27 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
28 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
29 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
30 #define SSH1_CMSG_USER 4 /* 0x4 */
31 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
32 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
33 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
34 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
35 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
36 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
37 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
38 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
39 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
40 #define SSH1_SMSG_FAILURE 15 /* 0xf */
41 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
42 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
43 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
44 #define SSH1_CMSG_EOF 19 /* 0x13 */
45 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
46 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
47 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
48 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
49 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
50 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
51 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
52 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
53 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
54 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
55 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
56 #define SSH1_MSG_IGNORE 32 /* 0x20 */
57 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
58 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
59 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
60 #define SSH1_MSG_DEBUG 36 /* 0x24 */
61 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
62 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
63 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
64 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
65 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
66 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
67 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
69 #define SSH1_AUTH_RHOSTS 1 /* 0x1 */
70 #define SSH1_AUTH_RSA 2 /* 0x2 */
71 #define SSH1_AUTH_PASSWORD 3 /* 0x3 */
72 #define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */
73 #define SSH1_AUTH_TIS 5 /* 0x5 */
74 #define SSH1_AUTH_CCARD 16 /* 0x10 */
76 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
77 /* Mask for protoflags we will echo back to server if seen */
78 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
80 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
81 #define SSH2_MSG_IGNORE 2 /* 0x2 */
82 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
83 #define SSH2_MSG_DEBUG 4 /* 0x4 */
84 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
85 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
86 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
87 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
88 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
89 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
90 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
91 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
92 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
93 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
94 #define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */
95 #define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */
96 #define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */
97 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
98 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
99 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
100 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
101 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
102 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
103 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
104 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
105 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
106 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
107 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
108 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
109 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
110 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
111 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
112 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
113 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
114 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
115 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
116 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
117 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
118 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
119 #define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60
120 #define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61
121 #define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63
122 #define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64
123 #define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65
124 #define SSH2_MSG_USERAUTH_GSSAPI_MIC 66
127 * Packet type contexts, so that ssh2_pkt_type can correctly decode
128 * the ambiguous type numbers back into the correct type strings.
138 SSH2_PKTCTX_PUBLICKEY,
139 SSH2_PKTCTX_PASSWORD,
144 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
145 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
146 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
147 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
148 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
149 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
150 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
151 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
152 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
153 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
154 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
155 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
156 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
157 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
158 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
160 static const char *const ssh2_disconnect_reasons[] = {
162 "host not allowed to connect",
164 "key exchange failed",
165 "host authentication failed",
168 "service not available",
169 "protocol version not supported",
170 "host key not verifiable",
173 "too many connections",
174 "auth cancelled by user",
175 "no more auth methods available",
179 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
180 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
181 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
182 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
184 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
187 * Various remote-bug flags.
189 #define BUG_CHOKES_ON_SSH1_IGNORE 1
190 #define BUG_SSH2_HMAC 2
191 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
192 #define BUG_CHOKES_ON_RSA 8
193 #define BUG_SSH2_RSA_PADDING 16
194 #define BUG_SSH2_DERIVEKEY 32
195 #define BUG_SSH2_REKEY 64
196 #define BUG_SSH2_PK_SESSIONID 128
197 #define BUG_SSH2_MAXPKT 256
198 #define BUG_CHOKES_ON_SSH2_IGNORE 512
201 * Codes for terminal modes.
202 * Most of these are the same in SSH-1 and SSH-2.
203 * This list is derived from RFC 4254 and
206 static const struct {
207 const char* const mode;
209 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
211 /* "V" prefix discarded for special characters relative to SSH specs */
212 { "INTR", 1, TTY_OP_CHAR },
213 { "QUIT", 2, TTY_OP_CHAR },
214 { "ERASE", 3, TTY_OP_CHAR },
215 { "KILL", 4, TTY_OP_CHAR },
216 { "EOF", 5, TTY_OP_CHAR },
217 { "EOL", 6, TTY_OP_CHAR },
218 { "EOL2", 7, TTY_OP_CHAR },
219 { "START", 8, TTY_OP_CHAR },
220 { "STOP", 9, TTY_OP_CHAR },
221 { "SUSP", 10, TTY_OP_CHAR },
222 { "DSUSP", 11, TTY_OP_CHAR },
223 { "REPRINT", 12, TTY_OP_CHAR },
224 { "WERASE", 13, TTY_OP_CHAR },
225 { "LNEXT", 14, TTY_OP_CHAR },
226 { "FLUSH", 15, TTY_OP_CHAR },
227 { "SWTCH", 16, TTY_OP_CHAR },
228 { "STATUS", 17, TTY_OP_CHAR },
229 { "DISCARD", 18, TTY_OP_CHAR },
230 { "IGNPAR", 30, TTY_OP_BOOL },
231 { "PARMRK", 31, TTY_OP_BOOL },
232 { "INPCK", 32, TTY_OP_BOOL },
233 { "ISTRIP", 33, TTY_OP_BOOL },
234 { "INLCR", 34, TTY_OP_BOOL },
235 { "IGNCR", 35, TTY_OP_BOOL },
236 { "ICRNL", 36, TTY_OP_BOOL },
237 { "IUCLC", 37, TTY_OP_BOOL },
238 { "IXON", 38, TTY_OP_BOOL },
239 { "IXANY", 39, TTY_OP_BOOL },
240 { "IXOFF", 40, TTY_OP_BOOL },
241 { "IMAXBEL", 41, TTY_OP_BOOL },
242 { "ISIG", 50, TTY_OP_BOOL },
243 { "ICANON", 51, TTY_OP_BOOL },
244 { "XCASE", 52, TTY_OP_BOOL },
245 { "ECHO", 53, TTY_OP_BOOL },
246 { "ECHOE", 54, TTY_OP_BOOL },
247 { "ECHOK", 55, TTY_OP_BOOL },
248 { "ECHONL", 56, TTY_OP_BOOL },
249 { "NOFLSH", 57, TTY_OP_BOOL },
250 { "TOSTOP", 58, TTY_OP_BOOL },
251 { "IEXTEN", 59, TTY_OP_BOOL },
252 { "ECHOCTL", 60, TTY_OP_BOOL },
253 { "ECHOKE", 61, TTY_OP_BOOL },
254 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
255 { "OPOST", 70, TTY_OP_BOOL },
256 { "OLCUC", 71, TTY_OP_BOOL },
257 { "ONLCR", 72, TTY_OP_BOOL },
258 { "OCRNL", 73, TTY_OP_BOOL },
259 { "ONOCR", 74, TTY_OP_BOOL },
260 { "ONLRET", 75, TTY_OP_BOOL },
261 { "CS7", 90, TTY_OP_BOOL },
262 { "CS8", 91, TTY_OP_BOOL },
263 { "PARENB", 92, TTY_OP_BOOL },
264 { "PARODD", 93, TTY_OP_BOOL }
267 /* Miscellaneous other tty-related constants. */
268 #define SSH_TTY_OP_END 0
269 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
270 #define SSH1_TTY_OP_ISPEED 192
271 #define SSH1_TTY_OP_OSPEED 193
272 #define SSH2_TTY_OP_ISPEED 128
273 #define SSH2_TTY_OP_OSPEED 129
275 /* Helper functions for parsing tty-related config. */
276 static unsigned int ssh_tty_parse_specchar(char *s)
281 ret = ctrlparse(s, &next);
282 if (!next) ret = s[0];
284 ret = 255; /* special value meaning "don't set" */
288 static unsigned int ssh_tty_parse_boolean(char *s)
290 if (stricmp(s, "yes") == 0 ||
291 stricmp(s, "on") == 0 ||
292 stricmp(s, "true") == 0 ||
293 stricmp(s, "+") == 0)
295 else if (stricmp(s, "no") == 0 ||
296 stricmp(s, "off") == 0 ||
297 stricmp(s, "false") == 0 ||
298 stricmp(s, "-") == 0)
299 return 0; /* false */
301 return (atoi(s) != 0);
304 #define translate(x) if (type == x) return #x
305 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
306 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
307 static char *ssh1_pkt_type(int type)
309 translate(SSH1_MSG_DISCONNECT);
310 translate(SSH1_SMSG_PUBLIC_KEY);
311 translate(SSH1_CMSG_SESSION_KEY);
312 translate(SSH1_CMSG_USER);
313 translate(SSH1_CMSG_AUTH_RSA);
314 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
315 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
316 translate(SSH1_CMSG_AUTH_PASSWORD);
317 translate(SSH1_CMSG_REQUEST_PTY);
318 translate(SSH1_CMSG_WINDOW_SIZE);
319 translate(SSH1_CMSG_EXEC_SHELL);
320 translate(SSH1_CMSG_EXEC_CMD);
321 translate(SSH1_SMSG_SUCCESS);
322 translate(SSH1_SMSG_FAILURE);
323 translate(SSH1_CMSG_STDIN_DATA);
324 translate(SSH1_SMSG_STDOUT_DATA);
325 translate(SSH1_SMSG_STDERR_DATA);
326 translate(SSH1_CMSG_EOF);
327 translate(SSH1_SMSG_EXIT_STATUS);
328 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
329 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
330 translate(SSH1_MSG_CHANNEL_DATA);
331 translate(SSH1_MSG_CHANNEL_CLOSE);
332 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
333 translate(SSH1_SMSG_X11_OPEN);
334 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
335 translate(SSH1_MSG_PORT_OPEN);
336 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
337 translate(SSH1_SMSG_AGENT_OPEN);
338 translate(SSH1_MSG_IGNORE);
339 translate(SSH1_CMSG_EXIT_CONFIRMATION);
340 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
341 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
342 translate(SSH1_MSG_DEBUG);
343 translate(SSH1_CMSG_REQUEST_COMPRESSION);
344 translate(SSH1_CMSG_AUTH_TIS);
345 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
346 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
347 translate(SSH1_CMSG_AUTH_CCARD);
348 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
349 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
352 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
354 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
355 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
356 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
357 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
358 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
359 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
360 translate(SSH2_MSG_DISCONNECT);
361 translate(SSH2_MSG_IGNORE);
362 translate(SSH2_MSG_UNIMPLEMENTED);
363 translate(SSH2_MSG_DEBUG);
364 translate(SSH2_MSG_SERVICE_REQUEST);
365 translate(SSH2_MSG_SERVICE_ACCEPT);
366 translate(SSH2_MSG_KEXINIT);
367 translate(SSH2_MSG_NEWKEYS);
368 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
369 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
370 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
371 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
372 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
373 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
374 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
375 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
376 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
377 translate(SSH2_MSG_USERAUTH_REQUEST);
378 translate(SSH2_MSG_USERAUTH_FAILURE);
379 translate(SSH2_MSG_USERAUTH_SUCCESS);
380 translate(SSH2_MSG_USERAUTH_BANNER);
381 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
382 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
383 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
384 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
385 translate(SSH2_MSG_GLOBAL_REQUEST);
386 translate(SSH2_MSG_REQUEST_SUCCESS);
387 translate(SSH2_MSG_REQUEST_FAILURE);
388 translate(SSH2_MSG_CHANNEL_OPEN);
389 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
390 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
391 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
392 translate(SSH2_MSG_CHANNEL_DATA);
393 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
394 translate(SSH2_MSG_CHANNEL_EOF);
395 translate(SSH2_MSG_CHANNEL_CLOSE);
396 translate(SSH2_MSG_CHANNEL_REQUEST);
397 translate(SSH2_MSG_CHANNEL_SUCCESS);
398 translate(SSH2_MSG_CHANNEL_FAILURE);
404 /* Enumeration values for fields in SSH-1 packets */
406 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
407 /* These values are for communicating relevant semantics of
408 * fields to the packet logging code. */
409 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
413 * Coroutine mechanics for the sillier bits of the code. If these
414 * macros look impenetrable to you, you might find it helpful to
417 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
419 * which explains the theory behind these macros.
421 * In particular, if you are getting `case expression not constant'
422 * errors when building with MS Visual Studio, this is because MS's
423 * Edit and Continue debugging feature causes their compiler to
424 * violate ANSI C. To disable Edit and Continue debugging:
426 * - right-click ssh.c in the FileView
428 * - select the C/C++ tab and the General category
429 * - under `Debug info:', select anything _other_ than `Program
430 * Database for Edit and Continue'.
432 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
435 if (!ssh->t) ssh->t = snew(struct t); \
437 #define crFinish(z) } *crLine = 0; return (z); }
438 #define crFinishV } *crLine = 0; return; }
439 #define crReturn(z) \
441 *crLine =__LINE__; return (z); case __LINE__:;\
445 *crLine=__LINE__; return; case __LINE__:;\
447 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
448 #define crStopV do{ *crLine = 0; return; }while(0)
449 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
450 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
452 typedef struct ssh_tag *Ssh;
455 static struct Packet *ssh1_pkt_init(int pkt_type);
456 static struct Packet *ssh2_pkt_init(int pkt_type);
457 static void ssh_pkt_ensure(struct Packet *, int length);
458 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
459 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
460 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
461 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
462 static void ssh_pkt_addstring_start(struct Packet *);
463 static void ssh_pkt_addstring_str(struct Packet *, char *data);
464 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
465 static void ssh_pkt_addstring(struct Packet *, char *data);
466 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
467 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
468 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
469 static int ssh2_pkt_construct(Ssh, struct Packet *);
470 static void ssh2_pkt_send(Ssh, struct Packet *);
471 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
472 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
473 struct Packet *pktin);
474 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
475 struct Packet *pktin);
478 * Buffer management constants. There are several of these for
479 * various different purposes:
481 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
482 * on a local data stream before we throttle the whole SSH
483 * connection (in SSH-1 only). Throttling the whole connection is
484 * pretty drastic so we set this high in the hope it won't
487 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
488 * on the SSH connection itself before we defensively throttle
489 * _all_ local data streams. This is pretty drastic too (though
490 * thankfully unlikely in SSH-2 since the window mechanism should
491 * ensure that the server never has any need to throttle its end
492 * of the connection), so we set this high as well.
494 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
497 * - OUR_V2_BIGWIN is the window size we advertise for the only
498 * channel in a simple connection. It must be <= INT_MAX.
500 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
501 * to the remote side. This actually has nothing to do with the
502 * size of the _packet_, but is instead a limit on the amount
503 * of data we're willing to receive in a single SSH2 channel
506 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
507 * _packet_ we're prepared to cope with. It must be a multiple
508 * of the cipher block size, and must be at least 35000.
511 #define SSH1_BUFFER_LIMIT 32768
512 #define SSH_MAX_BACKLOG 32768
513 #define OUR_V2_WINSIZE 16384
514 #define OUR_V2_BIGWIN 0x7fffffff
515 #define OUR_V2_MAXPKT 0x4000UL
516 #define OUR_V2_PACKETLIMIT 0x9000UL
518 /* Maximum length of passwords/passphrases (arbitrary) */
519 #define SSH_MAX_PASSWORD_LEN 100
521 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
523 const static struct ssh_mac *macs[] = {
524 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
526 const static struct ssh_mac *buggymacs[] = {
527 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
530 static void *ssh_comp_none_init(void)
534 static void ssh_comp_none_cleanup(void *handle)
537 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
538 unsigned char **outblock, int *outlen)
542 static int ssh_comp_none_disable(void *handle)
546 const static struct ssh_compress ssh_comp_none = {
548 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
549 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
550 ssh_comp_none_disable, NULL
552 extern const struct ssh_compress ssh_zlib;
553 const static struct ssh_compress *compressions[] = {
554 &ssh_zlib, &ssh_comp_none
557 enum { /* channel types */
562 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
566 * little structure to keep track of outstanding WINDOW_ADJUSTs
574 * 2-3-4 tree storing channels.
577 Ssh ssh; /* pointer back to main context */
578 unsigned remoteid, localid;
580 /* True if we opened this channel but server hasn't confirmed. */
583 * In SSH-1, this value contains four bits:
585 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
586 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
587 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
588 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
590 * A channel is completely finished with when all four bits are set.
595 * This flag indicates that a close is pending on the outgoing
596 * side of the channel: that is, wherever we're getting the data
597 * for this channel has sent us some data followed by EOF. We
598 * can't actually close the channel until we've finished sending
599 * the data, so we set this flag instead to remind us to
600 * initiate the closing process once our buffer is clear.
605 * True if this channel is causing the underlying connection to be
610 struct ssh2_data_channel {
612 unsigned remwindow, remmaxpkt;
613 /* locwindow is signed so we can cope with excess data. */
614 int locwindow, locmaxwin;
616 * remlocwin is the amount of local window that we think
617 * the remote end had available to it after it sent the
618 * last data packet or window adjust ack.
622 * These store the list of window adjusts that haven't
625 struct winadj *winadj_head, *winadj_tail;
626 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
630 struct ssh_agent_channel {
631 unsigned char *message;
632 unsigned char msglen[4];
633 unsigned lensofar, totallen;
635 struct ssh_x11_channel {
638 struct ssh_pfd_channel {
645 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
646 * use this structure in different ways, reflecting SSH-2's
647 * altogether saner approach to port forwarding.
649 * In SSH-1, you arrange a remote forwarding by sending the server
650 * the remote port number, and the local destination host:port.
651 * When a connection comes in, the server sends you back that
652 * host:port pair, and you connect to it. This is a ready-made
653 * security hole if you're not on the ball: a malicious server
654 * could send you back _any_ host:port pair, so if you trustingly
655 * connect to the address it gives you then you've just opened the
656 * entire inside of your corporate network just by connecting
657 * through it to a dodgy SSH server. Hence, we must store a list of
658 * host:port pairs we _are_ trying to forward to, and reject a
659 * connection request from the server if it's not in the list.
661 * In SSH-2, each side of the connection minds its own business and
662 * doesn't send unnecessary information to the other. You arrange a
663 * remote forwarding by sending the server just the remote port
664 * number. When a connection comes in, the server tells you which
665 * of its ports was connected to; and _you_ have to remember what
666 * local host:port pair went with that port number.
668 * Hence, in SSH-1 this structure is indexed by destination
669 * host:port pair, whereas in SSH-2 it is indexed by source port.
671 struct ssh_portfwd; /* forward declaration */
673 struct ssh_rportfwd {
674 unsigned sport, dport;
677 struct ssh_portfwd *pfrec;
679 #define free_rportfwd(pf) ( \
680 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
683 * Separately to the rportfwd tree (which is for looking up port
684 * open requests from the server), a tree of _these_ structures is
685 * used to keep track of all the currently open port forwardings,
686 * so that we can reconfigure in mid-session if the user requests
690 enum { DESTROY, KEEP, CREATE } status;
692 unsigned sport, dport;
695 struct ssh_rportfwd *remote;
699 #define free_portfwd(pf) ( \
700 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
701 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
704 long length; /* length of `data' actually used */
705 long forcepad; /* SSH-2: force padding to at least this length */
706 int type; /* only used for incoming packets */
707 unsigned long sequence; /* SSH-2 incoming sequence number */
708 unsigned char *data; /* allocated storage */
709 unsigned char *body; /* offset of payload within `data' */
710 long savedpos; /* temporary index into `data' (for strings) */
711 long maxlen; /* amount of storage allocated for `data' */
712 long encrypted_len; /* for SSH-2 total-size counting */
715 * State associated with packet logging
719 struct logblank_t *blanks;
722 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
723 struct Packet *pktin);
724 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
725 struct Packet *pktin);
726 static void ssh1_protocol_setup(Ssh ssh);
727 static void ssh2_protocol_setup(Ssh ssh);
728 static void ssh_size(void *handle, int width, int height);
729 static void ssh_special(void *handle, Telnet_Special);
730 static int ssh2_try_send(struct ssh_channel *c);
731 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
732 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
733 static void ssh2_set_window(struct ssh_channel *c, int newwin);
734 static int ssh_sendbuffer(void *handle);
735 static int ssh_do_close(Ssh ssh, int notify_exit);
736 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
737 static int ssh2_pkt_getbool(struct Packet *pkt);
738 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
739 static void ssh2_timer(void *ctx, long now);
740 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
741 struct Packet *pktin);
743 struct rdpkt1_state_tag {
744 long len, pad, biglen, to_read;
745 unsigned long realcrc, gotcrc;
749 struct Packet *pktin;
752 struct rdpkt2_state_tag {
753 long len, pad, payload, packetlen, maclen;
756 unsigned long incoming_sequence;
757 struct Packet *pktin;
760 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
761 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
763 struct queued_handler;
764 struct queued_handler {
766 chandler_fn_t handler;
768 struct queued_handler *next;
772 const struct plug_function_table *fn;
773 /* the above field _must_ be first in the structure */
783 unsigned char session_key[32];
785 int v1_remote_protoflags;
786 int v1_local_protoflags;
787 int agentfwd_enabled;
790 const struct ssh_cipher *cipher;
793 const struct ssh2_cipher *cscipher, *sccipher;
794 void *cs_cipher_ctx, *sc_cipher_ctx;
795 const struct ssh_mac *csmac, *scmac;
796 void *cs_mac_ctx, *sc_mac_ctx;
797 const struct ssh_compress *cscomp, *sccomp;
798 void *cs_comp_ctx, *sc_comp_ctx;
799 const struct ssh_kex *kex;
800 const struct ssh_signkey *hostkey;
801 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
802 int v2_session_id_len;
808 int echoing, editing;
812 int ospeed, ispeed; /* temporaries */
813 int term_width, term_height;
815 tree234 *channels; /* indexed by local id */
816 struct ssh_channel *mainchan; /* primary session channel */
817 int ncmode; /* is primary channel direct-tcpip? */
822 tree234 *rportfwds, *portfwds;
826 SSH_STATE_BEFORE_SIZE,
832 int size_needed, eof_needed;
834 struct Packet **queue;
835 int queuelen, queuesize;
837 unsigned char *deferred_send_data;
838 int deferred_len, deferred_size;
841 * Gross hack: pscp will try to start SFTP but fall back to
842 * scp1 if that fails. This variable is the means by which
843 * scp.c can reach into the SSH code and find out which one it
848 bufchain banner; /* accumulates banners during do_ssh2_authconn */
853 struct X11Display *x11disp;
856 int conn_throttle_count;
859 int v1_stdout_throttling;
860 unsigned long v2_outgoing_sequence;
862 int ssh1_rdpkt_crstate;
863 int ssh2_rdpkt_crstate;
864 int do_ssh_init_crstate;
865 int ssh_gotdata_crstate;
866 int do_ssh1_login_crstate;
867 int do_ssh1_connection_crstate;
868 int do_ssh2_transport_crstate;
869 int do_ssh2_authconn_crstate;
871 void *do_ssh_init_state;
872 void *do_ssh1_login_state;
873 void *do_ssh2_transport_state;
874 void *do_ssh2_authconn_state;
876 struct rdpkt1_state_tag rdpkt1_state;
877 struct rdpkt2_state_tag rdpkt2_state;
879 /* SSH-1 and SSH-2 use this for different things, but both use it */
880 int protocol_initial_phase_done;
882 void (*protocol) (Ssh ssh, void *vin, int inlen,
884 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
887 * We maintain a full _copy_ of a Config structure here, not
888 * merely a pointer to it. That way, when we're passed a new
889 * one for reconfiguration, we can check the differences and
890 * potentially reconfigure port forwardings etc in mid-session.
895 * Used to transfer data back from async callbacks.
897 void *agent_response;
898 int agent_response_len;
902 * The SSH connection can be set as `frozen', meaning we are
903 * not currently accepting incoming data from the network. This
904 * is slightly more serious than setting the _socket_ as
905 * frozen, because we may already have had data passed to us
906 * from the network which we need to delay processing until
907 * after the freeze is lifted, so we also need a bufchain to
911 bufchain queued_incoming_data;
914 * Dispatch table for packet types that we may have to deal
917 handler_fn_t packet_dispatch[256];
920 * Queues of one-off handler functions for success/failure
921 * indications from a request.
923 struct queued_handler *qhead, *qtail;
926 * This module deals with sending keepalives.
931 * Track incoming and outgoing data sizes and time, for
934 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
935 unsigned long max_data_size;
937 long next_rekey, last_rekey;
938 char *deferred_rekey_reason; /* points to STATIC string; don't free */
941 * Fully qualified host name, which we need if doing GSSAPI.
947 * GSSAPI libraries for this session.
949 struct ssh_gss_liblist *gsslibs;
953 #define logevent(s) logevent(ssh->frontend, s)
955 /* logevent, only printf-formatted. */
956 static void logeventf(Ssh ssh, const char *fmt, ...)
962 buf = dupvprintf(fmt, ap);
968 #define bombout(msg) \
970 char *text = dupprintf msg; \
971 ssh_do_close(ssh, FALSE); \
973 connection_fatal(ssh->frontend, "%s", text); \
977 /* Functions to leave bits out of the SSH packet log file. */
979 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
981 if (ssh->cfg.logomitpass)
982 pkt->logmode = blanktype;
985 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
987 if (ssh->cfg.logomitdata)
988 pkt->logmode = blanktype;
991 static void end_log_omission(Ssh ssh, struct Packet *pkt)
993 pkt->logmode = PKTLOG_EMIT;
996 /* Helper function for common bits of parsing cfg.ttymodes. */
997 static void parse_ttymodes(Ssh ssh, char *modes,
998 void (*do_mode)(void *data, char *mode, char *val),
1002 char *t = strchr(modes, '\t');
1003 char *m = snewn(t-modes+1, char);
1005 strncpy(m, modes, t-modes);
1008 val = get_ttymode(ssh->frontend, m);
1012 do_mode(data, m, val);
1015 modes += strlen(modes) + 1;
1019 static int ssh_channelcmp(void *av, void *bv)
1021 struct ssh_channel *a = (struct ssh_channel *) av;
1022 struct ssh_channel *b = (struct ssh_channel *) bv;
1023 if (a->localid < b->localid)
1025 if (a->localid > b->localid)
1029 static int ssh_channelfind(void *av, void *bv)
1031 unsigned *a = (unsigned *) av;
1032 struct ssh_channel *b = (struct ssh_channel *) bv;
1033 if (*a < b->localid)
1035 if (*a > b->localid)
1040 static int ssh_rportcmp_ssh1(void *av, void *bv)
1042 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1043 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1045 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1046 return i < 0 ? -1 : +1;
1047 if (a->dport > b->dport)
1049 if (a->dport < b->dport)
1054 static int ssh_rportcmp_ssh2(void *av, void *bv)
1056 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1057 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1059 if (a->sport > b->sport)
1061 if (a->sport < b->sport)
1067 * Special form of strcmp which can cope with NULL inputs. NULL is
1068 * defined to sort before even the empty string.
1070 static int nullstrcmp(const char *a, const char *b)
1072 if (a == NULL && b == NULL)
1078 return strcmp(a, b);
1081 static int ssh_portcmp(void *av, void *bv)
1083 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1084 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1086 if (a->type > b->type)
1088 if (a->type < b->type)
1090 if (a->addressfamily > b->addressfamily)
1092 if (a->addressfamily < b->addressfamily)
1094 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1095 return i < 0 ? -1 : +1;
1096 if (a->sport > b->sport)
1098 if (a->sport < b->sport)
1100 if (a->type != 'D') {
1101 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1102 return i < 0 ? -1 : +1;
1103 if (a->dport > b->dport)
1105 if (a->dport < b->dport)
1111 static int alloc_channel_id(Ssh ssh)
1113 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1114 unsigned low, high, mid;
1116 struct ssh_channel *c;
1119 * First-fit allocation of channel numbers: always pick the
1120 * lowest unused one. To do this, binary-search using the
1121 * counted B-tree to find the largest channel ID which is in a
1122 * contiguous sequence from the beginning. (Precisely
1123 * everything in that sequence must have ID equal to its tree
1124 * index plus CHANNEL_NUMBER_OFFSET.)
1126 tsize = count234(ssh->channels);
1130 while (high - low > 1) {
1131 mid = (high + low) / 2;
1132 c = index234(ssh->channels, mid);
1133 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1134 low = mid; /* this one is fine */
1136 high = mid; /* this one is past it */
1139 * Now low points to either -1, or the tree index of the
1140 * largest ID in the initial sequence.
1143 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1144 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1146 return low + 1 + CHANNEL_NUMBER_OFFSET;
1149 static void c_write_stderr(int trusted, const char *buf, int len)
1152 for (i = 0; i < len; i++)
1153 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1154 fputc(buf[i], stderr);
1157 static void c_write(Ssh ssh, const char *buf, int len)
1159 if (flags & FLAG_STDERR)
1160 c_write_stderr(1, buf, len);
1162 from_backend(ssh->frontend, 1, buf, len);
1165 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1167 if (flags & FLAG_STDERR)
1168 c_write_stderr(0, buf, len);
1170 from_backend_untrusted(ssh->frontend, buf, len);
1173 static void c_write_str(Ssh ssh, const char *buf)
1175 c_write(ssh, buf, strlen(buf));
1178 static void ssh_free_packet(struct Packet *pkt)
1183 static struct Packet *ssh_new_packet(void)
1185 struct Packet *pkt = snew(struct Packet);
1187 pkt->body = pkt->data = NULL;
1189 pkt->logmode = PKTLOG_EMIT;
1197 * Collect incoming data in the incoming packet buffer.
1198 * Decipher and verify the packet when it is completely read.
1199 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1200 * Update the *data and *datalen variables.
1201 * Return a Packet structure when a packet is completed.
1203 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1205 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1207 crBegin(ssh->ssh1_rdpkt_crstate);
1209 st->pktin = ssh_new_packet();
1211 st->pktin->type = 0;
1212 st->pktin->length = 0;
1214 for (st->i = st->len = 0; st->i < 4; st->i++) {
1215 while ((*datalen) == 0)
1217 st->len = (st->len << 8) + **data;
1218 (*data)++, (*datalen)--;
1221 st->pad = 8 - (st->len % 8);
1222 st->biglen = st->len + st->pad;
1223 st->pktin->length = st->len - 5;
1225 if (st->biglen < 0) {
1226 bombout(("Extremely large packet length from server suggests"
1227 " data stream corruption"));
1228 ssh_free_packet(st->pktin);
1232 st->pktin->maxlen = st->biglen;
1233 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1235 st->to_read = st->biglen;
1236 st->p = st->pktin->data;
1237 while (st->to_read > 0) {
1238 st->chunk = st->to_read;
1239 while ((*datalen) == 0)
1241 if (st->chunk > (*datalen))
1242 st->chunk = (*datalen);
1243 memcpy(st->p, *data, st->chunk);
1245 *datalen -= st->chunk;
1247 st->to_read -= st->chunk;
1250 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1251 st->biglen, NULL)) {
1252 bombout(("Network attack (CRC compensation) detected!"));
1253 ssh_free_packet(st->pktin);
1258 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1260 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1261 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1262 if (st->gotcrc != st->realcrc) {
1263 bombout(("Incorrect CRC received on packet"));
1264 ssh_free_packet(st->pktin);
1268 st->pktin->body = st->pktin->data + st->pad + 1;
1269 st->pktin->savedpos = 0;
1271 if (ssh->v1_compressing) {
1272 unsigned char *decompblk;
1274 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1275 st->pktin->body - 1, st->pktin->length + 1,
1276 &decompblk, &decomplen)) {
1277 bombout(("Zlib decompression encountered invalid data"));
1278 ssh_free_packet(st->pktin);
1282 if (st->pktin->maxlen < st->pad + decomplen) {
1283 st->pktin->maxlen = st->pad + decomplen;
1284 st->pktin->data = sresize(st->pktin->data,
1285 st->pktin->maxlen + APIEXTRA,
1287 st->pktin->body = st->pktin->data + st->pad + 1;
1290 memcpy(st->pktin->body - 1, decompblk, decomplen);
1292 st->pktin->length = decomplen - 1;
1295 st->pktin->type = st->pktin->body[-1];
1298 * Log incoming packet, possibly omitting sensitive fields.
1302 struct logblank_t blank;
1303 if (ssh->cfg.logomitdata) {
1304 int do_blank = FALSE, blank_prefix = 0;
1305 /* "Session data" packets - omit the data field */
1306 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1307 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1308 do_blank = TRUE; blank_prefix = 4;
1309 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1310 do_blank = TRUE; blank_prefix = 8;
1313 blank.offset = blank_prefix;
1314 blank.len = st->pktin->length;
1315 blank.type = PKTLOG_OMIT;
1319 log_packet(ssh->logctx,
1320 PKT_INCOMING, st->pktin->type,
1321 ssh1_pkt_type(st->pktin->type),
1322 st->pktin->body, st->pktin->length,
1323 nblanks, &blank, NULL);
1326 crFinish(st->pktin);
1329 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1331 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1333 crBegin(ssh->ssh2_rdpkt_crstate);
1335 st->pktin = ssh_new_packet();
1337 st->pktin->type = 0;
1338 st->pktin->length = 0;
1340 st->cipherblk = ssh->sccipher->blksize;
1343 if (st->cipherblk < 8)
1345 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1347 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1350 * When dealing with a CBC-mode cipher, we want to avoid the
1351 * possibility of an attacker's tweaking the ciphertext stream
1352 * so as to cause us to feed the same block to the block
1353 * cipher more than once and thus leak information
1354 * (VU#958563). The way we do this is not to take any
1355 * decisions on the basis of anything we've decrypted until
1356 * we've verified it with a MAC. That includes the packet
1357 * length, so we just read data and check the MAC repeatedly,
1358 * and when the MAC passes, see if the length we've got is
1362 /* May as well allocate the whole lot now. */
1363 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1366 /* Read an amount corresponding to the MAC. */
1367 for (st->i = 0; st->i < st->maclen; st->i++) {
1368 while ((*datalen) == 0)
1370 st->pktin->data[st->i] = *(*data)++;
1376 unsigned char seq[4];
1377 ssh->scmac->start(ssh->sc_mac_ctx);
1378 PUT_32BIT(seq, st->incoming_sequence);
1379 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1382 for (;;) { /* Once around this loop per cipher block. */
1383 /* Read another cipher-block's worth, and tack it onto the end. */
1384 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1385 while ((*datalen) == 0)
1387 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1390 /* Decrypt one more block (a little further back in the stream). */
1391 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1392 st->pktin->data + st->packetlen,
1394 /* Feed that block to the MAC. */
1395 ssh->scmac->bytes(ssh->sc_mac_ctx,
1396 st->pktin->data + st->packetlen, st->cipherblk);
1397 st->packetlen += st->cipherblk;
1398 /* See if that gives us a valid packet. */
1399 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1400 st->pktin->data + st->packetlen) &&
1401 (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen)
1403 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1404 bombout(("No valid incoming packet found"));
1405 ssh_free_packet(st->pktin);
1409 st->pktin->maxlen = st->packetlen + st->maclen;
1410 st->pktin->data = sresize(st->pktin->data,
1411 st->pktin->maxlen + APIEXTRA,
1414 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1417 * Acquire and decrypt the first block of the packet. This will
1418 * contain the length and padding details.
1420 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1421 while ((*datalen) == 0)
1423 st->pktin->data[st->i] = *(*data)++;
1428 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1429 st->pktin->data, st->cipherblk);
1432 * Now get the length figure.
1434 st->len = GET_32BIT(st->pktin->data);
1437 * _Completely_ silly lengths should be stomped on before they
1438 * do us any more damage.
1440 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1441 (st->len + 4) % st->cipherblk != 0) {
1442 bombout(("Incoming packet was garbled on decryption"));
1443 ssh_free_packet(st->pktin);
1448 * So now we can work out the total packet length.
1450 st->packetlen = st->len + 4;
1453 * Allocate memory for the rest of the packet.
1455 st->pktin->maxlen = st->packetlen + st->maclen;
1456 st->pktin->data = sresize(st->pktin->data,
1457 st->pktin->maxlen + APIEXTRA,
1461 * Read and decrypt the remainder of the packet.
1463 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1465 while ((*datalen) == 0)
1467 st->pktin->data[st->i] = *(*data)++;
1470 /* Decrypt everything _except_ the MAC. */
1472 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1473 st->pktin->data + st->cipherblk,
1474 st->packetlen - st->cipherblk);
1480 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1481 st->len + 4, st->incoming_sequence)) {
1482 bombout(("Incorrect MAC received on packet"));
1483 ssh_free_packet(st->pktin);
1487 /* Get and sanity-check the amount of random padding. */
1488 st->pad = st->pktin->data[4];
1489 if (st->pad < 4 || st->len - st->pad < 1) {
1490 bombout(("Invalid padding length on received packet"));
1491 ssh_free_packet(st->pktin);
1495 * This enables us to deduce the payload length.
1497 st->payload = st->len - st->pad - 1;
1499 st->pktin->length = st->payload + 5;
1500 st->pktin->encrypted_len = st->packetlen;
1502 st->pktin->sequence = st->incoming_sequence++;
1505 * Decompress packet payload.
1508 unsigned char *newpayload;
1511 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1512 st->pktin->data + 5, st->pktin->length - 5,
1513 &newpayload, &newlen)) {
1514 if (st->pktin->maxlen < newlen + 5) {
1515 st->pktin->maxlen = newlen + 5;
1516 st->pktin->data = sresize(st->pktin->data,
1517 st->pktin->maxlen + APIEXTRA,
1520 st->pktin->length = 5 + newlen;
1521 memcpy(st->pktin->data + 5, newpayload, newlen);
1526 st->pktin->savedpos = 6;
1527 st->pktin->body = st->pktin->data;
1528 st->pktin->type = st->pktin->data[5];
1531 * Log incoming packet, possibly omitting sensitive fields.
1535 struct logblank_t blank;
1536 if (ssh->cfg.logomitdata) {
1537 int do_blank = FALSE, blank_prefix = 0;
1538 /* "Session data" packets - omit the data field */
1539 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1540 do_blank = TRUE; blank_prefix = 8;
1541 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1542 do_blank = TRUE; blank_prefix = 12;
1545 blank.offset = blank_prefix;
1546 blank.len = (st->pktin->length-6) - blank_prefix;
1547 blank.type = PKTLOG_OMIT;
1551 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1552 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1554 st->pktin->data+6, st->pktin->length-6,
1555 nblanks, &blank, &st->pktin->sequence);
1558 crFinish(st->pktin);
1561 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1563 int pad, biglen, i, pktoffs;
1567 * XXX various versions of SC (including 8.8.4) screw up the
1568 * register allocation in this function and use the same register
1569 * (D6) for len and as a temporary, with predictable results. The
1570 * following sledgehammer prevents this.
1577 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1578 ssh1_pkt_type(pkt->data[12]),
1579 pkt->body, pkt->length - (pkt->body - pkt->data),
1580 pkt->nblanks, pkt->blanks, NULL);
1581 sfree(pkt->blanks); pkt->blanks = NULL;
1584 if (ssh->v1_compressing) {
1585 unsigned char *compblk;
1587 zlib_compress_block(ssh->cs_comp_ctx,
1588 pkt->data + 12, pkt->length - 12,
1589 &compblk, &complen);
1590 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1591 memcpy(pkt->data + 12, compblk, complen);
1593 pkt->length = complen + 12;
1596 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1598 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1599 pad = 8 - (len % 8);
1601 biglen = len + pad; /* len(padding+type+data+CRC) */
1603 for (i = pktoffs; i < 4+8; i++)
1604 pkt->data[i] = random_byte();
1605 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1606 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1607 PUT_32BIT(pkt->data + pktoffs, len);
1610 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1611 pkt->data + pktoffs + 4, biglen);
1613 if (offset_p) *offset_p = pktoffs;
1614 return biglen + 4; /* len(length+padding+type+data+CRC) */
1617 static int s_write(Ssh ssh, void *data, int len)
1620 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1622 return sk_write(ssh->s, (char *)data, len);
1625 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1627 int len, backlog, offset;
1628 len = s_wrpkt_prepare(ssh, pkt, &offset);
1629 backlog = s_write(ssh, pkt->data + offset, len);
1630 if (backlog > SSH_MAX_BACKLOG)
1631 ssh_throttle_all(ssh, 1, backlog);
1632 ssh_free_packet(pkt);
1635 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1638 len = s_wrpkt_prepare(ssh, pkt, &offset);
1639 if (ssh->deferred_len + len > ssh->deferred_size) {
1640 ssh->deferred_size = ssh->deferred_len + len + 128;
1641 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1645 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1646 pkt->data + offset, len);
1647 ssh->deferred_len += len;
1648 ssh_free_packet(pkt);
1652 * Construct a SSH-1 packet with the specified contents.
1653 * (This all-at-once interface used to be the only one, but now SSH-1
1654 * packets can also be constructed incrementally.)
1656 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1662 pkt = ssh1_pkt_init(pkttype);
1664 while ((argtype = va_arg(ap, int)) != PKT_END) {
1665 unsigned char *argp, argchar;
1667 unsigned long argint;
1670 /* Actual fields in the packet */
1672 argint = va_arg(ap, int);
1673 ssh_pkt_adduint32(pkt, argint);
1676 argchar = (unsigned char) va_arg(ap, int);
1677 ssh_pkt_addbyte(pkt, argchar);
1680 argp = va_arg(ap, unsigned char *);
1681 arglen = va_arg(ap, int);
1682 ssh_pkt_adddata(pkt, argp, arglen);
1685 sargp = va_arg(ap, char *);
1686 ssh_pkt_addstring(pkt, sargp);
1689 bn = va_arg(ap, Bignum);
1690 ssh1_pkt_addmp(pkt, bn);
1692 /* Tokens for modifications to packet logging */
1694 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1697 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1700 end_log_omission(ssh, pkt);
1708 static void send_packet(Ssh ssh, int pkttype, ...)
1712 va_start(ap, pkttype);
1713 pkt = construct_packet(ssh, pkttype, ap);
1718 static void defer_packet(Ssh ssh, int pkttype, ...)
1722 va_start(ap, pkttype);
1723 pkt = construct_packet(ssh, pkttype, ap);
1725 s_wrpkt_defer(ssh, pkt);
1728 static int ssh_versioncmp(char *a, char *b)
1731 unsigned long av, bv;
1733 av = strtoul(a, &ae, 10);
1734 bv = strtoul(b, &be, 10);
1736 return (av < bv ? -1 : +1);
1741 av = strtoul(ae, &ae, 10);
1742 bv = strtoul(be, &be, 10);
1744 return (av < bv ? -1 : +1);
1749 * Utility routines for putting an SSH-protocol `string' and
1750 * `uint32' into a hash state.
1752 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1754 unsigned char lenblk[4];
1755 PUT_32BIT(lenblk, len);
1756 h->bytes(s, lenblk, 4);
1757 h->bytes(s, str, len);
1760 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1762 unsigned char intblk[4];
1763 PUT_32BIT(intblk, i);
1764 h->bytes(s, intblk, 4);
1768 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1770 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1772 if (pkt->maxlen < length) {
1773 unsigned char *body = pkt->body;
1774 int offset = body ? body - pkt->data : 0;
1775 pkt->maxlen = length + 256;
1776 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1777 if (body) pkt->body = pkt->data + offset;
1780 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1782 if (pkt->logmode != PKTLOG_EMIT) {
1784 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1786 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1787 (pkt->body - pkt->data);
1788 pkt->blanks[pkt->nblanks-1].len = len;
1789 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1792 ssh_pkt_ensure(pkt, pkt->length);
1793 memcpy(pkt->data + pkt->length - len, data, len);
1795 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1797 ssh_pkt_adddata(pkt, &byte, 1);
1799 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1801 ssh_pkt_adddata(pkt, &value, 1);
1803 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1806 PUT_32BIT(x, value);
1807 ssh_pkt_adddata(pkt, x, 4);
1809 static void ssh_pkt_addstring_start(struct Packet *pkt)
1811 ssh_pkt_adduint32(pkt, 0);
1812 pkt->savedpos = pkt->length;
1814 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1816 ssh_pkt_adddata(pkt, data, strlen(data));
1817 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1819 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1821 ssh_pkt_adddata(pkt, data, len);
1822 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1824 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1826 ssh_pkt_addstring_start(pkt);
1827 ssh_pkt_addstring_str(pkt, data);
1829 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1831 int len = ssh1_bignum_length(b);
1832 unsigned char *data = snewn(len, unsigned char);
1833 (void) ssh1_write_bignum(data, b);
1834 ssh_pkt_adddata(pkt, data, len);
1837 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1840 int i, n = (bignum_bitcount(b) + 7) / 8;
1841 p = snewn(n + 1, unsigned char);
1843 for (i = 1; i <= n; i++)
1844 p[i] = bignum_byte(b, n - i);
1846 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1848 memmove(p, p + i, n + 1 - i);
1852 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1856 p = ssh2_mpint_fmt(b, &len);
1857 ssh_pkt_addstring_start(pkt);
1858 ssh_pkt_addstring_data(pkt, (char *)p, len);
1862 static struct Packet *ssh1_pkt_init(int pkt_type)
1864 struct Packet *pkt = ssh_new_packet();
1865 pkt->length = 4 + 8; /* space for length + max padding */
1866 ssh_pkt_addbyte(pkt, pkt_type);
1867 pkt->body = pkt->data + pkt->length;
1871 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1872 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1873 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1874 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1875 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1876 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1877 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1878 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1879 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1881 static struct Packet *ssh2_pkt_init(int pkt_type)
1883 struct Packet *pkt = ssh_new_packet();
1884 pkt->length = 5; /* space for packet length + padding length */
1886 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1887 pkt->body = pkt->data + pkt->length; /* after packet type */
1892 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1893 * put the MAC on it. Final packet, ready to be sent, is stored in
1894 * pkt->data. Total length is returned.
1896 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1898 int cipherblk, maclen, padding, i;
1901 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1902 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1903 pkt->body, pkt->length - (pkt->body - pkt->data),
1904 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
1905 sfree(pkt->blanks); pkt->blanks = NULL;
1909 * Compress packet payload.
1912 unsigned char *newpayload;
1915 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1917 &newpayload, &newlen)) {
1919 ssh2_pkt_adddata(pkt, newpayload, newlen);
1925 * Add padding. At least four bytes, and must also bring total
1926 * length (minus MAC) up to a multiple of the block size.
1927 * If pkt->forcepad is set, make sure the packet is at least that size
1930 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1931 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1933 if (pkt->length + padding < pkt->forcepad)
1934 padding = pkt->forcepad - pkt->length;
1936 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1937 assert(padding <= 255);
1938 maclen = ssh->csmac ? ssh->csmac->len : 0;
1939 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1940 pkt->data[4] = padding;
1941 for (i = 0; i < padding; i++)
1942 pkt->data[pkt->length + i] = random_byte();
1943 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1945 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1946 pkt->length + padding,
1947 ssh->v2_outgoing_sequence);
1948 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1951 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1952 pkt->data, pkt->length + padding);
1954 pkt->encrypted_len = pkt->length + padding;
1956 /* Ready-to-send packet starts at pkt->data. We return length. */
1957 return pkt->length + padding + maclen;
1961 * Routines called from the main SSH code to send packets. There
1962 * are quite a few of these, because we have two separate
1963 * mechanisms for delaying the sending of packets:
1965 * - In order to send an IGNORE message and a password message in
1966 * a single fixed-length blob, we require the ability to
1967 * concatenate the encrypted forms of those two packets _into_ a
1968 * single blob and then pass it to our <network.h> transport
1969 * layer in one go. Hence, there's a deferment mechanism which
1970 * works after packet encryption.
1972 * - In order to avoid sending any connection-layer messages
1973 * during repeat key exchange, we have to queue up any such
1974 * outgoing messages _before_ they are encrypted (and in
1975 * particular before they're allocated sequence numbers), and
1976 * then send them once we've finished.
1978 * I call these mechanisms `defer' and `queue' respectively, so as
1979 * to distinguish them reasonably easily.
1981 * The functions send_noqueue() and defer_noqueue() free the packet
1982 * structure they are passed. Every outgoing packet goes through
1983 * precisely one of these functions in its life; packets passed to
1984 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1985 * these or get queued, and then when the queue is later emptied
1986 * the packets are all passed to defer_noqueue().
1988 * When using a CBC-mode cipher, it's necessary to ensure that an
1989 * attacker can't provide data to be encrypted using an IV that they
1990 * know. We ensure this by prefixing each packet that might contain
1991 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1992 * mechanism, so in this case send_noqueue() ends up redirecting to
1993 * defer_noqueue(). If you don't like this inefficiency, don't use
1997 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1998 static void ssh_pkt_defersend(Ssh);
2001 * Send an SSH-2 packet immediately, without queuing or deferring.
2003 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2007 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2008 /* We need to send two packets, so use the deferral mechanism. */
2009 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2010 ssh_pkt_defersend(ssh);
2013 len = ssh2_pkt_construct(ssh, pkt);
2014 backlog = s_write(ssh, pkt->data, len);
2015 if (backlog > SSH_MAX_BACKLOG)
2016 ssh_throttle_all(ssh, 1, backlog);
2018 ssh->outgoing_data_size += pkt->encrypted_len;
2019 if (!ssh->kex_in_progress &&
2020 ssh->max_data_size != 0 &&
2021 ssh->outgoing_data_size > ssh->max_data_size)
2022 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2024 ssh_free_packet(pkt);
2028 * Defer an SSH-2 packet.
2030 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2033 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2034 ssh->deferred_len == 0 && !noignore &&
2035 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2037 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2038 * get encrypted with a known IV.
2040 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2041 ssh2_pkt_addstring_start(ipkt);
2042 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2044 len = ssh2_pkt_construct(ssh, pkt);
2045 if (ssh->deferred_len + len > ssh->deferred_size) {
2046 ssh->deferred_size = ssh->deferred_len + len + 128;
2047 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2051 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
2052 ssh->deferred_len += len;
2053 ssh->deferred_data_size += pkt->encrypted_len;
2054 ssh_free_packet(pkt);
2058 * Queue an SSH-2 packet.
2060 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2062 assert(ssh->queueing);
2064 if (ssh->queuelen >= ssh->queuesize) {
2065 ssh->queuesize = ssh->queuelen + 32;
2066 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2069 ssh->queue[ssh->queuelen++] = pkt;
2073 * Either queue or send a packet, depending on whether queueing is
2076 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2079 ssh2_pkt_queue(ssh, pkt);
2081 ssh2_pkt_send_noqueue(ssh, pkt);
2085 * Either queue or defer a packet, depending on whether queueing is
2088 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2091 ssh2_pkt_queue(ssh, pkt);
2093 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2097 * Send the whole deferred data block constructed by
2098 * ssh2_pkt_defer() or SSH-1's defer_packet().
2100 * The expected use of the defer mechanism is that you call
2101 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2102 * not currently queueing, this simply sets up deferred_send_data
2103 * and then sends it. If we _are_ currently queueing, the calls to
2104 * ssh2_pkt_defer() put the deferred packets on to the queue
2105 * instead, and therefore ssh_pkt_defersend() has no deferred data
2106 * to send. Hence, there's no need to make it conditional on
2109 static void ssh_pkt_defersend(Ssh ssh)
2112 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2113 ssh->deferred_len = ssh->deferred_size = 0;
2114 sfree(ssh->deferred_send_data);
2115 ssh->deferred_send_data = NULL;
2116 if (backlog > SSH_MAX_BACKLOG)
2117 ssh_throttle_all(ssh, 1, backlog);
2119 ssh->outgoing_data_size += ssh->deferred_data_size;
2120 if (!ssh->kex_in_progress &&
2121 ssh->max_data_size != 0 &&
2122 ssh->outgoing_data_size > ssh->max_data_size)
2123 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2124 ssh->deferred_data_size = 0;
2128 * Send a packet whose length needs to be disguised (typically
2129 * passwords or keyboard-interactive responses).
2131 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2137 * The simplest way to do this is to adjust the
2138 * variable-length padding field in the outgoing packet.
2140 * Currently compiled out, because some Cisco SSH servers
2141 * don't like excessively padded packets (bah, why's it
2144 pkt->forcepad = padsize;
2145 ssh2_pkt_send(ssh, pkt);
2150 * If we can't do that, however, an alternative approach is
2151 * to use the pkt_defer mechanism to bundle the packet
2152 * tightly together with an SSH_MSG_IGNORE such that their
2153 * combined length is a constant. So first we construct the
2154 * final form of this packet and defer its sending.
2156 ssh2_pkt_defer(ssh, pkt);
2159 * Now construct an SSH_MSG_IGNORE which includes a string
2160 * that's an exact multiple of the cipher block size. (If
2161 * the cipher is NULL so that the block size is
2162 * unavailable, we don't do this trick at all, because we
2163 * gain nothing by it.)
2165 if (ssh->cscipher &&
2166 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2169 stringlen = (256 - ssh->deferred_len);
2170 stringlen += ssh->cscipher->blksize - 1;
2171 stringlen -= (stringlen % ssh->cscipher->blksize);
2174 * Temporarily disable actual compression, so we
2175 * can guarantee to get this string exactly the
2176 * length we want it. The compression-disabling
2177 * routine should return an integer indicating how
2178 * many bytes we should adjust our string length
2182 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2184 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2185 ssh2_pkt_addstring_start(pkt);
2186 for (i = 0; i < stringlen; i++) {
2187 char c = (char) random_byte();
2188 ssh2_pkt_addstring_data(pkt, &c, 1);
2190 ssh2_pkt_defer(ssh, pkt);
2192 ssh_pkt_defersend(ssh);
2197 * Send all queued SSH-2 packets. We send them by means of
2198 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2199 * packets that needed to be lumped together.
2201 static void ssh2_pkt_queuesend(Ssh ssh)
2205 assert(!ssh->queueing);
2207 for (i = 0; i < ssh->queuelen; i++)
2208 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2211 ssh_pkt_defersend(ssh);
2215 void bndebug(char *string, Bignum b)
2219 p = ssh2_mpint_fmt(b, &len);
2220 debug(("%s", string));
2221 for (i = 0; i < len; i++)
2222 debug((" %02x", p[i]));
2228 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2232 p = ssh2_mpint_fmt(b, &len);
2233 hash_string(h, s, p, len);
2238 * Packet decode functions for both SSH-1 and SSH-2.
2240 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2242 unsigned long value;
2243 if (pkt->length - pkt->savedpos < 4)
2244 return 0; /* arrgh, no way to decline (FIXME?) */
2245 value = GET_32BIT(pkt->body + pkt->savedpos);
2249 static int ssh2_pkt_getbool(struct Packet *pkt)
2251 unsigned long value;
2252 if (pkt->length - pkt->savedpos < 1)
2253 return 0; /* arrgh, no way to decline (FIXME?) */
2254 value = pkt->body[pkt->savedpos] != 0;
2258 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2263 if (pkt->length - pkt->savedpos < 4)
2265 len = GET_32BIT(pkt->body + pkt->savedpos);
2270 if (pkt->length - pkt->savedpos < *length)
2272 *p = (char *)(pkt->body + pkt->savedpos);
2273 pkt->savedpos += *length;
2275 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2277 if (pkt->length - pkt->savedpos < length)
2279 pkt->savedpos += length;
2280 return pkt->body + (pkt->savedpos - length);
2282 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2283 unsigned char **keystr)
2287 j = makekey(pkt->body + pkt->savedpos,
2288 pkt->length - pkt->savedpos,
2295 assert(pkt->savedpos < pkt->length);
2299 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2304 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2305 pkt->length - pkt->savedpos, &b);
2313 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2319 ssh_pkt_getstring(pkt, &p, &length);
2324 b = bignum_from_bytes((unsigned char *)p, length);
2329 * Helper function to add an SSH-2 signature blob to a packet.
2330 * Expects to be shown the public key blob as well as the signature
2331 * blob. Normally works just like ssh2_pkt_addstring, but will
2332 * fiddle with the signature packet if necessary for
2333 * BUG_SSH2_RSA_PADDING.
2335 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2336 void *pkblob_v, int pkblob_len,
2337 void *sigblob_v, int sigblob_len)
2339 unsigned char *pkblob = (unsigned char *)pkblob_v;
2340 unsigned char *sigblob = (unsigned char *)sigblob_v;
2342 /* dmemdump(pkblob, pkblob_len); */
2343 /* dmemdump(sigblob, sigblob_len); */
2346 * See if this is in fact an ssh-rsa signature and a buggy
2347 * server; otherwise we can just do this the easy way.
2349 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2350 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2351 int pos, len, siglen;
2354 * Find the byte length of the modulus.
2357 pos = 4+7; /* skip over "ssh-rsa" */
2358 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2359 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2360 pos += 4; /* find modulus itself */
2361 while (len > 0 && pkblob[pos] == 0)
2363 /* debug(("modulus length is %d\n", len)); */
2366 * Now find the signature integer.
2368 pos = 4+7; /* skip over "ssh-rsa" */
2369 siglen = GET_32BIT(sigblob+pos);
2370 /* debug(("signature length is %d\n", siglen)); */
2372 if (len != siglen) {
2373 unsigned char newlen[4];
2374 ssh2_pkt_addstring_start(pkt);
2375 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2376 /* dmemdump(sigblob, pos); */
2377 pos += 4; /* point to start of actual sig */
2378 PUT_32BIT(newlen, len);
2379 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2380 /* dmemdump(newlen, 4); */
2382 while (len-- > siglen) {
2383 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2384 /* dmemdump(newlen, 1); */
2386 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2387 /* dmemdump(sigblob+pos, siglen); */
2391 /* Otherwise fall through and do it the easy way. */
2394 ssh2_pkt_addstring_start(pkt);
2395 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2399 * Examine the remote side's version string and compare it against
2400 * a list of known buggy implementations.
2402 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2404 char *imp; /* pointer to implementation part */
2406 imp += strcspn(imp, "-");
2408 imp += strcspn(imp, "-");
2411 ssh->remote_bugs = 0;
2414 * General notes on server version strings:
2415 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2416 * here -- in particular, we've heard of one that's perfectly happy
2417 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2418 * so we can't distinguish them.
2420 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2421 (ssh->cfg.sshbug_ignore1 == AUTO &&
2422 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2423 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2424 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2425 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2427 * These versions don't support SSH1_MSG_IGNORE, so we have
2428 * to use a different defence against password length
2431 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2432 logevent("We believe remote version has SSH-1 ignore bug");
2435 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2436 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2437 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2439 * These versions need a plain password sent; they can't
2440 * handle having a null and a random length of data after
2443 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2444 logevent("We believe remote version needs a plain SSH-1 password");
2447 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2448 (ssh->cfg.sshbug_rsa1 == AUTO &&
2449 (!strcmp(imp, "Cisco-1.25")))) {
2451 * These versions apparently have no clue whatever about
2452 * RSA authentication and will panic and die if they see
2453 * an AUTH_RSA message.
2455 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2456 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2459 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2460 (ssh->cfg.sshbug_hmac2 == AUTO &&
2461 !wc_match("* VShell", imp) &&
2462 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2463 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2464 wc_match("2.1 *", imp)))) {
2466 * These versions have the HMAC bug.
2468 ssh->remote_bugs |= BUG_SSH2_HMAC;
2469 logevent("We believe remote version has SSH-2 HMAC bug");
2472 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2473 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2474 !wc_match("* VShell", imp) &&
2475 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2477 * These versions have the key-derivation bug (failing to
2478 * include the literal shared secret in the hashes that
2479 * generate the keys).
2481 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2482 logevent("We believe remote version has SSH-2 key-derivation bug");
2485 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2486 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2487 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2488 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2490 * These versions have the SSH-2 RSA padding bug.
2492 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2493 logevent("We believe remote version has SSH-2 RSA padding bug");
2496 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2497 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2498 wc_match("OpenSSH_2.[0-2]*", imp))) {
2500 * These versions have the SSH-2 session-ID bug in
2501 * public-key authentication.
2503 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2504 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2507 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2508 (ssh->cfg.sshbug_rekey2 == AUTO &&
2509 (wc_match("DigiSSH_2.0", imp) ||
2510 wc_match("OpenSSH_2.[0-4]*", imp) ||
2511 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2512 wc_match("Sun_SSH_1.0", imp) ||
2513 wc_match("Sun_SSH_1.0.1", imp) ||
2514 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2515 wc_match("WeOnlyDo-*", imp)))) {
2517 * These versions have the SSH-2 rekey bug.
2519 ssh->remote_bugs |= BUG_SSH2_REKEY;
2520 logevent("We believe remote version has SSH-2 rekey bug");
2523 if (ssh->cfg.sshbug_maxpkt2 == FORCE_ON ||
2524 (ssh->cfg.sshbug_maxpkt2 == AUTO &&
2525 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2526 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2528 * This version ignores our makpkt and needs to be throttled.
2530 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2531 logevent("We believe remote version ignores SSH-2 maximum packet size");
2534 if (ssh->cfg.sshbug_ignore2 == FORCE_ON) {
2536 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2537 * none detected automatically.
2539 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2540 logevent("We believe remote version has SSH-2 ignore bug");
2545 * The `software version' part of an SSH version string is required
2546 * to contain no spaces or minus signs.
2548 static void ssh_fix_verstring(char *str)
2550 /* Eat "SSH-<protoversion>-". */
2551 assert(*str == 'S'); str++;
2552 assert(*str == 'S'); str++;
2553 assert(*str == 'H'); str++;
2554 assert(*str == '-'); str++;
2555 while (*str && *str != '-') str++;
2556 assert(*str == '-'); str++;
2558 /* Convert minus signs and spaces in the remaining string into
2561 if (*str == '-' || *str == ' ')
2568 * Send an appropriate SSH version string.
2570 static void ssh_send_verstring(Ssh ssh, char *svers)
2574 if (ssh->version == 2) {
2576 * Construct a v2 version string.
2578 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2581 * Construct a v1 version string.
2583 verstring = dupprintf("SSH-%s-%s\012",
2584 (ssh_versioncmp(svers, "1.5") <= 0 ?
2589 ssh_fix_verstring(verstring);
2591 if (ssh->version == 2) {
2594 * Record our version string.
2596 len = strcspn(verstring, "\015\012");
2597 ssh->v_c = snewn(len + 1, char);
2598 memcpy(ssh->v_c, verstring, len);
2602 logeventf(ssh, "We claim version: %.*s",
2603 strcspn(verstring, "\015\012"), verstring);
2604 s_write(ssh, verstring, strlen(verstring));
2608 static int do_ssh_init(Ssh ssh, unsigned char c)
2610 struct do_ssh_init_state {
2618 crState(do_ssh_init_state);
2620 crBegin(ssh->do_ssh_init_crstate);
2622 /* Search for a line beginning with the string "SSH-" in the input. */
2624 if (c != 'S') goto no;
2626 if (c != 'S') goto no;
2628 if (c != 'H') goto no;
2630 if (c != '-') goto no;
2639 s->vstring = snewn(s->vstrsize, char);
2640 strcpy(s->vstring, "SSH-");
2644 crReturn(1); /* get another char */
2645 if (s->vslen >= s->vstrsize - 1) {
2647 s->vstring = sresize(s->vstring, s->vstrsize, char);
2649 s->vstring[s->vslen++] = c;
2652 s->version[s->i] = '\0';
2654 } else if (s->i < sizeof(s->version) - 1)
2655 s->version[s->i++] = c;
2656 } else if (c == '\012')
2660 ssh->agentfwd_enabled = FALSE;
2661 ssh->rdpkt2_state.incoming_sequence = 0;
2663 s->vstring[s->vslen] = 0;
2664 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2665 logeventf(ssh, "Server version: %s", s->vstring);
2666 ssh_detect_bugs(ssh, s->vstring);
2669 * Decide which SSH protocol version to support.
2672 /* Anything strictly below "2.0" means protocol 1 is supported. */
2673 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2674 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2675 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2677 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2678 bombout(("SSH protocol version 1 required by user but not provided by server"));
2681 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2682 bombout(("SSH protocol version 2 required by user but not provided by server"));
2686 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1))
2691 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2693 /* Send the version string, if we haven't already */
2694 if (ssh->cfg.sshprot != 3)
2695 ssh_send_verstring(ssh, s->version);
2697 if (ssh->version == 2) {
2700 * Record their version string.
2702 len = strcspn(s->vstring, "\015\012");
2703 ssh->v_s = snewn(len + 1, char);
2704 memcpy(ssh->v_s, s->vstring, len);
2708 * Initialise SSH-2 protocol.
2710 ssh->protocol = ssh2_protocol;
2711 ssh2_protocol_setup(ssh);
2712 ssh->s_rdpkt = ssh2_rdpkt;
2715 * Initialise SSH-1 protocol.
2717 ssh->protocol = ssh1_protocol;
2718 ssh1_protocol_setup(ssh);
2719 ssh->s_rdpkt = ssh1_rdpkt;
2721 if (ssh->version == 2)
2722 do_ssh2_transport(ssh, NULL, -1, NULL);
2724 update_specials_menu(ssh->frontend);
2725 ssh->state = SSH_STATE_BEFORE_SIZE;
2726 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2733 static void ssh_process_incoming_data(Ssh ssh,
2734 unsigned char **data, int *datalen)
2736 struct Packet *pktin;
2738 pktin = ssh->s_rdpkt(ssh, data, datalen);
2740 ssh->protocol(ssh, NULL, 0, pktin);
2741 ssh_free_packet(pktin);
2745 static void ssh_queue_incoming_data(Ssh ssh,
2746 unsigned char **data, int *datalen)
2748 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2753 static void ssh_process_queued_incoming_data(Ssh ssh)
2756 unsigned char *data;
2759 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2760 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2764 while (!ssh->frozen && len > 0)
2765 ssh_process_incoming_data(ssh, &data, &len);
2768 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2772 static void ssh_set_frozen(Ssh ssh, int frozen)
2775 sk_set_frozen(ssh->s, frozen);
2776 ssh->frozen = frozen;
2779 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2781 /* Log raw data, if we're in that mode. */
2783 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2786 crBegin(ssh->ssh_gotdata_crstate);
2789 * To begin with, feed the characters one by one to the
2790 * protocol initialisation / selection function do_ssh_init().
2791 * When that returns 0, we're done with the initial greeting
2792 * exchange and can move on to packet discipline.
2795 int ret; /* need not be kept across crReturn */
2797 crReturnV; /* more data please */
2798 ret = do_ssh_init(ssh, *data);
2806 * We emerge from that loop when the initial negotiation is
2807 * over and we have selected an s_rdpkt function. Now pass
2808 * everything to s_rdpkt, and then pass the resulting packets
2809 * to the proper protocol handler.
2813 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2815 ssh_queue_incoming_data(ssh, &data, &datalen);
2816 /* This uses up all data and cannot cause anything interesting
2817 * to happen; indeed, for anything to happen at all, we must
2818 * return, so break out. */
2820 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2821 /* This uses up some or all data, and may freeze the
2823 ssh_process_queued_incoming_data(ssh);
2825 /* This uses up some or all data, and may freeze the
2827 ssh_process_incoming_data(ssh, &data, &datalen);
2829 /* FIXME this is probably EBW. */
2830 if (ssh->state == SSH_STATE_CLOSED)
2833 /* We're out of data. Go and get some more. */
2839 static int ssh_do_close(Ssh ssh, int notify_exit)
2842 struct ssh_channel *c;
2844 ssh->state = SSH_STATE_CLOSED;
2845 expire_timer_context(ssh);
2850 notify_remote_exit(ssh->frontend);
2855 * Now we must shut down any port- and X-forwarded channels going
2856 * through this connection.
2858 if (ssh->channels) {
2859 while (NULL != (c = index234(ssh->channels, 0))) {
2862 x11_close(c->u.x11.s);
2865 case CHAN_SOCKDATA_DORMANT:
2866 pfd_close(c->u.pfd.s);
2869 del234(ssh->channels, c); /* moving next one to index 0 */
2870 if (ssh->version == 2)
2871 bufchain_clear(&c->v.v2.outbuffer);
2876 * Go through port-forwardings, and close any associated
2877 * listening sockets.
2879 if (ssh->portfwds) {
2880 struct ssh_portfwd *pf;
2881 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2882 /* Dispose of any listening socket. */
2884 pfd_terminate(pf->local);
2885 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2888 freetree234(ssh->portfwds);
2889 ssh->portfwds = NULL;
2895 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2896 const char *error_msg, int error_code)
2898 Ssh ssh = (Ssh) plug;
2899 char addrbuf[256], *msg;
2901 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2904 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2906 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2912 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2915 Ssh ssh = (Ssh) plug;
2916 int need_notify = ssh_do_close(ssh, FALSE);
2919 if (!ssh->close_expected)
2920 error_msg = "Server unexpectedly closed network connection";
2922 error_msg = "Server closed network connection";
2925 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2929 notify_remote_exit(ssh->frontend);
2932 logevent(error_msg);
2933 if (!ssh->close_expected || !ssh->clean_exit)
2934 connection_fatal(ssh->frontend, "%s", error_msg);
2938 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2940 Ssh ssh = (Ssh) plug;
2941 ssh_gotdata(ssh, (unsigned char *)data, len);
2942 if (ssh->state == SSH_STATE_CLOSED) {
2943 ssh_do_close(ssh, TRUE);
2949 static void ssh_sent(Plug plug, int bufsize)
2951 Ssh ssh = (Ssh) plug;
2953 * If the send backlog on the SSH socket itself clears, we
2954 * should unthrottle the whole world if it was throttled.
2956 if (bufsize < SSH_MAX_BACKLOG)
2957 ssh_throttle_all(ssh, 0, bufsize);
2961 * Connect to specified host and port.
2962 * Returns an error message, or NULL on success.
2963 * Also places the canonical host name into `realhost'. It must be
2964 * freed by the caller.
2966 static const char *connect_to_host(Ssh ssh, char *host, int port,
2967 char **realhost, int nodelay, int keepalive)
2969 static const struct plug_function_table fn_table = {
2980 if (*ssh->cfg.loghost) {
2983 ssh->savedhost = dupstr(ssh->cfg.loghost);
2984 ssh->savedport = 22; /* default ssh port */
2987 * A colon suffix on savedhost also lets us affect
2990 * (FIXME: do something about IPv6 address literals here.)
2992 colon = strrchr(ssh->savedhost, ':');
2996 ssh->savedport = atoi(colon);
2999 ssh->savedhost = dupstr(host);
3001 port = 22; /* default ssh port */
3002 ssh->savedport = port;
3008 logeventf(ssh, "Looking up host \"%s\"%s", host,
3009 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3010 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3011 addr = name_lookup(host, port, realhost, &ssh->cfg,
3012 ssh->cfg.addressfamily);
3013 if ((err = sk_addr_error(addr)) != NULL) {
3017 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3022 ssh->fn = &fn_table;
3023 ssh->s = new_connection(addr, *realhost, port,
3024 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
3025 if ((err = sk_socket_error(ssh->s)) != NULL) {
3027 notify_remote_exit(ssh->frontend);
3032 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3033 * send the version string too.
3035 if (ssh->cfg.sshprot == 0)
3037 if (ssh->cfg.sshprot == 3) {
3039 ssh_send_verstring(ssh, NULL);
3043 * loghost, if configured, overrides realhost.
3045 if (*ssh->cfg.loghost) {
3047 *realhost = dupstr(ssh->cfg.loghost);
3054 * Throttle or unthrottle the SSH connection.
3056 static void ssh_throttle_conn(Ssh ssh, int adjust)
3058 int old_count = ssh->conn_throttle_count;
3059 ssh->conn_throttle_count += adjust;
3060 assert(ssh->conn_throttle_count >= 0);
3061 if (ssh->conn_throttle_count && !old_count) {
3062 ssh_set_frozen(ssh, 1);
3063 } else if (!ssh->conn_throttle_count && old_count) {
3064 ssh_set_frozen(ssh, 0);
3069 * Throttle or unthrottle _all_ local data streams (for when sends
3070 * on the SSH connection itself back up).
3072 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3075 struct ssh_channel *c;
3077 if (enable == ssh->throttled_all)
3079 ssh->throttled_all = enable;
3080 ssh->overall_bufsize = bufsize;
3083 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3085 case CHAN_MAINSESSION:
3087 * This is treated separately, outside the switch.
3091 x11_override_throttle(c->u.x11.s, enable);
3094 /* Agent channels require no buffer management. */
3097 pfd_override_throttle(c->u.pfd.s, enable);
3103 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3105 Ssh ssh = (Ssh) sshv;
3107 ssh->agent_response = reply;
3108 ssh->agent_response_len = replylen;
3110 if (ssh->version == 1)
3111 do_ssh1_login(ssh, NULL, -1, NULL);
3113 do_ssh2_authconn(ssh, NULL, -1, NULL);
3116 static void ssh_dialog_callback(void *sshv, int ret)
3118 Ssh ssh = (Ssh) sshv;
3120 ssh->user_response = ret;
3122 if (ssh->version == 1)
3123 do_ssh1_login(ssh, NULL, -1, NULL);
3125 do_ssh2_transport(ssh, NULL, -1, NULL);
3128 * This may have unfrozen the SSH connection, so do a
3131 ssh_process_queued_incoming_data(ssh);
3134 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3136 struct ssh_channel *c = (struct ssh_channel *)cv;
3138 void *sentreply = reply;
3141 /* Fake SSH_AGENT_FAILURE. */
3142 sentreply = "\0\0\0\1\5";
3145 if (ssh->version == 2) {
3146 ssh2_add_channel_data(c, sentreply, replylen);
3149 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3150 PKT_INT, c->remoteid,
3153 PKT_DATA, sentreply, replylen,
3162 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3163 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3164 * => log `wire_reason'.
3166 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3167 int code, int clean_exit)
3171 client_reason = wire_reason;
3173 error = dupprintf("Disconnected: %s", client_reason);
3175 error = dupstr("Disconnected");
3177 if (ssh->version == 1) {
3178 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3180 } else if (ssh->version == 2) {
3181 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3182 ssh2_pkt_adduint32(pktout, code);
3183 ssh2_pkt_addstring(pktout, wire_reason);
3184 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3185 ssh2_pkt_send_noqueue(ssh, pktout);
3188 ssh->close_expected = TRUE;
3189 ssh->clean_exit = clean_exit;
3190 ssh_closing((Plug)ssh, error, 0, 0);
3195 * Handle the key exchange and user authentication phases.
3197 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3198 struct Packet *pktin)
3201 unsigned char cookie[8], *ptr;
3202 struct RSAKey servkey, hostkey;
3203 struct MD5Context md5c;
3204 struct do_ssh1_login_state {
3206 unsigned char *rsabuf, *keystr1, *keystr2;
3207 unsigned long supported_ciphers_mask, supported_auths_mask;
3208 int tried_publickey, tried_agent;
3209 int tis_auth_refused, ccard_auth_refused;
3210 unsigned char session_id[16];
3213 void *publickey_blob;
3214 int publickey_bloblen;
3215 char *publickey_comment;
3216 int publickey_encrypted;
3217 prompts_t *cur_prompt;
3220 unsigned char request[5], *response, *p;
3230 crState(do_ssh1_login_state);
3232 crBegin(ssh->do_ssh1_login_crstate);
3237 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3238 bombout(("Public key packet not received"));
3242 logevent("Received public keys");
3244 ptr = ssh_pkt_getdata(pktin, 8);
3246 bombout(("SSH-1 public key packet stopped before random cookie"));
3249 memcpy(cookie, ptr, 8);
3251 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3252 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
3253 bombout(("Failed to read SSH-1 public keys from public key packet"));
3258 * Log the host key fingerprint.
3262 logevent("Host key fingerprint is:");
3263 strcpy(logmsg, " ");
3264 hostkey.comment = NULL;
3265 rsa_fingerprint(logmsg + strlen(logmsg),
3266 sizeof(logmsg) - strlen(logmsg), &hostkey);
3270 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3271 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3272 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3273 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3274 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3276 ssh->v1_local_protoflags =
3277 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3278 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3281 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3282 MD5Update(&md5c, s->keystr1, servkey.bytes);
3283 MD5Update(&md5c, cookie, 8);
3284 MD5Final(s->session_id, &md5c);
3286 for (i = 0; i < 32; i++)
3287 ssh->session_key[i] = random_byte();
3290 * Verify that the `bits' and `bytes' parameters match.
3292 if (hostkey.bits > hostkey.bytes * 8 ||
3293 servkey.bits > servkey.bytes * 8) {
3294 bombout(("SSH-1 public keys were badly formatted"));
3298 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
3300 s->rsabuf = snewn(s->len, unsigned char);
3303 * Verify the host key.
3307 * First format the key into a string.
3309 int len = rsastr_len(&hostkey);
3310 char fingerprint[100];
3311 char *keystr = snewn(len, char);
3312 rsastr_fmt(keystr, &hostkey);
3313 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3315 ssh_set_frozen(ssh, 1);
3316 s->dlgret = verify_ssh_host_key(ssh->frontend,
3317 ssh->savedhost, ssh->savedport,
3318 "rsa", keystr, fingerprint,
3319 ssh_dialog_callback, ssh);
3321 if (s->dlgret < 0) {
3325 bombout(("Unexpected data from server while waiting"
3326 " for user host key response"));
3329 } while (pktin || inlen > 0);
3330 s->dlgret = ssh->user_response;
3332 ssh_set_frozen(ssh, 0);
3334 if (s->dlgret == 0) {
3335 ssh_disconnect(ssh, "User aborted at host key verification",
3341 for (i = 0; i < 32; i++) {
3342 s->rsabuf[i] = ssh->session_key[i];
3344 s->rsabuf[i] ^= s->session_id[i];
3347 if (hostkey.bytes > servkey.bytes) {
3348 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3350 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3352 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3354 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3357 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3361 logevent("Encrypted session key");
3364 int cipher_chosen = 0, warn = 0;
3365 char *cipher_string = NULL;
3367 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3368 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3369 if (next_cipher == CIPHER_WARN) {
3370 /* If/when we choose a cipher, warn about it */
3372 } else if (next_cipher == CIPHER_AES) {
3373 /* XXX Probably don't need to mention this. */
3374 logevent("AES not supported in SSH-1, skipping");
3376 switch (next_cipher) {
3377 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3378 cipher_string = "3DES"; break;
3379 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3380 cipher_string = "Blowfish"; break;
3381 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3382 cipher_string = "single-DES"; break;
3384 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3388 if (!cipher_chosen) {
3389 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3390 bombout(("Server violates SSH-1 protocol by not "
3391 "supporting 3DES encryption"));
3393 /* shouldn't happen */
3394 bombout(("No supported ciphers found"));
3398 /* Warn about chosen cipher if necessary. */
3400 ssh_set_frozen(ssh, 1);
3401 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3402 ssh_dialog_callback, ssh);
3403 if (s->dlgret < 0) {
3407 bombout(("Unexpected data from server while waiting"
3408 " for user response"));
3411 } while (pktin || inlen > 0);
3412 s->dlgret = ssh->user_response;
3414 ssh_set_frozen(ssh, 0);
3415 if (s->dlgret == 0) {
3416 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3423 switch (s->cipher_type) {
3424 case SSH_CIPHER_3DES:
3425 logevent("Using 3DES encryption");
3427 case SSH_CIPHER_DES:
3428 logevent("Using single-DES encryption");
3430 case SSH_CIPHER_BLOWFISH:
3431 logevent("Using Blowfish encryption");
3435 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3436 PKT_CHAR, s->cipher_type,
3437 PKT_DATA, cookie, 8,
3438 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3439 PKT_DATA, s->rsabuf, s->len,
3440 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3442 logevent("Trying to enable encryption...");
3446 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3447 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3449 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3450 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3451 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3453 ssh->crcda_ctx = crcda_make_context();
3454 logevent("Installing CRC compensation attack detector");
3456 if (servkey.modulus) {
3457 sfree(servkey.modulus);
3458 servkey.modulus = NULL;
3460 if (servkey.exponent) {
3461 sfree(servkey.exponent);
3462 servkey.exponent = NULL;
3464 if (hostkey.modulus) {
3465 sfree(hostkey.modulus);
3466 hostkey.modulus = NULL;
3468 if (hostkey.exponent) {
3469 sfree(hostkey.exponent);
3470 hostkey.exponent = NULL;
3474 if (pktin->type != SSH1_SMSG_SUCCESS) {
3475 bombout(("Encryption not successfully enabled"));
3479 logevent("Successfully started encryption");
3481 fflush(stdout); /* FIXME eh? */
3483 if (!get_remote_username(&ssh->cfg, s->username,
3484 sizeof(s->username))) {
3485 int ret; /* need not be kept over crReturn */
3486 s->cur_prompt = new_prompts(ssh->frontend);
3487 s->cur_prompt->to_server = TRUE;
3488 s->cur_prompt->name = dupstr("SSH login name");
3489 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
3490 lenof(s->username));
3491 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3494 crWaitUntil(!pktin);
3495 ret = get_userpass_input(s->cur_prompt, in, inlen);
3500 * Failed to get a username. Terminate.
3502 free_prompts(s->cur_prompt);
3503 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3506 memcpy(s->username, s->cur_prompt->prompts[0]->result,
3507 lenof(s->username));
3508 free_prompts(s->cur_prompt);
3511 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3513 char *userlog = dupprintf("Sent username \"%s\"", s->username);
3515 if (flags & FLAG_INTERACTIVE &&
3516 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3517 c_write_str(ssh, userlog);
3518 c_write_str(ssh, "\r\n");
3526 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3527 /* We must not attempt PK auth. Pretend we've already tried it. */
3528 s->tried_publickey = s->tried_agent = 1;
3530 s->tried_publickey = s->tried_agent = 0;
3532 s->tis_auth_refused = s->ccard_auth_refused = 0;
3534 * Load the public half of any configured keyfile for later use.
3536 if (!filename_is_null(ssh->cfg.keyfile)) {
3538 logeventf(ssh, "Reading private key file \"%.150s\"",
3539 filename_to_str(&ssh->cfg.keyfile));
3540 keytype = key_type(&ssh->cfg.keyfile);
3541 if (keytype == SSH_KEYTYPE_SSH1) {
3543 if (rsakey_pubblob(&ssh->cfg.keyfile,
3544 &s->publickey_blob, &s->publickey_bloblen,
3545 &s->publickey_comment, &error)) {
3546 s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
3550 logeventf(ssh, "Unable to load private key (%s)", error);
3551 msgbuf = dupprintf("Unable to load private key file "
3552 "\"%.150s\" (%s)\r\n",
3553 filename_to_str(&ssh->cfg.keyfile),
3555 c_write_str(ssh, msgbuf);
3557 s->publickey_blob = NULL;
3561 logeventf(ssh, "Unable to use this key file (%s)",
3562 key_type_to_str(keytype));
3563 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3565 filename_to_str(&ssh->cfg.keyfile),
3566 key_type_to_str(keytype));
3567 c_write_str(ssh, msgbuf);
3569 s->publickey_blob = NULL;
3572 s->publickey_blob = NULL;
3574 while (pktin->type == SSH1_SMSG_FAILURE) {
3575 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3577 if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
3579 * Attempt RSA authentication using Pageant.
3585 logevent("Pageant is running. Requesting keys.");
3587 /* Request the keys held by the agent. */
3588 PUT_32BIT(s->request, 1);
3589 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3590 if (!agent_query(s->request, 5, &r, &s->responselen,
3591 ssh_agent_callback, ssh)) {
3595 bombout(("Unexpected data from server while waiting"
3596 " for agent response"));
3599 } while (pktin || inlen > 0);
3600 r = ssh->agent_response;
3601 s->responselen = ssh->agent_response_len;
3603 s->response = (unsigned char *) r;
3604 if (s->response && s->responselen >= 5 &&
3605 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3606 s->p = s->response + 5;
3607 s->nkeys = GET_32BIT(s->p);
3609 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3610 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3611 unsigned char *pkblob = s->p;
3615 do { /* do while (0) to make breaking easy */
3616 n = ssh1_read_bignum
3617 (s->p, s->responselen-(s->p-s->response),
3622 n = ssh1_read_bignum
3623 (s->p, s->responselen-(s->p-s->response),
3628 if (s->responselen - (s->p-s->response) < 4)
3630 s->commentlen = GET_32BIT(s->p);
3632 if (s->responselen - (s->p-s->response) <
3635 s->commentp = (char *)s->p;
3636 s->p += s->commentlen;
3640 logevent("Pageant key list packet was truncated");
3644 if (s->publickey_blob) {
3645 if (!memcmp(pkblob, s->publickey_blob,
3646 s->publickey_bloblen)) {
3647 logeventf(ssh, "Pageant key #%d matches "
3648 "configured key file", s->keyi);
3649 s->tried_publickey = 1;
3651 /* Skip non-configured key */
3654 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3655 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3656 PKT_BIGNUM, s->key.modulus, PKT_END);
3658 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3659 logevent("Key refused");
3662 logevent("Received RSA challenge");
3663 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3664 bombout(("Server's RSA challenge was badly formatted"));
3669 char *agentreq, *q, *ret;
3672 len = 1 + 4; /* message type, bit count */
3673 len += ssh1_bignum_length(s->key.exponent);
3674 len += ssh1_bignum_length(s->key.modulus);
3675 len += ssh1_bignum_length(s->challenge);
3676 len += 16; /* session id */
3677 len += 4; /* response format */
3678 agentreq = snewn(4 + len, char);
3679 PUT_32BIT(agentreq, len);
3681 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3682 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3684 q += ssh1_write_bignum(q, s->key.exponent);
3685 q += ssh1_write_bignum(q, s->key.modulus);
3686 q += ssh1_write_bignum(q, s->challenge);
3687 memcpy(q, s->session_id, 16);
3689 PUT_32BIT(q, 1); /* response format */
3690 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3691 ssh_agent_callback, ssh)) {
3696 bombout(("Unexpected data from server"
3697 " while waiting for agent"
3701 } while (pktin || inlen > 0);
3702 vret = ssh->agent_response;
3703 retlen = ssh->agent_response_len;
3708 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3709 logevent("Sending Pageant's response");
3710 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3711 PKT_DATA, ret + 5, 16,
3715 if (pktin->type == SSH1_SMSG_SUCCESS) {
3717 ("Pageant's response accepted");
3718 if (flags & FLAG_VERBOSE) {
3719 c_write_str(ssh, "Authenticated using"
3721 c_write(ssh, s->commentp,
3723 c_write_str(ssh, "\" from agent\r\n");
3728 ("Pageant's response not accepted");
3731 ("Pageant failed to answer challenge");
3735 logevent("No reply received from Pageant");
3738 freebn(s->key.exponent);
3739 freebn(s->key.modulus);
3740 freebn(s->challenge);
3745 if (s->publickey_blob && !s->tried_publickey)
3746 logevent("Configured key file not in Pageant");
3751 if (s->publickey_blob && !s->tried_publickey) {
3753 * Try public key authentication with the specified
3756 int got_passphrase; /* need not be kept over crReturn */
3757 if (flags & FLAG_VERBOSE)
3758 c_write_str(ssh, "Trying public key authentication.\r\n");
3759 logeventf(ssh, "Trying public key \"%s\"",
3760 filename_to_str(&ssh->cfg.keyfile));
3761 s->tried_publickey = 1;
3762 got_passphrase = FALSE;
3763 while (!got_passphrase) {
3765 * Get a passphrase, if necessary.
3767 char *passphrase = NULL; /* only written after crReturn */
3769 if (!s->publickey_encrypted) {
3770 if (flags & FLAG_VERBOSE)
3771 c_write_str(ssh, "No passphrase required.\r\n");
3774 int ret; /* need not be kept over crReturn */
3775 s->cur_prompt = new_prompts(ssh->frontend);
3776 s->cur_prompt->to_server = FALSE;
3777 s->cur_prompt->name = dupstr("SSH key passphrase");
3778 add_prompt(s->cur_prompt,
3779 dupprintf("Passphrase for key \"%.100s\": ",
3780 s->publickey_comment),
3781 FALSE, SSH_MAX_PASSWORD_LEN);
3782 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3785 crWaitUntil(!pktin);
3786 ret = get_userpass_input(s->cur_prompt, in, inlen);
3790 /* Failed to get a passphrase. Terminate. */
3791 free_prompts(s->cur_prompt);
3792 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3796 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3797 free_prompts(s->cur_prompt);
3800 * Try decrypting key with passphrase.
3802 ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
3805 memset(passphrase, 0, strlen(passphrase));
3809 /* Correct passphrase. */
3810 got_passphrase = TRUE;
3811 } else if (ret == 0) {
3812 c_write_str(ssh, "Couldn't load private key from ");
3813 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3814 c_write_str(ssh, " (");
3815 c_write_str(ssh, error);
3816 c_write_str(ssh, ").\r\n");
3817 got_passphrase = FALSE;
3818 break; /* go and try something else */
3819 } else if (ret == -1) {
3820 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3821 got_passphrase = FALSE;
3824 assert(0 && "unexpected return from loadrsakey()");
3825 got_passphrase = FALSE; /* placate optimisers */
3829 if (got_passphrase) {
3832 * Send a public key attempt.
3834 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3835 PKT_BIGNUM, s->key.modulus, PKT_END);
3838 if (pktin->type == SSH1_SMSG_FAILURE) {
3839 c_write_str(ssh, "Server refused our public key.\r\n");
3840 continue; /* go and try something else */
3842 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3843 bombout(("Bizarre response to offer of public key"));
3849 unsigned char buffer[32];
3850 Bignum challenge, response;
3852 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3853 bombout(("Server's RSA challenge was badly formatted"));
3856 response = rsadecrypt(challenge, &s->key);
3857 freebn(s->key.private_exponent);/* burn the evidence */
3859 for (i = 0; i < 32; i++) {
3860 buffer[i] = bignum_byte(response, 31 - i);
3864 MD5Update(&md5c, buffer, 32);
3865 MD5Update(&md5c, s->session_id, 16);
3866 MD5Final(buffer, &md5c);
3868 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3869 PKT_DATA, buffer, 16, PKT_END);
3876 if (pktin->type == SSH1_SMSG_FAILURE) {
3877 if (flags & FLAG_VERBOSE)
3878 c_write_str(ssh, "Failed to authenticate with"
3879 " our public key.\r\n");
3880 continue; /* go and try something else */
3881 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3882 bombout(("Bizarre response to RSA authentication response"));
3886 break; /* we're through! */
3892 * Otherwise, try various forms of password-like authentication.
3894 s->cur_prompt = new_prompts(ssh->frontend);
3896 if (ssh->cfg.try_tis_auth &&
3897 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3898 !s->tis_auth_refused) {
3899 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3900 logevent("Requested TIS authentication");
3901 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3903 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3904 logevent("TIS authentication declined");
3905 if (flags & FLAG_INTERACTIVE)
3906 c_write_str(ssh, "TIS authentication refused.\r\n");
3907 s->tis_auth_refused = 1;
3912 char *instr_suf, *prompt;
3914 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3916 bombout(("TIS challenge packet was badly formed"));
3919 logevent("Received TIS challenge");
3920 s->cur_prompt->to_server = TRUE;
3921 s->cur_prompt->name = dupstr("SSH TIS authentication");
3922 /* Prompt heuristic comes from OpenSSH */
3923 if (memchr(challenge, '\n', challengelen)) {
3924 instr_suf = dupstr("");
3925 prompt = dupprintf("%.*s", challengelen, challenge);
3927 instr_suf = dupprintf("%.*s", challengelen, challenge);
3928 prompt = dupstr("Response: ");
3930 s->cur_prompt->instruction =
3931 dupprintf("Using TIS authentication.%s%s",
3932 (*instr_suf) ? "\n" : "",
3934 s->cur_prompt->instr_reqd = TRUE;
3935 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3939 if (ssh->cfg.try_tis_auth &&
3940 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3941 !s->ccard_auth_refused) {
3942 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3943 logevent("Requested CryptoCard authentication");
3944 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3946 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3947 logevent("CryptoCard authentication declined");
3948 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3949 s->ccard_auth_refused = 1;
3954 char *instr_suf, *prompt;
3956 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3958 bombout(("CryptoCard challenge packet was badly formed"));
3961 logevent("Received CryptoCard challenge");
3962 s->cur_prompt->to_server = TRUE;
3963 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
3964 s->cur_prompt->name_reqd = FALSE;
3965 /* Prompt heuristic comes from OpenSSH */
3966 if (memchr(challenge, '\n', challengelen)) {
3967 instr_suf = dupstr("");
3968 prompt = dupprintf("%.*s", challengelen, challenge);
3970 instr_suf = dupprintf("%.*s", challengelen, challenge);
3971 prompt = dupstr("Response: ");
3973 s->cur_prompt->instruction =
3974 dupprintf("Using CryptoCard authentication.%s%s",
3975 (*instr_suf) ? "\n" : "",
3977 s->cur_prompt->instr_reqd = TRUE;
3978 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3982 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3983 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
3984 bombout(("No supported authentication methods available"));
3987 s->cur_prompt->to_server = TRUE;
3988 s->cur_prompt->name = dupstr("SSH password");
3989 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
3990 s->username, ssh->savedhost),
3991 FALSE, SSH_MAX_PASSWORD_LEN);
3995 * Show password prompt, having first obtained it via a TIS
3996 * or CryptoCard exchange if we're doing TIS or CryptoCard
4000 int ret; /* need not be kept over crReturn */
4001 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4004 crWaitUntil(!pktin);
4005 ret = get_userpass_input(s->cur_prompt, in, inlen);
4010 * Failed to get a password (for example
4011 * because one was supplied on the command line
4012 * which has already failed to work). Terminate.
4014 free_prompts(s->cur_prompt);
4015 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4020 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4022 * Defence against traffic analysis: we send a
4023 * whole bunch of packets containing strings of
4024 * different lengths. One of these strings is the
4025 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4026 * The others are all random data in
4027 * SSH1_MSG_IGNORE packets. This way a passive
4028 * listener can't tell which is the password, and
4029 * hence can't deduce the password length.
4031 * Anybody with a password length greater than 16
4032 * bytes is going to have enough entropy in their
4033 * password that a listener won't find it _that_
4034 * much help to know how long it is. So what we'll
4037 * - if password length < 16, we send 15 packets
4038 * containing string lengths 1 through 15
4040 * - otherwise, we let N be the nearest multiple
4041 * of 8 below the password length, and send 8
4042 * packets containing string lengths N through
4043 * N+7. This won't obscure the order of
4044 * magnitude of the password length, but it will
4045 * introduce a bit of extra uncertainty.
4047 * A few servers can't deal with SSH1_MSG_IGNORE, at
4048 * least in this context. For these servers, we need
4049 * an alternative defence. We make use of the fact
4050 * that the password is interpreted as a C string:
4051 * so we can append a NUL, then some random data.
4053 * A few servers can deal with neither SSH1_MSG_IGNORE
4054 * here _nor_ a padded password string.
4055 * For these servers we are left with no defences
4056 * against password length sniffing.
4058 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4059 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4061 * The server can deal with SSH1_MSG_IGNORE, so
4062 * we can use the primary defence.
4064 int bottom, top, pwlen, i;
4067 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4069 bottom = 0; /* zero length passwords are OK! :-) */
4072 bottom = pwlen & ~7;
4076 assert(pwlen >= bottom && pwlen <= top);
4078 randomstr = snewn(top + 1, char);
4080 for (i = bottom; i <= top; i++) {
4082 defer_packet(ssh, s->pwpkt_type,
4083 PKTT_PASSWORD, PKT_STR,
4084 s->cur_prompt->prompts[0]->result,
4085 PKTT_OTHER, PKT_END);
4087 for (j = 0; j < i; j++) {
4089 randomstr[j] = random_byte();
4090 } while (randomstr[j] == '\0');
4092 randomstr[i] = '\0';
4093 defer_packet(ssh, SSH1_MSG_IGNORE,
4094 PKT_STR, randomstr, PKT_END);
4097 logevent("Sending password with camouflage packets");
4098 ssh_pkt_defersend(ssh);
4101 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4103 * The server can't deal with SSH1_MSG_IGNORE
4104 * but can deal with padded passwords, so we
4105 * can use the secondary defence.
4111 len = strlen(s->cur_prompt->prompts[0]->result);
4112 if (len < sizeof(string)) {
4114 strcpy(string, s->cur_prompt->prompts[0]->result);
4115 len++; /* cover the zero byte */
4116 while (len < sizeof(string)) {
4117 string[len++] = (char) random_byte();
4120 ss = s->cur_prompt->prompts[0]->result;
4122 logevent("Sending length-padded password");
4123 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4124 PKT_INT, len, PKT_DATA, ss, len,
4125 PKTT_OTHER, PKT_END);
4128 * The server is believed unable to cope with
4129 * any of our password camouflage methods.
4132 len = strlen(s->cur_prompt->prompts[0]->result);
4133 logevent("Sending unpadded password");
4134 send_packet(ssh, s->pwpkt_type,
4135 PKTT_PASSWORD, PKT_INT, len,
4136 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4137 PKTT_OTHER, PKT_END);
4140 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4141 PKT_STR, s->cur_prompt->prompts[0]->result,
4142 PKTT_OTHER, PKT_END);
4144 logevent("Sent password");
4145 free_prompts(s->cur_prompt);
4147 if (pktin->type == SSH1_SMSG_FAILURE) {
4148 if (flags & FLAG_VERBOSE)
4149 c_write_str(ssh, "Access denied\r\n");
4150 logevent("Authentication refused");
4151 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4152 bombout(("Strange packet received, type %d", pktin->type));
4158 if (s->publickey_blob) {
4159 sfree(s->publickey_blob);
4160 sfree(s->publickey_comment);
4163 logevent("Authentication successful");
4168 void sshfwd_close(struct ssh_channel *c)
4172 if (ssh->state == SSH_STATE_CLOSED)
4177 * If halfopen is true, we have sent
4178 * CHANNEL_OPEN for this channel, but it hasn't even been
4179 * acknowledged by the server. So we must set a close flag
4180 * on it now, and then when the server acks the channel
4181 * open, we can close it then.
4184 if (ssh->version == 1) {
4185 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4187 c->closes = 1; /* sent MSG_CLOSE */
4189 int bytes_to_send = bufchain_size(&c->v.v2.outbuffer);
4190 if (bytes_to_send > 0) {
4192 * If we still have unsent data in our outgoing
4193 * buffer for this channel, we can't actually
4194 * initiate a close operation yet or that data
4195 * will be lost. Instead, set the pending_close
4196 * flag so that when we do clear the buffer
4197 * we'll start closing the channel.
4199 char logmsg[160] = {'\0'};
4202 "Forwarded port pending to be closed : "
4203 "%d bytes remaining",
4207 c->pending_close = TRUE;
4210 * No locally buffered data, so we can send the
4211 * close message immediately.
4213 struct Packet *pktout;
4214 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4215 ssh2_pkt_adduint32(pktout, c->remoteid);
4216 ssh2_pkt_send(ssh, pktout);
4217 c->closes = 1; /* sent MSG_CLOSE */
4218 logevent("Nothing left to send, closing channel");
4223 if (c->type == CHAN_X11) {
4225 logevent("Forwarded X11 connection terminated");
4226 } else if (c->type == CHAN_SOCKDATA ||
4227 c->type == CHAN_SOCKDATA_DORMANT) {
4229 logevent("Forwarded port closed");
4234 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4238 if (ssh->state == SSH_STATE_CLOSED)
4241 if (ssh->version == 1) {
4242 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4243 PKT_INT, c->remoteid,
4244 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
4245 PKTT_OTHER, PKT_END);
4247 * In SSH-1 we can return 0 here - implying that forwarded
4248 * connections are never individually throttled - because
4249 * the only circumstance that can cause throttling will be
4250 * the whole SSH connection backing up, in which case
4251 * _everything_ will be throttled as a whole.
4255 ssh2_add_channel_data(c, buf, len);
4256 return ssh2_try_send(c);
4260 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4265 if (ssh->state == SSH_STATE_CLOSED)
4268 if (ssh->version == 1) {
4269 buflimit = SSH1_BUFFER_LIMIT;
4271 buflimit = c->v.v2.locmaxwin;
4272 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4274 if (c->throttling_conn && bufsize <= buflimit) {
4275 c->throttling_conn = 0;
4276 ssh_throttle_conn(ssh, -1);
4280 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4282 struct queued_handler *qh = ssh->qhead;
4286 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4289 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4290 ssh->packet_dispatch[qh->msg1] = NULL;
4293 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4294 ssh->packet_dispatch[qh->msg2] = NULL;
4298 ssh->qhead = qh->next;
4300 if (ssh->qhead->msg1 > 0) {
4301 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4302 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4304 if (ssh->qhead->msg2 > 0) {
4305 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4306 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4309 ssh->qhead = ssh->qtail = NULL;
4310 ssh->packet_dispatch[pktin->type] = NULL;
4313 qh->handler(ssh, pktin, qh->ctx);
4318 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4319 chandler_fn_t handler, void *ctx)
4321 struct queued_handler *qh;
4323 qh = snew(struct queued_handler);
4326 qh->handler = handler;
4330 if (ssh->qtail == NULL) {
4334 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4335 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4338 assert(ssh->packet_dispatch[qh->msg2] == NULL);
4339 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4342 ssh->qtail->next = qh;
4347 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4349 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4351 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4352 SSH2_MSG_REQUEST_SUCCESS)) {
4353 logeventf(ssh, "Remote port forwarding from %s enabled",
4356 logeventf(ssh, "Remote port forwarding from %s refused",
4359 rpf = del234(ssh->rportfwds, pf);
4361 pf->pfrec->remote = NULL;
4366 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
4368 const char *portfwd_strptr = cfg->portfwd;
4369 struct ssh_portfwd *epf;
4372 if (!ssh->portfwds) {
4373 ssh->portfwds = newtree234(ssh_portcmp);
4376 * Go through the existing port forwardings and tag them
4377 * with status==DESTROY. Any that we want to keep will be
4378 * re-enabled (status==KEEP) as we go through the
4379 * configuration and find out which bits are the same as
4382 struct ssh_portfwd *epf;
4384 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4385 epf->status = DESTROY;
4388 while (*portfwd_strptr) {
4389 char address_family, type;
4390 int sport,dport,sserv,dserv;
4391 char sports[256], dports[256], saddr[256], host[256];
4394 address_family = 'A';
4396 if (*portfwd_strptr == 'A' ||
4397 *portfwd_strptr == '4' ||
4398 *portfwd_strptr == '6')
4399 address_family = *portfwd_strptr++;
4400 if (*portfwd_strptr == 'L' ||
4401 *portfwd_strptr == 'R' ||
4402 *portfwd_strptr == 'D')
4403 type = *portfwd_strptr++;
4408 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4409 if (*portfwd_strptr == ':') {
4411 * We've seen a colon in the middle of the
4412 * source port number. This means that
4413 * everything we've seen until now is the
4414 * source _address_, so we'll move it into
4415 * saddr and start sports from the beginning
4420 if (ssh->version == 1 && type == 'R') {
4421 logeventf(ssh, "SSH-1 cannot handle remote source address "
4422 "spec \"%s\"; ignoring", sports);
4424 strcpy(saddr, sports);
4427 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4431 if (*portfwd_strptr == '\t')
4434 while (*portfwd_strptr && *portfwd_strptr != ':') {
4435 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4438 if (*portfwd_strptr == ':')
4441 while (*portfwd_strptr) {
4442 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4446 dport = atoi(dports);
4450 dport = net_service_lookup(dports);
4452 logeventf(ssh, "Service lookup failed for destination"
4453 " port \"%s\"", dports);
4457 while (*portfwd_strptr) portfwd_strptr++;
4461 portfwd_strptr++; /* eat the NUL and move to next one */
4463 sport = atoi(sports);
4467 sport = net_service_lookup(sports);
4469 logeventf(ssh, "Service lookup failed for source"
4470 " port \"%s\"", sports);
4473 if (sport && dport) {
4474 /* Set up a description of the source port. */
4475 struct ssh_portfwd *pfrec, *epfrec;
4477 pfrec = snew(struct ssh_portfwd);
4479 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4480 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4481 pfrec->sport = sport;
4482 pfrec->daddr = *host ? dupstr(host) : NULL;
4483 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4484 pfrec->dport = dport;
4485 pfrec->local = NULL;
4486 pfrec->remote = NULL;
4487 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4488 address_family == '6' ? ADDRTYPE_IPV6 :
4491 epfrec = add234(ssh->portfwds, pfrec);
4492 if (epfrec != pfrec) {
4493 if (epfrec->status == DESTROY) {
4495 * We already have a port forwarding up and running
4496 * with precisely these parameters. Hence, no need
4497 * to do anything; simply re-tag the existing one
4500 epfrec->status = KEEP;
4503 * Anything else indicates that there was a duplicate
4504 * in our input, which we'll silently ignore.
4506 free_portfwd(pfrec);
4508 pfrec->status = CREATE;
4514 * Now go through and destroy any port forwardings which were
4517 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4518 if (epf->status == DESTROY) {
4521 message = dupprintf("%s port forwarding from %s%s%d",
4522 epf->type == 'L' ? "local" :
4523 epf->type == 'R' ? "remote" : "dynamic",
4524 epf->saddr ? epf->saddr : "",
4525 epf->saddr ? ":" : "",
4528 if (epf->type != 'D') {
4529 char *msg2 = dupprintf("%s to %s:%d", message,
4530 epf->daddr, epf->dport);
4535 logeventf(ssh, "Cancelling %s", message);
4538 /* epf->remote or epf->local may be NULL if setting up a
4539 * forwarding failed. */
4541 struct ssh_rportfwd *rpf = epf->remote;
4542 struct Packet *pktout;
4545 * Cancel the port forwarding at the server
4548 if (ssh->version == 1) {
4550 * We cannot cancel listening ports on the
4551 * server side in SSH-1! There's no message
4552 * to support it. Instead, we simply remove
4553 * the rportfwd record from the local end
4554 * so that any connections the server tries
4555 * to make on it are rejected.
4558 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4559 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4560 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4562 ssh2_pkt_addstring(pktout, epf->saddr);
4563 } else if (ssh->cfg.rport_acceptall) {
4564 /* XXX: ssh->cfg.rport_acceptall may not represent
4565 * what was used to open the original connection,
4566 * since it's reconfigurable. */
4567 ssh2_pkt_addstring(pktout, "0.0.0.0");
4569 ssh2_pkt_addstring(pktout, "127.0.0.1");
4571 ssh2_pkt_adduint32(pktout, epf->sport);
4572 ssh2_pkt_send(ssh, pktout);
4575 del234(ssh->rportfwds, rpf);
4577 } else if (epf->local) {
4578 pfd_terminate(epf->local);
4581 delpos234(ssh->portfwds, i);
4583 i--; /* so we don't skip one in the list */
4587 * And finally, set up any new port forwardings (status==CREATE).
4589 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4590 if (epf->status == CREATE) {
4591 char *sportdesc, *dportdesc;
4592 sportdesc = dupprintf("%s%s%s%s%d%s",
4593 epf->saddr ? epf->saddr : "",
4594 epf->saddr ? ":" : "",
4595 epf->sserv ? epf->sserv : "",
4596 epf->sserv ? "(" : "",
4598 epf->sserv ? ")" : "");
4599 if (epf->type == 'D') {
4602 dportdesc = dupprintf("%s:%s%s%d%s",
4604 epf->dserv ? epf->dserv : "",
4605 epf->dserv ? "(" : "",
4607 epf->dserv ? ")" : "");
4610 if (epf->type == 'L') {
4611 const char *err = pfd_addforward(epf->daddr, epf->dport,
4612 epf->saddr, epf->sport,
4615 epf->addressfamily);
4617 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4618 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4619 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4620 sportdesc, dportdesc,
4621 err ? " failed: " : "", err ? err : "");
4622 } else if (epf->type == 'D') {
4623 const char *err = pfd_addforward(NULL, -1,
4624 epf->saddr, epf->sport,
4627 epf->addressfamily);
4629 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4630 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4631 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4633 err ? " failed: " : "", err ? err : "");
4635 struct ssh_rportfwd *pf;
4638 * Ensure the remote port forwardings tree exists.
4640 if (!ssh->rportfwds) {
4641 if (ssh->version == 1)
4642 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4644 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4647 pf = snew(struct ssh_rportfwd);
4648 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4649 pf->dhost[lenof(pf->dhost)-1] = '\0';
4650 pf->dport = epf->dport;
4651 pf->sport = epf->sport;
4652 if (add234(ssh->rportfwds, pf) != pf) {
4653 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4654 epf->daddr, epf->dport);
4657 logeventf(ssh, "Requesting remote port %s"
4658 " forward to %s", sportdesc, dportdesc);
4660 pf->sportdesc = sportdesc;
4665 if (ssh->version == 1) {
4666 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4667 PKT_INT, epf->sport,
4668 PKT_STR, epf->daddr,
4669 PKT_INT, epf->dport,
4671 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4673 ssh_rportfwd_succfail, pf);
4675 struct Packet *pktout;
4676 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4677 ssh2_pkt_addstring(pktout, "tcpip-forward");
4678 ssh2_pkt_addbool(pktout, 1);/* want reply */
4680 ssh2_pkt_addstring(pktout, epf->saddr);
4681 } else if (cfg->rport_acceptall) {
4682 ssh2_pkt_addstring(pktout, "0.0.0.0");
4684 ssh2_pkt_addstring(pktout, "127.0.0.1");
4686 ssh2_pkt_adduint32(pktout, epf->sport);
4687 ssh2_pkt_send(ssh, pktout);
4689 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4690 SSH2_MSG_REQUEST_FAILURE,
4691 ssh_rportfwd_succfail, pf);
4700 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4703 int stringlen, bufsize;
4705 ssh_pkt_getstring(pktin, &string, &stringlen);
4706 if (string == NULL) {
4707 bombout(("Incoming terminal data packet was badly formed"));
4711 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4713 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4714 ssh->v1_stdout_throttling = 1;
4715 ssh_throttle_conn(ssh, +1);
4719 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4721 /* Remote side is trying to open a channel to talk to our
4722 * X-Server. Give them back a local channel number. */
4723 struct ssh_channel *c;
4724 int remoteid = ssh_pkt_getuint32(pktin);
4726 logevent("Received X11 connect request");
4727 /* Refuse if X11 forwarding is disabled. */
4728 if (!ssh->X11_fwd_enabled) {
4729 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4730 PKT_INT, remoteid, PKT_END);
4731 logevent("Rejected X11 connect request");
4733 c = snew(struct ssh_channel);
4736 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4737 NULL, -1, &ssh->cfg) != NULL) {
4738 logevent("Opening X11 forward connection failed");
4740 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4741 PKT_INT, remoteid, PKT_END);
4744 ("Opening X11 forward connection succeeded");
4745 c->remoteid = remoteid;
4746 c->halfopen = FALSE;
4747 c->localid = alloc_channel_id(ssh);
4749 c->pending_close = FALSE;
4750 c->throttling_conn = 0;
4751 c->type = CHAN_X11; /* identify channel type */
4752 add234(ssh->channels, c);
4753 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4754 PKT_INT, c->remoteid, PKT_INT,
4755 c->localid, PKT_END);
4756 logevent("Opened X11 forward channel");
4761 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4763 /* Remote side is trying to open a channel to talk to our
4764 * agent. Give them back a local channel number. */
4765 struct ssh_channel *c;
4766 int remoteid = ssh_pkt_getuint32(pktin);
4768 /* Refuse if agent forwarding is disabled. */
4769 if (!ssh->agentfwd_enabled) {
4770 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4771 PKT_INT, remoteid, PKT_END);
4773 c = snew(struct ssh_channel);
4775 c->remoteid = remoteid;
4776 c->halfopen = FALSE;
4777 c->localid = alloc_channel_id(ssh);
4779 c->pending_close = FALSE;
4780 c->throttling_conn = 0;
4781 c->type = CHAN_AGENT; /* identify channel type */
4782 c->u.a.lensofar = 0;
4783 add234(ssh->channels, c);
4784 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4785 PKT_INT, c->remoteid, PKT_INT, c->localid,
4790 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4792 /* Remote side is trying to open a channel to talk to a
4793 * forwarded port. Give them back a local channel number. */
4794 struct ssh_channel *c;
4795 struct ssh_rportfwd pf, *pfp;
4800 c = snew(struct ssh_channel);
4803 remoteid = ssh_pkt_getuint32(pktin);
4804 ssh_pkt_getstring(pktin, &host, &hostsize);
4805 port = ssh_pkt_getuint32(pktin);
4807 if (hostsize >= lenof(pf.dhost))
4808 hostsize = lenof(pf.dhost)-1;
4809 memcpy(pf.dhost, host, hostsize);
4810 pf.dhost[hostsize] = '\0';
4812 pfp = find234(ssh->rportfwds, &pf, NULL);
4815 logeventf(ssh, "Rejected remote port open request for %s:%d",
4817 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4818 PKT_INT, remoteid, PKT_END);
4820 logeventf(ssh, "Received remote port open request for %s:%d",
4822 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4823 c, &ssh->cfg, pfp->pfrec->addressfamily);
4825 logeventf(ssh, "Port open failed: %s", e);
4827 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4828 PKT_INT, remoteid, PKT_END);
4830 c->remoteid = remoteid;
4831 c->halfopen = FALSE;
4832 c->localid = alloc_channel_id(ssh);
4834 c->pending_close = FALSE;
4835 c->throttling_conn = 0;
4836 c->type = CHAN_SOCKDATA; /* identify channel type */
4837 add234(ssh->channels, c);
4838 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4839 PKT_INT, c->remoteid, PKT_INT,
4840 c->localid, PKT_END);
4841 logevent("Forwarded port opened successfully");
4846 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4848 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4849 unsigned int localid = ssh_pkt_getuint32(pktin);
4850 struct ssh_channel *c;
4852 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4853 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4854 c->remoteid = localid;
4855 c->halfopen = FALSE;
4856 c->type = CHAN_SOCKDATA;
4857 c->throttling_conn = 0;
4858 pfd_confirm(c->u.pfd.s);
4861 if (c && c->closes) {
4863 * We have a pending close on this channel,
4864 * which we decided on before the server acked
4865 * the channel open. So now we know the
4866 * remoteid, we can close it again.
4868 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4869 PKT_INT, c->remoteid, PKT_END);
4873 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4875 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4876 struct ssh_channel *c;
4878 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4879 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4880 logevent("Forwarded connection refused by server");
4881 pfd_close(c->u.pfd.s);
4882 del234(ssh->channels, c);
4887 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4889 /* Remote side closes a channel. */
4890 unsigned i = ssh_pkt_getuint32(pktin);
4891 struct ssh_channel *c;
4892 c = find234(ssh->channels, &i, ssh_channelfind);
4893 if (c && !c->halfopen) {
4896 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4898 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4899 logevent("Forwarded X11 connection terminated");
4900 assert(c->u.x11.s != NULL);
4901 x11_close(c->u.x11.s);
4904 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4905 logevent("Forwarded port closed");
4906 assert(c->u.pfd.s != NULL);
4907 pfd_close(c->u.pfd.s);
4911 c->closes |= (closetype << 2); /* seen this message */
4912 if (!(c->closes & closetype)) {
4913 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4915 c->closes |= closetype; /* sent it too */
4918 if (c->closes == 15) {
4919 del234(ssh->channels, c);
4923 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4924 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4925 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4930 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4932 /* Data sent down one of our channels. */
4933 int i = ssh_pkt_getuint32(pktin);
4936 struct ssh_channel *c;
4938 ssh_pkt_getstring(pktin, &p, &len);
4940 c = find234(ssh->channels, &i, ssh_channelfind);
4945 bufsize = x11_send(c->u.x11.s, p, len);
4948 bufsize = pfd_send(c->u.pfd.s, p, len);
4951 /* Data for an agent message. Buffer it. */
4953 if (c->u.a.lensofar < 4) {
4954 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
4955 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4959 c->u.a.lensofar += l;
4961 if (c->u.a.lensofar == 4) {
4963 4 + GET_32BIT(c->u.a.msglen);
4964 c->u.a.message = snewn(c->u.a.totallen,
4966 memcpy(c->u.a.message, c->u.a.msglen, 4);
4968 if (c->u.a.lensofar >= 4 && len > 0) {
4970 min(c->u.a.totallen - c->u.a.lensofar,
4972 memcpy(c->u.a.message + c->u.a.lensofar, p,
4976 c->u.a.lensofar += l;
4978 if (c->u.a.lensofar == c->u.a.totallen) {
4981 if (agent_query(c->u.a.message,
4984 ssh_agentf_callback, c))
4985 ssh_agentf_callback(c, reply, replylen);
4986 sfree(c->u.a.message);
4987 c->u.a.lensofar = 0;
4990 bufsize = 0; /* agent channels never back up */
4993 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
4994 c->throttling_conn = 1;
4995 ssh_throttle_conn(ssh, +1);
5000 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5002 ssh->exitcode = ssh_pkt_getuint32(pktin);
5003 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5004 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5006 * In case `helpful' firewalls or proxies tack
5007 * extra human-readable text on the end of the
5008 * session which we might mistake for another
5009 * encrypted packet, we close the session once
5010 * we've sent EXIT_CONFIRMATION.
5012 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5015 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5016 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5018 struct Packet *pktout = (struct Packet *)data;
5020 unsigned int arg = 0;
5021 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5022 if (i == lenof(ssh_ttymodes)) return;
5023 switch (ssh_ttymodes[i].type) {
5025 arg = ssh_tty_parse_specchar(val);
5028 arg = ssh_tty_parse_boolean(val);
5031 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5032 ssh2_pkt_addbyte(pktout, arg);
5036 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5037 struct Packet *pktin)
5039 crBegin(ssh->do_ssh1_connection_crstate);
5041 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5042 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5043 ssh1_smsg_stdout_stderr_data;
5045 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5046 ssh1_msg_channel_open_confirmation;
5047 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5048 ssh1_msg_channel_open_failure;
5049 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5050 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5051 ssh1_msg_channel_close;
5052 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5053 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5055 if (ssh->cfg.agentfwd && agent_exists()) {
5056 logevent("Requesting agent forwarding");
5057 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5061 if (pktin->type != SSH1_SMSG_SUCCESS
5062 && pktin->type != SSH1_SMSG_FAILURE) {
5063 bombout(("Protocol confusion"));
5065 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5066 logevent("Agent forwarding refused");
5068 logevent("Agent forwarding enabled");
5069 ssh->agentfwd_enabled = TRUE;
5070 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5074 if (ssh->cfg.x11_forward &&
5075 (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
5076 ssh->cfg.x11_auth, &ssh->cfg))) {
5077 logevent("Requesting X11 forwarding");
5079 * Note that while we blank the X authentication data here, we don't
5080 * take any special action to blank the start of an X11 channel,
5081 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5082 * without having session blanking enabled is likely to leak your
5083 * cookie into the log.
5085 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5086 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5087 PKT_STR, ssh->x11disp->remoteauthprotoname,
5089 PKT_STR, ssh->x11disp->remoteauthdatastring,
5091 PKT_INT, ssh->x11disp->screennum,
5094 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5095 PKT_STR, ssh->x11disp->remoteauthprotoname,
5097 PKT_STR, ssh->x11disp->remoteauthdatastring,
5104 if (pktin->type != SSH1_SMSG_SUCCESS
5105 && pktin->type != SSH1_SMSG_FAILURE) {
5106 bombout(("Protocol confusion"));
5108 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5109 logevent("X11 forwarding refused");
5111 logevent("X11 forwarding enabled");
5112 ssh->X11_fwd_enabled = TRUE;
5113 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5117 ssh_setup_portfwd(ssh, &ssh->cfg);
5118 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5120 if (!ssh->cfg.nopty) {
5122 /* Unpick the terminal-speed string. */
5123 /* XXX perhaps we should allow no speeds to be sent. */
5124 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5125 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
5126 /* Send the pty request. */
5127 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5128 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
5129 ssh_pkt_adduint32(pkt, ssh->term_height);
5130 ssh_pkt_adduint32(pkt, ssh->term_width);
5131 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5132 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5133 parse_ttymodes(ssh, ssh->cfg.ttymodes,
5134 ssh1_send_ttymode, (void *)pkt);
5135 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5136 ssh_pkt_adduint32(pkt, ssh->ispeed);
5137 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5138 ssh_pkt_adduint32(pkt, ssh->ospeed);
5139 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5141 ssh->state = SSH_STATE_INTERMED;
5145 if (pktin->type != SSH1_SMSG_SUCCESS
5146 && pktin->type != SSH1_SMSG_FAILURE) {
5147 bombout(("Protocol confusion"));
5149 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5150 c_write_str(ssh, "Server refused to allocate pty\r\n");
5151 ssh->editing = ssh->echoing = 1;
5153 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5154 ssh->ospeed, ssh->ispeed);
5156 ssh->editing = ssh->echoing = 1;
5159 if (ssh->cfg.compression) {
5160 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5164 if (pktin->type != SSH1_SMSG_SUCCESS
5165 && pktin->type != SSH1_SMSG_FAILURE) {
5166 bombout(("Protocol confusion"));
5168 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5169 c_write_str(ssh, "Server refused to compress\r\n");
5171 logevent("Started compression");
5172 ssh->v1_compressing = TRUE;
5173 ssh->cs_comp_ctx = zlib_compress_init();
5174 logevent("Initialised zlib (RFC1950) compression");
5175 ssh->sc_comp_ctx = zlib_decompress_init();
5176 logevent("Initialised zlib (RFC1950) decompression");
5180 * Start the shell or command.
5182 * Special case: if the first-choice command is an SSH-2
5183 * subsystem (hence not usable here) and the second choice
5184 * exists, we fall straight back to that.
5187 char *cmd = ssh->cfg.remote_cmd_ptr;
5189 if (!cmd) cmd = ssh->cfg.remote_cmd;
5191 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
5192 cmd = ssh->cfg.remote_cmd_ptr2;
5193 ssh->fallback_cmd = TRUE;
5196 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5198 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5199 logevent("Started session");
5202 ssh->state = SSH_STATE_SESSION;
5203 if (ssh->size_needed)
5204 ssh_size(ssh, ssh->term_width, ssh->term_height);
5205 if (ssh->eof_needed)
5206 ssh_special(ssh, TS_EOF);
5209 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5211 ssh->channels = newtree234(ssh_channelcmp);
5215 * By this point, most incoming packets are already being
5216 * handled by the dispatch table, and we need only pay
5217 * attention to the unusual ones.
5222 if (pktin->type == SSH1_SMSG_SUCCESS) {
5223 /* may be from EXEC_SHELL on some servers */
5224 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5225 /* may be from EXEC_SHELL on some servers
5226 * if no pty is available or in other odd cases. Ignore */
5228 bombout(("Strange packet received: type %d", pktin->type));
5233 int len = min(inlen, 512);
5234 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5235 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
5236 PKTT_OTHER, PKT_END);
5247 * Handle the top-level SSH-2 protocol.
5249 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5254 ssh_pkt_getstring(pktin, &msg, &msglen);
5255 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5258 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5260 /* log reason code in disconnect message */
5264 ssh_pkt_getstring(pktin, &msg, &msglen);
5265 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5268 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5270 /* Do nothing, because we're ignoring it! Duhh. */
5273 static void ssh1_protocol_setup(Ssh ssh)
5278 * Most messages are handled by the coroutines.
5280 for (i = 0; i < 256; i++)
5281 ssh->packet_dispatch[i] = NULL;
5284 * These special message types we install handlers for.
5286 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5287 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5288 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5291 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5292 struct Packet *pktin)
5294 unsigned char *in=(unsigned char*)vin;
5295 if (ssh->state == SSH_STATE_CLOSED)
5298 if (pktin && ssh->packet_dispatch[pktin->type]) {
5299 ssh->packet_dispatch[pktin->type](ssh, pktin);
5303 if (!ssh->protocol_initial_phase_done) {
5304 if (do_ssh1_login(ssh, in, inlen, pktin))
5305 ssh->protocol_initial_phase_done = TRUE;
5310 do_ssh1_connection(ssh, in, inlen, pktin);
5314 * Utility routine for decoding comma-separated strings in KEXINIT.
5316 static int in_commasep_string(char *needle, char *haystack, int haylen)
5319 if (!needle || !haystack) /* protect against null pointers */
5321 needlen = strlen(needle);
5324 * Is it at the start of the string?
5326 if (haylen >= needlen && /* haystack is long enough */
5327 !memcmp(needle, haystack, needlen) && /* initial match */
5328 (haylen == needlen || haystack[needlen] == ',')
5329 /* either , or EOS follows */
5333 * If not, search for the next comma and resume after that.
5334 * If no comma found, terminate.
5336 while (haylen > 0 && *haystack != ',')
5337 haylen--, haystack++;
5340 haylen--, haystack++; /* skip over comma itself */
5345 * Similar routine for checking whether we have the first string in a list.
5347 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5350 if (!needle || !haystack) /* protect against null pointers */
5352 needlen = strlen(needle);
5354 * Is it at the start of the string?
5356 if (haylen >= needlen && /* haystack is long enough */
5357 !memcmp(needle, haystack, needlen) && /* initial match */
5358 (haylen == needlen || haystack[needlen] == ',')
5359 /* either , or EOS follows */
5367 * SSH-2 key creation method.
5368 * (Currently assumes 2 lots of any hash are sufficient to generate
5369 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5371 #define SSH2_MKKEY_ITERS (2)
5372 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5373 unsigned char *keyspace)
5375 const struct ssh_hash *h = ssh->kex->hash;
5377 /* First hlen bytes. */
5379 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5380 hash_mpint(h, s, K);
5381 h->bytes(s, H, h->hlen);
5382 h->bytes(s, &chr, 1);
5383 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5384 h->final(s, keyspace);
5385 /* Next hlen bytes. */
5387 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5388 hash_mpint(h, s, K);
5389 h->bytes(s, H, h->hlen);
5390 h->bytes(s, keyspace, h->hlen);
5391 h->final(s, keyspace + h->hlen);
5395 * Handle the SSH-2 transport layer.
5397 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5398 struct Packet *pktin)
5400 unsigned char *in = (unsigned char *)vin;
5401 struct do_ssh2_transport_state {
5402 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5403 Bignum p, g, e, f, K;
5406 int kex_init_value, kex_reply_value;
5407 const struct ssh_mac **maclist;
5409 const struct ssh2_cipher *cscipher_tobe;
5410 const struct ssh2_cipher *sccipher_tobe;
5411 const struct ssh_mac *csmac_tobe;
5412 const struct ssh_mac *scmac_tobe;
5413 const struct ssh_compress *cscomp_tobe;
5414 const struct ssh_compress *sccomp_tobe;
5415 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5416 int hostkeylen, siglen, rsakeylen;
5417 void *hkey; /* actual host key */
5418 void *rsakey; /* for RSA kex */
5419 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5420 int n_preferred_kex;
5421 const struct ssh_kexes *preferred_kex[KEX_MAX];
5422 int n_preferred_ciphers;
5423 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5424 const struct ssh_compress *preferred_comp;
5425 int got_session_id, activated_authconn;
5426 struct Packet *pktout;
5431 crState(do_ssh2_transport_state);
5433 crBegin(ssh->do_ssh2_transport_crstate);
5435 s->cscipher_tobe = s->sccipher_tobe = NULL;
5436 s->csmac_tobe = s->scmac_tobe = NULL;
5437 s->cscomp_tobe = s->sccomp_tobe = NULL;
5439 s->got_session_id = s->activated_authconn = FALSE;
5442 * Be prepared to work around the buggy MAC problem.
5444 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5445 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5447 s->maclist = macs, s->nmacs = lenof(macs);
5450 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5452 int i, j, commalist_started;
5455 * Set up the preferred key exchange. (NULL => warn below here)
5457 s->n_preferred_kex = 0;
5458 for (i = 0; i < KEX_MAX; i++) {
5459 switch (ssh->cfg.ssh_kexlist[i]) {
5461 s->preferred_kex[s->n_preferred_kex++] =
5462 &ssh_diffiehellman_gex;
5465 s->preferred_kex[s->n_preferred_kex++] =
5466 &ssh_diffiehellman_group14;
5469 s->preferred_kex[s->n_preferred_kex++] =
5470 &ssh_diffiehellman_group1;
5473 s->preferred_kex[s->n_preferred_kex++] =
5477 /* Flag for later. Don't bother if it's the last in
5479 if (i < KEX_MAX - 1) {
5480 s->preferred_kex[s->n_preferred_kex++] = NULL;
5487 * Set up the preferred ciphers. (NULL => warn below here)
5489 s->n_preferred_ciphers = 0;
5490 for (i = 0; i < CIPHER_MAX; i++) {
5491 switch (ssh->cfg.ssh_cipherlist[i]) {
5492 case CIPHER_BLOWFISH:
5493 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5496 if (ssh->cfg.ssh2_des_cbc) {
5497 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5501 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5504 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5506 case CIPHER_ARCFOUR:
5507 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5510 /* Flag for later. Don't bother if it's the last in
5512 if (i < CIPHER_MAX - 1) {
5513 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5520 * Set up preferred compression.
5522 if (ssh->cfg.compression)
5523 s->preferred_comp = &ssh_zlib;
5525 s->preferred_comp = &ssh_comp_none;
5528 * Enable queueing of outgoing auth- or connection-layer
5529 * packets while we are in the middle of a key exchange.
5531 ssh->queueing = TRUE;
5534 * Flag that KEX is in progress.
5536 ssh->kex_in_progress = TRUE;
5539 * Construct and send our key exchange packet.
5541 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5542 for (i = 0; i < 16; i++)
5543 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5544 /* List key exchange algorithms. */
5545 ssh2_pkt_addstring_start(s->pktout);
5546 commalist_started = 0;
5547 for (i = 0; i < s->n_preferred_kex; i++) {
5548 const struct ssh_kexes *k = s->preferred_kex[i];
5549 if (!k) continue; /* warning flag */
5550 for (j = 0; j < k->nkexes; j++) {
5551 if (commalist_started)
5552 ssh2_pkt_addstring_str(s->pktout, ",");
5553 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5554 commalist_started = 1;
5557 /* List server host key algorithms. */
5558 ssh2_pkt_addstring_start(s->pktout);
5559 for (i = 0; i < lenof(hostkey_algs); i++) {
5560 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5561 if (i < lenof(hostkey_algs) - 1)
5562 ssh2_pkt_addstring_str(s->pktout, ",");
5564 /* List client->server encryption algorithms. */
5565 ssh2_pkt_addstring_start(s->pktout);
5566 commalist_started = 0;
5567 for (i = 0; i < s->n_preferred_ciphers; i++) {
5568 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5569 if (!c) continue; /* warning flag */
5570 for (j = 0; j < c->nciphers; j++) {
5571 if (commalist_started)
5572 ssh2_pkt_addstring_str(s->pktout, ",");
5573 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5574 commalist_started = 1;
5577 /* List server->client encryption algorithms. */
5578 ssh2_pkt_addstring_start(s->pktout);
5579 commalist_started = 0;
5580 for (i = 0; i < s->n_preferred_ciphers; i++) {
5581 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5582 if (!c) continue; /* warning flag */
5583 for (j = 0; j < c->nciphers; j++) {
5584 if (commalist_started)
5585 ssh2_pkt_addstring_str(s->pktout, ",");
5586 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5587 commalist_started = 1;
5590 /* List client->server MAC algorithms. */
5591 ssh2_pkt_addstring_start(s->pktout);
5592 for (i = 0; i < s->nmacs; i++) {
5593 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5594 if (i < s->nmacs - 1)
5595 ssh2_pkt_addstring_str(s->pktout, ",");
5597 /* List server->client MAC algorithms. */
5598 ssh2_pkt_addstring_start(s->pktout);
5599 for (i = 0; i < s->nmacs; i++) {
5600 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5601 if (i < s->nmacs - 1)
5602 ssh2_pkt_addstring_str(s->pktout, ",");
5604 /* List client->server compression algorithms. */
5605 ssh2_pkt_addstring_start(s->pktout);
5606 assert(lenof(compressions) > 1);
5607 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5608 for (i = 0; i < lenof(compressions); i++) {
5609 const struct ssh_compress *c = compressions[i];
5610 if (c != s->preferred_comp) {
5611 ssh2_pkt_addstring_str(s->pktout, ",");
5612 ssh2_pkt_addstring_str(s->pktout, c->name);
5615 /* List server->client compression algorithms. */
5616 ssh2_pkt_addstring_start(s->pktout);
5617 assert(lenof(compressions) > 1);
5618 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5619 for (i = 0; i < lenof(compressions); i++) {
5620 const struct ssh_compress *c = compressions[i];
5621 if (c != s->preferred_comp) {
5622 ssh2_pkt_addstring_str(s->pktout, ",");
5623 ssh2_pkt_addstring_str(s->pktout, c->name);
5626 /* List client->server languages. Empty list. */
5627 ssh2_pkt_addstring_start(s->pktout);
5628 /* List server->client languages. Empty list. */
5629 ssh2_pkt_addstring_start(s->pktout);
5630 /* First KEX packet does _not_ follow, because we're not that brave. */
5631 ssh2_pkt_addbool(s->pktout, FALSE);
5633 ssh2_pkt_adduint32(s->pktout, 0);
5636 s->our_kexinitlen = s->pktout->length - 5;
5637 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5638 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5640 ssh2_pkt_send_noqueue(ssh, s->pktout);
5646 * Now examine the other side's KEXINIT to see what we're up
5650 char *str, *preferred;
5653 if (pktin->type != SSH2_MSG_KEXINIT) {
5654 bombout(("expected key exchange packet from server"));
5658 ssh->hostkey = NULL;
5659 s->cscipher_tobe = NULL;
5660 s->sccipher_tobe = NULL;
5661 s->csmac_tobe = NULL;
5662 s->scmac_tobe = NULL;
5663 s->cscomp_tobe = NULL;
5664 s->sccomp_tobe = NULL;
5665 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5667 pktin->savedpos += 16; /* skip garbage cookie */
5668 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5671 for (i = 0; i < s->n_preferred_kex; i++) {
5672 const struct ssh_kexes *k = s->preferred_kex[i];
5676 for (j = 0; j < k->nkexes; j++) {
5677 if (!preferred) preferred = k->list[j]->name;
5678 if (in_commasep_string(k->list[j]->name, str, len)) {
5679 ssh->kex = k->list[j];
5688 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5689 str ? str : "(null)"));
5693 * Note that the server's guess is considered wrong if it doesn't match
5694 * the first algorithm in our list, even if it's still the algorithm
5697 s->guessok = first_in_commasep_string(preferred, str, len);
5698 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5699 for (i = 0; i < lenof(hostkey_algs); i++) {
5700 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5701 ssh->hostkey = hostkey_algs[i];
5705 s->guessok = s->guessok &&
5706 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5707 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5708 for (i = 0; i < s->n_preferred_ciphers; i++) {
5709 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5711 s->warn_cscipher = TRUE;
5713 for (j = 0; j < c->nciphers; j++) {
5714 if (in_commasep_string(c->list[j]->name, str, len)) {
5715 s->cscipher_tobe = c->list[j];
5720 if (s->cscipher_tobe)
5723 if (!s->cscipher_tobe) {
5724 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5725 str ? str : "(null)"));
5729 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5730 for (i = 0; i < s->n_preferred_ciphers; i++) {
5731 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5733 s->warn_sccipher = TRUE;
5735 for (j = 0; j < c->nciphers; j++) {
5736 if (in_commasep_string(c->list[j]->name, str, len)) {
5737 s->sccipher_tobe = c->list[j];
5742 if (s->sccipher_tobe)
5745 if (!s->sccipher_tobe) {
5746 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5747 str ? str : "(null)"));
5751 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5752 for (i = 0; i < s->nmacs; i++) {
5753 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5754 s->csmac_tobe = s->maclist[i];
5758 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5759 for (i = 0; i < s->nmacs; i++) {
5760 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5761 s->scmac_tobe = s->maclist[i];
5765 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5766 for (i = 0; i < lenof(compressions) + 1; i++) {
5767 const struct ssh_compress *c =
5768 i == 0 ? s->preferred_comp : compressions[i - 1];
5769 if (in_commasep_string(c->name, str, len)) {
5774 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5775 for (i = 0; i < lenof(compressions) + 1; i++) {
5776 const struct ssh_compress *c =
5777 i == 0 ? s->preferred_comp : compressions[i - 1];
5778 if (in_commasep_string(c->name, str, len)) {
5783 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5784 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5785 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5788 ssh_set_frozen(ssh, 1);
5789 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5791 ssh_dialog_callback, ssh);
5792 if (s->dlgret < 0) {
5796 bombout(("Unexpected data from server while"
5797 " waiting for user response"));
5800 } while (pktin || inlen > 0);
5801 s->dlgret = ssh->user_response;
5803 ssh_set_frozen(ssh, 0);
5804 if (s->dlgret == 0) {
5805 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5811 if (s->warn_cscipher) {
5812 ssh_set_frozen(ssh, 1);
5813 s->dlgret = askalg(ssh->frontend,
5814 "client-to-server cipher",
5815 s->cscipher_tobe->name,
5816 ssh_dialog_callback, ssh);
5817 if (s->dlgret < 0) {
5821 bombout(("Unexpected data from server while"
5822 " waiting for user response"));
5825 } while (pktin || inlen > 0);
5826 s->dlgret = ssh->user_response;
5828 ssh_set_frozen(ssh, 0);
5829 if (s->dlgret == 0) {
5830 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5836 if (s->warn_sccipher) {
5837 ssh_set_frozen(ssh, 1);
5838 s->dlgret = askalg(ssh->frontend,
5839 "server-to-client cipher",
5840 s->sccipher_tobe->name,
5841 ssh_dialog_callback, ssh);
5842 if (s->dlgret < 0) {
5846 bombout(("Unexpected data from server while"
5847 " waiting for user response"));
5850 } while (pktin || inlen > 0);
5851 s->dlgret = ssh->user_response;
5853 ssh_set_frozen(ssh, 0);
5854 if (s->dlgret == 0) {
5855 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5861 ssh->exhash = ssh->kex->hash->init();
5862 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5863 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5864 hash_string(ssh->kex->hash, ssh->exhash,
5865 s->our_kexinit, s->our_kexinitlen);
5866 sfree(s->our_kexinit);
5867 if (pktin->length > 5)
5868 hash_string(ssh->kex->hash, ssh->exhash,
5869 pktin->data + 5, pktin->length - 5);
5871 if (s->ignorepkt) /* first_kex_packet_follows */
5872 crWaitUntil(pktin); /* Ignore packet */
5875 if (ssh->kex->main_type == KEXTYPE_DH) {
5877 * Work out the number of bits of key we will need from the
5878 * key exchange. We start with the maximum key length of
5884 csbits = s->cscipher_tobe->keylen;
5885 scbits = s->sccipher_tobe->keylen;
5886 s->nbits = (csbits > scbits ? csbits : scbits);
5888 /* The keys only have hlen-bit entropy, since they're based on
5889 * a hash. So cap the key size at hlen bits. */
5890 if (s->nbits > ssh->kex->hash->hlen * 8)
5891 s->nbits = ssh->kex->hash->hlen * 8;
5894 * If we're doing Diffie-Hellman group exchange, start by
5895 * requesting a group.
5897 if (!ssh->kex->pdata) {
5898 logevent("Doing Diffie-Hellman group exchange");
5899 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
5901 * Work out how big a DH group we will need to allow that
5904 s->pbits = 512 << ((s->nbits - 1) / 64);
5905 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5906 ssh2_pkt_adduint32(s->pktout, s->pbits);
5907 ssh2_pkt_send_noqueue(ssh, s->pktout);
5910 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5911 bombout(("expected key exchange group packet from server"));
5914 s->p = ssh2_pkt_getmp(pktin);
5915 s->g = ssh2_pkt_getmp(pktin);
5916 if (!s->p || !s->g) {
5917 bombout(("unable to read mp-ints from incoming group packet"));
5920 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5921 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5922 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5924 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
5925 ssh->kex_ctx = dh_setup_group(ssh->kex);
5926 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5927 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5928 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5929 ssh->kex->groupname);
5932 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
5933 ssh->kex->hash->text_name);
5935 * Now generate and send e for Diffie-Hellman.
5937 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5938 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5939 s->pktout = ssh2_pkt_init(s->kex_init_value);
5940 ssh2_pkt_addmp(s->pktout, s->e);
5941 ssh2_pkt_send_noqueue(ssh, s->pktout);
5943 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5945 if (pktin->type != s->kex_reply_value) {
5946 bombout(("expected key exchange reply packet from server"));
5949 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5950 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5951 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5952 s->f = ssh2_pkt_getmp(pktin);
5954 bombout(("unable to parse key exchange reply packet"));
5957 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5959 s->K = dh_find_K(ssh->kex_ctx, s->f);
5961 /* We assume everything from now on will be quick, and it might
5962 * involve user interaction. */
5963 set_busy_status(ssh->frontend, BUSY_NOT);
5965 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5966 if (!ssh->kex->pdata) {
5967 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5968 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5969 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5971 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5972 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5974 dh_cleanup(ssh->kex_ctx);
5976 if (!ssh->kex->pdata) {
5981 logeventf(ssh, "Doing RSA key exchange with hash %s",
5982 ssh->kex->hash->text_name);
5983 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
5985 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
5989 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
5990 bombout(("expected RSA public key packet from server"));
5994 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5995 hash_string(ssh->kex->hash, ssh->exhash,
5996 s->hostkeydata, s->hostkeylen);
5997 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6001 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6002 s->rsakeydata = snewn(s->rsakeylen, char);
6003 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6006 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6008 sfree(s->rsakeydata);
6009 bombout(("unable to parse RSA public key from server"));
6013 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6016 * Next, set up a shared secret K, of precisely KLEN -
6017 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6018 * RSA key modulus and HLEN is the bit length of the hash
6022 int klen = ssh_rsakex_klen(s->rsakey);
6023 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6025 unsigned char *kstr1, *kstr2, *outstr;
6026 int kstr1len, kstr2len, outstrlen;
6028 s->K = bn_power_2(nbits - 1);
6030 for (i = 0; i < nbits; i++) {
6032 byte = random_byte();
6034 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6038 * Encode this as an mpint.
6040 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6041 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6042 PUT_32BIT(kstr2, kstr1len);
6043 memcpy(kstr2 + 4, kstr1, kstr1len);
6046 * Encrypt it with the given RSA key.
6048 outstrlen = (klen + 7) / 8;
6049 outstr = snewn(outstrlen, unsigned char);
6050 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6051 outstr, outstrlen, s->rsakey);
6054 * And send it off in a return packet.
6056 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6057 ssh2_pkt_addstring_start(s->pktout);
6058 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6059 ssh2_pkt_send_noqueue(ssh, s->pktout);
6061 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6068 ssh_rsakex_freekey(s->rsakey);
6071 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6072 sfree(s->rsakeydata);
6073 bombout(("expected signature packet from server"));
6077 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6079 sfree(s->rsakeydata);
6082 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6083 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6084 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6086 ssh->kex_ctx = NULL;
6089 debug(("Exchange hash is:\n"));
6090 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6094 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6095 (char *)s->exchange_hash,
6096 ssh->kex->hash->hlen)) {
6097 bombout(("Server's host key did not match the signature supplied"));
6102 * Authenticate remote host: verify host key. (We've already
6103 * checked the signature of the exchange hash.)
6105 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6106 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6107 ssh_set_frozen(ssh, 1);
6108 s->dlgret = verify_ssh_host_key(ssh->frontend,
6109 ssh->savedhost, ssh->savedport,
6110 ssh->hostkey->keytype, s->keystr,
6112 ssh_dialog_callback, ssh);
6113 if (s->dlgret < 0) {
6117 bombout(("Unexpected data from server while waiting"
6118 " for user host key response"));
6121 } while (pktin || inlen > 0);
6122 s->dlgret = ssh->user_response;
6124 ssh_set_frozen(ssh, 0);
6125 if (s->dlgret == 0) {
6126 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6130 if (!s->got_session_id) { /* don't bother logging this in rekeys */
6131 logevent("Host key fingerprint is:");
6132 logevent(s->fingerprint);
6134 sfree(s->fingerprint);
6136 ssh->hostkey->freekey(s->hkey);
6139 * The exchange hash from the very first key exchange is also
6140 * the session id, used in session key construction and
6143 if (!s->got_session_id) {
6144 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6145 memcpy(ssh->v2_session_id, s->exchange_hash,
6146 sizeof(s->exchange_hash));
6147 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6148 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6149 s->got_session_id = TRUE;
6153 * Send SSH2_MSG_NEWKEYS.
6155 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6156 ssh2_pkt_send_noqueue(ssh, s->pktout);
6157 ssh->outgoing_data_size = 0; /* start counting from here */
6160 * We've sent client NEWKEYS, so create and initialise
6161 * client-to-server session keys.
6163 if (ssh->cs_cipher_ctx)
6164 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6165 ssh->cscipher = s->cscipher_tobe;
6166 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6168 if (ssh->cs_mac_ctx)
6169 ssh->csmac->free_context(ssh->cs_mac_ctx);
6170 ssh->csmac = s->csmac_tobe;
6171 ssh->cs_mac_ctx = ssh->csmac->make_context();
6173 if (ssh->cs_comp_ctx)
6174 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6175 ssh->cscomp = s->cscomp_tobe;
6176 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6179 * Set IVs on client-to-server keys. Here we use the exchange
6180 * hash from the _first_ key exchange.
6183 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6184 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6185 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6186 assert((ssh->cscipher->keylen+7) / 8 <=
6187 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6188 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6189 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6190 assert(ssh->cscipher->blksize <=
6191 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6192 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6193 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6194 assert(ssh->csmac->len <=
6195 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6196 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6197 memset(keyspace, 0, sizeof(keyspace));
6200 logeventf(ssh, "Initialised %.200s client->server encryption",
6201 ssh->cscipher->text_name);
6202 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6203 ssh->csmac->text_name);
6204 if (ssh->cscomp->text_name)
6205 logeventf(ssh, "Initialised %s compression",
6206 ssh->cscomp->text_name);
6209 * Now our end of the key exchange is complete, we can send all
6210 * our queued higher-layer packets.
6212 ssh->queueing = FALSE;
6213 ssh2_pkt_queuesend(ssh);
6216 * Expect SSH2_MSG_NEWKEYS from server.
6219 if (pktin->type != SSH2_MSG_NEWKEYS) {
6220 bombout(("expected new-keys packet from server"));
6223 ssh->incoming_data_size = 0; /* start counting from here */
6226 * We've seen server NEWKEYS, so create and initialise
6227 * server-to-client session keys.
6229 if (ssh->sc_cipher_ctx)
6230 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6231 ssh->sccipher = s->sccipher_tobe;
6232 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6234 if (ssh->sc_mac_ctx)
6235 ssh->scmac->free_context(ssh->sc_mac_ctx);
6236 ssh->scmac = s->scmac_tobe;
6237 ssh->sc_mac_ctx = ssh->scmac->make_context();
6239 if (ssh->sc_comp_ctx)
6240 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6241 ssh->sccomp = s->sccomp_tobe;
6242 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6245 * Set IVs on server-to-client keys. Here we use the exchange
6246 * hash from the _first_ key exchange.
6249 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6250 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6251 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6252 assert((ssh->sccipher->keylen+7) / 8 <=
6253 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6254 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6255 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6256 assert(ssh->sccipher->blksize <=
6257 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6258 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6259 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6260 assert(ssh->scmac->len <=
6261 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6262 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6263 memset(keyspace, 0, sizeof(keyspace));
6265 logeventf(ssh, "Initialised %.200s server->client encryption",
6266 ssh->sccipher->text_name);
6267 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6268 ssh->scmac->text_name);
6269 if (ssh->sccomp->text_name)
6270 logeventf(ssh, "Initialised %s decompression",
6271 ssh->sccomp->text_name);
6274 * Free shared secret.
6279 * Key exchange is over. Loop straight back round if we have a
6280 * deferred rekey reason.
6282 if (ssh->deferred_rekey_reason) {
6283 logevent(ssh->deferred_rekey_reason);
6285 ssh->deferred_rekey_reason = NULL;
6286 goto begin_key_exchange;
6290 * Otherwise, schedule a timer for our next rekey.
6292 ssh->kex_in_progress = FALSE;
6293 ssh->last_rekey = GETTICKCOUNT();
6294 if (ssh->cfg.ssh_rekey_time != 0)
6295 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6299 * If this is the first key exchange phase, we must pass the
6300 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6301 * wants to see it but because it will need time to initialise
6302 * itself before it sees an actual packet. In subsequent key
6303 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6304 * it would only confuse the layer above.
6306 if (s->activated_authconn) {
6309 s->activated_authconn = TRUE;
6312 * Now we're encrypting. Begin returning 1 to the protocol main
6313 * function so that other things can run on top of the
6314 * transport. If we ever see a KEXINIT, we must go back to the
6317 * We _also_ go back to the start if we see pktin==NULL and
6318 * inlen==-1, because this is a special signal meaning
6319 * `initiate client-driven rekey', and `in' contains a message
6320 * giving the reason for the rekey.
6322 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6323 (!pktin && inlen == -1))) {
6328 logevent("Server initiated key re-exchange");
6331 * Special case: if the server bug is set that doesn't
6332 * allow rekeying, we give a different log message and
6333 * continue waiting. (If such a server _initiates_ a rekey,
6334 * we process it anyway!)
6336 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6337 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6339 /* Reset the counters, so that at least this message doesn't
6340 * hit the event log _too_ often. */
6341 ssh->outgoing_data_size = 0;
6342 ssh->incoming_data_size = 0;
6343 if (ssh->cfg.ssh_rekey_time != 0) {
6345 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6348 goto wait_for_rekey; /* this is utterly horrid */
6350 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6353 goto begin_key_exchange;
6359 * Add data to an SSH-2 channel output buffer.
6361 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6364 bufchain_add(&c->v.v2.outbuffer, buf, len);
6368 * Attempt to send data on an SSH-2 channel.
6370 static int ssh2_try_send(struct ssh_channel *c)
6373 struct Packet *pktout;
6375 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6378 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6379 if ((unsigned)len > c->v.v2.remwindow)
6380 len = c->v.v2.remwindow;
6381 if ((unsigned)len > c->v.v2.remmaxpkt)
6382 len = c->v.v2.remmaxpkt;
6383 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6384 ssh2_pkt_adduint32(pktout, c->remoteid);
6385 ssh2_pkt_addstring_start(pktout);
6386 dont_log_data(ssh, pktout, PKTLOG_OMIT);
6387 ssh2_pkt_addstring_data(pktout, data, len);
6388 end_log_omission(ssh, pktout);
6389 ssh2_pkt_send(ssh, pktout);
6390 bufchain_consume(&c->v.v2.outbuffer, len);
6391 c->v.v2.remwindow -= len;
6395 * After having sent as much data as we can, return the amount
6398 return bufchain_size(&c->v.v2.outbuffer);
6401 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
6405 return; /* don't send on closing channels */
6406 bufsize = ssh2_try_send(c);
6409 case CHAN_MAINSESSION:
6410 /* stdin need not receive an unthrottle
6411 * notification since it will be polled */
6414 x11_unthrottle(c->u.x11.s);
6417 /* agent sockets are request/response and need no
6418 * buffer management */
6421 pfd_unthrottle(c->u.pfd.s);
6427 * If we've emptied the channel's output buffer and there's a
6428 * pending close event, start the channel-closing procedure.
6430 if (c->pending_close && bufchain_size(&c->v.v2.outbuffer) == 0) {
6431 struct Packet *pktout;
6432 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6433 ssh2_pkt_adduint32(pktout, c->remoteid);
6434 ssh2_pkt_send(ssh, pktout);
6436 c->pending_close = FALSE;
6441 * Set up most of a new ssh_channel for SSH-2.
6443 static void ssh2_channel_init(struct ssh_channel *c)
6446 c->localid = alloc_channel_id(ssh);
6448 c->pending_close = FALSE;
6449 c->throttling_conn = FALSE;
6450 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
6451 ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
6452 c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL;
6453 c->v.v2.throttle_state = UNTHROTTLED;
6454 bufchain_init(&c->v.v2.outbuffer);
6458 * Potentially enlarge the window on an SSH-2 channel.
6460 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6465 * Never send WINDOW_ADJUST for a channel that the remote side
6466 * already thinks it's closed; there's no point, since it won't
6467 * be sending any more data anyway.
6473 * If the remote end has a habit of ignoring maxpkt, limit the
6474 * window so that it has no choice (assuming it doesn't ignore the
6477 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6478 newwin = OUR_V2_MAXPKT;
6482 * Only send a WINDOW_ADJUST if there's significantly more window
6483 * available than the other end thinks there is. This saves us
6484 * sending a WINDOW_ADJUST for every character in a shell session.
6486 * "Significant" is arbitrarily defined as half the window size.
6488 if (newwin / 2 >= c->v.v2.locwindow) {
6489 struct Packet *pktout;
6493 * In order to keep track of how much window the client
6494 * actually has available, we'd like it to acknowledge each
6495 * WINDOW_ADJUST. We can't do that directly, so we accompany
6496 * it with a CHANNEL_REQUEST that has to be acknowledged.
6498 * This is only necessary if we're opening the window wide.
6499 * If we're not, then throughput is being constrained by
6500 * something other than the maximum window size anyway.
6502 * We also only send this if the main channel has finished its
6503 * initial CHANNEL_REQUESTs and installed the default
6504 * CHANNEL_FAILURE handler, so as not to risk giving it
6505 * unexpected CHANNEL_FAILUREs.
6507 if (newwin == c->v.v2.locmaxwin &&
6508 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) {
6509 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6510 ssh2_pkt_adduint32(pktout, c->remoteid);
6511 ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");
6512 ssh2_pkt_addbool(pktout, TRUE);
6513 ssh2_pkt_send(ssh, pktout);
6516 * CHANNEL_FAILURE doesn't come with any indication of
6517 * what message caused it, so we have to keep track of the
6518 * outstanding CHANNEL_REQUESTs ourselves.
6520 wa = snew(struct winadj);
6521 wa->size = newwin - c->v.v2.locwindow;
6523 if (!c->v.v2.winadj_head)
6524 c->v.v2.winadj_head = wa;
6526 c->v.v2.winadj_tail->next = wa;
6527 c->v.v2.winadj_tail = wa;
6528 if (c->v.v2.throttle_state != UNTHROTTLED)
6529 c->v.v2.throttle_state = UNTHROTTLING;
6531 /* Pretend the WINDOW_ADJUST was acked immediately. */
6532 c->v.v2.remlocwin = newwin;
6533 c->v.v2.throttle_state = THROTTLED;
6535 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6536 ssh2_pkt_adduint32(pktout, c->remoteid);
6537 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6538 ssh2_pkt_send(ssh, pktout);
6539 c->v.v2.locwindow = newwin;
6544 * Find the channel associated with a message. If there's no channel,
6545 * or it's not properly open, make a noise about it and return NULL.
6547 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6549 unsigned localid = ssh_pkt_getuint32(pktin);
6550 struct ssh_channel *c;
6552 c = find234(ssh->channels, &localid, ssh_channelfind);
6554 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6555 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6556 char *buf = dupprintf("Received %s for %s channel %u",
6557 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6559 c ? "half-open" : "nonexistent", localid);
6560 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6567 static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin)
6570 * This should never get called. All channel requests are either
6571 * sent with want_reply false or are sent before this handler gets
6574 struct ssh_channel *c;
6577 c = ssh2_channel_msg(ssh, pktin);
6580 wa = c->v.v2.winadj_head;
6582 ssh_disconnect(ssh, NULL, "Received SSH_MSG_CHANNEL_SUCCESS for "
6583 "\"winadj@putty.projects.tartarus.org\"",
6584 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6586 ssh_disconnect(ssh, NULL,
6587 "Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
6588 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6591 static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin)
6594 * The only time this should get called is for "winadj@putty"
6595 * messages sent above. All other channel requests are either
6596 * sent with want_reply false or are sent before this handler gets
6599 struct ssh_channel *c;
6602 c = ssh2_channel_msg(ssh, pktin);
6605 wa = c->v.v2.winadj_head;
6607 ssh_disconnect(ssh, NULL,
6608 "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
6609 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6612 c->v.v2.winadj_head = wa->next;
6613 c->v.v2.remlocwin += wa->size;
6616 * winadj messages are only sent when the window is fully open, so
6617 * if we get an ack of one, we know any pending unthrottle is
6620 if (c->v.v2.throttle_state == UNTHROTTLING)
6621 c->v.v2.throttle_state = UNTHROTTLED;
6624 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6626 struct ssh_channel *c;
6627 c = ssh2_channel_msg(ssh, pktin);
6631 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6632 ssh2_try_send_and_unthrottle(ssh, c);
6636 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6640 struct ssh_channel *c;
6641 c = ssh2_channel_msg(ssh, pktin);
6644 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6645 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6646 return; /* extended but not stderr */
6647 ssh_pkt_getstring(pktin, &data, &length);
6650 c->v.v2.locwindow -= length;
6651 c->v.v2.remlocwin -= length;
6653 case CHAN_MAINSESSION:
6655 from_backend(ssh->frontend, pktin->type ==
6656 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6660 bufsize = x11_send(c->u.x11.s, data, length);
6663 bufsize = pfd_send(c->u.pfd.s, data, length);
6666 while (length > 0) {
6667 if (c->u.a.lensofar < 4) {
6668 unsigned int l = min(4 - c->u.a.lensofar,
6670 memcpy(c->u.a.msglen + c->u.a.lensofar,
6674 c->u.a.lensofar += l;
6676 if (c->u.a.lensofar == 4) {
6678 4 + GET_32BIT(c->u.a.msglen);
6679 c->u.a.message = snewn(c->u.a.totallen,
6681 memcpy(c->u.a.message, c->u.a.msglen, 4);
6683 if (c->u.a.lensofar >= 4 && length > 0) {
6685 min(c->u.a.totallen - c->u.a.lensofar,
6687 memcpy(c->u.a.message + c->u.a.lensofar,
6691 c->u.a.lensofar += l;
6693 if (c->u.a.lensofar == c->u.a.totallen) {
6696 if (agent_query(c->u.a.message,
6699 ssh_agentf_callback, c))
6700 ssh_agentf_callback(c, reply, replylen);
6701 sfree(c->u.a.message);
6702 c->u.a.lensofar = 0;
6709 * If it looks like the remote end hit the end of its window,
6710 * and we didn't want it to do that, think about using a
6713 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6714 c->v.v2.locmaxwin < 0x40000000)
6715 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6717 * If we are not buffering too much data,
6718 * enlarge the window again at the remote side.
6719 * If we are buffering too much, we may still
6720 * need to adjust the window if the server's
6723 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6724 c->v.v2.locmaxwin - bufsize : 0);
6726 * If we're either buffering way too much data, or if we're
6727 * buffering anything at all and we're in "simple" mode,
6728 * throttle the whole channel.
6730 if ((bufsize > c->v.v2.locmaxwin ||
6731 (ssh->cfg.ssh_simple && bufsize > 0)) &&
6732 !c->throttling_conn) {
6733 c->throttling_conn = 1;
6734 ssh_throttle_conn(ssh, +1);
6739 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6741 struct ssh_channel *c;
6743 c = ssh2_channel_msg(ssh, pktin);
6747 if (c->type == CHAN_X11) {
6749 * Remote EOF on an X11 channel means we should
6750 * wrap up and close the channel ourselves.
6752 x11_close(c->u.x11.s);
6755 } else if (c->type == CHAN_AGENT) {
6757 } else if (c->type == CHAN_SOCKDATA) {
6758 pfd_close(c->u.pfd.s);
6764 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6766 struct ssh_channel *c;
6767 struct Packet *pktout;
6769 c = ssh2_channel_msg(ssh, pktin);
6772 /* Do pre-close processing on the channel. */
6774 case CHAN_MAINSESSION:
6775 ssh->mainchan = NULL;
6776 update_specials_menu(ssh->frontend);
6779 if (c->u.x11.s != NULL)
6780 x11_close(c->u.x11.s);
6787 if (c->u.pfd.s != NULL)
6788 pfd_close(c->u.pfd.s);
6792 if (c->closes == 0) {
6793 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6794 ssh2_pkt_adduint32(pktout, c->remoteid);
6795 ssh2_pkt_send(ssh, pktout);
6797 del234(ssh->channels, c);
6798 bufchain_clear(&c->v.v2.outbuffer);
6802 * See if that was the last channel left open.
6803 * (This is only our termination condition if we're
6804 * not running in -N mode.)
6806 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6808 * We used to send SSH_MSG_DISCONNECT here,
6809 * because I'd believed that _every_ conforming
6810 * SSH-2 connection had to end with a disconnect
6811 * being sent by at least one side; apparently
6812 * I was wrong and it's perfectly OK to
6813 * unceremoniously slam the connection shut
6814 * when you're done, and indeed OpenSSH feels
6815 * this is more polite than sending a
6816 * DISCONNECT. So now we don't.
6818 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6822 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6824 struct ssh_channel *c;
6825 struct Packet *pktout;
6827 c = ssh2_channel_msg(ssh, pktin);
6830 if (c->type != CHAN_SOCKDATA_DORMANT)
6831 return; /* dunno why they're confirming this */
6832 c->remoteid = ssh_pkt_getuint32(pktin);
6833 c->halfopen = FALSE;
6834 c->type = CHAN_SOCKDATA;
6835 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6836 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6838 pfd_confirm(c->u.pfd.s);
6841 * We have a pending close on this channel,
6842 * which we decided on before the server acked
6843 * the channel open. So now we know the
6844 * remoteid, we can close it again.
6846 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6847 ssh2_pkt_adduint32(pktout, c->remoteid);
6848 ssh2_pkt_send(ssh, pktout);
6852 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6854 static const char *const reasons[] = {
6855 "<unknown reason code>",
6856 "Administratively prohibited",
6858 "Unknown channel type",
6859 "Resource shortage",
6861 unsigned reason_code;
6862 char *reason_string;
6864 struct ssh_channel *c;
6865 c = ssh2_channel_msg(ssh, pktin);
6868 if (c->type != CHAN_SOCKDATA_DORMANT)
6869 return; /* dunno why they're failing this */
6871 reason_code = ssh_pkt_getuint32(pktin);
6872 if (reason_code >= lenof(reasons))
6873 reason_code = 0; /* ensure reasons[reason_code] in range */
6874 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6875 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6876 reasons[reason_code], reason_length, reason_string);
6878 pfd_close(c->u.pfd.s);
6880 del234(ssh->channels, c);
6884 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6887 int typelen, want_reply;
6888 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6889 struct ssh_channel *c;
6890 struct Packet *pktout;
6892 c = ssh2_channel_msg(ssh, pktin);
6895 ssh_pkt_getstring(pktin, &type, &typelen);
6896 want_reply = ssh2_pkt_getbool(pktin);
6899 * Having got the channel number, we now look at
6900 * the request type string to see if it's something
6903 if (c == ssh->mainchan) {
6905 * We recognise "exit-status" and "exit-signal" on
6906 * the primary channel.
6908 if (typelen == 11 &&
6909 !memcmp(type, "exit-status", 11)) {
6911 ssh->exitcode = ssh_pkt_getuint32(pktin);
6912 logeventf(ssh, "Server sent command exit status %d",
6914 reply = SSH2_MSG_CHANNEL_SUCCESS;
6916 } else if (typelen == 11 &&
6917 !memcmp(type, "exit-signal", 11)) {
6919 int is_plausible = TRUE, is_int = FALSE;
6920 char *fmt_sig = "", *fmt_msg = "";
6922 int msglen = 0, core = FALSE;
6923 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6924 * provide an `int' for the signal, despite its
6925 * having been a `string' in the drafts of RFC 4254 since at
6926 * least 2001. (Fixed in session.c 1.147.) Try to
6927 * infer which we can safely parse it as. */
6929 unsigned char *p = pktin->body +
6931 long len = pktin->length - pktin->savedpos;
6932 unsigned long num = GET_32BIT(p); /* what is it? */
6933 /* If it's 0, it hardly matters; assume string */
6937 int maybe_int = FALSE, maybe_str = FALSE;
6938 #define CHECK_HYPOTHESIS(offset, result) \
6941 if (q >= 0 && q+4 <= len) { \
6942 q = q + 4 + GET_32BIT(p+q); \
6943 if (q >= 0 && q+4 <= len && \
6944 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6948 CHECK_HYPOTHESIS(4+1, maybe_int);
6949 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6950 #undef CHECK_HYPOTHESIS
6951 if (maybe_int && !maybe_str)
6953 else if (!maybe_int && maybe_str)
6956 /* Crikey. Either or neither. Panic. */
6957 is_plausible = FALSE;
6960 ssh->exitcode = 128; /* means `unknown signal' */
6963 /* Old non-standard OpenSSH. */
6964 int signum = ssh_pkt_getuint32(pktin);
6965 fmt_sig = dupprintf(" %d", signum);
6966 ssh->exitcode = 128 + signum;
6968 /* As per RFC 4254. */
6971 ssh_pkt_getstring(pktin, &sig, &siglen);
6972 /* Signal name isn't supposed to be blank, but
6973 * let's cope gracefully if it is. */
6975 fmt_sig = dupprintf(" \"%.*s\"",
6980 * Really hideous method of translating the
6981 * signal description back into a locally
6982 * meaningful number.
6987 #define TRANSLATE_SIGNAL(s) \
6988 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
6989 ssh->exitcode = 128 + SIG ## s
6991 TRANSLATE_SIGNAL(ABRT);
6994 TRANSLATE_SIGNAL(ALRM);
6997 TRANSLATE_SIGNAL(FPE);
7000 TRANSLATE_SIGNAL(HUP);
7003 TRANSLATE_SIGNAL(ILL);
7006 TRANSLATE_SIGNAL(INT);
7009 TRANSLATE_SIGNAL(KILL);
7012 TRANSLATE_SIGNAL(PIPE);
7015 TRANSLATE_SIGNAL(QUIT);
7018 TRANSLATE_SIGNAL(SEGV);
7021 TRANSLATE_SIGNAL(TERM);
7024 TRANSLATE_SIGNAL(USR1);
7027 TRANSLATE_SIGNAL(USR2);
7029 #undef TRANSLATE_SIGNAL
7031 ssh->exitcode = 128;
7033 core = ssh2_pkt_getbool(pktin);
7034 ssh_pkt_getstring(pktin, &msg, &msglen);
7036 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7038 /* ignore lang tag */
7039 } /* else don't attempt to parse */
7040 logeventf(ssh, "Server exited on signal%s%s%s",
7041 fmt_sig, core ? " (core dumped)" : "",
7043 if (*fmt_sig) sfree(fmt_sig);
7044 if (*fmt_msg) sfree(fmt_msg);
7045 reply = SSH2_MSG_CHANNEL_SUCCESS;
7050 * This is a channel request we don't know
7051 * about, so we now either ignore the request
7052 * or respond with CHANNEL_FAILURE, depending
7055 reply = SSH2_MSG_CHANNEL_FAILURE;
7058 pktout = ssh2_pkt_init(reply);
7059 ssh2_pkt_adduint32(pktout, c->remoteid);
7060 ssh2_pkt_send(ssh, pktout);
7064 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7067 int typelen, want_reply;
7068 struct Packet *pktout;
7070 ssh_pkt_getstring(pktin, &type, &typelen);
7071 want_reply = ssh2_pkt_getbool(pktin);
7074 * We currently don't support any global requests
7075 * at all, so we either ignore the request or
7076 * respond with REQUEST_FAILURE, depending on
7080 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7081 ssh2_pkt_send(ssh, pktout);
7085 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7093 struct ssh_channel *c;
7094 unsigned remid, winsize, pktsize;
7095 struct Packet *pktout;
7097 ssh_pkt_getstring(pktin, &type, &typelen);
7098 c = snew(struct ssh_channel);
7101 remid = ssh_pkt_getuint32(pktin);
7102 winsize = ssh_pkt_getuint32(pktin);
7103 pktsize = ssh_pkt_getuint32(pktin);
7105 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7109 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7110 addrstr = snewn(peeraddrlen+1, char);
7111 memcpy(addrstr, peeraddr, peeraddrlen);
7112 addrstr[peeraddrlen] = '\0';
7113 peerport = ssh_pkt_getuint32(pktin);
7115 logeventf(ssh, "Received X11 connect request from %s:%d",
7118 if (!ssh->X11_fwd_enabled)
7119 error = "X11 forwarding is not enabled";
7120 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
7121 addrstr, peerport, &ssh->cfg)) != NULL) {
7122 logeventf(ssh, "Local X11 connection failed: %s", x11err);
7123 error = "Unable to open an X11 connection";
7125 logevent("Opening X11 forward connection succeeded");
7130 } else if (typelen == 15 &&
7131 !memcmp(type, "forwarded-tcpip", 15)) {
7132 struct ssh_rportfwd pf, *realpf;
7135 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7136 pf.sport = ssh_pkt_getuint32(pktin);
7137 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7138 peerport = ssh_pkt_getuint32(pktin);
7139 realpf = find234(ssh->rportfwds, &pf, NULL);
7140 logeventf(ssh, "Received remote port %d open request "
7141 "from %s:%d", pf.sport, peeraddr, peerport);
7142 if (realpf == NULL) {
7143 error = "Remote port is not recognised";
7145 const char *e = pfd_newconnect(&c->u.pfd.s,
7149 realpf->pfrec->addressfamily);
7150 logeventf(ssh, "Attempting to forward remote port to "
7151 "%s:%d", realpf->dhost, realpf->dport);
7153 logeventf(ssh, "Port open failed: %s", e);
7154 error = "Port open failed";
7156 logevent("Forwarded port opened successfully");
7157 c->type = CHAN_SOCKDATA;
7160 } else if (typelen == 22 &&
7161 !memcmp(type, "auth-agent@openssh.com", 22)) {
7162 if (!ssh->agentfwd_enabled)
7163 error = "Agent forwarding is not enabled";
7165 c->type = CHAN_AGENT; /* identify channel type */
7166 c->u.a.lensofar = 0;
7169 error = "Unsupported channel type requested";
7172 c->remoteid = remid;
7173 c->halfopen = FALSE;
7175 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7176 ssh2_pkt_adduint32(pktout, c->remoteid);
7177 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7178 ssh2_pkt_addstring(pktout, error);
7179 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7180 ssh2_pkt_send(ssh, pktout);
7181 logeventf(ssh, "Rejected channel open: %s", error);
7184 ssh2_channel_init(c);
7185 c->v.v2.remwindow = winsize;
7186 c->v.v2.remmaxpkt = pktsize;
7187 add234(ssh->channels, c);
7188 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7189 ssh2_pkt_adduint32(pktout, c->remoteid);
7190 ssh2_pkt_adduint32(pktout, c->localid);
7191 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
7192 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7193 ssh2_pkt_send(ssh, pktout);
7198 * Buffer banner messages for later display at some convenient point,
7199 * if we're going to display them.
7201 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7203 /* Arbitrary limit to prevent unbounded inflation of buffer */
7204 if (ssh->cfg.ssh_show_banner &&
7205 bufchain_size(&ssh->banner) <= 131072) {
7206 char *banner = NULL;
7208 ssh_pkt_getstring(pktin, &banner, &size);
7210 bufchain_add(&ssh->banner, banner, size);
7214 /* Helper function to deal with sending tty modes for "pty-req" */
7215 static void ssh2_send_ttymode(void *data, char *mode, char *val)
7217 struct Packet *pktout = (struct Packet *)data;
7219 unsigned int arg = 0;
7220 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7221 if (i == lenof(ssh_ttymodes)) return;
7222 switch (ssh_ttymodes[i].type) {
7224 arg = ssh_tty_parse_specchar(val);
7227 arg = ssh_tty_parse_boolean(val);
7230 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7231 ssh2_pkt_adduint32(pktout, arg);
7235 * Handle the SSH-2 userauth and connection layers.
7237 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7238 struct Packet *pktin)
7240 struct do_ssh2_authconn_state {
7243 AUTH_TYPE_PUBLICKEY,
7244 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7245 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7248 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7249 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7251 int done_service_req;
7252 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
7253 int tried_pubkey_config, done_agent;
7258 int kbd_inter_refused;
7260 prompts_t *cur_prompt;
7265 void *publickey_blob;
7266 int publickey_bloblen;
7267 int publickey_encrypted;
7268 char *publickey_algorithm;
7269 char *publickey_comment;
7270 unsigned char agent_request[5], *agent_response, *agentp;
7271 int agent_responselen;
7272 unsigned char *pkblob_in_agent;
7274 char *pkblob, *alg, *commentp;
7275 int pklen, alglen, commentlen;
7276 int siglen, retlen, len;
7277 char *q, *agentreq, *ret;
7279 int num_env, env_left, env_ok;
7280 struct Packet *pktout;
7282 struct ssh_gss_library *gsslib;
7283 Ssh_gss_ctx gss_ctx;
7284 Ssh_gss_buf gss_buf;
7285 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7286 Ssh_gss_name gss_srv_name;
7287 Ssh_gss_stat gss_stat;
7290 crState(do_ssh2_authconn_state);
7292 crBegin(ssh->do_ssh2_authconn_crstate);
7294 s->done_service_req = FALSE;
7295 s->we_are_in = FALSE;
7297 s->tried_gssapi = FALSE;
7300 if (!ssh->cfg.ssh_no_userauth) {
7302 * Request userauth protocol, and await a response to it.
7304 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7305 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7306 ssh2_pkt_send(ssh, s->pktout);
7307 crWaitUntilV(pktin);
7308 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7309 s->done_service_req = TRUE;
7311 if (!s->done_service_req) {
7313 * Request connection protocol directly, without authentication.
7315 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7316 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7317 ssh2_pkt_send(ssh, s->pktout);
7318 crWaitUntilV(pktin);
7319 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7320 s->we_are_in = TRUE; /* no auth required */
7322 bombout(("Server refused service request"));
7327 /* Arrange to be able to deal with any BANNERs that come in.
7328 * (We do this now as packets may come in during the next bit.) */
7329 bufchain_init(&ssh->banner);
7330 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7331 ssh2_msg_userauth_banner;
7334 * Misc one-time setup for authentication.
7336 s->publickey_blob = NULL;
7337 if (!s->we_are_in) {
7340 * Load the public half of any configured public key file
7343 if (!filename_is_null(ssh->cfg.keyfile)) {
7345 logeventf(ssh, "Reading private key file \"%.150s\"",
7346 filename_to_str(&ssh->cfg.keyfile));
7347 keytype = key_type(&ssh->cfg.keyfile);
7348 if (keytype == SSH_KEYTYPE_SSH2) {
7351 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
7352 &s->publickey_algorithm,
7353 &s->publickey_bloblen,
7354 &s->publickey_comment, &error);
7355 if (s->publickey_blob) {
7356 s->publickey_encrypted =
7357 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
7360 logeventf(ssh, "Unable to load private key (%s)",
7362 msgbuf = dupprintf("Unable to load private key file "
7363 "\"%.150s\" (%s)\r\n",
7364 filename_to_str(&ssh->cfg.keyfile),
7366 c_write_str(ssh, msgbuf);
7371 logeventf(ssh, "Unable to use this key file (%s)",
7372 key_type_to_str(keytype));
7373 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7375 filename_to_str(&ssh->cfg.keyfile),
7376 key_type_to_str(keytype));
7377 c_write_str(ssh, msgbuf);
7379 s->publickey_blob = NULL;
7384 * Find out about any keys Pageant has (but if there's a
7385 * public key configured, filter out all others).
7388 s->agent_response = NULL;
7389 s->pkblob_in_agent = NULL;
7390 if (ssh->cfg.tryagent && agent_exists()) {
7394 logevent("Pageant is running. Requesting keys.");
7396 /* Request the keys held by the agent. */
7397 PUT_32BIT(s->agent_request, 1);
7398 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7399 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7400 ssh_agent_callback, ssh)) {
7404 bombout(("Unexpected data from server while"
7405 " waiting for agent response"));
7408 } while (pktin || inlen > 0);
7409 r = ssh->agent_response;
7410 s->agent_responselen = ssh->agent_response_len;
7412 s->agent_response = (unsigned char *) r;
7413 if (s->agent_response && s->agent_responselen >= 5 &&
7414 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7417 p = s->agent_response + 5;
7418 s->nkeys = GET_32BIT(p);
7420 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
7421 if (s->publickey_blob) {
7422 /* See if configured key is in agent. */
7423 for (keyi = 0; keyi < s->nkeys; keyi++) {
7424 s->pklen = GET_32BIT(p);
7425 if (s->pklen == s->publickey_bloblen &&
7426 !memcmp(p+4, s->publickey_blob,
7427 s->publickey_bloblen)) {
7428 logeventf(ssh, "Pageant key #%d matches "
7429 "configured key file", keyi);
7431 s->pkblob_in_agent = p;
7435 p += GET_32BIT(p) + 4; /* comment */
7437 if (!s->pkblob_in_agent) {
7438 logevent("Configured key file not in Pageant");
7448 * We repeat this whole loop, including the username prompt,
7449 * until we manage a successful authentication. If the user
7450 * types the wrong _password_, they can be sent back to the
7451 * beginning to try another username, if this is configured on.
7452 * (If they specify a username in the config, they are never
7453 * asked, even if they do give a wrong password.)
7455 * I think this best serves the needs of
7457 * - the people who have no configuration, no keys, and just
7458 * want to try repeated (username,password) pairs until they
7459 * type both correctly
7461 * - people who have keys and configuration but occasionally
7462 * need to fall back to passwords
7464 * - people with a key held in Pageant, who might not have
7465 * logged in to a particular machine before; so they want to
7466 * type a username, and then _either_ their key will be
7467 * accepted, _or_ they will type a password. If they mistype
7468 * the username they will want to be able to get back and
7471 s->username[0] = '\0';
7472 s->got_username = FALSE;
7473 while (!s->we_are_in) {
7477 if (s->got_username && !ssh->cfg.change_username) {
7479 * We got a username last time round this loop, and
7480 * with change_username turned off we don't try to get
7483 } else if (!get_remote_username(&ssh->cfg, s->username,
7484 sizeof(s->username))) {
7485 int ret; /* need not be kept over crReturn */
7486 s->cur_prompt = new_prompts(ssh->frontend);
7487 s->cur_prompt->to_server = TRUE;
7488 s->cur_prompt->name = dupstr("SSH login name");
7489 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
7490 lenof(s->username));
7491 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7494 crWaitUntilV(!pktin);
7495 ret = get_userpass_input(s->cur_prompt, in, inlen);
7500 * get_userpass_input() failed to get a username.
7503 free_prompts(s->cur_prompt);
7504 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7507 memcpy(s->username, s->cur_prompt->prompts[0]->result,
7508 lenof(s->username));
7509 free_prompts(s->cur_prompt);
7512 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7513 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
7514 c_write_str(ssh, stuff);
7518 s->got_username = TRUE;
7521 * Send an authentication request using method "none": (a)
7522 * just in case it succeeds, and (b) so that we know what
7523 * authentication methods we can usefully try next.
7525 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7527 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7528 ssh2_pkt_addstring(s->pktout, s->username);
7529 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7530 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7531 ssh2_pkt_send(ssh, s->pktout);
7532 s->type = AUTH_TYPE_NONE;
7534 s->we_are_in = FALSE;
7536 s->tried_pubkey_config = FALSE;
7537 s->kbd_inter_refused = FALSE;
7539 /* Reset agent request state. */
7540 s->done_agent = FALSE;
7541 if (s->agent_response) {
7542 if (s->pkblob_in_agent) {
7543 s->agentp = s->pkblob_in_agent;
7545 s->agentp = s->agent_response + 5 + 4;
7551 char *methods = NULL;
7555 * Wait for the result of the last authentication request.
7558 crWaitUntilV(pktin);
7560 * Now is a convenient point to spew any banner material
7561 * that we've accumulated. (This should ensure that when
7562 * we exit the auth loop, we haven't any left to deal
7566 int size = bufchain_size(&ssh->banner);
7568 * Don't show the banner if we're operating in
7569 * non-verbose non-interactive mode. (It's probably
7570 * a script, which means nobody will read the
7571 * banner _anyway_, and moreover the printing of
7572 * the banner will screw up processing on the
7573 * output of (say) plink.)
7575 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7576 char *banner = snewn(size, char);
7577 bufchain_fetch(&ssh->banner, banner, size);
7578 c_write_untrusted(ssh, banner, size);
7581 bufchain_clear(&ssh->banner);
7583 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
7584 logevent("Access granted");
7585 s->we_are_in = TRUE;
7589 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
7590 bombout(("Strange packet received during authentication: "
7591 "type %d", pktin->type));
7598 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7599 * we can look at the string in it and know what we can
7600 * helpfully try next.
7602 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
7603 ssh_pkt_getstring(pktin, &methods, &methlen);
7604 if (!ssh2_pkt_getbool(pktin)) {
7606 * We have received an unequivocal Access
7607 * Denied. This can translate to a variety of
7610 * - if we'd just tried "none" authentication,
7611 * it's not worth printing anything at all
7613 * - if we'd just tried a public key _offer_,
7614 * the message should be "Server refused our
7615 * key" (or no message at all if the key
7616 * came from Pageant)
7618 * - if we'd just tried anything else, the
7619 * message really should be "Access denied".
7621 * Additionally, if we'd just tried password
7622 * authentication, we should break out of this
7623 * whole loop so as to go back to the username
7624 * prompt (iff we're configured to allow
7625 * username change attempts).
7627 if (s->type == AUTH_TYPE_NONE) {
7629 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7630 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7631 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7632 c_write_str(ssh, "Server refused our key\r\n");
7633 logevent("Server refused public key");
7634 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
7635 /* server declined keyboard-interactive; ignore */
7637 c_write_str(ssh, "Access denied\r\n");
7638 logevent("Access denied");
7639 if (s->type == AUTH_TYPE_PASSWORD &&
7640 ssh->cfg.change_username) {
7641 /* XXX perhaps we should allow
7642 * keyboard-interactive to do this too? */
7643 s->we_are_in = FALSE;
7648 c_write_str(ssh, "Further authentication required\r\n");
7649 logevent("Further authentication required");
7653 in_commasep_string("publickey", methods, methlen);
7655 in_commasep_string("password", methods, methlen);
7656 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
7657 in_commasep_string("keyboard-interactive", methods, methlen);
7660 ssh->gsslibs = ssh_gss_setup(&ssh->cfg);
7661 s->can_gssapi = ssh->cfg.try_gssapi_auth &&
7662 in_commasep_string("gssapi-with-mic", methods, methlen) &&
7663 ssh->gsslibs->nlibraries > 0;
7667 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7669 if (s->can_pubkey && !s->done_agent && s->nkeys) {
7672 * Attempt public-key authentication using a key from Pageant.
7675 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7677 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7679 /* Unpack key from agent response */
7680 s->pklen = GET_32BIT(s->agentp);
7682 s->pkblob = (char *)s->agentp;
7683 s->agentp += s->pklen;
7684 s->alglen = GET_32BIT(s->pkblob);
7685 s->alg = s->pkblob + 4;
7686 s->commentlen = GET_32BIT(s->agentp);
7688 s->commentp = (char *)s->agentp;
7689 s->agentp += s->commentlen;
7690 /* s->agentp now points at next key, if any */
7692 /* See if server will accept it */
7693 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7694 ssh2_pkt_addstring(s->pktout, s->username);
7695 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7696 /* service requested */
7697 ssh2_pkt_addstring(s->pktout, "publickey");
7699 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7700 ssh2_pkt_addstring_start(s->pktout);
7701 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7702 ssh2_pkt_addstring_start(s->pktout);
7703 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7704 ssh2_pkt_send(ssh, s->pktout);
7705 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
7707 crWaitUntilV(pktin);
7708 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7710 /* Offer of key refused. */
7717 if (flags & FLAG_VERBOSE) {
7718 c_write_str(ssh, "Authenticating with "
7720 c_write(ssh, s->commentp, s->commentlen);
7721 c_write_str(ssh, "\" from agent\r\n");
7725 * Server is willing to accept the key.
7726 * Construct a SIGN_REQUEST.
7728 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7729 ssh2_pkt_addstring(s->pktout, s->username);
7730 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7731 /* service requested */
7732 ssh2_pkt_addstring(s->pktout, "publickey");
7734 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7735 ssh2_pkt_addstring_start(s->pktout);
7736 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7737 ssh2_pkt_addstring_start(s->pktout);
7738 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7740 /* Ask agent for signature. */
7741 s->siglen = s->pktout->length - 5 + 4 +
7742 ssh->v2_session_id_len;
7743 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7745 s->len = 1; /* message type */
7746 s->len += 4 + s->pklen; /* key blob */
7747 s->len += 4 + s->siglen; /* data to sign */
7748 s->len += 4; /* flags */
7749 s->agentreq = snewn(4 + s->len, char);
7750 PUT_32BIT(s->agentreq, s->len);
7751 s->q = s->agentreq + 4;
7752 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
7753 PUT_32BIT(s->q, s->pklen);
7755 memcpy(s->q, s->pkblob, s->pklen);
7757 PUT_32BIT(s->q, s->siglen);
7759 /* Now the data to be signed... */
7760 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7761 PUT_32BIT(s->q, ssh->v2_session_id_len);
7764 memcpy(s->q, ssh->v2_session_id,
7765 ssh->v2_session_id_len);
7766 s->q += ssh->v2_session_id_len;
7767 memcpy(s->q, s->pktout->data + 5,
7768 s->pktout->length - 5);
7769 s->q += s->pktout->length - 5;
7770 /* And finally the (zero) flags word. */
7772 if (!agent_query(s->agentreq, s->len + 4,
7774 ssh_agent_callback, ssh)) {
7778 bombout(("Unexpected data from server"
7779 " while waiting for agent"
7783 } while (pktin || inlen > 0);
7784 vret = ssh->agent_response;
7785 s->retlen = ssh->agent_response_len;
7790 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
7791 logevent("Sending Pageant's response");
7792 ssh2_add_sigblob(ssh, s->pktout,
7793 s->pkblob, s->pklen,
7795 GET_32BIT(s->ret + 5));
7796 ssh2_pkt_send(ssh, s->pktout);
7797 s->type = AUTH_TYPE_PUBLICKEY;
7799 /* FIXME: less drastic response */
7800 bombout(("Pageant failed to answer challenge"));
7806 /* Do we have any keys left to try? */
7807 if (s->pkblob_in_agent) {
7808 s->done_agent = TRUE;
7809 s->tried_pubkey_config = TRUE;
7812 if (s->keyi >= s->nkeys)
7813 s->done_agent = TRUE;
7816 } else if (s->can_pubkey && s->publickey_blob &&
7817 !s->tried_pubkey_config) {
7819 struct ssh2_userkey *key; /* not live over crReturn */
7820 char *passphrase; /* not live over crReturn */
7822 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7824 s->tried_pubkey_config = TRUE;
7827 * Try the public key supplied in the configuration.
7829 * First, offer the public blob to see if the server is
7830 * willing to accept it.
7832 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7833 ssh2_pkt_addstring(s->pktout, s->username);
7834 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7835 /* service requested */
7836 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7837 ssh2_pkt_addbool(s->pktout, FALSE);
7838 /* no signature included */
7839 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7840 ssh2_pkt_addstring_start(s->pktout);
7841 ssh2_pkt_addstring_data(s->pktout,
7842 (char *)s->publickey_blob,
7843 s->publickey_bloblen);
7844 ssh2_pkt_send(ssh, s->pktout);
7845 logevent("Offered public key");
7847 crWaitUntilV(pktin);
7848 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7849 /* Key refused. Give up. */
7850 s->gotit = TRUE; /* reconsider message next loop */
7851 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7852 continue; /* process this new message */
7854 logevent("Offer of public key accepted");
7857 * Actually attempt a serious authentication using
7860 if (flags & FLAG_VERBOSE) {
7861 c_write_str(ssh, "Authenticating with public key \"");
7862 c_write_str(ssh, s->publickey_comment);
7863 c_write_str(ssh, "\"\r\n");
7867 const char *error; /* not live over crReturn */
7868 if (s->publickey_encrypted) {
7870 * Get a passphrase from the user.
7872 int ret; /* need not be kept over crReturn */
7873 s->cur_prompt = new_prompts(ssh->frontend);
7874 s->cur_prompt->to_server = FALSE;
7875 s->cur_prompt->name = dupstr("SSH key passphrase");
7876 add_prompt(s->cur_prompt,
7877 dupprintf("Passphrase for key \"%.100s\": ",
7878 s->publickey_comment),
7879 FALSE, SSH_MAX_PASSWORD_LEN);
7880 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7883 crWaitUntilV(!pktin);
7884 ret = get_userpass_input(s->cur_prompt,
7889 /* Failed to get a passphrase. Terminate. */
7890 free_prompts(s->cur_prompt);
7891 ssh_disconnect(ssh, NULL,
7892 "Unable to authenticate",
7893 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7898 dupstr(s->cur_prompt->prompts[0]->result);
7899 free_prompts(s->cur_prompt);
7901 passphrase = NULL; /* no passphrase needed */
7905 * Try decrypting the key.
7907 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7910 /* burn the evidence */
7911 memset(passphrase, 0, strlen(passphrase));
7914 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7916 (key == SSH2_WRONG_PASSPHRASE)) {
7917 c_write_str(ssh, "Wrong passphrase\r\n");
7919 /* and loop again */
7921 c_write_str(ssh, "Unable to load private key (");
7922 c_write_str(ssh, error);
7923 c_write_str(ssh, ")\r\n");
7925 break; /* try something else */
7931 unsigned char *pkblob, *sigblob, *sigdata;
7932 int pkblob_len, sigblob_len, sigdata_len;
7936 * We have loaded the private key and the server
7937 * has announced that it's willing to accept it.
7938 * Hallelujah. Generate a signature and send it.
7940 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7941 ssh2_pkt_addstring(s->pktout, s->username);
7942 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7943 /* service requested */
7944 ssh2_pkt_addstring(s->pktout, "publickey");
7946 ssh2_pkt_addbool(s->pktout, TRUE);
7947 /* signature follows */
7948 ssh2_pkt_addstring(s->pktout, key->alg->name);
7949 pkblob = key->alg->public_blob(key->data,
7951 ssh2_pkt_addstring_start(s->pktout);
7952 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
7956 * The data to be signed is:
7960 * followed by everything so far placed in the
7963 sigdata_len = s->pktout->length - 5 + 4 +
7964 ssh->v2_session_id_len;
7965 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7967 sigdata = snewn(sigdata_len, unsigned char);
7969 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7970 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7973 memcpy(sigdata+p, ssh->v2_session_id,
7974 ssh->v2_session_id_len);
7975 p += ssh->v2_session_id_len;
7976 memcpy(sigdata+p, s->pktout->data + 5,
7977 s->pktout->length - 5);
7978 p += s->pktout->length - 5;
7979 assert(p == sigdata_len);
7980 sigblob = key->alg->sign(key->data, (char *)sigdata,
7981 sigdata_len, &sigblob_len);
7982 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7983 sigblob, sigblob_len);
7988 ssh2_pkt_send(ssh, s->pktout);
7989 s->type = AUTH_TYPE_PUBLICKEY;
7990 key->alg->freekey(key->data);
7994 } else if (s->can_gssapi && !s->tried_gssapi) {
7996 /* GSSAPI Authentication */
8001 s->type = AUTH_TYPE_GSSAPI;
8002 s->tried_gssapi = TRUE;
8004 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8007 * Pick the highest GSS library on the preference
8013 for (i = 0; i < ngsslibs; i++) {
8014 int want_id = ssh->cfg.ssh_gsslist[i];
8015 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8016 if (ssh->gsslibs->libraries[j].id == want_id) {
8017 s->gsslib = &ssh->gsslibs->libraries[j];
8018 goto got_gsslib; /* double break */
8023 * We always expect to have found something in
8024 * the above loop: we only came here if there
8025 * was at least one viable GSS library, and the
8026 * preference list should always mention
8027 * everything and only change the order.
8032 if (s->gsslib->gsslogmsg)
8033 logevent(s->gsslib->gsslogmsg);
8035 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8036 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8037 ssh2_pkt_addstring(s->pktout, s->username);
8038 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8039 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8041 /* add mechanism info */
8042 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
8044 /* number of GSSAPI mechanisms */
8045 ssh2_pkt_adduint32(s->pktout,1);
8047 /* length of OID + 2 */
8048 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
8049 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8052 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
8054 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8056 ssh2_pkt_send(ssh, s->pktout);
8057 crWaitUntilV(pktin);
8058 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8059 logevent("GSSAPI authentication request refused");
8063 /* check returned packet ... */
8065 ssh_pkt_getstring(pktin, &data, &len);
8066 s->gss_rcvtok.value = data;
8067 s->gss_rcvtok.length = len;
8068 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8069 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8070 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8071 memcmp((char *)s->gss_rcvtok.value + 2,
8072 s->gss_buf.value,s->gss_buf.length) ) {
8073 logevent("GSSAPI authentication - wrong response from server");
8077 /* now start running */
8078 s->gss_stat = s->gsslib->import_name(s->gsslib,
8081 if (s->gss_stat != SSH_GSS_OK) {
8082 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8083 logevent("GSSAPI import name failed - Bad service name");
8085 logevent("GSSAPI import name failed");
8089 /* fetch TGT into GSS engine */
8090 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
8092 if (s->gss_stat != SSH_GSS_OK) {
8093 logevent("GSSAPI authentication failed to get credentials");
8094 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8098 /* initial tokens are empty */
8099 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
8100 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
8102 /* now enter the loop */
8104 s->gss_stat = s->gsslib->init_sec_context
8112 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8113 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8114 logevent("GSSAPI authentication initialisation failed");
8116 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8117 &s->gss_buf) == SSH_GSS_OK) {
8118 logevent(s->gss_buf.value);
8119 sfree(s->gss_buf.value);
8124 logevent("GSSAPI authentication initialised");
8126 /* Client and server now exchange tokens until GSSAPI
8127 * no longer says CONTINUE_NEEDED */
8129 if (s->gss_sndtok.length != 0) {
8130 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8131 ssh_pkt_addstring_start(s->pktout);
8132 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
8133 ssh2_pkt_send(ssh, s->pktout);
8134 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
8137 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8138 crWaitUntilV(pktin);
8139 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8140 logevent("GSSAPI authentication - bad server response");
8141 s->gss_stat = SSH_GSS_FAILURE;
8144 ssh_pkt_getstring(pktin, &data, &len);
8145 s->gss_rcvtok.value = data;
8146 s->gss_rcvtok.length = len;
8148 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8150 if (s->gss_stat != SSH_GSS_OK) {
8151 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8152 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8155 logevent("GSSAPI authentication loop finished OK");
8157 /* Now send the MIC */
8159 s->pktout = ssh2_pkt_init(0);
8160 micoffset = s->pktout->length;
8161 ssh_pkt_addstring_start(s->pktout);
8162 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8163 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
8164 ssh_pkt_addstring(s->pktout, s->username);
8165 ssh_pkt_addstring(s->pktout, "ssh-connection");
8166 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8168 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8169 s->gss_buf.length = s->pktout->length - micoffset;
8171 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
8172 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8173 ssh_pkt_addstring_start(s->pktout);
8174 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
8175 ssh2_pkt_send(ssh, s->pktout);
8176 s->gsslib->free_mic(s->gsslib, &mic);
8180 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8181 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8184 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8187 * Keyboard-interactive authentication.
8190 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8192 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
8194 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8195 ssh2_pkt_addstring(s->pktout, s->username);
8196 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8197 /* service requested */
8198 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8200 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8201 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8202 ssh2_pkt_send(ssh, s->pktout);
8204 crWaitUntilV(pktin);
8205 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8206 /* Server is not willing to do keyboard-interactive
8207 * at all (or, bizarrely but legally, accepts the
8208 * user without actually issuing any prompts).
8209 * Give up on it entirely. */
8211 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
8212 logevent("Keyboard-interactive authentication refused");
8213 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8214 s->kbd_inter_refused = TRUE; /* don't try it again */
8219 * Loop while the server continues to send INFO_REQUESTs.
8221 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
8223 char *name, *inst, *lang;
8224 int name_len, inst_len, lang_len;
8228 * We've got a fresh USERAUTH_INFO_REQUEST.
8229 * Get the preamble and start building a prompt.
8231 ssh_pkt_getstring(pktin, &name, &name_len);
8232 ssh_pkt_getstring(pktin, &inst, &inst_len);
8233 ssh_pkt_getstring(pktin, &lang, &lang_len);
8234 s->cur_prompt = new_prompts(ssh->frontend);
8235 s->cur_prompt->to_server = TRUE;
8238 * Get any prompt(s) from the packet.
8240 s->num_prompts = ssh_pkt_getuint32(pktin);
8241 for (i = 0; i < s->num_prompts; i++) {
8245 static char noprompt[] =
8246 "<server failed to send prompt>: ";
8248 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8249 echo = ssh2_pkt_getbool(pktin);
8252 prompt_len = lenof(noprompt)-1;
8254 add_prompt(s->cur_prompt,
8255 dupprintf("%.*s", prompt_len, prompt),
8256 echo, SSH_MAX_PASSWORD_LEN);
8260 /* FIXME: better prefix to distinguish from
8262 s->cur_prompt->name =
8263 dupprintf("SSH server: %.*s", name_len, name);
8264 s->cur_prompt->name_reqd = TRUE;
8266 s->cur_prompt->name =
8267 dupstr("SSH server authentication");
8268 s->cur_prompt->name_reqd = FALSE;
8270 /* We add a prefix to try to make it clear that a prompt
8271 * has come from the server.
8272 * FIXME: ugly to print "Using..." in prompt _every_
8273 * time round. Can this be done more subtly? */
8274 /* Special case: for reasons best known to themselves,
8275 * some servers send k-i requests with no prompts and
8276 * nothing to display. Keep quiet in this case. */
8277 if (s->num_prompts || name_len || inst_len) {
8278 s->cur_prompt->instruction =
8279 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8280 inst_len ? "\n" : "", inst_len, inst);
8281 s->cur_prompt->instr_reqd = TRUE;
8283 s->cur_prompt->instr_reqd = FALSE;
8287 * Display any instructions, and get the user's
8291 int ret; /* not live over crReturn */
8292 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8295 crWaitUntilV(!pktin);
8296 ret = get_userpass_input(s->cur_prompt, in, inlen);
8301 * Failed to get responses. Terminate.
8303 free_prompts(s->cur_prompt);
8304 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8305 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8312 * Send the response(s) to the server.
8314 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
8315 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8316 for (i=0; i < s->num_prompts; i++) {
8317 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8318 ssh2_pkt_addstring(s->pktout,
8319 s->cur_prompt->prompts[i]->result);
8320 end_log_omission(ssh, s->pktout);
8322 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8325 * Get the next packet in case it's another
8328 crWaitUntilV(pktin);
8333 * We should have SUCCESS or FAILURE now.
8337 } else if (s->can_passwd) {
8340 * Plain old password authentication.
8342 int ret; /* not live over crReturn */
8343 int changereq_first_time; /* not live over crReturn */
8345 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
8347 s->cur_prompt = new_prompts(ssh->frontend);
8348 s->cur_prompt->to_server = TRUE;
8349 s->cur_prompt->name = dupstr("SSH password");
8350 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
8353 FALSE, SSH_MAX_PASSWORD_LEN);
8355 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8358 crWaitUntilV(!pktin);
8359 ret = get_userpass_input(s->cur_prompt, in, inlen);
8364 * Failed to get responses. Terminate.
8366 free_prompts(s->cur_prompt);
8367 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8368 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8373 * Squirrel away the password. (We may need it later if
8374 * asked to change it.)
8376 s->password = dupstr(s->cur_prompt->prompts[0]->result);
8377 free_prompts(s->cur_prompt);
8380 * Send the password packet.
8382 * We pad out the password packet to 256 bytes to make
8383 * it harder for an attacker to find the length of the
8386 * Anyone using a password longer than 256 bytes
8387 * probably doesn't have much to worry about from
8388 * people who find out how long their password is!
8390 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8391 ssh2_pkt_addstring(s->pktout, s->username);
8392 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8393 /* service requested */
8394 ssh2_pkt_addstring(s->pktout, "password");
8395 ssh2_pkt_addbool(s->pktout, FALSE);
8396 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8397 ssh2_pkt_addstring(s->pktout, s->password);
8398 end_log_omission(ssh, s->pktout);
8399 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8400 logevent("Sent password");
8401 s->type = AUTH_TYPE_PASSWORD;
8404 * Wait for next packet, in case it's a password change
8407 crWaitUntilV(pktin);
8408 changereq_first_time = TRUE;
8410 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
8413 * We're being asked for a new password
8414 * (perhaps not for the first time).
8415 * Loop until the server accepts it.
8418 int got_new = FALSE; /* not live over crReturn */
8419 char *prompt; /* not live over crReturn */
8420 int prompt_len; /* not live over crReturn */
8424 if (changereq_first_time)
8425 msg = "Server requested password change";
8427 msg = "Server rejected new password";
8429 c_write_str(ssh, msg);
8430 c_write_str(ssh, "\r\n");
8433 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8435 s->cur_prompt = new_prompts(ssh->frontend);
8436 s->cur_prompt->to_server = TRUE;
8437 s->cur_prompt->name = dupstr("New SSH password");
8438 s->cur_prompt->instruction =
8439 dupprintf("%.*s", prompt_len, prompt);
8440 s->cur_prompt->instr_reqd = TRUE;
8442 * There's no explicit requirement in the protocol
8443 * for the "old" passwords in the original and
8444 * password-change messages to be the same, and
8445 * apparently some Cisco kit supports password change
8446 * by the user entering a blank password originally
8447 * and the real password subsequently, so,
8448 * reluctantly, we prompt for the old password again.
8450 * (On the other hand, some servers don't even bother
8451 * to check this field.)
8453 add_prompt(s->cur_prompt,
8454 dupstr("Current password (blank for previously entered password): "),
8455 FALSE, SSH_MAX_PASSWORD_LEN);
8456 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
8457 FALSE, SSH_MAX_PASSWORD_LEN);
8458 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
8459 FALSE, SSH_MAX_PASSWORD_LEN);
8462 * Loop until the user manages to enter the same
8467 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8470 crWaitUntilV(!pktin);
8471 ret = get_userpass_input(s->cur_prompt, in, inlen);
8476 * Failed to get responses. Terminate.
8478 /* burn the evidence */
8479 free_prompts(s->cur_prompt);
8480 memset(s->password, 0, strlen(s->password));
8482 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8483 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8489 * If the user specified a new original password
8490 * (IYSWIM), overwrite any previously specified
8492 * (A side effect is that the user doesn't have to
8493 * re-enter it if they louse up the new password.)
8495 if (s->cur_prompt->prompts[0]->result[0]) {
8496 memset(s->password, 0, strlen(s->password));
8497 /* burn the evidence */
8500 dupstr(s->cur_prompt->prompts[0]->result);
8504 * Check the two new passwords match.
8506 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
8507 s->cur_prompt->prompts[2]->result)
8510 /* They don't. Silly user. */
8511 c_write_str(ssh, "Passwords do not match\r\n");
8516 * Send the new password (along with the old one).
8517 * (see above for padding rationale)
8519 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8520 ssh2_pkt_addstring(s->pktout, s->username);
8521 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8522 /* service requested */
8523 ssh2_pkt_addstring(s->pktout, "password");
8524 ssh2_pkt_addbool(s->pktout, TRUE);
8525 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8526 ssh2_pkt_addstring(s->pktout, s->password);
8527 ssh2_pkt_addstring(s->pktout,
8528 s->cur_prompt->prompts[1]->result);
8529 free_prompts(s->cur_prompt);
8530 end_log_omission(ssh, s->pktout);
8531 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8532 logevent("Sent new password");
8535 * Now see what the server has to say about it.
8536 * (If it's CHANGEREQ again, it's not happy with the
8539 crWaitUntilV(pktin);
8540 changereq_first_time = FALSE;
8545 * We need to reexamine the current pktin at the top
8546 * of the loop. Either:
8547 * - we weren't asked to change password at all, in
8548 * which case it's a SUCCESS or FAILURE with the
8550 * - we sent a new password, and the server was
8551 * either OK with it (SUCCESS or FAILURE w/partial
8552 * success) or unhappy with the _old_ password
8553 * (FAILURE w/o partial success)
8554 * In any of these cases, we go back to the top of
8555 * the loop and start again.
8560 * We don't need the old password any more, in any
8561 * case. Burn the evidence.
8563 memset(s->password, 0, strlen(s->password));
8567 char *str = dupprintf("No supported authentication methods available"
8568 " (server sent: %.*s)",
8571 ssh_disconnect(ssh, str,
8572 "No supported authentication methods available",
8573 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
8583 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
8585 /* Clear up various bits and pieces from authentication. */
8586 if (s->publickey_blob) {
8587 sfree(s->publickey_blob);
8588 sfree(s->publickey_comment);
8590 if (s->agent_response)
8591 sfree(s->agent_response);
8594 * Now the connection protocol has started, one way or another.
8597 ssh->channels = newtree234(ssh_channelcmp);
8600 * Set up handlers for some connection protocol messages, so we
8601 * don't have to handle them repeatedly in this coroutine.
8603 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
8604 ssh2_msg_channel_window_adjust;
8605 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
8606 ssh2_msg_global_request;
8609 * Create the main session channel.
8611 if (ssh->cfg.ssh_no_shell) {
8612 ssh->mainchan = NULL;
8613 } else if (*ssh->cfg.ssh_nc_host) {
8615 * Just start a direct-tcpip channel and use it as the main
8618 ssh->mainchan = snew(struct ssh_channel);
8619 ssh->mainchan->ssh = ssh;
8620 ssh2_channel_init(ssh->mainchan);
8622 "Opening direct-tcpip channel to %s:%d in place of session",
8623 ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port);
8624 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8625 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
8626 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
8627 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8628 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8629 ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host);
8630 ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port);
8632 * There's nothing meaningful to put in the originator
8633 * fields, but some servers insist on syntactically correct
8636 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
8637 ssh2_pkt_adduint32(s->pktout, 0);
8638 ssh2_pkt_send(ssh, s->pktout);
8640 crWaitUntilV(pktin);
8641 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8642 bombout(("Server refused to open a direct-tcpip channel"));
8644 /* FIXME: error data comes back in FAILURE packet */
8646 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8647 bombout(("Server's channel confirmation cited wrong channel"));
8650 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8651 ssh->mainchan->halfopen = FALSE;
8652 ssh->mainchan->type = CHAN_MAINSESSION;
8653 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8654 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8655 add234(ssh->channels, ssh->mainchan);
8656 update_specials_menu(ssh->frontend);
8657 logevent("Opened direct-tcpip channel");
8660 ssh->mainchan = snew(struct ssh_channel);
8661 ssh->mainchan->ssh = ssh;
8662 ssh2_channel_init(ssh->mainchan);
8663 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8664 ssh2_pkt_addstring(s->pktout, "session");
8665 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
8666 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8667 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8668 ssh2_pkt_send(ssh, s->pktout);
8669 crWaitUntilV(pktin);
8670 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8671 bombout(("Server refused to open a session"));
8673 /* FIXME: error data comes back in FAILURE packet */
8675 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8676 bombout(("Server's channel confirmation cited wrong channel"));
8679 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8680 ssh->mainchan->halfopen = FALSE;
8681 ssh->mainchan->type = CHAN_MAINSESSION;
8682 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8683 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8684 add234(ssh->channels, ssh->mainchan);
8685 update_specials_menu(ssh->frontend);
8686 logevent("Opened channel for session");
8687 ssh->ncmode = FALSE;
8691 * Now we have a channel, make dispatch table entries for
8692 * general channel-based messages.
8694 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8695 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8696 ssh2_msg_channel_data;
8697 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8698 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8699 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8700 ssh2_msg_channel_open_confirmation;
8701 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8702 ssh2_msg_channel_open_failure;
8703 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8704 ssh2_msg_channel_request;
8705 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8706 ssh2_msg_channel_open;
8708 if (ssh->mainchan && ssh->cfg.ssh_simple) {
8710 * This message indicates to the server that we promise
8711 * not to try to run any other channel in parallel with
8712 * this one, so it's safe for it to advertise a very large
8713 * window and leave the flow control to TCP.
8715 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8716 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8717 ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
8718 ssh2_pkt_addbool(s->pktout, 0); /* no reply */
8719 ssh2_pkt_send(ssh, s->pktout);
8723 * Potentially enable X11 forwarding.
8725 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward &&
8726 (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
8727 ssh->cfg.x11_auth, &ssh->cfg))) {
8728 logevent("Requesting X11 forwarding");
8729 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8730 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8731 ssh2_pkt_addstring(s->pktout, "x11-req");
8732 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8733 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8734 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname);
8736 * Note that while we blank the X authentication data here, we don't
8737 * take any special action to blank the start of an X11 channel,
8738 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
8739 * without having session blanking enabled is likely to leak your
8740 * cookie into the log.
8742 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8743 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring);
8744 end_log_omission(ssh, s->pktout);
8745 ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum);
8746 ssh2_pkt_send(ssh, s->pktout);
8748 crWaitUntilV(pktin);
8750 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8751 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8752 bombout(("Unexpected response to X11 forwarding request:"
8753 " packet type %d", pktin->type));
8756 logevent("X11 forwarding refused");
8758 logevent("X11 forwarding enabled");
8759 ssh->X11_fwd_enabled = TRUE;
8764 * Enable port forwardings.
8766 ssh_setup_portfwd(ssh, &ssh->cfg);
8769 * Potentially enable agent forwarding.
8771 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) {
8772 logevent("Requesting OpenSSH-style agent forwarding");
8773 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8774 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8775 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
8776 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8777 ssh2_pkt_send(ssh, s->pktout);
8779 crWaitUntilV(pktin);
8781 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8782 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8783 bombout(("Unexpected response to agent forwarding request:"
8784 " packet type %d", pktin->type));
8787 logevent("Agent forwarding refused");
8789 logevent("Agent forwarding enabled");
8790 ssh->agentfwd_enabled = TRUE;
8795 * Now allocate a pty for the session.
8797 if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) {
8798 /* Unpick the terminal-speed string. */
8799 /* XXX perhaps we should allow no speeds to be sent. */
8800 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8801 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
8802 /* Build the pty request. */
8803 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8804 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8805 ssh2_pkt_addstring(s->pktout, "pty-req");
8806 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8807 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
8808 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
8809 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
8810 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
8811 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
8812 ssh2_pkt_addstring_start(s->pktout);
8813 parse_ttymodes(ssh, ssh->cfg.ttymodes,
8814 ssh2_send_ttymode, (void *)s->pktout);
8815 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
8816 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
8817 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
8818 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
8819 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
8820 ssh2_pkt_send(ssh, s->pktout);
8821 ssh->state = SSH_STATE_INTERMED;
8823 crWaitUntilV(pktin);
8825 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8826 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8827 bombout(("Unexpected response to pty request:"
8828 " packet type %d", pktin->type));
8831 c_write_str(ssh, "Server refused to allocate pty\r\n");
8832 ssh->editing = ssh->echoing = 1;
8834 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8835 ssh->ospeed, ssh->ispeed);
8838 ssh->editing = ssh->echoing = 1;
8842 * Send environment variables.
8844 * Simplest thing here is to send all the requests at once, and
8845 * then wait for a whole bunch of successes or failures.
8847 if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) {
8848 char *e = ssh->cfg.environmt;
8849 char *var, *varend, *val;
8855 while (*e && *e != '\t') e++;
8857 if (*e == '\t') e++;
8862 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8863 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8864 ssh2_pkt_addstring(s->pktout, "env");
8865 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8866 ssh2_pkt_addstring_start(s->pktout);
8867 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
8868 ssh2_pkt_addstring(s->pktout, val);
8869 ssh2_pkt_send(ssh, s->pktout);
8874 logeventf(ssh, "Sent %d environment variables", s->num_env);
8877 s->env_left = s->num_env;
8879 while (s->env_left > 0) {
8880 crWaitUntilV(pktin);
8882 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8883 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8884 bombout(("Unexpected response to environment request:"
8885 " packet type %d", pktin->type));
8895 if (s->env_ok == s->num_env) {
8896 logevent("All environment variables successfully set");
8897 } else if (s->env_ok == 0) {
8898 logevent("All environment variables refused");
8899 c_write_str(ssh, "Server refused to set environment variables\r\n");
8901 logeventf(ssh, "%d environment variables refused",
8902 s->num_env - s->env_ok);
8903 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8908 * Start a shell or a remote command. We may have to attempt
8909 * this twice if the config data has provided a second choice
8912 if (ssh->mainchan && !ssh->ncmode) while (1) {
8916 if (ssh->fallback_cmd) {
8917 subsys = ssh->cfg.ssh_subsys2;
8918 cmd = ssh->cfg.remote_cmd_ptr2;
8920 subsys = ssh->cfg.ssh_subsys;
8921 cmd = ssh->cfg.remote_cmd_ptr;
8922 if (!cmd) cmd = ssh->cfg.remote_cmd;
8925 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8926 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8928 ssh2_pkt_addstring(s->pktout, "subsystem");
8929 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8930 ssh2_pkt_addstring(s->pktout, cmd);
8932 ssh2_pkt_addstring(s->pktout, "exec");
8933 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8934 ssh2_pkt_addstring(s->pktout, cmd);
8936 ssh2_pkt_addstring(s->pktout, "shell");
8937 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8939 ssh2_pkt_send(ssh, s->pktout);
8941 crWaitUntilV(pktin);
8943 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8944 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8945 bombout(("Unexpected response to shell/command request:"
8946 " packet type %d", pktin->type));
8950 * We failed to start the command. If this is the
8951 * fallback command, we really are finished; if it's
8952 * not, and if the fallback command exists, try falling
8953 * back to it before complaining.
8955 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
8956 logevent("Primary command failed; attempting fallback");
8957 ssh->fallback_cmd = TRUE;
8960 bombout(("Server refused to start a shell/command"));
8963 logevent("Started a shell/command");
8968 ssh->state = SSH_STATE_SESSION;
8969 if (ssh->size_needed)
8970 ssh_size(ssh, ssh->term_width, ssh->term_height);
8971 if (ssh->eof_needed)
8972 ssh_special(ssh, TS_EOF);
8975 * All the initial channel requests are done, so install the default
8978 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success;
8979 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure;
8985 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
8990 s->try_send = FALSE;
8994 * _All_ the connection-layer packets we expect to
8995 * receive are now handled by the dispatch table.
8996 * Anything that reaches here must be bogus.
8999 bombout(("Strange packet received: type %d", pktin->type));
9001 } else if (ssh->mainchan) {
9003 * We have spare data. Add it to the channel buffer.
9005 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
9010 struct ssh_channel *c;
9012 * Try to send data on all channels if we can.
9014 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
9015 ssh2_try_send_and_unthrottle(ssh, c);
9023 * Handlers for SSH-2 messages that might arrive at any moment.
9025 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
9027 /* log reason code in disconnect message */
9031 reason = ssh_pkt_getuint32(pktin);
9032 ssh_pkt_getstring(pktin, &msg, &msglen);
9034 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9035 buf = dupprintf("Received disconnect message (%s)",
9036 ssh2_disconnect_reasons[reason]);
9038 buf = dupprintf("Received disconnect message (unknown"
9039 " type %d)", reason);
9043 buf = dupprintf("Disconnection message text: %.*s",
9046 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9048 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9049 ssh2_disconnect_reasons[reason] : "unknown",
9054 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
9056 /* log the debug message */
9061 /* XXX maybe we should actually take notice of this */
9062 always_display = ssh2_pkt_getbool(pktin);
9063 ssh_pkt_getstring(pktin, &msg, &msglen);
9065 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
9068 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
9070 struct Packet *pktout;
9071 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9072 ssh2_pkt_adduint32(pktout, pktin->sequence);
9074 * UNIMPLEMENTED messages MUST appear in the same order as the
9075 * messages they respond to. Hence, never queue them.
9077 ssh2_pkt_send_noqueue(ssh, pktout);
9081 * Handle the top-level SSH-2 protocol.
9083 static void ssh2_protocol_setup(Ssh ssh)
9088 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9090 for (i = 0; i < 256; i++)
9091 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9094 * Any message we actually understand, we set to NULL so that
9095 * the coroutines will get it.
9097 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
9098 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
9099 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
9100 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
9101 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
9102 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
9103 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
9104 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
9105 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
9106 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
9107 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
9108 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
9109 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
9110 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
9111 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9112 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
9113 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
9114 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
9115 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
9116 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
9117 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
9118 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
9119 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
9120 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
9121 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
9122 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
9123 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
9124 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
9125 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
9126 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
9127 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
9128 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
9129 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
9132 * These special message types we install handlers for.
9134 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
9135 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
9136 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9139 static void ssh2_timer(void *ctx, long now)
9143 if (ssh->state == SSH_STATE_CLOSED)
9146 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9147 now - ssh->next_rekey >= 0) {
9148 do_ssh2_transport(ssh, "timeout", -1, NULL);
9152 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
9153 struct Packet *pktin)
9155 unsigned char *in = (unsigned char *)vin;
9156 if (ssh->state == SSH_STATE_CLOSED)
9160 ssh->incoming_data_size += pktin->encrypted_len;
9161 if (!ssh->kex_in_progress &&
9162 ssh->max_data_size != 0 &&
9163 ssh->incoming_data_size > ssh->max_data_size)
9164 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9167 if (pktin && ssh->packet_dispatch[pktin->type]) {
9168 ssh->packet_dispatch[pktin->type](ssh, pktin);
9172 if (!ssh->protocol_initial_phase_done ||
9173 (pktin && pktin->type >= 20 && pktin->type < 50)) {
9174 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
9175 !ssh->protocol_initial_phase_done) {
9176 ssh->protocol_initial_phase_done = TRUE;
9178 * Allow authconn to initialise itself.
9180 do_ssh2_authconn(ssh, NULL, 0, NULL);
9183 do_ssh2_authconn(ssh, in, inlen, pktin);
9188 * Called to set up the connection.
9190 * Returns an error message, or NULL on success.
9192 static const char *ssh_init(void *frontend_handle, void **backend_handle,
9194 char *host, int port, char **realhost, int nodelay,
9200 ssh = snew(struct ssh_tag);
9201 ssh->cfg = *cfg; /* STRUCTURE COPY */
9202 ssh->version = 0; /* when not ready yet */
9205 ssh->v1_cipher_ctx = NULL;
9206 ssh->crcda_ctx = NULL;
9207 ssh->cscipher = NULL;
9208 ssh->cs_cipher_ctx = NULL;
9209 ssh->sccipher = NULL;
9210 ssh->sc_cipher_ctx = NULL;
9212 ssh->cs_mac_ctx = NULL;
9214 ssh->sc_mac_ctx = NULL;
9216 ssh->cs_comp_ctx = NULL;
9218 ssh->sc_comp_ctx = NULL;
9220 ssh->kex_ctx = NULL;
9221 ssh->hostkey = NULL;
9223 ssh->close_expected = FALSE;
9224 ssh->clean_exit = FALSE;
9225 ssh->state = SSH_STATE_PREPACKET;
9226 ssh->size_needed = FALSE;
9227 ssh->eof_needed = FALSE;
9230 ssh->deferred_send_data = NULL;
9231 ssh->deferred_len = 0;
9232 ssh->deferred_size = 0;
9233 ssh->fallback_cmd = 0;
9234 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9235 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9236 ssh->x11disp = NULL;
9237 ssh->v1_compressing = FALSE;
9238 ssh->v2_outgoing_sequence = 0;
9239 ssh->ssh1_rdpkt_crstate = 0;
9240 ssh->ssh2_rdpkt_crstate = 0;
9241 ssh->do_ssh_init_crstate = 0;
9242 ssh->ssh_gotdata_crstate = 0;
9243 ssh->do_ssh1_connection_crstate = 0;
9244 ssh->do_ssh1_login_crstate = 0;
9245 ssh->do_ssh2_transport_crstate = 0;
9246 ssh->do_ssh2_authconn_crstate = 0;
9247 ssh->do_ssh_init_state = NULL;
9248 ssh->do_ssh1_login_state = NULL;
9249 ssh->do_ssh2_transport_state = NULL;
9250 ssh->do_ssh2_authconn_state = NULL;
9253 ssh->mainchan = NULL;
9254 ssh->throttled_all = 0;
9255 ssh->v1_stdout_throttling = 0;
9257 ssh->queuelen = ssh->queuesize = 0;
9258 ssh->queueing = FALSE;
9259 ssh->qhead = ssh->qtail = NULL;
9260 ssh->deferred_rekey_reason = NULL;
9261 bufchain_init(&ssh->queued_incoming_data);
9262 ssh->frozen = FALSE;
9264 *backend_handle = ssh;
9267 if (crypto_startup() == 0)
9268 return "Microsoft high encryption pack not installed!";
9271 ssh->frontend = frontend_handle;
9272 ssh->term_width = ssh->cfg.width;
9273 ssh->term_height = ssh->cfg.height;
9275 ssh->channels = NULL;
9276 ssh->rportfwds = NULL;
9277 ssh->portfwds = NULL;
9282 ssh->conn_throttle_count = 0;
9283 ssh->overall_bufsize = 0;
9284 ssh->fallback_cmd = 0;
9286 ssh->protocol = NULL;
9288 ssh->protocol_initial_phase_done = FALSE;
9292 ssh->incoming_data_size = ssh->outgoing_data_size =
9293 ssh->deferred_data_size = 0L;
9294 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9295 ssh->kex_in_progress = FALSE;
9298 ssh->gsslibs = NULL;
9301 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
9310 static void ssh_free(void *handle)
9312 Ssh ssh = (Ssh) handle;
9313 struct ssh_channel *c;
9314 struct ssh_rportfwd *pf;
9316 if (ssh->v1_cipher_ctx)
9317 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9318 if (ssh->cs_cipher_ctx)
9319 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9320 if (ssh->sc_cipher_ctx)
9321 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9322 if (ssh->cs_mac_ctx)
9323 ssh->csmac->free_context(ssh->cs_mac_ctx);
9324 if (ssh->sc_mac_ctx)
9325 ssh->scmac->free_context(ssh->sc_mac_ctx);
9326 if (ssh->cs_comp_ctx) {
9328 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9330 zlib_compress_cleanup(ssh->cs_comp_ctx);
9332 if (ssh->sc_comp_ctx) {
9334 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9336 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9339 dh_cleanup(ssh->kex_ctx);
9340 sfree(ssh->savedhost);
9342 while (ssh->queuelen-- > 0)
9343 ssh_free_packet(ssh->queue[ssh->queuelen]);
9346 while (ssh->qhead) {
9347 struct queued_handler *qh = ssh->qhead;
9348 ssh->qhead = qh->next;
9351 ssh->qhead = ssh->qtail = NULL;
9353 if (ssh->channels) {
9354 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9357 if (c->u.x11.s != NULL)
9358 x11_close(c->u.x11.s);
9361 case CHAN_SOCKDATA_DORMANT:
9362 if (c->u.pfd.s != NULL)
9363 pfd_close(c->u.pfd.s);
9368 freetree234(ssh->channels);
9369 ssh->channels = NULL;
9372 if (ssh->rportfwds) {
9373 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
9375 freetree234(ssh->rportfwds);
9376 ssh->rportfwds = NULL;
9378 sfree(ssh->deferred_send_data);
9380 x11_free_display(ssh->x11disp);
9381 sfree(ssh->do_ssh_init_state);
9382 sfree(ssh->do_ssh1_login_state);
9383 sfree(ssh->do_ssh2_transport_state);
9384 sfree(ssh->do_ssh2_authconn_state);
9387 sfree(ssh->fullhostname);
9388 if (ssh->crcda_ctx) {
9389 crcda_free_context(ssh->crcda_ctx);
9390 ssh->crcda_ctx = NULL;
9393 ssh_do_close(ssh, TRUE);
9394 expire_timer_context(ssh);
9396 pinger_free(ssh->pinger);
9397 bufchain_clear(&ssh->queued_incoming_data);
9400 ssh_gss_cleanup(ssh->gsslibs);
9408 * Reconfigure the SSH backend.
9410 static void ssh_reconfig(void *handle, Config *cfg)
9412 Ssh ssh = (Ssh) handle;
9413 char *rekeying = NULL, rekey_mandatory = FALSE;
9414 unsigned long old_max_data_size;
9416 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
9418 ssh_setup_portfwd(ssh, cfg);
9420 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
9421 cfg->ssh_rekey_time != 0) {
9422 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
9423 long now = GETTICKCOUNT();
9425 if (new_next - now < 0) {
9426 rekeying = "timeout shortened";
9428 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9432 old_max_data_size = ssh->max_data_size;
9433 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
9434 if (old_max_data_size != ssh->max_data_size &&
9435 ssh->max_data_size != 0) {
9436 if (ssh->outgoing_data_size > ssh->max_data_size ||
9437 ssh->incoming_data_size > ssh->max_data_size)
9438 rekeying = "data limit lowered";
9441 if (ssh->cfg.compression != cfg->compression) {
9442 rekeying = "compression setting changed";
9443 rekey_mandatory = TRUE;
9446 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
9447 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
9448 sizeof(ssh->cfg.ssh_cipherlist))) {
9449 rekeying = "cipher settings changed";
9450 rekey_mandatory = TRUE;
9453 ssh->cfg = *cfg; /* STRUCTURE COPY */
9456 if (!ssh->kex_in_progress) {
9457 do_ssh2_transport(ssh, rekeying, -1, NULL);
9458 } else if (rekey_mandatory) {
9459 ssh->deferred_rekey_reason = rekeying;
9465 * Called to send data down the SSH connection.
9467 static int ssh_send(void *handle, char *buf, int len)
9469 Ssh ssh = (Ssh) handle;
9471 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
9474 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
9476 return ssh_sendbuffer(ssh);
9480 * Called to query the current amount of buffered stdin data.
9482 static int ssh_sendbuffer(void *handle)
9484 Ssh ssh = (Ssh) handle;
9487 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
9491 * If the SSH socket itself has backed up, add the total backup
9492 * size on that to any individual buffer on the stdin channel.
9495 if (ssh->throttled_all)
9496 override_value = ssh->overall_bufsize;
9498 if (ssh->version == 1) {
9499 return override_value;
9500 } else if (ssh->version == 2) {
9501 if (!ssh->mainchan || ssh->mainchan->closes > 0)
9502 return override_value;
9504 return (override_value +
9505 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
9512 * Called to set the size of the window from SSH's POV.
9514 static void ssh_size(void *handle, int width, int height)
9516 Ssh ssh = (Ssh) handle;
9517 struct Packet *pktout;
9519 ssh->term_width = width;
9520 ssh->term_height = height;
9522 switch (ssh->state) {
9523 case SSH_STATE_BEFORE_SIZE:
9524 case SSH_STATE_PREPACKET:
9525 case SSH_STATE_CLOSED:
9526 break; /* do nothing */
9527 case SSH_STATE_INTERMED:
9528 ssh->size_needed = TRUE; /* buffer for later */
9530 case SSH_STATE_SESSION:
9531 if (!ssh->cfg.nopty) {
9532 if (ssh->version == 1) {
9533 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
9534 PKT_INT, ssh->term_height,
9535 PKT_INT, ssh->term_width,
9536 PKT_INT, 0, PKT_INT, 0, PKT_END);
9537 } else if (ssh->mainchan) {
9538 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9539 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9540 ssh2_pkt_addstring(pktout, "window-change");
9541 ssh2_pkt_addbool(pktout, 0);
9542 ssh2_pkt_adduint32(pktout, ssh->term_width);
9543 ssh2_pkt_adduint32(pktout, ssh->term_height);
9544 ssh2_pkt_adduint32(pktout, 0);
9545 ssh2_pkt_adduint32(pktout, 0);
9546 ssh2_pkt_send(ssh, pktout);
9554 * Return a list of the special codes that make sense in this
9557 static const struct telnet_special *ssh_get_specials(void *handle)
9559 static const struct telnet_special ssh1_ignore_special[] = {
9560 {"IGNORE message", TS_NOP}
9562 static const struct telnet_special ssh2_ignore_special[] = {
9563 {"IGNORE message", TS_NOP},
9565 static const struct telnet_special ssh2_rekey_special[] = {
9566 {"Repeat key exchange", TS_REKEY},
9568 static const struct telnet_special ssh2_session_specials[] = {
9571 /* These are the signal names defined by RFC 4254.
9572 * They include all the ISO C signals, but are a subset of the POSIX
9573 * required signals. */
9574 {"SIGINT (Interrupt)", TS_SIGINT},
9575 {"SIGTERM (Terminate)", TS_SIGTERM},
9576 {"SIGKILL (Kill)", TS_SIGKILL},
9577 {"SIGQUIT (Quit)", TS_SIGQUIT},
9578 {"SIGHUP (Hangup)", TS_SIGHUP},
9579 {"More signals", TS_SUBMENU},
9580 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
9581 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
9582 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
9583 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
9586 static const struct telnet_special specials_end[] = {
9589 /* XXX review this length for any changes: */
9590 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
9591 lenof(ssh2_rekey_special) +
9592 lenof(ssh2_session_specials) +
9593 lenof(specials_end)];
9594 Ssh ssh = (Ssh) handle;
9596 #define ADD_SPECIALS(name) \
9598 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9599 memcpy(&ssh_specials[i], name, sizeof name); \
9603 if (ssh->version == 1) {
9604 /* Don't bother offering IGNORE if we've decided the remote
9605 * won't cope with it, since we wouldn't bother sending it if
9607 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9608 ADD_SPECIALS(ssh1_ignore_special);
9609 } else if (ssh->version == 2) {
9610 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
9611 ADD_SPECIALS(ssh2_ignore_special);
9612 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
9613 ADD_SPECIALS(ssh2_rekey_special);
9615 ADD_SPECIALS(ssh2_session_specials);
9616 } /* else we're not ready yet */
9619 ADD_SPECIALS(specials_end);
9620 return ssh_specials;
9628 * Send special codes. TS_EOF is useful for `plink', so you
9629 * can send an EOF and collect resulting output (e.g. `plink
9632 static void ssh_special(void *handle, Telnet_Special code)
9634 Ssh ssh = (Ssh) handle;
9635 struct Packet *pktout;
9637 if (code == TS_EOF) {
9638 if (ssh->state != SSH_STATE_SESSION) {
9640 * Buffer the EOF in case we are pre-SESSION, so we can
9641 * send it as soon as we reach SESSION.
9644 ssh->eof_needed = TRUE;
9647 if (ssh->version == 1) {
9648 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
9649 } else if (ssh->mainchan) {
9650 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
9651 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9652 ssh2_pkt_send(ssh, pktout);
9653 ssh->send_ok = 0; /* now stop trying to read from stdin */
9655 logevent("Sent EOF message");
9656 } else if (code == TS_PING || code == TS_NOP) {
9657 if (ssh->state == SSH_STATE_CLOSED
9658 || ssh->state == SSH_STATE_PREPACKET) return;
9659 if (ssh->version == 1) {
9660 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9661 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
9663 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
9664 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
9665 ssh2_pkt_addstring_start(pktout);
9666 ssh2_pkt_send_noqueue(ssh, pktout);
9669 } else if (code == TS_REKEY) {
9670 if (!ssh->kex_in_progress && ssh->version == 2) {
9671 do_ssh2_transport(ssh, "at user request", -1, NULL);
9673 } else if (code == TS_BRK) {
9674 if (ssh->state == SSH_STATE_CLOSED
9675 || ssh->state == SSH_STATE_PREPACKET) return;
9676 if (ssh->version == 1) {
9677 logevent("Unable to send BREAK signal in SSH-1");
9678 } else if (ssh->mainchan) {
9679 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9680 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9681 ssh2_pkt_addstring(pktout, "break");
9682 ssh2_pkt_addbool(pktout, 0);
9683 ssh2_pkt_adduint32(pktout, 0); /* default break length */
9684 ssh2_pkt_send(ssh, pktout);
9687 /* Is is a POSIX signal? */
9688 char *signame = NULL;
9689 if (code == TS_SIGABRT) signame = "ABRT";
9690 if (code == TS_SIGALRM) signame = "ALRM";
9691 if (code == TS_SIGFPE) signame = "FPE";
9692 if (code == TS_SIGHUP) signame = "HUP";
9693 if (code == TS_SIGILL) signame = "ILL";
9694 if (code == TS_SIGINT) signame = "INT";
9695 if (code == TS_SIGKILL) signame = "KILL";
9696 if (code == TS_SIGPIPE) signame = "PIPE";
9697 if (code == TS_SIGQUIT) signame = "QUIT";
9698 if (code == TS_SIGSEGV) signame = "SEGV";
9699 if (code == TS_SIGTERM) signame = "TERM";
9700 if (code == TS_SIGUSR1) signame = "USR1";
9701 if (code == TS_SIGUSR2) signame = "USR2";
9702 /* The SSH-2 protocol does in principle support arbitrary named
9703 * signals, including signame@domain, but we don't support those. */
9705 /* It's a signal. */
9706 if (ssh->version == 2 && ssh->mainchan) {
9707 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9708 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9709 ssh2_pkt_addstring(pktout, "signal");
9710 ssh2_pkt_addbool(pktout, 0);
9711 ssh2_pkt_addstring(pktout, signame);
9712 ssh2_pkt_send(ssh, pktout);
9713 logeventf(ssh, "Sent signal SIG%s", signame);
9716 /* Never heard of it. Do nothing */
9721 void *new_sock_channel(void *handle, Socket s)
9723 Ssh ssh = (Ssh) handle;
9724 struct ssh_channel *c;
9725 c = snew(struct ssh_channel);
9728 ssh2_channel_init(c);
9730 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
9732 add234(ssh->channels, c);
9737 * This is called when stdout/stderr (the entity to which
9738 * from_backend sends data) manages to clear some backlog.
9740 static void ssh_unthrottle(void *handle, int bufsize)
9742 Ssh ssh = (Ssh) handle;
9745 if (ssh->version == 1) {
9746 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
9747 ssh->v1_stdout_throttling = 0;
9748 ssh_throttle_conn(ssh, -1);
9751 if (ssh->mainchan) {
9752 ssh2_set_window(ssh->mainchan,
9753 bufsize < ssh->mainchan->v.v2.locmaxwin ?
9754 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
9755 if (ssh->cfg.ssh_simple)
9758 buflimit = ssh->mainchan->v.v2.locmaxwin;
9759 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
9760 ssh->mainchan->throttling_conn = 0;
9761 ssh_throttle_conn(ssh, -1);
9767 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
9769 struct ssh_channel *c = (struct ssh_channel *)channel;
9771 struct Packet *pktout;
9773 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
9775 if (ssh->version == 1) {
9776 send_packet(ssh, SSH1_MSG_PORT_OPEN,
9777 PKT_INT, c->localid,
9780 /* PKT_STR, <org:orgport>, */
9783 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
9784 ssh2_pkt_addstring(pktout, "direct-tcpip");
9785 ssh2_pkt_adduint32(pktout, c->localid);
9786 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
9787 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
9788 ssh2_pkt_addstring(pktout, hostname);
9789 ssh2_pkt_adduint32(pktout, port);
9791 * We make up values for the originator data; partly it's
9792 * too much hassle to keep track, and partly I'm not
9793 * convinced the server should be told details like that
9794 * about my local network configuration.
9795 * The "originator IP address" is syntactically a numeric
9796 * IP address, and some servers (e.g., Tectia) get upset
9797 * if it doesn't match this syntax.
9799 ssh2_pkt_addstring(pktout, "0.0.0.0");
9800 ssh2_pkt_adduint32(pktout, 0);
9801 ssh2_pkt_send(ssh, pktout);
9805 static int ssh_connected(void *handle)
9807 Ssh ssh = (Ssh) handle;
9808 return ssh->s != NULL;
9811 static int ssh_sendok(void *handle)
9813 Ssh ssh = (Ssh) handle;
9814 return ssh->send_ok;
9817 static int ssh_ldisc(void *handle, int option)
9819 Ssh ssh = (Ssh) handle;
9820 if (option == LD_ECHO)
9821 return ssh->echoing;
9822 if (option == LD_EDIT)
9823 return ssh->editing;
9827 static void ssh_provide_ldisc(void *handle, void *ldisc)
9829 Ssh ssh = (Ssh) handle;
9833 static void ssh_provide_logctx(void *handle, void *logctx)
9835 Ssh ssh = (Ssh) handle;
9836 ssh->logctx = logctx;
9839 static int ssh_return_exitcode(void *handle)
9841 Ssh ssh = (Ssh) handle;
9845 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
9849 * cfg_info for SSH is the currently running version of the
9850 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
9852 static int ssh_cfg_info(void *handle)
9854 Ssh ssh = (Ssh) handle;
9855 return ssh->version;
9859 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
9860 * that fails. This variable is the means by which scp.c can reach
9861 * into the SSH code and find out which one it got.
9863 extern int ssh_fallback_cmd(void *handle)
9865 Ssh ssh = (Ssh) handle;
9866 return ssh->fallback_cmd;
9869 Backend ssh_backend = {
9879 ssh_return_exitcode,