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Set cfg.ssh_simple if there are no forwardings.
[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"
374330e2 15
16#ifndef FALSE
17#define FALSE 0
18#endif
19#ifndef TRUE
20#define TRUE 1
21#endif
22
32874aea 23#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
24#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
25#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
26#define SSH1_CMSG_USER 4 /* 0x4 */
27#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
28#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
29#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
30#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
31#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
32#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
33#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
34#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
35#define SSH1_SMSG_SUCCESS 14 /* 0xe */
36#define SSH1_SMSG_FAILURE 15 /* 0xf */
37#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
38#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
39#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
40#define SSH1_CMSG_EOF 19 /* 0x13 */
41#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
42#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
43#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
44#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
45#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
46#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
47#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
48#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
49#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
50#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
51#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
52#define SSH1_MSG_IGNORE 32 /* 0x20 */
53#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
54#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
55#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
56#define SSH1_MSG_DEBUG 36 /* 0x24 */
57#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
58#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
59#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
60#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
61#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
62#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
63#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
64
8f9e3231 65#define SSH1_AUTH_RHOSTS 1 /* 0x1 */
66#define SSH1_AUTH_RSA 2 /* 0x2 */
67#define SSH1_AUTH_PASSWORD 3 /* 0x3 */
68#define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */
32874aea 69#define SSH1_AUTH_TIS 5 /* 0x5 */
70#define SSH1_AUTH_CCARD 16 /* 0x10 */
71
72#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 73/* Mask for protoflags we will echo back to server if seen */
32874aea 74#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
75
76#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
77#define SSH2_MSG_IGNORE 2 /* 0x2 */
78#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
79#define SSH2_MSG_DEBUG 4 /* 0x4 */
80#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
81#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
82#define SSH2_MSG_KEXINIT 20 /* 0x14 */
83#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
84#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
85#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
86#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
87#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
88#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
89#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
fae1a71b 90#define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */
91#define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */
92#define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */
32874aea 93#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
94#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
95#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
96#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
97#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
98#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 99#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
100#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 101#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
102#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
103#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
104#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
105#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
106#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
107#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
108#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
109#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
110#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
111#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
112#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
113#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
114#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
115
00db133f 116/*
117 * Packet type contexts, so that ssh2_pkt_type can correctly decode
118 * the ambiguous type numbers back into the correct type strings.
119 */
acab36bc 120typedef enum {
121 SSH2_PKTCTX_NOKEX,
122 SSH2_PKTCTX_DHGROUP,
123 SSH2_PKTCTX_DHGEX,
124 SSH2_PKTCTX_RSAKEX
125} Pkt_KCtx;
126typedef enum {
127 SSH2_PKTCTX_NOAUTH,
128 SSH2_PKTCTX_PUBLICKEY,
129 SSH2_PKTCTX_PASSWORD,
130 SSH2_PKTCTX_KBDINTER
131} Pkt_ACtx;
00db133f 132
32874aea 133#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
134#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
135#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
136#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
137#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
138#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
139#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
140#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
141#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
142#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
143#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
144#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
145#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
146#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
147#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 148
149static const char *const ssh2_disconnect_reasons[] = {
150 NULL,
afb4d0dc 151 "host not allowed to connect",
152 "protocol error",
153 "key exchange failed",
154 "host authentication failed",
1da38d29 155 "MAC error",
afb4d0dc 156 "compression error",
157 "service not available",
158 "protocol version not supported",
159 "host key not verifiable",
160 "connection lost",
161 "by application",
162 "too many connections",
163 "auth cancelled by user",
164 "no more auth methods available",
165 "illegal user name",
38c4a8da 166};
9005f3ba 167
32874aea 168#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
169#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
170#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
171#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 172
32874aea 173#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 174
7d503c31 175/*
176 * Various remote-bug flags.
177 */
178#define BUG_CHOKES_ON_SSH1_IGNORE 1
179#define BUG_SSH2_HMAC 2
bd358db1 180#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 181#define BUG_CHOKES_ON_RSA 8
1dd353b5 182#define BUG_SSH2_RSA_PADDING 16
088bde77 183#define BUG_SSH2_DERIVEKEY 32
f382c87d 184#define BUG_SSH2_REKEY 64
dda87a28 185#define BUG_SSH2_PK_SESSIONID 128
bd358db1 186
c6ccd5c2 187/*
188 * Codes for terminal modes.
189 * Most of these are the same in SSH-1 and SSH-2.
7646c432 190 * This list is derived from RFC 4254 and
c6ccd5c2 191 * SSH-1 RFC-1.2.31.
192 */
193static const struct {
194 const char* const mode;
195 int opcode;
196 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
197} ssh_ttymodes[] = {
198 /* "V" prefix discarded for special characters relative to SSH specs */
199 { "INTR", 1, TTY_OP_CHAR },
200 { "QUIT", 2, TTY_OP_CHAR },
201 { "ERASE", 3, TTY_OP_CHAR },
202 { "KILL", 4, TTY_OP_CHAR },
203 { "EOF", 5, TTY_OP_CHAR },
204 { "EOL", 6, TTY_OP_CHAR },
205 { "EOL2", 7, TTY_OP_CHAR },
206 { "START", 8, TTY_OP_CHAR },
207 { "STOP", 9, TTY_OP_CHAR },
208 { "SUSP", 10, TTY_OP_CHAR },
209 { "DSUSP", 11, TTY_OP_CHAR },
210 { "REPRINT", 12, TTY_OP_CHAR },
211 { "WERASE", 13, TTY_OP_CHAR },
212 { "LNEXT", 14, TTY_OP_CHAR },
213 { "FLUSH", 15, TTY_OP_CHAR },
214 { "SWTCH", 16, TTY_OP_CHAR },
215 { "STATUS", 17, TTY_OP_CHAR },
216 { "DISCARD", 18, TTY_OP_CHAR },
217 { "IGNPAR", 30, TTY_OP_BOOL },
218 { "PARMRK", 31, TTY_OP_BOOL },
219 { "INPCK", 32, TTY_OP_BOOL },
220 { "ISTRIP", 33, TTY_OP_BOOL },
221 { "INLCR", 34, TTY_OP_BOOL },
222 { "IGNCR", 35, TTY_OP_BOOL },
223 { "ICRNL", 36, TTY_OP_BOOL },
224 { "IUCLC", 37, TTY_OP_BOOL },
225 { "IXON", 38, TTY_OP_BOOL },
226 { "IXANY", 39, TTY_OP_BOOL },
227 { "IXOFF", 40, TTY_OP_BOOL },
228 { "IMAXBEL", 41, TTY_OP_BOOL },
229 { "ISIG", 50, TTY_OP_BOOL },
230 { "ICANON", 51, TTY_OP_BOOL },
231 { "XCASE", 52, TTY_OP_BOOL },
232 { "ECHO", 53, TTY_OP_BOOL },
233 { "ECHOE", 54, TTY_OP_BOOL },
234 { "ECHOK", 55, TTY_OP_BOOL },
235 { "ECHONL", 56, TTY_OP_BOOL },
236 { "NOFLSH", 57, TTY_OP_BOOL },
237 { "TOSTOP", 58, TTY_OP_BOOL },
238 { "IEXTEN", 59, TTY_OP_BOOL },
239 { "ECHOCTL", 60, TTY_OP_BOOL },
240 { "ECHOKE", 61, TTY_OP_BOOL },
241 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
242 { "OPOST", 70, TTY_OP_BOOL },
243 { "OLCUC", 71, TTY_OP_BOOL },
244 { "ONLCR", 72, TTY_OP_BOOL },
245 { "OCRNL", 73, TTY_OP_BOOL },
246 { "ONOCR", 74, TTY_OP_BOOL },
247 { "ONLRET", 75, TTY_OP_BOOL },
248 { "CS7", 90, TTY_OP_BOOL },
249 { "CS8", 91, TTY_OP_BOOL },
250 { "PARENB", 92, TTY_OP_BOOL },
251 { "PARODD", 93, TTY_OP_BOOL }
252};
253
254/* Miscellaneous other tty-related constants. */
255#define SSH_TTY_OP_END 0
256/* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
257#define SSH1_TTY_OP_ISPEED 192
258#define SSH1_TTY_OP_OSPEED 193
259#define SSH2_TTY_OP_ISPEED 128
260#define SSH2_TTY_OP_OSPEED 129
261
262/* Helper functions for parsing tty-related config. */
263static unsigned int ssh_tty_parse_specchar(char *s)
264{
265 unsigned int ret;
266 if (*s) {
267 char *next = NULL;
268 ret = ctrlparse(s, &next);
269 if (!next) ret = s[0];
270 } else {
271 ret = 255; /* special value meaning "don't set" */
272 }
273 return ret;
274}
275static unsigned int ssh_tty_parse_boolean(char *s)
276{
277 if (stricmp(s, "yes") == 0 ||
278 stricmp(s, "on") == 0 ||
279 stricmp(s, "true") == 0 ||
280 stricmp(s, "+") == 0)
281 return 1; /* true */
282 else if (stricmp(s, "no") == 0 ||
283 stricmp(s, "off") == 0 ||
284 stricmp(s, "false") == 0 ||
285 stricmp(s, "-") == 0)
286 return 0; /* false */
287 else
288 return (atoi(s) != 0);
289}
290
00db133f 291#define translate(x) if (type == x) return #x
acab36bc 292#define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
293#define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
ae9ae89f 294static char *ssh1_pkt_type(int type)
00db133f 295{
296 translate(SSH1_MSG_DISCONNECT);
297 translate(SSH1_SMSG_PUBLIC_KEY);
298 translate(SSH1_CMSG_SESSION_KEY);
299 translate(SSH1_CMSG_USER);
300 translate(SSH1_CMSG_AUTH_RSA);
301 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
302 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
303 translate(SSH1_CMSG_AUTH_PASSWORD);
304 translate(SSH1_CMSG_REQUEST_PTY);
305 translate(SSH1_CMSG_WINDOW_SIZE);
306 translate(SSH1_CMSG_EXEC_SHELL);
307 translate(SSH1_CMSG_EXEC_CMD);
308 translate(SSH1_SMSG_SUCCESS);
309 translate(SSH1_SMSG_FAILURE);
310 translate(SSH1_CMSG_STDIN_DATA);
311 translate(SSH1_SMSG_STDOUT_DATA);
312 translate(SSH1_SMSG_STDERR_DATA);
313 translate(SSH1_CMSG_EOF);
314 translate(SSH1_SMSG_EXIT_STATUS);
315 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
316 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
317 translate(SSH1_MSG_CHANNEL_DATA);
318 translate(SSH1_MSG_CHANNEL_CLOSE);
319 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
320 translate(SSH1_SMSG_X11_OPEN);
321 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
322 translate(SSH1_MSG_PORT_OPEN);
323 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
324 translate(SSH1_SMSG_AGENT_OPEN);
325 translate(SSH1_MSG_IGNORE);
326 translate(SSH1_CMSG_EXIT_CONFIRMATION);
327 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
328 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
329 translate(SSH1_MSG_DEBUG);
330 translate(SSH1_CMSG_REQUEST_COMPRESSION);
331 translate(SSH1_CMSG_AUTH_TIS);
332 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
333 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
334 translate(SSH1_CMSG_AUTH_CCARD);
335 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
336 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
337 return "unknown";
338}
acab36bc 339static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
00db133f 340{
341 translate(SSH2_MSG_DISCONNECT);
342 translate(SSH2_MSG_IGNORE);
343 translate(SSH2_MSG_UNIMPLEMENTED);
344 translate(SSH2_MSG_DEBUG);
345 translate(SSH2_MSG_SERVICE_REQUEST);
346 translate(SSH2_MSG_SERVICE_ACCEPT);
347 translate(SSH2_MSG_KEXINIT);
348 translate(SSH2_MSG_NEWKEYS);
acab36bc 349 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
350 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
351 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
352 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
353 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
354 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
355 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
356 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
357 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
00db133f 358 translate(SSH2_MSG_USERAUTH_REQUEST);
359 translate(SSH2_MSG_USERAUTH_FAILURE);
360 translate(SSH2_MSG_USERAUTH_SUCCESS);
361 translate(SSH2_MSG_USERAUTH_BANNER);
acab36bc 362 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
363 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
364 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
365 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
00db133f 366 translate(SSH2_MSG_GLOBAL_REQUEST);
367 translate(SSH2_MSG_REQUEST_SUCCESS);
368 translate(SSH2_MSG_REQUEST_FAILURE);
369 translate(SSH2_MSG_CHANNEL_OPEN);
370 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
371 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
372 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
373 translate(SSH2_MSG_CHANNEL_DATA);
374 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
375 translate(SSH2_MSG_CHANNEL_EOF);
376 translate(SSH2_MSG_CHANNEL_CLOSE);
377 translate(SSH2_MSG_CHANNEL_REQUEST);
378 translate(SSH2_MSG_CHANNEL_SUCCESS);
379 translate(SSH2_MSG_CHANNEL_FAILURE);
380 return "unknown";
381}
382#undef translate
383#undef translatec
7d503c31 384
9a10ecf4 385/* Enumeration values for fields in SSH-1 packets */
386enum {
387 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
388 /* These values are for communicating relevant semantics of
389 * fields to the packet logging code. */
390 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
391};
972a41c8 392
acddebd9 393/*
394 * Coroutine mechanics for the sillier bits of the code. If these
395 * macros look impenetrable to you, you might find it helpful to
396 * read
397 *
398 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
399 *
400 * which explains the theory behind these macros.
b624d1e6 401 *
402 * In particular, if you are getting `case expression not constant'
403 * errors when building with MS Visual Studio, this is because MS's
404 * Edit and Continue debugging feature causes their compiler to
405 * violate ANSI C. To disable Edit and Continue debugging:
406 *
407 * - right-click ssh.c in the FileView
408 * - click Settings
409 * - select the C/C++ tab and the General category
410 * - under `Debug info:', select anything _other_ than `Program
411 * Database for Edit and Continue'.
acddebd9 412 */
51470298 413#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
414#define crState(t) \
415 struct t *s; \
3d88e64d 416 if (!ssh->t) ssh->t = snew(struct t); \
51470298 417 s = ssh->t;
418#define crFinish(z) } *crLine = 0; return (z); }
419#define crFinishV } *crLine = 0; return; }
374330e2 420#define crReturn(z) \
421 do {\
51470298 422 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 423 } while (0)
424#define crReturnV \
425 do {\
51470298 426 *crLine=__LINE__; return; case __LINE__:;\
374330e2 427 } while (0)
51470298 428#define crStop(z) do{ *crLine = 0; return (z); }while(0)
429#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 430#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 431#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 432
51470298 433typedef struct ssh_tag *Ssh;
ff3187f6 434struct Packet;
435
dacd8872 436static struct Packet *ssh1_pkt_init(int pkt_type);
ff3187f6 437static struct Packet *ssh2_pkt_init(int pkt_type);
dacd8872 438static void ssh_pkt_ensure(struct Packet *, int length);
439static void ssh_pkt_adddata(struct Packet *, void *data, int len);
440static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
ff3187f6 441static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
dacd8872 442static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
443static void ssh_pkt_addstring_start(struct Packet *);
444static void ssh_pkt_addstring_str(struct Packet *, char *data);
445static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
446static void ssh_pkt_addstring(struct Packet *, char *data);
d8baa528 447static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
dacd8872 448static void ssh1_pkt_addmp(struct Packet *, Bignum b);
ff3187f6 449static void ssh2_pkt_addmp(struct Packet *, Bignum b);
450static int ssh2_pkt_construct(Ssh, struct Packet *);
451static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 452static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 453static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
454 struct Packet *pktin);
455static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
456 struct Packet *pktin);
3d63ca2e 457
5471d09a 458/*
459 * Buffer management constants. There are several of these for
460 * various different purposes:
461 *
462 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
463 * on a local data stream before we throttle the whole SSH
2e85c969 464 * connection (in SSH-1 only). Throttling the whole connection is
5471d09a 465 * pretty drastic so we set this high in the hope it won't
466 * happen very often.
467 *
468 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
469 * on the SSH connection itself before we defensively throttle
470 * _all_ local data streams. This is pretty drastic too (though
2e85c969 471 * thankfully unlikely in SSH-2 since the window mechanism should
5471d09a 472 * ensure that the server never has any need to throttle its end
473 * of the connection), so we set this high as well.
474 *
2e85c969 475 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
5471d09a 476 * channels.
9b53e9b8 477 *
478 * - OUR_V2_BIGWIN is the window size we advertise for the only
3361b80a 479 * channel in a simple connection. It must be <= INT_MAX.
5471d09a 480 */
481
482#define SSH1_BUFFER_LIMIT 32768
483#define SSH_MAX_BACKLOG 32768
484#define OUR_V2_WINSIZE 16384
3361b80a 485#define OUR_V2_BIGWIN 0x7fffffff
954d5c5a 486#define OUR_V2_MAXPKT 0x4000UL
d74d141c 487
edd0cb8a 488/* Maximum length of passwords/passphrases (arbitrary) */
489#define SSH_MAX_PASSWORD_LEN 100
490
85cc02bb 491const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 492
8b2715b2 493const static struct ssh_mac *macs[] = {
6668a75e 494 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
32874aea 495};
8b2715b2 496const static struct ssh_mac *buggymacs[] = {
6668a75e 497 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
32874aea 498};
e5574168 499
5366aed8 500static void *ssh_comp_none_init(void)
501{
502 return NULL;
503}
504static void ssh_comp_none_cleanup(void *handle)
32874aea 505{
506}
5366aed8 507static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 508 unsigned char **outblock, int *outlen)
509{
510 return 0;
511}
5366aed8 512static int ssh_comp_none_disable(void *handle)
32874aea 513{
4ba9b64b 514 return 0;
515}
57476f6b 516const static struct ssh_compress ssh_comp_none = {
4ba9b64b 517 "none",
5366aed8 518 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
519 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
520 ssh_comp_none_disable, NULL
e5574168 521};
4ba9b64b 522extern const struct ssh_compress ssh_zlib;
523const static struct ssh_compress *compressions[] = {
32874aea 524 &ssh_zlib, &ssh_comp_none
525};
374330e2 526
32874aea 527enum { /* channel types */
783415f8 528 CHAN_MAINSESSION,
529 CHAN_X11,
530 CHAN_AGENT,
bc240b21 531 CHAN_SOCKDATA,
532 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 533};
534
dacbd0e8 535/*
0e443c99 536 * little structure to keep track of outstanding WINDOW_ADJUSTs
537 */
538struct winadj {
539 struct winadj *next;
540 unsigned size;
541};
542
543/*
dacbd0e8 544 * 2-3-4 tree storing channels.
545 */
546struct ssh_channel {
51470298 547 Ssh ssh; /* pointer back to main context */
d211621f 548 unsigned remoteid, localid;
dacbd0e8 549 int type;
64d6ff88 550 /* True if we opened this channel but server hasn't confirmed. */
551 int halfopen;
0357890f 552 /*
2e85c969 553 * In SSH-1, this value contains four bits:
0357890f 554 *
555 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
556 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
557 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
558 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
559 *
560 * A channel is completely finished with when all four bits are set.
561 */
dacbd0e8 562 int closes;
5471d09a 563 union {
564 struct ssh1_data_channel {
565 int throttling;
566 } v1;
567 struct ssh2_data_channel {
568 bufchain outbuffer;
569 unsigned remwindow, remmaxpkt;
467e064d 570 /* locwindow is signed so we can cope with excess data. */
9b53e9b8 571 int locwindow, locmaxwin;
0e443c99 572 /*
573 * remlocwin is the amount of local window that we think
574 * the remote end had available to it after it sent the
575 * last data packet or window adjust ack.
576 */
577 int remlocwin;
578 /*
579 * These store the list of window adjusts that haven't
580 * been acked.
581 */
582 struct winadj *winadj_head, *winadj_tail;
583 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
5471d09a 584 } v2;
585 } v;
dacbd0e8 586 union {
32874aea 587 struct ssh_agent_channel {
588 unsigned char *message;
589 unsigned char msglen[4];
a03c9f9c 590 unsigned lensofar, totallen;
32874aea 591 } a;
592 struct ssh_x11_channel {
593 Socket s;
594 } x11;
d74d141c 595 struct ssh_pfd_channel {
596 Socket s;
597 } pfd;
dacbd0e8 598 } u;
599};
57476f6b 600
d74d141c 601/*
2e85c969 602 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
603 * use this structure in different ways, reflecting SSH-2's
bc240b21 604 * altogether saner approach to port forwarding.
605 *
2e85c969 606 * In SSH-1, you arrange a remote forwarding by sending the server
bc240b21 607 * the remote port number, and the local destination host:port.
608 * When a connection comes in, the server sends you back that
609 * host:port pair, and you connect to it. This is a ready-made
610 * security hole if you're not on the ball: a malicious server
611 * could send you back _any_ host:port pair, so if you trustingly
612 * connect to the address it gives you then you've just opened the
613 * entire inside of your corporate network just by connecting
614 * through it to a dodgy SSH server. Hence, we must store a list of
615 * host:port pairs we _are_ trying to forward to, and reject a
616 * connection request from the server if it's not in the list.
617 *
2e85c969 618 * In SSH-2, each side of the connection minds its own business and
bc240b21 619 * doesn't send unnecessary information to the other. You arrange a
620 * remote forwarding by sending the server just the remote port
621 * number. When a connection comes in, the server tells you which
622 * of its ports was connected to; and _you_ have to remember what
623 * local host:port pair went with that port number.
624 *
2e85c969 625 * Hence, in SSH-1 this structure is indexed by destination
626 * host:port pair, whereas in SSH-2 it is indexed by source port.
d74d141c 627 */
fda2feb1 628struct ssh_portfwd; /* forward declaration */
629
d74d141c 630struct ssh_rportfwd {
bc240b21 631 unsigned sport, dport;
632 char dhost[256];
06fadff5 633 char *sportdesc;
fda2feb1 634 struct ssh_portfwd *pfrec;
d74d141c 635};
fda2feb1 636#define free_rportfwd(pf) ( \
637 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
638
639/*
640 * Separately to the rportfwd tree (which is for looking up port
641 * open requests from the server), a tree of _these_ structures is
642 * used to keep track of all the currently open port forwardings,
643 * so that we can reconfigure in mid-session if the user requests
644 * it.
645 */
646struct ssh_portfwd {
84328ddb 647 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 648 int type;
649 unsigned sport, dport;
650 char *saddr, *daddr;
3fe92132 651 char *sserv, *dserv;
fda2feb1 652 struct ssh_rportfwd *remote;
05581745 653 int addressfamily;
fda2feb1 654 void *local;
655};
656#define free_portfwd(pf) ( \
3fe92132 657 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
658 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 659
57476f6b 660struct Packet {
dacd8872 661 long length; /* length of `data' actually used */
662 long forcepad; /* SSH-2: force padding to at least this length */
663 int type; /* only used for incoming packets */
664 unsigned long sequence; /* SSH-2 incoming sequence number */
665 unsigned char *data; /* allocated storage */
666 unsigned char *body; /* offset of payload within `data' */
667 long savedpos; /* temporary index into `data' (for strings) */
668 long maxlen; /* amount of storage allocated for `data' */
669 long encrypted_len; /* for SSH-2 total-size counting */
ff3187f6 670
671 /*
672 * State associated with packet logging
673 */
674 int logmode;
675 int nblanks;
676 struct logblank_t *blanks;
57476f6b 677};
678
1c1a7262 679static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 680 struct Packet *pktin);
1c1a7262 681static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 682 struct Packet *pktin);
b09eaa88 683static void ssh1_protocol_setup(Ssh ssh);
684static void ssh2_protocol_setup(Ssh ssh);
51470298 685static void ssh_size(void *handle, int width, int height);
686static void ssh_special(void *handle, Telnet_Special);
5471d09a 687static int ssh2_try_send(struct ssh_channel *c);
51470298 688static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
689static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
9fca3f8c 690static void ssh2_set_window(struct ssh_channel *c, int newwin);
51470298 691static int ssh_sendbuffer(void *handle);
ac934965 692static int ssh_do_close(Ssh ssh, int notify_exit);
ff3187f6 693static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
694static int ssh2_pkt_getbool(struct Packet *pkt);
695static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 696static void ssh2_timer(void *ctx, long now);
1c1a7262 697static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
9442dd57 698 struct Packet *pktin);
57476f6b 699
51470298 700struct rdpkt1_state_tag {
57476f6b 701 long len, pad, biglen, to_read;
702 unsigned long realcrc, gotcrc;
703 unsigned char *p;
704 int i;
705 int chunk;
ff3187f6 706 struct Packet *pktin;
51470298 707};
57476f6b 708
51470298 709struct rdpkt2_state_tag {
960e736a 710 long len, pad, payload, packetlen, maclen;
711 int i;
712 int cipherblk;
713 unsigned long incoming_sequence;
ff3187f6 714 struct Packet *pktin;
51470298 715};
716
b09eaa88 717typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 718typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
719
720struct queued_handler;
721struct queued_handler {
722 int msg1, msg2;
723 chandler_fn_t handler;
724 void *ctx;
725 struct queued_handler *next;
726};
b09eaa88 727
51470298 728struct ssh_tag {
729 const struct plug_function_table *fn;
730 /* the above field _must_ be first in the structure */
731
4320baf7 732 char *v_c, *v_s;
b672f405 733 void *exhash;
51470298 734
735 Socket s;
736
b9d7bcad 737 void *ldisc;
a8327734 738 void *logctx;
b9d7bcad 739
51470298 740 unsigned char session_key[32];
741 int v1_compressing;
742 int v1_remote_protoflags;
743 int v1_local_protoflags;
744 int agentfwd_enabled;
745 int X11_fwd_enabled;
746 int remote_bugs;
747 const struct ssh_cipher *cipher;
371e569c 748 void *v1_cipher_ctx;
0183b242 749 void *crcda_ctx;
51470298 750 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 751 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 752 const struct ssh_mac *csmac, *scmac;
e0e1a00d 753 void *cs_mac_ctx, *sc_mac_ctx;
51470298 754 const struct ssh_compress *cscomp, *sccomp;
5366aed8 755 void *cs_comp_ctx, *sc_comp_ctx;
51470298 756 const struct ssh_kex *kex;
757 const struct ssh_signkey *hostkey;
754c0df9 758 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
b672f405 759 int v2_session_id_len;
27cd7fc2 760 void *kex_ctx;
51470298 761
762 char *savedhost;
763 int savedport;
764 int send_ok;
765 int echoing, editing;
766
767 void *frontend;
768
db219738 769 int ospeed, ispeed; /* temporaries */
51470298 770 int term_width, term_height;
771
772 tree234 *channels; /* indexed by local id */
773 struct ssh_channel *mainchan; /* primary session channel */
feb02b4e 774 int ncmode; /* is primary channel direct-tcpip? */
51470298 775 int exitcode;
ac934965 776 int close_expected;
9e296bfa 777 int clean_exit;
51470298 778
fda2feb1 779 tree234 *rportfwds, *portfwds;
51470298 780
781 enum {
782 SSH_STATE_PREPACKET,
783 SSH_STATE_BEFORE_SIZE,
784 SSH_STATE_INTERMED,
785 SSH_STATE_SESSION,
786 SSH_STATE_CLOSED
787 } state;
788
789 int size_needed, eof_needed;
790
590f6a5f 791 struct Packet **queue;
792 int queuelen, queuesize;
793 int queueing;
51470298 794 unsigned char *deferred_send_data;
795 int deferred_len, deferred_size;
796
797 /*
798 * Gross hack: pscp will try to start SFTP but fall back to
799 * scp1 if that fails. This variable is the means by which
800 * scp.c can reach into the SSH code and find out which one it
801 * got.
802 */
803 int fallback_cmd;
804
6bbce591 805 bufchain banner; /* accumulates banners during do_ssh2_authconn */
51470298 806
acab36bc 807 Pkt_KCtx pkt_kctx;
808 Pkt_ACtx pkt_actx;
51470298 809
302121de 810 void *x11auth;
811
51470298 812 int version;
813 int v1_throttle_count;
814 int overall_bufsize;
815 int throttled_all;
816 int v1_stdout_throttling;
a8756193 817 unsigned long v2_outgoing_sequence;
51470298 818
819 int ssh1_rdpkt_crstate;
820 int ssh2_rdpkt_crstate;
821 int do_ssh_init_crstate;
822 int ssh_gotdata_crstate;
51470298 823 int do_ssh1_login_crstate;
b09eaa88 824 int do_ssh1_connection_crstate;
51470298 825 int do_ssh2_transport_crstate;
826 int do_ssh2_authconn_crstate;
827
828 void *do_ssh_init_state;
829 void *do_ssh1_login_state;
830 void *do_ssh2_transport_state;
831 void *do_ssh2_authconn_state;
832
833 struct rdpkt1_state_tag rdpkt1_state;
834 struct rdpkt2_state_tag rdpkt2_state;
835
2e85c969 836 /* SSH-1 and SSH-2 use this for different things, but both use it */
b09eaa88 837 int protocol_initial_phase_done;
838
1c1a7262 839 void (*protocol) (Ssh ssh, void *vin, int inlen,
ff3187f6 840 struct Packet *pkt);
841 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 842
843 /*
844 * We maintain a full _copy_ of a Config structure here, not
845 * merely a pointer to it. That way, when we're passed a new
846 * one for reconfiguration, we can check the differences and
847 * potentially reconfigure port forwardings etc in mid-session.
848 */
849 Config cfg;
839f10db 850
851 /*
3d9449a1 852 * Used to transfer data back from async callbacks.
839f10db 853 */
854 void *agent_response;
855 int agent_response_len;
3d9449a1 856 int user_response;
857
858 /*
859 * The SSH connection can be set as `frozen', meaning we are
860 * not currently accepting incoming data from the network. This
861 * is slightly more serious than setting the _socket_ as
862 * frozen, because we may already have had data passed to us
863 * from the network which we need to delay processing until
864 * after the freeze is lifted, so we also need a bufchain to
865 * store that data.
866 */
867 int frozen;
868 bufchain queued_incoming_data;
b09eaa88 869
870 /*
871 * Dispatch table for packet types that we may have to deal
872 * with at any time.
873 */
874 handler_fn_t packet_dispatch[256];
39934deb 875
876 /*
06fadff5 877 * Queues of one-off handler functions for success/failure
878 * indications from a request.
879 */
880 struct queued_handler *qhead, *qtail;
881
882 /*
39934deb 883 * This module deals with sending keepalives.
884 */
885 Pinger pinger;
9442dd57 886
887 /*
888 * Track incoming and outgoing data sizes and time, for
889 * size-based rekeys.
890 */
891 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 892 unsigned long max_data_size;
9442dd57 893 int kex_in_progress;
e6c1536e 894 long next_rekey, last_rekey;
e13bba36 895 char *deferred_rekey_reason; /* points to STATIC string; don't free */
51470298 896};
960e736a 897
382908ad 898#define logevent(s) logevent(ssh->frontend, s)
a8327734 899
900/* logevent, only printf-formatted. */
cbe2d68f 901static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 902{
903 va_list ap;
57356d63 904 char *buf;
a8327734 905
906 va_start(ap, fmt);
57356d63 907 buf = dupvprintf(fmt, ap);
a8327734 908 va_end(ap);
57356d63 909 logevent(buf);
57356d63 910 sfree(buf);
a8327734 911}
912
6b5cf8b4 913#define bombout(msg) \
914 do { \
915 char *text = dupprintf msg; \
ac934965 916 ssh_do_close(ssh, FALSE); \
6b5cf8b4 917 logevent(text); \
918 connection_fatal(ssh->frontend, "%s", text); \
919 sfree(text); \
920 } while (0)
a8327734 921
9a10ecf4 922/* Functions to leave bits out of the SSH packet log file. */
923
ff3187f6 924static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 925{
926 if (ssh->cfg.logomitpass)
ff3187f6 927 pkt->logmode = blanktype;
9a10ecf4 928}
929
ff3187f6 930static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 931{
932 if (ssh->cfg.logomitdata)
ff3187f6 933 pkt->logmode = blanktype;
9a10ecf4 934}
935
ff3187f6 936static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 937{
ff3187f6 938 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 939}
940
c6ccd5c2 941/* Helper function for common bits of parsing cfg.ttymodes. */
942static void parse_ttymodes(Ssh ssh, char *modes,
943 void (*do_mode)(void *data, char *mode, char *val),
944 void *data)
945{
946 while (*modes) {
947 char *t = strchr(modes, '\t');
948 char *m = snewn(t-modes+1, char);
949 char *val;
950 strncpy(m, modes, t-modes);
951 m[t-modes] = '\0';
952 if (*(t+1) == 'A')
953 val = get_ttymode(ssh->frontend, m);
954 else
955 val = dupstr(t+2);
956 if (val)
957 do_mode(data, m, val);
958 sfree(m);
959 sfree(val);
960 modes += strlen(modes) + 1;
961 }
962}
963
32874aea 964static int ssh_channelcmp(void *av, void *bv)
965{
966 struct ssh_channel *a = (struct ssh_channel *) av;
967 struct ssh_channel *b = (struct ssh_channel *) bv;
968 if (a->localid < b->localid)
969 return -1;
970 if (a->localid > b->localid)
971 return +1;
dacbd0e8 972 return 0;
973}
32874aea 974static int ssh_channelfind(void *av, void *bv)
975{
976 unsigned *a = (unsigned *) av;
977 struct ssh_channel *b = (struct ssh_channel *) bv;
978 if (*a < b->localid)
979 return -1;
980 if (*a > b->localid)
981 return +1;
dacbd0e8 982 return 0;
983}
984
bc240b21 985static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 986{
987 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
988 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
989 int i;
bc240b21 990 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 991 return i < 0 ? -1 : +1;
bc240b21 992 if (a->dport > b->dport)
993 return +1;
994 if (a->dport < b->dport)
995 return -1;
996 return 0;
997}
998
999static int ssh_rportcmp_ssh2(void *av, void *bv)
1000{
1001 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1002 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 1003
bc240b21 1004 if (a->sport > b->sport)
d74d141c 1005 return +1;
bc240b21 1006 if (a->sport < b->sport)
1007 return -1;
d74d141c 1008 return 0;
1009}
1010
fda2feb1 1011/*
1012 * Special form of strcmp which can cope with NULL inputs. NULL is
1013 * defined to sort before even the empty string.
1014 */
1015static int nullstrcmp(const char *a, const char *b)
1016{
1017 if (a == NULL && b == NULL)
1018 return 0;
1019 if (a == NULL)
1020 return -1;
1021 if (b == NULL)
1022 return +1;
1023 return strcmp(a, b);
1024}
1025
1026static int ssh_portcmp(void *av, void *bv)
1027{
1028 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1029 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1030 int i;
1031 if (a->type > b->type)
1032 return +1;
1033 if (a->type < b->type)
1034 return -1;
84328ddb 1035 if (a->addressfamily > b->addressfamily)
1036 return +1;
1037 if (a->addressfamily < b->addressfamily)
1038 return -1;
fda2feb1 1039 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1040 return i < 0 ? -1 : +1;
1041 if (a->sport > b->sport)
1042 return +1;
1043 if (a->sport < b->sport)
1044 return -1;
1045 if (a->type != 'D') {
1046 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1047 return i < 0 ? -1 : +1;
1048 if (a->dport > b->dport)
1049 return +1;
1050 if (a->dport < b->dport)
1051 return -1;
1052 }
1053 return 0;
1054}
1055
51470298 1056static int alloc_channel_id(Ssh ssh)
32874aea 1057{
260f3dec 1058 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1059 unsigned low, high, mid;
d2371c81 1060 int tsize;
1061 struct ssh_channel *c;
1062
1063 /*
1064 * First-fit allocation of channel numbers: always pick the
1065 * lowest unused one. To do this, binary-search using the
1066 * counted B-tree to find the largest channel ID which is in a
1067 * contiguous sequence from the beginning. (Precisely
1068 * everything in that sequence must have ID equal to its tree
1069 * index plus CHANNEL_NUMBER_OFFSET.)
1070 */
51470298 1071 tsize = count234(ssh->channels);
d2371c81 1072
32874aea 1073 low = -1;
1074 high = tsize;
d2371c81 1075 while (high - low > 1) {
1076 mid = (high + low) / 2;
51470298 1077 c = index234(ssh->channels, mid);
d2371c81 1078 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1079 low = mid; /* this one is fine */
1080 else
1081 high = mid; /* this one is past it */
1082 }
1083 /*
1084 * Now low points to either -1, or the tree index of the
1085 * largest ID in the initial sequence.
1086 */
1087 {
1088 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 1089 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 1090 }
1091 return low + 1 + CHANNEL_NUMBER_OFFSET;
1092}
1093
edd0cb8a 1094static void c_write_stderr(int trusted, const char *buf, int len)
1095{
1096 int i;
1097 for (i = 0; i < len; i++)
667deca9 1098 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
edd0cb8a 1099 fputc(buf[i], stderr);
1100}
1101
9fab77dc 1102static void c_write(Ssh ssh, const char *buf, int len)
32874aea 1103{
edd0cb8a 1104 if (flags & FLAG_STDERR)
1105 c_write_stderr(1, buf, len);
1106 else
1107 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 1108}
1109
9fab77dc 1110static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 1111{
edd0cb8a 1112 if (flags & FLAG_STDERR)
1113 c_write_stderr(0, buf, len);
1114 else
1115 from_backend_untrusted(ssh->frontend, buf, len);
a209e957 1116}
1117
9fab77dc 1118static void c_write_str(Ssh ssh, const char *buf)
32874aea 1119{
51470298 1120 c_write(ssh, buf, strlen(buf));
1408a877 1121}
1122
ff3187f6 1123static void ssh_free_packet(struct Packet *pkt)
1124{
1125 sfree(pkt->data);
1126 sfree(pkt);
1127}
1128static struct Packet *ssh_new_packet(void)
1129{
1130 struct Packet *pkt = snew(struct Packet);
1131
dacd8872 1132 pkt->body = pkt->data = NULL;
ff3187f6 1133 pkt->maxlen = 0;
1134 pkt->logmode = PKTLOG_EMIT;
1135 pkt->nblanks = 0;
1136 pkt->blanks = NULL;
1137
1138 return pkt;
1139}
1140
fb09bf1c 1141/*
1142 * Collect incoming data in the incoming packet buffer.
e5574168 1143 * Decipher and verify the packet when it is completely read.
1144 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 1145 * Update the *data and *datalen variables.
ff3187f6 1146 * Return a Packet structure when a packet is completed.
fb09bf1c 1147 */
ff3187f6 1148static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 1149{
51470298 1150 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 1151
51470298 1152 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 1153
ff3187f6 1154 st->pktin = ssh_new_packet();
1155
1156 st->pktin->type = 0;
1157 st->pktin->length = 0;
374330e2 1158
57476f6b 1159 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 1160 while ((*datalen) == 0)
ff3187f6 1161 crReturn(NULL);
57476f6b 1162 st->len = (st->len << 8) + **data;
fb09bf1c 1163 (*data)++, (*datalen)--;
1164 }
374330e2 1165
57476f6b 1166 st->pad = 8 - (st->len % 8);
1167 st->biglen = st->len + st->pad;
ff3187f6 1168 st->pktin->length = st->len - 5;
fb09bf1c 1169
ae0500e5 1170 if (st->biglen < 0) {
1171 bombout(("Extremely large packet length from server suggests"
1172 " data stream corruption"));
ff3187f6 1173 ssh_free_packet(st->pktin);
1174 crStop(NULL);
ae0500e5 1175 }
1176
ff3187f6 1177 st->pktin->maxlen = st->biglen;
1178 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1179
57476f6b 1180 st->to_read = st->biglen;
ff3187f6 1181 st->p = st->pktin->data;
57476f6b 1182 while (st->to_read > 0) {
32874aea 1183 st->chunk = st->to_read;
fb09bf1c 1184 while ((*datalen) == 0)
ff3187f6 1185 crReturn(NULL);
57476f6b 1186 if (st->chunk > (*datalen))
1187 st->chunk = (*datalen);
1188 memcpy(st->p, *data, st->chunk);
1189 *data += st->chunk;
1190 *datalen -= st->chunk;
1191 st->p += st->chunk;
1192 st->to_read -= st->chunk;
fb09bf1c 1193 }
374330e2 1194
ff3187f6 1195 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1196 st->biglen, NULL)) {
6b5cf8b4 1197 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1198 ssh_free_packet(st->pktin);
1199 crStop(NULL);
9a3a93a5 1200 }
1201
51470298 1202 if (ssh->cipher)
ff3187f6 1203 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1204
ff3187f6 1205 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1206 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1207 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1208 bombout(("Incorrect CRC received on packet"));
ff3187f6 1209 ssh_free_packet(st->pktin);
1210 crStop(NULL);
fb09bf1c 1211 }
572f871e 1212
ff3187f6 1213 st->pktin->body = st->pktin->data + st->pad + 1;
1214 st->pktin->savedpos = 0;
4ba9b64b 1215
51470298 1216 if (ssh->v1_compressing) {
4ba9b64b 1217 unsigned char *decompblk;
1218 int decomplen;
36b8d9bb 1219 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1220 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1221 &decompblk, &decomplen)) {
1222 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1223 ssh_free_packet(st->pktin);
1224 crStop(NULL);
36b8d9bb 1225 }
4ba9b64b 1226
ff3187f6 1227 if (st->pktin->maxlen < st->pad + decomplen) {
1228 st->pktin->maxlen = st->pad + decomplen;
1229 st->pktin->data = sresize(st->pktin->data,
1230 st->pktin->maxlen + APIEXTRA,
3d88e64d 1231 unsigned char);
ff3187f6 1232 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1233 }
1234
ff3187f6 1235 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1236 sfree(decompblk);
ff3187f6 1237 st->pktin->length = decomplen - 1;
4ba9b64b 1238 }
1239
ff3187f6 1240 st->pktin->type = st->pktin->body[-1];
00db133f 1241
9a10ecf4 1242 /*
1243 * Log incoming packet, possibly omitting sensitive fields.
1244 */
1245 if (ssh->logctx) {
1246 int nblanks = 0;
1247 struct logblank_t blank;
1248 if (ssh->cfg.logomitdata) {
1249 int do_blank = FALSE, blank_prefix = 0;
1250 /* "Session data" packets - omit the data field */
ff3187f6 1251 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1252 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1253 do_blank = TRUE; blank_prefix = 4;
a2724fba 1254 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1255 do_blank = TRUE; blank_prefix = 8;
9a10ecf4 1256 }
1257 if (do_blank) {
1258 blank.offset = blank_prefix;
ff3187f6 1259 blank.len = st->pktin->length;
9a10ecf4 1260 blank.type = PKTLOG_OMIT;
1261 nblanks = 1;
1262 }
1263 }
a8327734 1264 log_packet(ssh->logctx,
ff3187f6 1265 PKT_INCOMING, st->pktin->type,
1266 ssh1_pkt_type(st->pktin->type),
1267 st->pktin->body, st->pktin->length,
9a10ecf4 1268 nblanks, &blank);
1269 }
00db133f 1270
ff3187f6 1271 crFinish(st->pktin);
fb09bf1c 1272}
1273
ff3187f6 1274static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1275{
51470298 1276 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1277
51470298 1278 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1279
ff3187f6 1280 st->pktin = ssh_new_packet();
1281
1282 st->pktin->type = 0;
1283 st->pktin->length = 0;
51470298 1284 if (ssh->sccipher)
1285 st->cipherblk = ssh->sccipher->blksize;
e5574168 1286 else
32874aea 1287 st->cipherblk = 8;
960e736a 1288 if (st->cipherblk < 8)
32874aea 1289 st->cipherblk = 8;
960e736a 1290
ff3187f6 1291 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1292
1293 /*
1294 * Acquire and decrypt the first block of the packet. This will
1295 * contain the length and padding details.
1296 */
32874aea 1297 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1298 while ((*datalen) == 0)
ff3187f6 1299 crReturn(NULL);
1300 st->pktin->data[st->i] = *(*data)++;
32874aea 1301 (*datalen)--;
e5574168 1302 }
4252c9cc 1303
51470298 1304 if (ssh->sccipher)
371e569c 1305 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1306 st->pktin->data, st->cipherblk);
e5574168 1307
1308 /*
1309 * Now get the length and padding figures.
1310 */
ff3187f6 1311 st->len = GET_32BIT(st->pktin->data);
1312 st->pad = st->pktin->data[4];
e5574168 1313
1314 /*
717dc483 1315 * _Completely_ silly lengths should be stomped on before they
1316 * do us any more damage.
1317 */
cba1e4b5 1318 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1319 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
6b5cf8b4 1320 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1321 ssh_free_packet(st->pktin);
1322 crStop(NULL);
717dc483 1323 }
1324
1325 /*
e5574168 1326 * This enables us to deduce the payload length.
1327 */
960e736a 1328 st->payload = st->len - st->pad - 1;
e5574168 1329
ff3187f6 1330 st->pktin->length = st->payload + 5;
e5574168 1331
1332 /*
1333 * So now we can work out the total packet length.
1334 */
960e736a 1335 st->packetlen = st->len + 4;
51470298 1336 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1337
1338 /*
ff3187f6 1339 * Allocate memory for the rest of the packet.
e5574168 1340 */
ff3187f6 1341 st->pktin->maxlen = st->packetlen + st->maclen;
1342 st->pktin->data = sresize(st->pktin->data,
1343 st->pktin->maxlen + APIEXTRA,
1344 unsigned char);
e5574168 1345
1346 /*
1347 * Read and decrypt the remainder of the packet.
1348 */
32874aea 1349 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1350 st->i++) {
e5574168 1351 while ((*datalen) == 0)
ff3187f6 1352 crReturn(NULL);
1353 st->pktin->data[st->i] = *(*data)++;
32874aea 1354 (*datalen)--;
e5574168 1355 }
1356 /* Decrypt everything _except_ the MAC. */
51470298 1357 if (ssh->sccipher)
371e569c 1358 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1359 st->pktin->data + st->cipherblk,
51470298 1360 st->packetlen - st->cipherblk);
e5574168 1361
9442dd57 1362 st->pktin->encrypted_len = st->packetlen;
1363
e5574168 1364 /*
1365 * Check the MAC.
1366 */
51470298 1367 if (ssh->scmac
ff3187f6 1368 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1369 st->incoming_sequence)) {
6b5cf8b4 1370 bombout(("Incorrect MAC received on packet"));
ff3187f6 1371 ssh_free_packet(st->pktin);
1372 crStop(NULL);
8d5de777 1373 }
b09eaa88 1374
1375 st->pktin->sequence = st->incoming_sequence++;
e5574168 1376
4ba9b64b 1377 /*
1378 * Decompress packet payload.
1379 */
1380 {
1381 unsigned char *newpayload;
1382 int newlen;
51470298 1383 if (ssh->sccomp &&
5366aed8 1384 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1385 st->pktin->data + 5, st->pktin->length - 5,
51470298 1386 &newpayload, &newlen)) {
ff3187f6 1387 if (st->pktin->maxlen < newlen + 5) {
1388 st->pktin->maxlen = newlen + 5;
1389 st->pktin->data = sresize(st->pktin->data,
1390 st->pktin->maxlen + APIEXTRA,
3d88e64d 1391 unsigned char);
4ba9b64b 1392 }
ff3187f6 1393 st->pktin->length = 5 + newlen;
1394 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1395 sfree(newpayload);
4ba9b64b 1396 }
1397 }
1398
ff3187f6 1399 st->pktin->savedpos = 6;
1400 st->pktin->body = st->pktin->data;
1401 st->pktin->type = st->pktin->data[5];
e5574168 1402
9a10ecf4 1403 /*
1404 * Log incoming packet, possibly omitting sensitive fields.
1405 */
1406 if (ssh->logctx) {
1407 int nblanks = 0;
1408 struct logblank_t blank;
1409 if (ssh->cfg.logomitdata) {
1410 int do_blank = FALSE, blank_prefix = 0;
1411 /* "Session data" packets - omit the data field */
ff3187f6 1412 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1413 do_blank = TRUE; blank_prefix = 8;
a2724fba 1414 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1415 do_blank = TRUE; blank_prefix = 12;
9a10ecf4 1416 }
1417 if (do_blank) {
1418 blank.offset = blank_prefix;
ff3187f6 1419 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1420 blank.type = PKTLOG_OMIT;
1421 nblanks = 1;
1422 }
1423 }
ff3187f6 1424 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
acab36bc 1425 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1426 st->pktin->type),
ff3187f6 1427 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1428 nblanks, &blank);
1429 }
00db133f 1430
ff3187f6 1431 crFinish(st->pktin);
e5574168 1432}
1433
dacd8872 1434static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
32874aea 1435{
dacd8872 1436 int pad, biglen, i, pktoffs;
374330e2 1437 unsigned long crc;
fd7a4aad 1438#ifdef __SC__
1439 /*
1440 * XXX various versions of SC (including 8.8.4) screw up the
1441 * register allocation in this function and use the same register
1442 * (D6) for len and as a temporary, with predictable results. The
1443 * following sledgehammer prevents this.
1444 */
1445 volatile
1446#endif
1447 int len;
374330e2 1448
a8327734 1449 if (ssh->logctx)
dacd8872 1450 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1451 ssh1_pkt_type(pkt->data[12]),
1452 pkt->body, pkt->length - (pkt->body - pkt->data),
ff3187f6 1453 pkt->nblanks, pkt->blanks);
1454 sfree(pkt->blanks); pkt->blanks = NULL;
1455 pkt->nblanks = 0;
00db133f 1456
51470298 1457 if (ssh->v1_compressing) {
4ba9b64b 1458 unsigned char *compblk;
1459 int complen;
5366aed8 1460 zlib_compress_block(ssh->cs_comp_ctx,
dacd8872 1461 pkt->data + 12, pkt->length - 12,
4ba9b64b 1462 &compblk, &complen);
48406e6b 1463 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
dacd8872 1464 memcpy(pkt->data + 12, compblk, complen);
dcbde236 1465 sfree(compblk);
dacd8872 1466 pkt->length = complen + 12;
4ba9b64b 1467 }
1468
dacd8872 1469 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1470 pkt->length += 4;
1471 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
32874aea 1472 pad = 8 - (len % 8);
dacd8872 1473 pktoffs = 8 - pad;
1474 biglen = len + pad; /* len(padding+type+data+CRC) */
374330e2 1475
dacd8872 1476 for (i = pktoffs; i < 4+8; i++)
1477 pkt->data[i] = random_byte();
1478 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1479 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1480 PUT_32BIT(pkt->data + pktoffs, len);
374330e2 1481
51470298 1482 if (ssh->cipher)
dacd8872 1483 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1484 pkt->data + pktoffs + 4, biglen);
374330e2 1485
dacd8872 1486 if (offset_p) *offset_p = pktoffs;
1487 return biglen + 4; /* len(length+padding+type+data+CRC) */
39065bed 1488}
1489
bf8a49a1 1490static int s_write(Ssh ssh, void *data, int len)
1491{
ff05dfef 1492 if (ssh->logctx)
1493 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len, 0, NULL);
bf8a49a1 1494 return sk_write(ssh->s, (char *)data, len);
1495}
1496
ff3187f6 1497static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1498{
dacd8872 1499 int len, backlog, offset;
1500 len = s_wrpkt_prepare(ssh, pkt, &offset);
bf8a49a1 1501 backlog = s_write(ssh, pkt->data + offset, len);
5471d09a 1502 if (backlog > SSH_MAX_BACKLOG)
51470298 1503 ssh_throttle_all(ssh, 1, backlog);
dacd8872 1504 ssh_free_packet(pkt);
39065bed 1505}
1506
ff3187f6 1507static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1508{
dacd8872 1509 int len, offset;
1510 len = s_wrpkt_prepare(ssh, pkt, &offset);
51470298 1511 if (ssh->deferred_len + len > ssh->deferred_size) {
1512 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1513 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1514 ssh->deferred_size,
1515 unsigned char);
39065bed 1516 }
dacd8872 1517 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1518 pkt->data + offset, len);
51470298 1519 ssh->deferred_len += len;
dacd8872 1520 ssh_free_packet(pkt);
374330e2 1521}
1522
fb09bf1c 1523/*
dacd8872 1524 * Construct a SSH-1 packet with the specified contents.
1525 * (This all-at-once interface used to be the only one, but now SSH-1
1526 * packets can also be constructed incrementally.)
fb09bf1c 1527 */
dacd8872 1528static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
fb09bf1c 1529{
dacd8872 1530 int argtype;
7cca0d81 1531 Bignum bn;
ff3187f6 1532 struct Packet *pkt;
fb09bf1c 1533
dacd8872 1534 pkt = ssh1_pkt_init(pkttype);
fb09bf1c 1535
dacd8872 1536 while ((argtype = va_arg(ap, int)) != PKT_END) {
1537 unsigned char *argp, argchar;
8a9977e5 1538 char *sargp;
dacd8872 1539 unsigned long argint;
1540 int arglen;
fb09bf1c 1541 switch (argtype) {
9a10ecf4 1542 /* Actual fields in the packet */
fb09bf1c 1543 case PKT_INT:
dacd8872 1544 argint = va_arg(ap, int);
1545 ssh_pkt_adduint32(pkt, argint);
fb09bf1c 1546 break;
1547 case PKT_CHAR:
dacd8872 1548 argchar = (unsigned char) va_arg(ap, int);
1549 ssh_pkt_addbyte(pkt, argchar);
fb09bf1c 1550 break;
1551 case PKT_DATA:
dacd8872 1552 argp = va_arg(ap, unsigned char *);
1553 arglen = va_arg(ap, int);
1554 ssh_pkt_adddata(pkt, argp, arglen);
fb09bf1c 1555 break;
1556 case PKT_STR:
8a9977e5 1557 sargp = va_arg(ap, char *);
1558 ssh_pkt_addstring(pkt, sargp);
fb09bf1c 1559 break;
7cca0d81 1560 case PKT_BIGNUM:
dacd8872 1561 bn = va_arg(ap, Bignum);
1562 ssh1_pkt_addmp(pkt, bn);
9a10ecf4 1563 break;
1564 /* Tokens for modifications to packet logging */
1565 case PKTT_PASSWORD:
ff3187f6 1566 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1567 break;
1568 case PKTT_DATA:
ff3187f6 1569 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1570 break;
9a10ecf4 1571 case PKTT_OTHER:
ff3187f6 1572 end_log_omission(ssh, pkt);
9a10ecf4 1573 break;
1574 }
fb09bf1c 1575 }
ff3187f6 1576
1577 return pkt;
39065bed 1578}
fb09bf1c 1579
51470298 1580static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1581{
ff3187f6 1582 struct Packet *pkt;
dacd8872 1583 va_list ap;
1584 va_start(ap, pkttype);
1585 pkt = construct_packet(ssh, pkttype, ap);
1586 va_end(ap);
ff3187f6 1587 s_wrpkt(ssh, pkt);
fb09bf1c 1588}
1589
51470298 1590static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1591{
ff3187f6 1592 struct Packet *pkt;
dacd8872 1593 va_list ap;
1594 va_start(ap, pkttype);
1595 pkt = construct_packet(ssh, pkttype, ap);
1596 va_end(ap);
ff3187f6 1597 s_wrpkt_defer(ssh, pkt);
39065bed 1598}
1599
32874aea 1600static int ssh_versioncmp(char *a, char *b)
1601{
9697bfd2 1602 char *ae, *be;
1603 unsigned long av, bv;
1604
43aa02a7 1605 av = strtoul(a, &ae, 10);
1606 bv = strtoul(b, &be, 10);
32874aea 1607 if (av != bv)
1608 return (av < bv ? -1 : +1);
1609 if (*ae == '.')
1610 ae++;
1611 if (*be == '.')
1612 be++;
43aa02a7 1613 av = strtoul(ae, &ae, 10);
1614 bv = strtoul(be, &be, 10);
32874aea 1615 if (av != bv)
1616 return (av < bv ? -1 : +1);
9697bfd2 1617 return 0;
1618}
1619
e5574168 1620/*
a92dd380 1621 * Utility routines for putting an SSH-protocol `string' and
b672f405 1622 * `uint32' into a hash state.
e5574168 1623 */
b672f405 1624static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
32874aea 1625{
e5574168 1626 unsigned char lenblk[4];
e5574168 1627 PUT_32BIT(lenblk, len);
b672f405 1628 h->bytes(s, lenblk, 4);
1629 h->bytes(s, str, len);
e5574168 1630}
1631
b672f405 1632static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
32874aea 1633{
a92dd380 1634 unsigned char intblk[4];
1635 PUT_32BIT(intblk, i);
b672f405 1636 h->bytes(s, intblk, 4);
a92dd380 1637}
1638
7cca0d81 1639/*
dacd8872 1640 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
7cca0d81 1641 */
dacd8872 1642static void ssh_pkt_ensure(struct Packet *pkt, int length)
32874aea 1643{
ff3187f6 1644 if (pkt->maxlen < length) {
dacd8872 1645 unsigned char *body = pkt->body;
3d71de0b 1646 int offset = body ? body - pkt->data : 0;
ff3187f6 1647 pkt->maxlen = length + 256;
1648 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
dacd8872 1649 if (body) pkt->body = pkt->data + offset;
7cca0d81 1650 }
783415f8 1651}
dacd8872 1652static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1653{
ff3187f6 1654 if (pkt->logmode != PKTLOG_EMIT) {
1655 pkt->nblanks++;
1656 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
dacd8872 1657 assert(pkt->body);
1658 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1659 (pkt->body - pkt->data);
ff3187f6 1660 pkt->blanks[pkt->nblanks-1].len = len;
1661 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1662 }
1663 pkt->length += len;
dacd8872 1664 ssh_pkt_ensure(pkt, pkt->length);
ff3187f6 1665 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1666}
dacd8872 1667static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1668{
dacd8872 1669 ssh_pkt_adddata(pkt, &byte, 1);
7cca0d81 1670}
ff3187f6 1671static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1672{
dacd8872 1673 ssh_pkt_adddata(pkt, &value, 1);
7cca0d81 1674}
dacd8872 1675static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1676{
7cca0d81 1677 unsigned char x[4];
1678 PUT_32BIT(x, value);
dacd8872 1679 ssh_pkt_adddata(pkt, x, 4);
7cca0d81 1680}
dacd8872 1681static void ssh_pkt_addstring_start(struct Packet *pkt)
32874aea 1682{
dacd8872 1683 ssh_pkt_adduint32(pkt, 0);
ff3187f6 1684 pkt->savedpos = pkt->length;
7cca0d81 1685}
dacd8872 1686static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1687{
dacd8872 1688 ssh_pkt_adddata(pkt, data, strlen(data));
ff3187f6 1689 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1690}
dacd8872 1691static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1692{
dacd8872 1693 ssh_pkt_adddata(pkt, data, len);
ff3187f6 1694 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1695}
dacd8872 1696static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1697{
1698 ssh_pkt_addstring_start(pkt);
1699 ssh_pkt_addstring_str(pkt, data);
1700}
1701static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1702{
dacd8872 1703 int len = ssh1_bignum_length(b);
8a9977e5 1704 unsigned char *data = snewn(len, unsigned char);
dacd8872 1705 (void) ssh1_write_bignum(data, b);
1706 ssh_pkt_adddata(pkt, data, len);
1707 sfree(data);
7cca0d81 1708}
d8baa528 1709static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1710{
7cca0d81 1711 unsigned char *p;
32874aea 1712 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1713 p = snewn(n + 1, unsigned char);
7cca0d81 1714 p[0] = 0;
3709bfe9 1715 for (i = 1; i <= n; i++)
32874aea 1716 p[i] = bignum_byte(b, n - i);
7cca0d81 1717 i = 0;
32874aea 1718 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1719 i++;
1720 memmove(p, p + i, n + 1 - i);
1721 *len = n + 1 - i;
7cca0d81 1722 return p;
1723}
ff3187f6 1724static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1725{
7cca0d81 1726 unsigned char *p;
1727 int len;
1728 p = ssh2_mpint_fmt(b, &len);
dacd8872 1729 ssh_pkt_addstring_start(pkt);
1730 ssh_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1731 sfree(p);
7cca0d81 1732}
b185170a 1733
dacd8872 1734static struct Packet *ssh1_pkt_init(int pkt_type)
1735{
1736 struct Packet *pkt = ssh_new_packet();
1737 pkt->length = 4 + 8; /* space for length + max padding */
1738 ssh_pkt_addbyte(pkt, pkt_type);
1739 pkt->body = pkt->data + pkt->length;
1740 return pkt;
1741}
1742
1743/* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1744#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1745#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1746#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1747#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1748#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1749#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1750#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1751#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1752
1753static struct Packet *ssh2_pkt_init(int pkt_type)
1754{
1755 struct Packet *pkt = ssh_new_packet();
3d71de0b 1756 pkt->length = 5; /* space for packet length + padding length */
dacd8872 1757 pkt->forcepad = 0;
1758 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
3d71de0b 1759 pkt->body = pkt->data + pkt->length; /* after packet type */
dacd8872 1760 return pkt;
1761}
1762
b185170a 1763/*
2e85c969 1764 * Construct an SSH-2 final-form packet: compress it, encrypt it,
b185170a 1765 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1766 * pkt->data. Total length is returned.
b185170a 1767 */
ff3187f6 1768static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1769{
7cca0d81 1770 int cipherblk, maclen, padding, i;
7cca0d81 1771
a8327734 1772 if (ssh->logctx)
ff3187f6 1773 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
acab36bc 1774 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
dacd8872 1775 pkt->body, pkt->length - (pkt->body - pkt->data),
ff3187f6 1776 pkt->nblanks, pkt->blanks);
1777 sfree(pkt->blanks); pkt->blanks = NULL;
1778 pkt->nblanks = 0;
00db133f 1779
7cca0d81 1780 /*
4ba9b64b 1781 * Compress packet payload.
1782 */
4ba9b64b 1783 {
1784 unsigned char *newpayload;
1785 int newlen;
51470298 1786 if (ssh->cscomp &&
ff3187f6 1787 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1788 pkt->length - 5,
51470298 1789 &newpayload, &newlen)) {
ff3187f6 1790 pkt->length = 5;
1791 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1792 sfree(newpayload);
4ba9b64b 1793 }
1794 }
1795
1796 /*
7cca0d81 1797 * Add padding. At least four bytes, and must also bring total
1798 * length (minus MAC) up to a multiple of the block size.
95d2d262 1799 * If pkt->forcepad is set, make sure the packet is at least that size
1800 * after padding.
7cca0d81 1801 */
51470298 1802 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1803 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1804 padding = 4;
95d2d262 1805 if (pkt->length + padding < pkt->forcepad)
1806 padding = pkt->forcepad - pkt->length;
32874aea 1807 padding +=
ff3187f6 1808 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
95d2d262 1809 assert(padding <= 255);
51470298 1810 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1811 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1812 pkt->data[4] = padding;
7cca0d81 1813 for (i = 0; i < padding; i++)
ff3187f6 1814 pkt->data[pkt->length + i] = random_byte();
1815 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1816 if (ssh->csmac)
ff3187f6 1817 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1818 pkt->length + padding,
51470298 1819 ssh->v2_outgoing_sequence);
1820 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1821
1822 if (ssh->cscipher)
371e569c 1823 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1824 pkt->data, pkt->length + padding);
51470298 1825
9442dd57 1826 pkt->encrypted_len = pkt->length + padding;
1827
ff3187f6 1828 /* Ready-to-send packet starts at pkt->data. We return length. */
1829 return pkt->length + padding + maclen;
b185170a 1830}
1831
1832/*
590f6a5f 1833 * Routines called from the main SSH code to send packets. There
1834 * are quite a few of these, because we have two separate
1835 * mechanisms for delaying the sending of packets:
1836 *
1837 * - In order to send an IGNORE message and a password message in
1838 * a single fixed-length blob, we require the ability to
1839 * concatenate the encrypted forms of those two packets _into_ a
1840 * single blob and then pass it to our <network.h> transport
1841 * layer in one go. Hence, there's a deferment mechanism which
1842 * works after packet encryption.
1843 *
1844 * - In order to avoid sending any connection-layer messages
1845 * during repeat key exchange, we have to queue up any such
1846 * outgoing messages _before_ they are encrypted (and in
1847 * particular before they're allocated sequence numbers), and
1848 * then send them once we've finished.
1849 *
1850 * I call these mechanisms `defer' and `queue' respectively, so as
1851 * to distinguish them reasonably easily.
1852 *
1853 * The functions send_noqueue() and defer_noqueue() free the packet
1854 * structure they are passed. Every outgoing packet goes through
1855 * precisely one of these functions in its life; packets passed to
1856 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1857 * these or get queued, and then when the queue is later emptied
1858 * the packets are all passed to defer_noqueue().
97ab28d7 1859 *
1860 * When using a CBC-mode cipher, it's necessary to ensure that an
1861 * attacker can't provide data to be encrypted using an IV that they
1862 * know. We ensure this by prefixing each packet that might contain
1863 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1864 * mechanism, so in this case send_noqueue() ends up redirecting to
1865 * defer_noqueue(). If you don't like this inefficiency, don't use
1866 * CBC.
b185170a 1867 */
590f6a5f 1868
97ab28d7 1869static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1870static void ssh_pkt_defersend(Ssh);
1871
590f6a5f 1872/*
2e85c969 1873 * Send an SSH-2 packet immediately, without queuing or deferring.
590f6a5f 1874 */
1875static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1876{
5471d09a 1877 int len;
1878 int backlog;
97ab28d7 1879 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1880 /* We need to send two packets, so use the deferral mechanism. */
1881 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1882 ssh_pkt_defersend(ssh);
1883 return;
1884 }
ff3187f6 1885 len = ssh2_pkt_construct(ssh, pkt);
bf8a49a1 1886 backlog = s_write(ssh, pkt->data, len);
5471d09a 1887 if (backlog > SSH_MAX_BACKLOG)
51470298 1888 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1889
1890 ssh->outgoing_data_size += pkt->encrypted_len;
1891 if (!ssh->kex_in_progress &&
d57f70af 1892 ssh->max_data_size != 0 &&
1893 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1894 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1895
ff3187f6 1896 ssh_free_packet(pkt);
b185170a 1897}
1898
1899/*
2e85c969 1900 * Defer an SSH-2 packet.
b185170a 1901 */
97ab28d7 1902static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
32874aea 1903{
97ab28d7 1904 int len;
1905 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1906 ssh->deferred_len == 0 && !noignore) {
1907 /*
1908 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1909 * get encrypted with a known IV.
1910 */
1911 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
27311cc7 1912 ssh2_pkt_addstring_start(ipkt);
97ab28d7 1913 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1914 }
1915 len = ssh2_pkt_construct(ssh, pkt);
51470298 1916 if (ssh->deferred_len + len > ssh->deferred_size) {
1917 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1918 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1919 ssh->deferred_size,
1920 unsigned char);
b185170a 1921 }
ff3187f6 1922 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1923 ssh->deferred_len += len;
9442dd57 1924 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1925 ssh_free_packet(pkt);
b185170a 1926}
1927
1928/*
2e85c969 1929 * Queue an SSH-2 packet.
590f6a5f 1930 */
1931static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1932{
1933 assert(ssh->queueing);
1934
1935 if (ssh->queuelen >= ssh->queuesize) {
1936 ssh->queuesize = ssh->queuelen + 32;
1937 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1938 }
1939
1940 ssh->queue[ssh->queuelen++] = pkt;
1941}
1942
1943/*
1944 * Either queue or send a packet, depending on whether queueing is
1945 * set.
1946 */
1947static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1948{
1949 if (ssh->queueing)
1950 ssh2_pkt_queue(ssh, pkt);
1951 else
1952 ssh2_pkt_send_noqueue(ssh, pkt);
1953}
1954
1955/*
1956 * Either queue or defer a packet, depending on whether queueing is
1957 * set.
1958 */
1959static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1960{
1961 if (ssh->queueing)
1962 ssh2_pkt_queue(ssh, pkt);
1963 else
97ab28d7 1964 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
590f6a5f 1965}
1966
1967/*
b185170a 1968 * Send the whole deferred data block constructed by
2e85c969 1969 * ssh2_pkt_defer() or SSH-1's defer_packet().
590f6a5f 1970 *
1971 * The expected use of the defer mechanism is that you call
1972 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1973 * not currently queueing, this simply sets up deferred_send_data
1974 * and then sends it. If we _are_ currently queueing, the calls to
1975 * ssh2_pkt_defer() put the deferred packets on to the queue
1976 * instead, and therefore ssh_pkt_defersend() has no deferred data
1977 * to send. Hence, there's no need to make it conditional on
1978 * ssh->queueing.
b185170a 1979 */
51470298 1980static void ssh_pkt_defersend(Ssh ssh)
32874aea 1981{
5471d09a 1982 int backlog;
bf8a49a1 1983 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
51470298 1984 ssh->deferred_len = ssh->deferred_size = 0;
1985 sfree(ssh->deferred_send_data);
1986 ssh->deferred_send_data = NULL;
5471d09a 1987 if (backlog > SSH_MAX_BACKLOG)
51470298 1988 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1989
1990 ssh->outgoing_data_size += ssh->deferred_data_size;
1991 if (!ssh->kex_in_progress &&
d57f70af 1992 ssh->max_data_size != 0 &&
1993 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1994 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1995 ssh->deferred_data_size = 0;
7cca0d81 1996}
1997
590f6a5f 1998/*
18524056 1999 * Send a packet whose length needs to be disguised (typically
2000 * passwords or keyboard-interactive responses).
2001 */
2002static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2003 int padsize)
2004{
2005#if 0
2006 if (0) {
2007 /*
2008 * The simplest way to do this is to adjust the
2009 * variable-length padding field in the outgoing packet.
2010 *
2011 * Currently compiled out, because some Cisco SSH servers
2012 * don't like excessively padded packets (bah, why's it
2013 * always Cisco?)
2014 */
2015 pkt->forcepad = padsize;
2016 ssh2_pkt_send(ssh, pkt);
2017 } else
2018#endif
2019 {
2020 /*
2021 * If we can't do that, however, an alternative approach is
2022 * to use the pkt_defer mechanism to bundle the packet
2023 * tightly together with an SSH_MSG_IGNORE such that their
2024 * combined length is a constant. So first we construct the
2025 * final form of this packet and defer its sending.
2026 */
2027 ssh2_pkt_defer(ssh, pkt);
2028
2029 /*
2030 * Now construct an SSH_MSG_IGNORE which includes a string
2031 * that's an exact multiple of the cipher block size. (If
2032 * the cipher is NULL so that the block size is
2033 * unavailable, we don't do this trick at all, because we
2034 * gain nothing by it.)
2035 */
2036 if (ssh->cscipher) {
2037 int stringlen, i;
2038
2039 stringlen = (256 - ssh->deferred_len);
2040 stringlen += ssh->cscipher->blksize - 1;
2041 stringlen -= (stringlen % ssh->cscipher->blksize);
2042 if (ssh->cscomp) {
2043 /*
2044 * Temporarily disable actual compression, so we
2045 * can guarantee to get this string exactly the
2046 * length we want it. The compression-disabling
2047 * routine should return an integer indicating how
2048 * many bytes we should adjust our string length
2049 * by.
2050 */
2051 stringlen -=
2052 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2053 }
2054 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2055 ssh2_pkt_addstring_start(pkt);
2056 for (i = 0; i < stringlen; i++) {
2057 char c = (char) random_byte();
2058 ssh2_pkt_addstring_data(pkt, &c, 1);
2059 }
2060 ssh2_pkt_defer(ssh, pkt);
2061 }
2062 ssh_pkt_defersend(ssh);
2063 }
2064}
2065
2066/*
2e85c969 2067 * Send all queued SSH-2 packets. We send them by means of
590f6a5f 2068 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2069 * packets that needed to be lumped together.
2070 */
2071static void ssh2_pkt_queuesend(Ssh ssh)
2072{
2073 int i;
2074
2075 assert(!ssh->queueing);
2076
2077 for (i = 0; i < ssh->queuelen; i++)
97ab28d7 2078 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
590f6a5f 2079 ssh->queuelen = 0;
2080
2081 ssh_pkt_defersend(ssh);
2082}
2083
7cca0d81 2084#if 0
32874aea 2085void bndebug(char *string, Bignum b)
2086{
7cca0d81 2087 unsigned char *p;
2088 int i, len;
2089 p = ssh2_mpint_fmt(b, &len);
2090 debug(("%s", string));
2091 for (i = 0; i < len; i++)
32874aea 2092 debug((" %02x", p[i]));
765c4200 2093 debug(("\n"));
dcbde236 2094 sfree(p);
7cca0d81 2095}
2096#endif
2097
b672f405 2098static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
32874aea 2099{
7cca0d81 2100 unsigned char *p;
2101 int len;
2102 p = ssh2_mpint_fmt(b, &len);
b672f405 2103 hash_string(h, s, p, len);
dcbde236 2104 sfree(p);
7cca0d81 2105}
2106
2107/*
2e85c969 2108 * Packet decode functions for both SSH-1 and SSH-2.
7cca0d81 2109 */
ff3187f6 2110static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 2111{
7cca0d81 2112 unsigned long value;
ff3187f6 2113 if (pkt->length - pkt->savedpos < 4)
32874aea 2114 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2115 value = GET_32BIT(pkt->body + pkt->savedpos);
2116 pkt->savedpos += 4;
7cca0d81 2117 return value;
2118}
ff3187f6 2119static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 2120{
65a22376 2121 unsigned long value;
ff3187f6 2122 if (pkt->length - pkt->savedpos < 1)
32874aea 2123 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 2124 value = pkt->body[pkt->savedpos] != 0;
2125 pkt->savedpos++;
65a22376 2126 return value;
2127}
ff3187f6 2128static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 2129{
57356d63 2130 int len;
7cca0d81 2131 *p = NULL;
45068b27 2132 *length = 0;
ff3187f6 2133 if (pkt->length - pkt->savedpos < 4)
32874aea 2134 return;
ff3187f6 2135 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 2136 if (len < 0)
2137 return;
2138 *length = len;
ff3187f6 2139 pkt->savedpos += 4;
2140 if (pkt->length - pkt->savedpos < *length)
32874aea 2141 return;
ff3187f6 2142 *p = (char *)(pkt->body + pkt->savedpos);
2143 pkt->savedpos += *length;
7cca0d81 2144}
ff3187f6 2145static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 2146{
ff3187f6 2147 if (pkt->length - pkt->savedpos < length)
0016d70b 2148 return NULL;
ff3187f6 2149 pkt->savedpos += length;
2150 return pkt->body + (pkt->savedpos - length);
0016d70b 2151}
ff3187f6 2152static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 2153 unsigned char **keystr)
2154{
2155 int j;
2156
ff3187f6 2157 j = makekey(pkt->body + pkt->savedpos,
2158 pkt->length - pkt->savedpos,
0016d70b 2159 key, keystr, 0);
2160
2161 if (j < 0)
2162 return FALSE;
2163
ff3187f6 2164 pkt->savedpos += j;
2165 assert(pkt->savedpos < pkt->length);
0016d70b 2166
2167 return TRUE;
2168}
ff3187f6 2169static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 2170{
2171 int j;
2172 Bignum b;
2173
ff3187f6 2174 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2175 pkt->length - pkt->savedpos, &b);
0016d70b 2176
2177 if (j < 0)
2178 return NULL;
2179
ff3187f6 2180 pkt->savedpos += j;
0016d70b 2181 return b;
2182}
ff3187f6 2183static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 2184{
7cca0d81 2185 char *p;
3709bfe9 2186 int length;
7cca0d81 2187 Bignum b;
2188
ff3187f6 2189 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 2190 if (!p)
32874aea 2191 return NULL;
ff3187f6 2192 if (p[0] & 0x80)
32874aea 2193 return NULL;
d8baa528 2194 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 2195 return b;
2196}
2197
7d503c31 2198/*
2e85c969 2199 * Helper function to add an SSH-2 signature blob to a packet.
1dd353b5 2200 * Expects to be shown the public key blob as well as the signature
2201 * blob. Normally works just like ssh2_pkt_addstring, but will
2202 * fiddle with the signature packet if necessary for
2203 * BUG_SSH2_RSA_PADDING.
2204 */
ff3187f6 2205static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2206 void *pkblob_v, int pkblob_len,
1dd353b5 2207 void *sigblob_v, int sigblob_len)
2208{
2209 unsigned char *pkblob = (unsigned char *)pkblob_v;
2210 unsigned char *sigblob = (unsigned char *)sigblob_v;
2211
2212 /* dmemdump(pkblob, pkblob_len); */
2213 /* dmemdump(sigblob, sigblob_len); */
2214
2215 /*
2216 * See if this is in fact an ssh-rsa signature and a buggy
2217 * server; otherwise we can just do this the easy way.
2218 */
51470298 2219 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 2220 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2221 int pos, len, siglen;
2222
2223 /*
2224 * Find the byte length of the modulus.
2225 */
2226
2227 pos = 4+7; /* skip over "ssh-rsa" */
2228 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2229 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2230 pos += 4; /* find modulus itself */
2231 while (len > 0 && pkblob[pos] == 0)
2232 len--, pos++;
2233 /* debug(("modulus length is %d\n", len)); */
2234
2235 /*
2236 * Now find the signature integer.
2237 */
2238 pos = 4+7; /* skip over "ssh-rsa" */
2239 siglen = GET_32BIT(sigblob+pos);
2240 /* debug(("signature length is %d\n", siglen)); */
2241
2242 if (len != siglen) {
2243 unsigned char newlen[4];
ff3187f6 2244 ssh2_pkt_addstring_start(pkt);
2245 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2246 /* dmemdump(sigblob, pos); */
2247 pos += 4; /* point to start of actual sig */
2248 PUT_32BIT(newlen, len);
ff3187f6 2249 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2250 /* dmemdump(newlen, 4); */
2251 newlen[0] = 0;
2252 while (len-- > siglen) {
ff3187f6 2253 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2254 /* dmemdump(newlen, 1); */
2255 }
ff3187f6 2256 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2257 /* dmemdump(sigblob+pos, siglen); */
2258 return;
2259 }
2260
2261 /* Otherwise fall through and do it the easy way. */
2262 }
2263
ff3187f6 2264 ssh2_pkt_addstring_start(pkt);
2265 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2266}
2267
2268/*
7d503c31 2269 * Examine the remote side's version string and compare it against
2270 * a list of known buggy implementations.
2271 */
51470298 2272static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2273{
2274 char *imp; /* pointer to implementation part */
7d503c31 2275 imp = vstring;
2276 imp += strcspn(imp, "-");
bd358db1 2277 if (*imp) imp++;
7d503c31 2278 imp += strcspn(imp, "-");
bd358db1 2279 if (*imp) imp++;
7d503c31 2280
51470298 2281 ssh->remote_bugs = 0;
7d503c31 2282
bf982899 2283 /*
2284 * General notes on server version strings:
2285 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2286 * here -- in particular, we've heard of one that's perfectly happy
2287 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2288 * so we can't distinguish them.
2289 */
5ecd7ad0 2290 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2291 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 2292 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2293 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2294 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2295 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2296 /*
2297 * These versions don't support SSH1_MSG_IGNORE, so we have
2298 * to use a different defence against password length
2299 * sniffing.
2300 */
51470298 2301 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2e85c969 2302 logevent("We believe remote version has SSH-1 ignore bug");
7d503c31 2303 }
2304
5ecd7ad0 2305 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2306 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 2307 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2308 /*
2309 * These versions need a plain password sent; they can't
2310 * handle having a null and a random length of data after
2311 * the password.
2312 */
51470298 2313 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2e85c969 2314 logevent("We believe remote version needs a plain SSH-1 password");
bd358db1 2315 }
2316
5ecd7ad0 2317 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2318 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2319 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2320 /*
2321 * These versions apparently have no clue whatever about
2322 * RSA authentication and will panic and die if they see
2323 * an AUTH_RSA message.
2324 */
51470298 2325 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
19f47a7d 2326 logevent("We believe remote version can't handle SSH-1 RSA authentication");
0df73905 2327 }
2328
5ecd7ad0 2329 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2330 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2331 !wc_match("* VShell", imp) &&
831301f6 2332 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2333 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2334 wc_match("2.1 *", imp)))) {
32874aea 2335 /*
2336 * These versions have the HMAC bug.
2337 */
51470298 2338 ssh->remote_bugs |= BUG_SSH2_HMAC;
2e85c969 2339 logevent("We believe remote version has SSH-2 HMAC bug");
7d503c31 2340 }
1dd353b5 2341
5ecd7ad0 2342 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2343 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2344 !wc_match("* VShell", imp) &&
2856a1b9 2345 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2346 /*
2347 * These versions have the key-derivation bug (failing to
2348 * include the literal shared secret in the hashes that
2349 * generate the keys).
2350 */
51470298 2351 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2e85c969 2352 logevent("We believe remote version has SSH-2 key-derivation bug");
088bde77 2353 }
2354
5ecd7ad0 2355 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2356 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2357 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2358 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2359 /*
2e85c969 2360 * These versions have the SSH-2 RSA padding bug.
1dd353b5 2361 */
51470298 2362 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2e85c969 2363 logevent("We believe remote version has SSH-2 RSA padding bug");
1dd353b5 2364 }
8e975795 2365
dda87a28 2366 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2367 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2368 wc_match("OpenSSH_2.[0-2]*", imp))) {
2369 /*
2e85c969 2370 * These versions have the SSH-2 session-ID bug in
dda87a28 2371 * public-key authentication.
2372 */
2373 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2e85c969 2374 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
dda87a28 2375 }
f382c87d 2376
2377 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2378 (ssh->cfg.sshbug_rekey2 == AUTO &&
39b8712f 2379 (wc_match("DigiSSH_2.0", imp) ||
2380 wc_match("OpenSSH_2.[0-4]*", imp) ||
e12d95a5 2381 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2382 wc_match("Sun_SSH_1.0", imp) ||
f4275b53 2383 wc_match("Sun_SSH_1.0.1", imp) ||
96bd26de 2384 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2385 wc_match("WeOnlyDo-*", imp)))) {
f382c87d 2386 /*
2e85c969 2387 * These versions have the SSH-2 rekey bug.
f382c87d 2388 */
2389 ssh->remote_bugs |= BUG_SSH2_REKEY;
2e85c969 2390 logevent("We believe remote version has SSH-2 rekey bug");
f382c87d 2391 }
7d503c31 2392}
2393
d38d6a1f 2394/*
2395 * The `software version' part of an SSH version string is required
2396 * to contain no spaces or minus signs.
2397 */
2398static void ssh_fix_verstring(char *str)
2399{
2400 /* Eat "SSH-<protoversion>-". */
2401 assert(*str == 'S'); str++;
2402 assert(*str == 'S'); str++;
2403 assert(*str == 'H'); str++;
2404 assert(*str == '-'); str++;
2405 while (*str && *str != '-') str++;
2406 assert(*str == '-'); str++;
2407
2408 /* Convert minus signs and spaces in the remaining string into
2409 * underscores. */
2410 while (*str) {
2411 if (*str == '-' || *str == ' ')
2412 *str = '_';
2413 str++;
2414 }
2415}
2416
1fcd0d98 2417/*
2418 * Send an appropriate SSH version string.
2419 */
2420static void ssh_send_verstring(Ssh ssh, char *svers)
2421{
2422 char *verstring;
2423
2424 if (ssh->version == 2) {
2425 /*
2426 * Construct a v2 version string.
2427 */
2428 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2429 } else {
2430 /*
2431 * Construct a v1 version string.
2432 */
2433 verstring = dupprintf("SSH-%s-%s\012",
2434 (ssh_versioncmp(svers, "1.5") <= 0 ?
2435 svers : "1.5"),
2436 sshver);
2437 }
2438
2439 ssh_fix_verstring(verstring);
2440
2441 if (ssh->version == 2) {
2442 size_t len;
2443 /*
2444 * Record our version string.
2445 */
2446 len = strcspn(verstring, "\015\012");
2447 ssh->v_c = snewn(len + 1, char);
2448 memcpy(ssh->v_c, verstring, len);
2449 ssh->v_c[len] = 0;
2450 }
2451
2452 logeventf(ssh, "We claim version: %.*s",
2453 strcspn(verstring, "\015\012"), verstring);
2454 s_write(ssh, verstring, strlen(verstring));
2455 sfree(verstring);
2456}
2457
51470298 2458static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2459{
51470298 2460 struct do_ssh_init_state {
2461 int vslen;
2462 char version[10];
2463 char *vstring;
2464 int vstrsize;
2465 int i;
2466 int proto1, proto2;
2467 };
2468 crState(do_ssh_init_state);
374330e2 2469
51470298 2470 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2471
8c1835c0 2472 /* Search for a line beginning with the string "SSH-" in the input. */
2473 for (;;) {
2474 if (c != 'S') goto no;
2475 crReturn(1);
2476 if (c != 'S') goto no;
2477 crReturn(1);
2478 if (c != 'H') goto no;
2479 crReturn(1);
2480 if (c != '-') goto no;
2481 break;
2482 no:
2483 while (c != '\012')
2484 crReturn(1);
2485 crReturn(1);
374330e2 2486 }
8df7a775 2487
51470298 2488 s->vstrsize = 16;
3d88e64d 2489 s->vstring = snewn(s->vstrsize, char);
51470298 2490 strcpy(s->vstring, "SSH-");
2491 s->vslen = 4;
2492 s->i = 0;
374330e2 2493 while (1) {
8df7a775 2494 crReturn(1); /* get another char */
51470298 2495 if (s->vslen >= s->vstrsize - 1) {
2496 s->vstrsize += 16;
3d88e64d 2497 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2498 }
51470298 2499 s->vstring[s->vslen++] = c;
2500 if (s->i >= 0) {
374330e2 2501 if (c == '-') {
51470298 2502 s->version[s->i] = '\0';
2503 s->i = -1;
2504 } else if (s->i < sizeof(s->version) - 1)
2505 s->version[s->i++] = c;
c4ffc4d0 2506 } else if (c == '\012')
374330e2 2507 break;
2508 }
2509
51470298 2510 ssh->agentfwd_enabled = FALSE;
2511 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2512
51470298 2513 s->vstring[s->vslen] = 0;
a7d4653a 2514 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
fb983202 2515 logeventf(ssh, "Server version: %s", s->vstring);
51470298 2516 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2517
adf799dd 2518 /*
38d228a2 2519 * Decide which SSH protocol version to support.
adf799dd 2520 */
38d228a2 2521
2522 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2523 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2524 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2525 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2526
86916870 2527 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2528 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2529 crStop(0);
38d228a2 2530 }
86916870 2531 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2532 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2533 crStop(0);
38d228a2 2534 }
2535
1fcd0d98 2536 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1))
2537 ssh->version = 2;
2538 else
2539 ssh->version = 1;
d38d6a1f 2540
2541 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2542
1fcd0d98 2543 /* Send the version string, if we haven't already */
2544 if (ssh->cfg.sshprot != 3)
2545 ssh_send_verstring(ssh, s->version);
2546
2547 if (ssh->version == 2) {
2548 size_t len;
2549 /*
2550 * Record their version string.
2551 */
2552 len = strcspn(s->vstring, "\015\012");
2553 ssh->v_s = snewn(len + 1, char);
2554 memcpy(ssh->v_s, s->vstring, len);
2555 ssh->v_s[len] = 0;
2556
2557 /*
2558 * Initialise SSH-2 protocol.
2559 */
2560 ssh->protocol = ssh2_protocol;
2561 ssh2_protocol_setup(ssh);
2562 ssh->s_rdpkt = ssh2_rdpkt;
2563 } else {
2564 /*
2565 * Initialise SSH-1 protocol.
2566 */
2567 ssh->protocol = ssh1_protocol;
2568 ssh1_protocol_setup(ssh);
2569 ssh->s_rdpkt = ssh1_rdpkt;
2570 }
2571 if (ssh->version == 2)
2572 do_ssh2_transport(ssh, NULL, -1, NULL);
2573
125105d1 2574 update_specials_menu(ssh->frontend);
51470298 2575 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2576 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2577
51470298 2578 sfree(s->vstring);
50526e47 2579
8df7a775 2580 crFinish(0);
2581}
2582
3d9449a1 2583static void ssh_process_incoming_data(Ssh ssh,
2584 unsigned char **data, int *datalen)
2585{
bf8a49a1 2586 struct Packet *pktin;
2587
2588 pktin = ssh->s_rdpkt(ssh, data, datalen);
3d9449a1 2589 if (pktin) {
2590 ssh->protocol(ssh, NULL, 0, pktin);
2591 ssh_free_packet(pktin);
2592 }
2593}
2594
2595static void ssh_queue_incoming_data(Ssh ssh,
2596 unsigned char **data, int *datalen)
2597{
2598 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2599 *data += *datalen;
2600 *datalen = 0;
2601}
2602
2603static void ssh_process_queued_incoming_data(Ssh ssh)
2604{
2605 void *vdata;
2606 unsigned char *data;
2607 int len, origlen;
2608
2609 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2610 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2611 data = vdata;
2612 origlen = len;
2613
2614 while (!ssh->frozen && len > 0)
2615 ssh_process_incoming_data(ssh, &data, &len);
2616
2617 if (origlen > len)
2618 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2619 }
2620}
2621
2622static void ssh_set_frozen(Ssh ssh, int frozen)
2623{
a5a6f839 2624 if (ssh->s)
2625 sk_set_frozen(ssh->s, frozen);
3d9449a1 2626 ssh->frozen = frozen;
2627}
2628
51470298 2629static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2630{
bf8a49a1 2631 /* Log raw data, if we're in that mode. */
ff05dfef 2632 if (ssh->logctx)
2633 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2634 0, NULL);
bf8a49a1 2635
51470298 2636 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2637
2638 /*
2639 * To begin with, feed the characters one by one to the
2640 * protocol initialisation / selection function do_ssh_init().
2641 * When that returns 0, we're done with the initial greeting
2642 * exchange and can move on to packet discipline.
2643 */
2644 while (1) {
51470298 2645 int ret; /* need not be kept across crReturn */
8df7a775 2646 if (datalen == 0)
2647 crReturnV; /* more data please */
51470298 2648 ret = do_ssh_init(ssh, *data);
32874aea 2649 data++;
2650 datalen--;
8df7a775 2651 if (ret == 0)
2652 break;
2653 }
2654
2655 /*
2656 * We emerge from that loop when the initial negotiation is
2657 * over and we have selected an s_rdpkt function. Now pass
2658 * everything to s_rdpkt, and then pass the resulting packets
2659 * to the proper protocol handler.
2660 */
3d9449a1 2661
8df7a775 2662 while (1) {
e375106c 2663 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2664 if (ssh->frozen) {
3d9449a1 2665 ssh_queue_incoming_data(ssh, &data, &datalen);
e375106c 2666 /* This uses up all data and cannot cause anything interesting
2667 * to happen; indeed, for anything to happen at all, we must
2668 * return, so break out. */
2669 break;
2670 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2671 /* This uses up some or all data, and may freeze the
2672 * session. */
2673 ssh_process_queued_incoming_data(ssh);
2674 } else {
2675 /* This uses up some or all data, and may freeze the
2676 * session. */
2677 ssh_process_incoming_data(ssh, &data, &datalen);
2678 }
2679 /* FIXME this is probably EBW. */
ff3187f6 2680 if (ssh->state == SSH_STATE_CLOSED)
2681 return;
8df7a775 2682 }
e375106c 2683 /* We're out of data. Go and get some more. */
8df7a775 2684 crReturnV;
2685 }
2686 crFinishV;
2687}
2688
ac934965 2689static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2690{
80ffa58b 2691 int ret = 0;
36f94d1f 2692 struct ssh_channel *c;
2693
51470298 2694 ssh->state = SSH_STATE_CLOSED;
ecbb0000 2695 expire_timer_context(ssh);
51470298 2696 if (ssh->s) {
2697 sk_close(ssh->s);
2698 ssh->s = NULL;
ac934965 2699 if (notify_exit)
2700 notify_remote_exit(ssh->frontend);
2701 else
2702 ret = 1;
f3ab576e 2703 }
36f94d1f 2704 /*
80ffa58b 2705 * Now we must shut down any port- and X-forwarded channels going
36f94d1f 2706 * through this connection.
2707 */
74a98066 2708 if (ssh->channels) {
80ffa58b 2709 while (NULL != (c = index234(ssh->channels, 0))) {
74a98066 2710 switch (c->type) {
2711 case CHAN_X11:
2712 x11_close(c->u.x11.s);
2713 break;
2714 case CHAN_SOCKDATA:
2715 pfd_close(c->u.pfd.s);
2716 break;
2717 }
80ffa58b 2718 del234(ssh->channels, c); /* moving next one to index 0 */
74a98066 2719 if (ssh->version == 2)
2720 bufchain_clear(&c->v.v2.outbuffer);
2721 sfree(c);
36f94d1f 2722 }
36f94d1f 2723 }
f8c9f9df 2724 /*
2725 * Go through port-forwardings, and close any associated
2726 * listening sockets.
2727 */
2728 if (ssh->portfwds) {
2729 struct ssh_portfwd *pf;
2730 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2731 /* Dispose of any listening socket. */
2732 if (pf->local)
2733 pfd_terminate(pf->local);
2734 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2735 free_portfwd(pf);
2736 }
2737 }
ac934965 2738
2739 return ret;
36f94d1f 2740}
2741
7555d6a5 2742static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2743 const char *error_msg, int error_code)
2744{
2745 Ssh ssh = (Ssh) plug;
2746 char addrbuf[256], *msg;
2747
2748 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2749
2750 if (type == 0)
2751 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2752 else
2753 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2754
2755 logevent(msg);
fb983202 2756 sfree(msg);
7555d6a5 2757}
2758
cbe2d68f 2759static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2760 int calling_back)
2761{
2762 Ssh ssh = (Ssh) plug;
ac934965 2763 int need_notify = ssh_do_close(ssh, FALSE);
2764
9e296bfa 2765 if (!error_msg) {
2766 if (!ssh->close_expected)
2767 error_msg = "Server unexpectedly closed network connection";
2768 else
2769 error_msg = "Server closed network connection";
ac934965 2770 }
2771
d051d1b4 2772 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2773 ssh->exitcode = 0;
2774
2425184b 2775 if (need_notify)
2776 notify_remote_exit(ssh->frontend);
2777
9e296bfa 2778 if (error_msg)
247308b5 2779 logevent(error_msg);
9e296bfa 2780 if (!ssh->close_expected || !ssh->clean_exit)
971bcc0a 2781 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2782 return 0;
2783}
2784
32874aea 2785static int ssh_receive(Plug plug, int urgent, char *data, int len)
2786{
51470298 2787 Ssh ssh = (Ssh) plug;
d8baa528 2788 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2789 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 2790 ssh_do_close(ssh, TRUE);
32874aea 2791 return 0;
3257deae 2792 }
fef97f43 2793 return 1;
374330e2 2794}
2795
5471d09a 2796static void ssh_sent(Plug plug, int bufsize)
2797{
51470298 2798 Ssh ssh = (Ssh) plug;
5471d09a 2799 /*
2800 * If the send backlog on the SSH socket itself clears, we
2801 * should unthrottle the whole world if it was throttled.
2802 */
2803 if (bufsize < SSH_MAX_BACKLOG)
51470298 2804 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2805}
2806
fb09bf1c 2807/*
8df7a775 2808 * Connect to specified host and port.
2809 * Returns an error message, or NULL on success.
6e1ebb76 2810 * Also places the canonical host name into `realhost'. It must be
2811 * freed by the caller.
8df7a775 2812 */
cbe2d68f 2813static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2814 char **realhost, int nodelay, int keepalive)
8df7a775 2815{
51470298 2816 static const struct plug_function_table fn_table = {
7555d6a5 2817 ssh_log,
7e78000d 2818 ssh_closing,
5471d09a 2819 ssh_receive,
2820 ssh_sent,
2821 NULL
51470298 2822 };
7e78000d 2823
8df7a775 2824 SockAddr addr;
cbe2d68f 2825 const char *err;
8df7a775 2826
3d88e64d 2827 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2828 strcpy(ssh->savedhost, host);
8df7a775 2829
2830 if (port < 0)
2831 port = 22; /* default ssh port */
51470298 2832 ssh->savedport = port;
8df7a775 2833
2834 /*
2835 * Try to find host.
2836 */
05581745 2837 logeventf(ssh, "Looking up host \"%s\"%s", host,
2838 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2839 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2840 addr = name_lookup(host, port, realhost, &ssh->cfg,
2841 ssh->cfg.addressfamily);
170c1e6e 2842 if ((err = sk_addr_error(addr)) != NULL) {
2843 sk_addr_free(addr);
8df7a775 2844 return err;
170c1e6e 2845 }
8df7a775 2846
8df7a775 2847 /*
2848 * Open socket.
2849 */
51470298 2850 ssh->fn = &fn_table;
e8fa8f62 2851 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2852 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2853 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2854 ssh->s = NULL;
39934deb 2855 notify_remote_exit(ssh->frontend);
8df7a775 2856 return err;
67c4ba2e 2857 }
8df7a775 2858
ff05dfef 2859 /*
2860 * If the SSH version number's fixed, set it now, and if it's SSH-2,
2861 * send the version string too.
2862 */
2863 if (ssh->cfg.sshprot == 0)
2864 ssh->version = 1;
2865 if (ssh->cfg.sshprot == 3) {
2866 ssh->version = 2;
2867 ssh_send_verstring(ssh, NULL);
2868 }
2869
8df7a775 2870 return NULL;
2871}
2872
2873/*
5471d09a 2874 * Throttle or unthrottle the SSH connection.
2875 */
51470298 2876static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2877{
51470298 2878 int old_count = ssh->v1_throttle_count;
2879 ssh->v1_throttle_count += adjust;
2880 assert(ssh->v1_throttle_count >= 0);
2881 if (ssh->v1_throttle_count && !old_count) {
3d9449a1 2882 ssh_set_frozen(ssh, 1);
51470298 2883 } else if (!ssh->v1_throttle_count && old_count) {
3d9449a1 2884 ssh_set_frozen(ssh, 0);
5471d09a 2885 }
2886}
2887
2888/*
2889 * Throttle or unthrottle _all_ local data streams (for when sends
2890 * on the SSH connection itself back up).
2891 */
51470298 2892static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2893{
2894 int i;
2895 struct ssh_channel *c;
2896
51470298 2897 if (enable == ssh->throttled_all)
5471d09a 2898 return;
51470298 2899 ssh->throttled_all = enable;
2900 ssh->overall_bufsize = bufsize;
2901 if (!ssh->channels)
5471d09a 2902 return;
51470298 2903 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2904 switch (c->type) {
2905 case CHAN_MAINSESSION:
2906 /*
2907 * This is treated separately, outside the switch.
2908 */
2909 break;
2910 case CHAN_X11:
2911 x11_override_throttle(c->u.x11.s, enable);
2912 break;
2913 case CHAN_AGENT:
2914 /* Agent channels require no buffer management. */
2915 break;
2916 case CHAN_SOCKDATA:
36f94d1f 2917 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2918 break;
2919 }
2920 }
2921}
2922
f11d78f2 2923static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2924{
2925 Ssh ssh = (Ssh) sshv;
2926
2927 ssh->agent_response = reply;
2928 ssh->agent_response_len = replylen;
2929
2930 if (ssh->version == 1)
ff3187f6 2931 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2932 else
ff3187f6 2933 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2934}
2935
3d9449a1 2936static void ssh_dialog_callback(void *sshv, int ret)
2937{
2938 Ssh ssh = (Ssh) sshv;
2939
2940 ssh->user_response = ret;
2941
2942 if (ssh->version == 1)
2943 do_ssh1_login(ssh, NULL, -1, NULL);
2944 else
2945 do_ssh2_transport(ssh, NULL, -1, NULL);
2946
2947 /*
2948 * This may have unfrozen the SSH connection, so do a
2949 * queued-data run.
2950 */
2951 ssh_process_queued_incoming_data(ssh);
2952}
2953
f11d78f2 2954static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2955{
2956 struct ssh_channel *c = (struct ssh_channel *)cv;
2957 Ssh ssh = c->ssh;
2958 void *sentreply = reply;
2959
2960 if (!sentreply) {
2961 /* Fake SSH_AGENT_FAILURE. */
2962 sentreply = "\0\0\0\1\5";
2963 replylen = 5;
2964 }
2965 if (ssh->version == 2) {
2966 ssh2_add_channel_data(c, sentreply, replylen);
2967 ssh2_try_send(c);
2968 } else {
2969 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2970 PKT_INT, c->remoteid,
2971 PKT_INT, replylen,
a2724fba 2972 PKTT_DATA,
839f10db 2973 PKT_DATA, sentreply, replylen,
9a10ecf4 2974 PKTT_OTHER,
839f10db 2975 PKT_END);
2976 }
2977 if (reply)
2978 sfree(reply);
2979}
2980
0405e71f 2981/*
9e296bfa 2982 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2983 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2984 * => log `wire_reason'.
2985 */
2986static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2987 int code, int clean_exit)
2988{
2989 char *error;
2990 if (!client_reason)
2991 client_reason = wire_reason;
2992 if (client_reason)
2993 error = dupprintf("Disconnected: %s", client_reason);
2994 else
2995 error = dupstr("Disconnected");
2996 if (wire_reason) {
2997 if (ssh->version == 1) {
2998 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2999 PKT_END);
3000 } else if (ssh->version == 2) {
3001 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3002 ssh2_pkt_adduint32(pktout, code);
3003 ssh2_pkt_addstring(pktout, wire_reason);
3004 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3005 ssh2_pkt_send_noqueue(ssh, pktout);
3006 }
3007 }
3008 ssh->close_expected = TRUE;
3009 ssh->clean_exit = clean_exit;
3010 ssh_closing((Plug)ssh, error, 0, 0);
3011 sfree(error);
3012}
3013
3014/*
fb09bf1c 3015 * Handle the key exchange and user authentication phases.
3016 */
ff3187f6 3017static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3018 struct Packet *pktin)
fb09bf1c 3019{
0016d70b 3020 int i, j, ret;
3021 unsigned char cookie[8], *ptr;
374330e2 3022 struct RSAKey servkey, hostkey;
3023 struct MD5Context md5c;
51470298 3024 struct do_ssh1_login_state {
3025 int len;
3026 unsigned char *rsabuf, *keystr1, *keystr2;
3027 unsigned long supported_ciphers_mask, supported_auths_mask;
3028 int tried_publickey, tried_agent;
3029 int tis_auth_refused, ccard_auth_refused;
3030 unsigned char session_id[16];
3031 int cipher_type;
3032 char username[100];
3033 void *publickey_blob;
3034 int publickey_bloblen;
edd0cb8a 3035 char *publickey_comment;
3036 int publickey_encrypted;
3037 prompts_t *cur_prompt;
51470298 3038 char c;
3039 int pwpkt_type;
3040 unsigned char request[5], *response, *p;
3041 int responselen;
3042 int keyi, nkeys;
3043 int authed;
3044 struct RSAKey key;
3045 Bignum challenge;
3046 char *commentp;
3047 int commentlen;
3d9449a1 3048 int dlgret;
51470298 3049 };
3050 crState(do_ssh1_login_state);
3051
3052 crBegin(ssh->do_ssh1_login_crstate);
374330e2 3053
ff3187f6 3054 if (!pktin)
3055 crWaitUntil(pktin);
374330e2 3056
ff3187f6 3057 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 3058 bombout(("Public key packet not received"));
7ffdbc1a 3059 crStop(0);
8d5de777 3060 }
374330e2 3061
c5e9c988 3062 logevent("Received public keys");
374330e2 3063
ff3187f6 3064 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 3065 if (!ptr) {
2e85c969 3066 bombout(("SSH-1 public key packet stopped before random cookie"));
0016d70b 3067 crStop(0);
3068 }
3069 memcpy(cookie, ptr, 8);
374330e2 3070
ff3187f6 3071 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3072 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2e85c969 3073 bombout(("Failed to read SSH-1 public keys from public key packet"));
0016d70b 3074 crStop(0);
3075 }
374330e2 3076
c5e9c988 3077 /*
1c2a93c4 3078 * Log the host key fingerprint.
c5e9c988 3079 */
c5e9c988 3080 {
3081 char logmsg[80];
1c2a93c4 3082 logevent("Host key fingerprint is:");
c5e9c988 3083 strcpy(logmsg, " ");
32874aea 3084 hostkey.comment = NULL;
3085 rsa_fingerprint(logmsg + strlen(logmsg),
3086 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 3087 logevent(logmsg);
3088 }
3089
ff3187f6 3090 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3091 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3092 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
d5b2c841 3093 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3094 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
bea1ef5f 3095
51470298 3096 ssh->v1_local_protoflags =
3097 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3098 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 3099
c5e9c988 3100 MD5Init(&md5c);
51470298 3101 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3102 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 3103 MD5Update(&md5c, cookie, 8);
51470298 3104 MD5Final(s->session_id, &md5c);
374330e2 3105
32874aea 3106 for (i = 0; i < 32; i++)
51470298 3107 ssh->session_key[i] = random_byte();
374330e2 3108
0016d70b 3109 /*
3110 * Verify that the `bits' and `bytes' parameters match.
3111 */
3112 if (hostkey.bits > hostkey.bytes * 8 ||
3113 servkey.bits > servkey.bytes * 8) {
2e85c969 3114 bombout(("SSH-1 public keys were badly formatted"));
0016d70b 3115 crStop(0);
3116 }
3117
51470298 3118 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 3119
3d88e64d 3120 s->rsabuf = snewn(s->len, unsigned char);
374330e2 3121
89ee5268 3122 /*
3123 * Verify the host key.
3124 */
3125 {
32874aea 3126 /*
3127 * First format the key into a string.
3128 */
3129 int len = rsastr_len(&hostkey);
3130 char fingerprint[100];
3d88e64d 3131 char *keystr = snewn(len, char);
32874aea 3132 rsastr_fmt(keystr, &hostkey);
3133 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3d9449a1 3134
3135 ssh_set_frozen(ssh, 1);
3136 s->dlgret = verify_ssh_host_key(ssh->frontend,
3137 ssh->savedhost, ssh->savedport,
3138 "rsa", keystr, fingerprint,
3139 ssh_dialog_callback, ssh);
32874aea 3140 sfree(keystr);
3d9449a1 3141 if (s->dlgret < 0) {
3142 do {
3143 crReturn(0);
3144 if (pktin) {
3145 bombout(("Unexpected data from server while waiting"
3146 " for user host key response"));
3147 crStop(0);
3148 }
3149 } while (pktin || inlen > 0);
3150 s->dlgret = ssh->user_response;
3151 }
3152 ssh_set_frozen(ssh, 0);
3153
3154 if (s->dlgret == 0) {
9e296bfa 3155 ssh_disconnect(ssh, "User aborted at host key verification",
3156 NULL, 0, TRUE);
2b3f6c19 3157 crStop(0);
3d9449a1 3158 }
32874aea 3159 }
3160
3161 for (i = 0; i < 32; i++) {
51470298 3162 s->rsabuf[i] = ssh->session_key[i];
374330e2 3163 if (i < 16)
51470298 3164 s->rsabuf[i] ^= s->session_id[i];
374330e2 3165 }
3166
3167 if (hostkey.bytes > servkey.bytes) {
0016d70b 3168 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3169 if (ret)
3170 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 3171 } else {
0016d70b 3172 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3173 if (ret)
3174 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3175 }
3176 if (!ret) {
2e85c969 3177 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
0016d70b 3178 crStop(0);
374330e2 3179 }
3180
c5e9c988 3181 logevent("Encrypted session key");
3182
ca20bfcf 3183 {
3184 int cipher_chosen = 0, warn = 0;
3185 char *cipher_string = NULL;
51470298 3186 int i;
ca20bfcf 3187 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 3188 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 3189 if (next_cipher == CIPHER_WARN) {
3190 /* If/when we choose a cipher, warn about it */
3191 warn = 1;
3192 } else if (next_cipher == CIPHER_AES) {
3193 /* XXX Probably don't need to mention this. */
2e85c969 3194 logevent("AES not supported in SSH-1, skipping");
ca20bfcf 3195 } else {
3196 switch (next_cipher) {
51470298 3197 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 3198 cipher_string = "3DES"; break;
51470298 3199 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 3200 cipher_string = "Blowfish"; break;
51470298 3201 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 3202 cipher_string = "single-DES"; break;
3203 }
51470298 3204 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 3205 cipher_chosen = 1;
3206 }
3207 }
3208 if (!cipher_chosen) {
51470298 3209 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2e85c969 3210 bombout(("Server violates SSH-1 protocol by not "
ca20bfcf 3211 "supporting 3DES encryption"));
3212 else
3213 /* shouldn't happen */
6b5cf8b4 3214 bombout(("No supported ciphers found"));
7ffdbc1a 3215 crStop(0);
a99a05c0 3216 }
ca20bfcf 3217
3218 /* Warn about chosen cipher if necessary. */
bb348ab1 3219 if (warn) {
3d9449a1 3220 ssh_set_frozen(ssh, 1);
3221 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3222 ssh_dialog_callback, ssh);
3223 if (s->dlgret < 0) {
3224 do {
3225 crReturn(0);
3226 if (pktin) {
3227 bombout(("Unexpected data from server while waiting"
3228 " for user response"));
3229 crStop(0);
3230 }
3231 } while (pktin || inlen > 0);
3232 s->dlgret = ssh->user_response;
3233 }
3234 ssh_set_frozen(ssh, 0);
3235 if (s->dlgret == 0) {
9e296bfa 3236 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3237 0, TRUE);
96ccde8b 3238 crStop(0);
3d9449a1 3239 }
bb348ab1 3240 }
bea1ef5f 3241 }
ca20bfcf 3242
51470298 3243 switch (s->cipher_type) {
32874aea 3244 case SSH_CIPHER_3DES:
3245 logevent("Using 3DES encryption");
3246 break;
3247 case SSH_CIPHER_DES:
3248 logevent("Using single-DES encryption");
3249 break;
3250 case SSH_CIPHER_BLOWFISH:
3251 logevent("Using Blowfish encryption");
3252 break;
c5e9c988 3253 }
bea1ef5f 3254
51470298 3255 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3256 PKT_CHAR, s->cipher_type,
32874aea 3257 PKT_DATA, cookie, 8,
51470298 3258 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3259 PKT_DATA, s->rsabuf, s->len,
3260 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3261
c5e9c988 3262 logevent("Trying to enable encryption...");
374330e2 3263
51470298 3264 sfree(s->rsabuf);
374330e2 3265
51470298 3266 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3267 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3268 &ssh_3des);
371e569c 3269 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3270 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3271 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3272
0183b242 3273 ssh->crcda_ctx = crcda_make_context();
3274 logevent("Installing CRC compensation attack detector");
3275
679539d7 3276 if (servkey.modulus) {
3277 sfree(servkey.modulus);
3278 servkey.modulus = NULL;
3279 }
3280 if (servkey.exponent) {
3281 sfree(servkey.exponent);
3282 servkey.exponent = NULL;
3283 }
3284 if (hostkey.modulus) {
3285 sfree(hostkey.modulus);
3286 hostkey.modulus = NULL;
3287 }
3288 if (hostkey.exponent) {
3289 sfree(hostkey.exponent);
3290 hostkey.exponent = NULL;
3291 }
ff3187f6 3292 crWaitUntil(pktin);
374330e2 3293
ff3187f6 3294 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3295 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3296 crStop(0);
8d5de777 3297 }
374330e2 3298
c5e9c988 3299 logevent("Successfully started encryption");
3300
edd0cb8a 3301 fflush(stdout); /* FIXME eh? */
374330e2 3302 {
aa09f7d0 3303 if (!*ssh->cfg.username) {
edd0cb8a 3304 int ret; /* need not be kept over crReturn */
3305 s->cur_prompt = new_prompts(ssh->frontend);
3306 s->cur_prompt->to_server = TRUE;
3307 s->cur_prompt->name = dupstr("SSH login name");
3308 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
3309 lenof(s->username));
3310 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3311 while (ret < 0) {
51470298 3312 ssh->send_ok = 1;
edd0cb8a 3313 crWaitUntil(!pktin);
3314 ret = get_userpass_input(s->cur_prompt, in, inlen);
3315 ssh->send_ok = 0;
3316 }
3317 if (!ret) {
3318 /*
3319 * Failed to get a username. Terminate.
3320 */
3321 free_prompts(s->cur_prompt);
3322 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3323 crStop(0);
32874aea 3324 }
edd0cb8a 3325 memcpy(s->username, s->cur_prompt->prompts[0]->result,
3326 lenof(s->username));
3327 free_prompts(s->cur_prompt);
32874aea 3328 } else {
86916870 3329 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 3330 s->username[sizeof(s->username)-1] = '\0';
374330e2 3331 }
fb09bf1c 3332
51470298 3333 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 3334 {
edd0cb8a 3335 char *userlog = dupprintf("Sent username \"%s\"", s->username);
c5e9c988 3336 logevent(userlog);
32874aea 3337 if (flags & FLAG_INTERACTIVE &&
3338 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
51470298 3339 c_write_str(ssh, userlog);
edd0cb8a 3340 c_write_str(ssh, "\r\n");
3c8e959b 3341 }
edd0cb8a 3342 sfree(userlog);
c5e9c988 3343 }
374330e2 3344 }
3345
ff3187f6 3346 crWaitUntil(pktin);
374330e2 3347
d5b2c841 3348 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
0df73905 3349 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3350 s->tried_publickey = s->tried_agent = 1;
0df73905 3351 } else {
51470298 3352 s->tried_publickey = s->tried_agent = 0;
0df73905 3353 }
51470298 3354 s->tis_auth_refused = s->ccard_auth_refused = 0;
edd0cb8a 3355 /*
3356 * Load the public half of any configured keyfile for later use.
3357 */
9a30e26b 3358 if (!filename_is_null(ssh->cfg.keyfile)) {
edd0cb8a 3359 int keytype;
3360 logeventf(ssh, "Reading private key file \"%.150s\"",
3361 filename_to_str(&ssh->cfg.keyfile));
3362 keytype = key_type(&ssh->cfg.keyfile);
3363 if (keytype == SSH_KEYTYPE_SSH1) {
3364 const char *error;
3365 if (rsakey_pubblob(&ssh->cfg.keyfile,
3366 &s->publickey_blob, &s->publickey_bloblen,
3367 &s->publickey_comment, &error)) {
3368 s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
3369 NULL);
3370 } else {
3371 char *msgbuf;
3372 logeventf(ssh, "Unable to load private key (%s)", error);
3373 msgbuf = dupprintf("Unable to load private key file "
3374 "\"%.150s\" (%s)\r\n",
3375 filename_to_str(&ssh->cfg.keyfile),
3376 error);
3377 c_write_str(ssh, msgbuf);
3378 sfree(msgbuf);
3379 s->publickey_blob = NULL;
3380 }
3381 } else {
3382 char *msgbuf;
3383 logeventf(ssh, "Unable to use this key file (%s)",
3384 key_type_to_str(keytype));
3385 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3386 " (%s)\r\n",
3387 filename_to_str(&ssh->cfg.keyfile),
3388 key_type_to_str(keytype));
3389 c_write_str(ssh, msgbuf);
3390 sfree(msgbuf);
51470298 3391 s->publickey_blob = NULL;
edd0cb8a 3392 }
396778f1 3393 } else
51470298 3394 s->publickey_blob = NULL;
7cca0d81 3395
ff3187f6 3396 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3397 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3398
973612f5 3399 if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
32874aea 3400 /*
3401 * Attempt RSA authentication using Pageant.
3402 */
32874aea 3403 void *r;
3404
51470298 3405 s->authed = FALSE;
3406 s->tried_agent = 1;
32874aea 3407 logevent("Pageant is running. Requesting keys.");
3408
3409 /* Request the keys held by the agent. */
51470298 3410 PUT_32BIT(s->request, 1);
3411 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3412 if (!agent_query(s->request, 5, &r, &s->responselen,
3413 ssh_agent_callback, ssh)) {
3414 do {
3415 crReturn(0);
ff3187f6 3416 if (pktin) {
839f10db 3417 bombout(("Unexpected data from server while waiting"
3418 " for agent response"));
3419 crStop(0);
3420 }
ff3187f6 3421 } while (pktin || inlen > 0);
839f10db 3422 r = ssh->agent_response;
3423 s->responselen = ssh->agent_response_len;
3424 }
51470298 3425 s->response = (unsigned char *) r;
3426 if (s->response && s->responselen >= 5 &&
3427 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3428 s->p = s->response + 5;
3429 s->nkeys = GET_32BIT(s->p);
3430 s->p += 4;
2e85c969 3431 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
51470298 3432 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
94cd7c3a 3433 unsigned char *pkblob = s->p;
51470298 3434 s->p += 4;
0016d70b 3435 {
3436 int n, ok = FALSE;
3437 do { /* do while (0) to make breaking easy */
3438 n = ssh1_read_bignum
3439 (s->p, s->responselen-(s->p-s->response),
3440 &s->key.exponent);
3441 if (n < 0)
3442 break;
3443 s->p += n;
3444 n = ssh1_read_bignum
3445 (s->p, s->responselen-(s->p-s->response),
3446 &s->key.modulus);
3447 if (n < 0)
3448 break;
3449 s->p += n;
3450 if (s->responselen - (s->p-s->response) < 4)
3451 break;
3452 s->commentlen = GET_32BIT(s->p);
3453 s->p += 4;
3454 if (s->responselen - (s->p-s->response) <
3455 s->commentlen)
3456 break;
3457 s->commentp = (char *)s->p;
3458 s->p += s->commentlen;
3459 ok = TRUE;
3460 } while (0);
3461 if (!ok) {
3462 logevent("Pageant key list packet was truncated");
3463 break;
3464 }
3465 }
94cd7c3a 3466 if (s->publickey_blob) {
3467 if (!memcmp(pkblob, s->publickey_blob,
3468 s->publickey_bloblen)) {
3469 logeventf(ssh, "Pageant key #%d matches "
3470 "configured key file", s->keyi);
3471 s->tried_publickey = 1;
3472 } else
3473 /* Skip non-configured key */
3474 continue;
3475 }
3476 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3477 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3478 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3479 crWaitUntil(pktin);
3480 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3481 logevent("Key refused");
3482 continue;
3483 }
3484 logevent("Received RSA challenge");
ff3187f6 3485 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3486 bombout(("Server's RSA challenge was badly formatted"));
3487 crStop(0);
3488 }
3489
32874aea 3490 {
3491 char *agentreq, *q, *ret;
2d466ffd 3492 void *vret;
32874aea 3493 int len, retlen;
3494 len = 1 + 4; /* message type, bit count */
51470298 3495 len += ssh1_bignum_length(s->key.exponent);
3496 len += ssh1_bignum_length(s->key.modulus);
3497 len += ssh1_bignum_length(s->challenge);
32874aea 3498 len += 16; /* session id */
3499 len += 4; /* response format */
3d88e64d 3500 agentreq = snewn(4 + len, char);
32874aea 3501 PUT_32BIT(agentreq, len);
3502 q = agentreq + 4;
3503 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3504 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3505 q += 4;
51470298 3506 q += ssh1_write_bignum(q, s->key.exponent);
3507 q += ssh1_write_bignum(q, s->key.modulus);
3508 q += ssh1_write_bignum(q, s->challenge);
3509 memcpy(q, s->session_id, 16);
32874aea 3510 q += 16;
3511 PUT_32BIT(q, 1); /* response format */
839f10db 3512 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3513 ssh_agent_callback, ssh)) {
3514 sfree(agentreq);
3515 do {
3516 crReturn(0);
ff3187f6 3517 if (pktin) {
839f10db 3518 bombout(("Unexpected data from server"
3519 " while waiting for agent"
3520 " response"));
3521 crStop(0);
3522 }
ff3187f6 3523 } while (pktin || inlen > 0);
839f10db 3524 vret = ssh->agent_response;
3525 retlen = ssh->agent_response_len;
3526 } else
3527 sfree(agentreq);
2d466ffd 3528 ret = vret;
32874aea 3529 if (ret) {
3530 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3531 logevent("Sending Pageant's response");
51470298 3532 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3533 PKT_DATA, ret + 5, 16,
3534 PKT_END);
3535 sfree(ret);
ff3187f6 3536 crWaitUntil(pktin);
3537 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3538 logevent
3539 ("Pageant's response accepted");
3540 if (flags & FLAG_VERBOSE) {
51470298 3541 c_write_str(ssh, "Authenticated using"
3542 " RSA key \"");
3543 c_write(ssh, s->commentp,
3544 s->commentlen);
3545 c_write_str(ssh, "\" from agent\r\n");
32874aea 3546 }
51470298 3547 s->authed = TRUE;
32874aea 3548 } else
3549 logevent
3550 ("Pageant's response not accepted");
3551 } else {
3552 logevent
3553 ("Pageant failed to answer challenge");
3554 sfree(ret);
3555 }
3556 } else {
3557 logevent("No reply received from Pageant");
3558 }
3559 }
51470298 3560 freebn(s->key.exponent);
3561 freebn(s->key.modulus);
3562 freebn(s->challenge);
3563 if (s->authed)
32874aea 3564 break;
3565 }
29b1d0b3 3566 sfree(s->response);
94cd7c3a 3567 if (s->publickey_blob && !s->tried_publickey)
3568 logevent("Configured key file not in Pageant");
32874aea 3569 }
51470298 3570 if (s->authed)
32874aea 3571 break;
3572 }
edd0cb8a 3573 if (s->publickey_blob && !s->tried_publickey) {
3574 /*
3575 * Try public key authentication with the specified
3576 * key file.
3577 */
3578 int got_passphrase; /* need not be kept over crReturn */
3579 if (flags & FLAG_VERBOSE)
3580 c_write_str(ssh, "Trying public key authentication.\r\n");
3581 logeventf(ssh, "Trying public key \"%s\"",
3582 filename_to_str(&ssh->cfg.keyfile));
3583 s->tried_publickey = 1;
3584 got_passphrase = FALSE;
3585 while (!got_passphrase) {
3586 /*
3587 * Get a passphrase, if necessary.
3588 */
3589 char *passphrase = NULL; /* only written after crReturn */
3590 const char *error;
3591 if (!s->publickey_encrypted) {
3592 if (flags & FLAG_VERBOSE)
3593 c_write_str(ssh, "No passphrase required.\r\n");
3594 passphrase = NULL;
3595 } else {
3596 int ret; /* need not be kept over crReturn */
3597 s->cur_prompt = new_prompts(ssh->frontend);
3598 s->cur_prompt->to_server = FALSE;
3599 s->cur_prompt->name = dupstr("SSH key passphrase");
3600 add_prompt(s->cur_prompt,
3601 dupprintf("Passphrase for key \"%.100s\": ",
3602 s->publickey_comment),
3603 FALSE, SSH_MAX_PASSWORD_LEN);
3604 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3605 while (ret < 0) {
3606 ssh->send_ok = 1;
3607 crWaitUntil(!pktin);
3608 ret = get_userpass_input(s->cur_prompt, in, inlen);
3609 ssh->send_ok = 0;
3610 }
3611 if (!ret) {
3612 /* Failed to get a passphrase. Terminate. */
3613 free_prompts(s->cur_prompt);
3614 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3615 0, TRUE);
3616 crStop(0);
3617 }
3618 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3619 free_prompts(s->cur_prompt);
3620 }
3621 /*
3622 * Try decrypting key with passphrase.
3623 */
3624 ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
3625 &error);
3626 if (passphrase) {
3627 memset(passphrase, 0, strlen(passphrase));
3628 sfree(passphrase);
3629 }
3630 if (ret == 1) {
3631 /* Correct passphrase. */
3632 got_passphrase = TRUE;
3633 } else if (ret == 0) {
3634 c_write_str(ssh, "Couldn't load private key from ");
3635 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3636 c_write_str(ssh, " (");
3637 c_write_str(ssh, error);
3638 c_write_str(ssh, ").\r\n");
3639 got_passphrase = FALSE;
3640 break; /* go and try something else */
3641 } else if (ret == -1) {
3642 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
edd0cb8a 3643 got_passphrase = FALSE;
3644 /* and try again */
43536490 3645 } else {
3646 assert(0 && "unexpected return from loadrsakey()");
edc23a8a 3647 got_passphrase = FALSE; /* placate optimisers */
edd0cb8a 3648 }
3649 }
3650
3651 if (got_passphrase) {
3652
3653 /*
3654 * Send a public key attempt.
3655 */
3656 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3657 PKT_BIGNUM, s->key.modulus, PKT_END);
3658
3659 crWaitUntil(pktin);
3660 if (pktin->type == SSH1_SMSG_FAILURE) {
3661 c_write_str(ssh, "Server refused our public key.\r\n");
7b575324 3662 continue; /* go and try something else */
edd0cb8a 3663 }
3664 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3665 bombout(("Bizarre response to offer of public key"));
3666 crStop(0);
3667 }
3668
3669 {
3670 int i;
3671 unsigned char buffer[32];
3672 Bignum challenge, response;
3673
3674 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3675 bombout(("Server's RSA challenge was badly formatted"));
3676 crStop(0);
3677 }
3678 response = rsadecrypt(challenge, &s->key);
3679 freebn(s->key.private_exponent);/* burn the evidence */
3680
3681 for (i = 0; i < 32; i++) {
3682 buffer[i] = bignum_byte(response, 31 - i);
3683 }
3684
3685 MD5Init(&md5c);
3686 MD5Update(&md5c, buffer, 32);
3687 MD5Update(&md5c, s->session_id, 16);
3688 MD5Final(buffer, &md5c);
3689
3690 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3691 PKT_DATA, buffer, 16, PKT_END);
3692
3693 freebn(challenge);
3694 freebn(response);
3695 }
3696
3697 crWaitUntil(pktin);
3698 if (pktin->type == SSH1_SMSG_FAILURE) {
3699 if (flags & FLAG_VERBOSE)
3700 c_write_str(ssh, "Failed to authenticate with"
3701 " our public key.\r\n");
7b575324 3702 continue; /* go and try something else */
edd0cb8a 3703 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3704 bombout(("Bizarre response to RSA authentication response"));
3705 crStop(0);
3706 }
3707
3708 break; /* we're through! */
3709 }
3710
3711 }
3712
3713 /*
3714 * Otherwise, try various forms of password-like authentication.
3715 */
3716 s->cur_prompt = new_prompts(ssh->frontend);
32874aea 3717
86916870 3718 if (ssh->cfg.try_tis_auth &&
51470298 3719 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3720 !s->tis_auth_refused) {
3721 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3722 logevent("Requested TIS authentication");
51470298 3723 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3724 crWaitUntil(pktin);
3725 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3726 logevent("TIS authentication declined");
3727 if (flags & FLAG_INTERACTIVE)
51470298 3728 c_write_str(ssh, "TIS authentication refused.\r\n");
3729 s->tis_auth_refused = 1;
614a20a0 3730 continue;
32874aea 3731 } else {
0016d70b 3732 char *challenge;
3733 int challengelen;
edd0cb8a 3734 char *instr_suf, *prompt;
0016d70b 3735
ff3187f6 3736 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3737 if (!challenge) {
3738 bombout(("TIS challenge packet was badly formed"));
3739 crStop(0);
3740 }
32874aea 3741 logevent("Received TIS challenge");
edd0cb8a 3742 s->cur_prompt->to_server = TRUE;
3743 s->cur_prompt->name = dupstr("SSH TIS authentication");
614a20a0 3744 /* Prompt heuristic comes from OpenSSH */
edd0cb8a 3745 if (memchr(challenge, '\n', challengelen)) {
3746 instr_suf = dupstr("");
3747 prompt = dupprintf("%.*s", challengelen, challenge);
3748 } else {
3749 instr_suf = dupprintf("%.*s", challengelen, challenge);
3750 prompt = dupstr("Response: ");
3751 }
3752 s->cur_prompt->instruction =
3753 dupprintf("Using TIS authentication.%s%s",
3754 (*instr_suf) ? "\n" : "",
3755 instr_suf);
3756 s->cur_prompt->instr_reqd = TRUE;
3757 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3758 sfree(instr_suf);
32874aea 3759 }
3760 }
86916870 3761 if (ssh->cfg.try_tis_auth &&
51470298 3762 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3763 !s->ccard_auth_refused) {
3764 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3765 logevent("Requested CryptoCard authentication");
51470298 3766 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3767 crWaitUntil(pktin);
3768 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3769 logevent("CryptoCard authentication declined");
51470298 3770 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3771 s->ccard_auth_refused = 1;
614a20a0 3772 continue;
32874aea 3773 } else {
0016d70b 3774 char *challenge;
3775 int challengelen;
edd0cb8a 3776 char *instr_suf, *prompt;
0016d70b 3777
ff3187f6 3778 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3779 if (!challenge) {
3780 bombout(("CryptoCard challenge packet was badly formed"));
3781 crStop(0);
3782 }
32874aea 3783 logevent("Received CryptoCard challenge");
edd0cb8a 3784 s->cur_prompt->to_server = TRUE;
3785 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
3786 s->cur_prompt->name_reqd = FALSE;
3787 /* Prompt heuristic comes from OpenSSH */
3788 if (memchr(challenge, '\n', challengelen)) {
3789 instr_suf = dupstr("");
3790 prompt = dupprintf("%.*s", challengelen, challenge);
3791 } else {
3792 instr_suf = dupprintf("%.*s", challengelen, challenge);
3793 prompt = dupstr("Response: ");
3794 }
3795 s->cur_prompt->instruction =
3796 dupprintf("Using CryptoCard authentication.%s%s",
3797 (*instr_suf) ? "\n" : "",
3798 instr_suf);
3799 s->cur_prompt->instr_reqd = TRUE;
3800 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3801 sfree(instr_suf);
32874aea 3802 }
3803 }
51470298 3804 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
8f9e3231 3805 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
3806 bombout(("No supported authentication methods available"));
3807 crStop(0);
3808 }
edd0cb8a 3809 s->cur_prompt->to_server = TRUE;
3810 s->cur_prompt->name = dupstr("SSH password");
3811 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
3812 s->username, ssh->savedhost),
3813 FALSE, SSH_MAX_PASSWORD_LEN);
32874aea 3814 }
a52f067e 3815
614a20a0 3816 /*
3817 * Show password prompt, having first obtained it via a TIS
3818 * or CryptoCard exchange if we're doing TIS or CryptoCard
3819 * authentication.
3820 */
edd0cb8a 3821 {
3822 int ret; /* need not be kept over crReturn */
3823 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3824 while (ret < 0) {
3825 ssh->send_ok = 1;
3826 crWaitUntil(!pktin);
3827 ret = get_userpass_input(s->cur_prompt, in, inlen);
3828 ssh->send_ok = 0;
3829 }
3830 if (!ret) {
32874aea 3831 /*
edd0cb8a 3832 * Failed to get a password (for example
32874aea 3833 * because one was supplied on the command line
3834 * which has already failed to work). Terminate.
3835 */
edd0cb8a 3836 free_prompts(s->cur_prompt);
3837 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
3838 crStop(0);
32874aea 3839 }
32874aea 3840 }
3841
edd0cb8a 3842 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3843 /*
edd0cb8a 3844 * Defence against traffic analysis: we send a
3845 * whole bunch of packets containing strings of
3846 * different lengths. One of these strings is the
3847 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3848 * The others are all random data in
3849 * SSH1_MSG_IGNORE packets. This way a passive
3850 * listener can't tell which is the password, and
3851 * hence can't deduce the password length.
3852 *
3853 * Anybody with a password length greater than 16
3854 * bytes is going to have enough entropy in their
3855 * password that a listener won't find it _that_
3856 * much help to know how long it is. So what we'll
3857 * do is:
3858 *
3859 * - if password length < 16, we send 15 packets
3860 * containing string lengths 1 through 15
3861 *
3862 * - otherwise, we let N be the nearest multiple
3863 * of 8 below the password length, and send 8
3864 * packets containing string lengths N through
3865 * N+7. This won't obscure the order of
3866 * magnitude of the password length, but it will
3867 * introduce a bit of extra uncertainty.
3868 *
bf982899 3869 * A few servers can't deal with SSH1_MSG_IGNORE, at
3870 * least in this context. For these servers, we need
3871 * an alternative defence. We make use of the fact
3872 * that the password is interpreted as a C string:
3873 * so we can append a NUL, then some random data.
edd0cb8a 3874 *
bf982899 3875 * A few servers can deal with neither SSH1_MSG_IGNORE
3876 * here _nor_ a padded password string.
3877 * For these servers we are left with no defences
edd0cb8a 3878 * against password length sniffing.
32874aea 3879 */
bf982899 3880 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
3881 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
32874aea 3882 /*
edd0cb8a 3883 * The server can deal with SSH1_MSG_IGNORE, so
3884 * we can use the primary defence.
32874aea 3885 */
edd0cb8a 3886 int bottom, top, pwlen, i;
3887 char *randomstr;
32874aea 3888
edd0cb8a 3889 pwlen = strlen(s->cur_prompt->prompts[0]->result);
3890 if (pwlen < 16) {
3891 bottom = 0; /* zero length passwords are OK! :-) */
3892 top = 15;
3893 } else {
3894 bottom = pwlen & ~7;
3895 top = bottom + 7;
3896 }
32874aea 3897
edd0cb8a 3898 assert(pwlen >= bottom && pwlen <= top);
32874aea 3899
edd0cb8a 3900 randomstr = snewn(top + 1, char);
32874aea 3901
edd0cb8a 3902 for (i = bottom; i <= top; i++) {
3903 if (i == pwlen) {
3904 defer_packet(ssh, s->pwpkt_type,
3905 PKTT_PASSWORD, PKT_STR,
3906 s->cur_prompt->prompts[0]->result,
3907 PKTT_OTHER, PKT_END);
3908 } else {
3909 for (j = 0; j < i; j++) {
3910 do {
3911 randomstr[j] = random_byte();
3912 } while (randomstr[j] == '\0');
32874aea 3913 }
edd0cb8a 3914 randomstr[i] = '\0';
3915 defer_packet(ssh, SSH1_MSG_IGNORE,
3916 PKT_STR, randomstr, PKT_END);
32874aea 3917 }
edd0cb8a 3918 }
3919 logevent("Sending password with camouflage packets");
3920 ssh_pkt_defersend(ssh);
3921 sfree(randomstr);
3922 }
3923 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3924 /*
3925 * The server can't deal with SSH1_MSG_IGNORE
3926 * but can deal with padded passwords, so we
3927 * can use the secondary defence.
3928 */
3929 char string[64];
3930 char *ss;
3931 int len;
3932
3933 len = strlen(s->cur_prompt->prompts[0]->result);
3934 if (len < sizeof(string)) {
3935 ss = string;
3936 strcpy(string, s->cur_prompt->prompts[0]->result);
3937 len++; /* cover the zero byte */
3938 while (len < sizeof(string)) {
3939 string[len++] = (char) random_byte();
bd358db1 3940 }
bd358db1 3941 } else {
edd0cb8a 3942 ss = s->cur_prompt->prompts[0]->result;
32874aea 3943 }
edd0cb8a 3944 logevent("Sending length-padded password");
9a10ecf4 3945 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
edd0cb8a 3946 PKT_INT, len, PKT_DATA, ss, len,
3947 PKTT_OTHER, PKT_END);
3948 } else {
3949 /*
bf982899 3950 * The server is believed unable to cope with
3951 * any of our password camouflage methods.
edd0cb8a 3952 */
3953 int len;
3954 len = strlen(s->cur_prompt->prompts[0]->result);
3955 logevent("Sending unpadded password");
3956 send_packet(ssh, s->pwpkt_type,
3957 PKTT_PASSWORD, PKT_INT, len,
3958 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
3959 PKTT_OTHER, PKT_END);
32874aea 3960 }
edd0cb8a 3961 } else {
3962 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3963 PKT_STR, s->cur_prompt->prompts[0]->result,
3964 PKTT_OTHER, PKT_END);
32874aea 3965 }
c5e9c988 3966 logevent("Sent password");
edd0cb8a 3967 free_prompts(s->cur_prompt);
ff3187f6 3968 crWaitUntil(pktin);
3969 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3970 if (flags & FLAG_VERBOSE)
51470298 3971 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3972 logevent("Authentication refused");
ff3187f6 3973 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3974 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3975 crStop(0);
374330e2 3976 }
3977 }
3978
edd0cb8a 3979 /* Clear up */
3980 if (s->publickey_blob) {
3981 sfree(s->publickey_blob);
3982 sfree(s->publickey_comment);
3983 }
3984
c5e9c988 3985 logevent("Authentication successful");
3986
fb09bf1c 3987 crFinish(1);
3988}
3989
32874aea 3990void sshfwd_close(struct ssh_channel *c)
3991{
51470298 3992 Ssh ssh = c->ssh;
3993
1ef619ae 3994 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 3995 return;
36f94d1f 3996
80e48603 3997 if (c && !c->closes) {
4ed34d25 3998 /*
64d6ff88 3999 * If halfopen is true, we have sent
4ed34d25 4000 * CHANNEL_OPEN for this channel, but it hasn't even been
4001 * acknowledged by the server. So we must set a close flag
4002 * on it now, and then when the server acks the channel
4003 * open, we can close it then.
4004 */
64d6ff88 4005 if (!c->halfopen) {
51470298 4006 if (ssh->version == 1) {
4007 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 4008 PKT_END);
4009 } else {
ff3187f6 4010 struct Packet *pktout;
4011 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4012 ssh2_pkt_adduint32(pktout, c->remoteid);
4013 ssh2_pkt_send(ssh, pktout);
4ed34d25 4014 }
32874aea 4015 }
0357890f 4016 c->closes = 1; /* sent MSG_CLOSE */
32874aea 4017 if (c->type == CHAN_X11) {
4018 c->u.x11.s = NULL;
d74d141c 4019 logevent("Forwarded X11 connection terminated");
4ed34d25 4020 } else if (c->type == CHAN_SOCKDATA ||
4021 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 4022 c->u.pfd.s = NULL;
4023 logevent("Forwarded port closed");
32874aea 4024 }
4025 }
4026}
4027
5471d09a 4028int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 4029{
51470298 4030 Ssh ssh = c->ssh;
4031
1ef619ae 4032 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4033 return 0;
36f94d1f 4034
51470298 4035 if (ssh->version == 1) {
4036 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 4037 PKT_INT, c->remoteid,
a2724fba 4038 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
9a10ecf4 4039 PKTT_OTHER, PKT_END);
5471d09a 4040 /*
2e85c969 4041 * In SSH-1 we can return 0 here - implying that forwarded
5471d09a 4042 * connections are never individually throttled - because
4043 * the only circumstance that can cause throttling will be
4044 * the whole SSH connection backing up, in which case
4045 * _everything_ will be throttled as a whole.
4046 */
4047 return 0;
783415f8 4048 } else {
32874aea 4049 ssh2_add_channel_data(c, buf, len);
5471d09a 4050 return ssh2_try_send(c);
4051 }
4052}
4053
4054void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4055{
51470298 4056 Ssh ssh = c->ssh;
4057
1ef619ae 4058 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 4059 return;
36f94d1f 4060
51470298 4061 if (ssh->version == 1) {
5471d09a 4062 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
4063 c->v.v1.throttling = 0;
51470298 4064 ssh1_throttle(ssh, -1);
5471d09a 4065 }
4066 } else {
9b53e9b8 4067 ssh2_set_window(c, c->v.v2.locmaxwin - bufsize);
783415f8 4068 }
9c964e85 4069}
4070
06fadff5 4071static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4072{
4073 struct queued_handler *qh = ssh->qhead;
4074
4075 assert(qh != NULL);
4076
4077 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4078
4079 if (qh->msg1 > 0) {
4080 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4081 ssh->packet_dispatch[qh->msg1] = NULL;
4082 }
4083 if (qh->msg2 > 0) {
4084 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4085 ssh->packet_dispatch[qh->msg2] = NULL;
4086 }
4087
4088 if (qh->next) {
4089 ssh->qhead = qh->next;
4090
4091 if (ssh->qhead->msg1 > 0) {
4092 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4093 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4094 }
4095 if (ssh->qhead->msg2 > 0) {
4096 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4097 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4098 }
4099 } else {
4100 ssh->qhead = ssh->qtail = NULL;
4101 ssh->packet_dispatch[pktin->type] = NULL;
4102 }
4103
4104 qh->handler(ssh, pktin, qh->ctx);
4105
4106 sfree(qh);
4107}
4108
4109static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4110 chandler_fn_t handler, void *ctx)
4111{
4112 struct queued_handler *qh;
4113
4114 qh = snew(struct queued_handler);
4115 qh->msg1 = msg1;
4116 qh->msg2 = msg2;
4117 qh->handler = handler;
4118 qh->ctx = ctx;
4119 qh->next = NULL;
4120
4121 if (ssh->qtail == NULL) {
4122 ssh->qhead = qh;
4123
4124 if (qh->msg1 > 0) {
4125 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4126 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4127 }
4128 if (qh->msg2 > 0) {
4129 assert(ssh->packet_dispatch[qh->msg2] == NULL);
4130 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4131 }
4132 } else {
4133 ssh->qtail->next = qh;
4134 }
4135 ssh->qtail = qh;
4136}
4137
4138static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4139{
4140 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4141
4142 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4143 SSH2_MSG_REQUEST_SUCCESS)) {
4144 logeventf(ssh, "Remote port forwarding from %s enabled",
4145 pf->sportdesc);
4146 } else {
4147 logeventf(ssh, "Remote port forwarding from %s refused",
4148 pf->sportdesc);
4149
4150 rpf = del234(ssh->rportfwds, pf);
4151 assert(rpf == pf);
fda2feb1 4152 free_rportfwd(pf);
06fadff5 4153 }
4154}
4155
4156static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
4157{
84328ddb 4158 const char *portfwd_strptr = cfg->portfwd;
4159 struct ssh_portfwd *epf;
4160 int i;
06fadff5 4161
fda2feb1 4162 if (!ssh->portfwds) {
4163 ssh->portfwds = newtree234(ssh_portcmp);
4164 } else {
4165 /*
4166 * Go through the existing port forwardings and tag them
84328ddb 4167 * with status==DESTROY. Any that we want to keep will be
4168 * re-enabled (status==KEEP) as we go through the
4169 * configuration and find out which bits are the same as
4170 * they were before.
fda2feb1 4171 */
4172 struct ssh_portfwd *epf;
4173 int i;
4174 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 4175 epf->status = DESTROY;
fda2feb1 4176 }
4177
06fadff5 4178 while (*portfwd_strptr) {
84328ddb 4179 char address_family, type;
4180 int sport,dport,sserv,dserv;
4181 char sports[256], dports[256], saddr[256], host[256];
4182 int n;
4183
05581745 4184 address_family = 'A';
4185 type = 'L';
84328ddb 4186 if (*portfwd_strptr == 'A' ||
4187 *portfwd_strptr == '4' ||
4188 *portfwd_strptr == '6')
4189 address_family = *portfwd_strptr++;
4190 if (*portfwd_strptr == 'L' ||
4191 *portfwd_strptr == 'R' ||
4192 *portfwd_strptr == 'D')
4193 type = *portfwd_strptr++;
05581745 4194
06fadff5 4195 saddr[0] = '\0';
05581745 4196
06fadff5 4197 n = 0;
4198 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4199 if (*portfwd_strptr == ':') {
4200 /*
4201 * We've seen a colon in the middle of the
4202 * source port number. This means that
4203 * everything we've seen until now is the
4204 * source _address_, so we'll move it into
4205 * saddr and start sports from the beginning
4206 * again.
4207 */
4208 portfwd_strptr++;
4209 sports[n] = '\0';
4210 if (ssh->version == 1 && type == 'R') {
2e85c969 4211 logeventf(ssh, "SSH-1 cannot handle remote source address "
06fadff5 4212 "spec \"%s\"; ignoring", sports);
4213 } else
4214 strcpy(saddr, sports);
4215 n = 0;
4216 }
019164b0 4217 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
06fadff5 4218 }
4219 sports[n] = 0;
4220 if (type != 'D') {
4221 if (*portfwd_strptr == '\t')
4222 portfwd_strptr++;
4223 n = 0;
4224 while (*portfwd_strptr && *portfwd_strptr != ':') {
019164b0 4225 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
06fadff5 4226 }
4227 host[n] = 0;
4228 if (*portfwd_strptr == ':')
4229 portfwd_strptr++;
4230 n = 0;
4231 while (*portfwd_strptr) {
019164b0 4232 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
06fadff5 4233 }
4234 dports[n] = 0;
4235 portfwd_strptr++;
4236 dport = atoi(dports);
4237 dserv = 0;
4238 if (dport == 0) {
4239 dserv = 1;
4240 dport = net_service_lookup(dports);
4241 if (!dport) {
4242 logeventf(ssh, "Service lookup failed for destination"
4243 " port \"%s\"", dports);
4244 }
4245 }
4246 } else {
4247 while (*portfwd_strptr) portfwd_strptr++;
a9e72926 4248 host[0] = 0;
4249 dports[0] = 0;
06fadff5 4250 dport = dserv = -1;
4251 portfwd_strptr++; /* eat the NUL and move to next one */
4252 }
4253 sport = atoi(sports);
4254 sserv = 0;
4255 if (sport == 0) {
4256 sserv = 1;
4257 sport = net_service_lookup(sports);
4258 if (!sport) {
4259 logeventf(ssh, "Service lookup failed for source"
4260 " port \"%s\"", sports);
4261 }
4262 }
4263 if (sport && dport) {
4264 /* Set up a description of the source port. */
fda2feb1 4265 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 4266
4267 pfrec = snew(struct ssh_portfwd);
4268 pfrec->type = type;
4269 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 4270 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 4271 pfrec->sport = sport;
84328ddb 4272 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 4273 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 4274 pfrec->dport = dport;
4275 pfrec->local = NULL;
4276 pfrec->remote = NULL;
05581745 4277 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4278 address_family == '6' ? ADDRTYPE_IPV6 :
4279 ADDRTYPE_UNSPEC);
fda2feb1 4280
4281 epfrec = add234(ssh->portfwds, pfrec);
4282 if (epfrec != pfrec) {
4283 /*
4284 * We already have a port forwarding with precisely
4285 * these parameters. Hence, no need to do anything;
84328ddb 4286 * simply tag the existing one as KEEP.
fda2feb1 4287 */
84328ddb 4288 epfrec->status = KEEP;
fda2feb1 4289 free_portfwd(pfrec);
84328ddb 4290 } else {
4291 pfrec->status = CREATE;
4292 }
4293 }
4294 }
4295
4296 /*
4297 * Now go through and destroy any port forwardings which were
4298 * not re-enabled.
4299 */
4300 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4301 if (epf->status == DESTROY) {
4302 char *message;
4303
4304 message = dupprintf("%s port forwarding from %s%s%d",
4305 epf->type == 'L' ? "local" :
4306 epf->type == 'R' ? "remote" : "dynamic",
4307 epf->saddr ? epf->saddr : "",
4308 epf->saddr ? ":" : "",
4309 epf->sport);
4310
4311 if (epf->type != 'D') {
4312 char *msg2 = dupprintf("%s to %s:%d", message,
4313 epf->daddr, epf->dport);
4314 sfree(message);
4315 message = msg2;
4316 }
4317
4318 logeventf(ssh, "Cancelling %s", message);
4319 sfree(message);
4320
4321 if (epf->remote) {
4322 struct ssh_rportfwd *rpf = epf->remote;
4323 struct Packet *pktout;
4324
4325 /*
4326 * Cancel the port forwarding at the server
4327 * end.
4328 */
4329 if (ssh->version == 1) {
4330 /*
4331 * We cannot cancel listening ports on the
2e85c969 4332 * server side in SSH-1! There's no message
84328ddb 4333 * to support it. Instead, we simply remove
4334 * the rportfwd record from the local end
4335 * so that any connections the server tries
4336 * to make on it are rejected.
4337 */
4338 } else {
4339 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4340 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4341 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4342 if (epf->saddr) {
4343 ssh2_pkt_addstring(pktout, epf->saddr);
4344 } else if (ssh->cfg.rport_acceptall) {
5188540b 4345 /* XXX: ssh->cfg.rport_acceptall may not represent
4346 * what was used to open the original connection,
4347 * since it's reconfigurable. */
84328ddb 4348 ssh2_pkt_addstring(pktout, "0.0.0.0");
4349 } else {
4350 ssh2_pkt_addstring(pktout, "127.0.0.1");
4351 }
4352 ssh2_pkt_adduint32(pktout, epf->sport);
4353 ssh2_pkt_send(ssh, pktout);
4354 }
4355
4356 del234(ssh->rportfwds, rpf);
4357 free_rportfwd(rpf);
4358 } else if (epf->local) {
4359 pfd_terminate(epf->local);
4360 }
4361
4362 delpos234(ssh->portfwds, i);
4363 free_portfwd(epf);
4364 i--; /* so we don't skip one in the list */
4365 }
4366
4367 /*
4368 * And finally, set up any new port forwardings (status==CREATE).
4369 */
4370 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4371 if (epf->status == CREATE) {
4372 char *sportdesc, *dportdesc;
3fe92132 4373 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 4374 epf->saddr ? epf->saddr : "",
4375 epf->saddr ? ":" : "",
3fe92132 4376 epf->sserv ? epf->sserv : "",
4377 epf->sserv ? "(" : "",
4378 epf->sport,
4379 epf->sserv ? ")" : "");
84328ddb 4380 if (epf->type == 'D') {
4381 dportdesc = NULL;
4382 } else {
3fe92132 4383 dportdesc = dupprintf("%s:%s%s%d%s",
4384 epf->daddr,
4385 epf->dserv ? epf->dserv : "",
4386 epf->dserv ? "(" : "",
4387 epf->dport,
4388 epf->dserv ? ")" : "");
84328ddb 4389 }
05581745 4390
84328ddb 4391 if (epf->type == 'L') {
4392 const char *err = pfd_addforward(epf->daddr, epf->dport,
4393 epf->saddr, epf->sport,
5188540b 4394 ssh, cfg,
84328ddb 4395 &epf->local,
4396 epf->addressfamily);
4397
4398 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4399 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4400 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4401 sportdesc, dportdesc,
4402 err ? " failed: " : "", err ? err : "");
4403 } else if (epf->type == 'D') {
06fadff5 4404 const char *err = pfd_addforward(NULL, -1,
84328ddb 4405 epf->saddr, epf->sport,
5188540b 4406 ssh, cfg,
84328ddb 4407 &epf->local,
4408 epf->addressfamily);
4409
4410 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4411 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4412 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4413 sportdesc,
4414 err ? " failed: " : "", err ? err : "");
06fadff5 4415 } else {
4416 struct ssh_rportfwd *pf;
4417
4418 /*
4419 * Ensure the remote port forwardings tree exists.
4420 */
4421 if (!ssh->rportfwds) {
4422 if (ssh->version == 1)
4423 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4424 else
4425 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4426 }
4427
4428 pf = snew(struct ssh_rportfwd);
84328ddb 4429 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4430 pf->dhost[lenof(pf->dhost)-1] = '\0';
4431 pf->dport = epf->dport;
4432 pf->sport = epf->sport;
06fadff5 4433 if (add234(ssh->rportfwds, pf) != pf) {
4434 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4435 epf->daddr, epf->dport);
06fadff5 4436 sfree(pf);
4437 } else {
4438 logeventf(ssh, "Requesting remote port %s"
84328ddb 4439 " forward to %s", sportdesc, dportdesc);
06fadff5 4440
4441 pf->sportdesc = sportdesc;
4442 sportdesc = NULL;
84328ddb 4443 epf->remote = pf;
4444 pf->pfrec = epf;
06fadff5 4445
4446 if (ssh->version == 1) {
4447 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4448 PKT_INT, epf->sport,
4449 PKT_STR, epf->daddr,
4450 PKT_INT, epf->dport,
06fadff5 4451 PKT_END);
4452 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4453 SSH1_SMSG_FAILURE,
4454 ssh_rportfwd_succfail, pf);
4455 } else {
4456 struct Packet *pktout;
4457 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4458 ssh2_pkt_addstring(pktout, "tcpip-forward");
4459 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4460 if (epf->saddr) {
4461 ssh2_pkt_addstring(pktout, epf->saddr);
5188540b 4462 } else if (cfg->rport_acceptall) {
06fadff5 4463 ssh2_pkt_addstring(pktout, "0.0.0.0");
4464 } else {
4465 ssh2_pkt_addstring(pktout, "127.0.0.1");
4466 }
84328ddb 4467 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4468 ssh2_pkt_send(ssh, pktout);
4469
4470 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4471 SSH2_MSG_REQUEST_FAILURE,
4472 ssh_rportfwd_succfail, pf);
4473 }
4474 }
4475 }
4476 sfree(sportdesc);
84328ddb 4477 sfree(dportdesc);
06fadff5 4478 }
06fadff5 4479}
4480
51df0ab5 4481static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4482{
4483 char *string;
4484 int stringlen, bufsize;
4485
4486 ssh_pkt_getstring(pktin, &string, &stringlen);
4487 if (string == NULL) {
4488 bombout(("Incoming terminal data packet was badly formed"));
4489 return;
4490 }
4491
4492 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4493 string, stringlen);
4494 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4495 ssh->v1_stdout_throttling = 1;
4496 ssh1_throttle(ssh, +1);
4497 }
4498}
4499
4500static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4501{
4502 /* Remote side is trying to open a channel to talk to our
4503 * X-Server. Give them back a local channel number. */
4504 struct ssh_channel *c;
4505 int remoteid = ssh_pkt_getuint32(pktin);
4506
4507 logevent("Received X11 connect request");
4508 /* Refuse if X11 forwarding is disabled. */
4509 if (!ssh->X11_fwd_enabled) {
4510 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4511 PKT_INT, remoteid, PKT_END);
4512 logevent("Rejected X11 connect request");
4513 } else {
4514 c = snew(struct ssh_channel);
4515 c->ssh = ssh;
4516
4517 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4518 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4519 logevent("Opening X11 forward connection failed");
4520 sfree(c);
4521 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4522 PKT_INT, remoteid, PKT_END);
4523 } else {
4524 logevent
4525 ("Opening X11 forward connection succeeded");
4526 c->remoteid = remoteid;
64d6ff88 4527 c->halfopen = FALSE;
51df0ab5 4528 c->localid = alloc_channel_id(ssh);
4529 c->closes = 0;
4530 c->v.v1.throttling = 0;
4531 c->type = CHAN_X11; /* identify channel type */
4532 add234(ssh->channels, c);
4533 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4534 PKT_INT, c->remoteid, PKT_INT,
4535 c->localid, PKT_END);
4536 logevent("Opened X11 forward channel");
4537 }
4538 }
4539}
4540
4541static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4542{
4543 /* Remote side is trying to open a channel to talk to our
4544 * agent. Give them back a local channel number. */
4545 struct ssh_channel *c;
4546 int remoteid = ssh_pkt_getuint32(pktin);
4547
4548 /* Refuse if agent forwarding is disabled. */
4549 if (!ssh->agentfwd_enabled) {
4550 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4551 PKT_INT, remoteid, PKT_END);
4552 } else {
4553 c = snew(struct ssh_channel);
4554 c->ssh = ssh;
4555 c->remoteid = remoteid;
64d6ff88 4556 c->halfopen = FALSE;
51df0ab5 4557 c->localid = alloc_channel_id(ssh);
4558 c->closes = 0;
4559 c->v.v1.throttling = 0;
4560 c->type = CHAN_AGENT; /* identify channel type */
4561 c->u.a.lensofar = 0;
4562 add234(ssh->channels, c);
4563 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4564 PKT_INT, c->remoteid, PKT_INT, c->localid,
4565 PKT_END);
4566 }
4567}
4568
4569static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4570{
4571 /* Remote side is trying to open a channel to talk to a
4572 * forwarded port. Give them back a local channel number. */
4573 struct ssh_channel *c;
05581745 4574 struct ssh_rportfwd pf, *pfp;
51df0ab5 4575 int remoteid;
4576 int hostsize, port;
fb983202 4577 char *host;
51df0ab5 4578 const char *e;
4579 c = snew(struct ssh_channel);
4580 c->ssh = ssh;
4581
4582 remoteid = ssh_pkt_getuint32(pktin);
4583 ssh_pkt_getstring(pktin, &host, &hostsize);
4584 port = ssh_pkt_getuint32(pktin);
4585
4586 if (hostsize >= lenof(pf.dhost))
4587 hostsize = lenof(pf.dhost)-1;
4588 memcpy(pf.dhost, host, hostsize);
4589 pf.dhost[hostsize] = '\0';
4590 pf.dport = port;
05581745 4591 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4592
05581745 4593 if (pfp == NULL) {
fb983202 4594 logeventf(ssh, "Rejected remote port open request for %s:%d",
4595 pf.dhost, port);
51df0ab5 4596 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4597 PKT_INT, remoteid, PKT_END);
4598 } else {
fb983202 4599 logeventf(ssh, "Received remote port open request for %s:%d",
4600 pf.dhost, port);
51df0ab5 4601 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4602 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4603 if (e != NULL) {
fb983202 4604 logeventf(ssh, "Port open failed: %s", e);
51df0ab5 4605 sfree(c);
4606 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4607 PKT_INT, remoteid, PKT_END);
4608 } else {
4609 c->remoteid = remoteid;
64d6ff88 4610 c->halfopen = FALSE;
51df0ab5 4611 c->localid = alloc_channel_id(ssh);
4612 c->closes = 0;
4613 c->v.v1.throttling = 0;
4614 c->type = CHAN_SOCKDATA; /* identify channel type */
4615 add234(ssh->channels, c);
4616 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4617 PKT_INT, c->remoteid, PKT_INT,
4618 c->localid, PKT_END);
4619 logevent("Forwarded port opened successfully");
4620 }
4621 }
4622}
4623
4624static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4625{
4626 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4627 unsigned int localid = ssh_pkt_getuint32(pktin);
4628 struct ssh_channel *c;
4629
4630 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4631 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4632 c->remoteid = localid;
64d6ff88 4633 c->halfopen = FALSE;
51df0ab5 4634 c->type = CHAN_SOCKDATA;
4635 c->v.v1.throttling = 0;
4636 pfd_confirm(c->u.pfd.s);
4637 }
4638
4639 if (c && c->closes) {
4640 /*
4641 * We have a pending close on this channel,
4642 * which we decided on before the server acked
4643 * the channel open. So now we know the
4644 * remoteid, we can close it again.
4645 */
4646 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4647 PKT_INT, c->remoteid, PKT_END);
4648 }
4649}
4650
4651static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4652{
4653 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4654 struct ssh_channel *c;
4655
4656 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4657 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4658 logevent("Forwarded connection refused by server");
4659 pfd_close(c->u.pfd.s);
4660 del234(ssh->channels, c);
4661 sfree(c);
4662 }
4663}
4664
4665static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4666{
4667 /* Remote side closes a channel. */
4668 unsigned i = ssh_pkt_getuint32(pktin);
4669 struct ssh_channel *c;
4670 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 4671 if (c && !c->halfopen) {
51df0ab5 4672 int closetype;
4673 closetype =
4674 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4675
4676 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4677 logevent("Forwarded X11 connection terminated");
4678 assert(c->u.x11.s != NULL);
4679 x11_close(c->u.x11.s);
4680 c->u.x11.s = NULL;
4681 }
4682 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4683 logevent("Forwarded port closed");
4684 assert(c->u.pfd.s != NULL);
4685 pfd_close(c->u.pfd.s);
4686 c->u.pfd.s = NULL;
4687 }
4688
4689 c->closes |= (closetype << 2); /* seen this message */
4690 if (!(c->closes & closetype)) {
4691 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4692 PKT_END);
4693 c->closes |= closetype; /* sent it too */
4694 }
4695
4696 if (c->closes == 15) {
4697 del234(ssh->channels, c);
4698 sfree(c);
4699 }
4700 } else {
4701 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4702 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4703 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4704 i));
4705 }
4706}
4707
4708static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4709{
4710 /* Data sent down one of our channels. */
4711 int i = ssh_pkt_getuint32(pktin);
4712 char *p;
6d44acc9 4713 int len;
51df0ab5 4714 struct ssh_channel *c;
4715
4716 ssh_pkt_getstring(pktin, &p, &len);
4717
4718 c = find234(ssh->channels, &i, ssh_channelfind);
4719 if (c) {
4720 int bufsize = 0;
4721 switch (c->type) {
4722 case CHAN_X11:
4723 bufsize = x11_send(c->u.x11.s, p, len);
4724 break;
4725 case CHAN_SOCKDATA:
4726 bufsize = pfd_send(c->u.pfd.s, p, len);
4727 break;
4728 case CHAN_AGENT:
4729 /* Data for an agent message. Buffer it. */
4730 while (len > 0) {
4731 if (c->u.a.lensofar < 4) {
62ddb51e 4732 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
51df0ab5 4733 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4734 l);
4735 p += l;
4736 len -= l;
4737 c->u.a.lensofar += l;
4738 }
4739 if (c->u.a.lensofar == 4) {
4740 c->u.a.totallen =
4741 4 + GET_32BIT(c->u.a.msglen);
4742 c->u.a.message = snewn(c->u.a.totallen,
4743 unsigned char);
4744 memcpy(c->u.a.message, c->u.a.msglen, 4);
4745 }
4746 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4747 unsigned int l =
51df0ab5 4748 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 4749 (unsigned)len);
51df0ab5 4750 memcpy(c->u.a.message + c->u.a.lensofar, p,
4751 l);
4752 p += l;
4753 len -= l;
4754 c->u.a.lensofar += l;
4755 }
4756 if (c->u.a.lensofar == c->u.a.totallen) {
4757 void *reply;
4758 int replylen;
4759 if (agent_query(c->u.a.message,
4760 c->u.a.totallen,
4761 &reply, &replylen,
4762 ssh_agentf_callback, c))
4763 ssh_agentf_callback(c, reply, replylen);
4764 sfree(c->u.a.message);
4765 c->u.a.lensofar = 0;
4766 }
4767 }
4768 bufsize = 0; /* agent channels never back up */
4769 break;
4770 }
4771 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4772 c->v.v1.throttling = 1;
4773 ssh1_throttle(ssh, +1);
4774 }
4775 }
4776}
4777
4778static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4779{
51df0ab5 4780 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 4781 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 4782 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4783 /*
4784 * In case `helpful' firewalls or proxies tack
4785 * extra human-readable text on the end of the
4786 * session which we might mistake for another
4787 * encrypted packet, we close the session once
4788 * we've sent EXIT_CONFIRMATION.
4789 */
9e296bfa 4790 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
51df0ab5 4791}
4792
c6ccd5c2 4793/* Helper function to deal with sending tty modes for REQUEST_PTY */
4794static void ssh1_send_ttymode(void *data, char *mode, char *val)
4795{
4796 struct Packet *pktout = (struct Packet *)data;
4797 int i = 0;
4798 unsigned int arg = 0;
4799 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4800 if (i == lenof(ssh_ttymodes)) return;
4801 switch (ssh_ttymodes[i].type) {
4802 case TTY_OP_CHAR:
4803 arg = ssh_tty_parse_specchar(val);
4804 break;
4805 case TTY_OP_BOOL:
4806 arg = ssh_tty_parse_boolean(val);
4807 break;
4808 }
4809 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4810 ssh2_pkt_addbyte(pktout, arg);
4811}
4812
4813
b09eaa88 4814static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4815 struct Packet *pktin)
32874aea 4816{
b09eaa88 4817 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4818
51df0ab5 4819 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4820 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4821 ssh1_smsg_stdout_stderr_data;
4822
4823 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4824 ssh1_msg_channel_open_confirmation;
4825 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4826 ssh1_msg_channel_open_failure;
4827 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4828 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4829 ssh1_msg_channel_close;
4830 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4831 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4832
86916870 4833 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4834 logevent("Requesting agent forwarding");
51470298 4835 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4836 do {
4837 crReturnV;
ff3187f6 4838 } while (!pktin);
4839 if (pktin->type != SSH1_SMSG_SUCCESS
4840 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4841 bombout(("Protocol confusion"));
7ffdbc1a 4842 crStopV;
ff3187f6 4843 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4844 logevent("Agent forwarding refused");
4845 } else {
4846 logevent("Agent forwarding enabled");
51470298 4847 ssh->agentfwd_enabled = TRUE;
51df0ab5 4848 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4849 }
dacbd0e8 4850 }
4851
86916870 4852 if (ssh->cfg.x11_forward) {
32874aea 4853 char proto[20], data[64];
4854 logevent("Requesting X11 forwarding");
302121de 4855 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4856 data, sizeof(data), ssh->cfg.x11_auth);
4857 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
f68353be 4858 /*
4859 * Note that while we blank the X authentication data here, we don't
4860 * take any special action to blank the start of an X11 channel,
4861 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4862 * without having session blanking enabled is likely to leak your
4863 * cookie into the log.
4864 */
51470298 4865 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4866 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
f68353be 4867 PKT_STR, proto,
4868 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
86916870 4869 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4870 PKT_END);
32874aea 4871 } else {
51470298 4872 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
f68353be 4873 PKT_STR, proto,
4874 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
32874aea 4875 }
4876 do {
4877 crReturnV;
ff3187f6 4878 } while (!pktin);
4879 if (pktin->type != SSH1_SMSG_SUCCESS
4880 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4881 bombout(("Protocol confusion"));
7ffdbc1a 4882 crStopV;
ff3187f6 4883 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4884 logevent("X11 forwarding refused");
4885 } else {
4886 logevent("X11 forwarding enabled");
51470298 4887 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4888 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4889 }
4890 }
4891
06fadff5 4892 ssh_setup_portfwd(ssh, &ssh->cfg);
4893 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4894
86916870 4895 if (!ssh->cfg.nopty) {
c6ccd5c2 4896 struct Packet *pkt;
a5dd8467 4897 /* Unpick the terminal-speed string. */
4898 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4899 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4900 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4901 /* Send the pty request. */
c6ccd5c2 4902 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4903 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4904 ssh_pkt_adduint32(pkt, ssh->term_height);
4905 ssh_pkt_adduint32(pkt, ssh->term_width);
4906 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4907 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4908 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4909 ssh1_send_ttymode, (void *)pkt);
4910 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4911 ssh_pkt_adduint32(pkt, ssh->ispeed);
4912 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4913 ssh_pkt_adduint32(pkt, ssh->ospeed);
4914 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4915 s_wrpkt(ssh, pkt);
51470298 4916 ssh->state = SSH_STATE_INTERMED;
32874aea 4917 do {
4918 crReturnV;
ff3187f6 4919 } while (!pktin);
4920 if (pktin->type != SSH1_SMSG_SUCCESS
4921 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4922 bombout(("Protocol confusion"));
7ffdbc1a 4923 crStopV;
ff3187f6 4924 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4925 c_write_str(ssh, "Server refused to allocate pty\r\n");
4926 ssh->editing = ssh->echoing = 1;
32874aea 4927 }
a5dd8467 4928 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4929 ssh->ospeed, ssh->ispeed);
0965bee0 4930 } else {
51470298 4931 ssh->editing = ssh->echoing = 1;
374330e2 4932 }
4933
86916870 4934 if (ssh->cfg.compression) {
51470298 4935 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4936 do {
4937 crReturnV;
ff3187f6 4938 } while (!pktin);
4939 if (pktin->type != SSH1_SMSG_SUCCESS
4940 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4941 bombout(("Protocol confusion"));
7ffdbc1a 4942 crStopV;
ff3187f6 4943 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4944 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4945 }
4ba9b64b 4946 logevent("Started compression");
51470298 4947 ssh->v1_compressing = TRUE;
5366aed8 4948 ssh->cs_comp_ctx = zlib_compress_init();
4949 logevent("Initialised zlib (RFC1950) compression");
4950 ssh->sc_comp_ctx = zlib_decompress_init();
4951 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4952 }
4953
fd5e5847 4954 /*
4955 * Start the shell or command.
4956 *
2e85c969 4957 * Special case: if the first-choice command is an SSH-2
fd5e5847 4958 * subsystem (hence not usable here) and the second choice
4959 * exists, we fall straight back to that.
4960 */
4961 {
86916870 4962 char *cmd = ssh->cfg.remote_cmd_ptr;
04c52f10 4963
4964 if (!cmd) cmd = ssh->cfg.remote_cmd;
fd5e5847 4965
86916870 4966 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4967 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4968 ssh->fallback_cmd = TRUE;
fd5e5847 4969 }
4970 if (*cmd)
51470298 4971 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4972 else
51470298 4973 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4974 logevent("Started session");
4975 }
374330e2 4976
51470298 4977 ssh->state = SSH_STATE_SESSION;
4978 if (ssh->size_needed)
4979 ssh_size(ssh, ssh->term_width, ssh->term_height);
4980 if (ssh->eof_needed)
4981 ssh_special(ssh, TS_EOF);
374330e2 4982
b9d7bcad 4983 if (ssh->ldisc)
4984 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4985 ssh->send_ok = 1;
4986 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4987 while (1) {
d74d141c 4988
51df0ab5 4989 /*
4990 * By this point, most incoming packets are already being
4991 * handled by the dispatch table, and we need only pay
4992 * attention to the unusual ones.
4993 */
0357890f 4994
51df0ab5 4995 crReturnV;
4996 if (pktin) {
4997 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4998 /* may be from EXEC_SHELL on some servers */
ff3187f6 4999 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 5000 /* may be from EXEC_SHELL on some servers
374330e2 5001 * if no pty is available or in other odd cases. Ignore */
374330e2 5002 } else {
ff3187f6 5003 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 5004 crStopV;
374330e2 5005 }
5006 } else {
8df7a775 5007 while (inlen > 0) {
5008 int len = min(inlen, 512);
a2724fba 5009 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5010 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
9a10ecf4 5011 PKTT_OTHER, PKT_END);
8df7a775 5012 in += len;
5013 inlen -= len;
5014 }
374330e2 5015 }
5016 }
5017
5018 crFinishV;
5019}
5020
5021/*
2e85c969 5022 * Handle the top-level SSH-2 protocol.
b09eaa88 5023 */
5024static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5025{
fb983202 5026 char *msg;
b09eaa88 5027 int msglen;
5028
5029 ssh_pkt_getstring(pktin, &msg, &msglen);
fb983202 5030 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 5031}
5032
5033static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5034{
5035 /* log reason code in disconnect message */
5036 char *msg;
5037 int msglen;
5038
5039 ssh_pkt_getstring(pktin, &msg, &msglen);
5040 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5041}
5042
409bfa77 5043static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
b09eaa88 5044{
5045 /* Do nothing, because we're ignoring it! Duhh. */
5046}
5047
5048static void ssh1_protocol_setup(Ssh ssh)
5049{
5050 int i;
5051
5052 /*
5053 * Most messages are handled by the coroutines.
5054 */
5055 for (i = 0; i < 256; i++)
5056 ssh->packet_dispatch[i] = NULL;
5057
5058 /*
5059 * These special message types we install handlers for.
5060 */
5061 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5062 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5063 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5064}
5065
1c1a7262 5066static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
b09eaa88 5067 struct Packet *pktin)
5068{
1c1a7262 5069 unsigned char *in=(unsigned char*)vin;
b09eaa88 5070 if (ssh->state == SSH_STATE_CLOSED)
5071 return;
5072
5073 if (pktin && ssh->packet_dispatch[pktin->type]) {
5074 ssh->packet_dispatch[pktin->type](ssh, pktin);
5075 return;
5076 }
5077
5078 if (!ssh->protocol_initial_phase_done) {
5079 if (do_ssh1_login(ssh, in, inlen, pktin))
5080 ssh->protocol_initial_phase_done = TRUE;
5081 else
5082 return;
5083 }
5084
5085 do_ssh1_connection(ssh, in, inlen, pktin);
5086}
5087
5088/*
e5574168 5089 * Utility routine for decoding comma-separated strings in KEXINIT.
5090 */
32874aea 5091static int in_commasep_string(char *needle, char *haystack, int haylen)
5092{
57356d63 5093 int needlen;
5094 if (!needle || !haystack) /* protect against null pointers */
5095 return 0;
5096 needlen = strlen(needle);
e5574168 5097 while (1) {
32874aea 5098 /*
5099 * Is it at the start of the string?
5100 */
5101 if (haylen >= needlen && /* haystack is long enough */
5102 !memcmp(needle, haystack, needlen) && /* initial match */
5103 (haylen == needlen || haystack[needlen] == ',')
5104 /* either , or EOS follows */
5105 )
5106 return 1;
5107 /*
5108 * If not, search for the next comma and resume after that.
5109 * If no comma found, terminate.
5110 */
5111 while (haylen > 0 && *haystack != ',')
5112 haylen--, haystack++;
5113 if (haylen == 0)
5114 return 0;
5115 haylen--, haystack++; /* skip over comma itself */
e5574168 5116 }
5117}
5118
5119/*
b59743d5 5120 * Similar routine for checking whether we have the first string in a list.
5121 */
5122static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5123{
5124 int needlen;
5125 if (!needle || !haystack) /* protect against null pointers */
5126 return 0;
5127 needlen = strlen(needle);
5128 /*
5129 * Is it at the start of the string?
5130 */
5131 if (haylen >= needlen && /* haystack is long enough */
5132 !memcmp(needle, haystack, needlen) && /* initial match */
5133 (haylen == needlen || haystack[needlen] == ',')
5134 /* either , or EOS follows */
5135 )
5136 return 1;
5137 return 0;
5138}
5139
5140
5141/*
2e85c969 5142 * SSH-2 key creation method.
754c0df9 5143 * (Currently assumes 2 lots of any hash are sufficient to generate
5144 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
d39f364a 5145 */
754c0df9 5146#define SSH2_MKKEY_ITERS (2)
b672f405 5147static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
d8baa528 5148 unsigned char *keyspace)
32874aea 5149{
b672f405 5150 const struct ssh_hash *h = ssh->kex->hash;
5151 void *s;
5152 /* First hlen bytes. */
5153 s = h->init();
51470298 5154 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5155 hash_mpint(h, s, K);
5156 h->bytes(s, H, h->hlen);
5157 h->bytes(s, &chr, 1);
5158 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5159 h->final(s, keyspace);
5160 /* Next hlen bytes. */
5161 s = h->init();
51470298 5162 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 5163 hash_mpint(h, s, K);
5164 h->bytes(s, H, h->hlen);
5165 h->bytes(s, keyspace, h->hlen);
5166 h->final(s, keyspace + h->hlen);
d39f364a 5167}
5168
5169/*
2e85c969 5170 * Handle the SSH-2 transport layer.
e5574168 5171 */
1c1a7262 5172static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
ff3187f6 5173 struct Packet *pktin)
e5574168 5174{
1c1a7262 5175 unsigned char *in = (unsigned char *)vin;
51470298 5176 struct do_ssh2_transport_state {
4763c1c2 5177 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
51470298 5178 Bignum p, g, e, f, K;
3dc9a6a7 5179 void *our_kexinit;
5180 int our_kexinitlen;
51470298 5181 int kex_init_value, kex_reply_value;
5182 const struct ssh_mac **maclist;
5183 int nmacs;
5184 const struct ssh2_cipher *cscipher_tobe;
5185 const struct ssh2_cipher *sccipher_tobe;
5186 const struct ssh_mac *csmac_tobe;
5187 const struct ssh_mac *scmac_tobe;
5188 const struct ssh_compress *cscomp_tobe;
5189 const struct ssh_compress *sccomp_tobe;
fae1a71b 5190 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5191 int hostkeylen, siglen, rsakeylen;
51470298 5192 void *hkey; /* actual host key */
fae1a71b 5193 void *rsakey; /* for RSA kex */
754c0df9 5194 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
83e7d008 5195 int n_preferred_kex;
34557659 5196 const struct ssh_kexes *preferred_kex[KEX_MAX];
51470298 5197 int n_preferred_ciphers;
5198 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5199 const struct ssh_compress *preferred_comp;
e13bba36 5200 int got_session_id, activated_authconn;
ff3187f6 5201 struct Packet *pktout;
3d9449a1 5202 int dlgret;
5203 int guessok;
4763c1c2 5204 int ignorepkt;
51470298 5205 };
5206 crState(do_ssh2_transport_state);
5207
5208 crBegin(ssh->do_ssh2_transport_crstate);
5209
5210 s->cscipher_tobe = s->sccipher_tobe = NULL;
5211 s->csmac_tobe = s->scmac_tobe = NULL;
5212 s->cscomp_tobe = s->sccomp_tobe = NULL;
5213
e13bba36 5214 s->got_session_id = s->activated_authconn = FALSE;
e5574168 5215
e13bba36 5216 /*
5217 * Be prepared to work around the buggy MAC problem.
5218 */
5219 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5220 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5221 else
5222 s->maclist = macs, s->nmacs = lenof(macs);
5223
5224 begin_key_exchange:
acab36bc 5225 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
51470298 5226 {
e13bba36 5227 int i, j, commalist_started;
5228
51470298 5229 /*
83e7d008 5230 * Set up the preferred key exchange. (NULL => warn below here)
5231 */
5232 s->n_preferred_kex = 0;
5233 for (i = 0; i < KEX_MAX; i++) {
5234 switch (ssh->cfg.ssh_kexlist[i]) {
5235 case KEX_DHGEX:
5236 s->preferred_kex[s->n_preferred_kex++] =
5237 &ssh_diffiehellman_gex;
5238 break;
5239 case KEX_DHGROUP14:
5240 s->preferred_kex[s->n_preferred_kex++] =
5241 &ssh_diffiehellman_group14;
5242 break;
5243 case KEX_DHGROUP1:
5244 s->preferred_kex[s->n_preferred_kex++] =
5245 &ssh_diffiehellman_group1;
5246 break;
fae1a71b 5247 case KEX_RSA:
5248 s->preferred_kex[s->n_preferred_kex++] =
5249 &ssh_rsa_kex;
5250 break;
754c0df9 5251 case KEX_WARN:
83e7d008 5252 /* Flag for later. Don't bother if it's the last in
5253 * the list. */
5254 if (i < KEX_MAX - 1) {
5255 s->preferred_kex[s->n_preferred_kex++] = NULL;
5256 }
5257 break;
5258 }
5259 }
83e7d008 5260
83e7d008 5261 /*
51470298 5262 * Set up the preferred ciphers. (NULL => warn below here)
5263 */
5264 s->n_preferred_ciphers = 0;
5265 for (i = 0; i < CIPHER_MAX; i++) {
86916870 5266 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 5267 case CIPHER_BLOWFISH:
5268 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5269 break;
5270 case CIPHER_DES:
86916870 5271 if (ssh->cfg.ssh2_des_cbc) {
51470298 5272 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5273 }
5274 break;
5275 case CIPHER_3DES:
5276 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5277 break;
5278 case CIPHER_AES:
5279 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5280 break;
a2add208 5281 case CIPHER_ARCFOUR:
5282 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5283 break;
51470298 5284 case CIPHER_WARN:
5285 /* Flag for later. Don't bother if it's the last in
5286 * the list. */
5287 if (i < CIPHER_MAX - 1) {
5288 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5289 }
5290 break;
ca20bfcf 5291 }
ca20bfcf 5292 }
7591b9ff 5293
e13bba36 5294 /*
5295 * Set up preferred compression.
5296 */
5297 if (ssh->cfg.compression)
5298 s->preferred_comp = &ssh_zlib;
5299 else
5300 s->preferred_comp = &ssh_comp_none;
51470298 5301
5302 /*
590f6a5f 5303 * Enable queueing of outgoing auth- or connection-layer
5304 * packets while we are in the middle of a key exchange.
5305 */
5306 ssh->queueing = TRUE;
5307
5308 /*
9442dd57 5309 * Flag that KEX is in progress.
5310 */
5311 ssh->kex_in_progress = TRUE;
5312
5313 /*
51470298 5314 * Construct and send our key exchange packet.
5315 */
ff3187f6 5316 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 5317 for (i = 0; i < 16; i++)
ff3187f6 5318 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 5319 /* List key exchange algorithms. */
ff3187f6 5320 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5321 commalist_started = 0;
5322 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5323 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5324 if (!k) continue; /* warning flag */
34557659 5325 for (j = 0; j < k->nkexes; j++) {
5326 if (commalist_started)
5327 ssh2_pkt_addstring_str(s->pktout, ",");
5328 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5329 commalist_started = 1;
5330 }
32874aea 5331 }
51470298 5332 /* List server host key algorithms. */
ff3187f6 5333 ssh2_pkt_addstring_start(s->pktout);
51470298 5334 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 5335 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 5336 if (i < lenof(hostkey_algs) - 1)
ff3187f6 5337 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 5338 }
51470298 5339 /* List client->server encryption algorithms. */
ff3187f6 5340 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5341 commalist_started = 0;
51470298 5342 for (i = 0; i < s->n_preferred_ciphers; i++) {
5343 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5344 if (!c) continue; /* warning flag */
5345 for (j = 0; j < c->nciphers; j++) {
83e7d008 5346 if (commalist_started)
ff3187f6 5347 ssh2_pkt_addstring_str(s->pktout, ",");
5348 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5349 commalist_started = 1;
51470298 5350 }
5351 }
5352 /* List server->client encryption algorithms. */
ff3187f6 5353 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5354 commalist_started = 0;
51470298 5355 for (i = 0; i < s->n_preferred_ciphers; i++) {
5356 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5357 if (!c) continue; /* warning flag */
5358 for (j = 0; j < c->nciphers; j++) {
83e7d008 5359 if (commalist_started)
ff3187f6 5360 ssh2_pkt_addstring_str(s->pktout, ",");
5361 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5362 commalist_started = 1;
51470298 5363 }
5364 }
5365 /* List client->server MAC algorithms. */
ff3187f6 5366 ssh2_pkt_addstring_start(s->pktout);
51470298 5367 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5368 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5369 if (i < s->nmacs - 1)
ff3187f6 5370 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5371 }
5372 /* List server->client MAC algorithms. */
ff3187f6 5373 ssh2_pkt_addstring_start(s->pktout);
51470298 5374 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5375 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5376 if (i < s->nmacs - 1)
ff3187f6 5377 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5378 }
5379 /* List client->server compression algorithms. */
ff3187f6 5380 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5381 assert(lenof(compressions) > 1);
ff3187f6 5382 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5383 for (i = 0; i < lenof(compressions); i++) {
5384 const struct ssh_compress *c = compressions[i];
5385 if (c != s->preferred_comp) {
ff3187f6 5386 ssh2_pkt_addstring_str(s->pktout, ",");
5387 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5388 }
51470298 5389 }
5390 /* List server->client compression algorithms. */
ff3187f6 5391 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5392 assert(lenof(compressions) > 1);
ff3187f6 5393 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5394 for (i = 0; i < lenof(compressions); i++) {
5395 const struct ssh_compress *c = compressions[i];
5396 if (c != s->preferred_comp) {
ff3187f6 5397 ssh2_pkt_addstring_str(s->pktout, ",");
5398 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5399 }
51470298 5400 }
5401 /* List client->server languages. Empty list. */
ff3187f6 5402 ssh2_pkt_addstring_start(s->pktout);
51470298 5403 /* List server->client languages. Empty list. */
ff3187f6 5404 ssh2_pkt_addstring_start(s->pktout);
51470298 5405 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5406 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5407 /* Reserved. */
ff3187f6 5408 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5409 }
0db56f73 5410
3dc9a6a7 5411 s->our_kexinitlen = s->pktout->length - 5;
5412 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5413 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
0db56f73 5414
590f6a5f 5415 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5416
ff3187f6 5417 if (!pktin)
5418 crWaitUntil(pktin);
e5574168 5419
5420 /*
5421 * Now examine the other side's KEXINIT to see what we're up
5422 * to.
5423 */
51470298 5424 {
4763c1c2 5425 char *str, *preferred;
3d9449a1 5426 int i, j, len;
51470298 5427
ff3187f6 5428 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5429 bombout(("expected key exchange packet from server"));
7ffdbc1a 5430 crStop(0);
32874aea 5431 }
51470298 5432 ssh->kex = NULL;
5433 ssh->hostkey = NULL;
5434 s->cscipher_tobe = NULL;
5435 s->sccipher_tobe = NULL;
5436 s->csmac_tobe = NULL;
5437 s->scmac_tobe = NULL;
5438 s->cscomp_tobe = NULL;
5439 s->sccomp_tobe = NULL;
4763c1c2 5440 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5441
ff3187f6 5442 pktin->savedpos += 16; /* skip garbage cookie */
5443 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4763c1c2 5444
5445 preferred = NULL;
83e7d008 5446 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5447 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5448 if (!k) {
4763c1c2 5449 s->warn_kex = TRUE;
5450 } else {
34557659 5451 for (j = 0; j < k->nkexes; j++) {
5452 if (!preferred) preferred = k->list[j]->name;
5453 if (in_commasep_string(k->list[j]->name, str, len)) {
5454 ssh->kex = k->list[j];
5455 break;
5456 }
5457 }
83e7d008 5458 }
4763c1c2 5459 if (ssh->kex)
51470298 5460 break;
32874aea 5461 }
83e7d008 5462 if (!ssh->kex) {
5463 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5464 str ? str : "(null)"));
5465 crStop(0);
5466 }
b59743d5 5467 /*
5468 * Note that the server's guess is considered wrong if it doesn't match
5469 * the first algorithm in our list, even if it's still the algorithm
5470 * we end up using.
5471 */
4763c1c2 5472 s->guessok = first_in_commasep_string(preferred, str, len);
ff3187f6 5473 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5474 for (i = 0; i < lenof(hostkey_algs); i++) {
5475 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5476 ssh->hostkey = hostkey_algs[i];
5477 break;
5478 }
5479 }
3d9449a1 5480 s->guessok = s->guessok &&
b59743d5 5481 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5482 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5483 for (i = 0; i < s->n_preferred_ciphers; i++) {
5484 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5485 if (!c) {
4763c1c2 5486 s->warn_cscipher = TRUE;
51470298 5487 } else {
5488 for (j = 0; j < c->nciphers; j++) {
5489 if (in_commasep_string(c->list[j]->name, str, len)) {
5490 s->cscipher_tobe = c->list[j];
5491 break;
5492 }
ca20bfcf 5493 }
32874aea 5494 }
4763c1c2 5495 if (s->cscipher_tobe)
51470298 5496 break;
32874aea 5497 }
51470298 5498 if (!s->cscipher_tobe) {
6b5cf8b4 5499 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5500 str ? str : "(null)"));
7ffdbc1a 5501 crStop(0);
ca20bfcf 5502 }
0ef8f407 5503
ff3187f6 5504 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5505 for (i = 0; i < s->n_preferred_ciphers; i++) {
5506 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5507 if (!c) {
4763c1c2 5508 s->warn_sccipher = TRUE;
51470298 5509 } else {
5510 for (j = 0; j < c->nciphers; j++) {
5511 if (in_commasep_string(c->list[j]->name, str, len)) {
5512 s->sccipher_tobe = c->list[j];
5513 break;
5514 }
ca20bfcf 5515 }
32874aea 5516 }
4763c1c2 5517 if (s->sccipher_tobe)
51470298 5518 break;
32874aea 5519 }
51470298 5520 if (!s->sccipher_tobe) {
6b5cf8b4 5521 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5522 str ? str : "(null)"));
7ffdbc1a 5523 crStop(0);
ca20bfcf 5524 }
0ef8f407 5525
ff3187f6 5526 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5527 for (i = 0; i < s->nmacs; i++) {
5528 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5529 s->csmac_tobe = s->maclist[i];
5530 break;
5531 }
32874aea 5532 }
ff3187f6 5533 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5534 for (i = 0; i < s->nmacs; i++) {
5535 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5536 s->scmac_tobe = s->maclist[i];
5537 break;
5538 }
32874aea 5539 }
ff3187f6 5540 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5541 for (i = 0; i < lenof(compressions) + 1; i++) {
5542 const struct ssh_compress *c =
5543 i == 0 ? s->preferred_comp : compressions[i - 1];
5544 if (in_commasep_string(c->name, str, len)) {
5545 s->cscomp_tobe = c;
5546 break;
5547 }
32874aea 5548 }
ff3187f6 5549 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5550 for (i = 0; i < lenof(compressions) + 1; i++) {
5551 const struct ssh_compress *c =
5552 i == 0 ? s->preferred_comp : compressions[i - 1];
5553 if (in_commasep_string(c->name, str, len)) {
5554 s->sccomp_tobe = c;
5555 break;
5556 }
32874aea 5557 }
b59743d5 5558 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5559 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
4763c1c2 5560 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5561
5562 if (s->warn_kex) {
5563 ssh_set_frozen(ssh, 1);
5564 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5565 ssh->kex->name,
5566 ssh_dialog_callback, ssh);
5567 if (s->dlgret < 0) {
5568 do {
5569 crReturn(0);
5570 if (pktin) {
5571 bombout(("Unexpected data from server while"
5572 " waiting for user response"));
5573 crStop(0);
5574 }
5575 } while (pktin || inlen > 0);
5576 s->dlgret = ssh->user_response;
5577 }
5578 ssh_set_frozen(ssh, 0);
5579 if (s->dlgret == 0) {
9e296bfa 5580 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5581 0, TRUE);
a5a6f839 5582 crStop(0);
4763c1c2 5583 }
5584 }
5585
5586 if (s->warn_cscipher) {
5587 ssh_set_frozen(ssh, 1);
5588 s->dlgret = askalg(ssh->frontend,
5589 "client-to-server cipher",
5590 s->cscipher_tobe->name,
5591 ssh_dialog_callback, ssh);
5592 if (s->dlgret < 0) {
5593 do {
5594 crReturn(0);
5595 if (pktin) {
5596 bombout(("Unexpected data from server while"
5597 " waiting for user response"));
5598 crStop(0);
5599 }
5600 } while (pktin || inlen > 0);
5601 s->dlgret = ssh->user_response;
5602 }
5603 ssh_set_frozen(ssh, 0);
5604 if (s->dlgret == 0) {
9e296bfa 5605 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5606 0, TRUE);
a5a6f839 5607 crStop(0);
4763c1c2 5608 }
5609 }
5610
5611 if (s->warn_sccipher) {
5612 ssh_set_frozen(ssh, 1);
5613 s->dlgret = askalg(ssh->frontend,
5614 "server-to-client cipher",
5615 s->sccipher_tobe->name,
5616 ssh_dialog_callback, ssh);
5617 if (s->dlgret < 0) {
5618 do {
5619 crReturn(0);
5620 if (pktin) {
5621 bombout(("Unexpected data from server while"
5622 " waiting for user response"));
5623 crStop(0);
5624 }
5625 } while (pktin || inlen > 0);
5626 s->dlgret = ssh->user_response;
5627 }
5628 ssh_set_frozen(ssh, 0);
5629 if (s->dlgret == 0) {
9e296bfa 5630 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5631 0, TRUE);
a5a6f839 5632 crStop(0);
4763c1c2 5633 }
5634 }
5635
b672f405 5636 ssh->exhash = ssh->kex->hash->init();
5637 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5638 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5639 hash_string(ssh->kex->hash, ssh->exhash,
5640 s->our_kexinit, s->our_kexinitlen);
3dc9a6a7 5641 sfree(s->our_kexinit);
5642 if (pktin->length > 5)
b672f405 5643 hash_string(ssh->kex->hash, ssh->exhash,
5644 pktin->data + 5, pktin->length - 5);
3dc9a6a7 5645
4763c1c2 5646 if (s->ignorepkt) /* first_kex_packet_follows */
b59743d5 5647 crWaitUntil(pktin); /* Ignore packet */
e5574168 5648 }
e5574168 5649
fae1a71b 5650 if (ssh->kex->main_type == KEXTYPE_DH) {
30774ba3 5651 /*
5652 * Work out the number of bits of key we will need from the
5653 * key exchange. We start with the maximum key length of
5654 * either cipher...
5655 */
5656 {
5657 int csbits, scbits;
5658
5659 csbits = s->cscipher_tobe->keylen;
5660 scbits = s->sccipher_tobe->keylen;
5661 s->nbits = (csbits > scbits ? csbits : scbits);
5662 }
5663 /* The keys only have hlen-bit entropy, since they're based on
5664 * a hash. So cap the key size at hlen bits. */
5665 if (s->nbits > ssh->kex->hash->hlen * 8)
5666 s->nbits = ssh->kex->hash->hlen * 8;
5667
5668 /*
5669 * If we're doing Diffie-Hellman group exchange, start by
5670 * requesting a group.
5671 */
5672 if (!ssh->kex->pdata) {
5673 logevent("Doing Diffie-Hellman group exchange");
acab36bc 5674 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
30774ba3 5675 /*
5676 * Work out how big a DH group we will need to allow that
5677 * much data.
5678 */
5679 s->pbits = 512 << ((s->nbits - 1) / 64);
5680 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5681 ssh2_pkt_adduint32(s->pktout, s->pbits);
5682 ssh2_pkt_send_noqueue(ssh, s->pktout);
5683
5684 crWaitUntil(pktin);
5685 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5686 bombout(("expected key exchange group packet from server"));
5687 crStop(0);
5688 }
5689 s->p = ssh2_pkt_getmp(pktin);
5690 s->g = ssh2_pkt_getmp(pktin);
5691 if (!s->p || !s->g) {
5692 bombout(("unable to read mp-ints from incoming group packet"));
5693 crStop(0);
5694 }
5695 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5696 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5697 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5698 } else {
acab36bc 5699 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
30774ba3 5700 ssh->kex_ctx = dh_setup_group(ssh->kex);
5701 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5702 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5703 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5704 ssh->kex->groupname);
5705 }
e5574168 5706
30774ba3 5707 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
5708 ssh->kex->hash->text_name);
5709 /*
5710 * Now generate and send e for Diffie-Hellman.
5711 */
5712 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5713 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5714 s->pktout = ssh2_pkt_init(s->kex_init_value);
5715 ssh2_pkt_addmp(s->pktout, s->e);
5716 ssh2_pkt_send_noqueue(ssh, s->pktout);
5717
5718 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5719 crWaitUntil(pktin);
5720 if (pktin->type != s->kex_reply_value) {
5721 bombout(("expected key exchange reply packet from server"));
5722 crStop(0);
5723 }
5724 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5725 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5726 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5727 s->f = ssh2_pkt_getmp(pktin);
5728 if (!s->f) {
5729 bombout(("unable to parse key exchange reply packet"));
5730 crStop(0);
5731 }
5732 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5733
30774ba3 5734 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5735
30774ba3 5736 /* We assume everything from now on will be quick, and it might
5737 * involve user interaction. */
5738 set_busy_status(ssh->frontend, BUSY_NOT);
755e0524 5739
30774ba3 5740 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5741 if (!ssh->kex->pdata) {
5742 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5743 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5744 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5745 }
5746 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5747 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5748
5749 dh_cleanup(ssh->kex_ctx);
5750 freebn(s->f);
5751 if (!ssh->kex->pdata) {
5752 freebn(s->g);
5753 freebn(s->p);
5754 }
fae1a71b 5755 } else {
5756 logeventf(ssh, "Doing RSA key exchange with hash %s",
5757 ssh->kex->hash->text_name);
acab36bc 5758 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
fae1a71b 5759 /*
5760 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
5761 * from the server.
5762 */
5763 crWaitUntil(pktin);
5764 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
5765 bombout(("expected RSA public key packet from server"));
5766 crStop(0);
5767 }
5768
5769 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5770 hash_string(ssh->kex->hash, ssh->exhash,
5771 s->hostkeydata, s->hostkeylen);
5772 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5773
5774 {
5775 char *keydata;
5776 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
5777 s->rsakeydata = snewn(s->rsakeylen, char);
5778 memcpy(s->rsakeydata, keydata, s->rsakeylen);
5779 }
5780
5781 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
5782 if (!s->rsakey) {
5783 sfree(s->rsakeydata);
5784 bombout(("unable to parse RSA public key from server"));
5785 crStop(0);
5786 }
5787
5788 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
5789
5790 /*
5791 * Next, set up a shared secret K, of precisely KLEN -
5792 * 2*HLEN - 49 bits, where KLEN is the bit length of the
5793 * RSA key modulus and HLEN is the bit length of the hash
5794 * we're using.
5795 */
5796 {
5797 int klen = ssh_rsakex_klen(s->rsakey);
5798 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
5799 int i, byte = 0;
5800 unsigned char *kstr1, *kstr2, *outstr;
5801 int kstr1len, kstr2len, outstrlen;
5802
5803 s->K = bn_power_2(nbits - 1);
5804
5805 for (i = 0; i < nbits; i++) {
5806 if ((i & 7) == 0) {
5807 byte = random_byte();
5808 }
5809 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
5810 }
5811
5812 /*
5813 * Encode this as an mpint.
5814 */
5815 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
5816 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
5817 PUT_32BIT(kstr2, kstr1len);
5818 memcpy(kstr2 + 4, kstr1, kstr1len);
5819
5820 /*
5821 * Encrypt it with the given RSA key.
5822 */
5823 outstrlen = (klen + 7) / 8;
5824 outstr = snewn(outstrlen, unsigned char);
5825 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
5826 outstr, outstrlen, s->rsakey);
5827
5828 /*
5829 * And send it off in a return packet.
5830 */
5831 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
5832 ssh2_pkt_addstring_start(s->pktout);
7108a872 5833 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
fae1a71b 5834 ssh2_pkt_send_noqueue(ssh, s->pktout);
5835
5836 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
5837
5838 sfree(kstr2);
5839 sfree(kstr1);
5840 sfree(outstr);
5841 }
5842
5843 ssh_rsakex_freekey(s->rsakey);
5844
5845 crWaitUntil(pktin);
5846 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
5847 sfree(s->rsakeydata);
5848 bombout(("expected signature packet from server"));
5849 crStop(0);
5850 }
5851
5852 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5853
5854 sfree(s->rsakeydata);
5855 }
5856
b672f405 5857 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
5858 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
5859 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
e5574168 5860
fabd1805 5861 ssh->kex_ctx = NULL;
3709bfe9 5862
7cca0d81 5863#if 0
765c4200 5864 debug(("Exchange hash is:\n"));
b672f405 5865 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7cca0d81 5866#endif
5867
51470298 5868 if (!s->hkey ||
5869 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
b672f405 5870 (char *)s->exchange_hash,
5871 ssh->kex->hash->hlen)) {
6b5cf8b4 5872 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5873 crStop(0);
8d5de777 5874 }
e5574168 5875
5876 /*
7cca0d81 5877 * Authenticate remote host: verify host key. (We've already
5878 * checked the signature of the exchange hash.)
e5574168 5879 */
51470298 5880 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5881 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 5882 ssh_set_frozen(ssh, 1);
5883 s->dlgret = verify_ssh_host_key(ssh->frontend,
5884 ssh->savedhost, ssh->savedport,
5885 ssh->hostkey->keytype, s->keystr,
5886 s->fingerprint,
5887 ssh_dialog_callback, ssh);
5888 if (s->dlgret < 0) {
5889 do {
5890 crReturn(0);
5891 if (pktin) {
5892 bombout(("Unexpected data from server while waiting"
5893 " for user host key response"));
5894 crStop(0);
5895 }
5896 } while (pktin || inlen > 0);
5897 s->dlgret = ssh->user_response;
5898 }
5899 ssh_set_frozen(ssh, 0);
5900 if (s->dlgret == 0) {
9e296bfa 5901 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5902 0, TRUE);
3d9449a1 5903 crStop(0);
5904 }
e13bba36 5905 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5906 logevent("Host key fingerprint is:");
51470298 5907 logevent(s->fingerprint);
5e0d7cb8 5908 }
51470298 5909 sfree(s->fingerprint);
5910 sfree(s->keystr);
5911 ssh->hostkey->freekey(s->hkey);
d39f364a 5912
5913 /*
9442dd57 5914 * The exchange hash from the very first key exchange is also
5915 * the session id, used in session key construction and
5916 * authentication.
5917 */
e13bba36 5918 if (!s->got_session_id) {
b672f405 5919 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
9442dd57 5920 memcpy(ssh->v2_session_id, s->exchange_hash,
5921 sizeof(s->exchange_hash));
b672f405 5922 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6052bb76 5923 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
e13bba36 5924 s->got_session_id = TRUE;
5925 }
9442dd57 5926
5927 /*
7cca0d81 5928 * Send SSH2_MSG_NEWKEYS.
d39f364a 5929 */
ff3187f6 5930 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5931 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5932 ssh->outgoing_data_size = 0; /* start counting from here */
5933
5934 /*
5935 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5936 * client-to-server session keys.
9442dd57 5937 */
5938 if (ssh->cs_cipher_ctx)
5939 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5940 ssh->cscipher = s->cscipher_tobe;
5941 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5942
5943 if (ssh->cs_mac_ctx)
5944 ssh->csmac->free_context(ssh->cs_mac_ctx);
5945 ssh->csmac = s->csmac_tobe;
5946 ssh->cs_mac_ctx = ssh->csmac->make_context();
5947
5948 if (ssh->cs_comp_ctx)
5949 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5950 ssh->cscomp = s->cscomp_tobe;
5951 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5952
5953 /*
5954 * Set IVs on client-to-server keys. Here we use the exchange
5955 * hash from the _first_ key exchange.
5956 */
5957 {
754c0df9 5958 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
5959 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 5960 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
754c0df9 5961 assert((ssh->cscipher->keylen+7) / 8 <=
5962 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 5963 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
b672f405 5964 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
754c0df9 5965 assert(ssh->cscipher->blksize <=
5966 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 5967 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
b672f405 5968 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
754c0df9 5969 assert(ssh->csmac->len <=
5970 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
9442dd57 5971 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
754c0df9 5972 memset(keyspace, 0, sizeof(keyspace));
9442dd57 5973 }
5974
5975 logeventf(ssh, "Initialised %.200s client->server encryption",
5976 ssh->cscipher->text_name);
5977 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5978 ssh->csmac->text_name);
5979 if (ssh->cscomp->text_name)
5980 logeventf(ssh, "Initialised %s compression",
5981 ssh->cscomp->text_name);
590f6a5f 5982
5983 /*
5984 * Now our end of the key exchange is complete, we can send all
5985 * our queued higher-layer packets.
5986 */
5987 ssh->queueing = FALSE;
5988 ssh2_pkt_queuesend(ssh);
d39f364a 5989
5990 /*
8406eaf9 5991 * Expect SSH2_MSG_NEWKEYS from server.
5992 */
ff3187f6 5993 crWaitUntil(pktin);
5994 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5995 bombout(("expected new-keys packet from server"));
7ffdbc1a 5996 crStop(0);
8406eaf9 5997 }
9442dd57 5998 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5999
6000 /*
9442dd57 6001 * We've seen server NEWKEYS, so create and initialise
6002 * server-to-client session keys.
d39f364a 6003 */
371e569c 6004 if (ssh->sc_cipher_ctx)
6005 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 6006 ssh->sccipher = s->sccipher_tobe;
371e569c 6007 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 6008
e0e1a00d 6009 if (ssh->sc_mac_ctx)
6010 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 6011 ssh->scmac = s->scmac_tobe;
e0e1a00d 6012 ssh->sc_mac_ctx = ssh->scmac->make_context();
6013
5366aed8 6014 if (ssh->sc_comp_ctx)
6015 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 6016 ssh->sccomp = s->sccomp_tobe;
5366aed8 6017 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6018
d39f364a 6019 /*
9442dd57 6020 * Set IVs on server-to-client keys. Here we use the exchange
6021 * hash from the _first_ key exchange.
d39f364a 6022 */
51470298 6023 {
754c0df9 6024 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6025 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
b672f405 6026 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
754c0df9 6027 assert((ssh->sccipher->keylen+7) / 8 <=
6028 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6029 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
b672f405 6030 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
754c0df9 6031 assert(ssh->sccipher->blksize <=
6032 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
371e569c 6033 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
b672f405 6034 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
754c0df9 6035 assert(ssh->scmac->len <=
6036 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
e0e1a00d 6037 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
754c0df9 6038 memset(keyspace, 0, sizeof(keyspace));
51470298 6039 }
57356d63 6040 logeventf(ssh, "Initialised %.200s server->client encryption",
6041 ssh->sccipher->text_name);
6c135243 6042 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6043 ssh->scmac->text_name);
57356d63 6044 if (ssh->sccomp->text_name)
6045 logeventf(ssh, "Initialised %s decompression",
6046 ssh->sccomp->text_name);
9442dd57 6047
6048 /*
fae1a71b 6049 * Free shared secret.
9442dd57 6050 */
679539d7 6051 freebn(s->K);
d39f364a 6052
033b4cef 6053 /*
e13bba36 6054 * Key exchange is over. Loop straight back round if we have a
6055 * deferred rekey reason.
6056 */
6057 if (ssh->deferred_rekey_reason) {
6058 logevent(ssh->deferred_rekey_reason);
6059 pktin = NULL;
6060 ssh->deferred_rekey_reason = NULL;
6061 goto begin_key_exchange;
6062 }
6063
6064 /*
6065 * Otherwise, schedule a timer for our next rekey.
9442dd57 6066 */
6067 ssh->kex_in_progress = FALSE;
e6c1536e 6068 ssh->last_rekey = GETTICKCOUNT();
d57f70af 6069 if (ssh->cfg.ssh_rekey_time != 0)
6070 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6071 ssh2_timer, ssh);
e13bba36 6072
9442dd57 6073 /*
0db56f73 6074 * If this is the first key exchange phase, we must pass the
6075 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6076 * wants to see it but because it will need time to initialise
6077 * itself before it sees an actual packet. In subsequent key
6078 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6079 * it would only confuse the layer above.
6080 */
e13bba36 6081 if (s->activated_authconn) {
0e3607ed 6082 crReturn(0);
0db56f73 6083 }
e13bba36 6084 s->activated_authconn = TRUE;
0db56f73 6085
6086 /*
7cca0d81 6087 * Now we're encrypting. Begin returning 1 to the protocol main
6088 * function so that other things can run on top of the
6089 * transport. If we ever see a KEXINIT, we must go back to the
6090 * start.
9442dd57 6091 *
6092 * We _also_ go back to the start if we see pktin==NULL and
6093 * inlen==-1, because this is a special signal meaning
6094 * `initiate client-driven rekey', and `in' contains a message
6095 * giving the reason for the rekey.
033b4cef 6096 */
9442dd57 6097 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6098 (!pktin && inlen == -1))) {
f382c87d 6099 wait_for_rekey:
32874aea 6100 crReturn(1);
e96adf72 6101 }
9442dd57 6102 if (pktin) {
6103 logevent("Server initiated key re-exchange");
6104 } else {
f382c87d 6105 /*
6106 * Special case: if the server bug is set that doesn't
6107 * allow rekeying, we give a different log message and
6108 * continue waiting. (If such a server _initiates_ a rekey,
6109 * we process it anyway!)
6110 */
6111 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6112 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6113 (char *)in);
6114 /* Reset the counters, so that at least this message doesn't
6115 * hit the event log _too_ often. */
6116 ssh->outgoing_data_size = 0;
6117 ssh->incoming_data_size = 0;
6118 if (ssh->cfg.ssh_rekey_time != 0) {
6119 ssh->next_rekey =
6120 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6121 ssh2_timer, ssh);
6122 }
6123 goto wait_for_rekey; /* this is utterly horrid */
6124 } else {
6125 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 6126 }
9442dd57 6127 }
7cca0d81 6128 goto begin_key_exchange;
e5574168 6129
6130 crFinish(1);
6131}
6132
7cca0d81 6133/*
2e85c969 6134 * Add data to an SSH-2 channel output buffer.
783415f8 6135 */
32874aea 6136static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6137 int len)
6138{
5471d09a 6139 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 6140}
6141
6142/*
2e85c969 6143 * Attempt to send data on an SSH-2 channel.
783415f8 6144 */
5471d09a 6145static int ssh2_try_send(struct ssh_channel *c)
32874aea 6146{
51470298 6147 Ssh ssh = c->ssh;
ff3187f6 6148 struct Packet *pktout;
51470298 6149
5471d09a 6150 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6151 int len;
6152 void *data;
6153 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6154 if ((unsigned)len > c->v.v2.remwindow)
6155 len = c->v.v2.remwindow;
6156 if ((unsigned)len > c->v.v2.remmaxpkt)
6157 len = c->v.v2.remmaxpkt;
ff3187f6 6158 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6159 ssh2_pkt_adduint32(pktout, c->remoteid);
ff3187f6 6160 ssh2_pkt_addstring_start(pktout);
a2724fba 6161 dont_log_data(ssh, pktout, PKTLOG_OMIT);
ff3187f6 6162 ssh2_pkt_addstring_data(pktout, data, len);
6163 end_log_omission(ssh, pktout);
6164 ssh2_pkt_send(ssh, pktout);
5471d09a 6165 bufchain_consume(&c->v.v2.outbuffer, len);
6166 c->v.v2.remwindow -= len;
6167 }
6168
6169 /*
6170 * After having sent as much data as we can, return the amount
6171 * still buffered.
6172 */
6173 return bufchain_size(&c->v.v2.outbuffer);
6174}
6175
1bfc7e93 6176static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
6177{
6178 int bufsize;
6179 if (c->closes)
6180 return; /* don't send on closing channels */
6181 bufsize = ssh2_try_send(c);
6182 if (bufsize == 0) {
6183 switch (c->type) {
6184 case CHAN_MAINSESSION:
6185 /* stdin need not receive an unthrottle
6186 * notification since it will be polled */
6187 break;
6188 case CHAN_X11:
6189 x11_unthrottle(c->u.x11.s);
6190 break;
6191 case CHAN_AGENT:
6192 /* agent sockets are request/response and need no
6193 * buffer management */
6194 break;
6195 case CHAN_SOCKDATA:
6196 pfd_unthrottle(c->u.pfd.s);
6197 break;
6198 }
6199 }
6200}
6201
5471d09a 6202/*
2e85c969 6203 * Potentially enlarge the window on an SSH-2 channel.
5471d09a 6204 */
9fca3f8c 6205static void ssh2_set_window(struct ssh_channel *c, int newwin)
5471d09a 6206{
51470298 6207 Ssh ssh = c->ssh;
6208
6b69f42e 6209 /*
6210 * Never send WINDOW_ADJUST for a channel that the remote side
6211 * already thinks it's closed; there's no point, since it won't
6212 * be sending any more data anyway.
6213 */
6214 if (c->closes != 0)
6215 return;
6216
d252310a 6217 /*
6218 * Only send a WINDOW_ADJUST if there's significantly more window
6219 * available than the other end thinks there is. This saves us
6220 * sending a WINDOW_ADJUST for every character in a shell session.
6221 *
6222 * "Significant" is arbitrarily defined as half the window size.
6223 */
3361b80a 6224 if (newwin / 2 >= c->v.v2.locwindow) {
ff3187f6 6225 struct Packet *pktout;
0e443c99 6226 struct winadj *wa;
ff3187f6 6227
0e443c99 6228 /*
6229 * In order to keep track of how much window the client
6230 * actually has available, we'd like it to acknowledge each
6231 * WINDOW_ADJUST. We can't do that directly, so we accompany
6232 * it with a CHANNEL_REQUEST that has to be acknowledged.
6233 *
6234 * This is only necessary if we're opening the window wide.
6235 * If we're not, then throughput is being constrained by
6236 * something other than the maximum window size anyway.
6237 *
6238 * We also only send this if the main channel has finished its
6239 * initial CHANNEL_REQUESTs and installed the default
6240 * CHANNEL_FAILURE handler, so as not to risk giving it
6241 * unexpected CHANNEL_FAILUREs.
6242 */
6243 if (newwin == c->v.v2.locmaxwin &&
6244 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) {
6245 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6246 ssh2_pkt_adduint32(pktout, c->remoteid);
6247 ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");
6248 ssh2_pkt_addbool(pktout, TRUE);
6249 ssh2_pkt_send(ssh, pktout);
6250
6251 /*
6252 * CHANNEL_FAILURE doesn't come with any indication of
6253 * what message caused it, so we have to keep track of the
6254 * outstanding CHANNEL_REQUESTs ourselves.
6255 */
6256 wa = snew(struct winadj);
6257 wa->size = newwin - c->v.v2.locwindow;
6258 wa->next = NULL;
6259 if (!c->v.v2.winadj_head)
6260 c->v.v2.winadj_head = wa;
6261 else
6262 c->v.v2.winadj_tail->next = wa;
6263 c->v.v2.winadj_tail = wa;
6264 if (c->v.v2.throttle_state != UNTHROTTLED)
6265 c->v.v2.throttle_state = UNTHROTTLING;
6266 } else {
6267 /* Pretend the WINDOW_ADJUST was acked immediately. */
6268 c->v.v2.remlocwin = newwin;
6269 c->v.v2.throttle_state = THROTTLED;
6270 }
ff3187f6 6271 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6272 ssh2_pkt_adduint32(pktout, c->remoteid);
6273 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6274 ssh2_pkt_send(ssh, pktout);
5471d09a 6275 c->v.v2.locwindow = newwin;
783415f8 6276 }
6277}
6278
0e443c99 6279static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin)
6280{
6281 /*
6282 * The only time this should get called is for "winadj@putty"
6283 * messages sent above. All other channel requests are either
6284 * sent with want_reply false or are sent before this handler gets
6285 * installed.
6286 */
6287 unsigned i = ssh_pkt_getuint32(pktin);
6288 struct ssh_channel *c;
6289 struct winadj *wa;
6290
6291 c = find234(ssh->channels, &i, ssh_channelfind);
6292 if (!c)
6293 return; /* nonexistent channel */
6294 wa = c->v.v2.winadj_head;
6295 if (!wa)
6296 logevent("excess SSH_MSG_CHANNEL_FAILURE");
6297 else {
6298 c->v.v2.winadj_head = wa->next;
6299 c->v.v2.remlocwin += wa->size;
6300 sfree(wa);
6301 /*
6302 * winadj messages are only sent when the window is fully open,
6303 * so if we get an ack of one, we know any pending unthrottle
6304 * is complete.
6305 */
6306 if (c->v.v2.throttle_state == UNTHROTTLING)
6307 c->v.v2.throttle_state = UNTHROTTLED;
6308 }
6309}
6310
51df0ab5 6311static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 6312{
6313 unsigned i = ssh_pkt_getuint32(pktin);
6314 struct ssh_channel *c;
6315 c = find234(ssh->channels, &i, ssh_channelfind);
1bfc7e93 6316 if (c && !c->closes) {
b09eaa88 6317 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
1bfc7e93 6318 ssh2_try_send_and_unthrottle(c);
6319 }
b09eaa88 6320}
6321
51df0ab5 6322static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6323{
6324 char *data;
6d44acc9 6325 int length;
51df0ab5 6326 unsigned i = ssh_pkt_getuint32(pktin);
6327 struct ssh_channel *c;
6328 c = find234(ssh->channels, &i, ssh_channelfind);
6329 if (!c)
6330 return; /* nonexistent channel */
6331 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6332 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6333 return; /* extended but not stderr */
6334 ssh_pkt_getstring(pktin, &data, &length);
6335 if (data) {
6336 int bufsize = 0;
6337 c->v.v2.locwindow -= length;
0e443c99 6338 c->v.v2.remlocwin -= length;
51df0ab5 6339 switch (c->type) {
6340 case CHAN_MAINSESSION:
6341 bufsize =
6342 from_backend(ssh->frontend, pktin->type ==
6343 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6344 data, length);
6345 break;
6346 case CHAN_X11:
6347 bufsize = x11_send(c->u.x11.s, data, length);
6348 break;
6349 case CHAN_SOCKDATA:
6350 bufsize = pfd_send(c->u.pfd.s, data, length);
6351 break;
6352 case CHAN_AGENT:
6353 while (length > 0) {
6354 if (c->u.a.lensofar < 4) {
62ddb51e 6355 unsigned int l = min(4 - c->u.a.lensofar,
6356 (unsigned)length);
51df0ab5 6357 memcpy(c->u.a.msglen + c->u.a.lensofar,
6358 data, l);
6359 data += l;
6360 length -= l;
6361 c->u.a.lensofar += l;
6362 }
6363 if (c->u.a.lensofar == 4) {
6364 c->u.a.totallen =
6365 4 + GET_32BIT(c->u.a.msglen);
6366 c->u.a.message = snewn(c->u.a.totallen,
6367 unsigned char);
6368 memcpy(c->u.a.message, c->u.a.msglen, 4);
6369 }
6370 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 6371 unsigned int l =
51df0ab5 6372 min(c->u.a.totallen - c->u.a.lensofar,
62ddb51e 6373 (unsigned)length);
51df0ab5 6374 memcpy(c->u.a.message + c->u.a.lensofar,
6375 data, l);
6376 data += l;
6377 length -= l;
6378 c->u.a.lensofar += l;
6379 }
6380 if (c->u.a.lensofar == c->u.a.totallen) {
6381 void *reply;
6382 int replylen;
6383 if (agent_query(c->u.a.message,
6384 c->u.a.totallen,
6385 &reply, &replylen,
6386 ssh_agentf_callback, c))
6387 ssh_agentf_callback(c, reply, replylen);
6388 sfree(c->u.a.message);
6389 c->u.a.lensofar = 0;
6390 }
6391 }
6392 bufsize = 0;
6393 break;
6394 }
6395 /*
0e443c99 6396 * If it looks like the remote end hit the end of its window,
6397 * and we didn't want it to do that, think about using a
6398 * larger window.
6399 */
6400 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6401 c->v.v2.locmaxwin < 0x40000000)
6402 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6403 /*
51df0ab5 6404 * If we are not buffering too much data,
6405 * enlarge the window again at the remote side.
467e064d 6406 * If we are buffering too much, we may still
6407 * need to adjust the window if the server's
6408 * sent excess data.
51df0ab5 6409 */
9b53e9b8 6410 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6411 c->v.v2.locmaxwin - bufsize : 0);
51df0ab5 6412 }
6413}
6414
6415static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6416{
6417 unsigned i = ssh_pkt_getuint32(pktin);
6418 struct ssh_channel *c;
6419
6420 c = find234(ssh->channels, &i, ssh_channelfind);
6421 if (!c)
6422 return; /* nonexistent channel */
6423
6424 if (c->type == CHAN_X11) {
6425 /*
6426 * Remote EOF on an X11 channel means we should
6427 * wrap up and close the channel ourselves.
6428 */
6429 x11_close(c->u.x11.s);
6430 sshfwd_close(c);
6431 } else if (c->type == CHAN_AGENT) {
6432 sshfwd_close(c);
6433 } else if (c->type == CHAN_SOCKDATA) {
6434 pfd_close(c->u.pfd.s);
6435 sshfwd_close(c);
6436 }
6437}
6438
6439static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6440{
6441 unsigned i = ssh_pkt_getuint32(pktin);
6442 struct ssh_channel *c;
6443 struct Packet *pktout;
6444
6445 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 6446 if (!c || c->halfopen) {
51df0ab5 6447 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6448 c ? "half-open" : "nonexistent", i));
6449 return;
6450 }
6451 /* Do pre-close processing on the channel. */
6452 switch (c->type) {
6453 case CHAN_MAINSESSION:
6454 ssh->mainchan = NULL;
6455 update_specials_menu(ssh->frontend);
6456 break;
6457 case CHAN_X11:
6458 if (c->u.x11.s != NULL)
6459 x11_close(c->u.x11.s);
6460 sshfwd_close(c);
6461 break;
6462 case CHAN_AGENT:
6463 sshfwd_close(c);
6464 break;
6465 case CHAN_SOCKDATA:
6466 if (c->u.pfd.s != NULL)
6467 pfd_close(c->u.pfd.s);
6468 sshfwd_close(c);
6469 break;
6470 }
6471 if (c->closes == 0) {
6472 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6473 ssh2_pkt_adduint32(pktout, c->remoteid);
6474 ssh2_pkt_send(ssh, pktout);
6475 }
6476 del234(ssh->channels, c);
6477 bufchain_clear(&c->v.v2.outbuffer);
6478 sfree(c);
6479
6480 /*
6481 * See if that was the last channel left open.
6482 * (This is only our termination condition if we're
6483 * not running in -N mode.)
6484 */
6485 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
51df0ab5 6486 /*
6487 * We used to send SSH_MSG_DISCONNECT here,
6488 * because I'd believed that _every_ conforming
2e85c969 6489 * SSH-2 connection had to end with a disconnect
51df0ab5 6490 * being sent by at least one side; apparently
6491 * I was wrong and it's perfectly OK to
6492 * unceremoniously slam the connection shut
6493 * when you're done, and indeed OpenSSH feels
6494 * this is more polite than sending a
6495 * DISCONNECT. So now we don't.
6496 */
9e296bfa 6497 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
51df0ab5 6498 }
6499}
6500
6501static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6502{
6503 unsigned i = ssh_pkt_getuint32(pktin);
6504 struct ssh_channel *c;
6505 struct Packet *pktout;
6506
6507 c = find234(ssh->channels, &i, ssh_channelfind);
6508 if (!c)
6509 return; /* nonexistent channel */
6510 if (c->type != CHAN_SOCKDATA_DORMANT)
6511 return; /* dunno why they're confirming this */
6512 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 6513 c->halfopen = FALSE;
51df0ab5 6514 c->type = CHAN_SOCKDATA;
6515 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6516 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6517 if (c->u.pfd.s)
6518 pfd_confirm(c->u.pfd.s);
6519 if (c->closes) {
6520 /*
6521 * We have a pending close on this channel,
6522 * which we decided on before the server acked
6523 * the channel open. So now we know the
6524 * remoteid, we can close it again.
6525 */
6526 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6527 ssh2_pkt_adduint32(pktout, c->remoteid);
6528 ssh2_pkt_send(ssh, pktout);
6529 }
6530}
6531
6532static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6533{
6534 static const char *const reasons[] = {
6535 "<unknown reason code>",
6536 "Administratively prohibited",
6537 "Connect failed",
6538 "Unknown channel type",
6539 "Resource shortage",
6540 };
6541 unsigned i = ssh_pkt_getuint32(pktin);
6542 unsigned reason_code;
6543 char *reason_string;
6544 int reason_length;
51df0ab5 6545 struct ssh_channel *c;
6546 c = find234(ssh->channels, &i, ssh_channelfind);
6547 if (!c)
6548 return; /* nonexistent channel */
6549 if (c->type != CHAN_SOCKDATA_DORMANT)
6550 return; /* dunno why they're failing this */
6551
6552 reason_code = ssh_pkt_getuint32(pktin);
6553 if (reason_code >= lenof(reasons))
6554 reason_code = 0; /* ensure reasons[reason_code] in range */
6555 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 6556 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6557 reasons[reason_code], reason_length, reason_string);
51df0ab5 6558
6559 pfd_close(c->u.pfd.s);
6560
6561 del234(ssh->channels, c);
6562 sfree(c);
6563}
6564
6565static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6566{
6567 unsigned localid;
6568 char *type;
6569 int typelen, want_reply;
6570 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6571 struct ssh_channel *c;
6572 struct Packet *pktout;
6573
6574 localid = ssh_pkt_getuint32(pktin);
6575 ssh_pkt_getstring(pktin, &type, &typelen);
6576 want_reply = ssh2_pkt_getbool(pktin);
6577
6578 /*
6579 * First, check that the channel exists. Otherwise,
6580 * we can instantly disconnect with a rude message.
6581 */
6582 c = find234(ssh->channels, &localid, ssh_channelfind);
6583 if (!c) {
9e296bfa 6584 char *buf = dupprintf("Received channel request for nonexistent"
6585 " channel %d", localid);
6586 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6587 sfree(buf);
51df0ab5 6588 return;
6589 }
6590
6591 /*
6592 * Having got the channel number, we now look at
6593 * the request type string to see if it's something
6594 * we recognise.
6595 */
6596 if (c == ssh->mainchan) {
6597 /*
6598 * We recognise "exit-status" and "exit-signal" on
6599 * the primary channel.
6600 */
6601 if (typelen == 11 &&
6602 !memcmp(type, "exit-status", 11)) {
6603
6604 ssh->exitcode = ssh_pkt_getuint32(pktin);
6605 logeventf(ssh, "Server sent command exit status %d",
6606 ssh->exitcode);
6607 reply = SSH2_MSG_CHANNEL_SUCCESS;
6608
6609 } else if (typelen == 11 &&
6610 !memcmp(type, "exit-signal", 11)) {
6611
6612 int is_plausible = TRUE, is_int = FALSE;
6613 char *fmt_sig = "", *fmt_msg = "";
6614 char *msg;
6615 int msglen = 0, core = FALSE;
6616 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6617 * provide an `int' for the signal, despite its
6618 * having been a `string' in the drafts since at
6619 * least 2001. (Fixed in session.c 1.147.) Try to
6620 * infer which we can safely parse it as. */
6621 {
6622 unsigned char *p = pktin->body +
6623 pktin->savedpos;
6624 long len = pktin->length - pktin->savedpos;
6625 unsigned long num = GET_32BIT(p); /* what is it? */
6626 /* If it's 0, it hardly matters; assume string */
6627 if (num == 0) {
6628 is_int = FALSE;
6629 } else {
6630 int maybe_int = FALSE, maybe_str = FALSE;
6631#define CHECK_HYPOTHESIS(offset, result) \
6632 do { \
6633 long q = offset; \
6634 if (q >= 0 && q+4 <= len) { \
6635 q = q + 4 + GET_32BIT(p+q); \
6636 if (q >= 0 && q+4 <= len && \
c849ff23 6637 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
51df0ab5 6638 result = TRUE; \
6639 } \
6640 } while(0)
6641 CHECK_HYPOTHESIS(4+1, maybe_int);
6642 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6643#undef CHECK_HYPOTHESIS
6644 if (maybe_int && !maybe_str)
6645 is_int = TRUE;
6646 else if (!maybe_int && maybe_str)
6647 is_int = FALSE;
6648 else
6649 /* Crikey. Either or neither. Panic. */
6650 is_plausible = FALSE;
6651 }
6652 }
d051d1b4 6653 ssh->exitcode = 128; /* means `unknown signal' */
51df0ab5 6654 if (is_plausible) {
6655 if (is_int) {
6656 /* Old non-standard OpenSSH. */
6657 int signum = ssh_pkt_getuint32(pktin);
6658 fmt_sig = dupprintf(" %d", signum);
d051d1b4 6659 ssh->exitcode = 128 + signum;
51df0ab5 6660 } else {
6661 /* As per the drafts. */
6662 char *sig;
6663 int siglen;
6664 ssh_pkt_getstring(pktin, &sig, &siglen);
6665 /* Signal name isn't supposed to be blank, but
6666 * let's cope gracefully if it is. */
6667 if (siglen) {
6668 fmt_sig = dupprintf(" \"%.*s\"",
6669 siglen, sig);
6670 }
d051d1b4 6671
6672 /*
6673 * Really hideous method of translating the
6674 * signal description back into a locally
6675 * meaningful number.
6676 */
6677
6678 if (0)
6679 ;
b707973a 6680#define TRANSLATE_SIGNAL(s) \
6681 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
6682 ssh->exitcode = 128 + SIG ## s
d051d1b4 6683#ifdef SIGABRT
b707973a 6684 TRANSLATE_SIGNAL(ABRT);
d051d1b4 6685#endif
6686#ifdef SIGALRM
b707973a 6687 TRANSLATE_SIGNAL(ALRM);
d051d1b4 6688#endif
6689#ifdef SIGFPE
b707973a 6690 TRANSLATE_SIGNAL(FPE);
d051d1b4 6691#endif
6692#ifdef SIGHUP
b707973a 6693 TRANSLATE_SIGNAL(HUP);
d051d1b4 6694#endif
6695#ifdef SIGILL
b707973a 6696 TRANSLATE_SIGNAL(ILL);
d051d1b4 6697#endif
6698#ifdef SIGINT
b707973a 6699 TRANSLATE_SIGNAL(INT);
d051d1b4 6700#endif
6701#ifdef SIGKILL
b707973a 6702 TRANSLATE_SIGNAL(KILL);
d051d1b4 6703#endif
6704#ifdef SIGPIPE
b707973a 6705 TRANSLATE_SIGNAL(PIPE);
d051d1b4 6706#endif
6707#ifdef SIGQUIT
b707973a 6708 TRANSLATE_SIGNAL(QUIT);
d051d1b4 6709#endif
6710#ifdef SIGSEGV
b707973a 6711 TRANSLATE_SIGNAL(SEGV);
d051d1b4 6712#endif
6713#ifdef SIGTERM
b707973a 6714 TRANSLATE_SIGNAL(TERM);
d051d1b4 6715#endif
6716#ifdef SIGUSR1
b707973a 6717 TRANSLATE_SIGNAL(USR1);
d051d1b4 6718#endif
6719#ifdef SIGUSR2
b707973a 6720 TRANSLATE_SIGNAL(USR2);
d051d1b4 6721#endif
b707973a 6722#undef TRANSLATE_SIGNAL
d051d1b4 6723 else
6724 ssh->exitcode = 128;
51df0ab5 6725 }
6726 core = ssh2_pkt_getbool(pktin);
6727 ssh_pkt_getstring(pktin, &msg, &msglen);
6728 if (msglen) {
6729 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6730 }
6731 /* ignore lang tag */
6732 } /* else don't attempt to parse */
6733 logeventf(ssh, "Server exited on signal%s%s%s",
6734 fmt_sig, core ? " (core dumped)" : "",
6735 fmt_msg);
6736 if (*fmt_sig) sfree(fmt_sig);
6737 if (*fmt_msg) sfree(fmt_msg);
6738 reply = SSH2_MSG_CHANNEL_SUCCESS;
6739
6740 }
6741 } else {
6742 /*
6743 * This is a channel request we don't know
6744 * about, so we now either ignore the request
6745 * or respond with CHANNEL_FAILURE, depending
6746 * on want_reply.
6747 */
6748 reply = SSH2_MSG_CHANNEL_FAILURE;
6749 }
6750 if (want_reply) {
6751 pktout = ssh2_pkt_init(reply);
6752 ssh2_pkt_adduint32(pktout, c->remoteid);
6753 ssh2_pkt_send(ssh, pktout);
6754 }
6755}
6756
6757static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6758{
6759 char *type;
6760 int typelen, want_reply;
6761 struct Packet *pktout;
6762
6763 ssh_pkt_getstring(pktin, &type, &typelen);
6764 want_reply = ssh2_pkt_getbool(pktin);
6765
6766 /*
6767 * We currently don't support any global requests
6768 * at all, so we either ignore the request or
6769 * respond with REQUEST_FAILURE, depending on
6770 * want_reply.
6771 */
6772 if (want_reply) {
6773 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6774 ssh2_pkt_send(ssh, pktout);
6775 }
6776}
6777
6778static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6779{
6780 char *type;
6781 int typelen;
6782 char *peeraddr;
6783 int peeraddrlen;
6784 int peerport;
6785 char *error = NULL;
6786 struct ssh_channel *c;
6787 unsigned remid, winsize, pktsize;
6788 struct Packet *pktout;
6789
6790 ssh_pkt_getstring(pktin, &type, &typelen);
6791 c = snew(struct ssh_channel);
6792 c->ssh = ssh;
6793
6794 remid = ssh_pkt_getuint32(pktin);
6795 winsize = ssh_pkt_getuint32(pktin);
6796 pktsize = ssh_pkt_getuint32(pktin);
6797
6798 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6799 char *addrstr;
6800
6801 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6802 addrstr = snewn(peeraddrlen+1, char);
6803 memcpy(addrstr, peeraddr, peeraddrlen);
6804 addrstr[peeraddrlen] = '\0';
6805 peerport = ssh_pkt_getuint32(pktin);
6806
6807 logeventf(ssh, "Received X11 connect request from %s:%d",
6808 addrstr, peerport);
6809
6810 if (!ssh->X11_fwd_enabled)
6811 error = "X11 forwarding is not enabled";
6812 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6813 ssh->x11auth, addrstr, peerport,
6814 &ssh->cfg) != NULL) {
6815 error = "Unable to open an X11 connection";
6816 } else {
6817 logevent("Opening X11 forward connection succeeded");
6818 c->type = CHAN_X11;
6819 }
6820
6821 sfree(addrstr);
6822 } else if (typelen == 15 &&
6823 !memcmp(type, "forwarded-tcpip", 15)) {
6824 struct ssh_rportfwd pf, *realpf;
6825 char *dummy;
6826 int dummylen;
6827 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6828 pf.sport = ssh_pkt_getuint32(pktin);
6829 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6830 peerport = ssh_pkt_getuint32(pktin);
6831 realpf = find234(ssh->rportfwds, &pf, NULL);
6832 logeventf(ssh, "Received remote port %d open request "
6833 "from %s:%d", pf.sport, peeraddr, peerport);
6834 if (realpf == NULL) {
6835 error = "Remote port is not recognised";
6836 } else {
6837 const char *e = pfd_newconnect(&c->u.pfd.s,
6838 realpf->dhost,
6839 realpf->dport, c,
05581745 6840 &ssh->cfg,
6841 realpf->pfrec->addressfamily);
51df0ab5 6842 logeventf(ssh, "Attempting to forward remote port to "
6843 "%s:%d", realpf->dhost, realpf->dport);
6844 if (e != NULL) {
6845 logeventf(ssh, "Port open failed: %s", e);
6846 error = "Port open failed";
6847 } else {
6848 logevent("Forwarded port opened successfully");
6849 c->type = CHAN_SOCKDATA;
6850 }
6851 }
6852 } else if (typelen == 22 &&
c49cf994 6853 !memcmp(type, "auth-agent@openssh.com", 22)) {
51df0ab5 6854 if (!ssh->agentfwd_enabled)
6855 error = "Agent forwarding is not enabled";
6856 else {
6857 c->type = CHAN_AGENT; /* identify channel type */
6858 c->u.a.lensofar = 0;
6859 }
6860 } else {
6861 error = "Unsupported channel type requested";
6862 }
6863
6864 c->remoteid = remid;
64d6ff88 6865 c->halfopen = FALSE;
51df0ab5 6866 if (error) {
6867 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6868 ssh2_pkt_adduint32(pktout, c->remoteid);
6869 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6870 ssh2_pkt_addstring(pktout, error);
6871 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6872 ssh2_pkt_send(ssh, pktout);
6873 logeventf(ssh, "Rejected channel open: %s", error);
6874 sfree(c);
6875 } else {
6876 c->localid = alloc_channel_id(ssh);
6877 c->closes = 0;
9b53e9b8 6878 c->v.v2.locwindow = c->v.v2.locmaxwin = OUR_V2_WINSIZE;
51df0ab5 6879 c->v.v2.remwindow = winsize;
6880 c->v.v2.remmaxpkt = pktsize;
0e443c99 6881 c->v.v2.remlocwin = OUR_V2_WINSIZE;
6882 c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL;
6883 c->v.v2.throttle_state = UNTHROTTLED;
51df0ab5 6884 bufchain_init(&c->v.v2.outbuffer);
6885 add234(ssh->channels, c);
6886 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6887 ssh2_pkt_adduint32(pktout, c->remoteid);
6888 ssh2_pkt_adduint32(pktout, c->localid);
6889 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 6890 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 6891 ssh2_pkt_send(ssh, pktout);
6892 }
6893}
6894
6bbce591 6895/*
6896 * Buffer banner messages for later display at some convenient point.
6897 */
6898static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6899{
6900 /* Arbitrary limit to prevent unbounded inflation of buffer */
6901 if (bufchain_size(&ssh->banner) <= 131072) {
6902 char *banner = NULL;
6903 int size = 0;
6904 ssh_pkt_getstring(pktin, &banner, &size);
6905 if (banner)
6906 bufchain_add(&ssh->banner, banner, size);
6907 }
6908}
6909
c6ccd5c2 6910/* Helper function to deal with sending tty modes for "pty-req" */
6911static void ssh2_send_ttymode(void *data, char *mode, char *val)
6912{
6913 struct Packet *pktout = (struct Packet *)data;
6914 int i = 0;
6915 unsigned int arg = 0;
6916 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6917 if (i == lenof(ssh_ttymodes)) return;
6918 switch (ssh_ttymodes[i].type) {
6919 case TTY_OP_CHAR:
6920 arg = ssh_tty_parse_specchar(val);
6921 break;
6922 case TTY_OP_BOOL:
6923 arg = ssh_tty_parse_boolean(val);
6924 break;
6925 }
6926 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6927 ssh2_pkt_adduint32(pktout, arg);
6928}
6929
783415f8 6930/*
2e85c969 6931 * Handle the SSH-2 userauth and connection layers.
7cca0d81 6932 */
ff3187f6 6933static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6934 struct Packet *pktin)
7cca0d81 6935{
51470298 6936 struct do_ssh2_authconn_state {
6937 enum {
51470298 6938 AUTH_TYPE_NONE,
6939 AUTH_TYPE_PUBLICKEY,
6940 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6941 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6942 AUTH_TYPE_PASSWORD,
6943 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6944 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6945 } type;
a1a1fae4 6946 int done_service_req;
51470298 6947 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
94cd7c3a 6948 int tried_pubkey_config, done_agent;
edd0cb8a 6949 int kbd_inter_refused;
51470298 6950 int we_are_in;
edd0cb8a 6951 prompts_t *cur_prompt;
6952 int num_prompts;
51470298 6953 char username[100];
e955d348 6954 char *password;
51470298 6955 int got_username;
51470298 6956 void *publickey_blob;
6957 int publickey_bloblen;
edd0cb8a 6958 int publickey_encrypted;
6959 char *publickey_algorithm;
6960 char *publickey_comment;
94cd7c3a 6961 unsigned char agent_request[5], *agent_response, *agentp;
6962 int agent_responselen;
6963 unsigned char *pkblob_in_agent;
51470298 6964 int keyi, nkeys;
51470298 6965 char *pkblob, *alg, *commentp;
6966 int pklen, alglen, commentlen;
6967 int siglen, retlen, len;
6968 char *q, *agentreq, *ret;
6969 int try_send;
73feed4f 6970 int num_env, env_left, env_ok;
ff3187f6 6971 struct Packet *pktout;
51470298 6972 };
6973 crState(do_ssh2_authconn_state);
6974
6975 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 6976
a1a1fae4 6977 s->done_service_req = FALSE;
6978 s->we_are_in = FALSE;
6979 if (!ssh->cfg.ssh_no_userauth) {
6980 /*
6981 * Request userauth protocol, and await a response to it.
6982 */
6983 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6984 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6985 ssh2_pkt_send(ssh, s->pktout);
6986 crWaitUntilV(pktin);
6987 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6988 s->done_service_req = TRUE;
6989 }
6990 if (!s->done_service_req) {
6991 /*
6992 * Request connection protocol directly, without authentication.
6993 */
6994 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6995 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6996 ssh2_pkt_send(ssh, s->pktout);
6997 crWaitUntilV(pktin);
6998 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6999 s->we_are_in = TRUE; /* no auth required */
7000 } else {
7001 bombout(("Server refused service request"));
7002 crStopV;
7003 }
8d5de777 7004 }
7cca0d81 7005
94cd7c3a 7006 /* Arrange to be able to deal with any BANNERs that come in.
7007 * (We do this now as packets may come in during the next bit.) */
7008 bufchain_init(&ssh->banner);
7009 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7010 ssh2_msg_userauth_banner;
7011
7cca0d81 7012 /*
edd0cb8a 7013 * Misc one-time setup for authentication.
7014 */
7015 s->publickey_blob = NULL;
7016 if (!s->we_are_in) {
7017
7018 /*
7019 * Load the public half of any configured public key file
7020 * for later use.
7021 */
7022 if (!filename_is_null(ssh->cfg.keyfile)) {
7023 int keytype;
7024 logeventf(ssh, "Reading private key file \"%.150s\"",
7025 filename_to_str(&ssh->cfg.keyfile));
7026 keytype = key_type(&ssh->cfg.keyfile);
7027 if (keytype == SSH_KEYTYPE_SSH2) {
7028 const char *error;
7029 s->publickey_blob =
7030 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
7031 &s->publickey_algorithm,
7032 &s->publickey_bloblen,
7033 &s->publickey_comment, &error);
7034 if (s->publickey_blob) {
7035 s->publickey_encrypted =
7036 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
7037 } else {
7038 char *msgbuf;
7039 logeventf(ssh, "Unable to load private key (%s)",
7040 error);
7041 msgbuf = dupprintf("Unable to load private key file "
7042 "\"%.150s\" (%s)\r\n",
7043 filename_to_str(&ssh->cfg.keyfile),
7044 error);
7045 c_write_str(ssh, msgbuf);
7046 sfree(msgbuf);
7047 }
7048 } else {
7049 char *msgbuf;
7050 logeventf(ssh, "Unable to use this key file (%s)",
7051 key_type_to_str(keytype));
7052 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7053 " (%s)\r\n",
7054 filename_to_str(&ssh->cfg.keyfile),
7055 key_type_to_str(keytype));
7056 c_write_str(ssh, msgbuf);
7057 sfree(msgbuf);
7058 s->publickey_blob = NULL;
7059 }
7060 }
7061
94cd7c3a 7062 /*
7063 * Find out about any keys Pageant has (but if there's a
7064 * public key configured, filter out all others).
7065 */
7066 s->nkeys = 0;
7067 s->agent_response = NULL;
7068 s->pkblob_in_agent = NULL;
116f229d 7069 if (ssh->cfg.tryagent && agent_exists()) {
94cd7c3a 7070
7071 void *r;
7072
7073 logevent("Pageant is running. Requesting keys.");
7074
7075 /* Request the keys held by the agent. */
7076 PUT_32BIT(s->agent_request, 1);
7077 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7078 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7079 ssh_agent_callback, ssh)) {
7080 do {
7081 crReturnV;
7082 if (pktin) {
7083 bombout(("Unexpected data from server while"
7084 " waiting for agent response"));
7085 crStopV;
7086 }
7087 } while (pktin || inlen > 0);
7088 r = ssh->agent_response;
7089 s->agent_responselen = ssh->agent_response_len;
7090 }
7091 s->agent_response = (unsigned char *) r;
7092 if (s->agent_response && s->agent_responselen >= 5 &&
7093 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7094 int keyi;
7095 unsigned char *p;
7096 p = s->agent_response + 5;
7097 s->nkeys = GET_32BIT(p);
7098 p += 4;
7099 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
7100 if (s->publickey_blob) {
7101 /* See if configured key is in agent. */
7102 for (keyi = 0; keyi < s->nkeys; keyi++) {
7103 s->pklen = GET_32BIT(p);
7104 if (s->pklen == s->publickey_bloblen &&
7105 !memcmp(p+4, s->publickey_blob,
7106 s->publickey_bloblen)) {
7107 logeventf(ssh, "Pageant key #%d matches "
7108 "configured key file", keyi);
7109 s->keyi = keyi;
7110 s->pkblob_in_agent = p;
7111 break;
7112 }
7113 p += 4 + s->pklen;
7114 p += GET_32BIT(p) + 4; /* comment */
7115 }
7116 if (!s->pkblob_in_agent) {
7117 logevent("Configured key file not in Pageant");
7118 s->nkeys = 0;
7119 }
7120 }
7121 }
7122 }
7123
edd0cb8a 7124 }
7125
7126 /*
1408a877 7127 * We repeat this whole loop, including the username prompt,
7128 * until we manage a successful authentication. If the user
51470298 7129 * types the wrong _password_, they can be sent back to the
7130 * beginning to try another username, if this is configured on.
7131 * (If they specify a username in the config, they are never
7132 * asked, even if they do give a wrong password.)
1408a877 7133 *
7134 * I think this best serves the needs of
7135 *
7136 * - the people who have no configuration, no keys, and just
7137 * want to try repeated (username,password) pairs until they
7138 * type both correctly
7139 *
7140 * - people who have keys and configuration but occasionally
7141 * need to fall back to passwords
7142 *
7143 * - people with a key held in Pageant, who might not have
7144 * logged in to a particular machine before; so they want to
7145 * type a username, and then _either_ their key will be
7146 * accepted, _or_ they will type a password. If they mistype
7147 * the username they will want to be able to get back and
7148 * retype it!
7cca0d81 7149 */
51470298 7150 s->username[0] = '\0';
7151 s->got_username = FALSE;
a1a1fae4 7152 while (!s->we_are_in) {
1408a877 7153 /*
7154 * Get a username.
7155 */
86916870 7156 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 7157 /*
7158 * We got a username last time round this loop, and
7159 * with change_username turned off we don't try to get
7160 * it again.
7161 */
aa09f7d0 7162 } else if (!*ssh->cfg.username) {
edd0cb8a 7163 int ret; /* need not be kept over crReturn */
7164 s->cur_prompt = new_prompts(ssh->frontend);
7165 s->cur_prompt->to_server = TRUE;
7166 s->cur_prompt->name = dupstr("SSH login name");
7167 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
7168 lenof(s->username));
7169 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7170 while (ret < 0) {
51470298 7171 ssh->send_ok = 1;
edd0cb8a 7172 crWaitUntilV(!pktin);
7173 ret = get_userpass_input(s->cur_prompt, in, inlen);
7174 ssh->send_ok = 0;
32874aea 7175 }
edd0cb8a 7176 if (!ret) {
7177 /*
7178 * get_userpass_input() failed to get a username.
7179 * Terminate.
7180 */
7181 free_prompts(s->cur_prompt);
7182 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7183 crStopV;
7184 }
7185 memcpy(s->username, s->cur_prompt->prompts[0]->result,
7186 lenof(s->username));
7187 free_prompts(s->cur_prompt);
7cca0d81 7188 } else {
57356d63 7189 char *stuff;
86916870 7190 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 7191 s->username[sizeof(s->username)-1] = '\0';
65a22376 7192 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 7193 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 7194 c_write_str(ssh, stuff);
57356d63 7195 sfree(stuff);
7cca0d81 7196 }
7197 }
51470298 7198 s->got_username = TRUE;
7cca0d81 7199
65a22376 7200 /*
1408a877 7201 * Send an authentication request using method "none": (a)
7202 * just in case it succeeds, and (b) so that we know what
7203 * authentication methods we can usefully try next.
65a22376 7204 */
acab36bc 7205 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
51470298 7206
ff3187f6 7207 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7208 ssh2_pkt_addstring(s->pktout, s->username);
7209 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7210 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7211 ssh2_pkt_send(ssh, s->pktout);
51470298 7212 s->type = AUTH_TYPE_NONE;
7213 s->gotit = FALSE;
7214 s->we_are_in = FALSE;
7215
7216 s->tried_pubkey_config = FALSE;
6ac3a551 7217 s->kbd_inter_refused = FALSE;
65a22376 7218
94cd7c3a 7219 /* Reset agent request state. */
7220 s->done_agent = FALSE;
7221 if (s->agent_response) {
7222 if (s->pkblob_in_agent) {
7223 s->agentp = s->pkblob_in_agent;
7224 } else {
7225 s->agentp = s->agent_response + 5 + 4;
7226 s->keyi = 0;
7227 }
7228 }
7229
1408a877 7230 while (1) {
7231 /*
7232 * Wait for the result of the last authentication request.
7233 */
51470298 7234 if (!s->gotit)
ff3187f6 7235 crWaitUntilV(pktin);
6bbce591 7236 /*
7237 * Now is a convenient point to spew any banner material
7238 * that we've accumulated. (This should ensure that when
7239 * we exit the auth loop, we haven't any left to deal
7240 * with.)
7241 */
7242 {
7243 int size = bufchain_size(&ssh->banner);
32874aea 7244 /*
7245 * Don't show the banner if we're operating in
7246 * non-verbose non-interactive mode. (It's probably
7247 * a script, which means nobody will read the
7248 * banner _anyway_, and moreover the printing of
7249 * the banner will screw up processing on the
7250 * output of (say) plink.)
7251 */
6bbce591 7252 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7253 char *banner = snewn(size, char);
7254 bufchain_fetch(&ssh->banner, banner, size);
7255 c_write_untrusted(ssh, banner, size);
7256 sfree(banner);
32874aea 7257 }
6bbce591 7258 bufchain_clear(&ssh->banner);
1408a877 7259 }
ff3187f6 7260 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 7261 logevent("Access granted");
51470298 7262 s->we_are_in = TRUE;
1408a877 7263 break;
7264 }
65a22376 7265
e955d348 7266 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
7267 bombout(("Strange packet received during authentication: "
7268 "type %d", pktin->type));
7ffdbc1a 7269 crStopV;
65a22376 7270 }
7271
51470298 7272 s->gotit = FALSE;
65a22376 7273
1408a877 7274 /*
7275 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7276 * we can look at the string in it and know what we can
7277 * helpfully try next.
7278 */
ff3187f6 7279 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 7280 char *methods;
7281 int methlen;
ff3187f6 7282 ssh_pkt_getstring(pktin, &methods, &methlen);
ff3187f6 7283 if (!ssh2_pkt_getbool(pktin)) {
1408a877 7284 /*
7285 * We have received an unequivocal Access
7286 * Denied. This can translate to a variety of
7287 * messages:
7288 *
7289 * - if we'd just tried "none" authentication,
7290 * it's not worth printing anything at all
7291 *
7292 * - if we'd just tried a public key _offer_,
7293 * the message should be "Server refused our
7294 * key" (or no message at all if the key
7295 * came from Pageant)
7296 *
7297 * - if we'd just tried anything else, the
7298 * message really should be "Access denied".
7299 *
7300 * Additionally, if we'd just tried password
7301 * authentication, we should break out of this
7302 * whole loop so as to go back to the username
91f57d1f 7303 * prompt (iff we're configured to allow
7304 * username change attempts).
1408a877 7305 */
51470298 7306 if (s->type == AUTH_TYPE_NONE) {
1408a877 7307 /* do nothing */
51470298 7308 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7309 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7310 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7311 c_write_str(ssh, "Server refused our key\r\n");
1408a877 7312 logevent("Server refused public key");
51470298 7313 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 7314 /* server declined keyboard-interactive; ignore */
1408a877 7315 } else {
51470298 7316 c_write_str(ssh, "Access denied\r\n");
1408a877 7317 logevent("Access denied");
91f57d1f 7318 if (s->type == AUTH_TYPE_PASSWORD &&
7319 ssh->cfg.change_username) {
6c9dce7c 7320 /* XXX perhaps we should allow
7321 * keyboard-interactive to do this too? */
51470298 7322 s->we_are_in = FALSE;
1408a877 7323 break;
7324 }
7325 }
7326 } else {
51470298 7327 c_write_str(ssh, "Further authentication required\r\n");
1408a877 7328 logevent("Further authentication required");
7329 }
65a22376 7330
51470298 7331 s->can_pubkey =
32874aea 7332 in_commasep_string("publickey", methods, methlen);
51470298 7333 s->can_passwd =
32874aea 7334 in_commasep_string("password", methods, methlen);
86916870 7335 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 7336 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 7337 }
65a22376 7338
acab36bc 7339 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
65a22376 7340
94cd7c3a 7341 if (s->can_pubkey && !s->done_agent && s->nkeys) {
0405e71f 7342
1983e559 7343 /*
94cd7c3a 7344 * Attempt public-key authentication using a key from Pageant.
1983e559 7345 */
1983e559 7346
acab36bc 7347 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 7348
94cd7c3a 7349 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7350
7351 /* Unpack key from agent response */
7352 s->pklen = GET_32BIT(s->agentp);
7353 s->agentp += 4;
7354 s->pkblob = (char *)s->agentp;
7355 s->agentp += s->pklen;
7356 s->alglen = GET_32BIT(s->pkblob);
7357 s->alg = s->pkblob + 4;
7358 s->commentlen = GET_32BIT(s->agentp);
7359 s->agentp += 4;
7360 s->commentp = (char *)s->agentp;
7361 s->agentp += s->commentlen;
7362 /* s->agentp now points at next key, if any */
7363
7364 /* See if server will accept it */
7365 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7366 ssh2_pkt_addstring(s->pktout, s->username);
7367 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7368 /* service requested */
7369 ssh2_pkt_addstring(s->pktout, "publickey");
7370 /* method */
7371 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7372 ssh2_pkt_addstring_start(s->pktout);
7373 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7374 ssh2_pkt_addstring_start(s->pktout);
7375 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7376 ssh2_pkt_send(ssh, s->pktout);
7377 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
1983e559 7378
94cd7c3a 7379 crWaitUntilV(pktin);
7380 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 7381
94cd7c3a 7382 /* Offer of key refused. */
7383 s->gotit = TRUE;
1983e559 7384
94cd7c3a 7385 } else {
7386
7387 void *vret;
1983e559 7388
94cd7c3a 7389 if (flags & FLAG_VERBOSE) {
7390 c_write_str(ssh, "Authenticating with "
7391 "public key \"");
7392 c_write(ssh, s->commentp, s->commentlen);
7393 c_write_str(ssh, "\" from agent\r\n");
7394 }
1983e559 7395
94cd7c3a 7396 /*
7397 * Server is willing to accept the key.
7398 * Construct a SIGN_REQUEST.
7399 */
7400 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7401 ssh2_pkt_addstring(s->pktout, s->username);
7402 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7403 /* service requested */
7404 ssh2_pkt_addstring(s->pktout, "publickey");
7405 /* method */
7406 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7407 ssh2_pkt_addstring_start(s->pktout);
7408 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7409 ssh2_pkt_addstring_start(s->pktout);
7410 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7411
7412 /* Ask agent for signature. */
7413 s->siglen = s->pktout->length - 5 + 4 +
7414 ssh->v2_session_id_len;
7415 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7416 s->siglen -= 4;
7417 s->len = 1; /* message type */
7418 s->len += 4 + s->pklen; /* key blob */
7419 s->len += 4 + s->siglen; /* data to sign */
7420 s->len += 4; /* flags */
7421 s->agentreq = snewn(4 + s->len, char);
7422 PUT_32BIT(s->agentreq, s->len);
7423 s->q = s->agentreq + 4;
7424 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
7425 PUT_32BIT(s->q, s->pklen);
7426 s->q += 4;
7427 memcpy(s->q, s->pkblob, s->pklen);
7428 s->q += s->pklen;
7429 PUT_32BIT(s->q, s->siglen);
7430 s->q += 4;
7431 /* Now the data to be signed... */
7432 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7433 PUT_32BIT(s->q, ssh->v2_session_id_len);
51470298 7434 s->q += 4;
94cd7c3a 7435 }
7436 memcpy(s->q, ssh->v2_session_id,
7437 ssh->v2_session_id_len);
7438 s->q += ssh->v2_session_id_len;
7439 memcpy(s->q, s->pktout->data + 5,
7440 s->pktout->length - 5);
7441 s->q += s->pktout->length - 5;
7442 /* And finally the (zero) flags word. */
7443 PUT_32BIT(s->q, 0);
7444 if (!agent_query(s->agentreq, s->len + 4,
7445 &vret, &s->retlen,
7446 ssh_agent_callback, ssh)) {
7447 do {
7448 crReturnV;
7449 if (pktin) {
7450 bombout(("Unexpected data from server"
7451 " while waiting for agent"
7452 " response"));
7453 crStopV;
1983e559 7454 }
94cd7c3a 7455 } while (pktin || inlen > 0);
7456 vret = ssh->agent_response;
7457 s->retlen = ssh->agent_response_len;
7458 }
7459 s->ret = vret;
7460 sfree(s->agentreq);
7461 if (s->ret) {
7462 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
7463 logevent("Sending Pageant's response");
7464 ssh2_add_sigblob(ssh, s->pktout,
7465 s->pkblob, s->pklen,
7466 s->ret + 9,
7467 GET_32BIT(s->ret + 5));
7468 ssh2_pkt_send(ssh, s->pktout);
7469 s->type = AUTH_TYPE_PUBLICKEY;
7470 } else {
7471 /* FIXME: less drastic response */
7472 bombout(("Pageant failed to answer challenge"));
7473 crStopV;
1983e559 7474 }
7475 }
1983e559 7476 }
94cd7c3a 7477
7478 /* Do we have any keys left to try? */
7479 if (s->pkblob_in_agent) {
7480 s->done_agent = TRUE;
7481 s->tried_pubkey_config = TRUE;
7482 } else {
7483 s->keyi++;
7484 if (s->keyi >= s->nkeys)
7485 s->done_agent = TRUE;
7486 }
1983e559 7487
edd0cb8a 7488 } else if (s->can_pubkey && s->publickey_blob &&
7489 !s->tried_pubkey_config) {
65a22376 7490
edd0cb8a 7491 struct ssh2_userkey *key; /* not live over crReturn */
7492 char *passphrase; /* not live over crReturn */
65a22376 7493
acab36bc 7494 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
00db133f 7495
edd0cb8a 7496 s->tried_pubkey_config = TRUE;
7497
65a22376 7498 /*
1408a877 7499 * Try the public key supplied in the configuration.
7500 *
7501 * First, offer the public blob to see if the server is
7502 * willing to accept it.
65a22376 7503 */
ff3187f6 7504 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7505 ssh2_pkt_addstring(s->pktout, s->username);
edd0cb8a 7506 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7507 /* service requested */
7508 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7509 ssh2_pkt_addbool(s->pktout, FALSE);
7510 /* no signature included */
7511 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7512 ssh2_pkt_addstring_start(s->pktout);
7513 ssh2_pkt_addstring_data(s->pktout,
7514 (char *)s->publickey_blob,
7515 s->publickey_bloblen);
ff3187f6 7516 ssh2_pkt_send(ssh, s->pktout);
edd0cb8a 7517 logevent("Offered public key");
ff3187f6 7518
7519 crWaitUntilV(pktin);
edd0cb8a 7520 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7521 /* Key refused. Give up. */
7522 s->gotit = TRUE; /* reconsider message next loop */
7523 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7524 continue; /* process this new message */
45068b27 7525 }
edd0cb8a 7526 logevent("Offer of public key accepted");
af659722 7527
45068b27 7528 /*
edd0cb8a 7529 * Actually attempt a serious authentication using
7530 * the key.
45068b27 7531 */
edd0cb8a 7532 if (flags & FLAG_VERBOSE) {
7533 c_write_str(ssh, "Authenticating with public key \"");
7534 c_write_str(ssh, s->publickey_comment);
7535 c_write_str(ssh, "\"\r\n");
7536 }
7537 key = NULL;
7538 while (!key) {
7539 const char *error; /* not live over crReturn */
7540 if (s->publickey_encrypted) {
7541 /*
7542 * Get a passphrase from the user.
7543 */
7544 int ret; /* need not be kept over crReturn */
7545 s->cur_prompt = new_prompts(ssh->frontend);
7546 s->cur_prompt->to_server = FALSE;
7547 s->cur_prompt->name = dupstr("SSH key passphrase");
7548 add_prompt(s->cur_prompt,
7549 dupprintf("Passphrase for key \"%.100s\": ",
7550 s->publickey_comment),
7551 FALSE, SSH_MAX_PASSWORD_LEN);
7552 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7553 while (ret < 0) {
7554 ssh->send_ok = 1;
7555 crWaitUntilV(!pktin);
7556 ret = get_userpass_input(s->cur_prompt,
7557 in, inlen);
7558 ssh->send_ok = 0;
7559 }
7560 if (!ret) {
7561 /* Failed to get a passphrase. Terminate. */
7562 free_prompts(s->cur_prompt);
7563 ssh_disconnect(ssh, NULL,
7564 "Unable to authenticate",
7565 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7566 TRUE);
7567 crStopV;
85fdbe25 7568 }
edd0cb8a 7569 passphrase =
7570 dupstr(s->cur_prompt->prompts[0]->result);
7571 free_prompts(s->cur_prompt);
45068b27 7572 } else {
edd0cb8a 7573 passphrase = NULL; /* no passphrase needed */
45068b27 7574 }
1408a877 7575
edd0cb8a 7576 /*
7577 * Try decrypting the key.
7578 */
7579 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7580 &error);
7581 if (passphrase) {
7582 /* burn the evidence */
7583 memset(passphrase, 0, strlen(passphrase));
7584 sfree(passphrase);
7585 }
7586 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7587 if (passphrase &&
7588 (key == SSH2_WRONG_PASSPHRASE)) {
7589 c_write_str(ssh, "Wrong passphrase\r\n");
7590 key = NULL;
7591 /* and loop again */
7592 } else {
7593 c_write_str(ssh, "Unable to load private key (");
7594 c_write_str(ssh, error);
7595 c_write_str(ssh, ")\r\n");
7596 key = NULL;
7597 break; /* try something else */
7598 }
1408a877 7599 }
65a22376 7600 }
65a22376 7601
edd0cb8a 7602 if (key) {
1dd353b5 7603 unsigned char *pkblob, *sigblob, *sigdata;
7604 int pkblob_len, sigblob_len, sigdata_len;
edd0cb8a 7605 int p;
65a22376 7606
1408a877 7607 /*
7608 * We have loaded the private key and the server
7609 * has announced that it's willing to accept it.
7610 * Hallelujah. Generate a signature and send it.
7611 */
ff3187f6 7612 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7613 ssh2_pkt_addstring(s->pktout, s->username);
edd0cb8a 7614 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7615 /* service requested */
7616 ssh2_pkt_addstring(s->pktout, "publickey");
7617 /* method */
ff3187f6 7618 ssh2_pkt_addbool(s->pktout, TRUE);
edd0cb8a 7619 /* signature follows */
ff3187f6 7620 ssh2_pkt_addstring(s->pktout, key->alg->name);
edd0cb8a 7621 pkblob = key->alg->public_blob(key->data,
7622 &pkblob_len);
ff3187f6 7623 ssh2_pkt_addstring_start(s->pktout);
edd0cb8a 7624 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
7625 pkblob_len);
1408a877 7626
7627 /*
7628 * The data to be signed is:
7629 *
7630 * string session-id
7631 *
7632 * followed by everything so far placed in the
7633 * outgoing packet.
7634 */
b672f405 7635 sigdata_len = s->pktout->length - 5 + 4 +
7636 ssh->v2_session_id_len;
edd0cb8a 7637 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7638 sigdata_len -= 4;
92d60585 7639 sigdata = snewn(sigdata_len, unsigned char);
edd0cb8a 7640 p = 0;
7641 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7642 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7643 p += 4;
7644 }
b672f405 7645 memcpy(sigdata+p, ssh->v2_session_id,
7646 ssh->v2_session_id_len);
7647 p += ssh->v2_session_id_len;
ff3187f6 7648 memcpy(sigdata+p, s->pktout->data + 5,
7649 s->pktout->length - 5);
edd0cb8a 7650 p += s->pktout->length - 5;
7651 assert(p == sigdata_len);
d8baa528 7652 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 7653 sigdata_len, &sigblob_len);
ff3187f6 7654 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 7655 sigblob, sigblob_len);
7656 sfree(pkblob);
7657 sfree(sigblob);
1408a877 7658 sfree(sigdata);
7659
ff3187f6 7660 ssh2_pkt_send(ssh, s->pktout);
51470298 7661 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 7662 key->alg->freekey(key->data);
1408a877 7663 }
edd0cb8a 7664
7665 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
7666
7667 /*
7668 * Keyboard-interactive authentication.
7669 */
edd0cb8a 7670
edd0cb8a 7671 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7672
acab36bc 7673 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
edd0cb8a 7674
7675 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7676 ssh2_pkt_addstring(s->pktout, s->username);
7677 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7678 /* service requested */
7679 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
7680 /* method */
7681 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7682 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
7683 ssh2_pkt_send(ssh, s->pktout);
7684
7685 crWaitUntilV(pktin);
7686 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7687 /* Server is not willing to do keyboard-interactive
b8e3173d 7688 * at all (or, bizarrely but legally, accepts the
7689 * user without actually issuing any prompts).
7690 * Give up on it entirely. */
edd0cb8a 7691 s->gotit = TRUE;
7692 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7693 logevent("Keyboard-interactive authentication refused");
7694 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7695 s->kbd_inter_refused = TRUE; /* don't try it again */
7696 continue;
7697 }
7698
7699 /*
b8e3173d 7700 * Loop while the server continues to send INFO_REQUESTs.
edd0cb8a 7701 */
b8e3173d 7702 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
edd0cb8a 7703
b8e3173d 7704 char *name, *inst, *lang;
7705 int name_len, inst_len, lang_len;
7706 int i;
7707
7708 /*
7709 * We've got a fresh USERAUTH_INFO_REQUEST.
7710 * Get the preamble and start building a prompt.
7711 */
7712 ssh_pkt_getstring(pktin, &name, &name_len);
7713 ssh_pkt_getstring(pktin, &inst, &inst_len);
7714 ssh_pkt_getstring(pktin, &lang, &lang_len);
7715 s->cur_prompt = new_prompts(ssh->frontend);
7716 s->cur_prompt->to_server = TRUE;
7717 if (name_len) {
7718 /* FIXME: better prefix to distinguish from
7719 * local prompts? */
7720 s->cur_prompt->name =
7721 dupprintf("SSH server: %.*s", name_len, name);
7722 s->cur_prompt->name_reqd = TRUE;
7723 } else {
7724 s->cur_prompt->name =
7725 dupstr("SSH server authentication");
7726 s->cur_prompt->name_reqd = FALSE;
edd0cb8a 7727 }
b8e3173d 7728 /* FIXME: ugly to print "Using..." in prompt _every_
7729 * time round. Can this be done more subtly? */
7730 s->cur_prompt->instruction =
7731 dupprintf("Using keyboard-interactive authentication.%s%.*s",
7732 inst_len ? "\n" : "", inst_len, inst);
7733 s->cur_prompt->instr_reqd = TRUE;
edd0cb8a 7734
b8e3173d 7735 /*
7736 * Get the prompts from the packet.
7737 */
7738 s->num_prompts = ssh_pkt_getuint32(pktin);
7739 for (i = 0; i < s->num_prompts; i++) {
7740 char *prompt;
7741 int prompt_len;
7742 int echo;
7743 static char noprompt[] =
7744 "<server failed to send prompt>: ";
7745
7746 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7747 echo = ssh2_pkt_getbool(pktin);
7748 if (!prompt_len) {
7749 prompt = noprompt;
7750 prompt_len = lenof(noprompt)-1;
7751 }
7752 add_prompt(s->cur_prompt,
7753 dupprintf("%.*s", prompt_len, prompt),
7754 echo, SSH_MAX_PASSWORD_LEN);
edd0cb8a 7755 }
b8e3173d 7756
7757 /*
7758 * Get the user's responses.
7759 */
7760 if (s->num_prompts) {
7761 int ret; /* not live over crReturn */
7762 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7763 while (ret < 0) {
7764 ssh->send_ok = 1;
7765 crWaitUntilV(!pktin);
7766 ret = get_userpass_input(s->cur_prompt, in, inlen);
7767 ssh->send_ok = 0;
7768 }
7769 if (!ret) {
7770 /*
7771 * Failed to get responses. Terminate.
7772 */
7773 free_prompts(s->cur_prompt);
7774 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7775 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7776 TRUE);
7777 crStopV;
7778 }
edd0cb8a 7779 }
b8e3173d 7780
7781 /*
7782 * Send the responses to the server.
7783 */
7784 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
b8e3173d 7785 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7786 for (i=0; i < s->num_prompts; i++) {
7787 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7788 ssh2_pkt_addstring(s->pktout,
7789 s->cur_prompt->prompts[i]->result);
7790 end_log_omission(ssh, s->pktout);
7791 }
18524056 7792 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
b8e3173d 7793
7794 /*
7795 * Get the next packet in case it's another
7796 * INFO_REQUEST.
7797 */
7798 crWaitUntilV(pktin);
7799
edd0cb8a 7800 }
7801
7802 /*
b8e3173d 7803 * We should have SUCCESS or FAILURE now.
edd0cb8a 7804 */
b8e3173d 7805 s->gotit = TRUE;
edd0cb8a 7806
7807 } else if (s->can_passwd) {
7808
7809 /*
7810 * Plain old password authentication.
7811 */
7812 int ret; /* not live over crReturn */
e955d348 7813 int changereq_first_time; /* not live over crReturn */
edd0cb8a 7814
acab36bc 7815 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
edd0cb8a 7816
7817 s->cur_prompt = new_prompts(ssh->frontend);
7818 s->cur_prompt->to_server = TRUE;
7819 s->cur_prompt->name = dupstr("SSH password");
7820 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
7821 s->username,
7822 ssh->savedhost),
7823 FALSE, SSH_MAX_PASSWORD_LEN);
7824
7825 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7826 while (ret < 0) {
7827 ssh->send_ok = 1;
7828 crWaitUntilV(!pktin);
7829 ret = get_userpass_input(s->cur_prompt, in, inlen);
7830 ssh->send_ok = 0;
7831 }
7832 if (!ret) {
7833 /*
7834 * Failed to get responses. Terminate.
7835 */
7836 free_prompts(s->cur_prompt);
7837 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7838 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7839 TRUE);
7840 crStopV;
7841 }
e955d348 7842 /*
7843 * Squirrel away the password. (We may need it later if
7844 * asked to change it.)
7845 */
7846 s->password = dupstr(s->cur_prompt->prompts[0]->result);
7847 free_prompts(s->cur_prompt);
edd0cb8a 7848
7849 /*
7850 * Send the password packet.
7851 *
95d2d262 7852 * We pad out the password packet to 256 bytes to make
7853 * it harder for an attacker to find the length of the
7854 * user's password.
1408a877 7855 *
95d2d262 7856 * Anyone using a password longer than 256 bytes
7857 * probably doesn't have much to worry about from
1408a877 7858 * people who find out how long their password is!
65a22376 7859 */
ff3187f6 7860 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7861 ssh2_pkt_addstring(s->pktout, s->username);
edd0cb8a 7862 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7863 /* service requested */
ff3187f6 7864 ssh2_pkt_addstring(s->pktout, "password");
7865 ssh2_pkt_addbool(s->pktout, FALSE);
7866 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
e955d348 7867 ssh2_pkt_addstring(s->pktout, s->password);
ff3187f6 7868 end_log_omission(ssh, s->pktout);
18524056 7869 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
0d43337a 7870 logevent("Sent password");
28f4d4f0 7871 s->type = AUTH_TYPE_PASSWORD;
edd0cb8a 7872
e955d348 7873 /*
7874 * Wait for next packet, in case it's a password change
7875 * request.
7876 */
7877 crWaitUntilV(pktin);
7878 changereq_first_time = TRUE;
7879
7880 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
7881
7882 /*
7883 * We're being asked for a new password
7884 * (perhaps not for the first time).
7885 * Loop until the server accepts it.
7886 */
7887
7888 int got_new = FALSE; /* not live over crReturn */
7889 char *prompt; /* not live over crReturn */
7890 int prompt_len; /* not live over crReturn */
7891
7892 {
7893 char *msg;
7894 if (changereq_first_time)
7895 msg = "Server requested password change";
7896 else
7897 msg = "Server rejected new password";
7898 logevent(msg);
7899 c_write_str(ssh, msg);
7900 c_write_str(ssh, "\r\n");
7901 }
7902
7903 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7904
7905 s->cur_prompt = new_prompts(ssh->frontend);
7906 s->cur_prompt->to_server = TRUE;
7907 s->cur_prompt->name = dupstr("New SSH password");
7908 s->cur_prompt->instruction =
7909 dupprintf("%.*s", prompt_len, prompt);
7910 s->cur_prompt->instr_reqd = TRUE;
d9add7bc 7911 /*
7912 * There's no explicit requirement in the protocol
7913 * for the "old" passwords in the original and
7914 * password-change messages to be the same, and
7915 * apparently some Cisco kit supports password change
7916 * by the user entering a blank password originally
7917 * and the real password subsequently, so,
7918 * reluctantly, we prompt for the old password again.
7919 *
7920 * (On the other hand, some servers don't even bother
7921 * to check this field.)
7922 */
7923 add_prompt(s->cur_prompt,
7924 dupstr("Current password (blank for previously entered password): "),
7925 FALSE, SSH_MAX_PASSWORD_LEN);
e955d348 7926 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
7927 FALSE, SSH_MAX_PASSWORD_LEN);
7928 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
7929 FALSE, SSH_MAX_PASSWORD_LEN);
7930
7931 /*
7932 * Loop until the user manages to enter the same
7933 * password twice.
7934 */
7935 while (!got_new) {
7936
7937 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7938 while (ret < 0) {
7939 ssh->send_ok = 1;
7940 crWaitUntilV(!pktin);
7941 ret = get_userpass_input(s->cur_prompt, in, inlen);
7942 ssh->send_ok = 0;
7943 }
7944 if (!ret) {
7945 /*
7946 * Failed to get responses. Terminate.
7947 */
7948 /* burn the evidence */
7949 free_prompts(s->cur_prompt);
7950 memset(s->password, 0, strlen(s->password));
7951 sfree(s->password);
7952 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7953 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7954 TRUE);
7955 crStopV;
7956 }
7957
7958 /*
d9add7bc 7959 * If the user specified a new original password
7960 * (IYSWIM), overwrite any previously specified
7961 * one.
7962 * (A side effect is that the user doesn't have to
7963 * re-enter it if they louse up the new password.)
7964 */
7965 if (s->cur_prompt->prompts[0]->result[0]) {
7966 memset(s->password, 0, strlen(s->password));
7967 /* burn the evidence */
7968 sfree(s->password);
7969 s->password =
7970 dupstr(s->cur_prompt->prompts[0]->result);
7971 }
7972
7973 /*
7974 * Check the two new passwords match.
e955d348 7975 */
d9add7bc 7976 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
7977 s->cur_prompt->prompts[2]->result)
e955d348 7978 == 0);
7979 if (!got_new)
7980 /* They don't. Silly user. */
7981 c_write_str(ssh, "Passwords do not match\r\n");
7982
7983 }
7984
7985 /*
7986 * Send the new password (along with the old one).
7987 * (see above for padding rationale)
7988 */
7989 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
e955d348 7990 ssh2_pkt_addstring(s->pktout, s->username);
7991 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7992 /* service requested */
7993 ssh2_pkt_addstring(s->pktout, "password");
7994 ssh2_pkt_addbool(s->pktout, TRUE);
7995 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7996 ssh2_pkt_addstring(s->pktout, s->password);
7997 ssh2_pkt_addstring(s->pktout,
d9add7bc 7998 s->cur_prompt->prompts[1]->result);
e955d348 7999 free_prompts(s->cur_prompt);
8000 end_log_omission(ssh, s->pktout);
18524056 8001 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
e955d348 8002 logevent("Sent new password");
8003
8004 /*
8005 * Now see what the server has to say about it.
8006 * (If it's CHANGEREQ again, it's not happy with the
8007 * new password.)
8008 */
8009 crWaitUntilV(pktin);
8010 changereq_first_time = FALSE;
8011
8012 }
8013
8014 /*
8015 * We need to reexamine the current pktin at the top
8016 * of the loop. Either:
8017 * - we weren't asked to change password at all, in
8018 * which case it's a SUCCESS or FAILURE with the
8019 * usual meaning
8020 * - we sent a new password, and the server was
8021 * either OK with it (SUCCESS or FAILURE w/partial
8022 * success) or unhappy with the _old_ password
8023 * (FAILURE w/o partial success)
8024 * In any of these cases, we go back to the top of
8025 * the loop and start again.
8026 */
8027 s->gotit = TRUE;
8028
8029 /*
8030 * We don't need the old password any more, in any
8031 * case. Burn the evidence.
8032 */
8033 memset(s->password, 0, strlen(s->password));
8034 sfree(s->password);
8035
1408a877 8036 } else {
edd0cb8a 8037
9e296bfa 8038 ssh_disconnect(ssh, NULL,
8039 "No supported authentication methods available",
8040 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
8041 FALSE);
7ffdbc1a 8042 crStopV;
edd0cb8a 8043
65a22376 8044 }
edd0cb8a 8045
65a22376 8046 }
a1a1fae4 8047 }
6bbce591 8048 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7cca0d81 8049
edd0cb8a 8050 /* Clear up various bits and pieces from authentication. */
8051 if (s->publickey_blob) {
8052 sfree(s->publickey_blob);
8053 sfree(s->publickey_comment);
8054 }
94cd7c3a 8055 if (s->agent_response)
8056 sfree(s->agent_response);
edd0cb8a 8057
7cca0d81 8058 /*
a1a1fae4 8059 * Now the connection protocol has started, one way or another.
7cca0d81 8060 */
8061
0ed48730 8062 ssh->channels = newtree234(ssh_channelcmp);
8063
7cca0d81 8064 /*
b09eaa88 8065 * Set up handlers for some connection protocol messages, so we
8066 * don't have to handle them repeatedly in this coroutine.
8067 */
8068 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
8069 ssh2_msg_channel_window_adjust;
51df0ab5 8070 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
8071 ssh2_msg_global_request;
b09eaa88 8072
8073 /*
0ed48730 8074 * Create the main session channel.
7cca0d81 8075 */
feb02b4e 8076 if (ssh->cfg.ssh_no_shell) {
8077 ssh->mainchan = NULL;
8078 } else if (*ssh->cfg.ssh_nc_host) {
8079 /*
8080 * Just start a direct-tcpip channel and use it as the main
8081 * channel.
8082 */
8083 ssh->mainchan = snew(struct ssh_channel);
8084 ssh->mainchan->ssh = ssh;
8085 ssh->mainchan->localid = alloc_channel_id(ssh);
23828b7e 8086 logeventf(ssh,
8087 "Opening direct-tcpip channel to %s:%d in place of session",
8088 ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port);
feb02b4e 8089 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8090 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
8091 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
9b53e9b8 8092 ssh->mainchan->v.v2.locwindow = ssh->mainchan->v.v2.locmaxwin =
0e443c99 8093 ssh->mainchan->v.v2.remlocwin =
9b53e9b8 8094 ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
0e443c99 8095 ssh->mainchan->v.v2.winadj_head = NULL;
8096 ssh->mainchan->v.v2.winadj_tail = NULL;
8097 ssh->mainchan->v.v2.throttle_state = UNTHROTTLED;
feb02b4e 8098 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8099 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8100 ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host);
8101 ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port);
8102 /*
23828b7e 8103 * There's nothing meaningful to put in the originator
8104 * fields, but some servers insist on syntactically correct
8105 * information.
feb02b4e 8106 */
8107 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
8108 ssh2_pkt_adduint32(s->pktout, 0);
8109 ssh2_pkt_send(ssh, s->pktout);
8110
8111 crWaitUntilV(pktin);
8112 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8113 bombout(("Server refused to open a direct-tcpip channel"));
8114 crStopV;
8115 /* FIXME: error data comes back in FAILURE packet */
8116 }
8117 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8118 bombout(("Server's channel confirmation cited wrong channel"));
8119 crStopV;
8120 }
8121 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8122 ssh->mainchan->halfopen = FALSE;
8123 ssh->mainchan->type = CHAN_MAINSESSION;
8124 ssh->mainchan->closes = 0;
8125 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8126 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8127 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
8128 add234(ssh->channels, ssh->mainchan);
8129 update_specials_menu(ssh->frontend);
23828b7e 8130 logevent("Opened direct-tcpip channel");
feb02b4e 8131 ssh->ncmode = TRUE;
8132 } else {
0ed48730 8133 ssh->mainchan = snew(struct ssh_channel);
8134 ssh->mainchan->ssh = ssh;
8135 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 8136 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8137 ssh2_pkt_addstring(s->pktout, "session");
8138 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
9b53e9b8 8139 ssh->mainchan->v.v2.locwindow = ssh->mainchan->v.v2.locmaxwin =
0e443c99 8140 ssh->mainchan->v.v2.remlocwin =
9b53e9b8 8141 ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
0e443c99 8142 ssh->mainchan->v.v2.winadj_head = NULL;
8143 ssh->mainchan->v.v2.winadj_tail = NULL;
8144 ssh->mainchan->v.v2.throttle_state = UNTHROTTLED;
ff3187f6 8145 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 8146 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 8147 ssh2_pkt_send(ssh, s->pktout);
8148 crWaitUntilV(pktin);
8149 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 8150 bombout(("Server refused to open a session"));
8151 crStopV;
8152 /* FIXME: error data comes back in FAILURE packet */
8153 }
ff3187f6 8154 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 8155 bombout(("Server's channel confirmation cited wrong channel"));
8156 crStopV;
8157 }
ff3187f6 8158 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 8159 ssh->mainchan->halfopen = FALSE;
0ed48730 8160 ssh->mainchan->type = CHAN_MAINSESSION;
8161 ssh->mainchan->closes = 0;
ff3187f6 8162 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8163 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 8164 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
8165 add234(ssh->channels, ssh->mainchan);
62638676 8166 update_specials_menu(ssh->frontend);
0ed48730 8167 logevent("Opened channel for session");
feb02b4e 8168 ssh->ncmode = FALSE;
8169 }
7cca0d81 8170
8171 /*
51df0ab5 8172 * Now we have a channel, make dispatch table entries for
8173 * general channel-based messages.
8174 */
8175 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8176 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8177 ssh2_msg_channel_data;
8178 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8179 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8180 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8181 ssh2_msg_channel_open_confirmation;
8182 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8183 ssh2_msg_channel_open_failure;
8184 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8185 ssh2_msg_channel_request;
8186 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8187 ssh2_msg_channel_open;
8188
3361b80a 8189 if (ssh->cfg.ssh_simple) {
8190 /*
8191 * This message indicates to the server that we promise
8192 * not to try to run any other channel in parallel with
8193 * this one, so it's safe for it to advertise a very large
8194 * window and leave the flow control to TCP.
8195 */
8196 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8197 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8198 ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
8199 ssh2_pkt_addbool(s->pktout, 0); /* no reply */
8200 ssh2_pkt_send(ssh, s->pktout);
8201 }
8202
51df0ab5 8203 /*
783415f8 8204 * Potentially enable X11 forwarding.
8205 */
feb02b4e 8206 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward) {
32874aea 8207 char proto[20], data[64];
8208 logevent("Requesting X11 forwarding");
302121de 8209 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 8210 data, sizeof(data), ssh->cfg.x11_auth);
8211 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 8212 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8213 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8214 ssh2_pkt_addstring(s->pktout, "x11-req");
8215 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8216 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8217 ssh2_pkt_addstring(s->pktout, proto);
f68353be 8218 /*
8219 * Note that while we blank the X authentication data here, we don't
8220 * take any special action to blank the start of an X11 channel,
8221 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
8222 * without having session blanking enabled is likely to leak your
8223 * cookie into the log.
8224 */
178c3872 8225 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
ff3187f6 8226 ssh2_pkt_addstring(s->pktout, data);
178c3872 8227 end_log_omission(ssh, s->pktout);
ff3187f6 8228 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
8229 ssh2_pkt_send(ssh, s->pktout);
32874aea 8230
b09eaa88 8231 crWaitUntilV(pktin);
32874aea 8232
ff3187f6 8233 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8234 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 8235 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 8236 " packet type %d", pktin->type));
7ffdbc1a 8237 crStopV;
32874aea 8238 }
8239 logevent("X11 forwarding refused");
8240 } else {
8241 logevent("X11 forwarding enabled");
51470298 8242 ssh->X11_fwd_enabled = TRUE;
32874aea 8243 }
783415f8 8244 }
8245
8246 /*
bc240b21 8247 * Enable port forwardings.
8248 */
06fadff5 8249 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 8250
8251 /*
36c2a3e9 8252 * Potentially enable agent forwarding.
8253 */
feb02b4e 8254 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) {
32874aea 8255 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 8256 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8257 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8258 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
8259 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8260 ssh2_pkt_send(ssh, s->pktout);
32874aea 8261
b09eaa88 8262 crWaitUntilV(pktin);
32874aea 8263
ff3187f6 8264 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8265 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 8266 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 8267 " packet type %d", pktin->type));
7ffdbc1a 8268 crStopV;
32874aea 8269 }
8270 logevent("Agent forwarding refused");
8271 } else {
8272 logevent("Agent forwarding enabled");
51470298 8273 ssh->agentfwd_enabled = TRUE;
32874aea 8274 }
36c2a3e9 8275 }
8276
8277 /*
7cca0d81 8278 * Now allocate a pty for the session.
8279 */
feb02b4e 8280 if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) {
a5dd8467 8281 /* Unpick the terminal-speed string. */
8282 /* XXX perhaps we should allow no speeds to be sent. */
db219738 8283 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8284 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 8285 /* Build the pty request. */
ff3187f6 8286 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8287 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8288 ssh2_pkt_addstring(s->pktout, "pty-req");
8289 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8290 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
8291 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
8292 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
8293 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
8294 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
8295 ssh2_pkt_addstring_start(s->pktout);
c6ccd5c2 8296 parse_ttymodes(ssh, ssh->cfg.ttymodes,
8297 ssh2_send_ttymode, (void *)s->pktout);
8298 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
ff3187f6 8299 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
c6ccd5c2 8300 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
ff3187f6 8301 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
8302 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
8303 ssh2_pkt_send(ssh, s->pktout);
51470298 8304 ssh->state = SSH_STATE_INTERMED;
32874aea 8305
b09eaa88 8306 crWaitUntilV(pktin);
32874aea 8307
ff3187f6 8308 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8309 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 8310 bombout(("Unexpected response to pty request:"
ff3187f6 8311 " packet type %d", pktin->type));
7ffdbc1a 8312 crStopV;
32874aea 8313 }
51470298 8314 c_write_str(ssh, "Server refused to allocate pty\r\n");
8315 ssh->editing = ssh->echoing = 1;
32874aea 8316 } else {
a5dd8467 8317 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 8318 ssh->ospeed, ssh->ispeed);
32874aea 8319 }
0965bee0 8320 } else {
51470298 8321 ssh->editing = ssh->echoing = 1;
7cca0d81 8322 }
8323
8324 /*
73feed4f 8325 * Send environment variables.
8326 *
8327 * Simplest thing here is to send all the requests at once, and
8328 * then wait for a whole bunch of successes or failures.
8329 */
feb02b4e 8330 if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) {
73feed4f 8331 char *e = ssh->cfg.environmt;
8332 char *var, *varend, *val;
8333
8334 s->num_env = 0;
8335
8336 while (*e) {
8337 var = e;
8338 while (*e && *e != '\t') e++;
8339 varend = e;
8340 if (*e == '\t') e++;
8341 val = e;
8342 while (*e) e++;
8343 e++;
8344
ff3187f6 8345 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8346 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8347 ssh2_pkt_addstring(s->pktout, "env");
8348 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8349 ssh2_pkt_addstring_start(s->pktout);
8350 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
8351 ssh2_pkt_addstring(s->pktout, val);
8352 ssh2_pkt_send(ssh, s->pktout);
73feed4f 8353
8354 s->num_env++;
8355 }
8356
8357 logeventf(ssh, "Sent %d environment variables", s->num_env);
8358
8359 s->env_ok = 0;
8360 s->env_left = s->num_env;
8361
8362 while (s->env_left > 0) {
b09eaa88 8363 crWaitUntilV(pktin);
73feed4f 8364
ff3187f6 8365 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8366 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 8367 bombout(("Unexpected response to environment request:"
ff3187f6 8368 " packet type %d", pktin->type));
73feed4f 8369 crStopV;
8370 }
8371 } else {
8372 s->env_ok++;
8373 }
8374
8375 s->env_left--;
8376 }
8377
8378 if (s->env_ok == s->num_env) {
8379 logevent("All environment variables successfully set");
8380 } else if (s->env_ok == 0) {
8381 logevent("All environment variables refused");
8382 c_write_str(ssh, "Server refused to set environment variables\r\n");
8383 } else {
8384 logeventf(ssh, "%d environment variables refused",
8385 s->num_env - s->env_ok);
8386 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8387 }
8388 }
8389
8390 /*
fd5e5847 8391 * Start a shell or a remote command. We may have to attempt
8392 * this twice if the config data has provided a second choice
8393 * of command.
7cca0d81 8394 */
feb02b4e 8395 if (ssh->mainchan && !ssh->ncmode) while (1) {
fd5e5847 8396 int subsys;
8397 char *cmd;
8398
51470298 8399 if (ssh->fallback_cmd) {
86916870 8400 subsys = ssh->cfg.ssh_subsys2;
8401 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 8402 } else {
86916870 8403 subsys = ssh->cfg.ssh_subsys;
8404 cmd = ssh->cfg.remote_cmd_ptr;
04c52f10 8405 if (!cmd) cmd = ssh->cfg.remote_cmd;
fd5e5847 8406 }
8407
ff3187f6 8408 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8409 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 8410 if (subsys) {
ff3187f6 8411 ssh2_pkt_addstring(s->pktout, "subsystem");
8412 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8413 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 8414 } else if (*cmd) {
ff3187f6 8415 ssh2_pkt_addstring(s->pktout, "exec");
8416 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8417 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 8418 } else {
ff3187f6 8419 ssh2_pkt_addstring(s->pktout, "shell");
8420 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 8421 }
ff3187f6 8422 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 8423
8424 crWaitUntilV(pktin);
8425
ff3187f6 8426 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8427 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 8428 bombout(("Unexpected response to shell/command request:"
ff3187f6 8429 " packet type %d", pktin->type));
7ffdbc1a 8430 crStopV;
fd5e5847 8431 }
8432 /*
8433 * We failed to start the command. If this is the
8434 * fallback command, we really are finished; if it's
8435 * not, and if the fallback command exists, try falling
8436 * back to it before complaining.
8437 */
86916870 8438 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 8439 logevent("Primary command failed; attempting fallback");
51470298 8440 ssh->fallback_cmd = TRUE;
fd5e5847 8441 continue;
8442 }
6b5cf8b4 8443 bombout(("Server refused to start a shell/command"));
7ffdbc1a 8444 crStopV;
fd5e5847 8445 } else {
8446 logevent("Started a shell/command");
32874aea 8447 }
fd5e5847 8448 break;
7cca0d81 8449 }
8450
51470298 8451 ssh->state = SSH_STATE_SESSION;
8452 if (ssh->size_needed)
8453 ssh_size(ssh, ssh->term_width, ssh->term_height);
8454 if (ssh->eof_needed)
8455 ssh_special(ssh, TS_EOF);
6e48c3fe 8456
7cca0d81 8457 /*
0e443c99 8458 * All the initial channel requests are done, so install the default
8459 * failure handler.
8460 */
8461 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure;
8462
8463 /*
7cca0d81 8464 * Transfer data!
8465 */
b9d7bcad 8466 if (ssh->ldisc)
8467 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 8468 if (ssh->mainchan)
8469 ssh->send_ok = 1;
7cca0d81 8470 while (1) {
e5574168 8471 crReturnV;
51470298 8472 s->try_send = FALSE;
ff3187f6 8473 if (pktin) {
2b7540a7 8474
51df0ab5 8475 /*
8476 * _All_ the connection-layer packets we expect to
8477 * receive are now handled by the dispatch table.
8478 * Anything that reaches here must be bogus.
8479 */
32874aea 8480
51df0ab5 8481 bombout(("Strange packet received: type %d", pktin->type));
8482 crStopV;
0ed48730 8483 } else if (ssh->mainchan) {
32874aea 8484 /*
8485 * We have spare data. Add it to the channel buffer.
8486 */
d8baa528 8487 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 8488 s->try_send = TRUE;
32874aea 8489 }
51470298 8490 if (s->try_send) {
32874aea 8491 int i;
8492 struct ssh_channel *c;
8493 /*
8494 * Try to send data on all channels if we can.
8495 */
1bfc7e93 8496 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
8497 ssh2_try_send_and_unthrottle(c);
7cca0d81 8498 }
e5574168 8499 }
8500
8501 crFinishV;
8502}
8503
8504/*
2e85c969 8505 * Handlers for SSH-2 messages that might arrive at any moment.
b09eaa88 8506 */
409bfa77 8507static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 8508{
8509 /* log reason code in disconnect message */
8510 char *buf, *msg;
8511 int nowlen, reason, msglen;
8512
8513 reason = ssh_pkt_getuint32(pktin);
8514 ssh_pkt_getstring(pktin, &msg, &msglen);
8515
8516 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
8517 buf = dupprintf("Received disconnect message (%s)",
8518 ssh2_disconnect_reasons[reason]);
8519 } else {
8520 buf = dupprintf("Received disconnect message (unknown"
8521 " type %d)", reason);
8522 }
8523 logevent(buf);
8524 sfree(buf);
8525 buf = dupprintf("Disconnection message text: %n%.*s",
8526 &nowlen, msglen, msg);
8527 logevent(buf);
8528 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
8529 reason,
8530 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
8531 ssh2_disconnect_reasons[reason] : "unknown",
8532 buf+nowlen));
8533 sfree(buf);
8534}
8535
409bfa77 8536static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 8537{
8538 /* log the debug message */
fb983202 8539 char *msg;
b09eaa88 8540 int msglen;
8541 int always_display;
8542
8543 /* XXX maybe we should actually take notice of this */
8544 always_display = ssh2_pkt_getbool(pktin);
8545 ssh_pkt_getstring(pktin, &msg, &msglen);
8546
fb983202 8547 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 8548}
8549
409bfa77 8550static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 8551{
8552 struct Packet *pktout;
8553 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
8554 ssh2_pkt_adduint32(pktout, pktin->sequence);
8555 /*
8556 * UNIMPLEMENTED messages MUST appear in the same order as the
8557 * messages they respond to. Hence, never queue them.
8558 */
8559 ssh2_pkt_send_noqueue(ssh, pktout);
8560}
8561
8562/*
2e85c969 8563 * Handle the top-level SSH-2 protocol.
7cca0d81 8564 */
b09eaa88 8565static void ssh2_protocol_setup(Ssh ssh)
8566{
8567 int i;
8568
8569 /*
8570 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
8571 */
8572 for (i = 0; i < 256; i++)
8573 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
8574
8575 /*
8576 * Any message we actually understand, we set to NULL so that
8577 * the coroutines will get it.
8578 */
8579 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
8580 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
8581 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
8582 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
8583 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
8584 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
8585 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
8586 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
8587 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
8588 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
8589 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
8590 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
8591 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
8592 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
8593 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
8594 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
8595 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
8596 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
8597 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
8598 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
8599 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
8600 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
8601 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
8602 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
8603 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
8604 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
8605 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
8606 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
8607 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
8608 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
8609 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
8610 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
8611 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
8612
8613 /*
8614 * These special message types we install handlers for.
8615 */
8616 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
2e85c969 8617 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
b09eaa88 8618 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
8619}
8620
9442dd57 8621static void ssh2_timer(void *ctx, long now)
8622{
8623 Ssh ssh = (Ssh)ctx;
8624
ecbb0000 8625 if (ssh->state == SSH_STATE_CLOSED)
8626 return;
8627
e6c1536e 8628 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 8629 now - ssh->next_rekey >= 0) {
f382c87d 8630 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 8631 }
8632}
8633
1c1a7262 8634static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 8635 struct Packet *pktin)
7cca0d81 8636{
1c1a7262 8637 unsigned char *in = (unsigned char *)vin;
b09eaa88 8638 if (ssh->state == SSH_STATE_CLOSED)
8639 return;
8640
9442dd57 8641 if (pktin) {
8642 ssh->incoming_data_size += pktin->encrypted_len;
8643 if (!ssh->kex_in_progress &&
d57f70af 8644 ssh->max_data_size != 0 &&
8645 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 8646 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 8647 }
8648
b09eaa88 8649 if (pktin && ssh->packet_dispatch[pktin->type]) {
8650 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 8651 return;
b09eaa88 8652 }
8653
8654 if (!ssh->protocol_initial_phase_done ||
8655 (pktin && pktin->type >= 20 && pktin->type < 50)) {
8656 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
8657 !ssh->protocol_initial_phase_done) {
8658 ssh->protocol_initial_phase_done = TRUE;
8659 /*
8660 * Allow authconn to initialise itself.
8661 */
8662 do_ssh2_authconn(ssh, NULL, 0, NULL);
8663 }
8664 } else {
8665 do_ssh2_authconn(ssh, in, inlen, pktin);
8666 }
7cca0d81 8667}
8668
8669/*
8df7a775 8670 * Called to set up the connection.
374330e2 8671 *
8672 * Returns an error message, or NULL on success.
374330e2 8673 */
cbe2d68f 8674static const char *ssh_init(void *frontend_handle, void **backend_handle,
8675 Config *cfg,
79bf227b 8676 char *host, int port, char **realhost, int nodelay,
8677 int keepalive)
32874aea 8678{
cbe2d68f 8679 const char *p;
51470298 8680 Ssh ssh;
8681
3d88e64d 8682 ssh = snew(struct ssh_tag);
86916870 8683 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 8684 ssh->version = 0; /* when not ready yet */
51470298 8685 ssh->s = NULL;
8686 ssh->cipher = NULL;
371e569c 8687 ssh->v1_cipher_ctx = NULL;
0183b242 8688 ssh->crcda_ctx = NULL;
51470298 8689 ssh->cscipher = NULL;
371e569c 8690 ssh->cs_cipher_ctx = NULL;
51470298 8691 ssh->sccipher = NULL;
371e569c 8692 ssh->sc_cipher_ctx = NULL;
51470298 8693 ssh->csmac = NULL;
a8327734 8694 ssh->cs_mac_ctx = NULL;
51470298 8695 ssh->scmac = NULL;
e0e1a00d 8696 ssh->sc_mac_ctx = NULL;
51470298 8697 ssh->cscomp = NULL;
5366aed8 8698 ssh->cs_comp_ctx = NULL;
51470298 8699 ssh->sccomp = NULL;
5366aed8 8700 ssh->sc_comp_ctx = NULL;
51470298 8701 ssh->kex = NULL;
389aa499 8702 ssh->kex_ctx = NULL;
51470298 8703 ssh->hostkey = NULL;
8704 ssh->exitcode = -1;
ac934965 8705 ssh->close_expected = FALSE;
9e296bfa 8706 ssh->clean_exit = FALSE;
51470298 8707 ssh->state = SSH_STATE_PREPACKET;
8708 ssh->size_needed = FALSE;
8709 ssh->eof_needed = FALSE;
b9d7bcad 8710 ssh->ldisc = NULL;
a8327734 8711 ssh->logctx = NULL;
51470298 8712 ssh->deferred_send_data = NULL;
8713 ssh->deferred_len = 0;
8714 ssh->deferred_size = 0;
8715 ssh->fallback_cmd = 0;
acab36bc 8716 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
8717 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
302121de 8718 ssh->x11auth = NULL;
be738459 8719 ssh->v1_compressing = FALSE;
51470298 8720 ssh->v2_outgoing_sequence = 0;
8721 ssh->ssh1_rdpkt_crstate = 0;
8722 ssh->ssh2_rdpkt_crstate = 0;
8723 ssh->do_ssh_init_crstate = 0;
8724 ssh->ssh_gotdata_crstate = 0;
b09eaa88 8725 ssh->do_ssh1_connection_crstate = 0;
51470298 8726 ssh->do_ssh1_login_crstate = 0;
8727 ssh->do_ssh2_transport_crstate = 0;
8728 ssh->do_ssh2_authconn_crstate = 0;
8729 ssh->do_ssh_init_state = NULL;
8730 ssh->do_ssh1_login_state = NULL;
8731 ssh->do_ssh2_transport_state = NULL;
8732 ssh->do_ssh2_authconn_state = NULL;
4320baf7 8733 ssh->v_c = NULL;
8734 ssh->v_s = NULL;
6571dbfd 8735 ssh->mainchan = NULL;
968d2d92 8736 ssh->throttled_all = 0;
8737 ssh->v1_stdout_throttling = 0;
590f6a5f 8738 ssh->queue = NULL;
8739 ssh->queuelen = ssh->queuesize = 0;
8740 ssh->queueing = FALSE;
06fadff5 8741 ssh->qhead = ssh->qtail = NULL;
e13bba36 8742 ssh->deferred_rekey_reason = NULL;
3d9449a1 8743 bufchain_init(&ssh->queued_incoming_data);
8744 ssh->frozen = FALSE;
51470298 8745
8746 *backend_handle = ssh;
32874aea 8747
8f203108 8748#ifdef MSCRYPTOAPI
32874aea 8749 if (crypto_startup() == 0)
8f203108 8750 return "Microsoft high encryption pack not installed!";
8751#endif
374330e2 8752
51470298 8753 ssh->frontend = frontend_handle;
86916870 8754 ssh->term_width = ssh->cfg.width;
8755 ssh->term_height = ssh->cfg.height;
887035a5 8756
fabd1805 8757 ssh->channels = NULL;
8758 ssh->rportfwds = NULL;
f47a5ffb 8759 ssh->portfwds = NULL;
fabd1805 8760
51470298 8761 ssh->send_ok = 0;
8762 ssh->editing = 0;
8763 ssh->echoing = 0;
8764 ssh->v1_throttle_count = 0;
8765 ssh->overall_bufsize = 0;
8766 ssh->fallback_cmd = 0;
8df7a775 8767
3648d4c5 8768 ssh->protocol = NULL;
8769
b09eaa88 8770 ssh->protocol_initial_phase_done = FALSE;
8771
39934deb 8772 ssh->pinger = NULL;
8773
9442dd57 8774 ssh->incoming_data_size = ssh->outgoing_data_size =
8775 ssh->deferred_data_size = 0L;
d57f70af 8776 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 8777 ssh->kex_in_progress = FALSE;
8778
79bf227b 8779 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 8780 if (p != NULL)
8781 return p;
374330e2 8782
5d17ccfc 8783 random_ref();
8784
374330e2 8785 return NULL;
8786}
8787
fabd1805 8788static void ssh_free(void *handle)
8789{
8790 Ssh ssh = (Ssh) handle;
8791 struct ssh_channel *c;
8792 struct ssh_rportfwd *pf;
8793
8794 if (ssh->v1_cipher_ctx)
8795 ssh->cipher->free_context(ssh->v1_cipher_ctx);
8796 if (ssh->cs_cipher_ctx)
8797 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
8798 if (ssh->sc_cipher_ctx)
8799 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
8800 if (ssh->cs_mac_ctx)
8801 ssh->csmac->free_context(ssh->cs_mac_ctx);
8802 if (ssh->sc_mac_ctx)
8803 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 8804 if (ssh->cs_comp_ctx) {
8805 if (ssh->cscomp)
8806 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
8807 else
8808 zlib_compress_cleanup(ssh->cs_comp_ctx);
8809 }
8810 if (ssh->sc_comp_ctx) {
8811 if (ssh->sccomp)
8812 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
8813 else
8814 zlib_decompress_cleanup(ssh->sc_comp_ctx);
8815 }
fabd1805 8816 if (ssh->kex_ctx)
8817 dh_cleanup(ssh->kex_ctx);
8818 sfree(ssh->savedhost);
8819
590f6a5f 8820 while (ssh->queuelen-- > 0)
8821 ssh_free_packet(ssh->queue[ssh->queuelen]);
8822 sfree(ssh->queue);
8823
06fadff5 8824 while (ssh->qhead) {
8825 struct queued_handler *qh = ssh->qhead;
8826 ssh->qhead = qh->next;
8827 sfree(ssh->qhead);
8828 }
8829 ssh->qhead = ssh->qtail = NULL;
8830
fabd1805 8831 if (ssh->channels) {
8832 while ((c = delpos234(ssh->channels, 0)) != NULL) {
8833 switch (c->type) {
8834 case CHAN_X11:
8835 if (c->u.x11.s != NULL)
8836 x11_close(c->u.x11.s);
8837 break;
8838 case CHAN_SOCKDATA:
8839 if (c->u.pfd.s != NULL)
8840 pfd_close(c->u.pfd.s);
8841 break;
8842 }
8843 sfree(c);
8844 }
8845 freetree234(ssh->channels);
cdb52705 8846 ssh->channels = NULL;
fabd1805 8847 }
8848
8849 if (ssh->rportfwds) {
8850 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8851 sfree(pf);
8852 freetree234(ssh->rportfwds);
cdb52705 8853 ssh->rportfwds = NULL;
fabd1805 8854 }
8855 sfree(ssh->deferred_send_data);
8856 if (ssh->x11auth)
8857 x11_free_auth(ssh->x11auth);
8858 sfree(ssh->do_ssh_init_state);
8859 sfree(ssh->do_ssh1_login_state);
8860 sfree(ssh->do_ssh2_transport_state);
8861 sfree(ssh->do_ssh2_authconn_state);
4320baf7 8862 sfree(ssh->v_c);
8863 sfree(ssh->v_s);
679539d7 8864 if (ssh->crcda_ctx) {
8865 crcda_free_context(ssh->crcda_ctx);
8866 ssh->crcda_ctx = NULL;
8867 }
fabd1805 8868 if (ssh->s)
ac934965 8869 ssh_do_close(ssh, TRUE);
9442dd57 8870 expire_timer_context(ssh);
39934deb 8871 if (ssh->pinger)
8872 pinger_free(ssh->pinger);
3d9449a1 8873 bufchain_clear(&ssh->queued_incoming_data);
ee50e8b6 8874 sfree(ssh);
5d17ccfc 8875
8876 random_unref();
fabd1805 8877}
8878
374330e2 8879/*
86916870 8880 * Reconfigure the SSH backend.
86916870 8881 */
8882static void ssh_reconfig(void *handle, Config *cfg)
8883{
8884 Ssh ssh = (Ssh) handle;
e13bba36 8885 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 8886 unsigned long old_max_data_size;
8887
39934deb 8888 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
3b6606c7 8889 if (ssh->portfwds)
8890 ssh_setup_portfwd(ssh, cfg);
e6c1536e 8891
8892 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8893 cfg->ssh_rekey_time != 0) {
8894 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8895 long now = GETTICKCOUNT();
8896
8897 if (new_next - now < 0) {
f382c87d 8898 rekeying = "timeout shortened";
e6c1536e 8899 } else {
8900 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8901 }
8902 }
8903
8904 old_max_data_size = ssh->max_data_size;
8905 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8906 if (old_max_data_size != ssh->max_data_size &&
8907 ssh->max_data_size != 0) {
8908 if (ssh->outgoing_data_size > ssh->max_data_size ||
8909 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 8910 rekeying = "data limit lowered";
e6c1536e 8911 }
8912
e13bba36 8913 if (ssh->cfg.compression != cfg->compression) {
f382c87d 8914 rekeying = "compression setting changed";
e13bba36 8915 rekey_mandatory = TRUE;
8916 }
8917
8918 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8919 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8920 sizeof(ssh->cfg.ssh_cipherlist))) {
f382c87d 8921 rekeying = "cipher settings changed";
e13bba36 8922 rekey_mandatory = TRUE;
e6c1536e 8923 }
8924
86916870 8925 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 8926
8927 if (rekeying) {
8928 if (!ssh->kex_in_progress) {
8929 do_ssh2_transport(ssh, rekeying, -1, NULL);
8930 } else if (rekey_mandatory) {
8931 ssh->deferred_rekey_reason = rekeying;
8932 }
8933 }
86916870 8934}
8935
8936/*
86dc445a 8937 * Called to send data down the SSH connection.
374330e2 8938 */
51470298 8939static int ssh_send(void *handle, char *buf, int len)
32874aea 8940{
51470298 8941 Ssh ssh = (Ssh) handle;
8942
8943 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 8944 return 0;
374330e2 8945
d8baa528 8946 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 8947
51470298 8948 return ssh_sendbuffer(ssh);
5471d09a 8949}
8950
8951/*
8952 * Called to query the current amount of buffered stdin data.
8953 */
51470298 8954static int ssh_sendbuffer(void *handle)
5471d09a 8955{
51470298 8956 Ssh ssh = (Ssh) handle;
5471d09a 8957 int override_value;
8958
51470298 8959 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 8960 return 0;
8961
8962 /*
8963 * If the SSH socket itself has backed up, add the total backup
8964 * size on that to any individual buffer on the stdin channel.
8965 */
8966 override_value = 0;
51470298 8967 if (ssh->throttled_all)
8968 override_value = ssh->overall_bufsize;
5471d09a 8969
51470298 8970 if (ssh->version == 1) {
5471d09a 8971 return override_value;
51470298 8972 } else if (ssh->version == 2) {
8973 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 8974 return override_value;
8975 else
51470298 8976 return (override_value +
8977 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 8978 }
8979
8980 return 0;
374330e2 8981}
8982
8983/*
6e48c3fe 8984 * Called to set the size of the window from SSH's POV.
374330e2 8985 */
51470298 8986static void ssh_size(void *handle, int width, int height)
32874aea 8987{
51470298 8988 Ssh ssh = (Ssh) handle;
ff3187f6 8989 struct Packet *pktout;
51470298 8990
8991 ssh->term_width = width;
8992 ssh->term_height = height;
f278d6f8 8993
51470298 8994 switch (ssh->state) {
374330e2 8995 case SSH_STATE_BEFORE_SIZE:
3687d221 8996 case SSH_STATE_PREPACKET:
21248260 8997 case SSH_STATE_CLOSED:
374330e2 8998 break; /* do nothing */
8999 case SSH_STATE_INTERMED:
51470298 9000 ssh->size_needed = TRUE; /* buffer for later */
374330e2 9001 break;
9002 case SSH_STATE_SESSION:
86916870 9003 if (!ssh->cfg.nopty) {
51470298 9004 if (ssh->version == 1) {
9005 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
9006 PKT_INT, ssh->term_height,
9007 PKT_INT, ssh->term_width,
32874aea 9008 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 9009 } else if (ssh->mainchan) {
ff3187f6 9010 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9011 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9012 ssh2_pkt_addstring(pktout, "window-change");
9013 ssh2_pkt_addbool(pktout, 0);
9014 ssh2_pkt_adduint32(pktout, ssh->term_width);
9015 ssh2_pkt_adduint32(pktout, ssh->term_height);
9016 ssh2_pkt_adduint32(pktout, 0);
9017 ssh2_pkt_adduint32(pktout, 0);
9018 ssh2_pkt_send(ssh, pktout);
32874aea 9019 }
9020 }
9021 break;
374330e2 9022 }
9023}
9024
9025/*
125105d1 9026 * Return a list of the special codes that make sense in this
9027 * protocol.
9028 */
9029static const struct telnet_special *ssh_get_specials(void *handle)
9030{
786ba75e 9031 static const struct telnet_special ssh1_ignore_special[] = {
9032 {"IGNORE message", TS_NOP}
9033 };
9034 static const struct telnet_special ssh2_transport_specials[] = {
62638676 9035 {"IGNORE message", TS_NOP},
9442dd57 9036 {"Repeat key exchange", TS_REKEY},
62638676 9037 };
9038 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 9039 {NULL, TS_SEP},
9040 {"Break", TS_BRK},
786ba75e 9041 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 9042 * They include all the ISO C signals, but are a subset of the POSIX
9043 * required signals. */
9044 {"SIGINT (Interrupt)", TS_SIGINT},
9045 {"SIGTERM (Terminate)", TS_SIGTERM},
9046 {"SIGKILL (Kill)", TS_SIGKILL},
9047 {"SIGQUIT (Quit)", TS_SIGQUIT},
9048 {"SIGHUP (Hangup)", TS_SIGHUP},
9049 {"More signals", TS_SUBMENU},
9050 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
9051 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
9052 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
9053 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
9054 {NULL, TS_EXITMENU}
62638676 9055 };
9056 static const struct telnet_special specials_end[] = {
6f2d0cde 9057 {NULL, TS_EXITMENU}
62638676 9058 };
786ba75e 9059 /* XXX review this length for any changes: */
9060 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 9061 lenof(ssh2_session_specials) +
9062 lenof(specials_end)];
125105d1 9063 Ssh ssh = (Ssh) handle;
62638676 9064 int i = 0;
9065#define ADD_SPECIALS(name) \
9066 do { \
9067 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9068 memcpy(&ssh_specials[i], name, sizeof name); \
9069 i += lenof(name); \
9070 } while(0)
125105d1 9071
9072 if (ssh->version == 1) {
62638676 9073 /* Don't bother offering IGNORE if we've decided the remote
9074 * won't cope with it, since we wouldn't bother sending it if
9075 * asked anyway. */
9076 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 9077 ADD_SPECIALS(ssh1_ignore_special);
125105d1 9078 } else if (ssh->version == 2) {
786ba75e 9079 ADD_SPECIALS(ssh2_transport_specials);
62638676 9080 if (ssh->mainchan)
9081 ADD_SPECIALS(ssh2_session_specials);
9082 } /* else we're not ready yet */
9083
9084 if (i) {
9085 ADD_SPECIALS(specials_end);
9086 return ssh_specials;
9087 } else {
125105d1 9088 return NULL;
62638676 9089 }
9090#undef ADD_SPECIALS
125105d1 9091}
9092
9093/*
86dc445a 9094 * Send special codes. TS_EOF is useful for `plink', so you
6abbf9e3 9095 * can send an EOF and collect resulting output (e.g. `plink
9096 * hostname sort').
374330e2 9097 */
51470298 9098static void ssh_special(void *handle, Telnet_Special code)
32874aea 9099{
51470298 9100 Ssh ssh = (Ssh) handle;
ff3187f6 9101 struct Packet *pktout;
51470298 9102
6abbf9e3 9103 if (code == TS_EOF) {
51470298 9104 if (ssh->state != SSH_STATE_SESSION) {
32874aea 9105 /*
9106 * Buffer the EOF in case we are pre-SESSION, so we can
9107 * send it as soon as we reach SESSION.
9108 */
9109 if (code == TS_EOF)
51470298 9110 ssh->eof_needed = TRUE;
32874aea 9111 return;
9112 }
51470298 9113 if (ssh->version == 1) {
9114 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 9115 } else if (ssh->mainchan) {
ff3187f6 9116 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
9117 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9118 ssh2_pkt_send(ssh, pktout);
00a0b113 9119 ssh->send_ok = 0; /* now stop trying to read from stdin */
32874aea 9120 }
9121 logevent("Sent EOF message");
125105d1 9122 } else if (code == TS_PING || code == TS_NOP) {
51470298 9123 if (ssh->state == SSH_STATE_CLOSED
9124 || ssh->state == SSH_STATE_PREPACKET) return;
9125 if (ssh->version == 1) {
9126 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9127 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 9128 } else {
ff3187f6 9129 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
9130 ssh2_pkt_addstring_start(pktout);
590f6a5f 9131 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 9132 }
9442dd57 9133 } else if (code == TS_REKEY) {
9134 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 9135 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 9136 }
125105d1 9137 } else if (code == TS_BRK) {
9138 if (ssh->state == SSH_STATE_CLOSED
9139 || ssh->state == SSH_STATE_PREPACKET) return;
9140 if (ssh->version == 1) {
2e85c969 9141 logevent("Unable to send BREAK signal in SSH-1");
0ed48730 9142 } else if (ssh->mainchan) {
ff3187f6 9143 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9144 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9145 ssh2_pkt_addstring(pktout, "break");
9146 ssh2_pkt_addbool(pktout, 0);
9147 ssh2_pkt_adduint32(pktout, 0); /* default break length */
9148 ssh2_pkt_send(ssh, pktout);
125105d1 9149 }
6abbf9e3 9150 } else {
6f2d0cde 9151 /* Is is a POSIX signal? */
9152 char *signame = NULL;
9153 if (code == TS_SIGABRT) signame = "ABRT";
9154 if (code == TS_SIGALRM) signame = "ALRM";
9155 if (code == TS_SIGFPE) signame = "FPE";
9156 if (code == TS_SIGHUP) signame = "HUP";
9157 if (code == TS_SIGILL) signame = "ILL";
9158 if (code == TS_SIGINT) signame = "INT";
9159 if (code == TS_SIGKILL) signame = "KILL";
9160 if (code == TS_SIGPIPE) signame = "PIPE";
9161 if (code == TS_SIGQUIT) signame = "QUIT";
9162 if (code == TS_SIGSEGV) signame = "SEGV";
9163 if (code == TS_SIGTERM) signame = "TERM";
9164 if (code == TS_SIGUSR1) signame = "USR1";
9165 if (code == TS_SIGUSR2) signame = "USR2";
9166 /* The SSH-2 protocol does in principle support arbitrary named
9167 * signals, including signame@domain, but we don't support those. */
9168 if (signame) {
9169 /* It's a signal. */
9170 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 9171 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9172 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9173 ssh2_pkt_addstring(pktout, "signal");
9174 ssh2_pkt_addbool(pktout, 0);
9175 ssh2_pkt_addstring(pktout, signame);
9176 ssh2_pkt_send(ssh, pktout);
6f2d0cde 9177 logeventf(ssh, "Sent signal SIG%s", signame);
9178 }
9179 } else {
9180 /* Never heard of it. Do nothing */
9181 }
6abbf9e3 9182 }
374330e2 9183}
9184
51470298 9185void *new_sock_channel(void *handle, Socket s)
d74d141c 9186{
51470298 9187 Ssh ssh = (Ssh) handle;
d74d141c 9188 struct ssh_channel *c;
3d88e64d 9189 c = snew(struct ssh_channel);
51470298 9190 c->ssh = ssh;
d74d141c 9191
9192 if (c) {
64d6ff88 9193 c->halfopen = TRUE;
51470298 9194 c->localid = alloc_channel_id(ssh);
d74d141c 9195 c->closes = 0;
bc240b21 9196 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 9197 c->u.pfd.s = s;
013dd8c0 9198 bufchain_init(&c->v.v2.outbuffer);
51470298 9199 add234(ssh->channels, c);
d74d141c 9200 }
9201 return c;
9202}
9203
5471d09a 9204/*
9205 * This is called when stdout/stderr (the entity to which
9206 * from_backend sends data) manages to clear some backlog.
9207 */
ae9ae89f 9208static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 9209{
51470298 9210 Ssh ssh = (Ssh) handle;
9211 if (ssh->version == 1) {
9212 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
9213 ssh->v1_stdout_throttling = 0;
9214 ssh1_throttle(ssh, -1);
5471d09a 9215 }
9216 } else {
ab87bf1d 9217 if (ssh->mainchan)
9218 ssh2_set_window(ssh->mainchan,
9219 ssh->mainchan->v.v2.locmaxwin - bufsize);
5471d09a 9220 }
9221}
9222
6b78788a 9223void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 9224{
9225 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 9226 Ssh ssh = c->ssh;
ff3187f6 9227 struct Packet *pktout;
d74d141c 9228
57356d63 9229 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 9230
51470298 9231 if (ssh->version == 1) {
9232 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 9233 PKT_INT, c->localid,
9234 PKT_STR, hostname,
9235 PKT_INT, port,
31fb1866 9236 /* PKT_STR, <org:orgport>, */
bc240b21 9237 PKT_END);
9238 } else {
ff3187f6 9239 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
9240 ssh2_pkt_addstring(pktout, "direct-tcpip");
9241 ssh2_pkt_adduint32(pktout, c->localid);
9b53e9b8 9242 c->v.v2.locwindow = c->v.v2.locmaxwin = OUR_V2_WINSIZE;
0e443c99 9243 c->v.v2.remlocwin = OUR_V2_WINSIZE;
9244 c->v.v2.winadj_head = c->v.v2.winadj_head = NULL;
9245 c->v.v2.throttle_state = UNTHROTTLED;
ff3187f6 9246 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 9247 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 9248 ssh2_pkt_addstring(pktout, hostname);
9249 ssh2_pkt_adduint32(pktout, port);
bc240b21 9250 /*
9251 * We make up values for the originator data; partly it's
9252 * too much hassle to keep track, and partly I'm not
9253 * convinced the server should be told details like that
9254 * about my local network configuration.
1f182589 9255 * The "originator IP address" is syntactically a numeric
9256 * IP address, and some servers (e.g., Tectia) get upset
9257 * if it doesn't match this syntax.
bc240b21 9258 */
1f182589 9259 ssh2_pkt_addstring(pktout, "0.0.0.0");
ff3187f6 9260 ssh2_pkt_adduint32(pktout, 0);
9261 ssh2_pkt_send(ssh, pktout);
bc240b21 9262 }
d74d141c 9263}
9264
6226c939 9265static int ssh_connected(void *handle)
32874aea 9266{
51470298 9267 Ssh ssh = (Ssh) handle;
6226c939 9268 return ssh->s != NULL;
32874aea 9269}
8ccc75b0 9270
51470298 9271static int ssh_sendok(void *handle)
32874aea 9272{
51470298 9273 Ssh ssh = (Ssh) handle;
9274 return ssh->send_ok;
32874aea 9275}
fb09bf1c 9276
51470298 9277static int ssh_ldisc(void *handle, int option)
32874aea 9278{
51470298 9279 Ssh ssh = (Ssh) handle;
32874aea 9280 if (option == LD_ECHO)
51470298 9281 return ssh->echoing;
32874aea 9282 if (option == LD_EDIT)
51470298 9283 return ssh->editing;
0965bee0 9284 return FALSE;
9285}
9286
b9d7bcad 9287static void ssh_provide_ldisc(void *handle, void *ldisc)
9288{
9289 Ssh ssh = (Ssh) handle;
9290 ssh->ldisc = ldisc;
9291}
9292
a8327734 9293static void ssh_provide_logctx(void *handle, void *logctx)
9294{
9295 Ssh ssh = (Ssh) handle;
9296 ssh->logctx = logctx;
9297}
9298
51470298 9299static int ssh_return_exitcode(void *handle)
9300{
9301 Ssh ssh = (Ssh) handle;
3bb2f322 9302 if (ssh->s != NULL)
9303 return -1;
9304 else
3c112d53 9305 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
51470298 9306}
9307
9308/*
f89c3294 9309 * cfg_info for SSH is the currently running version of the
9310 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
9311 */
9312static int ssh_cfg_info(void *handle)
9313{
9314 Ssh ssh = (Ssh) handle;
9315 return ssh->version;
9316}
9317
9318/*
51470298 9319 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
9320 * that fails. This variable is the means by which scp.c can reach
9321 * into the SSH code and find out which one it got.
9322 */
9323extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 9324{
51470298 9325 Ssh ssh = (Ssh) handle;
9326 return ssh->fallback_cmd;
d8d6c7e5 9327}
9328
374330e2 9329Backend ssh_backend = {
9330 ssh_init,
fabd1805 9331 ssh_free,
86916870 9332 ssh_reconfig,
374330e2 9333 ssh_send,
5471d09a 9334 ssh_sendbuffer,
374330e2 9335 ssh_size,
4017be6d 9336 ssh_special,
125105d1 9337 ssh_get_specials,
6226c939 9338 ssh_connected,
d8d6c7e5 9339 ssh_return_exitcode,
97db3be4 9340 ssh_sendok,
0965bee0 9341 ssh_ldisc,
b9d7bcad 9342 ssh_provide_ldisc,
a8327734 9343 ssh_provide_logctx,
5471d09a 9344 ssh_unthrottle,
f89c3294 9345 ssh_cfg_info,
9e164d82 9346 "ssh",
9347 PROT_SSH,
97db3be4 9348 22
bc240b21 9349};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator