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 */
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 */
69 #define SSH1_AUTH_TIS 5 /* 0x5 */
70 #define SSH1_AUTH_CCARD 16 /* 0x10 */
72 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
73 /* Mask for protoflags we will echo back to server if seen */
74 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
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 */
90 #define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */
91 #define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */
92 #define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */
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 */
99 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
100 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
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 */
117 * Packet type contexts, so that ssh2_pkt_type can correctly decode
118 * the ambiguous type numbers back into the correct type strings.
128 SSH2_PKTCTX_PUBLICKEY,
129 SSH2_PKTCTX_PASSWORD,
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 */
149 static const char *const ssh2_disconnect_reasons[] = {
151 "host not allowed to connect",
153 "key exchange failed",
154 "host authentication failed",
157 "service not available",
158 "protocol version not supported",
159 "host key not verifiable",
162 "too many connections",
163 "auth cancelled by user",
164 "no more auth methods available",
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 */
173 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
176 * Various remote-bug flags.
178 #define BUG_CHOKES_ON_SSH1_IGNORE 1
179 #define BUG_SSH2_HMAC 2
180 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
181 #define BUG_CHOKES_ON_RSA 8
182 #define BUG_SSH2_RSA_PADDING 16
183 #define BUG_SSH2_DERIVEKEY 32
184 #define BUG_SSH2_REKEY 64
185 #define BUG_SSH2_PK_SESSIONID 128
188 * Codes for terminal modes.
189 * Most of these are the same in SSH-1 and SSH-2.
190 * This list is derived from RFC 4254 and
193 static const struct {
194 const char* const mode;
196 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
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 }
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
262 /* Helper functions for parsing tty-related config. */
263 static unsigned int ssh_tty_parse_specchar(char *s)
268 ret = ctrlparse(s, &next);
269 if (!next) ret = s[0];
271 ret = 255; /* special value meaning "don't set" */
275 static unsigned int ssh_tty_parse_boolean(char *s)
277 if (stricmp(s, "yes") == 0 ||
278 stricmp(s, "on") == 0 ||
279 stricmp(s, "true") == 0 ||
280 stricmp(s, "+") == 0)
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 */
288 return (atoi(s) != 0);
291 #define translate(x) if (type == x) return #x
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
294 static char *ssh1_pkt_type(int type)
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);
339 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
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);
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);
358 translate(SSH2_MSG_USERAUTH_REQUEST);
359 translate(SSH2_MSG_USERAUTH_FAILURE);
360 translate(SSH2_MSG_USERAUTH_SUCCESS);
361 translate(SSH2_MSG_USERAUTH_BANNER);
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);
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);
385 /* Enumeration values for fields in SSH-1 packets */
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
394 * Coroutine mechanics for the sillier bits of the code. If these
395 * macros look impenetrable to you, you might find it helpful to
398 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
400 * which explains the theory behind these macros.
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:
407 * - right-click ssh.c in the FileView
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'.
413 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
416 if (!ssh->t) ssh->t = snew(struct t); \
418 #define crFinish(z) } *crLine = 0; return (z); }
419 #define crFinishV } *crLine = 0; return; }
420 #define crReturn(z) \
422 *crLine =__LINE__; return (z); case __LINE__:;\
426 *crLine=__LINE__; return; case __LINE__:;\
428 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
429 #define crStopV do{ *crLine = 0; return; }while(0)
430 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
431 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
433 typedef struct ssh_tag *Ssh;
436 static struct Packet *ssh1_pkt_init(int pkt_type);
437 static struct Packet *ssh2_pkt_init(int pkt_type);
438 static void ssh_pkt_ensure(struct Packet *, int length);
439 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
440 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
441 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
442 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
443 static void ssh_pkt_addstring_start(struct Packet *);
444 static void ssh_pkt_addstring_str(struct Packet *, char *data);
445 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
446 static void ssh_pkt_addstring(struct Packet *, char *data);
447 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
448 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
449 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
450 static int ssh2_pkt_construct(Ssh, struct Packet *);
451 static void ssh2_pkt_send(Ssh, struct Packet *);
452 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
453 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
454 struct Packet *pktin);
455 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
456 struct Packet *pktin);
459 * Buffer management constants. There are several of these for
460 * various different purposes:
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
464 * connection (in SSH-1 only). Throttling the whole connection is
465 * pretty drastic so we set this high in the hope it won't
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
471 * thankfully unlikely in SSH-2 since the window mechanism should
472 * ensure that the server never has any need to throttle its end
473 * of the connection), so we set this high as well.
475 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
478 * - OUR_V2_BIGWIN is the window size we advertise for the only
479 * channel in a simple connection. It must be <= INT_MAX.
482 #define SSH1_BUFFER_LIMIT 32768
483 #define SSH_MAX_BACKLOG 32768
484 #define OUR_V2_WINSIZE 16384
485 #define OUR_V2_BIGWIN 0x7fffffff
486 #define OUR_V2_MAXPKT 0x4000UL
488 /* Maximum length of passwords/passphrases (arbitrary) */
489 #define SSH_MAX_PASSWORD_LEN 100
491 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
493 const static struct ssh_mac *macs[] = {
494 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
496 const static struct ssh_mac *buggymacs[] = {
497 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
500 static void *ssh_comp_none_init(void)
504 static void ssh_comp_none_cleanup(void *handle)
507 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
508 unsigned char **outblock, int *outlen)
512 static int ssh_comp_none_disable(void *handle)
516 const static struct ssh_compress ssh_comp_none = {
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
522 extern const struct ssh_compress ssh_zlib;
523 const static struct ssh_compress *compressions[] = {
524 &ssh_zlib, &ssh_comp_none
527 enum { /* channel types */
532 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
536 * 2-3-4 tree storing channels.
539 Ssh ssh; /* pointer back to main context */
540 unsigned remoteid, localid;
542 /* True if we opened this channel but server hasn't confirmed. */
545 * In SSH-1, this value contains four bits:
547 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
548 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
549 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
550 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
552 * A channel is completely finished with when all four bits are set.
556 struct ssh1_data_channel {
559 struct ssh2_data_channel {
561 unsigned remwindow, remmaxpkt;
562 /* locwindow is signed so we can cope with excess data. */
563 int locwindow, locmaxwin;
567 struct ssh_agent_channel {
568 unsigned char *message;
569 unsigned char msglen[4];
570 unsigned lensofar, totallen;
572 struct ssh_x11_channel {
575 struct ssh_pfd_channel {
582 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
583 * use this structure in different ways, reflecting SSH-2's
584 * altogether saner approach to port forwarding.
586 * In SSH-1, you arrange a remote forwarding by sending the server
587 * the remote port number, and the local destination host:port.
588 * When a connection comes in, the server sends you back that
589 * host:port pair, and you connect to it. This is a ready-made
590 * security hole if you're not on the ball: a malicious server
591 * could send you back _any_ host:port pair, so if you trustingly
592 * connect to the address it gives you then you've just opened the
593 * entire inside of your corporate network just by connecting
594 * through it to a dodgy SSH server. Hence, we must store a list of
595 * host:port pairs we _are_ trying to forward to, and reject a
596 * connection request from the server if it's not in the list.
598 * In SSH-2, each side of the connection minds its own business and
599 * doesn't send unnecessary information to the other. You arrange a
600 * remote forwarding by sending the server just the remote port
601 * number. When a connection comes in, the server tells you which
602 * of its ports was connected to; and _you_ have to remember what
603 * local host:port pair went with that port number.
605 * Hence, in SSH-1 this structure is indexed by destination
606 * host:port pair, whereas in SSH-2 it is indexed by source port.
608 struct ssh_portfwd; /* forward declaration */
610 struct ssh_rportfwd {
611 unsigned sport, dport;
614 struct ssh_portfwd *pfrec;
616 #define free_rportfwd(pf) ( \
617 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
620 * Separately to the rportfwd tree (which is for looking up port
621 * open requests from the server), a tree of _these_ structures is
622 * used to keep track of all the currently open port forwardings,
623 * so that we can reconfigure in mid-session if the user requests
627 enum { DESTROY, KEEP, CREATE } status;
629 unsigned sport, dport;
632 struct ssh_rportfwd *remote;
636 #define free_portfwd(pf) ( \
637 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
638 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
641 long length; /* length of `data' actually used */
642 long forcepad; /* SSH-2: force padding to at least this length */
643 int type; /* only used for incoming packets */
644 unsigned long sequence; /* SSH-2 incoming sequence number */
645 unsigned char *data; /* allocated storage */
646 unsigned char *body; /* offset of payload within `data' */
647 long savedpos; /* temporary index into `data' (for strings) */
648 long maxlen; /* amount of storage allocated for `data' */
649 long encrypted_len; /* for SSH-2 total-size counting */
652 * State associated with packet logging
656 struct logblank_t *blanks;
659 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
660 struct Packet *pktin);
661 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
662 struct Packet *pktin);
663 static void ssh1_protocol_setup(Ssh ssh);
664 static void ssh2_protocol_setup(Ssh ssh);
665 static void ssh_size(void *handle, int width, int height);
666 static void ssh_special(void *handle, Telnet_Special);
667 static int ssh2_try_send(struct ssh_channel *c);
668 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
669 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
670 static void ssh2_set_window(struct ssh_channel *c, int newwin);
671 static int ssh_sendbuffer(void *handle);
672 static int ssh_do_close(Ssh ssh, int notify_exit);
673 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
674 static int ssh2_pkt_getbool(struct Packet *pkt);
675 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
676 static void ssh2_timer(void *ctx, long now);
677 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
678 struct Packet *pktin);
680 struct rdpkt1_state_tag {
681 long len, pad, biglen, to_read;
682 unsigned long realcrc, gotcrc;
686 struct Packet *pktin;
689 struct rdpkt2_state_tag {
690 long len, pad, payload, packetlen, maclen;
693 unsigned long incoming_sequence;
694 struct Packet *pktin;
697 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
698 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
700 struct queued_handler;
701 struct queued_handler {
703 chandler_fn_t handler;
705 struct queued_handler *next;
709 const struct plug_function_table *fn;
710 /* the above field _must_ be first in the structure */
720 unsigned char session_key[32];
722 int v1_remote_protoflags;
723 int v1_local_protoflags;
724 int agentfwd_enabled;
727 const struct ssh_cipher *cipher;
730 const struct ssh2_cipher *cscipher, *sccipher;
731 void *cs_cipher_ctx, *sc_cipher_ctx;
732 const struct ssh_mac *csmac, *scmac;
733 void *cs_mac_ctx, *sc_mac_ctx;
734 const struct ssh_compress *cscomp, *sccomp;
735 void *cs_comp_ctx, *sc_comp_ctx;
736 const struct ssh_kex *kex;
737 const struct ssh_signkey *hostkey;
738 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
739 int v2_session_id_len;
745 int echoing, editing;
749 int ospeed, ispeed; /* temporaries */
750 int term_width, term_height;
752 tree234 *channels; /* indexed by local id */
753 struct ssh_channel *mainchan; /* primary session channel */
754 int ncmode; /* is primary channel direct-tcpip? */
759 tree234 *rportfwds, *portfwds;
763 SSH_STATE_BEFORE_SIZE,
769 int size_needed, eof_needed;
771 struct Packet **queue;
772 int queuelen, queuesize;
774 unsigned char *deferred_send_data;
775 int deferred_len, deferred_size;
778 * Gross hack: pscp will try to start SFTP but fall back to
779 * scp1 if that fails. This variable is the means by which
780 * scp.c can reach into the SSH code and find out which one it
785 bufchain banner; /* accumulates banners during do_ssh2_authconn */
793 int v1_throttle_count;
796 int v1_stdout_throttling;
797 unsigned long v2_outgoing_sequence;
799 int ssh1_rdpkt_crstate;
800 int ssh2_rdpkt_crstate;
801 int do_ssh_init_crstate;
802 int ssh_gotdata_crstate;
803 int do_ssh1_login_crstate;
804 int do_ssh1_connection_crstate;
805 int do_ssh2_transport_crstate;
806 int do_ssh2_authconn_crstate;
808 void *do_ssh_init_state;
809 void *do_ssh1_login_state;
810 void *do_ssh2_transport_state;
811 void *do_ssh2_authconn_state;
813 struct rdpkt1_state_tag rdpkt1_state;
814 struct rdpkt2_state_tag rdpkt2_state;
816 /* SSH-1 and SSH-2 use this for different things, but both use it */
817 int protocol_initial_phase_done;
819 void (*protocol) (Ssh ssh, void *vin, int inlen,
821 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
824 * We maintain a full _copy_ of a Config structure here, not
825 * merely a pointer to it. That way, when we're passed a new
826 * one for reconfiguration, we can check the differences and
827 * potentially reconfigure port forwardings etc in mid-session.
832 * Used to transfer data back from async callbacks.
834 void *agent_response;
835 int agent_response_len;
839 * The SSH connection can be set as `frozen', meaning we are
840 * not currently accepting incoming data from the network. This
841 * is slightly more serious than setting the _socket_ as
842 * frozen, because we may already have had data passed to us
843 * from the network which we need to delay processing until
844 * after the freeze is lifted, so we also need a bufchain to
848 bufchain queued_incoming_data;
851 * Dispatch table for packet types that we may have to deal
854 handler_fn_t packet_dispatch[256];
857 * Queues of one-off handler functions for success/failure
858 * indications from a request.
860 struct queued_handler *qhead, *qtail;
863 * This module deals with sending keepalives.
868 * Track incoming and outgoing data sizes and time, for
871 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
872 unsigned long max_data_size;
874 long next_rekey, last_rekey;
875 char *deferred_rekey_reason; /* points to STATIC string; don't free */
878 #define logevent(s) logevent(ssh->frontend, s)
880 /* logevent, only printf-formatted. */
881 static void logeventf(Ssh ssh, const char *fmt, ...)
887 buf = dupvprintf(fmt, ap);
893 #define bombout(msg) \
895 char *text = dupprintf msg; \
896 ssh_do_close(ssh, FALSE); \
898 connection_fatal(ssh->frontend, "%s", text); \
902 /* Functions to leave bits out of the SSH packet log file. */
904 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
906 if (ssh->cfg.logomitpass)
907 pkt->logmode = blanktype;
910 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
912 if (ssh->cfg.logomitdata)
913 pkt->logmode = blanktype;
916 static void end_log_omission(Ssh ssh, struct Packet *pkt)
918 pkt->logmode = PKTLOG_EMIT;
921 /* Helper function for common bits of parsing cfg.ttymodes. */
922 static void parse_ttymodes(Ssh ssh, char *modes,
923 void (*do_mode)(void *data, char *mode, char *val),
927 char *t = strchr(modes, '\t');
928 char *m = snewn(t-modes+1, char);
930 strncpy(m, modes, t-modes);
933 val = get_ttymode(ssh->frontend, m);
937 do_mode(data, m, val);
940 modes += strlen(modes) + 1;
944 static int ssh_channelcmp(void *av, void *bv)
946 struct ssh_channel *a = (struct ssh_channel *) av;
947 struct ssh_channel *b = (struct ssh_channel *) bv;
948 if (a->localid < b->localid)
950 if (a->localid > b->localid)
954 static int ssh_channelfind(void *av, void *bv)
956 unsigned *a = (unsigned *) av;
957 struct ssh_channel *b = (struct ssh_channel *) bv;
965 static int ssh_rportcmp_ssh1(void *av, void *bv)
967 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
968 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
970 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
971 return i < 0 ? -1 : +1;
972 if (a->dport > b->dport)
974 if (a->dport < b->dport)
979 static int ssh_rportcmp_ssh2(void *av, void *bv)
981 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
982 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
984 if (a->sport > b->sport)
986 if (a->sport < b->sport)
992 * Special form of strcmp which can cope with NULL inputs. NULL is
993 * defined to sort before even the empty string.
995 static int nullstrcmp(const char *a, const char *b)
997 if (a == NULL && b == NULL)
1003 return strcmp(a, b);
1006 static int ssh_portcmp(void *av, void *bv)
1008 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1009 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1011 if (a->type > b->type)
1013 if (a->type < b->type)
1015 if (a->addressfamily > b->addressfamily)
1017 if (a->addressfamily < b->addressfamily)
1019 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1020 return i < 0 ? -1 : +1;
1021 if (a->sport > b->sport)
1023 if (a->sport < b->sport)
1025 if (a->type != 'D') {
1026 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1027 return i < 0 ? -1 : +1;
1028 if (a->dport > b->dport)
1030 if (a->dport < b->dport)
1036 static int alloc_channel_id(Ssh ssh)
1038 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1039 unsigned low, high, mid;
1041 struct ssh_channel *c;
1044 * First-fit allocation of channel numbers: always pick the
1045 * lowest unused one. To do this, binary-search using the
1046 * counted B-tree to find the largest channel ID which is in a
1047 * contiguous sequence from the beginning. (Precisely
1048 * everything in that sequence must have ID equal to its tree
1049 * index plus CHANNEL_NUMBER_OFFSET.)
1051 tsize = count234(ssh->channels);
1055 while (high - low > 1) {
1056 mid = (high + low) / 2;
1057 c = index234(ssh->channels, mid);
1058 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1059 low = mid; /* this one is fine */
1061 high = mid; /* this one is past it */
1064 * Now low points to either -1, or the tree index of the
1065 * largest ID in the initial sequence.
1068 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1069 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1071 return low + 1 + CHANNEL_NUMBER_OFFSET;
1074 static void c_write_stderr(int trusted, const char *buf, int len)
1077 for (i = 0; i < len; i++)
1078 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1079 fputc(buf[i], stderr);
1082 static void c_write(Ssh ssh, const char *buf, int len)
1084 if (flags & FLAG_STDERR)
1085 c_write_stderr(1, buf, len);
1087 from_backend(ssh->frontend, 1, buf, len);
1090 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1092 if (flags & FLAG_STDERR)
1093 c_write_stderr(0, buf, len);
1095 from_backend_untrusted(ssh->frontend, buf, len);
1098 static void c_write_str(Ssh ssh, const char *buf)
1100 c_write(ssh, buf, strlen(buf));
1103 static void ssh_free_packet(struct Packet *pkt)
1108 static struct Packet *ssh_new_packet(void)
1110 struct Packet *pkt = snew(struct Packet);
1112 pkt->body = pkt->data = NULL;
1114 pkt->logmode = PKTLOG_EMIT;
1122 * Collect incoming data in the incoming packet buffer.
1123 * Decipher and verify the packet when it is completely read.
1124 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1125 * Update the *data and *datalen variables.
1126 * Return a Packet structure when a packet is completed.
1128 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1130 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1132 crBegin(ssh->ssh1_rdpkt_crstate);
1134 st->pktin = ssh_new_packet();
1136 st->pktin->type = 0;
1137 st->pktin->length = 0;
1139 for (st->i = st->len = 0; st->i < 4; st->i++) {
1140 while ((*datalen) == 0)
1142 st->len = (st->len << 8) + **data;
1143 (*data)++, (*datalen)--;
1146 st->pad = 8 - (st->len % 8);
1147 st->biglen = st->len + st->pad;
1148 st->pktin->length = st->len - 5;
1150 if (st->biglen < 0) {
1151 bombout(("Extremely large packet length from server suggests"
1152 " data stream corruption"));
1153 ssh_free_packet(st->pktin);
1157 st->pktin->maxlen = st->biglen;
1158 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1160 st->to_read = st->biglen;
1161 st->p = st->pktin->data;
1162 while (st->to_read > 0) {
1163 st->chunk = st->to_read;
1164 while ((*datalen) == 0)
1166 if (st->chunk > (*datalen))
1167 st->chunk = (*datalen);
1168 memcpy(st->p, *data, st->chunk);
1170 *datalen -= st->chunk;
1172 st->to_read -= st->chunk;
1175 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1176 st->biglen, NULL)) {
1177 bombout(("Network attack (CRC compensation) detected!"));
1178 ssh_free_packet(st->pktin);
1183 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1185 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1186 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1187 if (st->gotcrc != st->realcrc) {
1188 bombout(("Incorrect CRC received on packet"));
1189 ssh_free_packet(st->pktin);
1193 st->pktin->body = st->pktin->data + st->pad + 1;
1194 st->pktin->savedpos = 0;
1196 if (ssh->v1_compressing) {
1197 unsigned char *decompblk;
1199 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1200 st->pktin->body - 1, st->pktin->length + 1,
1201 &decompblk, &decomplen)) {
1202 bombout(("Zlib decompression encountered invalid data"));
1203 ssh_free_packet(st->pktin);
1207 if (st->pktin->maxlen < st->pad + decomplen) {
1208 st->pktin->maxlen = st->pad + decomplen;
1209 st->pktin->data = sresize(st->pktin->data,
1210 st->pktin->maxlen + APIEXTRA,
1212 st->pktin->body = st->pktin->data + st->pad + 1;
1215 memcpy(st->pktin->body - 1, decompblk, decomplen);
1217 st->pktin->length = decomplen - 1;
1220 st->pktin->type = st->pktin->body[-1];
1223 * Log incoming packet, possibly omitting sensitive fields.
1227 struct logblank_t blank;
1228 if (ssh->cfg.logomitdata) {
1229 int do_blank = FALSE, blank_prefix = 0;
1230 /* "Session data" packets - omit the data field */
1231 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1232 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1233 do_blank = TRUE; blank_prefix = 4;
1234 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1235 do_blank = TRUE; blank_prefix = 8;
1238 blank.offset = blank_prefix;
1239 blank.len = st->pktin->length;
1240 blank.type = PKTLOG_OMIT;
1244 log_packet(ssh->logctx,
1245 PKT_INCOMING, st->pktin->type,
1246 ssh1_pkt_type(st->pktin->type),
1247 st->pktin->body, st->pktin->length,
1251 crFinish(st->pktin);
1254 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1256 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1258 crBegin(ssh->ssh2_rdpkt_crstate);
1260 st->pktin = ssh_new_packet();
1262 st->pktin->type = 0;
1263 st->pktin->length = 0;
1265 st->cipherblk = ssh->sccipher->blksize;
1268 if (st->cipherblk < 8)
1271 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1274 * Acquire and decrypt the first block of the packet. This will
1275 * contain the length and padding details.
1277 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1278 while ((*datalen) == 0)
1280 st->pktin->data[st->i] = *(*data)++;
1285 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1286 st->pktin->data, st->cipherblk);
1289 * Now get the length and padding figures.
1291 st->len = GET_32BIT(st->pktin->data);
1292 st->pad = st->pktin->data[4];
1295 * _Completely_ silly lengths should be stomped on before they
1296 * do us any more damage.
1298 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1299 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
1300 bombout(("Incoming packet was garbled on decryption"));
1301 ssh_free_packet(st->pktin);
1306 * This enables us to deduce the payload length.
1308 st->payload = st->len - st->pad - 1;
1310 st->pktin->length = st->payload + 5;
1313 * So now we can work out the total packet length.
1315 st->packetlen = st->len + 4;
1316 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1319 * Allocate memory for the rest of the packet.
1321 st->pktin->maxlen = st->packetlen + st->maclen;
1322 st->pktin->data = sresize(st->pktin->data,
1323 st->pktin->maxlen + APIEXTRA,
1327 * Read and decrypt the remainder of the packet.
1329 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1331 while ((*datalen) == 0)
1333 st->pktin->data[st->i] = *(*data)++;
1336 /* Decrypt everything _except_ the MAC. */
1338 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1339 st->pktin->data + st->cipherblk,
1340 st->packetlen - st->cipherblk);
1342 st->pktin->encrypted_len = st->packetlen;
1348 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1349 st->incoming_sequence)) {
1350 bombout(("Incorrect MAC received on packet"));
1351 ssh_free_packet(st->pktin);
1355 st->pktin->sequence = st->incoming_sequence++;
1358 * Decompress packet payload.
1361 unsigned char *newpayload;
1364 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1365 st->pktin->data + 5, st->pktin->length - 5,
1366 &newpayload, &newlen)) {
1367 if (st->pktin->maxlen < newlen + 5) {
1368 st->pktin->maxlen = newlen + 5;
1369 st->pktin->data = sresize(st->pktin->data,
1370 st->pktin->maxlen + APIEXTRA,
1373 st->pktin->length = 5 + newlen;
1374 memcpy(st->pktin->data + 5, newpayload, newlen);
1379 st->pktin->savedpos = 6;
1380 st->pktin->body = st->pktin->data;
1381 st->pktin->type = st->pktin->data[5];
1384 * Log incoming packet, possibly omitting sensitive fields.
1388 struct logblank_t blank;
1389 if (ssh->cfg.logomitdata) {
1390 int do_blank = FALSE, blank_prefix = 0;
1391 /* "Session data" packets - omit the data field */
1392 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1393 do_blank = TRUE; blank_prefix = 8;
1394 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1395 do_blank = TRUE; blank_prefix = 12;
1398 blank.offset = blank_prefix;
1399 blank.len = (st->pktin->length-6) - blank_prefix;
1400 blank.type = PKTLOG_OMIT;
1404 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1405 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1407 st->pktin->data+6, st->pktin->length-6,
1411 crFinish(st->pktin);
1414 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1416 int pad, biglen, i, pktoffs;
1420 * XXX various versions of SC (including 8.8.4) screw up the
1421 * register allocation in this function and use the same register
1422 * (D6) for len and as a temporary, with predictable results. The
1423 * following sledgehammer prevents this.
1430 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1431 ssh1_pkt_type(pkt->data[12]),
1432 pkt->body, pkt->length - (pkt->body - pkt->data),
1433 pkt->nblanks, pkt->blanks);
1434 sfree(pkt->blanks); pkt->blanks = NULL;
1437 if (ssh->v1_compressing) {
1438 unsigned char *compblk;
1440 zlib_compress_block(ssh->cs_comp_ctx,
1441 pkt->data + 12, pkt->length - 12,
1442 &compblk, &complen);
1443 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1444 memcpy(pkt->data + 12, compblk, complen);
1446 pkt->length = complen + 12;
1449 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1451 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1452 pad = 8 - (len % 8);
1454 biglen = len + pad; /* len(padding+type+data+CRC) */
1456 for (i = pktoffs; i < 4+8; i++)
1457 pkt->data[i] = random_byte();
1458 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1459 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1460 PUT_32BIT(pkt->data + pktoffs, len);
1463 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1464 pkt->data + pktoffs + 4, biglen);
1466 if (offset_p) *offset_p = pktoffs;
1467 return biglen + 4; /* len(length+padding+type+data+CRC) */
1470 static int s_write(Ssh ssh, void *data, int len)
1473 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len, 0, NULL);
1474 return sk_write(ssh->s, (char *)data, len);
1477 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1479 int len, backlog, offset;
1480 len = s_wrpkt_prepare(ssh, pkt, &offset);
1481 backlog = s_write(ssh, pkt->data + offset, len);
1482 if (backlog > SSH_MAX_BACKLOG)
1483 ssh_throttle_all(ssh, 1, backlog);
1484 ssh_free_packet(pkt);
1487 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1490 len = s_wrpkt_prepare(ssh, pkt, &offset);
1491 if (ssh->deferred_len + len > ssh->deferred_size) {
1492 ssh->deferred_size = ssh->deferred_len + len + 128;
1493 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1497 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1498 pkt->data + offset, len);
1499 ssh->deferred_len += len;
1500 ssh_free_packet(pkt);
1504 * Construct a SSH-1 packet with the specified contents.
1505 * (This all-at-once interface used to be the only one, but now SSH-1
1506 * packets can also be constructed incrementally.)
1508 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1514 pkt = ssh1_pkt_init(pkttype);
1516 while ((argtype = va_arg(ap, int)) != PKT_END) {
1517 unsigned char *argp, argchar;
1519 unsigned long argint;
1522 /* Actual fields in the packet */
1524 argint = va_arg(ap, int);
1525 ssh_pkt_adduint32(pkt, argint);
1528 argchar = (unsigned char) va_arg(ap, int);
1529 ssh_pkt_addbyte(pkt, argchar);
1532 argp = va_arg(ap, unsigned char *);
1533 arglen = va_arg(ap, int);
1534 ssh_pkt_adddata(pkt, argp, arglen);
1537 sargp = va_arg(ap, char *);
1538 ssh_pkt_addstring(pkt, sargp);
1541 bn = va_arg(ap, Bignum);
1542 ssh1_pkt_addmp(pkt, bn);
1544 /* Tokens for modifications to packet logging */
1546 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1549 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1552 end_log_omission(ssh, pkt);
1560 static void send_packet(Ssh ssh, int pkttype, ...)
1564 va_start(ap, pkttype);
1565 pkt = construct_packet(ssh, pkttype, ap);
1570 static void defer_packet(Ssh ssh, int pkttype, ...)
1574 va_start(ap, pkttype);
1575 pkt = construct_packet(ssh, pkttype, ap);
1577 s_wrpkt_defer(ssh, pkt);
1580 static int ssh_versioncmp(char *a, char *b)
1583 unsigned long av, bv;
1585 av = strtoul(a, &ae, 10);
1586 bv = strtoul(b, &be, 10);
1588 return (av < bv ? -1 : +1);
1593 av = strtoul(ae, &ae, 10);
1594 bv = strtoul(be, &be, 10);
1596 return (av < bv ? -1 : +1);
1601 * Utility routines for putting an SSH-protocol `string' and
1602 * `uint32' into a hash state.
1604 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1606 unsigned char lenblk[4];
1607 PUT_32BIT(lenblk, len);
1608 h->bytes(s, lenblk, 4);
1609 h->bytes(s, str, len);
1612 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1614 unsigned char intblk[4];
1615 PUT_32BIT(intblk, i);
1616 h->bytes(s, intblk, 4);
1620 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1622 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1624 if (pkt->maxlen < length) {
1625 unsigned char *body = pkt->body;
1626 int offset = body ? body - pkt->data : 0;
1627 pkt->maxlen = length + 256;
1628 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1629 if (body) pkt->body = pkt->data + offset;
1632 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1634 if (pkt->logmode != PKTLOG_EMIT) {
1636 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1638 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1639 (pkt->body - pkt->data);
1640 pkt->blanks[pkt->nblanks-1].len = len;
1641 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1644 ssh_pkt_ensure(pkt, pkt->length);
1645 memcpy(pkt->data + pkt->length - len, data, len);
1647 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1649 ssh_pkt_adddata(pkt, &byte, 1);
1651 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1653 ssh_pkt_adddata(pkt, &value, 1);
1655 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1658 PUT_32BIT(x, value);
1659 ssh_pkt_adddata(pkt, x, 4);
1661 static void ssh_pkt_addstring_start(struct Packet *pkt)
1663 ssh_pkt_adduint32(pkt, 0);
1664 pkt->savedpos = pkt->length;
1666 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1668 ssh_pkt_adddata(pkt, data, strlen(data));
1669 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1671 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1673 ssh_pkt_adddata(pkt, data, len);
1674 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1676 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1678 ssh_pkt_addstring_start(pkt);
1679 ssh_pkt_addstring_str(pkt, data);
1681 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1683 int len = ssh1_bignum_length(b);
1684 unsigned char *data = snewn(len, unsigned char);
1685 (void) ssh1_write_bignum(data, b);
1686 ssh_pkt_adddata(pkt, data, len);
1689 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1692 int i, n = (bignum_bitcount(b) + 7) / 8;
1693 p = snewn(n + 1, unsigned char);
1695 for (i = 1; i <= n; i++)
1696 p[i] = bignum_byte(b, n - i);
1698 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1700 memmove(p, p + i, n + 1 - i);
1704 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1708 p = ssh2_mpint_fmt(b, &len);
1709 ssh_pkt_addstring_start(pkt);
1710 ssh_pkt_addstring_data(pkt, (char *)p, len);
1714 static struct Packet *ssh1_pkt_init(int pkt_type)
1716 struct Packet *pkt = ssh_new_packet();
1717 pkt->length = 4 + 8; /* space for length + max padding */
1718 ssh_pkt_addbyte(pkt, pkt_type);
1719 pkt->body = pkt->data + pkt->length;
1723 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1724 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1725 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1726 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1727 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1728 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1729 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1730 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1731 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1733 static struct Packet *ssh2_pkt_init(int pkt_type)
1735 struct Packet *pkt = ssh_new_packet();
1736 pkt->length = 5; /* space for packet length + padding length */
1738 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1739 pkt->body = pkt->data + pkt->length; /* after packet type */
1744 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1745 * put the MAC on it. Final packet, ready to be sent, is stored in
1746 * pkt->data. Total length is returned.
1748 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1750 int cipherblk, maclen, padding, i;
1753 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1754 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1755 pkt->body, pkt->length - (pkt->body - pkt->data),
1756 pkt->nblanks, pkt->blanks);
1757 sfree(pkt->blanks); pkt->blanks = NULL;
1761 * Compress packet payload.
1764 unsigned char *newpayload;
1767 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1769 &newpayload, &newlen)) {
1771 ssh2_pkt_adddata(pkt, newpayload, newlen);
1777 * Add padding. At least four bytes, and must also bring total
1778 * length (minus MAC) up to a multiple of the block size.
1779 * If pkt->forcepad is set, make sure the packet is at least that size
1782 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1783 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1785 if (pkt->length + padding < pkt->forcepad)
1786 padding = pkt->forcepad - pkt->length;
1788 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1789 assert(padding <= 255);
1790 maclen = ssh->csmac ? ssh->csmac->len : 0;
1791 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1792 pkt->data[4] = padding;
1793 for (i = 0; i < padding; i++)
1794 pkt->data[pkt->length + i] = random_byte();
1795 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1797 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1798 pkt->length + padding,
1799 ssh->v2_outgoing_sequence);
1800 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1803 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1804 pkt->data, pkt->length + padding);
1806 pkt->encrypted_len = pkt->length + padding;
1808 /* Ready-to-send packet starts at pkt->data. We return length. */
1809 return pkt->length + padding + maclen;
1813 * Routines called from the main SSH code to send packets. There
1814 * are quite a few of these, because we have two separate
1815 * mechanisms for delaying the sending of packets:
1817 * - In order to send an IGNORE message and a password message in
1818 * a single fixed-length blob, we require the ability to
1819 * concatenate the encrypted forms of those two packets _into_ a
1820 * single blob and then pass it to our <network.h> transport
1821 * layer in one go. Hence, there's a deferment mechanism which
1822 * works after packet encryption.
1824 * - In order to avoid sending any connection-layer messages
1825 * during repeat key exchange, we have to queue up any such
1826 * outgoing messages _before_ they are encrypted (and in
1827 * particular before they're allocated sequence numbers), and
1828 * then send them once we've finished.
1830 * I call these mechanisms `defer' and `queue' respectively, so as
1831 * to distinguish them reasonably easily.
1833 * The functions send_noqueue() and defer_noqueue() free the packet
1834 * structure they are passed. Every outgoing packet goes through
1835 * precisely one of these functions in its life; packets passed to
1836 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1837 * these or get queued, and then when the queue is later emptied
1838 * the packets are all passed to defer_noqueue().
1840 * When using a CBC-mode cipher, it's necessary to ensure that an
1841 * attacker can't provide data to be encrypted using an IV that they
1842 * know. We ensure this by prefixing each packet that might contain
1843 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1844 * mechanism, so in this case send_noqueue() ends up redirecting to
1845 * defer_noqueue(). If you don't like this inefficiency, don't use
1849 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1850 static void ssh_pkt_defersend(Ssh);
1853 * Send an SSH-2 packet immediately, without queuing or deferring.
1855 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1859 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1860 /* We need to send two packets, so use the deferral mechanism. */
1861 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1862 ssh_pkt_defersend(ssh);
1865 len = ssh2_pkt_construct(ssh, pkt);
1866 backlog = s_write(ssh, pkt->data, len);
1867 if (backlog > SSH_MAX_BACKLOG)
1868 ssh_throttle_all(ssh, 1, backlog);
1870 ssh->outgoing_data_size += pkt->encrypted_len;
1871 if (!ssh->kex_in_progress &&
1872 ssh->max_data_size != 0 &&
1873 ssh->outgoing_data_size > ssh->max_data_size)
1874 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1876 ssh_free_packet(pkt);
1880 * Defer an SSH-2 packet.
1882 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
1885 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1886 ssh->deferred_len == 0 && !noignore) {
1888 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1889 * get encrypted with a known IV.
1891 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1892 ssh2_pkt_addstring_start(ipkt);
1893 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1895 len = ssh2_pkt_construct(ssh, pkt);
1896 if (ssh->deferred_len + len > ssh->deferred_size) {
1897 ssh->deferred_size = ssh->deferred_len + len + 128;
1898 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1902 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1903 ssh->deferred_len += len;
1904 ssh->deferred_data_size += pkt->encrypted_len;
1905 ssh_free_packet(pkt);
1909 * Queue an SSH-2 packet.
1911 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1913 assert(ssh->queueing);
1915 if (ssh->queuelen >= ssh->queuesize) {
1916 ssh->queuesize = ssh->queuelen + 32;
1917 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1920 ssh->queue[ssh->queuelen++] = pkt;
1924 * Either queue or send a packet, depending on whether queueing is
1927 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1930 ssh2_pkt_queue(ssh, pkt);
1932 ssh2_pkt_send_noqueue(ssh, pkt);
1936 * Either queue or defer a packet, depending on whether queueing is
1939 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1942 ssh2_pkt_queue(ssh, pkt);
1944 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1948 * Send the whole deferred data block constructed by
1949 * ssh2_pkt_defer() or SSH-1's defer_packet().
1951 * The expected use of the defer mechanism is that you call
1952 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1953 * not currently queueing, this simply sets up deferred_send_data
1954 * and then sends it. If we _are_ currently queueing, the calls to
1955 * ssh2_pkt_defer() put the deferred packets on to the queue
1956 * instead, and therefore ssh_pkt_defersend() has no deferred data
1957 * to send. Hence, there's no need to make it conditional on
1960 static void ssh_pkt_defersend(Ssh ssh)
1963 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
1964 ssh->deferred_len = ssh->deferred_size = 0;
1965 sfree(ssh->deferred_send_data);
1966 ssh->deferred_send_data = NULL;
1967 if (backlog > SSH_MAX_BACKLOG)
1968 ssh_throttle_all(ssh, 1, backlog);
1970 ssh->outgoing_data_size += ssh->deferred_data_size;
1971 if (!ssh->kex_in_progress &&
1972 ssh->max_data_size != 0 &&
1973 ssh->outgoing_data_size > ssh->max_data_size)
1974 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1975 ssh->deferred_data_size = 0;
1979 * Send a packet whose length needs to be disguised (typically
1980 * passwords or keyboard-interactive responses).
1982 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
1988 * The simplest way to do this is to adjust the
1989 * variable-length padding field in the outgoing packet.
1991 * Currently compiled out, because some Cisco SSH servers
1992 * don't like excessively padded packets (bah, why's it
1995 pkt->forcepad = padsize;
1996 ssh2_pkt_send(ssh, pkt);
2001 * If we can't do that, however, an alternative approach is
2002 * to use the pkt_defer mechanism to bundle the packet
2003 * tightly together with an SSH_MSG_IGNORE such that their
2004 * combined length is a constant. So first we construct the
2005 * final form of this packet and defer its sending.
2007 ssh2_pkt_defer(ssh, pkt);
2010 * Now construct an SSH_MSG_IGNORE which includes a string
2011 * that's an exact multiple of the cipher block size. (If
2012 * the cipher is NULL so that the block size is
2013 * unavailable, we don't do this trick at all, because we
2014 * gain nothing by it.)
2016 if (ssh->cscipher) {
2019 stringlen = (256 - ssh->deferred_len);
2020 stringlen += ssh->cscipher->blksize - 1;
2021 stringlen -= (stringlen % ssh->cscipher->blksize);
2024 * Temporarily disable actual compression, so we
2025 * can guarantee to get this string exactly the
2026 * length we want it. The compression-disabling
2027 * routine should return an integer indicating how
2028 * many bytes we should adjust our string length
2032 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2034 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2035 ssh2_pkt_addstring_start(pkt);
2036 for (i = 0; i < stringlen; i++) {
2037 char c = (char) random_byte();
2038 ssh2_pkt_addstring_data(pkt, &c, 1);
2040 ssh2_pkt_defer(ssh, pkt);
2042 ssh_pkt_defersend(ssh);
2047 * Send all queued SSH-2 packets. We send them by means of
2048 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2049 * packets that needed to be lumped together.
2051 static void ssh2_pkt_queuesend(Ssh ssh)
2055 assert(!ssh->queueing);
2057 for (i = 0; i < ssh->queuelen; i++)
2058 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2061 ssh_pkt_defersend(ssh);
2065 void bndebug(char *string, Bignum b)
2069 p = ssh2_mpint_fmt(b, &len);
2070 debug(("%s", string));
2071 for (i = 0; i < len; i++)
2072 debug((" %02x", p[i]));
2078 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2082 p = ssh2_mpint_fmt(b, &len);
2083 hash_string(h, s, p, len);
2088 * Packet decode functions for both SSH-1 and SSH-2.
2090 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2092 unsigned long value;
2093 if (pkt->length - pkt->savedpos < 4)
2094 return 0; /* arrgh, no way to decline (FIXME?) */
2095 value = GET_32BIT(pkt->body + pkt->savedpos);
2099 static int ssh2_pkt_getbool(struct Packet *pkt)
2101 unsigned long value;
2102 if (pkt->length - pkt->savedpos < 1)
2103 return 0; /* arrgh, no way to decline (FIXME?) */
2104 value = pkt->body[pkt->savedpos] != 0;
2108 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2113 if (pkt->length - pkt->savedpos < 4)
2115 len = GET_32BIT(pkt->body + pkt->savedpos);
2120 if (pkt->length - pkt->savedpos < *length)
2122 *p = (char *)(pkt->body + pkt->savedpos);
2123 pkt->savedpos += *length;
2125 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2127 if (pkt->length - pkt->savedpos < length)
2129 pkt->savedpos += length;
2130 return pkt->body + (pkt->savedpos - length);
2132 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2133 unsigned char **keystr)
2137 j = makekey(pkt->body + pkt->savedpos,
2138 pkt->length - pkt->savedpos,
2145 assert(pkt->savedpos < pkt->length);
2149 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2154 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2155 pkt->length - pkt->savedpos, &b);
2163 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2169 ssh_pkt_getstring(pkt, &p, &length);
2174 b = bignum_from_bytes((unsigned char *)p, length);
2179 * Helper function to add an SSH-2 signature blob to a packet.
2180 * Expects to be shown the public key blob as well as the signature
2181 * blob. Normally works just like ssh2_pkt_addstring, but will
2182 * fiddle with the signature packet if necessary for
2183 * BUG_SSH2_RSA_PADDING.
2185 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2186 void *pkblob_v, int pkblob_len,
2187 void *sigblob_v, int sigblob_len)
2189 unsigned char *pkblob = (unsigned char *)pkblob_v;
2190 unsigned char *sigblob = (unsigned char *)sigblob_v;
2192 /* dmemdump(pkblob, pkblob_len); */
2193 /* dmemdump(sigblob, sigblob_len); */
2196 * See if this is in fact an ssh-rsa signature and a buggy
2197 * server; otherwise we can just do this the easy way.
2199 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2200 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2201 int pos, len, siglen;
2204 * Find the byte length of the modulus.
2207 pos = 4+7; /* skip over "ssh-rsa" */
2208 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2209 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2210 pos += 4; /* find modulus itself */
2211 while (len > 0 && pkblob[pos] == 0)
2213 /* debug(("modulus length is %d\n", len)); */
2216 * Now find the signature integer.
2218 pos = 4+7; /* skip over "ssh-rsa" */
2219 siglen = GET_32BIT(sigblob+pos);
2220 /* debug(("signature length is %d\n", siglen)); */
2222 if (len != siglen) {
2223 unsigned char newlen[4];
2224 ssh2_pkt_addstring_start(pkt);
2225 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2226 /* dmemdump(sigblob, pos); */
2227 pos += 4; /* point to start of actual sig */
2228 PUT_32BIT(newlen, len);
2229 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2230 /* dmemdump(newlen, 4); */
2232 while (len-- > siglen) {
2233 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2234 /* dmemdump(newlen, 1); */
2236 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2237 /* dmemdump(sigblob+pos, siglen); */
2241 /* Otherwise fall through and do it the easy way. */
2244 ssh2_pkt_addstring_start(pkt);
2245 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2249 * Examine the remote side's version string and compare it against
2250 * a list of known buggy implementations.
2252 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2254 char *imp; /* pointer to implementation part */
2256 imp += strcspn(imp, "-");
2258 imp += strcspn(imp, "-");
2261 ssh->remote_bugs = 0;
2264 * General notes on server version strings:
2265 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2266 * here -- in particular, we've heard of one that's perfectly happy
2267 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2268 * so we can't distinguish them.
2270 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2271 (ssh->cfg.sshbug_ignore1 == AUTO &&
2272 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2273 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2274 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2275 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2277 * These versions don't support SSH1_MSG_IGNORE, so we have
2278 * to use a different defence against password length
2281 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2282 logevent("We believe remote version has SSH-1 ignore bug");
2285 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2286 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2287 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2289 * These versions need a plain password sent; they can't
2290 * handle having a null and a random length of data after
2293 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2294 logevent("We believe remote version needs a plain SSH-1 password");
2297 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2298 (ssh->cfg.sshbug_rsa1 == AUTO &&
2299 (!strcmp(imp, "Cisco-1.25")))) {
2301 * These versions apparently have no clue whatever about
2302 * RSA authentication and will panic and die if they see
2303 * an AUTH_RSA message.
2305 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2306 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2309 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2310 (ssh->cfg.sshbug_hmac2 == AUTO &&
2311 !wc_match("* VShell", imp) &&
2312 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2313 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2314 wc_match("2.1 *", imp)))) {
2316 * These versions have the HMAC bug.
2318 ssh->remote_bugs |= BUG_SSH2_HMAC;
2319 logevent("We believe remote version has SSH-2 HMAC bug");
2322 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2323 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2324 !wc_match("* VShell", imp) &&
2325 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2327 * These versions have the key-derivation bug (failing to
2328 * include the literal shared secret in the hashes that
2329 * generate the keys).
2331 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2332 logevent("We believe remote version has SSH-2 key-derivation bug");
2335 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2336 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2337 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2338 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2340 * These versions have the SSH-2 RSA padding bug.
2342 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2343 logevent("We believe remote version has SSH-2 RSA padding bug");
2346 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2347 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2348 wc_match("OpenSSH_2.[0-2]*", imp))) {
2350 * These versions have the SSH-2 session-ID bug in
2351 * public-key authentication.
2353 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2354 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2357 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2358 (ssh->cfg.sshbug_rekey2 == AUTO &&
2359 (wc_match("DigiSSH_2.0", imp) ||
2360 wc_match("OpenSSH_2.[0-4]*", imp) ||
2361 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2362 wc_match("Sun_SSH_1.0", imp) ||
2363 wc_match("Sun_SSH_1.0.1", imp) ||
2364 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2365 wc_match("WeOnlyDo-*", imp)))) {
2367 * These versions have the SSH-2 rekey bug.
2369 ssh->remote_bugs |= BUG_SSH2_REKEY;
2370 logevent("We believe remote version has SSH-2 rekey bug");
2375 * The `software version' part of an SSH version string is required
2376 * to contain no spaces or minus signs.
2378 static void ssh_fix_verstring(char *str)
2380 /* Eat "SSH-<protoversion>-". */
2381 assert(*str == 'S'); str++;
2382 assert(*str == 'S'); str++;
2383 assert(*str == 'H'); str++;
2384 assert(*str == '-'); str++;
2385 while (*str && *str != '-') str++;
2386 assert(*str == '-'); str++;
2388 /* Convert minus signs and spaces in the remaining string into
2391 if (*str == '-' || *str == ' ')
2398 * Send an appropriate SSH version string.
2400 static void ssh_send_verstring(Ssh ssh, char *svers)
2404 if (ssh->version == 2) {
2406 * Construct a v2 version string.
2408 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2411 * Construct a v1 version string.
2413 verstring = dupprintf("SSH-%s-%s\012",
2414 (ssh_versioncmp(svers, "1.5") <= 0 ?
2419 ssh_fix_verstring(verstring);
2421 if (ssh->version == 2) {
2424 * Record our version string.
2426 len = strcspn(verstring, "\015\012");
2427 ssh->v_c = snewn(len + 1, char);
2428 memcpy(ssh->v_c, verstring, len);
2432 logeventf(ssh, "We claim version: %.*s",
2433 strcspn(verstring, "\015\012"), verstring);
2434 s_write(ssh, verstring, strlen(verstring));
2438 static int do_ssh_init(Ssh ssh, unsigned char c)
2440 struct do_ssh_init_state {
2448 crState(do_ssh_init_state);
2450 crBegin(ssh->do_ssh_init_crstate);
2452 /* Search for a line beginning with the string "SSH-" in the input. */
2454 if (c != 'S') goto no;
2456 if (c != 'S') goto no;
2458 if (c != 'H') goto no;
2460 if (c != '-') goto no;
2469 s->vstring = snewn(s->vstrsize, char);
2470 strcpy(s->vstring, "SSH-");
2474 crReturn(1); /* get another char */
2475 if (s->vslen >= s->vstrsize - 1) {
2477 s->vstring = sresize(s->vstring, s->vstrsize, char);
2479 s->vstring[s->vslen++] = c;
2482 s->version[s->i] = '\0';
2484 } else if (s->i < sizeof(s->version) - 1)
2485 s->version[s->i++] = c;
2486 } else if (c == '\012')
2490 ssh->agentfwd_enabled = FALSE;
2491 ssh->rdpkt2_state.incoming_sequence = 0;
2493 s->vstring[s->vslen] = 0;
2494 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2495 logeventf(ssh, "Server version: %s", s->vstring);
2496 ssh_detect_bugs(ssh, s->vstring);
2499 * Decide which SSH protocol version to support.
2502 /* Anything strictly below "2.0" means protocol 1 is supported. */
2503 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2504 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2505 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2507 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2508 bombout(("SSH protocol version 1 required by user but not provided by server"));
2511 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2512 bombout(("SSH protocol version 2 required by user but not provided by server"));
2516 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1))
2521 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2523 /* Send the version string, if we haven't already */
2524 if (ssh->cfg.sshprot != 3)
2525 ssh_send_verstring(ssh, s->version);
2527 if (ssh->version == 2) {
2530 * Record their version string.
2532 len = strcspn(s->vstring, "\015\012");
2533 ssh->v_s = snewn(len + 1, char);
2534 memcpy(ssh->v_s, s->vstring, len);
2538 * Initialise SSH-2 protocol.
2540 ssh->protocol = ssh2_protocol;
2541 ssh2_protocol_setup(ssh);
2542 ssh->s_rdpkt = ssh2_rdpkt;
2545 * Initialise SSH-1 protocol.
2547 ssh->protocol = ssh1_protocol;
2548 ssh1_protocol_setup(ssh);
2549 ssh->s_rdpkt = ssh1_rdpkt;
2551 if (ssh->version == 2)
2552 do_ssh2_transport(ssh, NULL, -1, NULL);
2554 update_specials_menu(ssh->frontend);
2555 ssh->state = SSH_STATE_BEFORE_SIZE;
2556 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2563 static void ssh_process_incoming_data(Ssh ssh,
2564 unsigned char **data, int *datalen)
2566 struct Packet *pktin;
2568 pktin = ssh->s_rdpkt(ssh, data, datalen);
2570 ssh->protocol(ssh, NULL, 0, pktin);
2571 ssh_free_packet(pktin);
2575 static void ssh_queue_incoming_data(Ssh ssh,
2576 unsigned char **data, int *datalen)
2578 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2583 static void ssh_process_queued_incoming_data(Ssh ssh)
2586 unsigned char *data;
2589 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2590 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2594 while (!ssh->frozen && len > 0)
2595 ssh_process_incoming_data(ssh, &data, &len);
2598 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2602 static void ssh_set_frozen(Ssh ssh, int frozen)
2605 sk_set_frozen(ssh->s, frozen);
2606 ssh->frozen = frozen;
2609 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2611 /* Log raw data, if we're in that mode. */
2613 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2616 crBegin(ssh->ssh_gotdata_crstate);
2619 * To begin with, feed the characters one by one to the
2620 * protocol initialisation / selection function do_ssh_init().
2621 * When that returns 0, we're done with the initial greeting
2622 * exchange and can move on to packet discipline.
2625 int ret; /* need not be kept across crReturn */
2627 crReturnV; /* more data please */
2628 ret = do_ssh_init(ssh, *data);
2636 * We emerge from that loop when the initial negotiation is
2637 * over and we have selected an s_rdpkt function. Now pass
2638 * everything to s_rdpkt, and then pass the resulting packets
2639 * to the proper protocol handler.
2643 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2645 ssh_queue_incoming_data(ssh, &data, &datalen);
2646 /* This uses up all data and cannot cause anything interesting
2647 * to happen; indeed, for anything to happen at all, we must
2648 * return, so break out. */
2650 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2651 /* This uses up some or all data, and may freeze the
2653 ssh_process_queued_incoming_data(ssh);
2655 /* This uses up some or all data, and may freeze the
2657 ssh_process_incoming_data(ssh, &data, &datalen);
2659 /* FIXME this is probably EBW. */
2660 if (ssh->state == SSH_STATE_CLOSED)
2663 /* We're out of data. Go and get some more. */
2669 static int ssh_do_close(Ssh ssh, int notify_exit)
2672 struct ssh_channel *c;
2674 ssh->state = SSH_STATE_CLOSED;
2675 expire_timer_context(ssh);
2680 notify_remote_exit(ssh->frontend);
2685 * Now we must shut down any port- and X-forwarded channels going
2686 * through this connection.
2688 if (ssh->channels) {
2689 while (NULL != (c = index234(ssh->channels, 0))) {
2692 x11_close(c->u.x11.s);
2695 pfd_close(c->u.pfd.s);
2698 del234(ssh->channels, c); /* moving next one to index 0 */
2699 if (ssh->version == 2)
2700 bufchain_clear(&c->v.v2.outbuffer);
2705 * Go through port-forwardings, and close any associated
2706 * listening sockets.
2708 if (ssh->portfwds) {
2709 struct ssh_portfwd *pf;
2710 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2711 /* Dispose of any listening socket. */
2713 pfd_terminate(pf->local);
2714 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2722 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2723 const char *error_msg, int error_code)
2725 Ssh ssh = (Ssh) plug;
2726 char addrbuf[256], *msg;
2728 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2731 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2733 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2739 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2742 Ssh ssh = (Ssh) plug;
2743 int need_notify = ssh_do_close(ssh, FALSE);
2746 if (!ssh->close_expected)
2747 error_msg = "Server unexpectedly closed network connection";
2749 error_msg = "Server closed network connection";
2752 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2756 notify_remote_exit(ssh->frontend);
2759 logevent(error_msg);
2760 if (!ssh->close_expected || !ssh->clean_exit)
2761 connection_fatal(ssh->frontend, "%s", error_msg);
2765 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2767 Ssh ssh = (Ssh) plug;
2768 ssh_gotdata(ssh, (unsigned char *)data, len);
2769 if (ssh->state == SSH_STATE_CLOSED) {
2770 ssh_do_close(ssh, TRUE);
2776 static void ssh_sent(Plug plug, int bufsize)
2778 Ssh ssh = (Ssh) plug;
2780 * If the send backlog on the SSH socket itself clears, we
2781 * should unthrottle the whole world if it was throttled.
2783 if (bufsize < SSH_MAX_BACKLOG)
2784 ssh_throttle_all(ssh, 0, bufsize);
2788 * Connect to specified host and port.
2789 * Returns an error message, or NULL on success.
2790 * Also places the canonical host name into `realhost'. It must be
2791 * freed by the caller.
2793 static const char *connect_to_host(Ssh ssh, char *host, int port,
2794 char **realhost, int nodelay, int keepalive)
2796 static const struct plug_function_table fn_table = {
2807 ssh->savedhost = snewn(1 + strlen(host), char);
2808 strcpy(ssh->savedhost, host);
2811 port = 22; /* default ssh port */
2812 ssh->savedport = port;
2817 logeventf(ssh, "Looking up host \"%s\"%s", host,
2818 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2819 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2820 addr = name_lookup(host, port, realhost, &ssh->cfg,
2821 ssh->cfg.addressfamily);
2822 if ((err = sk_addr_error(addr)) != NULL) {
2830 ssh->fn = &fn_table;
2831 ssh->s = new_connection(addr, *realhost, port,
2832 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2833 if ((err = sk_socket_error(ssh->s)) != NULL) {
2835 notify_remote_exit(ssh->frontend);
2840 * If the SSH version number's fixed, set it now, and if it's SSH-2,
2841 * send the version string too.
2843 if (ssh->cfg.sshprot == 0)
2845 if (ssh->cfg.sshprot == 3) {
2847 ssh_send_verstring(ssh, NULL);
2854 * Throttle or unthrottle the SSH connection.
2856 static void ssh1_throttle(Ssh ssh, int adjust)
2858 int old_count = ssh->v1_throttle_count;
2859 ssh->v1_throttle_count += adjust;
2860 assert(ssh->v1_throttle_count >= 0);
2861 if (ssh->v1_throttle_count && !old_count) {
2862 ssh_set_frozen(ssh, 1);
2863 } else if (!ssh->v1_throttle_count && old_count) {
2864 ssh_set_frozen(ssh, 0);
2869 * Throttle or unthrottle _all_ local data streams (for when sends
2870 * on the SSH connection itself back up).
2872 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2875 struct ssh_channel *c;
2877 if (enable == ssh->throttled_all)
2879 ssh->throttled_all = enable;
2880 ssh->overall_bufsize = bufsize;
2883 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2885 case CHAN_MAINSESSION:
2887 * This is treated separately, outside the switch.
2891 x11_override_throttle(c->u.x11.s, enable);
2894 /* Agent channels require no buffer management. */
2897 pfd_override_throttle(c->u.pfd.s, enable);
2903 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2905 Ssh ssh = (Ssh) sshv;
2907 ssh->agent_response = reply;
2908 ssh->agent_response_len = replylen;
2910 if (ssh->version == 1)
2911 do_ssh1_login(ssh, NULL, -1, NULL);
2913 do_ssh2_authconn(ssh, NULL, -1, NULL);
2916 static void ssh_dialog_callback(void *sshv, int ret)
2918 Ssh ssh = (Ssh) sshv;
2920 ssh->user_response = ret;
2922 if (ssh->version == 1)
2923 do_ssh1_login(ssh, NULL, -1, NULL);
2925 do_ssh2_transport(ssh, NULL, -1, NULL);
2928 * This may have unfrozen the SSH connection, so do a
2931 ssh_process_queued_incoming_data(ssh);
2934 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2936 struct ssh_channel *c = (struct ssh_channel *)cv;
2938 void *sentreply = reply;
2941 /* Fake SSH_AGENT_FAILURE. */
2942 sentreply = "\0\0\0\1\5";
2945 if (ssh->version == 2) {
2946 ssh2_add_channel_data(c, sentreply, replylen);
2949 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2950 PKT_INT, c->remoteid,
2953 PKT_DATA, sentreply, replylen,
2962 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2963 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2964 * => log `wire_reason'.
2966 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2967 int code, int clean_exit)
2971 client_reason = wire_reason;
2973 error = dupprintf("Disconnected: %s", client_reason);
2975 error = dupstr("Disconnected");
2977 if (ssh->version == 1) {
2978 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2980 } else if (ssh->version == 2) {
2981 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2982 ssh2_pkt_adduint32(pktout, code);
2983 ssh2_pkt_addstring(pktout, wire_reason);
2984 ssh2_pkt_addstring(pktout, "en"); /* language tag */
2985 ssh2_pkt_send_noqueue(ssh, pktout);
2988 ssh->close_expected = TRUE;
2989 ssh->clean_exit = clean_exit;
2990 ssh_closing((Plug)ssh, error, 0, 0);
2995 * Handle the key exchange and user authentication phases.
2997 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2998 struct Packet *pktin)
3001 unsigned char cookie[8], *ptr;
3002 struct RSAKey servkey, hostkey;
3003 struct MD5Context md5c;
3004 struct do_ssh1_login_state {
3006 unsigned char *rsabuf, *keystr1, *keystr2;
3007 unsigned long supported_ciphers_mask, supported_auths_mask;
3008 int tried_publickey, tried_agent;
3009 int tis_auth_refused, ccard_auth_refused;
3010 unsigned char session_id[16];
3013 void *publickey_blob;
3014 int publickey_bloblen;
3015 char *publickey_comment;
3016 int publickey_encrypted;
3017 prompts_t *cur_prompt;
3020 unsigned char request[5], *response, *p;
3030 crState(do_ssh1_login_state);
3032 crBegin(ssh->do_ssh1_login_crstate);
3037 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3038 bombout(("Public key packet not received"));
3042 logevent("Received public keys");
3044 ptr = ssh_pkt_getdata(pktin, 8);
3046 bombout(("SSH-1 public key packet stopped before random cookie"));
3049 memcpy(cookie, ptr, 8);
3051 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3052 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
3053 bombout(("Failed to read SSH-1 public keys from public key packet"));
3058 * Log the host key fingerprint.
3062 logevent("Host key fingerprint is:");
3063 strcpy(logmsg, " ");
3064 hostkey.comment = NULL;
3065 rsa_fingerprint(logmsg + strlen(logmsg),
3066 sizeof(logmsg) - strlen(logmsg), &hostkey);
3070 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3071 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3072 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3074 ssh->v1_local_protoflags =
3075 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3076 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3079 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3080 MD5Update(&md5c, s->keystr1, servkey.bytes);
3081 MD5Update(&md5c, cookie, 8);
3082 MD5Final(s->session_id, &md5c);
3084 for (i = 0; i < 32; i++)
3085 ssh->session_key[i] = random_byte();
3088 * Verify that the `bits' and `bytes' parameters match.
3090 if (hostkey.bits > hostkey.bytes * 8 ||
3091 servkey.bits > servkey.bytes * 8) {
3092 bombout(("SSH-1 public keys were badly formatted"));
3096 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
3098 s->rsabuf = snewn(s->len, unsigned char);
3101 * Verify the host key.
3105 * First format the key into a string.
3107 int len = rsastr_len(&hostkey);
3108 char fingerprint[100];
3109 char *keystr = snewn(len, char);
3110 rsastr_fmt(keystr, &hostkey);
3111 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3113 ssh_set_frozen(ssh, 1);
3114 s->dlgret = verify_ssh_host_key(ssh->frontend,
3115 ssh->savedhost, ssh->savedport,
3116 "rsa", keystr, fingerprint,
3117 ssh_dialog_callback, ssh);
3119 if (s->dlgret < 0) {
3123 bombout(("Unexpected data from server while waiting"
3124 " for user host key response"));
3127 } while (pktin || inlen > 0);
3128 s->dlgret = ssh->user_response;
3130 ssh_set_frozen(ssh, 0);
3132 if (s->dlgret == 0) {
3133 ssh_disconnect(ssh, "User aborted at host key verification",
3139 for (i = 0; i < 32; i++) {
3140 s->rsabuf[i] = ssh->session_key[i];
3142 s->rsabuf[i] ^= s->session_id[i];
3145 if (hostkey.bytes > servkey.bytes) {
3146 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3148 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3150 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3152 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3155 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3159 logevent("Encrypted session key");
3162 int cipher_chosen = 0, warn = 0;
3163 char *cipher_string = NULL;
3165 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3166 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3167 if (next_cipher == CIPHER_WARN) {
3168 /* If/when we choose a cipher, warn about it */
3170 } else if (next_cipher == CIPHER_AES) {
3171 /* XXX Probably don't need to mention this. */
3172 logevent("AES not supported in SSH-1, skipping");
3174 switch (next_cipher) {
3175 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3176 cipher_string = "3DES"; break;
3177 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3178 cipher_string = "Blowfish"; break;
3179 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3180 cipher_string = "single-DES"; break;
3182 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3186 if (!cipher_chosen) {
3187 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3188 bombout(("Server violates SSH-1 protocol by not "
3189 "supporting 3DES encryption"));
3191 /* shouldn't happen */
3192 bombout(("No supported ciphers found"));
3196 /* Warn about chosen cipher if necessary. */
3198 ssh_set_frozen(ssh, 1);
3199 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3200 ssh_dialog_callback, ssh);
3201 if (s->dlgret < 0) {
3205 bombout(("Unexpected data from server while waiting"
3206 " for user response"));
3209 } while (pktin || inlen > 0);
3210 s->dlgret = ssh->user_response;
3212 ssh_set_frozen(ssh, 0);
3213 if (s->dlgret == 0) {
3214 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3221 switch (s->cipher_type) {
3222 case SSH_CIPHER_3DES:
3223 logevent("Using 3DES encryption");
3225 case SSH_CIPHER_DES:
3226 logevent("Using single-DES encryption");
3228 case SSH_CIPHER_BLOWFISH:
3229 logevent("Using Blowfish encryption");
3233 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3234 PKT_CHAR, s->cipher_type,
3235 PKT_DATA, cookie, 8,
3236 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3237 PKT_DATA, s->rsabuf, s->len,
3238 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3240 logevent("Trying to enable encryption...");
3244 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3245 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3247 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3248 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3249 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3251 ssh->crcda_ctx = crcda_make_context();
3252 logevent("Installing CRC compensation attack detector");
3254 if (servkey.modulus) {
3255 sfree(servkey.modulus);
3256 servkey.modulus = NULL;
3258 if (servkey.exponent) {
3259 sfree(servkey.exponent);
3260 servkey.exponent = NULL;
3262 if (hostkey.modulus) {
3263 sfree(hostkey.modulus);
3264 hostkey.modulus = NULL;
3266 if (hostkey.exponent) {
3267 sfree(hostkey.exponent);
3268 hostkey.exponent = NULL;
3272 if (pktin->type != SSH1_SMSG_SUCCESS) {
3273 bombout(("Encryption not successfully enabled"));
3277 logevent("Successfully started encryption");
3279 fflush(stdout); /* FIXME eh? */
3281 if (!*ssh->cfg.username) {
3282 int ret; /* need not be kept over crReturn */
3283 s->cur_prompt = new_prompts(ssh->frontend);
3284 s->cur_prompt->to_server = TRUE;
3285 s->cur_prompt->name = dupstr("SSH login name");
3286 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
3287 lenof(s->username));
3288 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3291 crWaitUntil(!pktin);
3292 ret = get_userpass_input(s->cur_prompt, in, inlen);
3297 * Failed to get a username. Terminate.
3299 free_prompts(s->cur_prompt);
3300 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3303 memcpy(s->username, s->cur_prompt->prompts[0]->result,
3304 lenof(s->username));
3305 free_prompts(s->cur_prompt);
3307 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3308 s->username[sizeof(s->username)-1] = '\0';
3311 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3313 char *userlog = dupprintf("Sent username \"%s\"", s->username);
3315 if (flags & FLAG_INTERACTIVE &&
3316 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3317 c_write_str(ssh, userlog);
3318 c_write_str(ssh, "\r\n");
3326 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3327 /* We must not attempt PK auth. Pretend we've already tried it. */
3328 s->tried_publickey = s->tried_agent = 1;
3330 s->tried_publickey = s->tried_agent = 0;
3332 s->tis_auth_refused = s->ccard_auth_refused = 0;
3334 * Load the public half of any configured keyfile for later use.
3336 if (!filename_is_null(ssh->cfg.keyfile)) {
3338 logeventf(ssh, "Reading private key file \"%.150s\"",
3339 filename_to_str(&ssh->cfg.keyfile));
3340 keytype = key_type(&ssh->cfg.keyfile);
3341 if (keytype == SSH_KEYTYPE_SSH1) {
3343 if (rsakey_pubblob(&ssh->cfg.keyfile,
3344 &s->publickey_blob, &s->publickey_bloblen,
3345 &s->publickey_comment, &error)) {
3346 s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
3350 logeventf(ssh, "Unable to load private key (%s)", error);
3351 msgbuf = dupprintf("Unable to load private key file "
3352 "\"%.150s\" (%s)\r\n",
3353 filename_to_str(&ssh->cfg.keyfile),
3355 c_write_str(ssh, msgbuf);
3357 s->publickey_blob = NULL;
3361 logeventf(ssh, "Unable to use this key file (%s)",
3362 key_type_to_str(keytype));
3363 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3365 filename_to_str(&ssh->cfg.keyfile),
3366 key_type_to_str(keytype));
3367 c_write_str(ssh, msgbuf);
3369 s->publickey_blob = NULL;
3372 s->publickey_blob = NULL;
3374 while (pktin->type == SSH1_SMSG_FAILURE) {
3375 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3377 if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
3379 * Attempt RSA authentication using Pageant.
3385 logevent("Pageant is running. Requesting keys.");
3387 /* Request the keys held by the agent. */
3388 PUT_32BIT(s->request, 1);
3389 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3390 if (!agent_query(s->request, 5, &r, &s->responselen,
3391 ssh_agent_callback, ssh)) {
3395 bombout(("Unexpected data from server while waiting"
3396 " for agent response"));
3399 } while (pktin || inlen > 0);
3400 r = ssh->agent_response;
3401 s->responselen = ssh->agent_response_len;
3403 s->response = (unsigned char *) r;
3404 if (s->response && s->responselen >= 5 &&
3405 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3406 s->p = s->response + 5;
3407 s->nkeys = GET_32BIT(s->p);
3409 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3410 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3411 unsigned char *pkblob = s->p;
3415 do { /* do while (0) to make breaking easy */
3416 n = ssh1_read_bignum
3417 (s->p, s->responselen-(s->p-s->response),
3422 n = ssh1_read_bignum
3423 (s->p, s->responselen-(s->p-s->response),
3428 if (s->responselen - (s->p-s->response) < 4)
3430 s->commentlen = GET_32BIT(s->p);
3432 if (s->responselen - (s->p-s->response) <
3435 s->commentp = (char *)s->p;
3436 s->p += s->commentlen;
3440 logevent("Pageant key list packet was truncated");
3444 if (s->publickey_blob) {
3445 if (!memcmp(pkblob, s->publickey_blob,
3446 s->publickey_bloblen)) {
3447 logeventf(ssh, "Pageant key #%d matches "
3448 "configured key file", s->keyi);
3449 s->tried_publickey = 1;
3451 /* Skip non-configured key */
3454 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3455 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3456 PKT_BIGNUM, s->key.modulus, PKT_END);
3458 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3459 logevent("Key refused");
3462 logevent("Received RSA challenge");
3463 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3464 bombout(("Server's RSA challenge was badly formatted"));
3469 char *agentreq, *q, *ret;
3472 len = 1 + 4; /* message type, bit count */
3473 len += ssh1_bignum_length(s->key.exponent);
3474 len += ssh1_bignum_length(s->key.modulus);
3475 len += ssh1_bignum_length(s->challenge);
3476 len += 16; /* session id */
3477 len += 4; /* response format */
3478 agentreq = snewn(4 + len, char);
3479 PUT_32BIT(agentreq, len);
3481 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3482 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3484 q += ssh1_write_bignum(q, s->key.exponent);
3485 q += ssh1_write_bignum(q, s->key.modulus);
3486 q += ssh1_write_bignum(q, s->challenge);
3487 memcpy(q, s->session_id, 16);
3489 PUT_32BIT(q, 1); /* response format */
3490 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3491 ssh_agent_callback, ssh)) {
3496 bombout(("Unexpected data from server"
3497 " while waiting for agent"
3501 } while (pktin || inlen > 0);
3502 vret = ssh->agent_response;
3503 retlen = ssh->agent_response_len;
3508 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3509 logevent("Sending Pageant's response");
3510 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3511 PKT_DATA, ret + 5, 16,
3515 if (pktin->type == SSH1_SMSG_SUCCESS) {
3517 ("Pageant's response accepted");
3518 if (flags & FLAG_VERBOSE) {
3519 c_write_str(ssh, "Authenticated using"
3521 c_write(ssh, s->commentp,
3523 c_write_str(ssh, "\" from agent\r\n");
3528 ("Pageant's response not accepted");
3531 ("Pageant failed to answer challenge");
3535 logevent("No reply received from Pageant");
3538 freebn(s->key.exponent);
3539 freebn(s->key.modulus);
3540 freebn(s->challenge);
3545 if (s->publickey_blob && !s->tried_publickey)
3546 logevent("Configured key file not in Pageant");
3551 if (s->publickey_blob && !s->tried_publickey) {
3553 * Try public key authentication with the specified
3556 int got_passphrase; /* need not be kept over crReturn */
3557 if (flags & FLAG_VERBOSE)
3558 c_write_str(ssh, "Trying public key authentication.\r\n");
3559 logeventf(ssh, "Trying public key \"%s\"",
3560 filename_to_str(&ssh->cfg.keyfile));
3561 s->tried_publickey = 1;
3562 got_passphrase = FALSE;
3563 while (!got_passphrase) {
3565 * Get a passphrase, if necessary.
3567 char *passphrase = NULL; /* only written after crReturn */
3569 if (!s->publickey_encrypted) {
3570 if (flags & FLAG_VERBOSE)
3571 c_write_str(ssh, "No passphrase required.\r\n");
3574 int ret; /* need not be kept over crReturn */
3575 s->cur_prompt = new_prompts(ssh->frontend);
3576 s->cur_prompt->to_server = FALSE;
3577 s->cur_prompt->name = dupstr("SSH key passphrase");
3578 add_prompt(s->cur_prompt,
3579 dupprintf("Passphrase for key \"%.100s\": ",
3580 s->publickey_comment),
3581 FALSE, SSH_MAX_PASSWORD_LEN);
3582 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3585 crWaitUntil(!pktin);
3586 ret = get_userpass_input(s->cur_prompt, in, inlen);
3590 /* Failed to get a passphrase. Terminate. */
3591 free_prompts(s->cur_prompt);
3592 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3596 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3597 free_prompts(s->cur_prompt);
3600 * Try decrypting key with passphrase.
3602 ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
3605 memset(passphrase, 0, strlen(passphrase));
3609 /* Correct passphrase. */
3610 got_passphrase = TRUE;
3611 } else if (ret == 0) {
3612 c_write_str(ssh, "Couldn't load private key from ");
3613 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3614 c_write_str(ssh, " (");
3615 c_write_str(ssh, error);
3616 c_write_str(ssh, ").\r\n");
3617 got_passphrase = FALSE;
3618 break; /* go and try something else */
3619 } else if (ret == -1) {
3620 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3621 got_passphrase = FALSE;
3624 assert(0 && "unexpected return from loadrsakey()");
3625 got_passphrase = FALSE; /* placate optimisers */
3629 if (got_passphrase) {
3632 * Send a public key attempt.
3634 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3635 PKT_BIGNUM, s->key.modulus, PKT_END);
3638 if (pktin->type == SSH1_SMSG_FAILURE) {
3639 c_write_str(ssh, "Server refused our public key.\r\n");
3640 continue; /* go and try something else */
3642 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3643 bombout(("Bizarre response to offer of public key"));
3649 unsigned char buffer[32];
3650 Bignum challenge, response;
3652 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3653 bombout(("Server's RSA challenge was badly formatted"));
3656 response = rsadecrypt(challenge, &s->key);
3657 freebn(s->key.private_exponent);/* burn the evidence */
3659 for (i = 0; i < 32; i++) {
3660 buffer[i] = bignum_byte(response, 31 - i);
3664 MD5Update(&md5c, buffer, 32);
3665 MD5Update(&md5c, s->session_id, 16);
3666 MD5Final(buffer, &md5c);
3668 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3669 PKT_DATA, buffer, 16, PKT_END);
3676 if (pktin->type == SSH1_SMSG_FAILURE) {
3677 if (flags & FLAG_VERBOSE)
3678 c_write_str(ssh, "Failed to authenticate with"
3679 " our public key.\r\n");
3680 continue; /* go and try something else */
3681 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3682 bombout(("Bizarre response to RSA authentication response"));
3686 break; /* we're through! */
3692 * Otherwise, try various forms of password-like authentication.
3694 s->cur_prompt = new_prompts(ssh->frontend);
3696 if (ssh->cfg.try_tis_auth &&
3697 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3698 !s->tis_auth_refused) {
3699 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3700 logevent("Requested TIS authentication");
3701 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3703 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3704 logevent("TIS authentication declined");
3705 if (flags & FLAG_INTERACTIVE)
3706 c_write_str(ssh, "TIS authentication refused.\r\n");
3707 s->tis_auth_refused = 1;
3712 char *instr_suf, *prompt;
3714 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3716 bombout(("TIS challenge packet was badly formed"));
3719 logevent("Received TIS challenge");
3720 s->cur_prompt->to_server = TRUE;
3721 s->cur_prompt->name = dupstr("SSH TIS authentication");
3722 /* Prompt heuristic comes from OpenSSH */
3723 if (memchr(challenge, '\n', challengelen)) {
3724 instr_suf = dupstr("");
3725 prompt = dupprintf("%.*s", challengelen, challenge);
3727 instr_suf = dupprintf("%.*s", challengelen, challenge);
3728 prompt = dupstr("Response: ");
3730 s->cur_prompt->instruction =
3731 dupprintf("Using TIS authentication.%s%s",
3732 (*instr_suf) ? "\n" : "",
3734 s->cur_prompt->instr_reqd = TRUE;
3735 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3739 if (ssh->cfg.try_tis_auth &&
3740 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3741 !s->ccard_auth_refused) {
3742 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3743 logevent("Requested CryptoCard authentication");
3744 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3746 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3747 logevent("CryptoCard authentication declined");
3748 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3749 s->ccard_auth_refused = 1;
3754 char *instr_suf, *prompt;
3756 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3758 bombout(("CryptoCard challenge packet was badly formed"));
3761 logevent("Received CryptoCard challenge");
3762 s->cur_prompt->to_server = TRUE;
3763 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
3764 s->cur_prompt->name_reqd = FALSE;
3765 /* Prompt heuristic comes from OpenSSH */
3766 if (memchr(challenge, '\n', challengelen)) {
3767 instr_suf = dupstr("");
3768 prompt = dupprintf("%.*s", challengelen, challenge);
3770 instr_suf = dupprintf("%.*s", challengelen, challenge);
3771 prompt = dupstr("Response: ");
3773 s->cur_prompt->instruction =
3774 dupprintf("Using CryptoCard authentication.%s%s",
3775 (*instr_suf) ? "\n" : "",
3777 s->cur_prompt->instr_reqd = TRUE;
3778 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3782 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3783 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
3784 bombout(("No supported authentication methods available"));
3787 s->cur_prompt->to_server = TRUE;
3788 s->cur_prompt->name = dupstr("SSH password");
3789 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
3790 s->username, ssh->savedhost),
3791 FALSE, SSH_MAX_PASSWORD_LEN);
3795 * Show password prompt, having first obtained it via a TIS
3796 * or CryptoCard exchange if we're doing TIS or CryptoCard
3800 int ret; /* need not be kept over crReturn */
3801 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3804 crWaitUntil(!pktin);
3805 ret = get_userpass_input(s->cur_prompt, in, inlen);
3810 * Failed to get a password (for example
3811 * because one was supplied on the command line
3812 * which has already failed to work). Terminate.
3814 free_prompts(s->cur_prompt);
3815 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
3820 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3822 * Defence against traffic analysis: we send a
3823 * whole bunch of packets containing strings of
3824 * different lengths. One of these strings is the
3825 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3826 * The others are all random data in
3827 * SSH1_MSG_IGNORE packets. This way a passive
3828 * listener can't tell which is the password, and
3829 * hence can't deduce the password length.
3831 * Anybody with a password length greater than 16
3832 * bytes is going to have enough entropy in their
3833 * password that a listener won't find it _that_
3834 * much help to know how long it is. So what we'll
3837 * - if password length < 16, we send 15 packets
3838 * containing string lengths 1 through 15
3840 * - otherwise, we let N be the nearest multiple
3841 * of 8 below the password length, and send 8
3842 * packets containing string lengths N through
3843 * N+7. This won't obscure the order of
3844 * magnitude of the password length, but it will
3845 * introduce a bit of extra uncertainty.
3847 * A few servers can't deal with SSH1_MSG_IGNORE, at
3848 * least in this context. For these servers, we need
3849 * an alternative defence. We make use of the fact
3850 * that the password is interpreted as a C string:
3851 * so we can append a NUL, then some random data.
3853 * A few servers can deal with neither SSH1_MSG_IGNORE
3854 * here _nor_ a padded password string.
3855 * For these servers we are left with no defences
3856 * against password length sniffing.
3858 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
3859 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3861 * The server can deal with SSH1_MSG_IGNORE, so
3862 * we can use the primary defence.
3864 int bottom, top, pwlen, i;
3867 pwlen = strlen(s->cur_prompt->prompts[0]->result);
3869 bottom = 0; /* zero length passwords are OK! :-) */
3872 bottom = pwlen & ~7;
3876 assert(pwlen >= bottom && pwlen <= top);
3878 randomstr = snewn(top + 1, char);
3880 for (i = bottom; i <= top; i++) {
3882 defer_packet(ssh, s->pwpkt_type,
3883 PKTT_PASSWORD, PKT_STR,
3884 s->cur_prompt->prompts[0]->result,
3885 PKTT_OTHER, PKT_END);
3887 for (j = 0; j < i; j++) {
3889 randomstr[j] = random_byte();
3890 } while (randomstr[j] == '\0');
3892 randomstr[i] = '\0';
3893 defer_packet(ssh, SSH1_MSG_IGNORE,
3894 PKT_STR, randomstr, PKT_END);
3897 logevent("Sending password with camouflage packets");
3898 ssh_pkt_defersend(ssh);
3901 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3903 * The server can't deal with SSH1_MSG_IGNORE
3904 * but can deal with padded passwords, so we
3905 * can use the secondary defence.
3911 len = strlen(s->cur_prompt->prompts[0]->result);
3912 if (len < sizeof(string)) {
3914 strcpy(string, s->cur_prompt->prompts[0]->result);
3915 len++; /* cover the zero byte */
3916 while (len < sizeof(string)) {
3917 string[len++] = (char) random_byte();
3920 ss = s->cur_prompt->prompts[0]->result;
3922 logevent("Sending length-padded password");
3923 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3924 PKT_INT, len, PKT_DATA, ss, len,
3925 PKTT_OTHER, PKT_END);
3928 * The server is believed unable to cope with
3929 * any of our password camouflage methods.
3932 len = strlen(s->cur_prompt->prompts[0]->result);
3933 logevent("Sending unpadded password");
3934 send_packet(ssh, s->pwpkt_type,
3935 PKTT_PASSWORD, PKT_INT, len,
3936 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
3937 PKTT_OTHER, PKT_END);
3940 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3941 PKT_STR, s->cur_prompt->prompts[0]->result,
3942 PKTT_OTHER, PKT_END);
3944 logevent("Sent password");
3945 free_prompts(s->cur_prompt);
3947 if (pktin->type == SSH1_SMSG_FAILURE) {
3948 if (flags & FLAG_VERBOSE)
3949 c_write_str(ssh, "Access denied\r\n");
3950 logevent("Authentication refused");
3951 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3952 bombout(("Strange packet received, type %d", pktin->type));
3958 if (s->publickey_blob) {
3959 sfree(s->publickey_blob);
3960 sfree(s->publickey_comment);
3963 logevent("Authentication successful");
3968 void sshfwd_close(struct ssh_channel *c)
3972 if (ssh->state == SSH_STATE_CLOSED)
3975 if (c && !c->closes) {
3977 * If halfopen is true, we have sent
3978 * CHANNEL_OPEN for this channel, but it hasn't even been
3979 * acknowledged by the server. So we must set a close flag
3980 * on it now, and then when the server acks the channel
3981 * open, we can close it then.
3984 if (ssh->version == 1) {
3985 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3988 struct Packet *pktout;
3989 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3990 ssh2_pkt_adduint32(pktout, c->remoteid);
3991 ssh2_pkt_send(ssh, pktout);
3994 c->closes = 1; /* sent MSG_CLOSE */
3995 if (c->type == CHAN_X11) {
3997 logevent("Forwarded X11 connection terminated");
3998 } else if (c->type == CHAN_SOCKDATA ||
3999 c->type == CHAN_SOCKDATA_DORMANT) {
4001 logevent("Forwarded port closed");
4006 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4010 if (ssh->state == SSH_STATE_CLOSED)
4013 if (ssh->version == 1) {
4014 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4015 PKT_INT, c->remoteid,
4016 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
4017 PKTT_OTHER, PKT_END);
4019 * In SSH-1 we can return 0 here - implying that forwarded
4020 * connections are never individually throttled - because
4021 * the only circumstance that can cause throttling will be
4022 * the whole SSH connection backing up, in which case
4023 * _everything_ will be throttled as a whole.
4027 ssh2_add_channel_data(c, buf, len);
4028 return ssh2_try_send(c);
4032 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4036 if (ssh->state == SSH_STATE_CLOSED)
4039 if (ssh->version == 1) {
4040 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
4041 c->v.v1.throttling = 0;
4042 ssh1_throttle(ssh, -1);
4045 ssh2_set_window(c, c->v.v2.locmaxwin - bufsize);
4049 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4051 struct queued_handler *qh = ssh->qhead;
4055 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4058 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4059 ssh->packet_dispatch[qh->msg1] = NULL;
4062 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4063 ssh->packet_dispatch[qh->msg2] = NULL;
4067 ssh->qhead = qh->next;
4069 if (ssh->qhead->msg1 > 0) {
4070 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4071 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4073 if (ssh->qhead->msg2 > 0) {
4074 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4075 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4078 ssh->qhead = ssh->qtail = NULL;
4079 ssh->packet_dispatch[pktin->type] = NULL;
4082 qh->handler(ssh, pktin, qh->ctx);
4087 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4088 chandler_fn_t handler, void *ctx)
4090 struct queued_handler *qh;
4092 qh = snew(struct queued_handler);
4095 qh->handler = handler;
4099 if (ssh->qtail == NULL) {
4103 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4104 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4107 assert(ssh->packet_dispatch[qh->msg2] == NULL);
4108 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4111 ssh->qtail->next = qh;
4116 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4118 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4120 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4121 SSH2_MSG_REQUEST_SUCCESS)) {
4122 logeventf(ssh, "Remote port forwarding from %s enabled",
4125 logeventf(ssh, "Remote port forwarding from %s refused",
4128 rpf = del234(ssh->rportfwds, pf);
4134 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
4136 const char *portfwd_strptr = cfg->portfwd;
4137 struct ssh_portfwd *epf;
4140 if (!ssh->portfwds) {
4141 ssh->portfwds = newtree234(ssh_portcmp);
4144 * Go through the existing port forwardings and tag them
4145 * with status==DESTROY. Any that we want to keep will be
4146 * re-enabled (status==KEEP) as we go through the
4147 * configuration and find out which bits are the same as
4150 struct ssh_portfwd *epf;
4152 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4153 epf->status = DESTROY;
4156 while (*portfwd_strptr) {
4157 char address_family, type;
4158 int sport,dport,sserv,dserv;
4159 char sports[256], dports[256], saddr[256], host[256];
4162 address_family = 'A';
4164 if (*portfwd_strptr == 'A' ||
4165 *portfwd_strptr == '4' ||
4166 *portfwd_strptr == '6')
4167 address_family = *portfwd_strptr++;
4168 if (*portfwd_strptr == 'L' ||
4169 *portfwd_strptr == 'R' ||
4170 *portfwd_strptr == 'D')
4171 type = *portfwd_strptr++;
4176 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4177 if (*portfwd_strptr == ':') {
4179 * We've seen a colon in the middle of the
4180 * source port number. This means that
4181 * everything we've seen until now is the
4182 * source _address_, so we'll move it into
4183 * saddr and start sports from the beginning
4188 if (ssh->version == 1 && type == 'R') {
4189 logeventf(ssh, "SSH-1 cannot handle remote source address "
4190 "spec \"%s\"; ignoring", sports);
4192 strcpy(saddr, sports);
4195 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4199 if (*portfwd_strptr == '\t')
4202 while (*portfwd_strptr && *portfwd_strptr != ':') {
4203 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4206 if (*portfwd_strptr == ':')
4209 while (*portfwd_strptr) {
4210 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4214 dport = atoi(dports);
4218 dport = net_service_lookup(dports);
4220 logeventf(ssh, "Service lookup failed for destination"
4221 " port \"%s\"", dports);
4225 while (*portfwd_strptr) portfwd_strptr++;
4229 portfwd_strptr++; /* eat the NUL and move to next one */
4231 sport = atoi(sports);
4235 sport = net_service_lookup(sports);
4237 logeventf(ssh, "Service lookup failed for source"
4238 " port \"%s\"", sports);
4241 if (sport && dport) {
4242 /* Set up a description of the source port. */
4243 struct ssh_portfwd *pfrec, *epfrec;
4245 pfrec = snew(struct ssh_portfwd);
4247 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4248 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4249 pfrec->sport = sport;
4250 pfrec->daddr = *host ? dupstr(host) : NULL;
4251 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4252 pfrec->dport = dport;
4253 pfrec->local = NULL;
4254 pfrec->remote = NULL;
4255 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4256 address_family == '6' ? ADDRTYPE_IPV6 :
4259 epfrec = add234(ssh->portfwds, pfrec);
4260 if (epfrec != pfrec) {
4262 * We already have a port forwarding with precisely
4263 * these parameters. Hence, no need to do anything;
4264 * simply tag the existing one as KEEP.
4266 epfrec->status = KEEP;
4267 free_portfwd(pfrec);
4269 pfrec->status = CREATE;
4275 * Now go through and destroy any port forwardings which were
4278 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4279 if (epf->status == DESTROY) {
4282 message = dupprintf("%s port forwarding from %s%s%d",
4283 epf->type == 'L' ? "local" :
4284 epf->type == 'R' ? "remote" : "dynamic",
4285 epf->saddr ? epf->saddr : "",
4286 epf->saddr ? ":" : "",
4289 if (epf->type != 'D') {
4290 char *msg2 = dupprintf("%s to %s:%d", message,
4291 epf->daddr, epf->dport);
4296 logeventf(ssh, "Cancelling %s", message);
4300 struct ssh_rportfwd *rpf = epf->remote;
4301 struct Packet *pktout;
4304 * Cancel the port forwarding at the server
4307 if (ssh->version == 1) {
4309 * We cannot cancel listening ports on the
4310 * server side in SSH-1! There's no message
4311 * to support it. Instead, we simply remove
4312 * the rportfwd record from the local end
4313 * so that any connections the server tries
4314 * to make on it are rejected.
4317 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4318 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4319 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4321 ssh2_pkt_addstring(pktout, epf->saddr);
4322 } else if (ssh->cfg.rport_acceptall) {
4323 /* XXX: ssh->cfg.rport_acceptall may not represent
4324 * what was used to open the original connection,
4325 * since it's reconfigurable. */
4326 ssh2_pkt_addstring(pktout, "0.0.0.0");
4328 ssh2_pkt_addstring(pktout, "127.0.0.1");
4330 ssh2_pkt_adduint32(pktout, epf->sport);
4331 ssh2_pkt_send(ssh, pktout);
4334 del234(ssh->rportfwds, rpf);
4336 } else if (epf->local) {
4337 pfd_terminate(epf->local);
4340 delpos234(ssh->portfwds, i);
4342 i--; /* so we don't skip one in the list */
4346 * And finally, set up any new port forwardings (status==CREATE).
4348 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4349 if (epf->status == CREATE) {
4350 char *sportdesc, *dportdesc;
4351 sportdesc = dupprintf("%s%s%s%s%d%s",
4352 epf->saddr ? epf->saddr : "",
4353 epf->saddr ? ":" : "",
4354 epf->sserv ? epf->sserv : "",
4355 epf->sserv ? "(" : "",
4357 epf->sserv ? ")" : "");
4358 if (epf->type == 'D') {
4361 dportdesc = dupprintf("%s:%s%s%d%s",
4363 epf->dserv ? epf->dserv : "",
4364 epf->dserv ? "(" : "",
4366 epf->dserv ? ")" : "");
4369 if (epf->type == 'L') {
4370 const char *err = pfd_addforward(epf->daddr, epf->dport,
4371 epf->saddr, epf->sport,
4374 epf->addressfamily);
4376 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4377 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4378 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4379 sportdesc, dportdesc,
4380 err ? " failed: " : "", err ? err : "");
4381 } else if (epf->type == 'D') {
4382 const char *err = pfd_addforward(NULL, -1,
4383 epf->saddr, epf->sport,
4386 epf->addressfamily);
4388 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4389 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4390 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4392 err ? " failed: " : "", err ? err : "");
4394 struct ssh_rportfwd *pf;
4397 * Ensure the remote port forwardings tree exists.
4399 if (!ssh->rportfwds) {
4400 if (ssh->version == 1)
4401 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4403 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4406 pf = snew(struct ssh_rportfwd);
4407 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4408 pf->dhost[lenof(pf->dhost)-1] = '\0';
4409 pf->dport = epf->dport;
4410 pf->sport = epf->sport;
4411 if (add234(ssh->rportfwds, pf) != pf) {
4412 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4413 epf->daddr, epf->dport);
4416 logeventf(ssh, "Requesting remote port %s"
4417 " forward to %s", sportdesc, dportdesc);
4419 pf->sportdesc = sportdesc;
4424 if (ssh->version == 1) {
4425 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4426 PKT_INT, epf->sport,
4427 PKT_STR, epf->daddr,
4428 PKT_INT, epf->dport,
4430 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4432 ssh_rportfwd_succfail, pf);
4434 struct Packet *pktout;
4435 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4436 ssh2_pkt_addstring(pktout, "tcpip-forward");
4437 ssh2_pkt_addbool(pktout, 1);/* want reply */
4439 ssh2_pkt_addstring(pktout, epf->saddr);
4440 } else if (cfg->rport_acceptall) {
4441 ssh2_pkt_addstring(pktout, "0.0.0.0");
4443 ssh2_pkt_addstring(pktout, "127.0.0.1");
4445 ssh2_pkt_adduint32(pktout, epf->sport);
4446 ssh2_pkt_send(ssh, pktout);
4448 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4449 SSH2_MSG_REQUEST_FAILURE,
4450 ssh_rportfwd_succfail, pf);
4459 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4462 int stringlen, bufsize;
4464 ssh_pkt_getstring(pktin, &string, &stringlen);
4465 if (string == NULL) {
4466 bombout(("Incoming terminal data packet was badly formed"));
4470 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4472 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4473 ssh->v1_stdout_throttling = 1;
4474 ssh1_throttle(ssh, +1);
4478 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4480 /* Remote side is trying to open a channel to talk to our
4481 * X-Server. Give them back a local channel number. */
4482 struct ssh_channel *c;
4483 int remoteid = ssh_pkt_getuint32(pktin);
4485 logevent("Received X11 connect request");
4486 /* Refuse if X11 forwarding is disabled. */
4487 if (!ssh->X11_fwd_enabled) {
4488 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4489 PKT_INT, remoteid, PKT_END);
4490 logevent("Rejected X11 connect request");
4492 c = snew(struct ssh_channel);
4495 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4496 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4497 logevent("Opening X11 forward connection failed");
4499 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4500 PKT_INT, remoteid, PKT_END);
4503 ("Opening X11 forward connection succeeded");
4504 c->remoteid = remoteid;
4505 c->halfopen = FALSE;
4506 c->localid = alloc_channel_id(ssh);
4508 c->v.v1.throttling = 0;
4509 c->type = CHAN_X11; /* identify channel type */
4510 add234(ssh->channels, c);
4511 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4512 PKT_INT, c->remoteid, PKT_INT,
4513 c->localid, PKT_END);
4514 logevent("Opened X11 forward channel");
4519 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4521 /* Remote side is trying to open a channel to talk to our
4522 * agent. Give them back a local channel number. */
4523 struct ssh_channel *c;
4524 int remoteid = ssh_pkt_getuint32(pktin);
4526 /* Refuse if agent forwarding is disabled. */
4527 if (!ssh->agentfwd_enabled) {
4528 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4529 PKT_INT, remoteid, PKT_END);
4531 c = snew(struct ssh_channel);
4533 c->remoteid = remoteid;
4534 c->halfopen = FALSE;
4535 c->localid = alloc_channel_id(ssh);
4537 c->v.v1.throttling = 0;
4538 c->type = CHAN_AGENT; /* identify channel type */
4539 c->u.a.lensofar = 0;
4540 add234(ssh->channels, c);
4541 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4542 PKT_INT, c->remoteid, PKT_INT, c->localid,
4547 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4549 /* Remote side is trying to open a channel to talk to a
4550 * forwarded port. Give them back a local channel number. */
4551 struct ssh_channel *c;
4552 struct ssh_rportfwd pf, *pfp;
4557 c = snew(struct ssh_channel);
4560 remoteid = ssh_pkt_getuint32(pktin);
4561 ssh_pkt_getstring(pktin, &host, &hostsize);
4562 port = ssh_pkt_getuint32(pktin);
4564 if (hostsize >= lenof(pf.dhost))
4565 hostsize = lenof(pf.dhost)-1;
4566 memcpy(pf.dhost, host, hostsize);
4567 pf.dhost[hostsize] = '\0';
4569 pfp = find234(ssh->rportfwds, &pf, NULL);
4572 logeventf(ssh, "Rejected remote port open request for %s:%d",
4574 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4575 PKT_INT, remoteid, PKT_END);
4577 logeventf(ssh, "Received remote port open request for %s:%d",
4579 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4580 c, &ssh->cfg, pfp->pfrec->addressfamily);
4582 logeventf(ssh, "Port open failed: %s", e);
4584 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4585 PKT_INT, remoteid, PKT_END);
4587 c->remoteid = remoteid;
4588 c->halfopen = FALSE;
4589 c->localid = alloc_channel_id(ssh);
4591 c->v.v1.throttling = 0;
4592 c->type = CHAN_SOCKDATA; /* identify channel type */
4593 add234(ssh->channels, c);
4594 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4595 PKT_INT, c->remoteid, PKT_INT,
4596 c->localid, PKT_END);
4597 logevent("Forwarded port opened successfully");
4602 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4604 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4605 unsigned int localid = ssh_pkt_getuint32(pktin);
4606 struct ssh_channel *c;
4608 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4609 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4610 c->remoteid = localid;
4611 c->halfopen = FALSE;
4612 c->type = CHAN_SOCKDATA;
4613 c->v.v1.throttling = 0;
4614 pfd_confirm(c->u.pfd.s);
4617 if (c && c->closes) {
4619 * We have a pending close on this channel,
4620 * which we decided on before the server acked
4621 * the channel open. So now we know the
4622 * remoteid, we can close it again.
4624 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4625 PKT_INT, c->remoteid, PKT_END);
4629 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4631 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4632 struct ssh_channel *c;
4634 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4635 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4636 logevent("Forwarded connection refused by server");
4637 pfd_close(c->u.pfd.s);
4638 del234(ssh->channels, c);
4643 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4645 /* Remote side closes a channel. */
4646 unsigned i = ssh_pkt_getuint32(pktin);
4647 struct ssh_channel *c;
4648 c = find234(ssh->channels, &i, ssh_channelfind);
4649 if (c && !c->halfopen) {
4652 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4654 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4655 logevent("Forwarded X11 connection terminated");
4656 assert(c->u.x11.s != NULL);
4657 x11_close(c->u.x11.s);
4660 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4661 logevent("Forwarded port closed");
4662 assert(c->u.pfd.s != NULL);
4663 pfd_close(c->u.pfd.s);
4667 c->closes |= (closetype << 2); /* seen this message */
4668 if (!(c->closes & closetype)) {
4669 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4671 c->closes |= closetype; /* sent it too */
4674 if (c->closes == 15) {
4675 del234(ssh->channels, c);
4679 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4680 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4681 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4686 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4688 /* Data sent down one of our channels. */
4689 int i = ssh_pkt_getuint32(pktin);
4692 struct ssh_channel *c;
4694 ssh_pkt_getstring(pktin, &p, &len);
4696 c = find234(ssh->channels, &i, ssh_channelfind);
4701 bufsize = x11_send(c->u.x11.s, p, len);
4704 bufsize = pfd_send(c->u.pfd.s, p, len);
4707 /* Data for an agent message. Buffer it. */
4709 if (c->u.a.lensofar < 4) {
4710 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
4711 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4715 c->u.a.lensofar += l;
4717 if (c->u.a.lensofar == 4) {
4719 4 + GET_32BIT(c->u.a.msglen);
4720 c->u.a.message = snewn(c->u.a.totallen,
4722 memcpy(c->u.a.message, c->u.a.msglen, 4);
4724 if (c->u.a.lensofar >= 4 && len > 0) {
4726 min(c->u.a.totallen - c->u.a.lensofar,
4728 memcpy(c->u.a.message + c->u.a.lensofar, p,
4732 c->u.a.lensofar += l;
4734 if (c->u.a.lensofar == c->u.a.totallen) {
4737 if (agent_query(c->u.a.message,
4740 ssh_agentf_callback, c))
4741 ssh_agentf_callback(c, reply, replylen);
4742 sfree(c->u.a.message);
4743 c->u.a.lensofar = 0;
4746 bufsize = 0; /* agent channels never back up */
4749 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4750 c->v.v1.throttling = 1;
4751 ssh1_throttle(ssh, +1);
4756 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4758 ssh->exitcode = ssh_pkt_getuint32(pktin);
4759 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4760 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4762 * In case `helpful' firewalls or proxies tack
4763 * extra human-readable text on the end of the
4764 * session which we might mistake for another
4765 * encrypted packet, we close the session once
4766 * we've sent EXIT_CONFIRMATION.
4768 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
4771 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4772 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4774 struct Packet *pktout = (struct Packet *)data;
4776 unsigned int arg = 0;
4777 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4778 if (i == lenof(ssh_ttymodes)) return;
4779 switch (ssh_ttymodes[i].type) {
4781 arg = ssh_tty_parse_specchar(val);
4784 arg = ssh_tty_parse_boolean(val);
4787 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4788 ssh2_pkt_addbyte(pktout, arg);
4792 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4793 struct Packet *pktin)
4795 crBegin(ssh->do_ssh1_connection_crstate);
4797 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4798 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4799 ssh1_smsg_stdout_stderr_data;
4801 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4802 ssh1_msg_channel_open_confirmation;
4803 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4804 ssh1_msg_channel_open_failure;
4805 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4806 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4807 ssh1_msg_channel_close;
4808 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4809 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4811 if (ssh->cfg.agentfwd && agent_exists()) {
4812 logevent("Requesting agent forwarding");
4813 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4817 if (pktin->type != SSH1_SMSG_SUCCESS
4818 && pktin->type != SSH1_SMSG_FAILURE) {
4819 bombout(("Protocol confusion"));
4821 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4822 logevent("Agent forwarding refused");
4824 logevent("Agent forwarding enabled");
4825 ssh->agentfwd_enabled = TRUE;
4826 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4830 if (ssh->cfg.x11_forward) {
4831 char proto[20], data[64];
4832 logevent("Requesting X11 forwarding");
4833 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4834 data, sizeof(data), ssh->cfg.x11_auth);
4835 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4837 * Note that while we blank the X authentication data here, we don't
4838 * take any special action to blank the start of an X11 channel,
4839 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4840 * without having session blanking enabled is likely to leak your
4841 * cookie into the log.
4843 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4844 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4846 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
4847 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4850 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4852 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
4857 if (pktin->type != SSH1_SMSG_SUCCESS
4858 && pktin->type != SSH1_SMSG_FAILURE) {
4859 bombout(("Protocol confusion"));
4861 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4862 logevent("X11 forwarding refused");
4864 logevent("X11 forwarding enabled");
4865 ssh->X11_fwd_enabled = TRUE;
4866 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4870 ssh_setup_portfwd(ssh, &ssh->cfg);
4871 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4873 if (!ssh->cfg.nopty) {
4875 /* Unpick the terminal-speed string. */
4876 /* XXX perhaps we should allow no speeds to be sent. */
4877 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4878 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4879 /* Send the pty request. */
4880 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4881 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4882 ssh_pkt_adduint32(pkt, ssh->term_height);
4883 ssh_pkt_adduint32(pkt, ssh->term_width);
4884 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4885 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4886 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4887 ssh1_send_ttymode, (void *)pkt);
4888 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4889 ssh_pkt_adduint32(pkt, ssh->ispeed);
4890 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4891 ssh_pkt_adduint32(pkt, ssh->ospeed);
4892 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4894 ssh->state = SSH_STATE_INTERMED;
4898 if (pktin->type != SSH1_SMSG_SUCCESS
4899 && pktin->type != SSH1_SMSG_FAILURE) {
4900 bombout(("Protocol confusion"));
4902 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4903 c_write_str(ssh, "Server refused to allocate pty\r\n");
4904 ssh->editing = ssh->echoing = 1;
4906 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4907 ssh->ospeed, ssh->ispeed);
4909 ssh->editing = ssh->echoing = 1;
4912 if (ssh->cfg.compression) {
4913 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4917 if (pktin->type != SSH1_SMSG_SUCCESS
4918 && pktin->type != SSH1_SMSG_FAILURE) {
4919 bombout(("Protocol confusion"));
4921 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4922 c_write_str(ssh, "Server refused to compress\r\n");
4924 logevent("Started compression");
4925 ssh->v1_compressing = TRUE;
4926 ssh->cs_comp_ctx = zlib_compress_init();
4927 logevent("Initialised zlib (RFC1950) compression");
4928 ssh->sc_comp_ctx = zlib_decompress_init();
4929 logevent("Initialised zlib (RFC1950) decompression");
4933 * Start the shell or command.
4935 * Special case: if the first-choice command is an SSH-2
4936 * subsystem (hence not usable here) and the second choice
4937 * exists, we fall straight back to that.
4940 char *cmd = ssh->cfg.remote_cmd_ptr;
4942 if (!cmd) cmd = ssh->cfg.remote_cmd;
4944 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4945 cmd = ssh->cfg.remote_cmd_ptr2;
4946 ssh->fallback_cmd = TRUE;
4949 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4951 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4952 logevent("Started session");
4955 ssh->state = SSH_STATE_SESSION;
4956 if (ssh->size_needed)
4957 ssh_size(ssh, ssh->term_width, ssh->term_height);
4958 if (ssh->eof_needed)
4959 ssh_special(ssh, TS_EOF);
4962 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4964 ssh->channels = newtree234(ssh_channelcmp);
4968 * By this point, most incoming packets are already being
4969 * handled by the dispatch table, and we need only pay
4970 * attention to the unusual ones.
4975 if (pktin->type == SSH1_SMSG_SUCCESS) {
4976 /* may be from EXEC_SHELL on some servers */
4977 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4978 /* may be from EXEC_SHELL on some servers
4979 * if no pty is available or in other odd cases. Ignore */
4981 bombout(("Strange packet received: type %d", pktin->type));
4986 int len = min(inlen, 512);
4987 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
4988 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
4989 PKTT_OTHER, PKT_END);
5000 * Handle the top-level SSH-2 protocol.
5002 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5007 ssh_pkt_getstring(pktin, &msg, &msglen);
5008 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5011 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5013 /* log reason code in disconnect message */
5017 ssh_pkt_getstring(pktin, &msg, &msglen);
5018 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5021 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5023 /* Do nothing, because we're ignoring it! Duhh. */
5026 static void ssh1_protocol_setup(Ssh ssh)
5031 * Most messages are handled by the coroutines.
5033 for (i = 0; i < 256; i++)
5034 ssh->packet_dispatch[i] = NULL;
5037 * These special message types we install handlers for.
5039 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5040 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5041 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5044 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5045 struct Packet *pktin)
5047 unsigned char *in=(unsigned char*)vin;
5048 if (ssh->state == SSH_STATE_CLOSED)
5051 if (pktin && ssh->packet_dispatch[pktin->type]) {
5052 ssh->packet_dispatch[pktin->type](ssh, pktin);
5056 if (!ssh->protocol_initial_phase_done) {
5057 if (do_ssh1_login(ssh, in, inlen, pktin))
5058 ssh->protocol_initial_phase_done = TRUE;
5063 do_ssh1_connection(ssh, in, inlen, pktin);
5067 * Utility routine for decoding comma-separated strings in KEXINIT.
5069 static int in_commasep_string(char *needle, char *haystack, int haylen)
5072 if (!needle || !haystack) /* protect against null pointers */
5074 needlen = strlen(needle);
5077 * Is it at the start of the string?
5079 if (haylen >= needlen && /* haystack is long enough */
5080 !memcmp(needle, haystack, needlen) && /* initial match */
5081 (haylen == needlen || haystack[needlen] == ',')
5082 /* either , or EOS follows */
5086 * If not, search for the next comma and resume after that.
5087 * If no comma found, terminate.
5089 while (haylen > 0 && *haystack != ',')
5090 haylen--, haystack++;
5093 haylen--, haystack++; /* skip over comma itself */
5098 * Similar routine for checking whether we have the first string in a list.
5100 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5103 if (!needle || !haystack) /* protect against null pointers */
5105 needlen = strlen(needle);
5107 * Is it at the start of the string?
5109 if (haylen >= needlen && /* haystack is long enough */
5110 !memcmp(needle, haystack, needlen) && /* initial match */
5111 (haylen == needlen || haystack[needlen] == ',')
5112 /* either , or EOS follows */
5120 * SSH-2 key creation method.
5121 * (Currently assumes 2 lots of any hash are sufficient to generate
5122 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5124 #define SSH2_MKKEY_ITERS (2)
5125 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5126 unsigned char *keyspace)
5128 const struct ssh_hash *h = ssh->kex->hash;
5130 /* First hlen bytes. */
5132 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5133 hash_mpint(h, s, K);
5134 h->bytes(s, H, h->hlen);
5135 h->bytes(s, &chr, 1);
5136 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5137 h->final(s, keyspace);
5138 /* Next hlen bytes. */
5140 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5141 hash_mpint(h, s, K);
5142 h->bytes(s, H, h->hlen);
5143 h->bytes(s, keyspace, h->hlen);
5144 h->final(s, keyspace + h->hlen);
5148 * Handle the SSH-2 transport layer.
5150 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5151 struct Packet *pktin)
5153 unsigned char *in = (unsigned char *)vin;
5154 struct do_ssh2_transport_state {
5155 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5156 Bignum p, g, e, f, K;
5159 int kex_init_value, kex_reply_value;
5160 const struct ssh_mac **maclist;
5162 const struct ssh2_cipher *cscipher_tobe;
5163 const struct ssh2_cipher *sccipher_tobe;
5164 const struct ssh_mac *csmac_tobe;
5165 const struct ssh_mac *scmac_tobe;
5166 const struct ssh_compress *cscomp_tobe;
5167 const struct ssh_compress *sccomp_tobe;
5168 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5169 int hostkeylen, siglen, rsakeylen;
5170 void *hkey; /* actual host key */
5171 void *rsakey; /* for RSA kex */
5172 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5173 int n_preferred_kex;
5174 const struct ssh_kexes *preferred_kex[KEX_MAX];
5175 int n_preferred_ciphers;
5176 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5177 const struct ssh_compress *preferred_comp;
5178 int got_session_id, activated_authconn;
5179 struct Packet *pktout;
5184 crState(do_ssh2_transport_state);
5186 crBegin(ssh->do_ssh2_transport_crstate);
5188 s->cscipher_tobe = s->sccipher_tobe = NULL;
5189 s->csmac_tobe = s->scmac_tobe = NULL;
5190 s->cscomp_tobe = s->sccomp_tobe = NULL;
5192 s->got_session_id = s->activated_authconn = FALSE;
5195 * Be prepared to work around the buggy MAC problem.
5197 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5198 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5200 s->maclist = macs, s->nmacs = lenof(macs);
5203 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5205 int i, j, commalist_started;
5208 * Set up the preferred key exchange. (NULL => warn below here)
5210 s->n_preferred_kex = 0;
5211 for (i = 0; i < KEX_MAX; i++) {
5212 switch (ssh->cfg.ssh_kexlist[i]) {
5214 s->preferred_kex[s->n_preferred_kex++] =
5215 &ssh_diffiehellman_gex;
5218 s->preferred_kex[s->n_preferred_kex++] =
5219 &ssh_diffiehellman_group14;
5222 s->preferred_kex[s->n_preferred_kex++] =
5223 &ssh_diffiehellman_group1;
5226 s->preferred_kex[s->n_preferred_kex++] =
5230 /* Flag for later. Don't bother if it's the last in
5232 if (i < KEX_MAX - 1) {
5233 s->preferred_kex[s->n_preferred_kex++] = NULL;
5240 * Set up the preferred ciphers. (NULL => warn below here)
5242 s->n_preferred_ciphers = 0;
5243 for (i = 0; i < CIPHER_MAX; i++) {
5244 switch (ssh->cfg.ssh_cipherlist[i]) {
5245 case CIPHER_BLOWFISH:
5246 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5249 if (ssh->cfg.ssh2_des_cbc) {
5250 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5254 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5257 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5259 case CIPHER_ARCFOUR:
5260 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5263 /* Flag for later. Don't bother if it's the last in
5265 if (i < CIPHER_MAX - 1) {
5266 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5273 * Set up preferred compression.
5275 if (ssh->cfg.compression)
5276 s->preferred_comp = &ssh_zlib;
5278 s->preferred_comp = &ssh_comp_none;
5281 * Enable queueing of outgoing auth- or connection-layer
5282 * packets while we are in the middle of a key exchange.
5284 ssh->queueing = TRUE;
5287 * Flag that KEX is in progress.
5289 ssh->kex_in_progress = TRUE;
5292 * Construct and send our key exchange packet.
5294 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5295 for (i = 0; i < 16; i++)
5296 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5297 /* List key exchange algorithms. */
5298 ssh2_pkt_addstring_start(s->pktout);
5299 commalist_started = 0;
5300 for (i = 0; i < s->n_preferred_kex; i++) {
5301 const struct ssh_kexes *k = s->preferred_kex[i];
5302 if (!k) continue; /* warning flag */
5303 for (j = 0; j < k->nkexes; j++) {
5304 if (commalist_started)
5305 ssh2_pkt_addstring_str(s->pktout, ",");
5306 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5307 commalist_started = 1;
5310 /* List server host key algorithms. */
5311 ssh2_pkt_addstring_start(s->pktout);
5312 for (i = 0; i < lenof(hostkey_algs); i++) {
5313 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5314 if (i < lenof(hostkey_algs) - 1)
5315 ssh2_pkt_addstring_str(s->pktout, ",");
5317 /* List client->server encryption algorithms. */
5318 ssh2_pkt_addstring_start(s->pktout);
5319 commalist_started = 0;
5320 for (i = 0; i < s->n_preferred_ciphers; i++) {
5321 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5322 if (!c) continue; /* warning flag */
5323 for (j = 0; j < c->nciphers; j++) {
5324 if (commalist_started)
5325 ssh2_pkt_addstring_str(s->pktout, ",");
5326 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5327 commalist_started = 1;
5330 /* List server->client encryption algorithms. */
5331 ssh2_pkt_addstring_start(s->pktout);
5332 commalist_started = 0;
5333 for (i = 0; i < s->n_preferred_ciphers; i++) {
5334 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5335 if (!c) continue; /* warning flag */
5336 for (j = 0; j < c->nciphers; j++) {
5337 if (commalist_started)
5338 ssh2_pkt_addstring_str(s->pktout, ",");
5339 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5340 commalist_started = 1;
5343 /* List client->server MAC algorithms. */
5344 ssh2_pkt_addstring_start(s->pktout);
5345 for (i = 0; i < s->nmacs; i++) {
5346 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5347 if (i < s->nmacs - 1)
5348 ssh2_pkt_addstring_str(s->pktout, ",");
5350 /* List server->client MAC algorithms. */
5351 ssh2_pkt_addstring_start(s->pktout);
5352 for (i = 0; i < s->nmacs; i++) {
5353 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5354 if (i < s->nmacs - 1)
5355 ssh2_pkt_addstring_str(s->pktout, ",");
5357 /* List client->server compression algorithms. */
5358 ssh2_pkt_addstring_start(s->pktout);
5359 assert(lenof(compressions) > 1);
5360 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5361 for (i = 0; i < lenof(compressions); i++) {
5362 const struct ssh_compress *c = compressions[i];
5363 if (c != s->preferred_comp) {
5364 ssh2_pkt_addstring_str(s->pktout, ",");
5365 ssh2_pkt_addstring_str(s->pktout, c->name);
5368 /* List server->client compression algorithms. */
5369 ssh2_pkt_addstring_start(s->pktout);
5370 assert(lenof(compressions) > 1);
5371 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5372 for (i = 0; i < lenof(compressions); i++) {
5373 const struct ssh_compress *c = compressions[i];
5374 if (c != s->preferred_comp) {
5375 ssh2_pkt_addstring_str(s->pktout, ",");
5376 ssh2_pkt_addstring_str(s->pktout, c->name);
5379 /* List client->server languages. Empty list. */
5380 ssh2_pkt_addstring_start(s->pktout);
5381 /* List server->client languages. Empty list. */
5382 ssh2_pkt_addstring_start(s->pktout);
5383 /* First KEX packet does _not_ follow, because we're not that brave. */
5384 ssh2_pkt_addbool(s->pktout, FALSE);
5386 ssh2_pkt_adduint32(s->pktout, 0);
5389 s->our_kexinitlen = s->pktout->length - 5;
5390 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5391 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5393 ssh2_pkt_send_noqueue(ssh, s->pktout);
5399 * Now examine the other side's KEXINIT to see what we're up
5403 char *str, *preferred;
5406 if (pktin->type != SSH2_MSG_KEXINIT) {
5407 bombout(("expected key exchange packet from server"));
5411 ssh->hostkey = NULL;
5412 s->cscipher_tobe = NULL;
5413 s->sccipher_tobe = NULL;
5414 s->csmac_tobe = NULL;
5415 s->scmac_tobe = NULL;
5416 s->cscomp_tobe = NULL;
5417 s->sccomp_tobe = NULL;
5418 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5420 pktin->savedpos += 16; /* skip garbage cookie */
5421 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5424 for (i = 0; i < s->n_preferred_kex; i++) {
5425 const struct ssh_kexes *k = s->preferred_kex[i];
5429 for (j = 0; j < k->nkexes; j++) {
5430 if (!preferred) preferred = k->list[j]->name;
5431 if (in_commasep_string(k->list[j]->name, str, len)) {
5432 ssh->kex = k->list[j];
5441 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5442 str ? str : "(null)"));
5446 * Note that the server's guess is considered wrong if it doesn't match
5447 * the first algorithm in our list, even if it's still the algorithm
5450 s->guessok = first_in_commasep_string(preferred, str, len);
5451 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5452 for (i = 0; i < lenof(hostkey_algs); i++) {
5453 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5454 ssh->hostkey = hostkey_algs[i];
5458 s->guessok = s->guessok &&
5459 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5460 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5461 for (i = 0; i < s->n_preferred_ciphers; i++) {
5462 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5464 s->warn_cscipher = TRUE;
5466 for (j = 0; j < c->nciphers; j++) {
5467 if (in_commasep_string(c->list[j]->name, str, len)) {
5468 s->cscipher_tobe = c->list[j];
5473 if (s->cscipher_tobe)
5476 if (!s->cscipher_tobe) {
5477 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5478 str ? str : "(null)"));
5482 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5483 for (i = 0; i < s->n_preferred_ciphers; i++) {
5484 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5486 s->warn_sccipher = TRUE;
5488 for (j = 0; j < c->nciphers; j++) {
5489 if (in_commasep_string(c->list[j]->name, str, len)) {
5490 s->sccipher_tobe = c->list[j];
5495 if (s->sccipher_tobe)
5498 if (!s->sccipher_tobe) {
5499 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5500 str ? str : "(null)"));
5504 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5505 for (i = 0; i < s->nmacs; i++) {
5506 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5507 s->csmac_tobe = s->maclist[i];
5511 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5512 for (i = 0; i < s->nmacs; i++) {
5513 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5514 s->scmac_tobe = s->maclist[i];
5518 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5519 for (i = 0; i < lenof(compressions) + 1; i++) {
5520 const struct ssh_compress *c =
5521 i == 0 ? s->preferred_comp : compressions[i - 1];
5522 if (in_commasep_string(c->name, str, len)) {
5527 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5528 for (i = 0; i < lenof(compressions) + 1; i++) {
5529 const struct ssh_compress *c =
5530 i == 0 ? s->preferred_comp : compressions[i - 1];
5531 if (in_commasep_string(c->name, str, len)) {
5536 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5537 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5538 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5541 ssh_set_frozen(ssh, 1);
5542 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5544 ssh_dialog_callback, ssh);
5545 if (s->dlgret < 0) {
5549 bombout(("Unexpected data from server while"
5550 " waiting for user response"));
5553 } while (pktin || inlen > 0);
5554 s->dlgret = ssh->user_response;
5556 ssh_set_frozen(ssh, 0);
5557 if (s->dlgret == 0) {
5558 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5564 if (s->warn_cscipher) {
5565 ssh_set_frozen(ssh, 1);
5566 s->dlgret = askalg(ssh->frontend,
5567 "client-to-server cipher",
5568 s->cscipher_tobe->name,
5569 ssh_dialog_callback, ssh);
5570 if (s->dlgret < 0) {
5574 bombout(("Unexpected data from server while"
5575 " waiting for user response"));
5578 } while (pktin || inlen > 0);
5579 s->dlgret = ssh->user_response;
5581 ssh_set_frozen(ssh, 0);
5582 if (s->dlgret == 0) {
5583 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5589 if (s->warn_sccipher) {
5590 ssh_set_frozen(ssh, 1);
5591 s->dlgret = askalg(ssh->frontend,
5592 "server-to-client cipher",
5593 s->sccipher_tobe->name,
5594 ssh_dialog_callback, ssh);
5595 if (s->dlgret < 0) {
5599 bombout(("Unexpected data from server while"
5600 " waiting for user response"));
5603 } while (pktin || inlen > 0);
5604 s->dlgret = ssh->user_response;
5606 ssh_set_frozen(ssh, 0);
5607 if (s->dlgret == 0) {
5608 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5614 ssh->exhash = ssh->kex->hash->init();
5615 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5616 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5617 hash_string(ssh->kex->hash, ssh->exhash,
5618 s->our_kexinit, s->our_kexinitlen);
5619 sfree(s->our_kexinit);
5620 if (pktin->length > 5)
5621 hash_string(ssh->kex->hash, ssh->exhash,
5622 pktin->data + 5, pktin->length - 5);
5624 if (s->ignorepkt) /* first_kex_packet_follows */
5625 crWaitUntil(pktin); /* Ignore packet */
5628 if (ssh->kex->main_type == KEXTYPE_DH) {
5630 * Work out the number of bits of key we will need from the
5631 * key exchange. We start with the maximum key length of
5637 csbits = s->cscipher_tobe->keylen;
5638 scbits = s->sccipher_tobe->keylen;
5639 s->nbits = (csbits > scbits ? csbits : scbits);
5641 /* The keys only have hlen-bit entropy, since they're based on
5642 * a hash. So cap the key size at hlen bits. */
5643 if (s->nbits > ssh->kex->hash->hlen * 8)
5644 s->nbits = ssh->kex->hash->hlen * 8;
5647 * If we're doing Diffie-Hellman group exchange, start by
5648 * requesting a group.
5650 if (!ssh->kex->pdata) {
5651 logevent("Doing Diffie-Hellman group exchange");
5652 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
5654 * Work out how big a DH group we will need to allow that
5657 s->pbits = 512 << ((s->nbits - 1) / 64);
5658 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5659 ssh2_pkt_adduint32(s->pktout, s->pbits);
5660 ssh2_pkt_send_noqueue(ssh, s->pktout);
5663 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5664 bombout(("expected key exchange group packet from server"));
5667 s->p = ssh2_pkt_getmp(pktin);
5668 s->g = ssh2_pkt_getmp(pktin);
5669 if (!s->p || !s->g) {
5670 bombout(("unable to read mp-ints from incoming group packet"));
5673 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5674 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5675 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5677 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
5678 ssh->kex_ctx = dh_setup_group(ssh->kex);
5679 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5680 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5681 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5682 ssh->kex->groupname);
5685 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
5686 ssh->kex->hash->text_name);
5688 * Now generate and send e for Diffie-Hellman.
5690 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5691 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5692 s->pktout = ssh2_pkt_init(s->kex_init_value);
5693 ssh2_pkt_addmp(s->pktout, s->e);
5694 ssh2_pkt_send_noqueue(ssh, s->pktout);
5696 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5698 if (pktin->type != s->kex_reply_value) {
5699 bombout(("expected key exchange reply packet from server"));
5702 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5703 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5704 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5705 s->f = ssh2_pkt_getmp(pktin);
5707 bombout(("unable to parse key exchange reply packet"));
5710 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5712 s->K = dh_find_K(ssh->kex_ctx, s->f);
5714 /* We assume everything from now on will be quick, and it might
5715 * involve user interaction. */
5716 set_busy_status(ssh->frontend, BUSY_NOT);
5718 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5719 if (!ssh->kex->pdata) {
5720 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5721 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5722 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5724 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5725 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5727 dh_cleanup(ssh->kex_ctx);
5729 if (!ssh->kex->pdata) {
5734 logeventf(ssh, "Doing RSA key exchange with hash %s",
5735 ssh->kex->hash->text_name);
5736 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
5738 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
5742 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
5743 bombout(("expected RSA public key packet from server"));
5747 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5748 hash_string(ssh->kex->hash, ssh->exhash,
5749 s->hostkeydata, s->hostkeylen);
5750 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5754 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
5755 s->rsakeydata = snewn(s->rsakeylen, char);
5756 memcpy(s->rsakeydata, keydata, s->rsakeylen);
5759 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
5761 sfree(s->rsakeydata);
5762 bombout(("unable to parse RSA public key from server"));
5766 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
5769 * Next, set up a shared secret K, of precisely KLEN -
5770 * 2*HLEN - 49 bits, where KLEN is the bit length of the
5771 * RSA key modulus and HLEN is the bit length of the hash
5775 int klen = ssh_rsakex_klen(s->rsakey);
5776 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
5778 unsigned char *kstr1, *kstr2, *outstr;
5779 int kstr1len, kstr2len, outstrlen;
5781 s->K = bn_power_2(nbits - 1);
5783 for (i = 0; i < nbits; i++) {
5785 byte = random_byte();
5787 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
5791 * Encode this as an mpint.
5793 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
5794 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
5795 PUT_32BIT(kstr2, kstr1len);
5796 memcpy(kstr2 + 4, kstr1, kstr1len);
5799 * Encrypt it with the given RSA key.
5801 outstrlen = (klen + 7) / 8;
5802 outstr = snewn(outstrlen, unsigned char);
5803 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
5804 outstr, outstrlen, s->rsakey);
5807 * And send it off in a return packet.
5809 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
5810 ssh2_pkt_addstring_start(s->pktout);
5811 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
5812 ssh2_pkt_send_noqueue(ssh, s->pktout);
5814 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
5821 ssh_rsakex_freekey(s->rsakey);
5824 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
5825 sfree(s->rsakeydata);
5826 bombout(("expected signature packet from server"));
5830 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5832 sfree(s->rsakeydata);
5835 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
5836 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
5837 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
5839 ssh->kex_ctx = NULL;
5842 debug(("Exchange hash is:\n"));
5843 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
5847 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5848 (char *)s->exchange_hash,
5849 ssh->kex->hash->hlen)) {
5850 bombout(("Server's host key did not match the signature supplied"));
5855 * Authenticate remote host: verify host key. (We've already
5856 * checked the signature of the exchange hash.)
5858 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5859 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5860 ssh_set_frozen(ssh, 1);
5861 s->dlgret = verify_ssh_host_key(ssh->frontend,
5862 ssh->savedhost, ssh->savedport,
5863 ssh->hostkey->keytype, s->keystr,
5865 ssh_dialog_callback, ssh);
5866 if (s->dlgret < 0) {
5870 bombout(("Unexpected data from server while waiting"
5871 " for user host key response"));
5874 } while (pktin || inlen > 0);
5875 s->dlgret = ssh->user_response;
5877 ssh_set_frozen(ssh, 0);
5878 if (s->dlgret == 0) {
5879 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5883 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5884 logevent("Host key fingerprint is:");
5885 logevent(s->fingerprint);
5887 sfree(s->fingerprint);
5889 ssh->hostkey->freekey(s->hkey);
5892 * The exchange hash from the very first key exchange is also
5893 * the session id, used in session key construction and
5896 if (!s->got_session_id) {
5897 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
5898 memcpy(ssh->v2_session_id, s->exchange_hash,
5899 sizeof(s->exchange_hash));
5900 ssh->v2_session_id_len = ssh->kex->hash->hlen;
5901 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
5902 s->got_session_id = TRUE;
5906 * Send SSH2_MSG_NEWKEYS.
5908 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5909 ssh2_pkt_send_noqueue(ssh, s->pktout);
5910 ssh->outgoing_data_size = 0; /* start counting from here */
5913 * We've sent client NEWKEYS, so create and initialise
5914 * client-to-server session keys.
5916 if (ssh->cs_cipher_ctx)
5917 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5918 ssh->cscipher = s->cscipher_tobe;
5919 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5921 if (ssh->cs_mac_ctx)
5922 ssh->csmac->free_context(ssh->cs_mac_ctx);
5923 ssh->csmac = s->csmac_tobe;
5924 ssh->cs_mac_ctx = ssh->csmac->make_context();
5926 if (ssh->cs_comp_ctx)
5927 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5928 ssh->cscomp = s->cscomp_tobe;
5929 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5932 * Set IVs on client-to-server keys. Here we use the exchange
5933 * hash from the _first_ key exchange.
5936 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
5937 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5938 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
5939 assert((ssh->cscipher->keylen+7) / 8 <=
5940 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5941 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5942 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
5943 assert(ssh->cscipher->blksize <=
5944 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5945 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5946 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
5947 assert(ssh->csmac->len <=
5948 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5949 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5950 memset(keyspace, 0, sizeof(keyspace));
5953 logeventf(ssh, "Initialised %.200s client->server encryption",
5954 ssh->cscipher->text_name);
5955 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5956 ssh->csmac->text_name);
5957 if (ssh->cscomp->text_name)
5958 logeventf(ssh, "Initialised %s compression",
5959 ssh->cscomp->text_name);
5962 * Now our end of the key exchange is complete, we can send all
5963 * our queued higher-layer packets.
5965 ssh->queueing = FALSE;
5966 ssh2_pkt_queuesend(ssh);
5969 * Expect SSH2_MSG_NEWKEYS from server.
5972 if (pktin->type != SSH2_MSG_NEWKEYS) {
5973 bombout(("expected new-keys packet from server"));
5976 ssh->incoming_data_size = 0; /* start counting from here */
5979 * We've seen server NEWKEYS, so create and initialise
5980 * server-to-client session keys.
5982 if (ssh->sc_cipher_ctx)
5983 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5984 ssh->sccipher = s->sccipher_tobe;
5985 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5987 if (ssh->sc_mac_ctx)
5988 ssh->scmac->free_context(ssh->sc_mac_ctx);
5989 ssh->scmac = s->scmac_tobe;
5990 ssh->sc_mac_ctx = ssh->scmac->make_context();
5992 if (ssh->sc_comp_ctx)
5993 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5994 ssh->sccomp = s->sccomp_tobe;
5995 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5998 * Set IVs on server-to-client keys. Here we use the exchange
5999 * hash from the _first_ key exchange.
6002 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6003 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6004 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6005 assert((ssh->sccipher->keylen+7) / 8 <=
6006 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6007 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6008 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6009 assert(ssh->sccipher->blksize <=
6010 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6011 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6012 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6013 assert(ssh->scmac->len <=
6014 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6015 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6016 memset(keyspace, 0, sizeof(keyspace));
6018 logeventf(ssh, "Initialised %.200s server->client encryption",
6019 ssh->sccipher->text_name);
6020 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6021 ssh->scmac->text_name);
6022 if (ssh->sccomp->text_name)
6023 logeventf(ssh, "Initialised %s decompression",
6024 ssh->sccomp->text_name);
6027 * Free shared secret.
6032 * Key exchange is over. Loop straight back round if we have a
6033 * deferred rekey reason.
6035 if (ssh->deferred_rekey_reason) {
6036 logevent(ssh->deferred_rekey_reason);
6038 ssh->deferred_rekey_reason = NULL;
6039 goto begin_key_exchange;
6043 * Otherwise, schedule a timer for our next rekey.
6045 ssh->kex_in_progress = FALSE;
6046 ssh->last_rekey = GETTICKCOUNT();
6047 if (ssh->cfg.ssh_rekey_time != 0)
6048 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6052 * If this is the first key exchange phase, we must pass the
6053 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6054 * wants to see it but because it will need time to initialise
6055 * itself before it sees an actual packet. In subsequent key
6056 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6057 * it would only confuse the layer above.
6059 if (s->activated_authconn) {
6062 s->activated_authconn = TRUE;
6065 * Now we're encrypting. Begin returning 1 to the protocol main
6066 * function so that other things can run on top of the
6067 * transport. If we ever see a KEXINIT, we must go back to the
6070 * We _also_ go back to the start if we see pktin==NULL and
6071 * inlen==-1, because this is a special signal meaning
6072 * `initiate client-driven rekey', and `in' contains a message
6073 * giving the reason for the rekey.
6075 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6076 (!pktin && inlen == -1))) {
6081 logevent("Server initiated key re-exchange");
6084 * Special case: if the server bug is set that doesn't
6085 * allow rekeying, we give a different log message and
6086 * continue waiting. (If such a server _initiates_ a rekey,
6087 * we process it anyway!)
6089 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6090 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6092 /* Reset the counters, so that at least this message doesn't
6093 * hit the event log _too_ often. */
6094 ssh->outgoing_data_size = 0;
6095 ssh->incoming_data_size = 0;
6096 if (ssh->cfg.ssh_rekey_time != 0) {
6098 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6101 goto wait_for_rekey; /* this is utterly horrid */
6103 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6106 goto begin_key_exchange;
6112 * Add data to an SSH-2 channel output buffer.
6114 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6117 bufchain_add(&c->v.v2.outbuffer, buf, len);
6121 * Attempt to send data on an SSH-2 channel.
6123 static int ssh2_try_send(struct ssh_channel *c)
6126 struct Packet *pktout;
6128 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6131 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6132 if ((unsigned)len > c->v.v2.remwindow)
6133 len = c->v.v2.remwindow;
6134 if ((unsigned)len > c->v.v2.remmaxpkt)
6135 len = c->v.v2.remmaxpkt;
6136 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6137 ssh2_pkt_adduint32(pktout, c->remoteid);
6138 ssh2_pkt_addstring_start(pktout);
6139 dont_log_data(ssh, pktout, PKTLOG_OMIT);
6140 ssh2_pkt_addstring_data(pktout, data, len);
6141 end_log_omission(ssh, pktout);
6142 ssh2_pkt_send(ssh, pktout);
6143 bufchain_consume(&c->v.v2.outbuffer, len);
6144 c->v.v2.remwindow -= len;
6148 * After having sent as much data as we can, return the amount
6151 return bufchain_size(&c->v.v2.outbuffer);
6154 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
6158 return; /* don't send on closing channels */
6159 bufsize = ssh2_try_send(c);
6162 case CHAN_MAINSESSION:
6163 /* stdin need not receive an unthrottle
6164 * notification since it will be polled */
6167 x11_unthrottle(c->u.x11.s);
6170 /* agent sockets are request/response and need no
6171 * buffer management */
6174 pfd_unthrottle(c->u.pfd.s);
6181 * Potentially enlarge the window on an SSH-2 channel.
6183 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6188 * Never send WINDOW_ADJUST for a channel that the remote side
6189 * already thinks it's closed; there's no point, since it won't
6190 * be sending any more data anyway.
6196 * Only send a WINDOW_ADJUST if there's significantly more window
6197 * available than the other end thinks there is. This saves us
6198 * sending a WINDOW_ADJUST for every character in a shell session.
6200 * "Significant" is arbitrarily defined as half the window size.
6202 if (newwin / 2 >= c->v.v2.locwindow) {
6203 struct Packet *pktout;
6205 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6206 ssh2_pkt_adduint32(pktout, c->remoteid);
6207 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6208 ssh2_pkt_send(ssh, pktout);
6209 c->v.v2.locwindow = newwin;
6213 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6215 unsigned i = ssh_pkt_getuint32(pktin);
6216 struct ssh_channel *c;
6217 c = find234(ssh->channels, &i, ssh_channelfind);
6218 if (c && !c->closes) {
6219 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6220 ssh2_try_send_and_unthrottle(c);
6224 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6228 unsigned i = ssh_pkt_getuint32(pktin);
6229 struct ssh_channel *c;
6230 c = find234(ssh->channels, &i, ssh_channelfind);
6232 return; /* nonexistent channel */
6233 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6234 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6235 return; /* extended but not stderr */
6236 ssh_pkt_getstring(pktin, &data, &length);
6239 c->v.v2.locwindow -= length;
6241 case CHAN_MAINSESSION:
6243 from_backend(ssh->frontend, pktin->type ==
6244 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6248 bufsize = x11_send(c->u.x11.s, data, length);
6251 bufsize = pfd_send(c->u.pfd.s, data, length);
6254 while (length > 0) {
6255 if (c->u.a.lensofar < 4) {
6256 unsigned int l = min(4 - c->u.a.lensofar,
6258 memcpy(c->u.a.msglen + c->u.a.lensofar,
6262 c->u.a.lensofar += l;
6264 if (c->u.a.lensofar == 4) {
6266 4 + GET_32BIT(c->u.a.msglen);
6267 c->u.a.message = snewn(c->u.a.totallen,
6269 memcpy(c->u.a.message, c->u.a.msglen, 4);
6271 if (c->u.a.lensofar >= 4 && length > 0) {
6273 min(c->u.a.totallen - c->u.a.lensofar,
6275 memcpy(c->u.a.message + c->u.a.lensofar,
6279 c->u.a.lensofar += l;
6281 if (c->u.a.lensofar == c->u.a.totallen) {
6284 if (agent_query(c->u.a.message,
6287 ssh_agentf_callback, c))
6288 ssh_agentf_callback(c, reply, replylen);
6289 sfree(c->u.a.message);
6290 c->u.a.lensofar = 0;
6297 * If we are not buffering too much data,
6298 * enlarge the window again at the remote side.
6299 * If we are buffering too much, we may still
6300 * need to adjust the window if the server's
6303 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6304 c->v.v2.locmaxwin - bufsize : 0);
6308 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6310 unsigned i = ssh_pkt_getuint32(pktin);
6311 struct ssh_channel *c;
6313 c = find234(ssh->channels, &i, ssh_channelfind);
6315 return; /* nonexistent channel */
6317 if (c->type == CHAN_X11) {
6319 * Remote EOF on an X11 channel means we should
6320 * wrap up and close the channel ourselves.
6322 x11_close(c->u.x11.s);
6324 } else if (c->type == CHAN_AGENT) {
6326 } else if (c->type == CHAN_SOCKDATA) {
6327 pfd_close(c->u.pfd.s);
6332 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6334 unsigned i = ssh_pkt_getuint32(pktin);
6335 struct ssh_channel *c;
6336 struct Packet *pktout;
6338 c = find234(ssh->channels, &i, ssh_channelfind);
6339 if (!c || c->halfopen) {
6340 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6341 c ? "half-open" : "nonexistent", i));
6344 /* Do pre-close processing on the channel. */
6346 case CHAN_MAINSESSION:
6347 ssh->mainchan = NULL;
6348 update_specials_menu(ssh->frontend);
6351 if (c->u.x11.s != NULL)
6352 x11_close(c->u.x11.s);
6359 if (c->u.pfd.s != NULL)
6360 pfd_close(c->u.pfd.s);
6364 if (c->closes == 0) {
6365 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6366 ssh2_pkt_adduint32(pktout, c->remoteid);
6367 ssh2_pkt_send(ssh, pktout);
6369 del234(ssh->channels, c);
6370 bufchain_clear(&c->v.v2.outbuffer);
6374 * See if that was the last channel left open.
6375 * (This is only our termination condition if we're
6376 * not running in -N mode.)
6378 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6380 * We used to send SSH_MSG_DISCONNECT here,
6381 * because I'd believed that _every_ conforming
6382 * SSH-2 connection had to end with a disconnect
6383 * being sent by at least one side; apparently
6384 * I was wrong and it's perfectly OK to
6385 * unceremoniously slam the connection shut
6386 * when you're done, and indeed OpenSSH feels
6387 * this is more polite than sending a
6388 * DISCONNECT. So now we don't.
6390 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6394 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6396 unsigned i = ssh_pkt_getuint32(pktin);
6397 struct ssh_channel *c;
6398 struct Packet *pktout;
6400 c = find234(ssh->channels, &i, ssh_channelfind);
6402 return; /* nonexistent channel */
6403 if (c->type != CHAN_SOCKDATA_DORMANT)
6404 return; /* dunno why they're confirming this */
6405 c->remoteid = ssh_pkt_getuint32(pktin);
6406 c->halfopen = FALSE;
6407 c->type = CHAN_SOCKDATA;
6408 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6409 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6411 pfd_confirm(c->u.pfd.s);
6414 * We have a pending close on this channel,
6415 * which we decided on before the server acked
6416 * the channel open. So now we know the
6417 * remoteid, we can close it again.
6419 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6420 ssh2_pkt_adduint32(pktout, c->remoteid);
6421 ssh2_pkt_send(ssh, pktout);
6425 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6427 static const char *const reasons[] = {
6428 "<unknown reason code>",
6429 "Administratively prohibited",
6431 "Unknown channel type",
6432 "Resource shortage",
6434 unsigned i = ssh_pkt_getuint32(pktin);
6435 unsigned reason_code;
6436 char *reason_string;
6438 struct ssh_channel *c;
6439 c = find234(ssh->channels, &i, ssh_channelfind);
6441 return; /* nonexistent channel */
6442 if (c->type != CHAN_SOCKDATA_DORMANT)
6443 return; /* dunno why they're failing this */
6445 reason_code = ssh_pkt_getuint32(pktin);
6446 if (reason_code >= lenof(reasons))
6447 reason_code = 0; /* ensure reasons[reason_code] in range */
6448 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6449 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6450 reasons[reason_code], reason_length, reason_string);
6452 pfd_close(c->u.pfd.s);
6454 del234(ssh->channels, c);
6458 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6462 int typelen, want_reply;
6463 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6464 struct ssh_channel *c;
6465 struct Packet *pktout;
6467 localid = ssh_pkt_getuint32(pktin);
6468 ssh_pkt_getstring(pktin, &type, &typelen);
6469 want_reply = ssh2_pkt_getbool(pktin);
6472 * First, check that the channel exists. Otherwise,
6473 * we can instantly disconnect with a rude message.
6475 c = find234(ssh->channels, &localid, ssh_channelfind);
6477 char *buf = dupprintf("Received channel request for nonexistent"
6478 " channel %d", localid);
6479 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6485 * Having got the channel number, we now look at
6486 * the request type string to see if it's something
6489 if (c == ssh->mainchan) {
6491 * We recognise "exit-status" and "exit-signal" on
6492 * the primary channel.
6494 if (typelen == 11 &&
6495 !memcmp(type, "exit-status", 11)) {
6497 ssh->exitcode = ssh_pkt_getuint32(pktin);
6498 logeventf(ssh, "Server sent command exit status %d",
6500 reply = SSH2_MSG_CHANNEL_SUCCESS;
6502 } else if (typelen == 11 &&
6503 !memcmp(type, "exit-signal", 11)) {
6505 int is_plausible = TRUE, is_int = FALSE;
6506 char *fmt_sig = "", *fmt_msg = "";
6508 int msglen = 0, core = FALSE;
6509 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6510 * provide an `int' for the signal, despite its
6511 * having been a `string' in the drafts since at
6512 * least 2001. (Fixed in session.c 1.147.) Try to
6513 * infer which we can safely parse it as. */
6515 unsigned char *p = pktin->body +
6517 long len = pktin->length - pktin->savedpos;
6518 unsigned long num = GET_32BIT(p); /* what is it? */
6519 /* If it's 0, it hardly matters; assume string */
6523 int maybe_int = FALSE, maybe_str = FALSE;
6524 #define CHECK_HYPOTHESIS(offset, result) \
6527 if (q >= 0 && q+4 <= len) { \
6528 q = q + 4 + GET_32BIT(p+q); \
6529 if (q >= 0 && q+4 <= len && \
6530 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6534 CHECK_HYPOTHESIS(4+1, maybe_int);
6535 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6536 #undef CHECK_HYPOTHESIS
6537 if (maybe_int && !maybe_str)
6539 else if (!maybe_int && maybe_str)
6542 /* Crikey. Either or neither. Panic. */
6543 is_plausible = FALSE;
6546 ssh->exitcode = 128; /* means `unknown signal' */
6549 /* Old non-standard OpenSSH. */
6550 int signum = ssh_pkt_getuint32(pktin);
6551 fmt_sig = dupprintf(" %d", signum);
6552 ssh->exitcode = 128 + signum;
6554 /* As per the drafts. */
6557 ssh_pkt_getstring(pktin, &sig, &siglen);
6558 /* Signal name isn't supposed to be blank, but
6559 * let's cope gracefully if it is. */
6561 fmt_sig = dupprintf(" \"%.*s\"",
6566 * Really hideous method of translating the
6567 * signal description back into a locally
6568 * meaningful number.
6573 #define TRANSLATE_SIGNAL(s) \
6574 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
6575 ssh->exitcode = 128 + SIG ## s
6577 TRANSLATE_SIGNAL(ABRT);
6580 TRANSLATE_SIGNAL(ALRM);
6583 TRANSLATE_SIGNAL(FPE);
6586 TRANSLATE_SIGNAL(HUP);
6589 TRANSLATE_SIGNAL(ILL);
6592 TRANSLATE_SIGNAL(INT);
6595 TRANSLATE_SIGNAL(KILL);
6598 TRANSLATE_SIGNAL(PIPE);
6601 TRANSLATE_SIGNAL(QUIT);
6604 TRANSLATE_SIGNAL(SEGV);
6607 TRANSLATE_SIGNAL(TERM);
6610 TRANSLATE_SIGNAL(USR1);
6613 TRANSLATE_SIGNAL(USR2);
6615 #undef TRANSLATE_SIGNAL
6617 ssh->exitcode = 128;
6619 core = ssh2_pkt_getbool(pktin);
6620 ssh_pkt_getstring(pktin, &msg, &msglen);
6622 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6624 /* ignore lang tag */
6625 } /* else don't attempt to parse */
6626 logeventf(ssh, "Server exited on signal%s%s%s",
6627 fmt_sig, core ? " (core dumped)" : "",
6629 if (*fmt_sig) sfree(fmt_sig);
6630 if (*fmt_msg) sfree(fmt_msg);
6631 reply = SSH2_MSG_CHANNEL_SUCCESS;
6636 * This is a channel request we don't know
6637 * about, so we now either ignore the request
6638 * or respond with CHANNEL_FAILURE, depending
6641 reply = SSH2_MSG_CHANNEL_FAILURE;
6644 pktout = ssh2_pkt_init(reply);
6645 ssh2_pkt_adduint32(pktout, c->remoteid);
6646 ssh2_pkt_send(ssh, pktout);
6650 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6653 int typelen, want_reply;
6654 struct Packet *pktout;
6656 ssh_pkt_getstring(pktin, &type, &typelen);
6657 want_reply = ssh2_pkt_getbool(pktin);
6660 * We currently don't support any global requests
6661 * at all, so we either ignore the request or
6662 * respond with REQUEST_FAILURE, depending on
6666 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6667 ssh2_pkt_send(ssh, pktout);
6671 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6679 struct ssh_channel *c;
6680 unsigned remid, winsize, pktsize;
6681 struct Packet *pktout;
6683 ssh_pkt_getstring(pktin, &type, &typelen);
6684 c = snew(struct ssh_channel);
6687 remid = ssh_pkt_getuint32(pktin);
6688 winsize = ssh_pkt_getuint32(pktin);
6689 pktsize = ssh_pkt_getuint32(pktin);
6691 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6694 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6695 addrstr = snewn(peeraddrlen+1, char);
6696 memcpy(addrstr, peeraddr, peeraddrlen);
6697 addrstr[peeraddrlen] = '\0';
6698 peerport = ssh_pkt_getuint32(pktin);
6700 logeventf(ssh, "Received X11 connect request from %s:%d",
6703 if (!ssh->X11_fwd_enabled)
6704 error = "X11 forwarding is not enabled";
6705 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6706 ssh->x11auth, addrstr, peerport,
6707 &ssh->cfg) != NULL) {
6708 error = "Unable to open an X11 connection";
6710 logevent("Opening X11 forward connection succeeded");
6715 } else if (typelen == 15 &&
6716 !memcmp(type, "forwarded-tcpip", 15)) {
6717 struct ssh_rportfwd pf, *realpf;
6720 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6721 pf.sport = ssh_pkt_getuint32(pktin);
6722 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6723 peerport = ssh_pkt_getuint32(pktin);
6724 realpf = find234(ssh->rportfwds, &pf, NULL);
6725 logeventf(ssh, "Received remote port %d open request "
6726 "from %s:%d", pf.sport, peeraddr, peerport);
6727 if (realpf == NULL) {
6728 error = "Remote port is not recognised";
6730 const char *e = pfd_newconnect(&c->u.pfd.s,
6734 realpf->pfrec->addressfamily);
6735 logeventf(ssh, "Attempting to forward remote port to "
6736 "%s:%d", realpf->dhost, realpf->dport);
6738 logeventf(ssh, "Port open failed: %s", e);
6739 error = "Port open failed";
6741 logevent("Forwarded port opened successfully");
6742 c->type = CHAN_SOCKDATA;
6745 } else if (typelen == 22 &&
6746 !memcmp(type, "auth-agent@openssh.com", 22)) {
6747 if (!ssh->agentfwd_enabled)
6748 error = "Agent forwarding is not enabled";
6750 c->type = CHAN_AGENT; /* identify channel type */
6751 c->u.a.lensofar = 0;
6754 error = "Unsupported channel type requested";
6757 c->remoteid = remid;
6758 c->halfopen = FALSE;
6760 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6761 ssh2_pkt_adduint32(pktout, c->remoteid);
6762 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6763 ssh2_pkt_addstring(pktout, error);
6764 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6765 ssh2_pkt_send(ssh, pktout);
6766 logeventf(ssh, "Rejected channel open: %s", error);
6769 c->localid = alloc_channel_id(ssh);
6771 c->v.v2.locwindow = c->v.v2.locmaxwin = OUR_V2_WINSIZE;
6772 c->v.v2.remwindow = winsize;
6773 c->v.v2.remmaxpkt = pktsize;
6774 bufchain_init(&c->v.v2.outbuffer);
6775 add234(ssh->channels, c);
6776 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6777 ssh2_pkt_adduint32(pktout, c->remoteid);
6778 ssh2_pkt_adduint32(pktout, c->localid);
6779 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6780 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6781 ssh2_pkt_send(ssh, pktout);
6786 * Buffer banner messages for later display at some convenient point.
6788 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6790 /* Arbitrary limit to prevent unbounded inflation of buffer */
6791 if (bufchain_size(&ssh->banner) <= 131072) {
6792 char *banner = NULL;
6794 ssh_pkt_getstring(pktin, &banner, &size);
6796 bufchain_add(&ssh->banner, banner, size);
6800 /* Helper function to deal with sending tty modes for "pty-req" */
6801 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6803 struct Packet *pktout = (struct Packet *)data;
6805 unsigned int arg = 0;
6806 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6807 if (i == lenof(ssh_ttymodes)) return;
6808 switch (ssh_ttymodes[i].type) {
6810 arg = ssh_tty_parse_specchar(val);
6813 arg = ssh_tty_parse_boolean(val);
6816 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6817 ssh2_pkt_adduint32(pktout, arg);
6821 * Handle the SSH-2 userauth and connection layers.
6823 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6824 struct Packet *pktin)
6826 struct do_ssh2_authconn_state {
6829 AUTH_TYPE_PUBLICKEY,
6830 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6831 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6833 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6834 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6836 int done_service_req;
6837 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6838 int tried_pubkey_config, done_agent;
6839 int kbd_inter_refused;
6841 prompts_t *cur_prompt;
6846 void *publickey_blob;
6847 int publickey_bloblen;
6848 int publickey_encrypted;
6849 char *publickey_algorithm;
6850 char *publickey_comment;
6851 unsigned char agent_request[5], *agent_response, *agentp;
6852 int agent_responselen;
6853 unsigned char *pkblob_in_agent;
6855 char *pkblob, *alg, *commentp;
6856 int pklen, alglen, commentlen;
6857 int siglen, retlen, len;
6858 char *q, *agentreq, *ret;
6860 int num_env, env_left, env_ok;
6861 struct Packet *pktout;
6863 crState(do_ssh2_authconn_state);
6865 crBegin(ssh->do_ssh2_authconn_crstate);
6867 s->done_service_req = FALSE;
6868 s->we_are_in = FALSE;
6869 if (!ssh->cfg.ssh_no_userauth) {
6871 * Request userauth protocol, and await a response to it.
6873 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6874 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6875 ssh2_pkt_send(ssh, s->pktout);
6876 crWaitUntilV(pktin);
6877 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6878 s->done_service_req = TRUE;
6880 if (!s->done_service_req) {
6882 * Request connection protocol directly, without authentication.
6884 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6885 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6886 ssh2_pkt_send(ssh, s->pktout);
6887 crWaitUntilV(pktin);
6888 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6889 s->we_are_in = TRUE; /* no auth required */
6891 bombout(("Server refused service request"));
6896 /* Arrange to be able to deal with any BANNERs that come in.
6897 * (We do this now as packets may come in during the next bit.) */
6898 bufchain_init(&ssh->banner);
6899 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6900 ssh2_msg_userauth_banner;
6903 * Misc one-time setup for authentication.
6905 s->publickey_blob = NULL;
6906 if (!s->we_are_in) {
6909 * Load the public half of any configured public key file
6912 if (!filename_is_null(ssh->cfg.keyfile)) {
6914 logeventf(ssh, "Reading private key file \"%.150s\"",
6915 filename_to_str(&ssh->cfg.keyfile));
6916 keytype = key_type(&ssh->cfg.keyfile);
6917 if (keytype == SSH_KEYTYPE_SSH2) {
6920 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6921 &s->publickey_algorithm,
6922 &s->publickey_bloblen,
6923 &s->publickey_comment, &error);
6924 if (s->publickey_blob) {
6925 s->publickey_encrypted =
6926 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
6929 logeventf(ssh, "Unable to load private key (%s)",
6931 msgbuf = dupprintf("Unable to load private key file "
6932 "\"%.150s\" (%s)\r\n",
6933 filename_to_str(&ssh->cfg.keyfile),
6935 c_write_str(ssh, msgbuf);
6940 logeventf(ssh, "Unable to use this key file (%s)",
6941 key_type_to_str(keytype));
6942 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6944 filename_to_str(&ssh->cfg.keyfile),
6945 key_type_to_str(keytype));
6946 c_write_str(ssh, msgbuf);
6948 s->publickey_blob = NULL;
6953 * Find out about any keys Pageant has (but if there's a
6954 * public key configured, filter out all others).
6957 s->agent_response = NULL;
6958 s->pkblob_in_agent = NULL;
6959 if (ssh->cfg.tryagent && agent_exists()) {
6963 logevent("Pageant is running. Requesting keys.");
6965 /* Request the keys held by the agent. */
6966 PUT_32BIT(s->agent_request, 1);
6967 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6968 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
6969 ssh_agent_callback, ssh)) {
6973 bombout(("Unexpected data from server while"
6974 " waiting for agent response"));
6977 } while (pktin || inlen > 0);
6978 r = ssh->agent_response;
6979 s->agent_responselen = ssh->agent_response_len;
6981 s->agent_response = (unsigned char *) r;
6982 if (s->agent_response && s->agent_responselen >= 5 &&
6983 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6986 p = s->agent_response + 5;
6987 s->nkeys = GET_32BIT(p);
6989 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6990 if (s->publickey_blob) {
6991 /* See if configured key is in agent. */
6992 for (keyi = 0; keyi < s->nkeys; keyi++) {
6993 s->pklen = GET_32BIT(p);
6994 if (s->pklen == s->publickey_bloblen &&
6995 !memcmp(p+4, s->publickey_blob,
6996 s->publickey_bloblen)) {
6997 logeventf(ssh, "Pageant key #%d matches "
6998 "configured key file", keyi);
7000 s->pkblob_in_agent = p;
7004 p += GET_32BIT(p) + 4; /* comment */
7006 if (!s->pkblob_in_agent) {
7007 logevent("Configured key file not in Pageant");
7017 * We repeat this whole loop, including the username prompt,
7018 * until we manage a successful authentication. If the user
7019 * types the wrong _password_, they can be sent back to the
7020 * beginning to try another username, if this is configured on.
7021 * (If they specify a username in the config, they are never
7022 * asked, even if they do give a wrong password.)
7024 * I think this best serves the needs of
7026 * - the people who have no configuration, no keys, and just
7027 * want to try repeated (username,password) pairs until they
7028 * type both correctly
7030 * - people who have keys and configuration but occasionally
7031 * need to fall back to passwords
7033 * - people with a key held in Pageant, who might not have
7034 * logged in to a particular machine before; so they want to
7035 * type a username, and then _either_ their key will be
7036 * accepted, _or_ they will type a password. If they mistype
7037 * the username they will want to be able to get back and
7040 s->username[0] = '\0';
7041 s->got_username = FALSE;
7042 while (!s->we_are_in) {
7046 if (s->got_username && !ssh->cfg.change_username) {
7048 * We got a username last time round this loop, and
7049 * with change_username turned off we don't try to get
7052 } else if (!*ssh->cfg.username) {
7053 int ret; /* need not be kept over crReturn */
7054 s->cur_prompt = new_prompts(ssh->frontend);
7055 s->cur_prompt->to_server = TRUE;
7056 s->cur_prompt->name = dupstr("SSH login name");
7057 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
7058 lenof(s->username));
7059 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7062 crWaitUntilV(!pktin);
7063 ret = get_userpass_input(s->cur_prompt, in, inlen);
7068 * get_userpass_input() failed to get a username.
7071 free_prompts(s->cur_prompt);
7072 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7075 memcpy(s->username, s->cur_prompt->prompts[0]->result,
7076 lenof(s->username));
7077 free_prompts(s->cur_prompt);
7080 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
7081 s->username[sizeof(s->username)-1] = '\0';
7082 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7083 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
7084 c_write_str(ssh, stuff);
7088 s->got_username = TRUE;
7091 * Send an authentication request using method "none": (a)
7092 * just in case it succeeds, and (b) so that we know what
7093 * authentication methods we can usefully try next.
7095 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7097 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7098 ssh2_pkt_addstring(s->pktout, s->username);
7099 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7100 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7101 ssh2_pkt_send(ssh, s->pktout);
7102 s->type = AUTH_TYPE_NONE;
7104 s->we_are_in = FALSE;
7106 s->tried_pubkey_config = FALSE;
7107 s->kbd_inter_refused = FALSE;
7109 /* Reset agent request state. */
7110 s->done_agent = FALSE;
7111 if (s->agent_response) {
7112 if (s->pkblob_in_agent) {
7113 s->agentp = s->pkblob_in_agent;
7115 s->agentp = s->agent_response + 5 + 4;
7122 * Wait for the result of the last authentication request.
7125 crWaitUntilV(pktin);
7127 * Now is a convenient point to spew any banner material
7128 * that we've accumulated. (This should ensure that when
7129 * we exit the auth loop, we haven't any left to deal
7133 int size = bufchain_size(&ssh->banner);
7135 * Don't show the banner if we're operating in
7136 * non-verbose non-interactive mode. (It's probably
7137 * a script, which means nobody will read the
7138 * banner _anyway_, and moreover the printing of
7139 * the banner will screw up processing on the
7140 * output of (say) plink.)
7142 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7143 char *banner = snewn(size, char);
7144 bufchain_fetch(&ssh->banner, banner, size);
7145 c_write_untrusted(ssh, banner, size);
7148 bufchain_clear(&ssh->banner);
7150 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
7151 logevent("Access granted");
7152 s->we_are_in = TRUE;
7156 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
7157 bombout(("Strange packet received during authentication: "
7158 "type %d", pktin->type));
7165 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7166 * we can look at the string in it and know what we can
7167 * helpfully try next.
7169 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
7172 ssh_pkt_getstring(pktin, &methods, &methlen);
7173 if (!ssh2_pkt_getbool(pktin)) {
7175 * We have received an unequivocal Access
7176 * Denied. This can translate to a variety of
7179 * - if we'd just tried "none" authentication,
7180 * it's not worth printing anything at all
7182 * - if we'd just tried a public key _offer_,
7183 * the message should be "Server refused our
7184 * key" (or no message at all if the key
7185 * came from Pageant)
7187 * - if we'd just tried anything else, the
7188 * message really should be "Access denied".
7190 * Additionally, if we'd just tried password
7191 * authentication, we should break out of this
7192 * whole loop so as to go back to the username
7193 * prompt (iff we're configured to allow
7194 * username change attempts).
7196 if (s->type == AUTH_TYPE_NONE) {
7198 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7199 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7200 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7201 c_write_str(ssh, "Server refused our key\r\n");
7202 logevent("Server refused public key");
7203 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
7204 /* server declined keyboard-interactive; ignore */
7206 c_write_str(ssh, "Access denied\r\n");
7207 logevent("Access denied");
7208 if (s->type == AUTH_TYPE_PASSWORD &&
7209 ssh->cfg.change_username) {
7210 /* XXX perhaps we should allow
7211 * keyboard-interactive to do this too? */
7212 s->we_are_in = FALSE;
7217 c_write_str(ssh, "Further authentication required\r\n");
7218 logevent("Further authentication required");
7222 in_commasep_string("publickey", methods, methlen);
7224 in_commasep_string("password", methods, methlen);
7225 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
7226 in_commasep_string("keyboard-interactive", methods, methlen);
7229 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7231 if (s->can_pubkey && !s->done_agent && s->nkeys) {
7234 * Attempt public-key authentication using a key from Pageant.
7237 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7239 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7241 /* Unpack key from agent response */
7242 s->pklen = GET_32BIT(s->agentp);
7244 s->pkblob = (char *)s->agentp;
7245 s->agentp += s->pklen;
7246 s->alglen = GET_32BIT(s->pkblob);
7247 s->alg = s->pkblob + 4;
7248 s->commentlen = GET_32BIT(s->agentp);
7250 s->commentp = (char *)s->agentp;
7251 s->agentp += s->commentlen;
7252 /* s->agentp now points at next key, if any */
7254 /* See if server will accept it */
7255 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7256 ssh2_pkt_addstring(s->pktout, s->username);
7257 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7258 /* service requested */
7259 ssh2_pkt_addstring(s->pktout, "publickey");
7261 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7262 ssh2_pkt_addstring_start(s->pktout);
7263 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7264 ssh2_pkt_addstring_start(s->pktout);
7265 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7266 ssh2_pkt_send(ssh, s->pktout);
7267 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
7269 crWaitUntilV(pktin);
7270 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7272 /* Offer of key refused. */
7279 if (flags & FLAG_VERBOSE) {
7280 c_write_str(ssh, "Authenticating with "
7282 c_write(ssh, s->commentp, s->commentlen);
7283 c_write_str(ssh, "\" from agent\r\n");
7287 * Server is willing to accept the key.
7288 * Construct a SIGN_REQUEST.
7290 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7291 ssh2_pkt_addstring(s->pktout, s->username);
7292 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7293 /* service requested */
7294 ssh2_pkt_addstring(s->pktout, "publickey");
7296 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7297 ssh2_pkt_addstring_start(s->pktout);
7298 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7299 ssh2_pkt_addstring_start(s->pktout);
7300 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7302 /* Ask agent for signature. */
7303 s->siglen = s->pktout->length - 5 + 4 +
7304 ssh->v2_session_id_len;
7305 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7307 s->len = 1; /* message type */
7308 s->len += 4 + s->pklen; /* key blob */
7309 s->len += 4 + s->siglen; /* data to sign */
7310 s->len += 4; /* flags */
7311 s->agentreq = snewn(4 + s->len, char);
7312 PUT_32BIT(s->agentreq, s->len);
7313 s->q = s->agentreq + 4;
7314 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
7315 PUT_32BIT(s->q, s->pklen);
7317 memcpy(s->q, s->pkblob, s->pklen);
7319 PUT_32BIT(s->q, s->siglen);
7321 /* Now the data to be signed... */
7322 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7323 PUT_32BIT(s->q, ssh->v2_session_id_len);
7326 memcpy(s->q, ssh->v2_session_id,
7327 ssh->v2_session_id_len);
7328 s->q += ssh->v2_session_id_len;
7329 memcpy(s->q, s->pktout->data + 5,
7330 s->pktout->length - 5);
7331 s->q += s->pktout->length - 5;
7332 /* And finally the (zero) flags word. */
7334 if (!agent_query(s->agentreq, s->len + 4,
7336 ssh_agent_callback, ssh)) {
7340 bombout(("Unexpected data from server"
7341 " while waiting for agent"
7345 } while (pktin || inlen > 0);
7346 vret = ssh->agent_response;
7347 s->retlen = ssh->agent_response_len;
7352 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
7353 logevent("Sending Pageant's response");
7354 ssh2_add_sigblob(ssh, s->pktout,
7355 s->pkblob, s->pklen,
7357 GET_32BIT(s->ret + 5));
7358 ssh2_pkt_send(ssh, s->pktout);
7359 s->type = AUTH_TYPE_PUBLICKEY;
7361 /* FIXME: less drastic response */
7362 bombout(("Pageant failed to answer challenge"));
7368 /* Do we have any keys left to try? */
7369 if (s->pkblob_in_agent) {
7370 s->done_agent = TRUE;
7371 s->tried_pubkey_config = TRUE;
7374 if (s->keyi >= s->nkeys)
7375 s->done_agent = TRUE;
7378 } else if (s->can_pubkey && s->publickey_blob &&
7379 !s->tried_pubkey_config) {
7381 struct ssh2_userkey *key; /* not live over crReturn */
7382 char *passphrase; /* not live over crReturn */
7384 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7386 s->tried_pubkey_config = TRUE;
7389 * Try the public key supplied in the configuration.
7391 * First, offer the public blob to see if the server is
7392 * willing to accept it.
7394 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7395 ssh2_pkt_addstring(s->pktout, s->username);
7396 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7397 /* service requested */
7398 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7399 ssh2_pkt_addbool(s->pktout, FALSE);
7400 /* no signature included */
7401 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7402 ssh2_pkt_addstring_start(s->pktout);
7403 ssh2_pkt_addstring_data(s->pktout,
7404 (char *)s->publickey_blob,
7405 s->publickey_bloblen);
7406 ssh2_pkt_send(ssh, s->pktout);
7407 logevent("Offered public key");
7409 crWaitUntilV(pktin);
7410 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7411 /* Key refused. Give up. */
7412 s->gotit = TRUE; /* reconsider message next loop */
7413 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7414 continue; /* process this new message */
7416 logevent("Offer of public key accepted");
7419 * Actually attempt a serious authentication using
7422 if (flags & FLAG_VERBOSE) {
7423 c_write_str(ssh, "Authenticating with public key \"");
7424 c_write_str(ssh, s->publickey_comment);
7425 c_write_str(ssh, "\"\r\n");
7429 const char *error; /* not live over crReturn */
7430 if (s->publickey_encrypted) {
7432 * Get a passphrase from the user.
7434 int ret; /* need not be kept over crReturn */
7435 s->cur_prompt = new_prompts(ssh->frontend);
7436 s->cur_prompt->to_server = FALSE;
7437 s->cur_prompt->name = dupstr("SSH key passphrase");
7438 add_prompt(s->cur_prompt,
7439 dupprintf("Passphrase for key \"%.100s\": ",
7440 s->publickey_comment),
7441 FALSE, SSH_MAX_PASSWORD_LEN);
7442 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7445 crWaitUntilV(!pktin);
7446 ret = get_userpass_input(s->cur_prompt,
7451 /* Failed to get a passphrase. Terminate. */
7452 free_prompts(s->cur_prompt);
7453 ssh_disconnect(ssh, NULL,
7454 "Unable to authenticate",
7455 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7460 dupstr(s->cur_prompt->prompts[0]->result);
7461 free_prompts(s->cur_prompt);
7463 passphrase = NULL; /* no passphrase needed */
7467 * Try decrypting the key.
7469 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7472 /* burn the evidence */
7473 memset(passphrase, 0, strlen(passphrase));
7476 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7478 (key == SSH2_WRONG_PASSPHRASE)) {
7479 c_write_str(ssh, "Wrong passphrase\r\n");
7481 /* and loop again */
7483 c_write_str(ssh, "Unable to load private key (");
7484 c_write_str(ssh, error);
7485 c_write_str(ssh, ")\r\n");
7487 break; /* try something else */
7493 unsigned char *pkblob, *sigblob, *sigdata;
7494 int pkblob_len, sigblob_len, sigdata_len;
7498 * We have loaded the private key and the server
7499 * has announced that it's willing to accept it.
7500 * Hallelujah. Generate a signature and send it.
7502 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7503 ssh2_pkt_addstring(s->pktout, s->username);
7504 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7505 /* service requested */
7506 ssh2_pkt_addstring(s->pktout, "publickey");
7508 ssh2_pkt_addbool(s->pktout, TRUE);
7509 /* signature follows */
7510 ssh2_pkt_addstring(s->pktout, key->alg->name);
7511 pkblob = key->alg->public_blob(key->data,
7513 ssh2_pkt_addstring_start(s->pktout);
7514 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
7518 * The data to be signed is:
7522 * followed by everything so far placed in the
7525 sigdata_len = s->pktout->length - 5 + 4 +
7526 ssh->v2_session_id_len;
7527 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7529 sigdata = snewn(sigdata_len, unsigned char);
7531 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7532 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7535 memcpy(sigdata+p, ssh->v2_session_id,
7536 ssh->v2_session_id_len);
7537 p += ssh->v2_session_id_len;
7538 memcpy(sigdata+p, s->pktout->data + 5,
7539 s->pktout->length - 5);
7540 p += s->pktout->length - 5;
7541 assert(p == sigdata_len);
7542 sigblob = key->alg->sign(key->data, (char *)sigdata,
7543 sigdata_len, &sigblob_len);
7544 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7545 sigblob, sigblob_len);
7550 ssh2_pkt_send(ssh, s->pktout);
7551 s->type = AUTH_TYPE_PUBLICKEY;
7552 key->alg->freekey(key->data);
7555 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
7558 * Keyboard-interactive authentication.
7561 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7563 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
7565 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7566 ssh2_pkt_addstring(s->pktout, s->username);
7567 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7568 /* service requested */
7569 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
7571 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7572 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
7573 ssh2_pkt_send(ssh, s->pktout);
7575 crWaitUntilV(pktin);
7576 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7577 /* Server is not willing to do keyboard-interactive
7578 * at all (or, bizarrely but legally, accepts the
7579 * user without actually issuing any prompts).
7580 * Give up on it entirely. */
7582 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7583 logevent("Keyboard-interactive authentication refused");
7584 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7585 s->kbd_inter_refused = TRUE; /* don't try it again */
7590 * Loop while the server continues to send INFO_REQUESTs.
7592 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
7594 char *name, *inst, *lang;
7595 int name_len, inst_len, lang_len;
7599 * We've got a fresh USERAUTH_INFO_REQUEST.
7600 * Get the preamble and start building a prompt.
7602 ssh_pkt_getstring(pktin, &name, &name_len);
7603 ssh_pkt_getstring(pktin, &inst, &inst_len);
7604 ssh_pkt_getstring(pktin, &lang, &lang_len);
7605 s->cur_prompt = new_prompts(ssh->frontend);
7606 s->cur_prompt->to_server = TRUE;
7608 /* FIXME: better prefix to distinguish from
7610 s->cur_prompt->name =
7611 dupprintf("SSH server: %.*s", name_len, name);
7612 s->cur_prompt->name_reqd = TRUE;
7614 s->cur_prompt->name =
7615 dupstr("SSH server authentication");
7616 s->cur_prompt->name_reqd = FALSE;
7618 /* FIXME: ugly to print "Using..." in prompt _every_
7619 * time round. Can this be done more subtly? */
7620 s->cur_prompt->instruction =
7621 dupprintf("Using keyboard-interactive authentication.%s%.*s",
7622 inst_len ? "\n" : "", inst_len, inst);
7623 s->cur_prompt->instr_reqd = TRUE;
7626 * Get the prompts from the packet.
7628 s->num_prompts = ssh_pkt_getuint32(pktin);
7629 for (i = 0; i < s->num_prompts; i++) {
7633 static char noprompt[] =
7634 "<server failed to send prompt>: ";
7636 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7637 echo = ssh2_pkt_getbool(pktin);
7640 prompt_len = lenof(noprompt)-1;
7642 add_prompt(s->cur_prompt,
7643 dupprintf("%.*s", prompt_len, prompt),
7644 echo, SSH_MAX_PASSWORD_LEN);
7648 * Get the user's responses.
7650 if (s->num_prompts) {
7651 int ret; /* not live over crReturn */
7652 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7655 crWaitUntilV(!pktin);
7656 ret = get_userpass_input(s->cur_prompt, in, inlen);
7661 * Failed to get responses. Terminate.
7663 free_prompts(s->cur_prompt);
7664 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7665 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7672 * Send the responses to the server.
7674 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7675 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7676 for (i=0; i < s->num_prompts; i++) {
7677 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7678 ssh2_pkt_addstring(s->pktout,
7679 s->cur_prompt->prompts[i]->result);
7680 end_log_omission(ssh, s->pktout);
7682 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
7685 * Get the next packet in case it's another
7688 crWaitUntilV(pktin);
7693 * We should have SUCCESS or FAILURE now.
7697 } else if (s->can_passwd) {
7700 * Plain old password authentication.
7702 int ret; /* not live over crReturn */
7703 int changereq_first_time; /* not live over crReturn */
7705 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
7707 s->cur_prompt = new_prompts(ssh->frontend);
7708 s->cur_prompt->to_server = TRUE;
7709 s->cur_prompt->name = dupstr("SSH password");
7710 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
7713 FALSE, SSH_MAX_PASSWORD_LEN);
7715 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7718 crWaitUntilV(!pktin);
7719 ret = get_userpass_input(s->cur_prompt, in, inlen);
7724 * Failed to get responses. Terminate.
7726 free_prompts(s->cur_prompt);
7727 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7728 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7733 * Squirrel away the password. (We may need it later if
7734 * asked to change it.)
7736 s->password = dupstr(s->cur_prompt->prompts[0]->result);
7737 free_prompts(s->cur_prompt);
7740 * Send the password packet.
7742 * We pad out the password packet to 256 bytes to make
7743 * it harder for an attacker to find the length of the
7746 * Anyone using a password longer than 256 bytes
7747 * probably doesn't have much to worry about from
7748 * people who find out how long their password is!
7750 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7751 ssh2_pkt_addstring(s->pktout, s->username);
7752 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7753 /* service requested */
7754 ssh2_pkt_addstring(s->pktout, "password");
7755 ssh2_pkt_addbool(s->pktout, FALSE);
7756 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7757 ssh2_pkt_addstring(s->pktout, s->password);
7758 end_log_omission(ssh, s->pktout);
7759 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
7760 logevent("Sent password");
7761 s->type = AUTH_TYPE_PASSWORD;
7764 * Wait for next packet, in case it's a password change
7767 crWaitUntilV(pktin);
7768 changereq_first_time = TRUE;
7770 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
7773 * We're being asked for a new password
7774 * (perhaps not for the first time).
7775 * Loop until the server accepts it.
7778 int got_new = FALSE; /* not live over crReturn */
7779 char *prompt; /* not live over crReturn */
7780 int prompt_len; /* not live over crReturn */
7784 if (changereq_first_time)
7785 msg = "Server requested password change";
7787 msg = "Server rejected new password";
7789 c_write_str(ssh, msg);
7790 c_write_str(ssh, "\r\n");
7793 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7795 s->cur_prompt = new_prompts(ssh->frontend);
7796 s->cur_prompt->to_server = TRUE;
7797 s->cur_prompt->name = dupstr("New SSH password");
7798 s->cur_prompt->instruction =
7799 dupprintf("%.*s", prompt_len, prompt);
7800 s->cur_prompt->instr_reqd = TRUE;
7802 * There's no explicit requirement in the protocol
7803 * for the "old" passwords in the original and
7804 * password-change messages to be the same, and
7805 * apparently some Cisco kit supports password change
7806 * by the user entering a blank password originally
7807 * and the real password subsequently, so,
7808 * reluctantly, we prompt for the old password again.
7810 * (On the other hand, some servers don't even bother
7811 * to check this field.)
7813 add_prompt(s->cur_prompt,
7814 dupstr("Current password (blank for previously entered password): "),
7815 FALSE, SSH_MAX_PASSWORD_LEN);
7816 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
7817 FALSE, SSH_MAX_PASSWORD_LEN);
7818 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
7819 FALSE, SSH_MAX_PASSWORD_LEN);
7822 * Loop until the user manages to enter the same
7827 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7830 crWaitUntilV(!pktin);
7831 ret = get_userpass_input(s->cur_prompt, in, inlen);
7836 * Failed to get responses. Terminate.
7838 /* burn the evidence */
7839 free_prompts(s->cur_prompt);
7840 memset(s->password, 0, strlen(s->password));
7842 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7843 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7849 * If the user specified a new original password
7850 * (IYSWIM), overwrite any previously specified
7852 * (A side effect is that the user doesn't have to
7853 * re-enter it if they louse up the new password.)
7855 if (s->cur_prompt->prompts[0]->result[0]) {
7856 memset(s->password, 0, strlen(s->password));
7857 /* burn the evidence */
7860 dupstr(s->cur_prompt->prompts[0]->result);
7864 * Check the two new passwords match.
7866 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
7867 s->cur_prompt->prompts[2]->result)
7870 /* They don't. Silly user. */
7871 c_write_str(ssh, "Passwords do not match\r\n");
7876 * Send the new password (along with the old one).
7877 * (see above for padding rationale)
7879 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7880 ssh2_pkt_addstring(s->pktout, s->username);
7881 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7882 /* service requested */
7883 ssh2_pkt_addstring(s->pktout, "password");
7884 ssh2_pkt_addbool(s->pktout, TRUE);
7885 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7886 ssh2_pkt_addstring(s->pktout, s->password);
7887 ssh2_pkt_addstring(s->pktout,
7888 s->cur_prompt->prompts[1]->result);
7889 free_prompts(s->cur_prompt);
7890 end_log_omission(ssh, s->pktout);
7891 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
7892 logevent("Sent new password");
7895 * Now see what the server has to say about it.
7896 * (If it's CHANGEREQ again, it's not happy with the
7899 crWaitUntilV(pktin);
7900 changereq_first_time = FALSE;
7905 * We need to reexamine the current pktin at the top
7906 * of the loop. Either:
7907 * - we weren't asked to change password at all, in
7908 * which case it's a SUCCESS or FAILURE with the
7910 * - we sent a new password, and the server was
7911 * either OK with it (SUCCESS or FAILURE w/partial
7912 * success) or unhappy with the _old_ password
7913 * (FAILURE w/o partial success)
7914 * In any of these cases, we go back to the top of
7915 * the loop and start again.
7920 * We don't need the old password any more, in any
7921 * case. Burn the evidence.
7923 memset(s->password, 0, strlen(s->password));
7928 ssh_disconnect(ssh, NULL,
7929 "No supported authentication methods available",
7930 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7938 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7940 /* Clear up various bits and pieces from authentication. */
7941 if (s->publickey_blob) {
7942 sfree(s->publickey_blob);
7943 sfree(s->publickey_comment);
7945 if (s->agent_response)
7946 sfree(s->agent_response);
7949 * Now the connection protocol has started, one way or another.
7952 ssh->channels = newtree234(ssh_channelcmp);
7955 * Set up handlers for some connection protocol messages, so we
7956 * don't have to handle them repeatedly in this coroutine.
7958 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7959 ssh2_msg_channel_window_adjust;
7960 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7961 ssh2_msg_global_request;
7964 * Create the main session channel.
7966 if (ssh->cfg.ssh_no_shell) {
7967 ssh->mainchan = NULL;
7968 } else if (*ssh->cfg.ssh_nc_host) {
7970 * Just start a direct-tcpip channel and use it as the main
7973 ssh->mainchan = snew(struct ssh_channel);
7974 ssh->mainchan->ssh = ssh;
7975 ssh->mainchan->localid = alloc_channel_id(ssh);
7977 "Opening direct-tcpip channel to %s:%d in place of session",
7978 ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port);
7979 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7980 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
7981 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7982 ssh->mainchan->v.v2.locwindow = ssh->mainchan->v.v2.locmaxwin =
7983 ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
7984 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7985 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7986 ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host);
7987 ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port);
7989 * There's nothing meaningful to put in the originator
7990 * fields, but some servers insist on syntactically correct
7993 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
7994 ssh2_pkt_adduint32(s->pktout, 0);
7995 ssh2_pkt_send(ssh, s->pktout);
7997 crWaitUntilV(pktin);
7998 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7999 bombout(("Server refused to open a direct-tcpip channel"));
8001 /* FIXME: error data comes back in FAILURE packet */
8003 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8004 bombout(("Server's channel confirmation cited wrong channel"));
8007 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8008 ssh->mainchan->halfopen = FALSE;
8009 ssh->mainchan->type = CHAN_MAINSESSION;
8010 ssh->mainchan->closes = 0;
8011 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8012 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8013 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
8014 add234(ssh->channels, ssh->mainchan);
8015 update_specials_menu(ssh->frontend);
8016 logevent("Opened direct-tcpip channel");
8019 ssh->mainchan = snew(struct ssh_channel);
8020 ssh->mainchan->ssh = ssh;
8021 ssh->mainchan->localid = alloc_channel_id(ssh);
8022 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8023 ssh2_pkt_addstring(s->pktout, "session");
8024 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
8025 ssh->mainchan->v.v2.locwindow = ssh->mainchan->v.v2.locmaxwin =
8026 ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
8027 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8028 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8029 ssh2_pkt_send(ssh, s->pktout);
8030 crWaitUntilV(pktin);
8031 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8032 bombout(("Server refused to open a session"));
8034 /* FIXME: error data comes back in FAILURE packet */
8036 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8037 bombout(("Server's channel confirmation cited wrong channel"));
8040 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8041 ssh->mainchan->halfopen = FALSE;
8042 ssh->mainchan->type = CHAN_MAINSESSION;
8043 ssh->mainchan->closes = 0;
8044 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8045 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8046 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
8047 add234(ssh->channels, ssh->mainchan);
8048 update_specials_menu(ssh->frontend);
8049 logevent("Opened channel for session");
8050 ssh->ncmode = FALSE;
8054 * Now we have a channel, make dispatch table entries for
8055 * general channel-based messages.
8057 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8058 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8059 ssh2_msg_channel_data;
8060 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8061 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8062 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8063 ssh2_msg_channel_open_confirmation;
8064 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8065 ssh2_msg_channel_open_failure;
8066 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8067 ssh2_msg_channel_request;
8068 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8069 ssh2_msg_channel_open;
8071 if (ssh->cfg.ssh_simple) {
8073 * This message indicates to the server that we promise
8074 * not to try to run any other channel in parallel with
8075 * this one, so it's safe for it to advertise a very large
8076 * window and leave the flow control to TCP.
8078 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8079 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8080 ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
8081 ssh2_pkt_addbool(s->pktout, 0); /* no reply */
8082 ssh2_pkt_send(ssh, s->pktout);
8086 * Potentially enable X11 forwarding.
8088 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward) {
8089 char proto[20], data[64];
8090 logevent("Requesting X11 forwarding");
8091 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
8092 data, sizeof(data), ssh->cfg.x11_auth);
8093 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
8094 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8095 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8096 ssh2_pkt_addstring(s->pktout, "x11-req");
8097 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8098 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8099 ssh2_pkt_addstring(s->pktout, proto);
8101 * Note that while we blank the X authentication data here, we don't
8102 * take any special action to blank the start of an X11 channel,
8103 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
8104 * without having session blanking enabled is likely to leak your
8105 * cookie into the log.
8107 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8108 ssh2_pkt_addstring(s->pktout, data);
8109 end_log_omission(ssh, s->pktout);
8110 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
8111 ssh2_pkt_send(ssh, s->pktout);
8113 crWaitUntilV(pktin);
8115 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8116 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8117 bombout(("Unexpected response to X11 forwarding request:"
8118 " packet type %d", pktin->type));
8121 logevent("X11 forwarding refused");
8123 logevent("X11 forwarding enabled");
8124 ssh->X11_fwd_enabled = TRUE;
8129 * Enable port forwardings.
8131 ssh_setup_portfwd(ssh, &ssh->cfg);
8134 * Potentially enable agent forwarding.
8136 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) {
8137 logevent("Requesting OpenSSH-style agent forwarding");
8138 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8139 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8140 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
8141 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8142 ssh2_pkt_send(ssh, s->pktout);
8144 crWaitUntilV(pktin);
8146 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8147 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8148 bombout(("Unexpected response to agent forwarding request:"
8149 " packet type %d", pktin->type));
8152 logevent("Agent forwarding refused");
8154 logevent("Agent forwarding enabled");
8155 ssh->agentfwd_enabled = TRUE;
8160 * Now allocate a pty for the session.
8162 if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) {
8163 /* Unpick the terminal-speed string. */
8164 /* XXX perhaps we should allow no speeds to be sent. */
8165 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8166 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
8167 /* Build the pty request. */
8168 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8169 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8170 ssh2_pkt_addstring(s->pktout, "pty-req");
8171 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8172 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
8173 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
8174 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
8175 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
8176 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
8177 ssh2_pkt_addstring_start(s->pktout);
8178 parse_ttymodes(ssh, ssh->cfg.ttymodes,
8179 ssh2_send_ttymode, (void *)s->pktout);
8180 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
8181 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
8182 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
8183 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
8184 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
8185 ssh2_pkt_send(ssh, s->pktout);
8186 ssh->state = SSH_STATE_INTERMED;
8188 crWaitUntilV(pktin);
8190 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8191 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8192 bombout(("Unexpected response to pty request:"
8193 " packet type %d", pktin->type));
8196 c_write_str(ssh, "Server refused to allocate pty\r\n");
8197 ssh->editing = ssh->echoing = 1;
8199 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8200 ssh->ospeed, ssh->ispeed);
8203 ssh->editing = ssh->echoing = 1;
8207 * Send environment variables.
8209 * Simplest thing here is to send all the requests at once, and
8210 * then wait for a whole bunch of successes or failures.
8212 if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) {
8213 char *e = ssh->cfg.environmt;
8214 char *var, *varend, *val;
8220 while (*e && *e != '\t') e++;
8222 if (*e == '\t') e++;
8227 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8228 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8229 ssh2_pkt_addstring(s->pktout, "env");
8230 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8231 ssh2_pkt_addstring_start(s->pktout);
8232 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
8233 ssh2_pkt_addstring(s->pktout, val);
8234 ssh2_pkt_send(ssh, s->pktout);
8239 logeventf(ssh, "Sent %d environment variables", s->num_env);
8242 s->env_left = s->num_env;
8244 while (s->env_left > 0) {
8245 crWaitUntilV(pktin);
8247 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8248 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8249 bombout(("Unexpected response to environment request:"
8250 " packet type %d", pktin->type));
8260 if (s->env_ok == s->num_env) {
8261 logevent("All environment variables successfully set");
8262 } else if (s->env_ok == 0) {
8263 logevent("All environment variables refused");
8264 c_write_str(ssh, "Server refused to set environment variables\r\n");
8266 logeventf(ssh, "%d environment variables refused",
8267 s->num_env - s->env_ok);
8268 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8273 * Start a shell or a remote command. We may have to attempt
8274 * this twice if the config data has provided a second choice
8277 if (ssh->mainchan && !ssh->ncmode) while (1) {
8281 if (ssh->fallback_cmd) {
8282 subsys = ssh->cfg.ssh_subsys2;
8283 cmd = ssh->cfg.remote_cmd_ptr2;
8285 subsys = ssh->cfg.ssh_subsys;
8286 cmd = ssh->cfg.remote_cmd_ptr;
8287 if (!cmd) cmd = ssh->cfg.remote_cmd;
8290 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8291 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8293 ssh2_pkt_addstring(s->pktout, "subsystem");
8294 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8295 ssh2_pkt_addstring(s->pktout, cmd);
8297 ssh2_pkt_addstring(s->pktout, "exec");
8298 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8299 ssh2_pkt_addstring(s->pktout, cmd);
8301 ssh2_pkt_addstring(s->pktout, "shell");
8302 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8304 ssh2_pkt_send(ssh, s->pktout);
8306 crWaitUntilV(pktin);
8308 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8309 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8310 bombout(("Unexpected response to shell/command request:"
8311 " packet type %d", pktin->type));
8315 * We failed to start the command. If this is the
8316 * fallback command, we really are finished; if it's
8317 * not, and if the fallback command exists, try falling
8318 * back to it before complaining.
8320 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
8321 logevent("Primary command failed; attempting fallback");
8322 ssh->fallback_cmd = TRUE;
8325 bombout(("Server refused to start a shell/command"));
8328 logevent("Started a shell/command");
8333 ssh->state = SSH_STATE_SESSION;
8334 if (ssh->size_needed)
8335 ssh_size(ssh, ssh->term_width, ssh->term_height);
8336 if (ssh->eof_needed)
8337 ssh_special(ssh, TS_EOF);
8343 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
8348 s->try_send = FALSE;
8352 * _All_ the connection-layer packets we expect to
8353 * receive are now handled by the dispatch table.
8354 * Anything that reaches here must be bogus.
8357 bombout(("Strange packet received: type %d", pktin->type));
8359 } else if (ssh->mainchan) {
8361 * We have spare data. Add it to the channel buffer.
8363 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
8368 struct ssh_channel *c;
8370 * Try to send data on all channels if we can.
8372 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
8373 ssh2_try_send_and_unthrottle(c);
8381 * Handlers for SSH-2 messages that might arrive at any moment.
8383 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
8385 /* log reason code in disconnect message */
8387 int nowlen, reason, msglen;
8389 reason = ssh_pkt_getuint32(pktin);
8390 ssh_pkt_getstring(pktin, &msg, &msglen);
8392 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
8393 buf = dupprintf("Received disconnect message (%s)",
8394 ssh2_disconnect_reasons[reason]);
8396 buf = dupprintf("Received disconnect message (unknown"
8397 " type %d)", reason);
8401 buf = dupprintf("Disconnection message text: %n%.*s",
8402 &nowlen, msglen, msg);
8404 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
8406 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
8407 ssh2_disconnect_reasons[reason] : "unknown",
8412 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
8414 /* log the debug message */
8419 /* XXX maybe we should actually take notice of this */
8420 always_display = ssh2_pkt_getbool(pktin);
8421 ssh_pkt_getstring(pktin, &msg, &msglen);
8423 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
8426 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
8428 struct Packet *pktout;
8429 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
8430 ssh2_pkt_adduint32(pktout, pktin->sequence);
8432 * UNIMPLEMENTED messages MUST appear in the same order as the
8433 * messages they respond to. Hence, never queue them.
8435 ssh2_pkt_send_noqueue(ssh, pktout);
8439 * Handle the top-level SSH-2 protocol.
8441 static void ssh2_protocol_setup(Ssh ssh)
8446 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
8448 for (i = 0; i < 256; i++)
8449 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
8452 * Any message we actually understand, we set to NULL so that
8453 * the coroutines will get it.
8455 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
8456 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
8457 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
8458 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
8459 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
8460 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
8461 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
8462 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
8463 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
8464 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
8465 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
8466 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
8467 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
8468 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
8469 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
8470 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
8471 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
8472 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
8473 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
8474 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
8475 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
8476 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
8477 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
8478 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
8479 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
8480 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
8481 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
8482 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
8483 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
8484 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
8485 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
8486 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
8487 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
8490 * These special message types we install handlers for.
8492 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
8493 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
8494 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
8497 static void ssh2_timer(void *ctx, long now)
8501 if (ssh->state == SSH_STATE_CLOSED)
8504 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
8505 now - ssh->next_rekey >= 0) {
8506 do_ssh2_transport(ssh, "timeout", -1, NULL);
8510 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
8511 struct Packet *pktin)
8513 unsigned char *in = (unsigned char *)vin;
8514 if (ssh->state == SSH_STATE_CLOSED)
8518 ssh->incoming_data_size += pktin->encrypted_len;
8519 if (!ssh->kex_in_progress &&
8520 ssh->max_data_size != 0 &&
8521 ssh->incoming_data_size > ssh->max_data_size)
8522 do_ssh2_transport(ssh, "too much data received", -1, NULL);
8525 if (pktin && ssh->packet_dispatch[pktin->type]) {
8526 ssh->packet_dispatch[pktin->type](ssh, pktin);
8530 if (!ssh->protocol_initial_phase_done ||
8531 (pktin && pktin->type >= 20 && pktin->type < 50)) {
8532 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
8533 !ssh->protocol_initial_phase_done) {
8534 ssh->protocol_initial_phase_done = TRUE;
8536 * Allow authconn to initialise itself.
8538 do_ssh2_authconn(ssh, NULL, 0, NULL);
8541 do_ssh2_authconn(ssh, in, inlen, pktin);
8546 * Called to set up the connection.
8548 * Returns an error message, or NULL on success.
8550 static const char *ssh_init(void *frontend_handle, void **backend_handle,
8552 char *host, int port, char **realhost, int nodelay,
8558 ssh = snew(struct ssh_tag);
8559 ssh->cfg = *cfg; /* STRUCTURE COPY */
8560 ssh->version = 0; /* when not ready yet */
8563 ssh->v1_cipher_ctx = NULL;
8564 ssh->crcda_ctx = NULL;
8565 ssh->cscipher = NULL;
8566 ssh->cs_cipher_ctx = NULL;
8567 ssh->sccipher = NULL;
8568 ssh->sc_cipher_ctx = NULL;
8570 ssh->cs_mac_ctx = NULL;
8572 ssh->sc_mac_ctx = NULL;
8574 ssh->cs_comp_ctx = NULL;
8576 ssh->sc_comp_ctx = NULL;
8578 ssh->kex_ctx = NULL;
8579 ssh->hostkey = NULL;
8581 ssh->close_expected = FALSE;
8582 ssh->clean_exit = FALSE;
8583 ssh->state = SSH_STATE_PREPACKET;
8584 ssh->size_needed = FALSE;
8585 ssh->eof_needed = FALSE;
8588 ssh->deferred_send_data = NULL;
8589 ssh->deferred_len = 0;
8590 ssh->deferred_size = 0;
8591 ssh->fallback_cmd = 0;
8592 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
8593 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8594 ssh->x11auth = NULL;
8595 ssh->v1_compressing = FALSE;
8596 ssh->v2_outgoing_sequence = 0;
8597 ssh->ssh1_rdpkt_crstate = 0;
8598 ssh->ssh2_rdpkt_crstate = 0;
8599 ssh->do_ssh_init_crstate = 0;
8600 ssh->ssh_gotdata_crstate = 0;
8601 ssh->do_ssh1_connection_crstate = 0;
8602 ssh->do_ssh1_login_crstate = 0;
8603 ssh->do_ssh2_transport_crstate = 0;
8604 ssh->do_ssh2_authconn_crstate = 0;
8605 ssh->do_ssh_init_state = NULL;
8606 ssh->do_ssh1_login_state = NULL;
8607 ssh->do_ssh2_transport_state = NULL;
8608 ssh->do_ssh2_authconn_state = NULL;
8611 ssh->mainchan = NULL;
8612 ssh->throttled_all = 0;
8613 ssh->v1_stdout_throttling = 0;
8615 ssh->queuelen = ssh->queuesize = 0;
8616 ssh->queueing = FALSE;
8617 ssh->qhead = ssh->qtail = NULL;
8618 ssh->deferred_rekey_reason = NULL;
8619 bufchain_init(&ssh->queued_incoming_data);
8620 ssh->frozen = FALSE;
8622 *backend_handle = ssh;
8625 if (crypto_startup() == 0)
8626 return "Microsoft high encryption pack not installed!";
8629 ssh->frontend = frontend_handle;
8630 ssh->term_width = ssh->cfg.width;
8631 ssh->term_height = ssh->cfg.height;
8633 ssh->channels = NULL;
8634 ssh->rportfwds = NULL;
8635 ssh->portfwds = NULL;
8640 ssh->v1_throttle_count = 0;
8641 ssh->overall_bufsize = 0;
8642 ssh->fallback_cmd = 0;
8644 ssh->protocol = NULL;
8646 ssh->protocol_initial_phase_done = FALSE;
8650 ssh->incoming_data_size = ssh->outgoing_data_size =
8651 ssh->deferred_data_size = 0L;
8652 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
8653 ssh->kex_in_progress = FALSE;
8655 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
8664 static void ssh_free(void *handle)
8666 Ssh ssh = (Ssh) handle;
8667 struct ssh_channel *c;
8668 struct ssh_rportfwd *pf;
8670 if (ssh->v1_cipher_ctx)
8671 ssh->cipher->free_context(ssh->v1_cipher_ctx);
8672 if (ssh->cs_cipher_ctx)
8673 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
8674 if (ssh->sc_cipher_ctx)
8675 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
8676 if (ssh->cs_mac_ctx)
8677 ssh->csmac->free_context(ssh->cs_mac_ctx);
8678 if (ssh->sc_mac_ctx)
8679 ssh->scmac->free_context(ssh->sc_mac_ctx);
8680 if (ssh->cs_comp_ctx) {
8682 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
8684 zlib_compress_cleanup(ssh->cs_comp_ctx);
8686 if (ssh->sc_comp_ctx) {
8688 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
8690 zlib_decompress_cleanup(ssh->sc_comp_ctx);
8693 dh_cleanup(ssh->kex_ctx);
8694 sfree(ssh->savedhost);
8696 while (ssh->queuelen-- > 0)
8697 ssh_free_packet(ssh->queue[ssh->queuelen]);
8700 while (ssh->qhead) {
8701 struct queued_handler *qh = ssh->qhead;
8702 ssh->qhead = qh->next;
8705 ssh->qhead = ssh->qtail = NULL;
8707 if (ssh->channels) {
8708 while ((c = delpos234(ssh->channels, 0)) != NULL) {
8711 if (c->u.x11.s != NULL)
8712 x11_close(c->u.x11.s);
8715 if (c->u.pfd.s != NULL)
8716 pfd_close(c->u.pfd.s);
8721 freetree234(ssh->channels);
8722 ssh->channels = NULL;
8725 if (ssh->rportfwds) {
8726 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8728 freetree234(ssh->rportfwds);
8729 ssh->rportfwds = NULL;
8731 sfree(ssh->deferred_send_data);
8733 x11_free_auth(ssh->x11auth);
8734 sfree(ssh->do_ssh_init_state);
8735 sfree(ssh->do_ssh1_login_state);
8736 sfree(ssh->do_ssh2_transport_state);
8737 sfree(ssh->do_ssh2_authconn_state);
8740 if (ssh->crcda_ctx) {
8741 crcda_free_context(ssh->crcda_ctx);
8742 ssh->crcda_ctx = NULL;
8745 ssh_do_close(ssh, TRUE);
8746 expire_timer_context(ssh);
8748 pinger_free(ssh->pinger);
8749 bufchain_clear(&ssh->queued_incoming_data);
8756 * Reconfigure the SSH backend.
8758 static void ssh_reconfig(void *handle, Config *cfg)
8760 Ssh ssh = (Ssh) handle;
8761 char *rekeying = NULL, rekey_mandatory = FALSE;
8762 unsigned long old_max_data_size;
8764 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
8766 ssh_setup_portfwd(ssh, cfg);
8768 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8769 cfg->ssh_rekey_time != 0) {
8770 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8771 long now = GETTICKCOUNT();
8773 if (new_next - now < 0) {
8774 rekeying = "timeout shortened";
8776 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8780 old_max_data_size = ssh->max_data_size;
8781 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8782 if (old_max_data_size != ssh->max_data_size &&
8783 ssh->max_data_size != 0) {
8784 if (ssh->outgoing_data_size > ssh->max_data_size ||
8785 ssh->incoming_data_size > ssh->max_data_size)
8786 rekeying = "data limit lowered";
8789 if (ssh->cfg.compression != cfg->compression) {
8790 rekeying = "compression setting changed";
8791 rekey_mandatory = TRUE;
8794 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8795 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8796 sizeof(ssh->cfg.ssh_cipherlist))) {
8797 rekeying = "cipher settings changed";
8798 rekey_mandatory = TRUE;
8801 ssh->cfg = *cfg; /* STRUCTURE COPY */
8804 if (!ssh->kex_in_progress) {
8805 do_ssh2_transport(ssh, rekeying, -1, NULL);
8806 } else if (rekey_mandatory) {
8807 ssh->deferred_rekey_reason = rekeying;
8813 * Called to send data down the SSH connection.
8815 static int ssh_send(void *handle, char *buf, int len)
8817 Ssh ssh = (Ssh) handle;
8819 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8822 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8824 return ssh_sendbuffer(ssh);
8828 * Called to query the current amount of buffered stdin data.
8830 static int ssh_sendbuffer(void *handle)
8832 Ssh ssh = (Ssh) handle;
8835 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8839 * If the SSH socket itself has backed up, add the total backup
8840 * size on that to any individual buffer on the stdin channel.
8843 if (ssh->throttled_all)
8844 override_value = ssh->overall_bufsize;
8846 if (ssh->version == 1) {
8847 return override_value;
8848 } else if (ssh->version == 2) {
8849 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8850 return override_value;
8852 return (override_value +
8853 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8860 * Called to set the size of the window from SSH's POV.
8862 static void ssh_size(void *handle, int width, int height)
8864 Ssh ssh = (Ssh) handle;
8865 struct Packet *pktout;
8867 ssh->term_width = width;
8868 ssh->term_height = height;
8870 switch (ssh->state) {
8871 case SSH_STATE_BEFORE_SIZE:
8872 case SSH_STATE_PREPACKET:
8873 case SSH_STATE_CLOSED:
8874 break; /* do nothing */
8875 case SSH_STATE_INTERMED:
8876 ssh->size_needed = TRUE; /* buffer for later */
8878 case SSH_STATE_SESSION:
8879 if (!ssh->cfg.nopty) {
8880 if (ssh->version == 1) {
8881 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8882 PKT_INT, ssh->term_height,
8883 PKT_INT, ssh->term_width,
8884 PKT_INT, 0, PKT_INT, 0, PKT_END);
8885 } else if (ssh->mainchan) {
8886 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8887 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8888 ssh2_pkt_addstring(pktout, "window-change");
8889 ssh2_pkt_addbool(pktout, 0);
8890 ssh2_pkt_adduint32(pktout, ssh->term_width);
8891 ssh2_pkt_adduint32(pktout, ssh->term_height);
8892 ssh2_pkt_adduint32(pktout, 0);
8893 ssh2_pkt_adduint32(pktout, 0);
8894 ssh2_pkt_send(ssh, pktout);
8902 * Return a list of the special codes that make sense in this
8905 static const struct telnet_special *ssh_get_specials(void *handle)
8907 static const struct telnet_special ssh1_ignore_special[] = {
8908 {"IGNORE message", TS_NOP}
8910 static const struct telnet_special ssh2_transport_specials[] = {
8911 {"IGNORE message", TS_NOP},
8912 {"Repeat key exchange", TS_REKEY},
8914 static const struct telnet_special ssh2_session_specials[] = {
8917 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8918 * They include all the ISO C signals, but are a subset of the POSIX
8919 * required signals. */
8920 {"SIGINT (Interrupt)", TS_SIGINT},
8921 {"SIGTERM (Terminate)", TS_SIGTERM},
8922 {"SIGKILL (Kill)", TS_SIGKILL},
8923 {"SIGQUIT (Quit)", TS_SIGQUIT},
8924 {"SIGHUP (Hangup)", TS_SIGHUP},
8925 {"More signals", TS_SUBMENU},
8926 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8927 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8928 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8929 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8932 static const struct telnet_special specials_end[] = {
8935 /* XXX review this length for any changes: */
8936 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8937 lenof(ssh2_session_specials) +
8938 lenof(specials_end)];
8939 Ssh ssh = (Ssh) handle;
8941 #define ADD_SPECIALS(name) \
8943 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8944 memcpy(&ssh_specials[i], name, sizeof name); \
8948 if (ssh->version == 1) {
8949 /* Don't bother offering IGNORE if we've decided the remote
8950 * won't cope with it, since we wouldn't bother sending it if
8952 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8953 ADD_SPECIALS(ssh1_ignore_special);
8954 } else if (ssh->version == 2) {
8955 ADD_SPECIALS(ssh2_transport_specials);
8957 ADD_SPECIALS(ssh2_session_specials);
8958 } /* else we're not ready yet */
8961 ADD_SPECIALS(specials_end);
8962 return ssh_specials;
8970 * Send special codes. TS_EOF is useful for `plink', so you
8971 * can send an EOF and collect resulting output (e.g. `plink
8974 static void ssh_special(void *handle, Telnet_Special code)
8976 Ssh ssh = (Ssh) handle;
8977 struct Packet *pktout;
8979 if (code == TS_EOF) {
8980 if (ssh->state != SSH_STATE_SESSION) {
8982 * Buffer the EOF in case we are pre-SESSION, so we can
8983 * send it as soon as we reach SESSION.
8986 ssh->eof_needed = TRUE;
8989 if (ssh->version == 1) {
8990 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8991 } else if (ssh->mainchan) {
8992 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8993 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8994 ssh2_pkt_send(ssh, pktout);
8995 ssh->send_ok = 0; /* now stop trying to read from stdin */
8997 logevent("Sent EOF message");
8998 } else if (code == TS_PING || code == TS_NOP) {
8999 if (ssh->state == SSH_STATE_CLOSED
9000 || ssh->state == SSH_STATE_PREPACKET) return;
9001 if (ssh->version == 1) {
9002 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9003 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
9005 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
9006 ssh2_pkt_addstring_start(pktout);
9007 ssh2_pkt_send_noqueue(ssh, pktout);
9009 } else if (code == TS_REKEY) {
9010 if (!ssh->kex_in_progress && ssh->version == 2) {
9011 do_ssh2_transport(ssh, "at user request", -1, NULL);
9013 } else if (code == TS_BRK) {
9014 if (ssh->state == SSH_STATE_CLOSED
9015 || ssh->state == SSH_STATE_PREPACKET) return;
9016 if (ssh->version == 1) {
9017 logevent("Unable to send BREAK signal in SSH-1");
9018 } else if (ssh->mainchan) {
9019 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9020 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9021 ssh2_pkt_addstring(pktout, "break");
9022 ssh2_pkt_addbool(pktout, 0);
9023 ssh2_pkt_adduint32(pktout, 0); /* default break length */
9024 ssh2_pkt_send(ssh, pktout);
9027 /* Is is a POSIX signal? */
9028 char *signame = NULL;
9029 if (code == TS_SIGABRT) signame = "ABRT";
9030 if (code == TS_SIGALRM) signame = "ALRM";
9031 if (code == TS_SIGFPE) signame = "FPE";
9032 if (code == TS_SIGHUP) signame = "HUP";
9033 if (code == TS_SIGILL) signame = "ILL";
9034 if (code == TS_SIGINT) signame = "INT";
9035 if (code == TS_SIGKILL) signame = "KILL";
9036 if (code == TS_SIGPIPE) signame = "PIPE";
9037 if (code == TS_SIGQUIT) signame = "QUIT";
9038 if (code == TS_SIGSEGV) signame = "SEGV";
9039 if (code == TS_SIGTERM) signame = "TERM";
9040 if (code == TS_SIGUSR1) signame = "USR1";
9041 if (code == TS_SIGUSR2) signame = "USR2";
9042 /* The SSH-2 protocol does in principle support arbitrary named
9043 * signals, including signame@domain, but we don't support those. */
9045 /* It's a signal. */
9046 if (ssh->version == 2 && ssh->mainchan) {
9047 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9048 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9049 ssh2_pkt_addstring(pktout, "signal");
9050 ssh2_pkt_addbool(pktout, 0);
9051 ssh2_pkt_addstring(pktout, signame);
9052 ssh2_pkt_send(ssh, pktout);
9053 logeventf(ssh, "Sent signal SIG%s", signame);
9056 /* Never heard of it. Do nothing */
9061 void *new_sock_channel(void *handle, Socket s)
9063 Ssh ssh = (Ssh) handle;
9064 struct ssh_channel *c;
9065 c = snew(struct ssh_channel);
9070 c->localid = alloc_channel_id(ssh);
9072 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
9074 bufchain_init(&c->v.v2.outbuffer);
9075 add234(ssh->channels, c);
9081 * This is called when stdout/stderr (the entity to which
9082 * from_backend sends data) manages to clear some backlog.
9084 static void ssh_unthrottle(void *handle, int bufsize)
9086 Ssh ssh = (Ssh) handle;
9087 if (ssh->version == 1) {
9088 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
9089 ssh->v1_stdout_throttling = 0;
9090 ssh1_throttle(ssh, -1);
9094 ssh2_set_window(ssh->mainchan,
9095 ssh->mainchan->v.v2.locmaxwin - bufsize);
9099 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
9101 struct ssh_channel *c = (struct ssh_channel *)channel;
9103 struct Packet *pktout;
9105 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
9107 if (ssh->version == 1) {
9108 send_packet(ssh, SSH1_MSG_PORT_OPEN,
9109 PKT_INT, c->localid,
9112 /* PKT_STR, <org:orgport>, */
9115 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
9116 ssh2_pkt_addstring(pktout, "direct-tcpip");
9117 ssh2_pkt_adduint32(pktout, c->localid);
9118 c->v.v2.locwindow = c->v.v2.locmaxwin = OUR_V2_WINSIZE;
9119 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
9120 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
9121 ssh2_pkt_addstring(pktout, hostname);
9122 ssh2_pkt_adduint32(pktout, port);
9124 * We make up values for the originator data; partly it's
9125 * too much hassle to keep track, and partly I'm not
9126 * convinced the server should be told details like that
9127 * about my local network configuration.
9128 * The "originator IP address" is syntactically a numeric
9129 * IP address, and some servers (e.g., Tectia) get upset
9130 * if it doesn't match this syntax.
9132 ssh2_pkt_addstring(pktout, "0.0.0.0");
9133 ssh2_pkt_adduint32(pktout, 0);
9134 ssh2_pkt_send(ssh, pktout);
9138 static int ssh_connected(void *handle)
9140 Ssh ssh = (Ssh) handle;
9141 return ssh->s != NULL;
9144 static int ssh_sendok(void *handle)
9146 Ssh ssh = (Ssh) handle;
9147 return ssh->send_ok;
9150 static int ssh_ldisc(void *handle, int option)
9152 Ssh ssh = (Ssh) handle;
9153 if (option == LD_ECHO)
9154 return ssh->echoing;
9155 if (option == LD_EDIT)
9156 return ssh->editing;
9160 static void ssh_provide_ldisc(void *handle, void *ldisc)
9162 Ssh ssh = (Ssh) handle;
9166 static void ssh_provide_logctx(void *handle, void *logctx)
9168 Ssh ssh = (Ssh) handle;
9169 ssh->logctx = logctx;
9172 static int ssh_return_exitcode(void *handle)
9174 Ssh ssh = (Ssh) handle;
9178 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
9182 * cfg_info for SSH is the currently running version of the
9183 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
9185 static int ssh_cfg_info(void *handle)
9187 Ssh ssh = (Ssh) handle;
9188 return ssh->version;
9192 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
9193 * that fails. This variable is the means by which scp.c can reach
9194 * into the SSH code and find out which one it got.
9196 extern int ssh_fallback_cmd(void *handle)
9198 Ssh ssh = (Ssh) handle;
9199 return ssh->fallback_cmd;
9202 Backend ssh_backend = {
9212 ssh_return_exitcode,