_height;
855
856 tree234 *channels; /* indexed by local id */
857 struct ssh_channel *mainchan; /* primary session channel */
feb02b4e 858 int ncmode; /* is primary channel direct-tcpip? */
51470298 859 int exitcode;
ac934965 860 int close_expected;
9e296bfa 861 int clean_exit;
51470298 862
fda2feb1 863 tree234 *rportfwds, *portfwds;
51470298 864
865 enum {
866 SSH_STATE_PREPACKET,
867 SSH_STATE_BEFORE_SIZE,
868 SSH_STATE_INTERMED,
869 SSH_STATE_SESSION,
870 SSH_STATE_CLOSED
871 } state;
872
873 int size_needed, eof_needed;
bc06669b 874 int sent_console_eof;
4a202fc6 875 int got_pty; /* affects EOF behaviour on main channel */
51470298 876
590f6a5f 877 struct Packet **queue;
878 int queuelen, queuesize;
879 int queueing;
51470298 880 unsigned char *deferred_send_data;
881 int deferred_len, deferred_size;
882
883 /*
884 * Gross hack: pscp will try to start SFTP but fall back to
885 * scp1 if that fails. This variable is the means by which
886 * scp.c can reach into the SSH code and find out which one it
887 * got.
888 */
889 int fallback_cmd;
890
6bbce591 891 bufchain banner; /* accumulates banners during do_ssh2_authconn */
51470298 892
acab36bc 893 Pkt_KCtx pkt_kctx;
894 Pkt_ACtx pkt_actx;
51470298 895
8def70c3 896 struct X11Display *x11disp;
302121de 897
51470298 898 int version;
ff68564b 899 int conn_throttle_count;
51470298 900 int overall_bufsize;
901 int throttled_all;
902 int v1_stdout_throttling;
a8756193 903 unsigned long v2_outgoing_sequence;
51470298 904
905 int ssh1_rdpkt_crstate;
906 int ssh2_rdpkt_crstate;
51470298 907 int ssh_gotdata_crstate;
b09eaa88 908 int do_ssh1_connection_crstate;
51470298 909
910 void *do_ssh_init_state;
911 void *do_ssh1_login_state;
912 void *do_ssh2_transport_state;
913 void *do_ssh2_authconn_state;
914
915 struct rdpkt1_state_tag rdpkt1_state;
916 struct rdpkt2_state_tag rdpkt2_state;
917
2e85c969 918 /* SSH-1 and SSH-2 use this for different things, but both use it */
b09eaa88 919 int protocol_initial_phase_done;
920
1c1a7262 921 void (*protocol) (Ssh ssh, void *vin, int inlen,
ff3187f6 922 struct Packet *pkt);
923 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 924
925 /*
4a693cfc 926 * We maintain our own copy of a Conf structure here. That way,
927 * when we're passed a new one for reconfiguration, we can check
928 * the differences and potentially reconfigure port forwardings
929 * etc in mid-session.
86916870 930 */
4a693cfc 931 Conf *conf;
932
933 /*
934 * Values cached out of conf so as to avoid the tree234 lookup
935 * cost every time they're used.
936 */
937 int logomitdata;
938
939 /*
940 * Dynamically allocated username string created during SSH
941 * login. Stored in here rather than in the coroutine state so
942 * that it'll be reliably freed if we shut down the SSH session
943 * at some unexpected moment.
944 */
945 char *username;
839f10db 946
947 /*
3d9449a1 948 * Used to transfer data back from async callbacks.
839f10db 949 */
950 void *agent_response;
951 int agent_response_len;
3d9449a1 952 int user_response;
953
954 /*
955 * The SSH connection can be set as `frozen', meaning we are
956 * not currently accepting incoming data from the network. This
957 * is slightly more serious than setting the _socket_ as
958 * frozen, because we may already have had data passed to us
959 * from the network which we need to delay processing until
960 * after the freeze is lifted, so we also need a bufchain to
961 * store that data.
962 */
963 int frozen;
964 bufchain queued_incoming_data;
b09eaa88 965
966 /*
967 * Dispatch table for packet types that we may have to deal
968 * with at any time.
969 */
970 handler_fn_t packet_dispatch[256];
39934deb 971
972 /*
06fadff5 973 * Queues of one-off handler functions for success/failure
974 * indications from a request.
975 */
976 struct queued_handler *qhead, *qtail;
bc074147 977 handler_fn_t q_saved_handler1, q_saved_handler2;
06fadff5 978
979 /*
39934deb 980 * This module deals with sending keepalives.
981 */
982 Pinger pinger;
9442dd57 983
984 /*
985 * Track incoming and outgoing data sizes and time, for
986 * size-based rekeys.
987 */
988 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 989 unsigned long max_data_size;
9442dd57 990 int kex_in_progress;
e6c1536e 991 long next_rekey, last_rekey;
e13bba36 992 char *deferred_rekey_reason; /* points to STATIC string; don't free */
42af6a67 993
994 /*
995 * Fully qualified host name, which we need if doing GSSAPI.
996 */
997 char *fullhostname;
1e00c92b 998
999#ifndef NO_GSSAPI
1000 /*
1001 * GSSAPI libraries for this session.
1002 */
1003 struct ssh_gss_liblist *gsslibs;
1004#endif
51470298 1005};
960e736a 1006
382908ad 1007#define logevent(s) logevent(ssh->frontend, s)
a8327734 1008
1009/* logevent, only printf-formatted. */
cbe2d68f 1010static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 1011{
1012 va_list ap;
57356d63 1013 char *buf;
a8327734 1014
1015 va_start(ap, fmt);
57356d63 1016 buf = dupvprintf(fmt, ap);
a8327734 1017 va_end(ap);
57356d63 1018 logevent(buf);
57356d63 1019 sfree(buf);
a8327734 1020}
1021
6b5cf8b4 1022#define bombout(msg) \
1023 do { \
1024 char *text = dupprintf msg; \
ac934965 1025 ssh_do_close(ssh, FALSE); \
6b5cf8b4 1026 logevent(text); \
1027 connection_fatal(ssh->frontend, "%s", text); \
1028 sfree(text); \
1029 } while (0)
a8327734 1030
9a10ecf4 1031/* Functions to leave bits out of the SSH packet log file. */
1032
ff3187f6 1033static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1034{
4a693cfc 1035 if (conf_get_int(ssh->conf, CONF_logomitpass))
ff3187f6 1036 pkt->logmode = blanktype;
9a10ecf4 1037}
1038
ff3187f6 1039static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1040{
4a693cfc 1041 if (ssh->logomitdata)
ff3187f6 1042 pkt->logmode = blanktype;
9a10ecf4 1043}
1044
ff3187f6 1045static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 1046{
ff3187f6 1047 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 1048}
1049
4a693cfc 1050/* Helper function for common bits of parsing ttymodes. */
1051static void parse_ttymodes(Ssh ssh,
c6ccd5c2 1052 void (*do_mode)(void *data, char *mode, char *val),
1053 void *data)
1054{
4a693cfc 1055 char *key, *val;
1056
1057 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1058 val != NULL;
1059 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1060 /*
1061 * val[0] is either 'V', indicating that an explicit value
1062 * follows it, or 'A' indicating that we should pass the
1063 * value through from the local environment via get_ttymode.
1064 */
1065 if (val[0] == 'A')
1066 val = get_ttymode(ssh->frontend, key);
c6ccd5c2 1067 else
4a693cfc 1068 val++; /* skip the 'V' */
c6ccd5c2 1069 if (val)
4a693cfc 1070 do_mode(data, key, val);
c6ccd5c2 1071 }
1072}
1073
32874aea 1074static int ssh_channelcmp(void *av, void *bv)
1075{
1076 struct ssh_channel *a = (struct ssh_channel *) av;
1077 struct ssh_channel *b = (struct ssh_channel *) bv;
1078 if (a->localid < b->localid)
1079 return -1;
1080 if (a->localid > b->localid)
1081 return +1;
dacbd0e8 1082 return 0;
1083}
32874aea 1084static int ssh_channelfind(void *av, void *bv)
1085{
1086 unsigned *a = (unsigned *) av;
1087 struct ssh_channel *b = (struct ssh_channel *) bv;
1088 if (*a < b->localid)
1089 return -1;
1090 if (*a > b->localid)
1091 return +1;
dacbd0e8 1092 return 0;
1093}
1094
bc240b21 1095static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 1096{
1097 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1098 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1099 int i;
bc240b21 1100 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 1101 return i < 0 ? -1 : +1;
bc240b21 1102 if (a->dport > b->dport)
1103 return +1;
1104 if (a->dport < b->dport)
1105 return -1;
1106 return 0;
1107}
1108
1109static int ssh_rportcmp_ssh2(void *av, void *bv)
1110{
1111 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1112 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 1113
bc240b21 1114 if (a->sport > b->sport)
d74d141c 1115 return +1;
bc240b21 1116 if (a->sport < b->sport)
1117 return -1;
d74d141c 1118 return 0;
1119}
1120
fda2feb1 1121/*
1122 * Special form of strcmp which can cope with NULL inputs. NULL is
1123 * defined to sort before even the empty string.
1124 */
1125static int nullstrcmp(const char *a, const char *b)
1126{
1127 if (a == NULL && b == NULL)
1128 return 0;
1129 if (a == NULL)
1130 return -1;
1131 if (b == NULL)
1132 return +1;
1133 return strcmp(a, b);
1134}
1135
1136static int ssh_portcmp(void *av, void *bv)
1137{
1138 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1139 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1140 int i;
1141 if (a->type > b->type)
1142 return +1;
1143 if (a->type < b->type)
1144 return -1;
84328ddb 1145 if (a->addressfamily > b->addressfamily)
1146 return +1;
1147 if (a->addressfamily < b->addressfamily)
1148 return -1;
fda2feb1 1149 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1150 return i < 0 ? -1 : +1;
1151 if (a->sport > b->sport)
1152 return +1;
1153 if (a->sport < b->sport)
1154 return -1;
1155 if (a->type != 'D') {
1156 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1157 return i < 0 ? -1 : +1;
1158 if (a->dport > b->dport)
1159 return +1;
1160 if (a->dport < b->dport)
1161 return -1;
1162 }
1163 return 0;
1164}
1165
51470298 1166static int alloc_channel_id(Ssh ssh)
32874aea 1167{
260f3dec 1168 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1169 unsigned low, high, mid;
d2371c81 1170 int tsize;
1171 struct ssh_channel *c;
1172
1173 /*
1174 * First-fit allocation of channel numbers: always pick the
1175 * lowest unused one. To do this, binary-search using the
1176 * counted B-tree to find the largest channel ID which is in a
1177 * contiguous sequence from the beginning. (Precisely
1178 * everything in that sequence must have ID equal to its tree
1179 * index plus CHANNEL_NUMBER_OFFSET.)
1180 */
51470298 1181 tsize = count234(ssh->channels);
d2371c81 1182
32874aea 1183 low = -1;
1184 high = tsize;
d2371c81 1185 while (high - low > 1) {
1186 mid = (high + low) / 2;
51470298 1187 c = index234(ssh->channels, mid);
d2371c81 1188 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1189 low = mid; /* this one is fine */
1190 else
1191 high = mid; /* this one is past it */
1192 }
1193 /*
1194 * Now low points to either -1, or the tree index of the
1195 * largest ID in the initial sequence.
1196 */
1197 {
1198 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 1199 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 1200 }
1201 return low + 1 + CHANNEL_NUMBER_OFFSET;
1202}
1203
edd0cb8a 1204static void c_write_stderr(int trusted, const char *buf, int len)
1205{
1206 int i;
1207 for (i = 0; i < len; i++)
667deca9 1208 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
edd0cb8a 1209 fputc(buf[i], stderr);
1210}
1211
9fab77dc 1212static void c_write(Ssh ssh, const char *buf, int len)
32874aea 1213{
edd0cb8a 1214 if (flags & FLAG_STDERR)
1215 c_write_stderr(1, buf, len);
1216 else
1217 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 1218}
1219
9fab77dc 1220static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 1221{
edd0cb8a 1222 if (flags & FLAG_STDERR)
1223 c_write_stderr(0, buf, len);
1224 else
1225 from_backend_untrusted(ssh->frontend, buf, len);
a209e957 1226}
1227
9fab77dc 1228static void c_write_str(Ssh ssh, const char *buf)
32874aea 1229{
51470298 1230 c_write(ssh, buf, strlen(buf));
1408a877 1231}
1232
ff3187f6 1233static void ssh_free_packet(struct Packet *pkt)
1234{
1235 sfree(pkt->data);
1236 sfree(pkt);
1237}
1238static struct Packet *ssh_new_packet(void)
1239{
1240 struct Packet *pkt = snew(struct Packet);
1241
dacd8872 1242 pkt->body = pkt->data = NULL;
ff3187f6 1243 pkt->maxlen = 0;
1244 pkt->logmode = PKTLOG_EMIT;
1245 pkt->nblanks = 0;
1246 pkt->blanks = NULL;
1247
1248 return pkt;
1249}
1250
fb09bf1c 1251/*
1252 * Collect incoming data in the incoming packet buffer.
e5574168 1253 * Decipher and verify the packet when it is completely read.
1254 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 1255 * Update the *data and *datalen variables.
ff3187f6 1256 * Return a Packet structure when a packet is completed.
fb09bf1c 1257 */
ff3187f6 1258static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 1259{
51470298 1260 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 1261
51470298 1262 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 1263
ff3187f6 1264 st->pktin = ssh_new_packet();
1265
1266 st->pktin->type = 0;
1267 st->pktin->length = 0;
374330e2 1268
57476f6b 1269 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 1270 while ((*datalen) == 0)
ff3187f6 1271 crReturn(NULL);
57476f6b 1272 st->len = (st->len << 8) + **data;
fb09bf1c 1273 (*data)++, (*datalen)--;
1274 }
374330e2 1275
57476f6b 1276 st->pad = 8 - (st->len % 8);
1277 st->biglen = st->len + st->pad;
ff3187f6 1278 st->pktin->length = st->len - 5;
fb09bf1c 1279
ae0500e5 1280 if (st->biglen < 0) {
1281 bombout(("Extremely large packet length from server suggests"
1282 " data stream corruption"));
ff3187f6 1283 ssh_free_packet(st->pktin);
1284 crStop(NULL);
ae0500e5 1285 }
1286
ff3187f6 1287 st->pktin->maxlen = st->biglen;
1288 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1289
57476f6b 1290 st->to_read = st->biglen;
ff3187f6 1291 st->p = st->pktin->data;
57476f6b 1292 while (st->to_read > 0) {
32874aea 1293 st->chunk = st->to_read;
fb09bf1c 1294 while ((*datalen) == 0)
ff3187f6 1295 crReturn(NULL);
57476f6b 1296 if (st->chunk > (*datalen))
1297 st->chunk = (*datalen);
1298 memcpy(st->p, *data, st->chunk);
1299 *data += st->chunk;
1300 *datalen -= st->chunk;
1301 st->p += st->chunk;
1302 st->to_read -= st->chunk;
fb09bf1c 1303 }
374330e2 1304
ff3187f6 1305 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1306 st->biglen, NULL)) {
6b5cf8b4 1307 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1308 ssh_free_packet(st->pktin);
1309 crStop(NULL);
9a3a93a5 1310 }
1311
51470298 1312 if (ssh->cipher)
ff3187f6 1313 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1314
ff3187f6 1315 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1316 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1317 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1318 bombout(("Incorrect CRC received on packet"));
ff3187f6 1319 ssh_free_packet(st->pktin);
1320 crStop(NULL);
fb09bf1c 1321 }
572f871e 1322
ff3187f6 1323 st->pktin->body = st->pktin->data + st->pad + 1;
1324 st->pktin->savedpos = 0;
4ba9b64b 1325
51470298 1326 if (ssh->v1_compressing) {
4ba9b64b 1327 unsigned char *decompblk;
1328 int decomplen;
36b8d9bb 1329 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1330 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1331 &decompblk, &decomplen)) {
1332 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1333 ssh_free_packet(st->pktin);
1334 crStop(NULL);
36b8d9bb 1335 }
4ba9b64b 1336
ff3187f6 1337 if (st->pktin->maxlen < st->pad + decomplen) {
1338 st->pktin->maxlen = st->pad + decomplen;
1339 st->pktin->data = sresize(st->pktin->data,
1340 st->pktin->maxlen + APIEXTRA,
3d88e64d 1341 unsigned char);
ff3187f6 1342 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1343 }
1344
ff3187f6 1345 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1346 sfree(decompblk);
ff3187f6 1347 st->pktin->length = decomplen - 1;
4ba9b64b 1348 }
1349
ff3187f6 1350 st->pktin->type = st->pktin->body[-1];
00db133f 1351
9a10ecf4 1352 /*
1353 * Log incoming packet, possibly omitting sensitive fields.
1354 */
1355 if (ssh->logctx) {
1356 int nblanks = 0;
1357 struct logblank_t blank;
4a693cfc 1358 if (ssh->logomitdata) {
9a10ecf4 1359 int do_blank = FALSE, blank_prefix = 0;
1360 /* "Session data" packets - omit the data field */
ff3187f6 1361 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1362 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1363 do_blank = TRUE; blank_prefix = 4;
a2724fba 1364 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1365 do_blank = TRUE; blank_prefix = 8;
9a10ecf4 1366 }
1367 if (do_blank) {
1368 blank.offset = blank_prefix;
ff3187f6 1369 blank.len = st->pktin->length;
9a10ecf4 1370 blank.type = PKTLOG_OMIT;
1371 nblanks = 1;
1372 }
1373 }
a8327734 1374 log_packet(ssh->logctx,
ff3187f6 1375 PKT_INCOMING, st->pktin->type,
1376 ssh1_pkt_type(st->pktin->type),
1377 st->pktin->body, st->pktin->length,
0d13bfcd 1378 nblanks, &blank, NULL);
9a10ecf4 1379 }
00db133f 1380
ff3187f6 1381 crFinish(st->pktin);
fb09bf1c 1382}
1383
ff3187f6 1384static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1385{
51470298 1386 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1387
51470298 1388 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1389
ff3187f6 1390 st->pktin = ssh_new_packet();
1391
1392 st->pktin->type = 0;
1393 st->pktin->length = 0;
51470298 1394 if (ssh->sccipher)
1395 st->cipherblk = ssh->sccipher->blksize;
e5574168 1396 else
32874aea 1397 st->cipherblk = 8;
960e736a 1398 if (st->cipherblk < 8)
32874aea 1399 st->cipherblk = 8;
9916cc1e 1400 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
960e736a 1401
9916cc1e 1402 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1403 ssh->scmac) {
1404 /*
1405 * When dealing with a CBC-mode cipher, we want to avoid the
1406 * possibility of an attacker's tweaking the ciphertext stream
1407 * so as to cause us to feed the same block to the block
1408 * cipher more than once and thus leak information
1409 * (VU#958563). The way we do this is not to take any
1410 * decisions on the basis of anything we've decrypted until
1411 * we've verified it with a MAC. That includes the packet
1412 * length, so we just read data and check the MAC repeatedly,
1413 * and when the MAC passes, see if the length we've got is
1414 * plausible.
1415 */
1416
1417 /* May as well allocate the whole lot now. */
1418 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1419 unsigned char);
1420
1421 /* Read an amount corresponding to the MAC. */
1422 for (st->i = 0; st->i < st->maclen; st->i++) {
1423 while ((*datalen) == 0)
1424 crReturn(NULL);
1425 st->pktin->data[st->i] = *(*data)++;
1426 (*datalen)--;
1427 }
e5574168 1428
9916cc1e 1429 st->packetlen = 0;
1430 {
1431 unsigned char seq[4];
1432 ssh->scmac->start(ssh->sc_mac_ctx);
1433 PUT_32BIT(seq, st->incoming_sequence);
1434 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1435 }
4252c9cc 1436
9916cc1e 1437 for (;;) { /* Once around this loop per cipher block. */
1438 /* Read another cipher-block's worth, and tack it onto the end. */
1439 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1440 while ((*datalen) == 0)
1441 crReturn(NULL);
1442 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1443 (*datalen)--;
1444 }
1445 /* Decrypt one more block (a little further back in the stream). */
1446 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1447 st->pktin->data + st->packetlen,
1448 st->cipherblk);
1449 /* Feed that block to the MAC. */
1450 ssh->scmac->bytes(ssh->sc_mac_ctx,
1451 st->pktin->data + st->packetlen, st->cipherblk);
1452 st->packetlen += st->cipherblk;
1453 /* See if that gives us a valid packet. */
1454 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1455 st->pktin->data + st->packetlen) &&
1456 (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen)
1457 break;
1458 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1459 bombout(("No valid incoming packet found"));
1460 ssh_free_packet(st->pktin);
1461 crStop(NULL);
1462 }
1463 }
1464 st->pktin->maxlen = st->packetlen + st->maclen;
1465 st->pktin->data = sresize(st->pktin->data,
1466 st->pktin->maxlen + APIEXTRA,
1467 unsigned char);
1468 } else {
1469 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1470
1471 /*
1472 * Acquire and decrypt the first block of the packet. This will
1473 * contain the length and padding details.
1474 */
1475 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1476 while ((*datalen) == 0)
1477 crReturn(NULL);
1478 st->pktin->data[st->i] = *(*data)++;
1479 (*datalen)--;
1480 }
e5574168 1481
9916cc1e 1482 if (ssh->sccipher)
1483 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1484 st->pktin->data, st->cipherblk);
1485
1486 /*
1487 * Now get the length figure.
1488 */
1489 st->len = GET_32BIT(st->pktin->data);
1490
1491 /*
1492 * _Completely_ silly lengths should be stomped on before they
1493 * do us any more damage.
1494 */
1495 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1496 (st->len + 4) % st->cipherblk != 0) {
1497 bombout(("Incoming packet was garbled on decryption"));
1498 ssh_free_packet(st->pktin);
1499 crStop(NULL);
1500 }
e5574168 1501
9916cc1e 1502 /*
1503 * So now we can work out the total packet length.
1504 */
1505 st->packetlen = st->len + 4;
1506
1507 /*
1508 * Allocate memory for the rest of the packet.
1509 */
1510 st->pktin->maxlen = st->packetlen + st->maclen;
1511 st->pktin->data = sresize(st->pktin->data,
1512 st->pktin->maxlen + APIEXTRA,
1513 unsigned char);
1514
1515 /*
1516 * Read and decrypt the remainder of the packet.
1517 */
1518 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1519 st->i++) {
1520 while ((*datalen) == 0)
1521 crReturn(NULL);
1522 st->pktin->data[st->i] = *(*data)++;
1523 (*datalen)--;
1524 }
1525 /* Decrypt everything _except_ the MAC. */
1526 if (ssh->sccipher)
1527 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1528 st->pktin->data + st->cipherblk,
1529 st->packetlen - st->cipherblk);
1530
1531 /*
1532 * Check the MAC.
1533 */
1534 if (ssh->scmac
1535 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1536 st->len + 4, st->incoming_sequence)) {
1537 bombout(("Incorrect MAC received on packet"));
1538 ssh_free_packet(st->pktin);
1539 crStop(NULL);
1540 }
1541 }
1542 /* Get and sanity-check the amount of random padding. */
1543 st->pad = st->pktin->data[4];
1544 if (st->pad < 4 || st->len - st->pad < 1) {
1545 bombout(("Invalid padding length on received packet"));
ff3187f6 1546 ssh_free_packet(st->pktin);
1547 crStop(NULL);
717dc483 1548 }
717dc483 1549 /*
e5574168 1550 * This enables us to deduce the payload length.
1551 */
960e736a 1552 st->payload = st->len - st->pad - 1;
e5574168 1553
ff3187f6 1554 st->pktin->length = st->payload + 5;
9442dd57 1555 st->pktin->encrypted_len = st->packetlen;
1556
b09eaa88 1557 st->pktin->sequence = st->incoming_sequence++;
e5574168 1558
4ba9b64b 1559 /*
1560 * Decompress packet payload.
1561 */
1562 {
1563 unsigned char *newpayload;
1564 int newlen;
51470298 1565 if (ssh->sccomp &&
5366aed8 1566 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1567 st->pktin->data + 5, st->pktin->length - 5,
51470298 1568 &newpayload, &newlen)) {
ff3187f6 1569 if (st->pktin->maxlen < newlen + 5) {
1570 st->pktin->maxlen = newlen + 5;
1571 st->pktin->data = sresize(st->pktin->data,
1572 st->pktin->maxlen + APIEXTRA,
3d88e64d 1573 unsigned char);
4ba9b64b 1574 }
ff3187f6 1575 st->pktin->length = 5 + newlen;
1576 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1577 sfree(newpayload);
4ba9b64b 1578 }
1579 }
1580
ff3187f6 1581 st->pktin->savedpos = 6;
1582 st->pktin->body = st->pktin->data;
1583 st->pktin->type = st->pktin->data[5];
e5574168 1584
9a10ecf4 1585 /*
1586 * Log incoming packet, possibly omitting sensitive fields.
1587 */
1588 if (ssh->logctx) {
1589 int nblanks = 0;
1590 struct logblank_t blank;
4a693cfc 1591 if (ssh->logomitdata) {
9a10ecf4 1592 int do_blank = FALSE, blank_prefix = 0;
1593 /* "Session data" packets - omit the data field */
ff3187f6 1594 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1595 do_blank = TRUE; blank_prefix = 8;
a2724fba 1596 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1597 do_blank = TRUE; blank_prefix = 12;
9a10ecf4 1598 }
1599 if (do_blank) {
1600 blank.offset = blank_prefix;
ff3187f6 1601 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1602 blank.type = PKTLOG_OMIT;
1603 nblanks = 1;
1604 }
1605 }
ff3187f6 1606 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
acab36bc 1607 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1608 st->pktin->type),
ff3187f6 1609 st->pktin->data+6, st->pktin->length-6,
0d13bfcd 1610 nblanks, &blank, &st->pktin->sequence);
9a10ecf4 1611 }
00db133f 1612
ff3187f6 1613 crFinish(st->pktin);
e5574168 1614}
1615
dacd8872 1616static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
32874aea 1617{
dacd8872 1618 int pad, biglen, i, pktoffs;
374330e2 1619 unsigned long crc;
fd7a4aad 1620#ifdef __SC__
1621 /*
1622 * XXX various versions of SC (including 8.8.4) screw up the
1623 * register allocation in this function and use the same register
1624 * (D6) for len and as a temporary, with predictable results. The
1625 * following sledgehammer prevents this.
1626 */
1627 volatile
1628#endif
1629 int len;
374330e2 1630
a8327734 1631 if (ssh->logctx)
dacd8872 1632 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1633 ssh1_pkt_type(pkt->data[12]),
1634 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1635 pkt->nblanks, pkt->blanks, NULL);
ff3187f6 1636 sfree(pkt->blanks); pkt->blanks = NULL;
1637 pkt->nblanks = 0;
00db133f 1638
51470298 1639 if (ssh->v1_compressing) {
4ba9b64b 1640 unsigned char *compblk;
1641 int complen;
5366aed8 1642 zlib_compress_block(ssh->cs_comp_ctx,
dacd8872 1643 pkt->data + 12, pkt->length - 12,
4ba9b64b 1644 &compblk, &complen);
48406e6b 1645 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
dacd8872 1646 memcpy(pkt->data + 12, compblk, complen);
dcbde236 1647 sfree(compblk);
dacd8872 1648 pkt->length = complen + 12;
4ba9b64b 1649 }
1650
dacd8872 1651 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1652 pkt->length += 4;
1653 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
32874aea 1654 pad = 8 - (len % 8);
dacd8872 1655 pktoffs = 8 - pad;
1656 biglen = len + pad; /* len(padding+type+data+CRC) */
374330e2 1657
dacd8872 1658 for (i = pktoffs; i < 4+8; i++)
1659 pkt->data[i] = random_byte();
1660 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1661 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1662 PUT_32BIT(pkt->data + pktoffs, len);
374330e2 1663
51470298 1664 if (ssh->cipher)
dacd8872 1665 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1666 pkt->data + pktoffs + 4, biglen);
374330e2 1667
dacd8872 1668 if (offset_p) *offset_p = pktoffs;
1669 return biglen + 4; /* len(length+padding+type+data+CRC) */
39065bed 1670}
1671
bf8a49a1 1672static int s_write(Ssh ssh, void *data, int len)
1673{
ff05dfef 1674 if (ssh->logctx)
0d13bfcd 1675 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1676 0, NULL, NULL);
bf8a49a1 1677 return sk_write(ssh->s, (char *)data, len);
1678}
1679
ff3187f6 1680static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1681{
dacd8872 1682 int len, backlog, offset;
1683 len = s_wrpkt_prepare(ssh, pkt, &offset);
bf8a49a1 1684 backlog = s_write(ssh, pkt->data + offset, len);
5471d09a 1685 if (backlog > SSH_MAX_BACKLOG)
51470298 1686 ssh_throttle_all(ssh, 1, backlog);
dacd8872 1687 ssh_free_packet(pkt);
39065bed 1688}
1689
ff3187f6 1690static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1691{
dacd8872 1692 int len, offset;
1693 len = s_wrpkt_prepare(ssh, pkt, &offset);
51470298 1694 if (ssh->deferred_len + len > ssh->deferred_size) {
1695 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1696 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1697 ssh->deferred_size,
1698 unsigned char);
39065bed 1699 }
dacd8872 1700 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1701 pkt->data + offset, len);
51470298 1702 ssh->deferred_len += len;
dacd8872 1703 ssh_free_packet(pkt);
374330e2 1704}
1705
fb09bf1c 1706/*
dacd8872 1707 * Construct a SSH-1 packet with the specified contents.
1708 * (This all-at-once interface used to be the only one, but now SSH-1
1709 * packets can also be constructed incrementally.)
fb09bf1c 1710 */
dacd8872 1711static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
fb09bf1c 1712{
dacd8872 1713 int argtype;
7cca0d81 1714 Bignum bn;
ff3187f6 1715 struct Packet *pkt;
fb09bf1c 1716
dacd8872 1717 pkt = ssh1_pkt_init(pkttype);
fb09bf1c 1718
dacd8872 1719 while ((argtype = va_arg(ap, int)) != PKT_END) {
1720 unsigned char *argp, argchar;
8a9977e5 1721 char *sargp;
dacd8872 1722 unsigned long argint;
1723 int arglen;
fb09bf1c 1724 switch (argtype) {
9a10ecf4 1725 /* Actual fields in the packet */
fb09bf1c 1726 case PKT_INT:
dacd8872 1727 argint = va_arg(ap, int);
1728 ssh_pkt_adduint32(pkt, argint);
fb09bf1c 1729 break;
1730 case PKT_CHAR:
dacd8872 1731 argchar = (unsigned char) va_arg(ap, int);
1732 ssh_pkt_addbyte(pkt, argchar);
fb09bf1c 1733 break;
1734 case PKT_DATA:
dacd8872 1735 argp = va_arg(ap, unsigned char *);
1736 arglen = va_arg(ap, int);
1737 ssh_pkt_adddata(pkt, argp, arglen);
fb09bf1c 1738 break;
1739 case PKT_STR:
8a9977e5 1740 sargp = va_arg(ap, char *);
1741 ssh_pkt_addstring(pkt, sargp);
fb09bf1c 1742 break;
7cca0d81 1743 case PKT_BIGNUM:
dacd8872 1744 bn = va_arg(ap, Bignum);
1745 ssh1_pkt_addmp(pkt, bn);
9a10ecf4 1746 break;
1747 /* Tokens for modifications to packet logging */
1748 case PKTT_PASSWORD:
ff3187f6 1749 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1750 break;
1751 case PKTT_DATA:
ff3187f6 1752 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1753 break;
9a10ecf4 1754 case PKTT_OTHER:
ff3187f6 1755 end_log_omission(ssh, pkt);
9a10ecf4 1756 break;
1757 }
fb09bf1c 1758 }
ff3187f6 1759
1760 return pkt;
39065bed 1761}
fb09bf1c 1762
51470298 1763static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1764{
ff3187f6 1765 struct Packet *pkt;
dacd8872 1766 va_list ap;
1767 va_start(ap, pkttype);
1768 pkt = construct_packet(ssh, pkttype, ap);
1769 va_end(ap);
ff3187f6 1770 s_wrpkt(ssh, pkt);
fb09bf1c 1771}
1772
51470298 1773static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1774{
ff3187f6 1775 struct Packet *pkt;
dacd8872 1776 va_list ap;
1777 va_start(ap, pkttype);
1778 pkt = construct_packet(ssh, pkttype, ap);
1779 va_end(ap);
ff3187f6 1780 s_wrpkt_defer(ssh, pkt);
39065bed 1781}
1782
32874aea 1783static int ssh_versioncmp(char *a, char *b)
1784{
9697bfd2 1785 char *ae, *be;
1786 unsigned long av, bv;
1787
43aa02a7 1788 av = strtoul(a, &ae, 10);
1789 bv = strtoul(b, &be, 10);
32874aea 1790 if (av != bv)
1791 return (av < bv ? -1 : +1);
1792 if (*ae == '.')
1793 ae++;
1794 if (*be == '.')
1795 be++;
43aa02a7 1796 av = strtoul(ae, &ae, 10);
1797 bv = strtoul(be, &be, 10);
32874aea 1798 if (av != bv)
1799 return (av < bv ? -1 : +1);
9697bfd2 1800 return 0;
1801}
1802
e5574168 1803/*
a92dd380 1804 * Utility routines for putting an SSH-protocol `string' and
b672f405 1805 * `uint32' into a hash state.
e5574168 1806 */
b672f405 1807static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
32874aea 1808{
e5574168 1809 unsigned char lenblk[4];
e5574168 1810 PUT_32BIT(lenblk, len);
b672f405 1811 h->bytes(s, lenblk, 4);
1812 h->bytes(s, str, len);
e5574168 1813}
1814
b672f405 1815static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
32874aea 1816{
a92dd380 1817 unsigned char intblk[4];
1818 PUT_32BIT(intblk, i);
b672f405 1819 h->bytes(s, intblk, 4);
a92dd380 1820}
1821
7cca0d81 1822/*
dacd8872 1823 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
7cca0d81 1824 */
dacd8872 1825static void ssh_pkt_ensure(struct Packet *pkt, int length)
32874aea 1826{
ff3187f6 1827 if (pkt->maxlen < length) {
dacd8872 1828 unsigned char *body = pkt->body;
3d71de0b 1829 int offset = body ? body - pkt->data : 0;
ff3187f6 1830 pkt->maxlen = length + 256;
1831 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
dacd8872 1832 if (body) pkt->body = pkt->data + offset;
7cca0d81 1833 }
783415f8 1834}
dacd8872 1835static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1836{
ff3187f6 1837 if (pkt->logmode != PKTLOG_EMIT) {
1838 pkt->nblanks++;
1839 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
dacd8872 1840 assert(pkt->body);
1841 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1842 (pkt->body - pkt->data);
ff3187f6 1843 pkt->blanks[pkt->nblanks-1].len = len;
1844 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1845 }
1846 pkt->length += len;
dacd8872 1847 ssh_pkt_ensure(pkt, pkt->length);
ff3187f6 1848 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1849}
dacd8872 1850static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1851{
dacd8872 1852 ssh_pkt_adddata(pkt, &byte, 1);
7cca0d81 1853}
ff3187f6 1854static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1855{
dacd8872 1856 ssh_pkt_adddata(pkt, &value, 1);
7cca0d81 1857}
dacd8872 1858static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1859{
7cca0d81 1860 unsigned char x[4];
1861 PUT_32BIT(x, value);
dacd8872 1862 ssh_pkt_adddata(pkt, x, 4);
7cca0d81 1863}
dacd8872 1864static void ssh_pkt_addstring_start(struct Packet *pkt)
32874aea 1865{
dacd8872 1866 ssh_pkt_adduint32(pkt, 0);
ff3187f6 1867 pkt->savedpos = pkt->length;
7cca0d81 1868}
dacd8872 1869static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1870{
dacd8872 1871 ssh_pkt_adddata(pkt, data, strlen(data));
ff3187f6 1872 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1873}
dacd8872 1874static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1875{
dacd8872 1876 ssh_pkt_adddata(pkt, data, len);
ff3187f6 1877 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1878}
dacd8872 1879static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1880{
1881 ssh_pkt_addstring_start(pkt);
1882 ssh_pkt_addstring_str(pkt, data);
1883}
1884static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1885{
dacd8872 1886 int len = ssh1_bignum_length(b);
8a9977e5 1887 unsigned char *data = snewn(len, unsigned char);
dacd8872 1888 (void) ssh1_write_bignum(data, b);
1889 ssh_pkt_adddata(pkt, data, len);
1890 sfree(data);
7cca0d81 1891}
d8baa528 1892static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1893{
7cca0d81 1894 unsigned char *p;
32874aea 1895 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1896 p = snewn(n + 1, unsigned char);
7cca0d81 1897 p[0] = 0;
3709bfe9 1898 for (i = 1; i <= n; i++)
32874aea 1899 p[i] = bignum_byte(b, n - i);
7cca0d81 1900 i = 0;
32874aea 1901 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1902 i++;
1903 memmove(p, p + i, n + 1 - i);
1904 *len = n + 1 - i;
7cca0d81 1905 return p;
1906}
ff3187f6 1907static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1908{
7cca0d81 1909 unsigned char *p;
1910 int len;
1911 p = ssh2_mpint_fmt(b, &len);
dacd8872 1912 ssh_pkt_addstring_start(pkt);
1913 ssh_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1914 sfree(p);
7cca0d81 1915}
b185170a 1916
dacd8872 1917static struct Packet *ssh1_pkt_init(int pkt_type)
1918{
1919 struct Packet *pkt = ssh_new_packet();
1920 pkt->length = 4 + 8; /* space for length + max padding */
1921 ssh_pkt_addbyte(pkt, pkt_type);
1922 pkt->body = pkt->data + pkt->length;
1923 return pkt;
1924}
1925
1926/* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1927#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1928#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1929#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1930#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1931#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1932#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1933#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1934#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1935
1936static struct Packet *ssh2_pkt_init(int pkt_type)
1937{
1938 struct Packet *pkt = ssh_new_packet();
3d71de0b 1939 pkt->length = 5; /* space for packet length + padding length */
dacd8872 1940 pkt->forcepad = 0;
1941 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
3d71de0b 1942 pkt->body = pkt->data + pkt->length; /* after packet type */
dacd8872 1943 return pkt;
1944}
1945
b185170a 1946/*
2e85c969 1947 * Construct an SSH-2 final-form packet: compress it, encrypt it,
b185170a 1948 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1949 * pkt->data. Total length is returned.
b185170a 1950 */
ff3187f6 1951static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1952{
7cca0d81 1953 int cipherblk, maclen, padding, i;
7cca0d81 1954
a8327734 1955 if (ssh->logctx)
ff3187f6 1956 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
acab36bc 1957 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
dacd8872 1958 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1959 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
ff3187f6 1960 sfree(pkt->blanks); pkt->blanks = NULL;
1961 pkt->nblanks = 0;
00db133f 1962
7cca0d81 1963 /*
4ba9b64b 1964 * Compress packet payload.
1965 */
4ba9b64b 1966 {
1967 unsigned char *newpayload;
1968 int newlen;
51470298 1969 if (ssh->cscomp &&
ff3187f6 1970 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1971 pkt->length - 5,
51470298 1972 &newpayload, &newlen)) {
ff3187f6 1973 pkt->length = 5;
1974 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1975 sfree(newpayload);
4ba9b64b 1976 }
1977 }
1978
1979 /*
7cca0d81 1980 * Add padding. At least four bytes, and must also bring total
1981 * length (minus MAC) up to a multiple of the block size.
95d2d262 1982 * If pkt->forcepad is set, make sure the packet is at least that size
1983 * after padding.
7cca0d81 1984 */
51470298 1985 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1986 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1987 padding = 4;
95d2d262 1988 if (pkt->length + padding < pkt->forcepad)
1989 padding = pkt->forcepad - pkt->length;
32874aea 1990 padding +=
ff3187f6 1991 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
95d2d262 1992 assert(padding <= 255);
51470298 1993 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1994 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1995 pkt->data[4] = padding;
7cca0d81 1996 for (i = 0; i < padding; i++)
ff3187f6 1997 pkt->data[pkt->length + i] = random_byte();
1998 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1999 if (ssh->csmac)
ff3187f6 2000 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2001 pkt->length + padding,
51470298 2002 ssh->v2_outgoing_sequence);
2003 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2004
2005 if (ssh->cscipher)
371e569c 2006 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 2007 pkt->data, pkt->length + padding);
51470298 2008
9442dd57 2009 pkt->encrypted_len = pkt->length + padding;
2010
ff3187f6 2011 /* Ready-to-send packet starts at pkt->data. We return length. */
2012 return pkt->length + padding + maclen;
b185170a 2013}
2014
2015/*
590f6a5f 2016 * Routines called from the main SSH code to send packets. There
2017 * are quite a few of these, because we have two separate
2018 * mechanisms for delaying the sending of packets:
2019 *
2020 * - In order to send an IGNORE message and a password message in
2021 * a single fixed-length blob, we require the ability to
2022 * concatenate the encrypted forms of those two packets _into_ a
2023 * single blob and then pass it to our <network.h> transport
2024 * layer in one go. Hence, there's a deferment mechanism which
2025 * works after packet encryption.
2026 *
2027 * - In order to avoid sending any connection-layer messages
2028 * during repeat key exchange, we have to queue up any such
2029 * outgoing messages _before_ they are encrypted (and in
2030 * particular before they're allocated sequence numbers), and
2031 * then send them once we've finished.
2032 *
2033 * I call these mechanisms `defer' and `queue' respectively, so as
2034 * to distinguish them reasonably easily.
2035 *
2036 * The functions send_noqueue() and defer_noqueue() free the packet
2037 * structure they are passed. Every outgoing packet goes through
2038 * precisely one of these functions in its life; packets passed to
2039 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2040 * these or get queued, and then when the queue is later emptied
2041 * the packets are all passed to defer_noqueue().
97ab28d7 2042 *
2043 * When using a CBC-mode cipher, it's necessary to ensure that an
2044 * attacker can't provide data to be encrypted using an IV that they
2045 * know. We ensure this by prefixing each packet that might contain
2046 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2047 * mechanism, so in this case send_noqueue() ends up redirecting to
2048 * defer_noqueue(). If you don't like this inefficiency, don't use
2049 * CBC.
b185170a 2050 */
590f6a5f 2051
97ab28d7 2052static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2053static void ssh_pkt_defersend(Ssh);
2054
590f6a5f 2055/*
2e85c969 2056 * Send an SSH-2 packet immediately, without queuing or deferring.
590f6a5f 2057 */
2058static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 2059{
5471d09a 2060 int len;
2061 int backlog;
97ab28d7 2062 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2063 /* We need to send two packets, so use the deferral mechanism. */
2064 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2065 ssh_pkt_defersend(ssh);
2066 return;
2067 }
ff3187f6 2068 len = ssh2_pkt_construct(ssh, pkt);
bf8a49a1 2069 backlog = s_write(ssh, pkt->data, len);
5471d09a 2070 if (backlog > SSH_MAX_BACKLOG)
51470298 2071 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2072
2073 ssh->outgoing_data_size += pkt->encrypted_len;
2074 if (!ssh->kex_in_progress &&
d57f70af 2075 ssh->max_data_size != 0 &&
2076 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2077 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2078
ff3187f6 2079 ssh_free_packet(pkt);
b185170a 2080}
2081
2082/*
2e85c969 2083 * Defer an SSH-2 packet.
b185170a 2084 */
97ab28d7 2085static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
32874aea 2086{
97ab28d7 2087 int len;
2088 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
cf6ddb95 2089 ssh->deferred_len == 0 && !noignore &&
2090 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
97ab28d7 2091 /*
2092 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2093 * get encrypted with a known IV.
2094 */
2095 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
27311cc7 2096 ssh2_pkt_addstring_start(ipkt);
97ab28d7 2097 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2098 }
2099 len = ssh2_pkt_construct(ssh, pkt);
51470298 2100 if (ssh->deferred_len + len > ssh->deferred_size) {
2101 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 2102 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2103 ssh->deferred_size,
2104 unsigned char);
b185170a 2105 }
ff3187f6 2106 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 2107 ssh->deferred_len += len;
9442dd57 2108 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 2109 ssh_free_packet(pkt);
b185170a 2110}
2111
2112/*
2e85c969 2113 * Queue an SSH-2 packet.
590f6a5f 2114 */
2115static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2116{
2117 assert(ssh->queueing);
2118
2119 if (ssh->queuelen >= ssh->queuesize) {
2120 ssh->queuesize = ssh->queuelen + 32;
2121 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2122 }
2123
2124 ssh->queue[ssh->queuelen++] = pkt;
2125}
2126
2127/*
2128 * Either queue or send a packet, depending on whether queueing is
2129 * set.
2130 */
2131static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2132{
2133 if (ssh->queueing)
2134 ssh2_pkt_queue(ssh, pkt);
2135 else
2136 ssh2_pkt_send_noqueue(ssh, pkt);
2137}
2138
2139/*
2140 * Either queue or defer a packet, depending on whether queueing is
2141 * set.
2142 */
2143static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2144{
2145 if (ssh->queueing)
2146 ssh2_pkt_queue(ssh, pkt);
2147 else
97ab28d7 2148 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
590f6a5f 2149}
2150
2151/*
b185170a 2152 * Send the whole deferred data block constructed by
2e85c969 2153 * ssh2_pkt_defer() or SSH-1's defer_packet().
590f6a5f 2154 *
2155 * The expected use of the defer mechanism is that you call
2156 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2157 * not currently queueing, this simply sets up deferred_send_data
2158 * and then sends it. If we _are_ currently queueing, the calls to
2159 * ssh2_pkt_defer() put the deferred packets on to the queue
2160 * instead, and therefore ssh_pkt_defersend() has no deferred data
2161 * to send. Hence, there's no need to make it conditional on
2162 * ssh->queueing.
b185170a 2163 */
51470298 2164static void ssh_pkt_defersend(Ssh ssh)
32874aea 2165{
5471d09a 2166 int backlog;
bf8a49a1 2167 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
51470298 2168 ssh->deferred_len = ssh->deferred_size = 0;
2169 sfree(ssh->deferred_send_data);
2170 ssh->deferred_send_data = NULL;
5471d09a 2171 if (backlog > SSH_MAX_BACKLOG)
51470298 2172 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2173
2174 ssh->outgoing_data_size += ssh->deferred_data_size;
2175 if (!ssh->kex_in_progress &&
d57f70af 2176 ssh->max_data_size != 0 &&
2177 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2178 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2179 ssh->deferred_data_size = 0;
7cca0d81 2180}
2181
590f6a5f 2182/*
18524056 2183 * Send a packet whose length needs to be disguised (typically
2184 * passwords or keyboard-interactive responses).
2185 */
2186static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2187 int padsize)
2188{
2189#if 0
2190 if (0) {
2191 /*
2192 * The simplest way to do this is to adjust the
2193 * variable-length padding field in the outgoing packet.
2194 *
2195 * Currently compiled out, because some Cisco SSH servers
2196 * don't like excessively padded packets (bah, why's it
2197 * always Cisco?)
2198 */
2199 pkt->forcepad = padsize;
2200 ssh2_pkt_send(ssh, pkt);
2201 } else
2202#endif
2203 {
2204 /*
2205 * If we can't do that, however, an alternative approach is
2206 * to use the pkt_defer mechanism to bundle the packet
2207 * tightly together with an SSH_MSG_IGNORE such that their
2208 * combined length is a constant. So first we construct the
2209 * final form of this packet and defer its sending.
2210 */
2211 ssh2_pkt_defer(ssh, pkt);
2212
2213 /*
2214 * Now construct an SSH_MSG_IGNORE which includes a string
2215 * that's an exact multiple of the cipher block size. (If
2216 * the cipher is NULL so that the block size is
2217 * unavailable, we don't do this trick at all, because we
2218 * gain nothing by it.)
2219 */
cf6ddb95 2220 if (ssh->cscipher &&
2221 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
18524056 2222 int stringlen, i;
2223
2224 stringlen = (256 - ssh->deferred_len);
2225 stringlen += ssh->cscipher->blksize - 1;
2226 stringlen -= (stringlen % ssh->cscipher->blksize);
2227 if (ssh->cscomp) {
2228 /*
2229 * Temporarily disable actual compression, so we
2230 * can guarantee to get this string exactly the
2231 * length we want it. The compression-disabling
2232 * routine should return an integer indicating how
2233 * many bytes we should adjust our string length
2234 * by.
2235 */
2236 stringlen -=
2237 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2238 }
2239 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2240 ssh2_pkt_addstring_start(pkt);
2241 for (i = 0; i < stringlen; i++) {
2242 char c = (char) random_byte();
2243 ssh2_pkt_addstring_data(pkt, &c, 1);
2244 }
2245 ssh2_pkt_defer(ssh, pkt);
2246 }
2247 ssh_pkt_defersend(ssh);
2248 }
2249}
2250
2251/*
2e85c969 2252 * Send all queued SSH-2 packets. We send them by means of
590f6a5f 2253 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2254 * packets that needed to be lumped together.
2255 */
2256static void ssh2_pkt_queuesend(Ssh ssh)
2257{
2258 int i;
2259
2260 assert(!ssh->queueing);
2261
2262 for (i = 0; i < ssh->queuelen; i++)
97ab28d7 2263 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
590f6a5f 2264 ssh->queuelen = 0;
2265
2266 ssh_pkt_defersend(ssh);
2267}
2268
7cca0d81 2269#if 0
32874aea 2270void bndebug(char *string, Bignum b)
2271{
7cca0d81 2272 unsigned char *p;
2273 int i, len;
2274 p = ssh2_mpint_fmt(b, &len);
2275 debug(("%s", string));
2276 for (i = 0; i < len; i++)
32874aea 2277 debug((" %02x", p[i]));
765c4200 2278 debug(("\n"));
dcbde236 2279 sfree(p);
7cca0d81 2280}
2281#endif
2282
b672f405 2283static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
32874aea 2284{
7cca0d81 2285 unsigned char *p;
2286 int len;
2287 p = ssh2_mpint_fmt(b, &len);
b672f405 2288 hash_string(h, s, p, len);
dcbde236 2289 sfree(p);
7cca0d81 2290}
2291
2292/*
2e85c969 2293 * Packet decode functions for both SSH-1 and SSH-2.
7cca0d81 2294 */
ff3187f6 2295static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 2296{
7cca0d81 2297 unsigned long value;
ff3187f6 2298 if (pkt->length - pkt->savedpos < 4)
32874aea 2299 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2300 value = GET_32BIT(pkt->body + pkt->savedpos);
2301 pkt->savedpos += 4;
7cca0d81 2302 return value;
2303}
ff3187f6 2304static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 2305{
65a22376 2306 unsigned long value;
ff3187f6 2307 if (pkt->length - pkt->savedpos < 1)
32874aea 2308 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2309 value = pkt->body[pkt->savedpos] != 0;
2310 pkt->savedpos++;
65a22376 2311 return value;
2312}
ff3187f6 2313static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 2314{
57356d63 2315 int len;
7cca0d81 2316 *p = NULL;
45068b27 2317 *length = 0;
ff3187f6 2318 if (pkt->length - pkt->savedpos < 4)
32874aea 2319 return;
ff3187f6 2320 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 2321 if (len < 0)
2322 return;
2323 *length = len;
ff3187f6 2324 pkt->savedpos += 4;
2325 if (pkt->length - pkt->savedpos < *length)
32874aea 2326 return;
ff3187f6 2327 *p = (char *)(pkt->body + pkt->savedpos);
2328 pkt->savedpos += *length;
7cca0d81 2329}
ff3187f6 2330static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 2331{
ff3187f6 2332 if (pkt->length - pkt->savedpos < length)
0016d70b 2333 return NULL;
ff3187f6 2334 pkt->savedpos += length;
2335 return pkt->body + (pkt->savedpos - length);
0016d70b 2336}
ff3187f6 2337static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 2338 unsigned char **keystr)
2339{
2340 int j;
2341
ff3187f6 2342 j = makekey(pkt->body + pkt->savedpos,
2343 pkt->length - pkt->savedpos,
0016d70b 2344 key, keystr, 0);
2345
2346 if (j < 0)
2347 return FALSE;
2348
ff3187f6 2349 pkt->savedpos += j;
2350 assert(pkt->savedpos < pkt->length);
0016d70b 2351
2352 return TRUE;
2353}
ff3187f6 2354static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 2355{
2356 int j;
2357 Bignum b;
2358
ff3187f6 2359 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2360 pkt->length - pkt->savedpos, &b);
0016d70b 2361
2362 if (j < 0)
2363 return NULL;
2364
ff3187f6 2365 pkt->savedpos += j;
0016d70b 2366 return b;
2367}
ff3187f6 2368static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 2369{
7cca0d81 2370 char *p;
3709bfe9 2371 int length;
7cca0d81 2372 Bignum b;
2373
ff3187f6 2374 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 2375 if (!p)
32874aea 2376 return NULL;
ff3187f6 2377 if (p[0] & 0x80)
32874aea 2378 return NULL;
d8baa528 2379 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 2380 return b;
2381}
2382
7d503c31 2383/*
2e85c969 2384 * Helper function to add an SSH-2 signature blob to a packet.
1dd353b5 2385 * Expects to be shown the public key blob as well as the signature
2386 * blob. Normally works just like ssh2_pkt_addstring, but will
2387 * fiddle with the signature packet if necessary for
2388 * BUG_SSH2_RSA_PADDING.
2389 */
ff3187f6 2390static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2391 void *pkblob_v, int pkblob_len,
1dd353b5 2392 void *sigblob_v, int sigblob_len)
2393{
2394 unsigned char *pkblob = (unsigned char *)pkblob_v;
2395 unsigned char *sigblob = (unsigned char *)sigblob_v;
2396
2397 /* dmemdump(pkblob, pkblob_len); */
2398 /* dmemdump(sigblob, sigblob_len); */
2399
2400 /*
2401 * See if this is in fact an ssh-rsa signature and a buggy
2402 * server; otherwise we can just do this the easy way.
2403 */
51470298 2404 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 2405 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2406 int pos, len, siglen;
2407
2408 /*
2409 * Find the byte length of the modulus.
2410 */
2411
2412 pos = 4+7; /* skip over "ssh-rsa" */
2413 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2414 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2415 pos += 4; /* find modulus itself */
2416 while (len > 0 && pkblob[pos] == 0)
2417 len--, pos++;
2418 /* debug(("modulus length is %d\n", len)); */
2419
2420 /*
2421 * Now find the signature integer.
2422 */
2423 pos = 4+7; /* skip over "ssh-rsa" */
2424 siglen = GET_32BIT(sigblob+pos);
2425 /* debug(("signature length is %d\n", siglen)); */
2426
2427 if (len != siglen) {
2428 unsigned char newlen[4];
ff3187f6 2429 ssh2_pkt_addstring_start(pkt);
2430 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2431 /* dmemdump(sigblob, pos); */
2432 pos += 4; /* point to start of actual sig */
2433 PUT_32BIT(newlen, len);
ff3187f6 2434 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2435 /* dmemdump(newlen, 4); */
2436 newlen[0] = 0;
2437 while (len-- > siglen) {
ff3187f6 2438 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2439 /* dmemdump(newlen, 1); */
2440 }
ff3187f6 2441 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2442 /* dmemdump(sigblob+pos, siglen); */
2443 return;
2444 }
2445
2446 /* Otherwise fall through and do it the easy way. */
2447 }
2448
ff3187f6 2449 ssh2_pkt_addstring_start(pkt);
2450 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2451}
2452
2453/*
7d503c31 2454 * Examine the remote side's version string and compare it against
2455 * a list of known buggy implementations.
2456 */
51470298 2457static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2458{
2459 char *imp; /* pointer to implementation part */
7d503c31 2460 imp = vstring;
2461 imp += strcspn(imp, "-");
bd358db1 2462 if (*imp) imp++;
7d503c31 2463 imp += strcspn(imp, "-");
bd358db1 2464 if (*imp) imp++;
7d503c31 2465
51470298 2466 ssh->remote_bugs = 0;
7d503c31 2467
bf982899 2468 /*
2469 * General notes on server version strings:
2470 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2471 * here -- in particular, we've heard of one that's perfectly happy
2472 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2473 * so we can't distinguish them.
2474 */
4a693cfc 2475 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2476 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2c9c6388 2477 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2478 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2479 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2480 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2481 /*
2482 * These versions don't support SSH1_MSG_IGNORE, so we have
2483 * to use a different defence against password length
2484 * sniffing.
2485 */
51470298 2486 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2e85c969 2487 logevent("We believe remote version has SSH-1 ignore bug");
7d503c31 2488 }
2489
4a693cfc 2490 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2491 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
46ac09aa 2492 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2493 /*
2494 * These versions need a plain password sent; they can't
2495 * handle having a null and a random length of data after
2496 * the password.
2497 */
51470298 2498 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2e85c969 2499 logevent("We believe remote version needs a plain SSH-1 password");
bd358db1 2500 }
2501
4a693cfc 2502 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2503 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2c9c6388 2504 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2505 /*
2506 * These versions apparently have no clue whatever about
2507 * RSA authentication and will panic and die if they see
2508 * an AUTH_RSA message.
2509 */
51470298 2510 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
19f47a7d 2511 logevent("We believe remote version can't handle SSH-1 RSA authentication");
0df73905 2512 }
2513
4a693cfc 2514 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2515 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
b9f387af 2516 !wc_match("* VShell", imp) &&
831301f6 2517 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2518 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2519 wc_match("2.1 *", imp)))) {
32874aea 2520 /*
2521 * These versions have the HMAC bug.
2522 */
51470298 2523 ssh->remote_bugs |= BUG_SSH2_HMAC;
2e85c969 2524 logevent("We believe remote version has SSH-2 HMAC bug");
7d503c31 2525 }
1dd353b5 2526
4a693cfc 2527 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2528 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
b9f387af 2529 !wc_match("* VShell", imp) &&
2856a1b9 2530 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2531 /*
2532 * These versions have the key-derivation bug (failing to
2533 * include the literal shared secret in the hashes that
2534 * generate the keys).
2535 */
51470298 2536 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2e85c969 2537 logevent("We believe remote version has SSH-2 key-derivation bug");
088bde77 2538 }
2539
4a693cfc 2540 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2541 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
831301f6 2542 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2543 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2544 /*
2e85c969 2545 * These versions have the SSH-2 RSA padding bug.
1dd353b5 2546 */
51470298 2547 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2e85c969 2548 logevent("We believe remote version has SSH-2 RSA padding bug");
1dd353b5 2549 }
8e975795 2550
4a693cfc 2551 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2552 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
dda87a28 2553 wc_match("OpenSSH_2.[0-2]*", imp))) {
2554 /*
2e85c969 2555 * These versions have the SSH-2 session-ID bug in
dda87a28 2556 * public-key authentication.
2557 */
2558 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2e85c969 2559 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
dda87a28 2560 }
f382c87d 2561
4a693cfc 2562 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2563 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
39b8712f 2564 (wc_match("DigiSSH_2.0", imp) ||
2565 wc_match("OpenSSH_2.[0-4]*", imp) ||
e12d95a5 2566 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2567 wc_match("Sun_SSH_1.0", imp) ||
f4275b53 2568 wc_match("Sun_SSH_1.0.1", imp) ||
96bd26de 2569 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2570 wc_match("WeOnlyDo-*", imp)))) {
f382c87d 2571 /*
2e85c969 2572 * These versions have the SSH-2 rekey bug.
f382c87d 2573 */
2574 ssh->remote_bugs |= BUG_SSH2_REKEY;
2e85c969 2575 logevent("We believe remote version has SSH-2 rekey bug");
f382c87d 2576 }
c9739dba 2577
4a693cfc 2578 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2579 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
5ca836f2 2580 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2581 wc_match("1.36 sshlib: GlobalScape", imp)))) {
c9739dba 2582 /*
2583 * This version ignores our makpkt and needs to be throttled.
2584 */
2585 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2586 logevent("We believe remote version ignores SSH-2 maximum packet size");
2587 }
cf6ddb95 2588
4a693cfc 2589 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
cf6ddb95 2590 /*
2591 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2592 * none detected automatically.
2593 */
2594 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2595 logevent("We believe remote version has SSH-2 ignore bug");
2596 }
2e0aae4f 2597
2598 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2599 /*
2600 * Servers that don't support our winadj request for one
2601 * reason or another. Currently, none detected automatically.
2602 */
2603 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2604 logevent("We believe remote version has winadj bug");
2605 }
7d503c31 2606}
2607
d38d6a1f 2608/*
2609 * The `software version' part of an SSH version string is required
2610 * to contain no spaces or minus signs.
2611 */
2612static void ssh_fix_verstring(char *str)
2613{
2614 /* Eat "SSH-<protoversion>-". */
2615 assert(*str == 'S'); str++;
2616 assert(*str == 'S'); str++;
2617 assert(*str == 'H'); str++;
2618 assert(*str == '-'); str++;
2619 while (*str && *str != '-') str++;
2620 assert(*str == '-'); str++;
2621
2622 /* Convert minus signs and spaces in the remaining string into
2623 * underscores. */
2624 while (*str) {
2625 if (*str == '-' || *str == ' ')
2626 *str = '_';
2627 str++;
2628 }
2629}
2630
1fcd0d98 2631/*
2632 * Send an appropriate SSH version string.
2633 */
2634static void ssh_send_verstring(Ssh ssh, char *svers)
2635{
2636 char *verstring;
2637
2638 if (ssh->version == 2) {
2639 /*
2640 * Construct a v2 version string.
2641 */
2642 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2643 } else {
2644 /*
2645 * Construct a v1 version string.
2646 */
2647 verstring = dupprintf("SSH-%s-%s\012",
2648 (ssh_versioncmp(svers, "1.5") <= 0 ?
2649 svers : "1.5"),
2650 sshver);
2651 }
2652
2653 ssh_fix_verstring(verstring);
2654
2655 if (ssh->version == 2) {
2656 size_t len;
2657 /*
2658 * Record our version string.
2659 */
2660 len = strcspn(verstring, "\015\012");
2661 ssh->v_c = snewn(len + 1, char);
2662 memcpy(ssh->v_c, verstring, len);
2663 ssh->v_c[len] = 0;
2664 }
2665
2666 logeventf(ssh, "We claim version: %.*s",
2667 strcspn(verstring, "\015\012"), verstring);
2668 s_write(ssh, verstring, strlen(verstring));
2669 sfree(verstring);
2670}
2671
51470298 2672static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2673{
51470298 2674 struct do_ssh_init_state {
30919997 2675 int crLine;
51470298 2676 int vslen;
2677 char version[10];
2678 char *vstring;
2679 int vstrsize;
2680 int i;
2681 int proto1, proto2;
2682 };
2683 crState(do_ssh_init_state);
30919997 2684
2685 crBeginState;
8df7a775 2686
8c1835c0 2687 /* Search for a line beginning with the string "SSH-" in the input. */
2688 for (;;) {
2689 if (c != 'S') goto no;
2690 crReturn(1);
2691 if (c != 'S') goto no;
2692 crReturn(1);
2693 if (c != 'H') goto no;
2694 crReturn(1);
2695 if (c != '-') goto no;
2696 break;
2697 no:
2698 while (c != '\012')
2699 crReturn(1);
2700 crReturn(1);
374330e2 2701 }
8df7a775 2702
51470298 2703 s->vstrsize = 16;
3d88e64d 2704 s->vstring = snewn(s->vstrsize, char);
51470298 2705 strcpy(s->vstring, "SSH-");
2706 s->vslen = 4;
2707 s->i = 0;
374330e2 2708 while (1) {
8df7a775 2709 crReturn(1); /* get another char */
51470298 2710 if (s->vslen >= s->vstrsize - 1) {
2711 s->vstrsize += 16;
3d88e64d 2712 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2713 }
51470298 2714 s->vstring[s->vslen++] = c;
2715 if (s->i >= 0) {
374330e2 2716 if (c == '-') {
51470298 2717 s->version[s->i] = '\0';
2718 s->i = -1;
2719 } else if (s->i < sizeof(s->version) - 1)
2720 s->version[s->i++] = c;
c4ffc4d0 2721 } else if (c == '\012')
374330e2 2722 break;
2723 }
2724
51470298 2725 ssh->agentfwd_enabled = FALSE;
2726 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2727
51470298 2728 s->vstring[s->vslen] = 0;
a7d4653a 2729 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
fb983202 2730 logeventf(ssh, "Server version: %s", s->vstring);
51470298 2731 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2732
adf799dd 2733 /*
38d228a2 2734 * Decide which SSH protocol version to support.
adf799dd 2735 */
38d228a2 2736
2737 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2738 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2739 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2740 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2741
4a693cfc 2742 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
6b5cf8b4 2743 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2744 crStop(0);
38d228a2 2745 }
4a693cfc 2746 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
6b5cf8b4 2747 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2748 crStop(0);
38d228a2 2749 }
2750
4a693cfc 2751 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
1fcd0d98 2752 ssh->version = 2;
2753 else
2754 ssh->version = 1;
d38d6a1f 2755
2756 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2757
1fcd0d98 2758 /* Send the version string, if we haven't already */
4a693cfc 2759 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
1fcd0d98 2760 ssh_send_verstring(ssh, s->version);
2761
2762 if (ssh->version == 2) {
2763 size_t len;
2764 /*
2765 * Record their version string.
2766 */
2767 len = strcspn(s->vstring, "\015\012");
2768 ssh->v_s = snewn(len + 1, char);
2769 memcpy(ssh->v_s, s->vstring, len);
2770 ssh->v_s[len] = 0;
2771
2772 /*
2773 * Initialise SSH-2 protocol.
2774 */
2775 ssh->protocol = ssh2_protocol;
2776 ssh2_protocol_setup(ssh);
2777 ssh->s_rdpkt = ssh2_rdpkt;
2778 } else {
2779 /*
2780 * Initialise SSH-1 protocol.
2781 */
2782 ssh->protocol = ssh1_protocol;
2783 ssh1_protocol_setup(ssh);
2784 ssh->s_rdpkt = ssh1_rdpkt;
2785 }
2786 if (ssh->version == 2)
2787 do_ssh2_transport(ssh, NULL, -1, NULL);
2788
125105d1 2789 update_specials_menu(ssh->frontend);
51470298 2790 ssh->state = SSH_STATE_BEFORE_SIZE;
4a693cfc 2791 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
8df7a775 2792
51470298 2793 sfree(s->vstring);
50526e47 2794
8df7a775 2795 crFinish(0);
2796}
2797
3d9449a1 2798static void ssh_process_incoming_data(Ssh ssh,
2799 unsigned char **data, int *datalen)
2800{
bf8a49a1 2801 struct Packet *pktin;
2802
2803 pktin = ssh->s_rdpkt(ssh, data, datalen);
3d9449a1 2804 if (pktin) {
2805 ssh->protocol(ssh, NULL, 0, pktin);
2806 ssh_free_packet(pktin);
2807 }
2808}
2809
2810static void ssh_queue_incoming_data(Ssh ssh,
2811 unsigned char **data, int *datalen)
2812{
2813 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2814 *data += *datalen;
2815 *datalen = 0;
2816}
2817
2818static void ssh_process_queued_incoming_data(Ssh ssh)
2819{
2820 void *vdata;
2821 unsigned char *data;
2822 int len, origlen;
2823
2824 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2825 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2826 data = vdata;
2827 origlen = len;
2828
2829 while (!ssh->frozen && len > 0)
2830 ssh_process_incoming_data(ssh, &data, &len);
2831
2832 if (origlen > len)
2833 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2834 }
2835}
2836
2837static void ssh_set_frozen(Ssh ssh, int frozen)
2838{
a5a6f839 2839 if (ssh->s)
2840 sk_set_frozen(ssh->s, frozen);
3d9449a1 2841 ssh->frozen = frozen;
2842}
2843
51470298 2844static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2845{
bf8a49a1 2846 /* Log raw data, if we're in that mode. */
ff05dfef 2847 if (ssh->logctx)
2848 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
0d13bfcd 2849 0, NULL, NULL);
bf8a49a1 2850
51470298 2851 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2852
2853 /*
2854 * To begin with, feed the characters one by one to the
2855 * protocol initialisation / selection function do_ssh_init().
2856 * When that returns 0, we're done with the initial greeting
2857 * exchange and can move on to packet discipline.
2858 */
2859 while (1) {
51470298 2860 int ret; /* need not be kept across crReturn */
8df7a775 2861 if (datalen == 0)
2862 crReturnV; /* more data please */
51470298 2863 ret = do_ssh_init(ssh, *data);
32874aea 2864 data++;
2865 datalen--;
8df7a775 2866 if (ret == 0)
2867 break;
2868 }
2869
2870 /*
2871 * We emerge from that loop when the initial negotiation is
2872 * over and we have selected an s_rdpkt function. Now pass
2873 * everything to s_rdpkt, and then pass the resulting packets
2874 * to the proper protocol handler.
2875 */
3d9449a1 2876
8df7a775 2877 while (1) {
e375106c 2878 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2879 if (ssh->frozen) {
3d9449a1 2880 ssh_queue_incoming_data(ssh, &data, &datalen);
e375106c 2881 /* This uses up all data and cannot cause anything interesting
2882 * to happen; indeed, for anything to happen at all, we must
2883 * return, so break out. */
2884 break;
2885 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2886 /* This uses up some or all data, and may freeze the
2887 * session. */
2888 ssh_process_queued_incoming_data(ssh);
2889 } else {
2890 /* This uses up some or all data, and may freeze the
2891 * session. */
2892 ssh_process_incoming_data(ssh, &data, &datalen);
2893 }
2894 /* FIXME this is probably EBW. */
ff3187f6 2895 if (ssh->state == SSH_STATE_CLOSED)
2896 return;
8df7a775 2897 }
e375106c 2898 /* We're out of data. Go and get some more. */
8df7a775 2899 crReturnV;
2900 }
2901 crFinishV;
2902}
2903
ac934965 2904static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2905{
80ffa58b 2906 int ret = 0;
36f94d1f 2907 struct ssh_channel *c;
2908
51470298 2909 ssh->state = SSH_STATE_CLOSED;
ecbb0000 2910 expire_timer_context(ssh);
51470298 2911 if (ssh->s) {
2912 sk_close(ssh->s);
2913 ssh->s = NULL;
ac934965 2914 if (notify_exit)
2915 notify_remote_exit(ssh->frontend);
2916 else
2917 ret = 1;
f3ab576e 2918 }
36f94d1f 2919 /*
80ffa58b 2920 * Now we must shut down any port- and X-forwarded channels going
36f94d1f 2921 * through this connection.
2922 */
74a98066 2923 if (ssh->channels) {
80ffa58b 2924 while (NULL != (c = index234(ssh->channels, 0))) {
74a98066 2925 switch (c->type) {
2926 case CHAN_X11:
2927 x11_close(c->u.x11.s);
2928 break;
2929 case CHAN_SOCKDATA:
409eca86 2930 case CHAN_SOCKDATA_DORMANT:
74a98066 2931 pfd_close(c->u.pfd.s);
2932 break;
2933 }
80ffa58b 2934 del234(ssh->channels, c); /* moving next one to index 0 */
74a98066 2935 if (ssh->version == 2)
2936 bufchain_clear(&c->v.v2.outbuffer);
2937 sfree(c);
36f94d1f 2938 }
36f94d1f 2939 }
f8c9f9df 2940 /*
2941 * Go through port-forwardings, and close any associated
2942 * listening sockets.
2943 */
2944 if (ssh->portfwds) {
2945 struct ssh_portfwd *pf;
2946 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2947 /* Dispose of any listening socket. */
2948 if (pf->local)
2949 pfd_terminate(pf->local);
2950 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2951 free_portfwd(pf);
2952 }
b72bdf11 2953 freetree234(ssh->portfwds);
2954 ssh->portfwds = NULL;
f8c9f9df 2955 }
ac934965 2956
2957 return ret;
36f94d1f 2958}
2959
7555d6a5 2960static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2961 const char *error_msg, int error_code)
2962{
2963 Ssh ssh = (Ssh) plug;
2964 char addrbuf[256], *msg;
2965
2966 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2967
2968 if (type == 0)
2969 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2970 else
2971 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2972
2973 logevent(msg);
fb983202 2974 sfree(msg);
7555d6a5 2975}
2976
cbe2d68f 2977static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2978 int calling_back)
2979{
2980 Ssh ssh = (Ssh) plug;
ac934965 2981 int need_notify = ssh_do_close(ssh, FALSE);
2982
9e296bfa 2983 if (!error_msg) {
2984 if (!ssh->close_expected)
2985 error_msg = "Server unexpectedly closed network connection";
2986 else
2987 error_msg = "Server closed network connection";
ac934965 2988 }
2989
d051d1b4 2990 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2991 ssh->exitcode = 0;
2992
2425184b 2993 if (need_notify)
2994 notify_remote_exit(ssh->frontend);
2995
9e296bfa 2996 if (error_msg)
247308b5 2997 logevent(error_msg);
9e296bfa 2998 if (!ssh->close_expected || !ssh->clean_exit)
971bcc0a 2999 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 3000 return 0;
3001}
3002
32874aea 3003static int ssh_receive(Plug plug, int urgent, char *data, int len)
3004{
51470298 3005 Ssh ssh = (Ssh) plug;
d8baa528 3006 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 3007 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 3008 ssh_do_close(ssh, TRUE);
32874aea 3009 return 0;
3257deae 3010 }
fef97f43 3011 return 1;
374330e2 3012}
3013
5471d09a 3014static void ssh_sent(Plug plug, int bufsize)
3015{
51470298 3016 Ssh ssh = (Ssh) plug;
5471d09a 3017 /*
3018 * If the send backlog on the SSH socket itself clears, we
3019 * should unthrottle the whole world if it was throttled.
3020 */
3021 if (bufsize < SSH_MAX_BACKLOG)
51470298 3022 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 3023}
3024
fb09bf1c 3025/*
8df7a775 3026 * Connect to specified host and port.
3027 * Returns an error message, or NULL on success.
6e1ebb76 3028 * Also places the canonical host name into `realhost'. It must be
3029 * freed by the caller.
8df7a775 3030 */
cbe2d68f 3031static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 3032 char **realhost, int nodelay, int keepalive)
8df7a775 3033{
51470298 3034 static const struct plug_function_table fn_table = {
7555d6a5 3035 ssh_log,
7e78000d 3036 ssh_closing,
5471d09a 3037 ssh_receive,
3038 ssh_sent,
3039 NULL
51470298 3040 };
7e78000d 3041
8df7a775 3042 SockAddr addr;
cbe2d68f 3043 const char *err;
4a693cfc 3044 char *loghost;
3045 int addressfamily, sshprot;
3046
3047 loghost = conf_get_str(ssh->conf, CONF_loghost);
3048 if (*loghost) {
881da168 3049 char *colon;
8df7a775 3050
4a693cfc 3051 ssh->savedhost = dupstr(loghost);
881da168 3052 ssh->savedport = 22; /* default ssh port */
3053
3054 /*
3055 * A colon suffix on savedhost also lets us affect
3056 * savedport.
3057 *
3058 * (FIXME: do something about IPv6 address literals here.)
3059 */
3060 colon = strrchr(ssh->savedhost, ':');
3061 if (colon) {
3062 *colon++ = '\0';
3063 if (*colon)
3064 ssh->savedport = atoi(colon);
3065 }
3066 } else {
3067 ssh->savedhost = dupstr(host);
3068 if (port < 0)
3069 port = 22; /* default ssh port */
3070 ssh->savedport = port;
3071 }
8df7a775 3072
3073 /*
3074 * Try to find host.
3075 */
4a693cfc 3076 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
05581745 3077 logeventf(ssh, "Looking up host \"%s\"%s", host,
4a693cfc 3078 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3079 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3080 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
170c1e6e 3081 if ((err = sk_addr_error(addr)) != NULL) {
3082 sk_addr_free(addr);
8df7a775 3083 return err;
170c1e6e 3084 }
42af6a67 3085 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
8df7a775 3086
8df7a775 3087 /*
3088 * Open socket.
3089 */
51470298 3090 ssh->fn = &fn_table;
e8fa8f62 3091 ssh->s = new_connection(addr, *realhost, port,
4a693cfc 3092 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
70e5d0fd 3093 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 3094 ssh->s = NULL;
39934deb 3095 notify_remote_exit(ssh->frontend);
8df7a775 3096 return err;
67c4ba2e 3097 }
8df7a775 3098
ff05dfef 3099 /*
3100 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3101 * send the version string too.
3102 */
4a693cfc 3103 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3104 if (sshprot == 0)
ff05dfef 3105 ssh->version = 1;
4a693cfc 3106 if (sshprot == 3) {
ff05dfef 3107 ssh->version = 2;
3108 ssh_send_verstring(ssh, NULL);
3109 }
3110
881da168 3111 /*
3112 * loghost, if configured, overrides realhost.
3113 */
4a693cfc 3114 if (*loghost) {
881da168 3115 sfree(*realhost);
4a693cfc 3116 *realhost = dupstr(loghost);
881da168 3117 }
3118
8df7a775 3119 return NULL;
3120}
3121
3122/*
5471d09a 3123 * Throttle or unthrottle the SSH connection.
3124 */
ff68564b 3125static void ssh_throttle_conn(Ssh ssh, int adjust)
5471d09a 3126{
ff68564b 3127 int old_count = ssh->conn_throttle_count;
3128 ssh->conn_throttle_count += adjust;
3129 assert(ssh->conn_throttle_count >= 0);
3130 if (ssh->conn_throttle_count && !old_count) {
3d9449a1 3131 ssh_set_frozen(ssh, 1);
ff68564b 3132 } else if (!ssh->conn_throttle_count && old_count) {
3d9449a1 3133 ssh_set_frozen(ssh, 0);
5471d09a 3134 }
3135}
3136
3137/*
3138 * Throttle or unthrottle _all_ local data streams (for when sends
3139 * on the SSH connection itself back up).
3140 */
51470298 3141static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 3142{
3143 int i;
3144 struct ssh_channel *c;
3145
51470298 3146 if (enable == ssh->throttled_all)
5471d09a 3147 return;
51470298 3148 ssh->throttled_all = enable;
3149 ssh->overall_bufsize = bufsize;
3150 if (!ssh->channels)
5471d09a 3151 return;
51470298 3152 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 3153 switch (c->type) {
3154 case CHAN_MAINSESSION:
3155 /*
3156 * This is treated separately, outside the switch.
3157 */
3158 break;
3159 case CHAN_X11:
3160 x11_override_throttle(c->u.x11.s, enable);
3161 break;
3162 case CHAN_AGENT:
3163 /* Agent channels require no buffer management. */
3164 break;
3165 case CHAN_SOCKDATA:
36f94d1f 3166 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 3167 break;
3168 }
3169 }
3170}
3171
f11d78f2 3172static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 3173{
3174 Ssh ssh = (Ssh) sshv;
3175
3176 ssh->agent_response = reply;
3177 ssh->agent_response_len = replylen;
3178
3179 if (ssh->version == 1)
ff3187f6 3180 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 3181 else
ff3187f6 3182 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 3183}
3184
3d9449a1 3185static void ssh_dialog_callback(void *sshv, int ret)
3186{
3187 Ssh ssh = (Ssh) sshv;
3188
3189 ssh->user_response = ret;
3190
3191 if (ssh->version == 1)
3192 do_ssh1_login(ssh, NULL, -1, NULL);
3193 else
3194 do_ssh2_transport(ssh, NULL, -1, NULL);
3195
3196 /*
3197 * This may have unfrozen the SSH connection, so do a
3198 * queued-data run.
3199 */
3200 ssh_process_queued_incoming_data(ssh);
3201}
3202
f11d78f2 3203static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 3204{
3205 struct ssh_channel *c = (struct ssh_channel *)cv;
3206 Ssh ssh = c->ssh;
3207 void *sentreply = reply;
3208
3209 if (!sentreply) {
3210 /* Fake SSH_AGENT_FAILURE. */
3211 sentreply = "\0\0\0\1\5";
3212 replylen = 5;
3213 }
3214 if (ssh->version == 2) {
3215 ssh2_add_channel_data(c, sentreply, replylen);
3216 ssh2_try_send(c);
3217 } else {
3218 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3219 PKT_INT, c->remoteid,
3220 PKT_INT, replylen,
a2724fba 3221 PKTT_DATA,
839f10db 3222 PKT_DATA, sentreply, replylen,
9a10ecf4 3223 PKTT_OTHER,
839f10db 3224 PKT_END);
3225 }
3226 if (reply)
3227 sfree(reply);
3228}
3229
0405e71f 3230/*
9e296bfa 3231 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3232 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3233 * => log `wire_reason'.
3234 */
3235static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3236 int code, int clean_exit)
3237{
3238 char *error;
3239 if (!client_reason)
3240 client_reason = wire_reason;
3241 if (client_reason)
3242 error = dupprintf("Disconnected: %s", client_reason);
3243 else
3244 error = dupstr("Disconnected");
3245 if (wire_reason) {
3246 if (ssh->version == 1) {
3247 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3248 PKT_END);
3249 } else if (ssh->version == 2) {
3250 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3251 ssh2_pkt_adduint32(pktout, code);
3252 ssh2_pkt_addstring(pktout, wire_reason);
3253 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3254 ssh2_pkt_send_noqueue(ssh, pktout);
3255 }
3256 }
3257 ssh->close_expected = TRUE;
3258 ssh->clean_exit = clean_exit;
3259 ssh_closing((Plug)ssh, error, 0, 0);
3260 sfree(error);
3261}
3262
3263/*
fb09bf1c 3264 * Handle the key exchange and user authentication phases.
3265 */
ff3187f6 3266static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3267 struct Packet *pktin)
fb09bf1c 3268{
0016d70b 3269 int i, j, ret;
3270 unsigned char cookie[8], *ptr;
374330e2 3271 struct RSAKey servkey, hostkey;
3272 struct MD5Context md5c;
51470298 3273 struct do_ssh1_login_state {
30919997 3274 int crLine;
51470298 3275 int len;
3276 unsigned char *rsabuf, *keystr1, *keystr2;
3277 unsigned long supported_ciphers_mask, supported_auths_mask;
3278 int tried_publickey, tried_agent;
3279 int tis_auth_refused, ccard_auth_refused;
3280 unsigned char session_id[16];
3281 int cipher_type;
51470298 3282 void *publickey_blob;
3283 int publickey_bloblen;
edd0cb8a 3284 char *publickey_comment;
3285 int publickey_encrypted;
3286 prompts_t *cur_prompt;
51470298 3287 char c;
3288 int pwpkt_type;
3289 unsigned char request[5], *response, *p;
3290 int responselen;
3291 int keyi, nkeys;
3292 int authed;
3293 struct RSAKey key;
3294 Bignum challenge;
3295 char *commentp;
3296 int commentlen;
3d9449a1 3297 int dlgret;
4a693cfc 3298 Filename *keyfile;
51470298 3299 };
3300 crState(do_ssh1_login_state);
3301
30919997 3302 crBeginState;
374330e2 3303
ff3187f6 3304 if (!pktin)
3305 crWaitUntil(pktin);
374330e2 3306
ff3187f6 3307 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 3308 bombout(("Public key packet not received"));
7ffdbc1a 3309 crStop(0);
8d5de777 3310 }
374330e2 3311
c5e9c988 3312 logevent("Received public keys");
374330e2 3313
ff3187f6 3314 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 3315 if (!ptr) {
2e85c969 3316 bombout(("SSH-1 public key packet stopped before random cookie"));
0016d70b 3317 crStop(0);
3318 }
3319 memcpy(cookie, ptr, 8);
374330e2 3320
ff3187f6 3321 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3322 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2e85c969 3323 bombout(("Failed to read SSH-1 public keys from public key packet"));
0016d70b 3324 crStop(0);
3325 }
374330e2 3326
c5e9c988 3327 /*
1c2a93c4 3328 * Log the host key fingerprint.
c5e9c988 3329 */
c5e9c988 3330 {
3331 char logmsg[80];
1c2a93c4 3332 logevent("Host key fingerprint is:");
c5e9c988 3333 strcpy(logmsg, " ");
32874aea 3334 hostkey.comment = NULL;
3335 rsa_fingerprint(logmsg + strlen(logmsg),
3336 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 3337 logevent(logmsg);
3338 }
3339
ff3187f6 3340 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3341 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3342 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
d5b2c841 3343 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3344 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
bea1ef5f 3345
51470298 3346 ssh->v1_local_protoflags =
3347 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3348 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 3349
c5e9c988 3350 MD5Init(&md5c);
51470298 3351 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3352 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 3353 MD5Update(&md5c, cookie, 8);
51470298 3354 MD5Final(s->session_id, &md5c);
374330e2 3355
32874aea 3356 for (i = 0; i < 32; i++)
51470298 3357 ssh->session_key[i] = random_byte();
374330e2 3358
0016d70b 3359 /*
3360 * Verify that the `bits' and `bytes' parameters match.
3361 */
3362 if (hostkey.bits > hostkey.bytes * 8 ||
3363 servkey.bits > servkey.bytes * 8) {
2e85c969 3364 bombout(("SSH-1 public keys were badly formatted"));
0016d70b 3365 crStop(0);
3366 }
3367
51470298 3368 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 3369
3d88e64d 3370 s->rsabuf = snewn(s->len, unsigned char);
374330e2 3371
89ee5268 3372 /*
3373 * Verify the host key.
3374 */
3375 {
32874aea 3376 /*
3377 * First format the key into a string.
3378 */
3379 int len = rsastr_len(&hostkey);
3380 char fingerprint[100];
3d88e64d 3381 char *keystr = snewn(len, char);
32874aea 3382 rsastr_fmt(keystr, &hostkey);
3383 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3d9449a1 3384
3385 ssh_set_frozen(ssh, 1);
3386 s->dlgret = verify_ssh_host_key(ssh->frontend,
3387 ssh->savedhost, ssh->savedport,
3388 "rsa", keystr, fingerprint,
3389 ssh_dialog_callback, ssh);
32874aea 3390 sfree(keystr);
3d9449a1 3391 if (s->dlgret < 0) {
3392 do {
3393 crReturn(0);
3394 if (pktin) {
3395 bombout(("Unexpected data from server while waiting"
3396 " for user host key response"));
3397 crStop(0);
3398 }
3399 } while (pktin || inlen > 0);
3400 s->dlgret = ssh->user_response;
3401 }
3402 ssh_set_frozen(ssh, 0);
3403
3404 if (s->dlgret == 0) {
9e296bfa 3405 ssh_disconnect(ssh, "User aborted at host key verification",
3406 NULL, 0, TRUE);
2b3f6c19 3407 crStop(0);
3d9449a1 3408 }
32874aea 3409 }
3410
3411 for (i = 0; i < 32; i++) {
51470298 3412 s->rsabuf[i] = ssh->session_key[i];
374330e2 3413 if (i < 16)
51470298 3414 s->rsabuf[i] ^= s->session_id[i];
374330e2 3415 }
3416
3417 if (hostkey.bytes > servkey.bytes) {
0016d70b 3418 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3419 if (ret)
3420 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 3421 } else {
0016d70b 3422 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3423 if (ret)
3424 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3425 }
3426 if (!ret) {
2e85c969 3427 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
0016d70b 3428 crStop(0);
374330e2 3429 }
3430
c5e9c988 3431 logevent("Encrypted session key");
3432
ca20bfcf 3433 {
3434 int cipher_chosen = 0, warn = 0;
3435 char *cipher_string = NULL;
51470298 3436 int i;
ca20bfcf 3437 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4a693cfc 3438 int next_cipher = conf_get_int_int(ssh->conf,
3439 CONF_ssh_cipherlist, i);
ca20bfcf 3440 if (next_cipher == CIPHER_WARN) {
3441 /* If/when we choose a cipher, warn about it */
3442 warn = 1;
3443 } else if (next_cipher == CIPHER_AES) {
3444 /* XXX Probably don't need to mention this. */
2e85c969 3445 logevent("AES not supported in SSH-1, skipping");
ca20bfcf 3446 } else {
3447 switch (next_cipher) {
51470298 3448 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 3449 cipher_string = "3DES"; break;
51470298 3450 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 3451 cipher_string = "Blowfish"; break;
51470298 3452 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 3453 cipher_string = "single-DES"; break;
3454 }
51470298 3455 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 3456 cipher_chosen = 1;
3457 }
3458 }
3459 if (!cipher_chosen) {
51470298 3460 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2e85c969 3461 bombout(("Server violates SSH-1 protocol by not "
ca20bfcf 3462 "supporting 3DES encryption"));
3463 else
3464 /* shouldn't happen */
6b5cf8b4 3465 bombout(("No supported ciphers found"));
7ffdbc1a 3466 crStop(0);
a99a05c0 3467 }
ca20bfcf 3468
3469 /* Warn about chosen cipher if necessary. */
bb348ab1 3470 if (warn) {
3d9449a1 3471 ssh_set_frozen(ssh, 1);
3472 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3473 ssh_dialog_callback, ssh);
3474 if (s->dlgret < 0) {
3475 do {
3476 crReturn(0);
3477 if (pktin) {
3478 bombout(("Unexpected data from server while waiting"
3479 " for user response"));
3480 crStop(0);
3481 }
3482 } while (pktin || inlen > 0);
3483 s->dlgret = ssh->user_response;
3484 }
3485 ssh_set_frozen(ssh, 0);
3486 if (s->dlgret == 0) {
9e296bfa 3487 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3488 0, TRUE);
96ccde8b 3489 crStop(0);
3d9449a1 3490 }
bb348ab1 3491 }
bea1ef5f 3492 }
ca20bfcf 3493
51470298 3494 switch (s->cipher_type) {
32874aea 3495 case SSH_CIPHER_3DES:
3496 logevent("Using 3DES encryption");
3497 break;
3498 case SSH_CIPHER_DES:
3499 logevent("Using single-DES encryption");
3500 break;
3501 case SSH_CIPHER_BLOWFISH:
3502 logevent("Using Blowfish encryption");
3503 break;
c5e9c988 3504 }
bea1ef5f 3505
51470298 3506 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3507 PKT_CHAR, s->cipher_type,
32874aea 3508 PKT_DATA, cookie, 8,
51470298 3509 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3510 PKT_DATA, s->rsabuf, s->len,
3511 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3512
c5e9c988 3513 logevent("Trying to enable encryption...");
374330e2 3514
51470298 3515 sfree(s->rsabuf);
374330e2 3516
51470298 3517 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3518 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3519 &ssh_3des);
371e569c 3520 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3521 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3522 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3523
0183b242 3524 ssh->crcda_ctx = crcda_make_context();
3525 logevent("Installing CRC compensation attack detector");
3526
679539d7 3527 if (servkey.modulus) {
3528 sfree(servkey.modulus);
3529 servkey.modulus = NULL;
3530 }
3531 if (servkey.exponent) {
3532 sfree(servkey.exponent);
3533 servkey.exponent = NULL;
3534 }
3535 if (hostkey.modulus) {
3536 sfree(hostkey.modulus);
3537 hostkey.modulus = NULL;
3538 }
3539 if (hostkey.exponent) {
3540 sfree(hostkey.exponent);
3541 hostkey.exponent = NULL;
3542 }
ff3187f6 3543 crWaitUntil(pktin);
374330e2 3544
ff3187f6 3545 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3546 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3547 crStop(0);
8d5de777 3548 }
374330e2 3549
c5e9c988 3550 logevent("Successfully started encryption");
3551
edd0cb8a 3552 fflush(stdout); /* FIXME eh? */
374330e2 3553 {
4a693cfc 3554 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 3555 int ret; /* need not be kept over crReturn */
3556 s->cur_prompt = new_prompts(ssh->frontend);
3557 s->cur_prompt->to_server = TRUE;
3558 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 3559 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 3560 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3561 while (ret < 0) {
51470298 3562 ssh->send_ok = 1;
edd0cb8a 3563 crWaitUntil(!pktin);
3564 ret = get_userpass_input(s->cur_prompt, in, inlen);
3565 ssh->send_ok = 0;
3566 }
3567 if (!ret) {
3568 /*
3569 * Failed to get a username. Terminate.
3570 */
3571 free_prompts(s->cur_prompt);
3572 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3573 crStop(0);
32874aea 3574 }
4a693cfc 3575 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 3576 free_prompts(s->cur_prompt);
374330e2 3577 }
fb09bf1c 3578
4a693cfc 3579 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
c5e9c988 3580 {
4a693cfc 3581 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
c5e9c988 3582 logevent(userlog);
32874aea 3583 if (flags & FLAG_INTERACTIVE &&
3584 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
51470298 3585 c_write_str(ssh, userlog);
edd0cb8a 3586 c_write_str(ssh, "\r\n");
3c8e959b 3587 }
edd0cb8a 3588 sfree(userlog);
c5e9c988 3589 }
374330e2 3590 }
3591
ff3187f6 3592 crWaitUntil(pktin);
374330e2 3593
d5b2c841 3594 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
0df73905 3595 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3596 s->tried_publickey = s->tried_agent = 1;
0df73905 3597 } else {
51470298 3598 s->tried_publickey = s->tried_agent = 0;
0df73905 3599 }
51470298 3600 s->tis_auth_refused = s->ccard_auth_refused = 0;
edd0cb8a 3601 /*
3602 * Load the public half of any configured keyfile for later use.
3603 */
4a693cfc 3604 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 3605 if (!filename_is_null(s->keyfile)) {
edd0cb8a 3606 int keytype;
3607 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 3608 filename_to_str(s->keyfile));
3609 keytype = key_type(s->keyfile);
edd0cb8a 3610 if (keytype == SSH_KEYTYPE_SSH1) {
3611 const char *error;
4a693cfc 3612 if (rsakey_pubblob(s->keyfile,
edd0cb8a 3613 &s->publickey_blob, &s->publickey_bloblen,
3614 &s->publickey_comment, &error)) {
4a693cfc 3615 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
edd0cb8a 3616 NULL);
3617 } else {
3618 char *msgbuf;
3619 logeventf(ssh, "Unable to load private key (%s)", error);
3620 msgbuf = dupprintf("Unable to load private key file "
3621 "\"%.150s\" (%s)\r\n",
4a693cfc 3622 filename_to_str(s->keyfile),
edd0cb8a 3623 error);
3624 c_write_str(ssh, msgbuf);
3625 sfree(msgbuf);
3626 s->publickey_blob = NULL;
3627 }
3628 } else {
3629 char *msgbuf;
3630 logeventf(ssh, "Unable to use this key file (%s)",
3631 key_type_to_str(keytype));
3632 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3633 " (%s)\r\n",
4a693cfc 3634 filename_to_str(s->keyfile),
edd0cb8a 3635 key_type_to_str(keytype));
3636 c_write_str(ssh, msgbuf);
3637 sfree(msgbuf);
51470298 3638 s->publickey_blob = NULL;
edd0cb8a 3639 }
396778f1 3640 } else
51470298 3641 s->publickey_blob = NULL;
7cca0d81 3642
ff3187f6 3643 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3644 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3645
4a693cfc 3646 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
32874aea 3647 /*
3648 * Attempt RSA authentication using Pageant.
3649 */
32874aea 3650 void *r;
3651
51470298 3652 s->authed = FALSE;
3653 s->tried_agent = 1;
32874aea 3654 logevent("Pageant is running. Requesting keys.");
3655
3656 /* Request the keys held by the agent. */
51470298 3657 PUT_32BIT(s->request, 1);
3658 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3659 if (!agent_query(s->request, 5, &r, &s->responselen,
3660 ssh_agent_callback, ssh)) {
3661 do {
3662 crReturn(0);
ff3187f6 3663 if (pktin) {
839f10db 3664 bombout(("Unexpected data from server while waiting"
3665 " for agent response"));
3666 crStop(0);
3667 }
ff3187f6 3668 } while (pktin || inlen > 0);
839f10db 3669 r = ssh->agent_response;
3670 s->responselen = ssh->agent_response_len;
3671 }
51470298 3672 s->response = (unsigned char *) r;
3673 if (s->response && s->responselen >= 5 &&
3674 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3675 s->p = s->response + 5;
3676 s->nkeys = GET_32BIT(s->p);
3677 s->p += 4;
2e85c969 3678 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
51470298 3679 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
94cd7c3a 3680 unsigned char *pkblob = s->p;
51470298 3681 s->p += 4;
0016d70b 3682 {
3683 int n, ok = FALSE;
3684 do { /* do while (0) to make breaking easy */
3685 n = ssh1_read_bignum
3686 (s->p, s->responselen-(s->p-s->response),
3687 &s->key.exponent);
3688 if (n < 0)
3689 break;
3690 s->p += n;
3691 n = ssh1_read_bignum
3692 (s->p, s->responselen-(s->p-s->response),
3693 &s->key.modulus);
3694 if (n < 0)
3695 break;
3696 s->p += n;
3697 if (s->responselen - (s->p-s->response) < 4)
3698 break;
3699 s->commentlen = GET_32BIT(s->p);
3700 s->p += 4;
3701 if (s->responselen - (s->p-s->response) <
3702 s->commentlen)
3703 break;
3704 s->commentp = (char *)s->p;
3705 s->p += s->commentlen;
3706 ok = TRUE;
3707 } while (0);
3708 if (!ok) {
3709 logevent("Pageant key list packet was truncated");
3710 break;
3711 }
3712 }
94cd7c3a 3713 if (s->publickey_blob) {
3714 if (!memcmp(pkblob, s->publickey_blob,
3715 s->publickey_bloblen)) {
3716 logeventf(ssh, "Pageant key #%d matches "
3717 "configured key file", s->keyi);
3718 s->tried_publickey = 1;
3719 } else
3720 /* Skip non-configured key */
3721 continue;
3722 }
3723 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3724 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3725 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3726 crWaitUntil(pktin);
3727 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3728 logevent("Key refused");
3729 continue;
3730 }
3731 logevent("Received RSA challenge");
ff3187f6 3732 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3733 bombout(("Server's RSA challenge was badly formatted"));
3734 crStop(0);
3735 }
3736
32874aea 3737 {
3738 char *agentreq, *q, *ret;
2d466ffd 3739 void *vret;
32874aea 3740 int len, retlen;
3741 len = 1 + 4; /* message type, bit count */
51470298 3742 len += ssh1_bignum_length(s->key.exponent);
3743 len += ssh1_bignum_length(s->key.modulus);
3744 len += ssh1_bignum_length(s->challenge);
32874aea 3745 len += 16; /* session id */
3746 len += 4; /* response format */
3d88e64d 3747 agentreq = snewn(4 + len, char);
32874aea 3748 PUT_32BIT(agentreq, len);
3749 q = agentreq + 4;
3750 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3751 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3752 q += 4;
51470298 3753 q += ssh1_write_bignum(q, s->key.exponent);
3754 q += ssh1_write_bignum(q, s->key.modulus);
3755 q += ssh1_write_bignum(q, s->challenge);
3756 memcpy(q, s->session_id, 16);
32874aea 3757 q += 16;
3758 PUT_32BIT(q, 1); /* response format */
839f10db 3759 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3760 ssh_agent_callback, ssh)) {
3761 sfree(agentreq);
3762 do {
3763 crReturn(0);
ff3187f6 3764 if (pktin) {
839f10db 3765 bombout(("Unexpected data from server"
3766 " while waiting for agent"
3767 " response"));
3768 crStop(0);
3769 }
ff3187f6 3770 } while (pktin || inlen > 0);
839f10db 3771 vret = ssh->agent_response;
3772 retlen = ssh->agent_response_len;
3773 } else
3774 sfree(agentreq);
2d466ffd 3775 ret = vret;
32874aea 3776 if (ret) {
3777 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3778 logevent("Sending Pageant's response");
51470298 3779 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3780 PKT_DATA, ret + 5, 16,
3781 PKT_END);
3782 sfree(ret);
ff3187f6 3783 crWaitUntil(pktin);
3784 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3785 logevent
3786 ("Pageant's response accepted");
3787 if (flags & FLAG_VERBOSE) {
51470298 3788 c_write_str(ssh, "Authenticated using"
3789 " RSA key \"");
3790 c_write(ssh, s->commentp,
3791 s->commentlen);
3792 c_write_str(ssh, "\" from agent\r\n");
32874aea 3793 }
51470298 3794 s->authed = TRUE;
32874aea 3795 } else
3796 logevent
3797 ("Pageant's response not accepted");
3798 } else {
3799 logevent
3800 ("Pageant failed to answer challenge");
3801 sfree(ret);
3802 }
3803 } else {
3804 logevent("No reply received from Pageant");
3805 }
3806 }
51470298 3807 freebn(s->key.exponent);
3808 freebn(s->key.modulus);
3809 freebn(s->challenge);
3810 if (s->authed)
32874aea 3811 break;
3812 }
29b1d0b3 3813 sfree(s->response);
94cd7c3a 3814 if (s->publickey_blob && !s->tried_publickey)
3815 logevent("Configured key file not in Pageant");
5ff99b8e 3816 } else {
3817 logevent("Failed to get reply from Pageant");
3818 }
51470298 3819 if (s->authed)
32874aea 3820 break;
3821 }
edd0cb8a 3822 if (s->publickey_blob && !s->tried_publickey) {
3823 /*
3824 * Try public key authentication with the specified
3825 * key file.
3826 */
3827 int got_passphrase; /* need not be kept over crReturn */
3828 if (flags & FLAG_VERBOSE)
3829 c_write_str(ssh, "Trying public key authentication.\r\n");
4a693cfc 3830 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
edd0cb8a 3831 logeventf(ssh, "Trying public key \"%s\"",
4a693cfc 3832 filename_to_str(s->keyfile));
edd0cb8a 3833 s->tried_publickey = 1;
3834 got_passphrase = FALSE;
3835 while (!got_passphrase) {
3836 /*
3837 * Get a passphrase, if necessary.
3838 */
3839 char *passphrase = NULL; /* only written after crReturn */
3840 const char *error;
3841 if (!s->publickey_encrypted) {
3842 if (flags & FLAG_VERBOSE)
3843 c_write_str(ssh, "No passphrase required.\r\n");
3844 passphrase = NULL;
3845 } else {
3846 int ret; /* need not be kept over crReturn */
3847 s->cur_prompt = new_prompts(ssh->frontend);
3848 s->cur_prompt->to_server = FALSE;
3849 s->cur_prompt->name = dupstr("SSH key passphrase");
3850 add_prompt(s->cur_prompt,
3851 dupprintf("Passphrase for key \"%.100s\": ",
b61f81bc 3852 s->publickey_comment), FALSE);
edd0cb8a 3853 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3854 while (ret < 0) {
3855 ssh->send_ok = 1;
3856 crWaitUntil(!pktin);
3857 ret = get_userpass_input(s->cur_prompt, in, inlen);
3858 ssh->send_ok = 0;
3859 }
3860 if (!ret) {
3861 /* Failed to get a passphrase. Terminate. */
3862 free_prompts(s->cur_prompt);
3863 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3864 0, TRUE);
3865 crStop(0);
3866 }
3867 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3868 free_prompts(s->cur_prompt);
3869 }
3870 /*
3871 * Try decrypting key with passphrase.
3872 */
4a693cfc 3873 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3874 ret = loadrsakey(s->keyfile, &s->key, passphrase,
edd0cb8a 3875 &error);
3876 if (passphrase) {
dfb88efd 3877 smemclr(passphrase, strlen(passphrase));
edd0cb8a 3878 sfree(passphrase);
3879 }
3880 if (ret == 1) {
3881 /* Correct passphrase. */
3882 got_passphrase = TRUE;
3883 } else if (ret == 0) {
3884 c_write_str(ssh, "Couldn't load private key from ");
4a693cfc 3885 c_write_str(ssh, filename_to_str(s->keyfile));
edd0cb8a 3886 c_write_str(ssh, " (");
3887 c_write_str(ssh, error);
3888 c_write_str(ssh, ").\r\n");
3889 got_passphrase = FALSE;
3890 break; /* go and try something else */
3891 } else if (ret == -1) {
3892 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
edd0cb8a 3893 got_passphrase = FALSE;
3894 /* and try again */
43536490 3895 } else {
3896 assert(0 && "unexpected return from loadrsakey()");
edc23a8a 3897 got_passphrase = FALSE; /* placate optimisers */
edd0cb8a 3898 }
3899 }
3900
3901 if (got_passphrase) {
3902
3903 /*
3904 * Send a public key attempt.
3905 */
3906 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3907 PKT_BIGNUM, s->key.modulus, PKT_END);
3908
3909 crWaitUntil(pktin);
3910 if (pktin->type == SSH1_SMSG_FAILURE) {
3911 c_write_str(ssh, "Server refused our public key.\r\n");
7b575324 3912 continue; /* go and try something else */
edd0cb8a 3913 }
3914 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3915 bombout(("Bizarre response to offer of public key"));
3916 crStop(0);
3917 }
3918
3919 {
3920 int i;
3921 unsigned char buffer[32];
3922 Bignum challenge, response;
3923
3924 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3925 bombout(("Server's RSA challenge was badly formatted"));
3926 crStop(0);
3927 }
3928 response = rsadecrypt(challenge, &s->key);
3929 freebn(s->key.private_exponent);/* burn the evidence */
3930
3931 for (i = 0; i < 32; i++) {
3932 buffer[i] = bignum_byte(response, 31 - i);
3933 }
3934
3935 MD5Init(&md5c);
3936 MD5Update(&md5c, buffer, 32);
3937 MD5Update(&md5c, s->session_id, 16);
3938 MD5Final(buffer, &md5c);
3939
3940 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3941 PKT_DATA, buffer, 16, PKT_END);
3942
3943 freebn(challenge);
3944 freebn(response);
3945 }
3946
3947 crWaitUntil(pktin);
3948 if (pktin->type == SSH1_SMSG_FAILURE) {
3949 if (flags & FLAG_VERBOSE)
3950 c_write_str(ssh, "Failed to authenticate with"
3951 " our public key.\r\n");
7b575324 3952 continue; /* go and try something else */
edd0cb8a 3953 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3954 bombout(("Bizarre response to RSA authentication response"));
3955 crStop(0);
3956 }
3957
3958 break; /* we're through! */
3959 }
3960
3961 }
3962
3963 /*
3964 * Otherwise, try various forms of password-like authentication.
3965 */
3966 s->cur_prompt = new_prompts(ssh->frontend);
32874aea 3967
4a693cfc 3968 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 3969 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3970 !s->tis_auth_refused) {
3971 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3972 logevent("Requested TIS authentication");
51470298 3973 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3974 crWaitUntil(pktin);
3975 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3976 logevent("TIS authentication declined");
3977 if (flags & FLAG_INTERACTIVE)
51470298 3978 c_write_str(ssh, "TIS authentication refused.\r\n");
3979 s->tis_auth_refused = 1;
614a20a0 3980 continue;
32874aea 3981 } else {
0016d70b 3982 char *challenge;
3983 int challengelen;
edd0cb8a 3984 char *instr_suf, *prompt;
0016d70b 3985
ff3187f6 3986 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3987 if (!challenge) {
3988 bombout(("TIS challenge packet was badly formed"));
3989 crStop(0);
3990 }
32874aea 3991 logevent("Received TIS challenge");
edd0cb8a 3992 s->cur_prompt->to_server = TRUE;
3993 s->cur_prompt->name = dupstr("SSH TIS authentication");
614a20a0 3994 /* Prompt heuristic comes from OpenSSH */
edd0cb8a 3995 if (memchr(challenge, '\n', challengelen)) {
3996 instr_suf = dupstr("");
3997 prompt = dupprintf("%.*s", challengelen, challenge);
3998 } else {
3999 instr_suf = dupprintf("%.*s", challengelen, challenge);
4000 prompt = dupstr("Response: ");
4001 }
4002 s->cur_prompt->instruction =
4003 dupprintf("Using TIS authentication.%s%s",
4004 (*instr_suf) ? "\n" : "",
4005 instr_suf);
4006 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 4007 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 4008 sfree(instr_suf);
32874aea 4009 }
4010 }
4a693cfc 4011 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 4012 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4013 !s->ccard_auth_refused) {
4014 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 4015 logevent("Requested CryptoCard authentication");
51470298 4016 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 4017 crWaitUntil(pktin);
4018 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 4019 logevent("CryptoCard authentication declined");
51470298 4020 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4021 s->ccard_auth_refused = 1;
614a20a0 4022 continue;
32874aea 4023 } else {
0016d70b 4024 char *challenge;
4025 int challengelen;
edd0cb8a 4026 char *instr_suf, *prompt;
0016d70b 4027
ff3187f6 4028 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 4029 if (!challenge) {
4030 bombout(("CryptoCard challenge packet was badly formed"));
4031 crStop(0);
4032 }
32874aea 4033 logevent("Received CryptoCard challenge");
edd0cb8a 4034 s->cur_prompt->to_server = TRUE;
4035 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4036 s->cur_prompt->name_reqd = FALSE;
4037 /* Prompt heuristic comes from OpenSSH */
4038 if (memchr(challenge, '\n', challengelen)) {
4039 instr_suf = dupstr("");
4040 prompt = dupprintf("%.*s", challengelen, challenge);
4041 } else {
4042 instr_suf = dupprintf("%.*s", challengelen, challenge);
4043 prompt = dupstr("Response: ");
4044 }
4045 s->cur_prompt->instruction =
4046 dupprintf("Using CryptoCard authentication.%s%s",
4047 (*instr_suf) ? "\n" : "",
4048 instr_suf);
4049 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 4050 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 4051 sfree(instr_suf);
32874aea 4052 }
4053 }
51470298 4054 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
8f9e3231 4055 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4056 bombout(("No supported authentication methods available"));
4057 crStop(0);
4058 }
edd0cb8a 4059 s->cur_prompt->to_server = TRUE;
4060 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 4061 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4062 ssh->username, ssh->savedhost),
b61f81bc 4063 FALSE);
32874aea 4064 }
a52f067e 4065
614a20a0 4066 /*
4067 * Show password prompt, having first obtained it via a TIS
4068 * or CryptoCard exchange if we're doing TIS or CryptoCard
4069 * authentication.
4070 */
edd0cb8a 4071 {
4072 int ret; /* need not be kept over crReturn */
4073 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4074 while (ret < 0) {
4075 ssh->send_ok = 1;
4076 crWaitUntil(!pktin);
4077 ret = get_userpass_input(s->cur_prompt, in, inlen);
4078 ssh->send_ok = 0;
4079 }
4080 if (!ret) {
32874aea 4081 /*
edd0cb8a 4082 * Failed to get a password (for example
32874aea 4083 * because one was supplied on the command line
4084 * which has already failed to work). Terminate.
4085 */
edd0cb8a 4086 free_prompts(s->cur_prompt);
4087 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4088 crStop(0);
32874aea 4089 }
32874aea 4090 }
4091
edd0cb8a 4092 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 4093 /*
edd0cb8a 4094 * Defence against traffic analysis: we send a
4095 * whole bunch of packets containing strings of
4096 * different lengths. One of these strings is the
4097 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4098 * The others are all random data in
4099 * SSH1_MSG_IGNORE packets. This way a passive
4100 * listener can't tell which is the password, and
4101 * hence can't deduce the password length.
4102 *
4103 * Anybody with a password length greater than 16
4104 * bytes is going to have enough entropy in their
4105 * password that a listener won't find it _that_
4106 * much help to know how long it is. So what we'll
4107 * do is:
4108 *
4109 * - if password length < 16, we send 15 packets
4110 * containing string lengths 1 through 15
4111 *
4112 * - otherwise, we let N be the nearest multiple
4113 * of 8 below the password length, and send 8
4114 * packets containing string lengths N through
4115 * N+7. This won't obscure the order of
4116 * magnitude of the password length, but it will
4117 * introduce a bit of extra uncertainty.
4118 *
bf982899 4119 * A few servers can't deal with SSH1_MSG_IGNORE, at
4120 * least in this context. For these servers, we need
4121 * an alternative defence. We make use of the fact
4122 * that the password is interpreted as a C string:
4123 * so we can append a NUL, then some random data.
edd0cb8a 4124 *
bf982899 4125 * A few servers can deal with neither SSH1_MSG_IGNORE
4126 * here _nor_ a padded password string.
4127 * For these servers we are left with no defences
edd0cb8a 4128 * against password length sniffing.
32874aea 4129 */
bf982899 4130 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4131 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
32874aea 4132 /*
edd0cb8a 4133 * The server can deal with SSH1_MSG_IGNORE, so
4134 * we can use the primary defence.
32874aea 4135 */
edd0cb8a 4136 int bottom, top, pwlen, i;
4137 char *randomstr;
32874aea 4138
edd0cb8a 4139 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4140 if (pwlen < 16) {
4141 bottom = 0; /* zero length passwords are OK! :-) */
4142 top = 15;
4143 } else {
4144 bottom = pwlen & ~7;
4145 top = bottom + 7;
4146 }
32874aea 4147
edd0cb8a 4148 assert(pwlen >= bottom && pwlen <= top);
32874aea 4149
edd0cb8a 4150 randomstr = snewn(top + 1, char);
32874aea 4151
edd0cb8a 4152 for (i = bottom; i <= top; i++) {
4153 if (i == pwlen) {
4154 defer_packet(ssh, s->pwpkt_type,
4155 PKTT_PASSWORD, PKT_STR,
4156 s->cur_prompt->prompts[0]->result,
4157 PKTT_OTHER, PKT_END);
4158 } else {
4159 for (j = 0; j < i; j++) {
4160 do {
4161 randomstr[j] = random_byte();
4162 } while (randomstr[j] == '\0');
32874aea 4163 }
edd0cb8a 4164 randomstr[i] = '\0';
4165 defer_packet(ssh, SSH1_MSG_IGNORE,
4166 PKT_STR, randomstr, PKT_END);
32874aea 4167 }
edd0cb8a 4168 }
4169 logevent("Sending password with camouflage packets");
4170 ssh_pkt_defersend(ssh);
4171 sfree(randomstr);
4172 }
4173 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4174 /*
4175 * The server can't deal with SSH1_MSG_IGNORE
4176 * but can deal with padded passwords, so we
4177 * can use the secondary defence.
4178 */
4179 char string[64];
4180 char *ss;
4181 int len;
4182
4183 len = strlen(s->cur_prompt->prompts[0]->result);
4184 if (len < sizeof(string)) {
4185 ss = string;
4186 strcpy(string, s->cur_prompt->prompts[0]->result);
4187 len++; /* cover the zero byte */
4188 while (len < sizeof(string)) {
4189 string[len++] = (char) random_byte();
bd358db1 4190 }
bd358db1 4191 } else {
edd0cb8a 4192 ss = s->cur_prompt->prompts[0]->result;
32874aea 4193 }
edd0cb8a 4194 logevent("Sending length-padded password");
9a10ecf4 4195 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
edd0cb8a 4196 PKT_INT, len, PKT_DATA, ss, len,
4197 PKTT_OTHER, PKT_END);
4198 } else {
4199 /*
bf982899 4200 * The server is believed unable to cope with
4201 * any of our password camouflage methods.
edd0cb8a 4202 */
4203 int len;
4204 len = strlen(s->cur_prompt->prompts[0]->result);
4205 logevent("Sending unpadded password");
4206 send_packet(ssh, s->pwpkt_type,
4207 PKTT_PASSWORD, PKT_INT, len,
4208 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4209 PKTT_OTHER, PKT_END);
32874aea 4210 }
edd0cb8a 4211 } else {
4212 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4213 PKT_STR, s->cur_prompt->prompts[0]->result,
4214 PKTT_OTHER, PKT_END);
32874aea 4215 }
c5e9c988 4216 logevent("Sent password");
edd0cb8a 4217 free_prompts(s->cur_prompt);
ff3187f6 4218 crWaitUntil(pktin);
4219 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4220 if (flags & FLAG_VERBOSE)
51470298 4221 c_write_str(ssh, "Access denied\r\n");
c5e9c988 4222 logevent("Authentication refused");
ff3187f6 4223 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4224 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 4225 crStop(0);
374330e2 4226 }
4227 }
4228
edd0cb8a 4229 /* Clear up */
4230 if (s->publickey_blob) {
4231 sfree(s->publickey_blob);
4232 sfree(s->publickey_comment);
4233 }
4234
c5e9c988 4235 logevent("Authentication successful");
4236
fb09bf1c 4237 crFinish(1);
4238}
4239
bc06669b 4240static void ssh_channel_try_eof(struct ssh_channel *c)
4241{
4242 Ssh ssh = c->ssh;
4243 assert(c->pending_eof); /* precondition for calling us */
4244 if (c->halfopen)
4245 return; /* can't close: not even opened yet */
4246 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4247 return; /* can't send EOF: pending outgoing data */
4248
3620f307 4249 c->pending_eof = FALSE; /* we're about to send it */
bc06669b 4250 if (ssh->version == 1) {
4251 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4252 PKT_END);
4253 c->closes |= CLOSES_SENT_EOF;
4254 } else {
4255 struct Packet *pktout;
4256 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4257 ssh2_pkt_adduint32(pktout, c->remoteid);
4258 ssh2_pkt_send(ssh, pktout);
4259 c->closes |= CLOSES_SENT_EOF;
3620f307 4260 ssh2_channel_check_close(c);
bc06669b 4261 }
bc06669b 4262}
4263
4264void sshfwd_write_eof(struct ssh_channel *c)
32874aea 4265{
51470298 4266 Ssh ssh = c->ssh;
4267
1ef619ae 4268 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4269 return;
36f94d1f 4270
bc06669b 4271 if (c->closes & CLOSES_SENT_EOF)
4272 return;
78280721 4273
bc06669b 4274 c->pending_eof = TRUE;
4275 ssh_channel_try_eof(c);
32874aea 4276}
4277
c6b41791 4278void sshfwd_unclean_close(struct ssh_channel *c)
4279{
4280 Ssh ssh = c->ssh;
c6b41791 4281
4282 if (ssh->state == SSH_STATE_CLOSED)
4283 return;
4284
c6b41791 4285 switch (c->type) {
4286 case CHAN_X11:
4287 x11_close(c->u.x11.s);
04120005 4288 logevent("Forwarded X11 connection terminated due to local error");
c6b41791 4289 break;
4290 case CHAN_SOCKDATA:
4291 case CHAN_SOCKDATA_DORMANT:
4292 pfd_close(c->u.pfd.s);
04120005 4293 logevent("Forwarded port closed due to local error");
c6b41791 4294 break;
4295 }
4296 c->type = CHAN_ZOMBIE;
96210393 4297
c6b41791 4298 ssh2_channel_check_close(c);
4299}
4300
5471d09a 4301int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 4302{
51470298 4303 Ssh ssh = c->ssh;
4304
1ef619ae 4305 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4306 return 0;
36f94d1f 4307
51470298 4308 if (ssh->version == 1) {
4309 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 4310 PKT_INT, c->remoteid,
a2724fba 4311 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
9a10ecf4 4312 PKTT_OTHER, PKT_END);
5471d09a 4313 /*
2e85c969 4314 * In SSH-1 we can return 0 here - implying that forwarded
5471d09a 4315 * connections are never individually throttled - because
4316 * the only circumstance that can cause throttling will be
4317 * the whole SSH connection backing up, in which case
4318 * _everything_ will be throttled as a whole.
4319 */
4320 return 0;
783415f8 4321 } else {
32874aea 4322 ssh2_add_channel_data(c, buf, len);
5471d09a 4323 return ssh2_try_send(c);
4324 }
4325}
4326
4327void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4328{
51470298 4329 Ssh ssh = c->ssh;
ff68564b 4330 int buflimit;
51470298 4331
1ef619ae 4332 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4333 return;
36f94d1f 4334
51470298 4335 if (ssh->version == 1) {
ff68564b 4336 buflimit = SSH1_BUFFER_LIMIT;
5471d09a 4337 } else {
ff68564b 4338 buflimit = c->v.v2.locmaxwin;
4339 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4340 }
4341 if (c->throttling_conn && bufsize <= buflimit) {
4342 c->throttling_conn = 0;
4343 ssh_throttle_conn(ssh, -1);
783415f8 4344 }
9c964e85 4345}
4346
06fadff5 4347static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4348{
4349 struct queued_handler *qh = ssh->qhead;
4350
4351 assert(qh != NULL);
4352
4353 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4354
4355 if (qh->msg1 > 0) {
4356 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
bc074147 4357 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
06fadff5 4358 }
4359 if (qh->msg2 > 0) {
4360 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
bc074147 4361 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
06fadff5 4362 }
4363
4364 if (qh->next) {
4365 ssh->qhead = qh->next;
4366
4367 if (ssh->qhead->msg1 > 0) {
bc074147 4368 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
06fadff5 4369 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4370 }
4371 if (ssh->qhead->msg2 > 0) {
bc074147 4372 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
06fadff5 4373 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4374 }
4375 } else {
4376 ssh->qhead = ssh->qtail = NULL;
06fadff5 4377 }
4378
4379 qh->handler(ssh, pktin, qh->ctx);
4380
4381 sfree(qh);
4382}
4383
4384static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4385 chandler_fn_t handler, void *ctx)
4386{
4387 struct queued_handler *qh;
4388
4389 qh = snew(struct queued_handler);
4390 qh->msg1 = msg1;
4391 qh->msg2 = msg2;
4392 qh->handler = handler;
4393 qh->ctx = ctx;
4394 qh->next = NULL;
4395
4396 if (ssh->qtail == NULL) {
4397 ssh->qhead = qh;
4398
4399 if (qh->msg1 > 0) {
bc074147 4400 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
06fadff5 4401 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4402 }
4403 if (qh->msg2 > 0) {
bc074147 4404 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
06fadff5 4405 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4406 }
4407 } else {
4408 ssh->qtail->next = qh;
4409 }
4410 ssh->qtail = qh;
4411}
4412
4413static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4414{
4415 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4416
4417 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4418 SSH2_MSG_REQUEST_SUCCESS)) {
4419 logeventf(ssh, "Remote port forwarding from %s enabled",
4420 pf->sportdesc);
4421 } else {
4422 logeventf(ssh, "Remote port forwarding from %s refused",
4423 pf->sportdesc);
4424
4425 rpf = del234(ssh->rportfwds, pf);
4426 assert(rpf == pf);
8aea57fd 4427 pf->pfrec->remote = NULL;
fda2feb1 4428 free_rportfwd(pf);
06fadff5 4429 }
4430}
4431
4a693cfc 4432static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
06fadff5 4433{
84328ddb 4434 struct ssh_portfwd *epf;
4435 int i;
4a693cfc 4436 char *key, *val;
06fadff5 4437
fda2feb1 4438 if (!ssh->portfwds) {
4439 ssh->portfwds = newtree234(ssh_portcmp);
4440 } else {
4441 /*
4442 * Go through the existing port forwardings and tag them
84328ddb 4443 * with status==DESTROY. Any that we want to keep will be
4444 * re-enabled (status==KEEP) as we go through the
4445 * configuration and find out which bits are the same as
4446 * they were before.
fda2feb1 4447 */
4448 struct ssh_portfwd *epf;
4449 int i;
4450 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 4451 epf->status = DESTROY;
fda2feb1 4452 }
4453
4a693cfc 4454 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4455 val != NULL;
4456 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4457 char *kp, *kp2, *vp, *vp2;
84328ddb 4458 char address_family, type;
4459 int sport,dport,sserv,dserv;
4a693cfc 4460 char *sports, *dports, *saddr, *host;
4461
4462 kp = key;
84328ddb 4463
05581745 4464 address_family = 'A';
4465 type = 'L';
4a693cfc 4466 if (*kp == 'A' || *kp == '4' || *kp == '6')
4467 address_family = *kp++;
4468 if (*kp == 'L' || *kp == 'R')
4469 type = *kp++;
4470
4471 if ((kp2 = strchr(kp, ':')) != NULL) {
4472 /*
4473 * There's a colon in the middle of the source port
4474 * string, which means that the part before it is
4475 * actually a source address.
4476 */
4477 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4478 sports = kp2+1;
06fadff5 4479 } else {
4a693cfc 4480 saddr = NULL;
4481 sports = kp;
06fadff5 4482 }
4483 sport = atoi(sports);
4484 sserv = 0;
4485 if (sport == 0) {
4486 sserv = 1;
4487 sport = net_service_lookup(sports);
4488 if (!sport) {
4489 logeventf(ssh, "Service lookup failed for source"
4490 " port \"%s\"", sports);
4491 }
4492 }
4a693cfc 4493
4494 if (type == 'L' && !strcmp(val, "D")) {
4495 /* dynamic forwarding */
4496 host = NULL;
4497 dports = NULL;
4498 dport = -1;
4499 dserv = 0;
4500 type = 'D';
4501 } else {
4502 /* ordinary forwarding */
4503 vp = val;
4504 vp2 = vp + strcspn(vp, ":");
4505 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4506 if (vp2)
4507 vp2++;
4508 dports = vp2;
4509 dport = atoi(dports);
4510 dserv = 0;
4511 if (dport == 0) {
4512 dserv = 1;
4513 dport = net_service_lookup(dports);
4514 if (!dport) {
4515 logeventf(ssh, "Service lookup failed for destination"
4516 " port \"%s\"", dports);
4517 }
4518 }
4519 }
4520
06fadff5 4521 if (sport && dport) {
4522 /* Set up a description of the source port. */
fda2feb1 4523 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 4524
4525 pfrec = snew(struct ssh_portfwd);
4526 pfrec->type = type;
4a693cfc 4527 pfrec->saddr = saddr;
3fe92132 4528 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 4529 pfrec->sport = sport;
4a693cfc 4530 pfrec->daddr = host;
3fe92132 4531 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 4532 pfrec->dport = dport;
4533 pfrec->local = NULL;
4534 pfrec->remote = NULL;
05581745 4535 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4536 address_family == '6' ? ADDRTYPE_IPV6 :
4537 ADDRTYPE_UNSPEC);
fda2feb1 4538
4539 epfrec = add234(ssh->portfwds, pfrec);
4540 if (epfrec != pfrec) {
c00c1931 4541 if (epfrec->status == DESTROY) {
4542 /*
4543 * We already have a port forwarding up and running
4544 * with precisely these parameters. Hence, no need
4545 * to do anything; simply re-tag the existing one
4546 * as KEEP.
4547 */
4548 epfrec->status = KEEP;
4549 }
fda2feb1 4550 /*
c00c1931 4551 * Anything else indicates that there was a duplicate
4552 * in our input, which we'll silently ignore.
fda2feb1 4553 */
fda2feb1 4554 free_portfwd(pfrec);
84328ddb 4555 } else {
4556 pfrec->status = CREATE;
4557 }
4a693cfc 4558 } else {
4559 sfree(saddr);
4560 sfree(host);
84328ddb 4561 }
4562 }
4563
4564 /*
4565 * Now go through and destroy any port forwardings which were
4566 * not re-enabled.
4567 */
4568 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4569 if (epf->status == DESTROY) {
4570 char *message;
4571
4572 message = dupprintf("%s port forwarding from %s%s%d",
4573 epf->type == 'L' ? "local" :
4574 epf->type == 'R' ? "remote" : "dynamic",
4575 epf->saddr ? epf->saddr : "",
4576 epf->saddr ? ":" : "",
4577 epf->sport);
4578
4579 if (epf->type != 'D') {
4580 char *msg2 = dupprintf("%s to %s:%d", message,
4581 epf->daddr, epf->dport);
4582 sfree(message);
4583 message = msg2;
4584 }
4585
4586 logeventf(ssh, "Cancelling %s", message);
4587 sfree(message);
4588
8aea57fd 4589 /* epf->remote or epf->local may be NULL if setting up a
4590 * forwarding failed. */
84328ddb 4591 if (epf->remote) {
4592 struct ssh_rportfwd *rpf = epf->remote;
4593 struct Packet *pktout;
4594
4595 /*
4596 * Cancel the port forwarding at the server
4597 * end.
4598 */
4599 if (ssh->version == 1) {
4600 /*
4601 * We cannot cancel listening ports on the
2e85c969 4602 * server side in SSH-1! There's no message
84328ddb 4603 * to support it. Instead, we simply remove
4604 * the rportfwd record from the local end
4605 * so that any connections the server tries
4606 * to make on it are rejected.
4607 */
4608 } else {
4609 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4610 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4611 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4612 if (epf->saddr) {
4613 ssh2_pkt_addstring(pktout, epf->saddr);
4a693cfc 4614 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4615 /* XXX: rport_acceptall may not represent
5188540b 4616 * what was used to open the original connection,
4617 * since it's reconfigurable. */
84328ddb 4618 ssh2_pkt_addstring(pktout, "0.0.0.0");
4619 } else {
4620 ssh2_pkt_addstring(pktout, "127.0.0.1");
4621 }
4622 ssh2_pkt_adduint32(pktout, epf->sport);
4623 ssh2_pkt_send(ssh, pktout);
4624 }
4625
4626 del234(ssh->rportfwds, rpf);
4627 free_rportfwd(rpf);
4628 } else if (epf->local) {
4629 pfd_terminate(epf->local);
4630 }
4631
4632 delpos234(ssh->portfwds, i);
4633 free_portfwd(epf);
4634 i--; /* so we don't skip one in the list */
4635 }
4636
4637 /*
4638 * And finally, set up any new port forwardings (status==CREATE).
4639 */
4640 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4641 if (epf->status == CREATE) {
4642 char *sportdesc, *dportdesc;
3fe92132 4643 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 4644 epf->saddr ? epf->saddr : "",
4645 epf->saddr ? ":" : "",
3fe92132 4646 epf->sserv ? epf->sserv : "",
4647 epf->sserv ? "(" : "",
4648 epf->sport,
4649 epf->sserv ? ")" : "");
84328ddb 4650 if (epf->type == 'D') {
4651 dportdesc = NULL;
4652 } else {
3fe92132 4653 dportdesc = dupprintf("%s:%s%s%d%s",
4654 epf->daddr,
4655 epf->dserv ? epf->dserv : "",
4656 epf->dserv ? "(" : "",
4657 epf->dport,
4658 epf->dserv ? ")" : "");
84328ddb 4659 }
05581745 4660
84328ddb 4661 if (epf->type == 'L') {
4662 const char *err = pfd_addforward(epf->daddr, epf->dport,
4663 epf->saddr, epf->sport,
4a693cfc 4664 ssh, conf,
84328ddb 4665 &epf->local,
4666 epf->addressfamily);
4667
4668 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4669 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4670 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4671 sportdesc, dportdesc,
4672 err ? " failed: " : "", err ? err : "");
4673 } else if (epf->type == 'D') {
06fadff5 4674 const char *err = pfd_addforward(NULL, -1,
84328ddb 4675 epf->saddr, epf->sport,
4a693cfc 4676 ssh, conf,
84328ddb 4677 &epf->local,
4678 epf->addressfamily);
4679
4680 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4681 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4682 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4683 sportdesc,
4684 err ? " failed: " : "", err ? err : "");
06fadff5 4685 } else {
4686 struct ssh_rportfwd *pf;
4687
4688 /*
4689 * Ensure the remote port forwardings tree exists.
4690 */
4691 if (!ssh->rportfwds) {
4692 if (ssh->version == 1)
4693 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4694 else
4695 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4696 }
4697
4698 pf = snew(struct ssh_rportfwd);
84328ddb 4699 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4700 pf->dhost[lenof(pf->dhost)-1] = '\0';
4701 pf->dport = epf->dport;
4702 pf->sport = epf->sport;
06fadff5 4703 if (add234(ssh->rportfwds, pf) != pf) {
4704 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4705 epf->daddr, epf->dport);
06fadff5 4706 sfree(pf);
4707 } else {
4708 logeventf(ssh, "Requesting remote port %s"
84328ddb 4709 " forward to %s", sportdesc, dportdesc);
06fadff5 4710
4711 pf->sportdesc = sportdesc;
4712 sportdesc = NULL;
84328ddb 4713 epf->remote = pf;
4714 pf->pfrec = epf;
06fadff5 4715
4716 if (ssh->version == 1) {
4717 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4718 PKT_INT, epf->sport,
4719 PKT_STR, epf->daddr,
4720 PKT_INT, epf->dport,
06fadff5 4721 PKT_END);
4722 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4723 SSH1_SMSG_FAILURE,
4724 ssh_rportfwd_succfail, pf);
4725 } else {
4726 struct Packet *pktout;
4727 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4728 ssh2_pkt_addstring(pktout, "tcpip-forward");
4729 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4730 if (epf->saddr) {
4731 ssh2_pkt_addstring(pktout, epf->saddr);
4a693cfc 4732 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
06fadff5 4733 ssh2_pkt_addstring(pktout, "0.0.0.0");
4734 } else {
4735 ssh2_pkt_addstring(pktout, "127.0.0.1");
4736 }
84328ddb 4737 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4738 ssh2_pkt_send(ssh, pktout);
4739
4740 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4741 SSH2_MSG_REQUEST_FAILURE,
4742 ssh_rportfwd_succfail, pf);
4743 }
4744 }
4745 }
4746 sfree(sportdesc);
84328ddb 4747 sfree(dportdesc);
06fadff5 4748 }
06fadff5 4749}
4750
51df0ab5 4751static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4752{
4753 char *string;
4754 int stringlen, bufsize;
4755
4756 ssh_pkt_getstring(pktin, &string, &stringlen);
4757 if (string == NULL) {
4758 bombout(("Incoming terminal data packet was badly formed"));
4759 return;
4760 }
4761
4762 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4763 string, stringlen);
4764 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4765 ssh->v1_stdout_throttling = 1;
ff68564b 4766 ssh_throttle_conn(ssh, +1);
51df0ab5 4767 }
4768}
4769
4770static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4771{
4772 /* Remote side is trying to open a channel to talk to our
4773 * X-Server. Give them back a local channel number. */
4774 struct ssh_channel *c;
4775 int remoteid = ssh_pkt_getuint32(pktin);
4776
4777 logevent("Received X11 connect request");
4778 /* Refuse if X11 forwarding is disabled. */
4779 if (!ssh->X11_fwd_enabled) {
4780 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4781 PKT_INT, remoteid, PKT_END);
4782 logevent("Rejected X11 connect request");
4783 } else {
4784 c = snew(struct ssh_channel);
4785 c->ssh = ssh;
4786
8def70c3 4787 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4a693cfc 4788 NULL, -1, ssh->conf) != NULL) {
51df0ab5 4789 logevent("Opening X11 forward connection failed");
4790 sfree(c);
4791 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4792 PKT_INT, remoteid, PKT_END);
4793 } else {
4794 logevent
4795 ("Opening X11 forward connection succeeded");
4796 c->remoteid = remoteid;
64d6ff88 4797 c->halfopen = FALSE;
51df0ab5 4798 c->localid = alloc_channel_id(ssh);
4799 c->closes = 0;
bc06669b 4800 c->pending_eof = FALSE;
ff68564b 4801 c->throttling_conn = 0;
51df0ab5 4802 c->type = CHAN_X11; /* identify channel type */
4803 add234(ssh->channels, c);
4804 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4805 PKT_INT, c->remoteid, PKT_INT,
4806 c->localid, PKT_END);
4807 logevent("Opened X11 forward channel");
4808 }
4809 }
4810}
4811
4812static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4813{
4814 /* Remote side is trying to open a channel to talk to our
4815 * agent. Give them back a local channel number. */
4816 struct ssh_channel *c;
4817 int remoteid = ssh_pkt_getuint32(pktin);
4818
4819 /* Refuse if agent forwarding is disabled. */
4820 if (!ssh->agentfwd_enabled) {
4821 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4822 PKT_INT, remoteid, PKT_END);
4823 } else {
4824 c = snew(struct ssh_channel);
4825 c->ssh = ssh;
4826 c->remoteid = remoteid;
64d6ff88 4827 c->halfopen = FALSE;
51df0ab5 4828 c->localid = alloc_channel_id(ssh);
4829 c->closes = 0;
bc06669b 4830 c->pending_eof = FALSE;
ff68564b 4831 c->throttling_conn = 0;
51df0ab5 4832 c->type = CHAN_AGENT; /* identify channel type */
4833 c->u.a.lensofar = 0;
bc06669b 4834 c->u.a.message = NULL;
51df0ab5 4835 add234(ssh->channels, c);
4836 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4837 PKT_INT, c->remoteid, PKT_INT, c->localid,
4838 PKT_END);
4839 }
4840}
4841
4842static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4843{
4844 /* Remote side is trying to open a channel to talk to a
4845 * forwarded port. Give them back a local channel number. */
4846 struct ssh_channel *c;
05581745 4847 struct ssh_rportfwd pf, *pfp;
51df0ab5 4848 int remoteid;
4849 int hostsize, port;
fb983202 4850 char *host;
51df0ab5 4851 const char *e;
4852 c = snew(struct ssh_channel);
4853 c->ssh = ssh;
4854
4855 remoteid = ssh_pkt_getuint32(pktin);
4856 ssh_pkt_getstring(pktin, &host, &hostsize);
4857 port = ssh_pkt_getuint32(pktin);
4858
4859 if (hostsize >= lenof(pf.dhost))
4860 hostsize = lenof(pf.dhost)-1;
4861 memcpy(pf.dhost, host, hostsize);
4862 pf.dhost[hostsize] = '\0';
4863 pf.dport = port;
05581745 4864 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4865
05581745 4866 if (pfp == NULL) {
fb983202 4867 logeventf(ssh, "Rejected remote port open request for %s:%d",
4868 pf.dhost, port);
51df0ab5 4869 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4870 PKT_INT, remoteid, PKT_END);
4871 } else {
fb983202 4872 logeventf(ssh, "Received remote port open request for %s:%d",
4873 pf.dhost, port);
51df0ab5 4874 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4a693cfc 4875 c, ssh->conf, pfp->pfrec->addressfamily);
51df0ab5 4876 if (e != NULL) {
fb983202 4877 logeventf(ssh, "Port open failed: %s", e);
51df0ab5 4878 sfree(c);
4879 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4880 PKT_INT, remoteid, PKT_END);
4881 } else {
4882 c->remoteid = remoteid;
64d6ff88 4883 c->halfopen = FALSE;
51df0ab5 4884 c->localid = alloc_channel_id(ssh);
4885 c->closes = 0;
bc06669b 4886 c->pending_eof = FALSE;
ff68564b 4887 c->throttling_conn = 0;
51df0ab5 4888 c->type = CHAN_SOCKDATA; /* identify channel type */
4889 add234(ssh->channels, c);
4890 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4891 PKT_INT, c->remoteid, PKT_INT,
4892 c->localid, PKT_END);
4893 logevent("Forwarded port opened successfully");
4894 }
4895 }
4896}
4897
4898static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4899{
4900 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4901 unsigned int localid = ssh_pkt_getuint32(pktin);
4902 struct ssh_channel *c;
4903
4904 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4905 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4906 c->remoteid = localid;
64d6ff88 4907 c->halfopen = FALSE;
51df0ab5 4908 c->type = CHAN_SOCKDATA;
ff68564b 4909 c->throttling_conn = 0;
51df0ab5 4910 pfd_confirm(c->u.pfd.s);
4911 }
4912
bc06669b 4913 if (c && c->pending_eof) {
51df0ab5 4914 /*
4915 * We have a pending close on this channel,
4916 * which we decided on before the server acked
4917 * the channel open. So now we know the
4918 * remoteid, we can close it again.
4919 */
bc06669b 4920 ssh_channel_try_eof(c);
51df0ab5 4921 }
4922}
4923
4924static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4925{
4926 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4927 struct ssh_channel *c;
4928
4929 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4930 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4931 logevent("Forwarded connection refused by server");
4932 pfd_close(c->u.pfd.s);
4933 del234(ssh->channels, c);
4934 sfree(c);
4935 }
4936}
4937
4938static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4939{
4940 /* Remote side closes a channel. */
4941 unsigned i = ssh_pkt_getuint32(pktin);
4942 struct ssh_channel *c;
4943 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 4944 if (c && !c->halfopen) {
51df0ab5 4945
bc06669b 4946 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
4947 !(c->closes & CLOSES_RCVD_EOF)) {
4948 /*
4949 * Received CHANNEL_CLOSE, which we translate into
4950 * outgoing EOF.
4951 */
4952 int send_close = FALSE;
4953
4954 c->closes |= CLOSES_RCVD_EOF;
4955
4956 switch (c->type) {
4957 case CHAN_X11:
4958 if (c->u.x11.s)
4959 x11_send_eof(c->u.x11.s);
4960 else
4961 send_close = TRUE;
9fb91415 4962 break;
bc06669b 4963 case CHAN_SOCKDATA:
4964 if (c->u.pfd.s)
9fb91415 4965 pfd_send_eof(c->u.pfd.s);
bc06669b 4966 else
4967 send_close = TRUE;
9fb91415 4968 break;
bc06669b 4969 case CHAN_AGENT:
4970 send_close = TRUE;
9fb91415 4971 break;
bc06669b 4972 }
51df0ab5 4973
bc06669b 4974 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
4975 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4976 PKT_END);
4977 c->closes |= CLOSES_SENT_EOF;
4978 }
4979 }
4980
4981 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
4982 !(c->closes & CLOSES_RCVD_CLOSE)) {
4983
4984 if (!(c->closes & CLOSES_SENT_EOF)) {
4985 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
4986 " for which we never sent CHANNEL_CLOSE\n", i));
4987 }
4988
4989 c->closes |= CLOSES_RCVD_CLOSE;
4990 }
4991
4992 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
4993 !(c->closes & CLOSES_SENT_CLOSE)) {
4994 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
4995 PKT_INT, c->remoteid, PKT_END);
4996 c->closes |= CLOSES_SENT_CLOSE;
4997 }
4998
4999 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5000 ssh_channel_destroy(c);
51df0ab5 5001 } else {
5002 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5003 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5004 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5005 i));
5006 }
5007}
5008
5009static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5010{
5011 /* Data sent down one of our channels. */
5012 int i = ssh_pkt_getuint32(pktin);
5013 char *p;
6d44acc9 5014 int len;
51df0ab5 5015 struct ssh_channel *c;
5016
5017 ssh_pkt_getstring(pktin, &p, &len);
5018
5019 c = find234(ssh->channels, &i, ssh_channelfind);
5020 if (c) {
5021 int bufsize = 0;
5022 switch (c->type) {
5023 case CHAN_X11:
5024 bufsize = x11_send(c->u.x11.s, p, len);
5025 break;
5026 case CHAN_SOCKDATA:
5027 bufsize = pfd_send(c->u.pfd.s, p, len);
5028 break;
5029 case CHAN_AGENT:
5030 /* Data for an agent message. Buffer it. */
5031 while (len > 0) {
5032 if (c->u.a.lensofar < 4) {
62ddb51e 5033 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
51df0ab5 5034 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5035 l);
5036 p += l;
5037 len -= l;
5038 c->u.a.lensofar += l;
5039 }
5040 if (c->u.a.lensofar == 4) {
5041 c->u.a.totallen =
5042 4 + GET_32BIT(c->u.a.msglen);
5043 c->u.a.message = snewn(c->u.a.totallen,
5044 unsigned char);
5045 memcpy(c->u.a.message, c->u.a.msglen, 4);
5046 }
5047 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 5048 unsigned int l =
51df0ab5 5049 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 5050 (unsigned)len);
51df0ab5 5051 memcpy(c->u.a.message + c->u.a.lensofar, p,
5052 l);
5053 p += l;
5054 len -= l;
5055 c->u.a.lensofar += l;
5056 }
5057 if (c->u.a.lensofar == c->u.a.totallen) {
5058 void *reply;
5059 int replylen;
5060 if (agent_query(c->u.a.message,
5061 c->u.a.totallen,
5062 &reply, &replylen,
5063 ssh_agentf_callback, c))
5064 ssh_agentf_callback(c, reply, replylen);
5065 sfree(c->u.a.message);
5066 c->u.a.lensofar = 0;
5067 }
5068 }
5069 bufsize = 0; /* agent channels never back up */
5070 break;
5071 }
ff68564b 5072 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5073 c->throttling_conn = 1;
5074 ssh_throttle_conn(ssh, +1);
51df0ab5 5075 }
5076 }
5077}
5078
5079static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5080{
51df0ab5 5081 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 5082 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 5083 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5084 /*
5085 * In case `helpful' firewalls or proxies tack
5086 * extra human-readable text on the end of the
5087 * session which we might mistake for another
5088 * encrypted packet, we close the session once
5089 * we've sent EXIT_CONFIRMATION.
5090 */
9e296bfa 5091 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
51df0ab5 5092}
5093
c6ccd5c2 5094/* Helper function to deal with sending tty modes for REQUEST_PTY */
5095static void ssh1_send_ttymode(void *data, char *mode, char *val)
5096{
5097 struct Packet *pktout = (struct Packet *)data;
5098 int i = 0;
5099 unsigned int arg = 0;
5100 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5101 if (i == lenof(ssh_ttymodes)) return;
5102 switch (ssh_ttymodes[i].type) {
5103 case TTY_OP_CHAR:
5104 arg = ssh_tty_parse_specchar(val);
5105 break;
5106 case TTY_OP_BOOL:
5107 arg = ssh_tty_parse_boolean(val);
5108 break;
5109 }
5110 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5111 ssh2_pkt_addbyte(pktout, arg);
5112}
5113
5114
b09eaa88 5115static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5116 struct Packet *pktin)
32874aea 5117{
b09eaa88 5118 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 5119
51df0ab5 5120 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5121 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5122 ssh1_smsg_stdout_stderr_data;
5123
5124 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5125 ssh1_msg_channel_open_confirmation;
5126 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5127 ssh1_msg_channel_open_failure;
5128 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5129 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5130 ssh1_msg_channel_close;
5131 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5132 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5133
4a693cfc 5134 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
32874aea 5135 logevent("Requesting agent forwarding");
51470298 5136 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 5137 do {
5138 crReturnV;
ff3187f6 5139 } while (!pktin);
5140 if (pktin->type != SSH1_SMSG_SUCCESS
5141 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5142 bombout(("Protocol confusion"));
7ffdbc1a 5143 crStopV;
ff3187f6 5144 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5145 logevent("Agent forwarding refused");
5146 } else {
5147 logevent("Agent forwarding enabled");
51470298 5148 ssh->agentfwd_enabled = TRUE;
51df0ab5 5149 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 5150 }
dacbd0e8 5151 }
5152
4a693cfc 5153 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5154 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5155 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
32874aea 5156 logevent("Requesting X11 forwarding");
f68353be 5157 /*
5158 * Note that while we blank the X authentication data here, we don't
5159 * take any special action to blank the start of an X11 channel,
5160 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5161 * without having session blanking enabled is likely to leak your
5162 * cookie into the log.
5163 */
51470298 5164 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5165 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5166 PKT_STR, ssh->x11disp->remoteauthprotoname,
5167 PKTT_PASSWORD,
5168 PKT_STR, ssh->x11disp->remoteauthdatastring,
5169 PKTT_OTHER,
5170 PKT_INT, ssh->x11disp->screennum,
421d6835 5171 PKT_END);
32874aea 5172 } else {
51470298 5173 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5174 PKT_STR, ssh->x11disp->remoteauthprotoname,
5175 PKTT_PASSWORD,
5176 PKT_STR, ssh->x11disp->remoteauthdatastring,
5177 PKTT_OTHER,
5178 PKT_END);
32874aea 5179 }
5180 do {
5181 crReturnV;
ff3187f6 5182 } while (!pktin);
5183 if (pktin->type != SSH1_SMSG_SUCCESS
5184 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5185 bombout(("Protocol confusion"));
7ffdbc1a 5186 crStopV;
ff3187f6 5187 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5188 logevent("X11 forwarding refused");
5189 } else {
5190 logevent("X11 forwarding enabled");
51470298 5191 ssh->X11_fwd_enabled = TRUE;
51df0ab5 5192 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 5193 }
5194 }
5195
4a693cfc 5196 ssh_setup_portfwd(ssh, ssh->conf);
06fadff5 5197 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 5198
4a693cfc 5199 if (!conf_get_int(ssh->conf, CONF_nopty)) {
c6ccd5c2 5200 struct Packet *pkt;
a5dd8467 5201 /* Unpick the terminal-speed string. */
5202 /* XXX perhaps we should allow no speeds to be sent. */
db219738 5203 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4a693cfc 5204 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 5205 /* Send the pty request. */
c6ccd5c2 5206 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4a693cfc 5207 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
c6ccd5c2 5208 ssh_pkt_adduint32(pkt, ssh->term_height);
5209 ssh_pkt_adduint32(pkt, ssh->term_width);
5210 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5211 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4a693cfc 5212 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
c6ccd5c2 5213 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5214 ssh_pkt_adduint32(pkt, ssh->ispeed);
5215 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5216 ssh_pkt_adduint32(pkt, ssh->ospeed);
5217 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5218 s_wrpkt(ssh, pkt);
51470298 5219 ssh->state = SSH_STATE_INTERMED;
32874aea 5220 do {
5221 crReturnV;
ff3187f6 5222 } while (!pktin);
5223 if (pktin->type != SSH1_SMSG_SUCCESS
5224 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5225 bombout(("Protocol confusion"));
7ffdbc1a 5226 crStopV;
ff3187f6 5227 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5228 c_write_str(ssh, "Server refused to allocate pty\r\n");
5229 ssh->editing = ssh->echoing = 1;
4a202fc6 5230 } else {
5231 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5232 ssh->ospeed, ssh->ispeed);
5233 ssh->got_pty = TRUE;
5234 }
0965bee0 5235 } else {
51470298 5236 ssh->editing = ssh->echoing = 1;
374330e2 5237 }
5238
4a693cfc 5239 if (conf_get_int(ssh->conf, CONF_compression)) {
51470298 5240 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 5241 do {
5242 crReturnV;
ff3187f6 5243 } while (!pktin);
5244 if (pktin->type != SSH1_SMSG_SUCCESS
5245 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5246 bombout(("Protocol confusion"));
7ffdbc1a 5247 crStopV;
ff3187f6 5248 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5249 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 5250 }
4ba9b64b 5251 logevent("Started compression");
51470298 5252 ssh->v1_compressing = TRUE;
5366aed8 5253 ssh->cs_comp_ctx = zlib_compress_init();
5254 logevent("Initialised zlib (RFC1950) compression");
5255 ssh->sc_comp_ctx = zlib_decompress_init();
5256 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 5257 }
5258
fd5e5847 5259 /*
5260 * Start the shell or command.
5261 *
2e85c969 5262 * Special case: if the first-choice command is an SSH-2
fd5e5847 5263 * subsystem (hence not usable here) and the second choice
5264 * exists, we fall straight back to that.
5265 */
5266 {
4a693cfc 5267 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
fd5e5847 5268
4a693cfc 5269 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5270 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5271 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
51470298 5272 ssh->fallback_cmd = TRUE;
fd5e5847 5273 }
5274 if (*cmd)
51470298 5275 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 5276 else
51470298 5277 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 5278 logevent("Started session");
5279 }
374330e2 5280
51470298 5281 ssh->state = SSH_STATE_SESSION;
5282 if (ssh->size_needed)
5283 ssh_size(ssh, ssh->term_width, ssh->term_height);
5284 if (ssh->eof_needed)
5285 ssh_special(ssh, TS_EOF);
374330e2 5286
b9d7bcad 5287 if (ssh->ldisc)
5288 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5289 ssh->send_ok = 1;
5290 ssh->channels = newtree234(ssh_channelcmp);
374330e2 5291 while (1) {
d74d141c 5292
51df0ab5 5293 /*
5294 * By this point, most incoming packets are already being
5295 * handled by the dispatch table, and we need only pay
5296 * attention to the unusual ones.
5297 */
0357890f 5298
51df0ab5 5299 crReturnV;
5300 if (pktin) {
5301 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 5302 /* may be from EXEC_SHELL on some servers */
ff3187f6 5303 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 5304 /* may be from EXEC_SHELL on some servers
374330e2 5305 * if no pty is available or in other odd cases. Ignore */
374330e2 5306 } else {
ff3187f6 5307 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 5308 crStopV;
374330e2 5309 }
5310 } else {
8df7a775 5311 while (inlen > 0) {
5312 int len = min(inlen, 512);
a2724fba 5313 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5314 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
9a10ecf4 5315 PKTT_OTHER, PKT_END);
8df7a775 5316 in += len;
5317 inlen -= len;
5318 }
374330e2 5319 }
5320 }
5321
5322 crFinishV;
5323}
5324
5325/*
2e85c969 5326 * Handle the top-level SSH-2 protocol.
b09eaa88 5327 */
5328static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5329{
fb983202 5330 char *msg;
b09eaa88 5331 int msglen;
5332
5333 ssh_pkt_getstring(pktin, &msg, &msglen);
fb983202 5334 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 5335}
5336
5337static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5338{
5339 /* log reason code in disconnect message */
5340 char *msg;
5341 int msglen;
5342
5343 ssh_pkt_getstring(pktin, &msg, &msglen);
5344 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5345}
5346
409bfa77 5347static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
b09eaa88 5348{
5349 /* Do nothing, because we're ignoring it! Duhh. */
5350}
5351
5352static void ssh1_protocol_setup(Ssh ssh)
5353{
5354 int i;
5355
5356 /*
5357 * Most messages are handled by the coroutines.
5358 */
5359 for (i = 0; i < 256; i++)
5360 ssh->packet_dispatch[i] = NULL;
5361
5362 /*
5363 * These special message types we install handlers for.
5364 */
5365 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5366 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5367 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5368}
5369
1c1a7262 5370static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
b09eaa88 5371 struct Packet *pktin)
5372{
1c1a7262 5373 unsigned char *in=(unsigned char*)vin;
b09eaa88 5374 if (ssh->state == SSH_STATE_CLOSED)
5375 return;
5376
5377 if (pktin && ssh->packet_dispatch[pktin->type]) {
5378 ssh->packet_dispatch[pktin->type](ssh, pktin);
5379 return;
5380 }
5381
5382 if (!ssh->protocol_initial_phase_done) {
5383 if (do_ssh1_login(ssh, in, inlen, pktin))
5384 ssh->protocol_initial_phase_done = TRUE;
5385 else
5386 return;
5387 }
5388
5389 do_ssh1_connection(ssh, in, inlen, pktin);
5390}
5391
5392/*
e5574168 5393 * Utility routine for decoding comma-separated strings in KEXINIT.
5394 */
32874aea 5395static int in_commasep_string(char *needle, char *haystack, int haylen)
5396{
57356d63 5397 int needlen;
5398 if (!needle || !haystack) /* protect against null pointers */
5399 return 0;
5400 needlen = strlen(needle);
e5574168 5401 while (1) {
32874aea 5402 /*
5403 * Is it at the start of the string?
5404 */
5405 if (haylen >= needlen && /* haystack is long enough */
5406 !memcmp(needle, haystack, needlen) && /* initial match */
5407 (haylen == needlen || haystack[needlen] == ',')
5408 /* either , or EOS follows */
5409 )
5410 return 1;
5411 /*
5412 * If not, search for the next comma and resume after that.
5413 * If no comma found, terminate.
5414 */
5415 while (haylen > 0 && *haystack != ',')
5416 haylen--, haystack++;
5417 if (haylen == 0)
5418 return 0;
5419 haylen--, haystack++; /* skip over comma itself */
e5574168 5420 }
5421}
5422
5423/*
b59743d5 5424 * Similar routine for checking whether we have the first string in a list.
5425 */
5426static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5427{
5428 int needlen;
5429 if (!needle || !haystack) /* protect against null pointers */
5430 return 0;
5431 needlen = strlen(needle);
5432 /*
5433 * Is it at the start of the string?
5434 */
5435 if (haylen >= needlen && /* haystack is long enough */
5436 !memcmp(needle, haystack, needlen) && /* initial match */
5437 (haylen == needlen || haystack[needlen] == ',')
5438 /* either , or EOS follows */
5439 )
5440 return 1;
5441 return 0;
5442}
5443
5444
5445/*
2e85c969 5446 * SSH-2 key creation method.
754c0df9 5447 * (Currently assumes 2 lots of any hash are sufficient to generate
5448 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
d39f364a 5449 */
754c0df9 5450#define SSH2_MKKEY_ITERS (2)
b672f405 5451static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
d8baa528 5452 unsigned char *keyspace)
32874aea 5453{
b672f405 5454 const struct ssh_hash *h = ssh->kex->hash;
5455 void *s;
5456 /* First hlen bytes. */
5457 s = h->init();
51470298 5458 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5459 hash_mpint(h, s, K);
5460 h->bytes(s, H, h->hlen);
5461 h->bytes(s, &chr, 1);
5462 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5463 h->final(s, keyspace);
5464 /* Next hlen bytes. */
5465 s = h->init();
51470298 5466 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5467 hash_mpint(h, s, K);
5468 h->bytes(s, H, h->hlen);
5469 h->bytes(s, keyspace, h->hlen);
5470 h->final(s, keyspace + h->hlen);
d39f364a 5471}
5472
5473/*
2e85c969 5474 * Handle the SSH-2 transport layer.
e5574168 5475 */
1c1a7262 5476static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
ff3187f6 5477 struct Packet *pktin)
e5574168 5478{
1c1a7262 5479 unsigned char *in = (unsigned char *)vin;
51470298 5480 struct do_ssh2_transport_state {
30919997 5481 int crLine;
4763c1c2 5482 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
51470298 5483 Bignum p, g, e, f, K;
3dc9a6a7 5484 void *our_kexinit;
5485 int our_kexinitlen;
51470298 5486 int kex_init_value, kex_reply_value;
5487 const struct ssh_mac **maclist;
5488 int nmacs;
5489 const struct ssh2_cipher *cscipher_tobe;
5490 const struct ssh2_cipher *sccipher_tobe;
5491 const struct ssh_mac *csmac_tobe;
5492 const struct ssh_mac *scmac_tobe;
5493 const struct ssh_compress *cscomp_tobe;
5494 const struct ssh_compress *sccomp_tobe;
fae1a71b 5495 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5496 int hostkeylen, siglen, rsakeylen;
51470298 5497 void *hkey; /* actual host key */
fae1a71b 5498 void *rsakey; /* for RSA kex */
754c0df9 5499 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
83e7d008 5500 int n_preferred_kex;
34557659 5501 const struct ssh_kexes *preferred_kex[KEX_MAX];
51470298 5502 int n_preferred_ciphers;
5503 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5504 const struct ssh_compress *preferred_comp;
ab18ccff 5505 int userauth_succeeded; /* for delayed compression */
5506 int pending_compression;
e13bba36 5507 int got_session_id, activated_authconn;
ff3187f6 5508 struct Packet *pktout;
3d9449a1 5509 int dlgret;
5510 int guessok;
4763c1c2 5511 int ignorepkt;
51470298 5512 };
5513 crState(do_ssh2_transport_state);
5514
30919997 5515 crBeginState;
51470298 5516
5517 s->cscipher_tobe = s->sccipher_tobe = NULL;
5518 s->csmac_tobe = s->scmac_tobe = NULL;
5519 s->cscomp_tobe = s->sccomp_tobe = NULL;
5520
e13bba36 5521 s->got_session_id = s->activated_authconn = FALSE;
ab18ccff 5522 s->userauth_succeeded = FALSE;
5523 s->pending_compression = FALSE;
e5574168 5524
e13bba36 5525 /*
5526 * Be prepared to work around the buggy MAC problem.
5527 */
5528 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5529 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5530 else
5531 s->maclist = macs, s->nmacs = lenof(macs);
5532
5533 begin_key_exchange:
acab36bc 5534 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
51470298 5535 {
cc18f256 5536 int i, j, k, commalist_started;
e13bba36 5537
51470298 5538 /*
83e7d008 5539 * Set up the preferred key exchange. (NULL => warn below here)
5540 */
5541 s->n_preferred_kex = 0;
5542 for (i = 0; i < KEX_MAX; i++) {
4a693cfc 5543 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
83e7d008 5544 case KEX_DHGEX:
5545 s->preferred_kex[s->n_preferred_kex++] =
5546 &ssh_diffiehellman_gex;
5547 break;
5548 case KEX_DHGROUP14:
5549 s->preferred_kex[s->n_preferred_kex++] =
5550 &ssh_diffiehellman_group14;
5551 break;
5552 case KEX_DHGROUP1:
5553 s->preferred_kex[s->n_preferred_kex++] =
5554 &ssh_diffiehellman_group1;
5555 break;
fae1a71b 5556 case KEX_RSA:
5557 s->preferred_kex[s->n_preferred_kex++] =
5558 &ssh_rsa_kex;
5559 break;
754c0df9 5560 case KEX_WARN:
83e7d008 5561 /* Flag for later. Don't bother if it's the last in
5562 * the list. */
5563 if (i < KEX_MAX - 1) {
5564 s->preferred_kex[s->n_preferred_kex++] = NULL;
5565 }
5566 break;
5567 }
5568 }
83e7d008 5569
83e7d008 5570 /*
51470298 5571 * Set up the preferred ciphers. (NULL => warn below here)
5572 */
5573 s->n_preferred_ciphers = 0;
5574 for (i = 0; i < CIPHER_MAX; i++) {
4a693cfc 5575 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
51470298 5576 case CIPHER_BLOWFISH:
5577 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5578 break;
5579 case CIPHER_DES:
4a693cfc 5580 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
51470298 5581 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5582 }
5583 break;
5584 case CIPHER_3DES:
5585 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5586 break;
5587 case CIPHER_AES:
5588 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5589 break;
a2add208 5590 case CIPHER_ARCFOUR:
5591 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5592 break;
51470298 5593 case CIPHER_WARN:
5594 /* Flag for later. Don't bother if it's the last in
5595 * the list. */
5596 if (i < CIPHER_MAX - 1) {
5597 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5598 }
5599 break;
ca20bfcf 5600 }
ca20bfcf 5601 }
7591b9ff 5602
e13bba36 5603 /*
5604 * Set up preferred compression.
5605 */
4a693cfc 5606 if (conf_get_int(ssh->conf, CONF_compression))
e13bba36 5607 s->preferred_comp = &ssh_zlib;
5608 else
5609 s->preferred_comp = &ssh_comp_none;
51470298 5610
5611 /*
590f6a5f 5612 * Enable queueing of outgoing auth- or connection-layer
5613 * packets while we are in the middle of a key exchange.
5614 */
5615 ssh->queueing = TRUE;
5616
5617 /*
9442dd57 5618 * Flag that KEX is in progress.
5619 */
5620 ssh->kex_in_progress = TRUE;
5621
5622 /*
51470298 5623 * Construct and send our key exchange packet.
5624 */
ff3187f6 5625 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 5626 for (i = 0; i < 16; i++)
ff3187f6 5627 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 5628 /* List key exchange algorithms. */
ff3187f6 5629 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5630 commalist_started = 0;
5631 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5632 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5633 if (!k) continue; /* warning flag */
34557659 5634 for (j = 0; j < k->nkexes; j++) {
5635 if (commalist_started)
5636 ssh2_pkt_addstring_str(s->pktout, ",");
5637 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5638 commalist_started = 1;
5639 }
32874aea 5640 }
51470298 5641 /* List server host key algorithms. */
ff3187f6 5642 ssh2_pkt_addstring_start(s->pktout);
51470298 5643 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 5644 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 5645 if (i < lenof(hostkey_algs) - 1)
ff3187f6 5646 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 5647 }
cc18f256 5648 /* List encryption algorithms (client->server then server->client). */
5649 for (k = 0; k < 2; k++) {
5650 ssh2_pkt_addstring_start(s->pktout);
5651 commalist_started = 0;
5652 for (i = 0; i < s->n_preferred_ciphers; i++) {
5653 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5654 if (!c) continue; /* warning flag */
5655 for (j = 0; j < c->nciphers; j++) {
5656 if (commalist_started)
5657 ssh2_pkt_addstring_str(s->pktout, ",");
5658 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5659 commalist_started = 1;
5660 }
51470298 5661 }
5662 }
cc18f256 5663 /* List MAC algorithms (client->server then server->client). */
5664 for (j = 0; j < 2; j++) {
5665 ssh2_pkt_addstring_start(s->pktout);
5666 for (i = 0; i < s->nmacs; i++) {
5667 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5668 if (i < s->nmacs - 1)
ff3187f6 5669 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5670 }
5671 }
ab18ccff 5672 /* List client->server compression algorithms,
5673 * then server->client compression algorithms. (We use the
5674 * same set twice.) */
5675 for (j = 0; j < 2; j++) {
5676 ssh2_pkt_addstring_start(s->pktout);
5677 assert(lenof(compressions) > 1);
5678 /* Prefer non-delayed versions */
5679 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5680 /* We don't even list delayed versions of algorithms until
5681 * they're allowed to be used, to avoid a race. See the end of
5682 * this function. */
5683 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
ff3187f6 5684 ssh2_pkt_addstring_str(s->pktout, ",");
ab18ccff 5685 ssh2_pkt_addstring_str(s->pktout,
5686 s->preferred_comp->delayed_name);
f6e0abe2 5687 }
ab18ccff 5688 for (i = 0; i < lenof(compressions); i++) {
5689 const struct ssh_compress *c = compressions[i];
5690 if (c != s->preferred_comp) {
5691 ssh2_pkt_addstring_str(s->pktout, ",");
5692 ssh2_pkt_addstring_str(s->pktout, c->name);
5693 if (s->userauth_succeeded && c->delayed_name) {
5694 ssh2_pkt_addstring_str(s->pktout, ",");
5695 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5696 }
5697 }
f6e0abe2 5698 }
51470298 5699 }
5700 /* List client->server languages. Empty list. */
ff3187f6 5701 ssh2_pkt_addstring_start(s->pktout);
51470298 5702 /* List server->client languages. Empty list. */
ff3187f6 5703 ssh2_pkt_addstring_start(s->pktout);
51470298 5704 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5705 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5706 /* Reserved. */
ff3187f6 5707 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5708 }
0db56f73 5709
3dc9a6a7 5710 s->our_kexinitlen = s->pktout->length - 5;
5711 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5712 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
0db56f73 5713
590f6a5f 5714 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5715
ff3187f6 5716 if (!pktin)
5717 crWaitUntil(pktin);
e5574168 5718
5719 /*
5720 * Now examine the other side's KEXINIT to see what we're up
5721 * to.
5722 */
51470298 5723 {
4763c1c2 5724 char *str, *preferred;
3d9449a1 5725 int i, j, len;
51470298 5726
ff3187f6 5727 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5728 bombout(("expected key exchange packet from server"));
7ffdbc1a 5729 crStop(0);
32874aea 5730 }
51470298 5731 ssh->kex = NULL;
5732 ssh->hostkey = NULL;
5733 s->cscipher_tobe = NULL;
5734 s->sccipher_tobe = NULL;
5735 s->csmac_tobe = NULL;
5736 s->scmac_tobe = NULL;
5737 s->cscomp_tobe = NULL;
5738 s->sccomp_tobe = NULL;
4763c1c2 5739 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5740
ff3187f6 5741 pktin->savedpos += 16; /* skip garbage cookie */
5742 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4763c1c2 5743
5744 preferred = NULL;
83e7d008 5745 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5746 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5747 if (!k) {
4763c1c2 5748 s->warn_kex = TRUE;
5749 } else {
34557659 5750 for (j = 0; j < k->nkexes; j++) {
5751 if (!preferred) preferred = k->list[j]->name;
5752 if (in_commasep_string(k->list[j]->name, str, len)) {
5753 ssh->kex = k->list[j];
5754 break;
5755 }
5756 }
83e7d008 5757 }
4763c1c2 5758 if (ssh->kex)
51470298 5759 break;
32874aea 5760 }
83e7d008 5761 if (!ssh->kex) {
5762 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5763 str ? str : "(null)"));
5764 crStop(0);
5765 }
b59743d5 5766 /*
5767 * Note that the server's guess is considered wrong if it doesn't match
5768 * the first algorithm in our list, even if it's still the algorithm
5769 * we end up using.
5770 */
4763c1c2 5771 s->guessok = first_in_commasep_string(preferred, str, len);
ff3187f6 5772 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5773 for (i = 0; i < lenof(hostkey_algs); i++) {
5774 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5775 ssh->hostkey = hostkey_algs[i];
5776 break;
5777 }
5778 }
fc40b431 5779 if (!ssh->hostkey) {
5780 bombout(("Couldn't agree a host key algorithm (available: %s)",
5781 str ? str : "(null)"));
5782 crStop(0);
5783 }
5784
3d9449a1 5785 s->guessok = s->guessok &&
b59743d5 5786 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5787 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5788 for (i = 0; i < s->n_preferred_ciphers; i++) {
5789 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5790 if (!c) {
4763c1c2 5791 s->warn_cscipher = TRUE;
51470298 5792 } else {
5793 for (j = 0; j < c->nciphers; j++) {
5794 if (in_commasep_string(c->list[j]->name, str, len)) {
5795 s->cscipher_tobe = c->list[j];
5796 break;
5797 }
ca20bfcf 5798 }
32874aea 5799 }
4763c1c2 5800 if (s->cscipher_tobe)
51470298 5801 break;
32874aea 5802 }
51470298 5803 if (!s->cscipher_tobe) {
6b5cf8b4 5804 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5805 str ? str : "(null)"));
7ffdbc1a 5806 crStop(0);
ca20bfcf 5807 }
0ef8f407 5808
ff3187f6 5809 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5810 for (i = 0; i < s->n_preferred_ciphers; i++) {
5811 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5812 if (!c) {
4763c1c2 5813 s->warn_sccipher = TRUE;
51470298 5814 } else {
5815 for (j = 0; j < c->nciphers; j++) {
5816 if (in_commasep_string(c->list[j]->name, str, len)) {
5817 s->sccipher_tobe = c->list[j];
5818 break;
5819 }
ca20bfcf 5820 }
32874aea 5821 }
4763c1c2 5822 if (s->sccipher_tobe)
51470298 5823 break;
32874aea 5824 }
51470298 5825 if (!s->sccipher_tobe) {
6b5cf8b4 5826 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5827 str ? str : "(null)"));
7ffdbc1a 5828 crStop(0);
ca20bfcf 5829 }
0ef8f407 5830
ff3187f6 5831 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5832 for (i = 0; i < s->nmacs; i++) {
5833 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5834 s->csmac_tobe = s->maclist[i];
5835 break;
5836 }
32874aea 5837 }
ff3187f6 5838 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5839 for (i = 0; i < s->nmacs; i++) {
5840 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5841 s->scmac_tobe = s->maclist[i];
5842 break;
5843 }
32874aea 5844 }
ff3187f6 5845 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5846 for (i = 0; i < lenof(compressions) + 1; i++) {
5847 const struct ssh_compress *c =
5848 i == 0 ? s->preferred_comp : compressions[i - 1];
5849 if (in_commasep_string(c->name, str, len)) {
5850 s->cscomp_tobe = c;
5851 break;
ab18ccff 5852 } else if (in_commasep_string(c->delayed_name, str, len)) {
5853 if (s->userauth_succeeded) {
5854 s->cscomp_tobe = c;
5855 break;
5856 } else {
5857 s->pending_compression = TRUE; /* try this later */
5858 }
51470298 5859 }
32874aea 5860 }
ff3187f6 5861 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5862 for (i = 0; i < lenof(compressions) + 1; i++) {
5863 const struct ssh_compress *c =
5864 i == 0 ? s->preferred_comp : compressions[i - 1];
5865 if (in_commasep_string(c->name, str, len)) {
5866 s->sccomp_tobe = c;
5867 break;
ab18ccff 5868 } else if (in_commasep_string(c->delayed_name, str, len)) {
5869 if (s->userauth_succeeded) {
5870 s->sccomp_tobe = c;
5871 break;
5872 } else {
5873 s->pending_compression = TRUE; /* try this later */
5874 }
51470298 5875 }
32874aea 5876 }
ab18ccff 5877 if (s->pending_compression) {
5878 logevent("Server supports delayed compression; "
5879 "will try this later");
5880 }
b59743d5 5881 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5882 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
4763c1c2 5883 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5884
5885 if (s->warn_kex) {
5886 ssh_set_frozen(ssh, 1);
5887 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5888 ssh->kex->name,
5889 ssh_dialog_callback, ssh);
5890 if (s->dlgret < 0) {
5891 do {
5892 crReturn(0);
5893 if (pktin) {
5894 bombout(("Unexpected data from server while"
5895 " waiting for user response"));
5896 crStop(0);
5897 }
5898 } while (pktin || inlen > 0);
5899 s->dlgret = ssh->user_response;
5900 }
5901 ssh_set_frozen(ssh, 0);
5902 if (s->dlgret == 0) {
9e296bfa 5903 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5904 0, TRUE);
a5a6f839 5905 crStop(0);
4763c1c2 5906 }
5907 }
5908
5909 if (s->warn_cscipher) {
5910 ssh_set_frozen(ssh, 1);
5911 s->dlgret = askalg(ssh->frontend,
5912 "client-to-server cipher",
5913 s->cscipher_tobe->name,
5914 ssh_dialog_callback, ssh);
5915 if (s->dlgret < 0) {
5916 do {
5917 crReturn(0);
5918 if (pktin) {
5919 bombout(("Unexpected data from server while"
5920 " waiting for user response"));
5921 crStop(0);
5922 }
5923 } while (pktin || inlen > 0);
5924 s->dlgret = ssh->user_response;
5925 }
5926 ssh_set_frozen(ssh, 0);
5927 if (s->dlgret == 0) {
9e296bfa 5928 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5929 0, TRUE);
a5a6f839 5930 crStop(0);
4763c1c2 5931 }
5932 }
5933
5934 if (s->warn_sccipher) {
5935 ssh_set_frozen(ssh, 1);
5936 s->dlgret = askalg(ssh->frontend,
5937 "server-to-client cipher",
5938 s->sccipher_tobe->name,
5939 ssh_dialog_callback, ssh);
5940 if (s->dlgret < 0) {
5941 do {
5942 crReturn(0);
5943 if (pktin) {
5944 bombout(("Unexpected data from server while"
5945 " waiting for user response"));
5946 crStop(0);
5947 }
5948 } while (pktin || inlen > 0);
5949 s->dlgret = ssh->user_response;
5950 }
5951 ssh_set_frozen(ssh, 0);
5952 if (s->dlgret == 0) {
9e296bfa 5953 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5954 0, TRUE);
a5a6f839 5955 crStop(0);
4763c1c2 5956 }
5957 }
5958
b672f405 5959 ssh->exhash = ssh->kex->hash->init();
5960 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5961 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5962 hash_string(ssh->kex->hash, ssh->exhash,
5963 s->our_kexinit, s->our_kexinitlen);
3dc9a6a7 5964 sfree(s->our_kexinit);
5965 if (pktin->length > 5)
b672f405 5966 hash_string(ssh->kex->hash, ssh->exhash,
5967 pktin->data + 5, pktin->length - 5);
3dc9a6a7 5968
4763c1c2 5969 if (s->ignorepkt) /* first_kex_packet_follows */
b59743d5 5970 crWaitUntil(pktin); /* Ignore packet */
e5574168 5971 }
e5574168 5972
fae1a71b 5973 if (ssh->kex->main_type == KEXTYPE_DH) {
30774ba3 5974 /*
5975 * Work out the number of bits of key we will need from the
5976 * key exchange. We start with the maximum key length of
5977 * either cipher...
5978 */
5979 {
5980 int csbits, scbits;
5981
5982 csbits = s->cscipher_tobe->keylen;
5983 scbits = s->sccipher_tobe->keylen;
5984 s->nbits = (csbits > scbits ? csbits : scbits);
5985 }
5986 /* The keys only have hlen-bit entropy, since they're based on
5987 * a hash. So cap the key size at hlen bits. */
5988 if (s->nbits > ssh->kex->hash->hlen * 8)
5989 s->nbits = ssh->kex->hash->hlen * 8;
5990
5991 /*
5992 * If we're doing Diffie-Hellman group exchange, start by
5993 * requesting a group.
5994 */
5995 if (!ssh->kex->pdata) {
5996 logevent("Doing Diffie-Hellman group exchange");
acab36bc 5997 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
30774ba3 5998 /*
5999 * Work out how big a DH group we will need to allow that
6000 * much data.
6001 */
6002 s->pbits = 512 << ((s->nbits - 1) / 64);
6003 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6004 ssh2_pkt_adduint32(s->pktout, s->pbits);
6005 ssh2_pkt_send_noqueue(ssh, s->pktout);
6006
6007 crWaitUntil(pktin);
6008 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6009 bombout(("expected key exchange group packet from server"));
6010 crStop(0);
6011 }
6012 s->p = ssh2_pkt_getmp(pktin);
6013 s->g = ssh2_pkt_getmp(pktin);
6014 if (!s->p || !s->g) {
6015 bombout(("unable to read mp-ints from incoming group packet"));
6016 crStop(0);
6017 }
6018 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6019 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6020 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6021 } else {
acab36bc 6022 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
30774ba3 6023 ssh->kex_ctx = dh_setup_group(ssh->kex);
6024 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6025 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6026 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6027 ssh->kex->groupname);
6028 }
e5574168 6029
30774ba3 6030 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6031 ssh->kex->hash->text_name);
6032 /*
6033 * Now generate and send e for Diffie-Hellman.
6034 */
6035 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6036 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6037 s->pktout = ssh2_pkt_init(s->kex_init_value);
6038 ssh2_pkt_addmp(s->pktout, s->e);
6039 ssh2_pkt_send_noqueue(ssh, s->pktout);
6040
6041 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6042 crWaitUntil(pktin);
6043 if (pktin->type != s->kex_reply_value) {
6044 bombout(("expected key exchange reply packet from server"));
6045 crStop(0);
6046 }
6047 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6048 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6049 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6050 s->f = ssh2_pkt_getmp(pktin);
6051 if (!s->f) {
6052 bombout(("unable to parse key exchange reply packet"));
6053 crStop(0);
6054 }
6055 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 6056
30774ba3 6057 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 6058
30774ba3 6059 /* We assume everything from now on will be quick, and it might
6060 * involve user interaction. */
6061 set_busy_status(ssh->frontend, BUSY_NOT);
755e0524 6062
30774ba3 6063 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6064 if (!ssh->kex->pdata) {
6065 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6066 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6067 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6068 }
6069 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6070 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6071
6072 dh_cleanup(ssh->kex_ctx);
6073 freebn(s->f);
6074 if (!ssh->kex->pdata) {
6075 freebn(s->g);
6076 freebn(s->p);
6077 }
fae1a71b 6078 } else {
6079 logeventf(ssh, "Doing RSA key exchange with hash %s",
6080 ssh->kex->hash->text_name);
acab36bc 6081 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
fae1a71b 6082 /*
6083 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6084 * from the server.
6085 */
6086 crWaitUntil(pktin);
6087 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6088 bombout(("expected RSA public key packet from server"));
6089 crStop(0);
6090 }
6091
6092 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6093 hash_string(ssh->kex->hash, ssh->exhash,
6094 s->hostkeydata, s->hostkeylen);
6095 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6096
6097 {
6098 char *keydata;
6099 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6100 s->rsakeydata = snewn(s->rsakeylen, char);
6101 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6102 }
6103
6104 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6105 if (!s->rsakey) {
6106 sfree(s->rsakeydata);
6107 bombout(("unable to parse RSA public key from server"));
6108 crStop(0);
6109 }
6110
6111 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6112
6113 /*
6114 * Next, set up a shared secret K, of precisely KLEN -
6115 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6116 * RSA key modulus and HLEN is the bit length of the hash
6117 * we're using.
6118 */
6119 {
6120 int klen = ssh_rsakex_klen(s->rsakey);
6121 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6122 int i, byte = 0;
6123 unsigned char *kstr1, *kstr2, *outstr;
6124 int kstr1len, kstr2len, outstrlen;
6125
6126 s->K = bn_power_2(nbits - 1);
6127
6128 for (i = 0; i < nbits; i++) {
6129 if ((i & 7) == 0) {
6130 byte = random_byte();
6131 }
6132 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6133 }
6134
6135 /*
6136 * Encode this as an mpint.
6137 */
6138 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6139 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6140 PUT_32BIT(kstr2, kstr1len);
6141 memcpy(kstr2 + 4, kstr1, kstr1len);
6142
6143 /*
6144 * Encrypt it with the given RSA key.
6145 */
6146 outstrlen = (klen + 7) / 8;
6147 outstr = snewn(outstrlen, unsigned char);
6148 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6149 outstr, outstrlen, s->rsakey);
6150
6151 /*
6152 * And send it off in a return packet.
6153 */
6154 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6155 ssh2_pkt_addstring_start(s->pktout);
7108a872 6156 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
fae1a71b 6157 ssh2_pkt_send_noqueue(ssh, s->pktout);
6158
6159 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6160
6161 sfree(kstr2);
6162 sfree(kstr1);
6163 sfree(outstr);
6164 }
6165
6166 ssh_rsakex_freekey(s->rsakey);
6167
6168 crWaitUntil(pktin);
6169 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6170 sfree(s->rsakeydata);
6171 bombout(("expected signature packet from server"));
6172 crStop(0);
6173 }
6174
6175 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6176
6177 sfree(s->rsakeydata);
6178 }
6179
b672f405 6180 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6181 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6182 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
e5574168 6183
fabd1805 6184 ssh->kex_ctx = NULL;
3709bfe9 6185
7cca0d81 6186#if 0
765c4200 6187 debug(("Exchange hash is:\n"));
b672f405 6188 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7cca0d81 6189#endif
6190
51470298 6191 if (!s->hkey ||
6192 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
b672f405 6193 (char *)s->exchange_hash,
6194 ssh->kex->hash->hlen)) {
6b5cf8b4 6195 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 6196 crStop(0);
8d5de777 6197 }
e5574168 6198
6199 /*
7cca0d81 6200 * Authenticate remote host: verify host key. (We've already
6201 * checked the signature of the exchange hash.)
e5574168 6202 */
51470298 6203 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6204 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 6205 ssh_set_frozen(ssh, 1);
6206 s->dlgret = verify_ssh_host_key(ssh->frontend,
6207 ssh->savedhost, ssh->savedport,
6208 ssh->hostkey->keytype, s->keystr,
6209 s->fingerprint,
6210 ssh_dialog_callback, ssh);
6211 if (s->dlgret < 0) {
6212 do {
6213 crReturn(0);
6214 if (pktin) {
6215 bombout(("Unexpected data from server while waiting"
6216 " for user host key response"));
6217 crStop(0);
6218 }
6219 } while (pktin || inlen > 0);
6220 s->dlgret = ssh->user_response;
6221 }
6222 ssh_set_frozen(ssh, 0);
6223 if (s->dlgret == 0) {
9e296bfa 6224 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6225 0, TRUE);
3d9449a1 6226 crStop(0);
6227 }
e13bba36 6228 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 6229 logevent("Host key fingerprint is:");
51470298 6230 logevent(s->fingerprint);
5e0d7cb8 6231 }
51470298 6232 sfree(s->fingerprint);
6233 sfree(s->keystr);
6234 ssh->hostkey->freekey(s->hkey);
d39f364a 6235
6236 /*
9442dd57 6237 * The exchange hash from the very first key exchange is also
6238 * the session id, used in session key construction and
6239 * authentication.
6240 */
e13bba36 6241 if (!s->got_session_id) {
b672f405 6242 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
9442dd57 6243 memcpy(ssh->v2_session_id, s->exchange_hash,
6244 sizeof(s->exchange_hash));
b672f405 6245 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6052bb76 6246 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
e13bba36 6247 s->got_session_id = TRUE;
6248 }
9442dd57 6249
6250 /*
7cca0d81 6251 * Send SSH2_MSG_NEWKEYS.
d39f364a 6252 */
ff3187f6 6253 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 6254 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 6255 ssh->outgoing_data_size = 0; /* start counting from here */
6256
6257 /*
6258 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 6259 * client-to-server session keys.
9442dd57 6260 */
6261 if (ssh->cs_cipher_ctx)
6262 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6263 ssh->cscipher = s->cscipher_tobe;
6264 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6265
6266 if (ssh->cs_mac_ctx)
6267 ssh->csmac->free_context(ssh->cs_mac_ctx);
6268 ssh->csmac = s->csmac_tobe;
6269 ssh->cs_mac_ctx = ssh->csmac->make_context();
6270
6271 if (ssh->cs_comp_ctx)
6272 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6273 ssh->cscomp = s->cscomp_tobe;
6274 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6275
6276 /*
6277 * Set IVs on client-to-server keys. Here we use the exchange
6278 * hash from the _first_ key exchange.
6279 */
6280 {
754c0df9 6281 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6282 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6283 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
754c0df9 6284 assert((ssh->cscipher->keylen+7) / 8 <=
6285 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6286 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
b672f405 6287 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
754c0df9 6288 assert(ssh->cscipher->blksize <=
6289 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6290 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
b672f405 6291 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
754c0df9 6292 assert(ssh->csmac->len <=
6293 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6294 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
dfb88efd 6295 smemclr(keyspace, sizeof(keyspace));
9442dd57 6296 }
6297
6298 logeventf(ssh, "Initialised %.200s client->server encryption",
6299 ssh->cscipher->text_name);
6300 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6301 ssh->csmac->text_name);
6302 if (ssh->cscomp->text_name)
6303 logeventf(ssh, "Initialised %s compression",
6304 ssh->cscomp->text_name);
590f6a5f 6305
6306 /*
6307 * Now our end of the key exchange is complete, we can send all
6308 * our queued higher-layer packets.
6309 */
6310 ssh->queueing = FALSE;
6311 ssh2_pkt_queuesend(ssh);
d39f364a 6312
6313 /*
8406eaf9 6314 * Expect SSH2_MSG_NEWKEYS from server.
6315 */
ff3187f6 6316 crWaitUntil(pktin);
6317 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 6318 bombout(("expected new-keys packet from server"));
7ffdbc1a 6319 crStop(0);
8406eaf9 6320 }
9442dd57 6321 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 6322
6323 /*
9442dd57 6324 * We've seen server NEWKEYS, so create and initialise
6325 * server-to-client session keys.
d39f364a 6326 */
371e569c 6327 if (ssh->sc_cipher_ctx)
6328 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 6329 ssh->sccipher = s->sccipher_tobe;
371e569c 6330 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 6331
e0e1a00d 6332 if (ssh->sc_mac_ctx)
6333 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 6334 ssh->scmac = s->scmac_tobe;
e0e1a00d 6335 ssh->sc_mac_ctx = ssh->scmac->make_context();
6336
5366aed8 6337 if (ssh->sc_comp_ctx)
6338 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 6339 ssh->sccomp = s->sccomp_tobe;
5366aed8 6340 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6341
d39f364a 6342 /*
9442dd57 6343 * Set IVs on server-to-client keys. Here we use the exchange
6344 * hash from the _first_ key exchange.
d39f364a 6345 */
51470298 6346 {
754c0df9 6347 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6348 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6349 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
754c0df9 6350 assert((ssh->sccipher->keylen+7) / 8 <=
6351 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6352 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
b672f405 6353 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
754c0df9 6354 assert(ssh->sccipher->blksize <=
6355 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6356 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
b672f405 6357 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
754c0df9 6358 assert(ssh->scmac->len <=
6359 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
e0e1a00d 6360 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
dfb88efd 6361 smemclr(keyspace, sizeof(keyspace));
51470298 6362 }
57356d63 6363 logeventf(ssh, "Initialised %.200s server->client encryption",
6364 ssh->sccipher->text_name);
6c135243 6365 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6366 ssh->scmac->text_name);
57356d63 6367 if (ssh->sccomp->text_name)
6368 logeventf(ssh, "Initialised %s decompression",
6369 ssh->sccomp->text_name);
9442dd57 6370
6371 /*
fae1a71b 6372 * Free shared secret.
9442dd57 6373 */
679539d7 6374 freebn(s->K);
d39f364a 6375
033b4cef 6376 /*
e13bba36 6377 * Key exchange is over. Loop straight back round if we have a
6378 * deferred rekey reason.
6379 */
6380 if (ssh->deferred_rekey_reason) {
6381 logevent(ssh->deferred_rekey_reason);
6382 pktin = NULL;
6383 ssh->deferred_rekey_reason = NULL;
6384 goto begin_key_exchange;
6385 }
6386
6387 /*
6388 * Otherwise, schedule a timer for our next rekey.
9442dd57 6389 */
6390 ssh->kex_in_progress = FALSE;
e6c1536e 6391 ssh->last_rekey = GETTICKCOUNT();
4a693cfc 6392 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6393 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
d57f70af 6394 ssh2_timer, ssh);
e13bba36 6395
9442dd57 6396 /*
7cca0d81 6397 * Now we're encrypting. Begin returning 1 to the protocol main
6398 * function so that other things can run on top of the
6399 * transport. If we ever see a KEXINIT, we must go back to the
6400 * start.
9442dd57 6401 *
6402 * We _also_ go back to the start if we see pktin==NULL and
ab18ccff 6403 * inlen negative, because this is a special signal meaning
9442dd57 6404 * `initiate client-driven rekey', and `in' contains a message
6405 * giving the reason for the rekey.
ab18ccff 6406 *
6407 * inlen==-1 means always initiate a rekey;
6408 * inlen==-2 means that userauth has completed successfully and
6409 * we should consider rekeying (for delayed compression).
033b4cef 6410 */
9442dd57 6411 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
ab18ccff 6412 (!pktin && inlen < 0))) {
f382c87d 6413 wait_for_rekey:
bc074147 6414 if (!ssh->protocol_initial_phase_done) {
6415 ssh->protocol_initial_phase_done = TRUE;
6416 /*
6417 * Allow authconn to initialise itself.
6418 */
6419 do_ssh2_authconn(ssh, NULL, 0, NULL);
6420 }
32874aea 6421 crReturn(1);
e96adf72 6422 }
9442dd57 6423 if (pktin) {
6424 logevent("Server initiated key re-exchange");
6425 } else {
ab18ccff 6426 if (inlen == -2) {
6427 /*
6428 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6429 * delayed compression, if it's available.
6430 *
6431 * draft-miller-secsh-compression-delayed-00 says that you
6432 * negotiate delayed compression in the first key exchange, and
6433 * both sides start compressing when the server has sent
6434 * USERAUTH_SUCCESS. This has a race condition -- the server
6435 * can't know when the client has seen it, and thus which incoming
6436 * packets it should treat as compressed.
6437 *
6438 * Instead, we do the initial key exchange without offering the
6439 * delayed methods, but note if the server offers them; when we
6440 * get here, if a delayed method was available that was higher
6441 * on our list than what we got, we initiate a rekey in which we
6442 * _do_ list the delayed methods (and hopefully get it as a
6443 * result). Subsequent rekeys will do the same.
6444 */
6445 assert(!s->userauth_succeeded); /* should only happen once */
6446 s->userauth_succeeded = TRUE;
6447 if (!s->pending_compression)
6448 /* Can't see any point rekeying. */
6449 goto wait_for_rekey; /* this is utterly horrid */
6450 /* else fall through to rekey... */
6451 s->pending_compression = FALSE;
6452 }
f382c87d 6453 /*
ab18ccff 6454 * Now we've decided to rekey.
6455 *
f382c87d 6456 * Special case: if the server bug is set that doesn't
6457 * allow rekeying, we give a different log message and
6458 * continue waiting. (If such a server _initiates_ a rekey,
6459 * we process it anyway!)
6460 */
6461 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6462 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6463 (char *)in);
6464 /* Reset the counters, so that at least this message doesn't
6465 * hit the event log _too_ often. */
6466 ssh->outgoing_data_size = 0;
6467 ssh->incoming_data_size = 0;
4a693cfc 6468 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
f382c87d 6469 ssh->next_rekey =
4a693cfc 6470 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
f382c87d 6471 ssh2_timer, ssh);
6472 }
ab18ccff 6473 goto wait_for_rekey; /* this is still utterly horrid */
f382c87d 6474 } else {
6475 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 6476 }
9442dd57 6477 }
7cca0d81 6478 goto begin_key_exchange;
e5574168 6479
6480 crFinish(1);
6481}
6482
7cca0d81 6483/*
2e85c969 6484 * Add data to an SSH-2 channel output buffer.
783415f8 6485 */
32874aea 6486static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6487 int len)
6488{
5471d09a 6489 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 6490}
6491
6492/*
2e85c969 6493 * Attempt to send data on an SSH-2 channel.
783415f8 6494 */
5471d09a 6495static int ssh2_try_send(struct ssh_channel *c)
32874aea 6496{
51470298 6497 Ssh ssh = c->ssh;
ff3187f6 6498 struct Packet *pktout;
bc06669b 6499 int ret;
51470298 6500
5471d09a 6501 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6502 int len;
6503 void *data;
6504 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6505 if ((unsigned)len > c->v.v2.remwindow)
6506 len = c->v.v2.remwindow;
6507 if ((unsigned)len > c->v.v2.remmaxpkt)
6508 len = c->v.v2.remmaxpkt;
ff3187f6 6509 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6510 ssh2_pkt_adduint32(pktout, c->remoteid);
ff3187f6 6511 ssh2_pkt_addstring_start(pktout);
a2724fba 6512 dont_log_data(ssh, pktout, PKTLOG_OMIT);
ff3187f6 6513 ssh2_pkt_addstring_data(pktout, data, len);
6514 end_log_omission(ssh, pktout);
6515 ssh2_pkt_send(ssh, pktout);
5471d09a 6516 bufchain_consume(&c->v.v2.outbuffer, len);
6517 c->v.v2.remwindow -= len;
6518 }
6519
6520 /*
6521 * After having sent as much data as we can, return the amount
6522 * still buffered.
6523 */
bc06669b 6524 ret = bufchain_size(&c->v.v2.outbuffer);
6525
6526 /*
6527 * And if there's no data pending but we need to send an EOF, send
6528 * it.
6529 */
6530 if (!ret && c->pending_eof)
6531 ssh_channel_try_eof(c);
6532
6533 return ret;
5471d09a 6534}
6535
78280721 6536static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
1bfc7e93 6537{
6538 int bufsize;
bc06669b 6539 if (c->closes & CLOSES_SENT_EOF)
6540 return; /* don't send on channels we've EOFed */
1bfc7e93 6541 bufsize = ssh2_try_send(c);
6542 if (bufsize == 0) {
6543 switch (c->type) {
6544 case CHAN_MAINSESSION:
6545 /* stdin need not receive an unthrottle
6546 * notification since it will be polled */
6547 break;
6548 case CHAN_X11:
6549 x11_unthrottle(c->u.x11.s);
6550 break;
6551 case CHAN_AGENT:
6552 /* agent sockets are request/response and need no
6553 * buffer management */
6554 break;
6555 case CHAN_SOCKDATA:
6556 pfd_unthrottle(c->u.pfd.s);
6557 break;
6558 }
6559 }
6560}
6561
5471d09a 6562/*
94bdfe40 6563 * Set up most of a new ssh_channel for SSH-2.
6564 */
6565static void ssh2_channel_init(struct ssh_channel *c)
6566{
6567 Ssh ssh = c->ssh;
6568 c->localid = alloc_channel_id(ssh);
6569 c->closes = 0;
bc06669b 6570 c->pending_eof = FALSE;
94bdfe40 6571 c->throttling_conn = FALSE;
6572 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
4a693cfc 6573 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
39d830e4 6574 c->v.v2.chanreq_head = NULL;
94bdfe40 6575 c->v.v2.throttle_state = UNTHROTTLED;
6576 bufchain_init(&c->v.v2.outbuffer);
6577}
6578
6579/*
39d830e4 6580 * CHANNEL_FAILURE doesn't come with any indication of what message
6581 * caused it, so we have to keep track of the outstanding
6582 * CHANNEL_REQUESTs ourselves.
6583 */
6584static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
6585 cchandler_fn_t handler, void *ctx)
6586{
6587 struct outstanding_channel_request *ocr =
6588 snew(struct outstanding_channel_request);
6589
3620f307 6590 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
39d830e4 6591 ocr->handler = handler;
6592 ocr->ctx = ctx;
6593 ocr->next = NULL;
6594 if (!c->v.v2.chanreq_head)
6595 c->v.v2.chanreq_head = ocr;
6596 else
6597 c->v.v2.chanreq_tail->next = ocr;
6598 c->v.v2.chanreq_tail = ocr;
6599}
6600
6601/*
134f5ece 6602 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6603 * NULL then a reply will be requested and the handler will be called
6604 * when it arrives. The returned packet is ready to have any
6605 * request-specific data added and be sent. Note that if a handler is
6606 * provided, it's essential that the request actually be sent.
3620f307 6607 *
6608 * The handler will usually be passed the response packet in pktin.
6609 * If pktin is NULL, this means that no reply will ever be forthcoming
6610 * (e.g. because the entire connection is being destroyed) and the
6611 * handler should free any storage it's holding.
134f5ece 6612 */
6613static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
6614 cchandler_fn_t handler, void *ctx)
6615{
6616 struct Packet *pktout;
6617
3620f307 6618 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
134f5ece 6619 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6620 ssh2_pkt_adduint32(pktout, c->remoteid);
6621 ssh2_pkt_addstring(pktout, type);
6622 ssh2_pkt_addbool(pktout, handler != NULL);
6623 if (handler != NULL)
6624 ssh2_queue_chanreq_handler(c, handler, ctx);
6625 return pktout;
6626}
6627
6628/*
2e85c969 6629 * Potentially enlarge the window on an SSH-2 channel.
5471d09a 6630 */
39d830e4 6631static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
6632 void *);
9fca3f8c 6633static void ssh2_set_window(struct ssh_channel *c, int newwin)
5471d09a 6634{
51470298 6635 Ssh ssh = c->ssh;
6636
6b69f42e 6637 /*
bc06669b 6638 * Never send WINDOW_ADJUST for a channel that the remote side has
6639 * already sent EOF on; there's no point, since it won't be
beff003a 6640 * sending any more data anyway. Ditto if _we've_ already sent
6641 * CLOSE.
6b69f42e 6642 */
beff003a 6643 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6b69f42e 6644 return;
6645
d252310a 6646 /*
c9739dba 6647 * If the remote end has a habit of ignoring maxpkt, limit the
6648 * window so that it has no choice (assuming it doesn't ignore the
6649 * window as well).
6650 */
6651 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6652 newwin = OUR_V2_MAXPKT;
c9739dba 6653
6654 /*
d252310a 6655 * Only send a WINDOW_ADJUST if there's significantly more window
6656 * available than the other end thinks there is. This saves us
6657 * sending a WINDOW_ADJUST for every character in a shell session.
6658 *
6659 * "Significant" is arbitrarily defined as half the window size.
6660 */
3361b80a 6661 if (newwin / 2 >= c->v.v2.locwindow) {
ff3187f6 6662 struct Packet *pktout;
39d830e4 6663 unsigned *up;
ff3187f6 6664
0e443c99 6665 /*
6666 * In order to keep track of how much window the client
6667 * actually has available, we'd like it to acknowledge each
6668 * WINDOW_ADJUST. We can't do that directly, so we accompany
6669 * it with a CHANNEL_REQUEST that has to be acknowledged.
6670 *
6671 * This is only necessary if we're opening the window wide.
6672 * If we're not, then throughput is being constrained by
6673 * something other than the maximum window size anyway.
0e443c99 6674 */
6675 if (newwin == c->v.v2.locmaxwin &&
2e0aae4f 6676 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
39d830e4 6677 up = snew(unsigned);
6678 *up = newwin - c->v.v2.locwindow;
134f5ece 6679 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
6680 ssh2_handle_winadj_response, up);
6681 ssh2_pkt_send(ssh, pktout);
6682
0e443c99 6683 if (c->v.v2.throttle_state != UNTHROTTLED)
6684 c->v.v2.throttle_state = UNTHROTTLING;
6685 } else {
6686 /* Pretend the WINDOW_ADJUST was acked immediately. */
6687 c->v.v2.remlocwin = newwin;
6688 c->v.v2.throttle_state = THROTTLED;
6689 }
ff3187f6 6690 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6691 ssh2_pkt_adduint32(pktout, c->remoteid);
6692 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6693 ssh2_pkt_send(ssh, pktout);
5471d09a 6694 c->v.v2.locwindow = newwin;
783415f8 6695 }
6696}
6697
e223b7c7 6698/*
6699 * Find the channel associated with a message. If there's no channel,
6700 * or it's not properly open, make a noise about it and return NULL.
6701 */
6702static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6703{
6704 unsigned localid = ssh_pkt_getuint32(pktin);
6705 struct ssh_channel *c;
6706
6707 c = find234(ssh->channels, &localid, ssh_channelfind);
6708 if (!c ||
6709 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6710 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6711 char *buf = dupprintf("Received %s for %s channel %u",
6712 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6713 pktin->type),
6714 c ? "half-open" : "nonexistent", localid);
6715 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6716 sfree(buf);
6717 return NULL;
6718 }
6719 return c;
6720}
6721
39d830e4 6722static void ssh2_handle_winadj_response(struct ssh_channel *c,
6723 struct Packet *pktin, void *ctx)
e030765f 6724{
39d830e4 6725 unsigned *sizep = ctx;
6726
6727 /*
6728 * Winadj responses should always be failures. However, at least
6729 * one server ("boks_sshd") is known to return SUCCESS for channel
6730 * requests it's never heard of, such as "winadj@putty". Raised
6731 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6732 * life, we don't worry about what kind of response we got.
6733 */
6734
6735 c->v.v2.remlocwin += *sizep;
6736 sfree(sizep);
e030765f 6737 /*
6738 * winadj messages are only sent when the window is fully open, so
6739 * if we get an ack of one, we know any pending unthrottle is
6740 * complete.
6741 */
6742 if (c->v.v2.throttle_state == UNTHROTTLING)
6743 c->v.v2.throttle_state = UNTHROTTLED;
e030765f 6744}
6745
39d830e4 6746static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
837d6ba6 6747{
39d830e4 6748 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
6749 struct outstanding_channel_request *ocr;
837d6ba6 6750
39d830e4 6751 if (!c) return;
6752 ocr = c->v.v2.chanreq_head;
6753 if (!ocr) {
6754 ssh2_msg_unexpected(ssh, pktin);
837d6ba6 6755 return;
39d830e4 6756 }
6757 ocr->handler(c, pktin, ocr->ctx);
6758 c->v.v2.chanreq_head = ocr->next;
6759 sfree(ocr);
0e443c99 6760 /*
39d830e4 6761 * We may now initiate channel-closing procedures, if that
6762 * CHANNEL_REQUEST was the last thing outstanding before we send
6763 * CHANNEL_CLOSE.
0e443c99 6764 */
39d830e4 6765 ssh2_channel_check_close(c);
0e443c99 6766}
6767
51df0ab5 6768static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 6769{
b09eaa88 6770 struct ssh_channel *c;
e223b7c7 6771 c = ssh2_channel_msg(ssh, pktin);
6772 if (!c)
6773 return;
bc06669b 6774 if (!(c->closes & CLOSES_SENT_EOF)) {
b09eaa88 6775 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
78280721 6776 ssh2_try_send_and_unthrottle(ssh, c);
1bfc7e93 6777 }
b09eaa88 6778}
6779
51df0ab5 6780static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6781{
6782 char *data;
6d44acc9 6783 int length;
51df0ab5 6784 struct ssh_channel *c;
e223b7c7 6785 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 6786 if (!c)
e223b7c7 6787 return;
51df0ab5 6788 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6789 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6790 return; /* extended but not stderr */
6791 ssh_pkt_getstring(pktin, &data, &length);
6792 if (data) {
6793 int bufsize = 0;
6794 c->v.v2.locwindow -= length;
0e443c99 6795 c->v.v2.remlocwin -= length;
51df0ab5 6796 switch (c->type) {
6797 case CHAN_MAINSESSION:
6798 bufsize =
6799 from_backend(ssh->frontend, pktin->type ==
6800 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6801 data, length);
6802 break;
6803 case CHAN_X11:
6804 bufsize = x11_send(c->u.x11.s, data, length);
6805 break;
6806 case CHAN_SOCKDATA:
6807 bufsize = pfd_send(c->u.pfd.s, data, length);
6808 break;
6809 case CHAN_AGENT:
6810 while (length > 0) {
6811 if (c->u.a.lensofar < 4) {
62ddb51e 6812 unsigned int l = min(4 - c->u.a.lensofar,
6813 (unsigned)length);
51df0ab5 6814 memcpy(c->u.a.msglen + c->u.a.lensofar,
6815 data, l);
6816 data += l;
6817 length -= l;
6818 c->u.a.lensofar += l;
6819 }
6820 if (c->u.a.lensofar == 4) {
6821 c->u.a.totallen =
6822 4 + GET_32BIT(c->u.a.msglen);
6823 c->u.a.message = snewn(c->u.a.totallen,
6824 unsigned char);
6825 memcpy(c->u.a.message, c->u.a.msglen, 4);
6826 }
6827 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 6828 unsigned int l =
51df0ab5 6829 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 6830 (unsigned)length);
51df0ab5 6831 memcpy(c->u.a.message + c->u.a.lensofar,
6832 data, l);
6833 data += l;
6834 length -= l;
6835 c->u.a.lensofar += l;
6836 }
6837 if (c->u.a.lensofar == c->u.a.totallen) {
6838 void *reply;
6839 int replylen;
6840 if (agent_query(c->u.a.message,
6841 c->u.a.totallen,
6842 &reply, &replylen,
6843 ssh_agentf_callback, c))
6844 ssh_agentf_callback(c, reply, replylen);
6845 sfree(c->u.a.message);
bc06669b 6846 c->u.a.message = NULL;
51df0ab5 6847 c->u.a.lensofar = 0;
6848 }
6849 }
6850 bufsize = 0;
6851 break;
6852 }
6853 /*
0e443c99 6854 * If it looks like the remote end hit the end of its window,
6855 * and we didn't want it to do that, think about using a
6856 * larger window.
6857 */
6858 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6859 c->v.v2.locmaxwin < 0x40000000)
6860 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6861 /*
51df0ab5 6862 * If we are not buffering too much data,
6863 * enlarge the window again at the remote side.
467e064d 6864 * If we are buffering too much, we may still
6865 * need to adjust the window if the server's
6866 * sent excess data.
51df0ab5 6867 */
9b53e9b8 6868 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6869 c->v.v2.locmaxwin - bufsize : 0);
ff68564b 6870 /*
6871 * If we're either buffering way too much data, or if we're
6872 * buffering anything at all and we're in "simple" mode,
6873 * throttle the whole channel.
6874 */
6875 if ((bufsize > c->v.v2.locmaxwin ||
4a693cfc 6876 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
ff68564b 6877 !c->throttling_conn) {
6878 c->throttling_conn = 1;
6879 ssh_throttle_conn(ssh, +1);
6880 }
51df0ab5 6881 }
6882}
6883
bc06669b 6884static void ssh_channel_destroy(struct ssh_channel *c)
51df0ab5 6885{
bc06669b 6886 Ssh ssh = c->ssh;
51df0ab5 6887
bc06669b 6888 switch (c->type) {
6889 case CHAN_MAINSESSION:
6890 ssh->mainchan = NULL;
6891 update_specials_menu(ssh->frontend);
6892 break;
6893 case CHAN_X11:
6894 if (c->u.x11.s != NULL)
6895 x11_close(c->u.x11.s);
6896 logevent("Forwarded X11 connection terminated");
6897 break;
6898 case CHAN_AGENT:
6899 sfree(c->u.a.message);
6900 break;
6901 case CHAN_SOCKDATA:
6902 if (c->u.pfd.s != NULL)
6903 pfd_close(c->u.pfd.s);
6904 logevent("Forwarded port closed");
6905 break;
6906 }
6907
6908 del234(ssh->channels, c);
3620f307 6909 if (ssh->version == 2) {
bc06669b 6910 bufchain_clear(&c->v.v2.outbuffer);
3620f307 6911 assert(c->v.v2.chanreq_head == NULL);
6912 }
bc06669b 6913 sfree(c);
6914
6915 /*
6916 * See if that was the last channel left open.
6917 * (This is only our termination condition if we're
6918 * not running in -N mode.)
6919 */
6920 if (ssh->version == 2 &&
6921 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
6922 count234(ssh->channels) == 0) {
6923 /*
6924 * We used to send SSH_MSG_DISCONNECT here,
6925 * because I'd believed that _every_ conforming
6926 * SSH-2 connection had to end with a disconnect
6927 * being sent by at least one side; apparently
6928 * I was wrong and it's perfectly OK to
6929 * unceremoniously slam the connection shut
6930 * when you're done, and indeed OpenSSH feels
6931 * this is more polite than sending a
6932 * DISCONNECT. So now we don't.
6933 */
6934 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6935 }
6936}
6937
6938static void ssh2_channel_check_close(struct ssh_channel *c)
6939{
6940 Ssh ssh = c->ssh;
6941 struct Packet *pktout;
6942
04120005 6943 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
6944 c->type == CHAN_ZOMBIE) &&
6945 !c->v.v2.chanreq_head &&
6946 !(c->closes & CLOSES_SENT_CLOSE)) {
bc06669b 6947 /*
04120005 6948 * We have both sent and received EOF (or the channel is a
6949 * zombie), and we have no outstanding channel requests, which
6950 * means the channel is in final wind-up. But we haven't sent
6951 * CLOSE, so let's do so now.
bc06669b 6952 */
6953 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6954 ssh2_pkt_adduint32(pktout, c->remoteid);
6955 ssh2_pkt_send(ssh, pktout);
04120005 6956 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
bc06669b 6957 }
6958
6959 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
3620f307 6960 assert(c->v.v2.chanreq_head == NULL);
bc06669b 6961 /*
6962 * We have both sent and received CLOSE, which means we're
6963 * completely done with the channel.
6964 */
6965 ssh_channel_destroy(c);
6966 }
6967}
6968
6969static void ssh2_channel_got_eof(struct ssh_channel *c)
6970{
6971 if (c->closes & CLOSES_RCVD_EOF)
6972 return; /* already seen EOF */
6973 c->closes |= CLOSES_RCVD_EOF;
51df0ab5 6974
6975 if (c->type == CHAN_X11) {
bc06669b 6976 x11_send_eof(c->u.x11.s);
51df0ab5 6977 } else if (c->type == CHAN_AGENT) {
bc06669b 6978 /* Manufacture an outgoing EOF in response to the incoming one. */
6979 sshfwd_write_eof(c);
51df0ab5 6980 } else if (c->type == CHAN_SOCKDATA) {
bc06669b 6981 pfd_send_eof(c->u.pfd.s);
6982 } else if (c->type == CHAN_MAINSESSION) {
6983 Ssh ssh = c->ssh;
6984
4a202fc6 6985 if (!ssh->sent_console_eof &&
6986 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
bc06669b 6987 /*
4a202fc6 6988 * Either from_backend_eof told us that the front end
6989 * wants us to close the outgoing side of the connection
6990 * as soon as we see EOF from the far end, or else we've
6991 * unilaterally decided to do that because we've allocated
6992 * a remote pty and hence EOF isn't a particularly
6993 * meaningful concept.
bc06669b 6994 */
6995 sshfwd_write_eof(c);
6996 }
6997 ssh->sent_console_eof = TRUE;
51df0ab5 6998 }
bc06669b 6999
7000 ssh2_channel_check_close(c);
7001}
7002
7003static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7004{
7005 struct ssh_channel *c;
7006
7007 c = ssh2_channel_msg(ssh, pktin);
7008 if (!c)
7009 return;
7010 ssh2_channel_got_eof(c);
51df0ab5 7011}
7012
7013static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7014{
51df0ab5 7015 struct ssh_channel *c;
51df0ab5 7016
e223b7c7 7017 c = ssh2_channel_msg(ssh, pktin);
7018 if (!c)
51df0ab5 7019 return;
51df0ab5 7020
7021 /*
bc06669b 7022 * When we receive CLOSE on a channel, we assume it comes with an
7023 * implied EOF if we haven't seen EOF yet.
51df0ab5 7024 */
bc06669b 7025 ssh2_channel_got_eof(c);
7026
7027 /*
3effbcf2 7028 * And we also send an outgoing EOF, if we haven't already, on the
7029 * assumption that CLOSE is a pretty forceful announcement that
7030 * the remote side is doing away with the entire channel. (If it
7031 * had wanted to send us EOF and continue receiving data from us,
7032 * it would have just sent CHANNEL_EOF.)
3effbcf2 7033 */
a699eb41 7034 if (!(c->closes & CLOSES_SENT_EOF)) {
7035 /*
7036 * Make sure we don't read any more from whatever our local
7037 * data source is for this channel.
7038 */
7039 switch (c->type) {
7040 case CHAN_MAINSESSION:
7041 ssh->send_ok = 0; /* stop trying to read from stdin */
7042 break;
7043 case CHAN_X11:
7044 x11_override_throttle(c->u.x11.s, 1);
7045 break;
7046 case CHAN_SOCKDATA:
7047 pfd_override_throttle(c->u.pfd.s, 1);
7048 break;
7049 }
7050
7051 /*
7052 * Send outgoing EOF.
7053 */
7539afa2 7054 sshfwd_write_eof(c);
3effbcf2 7055 }
7056
7057 /*
bc06669b 7058 * Now process the actual close.
7059 */
7060 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7061 c->closes |= CLOSES_RCVD_CLOSE;
7062 ssh2_channel_check_close(c);
51df0ab5 7063 }
7064}
7065
7066static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7067{
51df0ab5 7068 struct ssh_channel *c;
51df0ab5 7069
e223b7c7 7070 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7071 if (!c)
e223b7c7 7072 return;
51df0ab5 7073 if (c->type != CHAN_SOCKDATA_DORMANT)
7074 return; /* dunno why they're confirming this */
7075 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 7076 c->halfopen = FALSE;
51df0ab5 7077 c->type = CHAN_SOCKDATA;
7078 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7079 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7080 if (c->u.pfd.s)
7081 pfd_confirm(c->u.pfd.s);
bc06669b 7082 if (c->pending_eof)
7083 ssh_channel_try_eof(c);
51df0ab5 7084}
7085
7086static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7087{
7088 static const char *const reasons[] = {
7089 "<unknown reason code>",
7090 "Administratively prohibited",
7091 "Connect failed",
7092 "Unknown channel type",
7093 "Resource shortage",
7094 };
51df0ab5 7095 unsigned reason_code;
7096 char *reason_string;
7097 int reason_length;
51df0ab5 7098 struct ssh_channel *c;
e223b7c7 7099 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7100 if (!c)
e223b7c7 7101 return;
51df0ab5 7102 if (c->type != CHAN_SOCKDATA_DORMANT)
7103 return; /* dunno why they're failing this */
7104
7105 reason_code = ssh_pkt_getuint32(pktin);
7106 if (reason_code >= lenof(reasons))
7107 reason_code = 0; /* ensure reasons[reason_code] in range */
7108 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 7109 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7110 reasons[reason_code], reason_length, reason_string);
51df0ab5 7111
7112 pfd_close(c->u.pfd.s);
7113
7114 del234(ssh->channels, c);
7115 sfree(c);
7116}
7117
7118static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7119{
51df0ab5 7120 char *type;
7121 int typelen, want_reply;
7122 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7123 struct ssh_channel *c;
7124 struct Packet *pktout;
7125
e223b7c7 7126 c = ssh2_channel_msg(ssh, pktin);
7127 if (!c)
7128 return;
51df0ab5 7129 ssh_pkt_getstring(pktin, &type, &typelen);
7130 want_reply = ssh2_pkt_getbool(pktin);
7131
7132 /*
51df0ab5 7133 * Having got the channel number, we now look at
7134 * the request type string to see if it's something
7135 * we recognise.
7136 */
7137 if (c == ssh->mainchan) {
7138 /*
7139 * We recognise "exit-status" and "exit-signal" on
7140 * the primary channel.
7141 */
7142 if (typelen == 11 &&
7143 !memcmp(type, "exit-status", 11)) {
7144
7145 ssh->exitcode = ssh_pkt_getuint32(pktin);
7146 logeventf(ssh, "Server sent command exit status %d",
7147 ssh->exitcode);
7148 reply = SSH2_MSG_CHANNEL_SUCCESS;
7149
7150 } else if (typelen == 11 &&
7151 !memcmp(type, "exit-signal", 11)) {
7152
7153 int is_plausible = TRUE, is_int = FALSE;
7154 char *fmt_sig = "", *fmt_msg = "";
7155 char *msg;
7156 int msglen = 0, core = FALSE;
7157 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7158 * provide an `int' for the signal, despite its
bccbeb71 7159 * having been a `string' in the drafts of RFC 4254 since at
51df0ab5 7160 * least 2001. (Fixed in session.c 1.147.) Try to
7161 * infer which we can safely parse it as. */
7162 {
7163 unsigned char *p = pktin->body +
7164 pktin->savedpos;
7165 long len = pktin->length - pktin->savedpos;
7166 unsigned long num = GET_32BIT(p); /* what is it? */
7167 /* If it's 0, it hardly matters; assume string */
7168 if (num == 0) {
7169 is_int = FALSE;
7170 } else {
7171 int maybe_int = FALSE, maybe_str = FALSE;
7172#define CHECK_HYPOTHESIS(offset, result) \
7173 do { \
7174 long q = offset; \
7175 if (q >= 0 && q+4 <= len) { \
7176 q = q + 4 + GET_32BIT(p+q); \
7177 if (q >= 0 && q+4 <= len && \
c849ff23 7178 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
51df0ab5 7179 result = TRUE; \
7180 } \
7181 } while(0)
7182 CHECK_HYPOTHESIS(4+1, maybe_int);
7183 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7184#undef CHECK_HYPOTHESIS
7185 if (maybe_int && !maybe_str)
7186 is_int = TRUE;
7187 else if (!maybe_int && maybe_str)
7188 is_int = FALSE;
7189 else
7190 /* Crikey. Either or neither. Panic. */
7191 is_plausible = FALSE;
7192 }
7193 }
d051d1b4 7194 ssh->exitcode = 128; /* means `unknown signal' */
51df0ab5 7195 if (is_plausible) {
7196 if (is_int) {
7197 /* Old non-standard OpenSSH. */
7198 int signum = ssh_pkt_getuint32(pktin);
7199 fmt_sig = dupprintf(" %d", signum);
d051d1b4 7200 ssh->exitcode = 128 + signum;
51df0ab5 7201 } else {
bccbeb71 7202 /* As per RFC 4254. */
51df0ab5 7203 char *sig;
7204 int siglen;
7205 ssh_pkt_getstring(pktin, &sig, &siglen);
7206 /* Signal name isn't supposed to be blank, but
7207 * let's cope gracefully if it is. */
7208 if (siglen) {
7209 fmt_sig = dupprintf(" \"%.*s\"",
7210 siglen, sig);
7211 }
d051d1b4 7212
7213 /*
7214 * Really hideous method of translating the
7215 * signal description back into a locally
7216 * meaningful number.
7217 */
7218
7219 if (0)
7220 ;
b707973a 7221#define TRANSLATE_SIGNAL(s) \
7222 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7223 ssh->exitcode = 128 + SIG ## s
d051d1b4 7224#ifdef SIGABRT
b707973a 7225 TRANSLATE_SIGNAL(ABRT);
d051d1b4 7226#endif
7227#ifdef SIGALRM
b707973a 7228 TRANSLATE_SIGNAL(ALRM);
d051d1b4 7229#endif
7230#ifdef SIGFPE
b707973a 7231 TRANSLATE_SIGNAL(FPE);
d051d1b4 7232#endif
7233#ifdef SIGHUP
b707973a 7234 TRANSLATE_SIGNAL(HUP);
d051d1b4 7235#endif
7236#ifdef SIGILL
b707973a 7237 TRANSLATE_SIGNAL(ILL);
d051d1b4 7238#endif
7239#ifdef SIGINT
b707973a 7240 TRANSLATE_SIGNAL(INT);
d051d1b4 7241#endif
7242#ifdef SIGKILL
b707973a 7243 TRANSLATE_SIGNAL(KILL);
d051d1b4 7244#endif
7245#ifdef SIGPIPE
b707973a 7246 TRANSLATE_SIGNAL(PIPE);
d051d1b4 7247#endif
7248#ifdef SIGQUIT
b707973a 7249 TRANSLATE_SIGNAL(QUIT);
d051d1b4 7250#endif
7251#ifdef SIGSEGV
b707973a 7252 TRANSLATE_SIGNAL(SEGV);
d051d1b4 7253#endif
7254#ifdef SIGTERM
b707973a 7255 TRANSLATE_SIGNAL(TERM);
d051d1b4 7256#endif
7257#ifdef SIGUSR1
b707973a 7258 TRANSLATE_SIGNAL(USR1);
d051d1b4 7259#endif
7260#ifdef SIGUSR2
b707973a 7261 TRANSLATE_SIGNAL(USR2);
d051d1b4 7262#endif
b707973a 7263#undef TRANSLATE_SIGNAL
d051d1b4 7264 else
7265 ssh->exitcode = 128;
51df0ab5 7266 }
7267 core = ssh2_pkt_getbool(pktin);
7268 ssh_pkt_getstring(pktin, &msg, &msglen);
7269 if (msglen) {
7270 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7271 }
7272 /* ignore lang tag */
7273 } /* else don't attempt to parse */
7274 logeventf(ssh, "Server exited on signal%s%s%s",
7275 fmt_sig, core ? " (core dumped)" : "",
7276 fmt_msg);
7277 if (*fmt_sig) sfree(fmt_sig);
7278 if (*fmt_msg) sfree(fmt_msg);
7279 reply = SSH2_MSG_CHANNEL_SUCCESS;
7280
7281 }
7282 } else {
7283 /*
7284 * This is a channel request we don't know
7285 * about, so we now either ignore the request
7286 * or respond with CHANNEL_FAILURE, depending
7287 * on want_reply.
7288 */
7289 reply = SSH2_MSG_CHANNEL_FAILURE;
7290 }
7291 if (want_reply) {
7292 pktout = ssh2_pkt_init(reply);
7293 ssh2_pkt_adduint32(pktout, c->remoteid);
7294 ssh2_pkt_send(ssh, pktout);
7295 }
7296}
7297
7298static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7299{
7300 char *type;
7301 int typelen, want_reply;
7302 struct Packet *pktout;
7303
7304 ssh_pkt_getstring(pktin, &type, &typelen);
7305 want_reply = ssh2_pkt_getbool(pktin);
7306
7307 /*
7308 * We currently don't support any global requests
7309 * at all, so we either ignore the request or
7310 * respond with REQUEST_FAILURE, depending on
7311 * want_reply.
7312 */
7313 if (want_reply) {
7314 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7315 ssh2_pkt_send(ssh, pktout);
7316 }
7317}
7318
7319static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7320{
7321 char *type;
7322 int typelen;
7323 char *peeraddr;
7324 int peeraddrlen;
7325 int peerport;
7326 char *error = NULL;
7327 struct ssh_channel *c;
7328 unsigned remid, winsize, pktsize;
7329 struct Packet *pktout;
7330
7331 ssh_pkt_getstring(pktin, &type, &typelen);
7332 c = snew(struct ssh_channel);
7333 c->ssh = ssh;
7334
7335 remid = ssh_pkt_getuint32(pktin);
7336 winsize = ssh_pkt_getuint32(pktin);
7337 pktsize = ssh_pkt_getuint32(pktin);
7338
7339 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7340 char *addrstr;
5907ebda 7341 const char *x11err;
51df0ab5 7342
7343 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7344 addrstr = snewn(peeraddrlen+1, char);
7345 memcpy(addrstr, peeraddr, peeraddrlen);
7346 addrstr[peeraddrlen] = '\0';
7347 peerport = ssh_pkt_getuint32(pktin);
7348
7349 logeventf(ssh, "Received X11 connect request from %s:%d",
7350 addrstr, peerport);
7351
7352 if (!ssh->X11_fwd_enabled)
7353 error = "X11 forwarding is not enabled";
5907ebda 7354 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
4a693cfc 7355 addrstr, peerport, ssh->conf)) != NULL) {
5907ebda 7356 logeventf(ssh, "Local X11 connection failed: %s", x11err);
51df0ab5 7357 error = "Unable to open an X11 connection";
7358 } else {
7359 logevent("Opening X11 forward connection succeeded");
7360 c->type = CHAN_X11;
7361 }
7362
7363 sfree(addrstr);
7364 } else if (typelen == 15 &&
7365 !memcmp(type, "forwarded-tcpip", 15)) {
7366 struct ssh_rportfwd pf, *realpf;
7367 char *dummy;
7368 int dummylen;
7369 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7370 pf.sport = ssh_pkt_getuint32(pktin);
7371 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7372 peerport = ssh_pkt_getuint32(pktin);
7373 realpf = find234(ssh->rportfwds, &pf, NULL);
7374 logeventf(ssh, "Received remote port %d open request "
7375 "from %s:%d", pf.sport, peeraddr, peerport);
7376 if (realpf == NULL) {
7377 error = "Remote port is not recognised";
7378 } else {
7379 const char *e = pfd_newconnect(&c->u.pfd.s,
7380 realpf->dhost,
7381 realpf->dport, c,
4a693cfc 7382 ssh->conf,
05581745 7383 realpf->pfrec->addressfamily);
51df0ab5 7384 logeventf(ssh, "Attempting to forward remote port to "
7385 "%s:%d", realpf->dhost, realpf->dport);
7386 if (e != NULL) {
7387 logeventf(ssh, "Port open failed: %s", e);
7388 error = "Port open failed";
7389 } else {
7390 logevent("Forwarded port opened successfully");
7391 c->type = CHAN_SOCKDATA;
7392 }
7393 }
7394 } else if (typelen == 22 &&
c49cf994 7395 !memcmp(type, "auth-agent@openssh.com", 22)) {
51df0ab5 7396 if (!ssh->agentfwd_enabled)
7397 error = "Agent forwarding is not enabled";
7398 else {
7399 c->type = CHAN_AGENT; /* identify channel type */
7400 c->u.a.lensofar = 0;
7401 }
7402 } else {
7403 error = "Unsupported channel type requested";
7404 }
7405
7406 c->remoteid = remid;
64d6ff88 7407 c->halfopen = FALSE;
51df0ab5 7408 if (error) {
7409 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7410 ssh2_pkt_adduint32(pktout, c->remoteid);
7411 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7412 ssh2_pkt_addstring(pktout, error);
7413 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7414 ssh2_pkt_send(ssh, pktout);
7415 logeventf(ssh, "Rejected channel open: %s", error);
7416 sfree(c);
7417 } else {
94bdfe40 7418 ssh2_channel_init(c);
51df0ab5 7419 c->v.v2.remwindow = winsize;
7420 c->v.v2.remmaxpkt = pktsize;
51df0ab5 7421 add234(ssh->channels, c);
7422 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7423 ssh2_pkt_adduint32(pktout, c->remoteid);
7424 ssh2_pkt_adduint32(pktout, c->localid);
7425 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 7426 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 7427 ssh2_pkt_send(ssh, pktout);
7428 }
7429}
7430
6bbce591 7431/*
adb6167a 7432 * Buffer banner messages for later display at some convenient point,
7433 * if we're going to display them.
6bbce591 7434 */
7435static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7436{
7437 /* Arbitrary limit to prevent unbounded inflation of buffer */
4a693cfc 7438 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
adb6167a 7439 bufchain_size(&ssh->banner) <= 131072) {
6bbce591 7440 char *banner = NULL;
7441 int size = 0;
7442 ssh_pkt_getstring(pktin, &banner, &size);
7443 if (banner)
7444 bufchain_add(&ssh->banner, banner, size);
7445 }
7446}
7447
c6ccd5c2 7448/* Helper function to deal with sending tty modes for "pty-req" */
7449static void ssh2_send_ttymode(void *data, char *mode, char *val)
7450{
7451 struct Packet *pktout = (struct Packet *)data;
7452 int i = 0;
7453 unsigned int arg = 0;
7454 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7455 if (i == lenof(ssh_ttymodes)) return;
7456 switch (ssh_ttymodes[i].type) {
7457 case TTY_OP_CHAR:
7458 arg = ssh_tty_parse_specchar(val);
7459 break;
7460 case TTY_OP_BOOL:
7461 arg = ssh_tty_parse_boolean(val);
7462 break;
7463 }
7464 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7465 ssh2_pkt_adduint32(pktout, arg);
7466}
7467
ebbc254d 7468static void ssh2_maybe_setup_x11(struct ssh_channel *c, struct Packet *pktin,
7469 void *ctx)
7470{
7471 struct ssh2_maybe_setup_x11_state {
7472 int crLine;
7473 };
7474 Ssh ssh = c->ssh;
7475 struct Packet *pktout;
7476 crStateP(ssh2_maybe_setup_x11_state, ctx);
7477
7478 crBeginState;
7479
7480 /*
7481 * Potentially enable X11 forwarding.
7482 */
7483 if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_x11_forward) &&
7484 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
7485 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
7486 logevent("Requesting X11 forwarding");
134f5ece 7487 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
7488 ssh2_maybe_setup_x11, s);
ebbc254d 7489 ssh2_pkt_addbool(pktout, 0); /* many connections */
7490 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname);
7491 /*
7492 * Note that while we blank the X authentication data here, we don't
7493 * take any special action to blank the start of an X11 channel,
7494 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7495 * without having session blanking enabled is likely to leak your
7496 * cookie into the log.
7497 */
7498 dont_log_password(ssh, pktout, PKTLOG_BLANK);
7499 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring);
7500 end_log_omission(ssh, pktout);
7501 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
7502 ssh2_pkt_send(ssh, pktout);
7503
ebbc254d 7504 crWaitUntilV(pktin);
7505
3620f307 7506 if (pktin) {
7507 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7508 logevent("X11 forwarding enabled");
7509 ssh->X11_fwd_enabled = TRUE;
7510 } else
7511 logevent("X11 forwarding refused");
7512 }
ebbc254d 7513 }
5ca12719 7514 crFinishFreeV(s);
ebbc254d 7515}
7516
7517static void ssh2_maybe_setup_agent(struct ssh_channel *c, struct Packet *pktin,
7518 void *ctx)
7519{
7520 struct ssh2_maybe_setup_agent_state {
7521 int crLine;
7522 };
7523 Ssh ssh = c->ssh;
7524 struct Packet *pktout;
7525 crStateP(ssh2_maybe_setup_agent_state, ctx);
7526
7527 crBeginState;
7528
7529 if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
7530 logevent("Requesting OpenSSH-style agent forwarding");
134f5ece 7531 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
7532 ssh2_maybe_setup_agent, s);
ebbc254d 7533 ssh2_pkt_send(ssh, pktout);
7534
ebbc254d 7535 crWaitUntilV(pktin);
7536
3620f307 7537 if (pktin) {
7538 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7539 logevent("Agent forwarding enabled");
7540 ssh->agentfwd_enabled = TRUE;
7541 } else
7542 logevent("Agent forwarding refused");
7543 }
ebbc254d 7544 }
5ca12719 7545 crFinishFreeV(s);
ebbc254d 7546}
7547
7548static void ssh2_maybe_setup_pty(struct ssh_channel *c, struct Packet *pktin,
7549 void *ctx)
7550{
7551 struct ssh2_maybe_setup_pty_state {
7552 int crLine;
7553 };
7554 Ssh ssh = c->ssh;
7555 struct Packet *pktout;
7556 crStateP(ssh2_maybe_setup_pty_state, ctx);
7557
7558 crBeginState;
7559
7560 if (ssh->mainchan && !ssh->ncmode && !conf_get_int(ssh->conf, CONF_nopty)) {
7561 /* Unpick the terminal-speed string. */
7562 /* XXX perhaps we should allow no speeds to be sent. */
7563 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7564 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
7565 /* Build the pty request. */
134f5ece 7566 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
7567 ssh2_maybe_setup_pty, s);
ebbc254d 7568 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
7569 ssh2_pkt_adduint32(pktout, ssh->term_width);
7570 ssh2_pkt_adduint32(pktout, ssh->term_height);
7571 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
7572 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
7573 ssh2_pkt_addstring_start(pktout);
7574 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
7575 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
7576 ssh2_pkt_adduint32(pktout, ssh->ispeed);
7577 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
7578 ssh2_pkt_adduint32(pktout, ssh->ospeed);
7579 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
7580 ssh2_pkt_send(ssh, pktout);
7581 ssh->state = SSH_STATE_INTERMED;
7582
ebbc254d 7583 crWaitUntilV(pktin);
7584
3620f307 7585 if (pktin) {
7586 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7587 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7588 ssh->ospeed, ssh->ispeed);
7589 ssh->got_pty = TRUE;
7590 } else {
7591 c_write_str(ssh, "Server refused to allocate pty\r\n");
7592 ssh->editing = ssh->echoing = 1;
7593 }
ebbc254d 7594 }
7595 } else {
7596 ssh->editing = ssh->echoing = 1;
7597 }
5ca12719 7598 crFinishFreeV(s);
ebbc254d 7599}
7600
7601static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
7602 void *ctx)
7603{
7604 struct ssh2_setup_env_state {
7605 int crLine;
7606 int num_env, env_left, env_ok;
7607 };
7608 Ssh ssh = c->ssh;
7609 struct Packet *pktout;
7610 crStateP(ssh2_setup_env_state, ctx);
7611
7612 crBeginState;
7613
7614 /*
7615 * Send environment variables.
7616 *
7617 * Simplest thing here is to send all the requests at once, and
7618 * then wait for a whole bunch of successes or failures.
7619 */
7620 s->num_env = 0;
7621 if (ssh->mainchan && !ssh->ncmode) {
7622 char *key, *val;
7623
7624 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
7625 val != NULL;
7626 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
134f5ece 7627 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
ebbc254d 7628 ssh2_pkt_addstring(pktout, key);
7629 ssh2_pkt_addstring(pktout, val);
7630 ssh2_pkt_send(ssh, pktout);
ebbc254d 7631
7632 s->num_env++;
7633 }
7634 if (s->num_env)
7635 logeventf(ssh, "Sent %d environment variables", s->num_env);
7636 }
7637
7638 if (s->num_env) {
7639 s->env_ok = 0;
7640 s->env_left = s->num_env;
7641
7642 while (s->env_left > 0) {
7643 crWaitUntilV(pktin);
3620f307 7644 if (!pktin) goto out;
c330b1cc 7645 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
ebbc254d 7646 s->env_ok++;
ebbc254d 7647 s->env_left--;
7648 }
7649
7650 if (s->env_ok == s->num_env) {
7651 logevent("All environment variables successfully set");
7652 } else if (s->env_ok == 0) {
7653 logevent("All environment variables refused");
7654 c_write_str(ssh, "Server refused to set environment variables\r\n");
7655 } else {
7656 logeventf(ssh, "%d environment variables refused",
7657 s->num_env - s->env_ok);
7658 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7659 }
7660 }
5ca12719 7661 out:;
7662 crFinishFreeV(s);
ebbc254d 7663}
7664
783415f8 7665/*
2e85c969 7666 * Handle the SSH-2 userauth and connection layers.
7cca0d81 7667 */
bc074147 7668static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
7669{
7670 do_ssh2_authconn(ssh, NULL, 0, pktin);
7671}
7672
ebbc254d 7673static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
7674 void *ctx)
7675{
7676 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
7677}
7678
ff3187f6 7679static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7680 struct Packet *pktin)
7cca0d81 7681{
51470298 7682 struct do_ssh2_authconn_state {
30919997 7683 int crLine;
51470298 7684 enum {
51470298 7685 AUTH_TYPE_NONE,
7686 AUTH_TYPE_PUBLICKEY,
7687 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7688 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7689 AUTH_TYPE_PASSWORD,
8221906d 7690 AUTH_TYPE_GSSAPI, /* always QUIET */
51470298 7691 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7692 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7693 } type;
a1a1fae4 7694 int done_service_req;
51470298 7695 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
94cd7c3a 7696 int tried_pubkey_config, done_agent;
bf84a03a 7697#ifndef NO_GSSAPI
42af6a67 7698 int can_gssapi;
7699 int tried_gssapi;
bf84a03a 7700#endif
edd0cb8a 7701 int kbd_inter_refused;
ab18ccff 7702 int we_are_in, userauth_success;
edd0cb8a 7703 prompts_t *cur_prompt;
7704 int num_prompts;
4a693cfc 7705 char *username;
e955d348 7706 char *password;
51470298 7707 int got_username;
51470298 7708 void *publickey_blob;
7709 int publickey_bloblen;
edd0cb8a 7710 int publickey_encrypted;
7711 char *publickey_algorithm;
7712 char *publickey_comment;
94cd7c3a 7713 unsigned char agent_request[5], *agent_response, *agentp;
7714 int agent_responselen;
7715 unsigned char *pkblob_in_agent;
51470298 7716 int keyi, nkeys;
51470298 7717 char *pkblob, *alg, *commentp;
7718 int pklen, alglen, commentlen;
7719 int siglen, retlen, len;
7720 char *q, *agentreq, *ret;
7721 int try_send;
ff3187f6 7722 struct Packet *pktout;
4a693cfc 7723 Filename *keyfile;
bf84a03a 7724#ifndef NO_GSSAPI
b3d375b2 7725 struct ssh_gss_library *gsslib;
42af6a67 7726 Ssh_gss_ctx gss_ctx;
7727 Ssh_gss_buf gss_buf;
7728 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7729 Ssh_gss_name gss_srv_name;
7730 Ssh_gss_stat gss_stat;
bf84a03a 7731#endif
51470298 7732 };
7733 crState(do_ssh2_authconn_state);
7734
30919997 7735 crBeginState;
e5574168 7736
bc074147 7737 /* Register as a handler for all the messages this coroutine handles. */
7738 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
7739 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
7740 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
7741 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
7742 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
7743 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
7744 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7745 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7746 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
7747 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
7748 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
7749 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
7750 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
7751 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
7752 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
7753 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
7754 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
7755 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
7756 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
7757 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
bc074147 7758
a1a1fae4 7759 s->done_service_req = FALSE;
ab18ccff 7760 s->we_are_in = s->userauth_success = FALSE;
bf84a03a 7761#ifndef NO_GSSAPI
42af6a67 7762 s->tried_gssapi = FALSE;
bf84a03a 7763#endif
42af6a67 7764
4a693cfc 7765 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
a1a1fae4 7766 /*
7767 * Request userauth protocol, and await a response to it.
7768 */
7769 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7770 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7771 ssh2_pkt_send(ssh, s->pktout);
7772 crWaitUntilV(pktin);
7773 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7774 s->done_service_req = TRUE;
7775 }
7776 if (!s->done_service_req) {
7777 /*
7778 * Request connection protocol directly, without authentication.
7779 */
7780 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7781 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7782 ssh2_pkt_send(ssh, s->pktout);
7783 crWaitUntilV(pktin);
7784 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7785 s->we_are_in = TRUE; /* no auth required */
7786 } else {
7787 bombout(("Server refused service request"));
7788 crStopV;
7789 }
8d5de777 7790 }
7cca0d81 7791
94cd7c3a 7792 /* Arrange to be able to deal with any BANNERs that come in.
7793 * (We do this now as packets may come in during the next bit.) */
7794 bufchain_init(&ssh->banner);
7795 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7796 ssh2_msg_userauth_banner;
7797
7cca0d81 7798 /*
edd0cb8a 7799 * Misc one-time setup for authentication.
7800 */
7801 s->publickey_blob = NULL;
7802 if (!s->we_are_in) {
7803
7804 /*
7805 * Load the public half of any configured public key file
7806 * for later use.
7807 */
4a693cfc 7808 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 7809 if (!filename_is_null(s->keyfile)) {
edd0cb8a 7810 int keytype;
7811 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 7812 filename_to_str(s->keyfile));
7813 keytype = key_type(s->keyfile);
edd0cb8a 7814 if (keytype == SSH_KEYTYPE_SSH2) {
7815 const char *error;
7816 s->publickey_blob =
4a693cfc 7817 ssh2_userkey_loadpub(s->keyfile,
edd0cb8a 7818 &s->publickey_algorithm,
7819 &s->publickey_bloblen,
7820 &s->publickey_comment, &error);
7821 if (s->publickey_blob) {
7822 s->publickey_encrypted =
4a693cfc 7823 ssh2_userkey_encrypted(s->keyfile, NULL);
edd0cb8a 7824 } else {
7825 char *msgbuf;
7826 logeventf(ssh, "Unable to load private key (%s)",
7827 error);
7828 msgbuf = dupprintf("Unable to load private key file "
7829 "\"%.150s\" (%s)\r\n",
4a693cfc 7830 filename_to_str(s->keyfile),
edd0cb8a 7831 error);
7832 c_write_str(ssh, msgbuf);
7833 sfree(msgbuf);
7834 }
7835 } else {
7836 char *msgbuf;
7837 logeventf(ssh, "Unable to use this key file (%s)",
7838 key_type_to_str(keytype));
7839 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7840 " (%s)\r\n",
4a693cfc 7841 filename_to_str(s->keyfile),
edd0cb8a 7842 key_type_to_str(keytype));
7843 c_write_str(ssh, msgbuf);
7844 sfree(msgbuf);
7845 s->publickey_blob = NULL;
7846 }
7847 }
7848
94cd7c3a 7849 /*
7850 * Find out about any keys Pageant has (but if there's a
7851 * public key configured, filter out all others).
7852 */
7853 s->nkeys = 0;
7854 s->agent_response = NULL;
7855 s->pkblob_in_agent = NULL;
4a693cfc 7856 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
94cd7c3a 7857
7858 void *r;
7859
7860 logevent("Pageant is running. Requesting keys.");
7861
7862 /* Request the keys held by the agent. */
7863 PUT_32BIT(s->agent_request, 1);
7864 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7865 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7866 ssh_agent_callback, ssh)) {
7867 do {
7868 crReturnV;
7869 if (pktin) {
7870 bombout(("Unexpected data from server while"
7871 " waiting for agent response"));
7872 crStopV;
7873 }
7874 } while (pktin || inlen > 0);
7875 r = ssh->agent_response;
7876 s->agent_responselen = ssh->agent_response_len;
7877 }
7878 s->agent_response = (unsigned char *) r;
7879 if (s->agent_response && s->agent_responselen >= 5 &&
7880 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7881 int keyi;
7882 unsigned char *p;
7883 p = s->agent_response + 5;
7884 s->nkeys = GET_32BIT(p);
7885 p += 4;
7886 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
7887 if (s->publickey_blob) {
7888 /* See if configured key is in agent. */
7889 for (keyi = 0; keyi < s->nkeys; keyi++) {
7890 s->pklen = GET_32BIT(p);
7891 if (s->pklen == s->publickey_bloblen &&
7892 !memcmp(p+4, s->publickey_blob,
7893 s->publickey_bloblen)) {
7894 logeventf(ssh, "Pageant key #%d matches "
7895 "configured key file", keyi);
7896 s->keyi = keyi;
7897 s->pkblob_in_agent = p;
7898 break;
7899 }
7900 p += 4 + s->pklen;
7901 p += GET_32BIT(p) + 4; /* comment */
7902 }
7903 if (!s->pkblob_in_agent) {
7904 logevent("Configured key file not in Pageant");
7905 s->nkeys = 0;
7906 }
7907 }
5ff99b8e 7908 } else {
7909 logevent("Failed to get reply from Pageant");
94cd7c3a 7910 }
7911 }
7912
edd0cb8a 7913 }
7914
7915 /*
1408a877 7916 * We repeat this whole loop, including the username prompt,
7917 * until we manage a successful authentication. If the user
51470298 7918 * types the wrong _password_, they can be sent back to the
7919 * beginning to try another username, if this is configured on.
7920 * (If they specify a username in the config, they are never
7921 * asked, even if they do give a wrong password.)
1408a877 7922 *
7923 * I think this best serves the needs of
7924 *
7925 * - the people who have no configuration, no keys, and just
7926 * want to try repeated (username,password) pairs until they
7927 * type both correctly
7928 *
7929 * - people who have keys and configuration but occasionally
7930 * need to fall back to passwords
7931 *
7932 * - people with a key held in Pageant, who might not have
7933 * logged in to a particular machine before; so they want to
7934 * type a username, and then _either_ their key will be
7935 * accepted, _or_ they will type a password. If they mistype
7936 * the username they will want to be able to get back and
7937 * retype it!
7cca0d81 7938 */
51470298 7939 s->got_username = FALSE;
a1a1fae4 7940 while (!s->we_are_in) {
1408a877 7941 /*
7942 * Get a username.
7943 */
4a693cfc 7944 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
5bb641e1 7945 /*
7946 * We got a username last time round this loop, and
7947 * with change_username turned off we don't try to get
7948 * it again.
7949 */
4a693cfc 7950 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 7951 int ret; /* need not be kept over crReturn */
7952 s->cur_prompt = new_prompts(ssh->frontend);
7953 s->cur_prompt->to_server = TRUE;
7954 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 7955 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 7956 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7957 while (ret < 0) {
51470298 7958 ssh->send_ok = 1;
edd0cb8a 7959 crWaitUntilV(!pktin);
7960 ret = get_userpass_input(s->cur_prompt, in, inlen);
7961 ssh->send_ok = 0;
32874aea 7962 }
edd0cb8a 7963 if (!ret) {
7964 /*
7965 * get_userpass_input() failed to get a username.
7966 * Terminate.
7967 */
7968 free_prompts(s->cur_prompt);
7969 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7970 crStopV;
7971 }
4a693cfc 7972 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 7973 free_prompts(s->cur_prompt);
7cca0d81 7974 } else {
57356d63 7975 char *stuff;
65a22376 7976 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4a693cfc 7977 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
51470298 7978 c_write_str(ssh, stuff);
57356d63 7979 sfree(stuff);
7cca0d81 7980 }
7981 }
51470298 7982 s->got_username = TRUE;
7cca0d81 7983
65a22376 7984 /*
1408a877 7985 * Send an authentication request using method "none": (a)
7986 * just in case it succeeds, and (b) so that we know what
7987 * authentication methods we can usefully try next.
65a22376 7988 */
acab36bc 7989 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
51470298 7990
ff3187f6 7991 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7992 ssh2_pkt_addstring(s->pktout, ssh->username);
ff3187f6 7993 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7994 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7995 ssh2_pkt_send(ssh, s->pktout);
51470298 7996 s->type = AUTH_TYPE_NONE;
7997 s->gotit = FALSE;
7998 s->we_are_in = FALSE;
7999
8000 s->tried_pubkey_config = FALSE;
6ac3a551 8001 s->kbd_inter_refused = FALSE;
65a22376 8002
94cd7c3a 8003 /* Reset agent request state. */
8004 s->done_agent = FALSE;
8005 if (s->agent_response) {
8006 if (s->pkblob_in_agent) {
8007 s->agentp = s->pkblob_in_agent;
8008 } else {
8009 s->agentp = s->agent_response + 5 + 4;
8010 s->keyi = 0;
8011 }
8012 }
8013
1408a877 8014 while (1) {
854caca5 8015 char *methods = NULL;
8016 int methlen = 0;
8017
1408a877 8018 /*
8019 * Wait for the result of the last authentication request.
8020 */
51470298 8021 if (!s->gotit)
ff3187f6 8022 crWaitUntilV(pktin);
6bbce591 8023 /*
8024 * Now is a convenient point to spew any banner material
8025 * that we've accumulated. (This should ensure that when
8026 * we exit the auth loop, we haven't any left to deal
8027 * with.)
8028 */
8029 {
8030 int size = bufchain_size(&ssh->banner);
32874aea 8031 /*
8032 * Don't show the banner if we're operating in
8033 * non-verbose non-interactive mode. (It's probably
8034 * a script, which means nobody will read the
8035 * banner _anyway_, and moreover the printing of
8036 * the banner will screw up processing on the
8037 * output of (say) plink.)
8038 */
6bbce591 8039 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8040 char *banner = snewn(size, char);
8041 bufchain_fetch(&ssh->banner, banner, size);
8042 c_write_untrusted(ssh, banner, size);
8043 sfree(banner);
32874aea 8044 }
6bbce591 8045 bufchain_clear(&ssh->banner);
1408a877 8046 }
ff3187f6 8047 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 8048 logevent("Access granted");
ab18ccff 8049 s->we_are_in = s->userauth_success = TRUE;
1408a877 8050 break;
8051 }
65a22376 8052
42af6a67 8053 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
e955d348 8054 bombout(("Strange packet received during authentication: "
8055 "type %d", pktin->type));
7ffdbc1a 8056 crStopV;
65a22376 8057 }
8058
51470298 8059 s->gotit = FALSE;
65a22376 8060
1408a877 8061 /*
8062 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8063 * we can look at the string in it and know what we can
8064 * helpfully try next.
8065 */
ff3187f6 8066 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
ff3187f6 8067 ssh_pkt_getstring(pktin, &methods, &methlen);
ff3187f6 8068 if (!ssh2_pkt_getbool(pktin)) {
1408a877 8069 /*
8070 * We have received an unequivocal Access
8071 * Denied. This can translate to a variety of
8221906d 8072 * messages, or no message at all.
8073 *
8074 * For forms of authentication which are attempted
8075 * implicitly, by which I mean without printing
8076 * anything in the window indicating that we're
8077 * trying them, we should never print 'Access
8078 * denied'.
8079 *
8080 * If we do print a message saying that we're
8081 * attempting some kind of authentication, it's OK
8082 * to print a followup message saying it failed -
8083 * but the message may sometimes be more specific
8084 * than simply 'Access denied'.
8085 *
1408a877 8086 * Additionally, if we'd just tried password
8087 * authentication, we should break out of this
8088 * whole loop so as to go back to the username
91f57d1f 8089 * prompt (iff we're configured to allow
8090 * username change attempts).
1408a877 8091 */
51470298 8092 if (s->type == AUTH_TYPE_NONE) {
1408a877 8093 /* do nothing */
51470298 8094 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8095 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8096 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8097 c_write_str(ssh, "Server refused our key\r\n");
8221906d 8098 logevent("Server refused our key");
8099 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8100 /* This _shouldn't_ happen except by a
8101 * protocol bug causing client and server to
8102 * disagree on what is a correct signature. */
8103 c_write_str(ssh, "Server refused public-key signature"
8104 " despite accepting key!\r\n");
8105 logevent("Server refused public-key signature"
8106 " despite accepting key!");
51470298 8107 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8221906d 8108 /* quiet, so no c_write */
8109 logevent("Server refused keyboard-interactive authentication");
8110 } else if (s->type==AUTH_TYPE_GSSAPI) {
8111 /* always quiet, so no c_write */
2af4fe8f 8112 /* also, the code down in the GSSAPI block has
8113 * already logged this in the Event Log */
8221906d 8114 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8115 logevent("Keyboard-interactive authentication failed");
8116 c_write_str(ssh, "Access denied\r\n");
8117 } else {
8118 assert(s->type == AUTH_TYPE_PASSWORD);
8119 logevent("Password authentication failed");
51470298 8120 c_write_str(ssh, "Access denied\r\n");
8221906d 8121
8122 if (conf_get_int(ssh->conf, CONF_change_username)) {
6c9dce7c 8123 /* XXX perhaps we should allow
8124 * keyboard-interactive to do this too? */
51470298 8125 s->we_are_in = FALSE;
1408a877 8126 break;
8127 }
8128 }
8129 } else {
51470298 8130 c_write_str(ssh, "Further authentication required\r\n");
1408a877 8131 logevent("Further authentication required");
8132 }
65a22376 8133
51470298 8134 s->can_pubkey =
32874aea 8135 in_commasep_string("publickey", methods, methlen);
51470298 8136 s->can_passwd =
32874aea 8137 in_commasep_string("password", methods, methlen);
4a693cfc 8138 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
761187b6 8139 in_commasep_string("keyboard-interactive", methods, methlen);
1e00c92b 8140#ifndef NO_GSSAPI
8141 if (!ssh->gsslibs)
4a693cfc 8142 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8143 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
b3d375b2 8144 in_commasep_string("gssapi-with-mic", methods, methlen) &&
1e00c92b 8145 ssh->gsslibs->nlibraries > 0;
42af6a67 8146#endif
1408a877 8147 }
65a22376 8148
acab36bc 8149 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
65a22376 8150
94cd7c3a 8151 if (s->can_pubkey && !s->done_agent && s->nkeys) {
0405e71f 8152
1983e559 8153 /*
94cd7c3a 8154 * Attempt public-key authentication using a key from Pageant.
1983e559 8155 */
1983e559 8156
acab36bc 8157 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 8158
94cd7c3a 8159 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8160
8161 /* Unpack key from agent response */
8162 s->pklen = GET_32BIT(s->agentp);
8163 s->agentp += 4;
8164 s->pkblob = (char *)s->agentp;
8165 s->agentp += s->pklen;
8166 s->alglen = GET_32BIT(s->pkblob);
8167 s->alg = s->pkblob + 4;
8168 s->commentlen = GET_32BIT(s->agentp);
8169 s->agentp += 4;
8170 s->commentp = (char *)s->agentp;
8171 s->agentp += s->commentlen;
8172 /* s->agentp now points at next key, if any */
8173
8174 /* See if server will accept it */
8175 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8176 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 8177 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8178 /* service requested */
8179 ssh2_pkt_addstring(s->pktout, "publickey");
8180 /* method */
8181 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8182 ssh2_pkt_addstring_start(s->pktout);
8183 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8184 ssh2_pkt_addstring_start(s->pktout);
8185 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8186 ssh2_pkt_send(ssh, s->pktout);
8187 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
1983e559 8188
94cd7c3a 8189 crWaitUntilV(pktin);
8190 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 8191
94cd7c3a 8192 /* Offer of key refused. */
8193 s->gotit = TRUE;
1983e559 8194
94cd7c3a 8195 } else {
8196
8197 void *vret;
1983e559 8198
94cd7c3a 8199 if (flags & FLAG_VERBOSE) {
8200 c_write_str(ssh, "Authenticating with "
8201 "public key \"");
8202 c_write(ssh, s->commentp, s->commentlen);
8203 c_write_str(ssh, "\" from agent\r\n");
8204 }
1983e559 8205
94cd7c3a 8206 /*
8207 * Server is willing to accept the key.
8208 * Construct a SIGN_REQUEST.
8209 */
8210 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8211 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 8212 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8213 /* service requested */
8214 ssh2_pkt_addstring(s->pktout, "publickey");
8215 /* method */
8216 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8217 ssh2_pkt_addstring_start(s->pktout);
8218 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8219 ssh2_pkt_addstring_start(s->pktout);
8220 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8221
8222 /* Ask agent for signature. */
8223 s->siglen = s->pktout->length - 5 + 4 +
8224 ssh->v2_session_id_len;
8225 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8226 s->siglen -= 4;
8227 s->len = 1; /* message type */
8228 s->len += 4 + s->pklen; /* key blob */
8229 s->len += 4 + s->siglen; /* data to sign */
8230 s->len += 4; /* flags */
8231 s->agentreq = snewn(4 + s->len, char);
8232 PUT_32BIT(s->agentreq, s->len);
8233 s->q = s->agentreq + 4;
8234 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8235 PUT_32BIT(s->q, s->pklen);
8236 s->q += 4;
8237 memcpy(s->q, s->pkblob, s->pklen);
8238 s->q += s->pklen;
8239 PUT_32BIT(s->q, s->siglen);
8240 s->q += 4;
8241 /* Now the data to be signed... */
8242 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8243 PUT_32BIT(s->q, ssh->v2_session_id_len);
51470298 8244 s->q += 4;
94cd7c3a 8245 }
8246 memcpy(s->q, ssh->v2_session_id,
8247 ssh->v2_session_id_len);
8248 s->q += ssh->v2_session_id_len;
8249 memcpy(s->q, s->pktout->data + 5,
8250 s->pktout->length - 5);
8251 s->q += s->pktout->length - 5;
8252 /* And finally the (zero) flags word. */
8253 PUT_32BIT(s->q, 0);
8254 if (!agent_query(s->agentreq, s->len + 4,
8255 &vret, &s->retlen,
8256 ssh_agent_callback, ssh)) {
8257 do {
8258 crReturnV;
8259 if (pktin) {
8260 bombout(("Unexpected data from server"
8261 " while waiting for agent"
8262 " response"));
8263 crStopV;
1983e559 8264 }
94cd7c3a 8265 } while (pktin || inlen > 0);
8266 vret = ssh->agent_response;
8267 s->retlen = ssh->agent_response_len;
8268 }
8269 s->ret = vret;
8270 sfree(s->agentreq);
8271 if (s->ret) {
8272 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
8273 logevent("Sending Pageant's response");
8274 ssh2_add_sigblob(ssh, s->pktout,
8275 s->pkblob, s->pklen,
8276 s->ret + 9,
8277 GET_32BIT(s->ret + 5));
8278 ssh2_pkt_send(ssh, s->pktout);
8279 s->type = AUTH_TYPE_PUBLICKEY;
8280 } else {
8281 /* FIXME: less drastic response */
8282 bombout(("Pageant failed to answer challenge"));
8283 crStopV;
1983e559 8284 }
8285 }
1983e559 8286 }
94cd7c3a 8287
8288 /* Do we have any keys left to try? */
8289 if (s->pkblob_in_agent) {
8290 s->done_agent = TRUE;
8291 s->tried_pubkey_config = TRUE;
8292 } else {
8293 s->keyi++;
8294 if (s->keyi >= s->nkeys)
8295 s->done_agent = TRUE;
8296 }
1983e559 8297
edd0cb8a 8298 } else if (s->can_pubkey && s->publickey_blob &&
8299 !s->tried_pubkey_config) {
65a22376 8300
edd0cb8a 8301 struct ssh2_userkey *key; /* not live over crReturn */
8302 char *passphrase; /* not live over crReturn */
65a22376 8303
acab36bc 8304 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 8305
edd0cb8a 8306 s->tried_pubkey_config = TRUE;
8307
65a22376 8308 /*
1408a877 8309 * Try the public key supplied in the configuration.
8310 *
8311 * First, offer the public blob to see if the server is
8312 * willing to accept it.
65a22376 8313 */
ff3187f6 8314 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8315 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8316 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8317 /* service requested */
8318 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8319 ssh2_pkt_addbool(s->pktout, FALSE);
8320 /* no signature included */
8321 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8322 ssh2_pkt_addstring_start(s->pktout);
8323 ssh2_pkt_addstring_data(s->pktout,
8324 (char *)s->publickey_blob,
8325 s->publickey_bloblen);
ff3187f6 8326 ssh2_pkt_send(ssh, s->pktout);
edd0cb8a 8327 logevent("Offered public key");
ff3187f6 8328
8329 crWaitUntilV(pktin);
edd0cb8a 8330 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8331 /* Key refused. Give up. */
8332 s->gotit = TRUE; /* reconsider message next loop */
8333 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8334 continue; /* process this new message */
45068b27 8335 }
edd0cb8a 8336 logevent("Offer of public key accepted");
af659722 8337
45068b27 8338 /*
edd0cb8a 8339 * Actually attempt a serious authentication using
8340 * the key.
45068b27 8341 */
edd0cb8a 8342 if (flags & FLAG_VERBOSE) {
8343 c_write_str(ssh, "Authenticating with public key \"");
8344 c_write_str(ssh, s->publickey_comment);
8345 c_write_str(ssh, "\"\r\n");
8346 }
8347 key = NULL;
8348 while (!key) {
8349 const char *error; /* not live over crReturn */
8350 if (s->publickey_encrypted) {
8351 /*
8352 * Get a passphrase from the user.
8353 */
8354 int ret; /* need not be kept over crReturn */
8355 s->cur_prompt = new_prompts(ssh->frontend);
8356 s->cur_prompt->to_server = FALSE;
8357 s->cur_prompt->name = dupstr("SSH key passphrase");
8358 add_prompt(s->cur_prompt,
8359 dupprintf("Passphrase for key \"%.100s\": ",
8360 s->publickey_comment),
b61f81bc 8361 FALSE);
edd0cb8a 8362 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8363 while (ret < 0) {
8364 ssh->send_ok = 1;
8365 crWaitUntilV(!pktin);
8366 ret = get_userpass_input(s->cur_prompt,
8367 in, inlen);
8368 ssh->send_ok = 0;
8369 }
8370 if (!ret) {
8371 /* Failed to get a passphrase. Terminate. */
8372 free_prompts(s->cur_prompt);
8373 ssh_disconnect(ssh, NULL,
8374 "Unable to authenticate",
8375 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8376 TRUE);
8377 crStopV;
85fdbe25 8378 }
edd0cb8a 8379 passphrase =
8380 dupstr(s->cur_prompt->prompts[0]->result);
8381 free_prompts(s->cur_prompt);
45068b27 8382 } else {
edd0cb8a 8383 passphrase = NULL; /* no passphrase needed */
45068b27 8384 }
1408a877 8385
edd0cb8a 8386 /*
8387 * Try decrypting the key.
8388 */
4a693cfc 8389 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8390 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
edd0cb8a 8391 if (passphrase) {
8392 /* burn the evidence */
dfb88efd 8393 smemclr(passphrase, strlen(passphrase));
edd0cb8a 8394 sfree(passphrase);
8395 }
8396 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8397 if (passphrase &&
8398 (key == SSH2_WRONG_PASSPHRASE)) {
8399 c_write_str(ssh, "Wrong passphrase\r\n");
8400 key = NULL;
8401 /* and loop again */
8402 } else {
8403 c_write_str(ssh, "Unable to load private key (");
8404 c_write_str(ssh, error);
8405 c_write_str(ssh, ")\r\n");
8406 key = NULL;
8407 break; /* try something else */
8408 }
1408a877 8409 }
65a22376 8410 }
65a22376 8411
edd0cb8a 8412 if (key) {
1dd353b5 8413 unsigned char *pkblob, *sigblob, *sigdata;
8414 int pkblob_len, sigblob_len, sigdata_len;
edd0cb8a 8415 int p;
65a22376 8416
1408a877 8417 /*
8418 * We have loaded the private key and the server
8419 * has announced that it's willing to accept it.
8420 * Hallelujah. Generate a signature and send it.
8421 */
ff3187f6 8422 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8423 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8424 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8425 /* service requested */
8426 ssh2_pkt_addstring(s->pktout, "publickey");
8427 /* method */
ff3187f6 8428 ssh2_pkt_addbool(s->pktout, TRUE);
edd0cb8a 8429 /* signature follows */
ff3187f6 8430 ssh2_pkt_addstring(s->pktout, key->alg->name);
edd0cb8a 8431 pkblob = key->alg->public_blob(key->data,
8432 &pkblob_len);
ff3187f6 8433 ssh2_pkt_addstring_start(s->pktout);
edd0cb8a 8434 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8435 pkblob_len);
1408a877 8436
8437 /*
8438 * The data to be signed is:
8439 *
8440 * string session-id
8441 *
8442 * followed by everything so far placed in the
8443 * outgoing packet.
8444 */
b672f405 8445 sigdata_len = s->pktout->length - 5 + 4 +
8446 ssh->v2_session_id_len;
edd0cb8a 8447 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8448 sigdata_len -= 4;
92d60585 8449 sigdata = snewn(sigdata_len, unsigned char);
edd0cb8a 8450 p = 0;
8451 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8452 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8453 p += 4;
8454 }
b672f405 8455 memcpy(sigdata+p, ssh->v2_session_id,
8456 ssh->v2_session_id_len);
8457 p += ssh->v2_session_id_len;
ff3187f6 8458 memcpy(sigdata+p, s->pktout->data + 5,
8459 s->pktout->length - 5);
edd0cb8a 8460 p += s->pktout->length - 5;
8461 assert(p == sigdata_len);
d8baa528 8462 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 8463 sigdata_len, &sigblob_len);
ff3187f6 8464 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 8465 sigblob, sigblob_len);
8466 sfree(pkblob);
8467 sfree(sigblob);
1408a877 8468 sfree(sigdata);
8469
ff3187f6 8470 ssh2_pkt_send(ssh, s->pktout);
8221906d 8471 logevent("Sent public key signature");
51470298 8472 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 8473 key->alg->freekey(key->data);
1408a877 8474 }
edd0cb8a 8475
42af6a67 8476#ifndef NO_GSSAPI
8477 } else if (s->can_gssapi && !s->tried_gssapi) {
8478
8479 /* GSSAPI Authentication */
8480
86557057 8481 int micoffset, len;
8482 char *data;
42af6a67 8483 Ssh_gss_buf mic;
8484 s->type = AUTH_TYPE_GSSAPI;
8485 s->tried_gssapi = TRUE;
8486 s->gotit = TRUE;
8487 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8488
b3d375b2 8489 /*
8490 * Pick the highest GSS library on the preference
8491 * list.
8492 */
8493 {
8494 int i, j;
8495 s->gsslib = NULL;
8496 for (i = 0; i < ngsslibs; i++) {
4a693cfc 8497 int want_id = conf_get_int_int(ssh->conf,
8498 CONF_ssh_gsslist, i);
1e00c92b 8499 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8500 if (ssh->gsslibs->libraries[j].id == want_id) {
8501 s->gsslib = &ssh->gsslibs->libraries[j];
b3d375b2 8502 goto got_gsslib; /* double break */
8503 }
8504 }
8505 got_gsslib:
8506 /*
8507 * We always expect to have found something in
8508 * the above loop: we only came here if there
8509 * was at least one viable GSS library, and the
8510 * preference list should always mention
8511 * everything and only change the order.
8512 */
8513 assert(s->gsslib);
8514 }
8515
8516 if (s->gsslib->gsslogmsg)
8517 logevent(s->gsslib->gsslogmsg);
8518
42af6a67 8519 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8520 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8521 ssh2_pkt_addstring(s->pktout, ssh->username);
42af6a67 8522 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8523 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8221906d 8524 logevent("Attempting GSSAPI authentication");
42af6a67 8525
8526 /* add mechanism info */
b3d375b2 8527 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
42af6a67 8528
8529 /* number of GSSAPI mechanisms */
8530 ssh2_pkt_adduint32(s->pktout,1);
8531
8532 /* length of OID + 2 */
86557057 8533 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
42af6a67 8534 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8535
8536 /* length of OID */
86557057 8537 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
42af6a67 8538
86557057 8539 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8540 s->gss_buf.length);
42af6a67 8541 ssh2_pkt_send(ssh, s->pktout);
8542 crWaitUntilV(pktin);
8543 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8544 logevent("GSSAPI authentication request refused");
8545 continue;
8546 }
8547
8548 /* check returned packet ... */
8549
86557057 8550 ssh_pkt_getstring(pktin, &data, &len);
8551 s->gss_rcvtok.value = data;
8552 s->gss_rcvtok.length = len;
8553 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8554 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8555 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8556 memcmp((char *)s->gss_rcvtok.value + 2,
8557 s->gss_buf.value,s->gss_buf.length) ) {
42af6a67 8558 logevent("GSSAPI authentication - wrong response from server");
8559 continue;
8560 }
8561
8562 /* now start running */
b3d375b2 8563 s->gss_stat = s->gsslib->import_name(s->gsslib,
8564 ssh->fullhostname,
8565 &s->gss_srv_name);
42af6a67 8566 if (s->gss_stat != SSH_GSS_OK) {
8567 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8568 logevent("GSSAPI import name failed - Bad service name");
8569 else
8570 logevent("GSSAPI import name failed");
8571 continue;
8572 }
8573
8574 /* fetch TGT into GSS engine */
b3d375b2 8575 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
42af6a67 8576
8577 if (s->gss_stat != SSH_GSS_OK) {
8578 logevent("GSSAPI authentication failed to get credentials");
b3d375b2 8579 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
42af6a67 8580 continue;
8581 }
8582
8583 /* initial tokens are empty */
86557057 8584 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
99a3b3c9 8585 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
42af6a67 8586
8587 /* now enter the loop */
8588 do {
b3d375b2 8589 s->gss_stat = s->gsslib->init_sec_context
8590 (s->gsslib,
8591 &s->gss_ctx,
8592 s->gss_srv_name,
4a693cfc 8593 conf_get_int(ssh->conf, CONF_gssapifwd),
b3d375b2 8594 &s->gss_rcvtok,
8595 &s->gss_sndtok);
42af6a67 8596
8597 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8598 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8599 logevent("GSSAPI authentication initialisation failed");
8600
b3d375b2 8601 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8602 &s->gss_buf) == SSH_GSS_OK) {
86557057 8603 logevent(s->gss_buf.value);
8604 sfree(s->gss_buf.value);
42af6a67 8605 }
8606
8607 break;
8608 }
8609 logevent("GSSAPI authentication initialised");
8610
8611 /* Client and server now exchange tokens until GSSAPI
8612 * no longer says CONTINUE_NEEDED */
8613
86557057 8614 if (s->gss_sndtok.length != 0) {
42af6a67 8615 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8616 ssh_pkt_addstring_start(s->pktout);
86557057 8617 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
42af6a67 8618 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8619 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
42af6a67 8620 }
8621
8622 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8623 crWaitUntilV(pktin);
8624 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8625 logevent("GSSAPI authentication - bad server response");
8626 s->gss_stat = SSH_GSS_FAILURE;
8627 break;
8628 }
86557057 8629 ssh_pkt_getstring(pktin, &data, &len);
8630 s->gss_rcvtok.value = data;
8631 s->gss_rcvtok.length = len;
42af6a67 8632 }
8633 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8634
8635 if (s->gss_stat != SSH_GSS_OK) {
b3d375b2 8636 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8637 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8638 continue;
8639 }
8640 logevent("GSSAPI authentication loop finished OK");
8641
8642 /* Now send the MIC */
8643
8644 s->pktout = ssh2_pkt_init(0);
8645 micoffset = s->pktout->length;
8646 ssh_pkt_addstring_start(s->pktout);
8647 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8648 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8649 ssh_pkt_addstring(s->pktout, ssh->username);
42af6a67 8650 ssh_pkt_addstring(s->pktout, "ssh-connection");
8651 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8652
86557057 8653 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8654 s->gss_buf.length = s->pktout->length - micoffset;
42af6a67 8655
b3d375b2 8656 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
42af6a67 8657 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8658 ssh_pkt_addstring_start(s->pktout);
86557057 8659 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
42af6a67 8660 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8661 s->gsslib->free_mic(s->gsslib, &mic);
42af6a67 8662
8663 s->gotit = FALSE;
8664
b3d375b2 8665 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8666 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8667 continue;
8668#endif
edd0cb8a 8669 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8670
8671 /*
8672 * Keyboard-interactive authentication.
8673 */
edd0cb8a 8674
edd0cb8a 8675 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8676
acab36bc 8677 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
edd0cb8a 8678
8679 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8680 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8681 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8682 /* service requested */
8683 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8684 /* method */
8685 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8686 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8687 ssh2_pkt_send(ssh, s->pktout);
8221906d 8688
8689 logevent("Attempting keyboard-interactive authentication");
edd0cb8a 8690
8691 crWaitUntilV(pktin);
8692 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8693 /* Server is not willing to do keyboard-interactive
b8e3173d 8694 * at all (or, bizarrely but legally, accepts the
8695 * user without actually issuing any prompts).
8696 * Give up on it entirely. */
edd0cb8a 8697 s->gotit = TRUE;
edd0cb8a 8698 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8699 s->kbd_inter_refused = TRUE; /* don't try it again */
8700 continue;
8701 }
8702
8703 /*
b8e3173d 8704 * Loop while the server continues to send INFO_REQUESTs.
edd0cb8a 8705 */
b8e3173d 8706 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
edd0cb8a 8707
b8e3173d 8708 char *name, *inst, *lang;
8709 int name_len, inst_len, lang_len;
8710 int i;
8711
8712 /*
8713 * We've got a fresh USERAUTH_INFO_REQUEST.
8714 * Get the preamble and start building a prompt.
8715 */
8716 ssh_pkt_getstring(pktin, &name, &name_len);
8717 ssh_pkt_getstring(pktin, &inst, &inst_len);
8718 ssh_pkt_getstring(pktin, &lang, &lang_len);
8719 s->cur_prompt = new_prompts(ssh->frontend);
8720 s->cur_prompt->to_server = TRUE;
edd0cb8a 8721
b8e3173d 8722 /*
9ea10e78 8723 * Get any prompt(s) from the packet.
b8e3173d 8724 */
8725 s->num_prompts = ssh_pkt_getuint32(pktin);
8726 for (i = 0; i < s->num_prompts; i++) {
8727 char *prompt;
8728 int prompt_len;
8729 int echo;
8730 static char noprompt[] =
8731 "<server failed to send prompt>: ";
8732
8733 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8734 echo = ssh2_pkt_getbool(pktin);
8735 if (!prompt_len) {
8736 prompt = noprompt;
8737 prompt_len = lenof(noprompt)-1;
8738 }
8739 add_prompt(s->cur_prompt,
8740 dupprintf("%.*s", prompt_len, prompt),
b61f81bc 8741 echo);
edd0cb8a 8742 }
b8e3173d 8743
9874c9d7 8744 if (name_len) {
8745 /* FIXME: better prefix to distinguish from
8746 * local prompts? */
8747 s->cur_prompt->name =
8748 dupprintf("SSH server: %.*s", name_len, name);
8749 s->cur_prompt->name_reqd = TRUE;
8750 } else {
8751 s->cur_prompt->name =
8752 dupstr("SSH server authentication");
8753 s->cur_prompt->name_reqd = FALSE;
8754 }
8755 /* We add a prefix to try to make it clear that a prompt
8756 * has come from the server.
8757 * FIXME: ugly to print "Using..." in prompt _every_
8758 * time round. Can this be done more subtly? */
8759 /* Special case: for reasons best known to themselves,
8760 * some servers send k-i requests with no prompts and
8761 * nothing to display. Keep quiet in this case. */
8762 if (s->num_prompts || name_len || inst_len) {
8763 s->cur_prompt->instruction =
8764 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8765 inst_len ? "\n" : "", inst_len, inst);
8766 s->cur_prompt->instr_reqd = TRUE;
8767 } else {
8768 s->cur_prompt->instr_reqd = FALSE;
8769 }
8770
b8e3173d 8771 /*
9ea10e78 8772 * Display any instructions, and get the user's
8773 * response(s).
b8e3173d 8774 */
9ea10e78 8775 {
b8e3173d 8776 int ret; /* not live over crReturn */
8777 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8778 while (ret < 0) {
8779 ssh->send_ok = 1;
8780 crWaitUntilV(!pktin);
8781 ret = get_userpass_input(s->cur_prompt, in, inlen);
8782 ssh->send_ok = 0;
8783 }
8784 if (!ret) {
8785 /*
8786 * Failed to get responses. Terminate.
8787 */
8788 free_prompts(s->cur_prompt);
8789 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8790 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8791 TRUE);
8792 crStopV;
8793 }
edd0cb8a 8794 }
b8e3173d 8795
8796 /*
9ea10e78 8797 * Send the response(s) to the server.
b8e3173d 8798 */
8799 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
b8e3173d 8800 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8801 for (i=0; i < s->num_prompts; i++) {
8802 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8803 ssh2_pkt_addstring(s->pktout,
8804 s->cur_prompt->prompts[i]->result);
8805 end_log_omission(ssh, s->pktout);
8806 }
18524056 8807 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
b8e3173d 8808
c69784c0 8809 /*
8810 * Free the prompts structure from this iteration.
8811 * If there's another, a new one will be allocated
8812 * when we return to the top of this while loop.
8813 */
8814 free_prompts(s->cur_prompt);
8815
b8e3173d 8816 /*
8817 * Get the next packet in case it's another
8818 * INFO_REQUEST.
8819 */
8820 crWaitUntilV(pktin);
8821
edd0cb8a 8822 }
8823
8824 /*
b8e3173d 8825 * We should have SUCCESS or FAILURE now.
edd0cb8a 8826 */
b8e3173d 8827 s->gotit = TRUE;
edd0cb8a 8828
8829 } else if (s->can_passwd) {
8830
8831 /*
8832 * Plain old password authentication.
8833 */
8834 int ret; /* not live over crReturn */
e955d348 8835 int changereq_first_time; /* not live over crReturn */
edd0cb8a 8836
acab36bc 8837 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
edd0cb8a 8838
8839 s->cur_prompt = new_prompts(ssh->frontend);
8840 s->cur_prompt->to_server = TRUE;
8841 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 8842 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
8843 ssh->username,
edd0cb8a 8844 ssh->savedhost),
b61f81bc 8845 FALSE);
edd0cb8a 8846
8847 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8848 while (ret < 0) {
8849 ssh->send_ok = 1;
8850 crWaitUntilV(!pktin);
8851 ret = get_userpass_input(s->cur_prompt, in, inlen);
8852 ssh->send_ok = 0;
8853 }
8854 if (!ret) {
8855 /*
8856 * Failed to get responses. Terminate.
8857 */
8858 free_prompts(s->cur_prompt);
8859 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8860 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8861 TRUE);
8862 crStopV;
8863 }
e955d348 8864 /*
8865 * Squirrel away the password. (We may need it later if
8866 * asked to change it.)
8867 */
8868 s->password = dupstr(s->cur_prompt->prompts[0]->result);
8869 free_prompts(s->cur_prompt);
edd0cb8a 8870
8871 /*
8872 * Send the password packet.
8873 *
95d2d262 8874 * We pad out the password packet to 256 bytes to make
8875 * it harder for an attacker to find the length of the
8876 * user's password.
1408a877 8877 *
95d2d262 8878 * Anyone using a password longer than 256 bytes
8879 * probably doesn't have much to worry about from
1408a877 8880 * people who find out how long their password is!
65a22376 8881 */
ff3187f6 8882 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8883 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8884 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8885 /* service requested */
ff3187f6 8886 ssh2_pkt_addstring(s->pktout, "password");
8887 ssh2_pkt_addbool(s->pktout, FALSE);
8888 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
e955d348 8889 ssh2_pkt_addstring(s->pktout, s->password);
ff3187f6 8890 end_log_omission(ssh, s->pktout);
18524056 8891 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
0d43337a 8892 logevent("Sent password");
28f4d4f0 8893 s->type = AUTH_TYPE_PASSWORD;
edd0cb8a 8894
e955d348 8895 /*
8896 * Wait for next packet, in case it's a password change
8897 * request.
8898 */
8899 crWaitUntilV(pktin);
8900 changereq_first_time = TRUE;
8901
8902 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
8903
8904 /*
8905 * We're being asked for a new password
8906 * (perhaps not for the first time).
8907 * Loop until the server accepts it.
8908 */
8909
8910 int got_new = FALSE; /* not live over crReturn */
8911 char *prompt; /* not live over crReturn */
8912 int prompt_len; /* not live over crReturn */
8913
8914 {
8915 char *msg;
8916 if (changereq_first_time)
8917 msg = "Server requested password change";
8918 else
8919 msg = "Server rejected new password";
8920 logevent(msg);
8921 c_write_str(ssh, msg);
8922 c_write_str(ssh, "\r\n");
8923 }
8924
8925 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8926
8927 s->cur_prompt = new_prompts(ssh->frontend);
8928 s->cur_prompt->to_server = TRUE;
8929 s->cur_prompt->name = dupstr("New SSH password");
8930 s->cur_prompt->instruction =
8931 dupprintf("%.*s", prompt_len, prompt);
8932 s->cur_prompt->instr_reqd = TRUE;
d9add7bc 8933 /*
8934 * There's no explicit requirement in the protocol
8935 * for the "old" passwords in the original and
8936 * password-change messages to be the same, and
8937 * apparently some Cisco kit supports password change
8938 * by the user entering a blank password originally
8939 * and the real password subsequently, so,
8940 * reluctantly, we prompt for the old password again.
8941 *
8942 * (On the other hand, some servers don't even bother
8943 * to check this field.)
8944 */
8945 add_prompt(s->cur_prompt,
8946 dupstr("Current password (blank for previously entered password): "),
b61f81bc 8947 FALSE);
e955d348 8948 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
b61f81bc 8949 FALSE);
e955d348 8950 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
b61f81bc 8951 FALSE);
e955d348 8952
8953 /*
8954 * Loop until the user manages to enter the same
8955 * password twice.
8956 */
8957 while (!got_new) {
8958
8959 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8960 while (ret < 0) {
8961 ssh->send_ok = 1;
8962 crWaitUntilV(!pktin);
8963 ret = get_userpass_input(s->cur_prompt, in, inlen);
8964 ssh->send_ok = 0;
8965 }
8966 if (!ret) {
8967 /*
8968 * Failed to get responses. Terminate.
8969 */
8970 /* burn the evidence */
8971 free_prompts(s->cur_prompt);
dfb88efd 8972 smemclr(s->password, strlen(s->password));
e955d348 8973 sfree(s->password);
8974 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8975 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8976 TRUE);
8977 crStopV;
8978 }
8979
8980 /*
d9add7bc 8981 * If the user specified a new original password
8982 * (IYSWIM), overwrite any previously specified
8983 * one.
8984 * (A side effect is that the user doesn't have to
8985 * re-enter it if they louse up the new password.)
8986 */
8987 if (s->cur_prompt->prompts[0]->result[0]) {
dfb88efd 8988 smemclr(s->password, strlen(s->password));
d9add7bc 8989 /* burn the evidence */
8990 sfree(s->password);
8991 s->password =
8992 dupstr(s->cur_prompt->prompts[0]->result);
8993 }
8994
8995 /*
8996 * Check the two new passwords match.
e955d348 8997 */
d9add7bc 8998 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
8999 s->cur_prompt->prompts[2]->result)
e955d348 9000 == 0);
9001 if (!got_new)
9002 /* They don't. Silly user. */
9003 c_write_str(ssh, "Passwords do not match\r\n");
9004
9005 }
9006
9007 /*
9008 * Send the new password (along with the old one).
9009 * (see above for padding rationale)
9010 */
9011 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 9012 ssh2_pkt_addstring(s->pktout, ssh->username);
e955d348 9013 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9014 /* service requested */
9015 ssh2_pkt_addstring(s->pktout, "password");
9016 ssh2_pkt_addbool(s->pktout, TRUE);
9017 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
9018 ssh2_pkt_addstring(s->pktout, s->password);
9019 ssh2_pkt_addstring(s->pktout,
d9add7bc 9020 s->cur_prompt->prompts[1]->result);
e955d348 9021 free_prompts(s->cur_prompt);
9022 end_log_omission(ssh, s->pktout);
18524056 9023 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
e955d348 9024 logevent("Sent new password");
9025
9026 /*
9027 * Now see what the server has to say about it.
9028 * (If it's CHANGEREQ again, it's not happy with the
9029 * new password.)
9030 */
9031 crWaitUntilV(pktin);
9032 changereq_first_time = FALSE;
9033
9034 }
9035
9036 /*
9037 * We need to reexamine the current pktin at the top
9038 * of the loop. Either:
9039 * - we weren't asked to change password at all, in
9040 * which case it's a SUCCESS or FAILURE with the
9041 * usual meaning
9042 * - we sent a new password, and the server was
9043 * either OK with it (SUCCESS or FAILURE w/partial
9044 * success) or unhappy with the _old_ password
9045 * (FAILURE w/o partial success)
9046 * In any of these cases, we go back to the top of
9047 * the loop and start again.
9048 */
9049 s->gotit = TRUE;
9050
9051 /*
9052 * We don't need the old password any more, in any
9053 * case. Burn the evidence.
9054 */
dfb88efd 9055 smemclr(s->password, strlen(s->password));
e955d348 9056 sfree(s->password);
9057
1408a877 9058 } else {
854caca5 9059 char *str = dupprintf("No supported authentication methods available"
9060 " (server sent: %.*s)",
9061 methlen, methods);
edd0cb8a 9062
854caca5 9063 ssh_disconnect(ssh, str,
9e296bfa 9064 "No supported authentication methods available",
9065 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9066 FALSE);
854caca5 9067 sfree(str);
9068
7ffdbc1a 9069 crStopV;
edd0cb8a 9070
65a22376 9071 }
edd0cb8a 9072
65a22376 9073 }
a1a1fae4 9074 }
6bbce591 9075 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7cca0d81 9076
edd0cb8a 9077 /* Clear up various bits and pieces from authentication. */
9078 if (s->publickey_blob) {
9079 sfree(s->publickey_blob);
9080 sfree(s->publickey_comment);
9081 }
94cd7c3a 9082 if (s->agent_response)
9083 sfree(s->agent_response);
edd0cb8a 9084
ab18ccff 9085 if (s->userauth_success) {
9086 /*
9087 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9088 * packets since. Signal the transport layer to consider enacting
9089 * delayed compression.
9090 *
9091 * (Relying on we_are_in is not sufficient, as
9092 * draft-miller-secsh-compression-delayed is quite clear that it
9093 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9094 * become set for other reasons.)
9095 */
9096 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9097 }
9098
7cca0d81 9099 /*
a1a1fae4 9100 * Now the connection protocol has started, one way or another.
7cca0d81 9101 */
9102
0ed48730 9103 ssh->channels = newtree234(ssh_channelcmp);
9104
7cca0d81 9105 /*
b09eaa88 9106 * Set up handlers for some connection protocol messages, so we
9107 * don't have to handle them repeatedly in this coroutine.
9108 */
9109 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9110 ssh2_msg_channel_window_adjust;
51df0ab5 9111 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9112 ssh2_msg_global_request;
b09eaa88 9113
9114 /*
0ed48730 9115 * Create the main session channel.
7cca0d81 9116 */
4a693cfc 9117 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
feb02b4e 9118 ssh->mainchan = NULL;
4a693cfc 9119 } else if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
feb02b4e 9120 /*
9121 * Just start a direct-tcpip channel and use it as the main
9122 * channel.
9123 */
9124 ssh->mainchan = snew(struct ssh_channel);
9125 ssh->mainchan->ssh = ssh;
94bdfe40 9126 ssh2_channel_init(ssh->mainchan);
23828b7e 9127 logeventf(ssh,
9128 "Opening direct-tcpip channel to %s:%d in place of session",
4a693cfc 9129 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9130 conf_get_int(ssh->conf, CONF_ssh_nc_port));
feb02b4e 9131 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
9132 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
9133 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
feb02b4e 9134 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
9135 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
4a693cfc 9136 ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_ssh_nc_host));
9137 ssh2_pkt_adduint32(s->pktout, conf_get_int(ssh->conf, CONF_ssh_nc_port));
feb02b4e 9138 /*
23828b7e 9139 * There's nothing meaningful to put in the originator
9140 * fields, but some servers insist on syntactically correct
9141 * information.
feb02b4e 9142 */
9143 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
9144 ssh2_pkt_adduint32(s->pktout, 0);
9145 ssh2_pkt_send(ssh, s->pktout);
9146
9147 crWaitUntilV(pktin);
9148 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9149 bombout(("Server refused to open a direct-tcpip channel"));
9150 crStopV;
9151 /* FIXME: error data comes back in FAILURE packet */
9152 }
9153 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9154 bombout(("Server's channel confirmation cited wrong channel"));
9155 crStopV;
9156 }
9157 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9158 ssh->mainchan->halfopen = FALSE;
9159 ssh->mainchan->type = CHAN_MAINSESSION;
feb02b4e 9160 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9161 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
feb02b4e 9162 add234(ssh->channels, ssh->mainchan);
9163 update_specials_menu(ssh->frontend);
23828b7e 9164 logevent("Opened direct-tcpip channel");
feb02b4e 9165 ssh->ncmode = TRUE;
9166 } else {
0ed48730 9167 ssh->mainchan = snew(struct ssh_channel);
9168 ssh->mainchan->ssh = ssh;
94bdfe40 9169 ssh2_channel_init(ssh->mainchan);
ff3187f6 9170 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
9171 ssh2_pkt_addstring(s->pktout, "session");
9172 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
ff3187f6 9173 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 9174 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 9175 ssh2_pkt_send(ssh, s->pktout);
9176 crWaitUntilV(pktin);
9177 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 9178 bombout(("Server refused to open a session"));
9179 crStopV;
9180 /* FIXME: error data comes back in FAILURE packet */
9181 }
ff3187f6 9182 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 9183 bombout(("Server's channel confirmation cited wrong channel"));
9184 crStopV;
9185 }
ff3187f6 9186 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 9187 ssh->mainchan->halfopen = FALSE;
0ed48730 9188 ssh->mainchan->type = CHAN_MAINSESSION;
ff3187f6 9189 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9190 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 9191 add234(ssh->channels, ssh->mainchan);
62638676 9192 update_specials_menu(ssh->frontend);
0ed48730 9193 logevent("Opened channel for session");
feb02b4e 9194 ssh->ncmode = FALSE;
9195 }
7cca0d81 9196
9197 /*
51df0ab5 9198 * Now we have a channel, make dispatch table entries for
9199 * general channel-based messages.
9200 */
9201 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9202 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9203 ssh2_msg_channel_data;
9204 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9205 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9206 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9207 ssh2_msg_channel_open_confirmation;
9208 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9209 ssh2_msg_channel_open_failure;
9210 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9211 ssh2_msg_channel_request;
9212 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9213 ssh2_msg_channel_open;
ebbc254d 9214 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9215 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9216
51df0ab5 9217
4a693cfc 9218 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
3361b80a 9219 /*
9220 * This message indicates to the server that we promise
9221 * not to try to run any other channel in parallel with
9222 * this one, so it's safe for it to advertise a very large
9223 * window and leave the flow control to TCP.
9224 */
134f5ece 9225 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9226 "simple@putty.projects.tartarus.org",
9227 NULL, NULL);
3361b80a 9228 ssh2_pkt_send(ssh, s->pktout);
9229 }
9230
51df0ab5 9231 /*
c99deca4 9232 * Enable port forwardings.
9233 */
9234 ssh_setup_portfwd(ssh, ssh->conf);
9235
9236 /*
ebbc254d 9237 * Send the CHANNEL_REQUESTS for the main channel. Each one is
9238 * handled by its own little asynchronous co-routine.
c99deca4 9239 */
9240
9241 /*
783415f8 9242 * Potentially enable X11 forwarding.
9243 */
ebbc254d 9244 ssh2_maybe_setup_x11(ssh->mainchan, NULL, NULL);
bc240b21 9245
9246 /*
36c2a3e9 9247 * Potentially enable agent forwarding.
9248 */
ebbc254d 9249 ssh2_maybe_setup_agent(ssh->mainchan, NULL, NULL);
36c2a3e9 9250
9251 /*
7cca0d81 9252 * Now allocate a pty for the session.
9253 */
ebbc254d 9254 ssh2_maybe_setup_pty(ssh->mainchan, NULL, NULL);
7cca0d81 9255
9256 /*
73feed4f 9257 * Send environment variables.
73feed4f 9258 */
ebbc254d 9259 ssh2_setup_env(ssh->mainchan, NULL, NULL);
73feed4f 9260
9261 /*
fd5e5847 9262 * Start a shell or a remote command. We may have to attempt
9263 * this twice if the config data has provided a second choice
9264 * of command.
7cca0d81 9265 */
feb02b4e 9266 if (ssh->mainchan && !ssh->ncmode) while (1) {
fd5e5847 9267 int subsys;
9268 char *cmd;
9269
51470298 9270 if (ssh->fallback_cmd) {
4a693cfc 9271 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9272 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
fd5e5847 9273 } else {
4a693cfc 9274 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9275 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
fd5e5847 9276 }
9277
fd5e5847 9278 if (subsys) {
134f5ece 9279 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
9280 ssh2_response_authconn, NULL);
ff3187f6 9281 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 9282 } else if (*cmd) {
134f5ece 9283 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
9284 ssh2_response_authconn, NULL);
ff3187f6 9285 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 9286 } else {
134f5ece 9287 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
9288 ssh2_response_authconn, NULL);
32874aea 9289 }
ff3187f6 9290 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 9291
9292 crWaitUntilV(pktin);
9293
ff3187f6 9294 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9295 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 9296 bombout(("Unexpected response to shell/command request:"
ff3187f6 9297 " packet type %d", pktin->type));
7ffdbc1a 9298 crStopV;
fd5e5847 9299 }
9300 /*
9301 * We failed to start the command. If this is the
9302 * fallback command, we really are finished; if it's
9303 * not, and if the fallback command exists, try falling
9304 * back to it before complaining.
9305 */
4a693cfc 9306 if (!ssh->fallback_cmd &&
9307 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
fd5e5847 9308 logevent("Primary command failed; attempting fallback");
51470298 9309 ssh->fallback_cmd = TRUE;
fd5e5847 9310 continue;
9311 }
6b5cf8b4 9312 bombout(("Server refused to start a shell/command"));
7ffdbc1a 9313 crStopV;
fd5e5847 9314 } else {
9315 logevent("Started a shell/command");
32874aea 9316 }
fd5e5847 9317 break;
7cca0d81 9318 }
9319
51470298 9320 ssh->state = SSH_STATE_SESSION;
9321 if (ssh->size_needed)
9322 ssh_size(ssh, ssh->term_width, ssh->term_height);
9323 if (ssh->eof_needed)
9324 ssh_special(ssh, TS_EOF);
6e48c3fe 9325
7cca0d81 9326 /*
0e443c99 9327 * All the initial channel requests are done, so install the default
39d830e4 9328 * response handler.
0e443c99 9329 */
39d830e4 9330 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9331 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
0e443c99 9332
9333 /*
7cca0d81 9334 * Transfer data!
9335 */
b9d7bcad 9336 if (ssh->ldisc)
9337 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 9338 if (ssh->mainchan)
9339 ssh->send_ok = 1;
7cca0d81 9340 while (1) {
e5574168 9341 crReturnV;
51470298 9342 s->try_send = FALSE;
ff3187f6 9343 if (pktin) {
2b7540a7 9344
51df0ab5 9345 /*
9346 * _All_ the connection-layer packets we expect to
9347 * receive are now handled by the dispatch table.
9348 * Anything that reaches here must be bogus.
9349 */
32874aea 9350
51df0ab5 9351 bombout(("Strange packet received: type %d", pktin->type));
9352 crStopV;
0ed48730 9353 } else if (ssh->mainchan) {
32874aea 9354 /*
9355 * We have spare data. Add it to the channel buffer.
9356 */
d8baa528 9357 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 9358 s->try_send = TRUE;
32874aea 9359 }
51470298 9360 if (s->try_send) {
32874aea 9361 int i;
9362 struct ssh_channel *c;
9363 /*
9364 * Try to send data on all channels if we can.
9365 */
1bfc7e93 9366 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
78280721 9367 ssh2_try_send_and_unthrottle(ssh, c);
7cca0d81 9368 }
e5574168 9369 }
9370
9371 crFinishV;
9372}
9373
9374/*
2e85c969 9375 * Handlers for SSH-2 messages that might arrive at any moment.
b09eaa88 9376 */
409bfa77 9377static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 9378{
9379 /* log reason code in disconnect message */
9380 char *buf, *msg;
60860bc3 9381 int reason, msglen;
b09eaa88 9382
9383 reason = ssh_pkt_getuint32(pktin);
9384 ssh_pkt_getstring(pktin, &msg, &msglen);
9385
9386 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9387 buf = dupprintf("Received disconnect message (%s)",
9388 ssh2_disconnect_reasons[reason]);
9389 } else {
9390 buf = dupprintf("Received disconnect message (unknown"
9391 " type %d)", reason);
9392 }
9393 logevent(buf);
9394 sfree(buf);
60860bc3 9395 buf = dupprintf("Disconnection message text: %.*s",
9396 msglen, msg);
b09eaa88 9397 logevent(buf);
60860bc3 9398 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
b09eaa88 9399 reason,
9400 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9401 ssh2_disconnect_reasons[reason] : "unknown",
60860bc3 9402 msglen, msg));
b09eaa88 9403 sfree(buf);
9404}
9405
409bfa77 9406static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 9407{
9408 /* log the debug message */
fb983202 9409 char *msg;
b09eaa88 9410 int msglen;
b09eaa88 9411
3ab79841 9412 /* XXX maybe we should actually take notice of the return value */
9413 ssh2_pkt_getbool(pktin);
b09eaa88 9414 ssh_pkt_getstring(pktin, &msg, &msglen);
9415
fb983202 9416 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 9417}
9418
bc074147 9419static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
9420{
9421 do_ssh2_transport(ssh, NULL, 0, pktin);
9422}
9423
9424/*
9425 * Called if we receive a packet that isn't allowed by the protocol.
9426 * This only applies to packets whose meaning PuTTY understands.
9427 * Entirely unknown packets are handled below.
9428 */
9429static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
9430{
9431 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
9432 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
9433 pktin->type));
9434 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
1418b055 9435 sfree(buf);
bc074147 9436}
9437
409bfa77 9438static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 9439{
9440 struct Packet *pktout;
9441 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9442 ssh2_pkt_adduint32(pktout, pktin->sequence);
9443 /*
9444 * UNIMPLEMENTED messages MUST appear in the same order as the
9445 * messages they respond to. Hence, never queue them.
9446 */
9447 ssh2_pkt_send_noqueue(ssh, pktout);
9448}
9449
9450/*
2e85c969 9451 * Handle the top-level SSH-2 protocol.
7cca0d81 9452 */
b09eaa88 9453static void ssh2_protocol_setup(Ssh ssh)
9454{
9455 int i;
9456
9457 /*
9458 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9459 */
9460 for (i = 0; i < 256; i++)
9461 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9462
9463 /*
bc074147 9464 * Initially, we only accept transport messages (and a few generic
9465 * ones). do_ssh2_authconn will add more when it starts.
9466 * Messages that are understood but not currently acceptable go to
9467 * ssh2_msg_unexpected.
b09eaa88 9468 */
bc074147 9469 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
9470 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
9471 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
9472 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
9473 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
9474 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
9475 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
9476 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9477 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9478 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
9479 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
9480 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
9481 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
9482 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
9483 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
9484 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
9485 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9486 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9487 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
9488 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
9489 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
9490 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
9491 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
9492 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
9493 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
9494 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
9495 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
9496 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
9497 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
9498 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
9499 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
9500 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
9501 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
b09eaa88 9502
9503 /*
bc074147 9504 * These messages have a special handler from the start.
b09eaa88 9505 */
9506 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
2e85c969 9507 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
b09eaa88 9508 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9509}
9510
9442dd57 9511static void ssh2_timer(void *ctx, long now)
9512{
9513 Ssh ssh = (Ssh)ctx;
9514
ecbb0000 9515 if (ssh->state == SSH_STATE_CLOSED)
9516 return;
9517
4a693cfc 9518 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9442dd57 9519 now - ssh->next_rekey >= 0) {
f382c87d 9520 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 9521 }
9522}
9523
1c1a7262 9524static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 9525 struct Packet *pktin)
7cca0d81 9526{
1c1a7262 9527 unsigned char *in = (unsigned char *)vin;
b09eaa88 9528 if (ssh->state == SSH_STATE_CLOSED)
9529 return;
9530
9442dd57 9531 if (pktin) {
9532 ssh->incoming_data_size += pktin->encrypted_len;
9533 if (!ssh->kex_in_progress &&
d57f70af 9534 ssh->max_data_size != 0 &&
9535 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9536 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 9537 }
9538
bc074147 9539 if (pktin)
b09eaa88 9540 ssh->packet_dispatch[pktin->type](ssh, pktin);
bc074147 9541 else if (!ssh->protocol_initial_phase_done)
9542 do_ssh2_transport(ssh, in, inlen, pktin);
9543 else
b09eaa88 9544 do_ssh2_authconn(ssh, in, inlen, pktin);
7cca0d81 9545}
9546
4a693cfc 9547static void ssh_cache_conf_values(Ssh ssh)
9548{
9549 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9550}
9551
7cca0d81 9552/*
8df7a775 9553 * Called to set up the connection.
374330e2 9554 *
9555 * Returns an error message, or NULL on success.
374330e2 9556 */
cbe2d68f 9557static const char *ssh_init(void *frontend_handle, void **backend_handle,
4a693cfc 9558 Conf *conf, char *host, int port, char **realhost,
9559 int nodelay, int keepalive)
32874aea 9560{
cbe2d68f 9561 const char *p;
51470298 9562 Ssh ssh;
9563
3d88e64d 9564 ssh = snew(struct ssh_tag);
4a693cfc 9565 ssh->conf = conf_copy(conf);
9566 ssh_cache_conf_values(ssh);
125105d1 9567 ssh->version = 0; /* when not ready yet */
51470298 9568 ssh->s = NULL;
9569 ssh->cipher = NULL;
371e569c 9570 ssh->v1_cipher_ctx = NULL;
0183b242 9571 ssh->crcda_ctx = NULL;
51470298 9572 ssh->cscipher = NULL;
371e569c 9573 ssh->cs_cipher_ctx = NULL;
51470298 9574 ssh->sccipher = NULL;
371e569c 9575 ssh->sc_cipher_ctx = NULL;
51470298 9576 ssh->csmac = NULL;
a8327734 9577 ssh->cs_mac_ctx = NULL;
51470298 9578 ssh->scmac = NULL;
e0e1a00d 9579 ssh->sc_mac_ctx = NULL;
51470298 9580 ssh->cscomp = NULL;
5366aed8 9581 ssh->cs_comp_ctx = NULL;
51470298 9582 ssh->sccomp = NULL;
5366aed8 9583 ssh->sc_comp_ctx = NULL;
51470298 9584 ssh->kex = NULL;
389aa499 9585 ssh->kex_ctx = NULL;
51470298 9586 ssh->hostkey = NULL;
9587 ssh->exitcode = -1;
ac934965 9588 ssh->close_expected = FALSE;
9e296bfa 9589 ssh->clean_exit = FALSE;
51470298 9590 ssh->state = SSH_STATE_PREPACKET;
9591 ssh->size_needed = FALSE;
9592 ssh->eof_needed = FALSE;
b9d7bcad 9593 ssh->ldisc = NULL;
a8327734 9594 ssh->logctx = NULL;
51470298 9595 ssh->deferred_send_data = NULL;
9596 ssh->deferred_len = 0;
9597 ssh->deferred_size = 0;
9598 ssh->fallback_cmd = 0;
acab36bc 9599 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9600 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8def70c3 9601 ssh->x11disp = NULL;
be738459 9602 ssh->v1_compressing = FALSE;
51470298 9603 ssh->v2_outgoing_sequence = 0;
9604 ssh->ssh1_rdpkt_crstate = 0;
9605 ssh->ssh2_rdpkt_crstate = 0;
51470298 9606 ssh->ssh_gotdata_crstate = 0;
b09eaa88 9607 ssh->do_ssh1_connection_crstate = 0;
51470298 9608 ssh->do_ssh_init_state = NULL;
9609 ssh->do_ssh1_login_state = NULL;
9610 ssh->do_ssh2_transport_state = NULL;
9611 ssh->do_ssh2_authconn_state = NULL;
4320baf7 9612 ssh->v_c = NULL;
9613 ssh->v_s = NULL;
6571dbfd 9614 ssh->mainchan = NULL;
968d2d92 9615 ssh->throttled_all = 0;
9616 ssh->v1_stdout_throttling = 0;
590f6a5f 9617 ssh->queue = NULL;
9618 ssh->queuelen = ssh->queuesize = 0;
9619 ssh->queueing = FALSE;
06fadff5 9620 ssh->qhead = ssh->qtail = NULL;
e13bba36 9621 ssh->deferred_rekey_reason = NULL;
3d9449a1 9622 bufchain_init(&ssh->queued_incoming_data);
9623 ssh->frozen = FALSE;
4a693cfc 9624 ssh->username = NULL;
bc06669b 9625 ssh->sent_console_eof = FALSE;
4a202fc6 9626 ssh->got_pty = FALSE;
51470298 9627
9628 *backend_handle = ssh;
32874aea 9629
8f203108 9630#ifdef MSCRYPTOAPI
32874aea 9631 if (crypto_startup() == 0)
8f203108 9632 return "Microsoft high encryption pack not installed!";
9633#endif
374330e2 9634
51470298 9635 ssh->frontend = frontend_handle;
4a693cfc 9636 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9637 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
887035a5 9638
fabd1805 9639 ssh->channels = NULL;
9640 ssh->rportfwds = NULL;
f47a5ffb 9641 ssh->portfwds = NULL;
fabd1805 9642
51470298 9643 ssh->send_ok = 0;
9644 ssh->editing = 0;
9645 ssh->echoing = 0;
ff68564b 9646 ssh->conn_throttle_count = 0;
51470298 9647 ssh->overall_bufsize = 0;
9648 ssh->fallback_cmd = 0;
8df7a775 9649
3648d4c5 9650 ssh->protocol = NULL;
9651
b09eaa88 9652 ssh->protocol_initial_phase_done = FALSE;
9653
39934deb 9654 ssh->pinger = NULL;
9655
9442dd57 9656 ssh->incoming_data_size = ssh->outgoing_data_size =
9657 ssh->deferred_data_size = 0L;
4a693cfc 9658 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9659 CONF_ssh_rekey_data));
9442dd57 9660 ssh->kex_in_progress = FALSE;
9661
1e00c92b 9662#ifndef NO_GSSAPI
9663 ssh->gsslibs = NULL;
9664#endif
9665
79bf227b 9666 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 9667 if (p != NULL)
9668 return p;
374330e2 9669
5d17ccfc 9670 random_ref();
9671
374330e2 9672 return NULL;
9673}
9674
fabd1805 9675static void ssh_free(void *handle)
9676{
9677 Ssh ssh = (Ssh) handle;
9678 struct ssh_channel *c;
9679 struct ssh_rportfwd *pf;
9680
9681 if (ssh->v1_cipher_ctx)
9682 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9683 if (ssh->cs_cipher_ctx)
9684 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9685 if (ssh->sc_cipher_ctx)
9686 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9687 if (ssh->cs_mac_ctx)
9688 ssh->csmac->free_context(ssh->cs_mac_ctx);
9689 if (ssh->sc_mac_ctx)
9690 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 9691 if (ssh->cs_comp_ctx) {
9692 if (ssh->cscomp)
9693 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9694 else
9695 zlib_compress_cleanup(ssh->cs_comp_ctx);
9696 }
9697 if (ssh->sc_comp_ctx) {
9698 if (ssh->sccomp)
9699 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9700 else
9701 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9702 }
fabd1805 9703 if (ssh->kex_ctx)
9704 dh_cleanup(ssh->kex_ctx);
9705 sfree(ssh->savedhost);
9706
590f6a5f 9707 while (ssh->queuelen-- > 0)
9708 ssh_free_packet(ssh->queue[ssh->queuelen]);
9709 sfree(ssh->queue);
9710
06fadff5 9711 while (ssh->qhead) {
9712 struct queued_handler *qh = ssh->qhead;
9713 ssh->qhead = qh->next;
9714 sfree(ssh->qhead);
9715 }
9716 ssh->qhead = ssh->qtail = NULL;
9717
fabd1805 9718 if (ssh->channels) {
9719 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9720 switch (c->type) {
9721 case CHAN_X11:
9722 if (c->u.x11.s != NULL)
9723 x11_close(c->u.x11.s);
9724 break;
9725 case CHAN_SOCKDATA:
409eca86 9726 case CHAN_SOCKDATA_DORMANT:
fabd1805 9727 if (c->u.pfd.s != NULL)
9728 pfd_close(c->u.pfd.s);
9729 break;
9730 }
3620f307 9731 if (ssh->version == 2) {
9732 struct outstanding_channel_request *ocr, *nocr;
9733 ocr = c->v.v2.chanreq_head;
9734 while (ocr) {
9735 ocr->handler(c, NULL, ocr->ctx);
9736 nocr = ocr->next;
9737 sfree(ocr);
9738 ocr = nocr;
9739 }
9740 bufchain_clear(&c->v.v2.outbuffer);
9741 }
fabd1805 9742 sfree(c);
9743 }
9744 freetree234(ssh->channels);
cdb52705 9745 ssh->channels = NULL;
fabd1805 9746 }
9747
9748 if (ssh->rportfwds) {
9749 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8aea57fd 9750 free_rportfwd(pf);
fabd1805 9751 freetree234(ssh->rportfwds);
cdb52705 9752 ssh->rportfwds = NULL;
fabd1805 9753 }
9754 sfree(ssh->deferred_send_data);
8def70c3 9755 if (ssh->x11disp)
9756 x11_free_display(ssh->x11disp);
fabd1805 9757 sfree(ssh->do_ssh_init_state);
9758 sfree(ssh->do_ssh1_login_state);
9759 sfree(ssh->do_ssh2_transport_state);
9760 sfree(ssh->do_ssh2_authconn_state);
4320baf7 9761 sfree(ssh->v_c);
9762 sfree(ssh->v_s);
42af6a67 9763 sfree(ssh->fullhostname);
679539d7 9764 if (ssh->crcda_ctx) {
9765 crcda_free_context(ssh->crcda_ctx);
9766 ssh->crcda_ctx = NULL;
9767 }
fabd1805 9768 if (ssh->s)
ac934965 9769 ssh_do_close(ssh, TRUE);
9442dd57 9770 expire_timer_context(ssh);
39934deb 9771 if (ssh->pinger)
9772 pinger_free(ssh->pinger);
3d9449a1 9773 bufchain_clear(&ssh->queued_incoming_data);
4a693cfc 9774 sfree(ssh->username);
9775 conf_free(ssh->conf);
1e00c92b 9776#ifndef NO_GSSAPI
9777 if (ssh->gsslibs)
9778 ssh_gss_cleanup(ssh->gsslibs);
9779#endif
ee50e8b6 9780 sfree(ssh);
5d17ccfc 9781
9782 random_unref();
fabd1805 9783}
9784
374330e2 9785/*
86916870 9786 * Reconfigure the SSH backend.
86916870 9787 */
4a693cfc 9788static void ssh_reconfig(void *handle, Conf *conf)
86916870 9789{
9790 Ssh ssh = (Ssh) handle;
e13bba36 9791 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 9792 unsigned long old_max_data_size;
4a693cfc 9793 int i, rekey_time;
e6c1536e 9794
4a693cfc 9795 pinger_reconfig(ssh->pinger, ssh->conf, conf);
3b6606c7 9796 if (ssh->portfwds)
4a693cfc 9797 ssh_setup_portfwd(ssh, conf);
e6c1536e 9798
4a693cfc 9799 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
9800 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
9801 rekey_time != 0) {
9802 long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
e6c1536e 9803 long now = GETTICKCOUNT();
9804
9805 if (new_next - now < 0) {
f382c87d 9806 rekeying = "timeout shortened";
e6c1536e 9807 } else {
9808 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9809 }
9810 }
9811
9812 old_max_data_size = ssh->max_data_size;
4a693cfc 9813 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9814 CONF_ssh_rekey_data));
e6c1536e 9815 if (old_max_data_size != ssh->max_data_size &&
9816 ssh->max_data_size != 0) {
9817 if (ssh->outgoing_data_size > ssh->max_data_size ||
9818 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9819 rekeying = "data limit lowered";
e6c1536e 9820 }
9821
4a693cfc 9822 if (conf_get_int(ssh->conf, CONF_compression) !=
9823 conf_get_int(conf, CONF_compression)) {
f382c87d 9824 rekeying = "compression setting changed";
e13bba36 9825 rekey_mandatory = TRUE;
9826 }
9827
4a693cfc 9828 for (i = 0; i < CIPHER_MAX; i++)
9829 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
9830 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
9831 rekeying = "cipher settings changed";
9832 rekey_mandatory = TRUE;
9833 }
9834 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
9835 conf_get_int(conf, CONF_ssh2_des_cbc)) {
f382c87d 9836 rekeying = "cipher settings changed";
e13bba36 9837 rekey_mandatory = TRUE;
e6c1536e 9838 }
9839
4a693cfc 9840 conf_free(ssh->conf);
9841 ssh->conf = conf_copy(conf);
9842 ssh_cache_conf_values(ssh);
e13bba36 9843
9844 if (rekeying) {
9845 if (!ssh->kex_in_progress) {
9846 do_ssh2_transport(ssh, rekeying, -1, NULL);
9847 } else if (rekey_mandatory) {
9848 ssh->deferred_rekey_reason = rekeying;
9849 }
9850 }
86916870 9851}
9852
9853/*
86dc445a 9854 * Called to send data down the SSH connection.
374330e2 9855 */
51470298 9856static int ssh_send(void *handle, char *buf, int len)
32874aea 9857{
51470298 9858 Ssh ssh = (Ssh) handle;
9859
9860 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9861 return 0;
374330e2 9862
d8baa528 9863 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 9864
51470298 9865 return ssh_sendbuffer(ssh);
5471d09a 9866}
9867
9868/*
9869 * Called to query the current amount of buffered stdin data.
9870 */
51470298 9871static int ssh_sendbuffer(void *handle)
5471d09a 9872{
51470298 9873 Ssh ssh = (Ssh) handle;
5471d09a 9874 int override_value;
9875
51470298 9876 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9877 return 0;
9878
9879 /*
9880 * If the SSH socket itself has backed up, add the total backup
9881 * size on that to any individual buffer on the stdin channel.
9882 */
9883 override_value = 0;
51470298 9884 if (ssh->throttled_all)
9885 override_value = ssh->overall_bufsize;
5471d09a 9886
51470298 9887 if (ssh->version == 1) {
5471d09a 9888 return override_value;
51470298 9889 } else if (ssh->version == 2) {
bc06669b 9890 if (!ssh->mainchan)
5471d09a 9891 return override_value;
9892 else
51470298 9893 return (override_value +
9894 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 9895 }
9896
9897 return 0;
374330e2 9898}
9899
9900/*
6e48c3fe 9901 * Called to set the size of the window from SSH's POV.
374330e2 9902 */
51470298 9903static void ssh_size(void *handle, int width, int height)
32874aea 9904{
51470298 9905 Ssh ssh = (Ssh) handle;
ff3187f6 9906 struct Packet *pktout;
51470298 9907
9908 ssh->term_width = width;
9909 ssh->term_height = height;
f278d6f8 9910
51470298 9911 switch (ssh->state) {
374330e2 9912 case SSH_STATE_BEFORE_SIZE:
3687d221 9913 case SSH_STATE_PREPACKET:
21248260 9914 case SSH_STATE_CLOSED:
374330e2 9915 break; /* do nothing */
9916 case SSH_STATE_INTERMED:
51470298 9917 ssh->size_needed = TRUE; /* buffer for later */
374330e2 9918 break;
9919 case SSH_STATE_SESSION:
4a693cfc 9920 if (!conf_get_int(ssh->conf, CONF_nopty)) {
51470298 9921 if (ssh->version == 1) {
9922 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
9923 PKT_INT, ssh->term_height,
9924 PKT_INT, ssh->term_width,
32874aea 9925 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 9926 } else if (ssh->mainchan) {
134f5ece 9927 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
9928 NULL, NULL);
ff3187f6 9929 ssh2_pkt_adduint32(pktout, ssh->term_width);
9930 ssh2_pkt_adduint32(pktout, ssh->term_height);
9931 ssh2_pkt_adduint32(pktout, 0);
9932 ssh2_pkt_adduint32(pktout, 0);
9933 ssh2_pkt_send(ssh, pktout);
32874aea 9934 }
9935 }
9936 break;
374330e2 9937 }
9938}
9939
9940/*
125105d1 9941 * Return a list of the special codes that make sense in this
9942 * protocol.
9943 */
9944static const struct telnet_special *ssh_get_specials(void *handle)
9945{
786ba75e 9946 static const struct telnet_special ssh1_ignore_special[] = {
9947 {"IGNORE message", TS_NOP}
9948 };
cf6ddb95 9949 static const struct telnet_special ssh2_ignore_special[] = {
62638676 9950 {"IGNORE message", TS_NOP},
cf6ddb95 9951 };
9952 static const struct telnet_special ssh2_rekey_special[] = {
9442dd57 9953 {"Repeat key exchange", TS_REKEY},
62638676 9954 };
9955 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 9956 {NULL, TS_SEP},
9957 {"Break", TS_BRK},
bccbeb71 9958 /* These are the signal names defined by RFC 4254.
6f2d0cde 9959 * They include all the ISO C signals, but are a subset of the POSIX
9960 * required signals. */
9961 {"SIGINT (Interrupt)", TS_SIGINT},
9962 {"SIGTERM (Terminate)", TS_SIGTERM},
9963 {"SIGKILL (Kill)", TS_SIGKILL},
9964 {"SIGQUIT (Quit)", TS_SIGQUIT},
9965 {"SIGHUP (Hangup)", TS_SIGHUP},
9966 {"More signals", TS_SUBMENU},
9967 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
9968 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
9969 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
9970 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
9971 {NULL, TS_EXITMENU}
62638676 9972 };
9973 static const struct telnet_special specials_end[] = {
6f2d0cde 9974 {NULL, TS_EXITMENU}
62638676 9975 };
786ba75e 9976 /* XXX review this length for any changes: */
cf6ddb95 9977 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
9978 lenof(ssh2_rekey_special) +
62638676 9979 lenof(ssh2_session_specials) +
9980 lenof(specials_end)];
125105d1 9981 Ssh ssh = (Ssh) handle;
62638676 9982 int i = 0;
9983#define ADD_SPECIALS(name) \
9984 do { \
9985 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9986 memcpy(&ssh_specials[i], name, sizeof name); \
9987 i += lenof(name); \
9988 } while(0)
125105d1 9989
9990 if (ssh->version == 1) {
62638676 9991 /* Don't bother offering IGNORE if we've decided the remote
9992 * won't cope with it, since we wouldn't bother sending it if
9993 * asked anyway. */
9994 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 9995 ADD_SPECIALS(ssh1_ignore_special);
125105d1 9996 } else if (ssh->version == 2) {
cf6ddb95 9997 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
9998 ADD_SPECIALS(ssh2_ignore_special);
9999 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
10000 ADD_SPECIALS(ssh2_rekey_special);
62638676 10001 if (ssh->mainchan)
10002 ADD_SPECIALS(ssh2_session_specials);
10003 } /* else we're not ready yet */
10004
10005 if (i) {
10006 ADD_SPECIALS(specials_end);
10007 return ssh_specials;
10008 } else {
125105d1 10009 return NULL;
62638676 10010 }
10011#undef ADD_SPECIALS
125105d1 10012}
10013
10014/*
86dc445a 10015 * Send special codes. TS_EOF is useful for `plink', so you
6abbf9e3 10016 * can send an EOF and collect resulting output (e.g. `plink
10017 * hostname sort').
374330e2 10018 */
51470298 10019static void ssh_special(void *handle, Telnet_Special code)
32874aea 10020{
51470298 10021 Ssh ssh = (Ssh) handle;
ff3187f6 10022 struct Packet *pktout;
51470298 10023
6abbf9e3 10024 if (code == TS_EOF) {
51470298 10025 if (ssh->state != SSH_STATE_SESSION) {
32874aea 10026 /*
10027 * Buffer the EOF in case we are pre-SESSION, so we can
10028 * send it as soon as we reach SESSION.
10029 */
10030 if (code == TS_EOF)
51470298 10031 ssh->eof_needed = TRUE;
32874aea 10032 return;
10033 }
51470298 10034 if (ssh->version == 1) {
10035 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 10036 } else if (ssh->mainchan) {
bc06669b 10037 sshfwd_write_eof(ssh->mainchan);
00a0b113 10038 ssh->send_ok = 0; /* now stop trying to read from stdin */
32874aea 10039 }
10040 logevent("Sent EOF message");
125105d1 10041 } else if (code == TS_PING || code == TS_NOP) {
51470298 10042 if (ssh->state == SSH_STATE_CLOSED
10043 || ssh->state == SSH_STATE_PREPACKET) return;
10044 if (ssh->version == 1) {
10045 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10046 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 10047 } else {
cf6ddb95 10048 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10049 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10050 ssh2_pkt_addstring_start(pktout);
10051 ssh2_pkt_send_noqueue(ssh, pktout);
10052 }
32874aea 10053 }
9442dd57 10054 } else if (code == TS_REKEY) {
10055 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 10056 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 10057 }
125105d1 10058 } else if (code == TS_BRK) {
10059 if (ssh->state == SSH_STATE_CLOSED
10060 || ssh->state == SSH_STATE_PREPACKET) return;
10061 if (ssh->version == 1) {
2e85c969 10062 logevent("Unable to send BREAK signal in SSH-1");
0ed48730 10063 } else if (ssh->mainchan) {
134f5ece 10064 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
ff3187f6 10065 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10066 ssh2_pkt_send(ssh, pktout);
125105d1 10067 }
6abbf9e3 10068 } else {
6f2d0cde 10069 /* Is is a POSIX signal? */
10070 char *signame = NULL;
10071 if (code == TS_SIGABRT) signame = "ABRT";
10072 if (code == TS_SIGALRM) signame = "ALRM";
10073 if (code == TS_SIGFPE) signame = "FPE";
10074 if (code == TS_SIGHUP) signame = "HUP";
10075 if (code == TS_SIGILL) signame = "ILL";
10076 if (code == TS_SIGINT) signame = "INT";
10077 if (code == TS_SIGKILL) signame = "KILL";
10078 if (code == TS_SIGPIPE) signame = "PIPE";
10079 if (code == TS_SIGQUIT) signame = "QUIT";
10080 if (code == TS_SIGSEGV) signame = "SEGV";
10081 if (code == TS_SIGTERM) signame = "TERM";
10082 if (code == TS_SIGUSR1) signame = "USR1";
10083 if (code == TS_SIGUSR2) signame = "USR2";
10084 /* The SSH-2 protocol does in principle support arbitrary named
10085 * signals, including signame@domain, but we don't support those. */
10086 if (signame) {
10087 /* It's a signal. */
10088 if (ssh->version == 2 && ssh->mainchan) {
134f5ece 10089 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
ff3187f6 10090 ssh2_pkt_addstring(pktout, signame);
10091 ssh2_pkt_send(ssh, pktout);
6f2d0cde 10092 logeventf(ssh, "Sent signal SIG%s", signame);
10093 }
10094 } else {
10095 /* Never heard of it. Do nothing */
10096 }
6abbf9e3 10097 }
374330e2 10098}
10099
51470298 10100void *new_sock_channel(void *handle, Socket s)
d74d141c 10101{
51470298 10102 Ssh ssh = (Ssh) handle;
d74d141c 10103 struct ssh_channel *c;
3d88e64d 10104 c = snew(struct ssh_channel);
d74d141c 10105
70c0cbe1 10106 c->ssh = ssh;
10107 ssh2_channel_init(c);
10108 c->halfopen = TRUE;
10109 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10110 c->u.pfd.s = s;
10111 add234(ssh->channels, c);
d74d141c 10112 return c;
10113}
10114
5471d09a 10115/*
10116 * This is called when stdout/stderr (the entity to which
10117 * from_backend sends data) manages to clear some backlog.
10118 */
ae9ae89f 10119static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 10120{
51470298 10121 Ssh ssh = (Ssh) handle;
ff68564b 10122 int buflimit;
10123
51470298 10124 if (ssh->version == 1) {
10125 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10126 ssh->v1_stdout_throttling = 0;
ff68564b 10127 ssh_throttle_conn(ssh, -1);
5471d09a 10128 }
10129 } else {
ff68564b 10130 if (ssh->mainchan) {
ab87bf1d 10131 ssh2_set_window(ssh->mainchan,
ff68564b 10132 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10133 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
4a693cfc 10134 if (conf_get_int(ssh->conf, CONF_ssh_simple))
ff68564b 10135 buflimit = 0;
10136 else
10137 buflimit = ssh->mainchan->v.v2.locmaxwin;
10138 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10139 ssh->mainchan->throttling_conn = 0;
10140 ssh_throttle_conn(ssh, -1);
10141 }
10142 }
5471d09a 10143 }
78e71de1 10144
10145 /*
10146 * Now process any SSH connection data that was stashed in our
10147 * queue while we were frozen.
10148 */
10149 ssh_process_queued_incoming_data(ssh);
5471d09a 10150}
10151
6b78788a 10152void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 10153{
10154 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 10155 Ssh ssh = c->ssh;
ff3187f6 10156 struct Packet *pktout;
d74d141c 10157
57356d63 10158 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 10159
51470298 10160 if (ssh->version == 1) {
10161 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 10162 PKT_INT, c->localid,
10163 PKT_STR, hostname,
10164 PKT_INT, port,
31fb1866 10165 /* PKT_STR, <org:orgport>, */
bc240b21 10166 PKT_END);
10167 } else {
ff3187f6 10168 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
10169 ssh2_pkt_addstring(pktout, "direct-tcpip");
10170 ssh2_pkt_adduint32(pktout, c->localid);
ff3187f6 10171 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 10172 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 10173 ssh2_pkt_addstring(pktout, hostname);
10174 ssh2_pkt_adduint32(pktout, port);
bc240b21 10175 /*
10176 * We make up values for the originator data; partly it's
10177 * too much hassle to keep track, and partly I'm not
10178 * convinced the server should be told details like that
10179 * about my local network configuration.
1f182589 10180 * The "originator IP address" is syntactically a numeric
10181 * IP address, and some servers (e.g., Tectia) get upset
10182 * if it doesn't match this syntax.
bc240b21 10183 */
1f182589 10184 ssh2_pkt_addstring(pktout, "0.0.0.0");
ff3187f6 10185 ssh2_pkt_adduint32(pktout, 0);
10186 ssh2_pkt_send(ssh, pktout);
bc240b21 10187 }
d74d141c 10188}
10189
6226c939 10190static int ssh_connected(void *handle)
32874aea 10191{
51470298 10192 Ssh ssh = (Ssh) handle;
6226c939 10193 return ssh->s != NULL;
32874aea 10194}
8ccc75b0 10195
51470298 10196static int ssh_sendok(void *handle)
32874aea 10197{
51470298 10198 Ssh ssh = (Ssh) handle;
10199 return ssh->send_ok;
32874aea 10200}
fb09bf1c 10201
51470298 10202static int ssh_ldisc(void *handle, int option)
32874aea 10203{
51470298 10204 Ssh ssh = (Ssh) handle;
32874aea 10205 if (option == LD_ECHO)
51470298 10206 return ssh->echoing;
32874aea 10207 if (option == LD_EDIT)
51470298 10208 return ssh->editing;
0965bee0 10209 return FALSE;
10210}
10211
b9d7bcad 10212static void ssh_provide_ldisc(void *handle, void *ldisc)
10213{
10214 Ssh ssh = (Ssh) handle;
10215 ssh->ldisc = ldisc;
10216}
10217
a8327734 10218static void ssh_provide_logctx(void *handle, void *logctx)
10219{
10220 Ssh ssh = (Ssh) handle;
10221 ssh->logctx = logctx;
10222}
10223
51470298 10224static int ssh_return_exitcode(void *handle)
10225{
10226 Ssh ssh = (Ssh) handle;
3bb2f322 10227 if (ssh->s != NULL)
10228 return -1;
10229 else
3c112d53 10230 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
51470298 10231}
10232
10233/*
f89c3294 10234 * cfg_info for SSH is the currently running version of the
10235 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10236 */
10237static int ssh_cfg_info(void *handle)
10238{
10239 Ssh ssh = (Ssh) handle;
10240 return ssh->version;
10241}
10242
10243/*
51470298 10244 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10245 * that fails. This variable is the means by which scp.c can reach
10246 * into the SSH code and find out which one it got.
10247 */
10248extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 10249{
51470298 10250 Ssh ssh = (Ssh) handle;
10251 return ssh->fallback_cmd;
d8d6c7e5 10252}
10253
374330e2 10254Backend ssh_backend = {
10255 ssh_init,
fabd1805 10256 ssh_free,
86916870 10257 ssh_reconfig,
374330e2 10258 ssh_send,
5471d09a 10259 ssh_sendbuffer,
374330e2 10260 ssh_size,
4017be6d 10261 ssh_special,
125105d1 10262 ssh_get_specials,
6226c939 10263 ssh_connected,
d8d6c7e5 10264 ssh_return_exitcode,
97db3be4 10265 ssh_sendok,
0965bee0 10266 ssh_ldisc,
b9d7bcad 10267 ssh_provide_ldisc,
a8327734 10268 ssh_provide_logctx,
5471d09a 10269 ssh_unthrottle,
f89c3294 10270 ssh_cfg_info,
9e164d82 10271 "ssh",
10272 PROT_SSH,
97db3be4 10273 22
bc240b21 10274};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator