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Tweak to SSH coroutine code: put line number in the coroutine state
[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; }
374330e2 442#define crReturn(z) \
443 do {\
51470298 444 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 445 } while (0)
446#define crReturnV \
447 do {\
51470298 448 *crLine=__LINE__; return; case __LINE__:;\
374330e2 449 } while (0)
51470298 450#define crStop(z) do{ *crLine = 0; return (z); }while(0)
451#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 452#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 453#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 454
51470298 455typedef struct ssh_tag *Ssh;
ff3187f6 456struct Packet;
457
dacd8872 458static struct Packet *ssh1_pkt_init(int pkt_type);
ff3187f6 459static struct Packet *ssh2_pkt_init(int pkt_type);
dacd8872 460static void ssh_pkt_ensure(struct Packet *, int length);
461static void ssh_pkt_adddata(struct Packet *, void *data, int len);
462static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
ff3187f6 463static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
dacd8872 464static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
465static void ssh_pkt_addstring_start(struct Packet *);
466static void ssh_pkt_addstring_str(struct Packet *, char *data);
467static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
468static void ssh_pkt_addstring(struct Packet *, char *data);
d8baa528 469static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
dacd8872 470static void ssh1_pkt_addmp(struct Packet *, Bignum b);
ff3187f6 471static void ssh2_pkt_addmp(struct Packet *, Bignum b);
472static int ssh2_pkt_construct(Ssh, struct Packet *);
473static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 474static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 475static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
476 struct Packet *pktin);
477static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
478 struct Packet *pktin);
997097db 479static void ssh2_channel_check_close(struct ssh_channel *c);
bc06669b 480static void ssh_channel_destroy(struct ssh_channel *c);
3d63ca2e 481
5471d09a 482/*
483 * Buffer management constants. There are several of these for
484 * various different purposes:
485 *
486 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
487 * on a local data stream before we throttle the whole SSH
2e85c969 488 * connection (in SSH-1 only). Throttling the whole connection is
5471d09a 489 * pretty drastic so we set this high in the hope it won't
490 * happen very often.
491 *
492 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
493 * on the SSH connection itself before we defensively throttle
494 * _all_ local data streams. This is pretty drastic too (though
2e85c969 495 * thankfully unlikely in SSH-2 since the window mechanism should
5471d09a 496 * ensure that the server never has any need to throttle its end
497 * of the connection), so we set this high as well.
498 *
2e85c969 499 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
5471d09a 500 * channels.
9b53e9b8 501 *
502 * - OUR_V2_BIGWIN is the window size we advertise for the only
3361b80a 503 * channel in a simple connection. It must be <= INT_MAX.
9916cc1e 504 *
505 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
506 * to the remote side. This actually has nothing to do with the
507 * size of the _packet_, but is instead a limit on the amount
508 * of data we're willing to receive in a single SSH2 channel
509 * data message.
510 *
511 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
512 * _packet_ we're prepared to cope with. It must be a multiple
513 * of the cipher block size, and must be at least 35000.
5471d09a 514 */
515
516#define SSH1_BUFFER_LIMIT 32768
517#define SSH_MAX_BACKLOG 32768
518#define OUR_V2_WINSIZE 16384
3361b80a 519#define OUR_V2_BIGWIN 0x7fffffff
954d5c5a 520#define OUR_V2_MAXPKT 0x4000UL
9916cc1e 521#define OUR_V2_PACKETLIMIT 0x9000UL
d74d141c 522
85cc02bb 523const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 524
8b2715b2 525const static struct ssh_mac *macs[] = {
6668a75e 526 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
32874aea 527};
8b2715b2 528const static struct ssh_mac *buggymacs[] = {
6668a75e 529 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
32874aea 530};
e5574168 531
5366aed8 532static void *ssh_comp_none_init(void)
533{
534 return NULL;
535}
536static void ssh_comp_none_cleanup(void *handle)
32874aea 537{
538}
5366aed8 539static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 540 unsigned char **outblock, int *outlen)
541{
542 return 0;
543}
5366aed8 544static int ssh_comp_none_disable(void *handle)
32874aea 545{
4ba9b64b 546 return 0;
547}
57476f6b 548const static struct ssh_compress ssh_comp_none = {
ab18ccff 549 "none", NULL,
5366aed8 550 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
551 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
552 ssh_comp_none_disable, NULL
e5574168 553};
4ba9b64b 554extern const struct ssh_compress ssh_zlib;
555const static struct ssh_compress *compressions[] = {
32874aea 556 &ssh_zlib, &ssh_comp_none
557};
374330e2 558
32874aea 559enum { /* channel types */
783415f8 560 CHAN_MAINSESSION,
561 CHAN_X11,
562 CHAN_AGENT,
bc240b21 563 CHAN_SOCKDATA,
c6b41791 564 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
565 /*
566 * CHAN_ZOMBIE is used to indicate a channel for which we've
567 * already destroyed the local data source: for instance, if a
568 * forwarded port experiences a socket error on the local side, we
569 * immediately destroy its local socket and turn the SSH channel
570 * into CHAN_ZOMBIE.
571 */
572 CHAN_ZOMBIE
783415f8 573};
574
dacbd0e8 575/*
0e443c99 576 * little structure to keep track of outstanding WINDOW_ADJUSTs
577 */
578struct winadj {
579 struct winadj *next;
580 unsigned size;
581};
582
583/*
dacbd0e8 584 * 2-3-4 tree storing channels.
585 */
586struct ssh_channel {
51470298 587 Ssh ssh; /* pointer back to main context */
d211621f 588 unsigned remoteid, localid;
dacbd0e8 589 int type;
64d6ff88 590 /* True if we opened this channel but server hasn't confirmed. */
591 int halfopen;
0357890f 592 /*
2e85c969 593 * In SSH-1, this value contains four bits:
0357890f 594 *
595 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
596 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
597 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
598 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
599 *
600 * A channel is completely finished with when all four bits are set.
bc06669b 601 *
602 * In SSH-2, the four bits mean:
603 *
604 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
605 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
606 * 4 We have received SSH2_MSG_CHANNEL_EOF.
607 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
608 *
609 * A channel is completely finished with when we have both sent
610 * and received CLOSE.
611 *
612 * The symbolic constants below use the SSH-2 terminology, which
613 * is a bit confusing in SSH-1, but we have to use _something_.
0357890f 614 */
bc06669b 615#define CLOSES_SENT_EOF 1
616#define CLOSES_SENT_CLOSE 2
617#define CLOSES_RCVD_EOF 4
618#define CLOSES_RCVD_CLOSE 8
dacbd0e8 619 int closes;
78280721 620
621 /*
bc06669b 622 * This flag indicates that an EOF is pending on the outgoing side
623 * of the channel: that is, wherever we're getting the data for
624 * this channel has sent us some data followed by EOF. We can't
625 * actually send the EOF until we've finished sending the data, so
626 * we set this flag instead to remind us to do so once our buffer
627 * is clear.
78280721 628 */
bc06669b 629 int pending_eof;
78280721 630
ff68564b 631 /*
632 * True if this channel is causing the underlying connection to be
633 * throttled.
634 */
635 int throttling_conn;
5471d09a 636 union {
5471d09a 637 struct ssh2_data_channel {
638 bufchain outbuffer;
639 unsigned remwindow, remmaxpkt;
467e064d 640 /* locwindow is signed so we can cope with excess data. */
9b53e9b8 641 int locwindow, locmaxwin;
0e443c99 642 /*
643 * remlocwin is the amount of local window that we think
644 * the remote end had available to it after it sent the
645 * last data packet or window adjust ack.
646 */
647 int remlocwin;
648 /*
649 * These store the list of window adjusts that haven't
650 * been acked.
651 */
652 struct winadj *winadj_head, *winadj_tail;
653 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
5471d09a 654 } v2;
655 } v;
dacbd0e8 656 union {
32874aea 657 struct ssh_agent_channel {
658 unsigned char *message;
659 unsigned char msglen[4];
a03c9f9c 660 unsigned lensofar, totallen;
32874aea 661 } a;
662 struct ssh_x11_channel {
663 Socket s;
664 } x11;
d74d141c 665 struct ssh_pfd_channel {
666 Socket s;
667 } pfd;
dacbd0e8 668 } u;
669};
57476f6b 670
d74d141c 671/*
2e85c969 672 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
673 * use this structure in different ways, reflecting SSH-2's
bc240b21 674 * altogether saner approach to port forwarding.
675 *
2e85c969 676 * In SSH-1, you arrange a remote forwarding by sending the server
bc240b21 677 * the remote port number, and the local destination host:port.
678 * When a connection comes in, the server sends you back that
679 * host:port pair, and you connect to it. This is a ready-made
680 * security hole if you're not on the ball: a malicious server
681 * could send you back _any_ host:port pair, so if you trustingly
682 * connect to the address it gives you then you've just opened the
683 * entire inside of your corporate network just by connecting
684 * through it to a dodgy SSH server. Hence, we must store a list of
685 * host:port pairs we _are_ trying to forward to, and reject a
686 * connection request from the server if it's not in the list.
687 *
2e85c969 688 * In SSH-2, each side of the connection minds its own business and
bc240b21 689 * doesn't send unnecessary information to the other. You arrange a
690 * remote forwarding by sending the server just the remote port
691 * number. When a connection comes in, the server tells you which
692 * of its ports was connected to; and _you_ have to remember what
693 * local host:port pair went with that port number.
694 *
2e85c969 695 * Hence, in SSH-1 this structure is indexed by destination
696 * host:port pair, whereas in SSH-2 it is indexed by source port.
d74d141c 697 */
fda2feb1 698struct ssh_portfwd; /* forward declaration */
699
d74d141c 700struct ssh_rportfwd {
bc240b21 701 unsigned sport, dport;
702 char dhost[256];
06fadff5 703 char *sportdesc;
fda2feb1 704 struct ssh_portfwd *pfrec;
d74d141c 705};
fda2feb1 706#define free_rportfwd(pf) ( \
707 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
708
709/*
710 * Separately to the rportfwd tree (which is for looking up port
711 * open requests from the server), a tree of _these_ structures is
712 * used to keep track of all the currently open port forwardings,
713 * so that we can reconfigure in mid-session if the user requests
714 * it.
715 */
716struct ssh_portfwd {
84328ddb 717 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 718 int type;
719 unsigned sport, dport;
720 char *saddr, *daddr;
3fe92132 721 char *sserv, *dserv;
fda2feb1 722 struct ssh_rportfwd *remote;
05581745 723 int addressfamily;
fda2feb1 724 void *local;
725};
726#define free_portfwd(pf) ( \
3fe92132 727 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
728 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 729
57476f6b 730struct Packet {
dacd8872 731 long length; /* length of `data' actually used */
732 long forcepad; /* SSH-2: force padding to at least this length */
733 int type; /* only used for incoming packets */
734 unsigned long sequence; /* SSH-2 incoming sequence number */
735 unsigned char *data; /* allocated storage */
736 unsigned char *body; /* offset of payload within `data' */
737 long savedpos; /* temporary index into `data' (for strings) */
738 long maxlen; /* amount of storage allocated for `data' */
739 long encrypted_len; /* for SSH-2 total-size counting */
ff3187f6 740
741 /*
742 * State associated with packet logging
743 */
744 int logmode;
745 int nblanks;
746 struct logblank_t *blanks;
57476f6b 747};
748
1c1a7262 749static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 750 struct Packet *pktin);
1c1a7262 751static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 752 struct Packet *pktin);
b09eaa88 753static void ssh1_protocol_setup(Ssh ssh);
754static void ssh2_protocol_setup(Ssh ssh);
51470298 755static void ssh_size(void *handle, int width, int height);
756static void ssh_special(void *handle, Telnet_Special);
5471d09a 757static int ssh2_try_send(struct ssh_channel *c);
51470298 758static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
759static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
9fca3f8c 760static void ssh2_set_window(struct ssh_channel *c, int newwin);
51470298 761static int ssh_sendbuffer(void *handle);
ac934965 762static int ssh_do_close(Ssh ssh, int notify_exit);
ff3187f6 763static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
764static int ssh2_pkt_getbool(struct Packet *pkt);
765static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 766static void ssh2_timer(void *ctx, long now);
1c1a7262 767static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
9442dd57 768 struct Packet *pktin);
57476f6b 769
51470298 770struct rdpkt1_state_tag {
57476f6b 771 long len, pad, biglen, to_read;
772 unsigned long realcrc, gotcrc;
773 unsigned char *p;
774 int i;
775 int chunk;
ff3187f6 776 struct Packet *pktin;
51470298 777};
57476f6b 778
51470298 779struct rdpkt2_state_tag {
960e736a 780 long len, pad, payload, packetlen, maclen;
781 int i;
782 int cipherblk;
783 unsigned long incoming_sequence;
ff3187f6 784 struct Packet *pktin;
51470298 785};
786
b09eaa88 787typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 788typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
789
790struct queued_handler;
791struct queued_handler {
792 int msg1, msg2;
793 chandler_fn_t handler;
794 void *ctx;
795 struct queued_handler *next;
796};
b09eaa88 797
51470298 798struct ssh_tag {
799 const struct plug_function_table *fn;
800 /* the above field _must_ be first in the structure */
801
4320baf7 802 char *v_c, *v_s;
b672f405 803 void *exhash;
51470298 804
805 Socket s;
806
b9d7bcad 807 void *ldisc;
a8327734 808 void *logctx;
b9d7bcad 809
51470298 810 unsigned char session_key[32];
811 int v1_compressing;
812 int v1_remote_protoflags;
813 int v1_local_protoflags;
814 int agentfwd_enabled;
815 int X11_fwd_enabled;
816 int remote_bugs;
817 const struct ssh_cipher *cipher;
371e569c 818 void *v1_cipher_ctx;
0183b242 819 void *crcda_ctx;
51470298 820 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 821 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 822 const struct ssh_mac *csmac, *scmac;
e0e1a00d 823 void *cs_mac_ctx, *sc_mac_ctx;
51470298 824 const struct ssh_compress *cscomp, *sccomp;
5366aed8 825 void *cs_comp_ctx, *sc_comp_ctx;
51470298 826 const struct ssh_kex *kex;
827 const struct ssh_signkey *hostkey;
754c0df9 828 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
b672f405 829 int v2_session_id_len;
27cd7fc2 830 void *kex_ctx;
51470298 831
832 char *savedhost;
833 int savedport;
834 int send_ok;
835 int echoing, editing;
836
837 void *frontend;
838
db219738 839 int ospeed, ispeed; /* temporaries */
51470298 840 int term_width, term_height;
841
842 tree234 *channels; /* indexed by local id */
843 struct ssh_channel *mainchan; /* primary session channel */
feb02b4e 844 int ncmode; /* is primary channel direct-tcpip? */
51470298 845 int exitcode;
ac934965 846 int close_expected;
9e296bfa 847 int clean_exit;
51470298 848
fda2feb1 849 tree234 *rportfwds, *portfwds;
51470298 850
851 enum {
852 SSH_STATE_PREPACKET,
853 SSH_STATE_BEFORE_SIZE,
854 SSH_STATE_INTERMED,
855 SSH_STATE_SESSION,
856 SSH_STATE_CLOSED
857 } state;
858
859 int size_needed, eof_needed;
bc06669b 860 int sent_console_eof;
4a202fc6 861 int got_pty; /* affects EOF behaviour on main channel */
51470298 862
590f6a5f 863 struct Packet **queue;
864 int queuelen, queuesize;
865 int queueing;
51470298 866 unsigned char *deferred_send_data;
867 int deferred_len, deferred_size;
868
869 /*
870 * Gross hack: pscp will try to start SFTP but fall back to
871 * scp1 if that fails. This variable is the means by which
872 * scp.c can reach into the SSH code and find out which one it
873 * got.
874 */
875 int fallback_cmd;
876
6bbce591 877 bufchain banner; /* accumulates banners during do_ssh2_authconn */
51470298 878
acab36bc 879 Pkt_KCtx pkt_kctx;
880 Pkt_ACtx pkt_actx;
51470298 881
8def70c3 882 struct X11Display *x11disp;
302121de 883
51470298 884 int version;
ff68564b 885 int conn_throttle_count;
51470298 886 int overall_bufsize;
887 int throttled_all;
888 int v1_stdout_throttling;
a8756193 889 unsigned long v2_outgoing_sequence;
51470298 890
891 int ssh1_rdpkt_crstate;
892 int ssh2_rdpkt_crstate;
51470298 893 int ssh_gotdata_crstate;
b09eaa88 894 int do_ssh1_connection_crstate;
51470298 895
896 void *do_ssh_init_state;
897 void *do_ssh1_login_state;
898 void *do_ssh2_transport_state;
899 void *do_ssh2_authconn_state;
900
901 struct rdpkt1_state_tag rdpkt1_state;
902 struct rdpkt2_state_tag rdpkt2_state;
903
2e85c969 904 /* SSH-1 and SSH-2 use this for different things, but both use it */
b09eaa88 905 int protocol_initial_phase_done;
906
1c1a7262 907 void (*protocol) (Ssh ssh, void *vin, int inlen,
ff3187f6 908 struct Packet *pkt);
909 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 910
911 /*
4a693cfc 912 * We maintain our own copy of a Conf structure here. That way,
913 * when we're passed a new one for reconfiguration, we can check
914 * the differences and potentially reconfigure port forwardings
915 * etc in mid-session.
86916870 916 */
4a693cfc 917 Conf *conf;
918
919 /*
920 * Values cached out of conf so as to avoid the tree234 lookup
921 * cost every time they're used.
922 */
923 int logomitdata;
924
925 /*
926 * Dynamically allocated username string created during SSH
927 * login. Stored in here rather than in the coroutine state so
928 * that it'll be reliably freed if we shut down the SSH session
929 * at some unexpected moment.
930 */
931 char *username;
839f10db 932
933 /*
3d9449a1 934 * Used to transfer data back from async callbacks.
839f10db 935 */
936 void *agent_response;
937 int agent_response_len;
3d9449a1 938 int user_response;
939
940 /*
941 * The SSH connection can be set as `frozen', meaning we are
942 * not currently accepting incoming data from the network. This
943 * is slightly more serious than setting the _socket_ as
944 * frozen, because we may already have had data passed to us
945 * from the network which we need to delay processing until
946 * after the freeze is lifted, so we also need a bufchain to
947 * store that data.
948 */
949 int frozen;
950 bufchain queued_incoming_data;
b09eaa88 951
952 /*
953 * Dispatch table for packet types that we may have to deal
954 * with at any time.
955 */
956 handler_fn_t packet_dispatch[256];
39934deb 957
958 /*
06fadff5 959 * Queues of one-off handler functions for success/failure
960 * indications from a request.
961 */
962 struct queued_handler *qhead, *qtail;
963
964 /*
39934deb 965 * This module deals with sending keepalives.
966 */
967 Pinger pinger;
9442dd57 968
969 /*
970 * Track incoming and outgoing data sizes and time, for
971 * size-based rekeys.
972 */
973 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 974 unsigned long max_data_size;
9442dd57 975 int kex_in_progress;
e6c1536e 976 long next_rekey, last_rekey;
e13bba36 977 char *deferred_rekey_reason; /* points to STATIC string; don't free */
42af6a67 978
979 /*
980 * Fully qualified host name, which we need if doing GSSAPI.
981 */
982 char *fullhostname;
1e00c92b 983
984#ifndef NO_GSSAPI
985 /*
986 * GSSAPI libraries for this session.
987 */
988 struct ssh_gss_liblist *gsslibs;
989#endif
51470298 990};
960e736a 991
382908ad 992#define logevent(s) logevent(ssh->frontend, s)
a8327734 993
994/* logevent, only printf-formatted. */
cbe2d68f 995static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 996{
997 va_list ap;
57356d63 998 char *buf;
a8327734 999
1000 va_start(ap, fmt);
57356d63 1001 buf = dupvprintf(fmt, ap);
a8327734 1002 va_end(ap);
57356d63 1003 logevent(buf);
57356d63 1004 sfree(buf);
a8327734 1005}
1006
6b5cf8b4 1007#define bombout(msg) \
1008 do { \
1009 char *text = dupprintf msg; \
ac934965 1010 ssh_do_close(ssh, FALSE); \
6b5cf8b4 1011 logevent(text); \
1012 connection_fatal(ssh->frontend, "%s", text); \
1013 sfree(text); \
1014 } while (0)
a8327734 1015
9a10ecf4 1016/* Functions to leave bits out of the SSH packet log file. */
1017
ff3187f6 1018static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1019{
4a693cfc 1020 if (conf_get_int(ssh->conf, CONF_logomitpass))
ff3187f6 1021 pkt->logmode = blanktype;
9a10ecf4 1022}
1023
ff3187f6 1024static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1025{
4a693cfc 1026 if (ssh->logomitdata)
ff3187f6 1027 pkt->logmode = blanktype;
9a10ecf4 1028}
1029
ff3187f6 1030static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 1031{
ff3187f6 1032 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 1033}
1034
4a693cfc 1035/* Helper function for common bits of parsing ttymodes. */
1036static void parse_ttymodes(Ssh ssh,
c6ccd5c2 1037 void (*do_mode)(void *data, char *mode, char *val),
1038 void *data)
1039{
4a693cfc 1040 char *key, *val;
1041
1042 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1043 val != NULL;
1044 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1045 /*
1046 * val[0] is either 'V', indicating that an explicit value
1047 * follows it, or 'A' indicating that we should pass the
1048 * value through from the local environment via get_ttymode.
1049 */
1050 if (val[0] == 'A')
1051 val = get_ttymode(ssh->frontend, key);
c6ccd5c2 1052 else
4a693cfc 1053 val++; /* skip the 'V' */
c6ccd5c2 1054 if (val)
4a693cfc 1055 do_mode(data, key, val);
c6ccd5c2 1056 }
1057}
1058
32874aea 1059static int ssh_channelcmp(void *av, void *bv)
1060{
1061 struct ssh_channel *a = (struct ssh_channel *) av;
1062 struct ssh_channel *b = (struct ssh_channel *) bv;
1063 if (a->localid < b->localid)
1064 return -1;
1065 if (a->localid > b->localid)
1066 return +1;
dacbd0e8 1067 return 0;
1068}
32874aea 1069static int ssh_channelfind(void *av, void *bv)
1070{
1071 unsigned *a = (unsigned *) av;
1072 struct ssh_channel *b = (struct ssh_channel *) bv;
1073 if (*a < b->localid)
1074 return -1;
1075 if (*a > b->localid)
1076 return +1;
dacbd0e8 1077 return 0;
1078}
1079
bc240b21 1080static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 1081{
1082 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1083 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1084 int i;
bc240b21 1085 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 1086 return i < 0 ? -1 : +1;
bc240b21 1087 if (a->dport > b->dport)
1088 return +1;
1089 if (a->dport < b->dport)
1090 return -1;
1091 return 0;
1092}
1093
1094static int ssh_rportcmp_ssh2(void *av, void *bv)
1095{
1096 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1097 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 1098
bc240b21 1099 if (a->sport > b->sport)
d74d141c 1100 return +1;
bc240b21 1101 if (a->sport < b->sport)
1102 return -1;
d74d141c 1103 return 0;
1104}
1105
fda2feb1 1106/*
1107 * Special form of strcmp which can cope with NULL inputs. NULL is
1108 * defined to sort before even the empty string.
1109 */
1110static int nullstrcmp(const char *a, const char *b)
1111{
1112 if (a == NULL && b == NULL)
1113 return 0;
1114 if (a == NULL)
1115 return -1;
1116 if (b == NULL)
1117 return +1;
1118 return strcmp(a, b);
1119}
1120
1121static int ssh_portcmp(void *av, void *bv)
1122{
1123 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1124 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1125 int i;
1126 if (a->type > b->type)
1127 return +1;
1128 if (a->type < b->type)
1129 return -1;
84328ddb 1130 if (a->addressfamily > b->addressfamily)
1131 return +1;
1132 if (a->addressfamily < b->addressfamily)
1133 return -1;
fda2feb1 1134 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1135 return i < 0 ? -1 : +1;
1136 if (a->sport > b->sport)
1137 return +1;
1138 if (a->sport < b->sport)
1139 return -1;
1140 if (a->type != 'D') {
1141 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1142 return i < 0 ? -1 : +1;
1143 if (a->dport > b->dport)
1144 return +1;
1145 if (a->dport < b->dport)
1146 return -1;
1147 }
1148 return 0;
1149}
1150
51470298 1151static int alloc_channel_id(Ssh ssh)
32874aea 1152{
260f3dec 1153 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1154 unsigned low, high, mid;
d2371c81 1155 int tsize;
1156 struct ssh_channel *c;
1157
1158 /*
1159 * First-fit allocation of channel numbers: always pick the
1160 * lowest unused one. To do this, binary-search using the
1161 * counted B-tree to find the largest channel ID which is in a
1162 * contiguous sequence from the beginning. (Precisely
1163 * everything in that sequence must have ID equal to its tree
1164 * index plus CHANNEL_NUMBER_OFFSET.)
1165 */
51470298 1166 tsize = count234(ssh->channels);
d2371c81 1167
32874aea 1168 low = -1;
1169 high = tsize;
d2371c81 1170 while (high - low > 1) {
1171 mid = (high + low) / 2;
51470298 1172 c = index234(ssh->channels, mid);
d2371c81 1173 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1174 low = mid; /* this one is fine */
1175 else
1176 high = mid; /* this one is past it */
1177 }
1178 /*
1179 * Now low points to either -1, or the tree index of the
1180 * largest ID in the initial sequence.
1181 */
1182 {
1183 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 1184 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 1185 }
1186 return low + 1 + CHANNEL_NUMBER_OFFSET;
1187}
1188
edd0cb8a 1189static void c_write_stderr(int trusted, const char *buf, int len)
1190{
1191 int i;
1192 for (i = 0; i < len; i++)
667deca9 1193 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
edd0cb8a 1194 fputc(buf[i], stderr);
1195}
1196
9fab77dc 1197static void c_write(Ssh ssh, const char *buf, int len)
32874aea 1198{
edd0cb8a 1199 if (flags & FLAG_STDERR)
1200 c_write_stderr(1, buf, len);
1201 else
1202 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 1203}
1204
9fab77dc 1205static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 1206{
edd0cb8a 1207 if (flags & FLAG_STDERR)
1208 c_write_stderr(0, buf, len);
1209 else
1210 from_backend_untrusted(ssh->frontend, buf, len);
a209e957 1211}
1212
9fab77dc 1213static void c_write_str(Ssh ssh, const char *buf)
32874aea 1214{
51470298 1215 c_write(ssh, buf, strlen(buf));
1408a877 1216}
1217
ff3187f6 1218static void ssh_free_packet(struct Packet *pkt)
1219{
1220 sfree(pkt->data);
1221 sfree(pkt);
1222}
1223static struct Packet *ssh_new_packet(void)
1224{
1225 struct Packet *pkt = snew(struct Packet);
1226
dacd8872 1227 pkt->body = pkt->data = NULL;
ff3187f6 1228 pkt->maxlen = 0;
1229 pkt->logmode = PKTLOG_EMIT;
1230 pkt->nblanks = 0;
1231 pkt->blanks = NULL;
1232
1233 return pkt;
1234}
1235
fb09bf1c 1236/*
1237 * Collect incoming data in the incoming packet buffer.
e5574168 1238 * Decipher and verify the packet when it is completely read.
1239 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 1240 * Update the *data and *datalen variables.
ff3187f6 1241 * Return a Packet structure when a packet is completed.
fb09bf1c 1242 */
ff3187f6 1243static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 1244{
51470298 1245 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 1246
51470298 1247 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 1248
ff3187f6 1249 st->pktin = ssh_new_packet();
1250
1251 st->pktin->type = 0;
1252 st->pktin->length = 0;
374330e2 1253
57476f6b 1254 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 1255 while ((*datalen) == 0)
ff3187f6 1256 crReturn(NULL);
57476f6b 1257 st->len = (st->len << 8) + **data;
fb09bf1c 1258 (*data)++, (*datalen)--;
1259 }
374330e2 1260
57476f6b 1261 st->pad = 8 - (st->len % 8);
1262 st->biglen = st->len + st->pad;
ff3187f6 1263 st->pktin->length = st->len - 5;
fb09bf1c 1264
ae0500e5 1265 if (st->biglen < 0) {
1266 bombout(("Extremely large packet length from server suggests"
1267 " data stream corruption"));
ff3187f6 1268 ssh_free_packet(st->pktin);
1269 crStop(NULL);
ae0500e5 1270 }
1271
ff3187f6 1272 st->pktin->maxlen = st->biglen;
1273 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1274
57476f6b 1275 st->to_read = st->biglen;
ff3187f6 1276 st->p = st->pktin->data;
57476f6b 1277 while (st->to_read > 0) {
32874aea 1278 st->chunk = st->to_read;
fb09bf1c 1279 while ((*datalen) == 0)
ff3187f6 1280 crReturn(NULL);
57476f6b 1281 if (st->chunk > (*datalen))
1282 st->chunk = (*datalen);
1283 memcpy(st->p, *data, st->chunk);
1284 *data += st->chunk;
1285 *datalen -= st->chunk;
1286 st->p += st->chunk;
1287 st->to_read -= st->chunk;
fb09bf1c 1288 }
374330e2 1289
ff3187f6 1290 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1291 st->biglen, NULL)) {
6b5cf8b4 1292 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1293 ssh_free_packet(st->pktin);
1294 crStop(NULL);
9a3a93a5 1295 }
1296
51470298 1297 if (ssh->cipher)
ff3187f6 1298 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1299
ff3187f6 1300 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1301 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1302 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1303 bombout(("Incorrect CRC received on packet"));
ff3187f6 1304 ssh_free_packet(st->pktin);
1305 crStop(NULL);
fb09bf1c 1306 }
572f871e 1307
ff3187f6 1308 st->pktin->body = st->pktin->data + st->pad + 1;
1309 st->pktin->savedpos = 0;
4ba9b64b 1310
51470298 1311 if (ssh->v1_compressing) {
4ba9b64b 1312 unsigned char *decompblk;
1313 int decomplen;
36b8d9bb 1314 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1315 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1316 &decompblk, &decomplen)) {
1317 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1318 ssh_free_packet(st->pktin);
1319 crStop(NULL);
36b8d9bb 1320 }
4ba9b64b 1321
ff3187f6 1322 if (st->pktin->maxlen < st->pad + decomplen) {
1323 st->pktin->maxlen = st->pad + decomplen;
1324 st->pktin->data = sresize(st->pktin->data,
1325 st->pktin->maxlen + APIEXTRA,
3d88e64d 1326 unsigned char);
ff3187f6 1327 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1328 }
1329
ff3187f6 1330 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1331 sfree(decompblk);
ff3187f6 1332 st->pktin->length = decomplen - 1;
4ba9b64b 1333 }
1334
ff3187f6 1335 st->pktin->type = st->pktin->body[-1];
00db133f 1336
9a10ecf4 1337 /*
1338 * Log incoming packet, possibly omitting sensitive fields.
1339 */
1340 if (ssh->logctx) {
1341 int nblanks = 0;
1342 struct logblank_t blank;
4a693cfc 1343 if (ssh->logomitdata) {
9a10ecf4 1344 int do_blank = FALSE, blank_prefix = 0;
1345 /* "Session data" packets - omit the data field */
ff3187f6 1346 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1347 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1348 do_blank = TRUE; blank_prefix = 4;
a2724fba 1349 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1350 do_blank = TRUE; blank_prefix = 8;
9a10ecf4 1351 }
1352 if (do_blank) {
1353 blank.offset = blank_prefix;
ff3187f6 1354 blank.len = st->pktin->length;
9a10ecf4 1355 blank.type = PKTLOG_OMIT;
1356 nblanks = 1;
1357 }
1358 }
a8327734 1359 log_packet(ssh->logctx,
ff3187f6 1360 PKT_INCOMING, st->pktin->type,
1361 ssh1_pkt_type(st->pktin->type),
1362 st->pktin->body, st->pktin->length,
0d13bfcd 1363 nblanks, &blank, NULL);
9a10ecf4 1364 }
00db133f 1365
ff3187f6 1366 crFinish(st->pktin);
fb09bf1c 1367}
1368
ff3187f6 1369static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1370{
51470298 1371 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1372
51470298 1373 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1374
ff3187f6 1375 st->pktin = ssh_new_packet();
1376
1377 st->pktin->type = 0;
1378 st->pktin->length = 0;
51470298 1379 if (ssh->sccipher)
1380 st->cipherblk = ssh->sccipher->blksize;
e5574168 1381 else
32874aea 1382 st->cipherblk = 8;
960e736a 1383 if (st->cipherblk < 8)
32874aea 1384 st->cipherblk = 8;
9916cc1e 1385 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
960e736a 1386
9916cc1e 1387 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1388 ssh->scmac) {
1389 /*
1390 * When dealing with a CBC-mode cipher, we want to avoid the
1391 * possibility of an attacker's tweaking the ciphertext stream
1392 * so as to cause us to feed the same block to the block
1393 * cipher more than once and thus leak information
1394 * (VU#958563). The way we do this is not to take any
1395 * decisions on the basis of anything we've decrypted until
1396 * we've verified it with a MAC. That includes the packet
1397 * length, so we just read data and check the MAC repeatedly,
1398 * and when the MAC passes, see if the length we've got is
1399 * plausible.
1400 */
1401
1402 /* May as well allocate the whole lot now. */
1403 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1404 unsigned char);
1405
1406 /* Read an amount corresponding to the MAC. */
1407 for (st->i = 0; st->i < st->maclen; st->i++) {
1408 while ((*datalen) == 0)
1409 crReturn(NULL);
1410 st->pktin->data[st->i] = *(*data)++;
1411 (*datalen)--;
1412 }
e5574168 1413
9916cc1e 1414 st->packetlen = 0;
1415 {
1416 unsigned char seq[4];
1417 ssh->scmac->start(ssh->sc_mac_ctx);
1418 PUT_32BIT(seq, st->incoming_sequence);
1419 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1420 }
4252c9cc 1421
9916cc1e 1422 for (;;) { /* Once around this loop per cipher block. */
1423 /* Read another cipher-block's worth, and tack it onto the end. */
1424 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1425 while ((*datalen) == 0)
1426 crReturn(NULL);
1427 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1428 (*datalen)--;
1429 }
1430 /* Decrypt one more block (a little further back in the stream). */
1431 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1432 st->pktin->data + st->packetlen,
1433 st->cipherblk);
1434 /* Feed that block to the MAC. */
1435 ssh->scmac->bytes(ssh->sc_mac_ctx,
1436 st->pktin->data + st->packetlen, st->cipherblk);
1437 st->packetlen += st->cipherblk;
1438 /* See if that gives us a valid packet. */
1439 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1440 st->pktin->data + st->packetlen) &&
1441 (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen)
1442 break;
1443 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1444 bombout(("No valid incoming packet found"));
1445 ssh_free_packet(st->pktin);
1446 crStop(NULL);
1447 }
1448 }
1449 st->pktin->maxlen = st->packetlen + st->maclen;
1450 st->pktin->data = sresize(st->pktin->data,
1451 st->pktin->maxlen + APIEXTRA,
1452 unsigned char);
1453 } else {
1454 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1455
1456 /*
1457 * Acquire and decrypt the first block of the packet. This will
1458 * contain the length and padding details.
1459 */
1460 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1461 while ((*datalen) == 0)
1462 crReturn(NULL);
1463 st->pktin->data[st->i] = *(*data)++;
1464 (*datalen)--;
1465 }
e5574168 1466
9916cc1e 1467 if (ssh->sccipher)
1468 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1469 st->pktin->data, st->cipherblk);
1470
1471 /*
1472 * Now get the length figure.
1473 */
1474 st->len = GET_32BIT(st->pktin->data);
1475
1476 /*
1477 * _Completely_ silly lengths should be stomped on before they
1478 * do us any more damage.
1479 */
1480 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1481 (st->len + 4) % st->cipherblk != 0) {
1482 bombout(("Incoming packet was garbled on decryption"));
1483 ssh_free_packet(st->pktin);
1484 crStop(NULL);
1485 }
e5574168 1486
9916cc1e 1487 /*
1488 * So now we can work out the total packet length.
1489 */
1490 st->packetlen = st->len + 4;
1491
1492 /*
1493 * Allocate memory for the rest of the packet.
1494 */
1495 st->pktin->maxlen = st->packetlen + st->maclen;
1496 st->pktin->data = sresize(st->pktin->data,
1497 st->pktin->maxlen + APIEXTRA,
1498 unsigned char);
1499
1500 /*
1501 * Read and decrypt the remainder of the packet.
1502 */
1503 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1504 st->i++) {
1505 while ((*datalen) == 0)
1506 crReturn(NULL);
1507 st->pktin->data[st->i] = *(*data)++;
1508 (*datalen)--;
1509 }
1510 /* Decrypt everything _except_ the MAC. */
1511 if (ssh->sccipher)
1512 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1513 st->pktin->data + st->cipherblk,
1514 st->packetlen - st->cipherblk);
1515
1516 /*
1517 * Check the MAC.
1518 */
1519 if (ssh->scmac
1520 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1521 st->len + 4, st->incoming_sequence)) {
1522 bombout(("Incorrect MAC received on packet"));
1523 ssh_free_packet(st->pktin);
1524 crStop(NULL);
1525 }
1526 }
1527 /* Get and sanity-check the amount of random padding. */
1528 st->pad = st->pktin->data[4];
1529 if (st->pad < 4 || st->len - st->pad < 1) {
1530 bombout(("Invalid padding length on received packet"));
ff3187f6 1531 ssh_free_packet(st->pktin);
1532 crStop(NULL);
717dc483 1533 }
717dc483 1534 /*
e5574168 1535 * This enables us to deduce the payload length.
1536 */
960e736a 1537 st->payload = st->len - st->pad - 1;
e5574168 1538
ff3187f6 1539 st->pktin->length = st->payload + 5;
9442dd57 1540 st->pktin->encrypted_len = st->packetlen;
1541
b09eaa88 1542 st->pktin->sequence = st->incoming_sequence++;
e5574168 1543
4ba9b64b 1544 /*
1545 * Decompress packet payload.
1546 */
1547 {
1548 unsigned char *newpayload;
1549 int newlen;
51470298 1550 if (ssh->sccomp &&
5366aed8 1551 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1552 st->pktin->data + 5, st->pktin->length - 5,
51470298 1553 &newpayload, &newlen)) {
ff3187f6 1554 if (st->pktin->maxlen < newlen + 5) {
1555 st->pktin->maxlen = newlen + 5;
1556 st->pktin->data = sresize(st->pktin->data,
1557 st->pktin->maxlen + APIEXTRA,
3d88e64d 1558 unsigned char);
4ba9b64b 1559 }
ff3187f6 1560 st->pktin->length = 5 + newlen;
1561 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1562 sfree(newpayload);
4ba9b64b 1563 }
1564 }
1565
ff3187f6 1566 st->pktin->savedpos = 6;
1567 st->pktin->body = st->pktin->data;
1568 st->pktin->type = st->pktin->data[5];
e5574168 1569
9a10ecf4 1570 /*
1571 * Log incoming packet, possibly omitting sensitive fields.
1572 */
1573 if (ssh->logctx) {
1574 int nblanks = 0;
1575 struct logblank_t blank;
4a693cfc 1576 if (ssh->logomitdata) {
9a10ecf4 1577 int do_blank = FALSE, blank_prefix = 0;
1578 /* "Session data" packets - omit the data field */
ff3187f6 1579 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1580 do_blank = TRUE; blank_prefix = 8;
a2724fba 1581 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1582 do_blank = TRUE; blank_prefix = 12;
9a10ecf4 1583 }
1584 if (do_blank) {
1585 blank.offset = blank_prefix;
ff3187f6 1586 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1587 blank.type = PKTLOG_OMIT;
1588 nblanks = 1;
1589 }
1590 }
ff3187f6 1591 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
acab36bc 1592 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1593 st->pktin->type),
ff3187f6 1594 st->pktin->data+6, st->pktin->length-6,
0d13bfcd 1595 nblanks, &blank, &st->pktin->sequence);
9a10ecf4 1596 }
00db133f 1597
ff3187f6 1598 crFinish(st->pktin);
e5574168 1599}
1600
dacd8872 1601static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
32874aea 1602{
dacd8872 1603 int pad, biglen, i, pktoffs;
374330e2 1604 unsigned long crc;
fd7a4aad 1605#ifdef __SC__
1606 /*
1607 * XXX various versions of SC (including 8.8.4) screw up the
1608 * register allocation in this function and use the same register
1609 * (D6) for len and as a temporary, with predictable results. The
1610 * following sledgehammer prevents this.
1611 */
1612 volatile
1613#endif
1614 int len;
374330e2 1615
a8327734 1616 if (ssh->logctx)
dacd8872 1617 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1618 ssh1_pkt_type(pkt->data[12]),
1619 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1620 pkt->nblanks, pkt->blanks, NULL);
ff3187f6 1621 sfree(pkt->blanks); pkt->blanks = NULL;
1622 pkt->nblanks = 0;
00db133f 1623
51470298 1624 if (ssh->v1_compressing) {
4ba9b64b 1625 unsigned char *compblk;
1626 int complen;
5366aed8 1627 zlib_compress_block(ssh->cs_comp_ctx,
dacd8872 1628 pkt->data + 12, pkt->length - 12,
4ba9b64b 1629 &compblk, &complen);
48406e6b 1630 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
dacd8872 1631 memcpy(pkt->data + 12, compblk, complen);
dcbde236 1632 sfree(compblk);
dacd8872 1633 pkt->length = complen + 12;
4ba9b64b 1634 }
1635
dacd8872 1636 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1637 pkt->length += 4;
1638 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
32874aea 1639 pad = 8 - (len % 8);
dacd8872 1640 pktoffs = 8 - pad;
1641 biglen = len + pad; /* len(padding+type+data+CRC) */
374330e2 1642
dacd8872 1643 for (i = pktoffs; i < 4+8; i++)
1644 pkt->data[i] = random_byte();
1645 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1646 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1647 PUT_32BIT(pkt->data + pktoffs, len);
374330e2 1648
51470298 1649 if (ssh->cipher)
dacd8872 1650 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1651 pkt->data + pktoffs + 4, biglen);
374330e2 1652
dacd8872 1653 if (offset_p) *offset_p = pktoffs;
1654 return biglen + 4; /* len(length+padding+type+data+CRC) */
39065bed 1655}
1656
bf8a49a1 1657static int s_write(Ssh ssh, void *data, int len)
1658{
ff05dfef 1659 if (ssh->logctx)
0d13bfcd 1660 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1661 0, NULL, NULL);
bf8a49a1 1662 return sk_write(ssh->s, (char *)data, len);
1663}
1664
ff3187f6 1665static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1666{
dacd8872 1667 int len, backlog, offset;
1668 len = s_wrpkt_prepare(ssh, pkt, &offset);
bf8a49a1 1669 backlog = s_write(ssh, pkt->data + offset, len);
5471d09a 1670 if (backlog > SSH_MAX_BACKLOG)
51470298 1671 ssh_throttle_all(ssh, 1, backlog);
dacd8872 1672 ssh_free_packet(pkt);
39065bed 1673}
1674
ff3187f6 1675static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1676{
dacd8872 1677 int len, offset;
1678 len = s_wrpkt_prepare(ssh, pkt, &offset);
51470298 1679 if (ssh->deferred_len + len > ssh->deferred_size) {
1680 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1681 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1682 ssh->deferred_size,
1683 unsigned char);
39065bed 1684 }
dacd8872 1685 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1686 pkt->data + offset, len);
51470298 1687 ssh->deferred_len += len;
dacd8872 1688 ssh_free_packet(pkt);
374330e2 1689}
1690
fb09bf1c 1691/*
dacd8872 1692 * Construct a SSH-1 packet with the specified contents.
1693 * (This all-at-once interface used to be the only one, but now SSH-1
1694 * packets can also be constructed incrementally.)
fb09bf1c 1695 */
dacd8872 1696static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
fb09bf1c 1697{
dacd8872 1698 int argtype;
7cca0d81 1699 Bignum bn;
ff3187f6 1700 struct Packet *pkt;
fb09bf1c 1701
dacd8872 1702 pkt = ssh1_pkt_init(pkttype);
fb09bf1c 1703
dacd8872 1704 while ((argtype = va_arg(ap, int)) != PKT_END) {
1705 unsigned char *argp, argchar;
8a9977e5 1706 char *sargp;
dacd8872 1707 unsigned long argint;
1708 int arglen;
fb09bf1c 1709 switch (argtype) {
9a10ecf4 1710 /* Actual fields in the packet */
fb09bf1c 1711 case PKT_INT:
dacd8872 1712 argint = va_arg(ap, int);
1713 ssh_pkt_adduint32(pkt, argint);
fb09bf1c 1714 break;
1715 case PKT_CHAR:
dacd8872 1716 argchar = (unsigned char) va_arg(ap, int);
1717 ssh_pkt_addbyte(pkt, argchar);
fb09bf1c 1718 break;
1719 case PKT_DATA:
dacd8872 1720 argp = va_arg(ap, unsigned char *);
1721 arglen = va_arg(ap, int);
1722 ssh_pkt_adddata(pkt, argp, arglen);
fb09bf1c 1723 break;
1724 case PKT_STR:
8a9977e5 1725 sargp = va_arg(ap, char *);
1726 ssh_pkt_addstring(pkt, sargp);
fb09bf1c 1727 break;
7cca0d81 1728 case PKT_BIGNUM:
dacd8872 1729 bn = va_arg(ap, Bignum);
1730 ssh1_pkt_addmp(pkt, bn);
9a10ecf4 1731 break;
1732 /* Tokens for modifications to packet logging */
1733 case PKTT_PASSWORD:
ff3187f6 1734 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1735 break;
1736 case PKTT_DATA:
ff3187f6 1737 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1738 break;
9a10ecf4 1739 case PKTT_OTHER:
ff3187f6 1740 end_log_omission(ssh, pkt);
9a10ecf4 1741 break;
1742 }
fb09bf1c 1743 }
ff3187f6 1744
1745 return pkt;
39065bed 1746}
fb09bf1c 1747
51470298 1748static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1749{
ff3187f6 1750 struct Packet *pkt;
dacd8872 1751 va_list ap;
1752 va_start(ap, pkttype);
1753 pkt = construct_packet(ssh, pkttype, ap);
1754 va_end(ap);
ff3187f6 1755 s_wrpkt(ssh, pkt);
fb09bf1c 1756}
1757
51470298 1758static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1759{
ff3187f6 1760 struct Packet *pkt;
dacd8872 1761 va_list ap;
1762 va_start(ap, pkttype);
1763 pkt = construct_packet(ssh, pkttype, ap);
1764 va_end(ap);
ff3187f6 1765 s_wrpkt_defer(ssh, pkt);
39065bed 1766}
1767
32874aea 1768static int ssh_versioncmp(char *a, char *b)
1769{
9697bfd2 1770 char *ae, *be;
1771 unsigned long av, bv;
1772
43aa02a7 1773 av = strtoul(a, &ae, 10);
1774 bv = strtoul(b, &be, 10);
32874aea 1775 if (av != bv)
1776 return (av < bv ? -1 : +1);
1777 if (*ae == '.')
1778 ae++;
1779 if (*be == '.')
1780 be++;
43aa02a7 1781 av = strtoul(ae, &ae, 10);
1782 bv = strtoul(be, &be, 10);
32874aea 1783 if (av != bv)
1784 return (av < bv ? -1 : +1);
9697bfd2 1785 return 0;
1786}
1787
e5574168 1788/*
a92dd380 1789 * Utility routines for putting an SSH-protocol `string' and
b672f405 1790 * `uint32' into a hash state.
e5574168 1791 */
b672f405 1792static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
32874aea 1793{
e5574168 1794 unsigned char lenblk[4];
e5574168 1795 PUT_32BIT(lenblk, len);
b672f405 1796 h->bytes(s, lenblk, 4);
1797 h->bytes(s, str, len);
e5574168 1798}
1799
b672f405 1800static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
32874aea 1801{
a92dd380 1802 unsigned char intblk[4];
1803 PUT_32BIT(intblk, i);
b672f405 1804 h->bytes(s, intblk, 4);
a92dd380 1805}
1806
7cca0d81 1807/*
dacd8872 1808 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
7cca0d81 1809 */
dacd8872 1810static void ssh_pkt_ensure(struct Packet *pkt, int length)
32874aea 1811{
ff3187f6 1812 if (pkt->maxlen < length) {
dacd8872 1813 unsigned char *body = pkt->body;
3d71de0b 1814 int offset = body ? body - pkt->data : 0;
ff3187f6 1815 pkt->maxlen = length + 256;
1816 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
dacd8872 1817 if (body) pkt->body = pkt->data + offset;
7cca0d81 1818 }
783415f8 1819}
dacd8872 1820static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1821{
ff3187f6 1822 if (pkt->logmode != PKTLOG_EMIT) {
1823 pkt->nblanks++;
1824 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
dacd8872 1825 assert(pkt->body);
1826 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1827 (pkt->body - pkt->data);
ff3187f6 1828 pkt->blanks[pkt->nblanks-1].len = len;
1829 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1830 }
1831 pkt->length += len;
dacd8872 1832 ssh_pkt_ensure(pkt, pkt->length);
ff3187f6 1833 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1834}
dacd8872 1835static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1836{
dacd8872 1837 ssh_pkt_adddata(pkt, &byte, 1);
7cca0d81 1838}
ff3187f6 1839static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1840{
dacd8872 1841 ssh_pkt_adddata(pkt, &value, 1);
7cca0d81 1842}
dacd8872 1843static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1844{
7cca0d81 1845 unsigned char x[4];
1846 PUT_32BIT(x, value);
dacd8872 1847 ssh_pkt_adddata(pkt, x, 4);
7cca0d81 1848}
dacd8872 1849static void ssh_pkt_addstring_start(struct Packet *pkt)
32874aea 1850{
dacd8872 1851 ssh_pkt_adduint32(pkt, 0);
ff3187f6 1852 pkt->savedpos = pkt->length;
7cca0d81 1853}
dacd8872 1854static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1855{
dacd8872 1856 ssh_pkt_adddata(pkt, data, strlen(data));
ff3187f6 1857 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1858}
dacd8872 1859static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1860{
dacd8872 1861 ssh_pkt_adddata(pkt, data, len);
ff3187f6 1862 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1863}
dacd8872 1864static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1865{
1866 ssh_pkt_addstring_start(pkt);
1867 ssh_pkt_addstring_str(pkt, data);
1868}
1869static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1870{
dacd8872 1871 int len = ssh1_bignum_length(b);
8a9977e5 1872 unsigned char *data = snewn(len, unsigned char);
dacd8872 1873 (void) ssh1_write_bignum(data, b);
1874 ssh_pkt_adddata(pkt, data, len);
1875 sfree(data);
7cca0d81 1876}
d8baa528 1877static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1878{
7cca0d81 1879 unsigned char *p;
32874aea 1880 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1881 p = snewn(n + 1, unsigned char);
7cca0d81 1882 p[0] = 0;
3709bfe9 1883 for (i = 1; i <= n; i++)
32874aea 1884 p[i] = bignum_byte(b, n - i);
7cca0d81 1885 i = 0;
32874aea 1886 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1887 i++;
1888 memmove(p, p + i, n + 1 - i);
1889 *len = n + 1 - i;
7cca0d81 1890 return p;
1891}
ff3187f6 1892static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1893{
7cca0d81 1894 unsigned char *p;
1895 int len;
1896 p = ssh2_mpint_fmt(b, &len);
dacd8872 1897 ssh_pkt_addstring_start(pkt);
1898 ssh_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1899 sfree(p);
7cca0d81 1900}
b185170a 1901
dacd8872 1902static struct Packet *ssh1_pkt_init(int pkt_type)
1903{
1904 struct Packet *pkt = ssh_new_packet();
1905 pkt->length = 4 + 8; /* space for length + max padding */
1906 ssh_pkt_addbyte(pkt, pkt_type);
1907 pkt->body = pkt->data + pkt->length;
1908 return pkt;
1909}
1910
1911/* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1912#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1913#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1914#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1915#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1916#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1917#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1918#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1919#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1920
1921static struct Packet *ssh2_pkt_init(int pkt_type)
1922{
1923 struct Packet *pkt = ssh_new_packet();
3d71de0b 1924 pkt->length = 5; /* space for packet length + padding length */
dacd8872 1925 pkt->forcepad = 0;
1926 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
3d71de0b 1927 pkt->body = pkt->data + pkt->length; /* after packet type */
dacd8872 1928 return pkt;
1929}
1930
b185170a 1931/*
2e85c969 1932 * Construct an SSH-2 final-form packet: compress it, encrypt it,
b185170a 1933 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1934 * pkt->data. Total length is returned.
b185170a 1935 */
ff3187f6 1936static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1937{
7cca0d81 1938 int cipherblk, maclen, padding, i;
7cca0d81 1939
a8327734 1940 if (ssh->logctx)
ff3187f6 1941 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
acab36bc 1942 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
dacd8872 1943 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1944 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
ff3187f6 1945 sfree(pkt->blanks); pkt->blanks = NULL;
1946 pkt->nblanks = 0;
00db133f 1947
7cca0d81 1948 /*
4ba9b64b 1949 * Compress packet payload.
1950 */
4ba9b64b 1951 {
1952 unsigned char *newpayload;
1953 int newlen;
51470298 1954 if (ssh->cscomp &&
ff3187f6 1955 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1956 pkt->length - 5,
51470298 1957 &newpayload, &newlen)) {
ff3187f6 1958 pkt->length = 5;
1959 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1960 sfree(newpayload);
4ba9b64b 1961 }
1962 }
1963
1964 /*
7cca0d81 1965 * Add padding. At least four bytes, and must also bring total
1966 * length (minus MAC) up to a multiple of the block size.
95d2d262 1967 * If pkt->forcepad is set, make sure the packet is at least that size
1968 * after padding.
7cca0d81 1969 */
51470298 1970 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1971 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1972 padding = 4;
95d2d262 1973 if (pkt->length + padding < pkt->forcepad)
1974 padding = pkt->forcepad - pkt->length;
32874aea 1975 padding +=
ff3187f6 1976 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
95d2d262 1977 assert(padding <= 255);
51470298 1978 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1979 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1980 pkt->data[4] = padding;
7cca0d81 1981 for (i = 0; i < padding; i++)
ff3187f6 1982 pkt->data[pkt->length + i] = random_byte();
1983 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1984 if (ssh->csmac)
ff3187f6 1985 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1986 pkt->length + padding,
51470298 1987 ssh->v2_outgoing_sequence);
1988 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1989
1990 if (ssh->cscipher)
371e569c 1991 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1992 pkt->data, pkt->length + padding);
51470298 1993
9442dd57 1994 pkt->encrypted_len = pkt->length + padding;
1995
ff3187f6 1996 /* Ready-to-send packet starts at pkt->data. We return length. */
1997 return pkt->length + padding + maclen;
b185170a 1998}
1999
2000/*
590f6a5f 2001 * Routines called from the main SSH code to send packets. There
2002 * are quite a few of these, because we have two separate
2003 * mechanisms for delaying the sending of packets:
2004 *
2005 * - In order to send an IGNORE message and a password message in
2006 * a single fixed-length blob, we require the ability to
2007 * concatenate the encrypted forms of those two packets _into_ a
2008 * single blob and then pass it to our <network.h> transport
2009 * layer in one go. Hence, there's a deferment mechanism which
2010 * works after packet encryption.
2011 *
2012 * - In order to avoid sending any connection-layer messages
2013 * during repeat key exchange, we have to queue up any such
2014 * outgoing messages _before_ they are encrypted (and in
2015 * particular before they're allocated sequence numbers), and
2016 * then send them once we've finished.
2017 *
2018 * I call these mechanisms `defer' and `queue' respectively, so as
2019 * to distinguish them reasonably easily.
2020 *
2021 * The functions send_noqueue() and defer_noqueue() free the packet
2022 * structure they are passed. Every outgoing packet goes through
2023 * precisely one of these functions in its life; packets passed to
2024 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2025 * these or get queued, and then when the queue is later emptied
2026 * the packets are all passed to defer_noqueue().
97ab28d7 2027 *
2028 * When using a CBC-mode cipher, it's necessary to ensure that an
2029 * attacker can't provide data to be encrypted using an IV that they
2030 * know. We ensure this by prefixing each packet that might contain
2031 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2032 * mechanism, so in this case send_noqueue() ends up redirecting to
2033 * defer_noqueue(). If you don't like this inefficiency, don't use
2034 * CBC.
b185170a 2035 */
590f6a5f 2036
97ab28d7 2037static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2038static void ssh_pkt_defersend(Ssh);
2039
590f6a5f 2040/*
2e85c969 2041 * Send an SSH-2 packet immediately, without queuing or deferring.
590f6a5f 2042 */
2043static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 2044{
5471d09a 2045 int len;
2046 int backlog;
97ab28d7 2047 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2048 /* We need to send two packets, so use the deferral mechanism. */
2049 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2050 ssh_pkt_defersend(ssh);
2051 return;
2052 }
ff3187f6 2053 len = ssh2_pkt_construct(ssh, pkt);
bf8a49a1 2054 backlog = s_write(ssh, pkt->data, len);
5471d09a 2055 if (backlog > SSH_MAX_BACKLOG)
51470298 2056 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2057
2058 ssh->outgoing_data_size += pkt->encrypted_len;
2059 if (!ssh->kex_in_progress &&
d57f70af 2060 ssh->max_data_size != 0 &&
2061 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2062 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2063
ff3187f6 2064 ssh_free_packet(pkt);
b185170a 2065}
2066
2067/*
2e85c969 2068 * Defer an SSH-2 packet.
b185170a 2069 */
97ab28d7 2070static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
32874aea 2071{
97ab28d7 2072 int len;
2073 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
cf6ddb95 2074 ssh->deferred_len == 0 && !noignore &&
2075 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
97ab28d7 2076 /*
2077 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2078 * get encrypted with a known IV.
2079 */
2080 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
27311cc7 2081 ssh2_pkt_addstring_start(ipkt);
97ab28d7 2082 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2083 }
2084 len = ssh2_pkt_construct(ssh, pkt);
51470298 2085 if (ssh->deferred_len + len > ssh->deferred_size) {
2086 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 2087 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2088 ssh->deferred_size,
2089 unsigned char);
b185170a 2090 }
ff3187f6 2091 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 2092 ssh->deferred_len += len;
9442dd57 2093 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 2094 ssh_free_packet(pkt);
b185170a 2095}
2096
2097/*
2e85c969 2098 * Queue an SSH-2 packet.
590f6a5f 2099 */
2100static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2101{
2102 assert(ssh->queueing);
2103
2104 if (ssh->queuelen >= ssh->queuesize) {
2105 ssh->queuesize = ssh->queuelen + 32;
2106 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2107 }
2108
2109 ssh->queue[ssh->queuelen++] = pkt;
2110}
2111
2112/*
2113 * Either queue or send a packet, depending on whether queueing is
2114 * set.
2115 */
2116static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2117{
2118 if (ssh->queueing)
2119 ssh2_pkt_queue(ssh, pkt);
2120 else
2121 ssh2_pkt_send_noqueue(ssh, pkt);
2122}
2123
2124/*
2125 * Either queue or defer a packet, depending on whether queueing is
2126 * set.
2127 */
2128static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2129{
2130 if (ssh->queueing)
2131 ssh2_pkt_queue(ssh, pkt);
2132 else
97ab28d7 2133 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
590f6a5f 2134}
2135
2136/*
b185170a 2137 * Send the whole deferred data block constructed by
2e85c969 2138 * ssh2_pkt_defer() or SSH-1's defer_packet().
590f6a5f 2139 *
2140 * The expected use of the defer mechanism is that you call
2141 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2142 * not currently queueing, this simply sets up deferred_send_data
2143 * and then sends it. If we _are_ currently queueing, the calls to
2144 * ssh2_pkt_defer() put the deferred packets on to the queue
2145 * instead, and therefore ssh_pkt_defersend() has no deferred data
2146 * to send. Hence, there's no need to make it conditional on
2147 * ssh->queueing.
b185170a 2148 */
51470298 2149static void ssh_pkt_defersend(Ssh ssh)
32874aea 2150{
5471d09a 2151 int backlog;
bf8a49a1 2152 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
51470298 2153 ssh->deferred_len = ssh->deferred_size = 0;
2154 sfree(ssh->deferred_send_data);
2155 ssh->deferred_send_data = NULL;
5471d09a 2156 if (backlog > SSH_MAX_BACKLOG)
51470298 2157 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2158
2159 ssh->outgoing_data_size += ssh->deferred_data_size;
2160 if (!ssh->kex_in_progress &&
d57f70af 2161 ssh->max_data_size != 0 &&
2162 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2163 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2164 ssh->deferred_data_size = 0;
7cca0d81 2165}
2166
590f6a5f 2167/*
18524056 2168 * Send a packet whose length needs to be disguised (typically
2169 * passwords or keyboard-interactive responses).
2170 */
2171static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2172 int padsize)
2173{
2174#if 0
2175 if (0) {
2176 /*
2177 * The simplest way to do this is to adjust the
2178 * variable-length padding field in the outgoing packet.
2179 *
2180 * Currently compiled out, because some Cisco SSH servers
2181 * don't like excessively padded packets (bah, why's it
2182 * always Cisco?)
2183 */
2184 pkt->forcepad = padsize;
2185 ssh2_pkt_send(ssh, pkt);
2186 } else
2187#endif
2188 {
2189 /*
2190 * If we can't do that, however, an alternative approach is
2191 * to use the pkt_defer mechanism to bundle the packet
2192 * tightly together with an SSH_MSG_IGNORE such that their
2193 * combined length is a constant. So first we construct the
2194 * final form of this packet and defer its sending.
2195 */
2196 ssh2_pkt_defer(ssh, pkt);
2197
2198 /*
2199 * Now construct an SSH_MSG_IGNORE which includes a string
2200 * that's an exact multiple of the cipher block size. (If
2201 * the cipher is NULL so that the block size is
2202 * unavailable, we don't do this trick at all, because we
2203 * gain nothing by it.)
2204 */
cf6ddb95 2205 if (ssh->cscipher &&
2206 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
18524056 2207 int stringlen, i;
2208
2209 stringlen = (256 - ssh->deferred_len);
2210 stringlen += ssh->cscipher->blksize - 1;
2211 stringlen -= (stringlen % ssh->cscipher->blksize);
2212 if (ssh->cscomp) {
2213 /*
2214 * Temporarily disable actual compression, so we
2215 * can guarantee to get this string exactly the
2216 * length we want it. The compression-disabling
2217 * routine should return an integer indicating how
2218 * many bytes we should adjust our string length
2219 * by.
2220 */
2221 stringlen -=
2222 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2223 }
2224 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2225 ssh2_pkt_addstring_start(pkt);
2226 for (i = 0; i < stringlen; i++) {
2227 char c = (char) random_byte();
2228 ssh2_pkt_addstring_data(pkt, &c, 1);
2229 }
2230 ssh2_pkt_defer(ssh, pkt);
2231 }
2232 ssh_pkt_defersend(ssh);
2233 }
2234}
2235
2236/*
2e85c969 2237 * Send all queued SSH-2 packets. We send them by means of
590f6a5f 2238 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2239 * packets that needed to be lumped together.
2240 */
2241static void ssh2_pkt_queuesend(Ssh ssh)
2242{
2243 int i;
2244
2245 assert(!ssh->queueing);
2246
2247 for (i = 0; i < ssh->queuelen; i++)
97ab28d7 2248 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
590f6a5f 2249 ssh->queuelen = 0;
2250
2251 ssh_pkt_defersend(ssh);
2252}
2253
7cca0d81 2254#if 0
32874aea 2255void bndebug(char *string, Bignum b)
2256{
7cca0d81 2257 unsigned char *p;
2258 int i, len;
2259 p = ssh2_mpint_fmt(b, &len);
2260 debug(("%s", string));
2261 for (i = 0; i < len; i++)
32874aea 2262 debug((" %02x", p[i]));
765c4200 2263 debug(("\n"));
dcbde236 2264 sfree(p);
7cca0d81 2265}
2266#endif
2267
b672f405 2268static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
32874aea 2269{
7cca0d81 2270 unsigned char *p;
2271 int len;
2272 p = ssh2_mpint_fmt(b, &len);
b672f405 2273 hash_string(h, s, p, len);
dcbde236 2274 sfree(p);
7cca0d81 2275}
2276
2277/*
2e85c969 2278 * Packet decode functions for both SSH-1 and SSH-2.
7cca0d81 2279 */
ff3187f6 2280static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 2281{
7cca0d81 2282 unsigned long value;
ff3187f6 2283 if (pkt->length - pkt->savedpos < 4)
32874aea 2284 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2285 value = GET_32BIT(pkt->body + pkt->savedpos);
2286 pkt->savedpos += 4;
7cca0d81 2287 return value;
2288}
ff3187f6 2289static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 2290{
65a22376 2291 unsigned long value;
ff3187f6 2292 if (pkt->length - pkt->savedpos < 1)
32874aea 2293 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2294 value = pkt->body[pkt->savedpos] != 0;
2295 pkt->savedpos++;
65a22376 2296 return value;
2297}
ff3187f6 2298static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 2299{
57356d63 2300 int len;
7cca0d81 2301 *p = NULL;
45068b27 2302 *length = 0;
ff3187f6 2303 if (pkt->length - pkt->savedpos < 4)
32874aea 2304 return;
ff3187f6 2305 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 2306 if (len < 0)
2307 return;
2308 *length = len;
ff3187f6 2309 pkt->savedpos += 4;
2310 if (pkt->length - pkt->savedpos < *length)
32874aea 2311 return;
ff3187f6 2312 *p = (char *)(pkt->body + pkt->savedpos);
2313 pkt->savedpos += *length;
7cca0d81 2314}
ff3187f6 2315static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 2316{
ff3187f6 2317 if (pkt->length - pkt->savedpos < length)
0016d70b 2318 return NULL;
ff3187f6 2319 pkt->savedpos += length;
2320 return pkt->body + (pkt->savedpos - length);
0016d70b 2321}
ff3187f6 2322static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 2323 unsigned char **keystr)
2324{
2325 int j;
2326
ff3187f6 2327 j = makekey(pkt->body + pkt->savedpos,
2328 pkt->length - pkt->savedpos,
0016d70b 2329 key, keystr, 0);
2330
2331 if (j < 0)
2332 return FALSE;
2333
ff3187f6 2334 pkt->savedpos += j;
2335 assert(pkt->savedpos < pkt->length);
0016d70b 2336
2337 return TRUE;
2338}
ff3187f6 2339static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 2340{
2341 int j;
2342 Bignum b;
2343
ff3187f6 2344 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2345 pkt->length - pkt->savedpos, &b);
0016d70b 2346
2347 if (j < 0)
2348 return NULL;
2349
ff3187f6 2350 pkt->savedpos += j;
0016d70b 2351 return b;
2352}
ff3187f6 2353static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 2354{
7cca0d81 2355 char *p;
3709bfe9 2356 int length;
7cca0d81 2357 Bignum b;
2358
ff3187f6 2359 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 2360 if (!p)
32874aea 2361 return NULL;
ff3187f6 2362 if (p[0] & 0x80)
32874aea 2363 return NULL;
d8baa528 2364 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 2365 return b;
2366}
2367
7d503c31 2368/*
2e85c969 2369 * Helper function to add an SSH-2 signature blob to a packet.
1dd353b5 2370 * Expects to be shown the public key blob as well as the signature
2371 * blob. Normally works just like ssh2_pkt_addstring, but will
2372 * fiddle with the signature packet if necessary for
2373 * BUG_SSH2_RSA_PADDING.
2374 */
ff3187f6 2375static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2376 void *pkblob_v, int pkblob_len,
1dd353b5 2377 void *sigblob_v, int sigblob_len)
2378{
2379 unsigned char *pkblob = (unsigned char *)pkblob_v;
2380 unsigned char *sigblob = (unsigned char *)sigblob_v;
2381
2382 /* dmemdump(pkblob, pkblob_len); */
2383 /* dmemdump(sigblob, sigblob_len); */
2384
2385 /*
2386 * See if this is in fact an ssh-rsa signature and a buggy
2387 * server; otherwise we can just do this the easy way.
2388 */
51470298 2389 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 2390 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2391 int pos, len, siglen;
2392
2393 /*
2394 * Find the byte length of the modulus.
2395 */
2396
2397 pos = 4+7; /* skip over "ssh-rsa" */
2398 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2399 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2400 pos += 4; /* find modulus itself */
2401 while (len > 0 && pkblob[pos] == 0)
2402 len--, pos++;
2403 /* debug(("modulus length is %d\n", len)); */
2404
2405 /*
2406 * Now find the signature integer.
2407 */
2408 pos = 4+7; /* skip over "ssh-rsa" */
2409 siglen = GET_32BIT(sigblob+pos);
2410 /* debug(("signature length is %d\n", siglen)); */
2411
2412 if (len != siglen) {
2413 unsigned char newlen[4];
ff3187f6 2414 ssh2_pkt_addstring_start(pkt);
2415 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2416 /* dmemdump(sigblob, pos); */
2417 pos += 4; /* point to start of actual sig */
2418 PUT_32BIT(newlen, len);
ff3187f6 2419 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2420 /* dmemdump(newlen, 4); */
2421 newlen[0] = 0;
2422 while (len-- > siglen) {
ff3187f6 2423 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2424 /* dmemdump(newlen, 1); */
2425 }
ff3187f6 2426 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2427 /* dmemdump(sigblob+pos, siglen); */
2428 return;
2429 }
2430
2431 /* Otherwise fall through and do it the easy way. */
2432 }
2433
ff3187f6 2434 ssh2_pkt_addstring_start(pkt);
2435 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2436}
2437
2438/*
7d503c31 2439 * Examine the remote side's version string and compare it against
2440 * a list of known buggy implementations.
2441 */
51470298 2442static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2443{
2444 char *imp; /* pointer to implementation part */
7d503c31 2445 imp = vstring;
2446 imp += strcspn(imp, "-");
bd358db1 2447 if (*imp) imp++;
7d503c31 2448 imp += strcspn(imp, "-");
bd358db1 2449 if (*imp) imp++;
7d503c31 2450
51470298 2451 ssh->remote_bugs = 0;
7d503c31 2452
bf982899 2453 /*
2454 * General notes on server version strings:
2455 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2456 * here -- in particular, we've heard of one that's perfectly happy
2457 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2458 * so we can't distinguish them.
2459 */
4a693cfc 2460 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2461 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2c9c6388 2462 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2463 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2464 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2465 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2466 /*
2467 * These versions don't support SSH1_MSG_IGNORE, so we have
2468 * to use a different defence against password length
2469 * sniffing.
2470 */
51470298 2471 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2e85c969 2472 logevent("We believe remote version has SSH-1 ignore bug");
7d503c31 2473 }
2474
4a693cfc 2475 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2476 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
46ac09aa 2477 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2478 /*
2479 * These versions need a plain password sent; they can't
2480 * handle having a null and a random length of data after
2481 * the password.
2482 */
51470298 2483 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2e85c969 2484 logevent("We believe remote version needs a plain SSH-1 password");
bd358db1 2485 }
2486
4a693cfc 2487 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2488 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2c9c6388 2489 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2490 /*
2491 * These versions apparently have no clue whatever about
2492 * RSA authentication and will panic and die if they see
2493 * an AUTH_RSA message.
2494 */
51470298 2495 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
19f47a7d 2496 logevent("We believe remote version can't handle SSH-1 RSA authentication");
0df73905 2497 }
2498
4a693cfc 2499 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2500 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
b9f387af 2501 !wc_match("* VShell", imp) &&
831301f6 2502 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2503 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2504 wc_match("2.1 *", imp)))) {
32874aea 2505 /*
2506 * These versions have the HMAC bug.
2507 */
51470298 2508 ssh->remote_bugs |= BUG_SSH2_HMAC;
2e85c969 2509 logevent("We believe remote version has SSH-2 HMAC bug");
7d503c31 2510 }
1dd353b5 2511
4a693cfc 2512 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2513 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
b9f387af 2514 !wc_match("* VShell", imp) &&
2856a1b9 2515 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2516 /*
2517 * These versions have the key-derivation bug (failing to
2518 * include the literal shared secret in the hashes that
2519 * generate the keys).
2520 */
51470298 2521 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2e85c969 2522 logevent("We believe remote version has SSH-2 key-derivation bug");
088bde77 2523 }
2524
4a693cfc 2525 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2526 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
831301f6 2527 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2528 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2529 /*
2e85c969 2530 * These versions have the SSH-2 RSA padding bug.
1dd353b5 2531 */
51470298 2532 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2e85c969 2533 logevent("We believe remote version has SSH-2 RSA padding bug");
1dd353b5 2534 }
8e975795 2535
4a693cfc 2536 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2537 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
dda87a28 2538 wc_match("OpenSSH_2.[0-2]*", imp))) {
2539 /*
2e85c969 2540 * These versions have the SSH-2 session-ID bug in
dda87a28 2541 * public-key authentication.
2542 */
2543 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2e85c969 2544 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
dda87a28 2545 }
f382c87d 2546
4a693cfc 2547 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2548 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
39b8712f 2549 (wc_match("DigiSSH_2.0", imp) ||
2550 wc_match("OpenSSH_2.[0-4]*", imp) ||
e12d95a5 2551 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2552 wc_match("Sun_SSH_1.0", imp) ||
f4275b53 2553 wc_match("Sun_SSH_1.0.1", imp) ||
96bd26de 2554 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2555 wc_match("WeOnlyDo-*", imp)))) {
f382c87d 2556 /*
2e85c969 2557 * These versions have the SSH-2 rekey bug.
f382c87d 2558 */
2559 ssh->remote_bugs |= BUG_SSH2_REKEY;
2e85c969 2560 logevent("We believe remote version has SSH-2 rekey bug");
f382c87d 2561 }
c9739dba 2562
4a693cfc 2563 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2564 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
5ca836f2 2565 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2566 wc_match("1.36 sshlib: GlobalScape", imp)))) {
c9739dba 2567 /*
2568 * This version ignores our makpkt and needs to be throttled.
2569 */
2570 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2571 logevent("We believe remote version ignores SSH-2 maximum packet size");
2572 }
cf6ddb95 2573
4a693cfc 2574 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
cf6ddb95 2575 /*
2576 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2577 * none detected automatically.
2578 */
2579 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2580 logevent("We believe remote version has SSH-2 ignore bug");
2581 }
2e0aae4f 2582
2583 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2584 /*
2585 * Servers that don't support our winadj request for one
2586 * reason or another. Currently, none detected automatically.
2587 */
2588 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2589 logevent("We believe remote version has winadj bug");
2590 }
7d503c31 2591}
2592
d38d6a1f 2593/*
2594 * The `software version' part of an SSH version string is required
2595 * to contain no spaces or minus signs.
2596 */
2597static void ssh_fix_verstring(char *str)
2598{
2599 /* Eat "SSH-<protoversion>-". */
2600 assert(*str == 'S'); str++;
2601 assert(*str == 'S'); str++;
2602 assert(*str == 'H'); str++;
2603 assert(*str == '-'); str++;
2604 while (*str && *str != '-') str++;
2605 assert(*str == '-'); str++;
2606
2607 /* Convert minus signs and spaces in the remaining string into
2608 * underscores. */
2609 while (*str) {
2610 if (*str == '-' || *str == ' ')
2611 *str = '_';
2612 str++;
2613 }
2614}
2615
1fcd0d98 2616/*
2617 * Send an appropriate SSH version string.
2618 */
2619static void ssh_send_verstring(Ssh ssh, char *svers)
2620{
2621 char *verstring;
2622
2623 if (ssh->version == 2) {
2624 /*
2625 * Construct a v2 version string.
2626 */
2627 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2628 } else {
2629 /*
2630 * Construct a v1 version string.
2631 */
2632 verstring = dupprintf("SSH-%s-%s\012",
2633 (ssh_versioncmp(svers, "1.5") <= 0 ?
2634 svers : "1.5"),
2635 sshver);
2636 }
2637
2638 ssh_fix_verstring(verstring);
2639
2640 if (ssh->version == 2) {
2641 size_t len;
2642 /*
2643 * Record our version string.
2644 */
2645 len = strcspn(verstring, "\015\012");
2646 ssh->v_c = snewn(len + 1, char);
2647 memcpy(ssh->v_c, verstring, len);
2648 ssh->v_c[len] = 0;
2649 }
2650
2651 logeventf(ssh, "We claim version: %.*s",
2652 strcspn(verstring, "\015\012"), verstring);
2653 s_write(ssh, verstring, strlen(verstring));
2654 sfree(verstring);
2655}
2656
51470298 2657static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2658{
51470298 2659 struct do_ssh_init_state {
30919997 2660 int crLine;
51470298 2661 int vslen;
2662 char version[10];
2663 char *vstring;
2664 int vstrsize;
2665 int i;
2666 int proto1, proto2;
2667 };
2668 crState(do_ssh_init_state);
30919997 2669
2670 crBeginState;
8df7a775 2671
8c1835c0 2672 /* Search for a line beginning with the string "SSH-" in the input. */
2673 for (;;) {
2674 if (c != 'S') goto no;
2675 crReturn(1);
2676 if (c != 'S') goto no;
2677 crReturn(1);
2678 if (c != 'H') goto no;
2679 crReturn(1);
2680 if (c != '-') goto no;
2681 break;
2682 no:
2683 while (c != '\012')
2684 crReturn(1);
2685 crReturn(1);
374330e2 2686 }
8df7a775 2687
51470298 2688 s->vstrsize = 16;
3d88e64d 2689 s->vstring = snewn(s->vstrsize, char);
51470298 2690 strcpy(s->vstring, "SSH-");
2691 s->vslen = 4;
2692 s->i = 0;
374330e2 2693 while (1) {
8df7a775 2694 crReturn(1); /* get another char */
51470298 2695 if (s->vslen >= s->vstrsize - 1) {
2696 s->vstrsize += 16;
3d88e64d 2697 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2698 }
51470298 2699 s->vstring[s->vslen++] = c;
2700 if (s->i >= 0) {
374330e2 2701 if (c == '-') {
51470298 2702 s->version[s->i] = '\0';
2703 s->i = -1;
2704 } else if (s->i < sizeof(s->version) - 1)
2705 s->version[s->i++] = c;
c4ffc4d0 2706 } else if (c == '\012')
374330e2 2707 break;
2708 }
2709
51470298 2710 ssh->agentfwd_enabled = FALSE;
2711 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2712
51470298 2713 s->vstring[s->vslen] = 0;
a7d4653a 2714 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
fb983202 2715 logeventf(ssh, "Server version: %s", s->vstring);
51470298 2716 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2717
adf799dd 2718 /*
38d228a2 2719 * Decide which SSH protocol version to support.
adf799dd 2720 */
38d228a2 2721
2722 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2723 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2724 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2725 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2726
4a693cfc 2727 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
6b5cf8b4 2728 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2729 crStop(0);
38d228a2 2730 }
4a693cfc 2731 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
6b5cf8b4 2732 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2733 crStop(0);
38d228a2 2734 }
2735
4a693cfc 2736 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
1fcd0d98 2737 ssh->version = 2;
2738 else
2739 ssh->version = 1;
d38d6a1f 2740
2741 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2742
1fcd0d98 2743 /* Send the version string, if we haven't already */
4a693cfc 2744 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
1fcd0d98 2745 ssh_send_verstring(ssh, s->version);
2746
2747 if (ssh->version == 2) {
2748 size_t len;
2749 /*
2750 * Record their version string.
2751 */
2752 len = strcspn(s->vstring, "\015\012");
2753 ssh->v_s = snewn(len + 1, char);
2754 memcpy(ssh->v_s, s->vstring, len);
2755 ssh->v_s[len] = 0;
2756
2757 /*
2758 * Initialise SSH-2 protocol.
2759 */
2760 ssh->protocol = ssh2_protocol;
2761 ssh2_protocol_setup(ssh);
2762 ssh->s_rdpkt = ssh2_rdpkt;
2763 } else {
2764 /*
2765 * Initialise SSH-1 protocol.
2766 */
2767 ssh->protocol = ssh1_protocol;
2768 ssh1_protocol_setup(ssh);
2769 ssh->s_rdpkt = ssh1_rdpkt;
2770 }
2771 if (ssh->version == 2)
2772 do_ssh2_transport(ssh, NULL, -1, NULL);
2773
125105d1 2774 update_specials_menu(ssh->frontend);
51470298 2775 ssh->state = SSH_STATE_BEFORE_SIZE;
4a693cfc 2776 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
8df7a775 2777
51470298 2778 sfree(s->vstring);
50526e47 2779
8df7a775 2780 crFinish(0);
2781}
2782
3d9449a1 2783static void ssh_process_incoming_data(Ssh ssh,
2784 unsigned char **data, int *datalen)
2785{
bf8a49a1 2786 struct Packet *pktin;
2787
2788 pktin = ssh->s_rdpkt(ssh, data, datalen);
3d9449a1 2789 if (pktin) {
2790 ssh->protocol(ssh, NULL, 0, pktin);
2791 ssh_free_packet(pktin);
2792 }
2793}
2794
2795static void ssh_queue_incoming_data(Ssh ssh,
2796 unsigned char **data, int *datalen)
2797{
2798 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2799 *data += *datalen;
2800 *datalen = 0;
2801}
2802
2803static void ssh_process_queued_incoming_data(Ssh ssh)
2804{
2805 void *vdata;
2806 unsigned char *data;
2807 int len, origlen;
2808
2809 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2810 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2811 data = vdata;
2812 origlen = len;
2813
2814 while (!ssh->frozen && len > 0)
2815 ssh_process_incoming_data(ssh, &data, &len);
2816
2817 if (origlen > len)
2818 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2819 }
2820}
2821
2822static void ssh_set_frozen(Ssh ssh, int frozen)
2823{
a5a6f839 2824 if (ssh->s)
2825 sk_set_frozen(ssh->s, frozen);
3d9449a1 2826 ssh->frozen = frozen;
2827}
2828
51470298 2829static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2830{
bf8a49a1 2831 /* Log raw data, if we're in that mode. */
ff05dfef 2832 if (ssh->logctx)
2833 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
0d13bfcd 2834 0, NULL, NULL);
bf8a49a1 2835
51470298 2836 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2837
2838 /*
2839 * To begin with, feed the characters one by one to the
2840 * protocol initialisation / selection function do_ssh_init().
2841 * When that returns 0, we're done with the initial greeting
2842 * exchange and can move on to packet discipline.
2843 */
2844 while (1) {
51470298 2845 int ret; /* need not be kept across crReturn */
8df7a775 2846 if (datalen == 0)
2847 crReturnV; /* more data please */
51470298 2848 ret = do_ssh_init(ssh, *data);
32874aea 2849 data++;
2850 datalen--;
8df7a775 2851 if (ret == 0)
2852 break;
2853 }
2854
2855 /*
2856 * We emerge from that loop when the initial negotiation is
2857 * over and we have selected an s_rdpkt function. Now pass
2858 * everything to s_rdpkt, and then pass the resulting packets
2859 * to the proper protocol handler.
2860 */
3d9449a1 2861
8df7a775 2862 while (1) {
e375106c 2863 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2864 if (ssh->frozen) {
3d9449a1 2865 ssh_queue_incoming_data(ssh, &data, &datalen);
e375106c 2866 /* This uses up all data and cannot cause anything interesting
2867 * to happen; indeed, for anything to happen at all, we must
2868 * return, so break out. */
2869 break;
2870 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2871 /* This uses up some or all data, and may freeze the
2872 * session. */
2873 ssh_process_queued_incoming_data(ssh);
2874 } else {
2875 /* This uses up some or all data, and may freeze the
2876 * session. */
2877 ssh_process_incoming_data(ssh, &data, &datalen);
2878 }
2879 /* FIXME this is probably EBW. */
ff3187f6 2880 if (ssh->state == SSH_STATE_CLOSED)
2881 return;
8df7a775 2882 }
e375106c 2883 /* We're out of data. Go and get some more. */
8df7a775 2884 crReturnV;
2885 }
2886 crFinishV;
2887}
2888
ac934965 2889static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2890{
80ffa58b 2891 int ret = 0;
36f94d1f 2892 struct ssh_channel *c;
2893
51470298 2894 ssh->state = SSH_STATE_CLOSED;
ecbb0000 2895 expire_timer_context(ssh);
51470298 2896 if (ssh->s) {
2897 sk_close(ssh->s);
2898 ssh->s = NULL;
ac934965 2899 if (notify_exit)
2900 notify_remote_exit(ssh->frontend);
2901 else
2902 ret = 1;
f3ab576e 2903 }
36f94d1f 2904 /*
80ffa58b 2905 * Now we must shut down any port- and X-forwarded channels going
36f94d1f 2906 * through this connection.
2907 */
74a98066 2908 if (ssh->channels) {
80ffa58b 2909 while (NULL != (c = index234(ssh->channels, 0))) {
74a98066 2910 switch (c->type) {
2911 case CHAN_X11:
2912 x11_close(c->u.x11.s);
2913 break;
2914 case CHAN_SOCKDATA:
409eca86 2915 case CHAN_SOCKDATA_DORMANT:
74a98066 2916 pfd_close(c->u.pfd.s);
2917 break;
2918 }
80ffa58b 2919 del234(ssh->channels, c); /* moving next one to index 0 */
74a98066 2920 if (ssh->version == 2)
2921 bufchain_clear(&c->v.v2.outbuffer);
2922 sfree(c);
36f94d1f 2923 }
36f94d1f 2924 }
f8c9f9df 2925 /*
2926 * Go through port-forwardings, and close any associated
2927 * listening sockets.
2928 */
2929 if (ssh->portfwds) {
2930 struct ssh_portfwd *pf;
2931 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2932 /* Dispose of any listening socket. */
2933 if (pf->local)
2934 pfd_terminate(pf->local);
2935 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2936 free_portfwd(pf);
2937 }
b72bdf11 2938 freetree234(ssh->portfwds);
2939 ssh->portfwds = NULL;
f8c9f9df 2940 }
ac934965 2941
2942 return ret;
36f94d1f 2943}
2944
7555d6a5 2945static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2946 const char *error_msg, int error_code)
2947{
2948 Ssh ssh = (Ssh) plug;
2949 char addrbuf[256], *msg;
2950
2951 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2952
2953 if (type == 0)
2954 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2955 else
2956 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2957
2958 logevent(msg);
fb983202 2959 sfree(msg);
7555d6a5 2960}
2961
cbe2d68f 2962static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2963 int calling_back)
2964{
2965 Ssh ssh = (Ssh) plug;
ac934965 2966 int need_notify = ssh_do_close(ssh, FALSE);
2967
9e296bfa 2968 if (!error_msg) {
2969 if (!ssh->close_expected)
2970 error_msg = "Server unexpectedly closed network connection";
2971 else
2972 error_msg = "Server closed network connection";
ac934965 2973 }
2974
d051d1b4 2975 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2976 ssh->exitcode = 0;
2977
2425184b 2978 if (need_notify)
2979 notify_remote_exit(ssh->frontend);
2980
9e296bfa 2981 if (error_msg)
247308b5 2982 logevent(error_msg);
9e296bfa 2983 if (!ssh->close_expected || !ssh->clean_exit)
971bcc0a 2984 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2985 return 0;
2986}
2987
32874aea 2988static int ssh_receive(Plug plug, int urgent, char *data, int len)
2989{
51470298 2990 Ssh ssh = (Ssh) plug;
d8baa528 2991 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2992 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 2993 ssh_do_close(ssh, TRUE);
32874aea 2994 return 0;
3257deae 2995 }
fef97f43 2996 return 1;
374330e2 2997}
2998
5471d09a 2999static void ssh_sent(Plug plug, int bufsize)
3000{
51470298 3001 Ssh ssh = (Ssh) plug;
5471d09a 3002 /*
3003 * If the send backlog on the SSH socket itself clears, we
3004 * should unthrottle the whole world if it was throttled.
3005 */
3006 if (bufsize < SSH_MAX_BACKLOG)
51470298 3007 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 3008}
3009
fb09bf1c 3010/*
8df7a775 3011 * Connect to specified host and port.
3012 * Returns an error message, or NULL on success.
6e1ebb76 3013 * Also places the canonical host name into `realhost'. It must be
3014 * freed by the caller.
8df7a775 3015 */
cbe2d68f 3016static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 3017 char **realhost, int nodelay, int keepalive)
8df7a775 3018{
51470298 3019 static const struct plug_function_table fn_table = {
7555d6a5 3020 ssh_log,
7e78000d 3021 ssh_closing,
5471d09a 3022 ssh_receive,
3023 ssh_sent,
3024 NULL
51470298 3025 };
7e78000d 3026
8df7a775 3027 SockAddr addr;
cbe2d68f 3028 const char *err;
4a693cfc 3029 char *loghost;
3030 int addressfamily, sshprot;
3031
3032 loghost = conf_get_str(ssh->conf, CONF_loghost);
3033 if (*loghost) {
881da168 3034 char *colon;
8df7a775 3035
4a693cfc 3036 ssh->savedhost = dupstr(loghost);
881da168 3037 ssh->savedport = 22; /* default ssh port */
3038
3039 /*
3040 * A colon suffix on savedhost also lets us affect
3041 * savedport.
3042 *
3043 * (FIXME: do something about IPv6 address literals here.)
3044 */
3045 colon = strrchr(ssh->savedhost, ':');
3046 if (colon) {
3047 *colon++ = '\0';
3048 if (*colon)
3049 ssh->savedport = atoi(colon);
3050 }
3051 } else {
3052 ssh->savedhost = dupstr(host);
3053 if (port < 0)
3054 port = 22; /* default ssh port */
3055 ssh->savedport = port;
3056 }
8df7a775 3057
3058 /*
3059 * Try to find host.
3060 */
4a693cfc 3061 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
05581745 3062 logeventf(ssh, "Looking up host \"%s\"%s", host,
4a693cfc 3063 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3064 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3065 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
170c1e6e 3066 if ((err = sk_addr_error(addr)) != NULL) {
3067 sk_addr_free(addr);
8df7a775 3068 return err;
170c1e6e 3069 }
42af6a67 3070 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
8df7a775 3071
8df7a775 3072 /*
3073 * Open socket.
3074 */
51470298 3075 ssh->fn = &fn_table;
e8fa8f62 3076 ssh->s = new_connection(addr, *realhost, port,
4a693cfc 3077 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
70e5d0fd 3078 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 3079 ssh->s = NULL;
39934deb 3080 notify_remote_exit(ssh->frontend);
8df7a775 3081 return err;
67c4ba2e 3082 }
8df7a775 3083
ff05dfef 3084 /*
3085 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3086 * send the version string too.
3087 */
4a693cfc 3088 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3089 if (sshprot == 0)
ff05dfef 3090 ssh->version = 1;
4a693cfc 3091 if (sshprot == 3) {
ff05dfef 3092 ssh->version = 2;
3093 ssh_send_verstring(ssh, NULL);
3094 }
3095
881da168 3096 /*
3097 * loghost, if configured, overrides realhost.
3098 */
4a693cfc 3099 if (*loghost) {
881da168 3100 sfree(*realhost);
4a693cfc 3101 *realhost = dupstr(loghost);
881da168 3102 }
3103
8df7a775 3104 return NULL;
3105}
3106
3107/*
5471d09a 3108 * Throttle or unthrottle the SSH connection.
3109 */
ff68564b 3110static void ssh_throttle_conn(Ssh ssh, int adjust)
5471d09a 3111{
ff68564b 3112 int old_count = ssh->conn_throttle_count;
3113 ssh->conn_throttle_count += adjust;
3114 assert(ssh->conn_throttle_count >= 0);
3115 if (ssh->conn_throttle_count && !old_count) {
3d9449a1 3116 ssh_set_frozen(ssh, 1);
ff68564b 3117 } else if (!ssh->conn_throttle_count && old_count) {
3d9449a1 3118 ssh_set_frozen(ssh, 0);
5471d09a 3119 }
3120}
3121
3122/*
3123 * Throttle or unthrottle _all_ local data streams (for when sends
3124 * on the SSH connection itself back up).
3125 */
51470298 3126static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 3127{
3128 int i;
3129 struct ssh_channel *c;
3130
51470298 3131 if (enable == ssh->throttled_all)
5471d09a 3132 return;
51470298 3133 ssh->throttled_all = enable;
3134 ssh->overall_bufsize = bufsize;
3135 if (!ssh->channels)
5471d09a 3136 return;
51470298 3137 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 3138 switch (c->type) {
3139 case CHAN_MAINSESSION:
3140 /*
3141 * This is treated separately, outside the switch.
3142 */
3143 break;
3144 case CHAN_X11:
3145 x11_override_throttle(c->u.x11.s, enable);
3146 break;
3147 case CHAN_AGENT:
3148 /* Agent channels require no buffer management. */
3149 break;
3150 case CHAN_SOCKDATA:
36f94d1f 3151 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 3152 break;
3153 }
3154 }
3155}
3156
f11d78f2 3157static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 3158{
3159 Ssh ssh = (Ssh) sshv;
3160
3161 ssh->agent_response = reply;
3162 ssh->agent_response_len = replylen;
3163
3164 if (ssh->version == 1)
ff3187f6 3165 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 3166 else
ff3187f6 3167 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 3168}
3169
3d9449a1 3170static void ssh_dialog_callback(void *sshv, int ret)
3171{
3172 Ssh ssh = (Ssh) sshv;
3173
3174 ssh->user_response = ret;
3175
3176 if (ssh->version == 1)
3177 do_ssh1_login(ssh, NULL, -1, NULL);
3178 else
3179 do_ssh2_transport(ssh, NULL, -1, NULL);
3180
3181 /*
3182 * This may have unfrozen the SSH connection, so do a
3183 * queued-data run.
3184 */
3185 ssh_process_queued_incoming_data(ssh);
3186}
3187
f11d78f2 3188static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 3189{
3190 struct ssh_channel *c = (struct ssh_channel *)cv;
3191 Ssh ssh = c->ssh;
3192 void *sentreply = reply;
3193
3194 if (!sentreply) {
3195 /* Fake SSH_AGENT_FAILURE. */
3196 sentreply = "\0\0\0\1\5";
3197 replylen = 5;
3198 }
3199 if (ssh->version == 2) {
3200 ssh2_add_channel_data(c, sentreply, replylen);
3201 ssh2_try_send(c);
3202 } else {
3203 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3204 PKT_INT, c->remoteid,
3205 PKT_INT, replylen,
a2724fba 3206 PKTT_DATA,
839f10db 3207 PKT_DATA, sentreply, replylen,
9a10ecf4 3208 PKTT_OTHER,
839f10db 3209 PKT_END);
3210 }
3211 if (reply)
3212 sfree(reply);
3213}
3214
0405e71f 3215/*
9e296bfa 3216 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3217 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3218 * => log `wire_reason'.
3219 */
3220static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3221 int code, int clean_exit)
3222{
3223 char *error;
3224 if (!client_reason)
3225 client_reason = wire_reason;
3226 if (client_reason)
3227 error = dupprintf("Disconnected: %s", client_reason);
3228 else
3229 error = dupstr("Disconnected");
3230 if (wire_reason) {
3231 if (ssh->version == 1) {
3232 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3233 PKT_END);
3234 } else if (ssh->version == 2) {
3235 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3236 ssh2_pkt_adduint32(pktout, code);
3237 ssh2_pkt_addstring(pktout, wire_reason);
3238 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3239 ssh2_pkt_send_noqueue(ssh, pktout);
3240 }
3241 }
3242 ssh->close_expected = TRUE;
3243 ssh->clean_exit = clean_exit;
3244 ssh_closing((Plug)ssh, error, 0, 0);
3245 sfree(error);
3246}
3247
3248/*
fb09bf1c 3249 * Handle the key exchange and user authentication phases.
3250 */
ff3187f6 3251static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3252 struct Packet *pktin)
fb09bf1c 3253{
0016d70b 3254 int i, j, ret;
3255 unsigned char cookie[8], *ptr;
374330e2 3256 struct RSAKey servkey, hostkey;
3257 struct MD5Context md5c;
51470298 3258 struct do_ssh1_login_state {
30919997 3259 int crLine;
51470298 3260 int len;
3261 unsigned char *rsabuf, *keystr1, *keystr2;
3262 unsigned long supported_ciphers_mask, supported_auths_mask;
3263 int tried_publickey, tried_agent;
3264 int tis_auth_refused, ccard_auth_refused;
3265 unsigned char session_id[16];
3266 int cipher_type;
51470298 3267 void *publickey_blob;
3268 int publickey_bloblen;
edd0cb8a 3269 char *publickey_comment;
3270 int publickey_encrypted;
3271 prompts_t *cur_prompt;
51470298 3272 char c;
3273 int pwpkt_type;
3274 unsigned char request[5], *response, *p;
3275 int responselen;
3276 int keyi, nkeys;
3277 int authed;
3278 struct RSAKey key;
3279 Bignum challenge;
3280 char *commentp;
3281 int commentlen;
3d9449a1 3282 int dlgret;
4a693cfc 3283 Filename *keyfile;
51470298 3284 };
3285 crState(do_ssh1_login_state);
3286
30919997 3287 crBeginState;
374330e2 3288
ff3187f6 3289 if (!pktin)
3290 crWaitUntil(pktin);
374330e2 3291
ff3187f6 3292 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 3293 bombout(("Public key packet not received"));
7ffdbc1a 3294 crStop(0);
8d5de777 3295 }
374330e2 3296
c5e9c988 3297 logevent("Received public keys");
374330e2 3298
ff3187f6 3299 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 3300 if (!ptr) {
2e85c969 3301 bombout(("SSH-1 public key packet stopped before random cookie"));
0016d70b 3302 crStop(0);
3303 }
3304 memcpy(cookie, ptr, 8);
374330e2 3305
ff3187f6 3306 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3307 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2e85c969 3308 bombout(("Failed to read SSH-1 public keys from public key packet"));
0016d70b 3309 crStop(0);
3310 }
374330e2 3311
c5e9c988 3312 /*
1c2a93c4 3313 * Log the host key fingerprint.
c5e9c988 3314 */
c5e9c988 3315 {
3316 char logmsg[80];
1c2a93c4 3317 logevent("Host key fingerprint is:");
c5e9c988 3318 strcpy(logmsg, " ");
32874aea 3319 hostkey.comment = NULL;
3320 rsa_fingerprint(logmsg + strlen(logmsg),
3321 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 3322 logevent(logmsg);
3323 }
3324
ff3187f6 3325 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3326 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3327 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
d5b2c841 3328 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3329 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
bea1ef5f 3330
51470298 3331 ssh->v1_local_protoflags =
3332 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3333 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 3334
c5e9c988 3335 MD5Init(&md5c);
51470298 3336 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3337 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 3338 MD5Update(&md5c, cookie, 8);
51470298 3339 MD5Final(s->session_id, &md5c);
374330e2 3340
32874aea 3341 for (i = 0; i < 32; i++)
51470298 3342 ssh->session_key[i] = random_byte();
374330e2 3343
0016d70b 3344 /*
3345 * Verify that the `bits' and `bytes' parameters match.
3346 */
3347 if (hostkey.bits > hostkey.bytes * 8 ||
3348 servkey.bits > servkey.bytes * 8) {
2e85c969 3349 bombout(("SSH-1 public keys were badly formatted"));
0016d70b 3350 crStop(0);
3351 }
3352
51470298 3353 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 3354
3d88e64d 3355 s->rsabuf = snewn(s->len, unsigned char);
374330e2 3356
89ee5268 3357 /*
3358 * Verify the host key.
3359 */
3360 {
32874aea 3361 /*
3362 * First format the key into a string.
3363 */
3364 int len = rsastr_len(&hostkey);
3365 char fingerprint[100];
3d88e64d 3366 char *keystr = snewn(len, char);
32874aea 3367 rsastr_fmt(keystr, &hostkey);
3368 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3d9449a1 3369
3370 ssh_set_frozen(ssh, 1);
3371 s->dlgret = verify_ssh_host_key(ssh->frontend,
3372 ssh->savedhost, ssh->savedport,
3373 "rsa", keystr, fingerprint,
3374 ssh_dialog_callback, ssh);
32874aea 3375 sfree(keystr);
3d9449a1 3376 if (s->dlgret < 0) {
3377 do {
3378 crReturn(0);
3379 if (pktin) {
3380 bombout(("Unexpected data from server while waiting"
3381 " for user host key response"));
3382 crStop(0);
3383 }
3384 } while (pktin || inlen > 0);
3385 s->dlgret = ssh->user_response;
3386 }
3387 ssh_set_frozen(ssh, 0);
3388
3389 if (s->dlgret == 0) {
9e296bfa 3390 ssh_disconnect(ssh, "User aborted at host key verification",
3391 NULL, 0, TRUE);
2b3f6c19 3392 crStop(0);
3d9449a1 3393 }
32874aea 3394 }
3395
3396 for (i = 0; i < 32; i++) {
51470298 3397 s->rsabuf[i] = ssh->session_key[i];
374330e2 3398 if (i < 16)
51470298 3399 s->rsabuf[i] ^= s->session_id[i];
374330e2 3400 }
3401
3402 if (hostkey.bytes > servkey.bytes) {
0016d70b 3403 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3404 if (ret)
3405 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 3406 } else {
0016d70b 3407 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3408 if (ret)
3409 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3410 }
3411 if (!ret) {
2e85c969 3412 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
0016d70b 3413 crStop(0);
374330e2 3414 }
3415
c5e9c988 3416 logevent("Encrypted session key");
3417
ca20bfcf 3418 {
3419 int cipher_chosen = 0, warn = 0;
3420 char *cipher_string = NULL;
51470298 3421 int i;
ca20bfcf 3422 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4a693cfc 3423 int next_cipher = conf_get_int_int(ssh->conf,
3424 CONF_ssh_cipherlist, i);
ca20bfcf 3425 if (next_cipher == CIPHER_WARN) {
3426 /* If/when we choose a cipher, warn about it */
3427 warn = 1;
3428 } else if (next_cipher == CIPHER_AES) {
3429 /* XXX Probably don't need to mention this. */
2e85c969 3430 logevent("AES not supported in SSH-1, skipping");
ca20bfcf 3431 } else {
3432 switch (next_cipher) {
51470298 3433 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 3434 cipher_string = "3DES"; break;
51470298 3435 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 3436 cipher_string = "Blowfish"; break;
51470298 3437 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 3438 cipher_string = "single-DES"; break;
3439 }
51470298 3440 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 3441 cipher_chosen = 1;
3442 }
3443 }
3444 if (!cipher_chosen) {
51470298 3445 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2e85c969 3446 bombout(("Server violates SSH-1 protocol by not "
ca20bfcf 3447 "supporting 3DES encryption"));
3448 else
3449 /* shouldn't happen */
6b5cf8b4 3450 bombout(("No supported ciphers found"));
7ffdbc1a 3451 crStop(0);
a99a05c0 3452 }
ca20bfcf 3453
3454 /* Warn about chosen cipher if necessary. */
bb348ab1 3455 if (warn) {
3d9449a1 3456 ssh_set_frozen(ssh, 1);
3457 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3458 ssh_dialog_callback, ssh);
3459 if (s->dlgret < 0) {
3460 do {
3461 crReturn(0);
3462 if (pktin) {
3463 bombout(("Unexpected data from server while waiting"
3464 " for user response"));
3465 crStop(0);
3466 }
3467 } while (pktin || inlen > 0);
3468 s->dlgret = ssh->user_response;
3469 }
3470 ssh_set_frozen(ssh, 0);
3471 if (s->dlgret == 0) {
9e296bfa 3472 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3473 0, TRUE);
96ccde8b 3474 crStop(0);
3d9449a1 3475 }
bb348ab1 3476 }
bea1ef5f 3477 }
ca20bfcf 3478
51470298 3479 switch (s->cipher_type) {
32874aea 3480 case SSH_CIPHER_3DES:
3481 logevent("Using 3DES encryption");
3482 break;
3483 case SSH_CIPHER_DES:
3484 logevent("Using single-DES encryption");
3485 break;
3486 case SSH_CIPHER_BLOWFISH:
3487 logevent("Using Blowfish encryption");
3488 break;
c5e9c988 3489 }
bea1ef5f 3490
51470298 3491 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3492 PKT_CHAR, s->cipher_type,
32874aea 3493 PKT_DATA, cookie, 8,
51470298 3494 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3495 PKT_DATA, s->rsabuf, s->len,
3496 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3497
c5e9c988 3498 logevent("Trying to enable encryption...");
374330e2 3499
51470298 3500 sfree(s->rsabuf);
374330e2 3501
51470298 3502 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3503 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3504 &ssh_3des);
371e569c 3505 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3506 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3507 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3508
0183b242 3509 ssh->crcda_ctx = crcda_make_context();
3510 logevent("Installing CRC compensation attack detector");
3511
679539d7 3512 if (servkey.modulus) {
3513 sfree(servkey.modulus);
3514 servkey.modulus = NULL;
3515 }
3516 if (servkey.exponent) {
3517 sfree(servkey.exponent);
3518 servkey.exponent = NULL;
3519 }
3520 if (hostkey.modulus) {
3521 sfree(hostkey.modulus);
3522 hostkey.modulus = NULL;
3523 }
3524 if (hostkey.exponent) {
3525 sfree(hostkey.exponent);
3526 hostkey.exponent = NULL;
3527 }
ff3187f6 3528 crWaitUntil(pktin);
374330e2 3529
ff3187f6 3530 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3531 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3532 crStop(0);
8d5de777 3533 }
374330e2 3534
c5e9c988 3535 logevent("Successfully started encryption");
3536
edd0cb8a 3537 fflush(stdout); /* FIXME eh? */
374330e2 3538 {
4a693cfc 3539 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 3540 int ret; /* need not be kept over crReturn */
3541 s->cur_prompt = new_prompts(ssh->frontend);
3542 s->cur_prompt->to_server = TRUE;
3543 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 3544 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 3545 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3546 while (ret < 0) {
51470298 3547 ssh->send_ok = 1;
edd0cb8a 3548 crWaitUntil(!pktin);
3549 ret = get_userpass_input(s->cur_prompt, in, inlen);
3550 ssh->send_ok = 0;
3551 }
3552 if (!ret) {
3553 /*
3554 * Failed to get a username. Terminate.
3555 */
3556 free_prompts(s->cur_prompt);
3557 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3558 crStop(0);
32874aea 3559 }
4a693cfc 3560 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 3561 free_prompts(s->cur_prompt);
374330e2 3562 }
fb09bf1c 3563
4a693cfc 3564 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
c5e9c988 3565 {
4a693cfc 3566 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
c5e9c988 3567 logevent(userlog);
32874aea 3568 if (flags & FLAG_INTERACTIVE &&
3569 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
51470298 3570 c_write_str(ssh, userlog);
edd0cb8a 3571 c_write_str(ssh, "\r\n");
3c8e959b 3572 }
edd0cb8a 3573 sfree(userlog);
c5e9c988 3574 }
374330e2 3575 }
3576
ff3187f6 3577 crWaitUntil(pktin);
374330e2 3578
d5b2c841 3579 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
0df73905 3580 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3581 s->tried_publickey = s->tried_agent = 1;
0df73905 3582 } else {
51470298 3583 s->tried_publickey = s->tried_agent = 0;
0df73905 3584 }
51470298 3585 s->tis_auth_refused = s->ccard_auth_refused = 0;
edd0cb8a 3586 /*
3587 * Load the public half of any configured keyfile for later use.
3588 */
4a693cfc 3589 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 3590 if (!filename_is_null(s->keyfile)) {
edd0cb8a 3591 int keytype;
3592 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 3593 filename_to_str(s->keyfile));
3594 keytype = key_type(s->keyfile);
edd0cb8a 3595 if (keytype == SSH_KEYTYPE_SSH1) {
3596 const char *error;
4a693cfc 3597 if (rsakey_pubblob(s->keyfile,
edd0cb8a 3598 &s->publickey_blob, &s->publickey_bloblen,
3599 &s->publickey_comment, &error)) {
4a693cfc 3600 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
edd0cb8a 3601 NULL);
3602 } else {
3603 char *msgbuf;
3604 logeventf(ssh, "Unable to load private key (%s)", error);
3605 msgbuf = dupprintf("Unable to load private key file "
3606 "\"%.150s\" (%s)\r\n",
4a693cfc 3607 filename_to_str(s->keyfile),
edd0cb8a 3608 error);
3609 c_write_str(ssh, msgbuf);
3610 sfree(msgbuf);
3611 s->publickey_blob = NULL;
3612 }
3613 } else {
3614 char *msgbuf;
3615 logeventf(ssh, "Unable to use this key file (%s)",
3616 key_type_to_str(keytype));
3617 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3618 " (%s)\r\n",
4a693cfc 3619 filename_to_str(s->keyfile),
edd0cb8a 3620 key_type_to_str(keytype));
3621 c_write_str(ssh, msgbuf);
3622 sfree(msgbuf);
51470298 3623 s->publickey_blob = NULL;
edd0cb8a 3624 }
396778f1 3625 } else
51470298 3626 s->publickey_blob = NULL;
7cca0d81 3627
ff3187f6 3628 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3629 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3630
4a693cfc 3631 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
32874aea 3632 /*
3633 * Attempt RSA authentication using Pageant.
3634 */
32874aea 3635 void *r;
3636
51470298 3637 s->authed = FALSE;
3638 s->tried_agent = 1;
32874aea 3639 logevent("Pageant is running. Requesting keys.");
3640
3641 /* Request the keys held by the agent. */
51470298 3642 PUT_32BIT(s->request, 1);
3643 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3644 if (!agent_query(s->request, 5, &r, &s->responselen,
3645 ssh_agent_callback, ssh)) {
3646 do {
3647 crReturn(0);
ff3187f6 3648 if (pktin) {
839f10db 3649 bombout(("Unexpected data from server while waiting"
3650 " for agent response"));
3651 crStop(0);
3652 }
ff3187f6 3653 } while (pktin || inlen > 0);
839f10db 3654 r = ssh->agent_response;
3655 s->responselen = ssh->agent_response_len;
3656 }
51470298 3657 s->response = (unsigned char *) r;
3658 if (s->response && s->responselen >= 5 &&
3659 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3660 s->p = s->response + 5;
3661 s->nkeys = GET_32BIT(s->p);
3662 s->p += 4;
2e85c969 3663 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
51470298 3664 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
94cd7c3a 3665 unsigned char *pkblob = s->p;
51470298 3666 s->p += 4;
0016d70b 3667 {
3668 int n, ok = FALSE;
3669 do { /* do while (0) to make breaking easy */
3670 n = ssh1_read_bignum
3671 (s->p, s->responselen-(s->p-s->response),
3672 &s->key.exponent);
3673 if (n < 0)
3674 break;
3675 s->p += n;
3676 n = ssh1_read_bignum
3677 (s->p, s->responselen-(s->p-s->response),
3678 &s->key.modulus);
3679 if (n < 0)
3680 break;
3681 s->p += n;
3682 if (s->responselen - (s->p-s->response) < 4)
3683 break;
3684 s->commentlen = GET_32BIT(s->p);
3685 s->p += 4;
3686 if (s->responselen - (s->p-s->response) <
3687 s->commentlen)
3688 break;
3689 s->commentp = (char *)s->p;
3690 s->p += s->commentlen;
3691 ok = TRUE;
3692 } while (0);
3693 if (!ok) {
3694 logevent("Pageant key list packet was truncated");
3695 break;
3696 }
3697 }
94cd7c3a 3698 if (s->publickey_blob) {
3699 if (!memcmp(pkblob, s->publickey_blob,
3700 s->publickey_bloblen)) {
3701 logeventf(ssh, "Pageant key #%d matches "
3702 "configured key file", s->keyi);
3703 s->tried_publickey = 1;
3704 } else
3705 /* Skip non-configured key */
3706 continue;
3707 }
3708 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3709 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3710 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3711 crWaitUntil(pktin);
3712 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3713 logevent("Key refused");
3714 continue;
3715 }
3716 logevent("Received RSA challenge");
ff3187f6 3717 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3718 bombout(("Server's RSA challenge was badly formatted"));
3719 crStop(0);
3720 }
3721
32874aea 3722 {
3723 char *agentreq, *q, *ret;
2d466ffd 3724 void *vret;
32874aea 3725 int len, retlen;
3726 len = 1 + 4; /* message type, bit count */
51470298 3727 len += ssh1_bignum_length(s->key.exponent);
3728 len += ssh1_bignum_length(s->key.modulus);
3729 len += ssh1_bignum_length(s->challenge);
32874aea 3730 len += 16; /* session id */
3731 len += 4; /* response format */
3d88e64d 3732 agentreq = snewn(4 + len, char);
32874aea 3733 PUT_32BIT(agentreq, len);
3734 q = agentreq + 4;
3735 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3736 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3737 q += 4;
51470298 3738 q += ssh1_write_bignum(q, s->key.exponent);
3739 q += ssh1_write_bignum(q, s->key.modulus);
3740 q += ssh1_write_bignum(q, s->challenge);
3741 memcpy(q, s->session_id, 16);
32874aea 3742 q += 16;
3743 PUT_32BIT(q, 1); /* response format */
839f10db 3744 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3745 ssh_agent_callback, ssh)) {
3746 sfree(agentreq);
3747 do {
3748 crReturn(0);
ff3187f6 3749 if (pktin) {
839f10db 3750 bombout(("Unexpected data from server"
3751 " while waiting for agent"
3752 " response"));
3753 crStop(0);
3754 }
ff3187f6 3755 } while (pktin || inlen > 0);
839f10db 3756 vret = ssh->agent_response;
3757 retlen = ssh->agent_response_len;
3758 } else
3759 sfree(agentreq);
2d466ffd 3760 ret = vret;
32874aea 3761 if (ret) {
3762 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3763 logevent("Sending Pageant's response");
51470298 3764 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3765 PKT_DATA, ret + 5, 16,
3766 PKT_END);
3767 sfree(ret);
ff3187f6 3768 crWaitUntil(pktin);
3769 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3770 logevent
3771 ("Pageant's response accepted");
3772 if (flags & FLAG_VERBOSE) {
51470298 3773 c_write_str(ssh, "Authenticated using"
3774 " RSA key \"");
3775 c_write(ssh, s->commentp,
3776 s->commentlen);
3777 c_write_str(ssh, "\" from agent\r\n");
32874aea 3778 }
51470298 3779 s->authed = TRUE;
32874aea 3780 } else
3781 logevent
3782 ("Pageant's response not accepted");
3783 } else {
3784 logevent
3785 ("Pageant failed to answer challenge");
3786 sfree(ret);
3787 }
3788 } else {
3789 logevent("No reply received from Pageant");
3790 }
3791 }
51470298 3792 freebn(s->key.exponent);
3793 freebn(s->key.modulus);
3794 freebn(s->challenge);
3795 if (s->authed)
32874aea 3796 break;
3797 }
29b1d0b3 3798 sfree(s->response);
94cd7c3a 3799 if (s->publickey_blob && !s->tried_publickey)
3800 logevent("Configured key file not in Pageant");
5ff99b8e 3801 } else {
3802 logevent("Failed to get reply from Pageant");
3803 }
51470298 3804 if (s->authed)
32874aea 3805 break;
3806 }
edd0cb8a 3807 if (s->publickey_blob && !s->tried_publickey) {
3808 /*
3809 * Try public key authentication with the specified
3810 * key file.
3811 */
3812 int got_passphrase; /* need not be kept over crReturn */
3813 if (flags & FLAG_VERBOSE)
3814 c_write_str(ssh, "Trying public key authentication.\r\n");
4a693cfc 3815 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
edd0cb8a 3816 logeventf(ssh, "Trying public key \"%s\"",
4a693cfc 3817 filename_to_str(s->keyfile));
edd0cb8a 3818 s->tried_publickey = 1;
3819 got_passphrase = FALSE;
3820 while (!got_passphrase) {
3821 /*
3822 * Get a passphrase, if necessary.
3823 */
3824 char *passphrase = NULL; /* only written after crReturn */
3825 const char *error;
3826 if (!s->publickey_encrypted) {
3827 if (flags & FLAG_VERBOSE)
3828 c_write_str(ssh, "No passphrase required.\r\n");
3829 passphrase = NULL;
3830 } else {
3831 int ret; /* need not be kept over crReturn */
3832 s->cur_prompt = new_prompts(ssh->frontend);
3833 s->cur_prompt->to_server = FALSE;
3834 s->cur_prompt->name = dupstr("SSH key passphrase");
3835 add_prompt(s->cur_prompt,
3836 dupprintf("Passphrase for key \"%.100s\": ",
b61f81bc 3837 s->publickey_comment), FALSE);
edd0cb8a 3838 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3839 while (ret < 0) {
3840 ssh->send_ok = 1;
3841 crWaitUntil(!pktin);
3842 ret = get_userpass_input(s->cur_prompt, in, inlen);
3843 ssh->send_ok = 0;
3844 }
3845 if (!ret) {
3846 /* Failed to get a passphrase. Terminate. */
3847 free_prompts(s->cur_prompt);
3848 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3849 0, TRUE);
3850 crStop(0);
3851 }
3852 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3853 free_prompts(s->cur_prompt);
3854 }
3855 /*
3856 * Try decrypting key with passphrase.
3857 */
4a693cfc 3858 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3859 ret = loadrsakey(s->keyfile, &s->key, passphrase,
edd0cb8a 3860 &error);
3861 if (passphrase) {
dfb88efd 3862 smemclr(passphrase, strlen(passphrase));
edd0cb8a 3863 sfree(passphrase);
3864 }
3865 if (ret == 1) {
3866 /* Correct passphrase. */
3867 got_passphrase = TRUE;
3868 } else if (ret == 0) {
3869 c_write_str(ssh, "Couldn't load private key from ");
4a693cfc 3870 c_write_str(ssh, filename_to_str(s->keyfile));
edd0cb8a 3871 c_write_str(ssh, " (");
3872 c_write_str(ssh, error);
3873 c_write_str(ssh, ").\r\n");
3874 got_passphrase = FALSE;
3875 break; /* go and try something else */
3876 } else if (ret == -1) {
3877 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
edd0cb8a 3878 got_passphrase = FALSE;
3879 /* and try again */
43536490 3880 } else {
3881 assert(0 && "unexpected return from loadrsakey()");
edc23a8a 3882 got_passphrase = FALSE; /* placate optimisers */
edd0cb8a 3883 }
3884 }
3885
3886 if (got_passphrase) {
3887
3888 /*
3889 * Send a public key attempt.
3890 */
3891 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3892 PKT_BIGNUM, s->key.modulus, PKT_END);
3893
3894 crWaitUntil(pktin);
3895 if (pktin->type == SSH1_SMSG_FAILURE) {
3896 c_write_str(ssh, "Server refused our public key.\r\n");
7b575324 3897 continue; /* go and try something else */
edd0cb8a 3898 }
3899 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3900 bombout(("Bizarre response to offer of public key"));
3901 crStop(0);
3902 }
3903
3904 {
3905 int i;
3906 unsigned char buffer[32];
3907 Bignum challenge, response;
3908
3909 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3910 bombout(("Server's RSA challenge was badly formatted"));
3911 crStop(0);
3912 }
3913 response = rsadecrypt(challenge, &s->key);
3914 freebn(s->key.private_exponent);/* burn the evidence */
3915
3916 for (i = 0; i < 32; i++) {
3917 buffer[i] = bignum_byte(response, 31 - i);
3918 }
3919
3920 MD5Init(&md5c);
3921 MD5Update(&md5c, buffer, 32);
3922 MD5Update(&md5c, s->session_id, 16);
3923 MD5Final(buffer, &md5c);
3924
3925 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3926 PKT_DATA, buffer, 16, PKT_END);
3927
3928 freebn(challenge);
3929 freebn(response);
3930 }
3931
3932 crWaitUntil(pktin);
3933 if (pktin->type == SSH1_SMSG_FAILURE) {
3934 if (flags & FLAG_VERBOSE)
3935 c_write_str(ssh, "Failed to authenticate with"
3936 " our public key.\r\n");
7b575324 3937 continue; /* go and try something else */
edd0cb8a 3938 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3939 bombout(("Bizarre response to RSA authentication response"));
3940 crStop(0);
3941 }
3942
3943 break; /* we're through! */
3944 }
3945
3946 }
3947
3948 /*
3949 * Otherwise, try various forms of password-like authentication.
3950 */
3951 s->cur_prompt = new_prompts(ssh->frontend);
32874aea 3952
4a693cfc 3953 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 3954 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3955 !s->tis_auth_refused) {
3956 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3957 logevent("Requested TIS authentication");
51470298 3958 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3959 crWaitUntil(pktin);
3960 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3961 logevent("TIS authentication declined");
3962 if (flags & FLAG_INTERACTIVE)
51470298 3963 c_write_str(ssh, "TIS authentication refused.\r\n");
3964 s->tis_auth_refused = 1;
614a20a0 3965 continue;
32874aea 3966 } else {
0016d70b 3967 char *challenge;
3968 int challengelen;
edd0cb8a 3969 char *instr_suf, *prompt;
0016d70b 3970
ff3187f6 3971 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3972 if (!challenge) {
3973 bombout(("TIS challenge packet was badly formed"));
3974 crStop(0);
3975 }
32874aea 3976 logevent("Received TIS challenge");
edd0cb8a 3977 s->cur_prompt->to_server = TRUE;
3978 s->cur_prompt->name = dupstr("SSH TIS authentication");
614a20a0 3979 /* Prompt heuristic comes from OpenSSH */
edd0cb8a 3980 if (memchr(challenge, '\n', challengelen)) {
3981 instr_suf = dupstr("");
3982 prompt = dupprintf("%.*s", challengelen, challenge);
3983 } else {
3984 instr_suf = dupprintf("%.*s", challengelen, challenge);
3985 prompt = dupstr("Response: ");
3986 }
3987 s->cur_prompt->instruction =
3988 dupprintf("Using TIS authentication.%s%s",
3989 (*instr_suf) ? "\n" : "",
3990 instr_suf);
3991 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 3992 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 3993 sfree(instr_suf);
32874aea 3994 }
3995 }
4a693cfc 3996 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 3997 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3998 !s->ccard_auth_refused) {
3999 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 4000 logevent("Requested CryptoCard authentication");
51470298 4001 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 4002 crWaitUntil(pktin);
4003 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 4004 logevent("CryptoCard authentication declined");
51470298 4005 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4006 s->ccard_auth_refused = 1;
614a20a0 4007 continue;
32874aea 4008 } else {
0016d70b 4009 char *challenge;
4010 int challengelen;
edd0cb8a 4011 char *instr_suf, *prompt;
0016d70b 4012
ff3187f6 4013 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 4014 if (!challenge) {
4015 bombout(("CryptoCard challenge packet was badly formed"));
4016 crStop(0);
4017 }
32874aea 4018 logevent("Received CryptoCard challenge");
edd0cb8a 4019 s->cur_prompt->to_server = TRUE;
4020 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4021 s->cur_prompt->name_reqd = FALSE;
4022 /* Prompt heuristic comes from OpenSSH */
4023 if (memchr(challenge, '\n', challengelen)) {
4024 instr_suf = dupstr("");
4025 prompt = dupprintf("%.*s", challengelen, challenge);
4026 } else {
4027 instr_suf = dupprintf("%.*s", challengelen, challenge);
4028 prompt = dupstr("Response: ");
4029 }
4030 s->cur_prompt->instruction =
4031 dupprintf("Using CryptoCard authentication.%s%s",
4032 (*instr_suf) ? "\n" : "",
4033 instr_suf);
4034 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 4035 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 4036 sfree(instr_suf);
32874aea 4037 }
4038 }
51470298 4039 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
8f9e3231 4040 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4041 bombout(("No supported authentication methods available"));
4042 crStop(0);
4043 }
edd0cb8a 4044 s->cur_prompt->to_server = TRUE;
4045 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 4046 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4047 ssh->username, ssh->savedhost),
b61f81bc 4048 FALSE);
32874aea 4049 }
a52f067e 4050
614a20a0 4051 /*
4052 * Show password prompt, having first obtained it via a TIS
4053 * or CryptoCard exchange if we're doing TIS or CryptoCard
4054 * authentication.
4055 */
edd0cb8a 4056 {
4057 int ret; /* need not be kept over crReturn */
4058 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4059 while (ret < 0) {
4060 ssh->send_ok = 1;
4061 crWaitUntil(!pktin);
4062 ret = get_userpass_input(s->cur_prompt, in, inlen);
4063 ssh->send_ok = 0;
4064 }
4065 if (!ret) {
32874aea 4066 /*
edd0cb8a 4067 * Failed to get a password (for example
32874aea 4068 * because one was supplied on the command line
4069 * which has already failed to work). Terminate.
4070 */
edd0cb8a 4071 free_prompts(s->cur_prompt);
4072 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4073 crStop(0);
32874aea 4074 }
32874aea 4075 }
4076
edd0cb8a 4077 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 4078 /*
edd0cb8a 4079 * Defence against traffic analysis: we send a
4080 * whole bunch of packets containing strings of
4081 * different lengths. One of these strings is the
4082 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4083 * The others are all random data in
4084 * SSH1_MSG_IGNORE packets. This way a passive
4085 * listener can't tell which is the password, and
4086 * hence can't deduce the password length.
4087 *
4088 * Anybody with a password length greater than 16
4089 * bytes is going to have enough entropy in their
4090 * password that a listener won't find it _that_
4091 * much help to know how long it is. So what we'll
4092 * do is:
4093 *
4094 * - if password length < 16, we send 15 packets
4095 * containing string lengths 1 through 15
4096 *
4097 * - otherwise, we let N be the nearest multiple
4098 * of 8 below the password length, and send 8
4099 * packets containing string lengths N through
4100 * N+7. This won't obscure the order of
4101 * magnitude of the password length, but it will
4102 * introduce a bit of extra uncertainty.
4103 *
bf982899 4104 * A few servers can't deal with SSH1_MSG_IGNORE, at
4105 * least in this context. For these servers, we need
4106 * an alternative defence. We make use of the fact
4107 * that the password is interpreted as a C string:
4108 * so we can append a NUL, then some random data.
edd0cb8a 4109 *
bf982899 4110 * A few servers can deal with neither SSH1_MSG_IGNORE
4111 * here _nor_ a padded password string.
4112 * For these servers we are left with no defences
edd0cb8a 4113 * against password length sniffing.
32874aea 4114 */
bf982899 4115 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4116 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
32874aea 4117 /*
edd0cb8a 4118 * The server can deal with SSH1_MSG_IGNORE, so
4119 * we can use the primary defence.
32874aea 4120 */
edd0cb8a 4121 int bottom, top, pwlen, i;
4122 char *randomstr;
32874aea 4123
edd0cb8a 4124 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4125 if (pwlen < 16) {
4126 bottom = 0; /* zero length passwords are OK! :-) */
4127 top = 15;
4128 } else {
4129 bottom = pwlen & ~7;
4130 top = bottom + 7;
4131 }
32874aea 4132
edd0cb8a 4133 assert(pwlen >= bottom && pwlen <= top);
32874aea 4134
edd0cb8a 4135 randomstr = snewn(top + 1, char);
32874aea 4136
edd0cb8a 4137 for (i = bottom; i <= top; i++) {
4138 if (i == pwlen) {
4139 defer_packet(ssh, s->pwpkt_type,
4140 PKTT_PASSWORD, PKT_STR,
4141 s->cur_prompt->prompts[0]->result,
4142 PKTT_OTHER, PKT_END);
4143 } else {
4144 for (j = 0; j < i; j++) {
4145 do {
4146 randomstr[j] = random_byte();
4147 } while (randomstr[j] == '\0');
32874aea 4148 }
edd0cb8a 4149 randomstr[i] = '\0';
4150 defer_packet(ssh, SSH1_MSG_IGNORE,
4151 PKT_STR, randomstr, PKT_END);
32874aea 4152 }
edd0cb8a 4153 }
4154 logevent("Sending password with camouflage packets");
4155 ssh_pkt_defersend(ssh);
4156 sfree(randomstr);
4157 }
4158 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4159 /*
4160 * The server can't deal with SSH1_MSG_IGNORE
4161 * but can deal with padded passwords, so we
4162 * can use the secondary defence.
4163 */
4164 char string[64];
4165 char *ss;
4166 int len;
4167
4168 len = strlen(s->cur_prompt->prompts[0]->result);
4169 if (len < sizeof(string)) {
4170 ss = string;
4171 strcpy(string, s->cur_prompt->prompts[0]->result);
4172 len++; /* cover the zero byte */
4173 while (len < sizeof(string)) {
4174 string[len++] = (char) random_byte();
bd358db1 4175 }
bd358db1 4176 } else {
edd0cb8a 4177 ss = s->cur_prompt->prompts[0]->result;
32874aea 4178 }
edd0cb8a 4179 logevent("Sending length-padded password");
9a10ecf4 4180 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
edd0cb8a 4181 PKT_INT, len, PKT_DATA, ss, len,
4182 PKTT_OTHER, PKT_END);
4183 } else {
4184 /*
bf982899 4185 * The server is believed unable to cope with
4186 * any of our password camouflage methods.
edd0cb8a 4187 */
4188 int len;
4189 len = strlen(s->cur_prompt->prompts[0]->result);
4190 logevent("Sending unpadded password");
4191 send_packet(ssh, s->pwpkt_type,
4192 PKTT_PASSWORD, PKT_INT, len,
4193 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4194 PKTT_OTHER, PKT_END);
32874aea 4195 }
edd0cb8a 4196 } else {
4197 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4198 PKT_STR, s->cur_prompt->prompts[0]->result,
4199 PKTT_OTHER, PKT_END);
32874aea 4200 }
c5e9c988 4201 logevent("Sent password");
edd0cb8a 4202 free_prompts(s->cur_prompt);
ff3187f6 4203 crWaitUntil(pktin);
4204 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4205 if (flags & FLAG_VERBOSE)
51470298 4206 c_write_str(ssh, "Access denied\r\n");
c5e9c988 4207 logevent("Authentication refused");
ff3187f6 4208 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4209 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 4210 crStop(0);
374330e2 4211 }
4212 }
4213
edd0cb8a 4214 /* Clear up */
4215 if (s->publickey_blob) {
4216 sfree(s->publickey_blob);
4217 sfree(s->publickey_comment);
4218 }
4219
c5e9c988 4220 logevent("Authentication successful");
4221
fb09bf1c 4222 crFinish(1);
4223}
4224
bc06669b 4225static void ssh_channel_try_eof(struct ssh_channel *c)
4226{
4227 Ssh ssh = c->ssh;
4228 assert(c->pending_eof); /* precondition for calling us */
4229 if (c->halfopen)
4230 return; /* can't close: not even opened yet */
4231 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4232 return; /* can't send EOF: pending outgoing data */
4233
4234 if (ssh->version == 1) {
4235 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4236 PKT_END);
4237 c->closes |= CLOSES_SENT_EOF;
4238 } else {
4239 struct Packet *pktout;
4240 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4241 ssh2_pkt_adduint32(pktout, c->remoteid);
4242 ssh2_pkt_send(ssh, pktout);
4243 c->closes |= CLOSES_SENT_EOF;
4244 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes)) {
4245 /*
4246 * Also send MSG_CLOSE.
4247 */
4248 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4249 ssh2_pkt_adduint32(pktout, c->remoteid);
4250 ssh2_pkt_send(ssh, pktout);
4251 c->closes |= CLOSES_SENT_CLOSE;
4252 }
4253 }
4254 c->pending_eof = FALSE; /* we've sent it now */
4255}
4256
4257void sshfwd_write_eof(struct ssh_channel *c)
32874aea 4258{
51470298 4259 Ssh ssh = c->ssh;
4260
1ef619ae 4261 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4262 return;
36f94d1f 4263
bc06669b 4264 if (c->closes & CLOSES_SENT_EOF)
4265 return;
78280721 4266
bc06669b 4267 c->pending_eof = TRUE;
4268 ssh_channel_try_eof(c);
32874aea 4269}
4270
c6b41791 4271void sshfwd_unclean_close(struct ssh_channel *c)
4272{
4273 Ssh ssh = c->ssh;
4274 struct Packet *pktout;
4275
4276 if (ssh->state == SSH_STATE_CLOSED)
4277 return;
4278
96210393 4279 if (!(c->closes & CLOSES_SENT_CLOSE)) {
4280 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4281 ssh2_pkt_adduint32(pktout, c->remoteid);
4282 ssh2_pkt_send(ssh, pktout);
4283 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
4284 }
c6b41791 4285
c6b41791 4286 switch (c->type) {
4287 case CHAN_X11:
4288 x11_close(c->u.x11.s);
4289 break;
4290 case CHAN_SOCKDATA:
4291 case CHAN_SOCKDATA_DORMANT:
4292 pfd_close(c->u.pfd.s);
4293 break;
4294 }
4295 c->type = CHAN_ZOMBIE;
96210393 4296
c6b41791 4297 ssh2_channel_check_close(c);
4298}
4299
5471d09a 4300int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 4301{
51470298 4302 Ssh ssh = c->ssh;
4303
1ef619ae 4304 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4305 return 0;
36f94d1f 4306
51470298 4307 if (ssh->version == 1) {
4308 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 4309 PKT_INT, c->remoteid,
a2724fba 4310 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
9a10ecf4 4311 PKTT_OTHER, PKT_END);
5471d09a 4312 /*
2e85c969 4313 * In SSH-1 we can return 0 here - implying that forwarded
5471d09a 4314 * connections are never individually throttled - because
4315 * the only circumstance that can cause throttling will be
4316 * the whole SSH connection backing up, in which case
4317 * _everything_ will be throttled as a whole.
4318 */
4319 return 0;
783415f8 4320 } else {
32874aea 4321 ssh2_add_channel_data(c, buf, len);
5471d09a 4322 return ssh2_try_send(c);
4323 }
4324}
4325
4326void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4327{
51470298 4328 Ssh ssh = c->ssh;
ff68564b 4329 int buflimit;
51470298 4330
1ef619ae 4331 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4332 return;
36f94d1f 4333
51470298 4334 if (ssh->version == 1) {
ff68564b 4335 buflimit = SSH1_BUFFER_LIMIT;
5471d09a 4336 } else {
ff68564b 4337 buflimit = c->v.v2.locmaxwin;
4338 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4339 }
4340 if (c->throttling_conn && bufsize <= buflimit) {
4341 c->throttling_conn = 0;
4342 ssh_throttle_conn(ssh, -1);
783415f8 4343 }
9c964e85 4344}
4345
06fadff5 4346static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4347{
4348 struct queued_handler *qh = ssh->qhead;
4349
4350 assert(qh != NULL);
4351
4352 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4353
4354 if (qh->msg1 > 0) {
4355 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4356 ssh->packet_dispatch[qh->msg1] = NULL;
4357 }
4358 if (qh->msg2 > 0) {
4359 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4360 ssh->packet_dispatch[qh->msg2] = NULL;
4361 }
4362
4363 if (qh->next) {
4364 ssh->qhead = qh->next;
4365
4366 if (ssh->qhead->msg1 > 0) {
4367 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4368 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4369 }
4370 if (ssh->qhead->msg2 > 0) {
4371 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4372 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4373 }
4374 } else {
4375 ssh->qhead = ssh->qtail = NULL;
4376 ssh->packet_dispatch[pktin->type] = NULL;
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) {
4400 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4401 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4402 }
4403 if (qh->msg2 > 0) {
4404 assert(ssh->packet_dispatch[qh->msg2] == NULL);
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;
4962 case CHAN_SOCKDATA:
4963 if (c->u.pfd.s)
4964 x11_send_eof(c->u.pfd.s);
4965 else
4966 send_close = TRUE;
4967 case CHAN_AGENT:
4968 send_close = TRUE;
4969 }
51df0ab5 4970
bc06669b 4971 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
4972 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4973 PKT_END);
4974 c->closes |= CLOSES_SENT_EOF;
4975 }
4976 }
4977
4978 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
4979 !(c->closes & CLOSES_RCVD_CLOSE)) {
4980
4981 if (!(c->closes & CLOSES_SENT_EOF)) {
4982 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
4983 " for which we never sent CHANNEL_CLOSE\n", i));
4984 }
4985
4986 c->closes |= CLOSES_RCVD_CLOSE;
4987 }
4988
4989 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
4990 !(c->closes & CLOSES_SENT_CLOSE)) {
4991 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
4992 PKT_INT, c->remoteid, PKT_END);
4993 c->closes |= CLOSES_SENT_CLOSE;
4994 }
4995
4996 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
4997 ssh_channel_destroy(c);
51df0ab5 4998 } else {
4999 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5000 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5001 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5002 i));
5003 }
5004}
5005
5006static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5007{
5008 /* Data sent down one of our channels. */
5009 int i = ssh_pkt_getuint32(pktin);
5010 char *p;
6d44acc9 5011 int len;
51df0ab5 5012 struct ssh_channel *c;
5013
5014 ssh_pkt_getstring(pktin, &p, &len);
5015
5016 c = find234(ssh->channels, &i, ssh_channelfind);
5017 if (c) {
5018 int bufsize = 0;
5019 switch (c->type) {
5020 case CHAN_X11:
5021 bufsize = x11_send(c->u.x11.s, p, len);
5022 break;
5023 case CHAN_SOCKDATA:
5024 bufsize = pfd_send(c->u.pfd.s, p, len);
5025 break;
5026 case CHAN_AGENT:
5027 /* Data for an agent message. Buffer it. */
5028 while (len > 0) {
5029 if (c->u.a.lensofar < 4) {
62ddb51e 5030 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
51df0ab5 5031 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5032 l);
5033 p += l;
5034 len -= l;
5035 c->u.a.lensofar += l;
5036 }
5037 if (c->u.a.lensofar == 4) {
5038 c->u.a.totallen =
5039 4 + GET_32BIT(c->u.a.msglen);
5040 c->u.a.message = snewn(c->u.a.totallen,
5041 unsigned char);
5042 memcpy(c->u.a.message, c->u.a.msglen, 4);
5043 }
5044 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 5045 unsigned int l =
51df0ab5 5046 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 5047 (unsigned)len);
51df0ab5 5048 memcpy(c->u.a.message + c->u.a.lensofar, p,
5049 l);
5050 p += l;
5051 len -= l;
5052 c->u.a.lensofar += l;
5053 }
5054 if (c->u.a.lensofar == c->u.a.totallen) {
5055 void *reply;
5056 int replylen;
5057 if (agent_query(c->u.a.message,
5058 c->u.a.totallen,
5059 &reply, &replylen,
5060 ssh_agentf_callback, c))
5061 ssh_agentf_callback(c, reply, replylen);
5062 sfree(c->u.a.message);
5063 c->u.a.lensofar = 0;
5064 }
5065 }
5066 bufsize = 0; /* agent channels never back up */
5067 break;
5068 }
ff68564b 5069 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5070 c->throttling_conn = 1;
5071 ssh_throttle_conn(ssh, +1);
51df0ab5 5072 }
5073 }
5074}
5075
5076static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5077{
51df0ab5 5078 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 5079 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 5080 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5081 /*
5082 * In case `helpful' firewalls or proxies tack
5083 * extra human-readable text on the end of the
5084 * session which we might mistake for another
5085 * encrypted packet, we close the session once
5086 * we've sent EXIT_CONFIRMATION.
5087 */
9e296bfa 5088 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
51df0ab5 5089}
5090
c6ccd5c2 5091/* Helper function to deal with sending tty modes for REQUEST_PTY */
5092static void ssh1_send_ttymode(void *data, char *mode, char *val)
5093{
5094 struct Packet *pktout = (struct Packet *)data;
5095 int i = 0;
5096 unsigned int arg = 0;
5097 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5098 if (i == lenof(ssh_ttymodes)) return;
5099 switch (ssh_ttymodes[i].type) {
5100 case TTY_OP_CHAR:
5101 arg = ssh_tty_parse_specchar(val);
5102 break;
5103 case TTY_OP_BOOL:
5104 arg = ssh_tty_parse_boolean(val);
5105 break;
5106 }
5107 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5108 ssh2_pkt_addbyte(pktout, arg);
5109}
5110
5111
b09eaa88 5112static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5113 struct Packet *pktin)
32874aea 5114{
b09eaa88 5115 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 5116
51df0ab5 5117 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5118 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5119 ssh1_smsg_stdout_stderr_data;
5120
5121 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5122 ssh1_msg_channel_open_confirmation;
5123 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5124 ssh1_msg_channel_open_failure;
5125 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5126 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5127 ssh1_msg_channel_close;
5128 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5129 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5130
4a693cfc 5131 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
32874aea 5132 logevent("Requesting agent forwarding");
51470298 5133 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 5134 do {
5135 crReturnV;
ff3187f6 5136 } while (!pktin);
5137 if (pktin->type != SSH1_SMSG_SUCCESS
5138 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5139 bombout(("Protocol confusion"));
7ffdbc1a 5140 crStopV;
ff3187f6 5141 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5142 logevent("Agent forwarding refused");
5143 } else {
5144 logevent("Agent forwarding enabled");
51470298 5145 ssh->agentfwd_enabled = TRUE;
51df0ab5 5146 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 5147 }
dacbd0e8 5148 }
5149
4a693cfc 5150 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5151 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5152 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
32874aea 5153 logevent("Requesting X11 forwarding");
f68353be 5154 /*
5155 * Note that while we blank the X authentication data here, we don't
5156 * take any special action to blank the start of an X11 channel,
5157 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5158 * without having session blanking enabled is likely to leak your
5159 * cookie into the log.
5160 */
51470298 5161 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5162 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5163 PKT_STR, ssh->x11disp->remoteauthprotoname,
5164 PKTT_PASSWORD,
5165 PKT_STR, ssh->x11disp->remoteauthdatastring,
5166 PKTT_OTHER,
5167 PKT_INT, ssh->x11disp->screennum,
421d6835 5168 PKT_END);
32874aea 5169 } else {
51470298 5170 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5171 PKT_STR, ssh->x11disp->remoteauthprotoname,
5172 PKTT_PASSWORD,
5173 PKT_STR, ssh->x11disp->remoteauthdatastring,
5174 PKTT_OTHER,
5175 PKT_END);
32874aea 5176 }
5177 do {
5178 crReturnV;
ff3187f6 5179 } while (!pktin);
5180 if (pktin->type != SSH1_SMSG_SUCCESS
5181 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5182 bombout(("Protocol confusion"));
7ffdbc1a 5183 crStopV;
ff3187f6 5184 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5185 logevent("X11 forwarding refused");
5186 } else {
5187 logevent("X11 forwarding enabled");
51470298 5188 ssh->X11_fwd_enabled = TRUE;
51df0ab5 5189 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 5190 }
5191 }
5192
4a693cfc 5193 ssh_setup_portfwd(ssh, ssh->conf);
06fadff5 5194 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 5195
4a693cfc 5196 if (!conf_get_int(ssh->conf, CONF_nopty)) {
c6ccd5c2 5197 struct Packet *pkt;
a5dd8467 5198 /* Unpick the terminal-speed string. */
5199 /* XXX perhaps we should allow no speeds to be sent. */
db219738 5200 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4a693cfc 5201 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 5202 /* Send the pty request. */
c6ccd5c2 5203 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4a693cfc 5204 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
c6ccd5c2 5205 ssh_pkt_adduint32(pkt, ssh->term_height);
5206 ssh_pkt_adduint32(pkt, ssh->term_width);
5207 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5208 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4a693cfc 5209 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
c6ccd5c2 5210 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5211 ssh_pkt_adduint32(pkt, ssh->ispeed);
5212 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5213 ssh_pkt_adduint32(pkt, ssh->ospeed);
5214 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5215 s_wrpkt(ssh, pkt);
51470298 5216 ssh->state = SSH_STATE_INTERMED;
32874aea 5217 do {
5218 crReturnV;
ff3187f6 5219 } while (!pktin);
5220 if (pktin->type != SSH1_SMSG_SUCCESS
5221 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5222 bombout(("Protocol confusion"));
7ffdbc1a 5223 crStopV;
ff3187f6 5224 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5225 c_write_str(ssh, "Server refused to allocate pty\r\n");
5226 ssh->editing = ssh->echoing = 1;
4a202fc6 5227 } else {
5228 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5229 ssh->ospeed, ssh->ispeed);
5230 ssh->got_pty = TRUE;
5231 }
0965bee0 5232 } else {
51470298 5233 ssh->editing = ssh->echoing = 1;
374330e2 5234 }
5235
4a693cfc 5236 if (conf_get_int(ssh->conf, CONF_compression)) {
51470298 5237 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 5238 do {
5239 crReturnV;
ff3187f6 5240 } while (!pktin);
5241 if (pktin->type != SSH1_SMSG_SUCCESS
5242 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5243 bombout(("Protocol confusion"));
7ffdbc1a 5244 crStopV;
ff3187f6 5245 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5246 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 5247 }
4ba9b64b 5248 logevent("Started compression");
51470298 5249 ssh->v1_compressing = TRUE;
5366aed8 5250 ssh->cs_comp_ctx = zlib_compress_init();
5251 logevent("Initialised zlib (RFC1950) compression");
5252 ssh->sc_comp_ctx = zlib_decompress_init();
5253 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 5254 }
5255
fd5e5847 5256 /*
5257 * Start the shell or command.
5258 *
2e85c969 5259 * Special case: if the first-choice command is an SSH-2
fd5e5847 5260 * subsystem (hence not usable here) and the second choice
5261 * exists, we fall straight back to that.
5262 */
5263 {
4a693cfc 5264 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
fd5e5847 5265
4a693cfc 5266 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5267 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5268 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
51470298 5269 ssh->fallback_cmd = TRUE;
fd5e5847 5270 }
5271 if (*cmd)
51470298 5272 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 5273 else
51470298 5274 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 5275 logevent("Started session");
5276 }
374330e2 5277
51470298 5278 ssh->state = SSH_STATE_SESSION;
5279 if (ssh->size_needed)
5280 ssh_size(ssh, ssh->term_width, ssh->term_height);
5281 if (ssh->eof_needed)
5282 ssh_special(ssh, TS_EOF);
374330e2 5283
b9d7bcad 5284 if (ssh->ldisc)
5285 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5286 ssh->send_ok = 1;
5287 ssh->channels = newtree234(ssh_channelcmp);
374330e2 5288 while (1) {
d74d141c 5289
51df0ab5 5290 /*
5291 * By this point, most incoming packets are already being
5292 * handled by the dispatch table, and we need only pay
5293 * attention to the unusual ones.
5294 */
0357890f 5295
51df0ab5 5296 crReturnV;
5297 if (pktin) {
5298 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 5299 /* may be from EXEC_SHELL on some servers */
ff3187f6 5300 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 5301 /* may be from EXEC_SHELL on some servers
374330e2 5302 * if no pty is available or in other odd cases. Ignore */
374330e2 5303 } else {
ff3187f6 5304 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 5305 crStopV;
374330e2 5306 }
5307 } else {
8df7a775 5308 while (inlen > 0) {
5309 int len = min(inlen, 512);
a2724fba 5310 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5311 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
9a10ecf4 5312 PKTT_OTHER, PKT_END);
8df7a775 5313 in += len;
5314 inlen -= len;
5315 }
374330e2 5316 }
5317 }
5318
5319 crFinishV;
5320}
5321
5322/*
2e85c969 5323 * Handle the top-level SSH-2 protocol.
b09eaa88 5324 */
5325static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5326{
fb983202 5327 char *msg;
b09eaa88 5328 int msglen;
5329
5330 ssh_pkt_getstring(pktin, &msg, &msglen);
fb983202 5331 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 5332}
5333
5334static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5335{
5336 /* log reason code in disconnect message */
5337 char *msg;
5338 int msglen;
5339
5340 ssh_pkt_getstring(pktin, &msg, &msglen);
5341 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5342}
5343
409bfa77 5344static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
b09eaa88 5345{
5346 /* Do nothing, because we're ignoring it! Duhh. */
5347}
5348
5349static void ssh1_protocol_setup(Ssh ssh)
5350{
5351 int i;
5352
5353 /*
5354 * Most messages are handled by the coroutines.
5355 */
5356 for (i = 0; i < 256; i++)
5357 ssh->packet_dispatch[i] = NULL;
5358
5359 /*
5360 * These special message types we install handlers for.
5361 */
5362 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5363 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5364 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5365}
5366
1c1a7262 5367static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
b09eaa88 5368 struct Packet *pktin)
5369{
1c1a7262 5370 unsigned char *in=(unsigned char*)vin;
b09eaa88 5371 if (ssh->state == SSH_STATE_CLOSED)
5372 return;
5373
5374 if (pktin && ssh->packet_dispatch[pktin->type]) {
5375 ssh->packet_dispatch[pktin->type](ssh, pktin);
5376 return;
5377 }
5378
5379 if (!ssh->protocol_initial_phase_done) {
5380 if (do_ssh1_login(ssh, in, inlen, pktin))
5381 ssh->protocol_initial_phase_done = TRUE;
5382 else
5383 return;
5384 }
5385
5386 do_ssh1_connection(ssh, in, inlen, pktin);
5387}
5388
5389/*
e5574168 5390 * Utility routine for decoding comma-separated strings in KEXINIT.
5391 */
32874aea 5392static int in_commasep_string(char *needle, char *haystack, int haylen)
5393{
57356d63 5394 int needlen;
5395 if (!needle || !haystack) /* protect against null pointers */
5396 return 0;
5397 needlen = strlen(needle);
e5574168 5398 while (1) {
32874aea 5399 /*
5400 * Is it at the start of the string?
5401 */
5402 if (haylen >= needlen && /* haystack is long enough */
5403 !memcmp(needle, haystack, needlen) && /* initial match */
5404 (haylen == needlen || haystack[needlen] == ',')
5405 /* either , or EOS follows */
5406 )
5407 return 1;
5408 /*
5409 * If not, search for the next comma and resume after that.
5410 * If no comma found, terminate.
5411 */
5412 while (haylen > 0 && *haystack != ',')
5413 haylen--, haystack++;
5414 if (haylen == 0)
5415 return 0;
5416 haylen--, haystack++; /* skip over comma itself */
e5574168 5417 }
5418}
5419
5420/*
b59743d5 5421 * Similar routine for checking whether we have the first string in a list.
5422 */
5423static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5424{
5425 int needlen;
5426 if (!needle || !haystack) /* protect against null pointers */
5427 return 0;
5428 needlen = strlen(needle);
5429 /*
5430 * Is it at the start of the string?
5431 */
5432 if (haylen >= needlen && /* haystack is long enough */
5433 !memcmp(needle, haystack, needlen) && /* initial match */
5434 (haylen == needlen || haystack[needlen] == ',')
5435 /* either , or EOS follows */
5436 )
5437 return 1;
5438 return 0;
5439}
5440
5441
5442/*
2e85c969 5443 * SSH-2 key creation method.
754c0df9 5444 * (Currently assumes 2 lots of any hash are sufficient to generate
5445 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
d39f364a 5446 */
754c0df9 5447#define SSH2_MKKEY_ITERS (2)
b672f405 5448static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
d8baa528 5449 unsigned char *keyspace)
32874aea 5450{
b672f405 5451 const struct ssh_hash *h = ssh->kex->hash;
5452 void *s;
5453 /* First hlen bytes. */
5454 s = h->init();
51470298 5455 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5456 hash_mpint(h, s, K);
5457 h->bytes(s, H, h->hlen);
5458 h->bytes(s, &chr, 1);
5459 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5460 h->final(s, keyspace);
5461 /* Next hlen bytes. */
5462 s = h->init();
51470298 5463 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5464 hash_mpint(h, s, K);
5465 h->bytes(s, H, h->hlen);
5466 h->bytes(s, keyspace, h->hlen);
5467 h->final(s, keyspace + h->hlen);
d39f364a 5468}
5469
5470/*
2e85c969 5471 * Handle the SSH-2 transport layer.
e5574168 5472 */
1c1a7262 5473static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
ff3187f6 5474 struct Packet *pktin)
e5574168 5475{
1c1a7262 5476 unsigned char *in = (unsigned char *)vin;
51470298 5477 struct do_ssh2_transport_state {
30919997 5478 int crLine;
4763c1c2 5479 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
51470298 5480 Bignum p, g, e, f, K;
3dc9a6a7 5481 void *our_kexinit;
5482 int our_kexinitlen;
51470298 5483 int kex_init_value, kex_reply_value;
5484 const struct ssh_mac **maclist;
5485 int nmacs;
5486 const struct ssh2_cipher *cscipher_tobe;
5487 const struct ssh2_cipher *sccipher_tobe;
5488 const struct ssh_mac *csmac_tobe;
5489 const struct ssh_mac *scmac_tobe;
5490 const struct ssh_compress *cscomp_tobe;
5491 const struct ssh_compress *sccomp_tobe;
fae1a71b 5492 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5493 int hostkeylen, siglen, rsakeylen;
51470298 5494 void *hkey; /* actual host key */
fae1a71b 5495 void *rsakey; /* for RSA kex */
754c0df9 5496 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
83e7d008 5497 int n_preferred_kex;
34557659 5498 const struct ssh_kexes *preferred_kex[KEX_MAX];
51470298 5499 int n_preferred_ciphers;
5500 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5501 const struct ssh_compress *preferred_comp;
ab18ccff 5502 int userauth_succeeded; /* for delayed compression */
5503 int pending_compression;
e13bba36 5504 int got_session_id, activated_authconn;
ff3187f6 5505 struct Packet *pktout;
3d9449a1 5506 int dlgret;
5507 int guessok;
4763c1c2 5508 int ignorepkt;
51470298 5509 };
5510 crState(do_ssh2_transport_state);
5511
30919997 5512 crBeginState;
51470298 5513
5514 s->cscipher_tobe = s->sccipher_tobe = NULL;
5515 s->csmac_tobe = s->scmac_tobe = NULL;
5516 s->cscomp_tobe = s->sccomp_tobe = NULL;
5517
e13bba36 5518 s->got_session_id = s->activated_authconn = FALSE;
ab18ccff 5519 s->userauth_succeeded = FALSE;
5520 s->pending_compression = FALSE;
e5574168 5521
e13bba36 5522 /*
5523 * Be prepared to work around the buggy MAC problem.
5524 */
5525 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5526 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5527 else
5528 s->maclist = macs, s->nmacs = lenof(macs);
5529
5530 begin_key_exchange:
acab36bc 5531 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
51470298 5532 {
e13bba36 5533 int i, j, commalist_started;
5534
51470298 5535 /*
83e7d008 5536 * Set up the preferred key exchange. (NULL => warn below here)
5537 */
5538 s->n_preferred_kex = 0;
5539 for (i = 0; i < KEX_MAX; i++) {
4a693cfc 5540 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
83e7d008 5541 case KEX_DHGEX:
5542 s->preferred_kex[s->n_preferred_kex++] =
5543 &ssh_diffiehellman_gex;
5544 break;
5545 case KEX_DHGROUP14:
5546 s->preferred_kex[s->n_preferred_kex++] =
5547 &ssh_diffiehellman_group14;
5548 break;
5549 case KEX_DHGROUP1:
5550 s->preferred_kex[s->n_preferred_kex++] =
5551 &ssh_diffiehellman_group1;
5552 break;
fae1a71b 5553 case KEX_RSA:
5554 s->preferred_kex[s->n_preferred_kex++] =
5555 &ssh_rsa_kex;
5556 break;
754c0df9 5557 case KEX_WARN:
83e7d008 5558 /* Flag for later. Don't bother if it's the last in
5559 * the list. */
5560 if (i < KEX_MAX - 1) {
5561 s->preferred_kex[s->n_preferred_kex++] = NULL;
5562 }
5563 break;
5564 }
5565 }
83e7d008 5566
83e7d008 5567 /*
51470298 5568 * Set up the preferred ciphers. (NULL => warn below here)
5569 */
5570 s->n_preferred_ciphers = 0;
5571 for (i = 0; i < CIPHER_MAX; i++) {
4a693cfc 5572 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
51470298 5573 case CIPHER_BLOWFISH:
5574 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5575 break;
5576 case CIPHER_DES:
4a693cfc 5577 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
51470298 5578 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5579 }
5580 break;
5581 case CIPHER_3DES:
5582 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5583 break;
5584 case CIPHER_AES:
5585 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5586 break;
a2add208 5587 case CIPHER_ARCFOUR:
5588 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5589 break;
51470298 5590 case CIPHER_WARN:
5591 /* Flag for later. Don't bother if it's the last in
5592 * the list. */
5593 if (i < CIPHER_MAX - 1) {
5594 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5595 }
5596 break;
ca20bfcf 5597 }
ca20bfcf 5598 }
7591b9ff 5599
e13bba36 5600 /*
5601 * Set up preferred compression.
5602 */
4a693cfc 5603 if (conf_get_int(ssh->conf, CONF_compression))
e13bba36 5604 s->preferred_comp = &ssh_zlib;
5605 else
5606 s->preferred_comp = &ssh_comp_none;
51470298 5607
5608 /*
590f6a5f 5609 * Enable queueing of outgoing auth- or connection-layer
5610 * packets while we are in the middle of a key exchange.
5611 */
5612 ssh->queueing = TRUE;
5613
5614 /*
9442dd57 5615 * Flag that KEX is in progress.
5616 */
5617 ssh->kex_in_progress = TRUE;
5618
5619 /*
51470298 5620 * Construct and send our key exchange packet.
5621 */
ff3187f6 5622 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 5623 for (i = 0; i < 16; i++)
ff3187f6 5624 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 5625 /* List key exchange algorithms. */
ff3187f6 5626 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5627 commalist_started = 0;
5628 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5629 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5630 if (!k) continue; /* warning flag */
34557659 5631 for (j = 0; j < k->nkexes; j++) {
5632 if (commalist_started)
5633 ssh2_pkt_addstring_str(s->pktout, ",");
5634 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5635 commalist_started = 1;
5636 }
32874aea 5637 }
51470298 5638 /* List server host key algorithms. */
ff3187f6 5639 ssh2_pkt_addstring_start(s->pktout);
51470298 5640 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 5641 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 5642 if (i < lenof(hostkey_algs) - 1)
ff3187f6 5643 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 5644 }
51470298 5645 /* List client->server encryption algorithms. */
ff3187f6 5646 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5647 commalist_started = 0;
51470298 5648 for (i = 0; i < s->n_preferred_ciphers; i++) {
5649 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5650 if (!c) continue; /* warning flag */
5651 for (j = 0; j < c->nciphers; j++) {
83e7d008 5652 if (commalist_started)
ff3187f6 5653 ssh2_pkt_addstring_str(s->pktout, ",");
5654 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5655 commalist_started = 1;
51470298 5656 }
5657 }
5658 /* List server->client encryption algorithms. */
ff3187f6 5659 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5660 commalist_started = 0;
51470298 5661 for (i = 0; i < s->n_preferred_ciphers; i++) {
5662 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5663 if (!c) continue; /* warning flag */
5664 for (j = 0; j < c->nciphers; j++) {
83e7d008 5665 if (commalist_started)
ff3187f6 5666 ssh2_pkt_addstring_str(s->pktout, ",");
5667 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5668 commalist_started = 1;
51470298 5669 }
5670 }
5671 /* List client->server MAC algorithms. */
ff3187f6 5672 ssh2_pkt_addstring_start(s->pktout);
51470298 5673 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5674 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5675 if (i < s->nmacs - 1)
ff3187f6 5676 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5677 }
5678 /* List server->client MAC algorithms. */
ff3187f6 5679 ssh2_pkt_addstring_start(s->pktout);
51470298 5680 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5681 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5682 if (i < s->nmacs - 1)
ff3187f6 5683 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5684 }
ab18ccff 5685 /* List client->server compression algorithms,
5686 * then server->client compression algorithms. (We use the
5687 * same set twice.) */
5688 for (j = 0; j < 2; j++) {
5689 ssh2_pkt_addstring_start(s->pktout);
5690 assert(lenof(compressions) > 1);
5691 /* Prefer non-delayed versions */
5692 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5693 /* We don't even list delayed versions of algorithms until
5694 * they're allowed to be used, to avoid a race. See the end of
5695 * this function. */
5696 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
ff3187f6 5697 ssh2_pkt_addstring_str(s->pktout, ",");
ab18ccff 5698 ssh2_pkt_addstring_str(s->pktout,
5699 s->preferred_comp->delayed_name);
f6e0abe2 5700 }
ab18ccff 5701 for (i = 0; i < lenof(compressions); i++) {
5702 const struct ssh_compress *c = compressions[i];
5703 if (c != s->preferred_comp) {
5704 ssh2_pkt_addstring_str(s->pktout, ",");
5705 ssh2_pkt_addstring_str(s->pktout, c->name);
5706 if (s->userauth_succeeded && c->delayed_name) {
5707 ssh2_pkt_addstring_str(s->pktout, ",");
5708 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5709 }
5710 }
f6e0abe2 5711 }
51470298 5712 }
5713 /* List client->server languages. Empty list. */
ff3187f6 5714 ssh2_pkt_addstring_start(s->pktout);
51470298 5715 /* List server->client languages. Empty list. */
ff3187f6 5716 ssh2_pkt_addstring_start(s->pktout);
51470298 5717 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5718 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5719 /* Reserved. */
ff3187f6 5720 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5721 }
0db56f73 5722
3dc9a6a7 5723 s->our_kexinitlen = s->pktout->length - 5;
5724 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5725 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
0db56f73 5726
590f6a5f 5727 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5728
ff3187f6 5729 if (!pktin)
5730 crWaitUntil(pktin);
e5574168 5731
5732 /*
5733 * Now examine the other side's KEXINIT to see what we're up
5734 * to.
5735 */
51470298 5736 {
4763c1c2 5737 char *str, *preferred;
3d9449a1 5738 int i, j, len;
51470298 5739
ff3187f6 5740 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5741 bombout(("expected key exchange packet from server"));
7ffdbc1a 5742 crStop(0);
32874aea 5743 }
51470298 5744 ssh->kex = NULL;
5745 ssh->hostkey = NULL;
5746 s->cscipher_tobe = NULL;
5747 s->sccipher_tobe = NULL;
5748 s->csmac_tobe = NULL;
5749 s->scmac_tobe = NULL;
5750 s->cscomp_tobe = NULL;
5751 s->sccomp_tobe = NULL;
4763c1c2 5752 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5753
ff3187f6 5754 pktin->savedpos += 16; /* skip garbage cookie */
5755 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4763c1c2 5756
5757 preferred = NULL;
83e7d008 5758 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5759 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5760 if (!k) {
4763c1c2 5761 s->warn_kex = TRUE;
5762 } else {
34557659 5763 for (j = 0; j < k->nkexes; j++) {
5764 if (!preferred) preferred = k->list[j]->name;
5765 if (in_commasep_string(k->list[j]->name, str, len)) {
5766 ssh->kex = k->list[j];
5767 break;
5768 }
5769 }
83e7d008 5770 }
4763c1c2 5771 if (ssh->kex)
51470298 5772 break;
32874aea 5773 }
83e7d008 5774 if (!ssh->kex) {
5775 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5776 str ? str : "(null)"));
5777 crStop(0);
5778 }
b59743d5 5779 /*
5780 * Note that the server's guess is considered wrong if it doesn't match
5781 * the first algorithm in our list, even if it's still the algorithm
5782 * we end up using.
5783 */
4763c1c2 5784 s->guessok = first_in_commasep_string(preferred, str, len);
ff3187f6 5785 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5786 for (i = 0; i < lenof(hostkey_algs); i++) {
5787 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5788 ssh->hostkey = hostkey_algs[i];
5789 break;
5790 }
5791 }
fc40b431 5792 if (!ssh->hostkey) {
5793 bombout(("Couldn't agree a host key algorithm (available: %s)",
5794 str ? str : "(null)"));
5795 crStop(0);
5796 }
5797
3d9449a1 5798 s->guessok = s->guessok &&
b59743d5 5799 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5800 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5801 for (i = 0; i < s->n_preferred_ciphers; i++) {
5802 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5803 if (!c) {
4763c1c2 5804 s->warn_cscipher = TRUE;
51470298 5805 } else {
5806 for (j = 0; j < c->nciphers; j++) {
5807 if (in_commasep_string(c->list[j]->name, str, len)) {
5808 s->cscipher_tobe = c->list[j];
5809 break;
5810 }
ca20bfcf 5811 }
32874aea 5812 }
4763c1c2 5813 if (s->cscipher_tobe)
51470298 5814 break;
32874aea 5815 }
51470298 5816 if (!s->cscipher_tobe) {
6b5cf8b4 5817 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5818 str ? str : "(null)"));
7ffdbc1a 5819 crStop(0);
ca20bfcf 5820 }
0ef8f407 5821
ff3187f6 5822 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5823 for (i = 0; i < s->n_preferred_ciphers; i++) {
5824 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5825 if (!c) {
4763c1c2 5826 s->warn_sccipher = TRUE;
51470298 5827 } else {
5828 for (j = 0; j < c->nciphers; j++) {
5829 if (in_commasep_string(c->list[j]->name, str, len)) {
5830 s->sccipher_tobe = c->list[j];
5831 break;
5832 }
ca20bfcf 5833 }
32874aea 5834 }
4763c1c2 5835 if (s->sccipher_tobe)
51470298 5836 break;
32874aea 5837 }
51470298 5838 if (!s->sccipher_tobe) {
6b5cf8b4 5839 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5840 str ? str : "(null)"));
7ffdbc1a 5841 crStop(0);
ca20bfcf 5842 }
0ef8f407 5843
ff3187f6 5844 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5845 for (i = 0; i < s->nmacs; i++) {
5846 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5847 s->csmac_tobe = s->maclist[i];
5848 break;
5849 }
32874aea 5850 }
ff3187f6 5851 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5852 for (i = 0; i < s->nmacs; i++) {
5853 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5854 s->scmac_tobe = s->maclist[i];
5855 break;
5856 }
32874aea 5857 }
ff3187f6 5858 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5859 for (i = 0; i < lenof(compressions) + 1; i++) {
5860 const struct ssh_compress *c =
5861 i == 0 ? s->preferred_comp : compressions[i - 1];
5862 if (in_commasep_string(c->name, str, len)) {
5863 s->cscomp_tobe = c;
5864 break;
ab18ccff 5865 } else if (in_commasep_string(c->delayed_name, str, len)) {
5866 if (s->userauth_succeeded) {
5867 s->cscomp_tobe = c;
5868 break;
5869 } else {
5870 s->pending_compression = TRUE; /* try this later */
5871 }
51470298 5872 }
32874aea 5873 }
ff3187f6 5874 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5875 for (i = 0; i < lenof(compressions) + 1; i++) {
5876 const struct ssh_compress *c =
5877 i == 0 ? s->preferred_comp : compressions[i - 1];
5878 if (in_commasep_string(c->name, str, len)) {
5879 s->sccomp_tobe = c;
5880 break;
ab18ccff 5881 } else if (in_commasep_string(c->delayed_name, str, len)) {
5882 if (s->userauth_succeeded) {
5883 s->sccomp_tobe = c;
5884 break;
5885 } else {
5886 s->pending_compression = TRUE; /* try this later */
5887 }
51470298 5888 }
32874aea 5889 }
ab18ccff 5890 if (s->pending_compression) {
5891 logevent("Server supports delayed compression; "
5892 "will try this later");
5893 }
b59743d5 5894 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5895 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
4763c1c2 5896 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5897
5898 if (s->warn_kex) {
5899 ssh_set_frozen(ssh, 1);
5900 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5901 ssh->kex->name,
5902 ssh_dialog_callback, ssh);
5903 if (s->dlgret < 0) {
5904 do {
5905 crReturn(0);
5906 if (pktin) {
5907 bombout(("Unexpected data from server while"
5908 " waiting for user response"));
5909 crStop(0);
5910 }
5911 } while (pktin || inlen > 0);
5912 s->dlgret = ssh->user_response;
5913 }
5914 ssh_set_frozen(ssh, 0);
5915 if (s->dlgret == 0) {
9e296bfa 5916 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5917 0, TRUE);
a5a6f839 5918 crStop(0);
4763c1c2 5919 }
5920 }
5921
5922 if (s->warn_cscipher) {
5923 ssh_set_frozen(ssh, 1);
5924 s->dlgret = askalg(ssh->frontend,
5925 "client-to-server cipher",
5926 s->cscipher_tobe->name,
5927 ssh_dialog_callback, ssh);
5928 if (s->dlgret < 0) {
5929 do {
5930 crReturn(0);
5931 if (pktin) {
5932 bombout(("Unexpected data from server while"
5933 " waiting for user response"));
5934 crStop(0);
5935 }
5936 } while (pktin || inlen > 0);
5937 s->dlgret = ssh->user_response;
5938 }
5939 ssh_set_frozen(ssh, 0);
5940 if (s->dlgret == 0) {
9e296bfa 5941 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5942 0, TRUE);
a5a6f839 5943 crStop(0);
4763c1c2 5944 }
5945 }
5946
5947 if (s->warn_sccipher) {
5948 ssh_set_frozen(ssh, 1);
5949 s->dlgret = askalg(ssh->frontend,
5950 "server-to-client cipher",
5951 s->sccipher_tobe->name,
5952 ssh_dialog_callback, ssh);
5953 if (s->dlgret < 0) {
5954 do {
5955 crReturn(0);
5956 if (pktin) {
5957 bombout(("Unexpected data from server while"
5958 " waiting for user response"));
5959 crStop(0);
5960 }
5961 } while (pktin || inlen > 0);
5962 s->dlgret = ssh->user_response;
5963 }
5964 ssh_set_frozen(ssh, 0);
5965 if (s->dlgret == 0) {
9e296bfa 5966 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5967 0, TRUE);
a5a6f839 5968 crStop(0);
4763c1c2 5969 }
5970 }
5971
b672f405 5972 ssh->exhash = ssh->kex->hash->init();
5973 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5974 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5975 hash_string(ssh->kex->hash, ssh->exhash,
5976 s->our_kexinit, s->our_kexinitlen);
3dc9a6a7 5977 sfree(s->our_kexinit);
5978 if (pktin->length > 5)
b672f405 5979 hash_string(ssh->kex->hash, ssh->exhash,
5980 pktin->data + 5, pktin->length - 5);
3dc9a6a7 5981
4763c1c2 5982 if (s->ignorepkt) /* first_kex_packet_follows */
b59743d5 5983 crWaitUntil(pktin); /* Ignore packet */
e5574168 5984 }
e5574168 5985
fae1a71b 5986 if (ssh->kex->main_type == KEXTYPE_DH) {
30774ba3 5987 /*
5988 * Work out the number of bits of key we will need from the
5989 * key exchange. We start with the maximum key length of
5990 * either cipher...
5991 */
5992 {
5993 int csbits, scbits;
5994
5995 csbits = s->cscipher_tobe->keylen;
5996 scbits = s->sccipher_tobe->keylen;
5997 s->nbits = (csbits > scbits ? csbits : scbits);
5998 }
5999 /* The keys only have hlen-bit entropy, since they're based on
6000 * a hash. So cap the key size at hlen bits. */
6001 if (s->nbits > ssh->kex->hash->hlen * 8)
6002 s->nbits = ssh->kex->hash->hlen * 8;
6003
6004 /*
6005 * If we're doing Diffie-Hellman group exchange, start by
6006 * requesting a group.
6007 */
6008 if (!ssh->kex->pdata) {
6009 logevent("Doing Diffie-Hellman group exchange");
acab36bc 6010 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
30774ba3 6011 /*
6012 * Work out how big a DH group we will need to allow that
6013 * much data.
6014 */
6015 s->pbits = 512 << ((s->nbits - 1) / 64);
6016 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6017 ssh2_pkt_adduint32(s->pktout, s->pbits);
6018 ssh2_pkt_send_noqueue(ssh, s->pktout);
6019
6020 crWaitUntil(pktin);
6021 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6022 bombout(("expected key exchange group packet from server"));
6023 crStop(0);
6024 }
6025 s->p = ssh2_pkt_getmp(pktin);
6026 s->g = ssh2_pkt_getmp(pktin);
6027 if (!s->p || !s->g) {
6028 bombout(("unable to read mp-ints from incoming group packet"));
6029 crStop(0);
6030 }
6031 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6032 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6033 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6034 } else {
acab36bc 6035 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
30774ba3 6036 ssh->kex_ctx = dh_setup_group(ssh->kex);
6037 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6038 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6039 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6040 ssh->kex->groupname);
6041 }
e5574168 6042
30774ba3 6043 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6044 ssh->kex->hash->text_name);
6045 /*
6046 * Now generate and send e for Diffie-Hellman.
6047 */
6048 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6049 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6050 s->pktout = ssh2_pkt_init(s->kex_init_value);
6051 ssh2_pkt_addmp(s->pktout, s->e);
6052 ssh2_pkt_send_noqueue(ssh, s->pktout);
6053
6054 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6055 crWaitUntil(pktin);
6056 if (pktin->type != s->kex_reply_value) {
6057 bombout(("expected key exchange reply packet from server"));
6058 crStop(0);
6059 }
6060 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6061 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6062 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6063 s->f = ssh2_pkt_getmp(pktin);
6064 if (!s->f) {
6065 bombout(("unable to parse key exchange reply packet"));
6066 crStop(0);
6067 }
6068 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 6069
30774ba3 6070 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 6071
30774ba3 6072 /* We assume everything from now on will be quick, and it might
6073 * involve user interaction. */
6074 set_busy_status(ssh->frontend, BUSY_NOT);
755e0524 6075
30774ba3 6076 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6077 if (!ssh->kex->pdata) {
6078 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6079 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6080 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6081 }
6082 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6083 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6084
6085 dh_cleanup(ssh->kex_ctx);
6086 freebn(s->f);
6087 if (!ssh->kex->pdata) {
6088 freebn(s->g);
6089 freebn(s->p);
6090 }
fae1a71b 6091 } else {
6092 logeventf(ssh, "Doing RSA key exchange with hash %s",
6093 ssh->kex->hash->text_name);
acab36bc 6094 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
fae1a71b 6095 /*
6096 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6097 * from the server.
6098 */
6099 crWaitUntil(pktin);
6100 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6101 bombout(("expected RSA public key packet from server"));
6102 crStop(0);
6103 }
6104
6105 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6106 hash_string(ssh->kex->hash, ssh->exhash,
6107 s->hostkeydata, s->hostkeylen);
6108 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6109
6110 {
6111 char *keydata;
6112 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6113 s->rsakeydata = snewn(s->rsakeylen, char);
6114 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6115 }
6116
6117 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6118 if (!s->rsakey) {
6119 sfree(s->rsakeydata);
6120 bombout(("unable to parse RSA public key from server"));
6121 crStop(0);
6122 }
6123
6124 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6125
6126 /*
6127 * Next, set up a shared secret K, of precisely KLEN -
6128 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6129 * RSA key modulus and HLEN is the bit length of the hash
6130 * we're using.
6131 */
6132 {
6133 int klen = ssh_rsakex_klen(s->rsakey);
6134 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6135 int i, byte = 0;
6136 unsigned char *kstr1, *kstr2, *outstr;
6137 int kstr1len, kstr2len, outstrlen;
6138
6139 s->K = bn_power_2(nbits - 1);
6140
6141 for (i = 0; i < nbits; i++) {
6142 if ((i & 7) == 0) {
6143 byte = random_byte();
6144 }
6145 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6146 }
6147
6148 /*
6149 * Encode this as an mpint.
6150 */
6151 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6152 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6153 PUT_32BIT(kstr2, kstr1len);
6154 memcpy(kstr2 + 4, kstr1, kstr1len);
6155
6156 /*
6157 * Encrypt it with the given RSA key.
6158 */
6159 outstrlen = (klen + 7) / 8;
6160 outstr = snewn(outstrlen, unsigned char);
6161 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6162 outstr, outstrlen, s->rsakey);
6163
6164 /*
6165 * And send it off in a return packet.
6166 */
6167 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6168 ssh2_pkt_addstring_start(s->pktout);
7108a872 6169 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
fae1a71b 6170 ssh2_pkt_send_noqueue(ssh, s->pktout);
6171
6172 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6173
6174 sfree(kstr2);
6175 sfree(kstr1);
6176 sfree(outstr);
6177 }
6178
6179 ssh_rsakex_freekey(s->rsakey);
6180
6181 crWaitUntil(pktin);
6182 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6183 sfree(s->rsakeydata);
6184 bombout(("expected signature packet from server"));
6185 crStop(0);
6186 }
6187
6188 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6189
6190 sfree(s->rsakeydata);
6191 }
6192
b672f405 6193 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6194 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6195 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
e5574168 6196
fabd1805 6197 ssh->kex_ctx = NULL;
3709bfe9 6198
7cca0d81 6199#if 0
765c4200 6200 debug(("Exchange hash is:\n"));
b672f405 6201 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7cca0d81 6202#endif
6203
51470298 6204 if (!s->hkey ||
6205 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
b672f405 6206 (char *)s->exchange_hash,
6207 ssh->kex->hash->hlen)) {
6b5cf8b4 6208 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 6209 crStop(0);
8d5de777 6210 }
e5574168 6211
6212 /*
7cca0d81 6213 * Authenticate remote host: verify host key. (We've already
6214 * checked the signature of the exchange hash.)
e5574168 6215 */
51470298 6216 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6217 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 6218 ssh_set_frozen(ssh, 1);
6219 s->dlgret = verify_ssh_host_key(ssh->frontend,
6220 ssh->savedhost, ssh->savedport,
6221 ssh->hostkey->keytype, s->keystr,
6222 s->fingerprint,
6223 ssh_dialog_callback, ssh);
6224 if (s->dlgret < 0) {
6225 do {
6226 crReturn(0);
6227 if (pktin) {
6228 bombout(("Unexpected data from server while waiting"
6229 " for user host key response"));
6230 crStop(0);
6231 }
6232 } while (pktin || inlen > 0);
6233 s->dlgret = ssh->user_response;
6234 }
6235 ssh_set_frozen(ssh, 0);
6236 if (s->dlgret == 0) {
9e296bfa 6237 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6238 0, TRUE);
3d9449a1 6239 crStop(0);
6240 }
e13bba36 6241 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 6242 logevent("Host key fingerprint is:");
51470298 6243 logevent(s->fingerprint);
5e0d7cb8 6244 }
51470298 6245 sfree(s->fingerprint);
6246 sfree(s->keystr);
6247 ssh->hostkey->freekey(s->hkey);
d39f364a 6248
6249 /*
9442dd57 6250 * The exchange hash from the very first key exchange is also
6251 * the session id, used in session key construction and
6252 * authentication.
6253 */
e13bba36 6254 if (!s->got_session_id) {
b672f405 6255 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
9442dd57 6256 memcpy(ssh->v2_session_id, s->exchange_hash,
6257 sizeof(s->exchange_hash));
b672f405 6258 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6052bb76 6259 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
e13bba36 6260 s->got_session_id = TRUE;
6261 }
9442dd57 6262
6263 /*
7cca0d81 6264 * Send SSH2_MSG_NEWKEYS.
d39f364a 6265 */
ff3187f6 6266 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 6267 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 6268 ssh->outgoing_data_size = 0; /* start counting from here */
6269
6270 /*
6271 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 6272 * client-to-server session keys.
9442dd57 6273 */
6274 if (ssh->cs_cipher_ctx)
6275 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6276 ssh->cscipher = s->cscipher_tobe;
6277 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6278
6279 if (ssh->cs_mac_ctx)
6280 ssh->csmac->free_context(ssh->cs_mac_ctx);
6281 ssh->csmac = s->csmac_tobe;
6282 ssh->cs_mac_ctx = ssh->csmac->make_context();
6283
6284 if (ssh->cs_comp_ctx)
6285 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6286 ssh->cscomp = s->cscomp_tobe;
6287 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6288
6289 /*
6290 * Set IVs on client-to-server keys. Here we use the exchange
6291 * hash from the _first_ key exchange.
6292 */
6293 {
754c0df9 6294 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6295 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6296 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
754c0df9 6297 assert((ssh->cscipher->keylen+7) / 8 <=
6298 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6299 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
b672f405 6300 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
754c0df9 6301 assert(ssh->cscipher->blksize <=
6302 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6303 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
b672f405 6304 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
754c0df9 6305 assert(ssh->csmac->len <=
6306 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6307 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
dfb88efd 6308 smemclr(keyspace, sizeof(keyspace));
9442dd57 6309 }
6310
6311 logeventf(ssh, "Initialised %.200s client->server encryption",
6312 ssh->cscipher->text_name);
6313 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6314 ssh->csmac->text_name);
6315 if (ssh->cscomp->text_name)
6316 logeventf(ssh, "Initialised %s compression",
6317 ssh->cscomp->text_name);
590f6a5f 6318
6319 /*
6320 * Now our end of the key exchange is complete, we can send all
6321 * our queued higher-layer packets.
6322 */
6323 ssh->queueing = FALSE;
6324 ssh2_pkt_queuesend(ssh);
d39f364a 6325
6326 /*
8406eaf9 6327 * Expect SSH2_MSG_NEWKEYS from server.
6328 */
ff3187f6 6329 crWaitUntil(pktin);
6330 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 6331 bombout(("expected new-keys packet from server"));
7ffdbc1a 6332 crStop(0);
8406eaf9 6333 }
9442dd57 6334 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 6335
6336 /*
9442dd57 6337 * We've seen server NEWKEYS, so create and initialise
6338 * server-to-client session keys.
d39f364a 6339 */
371e569c 6340 if (ssh->sc_cipher_ctx)
6341 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 6342 ssh->sccipher = s->sccipher_tobe;
371e569c 6343 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 6344
e0e1a00d 6345 if (ssh->sc_mac_ctx)
6346 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 6347 ssh->scmac = s->scmac_tobe;
e0e1a00d 6348 ssh->sc_mac_ctx = ssh->scmac->make_context();
6349
5366aed8 6350 if (ssh->sc_comp_ctx)
6351 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 6352 ssh->sccomp = s->sccomp_tobe;
5366aed8 6353 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6354
d39f364a 6355 /*
9442dd57 6356 * Set IVs on server-to-client keys. Here we use the exchange
6357 * hash from the _first_ key exchange.
d39f364a 6358 */
51470298 6359 {
754c0df9 6360 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6361 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6362 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
754c0df9 6363 assert((ssh->sccipher->keylen+7) / 8 <=
6364 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6365 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
b672f405 6366 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
754c0df9 6367 assert(ssh->sccipher->blksize <=
6368 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6369 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
b672f405 6370 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
754c0df9 6371 assert(ssh->scmac->len <=
6372 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
e0e1a00d 6373 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
dfb88efd 6374 smemclr(keyspace, sizeof(keyspace));
51470298 6375 }
57356d63 6376 logeventf(ssh, "Initialised %.200s server->client encryption",
6377 ssh->sccipher->text_name);
6c135243 6378 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6379 ssh->scmac->text_name);
57356d63 6380 if (ssh->sccomp->text_name)
6381 logeventf(ssh, "Initialised %s decompression",
6382 ssh->sccomp->text_name);
9442dd57 6383
6384 /*
fae1a71b 6385 * Free shared secret.
9442dd57 6386 */
679539d7 6387 freebn(s->K);
d39f364a 6388
033b4cef 6389 /*
e13bba36 6390 * Key exchange is over. Loop straight back round if we have a
6391 * deferred rekey reason.
6392 */
6393 if (ssh->deferred_rekey_reason) {
6394 logevent(ssh->deferred_rekey_reason);
6395 pktin = NULL;
6396 ssh->deferred_rekey_reason = NULL;
6397 goto begin_key_exchange;
6398 }
6399
6400 /*
6401 * Otherwise, schedule a timer for our next rekey.
9442dd57 6402 */
6403 ssh->kex_in_progress = FALSE;
e6c1536e 6404 ssh->last_rekey = GETTICKCOUNT();
4a693cfc 6405 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6406 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
d57f70af 6407 ssh2_timer, ssh);
e13bba36 6408
9442dd57 6409 /*
0db56f73 6410 * If this is the first key exchange phase, we must pass the
6411 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6412 * wants to see it but because it will need time to initialise
6413 * itself before it sees an actual packet. In subsequent key
6414 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6415 * it would only confuse the layer above.
6416 */
e13bba36 6417 if (s->activated_authconn) {
0e3607ed 6418 crReturn(0);
0db56f73 6419 }
e13bba36 6420 s->activated_authconn = TRUE;
0db56f73 6421
6422 /*
7cca0d81 6423 * Now we're encrypting. Begin returning 1 to the protocol main
6424 * function so that other things can run on top of the
6425 * transport. If we ever see a KEXINIT, we must go back to the
6426 * start.
9442dd57 6427 *
6428 * We _also_ go back to the start if we see pktin==NULL and
ab18ccff 6429 * inlen negative, because this is a special signal meaning
9442dd57 6430 * `initiate client-driven rekey', and `in' contains a message
6431 * giving the reason for the rekey.
ab18ccff 6432 *
6433 * inlen==-1 means always initiate a rekey;
6434 * inlen==-2 means that userauth has completed successfully and
6435 * we should consider rekeying (for delayed compression).
033b4cef 6436 */
9442dd57 6437 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
ab18ccff 6438 (!pktin && inlen < 0))) {
f382c87d 6439 wait_for_rekey:
32874aea 6440 crReturn(1);
e96adf72 6441 }
9442dd57 6442 if (pktin) {
6443 logevent("Server initiated key re-exchange");
6444 } else {
ab18ccff 6445 if (inlen == -2) {
6446 /*
6447 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6448 * delayed compression, if it's available.
6449 *
6450 * draft-miller-secsh-compression-delayed-00 says that you
6451 * negotiate delayed compression in the first key exchange, and
6452 * both sides start compressing when the server has sent
6453 * USERAUTH_SUCCESS. This has a race condition -- the server
6454 * can't know when the client has seen it, and thus which incoming
6455 * packets it should treat as compressed.
6456 *
6457 * Instead, we do the initial key exchange without offering the
6458 * delayed methods, but note if the server offers them; when we
6459 * get here, if a delayed method was available that was higher
6460 * on our list than what we got, we initiate a rekey in which we
6461 * _do_ list the delayed methods (and hopefully get it as a
6462 * result). Subsequent rekeys will do the same.
6463 */
6464 assert(!s->userauth_succeeded); /* should only happen once */
6465 s->userauth_succeeded = TRUE;
6466 if (!s->pending_compression)
6467 /* Can't see any point rekeying. */
6468 goto wait_for_rekey; /* this is utterly horrid */
6469 /* else fall through to rekey... */
6470 s->pending_compression = FALSE;
6471 }
f382c87d 6472 /*
ab18ccff 6473 * Now we've decided to rekey.
6474 *
f382c87d 6475 * Special case: if the server bug is set that doesn't
6476 * allow rekeying, we give a different log message and
6477 * continue waiting. (If such a server _initiates_ a rekey,
6478 * we process it anyway!)
6479 */
6480 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6481 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6482 (char *)in);
6483 /* Reset the counters, so that at least this message doesn't
6484 * hit the event log _too_ often. */
6485 ssh->outgoing_data_size = 0;
6486 ssh->incoming_data_size = 0;
4a693cfc 6487 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
f382c87d 6488 ssh->next_rekey =
4a693cfc 6489 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
f382c87d 6490 ssh2_timer, ssh);
6491 }
ab18ccff 6492 goto wait_for_rekey; /* this is still utterly horrid */
f382c87d 6493 } else {
6494 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 6495 }
9442dd57 6496 }
7cca0d81 6497 goto begin_key_exchange;
e5574168 6498
6499 crFinish(1);
6500}
6501
7cca0d81 6502/*
2e85c969 6503 * Add data to an SSH-2 channel output buffer.
783415f8 6504 */
32874aea 6505static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6506 int len)
6507{
5471d09a 6508 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 6509}
6510
6511/*
2e85c969 6512 * Attempt to send data on an SSH-2 channel.
783415f8 6513 */
5471d09a 6514static int ssh2_try_send(struct ssh_channel *c)
32874aea 6515{
51470298 6516 Ssh ssh = c->ssh;
ff3187f6 6517 struct Packet *pktout;
bc06669b 6518 int ret;
51470298 6519
5471d09a 6520 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6521 int len;
6522 void *data;
6523 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6524 if ((unsigned)len > c->v.v2.remwindow)
6525 len = c->v.v2.remwindow;
6526 if ((unsigned)len > c->v.v2.remmaxpkt)
6527 len = c->v.v2.remmaxpkt;
ff3187f6 6528 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6529 ssh2_pkt_adduint32(pktout, c->remoteid);
ff3187f6 6530 ssh2_pkt_addstring_start(pktout);
a2724fba 6531 dont_log_data(ssh, pktout, PKTLOG_OMIT);
ff3187f6 6532 ssh2_pkt_addstring_data(pktout, data, len);
6533 end_log_omission(ssh, pktout);
6534 ssh2_pkt_send(ssh, pktout);
5471d09a 6535 bufchain_consume(&c->v.v2.outbuffer, len);
6536 c->v.v2.remwindow -= len;
6537 }
6538
6539 /*
6540 * After having sent as much data as we can, return the amount
6541 * still buffered.
6542 */
bc06669b 6543 ret = bufchain_size(&c->v.v2.outbuffer);
6544
6545 /*
6546 * And if there's no data pending but we need to send an EOF, send
6547 * it.
6548 */
6549 if (!ret && c->pending_eof)
6550 ssh_channel_try_eof(c);
6551
6552 return ret;
5471d09a 6553}
6554
78280721 6555static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
1bfc7e93 6556{
6557 int bufsize;
bc06669b 6558 if (c->closes & CLOSES_SENT_EOF)
6559 return; /* don't send on channels we've EOFed */
1bfc7e93 6560 bufsize = ssh2_try_send(c);
6561 if (bufsize == 0) {
6562 switch (c->type) {
6563 case CHAN_MAINSESSION:
6564 /* stdin need not receive an unthrottle
6565 * notification since it will be polled */
6566 break;
6567 case CHAN_X11:
6568 x11_unthrottle(c->u.x11.s);
6569 break;
6570 case CHAN_AGENT:
6571 /* agent sockets are request/response and need no
6572 * buffer management */
6573 break;
6574 case CHAN_SOCKDATA:
6575 pfd_unthrottle(c->u.pfd.s);
6576 break;
6577 }
6578 }
6579}
6580
5471d09a 6581/*
94bdfe40 6582 * Set up most of a new ssh_channel for SSH-2.
6583 */
6584static void ssh2_channel_init(struct ssh_channel *c)
6585{
6586 Ssh ssh = c->ssh;
6587 c->localid = alloc_channel_id(ssh);
6588 c->closes = 0;
bc06669b 6589 c->pending_eof = FALSE;
94bdfe40 6590 c->throttling_conn = FALSE;
6591 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
4a693cfc 6592 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
94bdfe40 6593 c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL;
6594 c->v.v2.throttle_state = UNTHROTTLED;
6595 bufchain_init(&c->v.v2.outbuffer);
6596}
6597
6598/*
2e85c969 6599 * Potentially enlarge the window on an SSH-2 channel.
5471d09a 6600 */
9fca3f8c 6601static void ssh2_set_window(struct ssh_channel *c, int newwin)
5471d09a 6602{
51470298 6603 Ssh ssh = c->ssh;
6604
6b69f42e 6605 /*
bc06669b 6606 * Never send WINDOW_ADJUST for a channel that the remote side has
6607 * already sent EOF on; there's no point, since it won't be
beff003a 6608 * sending any more data anyway. Ditto if _we've_ already sent
6609 * CLOSE.
6b69f42e 6610 */
beff003a 6611 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6b69f42e 6612 return;
6613
d252310a 6614 /*
c9739dba 6615 * If the remote end has a habit of ignoring maxpkt, limit the
6616 * window so that it has no choice (assuming it doesn't ignore the
6617 * window as well).
6618 */
6619 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6620 newwin = OUR_V2_MAXPKT;
c9739dba 6621
6622 /*
d252310a 6623 * Only send a WINDOW_ADJUST if there's significantly more window
6624 * available than the other end thinks there is. This saves us
6625 * sending a WINDOW_ADJUST for every character in a shell session.
6626 *
6627 * "Significant" is arbitrarily defined as half the window size.
6628 */
3361b80a 6629 if (newwin / 2 >= c->v.v2.locwindow) {
ff3187f6 6630 struct Packet *pktout;
0e443c99 6631 struct winadj *wa;
ff3187f6 6632
0e443c99 6633 /*
6634 * In order to keep track of how much window the client
6635 * actually has available, we'd like it to acknowledge each
6636 * WINDOW_ADJUST. We can't do that directly, so we accompany
6637 * it with a CHANNEL_REQUEST that has to be acknowledged.
6638 *
6639 * This is only necessary if we're opening the window wide.
6640 * If we're not, then throughput is being constrained by
6641 * something other than the maximum window size anyway.
6642 *
6643 * We also only send this if the main channel has finished its
6644 * initial CHANNEL_REQUESTs and installed the default
6645 * CHANNEL_FAILURE handler, so as not to risk giving it
6646 * unexpected CHANNEL_FAILUREs.
6647 */
6648 if (newwin == c->v.v2.locmaxwin &&
2e0aae4f 6649 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] &&
6650 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
0e443c99 6651 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6652 ssh2_pkt_adduint32(pktout, c->remoteid);
6653 ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");
6654 ssh2_pkt_addbool(pktout, TRUE);
6655 ssh2_pkt_send(ssh, pktout);
6656
6657 /*
6658 * CHANNEL_FAILURE doesn't come with any indication of
6659 * what message caused it, so we have to keep track of the
6660 * outstanding CHANNEL_REQUESTs ourselves.
6661 */
6662 wa = snew(struct winadj);
6663 wa->size = newwin - c->v.v2.locwindow;
6664 wa->next = NULL;
6665 if (!c->v.v2.winadj_head)
6666 c->v.v2.winadj_head = wa;
6667 else
6668 c->v.v2.winadj_tail->next = wa;
6669 c->v.v2.winadj_tail = wa;
6670 if (c->v.v2.throttle_state != UNTHROTTLED)
6671 c->v.v2.throttle_state = UNTHROTTLING;
6672 } else {
6673 /* Pretend the WINDOW_ADJUST was acked immediately. */
6674 c->v.v2.remlocwin = newwin;
6675 c->v.v2.throttle_state = THROTTLED;
6676 }
ff3187f6 6677 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6678 ssh2_pkt_adduint32(pktout, c->remoteid);
6679 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6680 ssh2_pkt_send(ssh, pktout);
5471d09a 6681 c->v.v2.locwindow = newwin;
783415f8 6682 }
6683}
6684
e223b7c7 6685/*
6686 * Find the channel associated with a message. If there's no channel,
6687 * or it's not properly open, make a noise about it and return NULL.
6688 */
6689static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6690{
6691 unsigned localid = ssh_pkt_getuint32(pktin);
6692 struct ssh_channel *c;
6693
6694 c = find234(ssh->channels, &localid, ssh_channelfind);
6695 if (!c ||
6696 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6697 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6698 char *buf = dupprintf("Received %s for %s channel %u",
6699 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6700 pktin->type),
6701 c ? "half-open" : "nonexistent", localid);
6702 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6703 sfree(buf);
6704 return NULL;
6705 }
6706 return c;
6707}
6708
e030765f 6709static int ssh2_handle_winadj_response(struct ssh_channel *c)
6710{
6711 struct winadj *wa = c->v.v2.winadj_head;
6712 if (!wa)
6713 return FALSE;
6714 c->v.v2.winadj_head = wa->next;
6715 c->v.v2.remlocwin += wa->size;
6716 sfree(wa);
6717 /*
6718 * winadj messages are only sent when the window is fully open, so
6719 * if we get an ack of one, we know any pending unthrottle is
6720 * complete.
6721 */
6722 if (c->v.v2.throttle_state == UNTHROTTLING)
6723 c->v.v2.throttle_state = UNTHROTTLED;
997097db 6724 /*
6725 * We may now initiate channel-closing procedures, if that winadj
6726 * was the last thing outstanding before we send CHANNEL_CLOSE.
6727 */
6728 ssh2_channel_check_close(c);
e030765f 6729 return TRUE;
6730}
6731
837d6ba6 6732static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin)
6733{
6734 /*
6735 * This should never get called. All channel requests are either
e030765f 6736 * sent with want_reply false, are sent before this handler gets
6737 * installed, or are "winadj@putty" requests, which servers should
6738 * never respond to with success.
6739 *
6740 * However, at least one server ("boks_sshd") is known to return
6741 * SUCCESS for channel requests it's never heard of, such as
6742 * "winadj@putty". Raised with foxt.com as bug 090916-090424, but
6743 * for the sake of a quiet life, we handle it just the same as the
6744 * expected FAILURE.
837d6ba6 6745 */
6746 struct ssh_channel *c;
837d6ba6 6747
6748 c = ssh2_channel_msg(ssh, pktin);
6749 if (!c)
6750 return;
e030765f 6751 if (!ssh2_handle_winadj_response(c))
837d6ba6 6752 ssh_disconnect(ssh, NULL,
6753 "Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
6754 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6755}
6756
0e443c99 6757static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin)
6758{
6759 /*
6760 * The only time this should get called is for "winadj@putty"
6761 * messages sent above. All other channel requests are either
6762 * sent with want_reply false or are sent before this handler gets
6763 * installed.
6764 */
0e443c99 6765 struct ssh_channel *c;
0e443c99 6766
e223b7c7 6767 c = ssh2_channel_msg(ssh, pktin);
0e443c99 6768 if (!c)
e223b7c7 6769 return;
e030765f 6770 if (!ssh2_handle_winadj_response(c))
837d6ba6 6771 ssh_disconnect(ssh, NULL,
6772 "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
6773 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
0e443c99 6774}
6775
51df0ab5 6776static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 6777{
b09eaa88 6778 struct ssh_channel *c;
e223b7c7 6779 c = ssh2_channel_msg(ssh, pktin);
6780 if (!c)
6781 return;
bc06669b 6782 if (!(c->closes & CLOSES_SENT_EOF)) {
b09eaa88 6783 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
78280721 6784 ssh2_try_send_and_unthrottle(ssh, c);
1bfc7e93 6785 }
b09eaa88 6786}
6787
51df0ab5 6788static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6789{
6790 char *data;
6d44acc9 6791 int length;
51df0ab5 6792 struct ssh_channel *c;
e223b7c7 6793 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 6794 if (!c)
e223b7c7 6795 return;
51df0ab5 6796 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6797 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6798 return; /* extended but not stderr */
6799 ssh_pkt_getstring(pktin, &data, &length);
6800 if (data) {
6801 int bufsize = 0;
6802 c->v.v2.locwindow -= length;
0e443c99 6803 c->v.v2.remlocwin -= length;
51df0ab5 6804 switch (c->type) {
6805 case CHAN_MAINSESSION:
6806 bufsize =
6807 from_backend(ssh->frontend, pktin->type ==
6808 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6809 data, length);
6810 break;
6811 case CHAN_X11:
6812 bufsize = x11_send(c->u.x11.s, data, length);
6813 break;
6814 case CHAN_SOCKDATA:
6815 bufsize = pfd_send(c->u.pfd.s, data, length);
6816 break;
6817 case CHAN_AGENT:
6818 while (length > 0) {
6819 if (c->u.a.lensofar < 4) {
62ddb51e 6820 unsigned int l = min(4 - c->u.a.lensofar,
6821 (unsigned)length);
51df0ab5 6822 memcpy(c->u.a.msglen + c->u.a.lensofar,
6823 data, l);
6824 data += l;
6825 length -= l;
6826 c->u.a.lensofar += l;
6827 }
6828 if (c->u.a.lensofar == 4) {
6829 c->u.a.totallen =
6830 4 + GET_32BIT(c->u.a.msglen);
6831 c->u.a.message = snewn(c->u.a.totallen,
6832 unsigned char);
6833 memcpy(c->u.a.message, c->u.a.msglen, 4);
6834 }
6835 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 6836 unsigned int l =
51df0ab5 6837 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 6838 (unsigned)length);
51df0ab5 6839 memcpy(c->u.a.message + c->u.a.lensofar,
6840 data, l);
6841 data += l;
6842 length -= l;
6843 c->u.a.lensofar += l;
6844 }
6845 if (c->u.a.lensofar == c->u.a.totallen) {
6846 void *reply;
6847 int replylen;
6848 if (agent_query(c->u.a.message,
6849 c->u.a.totallen,
6850 &reply, &replylen,
6851 ssh_agentf_callback, c))
6852 ssh_agentf_callback(c, reply, replylen);
6853 sfree(c->u.a.message);
bc06669b 6854 c->u.a.message = NULL;
51df0ab5 6855 c->u.a.lensofar = 0;
6856 }
6857 }
6858 bufsize = 0;
6859 break;
6860 }
6861 /*
0e443c99 6862 * If it looks like the remote end hit the end of its window,
6863 * and we didn't want it to do that, think about using a
6864 * larger window.
6865 */
6866 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6867 c->v.v2.locmaxwin < 0x40000000)
6868 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6869 /*
51df0ab5 6870 * If we are not buffering too much data,
6871 * enlarge the window again at the remote side.
467e064d 6872 * If we are buffering too much, we may still
6873 * need to adjust the window if the server's
6874 * sent excess data.
51df0ab5 6875 */
9b53e9b8 6876 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6877 c->v.v2.locmaxwin - bufsize : 0);
ff68564b 6878 /*
6879 * If we're either buffering way too much data, or if we're
6880 * buffering anything at all and we're in "simple" mode,
6881 * throttle the whole channel.
6882 */
6883 if ((bufsize > c->v.v2.locmaxwin ||
4a693cfc 6884 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
ff68564b 6885 !c->throttling_conn) {
6886 c->throttling_conn = 1;
6887 ssh_throttle_conn(ssh, +1);
6888 }
51df0ab5 6889 }
6890}
6891
bc06669b 6892static void ssh_channel_destroy(struct ssh_channel *c)
51df0ab5 6893{
bc06669b 6894 Ssh ssh = c->ssh;
51df0ab5 6895
bc06669b 6896 switch (c->type) {
6897 case CHAN_MAINSESSION:
6898 ssh->mainchan = NULL;
6899 update_specials_menu(ssh->frontend);
6900 break;
6901 case CHAN_X11:
6902 if (c->u.x11.s != NULL)
6903 x11_close(c->u.x11.s);
6904 logevent("Forwarded X11 connection terminated");
6905 break;
6906 case CHAN_AGENT:
6907 sfree(c->u.a.message);
6908 break;
6909 case CHAN_SOCKDATA:
6910 if (c->u.pfd.s != NULL)
6911 pfd_close(c->u.pfd.s);
6912 logevent("Forwarded port closed");
6913 break;
6914 }
6915
6916 del234(ssh->channels, c);
6917 if (ssh->version == 2)
6918 bufchain_clear(&c->v.v2.outbuffer);
6919 sfree(c);
6920
6921 /*
6922 * See if that was the last channel left open.
6923 * (This is only our termination condition if we're
6924 * not running in -N mode.)
6925 */
6926 if (ssh->version == 2 &&
6927 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
6928 count234(ssh->channels) == 0) {
6929 /*
6930 * We used to send SSH_MSG_DISCONNECT here,
6931 * because I'd believed that _every_ conforming
6932 * SSH-2 connection had to end with a disconnect
6933 * being sent by at least one side; apparently
6934 * I was wrong and it's perfectly OK to
6935 * unceremoniously slam the connection shut
6936 * when you're done, and indeed OpenSSH feels
6937 * this is more polite than sending a
6938 * DISCONNECT. So now we don't.
6939 */
6940 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6941 }
6942}
6943
6944static void ssh2_channel_check_close(struct ssh_channel *c)
6945{
6946 Ssh ssh = c->ssh;
6947 struct Packet *pktout;
6948
6949 if ((c->closes & (CLOSES_SENT_EOF | CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
997097db 6950 == (CLOSES_SENT_EOF | CLOSES_RCVD_EOF) && !c->v.v2.winadj_head) {
bc06669b 6951 /*
997097db 6952 * We have both sent and received EOF, and we have no
6953 * outstanding winadj channel requests, which means the
6954 * channel is in final wind-up. But we haven't sent CLOSE, so
6955 * let's do so now.
bc06669b 6956 */
6957 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6958 ssh2_pkt_adduint32(pktout, c->remoteid);
6959 ssh2_pkt_send(ssh, pktout);
6960 c->closes |= CLOSES_SENT_CLOSE;
6961 }
6962
6963 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
6964 /*
6965 * We have both sent and received CLOSE, which means we're
6966 * completely done with the channel.
6967 */
6968 ssh_channel_destroy(c);
6969 }
6970}
6971
6972static void ssh2_channel_got_eof(struct ssh_channel *c)
6973{
6974 if (c->closes & CLOSES_RCVD_EOF)
6975 return; /* already seen EOF */
6976 c->closes |= CLOSES_RCVD_EOF;
51df0ab5 6977
6978 if (c->type == CHAN_X11) {
bc06669b 6979 x11_send_eof(c->u.x11.s);
51df0ab5 6980 } else if (c->type == CHAN_AGENT) {
bc06669b 6981 /* Manufacture an outgoing EOF in response to the incoming one. */
6982 sshfwd_write_eof(c);
51df0ab5 6983 } else if (c->type == CHAN_SOCKDATA) {
bc06669b 6984 pfd_send_eof(c->u.pfd.s);
6985 } else if (c->type == CHAN_MAINSESSION) {
6986 Ssh ssh = c->ssh;
6987
4a202fc6 6988 if (!ssh->sent_console_eof &&
6989 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
bc06669b 6990 /*
4a202fc6 6991 * Either from_backend_eof told us that the front end
6992 * wants us to close the outgoing side of the connection
6993 * as soon as we see EOF from the far end, or else we've
6994 * unilaterally decided to do that because we've allocated
6995 * a remote pty and hence EOF isn't a particularly
6996 * meaningful concept.
bc06669b 6997 */
6998 sshfwd_write_eof(c);
6999 }
7000 ssh->sent_console_eof = TRUE;
51df0ab5 7001 }
bc06669b 7002
7003 ssh2_channel_check_close(c);
7004}
7005
7006static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7007{
7008 struct ssh_channel *c;
7009
7010 c = ssh2_channel_msg(ssh, pktin);
7011 if (!c)
7012 return;
7013 ssh2_channel_got_eof(c);
51df0ab5 7014}
7015
7016static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7017{
51df0ab5 7018 struct ssh_channel *c;
51df0ab5 7019
e223b7c7 7020 c = ssh2_channel_msg(ssh, pktin);
7021 if (!c)
51df0ab5 7022 return;
51df0ab5 7023
7024 /*
bc06669b 7025 * When we receive CLOSE on a channel, we assume it comes with an
7026 * implied EOF if we haven't seen EOF yet.
51df0ab5 7027 */
bc06669b 7028 ssh2_channel_got_eof(c);
7029
7030 /*
3effbcf2 7031 * And we also send an outgoing EOF, if we haven't already, on the
7032 * assumption that CLOSE is a pretty forceful announcement that
7033 * the remote side is doing away with the entire channel. (If it
7034 * had wanted to send us EOF and continue receiving data from us,
7035 * it would have just sent CHANNEL_EOF.)
3effbcf2 7036 */
a699eb41 7037 if (!(c->closes & CLOSES_SENT_EOF)) {
7038 /*
7039 * Make sure we don't read any more from whatever our local
7040 * data source is for this channel.
7041 */
7042 switch (c->type) {
7043 case CHAN_MAINSESSION:
7044 ssh->send_ok = 0; /* stop trying to read from stdin */
7045 break;
7046 case CHAN_X11:
7047 x11_override_throttle(c->u.x11.s, 1);
7048 break;
7049 case CHAN_SOCKDATA:
7050 pfd_override_throttle(c->u.pfd.s, 1);
7051 break;
7052 }
7053
7054 /*
7055 * Send outgoing EOF.
7056 */
7539afa2 7057 sshfwd_write_eof(c);
3effbcf2 7058 }
7059
7060 /*
bc06669b 7061 * Now process the actual close.
7062 */
7063 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7064 c->closes |= CLOSES_RCVD_CLOSE;
7065 ssh2_channel_check_close(c);
51df0ab5 7066 }
7067}
7068
7069static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7070{
51df0ab5 7071 struct ssh_channel *c;
51df0ab5 7072
e223b7c7 7073 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7074 if (!c)
e223b7c7 7075 return;
51df0ab5 7076 if (c->type != CHAN_SOCKDATA_DORMANT)
7077 return; /* dunno why they're confirming this */
7078 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 7079 c->halfopen = FALSE;
51df0ab5 7080 c->type = CHAN_SOCKDATA;
7081 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7082 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7083 if (c->u.pfd.s)
7084 pfd_confirm(c->u.pfd.s);
bc06669b 7085 if (c->pending_eof)
7086 ssh_channel_try_eof(c);
51df0ab5 7087}
7088
7089static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7090{
7091 static const char *const reasons[] = {
7092 "<unknown reason code>",
7093 "Administratively prohibited",
7094 "Connect failed",
7095 "Unknown channel type",
7096 "Resource shortage",
7097 };
51df0ab5 7098 unsigned reason_code;
7099 char *reason_string;
7100 int reason_length;
51df0ab5 7101 struct ssh_channel *c;
e223b7c7 7102 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7103 if (!c)
e223b7c7 7104 return;
51df0ab5 7105 if (c->type != CHAN_SOCKDATA_DORMANT)
7106 return; /* dunno why they're failing this */
7107
7108 reason_code = ssh_pkt_getuint32(pktin);
7109 if (reason_code >= lenof(reasons))
7110 reason_code = 0; /* ensure reasons[reason_code] in range */
7111 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 7112 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7113 reasons[reason_code], reason_length, reason_string);
51df0ab5 7114
7115 pfd_close(c->u.pfd.s);
7116
7117 del234(ssh->channels, c);
7118 sfree(c);
7119}
7120
7121static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7122{
51df0ab5 7123 char *type;
7124 int typelen, want_reply;
7125 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7126 struct ssh_channel *c;
7127 struct Packet *pktout;
7128
e223b7c7 7129 c = ssh2_channel_msg(ssh, pktin);
7130 if (!c)
7131 return;
51df0ab5 7132 ssh_pkt_getstring(pktin, &type, &typelen);
7133 want_reply = ssh2_pkt_getbool(pktin);
7134
7135 /*
51df0ab5 7136 * Having got the channel number, we now look at
7137 * the request type string to see if it's something
7138 * we recognise.
7139 */
7140 if (c == ssh->mainchan) {
7141 /*
7142 * We recognise "exit-status" and "exit-signal" on
7143 * the primary channel.
7144 */
7145 if (typelen == 11 &&
7146 !memcmp(type, "exit-status", 11)) {
7147
7148 ssh->exitcode = ssh_pkt_getuint32(pktin);
7149 logeventf(ssh, "Server sent command exit status %d",
7150 ssh->exitcode);
7151 reply = SSH2_MSG_CHANNEL_SUCCESS;
7152
7153 } else if (typelen == 11 &&
7154 !memcmp(type, "exit-signal", 11)) {
7155
7156 int is_plausible = TRUE, is_int = FALSE;
7157 char *fmt_sig = "", *fmt_msg = "";
7158 char *msg;
7159 int msglen = 0, core = FALSE;
7160 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7161 * provide an `int' for the signal, despite its
bccbeb71 7162 * having been a `string' in the drafts of RFC 4254 since at
51df0ab5 7163 * least 2001. (Fixed in session.c 1.147.) Try to
7164 * infer which we can safely parse it as. */
7165 {
7166 unsigned char *p = pktin->body +
7167 pktin->savedpos;
7168 long len = pktin->length - pktin->savedpos;
7169 unsigned long num = GET_32BIT(p); /* what is it? */
7170 /* If it's 0, it hardly matters; assume string */
7171 if (num == 0) {
7172 is_int = FALSE;
7173 } else {
7174 int maybe_int = FALSE, maybe_str = FALSE;
7175#define CHECK_HYPOTHESIS(offset, result) \
7176 do { \
7177 long q = offset; \
7178 if (q >= 0 && q+4 <= len) { \
7179 q = q + 4 + GET_32BIT(p+q); \
7180 if (q >= 0 && q+4 <= len && \
c849ff23 7181 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
51df0ab5 7182 result = TRUE; \
7183 } \
7184 } while(0)
7185 CHECK_HYPOTHESIS(4+1, maybe_int);
7186 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7187#undef CHECK_HYPOTHESIS
7188 if (maybe_int && !maybe_str)
7189 is_int = TRUE;
7190 else if (!maybe_int && maybe_str)
7191 is_int = FALSE;
7192 else
7193 /* Crikey. Either or neither. Panic. */
7194 is_plausible = FALSE;
7195 }
7196 }
d051d1b4 7197 ssh->exitcode = 128; /* means `unknown signal' */
51df0ab5 7198 if (is_plausible) {
7199 if (is_int) {
7200 /* Old non-standard OpenSSH. */
7201 int signum = ssh_pkt_getuint32(pktin);
7202 fmt_sig = dupprintf(" %d", signum);
d051d1b4 7203 ssh->exitcode = 128 + signum;
51df0ab5 7204 } else {
bccbeb71 7205 /* As per RFC 4254. */
51df0ab5 7206 char *sig;
7207 int siglen;
7208 ssh_pkt_getstring(pktin, &sig, &siglen);
7209 /* Signal name isn't supposed to be blank, but
7210 * let's cope gracefully if it is. */
7211 if (siglen) {
7212 fmt_sig = dupprintf(" \"%.*s\"",
7213 siglen, sig);
7214 }
d051d1b4 7215
7216 /*
7217 * Really hideous method of translating the
7218 * signal description back into a locally
7219 * meaningful number.
7220 */
7221
7222 if (0)
7223 ;
b707973a 7224#define TRANSLATE_SIGNAL(s) \
7225 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7226 ssh->exitcode = 128 + SIG ## s
d051d1b4 7227#ifdef SIGABRT
b707973a 7228 TRANSLATE_SIGNAL(ABRT);
d051d1b4 7229#endif
7230#ifdef SIGALRM
b707973a 7231 TRANSLATE_SIGNAL(ALRM);
d051d1b4 7232#endif
7233#ifdef SIGFPE
b707973a 7234 TRANSLATE_SIGNAL(FPE);
d051d1b4 7235#endif
7236#ifdef SIGHUP
b707973a 7237 TRANSLATE_SIGNAL(HUP);
d051d1b4 7238#endif
7239#ifdef SIGILL
b707973a 7240 TRANSLATE_SIGNAL(ILL);
d051d1b4 7241#endif
7242#ifdef SIGINT
b707973a 7243 TRANSLATE_SIGNAL(INT);
d051d1b4 7244#endif
7245#ifdef SIGKILL
b707973a 7246 TRANSLATE_SIGNAL(KILL);
d051d1b4 7247#endif
7248#ifdef SIGPIPE
b707973a 7249 TRANSLATE_SIGNAL(PIPE);
d051d1b4 7250#endif
7251#ifdef SIGQUIT
b707973a 7252 TRANSLATE_SIGNAL(QUIT);
d051d1b4 7253#endif
7254#ifdef SIGSEGV
b707973a 7255 TRANSLATE_SIGNAL(SEGV);
d051d1b4 7256#endif
7257#ifdef SIGTERM
b707973a 7258 TRANSLATE_SIGNAL(TERM);
d051d1b4 7259#endif
7260#ifdef SIGUSR1
b707973a 7261 TRANSLATE_SIGNAL(USR1);
d051d1b4 7262#endif
7263#ifdef SIGUSR2
b707973a 7264 TRANSLATE_SIGNAL(USR2);
d051d1b4 7265#endif
b707973a 7266#undef TRANSLATE_SIGNAL
d051d1b4 7267 else
7268 ssh->exitcode = 128;
51df0ab5 7269 }
7270 core = ssh2_pkt_getbool(pktin);
7271 ssh_pkt_getstring(pktin, &msg, &msglen);
7272 if (msglen) {
7273 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7274 }
7275 /* ignore lang tag */
7276 } /* else don't attempt to parse */
7277 logeventf(ssh, "Server exited on signal%s%s%s",
7278 fmt_sig, core ? " (core dumped)" : "",
7279 fmt_msg);
7280 if (*fmt_sig) sfree(fmt_sig);
7281 if (*fmt_msg) sfree(fmt_msg);
7282 reply = SSH2_MSG_CHANNEL_SUCCESS;
7283
7284 }
7285 } else {
7286 /*
7287 * This is a channel request we don't know
7288 * about, so we now either ignore the request
7289 * or respond with CHANNEL_FAILURE, depending
7290 * on want_reply.
7291 */
7292 reply = SSH2_MSG_CHANNEL_FAILURE;
7293 }
7294 if (want_reply) {
7295 pktout = ssh2_pkt_init(reply);
7296 ssh2_pkt_adduint32(pktout, c->remoteid);
7297 ssh2_pkt_send(ssh, pktout);
7298 }
7299}
7300
7301static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7302{
7303 char *type;
7304 int typelen, want_reply;
7305 struct Packet *pktout;
7306
7307 ssh_pkt_getstring(pktin, &type, &typelen);
7308 want_reply = ssh2_pkt_getbool(pktin);
7309
7310 /*
7311 * We currently don't support any global requests
7312 * at all, so we either ignore the request or
7313 * respond with REQUEST_FAILURE, depending on
7314 * want_reply.
7315 */
7316 if (want_reply) {
7317 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7318 ssh2_pkt_send(ssh, pktout);
7319 }
7320}
7321
7322static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7323{
7324 char *type;
7325 int typelen;
7326 char *peeraddr;
7327 int peeraddrlen;
7328 int peerport;
7329 char *error = NULL;
7330 struct ssh_channel *c;
7331 unsigned remid, winsize, pktsize;
7332 struct Packet *pktout;
7333
7334 ssh_pkt_getstring(pktin, &type, &typelen);
7335 c = snew(struct ssh_channel);
7336 c->ssh = ssh;
7337
7338 remid = ssh_pkt_getuint32(pktin);
7339 winsize = ssh_pkt_getuint32(pktin);
7340 pktsize = ssh_pkt_getuint32(pktin);
7341
7342 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7343 char *addrstr;
5907ebda 7344 const char *x11err;
51df0ab5 7345
7346 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7347 addrstr = snewn(peeraddrlen+1, char);
7348 memcpy(addrstr, peeraddr, peeraddrlen);
7349 addrstr[peeraddrlen] = '\0';
7350 peerport = ssh_pkt_getuint32(pktin);
7351
7352 logeventf(ssh, "Received X11 connect request from %s:%d",
7353 addrstr, peerport);
7354
7355 if (!ssh->X11_fwd_enabled)
7356 error = "X11 forwarding is not enabled";
5907ebda 7357 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
4a693cfc 7358 addrstr, peerport, ssh->conf)) != NULL) {
5907ebda 7359 logeventf(ssh, "Local X11 connection failed: %s", x11err);
51df0ab5 7360 error = "Unable to open an X11 connection";
7361 } else {
7362 logevent("Opening X11 forward connection succeeded");
7363 c->type = CHAN_X11;
7364 }
7365
7366 sfree(addrstr);
7367 } else if (typelen == 15 &&
7368 !memcmp(type, "forwarded-tcpip", 15)) {
7369 struct ssh_rportfwd pf, *realpf;
7370 char *dummy;
7371 int dummylen;
7372 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7373 pf.sport = ssh_pkt_getuint32(pktin);
7374 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7375 peerport = ssh_pkt_getuint32(pktin);
7376 realpf = find234(ssh->rportfwds, &pf, NULL);
7377 logeventf(ssh, "Received remote port %d open request "
7378 "from %s:%d", pf.sport, peeraddr, peerport);
7379 if (realpf == NULL) {
7380 error = "Remote port is not recognised";
7381 } else {
7382 const char *e = pfd_newconnect(&c->u.pfd.s,
7383 realpf->dhost,
7384 realpf->dport, c,
4a693cfc 7385 ssh->conf,
05581745 7386 realpf->pfrec->addressfamily);
51df0ab5 7387 logeventf(ssh, "Attempting to forward remote port to "
7388 "%s:%d", realpf->dhost, realpf->dport);
7389 if (e != NULL) {
7390 logeventf(ssh, "Port open failed: %s", e);
7391 error = "Port open failed";
7392 } else {
7393 logevent("Forwarded port opened successfully");
7394 c->type = CHAN_SOCKDATA;
7395 }
7396 }
7397 } else if (typelen == 22 &&
c49cf994 7398 !memcmp(type, "auth-agent@openssh.com", 22)) {
51df0ab5 7399 if (!ssh->agentfwd_enabled)
7400 error = "Agent forwarding is not enabled";
7401 else {
7402 c->type = CHAN_AGENT; /* identify channel type */
7403 c->u.a.lensofar = 0;
7404 }
7405 } else {
7406 error = "Unsupported channel type requested";
7407 }
7408
7409 c->remoteid = remid;
64d6ff88 7410 c->halfopen = FALSE;
51df0ab5 7411 if (error) {
7412 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7413 ssh2_pkt_adduint32(pktout, c->remoteid);
7414 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7415 ssh2_pkt_addstring(pktout, error);
7416 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7417 ssh2_pkt_send(ssh, pktout);
7418 logeventf(ssh, "Rejected channel open: %s", error);
7419 sfree(c);
7420 } else {
94bdfe40 7421 ssh2_channel_init(c);
51df0ab5 7422 c->v.v2.remwindow = winsize;
7423 c->v.v2.remmaxpkt = pktsize;
51df0ab5 7424 add234(ssh->channels, c);
7425 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7426 ssh2_pkt_adduint32(pktout, c->remoteid);
7427 ssh2_pkt_adduint32(pktout, c->localid);
7428 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 7429 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 7430 ssh2_pkt_send(ssh, pktout);
7431 }
7432}
7433
6bbce591 7434/*
adb6167a 7435 * Buffer banner messages for later display at some convenient point,
7436 * if we're going to display them.
6bbce591 7437 */
7438static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7439{
7440 /* Arbitrary limit to prevent unbounded inflation of buffer */
4a693cfc 7441 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
adb6167a 7442 bufchain_size(&ssh->banner) <= 131072) {
6bbce591 7443 char *banner = NULL;
7444 int size = 0;
7445 ssh_pkt_getstring(pktin, &banner, &size);
7446 if (banner)
7447 bufchain_add(&ssh->banner, banner, size);
7448 }
7449}
7450
c6ccd5c2 7451/* Helper function to deal with sending tty modes for "pty-req" */
7452static void ssh2_send_ttymode(void *data, char *mode, char *val)
7453{
7454 struct Packet *pktout = (struct Packet *)data;
7455 int i = 0;
7456 unsigned int arg = 0;
7457 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7458 if (i == lenof(ssh_ttymodes)) return;
7459 switch (ssh_ttymodes[i].type) {
7460 case TTY_OP_CHAR:
7461 arg = ssh_tty_parse_specchar(val);
7462 break;
7463 case TTY_OP_BOOL:
7464 arg = ssh_tty_parse_boolean(val);
7465 break;
7466 }
7467 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7468 ssh2_pkt_adduint32(pktout, arg);
7469}
7470
783415f8 7471/*
2e85c969 7472 * Handle the SSH-2 userauth and connection layers.
7cca0d81 7473 */
ff3187f6 7474static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7475 struct Packet *pktin)
7cca0d81 7476{
51470298 7477 struct do_ssh2_authconn_state {
30919997 7478 int crLine;
51470298 7479 enum {
51470298 7480 AUTH_TYPE_NONE,
7481 AUTH_TYPE_PUBLICKEY,
7482 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7483 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7484 AUTH_TYPE_PASSWORD,
8221906d 7485 AUTH_TYPE_GSSAPI, /* always QUIET */
51470298 7486 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7487 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7488 } type;
a1a1fae4 7489 int done_service_req;
51470298 7490 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
94cd7c3a 7491 int tried_pubkey_config, done_agent;
bf84a03a 7492#ifndef NO_GSSAPI
42af6a67 7493 int can_gssapi;
7494 int tried_gssapi;
bf84a03a 7495#endif
edd0cb8a 7496 int kbd_inter_refused;
ab18ccff 7497 int we_are_in, userauth_success;
edd0cb8a 7498 prompts_t *cur_prompt;
7499 int num_prompts;
4a693cfc 7500 char *username;
e955d348 7501 char *password;
51470298 7502 int got_username;
51470298 7503 void *publickey_blob;
7504 int publickey_bloblen;
edd0cb8a 7505 int publickey_encrypted;
7506 char *publickey_algorithm;
7507 char *publickey_comment;
94cd7c3a 7508 unsigned char agent_request[5], *agent_response, *agentp;
7509 int agent_responselen;
7510 unsigned char *pkblob_in_agent;
51470298 7511 int keyi, nkeys;
51470298 7512 char *pkblob, *alg, *commentp;
7513 int pklen, alglen, commentlen;
7514 int siglen, retlen, len;
7515 char *q, *agentreq, *ret;
7516 int try_send;
c99deca4 7517 int requested_x11;
7518 int requested_agent;
7519 int requested_tty;
73feed4f 7520 int num_env, env_left, env_ok;
ff3187f6 7521 struct Packet *pktout;
4a693cfc 7522 Filename *keyfile;
bf84a03a 7523#ifndef NO_GSSAPI
b3d375b2 7524 struct ssh_gss_library *gsslib;
42af6a67 7525 Ssh_gss_ctx gss_ctx;
7526 Ssh_gss_buf gss_buf;
7527 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7528 Ssh_gss_name gss_srv_name;
7529 Ssh_gss_stat gss_stat;
bf84a03a 7530#endif
51470298 7531 };
7532 crState(do_ssh2_authconn_state);
7533
30919997 7534 crBeginState;
e5574168 7535
a1a1fae4 7536 s->done_service_req = FALSE;
ab18ccff 7537 s->we_are_in = s->userauth_success = FALSE;
bf84a03a 7538#ifndef NO_GSSAPI
42af6a67 7539 s->tried_gssapi = FALSE;
bf84a03a 7540#endif
42af6a67 7541
4a693cfc 7542 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
a1a1fae4 7543 /*
7544 * Request userauth protocol, and await a response to it.
7545 */
7546 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7547 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7548 ssh2_pkt_send(ssh, s->pktout);
7549 crWaitUntilV(pktin);
7550 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7551 s->done_service_req = TRUE;
7552 }
7553 if (!s->done_service_req) {
7554 /*
7555 * Request connection protocol directly, without authentication.
7556 */
7557 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7558 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7559 ssh2_pkt_send(ssh, s->pktout);
7560 crWaitUntilV(pktin);
7561 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7562 s->we_are_in = TRUE; /* no auth required */
7563 } else {
7564 bombout(("Server refused service request"));
7565 crStopV;
7566 }
8d5de777 7567 }
7cca0d81 7568
94cd7c3a 7569 /* Arrange to be able to deal with any BANNERs that come in.
7570 * (We do this now as packets may come in during the next bit.) */
7571 bufchain_init(&ssh->banner);
7572 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7573 ssh2_msg_userauth_banner;
7574
7cca0d81 7575 /*
edd0cb8a 7576 * Misc one-time setup for authentication.
7577 */
7578 s->publickey_blob = NULL;
7579 if (!s->we_are_in) {
7580
7581 /*
7582 * Load the public half of any configured public key file
7583 * for later use.
7584 */
4a693cfc 7585 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 7586 if (!filename_is_null(s->keyfile)) {
edd0cb8a 7587 int keytype;
7588 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 7589 filename_to_str(s->keyfile));
7590 keytype = key_type(s->keyfile);
edd0cb8a 7591 if (keytype == SSH_KEYTYPE_SSH2) {
7592 const char *error;
7593 s->publickey_blob =
4a693cfc 7594 ssh2_userkey_loadpub(s->keyfile,
edd0cb8a 7595 &s->publickey_algorithm,
7596 &s->publickey_bloblen,
7597 &s->publickey_comment, &error);
7598 if (s->publickey_blob) {
7599 s->publickey_encrypted =
4a693cfc 7600 ssh2_userkey_encrypted(s->keyfile, NULL);
edd0cb8a 7601 } else {
7602 char *msgbuf;
7603 logeventf(ssh, "Unable to load private key (%s)",
7604 error);
7605 msgbuf = dupprintf("Unable to load private key file "
7606 "\"%.150s\" (%s)\r\n",
4a693cfc 7607 filename_to_str(s->keyfile),
edd0cb8a 7608 error);
7609 c_write_str(ssh, msgbuf);
7610 sfree(msgbuf);
7611 }
7612 } else {
7613 char *msgbuf;
7614 logeventf(ssh, "Unable to use this key file (%s)",
7615 key_type_to_str(keytype));
7616 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7617 " (%s)\r\n",
4a693cfc 7618 filename_to_str(s->keyfile),
edd0cb8a 7619 key_type_to_str(keytype));
7620 c_write_str(ssh, msgbuf);
7621 sfree(msgbuf);
7622 s->publickey_blob = NULL;
7623 }
7624 }
7625
94cd7c3a 7626 /*
7627 * Find out about any keys Pageant has (but if there's a
7628 * public key configured, filter out all others).
7629 */
7630 s->nkeys = 0;
7631 s->agent_response = NULL;
7632 s->pkblob_in_agent = NULL;
4a693cfc 7633 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
94cd7c3a 7634
7635 void *r;
7636
7637 logevent("Pageant is running. Requesting keys.");
7638
7639 /* Request the keys held by the agent. */
7640 PUT_32BIT(s->agent_request, 1);
7641 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7642 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7643 ssh_agent_callback, ssh)) {
7644 do {
7645 crReturnV;
7646 if (pktin) {
7647 bombout(("Unexpected data from server while"
7648 " waiting for agent response"));
7649 crStopV;
7650 }
7651 } while (pktin || inlen > 0);
7652 r = ssh->agent_response;
7653 s->agent_responselen = ssh->agent_response_len;
7654 }
7655 s->agent_response = (unsigned char *) r;
7656 if (s->agent_response && s->agent_responselen >= 5 &&
7657 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7658 int keyi;
7659 unsigned char *p;
7660 p = s->agent_response + 5;
7661 s->nkeys = GET_32BIT(p);
7662 p += 4;
7663 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
7664 if (s->publickey_blob) {
7665 /* See if configured key is in agent. */
7666 for (keyi = 0; keyi < s->nkeys; keyi++) {
7667 s->pklen = GET_32BIT(p);
7668 if (s->pklen == s->publickey_bloblen &&
7669 !memcmp(p+4, s->publickey_blob,
7670 s->publickey_bloblen)) {
7671 logeventf(ssh, "Pageant key #%d matches "
7672 "configured key file", keyi);
7673 s->keyi = keyi;
7674 s->pkblob_in_agent = p;
7675 break;
7676 }
7677 p += 4 + s->pklen;
7678 p += GET_32BIT(p) + 4; /* comment */
7679 }
7680 if (!s->pkblob_in_agent) {
7681 logevent("Configured key file not in Pageant");
7682 s->nkeys = 0;
7683 }
7684 }
5ff99b8e 7685 } else {
7686 logevent("Failed to get reply from Pageant");
94cd7c3a 7687 }
7688 }
7689
edd0cb8a 7690 }
7691
7692 /*
1408a877 7693 * We repeat this whole loop, including the username prompt,
7694 * until we manage a successful authentication. If the user
51470298 7695 * types the wrong _password_, they can be sent back to the
7696 * beginning to try another username, if this is configured on.
7697 * (If they specify a username in the config, they are never
7698 * asked, even if they do give a wrong password.)
1408a877 7699 *
7700 * I think this best serves the needs of
7701 *
7702 * - the people who have no configuration, no keys, and just
7703 * want to try repeated (username,password) pairs until they
7704 * type both correctly
7705 *
7706 * - people who have keys and configuration but occasionally
7707 * need to fall back to passwords
7708 *
7709 * - people with a key held in Pageant, who might not have
7710 * logged in to a particular machine before; so they want to
7711 * type a username, and then _either_ their key will be
7712 * accepted, _or_ they will type a password. If they mistype
7713 * the username they will want to be able to get back and
7714 * retype it!
7cca0d81 7715 */
51470298 7716 s->got_username = FALSE;
a1a1fae4 7717 while (!s->we_are_in) {
1408a877 7718 /*
7719 * Get a username.
7720 */
4a693cfc 7721 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
5bb641e1 7722 /*
7723 * We got a username last time round this loop, and
7724 * with change_username turned off we don't try to get
7725 * it again.
7726 */
4a693cfc 7727 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 7728 int ret; /* need not be kept over crReturn */
7729 s->cur_prompt = new_prompts(ssh->frontend);
7730 s->cur_prompt->to_server = TRUE;
7731 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 7732 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 7733 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7734 while (ret < 0) {
51470298 7735 ssh->send_ok = 1;
edd0cb8a 7736 crWaitUntilV(!pktin);
7737 ret = get_userpass_input(s->cur_prompt, in, inlen);
7738 ssh->send_ok = 0;
32874aea 7739 }
edd0cb8a 7740 if (!ret) {
7741 /*
7742 * get_userpass_input() failed to get a username.
7743 * Terminate.
7744 */
7745 free_prompts(s->cur_prompt);
7746 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7747 crStopV;
7748 }
4a693cfc 7749 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 7750 free_prompts(s->cur_prompt);
7cca0d81 7751 } else {
57356d63 7752 char *stuff;
65a22376 7753 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4a693cfc 7754 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
51470298 7755 c_write_str(ssh, stuff);
57356d63 7756 sfree(stuff);
7cca0d81 7757 }
7758 }
51470298 7759 s->got_username = TRUE;
7cca0d81 7760
65a22376 7761 /*
1408a877 7762 * Send an authentication request using method "none": (a)
7763 * just in case it succeeds, and (b) so that we know what
7764 * authentication methods we can usefully try next.
65a22376 7765 */
acab36bc 7766 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
51470298 7767
ff3187f6 7768 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7769 ssh2_pkt_addstring(s->pktout, ssh->username);
ff3187f6 7770 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7771 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7772 ssh2_pkt_send(ssh, s->pktout);
51470298 7773 s->type = AUTH_TYPE_NONE;
7774 s->gotit = FALSE;
7775 s->we_are_in = FALSE;
7776
7777 s->tried_pubkey_config = FALSE;
6ac3a551 7778 s->kbd_inter_refused = FALSE;
65a22376 7779
94cd7c3a 7780 /* Reset agent request state. */
7781 s->done_agent = FALSE;
7782 if (s->agent_response) {
7783 if (s->pkblob_in_agent) {
7784 s->agentp = s->pkblob_in_agent;
7785 } else {
7786 s->agentp = s->agent_response + 5 + 4;
7787 s->keyi = 0;
7788 }
7789 }
7790
1408a877 7791 while (1) {
854caca5 7792 char *methods = NULL;
7793 int methlen = 0;
7794
1408a877 7795 /*
7796 * Wait for the result of the last authentication request.
7797 */
51470298 7798 if (!s->gotit)
ff3187f6 7799 crWaitUntilV(pktin);
6bbce591 7800 /*
7801 * Now is a convenient point to spew any banner material
7802 * that we've accumulated. (This should ensure that when
7803 * we exit the auth loop, we haven't any left to deal
7804 * with.)
7805 */
7806 {
7807 int size = bufchain_size(&ssh->banner);
32874aea 7808 /*
7809 * Don't show the banner if we're operating in
7810 * non-verbose non-interactive mode. (It's probably
7811 * a script, which means nobody will read the
7812 * banner _anyway_, and moreover the printing of
7813 * the banner will screw up processing on the
7814 * output of (say) plink.)
7815 */
6bbce591 7816 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7817 char *banner = snewn(size, char);
7818 bufchain_fetch(&ssh->banner, banner, size);
7819 c_write_untrusted(ssh, banner, size);
7820 sfree(banner);
32874aea 7821 }
6bbce591 7822 bufchain_clear(&ssh->banner);
1408a877 7823 }
ff3187f6 7824 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 7825 logevent("Access granted");
ab18ccff 7826 s->we_are_in = s->userauth_success = TRUE;
1408a877 7827 break;
7828 }
65a22376 7829
42af6a67 7830 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
e955d348 7831 bombout(("Strange packet received during authentication: "
7832 "type %d", pktin->type));
7ffdbc1a 7833 crStopV;
65a22376 7834 }
7835
51470298 7836 s->gotit = FALSE;
65a22376 7837
1408a877 7838 /*
7839 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7840 * we can look at the string in it and know what we can
7841 * helpfully try next.
7842 */
ff3187f6 7843 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
ff3187f6 7844 ssh_pkt_getstring(pktin, &methods, &methlen);
ff3187f6 7845 if (!ssh2_pkt_getbool(pktin)) {
1408a877 7846 /*
7847 * We have received an unequivocal Access
7848 * Denied. This can translate to a variety of
8221906d 7849 * messages, or no message at all.
7850 *
7851 * For forms of authentication which are attempted
7852 * implicitly, by which I mean without printing
7853 * anything in the window indicating that we're
7854 * trying them, we should never print 'Access
7855 * denied'.
7856 *
7857 * If we do print a message saying that we're
7858 * attempting some kind of authentication, it's OK
7859 * to print a followup message saying it failed -
7860 * but the message may sometimes be more specific
7861 * than simply 'Access denied'.
7862 *
1408a877 7863 * Additionally, if we'd just tried password
7864 * authentication, we should break out of this
7865 * whole loop so as to go back to the username
91f57d1f 7866 * prompt (iff we're configured to allow
7867 * username change attempts).
1408a877 7868 */
51470298 7869 if (s->type == AUTH_TYPE_NONE) {
1408a877 7870 /* do nothing */
51470298 7871 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7872 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7873 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7874 c_write_str(ssh, "Server refused our key\r\n");
8221906d 7875 logevent("Server refused our key");
7876 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
7877 /* This _shouldn't_ happen except by a
7878 * protocol bug causing client and server to
7879 * disagree on what is a correct signature. */
7880 c_write_str(ssh, "Server refused public-key signature"
7881 " despite accepting key!\r\n");
7882 logevent("Server refused public-key signature"
7883 " despite accepting key!");
51470298 7884 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8221906d 7885 /* quiet, so no c_write */
7886 logevent("Server refused keyboard-interactive authentication");
7887 } else if (s->type==AUTH_TYPE_GSSAPI) {
7888 /* always quiet, so no c_write */
2af4fe8f 7889 /* also, the code down in the GSSAPI block has
7890 * already logged this in the Event Log */
8221906d 7891 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
7892 logevent("Keyboard-interactive authentication failed");
7893 c_write_str(ssh, "Access denied\r\n");
7894 } else {
7895 assert(s->type == AUTH_TYPE_PASSWORD);
7896 logevent("Password authentication failed");
51470298 7897 c_write_str(ssh, "Access denied\r\n");
8221906d 7898
7899 if (conf_get_int(ssh->conf, CONF_change_username)) {
6c9dce7c 7900 /* XXX perhaps we should allow
7901 * keyboard-interactive to do this too? */
51470298 7902 s->we_are_in = FALSE;
1408a877 7903 break;
7904 }
7905 }
7906 } else {
51470298 7907 c_write_str(ssh, "Further authentication required\r\n");
1408a877 7908 logevent("Further authentication required");
7909 }
65a22376 7910
51470298 7911 s->can_pubkey =
32874aea 7912 in_commasep_string("publickey", methods, methlen);
51470298 7913 s->can_passwd =
32874aea 7914 in_commasep_string("password", methods, methlen);
4a693cfc 7915 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
761187b6 7916 in_commasep_string("keyboard-interactive", methods, methlen);
1e00c92b 7917#ifndef NO_GSSAPI
7918 if (!ssh->gsslibs)
4a693cfc 7919 ssh->gsslibs = ssh_gss_setup(ssh->conf);
7920 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
b3d375b2 7921 in_commasep_string("gssapi-with-mic", methods, methlen) &&
1e00c92b 7922 ssh->gsslibs->nlibraries > 0;
42af6a67 7923#endif
1408a877 7924 }
65a22376 7925
acab36bc 7926 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
65a22376 7927
94cd7c3a 7928 if (s->can_pubkey && !s->done_agent && s->nkeys) {
0405e71f 7929
1983e559 7930 /*
94cd7c3a 7931 * Attempt public-key authentication using a key from Pageant.
1983e559 7932 */
1983e559 7933
acab36bc 7934 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 7935
94cd7c3a 7936 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7937
7938 /* Unpack key from agent response */
7939 s->pklen = GET_32BIT(s->agentp);
7940 s->agentp += 4;
7941 s->pkblob = (char *)s->agentp;
7942 s->agentp += s->pklen;
7943 s->alglen = GET_32BIT(s->pkblob);
7944 s->alg = s->pkblob + 4;
7945 s->commentlen = GET_32BIT(s->agentp);
7946 s->agentp += 4;
7947 s->commentp = (char *)s->agentp;
7948 s->agentp += s->commentlen;
7949 /* s->agentp now points at next key, if any */
7950
7951 /* See if server will accept it */
7952 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7953 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 7954 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7955 /* service requested */
7956 ssh2_pkt_addstring(s->pktout, "publickey");
7957 /* method */
7958 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7959 ssh2_pkt_addstring_start(s->pktout);
7960 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7961 ssh2_pkt_addstring_start(s->pktout);
7962 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7963 ssh2_pkt_send(ssh, s->pktout);
7964 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
1983e559 7965
94cd7c3a 7966 crWaitUntilV(pktin);
7967 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 7968
94cd7c3a 7969 /* Offer of key refused. */
7970 s->gotit = TRUE;
1983e559 7971
94cd7c3a 7972 } else {
7973
7974 void *vret;
1983e559 7975
94cd7c3a 7976 if (flags & FLAG_VERBOSE) {
7977 c_write_str(ssh, "Authenticating with "
7978 "public key \"");
7979 c_write(ssh, s->commentp, s->commentlen);
7980 c_write_str(ssh, "\" from agent\r\n");
7981 }
1983e559 7982
94cd7c3a 7983 /*
7984 * Server is willing to accept the key.
7985 * Construct a SIGN_REQUEST.
7986 */
7987 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7988 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 7989 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7990 /* service requested */
7991 ssh2_pkt_addstring(s->pktout, "publickey");
7992 /* method */
7993 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7994 ssh2_pkt_addstring_start(s->pktout);
7995 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7996 ssh2_pkt_addstring_start(s->pktout);
7997 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7998
7999 /* Ask agent for signature. */
8000 s->siglen = s->pktout->length - 5 + 4 +
8001 ssh->v2_session_id_len;
8002 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8003 s->siglen -= 4;
8004 s->len = 1; /* message type */
8005 s->len += 4 + s->pklen; /* key blob */
8006 s->len += 4 + s->siglen; /* data to sign */
8007 s->len += 4; /* flags */
8008 s->agentreq = snewn(4 + s->len, char);
8009 PUT_32BIT(s->agentreq, s->len);
8010 s->q = s->agentreq + 4;
8011 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8012 PUT_32BIT(s->q, s->pklen);
8013 s->q += 4;
8014 memcpy(s->q, s->pkblob, s->pklen);
8015 s->q += s->pklen;
8016 PUT_32BIT(s->q, s->siglen);
8017 s->q += 4;
8018 /* Now the data to be signed... */
8019 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8020 PUT_32BIT(s->q, ssh->v2_session_id_len);
51470298 8021 s->q += 4;
94cd7c3a 8022 }
8023 memcpy(s->q, ssh->v2_session_id,
8024 ssh->v2_session_id_len);
8025 s->q += ssh->v2_session_id_len;
8026 memcpy(s->q, s->pktout->data + 5,
8027 s->pktout->length - 5);
8028 s->q += s->pktout->length - 5;
8029 /* And finally the (zero) flags word. */
8030 PUT_32BIT(s->q, 0);
8031 if (!agent_query(s->agentreq, s->len + 4,
8032 &vret, &s->retlen,
8033 ssh_agent_callback, ssh)) {
8034 do {
8035 crReturnV;
8036 if (pktin) {
8037 bombout(("Unexpected data from server"
8038 " while waiting for agent"
8039 " response"));
8040 crStopV;
1983e559 8041 }
94cd7c3a 8042 } while (pktin || inlen > 0);
8043 vret = ssh->agent_response;
8044 s->retlen = ssh->agent_response_len;
8045 }
8046 s->ret = vret;
8047 sfree(s->agentreq);
8048 if (s->ret) {
8049 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
8050 logevent("Sending Pageant's response");
8051 ssh2_add_sigblob(ssh, s->pktout,
8052 s->pkblob, s->pklen,
8053 s->ret + 9,
8054 GET_32BIT(s->ret + 5));
8055 ssh2_pkt_send(ssh, s->pktout);
8056 s->type = AUTH_TYPE_PUBLICKEY;
8057 } else {
8058 /* FIXME: less drastic response */
8059 bombout(("Pageant failed to answer challenge"));
8060 crStopV;
1983e559 8061 }
8062 }
1983e559 8063 }
94cd7c3a 8064
8065 /* Do we have any keys left to try? */
8066 if (s->pkblob_in_agent) {
8067 s->done_agent = TRUE;
8068 s->tried_pubkey_config = TRUE;
8069 } else {
8070 s->keyi++;
8071 if (s->keyi >= s->nkeys)
8072 s->done_agent = TRUE;
8073 }
1983e559 8074
edd0cb8a 8075 } else if (s->can_pubkey && s->publickey_blob &&
8076 !s->tried_pubkey_config) {
65a22376 8077
edd0cb8a 8078 struct ssh2_userkey *key; /* not live over crReturn */
8079 char *passphrase; /* not live over crReturn */
65a22376 8080
acab36bc 8081 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 8082
edd0cb8a 8083 s->tried_pubkey_config = TRUE;
8084
65a22376 8085 /*
1408a877 8086 * Try the public key supplied in the configuration.
8087 *
8088 * First, offer the public blob to see if the server is
8089 * willing to accept it.
65a22376 8090 */
ff3187f6 8091 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8092 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8093 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8094 /* service requested */
8095 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8096 ssh2_pkt_addbool(s->pktout, FALSE);
8097 /* no signature included */
8098 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8099 ssh2_pkt_addstring_start(s->pktout);
8100 ssh2_pkt_addstring_data(s->pktout,
8101 (char *)s->publickey_blob,
8102 s->publickey_bloblen);
ff3187f6 8103 ssh2_pkt_send(ssh, s->pktout);
edd0cb8a 8104 logevent("Offered public key");
ff3187f6 8105
8106 crWaitUntilV(pktin);
edd0cb8a 8107 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8108 /* Key refused. Give up. */
8109 s->gotit = TRUE; /* reconsider message next loop */
8110 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8111 continue; /* process this new message */
45068b27 8112 }
edd0cb8a 8113 logevent("Offer of public key accepted");
af659722 8114
45068b27 8115 /*
edd0cb8a 8116 * Actually attempt a serious authentication using
8117 * the key.
45068b27 8118 */
edd0cb8a 8119 if (flags & FLAG_VERBOSE) {
8120 c_write_str(ssh, "Authenticating with public key \"");
8121 c_write_str(ssh, s->publickey_comment);
8122 c_write_str(ssh, "\"\r\n");
8123 }
8124 key = NULL;
8125 while (!key) {
8126 const char *error; /* not live over crReturn */
8127 if (s->publickey_encrypted) {
8128 /*
8129 * Get a passphrase from the user.
8130 */
8131 int ret; /* need not be kept over crReturn */
8132 s->cur_prompt = new_prompts(ssh->frontend);
8133 s->cur_prompt->to_server = FALSE;
8134 s->cur_prompt->name = dupstr("SSH key passphrase");
8135 add_prompt(s->cur_prompt,
8136 dupprintf("Passphrase for key \"%.100s\": ",
8137 s->publickey_comment),
b61f81bc 8138 FALSE);
edd0cb8a 8139 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8140 while (ret < 0) {
8141 ssh->send_ok = 1;
8142 crWaitUntilV(!pktin);
8143 ret = get_userpass_input(s->cur_prompt,
8144 in, inlen);
8145 ssh->send_ok = 0;
8146 }
8147 if (!ret) {
8148 /* Failed to get a passphrase. Terminate. */
8149 free_prompts(s->cur_prompt);
8150 ssh_disconnect(ssh, NULL,
8151 "Unable to authenticate",
8152 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8153 TRUE);
8154 crStopV;
85fdbe25 8155 }
edd0cb8a 8156 passphrase =
8157 dupstr(s->cur_prompt->prompts[0]->result);
8158 free_prompts(s->cur_prompt);
45068b27 8159 } else {
edd0cb8a 8160 passphrase = NULL; /* no passphrase needed */
45068b27 8161 }
1408a877 8162
edd0cb8a 8163 /*
8164 * Try decrypting the key.
8165 */
4a693cfc 8166 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8167 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
edd0cb8a 8168 if (passphrase) {
8169 /* burn the evidence */
dfb88efd 8170 smemclr(passphrase, strlen(passphrase));
edd0cb8a 8171 sfree(passphrase);
8172 }
8173 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8174 if (passphrase &&
8175 (key == SSH2_WRONG_PASSPHRASE)) {
8176 c_write_str(ssh, "Wrong passphrase\r\n");
8177 key = NULL;
8178 /* and loop again */
8179 } else {
8180 c_write_str(ssh, "Unable to load private key (");
8181 c_write_str(ssh, error);
8182 c_write_str(ssh, ")\r\n");
8183 key = NULL;
8184 break; /* try something else */
8185 }
1408a877 8186 }
65a22376 8187 }
65a22376 8188
edd0cb8a 8189 if (key) {
1dd353b5 8190 unsigned char *pkblob, *sigblob, *sigdata;
8191 int pkblob_len, sigblob_len, sigdata_len;
edd0cb8a 8192 int p;
65a22376 8193
1408a877 8194 /*
8195 * We have loaded the private key and the server
8196 * has announced that it's willing to accept it.
8197 * Hallelujah. Generate a signature and send it.
8198 */
ff3187f6 8199 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8200 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8201 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8202 /* service requested */
8203 ssh2_pkt_addstring(s->pktout, "publickey");
8204 /* method */
ff3187f6 8205 ssh2_pkt_addbool(s->pktout, TRUE);
edd0cb8a 8206 /* signature follows */
ff3187f6 8207 ssh2_pkt_addstring(s->pktout, key->alg->name);
edd0cb8a 8208 pkblob = key->alg->public_blob(key->data,
8209 &pkblob_len);
ff3187f6 8210 ssh2_pkt_addstring_start(s->pktout);
edd0cb8a 8211 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8212 pkblob_len);
1408a877 8213
8214 /*
8215 * The data to be signed is:
8216 *
8217 * string session-id
8218 *
8219 * followed by everything so far placed in the
8220 * outgoing packet.
8221 */
b672f405 8222 sigdata_len = s->pktout->length - 5 + 4 +
8223 ssh->v2_session_id_len;
edd0cb8a 8224 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8225 sigdata_len -= 4;
92d60585 8226 sigdata = snewn(sigdata_len, unsigned char);
edd0cb8a 8227 p = 0;
8228 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8229 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8230 p += 4;
8231 }
b672f405 8232 memcpy(sigdata+p, ssh->v2_session_id,
8233 ssh->v2_session_id_len);
8234 p += ssh->v2_session_id_len;
ff3187f6 8235 memcpy(sigdata+p, s->pktout->data + 5,
8236 s->pktout->length - 5);
edd0cb8a 8237 p += s->pktout->length - 5;
8238 assert(p == sigdata_len);
d8baa528 8239 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 8240 sigdata_len, &sigblob_len);
ff3187f6 8241 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 8242 sigblob, sigblob_len);
8243 sfree(pkblob);
8244 sfree(sigblob);
1408a877 8245 sfree(sigdata);
8246
ff3187f6 8247 ssh2_pkt_send(ssh, s->pktout);
8221906d 8248 logevent("Sent public key signature");
51470298 8249 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 8250 key->alg->freekey(key->data);
1408a877 8251 }
edd0cb8a 8252
42af6a67 8253#ifndef NO_GSSAPI
8254 } else if (s->can_gssapi && !s->tried_gssapi) {
8255
8256 /* GSSAPI Authentication */
8257
86557057 8258 int micoffset, len;
8259 char *data;
42af6a67 8260 Ssh_gss_buf mic;
8261 s->type = AUTH_TYPE_GSSAPI;
8262 s->tried_gssapi = TRUE;
8263 s->gotit = TRUE;
8264 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8265
b3d375b2 8266 /*
8267 * Pick the highest GSS library on the preference
8268 * list.
8269 */
8270 {
8271 int i, j;
8272 s->gsslib = NULL;
8273 for (i = 0; i < ngsslibs; i++) {
4a693cfc 8274 int want_id = conf_get_int_int(ssh->conf,
8275 CONF_ssh_gsslist, i);
1e00c92b 8276 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8277 if (ssh->gsslibs->libraries[j].id == want_id) {
8278 s->gsslib = &ssh->gsslibs->libraries[j];
b3d375b2 8279 goto got_gsslib; /* double break */
8280 }
8281 }
8282 got_gsslib:
8283 /*
8284 * We always expect to have found something in
8285 * the above loop: we only came here if there
8286 * was at least one viable GSS library, and the
8287 * preference list should always mention
8288 * everything and only change the order.
8289 */
8290 assert(s->gsslib);
8291 }
8292
8293 if (s->gsslib->gsslogmsg)
8294 logevent(s->gsslib->gsslogmsg);
8295
42af6a67 8296 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8297 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8298 ssh2_pkt_addstring(s->pktout, ssh->username);
42af6a67 8299 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8300 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8221906d 8301 logevent("Attempting GSSAPI authentication");
42af6a67 8302
8303 /* add mechanism info */
b3d375b2 8304 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
42af6a67 8305
8306 /* number of GSSAPI mechanisms */
8307 ssh2_pkt_adduint32(s->pktout,1);
8308
8309 /* length of OID + 2 */
86557057 8310 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
42af6a67 8311 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8312
8313 /* length of OID */
86557057 8314 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
42af6a67 8315
86557057 8316 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8317 s->gss_buf.length);
42af6a67 8318 ssh2_pkt_send(ssh, s->pktout);
8319 crWaitUntilV(pktin);
8320 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8321 logevent("GSSAPI authentication request refused");
8322 continue;
8323 }
8324
8325 /* check returned packet ... */
8326
86557057 8327 ssh_pkt_getstring(pktin, &data, &len);
8328 s->gss_rcvtok.value = data;
8329 s->gss_rcvtok.length = len;
8330 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8331 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8332 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8333 memcmp((char *)s->gss_rcvtok.value + 2,
8334 s->gss_buf.value,s->gss_buf.length) ) {
42af6a67 8335 logevent("GSSAPI authentication - wrong response from server");
8336 continue;
8337 }
8338
8339 /* now start running */
b3d375b2 8340 s->gss_stat = s->gsslib->import_name(s->gsslib,
8341 ssh->fullhostname,
8342 &s->gss_srv_name);
42af6a67 8343 if (s->gss_stat != SSH_GSS_OK) {
8344 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8345 logevent("GSSAPI import name failed - Bad service name");
8346 else
8347 logevent("GSSAPI import name failed");
8348 continue;
8349 }
8350
8351 /* fetch TGT into GSS engine */
b3d375b2 8352 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
42af6a67 8353
8354 if (s->gss_stat != SSH_GSS_OK) {
8355 logevent("GSSAPI authentication failed to get credentials");
b3d375b2 8356 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
42af6a67 8357 continue;
8358 }
8359
8360 /* initial tokens are empty */
86557057 8361 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
99a3b3c9 8362 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
42af6a67 8363
8364 /* now enter the loop */
8365 do {
b3d375b2 8366 s->gss_stat = s->gsslib->init_sec_context
8367 (s->gsslib,
8368 &s->gss_ctx,
8369 s->gss_srv_name,
4a693cfc 8370 conf_get_int(ssh->conf, CONF_gssapifwd),
b3d375b2 8371 &s->gss_rcvtok,
8372 &s->gss_sndtok);
42af6a67 8373
8374 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8375 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8376 logevent("GSSAPI authentication initialisation failed");
8377
b3d375b2 8378 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8379 &s->gss_buf) == SSH_GSS_OK) {
86557057 8380 logevent(s->gss_buf.value);
8381 sfree(s->gss_buf.value);
42af6a67 8382 }
8383
8384 break;
8385 }
8386 logevent("GSSAPI authentication initialised");
8387
8388 /* Client and server now exchange tokens until GSSAPI
8389 * no longer says CONTINUE_NEEDED */
8390
86557057 8391 if (s->gss_sndtok.length != 0) {
42af6a67 8392 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8393 ssh_pkt_addstring_start(s->pktout);
86557057 8394 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
42af6a67 8395 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8396 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
42af6a67 8397 }
8398
8399 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8400 crWaitUntilV(pktin);
8401 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8402 logevent("GSSAPI authentication - bad server response");
8403 s->gss_stat = SSH_GSS_FAILURE;
8404 break;
8405 }
86557057 8406 ssh_pkt_getstring(pktin, &data, &len);
8407 s->gss_rcvtok.value = data;
8408 s->gss_rcvtok.length = len;
42af6a67 8409 }
8410 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8411
8412 if (s->gss_stat != SSH_GSS_OK) {
b3d375b2 8413 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8414 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8415 continue;
8416 }
8417 logevent("GSSAPI authentication loop finished OK");
8418
8419 /* Now send the MIC */
8420
8421 s->pktout = ssh2_pkt_init(0);
8422 micoffset = s->pktout->length;
8423 ssh_pkt_addstring_start(s->pktout);
8424 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8425 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8426 ssh_pkt_addstring(s->pktout, ssh->username);
42af6a67 8427 ssh_pkt_addstring(s->pktout, "ssh-connection");
8428 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8429
86557057 8430 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8431 s->gss_buf.length = s->pktout->length - micoffset;
42af6a67 8432
b3d375b2 8433 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
42af6a67 8434 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8435 ssh_pkt_addstring_start(s->pktout);
86557057 8436 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
42af6a67 8437 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8438 s->gsslib->free_mic(s->gsslib, &mic);
42af6a67 8439
8440 s->gotit = FALSE;
8441
b3d375b2 8442 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8443 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8444 continue;
8445#endif
edd0cb8a 8446 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8447
8448 /*
8449 * Keyboard-interactive authentication.
8450 */
edd0cb8a 8451
edd0cb8a 8452 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8453
acab36bc 8454 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
edd0cb8a 8455
8456 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8457 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8458 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8459 /* service requested */
8460 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8461 /* method */
8462 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8463 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8464 ssh2_pkt_send(ssh, s->pktout);
8221906d 8465
8466 logevent("Attempting keyboard-interactive authentication");
edd0cb8a 8467
8468 crWaitUntilV(pktin);
8469 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8470 /* Server is not willing to do keyboard-interactive
b8e3173d 8471 * at all (or, bizarrely but legally, accepts the
8472 * user without actually issuing any prompts).
8473 * Give up on it entirely. */
edd0cb8a 8474 s->gotit = TRUE;
edd0cb8a 8475 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8476 s->kbd_inter_refused = TRUE; /* don't try it again */
8477 continue;
8478 }
8479
8480 /*
b8e3173d 8481 * Loop while the server continues to send INFO_REQUESTs.
edd0cb8a 8482 */
b8e3173d 8483 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
edd0cb8a 8484
b8e3173d 8485 char *name, *inst, *lang;
8486 int name_len, inst_len, lang_len;
8487 int i;
8488
8489 /*
8490 * We've got a fresh USERAUTH_INFO_REQUEST.
8491 * Get the preamble and start building a prompt.
8492 */
8493 ssh_pkt_getstring(pktin, &name, &name_len);
8494 ssh_pkt_getstring(pktin, &inst, &inst_len);
8495 ssh_pkt_getstring(pktin, &lang, &lang_len);
8496 s->cur_prompt = new_prompts(ssh->frontend);
8497 s->cur_prompt->to_server = TRUE;
edd0cb8a 8498
b8e3173d 8499 /*
9ea10e78 8500 * Get any prompt(s) from the packet.
b8e3173d 8501 */
8502 s->num_prompts = ssh_pkt_getuint32(pktin);
8503 for (i = 0; i < s->num_prompts; i++) {
8504 char *prompt;
8505 int prompt_len;
8506 int echo;
8507 static char noprompt[] =
8508 "<server failed to send prompt>: ";
8509
8510 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8511 echo = ssh2_pkt_getbool(pktin);
8512 if (!prompt_len) {
8513 prompt = noprompt;
8514 prompt_len = lenof(noprompt)-1;
8515 }
8516 add_prompt(s->cur_prompt,
8517 dupprintf("%.*s", prompt_len, prompt),
b61f81bc 8518 echo);
edd0cb8a 8519 }
b8e3173d 8520
9874c9d7 8521 if (name_len) {
8522 /* FIXME: better prefix to distinguish from
8523 * local prompts? */
8524 s->cur_prompt->name =
8525 dupprintf("SSH server: %.*s", name_len, name);
8526 s->cur_prompt->name_reqd = TRUE;
8527 } else {
8528 s->cur_prompt->name =
8529 dupstr("SSH server authentication");
8530 s->cur_prompt->name_reqd = FALSE;
8531 }
8532 /* We add a prefix to try to make it clear that a prompt
8533 * has come from the server.
8534 * FIXME: ugly to print "Using..." in prompt _every_
8535 * time round. Can this be done more subtly? */
8536 /* Special case: for reasons best known to themselves,
8537 * some servers send k-i requests with no prompts and
8538 * nothing to display. Keep quiet in this case. */
8539 if (s->num_prompts || name_len || inst_len) {
8540 s->cur_prompt->instruction =
8541 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8542 inst_len ? "\n" : "", inst_len, inst);
8543 s->cur_prompt->instr_reqd = TRUE;
8544 } else {
8545 s->cur_prompt->instr_reqd = FALSE;
8546 }
8547
b8e3173d 8548 /*
9ea10e78 8549 * Display any instructions, and get the user's
8550 * response(s).
b8e3173d 8551 */
9ea10e78 8552 {
b8e3173d 8553 int ret; /* not live over crReturn */
8554 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8555 while (ret < 0) {
8556 ssh->send_ok = 1;
8557 crWaitUntilV(!pktin);
8558 ret = get_userpass_input(s->cur_prompt, in, inlen);
8559 ssh->send_ok = 0;
8560 }
8561 if (!ret) {
8562 /*
8563 * Failed to get responses. Terminate.
8564 */
8565 free_prompts(s->cur_prompt);
8566 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8567 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8568 TRUE);
8569 crStopV;
8570 }
edd0cb8a 8571 }
b8e3173d 8572
8573 /*
9ea10e78 8574 * Send the response(s) to the server.
b8e3173d 8575 */
8576 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
b8e3173d 8577 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8578 for (i=0; i < s->num_prompts; i++) {
8579 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8580 ssh2_pkt_addstring(s->pktout,
8581 s->cur_prompt->prompts[i]->result);
8582 end_log_omission(ssh, s->pktout);
8583 }
18524056 8584 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
b8e3173d 8585
c69784c0 8586 /*
8587 * Free the prompts structure from this iteration.
8588 * If there's another, a new one will be allocated
8589 * when we return to the top of this while loop.
8590 */
8591 free_prompts(s->cur_prompt);
8592
b8e3173d 8593 /*
8594 * Get the next packet in case it's another
8595 * INFO_REQUEST.
8596 */
8597 crWaitUntilV(pktin);
8598
edd0cb8a 8599 }
8600
8601 /*
b8e3173d 8602 * We should have SUCCESS or FAILURE now.
edd0cb8a 8603 */
b8e3173d 8604 s->gotit = TRUE;
edd0cb8a 8605
8606 } else if (s->can_passwd) {
8607
8608 /*
8609 * Plain old password authentication.
8610 */
8611 int ret; /* not live over crReturn */
e955d348 8612 int changereq_first_time; /* not live over crReturn */
edd0cb8a 8613
acab36bc 8614 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
edd0cb8a 8615
8616 s->cur_prompt = new_prompts(ssh->frontend);
8617 s->cur_prompt->to_server = TRUE;
8618 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 8619 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
8620 ssh->username,
edd0cb8a 8621 ssh->savedhost),
b61f81bc 8622 FALSE);
edd0cb8a 8623
8624 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8625 while (ret < 0) {
8626 ssh->send_ok = 1;
8627 crWaitUntilV(!pktin);
8628 ret = get_userpass_input(s->cur_prompt, in, inlen);
8629 ssh->send_ok = 0;
8630 }
8631 if (!ret) {
8632 /*
8633 * Failed to get responses. Terminate.
8634 */
8635 free_prompts(s->cur_prompt);
8636 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8637 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8638 TRUE);
8639 crStopV;
8640 }
e955d348 8641 /*
8642 * Squirrel away the password. (We may need it later if
8643 * asked to change it.)
8644 */
8645 s->password = dupstr(s->cur_prompt->prompts[0]->result);
8646 free_prompts(s->cur_prompt);
edd0cb8a 8647
8648 /*
8649 * Send the password packet.
8650 *
95d2d262 8651 * We pad out the password packet to 256 bytes to make
8652 * it harder for an attacker to find the length of the
8653 * user's password.
1408a877 8654 *
95d2d262 8655 * Anyone using a password longer than 256 bytes
8656 * probably doesn't have much to worry about from
1408a877 8657 * people who find out how long their password is!
65a22376 8658 */
ff3187f6 8659 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8660 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8661 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8662 /* service requested */
ff3187f6 8663 ssh2_pkt_addstring(s->pktout, "password");
8664 ssh2_pkt_addbool(s->pktout, FALSE);
8665 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
e955d348 8666 ssh2_pkt_addstring(s->pktout, s->password);
ff3187f6 8667 end_log_omission(ssh, s->pktout);
18524056 8668 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
0d43337a 8669 logevent("Sent password");
28f4d4f0 8670 s->type = AUTH_TYPE_PASSWORD;
edd0cb8a 8671
e955d348 8672 /*
8673 * Wait for next packet, in case it's a password change
8674 * request.
8675 */
8676 crWaitUntilV(pktin);
8677 changereq_first_time = TRUE;
8678
8679 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
8680
8681 /*
8682 * We're being asked for a new password
8683 * (perhaps not for the first time).
8684 * Loop until the server accepts it.
8685 */
8686
8687 int got_new = FALSE; /* not live over crReturn */
8688 char *prompt; /* not live over crReturn */
8689 int prompt_len; /* not live over crReturn */
8690
8691 {
8692 char *msg;
8693 if (changereq_first_time)
8694 msg = "Server requested password change";
8695 else
8696 msg = "Server rejected new password";
8697 logevent(msg);
8698 c_write_str(ssh, msg);
8699 c_write_str(ssh, "\r\n");
8700 }
8701
8702 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8703
8704 s->cur_prompt = new_prompts(ssh->frontend);
8705 s->cur_prompt->to_server = TRUE;
8706 s->cur_prompt->name = dupstr("New SSH password");
8707 s->cur_prompt->instruction =
8708 dupprintf("%.*s", prompt_len, prompt);
8709 s->cur_prompt->instr_reqd = TRUE;
d9add7bc 8710 /*
8711 * There's no explicit requirement in the protocol
8712 * for the "old" passwords in the original and
8713 * password-change messages to be the same, and
8714 * apparently some Cisco kit supports password change
8715 * by the user entering a blank password originally
8716 * and the real password subsequently, so,
8717 * reluctantly, we prompt for the old password again.
8718 *
8719 * (On the other hand, some servers don't even bother
8720 * to check this field.)
8721 */
8722 add_prompt(s->cur_prompt,
8723 dupstr("Current password (blank for previously entered password): "),
b61f81bc 8724 FALSE);
e955d348 8725 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
b61f81bc 8726 FALSE);
e955d348 8727 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
b61f81bc 8728 FALSE);
e955d348 8729
8730 /*
8731 * Loop until the user manages to enter the same
8732 * password twice.
8733 */
8734 while (!got_new) {
8735
8736 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8737 while (ret < 0) {
8738 ssh->send_ok = 1;
8739 crWaitUntilV(!pktin);
8740 ret = get_userpass_input(s->cur_prompt, in, inlen);
8741 ssh->send_ok = 0;
8742 }
8743 if (!ret) {
8744 /*
8745 * Failed to get responses. Terminate.
8746 */
8747 /* burn the evidence */
8748 free_prompts(s->cur_prompt);
dfb88efd 8749 smemclr(s->password, strlen(s->password));
e955d348 8750 sfree(s->password);
8751 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8752 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8753 TRUE);
8754 crStopV;
8755 }
8756
8757 /*
d9add7bc 8758 * If the user specified a new original password
8759 * (IYSWIM), overwrite any previously specified
8760 * one.
8761 * (A side effect is that the user doesn't have to
8762 * re-enter it if they louse up the new password.)
8763 */
8764 if (s->cur_prompt->prompts[0]->result[0]) {
dfb88efd 8765 smemclr(s->password, strlen(s->password));
d9add7bc 8766 /* burn the evidence */
8767 sfree(s->password);
8768 s->password =
8769 dupstr(s->cur_prompt->prompts[0]->result);
8770 }
8771
8772 /*
8773 * Check the two new passwords match.
e955d348 8774 */
d9add7bc 8775 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
8776 s->cur_prompt->prompts[2]->result)
e955d348 8777 == 0);
8778 if (!got_new)
8779 /* They don't. Silly user. */
8780 c_write_str(ssh, "Passwords do not match\r\n");
8781
8782 }
8783
8784 /*
8785 * Send the new password (along with the old one).
8786 * (see above for padding rationale)
8787 */
8788 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8789 ssh2_pkt_addstring(s->pktout, ssh->username);
e955d348 8790 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8791 /* service requested */
8792 ssh2_pkt_addstring(s->pktout, "password");
8793 ssh2_pkt_addbool(s->pktout, TRUE);
8794 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8795 ssh2_pkt_addstring(s->pktout, s->password);
8796 ssh2_pkt_addstring(s->pktout,
d9add7bc 8797 s->cur_prompt->prompts[1]->result);
e955d348 8798 free_prompts(s->cur_prompt);
8799 end_log_omission(ssh, s->pktout);
18524056 8800 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
e955d348 8801 logevent("Sent new password");
8802
8803 /*
8804 * Now see what the server has to say about it.
8805 * (If it's CHANGEREQ again, it's not happy with the
8806 * new password.)
8807 */
8808 crWaitUntilV(pktin);
8809 changereq_first_time = FALSE;
8810
8811 }
8812
8813 /*
8814 * We need to reexamine the current pktin at the top
8815 * of the loop. Either:
8816 * - we weren't asked to change password at all, in
8817 * which case it's a SUCCESS or FAILURE with the
8818 * usual meaning
8819 * - we sent a new password, and the server was
8820 * either OK with it (SUCCESS or FAILURE w/partial
8821 * success) or unhappy with the _old_ password
8822 * (FAILURE w/o partial success)
8823 * In any of these cases, we go back to the top of
8824 * the loop and start again.
8825 */
8826 s->gotit = TRUE;
8827
8828 /*
8829 * We don't need the old password any more, in any
8830 * case. Burn the evidence.
8831 */
dfb88efd 8832 smemclr(s->password, strlen(s->password));
e955d348 8833 sfree(s->password);
8834
1408a877 8835 } else {
854caca5 8836 char *str = dupprintf("No supported authentication methods available"
8837 " (server sent: %.*s)",
8838 methlen, methods);
edd0cb8a 8839
854caca5 8840 ssh_disconnect(ssh, str,
9e296bfa 8841 "No supported authentication methods available",
8842 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
8843 FALSE);
854caca5 8844 sfree(str);
8845
7ffdbc1a 8846 crStopV;
edd0cb8a 8847
65a22376 8848 }
edd0cb8a 8849
65a22376 8850 }
a1a1fae4 8851 }
6bbce591 8852 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7cca0d81 8853
edd0cb8a 8854 /* Clear up various bits and pieces from authentication. */
8855 if (s->publickey_blob) {
8856 sfree(s->publickey_blob);
8857 sfree(s->publickey_comment);
8858 }
94cd7c3a 8859 if (s->agent_response)
8860 sfree(s->agent_response);
edd0cb8a 8861
ab18ccff 8862 if (s->userauth_success) {
8863 /*
8864 * We've just received USERAUTH_SUCCESS, and we haven't sent any
8865 * packets since. Signal the transport layer to consider enacting
8866 * delayed compression.
8867 *
8868 * (Relying on we_are_in is not sufficient, as
8869 * draft-miller-secsh-compression-delayed is quite clear that it
8870 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
8871 * become set for other reasons.)
8872 */
8873 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
8874 }
8875
7cca0d81 8876 /*
a1a1fae4 8877 * Now the connection protocol has started, one way or another.
7cca0d81 8878 */
8879
0ed48730 8880 ssh->channels = newtree234(ssh_channelcmp);
8881
7cca0d81 8882 /*
b09eaa88 8883 * Set up handlers for some connection protocol messages, so we
8884 * don't have to handle them repeatedly in this coroutine.
8885 */
8886 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
8887 ssh2_msg_channel_window_adjust;
51df0ab5 8888 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
8889 ssh2_msg_global_request;
b09eaa88 8890
8891 /*
0ed48730 8892 * Create the main session channel.
7cca0d81 8893 */
4a693cfc 8894 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
feb02b4e 8895 ssh->mainchan = NULL;
4a693cfc 8896 } else if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
feb02b4e 8897 /*
8898 * Just start a direct-tcpip channel and use it as the main
8899 * channel.
8900 */
8901 ssh->mainchan = snew(struct ssh_channel);
8902 ssh->mainchan->ssh = ssh;
94bdfe40 8903 ssh2_channel_init(ssh->mainchan);
23828b7e 8904 logeventf(ssh,
8905 "Opening direct-tcpip channel to %s:%d in place of session",
4a693cfc 8906 conf_get_str(ssh->conf, CONF_ssh_nc_host),
8907 conf_get_int(ssh->conf, CONF_ssh_nc_port));
feb02b4e 8908 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8909 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
8910 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
feb02b4e 8911 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8912 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
4a693cfc 8913 ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_ssh_nc_host));
8914 ssh2_pkt_adduint32(s->pktout, conf_get_int(ssh->conf, CONF_ssh_nc_port));
feb02b4e 8915 /*
23828b7e 8916 * There's nothing meaningful to put in the originator
8917 * fields, but some servers insist on syntactically correct
8918 * information.
feb02b4e 8919 */
8920 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
8921 ssh2_pkt_adduint32(s->pktout, 0);
8922 ssh2_pkt_send(ssh, s->pktout);
8923
8924 crWaitUntilV(pktin);
8925 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8926 bombout(("Server refused to open a direct-tcpip channel"));
8927 crStopV;
8928 /* FIXME: error data comes back in FAILURE packet */
8929 }
8930 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8931 bombout(("Server's channel confirmation cited wrong channel"));
8932 crStopV;
8933 }
8934 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8935 ssh->mainchan->halfopen = FALSE;
8936 ssh->mainchan->type = CHAN_MAINSESSION;
feb02b4e 8937 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8938 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
feb02b4e 8939 add234(ssh->channels, ssh->mainchan);
8940 update_specials_menu(ssh->frontend);
23828b7e 8941 logevent("Opened direct-tcpip channel");
feb02b4e 8942 ssh->ncmode = TRUE;
8943 } else {
0ed48730 8944 ssh->mainchan = snew(struct ssh_channel);
8945 ssh->mainchan->ssh = ssh;
94bdfe40 8946 ssh2_channel_init(ssh->mainchan);
ff3187f6 8947 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8948 ssh2_pkt_addstring(s->pktout, "session");
8949 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
ff3187f6 8950 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 8951 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 8952 ssh2_pkt_send(ssh, s->pktout);
8953 crWaitUntilV(pktin);
8954 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 8955 bombout(("Server refused to open a session"));
8956 crStopV;
8957 /* FIXME: error data comes back in FAILURE packet */
8958 }
ff3187f6 8959 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 8960 bombout(("Server's channel confirmation cited wrong channel"));
8961 crStopV;
8962 }
ff3187f6 8963 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 8964 ssh->mainchan->halfopen = FALSE;
0ed48730 8965 ssh->mainchan->type = CHAN_MAINSESSION;
ff3187f6 8966 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8967 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 8968 add234(ssh->channels, ssh->mainchan);
62638676 8969 update_specials_menu(ssh->frontend);
0ed48730 8970 logevent("Opened channel for session");
feb02b4e 8971 ssh->ncmode = FALSE;
8972 }
7cca0d81 8973
8974 /*
51df0ab5 8975 * Now we have a channel, make dispatch table entries for
8976 * general channel-based messages.
8977 */
8978 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8979 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8980 ssh2_msg_channel_data;
8981 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8982 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8983 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8984 ssh2_msg_channel_open_confirmation;
8985 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8986 ssh2_msg_channel_open_failure;
8987 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8988 ssh2_msg_channel_request;
8989 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8990 ssh2_msg_channel_open;
8991
4a693cfc 8992 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
3361b80a 8993 /*
8994 * This message indicates to the server that we promise
8995 * not to try to run any other channel in parallel with
8996 * this one, so it's safe for it to advertise a very large
8997 * window and leave the flow control to TCP.
8998 */
8999 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9000 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
9001 ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
9002 ssh2_pkt_addbool(s->pktout, 0); /* no reply */
9003 ssh2_pkt_send(ssh, s->pktout);
9004 }
9005
51df0ab5 9006 /*
c99deca4 9007 * Enable port forwardings.
9008 */
9009 ssh_setup_portfwd(ssh, ssh->conf);
9010
9011 /*
9012 * Send the CHANNEL_REQUESTS for the main channel. We send them all
9013 * and then start looking for responses, so it's important that the
9014 * sending and receiving code below it is kept in sync.
9015 */
9016
9017 /*
783415f8 9018 * Potentially enable X11 forwarding.
9019 */
4a693cfc 9020 if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_x11_forward) &&
9021 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9022 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
32874aea 9023 logevent("Requesting X11 forwarding");
ff3187f6 9024 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9025 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
9026 ssh2_pkt_addstring(s->pktout, "x11-req");
9027 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9028 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8def70c3 9029 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname);
f68353be 9030 /*
9031 * Note that while we blank the X authentication data here, we don't
9032 * take any special action to blank the start of an X11 channel,
9033 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
9034 * without having session blanking enabled is likely to leak your
9035 * cookie into the log.
9036 */
178c3872 9037 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8def70c3 9038 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring);
178c3872 9039 end_log_omission(ssh, s->pktout);
8def70c3 9040 ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum);
ff3187f6 9041 ssh2_pkt_send(ssh, s->pktout);
c99deca4 9042 s->requested_x11 = TRUE;
9043 } else
9044 s->requested_x11 = FALSE;
bc240b21 9045
9046 /*
36c2a3e9 9047 * Potentially enable agent forwarding.
9048 */
4a693cfc 9049 if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
32874aea 9050 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 9051 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9052 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
9053 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
9054 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9055 ssh2_pkt_send(ssh, s->pktout);
c99deca4 9056 s->requested_agent = TRUE;
9057 } else
9058 s->requested_agent = FALSE;
36c2a3e9 9059
9060 /*
7cca0d81 9061 * Now allocate a pty for the session.
9062 */
4a693cfc 9063 if (ssh->mainchan && !ssh->ncmode && !conf_get_int(ssh->conf, CONF_nopty)) {
a5dd8467 9064 /* Unpick the terminal-speed string. */
9065 /* XXX perhaps we should allow no speeds to be sent. */
db219738 9066 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4a693cfc 9067 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 9068 /* Build the pty request. */
ff3187f6 9069 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9070 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
9071 ssh2_pkt_addstring(s->pktout, "pty-req");
9072 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
4a693cfc 9073 ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_termtype));
ff3187f6 9074 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
9075 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
9076 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
9077 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
9078 ssh2_pkt_addstring_start(s->pktout);
4a693cfc 9079 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)s->pktout);
c6ccd5c2 9080 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
ff3187f6 9081 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
c6ccd5c2 9082 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
ff3187f6 9083 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
9084 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
9085 ssh2_pkt_send(ssh, s->pktout);
51470298 9086 ssh->state = SSH_STATE_INTERMED;
c99deca4 9087 s->requested_tty = TRUE;
9088 } else
9089 s->requested_tty = FALSE;
7cca0d81 9090
9091 /*
73feed4f 9092 * Send environment variables.
9093 *
9094 * Simplest thing here is to send all the requests at once, and
9095 * then wait for a whole bunch of successes or failures.
9096 */
c99deca4 9097 s->num_env = 0;
4a693cfc 9098 if (ssh->mainchan && !ssh->ncmode) {
9099 char *key, *val;
73feed4f 9100
4a693cfc 9101 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9102 val != NULL;
9103 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
ff3187f6 9104 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9105 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
9106 ssh2_pkt_addstring(s->pktout, "env");
9107 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
4a693cfc 9108 ssh2_pkt_addstring(s->pktout, key);
ff3187f6 9109 ssh2_pkt_addstring(s->pktout, val);
9110 ssh2_pkt_send(ssh, s->pktout);
73feed4f 9111
9112 s->num_env++;
9113 }
c99deca4 9114 if (s->num_env)
4a693cfc 9115 logeventf(ssh, "Sent %d environment variables", s->num_env);
c99deca4 9116 }
73feed4f 9117
c99deca4 9118 /*
9119 * All CHANNEL_REQUESTs sent. Now collect up the replies. These
9120 * must be in precisely the same order as the requests.
9121 */
73feed4f 9122
c99deca4 9123 if (s->requested_x11) {
9124 crWaitUntilV(pktin);
73feed4f 9125
c99deca4 9126 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9127 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9128 bombout(("Unexpected response to X11 forwarding request:"
9129 " packet type %d", pktin->type));
9130 crStopV;
9131 }
9132 logevent("X11 forwarding refused");
9133 } else {
9134 logevent("X11 forwarding enabled");
9135 ssh->X11_fwd_enabled = TRUE;
9136 }
9137 }
9138
9139 if (s->requested_agent) {
9140 crWaitUntilV(pktin);
9141
9142 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9143 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9144 bombout(("Unexpected response to agent forwarding request:"
9145 " packet type %d", pktin->type));
9146 crStopV;
9147 }
9148 logevent("Agent forwarding refused");
9149 } else {
9150 logevent("Agent forwarding enabled");
9151 ssh->agentfwd_enabled = TRUE;
9152 }
9153 }
9154
9155 if (s->requested_tty) {
9156 crWaitUntilV(pktin);
73feed4f 9157
c99deca4 9158 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9159 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9160 bombout(("Unexpected response to pty request:"
9161 " packet type %d", pktin->type));
9162 crStopV;
4a693cfc 9163 }
c99deca4 9164 c_write_str(ssh, "Server refused to allocate pty\r\n");
9165 ssh->editing = ssh->echoing = 1;
9166 } else {
9167 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9168 ssh->ospeed, ssh->ispeed);
9169 ssh->got_pty = TRUE;
9170 }
9171 } else {
9172 ssh->editing = ssh->echoing = 1;
9173 }
73feed4f 9174
c99deca4 9175 if (s->num_env) {
9176 s->env_ok = 0;
9177 s->env_left = s->num_env;
9178
9179 while (s->env_left > 0) {
9180 crWaitUntilV(pktin);
9181
9182 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9183 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9184 bombout(("Unexpected response to environment request:"
9185 " packet type %d", pktin->type));
9186 crStopV;
9187 }
4a693cfc 9188 } else {
c99deca4 9189 s->env_ok++;
4a693cfc 9190 }
c99deca4 9191
9192 s->env_left--;
9193 }
9194
9195 if (s->env_ok == s->num_env) {
9196 logevent("All environment variables successfully set");
9197 } else if (s->env_ok == 0) {
9198 logevent("All environment variables refused");
9199 c_write_str(ssh, "Server refused to set environment variables\r\n");
9200 } else {
9201 logeventf(ssh, "%d environment variables refused",
9202 s->num_env - s->env_ok);
9203 c_write_str(ssh, "Server refused to set all environment variables\r\n");
73feed4f 9204 }
9205 }
9206
9207 /*
fd5e5847 9208 * Start a shell or a remote command. We may have to attempt
9209 * this twice if the config data has provided a second choice
9210 * of command.
7cca0d81 9211 */
feb02b4e 9212 if (ssh->mainchan && !ssh->ncmode) while (1) {
fd5e5847 9213 int subsys;
9214 char *cmd;
9215
51470298 9216 if (ssh->fallback_cmd) {
4a693cfc 9217 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9218 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
fd5e5847 9219 } else {
4a693cfc 9220 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9221 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
fd5e5847 9222 }
9223
ff3187f6 9224 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9225 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 9226 if (subsys) {
ff3187f6 9227 ssh2_pkt_addstring(s->pktout, "subsystem");
9228 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9229 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 9230 } else if (*cmd) {
ff3187f6 9231 ssh2_pkt_addstring(s->pktout, "exec");
9232 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9233 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 9234 } else {
ff3187f6 9235 ssh2_pkt_addstring(s->pktout, "shell");
9236 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 9237 }
ff3187f6 9238 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 9239
9240 crWaitUntilV(pktin);
9241
ff3187f6 9242 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9243 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 9244 bombout(("Unexpected response to shell/command request:"
ff3187f6 9245 " packet type %d", pktin->type));
7ffdbc1a 9246 crStopV;
fd5e5847 9247 }
9248 /*
9249 * We failed to start the command. If this is the
9250 * fallback command, we really are finished; if it's
9251 * not, and if the fallback command exists, try falling
9252 * back to it before complaining.
9253 */
4a693cfc 9254 if (!ssh->fallback_cmd &&
9255 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
fd5e5847 9256 logevent("Primary command failed; attempting fallback");
51470298 9257 ssh->fallback_cmd = TRUE;
fd5e5847 9258 continue;
9259 }
6b5cf8b4 9260 bombout(("Server refused to start a shell/command"));
7ffdbc1a 9261 crStopV;
fd5e5847 9262 } else {
9263 logevent("Started a shell/command");
32874aea 9264 }
fd5e5847 9265 break;
7cca0d81 9266 }
9267
51470298 9268 ssh->state = SSH_STATE_SESSION;
9269 if (ssh->size_needed)
9270 ssh_size(ssh, ssh->term_width, ssh->term_height);
9271 if (ssh->eof_needed)
9272 ssh_special(ssh, TS_EOF);
6e48c3fe 9273
7cca0d81 9274 /*
0e443c99 9275 * All the initial channel requests are done, so install the default
9276 * failure handler.
9277 */
837d6ba6 9278 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success;
0e443c99 9279 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure;
9280
9281 /*
7cca0d81 9282 * Transfer data!
9283 */
b9d7bcad 9284 if (ssh->ldisc)
9285 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 9286 if (ssh->mainchan)
9287 ssh->send_ok = 1;
7cca0d81 9288 while (1) {
e5574168 9289 crReturnV;
51470298 9290 s->try_send = FALSE;
ff3187f6 9291 if (pktin) {
2b7540a7 9292
51df0ab5 9293 /*
9294 * _All_ the connection-layer packets we expect to
9295 * receive are now handled by the dispatch table.
9296 * Anything that reaches here must be bogus.
9297 */
32874aea 9298
51df0ab5 9299 bombout(("Strange packet received: type %d", pktin->type));
9300 crStopV;
0ed48730 9301 } else if (ssh->mainchan) {
32874aea 9302 /*
9303 * We have spare data. Add it to the channel buffer.
9304 */
d8baa528 9305 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 9306 s->try_send = TRUE;
32874aea 9307 }
51470298 9308 if (s->try_send) {
32874aea 9309 int i;
9310 struct ssh_channel *c;
9311 /*
9312 * Try to send data on all channels if we can.
9313 */
1bfc7e93 9314 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
78280721 9315 ssh2_try_send_and_unthrottle(ssh, c);
7cca0d81 9316 }
e5574168 9317 }
9318
9319 crFinishV;
9320}
9321
9322/*
2e85c969 9323 * Handlers for SSH-2 messages that might arrive at any moment.
b09eaa88 9324 */
409bfa77 9325static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 9326{
9327 /* log reason code in disconnect message */
9328 char *buf, *msg;
60860bc3 9329 int reason, msglen;
b09eaa88 9330
9331 reason = ssh_pkt_getuint32(pktin);
9332 ssh_pkt_getstring(pktin, &msg, &msglen);
9333
9334 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9335 buf = dupprintf("Received disconnect message (%s)",
9336 ssh2_disconnect_reasons[reason]);
9337 } else {
9338 buf = dupprintf("Received disconnect message (unknown"
9339 " type %d)", reason);
9340 }
9341 logevent(buf);
9342 sfree(buf);
60860bc3 9343 buf = dupprintf("Disconnection message text: %.*s",
9344 msglen, msg);
b09eaa88 9345 logevent(buf);
60860bc3 9346 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
b09eaa88 9347 reason,
9348 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9349 ssh2_disconnect_reasons[reason] : "unknown",
60860bc3 9350 msglen, msg));
b09eaa88 9351 sfree(buf);
9352}
9353
409bfa77 9354static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 9355{
9356 /* log the debug message */
fb983202 9357 char *msg;
b09eaa88 9358 int msglen;
b09eaa88 9359
3ab79841 9360 /* XXX maybe we should actually take notice of the return value */
9361 ssh2_pkt_getbool(pktin);
b09eaa88 9362 ssh_pkt_getstring(pktin, &msg, &msglen);
9363
fb983202 9364 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 9365}
9366
409bfa77 9367static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 9368{
9369 struct Packet *pktout;
9370 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9371 ssh2_pkt_adduint32(pktout, pktin->sequence);
9372 /*
9373 * UNIMPLEMENTED messages MUST appear in the same order as the
9374 * messages they respond to. Hence, never queue them.
9375 */
9376 ssh2_pkt_send_noqueue(ssh, pktout);
9377}
9378
9379/*
2e85c969 9380 * Handle the top-level SSH-2 protocol.
7cca0d81 9381 */
b09eaa88 9382static void ssh2_protocol_setup(Ssh ssh)
9383{
9384 int i;
9385
9386 /*
9387 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9388 */
9389 for (i = 0; i < 256; i++)
9390 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9391
9392 /*
9393 * Any message we actually understand, we set to NULL so that
9394 * the coroutines will get it.
9395 */
9396 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
9397 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
9398 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
9399 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
9400 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
9401 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
9402 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
9403 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
9404 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
9405 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
9406 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
9407 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
9408 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
9409 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
9410 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9411 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
9412 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
9413 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
9414 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
9415 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
9416 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
9417 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
9418 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
9419 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
9420 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
9421 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
9422 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
9423 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
9424 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
9425 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
9426 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
9427 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
9428 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
9429
9430 /*
9431 * These special message types we install handlers for.
9432 */
9433 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
2e85c969 9434 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
b09eaa88 9435 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9436}
9437
9442dd57 9438static void ssh2_timer(void *ctx, long now)
9439{
9440 Ssh ssh = (Ssh)ctx;
9441
ecbb0000 9442 if (ssh->state == SSH_STATE_CLOSED)
9443 return;
9444
4a693cfc 9445 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9442dd57 9446 now - ssh->next_rekey >= 0) {
f382c87d 9447 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 9448 }
9449}
9450
1c1a7262 9451static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 9452 struct Packet *pktin)
7cca0d81 9453{
1c1a7262 9454 unsigned char *in = (unsigned char *)vin;
b09eaa88 9455 if (ssh->state == SSH_STATE_CLOSED)
9456 return;
9457
9442dd57 9458 if (pktin) {
9459 ssh->incoming_data_size += pktin->encrypted_len;
9460 if (!ssh->kex_in_progress &&
d57f70af 9461 ssh->max_data_size != 0 &&
9462 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9463 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 9464 }
9465
b09eaa88 9466 if (pktin && ssh->packet_dispatch[pktin->type]) {
9467 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 9468 return;
b09eaa88 9469 }
9470
9471 if (!ssh->protocol_initial_phase_done ||
9472 (pktin && pktin->type >= 20 && pktin->type < 50)) {
9473 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
9474 !ssh->protocol_initial_phase_done) {
9475 ssh->protocol_initial_phase_done = TRUE;
9476 /*
9477 * Allow authconn to initialise itself.
9478 */
9479 do_ssh2_authconn(ssh, NULL, 0, NULL);
9480 }
9481 } else {
9482 do_ssh2_authconn(ssh, in, inlen, pktin);
9483 }
7cca0d81 9484}
9485
4a693cfc 9486static void ssh_cache_conf_values(Ssh ssh)
9487{
9488 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9489}
9490
7cca0d81 9491/*
8df7a775 9492 * Called to set up the connection.
374330e2 9493 *
9494 * Returns an error message, or NULL on success.
374330e2 9495 */
cbe2d68f 9496static const char *ssh_init(void *frontend_handle, void **backend_handle,
4a693cfc 9497 Conf *conf, char *host, int port, char **realhost,
9498 int nodelay, int keepalive)
32874aea 9499{
cbe2d68f 9500 const char *p;
51470298 9501 Ssh ssh;
9502
3d88e64d 9503 ssh = snew(struct ssh_tag);
4a693cfc 9504 ssh->conf = conf_copy(conf);
9505 ssh_cache_conf_values(ssh);
125105d1 9506 ssh->version = 0; /* when not ready yet */
51470298 9507 ssh->s = NULL;
9508 ssh->cipher = NULL;
371e569c 9509 ssh->v1_cipher_ctx = NULL;
0183b242 9510 ssh->crcda_ctx = NULL;
51470298 9511 ssh->cscipher = NULL;
371e569c 9512 ssh->cs_cipher_ctx = NULL;
51470298 9513 ssh->sccipher = NULL;
371e569c 9514 ssh->sc_cipher_ctx = NULL;
51470298 9515 ssh->csmac = NULL;
a8327734 9516 ssh->cs_mac_ctx = NULL;
51470298 9517 ssh->scmac = NULL;
e0e1a00d 9518 ssh->sc_mac_ctx = NULL;
51470298 9519 ssh->cscomp = NULL;
5366aed8 9520 ssh->cs_comp_ctx = NULL;
51470298 9521 ssh->sccomp = NULL;
5366aed8 9522 ssh->sc_comp_ctx = NULL;
51470298 9523 ssh->kex = NULL;
389aa499 9524 ssh->kex_ctx = NULL;
51470298 9525 ssh->hostkey = NULL;
9526 ssh->exitcode = -1;
ac934965 9527 ssh->close_expected = FALSE;
9e296bfa 9528 ssh->clean_exit = FALSE;
51470298 9529 ssh->state = SSH_STATE_PREPACKET;
9530 ssh->size_needed = FALSE;
9531 ssh->eof_needed = FALSE;
b9d7bcad 9532 ssh->ldisc = NULL;
a8327734 9533 ssh->logctx = NULL;
51470298 9534 ssh->deferred_send_data = NULL;
9535 ssh->deferred_len = 0;
9536 ssh->deferred_size = 0;
9537 ssh->fallback_cmd = 0;
acab36bc 9538 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9539 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8def70c3 9540 ssh->x11disp = NULL;
be738459 9541 ssh->v1_compressing = FALSE;
51470298 9542 ssh->v2_outgoing_sequence = 0;
9543 ssh->ssh1_rdpkt_crstate = 0;
9544 ssh->ssh2_rdpkt_crstate = 0;
51470298 9545 ssh->ssh_gotdata_crstate = 0;
b09eaa88 9546 ssh->do_ssh1_connection_crstate = 0;
51470298 9547 ssh->do_ssh_init_state = NULL;
9548 ssh->do_ssh1_login_state = NULL;
9549 ssh->do_ssh2_transport_state = NULL;
9550 ssh->do_ssh2_authconn_state = NULL;
4320baf7 9551 ssh->v_c = NULL;
9552 ssh->v_s = NULL;
6571dbfd 9553 ssh->mainchan = NULL;
968d2d92 9554 ssh->throttled_all = 0;
9555 ssh->v1_stdout_throttling = 0;
590f6a5f 9556 ssh->queue = NULL;
9557 ssh->queuelen = ssh->queuesize = 0;
9558 ssh->queueing = FALSE;
06fadff5 9559 ssh->qhead = ssh->qtail = NULL;
e13bba36 9560 ssh->deferred_rekey_reason = NULL;
3d9449a1 9561 bufchain_init(&ssh->queued_incoming_data);
9562 ssh->frozen = FALSE;
4a693cfc 9563 ssh->username = NULL;
bc06669b 9564 ssh->sent_console_eof = FALSE;
4a202fc6 9565 ssh->got_pty = FALSE;
51470298 9566
9567 *backend_handle = ssh;
32874aea 9568
8f203108 9569#ifdef MSCRYPTOAPI
32874aea 9570 if (crypto_startup() == 0)
8f203108 9571 return "Microsoft high encryption pack not installed!";
9572#endif
374330e2 9573
51470298 9574 ssh->frontend = frontend_handle;
4a693cfc 9575 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9576 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
887035a5 9577
fabd1805 9578 ssh->channels = NULL;
9579 ssh->rportfwds = NULL;
f47a5ffb 9580 ssh->portfwds = NULL;
fabd1805 9581
51470298 9582 ssh->send_ok = 0;
9583 ssh->editing = 0;
9584 ssh->echoing = 0;
ff68564b 9585 ssh->conn_throttle_count = 0;
51470298 9586 ssh->overall_bufsize = 0;
9587 ssh->fallback_cmd = 0;
8df7a775 9588
3648d4c5 9589 ssh->protocol = NULL;
9590
b09eaa88 9591 ssh->protocol_initial_phase_done = FALSE;
9592
39934deb 9593 ssh->pinger = NULL;
9594
9442dd57 9595 ssh->incoming_data_size = ssh->outgoing_data_size =
9596 ssh->deferred_data_size = 0L;
4a693cfc 9597 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9598 CONF_ssh_rekey_data));
9442dd57 9599 ssh->kex_in_progress = FALSE;
9600
1e00c92b 9601#ifndef NO_GSSAPI
9602 ssh->gsslibs = NULL;
9603#endif
9604
79bf227b 9605 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 9606 if (p != NULL)
9607 return p;
374330e2 9608
5d17ccfc 9609 random_ref();
9610
374330e2 9611 return NULL;
9612}
9613
fabd1805 9614static void ssh_free(void *handle)
9615{
9616 Ssh ssh = (Ssh) handle;
9617 struct ssh_channel *c;
9618 struct ssh_rportfwd *pf;
9619
9620 if (ssh->v1_cipher_ctx)
9621 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9622 if (ssh->cs_cipher_ctx)
9623 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9624 if (ssh->sc_cipher_ctx)
9625 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9626 if (ssh->cs_mac_ctx)
9627 ssh->csmac->free_context(ssh->cs_mac_ctx);
9628 if (ssh->sc_mac_ctx)
9629 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 9630 if (ssh->cs_comp_ctx) {
9631 if (ssh->cscomp)
9632 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9633 else
9634 zlib_compress_cleanup(ssh->cs_comp_ctx);
9635 }
9636 if (ssh->sc_comp_ctx) {
9637 if (ssh->sccomp)
9638 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9639 else
9640 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9641 }
fabd1805 9642 if (ssh->kex_ctx)
9643 dh_cleanup(ssh->kex_ctx);
9644 sfree(ssh->savedhost);
9645
590f6a5f 9646 while (ssh->queuelen-- > 0)
9647 ssh_free_packet(ssh->queue[ssh->queuelen]);
9648 sfree(ssh->queue);
9649
06fadff5 9650 while (ssh->qhead) {
9651 struct queued_handler *qh = ssh->qhead;
9652 ssh->qhead = qh->next;
9653 sfree(ssh->qhead);
9654 }
9655 ssh->qhead = ssh->qtail = NULL;
9656
fabd1805 9657 if (ssh->channels) {
9658 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9659 switch (c->type) {
9660 case CHAN_X11:
9661 if (c->u.x11.s != NULL)
9662 x11_close(c->u.x11.s);
9663 break;
9664 case CHAN_SOCKDATA:
409eca86 9665 case CHAN_SOCKDATA_DORMANT:
fabd1805 9666 if (c->u.pfd.s != NULL)
9667 pfd_close(c->u.pfd.s);
9668 break;
9669 }
9670 sfree(c);
9671 }
9672 freetree234(ssh->channels);
cdb52705 9673 ssh->channels = NULL;
fabd1805 9674 }
9675
9676 if (ssh->rportfwds) {
9677 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8aea57fd 9678 free_rportfwd(pf);
fabd1805 9679 freetree234(ssh->rportfwds);
cdb52705 9680 ssh->rportfwds = NULL;
fabd1805 9681 }
9682 sfree(ssh->deferred_send_data);
8def70c3 9683 if (ssh->x11disp)
9684 x11_free_display(ssh->x11disp);
fabd1805 9685 sfree(ssh->do_ssh_init_state);
9686 sfree(ssh->do_ssh1_login_state);
9687 sfree(ssh->do_ssh2_transport_state);
9688 sfree(ssh->do_ssh2_authconn_state);
4320baf7 9689 sfree(ssh->v_c);
9690 sfree(ssh->v_s);
42af6a67 9691 sfree(ssh->fullhostname);
679539d7 9692 if (ssh->crcda_ctx) {
9693 crcda_free_context(ssh->crcda_ctx);
9694 ssh->crcda_ctx = NULL;
9695 }
fabd1805 9696 if (ssh->s)
ac934965 9697 ssh_do_close(ssh, TRUE);
9442dd57 9698 expire_timer_context(ssh);
39934deb 9699 if (ssh->pinger)
9700 pinger_free(ssh->pinger);
3d9449a1 9701 bufchain_clear(&ssh->queued_incoming_data);
4a693cfc 9702 sfree(ssh->username);
9703 conf_free(ssh->conf);
1e00c92b 9704#ifndef NO_GSSAPI
9705 if (ssh->gsslibs)
9706 ssh_gss_cleanup(ssh->gsslibs);
9707#endif
ee50e8b6 9708 sfree(ssh);
5d17ccfc 9709
9710 random_unref();
fabd1805 9711}
9712
374330e2 9713/*
86916870 9714 * Reconfigure the SSH backend.
86916870 9715 */
4a693cfc 9716static void ssh_reconfig(void *handle, Conf *conf)
86916870 9717{
9718 Ssh ssh = (Ssh) handle;
e13bba36 9719 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 9720 unsigned long old_max_data_size;
4a693cfc 9721 int i, rekey_time;
e6c1536e 9722
4a693cfc 9723 pinger_reconfig(ssh->pinger, ssh->conf, conf);
3b6606c7 9724 if (ssh->portfwds)
4a693cfc 9725 ssh_setup_portfwd(ssh, conf);
e6c1536e 9726
4a693cfc 9727 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
9728 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
9729 rekey_time != 0) {
9730 long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
e6c1536e 9731 long now = GETTICKCOUNT();
9732
9733 if (new_next - now < 0) {
f382c87d 9734 rekeying = "timeout shortened";
e6c1536e 9735 } else {
9736 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9737 }
9738 }
9739
9740 old_max_data_size = ssh->max_data_size;
4a693cfc 9741 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9742 CONF_ssh_rekey_data));
e6c1536e 9743 if (old_max_data_size != ssh->max_data_size &&
9744 ssh->max_data_size != 0) {
9745 if (ssh->outgoing_data_size > ssh->max_data_size ||
9746 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9747 rekeying = "data limit lowered";
e6c1536e 9748 }
9749
4a693cfc 9750 if (conf_get_int(ssh->conf, CONF_compression) !=
9751 conf_get_int(conf, CONF_compression)) {
f382c87d 9752 rekeying = "compression setting changed";
e13bba36 9753 rekey_mandatory = TRUE;
9754 }
9755
4a693cfc 9756 for (i = 0; i < CIPHER_MAX; i++)
9757 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
9758 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
9759 rekeying = "cipher settings changed";
9760 rekey_mandatory = TRUE;
9761 }
9762 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
9763 conf_get_int(conf, CONF_ssh2_des_cbc)) {
f382c87d 9764 rekeying = "cipher settings changed";
e13bba36 9765 rekey_mandatory = TRUE;
e6c1536e 9766 }
9767
4a693cfc 9768 conf_free(ssh->conf);
9769 ssh->conf = conf_copy(conf);
9770 ssh_cache_conf_values(ssh);
e13bba36 9771
9772 if (rekeying) {
9773 if (!ssh->kex_in_progress) {
9774 do_ssh2_transport(ssh, rekeying, -1, NULL);
9775 } else if (rekey_mandatory) {
9776 ssh->deferred_rekey_reason = rekeying;
9777 }
9778 }
86916870 9779}
9780
9781/*
86dc445a 9782 * Called to send data down the SSH connection.
374330e2 9783 */
51470298 9784static int ssh_send(void *handle, char *buf, int len)
32874aea 9785{
51470298 9786 Ssh ssh = (Ssh) handle;
9787
9788 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9789 return 0;
374330e2 9790
d8baa528 9791 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 9792
51470298 9793 return ssh_sendbuffer(ssh);
5471d09a 9794}
9795
9796/*
9797 * Called to query the current amount of buffered stdin data.
9798 */
51470298 9799static int ssh_sendbuffer(void *handle)
5471d09a 9800{
51470298 9801 Ssh ssh = (Ssh) handle;
5471d09a 9802 int override_value;
9803
51470298 9804 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9805 return 0;
9806
9807 /*
9808 * If the SSH socket itself has backed up, add the total backup
9809 * size on that to any individual buffer on the stdin channel.
9810 */
9811 override_value = 0;
51470298 9812 if (ssh->throttled_all)
9813 override_value = ssh->overall_bufsize;
5471d09a 9814
51470298 9815 if (ssh->version == 1) {
5471d09a 9816 return override_value;
51470298 9817 } else if (ssh->version == 2) {
bc06669b 9818 if (!ssh->mainchan)
5471d09a 9819 return override_value;
9820 else
51470298 9821 return (override_value +
9822 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 9823 }
9824
9825 return 0;
374330e2 9826}
9827
9828/*
6e48c3fe 9829 * Called to set the size of the window from SSH's POV.
374330e2 9830 */
51470298 9831static void ssh_size(void *handle, int width, int height)
32874aea 9832{
51470298 9833 Ssh ssh = (Ssh) handle;
ff3187f6 9834 struct Packet *pktout;
51470298 9835
9836 ssh->term_width = width;
9837 ssh->term_height = height;
f278d6f8 9838
51470298 9839 switch (ssh->state) {
374330e2 9840 case SSH_STATE_BEFORE_SIZE:
3687d221 9841 case SSH_STATE_PREPACKET:
21248260 9842 case SSH_STATE_CLOSED:
374330e2 9843 break; /* do nothing */
9844 case SSH_STATE_INTERMED:
51470298 9845 ssh->size_needed = TRUE; /* buffer for later */
374330e2 9846 break;
9847 case SSH_STATE_SESSION:
4a693cfc 9848 if (!conf_get_int(ssh->conf, CONF_nopty)) {
51470298 9849 if (ssh->version == 1) {
9850 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
9851 PKT_INT, ssh->term_height,
9852 PKT_INT, ssh->term_width,
32874aea 9853 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 9854 } else if (ssh->mainchan) {
ff3187f6 9855 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9856 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9857 ssh2_pkt_addstring(pktout, "window-change");
9858 ssh2_pkt_addbool(pktout, 0);
9859 ssh2_pkt_adduint32(pktout, ssh->term_width);
9860 ssh2_pkt_adduint32(pktout, ssh->term_height);
9861 ssh2_pkt_adduint32(pktout, 0);
9862 ssh2_pkt_adduint32(pktout, 0);
9863 ssh2_pkt_send(ssh, pktout);
32874aea 9864 }
9865 }
9866 break;
374330e2 9867 }
9868}
9869
9870/*
125105d1 9871 * Return a list of the special codes that make sense in this
9872 * protocol.
9873 */
9874static const struct telnet_special *ssh_get_specials(void *handle)
9875{
786ba75e 9876 static const struct telnet_special ssh1_ignore_special[] = {
9877 {"IGNORE message", TS_NOP}
9878 };
cf6ddb95 9879 static const struct telnet_special ssh2_ignore_special[] = {
62638676 9880 {"IGNORE message", TS_NOP},
cf6ddb95 9881 };
9882 static const struct telnet_special ssh2_rekey_special[] = {
9442dd57 9883 {"Repeat key exchange", TS_REKEY},
62638676 9884 };
9885 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 9886 {NULL, TS_SEP},
9887 {"Break", TS_BRK},
bccbeb71 9888 /* These are the signal names defined by RFC 4254.
6f2d0cde 9889 * They include all the ISO C signals, but are a subset of the POSIX
9890 * required signals. */
9891 {"SIGINT (Interrupt)", TS_SIGINT},
9892 {"SIGTERM (Terminate)", TS_SIGTERM},
9893 {"SIGKILL (Kill)", TS_SIGKILL},
9894 {"SIGQUIT (Quit)", TS_SIGQUIT},
9895 {"SIGHUP (Hangup)", TS_SIGHUP},
9896 {"More signals", TS_SUBMENU},
9897 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
9898 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
9899 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
9900 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
9901 {NULL, TS_EXITMENU}
62638676 9902 };
9903 static const struct telnet_special specials_end[] = {
6f2d0cde 9904 {NULL, TS_EXITMENU}
62638676 9905 };
786ba75e 9906 /* XXX review this length for any changes: */
cf6ddb95 9907 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
9908 lenof(ssh2_rekey_special) +
62638676 9909 lenof(ssh2_session_specials) +
9910 lenof(specials_end)];
125105d1 9911 Ssh ssh = (Ssh) handle;
62638676 9912 int i = 0;
9913#define ADD_SPECIALS(name) \
9914 do { \
9915 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9916 memcpy(&ssh_specials[i], name, sizeof name); \
9917 i += lenof(name); \
9918 } while(0)
125105d1 9919
9920 if (ssh->version == 1) {
62638676 9921 /* Don't bother offering IGNORE if we've decided the remote
9922 * won't cope with it, since we wouldn't bother sending it if
9923 * asked anyway. */
9924 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 9925 ADD_SPECIALS(ssh1_ignore_special);
125105d1 9926 } else if (ssh->version == 2) {
cf6ddb95 9927 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
9928 ADD_SPECIALS(ssh2_ignore_special);
9929 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
9930 ADD_SPECIALS(ssh2_rekey_special);
62638676 9931 if (ssh->mainchan)
9932 ADD_SPECIALS(ssh2_session_specials);
9933 } /* else we're not ready yet */
9934
9935 if (i) {
9936 ADD_SPECIALS(specials_end);
9937 return ssh_specials;
9938 } else {
125105d1 9939 return NULL;
62638676 9940 }
9941#undef ADD_SPECIALS
125105d1 9942}
9943
9944/*
86dc445a 9945 * Send special codes. TS_EOF is useful for `plink', so you
6abbf9e3 9946 * can send an EOF and collect resulting output (e.g. `plink
9947 * hostname sort').
374330e2 9948 */
51470298 9949static void ssh_special(void *handle, Telnet_Special code)
32874aea 9950{
51470298 9951 Ssh ssh = (Ssh) handle;
ff3187f6 9952 struct Packet *pktout;
51470298 9953
6abbf9e3 9954 if (code == TS_EOF) {
51470298 9955 if (ssh->state != SSH_STATE_SESSION) {
32874aea 9956 /*
9957 * Buffer the EOF in case we are pre-SESSION, so we can
9958 * send it as soon as we reach SESSION.
9959 */
9960 if (code == TS_EOF)
51470298 9961 ssh->eof_needed = TRUE;
32874aea 9962 return;
9963 }
51470298 9964 if (ssh->version == 1) {
9965 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 9966 } else if (ssh->mainchan) {
bc06669b 9967 sshfwd_write_eof(ssh->mainchan);
00a0b113 9968 ssh->send_ok = 0; /* now stop trying to read from stdin */
32874aea 9969 }
9970 logevent("Sent EOF message");
125105d1 9971 } else if (code == TS_PING || code == TS_NOP) {
51470298 9972 if (ssh->state == SSH_STATE_CLOSED
9973 || ssh->state == SSH_STATE_PREPACKET) return;
9974 if (ssh->version == 1) {
9975 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9976 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 9977 } else {
cf6ddb95 9978 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
9979 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
9980 ssh2_pkt_addstring_start(pktout);
9981 ssh2_pkt_send_noqueue(ssh, pktout);
9982 }
32874aea 9983 }
9442dd57 9984 } else if (code == TS_REKEY) {
9985 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 9986 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 9987 }
125105d1 9988 } else if (code == TS_BRK) {
9989 if (ssh->state == SSH_STATE_CLOSED
9990 || ssh->state == SSH_STATE_PREPACKET) return;
9991 if (ssh->version == 1) {
2e85c969 9992 logevent("Unable to send BREAK signal in SSH-1");
0ed48730 9993 } else if (ssh->mainchan) {
ff3187f6 9994 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9995 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9996 ssh2_pkt_addstring(pktout, "break");
9997 ssh2_pkt_addbool(pktout, 0);
9998 ssh2_pkt_adduint32(pktout, 0); /* default break length */
9999 ssh2_pkt_send(ssh, pktout);
125105d1 10000 }
6abbf9e3 10001 } else {
6f2d0cde 10002 /* Is is a POSIX signal? */
10003 char *signame = NULL;
10004 if (code == TS_SIGABRT) signame = "ABRT";
10005 if (code == TS_SIGALRM) signame = "ALRM";
10006 if (code == TS_SIGFPE) signame = "FPE";
10007 if (code == TS_SIGHUP) signame = "HUP";
10008 if (code == TS_SIGILL) signame = "ILL";
10009 if (code == TS_SIGINT) signame = "INT";
10010 if (code == TS_SIGKILL) signame = "KILL";
10011 if (code == TS_SIGPIPE) signame = "PIPE";
10012 if (code == TS_SIGQUIT) signame = "QUIT";
10013 if (code == TS_SIGSEGV) signame = "SEGV";
10014 if (code == TS_SIGTERM) signame = "TERM";
10015 if (code == TS_SIGUSR1) signame = "USR1";
10016 if (code == TS_SIGUSR2) signame = "USR2";
10017 /* The SSH-2 protocol does in principle support arbitrary named
10018 * signals, including signame@domain, but we don't support those. */
10019 if (signame) {
10020 /* It's a signal. */
10021 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 10022 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
10023 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
10024 ssh2_pkt_addstring(pktout, "signal");
10025 ssh2_pkt_addbool(pktout, 0);
10026 ssh2_pkt_addstring(pktout, signame);
10027 ssh2_pkt_send(ssh, pktout);
6f2d0cde 10028 logeventf(ssh, "Sent signal SIG%s", signame);
10029 }
10030 } else {
10031 /* Never heard of it. Do nothing */
10032 }
6abbf9e3 10033 }
374330e2 10034}
10035
51470298 10036void *new_sock_channel(void *handle, Socket s)
d74d141c 10037{
51470298 10038 Ssh ssh = (Ssh) handle;
d74d141c 10039 struct ssh_channel *c;
3d88e64d 10040 c = snew(struct ssh_channel);
d74d141c 10041
70c0cbe1 10042 c->ssh = ssh;
10043 ssh2_channel_init(c);
10044 c->halfopen = TRUE;
10045 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10046 c->u.pfd.s = s;
10047 add234(ssh->channels, c);
d74d141c 10048 return c;
10049}
10050
5471d09a 10051/*
10052 * This is called when stdout/stderr (the entity to which
10053 * from_backend sends data) manages to clear some backlog.
10054 */
ae9ae89f 10055static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 10056{
51470298 10057 Ssh ssh = (Ssh) handle;
ff68564b 10058 int buflimit;
10059
51470298 10060 if (ssh->version == 1) {
10061 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10062 ssh->v1_stdout_throttling = 0;
ff68564b 10063 ssh_throttle_conn(ssh, -1);
5471d09a 10064 }
10065 } else {
ff68564b 10066 if (ssh->mainchan) {
ab87bf1d 10067 ssh2_set_window(ssh->mainchan,
ff68564b 10068 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10069 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
4a693cfc 10070 if (conf_get_int(ssh->conf, CONF_ssh_simple))
ff68564b 10071 buflimit = 0;
10072 else
10073 buflimit = ssh->mainchan->v.v2.locmaxwin;
10074 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10075 ssh->mainchan->throttling_conn = 0;
10076 ssh_throttle_conn(ssh, -1);
10077 }
10078 }
5471d09a 10079 }
78e71de1 10080
10081 /*
10082 * Now process any SSH connection data that was stashed in our
10083 * queue while we were frozen.
10084 */
10085 ssh_process_queued_incoming_data(ssh);
5471d09a 10086}
10087
6b78788a 10088void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 10089{
10090 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 10091 Ssh ssh = c->ssh;
ff3187f6 10092 struct Packet *pktout;
d74d141c 10093
57356d63 10094 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 10095
51470298 10096 if (ssh->version == 1) {
10097 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 10098 PKT_INT, c->localid,
10099 PKT_STR, hostname,
10100 PKT_INT, port,
31fb1866 10101 /* PKT_STR, <org:orgport>, */
bc240b21 10102 PKT_END);
10103 } else {
ff3187f6 10104 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
10105 ssh2_pkt_addstring(pktout, "direct-tcpip");
10106 ssh2_pkt_adduint32(pktout, c->localid);
ff3187f6 10107 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 10108 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 10109 ssh2_pkt_addstring(pktout, hostname);
10110 ssh2_pkt_adduint32(pktout, port);
bc240b21 10111 /*
10112 * We make up values for the originator data; partly it's
10113 * too much hassle to keep track, and partly I'm not
10114 * convinced the server should be told details like that
10115 * about my local network configuration.
1f182589 10116 * The "originator IP address" is syntactically a numeric
10117 * IP address, and some servers (e.g., Tectia) get upset
10118 * if it doesn't match this syntax.
bc240b21 10119 */
1f182589 10120 ssh2_pkt_addstring(pktout, "0.0.0.0");
ff3187f6 10121 ssh2_pkt_adduint32(pktout, 0);
10122 ssh2_pkt_send(ssh, pktout);
bc240b21 10123 }
d74d141c 10124}
10125
6226c939 10126static int ssh_connected(void *handle)
32874aea 10127{
51470298 10128 Ssh ssh = (Ssh) handle;
6226c939 10129 return ssh->s != NULL;
32874aea 10130}
8ccc75b0 10131
51470298 10132static int ssh_sendok(void *handle)
32874aea 10133{
51470298 10134 Ssh ssh = (Ssh) handle;
10135 return ssh->send_ok;
32874aea 10136}
fb09bf1c 10137
51470298 10138static int ssh_ldisc(void *handle, int option)
32874aea 10139{
51470298 10140 Ssh ssh = (Ssh) handle;
32874aea 10141 if (option == LD_ECHO)
51470298 10142 return ssh->echoing;
32874aea 10143 if (option == LD_EDIT)
51470298 10144 return ssh->editing;
0965bee0 10145 return FALSE;
10146}
10147
b9d7bcad 10148static void ssh_provide_ldisc(void *handle, void *ldisc)
10149{
10150 Ssh ssh = (Ssh) handle;
10151 ssh->ldisc = ldisc;
10152}
10153
a8327734 10154static void ssh_provide_logctx(void *handle, void *logctx)
10155{
10156 Ssh ssh = (Ssh) handle;
10157 ssh->logctx = logctx;
10158}
10159
51470298 10160static int ssh_return_exitcode(void *handle)
10161{
10162 Ssh ssh = (Ssh) handle;
3bb2f322 10163 if (ssh->s != NULL)
10164 return -1;
10165 else
3c112d53 10166 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
51470298 10167}
10168
10169/*
f89c3294 10170 * cfg_info for SSH is the currently running version of the
10171 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10172 */
10173static int ssh_cfg_info(void *handle)
10174{
10175 Ssh ssh = (Ssh) handle;
10176 return ssh->version;
10177}
10178
10179/*
51470298 10180 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10181 * that fails. This variable is the means by which scp.c can reach
10182 * into the SSH code and find out which one it got.
10183 */
10184extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 10185{
51470298 10186 Ssh ssh = (Ssh) handle;
10187 return ssh->fallback_cmd;
d8d6c7e5 10188}
10189
374330e2 10190Backend ssh_backend = {
10191 ssh_init,
fabd1805 10192 ssh_free,
86916870 10193 ssh_reconfig,
374330e2 10194 ssh_send,
5471d09a 10195 ssh_sendbuffer,
374330e2 10196 ssh_size,
4017be6d 10197 ssh_special,
125105d1 10198 ssh_get_specials,
6226c939 10199 ssh_connected,
d8d6c7e5 10200 ssh_return_exitcode,
97db3be4 10201 ssh_sendok,
0965bee0 10202 ssh_ldisc,
b9d7bcad 10203 ssh_provide_ldisc,
a8327734 10204 ssh_provide_logctx,
5471d09a 10205 ssh_unthrottle,
f89c3294 10206 ssh_cfg_info,
9e164d82 10207 "ssh",
10208 PROT_SSH,
97db3be4 10209 22
bc240b21 10210};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator