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Patch from Colin Watson to use g_ascii_strcasecmp in place of the
[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
bd358db1 199
c6ccd5c2 200/*
201 * Codes for terminal modes.
202 * Most of these are the same in SSH-1 and SSH-2.
7646c432 203 * This list is derived from RFC 4254 and
c6ccd5c2 204 * SSH-1 RFC-1.2.31.
205 */
206static const struct {
207 const char* const mode;
208 int opcode;
209 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
210} ssh_ttymodes[] = {
211 /* "V" prefix discarded for special characters relative to SSH specs */
212 { "INTR", 1, TTY_OP_CHAR },
213 { "QUIT", 2, TTY_OP_CHAR },
214 { "ERASE", 3, TTY_OP_CHAR },
215 { "KILL", 4, TTY_OP_CHAR },
216 { "EOF", 5, TTY_OP_CHAR },
217 { "EOL", 6, TTY_OP_CHAR },
218 { "EOL2", 7, TTY_OP_CHAR },
219 { "START", 8, TTY_OP_CHAR },
220 { "STOP", 9, TTY_OP_CHAR },
221 { "SUSP", 10, TTY_OP_CHAR },
222 { "DSUSP", 11, TTY_OP_CHAR },
223 { "REPRINT", 12, TTY_OP_CHAR },
224 { "WERASE", 13, TTY_OP_CHAR },
225 { "LNEXT", 14, TTY_OP_CHAR },
226 { "FLUSH", 15, TTY_OP_CHAR },
227 { "SWTCH", 16, TTY_OP_CHAR },
228 { "STATUS", 17, TTY_OP_CHAR },
229 { "DISCARD", 18, TTY_OP_CHAR },
230 { "IGNPAR", 30, TTY_OP_BOOL },
231 { "PARMRK", 31, TTY_OP_BOOL },
232 { "INPCK", 32, TTY_OP_BOOL },
233 { "ISTRIP", 33, TTY_OP_BOOL },
234 { "INLCR", 34, TTY_OP_BOOL },
235 { "IGNCR", 35, TTY_OP_BOOL },
236 { "ICRNL", 36, TTY_OP_BOOL },
237 { "IUCLC", 37, TTY_OP_BOOL },
238 { "IXON", 38, TTY_OP_BOOL },
239 { "IXANY", 39, TTY_OP_BOOL },
240 { "IXOFF", 40, TTY_OP_BOOL },
241 { "IMAXBEL", 41, TTY_OP_BOOL },
242 { "ISIG", 50, TTY_OP_BOOL },
243 { "ICANON", 51, TTY_OP_BOOL },
244 { "XCASE", 52, TTY_OP_BOOL },
245 { "ECHO", 53, TTY_OP_BOOL },
246 { "ECHOE", 54, TTY_OP_BOOL },
247 { "ECHOK", 55, TTY_OP_BOOL },
248 { "ECHONL", 56, TTY_OP_BOOL },
249 { "NOFLSH", 57, TTY_OP_BOOL },
250 { "TOSTOP", 58, TTY_OP_BOOL },
251 { "IEXTEN", 59, TTY_OP_BOOL },
252 { "ECHOCTL", 60, TTY_OP_BOOL },
253 { "ECHOKE", 61, TTY_OP_BOOL },
254 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
255 { "OPOST", 70, TTY_OP_BOOL },
256 { "OLCUC", 71, TTY_OP_BOOL },
257 { "ONLCR", 72, TTY_OP_BOOL },
258 { "OCRNL", 73, TTY_OP_BOOL },
259 { "ONOCR", 74, TTY_OP_BOOL },
260 { "ONLRET", 75, TTY_OP_BOOL },
261 { "CS7", 90, TTY_OP_BOOL },
262 { "CS8", 91, TTY_OP_BOOL },
263 { "PARENB", 92, TTY_OP_BOOL },
264 { "PARODD", 93, TTY_OP_BOOL }
265};
266
267/* Miscellaneous other tty-related constants. */
268#define SSH_TTY_OP_END 0
269/* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
270#define SSH1_TTY_OP_ISPEED 192
271#define SSH1_TTY_OP_OSPEED 193
272#define SSH2_TTY_OP_ISPEED 128
273#define SSH2_TTY_OP_OSPEED 129
274
275/* Helper functions for parsing tty-related config. */
276static unsigned int ssh_tty_parse_specchar(char *s)
277{
278 unsigned int ret;
279 if (*s) {
280 char *next = NULL;
281 ret = ctrlparse(s, &next);
282 if (!next) ret = s[0];
283 } else {
284 ret = 255; /* special value meaning "don't set" */
285 }
286 return ret;
287}
288static unsigned int ssh_tty_parse_boolean(char *s)
289{
290 if (stricmp(s, "yes") == 0 ||
291 stricmp(s, "on") == 0 ||
292 stricmp(s, "true") == 0 ||
293 stricmp(s, "+") == 0)
294 return 1; /* true */
295 else if (stricmp(s, "no") == 0 ||
296 stricmp(s, "off") == 0 ||
297 stricmp(s, "false") == 0 ||
298 stricmp(s, "-") == 0)
299 return 0; /* false */
300 else
301 return (atoi(s) != 0);
302}
303
00db133f 304#define translate(x) if (type == x) return #x
acab36bc 305#define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
306#define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
ae9ae89f 307static char *ssh1_pkt_type(int type)
00db133f 308{
309 translate(SSH1_MSG_DISCONNECT);
310 translate(SSH1_SMSG_PUBLIC_KEY);
311 translate(SSH1_CMSG_SESSION_KEY);
312 translate(SSH1_CMSG_USER);
313 translate(SSH1_CMSG_AUTH_RSA);
314 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
315 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
316 translate(SSH1_CMSG_AUTH_PASSWORD);
317 translate(SSH1_CMSG_REQUEST_PTY);
318 translate(SSH1_CMSG_WINDOW_SIZE);
319 translate(SSH1_CMSG_EXEC_SHELL);
320 translate(SSH1_CMSG_EXEC_CMD);
321 translate(SSH1_SMSG_SUCCESS);
322 translate(SSH1_SMSG_FAILURE);
323 translate(SSH1_CMSG_STDIN_DATA);
324 translate(SSH1_SMSG_STDOUT_DATA);
325 translate(SSH1_SMSG_STDERR_DATA);
326 translate(SSH1_CMSG_EOF);
327 translate(SSH1_SMSG_EXIT_STATUS);
328 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
329 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
330 translate(SSH1_MSG_CHANNEL_DATA);
331 translate(SSH1_MSG_CHANNEL_CLOSE);
332 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
333 translate(SSH1_SMSG_X11_OPEN);
334 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
335 translate(SSH1_MSG_PORT_OPEN);
336 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
337 translate(SSH1_SMSG_AGENT_OPEN);
338 translate(SSH1_MSG_IGNORE);
339 translate(SSH1_CMSG_EXIT_CONFIRMATION);
340 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
341 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
342 translate(SSH1_MSG_DEBUG);
343 translate(SSH1_CMSG_REQUEST_COMPRESSION);
344 translate(SSH1_CMSG_AUTH_TIS);
345 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
346 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
347 translate(SSH1_CMSG_AUTH_CCARD);
348 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
349 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
350 return "unknown";
351}
acab36bc 352static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
00db133f 353{
42af6a67 354 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
355 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
356 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
357 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
358 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
359 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
00db133f 360 translate(SSH2_MSG_DISCONNECT);
361 translate(SSH2_MSG_IGNORE);
362 translate(SSH2_MSG_UNIMPLEMENTED);
363 translate(SSH2_MSG_DEBUG);
364 translate(SSH2_MSG_SERVICE_REQUEST);
365 translate(SSH2_MSG_SERVICE_ACCEPT);
366 translate(SSH2_MSG_KEXINIT);
367 translate(SSH2_MSG_NEWKEYS);
acab36bc 368 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
369 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
370 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
371 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
372 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
373 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
374 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
375 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
376 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
00db133f 377 translate(SSH2_MSG_USERAUTH_REQUEST);
378 translate(SSH2_MSG_USERAUTH_FAILURE);
379 translate(SSH2_MSG_USERAUTH_SUCCESS);
380 translate(SSH2_MSG_USERAUTH_BANNER);
acab36bc 381 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
382 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
383 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
384 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
00db133f 385 translate(SSH2_MSG_GLOBAL_REQUEST);
386 translate(SSH2_MSG_REQUEST_SUCCESS);
387 translate(SSH2_MSG_REQUEST_FAILURE);
388 translate(SSH2_MSG_CHANNEL_OPEN);
389 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
390 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
391 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
392 translate(SSH2_MSG_CHANNEL_DATA);
393 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
394 translate(SSH2_MSG_CHANNEL_EOF);
395 translate(SSH2_MSG_CHANNEL_CLOSE);
396 translate(SSH2_MSG_CHANNEL_REQUEST);
397 translate(SSH2_MSG_CHANNEL_SUCCESS);
398 translate(SSH2_MSG_CHANNEL_FAILURE);
399 return "unknown";
400}
401#undef translate
402#undef translatec
7d503c31 403
9a10ecf4 404/* Enumeration values for fields in SSH-1 packets */
405enum {
406 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
407 /* These values are for communicating relevant semantics of
408 * fields to the packet logging code. */
409 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
410};
972a41c8 411
acddebd9 412/*
413 * Coroutine mechanics for the sillier bits of the code. If these
414 * macros look impenetrable to you, you might find it helpful to
415 * read
416 *
417 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
418 *
419 * which explains the theory behind these macros.
b624d1e6 420 *
421 * In particular, if you are getting `case expression not constant'
422 * errors when building with MS Visual Studio, this is because MS's
423 * Edit and Continue debugging feature causes their compiler to
424 * violate ANSI C. To disable Edit and Continue debugging:
425 *
426 * - right-click ssh.c in the FileView
427 * - click Settings
428 * - select the C/C++ tab and the General category
429 * - under `Debug info:', select anything _other_ than `Program
430 * Database for Edit and Continue'.
acddebd9 431 */
51470298 432#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
433#define crState(t) \
434 struct t *s; \
3d88e64d 435 if (!ssh->t) ssh->t = snew(struct t); \
51470298 436 s = ssh->t;
437#define crFinish(z) } *crLine = 0; return (z); }
438#define crFinishV } *crLine = 0; return; }
374330e2 439#define crReturn(z) \
440 do {\
51470298 441 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 442 } while (0)
443#define crReturnV \
444 do {\
51470298 445 *crLine=__LINE__; return; case __LINE__:;\
374330e2 446 } while (0)
51470298 447#define crStop(z) do{ *crLine = 0; return (z); }while(0)
448#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 449#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 450#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 451
51470298 452typedef struct ssh_tag *Ssh;
ff3187f6 453struct Packet;
454
dacd8872 455static struct Packet *ssh1_pkt_init(int pkt_type);
ff3187f6 456static struct Packet *ssh2_pkt_init(int pkt_type);
dacd8872 457static void ssh_pkt_ensure(struct Packet *, int length);
458static void ssh_pkt_adddata(struct Packet *, void *data, int len);
459static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
ff3187f6 460static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
dacd8872 461static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
462static void ssh_pkt_addstring_start(struct Packet *);
463static void ssh_pkt_addstring_str(struct Packet *, char *data);
464static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
465static void ssh_pkt_addstring(struct Packet *, char *data);
d8baa528 466static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
dacd8872 467static void ssh1_pkt_addmp(struct Packet *, Bignum b);
ff3187f6 468static void ssh2_pkt_addmp(struct Packet *, Bignum b);
469static int ssh2_pkt_construct(Ssh, struct Packet *);
470static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 471static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 472static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
473 struct Packet *pktin);
474static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
475 struct Packet *pktin);
997097db 476static void ssh2_channel_check_close(struct ssh_channel *c);
bc06669b 477static void ssh_channel_destroy(struct ssh_channel *c);
3d63ca2e 478
5471d09a 479/*
480 * Buffer management constants. There are several of these for
481 * various different purposes:
482 *
483 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
484 * on a local data stream before we throttle the whole SSH
2e85c969 485 * connection (in SSH-1 only). Throttling the whole connection is
5471d09a 486 * pretty drastic so we set this high in the hope it won't
487 * happen very often.
488 *
489 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
490 * on the SSH connection itself before we defensively throttle
491 * _all_ local data streams. This is pretty drastic too (though
2e85c969 492 * thankfully unlikely in SSH-2 since the window mechanism should
5471d09a 493 * ensure that the server never has any need to throttle its end
494 * of the connection), so we set this high as well.
495 *
2e85c969 496 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
5471d09a 497 * channels.
9b53e9b8 498 *
499 * - OUR_V2_BIGWIN is the window size we advertise for the only
3361b80a 500 * channel in a simple connection. It must be <= INT_MAX.
9916cc1e 501 *
502 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
503 * to the remote side. This actually has nothing to do with the
504 * size of the _packet_, but is instead a limit on the amount
505 * of data we're willing to receive in a single SSH2 channel
506 * data message.
507 *
508 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
509 * _packet_ we're prepared to cope with. It must be a multiple
510 * of the cipher block size, and must be at least 35000.
5471d09a 511 */
512
513#define SSH1_BUFFER_LIMIT 32768
514#define SSH_MAX_BACKLOG 32768
515#define OUR_V2_WINSIZE 16384
3361b80a 516#define OUR_V2_BIGWIN 0x7fffffff
954d5c5a 517#define OUR_V2_MAXPKT 0x4000UL
9916cc1e 518#define OUR_V2_PACKETLIMIT 0x9000UL
d74d141c 519
85cc02bb 520const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 521
8b2715b2 522const static struct ssh_mac *macs[] = {
6668a75e 523 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
32874aea 524};
8b2715b2 525const static struct ssh_mac *buggymacs[] = {
6668a75e 526 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
32874aea 527};
e5574168 528
5366aed8 529static void *ssh_comp_none_init(void)
530{
531 return NULL;
532}
533static void ssh_comp_none_cleanup(void *handle)
32874aea 534{
535}
5366aed8 536static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 537 unsigned char **outblock, int *outlen)
538{
539 return 0;
540}
5366aed8 541static int ssh_comp_none_disable(void *handle)
32874aea 542{
4ba9b64b 543 return 0;
544}
57476f6b 545const static struct ssh_compress ssh_comp_none = {
ab18ccff 546 "none", NULL,
5366aed8 547 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
548 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
549 ssh_comp_none_disable, NULL
e5574168 550};
4ba9b64b 551extern const struct ssh_compress ssh_zlib;
552const static struct ssh_compress *compressions[] = {
32874aea 553 &ssh_zlib, &ssh_comp_none
554};
374330e2 555
32874aea 556enum { /* channel types */
783415f8 557 CHAN_MAINSESSION,
558 CHAN_X11,
559 CHAN_AGENT,
bc240b21 560 CHAN_SOCKDATA,
c6b41791 561 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
562 /*
563 * CHAN_ZOMBIE is used to indicate a channel for which we've
564 * already destroyed the local data source: for instance, if a
565 * forwarded port experiences a socket error on the local side, we
566 * immediately destroy its local socket and turn the SSH channel
567 * into CHAN_ZOMBIE.
568 */
569 CHAN_ZOMBIE
783415f8 570};
571
dacbd0e8 572/*
0e443c99 573 * little structure to keep track of outstanding WINDOW_ADJUSTs
574 */
575struct winadj {
576 struct winadj *next;
577 unsigned size;
578};
579
580/*
dacbd0e8 581 * 2-3-4 tree storing channels.
582 */
583struct ssh_channel {
51470298 584 Ssh ssh; /* pointer back to main context */
d211621f 585 unsigned remoteid, localid;
dacbd0e8 586 int type;
64d6ff88 587 /* True if we opened this channel but server hasn't confirmed. */
588 int halfopen;
0357890f 589 /*
2e85c969 590 * In SSH-1, this value contains four bits:
0357890f 591 *
592 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
593 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
594 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
595 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
596 *
597 * A channel is completely finished with when all four bits are set.
bc06669b 598 *
599 * In SSH-2, the four bits mean:
600 *
601 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
602 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
603 * 4 We have received SSH2_MSG_CHANNEL_EOF.
604 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
605 *
606 * A channel is completely finished with when we have both sent
607 * and received CLOSE.
608 *
609 * The symbolic constants below use the SSH-2 terminology, which
610 * is a bit confusing in SSH-1, but we have to use _something_.
0357890f 611 */
bc06669b 612#define CLOSES_SENT_EOF 1
613#define CLOSES_SENT_CLOSE 2
614#define CLOSES_RCVD_EOF 4
615#define CLOSES_RCVD_CLOSE 8
dacbd0e8 616 int closes;
78280721 617
618 /*
bc06669b 619 * This flag indicates that an EOF is pending on the outgoing side
620 * of the channel: that is, wherever we're getting the data for
621 * this channel has sent us some data followed by EOF. We can't
622 * actually send the EOF until we've finished sending the data, so
623 * we set this flag instead to remind us to do so once our buffer
624 * is clear.
78280721 625 */
bc06669b 626 int pending_eof;
78280721 627
ff68564b 628 /*
629 * True if this channel is causing the underlying connection to be
630 * throttled.
631 */
632 int throttling_conn;
5471d09a 633 union {
5471d09a 634 struct ssh2_data_channel {
635 bufchain outbuffer;
636 unsigned remwindow, remmaxpkt;
467e064d 637 /* locwindow is signed so we can cope with excess data. */
9b53e9b8 638 int locwindow, locmaxwin;
0e443c99 639 /*
640 * remlocwin is the amount of local window that we think
641 * the remote end had available to it after it sent the
642 * last data packet or window adjust ack.
643 */
644 int remlocwin;
645 /*
646 * These store the list of window adjusts that haven't
647 * been acked.
648 */
649 struct winadj *winadj_head, *winadj_tail;
650 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
5471d09a 651 } v2;
652 } v;
dacbd0e8 653 union {
32874aea 654 struct ssh_agent_channel {
655 unsigned char *message;
656 unsigned char msglen[4];
a03c9f9c 657 unsigned lensofar, totallen;
32874aea 658 } a;
659 struct ssh_x11_channel {
660 Socket s;
661 } x11;
d74d141c 662 struct ssh_pfd_channel {
663 Socket s;
664 } pfd;
dacbd0e8 665 } u;
666};
57476f6b 667
d74d141c 668/*
2e85c969 669 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
670 * use this structure in different ways, reflecting SSH-2's
bc240b21 671 * altogether saner approach to port forwarding.
672 *
2e85c969 673 * In SSH-1, you arrange a remote forwarding by sending the server
bc240b21 674 * the remote port number, and the local destination host:port.
675 * When a connection comes in, the server sends you back that
676 * host:port pair, and you connect to it. This is a ready-made
677 * security hole if you're not on the ball: a malicious server
678 * could send you back _any_ host:port pair, so if you trustingly
679 * connect to the address it gives you then you've just opened the
680 * entire inside of your corporate network just by connecting
681 * through it to a dodgy SSH server. Hence, we must store a list of
682 * host:port pairs we _are_ trying to forward to, and reject a
683 * connection request from the server if it's not in the list.
684 *
2e85c969 685 * In SSH-2, each side of the connection minds its own business and
bc240b21 686 * doesn't send unnecessary information to the other. You arrange a
687 * remote forwarding by sending the server just the remote port
688 * number. When a connection comes in, the server tells you which
689 * of its ports was connected to; and _you_ have to remember what
690 * local host:port pair went with that port number.
691 *
2e85c969 692 * Hence, in SSH-1 this structure is indexed by destination
693 * host:port pair, whereas in SSH-2 it is indexed by source port.
d74d141c 694 */
fda2feb1 695struct ssh_portfwd; /* forward declaration */
696
d74d141c 697struct ssh_rportfwd {
bc240b21 698 unsigned sport, dport;
699 char dhost[256];
06fadff5 700 char *sportdesc;
fda2feb1 701 struct ssh_portfwd *pfrec;
d74d141c 702};
fda2feb1 703#define free_rportfwd(pf) ( \
704 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
705
706/*
707 * Separately to the rportfwd tree (which is for looking up port
708 * open requests from the server), a tree of _these_ structures is
709 * used to keep track of all the currently open port forwardings,
710 * so that we can reconfigure in mid-session if the user requests
711 * it.
712 */
713struct ssh_portfwd {
84328ddb 714 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 715 int type;
716 unsigned sport, dport;
717 char *saddr, *daddr;
3fe92132 718 char *sserv, *dserv;
fda2feb1 719 struct ssh_rportfwd *remote;
05581745 720 int addressfamily;
fda2feb1 721 void *local;
722};
723#define free_portfwd(pf) ( \
3fe92132 724 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
725 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 726
57476f6b 727struct Packet {
dacd8872 728 long length; /* length of `data' actually used */
729 long forcepad; /* SSH-2: force padding to at least this length */
730 int type; /* only used for incoming packets */
731 unsigned long sequence; /* SSH-2 incoming sequence number */
732 unsigned char *data; /* allocated storage */
733 unsigned char *body; /* offset of payload within `data' */
734 long savedpos; /* temporary index into `data' (for strings) */
735 long maxlen; /* amount of storage allocated for `data' */
736 long encrypted_len; /* for SSH-2 total-size counting */
ff3187f6 737
738 /*
739 * State associated with packet logging
740 */
741 int logmode;
742 int nblanks;
743 struct logblank_t *blanks;
57476f6b 744};
745
1c1a7262 746static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 747 struct Packet *pktin);
1c1a7262 748static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 749 struct Packet *pktin);
b09eaa88 750static void ssh1_protocol_setup(Ssh ssh);
751static void ssh2_protocol_setup(Ssh ssh);
51470298 752static void ssh_size(void *handle, int width, int height);
753static void ssh_special(void *handle, Telnet_Special);
5471d09a 754static int ssh2_try_send(struct ssh_channel *c);
51470298 755static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
756static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
9fca3f8c 757static void ssh2_set_window(struct ssh_channel *c, int newwin);
51470298 758static int ssh_sendbuffer(void *handle);
ac934965 759static int ssh_do_close(Ssh ssh, int notify_exit);
ff3187f6 760static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
761static int ssh2_pkt_getbool(struct Packet *pkt);
762static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 763static void ssh2_timer(void *ctx, long now);
1c1a7262 764static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
9442dd57 765 struct Packet *pktin);
57476f6b 766
51470298 767struct rdpkt1_state_tag {
57476f6b 768 long len, pad, biglen, to_read;
769 unsigned long realcrc, gotcrc;
770 unsigned char *p;
771 int i;
772 int chunk;
ff3187f6 773 struct Packet *pktin;
51470298 774};
57476f6b 775
51470298 776struct rdpkt2_state_tag {
960e736a 777 long len, pad, payload, packetlen, maclen;
778 int i;
779 int cipherblk;
780 unsigned long incoming_sequence;
ff3187f6 781 struct Packet *pktin;
51470298 782};
783
b09eaa88 784typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 785typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
786
787struct queued_handler;
788struct queued_handler {
789 int msg1, msg2;
790 chandler_fn_t handler;
791 void *ctx;
792 struct queued_handler *next;
793};
b09eaa88 794
51470298 795struct ssh_tag {
796 const struct plug_function_table *fn;
797 /* the above field _must_ be first in the structure */
798
4320baf7 799 char *v_c, *v_s;
b672f405 800 void *exhash;
51470298 801
802 Socket s;
803
b9d7bcad 804 void *ldisc;
a8327734 805 void *logctx;
b9d7bcad 806
51470298 807 unsigned char session_key[32];
808 int v1_compressing;
809 int v1_remote_protoflags;
810 int v1_local_protoflags;
811 int agentfwd_enabled;
812 int X11_fwd_enabled;
813 int remote_bugs;
814 const struct ssh_cipher *cipher;
371e569c 815 void *v1_cipher_ctx;
0183b242 816 void *crcda_ctx;
51470298 817 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 818 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 819 const struct ssh_mac *csmac, *scmac;
e0e1a00d 820 void *cs_mac_ctx, *sc_mac_ctx;
51470298 821 const struct ssh_compress *cscomp, *sccomp;
5366aed8 822 void *cs_comp_ctx, *sc_comp_ctx;
51470298 823 const struct ssh_kex *kex;
824 const struct ssh_signkey *hostkey;
754c0df9 825 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
b672f405 826 int v2_session_id_len;
27cd7fc2 827 void *kex_ctx;
51470298 828
829 char *savedhost;
830 int savedport;
831 int send_ok;
832 int echoing, editing;
833
834 void *frontend;
835
db219738 836 int ospeed, ispeed; /* temporaries */
51470298 837 int term_width, term_height;
838
839 tree234 *channels; /* indexed by local id */
840 struct ssh_channel *mainchan; /* primary session channel */
feb02b4e 841 int ncmode; /* is primary channel direct-tcpip? */
51470298 842 int exitcode;
ac934965 843 int close_expected;
9e296bfa 844 int clean_exit;
51470298 845
fda2feb1 846 tree234 *rportfwds, *portfwds;
51470298 847
848 enum {
849 SSH_STATE_PREPACKET,
850 SSH_STATE_BEFORE_SIZE,
851 SSH_STATE_INTERMED,
852 SSH_STATE_SESSION,
853 SSH_STATE_CLOSED
854 } state;
855
856 int size_needed, eof_needed;
bc06669b 857 int sent_console_eof;
4a202fc6 858 int got_pty; /* affects EOF behaviour on main channel */
51470298 859
590f6a5f 860 struct Packet **queue;
861 int queuelen, queuesize;
862 int queueing;
51470298 863 unsigned char *deferred_send_data;
864 int deferred_len, deferred_size;
865
866 /*
867 * Gross hack: pscp will try to start SFTP but fall back to
868 * scp1 if that fails. This variable is the means by which
869 * scp.c can reach into the SSH code and find out which one it
870 * got.
871 */
872 int fallback_cmd;
873
6bbce591 874 bufchain banner; /* accumulates banners during do_ssh2_authconn */
51470298 875
acab36bc 876 Pkt_KCtx pkt_kctx;
877 Pkt_ACtx pkt_actx;
51470298 878
8def70c3 879 struct X11Display *x11disp;
302121de 880
51470298 881 int version;
ff68564b 882 int conn_throttle_count;
51470298 883 int overall_bufsize;
884 int throttled_all;
885 int v1_stdout_throttling;
a8756193 886 unsigned long v2_outgoing_sequence;
51470298 887
888 int ssh1_rdpkt_crstate;
889 int ssh2_rdpkt_crstate;
890 int do_ssh_init_crstate;
891 int ssh_gotdata_crstate;
51470298 892 int do_ssh1_login_crstate;
b09eaa88 893 int do_ssh1_connection_crstate;
51470298 894 int do_ssh2_transport_crstate;
895 int do_ssh2_authconn_crstate;
896
897 void *do_ssh_init_state;
898 void *do_ssh1_login_state;
899 void *do_ssh2_transport_state;
900 void *do_ssh2_authconn_state;
901
902 struct rdpkt1_state_tag rdpkt1_state;
903 struct rdpkt2_state_tag rdpkt2_state;
904
2e85c969 905 /* SSH-1 and SSH-2 use this for different things, but both use it */
b09eaa88 906 int protocol_initial_phase_done;
907
1c1a7262 908 void (*protocol) (Ssh ssh, void *vin, int inlen,
ff3187f6 909 struct Packet *pkt);
910 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 911
912 /*
4a693cfc 913 * We maintain our own copy of a Conf structure here. That way,
914 * when we're passed a new one for reconfiguration, we can check
915 * the differences and potentially reconfigure port forwardings
916 * etc in mid-session.
86916870 917 */
4a693cfc 918 Conf *conf;
919
920 /*
921 * Values cached out of conf so as to avoid the tree234 lookup
922 * cost every time they're used.
923 */
924 int logomitdata;
925
926 /*
927 * Dynamically allocated username string created during SSH
928 * login. Stored in here rather than in the coroutine state so
929 * that it'll be reliably freed if we shut down the SSH session
930 * at some unexpected moment.
931 */
932 char *username;
839f10db 933
934 /*
3d9449a1 935 * Used to transfer data back from async callbacks.
839f10db 936 */
937 void *agent_response;
938 int agent_response_len;
3d9449a1 939 int user_response;
940
941 /*
942 * The SSH connection can be set as `frozen', meaning we are
943 * not currently accepting incoming data from the network. This
944 * is slightly more serious than setting the _socket_ as
945 * frozen, because we may already have had data passed to us
946 * from the network which we need to delay processing until
947 * after the freeze is lifted, so we also need a bufchain to
948 * store that data.
949 */
950 int frozen;
951 bufchain queued_incoming_data;
b09eaa88 952
953 /*
954 * Dispatch table for packet types that we may have to deal
955 * with at any time.
956 */
957 handler_fn_t packet_dispatch[256];
39934deb 958
959 /*
06fadff5 960 * Queues of one-off handler functions for success/failure
961 * indications from a request.
962 */
963 struct queued_handler *qhead, *qtail;
964
965 /*
39934deb 966 * This module deals with sending keepalives.
967 */
968 Pinger pinger;
9442dd57 969
970 /*
971 * Track incoming and outgoing data sizes and time, for
972 * size-based rekeys.
973 */
974 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 975 unsigned long max_data_size;
9442dd57 976 int kex_in_progress;
e6c1536e 977 long next_rekey, last_rekey;
e13bba36 978 char *deferred_rekey_reason; /* points to STATIC string; don't free */
42af6a67 979
980 /*
981 * Fully qualified host name, which we need if doing GSSAPI.
982 */
983 char *fullhostname;
1e00c92b 984
985#ifndef NO_GSSAPI
986 /*
987 * GSSAPI libraries for this session.
988 */
989 struct ssh_gss_liblist *gsslibs;
990#endif
51470298 991};
960e736a 992
382908ad 993#define logevent(s) logevent(ssh->frontend, s)
a8327734 994
995/* logevent, only printf-formatted. */
cbe2d68f 996static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 997{
998 va_list ap;
57356d63 999 char *buf;
a8327734 1000
1001 va_start(ap, fmt);
57356d63 1002 buf = dupvprintf(fmt, ap);
a8327734 1003 va_end(ap);
57356d63 1004 logevent(buf);
57356d63 1005 sfree(buf);
a8327734 1006}
1007
6b5cf8b4 1008#define bombout(msg) \
1009 do { \
1010 char *text = dupprintf msg; \
ac934965 1011 ssh_do_close(ssh, FALSE); \
6b5cf8b4 1012 logevent(text); \
1013 connection_fatal(ssh->frontend, "%s", text); \
1014 sfree(text); \
1015 } while (0)
a8327734 1016
9a10ecf4 1017/* Functions to leave bits out of the SSH packet log file. */
1018
ff3187f6 1019static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1020{
4a693cfc 1021 if (conf_get_int(ssh->conf, CONF_logomitpass))
ff3187f6 1022 pkt->logmode = blanktype;
9a10ecf4 1023}
1024
ff3187f6 1025static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 1026{
4a693cfc 1027 if (ssh->logomitdata)
ff3187f6 1028 pkt->logmode = blanktype;
9a10ecf4 1029}
1030
ff3187f6 1031static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 1032{
ff3187f6 1033 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 1034}
1035
4a693cfc 1036/* Helper function for common bits of parsing ttymodes. */
1037static void parse_ttymodes(Ssh ssh,
c6ccd5c2 1038 void (*do_mode)(void *data, char *mode, char *val),
1039 void *data)
1040{
4a693cfc 1041 char *key, *val;
1042
1043 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1044 val != NULL;
1045 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1046 /*
1047 * val[0] is either 'V', indicating that an explicit value
1048 * follows it, or 'A' indicating that we should pass the
1049 * value through from the local environment via get_ttymode.
1050 */
1051 if (val[0] == 'A')
1052 val = get_ttymode(ssh->frontend, key);
c6ccd5c2 1053 else
4a693cfc 1054 val++; /* skip the 'V' */
c6ccd5c2 1055 if (val)
4a693cfc 1056 do_mode(data, key, val);
c6ccd5c2 1057 }
1058}
1059
32874aea 1060static int ssh_channelcmp(void *av, void *bv)
1061{
1062 struct ssh_channel *a = (struct ssh_channel *) av;
1063 struct ssh_channel *b = (struct ssh_channel *) bv;
1064 if (a->localid < b->localid)
1065 return -1;
1066 if (a->localid > b->localid)
1067 return +1;
dacbd0e8 1068 return 0;
1069}
32874aea 1070static int ssh_channelfind(void *av, void *bv)
1071{
1072 unsigned *a = (unsigned *) av;
1073 struct ssh_channel *b = (struct ssh_channel *) bv;
1074 if (*a < b->localid)
1075 return -1;
1076 if (*a > b->localid)
1077 return +1;
dacbd0e8 1078 return 0;
1079}
1080
bc240b21 1081static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 1082{
1083 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1084 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1085 int i;
bc240b21 1086 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 1087 return i < 0 ? -1 : +1;
bc240b21 1088 if (a->dport > b->dport)
1089 return +1;
1090 if (a->dport < b->dport)
1091 return -1;
1092 return 0;
1093}
1094
1095static int ssh_rportcmp_ssh2(void *av, void *bv)
1096{
1097 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1098 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 1099
bc240b21 1100 if (a->sport > b->sport)
d74d141c 1101 return +1;
bc240b21 1102 if (a->sport < b->sport)
1103 return -1;
d74d141c 1104 return 0;
1105}
1106
fda2feb1 1107/*
1108 * Special form of strcmp which can cope with NULL inputs. NULL is
1109 * defined to sort before even the empty string.
1110 */
1111static int nullstrcmp(const char *a, const char *b)
1112{
1113 if (a == NULL && b == NULL)
1114 return 0;
1115 if (a == NULL)
1116 return -1;
1117 if (b == NULL)
1118 return +1;
1119 return strcmp(a, b);
1120}
1121
1122static int ssh_portcmp(void *av, void *bv)
1123{
1124 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1125 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1126 int i;
1127 if (a->type > b->type)
1128 return +1;
1129 if (a->type < b->type)
1130 return -1;
84328ddb 1131 if (a->addressfamily > b->addressfamily)
1132 return +1;
1133 if (a->addressfamily < b->addressfamily)
1134 return -1;
fda2feb1 1135 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1136 return i < 0 ? -1 : +1;
1137 if (a->sport > b->sport)
1138 return +1;
1139 if (a->sport < b->sport)
1140 return -1;
1141 if (a->type != 'D') {
1142 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1143 return i < 0 ? -1 : +1;
1144 if (a->dport > b->dport)
1145 return +1;
1146 if (a->dport < b->dport)
1147 return -1;
1148 }
1149 return 0;
1150}
1151
51470298 1152static int alloc_channel_id(Ssh ssh)
32874aea 1153{
260f3dec 1154 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1155 unsigned low, high, mid;
d2371c81 1156 int tsize;
1157 struct ssh_channel *c;
1158
1159 /*
1160 * First-fit allocation of channel numbers: always pick the
1161 * lowest unused one. To do this, binary-search using the
1162 * counted B-tree to find the largest channel ID which is in a
1163 * contiguous sequence from the beginning. (Precisely
1164 * everything in that sequence must have ID equal to its tree
1165 * index plus CHANNEL_NUMBER_OFFSET.)
1166 */
51470298 1167 tsize = count234(ssh->channels);
d2371c81 1168
32874aea 1169 low = -1;
1170 high = tsize;
d2371c81 1171 while (high - low > 1) {
1172 mid = (high + low) / 2;
51470298 1173 c = index234(ssh->channels, mid);
d2371c81 1174 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1175 low = mid; /* this one is fine */
1176 else
1177 high = mid; /* this one is past it */
1178 }
1179 /*
1180 * Now low points to either -1, or the tree index of the
1181 * largest ID in the initial sequence.
1182 */
1183 {
1184 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 1185 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 1186 }
1187 return low + 1 + CHANNEL_NUMBER_OFFSET;
1188}
1189
edd0cb8a 1190static void c_write_stderr(int trusted, const char *buf, int len)
1191{
1192 int i;
1193 for (i = 0; i < len; i++)
667deca9 1194 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
edd0cb8a 1195 fputc(buf[i], stderr);
1196}
1197
9fab77dc 1198static void c_write(Ssh ssh, const char *buf, int len)
32874aea 1199{
edd0cb8a 1200 if (flags & FLAG_STDERR)
1201 c_write_stderr(1, buf, len);
1202 else
1203 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 1204}
1205
9fab77dc 1206static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 1207{
edd0cb8a 1208 if (flags & FLAG_STDERR)
1209 c_write_stderr(0, buf, len);
1210 else
1211 from_backend_untrusted(ssh->frontend, buf, len);
a209e957 1212}
1213
9fab77dc 1214static void c_write_str(Ssh ssh, const char *buf)
32874aea 1215{
51470298 1216 c_write(ssh, buf, strlen(buf));
1408a877 1217}
1218
ff3187f6 1219static void ssh_free_packet(struct Packet *pkt)
1220{
1221 sfree(pkt->data);
1222 sfree(pkt);
1223}
1224static struct Packet *ssh_new_packet(void)
1225{
1226 struct Packet *pkt = snew(struct Packet);
1227
dacd8872 1228 pkt->body = pkt->data = NULL;
ff3187f6 1229 pkt->maxlen = 0;
1230 pkt->logmode = PKTLOG_EMIT;
1231 pkt->nblanks = 0;
1232 pkt->blanks = NULL;
1233
1234 return pkt;
1235}
1236
fb09bf1c 1237/*
1238 * Collect incoming data in the incoming packet buffer.
e5574168 1239 * Decipher and verify the packet when it is completely read.
1240 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 1241 * Update the *data and *datalen variables.
ff3187f6 1242 * Return a Packet structure when a packet is completed.
fb09bf1c 1243 */
ff3187f6 1244static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 1245{
51470298 1246 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 1247
51470298 1248 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 1249
ff3187f6 1250 st->pktin = ssh_new_packet();
1251
1252 st->pktin->type = 0;
1253 st->pktin->length = 0;
374330e2 1254
57476f6b 1255 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 1256 while ((*datalen) == 0)
ff3187f6 1257 crReturn(NULL);
57476f6b 1258 st->len = (st->len << 8) + **data;
fb09bf1c 1259 (*data)++, (*datalen)--;
1260 }
374330e2 1261
57476f6b 1262 st->pad = 8 - (st->len % 8);
1263 st->biglen = st->len + st->pad;
ff3187f6 1264 st->pktin->length = st->len - 5;
fb09bf1c 1265
ae0500e5 1266 if (st->biglen < 0) {
1267 bombout(("Extremely large packet length from server suggests"
1268 " data stream corruption"));
ff3187f6 1269 ssh_free_packet(st->pktin);
1270 crStop(NULL);
ae0500e5 1271 }
1272
ff3187f6 1273 st->pktin->maxlen = st->biglen;
1274 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1275
57476f6b 1276 st->to_read = st->biglen;
ff3187f6 1277 st->p = st->pktin->data;
57476f6b 1278 while (st->to_read > 0) {
32874aea 1279 st->chunk = st->to_read;
fb09bf1c 1280 while ((*datalen) == 0)
ff3187f6 1281 crReturn(NULL);
57476f6b 1282 if (st->chunk > (*datalen))
1283 st->chunk = (*datalen);
1284 memcpy(st->p, *data, st->chunk);
1285 *data += st->chunk;
1286 *datalen -= st->chunk;
1287 st->p += st->chunk;
1288 st->to_read -= st->chunk;
fb09bf1c 1289 }
374330e2 1290
ff3187f6 1291 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1292 st->biglen, NULL)) {
6b5cf8b4 1293 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1294 ssh_free_packet(st->pktin);
1295 crStop(NULL);
9a3a93a5 1296 }
1297
51470298 1298 if (ssh->cipher)
ff3187f6 1299 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1300
ff3187f6 1301 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1302 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1303 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1304 bombout(("Incorrect CRC received on packet"));
ff3187f6 1305 ssh_free_packet(st->pktin);
1306 crStop(NULL);
fb09bf1c 1307 }
572f871e 1308
ff3187f6 1309 st->pktin->body = st->pktin->data + st->pad + 1;
1310 st->pktin->savedpos = 0;
4ba9b64b 1311
51470298 1312 if (ssh->v1_compressing) {
4ba9b64b 1313 unsigned char *decompblk;
1314 int decomplen;
36b8d9bb 1315 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1316 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1317 &decompblk, &decomplen)) {
1318 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1319 ssh_free_packet(st->pktin);
1320 crStop(NULL);
36b8d9bb 1321 }
4ba9b64b 1322
ff3187f6 1323 if (st->pktin->maxlen < st->pad + decomplen) {
1324 st->pktin->maxlen = st->pad + decomplen;
1325 st->pktin->data = sresize(st->pktin->data,
1326 st->pktin->maxlen + APIEXTRA,
3d88e64d 1327 unsigned char);
ff3187f6 1328 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1329 }
1330
ff3187f6 1331 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1332 sfree(decompblk);
ff3187f6 1333 st->pktin->length = decomplen - 1;
4ba9b64b 1334 }
1335
ff3187f6 1336 st->pktin->type = st->pktin->body[-1];
00db133f 1337
9a10ecf4 1338 /*
1339 * Log incoming packet, possibly omitting sensitive fields.
1340 */
1341 if (ssh->logctx) {
1342 int nblanks = 0;
1343 struct logblank_t blank;
4a693cfc 1344 if (ssh->logomitdata) {
9a10ecf4 1345 int do_blank = FALSE, blank_prefix = 0;
1346 /* "Session data" packets - omit the data field */
ff3187f6 1347 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1348 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1349 do_blank = TRUE; blank_prefix = 4;
a2724fba 1350 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1351 do_blank = TRUE; blank_prefix = 8;
9a10ecf4 1352 }
1353 if (do_blank) {
1354 blank.offset = blank_prefix;
ff3187f6 1355 blank.len = st->pktin->length;
9a10ecf4 1356 blank.type = PKTLOG_OMIT;
1357 nblanks = 1;
1358 }
1359 }
a8327734 1360 log_packet(ssh->logctx,
ff3187f6 1361 PKT_INCOMING, st->pktin->type,
1362 ssh1_pkt_type(st->pktin->type),
1363 st->pktin->body, st->pktin->length,
0d13bfcd 1364 nblanks, &blank, NULL);
9a10ecf4 1365 }
00db133f 1366
ff3187f6 1367 crFinish(st->pktin);
fb09bf1c 1368}
1369
ff3187f6 1370static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1371{
51470298 1372 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1373
51470298 1374 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1375
ff3187f6 1376 st->pktin = ssh_new_packet();
1377
1378 st->pktin->type = 0;
1379 st->pktin->length = 0;
51470298 1380 if (ssh->sccipher)
1381 st->cipherblk = ssh->sccipher->blksize;
e5574168 1382 else
32874aea 1383 st->cipherblk = 8;
960e736a 1384 if (st->cipherblk < 8)
32874aea 1385 st->cipherblk = 8;
9916cc1e 1386 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
960e736a 1387
9916cc1e 1388 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1389 ssh->scmac) {
1390 /*
1391 * When dealing with a CBC-mode cipher, we want to avoid the
1392 * possibility of an attacker's tweaking the ciphertext stream
1393 * so as to cause us to feed the same block to the block
1394 * cipher more than once and thus leak information
1395 * (VU#958563). The way we do this is not to take any
1396 * decisions on the basis of anything we've decrypted until
1397 * we've verified it with a MAC. That includes the packet
1398 * length, so we just read data and check the MAC repeatedly,
1399 * and when the MAC passes, see if the length we've got is
1400 * plausible.
1401 */
1402
1403 /* May as well allocate the whole lot now. */
1404 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1405 unsigned char);
1406
1407 /* Read an amount corresponding to the MAC. */
1408 for (st->i = 0; st->i < st->maclen; st->i++) {
1409 while ((*datalen) == 0)
1410 crReturn(NULL);
1411 st->pktin->data[st->i] = *(*data)++;
1412 (*datalen)--;
1413 }
e5574168 1414
9916cc1e 1415 st->packetlen = 0;
1416 {
1417 unsigned char seq[4];
1418 ssh->scmac->start(ssh->sc_mac_ctx);
1419 PUT_32BIT(seq, st->incoming_sequence);
1420 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1421 }
4252c9cc 1422
9916cc1e 1423 for (;;) { /* Once around this loop per cipher block. */
1424 /* Read another cipher-block's worth, and tack it onto the end. */
1425 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1426 while ((*datalen) == 0)
1427 crReturn(NULL);
1428 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1429 (*datalen)--;
1430 }
1431 /* Decrypt one more block (a little further back in the stream). */
1432 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1433 st->pktin->data + st->packetlen,
1434 st->cipherblk);
1435 /* Feed that block to the MAC. */
1436 ssh->scmac->bytes(ssh->sc_mac_ctx,
1437 st->pktin->data + st->packetlen, st->cipherblk);
1438 st->packetlen += st->cipherblk;
1439 /* See if that gives us a valid packet. */
1440 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1441 st->pktin->data + st->packetlen) &&
1442 (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen)
1443 break;
1444 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1445 bombout(("No valid incoming packet found"));
1446 ssh_free_packet(st->pktin);
1447 crStop(NULL);
1448 }
1449 }
1450 st->pktin->maxlen = st->packetlen + st->maclen;
1451 st->pktin->data = sresize(st->pktin->data,
1452 st->pktin->maxlen + APIEXTRA,
1453 unsigned char);
1454 } else {
1455 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1456
1457 /*
1458 * Acquire and decrypt the first block of the packet. This will
1459 * contain the length and padding details.
1460 */
1461 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1462 while ((*datalen) == 0)
1463 crReturn(NULL);
1464 st->pktin->data[st->i] = *(*data)++;
1465 (*datalen)--;
1466 }
e5574168 1467
9916cc1e 1468 if (ssh->sccipher)
1469 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1470 st->pktin->data, st->cipherblk);
1471
1472 /*
1473 * Now get the length figure.
1474 */
1475 st->len = GET_32BIT(st->pktin->data);
1476
1477 /*
1478 * _Completely_ silly lengths should be stomped on before they
1479 * do us any more damage.
1480 */
1481 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1482 (st->len + 4) % st->cipherblk != 0) {
1483 bombout(("Incoming packet was garbled on decryption"));
1484 ssh_free_packet(st->pktin);
1485 crStop(NULL);
1486 }
e5574168 1487
9916cc1e 1488 /*
1489 * So now we can work out the total packet length.
1490 */
1491 st->packetlen = st->len + 4;
1492
1493 /*
1494 * Allocate memory for the rest of the packet.
1495 */
1496 st->pktin->maxlen = st->packetlen + st->maclen;
1497 st->pktin->data = sresize(st->pktin->data,
1498 st->pktin->maxlen + APIEXTRA,
1499 unsigned char);
1500
1501 /*
1502 * Read and decrypt the remainder of the packet.
1503 */
1504 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1505 st->i++) {
1506 while ((*datalen) == 0)
1507 crReturn(NULL);
1508 st->pktin->data[st->i] = *(*data)++;
1509 (*datalen)--;
1510 }
1511 /* Decrypt everything _except_ the MAC. */
1512 if (ssh->sccipher)
1513 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1514 st->pktin->data + st->cipherblk,
1515 st->packetlen - st->cipherblk);
1516
1517 /*
1518 * Check the MAC.
1519 */
1520 if (ssh->scmac
1521 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1522 st->len + 4, st->incoming_sequence)) {
1523 bombout(("Incorrect MAC received on packet"));
1524 ssh_free_packet(st->pktin);
1525 crStop(NULL);
1526 }
1527 }
1528 /* Get and sanity-check the amount of random padding. */
1529 st->pad = st->pktin->data[4];
1530 if (st->pad < 4 || st->len - st->pad < 1) {
1531 bombout(("Invalid padding length on received packet"));
ff3187f6 1532 ssh_free_packet(st->pktin);
1533 crStop(NULL);
717dc483 1534 }
717dc483 1535 /*
e5574168 1536 * This enables us to deduce the payload length.
1537 */
960e736a 1538 st->payload = st->len - st->pad - 1;
e5574168 1539
ff3187f6 1540 st->pktin->length = st->payload + 5;
9442dd57 1541 st->pktin->encrypted_len = st->packetlen;
1542
b09eaa88 1543 st->pktin->sequence = st->incoming_sequence++;
e5574168 1544
4ba9b64b 1545 /*
1546 * Decompress packet payload.
1547 */
1548 {
1549 unsigned char *newpayload;
1550 int newlen;
51470298 1551 if (ssh->sccomp &&
5366aed8 1552 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1553 st->pktin->data + 5, st->pktin->length - 5,
51470298 1554 &newpayload, &newlen)) {
ff3187f6 1555 if (st->pktin->maxlen < newlen + 5) {
1556 st->pktin->maxlen = newlen + 5;
1557 st->pktin->data = sresize(st->pktin->data,
1558 st->pktin->maxlen + APIEXTRA,
3d88e64d 1559 unsigned char);
4ba9b64b 1560 }
ff3187f6 1561 st->pktin->length = 5 + newlen;
1562 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1563 sfree(newpayload);
4ba9b64b 1564 }
1565 }
1566
ff3187f6 1567 st->pktin->savedpos = 6;
1568 st->pktin->body = st->pktin->data;
1569 st->pktin->type = st->pktin->data[5];
e5574168 1570
9a10ecf4 1571 /*
1572 * Log incoming packet, possibly omitting sensitive fields.
1573 */
1574 if (ssh->logctx) {
1575 int nblanks = 0;
1576 struct logblank_t blank;
4a693cfc 1577 if (ssh->logomitdata) {
9a10ecf4 1578 int do_blank = FALSE, blank_prefix = 0;
1579 /* "Session data" packets - omit the data field */
ff3187f6 1580 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1581 do_blank = TRUE; blank_prefix = 8;
a2724fba 1582 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1583 do_blank = TRUE; blank_prefix = 12;
9a10ecf4 1584 }
1585 if (do_blank) {
1586 blank.offset = blank_prefix;
ff3187f6 1587 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1588 blank.type = PKTLOG_OMIT;
1589 nblanks = 1;
1590 }
1591 }
ff3187f6 1592 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
acab36bc 1593 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1594 st->pktin->type),
ff3187f6 1595 st->pktin->data+6, st->pktin->length-6,
0d13bfcd 1596 nblanks, &blank, &st->pktin->sequence);
9a10ecf4 1597 }
00db133f 1598
ff3187f6 1599 crFinish(st->pktin);
e5574168 1600}
1601
dacd8872 1602static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
32874aea 1603{
dacd8872 1604 int pad, biglen, i, pktoffs;
374330e2 1605 unsigned long crc;
fd7a4aad 1606#ifdef __SC__
1607 /*
1608 * XXX various versions of SC (including 8.8.4) screw up the
1609 * register allocation in this function and use the same register
1610 * (D6) for len and as a temporary, with predictable results. The
1611 * following sledgehammer prevents this.
1612 */
1613 volatile
1614#endif
1615 int len;
374330e2 1616
a8327734 1617 if (ssh->logctx)
dacd8872 1618 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1619 ssh1_pkt_type(pkt->data[12]),
1620 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1621 pkt->nblanks, pkt->blanks, NULL);
ff3187f6 1622 sfree(pkt->blanks); pkt->blanks = NULL;
1623 pkt->nblanks = 0;
00db133f 1624
51470298 1625 if (ssh->v1_compressing) {
4ba9b64b 1626 unsigned char *compblk;
1627 int complen;
5366aed8 1628 zlib_compress_block(ssh->cs_comp_ctx,
dacd8872 1629 pkt->data + 12, pkt->length - 12,
4ba9b64b 1630 &compblk, &complen);
48406e6b 1631 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
dacd8872 1632 memcpy(pkt->data + 12, compblk, complen);
dcbde236 1633 sfree(compblk);
dacd8872 1634 pkt->length = complen + 12;
4ba9b64b 1635 }
1636
dacd8872 1637 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1638 pkt->length += 4;
1639 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
32874aea 1640 pad = 8 - (len % 8);
dacd8872 1641 pktoffs = 8 - pad;
1642 biglen = len + pad; /* len(padding+type+data+CRC) */
374330e2 1643
dacd8872 1644 for (i = pktoffs; i < 4+8; i++)
1645 pkt->data[i] = random_byte();
1646 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1647 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1648 PUT_32BIT(pkt->data + pktoffs, len);
374330e2 1649
51470298 1650 if (ssh->cipher)
dacd8872 1651 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1652 pkt->data + pktoffs + 4, biglen);
374330e2 1653
dacd8872 1654 if (offset_p) *offset_p = pktoffs;
1655 return biglen + 4; /* len(length+padding+type+data+CRC) */
39065bed 1656}
1657
bf8a49a1 1658static int s_write(Ssh ssh, void *data, int len)
1659{
ff05dfef 1660 if (ssh->logctx)
0d13bfcd 1661 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1662 0, NULL, NULL);
bf8a49a1 1663 return sk_write(ssh->s, (char *)data, len);
1664}
1665
ff3187f6 1666static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1667{
dacd8872 1668 int len, backlog, offset;
1669 len = s_wrpkt_prepare(ssh, pkt, &offset);
bf8a49a1 1670 backlog = s_write(ssh, pkt->data + offset, len);
5471d09a 1671 if (backlog > SSH_MAX_BACKLOG)
51470298 1672 ssh_throttle_all(ssh, 1, backlog);
dacd8872 1673 ssh_free_packet(pkt);
39065bed 1674}
1675
ff3187f6 1676static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1677{
dacd8872 1678 int len, offset;
1679 len = s_wrpkt_prepare(ssh, pkt, &offset);
51470298 1680 if (ssh->deferred_len + len > ssh->deferred_size) {
1681 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1682 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1683 ssh->deferred_size,
1684 unsigned char);
39065bed 1685 }
dacd8872 1686 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1687 pkt->data + offset, len);
51470298 1688 ssh->deferred_len += len;
dacd8872 1689 ssh_free_packet(pkt);
374330e2 1690}
1691
fb09bf1c 1692/*
dacd8872 1693 * Construct a SSH-1 packet with the specified contents.
1694 * (This all-at-once interface used to be the only one, but now SSH-1
1695 * packets can also be constructed incrementally.)
fb09bf1c 1696 */
dacd8872 1697static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
fb09bf1c 1698{
dacd8872 1699 int argtype;
7cca0d81 1700 Bignum bn;
ff3187f6 1701 struct Packet *pkt;
fb09bf1c 1702
dacd8872 1703 pkt = ssh1_pkt_init(pkttype);
fb09bf1c 1704
dacd8872 1705 while ((argtype = va_arg(ap, int)) != PKT_END) {
1706 unsigned char *argp, argchar;
8a9977e5 1707 char *sargp;
dacd8872 1708 unsigned long argint;
1709 int arglen;
fb09bf1c 1710 switch (argtype) {
9a10ecf4 1711 /* Actual fields in the packet */
fb09bf1c 1712 case PKT_INT:
dacd8872 1713 argint = va_arg(ap, int);
1714 ssh_pkt_adduint32(pkt, argint);
fb09bf1c 1715 break;
1716 case PKT_CHAR:
dacd8872 1717 argchar = (unsigned char) va_arg(ap, int);
1718 ssh_pkt_addbyte(pkt, argchar);
fb09bf1c 1719 break;
1720 case PKT_DATA:
dacd8872 1721 argp = va_arg(ap, unsigned char *);
1722 arglen = va_arg(ap, int);
1723 ssh_pkt_adddata(pkt, argp, arglen);
fb09bf1c 1724 break;
1725 case PKT_STR:
8a9977e5 1726 sargp = va_arg(ap, char *);
1727 ssh_pkt_addstring(pkt, sargp);
fb09bf1c 1728 break;
7cca0d81 1729 case PKT_BIGNUM:
dacd8872 1730 bn = va_arg(ap, Bignum);
1731 ssh1_pkt_addmp(pkt, bn);
9a10ecf4 1732 break;
1733 /* Tokens for modifications to packet logging */
1734 case PKTT_PASSWORD:
ff3187f6 1735 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1736 break;
1737 case PKTT_DATA:
ff3187f6 1738 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1739 break;
9a10ecf4 1740 case PKTT_OTHER:
ff3187f6 1741 end_log_omission(ssh, pkt);
9a10ecf4 1742 break;
1743 }
fb09bf1c 1744 }
ff3187f6 1745
1746 return pkt;
39065bed 1747}
fb09bf1c 1748
51470298 1749static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1750{
ff3187f6 1751 struct Packet *pkt;
dacd8872 1752 va_list ap;
1753 va_start(ap, pkttype);
1754 pkt = construct_packet(ssh, pkttype, ap);
1755 va_end(ap);
ff3187f6 1756 s_wrpkt(ssh, pkt);
fb09bf1c 1757}
1758
51470298 1759static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1760{
ff3187f6 1761 struct Packet *pkt;
dacd8872 1762 va_list ap;
1763 va_start(ap, pkttype);
1764 pkt = construct_packet(ssh, pkttype, ap);
1765 va_end(ap);
ff3187f6 1766 s_wrpkt_defer(ssh, pkt);
39065bed 1767}
1768
32874aea 1769static int ssh_versioncmp(char *a, char *b)
1770{
9697bfd2 1771 char *ae, *be;
1772 unsigned long av, bv;
1773
43aa02a7 1774 av = strtoul(a, &ae, 10);
1775 bv = strtoul(b, &be, 10);
32874aea 1776 if (av != bv)
1777 return (av < bv ? -1 : +1);
1778 if (*ae == '.')
1779 ae++;
1780 if (*be == '.')
1781 be++;
43aa02a7 1782 av = strtoul(ae, &ae, 10);
1783 bv = strtoul(be, &be, 10);
32874aea 1784 if (av != bv)
1785 return (av < bv ? -1 : +1);
9697bfd2 1786 return 0;
1787}
1788
e5574168 1789/*
a92dd380 1790 * Utility routines for putting an SSH-protocol `string' and
b672f405 1791 * `uint32' into a hash state.
e5574168 1792 */
b672f405 1793static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
32874aea 1794{
e5574168 1795 unsigned char lenblk[4];
e5574168 1796 PUT_32BIT(lenblk, len);
b672f405 1797 h->bytes(s, lenblk, 4);
1798 h->bytes(s, str, len);
e5574168 1799}
1800
b672f405 1801static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
32874aea 1802{
a92dd380 1803 unsigned char intblk[4];
1804 PUT_32BIT(intblk, i);
b672f405 1805 h->bytes(s, intblk, 4);
a92dd380 1806}
1807
7cca0d81 1808/*
dacd8872 1809 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
7cca0d81 1810 */
dacd8872 1811static void ssh_pkt_ensure(struct Packet *pkt, int length)
32874aea 1812{
ff3187f6 1813 if (pkt->maxlen < length) {
dacd8872 1814 unsigned char *body = pkt->body;
3d71de0b 1815 int offset = body ? body - pkt->data : 0;
ff3187f6 1816 pkt->maxlen = length + 256;
1817 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
dacd8872 1818 if (body) pkt->body = pkt->data + offset;
7cca0d81 1819 }
783415f8 1820}
dacd8872 1821static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1822{
ff3187f6 1823 if (pkt->logmode != PKTLOG_EMIT) {
1824 pkt->nblanks++;
1825 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
dacd8872 1826 assert(pkt->body);
1827 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1828 (pkt->body - pkt->data);
ff3187f6 1829 pkt->blanks[pkt->nblanks-1].len = len;
1830 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1831 }
1832 pkt->length += len;
dacd8872 1833 ssh_pkt_ensure(pkt, pkt->length);
ff3187f6 1834 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1835}
dacd8872 1836static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1837{
dacd8872 1838 ssh_pkt_adddata(pkt, &byte, 1);
7cca0d81 1839}
ff3187f6 1840static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1841{
dacd8872 1842 ssh_pkt_adddata(pkt, &value, 1);
7cca0d81 1843}
dacd8872 1844static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1845{
7cca0d81 1846 unsigned char x[4];
1847 PUT_32BIT(x, value);
dacd8872 1848 ssh_pkt_adddata(pkt, x, 4);
7cca0d81 1849}
dacd8872 1850static void ssh_pkt_addstring_start(struct Packet *pkt)
32874aea 1851{
dacd8872 1852 ssh_pkt_adduint32(pkt, 0);
ff3187f6 1853 pkt->savedpos = pkt->length;
7cca0d81 1854}
dacd8872 1855static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1856{
dacd8872 1857 ssh_pkt_adddata(pkt, data, strlen(data));
ff3187f6 1858 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1859}
dacd8872 1860static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1861{
dacd8872 1862 ssh_pkt_adddata(pkt, data, len);
ff3187f6 1863 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1864}
dacd8872 1865static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1866{
1867 ssh_pkt_addstring_start(pkt);
1868 ssh_pkt_addstring_str(pkt, data);
1869}
1870static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1871{
dacd8872 1872 int len = ssh1_bignum_length(b);
8a9977e5 1873 unsigned char *data = snewn(len, unsigned char);
dacd8872 1874 (void) ssh1_write_bignum(data, b);
1875 ssh_pkt_adddata(pkt, data, len);
1876 sfree(data);
7cca0d81 1877}
d8baa528 1878static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1879{
7cca0d81 1880 unsigned char *p;
32874aea 1881 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1882 p = snewn(n + 1, unsigned char);
7cca0d81 1883 p[0] = 0;
3709bfe9 1884 for (i = 1; i <= n; i++)
32874aea 1885 p[i] = bignum_byte(b, n - i);
7cca0d81 1886 i = 0;
32874aea 1887 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1888 i++;
1889 memmove(p, p + i, n + 1 - i);
1890 *len = n + 1 - i;
7cca0d81 1891 return p;
1892}
ff3187f6 1893static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1894{
7cca0d81 1895 unsigned char *p;
1896 int len;
1897 p = ssh2_mpint_fmt(b, &len);
dacd8872 1898 ssh_pkt_addstring_start(pkt);
1899 ssh_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1900 sfree(p);
7cca0d81 1901}
b185170a 1902
dacd8872 1903static struct Packet *ssh1_pkt_init(int pkt_type)
1904{
1905 struct Packet *pkt = ssh_new_packet();
1906 pkt->length = 4 + 8; /* space for length + max padding */
1907 ssh_pkt_addbyte(pkt, pkt_type);
1908 pkt->body = pkt->data + pkt->length;
1909 return pkt;
1910}
1911
1912/* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1913#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1914#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1915#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1916#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1917#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1918#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1919#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1920#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1921
1922static struct Packet *ssh2_pkt_init(int pkt_type)
1923{
1924 struct Packet *pkt = ssh_new_packet();
3d71de0b 1925 pkt->length = 5; /* space for packet length + padding length */
dacd8872 1926 pkt->forcepad = 0;
1927 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
3d71de0b 1928 pkt->body = pkt->data + pkt->length; /* after packet type */
dacd8872 1929 return pkt;
1930}
1931
b185170a 1932/*
2e85c969 1933 * Construct an SSH-2 final-form packet: compress it, encrypt it,
b185170a 1934 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1935 * pkt->data. Total length is returned.
b185170a 1936 */
ff3187f6 1937static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1938{
7cca0d81 1939 int cipherblk, maclen, padding, i;
7cca0d81 1940
a8327734 1941 if (ssh->logctx)
ff3187f6 1942 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
acab36bc 1943 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
dacd8872 1944 pkt->body, pkt->length - (pkt->body - pkt->data),
0d13bfcd 1945 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
ff3187f6 1946 sfree(pkt->blanks); pkt->blanks = NULL;
1947 pkt->nblanks = 0;
00db133f 1948
7cca0d81 1949 /*
4ba9b64b 1950 * Compress packet payload.
1951 */
4ba9b64b 1952 {
1953 unsigned char *newpayload;
1954 int newlen;
51470298 1955 if (ssh->cscomp &&
ff3187f6 1956 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1957 pkt->length - 5,
51470298 1958 &newpayload, &newlen)) {
ff3187f6 1959 pkt->length = 5;
1960 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1961 sfree(newpayload);
4ba9b64b 1962 }
1963 }
1964
1965 /*
7cca0d81 1966 * Add padding. At least four bytes, and must also bring total
1967 * length (minus MAC) up to a multiple of the block size.
95d2d262 1968 * If pkt->forcepad is set, make sure the packet is at least that size
1969 * after padding.
7cca0d81 1970 */
51470298 1971 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1972 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1973 padding = 4;
95d2d262 1974 if (pkt->length + padding < pkt->forcepad)
1975 padding = pkt->forcepad - pkt->length;
32874aea 1976 padding +=
ff3187f6 1977 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
95d2d262 1978 assert(padding <= 255);
51470298 1979 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1980 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1981 pkt->data[4] = padding;
7cca0d81 1982 for (i = 0; i < padding; i++)
ff3187f6 1983 pkt->data[pkt->length + i] = random_byte();
1984 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1985 if (ssh->csmac)
ff3187f6 1986 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1987 pkt->length + padding,
51470298 1988 ssh->v2_outgoing_sequence);
1989 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1990
1991 if (ssh->cscipher)
371e569c 1992 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1993 pkt->data, pkt->length + padding);
51470298 1994
9442dd57 1995 pkt->encrypted_len = pkt->length + padding;
1996
ff3187f6 1997 /* Ready-to-send packet starts at pkt->data. We return length. */
1998 return pkt->length + padding + maclen;
b185170a 1999}
2000
2001/*
590f6a5f 2002 * Routines called from the main SSH code to send packets. There
2003 * are quite a few of these, because we have two separate
2004 * mechanisms for delaying the sending of packets:
2005 *
2006 * - In order to send an IGNORE message and a password message in
2007 * a single fixed-length blob, we require the ability to
2008 * concatenate the encrypted forms of those two packets _into_ a
2009 * single blob and then pass it to our <network.h> transport
2010 * layer in one go. Hence, there's a deferment mechanism which
2011 * works after packet encryption.
2012 *
2013 * - In order to avoid sending any connection-layer messages
2014 * during repeat key exchange, we have to queue up any such
2015 * outgoing messages _before_ they are encrypted (and in
2016 * particular before they're allocated sequence numbers), and
2017 * then send them once we've finished.
2018 *
2019 * I call these mechanisms `defer' and `queue' respectively, so as
2020 * to distinguish them reasonably easily.
2021 *
2022 * The functions send_noqueue() and defer_noqueue() free the packet
2023 * structure they are passed. Every outgoing packet goes through
2024 * precisely one of these functions in its life; packets passed to
2025 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2026 * these or get queued, and then when the queue is later emptied
2027 * the packets are all passed to defer_noqueue().
97ab28d7 2028 *
2029 * When using a CBC-mode cipher, it's necessary to ensure that an
2030 * attacker can't provide data to be encrypted using an IV that they
2031 * know. We ensure this by prefixing each packet that might contain
2032 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2033 * mechanism, so in this case send_noqueue() ends up redirecting to
2034 * defer_noqueue(). If you don't like this inefficiency, don't use
2035 * CBC.
b185170a 2036 */
590f6a5f 2037
97ab28d7 2038static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2039static void ssh_pkt_defersend(Ssh);
2040
590f6a5f 2041/*
2e85c969 2042 * Send an SSH-2 packet immediately, without queuing or deferring.
590f6a5f 2043 */
2044static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 2045{
5471d09a 2046 int len;
2047 int backlog;
97ab28d7 2048 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2049 /* We need to send two packets, so use the deferral mechanism. */
2050 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2051 ssh_pkt_defersend(ssh);
2052 return;
2053 }
ff3187f6 2054 len = ssh2_pkt_construct(ssh, pkt);
bf8a49a1 2055 backlog = s_write(ssh, pkt->data, len);
5471d09a 2056 if (backlog > SSH_MAX_BACKLOG)
51470298 2057 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2058
2059 ssh->outgoing_data_size += pkt->encrypted_len;
2060 if (!ssh->kex_in_progress &&
d57f70af 2061 ssh->max_data_size != 0 &&
2062 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2063 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2064
ff3187f6 2065 ssh_free_packet(pkt);
b185170a 2066}
2067
2068/*
2e85c969 2069 * Defer an SSH-2 packet.
b185170a 2070 */
97ab28d7 2071static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
32874aea 2072{
97ab28d7 2073 int len;
2074 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
cf6ddb95 2075 ssh->deferred_len == 0 && !noignore &&
2076 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
97ab28d7 2077 /*
2078 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2079 * get encrypted with a known IV.
2080 */
2081 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
27311cc7 2082 ssh2_pkt_addstring_start(ipkt);
97ab28d7 2083 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2084 }
2085 len = ssh2_pkt_construct(ssh, pkt);
51470298 2086 if (ssh->deferred_len + len > ssh->deferred_size) {
2087 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 2088 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2089 ssh->deferred_size,
2090 unsigned char);
b185170a 2091 }
ff3187f6 2092 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 2093 ssh->deferred_len += len;
9442dd57 2094 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 2095 ssh_free_packet(pkt);
b185170a 2096}
2097
2098/*
2e85c969 2099 * Queue an SSH-2 packet.
590f6a5f 2100 */
2101static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2102{
2103 assert(ssh->queueing);
2104
2105 if (ssh->queuelen >= ssh->queuesize) {
2106 ssh->queuesize = ssh->queuelen + 32;
2107 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2108 }
2109
2110 ssh->queue[ssh->queuelen++] = pkt;
2111}
2112
2113/*
2114 * Either queue or send a packet, depending on whether queueing is
2115 * set.
2116 */
2117static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2118{
2119 if (ssh->queueing)
2120 ssh2_pkt_queue(ssh, pkt);
2121 else
2122 ssh2_pkt_send_noqueue(ssh, pkt);
2123}
2124
2125/*
2126 * Either queue or defer a packet, depending on whether queueing is
2127 * set.
2128 */
2129static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2130{
2131 if (ssh->queueing)
2132 ssh2_pkt_queue(ssh, pkt);
2133 else
97ab28d7 2134 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
590f6a5f 2135}
2136
2137/*
b185170a 2138 * Send the whole deferred data block constructed by
2e85c969 2139 * ssh2_pkt_defer() or SSH-1's defer_packet().
590f6a5f 2140 *
2141 * The expected use of the defer mechanism is that you call
2142 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2143 * not currently queueing, this simply sets up deferred_send_data
2144 * and then sends it. If we _are_ currently queueing, the calls to
2145 * ssh2_pkt_defer() put the deferred packets on to the queue
2146 * instead, and therefore ssh_pkt_defersend() has no deferred data
2147 * to send. Hence, there's no need to make it conditional on
2148 * ssh->queueing.
b185170a 2149 */
51470298 2150static void ssh_pkt_defersend(Ssh ssh)
32874aea 2151{
5471d09a 2152 int backlog;
bf8a49a1 2153 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
51470298 2154 ssh->deferred_len = ssh->deferred_size = 0;
2155 sfree(ssh->deferred_send_data);
2156 ssh->deferred_send_data = NULL;
5471d09a 2157 if (backlog > SSH_MAX_BACKLOG)
51470298 2158 ssh_throttle_all(ssh, 1, backlog);
9442dd57 2159
2160 ssh->outgoing_data_size += ssh->deferred_data_size;
2161 if (!ssh->kex_in_progress &&
d57f70af 2162 ssh->max_data_size != 0 &&
2163 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 2164 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 2165 ssh->deferred_data_size = 0;
7cca0d81 2166}
2167
590f6a5f 2168/*
18524056 2169 * Send a packet whose length needs to be disguised (typically
2170 * passwords or keyboard-interactive responses).
2171 */
2172static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2173 int padsize)
2174{
2175#if 0
2176 if (0) {
2177 /*
2178 * The simplest way to do this is to adjust the
2179 * variable-length padding field in the outgoing packet.
2180 *
2181 * Currently compiled out, because some Cisco SSH servers
2182 * don't like excessively padded packets (bah, why's it
2183 * always Cisco?)
2184 */
2185 pkt->forcepad = padsize;
2186 ssh2_pkt_send(ssh, pkt);
2187 } else
2188#endif
2189 {
2190 /*
2191 * If we can't do that, however, an alternative approach is
2192 * to use the pkt_defer mechanism to bundle the packet
2193 * tightly together with an SSH_MSG_IGNORE such that their
2194 * combined length is a constant. So first we construct the
2195 * final form of this packet and defer its sending.
2196 */
2197 ssh2_pkt_defer(ssh, pkt);
2198
2199 /*
2200 * Now construct an SSH_MSG_IGNORE which includes a string
2201 * that's an exact multiple of the cipher block size. (If
2202 * the cipher is NULL so that the block size is
2203 * unavailable, we don't do this trick at all, because we
2204 * gain nothing by it.)
2205 */
cf6ddb95 2206 if (ssh->cscipher &&
2207 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
18524056 2208 int stringlen, i;
2209
2210 stringlen = (256 - ssh->deferred_len);
2211 stringlen += ssh->cscipher->blksize - 1;
2212 stringlen -= (stringlen % ssh->cscipher->blksize);
2213 if (ssh->cscomp) {
2214 /*
2215 * Temporarily disable actual compression, so we
2216 * can guarantee to get this string exactly the
2217 * length we want it. The compression-disabling
2218 * routine should return an integer indicating how
2219 * many bytes we should adjust our string length
2220 * by.
2221 */
2222 stringlen -=
2223 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2224 }
2225 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2226 ssh2_pkt_addstring_start(pkt);
2227 for (i = 0; i < stringlen; i++) {
2228 char c = (char) random_byte();
2229 ssh2_pkt_addstring_data(pkt, &c, 1);
2230 }
2231 ssh2_pkt_defer(ssh, pkt);
2232 }
2233 ssh_pkt_defersend(ssh);
2234 }
2235}
2236
2237/*
2e85c969 2238 * Send all queued SSH-2 packets. We send them by means of
590f6a5f 2239 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2240 * packets that needed to be lumped together.
2241 */
2242static void ssh2_pkt_queuesend(Ssh ssh)
2243{
2244 int i;
2245
2246 assert(!ssh->queueing);
2247
2248 for (i = 0; i < ssh->queuelen; i++)
97ab28d7 2249 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
590f6a5f 2250 ssh->queuelen = 0;
2251
2252 ssh_pkt_defersend(ssh);
2253}
2254
7cca0d81 2255#if 0
32874aea 2256void bndebug(char *string, Bignum b)
2257{
7cca0d81 2258 unsigned char *p;
2259 int i, len;
2260 p = ssh2_mpint_fmt(b, &len);
2261 debug(("%s", string));
2262 for (i = 0; i < len; i++)
32874aea 2263 debug((" %02x", p[i]));
765c4200 2264 debug(("\n"));
dcbde236 2265 sfree(p);
7cca0d81 2266}
2267#endif
2268
b672f405 2269static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
32874aea 2270{
7cca0d81 2271 unsigned char *p;
2272 int len;
2273 p = ssh2_mpint_fmt(b, &len);
b672f405 2274 hash_string(h, s, p, len);
dcbde236 2275 sfree(p);
7cca0d81 2276}
2277
2278/*
2e85c969 2279 * Packet decode functions for both SSH-1 and SSH-2.
7cca0d81 2280 */
ff3187f6 2281static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 2282{
7cca0d81 2283 unsigned long value;
ff3187f6 2284 if (pkt->length - pkt->savedpos < 4)
32874aea 2285 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2286 value = GET_32BIT(pkt->body + pkt->savedpos);
2287 pkt->savedpos += 4;
7cca0d81 2288 return value;
2289}
ff3187f6 2290static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 2291{
65a22376 2292 unsigned long value;
ff3187f6 2293 if (pkt->length - pkt->savedpos < 1)
32874aea 2294 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2295 value = pkt->body[pkt->savedpos] != 0;
2296 pkt->savedpos++;
65a22376 2297 return value;
2298}
ff3187f6 2299static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 2300{
57356d63 2301 int len;
7cca0d81 2302 *p = NULL;
45068b27 2303 *length = 0;
ff3187f6 2304 if (pkt->length - pkt->savedpos < 4)
32874aea 2305 return;
ff3187f6 2306 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 2307 if (len < 0)
2308 return;
2309 *length = len;
ff3187f6 2310 pkt->savedpos += 4;
2311 if (pkt->length - pkt->savedpos < *length)
32874aea 2312 return;
ff3187f6 2313 *p = (char *)(pkt->body + pkt->savedpos);
2314 pkt->savedpos += *length;
7cca0d81 2315}
ff3187f6 2316static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 2317{
ff3187f6 2318 if (pkt->length - pkt->savedpos < length)
0016d70b 2319 return NULL;
ff3187f6 2320 pkt->savedpos += length;
2321 return pkt->body + (pkt->savedpos - length);
0016d70b 2322}
ff3187f6 2323static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 2324 unsigned char **keystr)
2325{
2326 int j;
2327
ff3187f6 2328 j = makekey(pkt->body + pkt->savedpos,
2329 pkt->length - pkt->savedpos,
0016d70b 2330 key, keystr, 0);
2331
2332 if (j < 0)
2333 return FALSE;
2334
ff3187f6 2335 pkt->savedpos += j;
2336 assert(pkt->savedpos < pkt->length);
0016d70b 2337
2338 return TRUE;
2339}
ff3187f6 2340static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 2341{
2342 int j;
2343 Bignum b;
2344
ff3187f6 2345 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2346 pkt->length - pkt->savedpos, &b);
0016d70b 2347
2348 if (j < 0)
2349 return NULL;
2350
ff3187f6 2351 pkt->savedpos += j;
0016d70b 2352 return b;
2353}
ff3187f6 2354static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 2355{
7cca0d81 2356 char *p;
3709bfe9 2357 int length;
7cca0d81 2358 Bignum b;
2359
ff3187f6 2360 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 2361 if (!p)
32874aea 2362 return NULL;
ff3187f6 2363 if (p[0] & 0x80)
32874aea 2364 return NULL;
d8baa528 2365 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 2366 return b;
2367}
2368
7d503c31 2369/*
2e85c969 2370 * Helper function to add an SSH-2 signature blob to a packet.
1dd353b5 2371 * Expects to be shown the public key blob as well as the signature
2372 * blob. Normally works just like ssh2_pkt_addstring, but will
2373 * fiddle with the signature packet if necessary for
2374 * BUG_SSH2_RSA_PADDING.
2375 */
ff3187f6 2376static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2377 void *pkblob_v, int pkblob_len,
1dd353b5 2378 void *sigblob_v, int sigblob_len)
2379{
2380 unsigned char *pkblob = (unsigned char *)pkblob_v;
2381 unsigned char *sigblob = (unsigned char *)sigblob_v;
2382
2383 /* dmemdump(pkblob, pkblob_len); */
2384 /* dmemdump(sigblob, sigblob_len); */
2385
2386 /*
2387 * See if this is in fact an ssh-rsa signature and a buggy
2388 * server; otherwise we can just do this the easy way.
2389 */
51470298 2390 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 2391 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2392 int pos, len, siglen;
2393
2394 /*
2395 * Find the byte length of the modulus.
2396 */
2397
2398 pos = 4+7; /* skip over "ssh-rsa" */
2399 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2400 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2401 pos += 4; /* find modulus itself */
2402 while (len > 0 && pkblob[pos] == 0)
2403 len--, pos++;
2404 /* debug(("modulus length is %d\n", len)); */
2405
2406 /*
2407 * Now find the signature integer.
2408 */
2409 pos = 4+7; /* skip over "ssh-rsa" */
2410 siglen = GET_32BIT(sigblob+pos);
2411 /* debug(("signature length is %d\n", siglen)); */
2412
2413 if (len != siglen) {
2414 unsigned char newlen[4];
ff3187f6 2415 ssh2_pkt_addstring_start(pkt);
2416 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2417 /* dmemdump(sigblob, pos); */
2418 pos += 4; /* point to start of actual sig */
2419 PUT_32BIT(newlen, len);
ff3187f6 2420 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2421 /* dmemdump(newlen, 4); */
2422 newlen[0] = 0;
2423 while (len-- > siglen) {
ff3187f6 2424 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2425 /* dmemdump(newlen, 1); */
2426 }
ff3187f6 2427 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2428 /* dmemdump(sigblob+pos, siglen); */
2429 return;
2430 }
2431
2432 /* Otherwise fall through and do it the easy way. */
2433 }
2434
ff3187f6 2435 ssh2_pkt_addstring_start(pkt);
2436 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2437}
2438
2439/*
7d503c31 2440 * Examine the remote side's version string and compare it against
2441 * a list of known buggy implementations.
2442 */
51470298 2443static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2444{
2445 char *imp; /* pointer to implementation part */
7d503c31 2446 imp = vstring;
2447 imp += strcspn(imp, "-");
bd358db1 2448 if (*imp) imp++;
7d503c31 2449 imp += strcspn(imp, "-");
bd358db1 2450 if (*imp) imp++;
7d503c31 2451
51470298 2452 ssh->remote_bugs = 0;
7d503c31 2453
bf982899 2454 /*
2455 * General notes on server version strings:
2456 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2457 * here -- in particular, we've heard of one that's perfectly happy
2458 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2459 * so we can't distinguish them.
2460 */
4a693cfc 2461 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2462 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2c9c6388 2463 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2464 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2465 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2466 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2467 /*
2468 * These versions don't support SSH1_MSG_IGNORE, so we have
2469 * to use a different defence against password length
2470 * sniffing.
2471 */
51470298 2472 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2e85c969 2473 logevent("We believe remote version has SSH-1 ignore bug");
7d503c31 2474 }
2475
4a693cfc 2476 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2477 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
46ac09aa 2478 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2479 /*
2480 * These versions need a plain password sent; they can't
2481 * handle having a null and a random length of data after
2482 * the password.
2483 */
51470298 2484 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2e85c969 2485 logevent("We believe remote version needs a plain SSH-1 password");
bd358db1 2486 }
2487
4a693cfc 2488 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2489 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2c9c6388 2490 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2491 /*
2492 * These versions apparently have no clue whatever about
2493 * RSA authentication and will panic and die if they see
2494 * an AUTH_RSA message.
2495 */
51470298 2496 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
19f47a7d 2497 logevent("We believe remote version can't handle SSH-1 RSA authentication");
0df73905 2498 }
2499
4a693cfc 2500 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2501 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
b9f387af 2502 !wc_match("* VShell", imp) &&
831301f6 2503 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2504 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2505 wc_match("2.1 *", imp)))) {
32874aea 2506 /*
2507 * These versions have the HMAC bug.
2508 */
51470298 2509 ssh->remote_bugs |= BUG_SSH2_HMAC;
2e85c969 2510 logevent("We believe remote version has SSH-2 HMAC bug");
7d503c31 2511 }
1dd353b5 2512
4a693cfc 2513 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2514 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
b9f387af 2515 !wc_match("* VShell", imp) &&
2856a1b9 2516 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2517 /*
2518 * These versions have the key-derivation bug (failing to
2519 * include the literal shared secret in the hashes that
2520 * generate the keys).
2521 */
51470298 2522 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2e85c969 2523 logevent("We believe remote version has SSH-2 key-derivation bug");
088bde77 2524 }
2525
4a693cfc 2526 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2527 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
831301f6 2528 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2529 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2530 /*
2e85c969 2531 * These versions have the SSH-2 RSA padding bug.
1dd353b5 2532 */
51470298 2533 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2e85c969 2534 logevent("We believe remote version has SSH-2 RSA padding bug");
1dd353b5 2535 }
8e975795 2536
4a693cfc 2537 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2538 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
dda87a28 2539 wc_match("OpenSSH_2.[0-2]*", imp))) {
2540 /*
2e85c969 2541 * These versions have the SSH-2 session-ID bug in
dda87a28 2542 * public-key authentication.
2543 */
2544 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2e85c969 2545 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
dda87a28 2546 }
f382c87d 2547
4a693cfc 2548 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2549 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
39b8712f 2550 (wc_match("DigiSSH_2.0", imp) ||
2551 wc_match("OpenSSH_2.[0-4]*", imp) ||
e12d95a5 2552 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2553 wc_match("Sun_SSH_1.0", imp) ||
f4275b53 2554 wc_match("Sun_SSH_1.0.1", imp) ||
96bd26de 2555 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2556 wc_match("WeOnlyDo-*", imp)))) {
f382c87d 2557 /*
2e85c969 2558 * These versions have the SSH-2 rekey bug.
f382c87d 2559 */
2560 ssh->remote_bugs |= BUG_SSH2_REKEY;
2e85c969 2561 logevent("We believe remote version has SSH-2 rekey bug");
f382c87d 2562 }
c9739dba 2563
4a693cfc 2564 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2565 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
5ca836f2 2566 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2567 wc_match("1.36 sshlib: GlobalScape", imp)))) {
c9739dba 2568 /*
2569 * This version ignores our makpkt and needs to be throttled.
2570 */
2571 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2572 logevent("We believe remote version ignores SSH-2 maximum packet size");
2573 }
cf6ddb95 2574
4a693cfc 2575 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
cf6ddb95 2576 /*
2577 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2578 * none detected automatically.
2579 */
2580 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2581 logevent("We believe remote version has SSH-2 ignore bug");
2582 }
7d503c31 2583}
2584
d38d6a1f 2585/*
2586 * The `software version' part of an SSH version string is required
2587 * to contain no spaces or minus signs.
2588 */
2589static void ssh_fix_verstring(char *str)
2590{
2591 /* Eat "SSH-<protoversion>-". */
2592 assert(*str == 'S'); str++;
2593 assert(*str == 'S'); str++;
2594 assert(*str == 'H'); str++;
2595 assert(*str == '-'); str++;
2596 while (*str && *str != '-') str++;
2597 assert(*str == '-'); str++;
2598
2599 /* Convert minus signs and spaces in the remaining string into
2600 * underscores. */
2601 while (*str) {
2602 if (*str == '-' || *str == ' ')
2603 *str = '_';
2604 str++;
2605 }
2606}
2607
1fcd0d98 2608/*
2609 * Send an appropriate SSH version string.
2610 */
2611static void ssh_send_verstring(Ssh ssh, char *svers)
2612{
2613 char *verstring;
2614
2615 if (ssh->version == 2) {
2616 /*
2617 * Construct a v2 version string.
2618 */
2619 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2620 } else {
2621 /*
2622 * Construct a v1 version string.
2623 */
2624 verstring = dupprintf("SSH-%s-%s\012",
2625 (ssh_versioncmp(svers, "1.5") <= 0 ?
2626 svers : "1.5"),
2627 sshver);
2628 }
2629
2630 ssh_fix_verstring(verstring);
2631
2632 if (ssh->version == 2) {
2633 size_t len;
2634 /*
2635 * Record our version string.
2636 */
2637 len = strcspn(verstring, "\015\012");
2638 ssh->v_c = snewn(len + 1, char);
2639 memcpy(ssh->v_c, verstring, len);
2640 ssh->v_c[len] = 0;
2641 }
2642
2643 logeventf(ssh, "We claim version: %.*s",
2644 strcspn(verstring, "\015\012"), verstring);
2645 s_write(ssh, verstring, strlen(verstring));
2646 sfree(verstring);
2647}
2648
51470298 2649static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2650{
51470298 2651 struct do_ssh_init_state {
2652 int vslen;
2653 char version[10];
2654 char *vstring;
2655 int vstrsize;
2656 int i;
2657 int proto1, proto2;
2658 };
2659 crState(do_ssh_init_state);
374330e2 2660
51470298 2661 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2662
8c1835c0 2663 /* Search for a line beginning with the string "SSH-" in the input. */
2664 for (;;) {
2665 if (c != 'S') goto no;
2666 crReturn(1);
2667 if (c != 'S') goto no;
2668 crReturn(1);
2669 if (c != 'H') goto no;
2670 crReturn(1);
2671 if (c != '-') goto no;
2672 break;
2673 no:
2674 while (c != '\012')
2675 crReturn(1);
2676 crReturn(1);
374330e2 2677 }
8df7a775 2678
51470298 2679 s->vstrsize = 16;
3d88e64d 2680 s->vstring = snewn(s->vstrsize, char);
51470298 2681 strcpy(s->vstring, "SSH-");
2682 s->vslen = 4;
2683 s->i = 0;
374330e2 2684 while (1) {
8df7a775 2685 crReturn(1); /* get another char */
51470298 2686 if (s->vslen >= s->vstrsize - 1) {
2687 s->vstrsize += 16;
3d88e64d 2688 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2689 }
51470298 2690 s->vstring[s->vslen++] = c;
2691 if (s->i >= 0) {
374330e2 2692 if (c == '-') {
51470298 2693 s->version[s->i] = '\0';
2694 s->i = -1;
2695 } else if (s->i < sizeof(s->version) - 1)
2696 s->version[s->i++] = c;
c4ffc4d0 2697 } else if (c == '\012')
374330e2 2698 break;
2699 }
2700
51470298 2701 ssh->agentfwd_enabled = FALSE;
2702 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2703
51470298 2704 s->vstring[s->vslen] = 0;
a7d4653a 2705 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
fb983202 2706 logeventf(ssh, "Server version: %s", s->vstring);
51470298 2707 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2708
adf799dd 2709 /*
38d228a2 2710 * Decide which SSH protocol version to support.
adf799dd 2711 */
38d228a2 2712
2713 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2714 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2715 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2716 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2717
4a693cfc 2718 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
6b5cf8b4 2719 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2720 crStop(0);
38d228a2 2721 }
4a693cfc 2722 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
6b5cf8b4 2723 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2724 crStop(0);
38d228a2 2725 }
2726
4a693cfc 2727 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
1fcd0d98 2728 ssh->version = 2;
2729 else
2730 ssh->version = 1;
d38d6a1f 2731
2732 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2733
1fcd0d98 2734 /* Send the version string, if we haven't already */
4a693cfc 2735 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
1fcd0d98 2736 ssh_send_verstring(ssh, s->version);
2737
2738 if (ssh->version == 2) {
2739 size_t len;
2740 /*
2741 * Record their version string.
2742 */
2743 len = strcspn(s->vstring, "\015\012");
2744 ssh->v_s = snewn(len + 1, char);
2745 memcpy(ssh->v_s, s->vstring, len);
2746 ssh->v_s[len] = 0;
2747
2748 /*
2749 * Initialise SSH-2 protocol.
2750 */
2751 ssh->protocol = ssh2_protocol;
2752 ssh2_protocol_setup(ssh);
2753 ssh->s_rdpkt = ssh2_rdpkt;
2754 } else {
2755 /*
2756 * Initialise SSH-1 protocol.
2757 */
2758 ssh->protocol = ssh1_protocol;
2759 ssh1_protocol_setup(ssh);
2760 ssh->s_rdpkt = ssh1_rdpkt;
2761 }
2762 if (ssh->version == 2)
2763 do_ssh2_transport(ssh, NULL, -1, NULL);
2764
125105d1 2765 update_specials_menu(ssh->frontend);
51470298 2766 ssh->state = SSH_STATE_BEFORE_SIZE;
4a693cfc 2767 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
8df7a775 2768
51470298 2769 sfree(s->vstring);
50526e47 2770
8df7a775 2771 crFinish(0);
2772}
2773
3d9449a1 2774static void ssh_process_incoming_data(Ssh ssh,
2775 unsigned char **data, int *datalen)
2776{
bf8a49a1 2777 struct Packet *pktin;
2778
2779 pktin = ssh->s_rdpkt(ssh, data, datalen);
3d9449a1 2780 if (pktin) {
2781 ssh->protocol(ssh, NULL, 0, pktin);
2782 ssh_free_packet(pktin);
2783 }
2784}
2785
2786static void ssh_queue_incoming_data(Ssh ssh,
2787 unsigned char **data, int *datalen)
2788{
2789 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2790 *data += *datalen;
2791 *datalen = 0;
2792}
2793
2794static void ssh_process_queued_incoming_data(Ssh ssh)
2795{
2796 void *vdata;
2797 unsigned char *data;
2798 int len, origlen;
2799
2800 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2801 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2802 data = vdata;
2803 origlen = len;
2804
2805 while (!ssh->frozen && len > 0)
2806 ssh_process_incoming_data(ssh, &data, &len);
2807
2808 if (origlen > len)
2809 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2810 }
2811}
2812
2813static void ssh_set_frozen(Ssh ssh, int frozen)
2814{
a5a6f839 2815 if (ssh->s)
2816 sk_set_frozen(ssh->s, frozen);
3d9449a1 2817 ssh->frozen = frozen;
2818}
2819
51470298 2820static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2821{
bf8a49a1 2822 /* Log raw data, if we're in that mode. */
ff05dfef 2823 if (ssh->logctx)
2824 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
0d13bfcd 2825 0, NULL, NULL);
bf8a49a1 2826
51470298 2827 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2828
2829 /*
2830 * To begin with, feed the characters one by one to the
2831 * protocol initialisation / selection function do_ssh_init().
2832 * When that returns 0, we're done with the initial greeting
2833 * exchange and can move on to packet discipline.
2834 */
2835 while (1) {
51470298 2836 int ret; /* need not be kept across crReturn */
8df7a775 2837 if (datalen == 0)
2838 crReturnV; /* more data please */
51470298 2839 ret = do_ssh_init(ssh, *data);
32874aea 2840 data++;
2841 datalen--;
8df7a775 2842 if (ret == 0)
2843 break;
2844 }
2845
2846 /*
2847 * We emerge from that loop when the initial negotiation is
2848 * over and we have selected an s_rdpkt function. Now pass
2849 * everything to s_rdpkt, and then pass the resulting packets
2850 * to the proper protocol handler.
2851 */
3d9449a1 2852
8df7a775 2853 while (1) {
e375106c 2854 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2855 if (ssh->frozen) {
3d9449a1 2856 ssh_queue_incoming_data(ssh, &data, &datalen);
e375106c 2857 /* This uses up all data and cannot cause anything interesting
2858 * to happen; indeed, for anything to happen at all, we must
2859 * return, so break out. */
2860 break;
2861 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2862 /* This uses up some or all data, and may freeze the
2863 * session. */
2864 ssh_process_queued_incoming_data(ssh);
2865 } else {
2866 /* This uses up some or all data, and may freeze the
2867 * session. */
2868 ssh_process_incoming_data(ssh, &data, &datalen);
2869 }
2870 /* FIXME this is probably EBW. */
ff3187f6 2871 if (ssh->state == SSH_STATE_CLOSED)
2872 return;
8df7a775 2873 }
e375106c 2874 /* We're out of data. Go and get some more. */
8df7a775 2875 crReturnV;
2876 }
2877 crFinishV;
2878}
2879
ac934965 2880static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2881{
80ffa58b 2882 int ret = 0;
36f94d1f 2883 struct ssh_channel *c;
2884
51470298 2885 ssh->state = SSH_STATE_CLOSED;
ecbb0000 2886 expire_timer_context(ssh);
51470298 2887 if (ssh->s) {
2888 sk_close(ssh->s);
2889 ssh->s = NULL;
ac934965 2890 if (notify_exit)
2891 notify_remote_exit(ssh->frontend);
2892 else
2893 ret = 1;
f3ab576e 2894 }
36f94d1f 2895 /*
80ffa58b 2896 * Now we must shut down any port- and X-forwarded channels going
36f94d1f 2897 * through this connection.
2898 */
74a98066 2899 if (ssh->channels) {
80ffa58b 2900 while (NULL != (c = index234(ssh->channels, 0))) {
74a98066 2901 switch (c->type) {
2902 case CHAN_X11:
2903 x11_close(c->u.x11.s);
2904 break;
2905 case CHAN_SOCKDATA:
409eca86 2906 case CHAN_SOCKDATA_DORMANT:
74a98066 2907 pfd_close(c->u.pfd.s);
2908 break;
2909 }
80ffa58b 2910 del234(ssh->channels, c); /* moving next one to index 0 */
74a98066 2911 if (ssh->version == 2)
2912 bufchain_clear(&c->v.v2.outbuffer);
2913 sfree(c);
36f94d1f 2914 }
36f94d1f 2915 }
f8c9f9df 2916 /*
2917 * Go through port-forwardings, and close any associated
2918 * listening sockets.
2919 */
2920 if (ssh->portfwds) {
2921 struct ssh_portfwd *pf;
2922 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2923 /* Dispose of any listening socket. */
2924 if (pf->local)
2925 pfd_terminate(pf->local);
2926 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2927 free_portfwd(pf);
2928 }
b72bdf11 2929 freetree234(ssh->portfwds);
2930 ssh->portfwds = NULL;
f8c9f9df 2931 }
ac934965 2932
2933 return ret;
36f94d1f 2934}
2935
7555d6a5 2936static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2937 const char *error_msg, int error_code)
2938{
2939 Ssh ssh = (Ssh) plug;
2940 char addrbuf[256], *msg;
2941
2942 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2943
2944 if (type == 0)
2945 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2946 else
2947 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2948
2949 logevent(msg);
fb983202 2950 sfree(msg);
7555d6a5 2951}
2952
cbe2d68f 2953static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2954 int calling_back)
2955{
2956 Ssh ssh = (Ssh) plug;
ac934965 2957 int need_notify = ssh_do_close(ssh, FALSE);
2958
9e296bfa 2959 if (!error_msg) {
2960 if (!ssh->close_expected)
2961 error_msg = "Server unexpectedly closed network connection";
2962 else
2963 error_msg = "Server closed network connection";
ac934965 2964 }
2965
d051d1b4 2966 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2967 ssh->exitcode = 0;
2968
2425184b 2969 if (need_notify)
2970 notify_remote_exit(ssh->frontend);
2971
9e296bfa 2972 if (error_msg)
247308b5 2973 logevent(error_msg);
9e296bfa 2974 if (!ssh->close_expected || !ssh->clean_exit)
971bcc0a 2975 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2976 return 0;
2977}
2978
32874aea 2979static int ssh_receive(Plug plug, int urgent, char *data, int len)
2980{
51470298 2981 Ssh ssh = (Ssh) plug;
d8baa528 2982 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2983 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 2984 ssh_do_close(ssh, TRUE);
32874aea 2985 return 0;
3257deae 2986 }
fef97f43 2987 return 1;
374330e2 2988}
2989
5471d09a 2990static void ssh_sent(Plug plug, int bufsize)
2991{
51470298 2992 Ssh ssh = (Ssh) plug;
5471d09a 2993 /*
2994 * If the send backlog on the SSH socket itself clears, we
2995 * should unthrottle the whole world if it was throttled.
2996 */
2997 if (bufsize < SSH_MAX_BACKLOG)
51470298 2998 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2999}
3000
fb09bf1c 3001/*
8df7a775 3002 * Connect to specified host and port.
3003 * Returns an error message, or NULL on success.
6e1ebb76 3004 * Also places the canonical host name into `realhost'. It must be
3005 * freed by the caller.
8df7a775 3006 */
cbe2d68f 3007static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 3008 char **realhost, int nodelay, int keepalive)
8df7a775 3009{
51470298 3010 static const struct plug_function_table fn_table = {
7555d6a5 3011 ssh_log,
7e78000d 3012 ssh_closing,
5471d09a 3013 ssh_receive,
3014 ssh_sent,
3015 NULL
51470298 3016 };
7e78000d 3017
8df7a775 3018 SockAddr addr;
cbe2d68f 3019 const char *err;
4a693cfc 3020 char *loghost;
3021 int addressfamily, sshprot;
3022
3023 loghost = conf_get_str(ssh->conf, CONF_loghost);
3024 if (*loghost) {
881da168 3025 char *colon;
8df7a775 3026
4a693cfc 3027 ssh->savedhost = dupstr(loghost);
881da168 3028 ssh->savedport = 22; /* default ssh port */
3029
3030 /*
3031 * A colon suffix on savedhost also lets us affect
3032 * savedport.
3033 *
3034 * (FIXME: do something about IPv6 address literals here.)
3035 */
3036 colon = strrchr(ssh->savedhost, ':');
3037 if (colon) {
3038 *colon++ = '\0';
3039 if (*colon)
3040 ssh->savedport = atoi(colon);
3041 }
3042 } else {
3043 ssh->savedhost = dupstr(host);
3044 if (port < 0)
3045 port = 22; /* default ssh port */
3046 ssh->savedport = port;
3047 }
8df7a775 3048
3049 /*
3050 * Try to find host.
3051 */
4a693cfc 3052 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
05581745 3053 logeventf(ssh, "Looking up host \"%s\"%s", host,
4a693cfc 3054 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3055 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3056 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
170c1e6e 3057 if ((err = sk_addr_error(addr)) != NULL) {
3058 sk_addr_free(addr);
8df7a775 3059 return err;
170c1e6e 3060 }
42af6a67 3061 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
8df7a775 3062
8df7a775 3063 /*
3064 * Open socket.
3065 */
51470298 3066 ssh->fn = &fn_table;
e8fa8f62 3067 ssh->s = new_connection(addr, *realhost, port,
4a693cfc 3068 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
70e5d0fd 3069 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 3070 ssh->s = NULL;
39934deb 3071 notify_remote_exit(ssh->frontend);
8df7a775 3072 return err;
67c4ba2e 3073 }
8df7a775 3074
ff05dfef 3075 /*
3076 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3077 * send the version string too.
3078 */
4a693cfc 3079 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3080 if (sshprot == 0)
ff05dfef 3081 ssh->version = 1;
4a693cfc 3082 if (sshprot == 3) {
ff05dfef 3083 ssh->version = 2;
3084 ssh_send_verstring(ssh, NULL);
3085 }
3086
881da168 3087 /*
3088 * loghost, if configured, overrides realhost.
3089 */
4a693cfc 3090 if (*loghost) {
881da168 3091 sfree(*realhost);
4a693cfc 3092 *realhost = dupstr(loghost);
881da168 3093 }
3094
8df7a775 3095 return NULL;
3096}
3097
3098/*
5471d09a 3099 * Throttle or unthrottle the SSH connection.
3100 */
ff68564b 3101static void ssh_throttle_conn(Ssh ssh, int adjust)
5471d09a 3102{
ff68564b 3103 int old_count = ssh->conn_throttle_count;
3104 ssh->conn_throttle_count += adjust;
3105 assert(ssh->conn_throttle_count >= 0);
3106 if (ssh->conn_throttle_count && !old_count) {
3d9449a1 3107 ssh_set_frozen(ssh, 1);
ff68564b 3108 } else if (!ssh->conn_throttle_count && old_count) {
3d9449a1 3109 ssh_set_frozen(ssh, 0);
5471d09a 3110 }
3111}
3112
3113/*
3114 * Throttle or unthrottle _all_ local data streams (for when sends
3115 * on the SSH connection itself back up).
3116 */
51470298 3117static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 3118{
3119 int i;
3120 struct ssh_channel *c;
3121
51470298 3122 if (enable == ssh->throttled_all)
5471d09a 3123 return;
51470298 3124 ssh->throttled_all = enable;
3125 ssh->overall_bufsize = bufsize;
3126 if (!ssh->channels)
5471d09a 3127 return;
51470298 3128 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 3129 switch (c->type) {
3130 case CHAN_MAINSESSION:
3131 /*
3132 * This is treated separately, outside the switch.
3133 */
3134 break;
3135 case CHAN_X11:
3136 x11_override_throttle(c->u.x11.s, enable);
3137 break;
3138 case CHAN_AGENT:
3139 /* Agent channels require no buffer management. */
3140 break;
3141 case CHAN_SOCKDATA:
36f94d1f 3142 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 3143 break;
3144 }
3145 }
3146}
3147
f11d78f2 3148static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 3149{
3150 Ssh ssh = (Ssh) sshv;
3151
3152 ssh->agent_response = reply;
3153 ssh->agent_response_len = replylen;
3154
3155 if (ssh->version == 1)
ff3187f6 3156 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 3157 else
ff3187f6 3158 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 3159}
3160
3d9449a1 3161static void ssh_dialog_callback(void *sshv, int ret)
3162{
3163 Ssh ssh = (Ssh) sshv;
3164
3165 ssh->user_response = ret;
3166
3167 if (ssh->version == 1)
3168 do_ssh1_login(ssh, NULL, -1, NULL);
3169 else
3170 do_ssh2_transport(ssh, NULL, -1, NULL);
3171
3172 /*
3173 * This may have unfrozen the SSH connection, so do a
3174 * queued-data run.
3175 */
3176 ssh_process_queued_incoming_data(ssh);
3177}
3178
f11d78f2 3179static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 3180{
3181 struct ssh_channel *c = (struct ssh_channel *)cv;
3182 Ssh ssh = c->ssh;
3183 void *sentreply = reply;
3184
3185 if (!sentreply) {
3186 /* Fake SSH_AGENT_FAILURE. */
3187 sentreply = "\0\0\0\1\5";
3188 replylen = 5;
3189 }
3190 if (ssh->version == 2) {
3191 ssh2_add_channel_data(c, sentreply, replylen);
3192 ssh2_try_send(c);
3193 } else {
3194 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3195 PKT_INT, c->remoteid,
3196 PKT_INT, replylen,
a2724fba 3197 PKTT_DATA,
839f10db 3198 PKT_DATA, sentreply, replylen,
9a10ecf4 3199 PKTT_OTHER,
839f10db 3200 PKT_END);
3201 }
3202 if (reply)
3203 sfree(reply);
3204}
3205
0405e71f 3206/*
9e296bfa 3207 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3208 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3209 * => log `wire_reason'.
3210 */
3211static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3212 int code, int clean_exit)
3213{
3214 char *error;
3215 if (!client_reason)
3216 client_reason = wire_reason;
3217 if (client_reason)
3218 error = dupprintf("Disconnected: %s", client_reason);
3219 else
3220 error = dupstr("Disconnected");
3221 if (wire_reason) {
3222 if (ssh->version == 1) {
3223 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3224 PKT_END);
3225 } else if (ssh->version == 2) {
3226 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3227 ssh2_pkt_adduint32(pktout, code);
3228 ssh2_pkt_addstring(pktout, wire_reason);
3229 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3230 ssh2_pkt_send_noqueue(ssh, pktout);
3231 }
3232 }
3233 ssh->close_expected = TRUE;
3234 ssh->clean_exit = clean_exit;
3235 ssh_closing((Plug)ssh, error, 0, 0);
3236 sfree(error);
3237}
3238
3239/*
fb09bf1c 3240 * Handle the key exchange and user authentication phases.
3241 */
ff3187f6 3242static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3243 struct Packet *pktin)
fb09bf1c 3244{
0016d70b 3245 int i, j, ret;
3246 unsigned char cookie[8], *ptr;
374330e2 3247 struct RSAKey servkey, hostkey;
3248 struct MD5Context md5c;
51470298 3249 struct do_ssh1_login_state {
3250 int len;
3251 unsigned char *rsabuf, *keystr1, *keystr2;
3252 unsigned long supported_ciphers_mask, supported_auths_mask;
3253 int tried_publickey, tried_agent;
3254 int tis_auth_refused, ccard_auth_refused;
3255 unsigned char session_id[16];
3256 int cipher_type;
51470298 3257 void *publickey_blob;
3258 int publickey_bloblen;
edd0cb8a 3259 char *publickey_comment;
3260 int publickey_encrypted;
3261 prompts_t *cur_prompt;
51470298 3262 char c;
3263 int pwpkt_type;
3264 unsigned char request[5], *response, *p;
3265 int responselen;
3266 int keyi, nkeys;
3267 int authed;
3268 struct RSAKey key;
3269 Bignum challenge;
3270 char *commentp;
3271 int commentlen;
3d9449a1 3272 int dlgret;
4a693cfc 3273 Filename *keyfile;
51470298 3274 };
3275 crState(do_ssh1_login_state);
3276
3277 crBegin(ssh->do_ssh1_login_crstate);
374330e2 3278
ff3187f6 3279 if (!pktin)
3280 crWaitUntil(pktin);
374330e2 3281
ff3187f6 3282 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 3283 bombout(("Public key packet not received"));
7ffdbc1a 3284 crStop(0);
8d5de777 3285 }
374330e2 3286
c5e9c988 3287 logevent("Received public keys");
374330e2 3288
ff3187f6 3289 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 3290 if (!ptr) {
2e85c969 3291 bombout(("SSH-1 public key packet stopped before random cookie"));
0016d70b 3292 crStop(0);
3293 }
3294 memcpy(cookie, ptr, 8);
374330e2 3295
ff3187f6 3296 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3297 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2e85c969 3298 bombout(("Failed to read SSH-1 public keys from public key packet"));
0016d70b 3299 crStop(0);
3300 }
374330e2 3301
c5e9c988 3302 /*
1c2a93c4 3303 * Log the host key fingerprint.
c5e9c988 3304 */
c5e9c988 3305 {
3306 char logmsg[80];
1c2a93c4 3307 logevent("Host key fingerprint is:");
c5e9c988 3308 strcpy(logmsg, " ");
32874aea 3309 hostkey.comment = NULL;
3310 rsa_fingerprint(logmsg + strlen(logmsg),
3311 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 3312 logevent(logmsg);
3313 }
3314
ff3187f6 3315 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3316 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3317 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
d5b2c841 3318 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3319 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
bea1ef5f 3320
51470298 3321 ssh->v1_local_protoflags =
3322 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3323 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 3324
c5e9c988 3325 MD5Init(&md5c);
51470298 3326 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3327 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 3328 MD5Update(&md5c, cookie, 8);
51470298 3329 MD5Final(s->session_id, &md5c);
374330e2 3330
32874aea 3331 for (i = 0; i < 32; i++)
51470298 3332 ssh->session_key[i] = random_byte();
374330e2 3333
0016d70b 3334 /*
3335 * Verify that the `bits' and `bytes' parameters match.
3336 */
3337 if (hostkey.bits > hostkey.bytes * 8 ||
3338 servkey.bits > servkey.bytes * 8) {
2e85c969 3339 bombout(("SSH-1 public keys were badly formatted"));
0016d70b 3340 crStop(0);
3341 }
3342
51470298 3343 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 3344
3d88e64d 3345 s->rsabuf = snewn(s->len, unsigned char);
374330e2 3346
89ee5268 3347 /*
3348 * Verify the host key.
3349 */
3350 {
32874aea 3351 /*
3352 * First format the key into a string.
3353 */
3354 int len = rsastr_len(&hostkey);
3355 char fingerprint[100];
3d88e64d 3356 char *keystr = snewn(len, char);
32874aea 3357 rsastr_fmt(keystr, &hostkey);
3358 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3d9449a1 3359
3360 ssh_set_frozen(ssh, 1);
3361 s->dlgret = verify_ssh_host_key(ssh->frontend,
3362 ssh->savedhost, ssh->savedport,
3363 "rsa", keystr, fingerprint,
3364 ssh_dialog_callback, ssh);
32874aea 3365 sfree(keystr);
3d9449a1 3366 if (s->dlgret < 0) {
3367 do {
3368 crReturn(0);
3369 if (pktin) {
3370 bombout(("Unexpected data from server while waiting"
3371 " for user host key response"));
3372 crStop(0);
3373 }
3374 } while (pktin || inlen > 0);
3375 s->dlgret = ssh->user_response;
3376 }
3377 ssh_set_frozen(ssh, 0);
3378
3379 if (s->dlgret == 0) {
9e296bfa 3380 ssh_disconnect(ssh, "User aborted at host key verification",
3381 NULL, 0, TRUE);
2b3f6c19 3382 crStop(0);
3d9449a1 3383 }
32874aea 3384 }
3385
3386 for (i = 0; i < 32; i++) {
51470298 3387 s->rsabuf[i] = ssh->session_key[i];
374330e2 3388 if (i < 16)
51470298 3389 s->rsabuf[i] ^= s->session_id[i];
374330e2 3390 }
3391
3392 if (hostkey.bytes > servkey.bytes) {
0016d70b 3393 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3394 if (ret)
3395 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 3396 } else {
0016d70b 3397 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3398 if (ret)
3399 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3400 }
3401 if (!ret) {
2e85c969 3402 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
0016d70b 3403 crStop(0);
374330e2 3404 }
3405
c5e9c988 3406 logevent("Encrypted session key");
3407
ca20bfcf 3408 {
3409 int cipher_chosen = 0, warn = 0;
3410 char *cipher_string = NULL;
51470298 3411 int i;
ca20bfcf 3412 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
4a693cfc 3413 int next_cipher = conf_get_int_int(ssh->conf,
3414 CONF_ssh_cipherlist, i);
ca20bfcf 3415 if (next_cipher == CIPHER_WARN) {
3416 /* If/when we choose a cipher, warn about it */
3417 warn = 1;
3418 } else if (next_cipher == CIPHER_AES) {
3419 /* XXX Probably don't need to mention this. */
2e85c969 3420 logevent("AES not supported in SSH-1, skipping");
ca20bfcf 3421 } else {
3422 switch (next_cipher) {
51470298 3423 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 3424 cipher_string = "3DES"; break;
51470298 3425 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 3426 cipher_string = "Blowfish"; break;
51470298 3427 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 3428 cipher_string = "single-DES"; break;
3429 }
51470298 3430 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 3431 cipher_chosen = 1;
3432 }
3433 }
3434 if (!cipher_chosen) {
51470298 3435 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2e85c969 3436 bombout(("Server violates SSH-1 protocol by not "
ca20bfcf 3437 "supporting 3DES encryption"));
3438 else
3439 /* shouldn't happen */
6b5cf8b4 3440 bombout(("No supported ciphers found"));
7ffdbc1a 3441 crStop(0);
a99a05c0 3442 }
ca20bfcf 3443
3444 /* Warn about chosen cipher if necessary. */
bb348ab1 3445 if (warn) {
3d9449a1 3446 ssh_set_frozen(ssh, 1);
3447 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3448 ssh_dialog_callback, ssh);
3449 if (s->dlgret < 0) {
3450 do {
3451 crReturn(0);
3452 if (pktin) {
3453 bombout(("Unexpected data from server while waiting"
3454 " for user response"));
3455 crStop(0);
3456 }
3457 } while (pktin || inlen > 0);
3458 s->dlgret = ssh->user_response;
3459 }
3460 ssh_set_frozen(ssh, 0);
3461 if (s->dlgret == 0) {
9e296bfa 3462 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3463 0, TRUE);
96ccde8b 3464 crStop(0);
3d9449a1 3465 }
bb348ab1 3466 }
bea1ef5f 3467 }
ca20bfcf 3468
51470298 3469 switch (s->cipher_type) {
32874aea 3470 case SSH_CIPHER_3DES:
3471 logevent("Using 3DES encryption");
3472 break;
3473 case SSH_CIPHER_DES:
3474 logevent("Using single-DES encryption");
3475 break;
3476 case SSH_CIPHER_BLOWFISH:
3477 logevent("Using Blowfish encryption");
3478 break;
c5e9c988 3479 }
bea1ef5f 3480
51470298 3481 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3482 PKT_CHAR, s->cipher_type,
32874aea 3483 PKT_DATA, cookie, 8,
51470298 3484 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3485 PKT_DATA, s->rsabuf, s->len,
3486 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3487
c5e9c988 3488 logevent("Trying to enable encryption...");
374330e2 3489
51470298 3490 sfree(s->rsabuf);
374330e2 3491
51470298 3492 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3493 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3494 &ssh_3des);
371e569c 3495 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3496 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3497 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3498
0183b242 3499 ssh->crcda_ctx = crcda_make_context();
3500 logevent("Installing CRC compensation attack detector");
3501
679539d7 3502 if (servkey.modulus) {
3503 sfree(servkey.modulus);
3504 servkey.modulus = NULL;
3505 }
3506 if (servkey.exponent) {
3507 sfree(servkey.exponent);
3508 servkey.exponent = NULL;
3509 }
3510 if (hostkey.modulus) {
3511 sfree(hostkey.modulus);
3512 hostkey.modulus = NULL;
3513 }
3514 if (hostkey.exponent) {
3515 sfree(hostkey.exponent);
3516 hostkey.exponent = NULL;
3517 }
ff3187f6 3518 crWaitUntil(pktin);
374330e2 3519
ff3187f6 3520 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3521 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3522 crStop(0);
8d5de777 3523 }
374330e2 3524
c5e9c988 3525 logevent("Successfully started encryption");
3526
edd0cb8a 3527 fflush(stdout); /* FIXME eh? */
374330e2 3528 {
4a693cfc 3529 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 3530 int ret; /* need not be kept over crReturn */
3531 s->cur_prompt = new_prompts(ssh->frontend);
3532 s->cur_prompt->to_server = TRUE;
3533 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 3534 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 3535 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3536 while (ret < 0) {
51470298 3537 ssh->send_ok = 1;
edd0cb8a 3538 crWaitUntil(!pktin);
3539 ret = get_userpass_input(s->cur_prompt, in, inlen);
3540 ssh->send_ok = 0;
3541 }
3542 if (!ret) {
3543 /*
3544 * Failed to get a username. Terminate.
3545 */
3546 free_prompts(s->cur_prompt);
3547 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3548 crStop(0);
32874aea 3549 }
4a693cfc 3550 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 3551 free_prompts(s->cur_prompt);
374330e2 3552 }
fb09bf1c 3553
4a693cfc 3554 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
c5e9c988 3555 {
4a693cfc 3556 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
c5e9c988 3557 logevent(userlog);
32874aea 3558 if (flags & FLAG_INTERACTIVE &&
3559 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
51470298 3560 c_write_str(ssh, userlog);
edd0cb8a 3561 c_write_str(ssh, "\r\n");
3c8e959b 3562 }
edd0cb8a 3563 sfree(userlog);
c5e9c988 3564 }
374330e2 3565 }
3566
ff3187f6 3567 crWaitUntil(pktin);
374330e2 3568
d5b2c841 3569 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
0df73905 3570 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3571 s->tried_publickey = s->tried_agent = 1;
0df73905 3572 } else {
51470298 3573 s->tried_publickey = s->tried_agent = 0;
0df73905 3574 }
51470298 3575 s->tis_auth_refused = s->ccard_auth_refused = 0;
edd0cb8a 3576 /*
3577 * Load the public half of any configured keyfile for later use.
3578 */
4a693cfc 3579 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 3580 if (!filename_is_null(s->keyfile)) {
edd0cb8a 3581 int keytype;
3582 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 3583 filename_to_str(s->keyfile));
3584 keytype = key_type(s->keyfile);
edd0cb8a 3585 if (keytype == SSH_KEYTYPE_SSH1) {
3586 const char *error;
4a693cfc 3587 if (rsakey_pubblob(s->keyfile,
edd0cb8a 3588 &s->publickey_blob, &s->publickey_bloblen,
3589 &s->publickey_comment, &error)) {
4a693cfc 3590 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
edd0cb8a 3591 NULL);
3592 } else {
3593 char *msgbuf;
3594 logeventf(ssh, "Unable to load private key (%s)", error);
3595 msgbuf = dupprintf("Unable to load private key file "
3596 "\"%.150s\" (%s)\r\n",
4a693cfc 3597 filename_to_str(s->keyfile),
edd0cb8a 3598 error);
3599 c_write_str(ssh, msgbuf);
3600 sfree(msgbuf);
3601 s->publickey_blob = NULL;
3602 }
3603 } else {
3604 char *msgbuf;
3605 logeventf(ssh, "Unable to use this key file (%s)",
3606 key_type_to_str(keytype));
3607 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3608 " (%s)\r\n",
4a693cfc 3609 filename_to_str(s->keyfile),
edd0cb8a 3610 key_type_to_str(keytype));
3611 c_write_str(ssh, msgbuf);
3612 sfree(msgbuf);
51470298 3613 s->publickey_blob = NULL;
edd0cb8a 3614 }
396778f1 3615 } else
51470298 3616 s->publickey_blob = NULL;
7cca0d81 3617
ff3187f6 3618 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3619 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3620
4a693cfc 3621 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
32874aea 3622 /*
3623 * Attempt RSA authentication using Pageant.
3624 */
32874aea 3625 void *r;
3626
51470298 3627 s->authed = FALSE;
3628 s->tried_agent = 1;
32874aea 3629 logevent("Pageant is running. Requesting keys.");
3630
3631 /* Request the keys held by the agent. */
51470298 3632 PUT_32BIT(s->request, 1);
3633 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3634 if (!agent_query(s->request, 5, &r, &s->responselen,
3635 ssh_agent_callback, ssh)) {
3636 do {
3637 crReturn(0);
ff3187f6 3638 if (pktin) {
839f10db 3639 bombout(("Unexpected data from server while waiting"
3640 " for agent response"));
3641 crStop(0);
3642 }
ff3187f6 3643 } while (pktin || inlen > 0);
839f10db 3644 r = ssh->agent_response;
3645 s->responselen = ssh->agent_response_len;
3646 }
51470298 3647 s->response = (unsigned char *) r;
3648 if (s->response && s->responselen >= 5 &&
3649 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3650 s->p = s->response + 5;
3651 s->nkeys = GET_32BIT(s->p);
3652 s->p += 4;
2e85c969 3653 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
51470298 3654 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
94cd7c3a 3655 unsigned char *pkblob = s->p;
51470298 3656 s->p += 4;
0016d70b 3657 {
3658 int n, ok = FALSE;
3659 do { /* do while (0) to make breaking easy */
3660 n = ssh1_read_bignum
3661 (s->p, s->responselen-(s->p-s->response),
3662 &s->key.exponent);
3663 if (n < 0)
3664 break;
3665 s->p += n;
3666 n = ssh1_read_bignum
3667 (s->p, s->responselen-(s->p-s->response),
3668 &s->key.modulus);
3669 if (n < 0)
3670 break;
3671 s->p += n;
3672 if (s->responselen - (s->p-s->response) < 4)
3673 break;
3674 s->commentlen = GET_32BIT(s->p);
3675 s->p += 4;
3676 if (s->responselen - (s->p-s->response) <
3677 s->commentlen)
3678 break;
3679 s->commentp = (char *)s->p;
3680 s->p += s->commentlen;
3681 ok = TRUE;
3682 } while (0);
3683 if (!ok) {
3684 logevent("Pageant key list packet was truncated");
3685 break;
3686 }
3687 }
94cd7c3a 3688 if (s->publickey_blob) {
3689 if (!memcmp(pkblob, s->publickey_blob,
3690 s->publickey_bloblen)) {
3691 logeventf(ssh, "Pageant key #%d matches "
3692 "configured key file", s->keyi);
3693 s->tried_publickey = 1;
3694 } else
3695 /* Skip non-configured key */
3696 continue;
3697 }
3698 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3699 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3700 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3701 crWaitUntil(pktin);
3702 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3703 logevent("Key refused");
3704 continue;
3705 }
3706 logevent("Received RSA challenge");
ff3187f6 3707 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3708 bombout(("Server's RSA challenge was badly formatted"));
3709 crStop(0);
3710 }
3711
32874aea 3712 {
3713 char *agentreq, *q, *ret;
2d466ffd 3714 void *vret;
32874aea 3715 int len, retlen;
3716 len = 1 + 4; /* message type, bit count */
51470298 3717 len += ssh1_bignum_length(s->key.exponent);
3718 len += ssh1_bignum_length(s->key.modulus);
3719 len += ssh1_bignum_length(s->challenge);
32874aea 3720 len += 16; /* session id */
3721 len += 4; /* response format */
3d88e64d 3722 agentreq = snewn(4 + len, char);
32874aea 3723 PUT_32BIT(agentreq, len);
3724 q = agentreq + 4;
3725 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3726 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3727 q += 4;
51470298 3728 q += ssh1_write_bignum(q, s->key.exponent);
3729 q += ssh1_write_bignum(q, s->key.modulus);
3730 q += ssh1_write_bignum(q, s->challenge);
3731 memcpy(q, s->session_id, 16);
32874aea 3732 q += 16;
3733 PUT_32BIT(q, 1); /* response format */
839f10db 3734 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3735 ssh_agent_callback, ssh)) {
3736 sfree(agentreq);
3737 do {
3738 crReturn(0);
ff3187f6 3739 if (pktin) {
839f10db 3740 bombout(("Unexpected data from server"
3741 " while waiting for agent"
3742 " response"));
3743 crStop(0);
3744 }
ff3187f6 3745 } while (pktin || inlen > 0);
839f10db 3746 vret = ssh->agent_response;
3747 retlen = ssh->agent_response_len;
3748 } else
3749 sfree(agentreq);
2d466ffd 3750 ret = vret;
32874aea 3751 if (ret) {
3752 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3753 logevent("Sending Pageant's response");
51470298 3754 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3755 PKT_DATA, ret + 5, 16,
3756 PKT_END);
3757 sfree(ret);
ff3187f6 3758 crWaitUntil(pktin);
3759 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3760 logevent
3761 ("Pageant's response accepted");
3762 if (flags & FLAG_VERBOSE) {
51470298 3763 c_write_str(ssh, "Authenticated using"
3764 " RSA key \"");
3765 c_write(ssh, s->commentp,
3766 s->commentlen);
3767 c_write_str(ssh, "\" from agent\r\n");
32874aea 3768 }
51470298 3769 s->authed = TRUE;
32874aea 3770 } else
3771 logevent
3772 ("Pageant's response not accepted");
3773 } else {
3774 logevent
3775 ("Pageant failed to answer challenge");
3776 sfree(ret);
3777 }
3778 } else {
3779 logevent("No reply received from Pageant");
3780 }
3781 }
51470298 3782 freebn(s->key.exponent);
3783 freebn(s->key.modulus);
3784 freebn(s->challenge);
3785 if (s->authed)
32874aea 3786 break;
3787 }
29b1d0b3 3788 sfree(s->response);
94cd7c3a 3789 if (s->publickey_blob && !s->tried_publickey)
3790 logevent("Configured key file not in Pageant");
5ff99b8e 3791 } else {
3792 logevent("Failed to get reply from Pageant");
3793 }
51470298 3794 if (s->authed)
32874aea 3795 break;
3796 }
edd0cb8a 3797 if (s->publickey_blob && !s->tried_publickey) {
3798 /*
3799 * Try public key authentication with the specified
3800 * key file.
3801 */
3802 int got_passphrase; /* need not be kept over crReturn */
3803 if (flags & FLAG_VERBOSE)
3804 c_write_str(ssh, "Trying public key authentication.\r\n");
4a693cfc 3805 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
edd0cb8a 3806 logeventf(ssh, "Trying public key \"%s\"",
4a693cfc 3807 filename_to_str(s->keyfile));
edd0cb8a 3808 s->tried_publickey = 1;
3809 got_passphrase = FALSE;
3810 while (!got_passphrase) {
3811 /*
3812 * Get a passphrase, if necessary.
3813 */
3814 char *passphrase = NULL; /* only written after crReturn */
3815 const char *error;
3816 if (!s->publickey_encrypted) {
3817 if (flags & FLAG_VERBOSE)
3818 c_write_str(ssh, "No passphrase required.\r\n");
3819 passphrase = NULL;
3820 } else {
3821 int ret; /* need not be kept over crReturn */
3822 s->cur_prompt = new_prompts(ssh->frontend);
3823 s->cur_prompt->to_server = FALSE;
3824 s->cur_prompt->name = dupstr("SSH key passphrase");
3825 add_prompt(s->cur_prompt,
3826 dupprintf("Passphrase for key \"%.100s\": ",
b61f81bc 3827 s->publickey_comment), FALSE);
edd0cb8a 3828 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3829 while (ret < 0) {
3830 ssh->send_ok = 1;
3831 crWaitUntil(!pktin);
3832 ret = get_userpass_input(s->cur_prompt, in, inlen);
3833 ssh->send_ok = 0;
3834 }
3835 if (!ret) {
3836 /* Failed to get a passphrase. Terminate. */
3837 free_prompts(s->cur_prompt);
3838 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3839 0, TRUE);
3840 crStop(0);
3841 }
3842 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3843 free_prompts(s->cur_prompt);
3844 }
3845 /*
3846 * Try decrypting key with passphrase.
3847 */
4a693cfc 3848 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3849 ret = loadrsakey(s->keyfile, &s->key, passphrase,
edd0cb8a 3850 &error);
3851 if (passphrase) {
3852 memset(passphrase, 0, strlen(passphrase));
3853 sfree(passphrase);
3854 }
3855 if (ret == 1) {
3856 /* Correct passphrase. */
3857 got_passphrase = TRUE;
3858 } else if (ret == 0) {
3859 c_write_str(ssh, "Couldn't load private key from ");
4a693cfc 3860 c_write_str(ssh, filename_to_str(s->keyfile));
edd0cb8a 3861 c_write_str(ssh, " (");
3862 c_write_str(ssh, error);
3863 c_write_str(ssh, ").\r\n");
3864 got_passphrase = FALSE;
3865 break; /* go and try something else */
3866 } else if (ret == -1) {
3867 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
edd0cb8a 3868 got_passphrase = FALSE;
3869 /* and try again */
43536490 3870 } else {
3871 assert(0 && "unexpected return from loadrsakey()");
edc23a8a 3872 got_passphrase = FALSE; /* placate optimisers */
edd0cb8a 3873 }
3874 }
3875
3876 if (got_passphrase) {
3877
3878 /*
3879 * Send a public key attempt.
3880 */
3881 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3882 PKT_BIGNUM, s->key.modulus, PKT_END);
3883
3884 crWaitUntil(pktin);
3885 if (pktin->type == SSH1_SMSG_FAILURE) {
3886 c_write_str(ssh, "Server refused our public key.\r\n");
7b575324 3887 continue; /* go and try something else */
edd0cb8a 3888 }
3889 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3890 bombout(("Bizarre response to offer of public key"));
3891 crStop(0);
3892 }
3893
3894 {
3895 int i;
3896 unsigned char buffer[32];
3897 Bignum challenge, response;
3898
3899 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3900 bombout(("Server's RSA challenge was badly formatted"));
3901 crStop(0);
3902 }
3903 response = rsadecrypt(challenge, &s->key);
3904 freebn(s->key.private_exponent);/* burn the evidence */
3905
3906 for (i = 0; i < 32; i++) {
3907 buffer[i] = bignum_byte(response, 31 - i);
3908 }
3909
3910 MD5Init(&md5c);
3911 MD5Update(&md5c, buffer, 32);
3912 MD5Update(&md5c, s->session_id, 16);
3913 MD5Final(buffer, &md5c);
3914
3915 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3916 PKT_DATA, buffer, 16, PKT_END);
3917
3918 freebn(challenge);
3919 freebn(response);
3920 }
3921
3922 crWaitUntil(pktin);
3923 if (pktin->type == SSH1_SMSG_FAILURE) {
3924 if (flags & FLAG_VERBOSE)
3925 c_write_str(ssh, "Failed to authenticate with"
3926 " our public key.\r\n");
7b575324 3927 continue; /* go and try something else */
edd0cb8a 3928 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3929 bombout(("Bizarre response to RSA authentication response"));
3930 crStop(0);
3931 }
3932
3933 break; /* we're through! */
3934 }
3935
3936 }
3937
3938 /*
3939 * Otherwise, try various forms of password-like authentication.
3940 */
3941 s->cur_prompt = new_prompts(ssh->frontend);
32874aea 3942
4a693cfc 3943 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 3944 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3945 !s->tis_auth_refused) {
3946 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3947 logevent("Requested TIS authentication");
51470298 3948 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3949 crWaitUntil(pktin);
3950 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3951 logevent("TIS authentication declined");
3952 if (flags & FLAG_INTERACTIVE)
51470298 3953 c_write_str(ssh, "TIS authentication refused.\r\n");
3954 s->tis_auth_refused = 1;
614a20a0 3955 continue;
32874aea 3956 } else {
0016d70b 3957 char *challenge;
3958 int challengelen;
edd0cb8a 3959 char *instr_suf, *prompt;
0016d70b 3960
ff3187f6 3961 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3962 if (!challenge) {
3963 bombout(("TIS challenge packet was badly formed"));
3964 crStop(0);
3965 }
32874aea 3966 logevent("Received TIS challenge");
edd0cb8a 3967 s->cur_prompt->to_server = TRUE;
3968 s->cur_prompt->name = dupstr("SSH TIS authentication");
614a20a0 3969 /* Prompt heuristic comes from OpenSSH */
edd0cb8a 3970 if (memchr(challenge, '\n', challengelen)) {
3971 instr_suf = dupstr("");
3972 prompt = dupprintf("%.*s", challengelen, challenge);
3973 } else {
3974 instr_suf = dupprintf("%.*s", challengelen, challenge);
3975 prompt = dupstr("Response: ");
3976 }
3977 s->cur_prompt->instruction =
3978 dupprintf("Using TIS authentication.%s%s",
3979 (*instr_suf) ? "\n" : "",
3980 instr_suf);
3981 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 3982 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 3983 sfree(instr_suf);
32874aea 3984 }
3985 }
4a693cfc 3986 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
51470298 3987 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3988 !s->ccard_auth_refused) {
3989 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3990 logevent("Requested CryptoCard authentication");
51470298 3991 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3992 crWaitUntil(pktin);
3993 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3994 logevent("CryptoCard authentication declined");
51470298 3995 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3996 s->ccard_auth_refused = 1;
614a20a0 3997 continue;
32874aea 3998 } else {
0016d70b 3999 char *challenge;
4000 int challengelen;
edd0cb8a 4001 char *instr_suf, *prompt;
0016d70b 4002
ff3187f6 4003 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 4004 if (!challenge) {
4005 bombout(("CryptoCard challenge packet was badly formed"));
4006 crStop(0);
4007 }
32874aea 4008 logevent("Received CryptoCard challenge");
edd0cb8a 4009 s->cur_prompt->to_server = TRUE;
4010 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4011 s->cur_prompt->name_reqd = FALSE;
4012 /* Prompt heuristic comes from OpenSSH */
4013 if (memchr(challenge, '\n', challengelen)) {
4014 instr_suf = dupstr("");
4015 prompt = dupprintf("%.*s", challengelen, challenge);
4016 } else {
4017 instr_suf = dupprintf("%.*s", challengelen, challenge);
4018 prompt = dupstr("Response: ");
4019 }
4020 s->cur_prompt->instruction =
4021 dupprintf("Using CryptoCard authentication.%s%s",
4022 (*instr_suf) ? "\n" : "",
4023 instr_suf);
4024 s->cur_prompt->instr_reqd = TRUE;
b61f81bc 4025 add_prompt(s->cur_prompt, prompt, FALSE);
edd0cb8a 4026 sfree(instr_suf);
32874aea 4027 }
4028 }
51470298 4029 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
8f9e3231 4030 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4031 bombout(("No supported authentication methods available"));
4032 crStop(0);
4033 }
edd0cb8a 4034 s->cur_prompt->to_server = TRUE;
4035 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 4036 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4037 ssh->username, ssh->savedhost),
b61f81bc 4038 FALSE);
32874aea 4039 }
a52f067e 4040
614a20a0 4041 /*
4042 * Show password prompt, having first obtained it via a TIS
4043 * or CryptoCard exchange if we're doing TIS or CryptoCard
4044 * authentication.
4045 */
edd0cb8a 4046 {
4047 int ret; /* need not be kept over crReturn */
4048 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4049 while (ret < 0) {
4050 ssh->send_ok = 1;
4051 crWaitUntil(!pktin);
4052 ret = get_userpass_input(s->cur_prompt, in, inlen);
4053 ssh->send_ok = 0;
4054 }
4055 if (!ret) {
32874aea 4056 /*
edd0cb8a 4057 * Failed to get a password (for example
32874aea 4058 * because one was supplied on the command line
4059 * which has already failed to work). Terminate.
4060 */
edd0cb8a 4061 free_prompts(s->cur_prompt);
4062 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4063 crStop(0);
32874aea 4064 }
32874aea 4065 }
4066
edd0cb8a 4067 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 4068 /*
edd0cb8a 4069 * Defence against traffic analysis: we send a
4070 * whole bunch of packets containing strings of
4071 * different lengths. One of these strings is the
4072 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4073 * The others are all random data in
4074 * SSH1_MSG_IGNORE packets. This way a passive
4075 * listener can't tell which is the password, and
4076 * hence can't deduce the password length.
4077 *
4078 * Anybody with a password length greater than 16
4079 * bytes is going to have enough entropy in their
4080 * password that a listener won't find it _that_
4081 * much help to know how long it is. So what we'll
4082 * do is:
4083 *
4084 * - if password length < 16, we send 15 packets
4085 * containing string lengths 1 through 15
4086 *
4087 * - otherwise, we let N be the nearest multiple
4088 * of 8 below the password length, and send 8
4089 * packets containing string lengths N through
4090 * N+7. This won't obscure the order of
4091 * magnitude of the password length, but it will
4092 * introduce a bit of extra uncertainty.
4093 *
bf982899 4094 * A few servers can't deal with SSH1_MSG_IGNORE, at
4095 * least in this context. For these servers, we need
4096 * an alternative defence. We make use of the fact
4097 * that the password is interpreted as a C string:
4098 * so we can append a NUL, then some random data.
edd0cb8a 4099 *
bf982899 4100 * A few servers can deal with neither SSH1_MSG_IGNORE
4101 * here _nor_ a padded password string.
4102 * For these servers we are left with no defences
edd0cb8a 4103 * against password length sniffing.
32874aea 4104 */
bf982899 4105 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4106 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
32874aea 4107 /*
edd0cb8a 4108 * The server can deal with SSH1_MSG_IGNORE, so
4109 * we can use the primary defence.
32874aea 4110 */
edd0cb8a 4111 int bottom, top, pwlen, i;
4112 char *randomstr;
32874aea 4113
edd0cb8a 4114 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4115 if (pwlen < 16) {
4116 bottom = 0; /* zero length passwords are OK! :-) */
4117 top = 15;
4118 } else {
4119 bottom = pwlen & ~7;
4120 top = bottom + 7;
4121 }
32874aea 4122
edd0cb8a 4123 assert(pwlen >= bottom && pwlen <= top);
32874aea 4124
edd0cb8a 4125 randomstr = snewn(top + 1, char);
32874aea 4126
edd0cb8a 4127 for (i = bottom; i <= top; i++) {
4128 if (i == pwlen) {
4129 defer_packet(ssh, s->pwpkt_type,
4130 PKTT_PASSWORD, PKT_STR,
4131 s->cur_prompt->prompts[0]->result,
4132 PKTT_OTHER, PKT_END);
4133 } else {
4134 for (j = 0; j < i; j++) {
4135 do {
4136 randomstr[j] = random_byte();
4137 } while (randomstr[j] == '\0');
32874aea 4138 }
edd0cb8a 4139 randomstr[i] = '\0';
4140 defer_packet(ssh, SSH1_MSG_IGNORE,
4141 PKT_STR, randomstr, PKT_END);
32874aea 4142 }
edd0cb8a 4143 }
4144 logevent("Sending password with camouflage packets");
4145 ssh_pkt_defersend(ssh);
4146 sfree(randomstr);
4147 }
4148 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4149 /*
4150 * The server can't deal with SSH1_MSG_IGNORE
4151 * but can deal with padded passwords, so we
4152 * can use the secondary defence.
4153 */
4154 char string[64];
4155 char *ss;
4156 int len;
4157
4158 len = strlen(s->cur_prompt->prompts[0]->result);
4159 if (len < sizeof(string)) {
4160 ss = string;
4161 strcpy(string, s->cur_prompt->prompts[0]->result);
4162 len++; /* cover the zero byte */
4163 while (len < sizeof(string)) {
4164 string[len++] = (char) random_byte();
bd358db1 4165 }
bd358db1 4166 } else {
edd0cb8a 4167 ss = s->cur_prompt->prompts[0]->result;
32874aea 4168 }
edd0cb8a 4169 logevent("Sending length-padded password");
9a10ecf4 4170 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
edd0cb8a 4171 PKT_INT, len, PKT_DATA, ss, len,
4172 PKTT_OTHER, PKT_END);
4173 } else {
4174 /*
bf982899 4175 * The server is believed unable to cope with
4176 * any of our password camouflage methods.
edd0cb8a 4177 */
4178 int len;
4179 len = strlen(s->cur_prompt->prompts[0]->result);
4180 logevent("Sending unpadded password");
4181 send_packet(ssh, s->pwpkt_type,
4182 PKTT_PASSWORD, PKT_INT, len,
4183 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4184 PKTT_OTHER, PKT_END);
32874aea 4185 }
edd0cb8a 4186 } else {
4187 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4188 PKT_STR, s->cur_prompt->prompts[0]->result,
4189 PKTT_OTHER, PKT_END);
32874aea 4190 }
c5e9c988 4191 logevent("Sent password");
edd0cb8a 4192 free_prompts(s->cur_prompt);
ff3187f6 4193 crWaitUntil(pktin);
4194 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4195 if (flags & FLAG_VERBOSE)
51470298 4196 c_write_str(ssh, "Access denied\r\n");
c5e9c988 4197 logevent("Authentication refused");
ff3187f6 4198 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4199 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 4200 crStop(0);
374330e2 4201 }
4202 }
4203
edd0cb8a 4204 /* Clear up */
4205 if (s->publickey_blob) {
4206 sfree(s->publickey_blob);
4207 sfree(s->publickey_comment);
4208 }
4209
c5e9c988 4210 logevent("Authentication successful");
4211
fb09bf1c 4212 crFinish(1);
4213}
4214
bc06669b 4215static void ssh_channel_try_eof(struct ssh_channel *c)
4216{
4217 Ssh ssh = c->ssh;
4218 assert(c->pending_eof); /* precondition for calling us */
4219 if (c->halfopen)
4220 return; /* can't close: not even opened yet */
4221 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4222 return; /* can't send EOF: pending outgoing data */
4223
4224 if (ssh->version == 1) {
4225 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4226 PKT_END);
4227 c->closes |= CLOSES_SENT_EOF;
4228 } else {
4229 struct Packet *pktout;
4230 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4231 ssh2_pkt_adduint32(pktout, c->remoteid);
4232 ssh2_pkt_send(ssh, pktout);
4233 c->closes |= CLOSES_SENT_EOF;
4234 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes)) {
4235 /*
4236 * Also send MSG_CLOSE.
4237 */
4238 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4239 ssh2_pkt_adduint32(pktout, c->remoteid);
4240 ssh2_pkt_send(ssh, pktout);
4241 c->closes |= CLOSES_SENT_CLOSE;
4242 }
4243 }
4244 c->pending_eof = FALSE; /* we've sent it now */
4245}
4246
4247void sshfwd_write_eof(struct ssh_channel *c)
32874aea 4248{
51470298 4249 Ssh ssh = c->ssh;
4250
1ef619ae 4251 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4252 return;
36f94d1f 4253
bc06669b 4254 if (c->closes & CLOSES_SENT_EOF)
4255 return;
78280721 4256
bc06669b 4257 c->pending_eof = TRUE;
4258 ssh_channel_try_eof(c);
32874aea 4259}
4260
c6b41791 4261void sshfwd_unclean_close(struct ssh_channel *c)
4262{
4263 Ssh ssh = c->ssh;
4264 struct Packet *pktout;
4265
4266 if (ssh->state == SSH_STATE_CLOSED)
4267 return;
4268
4269 if (c->closes & CLOSES_SENT_CLOSE)
4270 return;
4271
4272 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4273 ssh2_pkt_adduint32(pktout, c->remoteid);
4274 ssh2_pkt_send(ssh, pktout);
4275 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
4276 switch (c->type) {
4277 case CHAN_X11:
4278 x11_close(c->u.x11.s);
4279 break;
4280 case CHAN_SOCKDATA:
4281 case CHAN_SOCKDATA_DORMANT:
4282 pfd_close(c->u.pfd.s);
4283 break;
4284 }
4285 c->type = CHAN_ZOMBIE;
4286 ssh2_channel_check_close(c);
4287}
4288
5471d09a 4289int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 4290{
51470298 4291 Ssh ssh = c->ssh;
4292
1ef619ae 4293 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4294 return 0;
36f94d1f 4295
51470298 4296 if (ssh->version == 1) {
4297 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 4298 PKT_INT, c->remoteid,
a2724fba 4299 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
9a10ecf4 4300 PKTT_OTHER, PKT_END);
5471d09a 4301 /*
2e85c969 4302 * In SSH-1 we can return 0 here - implying that forwarded
5471d09a 4303 * connections are never individually throttled - because
4304 * the only circumstance that can cause throttling will be
4305 * the whole SSH connection backing up, in which case
4306 * _everything_ will be throttled as a whole.
4307 */
4308 return 0;
783415f8 4309 } else {
32874aea 4310 ssh2_add_channel_data(c, buf, len);
5471d09a 4311 return ssh2_try_send(c);
4312 }
4313}
4314
4315void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4316{
51470298 4317 Ssh ssh = c->ssh;
ff68564b 4318 int buflimit;
51470298 4319
1ef619ae 4320 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4321 return;
36f94d1f 4322
51470298 4323 if (ssh->version == 1) {
ff68564b 4324 buflimit = SSH1_BUFFER_LIMIT;
5471d09a 4325 } else {
ff68564b 4326 buflimit = c->v.v2.locmaxwin;
4327 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4328 }
4329 if (c->throttling_conn && bufsize <= buflimit) {
4330 c->throttling_conn = 0;
4331 ssh_throttle_conn(ssh, -1);
783415f8 4332 }
9c964e85 4333}
4334
06fadff5 4335static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4336{
4337 struct queued_handler *qh = ssh->qhead;
4338
4339 assert(qh != NULL);
4340
4341 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4342
4343 if (qh->msg1 > 0) {
4344 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4345 ssh->packet_dispatch[qh->msg1] = NULL;
4346 }
4347 if (qh->msg2 > 0) {
4348 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4349 ssh->packet_dispatch[qh->msg2] = NULL;
4350 }
4351
4352 if (qh->next) {
4353 ssh->qhead = qh->next;
4354
4355 if (ssh->qhead->msg1 > 0) {
4356 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4357 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4358 }
4359 if (ssh->qhead->msg2 > 0) {
4360 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4361 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4362 }
4363 } else {
4364 ssh->qhead = ssh->qtail = NULL;
4365 ssh->packet_dispatch[pktin->type] = NULL;
4366 }
4367
4368 qh->handler(ssh, pktin, qh->ctx);
4369
4370 sfree(qh);
4371}
4372
4373static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4374 chandler_fn_t handler, void *ctx)
4375{
4376 struct queued_handler *qh;
4377
4378 qh = snew(struct queued_handler);
4379 qh->msg1 = msg1;
4380 qh->msg2 = msg2;
4381 qh->handler = handler;
4382 qh->ctx = ctx;
4383 qh->next = NULL;
4384
4385 if (ssh->qtail == NULL) {
4386 ssh->qhead = qh;
4387
4388 if (qh->msg1 > 0) {
4389 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4390 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4391 }
4392 if (qh->msg2 > 0) {
4393 assert(ssh->packet_dispatch[qh->msg2] == NULL);
4394 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4395 }
4396 } else {
4397 ssh->qtail->next = qh;
4398 }
4399 ssh->qtail = qh;
4400}
4401
4402static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4403{
4404 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4405
4406 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4407 SSH2_MSG_REQUEST_SUCCESS)) {
4408 logeventf(ssh, "Remote port forwarding from %s enabled",
4409 pf->sportdesc);
4410 } else {
4411 logeventf(ssh, "Remote port forwarding from %s refused",
4412 pf->sportdesc);
4413
4414 rpf = del234(ssh->rportfwds, pf);
4415 assert(rpf == pf);
8aea57fd 4416 pf->pfrec->remote = NULL;
fda2feb1 4417 free_rportfwd(pf);
06fadff5 4418 }
4419}
4420
4a693cfc 4421static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
06fadff5 4422{
84328ddb 4423 struct ssh_portfwd *epf;
4424 int i;
4a693cfc 4425 char *key, *val;
06fadff5 4426
fda2feb1 4427 if (!ssh->portfwds) {
4428 ssh->portfwds = newtree234(ssh_portcmp);
4429 } else {
4430 /*
4431 * Go through the existing port forwardings and tag them
84328ddb 4432 * with status==DESTROY. Any that we want to keep will be
4433 * re-enabled (status==KEEP) as we go through the
4434 * configuration and find out which bits are the same as
4435 * they were before.
fda2feb1 4436 */
4437 struct ssh_portfwd *epf;
4438 int i;
4439 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 4440 epf->status = DESTROY;
fda2feb1 4441 }
4442
4a693cfc 4443 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4444 val != NULL;
4445 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4446 char *kp, *kp2, *vp, *vp2;
84328ddb 4447 char address_family, type;
4448 int sport,dport,sserv,dserv;
4a693cfc 4449 char *sports, *dports, *saddr, *host;
4450
4451 kp = key;
84328ddb 4452
05581745 4453 address_family = 'A';
4454 type = 'L';
4a693cfc 4455 if (*kp == 'A' || *kp == '4' || *kp == '6')
4456 address_family = *kp++;
4457 if (*kp == 'L' || *kp == 'R')
4458 type = *kp++;
4459
4460 if ((kp2 = strchr(kp, ':')) != NULL) {
4461 /*
4462 * There's a colon in the middle of the source port
4463 * string, which means that the part before it is
4464 * actually a source address.
4465 */
4466 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4467 sports = kp2+1;
06fadff5 4468 } else {
4a693cfc 4469 saddr = NULL;
4470 sports = kp;
06fadff5 4471 }
4472 sport = atoi(sports);
4473 sserv = 0;
4474 if (sport == 0) {
4475 sserv = 1;
4476 sport = net_service_lookup(sports);
4477 if (!sport) {
4478 logeventf(ssh, "Service lookup failed for source"
4479 " port \"%s\"", sports);
4480 }
4481 }
4a693cfc 4482
4483 if (type == 'L' && !strcmp(val, "D")) {
4484 /* dynamic forwarding */
4485 host = NULL;
4486 dports = NULL;
4487 dport = -1;
4488 dserv = 0;
4489 type = 'D';
4490 } else {
4491 /* ordinary forwarding */
4492 vp = val;
4493 vp2 = vp + strcspn(vp, ":");
4494 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4495 if (vp2)
4496 vp2++;
4497 dports = vp2;
4498 dport = atoi(dports);
4499 dserv = 0;
4500 if (dport == 0) {
4501 dserv = 1;
4502 dport = net_service_lookup(dports);
4503 if (!dport) {
4504 logeventf(ssh, "Service lookup failed for destination"
4505 " port \"%s\"", dports);
4506 }
4507 }
4508 }
4509
06fadff5 4510 if (sport && dport) {
4511 /* Set up a description of the source port. */
fda2feb1 4512 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 4513
4514 pfrec = snew(struct ssh_portfwd);
4515 pfrec->type = type;
4a693cfc 4516 pfrec->saddr = saddr;
3fe92132 4517 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 4518 pfrec->sport = sport;
4a693cfc 4519 pfrec->daddr = host;
3fe92132 4520 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 4521 pfrec->dport = dport;
4522 pfrec->local = NULL;
4523 pfrec->remote = NULL;
05581745 4524 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4525 address_family == '6' ? ADDRTYPE_IPV6 :
4526 ADDRTYPE_UNSPEC);
fda2feb1 4527
4528 epfrec = add234(ssh->portfwds, pfrec);
4529 if (epfrec != pfrec) {
c00c1931 4530 if (epfrec->status == DESTROY) {
4531 /*
4532 * We already have a port forwarding up and running
4533 * with precisely these parameters. Hence, no need
4534 * to do anything; simply re-tag the existing one
4535 * as KEEP.
4536 */
4537 epfrec->status = KEEP;
4538 }
fda2feb1 4539 /*
c00c1931 4540 * Anything else indicates that there was a duplicate
4541 * in our input, which we'll silently ignore.
fda2feb1 4542 */
fda2feb1 4543 free_portfwd(pfrec);
84328ddb 4544 } else {
4545 pfrec->status = CREATE;
4546 }
4a693cfc 4547 } else {
4548 sfree(saddr);
4549 sfree(host);
84328ddb 4550 }
4551 }
4552
4553 /*
4554 * Now go through and destroy any port forwardings which were
4555 * not re-enabled.
4556 */
4557 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4558 if (epf->status == DESTROY) {
4559 char *message;
4560
4561 message = dupprintf("%s port forwarding from %s%s%d",
4562 epf->type == 'L' ? "local" :
4563 epf->type == 'R' ? "remote" : "dynamic",
4564 epf->saddr ? epf->saddr : "",
4565 epf->saddr ? ":" : "",
4566 epf->sport);
4567
4568 if (epf->type != 'D') {
4569 char *msg2 = dupprintf("%s to %s:%d", message,
4570 epf->daddr, epf->dport);
4571 sfree(message);
4572 message = msg2;
4573 }
4574
4575 logeventf(ssh, "Cancelling %s", message);
4576 sfree(message);
4577
8aea57fd 4578 /* epf->remote or epf->local may be NULL if setting up a
4579 * forwarding failed. */
84328ddb 4580 if (epf->remote) {
4581 struct ssh_rportfwd *rpf = epf->remote;
4582 struct Packet *pktout;
4583
4584 /*
4585 * Cancel the port forwarding at the server
4586 * end.
4587 */
4588 if (ssh->version == 1) {
4589 /*
4590 * We cannot cancel listening ports on the
2e85c969 4591 * server side in SSH-1! There's no message
84328ddb 4592 * to support it. Instead, we simply remove
4593 * the rportfwd record from the local end
4594 * so that any connections the server tries
4595 * to make on it are rejected.
4596 */
4597 } else {
4598 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4599 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4600 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4601 if (epf->saddr) {
4602 ssh2_pkt_addstring(pktout, epf->saddr);
4a693cfc 4603 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4604 /* XXX: rport_acceptall may not represent
5188540b 4605 * what was used to open the original connection,
4606 * since it's reconfigurable. */
84328ddb 4607 ssh2_pkt_addstring(pktout, "0.0.0.0");
4608 } else {
4609 ssh2_pkt_addstring(pktout, "127.0.0.1");
4610 }
4611 ssh2_pkt_adduint32(pktout, epf->sport);
4612 ssh2_pkt_send(ssh, pktout);
4613 }
4614
4615 del234(ssh->rportfwds, rpf);
4616 free_rportfwd(rpf);
4617 } else if (epf->local) {
4618 pfd_terminate(epf->local);
4619 }
4620
4621 delpos234(ssh->portfwds, i);
4622 free_portfwd(epf);
4623 i--; /* so we don't skip one in the list */
4624 }
4625
4626 /*
4627 * And finally, set up any new port forwardings (status==CREATE).
4628 */
4629 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4630 if (epf->status == CREATE) {
4631 char *sportdesc, *dportdesc;
3fe92132 4632 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 4633 epf->saddr ? epf->saddr : "",
4634 epf->saddr ? ":" : "",
3fe92132 4635 epf->sserv ? epf->sserv : "",
4636 epf->sserv ? "(" : "",
4637 epf->sport,
4638 epf->sserv ? ")" : "");
84328ddb 4639 if (epf->type == 'D') {
4640 dportdesc = NULL;
4641 } else {
3fe92132 4642 dportdesc = dupprintf("%s:%s%s%d%s",
4643 epf->daddr,
4644 epf->dserv ? epf->dserv : "",
4645 epf->dserv ? "(" : "",
4646 epf->dport,
4647 epf->dserv ? ")" : "");
84328ddb 4648 }
05581745 4649
84328ddb 4650 if (epf->type == 'L') {
4651 const char *err = pfd_addforward(epf->daddr, epf->dport,
4652 epf->saddr, epf->sport,
4a693cfc 4653 ssh, conf,
84328ddb 4654 &epf->local,
4655 epf->addressfamily);
4656
4657 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4658 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4659 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4660 sportdesc, dportdesc,
4661 err ? " failed: " : "", err ? err : "");
4662 } else if (epf->type == 'D') {
06fadff5 4663 const char *err = pfd_addforward(NULL, -1,
84328ddb 4664 epf->saddr, epf->sport,
4a693cfc 4665 ssh, conf,
84328ddb 4666 &epf->local,
4667 epf->addressfamily);
4668
4669 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4670 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4671 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4672 sportdesc,
4673 err ? " failed: " : "", err ? err : "");
06fadff5 4674 } else {
4675 struct ssh_rportfwd *pf;
4676
4677 /*
4678 * Ensure the remote port forwardings tree exists.
4679 */
4680 if (!ssh->rportfwds) {
4681 if (ssh->version == 1)
4682 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4683 else
4684 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4685 }
4686
4687 pf = snew(struct ssh_rportfwd);
84328ddb 4688 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4689 pf->dhost[lenof(pf->dhost)-1] = '\0';
4690 pf->dport = epf->dport;
4691 pf->sport = epf->sport;
06fadff5 4692 if (add234(ssh->rportfwds, pf) != pf) {
4693 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4694 epf->daddr, epf->dport);
06fadff5 4695 sfree(pf);
4696 } else {
4697 logeventf(ssh, "Requesting remote port %s"
84328ddb 4698 " forward to %s", sportdesc, dportdesc);
06fadff5 4699
4700 pf->sportdesc = sportdesc;
4701 sportdesc = NULL;
84328ddb 4702 epf->remote = pf;
4703 pf->pfrec = epf;
06fadff5 4704
4705 if (ssh->version == 1) {
4706 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4707 PKT_INT, epf->sport,
4708 PKT_STR, epf->daddr,
4709 PKT_INT, epf->dport,
06fadff5 4710 PKT_END);
4711 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4712 SSH1_SMSG_FAILURE,
4713 ssh_rportfwd_succfail, pf);
4714 } else {
4715 struct Packet *pktout;
4716 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4717 ssh2_pkt_addstring(pktout, "tcpip-forward");
4718 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4719 if (epf->saddr) {
4720 ssh2_pkt_addstring(pktout, epf->saddr);
4a693cfc 4721 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
06fadff5 4722 ssh2_pkt_addstring(pktout, "0.0.0.0");
4723 } else {
4724 ssh2_pkt_addstring(pktout, "127.0.0.1");
4725 }
84328ddb 4726 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4727 ssh2_pkt_send(ssh, pktout);
4728
4729 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4730 SSH2_MSG_REQUEST_FAILURE,
4731 ssh_rportfwd_succfail, pf);
4732 }
4733 }
4734 }
4735 sfree(sportdesc);
84328ddb 4736 sfree(dportdesc);
06fadff5 4737 }
06fadff5 4738}
4739
51df0ab5 4740static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4741{
4742 char *string;
4743 int stringlen, bufsize;
4744
4745 ssh_pkt_getstring(pktin, &string, &stringlen);
4746 if (string == NULL) {
4747 bombout(("Incoming terminal data packet was badly formed"));
4748 return;
4749 }
4750
4751 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4752 string, stringlen);
4753 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4754 ssh->v1_stdout_throttling = 1;
ff68564b 4755 ssh_throttle_conn(ssh, +1);
51df0ab5 4756 }
4757}
4758
4759static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4760{
4761 /* Remote side is trying to open a channel to talk to our
4762 * X-Server. Give them back a local channel number. */
4763 struct ssh_channel *c;
4764 int remoteid = ssh_pkt_getuint32(pktin);
4765
4766 logevent("Received X11 connect request");
4767 /* Refuse if X11 forwarding is disabled. */
4768 if (!ssh->X11_fwd_enabled) {
4769 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4770 PKT_INT, remoteid, PKT_END);
4771 logevent("Rejected X11 connect request");
4772 } else {
4773 c = snew(struct ssh_channel);
4774 c->ssh = ssh;
4775
8def70c3 4776 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4a693cfc 4777 NULL, -1, ssh->conf) != NULL) {
51df0ab5 4778 logevent("Opening X11 forward connection failed");
4779 sfree(c);
4780 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4781 PKT_INT, remoteid, PKT_END);
4782 } else {
4783 logevent
4784 ("Opening X11 forward connection succeeded");
4785 c->remoteid = remoteid;
64d6ff88 4786 c->halfopen = FALSE;
51df0ab5 4787 c->localid = alloc_channel_id(ssh);
4788 c->closes = 0;
bc06669b 4789 c->pending_eof = FALSE;
ff68564b 4790 c->throttling_conn = 0;
51df0ab5 4791 c->type = CHAN_X11; /* identify channel type */
4792 add234(ssh->channels, c);
4793 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4794 PKT_INT, c->remoteid, PKT_INT,
4795 c->localid, PKT_END);
4796 logevent("Opened X11 forward channel");
4797 }
4798 }
4799}
4800
4801static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4802{
4803 /* Remote side is trying to open a channel to talk to our
4804 * agent. Give them back a local channel number. */
4805 struct ssh_channel *c;
4806 int remoteid = ssh_pkt_getuint32(pktin);
4807
4808 /* Refuse if agent forwarding is disabled. */
4809 if (!ssh->agentfwd_enabled) {
4810 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4811 PKT_INT, remoteid, PKT_END);
4812 } else {
4813 c = snew(struct ssh_channel);
4814 c->ssh = ssh;
4815 c->remoteid = remoteid;
64d6ff88 4816 c->halfopen = FALSE;
51df0ab5 4817 c->localid = alloc_channel_id(ssh);
4818 c->closes = 0;
bc06669b 4819 c->pending_eof = FALSE;
ff68564b 4820 c->throttling_conn = 0;
51df0ab5 4821 c->type = CHAN_AGENT; /* identify channel type */
4822 c->u.a.lensofar = 0;
bc06669b 4823 c->u.a.message = NULL;
51df0ab5 4824 add234(ssh->channels, c);
4825 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4826 PKT_INT, c->remoteid, PKT_INT, c->localid,
4827 PKT_END);
4828 }
4829}
4830
4831static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4832{
4833 /* Remote side is trying to open a channel to talk to a
4834 * forwarded port. Give them back a local channel number. */
4835 struct ssh_channel *c;
05581745 4836 struct ssh_rportfwd pf, *pfp;
51df0ab5 4837 int remoteid;
4838 int hostsize, port;
fb983202 4839 char *host;
51df0ab5 4840 const char *e;
4841 c = snew(struct ssh_channel);
4842 c->ssh = ssh;
4843
4844 remoteid = ssh_pkt_getuint32(pktin);
4845 ssh_pkt_getstring(pktin, &host, &hostsize);
4846 port = ssh_pkt_getuint32(pktin);
4847
4848 if (hostsize >= lenof(pf.dhost))
4849 hostsize = lenof(pf.dhost)-1;
4850 memcpy(pf.dhost, host, hostsize);
4851 pf.dhost[hostsize] = '\0';
4852 pf.dport = port;
05581745 4853 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4854
05581745 4855 if (pfp == NULL) {
fb983202 4856 logeventf(ssh, "Rejected remote port open request for %s:%d",
4857 pf.dhost, port);
51df0ab5 4858 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4859 PKT_INT, remoteid, PKT_END);
4860 } else {
fb983202 4861 logeventf(ssh, "Received remote port open request for %s:%d",
4862 pf.dhost, port);
51df0ab5 4863 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4a693cfc 4864 c, ssh->conf, pfp->pfrec->addressfamily);
51df0ab5 4865 if (e != NULL) {
fb983202 4866 logeventf(ssh, "Port open failed: %s", e);
51df0ab5 4867 sfree(c);
4868 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4869 PKT_INT, remoteid, PKT_END);
4870 } else {
4871 c->remoteid = remoteid;
64d6ff88 4872 c->halfopen = FALSE;
51df0ab5 4873 c->localid = alloc_channel_id(ssh);
4874 c->closes = 0;
bc06669b 4875 c->pending_eof = FALSE;
ff68564b 4876 c->throttling_conn = 0;
51df0ab5 4877 c->type = CHAN_SOCKDATA; /* identify channel type */
4878 add234(ssh->channels, c);
4879 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4880 PKT_INT, c->remoteid, PKT_INT,
4881 c->localid, PKT_END);
4882 logevent("Forwarded port opened successfully");
4883 }
4884 }
4885}
4886
4887static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4888{
4889 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4890 unsigned int localid = ssh_pkt_getuint32(pktin);
4891 struct ssh_channel *c;
4892
4893 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4894 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4895 c->remoteid = localid;
64d6ff88 4896 c->halfopen = FALSE;
51df0ab5 4897 c->type = CHAN_SOCKDATA;
ff68564b 4898 c->throttling_conn = 0;
51df0ab5 4899 pfd_confirm(c->u.pfd.s);
4900 }
4901
bc06669b 4902 if (c && c->pending_eof) {
51df0ab5 4903 /*
4904 * We have a pending close on this channel,
4905 * which we decided on before the server acked
4906 * the channel open. So now we know the
4907 * remoteid, we can close it again.
4908 */
bc06669b 4909 ssh_channel_try_eof(c);
51df0ab5 4910 }
4911}
4912
4913static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4914{
4915 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4916 struct ssh_channel *c;
4917
4918 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4919 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4920 logevent("Forwarded connection refused by server");
4921 pfd_close(c->u.pfd.s);
4922 del234(ssh->channels, c);
4923 sfree(c);
4924 }
4925}
4926
4927static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4928{
4929 /* Remote side closes a channel. */
4930 unsigned i = ssh_pkt_getuint32(pktin);
4931 struct ssh_channel *c;
4932 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 4933 if (c && !c->halfopen) {
51df0ab5 4934
bc06669b 4935 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
4936 !(c->closes & CLOSES_RCVD_EOF)) {
4937 /*
4938 * Received CHANNEL_CLOSE, which we translate into
4939 * outgoing EOF.
4940 */
4941 int send_close = FALSE;
4942
4943 c->closes |= CLOSES_RCVD_EOF;
4944
4945 switch (c->type) {
4946 case CHAN_X11:
4947 if (c->u.x11.s)
4948 x11_send_eof(c->u.x11.s);
4949 else
4950 send_close = TRUE;
4951 case CHAN_SOCKDATA:
4952 if (c->u.pfd.s)
4953 x11_send_eof(c->u.pfd.s);
4954 else
4955 send_close = TRUE;
4956 case CHAN_AGENT:
4957 send_close = TRUE;
4958 }
51df0ab5 4959
bc06669b 4960 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
4961 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4962 PKT_END);
4963 c->closes |= CLOSES_SENT_EOF;
4964 }
4965 }
4966
4967 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
4968 !(c->closes & CLOSES_RCVD_CLOSE)) {
4969
4970 if (!(c->closes & CLOSES_SENT_EOF)) {
4971 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
4972 " for which we never sent CHANNEL_CLOSE\n", i));
4973 }
4974
4975 c->closes |= CLOSES_RCVD_CLOSE;
4976 }
4977
4978 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
4979 !(c->closes & CLOSES_SENT_CLOSE)) {
4980 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
4981 PKT_INT, c->remoteid, PKT_END);
4982 c->closes |= CLOSES_SENT_CLOSE;
4983 }
4984
4985 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
4986 ssh_channel_destroy(c);
51df0ab5 4987 } else {
4988 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4989 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4990 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4991 i));
4992 }
4993}
4994
4995static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4996{
4997 /* Data sent down one of our channels. */
4998 int i = ssh_pkt_getuint32(pktin);
4999 char *p;
6d44acc9 5000 int len;
51df0ab5 5001 struct ssh_channel *c;
5002
5003 ssh_pkt_getstring(pktin, &p, &len);
5004
5005 c = find234(ssh->channels, &i, ssh_channelfind);
5006 if (c) {
5007 int bufsize = 0;
5008 switch (c->type) {
5009 case CHAN_X11:
5010 bufsize = x11_send(c->u.x11.s, p, len);
5011 break;
5012 case CHAN_SOCKDATA:
5013 bufsize = pfd_send(c->u.pfd.s, p, len);
5014 break;
5015 case CHAN_AGENT:
5016 /* Data for an agent message. Buffer it. */
5017 while (len > 0) {
5018 if (c->u.a.lensofar < 4) {
62ddb51e 5019 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
51df0ab5 5020 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5021 l);
5022 p += l;
5023 len -= l;
5024 c->u.a.lensofar += l;
5025 }
5026 if (c->u.a.lensofar == 4) {
5027 c->u.a.totallen =
5028 4 + GET_32BIT(c->u.a.msglen);
5029 c->u.a.message = snewn(c->u.a.totallen,
5030 unsigned char);
5031 memcpy(c->u.a.message, c->u.a.msglen, 4);
5032 }
5033 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 5034 unsigned int l =
51df0ab5 5035 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 5036 (unsigned)len);
51df0ab5 5037 memcpy(c->u.a.message + c->u.a.lensofar, p,
5038 l);
5039 p += l;
5040 len -= l;
5041 c->u.a.lensofar += l;
5042 }
5043 if (c->u.a.lensofar == c->u.a.totallen) {
5044 void *reply;
5045 int replylen;
5046 if (agent_query(c->u.a.message,
5047 c->u.a.totallen,
5048 &reply, &replylen,
5049 ssh_agentf_callback, c))
5050 ssh_agentf_callback(c, reply, replylen);
5051 sfree(c->u.a.message);
5052 c->u.a.lensofar = 0;
5053 }
5054 }
5055 bufsize = 0; /* agent channels never back up */
5056 break;
5057 }
ff68564b 5058 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5059 c->throttling_conn = 1;
5060 ssh_throttle_conn(ssh, +1);
51df0ab5 5061 }
5062 }
5063}
5064
5065static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5066{
51df0ab5 5067 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 5068 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 5069 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5070 /*
5071 * In case `helpful' firewalls or proxies tack
5072 * extra human-readable text on the end of the
5073 * session which we might mistake for another
5074 * encrypted packet, we close the session once
5075 * we've sent EXIT_CONFIRMATION.
5076 */
9e296bfa 5077 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
51df0ab5 5078}
5079
c6ccd5c2 5080/* Helper function to deal with sending tty modes for REQUEST_PTY */
5081static void ssh1_send_ttymode(void *data, char *mode, char *val)
5082{
5083 struct Packet *pktout = (struct Packet *)data;
5084 int i = 0;
5085 unsigned int arg = 0;
5086 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5087 if (i == lenof(ssh_ttymodes)) return;
5088 switch (ssh_ttymodes[i].type) {
5089 case TTY_OP_CHAR:
5090 arg = ssh_tty_parse_specchar(val);
5091 break;
5092 case TTY_OP_BOOL:
5093 arg = ssh_tty_parse_boolean(val);
5094 break;
5095 }
5096 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5097 ssh2_pkt_addbyte(pktout, arg);
5098}
5099
5100
b09eaa88 5101static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5102 struct Packet *pktin)
32874aea 5103{
b09eaa88 5104 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 5105
51df0ab5 5106 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5107 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5108 ssh1_smsg_stdout_stderr_data;
5109
5110 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5111 ssh1_msg_channel_open_confirmation;
5112 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5113 ssh1_msg_channel_open_failure;
5114 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5115 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5116 ssh1_msg_channel_close;
5117 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5118 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5119
4a693cfc 5120 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
32874aea 5121 logevent("Requesting agent forwarding");
51470298 5122 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 5123 do {
5124 crReturnV;
ff3187f6 5125 } while (!pktin);
5126 if (pktin->type != SSH1_SMSG_SUCCESS
5127 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5128 bombout(("Protocol confusion"));
7ffdbc1a 5129 crStopV;
ff3187f6 5130 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5131 logevent("Agent forwarding refused");
5132 } else {
5133 logevent("Agent forwarding enabled");
51470298 5134 ssh->agentfwd_enabled = TRUE;
51df0ab5 5135 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 5136 }
dacbd0e8 5137 }
5138
4a693cfc 5139 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5140 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5141 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
32874aea 5142 logevent("Requesting X11 forwarding");
f68353be 5143 /*
5144 * Note that while we blank the X authentication data here, we don't
5145 * take any special action to blank the start of an X11 channel,
5146 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5147 * without having session blanking enabled is likely to leak your
5148 * cookie into the log.
5149 */
51470298 5150 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5151 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5152 PKT_STR, ssh->x11disp->remoteauthprotoname,
5153 PKTT_PASSWORD,
5154 PKT_STR, ssh->x11disp->remoteauthdatastring,
5155 PKTT_OTHER,
5156 PKT_INT, ssh->x11disp->screennum,
421d6835 5157 PKT_END);
32874aea 5158 } else {
51470298 5159 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
8def70c3 5160 PKT_STR, ssh->x11disp->remoteauthprotoname,
5161 PKTT_PASSWORD,
5162 PKT_STR, ssh->x11disp->remoteauthdatastring,
5163 PKTT_OTHER,
5164 PKT_END);
32874aea 5165 }
5166 do {
5167 crReturnV;
ff3187f6 5168 } while (!pktin);
5169 if (pktin->type != SSH1_SMSG_SUCCESS
5170 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5171 bombout(("Protocol confusion"));
7ffdbc1a 5172 crStopV;
ff3187f6 5173 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 5174 logevent("X11 forwarding refused");
5175 } else {
5176 logevent("X11 forwarding enabled");
51470298 5177 ssh->X11_fwd_enabled = TRUE;
51df0ab5 5178 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 5179 }
5180 }
5181
4a693cfc 5182 ssh_setup_portfwd(ssh, ssh->conf);
06fadff5 5183 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 5184
4a693cfc 5185 if (!conf_get_int(ssh->conf, CONF_nopty)) {
c6ccd5c2 5186 struct Packet *pkt;
a5dd8467 5187 /* Unpick the terminal-speed string. */
5188 /* XXX perhaps we should allow no speeds to be sent. */
db219738 5189 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4a693cfc 5190 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 5191 /* Send the pty request. */
c6ccd5c2 5192 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4a693cfc 5193 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
c6ccd5c2 5194 ssh_pkt_adduint32(pkt, ssh->term_height);
5195 ssh_pkt_adduint32(pkt, ssh->term_width);
5196 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5197 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4a693cfc 5198 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
c6ccd5c2 5199 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5200 ssh_pkt_adduint32(pkt, ssh->ispeed);
5201 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5202 ssh_pkt_adduint32(pkt, ssh->ospeed);
5203 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5204 s_wrpkt(ssh, pkt);
51470298 5205 ssh->state = SSH_STATE_INTERMED;
32874aea 5206 do {
5207 crReturnV;
ff3187f6 5208 } while (!pktin);
5209 if (pktin->type != SSH1_SMSG_SUCCESS
5210 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5211 bombout(("Protocol confusion"));
7ffdbc1a 5212 crStopV;
ff3187f6 5213 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5214 c_write_str(ssh, "Server refused to allocate pty\r\n");
5215 ssh->editing = ssh->echoing = 1;
4a202fc6 5216 } else {
5217 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5218 ssh->ospeed, ssh->ispeed);
5219 ssh->got_pty = TRUE;
5220 }
0965bee0 5221 } else {
51470298 5222 ssh->editing = ssh->echoing = 1;
374330e2 5223 }
5224
4a693cfc 5225 if (conf_get_int(ssh->conf, CONF_compression)) {
51470298 5226 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 5227 do {
5228 crReturnV;
ff3187f6 5229 } while (!pktin);
5230 if (pktin->type != SSH1_SMSG_SUCCESS
5231 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 5232 bombout(("Protocol confusion"));
7ffdbc1a 5233 crStopV;
ff3187f6 5234 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 5235 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 5236 }
4ba9b64b 5237 logevent("Started compression");
51470298 5238 ssh->v1_compressing = TRUE;
5366aed8 5239 ssh->cs_comp_ctx = zlib_compress_init();
5240 logevent("Initialised zlib (RFC1950) compression");
5241 ssh->sc_comp_ctx = zlib_decompress_init();
5242 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 5243 }
5244
fd5e5847 5245 /*
5246 * Start the shell or command.
5247 *
2e85c969 5248 * Special case: if the first-choice command is an SSH-2
fd5e5847 5249 * subsystem (hence not usable here) and the second choice
5250 * exists, we fall straight back to that.
5251 */
5252 {
4a693cfc 5253 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
fd5e5847 5254
4a693cfc 5255 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5256 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5257 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
51470298 5258 ssh->fallback_cmd = TRUE;
fd5e5847 5259 }
5260 if (*cmd)
51470298 5261 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 5262 else
51470298 5263 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 5264 logevent("Started session");
5265 }
374330e2 5266
51470298 5267 ssh->state = SSH_STATE_SESSION;
5268 if (ssh->size_needed)
5269 ssh_size(ssh, ssh->term_width, ssh->term_height);
5270 if (ssh->eof_needed)
5271 ssh_special(ssh, TS_EOF);
374330e2 5272
b9d7bcad 5273 if (ssh->ldisc)
5274 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5275 ssh->send_ok = 1;
5276 ssh->channels = newtree234(ssh_channelcmp);
374330e2 5277 while (1) {
d74d141c 5278
51df0ab5 5279 /*
5280 * By this point, most incoming packets are already being
5281 * handled by the dispatch table, and we need only pay
5282 * attention to the unusual ones.
5283 */
0357890f 5284
51df0ab5 5285 crReturnV;
5286 if (pktin) {
5287 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 5288 /* may be from EXEC_SHELL on some servers */
ff3187f6 5289 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 5290 /* may be from EXEC_SHELL on some servers
374330e2 5291 * if no pty is available or in other odd cases. Ignore */
374330e2 5292 } else {
ff3187f6 5293 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 5294 crStopV;
374330e2 5295 }
5296 } else {
8df7a775 5297 while (inlen > 0) {
5298 int len = min(inlen, 512);
a2724fba 5299 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5300 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
9a10ecf4 5301 PKTT_OTHER, PKT_END);
8df7a775 5302 in += len;
5303 inlen -= len;
5304 }
374330e2 5305 }
5306 }
5307
5308 crFinishV;
5309}
5310
5311/*
2e85c969 5312 * Handle the top-level SSH-2 protocol.
b09eaa88 5313 */
5314static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5315{
fb983202 5316 char *msg;
b09eaa88 5317 int msglen;
5318
5319 ssh_pkt_getstring(pktin, &msg, &msglen);
fb983202 5320 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 5321}
5322
5323static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5324{
5325 /* log reason code in disconnect message */
5326 char *msg;
5327 int msglen;
5328
5329 ssh_pkt_getstring(pktin, &msg, &msglen);
5330 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5331}
5332
409bfa77 5333static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
b09eaa88 5334{
5335 /* Do nothing, because we're ignoring it! Duhh. */
5336}
5337
5338static void ssh1_protocol_setup(Ssh ssh)
5339{
5340 int i;
5341
5342 /*
5343 * Most messages are handled by the coroutines.
5344 */
5345 for (i = 0; i < 256; i++)
5346 ssh->packet_dispatch[i] = NULL;
5347
5348 /*
5349 * These special message types we install handlers for.
5350 */
5351 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5352 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5353 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5354}
5355
1c1a7262 5356static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
b09eaa88 5357 struct Packet *pktin)
5358{
1c1a7262 5359 unsigned char *in=(unsigned char*)vin;
b09eaa88 5360 if (ssh->state == SSH_STATE_CLOSED)
5361 return;
5362
5363 if (pktin && ssh->packet_dispatch[pktin->type]) {
5364 ssh->packet_dispatch[pktin->type](ssh, pktin);
5365 return;
5366 }
5367
5368 if (!ssh->protocol_initial_phase_done) {
5369 if (do_ssh1_login(ssh, in, inlen, pktin))
5370 ssh->protocol_initial_phase_done = TRUE;
5371 else
5372 return;
5373 }
5374
5375 do_ssh1_connection(ssh, in, inlen, pktin);
5376}
5377
5378/*
e5574168 5379 * Utility routine for decoding comma-separated strings in KEXINIT.
5380 */
32874aea 5381static int in_commasep_string(char *needle, char *haystack, int haylen)
5382{
57356d63 5383 int needlen;
5384 if (!needle || !haystack) /* protect against null pointers */
5385 return 0;
5386 needlen = strlen(needle);
e5574168 5387 while (1) {
32874aea 5388 /*
5389 * Is it at the start of the string?
5390 */
5391 if (haylen >= needlen && /* haystack is long enough */
5392 !memcmp(needle, haystack, needlen) && /* initial match */
5393 (haylen == needlen || haystack[needlen] == ',')
5394 /* either , or EOS follows */
5395 )
5396 return 1;
5397 /*
5398 * If not, search for the next comma and resume after that.
5399 * If no comma found, terminate.
5400 */
5401 while (haylen > 0 && *haystack != ',')
5402 haylen--, haystack++;
5403 if (haylen == 0)
5404 return 0;
5405 haylen--, haystack++; /* skip over comma itself */
e5574168 5406 }
5407}
5408
5409/*
b59743d5 5410 * Similar routine for checking whether we have the first string in a list.
5411 */
5412static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5413{
5414 int needlen;
5415 if (!needle || !haystack) /* protect against null pointers */
5416 return 0;
5417 needlen = strlen(needle);
5418 /*
5419 * Is it at the start of the string?
5420 */
5421 if (haylen >= needlen && /* haystack is long enough */
5422 !memcmp(needle, haystack, needlen) && /* initial match */
5423 (haylen == needlen || haystack[needlen] == ',')
5424 /* either , or EOS follows */
5425 )
5426 return 1;
5427 return 0;
5428}
5429
5430
5431/*
2e85c969 5432 * SSH-2 key creation method.
754c0df9 5433 * (Currently assumes 2 lots of any hash are sufficient to generate
5434 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
d39f364a 5435 */
754c0df9 5436#define SSH2_MKKEY_ITERS (2)
b672f405 5437static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
d8baa528 5438 unsigned char *keyspace)
32874aea 5439{
b672f405 5440 const struct ssh_hash *h = ssh->kex->hash;
5441 void *s;
5442 /* First hlen bytes. */
5443 s = h->init();
51470298 5444 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5445 hash_mpint(h, s, K);
5446 h->bytes(s, H, h->hlen);
5447 h->bytes(s, &chr, 1);
5448 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5449 h->final(s, keyspace);
5450 /* Next hlen bytes. */
5451 s = h->init();
51470298 5452 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5453 hash_mpint(h, s, K);
5454 h->bytes(s, H, h->hlen);
5455 h->bytes(s, keyspace, h->hlen);
5456 h->final(s, keyspace + h->hlen);
d39f364a 5457}
5458
5459/*
2e85c969 5460 * Handle the SSH-2 transport layer.
e5574168 5461 */
1c1a7262 5462static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
ff3187f6 5463 struct Packet *pktin)
e5574168 5464{
1c1a7262 5465 unsigned char *in = (unsigned char *)vin;
51470298 5466 struct do_ssh2_transport_state {
4763c1c2 5467 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
51470298 5468 Bignum p, g, e, f, K;
3dc9a6a7 5469 void *our_kexinit;
5470 int our_kexinitlen;
51470298 5471 int kex_init_value, kex_reply_value;
5472 const struct ssh_mac **maclist;
5473 int nmacs;
5474 const struct ssh2_cipher *cscipher_tobe;
5475 const struct ssh2_cipher *sccipher_tobe;
5476 const struct ssh_mac *csmac_tobe;
5477 const struct ssh_mac *scmac_tobe;
5478 const struct ssh_compress *cscomp_tobe;
5479 const struct ssh_compress *sccomp_tobe;
fae1a71b 5480 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5481 int hostkeylen, siglen, rsakeylen;
51470298 5482 void *hkey; /* actual host key */
fae1a71b 5483 void *rsakey; /* for RSA kex */
754c0df9 5484 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
83e7d008 5485 int n_preferred_kex;
34557659 5486 const struct ssh_kexes *preferred_kex[KEX_MAX];
51470298 5487 int n_preferred_ciphers;
5488 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5489 const struct ssh_compress *preferred_comp;
ab18ccff 5490 int userauth_succeeded; /* for delayed compression */
5491 int pending_compression;
e13bba36 5492 int got_session_id, activated_authconn;
ff3187f6 5493 struct Packet *pktout;
3d9449a1 5494 int dlgret;
5495 int guessok;
4763c1c2 5496 int ignorepkt;
51470298 5497 };
5498 crState(do_ssh2_transport_state);
5499
5500 crBegin(ssh->do_ssh2_transport_crstate);
5501
5502 s->cscipher_tobe = s->sccipher_tobe = NULL;
5503 s->csmac_tobe = s->scmac_tobe = NULL;
5504 s->cscomp_tobe = s->sccomp_tobe = NULL;
5505
e13bba36 5506 s->got_session_id = s->activated_authconn = FALSE;
ab18ccff 5507 s->userauth_succeeded = FALSE;
5508 s->pending_compression = FALSE;
e5574168 5509
e13bba36 5510 /*
5511 * Be prepared to work around the buggy MAC problem.
5512 */
5513 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5514 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5515 else
5516 s->maclist = macs, s->nmacs = lenof(macs);
5517
5518 begin_key_exchange:
acab36bc 5519 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
51470298 5520 {
e13bba36 5521 int i, j, commalist_started;
5522
51470298 5523 /*
83e7d008 5524 * Set up the preferred key exchange. (NULL => warn below here)
5525 */
5526 s->n_preferred_kex = 0;
5527 for (i = 0; i < KEX_MAX; i++) {
4a693cfc 5528 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
83e7d008 5529 case KEX_DHGEX:
5530 s->preferred_kex[s->n_preferred_kex++] =
5531 &ssh_diffiehellman_gex;
5532 break;
5533 case KEX_DHGROUP14:
5534 s->preferred_kex[s->n_preferred_kex++] =
5535 &ssh_diffiehellman_group14;
5536 break;
5537 case KEX_DHGROUP1:
5538 s->preferred_kex[s->n_preferred_kex++] =
5539 &ssh_diffiehellman_group1;
5540 break;
fae1a71b 5541 case KEX_RSA:
5542 s->preferred_kex[s->n_preferred_kex++] =
5543 &ssh_rsa_kex;
5544 break;
754c0df9 5545 case KEX_WARN:
83e7d008 5546 /* Flag for later. Don't bother if it's the last in
5547 * the list. */
5548 if (i < KEX_MAX - 1) {
5549 s->preferred_kex[s->n_preferred_kex++] = NULL;
5550 }
5551 break;
5552 }
5553 }
83e7d008 5554
83e7d008 5555 /*
51470298 5556 * Set up the preferred ciphers. (NULL => warn below here)
5557 */
5558 s->n_preferred_ciphers = 0;
5559 for (i = 0; i < CIPHER_MAX; i++) {
4a693cfc 5560 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
51470298 5561 case CIPHER_BLOWFISH:
5562 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5563 break;
5564 case CIPHER_DES:
4a693cfc 5565 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
51470298 5566 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5567 }
5568 break;
5569 case CIPHER_3DES:
5570 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5571 break;
5572 case CIPHER_AES:
5573 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5574 break;
a2add208 5575 case CIPHER_ARCFOUR:
5576 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5577 break;
51470298 5578 case CIPHER_WARN:
5579 /* Flag for later. Don't bother if it's the last in
5580 * the list. */
5581 if (i < CIPHER_MAX - 1) {
5582 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5583 }
5584 break;
ca20bfcf 5585 }
ca20bfcf 5586 }
7591b9ff 5587
e13bba36 5588 /*
5589 * Set up preferred compression.
5590 */
4a693cfc 5591 if (conf_get_int(ssh->conf, CONF_compression))
e13bba36 5592 s->preferred_comp = &ssh_zlib;
5593 else
5594 s->preferred_comp = &ssh_comp_none;
51470298 5595
5596 /*
590f6a5f 5597 * Enable queueing of outgoing auth- or connection-layer
5598 * packets while we are in the middle of a key exchange.
5599 */
5600 ssh->queueing = TRUE;
5601
5602 /*
9442dd57 5603 * Flag that KEX is in progress.
5604 */
5605 ssh->kex_in_progress = TRUE;
5606
5607 /*
51470298 5608 * Construct and send our key exchange packet.
5609 */
ff3187f6 5610 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 5611 for (i = 0; i < 16; i++)
ff3187f6 5612 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 5613 /* List key exchange algorithms. */
ff3187f6 5614 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5615 commalist_started = 0;
5616 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5617 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5618 if (!k) continue; /* warning flag */
34557659 5619 for (j = 0; j < k->nkexes; j++) {
5620 if (commalist_started)
5621 ssh2_pkt_addstring_str(s->pktout, ",");
5622 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5623 commalist_started = 1;
5624 }
32874aea 5625 }
51470298 5626 /* List server host key algorithms. */
ff3187f6 5627 ssh2_pkt_addstring_start(s->pktout);
51470298 5628 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 5629 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 5630 if (i < lenof(hostkey_algs) - 1)
ff3187f6 5631 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 5632 }
51470298 5633 /* List client->server encryption algorithms. */
ff3187f6 5634 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5635 commalist_started = 0;
51470298 5636 for (i = 0; i < s->n_preferred_ciphers; i++) {
5637 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5638 if (!c) continue; /* warning flag */
5639 for (j = 0; j < c->nciphers; j++) {
83e7d008 5640 if (commalist_started)
ff3187f6 5641 ssh2_pkt_addstring_str(s->pktout, ",");
5642 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5643 commalist_started = 1;
51470298 5644 }
5645 }
5646 /* List server->client encryption algorithms. */
ff3187f6 5647 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5648 commalist_started = 0;
51470298 5649 for (i = 0; i < s->n_preferred_ciphers; i++) {
5650 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5651 if (!c) continue; /* warning flag */
5652 for (j = 0; j < c->nciphers; j++) {
83e7d008 5653 if (commalist_started)
ff3187f6 5654 ssh2_pkt_addstring_str(s->pktout, ",");
5655 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5656 commalist_started = 1;
51470298 5657 }
5658 }
5659 /* List client->server MAC algorithms. */
ff3187f6 5660 ssh2_pkt_addstring_start(s->pktout);
51470298 5661 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5662 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5663 if (i < s->nmacs - 1)
ff3187f6 5664 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5665 }
5666 /* List server->client MAC algorithms. */
ff3187f6 5667 ssh2_pkt_addstring_start(s->pktout);
51470298 5668 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5669 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5670 if (i < s->nmacs - 1)
ff3187f6 5671 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5672 }
ab18ccff 5673 /* List client->server compression algorithms,
5674 * then server->client compression algorithms. (We use the
5675 * same set twice.) */
5676 for (j = 0; j < 2; j++) {
5677 ssh2_pkt_addstring_start(s->pktout);
5678 assert(lenof(compressions) > 1);
5679 /* Prefer non-delayed versions */
5680 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5681 /* We don't even list delayed versions of algorithms until
5682 * they're allowed to be used, to avoid a race. See the end of
5683 * this function. */
5684 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
ff3187f6 5685 ssh2_pkt_addstring_str(s->pktout, ",");
ab18ccff 5686 ssh2_pkt_addstring_str(s->pktout,
5687 s->preferred_comp->delayed_name);
f6e0abe2 5688 }
ab18ccff 5689 for (i = 0; i < lenof(compressions); i++) {
5690 const struct ssh_compress *c = compressions[i];
5691 if (c != s->preferred_comp) {
5692 ssh2_pkt_addstring_str(s->pktout, ",");
5693 ssh2_pkt_addstring_str(s->pktout, c->name);
5694 if (s->userauth_succeeded && c->delayed_name) {
5695 ssh2_pkt_addstring_str(s->pktout, ",");
5696 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5697 }
5698 }
f6e0abe2 5699 }
51470298 5700 }
5701 /* List client->server languages. Empty list. */
ff3187f6 5702 ssh2_pkt_addstring_start(s->pktout);
51470298 5703 /* List server->client languages. Empty list. */
ff3187f6 5704 ssh2_pkt_addstring_start(s->pktout);
51470298 5705 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5706 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5707 /* Reserved. */
ff3187f6 5708 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5709 }
0db56f73 5710
3dc9a6a7 5711 s->our_kexinitlen = s->pktout->length - 5;
5712 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5713 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
0db56f73 5714
590f6a5f 5715 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5716
ff3187f6 5717 if (!pktin)
5718 crWaitUntil(pktin);
e5574168 5719
5720 /*
5721 * Now examine the other side's KEXINIT to see what we're up
5722 * to.
5723 */
51470298 5724 {
4763c1c2 5725 char *str, *preferred;
3d9449a1 5726 int i, j, len;
51470298 5727
ff3187f6 5728 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5729 bombout(("expected key exchange packet from server"));
7ffdbc1a 5730 crStop(0);
32874aea 5731 }
51470298 5732 ssh->kex = NULL;
5733 ssh->hostkey = NULL;
5734 s->cscipher_tobe = NULL;
5735 s->sccipher_tobe = NULL;
5736 s->csmac_tobe = NULL;
5737 s->scmac_tobe = NULL;
5738 s->cscomp_tobe = NULL;
5739 s->sccomp_tobe = NULL;
4763c1c2 5740 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5741
ff3187f6 5742 pktin->savedpos += 16; /* skip garbage cookie */
5743 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4763c1c2 5744
5745 preferred = NULL;
83e7d008 5746 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5747 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5748 if (!k) {
4763c1c2 5749 s->warn_kex = TRUE;
5750 } else {
34557659 5751 for (j = 0; j < k->nkexes; j++) {
5752 if (!preferred) preferred = k->list[j]->name;
5753 if (in_commasep_string(k->list[j]->name, str, len)) {
5754 ssh->kex = k->list[j];
5755 break;
5756 }
5757 }
83e7d008 5758 }
4763c1c2 5759 if (ssh->kex)
51470298 5760 break;
32874aea 5761 }
83e7d008 5762 if (!ssh->kex) {
5763 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5764 str ? str : "(null)"));
5765 crStop(0);
5766 }
b59743d5 5767 /*
5768 * Note that the server's guess is considered wrong if it doesn't match
5769 * the first algorithm in our list, even if it's still the algorithm
5770 * we end up using.
5771 */
4763c1c2 5772 s->guessok = first_in_commasep_string(preferred, str, len);
ff3187f6 5773 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5774 for (i = 0; i < lenof(hostkey_algs); i++) {
5775 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5776 ssh->hostkey = hostkey_algs[i];
5777 break;
5778 }
5779 }
3d9449a1 5780 s->guessok = s->guessok &&
b59743d5 5781 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5782 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5783 for (i = 0; i < s->n_preferred_ciphers; i++) {
5784 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5785 if (!c) {
4763c1c2 5786 s->warn_cscipher = TRUE;
51470298 5787 } else {
5788 for (j = 0; j < c->nciphers; j++) {
5789 if (in_commasep_string(c->list[j]->name, str, len)) {
5790 s->cscipher_tobe = c->list[j];
5791 break;
5792 }
ca20bfcf 5793 }
32874aea 5794 }
4763c1c2 5795 if (s->cscipher_tobe)
51470298 5796 break;
32874aea 5797 }
51470298 5798 if (!s->cscipher_tobe) {
6b5cf8b4 5799 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5800 str ? str : "(null)"));
7ffdbc1a 5801 crStop(0);
ca20bfcf 5802 }
0ef8f407 5803
ff3187f6 5804 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5805 for (i = 0; i < s->n_preferred_ciphers; i++) {
5806 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5807 if (!c) {
4763c1c2 5808 s->warn_sccipher = TRUE;
51470298 5809 } else {
5810 for (j = 0; j < c->nciphers; j++) {
5811 if (in_commasep_string(c->list[j]->name, str, len)) {
5812 s->sccipher_tobe = c->list[j];
5813 break;
5814 }
ca20bfcf 5815 }
32874aea 5816 }
4763c1c2 5817 if (s->sccipher_tobe)
51470298 5818 break;
32874aea 5819 }
51470298 5820 if (!s->sccipher_tobe) {
6b5cf8b4 5821 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5822 str ? str : "(null)"));
7ffdbc1a 5823 crStop(0);
ca20bfcf 5824 }
0ef8f407 5825
ff3187f6 5826 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5827 for (i = 0; i < s->nmacs; i++) {
5828 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5829 s->csmac_tobe = s->maclist[i];
5830 break;
5831 }
32874aea 5832 }
ff3187f6 5833 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5834 for (i = 0; i < s->nmacs; i++) {
5835 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5836 s->scmac_tobe = s->maclist[i];
5837 break;
5838 }
32874aea 5839 }
ff3187f6 5840 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5841 for (i = 0; i < lenof(compressions) + 1; i++) {
5842 const struct ssh_compress *c =
5843 i == 0 ? s->preferred_comp : compressions[i - 1];
5844 if (in_commasep_string(c->name, str, len)) {
5845 s->cscomp_tobe = c;
5846 break;
ab18ccff 5847 } else if (in_commasep_string(c->delayed_name, str, len)) {
5848 if (s->userauth_succeeded) {
5849 s->cscomp_tobe = c;
5850 break;
5851 } else {
5852 s->pending_compression = TRUE; /* try this later */
5853 }
51470298 5854 }
32874aea 5855 }
ff3187f6 5856 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5857 for (i = 0; i < lenof(compressions) + 1; i++) {
5858 const struct ssh_compress *c =
5859 i == 0 ? s->preferred_comp : compressions[i - 1];
5860 if (in_commasep_string(c->name, str, len)) {
5861 s->sccomp_tobe = c;
5862 break;
ab18ccff 5863 } else if (in_commasep_string(c->delayed_name, str, len)) {
5864 if (s->userauth_succeeded) {
5865 s->sccomp_tobe = c;
5866 break;
5867 } else {
5868 s->pending_compression = TRUE; /* try this later */
5869 }
51470298 5870 }
32874aea 5871 }
ab18ccff 5872 if (s->pending_compression) {
5873 logevent("Server supports delayed compression; "
5874 "will try this later");
5875 }
b59743d5 5876 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5877 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
4763c1c2 5878 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5879
5880 if (s->warn_kex) {
5881 ssh_set_frozen(ssh, 1);
5882 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5883 ssh->kex->name,
5884 ssh_dialog_callback, ssh);
5885 if (s->dlgret < 0) {
5886 do {
5887 crReturn(0);
5888 if (pktin) {
5889 bombout(("Unexpected data from server while"
5890 " waiting for user response"));
5891 crStop(0);
5892 }
5893 } while (pktin || inlen > 0);
5894 s->dlgret = ssh->user_response;
5895 }
5896 ssh_set_frozen(ssh, 0);
5897 if (s->dlgret == 0) {
9e296bfa 5898 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5899 0, TRUE);
a5a6f839 5900 crStop(0);
4763c1c2 5901 }
5902 }
5903
5904 if (s->warn_cscipher) {
5905 ssh_set_frozen(ssh, 1);
5906 s->dlgret = askalg(ssh->frontend,
5907 "client-to-server cipher",
5908 s->cscipher_tobe->name,
5909 ssh_dialog_callback, ssh);
5910 if (s->dlgret < 0) {
5911 do {
5912 crReturn(0);
5913 if (pktin) {
5914 bombout(("Unexpected data from server while"
5915 " waiting for user response"));
5916 crStop(0);
5917 }
5918 } while (pktin || inlen > 0);
5919 s->dlgret = ssh->user_response;
5920 }
5921 ssh_set_frozen(ssh, 0);
5922 if (s->dlgret == 0) {
9e296bfa 5923 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5924 0, TRUE);
a5a6f839 5925 crStop(0);
4763c1c2 5926 }
5927 }
5928
5929 if (s->warn_sccipher) {
5930 ssh_set_frozen(ssh, 1);
5931 s->dlgret = askalg(ssh->frontend,
5932 "server-to-client cipher",
5933 s->sccipher_tobe->name,
5934 ssh_dialog_callback, ssh);
5935 if (s->dlgret < 0) {
5936 do {
5937 crReturn(0);
5938 if (pktin) {
5939 bombout(("Unexpected data from server while"
5940 " waiting for user response"));
5941 crStop(0);
5942 }
5943 } while (pktin || inlen > 0);
5944 s->dlgret = ssh->user_response;
5945 }
5946 ssh_set_frozen(ssh, 0);
5947 if (s->dlgret == 0) {
9e296bfa 5948 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5949 0, TRUE);
a5a6f839 5950 crStop(0);
4763c1c2 5951 }
5952 }
5953
b672f405 5954 ssh->exhash = ssh->kex->hash->init();
5955 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5956 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5957 hash_string(ssh->kex->hash, ssh->exhash,
5958 s->our_kexinit, s->our_kexinitlen);
3dc9a6a7 5959 sfree(s->our_kexinit);
5960 if (pktin->length > 5)
b672f405 5961 hash_string(ssh->kex->hash, ssh->exhash,
5962 pktin->data + 5, pktin->length - 5);
3dc9a6a7 5963
4763c1c2 5964 if (s->ignorepkt) /* first_kex_packet_follows */
b59743d5 5965 crWaitUntil(pktin); /* Ignore packet */
e5574168 5966 }
e5574168 5967
fae1a71b 5968 if (ssh->kex->main_type == KEXTYPE_DH) {
30774ba3 5969 /*
5970 * Work out the number of bits of key we will need from the
5971 * key exchange. We start with the maximum key length of
5972 * either cipher...
5973 */
5974 {
5975 int csbits, scbits;
5976
5977 csbits = s->cscipher_tobe->keylen;
5978 scbits = s->sccipher_tobe->keylen;
5979 s->nbits = (csbits > scbits ? csbits : scbits);
5980 }
5981 /* The keys only have hlen-bit entropy, since they're based on
5982 * a hash. So cap the key size at hlen bits. */
5983 if (s->nbits > ssh->kex->hash->hlen * 8)
5984 s->nbits = ssh->kex->hash->hlen * 8;
5985
5986 /*
5987 * If we're doing Diffie-Hellman group exchange, start by
5988 * requesting a group.
5989 */
5990 if (!ssh->kex->pdata) {
5991 logevent("Doing Diffie-Hellman group exchange");
acab36bc 5992 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
30774ba3 5993 /*
5994 * Work out how big a DH group we will need to allow that
5995 * much data.
5996 */
5997 s->pbits = 512 << ((s->nbits - 1) / 64);
5998 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5999 ssh2_pkt_adduint32(s->pktout, s->pbits);
6000 ssh2_pkt_send_noqueue(ssh, s->pktout);
6001
6002 crWaitUntil(pktin);
6003 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6004 bombout(("expected key exchange group packet from server"));
6005 crStop(0);
6006 }
6007 s->p = ssh2_pkt_getmp(pktin);
6008 s->g = ssh2_pkt_getmp(pktin);
6009 if (!s->p || !s->g) {
6010 bombout(("unable to read mp-ints from incoming group packet"));
6011 crStop(0);
6012 }
6013 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6014 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6015 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6016 } else {
acab36bc 6017 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
30774ba3 6018 ssh->kex_ctx = dh_setup_group(ssh->kex);
6019 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6020 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6021 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6022 ssh->kex->groupname);
6023 }
e5574168 6024
30774ba3 6025 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6026 ssh->kex->hash->text_name);
6027 /*
6028 * Now generate and send e for Diffie-Hellman.
6029 */
6030 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6031 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6032 s->pktout = ssh2_pkt_init(s->kex_init_value);
6033 ssh2_pkt_addmp(s->pktout, s->e);
6034 ssh2_pkt_send_noqueue(ssh, s->pktout);
6035
6036 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6037 crWaitUntil(pktin);
6038 if (pktin->type != s->kex_reply_value) {
6039 bombout(("expected key exchange reply packet from server"));
6040 crStop(0);
6041 }
6042 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6043 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6044 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6045 s->f = ssh2_pkt_getmp(pktin);
6046 if (!s->f) {
6047 bombout(("unable to parse key exchange reply packet"));
6048 crStop(0);
6049 }
6050 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 6051
30774ba3 6052 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 6053
30774ba3 6054 /* We assume everything from now on will be quick, and it might
6055 * involve user interaction. */
6056 set_busy_status(ssh->frontend, BUSY_NOT);
755e0524 6057
30774ba3 6058 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6059 if (!ssh->kex->pdata) {
6060 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6061 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6062 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6063 }
6064 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6065 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6066
6067 dh_cleanup(ssh->kex_ctx);
6068 freebn(s->f);
6069 if (!ssh->kex->pdata) {
6070 freebn(s->g);
6071 freebn(s->p);
6072 }
fae1a71b 6073 } else {
6074 logeventf(ssh, "Doing RSA key exchange with hash %s",
6075 ssh->kex->hash->text_name);
acab36bc 6076 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
fae1a71b 6077 /*
6078 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6079 * from the server.
6080 */
6081 crWaitUntil(pktin);
6082 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6083 bombout(("expected RSA public key packet from server"));
6084 crStop(0);
6085 }
6086
6087 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6088 hash_string(ssh->kex->hash, ssh->exhash,
6089 s->hostkeydata, s->hostkeylen);
6090 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6091
6092 {
6093 char *keydata;
6094 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6095 s->rsakeydata = snewn(s->rsakeylen, char);
6096 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6097 }
6098
6099 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6100 if (!s->rsakey) {
6101 sfree(s->rsakeydata);
6102 bombout(("unable to parse RSA public key from server"));
6103 crStop(0);
6104 }
6105
6106 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6107
6108 /*
6109 * Next, set up a shared secret K, of precisely KLEN -
6110 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6111 * RSA key modulus and HLEN is the bit length of the hash
6112 * we're using.
6113 */
6114 {
6115 int klen = ssh_rsakex_klen(s->rsakey);
6116 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6117 int i, byte = 0;
6118 unsigned char *kstr1, *kstr2, *outstr;
6119 int kstr1len, kstr2len, outstrlen;
6120
6121 s->K = bn_power_2(nbits - 1);
6122
6123 for (i = 0; i < nbits; i++) {
6124 if ((i & 7) == 0) {
6125 byte = random_byte();
6126 }
6127 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6128 }
6129
6130 /*
6131 * Encode this as an mpint.
6132 */
6133 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6134 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6135 PUT_32BIT(kstr2, kstr1len);
6136 memcpy(kstr2 + 4, kstr1, kstr1len);
6137
6138 /*
6139 * Encrypt it with the given RSA key.
6140 */
6141 outstrlen = (klen + 7) / 8;
6142 outstr = snewn(outstrlen, unsigned char);
6143 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6144 outstr, outstrlen, s->rsakey);
6145
6146 /*
6147 * And send it off in a return packet.
6148 */
6149 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6150 ssh2_pkt_addstring_start(s->pktout);
7108a872 6151 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
fae1a71b 6152 ssh2_pkt_send_noqueue(ssh, s->pktout);
6153
6154 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6155
6156 sfree(kstr2);
6157 sfree(kstr1);
6158 sfree(outstr);
6159 }
6160
6161 ssh_rsakex_freekey(s->rsakey);
6162
6163 crWaitUntil(pktin);
6164 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6165 sfree(s->rsakeydata);
6166 bombout(("expected signature packet from server"));
6167 crStop(0);
6168 }
6169
6170 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6171
6172 sfree(s->rsakeydata);
6173 }
6174
b672f405 6175 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6176 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6177 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
e5574168 6178
fabd1805 6179 ssh->kex_ctx = NULL;
3709bfe9 6180
7cca0d81 6181#if 0
765c4200 6182 debug(("Exchange hash is:\n"));
b672f405 6183 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7cca0d81 6184#endif
6185
51470298 6186 if (!s->hkey ||
6187 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
b672f405 6188 (char *)s->exchange_hash,
6189 ssh->kex->hash->hlen)) {
6b5cf8b4 6190 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 6191 crStop(0);
8d5de777 6192 }
e5574168 6193
6194 /*
7cca0d81 6195 * Authenticate remote host: verify host key. (We've already
6196 * checked the signature of the exchange hash.)
e5574168 6197 */
51470298 6198 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6199 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 6200 ssh_set_frozen(ssh, 1);
6201 s->dlgret = verify_ssh_host_key(ssh->frontend,
6202 ssh->savedhost, ssh->savedport,
6203 ssh->hostkey->keytype, s->keystr,
6204 s->fingerprint,
6205 ssh_dialog_callback, ssh);
6206 if (s->dlgret < 0) {
6207 do {
6208 crReturn(0);
6209 if (pktin) {
6210 bombout(("Unexpected data from server while waiting"
6211 " for user host key response"));
6212 crStop(0);
6213 }
6214 } while (pktin || inlen > 0);
6215 s->dlgret = ssh->user_response;
6216 }
6217 ssh_set_frozen(ssh, 0);
6218 if (s->dlgret == 0) {
9e296bfa 6219 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6220 0, TRUE);
3d9449a1 6221 crStop(0);
6222 }
e13bba36 6223 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 6224 logevent("Host key fingerprint is:");
51470298 6225 logevent(s->fingerprint);
5e0d7cb8 6226 }
51470298 6227 sfree(s->fingerprint);
6228 sfree(s->keystr);
6229 ssh->hostkey->freekey(s->hkey);
d39f364a 6230
6231 /*
9442dd57 6232 * The exchange hash from the very first key exchange is also
6233 * the session id, used in session key construction and
6234 * authentication.
6235 */
e13bba36 6236 if (!s->got_session_id) {
b672f405 6237 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
9442dd57 6238 memcpy(ssh->v2_session_id, s->exchange_hash,
6239 sizeof(s->exchange_hash));
b672f405 6240 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6052bb76 6241 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
e13bba36 6242 s->got_session_id = TRUE;
6243 }
9442dd57 6244
6245 /*
7cca0d81 6246 * Send SSH2_MSG_NEWKEYS.
d39f364a 6247 */
ff3187f6 6248 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 6249 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 6250 ssh->outgoing_data_size = 0; /* start counting from here */
6251
6252 /*
6253 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 6254 * client-to-server session keys.
9442dd57 6255 */
6256 if (ssh->cs_cipher_ctx)
6257 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6258 ssh->cscipher = s->cscipher_tobe;
6259 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6260
6261 if (ssh->cs_mac_ctx)
6262 ssh->csmac->free_context(ssh->cs_mac_ctx);
6263 ssh->csmac = s->csmac_tobe;
6264 ssh->cs_mac_ctx = ssh->csmac->make_context();
6265
6266 if (ssh->cs_comp_ctx)
6267 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6268 ssh->cscomp = s->cscomp_tobe;
6269 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6270
6271 /*
6272 * Set IVs on client-to-server keys. Here we use the exchange
6273 * hash from the _first_ key exchange.
6274 */
6275 {
754c0df9 6276 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6277 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6278 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
754c0df9 6279 assert((ssh->cscipher->keylen+7) / 8 <=
6280 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6281 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
b672f405 6282 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
754c0df9 6283 assert(ssh->cscipher->blksize <=
6284 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6285 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
b672f405 6286 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
754c0df9 6287 assert(ssh->csmac->len <=
6288 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 6289 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
754c0df9 6290 memset(keyspace, 0, sizeof(keyspace));
9442dd57 6291 }
6292
6293 logeventf(ssh, "Initialised %.200s client->server encryption",
6294 ssh->cscipher->text_name);
6295 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6296 ssh->csmac->text_name);
6297 if (ssh->cscomp->text_name)
6298 logeventf(ssh, "Initialised %s compression",
6299 ssh->cscomp->text_name);
590f6a5f 6300
6301 /*
6302 * Now our end of the key exchange is complete, we can send all
6303 * our queued higher-layer packets.
6304 */
6305 ssh->queueing = FALSE;
6306 ssh2_pkt_queuesend(ssh);
d39f364a 6307
6308 /*
8406eaf9 6309 * Expect SSH2_MSG_NEWKEYS from server.
6310 */
ff3187f6 6311 crWaitUntil(pktin);
6312 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 6313 bombout(("expected new-keys packet from server"));
7ffdbc1a 6314 crStop(0);
8406eaf9 6315 }
9442dd57 6316 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 6317
6318 /*
9442dd57 6319 * We've seen server NEWKEYS, so create and initialise
6320 * server-to-client session keys.
d39f364a 6321 */
371e569c 6322 if (ssh->sc_cipher_ctx)
6323 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 6324 ssh->sccipher = s->sccipher_tobe;
371e569c 6325 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 6326
e0e1a00d 6327 if (ssh->sc_mac_ctx)
6328 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 6329 ssh->scmac = s->scmac_tobe;
e0e1a00d 6330 ssh->sc_mac_ctx = ssh->scmac->make_context();
6331
5366aed8 6332 if (ssh->sc_comp_ctx)
6333 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 6334 ssh->sccomp = s->sccomp_tobe;
5366aed8 6335 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6336
d39f364a 6337 /*
9442dd57 6338 * Set IVs on server-to-client keys. Here we use the exchange
6339 * hash from the _first_ key exchange.
d39f364a 6340 */
51470298 6341 {
754c0df9 6342 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6343 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6344 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
754c0df9 6345 assert((ssh->sccipher->keylen+7) / 8 <=
6346 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6347 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
b672f405 6348 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
754c0df9 6349 assert(ssh->sccipher->blksize <=
6350 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6351 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
b672f405 6352 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
754c0df9 6353 assert(ssh->scmac->len <=
6354 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
e0e1a00d 6355 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
754c0df9 6356 memset(keyspace, 0, sizeof(keyspace));
51470298 6357 }
57356d63 6358 logeventf(ssh, "Initialised %.200s server->client encryption",
6359 ssh->sccipher->text_name);
6c135243 6360 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6361 ssh->scmac->text_name);
57356d63 6362 if (ssh->sccomp->text_name)
6363 logeventf(ssh, "Initialised %s decompression",
6364 ssh->sccomp->text_name);
9442dd57 6365
6366 /*
fae1a71b 6367 * Free shared secret.
9442dd57 6368 */
679539d7 6369 freebn(s->K);
d39f364a 6370
033b4cef 6371 /*
e13bba36 6372 * Key exchange is over. Loop straight back round if we have a
6373 * deferred rekey reason.
6374 */
6375 if (ssh->deferred_rekey_reason) {
6376 logevent(ssh->deferred_rekey_reason);
6377 pktin = NULL;
6378 ssh->deferred_rekey_reason = NULL;
6379 goto begin_key_exchange;
6380 }
6381
6382 /*
6383 * Otherwise, schedule a timer for our next rekey.
9442dd57 6384 */
6385 ssh->kex_in_progress = FALSE;
e6c1536e 6386 ssh->last_rekey = GETTICKCOUNT();
4a693cfc 6387 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6388 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
d57f70af 6389 ssh2_timer, ssh);
e13bba36 6390
9442dd57 6391 /*
0db56f73 6392 * If this is the first key exchange phase, we must pass the
6393 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6394 * wants to see it but because it will need time to initialise
6395 * itself before it sees an actual packet. In subsequent key
6396 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6397 * it would only confuse the layer above.
6398 */
e13bba36 6399 if (s->activated_authconn) {
0e3607ed 6400 crReturn(0);
0db56f73 6401 }
e13bba36 6402 s->activated_authconn = TRUE;
0db56f73 6403
6404 /*
7cca0d81 6405 * Now we're encrypting. Begin returning 1 to the protocol main
6406 * function so that other things can run on top of the
6407 * transport. If we ever see a KEXINIT, we must go back to the
6408 * start.
9442dd57 6409 *
6410 * We _also_ go back to the start if we see pktin==NULL and
ab18ccff 6411 * inlen negative, because this is a special signal meaning
9442dd57 6412 * `initiate client-driven rekey', and `in' contains a message
6413 * giving the reason for the rekey.
ab18ccff 6414 *
6415 * inlen==-1 means always initiate a rekey;
6416 * inlen==-2 means that userauth has completed successfully and
6417 * we should consider rekeying (for delayed compression).
033b4cef 6418 */
9442dd57 6419 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
ab18ccff 6420 (!pktin && inlen < 0))) {
f382c87d 6421 wait_for_rekey:
32874aea 6422 crReturn(1);
e96adf72 6423 }
9442dd57 6424 if (pktin) {
6425 logevent("Server initiated key re-exchange");
6426 } else {
ab18ccff 6427 if (inlen == -2) {
6428 /*
6429 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6430 * delayed compression, if it's available.
6431 *
6432 * draft-miller-secsh-compression-delayed-00 says that you
6433 * negotiate delayed compression in the first key exchange, and
6434 * both sides start compressing when the server has sent
6435 * USERAUTH_SUCCESS. This has a race condition -- the server
6436 * can't know when the client has seen it, and thus which incoming
6437 * packets it should treat as compressed.
6438 *
6439 * Instead, we do the initial key exchange without offering the
6440 * delayed methods, but note if the server offers them; when we
6441 * get here, if a delayed method was available that was higher
6442 * on our list than what we got, we initiate a rekey in which we
6443 * _do_ list the delayed methods (and hopefully get it as a
6444 * result). Subsequent rekeys will do the same.
6445 */
6446 assert(!s->userauth_succeeded); /* should only happen once */
6447 s->userauth_succeeded = TRUE;
6448 if (!s->pending_compression)
6449 /* Can't see any point rekeying. */
6450 goto wait_for_rekey; /* this is utterly horrid */
6451 /* else fall through to rekey... */
6452 s->pending_compression = FALSE;
6453 }
f382c87d 6454 /*
ab18ccff 6455 * Now we've decided to rekey.
6456 *
f382c87d 6457 * Special case: if the server bug is set that doesn't
6458 * allow rekeying, we give a different log message and
6459 * continue waiting. (If such a server _initiates_ a rekey,
6460 * we process it anyway!)
6461 */
6462 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6463 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6464 (char *)in);
6465 /* Reset the counters, so that at least this message doesn't
6466 * hit the event log _too_ often. */
6467 ssh->outgoing_data_size = 0;
6468 ssh->incoming_data_size = 0;
4a693cfc 6469 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
f382c87d 6470 ssh->next_rekey =
4a693cfc 6471 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
f382c87d 6472 ssh2_timer, ssh);
6473 }
ab18ccff 6474 goto wait_for_rekey; /* this is still utterly horrid */
f382c87d 6475 } else {
6476 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 6477 }
9442dd57 6478 }
7cca0d81 6479 goto begin_key_exchange;
e5574168 6480
6481 crFinish(1);
6482}
6483
7cca0d81 6484/*
2e85c969 6485 * Add data to an SSH-2 channel output buffer.
783415f8 6486 */
32874aea 6487static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6488 int len)
6489{
5471d09a 6490 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 6491}
6492
6493/*
2e85c969 6494 * Attempt to send data on an SSH-2 channel.
783415f8 6495 */
5471d09a 6496static int ssh2_try_send(struct ssh_channel *c)
32874aea 6497{
51470298 6498 Ssh ssh = c->ssh;
ff3187f6 6499 struct Packet *pktout;
bc06669b 6500 int ret;
51470298 6501
5471d09a 6502 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6503 int len;
6504 void *data;
6505 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6506 if ((unsigned)len > c->v.v2.remwindow)
6507 len = c->v.v2.remwindow;
6508 if ((unsigned)len > c->v.v2.remmaxpkt)
6509 len = c->v.v2.remmaxpkt;
ff3187f6 6510 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6511 ssh2_pkt_adduint32(pktout, c->remoteid);
ff3187f6 6512 ssh2_pkt_addstring_start(pktout);
a2724fba 6513 dont_log_data(ssh, pktout, PKTLOG_OMIT);
ff3187f6 6514 ssh2_pkt_addstring_data(pktout, data, len);
6515 end_log_omission(ssh, pktout);
6516 ssh2_pkt_send(ssh, pktout);
5471d09a 6517 bufchain_consume(&c->v.v2.outbuffer, len);
6518 c->v.v2.remwindow -= len;
6519 }
6520
6521 /*
6522 * After having sent as much data as we can, return the amount
6523 * still buffered.
6524 */
bc06669b 6525 ret = bufchain_size(&c->v.v2.outbuffer);
6526
6527 /*
6528 * And if there's no data pending but we need to send an EOF, send
6529 * it.
6530 */
6531 if (!ret && c->pending_eof)
6532 ssh_channel_try_eof(c);
6533
6534 return ret;
5471d09a 6535}
6536
78280721 6537static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
1bfc7e93 6538{
6539 int bufsize;
bc06669b 6540 if (c->closes & CLOSES_SENT_EOF)
6541 return; /* don't send on channels we've EOFed */
1bfc7e93 6542 bufsize = ssh2_try_send(c);
6543 if (bufsize == 0) {
6544 switch (c->type) {
6545 case CHAN_MAINSESSION:
6546 /* stdin need not receive an unthrottle
6547 * notification since it will be polled */
6548 break;
6549 case CHAN_X11:
6550 x11_unthrottle(c->u.x11.s);
6551 break;
6552 case CHAN_AGENT:
6553 /* agent sockets are request/response and need no
6554 * buffer management */
6555 break;
6556 case CHAN_SOCKDATA:
6557 pfd_unthrottle(c->u.pfd.s);
6558 break;
6559 }
6560 }
6561}
6562
5471d09a 6563/*
94bdfe40 6564 * Set up most of a new ssh_channel for SSH-2.
6565 */
6566static void ssh2_channel_init(struct ssh_channel *c)
6567{
6568 Ssh ssh = c->ssh;
6569 c->localid = alloc_channel_id(ssh);
6570 c->closes = 0;
bc06669b 6571 c->pending_eof = FALSE;
94bdfe40 6572 c->throttling_conn = FALSE;
6573 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
4a693cfc 6574 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
94bdfe40 6575 c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL;
6576 c->v.v2.throttle_state = UNTHROTTLED;
6577 bufchain_init(&c->v.v2.outbuffer);
6578}
6579
6580/*
2e85c969 6581 * Potentially enlarge the window on an SSH-2 channel.
5471d09a 6582 */
9fca3f8c 6583static void ssh2_set_window(struct ssh_channel *c, int newwin)
5471d09a 6584{
51470298 6585 Ssh ssh = c->ssh;
6586
6b69f42e 6587 /*
bc06669b 6588 * Never send WINDOW_ADJUST for a channel that the remote side has
6589 * already sent EOF on; there's no point, since it won't be
beff003a 6590 * sending any more data anyway. Ditto if _we've_ already sent
6591 * CLOSE.
6b69f42e 6592 */
beff003a 6593 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6b69f42e 6594 return;
6595
d252310a 6596 /*
c9739dba 6597 * If the remote end has a habit of ignoring maxpkt, limit the
6598 * window so that it has no choice (assuming it doesn't ignore the
6599 * window as well).
6600 */
6601 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6602 newwin = OUR_V2_MAXPKT;
c9739dba 6603
6604 /*
d252310a 6605 * Only send a WINDOW_ADJUST if there's significantly more window
6606 * available than the other end thinks there is. This saves us
6607 * sending a WINDOW_ADJUST for every character in a shell session.
6608 *
6609 * "Significant" is arbitrarily defined as half the window size.
6610 */
3361b80a 6611 if (newwin / 2 >= c->v.v2.locwindow) {
ff3187f6 6612 struct Packet *pktout;
0e443c99 6613 struct winadj *wa;
ff3187f6 6614
0e443c99 6615 /*
6616 * In order to keep track of how much window the client
6617 * actually has available, we'd like it to acknowledge each
6618 * WINDOW_ADJUST. We can't do that directly, so we accompany
6619 * it with a CHANNEL_REQUEST that has to be acknowledged.
6620 *
6621 * This is only necessary if we're opening the window wide.
6622 * If we're not, then throughput is being constrained by
6623 * something other than the maximum window size anyway.
6624 *
6625 * We also only send this if the main channel has finished its
6626 * initial CHANNEL_REQUESTs and installed the default
6627 * CHANNEL_FAILURE handler, so as not to risk giving it
6628 * unexpected CHANNEL_FAILUREs.
6629 */
6630 if (newwin == c->v.v2.locmaxwin &&
6631 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) {
6632 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6633 ssh2_pkt_adduint32(pktout, c->remoteid);
6634 ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");
6635 ssh2_pkt_addbool(pktout, TRUE);
6636 ssh2_pkt_send(ssh, pktout);
6637
6638 /*
6639 * CHANNEL_FAILURE doesn't come with any indication of
6640 * what message caused it, so we have to keep track of the
6641 * outstanding CHANNEL_REQUESTs ourselves.
6642 */
6643 wa = snew(struct winadj);
6644 wa->size = newwin - c->v.v2.locwindow;
6645 wa->next = NULL;
6646 if (!c->v.v2.winadj_head)
6647 c->v.v2.winadj_head = wa;
6648 else
6649 c->v.v2.winadj_tail->next = wa;
6650 c->v.v2.winadj_tail = wa;
6651 if (c->v.v2.throttle_state != UNTHROTTLED)
6652 c->v.v2.throttle_state = UNTHROTTLING;
6653 } else {
6654 /* Pretend the WINDOW_ADJUST was acked immediately. */
6655 c->v.v2.remlocwin = newwin;
6656 c->v.v2.throttle_state = THROTTLED;
6657 }
ff3187f6 6658 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6659 ssh2_pkt_adduint32(pktout, c->remoteid);
6660 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6661 ssh2_pkt_send(ssh, pktout);
5471d09a 6662 c->v.v2.locwindow = newwin;
783415f8 6663 }
6664}
6665
e223b7c7 6666/*
6667 * Find the channel associated with a message. If there's no channel,
6668 * or it's not properly open, make a noise about it and return NULL.
6669 */
6670static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6671{
6672 unsigned localid = ssh_pkt_getuint32(pktin);
6673 struct ssh_channel *c;
6674
6675 c = find234(ssh->channels, &localid, ssh_channelfind);
6676 if (!c ||
6677 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6678 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6679 char *buf = dupprintf("Received %s for %s channel %u",
6680 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6681 pktin->type),
6682 c ? "half-open" : "nonexistent", localid);
6683 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6684 sfree(buf);
6685 return NULL;
6686 }
6687 return c;
6688}
6689
e030765f 6690static int ssh2_handle_winadj_response(struct ssh_channel *c)
6691{
6692 struct winadj *wa = c->v.v2.winadj_head;
6693 if (!wa)
6694 return FALSE;
6695 c->v.v2.winadj_head = wa->next;
6696 c->v.v2.remlocwin += wa->size;
6697 sfree(wa);
6698 /*
6699 * winadj messages are only sent when the window is fully open, so
6700 * if we get an ack of one, we know any pending unthrottle is
6701 * complete.
6702 */
6703 if (c->v.v2.throttle_state == UNTHROTTLING)
6704 c->v.v2.throttle_state = UNTHROTTLED;
997097db 6705 /*
6706 * We may now initiate channel-closing procedures, if that winadj
6707 * was the last thing outstanding before we send CHANNEL_CLOSE.
6708 */
6709 ssh2_channel_check_close(c);
e030765f 6710 return TRUE;
6711}
6712
837d6ba6 6713static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin)
6714{
6715 /*
6716 * This should never get called. All channel requests are either
e030765f 6717 * sent with want_reply false, are sent before this handler gets
6718 * installed, or are "winadj@putty" requests, which servers should
6719 * never respond to with success.
6720 *
6721 * However, at least one server ("boks_sshd") is known to return
6722 * SUCCESS for channel requests it's never heard of, such as
6723 * "winadj@putty". Raised with foxt.com as bug 090916-090424, but
6724 * for the sake of a quiet life, we handle it just the same as the
6725 * expected FAILURE.
837d6ba6 6726 */
6727 struct ssh_channel *c;
837d6ba6 6728
6729 c = ssh2_channel_msg(ssh, pktin);
6730 if (!c)
6731 return;
e030765f 6732 if (!ssh2_handle_winadj_response(c))
837d6ba6 6733 ssh_disconnect(ssh, NULL,
6734 "Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
6735 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6736}
6737
0e443c99 6738static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin)
6739{
6740 /*
6741 * The only time this should get called is for "winadj@putty"
6742 * messages sent above. All other channel requests are either
6743 * sent with want_reply false or are sent before this handler gets
6744 * installed.
6745 */
0e443c99 6746 struct ssh_channel *c;
0e443c99 6747
e223b7c7 6748 c = ssh2_channel_msg(ssh, pktin);
0e443c99 6749 if (!c)
e223b7c7 6750 return;
e030765f 6751 if (!ssh2_handle_winadj_response(c))
837d6ba6 6752 ssh_disconnect(ssh, NULL,
6753 "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
6754 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
0e443c99 6755}
6756
51df0ab5 6757static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 6758{
b09eaa88 6759 struct ssh_channel *c;
e223b7c7 6760 c = ssh2_channel_msg(ssh, pktin);
6761 if (!c)
6762 return;
bc06669b 6763 if (!(c->closes & CLOSES_SENT_EOF)) {
b09eaa88 6764 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
78280721 6765 ssh2_try_send_and_unthrottle(ssh, c);
1bfc7e93 6766 }
b09eaa88 6767}
6768
51df0ab5 6769static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6770{
6771 char *data;
6d44acc9 6772 int length;
51df0ab5 6773 struct ssh_channel *c;
e223b7c7 6774 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 6775 if (!c)
e223b7c7 6776 return;
51df0ab5 6777 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6778 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6779 return; /* extended but not stderr */
6780 ssh_pkt_getstring(pktin, &data, &length);
6781 if (data) {
6782 int bufsize = 0;
6783 c->v.v2.locwindow -= length;
0e443c99 6784 c->v.v2.remlocwin -= length;
51df0ab5 6785 switch (c->type) {
6786 case CHAN_MAINSESSION:
6787 bufsize =
6788 from_backend(ssh->frontend, pktin->type ==
6789 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6790 data, length);
6791 break;
6792 case CHAN_X11:
6793 bufsize = x11_send(c->u.x11.s, data, length);
6794 break;
6795 case CHAN_SOCKDATA:
6796 bufsize = pfd_send(c->u.pfd.s, data, length);
6797 break;
6798 case CHAN_AGENT:
6799 while (length > 0) {
6800 if (c->u.a.lensofar < 4) {
62ddb51e 6801 unsigned int l = min(4 - c->u.a.lensofar,
6802 (unsigned)length);
51df0ab5 6803 memcpy(c->u.a.msglen + c->u.a.lensofar,
6804 data, l);
6805 data += l;
6806 length -= l;
6807 c->u.a.lensofar += l;
6808 }
6809 if (c->u.a.lensofar == 4) {
6810 c->u.a.totallen =
6811 4 + GET_32BIT(c->u.a.msglen);
6812 c->u.a.message = snewn(c->u.a.totallen,
6813 unsigned char);
6814 memcpy(c->u.a.message, c->u.a.msglen, 4);
6815 }
6816 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 6817 unsigned int l =
51df0ab5 6818 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 6819 (unsigned)length);
51df0ab5 6820 memcpy(c->u.a.message + c->u.a.lensofar,
6821 data, l);
6822 data += l;
6823 length -= l;
6824 c->u.a.lensofar += l;
6825 }
6826 if (c->u.a.lensofar == c->u.a.totallen) {
6827 void *reply;
6828 int replylen;
6829 if (agent_query(c->u.a.message,
6830 c->u.a.totallen,
6831 &reply, &replylen,
6832 ssh_agentf_callback, c))
6833 ssh_agentf_callback(c, reply, replylen);
6834 sfree(c->u.a.message);
bc06669b 6835 c->u.a.message = NULL;
51df0ab5 6836 c->u.a.lensofar = 0;
6837 }
6838 }
6839 bufsize = 0;
6840 break;
6841 }
6842 /*
0e443c99 6843 * If it looks like the remote end hit the end of its window,
6844 * and we didn't want it to do that, think about using a
6845 * larger window.
6846 */
6847 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6848 c->v.v2.locmaxwin < 0x40000000)
6849 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6850 /*
51df0ab5 6851 * If we are not buffering too much data,
6852 * enlarge the window again at the remote side.
467e064d 6853 * If we are buffering too much, we may still
6854 * need to adjust the window if the server's
6855 * sent excess data.
51df0ab5 6856 */
9b53e9b8 6857 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6858 c->v.v2.locmaxwin - bufsize : 0);
ff68564b 6859 /*
6860 * If we're either buffering way too much data, or if we're
6861 * buffering anything at all and we're in "simple" mode,
6862 * throttle the whole channel.
6863 */
6864 if ((bufsize > c->v.v2.locmaxwin ||
4a693cfc 6865 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
ff68564b 6866 !c->throttling_conn) {
6867 c->throttling_conn = 1;
6868 ssh_throttle_conn(ssh, +1);
6869 }
51df0ab5 6870 }
6871}
6872
bc06669b 6873static void ssh_channel_destroy(struct ssh_channel *c)
51df0ab5 6874{
bc06669b 6875 Ssh ssh = c->ssh;
51df0ab5 6876
bc06669b 6877 switch (c->type) {
6878 case CHAN_MAINSESSION:
6879 ssh->mainchan = NULL;
6880 update_specials_menu(ssh->frontend);
6881 break;
6882 case CHAN_X11:
6883 if (c->u.x11.s != NULL)
6884 x11_close(c->u.x11.s);
6885 logevent("Forwarded X11 connection terminated");
6886 break;
6887 case CHAN_AGENT:
6888 sfree(c->u.a.message);
6889 break;
6890 case CHAN_SOCKDATA:
6891 if (c->u.pfd.s != NULL)
6892 pfd_close(c->u.pfd.s);
6893 logevent("Forwarded port closed");
6894 break;
6895 }
6896
6897 del234(ssh->channels, c);
6898 if (ssh->version == 2)
6899 bufchain_clear(&c->v.v2.outbuffer);
6900 sfree(c);
6901
6902 /*
6903 * See if that was the last channel left open.
6904 * (This is only our termination condition if we're
6905 * not running in -N mode.)
6906 */
6907 if (ssh->version == 2 &&
6908 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
6909 count234(ssh->channels) == 0) {
6910 /*
6911 * We used to send SSH_MSG_DISCONNECT here,
6912 * because I'd believed that _every_ conforming
6913 * SSH-2 connection had to end with a disconnect
6914 * being sent by at least one side; apparently
6915 * I was wrong and it's perfectly OK to
6916 * unceremoniously slam the connection shut
6917 * when you're done, and indeed OpenSSH feels
6918 * this is more polite than sending a
6919 * DISCONNECT. So now we don't.
6920 */
6921 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6922 }
6923}
6924
6925static void ssh2_channel_check_close(struct ssh_channel *c)
6926{
6927 Ssh ssh = c->ssh;
6928 struct Packet *pktout;
6929
6930 if ((c->closes & (CLOSES_SENT_EOF | CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
997097db 6931 == (CLOSES_SENT_EOF | CLOSES_RCVD_EOF) && !c->v.v2.winadj_head) {
bc06669b 6932 /*
997097db 6933 * We have both sent and received EOF, and we have no
6934 * outstanding winadj channel requests, which means the
6935 * channel is in final wind-up. But we haven't sent CLOSE, so
6936 * let's do so now.
bc06669b 6937 */
6938 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6939 ssh2_pkt_adduint32(pktout, c->remoteid);
6940 ssh2_pkt_send(ssh, pktout);
6941 c->closes |= CLOSES_SENT_CLOSE;
6942 }
6943
6944 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
6945 /*
6946 * We have both sent and received CLOSE, which means we're
6947 * completely done with the channel.
6948 */
6949 ssh_channel_destroy(c);
6950 }
6951}
6952
6953static void ssh2_channel_got_eof(struct ssh_channel *c)
6954{
6955 if (c->closes & CLOSES_RCVD_EOF)
6956 return; /* already seen EOF */
6957 c->closes |= CLOSES_RCVD_EOF;
51df0ab5 6958
6959 if (c->type == CHAN_X11) {
bc06669b 6960 x11_send_eof(c->u.x11.s);
51df0ab5 6961 } else if (c->type == CHAN_AGENT) {
bc06669b 6962 /* Manufacture an outgoing EOF in response to the incoming one. */
6963 sshfwd_write_eof(c);
51df0ab5 6964 } else if (c->type == CHAN_SOCKDATA) {
bc06669b 6965 pfd_send_eof(c->u.pfd.s);
6966 } else if (c->type == CHAN_MAINSESSION) {
6967 Ssh ssh = c->ssh;
6968
4a202fc6 6969 if (!ssh->sent_console_eof &&
6970 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
bc06669b 6971 /*
4a202fc6 6972 * Either from_backend_eof told us that the front end
6973 * wants us to close the outgoing side of the connection
6974 * as soon as we see EOF from the far end, or else we've
6975 * unilaterally decided to do that because we've allocated
6976 * a remote pty and hence EOF isn't a particularly
6977 * meaningful concept.
bc06669b 6978 */
6979 sshfwd_write_eof(c);
6980 }
6981 ssh->sent_console_eof = TRUE;
51df0ab5 6982 }
bc06669b 6983
6984 ssh2_channel_check_close(c);
6985}
6986
6987static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6988{
6989 struct ssh_channel *c;
6990
6991 c = ssh2_channel_msg(ssh, pktin);
6992 if (!c)
6993 return;
6994 ssh2_channel_got_eof(c);
51df0ab5 6995}
6996
6997static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6998{
51df0ab5 6999 struct ssh_channel *c;
51df0ab5 7000
e223b7c7 7001 c = ssh2_channel_msg(ssh, pktin);
7002 if (!c)
51df0ab5 7003 return;
51df0ab5 7004
7005 /*
bc06669b 7006 * When we receive CLOSE on a channel, we assume it comes with an
7007 * implied EOF if we haven't seen EOF yet.
51df0ab5 7008 */
bc06669b 7009 ssh2_channel_got_eof(c);
7010
7011 /*
3effbcf2 7012 * And we also send an outgoing EOF, if we haven't already, on the
7013 * assumption that CLOSE is a pretty forceful announcement that
7014 * the remote side is doing away with the entire channel. (If it
7015 * had wanted to send us EOF and continue receiving data from us,
7016 * it would have just sent CHANNEL_EOF.)
3effbcf2 7017 */
a699eb41 7018 if (!(c->closes & CLOSES_SENT_EOF)) {
7019 /*
7020 * Make sure we don't read any more from whatever our local
7021 * data source is for this channel.
7022 */
7023 switch (c->type) {
7024 case CHAN_MAINSESSION:
7025 ssh->send_ok = 0; /* stop trying to read from stdin */
7026 break;
7027 case CHAN_X11:
7028 x11_override_throttle(c->u.x11.s, 1);
7029 break;
7030 case CHAN_SOCKDATA:
7031 pfd_override_throttle(c->u.pfd.s, 1);
7032 break;
7033 }
7034
7035 /*
7036 * Send outgoing EOF.
7037 */
7539afa2 7038 sshfwd_write_eof(c);
3effbcf2 7039 }
7040
7041 /*
bc06669b 7042 * Now process the actual close.
7043 */
7044 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7045 c->closes |= CLOSES_RCVD_CLOSE;
7046 ssh2_channel_check_close(c);
51df0ab5 7047 }
7048}
7049
7050static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7051{
51df0ab5 7052 struct ssh_channel *c;
51df0ab5 7053
e223b7c7 7054 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7055 if (!c)
e223b7c7 7056 return;
51df0ab5 7057 if (c->type != CHAN_SOCKDATA_DORMANT)
7058 return; /* dunno why they're confirming this */
7059 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 7060 c->halfopen = FALSE;
51df0ab5 7061 c->type = CHAN_SOCKDATA;
7062 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7063 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7064 if (c->u.pfd.s)
7065 pfd_confirm(c->u.pfd.s);
bc06669b 7066 if (c->pending_eof)
7067 ssh_channel_try_eof(c);
51df0ab5 7068}
7069
7070static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7071{
7072 static const char *const reasons[] = {
7073 "<unknown reason code>",
7074 "Administratively prohibited",
7075 "Connect failed",
7076 "Unknown channel type",
7077 "Resource shortage",
7078 };
51df0ab5 7079 unsigned reason_code;
7080 char *reason_string;
7081 int reason_length;
51df0ab5 7082 struct ssh_channel *c;
e223b7c7 7083 c = ssh2_channel_msg(ssh, pktin);
51df0ab5 7084 if (!c)
e223b7c7 7085 return;
51df0ab5 7086 if (c->type != CHAN_SOCKDATA_DORMANT)
7087 return; /* dunno why they're failing this */
7088
7089 reason_code = ssh_pkt_getuint32(pktin);
7090 if (reason_code >= lenof(reasons))
7091 reason_code = 0; /* ensure reasons[reason_code] in range */
7092 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 7093 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7094 reasons[reason_code], reason_length, reason_string);
51df0ab5 7095
7096 pfd_close(c->u.pfd.s);
7097
7098 del234(ssh->channels, c);
7099 sfree(c);
7100}
7101
7102static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7103{
51df0ab5 7104 char *type;
7105 int typelen, want_reply;
7106 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7107 struct ssh_channel *c;
7108 struct Packet *pktout;
7109
e223b7c7 7110 c = ssh2_channel_msg(ssh, pktin);
7111 if (!c)
7112 return;
51df0ab5 7113 ssh_pkt_getstring(pktin, &type, &typelen);
7114 want_reply = ssh2_pkt_getbool(pktin);
7115
7116 /*
51df0ab5 7117 * Having got the channel number, we now look at
7118 * the request type string to see if it's something
7119 * we recognise.
7120 */
7121 if (c == ssh->mainchan) {
7122 /*
7123 * We recognise "exit-status" and "exit-signal" on
7124 * the primary channel.
7125 */
7126 if (typelen == 11 &&
7127 !memcmp(type, "exit-status", 11)) {
7128
7129 ssh->exitcode = ssh_pkt_getuint32(pktin);
7130 logeventf(ssh, "Server sent command exit status %d",
7131 ssh->exitcode);
7132 reply = SSH2_MSG_CHANNEL_SUCCESS;
7133
7134 } else if (typelen == 11 &&
7135 !memcmp(type, "exit-signal", 11)) {
7136
7137 int is_plausible = TRUE, is_int = FALSE;
7138 char *fmt_sig = "", *fmt_msg = "";
7139 char *msg;
7140 int msglen = 0, core = FALSE;
7141 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7142 * provide an `int' for the signal, despite its
bccbeb71 7143 * having been a `string' in the drafts of RFC 4254 since at
51df0ab5 7144 * least 2001. (Fixed in session.c 1.147.) Try to
7145 * infer which we can safely parse it as. */
7146 {
7147 unsigned char *p = pktin->body +
7148 pktin->savedpos;
7149 long len = pktin->length - pktin->savedpos;
7150 unsigned long num = GET_32BIT(p); /* what is it? */
7151 /* If it's 0, it hardly matters; assume string */
7152 if (num == 0) {
7153 is_int = FALSE;
7154 } else {
7155 int maybe_int = FALSE, maybe_str = FALSE;
7156#define CHECK_HYPOTHESIS(offset, result) \
7157 do { \
7158 long q = offset; \
7159 if (q >= 0 && q+4 <= len) { \
7160 q = q + 4 + GET_32BIT(p+q); \
7161 if (q >= 0 && q+4 <= len && \
c849ff23 7162 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
51df0ab5 7163 result = TRUE; \
7164 } \
7165 } while(0)
7166 CHECK_HYPOTHESIS(4+1, maybe_int);
7167 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7168#undef CHECK_HYPOTHESIS
7169 if (maybe_int && !maybe_str)
7170 is_int = TRUE;
7171 else if (!maybe_int && maybe_str)
7172 is_int = FALSE;
7173 else
7174 /* Crikey. Either or neither. Panic. */
7175 is_plausible = FALSE;
7176 }
7177 }
d051d1b4 7178 ssh->exitcode = 128; /* means `unknown signal' */
51df0ab5 7179 if (is_plausible) {
7180 if (is_int) {
7181 /* Old non-standard OpenSSH. */
7182 int signum = ssh_pkt_getuint32(pktin);
7183 fmt_sig = dupprintf(" %d", signum);
d051d1b4 7184 ssh->exitcode = 128 + signum;
51df0ab5 7185 } else {
bccbeb71 7186 /* As per RFC 4254. */
51df0ab5 7187 char *sig;
7188 int siglen;
7189 ssh_pkt_getstring(pktin, &sig, &siglen);
7190 /* Signal name isn't supposed to be blank, but
7191 * let's cope gracefully if it is. */
7192 if (siglen) {
7193 fmt_sig = dupprintf(" \"%.*s\"",
7194 siglen, sig);
7195 }
d051d1b4 7196
7197 /*
7198 * Really hideous method of translating the
7199 * signal description back into a locally
7200 * meaningful number.
7201 */
7202
7203 if (0)
7204 ;
b707973a 7205#define TRANSLATE_SIGNAL(s) \
7206 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7207 ssh->exitcode = 128 + SIG ## s
d051d1b4 7208#ifdef SIGABRT
b707973a 7209 TRANSLATE_SIGNAL(ABRT);
d051d1b4 7210#endif
7211#ifdef SIGALRM
b707973a 7212 TRANSLATE_SIGNAL(ALRM);
d051d1b4 7213#endif
7214#ifdef SIGFPE
b707973a 7215 TRANSLATE_SIGNAL(FPE);
d051d1b4 7216#endif
7217#ifdef SIGHUP
b707973a 7218 TRANSLATE_SIGNAL(HUP);
d051d1b4 7219#endif
7220#ifdef SIGILL
b707973a 7221 TRANSLATE_SIGNAL(ILL);
d051d1b4 7222#endif
7223#ifdef SIGINT
b707973a 7224 TRANSLATE_SIGNAL(INT);
d051d1b4 7225#endif
7226#ifdef SIGKILL
b707973a 7227 TRANSLATE_SIGNAL(KILL);
d051d1b4 7228#endif
7229#ifdef SIGPIPE
b707973a 7230 TRANSLATE_SIGNAL(PIPE);
d051d1b4 7231#endif
7232#ifdef SIGQUIT
b707973a 7233 TRANSLATE_SIGNAL(QUIT);
d051d1b4 7234#endif
7235#ifdef SIGSEGV
b707973a 7236 TRANSLATE_SIGNAL(SEGV);
d051d1b4 7237#endif
7238#ifdef SIGTERM
b707973a 7239 TRANSLATE_SIGNAL(TERM);
d051d1b4 7240#endif
7241#ifdef SIGUSR1
b707973a 7242 TRANSLATE_SIGNAL(USR1);
d051d1b4 7243#endif
7244#ifdef SIGUSR2
b707973a 7245 TRANSLATE_SIGNAL(USR2);
d051d1b4 7246#endif
b707973a 7247#undef TRANSLATE_SIGNAL
d051d1b4 7248 else
7249 ssh->exitcode = 128;
51df0ab5 7250 }
7251 core = ssh2_pkt_getbool(pktin);
7252 ssh_pkt_getstring(pktin, &msg, &msglen);
7253 if (msglen) {
7254 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7255 }
7256 /* ignore lang tag */
7257 } /* else don't attempt to parse */
7258 logeventf(ssh, "Server exited on signal%s%s%s",
7259 fmt_sig, core ? " (core dumped)" : "",
7260 fmt_msg);
7261 if (*fmt_sig) sfree(fmt_sig);
7262 if (*fmt_msg) sfree(fmt_msg);
7263 reply = SSH2_MSG_CHANNEL_SUCCESS;
7264
7265 }
7266 } else {
7267 /*
7268 * This is a channel request we don't know
7269 * about, so we now either ignore the request
7270 * or respond with CHANNEL_FAILURE, depending
7271 * on want_reply.
7272 */
7273 reply = SSH2_MSG_CHANNEL_FAILURE;
7274 }
7275 if (want_reply) {
7276 pktout = ssh2_pkt_init(reply);
7277 ssh2_pkt_adduint32(pktout, c->remoteid);
7278 ssh2_pkt_send(ssh, pktout);
7279 }
7280}
7281
7282static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7283{
7284 char *type;
7285 int typelen, want_reply;
7286 struct Packet *pktout;
7287
7288 ssh_pkt_getstring(pktin, &type, &typelen);
7289 want_reply = ssh2_pkt_getbool(pktin);
7290
7291 /*
7292 * We currently don't support any global requests
7293 * at all, so we either ignore the request or
7294 * respond with REQUEST_FAILURE, depending on
7295 * want_reply.
7296 */
7297 if (want_reply) {
7298 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7299 ssh2_pkt_send(ssh, pktout);
7300 }
7301}
7302
7303static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7304{
7305 char *type;
7306 int typelen;
7307 char *peeraddr;
7308 int peeraddrlen;
7309 int peerport;
7310 char *error = NULL;
7311 struct ssh_channel *c;
7312 unsigned remid, winsize, pktsize;
7313 struct Packet *pktout;
7314
7315 ssh_pkt_getstring(pktin, &type, &typelen);
7316 c = snew(struct ssh_channel);
7317 c->ssh = ssh;
7318
7319 remid = ssh_pkt_getuint32(pktin);
7320 winsize = ssh_pkt_getuint32(pktin);
7321 pktsize = ssh_pkt_getuint32(pktin);
7322
7323 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7324 char *addrstr;
5907ebda 7325 const char *x11err;
51df0ab5 7326
7327 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7328 addrstr = snewn(peeraddrlen+1, char);
7329 memcpy(addrstr, peeraddr, peeraddrlen);
7330 addrstr[peeraddrlen] = '\0';
7331 peerport = ssh_pkt_getuint32(pktin);
7332
7333 logeventf(ssh, "Received X11 connect request from %s:%d",
7334 addrstr, peerport);
7335
7336 if (!ssh->X11_fwd_enabled)
7337 error = "X11 forwarding is not enabled";
5907ebda 7338 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
4a693cfc 7339 addrstr, peerport, ssh->conf)) != NULL) {
5907ebda 7340 logeventf(ssh, "Local X11 connection failed: %s", x11err);
51df0ab5 7341 error = "Unable to open an X11 connection";
7342 } else {
7343 logevent("Opening X11 forward connection succeeded");
7344 c->type = CHAN_X11;
7345 }
7346
7347 sfree(addrstr);
7348 } else if (typelen == 15 &&
7349 !memcmp(type, "forwarded-tcpip", 15)) {
7350 struct ssh_rportfwd pf, *realpf;
7351 char *dummy;
7352 int dummylen;
7353 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7354 pf.sport = ssh_pkt_getuint32(pktin);
7355 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7356 peerport = ssh_pkt_getuint32(pktin);
7357 realpf = find234(ssh->rportfwds, &pf, NULL);
7358 logeventf(ssh, "Received remote port %d open request "
7359 "from %s:%d", pf.sport, peeraddr, peerport);
7360 if (realpf == NULL) {
7361 error = "Remote port is not recognised";
7362 } else {
7363 const char *e = pfd_newconnect(&c->u.pfd.s,
7364 realpf->dhost,
7365 realpf->dport, c,
4a693cfc 7366 ssh->conf,
05581745 7367 realpf->pfrec->addressfamily);
51df0ab5 7368 logeventf(ssh, "Attempting to forward remote port to "
7369 "%s:%d", realpf->dhost, realpf->dport);
7370 if (e != NULL) {
7371 logeventf(ssh, "Port open failed: %s", e);
7372 error = "Port open failed";
7373 } else {
7374 logevent("Forwarded port opened successfully");
7375 c->type = CHAN_SOCKDATA;
7376 }
7377 }
7378 } else if (typelen == 22 &&
c49cf994 7379 !memcmp(type, "auth-agent@openssh.com", 22)) {
51df0ab5 7380 if (!ssh->agentfwd_enabled)
7381 error = "Agent forwarding is not enabled";
7382 else {
7383 c->type = CHAN_AGENT; /* identify channel type */
7384 c->u.a.lensofar = 0;
7385 }
7386 } else {
7387 error = "Unsupported channel type requested";
7388 }
7389
7390 c->remoteid = remid;
64d6ff88 7391 c->halfopen = FALSE;
51df0ab5 7392 if (error) {
7393 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7394 ssh2_pkt_adduint32(pktout, c->remoteid);
7395 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7396 ssh2_pkt_addstring(pktout, error);
7397 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7398 ssh2_pkt_send(ssh, pktout);
7399 logeventf(ssh, "Rejected channel open: %s", error);
7400 sfree(c);
7401 } else {
94bdfe40 7402 ssh2_channel_init(c);
51df0ab5 7403 c->v.v2.remwindow = winsize;
7404 c->v.v2.remmaxpkt = pktsize;
51df0ab5 7405 add234(ssh->channels, c);
7406 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7407 ssh2_pkt_adduint32(pktout, c->remoteid);
7408 ssh2_pkt_adduint32(pktout, c->localid);
7409 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 7410 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 7411 ssh2_pkt_send(ssh, pktout);
7412 }
7413}
7414
6bbce591 7415/*
adb6167a 7416 * Buffer banner messages for later display at some convenient point,
7417 * if we're going to display them.
6bbce591 7418 */
7419static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7420{
7421 /* Arbitrary limit to prevent unbounded inflation of buffer */
4a693cfc 7422 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
adb6167a 7423 bufchain_size(&ssh->banner) <= 131072) {
6bbce591 7424 char *banner = NULL;
7425 int size = 0;
7426 ssh_pkt_getstring(pktin, &banner, &size);
7427 if (banner)
7428 bufchain_add(&ssh->banner, banner, size);
7429 }
7430}
7431
c6ccd5c2 7432/* Helper function to deal with sending tty modes for "pty-req" */
7433static void ssh2_send_ttymode(void *data, char *mode, char *val)
7434{
7435 struct Packet *pktout = (struct Packet *)data;
7436 int i = 0;
7437 unsigned int arg = 0;
7438 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7439 if (i == lenof(ssh_ttymodes)) return;
7440 switch (ssh_ttymodes[i].type) {
7441 case TTY_OP_CHAR:
7442 arg = ssh_tty_parse_specchar(val);
7443 break;
7444 case TTY_OP_BOOL:
7445 arg = ssh_tty_parse_boolean(val);
7446 break;
7447 }
7448 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7449 ssh2_pkt_adduint32(pktout, arg);
7450}
7451
783415f8 7452/*
2e85c969 7453 * Handle the SSH-2 userauth and connection layers.
7cca0d81 7454 */
ff3187f6 7455static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7456 struct Packet *pktin)
7cca0d81 7457{
51470298 7458 struct do_ssh2_authconn_state {
7459 enum {
51470298 7460 AUTH_TYPE_NONE,
7461 AUTH_TYPE_PUBLICKEY,
7462 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7463 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7464 AUTH_TYPE_PASSWORD,
8221906d 7465 AUTH_TYPE_GSSAPI, /* always QUIET */
51470298 7466 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7467 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7468 } type;
a1a1fae4 7469 int done_service_req;
51470298 7470 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
94cd7c3a 7471 int tried_pubkey_config, done_agent;
bf84a03a 7472#ifndef NO_GSSAPI
42af6a67 7473 int can_gssapi;
7474 int tried_gssapi;
bf84a03a 7475#endif
edd0cb8a 7476 int kbd_inter_refused;
ab18ccff 7477 int we_are_in, userauth_success;
edd0cb8a 7478 prompts_t *cur_prompt;
7479 int num_prompts;
4a693cfc 7480 char *username;
e955d348 7481 char *password;
51470298 7482 int got_username;
51470298 7483 void *publickey_blob;
7484 int publickey_bloblen;
edd0cb8a 7485 int publickey_encrypted;
7486 char *publickey_algorithm;
7487 char *publickey_comment;
94cd7c3a 7488 unsigned char agent_request[5], *agent_response, *agentp;
7489 int agent_responselen;
7490 unsigned char *pkblob_in_agent;
51470298 7491 int keyi, nkeys;
51470298 7492 char *pkblob, *alg, *commentp;
7493 int pklen, alglen, commentlen;
7494 int siglen, retlen, len;
7495 char *q, *agentreq, *ret;
7496 int try_send;
73feed4f 7497 int num_env, env_left, env_ok;
ff3187f6 7498 struct Packet *pktout;
4a693cfc 7499 Filename *keyfile;
bf84a03a 7500#ifndef NO_GSSAPI
b3d375b2 7501 struct ssh_gss_library *gsslib;
42af6a67 7502 Ssh_gss_ctx gss_ctx;
7503 Ssh_gss_buf gss_buf;
7504 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7505 Ssh_gss_name gss_srv_name;
7506 Ssh_gss_stat gss_stat;
bf84a03a 7507#endif
51470298 7508 };
7509 crState(do_ssh2_authconn_state);
7510
7511 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 7512
a1a1fae4 7513 s->done_service_req = FALSE;
ab18ccff 7514 s->we_are_in = s->userauth_success = FALSE;
bf84a03a 7515#ifndef NO_GSSAPI
42af6a67 7516 s->tried_gssapi = FALSE;
bf84a03a 7517#endif
42af6a67 7518
4a693cfc 7519 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
a1a1fae4 7520 /*
7521 * Request userauth protocol, and await a response to it.
7522 */
7523 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7524 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7525 ssh2_pkt_send(ssh, s->pktout);
7526 crWaitUntilV(pktin);
7527 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7528 s->done_service_req = TRUE;
7529 }
7530 if (!s->done_service_req) {
7531 /*
7532 * Request connection protocol directly, without authentication.
7533 */
7534 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7535 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7536 ssh2_pkt_send(ssh, s->pktout);
7537 crWaitUntilV(pktin);
7538 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7539 s->we_are_in = TRUE; /* no auth required */
7540 } else {
7541 bombout(("Server refused service request"));
7542 crStopV;
7543 }
8d5de777 7544 }
7cca0d81 7545
94cd7c3a 7546 /* Arrange to be able to deal with any BANNERs that come in.
7547 * (We do this now as packets may come in during the next bit.) */
7548 bufchain_init(&ssh->banner);
7549 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7550 ssh2_msg_userauth_banner;
7551
7cca0d81 7552 /*
edd0cb8a 7553 * Misc one-time setup for authentication.
7554 */
7555 s->publickey_blob = NULL;
7556 if (!s->we_are_in) {
7557
7558 /*
7559 * Load the public half of any configured public key file
7560 * for later use.
7561 */
4a693cfc 7562 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
962468d4 7563 if (!filename_is_null(s->keyfile)) {
edd0cb8a 7564 int keytype;
7565 logeventf(ssh, "Reading private key file \"%.150s\"",
4a693cfc 7566 filename_to_str(s->keyfile));
7567 keytype = key_type(s->keyfile);
edd0cb8a 7568 if (keytype == SSH_KEYTYPE_SSH2) {
7569 const char *error;
7570 s->publickey_blob =
4a693cfc 7571 ssh2_userkey_loadpub(s->keyfile,
edd0cb8a 7572 &s->publickey_algorithm,
7573 &s->publickey_bloblen,
7574 &s->publickey_comment, &error);
7575 if (s->publickey_blob) {
7576 s->publickey_encrypted =
4a693cfc 7577 ssh2_userkey_encrypted(s->keyfile, NULL);
edd0cb8a 7578 } else {
7579 char *msgbuf;
7580 logeventf(ssh, "Unable to load private key (%s)",
7581 error);
7582 msgbuf = dupprintf("Unable to load private key file "
7583 "\"%.150s\" (%s)\r\n",
4a693cfc 7584 filename_to_str(s->keyfile),
edd0cb8a 7585 error);
7586 c_write_str(ssh, msgbuf);
7587 sfree(msgbuf);
7588 }
7589 } else {
7590 char *msgbuf;
7591 logeventf(ssh, "Unable to use this key file (%s)",
7592 key_type_to_str(keytype));
7593 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7594 " (%s)\r\n",
4a693cfc 7595 filename_to_str(s->keyfile),
edd0cb8a 7596 key_type_to_str(keytype));
7597 c_write_str(ssh, msgbuf);
7598 sfree(msgbuf);
7599 s->publickey_blob = NULL;
7600 }
7601 }
7602
94cd7c3a 7603 /*
7604 * Find out about any keys Pageant has (but if there's a
7605 * public key configured, filter out all others).
7606 */
7607 s->nkeys = 0;
7608 s->agent_response = NULL;
7609 s->pkblob_in_agent = NULL;
4a693cfc 7610 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
94cd7c3a 7611
7612 void *r;
7613
7614 logevent("Pageant is running. Requesting keys.");
7615
7616 /* Request the keys held by the agent. */
7617 PUT_32BIT(s->agent_request, 1);
7618 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7619 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7620 ssh_agent_callback, ssh)) {
7621 do {
7622 crReturnV;
7623 if (pktin) {
7624 bombout(("Unexpected data from server while"
7625 " waiting for agent response"));
7626 crStopV;
7627 }
7628 } while (pktin || inlen > 0);
7629 r = ssh->agent_response;
7630 s->agent_responselen = ssh->agent_response_len;
7631 }
7632 s->agent_response = (unsigned char *) r;
7633 if (s->agent_response && s->agent_responselen >= 5 &&
7634 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7635 int keyi;
7636 unsigned char *p;
7637 p = s->agent_response + 5;
7638 s->nkeys = GET_32BIT(p);
7639 p += 4;
7640 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
7641 if (s->publickey_blob) {
7642 /* See if configured key is in agent. */
7643 for (keyi = 0; keyi < s->nkeys; keyi++) {
7644 s->pklen = GET_32BIT(p);
7645 if (s->pklen == s->publickey_bloblen &&
7646 !memcmp(p+4, s->publickey_blob,
7647 s->publickey_bloblen)) {
7648 logeventf(ssh, "Pageant key #%d matches "
7649 "configured key file", keyi);
7650 s->keyi = keyi;
7651 s->pkblob_in_agent = p;
7652 break;
7653 }
7654 p += 4 + s->pklen;
7655 p += GET_32BIT(p) + 4; /* comment */
7656 }
7657 if (!s->pkblob_in_agent) {
7658 logevent("Configured key file not in Pageant");
7659 s->nkeys = 0;
7660 }
7661 }
5ff99b8e 7662 } else {
7663 logevent("Failed to get reply from Pageant");
94cd7c3a 7664 }
7665 }
7666
edd0cb8a 7667 }
7668
7669 /*
1408a877 7670 * We repeat this whole loop, including the username prompt,
7671 * until we manage a successful authentication. If the user
51470298 7672 * types the wrong _password_, they can be sent back to the
7673 * beginning to try another username, if this is configured on.
7674 * (If they specify a username in the config, they are never
7675 * asked, even if they do give a wrong password.)
1408a877 7676 *
7677 * I think this best serves the needs of
7678 *
7679 * - the people who have no configuration, no keys, and just
7680 * want to try repeated (username,password) pairs until they
7681 * type both correctly
7682 *
7683 * - people who have keys and configuration but occasionally
7684 * need to fall back to passwords
7685 *
7686 * - people with a key held in Pageant, who might not have
7687 * logged in to a particular machine before; so they want to
7688 * type a username, and then _either_ their key will be
7689 * accepted, _or_ they will type a password. If they mistype
7690 * the username they will want to be able to get back and
7691 * retype it!
7cca0d81 7692 */
51470298 7693 s->got_username = FALSE;
a1a1fae4 7694 while (!s->we_are_in) {
1408a877 7695 /*
7696 * Get a username.
7697 */
4a693cfc 7698 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
5bb641e1 7699 /*
7700 * We got a username last time round this loop, and
7701 * with change_username turned off we don't try to get
7702 * it again.
7703 */
4a693cfc 7704 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
edd0cb8a 7705 int ret; /* need not be kept over crReturn */
7706 s->cur_prompt = new_prompts(ssh->frontend);
7707 s->cur_prompt->to_server = TRUE;
7708 s->cur_prompt->name = dupstr("SSH login name");
b61f81bc 7709 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
edd0cb8a 7710 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7711 while (ret < 0) {
51470298 7712 ssh->send_ok = 1;
edd0cb8a 7713 crWaitUntilV(!pktin);
7714 ret = get_userpass_input(s->cur_prompt, in, inlen);
7715 ssh->send_ok = 0;
32874aea 7716 }
edd0cb8a 7717 if (!ret) {
7718 /*
7719 * get_userpass_input() failed to get a username.
7720 * Terminate.
7721 */
7722 free_prompts(s->cur_prompt);
7723 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7724 crStopV;
7725 }
4a693cfc 7726 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
edd0cb8a 7727 free_prompts(s->cur_prompt);
7cca0d81 7728 } else {
57356d63 7729 char *stuff;
65a22376 7730 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4a693cfc 7731 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
51470298 7732 c_write_str(ssh, stuff);
57356d63 7733 sfree(stuff);
7cca0d81 7734 }
7735 }
51470298 7736 s->got_username = TRUE;
7cca0d81 7737
65a22376 7738 /*
1408a877 7739 * Send an authentication request using method "none": (a)
7740 * just in case it succeeds, and (b) so that we know what
7741 * authentication methods we can usefully try next.
65a22376 7742 */
acab36bc 7743 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
51470298 7744
ff3187f6 7745 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7746 ssh2_pkt_addstring(s->pktout, ssh->username);
ff3187f6 7747 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7748 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7749 ssh2_pkt_send(ssh, s->pktout);
51470298 7750 s->type = AUTH_TYPE_NONE;
7751 s->gotit = FALSE;
7752 s->we_are_in = FALSE;
7753
7754 s->tried_pubkey_config = FALSE;
6ac3a551 7755 s->kbd_inter_refused = FALSE;
65a22376 7756
94cd7c3a 7757 /* Reset agent request state. */
7758 s->done_agent = FALSE;
7759 if (s->agent_response) {
7760 if (s->pkblob_in_agent) {
7761 s->agentp = s->pkblob_in_agent;
7762 } else {
7763 s->agentp = s->agent_response + 5 + 4;
7764 s->keyi = 0;
7765 }
7766 }
7767
1408a877 7768 while (1) {
854caca5 7769 char *methods = NULL;
7770 int methlen = 0;
7771
1408a877 7772 /*
7773 * Wait for the result of the last authentication request.
7774 */
51470298 7775 if (!s->gotit)
ff3187f6 7776 crWaitUntilV(pktin);
6bbce591 7777 /*
7778 * Now is a convenient point to spew any banner material
7779 * that we've accumulated. (This should ensure that when
7780 * we exit the auth loop, we haven't any left to deal
7781 * with.)
7782 */
7783 {
7784 int size = bufchain_size(&ssh->banner);
32874aea 7785 /*
7786 * Don't show the banner if we're operating in
7787 * non-verbose non-interactive mode. (It's probably
7788 * a script, which means nobody will read the
7789 * banner _anyway_, and moreover the printing of
7790 * the banner will screw up processing on the
7791 * output of (say) plink.)
7792 */
6bbce591 7793 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7794 char *banner = snewn(size, char);
7795 bufchain_fetch(&ssh->banner, banner, size);
7796 c_write_untrusted(ssh, banner, size);
7797 sfree(banner);
32874aea 7798 }
6bbce591 7799 bufchain_clear(&ssh->banner);
1408a877 7800 }
ff3187f6 7801 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 7802 logevent("Access granted");
ab18ccff 7803 s->we_are_in = s->userauth_success = TRUE;
1408a877 7804 break;
7805 }
65a22376 7806
42af6a67 7807 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
e955d348 7808 bombout(("Strange packet received during authentication: "
7809 "type %d", pktin->type));
7ffdbc1a 7810 crStopV;
65a22376 7811 }
7812
51470298 7813 s->gotit = FALSE;
65a22376 7814
1408a877 7815 /*
7816 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7817 * we can look at the string in it and know what we can
7818 * helpfully try next.
7819 */
ff3187f6 7820 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
ff3187f6 7821 ssh_pkt_getstring(pktin, &methods, &methlen);
ff3187f6 7822 if (!ssh2_pkt_getbool(pktin)) {
1408a877 7823 /*
7824 * We have received an unequivocal Access
7825 * Denied. This can translate to a variety of
8221906d 7826 * messages, or no message at all.
7827 *
7828 * For forms of authentication which are attempted
7829 * implicitly, by which I mean without printing
7830 * anything in the window indicating that we're
7831 * trying them, we should never print 'Access
7832 * denied'.
7833 *
7834 * If we do print a message saying that we're
7835 * attempting some kind of authentication, it's OK
7836 * to print a followup message saying it failed -
7837 * but the message may sometimes be more specific
7838 * than simply 'Access denied'.
7839 *
1408a877 7840 * Additionally, if we'd just tried password
7841 * authentication, we should break out of this
7842 * whole loop so as to go back to the username
91f57d1f 7843 * prompt (iff we're configured to allow
7844 * username change attempts).
1408a877 7845 */
51470298 7846 if (s->type == AUTH_TYPE_NONE) {
1408a877 7847 /* do nothing */
51470298 7848 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7849 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7850 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7851 c_write_str(ssh, "Server refused our key\r\n");
8221906d 7852 logevent("Server refused our key");
7853 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
7854 /* This _shouldn't_ happen except by a
7855 * protocol bug causing client and server to
7856 * disagree on what is a correct signature. */
7857 c_write_str(ssh, "Server refused public-key signature"
7858 " despite accepting key!\r\n");
7859 logevent("Server refused public-key signature"
7860 " despite accepting key!");
51470298 7861 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8221906d 7862 /* quiet, so no c_write */
7863 logevent("Server refused keyboard-interactive authentication");
7864 } else if (s->type==AUTH_TYPE_GSSAPI) {
7865 /* always quiet, so no c_write */
2af4fe8f 7866 /* also, the code down in the GSSAPI block has
7867 * already logged this in the Event Log */
8221906d 7868 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
7869 logevent("Keyboard-interactive authentication failed");
7870 c_write_str(ssh, "Access denied\r\n");
7871 } else {
7872 assert(s->type == AUTH_TYPE_PASSWORD);
7873 logevent("Password authentication failed");
51470298 7874 c_write_str(ssh, "Access denied\r\n");
8221906d 7875
7876 if (conf_get_int(ssh->conf, CONF_change_username)) {
6c9dce7c 7877 /* XXX perhaps we should allow
7878 * keyboard-interactive to do this too? */
51470298 7879 s->we_are_in = FALSE;
1408a877 7880 break;
7881 }
7882 }
7883 } else {
51470298 7884 c_write_str(ssh, "Further authentication required\r\n");
1408a877 7885 logevent("Further authentication required");
7886 }
65a22376 7887
51470298 7888 s->can_pubkey =
32874aea 7889 in_commasep_string("publickey", methods, methlen);
51470298 7890 s->can_passwd =
32874aea 7891 in_commasep_string("password", methods, methlen);
4a693cfc 7892 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
761187b6 7893 in_commasep_string("keyboard-interactive", methods, methlen);
1e00c92b 7894#ifndef NO_GSSAPI
7895 if (!ssh->gsslibs)
4a693cfc 7896 ssh->gsslibs = ssh_gss_setup(ssh->conf);
7897 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
b3d375b2 7898 in_commasep_string("gssapi-with-mic", methods, methlen) &&
1e00c92b 7899 ssh->gsslibs->nlibraries > 0;
42af6a67 7900#endif
1408a877 7901 }
65a22376 7902
acab36bc 7903 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
65a22376 7904
94cd7c3a 7905 if (s->can_pubkey && !s->done_agent && s->nkeys) {
0405e71f 7906
1983e559 7907 /*
94cd7c3a 7908 * Attempt public-key authentication using a key from Pageant.
1983e559 7909 */
1983e559 7910
acab36bc 7911 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 7912
94cd7c3a 7913 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7914
7915 /* Unpack key from agent response */
7916 s->pklen = GET_32BIT(s->agentp);
7917 s->agentp += 4;
7918 s->pkblob = (char *)s->agentp;
7919 s->agentp += s->pklen;
7920 s->alglen = GET_32BIT(s->pkblob);
7921 s->alg = s->pkblob + 4;
7922 s->commentlen = GET_32BIT(s->agentp);
7923 s->agentp += 4;
7924 s->commentp = (char *)s->agentp;
7925 s->agentp += s->commentlen;
7926 /* s->agentp now points at next key, if any */
7927
7928 /* See if server will accept it */
7929 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7930 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 7931 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7932 /* service requested */
7933 ssh2_pkt_addstring(s->pktout, "publickey");
7934 /* method */
7935 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7936 ssh2_pkt_addstring_start(s->pktout);
7937 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7938 ssh2_pkt_addstring_start(s->pktout);
7939 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7940 ssh2_pkt_send(ssh, s->pktout);
7941 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
1983e559 7942
94cd7c3a 7943 crWaitUntilV(pktin);
7944 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 7945
94cd7c3a 7946 /* Offer of key refused. */
7947 s->gotit = TRUE;
1983e559 7948
94cd7c3a 7949 } else {
7950
7951 void *vret;
1983e559 7952
94cd7c3a 7953 if (flags & FLAG_VERBOSE) {
7954 c_write_str(ssh, "Authenticating with "
7955 "public key \"");
7956 c_write(ssh, s->commentp, s->commentlen);
7957 c_write_str(ssh, "\" from agent\r\n");
7958 }
1983e559 7959
94cd7c3a 7960 /*
7961 * Server is willing to accept the key.
7962 * Construct a SIGN_REQUEST.
7963 */
7964 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 7965 ssh2_pkt_addstring(s->pktout, ssh->username);
94cd7c3a 7966 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7967 /* service requested */
7968 ssh2_pkt_addstring(s->pktout, "publickey");
7969 /* method */
7970 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7971 ssh2_pkt_addstring_start(s->pktout);
7972 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7973 ssh2_pkt_addstring_start(s->pktout);
7974 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7975
7976 /* Ask agent for signature. */
7977 s->siglen = s->pktout->length - 5 + 4 +
7978 ssh->v2_session_id_len;
7979 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7980 s->siglen -= 4;
7981 s->len = 1; /* message type */
7982 s->len += 4 + s->pklen; /* key blob */
7983 s->len += 4 + s->siglen; /* data to sign */
7984 s->len += 4; /* flags */
7985 s->agentreq = snewn(4 + s->len, char);
7986 PUT_32BIT(s->agentreq, s->len);
7987 s->q = s->agentreq + 4;
7988 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
7989 PUT_32BIT(s->q, s->pklen);
7990 s->q += 4;
7991 memcpy(s->q, s->pkblob, s->pklen);
7992 s->q += s->pklen;
7993 PUT_32BIT(s->q, s->siglen);
7994 s->q += 4;
7995 /* Now the data to be signed... */
7996 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7997 PUT_32BIT(s->q, ssh->v2_session_id_len);
51470298 7998 s->q += 4;
94cd7c3a 7999 }
8000 memcpy(s->q, ssh->v2_session_id,
8001 ssh->v2_session_id_len);
8002 s->q += ssh->v2_session_id_len;
8003 memcpy(s->q, s->pktout->data + 5,
8004 s->pktout->length - 5);
8005 s->q += s->pktout->length - 5;
8006 /* And finally the (zero) flags word. */
8007 PUT_32BIT(s->q, 0);
8008 if (!agent_query(s->agentreq, s->len + 4,
8009 &vret, &s->retlen,
8010 ssh_agent_callback, ssh)) {
8011 do {
8012 crReturnV;
8013 if (pktin) {
8014 bombout(("Unexpected data from server"
8015 " while waiting for agent"
8016 " response"));
8017 crStopV;
1983e559 8018 }
94cd7c3a 8019 } while (pktin || inlen > 0);
8020 vret = ssh->agent_response;
8021 s->retlen = ssh->agent_response_len;
8022 }
8023 s->ret = vret;
8024 sfree(s->agentreq);
8025 if (s->ret) {
8026 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
8027 logevent("Sending Pageant's response");
8028 ssh2_add_sigblob(ssh, s->pktout,
8029 s->pkblob, s->pklen,
8030 s->ret + 9,
8031 GET_32BIT(s->ret + 5));
8032 ssh2_pkt_send(ssh, s->pktout);
8033 s->type = AUTH_TYPE_PUBLICKEY;
8034 } else {
8035 /* FIXME: less drastic response */
8036 bombout(("Pageant failed to answer challenge"));
8037 crStopV;
1983e559 8038 }
8039 }
1983e559 8040 }
94cd7c3a 8041
8042 /* Do we have any keys left to try? */
8043 if (s->pkblob_in_agent) {
8044 s->done_agent = TRUE;
8045 s->tried_pubkey_config = TRUE;
8046 } else {
8047 s->keyi++;
8048 if (s->keyi >= s->nkeys)
8049 s->done_agent = TRUE;
8050 }
1983e559 8051
edd0cb8a 8052 } else if (s->can_pubkey && s->publickey_blob &&
8053 !s->tried_pubkey_config) {
65a22376 8054
edd0cb8a 8055 struct ssh2_userkey *key; /* not live over crReturn */
8056 char *passphrase; /* not live over crReturn */
65a22376 8057
acab36bc 8058 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 8059
edd0cb8a 8060 s->tried_pubkey_config = TRUE;
8061
65a22376 8062 /*
1408a877 8063 * Try the public key supplied in the configuration.
8064 *
8065 * First, offer the public blob to see if the server is
8066 * willing to accept it.
65a22376 8067 */
ff3187f6 8068 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8069 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8070 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8071 /* service requested */
8072 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8073 ssh2_pkt_addbool(s->pktout, FALSE);
8074 /* no signature included */
8075 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8076 ssh2_pkt_addstring_start(s->pktout);
8077 ssh2_pkt_addstring_data(s->pktout,
8078 (char *)s->publickey_blob,
8079 s->publickey_bloblen);
ff3187f6 8080 ssh2_pkt_send(ssh, s->pktout);
edd0cb8a 8081 logevent("Offered public key");
ff3187f6 8082
8083 crWaitUntilV(pktin);
edd0cb8a 8084 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8085 /* Key refused. Give up. */
8086 s->gotit = TRUE; /* reconsider message next loop */
8087 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8088 continue; /* process this new message */
45068b27 8089 }
edd0cb8a 8090 logevent("Offer of public key accepted");
af659722 8091
45068b27 8092 /*
edd0cb8a 8093 * Actually attempt a serious authentication using
8094 * the key.
45068b27 8095 */
edd0cb8a 8096 if (flags & FLAG_VERBOSE) {
8097 c_write_str(ssh, "Authenticating with public key \"");
8098 c_write_str(ssh, s->publickey_comment);
8099 c_write_str(ssh, "\"\r\n");
8100 }
8101 key = NULL;
8102 while (!key) {
8103 const char *error; /* not live over crReturn */
8104 if (s->publickey_encrypted) {
8105 /*
8106 * Get a passphrase from the user.
8107 */
8108 int ret; /* need not be kept over crReturn */
8109 s->cur_prompt = new_prompts(ssh->frontend);
8110 s->cur_prompt->to_server = FALSE;
8111 s->cur_prompt->name = dupstr("SSH key passphrase");
8112 add_prompt(s->cur_prompt,
8113 dupprintf("Passphrase for key \"%.100s\": ",
8114 s->publickey_comment),
b61f81bc 8115 FALSE);
edd0cb8a 8116 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8117 while (ret < 0) {
8118 ssh->send_ok = 1;
8119 crWaitUntilV(!pktin);
8120 ret = get_userpass_input(s->cur_prompt,
8121 in, inlen);
8122 ssh->send_ok = 0;
8123 }
8124 if (!ret) {
8125 /* Failed to get a passphrase. Terminate. */
8126 free_prompts(s->cur_prompt);
8127 ssh_disconnect(ssh, NULL,
8128 "Unable to authenticate",
8129 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8130 TRUE);
8131 crStopV;
85fdbe25 8132 }
edd0cb8a 8133 passphrase =
8134 dupstr(s->cur_prompt->prompts[0]->result);
8135 free_prompts(s->cur_prompt);
45068b27 8136 } else {
edd0cb8a 8137 passphrase = NULL; /* no passphrase needed */
45068b27 8138 }
1408a877 8139
edd0cb8a 8140 /*
8141 * Try decrypting the key.
8142 */
4a693cfc 8143 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8144 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
edd0cb8a 8145 if (passphrase) {
8146 /* burn the evidence */
8147 memset(passphrase, 0, strlen(passphrase));
8148 sfree(passphrase);
8149 }
8150 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8151 if (passphrase &&
8152 (key == SSH2_WRONG_PASSPHRASE)) {
8153 c_write_str(ssh, "Wrong passphrase\r\n");
8154 key = NULL;
8155 /* and loop again */
8156 } else {
8157 c_write_str(ssh, "Unable to load private key (");
8158 c_write_str(ssh, error);
8159 c_write_str(ssh, ")\r\n");
8160 key = NULL;
8161 break; /* try something else */
8162 }
1408a877 8163 }
65a22376 8164 }
65a22376 8165
edd0cb8a 8166 if (key) {
1dd353b5 8167 unsigned char *pkblob, *sigblob, *sigdata;
8168 int pkblob_len, sigblob_len, sigdata_len;
edd0cb8a 8169 int p;
65a22376 8170
1408a877 8171 /*
8172 * We have loaded the private key and the server
8173 * has announced that it's willing to accept it.
8174 * Hallelujah. Generate a signature and send it.
8175 */
ff3187f6 8176 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8177 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8178 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8179 /* service requested */
8180 ssh2_pkt_addstring(s->pktout, "publickey");
8181 /* method */
ff3187f6 8182 ssh2_pkt_addbool(s->pktout, TRUE);
edd0cb8a 8183 /* signature follows */
ff3187f6 8184 ssh2_pkt_addstring(s->pktout, key->alg->name);
edd0cb8a 8185 pkblob = key->alg->public_blob(key->data,
8186 &pkblob_len);
ff3187f6 8187 ssh2_pkt_addstring_start(s->pktout);
edd0cb8a 8188 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8189 pkblob_len);
1408a877 8190
8191 /*
8192 * The data to be signed is:
8193 *
8194 * string session-id
8195 *
8196 * followed by everything so far placed in the
8197 * outgoing packet.
8198 */
b672f405 8199 sigdata_len = s->pktout->length - 5 + 4 +
8200 ssh->v2_session_id_len;
edd0cb8a 8201 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8202 sigdata_len -= 4;
92d60585 8203 sigdata = snewn(sigdata_len, unsigned char);
edd0cb8a 8204 p = 0;
8205 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8206 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8207 p += 4;
8208 }
b672f405 8209 memcpy(sigdata+p, ssh->v2_session_id,
8210 ssh->v2_session_id_len);
8211 p += ssh->v2_session_id_len;
ff3187f6 8212 memcpy(sigdata+p, s->pktout->data + 5,
8213 s->pktout->length - 5);
edd0cb8a 8214 p += s->pktout->length - 5;
8215 assert(p == sigdata_len);
d8baa528 8216 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 8217 sigdata_len, &sigblob_len);
ff3187f6 8218 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 8219 sigblob, sigblob_len);
8220 sfree(pkblob);
8221 sfree(sigblob);
1408a877 8222 sfree(sigdata);
8223
ff3187f6 8224 ssh2_pkt_send(ssh, s->pktout);
8221906d 8225 logevent("Sent public key signature");
51470298 8226 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 8227 key->alg->freekey(key->data);
1408a877 8228 }
edd0cb8a 8229
42af6a67 8230#ifndef NO_GSSAPI
8231 } else if (s->can_gssapi && !s->tried_gssapi) {
8232
8233 /* GSSAPI Authentication */
8234
86557057 8235 int micoffset, len;
8236 char *data;
42af6a67 8237 Ssh_gss_buf mic;
8238 s->type = AUTH_TYPE_GSSAPI;
8239 s->tried_gssapi = TRUE;
8240 s->gotit = TRUE;
8241 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8242
b3d375b2 8243 /*
8244 * Pick the highest GSS library on the preference
8245 * list.
8246 */
8247 {
8248 int i, j;
8249 s->gsslib = NULL;
8250 for (i = 0; i < ngsslibs; i++) {
4a693cfc 8251 int want_id = conf_get_int_int(ssh->conf,
8252 CONF_ssh_gsslist, i);
1e00c92b 8253 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8254 if (ssh->gsslibs->libraries[j].id == want_id) {
8255 s->gsslib = &ssh->gsslibs->libraries[j];
b3d375b2 8256 goto got_gsslib; /* double break */
8257 }
8258 }
8259 got_gsslib:
8260 /*
8261 * We always expect to have found something in
8262 * the above loop: we only came here if there
8263 * was at least one viable GSS library, and the
8264 * preference list should always mention
8265 * everything and only change the order.
8266 */
8267 assert(s->gsslib);
8268 }
8269
8270 if (s->gsslib->gsslogmsg)
8271 logevent(s->gsslib->gsslogmsg);
8272
42af6a67 8273 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8274 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8275 ssh2_pkt_addstring(s->pktout, ssh->username);
42af6a67 8276 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8277 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8221906d 8278 logevent("Attempting GSSAPI authentication");
42af6a67 8279
8280 /* add mechanism info */
b3d375b2 8281 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
42af6a67 8282
8283 /* number of GSSAPI mechanisms */
8284 ssh2_pkt_adduint32(s->pktout,1);
8285
8286 /* length of OID + 2 */
86557057 8287 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
42af6a67 8288 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8289
8290 /* length of OID */
86557057 8291 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
42af6a67 8292
86557057 8293 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8294 s->gss_buf.length);
42af6a67 8295 ssh2_pkt_send(ssh, s->pktout);
8296 crWaitUntilV(pktin);
8297 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8298 logevent("GSSAPI authentication request refused");
8299 continue;
8300 }
8301
8302 /* check returned packet ... */
8303
86557057 8304 ssh_pkt_getstring(pktin, &data, &len);
8305 s->gss_rcvtok.value = data;
8306 s->gss_rcvtok.length = len;
8307 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8308 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8309 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8310 memcmp((char *)s->gss_rcvtok.value + 2,
8311 s->gss_buf.value,s->gss_buf.length) ) {
42af6a67 8312 logevent("GSSAPI authentication - wrong response from server");
8313 continue;
8314 }
8315
8316 /* now start running */
b3d375b2 8317 s->gss_stat = s->gsslib->import_name(s->gsslib,
8318 ssh->fullhostname,
8319 &s->gss_srv_name);
42af6a67 8320 if (s->gss_stat != SSH_GSS_OK) {
8321 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8322 logevent("GSSAPI import name failed - Bad service name");
8323 else
8324 logevent("GSSAPI import name failed");
8325 continue;
8326 }
8327
8328 /* fetch TGT into GSS engine */
b3d375b2 8329 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
42af6a67 8330
8331 if (s->gss_stat != SSH_GSS_OK) {
8332 logevent("GSSAPI authentication failed to get credentials");
b3d375b2 8333 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
42af6a67 8334 continue;
8335 }
8336
8337 /* initial tokens are empty */
86557057 8338 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
99a3b3c9 8339 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
42af6a67 8340
8341 /* now enter the loop */
8342 do {
b3d375b2 8343 s->gss_stat = s->gsslib->init_sec_context
8344 (s->gsslib,
8345 &s->gss_ctx,
8346 s->gss_srv_name,
4a693cfc 8347 conf_get_int(ssh->conf, CONF_gssapifwd),
b3d375b2 8348 &s->gss_rcvtok,
8349 &s->gss_sndtok);
42af6a67 8350
8351 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8352 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8353 logevent("GSSAPI authentication initialisation failed");
8354
b3d375b2 8355 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8356 &s->gss_buf) == SSH_GSS_OK) {
86557057 8357 logevent(s->gss_buf.value);
8358 sfree(s->gss_buf.value);
42af6a67 8359 }
8360
8361 break;
8362 }
8363 logevent("GSSAPI authentication initialised");
8364
8365 /* Client and server now exchange tokens until GSSAPI
8366 * no longer says CONTINUE_NEEDED */
8367
86557057 8368 if (s->gss_sndtok.length != 0) {
42af6a67 8369 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8370 ssh_pkt_addstring_start(s->pktout);
86557057 8371 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
42af6a67 8372 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8373 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
42af6a67 8374 }
8375
8376 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8377 crWaitUntilV(pktin);
8378 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8379 logevent("GSSAPI authentication - bad server response");
8380 s->gss_stat = SSH_GSS_FAILURE;
8381 break;
8382 }
86557057 8383 ssh_pkt_getstring(pktin, &data, &len);
8384 s->gss_rcvtok.value = data;
8385 s->gss_rcvtok.length = len;
42af6a67 8386 }
8387 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8388
8389 if (s->gss_stat != SSH_GSS_OK) {
b3d375b2 8390 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8391 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8392 continue;
8393 }
8394 logevent("GSSAPI authentication loop finished OK");
8395
8396 /* Now send the MIC */
8397
8398 s->pktout = ssh2_pkt_init(0);
8399 micoffset = s->pktout->length;
8400 ssh_pkt_addstring_start(s->pktout);
8401 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8402 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8403 ssh_pkt_addstring(s->pktout, ssh->username);
42af6a67 8404 ssh_pkt_addstring(s->pktout, "ssh-connection");
8405 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8406
86557057 8407 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8408 s->gss_buf.length = s->pktout->length - micoffset;
42af6a67 8409
b3d375b2 8410 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
42af6a67 8411 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8412 ssh_pkt_addstring_start(s->pktout);
86557057 8413 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
42af6a67 8414 ssh2_pkt_send(ssh, s->pktout);
b3d375b2 8415 s->gsslib->free_mic(s->gsslib, &mic);
42af6a67 8416
8417 s->gotit = FALSE;
8418
b3d375b2 8419 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8420 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
42af6a67 8421 continue;
8422#endif
edd0cb8a 8423 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8424
8425 /*
8426 * Keyboard-interactive authentication.
8427 */
edd0cb8a 8428
edd0cb8a 8429 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8430
acab36bc 8431 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
edd0cb8a 8432
8433 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8434 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8435 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8436 /* service requested */
8437 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8438 /* method */
8439 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8440 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8441 ssh2_pkt_send(ssh, s->pktout);
8221906d 8442
8443 logevent("Attempting keyboard-interactive authentication");
edd0cb8a 8444
8445 crWaitUntilV(pktin);
8446 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8447 /* Server is not willing to do keyboard-interactive
b8e3173d 8448 * at all (or, bizarrely but legally, accepts the
8449 * user without actually issuing any prompts).
8450 * Give up on it entirely. */
edd0cb8a 8451 s->gotit = TRUE;
edd0cb8a 8452 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8453 s->kbd_inter_refused = TRUE; /* don't try it again */
8454 continue;
8455 }
8456
8457 /*
b8e3173d 8458 * Loop while the server continues to send INFO_REQUESTs.
edd0cb8a 8459 */
b8e3173d 8460 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
edd0cb8a 8461
b8e3173d 8462 char *name, *inst, *lang;
8463 int name_len, inst_len, lang_len;
8464 int i;
8465
8466 /*
8467 * We've got a fresh USERAUTH_INFO_REQUEST.
8468 * Get the preamble and start building a prompt.
8469 */
8470 ssh_pkt_getstring(pktin, &name, &name_len);
8471 ssh_pkt_getstring(pktin, &inst, &inst_len);
8472 ssh_pkt_getstring(pktin, &lang, &lang_len);
8473 s->cur_prompt = new_prompts(ssh->frontend);
8474 s->cur_prompt->to_server = TRUE;
edd0cb8a 8475
b8e3173d 8476 /*
9ea10e78 8477 * Get any prompt(s) from the packet.
b8e3173d 8478 */
8479 s->num_prompts = ssh_pkt_getuint32(pktin);
8480 for (i = 0; i < s->num_prompts; i++) {
8481 char *prompt;
8482 int prompt_len;
8483 int echo;
8484 static char noprompt[] =
8485 "<server failed to send prompt>: ";
8486
8487 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8488 echo = ssh2_pkt_getbool(pktin);
8489 if (!prompt_len) {
8490 prompt = noprompt;
8491 prompt_len = lenof(noprompt)-1;
8492 }
8493 add_prompt(s->cur_prompt,
8494 dupprintf("%.*s", prompt_len, prompt),
b61f81bc 8495 echo);
edd0cb8a 8496 }
b8e3173d 8497
9874c9d7 8498 if (name_len) {
8499 /* FIXME: better prefix to distinguish from
8500 * local prompts? */
8501 s->cur_prompt->name =
8502 dupprintf("SSH server: %.*s", name_len, name);
8503 s->cur_prompt->name_reqd = TRUE;
8504 } else {
8505 s->cur_prompt->name =
8506 dupstr("SSH server authentication");
8507 s->cur_prompt->name_reqd = FALSE;
8508 }
8509 /* We add a prefix to try to make it clear that a prompt
8510 * has come from the server.
8511 * FIXME: ugly to print "Using..." in prompt _every_
8512 * time round. Can this be done more subtly? */
8513 /* Special case: for reasons best known to themselves,
8514 * some servers send k-i requests with no prompts and
8515 * nothing to display. Keep quiet in this case. */
8516 if (s->num_prompts || name_len || inst_len) {
8517 s->cur_prompt->instruction =
8518 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8519 inst_len ? "\n" : "", inst_len, inst);
8520 s->cur_prompt->instr_reqd = TRUE;
8521 } else {
8522 s->cur_prompt->instr_reqd = FALSE;
8523 }
8524
b8e3173d 8525 /*
9ea10e78 8526 * Display any instructions, and get the user's
8527 * response(s).
b8e3173d 8528 */
9ea10e78 8529 {
b8e3173d 8530 int ret; /* not live over crReturn */
8531 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8532 while (ret < 0) {
8533 ssh->send_ok = 1;
8534 crWaitUntilV(!pktin);
8535 ret = get_userpass_input(s->cur_prompt, in, inlen);
8536 ssh->send_ok = 0;
8537 }
8538 if (!ret) {
8539 /*
8540 * Failed to get responses. Terminate.
8541 */
8542 free_prompts(s->cur_prompt);
8543 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8544 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8545 TRUE);
8546 crStopV;
8547 }
edd0cb8a 8548 }
b8e3173d 8549
8550 /*
9ea10e78 8551 * Send the response(s) to the server.
b8e3173d 8552 */
8553 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
b8e3173d 8554 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8555 for (i=0; i < s->num_prompts; i++) {
8556 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8557 ssh2_pkt_addstring(s->pktout,
8558 s->cur_prompt->prompts[i]->result);
8559 end_log_omission(ssh, s->pktout);
8560 }
18524056 8561 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
b8e3173d 8562
c69784c0 8563 /*
8564 * Free the prompts structure from this iteration.
8565 * If there's another, a new one will be allocated
8566 * when we return to the top of this while loop.
8567 */
8568 free_prompts(s->cur_prompt);
8569
b8e3173d 8570 /*
8571 * Get the next packet in case it's another
8572 * INFO_REQUEST.
8573 */
8574 crWaitUntilV(pktin);
8575
edd0cb8a 8576 }
8577
8578 /*
b8e3173d 8579 * We should have SUCCESS or FAILURE now.
edd0cb8a 8580 */
b8e3173d 8581 s->gotit = TRUE;
edd0cb8a 8582
8583 } else if (s->can_passwd) {
8584
8585 /*
8586 * Plain old password authentication.
8587 */
8588 int ret; /* not live over crReturn */
e955d348 8589 int changereq_first_time; /* not live over crReturn */
edd0cb8a 8590
acab36bc 8591 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
edd0cb8a 8592
8593 s->cur_prompt = new_prompts(ssh->frontend);
8594 s->cur_prompt->to_server = TRUE;
8595 s->cur_prompt->name = dupstr("SSH password");
4a693cfc 8596 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
8597 ssh->username,
edd0cb8a 8598 ssh->savedhost),
b61f81bc 8599 FALSE);
edd0cb8a 8600
8601 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8602 while (ret < 0) {
8603 ssh->send_ok = 1;
8604 crWaitUntilV(!pktin);
8605 ret = get_userpass_input(s->cur_prompt, in, inlen);
8606 ssh->send_ok = 0;
8607 }
8608 if (!ret) {
8609 /*
8610 * Failed to get responses. Terminate.
8611 */
8612 free_prompts(s->cur_prompt);
8613 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8614 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8615 TRUE);
8616 crStopV;
8617 }
e955d348 8618 /*
8619 * Squirrel away the password. (We may need it later if
8620 * asked to change it.)
8621 */
8622 s->password = dupstr(s->cur_prompt->prompts[0]->result);
8623 free_prompts(s->cur_prompt);
edd0cb8a 8624
8625 /*
8626 * Send the password packet.
8627 *
95d2d262 8628 * We pad out the password packet to 256 bytes to make
8629 * it harder for an attacker to find the length of the
8630 * user's password.
1408a877 8631 *
95d2d262 8632 * Anyone using a password longer than 256 bytes
8633 * probably doesn't have much to worry about from
1408a877 8634 * people who find out how long their password is!
65a22376 8635 */
ff3187f6 8636 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8637 ssh2_pkt_addstring(s->pktout, ssh->username);
edd0cb8a 8638 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8639 /* service requested */
ff3187f6 8640 ssh2_pkt_addstring(s->pktout, "password");
8641 ssh2_pkt_addbool(s->pktout, FALSE);
8642 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
e955d348 8643 ssh2_pkt_addstring(s->pktout, s->password);
ff3187f6 8644 end_log_omission(ssh, s->pktout);
18524056 8645 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
0d43337a 8646 logevent("Sent password");
28f4d4f0 8647 s->type = AUTH_TYPE_PASSWORD;
edd0cb8a 8648
e955d348 8649 /*
8650 * Wait for next packet, in case it's a password change
8651 * request.
8652 */
8653 crWaitUntilV(pktin);
8654 changereq_first_time = TRUE;
8655
8656 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
8657
8658 /*
8659 * We're being asked for a new password
8660 * (perhaps not for the first time).
8661 * Loop until the server accepts it.
8662 */
8663
8664 int got_new = FALSE; /* not live over crReturn */
8665 char *prompt; /* not live over crReturn */
8666 int prompt_len; /* not live over crReturn */
8667
8668 {
8669 char *msg;
8670 if (changereq_first_time)
8671 msg = "Server requested password change";
8672 else
8673 msg = "Server rejected new password";
8674 logevent(msg);
8675 c_write_str(ssh, msg);
8676 c_write_str(ssh, "\r\n");
8677 }
8678
8679 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8680
8681 s->cur_prompt = new_prompts(ssh->frontend);
8682 s->cur_prompt->to_server = TRUE;
8683 s->cur_prompt->name = dupstr("New SSH password");
8684 s->cur_prompt->instruction =
8685 dupprintf("%.*s", prompt_len, prompt);
8686 s->cur_prompt->instr_reqd = TRUE;
d9add7bc 8687 /*
8688 * There's no explicit requirement in the protocol
8689 * for the "old" passwords in the original and
8690 * password-change messages to be the same, and
8691 * apparently some Cisco kit supports password change
8692 * by the user entering a blank password originally
8693 * and the real password subsequently, so,
8694 * reluctantly, we prompt for the old password again.
8695 *
8696 * (On the other hand, some servers don't even bother
8697 * to check this field.)
8698 */
8699 add_prompt(s->cur_prompt,
8700 dupstr("Current password (blank for previously entered password): "),
b61f81bc 8701 FALSE);
e955d348 8702 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
b61f81bc 8703 FALSE);
e955d348 8704 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
b61f81bc 8705 FALSE);
e955d348 8706
8707 /*
8708 * Loop until the user manages to enter the same
8709 * password twice.
8710 */
8711 while (!got_new) {
8712
8713 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8714 while (ret < 0) {
8715 ssh->send_ok = 1;
8716 crWaitUntilV(!pktin);
8717 ret = get_userpass_input(s->cur_prompt, in, inlen);
8718 ssh->send_ok = 0;
8719 }
8720 if (!ret) {
8721 /*
8722 * Failed to get responses. Terminate.
8723 */
8724 /* burn the evidence */
8725 free_prompts(s->cur_prompt);
8726 memset(s->password, 0, strlen(s->password));
8727 sfree(s->password);
8728 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8729 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8730 TRUE);
8731 crStopV;
8732 }
8733
8734 /*
d9add7bc 8735 * If the user specified a new original password
8736 * (IYSWIM), overwrite any previously specified
8737 * one.
8738 * (A side effect is that the user doesn't have to
8739 * re-enter it if they louse up the new password.)
8740 */
8741 if (s->cur_prompt->prompts[0]->result[0]) {
8742 memset(s->password, 0, strlen(s->password));
8743 /* burn the evidence */
8744 sfree(s->password);
8745 s->password =
8746 dupstr(s->cur_prompt->prompts[0]->result);
8747 }
8748
8749 /*
8750 * Check the two new passwords match.
e955d348 8751 */
d9add7bc 8752 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
8753 s->cur_prompt->prompts[2]->result)
e955d348 8754 == 0);
8755 if (!got_new)
8756 /* They don't. Silly user. */
8757 c_write_str(ssh, "Passwords do not match\r\n");
8758
8759 }
8760
8761 /*
8762 * Send the new password (along with the old one).
8763 * (see above for padding rationale)
8764 */
8765 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4a693cfc 8766 ssh2_pkt_addstring(s->pktout, ssh->username);
e955d348 8767 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8768 /* service requested */
8769 ssh2_pkt_addstring(s->pktout, "password");
8770 ssh2_pkt_addbool(s->pktout, TRUE);
8771 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8772 ssh2_pkt_addstring(s->pktout, s->password);
8773 ssh2_pkt_addstring(s->pktout,
d9add7bc 8774 s->cur_prompt->prompts[1]->result);
e955d348 8775 free_prompts(s->cur_prompt);
8776 end_log_omission(ssh, s->pktout);
18524056 8777 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
e955d348 8778 logevent("Sent new password");
8779
8780 /*
8781 * Now see what the server has to say about it.
8782 * (If it's CHANGEREQ again, it's not happy with the
8783 * new password.)
8784 */
8785 crWaitUntilV(pktin);
8786 changereq_first_time = FALSE;
8787
8788 }
8789
8790 /*
8791 * We need to reexamine the current pktin at the top
8792 * of the loop. Either:
8793 * - we weren't asked to change password at all, in
8794 * which case it's a SUCCESS or FAILURE with the
8795 * usual meaning
8796 * - we sent a new password, and the server was
8797 * either OK with it (SUCCESS or FAILURE w/partial
8798 * success) or unhappy with the _old_ password
8799 * (FAILURE w/o partial success)
8800 * In any of these cases, we go back to the top of
8801 * the loop and start again.
8802 */
8803 s->gotit = TRUE;
8804
8805 /*
8806 * We don't need the old password any more, in any
8807 * case. Burn the evidence.
8808 */
8809 memset(s->password, 0, strlen(s->password));
8810 sfree(s->password);
8811
1408a877 8812 } else {
854caca5 8813 char *str = dupprintf("No supported authentication methods available"
8814 " (server sent: %.*s)",
8815 methlen, methods);
edd0cb8a 8816
854caca5 8817 ssh_disconnect(ssh, str,
9e296bfa 8818 "No supported authentication methods available",
8819 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
8820 FALSE);
854caca5 8821 sfree(str);
8822
7ffdbc1a 8823 crStopV;
edd0cb8a 8824
65a22376 8825 }
edd0cb8a 8826
65a22376 8827 }
a1a1fae4 8828 }
6bbce591 8829 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7cca0d81 8830
edd0cb8a 8831 /* Clear up various bits and pieces from authentication. */
8832 if (s->publickey_blob) {
8833 sfree(s->publickey_blob);
8834 sfree(s->publickey_comment);
8835 }
94cd7c3a 8836 if (s->agent_response)
8837 sfree(s->agent_response);
edd0cb8a 8838
ab18ccff 8839 if (s->userauth_success) {
8840 /*
8841 * We've just received USERAUTH_SUCCESS, and we haven't sent any
8842 * packets since. Signal the transport layer to consider enacting
8843 * delayed compression.
8844 *
8845 * (Relying on we_are_in is not sufficient, as
8846 * draft-miller-secsh-compression-delayed is quite clear that it
8847 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
8848 * become set for other reasons.)
8849 */
8850 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
8851 }
8852
7cca0d81 8853 /*
a1a1fae4 8854 * Now the connection protocol has started, one way or another.
7cca0d81 8855 */
8856
0ed48730 8857 ssh->channels = newtree234(ssh_channelcmp);
8858
7cca0d81 8859 /*
b09eaa88 8860 * Set up handlers for some connection protocol messages, so we
8861 * don't have to handle them repeatedly in this coroutine.
8862 */
8863 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
8864 ssh2_msg_channel_window_adjust;
51df0ab5 8865 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
8866 ssh2_msg_global_request;
b09eaa88 8867
8868 /*
0ed48730 8869 * Create the main session channel.
7cca0d81 8870 */
4a693cfc 8871 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
feb02b4e 8872 ssh->mainchan = NULL;
4a693cfc 8873 } else if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
feb02b4e 8874 /*
8875 * Just start a direct-tcpip channel and use it as the main
8876 * channel.
8877 */
8878 ssh->mainchan = snew(struct ssh_channel);
8879 ssh->mainchan->ssh = ssh;
94bdfe40 8880 ssh2_channel_init(ssh->mainchan);
23828b7e 8881 logeventf(ssh,
8882 "Opening direct-tcpip channel to %s:%d in place of session",
4a693cfc 8883 conf_get_str(ssh->conf, CONF_ssh_nc_host),
8884 conf_get_int(ssh->conf, CONF_ssh_nc_port));
feb02b4e 8885 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8886 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
8887 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
feb02b4e 8888 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8889 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
4a693cfc 8890 ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_ssh_nc_host));
8891 ssh2_pkt_adduint32(s->pktout, conf_get_int(ssh->conf, CONF_ssh_nc_port));
feb02b4e 8892 /*
23828b7e 8893 * There's nothing meaningful to put in the originator
8894 * fields, but some servers insist on syntactically correct
8895 * information.
feb02b4e 8896 */
8897 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
8898 ssh2_pkt_adduint32(s->pktout, 0);
8899 ssh2_pkt_send(ssh, s->pktout);
8900
8901 crWaitUntilV(pktin);
8902 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8903 bombout(("Server refused to open a direct-tcpip channel"));
8904 crStopV;
8905 /* FIXME: error data comes back in FAILURE packet */
8906 }
8907 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8908 bombout(("Server's channel confirmation cited wrong channel"));
8909 crStopV;
8910 }
8911 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8912 ssh->mainchan->halfopen = FALSE;
8913 ssh->mainchan->type = CHAN_MAINSESSION;
feb02b4e 8914 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8915 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
feb02b4e 8916 add234(ssh->channels, ssh->mainchan);
8917 update_specials_menu(ssh->frontend);
23828b7e 8918 logevent("Opened direct-tcpip channel");
feb02b4e 8919 ssh->ncmode = TRUE;
8920 } else {
0ed48730 8921 ssh->mainchan = snew(struct ssh_channel);
8922 ssh->mainchan->ssh = ssh;
94bdfe40 8923 ssh2_channel_init(ssh->mainchan);
ff3187f6 8924 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8925 ssh2_pkt_addstring(s->pktout, "session");
8926 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
ff3187f6 8927 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 8928 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 8929 ssh2_pkt_send(ssh, s->pktout);
8930 crWaitUntilV(pktin);
8931 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 8932 bombout(("Server refused to open a session"));
8933 crStopV;
8934 /* FIXME: error data comes back in FAILURE packet */
8935 }
ff3187f6 8936 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 8937 bombout(("Server's channel confirmation cited wrong channel"));
8938 crStopV;
8939 }
ff3187f6 8940 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 8941 ssh->mainchan->halfopen = FALSE;
0ed48730 8942 ssh->mainchan->type = CHAN_MAINSESSION;
ff3187f6 8943 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8944 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 8945 add234(ssh->channels, ssh->mainchan);
62638676 8946 update_specials_menu(ssh->frontend);
0ed48730 8947 logevent("Opened channel for session");
feb02b4e 8948 ssh->ncmode = FALSE;
8949 }
7cca0d81 8950
8951 /*
51df0ab5 8952 * Now we have a channel, make dispatch table entries for
8953 * general channel-based messages.
8954 */
8955 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8956 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8957 ssh2_msg_channel_data;
8958 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8959 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8960 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8961 ssh2_msg_channel_open_confirmation;
8962 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8963 ssh2_msg_channel_open_failure;
8964 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8965 ssh2_msg_channel_request;
8966 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8967 ssh2_msg_channel_open;
8968
4a693cfc 8969 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
3361b80a 8970 /*
8971 * This message indicates to the server that we promise
8972 * not to try to run any other channel in parallel with
8973 * this one, so it's safe for it to advertise a very large
8974 * window and leave the flow control to TCP.
8975 */
8976 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8977 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8978 ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
8979 ssh2_pkt_addbool(s->pktout, 0); /* no reply */
8980 ssh2_pkt_send(ssh, s->pktout);
8981 }
8982
51df0ab5 8983 /*
783415f8 8984 * Potentially enable X11 forwarding.
8985 */
4a693cfc 8986 if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_x11_forward) &&
8987 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
8988 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
32874aea 8989 logevent("Requesting X11 forwarding");
ff3187f6 8990 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8991 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8992 ssh2_pkt_addstring(s->pktout, "x11-req");
8993 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8994 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8def70c3 8995 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname);
f68353be 8996 /*
8997 * Note that while we blank the X authentication data here, we don't
8998 * take any special action to blank the start of an X11 channel,
8999 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
9000 * without having session blanking enabled is likely to leak your
9001 * cookie into the log.
9002 */
178c3872 9003 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8def70c3 9004 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring);
178c3872 9005 end_log_omission(ssh, s->pktout);
8def70c3 9006 ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum);
ff3187f6 9007 ssh2_pkt_send(ssh, s->pktout);
32874aea 9008
b09eaa88 9009 crWaitUntilV(pktin);
32874aea 9010
ff3187f6 9011 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9012 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 9013 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 9014 " packet type %d", pktin->type));
7ffdbc1a 9015 crStopV;
32874aea 9016 }
9017 logevent("X11 forwarding refused");
9018 } else {
9019 logevent("X11 forwarding enabled");
51470298 9020 ssh->X11_fwd_enabled = TRUE;
32874aea 9021 }
783415f8 9022 }
9023
9024 /*
bc240b21 9025 * Enable port forwardings.
9026 */
4a693cfc 9027 ssh_setup_portfwd(ssh, ssh->conf);
bc240b21 9028
9029 /*
36c2a3e9 9030 * Potentially enable agent forwarding.
9031 */
4a693cfc 9032 if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
32874aea 9033 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 9034 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9035 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
9036 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
9037 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9038 ssh2_pkt_send(ssh, s->pktout);
32874aea 9039
b09eaa88 9040 crWaitUntilV(pktin);
32874aea 9041
ff3187f6 9042 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9043 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 9044 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 9045 " packet type %d", pktin->type));
7ffdbc1a 9046 crStopV;
32874aea 9047 }
9048 logevent("Agent forwarding refused");
9049 } else {
9050 logevent("Agent forwarding enabled");
51470298 9051 ssh->agentfwd_enabled = TRUE;
32874aea 9052 }
36c2a3e9 9053 }
9054
9055 /*
7cca0d81 9056 * Now allocate a pty for the session.
9057 */
4a693cfc 9058 if (ssh->mainchan && !ssh->ncmode && !conf_get_int(ssh->conf, CONF_nopty)) {
a5dd8467 9059 /* Unpick the terminal-speed string. */
9060 /* XXX perhaps we should allow no speeds to be sent. */
db219738 9061 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4a693cfc 9062 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 9063 /* Build the pty request. */
ff3187f6 9064 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9065 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
9066 ssh2_pkt_addstring(s->pktout, "pty-req");
9067 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
4a693cfc 9068 ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_termtype));
ff3187f6 9069 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
9070 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
9071 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
9072 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
9073 ssh2_pkt_addstring_start(s->pktout);
4a693cfc 9074 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)s->pktout);
c6ccd5c2 9075 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
ff3187f6 9076 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
c6ccd5c2 9077 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
ff3187f6 9078 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
9079 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
9080 ssh2_pkt_send(ssh, s->pktout);
51470298 9081 ssh->state = SSH_STATE_INTERMED;
32874aea 9082
b09eaa88 9083 crWaitUntilV(pktin);
32874aea 9084
ff3187f6 9085 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9086 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 9087 bombout(("Unexpected response to pty request:"
ff3187f6 9088 " packet type %d", pktin->type));
7ffdbc1a 9089 crStopV;
32874aea 9090 }
51470298 9091 c_write_str(ssh, "Server refused to allocate pty\r\n");
9092 ssh->editing = ssh->echoing = 1;
32874aea 9093 } else {
a5dd8467 9094 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 9095 ssh->ospeed, ssh->ispeed);
4a202fc6 9096 ssh->got_pty = TRUE;
32874aea 9097 }
0965bee0 9098 } else {
51470298 9099 ssh->editing = ssh->echoing = 1;
7cca0d81 9100 }
9101
9102 /*
73feed4f 9103 * Send environment variables.
9104 *
9105 * Simplest thing here is to send all the requests at once, and
9106 * then wait for a whole bunch of successes or failures.
9107 */
4a693cfc 9108 if (ssh->mainchan && !ssh->ncmode) {
9109 char *key, *val;
73feed4f 9110
9111 s->num_env = 0;
9112
4a693cfc 9113 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
9114 val != NULL;
9115 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
ff3187f6 9116 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9117 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
9118 ssh2_pkt_addstring(s->pktout, "env");
9119 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
4a693cfc 9120 ssh2_pkt_addstring(s->pktout, key);
ff3187f6 9121 ssh2_pkt_addstring(s->pktout, val);
9122 ssh2_pkt_send(ssh, s->pktout);
73feed4f 9123
9124 s->num_env++;
9125 }
9126
4a693cfc 9127 if (s->num_env) {
9128 logeventf(ssh, "Sent %d environment variables", s->num_env);
73feed4f 9129
4a693cfc 9130 s->env_ok = 0;
9131 s->env_left = s->num_env;
73feed4f 9132
4a693cfc 9133 while (s->env_left > 0) {
9134 crWaitUntilV(pktin);
73feed4f 9135
4a693cfc 9136 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9137 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9138 bombout(("Unexpected response to environment request:"
9139 " packet type %d", pktin->type));
9140 crStopV;
9141 }
9142 } else {
9143 s->env_ok++;
73feed4f 9144 }
73feed4f 9145
4a693cfc 9146 s->env_left--;
9147 }
73feed4f 9148
4a693cfc 9149 if (s->env_ok == s->num_env) {
9150 logevent("All environment variables successfully set");
9151 } else if (s->env_ok == 0) {
9152 logevent("All environment variables refused");
9153 c_write_str(ssh, "Server refused to set environment variables\r\n");
9154 } else {
9155 logeventf(ssh, "%d environment variables refused",
9156 s->num_env - s->env_ok);
9157 c_write_str(ssh, "Server refused to set all environment variables\r\n");
9158 }
73feed4f 9159 }
9160 }
9161
9162 /*
fd5e5847 9163 * Start a shell or a remote command. We may have to attempt
9164 * this twice if the config data has provided a second choice
9165 * of command.
7cca0d81 9166 */
feb02b4e 9167 if (ssh->mainchan && !ssh->ncmode) while (1) {
fd5e5847 9168 int subsys;
9169 char *cmd;
9170
51470298 9171 if (ssh->fallback_cmd) {
4a693cfc 9172 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9173 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
fd5e5847 9174 } else {
4a693cfc 9175 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9176 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
fd5e5847 9177 }
9178
ff3187f6 9179 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9180 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 9181 if (subsys) {
ff3187f6 9182 ssh2_pkt_addstring(s->pktout, "subsystem");
9183 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9184 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 9185 } else if (*cmd) {
ff3187f6 9186 ssh2_pkt_addstring(s->pktout, "exec");
9187 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9188 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 9189 } else {
ff3187f6 9190 ssh2_pkt_addstring(s->pktout, "shell");
9191 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 9192 }
ff3187f6 9193 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 9194
9195 crWaitUntilV(pktin);
9196
ff3187f6 9197 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9198 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 9199 bombout(("Unexpected response to shell/command request:"
ff3187f6 9200 " packet type %d", pktin->type));
7ffdbc1a 9201 crStopV;
fd5e5847 9202 }
9203 /*
9204 * We failed to start the command. If this is the
9205 * fallback command, we really are finished; if it's
9206 * not, and if the fallback command exists, try falling
9207 * back to it before complaining.
9208 */
4a693cfc 9209 if (!ssh->fallback_cmd &&
9210 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
fd5e5847 9211 logevent("Primary command failed; attempting fallback");
51470298 9212 ssh->fallback_cmd = TRUE;
fd5e5847 9213 continue;
9214 }
6b5cf8b4 9215 bombout(("Server refused to start a shell/command"));
7ffdbc1a 9216 crStopV;
fd5e5847 9217 } else {
9218 logevent("Started a shell/command");
32874aea 9219 }
fd5e5847 9220 break;
7cca0d81 9221 }
9222
51470298 9223 ssh->state = SSH_STATE_SESSION;
9224 if (ssh->size_needed)
9225 ssh_size(ssh, ssh->term_width, ssh->term_height);
9226 if (ssh->eof_needed)
9227 ssh_special(ssh, TS_EOF);
6e48c3fe 9228
7cca0d81 9229 /*
0e443c99 9230 * All the initial channel requests are done, so install the default
9231 * failure handler.
9232 */
837d6ba6 9233 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success;
0e443c99 9234 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure;
9235
9236 /*
7cca0d81 9237 * Transfer data!
9238 */
b9d7bcad 9239 if (ssh->ldisc)
9240 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 9241 if (ssh->mainchan)
9242 ssh->send_ok = 1;
7cca0d81 9243 while (1) {
e5574168 9244 crReturnV;
51470298 9245 s->try_send = FALSE;
ff3187f6 9246 if (pktin) {
2b7540a7 9247
51df0ab5 9248 /*
9249 * _All_ the connection-layer packets we expect to
9250 * receive are now handled by the dispatch table.
9251 * Anything that reaches here must be bogus.
9252 */
32874aea 9253
51df0ab5 9254 bombout(("Strange packet received: type %d", pktin->type));
9255 crStopV;
0ed48730 9256 } else if (ssh->mainchan) {
32874aea 9257 /*
9258 * We have spare data. Add it to the channel buffer.
9259 */
d8baa528 9260 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 9261 s->try_send = TRUE;
32874aea 9262 }
51470298 9263 if (s->try_send) {
32874aea 9264 int i;
9265 struct ssh_channel *c;
9266 /*
9267 * Try to send data on all channels if we can.
9268 */
1bfc7e93 9269 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
78280721 9270 ssh2_try_send_and_unthrottle(ssh, c);
7cca0d81 9271 }
e5574168 9272 }
9273
9274 crFinishV;
9275}
9276
9277/*
2e85c969 9278 * Handlers for SSH-2 messages that might arrive at any moment.
b09eaa88 9279 */
409bfa77 9280static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 9281{
9282 /* log reason code in disconnect message */
9283 char *buf, *msg;
60860bc3 9284 int reason, msglen;
b09eaa88 9285
9286 reason = ssh_pkt_getuint32(pktin);
9287 ssh_pkt_getstring(pktin, &msg, &msglen);
9288
9289 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9290 buf = dupprintf("Received disconnect message (%s)",
9291 ssh2_disconnect_reasons[reason]);
9292 } else {
9293 buf = dupprintf("Received disconnect message (unknown"
9294 " type %d)", reason);
9295 }
9296 logevent(buf);
9297 sfree(buf);
60860bc3 9298 buf = dupprintf("Disconnection message text: %.*s",
9299 msglen, msg);
b09eaa88 9300 logevent(buf);
60860bc3 9301 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
b09eaa88 9302 reason,
9303 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9304 ssh2_disconnect_reasons[reason] : "unknown",
60860bc3 9305 msglen, msg));
b09eaa88 9306 sfree(buf);
9307}
9308
409bfa77 9309static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 9310{
9311 /* log the debug message */
fb983202 9312 char *msg;
b09eaa88 9313 int msglen;
b09eaa88 9314
3ab79841 9315 /* XXX maybe we should actually take notice of the return value */
9316 ssh2_pkt_getbool(pktin);
b09eaa88 9317 ssh_pkt_getstring(pktin, &msg, &msglen);
9318
fb983202 9319 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 9320}
9321
409bfa77 9322static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 9323{
9324 struct Packet *pktout;
9325 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9326 ssh2_pkt_adduint32(pktout, pktin->sequence);
9327 /*
9328 * UNIMPLEMENTED messages MUST appear in the same order as the
9329 * messages they respond to. Hence, never queue them.
9330 */
9331 ssh2_pkt_send_noqueue(ssh, pktout);
9332}
9333
9334/*
2e85c969 9335 * Handle the top-level SSH-2 protocol.
7cca0d81 9336 */
b09eaa88 9337static void ssh2_protocol_setup(Ssh ssh)
9338{
9339 int i;
9340
9341 /*
9342 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9343 */
9344 for (i = 0; i < 256; i++)
9345 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9346
9347 /*
9348 * Any message we actually understand, we set to NULL so that
9349 * the coroutines will get it.
9350 */
9351 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
9352 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
9353 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
9354 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
9355 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
9356 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
9357 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
9358 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
9359 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
9360 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
9361 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
9362 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
9363 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
9364 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
9365 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9366 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
9367 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
9368 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
9369 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
9370 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
9371 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
9372 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
9373 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
9374 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
9375 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
9376 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
9377 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
9378 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
9379 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
9380 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
9381 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
9382 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
9383 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
9384
9385 /*
9386 * These special message types we install handlers for.
9387 */
9388 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
2e85c969 9389 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
b09eaa88 9390 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9391}
9392
9442dd57 9393static void ssh2_timer(void *ctx, long now)
9394{
9395 Ssh ssh = (Ssh)ctx;
9396
ecbb0000 9397 if (ssh->state == SSH_STATE_CLOSED)
9398 return;
9399
4a693cfc 9400 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9442dd57 9401 now - ssh->next_rekey >= 0) {
f382c87d 9402 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 9403 }
9404}
9405
1c1a7262 9406static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 9407 struct Packet *pktin)
7cca0d81 9408{
1c1a7262 9409 unsigned char *in = (unsigned char *)vin;
b09eaa88 9410 if (ssh->state == SSH_STATE_CLOSED)
9411 return;
9412
9442dd57 9413 if (pktin) {
9414 ssh->incoming_data_size += pktin->encrypted_len;
9415 if (!ssh->kex_in_progress &&
d57f70af 9416 ssh->max_data_size != 0 &&
9417 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9418 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 9419 }
9420
b09eaa88 9421 if (pktin && ssh->packet_dispatch[pktin->type]) {
9422 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 9423 return;
b09eaa88 9424 }
9425
9426 if (!ssh->protocol_initial_phase_done ||
9427 (pktin && pktin->type >= 20 && pktin->type < 50)) {
9428 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
9429 !ssh->protocol_initial_phase_done) {
9430 ssh->protocol_initial_phase_done = TRUE;
9431 /*
9432 * Allow authconn to initialise itself.
9433 */
9434 do_ssh2_authconn(ssh, NULL, 0, NULL);
9435 }
9436 } else {
9437 do_ssh2_authconn(ssh, in, inlen, pktin);
9438 }
7cca0d81 9439}
9440
4a693cfc 9441static void ssh_cache_conf_values(Ssh ssh)
9442{
9443 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9444}
9445
7cca0d81 9446/*
8df7a775 9447 * Called to set up the connection.
374330e2 9448 *
9449 * Returns an error message, or NULL on success.
374330e2 9450 */
cbe2d68f 9451static const char *ssh_init(void *frontend_handle, void **backend_handle,
4a693cfc 9452 Conf *conf, char *host, int port, char **realhost,
9453 int nodelay, int keepalive)
32874aea 9454{
cbe2d68f 9455 const char *p;
51470298 9456 Ssh ssh;
9457
3d88e64d 9458 ssh = snew(struct ssh_tag);
4a693cfc 9459 ssh->conf = conf_copy(conf);
9460 ssh_cache_conf_values(ssh);
125105d1 9461 ssh->version = 0; /* when not ready yet */
51470298 9462 ssh->s = NULL;
9463 ssh->cipher = NULL;
371e569c 9464 ssh->v1_cipher_ctx = NULL;
0183b242 9465 ssh->crcda_ctx = NULL;
51470298 9466 ssh->cscipher = NULL;
371e569c 9467 ssh->cs_cipher_ctx = NULL;
51470298 9468 ssh->sccipher = NULL;
371e569c 9469 ssh->sc_cipher_ctx = NULL;
51470298 9470 ssh->csmac = NULL;
a8327734 9471 ssh->cs_mac_ctx = NULL;
51470298 9472 ssh->scmac = NULL;
e0e1a00d 9473 ssh->sc_mac_ctx = NULL;
51470298 9474 ssh->cscomp = NULL;
5366aed8 9475 ssh->cs_comp_ctx = NULL;
51470298 9476 ssh->sccomp = NULL;
5366aed8 9477 ssh->sc_comp_ctx = NULL;
51470298 9478 ssh->kex = NULL;
389aa499 9479 ssh->kex_ctx = NULL;
51470298 9480 ssh->hostkey = NULL;
9481 ssh->exitcode = -1;
ac934965 9482 ssh->close_expected = FALSE;
9e296bfa 9483 ssh->clean_exit = FALSE;
51470298 9484 ssh->state = SSH_STATE_PREPACKET;
9485 ssh->size_needed = FALSE;
9486 ssh->eof_needed = FALSE;
b9d7bcad 9487 ssh->ldisc = NULL;
a8327734 9488 ssh->logctx = NULL;
51470298 9489 ssh->deferred_send_data = NULL;
9490 ssh->deferred_len = 0;
9491 ssh->deferred_size = 0;
9492 ssh->fallback_cmd = 0;
acab36bc 9493 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9494 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8def70c3 9495 ssh->x11disp = NULL;
be738459 9496 ssh->v1_compressing = FALSE;
51470298 9497 ssh->v2_outgoing_sequence = 0;
9498 ssh->ssh1_rdpkt_crstate = 0;
9499 ssh->ssh2_rdpkt_crstate = 0;
9500 ssh->do_ssh_init_crstate = 0;
9501 ssh->ssh_gotdata_crstate = 0;
b09eaa88 9502 ssh->do_ssh1_connection_crstate = 0;
51470298 9503 ssh->do_ssh1_login_crstate = 0;
9504 ssh->do_ssh2_transport_crstate = 0;
9505 ssh->do_ssh2_authconn_crstate = 0;
9506 ssh->do_ssh_init_state = NULL;
9507 ssh->do_ssh1_login_state = NULL;
9508 ssh->do_ssh2_transport_state = NULL;
9509 ssh->do_ssh2_authconn_state = NULL;
4320baf7 9510 ssh->v_c = NULL;
9511 ssh->v_s = NULL;
6571dbfd 9512 ssh->mainchan = NULL;
968d2d92 9513 ssh->throttled_all = 0;
9514 ssh->v1_stdout_throttling = 0;
590f6a5f 9515 ssh->queue = NULL;
9516 ssh->queuelen = ssh->queuesize = 0;
9517 ssh->queueing = FALSE;
06fadff5 9518 ssh->qhead = ssh->qtail = NULL;
e13bba36 9519 ssh->deferred_rekey_reason = NULL;
3d9449a1 9520 bufchain_init(&ssh->queued_incoming_data);
9521 ssh->frozen = FALSE;
4a693cfc 9522 ssh->username = NULL;
bc06669b 9523 ssh->sent_console_eof = FALSE;
4a202fc6 9524 ssh->got_pty = FALSE;
51470298 9525
9526 *backend_handle = ssh;
32874aea 9527
8f203108 9528#ifdef MSCRYPTOAPI
32874aea 9529 if (crypto_startup() == 0)
8f203108 9530 return "Microsoft high encryption pack not installed!";
9531#endif
374330e2 9532
51470298 9533 ssh->frontend = frontend_handle;
4a693cfc 9534 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9535 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
887035a5 9536
fabd1805 9537 ssh->channels = NULL;
9538 ssh->rportfwds = NULL;
f47a5ffb 9539 ssh->portfwds = NULL;
fabd1805 9540
51470298 9541 ssh->send_ok = 0;
9542 ssh->editing = 0;
9543 ssh->echoing = 0;
ff68564b 9544 ssh->conn_throttle_count = 0;
51470298 9545 ssh->overall_bufsize = 0;
9546 ssh->fallback_cmd = 0;
8df7a775 9547
3648d4c5 9548 ssh->protocol = NULL;
9549
b09eaa88 9550 ssh->protocol_initial_phase_done = FALSE;
9551
39934deb 9552 ssh->pinger = NULL;
9553
9442dd57 9554 ssh->incoming_data_size = ssh->outgoing_data_size =
9555 ssh->deferred_data_size = 0L;
4a693cfc 9556 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9557 CONF_ssh_rekey_data));
9442dd57 9558 ssh->kex_in_progress = FALSE;
9559
1e00c92b 9560#ifndef NO_GSSAPI
9561 ssh->gsslibs = NULL;
9562#endif
9563
79bf227b 9564 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 9565 if (p != NULL)
9566 return p;
374330e2 9567
5d17ccfc 9568 random_ref();
9569
374330e2 9570 return NULL;
9571}
9572
fabd1805 9573static void ssh_free(void *handle)
9574{
9575 Ssh ssh = (Ssh) handle;
9576 struct ssh_channel *c;
9577 struct ssh_rportfwd *pf;
9578
9579 if (ssh->v1_cipher_ctx)
9580 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9581 if (ssh->cs_cipher_ctx)
9582 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9583 if (ssh->sc_cipher_ctx)
9584 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9585 if (ssh->cs_mac_ctx)
9586 ssh->csmac->free_context(ssh->cs_mac_ctx);
9587 if (ssh->sc_mac_ctx)
9588 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 9589 if (ssh->cs_comp_ctx) {
9590 if (ssh->cscomp)
9591 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9592 else
9593 zlib_compress_cleanup(ssh->cs_comp_ctx);
9594 }
9595 if (ssh->sc_comp_ctx) {
9596 if (ssh->sccomp)
9597 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9598 else
9599 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9600 }
fabd1805 9601 if (ssh->kex_ctx)
9602 dh_cleanup(ssh->kex_ctx);
9603 sfree(ssh->savedhost);
9604
590f6a5f 9605 while (ssh->queuelen-- > 0)
9606 ssh_free_packet(ssh->queue[ssh->queuelen]);
9607 sfree(ssh->queue);
9608
06fadff5 9609 while (ssh->qhead) {
9610 struct queued_handler *qh = ssh->qhead;
9611 ssh->qhead = qh->next;
9612 sfree(ssh->qhead);
9613 }
9614 ssh->qhead = ssh->qtail = NULL;
9615
fabd1805 9616 if (ssh->channels) {
9617 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9618 switch (c->type) {
9619 case CHAN_X11:
9620 if (c->u.x11.s != NULL)
9621 x11_close(c->u.x11.s);
9622 break;
9623 case CHAN_SOCKDATA:
409eca86 9624 case CHAN_SOCKDATA_DORMANT:
fabd1805 9625 if (c->u.pfd.s != NULL)
9626 pfd_close(c->u.pfd.s);
9627 break;
9628 }
9629 sfree(c);
9630 }
9631 freetree234(ssh->channels);
cdb52705 9632 ssh->channels = NULL;
fabd1805 9633 }
9634
9635 if (ssh->rportfwds) {
9636 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8aea57fd 9637 free_rportfwd(pf);
fabd1805 9638 freetree234(ssh->rportfwds);
cdb52705 9639 ssh->rportfwds = NULL;
fabd1805 9640 }
9641 sfree(ssh->deferred_send_data);
8def70c3 9642 if (ssh->x11disp)
9643 x11_free_display(ssh->x11disp);
fabd1805 9644 sfree(ssh->do_ssh_init_state);
9645 sfree(ssh->do_ssh1_login_state);
9646 sfree(ssh->do_ssh2_transport_state);
9647 sfree(ssh->do_ssh2_authconn_state);
4320baf7 9648 sfree(ssh->v_c);
9649 sfree(ssh->v_s);
42af6a67 9650 sfree(ssh->fullhostname);
679539d7 9651 if (ssh->crcda_ctx) {
9652 crcda_free_context(ssh->crcda_ctx);
9653 ssh->crcda_ctx = NULL;
9654 }
fabd1805 9655 if (ssh->s)
ac934965 9656 ssh_do_close(ssh, TRUE);
9442dd57 9657 expire_timer_context(ssh);
39934deb 9658 if (ssh->pinger)
9659 pinger_free(ssh->pinger);
3d9449a1 9660 bufchain_clear(&ssh->queued_incoming_data);
4a693cfc 9661 sfree(ssh->username);
9662 conf_free(ssh->conf);
1e00c92b 9663#ifndef NO_GSSAPI
9664 if (ssh->gsslibs)
9665 ssh_gss_cleanup(ssh->gsslibs);
9666#endif
ee50e8b6 9667 sfree(ssh);
5d17ccfc 9668
9669 random_unref();
fabd1805 9670}
9671
374330e2 9672/*
86916870 9673 * Reconfigure the SSH backend.
86916870 9674 */
4a693cfc 9675static void ssh_reconfig(void *handle, Conf *conf)
86916870 9676{
9677 Ssh ssh = (Ssh) handle;
e13bba36 9678 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 9679 unsigned long old_max_data_size;
4a693cfc 9680 int i, rekey_time;
e6c1536e 9681
4a693cfc 9682 pinger_reconfig(ssh->pinger, ssh->conf, conf);
3b6606c7 9683 if (ssh->portfwds)
4a693cfc 9684 ssh_setup_portfwd(ssh, conf);
e6c1536e 9685
4a693cfc 9686 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
9687 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
9688 rekey_time != 0) {
9689 long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
e6c1536e 9690 long now = GETTICKCOUNT();
9691
9692 if (new_next - now < 0) {
f382c87d 9693 rekeying = "timeout shortened";
e6c1536e 9694 } else {
9695 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9696 }
9697 }
9698
9699 old_max_data_size = ssh->max_data_size;
4a693cfc 9700 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9701 CONF_ssh_rekey_data));
e6c1536e 9702 if (old_max_data_size != ssh->max_data_size &&
9703 ssh->max_data_size != 0) {
9704 if (ssh->outgoing_data_size > ssh->max_data_size ||
9705 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 9706 rekeying = "data limit lowered";
e6c1536e 9707 }
9708
4a693cfc 9709 if (conf_get_int(ssh->conf, CONF_compression) !=
9710 conf_get_int(conf, CONF_compression)) {
f382c87d 9711 rekeying = "compression setting changed";
e13bba36 9712 rekey_mandatory = TRUE;
9713 }
9714
4a693cfc 9715 for (i = 0; i < CIPHER_MAX; i++)
9716 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
9717 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
9718 rekeying = "cipher settings changed";
9719 rekey_mandatory = TRUE;
9720 }
9721 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
9722 conf_get_int(conf, CONF_ssh2_des_cbc)) {
f382c87d 9723 rekeying = "cipher settings changed";
e13bba36 9724 rekey_mandatory = TRUE;
e6c1536e 9725 }
9726
4a693cfc 9727 conf_free(ssh->conf);
9728 ssh->conf = conf_copy(conf);
9729 ssh_cache_conf_values(ssh);
e13bba36 9730
9731 if (rekeying) {
9732 if (!ssh->kex_in_progress) {
9733 do_ssh2_transport(ssh, rekeying, -1, NULL);
9734 } else if (rekey_mandatory) {
9735 ssh->deferred_rekey_reason = rekeying;
9736 }
9737 }
86916870 9738}
9739
9740/*
86dc445a 9741 * Called to send data down the SSH connection.
374330e2 9742 */
51470298 9743static int ssh_send(void *handle, char *buf, int len)
32874aea 9744{
51470298 9745 Ssh ssh = (Ssh) handle;
9746
9747 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9748 return 0;
374330e2 9749
d8baa528 9750 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 9751
51470298 9752 return ssh_sendbuffer(ssh);
5471d09a 9753}
9754
9755/*
9756 * Called to query the current amount of buffered stdin data.
9757 */
51470298 9758static int ssh_sendbuffer(void *handle)
5471d09a 9759{
51470298 9760 Ssh ssh = (Ssh) handle;
5471d09a 9761 int override_value;
9762
51470298 9763 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 9764 return 0;
9765
9766 /*
9767 * If the SSH socket itself has backed up, add the total backup
9768 * size on that to any individual buffer on the stdin channel.
9769 */
9770 override_value = 0;
51470298 9771 if (ssh->throttled_all)
9772 override_value = ssh->overall_bufsize;
5471d09a 9773
51470298 9774 if (ssh->version == 1) {
5471d09a 9775 return override_value;
51470298 9776 } else if (ssh->version == 2) {
bc06669b 9777 if (!ssh->mainchan)
5471d09a 9778 return override_value;
9779 else
51470298 9780 return (override_value +
9781 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 9782 }
9783
9784 return 0;
374330e2 9785}
9786
9787/*
6e48c3fe 9788 * Called to set the size of the window from SSH's POV.
374330e2 9789 */
51470298 9790static void ssh_size(void *handle, int width, int height)
32874aea 9791{
51470298 9792 Ssh ssh = (Ssh) handle;
ff3187f6 9793 struct Packet *pktout;
51470298 9794
9795 ssh->term_width = width;
9796 ssh->term_height = height;
f278d6f8 9797
51470298 9798 switch (ssh->state) {
374330e2 9799 case SSH_STATE_BEFORE_SIZE:
3687d221 9800 case SSH_STATE_PREPACKET:
21248260 9801 case SSH_STATE_CLOSED:
374330e2 9802 break; /* do nothing */
9803 case SSH_STATE_INTERMED:
51470298 9804 ssh->size_needed = TRUE; /* buffer for later */
374330e2 9805 break;
9806 case SSH_STATE_SESSION:
4a693cfc 9807 if (!conf_get_int(ssh->conf, CONF_nopty)) {
51470298 9808 if (ssh->version == 1) {
9809 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
9810 PKT_INT, ssh->term_height,
9811 PKT_INT, ssh->term_width,
32874aea 9812 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 9813 } else if (ssh->mainchan) {
ff3187f6 9814 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9815 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9816 ssh2_pkt_addstring(pktout, "window-change");
9817 ssh2_pkt_addbool(pktout, 0);
9818 ssh2_pkt_adduint32(pktout, ssh->term_width);
9819 ssh2_pkt_adduint32(pktout, ssh->term_height);
9820 ssh2_pkt_adduint32(pktout, 0);
9821 ssh2_pkt_adduint32(pktout, 0);
9822 ssh2_pkt_send(ssh, pktout);
32874aea 9823 }
9824 }
9825 break;
374330e2 9826 }
9827}
9828
9829/*
125105d1 9830 * Return a list of the special codes that make sense in this
9831 * protocol.
9832 */
9833static const struct telnet_special *ssh_get_specials(void *handle)
9834{
786ba75e 9835 static const struct telnet_special ssh1_ignore_special[] = {
9836 {"IGNORE message", TS_NOP}
9837 };
cf6ddb95 9838 static const struct telnet_special ssh2_ignore_special[] = {
62638676 9839 {"IGNORE message", TS_NOP},
cf6ddb95 9840 };
9841 static const struct telnet_special ssh2_rekey_special[] = {
9442dd57 9842 {"Repeat key exchange", TS_REKEY},
62638676 9843 };
9844 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 9845 {NULL, TS_SEP},
9846 {"Break", TS_BRK},
bccbeb71 9847 /* These are the signal names defined by RFC 4254.
6f2d0cde 9848 * They include all the ISO C signals, but are a subset of the POSIX
9849 * required signals. */
9850 {"SIGINT (Interrupt)", TS_SIGINT},
9851 {"SIGTERM (Terminate)", TS_SIGTERM},
9852 {"SIGKILL (Kill)", TS_SIGKILL},
9853 {"SIGQUIT (Quit)", TS_SIGQUIT},
9854 {"SIGHUP (Hangup)", TS_SIGHUP},
9855 {"More signals", TS_SUBMENU},
9856 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
9857 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
9858 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
9859 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
9860 {NULL, TS_EXITMENU}
62638676 9861 };
9862 static const struct telnet_special specials_end[] = {
6f2d0cde 9863 {NULL, TS_EXITMENU}
62638676 9864 };
786ba75e 9865 /* XXX review this length for any changes: */
cf6ddb95 9866 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
9867 lenof(ssh2_rekey_special) +
62638676 9868 lenof(ssh2_session_specials) +
9869 lenof(specials_end)];
125105d1 9870 Ssh ssh = (Ssh) handle;
62638676 9871 int i = 0;
9872#define ADD_SPECIALS(name) \
9873 do { \
9874 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9875 memcpy(&ssh_specials[i], name, sizeof name); \
9876 i += lenof(name); \
9877 } while(0)
125105d1 9878
9879 if (ssh->version == 1) {
62638676 9880 /* Don't bother offering IGNORE if we've decided the remote
9881 * won't cope with it, since we wouldn't bother sending it if
9882 * asked anyway. */
9883 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 9884 ADD_SPECIALS(ssh1_ignore_special);
125105d1 9885 } else if (ssh->version == 2) {
cf6ddb95 9886 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
9887 ADD_SPECIALS(ssh2_ignore_special);
9888 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
9889 ADD_SPECIALS(ssh2_rekey_special);
62638676 9890 if (ssh->mainchan)
9891 ADD_SPECIALS(ssh2_session_specials);
9892 } /* else we're not ready yet */
9893
9894 if (i) {
9895 ADD_SPECIALS(specials_end);
9896 return ssh_specials;
9897 } else {
125105d1 9898 return NULL;
62638676 9899 }
9900#undef ADD_SPECIALS
125105d1 9901}
9902
9903/*
86dc445a 9904 * Send special codes. TS_EOF is useful for `plink', so you
6abbf9e3 9905 * can send an EOF and collect resulting output (e.g. `plink
9906 * hostname sort').
374330e2 9907 */
51470298 9908static void ssh_special(void *handle, Telnet_Special code)
32874aea 9909{
51470298 9910 Ssh ssh = (Ssh) handle;
ff3187f6 9911 struct Packet *pktout;
51470298 9912
6abbf9e3 9913 if (code == TS_EOF) {
51470298 9914 if (ssh->state != SSH_STATE_SESSION) {
32874aea 9915 /*
9916 * Buffer the EOF in case we are pre-SESSION, so we can
9917 * send it as soon as we reach SESSION.
9918 */
9919 if (code == TS_EOF)
51470298 9920 ssh->eof_needed = TRUE;
32874aea 9921 return;
9922 }
51470298 9923 if (ssh->version == 1) {
9924 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 9925 } else if (ssh->mainchan) {
bc06669b 9926 sshfwd_write_eof(ssh->mainchan);
00a0b113 9927 ssh->send_ok = 0; /* now stop trying to read from stdin */
32874aea 9928 }
9929 logevent("Sent EOF message");
125105d1 9930 } else if (code == TS_PING || code == TS_NOP) {
51470298 9931 if (ssh->state == SSH_STATE_CLOSED
9932 || ssh->state == SSH_STATE_PREPACKET) return;
9933 if (ssh->version == 1) {
9934 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9935 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 9936 } else {
cf6ddb95 9937 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
9938 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
9939 ssh2_pkt_addstring_start(pktout);
9940 ssh2_pkt_send_noqueue(ssh, pktout);
9941 }
32874aea 9942 }
9442dd57 9943 } else if (code == TS_REKEY) {
9944 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 9945 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 9946 }
125105d1 9947 } else if (code == TS_BRK) {
9948 if (ssh->state == SSH_STATE_CLOSED
9949 || ssh->state == SSH_STATE_PREPACKET) return;
9950 if (ssh->version == 1) {
2e85c969 9951 logevent("Unable to send BREAK signal in SSH-1");
0ed48730 9952 } else if (ssh->mainchan) {
ff3187f6 9953 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9954 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9955 ssh2_pkt_addstring(pktout, "break");
9956 ssh2_pkt_addbool(pktout, 0);
9957 ssh2_pkt_adduint32(pktout, 0); /* default break length */
9958 ssh2_pkt_send(ssh, pktout);
125105d1 9959 }
6abbf9e3 9960 } else {
6f2d0cde 9961 /* Is is a POSIX signal? */
9962 char *signame = NULL;
9963 if (code == TS_SIGABRT) signame = "ABRT";
9964 if (code == TS_SIGALRM) signame = "ALRM";
9965 if (code == TS_SIGFPE) signame = "FPE";
9966 if (code == TS_SIGHUP) signame = "HUP";
9967 if (code == TS_SIGILL) signame = "ILL";
9968 if (code == TS_SIGINT) signame = "INT";
9969 if (code == TS_SIGKILL) signame = "KILL";
9970 if (code == TS_SIGPIPE) signame = "PIPE";
9971 if (code == TS_SIGQUIT) signame = "QUIT";
9972 if (code == TS_SIGSEGV) signame = "SEGV";
9973 if (code == TS_SIGTERM) signame = "TERM";
9974 if (code == TS_SIGUSR1) signame = "USR1";
9975 if (code == TS_SIGUSR2) signame = "USR2";
9976 /* The SSH-2 protocol does in principle support arbitrary named
9977 * signals, including signame@domain, but we don't support those. */
9978 if (signame) {
9979 /* It's a signal. */
9980 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 9981 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9982 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9983 ssh2_pkt_addstring(pktout, "signal");
9984 ssh2_pkt_addbool(pktout, 0);
9985 ssh2_pkt_addstring(pktout, signame);
9986 ssh2_pkt_send(ssh, pktout);
6f2d0cde 9987 logeventf(ssh, "Sent signal SIG%s", signame);
9988 }
9989 } else {
9990 /* Never heard of it. Do nothing */
9991 }
6abbf9e3 9992 }
374330e2 9993}
9994
51470298 9995void *new_sock_channel(void *handle, Socket s)
d74d141c 9996{
51470298 9997 Ssh ssh = (Ssh) handle;
d74d141c 9998 struct ssh_channel *c;
3d88e64d 9999 c = snew(struct ssh_channel);
d74d141c 10000
70c0cbe1 10001 c->ssh = ssh;
10002 ssh2_channel_init(c);
10003 c->halfopen = TRUE;
10004 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10005 c->u.pfd.s = s;
10006 add234(ssh->channels, c);
d74d141c 10007 return c;
10008}
10009
5471d09a 10010/*
10011 * This is called when stdout/stderr (the entity to which
10012 * from_backend sends data) manages to clear some backlog.
10013 */
ae9ae89f 10014static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 10015{
51470298 10016 Ssh ssh = (Ssh) handle;
ff68564b 10017 int buflimit;
10018
51470298 10019 if (ssh->version == 1) {
10020 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10021 ssh->v1_stdout_throttling = 0;
ff68564b 10022 ssh_throttle_conn(ssh, -1);
5471d09a 10023 }
10024 } else {
ff68564b 10025 if (ssh->mainchan) {
ab87bf1d 10026 ssh2_set_window(ssh->mainchan,
ff68564b 10027 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10028 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
4a693cfc 10029 if (conf_get_int(ssh->conf, CONF_ssh_simple))
ff68564b 10030 buflimit = 0;
10031 else
10032 buflimit = ssh->mainchan->v.v2.locmaxwin;
10033 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10034 ssh->mainchan->throttling_conn = 0;
10035 ssh_throttle_conn(ssh, -1);
10036 }
10037 }
5471d09a 10038 }
10039}
10040
6b78788a 10041void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 10042{
10043 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 10044 Ssh ssh = c->ssh;
ff3187f6 10045 struct Packet *pktout;
d74d141c 10046
57356d63 10047 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 10048
51470298 10049 if (ssh->version == 1) {
10050 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 10051 PKT_INT, c->localid,
10052 PKT_STR, hostname,
10053 PKT_INT, port,
31fb1866 10054 /* PKT_STR, <org:orgport>, */
bc240b21 10055 PKT_END);
10056 } else {
ff3187f6 10057 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
10058 ssh2_pkt_addstring(pktout, "direct-tcpip");
10059 ssh2_pkt_adduint32(pktout, c->localid);
ff3187f6 10060 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 10061 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 10062 ssh2_pkt_addstring(pktout, hostname);
10063 ssh2_pkt_adduint32(pktout, port);
bc240b21 10064 /*
10065 * We make up values for the originator data; partly it's
10066 * too much hassle to keep track, and partly I'm not
10067 * convinced the server should be told details like that
10068 * about my local network configuration.
1f182589 10069 * The "originator IP address" is syntactically a numeric
10070 * IP address, and some servers (e.g., Tectia) get upset
10071 * if it doesn't match this syntax.
bc240b21 10072 */
1f182589 10073 ssh2_pkt_addstring(pktout, "0.0.0.0");
ff3187f6 10074 ssh2_pkt_adduint32(pktout, 0);
10075 ssh2_pkt_send(ssh, pktout);
bc240b21 10076 }
d74d141c 10077}
10078
6226c939 10079static int ssh_connected(void *handle)
32874aea 10080{
51470298 10081 Ssh ssh = (Ssh) handle;
6226c939 10082 return ssh->s != NULL;
32874aea 10083}
8ccc75b0 10084
51470298 10085static int ssh_sendok(void *handle)
32874aea 10086{
51470298 10087 Ssh ssh = (Ssh) handle;
10088 return ssh->send_ok;
32874aea 10089}
fb09bf1c 10090
51470298 10091static int ssh_ldisc(void *handle, int option)
32874aea 10092{
51470298 10093 Ssh ssh = (Ssh) handle;
32874aea 10094 if (option == LD_ECHO)
51470298 10095 return ssh->echoing;
32874aea 10096 if (option == LD_EDIT)
51470298 10097 return ssh->editing;
0965bee0 10098 return FALSE;
10099}
10100
b9d7bcad 10101static void ssh_provide_ldisc(void *handle, void *ldisc)
10102{
10103 Ssh ssh = (Ssh) handle;
10104 ssh->ldisc = ldisc;
10105}
10106
a8327734 10107static void ssh_provide_logctx(void *handle, void *logctx)
10108{
10109 Ssh ssh = (Ssh) handle;
10110 ssh->logctx = logctx;
10111}
10112
51470298 10113static int ssh_return_exitcode(void *handle)
10114{
10115 Ssh ssh = (Ssh) handle;
3bb2f322 10116 if (ssh->s != NULL)
10117 return -1;
10118 else
3c112d53 10119 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
51470298 10120}
10121
10122/*
f89c3294 10123 * cfg_info for SSH is the currently running version of the
10124 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10125 */
10126static int ssh_cfg_info(void *handle)
10127{
10128 Ssh ssh = (Ssh) handle;
10129 return ssh->version;
10130}
10131
10132/*
51470298 10133 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10134 * that fails. This variable is the means by which scp.c can reach
10135 * into the SSH code and find out which one it got.
10136 */
10137extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 10138{
51470298 10139 Ssh ssh = (Ssh) handle;
10140 return ssh->fallback_cmd;
d8d6c7e5 10141}
10142
374330e2 10143Backend ssh_backend = {
10144 ssh_init,
fabd1805 10145 ssh_free,
86916870 10146 ssh_reconfig,
374330e2 10147 ssh_send,
5471d09a 10148 ssh_sendbuffer,
374330e2 10149 ssh_size,
4017be6d 10150 ssh_special,
125105d1 10151 ssh_get_specials,
6226c939 10152 ssh_connected,
d8d6c7e5 10153 ssh_return_exitcode,
97db3be4 10154 ssh_sendok,
0965bee0 10155 ssh_ldisc,
b9d7bcad 10156 ssh_provide_ldisc,
a8327734 10157 ssh_provide_logctx,
5471d09a 10158 ssh_unthrottle,
f89c3294 10159 ssh_cfg_info,
9e164d82 10160 "ssh",
10161 PROT_SSH,
97db3be4 10162 22
bc240b21 10163};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator