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 pfd_close(c->u.pfd.s);
2868 del234(ssh->channels, c); /* moving next one to index 0 */
2869 if (ssh->version == 2)
2870 bufchain_clear(&c->v.v2.outbuffer);
2875 * Go through port-forwardings, and close any associated
2876 * listening sockets.
2878 if (ssh->portfwds) {
2879 struct ssh_portfwd *pf;
2880 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2881 /* Dispose of any listening socket. */
2883 pfd_terminate(pf->local);
2884 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2887 freetree234(ssh->portfwds);
2888 ssh->portfwds = NULL;
2894 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2895 const char *error_msg, int error_code)
2897 Ssh ssh = (Ssh) plug;
2898 char addrbuf[256], *msg;
2900 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2903 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2905 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2911 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2914 Ssh ssh = (Ssh) plug;
2915 int need_notify = ssh_do_close(ssh, FALSE);
2918 if (!ssh->close_expected)
2919 error_msg = "Server unexpectedly closed network connection";
2921 error_msg = "Server closed network connection";
2924 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2928 notify_remote_exit(ssh->frontend);
2931 logevent(error_msg);
2932 if (!ssh->close_expected || !ssh->clean_exit)
2933 connection_fatal(ssh->frontend, "%s", error_msg);
2937 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2939 Ssh ssh = (Ssh) plug;
2940 ssh_gotdata(ssh, (unsigned char *)data, len);
2941 if (ssh->state == SSH_STATE_CLOSED) {
2942 ssh_do_close(ssh, TRUE);
2948 static void ssh_sent(Plug plug, int bufsize)
2950 Ssh ssh = (Ssh) plug;
2952 * If the send backlog on the SSH socket itself clears, we
2953 * should unthrottle the whole world if it was throttled.
2955 if (bufsize < SSH_MAX_BACKLOG)
2956 ssh_throttle_all(ssh, 0, bufsize);
2960 * Connect to specified host and port.
2961 * Returns an error message, or NULL on success.
2962 * Also places the canonical host name into `realhost'. It must be
2963 * freed by the caller.
2965 static const char *connect_to_host(Ssh ssh, char *host, int port,
2966 char **realhost, int nodelay, int keepalive)
2968 static const struct plug_function_table fn_table = {
2979 if (*ssh->cfg.loghost) {
2982 ssh->savedhost = dupstr(ssh->cfg.loghost);
2983 ssh->savedport = 22; /* default ssh port */
2986 * A colon suffix on savedhost also lets us affect
2989 * (FIXME: do something about IPv6 address literals here.)
2991 colon = strrchr(ssh->savedhost, ':');
2995 ssh->savedport = atoi(colon);
2998 ssh->savedhost = dupstr(host);
3000 port = 22; /* default ssh port */
3001 ssh->savedport = port;
3007 logeventf(ssh, "Looking up host \"%s\"%s", host,
3008 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3009 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3010 addr = name_lookup(host, port, realhost, &ssh->cfg,
3011 ssh->cfg.addressfamily);
3012 if ((err = sk_addr_error(addr)) != NULL) {
3016 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3021 ssh->fn = &fn_table;
3022 ssh->s = new_connection(addr, *realhost, port,
3023 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
3024 if ((err = sk_socket_error(ssh->s)) != NULL) {
3026 notify_remote_exit(ssh->frontend);
3031 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3032 * send the version string too.
3034 if (ssh->cfg.sshprot == 0)
3036 if (ssh->cfg.sshprot == 3) {
3038 ssh_send_verstring(ssh, NULL);
3042 * loghost, if configured, overrides realhost.
3044 if (*ssh->cfg.loghost) {
3046 *realhost = dupstr(ssh->cfg.loghost);
3053 * Throttle or unthrottle the SSH connection.
3055 static void ssh_throttle_conn(Ssh ssh, int adjust)
3057 int old_count = ssh->conn_throttle_count;
3058 ssh->conn_throttle_count += adjust;
3059 assert(ssh->conn_throttle_count >= 0);
3060 if (ssh->conn_throttle_count && !old_count) {
3061 ssh_set_frozen(ssh, 1);
3062 } else if (!ssh->conn_throttle_count && old_count) {
3063 ssh_set_frozen(ssh, 0);
3068 * Throttle or unthrottle _all_ local data streams (for when sends
3069 * on the SSH connection itself back up).
3071 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3074 struct ssh_channel *c;
3076 if (enable == ssh->throttled_all)
3078 ssh->throttled_all = enable;
3079 ssh->overall_bufsize = bufsize;
3082 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3084 case CHAN_MAINSESSION:
3086 * This is treated separately, outside the switch.
3090 x11_override_throttle(c->u.x11.s, enable);
3093 /* Agent channels require no buffer management. */
3096 pfd_override_throttle(c->u.pfd.s, enable);
3102 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3104 Ssh ssh = (Ssh) sshv;
3106 ssh->agent_response = reply;
3107 ssh->agent_response_len = replylen;
3109 if (ssh->version == 1)
3110 do_ssh1_login(ssh, NULL, -1, NULL);
3112 do_ssh2_authconn(ssh, NULL, -1, NULL);
3115 static void ssh_dialog_callback(void *sshv, int ret)
3117 Ssh ssh = (Ssh) sshv;
3119 ssh->user_response = ret;
3121 if (ssh->version == 1)
3122 do_ssh1_login(ssh, NULL, -1, NULL);
3124 do_ssh2_transport(ssh, NULL, -1, NULL);
3127 * This may have unfrozen the SSH connection, so do a
3130 ssh_process_queued_incoming_data(ssh);
3133 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3135 struct ssh_channel *c = (struct ssh_channel *)cv;
3137 void *sentreply = reply;
3140 /* Fake SSH_AGENT_FAILURE. */
3141 sentreply = "\0\0\0\1\5";
3144 if (ssh->version == 2) {
3145 ssh2_add_channel_data(c, sentreply, replylen);
3148 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3149 PKT_INT, c->remoteid,
3152 PKT_DATA, sentreply, replylen,
3161 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3162 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3163 * => log `wire_reason'.
3165 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3166 int code, int clean_exit)
3170 client_reason = wire_reason;
3172 error = dupprintf("Disconnected: %s", client_reason);
3174 error = dupstr("Disconnected");
3176 if (ssh->version == 1) {
3177 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3179 } else if (ssh->version == 2) {
3180 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3181 ssh2_pkt_adduint32(pktout, code);
3182 ssh2_pkt_addstring(pktout, wire_reason);
3183 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3184 ssh2_pkt_send_noqueue(ssh, pktout);
3187 ssh->close_expected = TRUE;
3188 ssh->clean_exit = clean_exit;
3189 ssh_closing((Plug)ssh, error, 0, 0);
3194 * Handle the key exchange and user authentication phases.
3196 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3197 struct Packet *pktin)
3200 unsigned char cookie[8], *ptr;
3201 struct RSAKey servkey, hostkey;
3202 struct MD5Context md5c;
3203 struct do_ssh1_login_state {
3205 unsigned char *rsabuf, *keystr1, *keystr2;
3206 unsigned long supported_ciphers_mask, supported_auths_mask;
3207 int tried_publickey, tried_agent;
3208 int tis_auth_refused, ccard_auth_refused;
3209 unsigned char session_id[16];
3212 void *publickey_blob;
3213 int publickey_bloblen;
3214 char *publickey_comment;
3215 int publickey_encrypted;
3216 prompts_t *cur_prompt;
3219 unsigned char request[5], *response, *p;
3229 crState(do_ssh1_login_state);
3231 crBegin(ssh->do_ssh1_login_crstate);
3236 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3237 bombout(("Public key packet not received"));
3241 logevent("Received public keys");
3243 ptr = ssh_pkt_getdata(pktin, 8);
3245 bombout(("SSH-1 public key packet stopped before random cookie"));
3248 memcpy(cookie, ptr, 8);
3250 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3251 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
3252 bombout(("Failed to read SSH-1 public keys from public key packet"));
3257 * Log the host key fingerprint.
3261 logevent("Host key fingerprint is:");
3262 strcpy(logmsg, " ");
3263 hostkey.comment = NULL;
3264 rsa_fingerprint(logmsg + strlen(logmsg),
3265 sizeof(logmsg) - strlen(logmsg), &hostkey);
3269 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3270 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3271 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3272 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3273 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3275 ssh->v1_local_protoflags =
3276 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3277 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3280 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3281 MD5Update(&md5c, s->keystr1, servkey.bytes);
3282 MD5Update(&md5c, cookie, 8);
3283 MD5Final(s->session_id, &md5c);
3285 for (i = 0; i < 32; i++)
3286 ssh->session_key[i] = random_byte();
3289 * Verify that the `bits' and `bytes' parameters match.
3291 if (hostkey.bits > hostkey.bytes * 8 ||
3292 servkey.bits > servkey.bytes * 8) {
3293 bombout(("SSH-1 public keys were badly formatted"));
3297 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
3299 s->rsabuf = snewn(s->len, unsigned char);
3302 * Verify the host key.
3306 * First format the key into a string.
3308 int len = rsastr_len(&hostkey);
3309 char fingerprint[100];
3310 char *keystr = snewn(len, char);
3311 rsastr_fmt(keystr, &hostkey);
3312 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3314 ssh_set_frozen(ssh, 1);
3315 s->dlgret = verify_ssh_host_key(ssh->frontend,
3316 ssh->savedhost, ssh->savedport,
3317 "rsa", keystr, fingerprint,
3318 ssh_dialog_callback, ssh);
3320 if (s->dlgret < 0) {
3324 bombout(("Unexpected data from server while waiting"
3325 " for user host key response"));
3328 } while (pktin || inlen > 0);
3329 s->dlgret = ssh->user_response;
3331 ssh_set_frozen(ssh, 0);
3333 if (s->dlgret == 0) {
3334 ssh_disconnect(ssh, "User aborted at host key verification",
3340 for (i = 0; i < 32; i++) {
3341 s->rsabuf[i] = ssh->session_key[i];
3343 s->rsabuf[i] ^= s->session_id[i];
3346 if (hostkey.bytes > servkey.bytes) {
3347 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3349 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3351 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3353 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3356 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3360 logevent("Encrypted session key");
3363 int cipher_chosen = 0, warn = 0;
3364 char *cipher_string = NULL;
3366 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3367 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3368 if (next_cipher == CIPHER_WARN) {
3369 /* If/when we choose a cipher, warn about it */
3371 } else if (next_cipher == CIPHER_AES) {
3372 /* XXX Probably don't need to mention this. */
3373 logevent("AES not supported in SSH-1, skipping");
3375 switch (next_cipher) {
3376 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3377 cipher_string = "3DES"; break;
3378 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3379 cipher_string = "Blowfish"; break;
3380 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3381 cipher_string = "single-DES"; break;
3383 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3387 if (!cipher_chosen) {
3388 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3389 bombout(("Server violates SSH-1 protocol by not "
3390 "supporting 3DES encryption"));
3392 /* shouldn't happen */
3393 bombout(("No supported ciphers found"));
3397 /* Warn about chosen cipher if necessary. */
3399 ssh_set_frozen(ssh, 1);
3400 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3401 ssh_dialog_callback, ssh);
3402 if (s->dlgret < 0) {
3406 bombout(("Unexpected data from server while waiting"
3407 " for user response"));
3410 } while (pktin || inlen > 0);
3411 s->dlgret = ssh->user_response;
3413 ssh_set_frozen(ssh, 0);
3414 if (s->dlgret == 0) {
3415 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3422 switch (s->cipher_type) {
3423 case SSH_CIPHER_3DES:
3424 logevent("Using 3DES encryption");
3426 case SSH_CIPHER_DES:
3427 logevent("Using single-DES encryption");
3429 case SSH_CIPHER_BLOWFISH:
3430 logevent("Using Blowfish encryption");
3434 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3435 PKT_CHAR, s->cipher_type,
3436 PKT_DATA, cookie, 8,
3437 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3438 PKT_DATA, s->rsabuf, s->len,
3439 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3441 logevent("Trying to enable encryption...");
3445 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3446 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3448 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3449 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3450 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3452 ssh->crcda_ctx = crcda_make_context();
3453 logevent("Installing CRC compensation attack detector");
3455 if (servkey.modulus) {
3456 sfree(servkey.modulus);
3457 servkey.modulus = NULL;
3459 if (servkey.exponent) {
3460 sfree(servkey.exponent);
3461 servkey.exponent = NULL;
3463 if (hostkey.modulus) {
3464 sfree(hostkey.modulus);
3465 hostkey.modulus = NULL;
3467 if (hostkey.exponent) {
3468 sfree(hostkey.exponent);
3469 hostkey.exponent = NULL;
3473 if (pktin->type != SSH1_SMSG_SUCCESS) {
3474 bombout(("Encryption not successfully enabled"));
3478 logevent("Successfully started encryption");
3480 fflush(stdout); /* FIXME eh? */
3482 if (!get_remote_username(&ssh->cfg, s->username,
3483 sizeof(s->username))) {
3484 int ret; /* need not be kept over crReturn */
3485 s->cur_prompt = new_prompts(ssh->frontend);
3486 s->cur_prompt->to_server = TRUE;
3487 s->cur_prompt->name = dupstr("SSH login name");
3488 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
3489 lenof(s->username));
3490 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3493 crWaitUntil(!pktin);
3494 ret = get_userpass_input(s->cur_prompt, in, inlen);
3499 * Failed to get a username. Terminate.
3501 free_prompts(s->cur_prompt);
3502 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3505 memcpy(s->username, s->cur_prompt->prompts[0]->result,
3506 lenof(s->username));
3507 free_prompts(s->cur_prompt);
3510 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3512 char *userlog = dupprintf("Sent username \"%s\"", s->username);
3514 if (flags & FLAG_INTERACTIVE &&
3515 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3516 c_write_str(ssh, userlog);
3517 c_write_str(ssh, "\r\n");
3525 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3526 /* We must not attempt PK auth. Pretend we've already tried it. */
3527 s->tried_publickey = s->tried_agent = 1;
3529 s->tried_publickey = s->tried_agent = 0;
3531 s->tis_auth_refused = s->ccard_auth_refused = 0;
3533 * Load the public half of any configured keyfile for later use.
3535 if (!filename_is_null(ssh->cfg.keyfile)) {
3537 logeventf(ssh, "Reading private key file \"%.150s\"",
3538 filename_to_str(&ssh->cfg.keyfile));
3539 keytype = key_type(&ssh->cfg.keyfile);
3540 if (keytype == SSH_KEYTYPE_SSH1) {
3542 if (rsakey_pubblob(&ssh->cfg.keyfile,
3543 &s->publickey_blob, &s->publickey_bloblen,
3544 &s->publickey_comment, &error)) {
3545 s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
3549 logeventf(ssh, "Unable to load private key (%s)", error);
3550 msgbuf = dupprintf("Unable to load private key file "
3551 "\"%.150s\" (%s)\r\n",
3552 filename_to_str(&ssh->cfg.keyfile),
3554 c_write_str(ssh, msgbuf);
3556 s->publickey_blob = NULL;
3560 logeventf(ssh, "Unable to use this key file (%s)",
3561 key_type_to_str(keytype));
3562 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3564 filename_to_str(&ssh->cfg.keyfile),
3565 key_type_to_str(keytype));
3566 c_write_str(ssh, msgbuf);
3568 s->publickey_blob = NULL;
3571 s->publickey_blob = NULL;
3573 while (pktin->type == SSH1_SMSG_FAILURE) {
3574 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3576 if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
3578 * Attempt RSA authentication using Pageant.
3584 logevent("Pageant is running. Requesting keys.");
3586 /* Request the keys held by the agent. */
3587 PUT_32BIT(s->request, 1);
3588 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3589 if (!agent_query(s->request, 5, &r, &s->responselen,
3590 ssh_agent_callback, ssh)) {
3594 bombout(("Unexpected data from server while waiting"
3595 " for agent response"));
3598 } while (pktin || inlen > 0);
3599 r = ssh->agent_response;
3600 s->responselen = ssh->agent_response_len;
3602 s->response = (unsigned char *) r;
3603 if (s->response && s->responselen >= 5 &&
3604 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3605 s->p = s->response + 5;
3606 s->nkeys = GET_32BIT(s->p);
3608 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3609 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3610 unsigned char *pkblob = s->p;
3614 do { /* do while (0) to make breaking easy */
3615 n = ssh1_read_bignum
3616 (s->p, s->responselen-(s->p-s->response),
3621 n = ssh1_read_bignum
3622 (s->p, s->responselen-(s->p-s->response),
3627 if (s->responselen - (s->p-s->response) < 4)
3629 s->commentlen = GET_32BIT(s->p);
3631 if (s->responselen - (s->p-s->response) <
3634 s->commentp = (char *)s->p;
3635 s->p += s->commentlen;
3639 logevent("Pageant key list packet was truncated");
3643 if (s->publickey_blob) {
3644 if (!memcmp(pkblob, s->publickey_blob,
3645 s->publickey_bloblen)) {
3646 logeventf(ssh, "Pageant key #%d matches "
3647 "configured key file", s->keyi);
3648 s->tried_publickey = 1;
3650 /* Skip non-configured key */
3653 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3654 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3655 PKT_BIGNUM, s->key.modulus, PKT_END);
3657 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3658 logevent("Key refused");
3661 logevent("Received RSA challenge");
3662 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3663 bombout(("Server's RSA challenge was badly formatted"));
3668 char *agentreq, *q, *ret;
3671 len = 1 + 4; /* message type, bit count */
3672 len += ssh1_bignum_length(s->key.exponent);
3673 len += ssh1_bignum_length(s->key.modulus);
3674 len += ssh1_bignum_length(s->challenge);
3675 len += 16; /* session id */
3676 len += 4; /* response format */
3677 agentreq = snewn(4 + len, char);
3678 PUT_32BIT(agentreq, len);
3680 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3681 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3683 q += ssh1_write_bignum(q, s->key.exponent);
3684 q += ssh1_write_bignum(q, s->key.modulus);
3685 q += ssh1_write_bignum(q, s->challenge);
3686 memcpy(q, s->session_id, 16);
3688 PUT_32BIT(q, 1); /* response format */
3689 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3690 ssh_agent_callback, ssh)) {
3695 bombout(("Unexpected data from server"
3696 " while waiting for agent"
3700 } while (pktin || inlen > 0);
3701 vret = ssh->agent_response;
3702 retlen = ssh->agent_response_len;
3707 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3708 logevent("Sending Pageant's response");
3709 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3710 PKT_DATA, ret + 5, 16,
3714 if (pktin->type == SSH1_SMSG_SUCCESS) {
3716 ("Pageant's response accepted");
3717 if (flags & FLAG_VERBOSE) {
3718 c_write_str(ssh, "Authenticated using"
3720 c_write(ssh, s->commentp,
3722 c_write_str(ssh, "\" from agent\r\n");
3727 ("Pageant's response not accepted");
3730 ("Pageant failed to answer challenge");
3734 logevent("No reply received from Pageant");
3737 freebn(s->key.exponent);
3738 freebn(s->key.modulus);
3739 freebn(s->challenge);
3744 if (s->publickey_blob && !s->tried_publickey)
3745 logevent("Configured key file not in Pageant");
3750 if (s->publickey_blob && !s->tried_publickey) {
3752 * Try public key authentication with the specified
3755 int got_passphrase; /* need not be kept over crReturn */
3756 if (flags & FLAG_VERBOSE)
3757 c_write_str(ssh, "Trying public key authentication.\r\n");
3758 logeventf(ssh, "Trying public key \"%s\"",
3759 filename_to_str(&ssh->cfg.keyfile));
3760 s->tried_publickey = 1;
3761 got_passphrase = FALSE;
3762 while (!got_passphrase) {
3764 * Get a passphrase, if necessary.
3766 char *passphrase = NULL; /* only written after crReturn */
3768 if (!s->publickey_encrypted) {
3769 if (flags & FLAG_VERBOSE)
3770 c_write_str(ssh, "No passphrase required.\r\n");
3773 int ret; /* need not be kept over crReturn */
3774 s->cur_prompt = new_prompts(ssh->frontend);
3775 s->cur_prompt->to_server = FALSE;
3776 s->cur_prompt->name = dupstr("SSH key passphrase");
3777 add_prompt(s->cur_prompt,
3778 dupprintf("Passphrase for key \"%.100s\": ",
3779 s->publickey_comment),
3780 FALSE, SSH_MAX_PASSWORD_LEN);
3781 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3784 crWaitUntil(!pktin);
3785 ret = get_userpass_input(s->cur_prompt, in, inlen);
3789 /* Failed to get a passphrase. Terminate. */
3790 free_prompts(s->cur_prompt);
3791 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3795 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3796 free_prompts(s->cur_prompt);
3799 * Try decrypting key with passphrase.
3801 ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
3804 memset(passphrase, 0, strlen(passphrase));
3808 /* Correct passphrase. */
3809 got_passphrase = TRUE;
3810 } else if (ret == 0) {
3811 c_write_str(ssh, "Couldn't load private key from ");
3812 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3813 c_write_str(ssh, " (");
3814 c_write_str(ssh, error);
3815 c_write_str(ssh, ").\r\n");
3816 got_passphrase = FALSE;
3817 break; /* go and try something else */
3818 } else if (ret == -1) {
3819 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3820 got_passphrase = FALSE;
3823 assert(0 && "unexpected return from loadrsakey()");
3824 got_passphrase = FALSE; /* placate optimisers */
3828 if (got_passphrase) {
3831 * Send a public key attempt.
3833 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3834 PKT_BIGNUM, s->key.modulus, PKT_END);
3837 if (pktin->type == SSH1_SMSG_FAILURE) {
3838 c_write_str(ssh, "Server refused our public key.\r\n");
3839 continue; /* go and try something else */
3841 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3842 bombout(("Bizarre response to offer of public key"));
3848 unsigned char buffer[32];
3849 Bignum challenge, response;
3851 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3852 bombout(("Server's RSA challenge was badly formatted"));
3855 response = rsadecrypt(challenge, &s->key);
3856 freebn(s->key.private_exponent);/* burn the evidence */
3858 for (i = 0; i < 32; i++) {
3859 buffer[i] = bignum_byte(response, 31 - i);
3863 MD5Update(&md5c, buffer, 32);
3864 MD5Update(&md5c, s->session_id, 16);
3865 MD5Final(buffer, &md5c);
3867 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3868 PKT_DATA, buffer, 16, PKT_END);
3875 if (pktin->type == SSH1_SMSG_FAILURE) {
3876 if (flags & FLAG_VERBOSE)
3877 c_write_str(ssh, "Failed to authenticate with"
3878 " our public key.\r\n");
3879 continue; /* go and try something else */
3880 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3881 bombout(("Bizarre response to RSA authentication response"));
3885 break; /* we're through! */
3891 * Otherwise, try various forms of password-like authentication.
3893 s->cur_prompt = new_prompts(ssh->frontend);
3895 if (ssh->cfg.try_tis_auth &&
3896 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3897 !s->tis_auth_refused) {
3898 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3899 logevent("Requested TIS authentication");
3900 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3902 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3903 logevent("TIS authentication declined");
3904 if (flags & FLAG_INTERACTIVE)
3905 c_write_str(ssh, "TIS authentication refused.\r\n");
3906 s->tis_auth_refused = 1;
3911 char *instr_suf, *prompt;
3913 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3915 bombout(("TIS challenge packet was badly formed"));
3918 logevent("Received TIS challenge");
3919 s->cur_prompt->to_server = TRUE;
3920 s->cur_prompt->name = dupstr("SSH TIS authentication");
3921 /* Prompt heuristic comes from OpenSSH */
3922 if (memchr(challenge, '\n', challengelen)) {
3923 instr_suf = dupstr("");
3924 prompt = dupprintf("%.*s", challengelen, challenge);
3926 instr_suf = dupprintf("%.*s", challengelen, challenge);
3927 prompt = dupstr("Response: ");
3929 s->cur_prompt->instruction =
3930 dupprintf("Using TIS authentication.%s%s",
3931 (*instr_suf) ? "\n" : "",
3933 s->cur_prompt->instr_reqd = TRUE;
3934 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3938 if (ssh->cfg.try_tis_auth &&
3939 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3940 !s->ccard_auth_refused) {
3941 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3942 logevent("Requested CryptoCard authentication");
3943 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3945 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3946 logevent("CryptoCard authentication declined");
3947 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3948 s->ccard_auth_refused = 1;
3953 char *instr_suf, *prompt;
3955 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3957 bombout(("CryptoCard challenge packet was badly formed"));
3960 logevent("Received CryptoCard challenge");
3961 s->cur_prompt->to_server = TRUE;
3962 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
3963 s->cur_prompt->name_reqd = FALSE;
3964 /* Prompt heuristic comes from OpenSSH */
3965 if (memchr(challenge, '\n', challengelen)) {
3966 instr_suf = dupstr("");
3967 prompt = dupprintf("%.*s", challengelen, challenge);
3969 instr_suf = dupprintf("%.*s", challengelen, challenge);
3970 prompt = dupstr("Response: ");
3972 s->cur_prompt->instruction =
3973 dupprintf("Using CryptoCard authentication.%s%s",
3974 (*instr_suf) ? "\n" : "",
3976 s->cur_prompt->instr_reqd = TRUE;
3977 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3981 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3982 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
3983 bombout(("No supported authentication methods available"));
3986 s->cur_prompt->to_server = TRUE;
3987 s->cur_prompt->name = dupstr("SSH password");
3988 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
3989 s->username, ssh->savedhost),
3990 FALSE, SSH_MAX_PASSWORD_LEN);
3994 * Show password prompt, having first obtained it via a TIS
3995 * or CryptoCard exchange if we're doing TIS or CryptoCard
3999 int ret; /* need not be kept over crReturn */
4000 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4003 crWaitUntil(!pktin);
4004 ret = get_userpass_input(s->cur_prompt, in, inlen);
4009 * Failed to get a password (for example
4010 * because one was supplied on the command line
4011 * which has already failed to work). Terminate.
4013 free_prompts(s->cur_prompt);
4014 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4019 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4021 * Defence against traffic analysis: we send a
4022 * whole bunch of packets containing strings of
4023 * different lengths. One of these strings is the
4024 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4025 * The others are all random data in
4026 * SSH1_MSG_IGNORE packets. This way a passive
4027 * listener can't tell which is the password, and
4028 * hence can't deduce the password length.
4030 * Anybody with a password length greater than 16
4031 * bytes is going to have enough entropy in their
4032 * password that a listener won't find it _that_
4033 * much help to know how long it is. So what we'll
4036 * - if password length < 16, we send 15 packets
4037 * containing string lengths 1 through 15
4039 * - otherwise, we let N be the nearest multiple
4040 * of 8 below the password length, and send 8
4041 * packets containing string lengths N through
4042 * N+7. This won't obscure the order of
4043 * magnitude of the password length, but it will
4044 * introduce a bit of extra uncertainty.
4046 * A few servers can't deal with SSH1_MSG_IGNORE, at
4047 * least in this context. For these servers, we need
4048 * an alternative defence. We make use of the fact
4049 * that the password is interpreted as a C string:
4050 * so we can append a NUL, then some random data.
4052 * A few servers can deal with neither SSH1_MSG_IGNORE
4053 * here _nor_ a padded password string.
4054 * For these servers we are left with no defences
4055 * against password length sniffing.
4057 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4058 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4060 * The server can deal with SSH1_MSG_IGNORE, so
4061 * we can use the primary defence.
4063 int bottom, top, pwlen, i;
4066 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4068 bottom = 0; /* zero length passwords are OK! :-) */
4071 bottom = pwlen & ~7;
4075 assert(pwlen >= bottom && pwlen <= top);
4077 randomstr = snewn(top + 1, char);
4079 for (i = bottom; i <= top; i++) {
4081 defer_packet(ssh, s->pwpkt_type,
4082 PKTT_PASSWORD, PKT_STR,
4083 s->cur_prompt->prompts[0]->result,
4084 PKTT_OTHER, PKT_END);
4086 for (j = 0; j < i; j++) {
4088 randomstr[j] = random_byte();
4089 } while (randomstr[j] == '\0');
4091 randomstr[i] = '\0';
4092 defer_packet(ssh, SSH1_MSG_IGNORE,
4093 PKT_STR, randomstr, PKT_END);
4096 logevent("Sending password with camouflage packets");
4097 ssh_pkt_defersend(ssh);
4100 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4102 * The server can't deal with SSH1_MSG_IGNORE
4103 * but can deal with padded passwords, so we
4104 * can use the secondary defence.
4110 len = strlen(s->cur_prompt->prompts[0]->result);
4111 if (len < sizeof(string)) {
4113 strcpy(string, s->cur_prompt->prompts[0]->result);
4114 len++; /* cover the zero byte */
4115 while (len < sizeof(string)) {
4116 string[len++] = (char) random_byte();
4119 ss = s->cur_prompt->prompts[0]->result;
4121 logevent("Sending length-padded password");
4122 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4123 PKT_INT, len, PKT_DATA, ss, len,
4124 PKTT_OTHER, PKT_END);
4127 * The server is believed unable to cope with
4128 * any of our password camouflage methods.
4131 len = strlen(s->cur_prompt->prompts[0]->result);
4132 logevent("Sending unpadded password");
4133 send_packet(ssh, s->pwpkt_type,
4134 PKTT_PASSWORD, PKT_INT, len,
4135 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4136 PKTT_OTHER, PKT_END);
4139 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4140 PKT_STR, s->cur_prompt->prompts[0]->result,
4141 PKTT_OTHER, PKT_END);
4143 logevent("Sent password");
4144 free_prompts(s->cur_prompt);
4146 if (pktin->type == SSH1_SMSG_FAILURE) {
4147 if (flags & FLAG_VERBOSE)
4148 c_write_str(ssh, "Access denied\r\n");
4149 logevent("Authentication refused");
4150 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4151 bombout(("Strange packet received, type %d", pktin->type));
4157 if (s->publickey_blob) {
4158 sfree(s->publickey_blob);
4159 sfree(s->publickey_comment);
4162 logevent("Authentication successful");
4167 void sshfwd_close(struct ssh_channel *c)
4171 if (ssh->state == SSH_STATE_CLOSED)
4176 * If halfopen is true, we have sent
4177 * CHANNEL_OPEN for this channel, but it hasn't even been
4178 * acknowledged by the server. So we must set a close flag
4179 * on it now, and then when the server acks the channel
4180 * open, we can close it then.
4183 if (ssh->version == 1) {
4184 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4186 c->closes = 1; /* sent MSG_CLOSE */
4188 int bytes_to_send = bufchain_size(&c->v.v2.outbuffer);
4189 if (bytes_to_send > 0) {
4191 * If we still have unsent data in our outgoing
4192 * buffer for this channel, we can't actually
4193 * initiate a close operation yet or that data
4194 * will be lost. Instead, set the pending_close
4195 * flag so that when we do clear the buffer
4196 * we'll start closing the channel.
4198 char logmsg[160] = {'\0'};
4201 "Forwarded port pending to be closed : "
4202 "%d bytes remaining",
4206 c->pending_close = TRUE;
4209 * No locally buffered data, so we can send the
4210 * close message immediately.
4212 struct Packet *pktout;
4213 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4214 ssh2_pkt_adduint32(pktout, c->remoteid);
4215 ssh2_pkt_send(ssh, pktout);
4216 c->closes = 1; /* sent MSG_CLOSE */
4217 logevent("Nothing left to send, closing channel");
4222 if (c->type == CHAN_X11) {
4224 logevent("Forwarded X11 connection terminated");
4225 } else if (c->type == CHAN_SOCKDATA ||
4226 c->type == CHAN_SOCKDATA_DORMANT) {
4228 logevent("Forwarded port closed");
4233 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4237 if (ssh->state == SSH_STATE_CLOSED)
4240 if (ssh->version == 1) {
4241 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4242 PKT_INT, c->remoteid,
4243 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
4244 PKTT_OTHER, PKT_END);
4246 * In SSH-1 we can return 0 here - implying that forwarded
4247 * connections are never individually throttled - because
4248 * the only circumstance that can cause throttling will be
4249 * the whole SSH connection backing up, in which case
4250 * _everything_ will be throttled as a whole.
4254 ssh2_add_channel_data(c, buf, len);
4255 return ssh2_try_send(c);
4259 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4264 if (ssh->state == SSH_STATE_CLOSED)
4267 if (ssh->version == 1) {
4268 buflimit = SSH1_BUFFER_LIMIT;
4270 buflimit = c->v.v2.locmaxwin;
4271 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4273 if (c->throttling_conn && bufsize <= buflimit) {
4274 c->throttling_conn = 0;
4275 ssh_throttle_conn(ssh, -1);
4279 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4281 struct queued_handler *qh = ssh->qhead;
4285 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4288 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4289 ssh->packet_dispatch[qh->msg1] = NULL;
4292 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4293 ssh->packet_dispatch[qh->msg2] = NULL;
4297 ssh->qhead = qh->next;
4299 if (ssh->qhead->msg1 > 0) {
4300 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4301 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4303 if (ssh->qhead->msg2 > 0) {
4304 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4305 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4308 ssh->qhead = ssh->qtail = NULL;
4309 ssh->packet_dispatch[pktin->type] = NULL;
4312 qh->handler(ssh, pktin, qh->ctx);
4317 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4318 chandler_fn_t handler, void *ctx)
4320 struct queued_handler *qh;
4322 qh = snew(struct queued_handler);
4325 qh->handler = handler;
4329 if (ssh->qtail == NULL) {
4333 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4334 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4337 assert(ssh->packet_dispatch[qh->msg2] == NULL);
4338 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4341 ssh->qtail->next = qh;
4346 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4348 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4350 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4351 SSH2_MSG_REQUEST_SUCCESS)) {
4352 logeventf(ssh, "Remote port forwarding from %s enabled",
4355 logeventf(ssh, "Remote port forwarding from %s refused",
4358 rpf = del234(ssh->rportfwds, pf);
4360 pf->pfrec->remote = NULL;
4365 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
4367 const char *portfwd_strptr = cfg->portfwd;
4368 struct ssh_portfwd *epf;
4371 if (!ssh->portfwds) {
4372 ssh->portfwds = newtree234(ssh_portcmp);
4375 * Go through the existing port forwardings and tag them
4376 * with status==DESTROY. Any that we want to keep will be
4377 * re-enabled (status==KEEP) as we go through the
4378 * configuration and find out which bits are the same as
4381 struct ssh_portfwd *epf;
4383 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4384 epf->status = DESTROY;
4387 while (*portfwd_strptr) {
4388 char address_family, type;
4389 int sport,dport,sserv,dserv;
4390 char sports[256], dports[256], saddr[256], host[256];
4393 address_family = 'A';
4395 if (*portfwd_strptr == 'A' ||
4396 *portfwd_strptr == '4' ||
4397 *portfwd_strptr == '6')
4398 address_family = *portfwd_strptr++;
4399 if (*portfwd_strptr == 'L' ||
4400 *portfwd_strptr == 'R' ||
4401 *portfwd_strptr == 'D')
4402 type = *portfwd_strptr++;
4407 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4408 if (*portfwd_strptr == ':') {
4410 * We've seen a colon in the middle of the
4411 * source port number. This means that
4412 * everything we've seen until now is the
4413 * source _address_, so we'll move it into
4414 * saddr and start sports from the beginning
4419 if (ssh->version == 1 && type == 'R') {
4420 logeventf(ssh, "SSH-1 cannot handle remote source address "
4421 "spec \"%s\"; ignoring", sports);
4423 strcpy(saddr, sports);
4426 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4430 if (*portfwd_strptr == '\t')
4433 while (*portfwd_strptr && *portfwd_strptr != ':') {
4434 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4437 if (*portfwd_strptr == ':')
4440 while (*portfwd_strptr) {
4441 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4445 dport = atoi(dports);
4449 dport = net_service_lookup(dports);
4451 logeventf(ssh, "Service lookup failed for destination"
4452 " port \"%s\"", dports);
4456 while (*portfwd_strptr) portfwd_strptr++;
4460 portfwd_strptr++; /* eat the NUL and move to next one */
4462 sport = atoi(sports);
4466 sport = net_service_lookup(sports);
4468 logeventf(ssh, "Service lookup failed for source"
4469 " port \"%s\"", sports);
4472 if (sport && dport) {
4473 /* Set up a description of the source port. */
4474 struct ssh_portfwd *pfrec, *epfrec;
4476 pfrec = snew(struct ssh_portfwd);
4478 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4479 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4480 pfrec->sport = sport;
4481 pfrec->daddr = *host ? dupstr(host) : NULL;
4482 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4483 pfrec->dport = dport;
4484 pfrec->local = NULL;
4485 pfrec->remote = NULL;
4486 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4487 address_family == '6' ? ADDRTYPE_IPV6 :
4490 epfrec = add234(ssh->portfwds, pfrec);
4491 if (epfrec != pfrec) {
4492 if (epfrec->status == DESTROY) {
4494 * We already have a port forwarding up and running
4495 * with precisely these parameters. Hence, no need
4496 * to do anything; simply re-tag the existing one
4499 epfrec->status = KEEP;
4502 * Anything else indicates that there was a duplicate
4503 * in our input, which we'll silently ignore.
4505 free_portfwd(pfrec);
4507 pfrec->status = CREATE;
4513 * Now go through and destroy any port forwardings which were
4516 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4517 if (epf->status == DESTROY) {
4520 message = dupprintf("%s port forwarding from %s%s%d",
4521 epf->type == 'L' ? "local" :
4522 epf->type == 'R' ? "remote" : "dynamic",
4523 epf->saddr ? epf->saddr : "",
4524 epf->saddr ? ":" : "",
4527 if (epf->type != 'D') {
4528 char *msg2 = dupprintf("%s to %s:%d", message,
4529 epf->daddr, epf->dport);
4534 logeventf(ssh, "Cancelling %s", message);
4537 /* epf->remote or epf->local may be NULL if setting up a
4538 * forwarding failed. */
4540 struct ssh_rportfwd *rpf = epf->remote;
4541 struct Packet *pktout;
4544 * Cancel the port forwarding at the server
4547 if (ssh->version == 1) {
4549 * We cannot cancel listening ports on the
4550 * server side in SSH-1! There's no message
4551 * to support it. Instead, we simply remove
4552 * the rportfwd record from the local end
4553 * so that any connections the server tries
4554 * to make on it are rejected.
4557 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4558 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4559 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4561 ssh2_pkt_addstring(pktout, epf->saddr);
4562 } else if (ssh->cfg.rport_acceptall) {
4563 /* XXX: ssh->cfg.rport_acceptall may not represent
4564 * what was used to open the original connection,
4565 * since it's reconfigurable. */
4566 ssh2_pkt_addstring(pktout, "0.0.0.0");
4568 ssh2_pkt_addstring(pktout, "127.0.0.1");
4570 ssh2_pkt_adduint32(pktout, epf->sport);
4571 ssh2_pkt_send(ssh, pktout);
4574 del234(ssh->rportfwds, rpf);
4576 } else if (epf->local) {
4577 pfd_terminate(epf->local);
4580 delpos234(ssh->portfwds, i);
4582 i--; /* so we don't skip one in the list */
4586 * And finally, set up any new port forwardings (status==CREATE).
4588 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4589 if (epf->status == CREATE) {
4590 char *sportdesc, *dportdesc;
4591 sportdesc = dupprintf("%s%s%s%s%d%s",
4592 epf->saddr ? epf->saddr : "",
4593 epf->saddr ? ":" : "",
4594 epf->sserv ? epf->sserv : "",
4595 epf->sserv ? "(" : "",
4597 epf->sserv ? ")" : "");
4598 if (epf->type == 'D') {
4601 dportdesc = dupprintf("%s:%s%s%d%s",
4603 epf->dserv ? epf->dserv : "",
4604 epf->dserv ? "(" : "",
4606 epf->dserv ? ")" : "");
4609 if (epf->type == 'L') {
4610 const char *err = pfd_addforward(epf->daddr, epf->dport,
4611 epf->saddr, epf->sport,
4614 epf->addressfamily);
4616 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4617 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4618 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4619 sportdesc, dportdesc,
4620 err ? " failed: " : "", err ? err : "");
4621 } else if (epf->type == 'D') {
4622 const char *err = pfd_addforward(NULL, -1,
4623 epf->saddr, epf->sport,
4626 epf->addressfamily);
4628 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4629 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4630 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4632 err ? " failed: " : "", err ? err : "");
4634 struct ssh_rportfwd *pf;
4637 * Ensure the remote port forwardings tree exists.
4639 if (!ssh->rportfwds) {
4640 if (ssh->version == 1)
4641 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4643 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4646 pf = snew(struct ssh_rportfwd);
4647 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4648 pf->dhost[lenof(pf->dhost)-1] = '\0';
4649 pf->dport = epf->dport;
4650 pf->sport = epf->sport;
4651 if (add234(ssh->rportfwds, pf) != pf) {
4652 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4653 epf->daddr, epf->dport);
4656 logeventf(ssh, "Requesting remote port %s"
4657 " forward to %s", sportdesc, dportdesc);
4659 pf->sportdesc = sportdesc;
4664 if (ssh->version == 1) {
4665 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4666 PKT_INT, epf->sport,
4667 PKT_STR, epf->daddr,
4668 PKT_INT, epf->dport,
4670 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4672 ssh_rportfwd_succfail, pf);
4674 struct Packet *pktout;
4675 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4676 ssh2_pkt_addstring(pktout, "tcpip-forward");
4677 ssh2_pkt_addbool(pktout, 1);/* want reply */
4679 ssh2_pkt_addstring(pktout, epf->saddr);
4680 } else if (cfg->rport_acceptall) {
4681 ssh2_pkt_addstring(pktout, "0.0.0.0");
4683 ssh2_pkt_addstring(pktout, "127.0.0.1");
4685 ssh2_pkt_adduint32(pktout, epf->sport);
4686 ssh2_pkt_send(ssh, pktout);
4688 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4689 SSH2_MSG_REQUEST_FAILURE,
4690 ssh_rportfwd_succfail, pf);
4699 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4702 int stringlen, bufsize;
4704 ssh_pkt_getstring(pktin, &string, &stringlen);
4705 if (string == NULL) {
4706 bombout(("Incoming terminal data packet was badly formed"));
4710 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4712 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4713 ssh->v1_stdout_throttling = 1;
4714 ssh_throttle_conn(ssh, +1);
4718 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4720 /* Remote side is trying to open a channel to talk to our
4721 * X-Server. Give them back a local channel number. */
4722 struct ssh_channel *c;
4723 int remoteid = ssh_pkt_getuint32(pktin);
4725 logevent("Received X11 connect request");
4726 /* Refuse if X11 forwarding is disabled. */
4727 if (!ssh->X11_fwd_enabled) {
4728 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4729 PKT_INT, remoteid, PKT_END);
4730 logevent("Rejected X11 connect request");
4732 c = snew(struct ssh_channel);
4735 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4736 NULL, -1, &ssh->cfg) != NULL) {
4737 logevent("Opening X11 forward connection failed");
4739 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4740 PKT_INT, remoteid, PKT_END);
4743 ("Opening X11 forward connection succeeded");
4744 c->remoteid = remoteid;
4745 c->halfopen = FALSE;
4746 c->localid = alloc_channel_id(ssh);
4748 c->pending_close = FALSE;
4749 c->throttling_conn = 0;
4750 c->type = CHAN_X11; /* identify channel type */
4751 add234(ssh->channels, c);
4752 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4753 PKT_INT, c->remoteid, PKT_INT,
4754 c->localid, PKT_END);
4755 logevent("Opened X11 forward channel");
4760 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4762 /* Remote side is trying to open a channel to talk to our
4763 * agent. Give them back a local channel number. */
4764 struct ssh_channel *c;
4765 int remoteid = ssh_pkt_getuint32(pktin);
4767 /* Refuse if agent forwarding is disabled. */
4768 if (!ssh->agentfwd_enabled) {
4769 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4770 PKT_INT, remoteid, PKT_END);
4772 c = snew(struct ssh_channel);
4774 c->remoteid = remoteid;
4775 c->halfopen = FALSE;
4776 c->localid = alloc_channel_id(ssh);
4778 c->pending_close = FALSE;
4779 c->throttling_conn = 0;
4780 c->type = CHAN_AGENT; /* identify channel type */
4781 c->u.a.lensofar = 0;
4782 add234(ssh->channels, c);
4783 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4784 PKT_INT, c->remoteid, PKT_INT, c->localid,
4789 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4791 /* Remote side is trying to open a channel to talk to a
4792 * forwarded port. Give them back a local channel number. */
4793 struct ssh_channel *c;
4794 struct ssh_rportfwd pf, *pfp;
4799 c = snew(struct ssh_channel);
4802 remoteid = ssh_pkt_getuint32(pktin);
4803 ssh_pkt_getstring(pktin, &host, &hostsize);
4804 port = ssh_pkt_getuint32(pktin);
4806 if (hostsize >= lenof(pf.dhost))
4807 hostsize = lenof(pf.dhost)-1;
4808 memcpy(pf.dhost, host, hostsize);
4809 pf.dhost[hostsize] = '\0';
4811 pfp = find234(ssh->rportfwds, &pf, NULL);
4814 logeventf(ssh, "Rejected remote port open request for %s:%d",
4816 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4817 PKT_INT, remoteid, PKT_END);
4819 logeventf(ssh, "Received remote port open request for %s:%d",
4821 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4822 c, &ssh->cfg, pfp->pfrec->addressfamily);
4824 logeventf(ssh, "Port open failed: %s", e);
4826 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4827 PKT_INT, remoteid, PKT_END);
4829 c->remoteid = remoteid;
4830 c->halfopen = FALSE;
4831 c->localid = alloc_channel_id(ssh);
4833 c->pending_close = FALSE;
4834 c->throttling_conn = 0;
4835 c->type = CHAN_SOCKDATA; /* identify channel type */
4836 add234(ssh->channels, c);
4837 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4838 PKT_INT, c->remoteid, PKT_INT,
4839 c->localid, PKT_END);
4840 logevent("Forwarded port opened successfully");
4845 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4847 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4848 unsigned int localid = ssh_pkt_getuint32(pktin);
4849 struct ssh_channel *c;
4851 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4852 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4853 c->remoteid = localid;
4854 c->halfopen = FALSE;
4855 c->type = CHAN_SOCKDATA;
4856 c->throttling_conn = 0;
4857 pfd_confirm(c->u.pfd.s);
4860 if (c && c->closes) {
4862 * We have a pending close on this channel,
4863 * which we decided on before the server acked
4864 * the channel open. So now we know the
4865 * remoteid, we can close it again.
4867 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4868 PKT_INT, c->remoteid, PKT_END);
4872 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4874 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4875 struct ssh_channel *c;
4877 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4878 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4879 logevent("Forwarded connection refused by server");
4880 pfd_close(c->u.pfd.s);
4881 del234(ssh->channels, c);
4886 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4888 /* Remote side closes a channel. */
4889 unsigned i = ssh_pkt_getuint32(pktin);
4890 struct ssh_channel *c;
4891 c = find234(ssh->channels, &i, ssh_channelfind);
4892 if (c && !c->halfopen) {
4895 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4897 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4898 logevent("Forwarded X11 connection terminated");
4899 assert(c->u.x11.s != NULL);
4900 x11_close(c->u.x11.s);
4903 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4904 logevent("Forwarded port closed");
4905 assert(c->u.pfd.s != NULL);
4906 pfd_close(c->u.pfd.s);
4910 c->closes |= (closetype << 2); /* seen this message */
4911 if (!(c->closes & closetype)) {
4912 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4914 c->closes |= closetype; /* sent it too */
4917 if (c->closes == 15) {
4918 del234(ssh->channels, c);
4922 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4923 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4924 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4929 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4931 /* Data sent down one of our channels. */
4932 int i = ssh_pkt_getuint32(pktin);
4935 struct ssh_channel *c;
4937 ssh_pkt_getstring(pktin, &p, &len);
4939 c = find234(ssh->channels, &i, ssh_channelfind);
4944 bufsize = x11_send(c->u.x11.s, p, len);
4947 bufsize = pfd_send(c->u.pfd.s, p, len);
4950 /* Data for an agent message. Buffer it. */
4952 if (c->u.a.lensofar < 4) {
4953 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
4954 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4958 c->u.a.lensofar += l;
4960 if (c->u.a.lensofar == 4) {
4962 4 + GET_32BIT(c->u.a.msglen);
4963 c->u.a.message = snewn(c->u.a.totallen,
4965 memcpy(c->u.a.message, c->u.a.msglen, 4);
4967 if (c->u.a.lensofar >= 4 && len > 0) {
4969 min(c->u.a.totallen - c->u.a.lensofar,
4971 memcpy(c->u.a.message + c->u.a.lensofar, p,
4975 c->u.a.lensofar += l;
4977 if (c->u.a.lensofar == c->u.a.totallen) {
4980 if (agent_query(c->u.a.message,
4983 ssh_agentf_callback, c))
4984 ssh_agentf_callback(c, reply, replylen);
4985 sfree(c->u.a.message);
4986 c->u.a.lensofar = 0;
4989 bufsize = 0; /* agent channels never back up */
4992 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
4993 c->throttling_conn = 1;
4994 ssh_throttle_conn(ssh, +1);
4999 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5001 ssh->exitcode = ssh_pkt_getuint32(pktin);
5002 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5003 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5005 * In case `helpful' firewalls or proxies tack
5006 * extra human-readable text on the end of the
5007 * session which we might mistake for another
5008 * encrypted packet, we close the session once
5009 * we've sent EXIT_CONFIRMATION.
5011 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5014 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5015 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5017 struct Packet *pktout = (struct Packet *)data;
5019 unsigned int arg = 0;
5020 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5021 if (i == lenof(ssh_ttymodes)) return;
5022 switch (ssh_ttymodes[i].type) {
5024 arg = ssh_tty_parse_specchar(val);
5027 arg = ssh_tty_parse_boolean(val);
5030 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5031 ssh2_pkt_addbyte(pktout, arg);
5035 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5036 struct Packet *pktin)
5038 crBegin(ssh->do_ssh1_connection_crstate);
5040 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5041 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5042 ssh1_smsg_stdout_stderr_data;
5044 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5045 ssh1_msg_channel_open_confirmation;
5046 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5047 ssh1_msg_channel_open_failure;
5048 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5049 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5050 ssh1_msg_channel_close;
5051 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5052 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5054 if (ssh->cfg.agentfwd && agent_exists()) {
5055 logevent("Requesting agent forwarding");
5056 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5060 if (pktin->type != SSH1_SMSG_SUCCESS
5061 && pktin->type != SSH1_SMSG_FAILURE) {
5062 bombout(("Protocol confusion"));
5064 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5065 logevent("Agent forwarding refused");
5067 logevent("Agent forwarding enabled");
5068 ssh->agentfwd_enabled = TRUE;
5069 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5073 if (ssh->cfg.x11_forward &&
5074 (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
5075 ssh->cfg.x11_auth, &ssh->cfg))) {
5076 logevent("Requesting X11 forwarding");
5078 * Note that while we blank the X authentication data here, we don't
5079 * take any special action to blank the start of an X11 channel,
5080 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5081 * without having session blanking enabled is likely to leak your
5082 * cookie into the log.
5084 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5085 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5086 PKT_STR, ssh->x11disp->remoteauthprotoname,
5088 PKT_STR, ssh->x11disp->remoteauthdatastring,
5090 PKT_INT, ssh->x11disp->screennum,
5093 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5094 PKT_STR, ssh->x11disp->remoteauthprotoname,
5096 PKT_STR, ssh->x11disp->remoteauthdatastring,
5103 if (pktin->type != SSH1_SMSG_SUCCESS
5104 && pktin->type != SSH1_SMSG_FAILURE) {
5105 bombout(("Protocol confusion"));
5107 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5108 logevent("X11 forwarding refused");
5110 logevent("X11 forwarding enabled");
5111 ssh->X11_fwd_enabled = TRUE;
5112 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5116 ssh_setup_portfwd(ssh, &ssh->cfg);
5117 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5119 if (!ssh->cfg.nopty) {
5121 /* Unpick the terminal-speed string. */
5122 /* XXX perhaps we should allow no speeds to be sent. */
5123 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5124 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
5125 /* Send the pty request. */
5126 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5127 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
5128 ssh_pkt_adduint32(pkt, ssh->term_height);
5129 ssh_pkt_adduint32(pkt, ssh->term_width);
5130 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5131 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5132 parse_ttymodes(ssh, ssh->cfg.ttymodes,
5133 ssh1_send_ttymode, (void *)pkt);
5134 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5135 ssh_pkt_adduint32(pkt, ssh->ispeed);
5136 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5137 ssh_pkt_adduint32(pkt, ssh->ospeed);
5138 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5140 ssh->state = SSH_STATE_INTERMED;
5144 if (pktin->type != SSH1_SMSG_SUCCESS
5145 && pktin->type != SSH1_SMSG_FAILURE) {
5146 bombout(("Protocol confusion"));
5148 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5149 c_write_str(ssh, "Server refused to allocate pty\r\n");
5150 ssh->editing = ssh->echoing = 1;
5152 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5153 ssh->ospeed, ssh->ispeed);
5155 ssh->editing = ssh->echoing = 1;
5158 if (ssh->cfg.compression) {
5159 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5163 if (pktin->type != SSH1_SMSG_SUCCESS
5164 && pktin->type != SSH1_SMSG_FAILURE) {
5165 bombout(("Protocol confusion"));
5167 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5168 c_write_str(ssh, "Server refused to compress\r\n");
5170 logevent("Started compression");
5171 ssh->v1_compressing = TRUE;
5172 ssh->cs_comp_ctx = zlib_compress_init();
5173 logevent("Initialised zlib (RFC1950) compression");
5174 ssh->sc_comp_ctx = zlib_decompress_init();
5175 logevent("Initialised zlib (RFC1950) decompression");
5179 * Start the shell or command.
5181 * Special case: if the first-choice command is an SSH-2
5182 * subsystem (hence not usable here) and the second choice
5183 * exists, we fall straight back to that.
5186 char *cmd = ssh->cfg.remote_cmd_ptr;
5188 if (!cmd) cmd = ssh->cfg.remote_cmd;
5190 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
5191 cmd = ssh->cfg.remote_cmd_ptr2;
5192 ssh->fallback_cmd = TRUE;
5195 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5197 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5198 logevent("Started session");
5201 ssh->state = SSH_STATE_SESSION;
5202 if (ssh->size_needed)
5203 ssh_size(ssh, ssh->term_width, ssh->term_height);
5204 if (ssh->eof_needed)
5205 ssh_special(ssh, TS_EOF);
5208 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5210 ssh->channels = newtree234(ssh_channelcmp);
5214 * By this point, most incoming packets are already being
5215 * handled by the dispatch table, and we need only pay
5216 * attention to the unusual ones.
5221 if (pktin->type == SSH1_SMSG_SUCCESS) {
5222 /* may be from EXEC_SHELL on some servers */
5223 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5224 /* may be from EXEC_SHELL on some servers
5225 * if no pty is available or in other odd cases. Ignore */
5227 bombout(("Strange packet received: type %d", pktin->type));
5232 int len = min(inlen, 512);
5233 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5234 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
5235 PKTT_OTHER, PKT_END);
5246 * Handle the top-level SSH-2 protocol.
5248 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5253 ssh_pkt_getstring(pktin, &msg, &msglen);
5254 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5257 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5259 /* log reason code in disconnect message */
5263 ssh_pkt_getstring(pktin, &msg, &msglen);
5264 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5267 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5269 /* Do nothing, because we're ignoring it! Duhh. */
5272 static void ssh1_protocol_setup(Ssh ssh)
5277 * Most messages are handled by the coroutines.
5279 for (i = 0; i < 256; i++)
5280 ssh->packet_dispatch[i] = NULL;
5283 * These special message types we install handlers for.
5285 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5286 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5287 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5290 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5291 struct Packet *pktin)
5293 unsigned char *in=(unsigned char*)vin;
5294 if (ssh->state == SSH_STATE_CLOSED)
5297 if (pktin && ssh->packet_dispatch[pktin->type]) {
5298 ssh->packet_dispatch[pktin->type](ssh, pktin);
5302 if (!ssh->protocol_initial_phase_done) {
5303 if (do_ssh1_login(ssh, in, inlen, pktin))
5304 ssh->protocol_initial_phase_done = TRUE;
5309 do_ssh1_connection(ssh, in, inlen, pktin);
5313 * Utility routine for decoding comma-separated strings in KEXINIT.
5315 static int in_commasep_string(char *needle, char *haystack, int haylen)
5318 if (!needle || !haystack) /* protect against null pointers */
5320 needlen = strlen(needle);
5323 * Is it at the start of the string?
5325 if (haylen >= needlen && /* haystack is long enough */
5326 !memcmp(needle, haystack, needlen) && /* initial match */
5327 (haylen == needlen || haystack[needlen] == ',')
5328 /* either , or EOS follows */
5332 * If not, search for the next comma and resume after that.
5333 * If no comma found, terminate.
5335 while (haylen > 0 && *haystack != ',')
5336 haylen--, haystack++;
5339 haylen--, haystack++; /* skip over comma itself */
5344 * Similar routine for checking whether we have the first string in a list.
5346 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5349 if (!needle || !haystack) /* protect against null pointers */
5351 needlen = strlen(needle);
5353 * Is it at the start of the string?
5355 if (haylen >= needlen && /* haystack is long enough */
5356 !memcmp(needle, haystack, needlen) && /* initial match */
5357 (haylen == needlen || haystack[needlen] == ',')
5358 /* either , or EOS follows */
5366 * SSH-2 key creation method.
5367 * (Currently assumes 2 lots of any hash are sufficient to generate
5368 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5370 #define SSH2_MKKEY_ITERS (2)
5371 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5372 unsigned char *keyspace)
5374 const struct ssh_hash *h = ssh->kex->hash;
5376 /* First hlen bytes. */
5378 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5379 hash_mpint(h, s, K);
5380 h->bytes(s, H, h->hlen);
5381 h->bytes(s, &chr, 1);
5382 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5383 h->final(s, keyspace);
5384 /* Next hlen bytes. */
5386 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5387 hash_mpint(h, s, K);
5388 h->bytes(s, H, h->hlen);
5389 h->bytes(s, keyspace, h->hlen);
5390 h->final(s, keyspace + h->hlen);
5394 * Handle the SSH-2 transport layer.
5396 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5397 struct Packet *pktin)
5399 unsigned char *in = (unsigned char *)vin;
5400 struct do_ssh2_transport_state {
5401 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5402 Bignum p, g, e, f, K;
5405 int kex_init_value, kex_reply_value;
5406 const struct ssh_mac **maclist;
5408 const struct ssh2_cipher *cscipher_tobe;
5409 const struct ssh2_cipher *sccipher_tobe;
5410 const struct ssh_mac *csmac_tobe;
5411 const struct ssh_mac *scmac_tobe;
5412 const struct ssh_compress *cscomp_tobe;
5413 const struct ssh_compress *sccomp_tobe;
5414 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5415 int hostkeylen, siglen, rsakeylen;
5416 void *hkey; /* actual host key */
5417 void *rsakey; /* for RSA kex */
5418 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5419 int n_preferred_kex;
5420 const struct ssh_kexes *preferred_kex[KEX_MAX];
5421 int n_preferred_ciphers;
5422 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5423 const struct ssh_compress *preferred_comp;
5424 int got_session_id, activated_authconn;
5425 struct Packet *pktout;
5430 crState(do_ssh2_transport_state);
5432 crBegin(ssh->do_ssh2_transport_crstate);
5434 s->cscipher_tobe = s->sccipher_tobe = NULL;
5435 s->csmac_tobe = s->scmac_tobe = NULL;
5436 s->cscomp_tobe = s->sccomp_tobe = NULL;
5438 s->got_session_id = s->activated_authconn = FALSE;
5441 * Be prepared to work around the buggy MAC problem.
5443 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5444 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5446 s->maclist = macs, s->nmacs = lenof(macs);
5449 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5451 int i, j, commalist_started;
5454 * Set up the preferred key exchange. (NULL => warn below here)
5456 s->n_preferred_kex = 0;
5457 for (i = 0; i < KEX_MAX; i++) {
5458 switch (ssh->cfg.ssh_kexlist[i]) {
5460 s->preferred_kex[s->n_preferred_kex++] =
5461 &ssh_diffiehellman_gex;
5464 s->preferred_kex[s->n_preferred_kex++] =
5465 &ssh_diffiehellman_group14;
5468 s->preferred_kex[s->n_preferred_kex++] =
5469 &ssh_diffiehellman_group1;
5472 s->preferred_kex[s->n_preferred_kex++] =
5476 /* Flag for later. Don't bother if it's the last in
5478 if (i < KEX_MAX - 1) {
5479 s->preferred_kex[s->n_preferred_kex++] = NULL;
5486 * Set up the preferred ciphers. (NULL => warn below here)
5488 s->n_preferred_ciphers = 0;
5489 for (i = 0; i < CIPHER_MAX; i++) {
5490 switch (ssh->cfg.ssh_cipherlist[i]) {
5491 case CIPHER_BLOWFISH:
5492 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5495 if (ssh->cfg.ssh2_des_cbc) {
5496 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5500 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5503 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5505 case CIPHER_ARCFOUR:
5506 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5509 /* Flag for later. Don't bother if it's the last in
5511 if (i < CIPHER_MAX - 1) {
5512 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5519 * Set up preferred compression.
5521 if (ssh->cfg.compression)
5522 s->preferred_comp = &ssh_zlib;
5524 s->preferred_comp = &ssh_comp_none;
5527 * Enable queueing of outgoing auth- or connection-layer
5528 * packets while we are in the middle of a key exchange.
5530 ssh->queueing = TRUE;
5533 * Flag that KEX is in progress.
5535 ssh->kex_in_progress = TRUE;
5538 * Construct and send our key exchange packet.
5540 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5541 for (i = 0; i < 16; i++)
5542 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5543 /* List key exchange algorithms. */
5544 ssh2_pkt_addstring_start(s->pktout);
5545 commalist_started = 0;
5546 for (i = 0; i < s->n_preferred_kex; i++) {
5547 const struct ssh_kexes *k = s->preferred_kex[i];
5548 if (!k) continue; /* warning flag */
5549 for (j = 0; j < k->nkexes; j++) {
5550 if (commalist_started)
5551 ssh2_pkt_addstring_str(s->pktout, ",");
5552 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5553 commalist_started = 1;
5556 /* List server host key algorithms. */
5557 ssh2_pkt_addstring_start(s->pktout);
5558 for (i = 0; i < lenof(hostkey_algs); i++) {
5559 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5560 if (i < lenof(hostkey_algs) - 1)
5561 ssh2_pkt_addstring_str(s->pktout, ",");
5563 /* List client->server encryption algorithms. */
5564 ssh2_pkt_addstring_start(s->pktout);
5565 commalist_started = 0;
5566 for (i = 0; i < s->n_preferred_ciphers; i++) {
5567 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5568 if (!c) continue; /* warning flag */
5569 for (j = 0; j < c->nciphers; j++) {
5570 if (commalist_started)
5571 ssh2_pkt_addstring_str(s->pktout, ",");
5572 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5573 commalist_started = 1;
5576 /* List server->client encryption algorithms. */
5577 ssh2_pkt_addstring_start(s->pktout);
5578 commalist_started = 0;
5579 for (i = 0; i < s->n_preferred_ciphers; i++) {
5580 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5581 if (!c) continue; /* warning flag */
5582 for (j = 0; j < c->nciphers; j++) {
5583 if (commalist_started)
5584 ssh2_pkt_addstring_str(s->pktout, ",");
5585 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5586 commalist_started = 1;
5589 /* List client->server MAC algorithms. */
5590 ssh2_pkt_addstring_start(s->pktout);
5591 for (i = 0; i < s->nmacs; i++) {
5592 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5593 if (i < s->nmacs - 1)
5594 ssh2_pkt_addstring_str(s->pktout, ",");
5596 /* List server->client MAC algorithms. */
5597 ssh2_pkt_addstring_start(s->pktout);
5598 for (i = 0; i < s->nmacs; i++) {
5599 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5600 if (i < s->nmacs - 1)
5601 ssh2_pkt_addstring_str(s->pktout, ",");
5603 /* List client->server compression algorithms. */
5604 ssh2_pkt_addstring_start(s->pktout);
5605 assert(lenof(compressions) > 1);
5606 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5607 for (i = 0; i < lenof(compressions); i++) {
5608 const struct ssh_compress *c = compressions[i];
5609 if (c != s->preferred_comp) {
5610 ssh2_pkt_addstring_str(s->pktout, ",");
5611 ssh2_pkt_addstring_str(s->pktout, c->name);
5614 /* List server->client compression algorithms. */
5615 ssh2_pkt_addstring_start(s->pktout);
5616 assert(lenof(compressions) > 1);
5617 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5618 for (i = 0; i < lenof(compressions); i++) {
5619 const struct ssh_compress *c = compressions[i];
5620 if (c != s->preferred_comp) {
5621 ssh2_pkt_addstring_str(s->pktout, ",");
5622 ssh2_pkt_addstring_str(s->pktout, c->name);
5625 /* List client->server languages. Empty list. */
5626 ssh2_pkt_addstring_start(s->pktout);
5627 /* List server->client languages. Empty list. */
5628 ssh2_pkt_addstring_start(s->pktout);
5629 /* First KEX packet does _not_ follow, because we're not that brave. */
5630 ssh2_pkt_addbool(s->pktout, FALSE);
5632 ssh2_pkt_adduint32(s->pktout, 0);
5635 s->our_kexinitlen = s->pktout->length - 5;
5636 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5637 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5639 ssh2_pkt_send_noqueue(ssh, s->pktout);
5645 * Now examine the other side's KEXINIT to see what we're up
5649 char *str, *preferred;
5652 if (pktin->type != SSH2_MSG_KEXINIT) {
5653 bombout(("expected key exchange packet from server"));
5657 ssh->hostkey = NULL;
5658 s->cscipher_tobe = NULL;
5659 s->sccipher_tobe = NULL;
5660 s->csmac_tobe = NULL;
5661 s->scmac_tobe = NULL;
5662 s->cscomp_tobe = NULL;
5663 s->sccomp_tobe = NULL;
5664 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5666 pktin->savedpos += 16; /* skip garbage cookie */
5667 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5670 for (i = 0; i < s->n_preferred_kex; i++) {
5671 const struct ssh_kexes *k = s->preferred_kex[i];
5675 for (j = 0; j < k->nkexes; j++) {
5676 if (!preferred) preferred = k->list[j]->name;
5677 if (in_commasep_string(k->list[j]->name, str, len)) {
5678 ssh->kex = k->list[j];
5687 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5688 str ? str : "(null)"));
5692 * Note that the server's guess is considered wrong if it doesn't match
5693 * the first algorithm in our list, even if it's still the algorithm
5696 s->guessok = first_in_commasep_string(preferred, str, len);
5697 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5698 for (i = 0; i < lenof(hostkey_algs); i++) {
5699 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5700 ssh->hostkey = hostkey_algs[i];
5704 s->guessok = s->guessok &&
5705 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5706 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5707 for (i = 0; i < s->n_preferred_ciphers; i++) {
5708 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5710 s->warn_cscipher = TRUE;
5712 for (j = 0; j < c->nciphers; j++) {
5713 if (in_commasep_string(c->list[j]->name, str, len)) {
5714 s->cscipher_tobe = c->list[j];
5719 if (s->cscipher_tobe)
5722 if (!s->cscipher_tobe) {
5723 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5724 str ? str : "(null)"));
5728 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5729 for (i = 0; i < s->n_preferred_ciphers; i++) {
5730 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5732 s->warn_sccipher = TRUE;
5734 for (j = 0; j < c->nciphers; j++) {
5735 if (in_commasep_string(c->list[j]->name, str, len)) {
5736 s->sccipher_tobe = c->list[j];
5741 if (s->sccipher_tobe)
5744 if (!s->sccipher_tobe) {
5745 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5746 str ? str : "(null)"));
5750 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5751 for (i = 0; i < s->nmacs; i++) {
5752 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5753 s->csmac_tobe = s->maclist[i];
5757 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5758 for (i = 0; i < s->nmacs; i++) {
5759 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5760 s->scmac_tobe = s->maclist[i];
5764 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5765 for (i = 0; i < lenof(compressions) + 1; i++) {
5766 const struct ssh_compress *c =
5767 i == 0 ? s->preferred_comp : compressions[i - 1];
5768 if (in_commasep_string(c->name, str, len)) {
5773 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5774 for (i = 0; i < lenof(compressions) + 1; i++) {
5775 const struct ssh_compress *c =
5776 i == 0 ? s->preferred_comp : compressions[i - 1];
5777 if (in_commasep_string(c->name, str, len)) {
5782 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5783 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5784 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5787 ssh_set_frozen(ssh, 1);
5788 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5790 ssh_dialog_callback, ssh);
5791 if (s->dlgret < 0) {
5795 bombout(("Unexpected data from server while"
5796 " waiting for user response"));
5799 } while (pktin || inlen > 0);
5800 s->dlgret = ssh->user_response;
5802 ssh_set_frozen(ssh, 0);
5803 if (s->dlgret == 0) {
5804 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5810 if (s->warn_cscipher) {
5811 ssh_set_frozen(ssh, 1);
5812 s->dlgret = askalg(ssh->frontend,
5813 "client-to-server cipher",
5814 s->cscipher_tobe->name,
5815 ssh_dialog_callback, ssh);
5816 if (s->dlgret < 0) {
5820 bombout(("Unexpected data from server while"
5821 " waiting for user response"));
5824 } while (pktin || inlen > 0);
5825 s->dlgret = ssh->user_response;
5827 ssh_set_frozen(ssh, 0);
5828 if (s->dlgret == 0) {
5829 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5835 if (s->warn_sccipher) {
5836 ssh_set_frozen(ssh, 1);
5837 s->dlgret = askalg(ssh->frontend,
5838 "server-to-client cipher",
5839 s->sccipher_tobe->name,
5840 ssh_dialog_callback, ssh);
5841 if (s->dlgret < 0) {
5845 bombout(("Unexpected data from server while"
5846 " waiting for user response"));
5849 } while (pktin || inlen > 0);
5850 s->dlgret = ssh->user_response;
5852 ssh_set_frozen(ssh, 0);
5853 if (s->dlgret == 0) {
5854 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5860 ssh->exhash = ssh->kex->hash->init();
5861 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5862 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5863 hash_string(ssh->kex->hash, ssh->exhash,
5864 s->our_kexinit, s->our_kexinitlen);
5865 sfree(s->our_kexinit);
5866 if (pktin->length > 5)
5867 hash_string(ssh->kex->hash, ssh->exhash,
5868 pktin->data + 5, pktin->length - 5);
5870 if (s->ignorepkt) /* first_kex_packet_follows */
5871 crWaitUntil(pktin); /* Ignore packet */
5874 if (ssh->kex->main_type == KEXTYPE_DH) {
5876 * Work out the number of bits of key we will need from the
5877 * key exchange. We start with the maximum key length of
5883 csbits = s->cscipher_tobe->keylen;
5884 scbits = s->sccipher_tobe->keylen;
5885 s->nbits = (csbits > scbits ? csbits : scbits);
5887 /* The keys only have hlen-bit entropy, since they're based on
5888 * a hash. So cap the key size at hlen bits. */
5889 if (s->nbits > ssh->kex->hash->hlen * 8)
5890 s->nbits = ssh->kex->hash->hlen * 8;
5893 * If we're doing Diffie-Hellman group exchange, start by
5894 * requesting a group.
5896 if (!ssh->kex->pdata) {
5897 logevent("Doing Diffie-Hellman group exchange");
5898 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
5900 * Work out how big a DH group we will need to allow that
5903 s->pbits = 512 << ((s->nbits - 1) / 64);
5904 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5905 ssh2_pkt_adduint32(s->pktout, s->pbits);
5906 ssh2_pkt_send_noqueue(ssh, s->pktout);
5909 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5910 bombout(("expected key exchange group packet from server"));
5913 s->p = ssh2_pkt_getmp(pktin);
5914 s->g = ssh2_pkt_getmp(pktin);
5915 if (!s->p || !s->g) {
5916 bombout(("unable to read mp-ints from incoming group packet"));
5919 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5920 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5921 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5923 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
5924 ssh->kex_ctx = dh_setup_group(ssh->kex);
5925 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5926 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5927 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5928 ssh->kex->groupname);
5931 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
5932 ssh->kex->hash->text_name);
5934 * Now generate and send e for Diffie-Hellman.
5936 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5937 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5938 s->pktout = ssh2_pkt_init(s->kex_init_value);
5939 ssh2_pkt_addmp(s->pktout, s->e);
5940 ssh2_pkt_send_noqueue(ssh, s->pktout);
5942 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5944 if (pktin->type != s->kex_reply_value) {
5945 bombout(("expected key exchange reply packet from server"));
5948 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5949 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5950 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5951 s->f = ssh2_pkt_getmp(pktin);
5953 bombout(("unable to parse key exchange reply packet"));
5956 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5958 s->K = dh_find_K(ssh->kex_ctx, s->f);
5960 /* We assume everything from now on will be quick, and it might
5961 * involve user interaction. */
5962 set_busy_status(ssh->frontend, BUSY_NOT);
5964 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5965 if (!ssh->kex->pdata) {
5966 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5967 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5968 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5970 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5971 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5973 dh_cleanup(ssh->kex_ctx);
5975 if (!ssh->kex->pdata) {
5980 logeventf(ssh, "Doing RSA key exchange with hash %s",
5981 ssh->kex->hash->text_name);
5982 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
5984 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
5988 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
5989 bombout(("expected RSA public key packet from server"));
5993 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5994 hash_string(ssh->kex->hash, ssh->exhash,
5995 s->hostkeydata, s->hostkeylen);
5996 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6000 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6001 s->rsakeydata = snewn(s->rsakeylen, char);
6002 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6005 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6007 sfree(s->rsakeydata);
6008 bombout(("unable to parse RSA public key from server"));
6012 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6015 * Next, set up a shared secret K, of precisely KLEN -
6016 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6017 * RSA key modulus and HLEN is the bit length of the hash
6021 int klen = ssh_rsakex_klen(s->rsakey);
6022 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6024 unsigned char *kstr1, *kstr2, *outstr;
6025 int kstr1len, kstr2len, outstrlen;
6027 s->K = bn_power_2(nbits - 1);
6029 for (i = 0; i < nbits; i++) {
6031 byte = random_byte();
6033 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6037 * Encode this as an mpint.
6039 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6040 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6041 PUT_32BIT(kstr2, kstr1len);
6042 memcpy(kstr2 + 4, kstr1, kstr1len);
6045 * Encrypt it with the given RSA key.
6047 outstrlen = (klen + 7) / 8;
6048 outstr = snewn(outstrlen, unsigned char);
6049 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6050 outstr, outstrlen, s->rsakey);
6053 * And send it off in a return packet.
6055 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6056 ssh2_pkt_addstring_start(s->pktout);
6057 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6058 ssh2_pkt_send_noqueue(ssh, s->pktout);
6060 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6067 ssh_rsakex_freekey(s->rsakey);
6070 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6071 sfree(s->rsakeydata);
6072 bombout(("expected signature packet from server"));
6076 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6078 sfree(s->rsakeydata);
6081 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6082 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6083 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6085 ssh->kex_ctx = NULL;
6088 debug(("Exchange hash is:\n"));
6089 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6093 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6094 (char *)s->exchange_hash,
6095 ssh->kex->hash->hlen)) {
6096 bombout(("Server's host key did not match the signature supplied"));
6101 * Authenticate remote host: verify host key. (We've already
6102 * checked the signature of the exchange hash.)
6104 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6105 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6106 ssh_set_frozen(ssh, 1);
6107 s->dlgret = verify_ssh_host_key(ssh->frontend,
6108 ssh->savedhost, ssh->savedport,
6109 ssh->hostkey->keytype, s->keystr,
6111 ssh_dialog_callback, ssh);
6112 if (s->dlgret < 0) {
6116 bombout(("Unexpected data from server while waiting"
6117 " for user host key response"));
6120 } while (pktin || inlen > 0);
6121 s->dlgret = ssh->user_response;
6123 ssh_set_frozen(ssh, 0);
6124 if (s->dlgret == 0) {
6125 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6129 if (!s->got_session_id) { /* don't bother logging this in rekeys */
6130 logevent("Host key fingerprint is:");
6131 logevent(s->fingerprint);
6133 sfree(s->fingerprint);
6135 ssh->hostkey->freekey(s->hkey);
6138 * The exchange hash from the very first key exchange is also
6139 * the session id, used in session key construction and
6142 if (!s->got_session_id) {
6143 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6144 memcpy(ssh->v2_session_id, s->exchange_hash,
6145 sizeof(s->exchange_hash));
6146 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6147 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6148 s->got_session_id = TRUE;
6152 * Send SSH2_MSG_NEWKEYS.
6154 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6155 ssh2_pkt_send_noqueue(ssh, s->pktout);
6156 ssh->outgoing_data_size = 0; /* start counting from here */
6159 * We've sent client NEWKEYS, so create and initialise
6160 * client-to-server session keys.
6162 if (ssh->cs_cipher_ctx)
6163 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6164 ssh->cscipher = s->cscipher_tobe;
6165 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6167 if (ssh->cs_mac_ctx)
6168 ssh->csmac->free_context(ssh->cs_mac_ctx);
6169 ssh->csmac = s->csmac_tobe;
6170 ssh->cs_mac_ctx = ssh->csmac->make_context();
6172 if (ssh->cs_comp_ctx)
6173 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6174 ssh->cscomp = s->cscomp_tobe;
6175 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6178 * Set IVs on client-to-server keys. Here we use the exchange
6179 * hash from the _first_ key exchange.
6182 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6183 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6184 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6185 assert((ssh->cscipher->keylen+7) / 8 <=
6186 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6187 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6188 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6189 assert(ssh->cscipher->blksize <=
6190 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6191 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6192 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6193 assert(ssh->csmac->len <=
6194 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6195 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6196 memset(keyspace, 0, sizeof(keyspace));
6199 logeventf(ssh, "Initialised %.200s client->server encryption",
6200 ssh->cscipher->text_name);
6201 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6202 ssh->csmac->text_name);
6203 if (ssh->cscomp->text_name)
6204 logeventf(ssh, "Initialised %s compression",
6205 ssh->cscomp->text_name);
6208 * Now our end of the key exchange is complete, we can send all
6209 * our queued higher-layer packets.
6211 ssh->queueing = FALSE;
6212 ssh2_pkt_queuesend(ssh);
6215 * Expect SSH2_MSG_NEWKEYS from server.
6218 if (pktin->type != SSH2_MSG_NEWKEYS) {
6219 bombout(("expected new-keys packet from server"));
6222 ssh->incoming_data_size = 0; /* start counting from here */
6225 * We've seen server NEWKEYS, so create and initialise
6226 * server-to-client session keys.
6228 if (ssh->sc_cipher_ctx)
6229 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6230 ssh->sccipher = s->sccipher_tobe;
6231 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6233 if (ssh->sc_mac_ctx)
6234 ssh->scmac->free_context(ssh->sc_mac_ctx);
6235 ssh->scmac = s->scmac_tobe;
6236 ssh->sc_mac_ctx = ssh->scmac->make_context();
6238 if (ssh->sc_comp_ctx)
6239 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6240 ssh->sccomp = s->sccomp_tobe;
6241 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6244 * Set IVs on server-to-client keys. Here we use the exchange
6245 * hash from the _first_ key exchange.
6248 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6249 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6250 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6251 assert((ssh->sccipher->keylen+7) / 8 <=
6252 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6253 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6254 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6255 assert(ssh->sccipher->blksize <=
6256 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6257 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6258 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6259 assert(ssh->scmac->len <=
6260 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6261 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6262 memset(keyspace, 0, sizeof(keyspace));
6264 logeventf(ssh, "Initialised %.200s server->client encryption",
6265 ssh->sccipher->text_name);
6266 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6267 ssh->scmac->text_name);
6268 if (ssh->sccomp->text_name)
6269 logeventf(ssh, "Initialised %s decompression",
6270 ssh->sccomp->text_name);
6273 * Free shared secret.
6278 * Key exchange is over. Loop straight back round if we have a
6279 * deferred rekey reason.
6281 if (ssh->deferred_rekey_reason) {
6282 logevent(ssh->deferred_rekey_reason);
6284 ssh->deferred_rekey_reason = NULL;
6285 goto begin_key_exchange;
6289 * Otherwise, schedule a timer for our next rekey.
6291 ssh->kex_in_progress = FALSE;
6292 ssh->last_rekey = GETTICKCOUNT();
6293 if (ssh->cfg.ssh_rekey_time != 0)
6294 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6298 * If this is the first key exchange phase, we must pass the
6299 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6300 * wants to see it but because it will need time to initialise
6301 * itself before it sees an actual packet. In subsequent key
6302 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6303 * it would only confuse the layer above.
6305 if (s->activated_authconn) {
6308 s->activated_authconn = TRUE;
6311 * Now we're encrypting. Begin returning 1 to the protocol main
6312 * function so that other things can run on top of the
6313 * transport. If we ever see a KEXINIT, we must go back to the
6316 * We _also_ go back to the start if we see pktin==NULL and
6317 * inlen==-1, because this is a special signal meaning
6318 * `initiate client-driven rekey', and `in' contains a message
6319 * giving the reason for the rekey.
6321 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6322 (!pktin && inlen == -1))) {
6327 logevent("Server initiated key re-exchange");
6330 * Special case: if the server bug is set that doesn't
6331 * allow rekeying, we give a different log message and
6332 * continue waiting. (If such a server _initiates_ a rekey,
6333 * we process it anyway!)
6335 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6336 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6338 /* Reset the counters, so that at least this message doesn't
6339 * hit the event log _too_ often. */
6340 ssh->outgoing_data_size = 0;
6341 ssh->incoming_data_size = 0;
6342 if (ssh->cfg.ssh_rekey_time != 0) {
6344 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6347 goto wait_for_rekey; /* this is utterly horrid */
6349 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6352 goto begin_key_exchange;
6358 * Add data to an SSH-2 channel output buffer.
6360 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6363 bufchain_add(&c->v.v2.outbuffer, buf, len);
6367 * Attempt to send data on an SSH-2 channel.
6369 static int ssh2_try_send(struct ssh_channel *c)
6372 struct Packet *pktout;
6374 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6377 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6378 if ((unsigned)len > c->v.v2.remwindow)
6379 len = c->v.v2.remwindow;
6380 if ((unsigned)len > c->v.v2.remmaxpkt)
6381 len = c->v.v2.remmaxpkt;
6382 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6383 ssh2_pkt_adduint32(pktout, c->remoteid);
6384 ssh2_pkt_addstring_start(pktout);
6385 dont_log_data(ssh, pktout, PKTLOG_OMIT);
6386 ssh2_pkt_addstring_data(pktout, data, len);
6387 end_log_omission(ssh, pktout);
6388 ssh2_pkt_send(ssh, pktout);
6389 bufchain_consume(&c->v.v2.outbuffer, len);
6390 c->v.v2.remwindow -= len;
6394 * After having sent as much data as we can, return the amount
6397 return bufchain_size(&c->v.v2.outbuffer);
6400 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
6404 return; /* don't send on closing channels */
6405 bufsize = ssh2_try_send(c);
6408 case CHAN_MAINSESSION:
6409 /* stdin need not receive an unthrottle
6410 * notification since it will be polled */
6413 x11_unthrottle(c->u.x11.s);
6416 /* agent sockets are request/response and need no
6417 * buffer management */
6420 pfd_unthrottle(c->u.pfd.s);
6426 * If we've emptied the channel's output buffer and there's a
6427 * pending close event, start the channel-closing procedure.
6429 if (c->pending_close && bufchain_size(&c->v.v2.outbuffer) == 0) {
6430 struct Packet *pktout;
6431 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6432 ssh2_pkt_adduint32(pktout, c->remoteid);
6433 ssh2_pkt_send(ssh, pktout);
6435 c->pending_close = FALSE;
6440 * Set up most of a new ssh_channel for SSH-2.
6442 static void ssh2_channel_init(struct ssh_channel *c)
6445 c->localid = alloc_channel_id(ssh);
6447 c->pending_close = FALSE;
6448 c->throttling_conn = FALSE;
6449 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
6450 ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
6451 c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL;
6452 c->v.v2.throttle_state = UNTHROTTLED;
6453 bufchain_init(&c->v.v2.outbuffer);
6457 * Potentially enlarge the window on an SSH-2 channel.
6459 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6464 * Never send WINDOW_ADJUST for a channel that the remote side
6465 * already thinks it's closed; there's no point, since it won't
6466 * be sending any more data anyway.
6472 * If the remote end has a habit of ignoring maxpkt, limit the
6473 * window so that it has no choice (assuming it doesn't ignore the
6476 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6477 newwin = OUR_V2_MAXPKT;
6481 * Only send a WINDOW_ADJUST if there's significantly more window
6482 * available than the other end thinks there is. This saves us
6483 * sending a WINDOW_ADJUST for every character in a shell session.
6485 * "Significant" is arbitrarily defined as half the window size.
6487 if (newwin / 2 >= c->v.v2.locwindow) {
6488 struct Packet *pktout;
6492 * In order to keep track of how much window the client
6493 * actually has available, we'd like it to acknowledge each
6494 * WINDOW_ADJUST. We can't do that directly, so we accompany
6495 * it with a CHANNEL_REQUEST that has to be acknowledged.
6497 * This is only necessary if we're opening the window wide.
6498 * If we're not, then throughput is being constrained by
6499 * something other than the maximum window size anyway.
6501 * We also only send this if the main channel has finished its
6502 * initial CHANNEL_REQUESTs and installed the default
6503 * CHANNEL_FAILURE handler, so as not to risk giving it
6504 * unexpected CHANNEL_FAILUREs.
6506 if (newwin == c->v.v2.locmaxwin &&
6507 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) {
6508 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6509 ssh2_pkt_adduint32(pktout, c->remoteid);
6510 ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");
6511 ssh2_pkt_addbool(pktout, TRUE);
6512 ssh2_pkt_send(ssh, pktout);
6515 * CHANNEL_FAILURE doesn't come with any indication of
6516 * what message caused it, so we have to keep track of the
6517 * outstanding CHANNEL_REQUESTs ourselves.
6519 wa = snew(struct winadj);
6520 wa->size = newwin - c->v.v2.locwindow;
6522 if (!c->v.v2.winadj_head)
6523 c->v.v2.winadj_head = wa;
6525 c->v.v2.winadj_tail->next = wa;
6526 c->v.v2.winadj_tail = wa;
6527 if (c->v.v2.throttle_state != UNTHROTTLED)
6528 c->v.v2.throttle_state = UNTHROTTLING;
6530 /* Pretend the WINDOW_ADJUST was acked immediately. */
6531 c->v.v2.remlocwin = newwin;
6532 c->v.v2.throttle_state = THROTTLED;
6534 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6535 ssh2_pkt_adduint32(pktout, c->remoteid);
6536 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6537 ssh2_pkt_send(ssh, pktout);
6538 c->v.v2.locwindow = newwin;
6543 * Find the channel associated with a message. If there's no channel,
6544 * or it's not properly open, make a noise about it and return NULL.
6546 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6548 unsigned localid = ssh_pkt_getuint32(pktin);
6549 struct ssh_channel *c;
6551 c = find234(ssh->channels, &localid, ssh_channelfind);
6553 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6554 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6555 char *buf = dupprintf("Received %s for %s channel %u",
6556 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6558 c ? "half-open" : "nonexistent", localid);
6559 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6566 static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin)
6569 * This should never get called. All channel requests are either
6570 * sent with want_reply false or are sent before this handler gets
6573 struct ssh_channel *c;
6576 c = ssh2_channel_msg(ssh, pktin);
6579 wa = c->v.v2.winadj_head;
6581 ssh_disconnect(ssh, NULL, "Received SSH_MSG_CHANNEL_SUCCESS for "
6582 "\"winadj@putty.projects.tartarus.org\"",
6583 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6585 ssh_disconnect(ssh, NULL,
6586 "Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
6587 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6590 static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin)
6593 * The only time this should get called is for "winadj@putty"
6594 * messages sent above. All other channel requests are either
6595 * sent with want_reply false or are sent before this handler gets
6598 struct ssh_channel *c;
6601 c = ssh2_channel_msg(ssh, pktin);
6604 wa = c->v.v2.winadj_head;
6606 ssh_disconnect(ssh, NULL,
6607 "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
6608 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6611 c->v.v2.winadj_head = wa->next;
6612 c->v.v2.remlocwin += wa->size;
6615 * winadj messages are only sent when the window is fully open, so
6616 * if we get an ack of one, we know any pending unthrottle is
6619 if (c->v.v2.throttle_state == UNTHROTTLING)
6620 c->v.v2.throttle_state = UNTHROTTLED;
6623 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6625 struct ssh_channel *c;
6626 c = ssh2_channel_msg(ssh, pktin);
6630 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6631 ssh2_try_send_and_unthrottle(ssh, c);
6635 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6639 struct ssh_channel *c;
6640 c = ssh2_channel_msg(ssh, pktin);
6643 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6644 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6645 return; /* extended but not stderr */
6646 ssh_pkt_getstring(pktin, &data, &length);
6649 c->v.v2.locwindow -= length;
6650 c->v.v2.remlocwin -= length;
6652 case CHAN_MAINSESSION:
6654 from_backend(ssh->frontend, pktin->type ==
6655 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6659 bufsize = x11_send(c->u.x11.s, data, length);
6662 bufsize = pfd_send(c->u.pfd.s, data, length);
6665 while (length > 0) {
6666 if (c->u.a.lensofar < 4) {
6667 unsigned int l = min(4 - c->u.a.lensofar,
6669 memcpy(c->u.a.msglen + c->u.a.lensofar,
6673 c->u.a.lensofar += l;
6675 if (c->u.a.lensofar == 4) {
6677 4 + GET_32BIT(c->u.a.msglen);
6678 c->u.a.message = snewn(c->u.a.totallen,
6680 memcpy(c->u.a.message, c->u.a.msglen, 4);
6682 if (c->u.a.lensofar >= 4 && length > 0) {
6684 min(c->u.a.totallen - c->u.a.lensofar,
6686 memcpy(c->u.a.message + c->u.a.lensofar,
6690 c->u.a.lensofar += l;
6692 if (c->u.a.lensofar == c->u.a.totallen) {
6695 if (agent_query(c->u.a.message,
6698 ssh_agentf_callback, c))
6699 ssh_agentf_callback(c, reply, replylen);
6700 sfree(c->u.a.message);
6701 c->u.a.lensofar = 0;
6708 * If it looks like the remote end hit the end of its window,
6709 * and we didn't want it to do that, think about using a
6712 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6713 c->v.v2.locmaxwin < 0x40000000)
6714 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6716 * If we are not buffering too much data,
6717 * enlarge the window again at the remote side.
6718 * If we are buffering too much, we may still
6719 * need to adjust the window if the server's
6722 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6723 c->v.v2.locmaxwin - bufsize : 0);
6725 * If we're either buffering way too much data, or if we're
6726 * buffering anything at all and we're in "simple" mode,
6727 * throttle the whole channel.
6729 if ((bufsize > c->v.v2.locmaxwin ||
6730 (ssh->cfg.ssh_simple && bufsize > 0)) &&
6731 !c->throttling_conn) {
6732 c->throttling_conn = 1;
6733 ssh_throttle_conn(ssh, +1);
6738 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6740 struct ssh_channel *c;
6742 c = ssh2_channel_msg(ssh, pktin);
6746 if (c->type == CHAN_X11) {
6748 * Remote EOF on an X11 channel means we should
6749 * wrap up and close the channel ourselves.
6751 x11_close(c->u.x11.s);
6754 } else if (c->type == CHAN_AGENT) {
6756 } else if (c->type == CHAN_SOCKDATA) {
6757 pfd_close(c->u.pfd.s);
6763 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6765 struct ssh_channel *c;
6766 struct Packet *pktout;
6768 c = ssh2_channel_msg(ssh, pktin);
6771 /* Do pre-close processing on the channel. */
6773 case CHAN_MAINSESSION:
6774 ssh->mainchan = NULL;
6775 update_specials_menu(ssh->frontend);
6778 if (c->u.x11.s != NULL)
6779 x11_close(c->u.x11.s);
6786 if (c->u.pfd.s != NULL)
6787 pfd_close(c->u.pfd.s);
6791 if (c->closes == 0) {
6792 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6793 ssh2_pkt_adduint32(pktout, c->remoteid);
6794 ssh2_pkt_send(ssh, pktout);
6796 del234(ssh->channels, c);
6797 bufchain_clear(&c->v.v2.outbuffer);
6801 * See if that was the last channel left open.
6802 * (This is only our termination condition if we're
6803 * not running in -N mode.)
6805 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6807 * We used to send SSH_MSG_DISCONNECT here,
6808 * because I'd believed that _every_ conforming
6809 * SSH-2 connection had to end with a disconnect
6810 * being sent by at least one side; apparently
6811 * I was wrong and it's perfectly OK to
6812 * unceremoniously slam the connection shut
6813 * when you're done, and indeed OpenSSH feels
6814 * this is more polite than sending a
6815 * DISCONNECT. So now we don't.
6817 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6821 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6823 struct ssh_channel *c;
6824 struct Packet *pktout;
6826 c = ssh2_channel_msg(ssh, pktin);
6829 if (c->type != CHAN_SOCKDATA_DORMANT)
6830 return; /* dunno why they're confirming this */
6831 c->remoteid = ssh_pkt_getuint32(pktin);
6832 c->halfopen = FALSE;
6833 c->type = CHAN_SOCKDATA;
6834 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6835 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6837 pfd_confirm(c->u.pfd.s);
6840 * We have a pending close on this channel,
6841 * which we decided on before the server acked
6842 * the channel open. So now we know the
6843 * remoteid, we can close it again.
6845 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6846 ssh2_pkt_adduint32(pktout, c->remoteid);
6847 ssh2_pkt_send(ssh, pktout);
6851 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6853 static const char *const reasons[] = {
6854 "<unknown reason code>",
6855 "Administratively prohibited",
6857 "Unknown channel type",
6858 "Resource shortage",
6860 unsigned reason_code;
6861 char *reason_string;
6863 struct ssh_channel *c;
6864 c = ssh2_channel_msg(ssh, pktin);
6867 if (c->type != CHAN_SOCKDATA_DORMANT)
6868 return; /* dunno why they're failing this */
6870 reason_code = ssh_pkt_getuint32(pktin);
6871 if (reason_code >= lenof(reasons))
6872 reason_code = 0; /* ensure reasons[reason_code] in range */
6873 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6874 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6875 reasons[reason_code], reason_length, reason_string);
6877 pfd_close(c->u.pfd.s);
6879 del234(ssh->channels, c);
6883 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6886 int typelen, want_reply;
6887 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6888 struct ssh_channel *c;
6889 struct Packet *pktout;
6891 c = ssh2_channel_msg(ssh, pktin);
6894 ssh_pkt_getstring(pktin, &type, &typelen);
6895 want_reply = ssh2_pkt_getbool(pktin);
6898 * Having got the channel number, we now look at
6899 * the request type string to see if it's something
6902 if (c == ssh->mainchan) {
6904 * We recognise "exit-status" and "exit-signal" on
6905 * the primary channel.
6907 if (typelen == 11 &&
6908 !memcmp(type, "exit-status", 11)) {
6910 ssh->exitcode = ssh_pkt_getuint32(pktin);
6911 logeventf(ssh, "Server sent command exit status %d",
6913 reply = SSH2_MSG_CHANNEL_SUCCESS;
6915 } else if (typelen == 11 &&
6916 !memcmp(type, "exit-signal", 11)) {
6918 int is_plausible = TRUE, is_int = FALSE;
6919 char *fmt_sig = "", *fmt_msg = "";
6921 int msglen = 0, core = FALSE;
6922 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6923 * provide an `int' for the signal, despite its
6924 * having been a `string' in the drafts of RFC 4254 since at
6925 * least 2001. (Fixed in session.c 1.147.) Try to
6926 * infer which we can safely parse it as. */
6928 unsigned char *p = pktin->body +
6930 long len = pktin->length - pktin->savedpos;
6931 unsigned long num = GET_32BIT(p); /* what is it? */
6932 /* If it's 0, it hardly matters; assume string */
6936 int maybe_int = FALSE, maybe_str = FALSE;
6937 #define CHECK_HYPOTHESIS(offset, result) \
6940 if (q >= 0 && q+4 <= len) { \
6941 q = q + 4 + GET_32BIT(p+q); \
6942 if (q >= 0 && q+4 <= len && \
6943 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6947 CHECK_HYPOTHESIS(4+1, maybe_int);
6948 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6949 #undef CHECK_HYPOTHESIS
6950 if (maybe_int && !maybe_str)
6952 else if (!maybe_int && maybe_str)
6955 /* Crikey. Either or neither. Panic. */
6956 is_plausible = FALSE;
6959 ssh->exitcode = 128; /* means `unknown signal' */
6962 /* Old non-standard OpenSSH. */
6963 int signum = ssh_pkt_getuint32(pktin);
6964 fmt_sig = dupprintf(" %d", signum);
6965 ssh->exitcode = 128 + signum;
6967 /* As per RFC 4254. */
6970 ssh_pkt_getstring(pktin, &sig, &siglen);
6971 /* Signal name isn't supposed to be blank, but
6972 * let's cope gracefully if it is. */
6974 fmt_sig = dupprintf(" \"%.*s\"",
6979 * Really hideous method of translating the
6980 * signal description back into a locally
6981 * meaningful number.
6986 #define TRANSLATE_SIGNAL(s) \
6987 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
6988 ssh->exitcode = 128 + SIG ## s
6990 TRANSLATE_SIGNAL(ABRT);
6993 TRANSLATE_SIGNAL(ALRM);
6996 TRANSLATE_SIGNAL(FPE);
6999 TRANSLATE_SIGNAL(HUP);
7002 TRANSLATE_SIGNAL(ILL);
7005 TRANSLATE_SIGNAL(INT);
7008 TRANSLATE_SIGNAL(KILL);
7011 TRANSLATE_SIGNAL(PIPE);
7014 TRANSLATE_SIGNAL(QUIT);
7017 TRANSLATE_SIGNAL(SEGV);
7020 TRANSLATE_SIGNAL(TERM);
7023 TRANSLATE_SIGNAL(USR1);
7026 TRANSLATE_SIGNAL(USR2);
7028 #undef TRANSLATE_SIGNAL
7030 ssh->exitcode = 128;
7032 core = ssh2_pkt_getbool(pktin);
7033 ssh_pkt_getstring(pktin, &msg, &msglen);
7035 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7037 /* ignore lang tag */
7038 } /* else don't attempt to parse */
7039 logeventf(ssh, "Server exited on signal%s%s%s",
7040 fmt_sig, core ? " (core dumped)" : "",
7042 if (*fmt_sig) sfree(fmt_sig);
7043 if (*fmt_msg) sfree(fmt_msg);
7044 reply = SSH2_MSG_CHANNEL_SUCCESS;
7049 * This is a channel request we don't know
7050 * about, so we now either ignore the request
7051 * or respond with CHANNEL_FAILURE, depending
7054 reply = SSH2_MSG_CHANNEL_FAILURE;
7057 pktout = ssh2_pkt_init(reply);
7058 ssh2_pkt_adduint32(pktout, c->remoteid);
7059 ssh2_pkt_send(ssh, pktout);
7063 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7066 int typelen, want_reply;
7067 struct Packet *pktout;
7069 ssh_pkt_getstring(pktin, &type, &typelen);
7070 want_reply = ssh2_pkt_getbool(pktin);
7073 * We currently don't support any global requests
7074 * at all, so we either ignore the request or
7075 * respond with REQUEST_FAILURE, depending on
7079 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7080 ssh2_pkt_send(ssh, pktout);
7084 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7092 struct ssh_channel *c;
7093 unsigned remid, winsize, pktsize;
7094 struct Packet *pktout;
7096 ssh_pkt_getstring(pktin, &type, &typelen);
7097 c = snew(struct ssh_channel);
7100 remid = ssh_pkt_getuint32(pktin);
7101 winsize = ssh_pkt_getuint32(pktin);
7102 pktsize = ssh_pkt_getuint32(pktin);
7104 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7108 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7109 addrstr = snewn(peeraddrlen+1, char);
7110 memcpy(addrstr, peeraddr, peeraddrlen);
7111 addrstr[peeraddrlen] = '\0';
7112 peerport = ssh_pkt_getuint32(pktin);
7114 logeventf(ssh, "Received X11 connect request from %s:%d",
7117 if (!ssh->X11_fwd_enabled)
7118 error = "X11 forwarding is not enabled";
7119 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
7120 addrstr, peerport, &ssh->cfg)) != NULL) {
7121 logeventf(ssh, "Local X11 connection failed: %s", x11err);
7122 error = "Unable to open an X11 connection";
7124 logevent("Opening X11 forward connection succeeded");
7129 } else if (typelen == 15 &&
7130 !memcmp(type, "forwarded-tcpip", 15)) {
7131 struct ssh_rportfwd pf, *realpf;
7134 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7135 pf.sport = ssh_pkt_getuint32(pktin);
7136 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7137 peerport = ssh_pkt_getuint32(pktin);
7138 realpf = find234(ssh->rportfwds, &pf, NULL);
7139 logeventf(ssh, "Received remote port %d open request "
7140 "from %s:%d", pf.sport, peeraddr, peerport);
7141 if (realpf == NULL) {
7142 error = "Remote port is not recognised";
7144 const char *e = pfd_newconnect(&c->u.pfd.s,
7148 realpf->pfrec->addressfamily);
7149 logeventf(ssh, "Attempting to forward remote port to "
7150 "%s:%d", realpf->dhost, realpf->dport);
7152 logeventf(ssh, "Port open failed: %s", e);
7153 error = "Port open failed";
7155 logevent("Forwarded port opened successfully");
7156 c->type = CHAN_SOCKDATA;
7159 } else if (typelen == 22 &&
7160 !memcmp(type, "auth-agent@openssh.com", 22)) {
7161 if (!ssh->agentfwd_enabled)
7162 error = "Agent forwarding is not enabled";
7164 c->type = CHAN_AGENT; /* identify channel type */
7165 c->u.a.lensofar = 0;
7168 error = "Unsupported channel type requested";
7171 c->remoteid = remid;
7172 c->halfopen = FALSE;
7174 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7175 ssh2_pkt_adduint32(pktout, c->remoteid);
7176 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7177 ssh2_pkt_addstring(pktout, error);
7178 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7179 ssh2_pkt_send(ssh, pktout);
7180 logeventf(ssh, "Rejected channel open: %s", error);
7183 ssh2_channel_init(c);
7184 c->v.v2.remwindow = winsize;
7185 c->v.v2.remmaxpkt = pktsize;
7186 add234(ssh->channels, c);
7187 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7188 ssh2_pkt_adduint32(pktout, c->remoteid);
7189 ssh2_pkt_adduint32(pktout, c->localid);
7190 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
7191 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7192 ssh2_pkt_send(ssh, pktout);
7197 * Buffer banner messages for later display at some convenient point.
7199 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7201 /* Arbitrary limit to prevent unbounded inflation of buffer */
7202 if (bufchain_size(&ssh->banner) <= 131072) {
7203 char *banner = NULL;
7205 ssh_pkt_getstring(pktin, &banner, &size);
7207 bufchain_add(&ssh->banner, banner, size);
7211 /* Helper function to deal with sending tty modes for "pty-req" */
7212 static void ssh2_send_ttymode(void *data, char *mode, char *val)
7214 struct Packet *pktout = (struct Packet *)data;
7216 unsigned int arg = 0;
7217 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7218 if (i == lenof(ssh_ttymodes)) return;
7219 switch (ssh_ttymodes[i].type) {
7221 arg = ssh_tty_parse_specchar(val);
7224 arg = ssh_tty_parse_boolean(val);
7227 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7228 ssh2_pkt_adduint32(pktout, arg);
7232 * Handle the SSH-2 userauth and connection layers.
7234 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7235 struct Packet *pktin)
7237 struct do_ssh2_authconn_state {
7240 AUTH_TYPE_PUBLICKEY,
7241 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7242 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7245 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7246 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7248 int done_service_req;
7249 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
7250 int tried_pubkey_config, done_agent;
7255 int kbd_inter_refused;
7257 prompts_t *cur_prompt;
7262 void *publickey_blob;
7263 int publickey_bloblen;
7264 int publickey_encrypted;
7265 char *publickey_algorithm;
7266 char *publickey_comment;
7267 unsigned char agent_request[5], *agent_response, *agentp;
7268 int agent_responselen;
7269 unsigned char *pkblob_in_agent;
7271 char *pkblob, *alg, *commentp;
7272 int pklen, alglen, commentlen;
7273 int siglen, retlen, len;
7274 char *q, *agentreq, *ret;
7276 int num_env, env_left, env_ok;
7277 struct Packet *pktout;
7279 struct ssh_gss_library *gsslib;
7280 Ssh_gss_ctx gss_ctx;
7281 Ssh_gss_buf gss_buf;
7282 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7283 Ssh_gss_name gss_srv_name;
7284 Ssh_gss_stat gss_stat;
7287 crState(do_ssh2_authconn_state);
7289 crBegin(ssh->do_ssh2_authconn_crstate);
7291 s->done_service_req = FALSE;
7292 s->we_are_in = FALSE;
7294 s->tried_gssapi = FALSE;
7297 if (!ssh->cfg.ssh_no_userauth) {
7299 * Request userauth protocol, and await a response to it.
7301 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7302 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7303 ssh2_pkt_send(ssh, s->pktout);
7304 crWaitUntilV(pktin);
7305 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7306 s->done_service_req = TRUE;
7308 if (!s->done_service_req) {
7310 * Request connection protocol directly, without authentication.
7312 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7313 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7314 ssh2_pkt_send(ssh, s->pktout);
7315 crWaitUntilV(pktin);
7316 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7317 s->we_are_in = TRUE; /* no auth required */
7319 bombout(("Server refused service request"));
7324 /* Arrange to be able to deal with any BANNERs that come in.
7325 * (We do this now as packets may come in during the next bit.) */
7326 bufchain_init(&ssh->banner);
7327 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7328 ssh2_msg_userauth_banner;
7331 * Misc one-time setup for authentication.
7333 s->publickey_blob = NULL;
7334 if (!s->we_are_in) {
7337 * Load the public half of any configured public key file
7340 if (!filename_is_null(ssh->cfg.keyfile)) {
7342 logeventf(ssh, "Reading private key file \"%.150s\"",
7343 filename_to_str(&ssh->cfg.keyfile));
7344 keytype = key_type(&ssh->cfg.keyfile);
7345 if (keytype == SSH_KEYTYPE_SSH2) {
7348 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
7349 &s->publickey_algorithm,
7350 &s->publickey_bloblen,
7351 &s->publickey_comment, &error);
7352 if (s->publickey_blob) {
7353 s->publickey_encrypted =
7354 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
7357 logeventf(ssh, "Unable to load private key (%s)",
7359 msgbuf = dupprintf("Unable to load private key file "
7360 "\"%.150s\" (%s)\r\n",
7361 filename_to_str(&ssh->cfg.keyfile),
7363 c_write_str(ssh, msgbuf);
7368 logeventf(ssh, "Unable to use this key file (%s)",
7369 key_type_to_str(keytype));
7370 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7372 filename_to_str(&ssh->cfg.keyfile),
7373 key_type_to_str(keytype));
7374 c_write_str(ssh, msgbuf);
7376 s->publickey_blob = NULL;
7381 * Find out about any keys Pageant has (but if there's a
7382 * public key configured, filter out all others).
7385 s->agent_response = NULL;
7386 s->pkblob_in_agent = NULL;
7387 if (ssh->cfg.tryagent && agent_exists()) {
7391 logevent("Pageant is running. Requesting keys.");
7393 /* Request the keys held by the agent. */
7394 PUT_32BIT(s->agent_request, 1);
7395 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7396 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7397 ssh_agent_callback, ssh)) {
7401 bombout(("Unexpected data from server while"
7402 " waiting for agent response"));
7405 } while (pktin || inlen > 0);
7406 r = ssh->agent_response;
7407 s->agent_responselen = ssh->agent_response_len;
7409 s->agent_response = (unsigned char *) r;
7410 if (s->agent_response && s->agent_responselen >= 5 &&
7411 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7414 p = s->agent_response + 5;
7415 s->nkeys = GET_32BIT(p);
7417 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
7418 if (s->publickey_blob) {
7419 /* See if configured key is in agent. */
7420 for (keyi = 0; keyi < s->nkeys; keyi++) {
7421 s->pklen = GET_32BIT(p);
7422 if (s->pklen == s->publickey_bloblen &&
7423 !memcmp(p+4, s->publickey_blob,
7424 s->publickey_bloblen)) {
7425 logeventf(ssh, "Pageant key #%d matches "
7426 "configured key file", keyi);
7428 s->pkblob_in_agent = p;
7432 p += GET_32BIT(p) + 4; /* comment */
7434 if (!s->pkblob_in_agent) {
7435 logevent("Configured key file not in Pageant");
7445 * We repeat this whole loop, including the username prompt,
7446 * until we manage a successful authentication. If the user
7447 * types the wrong _password_, they can be sent back to the
7448 * beginning to try another username, if this is configured on.
7449 * (If they specify a username in the config, they are never
7450 * asked, even if they do give a wrong password.)
7452 * I think this best serves the needs of
7454 * - the people who have no configuration, no keys, and just
7455 * want to try repeated (username,password) pairs until they
7456 * type both correctly
7458 * - people who have keys and configuration but occasionally
7459 * need to fall back to passwords
7461 * - people with a key held in Pageant, who might not have
7462 * logged in to a particular machine before; so they want to
7463 * type a username, and then _either_ their key will be
7464 * accepted, _or_ they will type a password. If they mistype
7465 * the username they will want to be able to get back and
7468 s->username[0] = '\0';
7469 s->got_username = FALSE;
7470 while (!s->we_are_in) {
7474 if (s->got_username && !ssh->cfg.change_username) {
7476 * We got a username last time round this loop, and
7477 * with change_username turned off we don't try to get
7480 } else if (!get_remote_username(&ssh->cfg, s->username,
7481 sizeof(s->username))) {
7482 int ret; /* need not be kept over crReturn */
7483 s->cur_prompt = new_prompts(ssh->frontend);
7484 s->cur_prompt->to_server = TRUE;
7485 s->cur_prompt->name = dupstr("SSH login name");
7486 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
7487 lenof(s->username));
7488 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7491 crWaitUntilV(!pktin);
7492 ret = get_userpass_input(s->cur_prompt, in, inlen);
7497 * get_userpass_input() failed to get a username.
7500 free_prompts(s->cur_prompt);
7501 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7504 memcpy(s->username, s->cur_prompt->prompts[0]->result,
7505 lenof(s->username));
7506 free_prompts(s->cur_prompt);
7509 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7510 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
7511 c_write_str(ssh, stuff);
7515 s->got_username = TRUE;
7518 * Send an authentication request using method "none": (a)
7519 * just in case it succeeds, and (b) so that we know what
7520 * authentication methods we can usefully try next.
7522 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7524 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7525 ssh2_pkt_addstring(s->pktout, s->username);
7526 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7527 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7528 ssh2_pkt_send(ssh, s->pktout);
7529 s->type = AUTH_TYPE_NONE;
7531 s->we_are_in = FALSE;
7533 s->tried_pubkey_config = FALSE;
7534 s->kbd_inter_refused = FALSE;
7536 /* Reset agent request state. */
7537 s->done_agent = FALSE;
7538 if (s->agent_response) {
7539 if (s->pkblob_in_agent) {
7540 s->agentp = s->pkblob_in_agent;
7542 s->agentp = s->agent_response + 5 + 4;
7548 char *methods = NULL;
7552 * Wait for the result of the last authentication request.
7555 crWaitUntilV(pktin);
7557 * Now is a convenient point to spew any banner material
7558 * that we've accumulated. (This should ensure that when
7559 * we exit the auth loop, we haven't any left to deal
7563 int size = bufchain_size(&ssh->banner);
7565 * Don't show the banner if we're operating in
7566 * non-verbose non-interactive mode. (It's probably
7567 * a script, which means nobody will read the
7568 * banner _anyway_, and moreover the printing of
7569 * the banner will screw up processing on the
7570 * output of (say) plink.)
7572 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7573 char *banner = snewn(size, char);
7574 bufchain_fetch(&ssh->banner, banner, size);
7575 c_write_untrusted(ssh, banner, size);
7578 bufchain_clear(&ssh->banner);
7580 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
7581 logevent("Access granted");
7582 s->we_are_in = TRUE;
7586 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
7587 bombout(("Strange packet received during authentication: "
7588 "type %d", pktin->type));
7595 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7596 * we can look at the string in it and know what we can
7597 * helpfully try next.
7599 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
7600 ssh_pkt_getstring(pktin, &methods, &methlen);
7601 if (!ssh2_pkt_getbool(pktin)) {
7603 * We have received an unequivocal Access
7604 * Denied. This can translate to a variety of
7607 * - if we'd just tried "none" authentication,
7608 * it's not worth printing anything at all
7610 * - if we'd just tried a public key _offer_,
7611 * the message should be "Server refused our
7612 * key" (or no message at all if the key
7613 * came from Pageant)
7615 * - if we'd just tried anything else, the
7616 * message really should be "Access denied".
7618 * Additionally, if we'd just tried password
7619 * authentication, we should break out of this
7620 * whole loop so as to go back to the username
7621 * prompt (iff we're configured to allow
7622 * username change attempts).
7624 if (s->type == AUTH_TYPE_NONE) {
7626 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7627 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7628 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7629 c_write_str(ssh, "Server refused our key\r\n");
7630 logevent("Server refused public key");
7631 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
7632 /* server declined keyboard-interactive; ignore */
7634 c_write_str(ssh, "Access denied\r\n");
7635 logevent("Access denied");
7636 if (s->type == AUTH_TYPE_PASSWORD &&
7637 ssh->cfg.change_username) {
7638 /* XXX perhaps we should allow
7639 * keyboard-interactive to do this too? */
7640 s->we_are_in = FALSE;
7645 c_write_str(ssh, "Further authentication required\r\n");
7646 logevent("Further authentication required");
7650 in_commasep_string("publickey", methods, methlen);
7652 in_commasep_string("password", methods, methlen);
7653 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
7654 in_commasep_string("keyboard-interactive", methods, methlen);
7657 ssh->gsslibs = ssh_gss_setup(&ssh->cfg);
7658 s->can_gssapi = ssh->cfg.try_gssapi_auth &&
7659 in_commasep_string("gssapi-with-mic", methods, methlen) &&
7660 ssh->gsslibs->nlibraries > 0;
7664 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7666 if (s->can_pubkey && !s->done_agent && s->nkeys) {
7669 * Attempt public-key authentication using a key from Pageant.
7672 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7674 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7676 /* Unpack key from agent response */
7677 s->pklen = GET_32BIT(s->agentp);
7679 s->pkblob = (char *)s->agentp;
7680 s->agentp += s->pklen;
7681 s->alglen = GET_32BIT(s->pkblob);
7682 s->alg = s->pkblob + 4;
7683 s->commentlen = GET_32BIT(s->agentp);
7685 s->commentp = (char *)s->agentp;
7686 s->agentp += s->commentlen;
7687 /* s->agentp now points at next key, if any */
7689 /* See if server will accept it */
7690 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7691 ssh2_pkt_addstring(s->pktout, s->username);
7692 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7693 /* service requested */
7694 ssh2_pkt_addstring(s->pktout, "publickey");
7696 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7697 ssh2_pkt_addstring_start(s->pktout);
7698 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7699 ssh2_pkt_addstring_start(s->pktout);
7700 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7701 ssh2_pkt_send(ssh, s->pktout);
7702 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
7704 crWaitUntilV(pktin);
7705 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7707 /* Offer of key refused. */
7714 if (flags & FLAG_VERBOSE) {
7715 c_write_str(ssh, "Authenticating with "
7717 c_write(ssh, s->commentp, s->commentlen);
7718 c_write_str(ssh, "\" from agent\r\n");
7722 * Server is willing to accept the key.
7723 * Construct a SIGN_REQUEST.
7725 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7726 ssh2_pkt_addstring(s->pktout, s->username);
7727 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7728 /* service requested */
7729 ssh2_pkt_addstring(s->pktout, "publickey");
7731 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7732 ssh2_pkt_addstring_start(s->pktout);
7733 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7734 ssh2_pkt_addstring_start(s->pktout);
7735 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7737 /* Ask agent for signature. */
7738 s->siglen = s->pktout->length - 5 + 4 +
7739 ssh->v2_session_id_len;
7740 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7742 s->len = 1; /* message type */
7743 s->len += 4 + s->pklen; /* key blob */
7744 s->len += 4 + s->siglen; /* data to sign */
7745 s->len += 4; /* flags */
7746 s->agentreq = snewn(4 + s->len, char);
7747 PUT_32BIT(s->agentreq, s->len);
7748 s->q = s->agentreq + 4;
7749 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
7750 PUT_32BIT(s->q, s->pklen);
7752 memcpy(s->q, s->pkblob, s->pklen);
7754 PUT_32BIT(s->q, s->siglen);
7756 /* Now the data to be signed... */
7757 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7758 PUT_32BIT(s->q, ssh->v2_session_id_len);
7761 memcpy(s->q, ssh->v2_session_id,
7762 ssh->v2_session_id_len);
7763 s->q += ssh->v2_session_id_len;
7764 memcpy(s->q, s->pktout->data + 5,
7765 s->pktout->length - 5);
7766 s->q += s->pktout->length - 5;
7767 /* And finally the (zero) flags word. */
7769 if (!agent_query(s->agentreq, s->len + 4,
7771 ssh_agent_callback, ssh)) {
7775 bombout(("Unexpected data from server"
7776 " while waiting for agent"
7780 } while (pktin || inlen > 0);
7781 vret = ssh->agent_response;
7782 s->retlen = ssh->agent_response_len;
7787 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
7788 logevent("Sending Pageant's response");
7789 ssh2_add_sigblob(ssh, s->pktout,
7790 s->pkblob, s->pklen,
7792 GET_32BIT(s->ret + 5));
7793 ssh2_pkt_send(ssh, s->pktout);
7794 s->type = AUTH_TYPE_PUBLICKEY;
7796 /* FIXME: less drastic response */
7797 bombout(("Pageant failed to answer challenge"));
7803 /* Do we have any keys left to try? */
7804 if (s->pkblob_in_agent) {
7805 s->done_agent = TRUE;
7806 s->tried_pubkey_config = TRUE;
7809 if (s->keyi >= s->nkeys)
7810 s->done_agent = TRUE;
7813 } else if (s->can_pubkey && s->publickey_blob &&
7814 !s->tried_pubkey_config) {
7816 struct ssh2_userkey *key; /* not live over crReturn */
7817 char *passphrase; /* not live over crReturn */
7819 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7821 s->tried_pubkey_config = TRUE;
7824 * Try the public key supplied in the configuration.
7826 * First, offer the public blob to see if the server is
7827 * willing to accept it.
7829 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7830 ssh2_pkt_addstring(s->pktout, s->username);
7831 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7832 /* service requested */
7833 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7834 ssh2_pkt_addbool(s->pktout, FALSE);
7835 /* no signature included */
7836 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7837 ssh2_pkt_addstring_start(s->pktout);
7838 ssh2_pkt_addstring_data(s->pktout,
7839 (char *)s->publickey_blob,
7840 s->publickey_bloblen);
7841 ssh2_pkt_send(ssh, s->pktout);
7842 logevent("Offered public key");
7844 crWaitUntilV(pktin);
7845 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7846 /* Key refused. Give up. */
7847 s->gotit = TRUE; /* reconsider message next loop */
7848 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7849 continue; /* process this new message */
7851 logevent("Offer of public key accepted");
7854 * Actually attempt a serious authentication using
7857 if (flags & FLAG_VERBOSE) {
7858 c_write_str(ssh, "Authenticating with public key \"");
7859 c_write_str(ssh, s->publickey_comment);
7860 c_write_str(ssh, "\"\r\n");
7864 const char *error; /* not live over crReturn */
7865 if (s->publickey_encrypted) {
7867 * Get a passphrase from the user.
7869 int ret; /* need not be kept over crReturn */
7870 s->cur_prompt = new_prompts(ssh->frontend);
7871 s->cur_prompt->to_server = FALSE;
7872 s->cur_prompt->name = dupstr("SSH key passphrase");
7873 add_prompt(s->cur_prompt,
7874 dupprintf("Passphrase for key \"%.100s\": ",
7875 s->publickey_comment),
7876 FALSE, SSH_MAX_PASSWORD_LEN);
7877 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7880 crWaitUntilV(!pktin);
7881 ret = get_userpass_input(s->cur_prompt,
7886 /* Failed to get a passphrase. Terminate. */
7887 free_prompts(s->cur_prompt);
7888 ssh_disconnect(ssh, NULL,
7889 "Unable to authenticate",
7890 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7895 dupstr(s->cur_prompt->prompts[0]->result);
7896 free_prompts(s->cur_prompt);
7898 passphrase = NULL; /* no passphrase needed */
7902 * Try decrypting the key.
7904 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7907 /* burn the evidence */
7908 memset(passphrase, 0, strlen(passphrase));
7911 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7913 (key == SSH2_WRONG_PASSPHRASE)) {
7914 c_write_str(ssh, "Wrong passphrase\r\n");
7916 /* and loop again */
7918 c_write_str(ssh, "Unable to load private key (");
7919 c_write_str(ssh, error);
7920 c_write_str(ssh, ")\r\n");
7922 break; /* try something else */
7928 unsigned char *pkblob, *sigblob, *sigdata;
7929 int pkblob_len, sigblob_len, sigdata_len;
7933 * We have loaded the private key and the server
7934 * has announced that it's willing to accept it.
7935 * Hallelujah. Generate a signature and send it.
7937 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7938 ssh2_pkt_addstring(s->pktout, s->username);
7939 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7940 /* service requested */
7941 ssh2_pkt_addstring(s->pktout, "publickey");
7943 ssh2_pkt_addbool(s->pktout, TRUE);
7944 /* signature follows */
7945 ssh2_pkt_addstring(s->pktout, key->alg->name);
7946 pkblob = key->alg->public_blob(key->data,
7948 ssh2_pkt_addstring_start(s->pktout);
7949 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
7953 * The data to be signed is:
7957 * followed by everything so far placed in the
7960 sigdata_len = s->pktout->length - 5 + 4 +
7961 ssh->v2_session_id_len;
7962 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7964 sigdata = snewn(sigdata_len, unsigned char);
7966 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7967 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7970 memcpy(sigdata+p, ssh->v2_session_id,
7971 ssh->v2_session_id_len);
7972 p += ssh->v2_session_id_len;
7973 memcpy(sigdata+p, s->pktout->data + 5,
7974 s->pktout->length - 5);
7975 p += s->pktout->length - 5;
7976 assert(p == sigdata_len);
7977 sigblob = key->alg->sign(key->data, (char *)sigdata,
7978 sigdata_len, &sigblob_len);
7979 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7980 sigblob, sigblob_len);
7985 ssh2_pkt_send(ssh, s->pktout);
7986 s->type = AUTH_TYPE_PUBLICKEY;
7987 key->alg->freekey(key->data);
7991 } else if (s->can_gssapi && !s->tried_gssapi) {
7993 /* GSSAPI Authentication */
7998 s->type = AUTH_TYPE_GSSAPI;
7999 s->tried_gssapi = TRUE;
8001 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8004 * Pick the highest GSS library on the preference
8010 for (i = 0; i < ngsslibs; i++) {
8011 int want_id = ssh->cfg.ssh_gsslist[i];
8012 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8013 if (ssh->gsslibs->libraries[j].id == want_id) {
8014 s->gsslib = &ssh->gsslibs->libraries[j];
8015 goto got_gsslib; /* double break */
8020 * We always expect to have found something in
8021 * the above loop: we only came here if there
8022 * was at least one viable GSS library, and the
8023 * preference list should always mention
8024 * everything and only change the order.
8029 if (s->gsslib->gsslogmsg)
8030 logevent(s->gsslib->gsslogmsg);
8032 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8033 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8034 ssh2_pkt_addstring(s->pktout, s->username);
8035 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8036 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8038 /* add mechanism info */
8039 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
8041 /* number of GSSAPI mechanisms */
8042 ssh2_pkt_adduint32(s->pktout,1);
8044 /* length of OID + 2 */
8045 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
8046 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8049 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
8051 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8053 ssh2_pkt_send(ssh, s->pktout);
8054 crWaitUntilV(pktin);
8055 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8056 logevent("GSSAPI authentication request refused");
8060 /* check returned packet ... */
8062 ssh_pkt_getstring(pktin, &data, &len);
8063 s->gss_rcvtok.value = data;
8064 s->gss_rcvtok.length = len;
8065 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8066 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8067 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8068 memcmp((char *)s->gss_rcvtok.value + 2,
8069 s->gss_buf.value,s->gss_buf.length) ) {
8070 logevent("GSSAPI authentication - wrong response from server");
8074 /* now start running */
8075 s->gss_stat = s->gsslib->import_name(s->gsslib,
8078 if (s->gss_stat != SSH_GSS_OK) {
8079 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8080 logevent("GSSAPI import name failed - Bad service name");
8082 logevent("GSSAPI import name failed");
8086 /* fetch TGT into GSS engine */
8087 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
8089 if (s->gss_stat != SSH_GSS_OK) {
8090 logevent("GSSAPI authentication failed to get credentials");
8091 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8095 /* initial tokens are empty */
8096 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
8097 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
8099 /* now enter the loop */
8101 s->gss_stat = s->gsslib->init_sec_context
8109 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8110 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8111 logevent("GSSAPI authentication initialisation failed");
8113 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8114 &s->gss_buf) == SSH_GSS_OK) {
8115 logevent(s->gss_buf.value);
8116 sfree(s->gss_buf.value);
8121 logevent("GSSAPI authentication initialised");
8123 /* Client and server now exchange tokens until GSSAPI
8124 * no longer says CONTINUE_NEEDED */
8126 if (s->gss_sndtok.length != 0) {
8127 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8128 ssh_pkt_addstring_start(s->pktout);
8129 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
8130 ssh2_pkt_send(ssh, s->pktout);
8131 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
8134 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8135 crWaitUntilV(pktin);
8136 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8137 logevent("GSSAPI authentication - bad server response");
8138 s->gss_stat = SSH_GSS_FAILURE;
8141 ssh_pkt_getstring(pktin, &data, &len);
8142 s->gss_rcvtok.value = data;
8143 s->gss_rcvtok.length = len;
8145 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8147 if (s->gss_stat != SSH_GSS_OK) {
8148 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8149 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8152 logevent("GSSAPI authentication loop finished OK");
8154 /* Now send the MIC */
8156 s->pktout = ssh2_pkt_init(0);
8157 micoffset = s->pktout->length;
8158 ssh_pkt_addstring_start(s->pktout);
8159 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8160 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
8161 ssh_pkt_addstring(s->pktout, s->username);
8162 ssh_pkt_addstring(s->pktout, "ssh-connection");
8163 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8165 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8166 s->gss_buf.length = s->pktout->length - micoffset;
8168 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
8169 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8170 ssh_pkt_addstring_start(s->pktout);
8171 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
8172 ssh2_pkt_send(ssh, s->pktout);
8173 s->gsslib->free_mic(s->gsslib, &mic);
8177 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8178 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8181 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8184 * Keyboard-interactive authentication.
8187 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8189 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
8191 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8192 ssh2_pkt_addstring(s->pktout, s->username);
8193 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8194 /* service requested */
8195 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8197 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8198 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8199 ssh2_pkt_send(ssh, s->pktout);
8201 crWaitUntilV(pktin);
8202 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8203 /* Server is not willing to do keyboard-interactive
8204 * at all (or, bizarrely but legally, accepts the
8205 * user without actually issuing any prompts).
8206 * Give up on it entirely. */
8208 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
8209 logevent("Keyboard-interactive authentication refused");
8210 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8211 s->kbd_inter_refused = TRUE; /* don't try it again */
8216 * Loop while the server continues to send INFO_REQUESTs.
8218 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
8220 char *name, *inst, *lang;
8221 int name_len, inst_len, lang_len;
8225 * We've got a fresh USERAUTH_INFO_REQUEST.
8226 * Get the preamble and start building a prompt.
8228 ssh_pkt_getstring(pktin, &name, &name_len);
8229 ssh_pkt_getstring(pktin, &inst, &inst_len);
8230 ssh_pkt_getstring(pktin, &lang, &lang_len);
8231 s->cur_prompt = new_prompts(ssh->frontend);
8232 s->cur_prompt->to_server = TRUE;
8235 * Get any prompt(s) from the packet.
8237 s->num_prompts = ssh_pkt_getuint32(pktin);
8238 for (i = 0; i < s->num_prompts; i++) {
8242 static char noprompt[] =
8243 "<server failed to send prompt>: ";
8245 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8246 echo = ssh2_pkt_getbool(pktin);
8249 prompt_len = lenof(noprompt)-1;
8251 add_prompt(s->cur_prompt,
8252 dupprintf("%.*s", prompt_len, prompt),
8253 echo, SSH_MAX_PASSWORD_LEN);
8257 /* FIXME: better prefix to distinguish from
8259 s->cur_prompt->name =
8260 dupprintf("SSH server: %.*s", name_len, name);
8261 s->cur_prompt->name_reqd = TRUE;
8263 s->cur_prompt->name =
8264 dupstr("SSH server authentication");
8265 s->cur_prompt->name_reqd = FALSE;
8267 /* We add a prefix to try to make it clear that a prompt
8268 * has come from the server.
8269 * FIXME: ugly to print "Using..." in prompt _every_
8270 * time round. Can this be done more subtly? */
8271 /* Special case: for reasons best known to themselves,
8272 * some servers send k-i requests with no prompts and
8273 * nothing to display. Keep quiet in this case. */
8274 if (s->num_prompts || name_len || inst_len) {
8275 s->cur_prompt->instruction =
8276 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8277 inst_len ? "\n" : "", inst_len, inst);
8278 s->cur_prompt->instr_reqd = TRUE;
8280 s->cur_prompt->instr_reqd = FALSE;
8284 * Display any instructions, and get the user's
8288 int ret; /* not live over crReturn */
8289 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8292 crWaitUntilV(!pktin);
8293 ret = get_userpass_input(s->cur_prompt, in, inlen);
8298 * Failed to get responses. Terminate.
8300 free_prompts(s->cur_prompt);
8301 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8302 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8309 * Send the response(s) to the server.
8311 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
8312 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8313 for (i=0; i < s->num_prompts; i++) {
8314 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8315 ssh2_pkt_addstring(s->pktout,
8316 s->cur_prompt->prompts[i]->result);
8317 end_log_omission(ssh, s->pktout);
8319 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8322 * Get the next packet in case it's another
8325 crWaitUntilV(pktin);
8330 * We should have SUCCESS or FAILURE now.
8334 } else if (s->can_passwd) {
8337 * Plain old password authentication.
8339 int ret; /* not live over crReturn */
8340 int changereq_first_time; /* not live over crReturn */
8342 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
8344 s->cur_prompt = new_prompts(ssh->frontend);
8345 s->cur_prompt->to_server = TRUE;
8346 s->cur_prompt->name = dupstr("SSH password");
8347 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
8350 FALSE, SSH_MAX_PASSWORD_LEN);
8352 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8355 crWaitUntilV(!pktin);
8356 ret = get_userpass_input(s->cur_prompt, in, inlen);
8361 * Failed to get responses. Terminate.
8363 free_prompts(s->cur_prompt);
8364 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8365 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8370 * Squirrel away the password. (We may need it later if
8371 * asked to change it.)
8373 s->password = dupstr(s->cur_prompt->prompts[0]->result);
8374 free_prompts(s->cur_prompt);
8377 * Send the password packet.
8379 * We pad out the password packet to 256 bytes to make
8380 * it harder for an attacker to find the length of the
8383 * Anyone using a password longer than 256 bytes
8384 * probably doesn't have much to worry about from
8385 * people who find out how long their password is!
8387 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8388 ssh2_pkt_addstring(s->pktout, s->username);
8389 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8390 /* service requested */
8391 ssh2_pkt_addstring(s->pktout, "password");
8392 ssh2_pkt_addbool(s->pktout, FALSE);
8393 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8394 ssh2_pkt_addstring(s->pktout, s->password);
8395 end_log_omission(ssh, s->pktout);
8396 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8397 logevent("Sent password");
8398 s->type = AUTH_TYPE_PASSWORD;
8401 * Wait for next packet, in case it's a password change
8404 crWaitUntilV(pktin);
8405 changereq_first_time = TRUE;
8407 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
8410 * We're being asked for a new password
8411 * (perhaps not for the first time).
8412 * Loop until the server accepts it.
8415 int got_new = FALSE; /* not live over crReturn */
8416 char *prompt; /* not live over crReturn */
8417 int prompt_len; /* not live over crReturn */
8421 if (changereq_first_time)
8422 msg = "Server requested password change";
8424 msg = "Server rejected new password";
8426 c_write_str(ssh, msg);
8427 c_write_str(ssh, "\r\n");
8430 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8432 s->cur_prompt = new_prompts(ssh->frontend);
8433 s->cur_prompt->to_server = TRUE;
8434 s->cur_prompt->name = dupstr("New SSH password");
8435 s->cur_prompt->instruction =
8436 dupprintf("%.*s", prompt_len, prompt);
8437 s->cur_prompt->instr_reqd = TRUE;
8439 * There's no explicit requirement in the protocol
8440 * for the "old" passwords in the original and
8441 * password-change messages to be the same, and
8442 * apparently some Cisco kit supports password change
8443 * by the user entering a blank password originally
8444 * and the real password subsequently, so,
8445 * reluctantly, we prompt for the old password again.
8447 * (On the other hand, some servers don't even bother
8448 * to check this field.)
8450 add_prompt(s->cur_prompt,
8451 dupstr("Current password (blank for previously entered password): "),
8452 FALSE, SSH_MAX_PASSWORD_LEN);
8453 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
8454 FALSE, SSH_MAX_PASSWORD_LEN);
8455 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
8456 FALSE, SSH_MAX_PASSWORD_LEN);
8459 * Loop until the user manages to enter the same
8464 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8467 crWaitUntilV(!pktin);
8468 ret = get_userpass_input(s->cur_prompt, in, inlen);
8473 * Failed to get responses. Terminate.
8475 /* burn the evidence */
8476 free_prompts(s->cur_prompt);
8477 memset(s->password, 0, strlen(s->password));
8479 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8480 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8486 * If the user specified a new original password
8487 * (IYSWIM), overwrite any previously specified
8489 * (A side effect is that the user doesn't have to
8490 * re-enter it if they louse up the new password.)
8492 if (s->cur_prompt->prompts[0]->result[0]) {
8493 memset(s->password, 0, strlen(s->password));
8494 /* burn the evidence */
8497 dupstr(s->cur_prompt->prompts[0]->result);
8501 * Check the two new passwords match.
8503 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
8504 s->cur_prompt->prompts[2]->result)
8507 /* They don't. Silly user. */
8508 c_write_str(ssh, "Passwords do not match\r\n");
8513 * Send the new password (along with the old one).
8514 * (see above for padding rationale)
8516 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8517 ssh2_pkt_addstring(s->pktout, s->username);
8518 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8519 /* service requested */
8520 ssh2_pkt_addstring(s->pktout, "password");
8521 ssh2_pkt_addbool(s->pktout, TRUE);
8522 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8523 ssh2_pkt_addstring(s->pktout, s->password);
8524 ssh2_pkt_addstring(s->pktout,
8525 s->cur_prompt->prompts[1]->result);
8526 free_prompts(s->cur_prompt);
8527 end_log_omission(ssh, s->pktout);
8528 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8529 logevent("Sent new password");
8532 * Now see what the server has to say about it.
8533 * (If it's CHANGEREQ again, it's not happy with the
8536 crWaitUntilV(pktin);
8537 changereq_first_time = FALSE;
8542 * We need to reexamine the current pktin at the top
8543 * of the loop. Either:
8544 * - we weren't asked to change password at all, in
8545 * which case it's a SUCCESS or FAILURE with the
8547 * - we sent a new password, and the server was
8548 * either OK with it (SUCCESS or FAILURE w/partial
8549 * success) or unhappy with the _old_ password
8550 * (FAILURE w/o partial success)
8551 * In any of these cases, we go back to the top of
8552 * the loop and start again.
8557 * We don't need the old password any more, in any
8558 * case. Burn the evidence.
8560 memset(s->password, 0, strlen(s->password));
8564 char *str = dupprintf("No supported authentication methods available"
8565 " (server sent: %.*s)",
8568 ssh_disconnect(ssh, str,
8569 "No supported authentication methods available",
8570 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
8580 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
8582 /* Clear up various bits and pieces from authentication. */
8583 if (s->publickey_blob) {
8584 sfree(s->publickey_blob);
8585 sfree(s->publickey_comment);
8587 if (s->agent_response)
8588 sfree(s->agent_response);
8591 * Now the connection protocol has started, one way or another.
8594 ssh->channels = newtree234(ssh_channelcmp);
8597 * Set up handlers for some connection protocol messages, so we
8598 * don't have to handle them repeatedly in this coroutine.
8600 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
8601 ssh2_msg_channel_window_adjust;
8602 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
8603 ssh2_msg_global_request;
8606 * Create the main session channel.
8608 if (ssh->cfg.ssh_no_shell) {
8609 ssh->mainchan = NULL;
8610 } else if (*ssh->cfg.ssh_nc_host) {
8612 * Just start a direct-tcpip channel and use it as the main
8615 ssh->mainchan = snew(struct ssh_channel);
8616 ssh->mainchan->ssh = ssh;
8617 ssh2_channel_init(ssh->mainchan);
8619 "Opening direct-tcpip channel to %s:%d in place of session",
8620 ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port);
8621 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8622 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
8623 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
8624 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8625 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8626 ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host);
8627 ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port);
8629 * There's nothing meaningful to put in the originator
8630 * fields, but some servers insist on syntactically correct
8633 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
8634 ssh2_pkt_adduint32(s->pktout, 0);
8635 ssh2_pkt_send(ssh, s->pktout);
8637 crWaitUntilV(pktin);
8638 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8639 bombout(("Server refused to open a direct-tcpip channel"));
8641 /* FIXME: error data comes back in FAILURE packet */
8643 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8644 bombout(("Server's channel confirmation cited wrong channel"));
8647 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8648 ssh->mainchan->halfopen = FALSE;
8649 ssh->mainchan->type = CHAN_MAINSESSION;
8650 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8651 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8652 add234(ssh->channels, ssh->mainchan);
8653 update_specials_menu(ssh->frontend);
8654 logevent("Opened direct-tcpip channel");
8657 ssh->mainchan = snew(struct ssh_channel);
8658 ssh->mainchan->ssh = ssh;
8659 ssh2_channel_init(ssh->mainchan);
8660 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8661 ssh2_pkt_addstring(s->pktout, "session");
8662 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
8663 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8664 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8665 ssh2_pkt_send(ssh, s->pktout);
8666 crWaitUntilV(pktin);
8667 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8668 bombout(("Server refused to open a session"));
8670 /* FIXME: error data comes back in FAILURE packet */
8672 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8673 bombout(("Server's channel confirmation cited wrong channel"));
8676 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8677 ssh->mainchan->halfopen = FALSE;
8678 ssh->mainchan->type = CHAN_MAINSESSION;
8679 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8680 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8681 add234(ssh->channels, ssh->mainchan);
8682 update_specials_menu(ssh->frontend);
8683 logevent("Opened channel for session");
8684 ssh->ncmode = FALSE;
8688 * Now we have a channel, make dispatch table entries for
8689 * general channel-based messages.
8691 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8692 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8693 ssh2_msg_channel_data;
8694 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8695 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8696 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8697 ssh2_msg_channel_open_confirmation;
8698 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8699 ssh2_msg_channel_open_failure;
8700 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8701 ssh2_msg_channel_request;
8702 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8703 ssh2_msg_channel_open;
8705 if (ssh->mainchan && ssh->cfg.ssh_simple) {
8707 * This message indicates to the server that we promise
8708 * not to try to run any other channel in parallel with
8709 * this one, so it's safe for it to advertise a very large
8710 * window and leave the flow control to TCP.
8712 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8713 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8714 ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
8715 ssh2_pkt_addbool(s->pktout, 0); /* no reply */
8716 ssh2_pkt_send(ssh, s->pktout);
8720 * Potentially enable X11 forwarding.
8722 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward &&
8723 (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
8724 ssh->cfg.x11_auth, &ssh->cfg))) {
8725 logevent("Requesting X11 forwarding");
8726 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8727 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8728 ssh2_pkt_addstring(s->pktout, "x11-req");
8729 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8730 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8731 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname);
8733 * Note that while we blank the X authentication data here, we don't
8734 * take any special action to blank the start of an X11 channel,
8735 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
8736 * without having session blanking enabled is likely to leak your
8737 * cookie into the log.
8739 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8740 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring);
8741 end_log_omission(ssh, s->pktout);
8742 ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum);
8743 ssh2_pkt_send(ssh, s->pktout);
8745 crWaitUntilV(pktin);
8747 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8748 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8749 bombout(("Unexpected response to X11 forwarding request:"
8750 " packet type %d", pktin->type));
8753 logevent("X11 forwarding refused");
8755 logevent("X11 forwarding enabled");
8756 ssh->X11_fwd_enabled = TRUE;
8761 * Enable port forwardings.
8763 ssh_setup_portfwd(ssh, &ssh->cfg);
8766 * Potentially enable agent forwarding.
8768 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) {
8769 logevent("Requesting OpenSSH-style agent forwarding");
8770 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8771 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8772 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
8773 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8774 ssh2_pkt_send(ssh, s->pktout);
8776 crWaitUntilV(pktin);
8778 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8779 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8780 bombout(("Unexpected response to agent forwarding request:"
8781 " packet type %d", pktin->type));
8784 logevent("Agent forwarding refused");
8786 logevent("Agent forwarding enabled");
8787 ssh->agentfwd_enabled = TRUE;
8792 * Now allocate a pty for the session.
8794 if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) {
8795 /* Unpick the terminal-speed string. */
8796 /* XXX perhaps we should allow no speeds to be sent. */
8797 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8798 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
8799 /* Build the pty request. */
8800 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8801 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8802 ssh2_pkt_addstring(s->pktout, "pty-req");
8803 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8804 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
8805 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
8806 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
8807 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
8808 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
8809 ssh2_pkt_addstring_start(s->pktout);
8810 parse_ttymodes(ssh, ssh->cfg.ttymodes,
8811 ssh2_send_ttymode, (void *)s->pktout);
8812 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
8813 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
8814 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
8815 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
8816 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
8817 ssh2_pkt_send(ssh, s->pktout);
8818 ssh->state = SSH_STATE_INTERMED;
8820 crWaitUntilV(pktin);
8822 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8823 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8824 bombout(("Unexpected response to pty request:"
8825 " packet type %d", pktin->type));
8828 c_write_str(ssh, "Server refused to allocate pty\r\n");
8829 ssh->editing = ssh->echoing = 1;
8831 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8832 ssh->ospeed, ssh->ispeed);
8835 ssh->editing = ssh->echoing = 1;
8839 * Send environment variables.
8841 * Simplest thing here is to send all the requests at once, and
8842 * then wait for a whole bunch of successes or failures.
8844 if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) {
8845 char *e = ssh->cfg.environmt;
8846 char *var, *varend, *val;
8852 while (*e && *e != '\t') e++;
8854 if (*e == '\t') e++;
8859 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8860 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8861 ssh2_pkt_addstring(s->pktout, "env");
8862 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8863 ssh2_pkt_addstring_start(s->pktout);
8864 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
8865 ssh2_pkt_addstring(s->pktout, val);
8866 ssh2_pkt_send(ssh, s->pktout);
8871 logeventf(ssh, "Sent %d environment variables", s->num_env);
8874 s->env_left = s->num_env;
8876 while (s->env_left > 0) {
8877 crWaitUntilV(pktin);
8879 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8880 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8881 bombout(("Unexpected response to environment request:"
8882 " packet type %d", pktin->type));
8892 if (s->env_ok == s->num_env) {
8893 logevent("All environment variables successfully set");
8894 } else if (s->env_ok == 0) {
8895 logevent("All environment variables refused");
8896 c_write_str(ssh, "Server refused to set environment variables\r\n");
8898 logeventf(ssh, "%d environment variables refused",
8899 s->num_env - s->env_ok);
8900 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8905 * Start a shell or a remote command. We may have to attempt
8906 * this twice if the config data has provided a second choice
8909 if (ssh->mainchan && !ssh->ncmode) while (1) {
8913 if (ssh->fallback_cmd) {
8914 subsys = ssh->cfg.ssh_subsys2;
8915 cmd = ssh->cfg.remote_cmd_ptr2;
8917 subsys = ssh->cfg.ssh_subsys;
8918 cmd = ssh->cfg.remote_cmd_ptr;
8919 if (!cmd) cmd = ssh->cfg.remote_cmd;
8922 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8923 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8925 ssh2_pkt_addstring(s->pktout, "subsystem");
8926 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8927 ssh2_pkt_addstring(s->pktout, cmd);
8929 ssh2_pkt_addstring(s->pktout, "exec");
8930 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8931 ssh2_pkt_addstring(s->pktout, cmd);
8933 ssh2_pkt_addstring(s->pktout, "shell");
8934 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8936 ssh2_pkt_send(ssh, s->pktout);
8938 crWaitUntilV(pktin);
8940 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8941 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8942 bombout(("Unexpected response to shell/command request:"
8943 " packet type %d", pktin->type));
8947 * We failed to start the command. If this is the
8948 * fallback command, we really are finished; if it's
8949 * not, and if the fallback command exists, try falling
8950 * back to it before complaining.
8952 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
8953 logevent("Primary command failed; attempting fallback");
8954 ssh->fallback_cmd = TRUE;
8957 bombout(("Server refused to start a shell/command"));
8960 logevent("Started a shell/command");
8965 ssh->state = SSH_STATE_SESSION;
8966 if (ssh->size_needed)
8967 ssh_size(ssh, ssh->term_width, ssh->term_height);
8968 if (ssh->eof_needed)
8969 ssh_special(ssh, TS_EOF);
8972 * All the initial channel requests are done, so install the default
8975 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success;
8976 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure;
8982 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
8987 s->try_send = FALSE;
8991 * _All_ the connection-layer packets we expect to
8992 * receive are now handled by the dispatch table.
8993 * Anything that reaches here must be bogus.
8996 bombout(("Strange packet received: type %d", pktin->type));
8998 } else if (ssh->mainchan) {
9000 * We have spare data. Add it to the channel buffer.
9002 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
9007 struct ssh_channel *c;
9009 * Try to send data on all channels if we can.
9011 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
9012 ssh2_try_send_and_unthrottle(ssh, c);
9020 * Handlers for SSH-2 messages that might arrive at any moment.
9022 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
9024 /* log reason code in disconnect message */
9028 reason = ssh_pkt_getuint32(pktin);
9029 ssh_pkt_getstring(pktin, &msg, &msglen);
9031 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9032 buf = dupprintf("Received disconnect message (%s)",
9033 ssh2_disconnect_reasons[reason]);
9035 buf = dupprintf("Received disconnect message (unknown"
9036 " type %d)", reason);
9040 buf = dupprintf("Disconnection message text: %.*s",
9043 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9045 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9046 ssh2_disconnect_reasons[reason] : "unknown",
9051 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
9053 /* log the debug message */
9058 /* XXX maybe we should actually take notice of this */
9059 always_display = ssh2_pkt_getbool(pktin);
9060 ssh_pkt_getstring(pktin, &msg, &msglen);
9062 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
9065 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
9067 struct Packet *pktout;
9068 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9069 ssh2_pkt_adduint32(pktout, pktin->sequence);
9071 * UNIMPLEMENTED messages MUST appear in the same order as the
9072 * messages they respond to. Hence, never queue them.
9074 ssh2_pkt_send_noqueue(ssh, pktout);
9078 * Handle the top-level SSH-2 protocol.
9080 static void ssh2_protocol_setup(Ssh ssh)
9085 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9087 for (i = 0; i < 256; i++)
9088 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9091 * Any message we actually understand, we set to NULL so that
9092 * the coroutines will get it.
9094 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
9095 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
9096 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
9097 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
9098 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
9099 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
9100 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
9101 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
9102 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
9103 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
9104 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
9105 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
9106 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
9107 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
9108 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9109 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
9110 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
9111 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
9112 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
9113 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
9114 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
9115 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
9116 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
9117 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
9118 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
9119 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
9120 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
9121 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
9122 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
9123 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
9124 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
9125 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
9126 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
9129 * These special message types we install handlers for.
9131 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
9132 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
9133 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9136 static void ssh2_timer(void *ctx, long now)
9140 if (ssh->state == SSH_STATE_CLOSED)
9143 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9144 now - ssh->next_rekey >= 0) {
9145 do_ssh2_transport(ssh, "timeout", -1, NULL);
9149 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
9150 struct Packet *pktin)
9152 unsigned char *in = (unsigned char *)vin;
9153 if (ssh->state == SSH_STATE_CLOSED)
9157 ssh->incoming_data_size += pktin->encrypted_len;
9158 if (!ssh->kex_in_progress &&
9159 ssh->max_data_size != 0 &&
9160 ssh->incoming_data_size > ssh->max_data_size)
9161 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9164 if (pktin && ssh->packet_dispatch[pktin->type]) {
9165 ssh->packet_dispatch[pktin->type](ssh, pktin);
9169 if (!ssh->protocol_initial_phase_done ||
9170 (pktin && pktin->type >= 20 && pktin->type < 50)) {
9171 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
9172 !ssh->protocol_initial_phase_done) {
9173 ssh->protocol_initial_phase_done = TRUE;
9175 * Allow authconn to initialise itself.
9177 do_ssh2_authconn(ssh, NULL, 0, NULL);
9180 do_ssh2_authconn(ssh, in, inlen, pktin);
9185 * Called to set up the connection.
9187 * Returns an error message, or NULL on success.
9189 static const char *ssh_init(void *frontend_handle, void **backend_handle,
9191 char *host, int port, char **realhost, int nodelay,
9197 ssh = snew(struct ssh_tag);
9198 ssh->cfg = *cfg; /* STRUCTURE COPY */
9199 ssh->version = 0; /* when not ready yet */
9202 ssh->v1_cipher_ctx = NULL;
9203 ssh->crcda_ctx = NULL;
9204 ssh->cscipher = NULL;
9205 ssh->cs_cipher_ctx = NULL;
9206 ssh->sccipher = NULL;
9207 ssh->sc_cipher_ctx = NULL;
9209 ssh->cs_mac_ctx = NULL;
9211 ssh->sc_mac_ctx = NULL;
9213 ssh->cs_comp_ctx = NULL;
9215 ssh->sc_comp_ctx = NULL;
9217 ssh->kex_ctx = NULL;
9218 ssh->hostkey = NULL;
9220 ssh->close_expected = FALSE;
9221 ssh->clean_exit = FALSE;
9222 ssh->state = SSH_STATE_PREPACKET;
9223 ssh->size_needed = FALSE;
9224 ssh->eof_needed = FALSE;
9227 ssh->deferred_send_data = NULL;
9228 ssh->deferred_len = 0;
9229 ssh->deferred_size = 0;
9230 ssh->fallback_cmd = 0;
9231 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9232 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9233 ssh->x11disp = NULL;
9234 ssh->v1_compressing = FALSE;
9235 ssh->v2_outgoing_sequence = 0;
9236 ssh->ssh1_rdpkt_crstate = 0;
9237 ssh->ssh2_rdpkt_crstate = 0;
9238 ssh->do_ssh_init_crstate = 0;
9239 ssh->ssh_gotdata_crstate = 0;
9240 ssh->do_ssh1_connection_crstate = 0;
9241 ssh->do_ssh1_login_crstate = 0;
9242 ssh->do_ssh2_transport_crstate = 0;
9243 ssh->do_ssh2_authconn_crstate = 0;
9244 ssh->do_ssh_init_state = NULL;
9245 ssh->do_ssh1_login_state = NULL;
9246 ssh->do_ssh2_transport_state = NULL;
9247 ssh->do_ssh2_authconn_state = NULL;
9250 ssh->mainchan = NULL;
9251 ssh->throttled_all = 0;
9252 ssh->v1_stdout_throttling = 0;
9254 ssh->queuelen = ssh->queuesize = 0;
9255 ssh->queueing = FALSE;
9256 ssh->qhead = ssh->qtail = NULL;
9257 ssh->deferred_rekey_reason = NULL;
9258 bufchain_init(&ssh->queued_incoming_data);
9259 ssh->frozen = FALSE;
9261 *backend_handle = ssh;
9264 if (crypto_startup() == 0)
9265 return "Microsoft high encryption pack not installed!";
9268 ssh->frontend = frontend_handle;
9269 ssh->term_width = ssh->cfg.width;
9270 ssh->term_height = ssh->cfg.height;
9272 ssh->channels = NULL;
9273 ssh->rportfwds = NULL;
9274 ssh->portfwds = NULL;
9279 ssh->conn_throttle_count = 0;
9280 ssh->overall_bufsize = 0;
9281 ssh->fallback_cmd = 0;
9283 ssh->protocol = NULL;
9285 ssh->protocol_initial_phase_done = FALSE;
9289 ssh->incoming_data_size = ssh->outgoing_data_size =
9290 ssh->deferred_data_size = 0L;
9291 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9292 ssh->kex_in_progress = FALSE;
9295 ssh->gsslibs = NULL;
9298 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
9307 static void ssh_free(void *handle)
9309 Ssh ssh = (Ssh) handle;
9310 struct ssh_channel *c;
9311 struct ssh_rportfwd *pf;
9313 if (ssh->v1_cipher_ctx)
9314 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9315 if (ssh->cs_cipher_ctx)
9316 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9317 if (ssh->sc_cipher_ctx)
9318 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9319 if (ssh->cs_mac_ctx)
9320 ssh->csmac->free_context(ssh->cs_mac_ctx);
9321 if (ssh->sc_mac_ctx)
9322 ssh->scmac->free_context(ssh->sc_mac_ctx);
9323 if (ssh->cs_comp_ctx) {
9325 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9327 zlib_compress_cleanup(ssh->cs_comp_ctx);
9329 if (ssh->sc_comp_ctx) {
9331 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9333 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9336 dh_cleanup(ssh->kex_ctx);
9337 sfree(ssh->savedhost);
9339 while (ssh->queuelen-- > 0)
9340 ssh_free_packet(ssh->queue[ssh->queuelen]);
9343 while (ssh->qhead) {
9344 struct queued_handler *qh = ssh->qhead;
9345 ssh->qhead = qh->next;
9348 ssh->qhead = ssh->qtail = NULL;
9350 if (ssh->channels) {
9351 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9354 if (c->u.x11.s != NULL)
9355 x11_close(c->u.x11.s);
9358 if (c->u.pfd.s != NULL)
9359 pfd_close(c->u.pfd.s);
9364 freetree234(ssh->channels);
9365 ssh->channels = NULL;
9368 if (ssh->rportfwds) {
9369 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
9371 freetree234(ssh->rportfwds);
9372 ssh->rportfwds = NULL;
9374 sfree(ssh->deferred_send_data);
9376 x11_free_display(ssh->x11disp);
9377 sfree(ssh->do_ssh_init_state);
9378 sfree(ssh->do_ssh1_login_state);
9379 sfree(ssh->do_ssh2_transport_state);
9380 sfree(ssh->do_ssh2_authconn_state);
9383 sfree(ssh->fullhostname);
9384 if (ssh->crcda_ctx) {
9385 crcda_free_context(ssh->crcda_ctx);
9386 ssh->crcda_ctx = NULL;
9389 ssh_do_close(ssh, TRUE);
9390 expire_timer_context(ssh);
9392 pinger_free(ssh->pinger);
9393 bufchain_clear(&ssh->queued_incoming_data);
9396 ssh_gss_cleanup(ssh->gsslibs);
9404 * Reconfigure the SSH backend.
9406 static void ssh_reconfig(void *handle, Config *cfg)
9408 Ssh ssh = (Ssh) handle;
9409 char *rekeying = NULL, rekey_mandatory = FALSE;
9410 unsigned long old_max_data_size;
9412 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
9414 ssh_setup_portfwd(ssh, cfg);
9416 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
9417 cfg->ssh_rekey_time != 0) {
9418 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
9419 long now = GETTICKCOUNT();
9421 if (new_next - now < 0) {
9422 rekeying = "timeout shortened";
9424 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9428 old_max_data_size = ssh->max_data_size;
9429 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
9430 if (old_max_data_size != ssh->max_data_size &&
9431 ssh->max_data_size != 0) {
9432 if (ssh->outgoing_data_size > ssh->max_data_size ||
9433 ssh->incoming_data_size > ssh->max_data_size)
9434 rekeying = "data limit lowered";
9437 if (ssh->cfg.compression != cfg->compression) {
9438 rekeying = "compression setting changed";
9439 rekey_mandatory = TRUE;
9442 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
9443 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
9444 sizeof(ssh->cfg.ssh_cipherlist))) {
9445 rekeying = "cipher settings changed";
9446 rekey_mandatory = TRUE;
9449 ssh->cfg = *cfg; /* STRUCTURE COPY */
9452 if (!ssh->kex_in_progress) {
9453 do_ssh2_transport(ssh, rekeying, -1, NULL);
9454 } else if (rekey_mandatory) {
9455 ssh->deferred_rekey_reason = rekeying;
9461 * Called to send data down the SSH connection.
9463 static int ssh_send(void *handle, char *buf, int len)
9465 Ssh ssh = (Ssh) handle;
9467 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
9470 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
9472 return ssh_sendbuffer(ssh);
9476 * Called to query the current amount of buffered stdin data.
9478 static int ssh_sendbuffer(void *handle)
9480 Ssh ssh = (Ssh) handle;
9483 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
9487 * If the SSH socket itself has backed up, add the total backup
9488 * size on that to any individual buffer on the stdin channel.
9491 if (ssh->throttled_all)
9492 override_value = ssh->overall_bufsize;
9494 if (ssh->version == 1) {
9495 return override_value;
9496 } else if (ssh->version == 2) {
9497 if (!ssh->mainchan || ssh->mainchan->closes > 0)
9498 return override_value;
9500 return (override_value +
9501 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
9508 * Called to set the size of the window from SSH's POV.
9510 static void ssh_size(void *handle, int width, int height)
9512 Ssh ssh = (Ssh) handle;
9513 struct Packet *pktout;
9515 ssh->term_width = width;
9516 ssh->term_height = height;
9518 switch (ssh->state) {
9519 case SSH_STATE_BEFORE_SIZE:
9520 case SSH_STATE_PREPACKET:
9521 case SSH_STATE_CLOSED:
9522 break; /* do nothing */
9523 case SSH_STATE_INTERMED:
9524 ssh->size_needed = TRUE; /* buffer for later */
9526 case SSH_STATE_SESSION:
9527 if (!ssh->cfg.nopty) {
9528 if (ssh->version == 1) {
9529 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
9530 PKT_INT, ssh->term_height,
9531 PKT_INT, ssh->term_width,
9532 PKT_INT, 0, PKT_INT, 0, PKT_END);
9533 } else if (ssh->mainchan) {
9534 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9535 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9536 ssh2_pkt_addstring(pktout, "window-change");
9537 ssh2_pkt_addbool(pktout, 0);
9538 ssh2_pkt_adduint32(pktout, ssh->term_width);
9539 ssh2_pkt_adduint32(pktout, ssh->term_height);
9540 ssh2_pkt_adduint32(pktout, 0);
9541 ssh2_pkt_adduint32(pktout, 0);
9542 ssh2_pkt_send(ssh, pktout);
9550 * Return a list of the special codes that make sense in this
9553 static const struct telnet_special *ssh_get_specials(void *handle)
9555 static const struct telnet_special ssh1_ignore_special[] = {
9556 {"IGNORE message", TS_NOP}
9558 static const struct telnet_special ssh2_ignore_special[] = {
9559 {"IGNORE message", TS_NOP},
9561 static const struct telnet_special ssh2_rekey_special[] = {
9562 {"Repeat key exchange", TS_REKEY},
9564 static const struct telnet_special ssh2_session_specials[] = {
9567 /* These are the signal names defined by RFC 4254.
9568 * They include all the ISO C signals, but are a subset of the POSIX
9569 * required signals. */
9570 {"SIGINT (Interrupt)", TS_SIGINT},
9571 {"SIGTERM (Terminate)", TS_SIGTERM},
9572 {"SIGKILL (Kill)", TS_SIGKILL},
9573 {"SIGQUIT (Quit)", TS_SIGQUIT},
9574 {"SIGHUP (Hangup)", TS_SIGHUP},
9575 {"More signals", TS_SUBMENU},
9576 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
9577 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
9578 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
9579 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
9582 static const struct telnet_special specials_end[] = {
9585 /* XXX review this length for any changes: */
9586 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
9587 lenof(ssh2_rekey_special) +
9588 lenof(ssh2_session_specials) +
9589 lenof(specials_end)];
9590 Ssh ssh = (Ssh) handle;
9592 #define ADD_SPECIALS(name) \
9594 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9595 memcpy(&ssh_specials[i], name, sizeof name); \
9599 if (ssh->version == 1) {
9600 /* Don't bother offering IGNORE if we've decided the remote
9601 * won't cope with it, since we wouldn't bother sending it if
9603 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9604 ADD_SPECIALS(ssh1_ignore_special);
9605 } else if (ssh->version == 2) {
9606 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
9607 ADD_SPECIALS(ssh2_ignore_special);
9608 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
9609 ADD_SPECIALS(ssh2_rekey_special);
9611 ADD_SPECIALS(ssh2_session_specials);
9612 } /* else we're not ready yet */
9615 ADD_SPECIALS(specials_end);
9616 return ssh_specials;
9624 * Send special codes. TS_EOF is useful for `plink', so you
9625 * can send an EOF and collect resulting output (e.g. `plink
9628 static void ssh_special(void *handle, Telnet_Special code)
9630 Ssh ssh = (Ssh) handle;
9631 struct Packet *pktout;
9633 if (code == TS_EOF) {
9634 if (ssh->state != SSH_STATE_SESSION) {
9636 * Buffer the EOF in case we are pre-SESSION, so we can
9637 * send it as soon as we reach SESSION.
9640 ssh->eof_needed = TRUE;
9643 if (ssh->version == 1) {
9644 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
9645 } else if (ssh->mainchan) {
9646 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
9647 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9648 ssh2_pkt_send(ssh, pktout);
9649 ssh->send_ok = 0; /* now stop trying to read from stdin */
9651 logevent("Sent EOF message");
9652 } else if (code == TS_PING || code == TS_NOP) {
9653 if (ssh->state == SSH_STATE_CLOSED
9654 || ssh->state == SSH_STATE_PREPACKET) return;
9655 if (ssh->version == 1) {
9656 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9657 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
9659 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
9660 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
9661 ssh2_pkt_addstring_start(pktout);
9662 ssh2_pkt_send_noqueue(ssh, pktout);
9665 } else if (code == TS_REKEY) {
9666 if (!ssh->kex_in_progress && ssh->version == 2) {
9667 do_ssh2_transport(ssh, "at user request", -1, NULL);
9669 } else if (code == TS_BRK) {
9670 if (ssh->state == SSH_STATE_CLOSED
9671 || ssh->state == SSH_STATE_PREPACKET) return;
9672 if (ssh->version == 1) {
9673 logevent("Unable to send BREAK signal in SSH-1");
9674 } else if (ssh->mainchan) {
9675 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9676 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9677 ssh2_pkt_addstring(pktout, "break");
9678 ssh2_pkt_addbool(pktout, 0);
9679 ssh2_pkt_adduint32(pktout, 0); /* default break length */
9680 ssh2_pkt_send(ssh, pktout);
9683 /* Is is a POSIX signal? */
9684 char *signame = NULL;
9685 if (code == TS_SIGABRT) signame = "ABRT";
9686 if (code == TS_SIGALRM) signame = "ALRM";
9687 if (code == TS_SIGFPE) signame = "FPE";
9688 if (code == TS_SIGHUP) signame = "HUP";
9689 if (code == TS_SIGILL) signame = "ILL";
9690 if (code == TS_SIGINT) signame = "INT";
9691 if (code == TS_SIGKILL) signame = "KILL";
9692 if (code == TS_SIGPIPE) signame = "PIPE";
9693 if (code == TS_SIGQUIT) signame = "QUIT";
9694 if (code == TS_SIGSEGV) signame = "SEGV";
9695 if (code == TS_SIGTERM) signame = "TERM";
9696 if (code == TS_SIGUSR1) signame = "USR1";
9697 if (code == TS_SIGUSR2) signame = "USR2";
9698 /* The SSH-2 protocol does in principle support arbitrary named
9699 * signals, including signame@domain, but we don't support those. */
9701 /* It's a signal. */
9702 if (ssh->version == 2 && ssh->mainchan) {
9703 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9704 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9705 ssh2_pkt_addstring(pktout, "signal");
9706 ssh2_pkt_addbool(pktout, 0);
9707 ssh2_pkt_addstring(pktout, signame);
9708 ssh2_pkt_send(ssh, pktout);
9709 logeventf(ssh, "Sent signal SIG%s", signame);
9712 /* Never heard of it. Do nothing */
9717 void *new_sock_channel(void *handle, Socket s)
9719 Ssh ssh = (Ssh) handle;
9720 struct ssh_channel *c;
9721 c = snew(struct ssh_channel);
9724 ssh2_channel_init(c);
9726 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
9728 add234(ssh->channels, c);
9733 * This is called when stdout/stderr (the entity to which
9734 * from_backend sends data) manages to clear some backlog.
9736 static void ssh_unthrottle(void *handle, int bufsize)
9738 Ssh ssh = (Ssh) handle;
9741 if (ssh->version == 1) {
9742 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
9743 ssh->v1_stdout_throttling = 0;
9744 ssh_throttle_conn(ssh, -1);
9747 if (ssh->mainchan) {
9748 ssh2_set_window(ssh->mainchan,
9749 bufsize < ssh->mainchan->v.v2.locmaxwin ?
9750 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
9751 if (ssh->cfg.ssh_simple)
9754 buflimit = ssh->mainchan->v.v2.locmaxwin;
9755 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
9756 ssh->mainchan->throttling_conn = 0;
9757 ssh_throttle_conn(ssh, -1);
9763 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
9765 struct ssh_channel *c = (struct ssh_channel *)channel;
9767 struct Packet *pktout;
9769 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
9771 if (ssh->version == 1) {
9772 send_packet(ssh, SSH1_MSG_PORT_OPEN,
9773 PKT_INT, c->localid,
9776 /* PKT_STR, <org:orgport>, */
9779 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
9780 ssh2_pkt_addstring(pktout, "direct-tcpip");
9781 ssh2_pkt_adduint32(pktout, c->localid);
9782 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
9783 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
9784 ssh2_pkt_addstring(pktout, hostname);
9785 ssh2_pkt_adduint32(pktout, port);
9787 * We make up values for the originator data; partly it's
9788 * too much hassle to keep track, and partly I'm not
9789 * convinced the server should be told details like that
9790 * about my local network configuration.
9791 * The "originator IP address" is syntactically a numeric
9792 * IP address, and some servers (e.g., Tectia) get upset
9793 * if it doesn't match this syntax.
9795 ssh2_pkt_addstring(pktout, "0.0.0.0");
9796 ssh2_pkt_adduint32(pktout, 0);
9797 ssh2_pkt_send(ssh, pktout);
9801 static int ssh_connected(void *handle)
9803 Ssh ssh = (Ssh) handle;
9804 return ssh->s != NULL;
9807 static int ssh_sendok(void *handle)
9809 Ssh ssh = (Ssh) handle;
9810 return ssh->send_ok;
9813 static int ssh_ldisc(void *handle, int option)
9815 Ssh ssh = (Ssh) handle;
9816 if (option == LD_ECHO)
9817 return ssh->echoing;
9818 if (option == LD_EDIT)
9819 return ssh->editing;
9823 static void ssh_provide_ldisc(void *handle, void *ldisc)
9825 Ssh ssh = (Ssh) handle;
9829 static void ssh_provide_logctx(void *handle, void *logctx)
9831 Ssh ssh = (Ssh) handle;
9832 ssh->logctx = logctx;
9835 static int ssh_return_exitcode(void *handle)
9837 Ssh ssh = (Ssh) handle;
9841 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
9845 * cfg_info for SSH is the currently running version of the
9846 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
9848 static int ssh_cfg_info(void *handle)
9850 Ssh ssh = (Ssh) handle;
9851 return ssh->version;
9855 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
9856 * that fails. This variable is the means by which scp.c can reach
9857 * into the SSH code and find out which one it got.
9859 extern int ssh_fallback_cmd(void *handle)
9861 Ssh ssh = (Ssh) handle;
9862 return ssh->fallback_cmd;
9865 Backend ssh_backend = {
9875 ssh_return_exitcode,