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
199 #define BUG_CHOKES_ON_WINADJ 1024
202 * Codes for terminal modes.
203 * Most of these are the same in SSH-1 and SSH-2.
204 * This list is derived from RFC 4254 and
207 static const struct {
208 const char* const mode;
210 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
212 /* "V" prefix discarded for special characters relative to SSH specs */
213 { "INTR", 1, TTY_OP_CHAR },
214 { "QUIT", 2, TTY_OP_CHAR },
215 { "ERASE", 3, TTY_OP_CHAR },
216 { "KILL", 4, TTY_OP_CHAR },
217 { "EOF", 5, TTY_OP_CHAR },
218 { "EOL", 6, TTY_OP_CHAR },
219 { "EOL2", 7, TTY_OP_CHAR },
220 { "START", 8, TTY_OP_CHAR },
221 { "STOP", 9, TTY_OP_CHAR },
222 { "SUSP", 10, TTY_OP_CHAR },
223 { "DSUSP", 11, TTY_OP_CHAR },
224 { "REPRINT", 12, TTY_OP_CHAR },
225 { "WERASE", 13, TTY_OP_CHAR },
226 { "LNEXT", 14, TTY_OP_CHAR },
227 { "FLUSH", 15, TTY_OP_CHAR },
228 { "SWTCH", 16, TTY_OP_CHAR },
229 { "STATUS", 17, TTY_OP_CHAR },
230 { "DISCARD", 18, TTY_OP_CHAR },
231 { "IGNPAR", 30, TTY_OP_BOOL },
232 { "PARMRK", 31, TTY_OP_BOOL },
233 { "INPCK", 32, TTY_OP_BOOL },
234 { "ISTRIP", 33, TTY_OP_BOOL },
235 { "INLCR", 34, TTY_OP_BOOL },
236 { "IGNCR", 35, TTY_OP_BOOL },
237 { "ICRNL", 36, TTY_OP_BOOL },
238 { "IUCLC", 37, TTY_OP_BOOL },
239 { "IXON", 38, TTY_OP_BOOL },
240 { "IXANY", 39, TTY_OP_BOOL },
241 { "IXOFF", 40, TTY_OP_BOOL },
242 { "IMAXBEL", 41, TTY_OP_BOOL },
243 { "ISIG", 50, TTY_OP_BOOL },
244 { "ICANON", 51, TTY_OP_BOOL },
245 { "XCASE", 52, TTY_OP_BOOL },
246 { "ECHO", 53, TTY_OP_BOOL },
247 { "ECHOE", 54, TTY_OP_BOOL },
248 { "ECHOK", 55, TTY_OP_BOOL },
249 { "ECHONL", 56, TTY_OP_BOOL },
250 { "NOFLSH", 57, TTY_OP_BOOL },
251 { "TOSTOP", 58, TTY_OP_BOOL },
252 { "IEXTEN", 59, TTY_OP_BOOL },
253 { "ECHOCTL", 60, TTY_OP_BOOL },
254 { "ECHOKE", 61, TTY_OP_BOOL },
255 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
256 { "OPOST", 70, TTY_OP_BOOL },
257 { "OLCUC", 71, TTY_OP_BOOL },
258 { "ONLCR", 72, TTY_OP_BOOL },
259 { "OCRNL", 73, TTY_OP_BOOL },
260 { "ONOCR", 74, TTY_OP_BOOL },
261 { "ONLRET", 75, TTY_OP_BOOL },
262 { "CS7", 90, TTY_OP_BOOL },
263 { "CS8", 91, TTY_OP_BOOL },
264 { "PARENB", 92, TTY_OP_BOOL },
265 { "PARODD", 93, TTY_OP_BOOL }
268 /* Miscellaneous other tty-related constants. */
269 #define SSH_TTY_OP_END 0
270 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
271 #define SSH1_TTY_OP_ISPEED 192
272 #define SSH1_TTY_OP_OSPEED 193
273 #define SSH2_TTY_OP_ISPEED 128
274 #define SSH2_TTY_OP_OSPEED 129
276 /* Helper functions for parsing tty-related config. */
277 static unsigned int ssh_tty_parse_specchar(char *s)
282 ret = ctrlparse(s, &next);
283 if (!next) ret = s[0];
285 ret = 255; /* special value meaning "don't set" */
289 static unsigned int ssh_tty_parse_boolean(char *s)
291 if (stricmp(s, "yes") == 0 ||
292 stricmp(s, "on") == 0 ||
293 stricmp(s, "true") == 0 ||
294 stricmp(s, "+") == 0)
296 else if (stricmp(s, "no") == 0 ||
297 stricmp(s, "off") == 0 ||
298 stricmp(s, "false") == 0 ||
299 stricmp(s, "-") == 0)
300 return 0; /* false */
302 return (atoi(s) != 0);
305 #define translate(x) if (type == x) return #x
306 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
307 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
308 static char *ssh1_pkt_type(int type)
310 translate(SSH1_MSG_DISCONNECT);
311 translate(SSH1_SMSG_PUBLIC_KEY);
312 translate(SSH1_CMSG_SESSION_KEY);
313 translate(SSH1_CMSG_USER);
314 translate(SSH1_CMSG_AUTH_RSA);
315 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
316 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
317 translate(SSH1_CMSG_AUTH_PASSWORD);
318 translate(SSH1_CMSG_REQUEST_PTY);
319 translate(SSH1_CMSG_WINDOW_SIZE);
320 translate(SSH1_CMSG_EXEC_SHELL);
321 translate(SSH1_CMSG_EXEC_CMD);
322 translate(SSH1_SMSG_SUCCESS);
323 translate(SSH1_SMSG_FAILURE);
324 translate(SSH1_CMSG_STDIN_DATA);
325 translate(SSH1_SMSG_STDOUT_DATA);
326 translate(SSH1_SMSG_STDERR_DATA);
327 translate(SSH1_CMSG_EOF);
328 translate(SSH1_SMSG_EXIT_STATUS);
329 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
330 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
331 translate(SSH1_MSG_CHANNEL_DATA);
332 translate(SSH1_MSG_CHANNEL_CLOSE);
333 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
334 translate(SSH1_SMSG_X11_OPEN);
335 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
336 translate(SSH1_MSG_PORT_OPEN);
337 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
338 translate(SSH1_SMSG_AGENT_OPEN);
339 translate(SSH1_MSG_IGNORE);
340 translate(SSH1_CMSG_EXIT_CONFIRMATION);
341 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
342 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
343 translate(SSH1_MSG_DEBUG);
344 translate(SSH1_CMSG_REQUEST_COMPRESSION);
345 translate(SSH1_CMSG_AUTH_TIS);
346 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
347 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
348 translate(SSH1_CMSG_AUTH_CCARD);
349 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
350 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
353 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
355 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
356 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
357 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
358 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
359 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
360 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
361 translate(SSH2_MSG_DISCONNECT);
362 translate(SSH2_MSG_IGNORE);
363 translate(SSH2_MSG_UNIMPLEMENTED);
364 translate(SSH2_MSG_DEBUG);
365 translate(SSH2_MSG_SERVICE_REQUEST);
366 translate(SSH2_MSG_SERVICE_ACCEPT);
367 translate(SSH2_MSG_KEXINIT);
368 translate(SSH2_MSG_NEWKEYS);
369 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
370 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
371 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
372 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
373 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
374 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
375 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
376 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
377 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
378 translate(SSH2_MSG_USERAUTH_REQUEST);
379 translate(SSH2_MSG_USERAUTH_FAILURE);
380 translate(SSH2_MSG_USERAUTH_SUCCESS);
381 translate(SSH2_MSG_USERAUTH_BANNER);
382 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
383 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
384 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
385 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
386 translate(SSH2_MSG_GLOBAL_REQUEST);
387 translate(SSH2_MSG_REQUEST_SUCCESS);
388 translate(SSH2_MSG_REQUEST_FAILURE);
389 translate(SSH2_MSG_CHANNEL_OPEN);
390 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
391 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
392 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
393 translate(SSH2_MSG_CHANNEL_DATA);
394 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
395 translate(SSH2_MSG_CHANNEL_EOF);
396 translate(SSH2_MSG_CHANNEL_CLOSE);
397 translate(SSH2_MSG_CHANNEL_REQUEST);
398 translate(SSH2_MSG_CHANNEL_SUCCESS);
399 translate(SSH2_MSG_CHANNEL_FAILURE);
405 /* Enumeration values for fields in SSH-1 packets */
407 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
408 /* These values are for communicating relevant semantics of
409 * fields to the packet logging code. */
410 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
414 * Coroutine mechanics for the sillier bits of the code. If these
415 * macros look impenetrable to you, you might find it helpful to
418 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
420 * which explains the theory behind these macros.
422 * In particular, if you are getting `case expression not constant'
423 * errors when building with MS Visual Studio, this is because MS's
424 * Edit and Continue debugging feature causes their compiler to
425 * violate ANSI C. To disable Edit and Continue debugging:
427 * - right-click ssh.c in the FileView
429 * - select the C/C++ tab and the General category
430 * - under `Debug info:', select anything _other_ than `Program
431 * Database for Edit and Continue'.
433 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
434 #define crBeginState crBegin(s->crLine)
435 #define crStateP(t, v) \
437 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
439 #define crState(t) crStateP(t, ssh->t)
440 #define crFinish(z) } *crLine = 0; return (z); }
441 #define crFinishV } *crLine = 0; return; }
442 #define crFinishFree(z) } sfree(s); return (z); }
443 #define crFinishFreeV } sfree(s); return; }
444 #define crReturn(z) \
446 *crLine =__LINE__; return (z); case __LINE__:;\
450 *crLine=__LINE__; return; case __LINE__:;\
452 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
453 #define crStopV do{ *crLine = 0; return; }while(0)
454 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
455 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
457 typedef struct ssh_tag *Ssh;
460 static struct Packet *ssh1_pkt_init(int pkt_type);
461 static struct Packet *ssh2_pkt_init(int pkt_type);
462 static void ssh_pkt_ensure(struct Packet *, int length);
463 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
464 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
465 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
466 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
467 static void ssh_pkt_addstring_start(struct Packet *);
468 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
469 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
470 static void ssh_pkt_addstring(struct Packet *, const char *data);
471 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
472 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
473 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
474 static int ssh2_pkt_construct(Ssh, struct Packet *);
475 static void ssh2_pkt_send(Ssh, struct Packet *);
476 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
477 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
478 struct Packet *pktin);
479 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
480 struct Packet *pktin);
481 static void ssh2_channel_check_close(struct ssh_channel *c);
482 static void ssh_channel_destroy(struct ssh_channel *c);
485 * Buffer management constants. There are several of these for
486 * various different purposes:
488 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
489 * on a local data stream before we throttle the whole SSH
490 * connection (in SSH-1 only). Throttling the whole connection is
491 * pretty drastic so we set this high in the hope it won't
494 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
495 * on the SSH connection itself before we defensively throttle
496 * _all_ local data streams. This is pretty drastic too (though
497 * thankfully unlikely in SSH-2 since the window mechanism should
498 * ensure that the server never has any need to throttle its end
499 * of the connection), so we set this high as well.
501 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
504 * - OUR_V2_BIGWIN is the window size we advertise for the only
505 * channel in a simple connection. It must be <= INT_MAX.
507 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
508 * to the remote side. This actually has nothing to do with the
509 * size of the _packet_, but is instead a limit on the amount
510 * of data we're willing to receive in a single SSH2 channel
513 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
514 * _packet_ we're prepared to cope with. It must be a multiple
515 * of the cipher block size, and must be at least 35000.
518 #define SSH1_BUFFER_LIMIT 32768
519 #define SSH_MAX_BACKLOG 32768
520 #define OUR_V2_WINSIZE 16384
521 #define OUR_V2_BIGWIN 0x7fffffff
522 #define OUR_V2_MAXPKT 0x4000UL
523 #define OUR_V2_PACKETLIMIT 0x9000UL
525 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
527 const static struct ssh_mac *macs[] = {
528 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
530 const static struct ssh_mac *buggymacs[] = {
531 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
534 static void *ssh_comp_none_init(void)
538 static void ssh_comp_none_cleanup(void *handle)
541 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
542 unsigned char **outblock, int *outlen)
546 static int ssh_comp_none_disable(void *handle)
550 const static struct ssh_compress ssh_comp_none = {
552 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
553 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
554 ssh_comp_none_disable, NULL
556 extern const struct ssh_compress ssh_zlib;
557 const static struct ssh_compress *compressions[] = {
558 &ssh_zlib, &ssh_comp_none
561 enum { /* channel types */
566 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
568 * CHAN_ZOMBIE is used to indicate a channel for which we've
569 * already destroyed the local data source: for instance, if a
570 * forwarded port experiences a socket error on the local side, we
571 * immediately destroy its local socket and turn the SSH channel
577 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
578 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
579 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
582 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
585 struct outstanding_channel_request {
586 cchandler_fn_t handler;
588 struct outstanding_channel_request *next;
592 * 2-3-4 tree storing channels.
595 Ssh ssh; /* pointer back to main context */
596 unsigned remoteid, localid;
598 /* True if we opened this channel but server hasn't confirmed. */
601 * In SSH-1, this value contains four bits:
603 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
604 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
605 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
606 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
608 * A channel is completely finished with when all four bits are set.
610 * In SSH-2, the four bits mean:
612 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
613 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
614 * 4 We have received SSH2_MSG_CHANNEL_EOF.
615 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
617 * A channel is completely finished with when we have both sent
618 * and received CLOSE.
620 * The symbolic constants below use the SSH-2 terminology, which
621 * is a bit confusing in SSH-1, but we have to use _something_.
623 #define CLOSES_SENT_EOF 1
624 #define CLOSES_SENT_CLOSE 2
625 #define CLOSES_RCVD_EOF 4
626 #define CLOSES_RCVD_CLOSE 8
630 * This flag indicates that an EOF is pending on the outgoing side
631 * of the channel: that is, wherever we're getting the data for
632 * this channel has sent us some data followed by EOF. We can't
633 * actually send the EOF until we've finished sending the data, so
634 * we set this flag instead to remind us to do so once our buffer
640 * True if this channel is causing the underlying connection to be
645 struct ssh2_data_channel {
647 unsigned remwindow, remmaxpkt;
648 /* locwindow is signed so we can cope with excess data. */
649 int locwindow, locmaxwin;
651 * remlocwin is the amount of local window that we think
652 * the remote end had available to it after it sent the
653 * last data packet or window adjust ack.
657 * These store the list of channel requests that haven't
660 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
661 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
665 struct ssh_agent_channel {
666 unsigned char *message;
667 unsigned char msglen[4];
668 unsigned lensofar, totallen;
669 int outstanding_requests;
671 struct ssh_x11_channel {
674 struct ssh_pfd_channel {
681 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
682 * use this structure in different ways, reflecting SSH-2's
683 * altogether saner approach to port forwarding.
685 * In SSH-1, you arrange a remote forwarding by sending the server
686 * the remote port number, and the local destination host:port.
687 * When a connection comes in, the server sends you back that
688 * host:port pair, and you connect to it. This is a ready-made
689 * security hole if you're not on the ball: a malicious server
690 * could send you back _any_ host:port pair, so if you trustingly
691 * connect to the address it gives you then you've just opened the
692 * entire inside of your corporate network just by connecting
693 * through it to a dodgy SSH server. Hence, we must store a list of
694 * host:port pairs we _are_ trying to forward to, and reject a
695 * connection request from the server if it's not in the list.
697 * In SSH-2, each side of the connection minds its own business and
698 * doesn't send unnecessary information to the other. You arrange a
699 * remote forwarding by sending the server just the remote port
700 * number. When a connection comes in, the server tells you which
701 * of its ports was connected to; and _you_ have to remember what
702 * local host:port pair went with that port number.
704 * Hence, in SSH-1 this structure is indexed by destination
705 * host:port pair, whereas in SSH-2 it is indexed by source port.
707 struct ssh_portfwd; /* forward declaration */
709 struct ssh_rportfwd {
710 unsigned sport, dport;
713 struct ssh_portfwd *pfrec;
715 #define free_rportfwd(pf) ( \
716 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
719 * Separately to the rportfwd tree (which is for looking up port
720 * open requests from the server), a tree of _these_ structures is
721 * used to keep track of all the currently open port forwardings,
722 * so that we can reconfigure in mid-session if the user requests
726 enum { DESTROY, KEEP, CREATE } status;
728 unsigned sport, dport;
731 struct ssh_rportfwd *remote;
735 #define free_portfwd(pf) ( \
736 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
737 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
740 long length; /* length of `data' actually used */
741 long forcepad; /* SSH-2: force padding to at least this length */
742 int type; /* only used for incoming packets */
743 unsigned long sequence; /* SSH-2 incoming sequence number */
744 unsigned char *data; /* allocated storage */
745 unsigned char *body; /* offset of payload within `data' */
746 long savedpos; /* temporary index into `data' (for strings) */
747 long maxlen; /* amount of storage allocated for `data' */
748 long encrypted_len; /* for SSH-2 total-size counting */
751 * State associated with packet logging
755 struct logblank_t *blanks;
758 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
759 struct Packet *pktin);
760 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
761 struct Packet *pktin);
762 static void ssh1_protocol_setup(Ssh ssh);
763 static void ssh2_protocol_setup(Ssh ssh);
764 static void ssh_size(void *handle, int width, int height);
765 static void ssh_special(void *handle, Telnet_Special);
766 static int ssh2_try_send(struct ssh_channel *c);
767 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
768 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
769 static void ssh2_set_window(struct ssh_channel *c, int newwin);
770 static int ssh_sendbuffer(void *handle);
771 static int ssh_do_close(Ssh ssh, int notify_exit);
772 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
773 static int ssh2_pkt_getbool(struct Packet *pkt);
774 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
775 static void ssh2_timer(void *ctx, unsigned long now);
776 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
777 struct Packet *pktin);
778 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
780 struct rdpkt1_state_tag {
781 long len, pad, biglen, to_read;
782 unsigned long realcrc, gotcrc;
786 struct Packet *pktin;
789 struct rdpkt2_state_tag {
790 long len, pad, payload, packetlen, maclen;
793 unsigned long incoming_sequence;
794 struct Packet *pktin;
797 struct queued_handler;
798 struct queued_handler {
800 chandler_fn_t handler;
802 struct queued_handler *next;
806 const struct plug_function_table *fn;
807 /* the above field _must_ be first in the structure */
817 unsigned char session_key[32];
819 int v1_remote_protoflags;
820 int v1_local_protoflags;
821 int agentfwd_enabled;
824 const struct ssh_cipher *cipher;
827 const struct ssh2_cipher *cscipher, *sccipher;
828 void *cs_cipher_ctx, *sc_cipher_ctx;
829 const struct ssh_mac *csmac, *scmac;
830 void *cs_mac_ctx, *sc_mac_ctx;
831 const struct ssh_compress *cscomp, *sccomp;
832 void *cs_comp_ctx, *sc_comp_ctx;
833 const struct ssh_kex *kex;
834 const struct ssh_signkey *hostkey;
835 char *hostkey_str; /* string representation, for easy checking in rekeys */
836 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
837 int v2_session_id_len;
843 int echoing, editing;
847 int ospeed, ispeed; /* temporaries */
848 int term_width, term_height;
850 tree234 *channels; /* indexed by local id */
851 struct ssh_channel *mainchan; /* primary session channel */
852 int ncmode; /* is primary channel direct-tcpip? */
857 tree234 *rportfwds, *portfwds;
861 SSH_STATE_BEFORE_SIZE,
867 int size_needed, eof_needed;
868 int sent_console_eof;
869 int got_pty; /* affects EOF behaviour on main channel */
871 struct Packet **queue;
872 int queuelen, queuesize;
874 unsigned char *deferred_send_data;
875 int deferred_len, deferred_size;
878 * Gross hack: pscp will try to start SFTP but fall back to
879 * scp1 if that fails. This variable is the means by which
880 * scp.c can reach into the SSH code and find out which one it
885 bufchain banner; /* accumulates banners during do_ssh2_authconn */
890 struct X11Display *x11disp;
893 int conn_throttle_count;
896 int v1_stdout_throttling;
897 unsigned long v2_outgoing_sequence;
899 int ssh1_rdpkt_crstate;
900 int ssh2_rdpkt_crstate;
901 int ssh_gotdata_crstate;
902 int do_ssh1_connection_crstate;
904 void *do_ssh_init_state;
905 void *do_ssh1_login_state;
906 void *do_ssh2_transport_state;
907 void *do_ssh2_authconn_state;
909 struct rdpkt1_state_tag rdpkt1_state;
910 struct rdpkt2_state_tag rdpkt2_state;
912 /* SSH-1 and SSH-2 use this for different things, but both use it */
913 int protocol_initial_phase_done;
915 void (*protocol) (Ssh ssh, void *vin, int inlen,
917 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
920 * We maintain our own copy of a Conf structure here. That way,
921 * when we're passed a new one for reconfiguration, we can check
922 * the differences and potentially reconfigure port forwardings
923 * etc in mid-session.
928 * Values cached out of conf so as to avoid the tree234 lookup
929 * cost every time they're used.
934 * Dynamically allocated username string created during SSH
935 * login. Stored in here rather than in the coroutine state so
936 * that it'll be reliably freed if we shut down the SSH session
937 * at some unexpected moment.
942 * Used to transfer data back from async callbacks.
944 void *agent_response;
945 int agent_response_len;
949 * The SSH connection can be set as `frozen', meaning we are
950 * not currently accepting incoming data from the network. This
951 * is slightly more serious than setting the _socket_ as
952 * frozen, because we may already have had data passed to us
953 * from the network which we need to delay processing until
954 * after the freeze is lifted, so we also need a bufchain to
958 bufchain queued_incoming_data;
961 * Dispatch table for packet types that we may have to deal
964 handler_fn_t packet_dispatch[256];
967 * Queues of one-off handler functions for success/failure
968 * indications from a request.
970 struct queued_handler *qhead, *qtail;
971 handler_fn_t q_saved_handler1, q_saved_handler2;
974 * This module deals with sending keepalives.
979 * Track incoming and outgoing data sizes and time, for
982 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
983 unsigned long max_data_size;
985 unsigned long next_rekey, last_rekey;
986 char *deferred_rekey_reason; /* points to STATIC string; don't free */
989 * Fully qualified host name, which we need if doing GSSAPI.
995 * GSSAPI libraries for this session.
997 struct ssh_gss_liblist *gsslibs;
1001 #define logevent(s) logevent(ssh->frontend, s)
1003 /* logevent, only printf-formatted. */
1004 static void logeventf(Ssh ssh, const char *fmt, ...)
1010 buf = dupvprintf(fmt, ap);
1016 static void bomb_out(Ssh ssh, char *text)
1018 ssh_do_close(ssh, FALSE);
1020 connection_fatal(ssh->frontend, "%s", text);
1024 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1026 /* Functions to leave bits out of the SSH packet log file. */
1028 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
1030 if (conf_get_int(ssh->conf, CONF_logomitpass))
1031 pkt->logmode = blanktype;
1034 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
1036 if (ssh->logomitdata)
1037 pkt->logmode = blanktype;
1040 static void end_log_omission(Ssh ssh, struct Packet *pkt)
1042 pkt->logmode = PKTLOG_EMIT;
1045 /* Helper function for common bits of parsing ttymodes. */
1046 static void parse_ttymodes(Ssh ssh,
1047 void (*do_mode)(void *data, char *mode, char *val),
1052 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1054 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1056 * val[0] is either 'V', indicating that an explicit value
1057 * follows it, or 'A' indicating that we should pass the
1058 * value through from the local environment via get_ttymode.
1060 if (val[0] == 'A') {
1061 val = get_ttymode(ssh->frontend, key);
1063 do_mode(data, key, val);
1067 do_mode(data, key, val + 1); /* skip the 'V' */
1071 static int ssh_channelcmp(void *av, void *bv)
1073 struct ssh_channel *a = (struct ssh_channel *) av;
1074 struct ssh_channel *b = (struct ssh_channel *) bv;
1075 if (a->localid < b->localid)
1077 if (a->localid > b->localid)
1081 static int ssh_channelfind(void *av, void *bv)
1083 unsigned *a = (unsigned *) av;
1084 struct ssh_channel *b = (struct ssh_channel *) bv;
1085 if (*a < b->localid)
1087 if (*a > b->localid)
1092 static int ssh_rportcmp_ssh1(void *av, void *bv)
1094 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1095 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1097 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1098 return i < 0 ? -1 : +1;
1099 if (a->dport > b->dport)
1101 if (a->dport < b->dport)
1106 static int ssh_rportcmp_ssh2(void *av, void *bv)
1108 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1109 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1111 if (a->sport > b->sport)
1113 if (a->sport < b->sport)
1119 * Special form of strcmp which can cope with NULL inputs. NULL is
1120 * defined to sort before even the empty string.
1122 static int nullstrcmp(const char *a, const char *b)
1124 if (a == NULL && b == NULL)
1130 return strcmp(a, b);
1133 static int ssh_portcmp(void *av, void *bv)
1135 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1136 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1138 if (a->type > b->type)
1140 if (a->type < b->type)
1142 if (a->addressfamily > b->addressfamily)
1144 if (a->addressfamily < b->addressfamily)
1146 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1147 return i < 0 ? -1 : +1;
1148 if (a->sport > b->sport)
1150 if (a->sport < b->sport)
1152 if (a->type != 'D') {
1153 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1154 return i < 0 ? -1 : +1;
1155 if (a->dport > b->dport)
1157 if (a->dport < b->dport)
1163 static int alloc_channel_id(Ssh ssh)
1165 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1166 unsigned low, high, mid;
1168 struct ssh_channel *c;
1171 * First-fit allocation of channel numbers: always pick the
1172 * lowest unused one. To do this, binary-search using the
1173 * counted B-tree to find the largest channel ID which is in a
1174 * contiguous sequence from the beginning. (Precisely
1175 * everything in that sequence must have ID equal to its tree
1176 * index plus CHANNEL_NUMBER_OFFSET.)
1178 tsize = count234(ssh->channels);
1182 while (high - low > 1) {
1183 mid = (high + low) / 2;
1184 c = index234(ssh->channels, mid);
1185 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1186 low = mid; /* this one is fine */
1188 high = mid; /* this one is past it */
1191 * Now low points to either -1, or the tree index of the
1192 * largest ID in the initial sequence.
1195 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1196 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1198 return low + 1 + CHANNEL_NUMBER_OFFSET;
1201 static void c_write_stderr(int trusted, const char *buf, int len)
1204 for (i = 0; i < len; i++)
1205 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1206 fputc(buf[i], stderr);
1209 static void c_write(Ssh ssh, const char *buf, int len)
1211 if (flags & FLAG_STDERR)
1212 c_write_stderr(1, buf, len);
1214 from_backend(ssh->frontend, 1, buf, len);
1217 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1219 if (flags & FLAG_STDERR)
1220 c_write_stderr(0, buf, len);
1222 from_backend_untrusted(ssh->frontend, buf, len);
1225 static void c_write_str(Ssh ssh, const char *buf)
1227 c_write(ssh, buf, strlen(buf));
1230 static void ssh_free_packet(struct Packet *pkt)
1235 static struct Packet *ssh_new_packet(void)
1237 struct Packet *pkt = snew(struct Packet);
1239 pkt->body = pkt->data = NULL;
1241 pkt->logmode = PKTLOG_EMIT;
1249 * Collect incoming data in the incoming packet buffer.
1250 * Decipher and verify the packet when it is completely read.
1251 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1252 * Update the *data and *datalen variables.
1253 * Return a Packet structure when a packet is completed.
1255 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1257 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1259 crBegin(ssh->ssh1_rdpkt_crstate);
1261 st->pktin = ssh_new_packet();
1263 st->pktin->type = 0;
1264 st->pktin->length = 0;
1266 for (st->i = st->len = 0; st->i < 4; st->i++) {
1267 while ((*datalen) == 0)
1269 st->len = (st->len << 8) + **data;
1270 (*data)++, (*datalen)--;
1273 st->pad = 8 - (st->len % 8);
1274 st->biglen = st->len + st->pad;
1275 st->pktin->length = st->len - 5;
1277 if (st->biglen < 0) {
1278 bombout(("Extremely large packet length from server suggests"
1279 " data stream corruption"));
1280 ssh_free_packet(st->pktin);
1284 st->pktin->maxlen = st->biglen;
1285 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1287 st->to_read = st->biglen;
1288 st->p = st->pktin->data;
1289 while (st->to_read > 0) {
1290 st->chunk = st->to_read;
1291 while ((*datalen) == 0)
1293 if (st->chunk > (*datalen))
1294 st->chunk = (*datalen);
1295 memcpy(st->p, *data, st->chunk);
1297 *datalen -= st->chunk;
1299 st->to_read -= st->chunk;
1302 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1303 st->biglen, NULL)) {
1304 bombout(("Network attack (CRC compensation) detected!"));
1305 ssh_free_packet(st->pktin);
1310 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1312 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1313 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1314 if (st->gotcrc != st->realcrc) {
1315 bombout(("Incorrect CRC received on packet"));
1316 ssh_free_packet(st->pktin);
1320 st->pktin->body = st->pktin->data + st->pad + 1;
1321 st->pktin->savedpos = 0;
1323 if (ssh->v1_compressing) {
1324 unsigned char *decompblk;
1326 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1327 st->pktin->body - 1, st->pktin->length + 1,
1328 &decompblk, &decomplen)) {
1329 bombout(("Zlib decompression encountered invalid data"));
1330 ssh_free_packet(st->pktin);
1334 if (st->pktin->maxlen < st->pad + decomplen) {
1335 st->pktin->maxlen = st->pad + decomplen;
1336 st->pktin->data = sresize(st->pktin->data,
1337 st->pktin->maxlen + APIEXTRA,
1339 st->pktin->body = st->pktin->data + st->pad + 1;
1342 memcpy(st->pktin->body - 1, decompblk, decomplen);
1344 st->pktin->length = decomplen - 1;
1347 st->pktin->type = st->pktin->body[-1];
1350 * Log incoming packet, possibly omitting sensitive fields.
1354 struct logblank_t blank;
1355 if (ssh->logomitdata) {
1356 int do_blank = FALSE, blank_prefix = 0;
1357 /* "Session data" packets - omit the data field */
1358 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1359 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1360 do_blank = TRUE; blank_prefix = 4;
1361 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1362 do_blank = TRUE; blank_prefix = 8;
1365 blank.offset = blank_prefix;
1366 blank.len = st->pktin->length;
1367 blank.type = PKTLOG_OMIT;
1371 log_packet(ssh->logctx,
1372 PKT_INCOMING, st->pktin->type,
1373 ssh1_pkt_type(st->pktin->type),
1374 st->pktin->body, st->pktin->length,
1375 nblanks, &blank, NULL);
1378 crFinish(st->pktin);
1381 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1383 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1385 crBegin(ssh->ssh2_rdpkt_crstate);
1387 st->pktin = ssh_new_packet();
1389 st->pktin->type = 0;
1390 st->pktin->length = 0;
1392 st->cipherblk = ssh->sccipher->blksize;
1395 if (st->cipherblk < 8)
1397 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1399 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1402 * When dealing with a CBC-mode cipher, we want to avoid the
1403 * possibility of an attacker's tweaking the ciphertext stream
1404 * so as to cause us to feed the same block to the block
1405 * cipher more than once and thus leak information
1406 * (VU#958563). The way we do this is not to take any
1407 * decisions on the basis of anything we've decrypted until
1408 * we've verified it with a MAC. That includes the packet
1409 * length, so we just read data and check the MAC repeatedly,
1410 * and when the MAC passes, see if the length we've got is
1414 /* May as well allocate the whole lot now. */
1415 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1418 /* Read an amount corresponding to the MAC. */
1419 for (st->i = 0; st->i < st->maclen; st->i++) {
1420 while ((*datalen) == 0)
1422 st->pktin->data[st->i] = *(*data)++;
1428 unsigned char seq[4];
1429 ssh->scmac->start(ssh->sc_mac_ctx);
1430 PUT_32BIT(seq, st->incoming_sequence);
1431 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1434 for (;;) { /* Once around this loop per cipher block. */
1435 /* Read another cipher-block's worth, and tack it onto the end. */
1436 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1437 while ((*datalen) == 0)
1439 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1442 /* Decrypt one more block (a little further back in the stream). */
1443 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1444 st->pktin->data + st->packetlen,
1446 /* Feed that block to the MAC. */
1447 ssh->scmac->bytes(ssh->sc_mac_ctx,
1448 st->pktin->data + st->packetlen, st->cipherblk);
1449 st->packetlen += st->cipherblk;
1450 /* See if that gives us a valid packet. */
1451 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1452 st->pktin->data + st->packetlen) &&
1453 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1456 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1457 bombout(("No valid incoming packet found"));
1458 ssh_free_packet(st->pktin);
1462 st->pktin->maxlen = st->packetlen + st->maclen;
1463 st->pktin->data = sresize(st->pktin->data,
1464 st->pktin->maxlen + APIEXTRA,
1467 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1470 * Acquire and decrypt the first block of the packet. This will
1471 * contain the length and padding details.
1473 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1474 while ((*datalen) == 0)
1476 st->pktin->data[st->i] = *(*data)++;
1481 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1482 st->pktin->data, st->cipherblk);
1485 * Now get the length figure.
1487 st->len = toint(GET_32BIT(st->pktin->data));
1490 * _Completely_ silly lengths should be stomped on before they
1491 * do us any more damage.
1493 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1494 (st->len + 4) % st->cipherblk != 0) {
1495 bombout(("Incoming packet was garbled on decryption"));
1496 ssh_free_packet(st->pktin);
1501 * So now we can work out the total packet length.
1503 st->packetlen = st->len + 4;
1506 * Allocate memory for the rest of the packet.
1508 st->pktin->maxlen = st->packetlen + st->maclen;
1509 st->pktin->data = sresize(st->pktin->data,
1510 st->pktin->maxlen + APIEXTRA,
1514 * Read and decrypt the remainder of the packet.
1516 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1518 while ((*datalen) == 0)
1520 st->pktin->data[st->i] = *(*data)++;
1523 /* Decrypt everything _except_ the MAC. */
1525 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1526 st->pktin->data + st->cipherblk,
1527 st->packetlen - st->cipherblk);
1533 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1534 st->len + 4, st->incoming_sequence)) {
1535 bombout(("Incorrect MAC received on packet"));
1536 ssh_free_packet(st->pktin);
1540 /* Get and sanity-check the amount of random padding. */
1541 st->pad = st->pktin->data[4];
1542 if (st->pad < 4 || st->len - st->pad < 1) {
1543 bombout(("Invalid padding length on received packet"));
1544 ssh_free_packet(st->pktin);
1548 * This enables us to deduce the payload length.
1550 st->payload = st->len - st->pad - 1;
1552 st->pktin->length = st->payload + 5;
1553 st->pktin->encrypted_len = st->packetlen;
1555 st->pktin->sequence = st->incoming_sequence++;
1558 * Decompress packet payload.
1561 unsigned char *newpayload;
1564 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1565 st->pktin->data + 5, st->pktin->length - 5,
1566 &newpayload, &newlen)) {
1567 if (st->pktin->maxlen < newlen + 5) {
1568 st->pktin->maxlen = newlen + 5;
1569 st->pktin->data = sresize(st->pktin->data,
1570 st->pktin->maxlen + APIEXTRA,
1573 st->pktin->length = 5 + newlen;
1574 memcpy(st->pktin->data + 5, newpayload, newlen);
1579 st->pktin->savedpos = 6;
1580 st->pktin->body = st->pktin->data;
1581 st->pktin->type = st->pktin->data[5];
1584 * Log incoming packet, possibly omitting sensitive fields.
1588 struct logblank_t blank;
1589 if (ssh->logomitdata) {
1590 int do_blank = FALSE, blank_prefix = 0;
1591 /* "Session data" packets - omit the data field */
1592 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1593 do_blank = TRUE; blank_prefix = 8;
1594 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1595 do_blank = TRUE; blank_prefix = 12;
1598 blank.offset = blank_prefix;
1599 blank.len = (st->pktin->length-6) - blank_prefix;
1600 blank.type = PKTLOG_OMIT;
1604 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1605 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1607 st->pktin->data+6, st->pktin->length-6,
1608 nblanks, &blank, &st->pktin->sequence);
1611 crFinish(st->pktin);
1614 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1616 int pad, biglen, i, pktoffs;
1620 * XXX various versions of SC (including 8.8.4) screw up the
1621 * register allocation in this function and use the same register
1622 * (D6) for len and as a temporary, with predictable results. The
1623 * following sledgehammer prevents this.
1630 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1631 ssh1_pkt_type(pkt->data[12]),
1632 pkt->body, pkt->length - (pkt->body - pkt->data),
1633 pkt->nblanks, pkt->blanks, NULL);
1634 sfree(pkt->blanks); pkt->blanks = NULL;
1637 if (ssh->v1_compressing) {
1638 unsigned char *compblk;
1640 zlib_compress_block(ssh->cs_comp_ctx,
1641 pkt->data + 12, pkt->length - 12,
1642 &compblk, &complen);
1643 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1644 memcpy(pkt->data + 12, compblk, complen);
1646 pkt->length = complen + 12;
1649 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1651 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1652 pad = 8 - (len % 8);
1654 biglen = len + pad; /* len(padding+type+data+CRC) */
1656 for (i = pktoffs; i < 4+8; i++)
1657 pkt->data[i] = random_byte();
1658 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1659 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1660 PUT_32BIT(pkt->data + pktoffs, len);
1663 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1664 pkt->data + pktoffs + 4, biglen);
1666 if (offset_p) *offset_p = pktoffs;
1667 return biglen + 4; /* len(length+padding+type+data+CRC) */
1670 static int s_write(Ssh ssh, void *data, int len)
1673 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1675 return sk_write(ssh->s, (char *)data, len);
1678 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1680 int len, backlog, offset;
1681 len = s_wrpkt_prepare(ssh, pkt, &offset);
1682 backlog = s_write(ssh, pkt->data + offset, len);
1683 if (backlog > SSH_MAX_BACKLOG)
1684 ssh_throttle_all(ssh, 1, backlog);
1685 ssh_free_packet(pkt);
1688 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1691 len = s_wrpkt_prepare(ssh, pkt, &offset);
1692 if (ssh->deferred_len + len > ssh->deferred_size) {
1693 ssh->deferred_size = ssh->deferred_len + len + 128;
1694 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1698 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1699 pkt->data + offset, len);
1700 ssh->deferred_len += len;
1701 ssh_free_packet(pkt);
1705 * Construct a SSH-1 packet with the specified contents.
1706 * (This all-at-once interface used to be the only one, but now SSH-1
1707 * packets can also be constructed incrementally.)
1709 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1715 pkt = ssh1_pkt_init(pkttype);
1717 while ((argtype = va_arg(ap, int)) != PKT_END) {
1718 unsigned char *argp, argchar;
1720 unsigned long argint;
1723 /* Actual fields in the packet */
1725 argint = va_arg(ap, int);
1726 ssh_pkt_adduint32(pkt, argint);
1729 argchar = (unsigned char) va_arg(ap, int);
1730 ssh_pkt_addbyte(pkt, argchar);
1733 argp = va_arg(ap, unsigned char *);
1734 arglen = va_arg(ap, int);
1735 ssh_pkt_adddata(pkt, argp, arglen);
1738 sargp = va_arg(ap, char *);
1739 ssh_pkt_addstring(pkt, sargp);
1742 bn = va_arg(ap, Bignum);
1743 ssh1_pkt_addmp(pkt, bn);
1745 /* Tokens for modifications to packet logging */
1747 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1750 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1753 end_log_omission(ssh, pkt);
1761 static void send_packet(Ssh ssh, int pkttype, ...)
1765 va_start(ap, pkttype);
1766 pkt = construct_packet(ssh, pkttype, ap);
1771 static void defer_packet(Ssh ssh, int pkttype, ...)
1775 va_start(ap, pkttype);
1776 pkt = construct_packet(ssh, pkttype, ap);
1778 s_wrpkt_defer(ssh, pkt);
1781 static int ssh_versioncmp(char *a, char *b)
1784 unsigned long av, bv;
1786 av = strtoul(a, &ae, 10);
1787 bv = strtoul(b, &be, 10);
1789 return (av < bv ? -1 : +1);
1794 av = strtoul(ae, &ae, 10);
1795 bv = strtoul(be, &be, 10);
1797 return (av < bv ? -1 : +1);
1802 * Utility routines for putting an SSH-protocol `string' and
1803 * `uint32' into a hash state.
1805 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1807 unsigned char lenblk[4];
1808 PUT_32BIT(lenblk, len);
1809 h->bytes(s, lenblk, 4);
1810 h->bytes(s, str, len);
1813 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1815 unsigned char intblk[4];
1816 PUT_32BIT(intblk, i);
1817 h->bytes(s, intblk, 4);
1821 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1823 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1825 if (pkt->maxlen < length) {
1826 unsigned char *body = pkt->body;
1827 int offset = body ? body - pkt->data : 0;
1828 pkt->maxlen = length + 256;
1829 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1830 if (body) pkt->body = pkt->data + offset;
1833 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
1835 if (pkt->logmode != PKTLOG_EMIT) {
1837 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1839 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1840 (pkt->body - pkt->data);
1841 pkt->blanks[pkt->nblanks-1].len = len;
1842 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1845 ssh_pkt_ensure(pkt, pkt->length);
1846 memcpy(pkt->data + pkt->length - len, data, len);
1848 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1850 ssh_pkt_adddata(pkt, &byte, 1);
1852 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1854 ssh_pkt_adddata(pkt, &value, 1);
1856 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1859 PUT_32BIT(x, value);
1860 ssh_pkt_adddata(pkt, x, 4);
1862 static void ssh_pkt_addstring_start(struct Packet *pkt)
1864 ssh_pkt_adduint32(pkt, 0);
1865 pkt->savedpos = pkt->length;
1867 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
1869 ssh_pkt_adddata(pkt, data, strlen(data));
1870 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1872 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
1875 ssh_pkt_adddata(pkt, data, len);
1876 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1878 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
1880 ssh_pkt_addstring_start(pkt);
1881 ssh_pkt_addstring_str(pkt, data);
1883 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1885 int len = ssh1_bignum_length(b);
1886 unsigned char *data = snewn(len, unsigned char);
1887 (void) ssh1_write_bignum(data, b);
1888 ssh_pkt_adddata(pkt, data, len);
1891 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1894 int i, n = (bignum_bitcount(b) + 7) / 8;
1895 p = snewn(n + 1, unsigned char);
1897 for (i = 1; i <= n; i++)
1898 p[i] = bignum_byte(b, n - i);
1900 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1902 memmove(p, p + i, n + 1 - i);
1906 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1910 p = ssh2_mpint_fmt(b, &len);
1911 ssh_pkt_addstring_start(pkt);
1912 ssh_pkt_addstring_data(pkt, (char *)p, len);
1916 static struct Packet *ssh1_pkt_init(int pkt_type)
1918 struct Packet *pkt = ssh_new_packet();
1919 pkt->length = 4 + 8; /* space for length + max padding */
1920 ssh_pkt_addbyte(pkt, pkt_type);
1921 pkt->body = pkt->data + pkt->length;
1925 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1926 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1927 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1928 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1929 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1930 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1931 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1932 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1933 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1935 static struct Packet *ssh2_pkt_init(int pkt_type)
1937 struct Packet *pkt = ssh_new_packet();
1938 pkt->length = 5; /* space for packet length + padding length */
1940 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1941 pkt->body = pkt->data + pkt->length; /* after packet type */
1946 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1947 * put the MAC on it. Final packet, ready to be sent, is stored in
1948 * pkt->data. Total length is returned.
1950 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1952 int cipherblk, maclen, padding, i;
1955 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1956 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1957 pkt->body, pkt->length - (pkt->body - pkt->data),
1958 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
1959 sfree(pkt->blanks); pkt->blanks = NULL;
1963 * Compress packet payload.
1966 unsigned char *newpayload;
1969 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1971 &newpayload, &newlen)) {
1973 ssh2_pkt_adddata(pkt, newpayload, newlen);
1979 * Add padding. At least four bytes, and must also bring total
1980 * length (minus MAC) up to a multiple of the block size.
1981 * If pkt->forcepad is set, make sure the packet is at least that size
1984 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1985 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1987 if (pkt->length + padding < pkt->forcepad)
1988 padding = pkt->forcepad - pkt->length;
1990 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1991 assert(padding <= 255);
1992 maclen = ssh->csmac ? ssh->csmac->len : 0;
1993 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1994 pkt->data[4] = padding;
1995 for (i = 0; i < padding; i++)
1996 pkt->data[pkt->length + i] = random_byte();
1997 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1999 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2000 pkt->length + padding,
2001 ssh->v2_outgoing_sequence);
2002 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2005 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2006 pkt->data, pkt->length + padding);
2008 pkt->encrypted_len = pkt->length + padding;
2010 /* Ready-to-send packet starts at pkt->data. We return length. */
2011 return pkt->length + padding + maclen;
2015 * Routines called from the main SSH code to send packets. There
2016 * are quite a few of these, because we have two separate
2017 * mechanisms for delaying the sending of packets:
2019 * - In order to send an IGNORE message and a password message in
2020 * a single fixed-length blob, we require the ability to
2021 * concatenate the encrypted forms of those two packets _into_ a
2022 * single blob and then pass it to our <network.h> transport
2023 * layer in one go. Hence, there's a deferment mechanism which
2024 * works after packet encryption.
2026 * - In order to avoid sending any connection-layer messages
2027 * during repeat key exchange, we have to queue up any such
2028 * outgoing messages _before_ they are encrypted (and in
2029 * particular before they're allocated sequence numbers), and
2030 * then send them once we've finished.
2032 * I call these mechanisms `defer' and `queue' respectively, so as
2033 * to distinguish them reasonably easily.
2035 * The functions send_noqueue() and defer_noqueue() free the packet
2036 * structure they are passed. Every outgoing packet goes through
2037 * precisely one of these functions in its life; packets passed to
2038 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2039 * these or get queued, and then when the queue is later emptied
2040 * the packets are all passed to defer_noqueue().
2042 * When using a CBC-mode cipher, it's necessary to ensure that an
2043 * attacker can't provide data to be encrypted using an IV that they
2044 * know. We ensure this by prefixing each packet that might contain
2045 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2046 * mechanism, so in this case send_noqueue() ends up redirecting to
2047 * defer_noqueue(). If you don't like this inefficiency, don't use
2051 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2052 static void ssh_pkt_defersend(Ssh);
2055 * Send an SSH-2 packet immediately, without queuing or deferring.
2057 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2061 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2062 /* We need to send two packets, so use the deferral mechanism. */
2063 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2064 ssh_pkt_defersend(ssh);
2067 len = ssh2_pkt_construct(ssh, pkt);
2068 backlog = s_write(ssh, pkt->data, len);
2069 if (backlog > SSH_MAX_BACKLOG)
2070 ssh_throttle_all(ssh, 1, backlog);
2072 ssh->outgoing_data_size += pkt->encrypted_len;
2073 if (!ssh->kex_in_progress &&
2074 ssh->max_data_size != 0 &&
2075 ssh->outgoing_data_size > ssh->max_data_size)
2076 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2078 ssh_free_packet(pkt);
2082 * Defer an SSH-2 packet.
2084 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2087 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2088 ssh->deferred_len == 0 && !noignore &&
2089 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2091 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2092 * get encrypted with a known IV.
2094 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2095 ssh2_pkt_addstring_start(ipkt);
2096 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2098 len = ssh2_pkt_construct(ssh, pkt);
2099 if (ssh->deferred_len + len > ssh->deferred_size) {
2100 ssh->deferred_size = ssh->deferred_len + len + 128;
2101 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2105 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
2106 ssh->deferred_len += len;
2107 ssh->deferred_data_size += pkt->encrypted_len;
2108 ssh_free_packet(pkt);
2112 * Queue an SSH-2 packet.
2114 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2116 assert(ssh->queueing);
2118 if (ssh->queuelen >= ssh->queuesize) {
2119 ssh->queuesize = ssh->queuelen + 32;
2120 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2123 ssh->queue[ssh->queuelen++] = pkt;
2127 * Either queue or send a packet, depending on whether queueing is
2130 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2133 ssh2_pkt_queue(ssh, pkt);
2135 ssh2_pkt_send_noqueue(ssh, pkt);
2139 * Either queue or defer a packet, depending on whether queueing is
2142 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2145 ssh2_pkt_queue(ssh, pkt);
2147 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2151 * Send the whole deferred data block constructed by
2152 * ssh2_pkt_defer() or SSH-1's defer_packet().
2154 * The expected use of the defer mechanism is that you call
2155 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2156 * not currently queueing, this simply sets up deferred_send_data
2157 * and then sends it. If we _are_ currently queueing, the calls to
2158 * ssh2_pkt_defer() put the deferred packets on to the queue
2159 * instead, and therefore ssh_pkt_defersend() has no deferred data
2160 * to send. Hence, there's no need to make it conditional on
2163 static void ssh_pkt_defersend(Ssh ssh)
2166 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2167 ssh->deferred_len = ssh->deferred_size = 0;
2168 sfree(ssh->deferred_send_data);
2169 ssh->deferred_send_data = NULL;
2170 if (backlog > SSH_MAX_BACKLOG)
2171 ssh_throttle_all(ssh, 1, backlog);
2173 ssh->outgoing_data_size += ssh->deferred_data_size;
2174 if (!ssh->kex_in_progress &&
2175 ssh->max_data_size != 0 &&
2176 ssh->outgoing_data_size > ssh->max_data_size)
2177 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2178 ssh->deferred_data_size = 0;
2182 * Send a packet whose length needs to be disguised (typically
2183 * passwords or keyboard-interactive responses).
2185 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2191 * The simplest way to do this is to adjust the
2192 * variable-length padding field in the outgoing packet.
2194 * Currently compiled out, because some Cisco SSH servers
2195 * don't like excessively padded packets (bah, why's it
2198 pkt->forcepad = padsize;
2199 ssh2_pkt_send(ssh, pkt);
2204 * If we can't do that, however, an alternative approach is
2205 * to use the pkt_defer mechanism to bundle the packet
2206 * tightly together with an SSH_MSG_IGNORE such that their
2207 * combined length is a constant. So first we construct the
2208 * final form of this packet and defer its sending.
2210 ssh2_pkt_defer(ssh, pkt);
2213 * Now construct an SSH_MSG_IGNORE which includes a string
2214 * that's an exact multiple of the cipher block size. (If
2215 * the cipher is NULL so that the block size is
2216 * unavailable, we don't do this trick at all, because we
2217 * gain nothing by it.)
2219 if (ssh->cscipher &&
2220 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2223 stringlen = (256 - ssh->deferred_len);
2224 stringlen += ssh->cscipher->blksize - 1;
2225 stringlen -= (stringlen % ssh->cscipher->blksize);
2228 * Temporarily disable actual compression, so we
2229 * can guarantee to get this string exactly the
2230 * length we want it. The compression-disabling
2231 * routine should return an integer indicating how
2232 * many bytes we should adjust our string length
2236 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2238 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2239 ssh2_pkt_addstring_start(pkt);
2240 for (i = 0; i < stringlen; i++) {
2241 char c = (char) random_byte();
2242 ssh2_pkt_addstring_data(pkt, &c, 1);
2244 ssh2_pkt_defer(ssh, pkt);
2246 ssh_pkt_defersend(ssh);
2251 * Send all queued SSH-2 packets. We send them by means of
2252 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2253 * packets that needed to be lumped together.
2255 static void ssh2_pkt_queuesend(Ssh ssh)
2259 assert(!ssh->queueing);
2261 for (i = 0; i < ssh->queuelen; i++)
2262 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2265 ssh_pkt_defersend(ssh);
2269 void bndebug(char *string, Bignum b)
2273 p = ssh2_mpint_fmt(b, &len);
2274 debug(("%s", string));
2275 for (i = 0; i < len; i++)
2276 debug((" %02x", p[i]));
2282 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2286 p = ssh2_mpint_fmt(b, &len);
2287 hash_string(h, s, p, len);
2292 * Packet decode functions for both SSH-1 and SSH-2.
2294 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2296 unsigned long value;
2297 if (pkt->length - pkt->savedpos < 4)
2298 return 0; /* arrgh, no way to decline (FIXME?) */
2299 value = GET_32BIT(pkt->body + pkt->savedpos);
2303 static int ssh2_pkt_getbool(struct Packet *pkt)
2305 unsigned long value;
2306 if (pkt->length - pkt->savedpos < 1)
2307 return 0; /* arrgh, no way to decline (FIXME?) */
2308 value = pkt->body[pkt->savedpos] != 0;
2312 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2317 if (pkt->length - pkt->savedpos < 4)
2319 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2324 if (pkt->length - pkt->savedpos < *length)
2326 *p = (char *)(pkt->body + pkt->savedpos);
2327 pkt->savedpos += *length;
2329 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2331 if (pkt->length - pkt->savedpos < length)
2333 pkt->savedpos += length;
2334 return pkt->body + (pkt->savedpos - length);
2336 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2337 unsigned char **keystr)
2341 j = makekey(pkt->body + pkt->savedpos,
2342 pkt->length - pkt->savedpos,
2349 assert(pkt->savedpos < pkt->length);
2353 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2358 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2359 pkt->length - pkt->savedpos, &b);
2367 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2373 ssh_pkt_getstring(pkt, &p, &length);
2378 b = bignum_from_bytes((unsigned char *)p, length);
2383 * Helper function to add an SSH-2 signature blob to a packet.
2384 * Expects to be shown the public key blob as well as the signature
2385 * blob. Normally works just like ssh2_pkt_addstring, but will
2386 * fiddle with the signature packet if necessary for
2387 * BUG_SSH2_RSA_PADDING.
2389 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2390 void *pkblob_v, int pkblob_len,
2391 void *sigblob_v, int sigblob_len)
2393 unsigned char *pkblob = (unsigned char *)pkblob_v;
2394 unsigned char *sigblob = (unsigned char *)sigblob_v;
2396 /* dmemdump(pkblob, pkblob_len); */
2397 /* dmemdump(sigblob, sigblob_len); */
2400 * See if this is in fact an ssh-rsa signature and a buggy
2401 * server; otherwise we can just do this the easy way.
2403 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2404 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2405 int pos, len, siglen;
2408 * Find the byte length of the modulus.
2411 pos = 4+7; /* skip over "ssh-rsa" */
2412 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2413 if (len < 0 || len > pkblob_len - pos - 4)
2415 pos += 4 + len; /* skip over exponent */
2416 if (pkblob_len - pos < 4)
2418 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2419 if (len < 0 || len > pkblob_len - pos - 4)
2421 pos += 4; /* find modulus itself */
2422 while (len > 0 && pkblob[pos] == 0)
2424 /* debug(("modulus length is %d\n", len)); */
2427 * Now find the signature integer.
2429 pos = 4+7; /* skip over "ssh-rsa" */
2430 if (sigblob_len < pos+4)
2432 siglen = toint(GET_32BIT(sigblob+pos));
2433 if (siglen != sigblob_len - pos - 4)
2435 /* debug(("signature length is %d\n", siglen)); */
2437 if (len != siglen) {
2438 unsigned char newlen[4];
2439 ssh2_pkt_addstring_start(pkt);
2440 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2441 /* dmemdump(sigblob, pos); */
2442 pos += 4; /* point to start of actual sig */
2443 PUT_32BIT(newlen, len);
2444 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2445 /* dmemdump(newlen, 4); */
2447 while (len-- > siglen) {
2448 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2449 /* dmemdump(newlen, 1); */
2451 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2452 /* dmemdump(sigblob+pos, siglen); */
2456 /* Otherwise fall through and do it the easy way. We also come
2457 * here as a fallback if we discover above that the key blob
2458 * is misformatted in some way. */
2462 ssh2_pkt_addstring_start(pkt);
2463 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2467 * Examine the remote side's version string and compare it against
2468 * a list of known buggy implementations.
2470 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2472 char *imp; /* pointer to implementation part */
2474 imp += strcspn(imp, "-");
2476 imp += strcspn(imp, "-");
2479 ssh->remote_bugs = 0;
2482 * General notes on server version strings:
2483 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2484 * here -- in particular, we've heard of one that's perfectly happy
2485 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2486 * so we can't distinguish them.
2488 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2489 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2490 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2491 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2492 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2493 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2495 * These versions don't support SSH1_MSG_IGNORE, so we have
2496 * to use a different defence against password length
2499 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2500 logevent("We believe remote version has SSH-1 ignore bug");
2503 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2504 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2505 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2507 * These versions need a plain password sent; they can't
2508 * handle having a null and a random length of data after
2511 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2512 logevent("We believe remote version needs a plain SSH-1 password");
2515 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2516 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2517 (!strcmp(imp, "Cisco-1.25")))) {
2519 * These versions apparently have no clue whatever about
2520 * RSA authentication and will panic and die if they see
2521 * an AUTH_RSA message.
2523 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2524 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2527 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2528 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2529 !wc_match("* VShell", imp) &&
2530 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2531 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2532 wc_match("2.1 *", imp)))) {
2534 * These versions have the HMAC bug.
2536 ssh->remote_bugs |= BUG_SSH2_HMAC;
2537 logevent("We believe remote version has SSH-2 HMAC bug");
2540 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2541 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2542 !wc_match("* VShell", imp) &&
2543 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2545 * These versions have the key-derivation bug (failing to
2546 * include the literal shared secret in the hashes that
2547 * generate the keys).
2549 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2550 logevent("We believe remote version has SSH-2 key-derivation bug");
2553 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2554 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2555 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2556 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2558 * These versions have the SSH-2 RSA padding bug.
2560 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2561 logevent("We believe remote version has SSH-2 RSA padding bug");
2564 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2565 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2566 wc_match("OpenSSH_2.[0-2]*", imp))) {
2568 * These versions have the SSH-2 session-ID bug in
2569 * public-key authentication.
2571 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2572 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2575 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2576 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2577 (wc_match("DigiSSH_2.0", imp) ||
2578 wc_match("OpenSSH_2.[0-4]*", imp) ||
2579 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2580 wc_match("Sun_SSH_1.0", imp) ||
2581 wc_match("Sun_SSH_1.0.1", imp) ||
2582 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2583 wc_match("WeOnlyDo-*", imp)))) {
2585 * These versions have the SSH-2 rekey bug.
2587 ssh->remote_bugs |= BUG_SSH2_REKEY;
2588 logevent("We believe remote version has SSH-2 rekey bug");
2591 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2592 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2593 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2594 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2596 * This version ignores our makpkt and needs to be throttled.
2598 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2599 logevent("We believe remote version ignores SSH-2 maximum packet size");
2602 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2604 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2605 * none detected automatically.
2607 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2608 logevent("We believe remote version has SSH-2 ignore bug");
2611 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2613 * Servers that don't support our winadj request for one
2614 * reason or another. Currently, none detected automatically.
2616 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2617 logevent("We believe remote version has winadj bug");
2622 * The `software version' part of an SSH version string is required
2623 * to contain no spaces or minus signs.
2625 static void ssh_fix_verstring(char *str)
2627 /* Eat "SSH-<protoversion>-". */
2628 assert(*str == 'S'); str++;
2629 assert(*str == 'S'); str++;
2630 assert(*str == 'H'); str++;
2631 assert(*str == '-'); str++;
2632 while (*str && *str != '-') str++;
2633 assert(*str == '-'); str++;
2635 /* Convert minus signs and spaces in the remaining string into
2638 if (*str == '-' || *str == ' ')
2645 * Send an appropriate SSH version string.
2647 static void ssh_send_verstring(Ssh ssh, char *svers)
2651 if (ssh->version == 2) {
2653 * Construct a v2 version string.
2655 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2658 * Construct a v1 version string.
2660 verstring = dupprintf("SSH-%s-%s\012",
2661 (ssh_versioncmp(svers, "1.5") <= 0 ?
2666 ssh_fix_verstring(verstring);
2668 if (ssh->version == 2) {
2671 * Record our version string.
2673 len = strcspn(verstring, "\015\012");
2674 ssh->v_c = snewn(len + 1, char);
2675 memcpy(ssh->v_c, verstring, len);
2679 logeventf(ssh, "We claim version: %.*s",
2680 strcspn(verstring, "\015\012"), verstring);
2681 s_write(ssh, verstring, strlen(verstring));
2685 static int do_ssh_init(Ssh ssh, unsigned char c)
2687 struct do_ssh_init_state {
2696 crState(do_ssh_init_state);
2700 /* Search for a line beginning with the string "SSH-" in the input. */
2702 if (c != 'S') goto no;
2704 if (c != 'S') goto no;
2706 if (c != 'H') goto no;
2708 if (c != '-') goto no;
2717 s->vstring = snewn(s->vstrsize, char);
2718 strcpy(s->vstring, "SSH-");
2722 crReturn(1); /* get another char */
2723 if (s->vslen >= s->vstrsize - 1) {
2725 s->vstring = sresize(s->vstring, s->vstrsize, char);
2727 s->vstring[s->vslen++] = c;
2730 s->version[s->i] = '\0';
2732 } else if (s->i < sizeof(s->version) - 1)
2733 s->version[s->i++] = c;
2734 } else if (c == '\012')
2738 ssh->agentfwd_enabled = FALSE;
2739 ssh->rdpkt2_state.incoming_sequence = 0;
2741 s->vstring[s->vslen] = 0;
2742 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2743 logeventf(ssh, "Server version: %s", s->vstring);
2744 ssh_detect_bugs(ssh, s->vstring);
2747 * Decide which SSH protocol version to support.
2750 /* Anything strictly below "2.0" means protocol 1 is supported. */
2751 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2752 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2753 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2755 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2756 bombout(("SSH protocol version 1 required by user but not provided by server"));
2759 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2760 bombout(("SSH protocol version 2 required by user but not provided by server"));
2764 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2769 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2771 /* Send the version string, if we haven't already */
2772 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2773 ssh_send_verstring(ssh, s->version);
2775 if (ssh->version == 2) {
2778 * Record their version string.
2780 len = strcspn(s->vstring, "\015\012");
2781 ssh->v_s = snewn(len + 1, char);
2782 memcpy(ssh->v_s, s->vstring, len);
2786 * Initialise SSH-2 protocol.
2788 ssh->protocol = ssh2_protocol;
2789 ssh2_protocol_setup(ssh);
2790 ssh->s_rdpkt = ssh2_rdpkt;
2793 * Initialise SSH-1 protocol.
2795 ssh->protocol = ssh1_protocol;
2796 ssh1_protocol_setup(ssh);
2797 ssh->s_rdpkt = ssh1_rdpkt;
2799 if (ssh->version == 2)
2800 do_ssh2_transport(ssh, NULL, -1, NULL);
2802 update_specials_menu(ssh->frontend);
2803 ssh->state = SSH_STATE_BEFORE_SIZE;
2804 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
2811 static void ssh_process_incoming_data(Ssh ssh,
2812 unsigned char **data, int *datalen)
2814 struct Packet *pktin;
2816 pktin = ssh->s_rdpkt(ssh, data, datalen);
2818 ssh->protocol(ssh, NULL, 0, pktin);
2819 ssh_free_packet(pktin);
2823 static void ssh_queue_incoming_data(Ssh ssh,
2824 unsigned char **data, int *datalen)
2826 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2831 static void ssh_process_queued_incoming_data(Ssh ssh)
2834 unsigned char *data;
2837 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2838 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2842 while (!ssh->frozen && len > 0)
2843 ssh_process_incoming_data(ssh, &data, &len);
2846 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2850 static void ssh_set_frozen(Ssh ssh, int frozen)
2853 sk_set_frozen(ssh->s, frozen);
2854 ssh->frozen = frozen;
2857 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2859 /* Log raw data, if we're in that mode. */
2861 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2864 crBegin(ssh->ssh_gotdata_crstate);
2867 * To begin with, feed the characters one by one to the
2868 * protocol initialisation / selection function do_ssh_init().
2869 * When that returns 0, we're done with the initial greeting
2870 * exchange and can move on to packet discipline.
2873 int ret; /* need not be kept across crReturn */
2875 crReturnV; /* more data please */
2876 ret = do_ssh_init(ssh, *data);
2884 * We emerge from that loop when the initial negotiation is
2885 * over and we have selected an s_rdpkt function. Now pass
2886 * everything to s_rdpkt, and then pass the resulting packets
2887 * to the proper protocol handler.
2891 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2893 ssh_queue_incoming_data(ssh, &data, &datalen);
2894 /* This uses up all data and cannot cause anything interesting
2895 * to happen; indeed, for anything to happen at all, we must
2896 * return, so break out. */
2898 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2899 /* This uses up some or all data, and may freeze the
2901 ssh_process_queued_incoming_data(ssh);
2903 /* This uses up some or all data, and may freeze the
2905 ssh_process_incoming_data(ssh, &data, &datalen);
2907 /* FIXME this is probably EBW. */
2908 if (ssh->state == SSH_STATE_CLOSED)
2911 /* We're out of data. Go and get some more. */
2917 static int ssh_do_close(Ssh ssh, int notify_exit)
2920 struct ssh_channel *c;
2922 ssh->state = SSH_STATE_CLOSED;
2923 expire_timer_context(ssh);
2928 notify_remote_exit(ssh->frontend);
2933 * Now we must shut down any port- and X-forwarded channels going
2934 * through this connection.
2936 if (ssh->channels) {
2937 while (NULL != (c = index234(ssh->channels, 0))) {
2940 x11_close(c->u.x11.s);
2943 case CHAN_SOCKDATA_DORMANT:
2944 pfd_close(c->u.pfd.s);
2947 del234(ssh->channels, c); /* moving next one to index 0 */
2948 if (ssh->version == 2)
2949 bufchain_clear(&c->v.v2.outbuffer);
2954 * Go through port-forwardings, and close any associated
2955 * listening sockets.
2957 if (ssh->portfwds) {
2958 struct ssh_portfwd *pf;
2959 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2960 /* Dispose of any listening socket. */
2962 pfd_terminate(pf->local);
2963 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2966 freetree234(ssh->portfwds);
2967 ssh->portfwds = NULL;
2973 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2974 const char *error_msg, int error_code)
2976 Ssh ssh = (Ssh) plug;
2977 char addrbuf[256], *msg;
2979 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2982 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2984 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2990 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2993 Ssh ssh = (Ssh) plug;
2994 int need_notify = ssh_do_close(ssh, FALSE);
2997 if (!ssh->close_expected)
2998 error_msg = "Server unexpectedly closed network connection";
3000 error_msg = "Server closed network connection";
3003 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3007 notify_remote_exit(ssh->frontend);
3010 logevent(error_msg);
3011 if (!ssh->close_expected || !ssh->clean_exit)
3012 connection_fatal(ssh->frontend, "%s", error_msg);
3016 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3018 Ssh ssh = (Ssh) plug;
3019 ssh_gotdata(ssh, (unsigned char *)data, len);
3020 if (ssh->state == SSH_STATE_CLOSED) {
3021 ssh_do_close(ssh, TRUE);
3027 static void ssh_sent(Plug plug, int bufsize)
3029 Ssh ssh = (Ssh) plug;
3031 * If the send backlog on the SSH socket itself clears, we
3032 * should unthrottle the whole world if it was throttled.
3034 if (bufsize < SSH_MAX_BACKLOG)
3035 ssh_throttle_all(ssh, 0, bufsize);
3039 * Connect to specified host and port.
3040 * Returns an error message, or NULL on success.
3041 * Also places the canonical host name into `realhost'. It must be
3042 * freed by the caller.
3044 static const char *connect_to_host(Ssh ssh, char *host, int port,
3045 char **realhost, int nodelay, int keepalive)
3047 static const struct plug_function_table fn_table = {
3058 int addressfamily, sshprot;
3060 loghost = conf_get_str(ssh->conf, CONF_loghost);
3064 ssh->savedhost = dupstr(loghost);
3065 ssh->savedport = 22; /* default ssh port */
3068 * A colon suffix on savedhost also lets us affect
3071 * (FIXME: do something about IPv6 address literals here.)
3073 colon = strrchr(ssh->savedhost, ':');
3077 ssh->savedport = atoi(colon);
3080 ssh->savedhost = dupstr(host);
3082 port = 22; /* default ssh port */
3083 ssh->savedport = port;
3089 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3090 logeventf(ssh, "Looking up host \"%s\"%s", host,
3091 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3092 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3093 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3094 if ((err = sk_addr_error(addr)) != NULL) {
3098 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3103 ssh->fn = &fn_table;
3104 ssh->s = new_connection(addr, *realhost, port,
3105 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
3106 if ((err = sk_socket_error(ssh->s)) != NULL) {
3108 notify_remote_exit(ssh->frontend);
3113 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3114 * send the version string too.
3116 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3121 ssh_send_verstring(ssh, NULL);
3125 * loghost, if configured, overrides realhost.
3129 *realhost = dupstr(loghost);
3136 * Throttle or unthrottle the SSH connection.
3138 static void ssh_throttle_conn(Ssh ssh, int adjust)
3140 int old_count = ssh->conn_throttle_count;
3141 ssh->conn_throttle_count += adjust;
3142 assert(ssh->conn_throttle_count >= 0);
3143 if (ssh->conn_throttle_count && !old_count) {
3144 ssh_set_frozen(ssh, 1);
3145 } else if (!ssh->conn_throttle_count && old_count) {
3146 ssh_set_frozen(ssh, 0);
3151 * Throttle or unthrottle _all_ local data streams (for when sends
3152 * on the SSH connection itself back up).
3154 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3157 struct ssh_channel *c;
3159 if (enable == ssh->throttled_all)
3161 ssh->throttled_all = enable;
3162 ssh->overall_bufsize = bufsize;
3165 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3167 case CHAN_MAINSESSION:
3169 * This is treated separately, outside the switch.
3173 x11_override_throttle(c->u.x11.s, enable);
3176 /* Agent channels require no buffer management. */
3179 pfd_override_throttle(c->u.pfd.s, enable);
3185 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3187 Ssh ssh = (Ssh) sshv;
3189 ssh->agent_response = reply;
3190 ssh->agent_response_len = replylen;
3192 if (ssh->version == 1)
3193 do_ssh1_login(ssh, NULL, -1, NULL);
3195 do_ssh2_authconn(ssh, NULL, -1, NULL);
3198 static void ssh_dialog_callback(void *sshv, int ret)
3200 Ssh ssh = (Ssh) sshv;
3202 ssh->user_response = ret;
3204 if (ssh->version == 1)
3205 do_ssh1_login(ssh, NULL, -1, NULL);
3207 do_ssh2_transport(ssh, NULL, -1, NULL);
3210 * This may have unfrozen the SSH connection, so do a
3213 ssh_process_queued_incoming_data(ssh);
3216 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3218 struct ssh_channel *c = (struct ssh_channel *)cv;
3220 void *sentreply = reply;
3222 c->u.a.outstanding_requests--;
3224 /* Fake SSH_AGENT_FAILURE. */
3225 sentreply = "\0\0\0\1\5";
3228 if (ssh->version == 2) {
3229 ssh2_add_channel_data(c, sentreply, replylen);
3232 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3233 PKT_INT, c->remoteid,
3236 PKT_DATA, sentreply, replylen,
3243 * If we've already seen an incoming EOF but haven't sent an
3244 * outgoing one, this may be the moment to send it.
3246 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3247 sshfwd_write_eof(c);
3251 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3252 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3253 * => log `wire_reason'.
3255 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3256 int code, int clean_exit)
3260 client_reason = wire_reason;
3262 error = dupprintf("Disconnected: %s", client_reason);
3264 error = dupstr("Disconnected");
3266 if (ssh->version == 1) {
3267 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3269 } else if (ssh->version == 2) {
3270 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3271 ssh2_pkt_adduint32(pktout, code);
3272 ssh2_pkt_addstring(pktout, wire_reason);
3273 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3274 ssh2_pkt_send_noqueue(ssh, pktout);
3277 ssh->close_expected = TRUE;
3278 ssh->clean_exit = clean_exit;
3279 ssh_closing((Plug)ssh, error, 0, 0);
3284 * Handle the key exchange and user authentication phases.
3286 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3287 struct Packet *pktin)
3290 unsigned char cookie[8], *ptr;
3291 struct MD5Context md5c;
3292 struct do_ssh1_login_state {
3295 unsigned char *rsabuf, *keystr1, *keystr2;
3296 unsigned long supported_ciphers_mask, supported_auths_mask;
3297 int tried_publickey, tried_agent;
3298 int tis_auth_refused, ccard_auth_refused;
3299 unsigned char session_id[16];
3301 void *publickey_blob;
3302 int publickey_bloblen;
3303 char *publickey_comment;
3304 int publickey_encrypted;
3305 prompts_t *cur_prompt;
3308 unsigned char request[5], *response, *p;
3318 struct RSAKey servkey, hostkey;
3320 crState(do_ssh1_login_state);
3327 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3328 bombout(("Public key packet not received"));
3332 logevent("Received public keys");
3334 ptr = ssh_pkt_getdata(pktin, 8);
3336 bombout(("SSH-1 public key packet stopped before random cookie"));
3339 memcpy(cookie, ptr, 8);
3341 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3342 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3343 bombout(("Failed to read SSH-1 public keys from public key packet"));
3348 * Log the host key fingerprint.
3352 logevent("Host key fingerprint is:");
3353 strcpy(logmsg, " ");
3354 s->hostkey.comment = NULL;
3355 rsa_fingerprint(logmsg + strlen(logmsg),
3356 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3360 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3361 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3362 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3363 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3364 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3366 ssh->v1_local_protoflags =
3367 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3368 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3371 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3372 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3373 MD5Update(&md5c, cookie, 8);
3374 MD5Final(s->session_id, &md5c);
3376 for (i = 0; i < 32; i++)
3377 ssh->session_key[i] = random_byte();
3380 * Verify that the `bits' and `bytes' parameters match.
3382 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3383 s->servkey.bits > s->servkey.bytes * 8) {
3384 bombout(("SSH-1 public keys were badly formatted"));
3388 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3389 s->hostkey.bytes : s->servkey.bytes);
3391 s->rsabuf = snewn(s->len, unsigned char);
3394 * Verify the host key.
3398 * First format the key into a string.
3400 int len = rsastr_len(&s->hostkey);
3401 char fingerprint[100];
3402 char *keystr = snewn(len, char);
3403 rsastr_fmt(keystr, &s->hostkey);
3404 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3406 ssh_set_frozen(ssh, 1);
3407 s->dlgret = verify_ssh_host_key(ssh->frontend,
3408 ssh->savedhost, ssh->savedport,
3409 "rsa", keystr, fingerprint,
3410 ssh_dialog_callback, ssh);
3412 if (s->dlgret < 0) {
3416 bombout(("Unexpected data from server while waiting"
3417 " for user host key response"));
3420 } while (pktin || inlen > 0);
3421 s->dlgret = ssh->user_response;
3423 ssh_set_frozen(ssh, 0);
3425 if (s->dlgret == 0) {
3426 ssh_disconnect(ssh, "User aborted at host key verification",
3432 for (i = 0; i < 32; i++) {
3433 s->rsabuf[i] = ssh->session_key[i];
3435 s->rsabuf[i] ^= s->session_id[i];
3438 if (s->hostkey.bytes > s->servkey.bytes) {
3439 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3441 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3443 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3445 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3448 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3452 logevent("Encrypted session key");
3455 int cipher_chosen = 0, warn = 0;
3456 char *cipher_string = NULL;
3458 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3459 int next_cipher = conf_get_int_int(ssh->conf,
3460 CONF_ssh_cipherlist, i);
3461 if (next_cipher == CIPHER_WARN) {
3462 /* If/when we choose a cipher, warn about it */
3464 } else if (next_cipher == CIPHER_AES) {
3465 /* XXX Probably don't need to mention this. */
3466 logevent("AES not supported in SSH-1, skipping");
3468 switch (next_cipher) {
3469 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3470 cipher_string = "3DES"; break;
3471 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3472 cipher_string = "Blowfish"; break;
3473 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3474 cipher_string = "single-DES"; break;
3476 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3480 if (!cipher_chosen) {
3481 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3482 bombout(("Server violates SSH-1 protocol by not "
3483 "supporting 3DES encryption"));
3485 /* shouldn't happen */
3486 bombout(("No supported ciphers found"));
3490 /* Warn about chosen cipher if necessary. */
3492 ssh_set_frozen(ssh, 1);
3493 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3494 ssh_dialog_callback, ssh);
3495 if (s->dlgret < 0) {
3499 bombout(("Unexpected data from server while waiting"
3500 " for user response"));
3503 } while (pktin || inlen > 0);
3504 s->dlgret = ssh->user_response;
3506 ssh_set_frozen(ssh, 0);
3507 if (s->dlgret == 0) {
3508 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3515 switch (s->cipher_type) {
3516 case SSH_CIPHER_3DES:
3517 logevent("Using 3DES encryption");
3519 case SSH_CIPHER_DES:
3520 logevent("Using single-DES encryption");
3522 case SSH_CIPHER_BLOWFISH:
3523 logevent("Using Blowfish encryption");
3527 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3528 PKT_CHAR, s->cipher_type,
3529 PKT_DATA, cookie, 8,
3530 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3531 PKT_DATA, s->rsabuf, s->len,
3532 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3534 logevent("Trying to enable encryption...");
3538 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3539 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3541 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3542 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3543 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3545 ssh->crcda_ctx = crcda_make_context();
3546 logevent("Installing CRC compensation attack detector");
3548 if (s->servkey.modulus) {
3549 sfree(s->servkey.modulus);
3550 s->servkey.modulus = NULL;
3552 if (s->servkey.exponent) {
3553 sfree(s->servkey.exponent);
3554 s->servkey.exponent = NULL;
3556 if (s->hostkey.modulus) {
3557 sfree(s->hostkey.modulus);
3558 s->hostkey.modulus = NULL;
3560 if (s->hostkey.exponent) {
3561 sfree(s->hostkey.exponent);
3562 s->hostkey.exponent = NULL;
3566 if (pktin->type != SSH1_SMSG_SUCCESS) {
3567 bombout(("Encryption not successfully enabled"));
3571 logevent("Successfully started encryption");
3573 fflush(stdout); /* FIXME eh? */
3575 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3576 int ret; /* need not be kept over crReturn */
3577 s->cur_prompt = new_prompts(ssh->frontend);
3578 s->cur_prompt->to_server = TRUE;
3579 s->cur_prompt->name = dupstr("SSH login name");
3580 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3581 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3584 crWaitUntil(!pktin);
3585 ret = get_userpass_input(s->cur_prompt, in, inlen);
3590 * Failed to get a username. Terminate.
3592 free_prompts(s->cur_prompt);
3593 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3596 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3597 free_prompts(s->cur_prompt);
3600 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3602 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
3604 if (flags & FLAG_INTERACTIVE &&
3605 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3606 c_write_str(ssh, userlog);
3607 c_write_str(ssh, "\r\n");
3615 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3616 /* We must not attempt PK auth. Pretend we've already tried it. */
3617 s->tried_publickey = s->tried_agent = 1;
3619 s->tried_publickey = s->tried_agent = 0;
3621 s->tis_auth_refused = s->ccard_auth_refused = 0;
3623 * Load the public half of any configured keyfile for later use.
3625 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3626 if (!filename_is_null(s->keyfile)) {
3628 logeventf(ssh, "Reading private key file \"%.150s\"",
3629 filename_to_str(s->keyfile));
3630 keytype = key_type(s->keyfile);
3631 if (keytype == SSH_KEYTYPE_SSH1) {
3633 if (rsakey_pubblob(s->keyfile,
3634 &s->publickey_blob, &s->publickey_bloblen,
3635 &s->publickey_comment, &error)) {
3636 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
3640 logeventf(ssh, "Unable to load private key (%s)", error);
3641 msgbuf = dupprintf("Unable to load private key file "
3642 "\"%.150s\" (%s)\r\n",
3643 filename_to_str(s->keyfile),
3645 c_write_str(ssh, msgbuf);
3647 s->publickey_blob = NULL;
3651 logeventf(ssh, "Unable to use this key file (%s)",
3652 key_type_to_str(keytype));
3653 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3655 filename_to_str(s->keyfile),
3656 key_type_to_str(keytype));
3657 c_write_str(ssh, msgbuf);
3659 s->publickey_blob = NULL;
3662 s->publickey_blob = NULL;
3664 while (pktin->type == SSH1_SMSG_FAILURE) {
3665 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3667 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
3669 * Attempt RSA authentication using Pageant.
3675 logevent("Pageant is running. Requesting keys.");
3677 /* Request the keys held by the agent. */
3678 PUT_32BIT(s->request, 1);
3679 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3680 if (!agent_query(s->request, 5, &r, &s->responselen,
3681 ssh_agent_callback, ssh)) {
3685 bombout(("Unexpected data from server while waiting"
3686 " for agent response"));
3689 } while (pktin || inlen > 0);
3690 r = ssh->agent_response;
3691 s->responselen = ssh->agent_response_len;
3693 s->response = (unsigned char *) r;
3694 if (s->response && s->responselen >= 5 &&
3695 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3696 s->p = s->response + 5;
3697 s->nkeys = toint(GET_32BIT(s->p));
3699 logeventf(ssh, "Pageant reported negative key count %d",
3704 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3705 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3706 unsigned char *pkblob = s->p;
3710 do { /* do while (0) to make breaking easy */
3711 n = ssh1_read_bignum
3712 (s->p, toint(s->responselen-(s->p-s->response)),
3717 n = ssh1_read_bignum
3718 (s->p, toint(s->responselen-(s->p-s->response)),
3723 if (s->responselen - (s->p-s->response) < 4)
3725 s->commentlen = toint(GET_32BIT(s->p));
3727 if (s->commentlen < 0 ||
3728 toint(s->responselen - (s->p-s->response)) <
3731 s->commentp = (char *)s->p;
3732 s->p += s->commentlen;
3736 logevent("Pageant key list packet was truncated");
3740 if (s->publickey_blob) {
3741 if (!memcmp(pkblob, s->publickey_blob,
3742 s->publickey_bloblen)) {
3743 logeventf(ssh, "Pageant key #%d matches "
3744 "configured key file", s->keyi);
3745 s->tried_publickey = 1;
3747 /* Skip non-configured key */
3750 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3751 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3752 PKT_BIGNUM, s->key.modulus, PKT_END);
3754 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3755 logevent("Key refused");
3758 logevent("Received RSA challenge");
3759 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3760 bombout(("Server's RSA challenge was badly formatted"));
3765 char *agentreq, *q, *ret;
3768 len = 1 + 4; /* message type, bit count */
3769 len += ssh1_bignum_length(s->key.exponent);
3770 len += ssh1_bignum_length(s->key.modulus);
3771 len += ssh1_bignum_length(s->challenge);
3772 len += 16; /* session id */
3773 len += 4; /* response format */
3774 agentreq = snewn(4 + len, char);
3775 PUT_32BIT(agentreq, len);
3777 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3778 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3780 q += ssh1_write_bignum(q, s->key.exponent);
3781 q += ssh1_write_bignum(q, s->key.modulus);
3782 q += ssh1_write_bignum(q, s->challenge);
3783 memcpy(q, s->session_id, 16);
3785 PUT_32BIT(q, 1); /* response format */
3786 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3787 ssh_agent_callback, ssh)) {
3792 bombout(("Unexpected data from server"
3793 " while waiting for agent"
3797 } while (pktin || inlen > 0);
3798 vret = ssh->agent_response;
3799 retlen = ssh->agent_response_len;
3804 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3805 logevent("Sending Pageant's response");
3806 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3807 PKT_DATA, ret + 5, 16,
3811 if (pktin->type == SSH1_SMSG_SUCCESS) {
3813 ("Pageant's response accepted");
3814 if (flags & FLAG_VERBOSE) {
3815 c_write_str(ssh, "Authenticated using"
3817 c_write(ssh, s->commentp,
3819 c_write_str(ssh, "\" from agent\r\n");
3824 ("Pageant's response not accepted");
3827 ("Pageant failed to answer challenge");
3831 logevent("No reply received from Pageant");
3834 freebn(s->key.exponent);
3835 freebn(s->key.modulus);
3836 freebn(s->challenge);
3841 if (s->publickey_blob && !s->tried_publickey)
3842 logevent("Configured key file not in Pageant");
3844 logevent("Failed to get reply from Pageant");
3849 if (s->publickey_blob && !s->tried_publickey) {
3851 * Try public key authentication with the specified
3854 int got_passphrase; /* need not be kept over crReturn */
3855 if (flags & FLAG_VERBOSE)
3856 c_write_str(ssh, "Trying public key authentication.\r\n");
3857 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3858 logeventf(ssh, "Trying public key \"%s\"",
3859 filename_to_str(s->keyfile));
3860 s->tried_publickey = 1;
3861 got_passphrase = FALSE;
3862 while (!got_passphrase) {
3864 * Get a passphrase, if necessary.
3866 char *passphrase = NULL; /* only written after crReturn */
3868 if (!s->publickey_encrypted) {
3869 if (flags & FLAG_VERBOSE)
3870 c_write_str(ssh, "No passphrase required.\r\n");
3873 int ret; /* need not be kept over crReturn */
3874 s->cur_prompt = new_prompts(ssh->frontend);
3875 s->cur_prompt->to_server = FALSE;
3876 s->cur_prompt->name = dupstr("SSH key passphrase");
3877 add_prompt(s->cur_prompt,
3878 dupprintf("Passphrase for key \"%.100s\": ",
3879 s->publickey_comment), FALSE);
3880 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3883 crWaitUntil(!pktin);
3884 ret = get_userpass_input(s->cur_prompt, in, inlen);
3888 /* Failed to get a passphrase. Terminate. */
3889 free_prompts(s->cur_prompt);
3890 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3894 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3895 free_prompts(s->cur_prompt);
3898 * Try decrypting key with passphrase.
3900 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3901 ret = loadrsakey(s->keyfile, &s->key, passphrase,
3904 smemclr(passphrase, strlen(passphrase));
3908 /* Correct passphrase. */
3909 got_passphrase = TRUE;
3910 } else if (ret == 0) {
3911 c_write_str(ssh, "Couldn't load private key from ");
3912 c_write_str(ssh, filename_to_str(s->keyfile));
3913 c_write_str(ssh, " (");
3914 c_write_str(ssh, error);
3915 c_write_str(ssh, ").\r\n");
3916 got_passphrase = FALSE;
3917 break; /* go and try something else */
3918 } else if (ret == -1) {
3919 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3920 got_passphrase = FALSE;
3923 assert(0 && "unexpected return from loadrsakey()");
3924 got_passphrase = FALSE; /* placate optimisers */
3928 if (got_passphrase) {
3931 * Send a public key attempt.
3933 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3934 PKT_BIGNUM, s->key.modulus, PKT_END);
3937 if (pktin->type == SSH1_SMSG_FAILURE) {
3938 c_write_str(ssh, "Server refused our public key.\r\n");
3939 continue; /* go and try something else */
3941 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3942 bombout(("Bizarre response to offer of public key"));
3948 unsigned char buffer[32];
3949 Bignum challenge, response;
3951 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3952 bombout(("Server's RSA challenge was badly formatted"));
3955 response = rsadecrypt(challenge, &s->key);
3956 freebn(s->key.private_exponent);/* burn the evidence */
3958 for (i = 0; i < 32; i++) {
3959 buffer[i] = bignum_byte(response, 31 - i);
3963 MD5Update(&md5c, buffer, 32);
3964 MD5Update(&md5c, s->session_id, 16);
3965 MD5Final(buffer, &md5c);
3967 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3968 PKT_DATA, buffer, 16, PKT_END);
3975 if (pktin->type == SSH1_SMSG_FAILURE) {
3976 if (flags & FLAG_VERBOSE)
3977 c_write_str(ssh, "Failed to authenticate with"
3978 " our public key.\r\n");
3979 continue; /* go and try something else */
3980 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3981 bombout(("Bizarre response to RSA authentication response"));
3985 break; /* we're through! */
3991 * Otherwise, try various forms of password-like authentication.
3993 s->cur_prompt = new_prompts(ssh->frontend);
3995 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
3996 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3997 !s->tis_auth_refused) {
3998 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3999 logevent("Requested TIS authentication");
4000 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4002 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4003 logevent("TIS authentication declined");
4004 if (flags & FLAG_INTERACTIVE)
4005 c_write_str(ssh, "TIS authentication refused.\r\n");
4006 s->tis_auth_refused = 1;
4011 char *instr_suf, *prompt;
4013 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4015 bombout(("TIS challenge packet was badly formed"));
4018 logevent("Received TIS challenge");
4019 s->cur_prompt->to_server = TRUE;
4020 s->cur_prompt->name = dupstr("SSH TIS authentication");
4021 /* Prompt heuristic comes from OpenSSH */
4022 if (memchr(challenge, '\n', challengelen)) {
4023 instr_suf = dupstr("");
4024 prompt = dupprintf("%.*s", challengelen, challenge);
4026 instr_suf = dupprintf("%.*s", challengelen, challenge);
4027 prompt = dupstr("Response: ");
4029 s->cur_prompt->instruction =
4030 dupprintf("Using TIS authentication.%s%s",
4031 (*instr_suf) ? "\n" : "",
4033 s->cur_prompt->instr_reqd = TRUE;
4034 add_prompt(s->cur_prompt, prompt, FALSE);
4038 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4039 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4040 !s->ccard_auth_refused) {
4041 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4042 logevent("Requested CryptoCard authentication");
4043 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4045 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4046 logevent("CryptoCard authentication declined");
4047 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4048 s->ccard_auth_refused = 1;
4053 char *instr_suf, *prompt;
4055 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4057 bombout(("CryptoCard challenge packet was badly formed"));
4060 logevent("Received CryptoCard challenge");
4061 s->cur_prompt->to_server = TRUE;
4062 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4063 s->cur_prompt->name_reqd = FALSE;
4064 /* Prompt heuristic comes from OpenSSH */
4065 if (memchr(challenge, '\n', challengelen)) {
4066 instr_suf = dupstr("");
4067 prompt = dupprintf("%.*s", challengelen, challenge);
4069 instr_suf = dupprintf("%.*s", challengelen, challenge);
4070 prompt = dupstr("Response: ");
4072 s->cur_prompt->instruction =
4073 dupprintf("Using CryptoCard authentication.%s%s",
4074 (*instr_suf) ? "\n" : "",
4076 s->cur_prompt->instr_reqd = TRUE;
4077 add_prompt(s->cur_prompt, prompt, FALSE);
4081 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4082 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4083 bombout(("No supported authentication methods available"));
4086 s->cur_prompt->to_server = TRUE;
4087 s->cur_prompt->name = dupstr("SSH password");
4088 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4089 ssh->username, ssh->savedhost),
4094 * Show password prompt, having first obtained it via a TIS
4095 * or CryptoCard exchange if we're doing TIS or CryptoCard
4099 int ret; /* need not be kept over crReturn */
4100 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4103 crWaitUntil(!pktin);
4104 ret = get_userpass_input(s->cur_prompt, in, inlen);
4109 * Failed to get a password (for example
4110 * because one was supplied on the command line
4111 * which has already failed to work). Terminate.
4113 free_prompts(s->cur_prompt);
4114 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4119 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4121 * Defence against traffic analysis: we send a
4122 * whole bunch of packets containing strings of
4123 * different lengths. One of these strings is the
4124 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4125 * The others are all random data in
4126 * SSH1_MSG_IGNORE packets. This way a passive
4127 * listener can't tell which is the password, and
4128 * hence can't deduce the password length.
4130 * Anybody with a password length greater than 16
4131 * bytes is going to have enough entropy in their
4132 * password that a listener won't find it _that_
4133 * much help to know how long it is. So what we'll
4136 * - if password length < 16, we send 15 packets
4137 * containing string lengths 1 through 15
4139 * - otherwise, we let N be the nearest multiple
4140 * of 8 below the password length, and send 8
4141 * packets containing string lengths N through
4142 * N+7. This won't obscure the order of
4143 * magnitude of the password length, but it will
4144 * introduce a bit of extra uncertainty.
4146 * A few servers can't deal with SSH1_MSG_IGNORE, at
4147 * least in this context. For these servers, we need
4148 * an alternative defence. We make use of the fact
4149 * that the password is interpreted as a C string:
4150 * so we can append a NUL, then some random data.
4152 * A few servers can deal with neither SSH1_MSG_IGNORE
4153 * here _nor_ a padded password string.
4154 * For these servers we are left with no defences
4155 * against password length sniffing.
4157 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4158 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4160 * The server can deal with SSH1_MSG_IGNORE, so
4161 * we can use the primary defence.
4163 int bottom, top, pwlen, i;
4166 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4168 bottom = 0; /* zero length passwords are OK! :-) */
4171 bottom = pwlen & ~7;
4175 assert(pwlen >= bottom && pwlen <= top);
4177 randomstr = snewn(top + 1, char);
4179 for (i = bottom; i <= top; i++) {
4181 defer_packet(ssh, s->pwpkt_type,
4182 PKTT_PASSWORD, PKT_STR,
4183 s->cur_prompt->prompts[0]->result,
4184 PKTT_OTHER, PKT_END);
4186 for (j = 0; j < i; j++) {
4188 randomstr[j] = random_byte();
4189 } while (randomstr[j] == '\0');
4191 randomstr[i] = '\0';
4192 defer_packet(ssh, SSH1_MSG_IGNORE,
4193 PKT_STR, randomstr, PKT_END);
4196 logevent("Sending password with camouflage packets");
4197 ssh_pkt_defersend(ssh);
4200 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4202 * The server can't deal with SSH1_MSG_IGNORE
4203 * but can deal with padded passwords, so we
4204 * can use the secondary defence.
4210 len = strlen(s->cur_prompt->prompts[0]->result);
4211 if (len < sizeof(string)) {
4213 strcpy(string, s->cur_prompt->prompts[0]->result);
4214 len++; /* cover the zero byte */
4215 while (len < sizeof(string)) {
4216 string[len++] = (char) random_byte();
4219 ss = s->cur_prompt->prompts[0]->result;
4221 logevent("Sending length-padded password");
4222 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4223 PKT_INT, len, PKT_DATA, ss, len,
4224 PKTT_OTHER, PKT_END);
4227 * The server is believed unable to cope with
4228 * any of our password camouflage methods.
4231 len = strlen(s->cur_prompt->prompts[0]->result);
4232 logevent("Sending unpadded password");
4233 send_packet(ssh, s->pwpkt_type,
4234 PKTT_PASSWORD, PKT_INT, len,
4235 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4236 PKTT_OTHER, PKT_END);
4239 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4240 PKT_STR, s->cur_prompt->prompts[0]->result,
4241 PKTT_OTHER, PKT_END);
4243 logevent("Sent password");
4244 free_prompts(s->cur_prompt);
4246 if (pktin->type == SSH1_SMSG_FAILURE) {
4247 if (flags & FLAG_VERBOSE)
4248 c_write_str(ssh, "Access denied\r\n");
4249 logevent("Authentication refused");
4250 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4251 bombout(("Strange packet received, type %d", pktin->type));
4257 if (s->publickey_blob) {
4258 sfree(s->publickey_blob);
4259 sfree(s->publickey_comment);
4262 logevent("Authentication successful");
4267 static void ssh_channel_try_eof(struct ssh_channel *c)
4270 assert(c->pending_eof); /* precondition for calling us */
4272 return; /* can't close: not even opened yet */
4273 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4274 return; /* can't send EOF: pending outgoing data */
4276 c->pending_eof = FALSE; /* we're about to send it */
4277 if (ssh->version == 1) {
4278 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4280 c->closes |= CLOSES_SENT_EOF;
4282 struct Packet *pktout;
4283 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4284 ssh2_pkt_adduint32(pktout, c->remoteid);
4285 ssh2_pkt_send(ssh, pktout);
4286 c->closes |= CLOSES_SENT_EOF;
4287 ssh2_channel_check_close(c);
4291 void sshfwd_write_eof(struct ssh_channel *c)
4295 if (ssh->state == SSH_STATE_CLOSED)
4298 if (c->closes & CLOSES_SENT_EOF)
4301 c->pending_eof = TRUE;
4302 ssh_channel_try_eof(c);
4305 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4309 if (ssh->state == SSH_STATE_CLOSED)
4314 x11_close(c->u.x11.s);
4315 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4319 case CHAN_SOCKDATA_DORMANT:
4320 pfd_close(c->u.pfd.s);
4321 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4324 c->type = CHAN_ZOMBIE;
4325 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4327 ssh2_channel_check_close(c);
4330 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4334 if (ssh->state == SSH_STATE_CLOSED)
4337 if (ssh->version == 1) {
4338 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4339 PKT_INT, c->remoteid,
4340 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
4341 PKTT_OTHER, PKT_END);
4343 * In SSH-1 we can return 0 here - implying that forwarded
4344 * connections are never individually throttled - because
4345 * the only circumstance that can cause throttling will be
4346 * the whole SSH connection backing up, in which case
4347 * _everything_ will be throttled as a whole.
4351 ssh2_add_channel_data(c, buf, len);
4352 return ssh2_try_send(c);
4356 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4361 if (ssh->state == SSH_STATE_CLOSED)
4364 if (ssh->version == 1) {
4365 buflimit = SSH1_BUFFER_LIMIT;
4367 buflimit = c->v.v2.locmaxwin;
4368 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4370 if (c->throttling_conn && bufsize <= buflimit) {
4371 c->throttling_conn = 0;
4372 ssh_throttle_conn(ssh, -1);
4376 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4378 struct queued_handler *qh = ssh->qhead;
4382 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4385 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4386 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4389 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4390 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4394 ssh->qhead = qh->next;
4396 if (ssh->qhead->msg1 > 0) {
4397 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4398 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4400 if (ssh->qhead->msg2 > 0) {
4401 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4402 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4405 ssh->qhead = ssh->qtail = NULL;
4408 qh->handler(ssh, pktin, qh->ctx);
4413 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4414 chandler_fn_t handler, void *ctx)
4416 struct queued_handler *qh;
4418 qh = snew(struct queued_handler);
4421 qh->handler = handler;
4425 if (ssh->qtail == NULL) {
4429 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4430 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4433 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4434 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4437 ssh->qtail->next = qh;
4442 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4444 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4446 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4447 SSH2_MSG_REQUEST_SUCCESS)) {
4448 logeventf(ssh, "Remote port forwarding from %s enabled",
4451 logeventf(ssh, "Remote port forwarding from %s refused",
4454 rpf = del234(ssh->rportfwds, pf);
4456 pf->pfrec->remote = NULL;
4461 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4463 struct ssh_portfwd *epf;
4467 if (!ssh->portfwds) {
4468 ssh->portfwds = newtree234(ssh_portcmp);
4471 * Go through the existing port forwardings and tag them
4472 * with status==DESTROY. Any that we want to keep will be
4473 * re-enabled (status==KEEP) as we go through the
4474 * configuration and find out which bits are the same as
4477 struct ssh_portfwd *epf;
4479 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4480 epf->status = DESTROY;
4483 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4485 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4486 char *kp, *kp2, *vp, *vp2;
4487 char address_family, type;
4488 int sport,dport,sserv,dserv;
4489 char *sports, *dports, *saddr, *host;
4493 address_family = 'A';
4495 if (*kp == 'A' || *kp == '4' || *kp == '6')
4496 address_family = *kp++;
4497 if (*kp == 'L' || *kp == 'R')
4500 if ((kp2 = strchr(kp, ':')) != NULL) {
4502 * There's a colon in the middle of the source port
4503 * string, which means that the part before it is
4504 * actually a source address.
4506 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4512 sport = atoi(sports);
4516 sport = net_service_lookup(sports);
4518 logeventf(ssh, "Service lookup failed for source"
4519 " port \"%s\"", sports);
4523 if (type == 'L' && !strcmp(val, "D")) {
4524 /* dynamic forwarding */
4531 /* ordinary forwarding */
4533 vp2 = vp + strcspn(vp, ":");
4534 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4538 dport = atoi(dports);
4542 dport = net_service_lookup(dports);
4544 logeventf(ssh, "Service lookup failed for destination"
4545 " port \"%s\"", dports);
4550 if (sport && dport) {
4551 /* Set up a description of the source port. */
4552 struct ssh_portfwd *pfrec, *epfrec;
4554 pfrec = snew(struct ssh_portfwd);
4556 pfrec->saddr = saddr;
4557 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4558 pfrec->sport = sport;
4559 pfrec->daddr = host;
4560 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4561 pfrec->dport = dport;
4562 pfrec->local = NULL;
4563 pfrec->remote = NULL;
4564 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4565 address_family == '6' ? ADDRTYPE_IPV6 :
4568 epfrec = add234(ssh->portfwds, pfrec);
4569 if (epfrec != pfrec) {
4570 if (epfrec->status == DESTROY) {
4572 * We already have a port forwarding up and running
4573 * with precisely these parameters. Hence, no need
4574 * to do anything; simply re-tag the existing one
4577 epfrec->status = KEEP;
4580 * Anything else indicates that there was a duplicate
4581 * in our input, which we'll silently ignore.
4583 free_portfwd(pfrec);
4585 pfrec->status = CREATE;
4594 * Now go through and destroy any port forwardings which were
4597 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4598 if (epf->status == DESTROY) {
4601 message = dupprintf("%s port forwarding from %s%s%d",
4602 epf->type == 'L' ? "local" :
4603 epf->type == 'R' ? "remote" : "dynamic",
4604 epf->saddr ? epf->saddr : "",
4605 epf->saddr ? ":" : "",
4608 if (epf->type != 'D') {
4609 char *msg2 = dupprintf("%s to %s:%d", message,
4610 epf->daddr, epf->dport);
4615 logeventf(ssh, "Cancelling %s", message);
4618 /* epf->remote or epf->local may be NULL if setting up a
4619 * forwarding failed. */
4621 struct ssh_rportfwd *rpf = epf->remote;
4622 struct Packet *pktout;
4625 * Cancel the port forwarding at the server
4628 if (ssh->version == 1) {
4630 * We cannot cancel listening ports on the
4631 * server side in SSH-1! There's no message
4632 * to support it. Instead, we simply remove
4633 * the rportfwd record from the local end
4634 * so that any connections the server tries
4635 * to make on it are rejected.
4638 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4639 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4640 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4642 ssh2_pkt_addstring(pktout, epf->saddr);
4643 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4644 /* XXX: rport_acceptall may not represent
4645 * what was used to open the original connection,
4646 * since it's reconfigurable. */
4647 ssh2_pkt_addstring(pktout, "");
4649 ssh2_pkt_addstring(pktout, "localhost");
4651 ssh2_pkt_adduint32(pktout, epf->sport);
4652 ssh2_pkt_send(ssh, pktout);
4655 del234(ssh->rportfwds, rpf);
4657 } else if (epf->local) {
4658 pfd_terminate(epf->local);
4661 delpos234(ssh->portfwds, i);
4663 i--; /* so we don't skip one in the list */
4667 * And finally, set up any new port forwardings (status==CREATE).
4669 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4670 if (epf->status == CREATE) {
4671 char *sportdesc, *dportdesc;
4672 sportdesc = dupprintf("%s%s%s%s%d%s",
4673 epf->saddr ? epf->saddr : "",
4674 epf->saddr ? ":" : "",
4675 epf->sserv ? epf->sserv : "",
4676 epf->sserv ? "(" : "",
4678 epf->sserv ? ")" : "");
4679 if (epf->type == 'D') {
4682 dportdesc = dupprintf("%s:%s%s%d%s",
4684 epf->dserv ? epf->dserv : "",
4685 epf->dserv ? "(" : "",
4687 epf->dserv ? ")" : "");
4690 if (epf->type == 'L') {
4691 const char *err = pfd_addforward(epf->daddr, epf->dport,
4692 epf->saddr, epf->sport,
4695 epf->addressfamily);
4697 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4698 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4699 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4700 sportdesc, dportdesc,
4701 err ? " failed: " : "", err ? err : "");
4702 } else if (epf->type == 'D') {
4703 const char *err = pfd_addforward(NULL, -1,
4704 epf->saddr, epf->sport,
4707 epf->addressfamily);
4709 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4710 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4711 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4713 err ? " failed: " : "", err ? err : "");
4715 struct ssh_rportfwd *pf;
4718 * Ensure the remote port forwardings tree exists.
4720 if (!ssh->rportfwds) {
4721 if (ssh->version == 1)
4722 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4724 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4727 pf = snew(struct ssh_rportfwd);
4728 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4729 pf->dhost[lenof(pf->dhost)-1] = '\0';
4730 pf->dport = epf->dport;
4731 pf->sport = epf->sport;
4732 if (add234(ssh->rportfwds, pf) != pf) {
4733 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4734 epf->daddr, epf->dport);
4737 logeventf(ssh, "Requesting remote port %s"
4738 " forward to %s", sportdesc, dportdesc);
4740 pf->sportdesc = sportdesc;
4745 if (ssh->version == 1) {
4746 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4747 PKT_INT, epf->sport,
4748 PKT_STR, epf->daddr,
4749 PKT_INT, epf->dport,
4751 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4753 ssh_rportfwd_succfail, pf);
4755 struct Packet *pktout;
4756 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4757 ssh2_pkt_addstring(pktout, "tcpip-forward");
4758 ssh2_pkt_addbool(pktout, 1);/* want reply */
4760 ssh2_pkt_addstring(pktout, epf->saddr);
4761 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4762 ssh2_pkt_addstring(pktout, "");
4764 ssh2_pkt_addstring(pktout, "localhost");
4766 ssh2_pkt_adduint32(pktout, epf->sport);
4767 ssh2_pkt_send(ssh, pktout);
4769 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4770 SSH2_MSG_REQUEST_FAILURE,
4771 ssh_rportfwd_succfail, pf);
4780 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4783 int stringlen, bufsize;
4785 ssh_pkt_getstring(pktin, &string, &stringlen);
4786 if (string == NULL) {
4787 bombout(("Incoming terminal data packet was badly formed"));
4791 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4793 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4794 ssh->v1_stdout_throttling = 1;
4795 ssh_throttle_conn(ssh, +1);
4799 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4801 /* Remote side is trying to open a channel to talk to our
4802 * X-Server. Give them back a local channel number. */
4803 struct ssh_channel *c;
4804 int remoteid = ssh_pkt_getuint32(pktin);
4806 logevent("Received X11 connect request");
4807 /* Refuse if X11 forwarding is disabled. */
4808 if (!ssh->X11_fwd_enabled) {
4809 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4810 PKT_INT, remoteid, PKT_END);
4811 logevent("Rejected X11 connect request");
4813 c = snew(struct ssh_channel);
4816 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4817 NULL, -1, ssh->conf) != NULL) {
4818 logevent("Opening X11 forward connection failed");
4820 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4821 PKT_INT, remoteid, PKT_END);
4824 ("Opening X11 forward connection succeeded");
4825 c->remoteid = remoteid;
4826 c->halfopen = FALSE;
4827 c->localid = alloc_channel_id(ssh);
4829 c->pending_eof = FALSE;
4830 c->throttling_conn = 0;
4831 c->type = CHAN_X11; /* identify channel type */
4832 add234(ssh->channels, c);
4833 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4834 PKT_INT, c->remoteid, PKT_INT,
4835 c->localid, PKT_END);
4836 logevent("Opened X11 forward channel");
4841 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4843 /* Remote side is trying to open a channel to talk to our
4844 * agent. Give them back a local channel number. */
4845 struct ssh_channel *c;
4846 int remoteid = ssh_pkt_getuint32(pktin);
4848 /* Refuse if agent forwarding is disabled. */
4849 if (!ssh->agentfwd_enabled) {
4850 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4851 PKT_INT, remoteid, PKT_END);
4853 c = snew(struct ssh_channel);
4855 c->remoteid = remoteid;
4856 c->halfopen = FALSE;
4857 c->localid = alloc_channel_id(ssh);
4859 c->pending_eof = FALSE;
4860 c->throttling_conn = 0;
4861 c->type = CHAN_AGENT; /* identify channel type */
4862 c->u.a.lensofar = 0;
4863 c->u.a.message = NULL;
4864 c->u.a.outstanding_requests = 0;
4865 add234(ssh->channels, c);
4866 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4867 PKT_INT, c->remoteid, PKT_INT, c->localid,
4872 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4874 /* Remote side is trying to open a channel to talk to a
4875 * forwarded port. Give them back a local channel number. */
4876 struct ssh_rportfwd pf, *pfp;
4882 remoteid = ssh_pkt_getuint32(pktin);
4883 ssh_pkt_getstring(pktin, &host, &hostsize);
4884 port = ssh_pkt_getuint32(pktin);
4886 if (hostsize >= lenof(pf.dhost))
4887 hostsize = lenof(pf.dhost)-1;
4888 memcpy(pf.dhost, host, hostsize);
4889 pf.dhost[hostsize] = '\0';
4891 pfp = find234(ssh->rportfwds, &pf, NULL);
4894 logeventf(ssh, "Rejected remote port open request for %s:%d",
4896 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4897 PKT_INT, remoteid, PKT_END);
4899 struct ssh_channel *c = snew(struct ssh_channel);
4902 logeventf(ssh, "Received remote port open request for %s:%d",
4904 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4905 c, ssh->conf, pfp->pfrec->addressfamily);
4907 logeventf(ssh, "Port open failed: %s", e);
4909 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4910 PKT_INT, remoteid, PKT_END);
4912 c->remoteid = remoteid;
4913 c->halfopen = FALSE;
4914 c->localid = alloc_channel_id(ssh);
4916 c->pending_eof = FALSE;
4917 c->throttling_conn = 0;
4918 c->type = CHAN_SOCKDATA; /* identify channel type */
4919 add234(ssh->channels, c);
4920 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4921 PKT_INT, c->remoteid, PKT_INT,
4922 c->localid, PKT_END);
4923 logevent("Forwarded port opened successfully");
4928 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4930 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4931 unsigned int localid = ssh_pkt_getuint32(pktin);
4932 struct ssh_channel *c;
4934 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4935 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4936 c->remoteid = localid;
4937 c->halfopen = FALSE;
4938 c->type = CHAN_SOCKDATA;
4939 c->throttling_conn = 0;
4940 pfd_confirm(c->u.pfd.s);
4943 if (c && c->pending_eof) {
4945 * We have a pending close on this channel,
4946 * which we decided on before the server acked
4947 * the channel open. So now we know the
4948 * remoteid, we can close it again.
4950 ssh_channel_try_eof(c);
4954 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4956 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4957 struct ssh_channel *c;
4959 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4960 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4961 logevent("Forwarded connection refused by server");
4962 pfd_close(c->u.pfd.s);
4963 del234(ssh->channels, c);
4968 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4970 /* Remote side closes a channel. */
4971 unsigned i = ssh_pkt_getuint32(pktin);
4972 struct ssh_channel *c;
4973 c = find234(ssh->channels, &i, ssh_channelfind);
4974 if (c && !c->halfopen) {
4976 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
4977 !(c->closes & CLOSES_RCVD_EOF)) {
4979 * Received CHANNEL_CLOSE, which we translate into
4982 int send_close = FALSE;
4984 c->closes |= CLOSES_RCVD_EOF;
4989 x11_send_eof(c->u.x11.s);
4995 pfd_send_eof(c->u.pfd.s);
5004 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5005 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5007 c->closes |= CLOSES_SENT_EOF;
5011 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5012 !(c->closes & CLOSES_RCVD_CLOSE)) {
5014 if (!(c->closes & CLOSES_SENT_EOF)) {
5015 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5016 " for which we never sent CHANNEL_CLOSE\n", i));
5019 c->closes |= CLOSES_RCVD_CLOSE;
5022 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5023 !(c->closes & CLOSES_SENT_CLOSE)) {
5024 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5025 PKT_INT, c->remoteid, PKT_END);
5026 c->closes |= CLOSES_SENT_CLOSE;
5029 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5030 ssh_channel_destroy(c);
5032 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5033 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5034 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5039 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5041 /* Data sent down one of our channels. */
5042 int i = ssh_pkt_getuint32(pktin);
5045 struct ssh_channel *c;
5047 ssh_pkt_getstring(pktin, &p, &len);
5049 c = find234(ssh->channels, &i, ssh_channelfind);
5054 bufsize = x11_send(c->u.x11.s, p, len);
5057 bufsize = pfd_send(c->u.pfd.s, p, len);
5060 /* Data for an agent message. Buffer it. */
5062 if (c->u.a.lensofar < 4) {
5063 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5064 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5068 c->u.a.lensofar += l;
5070 if (c->u.a.lensofar == 4) {
5072 4 + GET_32BIT(c->u.a.msglen);
5073 c->u.a.message = snewn(c->u.a.totallen,
5075 memcpy(c->u.a.message, c->u.a.msglen, 4);
5077 if (c->u.a.lensofar >= 4 && len > 0) {
5079 min(c->u.a.totallen - c->u.a.lensofar,
5081 memcpy(c->u.a.message + c->u.a.lensofar, p,
5085 c->u.a.lensofar += l;
5087 if (c->u.a.lensofar == c->u.a.totallen) {
5090 c->u.a.outstanding_requests++;
5091 if (agent_query(c->u.a.message,
5094 ssh_agentf_callback, c))
5095 ssh_agentf_callback(c, reply, replylen);
5096 sfree(c->u.a.message);
5097 c->u.a.lensofar = 0;
5100 bufsize = 0; /* agent channels never back up */
5103 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5104 c->throttling_conn = 1;
5105 ssh_throttle_conn(ssh, +1);
5110 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5112 ssh->exitcode = ssh_pkt_getuint32(pktin);
5113 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5114 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5116 * In case `helpful' firewalls or proxies tack
5117 * extra human-readable text on the end of the
5118 * session which we might mistake for another
5119 * encrypted packet, we close the session once
5120 * we've sent EXIT_CONFIRMATION.
5122 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5125 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5126 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5128 struct Packet *pktout = (struct Packet *)data;
5130 unsigned int arg = 0;
5131 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5132 if (i == lenof(ssh_ttymodes)) return;
5133 switch (ssh_ttymodes[i].type) {
5135 arg = ssh_tty_parse_specchar(val);
5138 arg = ssh_tty_parse_boolean(val);
5141 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5142 ssh2_pkt_addbyte(pktout, arg);
5146 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5147 struct Packet *pktin)
5149 crBegin(ssh->do_ssh1_connection_crstate);
5151 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5152 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5153 ssh1_smsg_stdout_stderr_data;
5155 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5156 ssh1_msg_channel_open_confirmation;
5157 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5158 ssh1_msg_channel_open_failure;
5159 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5160 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5161 ssh1_msg_channel_close;
5162 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5163 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5165 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
5166 logevent("Requesting agent forwarding");
5167 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5171 if (pktin->type != SSH1_SMSG_SUCCESS
5172 && pktin->type != SSH1_SMSG_FAILURE) {
5173 bombout(("Protocol confusion"));
5175 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5176 logevent("Agent forwarding refused");
5178 logevent("Agent forwarding enabled");
5179 ssh->agentfwd_enabled = TRUE;
5180 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5184 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5185 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5186 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
5187 logevent("Requesting X11 forwarding");
5189 * Note that while we blank the X authentication data here, we don't
5190 * take any special action to blank the start of an X11 channel,
5191 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5192 * without having session blanking enabled is likely to leak your
5193 * cookie into the log.
5195 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5196 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5197 PKT_STR, ssh->x11disp->remoteauthprotoname,
5199 PKT_STR, ssh->x11disp->remoteauthdatastring,
5201 PKT_INT, ssh->x11disp->screennum,
5204 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5205 PKT_STR, ssh->x11disp->remoteauthprotoname,
5207 PKT_STR, ssh->x11disp->remoteauthdatastring,
5214 if (pktin->type != SSH1_SMSG_SUCCESS
5215 && pktin->type != SSH1_SMSG_FAILURE) {
5216 bombout(("Protocol confusion"));
5218 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5219 logevent("X11 forwarding refused");
5221 logevent("X11 forwarding enabled");
5222 ssh->X11_fwd_enabled = TRUE;
5223 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5227 ssh_setup_portfwd(ssh, ssh->conf);
5228 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5230 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5232 /* Unpick the terminal-speed string. */
5233 /* XXX perhaps we should allow no speeds to be sent. */
5234 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5235 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5236 /* Send the pty request. */
5237 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5238 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5239 ssh_pkt_adduint32(pkt, ssh->term_height);
5240 ssh_pkt_adduint32(pkt, ssh->term_width);
5241 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5242 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5243 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5244 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5245 ssh_pkt_adduint32(pkt, ssh->ispeed);
5246 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5247 ssh_pkt_adduint32(pkt, ssh->ospeed);
5248 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5250 ssh->state = SSH_STATE_INTERMED;
5254 if (pktin->type != SSH1_SMSG_SUCCESS
5255 && pktin->type != SSH1_SMSG_FAILURE) {
5256 bombout(("Protocol confusion"));
5258 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5259 c_write_str(ssh, "Server refused to allocate pty\r\n");
5260 ssh->editing = ssh->echoing = 1;
5262 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5263 ssh->ospeed, ssh->ispeed);
5264 ssh->got_pty = TRUE;
5267 ssh->editing = ssh->echoing = 1;
5270 if (conf_get_int(ssh->conf, CONF_compression)) {
5271 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5275 if (pktin->type != SSH1_SMSG_SUCCESS
5276 && pktin->type != SSH1_SMSG_FAILURE) {
5277 bombout(("Protocol confusion"));
5279 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5280 c_write_str(ssh, "Server refused to compress\r\n");
5282 logevent("Started compression");
5283 ssh->v1_compressing = TRUE;
5284 ssh->cs_comp_ctx = zlib_compress_init();
5285 logevent("Initialised zlib (RFC1950) compression");
5286 ssh->sc_comp_ctx = zlib_decompress_init();
5287 logevent("Initialised zlib (RFC1950) decompression");
5291 * Start the shell or command.
5293 * Special case: if the first-choice command is an SSH-2
5294 * subsystem (hence not usable here) and the second choice
5295 * exists, we fall straight back to that.
5298 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5300 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5301 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5302 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5303 ssh->fallback_cmd = TRUE;
5306 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5308 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5309 logevent("Started session");
5312 ssh->state = SSH_STATE_SESSION;
5313 if (ssh->size_needed)
5314 ssh_size(ssh, ssh->term_width, ssh->term_height);
5315 if (ssh->eof_needed)
5316 ssh_special(ssh, TS_EOF);
5319 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5321 ssh->channels = newtree234(ssh_channelcmp);
5325 * By this point, most incoming packets are already being
5326 * handled by the dispatch table, and we need only pay
5327 * attention to the unusual ones.
5332 if (pktin->type == SSH1_SMSG_SUCCESS) {
5333 /* may be from EXEC_SHELL on some servers */
5334 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5335 /* may be from EXEC_SHELL on some servers
5336 * if no pty is available or in other odd cases. Ignore */
5338 bombout(("Strange packet received: type %d", pktin->type));
5343 int len = min(inlen, 512);
5344 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5345 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
5346 PKTT_OTHER, PKT_END);
5357 * Handle the top-level SSH-2 protocol.
5359 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5364 ssh_pkt_getstring(pktin, &msg, &msglen);
5365 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5368 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5370 /* log reason code in disconnect message */
5374 ssh_pkt_getstring(pktin, &msg, &msglen);
5375 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5378 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5380 /* Do nothing, because we're ignoring it! Duhh. */
5383 static void ssh1_protocol_setup(Ssh ssh)
5388 * Most messages are handled by the coroutines.
5390 for (i = 0; i < 256; i++)
5391 ssh->packet_dispatch[i] = NULL;
5394 * These special message types we install handlers for.
5396 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5397 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5398 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5401 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5402 struct Packet *pktin)
5404 unsigned char *in=(unsigned char*)vin;
5405 if (ssh->state == SSH_STATE_CLOSED)
5408 if (pktin && ssh->packet_dispatch[pktin->type]) {
5409 ssh->packet_dispatch[pktin->type](ssh, pktin);
5413 if (!ssh->protocol_initial_phase_done) {
5414 if (do_ssh1_login(ssh, in, inlen, pktin))
5415 ssh->protocol_initial_phase_done = TRUE;
5420 do_ssh1_connection(ssh, in, inlen, pktin);
5424 * Utility routine for decoding comma-separated strings in KEXINIT.
5426 static int in_commasep_string(char *needle, char *haystack, int haylen)
5429 if (!needle || !haystack) /* protect against null pointers */
5431 needlen = strlen(needle);
5434 * Is it at the start of the string?
5436 if (haylen >= needlen && /* haystack is long enough */
5437 !memcmp(needle, haystack, needlen) && /* initial match */
5438 (haylen == needlen || haystack[needlen] == ',')
5439 /* either , or EOS follows */
5443 * If not, search for the next comma and resume after that.
5444 * If no comma found, terminate.
5446 while (haylen > 0 && *haystack != ',')
5447 haylen--, haystack++;
5450 haylen--, haystack++; /* skip over comma itself */
5455 * Similar routine for checking whether we have the first string in a list.
5457 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5460 if (!needle || !haystack) /* protect against null pointers */
5462 needlen = strlen(needle);
5464 * Is it at the start of the string?
5466 if (haylen >= needlen && /* haystack is long enough */
5467 !memcmp(needle, haystack, needlen) && /* initial match */
5468 (haylen == needlen || haystack[needlen] == ',')
5469 /* either , or EOS follows */
5477 * SSH-2 key creation method.
5478 * (Currently assumes 2 lots of any hash are sufficient to generate
5479 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5481 #define SSH2_MKKEY_ITERS (2)
5482 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5483 unsigned char *keyspace)
5485 const struct ssh_hash *h = ssh->kex->hash;
5487 /* First hlen bytes. */
5489 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5490 hash_mpint(h, s, K);
5491 h->bytes(s, H, h->hlen);
5492 h->bytes(s, &chr, 1);
5493 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5494 h->final(s, keyspace);
5495 /* Next hlen bytes. */
5497 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5498 hash_mpint(h, s, K);
5499 h->bytes(s, H, h->hlen);
5500 h->bytes(s, keyspace, h->hlen);
5501 h->final(s, keyspace + h->hlen);
5505 * Handle the SSH-2 transport layer.
5507 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5508 struct Packet *pktin)
5510 unsigned char *in = (unsigned char *)vin;
5511 struct do_ssh2_transport_state {
5513 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5514 Bignum p, g, e, f, K;
5517 int kex_init_value, kex_reply_value;
5518 const struct ssh_mac **maclist;
5520 const struct ssh2_cipher *cscipher_tobe;
5521 const struct ssh2_cipher *sccipher_tobe;
5522 const struct ssh_mac *csmac_tobe;
5523 const struct ssh_mac *scmac_tobe;
5524 const struct ssh_compress *cscomp_tobe;
5525 const struct ssh_compress *sccomp_tobe;
5526 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5527 int hostkeylen, siglen, rsakeylen;
5528 void *hkey; /* actual host key */
5529 void *rsakey; /* for RSA kex */
5530 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5531 int n_preferred_kex;
5532 const struct ssh_kexes *preferred_kex[KEX_MAX];
5533 int n_preferred_ciphers;
5534 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5535 const struct ssh_compress *preferred_comp;
5536 int userauth_succeeded; /* for delayed compression */
5537 int pending_compression;
5538 int got_session_id, activated_authconn;
5539 struct Packet *pktout;
5544 crState(do_ssh2_transport_state);
5548 s->cscipher_tobe = s->sccipher_tobe = NULL;
5549 s->csmac_tobe = s->scmac_tobe = NULL;
5550 s->cscomp_tobe = s->sccomp_tobe = NULL;
5552 s->got_session_id = s->activated_authconn = FALSE;
5553 s->userauth_succeeded = FALSE;
5554 s->pending_compression = FALSE;
5557 * Be prepared to work around the buggy MAC problem.
5559 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5560 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5562 s->maclist = macs, s->nmacs = lenof(macs);
5565 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5567 int i, j, k, commalist_started;
5570 * Set up the preferred key exchange. (NULL => warn below here)
5572 s->n_preferred_kex = 0;
5573 for (i = 0; i < KEX_MAX; i++) {
5574 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5576 s->preferred_kex[s->n_preferred_kex++] =
5577 &ssh_diffiehellman_gex;
5580 s->preferred_kex[s->n_preferred_kex++] =
5581 &ssh_diffiehellman_group14;
5584 s->preferred_kex[s->n_preferred_kex++] =
5585 &ssh_diffiehellman_group1;
5588 s->preferred_kex[s->n_preferred_kex++] =
5592 /* Flag for later. Don't bother if it's the last in
5594 if (i < KEX_MAX - 1) {
5595 s->preferred_kex[s->n_preferred_kex++] = NULL;
5602 * Set up the preferred ciphers. (NULL => warn below here)
5604 s->n_preferred_ciphers = 0;
5605 for (i = 0; i < CIPHER_MAX; i++) {
5606 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
5607 case CIPHER_BLOWFISH:
5608 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5611 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
5612 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5616 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5619 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5621 case CIPHER_ARCFOUR:
5622 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5625 /* Flag for later. Don't bother if it's the last in
5627 if (i < CIPHER_MAX - 1) {
5628 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5635 * Set up preferred compression.
5637 if (conf_get_int(ssh->conf, CONF_compression))
5638 s->preferred_comp = &ssh_zlib;
5640 s->preferred_comp = &ssh_comp_none;
5643 * Enable queueing of outgoing auth- or connection-layer
5644 * packets while we are in the middle of a key exchange.
5646 ssh->queueing = TRUE;
5649 * Flag that KEX is in progress.
5651 ssh->kex_in_progress = TRUE;
5654 * Construct and send our key exchange packet.
5656 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5657 for (i = 0; i < 16; i++)
5658 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5659 /* List key exchange algorithms. */
5660 ssh2_pkt_addstring_start(s->pktout);
5661 commalist_started = 0;
5662 for (i = 0; i < s->n_preferred_kex; i++) {
5663 const struct ssh_kexes *k = s->preferred_kex[i];
5664 if (!k) continue; /* warning flag */
5665 for (j = 0; j < k->nkexes; j++) {
5666 if (commalist_started)
5667 ssh2_pkt_addstring_str(s->pktout, ",");
5668 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5669 commalist_started = 1;
5672 /* List server host key algorithms. */
5673 if (!s->got_session_id) {
5675 * In the first key exchange, we list all the algorithms
5676 * we're prepared to cope with.
5678 ssh2_pkt_addstring_start(s->pktout);
5679 for (i = 0; i < lenof(hostkey_algs); i++) {
5680 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5681 if (i < lenof(hostkey_algs) - 1)
5682 ssh2_pkt_addstring_str(s->pktout, ",");
5686 * In subsequent key exchanges, we list only the kex
5687 * algorithm that was selected in the first key exchange,
5688 * so that we keep getting the same host key and hence
5689 * don't have to interrupt the user's session to ask for
5693 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
5695 /* List encryption algorithms (client->server then server->client). */
5696 for (k = 0; k < 2; k++) {
5697 ssh2_pkt_addstring_start(s->pktout);
5698 commalist_started = 0;
5699 for (i = 0; i < s->n_preferred_ciphers; i++) {
5700 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5701 if (!c) continue; /* warning flag */
5702 for (j = 0; j < c->nciphers; j++) {
5703 if (commalist_started)
5704 ssh2_pkt_addstring_str(s->pktout, ",");
5705 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5706 commalist_started = 1;
5710 /* List MAC algorithms (client->server then server->client). */
5711 for (j = 0; j < 2; j++) {
5712 ssh2_pkt_addstring_start(s->pktout);
5713 for (i = 0; i < s->nmacs; i++) {
5714 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5715 if (i < s->nmacs - 1)
5716 ssh2_pkt_addstring_str(s->pktout, ",");
5719 /* List client->server compression algorithms,
5720 * then server->client compression algorithms. (We use the
5721 * same set twice.) */
5722 for (j = 0; j < 2; j++) {
5723 ssh2_pkt_addstring_start(s->pktout);
5724 assert(lenof(compressions) > 1);
5725 /* Prefer non-delayed versions */
5726 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5727 /* We don't even list delayed versions of algorithms until
5728 * they're allowed to be used, to avoid a race. See the end of
5730 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
5731 ssh2_pkt_addstring_str(s->pktout, ",");
5732 ssh2_pkt_addstring_str(s->pktout,
5733 s->preferred_comp->delayed_name);
5735 for (i = 0; i < lenof(compressions); i++) {
5736 const struct ssh_compress *c = compressions[i];
5737 if (c != s->preferred_comp) {
5738 ssh2_pkt_addstring_str(s->pktout, ",");
5739 ssh2_pkt_addstring_str(s->pktout, c->name);
5740 if (s->userauth_succeeded && c->delayed_name) {
5741 ssh2_pkt_addstring_str(s->pktout, ",");
5742 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5747 /* List client->server languages. Empty list. */
5748 ssh2_pkt_addstring_start(s->pktout);
5749 /* List server->client languages. Empty list. */
5750 ssh2_pkt_addstring_start(s->pktout);
5751 /* First KEX packet does _not_ follow, because we're not that brave. */
5752 ssh2_pkt_addbool(s->pktout, FALSE);
5754 ssh2_pkt_adduint32(s->pktout, 0);
5757 s->our_kexinitlen = s->pktout->length - 5;
5758 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5759 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5761 ssh2_pkt_send_noqueue(ssh, s->pktout);
5764 crWaitUntilV(pktin);
5767 * Now examine the other side's KEXINIT to see what we're up
5771 char *str, *preferred;
5774 if (pktin->type != SSH2_MSG_KEXINIT) {
5775 bombout(("expected key exchange packet from server"));
5779 ssh->hostkey = NULL;
5780 s->cscipher_tobe = NULL;
5781 s->sccipher_tobe = NULL;
5782 s->csmac_tobe = NULL;
5783 s->scmac_tobe = NULL;
5784 s->cscomp_tobe = NULL;
5785 s->sccomp_tobe = NULL;
5786 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5788 pktin->savedpos += 16; /* skip garbage cookie */
5789 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5792 for (i = 0; i < s->n_preferred_kex; i++) {
5793 const struct ssh_kexes *k = s->preferred_kex[i];
5797 for (j = 0; j < k->nkexes; j++) {
5798 if (!preferred) preferred = k->list[j]->name;
5799 if (in_commasep_string(k->list[j]->name, str, len)) {
5800 ssh->kex = k->list[j];
5809 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5810 str ? str : "(null)"));
5814 * Note that the server's guess is considered wrong if it doesn't match
5815 * the first algorithm in our list, even if it's still the algorithm
5818 s->guessok = first_in_commasep_string(preferred, str, len);
5819 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5820 for (i = 0; i < lenof(hostkey_algs); i++) {
5821 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5822 ssh->hostkey = hostkey_algs[i];
5826 if (!ssh->hostkey) {
5827 bombout(("Couldn't agree a host key algorithm (available: %s)",
5828 str ? str : "(null)"));
5832 s->guessok = s->guessok &&
5833 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5834 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5835 for (i = 0; i < s->n_preferred_ciphers; i++) {
5836 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5838 s->warn_cscipher = TRUE;
5840 for (j = 0; j < c->nciphers; j++) {
5841 if (in_commasep_string(c->list[j]->name, str, len)) {
5842 s->cscipher_tobe = c->list[j];
5847 if (s->cscipher_tobe)
5850 if (!s->cscipher_tobe) {
5851 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5852 str ? str : "(null)"));
5856 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5857 for (i = 0; i < s->n_preferred_ciphers; i++) {
5858 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5860 s->warn_sccipher = TRUE;
5862 for (j = 0; j < c->nciphers; j++) {
5863 if (in_commasep_string(c->list[j]->name, str, len)) {
5864 s->sccipher_tobe = c->list[j];
5869 if (s->sccipher_tobe)
5872 if (!s->sccipher_tobe) {
5873 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5874 str ? str : "(null)"));
5878 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5879 for (i = 0; i < s->nmacs; i++) {
5880 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5881 s->csmac_tobe = s->maclist[i];
5885 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5886 for (i = 0; i < s->nmacs; i++) {
5887 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5888 s->scmac_tobe = s->maclist[i];
5892 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5893 for (i = 0; i < lenof(compressions) + 1; i++) {
5894 const struct ssh_compress *c =
5895 i == 0 ? s->preferred_comp : compressions[i - 1];
5896 if (in_commasep_string(c->name, str, len)) {
5899 } else if (in_commasep_string(c->delayed_name, str, len)) {
5900 if (s->userauth_succeeded) {
5904 s->pending_compression = TRUE; /* try this later */
5908 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5909 for (i = 0; i < lenof(compressions) + 1; i++) {
5910 const struct ssh_compress *c =
5911 i == 0 ? s->preferred_comp : compressions[i - 1];
5912 if (in_commasep_string(c->name, str, len)) {
5915 } else if (in_commasep_string(c->delayed_name, str, len)) {
5916 if (s->userauth_succeeded) {
5920 s->pending_compression = TRUE; /* try this later */
5924 if (s->pending_compression) {
5925 logevent("Server supports delayed compression; "
5926 "will try this later");
5928 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5929 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5930 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5932 ssh->exhash = ssh->kex->hash->init();
5933 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5934 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5935 hash_string(ssh->kex->hash, ssh->exhash,
5936 s->our_kexinit, s->our_kexinitlen);
5937 sfree(s->our_kexinit);
5938 if (pktin->length > 5)
5939 hash_string(ssh->kex->hash, ssh->exhash,
5940 pktin->data + 5, pktin->length - 5);
5943 ssh_set_frozen(ssh, 1);
5944 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5946 ssh_dialog_callback, ssh);
5947 if (s->dlgret < 0) {
5951 bombout(("Unexpected data from server while"
5952 " waiting for user response"));
5955 } while (pktin || inlen > 0);
5956 s->dlgret = ssh->user_response;
5958 ssh_set_frozen(ssh, 0);
5959 if (s->dlgret == 0) {
5960 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5966 if (s->warn_cscipher) {
5967 ssh_set_frozen(ssh, 1);
5968 s->dlgret = askalg(ssh->frontend,
5969 "client-to-server cipher",
5970 s->cscipher_tobe->name,
5971 ssh_dialog_callback, ssh);
5972 if (s->dlgret < 0) {
5976 bombout(("Unexpected data from server while"
5977 " waiting for user response"));
5980 } while (pktin || inlen > 0);
5981 s->dlgret = ssh->user_response;
5983 ssh_set_frozen(ssh, 0);
5984 if (s->dlgret == 0) {
5985 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5991 if (s->warn_sccipher) {
5992 ssh_set_frozen(ssh, 1);
5993 s->dlgret = askalg(ssh->frontend,
5994 "server-to-client cipher",
5995 s->sccipher_tobe->name,
5996 ssh_dialog_callback, ssh);
5997 if (s->dlgret < 0) {
6001 bombout(("Unexpected data from server while"
6002 " waiting for user response"));
6005 } while (pktin || inlen > 0);
6006 s->dlgret = ssh->user_response;
6008 ssh_set_frozen(ssh, 0);
6009 if (s->dlgret == 0) {
6010 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6016 if (s->ignorepkt) /* first_kex_packet_follows */
6017 crWaitUntilV(pktin); /* Ignore packet */
6020 if (ssh->kex->main_type == KEXTYPE_DH) {
6022 * Work out the number of bits of key we will need from the
6023 * key exchange. We start with the maximum key length of
6029 csbits = s->cscipher_tobe->keylen;
6030 scbits = s->sccipher_tobe->keylen;
6031 s->nbits = (csbits > scbits ? csbits : scbits);
6033 /* The keys only have hlen-bit entropy, since they're based on
6034 * a hash. So cap the key size at hlen bits. */
6035 if (s->nbits > ssh->kex->hash->hlen * 8)
6036 s->nbits = ssh->kex->hash->hlen * 8;
6039 * If we're doing Diffie-Hellman group exchange, start by
6040 * requesting a group.
6042 if (!ssh->kex->pdata) {
6043 logevent("Doing Diffie-Hellman group exchange");
6044 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6046 * Work out how big a DH group we will need to allow that
6049 s->pbits = 512 << ((s->nbits - 1) / 64);
6050 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6051 ssh2_pkt_adduint32(s->pktout, s->pbits);
6052 ssh2_pkt_send_noqueue(ssh, s->pktout);
6054 crWaitUntilV(pktin);
6055 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6056 bombout(("expected key exchange group packet from server"));
6059 s->p = ssh2_pkt_getmp(pktin);
6060 s->g = ssh2_pkt_getmp(pktin);
6061 if (!s->p || !s->g) {
6062 bombout(("unable to read mp-ints from incoming group packet"));
6065 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6066 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6067 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6069 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6070 ssh->kex_ctx = dh_setup_group(ssh->kex);
6071 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6072 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6073 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6074 ssh->kex->groupname);
6077 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6078 ssh->kex->hash->text_name);
6080 * Now generate and send e for Diffie-Hellman.
6082 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6083 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6084 s->pktout = ssh2_pkt_init(s->kex_init_value);
6085 ssh2_pkt_addmp(s->pktout, s->e);
6086 ssh2_pkt_send_noqueue(ssh, s->pktout);
6088 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6089 crWaitUntilV(pktin);
6090 if (pktin->type != s->kex_reply_value) {
6091 bombout(("expected key exchange reply packet from server"));
6094 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6095 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6096 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6097 s->f = ssh2_pkt_getmp(pktin);
6099 bombout(("unable to parse key exchange reply packet"));
6102 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6104 s->K = dh_find_K(ssh->kex_ctx, s->f);
6106 /* We assume everything from now on will be quick, and it might
6107 * involve user interaction. */
6108 set_busy_status(ssh->frontend, BUSY_NOT);
6110 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6111 if (!ssh->kex->pdata) {
6112 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6113 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6114 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6116 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6117 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6119 dh_cleanup(ssh->kex_ctx);
6121 if (!ssh->kex->pdata) {
6126 logeventf(ssh, "Doing RSA key exchange with hash %s",
6127 ssh->kex->hash->text_name);
6128 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6130 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6133 crWaitUntilV(pktin);
6134 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6135 bombout(("expected RSA public key packet from server"));
6139 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6140 hash_string(ssh->kex->hash, ssh->exhash,
6141 s->hostkeydata, s->hostkeylen);
6142 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6146 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6147 s->rsakeydata = snewn(s->rsakeylen, char);
6148 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6151 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6153 sfree(s->rsakeydata);
6154 bombout(("unable to parse RSA public key from server"));
6158 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6161 * Next, set up a shared secret K, of precisely KLEN -
6162 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6163 * RSA key modulus and HLEN is the bit length of the hash
6167 int klen = ssh_rsakex_klen(s->rsakey);
6168 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6170 unsigned char *kstr1, *kstr2, *outstr;
6171 int kstr1len, kstr2len, outstrlen;
6173 s->K = bn_power_2(nbits - 1);
6175 for (i = 0; i < nbits; i++) {
6177 byte = random_byte();
6179 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6183 * Encode this as an mpint.
6185 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6186 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6187 PUT_32BIT(kstr2, kstr1len);
6188 memcpy(kstr2 + 4, kstr1, kstr1len);
6191 * Encrypt it with the given RSA key.
6193 outstrlen = (klen + 7) / 8;
6194 outstr = snewn(outstrlen, unsigned char);
6195 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6196 outstr, outstrlen, s->rsakey);
6199 * And send it off in a return packet.
6201 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6202 ssh2_pkt_addstring_start(s->pktout);
6203 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6204 ssh2_pkt_send_noqueue(ssh, s->pktout);
6206 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6213 ssh_rsakex_freekey(s->rsakey);
6215 crWaitUntilV(pktin);
6216 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6217 sfree(s->rsakeydata);
6218 bombout(("expected signature packet from server"));
6222 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6224 sfree(s->rsakeydata);
6227 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6228 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6229 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6231 ssh->kex_ctx = NULL;
6234 debug(("Exchange hash is:\n"));
6235 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6239 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6240 (char *)s->exchange_hash,
6241 ssh->kex->hash->hlen)) {
6242 bombout(("Server's host key did not match the signature supplied"));
6246 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6247 if (!s->got_session_id) {
6249 * Authenticate remote host: verify host key. (We've already
6250 * checked the signature of the exchange hash.)
6252 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6253 ssh_set_frozen(ssh, 1);
6254 s->dlgret = verify_ssh_host_key(ssh->frontend,
6255 ssh->savedhost, ssh->savedport,
6256 ssh->hostkey->keytype, s->keystr,
6258 ssh_dialog_callback, ssh);
6259 if (s->dlgret < 0) {
6263 bombout(("Unexpected data from server while waiting"
6264 " for user host key response"));
6267 } while (pktin || inlen > 0);
6268 s->dlgret = ssh->user_response;
6270 ssh_set_frozen(ssh, 0);
6271 if (s->dlgret == 0) {
6272 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6276 logevent("Host key fingerprint is:");
6277 logevent(s->fingerprint);
6278 sfree(s->fingerprint);
6280 * Save this host key, to check against the one presented in
6281 * subsequent rekeys.
6283 ssh->hostkey_str = s->keystr;
6286 * In a rekey, we never present an interactive host key
6287 * verification request to the user. Instead, we simply
6288 * enforce that the key we're seeing this time is identical to
6289 * the one we saw before.
6291 if (strcmp(ssh->hostkey_str, s->keystr)) {
6292 bombout(("Host key was different in repeat key exchange"));
6297 ssh->hostkey->freekey(s->hkey);
6300 * The exchange hash from the very first key exchange is also
6301 * the session id, used in session key construction and
6304 if (!s->got_session_id) {
6305 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6306 memcpy(ssh->v2_session_id, s->exchange_hash,
6307 sizeof(s->exchange_hash));
6308 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6309 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6310 s->got_session_id = TRUE;
6314 * Send SSH2_MSG_NEWKEYS.
6316 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6317 ssh2_pkt_send_noqueue(ssh, s->pktout);
6318 ssh->outgoing_data_size = 0; /* start counting from here */
6321 * We've sent client NEWKEYS, so create and initialise
6322 * client-to-server session keys.
6324 if (ssh->cs_cipher_ctx)
6325 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6326 ssh->cscipher = s->cscipher_tobe;
6327 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6329 if (ssh->cs_mac_ctx)
6330 ssh->csmac->free_context(ssh->cs_mac_ctx);
6331 ssh->csmac = s->csmac_tobe;
6332 ssh->cs_mac_ctx = ssh->csmac->make_context();
6334 if (ssh->cs_comp_ctx)
6335 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6336 ssh->cscomp = s->cscomp_tobe;
6337 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6340 * Set IVs on client-to-server keys. Here we use the exchange
6341 * hash from the _first_ key exchange.
6344 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6345 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6346 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6347 assert((ssh->cscipher->keylen+7) / 8 <=
6348 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6349 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6350 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6351 assert(ssh->cscipher->blksize <=
6352 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6353 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6354 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6355 assert(ssh->csmac->len <=
6356 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6357 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6358 smemclr(keyspace, sizeof(keyspace));
6361 logeventf(ssh, "Initialised %.200s client->server encryption",
6362 ssh->cscipher->text_name);
6363 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6364 ssh->csmac->text_name);
6365 if (ssh->cscomp->text_name)
6366 logeventf(ssh, "Initialised %s compression",
6367 ssh->cscomp->text_name);
6370 * Now our end of the key exchange is complete, we can send all
6371 * our queued higher-layer packets.
6373 ssh->queueing = FALSE;
6374 ssh2_pkt_queuesend(ssh);
6377 * Expect SSH2_MSG_NEWKEYS from server.
6379 crWaitUntilV(pktin);
6380 if (pktin->type != SSH2_MSG_NEWKEYS) {
6381 bombout(("expected new-keys packet from server"));
6384 ssh->incoming_data_size = 0; /* start counting from here */
6387 * We've seen server NEWKEYS, so create and initialise
6388 * server-to-client session keys.
6390 if (ssh->sc_cipher_ctx)
6391 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6392 ssh->sccipher = s->sccipher_tobe;
6393 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6395 if (ssh->sc_mac_ctx)
6396 ssh->scmac->free_context(ssh->sc_mac_ctx);
6397 ssh->scmac = s->scmac_tobe;
6398 ssh->sc_mac_ctx = ssh->scmac->make_context();
6400 if (ssh->sc_comp_ctx)
6401 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6402 ssh->sccomp = s->sccomp_tobe;
6403 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6406 * Set IVs on server-to-client keys. Here we use the exchange
6407 * hash from the _first_ key exchange.
6410 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6411 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6412 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6413 assert((ssh->sccipher->keylen+7) / 8 <=
6414 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6415 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6416 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6417 assert(ssh->sccipher->blksize <=
6418 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6419 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6420 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6421 assert(ssh->scmac->len <=
6422 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6423 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6424 smemclr(keyspace, sizeof(keyspace));
6426 logeventf(ssh, "Initialised %.200s server->client encryption",
6427 ssh->sccipher->text_name);
6428 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6429 ssh->scmac->text_name);
6430 if (ssh->sccomp->text_name)
6431 logeventf(ssh, "Initialised %s decompression",
6432 ssh->sccomp->text_name);
6435 * Free shared secret.
6440 * Key exchange is over. Loop straight back round if we have a
6441 * deferred rekey reason.
6443 if (ssh->deferred_rekey_reason) {
6444 logevent(ssh->deferred_rekey_reason);
6446 ssh->deferred_rekey_reason = NULL;
6447 goto begin_key_exchange;
6451 * Otherwise, schedule a timer for our next rekey.
6453 ssh->kex_in_progress = FALSE;
6454 ssh->last_rekey = GETTICKCOUNT();
6455 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6456 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6460 * Now we're encrypting. Begin returning 1 to the protocol main
6461 * function so that other things can run on top of the
6462 * transport. If we ever see a KEXINIT, we must go back to the
6465 * We _also_ go back to the start if we see pktin==NULL and
6466 * inlen negative, because this is a special signal meaning
6467 * `initiate client-driven rekey', and `in' contains a message
6468 * giving the reason for the rekey.
6470 * inlen==-1 means always initiate a rekey;
6471 * inlen==-2 means that userauth has completed successfully and
6472 * we should consider rekeying (for delayed compression).
6474 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6475 (!pktin && inlen < 0))) {
6477 if (!ssh->protocol_initial_phase_done) {
6478 ssh->protocol_initial_phase_done = TRUE;
6480 * Allow authconn to initialise itself.
6482 do_ssh2_authconn(ssh, NULL, 0, NULL);
6487 logevent("Server initiated key re-exchange");
6491 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6492 * delayed compression, if it's available.
6494 * draft-miller-secsh-compression-delayed-00 says that you
6495 * negotiate delayed compression in the first key exchange, and
6496 * both sides start compressing when the server has sent
6497 * USERAUTH_SUCCESS. This has a race condition -- the server
6498 * can't know when the client has seen it, and thus which incoming
6499 * packets it should treat as compressed.
6501 * Instead, we do the initial key exchange without offering the
6502 * delayed methods, but note if the server offers them; when we
6503 * get here, if a delayed method was available that was higher
6504 * on our list than what we got, we initiate a rekey in which we
6505 * _do_ list the delayed methods (and hopefully get it as a
6506 * result). Subsequent rekeys will do the same.
6508 assert(!s->userauth_succeeded); /* should only happen once */
6509 s->userauth_succeeded = TRUE;
6510 if (!s->pending_compression)
6511 /* Can't see any point rekeying. */
6512 goto wait_for_rekey; /* this is utterly horrid */
6513 /* else fall through to rekey... */
6514 s->pending_compression = FALSE;
6517 * Now we've decided to rekey.
6519 * Special case: if the server bug is set that doesn't
6520 * allow rekeying, we give a different log message and
6521 * continue waiting. (If such a server _initiates_ a rekey,
6522 * we process it anyway!)
6524 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6525 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6527 /* Reset the counters, so that at least this message doesn't
6528 * hit the event log _too_ often. */
6529 ssh->outgoing_data_size = 0;
6530 ssh->incoming_data_size = 0;
6531 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6533 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6536 goto wait_for_rekey; /* this is still utterly horrid */
6538 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6541 goto begin_key_exchange;
6547 * Add data to an SSH-2 channel output buffer.
6549 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6552 bufchain_add(&c->v.v2.outbuffer, buf, len);
6556 * Attempt to send data on an SSH-2 channel.
6558 static int ssh2_try_send(struct ssh_channel *c)
6561 struct Packet *pktout;
6564 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6567 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6568 if ((unsigned)len > c->v.v2.remwindow)
6569 len = c->v.v2.remwindow;
6570 if ((unsigned)len > c->v.v2.remmaxpkt)
6571 len = c->v.v2.remmaxpkt;
6572 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6573 ssh2_pkt_adduint32(pktout, c->remoteid);
6574 ssh2_pkt_addstring_start(pktout);
6575 dont_log_data(ssh, pktout, PKTLOG_OMIT);
6576 ssh2_pkt_addstring_data(pktout, data, len);
6577 end_log_omission(ssh, pktout);
6578 ssh2_pkt_send(ssh, pktout);
6579 bufchain_consume(&c->v.v2.outbuffer, len);
6580 c->v.v2.remwindow -= len;
6584 * After having sent as much data as we can, return the amount
6587 ret = bufchain_size(&c->v.v2.outbuffer);
6590 * And if there's no data pending but we need to send an EOF, send
6593 if (!ret && c->pending_eof)
6594 ssh_channel_try_eof(c);
6599 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
6602 if (c->closes & CLOSES_SENT_EOF)
6603 return; /* don't send on channels we've EOFed */
6604 bufsize = ssh2_try_send(c);
6607 case CHAN_MAINSESSION:
6608 /* stdin need not receive an unthrottle
6609 * notification since it will be polled */
6612 x11_unthrottle(c->u.x11.s);
6615 /* agent sockets are request/response and need no
6616 * buffer management */
6619 pfd_unthrottle(c->u.pfd.s);
6626 * Set up most of a new ssh_channel for SSH-2.
6628 static void ssh2_channel_init(struct ssh_channel *c)
6631 c->localid = alloc_channel_id(ssh);
6633 c->pending_eof = FALSE;
6634 c->throttling_conn = FALSE;
6635 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
6636 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
6637 c->v.v2.chanreq_head = NULL;
6638 c->v.v2.throttle_state = UNTHROTTLED;
6639 bufchain_init(&c->v.v2.outbuffer);
6643 * Construct the common parts of a CHANNEL_OPEN.
6645 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
6647 struct Packet *pktout;
6649 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6650 ssh2_pkt_addstring(pktout, type);
6651 ssh2_pkt_adduint32(pktout, c->localid);
6652 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
6653 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6658 * CHANNEL_FAILURE doesn't come with any indication of what message
6659 * caused it, so we have to keep track of the outstanding
6660 * CHANNEL_REQUESTs ourselves.
6662 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
6663 cchandler_fn_t handler, void *ctx)
6665 struct outstanding_channel_request *ocr =
6666 snew(struct outstanding_channel_request);
6668 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6669 ocr->handler = handler;
6672 if (!c->v.v2.chanreq_head)
6673 c->v.v2.chanreq_head = ocr;
6675 c->v.v2.chanreq_tail->next = ocr;
6676 c->v.v2.chanreq_tail = ocr;
6680 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6681 * NULL then a reply will be requested and the handler will be called
6682 * when it arrives. The returned packet is ready to have any
6683 * request-specific data added and be sent. Note that if a handler is
6684 * provided, it's essential that the request actually be sent.
6686 * The handler will usually be passed the response packet in pktin.
6687 * If pktin is NULL, this means that no reply will ever be forthcoming
6688 * (e.g. because the entire connection is being destroyed) and the
6689 * handler should free any storage it's holding.
6691 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
6692 cchandler_fn_t handler, void *ctx)
6694 struct Packet *pktout;
6696 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6697 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6698 ssh2_pkt_adduint32(pktout, c->remoteid);
6699 ssh2_pkt_addstring(pktout, type);
6700 ssh2_pkt_addbool(pktout, handler != NULL);
6701 if (handler != NULL)
6702 ssh2_queue_chanreq_handler(c, handler, ctx);
6707 * Potentially enlarge the window on an SSH-2 channel.
6709 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
6711 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6716 * Never send WINDOW_ADJUST for a channel that the remote side has
6717 * already sent EOF on; there's no point, since it won't be
6718 * sending any more data anyway. Ditto if _we've_ already sent
6721 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6725 * If the remote end has a habit of ignoring maxpkt, limit the
6726 * window so that it has no choice (assuming it doesn't ignore the
6729 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6730 newwin = OUR_V2_MAXPKT;
6733 * Only send a WINDOW_ADJUST if there's significantly more window
6734 * available than the other end thinks there is. This saves us
6735 * sending a WINDOW_ADJUST for every character in a shell session.
6737 * "Significant" is arbitrarily defined as half the window size.
6739 if (newwin / 2 >= c->v.v2.locwindow) {
6740 struct Packet *pktout;
6744 * In order to keep track of how much window the client
6745 * actually has available, we'd like it to acknowledge each
6746 * WINDOW_ADJUST. We can't do that directly, so we accompany
6747 * it with a CHANNEL_REQUEST that has to be acknowledged.
6749 * This is only necessary if we're opening the window wide.
6750 * If we're not, then throughput is being constrained by
6751 * something other than the maximum window size anyway.
6753 if (newwin == c->v.v2.locmaxwin &&
6754 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
6755 up = snew(unsigned);
6756 *up = newwin - c->v.v2.locwindow;
6757 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
6758 ssh2_handle_winadj_response, up);
6759 ssh2_pkt_send(ssh, pktout);
6761 if (c->v.v2.throttle_state != UNTHROTTLED)
6762 c->v.v2.throttle_state = UNTHROTTLING;
6764 /* Pretend the WINDOW_ADJUST was acked immediately. */
6765 c->v.v2.remlocwin = newwin;
6766 c->v.v2.throttle_state = THROTTLED;
6768 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6769 ssh2_pkt_adduint32(pktout, c->remoteid);
6770 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6771 ssh2_pkt_send(ssh, pktout);
6772 c->v.v2.locwindow = newwin;
6777 * Find the channel associated with a message. If there's no channel,
6778 * or it's not properly open, make a noise about it and return NULL.
6780 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6782 unsigned localid = ssh_pkt_getuint32(pktin);
6783 struct ssh_channel *c;
6785 c = find234(ssh->channels, &localid, ssh_channelfind);
6787 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6788 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6789 char *buf = dupprintf("Received %s for %s channel %u",
6790 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6792 c ? "half-open" : "nonexistent", localid);
6793 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6800 static void ssh2_handle_winadj_response(struct ssh_channel *c,
6801 struct Packet *pktin, void *ctx)
6803 unsigned *sizep = ctx;
6806 * Winadj responses should always be failures. However, at least
6807 * one server ("boks_sshd") is known to return SUCCESS for channel
6808 * requests it's never heard of, such as "winadj@putty". Raised
6809 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6810 * life, we don't worry about what kind of response we got.
6813 c->v.v2.remlocwin += *sizep;
6816 * winadj messages are only sent when the window is fully open, so
6817 * if we get an ack of one, we know any pending unthrottle is
6820 if (c->v.v2.throttle_state == UNTHROTTLING)
6821 c->v.v2.throttle_state = UNTHROTTLED;
6824 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
6826 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
6827 struct outstanding_channel_request *ocr;
6830 ocr = c->v.v2.chanreq_head;
6832 ssh2_msg_unexpected(ssh, pktin);
6835 ocr->handler(c, pktin, ocr->ctx);
6836 c->v.v2.chanreq_head = ocr->next;
6839 * We may now initiate channel-closing procedures, if that
6840 * CHANNEL_REQUEST was the last thing outstanding before we send
6843 ssh2_channel_check_close(c);
6846 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6848 struct ssh_channel *c;
6849 c = ssh2_channel_msg(ssh, pktin);
6852 if (!(c->closes & CLOSES_SENT_EOF)) {
6853 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6854 ssh2_try_send_and_unthrottle(ssh, c);
6858 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6862 struct ssh_channel *c;
6863 c = ssh2_channel_msg(ssh, pktin);
6866 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6867 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6868 return; /* extended but not stderr */
6869 ssh_pkt_getstring(pktin, &data, &length);
6872 c->v.v2.locwindow -= length;
6873 c->v.v2.remlocwin -= length;
6875 case CHAN_MAINSESSION:
6877 from_backend(ssh->frontend, pktin->type ==
6878 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6882 bufsize = x11_send(c->u.x11.s, data, length);
6885 bufsize = pfd_send(c->u.pfd.s, data, length);
6888 while (length > 0) {
6889 if (c->u.a.lensofar < 4) {
6890 unsigned int l = min(4 - c->u.a.lensofar,
6892 memcpy(c->u.a.msglen + c->u.a.lensofar,
6896 c->u.a.lensofar += l;
6898 if (c->u.a.lensofar == 4) {
6900 4 + GET_32BIT(c->u.a.msglen);
6901 c->u.a.message = snewn(c->u.a.totallen,
6903 memcpy(c->u.a.message, c->u.a.msglen, 4);
6905 if (c->u.a.lensofar >= 4 && length > 0) {
6907 min(c->u.a.totallen - c->u.a.lensofar,
6909 memcpy(c->u.a.message + c->u.a.lensofar,
6913 c->u.a.lensofar += l;
6915 if (c->u.a.lensofar == c->u.a.totallen) {
6918 c->u.a.outstanding_requests++;
6919 if (agent_query(c->u.a.message,
6922 ssh_agentf_callback, c))
6923 ssh_agentf_callback(c, reply, replylen);
6924 sfree(c->u.a.message);
6925 c->u.a.message = NULL;
6926 c->u.a.lensofar = 0;
6933 * If it looks like the remote end hit the end of its window,
6934 * and we didn't want it to do that, think about using a
6937 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6938 c->v.v2.locmaxwin < 0x40000000)
6939 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6941 * If we are not buffering too much data,
6942 * enlarge the window again at the remote side.
6943 * If we are buffering too much, we may still
6944 * need to adjust the window if the server's
6947 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6948 c->v.v2.locmaxwin - bufsize : 0);
6950 * If we're either buffering way too much data, or if we're
6951 * buffering anything at all and we're in "simple" mode,
6952 * throttle the whole channel.
6954 if ((bufsize > c->v.v2.locmaxwin ||
6955 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
6956 !c->throttling_conn) {
6957 c->throttling_conn = 1;
6958 ssh_throttle_conn(ssh, +1);
6963 static void ssh_channel_destroy(struct ssh_channel *c)
6968 case CHAN_MAINSESSION:
6969 ssh->mainchan = NULL;
6970 update_specials_menu(ssh->frontend);
6973 if (c->u.x11.s != NULL)
6974 x11_close(c->u.x11.s);
6975 logevent("Forwarded X11 connection terminated");
6978 sfree(c->u.a.message);
6981 if (c->u.pfd.s != NULL)
6982 pfd_close(c->u.pfd.s);
6983 logevent("Forwarded port closed");
6987 del234(ssh->channels, c);
6988 if (ssh->version == 2) {
6989 bufchain_clear(&c->v.v2.outbuffer);
6990 assert(c->v.v2.chanreq_head == NULL);
6995 * See if that was the last channel left open.
6996 * (This is only our termination condition if we're
6997 * not running in -N mode.)
6999 if (ssh->version == 2 &&
7000 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7001 count234(ssh->channels) == 0) {
7003 * We used to send SSH_MSG_DISCONNECT here,
7004 * because I'd believed that _every_ conforming
7005 * SSH-2 connection had to end with a disconnect
7006 * being sent by at least one side; apparently
7007 * I was wrong and it's perfectly OK to
7008 * unceremoniously slam the connection shut
7009 * when you're done, and indeed OpenSSH feels
7010 * this is more polite than sending a
7011 * DISCONNECT. So now we don't.
7013 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7017 static void ssh2_channel_check_close(struct ssh_channel *c)
7020 struct Packet *pktout;
7024 * If we've sent out our own CHANNEL_OPEN but not yet seen
7025 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7026 * it's too early to be sending close messages of any kind.
7031 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7032 c->type == CHAN_ZOMBIE) &&
7033 !c->v.v2.chanreq_head &&
7034 !(c->closes & CLOSES_SENT_CLOSE)) {
7036 * We have both sent and received EOF (or the channel is a
7037 * zombie), and we have no outstanding channel requests, which
7038 * means the channel is in final wind-up. But we haven't sent
7039 * CLOSE, so let's do so now.
7041 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7042 ssh2_pkt_adduint32(pktout, c->remoteid);
7043 ssh2_pkt_send(ssh, pktout);
7044 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7047 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7048 assert(c->v.v2.chanreq_head == NULL);
7050 * We have both sent and received CLOSE, which means we're
7051 * completely done with the channel.
7053 ssh_channel_destroy(c);
7057 static void ssh2_channel_got_eof(struct ssh_channel *c)
7059 if (c->closes & CLOSES_RCVD_EOF)
7060 return; /* already seen EOF */
7061 c->closes |= CLOSES_RCVD_EOF;
7063 if (c->type == CHAN_X11) {
7064 x11_send_eof(c->u.x11.s);
7065 } else if (c->type == CHAN_AGENT) {
7066 if (c->u.a.outstanding_requests == 0) {
7067 /* Manufacture an outgoing EOF in response to the incoming one. */
7068 sshfwd_write_eof(c);
7070 } else if (c->type == CHAN_SOCKDATA) {
7071 pfd_send_eof(c->u.pfd.s);
7072 } else if (c->type == CHAN_MAINSESSION) {
7075 if (!ssh->sent_console_eof &&
7076 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7078 * Either from_backend_eof told us that the front end
7079 * wants us to close the outgoing side of the connection
7080 * as soon as we see EOF from the far end, or else we've
7081 * unilaterally decided to do that because we've allocated
7082 * a remote pty and hence EOF isn't a particularly
7083 * meaningful concept.
7085 sshfwd_write_eof(c);
7087 ssh->sent_console_eof = TRUE;
7090 ssh2_channel_check_close(c);
7093 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7095 struct ssh_channel *c;
7097 c = ssh2_channel_msg(ssh, pktin);
7100 ssh2_channel_got_eof(c);
7103 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7105 struct ssh_channel *c;
7107 c = ssh2_channel_msg(ssh, pktin);
7112 * When we receive CLOSE on a channel, we assume it comes with an
7113 * implied EOF if we haven't seen EOF yet.
7115 ssh2_channel_got_eof(c);
7118 * And we also send an outgoing EOF, if we haven't already, on the
7119 * assumption that CLOSE is a pretty forceful announcement that
7120 * the remote side is doing away with the entire channel. (If it
7121 * had wanted to send us EOF and continue receiving data from us,
7122 * it would have just sent CHANNEL_EOF.)
7124 if (!(c->closes & CLOSES_SENT_EOF)) {
7126 * Make sure we don't read any more from whatever our local
7127 * data source is for this channel.
7130 case CHAN_MAINSESSION:
7131 ssh->send_ok = 0; /* stop trying to read from stdin */
7134 x11_override_throttle(c->u.x11.s, 1);
7137 pfd_override_throttle(c->u.pfd.s, 1);
7142 * Abandon any buffered data we still wanted to send to this
7143 * channel. Receiving a CHANNEL_CLOSE is an indication that
7144 * the server really wants to get on and _destroy_ this
7145 * channel, and it isn't going to send us any further
7146 * WINDOW_ADJUSTs to permit us to send pending stuff.
7148 bufchain_clear(&c->v.v2.outbuffer);
7151 * Send outgoing EOF.
7153 sshfwd_write_eof(c);
7157 * Now process the actual close.
7159 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7160 c->closes |= CLOSES_RCVD_CLOSE;
7161 ssh2_channel_check_close(c);
7165 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7167 struct ssh_channel *c;
7169 c = ssh2_channel_msg(ssh, pktin);
7172 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7173 c->remoteid = ssh_pkt_getuint32(pktin);
7174 c->halfopen = FALSE;
7175 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7176 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7178 if (c->type == CHAN_SOCKDATA_DORMANT) {
7179 c->type = CHAN_SOCKDATA;
7181 pfd_confirm(c->u.pfd.s);
7182 } else if (c->type == CHAN_ZOMBIE) {
7184 * This case can occur if a local socket error occurred
7185 * between us sending out CHANNEL_OPEN and receiving
7186 * OPEN_CONFIRMATION. In this case, all we can do is
7187 * immediately initiate close proceedings now that we know the
7188 * server's id to put in the close message.
7190 ssh2_channel_check_close(c);
7193 * We never expect to receive OPEN_CONFIRMATION for any
7194 * *other* channel type (since only local-to-remote port
7195 * forwardings cause us to send CHANNEL_OPEN after the main
7196 * channel is live - all other auxiliary channel types are
7197 * initiated from the server end). It's safe to enforce this
7198 * by assertion rather than by ssh_disconnect, because the
7199 * real point is that we never constructed a half-open channel
7200 * structure in the first place with any type other than the
7203 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7207 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7210 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7212 static const char *const reasons[] = {
7213 "<unknown reason code>",
7214 "Administratively prohibited",
7216 "Unknown channel type",
7217 "Resource shortage",
7219 unsigned reason_code;
7220 char *reason_string;
7222 struct ssh_channel *c;
7224 c = ssh2_channel_msg(ssh, pktin);
7227 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7229 if (c->type == CHAN_SOCKDATA_DORMANT) {
7230 reason_code = ssh_pkt_getuint32(pktin);
7231 if (reason_code >= lenof(reasons))
7232 reason_code = 0; /* ensure reasons[reason_code] in range */
7233 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7234 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7235 reasons[reason_code], reason_length, reason_string);
7237 pfd_close(c->u.pfd.s);
7238 } else if (c->type == CHAN_ZOMBIE) {
7240 * This case can occur if a local socket error occurred
7241 * between us sending out CHANNEL_OPEN and receiving
7242 * OPEN_FAILURE. In this case, we need do nothing except allow
7243 * the code below to throw the half-open channel away.
7247 * We never expect to receive OPEN_FAILURE for any *other*
7248 * channel type (since only local-to-remote port forwardings
7249 * cause us to send CHANNEL_OPEN after the main channel is
7250 * live - all other auxiliary channel types are initiated from
7251 * the server end). It's safe to enforce this by assertion
7252 * rather than by ssh_disconnect, because the real point is
7253 * that we never constructed a half-open channel structure in
7254 * the first place with any type other than the above.
7256 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7259 del234(ssh->channels, c);
7263 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7266 int typelen, want_reply;
7267 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7268 struct ssh_channel *c;
7269 struct Packet *pktout;
7271 c = ssh2_channel_msg(ssh, pktin);
7274 ssh_pkt_getstring(pktin, &type, &typelen);
7275 want_reply = ssh2_pkt_getbool(pktin);
7278 * Having got the channel number, we now look at
7279 * the request type string to see if it's something
7282 if (c == ssh->mainchan) {
7284 * We recognise "exit-status" and "exit-signal" on
7285 * the primary channel.
7287 if (typelen == 11 &&
7288 !memcmp(type, "exit-status", 11)) {
7290 ssh->exitcode = ssh_pkt_getuint32(pktin);
7291 logeventf(ssh, "Server sent command exit status %d",
7293 reply = SSH2_MSG_CHANNEL_SUCCESS;
7295 } else if (typelen == 11 &&
7296 !memcmp(type, "exit-signal", 11)) {
7298 int is_plausible = TRUE, is_int = FALSE;
7299 char *fmt_sig = "", *fmt_msg = "";
7301 int msglen = 0, core = FALSE;
7302 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7303 * provide an `int' for the signal, despite its
7304 * having been a `string' in the drafts of RFC 4254 since at
7305 * least 2001. (Fixed in session.c 1.147.) Try to
7306 * infer which we can safely parse it as. */
7308 unsigned char *p = pktin->body +
7310 long len = pktin->length - pktin->savedpos;
7311 unsigned long num = GET_32BIT(p); /* what is it? */
7312 /* If it's 0, it hardly matters; assume string */
7316 int maybe_int = FALSE, maybe_str = FALSE;
7317 #define CHECK_HYPOTHESIS(offset, result) \
7320 int q = toint(offset); \
7321 if (q >= 0 && q+4 <= len) { \
7322 q = toint(q + 4 + GET_32BIT(p+q)); \
7323 if (q >= 0 && q+4 <= len && \
7324 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7329 CHECK_HYPOTHESIS(4+1, maybe_int);
7330 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7331 #undef CHECK_HYPOTHESIS
7332 if (maybe_int && !maybe_str)
7334 else if (!maybe_int && maybe_str)
7337 /* Crikey. Either or neither. Panic. */
7338 is_plausible = FALSE;
7341 ssh->exitcode = 128; /* means `unknown signal' */
7344 /* Old non-standard OpenSSH. */
7345 int signum = ssh_pkt_getuint32(pktin);
7346 fmt_sig = dupprintf(" %d", signum);
7347 ssh->exitcode = 128 + signum;
7349 /* As per RFC 4254. */
7352 ssh_pkt_getstring(pktin, &sig, &siglen);
7353 /* Signal name isn't supposed to be blank, but
7354 * let's cope gracefully if it is. */
7356 fmt_sig = dupprintf(" \"%.*s\"",
7361 * Really hideous method of translating the
7362 * signal description back into a locally
7363 * meaningful number.
7368 #define TRANSLATE_SIGNAL(s) \
7369 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7370 ssh->exitcode = 128 + SIG ## s
7372 TRANSLATE_SIGNAL(ABRT);
7375 TRANSLATE_SIGNAL(ALRM);
7378 TRANSLATE_SIGNAL(FPE);
7381 TRANSLATE_SIGNAL(HUP);
7384 TRANSLATE_SIGNAL(ILL);
7387 TRANSLATE_SIGNAL(INT);
7390 TRANSLATE_SIGNAL(KILL);
7393 TRANSLATE_SIGNAL(PIPE);
7396 TRANSLATE_SIGNAL(QUIT);
7399 TRANSLATE_SIGNAL(SEGV);
7402 TRANSLATE_SIGNAL(TERM);
7405 TRANSLATE_SIGNAL(USR1);
7408 TRANSLATE_SIGNAL(USR2);
7410 #undef TRANSLATE_SIGNAL
7412 ssh->exitcode = 128;
7414 core = ssh2_pkt_getbool(pktin);
7415 ssh_pkt_getstring(pktin, &msg, &msglen);
7417 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7419 /* ignore lang tag */
7420 } /* else don't attempt to parse */
7421 logeventf(ssh, "Server exited on signal%s%s%s",
7422 fmt_sig, core ? " (core dumped)" : "",
7424 if (*fmt_sig) sfree(fmt_sig);
7425 if (*fmt_msg) sfree(fmt_msg);
7426 reply = SSH2_MSG_CHANNEL_SUCCESS;
7431 * This is a channel request we don't know
7432 * about, so we now either ignore the request
7433 * or respond with CHANNEL_FAILURE, depending
7436 reply = SSH2_MSG_CHANNEL_FAILURE;
7439 pktout = ssh2_pkt_init(reply);
7440 ssh2_pkt_adduint32(pktout, c->remoteid);
7441 ssh2_pkt_send(ssh, pktout);
7445 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7448 int typelen, want_reply;
7449 struct Packet *pktout;
7451 ssh_pkt_getstring(pktin, &type, &typelen);
7452 want_reply = ssh2_pkt_getbool(pktin);
7455 * We currently don't support any global requests
7456 * at all, so we either ignore the request or
7457 * respond with REQUEST_FAILURE, depending on
7461 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7462 ssh2_pkt_send(ssh, pktout);
7466 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7474 struct ssh_channel *c;
7475 unsigned remid, winsize, pktsize;
7476 struct Packet *pktout;
7478 ssh_pkt_getstring(pktin, &type, &typelen);
7479 c = snew(struct ssh_channel);
7482 remid = ssh_pkt_getuint32(pktin);
7483 winsize = ssh_pkt_getuint32(pktin);
7484 pktsize = ssh_pkt_getuint32(pktin);
7486 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7490 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7491 addrstr = snewn(peeraddrlen+1, char);
7492 memcpy(addrstr, peeraddr, peeraddrlen);
7493 addrstr[peeraddrlen] = '\0';
7494 peerport = ssh_pkt_getuint32(pktin);
7496 logeventf(ssh, "Received X11 connect request from %s:%d",
7499 if (!ssh->X11_fwd_enabled)
7500 error = "X11 forwarding is not enabled";
7501 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
7502 addrstr, peerport, ssh->conf)) != NULL) {
7503 logeventf(ssh, "Local X11 connection failed: %s", x11err);
7504 error = "Unable to open an X11 connection";
7506 logevent("Opening X11 forward connection succeeded");
7511 } else if (typelen == 15 &&
7512 !memcmp(type, "forwarded-tcpip", 15)) {
7513 struct ssh_rportfwd pf, *realpf;
7516 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7517 pf.sport = ssh_pkt_getuint32(pktin);
7518 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7519 peerport = ssh_pkt_getuint32(pktin);
7520 realpf = find234(ssh->rportfwds, &pf, NULL);
7521 logeventf(ssh, "Received remote port %d open request "
7522 "from %s:%d", pf.sport, peeraddr, peerport);
7523 if (realpf == NULL) {
7524 error = "Remote port is not recognised";
7526 const char *e = pfd_newconnect(&c->u.pfd.s,
7530 realpf->pfrec->addressfamily);
7531 logeventf(ssh, "Attempting to forward remote port to "
7532 "%s:%d", realpf->dhost, realpf->dport);
7534 logeventf(ssh, "Port open failed: %s", e);
7535 error = "Port open failed";
7537 logevent("Forwarded port opened successfully");
7538 c->type = CHAN_SOCKDATA;
7541 } else if (typelen == 22 &&
7542 !memcmp(type, "auth-agent@openssh.com", 22)) {
7543 if (!ssh->agentfwd_enabled)
7544 error = "Agent forwarding is not enabled";
7546 c->type = CHAN_AGENT; /* identify channel type */
7547 c->u.a.lensofar = 0;
7548 c->u.a.message = NULL;
7549 c->u.a.outstanding_requests = 0;
7552 error = "Unsupported channel type requested";
7555 c->remoteid = remid;
7556 c->halfopen = FALSE;
7558 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7559 ssh2_pkt_adduint32(pktout, c->remoteid);
7560 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7561 ssh2_pkt_addstring(pktout, error);
7562 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7563 ssh2_pkt_send(ssh, pktout);
7564 logeventf(ssh, "Rejected channel open: %s", error);
7567 ssh2_channel_init(c);
7568 c->v.v2.remwindow = winsize;
7569 c->v.v2.remmaxpkt = pktsize;
7570 add234(ssh->channels, c);
7571 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7572 ssh2_pkt_adduint32(pktout, c->remoteid);
7573 ssh2_pkt_adduint32(pktout, c->localid);
7574 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
7575 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7576 ssh2_pkt_send(ssh, pktout);
7581 * Buffer banner messages for later display at some convenient point,
7582 * if we're going to display them.
7584 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7586 /* Arbitrary limit to prevent unbounded inflation of buffer */
7587 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
7588 bufchain_size(&ssh->banner) <= 131072) {
7589 char *banner = NULL;
7591 ssh_pkt_getstring(pktin, &banner, &size);
7593 bufchain_add(&ssh->banner, banner, size);
7597 /* Helper function to deal with sending tty modes for "pty-req" */
7598 static void ssh2_send_ttymode(void *data, char *mode, char *val)
7600 struct Packet *pktout = (struct Packet *)data;
7602 unsigned int arg = 0;
7603 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7604 if (i == lenof(ssh_ttymodes)) return;
7605 switch (ssh_ttymodes[i].type) {
7607 arg = ssh_tty_parse_specchar(val);
7610 arg = ssh_tty_parse_boolean(val);
7613 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7614 ssh2_pkt_adduint32(pktout, arg);
7617 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
7620 struct ssh2_setup_x11_state {
7624 struct Packet *pktout;
7625 crStateP(ssh2_setup_x11_state, ctx);
7629 logevent("Requesting X11 forwarding");
7630 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
7632 ssh2_pkt_addbool(pktout, 0); /* many connections */
7633 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname);
7635 * Note that while we blank the X authentication data here, we don't
7636 * take any special action to blank the start of an X11 channel,
7637 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7638 * without having session blanking enabled is likely to leak your
7639 * cookie into the log.
7641 dont_log_password(ssh, pktout, PKTLOG_BLANK);
7642 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring);
7643 end_log_omission(ssh, pktout);
7644 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
7645 ssh2_pkt_send(ssh, pktout);
7647 /* Wait to be called back with either a response packet, or NULL
7648 * meaning clean up and free our data */
7652 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7653 logevent("X11 forwarding enabled");
7654 ssh->X11_fwd_enabled = TRUE;
7656 logevent("X11 forwarding refused");
7662 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
7665 struct ssh2_setup_agent_state {
7669 struct Packet *pktout;
7670 crStateP(ssh2_setup_agent_state, ctx);
7674 logevent("Requesting OpenSSH-style agent forwarding");
7675 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
7676 ssh2_setup_agent, s);
7677 ssh2_pkt_send(ssh, pktout);
7679 /* Wait to be called back with either a response packet, or NULL
7680 * meaning clean up and free our data */
7684 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7685 logevent("Agent forwarding enabled");
7686 ssh->agentfwd_enabled = TRUE;
7688 logevent("Agent forwarding refused");
7694 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
7697 struct ssh2_setup_pty_state {
7701 struct Packet *pktout;
7702 crStateP(ssh2_setup_pty_state, ctx);
7706 /* Unpick the terminal-speed string. */
7707 /* XXX perhaps we should allow no speeds to be sent. */
7708 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7709 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
7710 /* Build the pty request. */
7711 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
7713 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
7714 ssh2_pkt_adduint32(pktout, ssh->term_width);
7715 ssh2_pkt_adduint32(pktout, ssh->term_height);
7716 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
7717 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
7718 ssh2_pkt_addstring_start(pktout);
7719 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
7720 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
7721 ssh2_pkt_adduint32(pktout, ssh->ispeed);
7722 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
7723 ssh2_pkt_adduint32(pktout, ssh->ospeed);
7724 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
7725 ssh2_pkt_send(ssh, pktout);
7726 ssh->state = SSH_STATE_INTERMED;
7728 /* Wait to be called back with either a response packet, or NULL
7729 * meaning clean up and free our data */
7733 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7734 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7735 ssh->ospeed, ssh->ispeed);
7736 ssh->got_pty = TRUE;
7738 c_write_str(ssh, "Server refused to allocate pty\r\n");
7739 ssh->editing = ssh->echoing = 1;
7746 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
7749 struct ssh2_setup_env_state {
7751 int num_env, env_left, env_ok;
7754 struct Packet *pktout;
7755 crStateP(ssh2_setup_env_state, ctx);
7760 * Send environment variables.
7762 * Simplest thing here is to send all the requests at once, and
7763 * then wait for a whole bunch of successes or failures.
7769 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
7771 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
7772 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
7773 ssh2_pkt_addstring(pktout, key);
7774 ssh2_pkt_addstring(pktout, val);
7775 ssh2_pkt_send(ssh, pktout);
7780 logeventf(ssh, "Sent %d environment variables", s->num_env);
7785 s->env_left = s->num_env;
7787 while (s->env_left > 0) {
7788 /* Wait to be called back with either a response packet,
7789 * or NULL meaning clean up and free our data */
7791 if (!pktin) goto out;
7792 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
7797 if (s->env_ok == s->num_env) {
7798 logevent("All environment variables successfully set");
7799 } else if (s->env_ok == 0) {
7800 logevent("All environment variables refused");
7801 c_write_str(ssh, "Server refused to set environment variables\r\n");
7803 logeventf(ssh, "%d environment variables refused",
7804 s->num_env - s->env_ok);
7805 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7813 * Handle the SSH-2 userauth and connection layers.
7815 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
7817 do_ssh2_authconn(ssh, NULL, 0, pktin);
7820 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
7823 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
7826 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7827 struct Packet *pktin)
7829 struct do_ssh2_authconn_state {
7833 AUTH_TYPE_PUBLICKEY,
7834 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7835 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7837 AUTH_TYPE_GSSAPI, /* always QUIET */
7838 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7839 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7841 int done_service_req;
7842 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
7843 int tried_pubkey_config, done_agent;
7848 int kbd_inter_refused;
7849 int we_are_in, userauth_success;
7850 prompts_t *cur_prompt;
7855 void *publickey_blob;
7856 int publickey_bloblen;
7857 int publickey_encrypted;
7858 char *publickey_algorithm;
7859 char *publickey_comment;
7860 unsigned char agent_request[5], *agent_response, *agentp;
7861 int agent_responselen;
7862 unsigned char *pkblob_in_agent;
7864 char *pkblob, *alg, *commentp;
7865 int pklen, alglen, commentlen;
7866 int siglen, retlen, len;
7867 char *q, *agentreq, *ret;
7869 struct Packet *pktout;
7872 struct ssh_gss_library *gsslib;
7873 Ssh_gss_ctx gss_ctx;
7874 Ssh_gss_buf gss_buf;
7875 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7876 Ssh_gss_name gss_srv_name;
7877 Ssh_gss_stat gss_stat;
7880 crState(do_ssh2_authconn_state);
7884 /* Register as a handler for all the messages this coroutine handles. */
7885 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
7886 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
7887 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
7888 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
7889 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
7890 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
7891 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7892 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7893 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
7894 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
7895 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
7896 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
7897 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
7898 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
7899 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
7900 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
7901 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
7902 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
7903 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
7904 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
7906 s->done_service_req = FALSE;
7907 s->we_are_in = s->userauth_success = FALSE;
7909 s->tried_gssapi = FALSE;
7912 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
7914 * Request userauth protocol, and await a response to it.
7916 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7917 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7918 ssh2_pkt_send(ssh, s->pktout);
7919 crWaitUntilV(pktin);
7920 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7921 s->done_service_req = TRUE;
7923 if (!s->done_service_req) {
7925 * Request connection protocol directly, without authentication.
7927 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7928 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7929 ssh2_pkt_send(ssh, s->pktout);
7930 crWaitUntilV(pktin);
7931 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7932 s->we_are_in = TRUE; /* no auth required */
7934 bombout(("Server refused service request"));
7939 /* Arrange to be able to deal with any BANNERs that come in.
7940 * (We do this now as packets may come in during the next bit.) */
7941 bufchain_init(&ssh->banner);
7942 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7943 ssh2_msg_userauth_banner;
7946 * Misc one-time setup for authentication.
7948 s->publickey_blob = NULL;
7949 if (!s->we_are_in) {
7952 * Load the public half of any configured public key file
7955 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
7956 if (!filename_is_null(s->keyfile)) {
7958 logeventf(ssh, "Reading private key file \"%.150s\"",
7959 filename_to_str(s->keyfile));
7960 keytype = key_type(s->keyfile);
7961 if (keytype == SSH_KEYTYPE_SSH2) {
7964 ssh2_userkey_loadpub(s->keyfile,
7965 &s->publickey_algorithm,
7966 &s->publickey_bloblen,
7967 &s->publickey_comment, &error);
7968 if (s->publickey_blob) {
7969 s->publickey_encrypted =
7970 ssh2_userkey_encrypted(s->keyfile, NULL);
7973 logeventf(ssh, "Unable to load private key (%s)",
7975 msgbuf = dupprintf("Unable to load private key file "
7976 "\"%.150s\" (%s)\r\n",
7977 filename_to_str(s->keyfile),
7979 c_write_str(ssh, msgbuf);
7984 logeventf(ssh, "Unable to use this key file (%s)",
7985 key_type_to_str(keytype));
7986 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7988 filename_to_str(s->keyfile),
7989 key_type_to_str(keytype));
7990 c_write_str(ssh, msgbuf);
7992 s->publickey_blob = NULL;
7997 * Find out about any keys Pageant has (but if there's a
7998 * public key configured, filter out all others).
8001 s->agent_response = NULL;
8002 s->pkblob_in_agent = NULL;
8003 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8007 logevent("Pageant is running. Requesting keys.");
8009 /* Request the keys held by the agent. */
8010 PUT_32BIT(s->agent_request, 1);
8011 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8012 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8013 ssh_agent_callback, ssh)) {
8017 bombout(("Unexpected data from server while"
8018 " waiting for agent response"));
8021 } while (pktin || inlen > 0);
8022 r = ssh->agent_response;
8023 s->agent_responselen = ssh->agent_response_len;
8025 s->agent_response = (unsigned char *) r;
8026 if (s->agent_response && s->agent_responselen >= 5 &&
8027 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8030 p = s->agent_response + 5;
8031 s->nkeys = toint(GET_32BIT(p));
8034 * Vet the Pageant response to ensure that the key
8035 * count and blob lengths make sense.
8038 logeventf(ssh, "Pageant response contained a negative"
8039 " key count %d", s->nkeys);
8041 goto done_agent_query;
8043 unsigned char *q = p + 4;
8044 int lenleft = s->agent_responselen - 5 - 4;
8046 for (keyi = 0; keyi < s->nkeys; keyi++) {
8047 int bloblen, commentlen;
8049 logeventf(ssh, "Pageant response was truncated");
8051 goto done_agent_query;
8053 bloblen = toint(GET_32BIT(q));
8054 if (bloblen < 0 || bloblen > lenleft) {
8055 logeventf(ssh, "Pageant response was truncated");
8057 goto done_agent_query;
8059 lenleft -= 4 + bloblen;
8061 commentlen = toint(GET_32BIT(q));
8062 if (commentlen < 0 || commentlen > lenleft) {
8063 logeventf(ssh, "Pageant response was truncated");
8065 goto done_agent_query;
8067 lenleft -= 4 + commentlen;
8068 q += 4 + commentlen;
8073 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8074 if (s->publickey_blob) {
8075 /* See if configured key is in agent. */
8076 for (keyi = 0; keyi < s->nkeys; keyi++) {
8077 s->pklen = toint(GET_32BIT(p));
8078 if (s->pklen == s->publickey_bloblen &&
8079 !memcmp(p+4, s->publickey_blob,
8080 s->publickey_bloblen)) {
8081 logeventf(ssh, "Pageant key #%d matches "
8082 "configured key file", keyi);
8084 s->pkblob_in_agent = p;
8088 p += toint(GET_32BIT(p)) + 4; /* comment */
8090 if (!s->pkblob_in_agent) {
8091 logevent("Configured key file not in Pageant");
8096 logevent("Failed to get reply from Pageant");
8104 * We repeat this whole loop, including the username prompt,
8105 * until we manage a successful authentication. If the user
8106 * types the wrong _password_, they can be sent back to the
8107 * beginning to try another username, if this is configured on.
8108 * (If they specify a username in the config, they are never
8109 * asked, even if they do give a wrong password.)
8111 * I think this best serves the needs of
8113 * - the people who have no configuration, no keys, and just
8114 * want to try repeated (username,password) pairs until they
8115 * type both correctly
8117 * - people who have keys and configuration but occasionally
8118 * need to fall back to passwords
8120 * - people with a key held in Pageant, who might not have
8121 * logged in to a particular machine before; so they want to
8122 * type a username, and then _either_ their key will be
8123 * accepted, _or_ they will type a password. If they mistype
8124 * the username they will want to be able to get back and
8127 s->got_username = FALSE;
8128 while (!s->we_are_in) {
8132 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8134 * We got a username last time round this loop, and
8135 * with change_username turned off we don't try to get
8138 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8139 int ret; /* need not be kept over crReturn */
8140 s->cur_prompt = new_prompts(ssh->frontend);
8141 s->cur_prompt->to_server = TRUE;
8142 s->cur_prompt->name = dupstr("SSH login name");
8143 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8144 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8147 crWaitUntilV(!pktin);
8148 ret = get_userpass_input(s->cur_prompt, in, inlen);
8153 * get_userpass_input() failed to get a username.
8156 free_prompts(s->cur_prompt);
8157 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8160 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8161 free_prompts(s->cur_prompt);
8164 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8165 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8166 c_write_str(ssh, stuff);
8170 s->got_username = TRUE;
8173 * Send an authentication request using method "none": (a)
8174 * just in case it succeeds, and (b) so that we know what
8175 * authentication methods we can usefully try next.
8177 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8179 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8180 ssh2_pkt_addstring(s->pktout, ssh->username);
8181 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8182 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8183 ssh2_pkt_send(ssh, s->pktout);
8184 s->type = AUTH_TYPE_NONE;
8186 s->we_are_in = FALSE;
8188 s->tried_pubkey_config = FALSE;
8189 s->kbd_inter_refused = FALSE;
8191 /* Reset agent request state. */
8192 s->done_agent = FALSE;
8193 if (s->agent_response) {
8194 if (s->pkblob_in_agent) {
8195 s->agentp = s->pkblob_in_agent;
8197 s->agentp = s->agent_response + 5 + 4;
8203 char *methods = NULL;
8207 * Wait for the result of the last authentication request.
8210 crWaitUntilV(pktin);
8212 * Now is a convenient point to spew any banner material
8213 * that we've accumulated. (This should ensure that when
8214 * we exit the auth loop, we haven't any left to deal
8218 int size = bufchain_size(&ssh->banner);
8220 * Don't show the banner if we're operating in
8221 * non-verbose non-interactive mode. (It's probably
8222 * a script, which means nobody will read the
8223 * banner _anyway_, and moreover the printing of
8224 * the banner will screw up processing on the
8225 * output of (say) plink.)
8227 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8228 char *banner = snewn(size, char);
8229 bufchain_fetch(&ssh->banner, banner, size);
8230 c_write_untrusted(ssh, banner, size);
8233 bufchain_clear(&ssh->banner);
8235 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8236 logevent("Access granted");
8237 s->we_are_in = s->userauth_success = TRUE;
8241 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8242 bombout(("Strange packet received during authentication: "
8243 "type %d", pktin->type));
8250 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8251 * we can look at the string in it and know what we can
8252 * helpfully try next.
8254 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8255 ssh_pkt_getstring(pktin, &methods, &methlen);
8256 if (!ssh2_pkt_getbool(pktin)) {
8258 * We have received an unequivocal Access
8259 * Denied. This can translate to a variety of
8260 * messages, or no message at all.
8262 * For forms of authentication which are attempted
8263 * implicitly, by which I mean without printing
8264 * anything in the window indicating that we're
8265 * trying them, we should never print 'Access
8268 * If we do print a message saying that we're
8269 * attempting some kind of authentication, it's OK
8270 * to print a followup message saying it failed -
8271 * but the message may sometimes be more specific
8272 * than simply 'Access denied'.
8274 * Additionally, if we'd just tried password
8275 * authentication, we should break out of this
8276 * whole loop so as to go back to the username
8277 * prompt (iff we're configured to allow
8278 * username change attempts).
8280 if (s->type == AUTH_TYPE_NONE) {
8282 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8283 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8284 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8285 c_write_str(ssh, "Server refused our key\r\n");
8286 logevent("Server refused our key");
8287 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8288 /* This _shouldn't_ happen except by a
8289 * protocol bug causing client and server to
8290 * disagree on what is a correct signature. */
8291 c_write_str(ssh, "Server refused public-key signature"
8292 " despite accepting key!\r\n");
8293 logevent("Server refused public-key signature"
8294 " despite accepting key!");
8295 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8296 /* quiet, so no c_write */
8297 logevent("Server refused keyboard-interactive authentication");
8298 } else if (s->type==AUTH_TYPE_GSSAPI) {
8299 /* always quiet, so no c_write */
8300 /* also, the code down in the GSSAPI block has
8301 * already logged this in the Event Log */
8302 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8303 logevent("Keyboard-interactive authentication failed");
8304 c_write_str(ssh, "Access denied\r\n");
8306 assert(s->type == AUTH_TYPE_PASSWORD);
8307 logevent("Password authentication failed");
8308 c_write_str(ssh, "Access denied\r\n");
8310 if (conf_get_int(ssh->conf, CONF_change_username)) {
8311 /* XXX perhaps we should allow
8312 * keyboard-interactive to do this too? */
8313 s->we_are_in = FALSE;
8318 c_write_str(ssh, "Further authentication required\r\n");
8319 logevent("Further authentication required");
8323 in_commasep_string("publickey", methods, methlen);
8325 in_commasep_string("password", methods, methlen);
8326 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8327 in_commasep_string("keyboard-interactive", methods, methlen);
8330 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8331 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8332 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8333 ssh->gsslibs->nlibraries > 0;
8337 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8339 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8342 * Attempt public-key authentication using a key from Pageant.
8345 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8347 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8349 /* Unpack key from agent response */
8350 s->pklen = toint(GET_32BIT(s->agentp));
8352 s->pkblob = (char *)s->agentp;
8353 s->agentp += s->pklen;
8354 s->alglen = toint(GET_32BIT(s->pkblob));
8355 s->alg = s->pkblob + 4;
8356 s->commentlen = toint(GET_32BIT(s->agentp));
8358 s->commentp = (char *)s->agentp;
8359 s->agentp += s->commentlen;
8360 /* s->agentp now points at next key, if any */
8362 /* See if server will accept it */
8363 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8364 ssh2_pkt_addstring(s->pktout, ssh->username);
8365 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8366 /* service requested */
8367 ssh2_pkt_addstring(s->pktout, "publickey");
8369 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8370 ssh2_pkt_addstring_start(s->pktout);
8371 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8372 ssh2_pkt_addstring_start(s->pktout);
8373 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8374 ssh2_pkt_send(ssh, s->pktout);
8375 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8377 crWaitUntilV(pktin);
8378 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8380 /* Offer of key refused. */
8387 if (flags & FLAG_VERBOSE) {
8388 c_write_str(ssh, "Authenticating with "
8390 c_write(ssh, s->commentp, s->commentlen);
8391 c_write_str(ssh, "\" from agent\r\n");
8395 * Server is willing to accept the key.
8396 * Construct a SIGN_REQUEST.
8398 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8399 ssh2_pkt_addstring(s->pktout, ssh->username);
8400 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8401 /* service requested */
8402 ssh2_pkt_addstring(s->pktout, "publickey");
8404 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8405 ssh2_pkt_addstring_start(s->pktout);
8406 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8407 ssh2_pkt_addstring_start(s->pktout);
8408 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8410 /* Ask agent for signature. */
8411 s->siglen = s->pktout->length - 5 + 4 +
8412 ssh->v2_session_id_len;
8413 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8415 s->len = 1; /* message type */
8416 s->len += 4 + s->pklen; /* key blob */
8417 s->len += 4 + s->siglen; /* data to sign */
8418 s->len += 4; /* flags */
8419 s->agentreq = snewn(4 + s->len, char);
8420 PUT_32BIT(s->agentreq, s->len);
8421 s->q = s->agentreq + 4;
8422 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8423 PUT_32BIT(s->q, s->pklen);
8425 memcpy(s->q, s->pkblob, s->pklen);
8427 PUT_32BIT(s->q, s->siglen);
8429 /* Now the data to be signed... */
8430 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8431 PUT_32BIT(s->q, ssh->v2_session_id_len);
8434 memcpy(s->q, ssh->v2_session_id,
8435 ssh->v2_session_id_len);
8436 s->q += ssh->v2_session_id_len;
8437 memcpy(s->q, s->pktout->data + 5,
8438 s->pktout->length - 5);
8439 s->q += s->pktout->length - 5;
8440 /* And finally the (zero) flags word. */
8442 if (!agent_query(s->agentreq, s->len + 4,
8444 ssh_agent_callback, ssh)) {
8448 bombout(("Unexpected data from server"
8449 " while waiting for agent"
8453 } while (pktin || inlen > 0);
8454 vret = ssh->agent_response;
8455 s->retlen = ssh->agent_response_len;
8460 if (s->retlen >= 9 &&
8461 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
8462 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
8463 logevent("Sending Pageant's response");
8464 ssh2_add_sigblob(ssh, s->pktout,
8465 s->pkblob, s->pklen,
8467 GET_32BIT(s->ret + 5));
8468 ssh2_pkt_send(ssh, s->pktout);
8469 s->type = AUTH_TYPE_PUBLICKEY;
8471 /* FIXME: less drastic response */
8472 bombout(("Pageant failed to answer challenge"));
8478 /* Do we have any keys left to try? */
8479 if (s->pkblob_in_agent) {
8480 s->done_agent = TRUE;
8481 s->tried_pubkey_config = TRUE;
8484 if (s->keyi >= s->nkeys)
8485 s->done_agent = TRUE;
8488 } else if (s->can_pubkey && s->publickey_blob &&
8489 !s->tried_pubkey_config) {
8491 struct ssh2_userkey *key; /* not live over crReturn */
8492 char *passphrase; /* not live over crReturn */
8494 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8496 s->tried_pubkey_config = TRUE;
8499 * Try the public key supplied in the configuration.
8501 * First, offer the public blob to see if the server is
8502 * willing to accept it.
8504 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8505 ssh2_pkt_addstring(s->pktout, ssh->username);
8506 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8507 /* service requested */
8508 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8509 ssh2_pkt_addbool(s->pktout, FALSE);
8510 /* no signature included */
8511 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8512 ssh2_pkt_addstring_start(s->pktout);
8513 ssh2_pkt_addstring_data(s->pktout,
8514 (char *)s->publickey_blob,
8515 s->publickey_bloblen);
8516 ssh2_pkt_send(ssh, s->pktout);
8517 logevent("Offered public key");
8519 crWaitUntilV(pktin);
8520 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8521 /* Key refused. Give up. */
8522 s->gotit = TRUE; /* reconsider message next loop */
8523 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8524 continue; /* process this new message */
8526 logevent("Offer of public key accepted");
8529 * Actually attempt a serious authentication using
8532 if (flags & FLAG_VERBOSE) {
8533 c_write_str(ssh, "Authenticating with public key \"");
8534 c_write_str(ssh, s->publickey_comment);
8535 c_write_str(ssh, "\"\r\n");
8539 const char *error; /* not live over crReturn */
8540 if (s->publickey_encrypted) {
8542 * Get a passphrase from the user.
8544 int ret; /* need not be kept over crReturn */
8545 s->cur_prompt = new_prompts(ssh->frontend);
8546 s->cur_prompt->to_server = FALSE;
8547 s->cur_prompt->name = dupstr("SSH key passphrase");
8548 add_prompt(s->cur_prompt,
8549 dupprintf("Passphrase for key \"%.100s\": ",
8550 s->publickey_comment),
8552 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8555 crWaitUntilV(!pktin);
8556 ret = get_userpass_input(s->cur_prompt,
8561 /* Failed to get a passphrase. Terminate. */
8562 free_prompts(s->cur_prompt);
8563 ssh_disconnect(ssh, NULL,
8564 "Unable to authenticate",
8565 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8570 dupstr(s->cur_prompt->prompts[0]->result);
8571 free_prompts(s->cur_prompt);
8573 passphrase = NULL; /* no passphrase needed */
8577 * Try decrypting the key.
8579 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8580 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
8582 /* burn the evidence */
8583 smemclr(passphrase, strlen(passphrase));
8586 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8588 (key == SSH2_WRONG_PASSPHRASE)) {
8589 c_write_str(ssh, "Wrong passphrase\r\n");
8591 /* and loop again */
8593 c_write_str(ssh, "Unable to load private key (");
8594 c_write_str(ssh, error);
8595 c_write_str(ssh, ")\r\n");
8597 break; /* try something else */
8603 unsigned char *pkblob, *sigblob, *sigdata;
8604 int pkblob_len, sigblob_len, sigdata_len;
8608 * We have loaded the private key and the server
8609 * has announced that it's willing to accept it.
8610 * Hallelujah. Generate a signature and send it.
8612 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8613 ssh2_pkt_addstring(s->pktout, ssh->username);
8614 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8615 /* service requested */
8616 ssh2_pkt_addstring(s->pktout, "publickey");
8618 ssh2_pkt_addbool(s->pktout, TRUE);
8619 /* signature follows */
8620 ssh2_pkt_addstring(s->pktout, key->alg->name);
8621 pkblob = key->alg->public_blob(key->data,
8623 ssh2_pkt_addstring_start(s->pktout);
8624 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8628 * The data to be signed is:
8632 * followed by everything so far placed in the
8635 sigdata_len = s->pktout->length - 5 + 4 +
8636 ssh->v2_session_id_len;
8637 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8639 sigdata = snewn(sigdata_len, unsigned char);
8641 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8642 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8645 memcpy(sigdata+p, ssh->v2_session_id,
8646 ssh->v2_session_id_len);
8647 p += ssh->v2_session_id_len;
8648 memcpy(sigdata+p, s->pktout->data + 5,
8649 s->pktout->length - 5);
8650 p += s->pktout->length - 5;
8651 assert(p == sigdata_len);
8652 sigblob = key->alg->sign(key->data, (char *)sigdata,
8653 sigdata_len, &sigblob_len);
8654 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
8655 sigblob, sigblob_len);
8660 ssh2_pkt_send(ssh, s->pktout);
8661 logevent("Sent public key signature");
8662 s->type = AUTH_TYPE_PUBLICKEY;
8663 key->alg->freekey(key->data);
8667 } else if (s->can_gssapi && !s->tried_gssapi) {
8669 /* GSSAPI Authentication */
8674 s->type = AUTH_TYPE_GSSAPI;
8675 s->tried_gssapi = TRUE;
8677 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8680 * Pick the highest GSS library on the preference
8686 for (i = 0; i < ngsslibs; i++) {
8687 int want_id = conf_get_int_int(ssh->conf,
8688 CONF_ssh_gsslist, i);
8689 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8690 if (ssh->gsslibs->libraries[j].id == want_id) {
8691 s->gsslib = &ssh->gsslibs->libraries[j];
8692 goto got_gsslib; /* double break */
8697 * We always expect to have found something in
8698 * the above loop: we only came here if there
8699 * was at least one viable GSS library, and the
8700 * preference list should always mention
8701 * everything and only change the order.
8706 if (s->gsslib->gsslogmsg)
8707 logevent(s->gsslib->gsslogmsg);
8709 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8710 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8711 ssh2_pkt_addstring(s->pktout, ssh->username);
8712 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8713 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8714 logevent("Attempting GSSAPI authentication");
8716 /* add mechanism info */
8717 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
8719 /* number of GSSAPI mechanisms */
8720 ssh2_pkt_adduint32(s->pktout,1);
8722 /* length of OID + 2 */
8723 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
8724 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8727 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
8729 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8731 ssh2_pkt_send(ssh, s->pktout);
8732 crWaitUntilV(pktin);
8733 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8734 logevent("GSSAPI authentication request refused");
8738 /* check returned packet ... */
8740 ssh_pkt_getstring(pktin, &data, &len);
8741 s->gss_rcvtok.value = data;
8742 s->gss_rcvtok.length = len;
8743 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8744 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8745 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8746 memcmp((char *)s->gss_rcvtok.value + 2,
8747 s->gss_buf.value,s->gss_buf.length) ) {
8748 logevent("GSSAPI authentication - wrong response from server");
8752 /* now start running */
8753 s->gss_stat = s->gsslib->import_name(s->gsslib,
8756 if (s->gss_stat != SSH_GSS_OK) {
8757 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8758 logevent("GSSAPI import name failed - Bad service name");
8760 logevent("GSSAPI import name failed");
8764 /* fetch TGT into GSS engine */
8765 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
8767 if (s->gss_stat != SSH_GSS_OK) {
8768 logevent("GSSAPI authentication failed to get credentials");
8769 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8773 /* initial tokens are empty */
8774 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
8775 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
8777 /* now enter the loop */
8779 s->gss_stat = s->gsslib->init_sec_context
8783 conf_get_int(ssh->conf, CONF_gssapifwd),
8787 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8788 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8789 logevent("GSSAPI authentication initialisation failed");
8791 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8792 &s->gss_buf) == SSH_GSS_OK) {
8793 logevent(s->gss_buf.value);
8794 sfree(s->gss_buf.value);
8799 logevent("GSSAPI authentication initialised");
8801 /* Client and server now exchange tokens until GSSAPI
8802 * no longer says CONTINUE_NEEDED */
8804 if (s->gss_sndtok.length != 0) {
8805 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8806 ssh_pkt_addstring_start(s->pktout);
8807 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
8808 ssh2_pkt_send(ssh, s->pktout);
8809 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
8812 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8813 crWaitUntilV(pktin);
8814 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8815 logevent("GSSAPI authentication - bad server response");
8816 s->gss_stat = SSH_GSS_FAILURE;
8819 ssh_pkt_getstring(pktin, &data, &len);
8820 s->gss_rcvtok.value = data;
8821 s->gss_rcvtok.length = len;
8823 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8825 if (s->gss_stat != SSH_GSS_OK) {
8826 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8827 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8830 logevent("GSSAPI authentication loop finished OK");
8832 /* Now send the MIC */
8834 s->pktout = ssh2_pkt_init(0);
8835 micoffset = s->pktout->length;
8836 ssh_pkt_addstring_start(s->pktout);
8837 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8838 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
8839 ssh_pkt_addstring(s->pktout, ssh->username);
8840 ssh_pkt_addstring(s->pktout, "ssh-connection");
8841 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8843 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8844 s->gss_buf.length = s->pktout->length - micoffset;
8846 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
8847 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8848 ssh_pkt_addstring_start(s->pktout);
8849 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
8850 ssh2_pkt_send(ssh, s->pktout);
8851 s->gsslib->free_mic(s->gsslib, &mic);
8855 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8856 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8859 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8862 * Keyboard-interactive authentication.
8865 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8867 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
8869 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8870 ssh2_pkt_addstring(s->pktout, ssh->username);
8871 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8872 /* service requested */
8873 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8875 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8876 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8877 ssh2_pkt_send(ssh, s->pktout);
8879 logevent("Attempting keyboard-interactive authentication");
8881 crWaitUntilV(pktin);
8882 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8883 /* Server is not willing to do keyboard-interactive
8884 * at all (or, bizarrely but legally, accepts the
8885 * user without actually issuing any prompts).
8886 * Give up on it entirely. */
8888 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8889 s->kbd_inter_refused = TRUE; /* don't try it again */
8894 * Loop while the server continues to send INFO_REQUESTs.
8896 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
8898 char *name, *inst, *lang;
8899 int name_len, inst_len, lang_len;
8903 * We've got a fresh USERAUTH_INFO_REQUEST.
8904 * Get the preamble and start building a prompt.
8906 ssh_pkt_getstring(pktin, &name, &name_len);
8907 ssh_pkt_getstring(pktin, &inst, &inst_len);
8908 ssh_pkt_getstring(pktin, &lang, &lang_len);
8909 s->cur_prompt = new_prompts(ssh->frontend);
8910 s->cur_prompt->to_server = TRUE;
8913 * Get any prompt(s) from the packet.
8915 s->num_prompts = ssh_pkt_getuint32(pktin);
8916 for (i = 0; i < s->num_prompts; i++) {
8920 static char noprompt[] =
8921 "<server failed to send prompt>: ";
8923 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8924 echo = ssh2_pkt_getbool(pktin);
8927 prompt_len = lenof(noprompt)-1;
8929 add_prompt(s->cur_prompt,
8930 dupprintf("%.*s", prompt_len, prompt),
8935 /* FIXME: better prefix to distinguish from
8937 s->cur_prompt->name =
8938 dupprintf("SSH server: %.*s", name_len, name);
8939 s->cur_prompt->name_reqd = TRUE;
8941 s->cur_prompt->name =
8942 dupstr("SSH server authentication");
8943 s->cur_prompt->name_reqd = FALSE;
8945 /* We add a prefix to try to make it clear that a prompt
8946 * has come from the server.
8947 * FIXME: ugly to print "Using..." in prompt _every_
8948 * time round. Can this be done more subtly? */
8949 /* Special case: for reasons best known to themselves,
8950 * some servers send k-i requests with no prompts and
8951 * nothing to display. Keep quiet in this case. */
8952 if (s->num_prompts || name_len || inst_len) {
8953 s->cur_prompt->instruction =
8954 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8955 inst_len ? "\n" : "", inst_len, inst);
8956 s->cur_prompt->instr_reqd = TRUE;
8958 s->cur_prompt->instr_reqd = FALSE;
8962 * Display any instructions, and get the user's
8966 int ret; /* not live over crReturn */
8967 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8970 crWaitUntilV(!pktin);
8971 ret = get_userpass_input(s->cur_prompt, in, inlen);
8976 * Failed to get responses. Terminate.
8978 free_prompts(s->cur_prompt);
8979 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8980 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8987 * Send the response(s) to the server.
8989 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
8990 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8991 for (i=0; i < s->num_prompts; i++) {
8992 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8993 ssh2_pkt_addstring(s->pktout,
8994 s->cur_prompt->prompts[i]->result);
8995 end_log_omission(ssh, s->pktout);
8997 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9000 * Free the prompts structure from this iteration.
9001 * If there's another, a new one will be allocated
9002 * when we return to the top of this while loop.
9004 free_prompts(s->cur_prompt);
9007 * Get the next packet in case it's another
9010 crWaitUntilV(pktin);
9015 * We should have SUCCESS or FAILURE now.
9019 } else if (s->can_passwd) {
9022 * Plain old password authentication.
9024 int ret; /* not live over crReturn */
9025 int changereq_first_time; /* not live over crReturn */
9027 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9029 s->cur_prompt = new_prompts(ssh->frontend);
9030 s->cur_prompt->to_server = TRUE;
9031 s->cur_prompt->name = dupstr("SSH password");
9032 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9037 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9040 crWaitUntilV(!pktin);
9041 ret = get_userpass_input(s->cur_prompt, in, inlen);
9046 * Failed to get responses. Terminate.
9048 free_prompts(s->cur_prompt);
9049 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9050 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9055 * Squirrel away the password. (We may need it later if
9056 * asked to change it.)
9058 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9059 free_prompts(s->cur_prompt);
9062 * Send the password packet.
9064 * We pad out the password packet to 256 bytes to make
9065 * it harder for an attacker to find the length of the
9068 * Anyone using a password longer than 256 bytes
9069 * probably doesn't have much to worry about from
9070 * people who find out how long their password is!
9072 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9073 ssh2_pkt_addstring(s->pktout, ssh->username);
9074 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9075 /* service requested */
9076 ssh2_pkt_addstring(s->pktout, "password");
9077 ssh2_pkt_addbool(s->pktout, FALSE);
9078 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
9079 ssh2_pkt_addstring(s->pktout, s->password);
9080 end_log_omission(ssh, s->pktout);
9081 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9082 logevent("Sent password");
9083 s->type = AUTH_TYPE_PASSWORD;
9086 * Wait for next packet, in case it's a password change
9089 crWaitUntilV(pktin);
9090 changereq_first_time = TRUE;
9092 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9095 * We're being asked for a new password
9096 * (perhaps not for the first time).
9097 * Loop until the server accepts it.
9100 int got_new = FALSE; /* not live over crReturn */
9101 char *prompt; /* not live over crReturn */
9102 int prompt_len; /* not live over crReturn */
9106 if (changereq_first_time)
9107 msg = "Server requested password change";
9109 msg = "Server rejected new password";
9111 c_write_str(ssh, msg);
9112 c_write_str(ssh, "\r\n");
9115 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9117 s->cur_prompt = new_prompts(ssh->frontend);
9118 s->cur_prompt->to_server = TRUE;
9119 s->cur_prompt->name = dupstr("New SSH password");
9120 s->cur_prompt->instruction =
9121 dupprintf("%.*s", prompt_len, prompt);
9122 s->cur_prompt->instr_reqd = TRUE;
9124 * There's no explicit requirement in the protocol
9125 * for the "old" passwords in the original and
9126 * password-change messages to be the same, and
9127 * apparently some Cisco kit supports password change
9128 * by the user entering a blank password originally
9129 * and the real password subsequently, so,
9130 * reluctantly, we prompt for the old password again.
9132 * (On the other hand, some servers don't even bother
9133 * to check this field.)
9135 add_prompt(s->cur_prompt,
9136 dupstr("Current password (blank for previously entered password): "),
9138 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9140 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9144 * Loop until the user manages to enter the same
9149 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9152 crWaitUntilV(!pktin);
9153 ret = get_userpass_input(s->cur_prompt, in, inlen);
9158 * Failed to get responses. Terminate.
9160 /* burn the evidence */
9161 free_prompts(s->cur_prompt);
9162 smemclr(s->password, strlen(s->password));
9164 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9165 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9171 * If the user specified a new original password
9172 * (IYSWIM), overwrite any previously specified
9174 * (A side effect is that the user doesn't have to
9175 * re-enter it if they louse up the new password.)
9177 if (s->cur_prompt->prompts[0]->result[0]) {
9178 smemclr(s->password, strlen(s->password));
9179 /* burn the evidence */
9182 dupstr(s->cur_prompt->prompts[0]->result);
9186 * Check the two new passwords match.
9188 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9189 s->cur_prompt->prompts[2]->result)
9192 /* They don't. Silly user. */
9193 c_write_str(ssh, "Passwords do not match\r\n");
9198 * Send the new password (along with the old one).
9199 * (see above for padding rationale)
9201 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9202 ssh2_pkt_addstring(s->pktout, ssh->username);
9203 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9204 /* service requested */
9205 ssh2_pkt_addstring(s->pktout, "password");
9206 ssh2_pkt_addbool(s->pktout, TRUE);
9207 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
9208 ssh2_pkt_addstring(s->pktout, s->password);
9209 ssh2_pkt_addstring(s->pktout,
9210 s->cur_prompt->prompts[1]->result);
9211 free_prompts(s->cur_prompt);
9212 end_log_omission(ssh, s->pktout);
9213 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9214 logevent("Sent new password");
9217 * Now see what the server has to say about it.
9218 * (If it's CHANGEREQ again, it's not happy with the
9221 crWaitUntilV(pktin);
9222 changereq_first_time = FALSE;
9227 * We need to reexamine the current pktin at the top
9228 * of the loop. Either:
9229 * - we weren't asked to change password at all, in
9230 * which case it's a SUCCESS or FAILURE with the
9232 * - we sent a new password, and the server was
9233 * either OK with it (SUCCESS or FAILURE w/partial
9234 * success) or unhappy with the _old_ password
9235 * (FAILURE w/o partial success)
9236 * In any of these cases, we go back to the top of
9237 * the loop and start again.
9242 * We don't need the old password any more, in any
9243 * case. Burn the evidence.
9245 smemclr(s->password, strlen(s->password));
9249 char *str = dupprintf("No supported authentication methods available"
9250 " (server sent: %.*s)",
9253 ssh_disconnect(ssh, str,
9254 "No supported authentication methods available",
9255 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9265 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9267 /* Clear up various bits and pieces from authentication. */
9268 if (s->publickey_blob) {
9269 sfree(s->publickey_blob);
9270 sfree(s->publickey_comment);
9272 if (s->agent_response)
9273 sfree(s->agent_response);
9275 if (s->userauth_success) {
9277 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9278 * packets since. Signal the transport layer to consider enacting
9279 * delayed compression.
9281 * (Relying on we_are_in is not sufficient, as
9282 * draft-miller-secsh-compression-delayed is quite clear that it
9283 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9284 * become set for other reasons.)
9286 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9290 * Now the connection protocol has started, one way or another.
9293 ssh->channels = newtree234(ssh_channelcmp);
9296 * Set up handlers for some connection protocol messages, so we
9297 * don't have to handle them repeatedly in this coroutine.
9299 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9300 ssh2_msg_channel_window_adjust;
9301 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9302 ssh2_msg_global_request;
9305 * Create the main session channel.
9307 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9308 ssh->mainchan = NULL;
9310 ssh->mainchan = snew(struct ssh_channel);
9311 ssh->mainchan->ssh = ssh;
9312 ssh2_channel_init(ssh->mainchan);
9314 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9316 * Just start a direct-tcpip channel and use it as the main
9319 ssh_send_port_open(ssh->mainchan,
9320 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9321 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9325 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9326 logevent("Opening session as main channel");
9327 ssh2_pkt_send(ssh, s->pktout);
9328 ssh->ncmode = FALSE;
9330 crWaitUntilV(pktin);
9331 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9332 bombout(("Server refused to open channel"));
9334 /* FIXME: error data comes back in FAILURE packet */
9336 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9337 bombout(("Server's channel confirmation cited wrong channel"));
9340 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9341 ssh->mainchan->halfopen = FALSE;
9342 ssh->mainchan->type = CHAN_MAINSESSION;
9343 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9344 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9345 add234(ssh->channels, ssh->mainchan);
9346 update_specials_menu(ssh->frontend);
9347 logevent("Opened main channel");
9351 * Now we have a channel, make dispatch table entries for
9352 * general channel-based messages.
9354 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9355 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9356 ssh2_msg_channel_data;
9357 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9358 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9359 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9360 ssh2_msg_channel_open_confirmation;
9361 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9362 ssh2_msg_channel_open_failure;
9363 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9364 ssh2_msg_channel_request;
9365 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9366 ssh2_msg_channel_open;
9367 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9368 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9371 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
9373 * This message indicates to the server that we promise
9374 * not to try to run any other channel in parallel with
9375 * this one, so it's safe for it to advertise a very large
9376 * window and leave the flow control to TCP.
9378 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9379 "simple@putty.projects.tartarus.org",
9381 ssh2_pkt_send(ssh, s->pktout);
9385 * Enable port forwardings.
9387 ssh_setup_portfwd(ssh, ssh->conf);
9389 if (ssh->mainchan && !ssh->ncmode) {
9391 * Send the CHANNEL_REQUESTS for the main session channel.
9392 * Each one is handled by its own little asynchronous
9396 /* Potentially enable X11 forwarding. */
9397 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
9399 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9400 conf_get_int(ssh->conf, CONF_x11_auth),
9402 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
9404 /* Potentially enable agent forwarding. */
9405 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists())
9406 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
9408 /* Now allocate a pty for the session. */
9409 if (!conf_get_int(ssh->conf, CONF_nopty))
9410 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
9412 /* Send environment variables. */
9413 ssh2_setup_env(ssh->mainchan, NULL, NULL);
9416 * Start a shell or a remote command. We may have to attempt
9417 * this twice if the config data has provided a second choice
9424 if (ssh->fallback_cmd) {
9425 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9426 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
9428 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9429 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
9433 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
9434 ssh2_response_authconn, NULL);
9435 ssh2_pkt_addstring(s->pktout, cmd);
9437 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
9438 ssh2_response_authconn, NULL);
9439 ssh2_pkt_addstring(s->pktout, cmd);
9441 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
9442 ssh2_response_authconn, NULL);
9444 ssh2_pkt_send(ssh, s->pktout);
9446 crWaitUntilV(pktin);
9448 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9449 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9450 bombout(("Unexpected response to shell/command request:"
9451 " packet type %d", pktin->type));
9455 * We failed to start the command. If this is the
9456 * fallback command, we really are finished; if it's
9457 * not, and if the fallback command exists, try falling
9458 * back to it before complaining.
9460 if (!ssh->fallback_cmd &&
9461 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
9462 logevent("Primary command failed; attempting fallback");
9463 ssh->fallback_cmd = TRUE;
9466 bombout(("Server refused to start a shell/command"));
9469 logevent("Started a shell/command");
9474 ssh->editing = ssh->echoing = TRUE;
9477 ssh->state = SSH_STATE_SESSION;
9478 if (ssh->size_needed)
9479 ssh_size(ssh, ssh->term_width, ssh->term_height);
9480 if (ssh->eof_needed)
9481 ssh_special(ssh, TS_EOF);
9487 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
9492 s->try_send = FALSE;
9496 * _All_ the connection-layer packets we expect to
9497 * receive are now handled by the dispatch table.
9498 * Anything that reaches here must be bogus.
9501 bombout(("Strange packet received: type %d", pktin->type));
9503 } else if (ssh->mainchan) {
9505 * We have spare data. Add it to the channel buffer.
9507 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
9512 struct ssh_channel *c;
9514 * Try to send data on all channels if we can.
9516 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
9517 ssh2_try_send_and_unthrottle(ssh, c);
9525 * Handlers for SSH-2 messages that might arrive at any moment.
9527 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
9529 /* log reason code in disconnect message */
9533 reason = ssh_pkt_getuint32(pktin);
9534 ssh_pkt_getstring(pktin, &msg, &msglen);
9536 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9537 buf = dupprintf("Received disconnect message (%s)",
9538 ssh2_disconnect_reasons[reason]);
9540 buf = dupprintf("Received disconnect message (unknown"
9541 " type %d)", reason);
9545 buf = dupprintf("Disconnection message text: %.*s",
9548 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9550 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9551 ssh2_disconnect_reasons[reason] : "unknown",
9556 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
9558 /* log the debug message */
9562 /* XXX maybe we should actually take notice of the return value */
9563 ssh2_pkt_getbool(pktin);
9564 ssh_pkt_getstring(pktin, &msg, &msglen);
9566 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
9569 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
9571 do_ssh2_transport(ssh, NULL, 0, pktin);
9575 * Called if we receive a packet that isn't allowed by the protocol.
9576 * This only applies to packets whose meaning PuTTY understands.
9577 * Entirely unknown packets are handled below.
9579 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
9581 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
9582 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
9584 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
9588 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
9590 struct Packet *pktout;
9591 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9592 ssh2_pkt_adduint32(pktout, pktin->sequence);
9594 * UNIMPLEMENTED messages MUST appear in the same order as the
9595 * messages they respond to. Hence, never queue them.
9597 ssh2_pkt_send_noqueue(ssh, pktout);
9601 * Handle the top-level SSH-2 protocol.
9603 static void ssh2_protocol_setup(Ssh ssh)
9608 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9610 for (i = 0; i < 256; i++)
9611 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9614 * Initially, we only accept transport messages (and a few generic
9615 * ones). do_ssh2_authconn will add more when it starts.
9616 * Messages that are understood but not currently acceptable go to
9617 * ssh2_msg_unexpected.
9619 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
9620 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
9621 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
9622 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
9623 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
9624 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
9625 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
9626 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9627 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9628 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
9629 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
9630 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
9631 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
9632 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
9633 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
9634 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
9635 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9636 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9637 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
9638 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
9639 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
9640 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
9641 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
9642 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
9643 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
9644 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
9645 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
9646 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
9647 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
9648 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
9649 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
9650 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
9651 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
9654 * These messages have a special handler from the start.
9656 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
9657 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
9658 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9661 static void ssh2_timer(void *ctx, unsigned long now)
9665 if (ssh->state == SSH_STATE_CLOSED)
9668 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9669 now == ssh->next_rekey) {
9670 do_ssh2_transport(ssh, "timeout", -1, NULL);
9674 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
9675 struct Packet *pktin)
9677 unsigned char *in = (unsigned char *)vin;
9678 if (ssh->state == SSH_STATE_CLOSED)
9682 ssh->incoming_data_size += pktin->encrypted_len;
9683 if (!ssh->kex_in_progress &&
9684 ssh->max_data_size != 0 &&
9685 ssh->incoming_data_size > ssh->max_data_size)
9686 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9690 ssh->packet_dispatch[pktin->type](ssh, pktin);
9691 else if (!ssh->protocol_initial_phase_done)
9692 do_ssh2_transport(ssh, in, inlen, pktin);
9694 do_ssh2_authconn(ssh, in, inlen, pktin);
9697 static void ssh_cache_conf_values(Ssh ssh)
9699 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9703 * Called to set up the connection.
9705 * Returns an error message, or NULL on success.
9707 static const char *ssh_init(void *frontend_handle, void **backend_handle,
9708 Conf *conf, char *host, int port, char **realhost,
9709 int nodelay, int keepalive)
9714 ssh = snew(struct ssh_tag);
9715 ssh->conf = conf_copy(conf);
9716 ssh_cache_conf_values(ssh);
9717 ssh->version = 0; /* when not ready yet */
9720 ssh->v1_cipher_ctx = NULL;
9721 ssh->crcda_ctx = NULL;
9722 ssh->cscipher = NULL;
9723 ssh->cs_cipher_ctx = NULL;
9724 ssh->sccipher = NULL;
9725 ssh->sc_cipher_ctx = NULL;
9727 ssh->cs_mac_ctx = NULL;
9729 ssh->sc_mac_ctx = NULL;
9731 ssh->cs_comp_ctx = NULL;
9733 ssh->sc_comp_ctx = NULL;
9735 ssh->kex_ctx = NULL;
9736 ssh->hostkey = NULL;
9737 ssh->hostkey_str = NULL;
9739 ssh->close_expected = FALSE;
9740 ssh->clean_exit = FALSE;
9741 ssh->state = SSH_STATE_PREPACKET;
9742 ssh->size_needed = FALSE;
9743 ssh->eof_needed = FALSE;
9746 ssh->deferred_send_data = NULL;
9747 ssh->deferred_len = 0;
9748 ssh->deferred_size = 0;
9749 ssh->fallback_cmd = 0;
9750 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9751 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9752 ssh->x11disp = NULL;
9753 ssh->v1_compressing = FALSE;
9754 ssh->v2_outgoing_sequence = 0;
9755 ssh->ssh1_rdpkt_crstate = 0;
9756 ssh->ssh2_rdpkt_crstate = 0;
9757 ssh->ssh_gotdata_crstate = 0;
9758 ssh->do_ssh1_connection_crstate = 0;
9759 ssh->do_ssh_init_state = NULL;
9760 ssh->do_ssh1_login_state = NULL;
9761 ssh->do_ssh2_transport_state = NULL;
9762 ssh->do_ssh2_authconn_state = NULL;
9765 ssh->mainchan = NULL;
9766 ssh->throttled_all = 0;
9767 ssh->v1_stdout_throttling = 0;
9769 ssh->queuelen = ssh->queuesize = 0;
9770 ssh->queueing = FALSE;
9771 ssh->qhead = ssh->qtail = NULL;
9772 ssh->deferred_rekey_reason = NULL;
9773 bufchain_init(&ssh->queued_incoming_data);
9774 ssh->frozen = FALSE;
9775 ssh->username = NULL;
9776 ssh->sent_console_eof = FALSE;
9777 ssh->got_pty = FALSE;
9779 *backend_handle = ssh;
9782 if (crypto_startup() == 0)
9783 return "Microsoft high encryption pack not installed!";
9786 ssh->frontend = frontend_handle;
9787 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9788 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
9790 ssh->channels = NULL;
9791 ssh->rportfwds = NULL;
9792 ssh->portfwds = NULL;
9797 ssh->conn_throttle_count = 0;
9798 ssh->overall_bufsize = 0;
9799 ssh->fallback_cmd = 0;
9801 ssh->protocol = NULL;
9803 ssh->protocol_initial_phase_done = FALSE;
9807 ssh->incoming_data_size = ssh->outgoing_data_size =
9808 ssh->deferred_data_size = 0L;
9809 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9810 CONF_ssh_rekey_data));
9811 ssh->kex_in_progress = FALSE;
9814 ssh->gsslibs = NULL;
9817 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
9826 static void ssh_free(void *handle)
9828 Ssh ssh = (Ssh) handle;
9829 struct ssh_channel *c;
9830 struct ssh_rportfwd *pf;
9832 if (ssh->v1_cipher_ctx)
9833 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9834 if (ssh->cs_cipher_ctx)
9835 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9836 if (ssh->sc_cipher_ctx)
9837 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9838 if (ssh->cs_mac_ctx)
9839 ssh->csmac->free_context(ssh->cs_mac_ctx);
9840 if (ssh->sc_mac_ctx)
9841 ssh->scmac->free_context(ssh->sc_mac_ctx);
9842 if (ssh->cs_comp_ctx) {
9844 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9846 zlib_compress_cleanup(ssh->cs_comp_ctx);
9848 if (ssh->sc_comp_ctx) {
9850 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9852 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9855 dh_cleanup(ssh->kex_ctx);
9856 sfree(ssh->savedhost);
9858 while (ssh->queuelen-- > 0)
9859 ssh_free_packet(ssh->queue[ssh->queuelen]);
9862 while (ssh->qhead) {
9863 struct queued_handler *qh = ssh->qhead;
9864 ssh->qhead = qh->next;
9867 ssh->qhead = ssh->qtail = NULL;
9869 if (ssh->channels) {
9870 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9873 if (c->u.x11.s != NULL)
9874 x11_close(c->u.x11.s);
9877 case CHAN_SOCKDATA_DORMANT:
9878 if (c->u.pfd.s != NULL)
9879 pfd_close(c->u.pfd.s);
9882 if (ssh->version == 2) {
9883 struct outstanding_channel_request *ocr, *nocr;
9884 ocr = c->v.v2.chanreq_head;
9886 ocr->handler(c, NULL, ocr->ctx);
9891 bufchain_clear(&c->v.v2.outbuffer);
9895 freetree234(ssh->channels);
9896 ssh->channels = NULL;
9899 if (ssh->rportfwds) {
9900 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
9902 freetree234(ssh->rportfwds);
9903 ssh->rportfwds = NULL;
9905 sfree(ssh->deferred_send_data);
9907 x11_free_display(ssh->x11disp);
9908 sfree(ssh->do_ssh_init_state);
9909 sfree(ssh->do_ssh1_login_state);
9910 sfree(ssh->do_ssh2_transport_state);
9911 sfree(ssh->do_ssh2_authconn_state);
9914 sfree(ssh->fullhostname);
9915 sfree(ssh->hostkey_str);
9916 if (ssh->crcda_ctx) {
9917 crcda_free_context(ssh->crcda_ctx);
9918 ssh->crcda_ctx = NULL;
9921 ssh_do_close(ssh, TRUE);
9922 expire_timer_context(ssh);
9924 pinger_free(ssh->pinger);
9925 bufchain_clear(&ssh->queued_incoming_data);
9926 sfree(ssh->username);
9927 conf_free(ssh->conf);
9930 ssh_gss_cleanup(ssh->gsslibs);
9938 * Reconfigure the SSH backend.
9940 static void ssh_reconfig(void *handle, Conf *conf)
9942 Ssh ssh = (Ssh) handle;
9943 char *rekeying = NULL, rekey_mandatory = FALSE;
9944 unsigned long old_max_data_size;
9947 pinger_reconfig(ssh->pinger, ssh->conf, conf);
9949 ssh_setup_portfwd(ssh, conf);
9951 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
9952 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
9954 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
9955 unsigned long now = GETTICKCOUNT();
9957 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
9958 rekeying = "timeout shortened";
9960 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9964 old_max_data_size = ssh->max_data_size;
9965 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9966 CONF_ssh_rekey_data));
9967 if (old_max_data_size != ssh->max_data_size &&
9968 ssh->max_data_size != 0) {
9969 if (ssh->outgoing_data_size > ssh->max_data_size ||
9970 ssh->incoming_data_size > ssh->max_data_size)
9971 rekeying = "data limit lowered";
9974 if (conf_get_int(ssh->conf, CONF_compression) !=
9975 conf_get_int(conf, CONF_compression)) {
9976 rekeying = "compression setting changed";
9977 rekey_mandatory = TRUE;
9980 for (i = 0; i < CIPHER_MAX; i++)
9981 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
9982 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
9983 rekeying = "cipher settings changed";
9984 rekey_mandatory = TRUE;
9986 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
9987 conf_get_int(conf, CONF_ssh2_des_cbc)) {
9988 rekeying = "cipher settings changed";
9989 rekey_mandatory = TRUE;
9992 conf_free(ssh->conf);
9993 ssh->conf = conf_copy(conf);
9994 ssh_cache_conf_values(ssh);
9997 if (!ssh->kex_in_progress) {
9998 do_ssh2_transport(ssh, rekeying, -1, NULL);
9999 } else if (rekey_mandatory) {
10000 ssh->deferred_rekey_reason = rekeying;
10006 * Called to send data down the SSH connection.
10008 static int ssh_send(void *handle, char *buf, int len)
10010 Ssh ssh = (Ssh) handle;
10012 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10015 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10017 return ssh_sendbuffer(ssh);
10021 * Called to query the current amount of buffered stdin data.
10023 static int ssh_sendbuffer(void *handle)
10025 Ssh ssh = (Ssh) handle;
10026 int override_value;
10028 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10032 * If the SSH socket itself has backed up, add the total backup
10033 * size on that to any individual buffer on the stdin channel.
10035 override_value = 0;
10036 if (ssh->throttled_all)
10037 override_value = ssh->overall_bufsize;
10039 if (ssh->version == 1) {
10040 return override_value;
10041 } else if (ssh->version == 2) {
10042 if (!ssh->mainchan)
10043 return override_value;
10045 return (override_value +
10046 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10053 * Called to set the size of the window from SSH's POV.
10055 static void ssh_size(void *handle, int width, int height)
10057 Ssh ssh = (Ssh) handle;
10058 struct Packet *pktout;
10060 ssh->term_width = width;
10061 ssh->term_height = height;
10063 switch (ssh->state) {
10064 case SSH_STATE_BEFORE_SIZE:
10065 case SSH_STATE_PREPACKET:
10066 case SSH_STATE_CLOSED:
10067 break; /* do nothing */
10068 case SSH_STATE_INTERMED:
10069 ssh->size_needed = TRUE; /* buffer for later */
10071 case SSH_STATE_SESSION:
10072 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10073 if (ssh->version == 1) {
10074 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10075 PKT_INT, ssh->term_height,
10076 PKT_INT, ssh->term_width,
10077 PKT_INT, 0, PKT_INT, 0, PKT_END);
10078 } else if (ssh->mainchan) {
10079 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10081 ssh2_pkt_adduint32(pktout, ssh->term_width);
10082 ssh2_pkt_adduint32(pktout, ssh->term_height);
10083 ssh2_pkt_adduint32(pktout, 0);
10084 ssh2_pkt_adduint32(pktout, 0);
10085 ssh2_pkt_send(ssh, pktout);
10093 * Return a list of the special codes that make sense in this
10096 static const struct telnet_special *ssh_get_specials(void *handle)
10098 static const struct telnet_special ssh1_ignore_special[] = {
10099 {"IGNORE message", TS_NOP}
10101 static const struct telnet_special ssh2_ignore_special[] = {
10102 {"IGNORE message", TS_NOP},
10104 static const struct telnet_special ssh2_rekey_special[] = {
10105 {"Repeat key exchange", TS_REKEY},
10107 static const struct telnet_special ssh2_session_specials[] = {
10110 /* These are the signal names defined by RFC 4254.
10111 * They include all the ISO C signals, but are a subset of the POSIX
10112 * required signals. */
10113 {"SIGINT (Interrupt)", TS_SIGINT},
10114 {"SIGTERM (Terminate)", TS_SIGTERM},
10115 {"SIGKILL (Kill)", TS_SIGKILL},
10116 {"SIGQUIT (Quit)", TS_SIGQUIT},
10117 {"SIGHUP (Hangup)", TS_SIGHUP},
10118 {"More signals", TS_SUBMENU},
10119 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10120 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10121 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10122 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10123 {NULL, TS_EXITMENU}
10125 static const struct telnet_special specials_end[] = {
10126 {NULL, TS_EXITMENU}
10128 /* XXX review this length for any changes: */
10129 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10130 lenof(ssh2_rekey_special) +
10131 lenof(ssh2_session_specials) +
10132 lenof(specials_end)];
10133 Ssh ssh = (Ssh) handle;
10135 #define ADD_SPECIALS(name) \
10137 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10138 memcpy(&ssh_specials[i], name, sizeof name); \
10139 i += lenof(name); \
10142 if (ssh->version == 1) {
10143 /* Don't bother offering IGNORE if we've decided the remote
10144 * won't cope with it, since we wouldn't bother sending it if
10146 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10147 ADD_SPECIALS(ssh1_ignore_special);
10148 } else if (ssh->version == 2) {
10149 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10150 ADD_SPECIALS(ssh2_ignore_special);
10151 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
10152 ADD_SPECIALS(ssh2_rekey_special);
10154 ADD_SPECIALS(ssh2_session_specials);
10155 } /* else we're not ready yet */
10158 ADD_SPECIALS(specials_end);
10159 return ssh_specials;
10163 #undef ADD_SPECIALS
10167 * Send special codes. TS_EOF is useful for `plink', so you
10168 * can send an EOF and collect resulting output (e.g. `plink
10171 static void ssh_special(void *handle, Telnet_Special code)
10173 Ssh ssh = (Ssh) handle;
10174 struct Packet *pktout;
10176 if (code == TS_EOF) {
10177 if (ssh->state != SSH_STATE_SESSION) {
10179 * Buffer the EOF in case we are pre-SESSION, so we can
10180 * send it as soon as we reach SESSION.
10182 if (code == TS_EOF)
10183 ssh->eof_needed = TRUE;
10186 if (ssh->version == 1) {
10187 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10188 } else if (ssh->mainchan) {
10189 sshfwd_write_eof(ssh->mainchan);
10190 ssh->send_ok = 0; /* now stop trying to read from stdin */
10192 logevent("Sent EOF message");
10193 } else if (code == TS_PING || code == TS_NOP) {
10194 if (ssh->state == SSH_STATE_CLOSED
10195 || ssh->state == SSH_STATE_PREPACKET) return;
10196 if (ssh->version == 1) {
10197 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10198 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10200 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10201 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10202 ssh2_pkt_addstring_start(pktout);
10203 ssh2_pkt_send_noqueue(ssh, pktout);
10206 } else if (code == TS_REKEY) {
10207 if (!ssh->kex_in_progress && ssh->version == 2) {
10208 do_ssh2_transport(ssh, "at user request", -1, NULL);
10210 } else if (code == TS_BRK) {
10211 if (ssh->state == SSH_STATE_CLOSED
10212 || ssh->state == SSH_STATE_PREPACKET) return;
10213 if (ssh->version == 1) {
10214 logevent("Unable to send BREAK signal in SSH-1");
10215 } else if (ssh->mainchan) {
10216 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10217 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10218 ssh2_pkt_send(ssh, pktout);
10221 /* Is is a POSIX signal? */
10222 char *signame = NULL;
10223 if (code == TS_SIGABRT) signame = "ABRT";
10224 if (code == TS_SIGALRM) signame = "ALRM";
10225 if (code == TS_SIGFPE) signame = "FPE";
10226 if (code == TS_SIGHUP) signame = "HUP";
10227 if (code == TS_SIGILL) signame = "ILL";
10228 if (code == TS_SIGINT) signame = "INT";
10229 if (code == TS_SIGKILL) signame = "KILL";
10230 if (code == TS_SIGPIPE) signame = "PIPE";
10231 if (code == TS_SIGQUIT) signame = "QUIT";
10232 if (code == TS_SIGSEGV) signame = "SEGV";
10233 if (code == TS_SIGTERM) signame = "TERM";
10234 if (code == TS_SIGUSR1) signame = "USR1";
10235 if (code == TS_SIGUSR2) signame = "USR2";
10236 /* The SSH-2 protocol does in principle support arbitrary named
10237 * signals, including signame@domain, but we don't support those. */
10239 /* It's a signal. */
10240 if (ssh->version == 2 && ssh->mainchan) {
10241 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10242 ssh2_pkt_addstring(pktout, signame);
10243 ssh2_pkt_send(ssh, pktout);
10244 logeventf(ssh, "Sent signal SIG%s", signame);
10247 /* Never heard of it. Do nothing */
10252 void *new_sock_channel(void *handle, Socket s)
10254 Ssh ssh = (Ssh) handle;
10255 struct ssh_channel *c;
10256 c = snew(struct ssh_channel);
10259 ssh2_channel_init(c);
10260 c->halfopen = TRUE;
10261 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10263 add234(ssh->channels, c);
10268 * This is called when stdout/stderr (the entity to which
10269 * from_backend sends data) manages to clear some backlog.
10271 static void ssh_unthrottle(void *handle, int bufsize)
10273 Ssh ssh = (Ssh) handle;
10276 if (ssh->version == 1) {
10277 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10278 ssh->v1_stdout_throttling = 0;
10279 ssh_throttle_conn(ssh, -1);
10282 if (ssh->mainchan) {
10283 ssh2_set_window(ssh->mainchan,
10284 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10285 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10286 if (conf_get_int(ssh->conf, CONF_ssh_simple))
10289 buflimit = ssh->mainchan->v.v2.locmaxwin;
10290 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10291 ssh->mainchan->throttling_conn = 0;
10292 ssh_throttle_conn(ssh, -1);
10298 * Now process any SSH connection data that was stashed in our
10299 * queue while we were frozen.
10301 ssh_process_queued_incoming_data(ssh);
10304 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
10306 struct ssh_channel *c = (struct ssh_channel *)channel;
10308 struct Packet *pktout;
10310 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
10312 if (ssh->version == 1) {
10313 send_packet(ssh, SSH1_MSG_PORT_OPEN,
10314 PKT_INT, c->localid,
10317 /* PKT_STR, <org:orgport>, */
10320 pktout = ssh2_chanopen_init(c, "direct-tcpip");
10321 ssh2_pkt_addstring(pktout, hostname);
10322 ssh2_pkt_adduint32(pktout, port);
10324 * We make up values for the originator data; partly it's
10325 * too much hassle to keep track, and partly I'm not
10326 * convinced the server should be told details like that
10327 * about my local network configuration.
10328 * The "originator IP address" is syntactically a numeric
10329 * IP address, and some servers (e.g., Tectia) get upset
10330 * if it doesn't match this syntax.
10332 ssh2_pkt_addstring(pktout, "0.0.0.0");
10333 ssh2_pkt_adduint32(pktout, 0);
10334 ssh2_pkt_send(ssh, pktout);
10338 static int ssh_connected(void *handle)
10340 Ssh ssh = (Ssh) handle;
10341 return ssh->s != NULL;
10344 static int ssh_sendok(void *handle)
10346 Ssh ssh = (Ssh) handle;
10347 return ssh->send_ok;
10350 static int ssh_ldisc(void *handle, int option)
10352 Ssh ssh = (Ssh) handle;
10353 if (option == LD_ECHO)
10354 return ssh->echoing;
10355 if (option == LD_EDIT)
10356 return ssh->editing;
10360 static void ssh_provide_ldisc(void *handle, void *ldisc)
10362 Ssh ssh = (Ssh) handle;
10363 ssh->ldisc = ldisc;
10366 static void ssh_provide_logctx(void *handle, void *logctx)
10368 Ssh ssh = (Ssh) handle;
10369 ssh->logctx = logctx;
10372 static int ssh_return_exitcode(void *handle)
10374 Ssh ssh = (Ssh) handle;
10375 if (ssh->s != NULL)
10378 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
10382 * cfg_info for SSH is the currently running version of the
10383 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10385 static int ssh_cfg_info(void *handle)
10387 Ssh ssh = (Ssh) handle;
10388 return ssh->version;
10392 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10393 * that fails. This variable is the means by which scp.c can reach
10394 * into the SSH code and find out which one it got.
10396 extern int ssh_fallback_cmd(void *handle)
10398 Ssh ssh = (Ssh) handle;
10399 return ssh->fallback_cmd;
10402 Backend ssh_backend = {
10412 ssh_return_exitcode,
10416 ssh_provide_logctx,